UTSA Runner Research Press (Univ. of Texas at San Antonio)
Not a member yet
6846 research outputs found
Sort by
Spraying Conflict: Aerial Drug Eradication and Armed Violence in Colombia
Full text linkHow do state interventions targeting illicit economies influence armed violence? Using Colombia as a critical case, we argue that aerial spraying of coca crops exacerbates violence by destabilizing local power dynamics and disrupting interactions among armed actors, civilians, and the state. Using municipal-level data from 2000 to 2015, we find that aerial spraying increases overall levels of violence in affected areas. Aerial spraying, we find, propitiates retaliatory violence against the state, stimulates turf wars between armed organizations, and produces civilian victimization. Moreover, we show that paramilitaries and criminal organizations respond more sharply to aerial spraying, escalating retaliation against the state and violence against civilians. By contrast, insurgent violence remains more consistent, driven by ideological goals and largely independent of eradication efforts. These findings reveal how fleeting large-scale interventions can inadvertently fuel conflict by altering the strategic equilibria of violent actors in illicit economies.Political Science and Geograph
ESTABLISHMENT OF A COMPUTATIONAL FRAMEWORK FOR ANGIOGENESIS UNDER VARYING SCAFFOLD-HYDROGEL CONDITIONS
No full textThe full text of this item is not available at this time because the author has placed this item under an embargo until December 11, 2030.The success of regenerative medicine strategies for critical-sized bone defects depends on the rapid vascularization of biomaterial scaffolds. While biochemical cues are well researched, the role of the mechanical microenvironment remains less understood. The goal of this thesis is to investigate the inherent kinetics of vessel growth and the properties of a biomaterial scaffold-hydrogel combination that further direct it. A finite element model was developed to stimulate angiogenesis within hydroxyapatite scaffolds to systematically vary the growth segment velocity parameter to determine its influence on blood vessel maturation. Additionally, rigid constraints to the hydrogel at pore walls were applied to compare the fixed-boundary conditions against the free-boundary conditions, which allow unconstrained deformation. Results demonstrated that comparison between unconstrained and fixed boundary conditions showed no significant relative difference in vascular network evolution over time, indicating that geometric confinement dominates over the specific mechanical compliance of the pore walls. Furthermore, analysis of growth segment velocity revealed that increased velocity consistently enhanced network formation across all boundary conditions, with an observable optimum. These findings provide an understanding of the mechanical rules governing vascularization, enabling a refined predictive design of scaffolds optimized for rapid blood vessel growth using a computational model.Biomedical Engineerin
Design of Earth Abundant Transition Metal Complexes for Hydrofunctionlization Catalysis
Full text linkThe design of ligand systems for catalysis has traditionally been influenced by the desire to control the steric and/or electronic environment about the metal center. The idea of incorporating secondary functionalities such as sites of Lewis acidity has also shaped the creation of new ligand architectures. The work discussed herein describes studies on two types of ligand systems for hydrofunctionalization catalysis with first row transition metals. A pyrrole-based pincer ligand, CyPNP (PNP = anion of 2,5-bis(dicyclohexylphosphinomethyl)pyrrole), and two new classes of pyridine-containing NNN ligands incorporating benzotellurazole and isochalcogenazole units are described. Chapter 2 explores hydrosilyl complexes with CyPNP, such compounds were found to catalyzed aldehyde and ketone hydrosilylation through a mechanism consistent with coordination of the carbonyl functionality to Co(I). Chapter 3 describes the synthesis and catalytic application of CyPNP cobalt complexes in alkyne hydroboration. Chapter 4 describes additional catalytic hydroelementation reactions of unsaturated CC bonds using Group 14 elements. CyPNPCo-PMe3 showed successful hydrosilylation of alkynes. Hydrostannylation and hydrostannane complexes were synthesized and performed readily at mild conditions. Chapter 5 describes the synthesis of a set of new benzotellurazole containing NNN ligands and their preliminary coordination chemistry with several 3d metals. Due to challenges with weak binding and insolubility, further studies of these complexes were limited. Chapter 6 explores the synthesis of alternative NNN ligands incorporating selenium and tellurium isochalcogenazoles. The structure, spectroscopy, and reactivity of the compounds with transition metals are presented as a strategy to introduce soft Lewis-acid functionalities into catalyst designs to alter selectivity in hydrofunctionalization catalysis .Chemistr
Holistic Benefit–Cost Analysis of Bridge Seismic Retrofitting Coupled with Artificial Intelligence-Based Decision Policy
Full text linkHighway bridges are fundamental components of transportation networks. Although chronic deterioration of bridge conditions has been the primary focus of bridge asset management, the implications of seismic hazards, as well as their interaction with bridge maintenance and seismic retrofitting strategies has yet to be fully studied. This study aims to quantitatively assess the long-term performance and cost effectiveness of various seismic retrofitting options when coupled with artificial intelligence (AI)–based maintenance decision policies. To achieve this, bridge component deterioration is modeled using Markov processes. To account for seismic hazard threats, bridge system-level seismic fragility and risk quantification modules are introduced to estimate seismic damage probabilities. The analysis also includes a comprehensive evaluation of both direct and indirect costs associated with maintenance and retrofitting actions for life-cycle cost estimations. Next, the developed bridge performance and life-cycle cost models are coupled with a powerful AI approach known as deep reinforcement learning (DRL) to provide a comprehensive bridge management policy. Finally, the study presents an AI-based maintenance policy integrated with seismic retrofitting strategies and compared with condition-based maintenance policy. The findings underscore the benefits of a holistic AI-driven decision-making process that can manage both routine maintenance and seismic repair actions. Moreover, the evaluation of seismic retrofitting within an AI-driven maintenance framework highlights the long-term benefits of such integration, especially for high seismicity regions.Civil and Environmental Engineering, and Construction Managemen
Generative Artificial Intelligence as an Educational Collaborator: A Next-Generation Resource
Full text linkInterdisciplinary Learning and Teachin
Carbonate Stability Under Stress: Environmental Forcing on the Southeastern Arabian Platform During OAE1a
Full text linkThe Early Cretaceous Oceanic Anoxic Event 1a (OAE1a) was a major paleoceanographic crisis driven by volcanic activity associated with the Ontong Java Plateau in the Pacific. This event led to elevated atmospheric pCO₂, disruptions in the global carbon cycle, ocean acidification, and widespread ecological stress. The thick carbonate successions of the Kahmah Group in Oman, part of the Arabian Platform, provide a well-exposed and continuous record of OAE1a, offering critical insights into how equatorial shallow marine carbonate platforms responded to this global perturbation. This study examines the resilience of Oman’s carbonate ecosystems during OAE1a, with the central hypothesis that the region’s arid climate and low nutrient influx enabled sustained carbonate production despite widespread environmental stress. Our focus is a ~220 m-thick stratigraphic section at Wadi Muaydin, where previous research suggests a partial record of OAE1a is preserved. Methodologies include petrographic microfacies analysis following Dunham’s classification, stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotope geochemistry to assess diagenetic alteration and support chemostratigraphic correlation with global reference sections, and X-ray fluorescence (XRF) analysis to evaluate geochemical proxies related to paleo-productivity. Preliminary interpretations suggest that limited terrigenous input and minimal nutrient enrichment during OAE1a favored a shift in facies within the Upper Kharaib Formation—from rudist- and coral-dominated assemblages to Lithocodium-Bacinella rich facies, characterized by wackestone to packstone textures. In contrast, the overlying Shu’aiba Formation is marked by a return to miliolid and rudist-rich deposits with grainstone to rudstone facies, with no field evidence for increased detrital influx. These observations suggest ecological adaptation and sustained platform productivity, highlighting the resilience of this carbonate system during a time of global environmental upheaval.Earth and Planetary Science
Ferroptosis and Radiotherapy in Lung Cancer
Full text linkBackground: Lung cancer (LC) is a leading cause of cancer mortality worldwide. While radiotherapy (RT) has been a lasting cornerstone of LC management, there are concerns due to tumor radioresistance and unintended damage to surrounding healthy tissue. Ferroptosis is a recently described mechanism of programmed cell death which has potential to serve as a complementary adjunct to facilitate RT-based LC treatment. Objectives: This review is a comprehensive overview of ferroptosis in the broader context of synergism with RT for LC. Summary: Ferroptosis is essentially driven by intracellular iron overload, which drives the formation of reactive oxygen species, ultimately resulting in membrane instability and cell death. LC lines have been shown to exhibit a heterogeneous mix of pro- and anti-ferroptotic changes. RT shows promise as a potential ferroptosis inducer, especially when complemented with pharmacologic agents such as erastin. Conclusions: Ferroptosis represents a promising modern adjunct to a traditional therapeutic strategy. Future work should focus on rigorous dosage standards to avoid unintended toxicity, repurposing of currently available drugs into ferroptosis inducers, and establishment of safety protocols to begin the pathway towards clinical studies
Del Salon a La Direccion: The Journey of Former Bilingual Students Leading Rural Schools
Full text linkThis qualitative study examines how three rural school and district leaders in Texas's Wintergarden region—each a former bilingual student—translate lived experiences of language learning into leadership that advances equity. Grounded in Anzaldúa's Borderland Theory and using pláticas as both method and analytic lens, the study traces how linguistic navigation, cultural identity, and rural place shape leadership stance and action through two individual conversations and one communal plática per participant. Four cross-case themes emerged. First, navigating linguistic borderlands reveals how early discrimination and translanguaging practices were later repurposed as leadership assets. Second, cultural representation shows that seeing bilingual educators catalyzed identity affirmation and role-modeling. Third, transforming systems illuminates policy and program change as equity work, including dual language programs, inclusive communication, and integrated classroom placement. Fourth, rural rootedness demonstrates how deep community ties created both constraints through limited resources and staffing challenges, and leverage through trust and accountability relationships. Findings show how conocimiento derived from borderland experiences informs concrete practices such as family engagement in two languages, holistic assessment approaches, and technology integration for multimodal evidence of learning. The study contributes evidence that leaders with Emergent Bilingual histories enact distinct equity-oriented logics with implications for asset-based leadership preparation, district program design, and rural systems improvement.Educational Leadership and Policy Studie
Pan-cancer Outcome Prediction using Multi-classifier Systems
Full text linkPredicting the outcome of cancer progression from high-throughput expression profiling data is a daunting task in practice due to tumor heterogeneity and lack of observations compared to high dimensionality. Multi-task learning methods have been applied to leverage the similarity between cancers of different tissue origins and improve the performance of survival analysis models. Nonetheless, the existence of both inter-cancer similarity and intra-cancer heterogeneity renders accurate predictive modeling difficult. In this work, we propose a novel strategy by considering many different cancer types together and leveraging patient similarity within individual cancers and across different cancer types. Experimental results suggest that our proposed multi-classifier approach outperforms baselines and state-of-the-art multi-task learning methods in a pan-cancer setting.Computer Scienc
It Takes a Village: Addressing Community Needs to Implement Firearm Prohibitions for Domestic Violence Protective Order Respondents
Full text linkProhibiting domestic violence protective order (DVPO) respondents from firearms is an effective strategy to prevent intimate partner homicide. However, DVPO gun laws vary considerably across states, and the implementation of such laws is inconsistent across localities. Local context, such as resource availability, priorities, and politics, differs across types of communities and impacts the implementation of laws. We conducted in-depth key informant interviews with victim service and criminal justice professionals (N = 27) working in urban communities, rural communities, and statewide organizations to better understand: (a) what communities need to effectively prohibit DVPO respondents from firearms (i.e., the DVPO gun law) and (b) strategies to help communities view domestic gun violence as a safety issue versus a second amendment issue. We used conventional content analysis to analyze the content of all interviews. Our results revealed a diverse range of community needs for implementing the DVPO gun law; some of which included tangible resources related to personnel, funding, and storage, and other more intangible resources related to community leadership and culture. We also observed competing ideas around strict state leadership directives for how to implement the DVPO gun law versus maintaining community-level autonomy. Finally, many participants stressed the importance of using more effective language to frame the issue of DVPO gun laws as central to addressing domestic violence more broadly, rather than gun control. Regardless of the political landscape and state legislation, communities of all types should be able to make concerted local efforts to limit abusers’ access to firearms, given the danger posed to victims and the broader community. Effective efforts require transdisciplinary collaboration, flexibility, ingenuity, leadership, and funding, thus benefiting from a combined criminal justice and public health approach.Criminology and Criminal Justic