26400 research outputs found
Sort by
Effects of Environmental Stressors on Human Tissue-on-a-Chip Platforms
No full textAs space exploration begins to extend beyond low earth orbit, it has become increasingly critical to understand the interaction of the extreme environment of space flight with human systems. While it is known that space-travel induces a vast array of complications to cardiac, neural, musculoskeletal, and immune systems, the mechanisms by which these complications occur are poorly understood. Current research to study the effects of microgravity and radiation are limited to ground simulations, which rarely account for the multifactorial stressors experienced during spaceflight, or long duration studies aboard the International Space Station. Similarly, traditional two-dimensional (2D) models lack the ability to mimic the complex architectures of human physiological systems, thereby reducing their relevance to risks imposed by space travel. There currently exists no technology for the continual monitoring of human tissue systems exposed to extreme environments such as space travel. This work demonstrates the development of such a platform by integrating state-of-the-art MEA technology within a microfluidic device to create a device capable of continual, long-term electrophysiology (EPHYS) monitoring of human neuronal networks in 3D. Exposure of this device to suborbital flight and ionizing radiation successfully validated its use in extreme environmental conditions, while also providing insight into the components of neuronal function affected by microgravity and ionizing radiation including alterations to EPHYS activity, gene expression, and creatine kinase (CK) activity. This work presents novel advancements in the design and application of microfluidic technologies and monitoring of EPHYS activity, highlighting the benefits of its use in both extreme environments and ground-based studies to further our understanding of neuronal function in improving human health
Border Thinking Through Diverse Modalities: An Ethnographic Case Study Of The Multimodal, Multiliteracy, And Translanguaging Practices Of Latinx Emergent Bilingual Youth
No full textThis three-article dissertation explores how translanguaging, multimodality, and multiliteracies intersect to support the learning, identity formation, and meaning-making practices of Latinx emergent bilingual middle school students in El Paso, Texas, a border city shaped by transfronterizx realities. Guided by the frameworks of Border Thinking (Mignolo, 2000) and Pedagogy of Border Thinking (Cervantes-Soon and Carrillo, 2016), this study foregrounds the cultural, linguistic, and epistemic fluidity that characterizes borderland communities. I approach this work as a bricoleur (Denzin and Lincoln, 1994); the three-article format allowed me to center distinct but interconnected theoretical and methodological orientations, reflecting my commitment to situated, decolonial knowledge production. Using an ethnographic case study approach, this research draws from classroom observations, interviews, artifacts, and student testimonios to examine the interactions between a bilingual teacher and his Latinx transfronterizx students. The first article analyzes the teacher\u27s testimonio, showing how his experiencias de vida as a bilingual, bicultural educator, who himself straddled the border, shaped a translanguaging pedagogy rooted in convivencia and epistemic disobedience. The second article examines how multiliteracies and multimodality intersect with translanguaging and border thinking in the classroom, highlighting how digital tools, bilingual texts, and cultural modes such as music create inclusive learning environments that validate students\u27 hybrid identities. The third article, written in Spanish, centers students\u27 microtestimonios through a dialogic-performative methodology, illustrating how they navigate straddling, heteroglossia, and identity construction as they move between linguistic and cultural worlds. Together, these articles contribute to the fields of bilingual education and critical literacy by emphasizing the importance of culturally sustaining, multimodal, and translingual pedagogies within borderland contexts. This dissertation calls for listening to the voices of teachers and students in the U.S.-Mexico borderlands to design more equitable and humanizing educational policies that reflect the lived realities of transfronterizx communities
Machine Learning and Protein Engineering Approaches to Understanding Kinesin-5 Activity
No full textCancer is a term describing a collection of diseases that result in uncontrolled cell growth. Cancer has manifold etiologies and underlying cancers are rouge biochemical pathways involving many different proteins. In the current work, two approaches are used to enhance knowledge of kinesin-5, a potential cancer target involved in cell division. Kinesin-5 promotes cell division by cross-linking and separating microtubules in dividing cells. The first approach uses machine learning (ML) to identify small molecule inhibitors for kinesin-5. Though decades of research have uncovered classes of small-molecules which inhibit kinesin-5 in vitro and in vivo, no candidates have reached phase III clinical trials. In the current work, crystallographic and assay data available for kinesin-5 inhibitors are leveraged to develop ML models for kinesin-5 IC50 predictions. One of the ML models developed is used to screen the Goldilocks subset of the ZINC20 database. Top performing compounds are filtered through a hierarchical clustering approach and ten compounds are presented and their potential binding poses are analyzed. The second approach involves employing a python-based tool, Salt Bridge Builder, to identify putative salt bridges. The highly negatively-charged microtubule proteins, �-tubulin and β-tubulin interact with the positively-charged kinesin-5 to exert their biological function. Salt Bridge Builder is used to determine uncharged-to-charged mutations on kinesin-5 which form salt bridges. Three such mutations which form stable salt bridges in a molecular dynamics (MD) simulation are presented and their effects on the short-distance and long-distance interactions between kinesin-5 and the microtubule proteins are analyzed
Laser Scan Path Design For Controlled Microstructure In Additive Manufacturing With Integrated Reduced-Order Phase-Field Modeling And Deep Reinforcement Learning
No full textLaser Powder Bed Fusion (L-PBF) is a well-established additive manufacturing technique for fabricating intricate metal components with exceptional precision. A significant challenge in L-PBF is the formation of complex microstructures that influence final material properties. We propose a physics-guided, machine learning-aided approach to optimize scan paths for desired microstructure outcomes, such as equiaxed grains. We employed a phase-field method (PFM) to model the evolution of the crystalline grain structure. To reduce computational costs, we trained a surrogate machine learning model, a 3D U-Net convolutional neural network, using single-track phase-field simulations with varying laser powers to predict crystalline grain orientations based on initial microstructure and thermal history. We investigated three scanning strategies across various hatch spacings within a square domain, achieving a speed-up of three orders of magnitude using the surrogate model. To reduce trial and error in designing laser scan toolpaths, we use deep reinforcement learning (DRL) to generate optimized scan paths for target microstructure. The results of three cases demonstrate the effectiveness of the DRL approach. We integrate the surrogate 3D U-Net model into our DRL environment to accelerate the reinforcement-learning training process. The reward function minimizes both aspect ratio and grain volume of the predicted microstructure from the agent\u27s scan path. This presents the first DRL framework that directly minimizes phase-field predicted grain metrics during scan path design. The reinforcement learning algorithm, benchmarked against conventional zigzag approach for smaller and larger domains, demonstrates machine learning methods\u27 potential to enhance microstructure control and computational efficiency in L-PBF optimization
Las Jefas: Latina Leadership On The US-Mexico Border Region Las Jefa\u27s Fronterizas
No full textThis qualitative study shares the lived experiences of a Latina superintendent leading a large school district along the U.S.-Mexico border, with the aim of highlighting the systemic barriers and enabling factors that shape Latina leadership trajectories in historically underrepresented contexts. Grounded in Latino/a Critical Race Theory (LatCrit) and employing a narrative inquiry through Testimonio methodology, a semi-structured, in-depth interview was conducted and transcribed verbatim. Data were analyzed using Saldana\u27s (2015) two-cycle coding approach - narrative coding followed by pattern coding - to distill rich, counter-storytelling insights into the superintendent\u27s journey. Four interrelated themes emerged overcoming systemic barriers and gender bias, harnessing cultural identity and resilience as leadership strengths, navigating unique socio-political challenges of the border context, and advocacy through policy to advance educational equity. Findings underscore the critical role of familial and mentor support networks, bilingualism, and community engagement in fostering Latina leadership. Practical implications call for structured, affinity-based mentorship programs, culturally sustaining leadership development tailored to border communities, and policy reforms that embed equity-by-design in superintendent selection and support. Future research should pursue comparative, multi-site studies and longitudinal designs to further explore intersectional leadership experiences across diverse border regions
A Sociocognitive Perspective On The Activation Of Productive Epistemic Resources In College Students\u27 Understanding Of Chemical Equilibrium
No full textScience education, particularly in higher education, has a content coverage problem: it has long been described as a mile wide, an inch deep in various consensus documents from the National Academies. In chemistry education, the most common general chemistry curriculum covers topics as chapters based on the popular Sienko and Plane 1960\u27s general chemistry textbook. The limited time available in such fast-paced coverage may limit the instructor\u27s modeling and assessment of key performances in developing a mechanistic understanding of complex chemistry phenomena. In this sociocognitive, qualitative investigation, general chemistry II students\u27 responses to assessment prompts were used to activate cognitive and epistemic resources about chemical equilibrium. Student response data was collected through an individual online activity worksheet as well as in-person think-aloud interviews, in which students were asked to draw, describe, calculate concentrations, reason about perturbations, and select mechanistic steps in a chemical equilibrium. To use the sociocognitive framing, the researcher attended general chemistry II lectures related to equilibrium for three instructors (two traditional curriculum, one transformed curriculum) and took observational field notes on the learning environment as well as the instructor\u27s modeling of the content. Activities eliciting molecular level drawings were less likely to activate productive resources among participants. Additionally, student responses were categorized into five distinct epistemic resources including purely descriptive, graphical descriptive, symbolic descriptive, probabilistic descriptive, and dynamic descriptive. Additionally, students\u27 responses in interviews mirrored the cognitive resources modeled by the instructor as seen in the observation such as common heuristics. This suggests that educators\u27 assumptions about students\u27 prior mathematical preparation does not activate productive resources for students\u27 understanding
Warrior Life Transition Program
No full textThe problem that exists is that the Willliam Beaumont Army Medical Center (WBAMC), Internal Medicine Clinic (IMC) treats issues amongst active duty and veteran personnel in a reactionary manner. 6 domains of need: Mental health, (including, sub-domains of anxiety, depression, PTSD, and stress), occupations, pain, family life/connection (Relationships), sleep and alcohol/ substance abuse. Currently there is no one assessment at the WBAMC IMC that looks to assess all of these areas in a reactive way. This project was to develop a reactive assessment to address these domains of need.https://scholarworks.utep.edu/otcapstones/1003/thumbnail.jp
Neuromotor deficits in children with the 22q11 deletion syndrome
No full textThe 22q11 chromosomal deletion syndrome (22q11DS) is associated with a heterogeneous physical phenotype, neurocognitive deficits, and increased risk of later psychiatric illness. Sporadic clinical reports suggested motor differences, but quantitative studies of movement in children with 22q11DS are rare. If present in a majority of affected schoolage children, characterization of neuromotor deficits may prove to be critical for intervention, neurocognitive test interpretation, and understanding etiology. We administered the Movement Assessment Battery for Children to 72 children ages 4.3 to 16.1, including 49 children confirmed positive for the 22q11 deletion and 23 control siblings. We predicted a higher frequency of global and domain impairment in manual dexterity, eye–hand coordination, and balance among affected children. Ninety-four percent of affected children had marked neuromotor deficits, and group scores differed broadly for both global and subarea measures. Secondary analyses showed no impairment differences between younger and older children with 22q11DS, and longitudinal trajectories for 12 affected children suggested stability of deficits over 3-year intervals. Neuromotor deficits in children with 22q11DS occur early in development, continue throughout the school-age years, should be considered in the interpretation of motor-based achievement and IQ tests, and require targeted and ongoing remediation throughout childhood and adolescence. Further studies examining the specificity of motor impairment to 22q11DS are needed
