113588 research outputs found
Sort by
Opto-Mechanical Design and Stray Light Analysis for Unobscured off-Axis Telescope using BRDF Data of Black Paints
No full textSpace telescopes are an extension of the human eye into distant galaxies that allow forthe observation and imaging of phenomena light years away from Earth. There are many variants of space telescopes; a widely cherished design is the three mirror anastigmat (TMA). The TMA is coveted because of its ability to correct for aberrations over a wide field of view. A variation of a typical TMA is an off-axis system that removes the central obscuration of the telescope’s primary mirror (M1). However, the benefits of an off-axis TMA come at the cost of complex mechanical housing of the optical components and stray light correction. Professor Daewook Kim has optically designed an off-axis TMA. This thesis will give an overview of the optical design of the TMA, give an in-depth description of the mechanical design of the baffles, vanes, and apertures of the telescope, describe the collection process of real scatter data of black paints applied to the housing, and outline the stray light analysis performed on this system. The TMA is an f/14 system with a clear aperture of 3000 mm that is essentially diffraction limited. The system has an approximated FOV of +/-0.27◦ by +/-.08◦ and is designed for a semicircle detector plane. In addition to the three curved mirrors, there is also a fourth, folding mirror at the end of the system before the detector. Baffles, vanes, apertures were designed for stray light control of the TMA system. The design was constrained to be less than 9 m by 5 m, and as compact as possible. Real BRDF data was collected and processed for stray light analysis. Different black paints have varied scattering characteristics. Thus, it is essential to measure and apply real BRDF data of various black paints to the mechanical system to ensure accurate stray light analysis. Stray light analysis was performed with the target of less than 10−5 of light was incident on the detector relative to the in-science field for far out-of-science fields
Aces Screening and Referral Pathways in Pediatric Primary Care in Northern Arizona
No full textPurpose. The purpose of this Quality and Process Improvement project was to enhance the education of pediatric primary care providers in Northern Arizona on the importance of recognizing physical and mental impacts of Adverse Childhood Experiences (ACEs), while emphasizing the value of Positive Childhood Experiences (PCEs) as protective factors. The intervention aimed to promote the importance of integrating Trauma Informed Care (TIC) into clinical practice, offer recommendations for ACEs screening during well child visits, and establish a referral pathway to the Center for Resiliency and Wellbeing (CRW). Background. ACEs are associated with poor physical, mental, and behavioral health outcomes
in children that may persist into adulthood. Toxic stress caused by adversity can cause systemic inflammation, increasing the risk of chronic health conditions. Despite growing recognition of these impacts, many providers remain hesitant to screen for ACEs in routine practice or consider ACEs as contributing factors to medical complaints. Methods. A recorded educational session was provided to pediatric providers at North Country Healthcare. The intervention was intended to reinforce existing knowledge on foundational concepts, while introducing or expanding awareness on related topics. The session provided guidance on referring patients to the CRW program as a supportive resource. Pre- and post- intervention surveys assessed provider knowledge, confidence, and intended practice changes. Referral activity was tracked over a five-day implementation period following the educational training. Results. Pre- and post-survey data reflected a 38.83% increase in provider knowledge, confidence, and intended practice change. All three participating providers reported an intent to implement ACEs screening and make referrals to resources such as the CRW program. Although no referrals were made during the five-day post intervention period, participants expressed interest in utilizing the resource when appropriate clinical applications arise. Conclusions. This project supports the use of brief, structured educational interventions as a strategy to improve provider knowledge, confidence, and readiness to implement TIC strategies into daily practices. While the short implementation period limited a measurable change, the educational intervention successfully established a framework for a referral process that can be sustained with continued education, support, and provider engagement
Navigating the Academic Maze: First-Generation Faculty, Career Trajectories and the Search for Institutional Belonging
No full textThis dissertation explores the career trajectories and professional experiences of first-generation faculty at a public research university. The study addresses the gap in understanding how the first-generation identity shapes the sense of belonging in academia. Using an embedded case study design, the research was conducted at Southwest University, where the institution served as the macro case, colleges as the micro cases, and individual participants as the nano cases. Data was collected from 24 full-time first-generation faculty members across 14 academic disciplines through semi-structured interviews, a review of promotion guidelines, and an analysis of curriculum vitae. A multi-level analysis revealed four overarching themes: (1) Cracking the Code: The Hidden Curriculum and Social Capital Divide, (2) The Academic Balancing Act: Teaching, Service, and Burnout, (3) The Power of the Village: Mentorship, Community, and Institutional Gaps, and (4) Flipping the Script: Pushing Back Against Prestige Culture. The analysis is framed by a conceptual framework that integrates Bourdieu’s concepts of capital and habitus, Rios et al.’s expanded framework of funds of knowledge, and Becher and Trowler’s conceptualization of disciplinary cultures. The implications of this study enhance our understanding of the first-generation identity and its impact on career development. The findings support the demystification of academic norms and the enhancement of institutional support for faculty career trajectories. This study highlights the importance of structured mentorship, transparent career expectations, and interdisciplinary collaboration as key factors contributing to a first-generation faculty member’s sense of belonging in academia
Gaussian Processes for the Design and Optimization of the Cylindrical Implosion Platform
No full textSimulating direct-drive inertial confinement experiments presents significant computational challenges, both due to the complexity of the codes required for such simulations and the substantial computational expense associated with target design studies. Machine learning models, and in particular surrogate models, offer a solution by replacing simulation results with a simplified approximation. In this body of work, we apply surrogate modeling and optimization techniques to design studies of the cylindrical implosion platform, which provides a method for diagnosing hydrodynamic instability growth in the high-energy-density regime. Cylindrical targets allow for direct diagnostic access to the instability while preserving the effects of a convergent geometry. By enabling direct measurements of instability growth to be coupled with empirical data on thermonuclear burn, this platform provides a valuable tool for improving our understanding of the complex interplay between mix and burn. Previous studies relied upon xRAGE, Los Alamos’s Eulerian radiation hydrodynamics code, to model this class of implosions. However, full radiation hydrodynamic simulations entail significant computational challenges, both due to the complexity of the codes required for such simulations and the substantial computational expense associated with target design studies, thus motivating the development of machine learning models. We will investigate how these models generate predictions and their ability to measure and represent uncertainty. We will demonstrate how past work, which focused on the optimization of Gaussian process surrogates trained exclusively on output from 1D xRAGE simulations, revealed that optimal designs selected in this manner exhibited a substantial loss in yield when simulated in 2D. Despite their lower prediction accuracy, 1D simulations are less expensive than their 2D counterparts. To improve the predictive performance of the surrogate while maintaining low costs, we introduce a cost-aware multi-fidelity optimization algorithm which integrates data from 1D and 2D simulations to identify target designs that maximize yield. The design selected by the algorithm is discussed, emphasizing the design choices and implosion physics responsible for the target’s improved performance
The Aging Voice: Choral Singing After the Age of Fifty
No full textSinging has been shown to have a variety of benefits for older singers, including improved posture, higher levels of perceived physical health, improved speaking tone, and greater ease of breathing. Choral singing in particular has social and mental health benefits for older adults. Older adults who participate in choirs are less isolated, are more involved in their communities, and have heightened optimism about life. In addition, choral participation can have a positive impact on mindfulness and mental focus and can reduce depression. The human body undergoes numerous age-related physical changes. For people over fifty, these changes can affect their singing experience and participation in choral ensembles. For this study, I have surveyed sources regarding issues of aging that can negatively impact choral participation, as well as approaches to address these issues. Based on this research, I have provided recommendations for application in choral ensembles, including physical accommodations, research-based vocal pedagogy and repertoire selection considerations to support positive and rewarding choral experiences for older adults
Unraveling the Relationship Between Central, Peripheral and Cerebral Arteries Function in a Mouse Model of Marfan Syndrome: Benefits of Exercise Training on Vascular Function and Blood Flow
No full textMarfan syndrome (MFS) is a connective tissue disorder caused by mutations in the fibrillin-1 gene affecting the musculoskeletal, cardiovascular, and pulmonary systems, with a notable vascular effect leading to aortic aneurysm, dissection, and rupture. In recent decades, better diagnostics and advances in medical and surgical treatments have increased the life expectancy in individuals with MFS, hence, other vascular complications have become more concerning. Aging is the dominant risk factor for clinically significant atherosclerotic lesions affecting most often the carotid arteries and carotid artery tortuosity is highly associated with connective tissue diseases, particularly MFS. There is an increased prevalence of intracranial aneurysms and ischemic stroke in hospitalized patients with MFS when compared with healthy controls. Despite these reports our understanding of cerebrovascular and carotid artery function and structure in MFS is very limited. In addition, the cardiovascular benefits of moderate exercise training have been well documented in the literature. Numerous studies have shown that aerobic exercise can improve cognitive function, decrease neuropsychiatric and neurodegenerative symptoms.
This study sought to explore the impact of mild aerobic exercise on the progression of vascular complications in both male and female MFS mice, utilizing high-resolution in vivo ultrasound imaging for precise analysis. The research focused on assessing the functional properties of multiple key arteries, including the aorta, posterior cerebral, carotid, coronary, pulmonary, and renal arteries, in both male and female MFS mice. The study also aimed to explore the relationship between MFS-associated structural and functional changes in the aortic root and phenotypic alterations in other arteries, with the objective of identifying key predictors that could provide insights into vascular health and the potential impact of exercise on arterial structure and function. At 6 weeks of age, male and female control (Fbn1+/+) and MFS (Fbn1C1041G/+) were divided into three experimental groups: Ctrl, MFS, MFS + exercise. MFS mice were subjected to an exercise regimen of 8m/min, 30min/day, 5days/week. At 7 months of age, in vivo ultrasound imaging was performed to measure aortic root diameters and pulse wave velocity, the carotid artery pulse wave velocity (PWV), wall thickness and distensibility, and the peak systolic velocity (PSV) of the posterior cerebral arteries, coronary, pulmonary, and renal arteries. Our data showed significant increases in aortic root diameter and pulse wave velocity (PWV), carotid wall thickness and arterial stiffness, along with reduced carotid distensibility, in both sexes in MFS mice compared to controls. Peak systolic velocity (PSV) was significantly reduced in the pulmonary and posterior cerebral arteries of MFS mice, with no changes observed in coronary or renal arteries. Mild exercise mitigated aortic and carotid pathology by reducing aortic root diameter, PWV, and carotid wall thickness, while restoring carotid distensibility and posterior cerebral artery blood flow, especially in female MFS mice. Sex-specific analyses showed that aortic PWV was a strong predictor of posterior cerebral artery blood flow and pulmonary artery flow in males, whereas sinus of Valsalva diameter strongly predicted carotid artery PWV and wall thickness in both sexes. However, the relationships involving arterial distensibility differed between males and females. These findings highlighted the vascular impact of MFS, the therapeutic potential of exercise, and significant sex-specific differences in disease progression and associated metrics
The Curious Case of Copper: Copper’s Novel Stress Response and its Effect on Combined Stress
No full textCells encounter various forms of stress over time–oxidative stress, protein misfolding, DNA damage–and respond by activating specific, well-defined stress response pathways. As we age, the burden of stress increases while our cells’ ability to deal with the resulting damage becomes diminished due to dysregulation of cellular stress response pathways. Copper is a well-studied physiological stressor that is implicated in a variety of age-associated diseases such as cancer, cardiovascular disease, and many more. Though generally considered to be an oxidative stressor, here I describe a novel stress response where copper creates toxicity through an alternate mechanism in C. elegans. I show that this toxicity is independent of the oxidative stress response and several other canonical stress response pathways and is dependent on several genes previously unassociated with copper stress. Next, I describe copper’s protective mechanisms over several other physiological stressors and show that, similar to the individual stress response, this protective mechanism is independent of the oxidative stress response. I select the CuSO4- NaCl combination for further investigation and begin to characterize the genes involved in the C. elegans transcriptional response to the combined stress, identifying several key genes with functions related to immune response, protein processing, and membrane carbohydrate binding activity. In addition to the copper work, I also develop a protocol for longitudinal monitoring of individual worm lifespan, healthspan, and fluorescence in an environment that mimics manual agar lifespan assays. Finally, I propose a set of guidelines for the C. elegans stress response field in order to set standards for experiments and make future work more directly comparable
Epidemiological Surveillance of Long Covid in Southern Arizona: A Comparative Study of Active vs. Passive Surveillance
No full textThe emergence of post-COVID-19 conditions (PCC), now commonly referred to as Long COVID, presents a major public health challenge due to its heterogeneous symptomatology, uncertain clinical course, and lack of standardized diagnostic tests. Surveillance of Long COVID is essential for understanding its burden, but traditional infectious disease systems are not well suited to monitor a condition that bridges acute and chronic disease domains. To address this gap, the Centers for Disease Control and Prevention (CDC) launched Tracking the burden, distribution, and impact of Post COVID-19 conditions in diverse populations for children, adolescents, and adults (Track PCC), which integrates active surveillance through structured, participant-reported surveys with passive surveillance using electronic health record (EHR) data. This dissertation leverages Track PCC data from Arizona, a state with historically high COVID-19 cases and diverse populations, to evaluate and compare active and passive surveillance methods for Long COVID. Aim 1 developed and applied a standardized framework that harmonized survey symptoms and EHR-based diagnostic codes into 24 shared domains across cardiopulmonary, neurological, gastrointestinal, psychiatric, sensory, and dermatologic systems, while also identifying domains not amenable to cross-system comparison. Aim 2 applied this framework to quantify prevalence differences: active surveillance consistently captured a broader range and higher prevalence of symptoms, including milder and fluctuating conditions often absent from EHRs, whereas passive surveillance more frequently identified clinically coded conditions such as cardiovascular and psychiatric diagnoses. Logistic regression confirmed that surveillance system type strongly predicted symptom capture, with evidence of effect modification by age and race for selected domains. Aim 3 characterized temporal dynamics, revealing that self-reported symptom onset typically occurred within weeks of infection and persisted across surveys, whereas first provider-documented diagnoses in EHRs were often delayed by three to twelve months, varying by domain. These delays highlight the gap between lived experience and clinical recognition. Overall, findings demonstrate that while active surveillance is sensitive to early and diverse symptom capture, it is limited by follow-up and recall. Passive surveillance provides clinically verified diagnoses at scale but underrepresents less severe or inconsistently coded symptoms, leading to diagnostic delays. Together, these results underscore the complementary nature of the two approaches and suggest that hybrid models may provide the most complete and timely picture of Long COVID burden. By systematically harmonizing and evaluating surveillance approaches, this dissertation advances methodological innovation in Long COVID monitoring and informs strategies for more comprehensive, equitable, and responsive surveillance of emerging chronic conditions with infectious origins
Towards an Understanding of Protein–Membrane Interactions: Lipid Bilayer Mechanics and Deformations in the Presence of Integral Proteins
No full textPlasma membranes play an essential role in cellular function and biological processes. Lipid bilayers create the boundary for cellular structures, including the membrane, internal vesicles and allow intra- and extra cellular transportation. Elastic and geometric properties of these structures are of interest in the theoretical and computational exploration of the role of membranes in cellular function. From Helfrich's work to recent curvature-tilt models, continuum approximations are often limited and overlooked, or fail to incorporate all factors
that can influence the membrane shape and function. The use of continuum models allows for the prediction and direct simulation of membrane mechanics based on material properties.
Additionally, continuum models are useful to connect molecular level interactions to larger scales, allowing for the development of cellular level computational models. This work incorporates the results of all-atom molecular dynamic (MD) simulations into a curvature-stretch-tilt continuum model that accurately recreates bilayer buckling, lipid orientation, and strain. These simulations and equations allow us to determine the stretching, bending and tilt moduli of lipid bilayers, matching experimental and simulated measurements for POPC bilayers. An application of this model is in the analysis of membrane-protein interactions based on lipid bilayer mechanics, which helps in the understanding of membrane permeability and the conditions for it to happen. The findings of this research will serve as a valuable reference for future investigations into the role of lipid membranes in cellular processes
UNM Altitude Chamber Operations for Pressure Suit Demonstrations
No full textImmediate accessThis item is made available by the University of Arizona Center for Human Space Exploration (CHaSE) with support from the University of Arizona Libraries. If you have questions, please visit https://www.b2science.org/center-human-space-exploration-chase