• Self-Management in Healthcare Transition for Adolescents with Renal Transplants and Their Caregivers

      McEwen, Marylyn M.; McCaffery Sweeney, Kathleen; Loescher, Lois J.; Peek, Gloanna J. (The University of Arizona., 2020)
      Purpose: The purpose of this qualitative descriptive study was to explore facilitators and barriers, tension and influence in transition from dependent to independent self- management for adolescents with kidney transplants and their caregivers. Background: Adolescents with kidney transplants must adhere to ongoing and complex self-management regimens as they transition from dependence on their caregiver to assuming greater independence. This developmental and health illness shift occurs simultaneously within the context of the adolescent-caregiver dyad as the adolescent strives for autonomy and the caregiver relinquishes control. This shift also coincides with the time frame prior to the highest incidence of kidney graft failure in early adulthood, and correlated with poor self-management. There has been no known research exploring the perspectives of both adolescents with kidney transplants and caregivers during this critical time frame focused specifically on facilitators, inhibitors, role tension and caregiver influence. Theory: Meleis’ transition theory provides a foundation for this research. Alignment of the study findings specific to adolescents with kidney transplants and their caregivers is proposed. Methods: Qualitative descriptive methodology was employed with data collection consisting of semi-structure interviews. A total of 18 dyads, nine adolescent kidney transplant recipients, and their respective caregivers were enrolled and completed the study. Data analysis occurred through qualitative content analysis. Results: The overarching theme emerging from the narratives was liminality, the sense of being in transition. Three additional themes emerged from this main theme: 1) Pre-Transplant Experience:” 2) “Post-Transplant Experience;” and 3) “Impact of a Pandemic.” Adolescent and caregivers viewed the experience from a temporal order of diagnosis, management of renal failure, receiving the transplant, and post-transplant care. The unique complexity of the diagnosis of end stage renal disease and kidney transplantation, and the situational context of the COVID pandemic was expressed. Participants perceived facilitators and inhibitors at the individual and interpersonal level, and recognized the dyadic influence and role shifts in moving from dependent to independent self-management. They also expressed the influence of the health care team in facilitation of successful transition to independent self-management. Discussion: Successful transition to adolescent self-management exists within the context of the shared relationship between the adolescent and caregiver, is impacted by factors including age of diagnosis and level of dependent care pre-transplant, and is greatly influenced by the consequences of poor adherence post-transplant. Inhibitors to successful self-management may be mitigated by a focused assessment of the unique perspectives of both adolescents and caregivers, while recognizing the significant role of the health care team provides opportunities for targeted therapeutic interventions in support of the dyad.
    • Platelet Biomechanics and the Composition of Structural Elements Are Influenced by Mechanical Stimulation and Affect Mechanoresponse

      Slepian, Marvin J.; Sweedo, Alice; Saavedra, Scott S.; Purdy, John G.; Cohen, Zoe (The University of Arizona., 2020)
      Thrombosis is a significant cause of morbidity and mortality in patients with ventricular assist devices. The activation of platelets by physical forces in these devices is understood to be a major driver of thrombosis in this patient population, and is an event which is not blocked by current anti-platelet or anticoagulant pharmaceuticals. Such cellular reactivity to physical forces requires some form of sensation mechanism on the exterior of the cell and the transmittance of the physical signal into a chemical signal on the interior of the cell. The membrane and the cytoskeleton are interconnected elements which are known to allow other cell types to interact with their mechanical environment. These two elements maintain the “architectural” aspects of structure and shape as well as playing roles in cellular function and signal transduction. As structural molecules, these components are capable of re-distributing forces applied to the cell. Both are furthermore known to undergo dramatic rearrangement on platelet activation. Therefore, we hypothesize that the constitutive composition and arrangement of the membrane and cytoskeleton play an important role in platelet biomechanics such that these properties are altered by shear stress and that changing these properties will result in an altered mechanotransductive response.To this end, we examined the effect of shear on platelet lipid composition and mobility, evaluated the effect of membrane organization on platelet response to shear, quantified the effect of mechanical stimulation on platelet mechanical properties and cytoskeletal arrangement, and considered the potential of membrane or cytoskeletal re-organization as a “mechanoceutical” strategy for the inhibition of platelet shear response. In order to examine the effect of shear on lipid composition and mobility, we used mass spectrometry to perform a lipidomic analysis of lipids associated with and outside the platelet, and fluorescence anisotropy to determine lipid mobility within non-activated and activated platelets. We identified a unique lipid profile in shear-activated platelets indicative of non-specific loss of pro-coagulant lipid species. To investigate the influence of membrane organization on shear response, platelets exposed to the membrane modulator dimethylsulfoxide (DMSO) were examined by descriptive and functional metrics and for its ability to inhibit platelet response to shear. DMSO was determined to successfully inhibit shear-mediated activation at low doses by non-specifically decreasing membrane organization and inhibiting signal transduction. The effect of force on mechanical properties and cytoskeletal arrangement was determined using atomic force microscopy as both an imaging method and a mechanical stimuli. Platelets were found to rearrange their cytoskeleton upon the application of physical force, however this capability broke down at forces either high in magnitude or frequency. Finally, we examined potential molecules for further “mechanoceutical” applications. Although cytoskeletal modification could be successful in preventing responsiveness to shear, membrane modulation, particularly using cholesterol-like molecules, was determined to be the most promising strategy for inhibiting response to physical forces while maintaining a biochemical response.
    • Focal Volume Characterization of a Laser Scanning System

      Ellis, Jonathan D.; Whitsitt, Rebecca; Schwiegerling, James T.; Dubin, Matthew B. (The University of Arizona., 2020)
      Knife edge testing of a focused laser beam is a well-known method of observation of the position of focus. When this test is paired with pinhole scanning, a representation of the focal volume can be observed. These two methods are discussed and applied to an optical system that mimics laser-induced refractive index change (LIRIC), a femtosecond micromachining system developed at the University of Rochester to write diffractive patterns into ophthalmic hydrogels for vision correction. The focused, 405 nm, single-mode diode laser beam is modeled as Gaussian with a beam waist of 1.5 μm, and the experimentally measured waist was found to be between 8 μm. The beam quality is assessed in terms of Gaussian beam waist and the estimated beam quality factor M2, and the possibility of full characterization of the focal volume is explored. An f-theta lens is used to scan the beam, and the properties of f-theta lenses are discussed and modeled.
    • Western State FFA State Officer Selection Process: A Case Study Analysis

      Rice, Amber; Troub, Joshua; Molina, Quintin; Torres, Robert (The University of Arizona., 2020)
      Leadership selection within Western State FFA was qualitatively researched through individual interviews and focus groups with state FFA nominating committees from 2017, 2018, and 2019. A document analysis of nominating committee documents was also completed. The main question addressed was how do Western State FFA nominating committees determine quality youth leadership? Secondary research questions included: (1) What attributes do Western State FFA nominating committees’ value for quality youth leadership? and (2) How do Western State FFA nominating committees determine if state officer candidates possess these attributes? The information gleaned from this study may potentially be used by future nominating committees, leaders, and state FFA staff to inform decisions related to the leadership selection of state officers. The findings from the document analysis, interviews, and focus groups were divided into the three following categories: Nominating Committees’ Overarching Priorities for Candidate Selection, Objectivity and Subjectivity of the Nominating Committee Process, and Nominating Committees’ Skepticism towards the Selection Process. The attributes sought by the nominating committees under study did not always align with the attributes listed in state officer selection documents and loosely matched current youth leadership models. Suggestions for changing the current nominating committee process to align with the findings of this study and youth leadership research are therefore also discussed.
    • A Standard Methodology Enabling Execution of Models Described in Sysml Demonstrated in a Model Based Systems Engineering Approach Toward Developing a Space Situational Awareness System Implemented in Cubesats

      Valerdi, Ricardo; Lutfi, Mostafa; Bruyere, Donald; Lepore, Robert (The University of Arizona., 2020)
      As systems grow in complexity, Systems Engineers have embraced Model-Based Systems Engineering (MBSE) to tackle this complexity. The Systems Modeling Language (SysML) is the most commonly used language by the Systems Engineers to implement MBSE. SysML can highly express conceptual models, but struggles to demonstrate executable models. In order to perform requirements/behavior verifications, systems engineers/designers mostly use separate simulation tools. Hence, the efficiency of the systems engineering process is often reduced due to the isolated and consecutive use of both SysML modeling tool and other simulation tools, for example defining simulation inputs to each simulation tool separately. Hence, Executable SysML is the next logical step towards achieving true MBSE support for all Systems Engineering activities in the life cycle phases- system requirements, analysis, design, implementation, integration, verification, transition, validation, acceptance testing, training and maintenance. Therefore, various research efforts are being conducted to develop executable SysML Modeling approaches. This thesis paper develops a SysML Executable Modeling Methodology (SEMM), which is demonstrated by modeling a CubeSat based Space Situational Awareness (SSA) system in SysML. The SysML SSA-CubeSat System model is made executable by integrating with Commercial-Off-The-Shelf (COTS) simulation software, namely - Systems Tool Kit (STK) and MATLAB, following the approaches defined in the SEMM.
    • Metal and Metalloid Contaminants in Atmospheric Dust and Aerosol Near an Active Copper Smelter

      Saez, Avelino Eduardo AE; Betterton, Eric A. EA; Rodriguez Chavez, Tania Berenice; Sorooshian, Armin A. (The University of Arizona., 2020)
      Environmental lead (Pb) and arsenic (As) contamination still represents a potential health issue in many communities under the influence of smelter activities around the world. Activities associated with mining operations including ore smelting and mine tailings management, generate airborne metal and metalloid contaminants in a wide range of particle sizes. While fine particles (< 1µm diameter) are generated by smelting processes, coarse particles (> 1µm diameter) are produced by mechanical processes such as crushing of ore and wind erosion of mine tailings. Particle size determines the fate and transport of these contaminants in the environment and in the human respiratory system, while their content in toxic substances determines the potential risk. Fine particles can penetrate deeper in the human respiratory system.Dust and aerosols contaminated with metals and metalloid such as Pb and As have the potential of deteriorate the human health depending on the particle size and chemical composition. The main objective of this research was to determine the degree of effectiveness of penetration of dust and outdoor suspended particles containing Pb and As emitted from an active smelter complex into a school indoor environment, based on the size and composition of the particles. For this purpose, two Micro-Orifice Uniform Deposited Impactor (MOUDI) samplers were operated simultaneously in the outdoor and indoor sampling of a school located in the vicinity of an active smelter in Southern Arizona. The results showed that airborne fine particles penetrate to the indoor environment, but in a relative reduced amount due to removal of coarse particles by mechanical filtration of the outdoor air. The indoor fine fraction concentrations were around 50% of the corresponding outdoor values, however, the indoor mass concentrations of lead and arsenic, as well as mass ratio Pb/As were similar to the respective outdoor values and to the typical ratio observed in smelter emissions. On the other hand, it was found that indoor coarse particles comprised close to 20 % of the levels found in the same range of outdoor particles. Moreover, the results from the MOUDI sampling before and after an unexpected strike of the smelter company, confirmed that the main source of airborne metal and metalloids in the area is the smelter. Considering that meteorological conditions as wind speed and wind direction have an important role in the transport and deposition of contaminants to surface accessible to children, this study included a research to identify the multimedia potential risk hazard of the lead and arsenic content in aerosols, dust on playgrounds, harvest rainwater and residential soil. Furthermore, because exposure to Pb is extremely harmful to children (age 6 months-7 years), an assessment of the exposure to this contaminant was performed using the Integrated Exposure Uptake Biokinetic (IEUBK) with site specific data obtained during the study. This model allowed us to evaluate the likelihood of a child in the community under the influence of the smelter emissions to have blood lead levels above the recommended level. The results of this research can reinforce future multimedia Pb and As exposure assessments particularly those focused to evaluate the potential risk to children in schools which at the present is very limited and will be useful for future research and mitigation programs development.
    • "Nowadays, like, you can be Hispanic and not know Spanish": Language and Identity among Beginning-level Spanish Heritage Language Learners of Southern Arizona

      Gorman, Lillian; Brock Gonzalez, Stephanie; Carvalho, Ana; Huizar-Hernández, Anita (The University of Arizona., 2020)
      The present study contributes to the growing body of knowledge on beginning Spanish heritage language learners (HLL) by expanding on previous scholarship conducted in the same Spanish as a Heritage Language (SHL) program (Beaudrie, 2006; Beaudrie, 2009; Beaudrie & Ducar, 2005) and a similar SHL program in a neighboring state (Wilson, 2012). Unlike previous research, however, this study positions the local context of the SHL program (Arizona) as a central focus. This dissertation asks the following research questions: 1) What are the linguistic and cultural profiles of beginning HLLs in Southern Arizona?, 2) What attitudes towards Spanish and maintenance of Spanish do beginning HLLs in Southern Arizona have?, 3) How do beginning HLLs in Southern Arizona relate to the structure and content of their HL course(s) and how do these attitudes and perceptions relate to their goals and objectives for the course? and 4) How do beginning HLLs in Southern Arizona relate to the term heritage language learner? In what other ways do beginning HLLs in Southern Arizona conceptualize their identities as related to their perceptions of their own linguistic abilities? To answer these questions, I conducted a classroom linguistic ethnography of two sections of an advanced-beginner SHL course in one of the nation’s oldest and most comprehensive SHL programs. Other data collection tools used in this dissertation include questionnaires, surveys, focus groups, interviews, and field notes from participation observation resulting in both quantitative and qualitative data analysis. The results of this study illustrate the benefits of multiple beginning-level HL courses and shed light on the ways that beginning HLLs are transforming notions of “doing being Latinx” in the US. Furthermore, this study highlights the importance of the context of Arizona in the construction of beginning HLL identities and calls attention to the use of Spanish by beginning HLLs to resist hegemonic and racist discourses present in the state.
    • An Evaluation of Municipal Adaptation Planning in California: Climate Information Use, Access, and the Integration of Social Vulnerability

      Liverman, Diana M.; Cunningham, James; Gerlak, Andrea K.; Keith, Ladd (The University of Arizona., 2020)
      Urban adaptation plans are often predicated on knowledge of climate risks, requiring municipal planners to engage in novel ways of gathering data and using climate information, a term used for current and future climate projections and their impacts. However, few studies have assessed if and how municipal governments are acquiring and integrating climate information and how this might impact strategy development. Using content analysis and selected interviews to evaluate 26 of California’s 2012-2017 municipal adaptation plans, this study identifies (1) what climate information is used and how it supports strategy development (2) the networks and sources that provide climate information, and (3) the integration of social vulnerability concerns and public participation. I find that California’s municipalities rely on qualitative and quantitative descriptions of future climate to frame generalized threats to urban sectors and inhabitants. However, apart from sea level rise, plans do not address the location of magnitude of climate impacts within a municipality. As a result, climate information is mainly used to create a sense of urgency around climate change and support the low-cost capacity building solutions that dominate California’s urban adaptation strategies. While most municipalities consult information from state climate assessments and online climate wizards, to a lesser extent, municipalities form connections with regional commissions and local universities. These partnerships resulted in locally specific impact assessments that were used to produce tailored adaptation strategies. Despite the frequent integration of climatic variables, few plans take additional steps to identify and account for vulnerable populations within their jurisdictions. Similarly, public participation techniques are rarely incorporated into adaptation strategies but are more common in plans created by municipal staff as opposed to environmental consultants. As a result, key policy considerations for California include providing support for understanding the location and magnitude of climate impacts for multiple climate hazards, supporting the creation of additional regional commissions that can assist a greater number of municipalities, and providing incentives and tools for integrating social vulnerability and public participation into adaptation plan development.
    • Soil Dwelling Streptomyces Inhibit Arabidopsis Seed Germination

      Baltrus, David A.; White, Aaron R.; Woodson, Jesse D.; Beilstein, Mark A. (The University of Arizona., 2020)
      Streptomyces are a cosmopolitan and economically important genus of Actinobacteria known for producing an array of secondary metabolites, including many clinically relevant antibiotics. Streptomyces are ubiquitous in soil environments throughout the world and have been identified as prominent members of the microbiomes of diverse plant species. The presence of Streptomyces around and within plants has been shown to provide a wide variety of fitness benefits including increases in disease resistance and abiotic stress tolerance. Despite recent increased interest in the benefits of these bacteria to associated plants, relatively little is known about the genetic basis for the plant growth promotion capabilities shown by Streptomyces, or about the traits that facilitate plant interaction. In this work plant phenotypes resulting from inoculation with isogenic bacterial cultures are quantified and correlated with the genetic background of the bacteria used. The 9 isolates of soil derived Streptomyces influence the early growth phenotypes of co-cultured Arabidopsis thaliana Columbia-0 seedlings in a manner consistent with previously identified phylogenetic clade associations. Quantification of phenotypes of seedlings growing in association with bacterial cultures, and correlation of those phenotypes with the genetic backgrounds of associated isolates, demonstrates how results from an in vitro plant assay can be used to elucidate genomic regions with implication for plant colonization and interaction among closely related Streptomyces bacteria.
    • Creating an Empirically Based Model to Assess Infiltration Rates During Artificial Recharge at CAVSARP from 2013-2018

      Ferre, Paul; Solis-Arroyo, Sheila Sarai; Whitaker, Martha; Meixner, Thomas (The University of Arizona., 2020)
      Artificial recharge of groundwater is often achieved by infiltrating surface water into surface structures such as spreading basins. Tucson Water manages several artificial recharge projects including the Central Avra Valley Storage and Recovery Project (CAVSARP). CAVSARP consists of an intermittent multi-basin system responsible for the recharge of Central Arizona Project (CAP) water, originating from the Colorado River. Recharge basins are preferred structures for artificial recharge because they require little maintenance and are relatively easy to service. The main limit on spreading basins can be reduction in hydraulic conductivity over time due to suspended solids in surface water and anaerobic conditions. The purpose of this study is to create a simple, yet robust model that can interpret a time series of stage in the basin and measured inflow during artificial recharge periods to characterize whether the hydraulic conductivity is changing significantly over time. This could be used to trigger more detailed investigations by Tucson Water personnel to determine if a basin needs maintenance. The results of the study are in general agreement with a simpler assessment that is routinely performed by Tucson Water. However, with further refinement, it appears that the model developed here could be used to augment operational monitoring of basin performance.
    • Quantitative Microbial Risk Assessment and Community-Based Risk Perception of Sewage Overflows by Naco Elementary

      Ramirez-Andreotta, Monica D.; Gerba, Charles; Anides Morales, Alma; Reynolds, Kelly (The University of Arizona., 2020)
      Transboundary sanitary sewage overflows (SSO) have recurrently affected Ambos Nacos, sister border towns, since the late 1970s. Wastewater pollution is a major issue of concern worldwide because of the presence of pathogens and infectious microorganisms in polluted waters. The proximity of the sewage overflows to Naco Elementary School, has raised questions as to the potential health risks to the students. This is a community-inspired research project and a collaborative effort with Cochise Health and Social Services (CHSS) and Naco Elementary School. The purpose of this study was to assess the potential health risks to the students and improve understanding of risk perception and communication preferences among the school community. Following the quantitative microbial risk assessment (QMRA) paradigm, a single school day risk during a SSO event ranging from 5.08E-04 to 1 far exceeding the accepted annual risk of 1E-04. Inputs in the QMRA model included microbial analyses from superficial soil samples, and student behavior data from survey responses from teachers and parents. Qualitative coding found that approximately half of parents are not concerned or are unsure about SSO related concerns, and those who expressed concern pertained to the health and safety of their community and children, and groundwater contamination. Furthermore, 68% of parents and 50% of teachers said they had been aware of SSOs, highlighting the need for improved communication among all stakeholders (county, school, and parents). Results suggest improved communication during the occurrence of SSOs as well as action steps on how to prevent accidental exposure can mitigate a high risk of infection as calculated by the QMRA. Complementing QMRA studies with ethnographic methods to gather site-specific information can improve exposure data and inform future risk communication and management efforts.
    • HAANE’ BITS'Ą́Ą́DÉÉ’: The Process of Diné Education

      Fox, Mary Jo Tippeconnic; Begay, Waylon Nakai; Shirley, Valerie; Zepeda, Ofelia (The University of Arizona., 2020)
      This critical Indigenous qualitative study seeks to examine Diné (Navajo) students’ struggle with success in American mainstream postsecondary institutions. The aim of this research is to explore Diné graduate college student narratives about mainstream higher education and their overall purpose for attending graduate school. The heart of this research is driven by the question: What is the main purpose Diné college students attend mainstream postsecondary institutions in the United States? Two additional questions served as guides: 1.) In what ways is Diné identity & culture important at mainstream postsecondary institutions? 2.) How can mainstream postsecondary institutions incorporate more culturally based frameworks to promote American Indian student success? This study uses the unique framework of Sa’ąh Naagháí Bik’eh Hózhóón (SNBH) philosophy of balance and harmony with the Ałchi Silah (Duality) paradigm identified in Diné Philosophy to examine the overall experiences of Diné college students. In addition, this study draws upon the theoretical framework of Tribal Critical Race Theory (TribalCrit) to map out the depth and scope colonialism and neocolonialism imposes on the experiences of Diné college students in the educational environment of policies and practices, theories(stories) and school traditions of mainstream postsecondary institutions. The specific connection to student success for Diné college students is the deconstruction and reconstruction of the Diné identity in relation to the cultural landscape of U.S. mainstream universities and colleges. A narrative based inquiry (storytelling) approach is utilized to uncover successes, obstacles, and misunderstood factors of mainstream higher education in the U.S. for Diné college students. This study proposes and recommends a Diné centered epistemology to reclaim Diné identity from the hold of 21st century colonialism. A Diné centered epistemology provides within mainstream postsecondary institutions, a space where Diné identity and Diné Philosophy can flourish and benefit Diné people and surrounding communities. A space where a Diné definition of success and education can be envisioned, shared, and honored. The findings of the study emphasize that funding and academic support is needed for not just Navajo college students, but all Indigenous students. In addition, the findings illustrate a real need for an Indigenous designed space within mainstream postsecondary institutions. A site where Natives could have prayer ceremonies and collaborate alongside Native healers and leaders to create curriculum that highlights Indigenous languages and cultures. A place that houses strategic academic guidance from well-informed Indigenous teachers and leaders who work closely with Native Nation (re)Building concepts. A site that resolves inter-tribal conflicts and lets Indigenous peace and unity emerge.
    • Composable Template Attack and Evaluation of Side Channel Trace Alignment

      Lysecky, Roman; Liu, Bozhi; Roveda, Janet Meiling; Adegbija, Tosiron (The University of Arizona., 2020)
      Embedded systems are widely deployed in life-critical systems, but system constraints often limit the depth of security used in these devices, potentially leaving them open to numerous threats. Side channel attacks (SCAs) are a popular attack to extract sensitive information from embedded systems using only side channel leakage.To conduct a successful attack, common assumptions for side channel attacks are the attackers can readily and automatically identify the location of the sensitive operations in each leakage trace. However, this does not come naturally as the sensitive operations in leakage traces are susceptible to all kinds of system delays and may be located randomly. In this dissertation, we present a methodology for evaluating power obfuscation approaches that seek to obfuscate the location of sensitive operation within the power trace, thereby significantly increasing the complexity of automated trace alignment. This dissertation presents a new adversary model and proposes a new metric, mean trials to success (MTTS), to evaluate different power obfuscation methods in the context of automated trace alignment. We evaluate two common obfuscation methods, namely instruction shuffling and random instruction insertion, and we present a new obfuscation method using power shaping to intentionally mislead the attacker. Among common side channel attacks, profiled attacks, especially template attacks, have proven to be effective and widely applicable. In this dissertation, we present the composable template attack that relaxes this requirement by constructing the attack template as a composition of templates from individual architectural components, including processor, caches, and memories. The proposed approach enables an attacker to construct a template using only information of a system’s components and device models thereof. To deal with timing deviations in power traces due to unpredictable interrupts, cache misses, and microarchitectural behaviors, a novel elastic trace alignment, filtering, and points of interest selection process is utilized. Experimental results demonstrate the effectiveness and portability of composable templates attacks for 12 different system architecture configurations.
    • The White Whale: A Case Study of Sight-Singing Philosophies and Practices of Two Secondary Choral Music Educators

      Corso, Dawn T.; Campman, Jennifer Brobeck; Cossey, Alyssa J.; Williams, Matthew (The University of Arizona., 2020)
      Within the American secondary choral classroom, sight-singing instruction is a common practice, with many teachers touting its connection to building music literacy for singers. Given the plethora of available sight-singing curricula, as well as the many possible musical and instructional systems that can be used in sight-singing instruction, choir teachers can approach this subject in a variety of ways. This thesis sought to delve deeper into the backgrounds, philosophies, and rationales of two Tucson, Arizona-area secondary choir teachers in regard to the instruction of sight-singing in their choir classes. The two teachers, Mrs. Julia Higgins of Esperero Canyon Middle School and Mrs. Sarah Ross of Marana High School, were first interviewed one-on-one to gain a foundational understanding of their personal musical backgrounds, teaching philosophies and instructional choices. They were then each observed teaching “standard sight-singing lessons” to three of their choir classes. After their observations, each participant made a self-reflection in the form of a vlog to discuss the rationales behind the lessons that they taught. After analyzing the data, several categories emerged: teacher identity (subcategories: personal musical experience, instrumental music connections, perception of self, and relationship to students), musical systems and curriculum (subcategories: solfege, establishing the key, tuning and intervals, beat and rhythm, and curriculum choices), pedagogical strategies (subcategories: structure and repetition, variety in approach, modeling, feedback and assessment), and philosophy (subcategories: efficiency and fluency, connecting the mind and the voice, artistic significance and application to repertoire, fun, and student independence and growth over time). This led to a discussion of each teacher’s music teaching philosophies as they relate to sight-singing, their pedagogical strategies used when teaching sight-singing, and how these two categories connect. This study provides only a snapshot of two teacher’s backgrounds and methods, and further, broader research can and should be done to comprehensively investigate how and why secondary choral educators teach sight-singing.
    • Molecular Mechanisms Controlling Centriole Duplication

      Rogers, Gregory C.; Boese, Cody; Cress, Anne; Ellis, Nathan; Mouneimne, Ghassan; Maggert, Keith (The University of Arizona., 2020)
      Centrioles are barrel shaped, non-membrane bound organelles that typically exist in pairs where the younger ‘daughter’ centriole emanates orthogonally off of the proximal end of the older ‘mother’ centriole. The mother-daughter centriole pair and their surrounding proteins constitute the centrosome, which is the primary regulator of chromosome separation and cell division in animal cells. The centrosome controls these processes by acting as the microtubule organizing center (MTOC) of the cell – it nucleates microtubules during mitosis to form the mitotic spindle required to promote chromosome segregation. In order for proper chromosome segregation to occur, each cell needs to contain only two centrosomes entering mitosis – one at each pole to achieve spindle bipolarity. To achieve this, each centrosome must duplicate itself throughout the cell cycle. This duplication event is orchestrated by the centrioles – a single daughter centriole is built off of each mother centriole as the cell cycle progresses. The formation of excess daughter centrioles around a mother is a mechanism of centriole amplification, which is a driver of aneuploidy and tumor formation. Because of this, the process of centriole duplication is tightly controlled on a molecular level.The process of centriole duplication is coordinated in part by two conserved proteins: the Ser/Thr kinase Plk4 and its multifunctional regulator, Asterless. Previous work has shown that an excess of Asl protein levels, Plk4 protein levels and Plk4 catalytic activity can contribute to centriole amplification. Thus, it is crucial to obtain a complete understanding of how Plk4 and Asl coordinate their functions to ensure centrioles duplicate properly. It is known that Asl can regulate Plk4 by targeting it to the centriole as well as control its stability in a cell-cycle dependent manner. However, we still have an incomplete understanding of exactly how these two proteins promote the formation of a single daughter centriole during each cell cycle. Here we identify multiple new regulatory mechanisms that Plk4 and Asl utilize in order to control centriole assembly. First, we identify Asl as a multifunctional phosphorylation-dependent regulator of Plk4 catalytic activity. When dephosphorylated, Asl can bind Plk4 and stimulate its activity. Asl itself then becomes phosphorylated, and functions as a Plk4 inhibitor, invoking a negative feedback mechanism to thought prevent Plk4 from inducing centriole amplification through its catalytic activity. In the following chapter, we identify the two phospho-residues in Asl necessary for Plk4 inhibition, while also determining that this inhibition is dependent on the interaction between Plk4 and Asl. Importantly, we describe a role for this negative feedback mechanism in limiting centriole assembly: Phospho-Asl localizes to puncta around the mother centriole where they keep Plk4 inhibited. The phosphatase PP2A is then recruited to the centriole to dephosphorylate Asl at only one of the puncta, where Plk4 can then be activated to promote centriole assembly. Lastly, we reveal data that will be important for future studies on this topic, such as the mechanism of PP2A recruitment to the centriole, dynamics of Plk4 activation and inhibition, and the possible existence of an unidentified cellular Plk4 inhibitor.
    • Voices from Borderlands Theater: Activism, Resilience, and Community Engagement

      Duran, Javier D.; Arreguin, Leah; Morales, Monica P.; Romero, Elaine D. (The University of Arizona., 2020)
      This dissertation explores the cultural, historical, and political contributions of Borderlands Theater, a pioneering organization that has consistently engaged with the Mexican origin community in Tucson, Arizona. In this work, I analyze how this theater organization has produced, captured, and enhanced significant challenges and moments related to the Mexican origin populace. This analysis examines Borderlands Theater’s interpretation of the pressing issues that this community has encountered. In other words, I examine how, through the art of theater, Borderlands Theater has offered the city of Tucson a means to discuss the matters of environmental injustice, social injustice, and cultural instability within the Mexican origin identity and community, all themes of which have been purposefully set on the periphery, ignored, and even erased.
    • College Students’ Academic Entitlement, Lifestyles, and Parents

      Burross, Heidi L.; Ringquist, Austin Paul; Erbacher, Monica K.; Good, Thomas L. (The University of Arizona., 2020)
      Academic entitlement is an increasingly disrupting characteristic, affecting students, peers, teachers and professors in many different academic environments. This study reviewed the background of entitlement, investigated factors that may impact academic entitlement, as well as identified key characteristics to look for while searching for academic entitlement. A survey was administered to 397 college undergraduate students at a major southwestern university. Results from the survey used on this study included demographic items, parenting style measures, and academic entitlement items. Results from a series of separate linear regression models indicated academic entitlement is most predictive by anxious intrusiveness parenting style variable and the ethnicity variable, specifically Asian or Asian American group categorized. While these results were not statistically nor practically significant, it is worth noting future research is necessary further investigating these two variables across a wider sample. Additionally, limitations are discussed, and future research ideas are mentioned.
    • Investigation of Chalcopyrite Leaching Kinetics by Alternative Leaching Chemicals

      Lee, Jaeheon; Ahn, Junmo; Hiskey, J B.; Momayez, Moe; Gervasio, Dominic F. (The University of Arizona., 2020)
      Chalcopyrite (CuFeS2) is one of the most abundant sulfide minerals in the world copper deposit. It is known as a refractory sulfide mineral due to passivation during leaching process in a conventional leaching system. In this study, alternative lixiviants, MSA (methanesulfonic acid, CH4SO3) and sulfurous acid (H2SO3) were investigated to enhance leaching kinetic. In addition, alternative oxidants, hydrogen peroxide (H2O2), dichromate (Cr2O72-) and nitrate (NO3-) were also tested to study chalcopyrite leaching behavior in the presence of the oxidants in alternative lixiviants.Chalcopyrite leaching tests were conducted to choose the best performing lixiviant among MSA, sulfuric acid (H2SO4) and sulfurous acid with ferric at 75oC. Then, alternative oxidants, hydrogen peroxide, dichromate and nitrate were investigated with the selected lixiviant. The results of chalcopyrite leaching with various lixiviants exhibited that MSA showed the highest copper extraction of 47% with 30 g/L MSA and 5 g/L ferric. Then, copper extraction enhanced to above 90% with hydrogen peroxide, dichromate and nitrate in MSA medium. When chalcopyrite leaching was compared between sulfuric acid and MSA in these oxidant, MSA achieved higher copper extraction than sulfuric acid medium. The overall activation energy of MSA – H2O2 and MSA – NO3- leaching were 79.8 and 126 kJ/mol, respectively, indicating that the surface chemical reaction governs overall leaching kinetic. Meanwhile, MSA – Cr2O72- was determined to a diffusion controlled mechanism based on its activation energy of 21.7 kJ/mol. Results of residue characterization supported the reaction mechanism as K-jarosite precipitation on a leached residue from MSA – Cr2O72- system, which hindered mass transport and passivated chalcopyrite. Overall, nitrate leaching could be the more effective, economical and compatible than other alternative oxidants for copper leaching based on the comparative investigations.
    • Computation, Discrete Geometry, and Soft Mechanics in Non-Euclidean Elasticity

      Venkataramani, Shankar C.; Yamamoto, Kenneth Kenji; Brio, Moysey; Gillette, Andrew K. (The University of Arizona., 2020)
      This dissertation explores the ways in which the geometry of thin objects influences their mechanics, i.e., the way they respond to external forces/stimuli and the ways that they move. This is relevant to biological phenomena, e.g., in the deployment of leaves, blooming of flowers, swimming of sea slugs, etc. It is also relevant to modern technological applications of soft materials including flexible and wearable electronics. We argue that the soft mechanics and dynamics of these non-Euclidean elastic sheets are governed by interacting non-smooth geometric defects in the material. Novel ideas stemming from characterizing and modeling these defects using Discrete Differential Geometry (DDG) are presented in order to uncover fundamental insights into the elastic behavior and properties of thin hyperbolic bodies, notably the inherent floppiness of these systems. In particular, we investigate, both analytically and numerically, the energetic impacts from non-smooth defects, the role of weak external forces, and associated scaling laws. The mathematics of the DDG formulation and implementation for modeling hyperbolic sheets is also derived and described. Finally, we connect our theory with experiments by presenting Bayesian techniques for analyzing noisy profilometric data for real-world sheets as well as predictions of buckling transitions of a hyperbolic gel compressed between two plates. New theories based on the mechanics of non-smooth defects may (i) explain biological phenomena, from the morphogenesis of leaves, flowers, etc. to the biomechanics of sea slugs, as well as (ii) introduce new paradigms for materials design and actuation in a variety of new technologies, e.g., soft robotics.
    • Synthesis and Characterization of Thermally Insulating Silica-Alumina Foams

      Muralidharan, Krishna; Momayez, Moe; Rao, Pratish; Deymier, Pierre; Runge, Keith (The University of Arizona., 2020)
      Aluminosilicate derived engineering materials such as geopolymers, zeolites, Gorilla Glass, and amorphous silica-alumina systems have found immense uses as catalysts, filters, drug delivery, thermal barriers, refractory coatings, and mechanical protection systems. Partly inspired by previous investigations carried out on zeolites, and geopolymers, the focus of this dissertation is on developing a new class of silica-alumina foams (SAF) for thermal insulation applications. Specifically, using earth-abundant materials such as quartz and corundum powders as precursors, a simple, but effective low energy direct foaming based method for synthesis of thermally insulating porous foams with thermal conductivity as low as 0.08 W/mK has been established. The adopted synthesis procedure provides a straightforward avenue for obtaining closed-cell silica-alumina foams, with densities ranging from 1.7 to 0.22 g/cc. The ability to tune the densities is achieved by controlled addition of blowing agents (H2O2) and surfactants (stearic acid) respectively. The thermal conductivity of these foams decreased monotonically with increasing porosity (or decreasing densities), and the density-thermal conductivity relationship is governed by a power law. In addition, morphological, microstructural, structural, and compositional characterization was performed via a combination of optical and scanning electron microscopy (SEM), x-ray diffraction, X-ray microcomputed tomography (μCT), and nuclear magnetic resonance (NMR) methods. In particular, μCT, optical microscopy, and SEM clearly indicated the closed cell form of the foams; in addition, the ratio of average pore-size to average strut thickness decreased with increasing mass density of the foams. An analysis of SEM images demonstrated that the compositional and structural features of both the strut walls and the interior walls of the pores were very similar, primarily consisting of inorganic silica and alumina particles. SEM data also indicated that the SAF foams demonstrate a hierarchical pore structure. Further insights obtained from EDX maps, XRD data, and NMR spectra, clearly indicated the presence of a crystalline ‘film’ phase (NaAlSiO4) in close proximity with silica particles. It is hypothesized that the observed NaAlSiO4 phase is formed due to the high pH conditions pertaining to the synthesis protocols, and serves as a binder phase between constituent particles. While this work represents a straightforward and simple path towards obtaining silica-alumina foams with very low densities, the developed method is directly applicable to obtaining a wider variety of multicomponent ceramic foams.