Browsing Dissertations by Issue Date
Now showing items 1-20 of 21297
-
MRI-Guided Transcranial Magnetic Stimulation Effects on Memory, Brain Connectivity, and Brain Perfusion in Mild Cognitive ImpairmentThe urgency to develop a treatment for memory decline in pre-clinical Alzheimer's disease (AD), such as mild cognitive impairment (MCI), has prompted multiple researchers to explore transcranial magnetic stimulation (TMS) as a potential therapeutic approach. However, the outcomes have been mixed. While TMS holds promise as a tool for addressing memory decline, its mechanisms and which protocols are reliable are still the subject of ongoing investigation. In this dissertation, Chapter 1 provides a general introduction to TMS, AD, and MCI, highlighting previous TMS studies that have shown memory improvement. Specifically, we aimed to utilize a time-efficient TMS protocol known as theta-burst stimulation (TBS) across three projects. Chapter 2 features the first TMS treatment study at the University of Arizona. This study was novel in that it involved the use of connectivity-based MRI-guided TMS, with a focus on structural connectivity derived from diffusion-weighted imaging. This allowed the targeting the hippocampus, a deeply-seated memory center of the brain, which is typically beyond the reach of TMS. The results of this study suggested a probable mechanism for TMS, indicating that intermittent TBS (iTBS) stimuli may enhance memory function by transmitting its effects from the superficial cortex to the hippocampus through the inferior longitudinal fasciculus (ILF) white matter tract. Chapter 3 explores a feasibility study where we targeted the dorsolateral prefrontal cortex (DLPFC) in individuals with chemobrain, a type of MCI. This strategy is commonly employed in MCI research to ameliorate poor memory function, and we observed promising results in memory improvement, which led to the development of related superficial frontal stimulation protocols in our lab. Our findings, however, also demonstrated that the mechanism by which TMS on DLPFC enhances memory may not involve the hippocampus, and these findings prompted a departure from this approach. Chapter 4 details our final project, which built upon the stimulation strategy presented in Chapter 2. Here, we incorporated density quantitative values of the human structural connectome and utilized a graph theory approach to identify the optimal cortical stimulation sites in the parietal lobe. In light of the mixed results from previous studies, which often targeted loosely defined parietal lobes, we specifically focused on the superior parietal lobe (SPL) and inferior parietal lobe (IPL). Our discoveries highlighted the superiority of the SPL with iTBS as a more effective and promising stimulation approach with enhanced memory and increased perfusion within hippocampal subfields and regions connected via the ILF. Chapter 5 serves as a discussion that integrates and synthesizes the work presented in the earlier chapters, addressing limitations and highlighting future research directions.
-
Paleozoic to Cenozoic History of Basin Subsidence in the Sub-Andean Zone of Bolivia and Argentina (21-22°S)The Sub-Andean basin is composed of a stratigraphic record of former tectonic events that is currently involved and influences the Central Andean orogenic wedge. In this dissertation I explore a diverse dataset to constrain a long history of basin evolution and to propose implications of presented interpretations on questions that improve the knowledge of the basin. By analysis of subsurface data (well logs and seismic reflection profiles) coupled to field geology and geochronology/thermochronology I provide models of basin subsidence for the Silurian-Devonian, Carboniferous-Permian and the transition from Mesozoic-Cenozoic to the Andean foreland basin setting. In the second chapter, I describe the Silurian-Devonian from outcrops in the Inter-Andean zone, was interpreted in terms of key stratigraphic surfaces and extended into the subsurface beneath the Chaco plain. I found that basin subsidence changed between Silurian and Devonian periods, and that the Devonian defines an intra-cratonic basin setting with a depocenter farther northeast. In addition, northward variation of thickness and lithofacies oblique to the Sub-Andean ranges modifies the mechanical stratigraphy and the style of Andean deformation along strike. In the third chapter, I briefly discuss the Carboniferous-Permian record and provide novel geochronological constraints that help to clarify the widely argued depositional age and timing of the transition from a glacial to post-glacial setting, in addition to recycling of sediments among subsequent units. Another novel geochronological result is provided in the fourth chapter to support the interpreted position of a major regional unconformity below the Tacuru Group, coeval with formation of uplifted archs surrounding the region (Izozog, Michicola and proto-Eastern Cordillera) and denoted by incursion of exotic zircon ages in the basin that contrast with the prevailing Paleozoic record. These arches were the core for later formation of the system of Mesozoic rifts. In the fourth chapter I also interpret the arrival of foreland subsidence by Andean tectonics, refined by new geochronological results and along-strike correlations of seismic and stratigraphic events. I discuss the known events of foreland basin advance with the growth and style of structures along the Sub-Andean foothills. These events are extended across the Sub-Andean ranges to constrain thickness control points that were restored from their deformed locations to exhibit the shape of the stepwise flexural profiles. These profiles were then inverted by flexural modeling to present a profile of elastic thicknesses that best represents the region. The results point toward a required bimodal lithosphere rigidity with elastic thickness of ~20 km beneath the western Sub-Andean ranges and above ~50 km eastward toward the craton. Finally in the firth chapter, based on new low-temperature thermochronological data (apatite fission track and apatite (U-Th)/He) and compared with previously published data and remodeled previous results, I propose a regional thermal history for the easter Eastern Cordillera and the Sub-Andean zone. This reconstruction takes into account both palinspastically restored structural cross-sections and the results of sequential flexural modeling to produce a regional history of cooling and inferred exhumation for the Central Andean orogenic wedge at 21-22°S.
-
Discovery and Characterization of a Glycogen Synthase Kinase- 3 Small Molecule ActivatorGlycogen Synthase Kinase 3 (GSK-3) functions as a consistently active serine/threonine kinase that is positioned at the intersection of numerous signaling pathways, effectively regulating the activity of numerous substrates. Its activity is regulated by multiple upstream signals, leading to alterations in the substrates it regulates. Given its pivotal role in significant pathways such as cellular proliferation, cell cycle progression, metabolism, and adhesion, GSK-3 kinase activity is tightly regulated and modulated. Dysregulation in its signaling and, as such, its downstream targets can contribute to disease. In several cancers, including colorectal cancer (CRC), aberrant signaling due to mutations in upstream proteins regulating GSK-3 leads to pathological inhibition of its enzymatic activity. Loss of GSK-3 kinase activity can also increase resistance to specific chemotherapeutic and targeted therapies. Its central role in signaling pathways, downregulation in cancer, and its role (or lack thereof) in therapeutic resistance make GSK-3 an ideal therapeutic target. However, there are currently no known compounds that can directly activate GSK-3 kinase activity. Studies on GSK-3 suggest the possibility of allosterically activating its enzymatic activity. Thus, we hypothesize that a small molecule can enhance GSK-3 kinase activity, restoring its downstream function in conditions with pathologically low enzymatic activity. This study aims to identify a novel GSK-3 small molecule activator and explore the impact of restoring GSK-3 kinase activity in both normal and CRC conditions.In this study, we conducted a high-throughput screening of 50,000 small molecule compounds and established a systematic approach to screen and identify a compound capable of activating or enhancing GSK-3 enzymatic activity. Following multiple screens, we narrowed down our initial pool of compounds to the top 35 hits. We then utilized in-vitro kinase assays alongside cell-based assays measuring the expression of GSK-3 direct substrate and activation of Wnt signaling. This further refined our top hit to a single compound, GA33. Subsequent investigation into GA33 confirmed binding to GSK-3 in cells and its dose-dependent increase in GSK-3 activity. We found that GA33 enhanced GSK-3 mediate phosphorylation of multiple GSK-3 substrates, including β-catenin. GA33 exhibited a dose-dependent inhibition of β-catenin expression post-Wnt stimulation. In addition, GA33 treatment also inhibited Wnt signaling downstream of the GSK-3/β-catenin axis. GA33-mediated inhibition of β-catenin and Wnt signaling was also observed in CRC lines. While prolonged exposure to GA33 exhibited decreased cell viability at high doses in various CRC lines, a significant discovery was the enhanced sensitivity of CRC lines to an mTOR inhibitor, Rapamycin, upon GA33 treatment. Lastly, our study revealed that treating organoids with GA33 over an extended period influenced their growth and organization. In conclusion, the work presented in this dissertation unveiled a novel GSK-3 small molecule activator for the first time. This discovery holds importance not just for its potential therapeutic applications related to GSK-3 but also as a valuable tool for advancing our understanding of GSK-3’s structure and function.
-
Conservation Genomics and Viromics of Sonoran Desert FelidsHuman population growth, urbanization, and reductions in critical wildlife habitats are drastically reducing biodiversity. Further, anthropogenic factors impact pathogen evolution, and emerging disease poses threats to wildlife, domestic animals, and humans. Small, threatened wildlife populations, which have less genetic diversity, are particularly vulnerable to further population decline related to disease or anthropogenic impacts. Therefore, conservation priorities should include studies of both disease threats and host genetic variability. In this dissertation, I present host and viral genomic studies of Sonoran Desert felids, highlighting important considerations for future wild felid management. In Appendix A, I describe three novel circovirus genomes detected in the feces of Sonoran felids. These genomes represent two distinct circovirus species, and the first to be described associated with felids. Circoviruses are associated with disease in other vertebrates, so future monitoring of these viruses in populations of Sonoran felids and their prey is of interest for promoting felid health and conservation. In Appendix B, I compare the DNA virome composition of pumas (Puma concolor) and bobcats (Lynx rufus) in Sonora, Mexico. I observed diverse circular DNA viruses in both species, and found pumas had greater levels of virome diversity, possibly due to bioaccumulation of pathogens in apex predators. I additionally found that, although there was considerable overlap in virome composition between the two species, there were significant differences that could be attributed to host species. This study contributes to the growing body of knowledge of wild felid viral diversity. In Appendix C, I combined SNP-based pedigree reconstruction with GPS data to test home range sharing among mother-daughter pairs of urban bobcats in the Tucson Mountains, Arizona. In this study, every mother identified as having at least one daughter shared home ranges with one daughter, while other confirmed daughters established adjacent home ranges. This study provides substantial support for female philopatry and male-biased dispersal, as well as for the mother-daughter home range sharing hypothesis and matrilineal land tenure. As human populations and urbanization continue to expand, it is crucial to investigate disease, behavioral, and genetic consequences to wildlife in anthropogenically altered habitats.
-
Multiplexing for DMD-Based Near-to-Eye DisplaysAugmented Reality (AR) devices optically superimpose information over the real world through an optical channel, which often involves an angular bandwidth limited image guide employing Total Internal Reflection (TIR) due to material refractive index constraints. This bottlenecks to packaging size and couples it to the Field of View (FOV) and resolution. Previous architectures have focused on physically increasing the pixel count while reducing pixel size to combat this trade off, while still obeying the inverse relationship between the two. This dissertation discusses and demonstrates two multiplexing methods to address the challenge. By applying wavelength and time multiplexing similar to what is used in optical communication along with newly developed diffraction multiplexing increases the effective optical bandwidth for the AR display. Wavelength multiplexing with two wavelength sources are alternatively used in time sequential manner to in-couple the optical information through the bandwidth limited image guide, to effectively double the physically limited FOV of the image guide. At the output coupler of the image guide, a wavelength sensitive Volume Holographic Grating (VHG) angularly reflects and redistributes each part of the FOV to present a seamless full FOV image. Diffraction multiplexing in time is done by using the Digital Micromirror Device (DMD) in a diffractive manner that produces spatial modulated images at discrete angles, where each FOV per wavelength is further divided into sub-FOVs per each diffraction order. In the projection system, there is a FOV shifter then shifts the sub-FOVs side-by-side and creates a full FOV image. This multiplexing method reduces the display size while maintaining the image resolution, breaking the trade-off between package size and FOV/resolution. The added benefit of this method is that the bulky optics required for the FOV shifter can be placed closer to the image guide, reducing the overall display package size near the temple of the glasses. Demonstration systems of each method were built and shown with static images, with quantitative image metrics, contrast, uniformity, and crosstalk used to compare performance loss caused by the complex multiplexing. These architectures demonstrated a hybrid approach Near-to-Eye Display (NED) projection system that combines multiple domains of multiplexing, to increase the FOV of NED without the typical package volume, FOV, resolution, and energy consumption trade-offs. Showing the untapped potential of multiplexing on DMD-based NEDs.
-
Utilizing Cultural Humility-Based Training for Assessing Racial Trauma Symptoms in African AmericansPurpose. The purpose of this DNP project was to evaluate the impact of a culturally humility-based training intervention on the motivation, knowledge, and confidence of mental health providers (MHP) in delivering patient-centered culturally sensitive (PCCS) care for African Americans with racial trauma.Background. This intervention addressed the significance of assessing for racial trauma symptoms in African American patients within mental health care, with a particular emphasis on the Trauma Symptoms of Discrimination Scale (TSDS). Existing literature underscores the significance of cultural competence and sensitivity in providing effective care to diverse populations. Racial trauma, linked to experiences of discrimination, is identified as an imperative concern affecting mental health outcomes in African Americans. The gap in provider training regarding racial trauma recognition and management necessitates targeted interventions. This intervention built upon the foundation of cultural humility, aimed to enhance PCCS care through a structured training program focused on assessing and addressing racial trauma symptoms in African Americans, utilizing tools such as the Trauma Symptoms of Discrimination Scale (TSDS). Methods. This project employed a quasi-experimental design to assess the effectiveness of cultural humility-based training in enhancing MHP abilities to recognize and manage racial trauma symptoms in African American patients. The intervention involved an asynchronous online training presentation, including a clinical scenario simulation, and utilized pre- and post-training surveys for quantitative data collection. Statistical analyses, including paired-sample t-tests, evaluated shifts in motivation, knowledge, and confidence. The intervention followed the Plan-Do-Study-Act model, to ensure iterative refinement based on participant feedback. Data was securely collected and analyzed using Qualtrics and Microsoft Excel, respectively. Results. Three participants completed both the pre- and post-intervention surveys. Following the educational intervention, project data demonstrated a consistent knowledge base among participants after the cultural humility-based training intervention. However, notable positive shifts were observed in provider confidence and motivation. Specifically, two out of three participants showed improved confidence scores, with one participant experiencing a four-point increase and another a two-point increase. Moreover, motivation scores increased for two participants, one by two points and another by one point. Out of the nine pre- and post-survey questions, none demonstrated statistical significance which suggests findings may be due to chance. Conclusions. This DNP project highlighted the potential of cultural humility-based training to positively impact MHP confidence and motivation in delivering patient-centered, culturally sensitive care for African Americans with racial trauma. The findings underscore the need for ongoing education and tailored interventions to address racial trauma recognition and management in mental health settings.
-
A Summative Evaluation of a Remote Medication Titration Program for Patients with Heart FailurePurpose: This DNP program evaluation aimed to provide a quantitative retrospective analysis of the outcomes and impacts of a remote heart failure (HF) guideline-directed medical therapy (GDMT) titration program implemented at the Mayo Clinic in Arizona.Background: Heart failure (HF), whether chronic or progressive, increases mortality, morbidity, healthcare consumption, and costs. Despite significant diagnostic and therapeutic advancements, long-term heart failure management remains a challenge. Based on available research, it is possible to conclude that remote titration of guideline-directed medical therapy for heart failure leads to higher usage and optimization of said medications. Until now, a thorough evaluation of the remote titration program for heart failure medical therapies has not been conducted at Mayo Clinic in Arizona. The primary objective of this summative program evaluation was to determine the effectiveness of the remote titration program in accomplishing its goals. Methods: A retrospective data analysis of the remote titration program was conducted between March and May of 2023. A report was generated within the electronic health records (EHR) identifying 605 qualifying patients. A two-ladder approach was used to reach a sample size of 200 patients. The sample size was assessed to ascertain the proportion of participants who achieved their personalized target dose. Additionally, the study investigated whether the completed protocols were finalized within 180 days and, if not, the duration required to titrate the heart failure medications. Lastly, the evaluation identified perceived barriers to optimizing heart failure therapies. Results: Data analysis revealed that 30% of participants successfully attained their personalized targeted dosages. In this cohort, 90% of patients, reached their individualized target doses within 180 days, with a mean duration of 102.3 days in the total sample size. Hypotension emerged as the primary impediment to patients achieving target doses of their individualized protocols. Conclusions: The study showed evidence that the remote nurse-led and protocol-driven heart failure guideline-directed medical therapy titration effort was effective. This intervention increased the prescription of GDMTs while improving left ventricular ejection fraction and decreasing natriuretic peptide levels in patients. The evaluation results give empirical support for the program’s basic principles and assumptions.
-
Patient Education to Increase Self-Blood Pressure Monitoring Understanding and Cardiac AwarenessPurpose: The purpose of the DNP quality improvement (QI) project was to create an educational seminar to improve participant awareness of hypertension, mitigate hypertension risks, and encourage self-blood pressure monitoring (SBPM).Background: Cardiovascular disease is one of the leading causes of morbidity and mortality. Hypertension is considered a critical risk factor for heart attack, stroke, and heart disease. An estimated 1.28 billion adults aged 30-79 are affected with hypertension. SBPM is one way to address poorly controlled hypertension. Methods: An educational seminar about hypertension and self-blood pressure monitoring was provided at a primary care site. A recruitment flyer and handouts were given to patients with hypertension to invite them to join the QI project. The 30-minute seminar included a PowerPoint presentation on the poor cardiovascular outcomes associated with hypertension and why and how to perform SBPM. A post-survey was used to evaluate participant’s increased understanding of hypertensive outcomes and SBPM. Results: There were eight participants on the seminar date. There was improved knowledge about hypertension and the risk of uncontrolled blood pressure. Participants strongly agreed that they better understood self-blood pressure monitoring. The post-survey also indicated that patients were satisfied with the seminar and intended to use SBPM at home. Conclusions: In this quality improvement (QI) project, an educational seminar about SBPM improved patients’ knowledge about the intervention and risk factors associated with uncontrolled hypertension. The responses from the project were positive and impacted participants’ intent to use SBPM.
-
A Program Evaluation of Ketamine Assisted Psychotherapy for Treatment-Resistant DepressionPurpose: This program evaluation analyzed the effects of a ketamine-assisted psychotherapy (KAP) program for treatment-resistant depression (TRD) at a private mental health practice located in Tucson, Arizona. This program evaluation sought to specifically assess its effect on its patients’ depressive symptoms, based on their pre- and post-treatment Patient HealthQuestionnaire (PHQ-9) scores. Background: TRD is an increasingly prevalent psychiatric condition that is typically characterized by a lack of remission in depressive symptoms after undergoing two or more treatments for depression. Ketamine has been used off-label as an alternative pharmacological treatment for depression and other psychiatric disorders such as post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD). Research on the use of ketamine for the treatment of psychiatric disorders shows effectiveness at reducing symptoms of depression as well as other mental health disorders. Methods: Since June 2021, TCA has implemented a KAP program and had 38 participants participate in it to date. The effects of TCA’s KAP program on these patients’ depressive symptoms were analyzed by evaluating their pre- and post-treatment PHQ-9 scores. Results: After conducting paired t-tests, a statistically significant change was observed in all patients as well as just those patients who were actively diagnosed with major depressive disorders (MDD) pre- and post-treatment PHQ-9 scores. Descriptive statistics also showed that most patients participated in an average of 6 KAP sessions during their time at TCA, and the patients who appeared to have the greatest change in PHQ-9 scores throughout treatment were those who presented with severe depression (per PHQ-9 rankings) at baseline. Conclusions: The program evaluation of the KAP program at TCA provides an opportunity to detail the construction of a psychiatric treatment modality that currently does not have a set parameter of guidelines regarding how one should be structured. With a topic such as KAP which has room to expand upon within the research, program evaluations can offer an evaluation for relevant stakeholders into the benefits of their program and provide others with an understanding of how the KAP program at TCA functions.
-
Exploring Indigeneity in English Language Teaching Through Turi Aisa Ya With Indigenous Miskitu Teachers of EnglishThis dissertation explored the aspect of Indigeneity as a significant consideration in English Language Teaching (ELT); and thus makes a critical contribution to the literature in ELT/TESOL and applied linguistics. This body of knowledge benefits from privileging Indigenous ways and Indigenous knowledge in research practices, making explicit understandings on language use and language teaching and learning from Indigenous knowledge systems, Indigenous and postcolonial sites, and incorporating ethical approaches to research that empower all parties involved (Norton and Tohey, 2011; Pennycook & Makoni, 2020; Sterling & De Costa, 2018). As such, this dissertation was informed by Indigenous and decolonizing research methodologies that contribute to decoloniality and the advancement of Indigenous knowledge in academia. The exploration of the aspect of Indigeneity in ELT was conducted by investigating the stories and experiences of two Indigenous Miskitu teachers of English from Honduras. Additionally, the exploration includes a prologue in which the principal researcher narrates the awareness of his Indigeneity as Indigenous Chorotega in storying his life history. Consequently, I define Indigeneity as a quality of being Indigenous encompassing: as embracing Indigenous worldviews, paradigms, and ways of being, doing, knowing, and thinking (Garroutte, 2006; Huaman, 2022; Peltier, 2021); as the self-identification as Indigenous; as the awareness and interest on one’s spirituality and well-being; as the use in, interest on, and passion for one’s Indigenous language and culture (Huaman, 2022; Peltier, 2021); as the connection to Indigenous people by blood, kinship, or ancestry (Garroutte, 2006; Simpson, 2011) as well as to one’s Indigenous land, place, and community (Absolon, 2011; Sarivaara et al., 2013). The study investigated the stories and experiences of two Indigenous Miskitu teachers of English as former students of an ELT program in Honduras and current teachers of English in the public education system of Honduras. It sheds light in understanding how the Indigeneity of these Indigenous Miskitu teachers of English intersected with their preparation and professionalization as English language teachers and how their Indigeneity informs and impacts their teaching praxis. The study used turi aisa ya, an Indigenous Miskitu methodology, for data collection (Smith, 2012). Turi aisa ya is a space for sharing and the exchange of information and experiences; it requires sitting down and listening with humbleness and intention—listening to hear. Turi aisa ya is also a social activity in which participants engage in laughing, thinking together, crying, worrying, and coming up with solutions. It is imagining, experiencing vicariously, and feeling. In a similar manner to sharing circles (Lavallée, 2009), turi aisa ya is an approach “used to capture people’s experiences [and is] comparable to focus groups in qualitative research” (p. 28). In addition to turi aisa ya, the participants engaged in storywork as we were storying our intersecting lived experiences as a way of making and gaining insights from our life stories (Archibald, 2008). Engaging in turi aisa ya and storywork created the space for dialoguing about their beliefs on education merging traditional Miskitu worldviews with English language learning, English language teaching, and their lived experiences teaching in the Honduran public education system as Indigenous Miskitu teachers of English. Findings shows that the Indigeneity of the Indigenous Miskitu teachers of English, who were co-researchers on this study, was important and influential in their becoming teachers of English. First, their Indigeneity is understood as anchored in intergenerational relations as well as family and community relations, thus informed their desires to become teachers of English. Secondly, their awareness and consciousness towards the English language informed their becoming as teachers of English. Such awareness and consciousness served as a reminder on why pursuing a bachelor’s degree in ELT was relevant to them. Third, their personal traits of hard-work, resolution, commitment, and determination, aspects of their Indigeneity, intersected with their becoming as teachers of English. Said personal traits ensured that both Zoila and Wesley negotiated and navigated newer spaces and situations as they moved to new locations to pursue higher education and invested themselves in mastering English as their third language --a language that for them served community-oriented, professional, and academic purposes. Moreover, the dialogues held during the turi aisa ya sessions helped identify the ways in which their Indigeneity manifests in their teaching praxis. Their Indigeneity is manifested in their teaching praxis as reciprocity in the classroom, through the centering of well-being through a pedagogy of kindness and care, via culturally responsive teaching, and in the use of storytelling as a pedagogical tool. While these are some of the ways in which their Indigeneity is manifested in their teaching praxis, they are not the only ones considering that, as Zoila stated, “[their] Indigeneity is present in everything [they] do” (Zoila, Turi aisa ya session # 4 with Zoila. Jan, 13, 2023). Furthermore, the curricular innovations to the ELT teacher education program in Honduras, that emerge from their stories and experiences, include: (a) a class to learn about Indigenous Miskitu ways, (b) English language [pre-service] teachers learning about the linguistic diversity of Honduras, (c) representation in faculty and instructors, (d) additional preparation for students in the ELT program to teach in the public education system of Honduras, (e) formal academic and educational spaces to learn about the current state of Indigenous communities in Honduras, and (f) training students in the ELT program under the paradigm of Teaching English as a Global Language from an Indigenous relational paradigm. Key conclusions and implications for ELT teacher education in Honduras and beyond are: a) English should be taught as an additional language, b) multilingualism is as an aspect of our identities as we might be trilingual individuals (users of three languages or users of two languages and heritage speakers of an Indigenous language), and c) the ways teachers of English are educated should be innovated by a new paradigm that is encompassing of multilingual education and the fact that English is a global language. Noteworthy to identify are the limitations that impacted this study. These include a lack of Indigenous knowledge in the fields of ELT/TESOL and applied linguistics, the realities exacerbated by COVID-19 even post-pandemic, and the small number of Indigenous Miskitu teachers of English. The possibilities for future research suggest that this study could be replicated with the collaboration of more Indigenous Miskitu teachers of English as well as other teachers of English who belong to other ‘ethnic’ communities such as the Garifuna and Islanders. Also, further research could instigate other critical dialogues to gain insights into the multilingual realities of all these individuals. Furthermore, this study could be replicated to learn how other Indigenous teachers of English throughout the world teach this language as informed by their Indigeneity. Lastly, further research that builds from this dissertation could investigate how the teaching of languages such as English could look like if informed by an Indigenous relational paradigm. Keywords: Indigeneity, Indigenous Knowledge, Miskitu, Honduras, English Language Teaching, TESOL, Applied Linguistics, Global Englishes, teacher education.
-
Methods for Design, Metrology, and Alignment of Scalable Large Optical SystemsOptics has been for 400 years one of the most impactful fields of science; starting with medicine and astronomy. Optical engineering challenges differ greatly across applications. Large optical systems are exponentially more costly and complex, especially when made in quantities of one. The future of astronomy demands more photons and higher resolution, thus even larger collecting area. Scalability is needed in order to keeps costs low while still producing these large collecting areas to meet demand. This dissertation explores methods for advancing concepts that enable large optical systems to become scalable. In Chapter 1, we discuss the problem of large optical systems: why they are needed, why that need is difficult to meet, and what concepts need to be implemented in order to solve some of those needs. The following chapters cover design, metrology, and alignment for large optical systems, with scalability in mind. The first work discusses optical design for the Large Fiber Array Spectroscopic Telescope (LFAST) in Chapter 2. At 30" diameter, this telescope is designed to be replicated thousands of times. Next, we discuss a novel metrology method to support efficient manufacturing of radio antenna panels in Chapter 3. Finally, we discuss using the same metrology method to form an accurate dish by rapidly align radio antenna panels in Chapter 4.
-
An Analysis and Performance Guide of Chinese Representative Viola Works by Qingwu Guan, Nian Liu, and Bright ShengThis document delves into five Chinese representative viola pieces: The Sound of the Mongolian Grassland (Caoyuan Zhige 草原之歌) by Qingwu Guan , First Suite for Solo Viola by Nian Liu, and Three Chinese Love Songs, Angel Fire Duo, and The Stream Flows by Bright Sheng. These works contain numerous uniquely Chinese musical elements including pitch collections, folk song melodies, viola performance techniques. By incorporating such Chinese elements and folk melodies into their compositions, these composers have bridged cultural gaps between China and Western countries, thereby instilling a deeper appreciation of Chinese musical heritage on a global scale. Their shared contributions to the incorporation of Chinese compositional elements into viola music has helped to foster the development of Chinese viola repertoire.
-
Development of a Self-Supervised Learning-based Approach to Clustering Multivariate Time-Series Data with Missing ValuesMultivariate time-series data are commonly found in acute care, where each patient's record is a series of clinical measurements over time, providing critical information throughout the patient's care. Clustering approaches are often used to extract valuable information and identify patterns from temporal data. However, a major challenge in real-world time-series data is the prevalence of missing values. Existing methods typically require filling in these missing values before clustering, which can introduce noise and potentially lead to inaccurate interpretations. In this dissertation, we address these challenges by proposing a novel approach for clustering sparse and irregularly sampled time-series data We also provide a comprehensive examination of how this developed approach can be applied in the identification of (a) clinical phenotypes and (b) physiological states of patients with Traumatic Brain Injury (TBI).First, we developed a Self-supervised Learning-based Approach to Clustering multivariate Time-series data with missing values (SLAC-Time). SLAC-Time employs a Transformer model and uses time-series forecasting as a proxy task for learning the representations of unlabeled data. When applied to data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, SLAC-Time outperformed traditional K-means clustering in terms of silhouette coefficient, Calinski Harabasz index, Dunn index, and Davies Bouldin index. It identified three distinct TBI phenotypes, each correlating with significant clinical variables and outcomes, such as the Extended Glasgow Outcome Scale (GOSE) score, length of stay in the ICU, and mortality rates. Second, we applied SLAC-Time for clustering TBI patients within the TRACK-TBI dataset and the Medical Information Mart for Intensive Care (MIMIC)-IV external dataset, leading to the identification of generalizable TBI phenotypes. These include: phenotype α, characterized by the lowest mortality rates and shortest ICU stays, typically observed in younger patients with balanced metabolic responses and milder clinical symptoms; phenotype β, exhibiting the highest mortality rates and longest ICU stays, often found in older patients with elevated metabolic stress, reduced oxygen transport, and significant neurological impairments; and phenotype γ, displaying moderate mortality rates and ICU stays, with clinical presentations that are less severe than phenotype β but more pronounced than phenotype α. These phenotypes provide a detailed understanding of TBI, offering critical insights for personalized patient treatment and management. Third, we applied SLAC-Time for clustering the TBI high-resolution physiological data in the TRACK-TBI dataset and identified three distinct TBI physiological states. State A is critical, with signs of brain oxygen and blood supply deficiency. State B indicates respiratory distress with inadequate oxygenation. State C is stable, showing signs of sufficient cerebral oxygenation and blood flow. Furthermore, we discovered how specific clinical events and interventions could influence these patient states and drive transitions between them, providing critical insights for tailored clinical management of TBI patients. This dissertation makes a modest contribution to the clustering of multivariate time-series data with missing values. By avoiding data imputation and aggregation, SLAC-Time highly increases the accuracy of time-series clustering analyses. The iterative representation-learning capability of SLAC-Time, effectively reduces noise in the raw input data, thereby improving the quality of the representations used for clustering. The methodologies developed throughout this work establish a foundation for precision medicine in treating TBI patients. These contributions are set to inform and direct the future of TBI management, potentially leading to substantial improvements in both our comprehension of the condition and the outcomes for patients.
-
Voices of Mexican Army WivesVoices of Mexican Amy Wives is a study about the inner world of the army, a traditionally secluded institution with a primordial role in the history of Mexico. It focuses on a group usually absent in army studies, seeking to contribute to understanding their roles, behavior, and influence. It presents written and oral testimonies of army wives chronologically from the first years of the Revolution, 1910-1924, the Social Revolution 1925- 1950s, and the Contemporary times 1960s-2016. Studying them over three periods allows readers to see changes and continuities while providing a better understanding of the institution that they are part of, showing that army wives are not passive and invisible companions and contribute significantly to the institution and their country.
-
Moving Beyond the Decolonization Framework: Indigenous Research, Collaboration, and Decision-Making in Mi’kma’kiThis dissertation is divided into three parts. Part I addresses the researchquestion, literature review, and methodologies. Part II is a treatment of original research that took place at Membertou Mi’kmaq Band between 2010 and 2013. The community centered research model is described in detail, which is followed by new analysis of data that was collected during that community-centered research. Part III discusses the context of Mi’kmaq Nation action over the last several decades. This action is influenced by the experience of Donald Marshall, Jr. in two major legal cases: 1) Marshall’s wrongful conviction and incarceration for murder, and then exoneration; and 2) Marshall’s arrest for violating provincial fishing laws, leading to a landmark decision on Mi’kmaw land, hunting and fishing, and commerce rights. Both these cases, along with evolving standards for Aboriginal rights, consultation, and accommodation, and changing institutional arrangements at Mi’kmaq led to the collaborative governance regime, the Made in Nova Scotia Process.
-
The Political Influence of Sense of National BelongingThroughout this decade, America has experienced ongoing and inevitable waves of conversation surrounding issues related to racial justice and immigration. The goal of this dissertation is to discuss the potential political effects, particularly on issues that challenge the current social and racial system and hierarchy, of a sense of national belonging—a relatively understudied form of national attachment in the field of political science. It is argued that due to the boundary-maintaining nature of national belonging, it should be associated with negative views on issues that potentially challenge the current system. This dissertation comprises one observational study, one experimental study, and one qualitative study.In Chapter 1, a preliminary view of the potential effect of a sense of national belonging on shifting system-challenging issues is provided by analyzing data from the Collaborative Multiracial, Post-Election Survey (CMPS) 2016. It is found that, in general, a higher sense of belonging is associated with pro-current racial system attitudes, such as a decrease in support for Black Lives Matter and a decreased perception of the severity of racial discrimination. Additionally, this relationship holds true across racial groups. Chapter 2 attempts to identify the causal relationship between a sense of national belonging and the shaping of racial reform issue attitudes. A survey experiment was conducted on Connect via CloudResearch with 279 participants. Due to weak treatment effects, the experiment failed to demonstrate a causal effect of a sense of national belonging on issue attitudes. However, additional observational examinations yielded results similar to Chapter 1—indicating that a sense of national belonging is related to negative views on racial reform. Therefore, it can be concluded that national belonging is one of the factors that shape attitudes but may not be the most essential one. Finally, Chapter 3 delves into the meaning of national belonging among students from the University of Arizona, School of Government and Public Policy. Thirty-nine students shared their definitions of a sense of national belonging and identified obstacles to feeling a sense of belonging. The results reveal that the construction of national belonging is reciprocal, requiring mutual commitment from both the government and citizens. Additionally, identity conflict emerges as a primary obstacle to experiencing belonging, a challenge not limited to students from minority groups.
-
Enhancing the Plant Virus Surveillance ToolboxPlant viruses are economically important pathogens of crops. Viruses exhibit extreme adaptive potential due to their quick mutation rates, extensive recombination, and horizontal gene transfer. This can lead to emergence of new viruses into our cropping systems, or the shifting of viral populations to overcome resistance bred into crops. Because of this, surveillance programs have been established to continually monitor the cropping systems for new viruses as they emerge and populations as the adapt to resistance plant genetics. In this work, three chapters detail two different surveillance methods. First, an established method for linking causality of virus infection to disease symptoms was used to characterize symptoms of an emergent Theobroma cacao infecting badnavirus (Family: Caulimoviridae), Cacao swollen shoot virus Ghana M virus. Second, a bioinformatics pipeline was written to handle target enrichment high throughput sequencing data for an endemic complex of begomoviruses (Family: Geminiviridae) infecting Gossypium spp in Southeast Asia, Cotton leaf curl disease (CLCuD). The pipeline, Virus Community Assembly Tool (ViCAT) was validated on simulated mock communities, spiked mock communities consisting of known concentrations of clones, and three plant samples harboring mixed infections of begomoviruses. Lastly, the ViCAT pipeline was used to characterize community differences of the CLCuD begomoviruses in differentially susceptible/resistant cotton lines. Together the chapters attempt to expand on the current tools in the plant virus surveillance toolbox.
-
Investigating the Impact of Learner-Centered and Co-designed Sex and Relationship Curriculum by College StudentsThe current dissertation sought to address gaps found in learner-led, co-construction around materials for sexual health education by investigating participants’ project development and gathering both quantitative and qualitative data around the experience of designing and researching the SRE curriculum. This is necessary to pursue since young adults have shared a need for expanded materials beyond comprehensive sex education and are heavily impacted by poor or missing education. A mixed-methods design was implemented via survey responses (N = 38), curriculum creation (n = 6), and interview (n = 1) data. Analyses of the curriculum creation data included thematic and multimodal techniques. Findings indicated five main areas of interest: participants’ diverse sources of sexual health information, knowledge gaps and strengths in sexual health topics, dissonance between learning preferences and implemented curriculum techniques, thematic priorities in curriculum creation, and multimodal approaches and design philosophies used by learners. In conclusion, this research serves as a foundational step, providing support for ongoing iterations of work in the field of SRE. The aim is to contribute to a continuous discourse that is essential for the well-being and quality of life within our community, among our students, and for ourselves. Keywords: sex and relationship education, learner-led, co-construction, multimodal, collaborative, sex education
-
Examining the Influence of Racial Self-Identity on Black Adolescents’ Psychological Well-Being: A Mixed-Methods Study Across Counties in Arizona and FloridaThis study used a mixed methods research design to capture the broad notions of racial identity and psychological stressors’ impact on well-being in African American youth across various counties in the states of Arizona and Florida. Several forms of psychological stressors that directly impact the natural development of self, such as external racism, internal racism, poverty, and violence, have been studied extensively within the African American (AA) community (APA, 2016; Morsey & Rothstein, 2019; Williams, 2018). Current interventions provide some relief, yet Black youth still undergo high rates of victimization, criminalization, and mental health concerns. Thus, finding many solutions to mitigate the impact of more extensive systemic policies and frameworks that uphold inequality is imperative. Increasing the use of Black Personality Theory to conceptualize Black identity in youth has been shown to lead to positive outcomes such as well-being and self-esteem (Constantine et al., 2005; Thomas et al., 2003). After exploration, evidence to support a significant difference in racial identity and psychological stressors between states was not found. However, Black adolescents in Florida reported higher levels of life satisfaction than those in Arizona. Additionally, the predictive ability of African Diasporic frameworks of identity development did contribute significantly to well-being across differing counties in both Arizona and Florida. Furthermore, trends of a solidified conceptualization of Blackness’ positive impact on well-being despite immense racial stressors were confirmed.
-
Clinician Education: Optimizing Music Choices for Ketamine-Assisted PsychotherapyPurpose:The purpose of this quality improvement project was to increase clinician knowledge regarding evidence-based music selections for ketamine-assisted psychotherapy at a local clinic. Background: Ketamine is used to treat a variety of mental health issues. Set and setting have been identified as important variables that support the tolerability and efficacy of ketamine. Music is one key variable that clinicians can utilize to optimize the therapeutic experience; however, not every provider is knowledgeable regarding how to best do this. Methods: This quality improvement project was delivered as an educational presentation for clinicians at Tucson Counseling Associates. The presentation was created based on published literature and evidence provided as a multi-media PowerPoint lecture including examples of appropriate music choices and a case study. Data was collected through a pre- and post-survey questionnaire, which was used to assess baseline knowledge and knowledge gained after the lecture. The surveys utilized a five-item Likert scale and short-answer format questions. A number was assigned to each Likert scale rating (strongly disagree = 1, disagree = 2, neutral = 3, agree = 4, strongly agree = 5) and thenumber of responses for each item on the scale was factored in. Free text responses were reviewed for major themes. 12 Results:Participant perception of current clinic practices indicated that clinicians agreed that music was intentionally selected at Tucson Counseling Associates with an average Likert-scale score of 4.43. Clinicians agreed that they understood why certain music is used for patients. The post-survey results indicated a statistically significant improvement in knowledge gain compared to the pre-survey results. Participants strongly agreed that they learned valuable information during the presentation and that they intend to use the information in their future practice. The free-response questions indicated six unique ways in which participants intend to use this new information in their clinical practice and provided insights on how to improve the intervention moving forward. Conclusions: Results suggest the efficacy of an interactive multi-media PowerPoint lecture with an incorporated case study in increasing clinician understanding and confidence in choosing appropriate music choices for KAP sessions to help optimize the patient experience.