ABOUT THE COLLECTION

The UA Master's Theses Collection provides open access to masters theses and reports produced at the University of Arizona, including theses submitted online from 2005-present and theses from 1895-2005 that were digitized from microfilm and print holdings, in addition to master's reports from the College of Architecture, Planning and Landscape Architecture from 1966 onwards. The collection includes hundreds of titles not available in ProQuest.

We have digitized the entire backfile of master's theses and doctoral dissertations that have been submitted to the University of Arizona Libraries - since 1895! If you can't find the item you want in the repository and would like to check its digitization status, please contact us.

The UA Master's Theses collection is not comprehensive; master's theses from 1993-2015 were only received and archived by the UA Library and ProQuest if the student chose to pay the optional archiving fee. The Library does not have copies of many master's theses submitted during this time period. Some academic departments may keep copies of theses submitted to their programs. Colleges and departments wishing to archive master's theses not available in the University Libraries are encouraged to contact us at repository@u.library.arizona.edu.

QUESTIONS?

Please refer to the Dissertations and Theses in the UA Libraries guide for more details about UA Theses and Dissertations, and to find materials that are not available online. Email repository@u.library.arizona.edu with your questions about UA Theses and Dissertations.


Recent Submissions

  • Novel Antennas, Matching Circuits, and Fabrication Techniques at HF and Microwave Frequencies

    Gulati, Gitansh (The University of Arizona., 2018)
    This thesis focuses on the investigation of several novel antennas including electrically small antennas for HF communication system, as well as the applications of gradient index lens based broadband multiple-beam system, and electromagnetic cloak structures in printed technology. Modern-day wireless communication systems have developed interest in the field of low-profile broadband antennas. The design of electrically small antennas (ESA) presents numerous challenges, primarily due to inherently low impedance and narrow bandwidths. Improving these performance characteristics becomes even more challenging in the high frequency (HF) band due to longer wavelengths and corresponding antenna physical dimensions. In this thesis, we propose electrically-small vertically-polarized normal mode helical antenna (NMHA), about λ/50 at the lowest frequency of operation, to facilitate robust long-range HF-band communications (3 – 30 MHz). To overcome the potential issues related to electrically-small NMHA such as impedance matching, bandwidth and radiation efficiency, passive and active impedance matching techniques are investigated. Three types of matching networks are proposed, designed and experimentally demonstrated. These include passive narrowband electronically-switched LC matching network, broadband transformers and active non-Foster broadband matching circuit. In addition, performance of electrically-small helical antenna (ESHA) matched system in terms of received signal power strength, signal-to-noise ratio (SNR), and signal intelligibility is evaluated with the help of outdoor field test measurements. Many potential areas of application such as satellite communication, air-traffic control, air-based tracking and surveillance, marine navigation, and automotive radar require highly-directional wide-angle beam scanning with minimum pattern deformation and broadband behavior, in addition to lower-cost and weight considerations. In view of this, another area of concentration addressed by the thesis is towards the development of multiple-beam Luneburg lens antenna system. The additive manufactured 3D graded-index Luneburg lens is employed for this application. Using the special property of a Luneburg lens that every point on the surface of the lens is the focal point of a plane wave incident from the opposite side, compact conformal dual-polarized all-metal Vivaldi feed array, with its phase center close to the lens surface, is proposed to realize the full potential of Luneburg lens for practical wireless applications ranging from 3 – 6 GHz. Lastly, this thesis discusses another interesting topic about electromagnetic invisibility and cloaking technology being applied to printed antennas in order to reduce mutual near-field coupling, based on the concept of mantle cloaking method. Two microstrip-fed monopole antennas placed in the near-field of each other, resonating at slightly different frequencies, become invisible to each other by cloaking the radiation part of each antenna. The cloak structure is realized by a conformal elliptical metasurface formed by confocal printed arrays of sub-wavelength periodic elements, partially embedded in the substrate. The existence of the metasurfaces leads to restoration of the radiation patterns of the antennas as if they were isolated. Finally, the fabrication of near-field cloaked prototype is carried out using advanced 3D printing techniques.
  • Development of 248nm AR Coatings for Photolithography Applications

    Bohac, Michael Thomas (The University of Arizona., 2018)
    A key application for thin film coatings, minimizing Fresnel reflections from each surface is critical to achieving high throughput for multi-component, transmissive optical systems. Assuming small, plano optics, reflection from a single laser-line operating near normal incidence can be significantly recovered using a relatively simple antireflection design. Limited in low-reflection bandwidth however, these simple designs increase quickly with angle and/or small amounts of non-uniformity, and become inadequate for large-diameter, fast systems. At ultraviolet wavelengths, the demand for throughput becomes even more challenging, driving system designs to larger apertures and faster, steeper elements. Unfortunately, many thin film materials begin to absorb strongly in the UV, limiting the number of high index options in particular. In addition to inherent material absorption, UV wavelengths are considerably more sensitive to other sources of loss such as scatter and contamination, which must therefore be minimized in combination with reflection. In this study, we studied the trade-offs between low-reflection bandwidth and absorption. By maximizing index contrast, a wider band could be achieved, but often at the expense of absorption from high index materials. A survey of materials was also conducted, where the influence of process energy on contamination was examined. Secondary attributes such as mechanical durability, UV laser damage resistance, and homogeneity were also considered. Once optimized, attention would turn toward multi-layer design and manufacturability, where development results were scaled into a robust and stable multi-layer process. In an effort to reduce the amount of bandwidth consumed by the process, sources of both random and systematic errors were addressed, uniformity minimized, and process repeatability maximized. Conversely, once angle shift and non-uniformity were accounted for, AR bandwidth determined the amount of error the design could tolerate, and thus the level-of-effort required to stabilize the process. The final combination of materials and processes achieved a preliminary loss (reflection + absorption) of 25% through 42 spherical and aspherical surfaces, exhibiting very high laser damage resistance and mechanical durability. Once demonstrated, the process was then applied to two additional systems, improving in performance with each iteration, and ultimately achieving a minimum loss of <23%.
  • Soil Microbial Activity is Stabilized by Mesquite in Recreational Campsites

    Kariuki, Sudan (The University of Arizona., 2018)
    Recreational camping often suppresses vegetation cover and expands bare ground. These shifts have important implications for plant and soil ecological health. Soil microbial activity can inform understanding of how recreation affects ecological processes. This case study uses campsites at the Santa Rita Experimental Range in Southern Arizona to test the hypothesis that the degrading impacts of camping on vegetation are mirrored in the soil microbiome. Measurements of herbaceous basal cover, microbial biomass, and enzyme activity were collected and stratified by categories of camping disturbance and mesquite (Prosopis velutina) cover. Campsites demonstrated suppressed litter, herbaceous cover, and gravimetric water content. Herbaceous cover was 53% lower in campsites than in undisturbed areas. Surprisingly, enzyme activity and microbial biomass C and N were more influenced by mesquite canopy (microbial biomass C by 55% and microbial biomass N by 52%) than by camping disturbance. In spite of observed evidence that campsite soil environments are degraded, mesquite-driven ecological processes appear to stave off degradation of soil microbial activity. However, soil microbial biomass and enzyme activity are indirectly affected by camping disturbance through the combined influence of litter, herbaceous cover, and soil moisture. Therefore, plant-soil feedbacks play an important function in determining how campsites in semiarid systems respond to disturbance.
  • The Pre-miR-27a Gene Polymorphism Rs895819 and Risk of Prostate Cancer Progression

    Daw, Jennifer Nicole (The University of Arizona., 2018)
    Small single-stranded, non-coding RNA molecules known as microRNAs (miRNAs) are capable of regulating gene expression by suppressing translation or degrading mRNAs resulting in diverse consequences. MiRNAs are synthesized as an individual primary transcript or as a gene cluster and each can act alone or together to control a single gene or a network of genes. The miR-23a~27a~24-2 gene cluster are individually processed of each other and have their own unique mature miRNA expression profile in various prostate cancer cell lines. Previous studies have reported the dysregulation of mature miR-27a and corresponding gene targets to be associated with cancer. A single nucleotide polymorphism in pre-miR-27a at position 40 (chr.19p13.1, SNP rs895819 T>C) and is proposed to affect mature miR-27a biogenesis. Rs895819 has been associated with risk of various cancers in different ethnic groups, and depending on the allele may cause up-regulation or down-regulation of mature miRNAs and pose as a risk factor for cancer. The literature evaluating SNP rs895819 is not clear with respect to its effects on miRNA processing, targeting, and its associations with PCa. In this study, we focus on miRNAs -23a, -27a, and -24-2 individually and as a cluster, and in a case-only study genotyping of rs895819 in a PCa cohort from a southwest US population consisting of a mixed ancestral background. We used a TaqMan SNP assay for genotyping rs895819 (T>C) in germline DNA samples from PCa patients and cell lines. Our data suggest rs895819 is associated with higher Gleason score sum. Based on our data we plan to investigate the miR-23a~27a~24-2 gene cluster to determine mechanisms by which these microRNAs regulate epithelial plasticity pathways in PCa.
  • Connexin37 Phosphorylation Status Determines Different Growth Phenotypes

    Weyker, Ryan (The University of Arizona., 2018)
    Cellular growth regulation can be modulated by altering the phosphorylation state of Cx37. Mechanistically it remains to be fully elucidated how Cx37 contributes to this regulation by means of: intramolecular binding partners, its function as a hemi-channel or by facilitation of intercellular communication via gap junctions. Herein we sought to examine the effects of phosphorylation by means of phosphomimetic substitutions (serines to aspartates) on proliferation and the possible alterations to the protein channel function by looking at three mutants Cx37-S275,319D, Cx37-S275,328D and Cx37-S275,319,328D expressed in rat insulinoma cells(Rin). Growth curve assays showed that cells with either Cx37-S275,319D or Cx37-S275,328D eliminated the cell death seen in Cx37-WT and previously studied Cx37 proteins with single site phosphomimetic substitutions at either S275D or S328D, as well as allowing unrestrained proliferation when cells were induced to express the protein at higher densities. Rin cells with Cx37-S275,319,328D appear to proliferate at any density without any measurable cell death. There was a reduction in the open probability for large hemi-channel events for all three non-death inducing mutants and an increased probability of hemi-channels being in the closed state for the growth arrested cells expressing Cx37-S275,319D and Cx37-S275,328D. These data suggest that differential phosphorylation could be an important factor modulating hemi-channel behavior either promoting the closed-state, and thereby facilitating growth arrest and/or preventing high current Cx37 hemi-channel openings and thus facilitating Cx37’s capacity to cause cell death.
  • Flexible Energy Efficient Design Guidelines For Climate Responsive Low-Income Housing

    Sanders, Maddison (The University of Arizona., 2018)
    The City of New Albany’s local government is proposing a renovation and demolition project to the current low-income housing options. The New Albany Housing Authority has expressed interest in high performing energy buildings for the new designs, but few plans have been produced for the project. The large-scale project has the opportunity to greatly benefit the entire city of New Albany, as well as providing environmental implications to the local and global community. New Albany is a suburban town located in the south central point of Indiana, bordering the urban area of Louisville, KY and only separated by the Ohio River. New Albany is a city with a population of roughly 35,000 peoples who primarily work the urban areas within and surrounding New Albany. Low-income housing and sustainable design are closely linked due to the nature of living conditions and budgeting low-income families face. The difference in energy and utility costs between a poor and high performing building for a low-income family could alter their financial burdens and bring them out of low-income status over time. Low-income families traditionally are forced to live in housing that is poorly cared for and constructed, creating a variety of health issues and reduces the quality of life for those who are already in crisis situations. Introducing sustainable housing to low-income families is critical to the City of New Albany as over 500 housing units are going to be demolished and redesigned to better improve the quality of life for the affected population. Proposed design strategies to be tested focus of cost effective strategies as well as the law of diminishing return. Primarily the strategies tested will be orientation, daylight, ventilation, insulation, shading, infrastructure upgrades, and geometries. The proposed geometries to be tested alongside the base case unit are as follows: single unit, duplex units, row housing units, and multistory units. The aim of this study is to test and create proven results to suggest for building design guidelines on the basis of energy performance and cost affordability and effectiveness. From this study, the efficiencies of three tiered strategies were found and tested against the differing geometries. The row-housing unit had the best initial, baseline performance and when all tiers of strategies were applied the resulting energy consumption was at 10,000 kWh equating to roughly $1,080 annually. This drastically lower cost would allow for low-income families to create change in their life and improve their overall quality of life.
  • Two Essays on Perceived Climate Change and Adaptation of Rural Livelihoods

    Kishore, Siddharth (The University of Arizona., 2018)
    For my thesis, I am going to present two essays on perceived climate change and livelihood adaptation. Using a survey data on 3,300 representative rural households from each drought as well as flood-prone regions of India, we examine the links between the households’ livelihood adaption choices and perceived climate change. The livelihoods adaptation choices are jointly modeled as the multivariate probit regression, estimated by the simulated likelihoods procedure of Cappellari and Jenkins (2003). We find that households who chose one adaptation strategy were more likely to choose another one. The adaptation choices of the households are strongly determined by their perceived climate change and the results are robust to multicollinearity among the measures of the perceptions of climate change. Among the control variables, access to information on onset of monsoon and amount of rainfall influences adaption choices.
  • Method to Analysis Daylight Strategies in Production Home Prototypes: A Case Study of the Appaloosa Plan

    Pietrack, Elizabeth (The University of Arizona., 2018)
    In an individual’s life there are several major decisions they must make, one of the most significant being what kind of home they live in. Oftentimes the home type prospective homebuyers choose is a detached, single-family residence. Of detached-single family residences in the United States production homes account for 73% of detached, single-family homes in residential new construction. Due to this high market share of detached, single-family homes being production homes it is vital to assess the quality of the homes being produced. One important lens to evaluate production homes through is the daylighting conditions of the home. The presence of daylight in architectural applications has been shown to be highly beneficial to occupants in elevating their mood, maintaining their circadian rhythms, increasing productivity and reducing fatigue. This research aims to study the daylight conditions of the base floor plan of Taylor Morrison’s Appaloosa plan in Estates at Eastmark Venture II Collection community in Mesa, Arizona as a case study to define a methodology of orientation-based optimization using a Window to Floor Ratio (WFR) calculation. The analysis of the base case Appaloosa plan showed a consistency of under-illuminated conditions in the living area as referenced against IESNA standards within the home at all orientations during the winter and over-illuminated conditions in the dining room during the summer and winter. Two redesigns were conducted including one redesign incorporating only sidelighting strategies and the other including sidelighting and top lighting daylight strategies. The results of these redesigns concluded in redesign one for the living area having an average of 25.7 F.C. for the North, 26.04 F.C. for the East, 25 F.C. for the South, and 22.85 F.C. for the West Orientation. Due to the inability of the West to reach the minimum amount of F.C. to be considered well-lit a second redesign was done and in this the West Orientation achieved 25.04 F.C. The dining room in comparison was able to achieve compliance with one redesign with results showing an average of 19.27 F.C. for the North, 18.42 F.C. for the East, 17.78 F.C. for the South, and 18.02 F.C. for the West orientation during the summer. The winter dining room in comparison was still in compliance with the range of being well-lit but tended to have results with less F.C. such as the North at 18.23 F.C., the East at 16.44 F.C., the South at 16.12 F.C., and the West orientation at 16.35 F.C.
  • Perceived Learning and Satisfaction Differences in Face-to-Face and Online Courses

    Perez, Rebecca (The University of Arizona., 2018)
    With the increased popularity of online courses, ensuring that students in online courses have equivalent learning experiences as their peers in face-to-face courses is paramount. Current research regarding the similarities and differences between the two course delivery mediums has resulted in contradictory findings, particularly in terms of how students perceive and rate the course. This analysis expands the focus comparison of student evaluation of teaching ratings means beyond that of a single course or department using correlational analysis, paired t-test, and MANOVAs. Significant differences were found between online and face-to-face courses for particular evaluation items, college, and academic level. These differences provide insight into the differences between the delivery mediums from the student perspective and can help identify pedagogical strategies to ensure equivalent learning experiences.
  • (Self)Censorship, Media Repression, and the Trajectory of Citizen Journalism in Turkey: The Evolution of 140journos

    Perugini, John (The University of Arizona., 2018)
    This research traces the evolution of 140journos, a former citizen journalist group (2012-2017) and now professional media group (2017-present) based in Istanbul, Turkey. In doing so, it connects the evolution of the group with the broader processes of censorship and media repression in Turkey. Since its establishment in 2012, I argue that 140journos can be categorized by three distinct evolutions: On the Ground, Curatorial, and Professional/Creative, and that each evolution has been a distinct, tactical response to evolutions of media repression and censorship in Turkey. By understanding the tactical responses of 140journos during each evolution and what prompted the large-scale organizational and tactical shifts of the group, we can more critically engage with and more thoroughly understand the constantly evolving processes of media repression and censorship in Turkey. Additionally, the trajectory of the group—going from citizen journalists in the first two evolutions to a professional ‘media’ group in its third and current evolution—indicates not only the degree and form(s) of censorship in Turkey but also the strengths, weaknesses, and potentialities of citizen journalism, more broadly.
  • Signal Transduction in Barrett’s Esophagus and Esophageal Adenocarcinoma

    Narendran, Nirushan Harushikesh (The University of Arizona., 2018)
    Barrett’s esophagus (BE) is a pre-malignant state that can proceed to the cancerous condition known as esophageal adenocarcinoma (EA). The molecular pathogenesis from the normal esophagus to BE and its progression from BE to EA is poorly understood making the diagnoses and treatment suboptimal. It is known that chronic gastro-esophageal reflux of bile acids is a trigger of BE and what initiates the epithelial metaplastic change. There has been increasing evidence in regards to the abnormal signaling seen during the development of BE that resembles to signaling pathways present during the embryological development of the esophagus. The signaling pathways seen during development of the esophagus are as follows: Bone morphogenetic protein signaling (BMP), Hedgehog signaling (HH), Wingless-Type MMTV Integration Site Family (WNT), Retinoic acid signaling pathway (RA) and Notch signaling. Importantly, in vivo and in vitro models have demonstrated that, in the presence of bile acids, these abnormal signaling pathways are induced. Although the signaling pathways mentioned are involved during the development of the esophagus from simple columnar to stratified squamous epithelium, then these same signaling pathways but in reverse should help better understand the molecular pathogenesis involved in the development of BE from stratified squamous to simple columnar.
  • Measuring the Relationship between Children’s Communicative Abilities and Executive Functions

    Clough, Lauren Taylor (The University of Arizona., 2018)
    The present study builds upon previous research to explore the relationship between children’s performance on a measure of executive function and scores of verbal ability and communication. In addition, the study examined if executive function is predictive of protective factors and behavioral concerns. Data used for this analysis were drawn from a sample of 1,350 three- to four-year-olds who had not yet entered kindergarten. Linear regression analysis suggested a relationship between child executive functions and receptive communication skills. This finding opens the door for future research to explore if the development of these two skill sets co-occurs or if one precedes the other.
  • Using Isotopes and Solute Tracers to Infer Groundwater Recharge and Flow in the Cienega Creek Watershed, SE Arizona

    Tucci, Rachel (The University of Arizona., 2018)
    The Cienega Creek watershed (CCW) of southern Arizona contains springs and wetlands (cienegas) that support several threatened and endangered species and two registered “Outstanding Arizona Waters” reaches. The lack of baseline scientific hydrologic studies in the CCW leaves important land management questions unanswered, such as how increases in urbanization, ranching, agriculture, or possible mining could impact groundwater resources? To help address these questions, this study investigates the hydrologic connection between recharge in the Santa Rita mountain system and groundwater in basin-fill aquifers, and the source water for the wetlands near Cienega Creek. Groundwater samples were collected from springs (feeding cienegas), wells, and piezometers completed in basin-fill sediments and shallow alluvial aquifers along a broad transect from the Santa Rita Mountains eastward across the basin to Cienega Creek. Samples were analyzed for major ion chemistry, stable isotopes (δ18O and δD of water, δ13C (DIC), δ34S(SO4) and δ18O(SO4)) and age tracers (3H, 14C). Results indicate springs are dominantly sourced year-round from basin groundwater, and δ18O values and sulfate to chloride ratios indicate little influence of summer monsoon floodwaters. The low sulfate concentrations and δ34S values of basin groundwater and springs are typical of local rain water values, and/or indicate small contributions of gypsum dissolution and pyrite oxidation, consistent with the lack of appreciable sulfate sources in basin sediments. Stable water isotopes in groundwater samples across the study area indicate recharge occurred from summer and winter precipitation at approximately 1700 ±200m (mountain front) and higher elevations (mountain block). Most of the groundwater samples analyzed for tritium are below modern precipitation values for the region, and 14C values are low (3.3-84.7 pMC), which indicates most recharge occurred prior to the 1950’s, even at the mountain front. The lack of recent recharge in shallow alluvial aquifers beneath the washes and near Cienega Creek suggests that groundwater throughout the basin is a relatively old resource, and future increases in groundwater capture or pumping may impact surface waters, including cienegas.
  • A Method for Analyzing Microclimate Effect of Shaded Transitional Spaces on Outdoor Human Thermal Comfort and Building Performance in a Hot Arid Region

    Horn, Patricia (The University of Arizona., 2018)
    Spaces are usually classified as either being indoors – frequently private or public outdoor spaces. Transitional spaces are an important aspect to the built environment as they have great potential to modify the environmental conditions of both indoor and outdoor spaces. They are the connecting space between the outdoor and indoors, between the natural climate and controlled climate. They can aid to building efficiency and to outdoor human thermal comfort. Transitional spaces in a hot arid region are crucial to maintaining the comfort of a user while being outside. The purpose of this investigation is to prove that shaded outdoor transitional spaces can lead to outdoor human thermal comfort and building performance. The problem being addressed is the lack of attention on shaded transitional spaces in a hot arid climate. Being located in such a harsh climatic environment it is important to look into the relationship between the building and its outdoor spaces as well as users. They are used to create a comfortable microclimate while transitioning into the building. A 9 step method will be proposed to defend the idea that shaded transitional spaces can lead to outdoor human thermal comfort and building efficiency. Methods being used are eQUEST Simulations, micro-climate data collection, and calculating outdoor human thermal comfort. The results confirmed the notion that shaded transitional spaces can lead to outdoor human thermal comfort and building performance. The comfort of the user was defined and the performance of the building was established through energy modeling simulations.
  • Parenting Styles, Conscientiousness, and Academic Performance in College Students

    Dai, Changting (The University of Arizona., 2018)
    The relationship between parenting styles and academic performance has been examined by many previous studies with students in K-12, who are school-aged participants. Only limited studies have examined this relationship in college students, the results contradicted results from studies with school-aged students and were less consistent than results with school-aged students. The present study tries to explain this inconsistency, by assessing the relationship between three types of parenting styles and GPA in college students, using conscientiousness as a mediating variable. Typological analyses and regression analyses are both included in the relationship assessment. The mediating effect of conscientiousness on the relationship between parenting style and GPA is also tested. Results indicate that three parenting styles are not predictive of GPA. Authoritative parenting style and Authoritarian parenting style are predictive of conscientiousness. Students from Authoritative families have higher conscientiousness scores than students from other families. A mediation effect was not found in the present study. These findings reinforce the statement about the advanced academic competence outcome of Authoritative parenting and suggest cumulative GPA may not be a reliable measure of achievement and could lead to inconsistent results in the studies that assess the relationship between parenting styles and academic performance in college students.
  • The Spread of Top Misinformation Articles on Twitter in 2017: Social Bot Influence and Misinformation Trends

    Schlitzer, Alyssa (The University of Arizona., 2018)
    Misinformation and how it spreads on Twitter is important for understanding the automated realm our world has developed into over time. Scholarship has focused on manipulation of information, but less research has focused on misinformation on Twitter. This thesis analyzed how social bots influenced the spread of top misinformation articles compared to non-bot users on Twitter in 2017. The study analyzed top misinformation and fact-checking article topic trends from January 1, 2017 to December 31, 2017, in the weeks leading up to and during the first year of Donald J. Trump’s presidency in the U.S. The top articles refer to those that spread the farthest on Twitter in 2017. The case study utilized descriptive statistics to analyze trends in the data and a qualitative content analysis to establish topics and subtopics of misinformation articles (N = 480). For misinformation article topics, referring to the most popular topics spread by users in 2017, “general politics” and “Trump” were the most common topic and sub-topic. For fact-checked articles, the most common article topic and subtopic were also “general politics” and “Trump.” The most common misinformation sources were online “news” outlets Breitbart and Infowars. While this doesn’t suggest that these are “fake news” websites, the findings show that these “news” outlets regularly post misleading information. Misinformation articles also spread more rapidly on Twitter than fact-checked articles did. This suggests that users spread misinformation more commonly, rather than fact-checked articles. Lastly, the “most active users” of misinformation articles on Twitter were examined to discover social bot trends. The findings show that social bots impacted the spread of misinformation articles, mostly related to topics about “Trump” and “general politics.”
  • Extracellular Matrix Induced Drug Resistance and Tumor Survival in Prostate Cancer

    Varghese, Reeba P. (The University of Arizona., 2018)
    Castration-resistant prostate cancer (CRPC) often develops in patients that fail to respond to androgen deprivation therapy (ADT). Patients with CRPC have a low survival rate and understanding its mode of drug resistance is vital in the development of therapeutic agents to treat CRPC. CRPC also demonstrates resistance to specific inhibitors such as PI3K inhibitors. The extracellular matrix has been implicated in promoting drug resistance in various cancers. Prior studies indicate that adhesion to laminin promoted drug resistance in an androgen receptor (AR) dependent manner. However, due to the copious amount of collagen found throughout the body, especially in the bone where CRPC metastases are preferentially localized, I hypothesized that collagen induces drug resistance in prostate cancer. PC-3 Puro, PC-3 AR1, PC-3 AR2, and C4-2 cells adhered to laminin or collagen were treated with PI3K inhibitors (LY294002 or PX-866). Resistance to the drug was monitored via cell death assay that examined cell viability status by trypan blue exclusion. Prostate cancer cells adhered to collagen demonstrated resistance against LY294002 and PX-866 in an AR independent manner. Immunoblot analysis indicated a collagen induced upregulation of MRP1 and MCL-1, which was blocked by AR. Treatment with S63845, an MCL-1 inhibitor, re-sensitized the cells to PX-866 and LY294002. Collectively, these results indicate collagen induces drug resistance in prostate cancer cells in an AR independent manner. However, further analysis is required to determine the precise mechanism that upregulates MCL-1 and MRP1 in collagen-induced drug resistance.
  • Contextualizing Technology: Designing Indigenous Language CALL Programs

    Alexander, Bri (The University of Arizona., 2018)
    An astounding number of global Indigenous communities work ceaselessly to reclaim and revitalize their languages after many years of suppression by colonization and dominant societies. Each community and individual learner brings myriad unique needs and desires to heritage language learning, including the need for community and cultural engagement in addition to fluency. With an increase in using technology for language learning, computer-assisted language learning (CALL) programs could be useful resources for Indigenous language learners if first adapted to support Indigenous languages. While CALL allows immense customization of programs to satisfying learner needs and linguistic diversity, BLOOM is the first and only organization to develop an Indigenous language CALL program (i.e., a program built solely for Indigenous languages and to meet the needs of Indigenous communities). Investigating BLOOM, this research analyzes a case study of the developmental process of BLOOM’s first course, including curriculum development, design decisions, engineering challenges, and the experience of partnering with the Cherokee Nation to develop a Cherokee language course. This research asserts that developers must collaborate directly with the Indigenous community during every step of the building process when developing Indigenous language CALL programs, and provides a 10-step Community-Collaborative Building Model to guide the process. The model reveals the importance of building curriculum tailored to the distinct needs of the Indigenous community, working actively and intentionally to build trust with the community, and constantly using the program to empower Indigenous communities via language learning. Overall, when producing Indigenous language CALL programs, CALL developers must adapt to meet the needs of the community, the learners, and those needs in context.
  • According to the Revolution: The Cuban Revolution in Cuban History and Cuban History in the Cuban Revolution

    Tschudy, James R. (The University of Arizona., 2005)
    This thesis combines the recent historiography on the Cuban Revolution with a theoretical approach to put forth a new mode of analysis for the ideological origin and guide of the Cuban Revolution. The role of Cuban history in the lexicon of the Cuban Revolution has been prominent, and it has provided the ideological background of the Revolution. The leadership's focus on Cuban history makes it organic in the Gramscian sense of organic versus traditional intellectuals. By analyzing the historical narrative with the assistance of the recent historiography, this thesis will show that the leadership of the 1959 Revolution had a blueprint for revolution, as well as a reference to the main obstacles to real change in Cuba: the power of the United States and the segment of the Cuban elite that willingly mortgaged sovereignty for economic and social stability in the vain of Cardoso and Falleto's analysis of dependency theory.

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