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

  • Liquid Biopsy Detection of Aberrant DNA Methylation as a Biomarker for Monitoring Reoccurrence in Trodelvy-Treated Triple-Negative Breast Cancer Patients

    Nelson, Mark A.; Stone, Isabel; Lybarger, Lonnie; Wilson, Jean (The University of Arizona., 2025)
    Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of estrogen, progesterone, and HER2 receptors, which renders it resistant to hormone-based and HER2-targeted therapies. The lack of targeted treatment options, along with a high risk of metastasis and a poor prognosis, underscores the urgent need for innovative diagnostic and monitoring strategies. Current gold-standard techniques, such as tissue biopsy and imaging, exhibit limitations in capturing tumor heterogeneity and the molecular evolution of the tumor during treatment. This study proposes a clinical trial to evaluate a six-gene liquid biopsy assay for detecting DNA methylation biomarkers in TNBC patients undergoing therapy with Trodelvy. Trodelvy, an antibody-drug conjugate that targets the TROP-2 protein, delivers SN-38, a potent chemotherapy agent, directly to cancer cells. Aim 1 focuses on validating the assay for differentiating TNBC from benign and normal tissue, while Aim 2 assesses its capacity to monitor biomarker levels and detect recurrence earlier than breast MRI. Liquid biopsy, a minimally invasive and cost-effective method for analyzing circulating blood tumor biomarkers, addresses the limitations of traditional tissue biopsies and imaging. By employing quantitative methylation-specific PCR (qMSP), this study seeks to establish liquid biopsy as a sensitive and specific tool for real-time monitoring of TNBC.
  • Targeting Cancer-Associated Fibroblasts with Recently Approved HIF2𝛼 Inhibitor, Belzutifan, in Pancreatic Ductal Adenocarcinoma

    Zavros, Yana; Castaño, Lizette Anissa; Riall, Taylor; Pond, Kelvin (The University of Arizona., 2025)
    Pancreatic ductal adenocarcinoma (PDAC) is a formidable cancer with low survival rates, influenced by a hypoxic tumor microenvironment rich in cancer-associated fibroblasts (CAFs) which contribute to tumor progression and therapeutic resistance. This paper proposes a novel approach to PDAC treatment by identifying the effects of HIF2a inhibition. Leveraging Belzutifan, an FDA-approved HIF2a inhibitor, this paper aims to assess the mechanism by which Belzutifan can effectively target myofibroblastic CAFs in the PDAC tumor stroma. By conducting a literature review and integrating findings from preliminary in vitro experiments using PDAC organoid/immune/CAF cell co-cultures, I aim to explore the changes in gene expression and signaling pathways. This will include assessing the impact on immune cell recruitment and activation through advanced molecular techniques. The findings are anticipated to advance our comprehension of PDAC pathophysiology and highlight potential therapeutic avenues, offering a promising shift in PDAC treatment strategies.
  • Beliefs of Arizona School Based Agricultural Education Teachers on Neurodivergent Students Within FFA Intracurricular Programs: A Multiple Case Study Analysis

    Rice, Amber H.; Saldaña, Samantha Christine; Molina, Quint; Torres, Robert (The University of Arizona., 2024)
    The purpose of this qualitative multi-case study was to examine the beliefs held by Arizona agriculture teachers about their role in serving neurodiverse students through intracurricular FFA programs. This study approached the research question through the lens of the neurodiversity paradigm which focuses on individuals finding acceptance and agency rather than a dysfunction to be cured. Four overarching themes emerged from the data describing Arizona agriculture teacher’s beliefs and experiences working with neurodiverse students within FFA: belonging is integral for neurodiverse students’ participation; the definition of neurodiverse student success differs from teacher to teacher; agriculture teachers believe they are more understanding of neurodiverse students; and peer learning is more impactful than traditional professional development. Recommendations for further research include expanding the number of participants to other states and programs in future analysis, comparing beliefs of general education and agriculture teachers, and exploring the self-efficacy of agriculture teachers for working with neurodiverse students. Recommendations for future practice include increased professional development and teaching training for working with neurodiverse student populations, future professional development focused on specific diagnoses within the neurodiversity umbrella, and increased effort by National FFA and state associations on inclusion for all students, including students with neurodiversity.
  • Increased Resolution in Black and White Film Digitization Utilizing a Narrow Bandpass Light Source

    Furenlid, Lars R.; Westenskow, John Patrick; Sasian, Jose M.; Kupinski, Matthew A. (The University of Arizona., 2025)
    In an effort to preserve and to provide access to their collections of black and white film negatives, many institutions (museums, libraries, archives, etc) are digitizing these collections. Several international committees were formed to define the needed image quality and created digitization guidelines with specifics for different material types to ensure that collection materials are properly documented and digitally preserved. Current practices for digitizing black and white negatives involve many different technologies, most of which incorporate broad-band "white" light sources. To assist with black and white film digitization image quality improvement efforts and standardizations, the author explores the benefits of utilizing a camera sensor without a color filter array and differing narrow-band light sources to mitigate image degradation caused by diffraction and chromatic change of focus. This thesis demonstrates that utilizing this technique enhances the optical resolution, or modulation transfer function, of the imaging setup with minimal drawbacks as is discussed in this thesis.
  • The Relevance of Direct and Indirect Photolysis Degradation of Trace Organic Compounds With 254 nm UV Light

    Saez, Eduardo; Landon, Michael; Savagatrup, Suchol; Blowers, Paul (The University of Arizona., 2024)
    Trace organic compounds, such as pharmaceuticals, hormones and disinfection by products, that persist after conventional wastewater treatment pose potential risks to the ecosystems and human health. Singlet oxygen, 1O2, is a reactive oxygen species that degrades organic compounds that are resistant to traditional wastewater treatment methods. It is not known if relevant amounts of 1O2 can be created with 254 nm UV light. Experiments using furfuryl alcohol (FFA) as a probe compound in deionized (DI) water and wastewater effluent were conducted to verify how relevant 1O2 would be for treating wastewater with 254 nm UV light. The experiments were repeated with an added photosensitizer, Perinapthenone (PN) and a singlet oxygen scavenger, sodium azide (NaN3) to compare how rapidly FFA was consumed with a guaranteed source of 1O2 and in the presence of a scavenger. These results were compared to direct photolysis experiments carried out in DI water and wastewater effluent. Unfortunately in wastewater, very low amounts of 1O2 appeared to be created. This was further verified by repeating the wastewater experiments with a variety of other TOrCs to further verify this. While most TOrCs were broken down to varying extents, Trimethoprim, notable for its extremely slow direct photolysis reaction rate, did not degrade. This suggests that very low amounts of 1O2 are created in wastewater effluent treated with 254 nm UV light.
  • Characterization of a Tunable All-Reflective Spatial Heterodyne Spectrometer

    Harris, Walter M.; Maciel, Ricardo; Harris, Walter M.; Corliss, Jason B.; Reddy, Vishnu (The University of Arizona., 2025)
    We present the characterization of a prototype Tunable All-Reflective Spatial Heterodyne Spectrometer (TARSHS), a novel extension of the already-existing and successfully flight-demonstrated All-Reflective Spatial Heterodyne Spectrometer (ARSHS) design. ARSHS is recognized for its high resolving power (R > 105), wide field of view (FOV), and unique optical design that is especially well-suited for UV-visible remote sensing of faint and extended planetary and astrophysical targets. However, ARSHS utility is limited by a fixed and narrow bandpass. TARSHS overcomes this limitation by incorporating motor-driven rotation stages into the instrument pilot mirrors, enabling rapid selection between many different bandpass centers across a broad spectral range. This tunability significantly enhances the instrument’s versatility and potential science return per flight without sacrificing the high R and FOV that are characteristic of base ARSHS design. The TARSHS prototype reported below, assembled primarily with commercial-grade components, demonstrated a resolving power of R = 30,000 across an operable range of 400 – 700 nm. Stable, reliable tuning and minimal degradation across its tunable range were found, supporting its readiness for higher technology readiness levels (TRL). This study outlines the optical configuration, operational mechanics, and prototype results, establishing TARSHS as a robust, cost-effective tool for space-based spectroscopy. Future efforts should focus on miniaturization and environmental validation for deployment on robotic missions.
  • Design and Evaluation of a Retroreflector System for Primary Mirror Health Diagnostics in ITER Optical Systems

    Sasian, José M.; Scott, Justin; Norwood, Robert A.; Kim, Daewook (The University of Arizona., 2025)
    The integrity of optical components in the ITER tokamak is critical for accurate plasma diagnostics, yet prolonged exposure to high-energy plasma environments leads to contamination and degradation of reflective surfaces. This thesis presents the design, implementation, and validation of an in-situ health monitoring system for the primary diagnostic mirror, utilizing a 1D retroreflector mounted on the shutter to assess its condition. The proposed system enables back-illumination from the image plane, allowing for the analysis of mirror reflectivity, contamination levels, and overall surface quality.Through extensive optical modeling in Zemax and FRED, this work demonstrates that the retroreflector provides a viable and effective method for monitoring mirror health by analyzing the return signal from the reflector. The study establishes a quantitative framework for evaluating mirror performance, showing that quality and contamination can be directly correlated with scattering effects. By leveraging Bidirectional Scattering Distribution Function (BSDF) models and Total Integrated Scatter (TIS) analysis, this research quantifies how mirror degradation leads to increased optical noise, signal attenuation, and cross-talk between image channels. Additionally, this thesis identifies ghost imaging and stray light as significant sources of optical contamination, with simulations revealing that up to 69% of power can be lost due to unintended reflections. These findings emphasize the need for careful system design, optimized anti-reflective coatings, and advanced scattering control strategies to maintain high signal integrity. The results further demonstrate that the retroreflector method is highly sensitive to scattering variations, amplifying the observed scattering effects and enabling early detection of mirror degradation. By comparing beam-based and retroreflector-based measurements, this study confirms that scattering effects can be quantified and used as a diagnostic metric for assessing long-term mirror health. Ultimately, this work proves that a retroreflector-based system provides a practical, scalable, and non-invasive solution for monitoring primary mirror health in high-exposure plasma environments. The findings contribute to the development of an optimized calibration and monitoring strategy, ensuring that IT-ER’s optical diagnostics maintain long-term accuracy and reliability despite the challenges posed by plasma-induced contamination and degradation.
  • Mean Flow Characterization of Swept Shock/Turbulent Boundary Layer Interactions Induced by an Impinging Oblique Shock

    Threadgill, James; Little, Jesse; Groves, Jesse Ronald; Craig, Alex (The University of Arizona., 2024)
    Experiments have been conducted in a blowdown wind tunnel at Mach 2.1 and Mach 3.0 to study swept shock boundary layer interactions (SBLIs) generated by impinging, oblique shocks on a fully turbulent boundary layer. The overall goal of this work is to determine the effect of increasing the aspect ratio of the SBLI by comparing results to similar experiments conducted in a smaller wind tunnel. Shock sweep angles of 20 and 40 degree are tested at each Mach number. The quasi-infinite region is increased by increasing the aspect ratio of the shock generator from 2.33 in previous studies to 2.75 in the current study. To isolate the effect of sweep, a fixed inviscid pressure rise normal to the sweep angle of Cpn is used for each case. The mean flow topology is studied using three methods: infrared thermography, mean pressure measurements, and oil flow visualization. Mean flow results from each of the three techniques show good agreement and are able to identify salient features of the SBLI. The Stanton number distribution from infrared thermography accurately provides the location of the initial pressure rise and separation via a local minima and maxima in the Stanton number distribution. Mean pressure results also validate the locations of the initial pressure rise and separation locations determined from infrared thermography results. Oil flow shows the local skin friction direction on the SBLI surface and offers the most conclusive separation and reattachment locations, but also allows for the visualization of the initial pressure rise. The initial pressure rise and separation locations for all three methods align well, validating the use of infrared thermography to identify these salient features of the SBLI. A local maxima of the Stanton number distribution is seen in both separated and attached SBLIs. Therefore, heat flux data can be used to aid in determining the location of the separation for the SBLI, but does not offer conclusive results for whether the flow has separated or remains attached. Further, the Stanton number distribution is not sufficient in determining a precise location of reattachment if the flow has separated. Oil flow visualization offers the most conclusive results when determining separation and reattachment. Previous results from a smaller aspect ratio interaction show that separation exhibits conical similarity for 20 degree sweep in Mach 2.3 flow. However, oil flow visualization at Mach 2.1 for the larger aspect ratio interaction investigated here exhibits cylindrical behavior. This suggests that the SBLI aspect ratio influences the mean flow topology in that lower aspect ratios promote conical similarity. Comparison of the 40 degree sweep cases for the two different aspect ratio tests show similar structures, but Mach 3.0 results require further analysis since oil flow offers the most accurate reattachment location but was unable to be obtained for these tests.
  • Progression

    Leslie, Kelly; Zimmermann, Karen; Ruiz, Deborah; McMahon, Ellen; Gubner, Jennie; See, Lydia (The University of Arizona., 2025)
    What began as research to understand dementia and cognitive decline became something much more personal: a way to process my own grief while navigating the complexities of my mother’s illness. This thesis, Progression, reflects these intertwined journeys. Using the stages of grief as a framework—shock, denial, anger, bargaining, depression, processing, and acceptance—this work explores the parallels between my mother’s cognitive decline and my emotional reckoning. Through a series of interactive prints, I invite viewers to engage not only with my story but with their own. This project is a space for reflection and connection, where personal experiences with loss, caregiving, and change can resonate universally.
  • Characterizing Hydroponic Dwarf Tomato Growth in Microbially Inoculated Lunar Regolith Simulant

    Hooks, Triston; Gelman, Adam William; Kacira, Murat; Hurwitz, Bonnie (The University of Arizona., 2025)
    Plant-microorganism interactions in crop production represent a critical and under-researched aspect of controlled environment agriculture (CEA) and bioregenerative life support systems (BLSS). Beneficial microorganisms have been shown to enhance plant resistance to pathogens, response to abiotic stress, and ability to uptake nutrients through the roots. The objectives of the current research were: 1) to demonstrate hydroponic crop production with lunar regolith for in-situ resource utilization (ISRU) within BLSS; and 2) to investigate the utility of microorganisms in hydroponic and BLSS via inoculation of lunar regolith simulant in a Bato bucket system. Dwarf tomatoes (c.v. Red Robin) were grown in coco coir-amended lunar regolith simulant (LRS) over 6 weeks, excluding germination and emergence stages, in a 2-factor factorial design (substrate x inoculation). Data was analyzed using SAS procedure GLM (general linear model) with least squares means and Tukey’s Honestly Significant Difference (HSD). Dwarf tomato ripe fruit yield and total fruit yield from plants grown in LRS was not significantly different from those grown in the control substrate (perlite), indicating that lunar regolith might be viable for ISRU within hydroponic crop production in BLSS. However, dwarf tomato shoot biomass (both fresh and dry weight) was significantly lower in LRS compared to perlite, indicating a negative impact to vegetative plant growth in lunar regolith that requires further investigation. Interestingly, the Brix (soluble sugar content) of ripe fruit was not significantly different between treatment groups, indicating a lack of plant salinity stress from the LRS which was another positive result. Finally, microbial inoculation showed no significant impact, either positive or negative, on any response variable measured and no significant interactions were found. Numerical patterns indicate that extending the duration of this type of study may reveal positive effects of microbial inoculation on plant biomass in both LRS and perlite, warranting further investigation.
  • Population Ecology and Conservation Translocation of the Narrow-Headed Gartersnake in Central Arizona

    Bauder, Javan M.; Roderick, Travis; Steidl, Robert J.; Ryan, Mason J. (The University of Arizona., 2025)
    The narrow-headed gartersnake (Thamnophis rufipunctatus) is a federally threatened species endemic to the Mogollon Rim in central Arizona and western New Mexico. This species has declined its range primarily due to habitat loss, degradation and invasive species. Additional information on this species’ ecology, particularly empirical estimates of movement and demographic parameters, are particularly important for the management and conservation of this species. We conducted a three-year mark-recapture study of narrow-headed gartersnakes in Canyon Creek in central Arizona. In chapter 1, we compared capture rates, individual growth rates, movement, and apparent survival between narrow-headed gartersnakes and a syntopic, non-imperiled species of gartersnake, the western terrestrial gartersnake (Thamnophis elegans). While we captured more western terrestrial gartersnakes during our study, we did not find marked differences between these two species in the metrics we examined. We also documented the successful application of passive PIT tag arrays for monitoring PIT-tagged gartersnakes. In chapter 2, we evaluated the post-release growth, movement, and apparent survival zoo-born narrow-headed gartersnakes from the Arizona Center for Nature Conservation/Phoenix Zoo’s breeding program and compared these metrics to those of wild narrow-headed gartersnakes. We released four different groups of zoo-born individuals representing two cohorts (young-of-year and holdover). We documented multiple instances of survival across one and two winters post-release by zoo-born individuals from The Arizona Center for Nature Conservation/Phoenix Zoo. We did not find marked differences between zoo-born and wild individuals although holdover individuals tended to have the greatest movement distances and lowest apparent survival. Our results can provide guidelines for the future use of conservation translocations for narrow-headed gartersnake recovery.
  • Modeling Growth of Chlorella sorokiniana by Changing CO2 Nutrient Concentration

    Ogden, Kimberly; Pajouyan, Armeen Robert; Saez, Eduardo; Flouda, Paraskevi (The University of Arizona., 2025)
    Algae research has gained significant attention due to its potential in carbon capture and biofuel production. Understanding the role of CO2 in algae growth is critical to optimize these processes. This study investigates the impact of CO2 on the growth of Chlorella sorokiniana under various experimental conditions. All experiments were conducted at a temperature of 35°C, a light intensity of 234 µmol m-2 s-1, and a 12-hour light window. For the main set of experiments, CO2 flow percentage was changed from 5% to only air flow to see the effect on growth rate. The results showed that excess CO2 doesn’t significantly affect growth, however when it is no longer in excess as concentration drops the growth rate decreases. A one-parameter model was applied to the data, providing values that accurately represent the data. In another experiment, the effects of CO2 flow being on always was compared with CO2 flow only being on during the light phase. The results supported the hypothesis that CO2 flow at night has a negligible impact on growth. In the final experiment, the flowrate of air was lowered while CO2 flow remained the same across both runs. This would be so that one run would have a total flow of 2 LPM and the other a total flow of 1 LMP. This is because although air flow is needed for oxygen content, excess can strip the CO2 from the reactor reducing efficiency. The results confirmed this as the 1 LPM experiment had a lower pH, meaning that there was more dissolved CO2 in solution.
  • Mexican Migrants Return South: Transborder Testimonials of Resilience and Adaptation in Mexico City

    Vásquez-León, Marcela; Carrión, Luis; Retis, Jessica; Bricca, Jacob (The University of Arizona., 2024)
    Migration from Mexico to the United States is a prominent topic in the U.S. and is the foundation for many political agendas and policy debates. However, return migration has received comparatively little attention in academia or policy initiatives. This thesis/documentary film examines the lived experiences of young adult Mexican return migrants in Mexico City, those with extensive histories in the United States who have been forced to return due to deportation or untenable living conditions as undocumented individuals in the US. Through an ethnographic research project, consisting primarily of a testimonial-based documentary film depicting the lives of return migrants, this study investigates transnational identity, liminality, structural violence, and the roles of community and resilience in adaptation to a new and unfamiliar country and culture. This project uses qualitative data from interviews, field observations, and video documentation to present a nuanced and candid view of how return migrants are forced to create a life in an unfamiliar place while at the same time giving rise to an emerging bicultural and transnational demographic in Mexico City.
  • Polychlorinated Biphenyl Contamination of Freshwater Fish From Military Sites in the Aleutian and Bering Sea Islands Region

    von Hippel, Frank; Demitrack, Zoe; von Hippel, Frank; Reynolds, Kelly; Yang, Yu (The University of Arizona., 2024)
    The biomagnification of persistent organic pollutants (POPs) in the arctic foodweb is a key concern of the Aleutian and Bering Sea Islands (ABSI) Initiative, a partnership dedicated to tackling the “unprecedented environmental change impacting the lives, lands, and waters” of the ABSI region. To address this concern, this thesis expands upon the current but limited knowledge of regional pollution of a signature POP, polychlorinated biphenyls (PCBs). PCBs are considered “probable human carcinogens” by the US Environmental Protection Agency (EPA)2. They are also associated with adverse neurological, reproductive, and immune system effects in animals. Through the process of global distillation, the Arctic serves as a hemispheric sink for PCBs used and manufactured at lower latitudes. Once in the Arctic, PCBs bioaccumulate and biomagnify in the lipid-rich arctic foodweb. Due to both global distillation and local sources of pollution such as military sites, arctic Indigenous people practicing a subsistence lifestyle are exposed to high levels of PCBs. Despite the ecological, cultural, and economic significance of the ABSI region, as well as regional reliance on a subsistence diet, little information exists on current and long-term regional trends in PCB contamination of important biota. The ABSI region was militarized during World War II and the Cold War. As a result of militarization, 51 formerly used defense (FUD) sites are scattered across 32 islands. FUD sites are known hotspots for POPs including PCBs, but the majority have not seen any remediation. The United Nation’s 2020 Arctic Monitoring and Assessment Programme report suggests that while atmospheric deposition of PCBs in arctic environments is decreasing, re-emissions from local sources, such as military sites, are becoming increasingly important. Little is known about the importance of FUD sites as sources of PCB contamination in the ABSI region. Identifying trends in long-range PCB contamination, as well as the role FUD sites play in local contamination, is vital to protecting the unique ecosystems and subsistence practices of the region. As such, the aims of this thesis are to: 1) provide a background and historical information on the Arctic and the ABSI region as it relates to PCB pollution; and 2) analyze PCB contamination in two freshwater fish species collected military and non-military sites throughout the ABSI region. Future work will include an examination of PCB contamination of fish and shellfish on Unalaska Island and a quantitative risk assessment based on contaminant concentrations in fish.
  • Bacterial Modulation of the Epithelial Barrier in Crohn's Disease

    Vercelli, Donata; Duhon, Dillon; Lybarger, Lonnie; White, Katie (The University of Arizona., 2024)
    Crohn’s Disease is a complex, multifactorial disorder induced by chronic, disproportionate inflammatory responses to the bacteria that reside in the digestive tract. One mechanism by which this inflammatory response is induced is a dysfunctional epithelial barrier, in which bacteria are exposed to the immune system in an unregulated fashion that leads to inflammatory-mediated bowel damage. As discussed in this thesis, the epithelial barrier is regulated by a number of different cell types, receptors, as well as the products of microbial metabolism. Microbial metabolites, such as short-chain fatty acids, indole derivatives, and secondary bile acids, have recently been elucidated to have significant physiological effects on the epithelial barrier. Thus, microbial metabolites may have useful implications as Crohn’s Disease biomarkers or as therapeutic agents in disease treatment and remediation.
  • A Constitutive Model for Simulating Weak Rock Mass Behavior

    Momayez, Moe; Azadi, Ava; Kemeny, John; Waqas, Muhammed (The University of Arizona., 2024)
    This thesis develops an advanced constitutive model for simulating the behavior of weak rock masses, which are often characterized by low strength and high deformability. Addressing the complexities inherent in geological formations, the model integrates key factors such as stress anisotropy, pore pressure, deviatoric stress, and thermal effects. Traditional models often fail to capture the nonlinear and probabilistic responses of weak rock masses under varied stress conditions. This study overcomes these limitations by employing Monte Carlo simulations combined with Weibull distributions to better reflect the variability and heterogeneity of geological properties. The model's validity is confirmed through a comprehensive comparison of simulated data with experimental results, employing statistical methods such as the Kolmogorov-Smirnov test and visual analysis techniques. The findings demonstrate that the proposed model accurately predicts the mechanical behavior of different rock types, such as Claystone, Mudstone, Sandstone, Shale, and Siltstone, under diverse loading scenarios. Practical applications of this model are highlighted in fields like mining engineering, geothermal energy, and oil reservoir management, where predicting rock mass stability and behavior is critical. While the model shows significant advancements over existing methods, it also acknowledges limitations and suggests areas for future research, such as incorporating long-term environmental factors and expanding empirical data calibration.
  • A Nation Trapped in Time

    Jens, Benjamin; Kelley, Catricia Galyn; Gordienko, Anastasia; Leafgren, John (The University of Arizona., 2025)
    This thesis explores the complex interplay of time and national identity in Soviet and post-Soviet Russia through the metaphor of a house. Structured around the elements of a house—floor, walls, windows, doors, and roof—this paper examines how time operates as the framework for constructing and containing identity. Drawing on literary and cinematic works, the study reveals how the floor symbolizes the past, the walls represent the present, the windows and doors signify transitions and possibilities for the future, and the roof encapsulates stagnation and unresolved trauma. By analyzing Yevgeny Zamyatin's We, Andrei Tarkovsky's Solaris, Natalya Baranskaya's A Week Like Any Other, and Svetlana Alexievich's Chernobyl Prayer and Secondhand Time, the thesis investigates the tension between historical memory and cultural evolution. Zamyatin’s We critiques the manipulation of historical foundations under totalitarian control, while Tarkovsky’s Solaris portrays the haunting of the present by unresolved pasts. Baranskaya’s works highlight the constrained opportunities for societal transition, particularly for women. Alexievich’s oral histories delve into the weight of collective trauma, depicting the roof of the house as a site of stagnation, where unresolved crises impede forward movement. The metaphor of the house of time offers a fresh perspective on Russian identity, emphasizing the necessity of confronting historical ghosts and engaging with cultural diversity to foster a more dynamic and inclusive future. This study demonstrates how the intersections of time, memory, and identity shape a nation’s struggle to navigate its past while envisioning new possibilities for growth and transformation.
  • Age, Sex, and APOE4: Insights into Metabolic Changes in a Novel Mouse Model of Late-Onset Alzheimer’s Disease

    Brintons, Roberta D.; Delatorre, Nicole; Rodgers, Kathleen; Wang, Tian (The University of Arizona., 2024)
    Late-onset Alzheimer’s Disease (LOAD) is a progressive and irreversible neurodegenerative disease characterized by memory loss, cognitive decline, and brain atrophy. Age, chromosomal sex, and apolipoprotein E (APOE) genotype are well-documented risk factors for the development of AD, each having a systemic impact and significant implications for disease progression. Understanding the interactions among these risk factors is essential to elucidate the underlying mechanisms of disease development. Prior to clinical onset, LOAD is preceded by a decades-long prodromal phase. Previous studies have suggested that metabolic dysregulation during midlife aligns with this prodromal period. We hypothesize that age, APOE genotype, and chromosomal sex interact to drive AD risk through mechanisms that extend beyond traditional amyloid and tau pathology, involving systemic metabolic dysregulation. Specifically, we propose that these factors shape sex- and genotype-specific metabolic profiles, with female APOE4 carriers exhibiting metabolic dysregulation, and earlier than their male counterparts. To test this hypothesis, we utilized a novel mouse model combining humanized amyloid precursor protein (hAPP) and apolipoprotein E (hAPOE) to investigate sex- and genotype effects on metabolic profiles, evaluating energy metabolism and circulating lipids. Our findings revealed significant sex-driven differences, with females demonstrating earlier metabolic changes. Female hAPP+hAPOE4 mice exhibited disrupted glucose and lipid metabolism, and lower circulating cholesterol. This study provides a novel investigation into the effects of age, sex, and APOE genotype in a LOAD risk mouse model. By utilizing a preclinical model expressing humanized APOE and APP without dominant, disease-causing mutations, we examined the nuanced effects of APOE4 metabolic regulation across aging in a potentially more translational context. Furthermore, this work emphasizes sex-driven metabolic changes, providing additional insight into the increased vulnerability to LOAD in females.
  • Automated Analysis of Scattering-based Light Sheet Microscopy Images of Anal Squamous Intraepithelial Lesions

    Kang, Dongkyun; Kim, Yong Jun; Sawyer, Travis; Subbian, Vignesh (The University of Arizona., 2024)
    Anal cancer presents diagnostic challenges, particularly in identifying high-grade squamous intraepithelial lesions (HSIL), with its increasing incidence and mortality rates. Current diagnosis methods, including cytology, biopsy, and high resolution anoscopy (HRA), provide important diagnostic information. However, cytology is often limited by suboptimal sensitivity and specificity, while high resolution anoscopy-guided biopsy is limited by its long processing times due to unnecessary biopsies and staining requirements. Scattering-based light sheet microscopy (sLSM) can offer an alternative approach by utilizing intrinsic tissue scattering properties to visualize morphologic features without the need for additional labeling or staining.In this study, we developed and evaluated an automated algorithm for analyzing 187 sLSM images obtained from 80 anal biopsies. The method employed a row-by-row binarization technique for nuclear segmentation, achieving high precision (0.97) and recall (0.91). Seven nuclear features, including nuclear intensity, intensity slope as a function of depth, nuclear-to-nuclear distance, nuclear-to-cytoplasm ratio, cell density, nuclear area, and proportion of pixels corresponding to nuclei were extracted and statistically analyzed. Among the seven features, six showed statistically significant differences between HSIL and non-HSIL (non-dysplastic or low-grade squamous intraepithelial lesion, LSIL). A linear support vector machine (SVM) was trained and tested using five-fold cross validation on these features. The classifier achieved a sensitivity of 90%, specificity of 70%, and area under the curve (AUC) of 0.89 for per-image diagnosis, and sensitivity of 90%, specificity of 80%, and area under the curve (AUC) of 0.93 for per-biopsy diagnosis.
  • Changes in Photosynthetic Net CO2 Assimilation Rates on Theobroma cacao L. From In Situ Artificial Leaf Warming: A Study in the Biosphere 2 Tropical Rainforest

    Hurwitz, Bonnie L.; van Haren, Joost; Blue, Bryan P.; Giacomelli, Gene A. (The University of Arizona., 2024)
    A 33-week long in situ leaf warming experiment was performed to determine the change in the rate of photosynthetic net CO2 assimilation rates (A) in the tropical understory species, Theobroma cacao L. (cacao) in the controlled environment of the tropical rainforest biome of Biosphere 2 (B2), Oracle, Arizona, USA. A sustained multi-week in situ leaf level temperature increase of 3 °C was performed to understand rate changes in A, stomatal conductance (gsw), evapotranspiration (E), and vapor pressure deficit at leaf temperature (VPDleaf). Three warming experiments were performed on two mature, fruit producing cacao trees from 17 November 2023 to 8 May 2024 . One leaf was heated using a custom designed leaf heating device where it was continuously heated to 3 °C above ambient leaf temperature; another had the same heating structure installed but not heated, and an ambient leaf used as a control. Sustained leaf warming at 3 °C caused a decrease in photosynthetic net assimilation rates (A), evapotranspiration (E), and stomatal conductance (gsw), and an increase in vapor pressure deficit at leaf temperature (VPDLeaf). Together, these indicated that heating the leaf caused a net photosynthetic decline, supported by the decreased gas exchange that would limit CO2 uptake, reduce A rates, and increase VPDleaf due to reduced E. The presence of the heating apparatus in the Unheated treatment showed mixed results, and no statistical conclusions could be drawn about its effect on the response of A and results did not significantly vary from the control leaf.

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