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  OPTOMECHANICAL DESIGN SOLUTIONS FOR FIREBALL-2 SPECTROGRAPH ALIGNMENT VERIFICATION AND CONTROLLED-ENVIRONMENT TRANSPORT OF ASPERA UV FLIGHT OPTICS

  Chung, Haeun; Uppnor, Sumedha; Chalifoux, Brandon D.; Choi, Heejoo (The University of Arizona., 2025)

  Optomechanical design integrates the precision of optical science with the practicality of mechanical realization, ensuring that theoretical designs perform reliably under real-world conditions. It governs alignment, stability, and environmental resilience, factors that directly define the success of complex instruments used in space missions and laboratory research. This thesis presents two representative optomechanical systems developed for ultraviolet (UV) astronomical instrumentation. The first, the FIREBall-2 (FB-2) telescope simulator, is a portable analog of the balloon-borne UV telescope. Roughly ten times smaller than the 1-m primary and 1.2-m siderostat mirror system, it reproduces their optical behavior and provides arcsecond-level tip-tilt control for alignment verification of the UV spectrograph. The system’s optomechanical layout, degrees of freedom, and alignment campaigns at the University of Arizona and the California Institute of Technology are discussed. The second project concerns nitrogen-purged shipping containers for the Aspera SmallSat mission UV coated flight optics. To protect hygroscopic Al+eLiF coatings prior to MgF$_2$ encapsulation, custom containers and preparation procedures were developed to maintain relative humidity below 5\%. The design limited reflectance degradation to less than 1.1\% after encapsulation, as observed on calibration coupons, validating the controlled-environment approach. Together, these projects demonstrate how carefully engineered optomechanical solutions, are essential to achieving and preserving optical performance throughout the project lifecycle.
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  ABSOLUTE RADIOMETRIC CALIBRATION SENSITIVITY ANALYSIS OF VANTOR’S SURFACE REFLECTANCE PRODUCT

  Czapla-Myers, Jeffrey S.; Driggers, Ronald; Ochoa, Tina; Kuester, Michele A. (The University of Arizona., 2026)

  This thesis evaluates the accuracy and sensitivity of Vantor’s Atmospheric COMPensation (ACOMP) surface reflectance product, a key component in enabling consistent, analysis-ready Earth observation data. Vantor performs absolute radiometric calibration using the vicarious method at its site at Colorado Air and Space Port (CASP) in Watkins, CO over specialized reflectance targets. The radiometric performance of ACOMP-derived surface reflectance is assessed using in-situ reflectance measurements collected at a farmed vegetative field at CASP, along with RadCalNet (RadCalNet) observations of the stable natural target Railroad Valley (RVUS). The analysis quantifies how well these products reproduce ground-measured reflectance under varying atmospheric and viewing conditions.A central focus of this work is the influence of absolute radiometric calibration coefficients on surface reflectance outputs. To characterize this relationship, a Monte Carlo sensitivity analysis was conducted that systematically perturbs calibration coefficients across a range of plausible uncertainty thresholds. This approach isolates the extent to which calibration uncertainty propagates into downstream reflectance products and identifies spectral regions and product types most affected by radiometric variability. The results provide an empirical basis for understanding the robustness of ACOMP’s atmospheric correction framework and highlight the critical role of accurate vicarious calibration in ensuring radiometric fidelity. These findings support ongoing efforts to refine calibration strategies and improve the consistency of Vantor’s reflectance products across sensors and acquisition conditions.
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  Evaluating Catch Bench Effectiveness and Rockfall Retention Strategies Using Field-Calibrated Rockfall Models

  Luxbacher, Kray K.; Restrepo Marulanda, Jose Andres; Hyun Kim, Bo B.; Warren, Sean S.; Ryan, Thomas T.; Adewuyi, Sefiu S. (The University of Arizona., 2025)

  Rockfall hazards represent one of the most persistent safety concerns in open-pit mining, threatening personnel, equipment, and production efficiency. This thesis evaluates the effectiveness of catch benches and flexible barrier systems using field-calibrated numerical modeling. The research integrates experimental rockfall data collected at Bald Mountain Mine, Nevada, through the National Institute for Occupational Safety and Health (NIOSH) project Highwall Safety: Rockfall Catchment Design and Slope Performance Monitoring. The first study focuses on the calibration of a two-dimensional rockfall model in RocFall2 by matching field test results from controlled drop experiments, establishing restitution and friction parameters representative of actual slope conditions. Beyond evaluating the performance of the first catch bench, this study also examines the proportion of blocks retained on the subsequent benches, providing a broader understanding of cumulative catch efficiency across the slope. The calibrated model determined that 90 % of 6-inch synthetic blocks were retained within 10.9 m of the bench toe, defining a benchmark for performance evaluation. This framework was then applied to assess how variations in bench geometry, barrier height, and barrier placement affect rockfall containment. Twenty-four simulations combining different bench and barrier configurations revealed that specific bench–barrier combinations can maintain containment levels close to the 90 % benchmark, even under geometrically constrained conditions. The findings demonstrate that barriers can compensate for reduced bench width, providing a practical approach for achieving safety goals while supporting steeper slope designs and improved ore recovery. Overall, this research highlights the value of field calibration in enhancing model reliability and bridging empirical design criteria with numerical analysis. The results contribute to the development of performance-based methodologies for rockfall hazard mitigation, supporting safer and more efficient slope-design practices in modern open-pit mining.
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  The Canon of Contemporary Native American Women Artists: An Examination of Exhibition History and Social Contexts

  Ivey, Paul E.; Charpentier, Phoebe; Widdifield, Stacie; Saracino, Jennifer (The University of Arizona., 2026)

  The canon of contemporary Native American women artists formed differently than the traditional, Western art historical canon. This canon has been deliberately constructed through strategic interventions by artists, curators, and scholars—many of them Native women themselves—who recognized that existing art historical frameworks were fundamentally inadequate for understanding their work. Unlike the Western canon, which developed over centuries through gradual critical consensus, the canon of contemporary Native women artists can be traced through its exhibition history which reveals curatorial practices/interventions that broke from the art historical mechanisms traditionally utilized in fine arts contexts. Drawing on three interconnected theoretical frameworks developed by Indigenous scholars—visual sovereignty (Jolene Rickard), Indigenous feminisms (Nancy Marie Mithlo), and place-thought (Vanessa Watts)—this thesis traces the history of five landmark exhibitions over a 34 year period, from 1985-2019. Through comparative analysis of these exhibitions—Women of Sweetgrass, Cedar, and Sage (1985), Watchful Eyes (1994), Legacies (1995), Nourishing Hearts, Creative Hands (1998), and Hearts of Our People (2019)—this thesis identifies eight paradigmatic artists whose repeated inclusion across exhibitions constitutes canonical recognition: Kay WalkingStick, Jaune Quick-to-See Smith, Carm Little Turtle, Ramona Sakiestewa, Emmi Whitehorse, Jolene Rickard, Roxanne Swentzell, and Shelley Niro. Organized thematically around body and identity, land and place, memory and materials, and curation and exhibition space, this analysis demonstrates that the canon these artists represent differs fundamentally from its Western counterpart—constituting not a hierarchy of individual genius but a network of relational practices grounded in Indigenous knowledge systems and the ongoing assertion of cultural sovereignty.
• The Relationship of Instrument and Human Assessment of USDA Marbling Score to Chemical Intramuscular Fat and Cooked Steak Palatability

  Wulf, Duane M.; Garcia, Lucila de la Caridad; Diaz, Duarte; Merrell, Douglas S. (The University of Arizona., 2025)

  This study evaluated the relationships among human marbling scores, camera marbling scores, chemically determined intramuscular fat, and sensory attributes of cooked beef. Carcasses (n = 213) representing a broad range of marbling levels were evaluated by USDA graders and a VBG2000 camera system. Chemical intramuscular fat was quantified using Soxhlet extraction, and trained sensory panelists assessed tenderness, juiciness, and beef flavor intensity. Both human and camera marbling scores were strongly correlated with intramuscular fat concentration (R² = 0.68–0.90), demonstrating that visual and image-based evaluations accurately predict lipid content within the longissimus muscle. However, intramuscular fat and marbling scores were only weakly associated with sensory attributes (R² ≤ 0.13). Although greater intramuscular fat corresponded with marginal increases in tenderness, juiciness, and flavor intensity, these relationships accounted for little of the overall variation in eating quality. Greater intramuscular fat and higher marbling scores were more closely associated with juiciness and beef flavor intensity than with tenderness measurements. These findings confirm that marbling—whether assessed visually or instrumentally—serves as a reliable indicator of intramuscular lipid deposition but a limited predictor of palatability. Integration of objective camera grading with additional biochemical and structural metrics may enhance the precision of beef quality evaluation and prediction of consumer satisfaction.
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  Computational Approach to Wingtip Jets Effect on Flow Entrainment and Aerodynamics

  Hanquist, Kyle M.; Mozzone, Luciano Mario; Shkarayev, Sergey V.; Hacker, Wayne L. (The University of Arizona., 2026)

  This work presents computation analysis of the dynamics of a wing with blowing jets at the wingtip. Specifically, the project uses a NACA 0012 wing model, with internal flow chambers and blowing jet slits at the wingtip. With this wing setup, the project was a sensitivity investigation to the impact of different Computational Fluid Dynamic setup conditions and meshes across a range of different freestream velocities and jet pressures. This computational study complements an experimental investigation of the same NACA 0012 with wingtip jets. A comparison of the experimental and computational results are discussed, with a focus on the similarities and differences. The study found the impact of blowing jets, either from the top or bottom jet, had positive effects to coefficient of lift by artificially extending out the wings aspect ratio, and interrupting the formation of wingtip vortices. It was also observed that the inclusion of jets has a more significant impact at lower freestream velocities, where the difference between jet pressure and freestream velocity is larger. Lastly, these results can be correlated back to the experimental data, giving credence to the benefits of wingtip jets. The results will discuss these findings in more detail, assessing the impact of freestream velocity, jet velocity, solver, turbulence model, mesh, and whether the top, bottom, or no jet was active.
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  A New Algorithm for the Open-Pit Production Scheduling Optimization Problem

  Anani, Angelina; Leiterman, Isaac; Anani, Angelina; Risso, Nathalie; Momayez, Moe (The University of Arizona., 2026)

  Open-pit mine production scheduling optimization is pivotal in ensuring a mine operates profitably. However, achieving optimality in a production schedule is often intractable. This is due to two factors. The first is the NP-hard classification of the problem, meaning there are no known efficient algorithms for finding exact solutions. The second is the large scale of realistic block models, which can lead to millions of variables and constraints with which the optimization problem is subject to. Therefore, it is common practice to rely on heuristics and block aggregation methods for generating operationally feasible solutions. However, these solutions are not guaranteed to be optimal and are more often than not far from optimality. This research presents an alternative for gathering optimal and near-optimal solutions through a novel relaxation-repair algorithm. Precedence constraints, which make up the majority of the constraints present in an open-pit production scheduling optimization problem, represent open-pit slope stability. However, due to how they are enforced, each is implied by the other precedence constraints when the full precedence set is considered. Because of this, the constraint matrix size is inflated, and the solver’s performance decreases. The goal of this research is to showcase a method for applying only subsets of precedence constraints instead of the full precedence set. The initial relaxation phase of the algorithm solves, to optimality, the problem with only a subset of the precedence constraints. However, the relaxation is not assured to be operationally feasible with respect to the full precedence set. Therefore, a final repair phase is conducted to recover feasibility. Some instances were able to achieve optimality without requiring a repair step. Through testing, this algorithm has shown that it can outperform a traditional precedence formulation in several instances. In some cases, the algorithm generated optimal and near-optimal (<0.15% optimality gap) production schedules in under a quarter of the time.
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  Zernike Sensitivty Based Machine Learning Aided Optical Alignment

  Kim, Daewook; May, Jeffrey; Sasian, Jose; Choi, Heejoo (The University of Arizona., 2026)

  The science of telescope alignment is a puzzle to solve what compensator and degree(s) of freedom (DOF) to use and how far it needs to move to achieve the goal of minimizing the total wavefront error. How far the compensator needs to move is determined by an optimizer such as Zernike sensitivity analysis, which solves a system of linear equations to determine an alignment solution1. The alignment solution, as determined by the optimizer, is only as good as the compensator selection allows it to be. This represents a classic case of bad in, bad out. Traditionally, the choice of compensator comes from an understanding of the Zernike sensitivities and selecting the compensator that is most sensitive to the Zernike term that is to be minimized. This approach alone can be challenging to determine the absolute best set of compensators to use to minimize the wavefront error while also minimizing the number of alignment iterations and the number of compensators used. Implementing a trained machine learning neural network algorithm to aid in compensator selection will result in a reduction in alignment iterations to achieve a minimized solution. Any of three training methodologies can be used in the aid of optical alignment, the three methods are all based on the design specific Zernike sensitivities. The methods are Field Variation, Local Sensitivity, and Global Sensitivity. All methods, without human involvement, will align to a global minimum in less alignment iterations than a trained human. With a trained human who understands Zernike sensitivities and how they can be used to select compensators, all three methods will result in a reduction in compensators use to achieve the global minimum in less alignment iterations.
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  Evaluation of Spatial Light Modulator for High Contrast Imaging

  Guyon, Olivier; Bragg, Jennifer; Douglas, Ewan S.; Males, Jared R. (The University of Arizona., 2025)

  High Contrast Imaging (HCI) systems are optimized to image faint objects located near bright point sources. This is essential to exoplanet imaging and the search for biological activity by spectroscopic characterization of exoplanet atmospheres. HCI systems for future large space telescopes capable of imaging about a dozen habitable exoplanets will require correction of >10,000 wavefront modes, but conventional Deformable Mirrors (DMs) only provide about 3,000 actuators. DMs that have ? 128×128 actuators are required by these upcoming projects, as identified in the 2019 NASA Exoplanet Exploration Program Technology Gap List1. A Spatial Light Modulator (SLM) can offer more actuators (about 2 x 106 actuators) than a conventional DM. SLMs can also offer a compact solution to this large-format DM challenge. Thanks to recent advances, SLMs can now offer both the actuator count and control speed (.7 kHz) required for exoplanet imaging for both ground and space telescopes. It is envisioned that existing SLMs could one day serve as a second-order correction after a first coarse correction using a conventional DM. While SLMs offer a promising solution to the large-format DM’s actuator count challenge, they have not yet been used in high contrast imaging correction in broadband light, and their stability, polarization, and chromaticity must be better understood and accounted for. In this thesis work, an SLM device was characterized and validated in the lab for use in HCI, measuring its contrast stability, polarization cross-talk, and chromaticity in the lab.
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  Synergy Between Natural Antimicrobials Against Eschericha coli Bacteriophages

  Gerba, Charles P.; Sanchez, Ray Luther; Bright, Kelly R.; Ikner, Luisa (The University of Arizona., 2025)

  Household and industrial disinfectants are often used without consideration of their fate and transport after use. Disinfectant products are well known for their convenience and efficiency. However, they can potentially create hazardous chemical byproducts ranging from carcinogens to ecological degradation. To minimize these effects, alternative methods of sanitation using naturally occurring antimicrobials have been proposed and developed. These antimicrobials include complex organic molecules, essential oils (EOs), and inorganic acids. This research focused on organic acids and essential oils from various plant species that have been demonstrated in previous studies to have antiviral, antifungal, and antibacterial properties. To determine the effectiveness and possible synergy between combinations of these natural products, a series of experiments targeting bacteriophages with three different capsid and genomic characteristics were conducted including MS2 (ssRNA icosahedral), ?X174 (ssDNA icosahedral) and PR772 (dsDNA icosahedral with encapsulating membrane) bacteriophages with Escherichia coli hosts. The greatest degree of synergy for the substances tested was observed for several antimicrobial combinations against MS2 and PR772. Citric acid (1.0%) paired with either cinnamaldehyde (1.0%-3.0%) or carvacrol (0.1%-0.5%) had the greatest synergy and effectiveness against both MS2 and PR772 (increase in efficacy ranging from 0.80 to >3.42 log greater reductions than an additive effect). ?X174 was more resistant to most antimicrobials than both PR772 and MS2, and exhibited little synergy with most antimicrobial combinations, possibly because of its stable circular genome; however, several combinations were found with moderate yet significant synergistic increases in efficacy of 0.27 to 0.50 log greater reductions than an additive effect. The combination of carvacrol with cinnamaldehyde was the least effective with antagonism observed against PR772 and a likely only additive effect against the other two viruses, possibly due to the competition of both antimicrobials for the same site on the viral genome. Finding synergy as opposed to additive effects is important for reducing the volume of products used for sanitation.
• MULTISPECTRAL WIDE FIELD OF VIEW REFLECTIVE COLLIMATOR

  Sasián, José; Liang, Rongguang; Mitchell, Bradley Alan; Koshkin, Ilya (The University of Arizona., 2025)

  Wide field-of-view (WFOV) imaging systems are increasingly essential in modern optical applications such as autonomous navigation, remote sensing, and machine vision. However, their characterization and calibration require collimator systems capable of delivering high-quality, uniform, and spectrally broad illumination across large angular extents. This thesis presents the background on collimators, current solutions, and proposed multi-spectral reflective collimator system optimized for WFOV testing. The system employs an off-axis reflective architecture to eliminate chromatic aberrations inherent in refractive designs while maintaining diffraction-limited performance across visible to long infrared wavelengths. A custom optical configuration was developed to balance field uniformity, wavefront error, and manufacturability enabling precise alignment and repeatable test conditions for wide-angle sensors. The resulting collimator achieves high wavefront quality and spectral neutrality over an extended field. It offers a practical, high-performance solution for industrial and research environments. This work demonstrates a manufacturable approach that supports emerging needs in multi-spectral imaging and calibration of next-generation optical instruments.
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  Small Mammals Along Elevational Gradients & Ground-Dwelling Arthropods Along Red Squirrel Midden Residency Gradients, Pinaleño Mountains, Arizona

  Pasch, Bret; Tierney, Ellen Reed; Bledsoe, Ellen; Steidl, Robert (The University of Arizona., 2026)

  Ecosystem stability is important for threatened biomes such as the Madrean Archipelago that harbor endemic species of conservation concern. Small mammals play key ecological roles that influence ecosystem function (e.g. homeostasis, or how ecosystem structure remains constant in response to disturbances), yet knowledge of their distributions and interactions is lacking in the region. In my first study, I documented richness and abundance patterns of small mammals along an elevation gradient in the Pinaleño Mountains, the most prominent mountain range of the Madrean Archipelago. I found that species richness peaked in the semi-desert grassland and mixed conifer life zones, but the life zone with the greatest abundance varied seasonally. The study provides insight into factors influencing elevational distributions and serves as a baseline to incorporate monitoring of small mammals as indicators of environmental change. My second study investigated how endangered Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis) middens (cone scale piles where squirrels larderhoard food) influenced the community of ground-dwelling arthropods across a gradient of residency history. I found that middens that had longer squirrel residencies (squirrels residing at and maintaining the midden for longer time periods) were associated with more arthropods compared to lower residency middens. However, the diversity of ground-dwelling arthropods relative to squirrel residency history depended on the diversity metric used. Monitoring of arthropod communities within middens can provide a novel method to assess temporal changes in squirrel food-caching strategies and evaluate forest management actions that may influence midden conditions. Collectively, studying small mammal interactions across diverse gradients can identify new ways of seeing and responding to disturbances that the region may experience in the future.
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  Russo-Ukrainian War through the Lens of Serhiy Zhadan's War Diary

  Gordienko, Anastasia; Czerkawski, Betül C.; Jens, Benjamin; Thompson, Suzanne (The University of Arizona., 2025)

  In early 2022, when the Russian Federation launched a full-scale invasion of its neighboring country, Ukraine, Ukrainian writers used their pens to convey their everyday experiences under Russia’s continuous attacks. While other literary forms, such as novels, poetry, and plays, were written about the war, the diary emerged as a notable genre. The primary purpose of this study is to explore the style, content, and form in Zhadan's diary. Scholarly literature on diaries as a form of literary and historical documentation, such as Yanina Kulinska and Bruce Merry's works on war diaries, provides background for the study, which focuses on diary entries describing the daily experiences of ordinary Ukrainians during a period of national suffering. Although this study focuses on a single work by a single author, Serhiy Zhadan, the findings can nevertheless be extrapolated to illuminate a new generation of Ukrainian writers and the general themes that resonate with them, particularly their interpretation of Russia’s second invasion of Ukraine. By situating Zhadan’s work within the broader tradition of wartime diaries, the study highlights the interplay between the author's personal testimony and the collective memory of Ukrainians. It highlights how Zhadan's individual reflections not only document his lived experiences but also help form a national narrative. In doing so, the diary becomes both a literary artifact and a historical document, bridging the gap between private suffering and national identity.
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  Surveying the Growth of a Mycenaean State: A Reassessment of Pylian Expansion in Late Bronze Age Messenia

  Schon, Robert; Jones, Sawyer Jeremy; Blake, Emma; Stephan, Robert (The University of Arizona., 2026)

  This thesis reassesses the nature and timeline of the expansion of the Kingdom of Pylos in Messenia during the Late Bronze Age. Evidence from Linear B documents, excavations, and regional survey projects has provided substantial information about the administration and economy of the Pylian state during the height of its power at the end of the LH IIIB period, but the nature and timeline of its growth from a single settlement to the palatial capital of Messenia is not as fully understood. Messenian survey data are used here to catalogue, map, and analyze Mycenaean settlements in the region for the LH I-II, LH IIIA-B, and LH IIIC periods. Changes to settlement patterns that are indicative of Pylian expansion are identified through a combination of traditional and novel methods. These changes are then considered along regional lines, from which three distinct waves of Pylian expansion in Messenia during the Late Bronze Age are shown.
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  From Catch to Canvas: An Analysis of the Archaeofaunal Record of Minoan Sites and Symbolic Marine Iconography

  Schon, Robert R.; Parks, Elizabeth Nelson; Romano, David D.; Stephan, Robert R. (The University of Arizona., 2026)

  The Southern Aegean generally features oligotrophic waters punctuated by highly productivemicro-environments such as ravine estuaries and coastal lagoons. These ecological conditions support the multi-species environments that define the coastal fisheries of Akrotiri, Palaikastro, Mochlos, Pseira, and Kommos. The study analyzes of ichthyofaunal assemblages to identify the types of fish Minoan people caught, processed, and consumed at each site and to compare the assemblages across sites in order to distinguish any patterns that may indicate preference or unique circumstances. This analysis also compares these assemblages with modern Greek commercial fishing statistics to explore the long-term continuities and inconsistencies in fishing practices. The results demonstrate a strong preference for inshore fishing, as assemblages consist largely of small, demersal species, particularly the Sparidae and Centracanthidae families. Fishers occasionally targeted larger, pelagic species offshore, although they did so far less frequently. Minoan iconography reveals a distinct fascination with the marine environment and the animals that inhabited it. Despite the frequent depiction of sea creatures in Minoan art, the species people consumed rarely overlap with those represented iconographically. Instead, the Minoans appear to focus on the dolphin, a sea creature absent from the faunal assemblages, as their ‘key species’. Other fish appear only rarely or in vague forms within the iconographic record. These discrepancies suggest that the Minoans emphasized symbolic and visually striking marine animals, as opposed to those that formed their diet. The widespread occurrence of similar taxa across settlements suggests that multiple social strata commonly consumed fish rather than restricted by status, although certain contexts point to feasting events. Comparisons between ichthyofaunal data and marine iconography further demonstrate limited overlap in species representation. Everyday diets relied on small, reliable coastal fish, while Minoan visual culture highlighted pelagic species that symbolized the open ocean and the Minoan sea-faring identity. This divergence underscores the economic and cultural importance of the sea in Minoan society beyond subsistence.
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  Genetic Diversity and Connectivity of Lowland Leopard Frogs (Lithobates Yavapaiensis) in Southeastern Arizona

  Rick, Jessica; Bauder, Javan; Hasl, Beth; Vargas, Karla; Bogan, Michael (The University of Arizona., 2025)

  Aquatic habitats in arid landscapes are critical for biodiversity but are increasingly imperiled by habitat fragmentation and hydrological alteration. Amphibians in these environments are especially vulnerable due to their reliance on aquatic habitats that are separated by inhospitable terrain. The lowland leopard frog (Lithobates yavapaiensis), once widely distributed across the southwestern United States, has undergone substantial range reductions and is now largely confined to perennial aquatic systems. Despite being a species of conservation concern, little is known about its population structure or connectivity in southeastern Arizona. We used genome-wide single nucleotide polymorphism (SNP) data from double-digest restriction site-association DNA sequencing (ddRADseq) to investigate genetic diversity, population structure, and landscape genetics. We analyzed 492 individuals from 33 sites for population structure and 421 individuals from 29 sites for landscape genetic analyses. Genetic diversity was uniformly low across sites, consistent with small and isolated populations. Strong hierarchical genetic structure corresponded to five major geographic regions: Cienega Creek, Rincon Mountains, Catalina Mountains, Galiuro Mountains, and the San Pedro River Basin. Within regions, sites were genetically similar, consistent with dispersal along hydrological networks, whereas differentiation among regions indicated restricted gene flow across broader spatial scales. Genetic similarity declined sharply beyond approximately 10 km, and spatial analyses revealed that landscape features strongly influenced connectivity. Topographic position and solar exposure explained patterns of gene flow better than geographic distance alone, with valleys and shaded slopes facilitating movement while ridge-like and sun-exposed areas limited connectivity. Together, these results show that L. yavapaiensis populations are structured by both regional genetic differentiation and landscape heterogeneity. Conserving hydrological connectivity and low-resistance topographic and thermal corridors will be essential to maintain gene flow and support long-term population persistence in southeastern Arizona.
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  Power Side-Channel Leakage Assessment of FPGA-Based Spiking Neural Networks

  Salehi, Soheil; Pugazhenthi, Veeramani; Satam, Pratik; Dass, Jyotikrishna (The University of Arizona., 2025)

  On-chip learning refers to the process of training or updating machine learning models directly on specialized hardware, rather than relying on external computational resources such as CPUs or GPUs. On-chip learning offers reduced latency, energy efficiency, privacy, and adaptability. Hence, on-chip learning is a promising approach for enabling intelligent decision-making and adaptability in edge and IoT devices while addressing the challenges posed by limited resources and data privacy concerns. One of the main features of on-chip learning involves adapting synaptic weights within a Spiking Neural Network (SNN), allowing dynamic adjustments of the network's behavior to align with desired outcomes. Such adaptability is a double-edged sword, as it opens doors for potential security vulnerabilities. Unaddressed security risks in on-chip learning could lead to a wide range of threats, including data leaks, unauthorized access, and even adversarial manipulation of the learning process. In this work, we demonstrate a successful power side-channel attack (SCA) targeting a quantized SNN deployed on the CW305 FPGA using ChipWhisperer. Our analysis reveals consistent power leakage patterns correlated with neuron updates, enabling attackers to infer internal model attributes without accessing model weights or inputs. Furthermore, we extend this analysis by performing a Correlation Power Analysis (CPA) attack to successfully recover the secret synaptic weights of the network. Using a Hamming Weight leakage model, we demonstrate that these weights can be extracted with high confidence using as few as 1500 power traces. This thesis aims to provide a comprehensive overview of the security risks associated with on-chip learning, highlighting the potential vulnerabilities within the SNN architecture. We will examine real-world scenarios in which these vulnerabilities can be exploited and discuss their implications for applications in IoT, edge computing, and other domains. Furthermore, this thesis will outline safeguards and mitigation strategies to address these security concerns at the software-hardware boundary. We will explore design principles, cryptographic techniques, and access control mechanisms that can be used to secure on-chip learning systems without impacting their performance.
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  Where’s My Sister? The Experience of Ambiguous Loss in Native American Communities with Missing Native American People

  O'Connor, Mary-Frances; Pino, Yvette; Sbarra, David; Sullivan, Daniel (The University of Arizona., 2025)

  In 2016, 5712 Native American women went missing in 2016 alone, which is considered to be a low estimate due to complex jurisdiction issues and inaccurate missing person’s databases. Often these cases go unsolved for years, if they are solved at all, which can lead to many Indigenous people experiencing ambiguous loss. Ambiguous loss is the experience of uncertainty of whether a loved one will return, and closure remains unobtainable. Loved ones who are experiencing ambiguous loss are left hoping that their loved one is alive, which may draw out the grieving process, further exacerbating these health disparities. The present study is a national online survey that was distributed to a wide sample of Native Americans (n=234), in order to reflect the diversity that exists in the many tribes and Indigenous groups that exist in the US. The survey included questionnaires assessing ambiguous loss using the Ambiguous Loss Inventory + (ALI+), grief, depression, trauma symptoms, and enculturation. Analyses were conducted in R Studio, and a regression indicated that for those with a missing loved one had higher grief severity than those with a death-related loss. A regression also indicated that the ambiguous loss group also had higher depression and trauma symptoms than the death-related loss group and the group with no loss. Finally, the moderation analysis did not show significant moderation of enculturation on the relationship between loss group and grief severity. Indigenous communities must be allowed the opportunity to practice traditional ceremonies that promote healing and closure, while also increasing awareness for this issue.
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  A Quality Improvement Project of Behavioral and Family Dynamic Changes of Children and Adults With Autism That Use Home Photobiomodulation Devices

  Celaya, Melisa P.; Larson, Samuel; Lee-Iannotti, Joyce; Garcia-Filion, Pamela C. (The University of Arizona., 2025)

  Background: Autism Spectrum Disorder (ASD) affects approximately 1 in 36 children in the United States. Core features include deficits in social communication, repetitive behaviors, and associated comorbidities such as irritability, aggression, and sleep disturbances. Neuroinflammation and immune dysregulation are increasingly recognized as contributing factors in ASD pathophysiology. Transcranial photobiomodulation (tPBM), a non-invasive neuromodulation technique utilizing red and near-infrared light, has demonstrated neuroprotective, anti-inflammatory, and cognitive benefits in several neurological conditions. Preliminary evidence suggests potential therapeutic effects of tPBM in ASD.Objective: This study analyzed collected survey data from parents of adolescents and young adults with ASD who participated in at-home, self-guided sessions using twice-daily ProNeuroLIGHT transcranial and abdominal photobiomodulation therapy. The goal was to examine trends, patterns, and potential impacts of the intervention on non-compliant behaviors and parental stress, with secondary consideration of sleep quality. Methods: Twenty-one participants aged 5–34 years (mean age 11.7; 15 males, 6 females) from Latin America origin who used infrared/red LED head caps and abdominal wraps twice daily for 20 minutes. Parents completed validated Spanish versions of the Home Situation Questionnaire–ASD (HSQ-ASD) and Autism Parenting Stress Index (APSI) at baseline and follow-ups. Paired t-tests, Wilcoxon tests, and mixed-model analyses were performed to assess changes over time, with significance set at p < 0.05. Results: Statistically significant improvements were observed from baseline to both follow-up points. By the final follow-up (mean 129 days), HSQ total scores decreased by 32.7 points (p < 0.0001), HSQ mean severity scores by 1.4 (p < 0.0001), SI and DS subscale scores by 15.8 and 16.9 (p = 0.0009 and < 0.0001, respectively), and APSI scores by 13.5 (p < 0.0001). Mixed-model regression confirmed consistent daily reductions across all measures. Neither age nor sex showed significant effects. Discussion: Results indicate that combined transcranial and abdominal PBM was associated with significant reductions in non-compliant behavior and parental stress. Potential mechanisms may include modulation of neuroinflammation, improvement of gut microbiome balance, and enhancement of glymphatic clearance systems often disrupted in ASD. Conclusion: Transcranial and abdominal photobiomodulation appears to be a safe, well-tolerated, and promising non-invasive intervention for reducing behavioral challenges and caregiver stress in the ASD population that participated. Further large-scale, controlled trials are warranted to confirm efficacy, establish standardized treatment parameters, and explore underlying physiological mechanisms.
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  Optimization of Additively Manufactured Wind Turbine Blades

  Missoum, Samy; Pimienta, Isaac; Hazeli, Kavan; Li, Peiwen (The University of Arizona., 2025)

  Energy production in wind turbines can be increased in three main ways: lengthening the blades, accessing high wind speeds, and optimizing turbine efficiency. Increasing the blade length has been a common way to substantially increase wind turbine energy production. However, this trend of longer blades has led to many challenges, in particular, structural challenges from larger deflections, logistical challenges from transportation difficulty, and manufacturing challenges from the lack of specialized manufacturing warehouses.Additive manufacturing (AM) has shown promise in addressing some of these challenges by enabling complex, optimal geometries, simplifying manufacturing, and increasing accessibility by printing the blades on site. In order to leverage AM, this thesis investigates the use of computational optimization, in particular multi-objective optimization, to balance competing objectives as a means to determine the optimal design of wind turbine blades. The optimal design will be a compromise between annual energy production (AEP) and various structural performance metrics. This goal is achieved by first investigating two AM feasible internal structures, lattice-based and topology optimized designs. These two designs are compared across key performance metrics, including compliance and natural frequency. The topology optimized design demonstrates superior performance and is selected for a full multi-objective blade optimization. This multi-objective optimization is performed to maximize both the annual energy production and first natural frequency. The performances of the resulting optimal designs are then quantified through comparison to an existing optimal composite wind turbine blade. Overall, the findings highlight the potential of optimization-driven additively manufactured blade design.

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