• 

  BOUND ON THE NUMBER OF SIMULTANEOUSLY BAND- AND TIME-LIMITED QUASI-MONOCHROMATIC FREQUENCY MODES

  Guha, Saikat; Cox, Ali; Guha, Saikat; Wilson, Dalziel; Soh, Daniel (The University of Arizona., 2025)

  Based on insight from three seminal papers by Landau, Pollock and Slepian, which introduce the prolate-spheroidal wave functions as an optimal basis for almost completely capturing the degrees of freedom of a certain class of simultaneously time and band limited functions, we introduce an alternative set of narrow-band functions and discuss how the properties of the optimal prolate-spheroidal basis impose a bound on their number in terms of the time-bandwidth product.
• 

  Increased Sensitivity to CGRP is Associated with Chronification of Migraine and Post-Traumatic Headache in Male and Female Mice

  Porreca, Frank; Guzman, Gege Mariah; Porreca, Frank; Navratilova, Edita; Kopruszinski, Caroline M. (The University of Arizona., 2025)

  Migraine is one of the leading causes of disability affecting approximately 15% of the global population. Some individuals are more susceptible to the chronification of migraine with at least 2.5% of the patient population developing chronic migraine (CM) annually. Chronic headache disorders disproportionally affect women, with migraine occurring two to three times more often than in men and presenting with greater attack frequency and severity. These differences raise the possibility of sex-specific mechanisms contributing to migraine pathophysiology. The success of CGRP targeting therapies for both the acute and preventative treatment of migraine highlight CGRP’s crucial role in migraine pathophysiology. Recent findings have demonstrated that CGRP produces female-selective pain, and additionally, acute migraine treatments targeting this peptide exhibit sex-preferential effectiveness that becomes comparable between sexes in chronic conditions. Men appear to experience less therapeutic benefit from CGRP targeting therapies for acute migraine treatment, despite these treatments providing significant relief for women. However, studies further exploring sexually dimorphic mechanisms and incorporating sex-based analysis remains limited, leaving the influence of biological sex on headache chronification largely unexplored. Preclinical studies further support the clinical observations of CGRP-targeting therapies for CM, demonstrating the essential contribution of CGRP for the chronification of migraine. Interestingly, post-traumatic headache (PTH) from mild traumatic brain injury (mTBI) seems to share biologic features with migraine, however mechanisms are not fully understood. CGRP also appears to contribute to this headache condition, which shares migraine-like features and responds to migraine-specific therapeutics. Although concussive injuries are more frequently reported in men, women tend to experience worse outcomes and are more likely to develop persistent PTH, defined as injury-associated headaches lasting beyond three months. Differences in the physiology of the trigeminovascular system, specifically CGRP signaling within this system, may underlie susceptibility to headache chronification. This research aims to provide insight into the fundamental mechanisms of the sexually dimorphic nociceptive actions of CGRP and its contribution to migraine and migraine-like headaches as disorders evolve to chronic states.
• 

  War and the Moral Equality of Combatants: An Adjusted Conception

  Clark, David; Powell, Sean Michael; Joshi, Hrishikesh; Smit, Albert (The University of Arizona., 2025)

  According to a traditional account of Just War Theory, combatants are moral equals regardless of whether they are engaged in a just or unjust war. This means, roughly, that combatants on either side of the war have the same permissions to harm combatants on the other side. Traditionally, however, the scope of this principle has not been well defined. Precisely who counts as a combatant has been left in the air. Getting clear on the scope of the equally of combatants is immensely important though, if we are to act morally in war. If we only use history as a guide, the scope issue is less concerning when both sides of a conflict line up in neat rows of contradicting brightly colored uniforms, complete with flying national ensigns and bandsmen playing national songs, it would be hard to confuse either side as noncombatants. In the modern era however, this line between combatant and noncombatant cannot be drawn using easily distinguished uniforms or placement in the battle space. In fact, many modern fighters do not wear any distinguishing marking and are not claimed a nation or independent state as members of an organized armed forces. So, the question looms for the application of Just War Theory in this age of non-conventional warfare: who are the combatants that are supposed to be moral equals?
• 

  Vertical Radiative Cooling Enabled by Reflective Mirror Geometry and Spectrally Selective Physical Modeling

  Elkabbash, Mohamed; Chen, Weijie; Peng, Leilei; Chalifoux, Brandon D.; Elkabbash, Mohamed (The University of Arizona., 2025)

  Radiative cooling is a passive cooling method that can reduce electricity use by emitting heat into outer space through the atmospheric transparency window (8–13?µm). Most current designs use horizontal emitters, which are limited by rooftop space in cities. In contrast, vertical surfaces such as building façades are more abundant, but have received little attention due to fundamental physical limitations: they suffer from restricted sky exposure and increased absorption of thermal radiation from the ground and surrounding structures, which significantly reduce net cooling performance when analyzed using conventional models. In this study, we propose a new physical model for vertical radiative cooling, incorporating angular and spectral selectivity as well as geometrical view factor constraints. Based on this model, we design a vertical radiative cooling system that uses angularly and spectrally selective emitters, combined with a reflective mirror placed below the emitter. This design improves the effective emission angle and blocks thermal radiation from the ground. Simulation results show that under typical urban conditions like Phoenix, Arizona, USA (30 °C ambient, atmospheric transmittance ? = 0.8, parasitic heat coefficient h = 0.8?W/m²·K), the system can achieve a net cooling power of 16.13 W/m². We also show that with four vertical panels and one horizontal emitter, the system can deliver over 1 kW of total cooling power. Even without rooftop components, a vertical surface area of 62 m² is enough to reach kilowatt-level cooling. These results suggest that vertical radiative cooling is a practical and scalable solution for reducing cooling energy use in dense urban areas, enabled by a physics-based framework tailored to vertical emitter geometry.
• 

  Columnar to Equiaxed Transition in Spot Melt Electron Beam Powder Bed Fusion Scan Strategy and Utilization of Microstructure Informatics

  Tin, Sammy; Madigan, Michael Edward; Wessman, Andrew; Muralidharan, Krishna (The University of Arizona., 2025)

  Electron beam powder bed fusion (EB-PBF) has significant potential for achieving controlled microstructural development in additively manufactured components while addressing anisotropic mechanical property limitations inherent to conventional powder bed fusion processes. This work evaluated the columnar-to-equiaxed transition behavior and microstructural refinement characteristics of spot melt scanning strategies in EB-PBF processing. IN718 specimens were processed using four distinct scanning patterns and subjected to comprehensive microstructure informatics analysis to examine relationships between processing parameters, thermal management, and resulting grain morphology characteristics. Specimens underwent systematic beam current and dwell time variations to investigate the influence of energy density on microstructural evolution mechanisms. In addition, traditional raster scanning was examined to provide context for comparison with the experimental spot melting approaches. Microstructural characterization was performed using electron backscatter diffraction (EBSD) combined with quantitative informatics methodologies, in which comprehensive statistical analysis of grain dimensions and aspect ratios was conducted to establish processing-structure relationships. Aspect ratio measurements for the spot melting specimens were found to vary by factors of two to four compared with traditional raster scanning results, demonstrating the effectiveness of temporal separation strategies for columnar-to-equiaxed transition control. Scanning pattern configuration did not indicate a significant impact on densification behavior when adequate energy density was maintained. Moreover, equiaxed microstructural development appeared predominantly in specimens with optimized temporal separation between adjacent melt events as confirmed through three-dimensional EBSD reconstruction analysis. The work presented provides systematic assessment of the relationship between spot melting processing conditions, resulting microstructural characteristics, and thermal management strategies, while offering insight into development pathways for improved mechanical isotropy in this technologically important manufacturing process.
• 

  Habitat and Stocking Strategies for Native Fish Recovery in the Verde River Basin, Arizona

  Bonar, Scott A.; Jenney, Christopher John; Bogan, Michael T.; Bauder, Javan M. (The University of Arizona., 2025)

  Native fishes of the Colorado River Basin in the southwest United States rank among the most imperiled faunal groups worldwide. Their decline is linked to widespread habitat alteration and the subsequent proliferation of nonnative fishes that compete with and prey upon native taxa. Despite decades of conservation efforts, many of the native fishes remain at risk of extinction and there is continued interest in effective recovery strategies across the basin. This dissertation presents detailed investigations of native southwestern fishes, with a particular focus on Razorback Sucker Xyrauchen texanus in the Verde River, Arizona, a key tributary within the Gila River Basin. In this dissertation, I 1) review Razorback Sucker abundance, distribution, and conservation efforts within the Gila River Basin from 2004-2021, 2) evaluate and compare the survival and movement patterns of large (> 250 mm TL) and small (< 250 mm TL) Razorback Sucker stocked into mainstem and reservoir environments of the Verde River, 3) detail novel helicopter stocking methods for translocating endangered fishes to remote locations, and 4) assess how native fish abundance and habitat selection changes in response to nonnative piscivores in Fossil Creek, Arizona. More than 11 million Razorback Sucker were stocked into the Gila River Basin between 1980 and 2004; however, a population has failed to establish. From 2004-2021, 17,313 Razorback Sucker were stocked into the Verde River; but < 0.10% have been recapture and success has been limited. In 2022, I initiated a three-year stocking effort in which approximately 2,500 Razorback Sucker of two size classes were released annually in two locations, the mainstem Verde River and Horseshoe Reservoir. The goal was to evaluate whether reservoir stockings could enhance Razorback Sucker survival. In 2022 and 2023, the survival of small and large Razorback Sucker was negligible regardless of stocking location; however, in 2024 the 9-month post-stocking survival of Razorback Sucker increased to 5.7%. Overall, the survival of large fish was significantly greater than that of small fish and survival in the reservoir was higher than in the river. Mortality was attributed to water quality, specifically high-water temperature and stratification in the reservoir, as well as predation by nonnative fishes and piscivorous birds. Nonetheless, the survival of some Razorback Sucker in Horseshoe Reservoir offers hope for the species’ persistence in the Verde River Basin. Stocking Razorback Sucker into the mainstem river environment presented logistical challenges because it is inaccessible to traditional hatchery vehicles. I therefore commissioned a helicopter to transport Razorback Sucker to a remote location on the Verde River and compared the survival of fish stocked by helicopter to those stocked by conventional hatchery truck. The four-week post-stocking survival of fish stocked by helicopter and those stocked by hatchery truck into Horseshoe Reservoir was similar. Many of the observed mortalities were distant from release sites, suggesting fish mortality was not attributable to the stocking practices. Stocking fishes with a helicopter can be useful for fisheries conservation as it did not impact fish survival and allowed for broader distribution of stocked fish into previously inaccessible environments. Finally, I conducted snorkel surveys in Fossil Creek, Arizona, a Verde River tributary with an entirely native fishes upstream and a native and nonnative fishes downstream of a fish barrier to evaluate differences in species abundance and habitat selection in native fish communities with and without nonnative fish. The abundance of all Roundtail Chub Gila robusta, small (< 127 mm TL) Sonora Sucker Catastomus insignis, and all Speckled Dace Rhinichthys oscullus was significantly lower when sympatric with nonnative fishes; however, Desert Sucker Catostomus clarkii abundances were similar between reaches. When black bass were present, native fishes avoided pools and increased their selection for riffles, a likely predator avoidance behavior. These results highlight the distributional and behavioral consequences of native fishes occupying the same stream as nonnative fishes and highlights the importance of maintaining specific habitat-types when nonnative fishes are present in a river. Collectively, this research highlights the persistent challenges of conserving native fishes in the Verde River and offers practical insights to guide and improve future conservation efforts throughout the basin.
• 

  Mechanisms of Asthma Protection by Microbial Agents

  Vercelli, Donata; VanLinden, Sydney; Romanoski, Casey; Meyers, Deborah; Cusanovich, Darren; Pivniouk, Vadim (The University of Arizona., 2025)

  Asthma is the most common chronic disease of childhood and global prevalence has increased significantly in recent decades, coinciding with a shift in exposure to microbes present in the environment. Our lab previously showed that airway administration of microbial agents, such as Amish farm dust extracts (AFDE) or the bacterial lysate OM-85 (Broncho-Vaxom), protects against experimental asthma and has profound transcriptional effects in an ovalbumin murine model of experimental asthma. However, transcriptional mechanisms underlying the asthma protective effects of AFDE and OM-85 require further investigation. The work described in this dissertation sought to characterize the cellular and transcriptional modifications induced in the lung by AFDE and OM-85 using an Alternaria alternata extract-induced experimental asthma mouse model. Considering the phenotypic similarities, a comparison was performed to determine whether AFDE and OM-85 confer asthma protection by similar changes in transcription. Lung function and bronchoalveolar lavage (BAL) cellularity were measured in BALB/c wild-type-mice treated intranasally (i.n.) with either AFDE or OM-85 in the presence or absence of Alternaria extracts. Lung tissue collected from these mice was used to perform flow cytometry, bulk RNA-seq, and single nucleus (sn)RNA-seq to profile and compare the responses to AFDE and OM-85. This work showed that the protection conferred by AFDE and OM-85 involves the differential expression of several shared genes. Both microbial agents suppress airway hyperresponsiveness (AHR) and eosinophilia, downregulate genes involved in type-2 inflammation, and induce a strong, activated, polyclonal B cell signal. Ongoing studies in B cell deficient mice seek to determine whether B cells are required for the asthma protective effects of AFDE.
• 

  Increasing Provider Awareness of Evidence-Based Screening Tools to Identify Insomnia

  Young, Janay R.; Meitl, Denise; Sparks, John R.; Shaver, Joan L. (The University of Arizona., 2025)

  Background: Insomnia (poor sleep) is a highly prevalent patient-reported symptom that impactsnearly every health-related metric. In its persistent forms, patients may have symptoms meeting DSM-5-TR criteria for a sleep-wake disorder. As a symptom, it is often under-assessed, under-diagnosed, and under-treated, predisposing individuals to have persistent and worsening manifestations and subsequently develop physical health illnesses and mental health disorders. Standardized screening across diverse health conditions, such as insomnia, has been shown to improve recognition, diagnostic accuracy, tailored treatment planning, and patient outcomes. As the basis for standardized screening and the ISE intervention for this project, the ISI, a validated self-report questionnaire designed to assess the severity of insomnia symptoms in clinical practice, was implemented. Purpose: The aim of this quality improvement (QI) project was to evaluate an educationalintervention to motivate clinician use of a validated, evidence-based screening tool, the Insomnia Severity Index (ISI). The overall goal was to improve the identification of insomnia among clinic patients. The Insomnia Severity Education (ISE) intervention was designed to enhance healthcare provider outcomes of 1) insomnia screening knowledge, 2) confidence in using the ISI, and 3) intention to incorporate insomnia screening, specifically the ISI, into routine clinical practice. Methods: An evaluative design utilizing pre- and post-intervention measures was employed toassess the effectiveness of the ISE intervention in enhancing provider knowledge of insomnia screening, confidence in using the ISI, and intention to incorporate insomnia screening, specifically the ISI, into clinical practice. Healthcare providers from a community health center in southern Arizona were invited to participate voluntarily, with three providers completing all components of the intervention. The link to the ISE intervention was distributed through the organization’s internal email system. Descriptive statistics were used to evaluate and interpret the survey data. Results: Post-intervention survey responses indicated increases in healthcare providers'knowledge of insomnia screening, confidence in using the ISI, and intent to implement the ISI in clinical practice. Descriptive statistics revealed positive shifts in all three domains, with providers reporting increased familiarity with the ISI and its clinical applications. The anonymous, self-matched pre- and post-surveys demonstrated that a brief, asynchronous educational intervention was effective in promoting awareness and readiness for practice change. Conclusions: The findings suggest that brief, asynchronous education can be an effectivestrategy for enhancing provider knowledge and confidence in screening for insomnia. The increase in intention to incorporate the ISI into clinical assessments highlights the potential of targeted educational interventions to support the adoption of evidence-based tools in everyday practice. These results support the feasibility and value of integrating insomnia screening into routine care through provider-focused education.
• 

  Algorithms and Theory of Bandits in Practical Setups

  Jun, Kwang-Sung; Zhao, Yao; Jun, Kwang-Sung; Pacheco, Jason; Zhang, Chicheng; Li, Ming (The University of Arizona., 2025)

  Multi-armed bandit is a central paradigm for interactive machine learning, where an agent must learn efficiently from adaptive feedback. From a data collection point of view, bandit algorithms can be applied as a tool for efficient sequential data collection and serve as a powerful method to solve many real-world problems. This perspective leads to the pure exploration problem, where the goal is to focus entirely on data exploration during the learning process and use the collected data for a final task, such as decision-making or model training. A key aspect of this framework is that individual data collection steps do not have an immediate impact on a final objective. This distinguishes the pure exploration framework, which has recently shown its strength in many practical problems, from the more traditional regret minimization framework with a cumulative objective. In this dissertation, three problems are studied around this theme, ranging from theoretical foundations to practical applications. The first problem addresses a gap in the theoretical understanding of simple regret, a fundamental yet under-explored performance measure in pure exploration; since its proposal, a rigorous, instance-dependent characterization has been lacking. The second problem arises in experimental settings, such as clinical trials, where bandits are a powerful tool for accelerating discovery. However, factors like user non-compliance can confound the experimental results. We address the question of how to design efficient pure exploration algorithms to support critical decision-making in the presence of such confounding factors. The third problem concerns the alignment of Large Language Models (LLMs), which often requires a high-quality preference dataset that is expensive to collect. We study how to design efficient data exploration strategies to improve the sample efficiency of preference learning. These three problems share the common theme of efficient data collection for a final task, where the immediate impact of each data collection step is disregarded in favor of the terminal objective. This dissertation tackles these three problems by developing a suite of novel algorithms and analyses to address each of them. A common goal across all contributions is the provision of an instance-dependent guarantee for each problem. This is more practical and fine-grained than the worst-case bounds commonly seen in the literature, providing a more complete, problem instance level characterization that reflects the intrinsic difficulty of each specific task.
• 

  Field of Dreamers: Becoming Mexican American through the National Pastime

  Pérez, Erika; Nunez, Alex; Vetter, Jeremy; Steptoe, Tyina; García, Juan R.; Magaña, Maurice R.; Alamillo, José (The University of Arizona., 2025)

  The Mexican American population of the United States increased sixfold during the first half of the twentieth century. Through hostile working and living conditions, Mexican Americans established communities in the southwestern borderlands, cities, and rural areas, where they carved out important social spaces and engaged in practices that established connections between their ethnic Mexican backgrounds and their new American environments. This dissertation argues that Mexican Americans in the first half of the twentieth century used baseball as a vehicle to establish hybridized identities as Americans with a Mexican cultural heritage, to form communities around that shared identity, and to confront racialization in the United States in search for a sense of belongingness. Using extensive archival research from newspapers, oral histories, artwork, material culture, magazines, and Spanish-language sources, this project builds upon historiography established by works in Mexican American history, sports history, labor history, intellectual history, and gender studies. Baseball proved malleable enough to accommodate the various needs of this heterogeneous population, who differed in national origin, socioeconomic backgrounds, geographic settings, linguistic abilities, and age groups. Mexican Americans molded this American cultural activity to fit their own needs while reckoning with prevailing ideas about race, gender, class, and nationalism. They sustained important elements of their Mexican heritage while adopting American perspectives and ideologies, and fused together new identities in the process. Participating in the national pastime provided Mexican Americans with more than a recreational outlet; it provided them with the self-efficacy to express cultural citizenship, establish communities, demonstrate the fortitude of their shared cultural heritage, and to find a sense of belonging, both on and off the baseball diamond.
• A Clinical Translational Approach to Understanding Oxytocin and Maternal-Infant Bonding in Postpartum Mothers with Opioid Use Disorder

  Allen, Alicia; Mallahan, Stephanie Elise; Bell, Aleeca; Farlan, Leslie; Rankin, Lela (The University of Arizona., 2025)

  It is currently unknown whether oxytocin mechanisms, the hormone underlying maternal bonding, are altered when there is a damaged reward system from opioid use disorder (OUD), and the impact this may have on the maternal/infant bonding relationship. This is a critical gap in the literature that this dissertation seeks to investigate. In paper 1, a scoping review found in the clinical literature that those with OUD had lower levels of endogenous oxytocin, and overall that exogenous oxytocin may benefit individuals with substance use disorders, particularly those with an alcohol use disorder or OUD. In paper 2, a study found no significant differences in mean oxytocin levels between mothers with (n=6) and without OUD (n=7) before (mean difference: 15.23 pg/mL, p=0.271, d = 0.67) or after a caregiving activity (post activity 1: 11.26, (p=0.441, d=0.78; post activity 2: p=0.320, d=1.14). While bonding measures did not significantly differ, there was a marginal non-significant difference after the caregiving activity (p=0.065), where mothers with OUD reported feeling 100% connected to their baby, compared to 86.9% among those without OUD; suggesting a possible disconnect between the physiological oxytocin response and subjective connection. Additionally, in paper 3 a multivariate linear regression showed that psychological distress emerged as the strongest predictor of bonding (p<0.000), with oxytocin showing no significant effect in either group (n=24 with OUD, n=17 without OUD). Adverse childhood experiences influenced bonding only among those without OUD (p=0.004), while among those with OUD higher adversity scores were associated with less impaired bonding, though these findings were not significant. Given the small sample sizes and limited statistical power, future research should examine resilience factors that may contribute to oxytocin regulation, bonding, and potential translational interventions for high-risk populations.  
• Improving Zero-shot Relation Extraction via Rule-based and Prompt-based Methods

  Surdeanu, Mihai; Rahimi, Mahdi; Jun, Kwang-Sung; Pacheco, Jason; Blanco, Eduardo (The University of Arizona., 2025)

  Relation extraction (RE) is a foundational task in information extraction that aims to identify semantic relations between entities from unstructured text. While supervised relation extraction models have considerably advanced the state-of-the-art, they often perform poorly in low-resource settings. Zero-shot RE is vital when annotations are not available either due to costs or time constraints. As a result, zero-shot RE has garnered interest in the research community. In this dissertation, we propose rule-based and prompt-based methods to advance zero-shot RE. First, we introduce a new rule learning method that given a seed rule, learns many rules with a synonymous meaning. Rule-based approaches have the advantage of interpretability. Furthermore, the interpretability provided by rules is actionable. On the other hand, rule-based approaches lack the generalization power of deep learning systems. In this work, we aim to marry the advantages of the two directions. To that end, we propose an extension to Harris (1954)’s distributional hypothesis for rules. In particular, we propose to measure the similarity between pairs of slots (i.e., the set of concepts matched by a rule) using contextualized embeddings instead of lexical overlap. Empirical results demonstrate that this new similarity method yields a better implementation of the distributional hypothesis. Next, we develop a zero-shot RE method that formulates RE as a textual entailment task. Our method automatically generates templates using our extension of the distributional hypothesis to rules. These templates verbalize relation types, and are fed as hypotheses to an off-the-shelf entailment engine for classification. Our method achieves state-of-the-art performance for zero-shot TACRED, a popular RE benchmark. Finally, we introduce an effective prompt-based method for RE. With the arrival of large language models, many approaches have been proposed for RE, but they are often ineffective or require an accompanying masked language model or complex post-prompt processing. In this work, we propose a high-performing prompt-based method for RE that does not require any additional resources. Our experiments on four main RE datasets showed that our method outperforms previous state-of-the-art by a large margin.
• Multi-Dimensional Analyses into Plant Processing and Technological Changes during the Paleolithic-Neolithic Transition in North China

  Kuhn, Steven L.; Chen, Ran; Stiner, Mary C.; Holliday, Vance T.; Killick, David J. (The University of Arizona., 2025)

  This project examines economic and technological specialization associated with the adoption of agriculture in North China between 26,000 and 8,000 years ago. The origins and spread of agriculture represent one of the most significant economic transitions in human history. It is widely believed that agricultural economies led to increased economic specialization and division of labor, two central aspects of modern economies. This specialization is thought to be reflected in technology, particularly in the development of specialized tools for processing agricultural products such as grains. In China, early farmers adopted ground-edged tools while continuing to use flaked tools and grinding stones, technologies inherited from their hunter-gatherer ancestors. This dissertation investigates whether economic and technological specialization was an inevitable outcome of plant processing or whether it occurred only in certain contexts. To address this question, I examine how a range of stone tools were actually used before and after the adoption of agriculture.The data for this study come from the Peiligang site in the Middle Yellow River Basin of North China. This region is particularly well suited for such a study because it was a center of early mixed millet and rice agriculture and contains cultural components spanning from the Upper Paleolithic to the Early Neolithic, with both pre-agricultural and agricultural practices represented within the same locality. Artifact functions were investigated using two independent lines of evidence. The first is use-wear analysis, which examines physical alterations on tool surfaces to infer motions of use and contact materials, such as soft plants, wood, animal tissue, hide, and bone. The second is microfossil residue analysis, including starch grains, phytoliths, and microfibers, which provide direct evidence of the plants that people were cutting, grinding, and scraping with these tools. By integrating experimental models with archaeological evidence, I propose a new interpretation of the persistence of flaked tools alongside innovations in ground stone technology. Specifically, my experiments suggest that compared to flaked tools, ground-edged stone tools do not show significantly increased efficiency in harvesting grasses, but that they are more efficient for harvesting fibrous plants and weeds. Supported by correlations from archaeological analyses, I argue that ground-edged stone tools were developed in response to the long-term and large-scale demands of bast fiber processing in the Early Neolithic. Although they were also commonly used for harvesting and processing plant foods, these functions were shared with flaked tools. Grinding stones, by contrast, show a trajectory of intensification rather than replacement, with larger and more complex forms supporting sustained processing of cereals and other plants. Residues preserved in pottery vessels further demonstrate the diversification of plant use, including alcohol production and ritualized consumption. Together, these lines of evidence reveal that toolkits became increasingly specialized not through simple substitution of old technologies with new ones, but through overlapping and complementary roles in food and non-food plant processing. This dissertation therefore offers new insights into the dynamics of technological continuity and innovation within broader social, cultural, and environmental contexts.
• Phenotypic Characterization of a New Rat Model of Catecholaminergic Polymorphic Ventricular Tachycardia Type 3

  Hamilton, Shanna; Torrel, Brett Douglas; Pappas, Christopher; Song, Taejeong (The University of Arizona., 2025)

  A spectrum of inherited and acquired cardiovascular disease can cause sudden cardiac death from calcium (Ca2+)-dependent ventricular arrhythmias. These arrhythmias are largely driven by hyperactivity of the sarcoplasmic reticulum (SR) Ca2+ release channel, the cardiac ryanodine receptor (RyR2). Treatment options to attenuate arrhythmia are limited or of poor efficacy. Therefore, it remains a priority to understand molecular mechanisms underlying RyR2 hyperactivity in disease for improved therapeutic design. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare type of arrhythmia that has a lethal phenotype associated with Ca2+ mishandling. The disease typically presents in juveniles as ventricular tachycardia and fibrillation after stress or exercise, which can lead to sudden cardiac death. Mutations associated with CPVT are typically in RyR2 or its accessory proteins. CPVT3 is a recently reported subtype of the condition associated with mutations in trans-2,3-enoyl-CoA reductase-like protein (TECRL). Little is known about the function of TECRL in the heart, other than its localization to the sarcoplasmic reticulum. It remains entirely unknown how mutations in TECRL lead to an arrhythmogenic phenotype associated with intracellular Ca2+ mishandling and RyR2 hyperactivity. Here, we developed a new rat model of CPVT3 using CRISPR-Cas9 to introduce a patient-asssociated TECRL mutation, the single nucleotide polymorphism c.331+1G?A. Our studies with homozygous TECRL-SNP rats revealed no global cardiac remodeling, typical of the CPVT phenotype. Importantly, the rat exhibits a strong arrhythmogenic phenotype, presenting with VTs after challenge with epinephrine and caffeine. In contrast to other types of CPVT, these rats also presented with premature ventricular contractions even at baseline conditions. Confocal microscopy revealed that TECRL-SNP leads to RyR2 hyperactivity and intracellular Ca2+ mishandling, although the molecular mechanism underlying this remains unclear. Overall, we demonstrate that the TECRL-SNP rat has a strong arrhythmogenic phenotype for future studies of CPVT3.
• Impact of mPFC-vHC Oscillatory Synchrony on Age-Related Deficits in Spatial Working Memory

  Barnes, Carol A.; Sterzinar, Christopher; Cowen, Stephen L.; Eggers, Erika (The University of Arizona., 2025)

  Among the cognitive functions susceptible to age-related decline, spatial and working memory functions are particularly affected. The hippocampus (HC) and medal prefrontal cortex (mPFC) are two brain regions essential for executing these cognitive processes. Communication between these regions is thought to be facilitated by theta (6-12Hz) oscillations, and increased theta synchrony between these regions is has been shown to correlate with improved performance on spatial working memory tasks. However, the impact of aging on interactions between these regions and their relationship to declines in spatial working memory function is unclear. To investigate these differences, we trained healthy young (9 months) and aged (22 months) Fischer 344 rats on the Morris watermaze and the W-maze spatial alternation tasks. Aged rats exhibited impaired performance on both the spatial and spatial working memory components of the tasks relative to young animals. Following acquisition of the spatial alternation task, rats were surgically implanted with dual-bundle hyperdrives that simultaneously recorded electrophysiological signals from the prelimbic and infralimbic regions of the mPFC and the CA1 regions of the intermediate and ventral HC (ivHC) during the spatial alternation task. Robust theta was observed in both the mPFC and ivHC of young and aged rats during task completion. When evaluating theta coherence between the mPFC and ivHC, we found that young rats had greater synchrony when making the correct spatial choice compared to the incorrect choice. In contrast, no correlation between task performance and theta coherence was observed in aged rats. These results indicate that aged rats may rely less on hippocampal-prefrontal circuits during complex spatial navigation and instead engage alternative pathways for task completion, or alternatively, may use oscillations at different frequencies to synchronize between these regions.
• Solutions to Water Issues on Navajo Nation: Groundwater Treatment and Water Reuse

  Karanikola, Vasiliki; Yazzie, Christopher B.; Ogden, Kimberly L.; De Vore, Cherie (The University of Arizona., 2025)

  Water scarcity and groundwater contamination continue to be significant challenges for Indigenous communities in the United States, especially within the Navajo Nation. There, legacies of mining, underinvestment in infrastructure, geographic isolation, and water injustice have exacerbated water insecurity. Finding a solution to provide clean, economically safe drinking water to the approximately 40,000 residents of the Navajo Nation without modern water access exemplifies a "wicked problem." This dissertation seeks to shed light on ways to help mitigate the “wicked” water issue in the Navajo Nation. It explores site-specific and technologically feasible solutions to address groundwater contamination and wastewater reuse opportunities in the Navajo Nation through applied environmental engineering and membrane-based treatment processes. This dissertation, structured into one literature review chapter and three research chapters, begins with an assessment of groundwater chemistry in selected water sources across the Navajo Nation (Chapter 2). By utilizing geochemical modeling, the study characterizes the profiles of arsenic and uranium contaminants while evaluating practical remediation technologies. This analysis incorporates hazardous waste management and economic feasibility, providing recommendations for the implementation of localized treatment systems. Chapter three investigates uranium rejection using commercially available nanofiltration membranes in environmentally relevant conditions. Experimental results illuminate fundamental mechanisms of uranium rejection and illustrate how ionic composition impacts uranium speciation, adsorption phenomena, and membrane selectivity. This provides critical insights into the physicochemical interactions that govern uranium removal in realistic water matrices. Chapter four examines advanced treatment of secondary wastewater effluent from facultative lagoons through integrated microfiltration and nanofiltration processes. Comprehensive water quality and microbiological analyses show that nanofiltration-treated effluent meets federal and state agricultural reuse standards. The study demonstrates the effectiveness of a microfiltration and nanofiltration treatment system in eliminating pathogens, regulated contaminants, and contaminants of emerging concern. The findings presented in this dissertation provide an integrated framework for enhancing water access and quality in the Navajo Nation through evidence-based treatment selection, cost-effective engineering design, and alignment with local conditions. This research contributes to the advancement of sustainable water infrastructure and environmental justice for the Navajo Nation and other underserved communities facing water challenges globally.
• 3D Digital Twin for Dynamic Rock Movement Visualization at the SX Mine Using Virtual Reality

  Anani, Angelina; Akbulut, Nilufer Blanche; Wetherell, Meaghan; Momayez, Moe; Kemeny, John; Brown, Leonard (The University of Arizona., 2025)

  Ground stability is crucial in underground mining, as rock mass displacement can lead to failures like ground falls, a major cause of fatalities. Traditional predictive models struggle to accurately forecast displacement, making real-time monitoring essential. However, managing vast amounts of geotechnical data presents challenges. Even though challenges exist around assessing rock mass conditions for ground fall, there are no systematic approaches to implementing real-time monitoring, nor are there technologies being developed that save engineers’ and workers’ time. This dissertation introduces a digital twin (DT) that provides a dynamic three-dimensional (3D) representation of underground mine openings that employs scientific visualizations and immersive analytics (IA) in virtual reality (VR). The overall goal of the dissertation is to provide an effective and efficient communication tool for underground safety concerns surrounding rock movement caused by displacement. The ability to communicate safety promptly allows for the mitigation of accidents and fatalities and allows for the right action to be taken. A monitoring framework with near-real-time visualization is developed and implemented at the San Xavier Underground Mine Laboratory (SX mine). Rock displacement data is collected using a proposed monitoring framework and transferred to a 3D DT in near-real time and visualized as a Trigger Action and Response Plan (TARP) level heatmap. This approach improves spatial analysis, enhances implementations of TARP protocols, and supports better geotechnical decision-making, all while increasing operational efficiency. The geotechnical DT was developed by following the proposed monitoring framework and standards set by DT industry experts, enabling near-real-time data flow to feed the visualizations. The scientific visualizations were developed as a displacement heatmap on the surface of a 3D model to be analyzed intuitively and competently. Finally, to fully utilize the 3D visualization, the DT is implemented into a VR platform where a user can immerse themselves in the 3D visualization. A structured monitoring framework is proposed to address the lack of standardized guidelines for DTs, visual analytics (VA), and VR in underground mining. Implemented at the SX mine using Unity, this cost-effective DT demonstrates the potential of advanced visualization technologies to improve mine safety, ground support design, and geotechnical analysis.
• Furthering Optical Techniques for Micro-Endoscope Development: The Cell-Acquiring Fallopian Endoscope for Early Detection of Ovarian Cancer

  Barton, Jennifer K.; Galvez, Dominique; Hua, Hong; Kang, Dongkyun; Heusinkveld, John M. (The University of Arizona., 2025)

  This dissertation discusses the efforts made to advance the field of submillimeter microendoscopy, with emphasis on detection of early signs of ovarian cancer in the fallopian tubes. The dissertation begins with the medical and technical background knowledge necessary to understand the motivation for building submillimeter diameter endoscopes and introduces the Cell-Acquiring Fallopian Endoscope (CAFE) as a potential screening method for early ovarian cancer. The CAFE is a coherent fiber bundle-based submillimeter endoscope capable of reflectance and fluorescence imaging, as well as cell collection. The reasoning behind many of the optical and mechanical design decisions made is provided.The dissertation contains details on three projects, with details in appendices, undertaken to support a microendoscope approach to early ovarian cancer detection. The first project is the overall design of the CAFE. A manuscript ready for submission describes its working principles and as-built performance, including initial human test data. The endoscope has proven capable of imaging at the desired resolution, illuminating and collecting reflectance and fluorescence images, and collecting an adequate number of cells for analysis. Detailed standard operating procedures for building, testing and operating the CAFE are included. The second project explores the optical limitations imposed on submillimeter endoscopes for small lumens, and a 3D-printed approach to distal objective microlenses. We characterize and compare the performance of a custom gradient refractive index (GRIN) rod lens, a 3D-printed monolithic doublet, and a 3D-printed monolithic triplet. The 3D-printed doublet’s performance had the largest margin of success, but due to low manufacturing yield, the GRIN lens was deemed best to address the needs of a submillimeter endoscope. A manuscript published in the Journal of Optical Microsystems is provided, along with supplementary material. The third project description describes the theoretical modulation transfer function of a coherent fiber bundle-based endoscope, including the effects of a distal lens, fiber bundle, relay lens group, and camera sensor. Experimental results from four configurations are compared to theory, showing that the simulated model is accurate in describing the trend of the modulation transfer equation of a fiber bundle-based endoscope. A software package that takes user input and implements the theoretical equation is also described and shared. A manuscript prepared for publication is included in this dissertation. The dissertation ends with a discussion of planned and potential future work. First, this section summarizes the CAFE’s in vivo study procedure for 10 patients. Then, this section reviews the assembly challenges of the CAFE, the attempts to address those challenges, and the final design for in vivo use. Lastly, it discusses the opportunities for design improvements in the distal lens and ferrule.
• A SmallSat Approach to Deep-Space Exploration: The Enceladus Chirp Orbiter (ECHO)

  Walker, Christopher K.; Henley, Shae Aspen; Larsson, Daniel; Zhupanska, Olesya (The University of Arizona., 2025)

  With the recent advent of commercial space companies, there is increased interest in space exploration and spaceflight technologies. In planetary science, the field of astrobiology is becoming more popular as well. Astrobiologists aim to understand how life developed on Earth, and where habitable environments could exist elsewhere in the solar system and beyond. However, even with all of this interest in space exploration, very few spacecraft have traveled to the outer solar system. This is due to several reasons, but mainly due to the complexities and cost of large missions designed for deep space. Past deep-space missions have tended to be large and expensive; the science returns are incredible, but the price is discouraging. The Enceladus Chirp Orbiter (ECHO) has been designed to be a small, less-expensive orbiter for deep-space exploration, to shift away from the paradigm of large, heavy, and costly deep-space flagship missions. The main science goal of this mission is to use a novel chirp radar experiment (DARE, or the Differential Absorption Radar Experiment) to search for biomarkers in the plumes of the Saturnian moon, Enceladus. The work discussed here details a concept study for the ECHO mission. First, the science rationale for this mission will be discussed, as well as how the DARE instrument functions and its planned operations. Second, the spacecraft design and components will be defined. This will be accomplished through analysis of both off-the-shelf and custom hardware and software. Technologies are leveraged from prior NASA deep-space missions, as well as small satellite (SmallSat) missions, especially those flown and tested on the University of Arizona’s low-Earth orbiting CatSat satellite. Third, a deployable K-band communications dish concept based on CatSat technologies and lab work will be discussed. Next, the trajectory analysis for the mission will be explored, leveraging from past missions to Saturn and beyond, as well as an opportune Jupiter gravity assist occurring in the late 2030’s and early 2040’s. Lastly, ongoing CatSat and LunaCat work, as well as future work to advance ECHO and the DARE technology will be discussed.
• Effect of Melt-Domain Size on the Stability of Vapor Films: Implications for Explosive Submarine Volcanic Eruptions

  Moitra, Pranabendu; Fulton, Rebecca Sophie; Malik, Ananya; McGuire, Luke (The University of Arizona., 2025)

  The explosivity of eruptions in the presence of external water is determined by its thermodynamic interactions with magma. Critical parameters governing an energetic magma-water interaction include the duration of water boiling regimes and the associated rate of heat transfer from magma to the water. A range of melt fragments from micron to cm-size are commonly observed during such interactions. Therefore, the melt domain- or fragment-sizes, at a given melt-water mass ratio, likely provide a first-order control on the efficiency of magma-water interactions but has remained poorly constrained. Comparing high-temperature experimental results with milimeter-scale melt domains to the existing studies with centimeter-size domains, this study provides insights into the effect of fragment size on water boiling regimes. Spherical samples of re-melted mafic rocks with an initial temperature of ~1388 K (1115 ºC) were submerged in water. The temperature of the water was varied in the range of 276-365 K (3-92 ºC) between experiments but was kept constant during any given experiment. The experimental videos were captured using high-speed cameras from where the time scales of water boiling regimes were determined. Our experimental results show that mm-scale melt fragments are associated with shorter vapor film timescales compared to cm-sizes, where this difference increases with increasing water temperature. Using the stable vapor film time scales from the experiments and heat transfer modeling, the Leidenfrost temperatures were estimated. The time scales of stable vapor films provide constraints on the time available for mixing between melt and water along with any external trigger that may be required for energetic melt-water interactions and explosive submarine volcanic eruptions.

View more