• A Comparative Study of Broadcast and Print Coverage in Three Criminal Cases

      Hudson, Lisa Rae (The University of Arizona., Not availa)
    • Liberation: The Story of a French Daily

      Herrera Cruz, Ignacio (The University of Arizona., Not availa)
    • A Structured Approach to Training Text Messaging in an Individual with Aphasia

      Fein, Mira (The University of Arizona., 2018)
      Background: Text messaging is an increasingly common communication modality that can present considerable challenges to individuals with aphasia. Not only does “texting” rely on central (linguistic) and peripheral (sensorimotor) abilities, it requires unique procedural and pragmatic skills. Aim: The purpose of this study was to develop and evaluate a structured treatment protocol to promote mastery of communication via text messaging in an individual with aphasia. Methods: This exploratory study with a 72 year-old woman with anomic aphasia and mild limb apraxia extended language treatment to target technical and pragmatic skills for mobile phone use. Beginning three years post stroke, she received a three-phase training sequence that first addressed single-word typing on her mobile phone, followed by script training for text messages, and finally conversational skills for initiating and responding to text messages. Results: Despite some residual language and visual processing impairments, the participant developed functional text messaging abilities at the word, script, and conversational levels. She demonstrated generalization of skills to novel content and situations, and maintained her text-messaging abilities one year post-treatment. Conclusions: The treatment protocol to retrain text messaging skills in an individual with aphasia yielded strong positive outcomes, warranting further examination in other suitable individuals.
    • Liquefaction of the Brain Following Stroke Shares Multiple Characteristics with Atherosclerosis and Mediates Secondary Neurodegeneration in an Osteopontin-Dependent Mechanism

      Chung, Amanda (The University of Arizona., 2018)
      The response to ischemic injury in the brain is different to the response to ischemic injury in other organs and tissues. Almost exclusive to the brain, and for unknown reasons, dead tissue liquefies in response to ischemia by the process of liquefactive necrosis. However, the data we present here indicate that at the macroscopic, microscopic, and molecular level, liquefactive necrosis strongly resembles atherosclerosis. We show that chronic stroke infarcts contain foamy macrophages, cholesterol crystals, high levels of osteopontin and matrix metalloproteases, and a similar cytokine profile to atherosclerosis. Crystalline cholesterol is a principal driver of atherosclerosis, and because cholesterol is an important structural component of myelin, we propose that liquefactive necrosis in response to stroke is caused by an inflammatory response to myelin debris, and is exacerbated by the formation of cholesterol crystals within macrophages. We propose that this leads to the chronic production of high levels of proteases, which in a partially osteopontin-dependent mechanism, causes secondary neurodegeneration and encephalomalacia of the surrounding tissue. In support of this, we show that genetically ablating osteopontin substantially reduces the production of degradative enzymes following stroke, reduces secondary neurodegeneration, and improves recovery. These findings suggest that treatments that prevent or target the regression of atherosclerosis may also be useful for mitigating the harmful effects of liquefactive necrosis following stroke.
    • Linking Net Assimilation with Multispectral Vegetation Classification to Understand Mesquite-Grass Response to Fire

      Sutter, Leland Frederic (The University of Arizona., 2018)
      Understanding vegetation dynamics across space and time has been a grand challenge in Earth sciences, but the induction of remote sensing products has made large-scale mapping of vegetation possible. We initially used Landsat satellites (30 m; eight-day return interval) to assess the Sawmill Fire of 2017 within the Santa Rita Experimental Range. Because of the spatial and temporal decoupling associated with this remote sensing product, important, but smaller-scale disturbances may not be properly captured; this prompted the use of finer scaled data. As such, we used an unmanned aerial vehicle (UAV) equipped with a five band Micasense RedEdge camera for derived land classification and scaling. Additionally, we measured leaf level net assimilated photosynthesis (ANET) to quantify plant function. We repeated the measurements at three points in time at a control and burned site. Spectrally, changes in the Relative Normalized Burn Ratio (RNBR) using Landsat images from directly before the fire and then after the growing season showed minimal evidence of the fire because of its spatial scale, though there were significant impacts from the fire on vegetative physiognomy and ecosystem function. Classifications built from the multispectral camera showed an overall accuracy of 0.89. This study shows the need for fine-resolution data from newly available UAV systems for practical land management practices. Low altitude, fine resolution data, combined with ecophysiological datasets, can be used to quantify and follow tractable land cover changes not captured by our traditional, lower resolution remote sensing sensors and derived products.
    • The Pathophysiology of Chronic Stroke Infarcts: What Happens After Brain Tissue Dies?

      Likens, Jacob Andrew (The University of Arizona., 2018)
      A stroke can occur when blood flow to a specific area of the brain is interrupted. There has been extensive research in both animal models and humans that has characterized the pathophysiology of the first few weeks following stroke. However, there has been far less research into the chronic stage of infarction. This is an important area for research because more than 10 million individuals worldwide suffer a stroke each year. Approximately one-third of these survivors develop dementia in the first year after their stroke. The cause behind this dementia is currently unclear, and there are no neuro-protective drugs that can improve recovery and provide cognitive protection in the chronic time period. Therefore, the chronic stage of stroke recovery is a promising target for future therapeutics for stroke-related dementia and, as will be shown later in the paper, Alzheimer’s disease as there are likely to be neurodegenerative processes that proceed for months following stroke. The goal of this thesis is to provide a review of what is currently known about the pathophysiology of chronic stroke infarcts (an area of brain tissue that has necrotized due to a blockage in an artery in the brain causing a lack of oxygen), explain why so little is known, and how we can learn more, and provide potential mechanistic links between the response to dead brain tissue and the development of dementia.
    • Mapping Saguaro Cacti Using Digital Aerial Imagery in Saguaro National Park

      Carter, Forest (The University of Arizona., 2018)
      The saguaro cactus has been the subject of extensive ecological research since the establishment of Saguaro National Monument in 1933. Saguaro mapping and monitoring has always been limited in extent due to inherent restrictions of in situ field methods. This research developed a method for automated mapping of mature saguaros over large extents using fine spatial resolution digital aerial imagery. Saguaro shadow signatures were identified using a novel contrasting custom search kernel method. The shadows detected were used as proxies for mature saguaro locations. This research focused on (1) the development of a method of automatically identifying saguaros using their shadows in aerial imagery, (2) applying the method to aerial imagery of Saguaro National Park (SNP) to conduct a large extent saguaro census, (3) validation of the saguaro distributions against in situ field measurements, (4) investigating causes of shadow omissions, (5) estimating total saguaro densities and populations in SNP. The shadow method developed identified 446,092 saguaros across 231 square kilometers in Saguaro National Park. These results were found to be highly correlated (R2 value of 0.966) with saguaro locations recorded by SNP staff in 11 field plots in 2011. This study demonstrates that mature saguaros can be reliably mapped automatically using digital aerial imagery. The method developed will facilitate saguaro monitoring and ecological resource management in SNP and throughout the range of the saguaro cactus.
    • Actigraphy-Assessed Sleep Efficiency is Associated with Ambulatory Blood Pressure in a Community Sample

      Doyle, Caroline Y. (The University of Arizona., 2018)
      Objective: Epidemiological data increasingly supports sleep as a determinant of cardiovascular disease risk. Fewer studies have investigated the mechanisms underlying this relationship or employed objective sleep assessment approaches to discern the CVD impact of specific sleep characteristics. The aim of this study was to examine associations between objectively assessed sleep duration and efficiency and daily blood pressure as a potential atherogenic pathway. Methods: A diverse community sample of 300 men and women ages 21-70, enrolled in the North Texas Heart Study participated in the study. Actigraphy assessed sleep was monitored over 2 consecutive nights with ambulatory blood pressure sampled randomly within 45-min blocks on the first and second day and second night. Results: Complete data was available for 216 participants. As predicted, individuals with lower mean sleep efficiency had higher daytime (systolic: B=-0.241, SE=0.100, p<.017, adjusted R2 =0.412; diastolic: B=-0.121, SE=0.06, p<.045, adjusted R2 =0.356) and nighttime BP (systolic: B= -0.696, SE=0.174, p<.001, adjusted R2 = .243; diastolic: B= -0.410, SE= 0.093, p<.001, adjusted R2 = .230). Moreover, lower sleep efficiency on one night was associated with higher systolic (B= -0.386, SE= 0.111, p<.001, adjusted R2 =0.325) but not diastolic BP (B= -0.126, SE= 0.067, p=.062, adjusted R2 = .223) the following day. Overall, sleep duration was associated with systolic BP only, with the exception of nighttime BP. Conclusions: Objectively assessed sleep efficiency and duration are associated with both concurrent nighttime BP and subsequent day BP and may serve as pathways linking sleep to CVD.
    • Crust and Lithospheric Melting Under Plateaus: A Petrologic and Geochemical Pilot Study of Pliocene Volcanic Rocks West of Lake Titicaca (Southern Peru)

      Campbell, James Hugh (The University of Arizona., 2018)
      Volcanic rocks of the Pliocene Barroso formation in southern Peru were collected for a preliminary petrologic study. These volcanic rocks are typically found as aerially extensive 5-25 meter thick lava flows immediately west of Lake Titicaca and are interlayered with sedimentary continental and lacustrine deposits. Regionally, they represent the latest volcanic products in an area where various forms of subduction-related magmatism have generated distinct arc segments since the Cretaceous. Barroso flows are more mafic than previous volcanic products and formed at a time when the main arc was being formed significantly inboard; consequently, it is plausible that they are formed because of secondary processes operating on the plateau and not the main slab dehydration-related melting above the slab. On a TAS diagram the samples are high-K calc-alkaline series while some are shoshonitic and range from trachyte to basaltic trachyandesite. They are mafic to intermediate in silica concentration and have relatively high concentrations of MgO (<7%) and FeO (<9%). Trace elemental concentrations are indicative of a near-adakitic composition. Overall, these petrographic and geochemical characteristics are like other relatively small volume magmatic products found elsewhere on the plateau near local “bobber-type” basins (Ducea et al., 2013; Murray et. al., 2015) and where magmatism was interpreted to be triggered by small scale delamination events or heating overthickened crust. Thermodynamic forward modeling using major element composition suggest that these rocks were generated at pressure/temperature conditions corresponding to the lower part of the lithosphere, perhaps including the lowermost crust. The most likely source rocks are peridotites mixed with various pyroxenite-rich cumulates pre-existent in the crust (also found as rare xenoliths in some Barroso lavas). We speculate that these dense assemblages provide the negative buoyancy responsible for the topographic low represented by Lake Titicaca. The basin will presumably invert when the dense anomaly will detach and founder in the mantle.
    • Municipal Risk and Time Preferences in Western Water Transactions

      Isaaks, Rowan Mansi (The University of Arizona., 2018)
      Markets for water rights have the potential to increase allocative efficiency of perhaps the scarcest natural resource in the western United States. Due to several features of markets in the region, they are best modeled by game theory. The Rubinstein Bargaining Model can be appropriately adapted to the case of bilateral negotiations for water rights, and predicts that the time preferences of players impact the outcome. It is also possible to model the effect of risk and municipal risk preferences relating to the available supply of water, which microeconomic theory predicts will also affect outcomes. While previous literature has written about various determinants of water market outcomes, little attention has been paid to the empirical measurement and testing of the effect of time preferences and risk in these markets. In this thesis, I attempt to bridge this gap between the theory and empirical analyses by testing theoretical predictions using both a well-known data set and a novel one. I find moderate evidence suggesting that a greater time preference results in a less favorable outcome, and that buyer risk-aversion is a disadvantage in bargaining when risk is present.
    • Points of View: Landscape Persistence in Northeastern, AZ

      Soza, Danielle Renae (The University of Arizona., 2018)
      This thesis investigates the processes of place-making at Rock Art Ranch, northeastern Arizona from the Paleoindian period to early agricultural Basketmaker II period (11,500 BCE-600 CE) using the surface distributions of projectile points. Three major canyons cross-cut the ranch providing ample water resources that can be exploited year-round through natural springs, groundwater, and seasonal pools, attracting fauna and providing a diverse range of floral resources. Resources at Rock Art Ranch also include two cobble outcrops, providing raw material for stone tool manufacture. Additionally, thousands of petroglyphs scale the walls of Chevelon Canyon, ranging from Archaic to Pueblo styles. The sample of 162 preceramic projectile points are mostly found close to the canyons. Paleoindian, early Archaic, and middle Archaic projectile points are concentrated around Bell Cow Canyon. Projectile points made by semi-sedentary groups of the late Archaic and Basketmaker II periods occur more often around Chimney Canyon, demonstrating a shift in settlement. Projectile points dating from earlier periods are often associated with pithouse and pueblo sites, suggesting curation practices and active engagement with these materials. Continued use of the landscape seen in the discard of projectile points indicates that RAR was an important area for procurement of resources such as water, plant and animal foods, and lithic material. Evidence of discard and engagement with the artifacts and features from older occupations suggest that their cultural memories tied to this place were associated with the resources found there, but that memory of the place was reinforced by the archaeological record
    • Assessing the Feasibility of Using a Sealed Landfill for Agricultural Graze Land

      Hard, Hanna R. (The University of Arizona., 2018)
      The average American produces approximately 4 pounds of trash per day, approximately 55% of which is buried in municipal solid waste landfills. Once full, these landfills are closed, sealed, and maintained according to the United States Environmental Protection Agency’s standards and regulations, and then monitored or remediated as necessary. There is great interest in putting closed landfills to some sort of productive use—particularly via agricultural activities. This project was commissioned by the City of Tucson Environmental Services Department as a part of an effort to explore ways to reuse one or more of the 16 landfills it manages in the Tucson metropolitan area. The objective of this project was to assess the feasibility of using a closed and sealed landfill to support safe goat browsing. A site investigation was conducted at the Harrison Landfill in Tucson, Arizona to assess the site’s history and to characterize the soil quality and uptake of deleterious metals by the following plants commonly observed at the landfill: buffel grass (Pennisetum ciliare), desert broom (Baccharis sarothroides), Russian thistle (Salsola kali L.), creosote (Larrea tridentata), salt cedar (Tamarix ramosissima), and four-wing salt brush (Atriplex canescens). Site characterization data were combined with goat browsing and plant consumption patterns to determine exposure risks. It was observed that soil concentrations of metals (Al, Ag, As, Be, Ba, Fe, Co, Cu, Cr, Cd, Fe, Mn, Ni, V, Se, Mo, Sn, Sb, Pb) did not exceed Arizona Department of Environmental Quality’s soil remediation standards. Furthermore, salt cedar, willow baccharis, buffel grass, Russian thistle, desert broom, creosote, and four-wing saltbush contained metal concentrations that fell well within maximum tolerable levels (MTLs). This project determined that, after soil and plant assessment, urban, arid landfills in general may be safely used for economic development through agricultural grazing ventures.
    • Shared-Parameter Joint Models of Fatigue and Time until Death of Non-Resectable Lung Cancer Patients

      Phillips, David A. (The University of Arizona., 2018)
      With researchers showing greater interest in the relationship between longitudinal and survival outcomes, joint models are being used with greater frequency. Joint models of longitudinal and time to event outcomes offer distinct advantages. First, joint models can reduce bias in estimates of the relationship between surrogate markers and survival endpoints. Second, this class of model can provide sensitivity analysis of longitudinal estimates in the presence of potential missing data when the longitudinal outcome and survival outcome are related. The aim of this paper is to demonstrate the usefulness of this methodology when dealing with potentially related outcomes. Using a data set from a clinical trial aimed at reducing fatigue with physical activity amongst non-resectable lung cancer patients, several joint models and conventional models such as a linear mixed model and Cox proportional hazards model were generated. Both the longitudinal and survival estimates from these models were compared to demonstrate the utility of joint models. Furthermore, the implementation of joint models is discussed as a result of the analysis.
    • How Connected Is Connected? Structural Measures to Estimate Effective Conductivity

      Klakovich, Jeffrey Vincent (The University of Arizona., 2018)
      Connectivity has been a target of investigation for subsurface hydrology for decades. We apply seven new and existing connectivity measures to 2-D, binary hydraulic conductivity (K) grids that include a range of percent high K mixtures. Effective conductivity (Keff) for 1-D flow through the domain is calculated from the results of flow simulation (MODFLOW) and compared with connectivity measures. In addition, characteristics of the percolating network (connected high K bodies that span entire domain) are investigated. Results indicate that most of the range of Keff (80%-90%) for approximately 1 million randomly generated grids over a range of percent high K mixtures only exists among percolating grids. We demonstrate that the number of unique percolating paths (NPP) is the most important structural feature for predicting Keff. We show that NPP can explain to a large degree the mean behavior of Keff as a function of percent high K material. It may also explain the variance of Keff as a function of percent high K, however this has not been shown conclusively. Most connectivity measures were not found to correlate with Keff. In general, it seems connectivity is only important for Keff when high and low K values are similar (one order of magnitude different). Therefore, the overall impact of connectivity is relatively small. The dependence of Keff on the continuity of high K paths suggests that methods that return volume-averaged properties (e.g. electrical resistivity tomography) may have limited ability to predict Keff. High resolution imagery or water isotopic tracer tests to infer structure may be necessary for accurate estimation of Keff.
    • Predicting the Size and Location of a Cavity in a Solid Half-Space from the Scattered Ultrasonic Fields Using Genetic Algorithms

      Alnuaimi, Hamad (The University of Arizona., 2018)
      Genetic algorithms are used to predict the size and location of an elliptical cavity within a solid half-space. The scattering of ultrasonic waves in the solid half-space with a cavity is modeled using Distributed Point Source Method (DPSM). DPSM which is a semi-analytical technique that utilizes Green’s function is used for modeling because this technique is more efficient than popular but not so efficient Finite Element Method (FEM). FEM is very inefficient for modeling ultrasonic wave propagation problems at high frequencies and for solving an inverse problem one needs an algorithm that can solve the forward problem efficiently. The inverse problem is solved by applying a genetic algorithm to the forward problem to determine the optimum solution. The optimum population size and number of generations are determined. Results and analysis are performed for 3 cases of unknown variables.
    • Forensic Rockfall Dating at Kartchner Caverns

      Bates, Melissa Elizabeth (The University of Arizona., 2018)
      This study discusses the time dependent nature of geomechanics and explores low-impact methods for dating rockfalls in the cave environment. Kartchner Caverns provides a unique environment to perform this study because of its high humidity, absence of sunlight, gently fluctuating temperature, and seclusion from the above ground surface which causes the cave to be inhabited by specific types microorganisms. High precision microscopy and microbial DNA extraction were used in order to better understand the changes that rock surfaces undergo when they are exposed to the cave environment. Spectral data collection was done in order to research the applicability of remote sensing technology to assess the degree of weathering of rock surfaces at the project site. It was concluded that microbiology and chemical processes may play an important role in weathering in the cave environment and spectral imaging has the potential to be an effective data collection method.
    • Effects of Lactobacillus Reuteri Supplementation on Serum Cholesterol and Cardiac Damage

      Koppinger, Matthew P. (The University of Arizona., 2018)
      Dysbiosis of the gut microbiota has been implicated in the progression and severity of a number of disorders, including cardiovascular disease. Probiotics offer a means to positively manipulate the gut microbiota and can improve cardiovascular risk factors, like hypertension and hypercholesterolemia. Research investigating the effects of probiotic supplementation in the context of cardiac injury is limited. Furthermore, the mechanism by which probiotics impart benefits and where these benefits are incurred in the GI tract is not well elucidated. The aims of this thesis were to investigate the effects of probiotic supplementation in the context of cardiac injury and better understand probiotic localization following administration. In the first study, LDLr KO and wild-type mice were administered Lactobacillus reuteri for 5-6 weeks before initiation of an ischemia/reperfusion protocol. In the second study, transit and localization of the probiotic, Bifidobacterium animalis subspecies lactis 420 (B420), were monitored in the GI tract following single and consecutive administrations. Results of the first study show that supplementation with L. reuteri significantly attenuates cardiac damage following myocardial infarction. The second study found that B420 presence in the GI tract was lost rapidly following cessation of treatment. Together, these results show that probiotic supplementation may offer an alternative therapy for improving cardiac health and that continuous treatment is necessary for probiotics to impart their beneficial effects.
    • The Role of Dissolved Organic Matter on the Mobilization of Arsenic from a Legacy Mine Tailings Site

      Bozeman, Lauren R. (The University of Arizona., 2018)
      Legacy mine sites are of concern due to their prevalence and associated environmental and human health risks. The United States Bureau of Land Management estimates as many as 500,000 abandoned mine sites in the US (BLM, 2017). Sites requiring costly management and long-term response to the environmental hazardous risks can be designated to a National Priority List (NPL) by the Environmental Protection Agency (EPA) under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) (EPA, 2017). One such site, located in Central Arizona, is the Iron King Mine Humboldt Smelter Superfund Site (IKMHSSS). The site was designated to the NPL in 2008 due to concerns regarding the size of the tailing pile, the proximity of contaminated materials to the town of Dewey-Humboldt and waterways, and the dangerous concentrations of arsenic (As) and lead (Pb) of the tailings (EPA, 2017). Remediation efforts have been ongoing since the designation of the site to the NPL, including sampling, yard soil removal, and distribution of information to the local community regarding risks from the site. The University of Arizona Superfund Research Program (UA SRP) has conducted greenhouse and phytostabilization studies of the site in an attempt to understand the processes and mechanisms employed to stabilize the tailings materials as well as reduce dust emissions from the tailings to the town of Dewey-Humboldt (Gil-Loaiza et al., 2016). This effort has successfully demonstrated a reduction of dust emissions (Sáez, 2016), however chemical changes to the tailings due to phytostabilization are the focus of this research. This work attempts to ascertain whether adverse effects from the method of phytostabilization are observed in the pore waters of the tailing material, in particular the potential for contamination of water sources by mobilized As through chemical or microbiological means. Recent studies have proposed potential mechanisms that can promote mobilization of As by dissolved organic matter (DOM) (Mladenov et al., 2015). Heterotrophic microbial respiration under O2 limited conditions can cause the reduction of Fe3+ to Fe2+, enhancing desorption or dissolution of As from Fe containing minerals (Hasan et al., 2007). Additionally, DOM competes with As for sorption sites at mineral surfaces (Grafe et al., 2002). In this study, batch and column experiments were used to investigate the mechanisms of sequestration and release of As in compost amended mine tailings. Mine tailings were reacted in triplicate in the presence and absence of DOM using plain tailings and radiated tailings for microbiological control and under anoxic and oxic conditions at timescales from ranging from 3 to 900 hours for batch experiments and 1 to 900 pore volumes in column experiments. The highest As release to pore waters was observed under anoxic conditions in the presence of DOM both with microbial activity inhibited and uninhibited through 60Co gamma irradiation after 3 and 910 h of reaction. The release of As from batch experiments was lowest in the control treatment with no DOM added to tailings in both anoxic and oxic treatments after 24 h. Column flow-through experiments were also carried out to better understand the kinetic biogeochemistry of the tailings interacting with DOM. Columns were completed under suboxic conditions to best mimic field scenarios. To test the effect of microbes, control tailing samples were sterilized by 60Co gamma irradiation prior to flowing DOM. Pore volumes (PV) were collected using fractionation equipment from 1 to 900 PVs. The release of As was highest in the presence of DOM after approximately 40 PVs when As release began increasing to its maximum release of 50 μmol l-1. No significant difference between irradiated and non-irradiated tailings was observed in either irradiated or non-irradiated tailings. Lowest release of As to effluent solutions was in the absence of DOM. These results were consistent with the findings from batch experiments. Batch and column experiments show that DOM influences the mobilization of As from mine tailings, and demonstrates the potential risk to proximal ground water resources in the absence of attenuation processes between the oxidized tailings and groundwater.
    • Sensitizing Human Cancer Cells Through the Inhibition of NSMCE2

      Alassady, Hanen Assad (The University of Arizona., 2018)
      Homologous recombination (HR) is a high-fidelity DNA repair pathway that is activated mainly by replication-associated DNA damage. DNA damaging agents that cause double strand breaks (DSBs) at the replication fork can be repaired by HR. NSMCE2, an E3 sumo ligase, regulates HR at damaged replication forks. NSMCE2, complexed with the structural maintenance of chromosomes (SMC) 5/6 complex, stimulates the SUMOylation of the SMC6 coiled-coil region, thus mediating HR. Cancers that have defects in their HR machinery are susceptible to chemotherapies that elicit DNA damage, and in particular, damage that affects DNA replication. Targeting regulators of HR could therefore sensitize HR-proficient cancers to standard therapies. We used in-silico protein modeling to generate a 3D model of the human NSMCE2 protein. We identified a deep pocket in NSMCE2 that is adjacent to an active-site zinc-binding region and twelve compounds that potentially could occupy that pocket. We sought to determine whether any of these compounds could inhibit NSMCE2 activity or function. We screened the compounds in the human osteosarcoma cell line (U2OS) for synergistic inhibition of cellular proliferation by the topoisomerase 1 inhibitor, camptothecin, and identified four that caused no cellular toxicity on their own whereas they were synergistic with camptothecin in limiting cell proliferation. One of the compounds, compound 3, showed a twelve-fold increase in inhibition of cellular proliferation in combination with camptothecin. We also were able to determine compound specificity to NSMCE2 using a mutation in HEK293T cells. We concluded using small molecule inhibitors of NSMCE2 could be useful in enhancing chemotherapy-mediated killing of HR-proficient cancer cells. Development of NSMCE2 inhibitors could also lead to adjuvant therapies that would allow for patients to receive lower doses of toxic topoisomerase poisons.