Now showing items 1-20 of 64117

    • Exploring the Relationship Between Accreditation and For-Profit Higher Education Institutions

      Parkman, Amanda Lee (The University of Arizona., 2018)
      This paper explores the relationship between for-profit higher education institutions and accreditation. Two sets of research questions are examined. The first set of research questions looks at the characteristics of for-profits regionally accredited versus nationally accredited. The second set of research questions looks at the characteristics of for-profits that keep accreditation versus those who lose accreditation. Analysis is conducted using panel longitudinal data that has been merged together from the Integrated Postsecondary Education Data System (IPEDS), the Office of Federal Student Aid, and the Postsecondary Education Participation System (PEPS). Both descriptive statistics and logistic regressions are used to explore the hypotheses in this paper. The findings contribute to the field’s understanding of for-profits and accreditation. This paper found in general for-profits are not losing accreditation. Regionally accreditors in particular are not revoking accreditation. Larger for-profits are more likely to be regionally accredited. Revenue, enrollment, and number of campuses, in particular seem to keep institutions from losing accreditation. Policy continues to be created (or reversed) to address concerns over for-profits but it has done so without enough statistical analysis to backup those decisions. The relationship between for-profits and accreditation is mutually beneficial and therefore needs to be further researched and addressed.
    • Might Recycled Water Inhibit Toxin-Producing Cyanobacteria?

      Lynch, Robert
      Cyanobacteria, or blue-green algae, is a phytoplankton phylum found in surface water bodies worldwide. For decades, blue-green algae has caused severe aesthetic water quality problems and induced water deoxygenation, leading to fish kills and other detrimental outcomes. Furthermore, some cyanobacterial genera, most notably several Microcystis species, are known to produce hepatotoxic peptides known as microcystins. Such toxin production is of critical and increasing public health concern, as hepatotoxic cyanobacterial blooms in freshwater lakes and streams have been implicated in human and animal sickness, and even death. Studies have correlated increased toxin production to enhanced temperature, nutrient concentrations, and light intensity, but research results examining microcystin toxin production in response to environmental stimuli have rarely been conclusive outside of the laboratory or over multiple seasons. Our research implemented advanced molecular techniques (real-time quantitative PCR) to detect and quantify cyanobacterial genes (CYAN) and toxin synthetase genes (mcyD) in water samples collected from a recycled water retention pond and a groundwater-filled pond. Water samples also underwent chemical and physical analyses to identify factors correlating to decreased toxin synthesis. Our results show similar concentrations of CYAN in both ponds but lower concentrations (sometimes below limits of detection) of mcyD levels in the recycled water retention pond. LC-MSMS showed average toxin concentrations of 6.702 ± 0.067 µg L-1 in the groundwater-filled pond while toxins were undetectable (detection limit ≥ 3 ppt) in the recycled water retention pond. Levels of mcyD in the groundwater pond were negatively correlated (p ≤ 0.05) with Cr52, a find that has been paralleled in previous research. Concentrations of Fe56 were significantly lower in the groundwater pond (p ≤ 0.05), suggesting iron-limitation may have been a contributing factor to microcystin-biosynthesis. Knowledge of the regulation of microcystin toxin biosynthesis may facilitate implementation of water management strategies to avoid environmental conditions that induce dangerous water quality conditions.
    • Novel Pad Conditioning and Slurry Dispense Methods in Chemical Mechanical Planarization

      Stuffle, Calliandra (The University of Arizona., 2018)
      The first part of this study investigates the pad surface generated by conditioning with three different CVD-coated diamond discs and the corollary effect on polishing performance in copper CMP. The discs that were used had significantly different micro-structures with varying degrees of aggressiveness. Confocal microscopy was used to study the pad surface after the polishing experiments had been performed, where the contact area, contact density and surface topography were analyzed. The most aggressive disc generated a pad surface with the most contact area, contact density and the tallest asperities. These parameters decreased as the aggressiveness of the disc decreased. Thermal, tribological, and kinetic aspects of copper polishing were also investigated. The pad surface generated by the most aggressive disc produced the highest material removal rates. However, the pad surface generated by the least aggressive disc produced a slightly elevated coefficient of friction and mean pad temperature when compared to the other pad surfaces, most likely due to fluid suction caused by the glazed pad surface. Analysis of the chemical and mechanical rate constants indicated that this process was chemically limited for all P × V investigated. The second part of this study analyzed the thermal, tribological and kinetic aspects of the new and developing area of cobalt “buff step” CMP. A process-specific combination of consumables and polishing settings were used to investigate the removal of silicon dioxide in order to better characterize the second step of cobalt polishing in middle of the line (MOL) applications, where the overburden of deposited cobalt had already been polished away, and residual cobalt, along with the liner, needed to be completely removed. This was realized by polishing some of the surrounding dielectric in the “buff step”. Our study showed that the removal rate of the oxide and the mean pad temperature increased with increasing P × V, while the coefficient of friction remained relatively constant, indicating a “boundary lubrication” tribological mechanism. A well-established modified two-step Langmuir-Hinshelwood model was used, for the first time for this set of consumables, to simulate the removal rate data, which yielded chemical and mechanical rate constants. These results indicated that the process was mechanically limited for almost all polishing parameters investigated, except for the most elevated P × V. The final part of this study continued work on the cobalt “buff step” for MOL applications by investigating the use of a novel slurry injection system (SIS) developed by our research group. The tests compared the effect of using the SIS versus the point application (PA) method for three different slurry flow rates at constant pressure and velocity. Higher silicon dioxide removal rates were realized by using the SIS for each flow rate, in comparison to those generated by the PA method. For both methods, the removal rate and coefficient of friction increased with increasing flow rate, while the mean pad temperature remained relatively constant. Similar removal rates were measured for the SIS versus PA at different flow rates, indicating that a 25 to 33% reduction in slurry consumption could be realized by implementing the SIS. A subtle yet critical change was made to the two-step Langmuir-Hinshelwood to account for the chemical effects of fresh slurry dilution by residual rinse water and spent slurry. A nearly three-fold reduction in the root mean squared error between the experimental and simulated removal rates was achieved by addressing these chemical effects, while leaving all other optimized parameters constant from the successful simulation of the removal rate data from part two of this study which used the same set of consumables but one constant flow rate and PA method.
    • Causes of Organ Rejection in Kidney Transplantation and a New Proposed Strategy to Improve Survival of the Graft

      Abdelhabib, Mohamed (The University of Arizona., 2018)
      The kidney is an essential organ that serves a crucial role in preserving homeostasis by filtering blood, regulating fluid levels and maintaining acid/base balance. Any extensive damage to the main unit of the kidney, the nephron, will cause several complications. There are multiple etiologies of kidney injury and they are classified as either acute or chronic. Acute causes are usually easier to treat and the damage resulting from it can be reversed. However, in chronic cases the injury to the kidney might be too severe to the point that renal replacement therapy is recommended. The two options of kidney replacement available are dialysis and kidney transplant. This review will focus on the complications of kidney transplant and ways to increase survival of the graft. The biggest concern with transplantation is rejection of the organ. Rejection usually happens due to immunological response against the graft. That is why pre-operative measures are taken to try to match the donor to the recipient as much as possible. The process involves matching major histocompatibility complex (MHC) and blood antigens. These two molecules are the most important in matching as they play a role in the immune response. The function of MHC in the immune system is to present self and foreign antigens to immune cells. Once immune cells are activated against antigens from the graft, rejection can occur.. Organ rejections involves both the innate and adaptive arms of immunity. Nonetheless, the involvement of adaptive immunity in transplant rejection is better understood. With the adaptive immunity, there are two pathways of rejection, direct and indirect. The direct pathway is where immune cells within the graft present antigens to the recipient’s immune cell to initiate the attack. On the other hand, the indirect pathway is where the recipient’s immune cells recognize antigens from the transplanted organs as foreign and activate the immune system to attack the transplanted organ. Since rejection is mostly an immunological process, the current drug therapies suppress the immune system to increase survival of the graft. These drugs target the activation of immune cells and their proliferation. The new strategy for treatment proposed here is to increase survival of the graft through blockade of MHC-I presentation. The proposed method is to target antigen presentation by MHC-I through a mechanism that is similar to the ICP-47 Herpes Simplex Virus protein that inhibits the function of TAP proteins in antigen presentation. Such a strategy would increase survival of the graft by reducing the effects of the direct pathway of rejection.
    • Sex Ratios in Haplodiploid Herbivores (Aleyrodidae and Thysanoptera): A Review and Tools for Study

      Bondy, Elizabeth Canlas (The University of Arizona., 2018)
      Studies confirming adaptive sex allocation, or a flexible relative investment in males and females, have been extensive in Hymenoptera, and have been used to predict the quality of biological control agents, to theorize how eusociality is maintained, and to predict population dynamics. Most hymenopterans are haplodiploid, in which females are derived from fertilized eggs and males from unfertilized eggs, so haplodiploid mothers may have a greater ability to adaptively adjust sex allocation. Thysanoptera and Aleyrodidae are also haplodiploid organisms, many of them being important agricultural pests, but less comprehensive studies on sex allocation have been performed with these taxa. Both taxa are also mostly herbivorous, drawing in new elements that may affect sex allocation patterns. This review is a summary of all studies of Aleyrodidae and Thysanoptera sex ratios as affected by temperature, host plant and nutrition, conspecifics, competitors, bacterial and viral endosymbionts, predators, parasitoids and other pathogens. Sex ratio influences were found in studies testing effects of temperature, host plant, conspecifics, competitors, bacterial endosymbionts and a fungal pathogen. Viruses, predators and parasitoids were not found to affect sex ratios in Aleyrodidae and Thysanoptera, although not many studies have collected the data to assess these potential factors. Because sex ratio studies in Thysanoptera and Aleyrodidae have only recorded secondary, adult or operational sex ratios instead of primary sex ratios, differential developmental mortality is left as a confounding variable, and it is difficult to determine whether sex ratio changes are due to sex allocation. To conclude whether sex allocation of mothers is taking place, the primary sex ratios need to be recorded, so we have also included methods for tools, including cytogenetics and survival assays, to find primary sex ratios or confirm differential developmental mortality in these haplodiploid organisms. Future discoveries of sex allocation in Aleyrodidae and Thysanoptera may lead to better predictions of pest populations.
    • Arizona Agriculture Teachers’ Perceived Self-Efficacy to Teach Science Content

      Parker, Hannah Callahan (The University of Arizona., 2018)
      The purpose of this study was to describe the relationship between sources of science content knowledge and the perceived self-efficacy to teach science content among practicing Arizona agriculture teachers. Bandura’s (1977) theory of self-efficacy was the theoretical framework that guided this study. Sources of science content knowledge were derived from Rice and Kitchel’s (2015) conceptual framework. On average, agriculture teachers were somewhat confident to teach science. A moderate bivariate correlation was found between teachers’ high school agriculture program experience as a youth, current teaching experience, experiences with agriculture jobs and internships, and their self-efficacy to teach science content. A simultaneous multiple regression was implemented; explaining 29% of agriculture teachers’ self-efficacy to teach science content from six of the seven sources of content knowledge. Teaching experience, SBAE, internet and other media, professional development, agriculture related jobs and internships, and years spent teaching contribute to R2. Further research recommendations include applying qualitative methods to explore unexplained variance and identify additional sources of knowledge. Recommendations for practice include exploring content specific professional development opportunities, such as CASE, and encouraging teacher preparation programs to re-evaluate curricula to include science specific PCK to enhance the preparation of preservice teachers.
    • Comparing Different Approaches to the Implementation of a New Chemistry Curriculum

      Hou, Ying (The University of Arizona., 2018)
      In recent years, educational researchers have investigated teacher-student interactions in science classrooms, paying particular attention to interaction patterns and the purpose of such interactions. Although different patterns and purposes have been uncovered through these investigations, there is little research on how college instructors use in-class interactions to help students construct ideas. Instructors' decisions and actions are important when interacting with students and they can be expected to depend on their teaching experience, instructional strategies, and educational purposes when implementing in-class activities. Thus, we have carried out a qualitative study using in-class observations and semi-structured interviews as the main data collection tools to explore the differences in how diverse instructors interact with students during in-class activities in the new “Chemical Thinking” curriculum for General Chemistry at the University of Arizona. The participants of this study included six instructors with different backgrounds and teaching experiences. We identified major types of discourse moves instructors used when interacting with students. Main findings indicate that although participants shared similarities in the interaction patterns and discourse moves they followed in the classroom, they approached the implementation on in-class activities in different ways and their decisions and actions had an impact on the quality of the opportunities to learn that they created. The results of our study are relevant to chemistry educators interested in helping college instructors improve their practice when implementing collaborative group activities in the classroom.
    • The Shared Meaning of Compassion Fatigue among Registered Nurses Working in Skilled Nursing Facilities

      Steinheiser, Marlene (The University of Arizona., 2018)
      Purpose: The purpose of this research study was to describe the shared meaning of compassion fatigue (CF) among registered nurses (RNs) caring for older adults in skilled nursing facilities (SNFs). Background: Nurses who care for older adults in SNFs expend compassion energy when caring for suffering patients, thus increasing the risk their compassion fatigue. In the most commonly used conceptual model of CF, compassion satisfaction is defined as the positive feelings of providing care and the negative feelings from the environment (burnout) and from one’s emotional response (secondary traumatic stress). Symptoms of CF can include physical illness, detachment from patients, work-life imbalance and emotional distress. CF can negatively impact patient outcomes, is associated with decreased quality of care, and can be a reason why nurses leave the profession entirely. Method: The hermeneutic interpretive phenomenology method was used to describe shared meaning of CF among RNs caring for older adults in SNFs. Eight participants were recruited for participation, with the assistance of key nursing leaders and snowball sampling. Each participant was interviewed three times, and concurrent data analysis helped to formulate mutual understanding of the phenomenon while also informing subsequent interviews. Self-reflection, journaling, record keeping, and use of direct quotes enhanced trustworthiness. Findings: The participants (N= 8) described their experiences caring for older adults in a SNF. Four shared meanings were abstracted:1) I feel conflicted and that causes my CF; 2) physical and emotional manifestations of CF; 3) CF is infused in every aspect of my life; 4) We are trying to cope with CF. The participants shared the central desire to make a difference in the lives of their patients, which was of paramount importance. When participants felt they were unable to make the desired difference, they began to develop symptoms of CF. Symptoms were compounded when they experienced the death of patients they felt close to. Implications: A comprehensive resiliency program incorporating individual and organizational involvement could positively impact the participants’ professional quality of life. Future qualitative and quantitative research is needed to better understand CF and effective interventions among this population of nurses.
    • The Role of 14-3-3 Gamma in Promoting Genomic Instability

      Gomes, Cecil (The University of Arizona., 2018)
      The 14-3-3 family members are a group of highly conserved scaffolding proteins that are present in all eukaryotes. Despite having limited endogenous activity, the 14-3-3s bind to numerous client proteins and directly modulate their activities by a variety of mechanisms. In mammals, there are seven isoforms (beta, gamma, epsilon, eta, sigma, theta, and zeta), and between them over 200 known binding partners, which allow them to function in nearly every aspect of cellular biology. The 14-3-3 family has long been studied in regards to cancer, as aberrant changes in their expression patterns have been associated with numerous human cancers. It is, therefore, a shared goal, among many, to elucidate the role of 14-3-3 proteins in tumorigenesis. For the last decade, our laboratory has been keenly focused on the tumor-promoting roles of 14-3-3 proteins in the context of lung cancer, as their expression patterns are highly dysregulated in this cancer setting. Herein, we expand on this area of research and demonstrate that four of the seven 14-3-3 isoforms are significantly elevated in both adenocarcinomas and squamous cell carcinomas of the lung. We then investigated the consequences of these isoforms being increased in malignant lung tissues and showed that when upregulated, 14-3-3 sigma, gamma, and zeta correlate with poorer prognosis in patients with lung adenocarcinoma (LUAD). Interestingly, these associations with survival were not observed in patients with lung squamous cell carcinoma (LUSC), suggesting that the upregulation of these 14-3-3 isoforms may influence patient survival and serve as suitable prognostic biomarkers. To explore the cellular consequences of 14-3-3 upregulation, our laboratory previously overexpressed 14-3-3 gamma, the isoform that demonstrated the strongest prognostic capacity in the LUAD-TCGA dataset, in human lung adenocarcinoma cells. Overexpression of this isoform caused a fraction of cells to become polyploid, meaning they contained more than two sets of chromosomes. Amassing data have demonstrated that polyploid cells are uniquely resistant to chemo- and radiotherapy, making polyploid cells integral components in driving the ongoing evolution of the patient disease and recurrence. We, therefore, became interested in illuminating the molecular mechanism(s) driving 14-3-3 gamma-induced polyploidy, the net effect these cells had on genomic integrity, and whether this phenomenon occurred in vivo. By utilizing the fluorescence ubiquitin cell cycle indicator (FUCCI) system, we were able to show that overexpression of 14-3-3 gamma resulted in inhibition of mitotic entry, forcing some cells to bypass mitosis entirely, thereby facilitating the polyploid phenotype. In pursuit of investigating whether these polyploid cells could re-enter the cell cycle and undergo cell division, we developed a widely-applicable, nontoxic procedure for measuring DNA content in live cells by fluorescence microscopy. This capacity allowed a cell’s temporal location within the cell cycle and its DNA ploidy to be coupled with a variety of imaging directed analyses. By tracking these polyploid cells over time in combination with the nuclear-reporter H2B-GFP, we were able to show that these polyploid cells are capable of entering mitosis, and when they do, they experience a prolonged and error-prone cell division. Collectively, these data demonstrated that the overexpression of 14-3-3 gamma resulted in a genetically unstable polyploid intermediate with the capacity to undergo mitosis and plausibly facilitate the transition into an aneuploid cell state. Equipped with this knowledge, we examined whether this phenomenon occurred in vivo. To do this, we turned back to the TCGA and confirmed that polyploid tumors had significantly elevated expression of 14-3-3 gamma compared to diploid tumors. This data may explain one avenue as to why elevated expression of 14-3-3 gamma correlates with more reduced survival in patients with lung adenocarcinomas. Taken together, our studies suggest that 14-3-3 gamma may play a role in tumorigenesis by inducing polyploidy, which may set the stage for further changes that lead to neoplastic progression.
    • Pattern Generation and Control in Semiconductor Quantum Well Microcavities

      Luk, Ming Ho (The University of Arizona., 2018)
      Many physical phenomena have been observed in semiconductor quantum well microcavities, such as polariton Bose-Einstein condensation, pattern formation, optical spin Hall effect (OSHE), solitons and more. An optically pumped cavity system has the advantage of strong nonlinear couplings between polaritons, and easy detection with photons emitted from the cavity. This thesis presents the theoretical studies of far-field pattern formations, transfer matrix calculations, optical control of the OSHE, and generation of orbital angular momentum (OAM) in optically pumped single- and double-cavities, and comparison with experimental outcomes. This work is a collaboration between theoretical groups at the University of Arizona (USA), Chinese University of Hong Kong (Hong Kong), University of Parderborn (Germany), and an experimental group at CNRS (France). Far-field transverse patterns originates from the nonlinear coupling of polaritons. Patterns, such as 2-spot and hexagon, are observed in optically pumped semiconductor quantum well microcavities when the pumping intensity is above the modulation instability threshold. The first part of this work studies the generation of far-field patterns in an optically pumped semiconductor double quantum well microcavities using a microscopic model of exciton and cavity photon fields, and introduce a simple control mechanism utilizing the light-house effect to control the orientation of 2-spot patterns. Transfer matrix calculations are performed to provide the connection between the microscopic model and the experimental cavity. This work aims to provide simple and robust control mechanisms for future optical communication devices. The second part of this work shows the formation and control of the OSHE in an optically pumped double-cavity. The OSHE is a linear optical effect of exciton polaritons in semiconductor microcavities. It originates from the polaritonic spin-orbit coupling, and can lead to observable spin/polarization textures in the near and far field under appropriate excitation conditions. An alternative description is based on a pseudo-spin model. The formation of the OSHE texture can be described by an effective magnetic field generated by the splitting of the transverse-magnetic and transverse-electric (TE-TM) polariton modes. Here we show theoretically that the orientation of the pseudo-spin texture can be controlled all-optically, which matches the experimental observation. We establish the relation between the incident light intensity and the degree of rotation of the far-field pattern using both the simplified pseudo-spin model and the double-cavity spinor-polariton equations. This scheme provides a simple and robust control mechanism for future spinoptronic devices utilizing OSHE. Potential applications of the orbital angular momentum (OAM) of light range from the next generation of optical communication systems to optical imaging and optical manipulation of particles. In the third part of this work we propose a micron-sized semiconductor source, based on a polaritonic quantum fluid in a single-cavity, that emits light with predefined OAM pairs. We show how modulational instabilities can be controlled and harnessed for the spontaneous formation of OAM pairs not present in the pump source. Once created, the OAM states exhibit exotic flow patterns in the quantum fluid, characterized by generation-annihilation pairs.
    • Explicitly Correlated Gaussian Functions and Rovibrational Spectra of Diatomic Molecules

      Jones, Keith (The University of Arizona., 2018)
      Explicitly correlated Gaussian functions are implemented in order to calculate the rovibrational spectra of various diatomic molecules with and without the Born- Oppenheimer approximation. Matrix elements and gradients for the overlap, potential, and kinetic energy are derived for two different bases corresponding to the second rotationally excited state, one with the approximation that the rotational excitation of the system is due primarily to the excitation of the nuclei and the other allowing all particles to contribute to the rotational excitation. Matrix elements of the nuclear nuclear correlation function and interparticle distance are also derived in the former basis. Comparisons with experimental data and other computational work are provided. Implemented improvements in the Born-Oppenheimer code are also introduced, with results shown for the HeH$^+$ molecule. A new project involving confined molecules will be briefly introduced.
    • Investigating the Role of Obesity and Obstructive Sleep Apnea in Hepatocellular Carcinoma Progression

      Sweeney, Nathan (The University of Arizona., 2018)
      Primary liver cancer is the seventh most common cancer worldwide and the second highest cause of cancer mortality. The incidence of hepatocellular carcinoma (HCC) has increased 80% in the past two decades and now comprises 85% of all primary liver cancer. Obesity increases the risk of developing HCC two-fold in women and five-fold in men. Co-morbidities common to obesity including non-alcoholic steatohepatitis (NASH), hepatic inflammation, and lipid accumulation increase the risk of developing HCC. Obstructive sleep apnea (OSA), a state of chronic intermittent hypoxia which is common in obese individuals, also increases the incidence of NASH. With a U.S. population that is approximately 33% obese, having OSA at 30-50%, we estimate the co-incidence of obesity and OSA is 10-16.5% of the entire U.S. population. Diet-induced obesity or intermittent hypoxia induces hepatic lipid accumulation and diet-induced obesity was recently shown to promote HCC tumor development. Whether obesity, chronic intermittent hypoxia, and their combination hasten hepatic lipid accumulation and HCC tumor progression remains unclear. In our studies, we monitored tumor development utilizing micro-computed tomography imaging and discovered that tumors developed fastest in mice that consumed a high fat diet. Upon further investigation, these mice also tended to have higher serum levels of AST and ALT and gained more weight than their counterparts. However, the addition of hypoxia lead to a decrease in weight gained, as well as a reduction in hepatic lipid accumulation and tumor formation. Extraction of mRNA from mouse livers revealed an up-regulation HIF-1α in mice fed a high fat diet without treatment with hypoxia that correlated strongly with tumorigenesis. Remarkably, hypoxia was found in mice treated with hypoxia as well as the mice that were fed a high fat diet only. These findings suggest that hepatic lipid accumulation produces endogenous hepatic hypoxia which associates with increased hepatic HIF-1α expression that correlates with tumorigenesis. Collectively, these data reveal a mechanism that potentially explains progression from early liver disease to HCC.
    • Investigating the Economic Consequences of Atmospheric Nuclear Testing

      Meyers, Keith Andrew (The University of Arizona., 2018)
      During the Cold War the United States detonated hundreds of atomic weapons at the Nevada Test Site (NTS). Many of these nuclear tests were conducted above ground and released tremendous amounts of radioactive pollution into the environment. The primary aim of this dissertation research is to answer empirical questions regarding the social costs of atmospheric nuclear testing. My research focuses on two broad areas: 1) how do economic agents respond to the adverse effects of environmental shocks, and 2) how does policy shape responses to said shocks. My studies combine data from a myriad of agricultural, environmental, and public health sources and rely upon clearly identified reduced-form models to estimate the social costs of NTS activities. The United States’ nuclear weapons testing program had much larger effects than previously known. I find that radioactive iodine generated from nuclear testing contributed to hundreds of thousands of excess deaths from 1951 to 1978. Increases in mortality rates due to fallout occurred throughout the entire country and that substantial damage occurred in places far from the region typically considered to be ``Downwind"" of the NTS. This radioactive material also harmed agricultural production and led to billions of dollars of lost output (2016$). Expanding upon these results, I use fallout measures to instrument for agricultural productivity and study how policy shapes agricultural producers’ responses to adverse productivity shocks. Fallout shocks allow me to measure how farmers respond to adverse productivity shocks when the cause of the shock is unobserved and unanticipated from the perspective of the agent.
    • Validation of Hearing Aid Fittings by the Arizona Sonora Borders (ARSOBO) Projects for Inclusion

      Beukelman, Page Naomi (The University of Arizona., 2018)
      The Arizona Sonora Border (ARSOBO) Projects for Inclusion Hearing Healthcare clinic provides comprehensive audiologic evaluations and low-cost hearing aids to individuals in Nogales, Sonora, Mexico. After identifying the need for a fitting guide to properly adjust the hearing aids, we collected 110 patient audiograms and grouped the six most common configurations of hearing loss. Using simulated real-ear measures, we fit the hearing aids to each of the six common configurations of hearing loss, and recorded the appropriate settings to serve as a starting point for future hearing aid fittings. In an effort to determine the success of these hearing aid fittings (and others performed by the ARSOBO Hearing Healthcare program), we administered 29 questionnaires assessing hearing aid effectiveness. The International Outcome Inventory for Hearing Aids (IOI-HA) was the chosen outcome measure due to its international applicability and quick and simple format. In general, the hearing health care provided by ARSOBO yielded positive outcomes and favorable outcomes in each category of the IOI-HA. Potential confounding variables, limitations and future directions of the program are outlined. Additionally, the specific results of these outcome measures and the implications of our project/fitting guide on humanitarian audiology is discussed.
    • Between Menace and Model Citizen: Lima's Japanese-Peruvians, 1936-1963

      DuMontier, Benjamin John (The University of Arizona., 2018)
      The Japanese-Peruvian community in Lima, Peru used different understandings of race to assert its role in the country. This dissertation examines the changing racial and ethnic characterizations of Japanese residents in Peru between 1936 and 1963. Using archival research and oral histories this dissertation traces the category of “enemy alien” in Peruvian policy, a racial and legal category which overlapped with global conversations about anti-Asian “yellow peril” fears. This analysis pays close attention to one national context – Peru—and takes a long view on nation-state policies that influenced the lives of immigrants. In this context, I argue that understandings of race among Japanese-Peruvians had to do with the placement of Japan in global politics—and were not uniformly negative, depending on the historical moment. Peruvian officials formed their political agenda – and the subsequent treatment of Japanese-Peruvians –not solely in response to U.S. policies and interests in national security. Instead, domestic policies in the 1930s and actions by Japan abroad shaped the changing ways of addressing Japanese-Peruvians before, during, and after World War II. After the war, however, the Japanese-Peruvian community developed their own survival strategies amid changing national and global designations for their racial and political identities. They exploited the racial ambiguity that newspapers, government policies, and Peruvian laborers had towards Japan to claim new citizenship rights. This dissertation uses oral histories to trace how changing international political relations – and war – affected the efforts of immigrants to create a new homeland.
    • Distributed Point Source Method for Modeling Wave Propagation in Anisotropic Media

      Fooladi, Samaneh (The University of Arizona., 2018)
      Distributed Point Source Method (DPSM) is a modeling technique for solving various engineering problems including ultrasonic and electromagnetic wave propagation problems. The DPSM is extended to analyze anisotropic materials in this dissertation. The DPSM requires evaluation of elasto-dynamic Green's function between many pairs of source and observation or target points. For homogeneous and isotropic media, the Green's functions are available as closed form analytical expressions. However, for anisotropic solids, the evaluation of Green's function is more complicated and needs to be done numerically. Nevertheless, important applications, such as defect detection in composite materials, require anisotropic analysis. The Green's function for anisotropic solids consists of two integrals. One of them contains singular terms while the other one contains non-singular or regular terms. The regular part, being in the form of a 2D surface integral, is responsible for the majority of the computational time. For transversely isotropic materials, the integration domain of the regular part can be reduced from a hemi-sphere to a quarter sphere. This reduction of integration domain is utilized in this dissertation. In addition, a technique called ”windowing” is suggested which makes use of the regular pattern of relative position of the source and target points in DPSM, in order to avoid repetitive evaluation of the Green's function. As another attempt to further reduce the computational time, a calibration strategy is suggested in this dissertation which is based on an equivalent isotropic stiffness tensor, and results in a multi-resolution integration technique which sets automatically an optimum number of integration points for a finite number of distance intervals between the source and the target points. The developed DPSM model equipped with windowing technique and multi-resolution numerical integration is then applied to solve a number of example problems, and its applicability and effectiveness for simulating ultrasonic wave propagation in anisotropic media is examined.
    • A Randomization Test for the Detection of Differential Item Functioning

      Rockoff, David (The University of Arizona., 2018)
      A test question is said to contain Differential Item Functioning (DIF) if people who have the same ability level but are from different subpopulations have unequal probabilities of answering correctly. Detection of DIF is crucial to maintaining test fairness. Numerous DIF detection methods exist; none are ideal across a wide range of settings. I introduce a randomization test for DIF detection, and compare its performance to that of the Mantel-Haenszel, Logistic Regression and Lasso-based methods under a Rasch model using Monte Carlo simulations.
    • Lingua Franca: The Use of Labanotation in the Gestural-Based Compositions of Waye Siegel, Mark Applebaum, and Casey Cangelosi

      Maxwell-Doherty, Kyle Joseph (The University of Arizona., 2018)
      Over the last four decades of contemporary percussion literature, the inclusion of somatic gesture in solo and chamber percussion compositions has experienced significant growth. The addition of these deliberate physical movements often challenges the performer(s) in the interpretation of the gestural-based notation. The variety of schemes and notation systems employed by composers to document the precise instruction for these visual elements are numerous and growing. In this research, the compositions of Wayne Siegel, Mark Applebaum, and Casey Cangelosi will be studied, and when decidedly specific instructions for performer's physical movements are required, it will be demonstrated that Labanotation can facilitate the notation, interpretation, and performance of these specific gestural-based compositions. Labanotation was created to document the movement of dancers and its principal function is to archive the entirety of a choreographer's choreography: from the movement of each individual dancer, the relationship of one dancer to another on stage, to the somatic movements connection to the scored music. In its most basic form, a Labanotation score is the written record of artistic human movement. The use of Labanotation in these three compositions demonstrate its great potential to serve as a clarifying notation in the body of highly specific gestural-based literature. In addition to creating an archival platform for somatic performance, Labanotation allows scholars to approach gestural-based compositions in objective and quantitative ways. It has the ability to illuminate composer's themes, aids in pattern recognition, and highlights the intention behind physical movement. Through the notation of Wayne Siegel's Two Hands (not clapping) (2009), the re-notating of Mark Applebaum's Aphasia (2010) and Casey Cangelosi's Bad Touch (2013), Labanotation has the potential to encourage creative and innovative new works through the use of interdisciplinary collaboration and shared artistic language.
    • Analyses of Crystalline and X-Ray Amorphous Materials in Gale Crater Rocks and Soils

      Achilles, Cherie (The University of Arizona., 2018)
      The Mars Science Laboratory (MSL) rover, Curiosity, is exploring the layered sediments of Gale crater with the primary goal the primary goal of finding and assessing environments that are, or once were, favorable habitats for life. Curiosity’s scientific payload was designed to analyze the mineralogical, geochemical, and textural properties of rocks and soils encountered by the rover. Among this payload is the CheMin X-ray diffractometer, an instrument that provides data to determine the identity of crystalline phases present at >1 wt%, the crystal chemistry of major minerals, and the distribution of crystalline, clay mineral, and amorphous phases in each analyzed sample. Mineralogical assessments are important to understanding sediment sources, weathering histories, depositional environments, and diagenetic processes that influenced the formation of analyzed soils and rocks. This dissertation discusses the mineralogy and crystal chemistry of an active eolian dune in Gale crater and compares the results to the basaltic soils analyzed by the Mars Exploration Rovers and to the predicted mineralogy of the dune field based on orbital spectral measurements. Quantitative mineralogical analyses of an eolian dune sample, named Gobabeb, revealed that the sand is dominated by basaltic minerals and X-ray amorphous phases. Plagioclase, olivine, and two Ca-Mg-Fe pyroxenes account for the majority of crystalline phases detected. Minor phases include magnetite, quartz, hematite, and anhydrite. The X-ray amorphous fraction, ~42 wt% of the Gobabeb sample, is composed primarily of SiO2, FeOT, Al2O3 and SO3. Proposed amorphous phases include basaltic glass, maskelynite, amorphous silica, nanophase iron oxides, and amorphous sulfates. The predicted mineralogy of the Bagnold Dune Field based on VNIR (visible-near-infrared) and MIR (mid-infrared) orbital spectral measurements shows high fidelity to in situ CheMin mineralogical analyses. Feldspar and olivine abundances are consistent with each other, and the CheMin-derived composition of the olivine, Fo56(3), is nearly identical to the value calculated from orbital analyses, Fo55(5). In addition to Gale crater eolian materials, this dissertation describes the mineralogy of four mudstones from an ancient lacustrine environment and discusses how mineralogical trends were used to identify lake and groundwater fluid conditions that interacted with detrital sediments over time. The crystalline, clay mineral, and amorphous phase distributions for the Oudam, Marimba, Quela, and Sebina drill samples were estimated from CheMin diffraction analyses. The mineralogies of these four samples are dominated by plagioclase, Ca-sulfates, hematite, and phyllosilicates. The mineral phase assemblages suggest mafic detrital sources for all drill samples and contribution from a silicic source in the Oudam drill sample. The presence of hematite and Ca-, Fe- and Mg-rich sulfates indicate that all four drill sites were exposed to oxidizing conditions, dominantly diagenetic. X-ray amorphous components are SiO2-rich (~50 wt%) suggesting the presence of amorphous silica, aluminosilicates, and/or Fe-silicates. Overall, mineralogy of the analyzed lacustrine rocks suggests a depositional environment where sediments were exposed to open-system aqueous alteration processes and subsequent diagenetic events resulting in the formation of matrix Ca-sulfates and hematite. Lastly, a crystal structure redetermination of lead manganese hydroxide mineral, quenselite, is discussed. Single crystal diffraction methods were utilized to determine quenselite unit-cell parameters, a = 9.1618(6), b = 5.6927(3), c = 5.6191(3) Å, β = 92.979(3)°, and V = 292.67 Å3. Although quenselite is not a martian-relevant mineral, a fundamental understanding of atomic bonding, structure determination, and publication of crystallographic information files (CIF) are essential to the analysis of powder diffraction data. The results presented in this dissertation illustrate the significance of mineralogical analyses to the characterization of eolian and fluvio-lacustrine sediments on Mars.
    • Computational Explorations in Morphology

      Kloehn, Nick (The University of Arizona., 2018)
      This dissertation is composed of three papers that each summarize computational investigations in morphology. The first paper studies the relationship between nominal classification and complexity in language. It subsequently introduces a model for this relationship called the association model of nominal classification. This model claims that nominal classification aids in word storage in gendered languages. These claims are supported by data from German, French, English and Iraqw. The second paper investigates quantitative approaches to measuring the productivity of affixes in Swahili. It subsequently introduces a novel model of measuring productivity called the cumulative root ratio. This model gives a story for the variables that determine whether an affix is productive, and data come from corpus data of Swahili. The third paper studies the relationship between the semantic cohesion of derived words, and the meaning of the affixes which they contain. This study introduces the idea of semantic class coherence and argues that this is correlated with word decomposition in lexical access, and likewise is a prerequisite for affix productivity. This model is supported by data from English word vector space models, along with other corpus data from WordNet and Celex. These three papers each are examples of original research that study human language at the word level using data driven methods. This method of employing computational modeling and machines to investigate human language allows us to better understand the ways in which humans can interact with, acquire, and produce language.