• Ecologies of Care: How Cross Border Humanitarian Organizations Support Asylum Seekers in Arizona-Mexico Border Towns

      Bacelar da Silva, Antonio José; Blumberg, Julia Irene; Brewer-Osorio, Susan V.; Retis, Jessica M. (The University of Arizona., 2022)
      In early 2019 the Trump administration implemented the Migrant Protection Protocol (MPP), also known as the Remain in Mexico Policy. As a result of this rule, asylum seekers are now being sent to wait for their US asylum proceedings in Mexico (Ahmed, 2018). 647,919 individuals were apprehended during fiscal year 2021 with 110,400 individuals detained in May alone (Nationwide Enforcement Encounters, 2021). Since 2014, Southern Arizona has seen an unprecedented influx of asylum seekers, mainly from Central America, prompting a large public humanitarian response involving both the public and private/non-profit sectors. This research explains the emergence and dominance of private organizations for supporting migrants in the United States. It also explains the contextual and personal challenges confronting private organizations that support migrants in the United States. With this I seek to understand the varied landscape of care surrounding asylum seekers between the state, non-governmental organizations, and the public. This thesis is a qualitative study utilizing semi-structured interviews with leaders and volunteers of non-profit organizations involved in receiving asylum seekers on the Arizona-Mexico border. The main goal of this project is to document the motivations and impacts of this broad humanitarian effort in southern Arizona and to put a spotlight on organizations that work to humanize the border reality.
    • Examining Social Vigilance and Associated Physiological Effects Across Types of Situational Stress

      Ruiz, John M.; O'Neill, Riley M.; Sbarra, David; Hamann, Heidi (The University of Arizona., 2022)
      Emerging work over the past four decades supports psychological stress as a critical determinant of cardiovascular disease (CVD). Previous research has supported social vigilance, or active watchful monitoring of one’s social environment for interpersonal challenges or threats, as a candidate biobehavioral process linking stress exposure to adverse cardiovascular reactivity and recovery profiles. Review of findings in this area reveals the need for research examining whether experimentally controlled contextual vigilance cues evoke the hypothesized biobehavioral responses. The current study randomized 135 undergraduate young adults (49% male, 51% female; Mage = 19 years, SDage = 4 years) to one of three videogames standardized as all first-person shooter scenarios, with the manipulation across games being type of situational stress (challenge, threat, neutral). Participants’ dispositional social vigilance was measured via trait assessment, and participants’ cardiovascular reactivity (CVR) was measured prior to, during, and after the experimental task. Analysis of covariance (ANCOVA) models revealed higher stress games evoked significantly more CVR than the neutral game, especially in the case of threat condition. Participants in the high threat condition also demonstrated the least overall recovery to baseline blood pressure. No effects of vigilance disposition were observed during gameplay and modest effects of higher vigilance were associated with better physiological recovery, in contrast to expectations. These findings contribute to understanding how higher threat social situations may connote CVD risk through pull for greater preparatory monitoring and the acute cardiovascular responses corresponding to that behavior.
    • Statistical Relationships Between Groundwater, Climatic, and Economic Factors in Southeastern Arizona

      Colby, Bonnie; Condon, Laura E.; Pereira, Mekha; Meixner, Thomas (The University of Arizona., 2022)
      Hydrologic, climatic, and economic factors interact in complex ways to influence groundwater conditions. These relationships can be difficult to measure and simulate but are important to understand for long-term water resource planning purposes. Knowledge of factors linked with groundwater levels in a basin can help water managers develop targeted and effective strategies to incentivize desired water use outcomes. Existing studies focus on areas of large-scale irrigated agriculture or highly urbanized areas, and utilize data on groundwater use. In much of rural Arizona, and much of the world, groundwater use data is not available and difficult to collect. The goal of this study is to instead explore responsiveness of groundwater level data to economic signals in rural areas. We focus on two rural areas in southeastern Arizona, along the upper portion of the Santa Cruz and San Pedro watersheds. Using an econometric approach, we employ a fixed effects regression model with a groundwater level metric as the dependent variable, and climatic and economic factors as explanatory variables. We find well counts, housing units, per capita income, and planted acreage have statistically significant relationships to groundwater levels in these rural areas at the annual scale. We also highlight some of the challenges of data availability when performing econometric studies related to groundwater in rural areas. Despite these challenges, this unique approach could be helpful to understanding influences on groundwater conditions in areas of the world where water use data is unavailable.
    • Correcting Structured Illumination Aberration Effects in Structured Illumination Microscopy

      Peng, Leilei; Jacobson, Alex; Kieu, Khanh; Liang, Rongguang (The University of Arizona., 2022)
      The resolution of an optical microscope is limited to roughly 250 nm for biological imaging. This is due to the wave nature of light which causes an optical system to be diffraction limited according to the wavelength of light involved and the numerical aperture of the system. In order to image finer structural details of biological samples it is necessary to image beyond the diffraction limit. There are several methods for doing this. One method for imaging beyond the diffraction limit is structured illumination microscopy (SIM), a type of fluorescence microscopy where high frequency information is put into low frequency space by using a periodic illumination pattern at different phases. One of the difficulties with this method is that experimentally the periodic illumination pattern will never be ideal since it will suffer from the aberration effects of the system. This thesis presents a computer program with an algorithm to correct for the aberration effects in the periodic illumination which corrects independent of any specific type of aberration introduced into the structured illumination. The computer program first simulates one dimensional linear SIM, adds in aberration effects, and then corrects the image. The results show that the algorithm improves the superresolution image for the conditions of 0.5 wave, 1 wave, and 2 wave aberration effects in the structured illumination. With this computer program as a foundation, future work could expand the program to include two-dimensional nonlinear SIM for experimental applications.
    • Comparison between the Early Chinese and Japanese Labor Movements: A Focus on Historical Conditions

      Lanza, Fabio; Xiang, Jie; Schlachet, Joshua; Ren, Hai (The University of Arizona., 2022)
      Labor movements represent social protection systems designed to serve as survival means for workers, usually executed in the form of picketing, peaceful demonstrations, and boycotts. This paper explores past studies on the labor movements in China and Japan, compares and contrasts their characteristics, and explains the various factors that made the Chinese socialist labor movement extend beyond Japan’s. The Japanese labor movement was disproportionately instigated by non-government and non-political reasons. A significant proportion of the factors that spurred the Japanese labor movement was associated with the need to increase workers’ wages and status. On the other hand, nationalism, spurred by oppression, was the most important factor that contributed to the success of the Chinese Socialist labor movement. Imperialist antagonism greatly abused Chinese labor influence through private enterprises, indirectly disassembling the country’s feudal economy. The early industrialization experienced in Japan was dissimilar to that experienced in China because the latter was subjected to increased colonial presence, while Japan was in the process of initiating the Meiji Restoration and westernization. Between 1900 and 1920, China was in a semi-colonial and semi-feudal state while Japan was a colonialist country. Unlike China’s labor movement, the emergence of the Japanese labor movement was sudden and without any formal organization. Japanese labor movements also had minimal rivalry from various inter-city workers’ movements compared to the Chinese labor movements. Since China and Japan were experiencing different national situations between1900 and1920, they experienced different impacts of nationalism on their labor movements.
    • How do Wood Anatomical Traits in Salix Vary in Response to Flooding? A Case Study from the Yenisei River, Siberia

      Meko, David; Thaxton, Richard Douglas; Hu, Jia; Panyushkina, Irina (The University of Arizona., 2022)
      Recent, record-breaking discharge in the Yenisei River, Siberia, is part of a larger trend of increasing river flow in the Arctic driven by Arctic amplification. These changes in magnitude and timing of discharge can lead to increased risk of extreme flood events, with implications for infrastructure, ecosystems, and climate. To better understand the changes taking place, it is useful to have records that help place recent hydrological changes in context. In addition to an existing network of river gauges, extreme flood events can be captured in the wood anatomical features of riparian trees, which help identify the most extreme flood events. Along the lower reaches of the Yenisei River, Siberia we collected white willow (Salix alba) samples from a fluvial fill flat terrace that occasionally floods when water levels are extremely high. Using these samples, we use an approach known as quantitative wood anatomy (QWA) to measure variation in radial cell dimensions, particularly fiber lumen area and cell wall thickness. We then use Pearson correlations to compare these measurements to observed records of flood stage. We hypothesize that (1) intra-annual changes in wood fiber size (LA) and cell wall thickness (CWT) in Salix rings can be quantified using QWA, and (2) these patterns are related to flood magnitude and/or duration. We find that normalized wood fiber CWT best captures intra-annual density fluctuations (IADFs) found in Salix rings. For some trees, time series of normalized CWT correlate with July flood durations, which have profoundly changed since the 1980s. Understanding how riparian vegetation responds to extreme flood events can help us better manage riparian ecosystems and understand changes to the Arctic hydrological regime.
    • A Change in the Worker’s Party: Evolution of The People’s Republic of China’s Rhetoric in the Twentieth Century

      Lanza, Fabio; Rahmer, Sebastian; Gregory, Scott W.; Schlachet, Joshua (The University of Arizona., 2022)
      Having come to power following decades of western imperialist intrusion, dynastical degradation, and a brutal civil war, the People’s Republic of China touted its connection to Communism and its desire to assist in worldwide efforts to remove imperialism and colonialism. China’s government worked on its international image even when large parts of the western world had yet to recognize its legitimacy, through acts such as participating in the 1955 Bandung Conference and supporting anticolonial efforts on several continents, including the Black Power movements of mid-century United States. Using military, diplomatic, and economic means, the Chinese Communist Party transformed its approach to international relations over time, especially after the international recognition of the People’s Republic of China and its further entrance onto the world stage as China grew into an economic powerhouse. Its alliances and friendships with other nations and with non-state movements transformed alongside its approaches, causing their circle of acquaintances to look very different from the foundation of the country to its point of international recognition. This paper will explore the evolution of China’s international relations in terms of their message of anti-colonialism and anti-imperialism. Both were tenets of the Chinese Communist Party’s ideology, and while they have remained a central part of its messaging, their relative importance has ebbed and flowed over the years.
    • RNAI-Mediated Knockdown of Sugar Metabolism and Transport Genes in Bactericera Cockerelli (SULC)

      Brown, Judith K.; Arad, Neda; Riehle, Michael A.; Baltrus, David A. (The University of Arizona., 2022)
      The citrus greening disease is among the most damaging disease of citrus known to be caused by an insect-transmitted, fastidious bacterial pathogen. In this study, five genes involved in sugar metabolism and transport in the gut of potato psyllid (PoP), Bactericera cockerelli (Sulc) (Psylloidea: Triozidae), a surrogate study system for the Asian citrus psyllid (ACP), were evaluated for knockdown using RNA-interference (RNAi). Knockdown was quantified by real-time quantitative PCR (qPCR) expressed as fold-change in gene expression relative to water and a non-target sequence, luciferase. Silencing AQP2 and TRET1 resulted in 20-30% PoP mortality by 9 days post-inoculation (dpi), either individually, or combined and delivered as a group, or ‘stacked’, with other dsRNA targets. Among the five targets tested for dsRNA-mediated knockdown, silencing of AGLU1 resulted in the earliest and the greatest mortality in potato psyllid, both individually and stacked. Knockdown with different combinations of the other four targets revealed that the greatest PoP mortality was achieved from knockdown with all five dsRNAs, at 65.11%. Different combinations of dsRNAs were evaluated to determine if knockdown could be attributed to additive or synergistic effects of knockdown of two or more targets. Among the dsRNAs evaluated Trehalase and Alpha-glucosidase showed synergistic effects based on the qPCR analysis and by increased mortality. Also, RNAi penetrance and persistence of knockdown were enhanced over time, by stacking certain dsRNAs. Results showed that dsRNA screening by oral ingestion of dsRNAs delivered in a 20% sucrose solution was informative for evaluating the potentially deleterious effects of either single or ‘stacked’ dsRNAs on mortality and other phenotypes.
    • Predictive Inference Tools for Researchers

      Billheimer, Dean; Harris, Voyze G.; Bedrick, Edward J.; Piegorsch, Walter (The University of Arizona., 2022)
      An obstacle to widespread employment of Bayesian predictive inference in scientific re-search is the lack of suitable computing tools. In this thesis I document several established useful models, and provide an applicable set of tools for statisticians. For each of the in- cluded models, some basic notes on mathematical derivation are presented, and predictive inference is illustrated with examples. For the details of the models and some of the exam- ples I relied primarily on Seymour Geisser’s Predictive Inference: An Introduction (1993) [3] and Peter D. Hoff’s A First Course in Bayesian Statistical Methods (2009) [5]. An R package has been developed, the main purpose of which is to provide the researcherwith a means of generating samples from predictive distributions. So for all the models, the package includes predictive sample generators. For those models with analytical solutions, density and distribution functions are also provided. The standard R naming convention for these function classes has been adopted: density functions are prefixed with the letter“d,”distribution functions with the letter“p,”and sample generation functions with the letter “r.” Also included in all function names is the abbreviation “pred” (for predictive) and an initialism or abbreviation identifying the model itself. For example, the density function for the Beta-Binomial model is named“dpredBB().”The R code for each function is included in the Appendix.
    • Delayed Tree Dormancy Resulted in Higher Annual Savanna Gross Primary Productivity in the Northern Sonoran Desert

      Moore, David J.P.; Steiner, Blake; Hu, Jia; Scott, Russell (The University of Arizona., 2022)
      Drylands support over two billion people and savannas contribute about 25% to global gross primary productivity (GPP). Savannas are water limited ecosystems characterized by two dominant plant functional types: trees and an understory of grass and forbes. It is hard to predict how future changes in water across time and space will affect savanna GPP. This is due to, in part, to trees and understory species having different leaf phenology and rooting depths. By integrating three established models of the carbon-water function of drylands, we developed a general hypothesis that incorporates the phenology and root architecture of the two dominant plant functional types to explain savanna GPP controls. We test the hypothesis that productivity in savanna ecosystems is controlled by the temporal and vertical distribution of soil moisture and differences in leaf phenology growing season length of understory and tree functional types. We used phenology cameras, satellite observations from the MODIS sensors, and an in-situ tower equipped to measure carbon flux by eddy covariance to quantify tree and understory phenometrics, savanna phenometrics, and savanna GPP respectively. To quantify available water resources, we measured rainfall and soil moisture accumulation at two different depths (shallow, < 30 cm | deep, > 30 cm). We found that the leaf phenology of trees and understory plants were distinct from each other and that each plant type was active during periods of different water availability. We found also that the effect of water on GPP varied by season, with GPP being driven most by soil moisture from the summer (R2 > 0.38, shallow & deep), then spring (R2 > 0.23, shallow and deep), and finally the winter (R2 = 0.19, only deep). While the length of the savanna growing season was not related to GPP, delayed leaf senescence tended to increase annual GPP. By comparing the response of leaf phenology in trees and understory to the phenology of the whole ecosystem estimated from satellites, we found that trees showed a similar leaf senescence response to the senescence response of the whole savanna; that the availability of deep soil moisture tended to delay leaf senescence (R2 = 0.96 for trees & R2 > 0.29 for savanna, respectively). In contrast, more shallow soil moisture tended to advance leaf senescence in the understory (R2 > 0.81). These major findings are consistent with our general hypothesis and highlight the important and sometimes compensating effects of rainfall during winter and monsoon seasons. It is likely that any future increase of heavy winter precipitation would assist tree productivity and overall carbon gain in these semi-arid savanna ecosystems.
    • A Chemoenzymatic Approach to Stereospecific Green Synthesis of Rhamnolipid Biosurfactants

      Pemberton, Jeanne E.; Roberts, Tyler William Glen; Aspinwall, Craig A.; Christie, Hamish S. (The University of Arizona., 2022)
      Surfactants are an integral component of the modern industrial and consumer economies. They perform indispensable functions and yet their production and disposal pose grave environmental concerns. To address these concerns, work has been undertaken for several decades in the burgeoning field of biosurfactants – surfactants derived from biological sources. Of the biosurfactants, rhamnolipids are perhaps one of the most promising. They boast superb surfactant performance, are structurally simple, and are, most importantly, environmentally benign. Chemical approaches to the production of biosurfactants have been undertaken for a number of years with limited industrial applicability. Recent developments from the Pemberton lab, however, open new, industrially relevant synthetic pathways to rhamnolipids. Until this point, even these state-of-the-art production methodologies have lacked the ability to control for rhamnolipid stereochemistry. Natural products are given in high diastereomeric purity from their correspondent biological sources. The lack of stereochemical control results in either impure products or sacrifices yield, efficiency, and green indices if diastereomeric purity is achieved. To address this issue, the present work reports a chemoenzymatic approach to the stereospecific and green synthesis of rhamnolipids. Immobilized lipase B of Candida antarctica was used to provide enantiomerically pure starting materials for rhamnolipid synthesis. Optimal enzyme performance parameters such as time, temperature, conversion efficiency, etc. were quantitatively determined, primarily using spectroscopic methods. Diastereomerically pure rhamnolipid products were subsequently synthesized and characterized by standard methods. In addition, their interfacial properties were investigated using surface tensiometry with a du Noüy ring, and key parameters such as CMC, γCMC, and Γm were determined and/or calculated. The reported work demonstrates a novel advance in the field of biosurfactant production by chemical means, and a controlled synthesis that maintains green indices and is industrially relevant can now be achieved.
    • Performance Evaluation and Optimization of RPL in Broadband-PLC Network for Advanced Metering Infrastructure

      Rozenblit, Jerzy W; Kim, Jaewan; Adegbija, Tosiron; Cao, Siyang (The University of Arizona., 2022)
      Power line communication (PLC) is one of the key fashions of communication for the Advanced Metering Infrastructure (AMI) systems in most power utility companies due to saving the expense of installing communication media using existing power line infrastructure. It has been used in smart grid such as AMI systems in which embedded smart meters periodically transmit power consumption. However, the existing PLC Network stability was not enough to perfectly provide AMI services to customers such as on-demand, time of use, remote disconnection, and so on. Since the PLC environment looks like a wireless communication environment, some utilities and papers tried to present novel approaches for RPL and 6LoWPAN of IoT technology elements with these similarities in mind. These trials were almost only RPL basic function (OF0) implementation and showed the applicability of RPL and 6LoWPAN to the PLC network (i.e. confirmation that newIoT technology elements are applied to the existing PLC network). In this thesis, we propose a practical and novel approach to RPL technology in the field of AMI systems and evaluate RPL performance over PLC from the perspective of the power utility company (i.e. performance metrics: meter reading success rate such as timely, daily, and monthly). For this, we apply an RPL function to a multi-hop PLC network, implement an OF-PLC routing algorithm considered for PLC characteristics changed by power grid environment (impulse noise) and evaluate the AMI performance through an extensive real-world testbed. The performance evaluation includes the AMI performance of the PLC network based on RPL, compared to the existing PLC network through the real field.
    • Exploring Firescape: Staff and Stakeholder Attitudes Toward Fire Restoration Practices and Managing Change on the Coronado National Forest

      Falk, Don; Ruyle, George; Schram von Haupt, Lea; Baldwin, Elizabeth (The University of Arizona., 2022)
      Changing climates and anthropogenic disturbances have caused ecosystems to begin to shift across the US. In response, land management agencies are increasingly examining their role in managing their resources in the context of rapid change and potentially widespread ecosystem transformations. Climate change, land-use changes, and historic fire suppression have led to greater size and severity of wildfires, leading to negative high-severity fire effects on the landscape. Planning landscape level actions to respond to these conditions through the National Environmental Policy Act and other Federal guidance requires a deep understanding of how staff and stakeholders view ecosystem change and resilience. To assess these views, we administered an electronic survey to 182 stakeholders of Coronado National Forest; semi-structured interviews were conducted with 17 staff.Although there has been increasing recognition of the importance of fire for different ecosystems, land managers still face challenges in both planning requirements and implementation of landscape scale fire restoration plans. On the Coronado National Forest, our research showed a growing acceptance of ecosystem change among stakeholders and general agreement between the general public and land managers on management priorities. However, there is still room for improvement when it comes to communication and public engagement, monitoring metrics, and alignment between research and practice.
    • Early Childhood Teachers’ Experiences During the COVID-19 Pandemic

      Pope, Elizabeth; Khalid, Maham; Cheng, Katherine; Burross, Heidi (The University of Arizona., 2022)
      The COVID-19 pandemic posed unique challenges for early childhood teachers while facilitating the learning and development of young students. This study examined early childhood teachers’ (K-2 grade levels) experiences with online/hybrid classes and the transition back to in-person classes from Spring 2020 to Fall 2021, in Pakistan and the US. It comprised of two phases: survey (consisting of closed- and open-ended questions) (n = 53) and interviews (n = 12). Survey findings from closed-ended items indicated some shared experiences of teachers in the US and Pakistan with regards to student engagement, use of technological tools, support/resources from school administration, peers, and parents, collaboration with parents, and stress during online classes, as shown by t-test results (ps > .05). Pakistani teachers reported higher scores within the themes of students’ internet accessibility, preparedness (online/hybrid and in-person classes), self-efficacy (online/hybrid classes), and US teachers reported higher scores within the theme of stress (in-person classes) (ps < .05). Common challenges with the transition back to in-person classes that teachers in Pakistan and the US reported in the open-ended survey items were the students’ learning gaps and the need for social-emotional learning. Following themes emerged from the interview responses of teachers: Online Classes (proficiency in technology-use, challenges of online teaching, limited resources, parental involvement, planning, student engagement, increased workload, positive aspects of online teaching), Challenges of hybrid teaching, In-person Classes (adjustment for teachers and students, learning gaps), Suggestions for School Administrators. Some experiences that were unique to Pakistani teachers and affected their experiences with online classes also showed up, like electricity shortages disrupting online classes, and gender-based expectations of managing household responsibilities, leading to increased workloads for female teachers.
    • A New Way of Fabricating High-Porosity Parylene Membranes for High-Throughput Capturing of Viable Circulating and Exfoliated Tumor Cells from Large-Volume Bodily Fluids

      Gu, Jian; Rabadi, Inad S.; Zenhausern, Frederic; Sharma, Shalini (The University of Arizona., 2022)
      We report a simple method using just photolithography and reactive ion etching to fabricate high porosity Parylene-C porous membranes to process large volume of samples for liquid biopsy. A range of membranes have been fabricated with porosity ranging from 39 to 76 %. In comparison, track-etched polycarbonate membrane has a 5% porosity, and previously reported Parylene membrane had a ~ 45% porosity. A surprising vertical sidewall was observed in etched Parylene pores, which was contributed to the photoresist melting during high DC bias (420V) plasma etching. A circulating tumor cell (CTC) capture device was developed, and buffer sample processing rate up to 200 ml/min (limited by the device’s geometry) was obtained for membranes with porosity of > 47%. A low cell count method with ±1 cell accuracy was developed to characterize the spiked cell capture. The device showed high capture efficiency of 87 to 92% for low spiked cell numbers (< 50 cells). Preliminary results also showed over 90% viability for the captured cells. The simple Parylene etching process is promising for low cost fabrication of high porosity Parylene membranes for liquid biopsy applications.
    • Deformation Loss in Slope Stability Radar Monitoring

      Ross, Bradley J.; Momayez, Moe; Brock, Ryan; Kemeny, John (The University of Arizona., 2022)
      Slope deformation data were obtained at an open pit copper mine in Arizona using a ground based synthetic aperture interferometric slope stability monitoring radar. These data were directly compared to geodetic prism data acquired by the mining company. The prism data were from the same areas in the pit and the same timespan as the radar data. This direct comparison of deformation as measured by the prisms to deformation as measured by the radar allowed for the demonstration and discussion of the dominant phenomena which effect the accuracy of ground based interferometric slope stability monitoring radars. This study is particularly relevant to radars which use a statistical algorithm to model and correct for atmospheric effects on the radar data, however some of the general conclusions also apply to ground-based radars that use other correction methods.
    • High Pulse Energy Single Frequency Fiber Laser at 2 Micron Wavelength

      Norwood, Robert; Jiang, Runting; Jiang, Shibin; Liang, Rongguang (The University of Arizona., 2022)
      In this thesis, high pulse energy single frequency fiber laser at 2 micron wavelength is designed and constructed with thulium-doped silicate fiber amplifiers. Starting from designing the polarization-maintaining (PM) thulium-doped silicate fiber amplifiers with master oscillator power amplifier (MOPA) configuration, three different Tm-doped fibers with core size 30 μm, 40μm, and 60 μm are assembled. Testing the fiber amplifiers with continues wave (CW) lasers at 1950 nm and 1977 nm, the final output power can reach as high as 30 W. Using five stages of amplifiers in the laser system, an all-fiber nanosecond single frequency laser at 1977 nm with 1.65 millijoules pulse energy output was firstly assembled.
    • Precipitation Patterns Influence on Greenland Ice Sheet Regrowth During the Last Interglacial Period: CESM2 Simulation

      Lofverstrom, Marcus; Berry, Allison Renee; Tierney, Jessica; Yin, Jianjun (The University of Arizona., 2022)
      The Greenland Ice Sheet (GrIS) is highly vulnerable to climate warming. Most obvious are the threats of sea-level rise due to GrIS melting, but there are also far-reaching climate effects through complex interactions with atmospheric and oceanic circulation that control the hydroclimate in the North Atlantic. To better understand how the GrIS regrows following an extreme deglaciation event during warmer climates, we analyze a unique, transient simulation of the Last Interglacial warm period (LIG; 127 to 119 ka; thousand years before present) with the Community Earth System Model Version 2 (CESM2) that includes an interactive ice-sheet component. Although the LIG warmth is primarily attributed to high summer insolation and is therefore not a perfect analog for greenhouse gas dominated anthropogenic global warming. The lowest values of surface mass balance occur at 122 ka, when the GrIS has separated into a large northern dome and a smaller southern dome. By 120 ka, the two domes are reconnected as the ice sheet begins to regrow as the summer climate continues to cool. In the modern climate, Greenland receives most precipitation during winter months along the southeastern coast. However, in the LIG simulation, winter precipitation is reduced in this region, while summer precipitation is more abundant. This is contradictory to modern climate, as precipitation during summer months tends to be most abundant in western Greenland. Understanding the dynamics of this response is not only key for interpreting proxy-data signals in past climates but may also be important for improving predictions of storm track dynamics and water resources availability in the face of climate variability and change.
    • Partner Support as a Buffer between Parental Depressive Symptoms and Parental Engagement

      Barnett, Melissa A.; Vasquez, Maria Belinda; Curran, Melissa A.; Speirs, Katherine (The University of Arizona., 2022)
      The risks and economic pressures experienced by low-income families can lead to psychological distress such as depressive symptoms (Masarik & Conger, 2017), which can impact parenting behaviors. The present study addressed how parental depressive symptoms might be a risk associated to parent-child relationships, especially positive parental engagement. Using a risk and resilience framework, the current study is the first to explore three forms of partner support (emotional support, financial support, and emergency child-care support) as potential protective factors that buffer the association between depressive symptoms and parental engagement among N = 3,165 mothers and fathers of three-year-olds. Participants were predominantly unmarried and from diverse minority ethnic backgrounds (Hispanic= 24%, Black Non-Hispanic=57%, White Non-Hispanic=17%, and other race=2%). Results indicated that parental depressive symptoms are negatively associated with positive parental engagement. The more depressive symptoms a parent is experiencing, the less likely they are to participate in positive parental engagement activities (e.g., singing, playing). Findings also suggested that emergency child-care partner support was a protective factor only for fathers. Emotional partner support and financial partner support were not a significant buffer for mothers or fathers. Findings highlight the need to address mental health needs in low-income families and explore complex associations between parenting practices and potential protective factors that promote resilience.
    • Renal Cell Carcinoma: American Indians, Metabolism, Metastasis, and Treatment

      Badger, Terry; Cordova-Marks, Felina; Lybarger, Lonnie; Briehl, Margaret (The University of Arizona., 2022)
      Renal cell cancer disproportionately affects American Indians/Alaskan Natives. This same population is also not included in published clinical trials and not reported on in published renal cancer clinical trials. Renal cancer treatment is needed that not only implements targeting new pathways or combinations of pathways that have not been targeted prior and integrating with traditional health. Almost 2/3 of American Indian’s report utilizing traditional medicine and cancer patients from this population report seeking traditional healers. New potential interventions should be created that combine traditional health with western medicine focused on metabolic pathways. Blocking in one treatment HIF1 and SIRT2; a separate treatment blocking VEGF and production of interleukins 6 and 8; and increasing BPTES to decrease glutamine; as well as adding in traditional aspects of health such as sweat ceremonies and usage of sage for example. Combining both western medicine and traditional health could increase the quality of life and outcomes for this population.