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Riparian Nitrate and Phosphate Removal Under Future Climate Scenarios
Get PDFRiparian buffer zones are specially managed zones that lie between agricultural fields and rivers, lakes, or wetlands. They are crucial for protecting water quality, human health, and ecosystem function. Critical ecosystem services of riparian soils include nitrogen removal via denitrification and phosphorus retention through sorption on mineral surfaces. Soil moisture influences these processes by controlling the rate of oxygen diffusion and, therefore, the soil’s redox potential. However, soils are predicted to be drier as climate change progresses, and these changes in soil moisture conditions will alter nitrogen cycle dynamics and phosphorus removal in riparian systems. We conducted a lab experiment to investigate potential changes in riparian ecosystem services brought on by climate change. We hypothesized that climate-induced shifts in moisture dynamics would enhance phosphorus removal but hinder denitrification due to increased oxygen diffusion caused by lower soil moisture conditions. We collected forty-eight soil cores (5 cm diameter, 15 cm height), and we collected additional samples for particle size, bulk density, and powder X-ray diffraction (XRD) analyses. We applied soil treatments in a fully factorial design, considering soil texture (sandy loam versus silty clay loam), antecedent soil moisture (field capacity versus drought), water application (flooding versus capillary rise), and pollutant quantity (simulated agricultural runoff versus deionized water). We primarily performed colorimetric assays on soil porewater and soil samples to determine NO3- and PO43- availability and movement. We also performed elemental analyses to complement the colorimetric assays. Our porewater chemistry and mass balance results showed significant changes in nitrogen cycle dynamics, showing evidence of denitrification, Dissimilatory Nitrate Reduction to Ammonium (DNRA), nitrogen fixation, and nitrogen mineralization. Statistical analyses of the data, primarily through generalized additive mixed-effects models (GAMMs), indicate significant individual and combined positive and negative effects (p<0.05) of the simulated treatments on porewater nitrate, ammonium, and phosphate concentrations, along with porewater pH and ARQ (CO2/O2). Critically, Moisture Regime and Water Application, our two climate proxies, both individually and collectively, significantly affected porewater nitrate, ammonium, and phosphate concentrations. Nitrate porewater concentrations are higher in decreased moisture conditions and changing precipitation as predicted under future climate scenarios. Phosphate porewater concentrations were lower in sandier soils, drought conditions, and capillary rise water application. However, phosphate leached out of the soil during simulated intense precipitation, highlighting the complexities of how predicted climate scenarios will be partially beneficial for phosphate sorption. XRD analysis revealed a mixed clay mineralogy, including a mixed-layer illite-montmorillonite, IS70R1. Additionally, clay mineralogy in clay-rich soil plays a statistically significant role in moderating the soil nitrogen cycle. Correlated extractable iron and nitrogen data indicate evidence of the Ferrous Wheel Hypothesis, especially in temporarily anoxic soils flooded by intense precipitation. Our research demonstrates that future climate scenarios affect key riparian biogeochemical processes and should be researched more thoroughly as the average worldwide temperature climbs above 1.5°C
NBA TICKET PACKAGE OPTIMIZATION, A CASE STUDY OF THE CLEVELAND CAVALIERS
Get PDFThe purpose of this study is to create a genetic algorithm to further enhance the current half season ticket packaging process in the event industry through a case study with the Cleveland Cavaliers of the National Basketball Association. The focus of this study is on the integration of machine learning and heuristic methods to simulate the human decision making currently taking place across the industry. This study will cover the methodologies being proposed for the overall, integrated approach. The methods that we cover in this study surround the tiering of events using K-Medoids and the makeup of the genetic algorithm that was implemented to solve for optimal half season packages using the Cleveland Cavaliers home schedule. Then, using the interaction between these two methodologies, we analyze the results in collaboration with domain experts from the Cavaliers. This study will show how the usage of machine learning paired with a genetic algorithm can affectively simulate and improve upon the current process for determining half season ticket packages. Furthermore, future improvements, such as the addition of predictive analytics and fan behavior are explored to supplement this work and lead to future areas of research and development
Survey of wind ensemble repertoire with double bass
Get PDFThe study of the use of the double bass in wind ensemble literature is limited. The double bass itself is a unique color instrument in wind bands, sometimes doubling with either the low brass section or low woodwind instruments, and in more recent repertoire often performing independent parts. Sometimes, wind band composers and conductors lack significant experience with string and especially, double bass technique. This project will analyze and explore various challenging figures from the wind ensemble repertoire that can pose some unique technical challenges to the double bass player in the wind band. In this project, I aim to examine scores of music, define potential problems for the double bassist, and suggest solutions and techniques. I aim for this project to serve as a resource for both ensemble directors and bass students to address the technical issues found in this repertoire. The pedagogical value of these studies is that they provide techniques for the bass player to address unique technical and interpretive skills while playing with winds. Chapter I will include the purpose, procedures and limitations for the study. The bulk of the content for this project will be to create a searchable database website as well as video demonstration of the techniques found in the literature. For each excerpt, the database will include song title, composer, reference links, metronome marking, and key arranged in chronological sequence. Therefore, in Chapter II I will examine related literature and provide links to the database website that I have created for this project. Chapter III will provide a brief history of the double bass in the wind band. Chapter IV includes a selection of often performed wind band compositions with challenging excerpts and technical solutions. This chapter is intended to be used with the website. Chapter V will include recommendations for programming and auditions repertoire for double bass students and Band directors and a conclusion
COMMUNITY-DRIVEN DECISION-MAKING IN COLLECTIVE IMPACT GROUPS: A PHENOMENOLOGICAL STUDY
Get PDFThis phenomenological study focused on better understanding the experience of participating in community-driven decision-making within collective impact groups. Through interviewing both collective impact facilitators (n=12) and collective impact group members (n=6), experiences related to both barriers and supportive elements arose. These experiences were coded into themes which ranged from external pressures and meeting logistics to interpersonal interactions, power dynamics, and self-awareness. Findings demonstrate that on average, these stakeholders experience effective community-driven decision-making occurring roughly 50% of the time within collective impact groups. Further, the way people define community-driven decision-making varies, especially during times where the group does not naturally agree on a course of action. This data helped highlight the need to create applied definitions of equity and community, to support psychological safety for group participants and facilitators, and to recognize alignment between barriers to community-driven decision-making and threats to psychological safety. Overall, this information can be used to guide future research related to creating mechanisms to measure the effectiveness of community-driven decision-making across different types of decisions and different types of groups. Also, it can help elevate ways group members can hold one another accountable to ensure equity and inclusivity is built into both group processes and outcomes related to decision-making
Blood and ink: A qualitative inquiry of teacher well-being in post-pandemic Oklahoma
Get PDFDuring the COVID-19 pandemic public schools were at the center of political debate related to educational content and curricula. Some conservative states moved to place tighter controls on schools in these dimensions with anecdotal evidence suggesting a negative effect on teacher well-being by this policy paradigm. Empirical study of this narrative is largely nonexistent in the literature leaving a need for studies on how controlling policies may interact with teacher well-being. To address this gap in the literature, this study performed 30 semi-structured interviews with public school English and Social Studies teachers in Oklahoma to see how they describe their well-being in a controlling post-pandemic state policy environment. Oklahoma is an ideal setting for this study as its different legislative bodies implemented key curricular controls immediately following the pandemic. Oklahoma is also a state that has struggled with teacher retention, studied achievement, and broader social issues in recent years. The study’s main findings suggest that teachers, regardless of their political persuasion, view state controls over their work as damaging to their well-being. Teachers also described policies designed by people far removed from the daily work of schools more negatively and expressed that such policies may interact more negatively with their well-being. Findings also suggest that leadership characteristics may shield teachers’ well-being from state controlling policies, but that supportive leadership may be insufficient over time in a controlling state policy environment as controls tend to inevitably “trickle down” to the classroom level. These findings may contribute to the literature on the teaching profession by advancing knowledge about how teacher identity and well-being interact with state policies. As such, this work may inform the practice of policymakers and school leaders facing challenges of teacher burnout and shortages
Snakes and Snails or Sugar and Spice? Gender Differences in Studying and Help-Seeking Behaviors in the College Classroom
Get PDFCollege is a time of adjustment, particularly for first-year students. Although many students face challenges, research has suggested an increasing disparity in how well men and women adapt (Moore et al., 2010; Respondek et al., 2019). For example, women earn better grades and have higher retention and graduation rates relative to men (Duffin, 2021; Ewert, 2012; Marrs & Sigler, 2012). Although previous research has focused on gender differences in variables such as help-seeking and study strategies, we hypothesize that masculine identity may be more useful in predicting academic success. The current study employed structural equation modeling (SEM) to determine the influence of masculine ideology as a moderator between academic outcomes and several variables that have previously been associated with academic success, such as mindset, imposter phenomenon, study habits and help-seeking. We found that masculine ideology significantly moderated the relationship between the imposter phenomenon and study strategies such that individuals who experience the imposter phenomenon and also endorse a traditional masculine ideology are more likely to adopt shallow study approaches than those low in traditional masculine ideology, who are more likely to use deep study approaches. Furthermore, masculine ideology significantly moderated the relationship between imposter phenomenon and help-seeking, such that those who endorse a traditional masculine ideology tend to use executive help-seeking methods or avoid help-seeking altogether. However, those who do not endorse a traditional masculine ideology tend to use instrumental help-seeking methods, perceive more benefits from help-seeking, and attend office hours and tutoring more frequently
Identification and Verification of Mesoscale Convective Systems in the Models of the High Resolution Ensemble Forecast System
Get PDFTo better understand the characteristics of storms produced by forecast models and those seen in observations, contiguous and nearly contiguous radar objects with reflectivity above a convective threshold were identified and their shapes analyzed. The area, aspect ratio, orientation angle and maximum reflectivity within the object were calculated. For all members of the High Resolution Ensemble Forecast system, the modeled and observed storm objects had similar distributions in area-aspect ratio space. Modeled storm objects had a preferred band of maximum reflectivity that was not seen in the observed storm objects. The modeled storm objects also had a more north-south orientation than observed. Despite these differences, the shape characteristics of the modeled storm objects were still close enough to modeled storm objects to proceed with the creation of an MCS identification and tracking algorithm. The identification algorithm was based on one developed for MCS identification and tracking of observed storms at the NOAA Storm Prediction Center. A novel tracking algorithm was developed based on continuous swaths of maximum reflectivity and tuned to match expert labeling. Together, the identification and tracking algorithm produced a one year spatial distribution of MCSs that was somewhat consistent with an observed climatology. Additional verification of the identification and tracking algorithm revealed an underforecast from all of the models. At both the diurnal and annual scale, the models generally did not match the shape of the observed distribution. Matching the forecast MCSs with observed MCSs further showed low bias, though the forecasts did have very low FAR. The tuned parameters did not necessarily improve the forecast compared to the default parameters. The positional error between the modeled and observed MCSs showed that when the model produced an MCS, it was usually close to an observed MCS and oriented the same direction as the observed MCS
The Impact of Food Assistance on Labor and Family Outcomes: A Study of SNAP’s Role in Work Incentives and Fertility Choices
Get PDFThe first chapter of this dissertation examines the impact of expanded eligibility for the Supplemental Nutrition Assistance Program (SNAP) on labor supply decisions across U.S. states. Leveraging variation in eligibility expansions over time, it investigates whether the broadened access to SNAP encourages labor force participation and increases hours worked among newly eligible individuals. Contrary to the expectation that SNAP benefits might reduce work incentives, findings reveal an increase in labor force participation on the extensive margin, particularly among groups exempt from work requirements. The study also explores the heterogeneous effects by education level, household type, and enrollment status, as well as by the intensity with which eligibility criteria were relaxed. This analysis contributes to understanding SNAP's role in labor supply behavior, challenging assumptions about welfare benefits and work incentives. The results have implications for policymakers considering eligibility criteria adjustments to improve labor market engagement. The second chapter investigates examines how the Supplemental Nutrition Assistance Program (SNAP) may affect teenage birth rates in the U.S. over the period 2001-2019, since teenage childbearing can have long-term socioeconomic impacts on young mothers and their children. Using data from the Current Population Survey (CPS) and a 2SLS approach, we find that a 1\% increase in SNAP benefits is associated with a 0.11 to 0.14 percentage point rise in teenage birth likelihood. Our findings suggest that SNAP may unintentionally encourage early childbearing by alleviating financial barriers to child-rearing. Additionally, our heterogeneous analysis reveals that the impact of SNAP benefits on teenage birth rates varies significantly across races, census regions, and time periods, with more pronounced effects observed following the Great Recession. We also investigate potential channels through which SNAP influences teenage childbearing and find that SNAP is associated with lower labor force participation, higher unemployment, and negative effects on family formation. Our results emphasize the need to reevaluate social welfare programs to ensure a balance between the economic support provided by SNAP and its potential impacts on fertility choices. The third chapter analyzes the impact of Supplemental Nutrition Assistance Program (SNAP) benefits on the timing of first childbirth among low-skilled women (with births between ages 15 and 40 years), particularly focusing on high school dropouts. Leveraging data from the Current Population Survey (CPS) and a three-way fixed effects model, the analysis finds that a 10\% increase in SNAP benefits is associated with an approximate 1.18-year reduction in the age at first childbirth. This effect is most pronounced among Black women, followed by weaker effects for White and Hispanic women. Regional analysis uncovers significant variation, with the strongest negative effects observed in the Midwest. Notably, the association is particularly strong among White women aged 20–25, where SNAP benefits show the largest negative impact on the age of first birth. Exploring potential mechanisms, the findings suggest that higher SNAP benefits correlate with increased unemployment rates and larger family sizes, indicating that the financial stability provided by SNAP may incentivize earlier childbearing. Additionally, higher SNAP benefits are linked to declines in marriage rates and increases in divorces, separations, and women choosing to remain unmarried, contributing to earlier transitions to parenthood outside stable relationships. These findings highlight the multifaceted ways in which public assistance programs can influence demographic and behavioral outcomes
READY TO BELONG: INVESTIGATING THE IMPACT OF A RESIDENTIAL COLLEGE PREVIEW PROGRAM ON THE CAREER AND COLLEGE READINESS OF STUDENTS WITH INTELLECTUAL AND DEVELOPMENTAL DISABILITES
Get PDFThe primary theme of this dissertation investigates the impact of belonging within a residential pre-college program (e.g.. summer bridge, summer institute, college preview camp program) on the career and college readiness (CCR) of students with intellectual and developmental disabilities (IDD). The program was part of a collaborative initiative between thestate's Department of Vocational Rehabilitation and the university's inclusive post-secondary education program, serving students under the Workforce Innovation and Opportunity Act (WIOA). Data was originally collected as part of a broader program evaluation using a mixed methods format, it is presented here as three separate mini studies, each in its own manuscript.Manuscript 1 employs an inclusive qualitative design using photovoice, where students with IDD, acting as co-researchers, construct definitions of belonging and use evening reflections to consider the camp's impact on the way they think, feel, and believe about their future. Manuscript 2 uses a pre-post survey design to explore the camp’s impact on students' perceptions of their career and college readiness, as well as their sense of belonging. Manuscript 3 presents parental perceptions of the camp’s impact on their children’s career and college readiness. Findings demonstrate the programs’ ability to positively impact CCR in students with IDD, the dynamic and individualized nature of belonging within pre-college programs and hope as common variable in parents of program attender