Digital Commons Network^™

Crop, Soil Nutrient, And Soil Health Responses Within Integrated Crop And Livestock Systems, Alyssa K. Hall

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

We evaluated the influences of grazing livestock on crop production, soil nutrients, and soil health indicators of integrated crop livestock systems using three experiments during a seven-yr. period. Objectives were to (1) determine livestock grazing and cropping system effects on crop yield and soil properties across six yr. in corn-soybean (C-S) and wheat-corn-soybean (W-C-S) systems with and without periodic composted manure application, (2) explore seasonal variation in soil nutrient patterns over two yr., and (3) measure residual responses for corn grain yield plus soil health indicators in yr. seven following a six-yr. study. In experiment 1, neither livestock grazing ( …

How Developers Use Type-System Related Programming Language Features, Samuel W. Flint

School of Computing: Dissertations, Theses, and Student Research

Optional type annotations are a popular feature of programming languages that allow developers to omit explicit type information in code while, in some cases, retaining many of the benefits of static typing, such as in-code documentation, improved detection of type errors, or enforcement of code properties. However, how developers use and understand optional type annotations is not clear. The focus of this dissertation is to understand the use and comprehension of optional type annotations.

Optional type annotations are examined through four lenses: first, by examining the evolution of usage in a statically typed programming language (Kotlin, the default language for …

Detection Of Activity Cliffs Produced By Anti-Cancer Drugs And An Algorithm For Reliable Predictions In Affected Areas, Sarah Josephine Aurit

Department of Statistics: Dissertations, Theses, and Student Research

An activity cliff (AC) occurs when drugs close in chemical space produce dissimilar biological results. We focus on developing an inferential procedure to detect the presence of ACs in a chemical landscape. If detected, we provide a distance-based procedure that can be used to identify regions of stability in the chemical landscape of interest and generate prediction with higher precision in those areas of stability. We conceptualize the chemical landscape as a spatial random field and use spatial models for prediction of efficacy for new drugs based on “distance” in chemical space. We argue that an AC manifests itself by …

Educational Attainment Patterns Among Mena Adults: A Comparative Study Of Native- And Foreign-Born Groups In The Us, Michael Okyere

Department of Sociology: Dissertations, Theses, and Student Research

This study examines educational attainment patterns among Middle Eastern and North African (MENA) adults in the United States, focusing on how nativity status, residential patterns, and gender shape these outcomes. Drawing on segmented assimilation and spatial assimilation theories, I analyze data from the 2018-2022 American Community Survey using ordered logistic regression models. Results indicate that educational attainment varies by gender, with MENA women consistently achieving higher education levels than men across all nativity groups, though this advantage varies considerably in magnitude between native-born and foreign-born subgroups. Residence in ethnic enclaves demonstrates a strong negative association with educational attainment among foreign-born …

Hope Against Hope: Problems, Possibilities, Agency, And Survival, Erin Kay Chambers

Department of English: Dissertations, Theses, and Student Research

In response to a critique of hope put forth by queer theorist Jack Halberstam, this thesis is a reassessment of what makes us capable of response—to “stay with the trouble,” in the words of Donna Haraway—in the face of overwhelming collapse. If not hope, then what? This thesis explores a number of questions about hope and its absence, opposites, and various deployments: is hope always an effective tool for survival? Does hopelessness always spell doom? Are hope and its apparent opposites necessarily incompatible? And if there is no hope, how do we keep going?—how do we survive? I explore these …

Applications Of Preclinical Magnetic Resonance Imaging In The Treatment Of Traumatic Brain Injury And Understanding Carotid Artery Atherosclerosis, Evan Timothy Curtis

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Advances in magnetic resonance imaging (MRI) provide the opportunity to investigate research questions that have been left unanswered. In the cases of traumatic brain injury (TBI) and carotid artery atherosclerosis, MRI is a resource for non-invasively viewing the phenomena taking place. Additionally, potential interventions and treatments can be observed without harm to the subject. This dissertation expands the understanding of two preclinical applications of MRI: traumatic brain injury and carotid artery atherosclerosis in mouse models.

TBI is a leading cause of death and disability for individuals between 15–45 years of age and effective pharmaceutical interventions for treating the secondary damage …

Thematic Analyses Of Session Data With Transgender And Gender Diverse Adults Obtained During A Clinical Trial, Brenna Rose Lash

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Transgender and gender diverse (TGD) adults in the United States experience high rates of discrimination and marginalization, contributing to adverse mental health outcomes. While clinical guidelines for gender affirming care have been developed, these guidelines often lack empirical grounding or specific, actionable strategies for clinicians. Although theoretical models such as the marginalization stress model and the psychological mediation framework offer useful foundations for case conceptualization, they do not fully capture the lived experiences or the resilience mechanisms of TGD individuals in therapeutic contexts. This project aims to bridge the gap between research and clinical practice through thematic analysis of therapy …

Intergenerational Family Dynamics Among Caregivers And Children’S Social-Emotional Development In China, Weiman Xu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The early years of a child’s life are pivotal for social-emotional development. While extensive research has explored the role of family settings in fostering children's social-emotional development (Bornstein, 2005), the impact of grandparental involvement, particularly the caregiving dynamics between generations, remains less well understood. This study aims to fill this gap by examining two critical aspects of intergenerational dynamics among caregivers (i.e. parent-grandparent coparenting and parent-grandparent relationship quality) and their associations with children’s social-emotional development (i.e. social skills and problem behaviors). Two specific aims were delineated: 1) examine the unique contribution of parent-grandparent coparenting, especially the power and authority domain …

The Career Resilience Of Women Of Color Amidst Intersectional Racism-Sexism In The Us: A Consensual Qualitative Study, Hannah Ahmad Ridzuan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Women of color have historically and presently experienced both sexism and racism on interpersonal, institutional, and cultural levels (Sue et al., 2007). While discrimination based on racial-ethnic and gender identities has by far the most extensive literature base (Duffy et al., 2016), literature on the development of women of color career resilience is not as expansive. Informed by the Psychology of Working Theory (PWT) (Blustein, 2006; Duffy et al., 2016), the intersectionality framework (Crenshaw, 1989; Collins et al., 2021), and critical consciousness (Freire, 1971; Quiñones-Rosado, 2020), this consensual qualitative research (CQR; Hill, 2006) explored how women of color in the …

Flooding: Risk Assessment And Its Interaction With Population & Environmental Health, Shivendra Srivastava

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Flood events have significant implications for both population and environmental health. This dissertation aims to explore flood risk and its interaction with humans and the environment. The key questions addressed in this dissertation include improving the existing flood risk framework to better assess population vulnerability and associated risk. Additionally, it explores how interactions among risk components vary across spatial scales and regions, and how these variations influence overall flood risk. The dissertation also investigates how to design a vulnerability component specific to flooding within flood risk estimation. Finally, it answers whether flood-specific vulnerability differs for a population compared to vulnerability …

The Tree That Would Not Fall: An Educator’S Autoethnographic Journey Of Healing Through Words, Raeanna Marie Carlson

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

To say the world has changed since the 2020 COVID-19 shut down is to minimize the micro and macro social changes that infiltrated the school system. In the wake of it all, we find a landscape marred by a both rising teacher attrition and struggling student motivation. This autoethnographic dissertation explores the deeply personal experience tethered to a deeply problematic system that contributes to not only teacher burnout but what I came to know as teacher demoralization. Personal traumas of teachers profoundly impact their experience in the classroom, and as I examined my own near departure from the classroom, I …

Ferroelectricity And Multiferroicity In Ultrathin Films Of Unconventional Transition Metal Oxide, Xin Li

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ferroic orders of transition metal oxides, such as ferroelectricity and ferromagnetism, are determined by the intercoupling between spin, charge, lattice. Consequently, ferroic epitaxial thin films have attracted wide interest due to the profuse novel phenomena and the great application potentials for modern electronics. However, the mainstream of the study for transition metal oxides has focused on perovskite structure, limiting the understanding and discovery of novel phenomena associate with ferroic orders. In this thesis, the epitaxial films of hexagonal rare-earth ferrites (h-RFeO₃) and fluorite-structure hafnia oxide (HfO₂) are studied comprehensively, providing new experimental and theoretic …

Understanding The Dynamics Of Formal Mentoring In Professional Identity Development Of Early Career Extension Professionals: A Phenomenological Approach, Anuradha Choudhary

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

Formal mentoring plays a crucial role in shaping the professional identity of early-career extension professionals; however, limited research has explored how these dynamics affect professional identity development within formal mentorship structures. This study uses a transcendental phenomenological approach to understand how mentees and mentors perceive the impact of formal mentoring on professional identity development within the Nebraska Extension system. Using criteria-based random sampling and snowball sampling, the study engaged 10 mentees and 10 mentors, employing semi-structured interviews, focus groups utilizing ripple effect mapping, and document analysis of mentoring agreements, program guidelines, and mentoring checklists. Following Moustakas' (1994) transcendental phenomenology framework, …

Between Two Worlds: A Case Study Of Third Culture Identity And Reentry For Unl International Students, John S. Tessalee

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

Third Culture Kids (TCKs) and international students share many commonalities, such as their globalized nature, adaptability, and the adoption of cultural components from their host country versus their home country. However, they contain enough differences to be considered separate groups. Traditionally, people need to be immersed in a culture different from their parents’ culture between the ages of 0 and 18 to be considered a TCK, whereas international students are typically between 18 and 24 years old by the time they attend universities overseas. The cultural absorption of TCKs in their formative years is usually greater than that of international …

Exploring The Landscape Of Collective Leadership Practice In Rural Nebraska: A Qualitative Sequential Multimethod Study, Haden Myles Botkin

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

Rural communities across Nebraska face a myriad of complex challenges that cannot be solved by individual, heroic leaders. As such, collective leadership has begun to emerge in these communities as actors coalesce around local issues. However, little is known about collective leadership practice and development in rural contexts, resulting in a theory-to-practice gap. To that end, this qualitative sequential multimethod study sought to explore how rural community leaders and community development educators perceive, describe, and make meaning of collective leadership practices in rural Nebraska. Three phases comprise this study.

Phase I, the QUAL phase, was guided by the question, How …

A Multi-Isotope Investigation Of Mammoth Diet, Habitat, And Movement Patterns In The Central Great Plains, U.S.A., Jacob Mccloskey

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

During the Last Glacial Maximum (LGM), the Great Plains in Nebraska consisted of wooded parklands and grasslands, whereas spruce (Picea) forests, parklands, and steppe grasslands dominated east of the Missouri River. I analyzed bulk carbon (δ¹³C), oxygen (δ¹⁸O), and strontium (⁸⁷Sr/⁸⁶Sr) isotopes from tooth enamel in isolated mammoth (Mammuthus) molars to compare diet and movement patterns in two late Pleistocene assemblages: one in Nebraska (n = 24), and one in western Iowa and Missouri (n = 17). Furthermore, I identified a morphometric subset of molars as …

Low-Level Polarimetric Signatures Of Supercells During Ef3+ Tornado Production, Anthony Noah Began

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Most EF3+ tornadoes are produced by supercells. Understanding of microscale features surrounding intense tornado production remains limited. This research aims to determine commonalities in low-level microphysical processes during intense tornado production via polarimetric radar signature assessment with a Python-based algorithm. Polarimetric variables hypothesized to reflect low-level wind profiles such as the differential reflectivity (Z_DR) arc and the Z_DR–K_DP (specific differential phase) separation vector will be investigated. Supercells which produced EF3+ tornadoes will be examined since these tornadoes pose the highest threat. From 2010 to 2024, the United States recorded approximately 19,100 tornadoes which resulted in …

Adolescent Online Leisure, Media Literacy, Online Victimization, And Multifaceted Well-Being During Covid-19: The Role Of Parental Support, Yunqi Wang

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The rapid advancement of the internet and digital technology has provided opportunities for adolescents to conduct leisure activities online on a daily basis. However, research on adolescent technology use and mental health often highlights negative effects without carefully examining the specific mechanisms, which overlooks the complexity of effects of online behaviors on adolescent well-being and the importance of developing adolescents’ media literacy skills. Moreover, despite the crucial role of family dynamics in adolescent development, research on how parental support and involvement might affect adolescent technology use and well-being is still limited. The current study retrieved data from Programme for International …

Study Of Ai Applications In Biomedical Data Acquisition, Communication, And Analysis: Cest Mri Acceleration And Ecg Transmissions, Adarsha Bhattarai

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation investigates the application of artificial intelligence in biomedical data acquisition, communication, and analysis to advance neurological research and to enable the early detection of cardiovascular conditions. Despite significant advances in imaging and physiological modalities, challenges persist. Imaging modalities, such as the chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) technique are challenged by a prolonged data acquisition time and high operational costs. In addition, physiological modalities such as electrocardiogram (ECG) sensors face constraints in providing uninterrupted signal monitoring which is crucial for the timely detection of premature cardiac abnormalities. The primary goal of this work is to …

Evaluation Of Performance Characteristics And Groundwater Contamination Risks Associated With On-Farm Swine Carcass Disposal Via Composting And Shallow Burial With Carbon, Gustavo Castro Garcia

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation evaluates the performance of three on-farm swine carcass disposal methods: whole carcass composting (WCC), ground carcass composting (GCC), and shallow burial with carbon (SBC), focusing on biosecurity factors and groundwater contamination risks. Foreign animal diseases (FADs), such as African swine fever and classical swine fever, pose severe economic and animal well-being risks if introduced to the United States. With confirmation of an FAD, swine movement will be halted, creating an urgent need for practical, biosecure, and environmentally responsible on-farm disposal strategies for swine carcasses. Nebraska, as a leading swine-producing state, exemplifies the vulnerability of high-density livestock regions to …

Online Prediction Of Streaming Data, Aleena Chanda

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

We present two new approaches for point prediction with streaming data based on a) the Count-Min sketch and b) Gaussian Process Priors with random bias. The methods are intended for the most general case where no true model can be usefully formulated for the data stream. In statistical contexts, this is often called the M open problem class. For the Count Min Sketch method we show that the predicted distribution function ^F converges to F under the assumption that the data consists of i.i.d samples from a fixed distribution function F. To implement the Gaussian Process Prior methods, we used …

Mass Effects On Energy Transfer Paths In Nonlinear Vibrating Systems, Manal Mustafa

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation examines the role of mass in nonlinear systems, uncovering its role in enabling passive energy redistribution and robust vibration control in both idealized and real-world structures. Focusing on a strongly nonlinear two-degree-of-freedom system, it investigates how changes in mass ratio influence the dynamics of energy transfer, nonlinear normal modes (NNMs), and dissipation behavior.

A number of significant contributions are introduced in this work beginning with the introduction of the frequency-energy-peaks (FE-pks) plot, a novel tool that visualizes how energy flows through the system, revealing transient resonance orbits, internal resonance effects, and effectively capturing the different nonlinear phenomena with …

Hormonal Modulation Of Sexual Approach And Avoidance Among Women With A History Of Sexual Trauma, Anneliis Susan Sartin-Tarm

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

A history of sexual trauma places women at a high risk for sexual dysfunction and other health sequelae, yet the influence of ovarian hormones in this population is poorly understood. This dissertation tested the theory that the effects of ovarian hormones are mediated by cognitive approach-avoidance systems to shape sexual well-being, and that this process is moderated by sexual trauma history. This was investigated across three studies examining the menstrual cycle, hormonal contraceptive use, and menopause. Across each chapter, I present complementary evidence demonstrating that hormones interact with the interpretation of ambiguous internal and external cues with respect to sexual …

Reductive And Nucleophilic Cleavage Of Peroxides And Synthesis Of Tocotrienols As Radioprotective Targets, Amber Marie Schuster

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

I. SET CLEAVAGE OF PEROXIDES: INFLUENCE OF REDUCTANT AND PEROXIDE ON THE RATE AND MODE OF ALKOXY RADICAL FORMATION

The reductive cleavage of organic peroxides to generate alkoxy radicals is frequently accomplished via single-electron transfer (SET) from a reductant. Previous reports employ either symmetrical peroxides or peroxides with predictable cleavage behavior, such as peresters. We were interested in how the structure of the peroxide and the nature of the reducing system combine to impact the rate of reaction and the selectivity for alkoxy radical formation during cleavage of unsymmetric peroxides. In this dissertation, one will find the reactions of a …

A Phenomenological Study Of Rural Immigrants And Their Experiences Of Community Leadership, Jian Ju Yeo

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The turn of the 21st century has seen a new settlement pattern of immigrants bypassing traditional urban gateways and locating to rural spaces instead. Rural immigration presents a unique opportunity to advance the vitality of small towns as the development of communities is best served by a fully networked and integrated community. The purpose of this transcendental phenomenological study was to examine the experiences of rural immigrants with community leadership. Research questions focused on how rural immigrants perceive, identify with, and access their local community leadership. Through one-on-one interviews, 10 participants provided rich qualitative data that were analyzed to yield …

Chronic Pain After Traumatic Brain Injury: Treatment Experiences And Effects On Cognition And Functioning, Rachael L. Snyder

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Traumatic brain injury (TBI) can contribute to changes in cognitive and emotional functioning, quality of life, and psychosocial reintegration. Chronic pain is a common consequence of TBI which can uniquely impact such outcomes. Still, the exact nature of the contribution of pain on post-TBI outcomes remains unclear, and there are few existing studies exploring the treatment journey for chronic pain and injury rehabilitation through qualitative methods, specifically individual interviews with TBI survivors. This study aimed to document these narratives and to identify precisely how the experiences of TBI survivors seeking treatments, rather than the treatments themselves, impact outcomes. It also …

How Developers Use Type-System Related Programming Language Features, Samuel W. Flint

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Optional type annotations are a popular feature of programming languages that allow developers to omit explicit type information in code while, in some cases, retaining many of the benefits of static typing, such as in-code documentation, improved detection of type errors, or enforcement of code properties. However, how developers use and understand optional type annotations is not clear. The focus of this dissertation is to understand the use and comprehension of optional type annotations.

Optional type annotations are examined through four lenses: first, by examining the evolution of usage in a statically typed programming language (Kotlin, the default language for …

Dreaming, Building, And Enduring Black Voices: Black Media In Omaha In The Post-Civil Rights Era, Elodie C. Galeazzi-Kelly

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation examines the purposes and roles of Black media in Omaha during the post–Civil Rights Era. It asks how African Americans and their allies in Omaha developed innovative media forms, institutions, and communication strategies to amplify Black voices, build community, and advocate for Black interests amid the rapidly shifting political and social landscape of the time. The study focuses first on three traditional forms of media (newspapers, radio, and television) and then broadens the definition of media to include key Black cultural institutions. These include a dramatic arts collective, a historical museum and archive, a memorial foundation, and an …

Where Intangibles Travel: Essays On The Tax-Motivated Geography Of Innovation And Capital, Xuerui Kou

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation explores how taxation and institutional environments shape the global strategies of United States multinational enterprises (MNEs), with a particular focus on intangible assets and the cross-border allocation of innovation. Positioned at the intersection of international trade, public economics, and innovation studies, the three chapters collectively examine firm responses to international tax incentives and regulatory asymmetries.

Chapter 1 introduces the motivation and theoretical foundations of the dissertation, reviews related literature, and outlines the core research questions and empirical strategies. It highlights the increasing policy and academic interest in the geographic mobility of intangible capital, particularly in the context of …

Resilience Of Interdependent Transportation And Healthcare Systems: A Simulation-Driven Framework Incorporating Social Equity And Facility Optimization, S. Yasaman Ahmadi

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The overarching goal of this dissertation is to develop an integrated, simulation-driven framework to assess and enhance the resilience of interdependent transportation and healthcare systems before, during, and after natural hazards. By examining how spatial disruptions, social vulnerability, operational constraints, and infrastructure interdependencies affect access to and functionality of hospitals, this research offers a multifaceted evaluation of system performance under stress. This dissertation examines the impact of natural hazards, particularly floods, on the interdependent transportation and healthcare systems. The proposed approach combines and advances GIS-based network analysis, graph-theoretical modeling, and discrete-event simulation to evaluate system performance under different scenarios. The …