Digital Commons Network^™

Surveys And Modeling: Using An Existing Survey To Describe And Compare Populations To Better Inform On Groundwater Model Inputs, M. Austin Wise

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

The Mississippi River Valley “Alluvial Aquifer” is among the most agriculturally significant aquifers in the United States. However, parts of the aquifer are exceeding sustainable yield as development of the water source continues. Survey research in other aquifers, such as the High Plains (Ogallala) Aquifer, has helped to understand the perceptions and attitudes of irrigators withdrawing from their aquifers. This led to numerous questions: What are the attitudes of irrigators in the Alluvial Aquifer region? How do they compare to irrigators in other regions of the country? Can their intentions be used to generate more accurate inputs when modeling adoption …

Exploring The Application Of Repeated Microgravity Surveys To Monitor Groundwater Level Variations In Nebraska, Kaitlin M. Steinauer

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

Groundwater is an important resource in the state of Nebraska for supporting industries and ecosystems. Monitoring this vast resource ensures its continued availability for generations to come. However, monitoring utilizes well data, and if a well is not present in a desired location, geophysical methods can be explored. This project tests the capability of repeated gravity surveys over Nebraska’s aquifers to monitor groundwater levels throughout 2024.

Two study areas were selected in Eastern Nebraska. The first is in Oakland, Nebraska, over a confined aquifer system. The second is in Plymouth, Nebraska, and exhibits unconfined conditions. Four sites were chosen to …

Exploring Racial Identity Among East And Southeast Asian Transracial Adoptees In The United States Through Communication Theory Of Identity, Brooke Marie Hoá Hornberger

Department of Communication Studies: Dissertations, Theses, and Student Research

The purpose of this study was to understand how East and Southeast Asian transracial adoptees (ESATA) in White adoptive families conceptualize and communicate their racial identity. ESATAs endure various challenges surrounding race that makes it important to understand how ESATAs understand their racial identity, the tensions they might experience, and how they management the tensions surrounding racial identity. Using the theoretical framework Communication Theory of Identity (Hecht, 1993), 25 ESATAs were interviewed about different frames of identity and potential identity gaps they experience surrounding racial identity. In addition, ESATAs were asked about how they communicatively manage identity gap tensions mapping …

Aptamer Selection And Development Of Electrochemical Aptamer-Based Sensors For Neuropeptide Y, Evelyn Adela Carreto Guevara

Department of Chemistry: Dissertations, Theses, and Student Research

In this thesis, we report the results of four aptamers obtained from an aptamer selection process called the systematic evolution of ligands by exponential enrichment (SELEX) with affinity to Neuropeptide Y (NPY). NPY is a highly abundant peptide transmitter with widespread distribution throughout the body which affects various physiological functions. These functions include energy homeostasis, appetite regulation, stress response, and anxiety regulation. Dynamic monitoring of NPY levels is crucial for better understanding behaviors in individuals with neurological disorders associated with NPY. Aptamers are synthetic oligonucleotides obtained through SELEX which have a binding affinity to a target of interest when in …

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 …

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 …

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 …

Improved Rumen Microbiome Interpretation Via Empirical Filtration Derived From Known Mock Microbiomes, Wesley A. Tom

School of Biological Sciences: Dissertations, Theses, and Student Research

The rumen microbiome plays a critical role in ruminant health and performance. As a consequence, many studies investigate microbial community composition using 16S rDNA based sequencing. As such, data quality and data filtering are critical to accurately identify microbial community composition. In this study we use mock communities to empirically select data filtering parameters to reduce artifact populations and compared the effect of filtering using different bioinformatic pipelines using rumen bacterial community data. The filtering parameters identified provides consistent estimates of rumen microbial diversity, regardless of bioinformatic pipeline utilized and provides a more accurate view of microbiome structure and composition. …

Non-Blackbox Robust Design Of Machine Learning In Networks, Venkat Sai Suman Lamba Karanam

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

Networked systems have become increasingly complex, with newer communication technologies and standards being added every day. Machine Learning (ML) and Artificial Intelligence (AI) paradigms have been adopted in networks to not only solve many fundamental problems, but also to allow seamless integration of components comprising them. The saying “let’s not reinvent the wheel” in ML/AI adoption implies that model architecture design be left for pure ML/AI researchers, while network researchers focus on input preprocessing (e.g. formatting the packet data to be fed to a model), hyperparameter fine-tuning and a trial-and-error approach to find the “best” result. …

Authentication And Message Integrity Verification For Emerging Wireless Networks, Ebuka Philip Oguchi

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

This dissertation presents a comprehensive body of research on authentication and message integrity verification for emerging wireless networks, focusing on secret-free and physical layer security techniques across diverse, challenging, and unconventional environments.

It comprises four first-author contributions that span underground wireless systems, over-the-air (OTA) channels, vehicular communications, and nanoscale molecular networks.

The first contribution, Soil-Assisted Trust Establishment for Underground Wireless Networks (STUN), introduces a physical-layer trust bootstrapping protocol that achieves authentication and message integrity without pre-shared secrets. Leveraging underground-to-air propagation laws and trusted relay nodes, STUN resists active signal injection attacks and demonstrates security comparable to the unbalanced oil and …

Carrying Light In The Shadows: Four Portraits Of Critical Literacy Teacher Agency In Unlikely Contexts, Cassandra Schroeder

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

This qualitative study utilizes portraiture methodology to explore how educators in politically conservative and predominantly White schools enact critical literacy teacher agency. Using a theoretical lens of critical literacy and second-wave Whiteness studies, this research examines the lived experiences and instructional moves of four veteran English/language arts teachers. Through cross-case analysis, the study traces how teacher agency is contextually responsive and dependent on their professional identity, awareness of sociopolitical issues, and traditional school curricular expectations. The findings highlight how educators assess risk, navigate community norms, and maintain critical literacy through dialogic pedagogy and strategic adaptation. The four teachers in the …

Rhetorics Of Encounter: Toward A Biocentric Theory Of Discourse, Matthew D. Whitaker

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

Encounters with more-than-human identities are transformative moments that stand to affect dispositional and bodily change in individuals. From close brushes with wild animals in National Parks to everyday interactions with local ecologies, encounters invite us to feel and think differently about the nature of our realities. In Rhetorics of Encounter: Toward a Biocentric Theory of Discourse, I draw from interdisciplinary perspectives to disrupt the idea of rhetoric as a representational medium, arguing that rhetoric occurs not just through textual exchanges of words and symbols, but through embodied moments of contact with other responsive beings. Invoking George Kennedy’s theory …

Development And Evaluation Of Supported Ionic Liquid Membrane And Porphyrin Frameworks For Carbon Capture Separation, Sarang Ismail

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

The global urgency to mitigate anthropogenic CO₂ emissions has intensified the pursuit of energy-efficient separation technologies. Supported Ionic Liquid Membranes (SILMs) have emerged as promising candidates for CO₂ capture due to their tunable solubility-selectivity and low energy requirements. However, challenges such as mechanical instability, limited scalability, and trade-offs in transport performance have impeded their widespread adoption.

This thesis explores a systematic approach to designing and optimizing SILMs for enhanced CO₂ separation by tailoring polymer–ionic liquid interactions, processing conditions, and material architectures. A comprehensive set of studies were conducted using poly(vinylidene fluoride) (PVDF) with varying molecular weights, different grades of PEBAX®, …

Multivariate Mixture Regression Models With Known Group Membership And Informative Priors, Pahalapathirage Dona Kalani Hasanthika

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

We introduced couple different novel approaches to incorporate latent variable information to multivariate mixture regression models with both Gaussian and count data. We also evaluated the performance of these models with existing best approaches with simulated data from various sampling structures and also evaluated one of the models performance with rice metabolite data that provided some novel insights as well as validating existing literature about performance and behavior of these metabolites. We validated the method using extensive simulations and a real-world application. In both quantitative covariate designs and complex treatment design simulations, our method consistently outperformed established tools like limma, …

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 …

Plant Nutrient Interactions In High-Yielding Soybean Environments, Victoria Inklman

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

Plant nutrient demands and limitations are usually studied individually by nutrient. Here, we investigated how nitrogen (N) limitation in high-yielding soybean environments affects the uptake, removal, and residual of other plant macro- and micronutrients. The objective of this study was to quantify the uptake, removal, and residual levels of soybean macro- and micronutrients under N-limited conditions and to identify nutrient priorities for high-yielding soybean systems. Aboveground plant samples at physiological maturity were collected in 19 high-yielding soybean fields with N limitation across the state of Nebraska. Reference plots with ample N supply were included within each field to compare macro- …

Interpolation In Weighted Projective Spaces, Shahriyar Roshan Zamir

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

Over an algebraically closed field, the double point interpolation problem asks for the vector space dimension of the projective hypersurfaces of degree $d$ singular at a given set of points.

After being open for 90 years, a series of papers by J. Alexander and A. Hirschowitz in 1992–1995 settled this question in what is referred to as the Alexander-Hirschowitz theorem. In this thesis, we use commutative algebra to prove analogous statements in the weighted projective space, a natural generalization of the projective space.

A main contribution of this work is the careful adaption of several classical algebro-geometric techniques to the …

Don't Settle For Less: Incorporating Postcolonial And Settler Colonial Perspectives Into The Sociological Canon, Eli Xavier Ornelas

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

For decades now, post-/de-/settler-/ and anticolonial scholars have advanced the argument that sociology has largely failed to incorporate critical insights from theories of empire into the sociological canon. In this dissertation, I argue that introduction to sociology textbooks offer an important vantage point from which to assess conventional sociological knowledge as textbooks are often thought to be “reflections of the discipline.” I analyze the social theory and race chapters of 21 of the most often used introduction to sociology textbooks in the United States to investigate two chapters where insights from theories of empire would be present if indeed incorporated: …

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 …

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 …

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 …

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 …

On Kernels And Antiderivatives Of Nonlocal Derivatives, Alex John Heitzman

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

Nonlocal operators are mathematical operators taking functions to other functions f → Df , where to evaluate the operator Df at a point x, one must know the value of f in some region around x, and that region cannot be arbitrarily small. Nonlocal derivatives are like derivatives in that they measure the deviation of a function f(z) from f(x) when z is close to x. In this thesis, we will study nonlocal operators of the form

D_kf(x) = [integral]_Ω [f(x) …

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 …

From Classroom To Content Creator: Leadership Practices And Identities Of Female Science Teachers On Tiktok, Rachel M. Benzoni

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

This qualitative multiple case study investigates how four secondary science teachers use TikTok to advocate for science education and how content creation shapes their professional identities as leaders. Using interviews and video content with a framework integrating constructivist leadership, Leader Identity Construction Theory (LICT), and the Social Change Model (SCM), findings show participants enacted leadership outside formal roles through distributed and relational practices leveraging social media's affordances. Five themes emerged from the analysis: (1) Reconceptualizing Teacher Leadership on Social Media, (2) Leadership Through Equity-Driven Practice, (3) Constructing and Leading in Online Professional Learning Communities, (4) Forming and Negotiating Identities in …

“Self-Compassion Has To Be The Heartbeat Of How I Move Through Life”: A Mixed Methods Study Of Family Caregiver Emotional Well-Being, Sarah O. Rasby

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

Often referred to as “hidden patients,” family caregivers endure numerous physical, emotional, psychological, and social hardships due to the demands of caregiving, which often results in their own needs going unmet. With the projected 61.3 million of the baby boomer generation entering the long-term care phase by 2029 along with a mass shortage of professional caregivers post-pandemic, more and more family members are expected to fill in for the role of care without sufficient access to support services (Pollard & Scommegna, 2014; Smith & Chang, 2016). An exploratory, mixed-methods study using a three-group intervention design was utilized to investigate the …

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 …

The Earliest University Of Nebraska Graduate Degrees, 1886-1909, Mark A. Griep

Mark A. Griep Publications

This list of the earliest graduate degrees awarded by the University of Nebraska (NU) in Lincoln was assembled to learn about the university’s research activity that preceded its admission to the prestigious Association of American Universities (AAU) in 1909.