Digital Commons Network^™

Analysis Of Vision Transformers And Domain Adaptation In Long-Range Facial Recognition, Zachary Michael Swanson

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Atmospheric turbulence presents a significant barrier to long-range facial recognition, introducing severe geometric distortions and blur that degrade image quality. This thesis investigates deep learning approaches for mitigating these effects, with a focus on transformer based architectures and domain adaptation strategies.

An in-depth benchmarking study was performed using convolutional neural networks (CNNs) and vision transformers (ViTs) on the Husker BRIAR Research Collection from up to 500m (HBRC-500) face dataset. The results demonstrated that vision transformers, particularly hierarchical vision transformers like the shifted-window (Swin) transformer, outperform CNN-based models at long distances due to their ability to model global spatial relationships and …

Biocomputing Approach To Modeling And Modulating Calcium Signaling, Sehee Sun

School of Computing: Dissertations, Theses, and Student Research

Biocomputing is an emerging field that seeks to perform computational tasks using biological substrates and processes. Unlike conventional computing systems based on silicon hardware, biocomputing leverages the parallelism, energy efficiency, and complex dynamics of living systems. Among various cellular mechanisms, calcium (Ca2+) signaling stands out as a central regulator of diverse biological functions, offering a promising basis for programmable logic and control in living cells.

This thesis introduces a novel framework for modeling and modulating Ca2+ dynamics using biologically inspired Boolean logic circuits. Specifically, we propose the Ca2+ Boolean Logic (CaBL) model, in which Ca2+ fluxes and interactions are abstracted …

Cazyme Gene Cluster Diversity In Human Gut Microbiome, Yi Xing

Department of Food Science and Technology: Dissertations, Theses, and Student Research

In gut microbiome research, carbohydrate-active enzyme gene clusters (CGCs) have emerged as key functional units for understanding microbial glycan degradation. Unlike taxonomic or broad pathway annotations, CGCs offer gene-cluster-level resolution and capture substrate-specific microbial functions. However, their diversity and distribution in relation to host metabolic phenotypes, such as obesity, remain poorly characterized. This study tests the hypothesis that the composition and abundance of fiber-targeting CGCs vary between obese and healthy human gut microbiomes, reflecting distinct microbial carbohydrate utilization strategies. To examine this, we constructed a high-quality reference CGC dataset comprising 94,019 clusters from the Unified Human Gastrointestinal Genome and profiled …

Response Of Soybean To Variable Irrigation Levels In Eastern Nebraska Using The Aquacrop Model, Anmol Singh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

AquaCrop was calibrated and validated for soybean [Glycine max (L.) Merr.] using 19 irrigation treatments from five years using data from field experiments. The model accurately simulated canopy cover (CC), soil water content (SWC), and grain yield, with overall validation nRMSE values of 12%, 7%, and 7%, respectively. The overall validation nRMSE for SWC in individual 30-cm soil layers was comparatively higher, at 19%. The model was subsequently applied for long-term simulations (2010–2024) to estimate soybean yield and water requirements for two dominant soil types, Yutan silty clay loam and Tomek silt loam under three irrigation levels - rainfed, …

Overcoming Maternal Antibody Interference In Swine Influenza: Advancing Dna Vaccine Strateies For Enhanced Immune Protection In Piglets, Danh Cong Lai

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Maternally derived antibodies (MDAs) play a vital role in protecting neonates from infectious diseases, but their presence at the time of vaccination can interfere with vaccine-induced immune responses, thereby reducing vaccine effectiveness. MDA interference has been documented in pigs vaccinated with whole inactivated virus (WIV) vaccines against swine influenza A virus (IAV). In this thesis, we evaluated the efficacy of a lipid nanoparticle encapsulated DNA (LNP-DNA) vaccine against swine IAV in the presence and absence of MDAs, comparing it to a WIV vaccine. In MDA-negative piglets, both the LNP-DNA and WIV vaccines induced strong immune responses and effectively prevented the …

Exploring And Characterizing Organic Chemistry Students’ Meaningful Engagement In Science Practices, John Zhou

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

Undergraduate organic chemistry frequently engages students in key science practices such as analyzing and interpreting spectroscopic data and constructing explanations through reaction mechanisms. However, these activities are often framed as procedural tasks rather than as tools for constructing knowledge. As a result, students may develop incomplete understanding of these practices, making it harder for them to see how scientific knowledge is generated and to use them meaningfully as tools for sensemaking. To better understand how students take up these practices as epistemic tools, three qualitative studies were conducted in this dissertation to investigate how undergraduate organic chemistry students reason with …

A Uas-Centered Investigation Of Vorticity Characteristics And Cold Pool Structure Across Forward And Left-Flank Boundaries In Supercells, Mark R. De Bruin

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

Supercell internal boundaries are the locus of tornadogenesis; thus, understanding the characteristics of these boundaries, particularly in terms of vorticity, is important for identifying the role they play in tornado formation. Insight into the overall characteristics of internal boundaries and their possible role in tornadogenesis have been driven by studies reliant on numerical modeling-based experiments. Observational studies often neglect above-surface conditions or, when these observations are made, lack the spatial resolution to resolve boundary characteristics. During TORUS (Targeted Observation by Radars and UAS of Supercells) 2019 and TORUS-LItE (TORUS Left-flank Intensive Experiment) 2023, uncrewed aircraft systems (UAS) and mobile mesonets …

The Lived Experience Of Religious Trauma Among Transgender And Gender Diverse People: An Interpretative Phenomenological Analysis, Patrick T. Meyer

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Religion has served as a framework to support the psychological well-being of people across cultures throughout human history, yet there is growing scholarly and public interest in how religious institutions and people inflict harm on members through spiritual means. Extant literature demonstrated that transgender and gender diverse (TGD) people experience gendered microaggressions in religious spaces, and their social position within the church likely holds unique insights into the subjective experience of religious trauma. Even though research with people who have had adverse religious experiences has increased over time, little is known about TGD people who experience lasting psychological damage due …

Development And Implementation Of A Vector-Quantized Transformer Autoencoder For Monitoring Bicycle Road Conditions, Kewei Ren

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Adviser: Chun-Hsing Ho

The long-term, sustainable assessment of bicycle road conditions is essential for ensuring cyclist safety and promoting equitable infrastructure management. While traditional detection methods based on manual thresholds have demonstrated some effectiveness, they carry limitations due to the diversity of pavement materials, cyclist behaviors, and sensor platforms. Although recent advances in deep learning offer promising alternatives, established techniques are primarily applied to highway anomaly detection and are rarely adapted for bicycle roads. Furthermore, most related studies lack clear definitions for anomalies and transparent annotation procedures, resulting in a shortage of effective datasets and detection methods specifically for bicycle …

Feasibility Of Using Recycled Waste Plastic In Concrete Pavements In Nebraska, Amasi Hajahja

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Waste plastic (WP) is a growing environmental concern due to its non-biodegradable nature, large-scale production, and harmful impact on natural resources. With nearly 75% of WP in the United States ending up in landfills, effective recycling strategies are urgently needed. In parallel, the limited availability of natural aggregates highlights the need for alternative materials in concrete construction. This study investigates the feasibility of using recycled waste plastic (RWP) in concrete mixtures, both as aggregates and fibers for rigid pavement applications in Nebraska. Concrete mixtures were prepared by partially replacing natural fine aggregates with recycled plastic aggregates (RPA) at replacement levels …

Extracting From The Extracurriculum: Using Extracurricular Composition Practices To Bring Purpose, Voice, And Engagement Back To The English Classroom, Grace N. Ellis

Department of English: Dissertations, Theses, and Student Research

This thesis explores how principles and practices from extracurricular literacy spaces and the extracurriculum as a whole can inform and revitalize the secondary English classroom. In response to growing student disengagement, apathy, and disconnection, particularly within highly standardized and product-focused classrooms, this argument investigates how programs such as the Nebraska Writers Collective’s All Writes Reserved program and the University of Nebraska–Lincoln’s Young Writer Camp model authentic engagement, identity exploration and development, and rhetorical agency through creative, student-centered writing practices. Drawing from composition theory, educational research, and experiential data from Nebraska-based writing initiatives, the thesis argues that incorporating choice, safe-risk taking, …

The Effect Of Individual Variation On Epidemiological Dynamics: From Super-Spreaders To Landscapes Of Risk, Alexis Shannon Beagle

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

Individuals that make up a population always display some level of variation between members. At the smallest scale, individuals always maintain genetic variation, but variation continues to arise at other scales of biological organization from physiological or immunological variation within individuals to variation in behavior between individuals that can be both genetically and environmentally mediated. The role of individual variation is particularly important in the context of infectious diseases because there is strong evidence that infections are highly heterogenous, indicating that patterns of individual variation drive a significant portion of the epidemiological patterns we observe. Individual variation leads to heterogeneity …

Use Of High-Throughput Phenomics With And Without Fungicide As A Wheat Breeding Tool, Gerardo Ivan Rivera Collazo

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

Wheat (Triticum aestivum) is an important food staple for many countries around the world and current consumption and production data demonstrate a production deficit. Breeders are challenged to help close this gap in production by selecting better cultivars with improved yields. Several methods aim to accelerate the breeding process to reduce the time required for releasing an elite variety. One of the main breeding bottlenecks is the lack of fast and reliable phenotypic data acquisition that could dissect physiological and morphological plant data. High-throughput remote sensing could have the potential to reduce this bottleneck by streamlining data acquisition, …

A Study Of Ice And Fire: Environmental Change Impacts On Lakes Of The Nebraska Sandhills, Daniel Gschwentner

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

The Nebraska Sandhills contain thousands of shallow, groundwater-fed lakes. These lakes are extremely sensitive to environmental and climatic changes due to their isolated hydrological setting and small volume. Building on previous work on the hydrology, geochemistry and long-term climate response of Sandhill lakes, my research considers how ecosystem processes such as primary production, nutrient limitation and water quality respond to short-term environmental and climatic change. In my first data chapter, I highlight that Sandhill lakes are nitrogen (N) but not phosphorus (P) limited and that N:P ratios are poor predictors of nutrient limitation status in Sandhill lakes. In my second …

A Modular Paradigm For The Directly Efficient Representation Of Kinetic Laser-Driven Plasmas, Roland D. Hesse

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

A natural inefficiency in conventional treatment of the plasma distribution arises from indiscriminate consideration of the contributions to field structure that are dynamically sourced from kinetic activity in disparate sectors of phase space. We introduce a range of techniques for model design to maximize representation efficiency without breaking key physical invariants indicative of physical reliability. An overview of varied adaptation to stable time-advance methods is given. Low-dimensional representation of a laser-driven plasma requires some creativity in differential structural modification, while direct efficiency is uncovered through the compression and rarefaction of a nonuniform momentum grid. These numerical models introduce embedded gains …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

School of Natural Resources: Dissertations, Theses, and Student Research

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …

Bioenergy Crop Production: Implications For Grassland Bird Communities In Southwestern Nebraska, Grace E. Schuster

School of Natural Resources: Dissertations, Theses, and Student Research

Biofuel and bioenergy systems are components of most climate stabilization pathways to reduce greenhouse gas emissions and limit global warming. Currently, corn (Zea mays) is the predominant feedstock used for bioenergy production in the United States. However, widespread production of this monoculture crop has resulted in many negative environmental impacts. The most notorious impact has been the loss of grassland habitat due to agriculture expansion which has had detrimental effects on wildlife that depend on grassland habitat. One such group, grassland birds, has faced steeper, more consistent, and more widespread declines than any other avian guild. Therefore, strategies …

Primary Investigation Of Rice-Fish Co-Culture: Investigating The Feasibility Of Raising Fish In Flooded Rice Paddies In The Southern Usa, Yulin Jia, Aaron K. Jackson, Bartholomew Green, S. Adam Fuller, Heather Box, Laduska Sells, Candis Ray, Paxton Harper, Brennan Smith

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

With limited land and water resources available it has become critical to maximize output for agricultural products while maintaining sustainable farming practices. Ricefish co-culture can be used to maximize limited land and water resources for production of rice and fish concurrently and reduce the need of chemical inputs. While rice-fish co-culture has been practiced in Asia for centuries, very few studies have examined the feasibility and economic impact of rice fish co-culture in the U.S.A. Two studies were conducted in Stuttgart, Arkansas, U.S.A. from 2023-2024 to investigate the suitability of raising Koi carp in flooded rice paddies with a sushi …

Willa Cather’S Uneven Ground: Guest Editor's Introduction, Emily J. Rau

University of Nebraska-Lincoln Libraries: Faculty Publications

Guest editor's introduction to the summer 2025 issue of Western American Literature, a special issue on resettling Willa Cather’s West.

Legacy Nutrient Transport By Overland Sheet Flow, John E. Gilley, Ryan P. Mcgehee, Kenneth M. Wacha

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The transport of phosphorus (P) and nitrogen (N) from sites containing varying quantities of legacy nutrients was evaluated in this investigation. The data that were examined were collected during four previously reported field hydrologic studies performed in eastern Nebraska. Additional flow was introduced to the top of the rainfall simulation plots to replicate runoff conditions occurring along a hillslope. It was observed that both P and N delivery were influenced by runoff rate on sites where beef cattle manure or inorganic fertilizer had been applied. Legacy nutrient delivery appeared to have been influenced by the quantity of nutrients released at …

Reaction Control Mechanism In Deoxyuridine 5'-Triphosphate Nucleotidohydrolase, Aaron Delay

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

Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) is an enzyme involved in the pyrimidine biosynthesis pathway, a key component of cellular DNA metabolism. It regulates intracellular uracil carrying triphosphate levels by hydrolyzing dUTP, thereby providing a substrate for thymidylate synthase (TS). The effective inhibition of dUTPase is expected to enhance TS-targeted chemotherapy by promoting thymine-less apoptosis.

Although the reaction mechanism of dUTPase has been studied, the human nuclear homotrimeric form remains complex, as all three subunits cooperatively form a single active site. As a result, the detailed molecular dynamics of its catalysis are still not fully understood. In this study, I investigated the …

Evaluation Of Waste Plastic Addition Via Dry Method On Asphalt Mixture Performance, Isabella Madeira Bueno

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Incorporating waste plastic (WP) into hot mix asphalt (HMA) offers a promising approach to enhance recycling rates and improve asphalt concrete (AC) performance, particularly in moisture damage resistance. However, results vary widely due to differences in WP types, sizes, and mixing methods. The lack of standardized procedures, especially for the dry process, has led to inconsistent integration and unclear roles of WP in AC mixtures. Studies suggest that introducing WP to pre-heated aggregates at temperatures exceeding its melting point can enhance mixture resistance to rutting, cracking, and moisture damage. In this context, this study was conducted in two phases to …

A Discrete-Time Adaptive Sliding Mode Controller For A Multicopter With A Suspended Payload, John Helzer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents a Discrete-time Adaptive Sliding Mode Controller (DASMC) for control of a multicopter with a suspended payload. DASMC is designed to stabilize the multicopter at a desired position while minimizing the load oscillations induced by a significant hanging payload. The proposed DASMC minimizes the need for system-specific parameters like tunable gains and improves robustness to both external disturbances and model uncertainties compared with existing controllers. The controller is designed for direct digital implementation on a variety of multicopter platforms with considerations like discrete-time design, adaptive gain shrinking, and saturation handling. When deployed on a real multicopter in an …

A Quantitative Examination Of The Sexual Health Of Aging Black Men In Rural South Africa, Esihle Lupindo

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

This dissertation uses survey data primarily from Wave 1 of the Health and Aging in Africa: Longitudinal Study of In-depth Community in South Africa (HAALSI) which was collected in 2015 to study the sexual health of Black men in rural Mpumalanga, South Africa. Broadly speaking, I examine aging men’s sexual health as it related to HIV, well-being, loneliness, social networks and disclosure. The definition that I use for sexual health was coined by MacPhail and Campbell (2001) who define it as “not only sexual practices but also what people know and believe about sex, particularly what they think is natural, …

Nebraska Farm Real Estate Market Highlights 2024-2025, Jim Jansen

Nebraska Farm Real Estate Reports

Reversing a half decade in gains, the all-land average value in Nebraska declined for the year ending February 1, 2025, averaging approximately 2% lower than the prior year. Figure 2 summarizes these figures and trends along with the percent changes over the preceding year’s all-land average for the eight districts in the state.

Rates of decline were the highest in the Northeast and Southeast Districts, as these areas averaged 3% lower for the all-land average. These Districts trended slightly similar to the state's rate of decrease of 2%. The South and Southeast District also averaged 2% lower.

The other four …

Gmos And Public Perception: College Students’ Opinions And Knowledge Of Genetic Engineering, Serene M. Cheng

RURALS: Review of Undergraduate Research in Agricultural and Life Sciences

Genetically modified organisms (GMOs) can be developed and implemented to address significant global challenges, including nutrient deficiencies, climate change, and crop disease. However, widespread opposition has prevented the success of GMOs. We believe this opposition is strongly connected to a lack of understanding about genetics in general, which has been reflected by previous studies.

In this study, we considered the relationship between GMO support and genetics knowledge by comparing results from a brief quiz and responses to prompts relating to GMOs. Using a survey of college students, we found that support for GMOs and general knowledge of genetics are positively …

Annotated Checklist And Distribution Of The Jewel Beetles (Coleoptera: Buprestidae) Of Idaho, Luc Leblanc, Emma L. Eakins

Insecta Mundi

An annotated checklist of the 102 species of Buprestidae (Coleoptera) known to be present in the state of Idaho is provided, with photographs and detailed distribution maps for each species. The checklist is based on label data from 7,506 museum specimens, 21 observations obtained from iNaturalist.org and Bug-Guide.net, and 63 distribution records from published literature. Buprestis consularis Gory is a new record for Idaho, formerly reported as Buprestis nutalli Kirby, which is not known to occur in the state. Obscure past records of Anthaxia retifera LeConte and Melanophila occidentalis Obenberger published in the literature are regarded as dubious and are …

Genomics-Based Taxonomic Refinement Of Emesis Fabricius (Lepidoptera: Riodinidae), Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick V. Grishin

Insecta Mundi

Expanded genomic sequencing of Emesis [Fabricius], 1807 (Lepidoptera: Riodinidae Grote, 1895) reveals additional taxonomic insights. As a result of this study, one subgenus and 10 species are proposed as new (type species or type localities in parenthesis): Sinuata Grishin, new subgenus (Emesis sinuatus Hewitson, 1877) of Exoplisia Godman and Salvin, 1886; Emesis (Mandania) mandaca Grishin, new species (Mexico: Oaxaca); Emesis (Mandania) mantunga Grishin, new species (Ecuador: Tungurahua); Emesis (Tenedia) hidalga Grishin, new species (Mexico: Hidalgo); Emesis (Tenedia) vera Grishin, new species (Mexico: Veracruz); Emesis (Tenedia) nica Grishin, new species …

A New Species Of Leaf Litter Inhabiting Species Of Stevenaltica Konstantinov, Linzmeier And Savini From The United States (Coleoptera: Chrysomelidae: Galerucinae: Alticini), Amy L. Brown, Shawn M. Clark, Alexander S. Konstantinov

Insecta Mundi

A new species, Stevenaltica parvarotunda Bown, Clark, and Konstantinov (Coleoptera: Chrysomelidae), is described from Ohio, U.S.A. This is the first report of this genus in North America. Brief comments are made regarding Exoceras Jacoby and Leptophysa Baly.

Three New Species Of Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae) From Mexico And Central America, Ángel Solís, Burt Kohlmann

Insecta Mundi

Three new species assigned to the satanas species-group of Dichotomius Hope (Coleoptera: Scarabaeidae: Scarabaeinae) are described from North and Central America: Dichotomius pisuicas Solís and Kohlmann, new species, from the Caribbean slope of Honduras to Panama; D. lucifer Solís and Kohlmann, new species, from the Costa Rican and Panamanian Pacific rainforests; and D. chamuco Solís and Kohlmann, new species, from Mexico to Honduras. A description, diagnosis, images, and distributional map are presented for each species.