Digital Commons Network^™

Evaluating Metamitron Efficacy For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) Management In Sugarbeet Across The Central High Plains, Abraham Akuoko

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

Herbicide-resistant (HR) Palmer amaranth (Amaranthus palmeri S. Watson) is regarded as one of the most prominent weeds within sugarbeet fields across the Central High Plains, with limited chemical control options. Although a few herbicides are available, their use is restrictive due to crop injury concerns and can only be applied at or after the 2–4 true leaf (TL) growth stage, which will provide no control for already emerged weeds. However, Palmer amaranth often emerges between sugarbeet planting and the 2 TL sugarbeet growth stage. Consequently, as of 2023, there were no herbicide options to control Palmer amaranth in sugarbeet …

Evaluation Of Distractor Model Specifications On Assessment Quality Within The Framework Of Assessment Engineering, Sunhyoung Lee

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

Responding to the high demand for new test items, model-based item development has emerged as a promising approach for efficient item creation. Item models within Assessment Engineering (AE) offer a systematic framework that effectively generates a large volume of new items. In the development of multiple-choice questions, well-constructed distractors are essential for ensuring item quality, although creating them requires significant time and resources. A distractor model is a sub-model within an item model, producing correct answers and distractors aligned with all potential items to be generated. Various types of distractor models have different characteristics and offer efficient methods for generating …

Characterization Of Mitochondrial Dna Repair Components And Repair Choices At Targeted Double-Strand Breaks In Arabidopsis Thaliana, Moira Rodriguez

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

Plant mitochondrial genomes are complex when compared to most other eukaryotic mitochondrial genomes. They are large and variable in size, expand and rearrange frequently, abundant in non-tandem repeats, but maintain a very low synonymous substitution rate in the remaining coding regions. Many of these complexities can be explained by the increased use of double-strand break repair for DNA damage. To advance the understanding of mitochondrial genome dynamics as it relates to double-strand break repair, we performed a forward genetics screen to identify proteins involved in DNA repair in plant mitochondrial genomes. Through this screen, we identified an RNA/DNA helicase, Suv3, …

Reinforcement Learning Based Security Schemes For Distributed Ai Systems, Ashan Chamath Gunawardena

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

Distributed machine learning (DML) is a component of modern intelligent systems, enabling collaborative training across devices such as mobile clients, vehicles, and edge networks. However, the decentralized nature of these systems introduces vulnerabilities, particularly data poisoning attacks that compromise model integrity and degrade performance. Traditional defenses, such as statistical filtering, robust aggregation, and privacy-preserving techniques, often struggle to adapt to overwhelming adversaries or operate under strict privacy and real-time constraints. This dissertation proposes the use of reinforcement learning (RL) and deep reinforcement learning (DRL) based misbehavior detection schemes that dynamically identify poisoning attempts in distributed AI systems, including federated learning, …

Modelling Groundwater Nitrate Transport In Bazile Creek Watershed Using Modflow, Prajwol Thapa

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

Excessive application of inorganic nitrogen fertilizers has led to pervasive nitrate contamination of groundwater in agricultural regions worldwide. This study evaluates the fate and transport of nitrate beneath the Bazile Creek watershed in northeastern Nebraska by coupling groundwater‐flow (GWF) and solute‐transport (GWT) simulations within MODFLOW 6. A conceptual model was developed using hydrogeologic, topographic, recharge, and boundary‐condition data, and the domain was discretized with a quadtree-refined grid to capture surface-subsurface interactions. The steady-state flow model was calibrated against observed hydraulic heads and baseflow measurements using NSE, RMSE, and PBIAS metrics, and subsequently extended to a transient flow simulation spanning 2002-2023. …

Ethical Decision-Making Processes In Authentic Environmental Engineering Contexts Through Systems Thinking And Team Collaboration Lenses: An Embedded Single Case Study, Toluwalase Eniola Brower

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

Ethical and professional responsibility is a critical learning outcome emphasized in ABET accreditation. However, ethics instruction in engineering education often lacks integration of system-level considerations such as economic, environmental, and societal contexts, that are essential for developing engineering solutions that ensure the safety and welfare of diverse stakeholders. This embedded single-case study investigated the integration of authentic ethics instruction within a junior-level environmental engineering course at a Midwestern U.S. university during spring 2025 and explores how civil engineering student teams within the course engage in ethical decision-making process during authentic problem-solving.

The instructional intervention consisted of four problem-based ethics modules, …

Changepoint Detection As Model Selection: A General Framework, Michael A. Grantham

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

This dissertation presents a general framework for changepoint detection based on ℓ₀ model selection. The core method, Iteratively Reweighted Fused Lasso (IRFL), improves upon the generalized lasso by adaptively reweighting penalties to enhance support recovery and minimize criteria such as the Bayesian Information Criterion (BIC). The approach allows for flexible modeling of seasonal patterns, linear and quadratic trends, and autoregressive dependence in the presence of changepoints.

Simulation studies demonstrate that IRFL achieves accurate changepoint detection across a wide range of challenging scenarios, including those involving nuisance factors such as trends, seasonal patterns, and serially correlated errors. The framework is …

Rapid State-Of-Health Estimation Of Batteries Using Machine Learning With Limited Eearly-Discharge Voltage Data, Mohammad Bakhtiari

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

The utilization of lithium-ion batteries has been rapidly expanding across diverse sectors, including electric transportation, stationary energy storage systems, and the built environment. Ensuring a high level of reliability in these applications is essential, as the performance and safety of such systems depend strongly on the accurate assessment of the battery’s State of Health (SOH). Conventional SOH estimation techniques—often based on complex electrochemical models or extensive laboratory testing—tend to require a large number of measurements, advanced instrumentation, and high computational cost. These factors make them impractical for large-scale deployment or real-time monitoring. This study introduces a simplified machine-learning-based approach for …

The Graphic Shift: Leveraging Superhero Graphica To Un-Ban Critical Conversations In The Secondary English Language Arts Classroom, Avery Clason

Department of English: Dissertations, Theses, and Student Research

This thesis investigates the challenges that books are receiving during an era of social and political turmoil based on their content. Understanding why these books are polarizing for most readers and the general public is in direct connection with finding different books that can harbor the same conversations about dense topics and cultivating connections between students, the text, the world, and themselves. While there has been a search to find alternate books that are not considered "political flashpoints,” there has been limited research into the use of superhero graphica in the ELA classroom, especially in connection to utilizing this genre …

Integrating Innovative Sensing And Ground Measurements For Forage Mass Estimation In Rye Pasture, Pedro Henrique Jota Fernandes

Department of Animal Science: Dissertations, Theses, and Student Research

The United States beef industry relies on forages to provide up to 80% of total lifetime dry matter intake, making accurate forage mass estimation essential for determining stocking rates, improving grazing efficiency, and supporting economic sustainability. Traditional methods to quantify forage mass, however, are time-consuming and labor-intensive. This thesis presents research efforts to achieve accurate forage mass estimation in cereal rye pasture by integrating novel sensing technologies.

Chapter 1 reviews the importance and evolution of forage mass estimation methods, from destructive clipping to indirect approaches based on canopy measurements. It then introduces remote sensing, from proximal tools to drone- and …

Investigation Of Changes In Exotic Bird Serum Vitamin D Levels Between Indoor And Outdoor Housing, Alexander J. Marley

Department of Animal Science: Dissertations, Theses, and Student Research

Vitamin D is a fat-soluble vitamin that is directly related to sunlight and is involved in multiple physiological processes including calcium metabolism, feather quality, and chick development. Most vertebrate species are capable of both absorption of exogenous vitamin D and internal synthesis of vitamin D, with vitamin D3 (cholecalciferol), being more accessible and bioactive in bird species. In exotic bird species, dietary requirements for vitamin D3 are largely unknown, and the ability to maintain adequate serum concentrations of vitamin D3 metabolites without direct sunlight exposure also requires evaluation. Concerns arise in situations where individuals may be housed indoors for extended …

Occurrence Of Per And Polyfluoroalkyl Substances In Rural Wastewater Treatment Plants And Comparison To Large Treatments Plants, Madeleine Rauhauser

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

Per and polyfluoroalkyl substances (PFAS) are a class of compounds defined by their carbon – fluorine bonds, which are incredibly strong. The strength of this bond makes these compounds very useful industrially, they are used as waterproof and grease proof coatings, and as fire retardants. The same thing that makes them useful industrially makes them incredibly recalcitrant in the environment, it is difficult to destroy these compounds. PFAS are also suspected to cause health impacts in people, such as kidney cancer and low birth weights. Wastewater has been commonly identified as a contributor to the amount of PFAS in the …

Further Evaluation Of Speed Tables On Roadway Curves: Simulation And Expeditionary Deployments, Nathan Reineke

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

The road network leading up to a United States military base is known as an Entry Control Facility, or ECF. Entry control facilities are used to shield military installations by monitoring vehicles and refusing access to unauthorized vehicles. Passive control devices, including speed tables, are used to disrupt or delay threat vehicles attempting to navigate ECFs at high speeds. The purpose of this research was to recommend optimized configurations of speed tables in combination with roadway curves which allow safe, efficient traversal for authorized vehicles and disruption or delay for threat vehicles.

First, an analytical model of a Tesla Model …

Securing Connected And Autonomous Vehicles, Owana Marzia Moushi

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

A vehicular network is susceptible to various security flaws and attacks. Cryptographic techniques are used in vehicular networks but these alone cannot provide proper security to the network. Identifying various types of attacks is necessary to secure vehicular communication networks. In this dissertation, we focused on detecting various insider attacks in vehicular networks to enhance the security of the network.

Our first contribution in this dissertation is the detection of both binary and multi-class data replay and data replay Sybil attacks in vehicular networks. A publicly available dataset, VeReMi-Extension is used to detect these attacks. This dataset has been reformulated …

Molecular Pathway Dysregulation In Chronic Liver Disease: Metabolic And Mechanotransductive Drivers Of Hepatic Pathophysiology, Samantha Harvat

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Metabolic dysfunction–associated steatotic liver disease (MASLD) represents a rapidly growing cause of chronic liver injury, yet the molecular interactions linking metabolic stress, inflammation, fibrosis, and hepatocellular carcinoma (HCC) remain incompletely defined. This thesis integrates transcriptomic analyses across multiple GEO datasets to identify coordinated metabolic, inflammatory, and mechanotransductive pathways that collectively drive disease progression.

Analysis of human liver biopsy datasets (GSE126848 and GSE89632) revealed consistent suppression of glycolysis, β-oxidation, and oxidative phosphorylation across MASLD and MASH samples, accompanied by modest compensatory TCA cycle activation. These alterations reflect impaired metabolic flexibility, mitochondrial stress, and increased ROS susceptibility. Concurrently, cytokine-network enrichment demonstrated activation …

Developing A Metabolic Engineering Chassis From A Metabolically Versatile Organism, Rhodopseudomonas Palustris Cga009, Mark William Kathol

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

Metabolic engineering has made it possible to develop biological processes that were once considered economically unfeasible or uncompetitive. This field has enabled both a robust niche market, whereby products, such as pharmaceutical substances like monoclonal antibodies, are produced exclusively through biological means, as well as an emerging commodity production market. Nonetheless, significant challenges remain in harnessing the unique metabolic capabilities of genetically non-tractable organisms. This dissertation focuses on Rhodopseudomonas palustris CGA009 as a potential chassis for metabolic engineering. To address the issue of genetic intractability, a synthetic biology toolkit was developed to facilitate the expression of heterologous proteins in R …

Detecting Prescribed Fire, Haying And Grazing Events Via Remote Sensing To Create Grassland Disturbance Landcovers For The Ring-Necked Pheasant (Phasianus Colchicus), Megan Amy Baldissara

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

This dissertation developed disturbance detection models to fulfill the need for remote sensing landcover products describing grassland structure. The use of landcover products derived from remote sensing is increasing over time in pheasant (Phasianus colchicus) research. Such landcover, however, does not provide relevant pheasant structural habitat information (Chapter 1). Pheasants require tall, high-density grassland for nesting, tall grassland with medium density for brood rearing, and tall grassland for wintering. Time since disturbance can serve as a proxy for structure, as it shapes vegetation by removing biomass and resetting succession. Disturbance is easier to detect than structure with current …

Exploring Transformative Learning Experiences In Engineering Doctoral And Post-Doctoral Education: Developing Non-Technical Competencies For Early-Career Academic Roles, Ibukunoluwa Eunice Salami

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

This dissertation explores the transformative learning experiences that early-career engineering faculty recounted from their doctoral and postdoctoral training and how these experiences shaped the development of non-technical competencies essential for academic success. Grounded in Mezirow’s Transformative Learning Theory (TLT) and the Competency-Based Professional Development Framework (CBPDF), the study examines how reflection and shifts in frames of reference supported competency growth and faculty readiness. A qualitative holistic single-case study design was employed. Data sources included semi-structured interviews with early-career engineering faculty and program learning objectives drawn from graduate handbooks. Data analysis was both deductive and inductive guided by Mezirow’s ten phases …

In-Field Tractor Operational Load Profile Generation In Support Of Advanced Tractor Testing In Mixedmode Power, Andrew Donesky

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

This dissertation addresses the need to better characterize real-world tractor power requirements across drawbar, power take-off (PTO), and hydraulic modes to support more representative tractor testing. Conventional testing protocols, such as OECD Code 2, emphasize steady-state performance under controlled high-load conditions, which do not reflect the mixed and dynamic demands of modern field operations. To address this gap, a Tractor Instrumentation System (TIS) was developed, validated, and deployed to collect high-resolution, mixed-mode power data during planting, anhydrous ammonia application, and grain cart operations. The TIS integrates physical sensors, including custom load pins, hydraulic pressure/flow sensors, and a redesigned PTO torque …

Investigating Programming Behaviors To Understand Student Engagement And Experience In Introductory Programming Courses, Marcus Eugene Gubanyi

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

Introductory programming courses are foundational to developing students’ problem-solving abilities and shaping their persistence in computing pathways. Engagement with programming tasks plays a central role in student learning and experience. Many research measures, including self-reports and code submissions, offer only a limited view of student engagement with programming tasks. This dissertation leverages programming process data, consisting of keystrokes and compilation events, to capture the programming process as it unfolds and to investigate observable programming behaviors. Guided by educational theories, three studies examine how students’ programming behaviors vary across instructional and assessment contexts, how they relate to motivational profiles, and how …

Large-Scale Experimental Study On The Impact Of Air Cleaning & Ventilation On Indoor Air Quality And Student Illness-Related Absenteeism, Daud Nosham

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

This large-scale randomized experimental field study investigated the effect of portable air purifiers (PAPs) on classroom’s air quality and student’s illness related absenteeism. PAPs were installed in 317 classrooms from various school districts located in Eastern Nebraska. The classrooms were randomly assigned into four conditions: three treatment conditions (T1, T2 & T3) and one control condition (device without any filter). T1 was equipped with HEPA filters, T2 added Activated Carbon (AC) layer to HEPA, and T3 further integrated Germicidal Ultraviolet (GUV) alongside HEPA and AC filters. The measured variables were carbon dioxide (CO2), fine particles (PN2.5) and coarse particles (PNcoarse), …

Real-Time, Co-Regulated Design For Cyber-Physical, Multi-Rotor Uas Swarms, Grant Simon Phillips

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

Uncrewed Aerial Systems (UAS) have been integrated into a wide range of research and industrial applications, with growing interest in extending mission duration and spatial coverage through coordinated multi-UAS systems, or swarms. While swarming offers the potential for extended mission endurance and robustness through advanced path-planning, control, and estimation algorithms, significant challenges arise when implementing these methods on decentralized platforms composed of size, weight, and power-constrained (SWaP) vehicles. Limitations in onboard computational capacity and congested communication channels can break critical design-time assumptions, which at best, will degrade application quality of service, and at worst, destabilize the fleet through excessive delays …

Ai-Enabled Robotic Nitrogen Management, Ankita Kalra

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

Nitrogen management in corn agriculture faces economic and environmental challenges, motivating development of precision, site-specific solutions. This dissertation presents AIR-N (AI-Enabled Robotic Nitrogen Management), a novel system that integrates cloud-based artificial intelligence with an autonomous field robot (Flex-Ro) to optimize nitrogen fertilizer application in real time. The research is driven by the need to improve nitrogen use efficiency while reducing leaching and emissions.

Comprehensive architecture (Cloud-E) was designed using Amazon Web Services to ingest multi-modal agronomic data (soil sensors, crop reflectance, weather) and host machine learning models. A Random Forest-based model was trained on historical field data to predict spatially …

An Integrated Modeling Framework To Evaluate Circularity Of The Corn–Water–Ethanol–Beef Nexus, Heydi Han

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

This dissertation examines the transition from conventional linear agricultural and food bioenergy systems toward more circular, resilient, and resource-efficient configurations. Prior research indicates that spatial and temporal variability in soil, weather, animal biological responses, and management decisions strongly influences productivity, nutrient-use efficiency, and profitability. Studies have also shown that a diversified circular system can buffer these sources of variability, improving stability and adaptive capacity. Building on these insights, the central focus of this work is to develop an integrated modeling framework to evaluate circularity within the Corn-Water-Ethanol-Beef (CWEB) nexus and explore how climate variability and management choices shape system-wide performance. …

Making Deep Neural Networks Trustworthy: Intelligibility And Safety Through Symbolic Methods, Eleanor Catherine Quint

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

The rapid adoption of deep learning has come at the cost of properties long valued in artificial intelligence: intelligibility and safety. This dissertation develops methods that restore these properties by coupling neural networks with symbolic structure.

First, for supervised classification, I propose a differentiable decision tree integrated with a supervised variational autoencoder. The resulting model maintains competitive accuracy and generative performance while exposing clear macro-features in its latent space, improving interpretability.

Second, for reinforcement learning, I extend constrained Markov decision processes by specifying constraints in formal languages. This formal language constrained MDP enables the use of automata for state augmentation, …

Interview With Orca Award Winner James Van Etten, Unl Plant Pathology; Discoverer Of Giant Viruses, Mark Griep, James Van Etten

UNL ORCA Interview Series

Dr. James Van Etten was awarded the UNL Outstanding Research and Creative Activities Award in 1992. He was born in Virginia but grew up Peoria, Illinois. Something in his youth must have sparked an interest in science because he earned his bachelor’s degree in biology from Carleton College in 1960. Carleton is a well-regarded liberal arts institution in Northfield, Minn., about 400 miles from Peoria. Next, Jim earned a master’s and doctorate at the University of Illinois in Champaign-Urbana, both in plant pathology. For his postdoctoral work in 1965 and 1966, he did postdoctoral work in the Department of Genetics …

Program Transition Success: A Practical Guide For Educators Moving Sbae Programs, Evey Choat

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

What tools, strategies, and support systems can help agriculture educators navigate leadership transitions and sustain program success when moving between schools or communities? Teacher mobility and leadership transitions within School-Based Agricultural Education (SBAE) present unique challenges to program continuity, community relations, and professional sustainability. Unlike other subject areas, SBAE teachers often manage multifaceted responsibilities—as classroom instructors, FFA advisors, and community liaisons—making transitions between programs especially complex. This project addresses the lack of structured support for educators navigating these transitions by developing a Program Transition Guide specifically tailored to the needs of agricultural educators in Nebraska.

Guided by Transformational Leadership Theory …

Nebline, November/December 2025

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Contents

Nebraska Extension celebrates 25 years of nutrition school enrichment kits

Recipe of the month: Fruit & yogurt parfait

Celebrating the season with American persimmon by Rachel Anderson

Love gardening? Become a master gardener by Mary Jane Frogge

Extension master gardener volunteer spotlight: Carol Rustad

Garden guide: Things to do this month by Mary Jane Frogge

Choosing child care: What parents should know by Jaci Foged

Commercial/noncommercial pesticide license

Little black bugs, big bite by Kait Chapman [about pirate bugs]

What you need to know about having a well drilled by Becky Schuerman

2026 nebraska custom rates survey by Glennis …

Flea News 96 (November 2025), R. L. Bossard

Flea News

Flea News is a twice-yearly newsletter about fleas (Siphonaptera). Before including in publications any of the citations given here, please review for accuracy and correct formatting. Many of our sources are abstracting journals and current literature sources, and editors have not necessarily checked citations.

Announcements

Obituary: Lane Douglas Foil (June 16, 1949 - June 22, 2025)

Siphonaptera Literature (2025): Taxonomy, Conservation, Hosts and Distributions, Physiology and Morphology, Evolution, Ecology, Pathology and Control, Microbial Symbionts

Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #68 November 2025

Gamma Sigma Delta, Nebraska Chapter: Newsletters

President's message, Deb VanOverbeke
Membership Information
2025 Outstanding Graduate Student Award Nomination Solicitation
2025 Teaching Award nomination solicitation
2025 Research Award nomination solicitation
2025 Extension Award nomination solicitation
2025 Award of Merit nomination solicitation
Gamma Sigma Delta Committees 2025
Annual Dues Notice
Membership Info and Dues
Student Award Fund solicitation
In Memoriam: Wayne W. Oberg (September 8, 1948 - February 21, 2025); Robert M. "Bob" Scriven (June 26, 1936 - August 29, 2025)
Pledge and Honor Cords
Save the Date: Initiation and Awards Reception