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Synthesis And Characterization Of Polymer-Coated Metal Nanostructures And Gelatin-Incorporated Hydrogels For Biomedical Use, Deborah Takyibea Okyere

Graduate Theses and Dissertations

The development of advanced materials for disease management and treatment presents a pressing challenge in the health sector. The overall objective of this research is to contribute to the development of advanced materials with tailored properties for biomedical applications, with a focus on cost-effective and robust nanoparticles and biomaterials. The first part of this work focuses on designing and synthesizing earth-abundant copper nanoparticles with desired optical properties. Copper nanoparticles, which provide a more affordable alternative to gold and silver, are being investigated due to their unique plasmonic properties. However, their susceptibility to oxidation limits their application. To address this challenge, …

The Upcoming Moral Crisis In Primitive Artificial Intelligence, Justin E. Edens

Graduate Theses and Dissertations

As we continue to develop artificially intelligent systems, there is an increasingly high chance that we will develop a system that is both conscious and capable of suffering. Furthermore, it is likely that the development of this conscious machine will be entirely unintentional. While this machine will have moral status, identifying it will be extremely difficult, leading to it being treated the same as its inert predecessors. For these reasons I believe that a crisis in ethics is looming. This paper aims to argue that it is possible for a machine to have moral status, that the first such machine …

Utilizing The Horseshoe Prior In Exploratory Factor Analysis And Gaussian Graphical Networks, James Thomas Roddy

Graduate Theses and Dissertations

High-dimensional data analysis frequently involves extracting meaningful structure from noisy, sparse signals. In recent years, Bayesian shrinkage priors—particularly global-local shrinkage priors—have emerged as powerful tools for inducing sparsity while preserving signal fidelity. Among these, the Horseshoe prior has gained notable attention for its capacity to simultaneously shrink irrelevant parameters and retain substantial signals. This dissertation explores the Horseshoe prior as a unified framework for sparse Bayesian inference across theory, simulation, and real-world application. The first component develops new theoretical results establishing the asymptotic Bayes optimality of the Horseshoe prior in Gaussian graphical models (GGMs). We consider sparse precision matrix estimation …

Resilience Redefined: Exploring The Impact Of Childhood Trauma On The Value Systems Of High-Achieving Corporate Men, Lana B. Henry

Graduate Theses and Dissertations

This qualitative study employed Interpretive Phenomenological Analysis (IPA) to explore how childhood trauma influences the value systems of high-achieving corporate men. In contemporary corporate culture, where stoicism, performance, and independence are often rewarded, little attention is paid to how early adversity informs internal frameworks of meaning, leadership, and success. Semi-structured interviews were conducted with six high-achieving men, all executives and leaders in high-performing industries, who self-identified as having experienced childhood trauma. Data were analyzed using a six-step IPA process and interpreted through the lens of Schwartz’s Theory of Basic Human Values and social constructivism. Findings revealed that childhood trauma deeply …

End Times: American Mortality, Death Materiality, And Social Death In The 1990s, Jordan A. Savage

Graduate Theses and Dissertations

The United States in the 1990s was marked by pervasive representations of death in popular culture. As death imagery became increasingly visible in entertainment, there was a growing detachment from the embodied, biological realities of death, a tension intensified by the ongoing AIDS crisis. This project explores how death is politicized and how decisions about who lives and dies are shaped by power. I draw on a constellation of theoretical frameworks that collectively illuminate the operations of state-sanctioned death and social abandonment. These include Michel Foucault’s concept of biopolitics, which examines the management of life by state power; Giorgio Agamben’s …

A Grounded Theory Investigation Of The Experiences Of Rehabilitation Administrators, Counselors, And Supervisors Providing Services To Women With Disabilities Experiencing Intimate Partner Violence, Dana Posey

Graduate Theses and Dissertations

Abstract There is a noticeable gap in the literature as it relates to how rehabilitation and disability service providers have worked with women with disabilities who have experienced intimate partner violence. To address the dearth of knowledge, a qualitative grounded theory study was conducted with 12 rehabilitation administrators, counselors, and supervisors regarding their experiences providing services to women with disabilities who have been in or are in an intimate partner violence relationship. Semi-structured interviews were administered, recorded, and transcribed verbatim in an ongoing manner throughout the process. As data was collected, it was analyzed using NVIVO 15, which is a …

Impact Of Three Professional Development Models (Online, Face-To-Face, And Hybrid) On Bhutanese Inservice Science Teachers' Conceptions Of Aspects Of Nature Of Science (Nos) With Reports Of Translation Of Nos Content Into Classroom Teaching Practices, Pabi Maya Das

Graduate Theses and Dissertations

Having a scientifically literate citizenry is an asset nationally and globally, and knowledge of the nature of science (NOS) is a crucial element in such literacy. Science teachers are a vital link if students are to understand key elements of the NOS, yet teachers themselves often lack knowledge of NOS and how to integrate NOS content into science lessons. Investigating the impact of a series of inservice professional development experiences using three distinct delivery modes (face-to-face, hybrid, online) for teachers in my home country of Bhutan is the overarching goal of the study reported here. The study used a mixed-methods …

Small Angle X-Ray Scattering Studies Of Collagenase H Mutant, Colh-E416q, Madelyn Millsap

Graduate Theses and Dissertations

Collagenase H (ColH) from Hathewaya histolytica plays a central role in collagen degradation through endopeptidase and carboxytripeptidase reactions. To better understand how its domain architecture supports these functions, we examined the solution structure of a catalytically inactive mutant, ColH-E416Q, using small-angle X-ray scattering (SAXS). The E416Q mutant is catalytically inactive because the glutamate residue at position 416, which normally functions as a general acid/base during catalysis, is replaced by glutamine—an amide that cannot donate or accept protons effectively, thus disabling the proton transfer steps essential for peptide bond hydrolysis. SAXS results indicate that the E416Q substitution leaves overall domain architecture …

Advancing Point-Of-Care Diagnosis Of Joint Infection Using A Diffuse Reflectance Spectroscopy (Drs) System, Erin Elizabeth Drewke

Graduate Theses and Dissertations

Septic arthritis is a severe joint infection that can rapidly destroy cartilage and cause lifelong disability if not diagnosed and treated promptly. Faster, bedside diagnostic tools are needed to reduce delays and support timely treatment decisions while preserving standard laboratory workflows. A syringe-mounted diffuse reflectance spectroscopy (DRS) system was developed for rapid, sterile, point-of-care measurement of synovial fluid optical properties. Broadband light (400–650 nm) was delivered and collected through the syringe barrel without contaminating the sample. An empirical lookup table (LUT) and a boundary-aware Monte Carlo (MC) model were implemented to extract absorption (μₐ) and reduced scattering (μs′) coefficients from …

Lifetime Stressor Exposure, Race And Ethnicity, And Habitual Stress Processes: An Evaluation Of Repetitive Negative Thinking And Hair Cortisol Concentration, Harrison Dickens

Graduate Theses and Dissertations

Habitual stress processes are thought to influence acute stress reactivity and stress-related disease. Habitual stress processes have been shown to adapt in response to stressor exposure experienced across the lifespan. The current study seeks to explore whether two habitual stress processes, hypothalamic-pituitary-adrenal (HPA) axis activity and repetitive negative thinking (RNT), were associated with lifetime stressor exposure (self-reported and objective neighborhood-level stressors). Additionally, the current study attempts to quantify how this process may be moderated by race and ethnicity. Participants (N = 134, Mage = 18 [SDage= 1.69], 56.7% female) consisting of White (N = 52), Black (N = 37 ), …

Improved Autofluorescence Lifetime Decay Analysis For Identification Of Cellular Autofluorescence Biomarkers For Label-Free, Single-Cell Assessment Of Mitochondrial Membrane Potential, Olivia Isabel Kolenc

Graduate Theses and Dissertations

Optical imaging of metabolism using the autofluorescence of the metabolic cofactors NADH, NADPH, and FAD has a wide range of sensitivities and the capability to collect a great deal of metabolic information. Multiphoton microscopy (MPM) is a non-invasive, label-free optical imaging technique capable of performing fluorescence lifetime imaging (FLIM) using time correlated single photon counting (TCSPC). However, autofluorescence FLIM presents a challenge in collecting sufficient photons to provide adequate signal to noise ratios (SNR) for analysis. Additionally, the specificity of autofluorescence biomarkers of metabolism has not been well-defined. Contextualizing these autofluorescence measures using established functional biomarkers can improve interpretability of …

Host-Virus Interaction Dynamics Using Sulfolobus Spindle-Shaped Virus And Host Sulfolobales System, Yeasin Ahmed

Graduate Theses and Dissertations

The Sulfolobus Spindle-shaped virus (SSV) is among the most studied archaeal viruses, particularly in extreme environments. This virus predominantly infects multiple Crenarchaea from the Sulfolobaceae family. These hosts thrive in extreme environmental conditions, such as sulfuric hot springs, with a pH of 2 to 4 and a temperature of 76-80˚C. Sulfolobales exhibit a wide geographical distribution across volcanic hot springs. The Sulfolobus Spindle-shaped Virus (SSV), encompassing strains such as SSV1 and SSV8, employs a non-lytic replication strategy in hosts belonging to the order Sulfolobales. The SSV-Sulfolobales system can be cultured in liquid and gellan gum solid media. A comprehensive study …

Synthesis, Structural Characterization And Optical Studies Of Silver-Indium-(Zinc)-Chalcogenide Fluorescent Quantum Dots, Sujal Acharya

Graduate Theses and Dissertations

Developing a non-toxic, high-performance fluorescent nanomaterial is crucial for overcoming the environmental and health restrictions of current cadmium, and lead based quantum dots (QDs), which limit the application of quantum dots in optoelectronics and bioimaging. In this thesis, we synthesized environmentally friendly AgInS2 QDs by a colloidal method, systematically altering the In/Ag precursor ratio from 2 to 6 to study the impact on their optical and photophysical properties. Our goals were to find the optimal stoichiometry for maximum quantum efficiency and stability. We also investigated further improving optical and photophysical properties through shelling with ZnS. The emission spectra appeared broad, …

Multimodal Deep Learning For Enhanced Breast Cancer Diagnosis On Sonography, Ting-Ruen Wei, Aileen Chang, Young Kang, Mahesh Patel, Yi Fang, Yuling Yan

Bioengineering

This study introduces a novel multimodal deep learning model tailored for the differentiation of benign and malignant breast masses using dual-view breast ultrasound images (radial and anti-radial views) in conjunction with corresponding radiology reports. The proposed multimodal model architecture includes specialized image and text encoders for independent feature extraction, along with a transformation layer to align the multimodal features for the subsequent classification task. The model achieved an area of the curve of 85% and outperformed unimodal models with 6% and 8% in Youden index. Additionally, our multimodal model surpassed zero-shot predictions generated by prominent foundation models such …

The Role Of Cleavage And Polyadenylation Spcific Factor 6 (Cpsf6) In Hematopoiesis, Fengxi Ye

Dissertations and Theses (Open Access)

Cleavage and polyadenylation specific factor 6 (Cpsf6) translocation is frequently reported in APLL, which is Acute Promyelocytic Leukemia (APL)-like acute myeloid leukemia (AML) and other types of blood diseases associated with abnormal hematopoiesis. CPSF6 is a subunit of the Cleavage Factor I mammalian (CFIm) complex, which regulates post-transcriptional alternative polyadenylation (APA) of pre-mRNAs. Previous research indicated that Cpsf6 plays an essential role in alternative polyadenylation, development, and tumorigenesis. However, the role of Cpsf6 in hematopoiesis is unknown. Given its roles in APA, development and cancer, we hypothesize that Cpsf6 plays a critical role in hematopoiesis and that its …

Coastal Transition Zone Development Effects On Salt Marsh Ecology, Amanda Mei Pysher

Electronic Theses and Dissertations

The coastal transition zone (CTZ) is a regional gradient linking terrestrial and marine systems, comprising of the terrestrial upland, the marsh-upland ecotone, and estuarine salt marshes. Along all US coastlines, including the South Carolina (SC) coast from Little River to Georgetown, increases in anthropogenic development of terrestrial uplands have altered the historically established vegetation, and various physical, chemical, biological, and geological gradients. Despite the CTZ's ecological importance, the trickle-down effects of terrestrial upland development on associated high marsh habitats remain understudied. Data were collected from developed (DEV) and undeveloped (UND) shorelines across three SC estuarine inlets. Multilevel modeling (MLM) was …

Migratory Patterns Of Juvenile Shortfin Makos (Isurus Oxyrinchus): Evidence Of A Nursery In The Western North Atlantic, Julia A. Crews

Electronic Theses and Dissertations

Shortfin Makos, Isurus oxyrinchus Rafinesque, 1810, are lamnids that have a global distribution in temperate and tropical oceans. Locations of critical early life history events including birthing and nursery areas are unknown or unconfirmed for most populations. The objective of this study was to identify if a nursery area for Shortfin Makos in the northern waters of the Mid-Atlantic Bight using the criteria articulated by Heupel et al. (2007). Satellite tags were used to track the movement of juveniles (<200 cm TL, n=7) up to 5 months. Tag detections (n=882) confirmed that young makos stay in continental shelf waters of the northern Mid-Atlantic Bight off Long Island through the meteorological summer (June–August) and early meteorological fall (September–October) when sea surface temperatures are 18–23°C. There was clear migratory movement from juveniles once sea surface temperatures fell below 15°C. During late fall, some young sharks moved south towards Cape Hatteras, North Carolina, while one shark moved east up to 1,800 km into the open north Atlantic Ocean into meteorological winter. These movement data of juvenile Shortfin Makos combined with multi-year catches and sightings (2018–2024) provide strong evidence for a nursery area in the northern Mid-Atlantic Bight. By identifying a nursery area for Shortfin Makos, knowledge gaps that currently exist for this vulnerable species and support effective management can be closed.

Comparison Of Nutrient Concentrations And Primary Production Indicators Across Plume Fronts, Taylor Dishon

Electronic Theses and Dissertations

Coastal buoyant plumes carry low-salinity waters containing particulate and dissolved terrestrial materials with an abundance of nutrients into the coastal ocean, including inorganic nitrogen and phosphorous. Plume fronts act as transport barriers created from the convergence of a fresher plume with an older, saltier plume or with ambient waters, leading to potential accumulation of phytoplankton and nutrients. This accumulation creates an optimal environment for primary production. The primary goals of this study were: to investigate the distribution of and potential relationships between nutrient concentrations and chlorophyll a across plume fronts of the Winyah Bay River Plume, and examine potential relationships …

Site Fidelity, Seasonality, Movement, And Fish Associates Of Sand Tigers Carcharias Taurus In North Carolina, Ara L. Mcclanahan

Electronic Theses and Dissertations

Sand tigers Carcharias taurus are mackerel sharks with a disjunct global distribution in tropical and temperate seas. In the northwest Atlantic, sand tigers migrate along the coast of the eastern United States from the Gulf of Maine to Florida and occupy structurally complex benthic habitats. The long-term, underwater camera installation, SharkCam, at Frying Pan Tower, off Cape Fear, North Carolina, USA, sits atop an expanse of hard bottom reef frequented by sand tigers. The citizen-science platform Spot A Shark USA (SAS USA) uses images of sand tigers to identify and track individuals. This study utilized image encounters from SAS USA …

Adolescent E-Cigarette Expectancies: Measure Development And Preliminary Validity Of The Electronic Nicotine Vaping Outcomes Measure For Youth, Paul T. Harrell, Kelli J. England, Tracey E. Barnett, Vani N. Simmons, Richard W. Handel, Amy C. Paulson

Department of Pediatrics Faculty Publications

BACKGROUND: Electronic nicotine delivery systems (“e-cigarettes”) are the nicotine product most commonly used by adolescents. Research, treatment, and policy could benefit from measures of adolescent e-cigarette beliefs about outcomes of use (ie, expectancies). In the current study, we developed and tested an adolescent electronic nicotine vaping expectancy measure.

METHODS: A focus group with adolescents evaluated potential e-cigarette expectancy items. A panel of national experts assisted in revision of these items. Finally, items were administered to a sample of adolescents 14-17 years old (N = 267, Mean age 15.6, SD = 1.1, 50.9% Female, 50.2% Non-Hispanic White, 22.5% Non-Hispanic Black, 14.2% …

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 …

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 …

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 …

Educating The New Generation Of Food Scientists Through Innovative Learning Experiences, Karen Andrea Nieto Flores

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

Food science provides an opportunity to engage high school students in Science, Technology, Engineering, and Mathematics (STEM) by connecting classroom concepts to real-world applications. Despite the field’s relevance to public health, food safety, sustainability, and innovation, food science remains largely absent from high school curricula, and few students recognize it as a viable STEM pathway. This research addressed this gap by evaluating immersive summer camp experiences and teacher-focused curriculum review as strategies to increase food science awareness and interest among students and educators. A literature review traced the historical development and current landscape of K–12 food science education, identifying barriers …

Egg White Hydrolysate In Hypertension: A Mechanistic Investigation Of Gut Microbiota Dependent And Independent Pathways, Emerson David Nolasco

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

Cardiovascular diseases are one of the leading causes of mortality worldwide in which hypertension is a risk factor. Present pharmacological interventions require long-term adherence to the therapy and are often associated with undesirable side effects. Moreover, treatments have overlooked the role of the microbiome in the development of hypertension. Egg white hydrolysate (EWH) has exhibited antihypertensive properties with potential to be used as a natural alternative for the prevention and management of hypertension. However, EWH peptide’s effect on the gut microbiome remains yet to be elucidated. Studies have described that a portion of the ingested protein can remain undigested as …

Functional Genomics Of Phosphatidylcholine Biosynthesis In Saccharomyces Cerevisiae, Amanda Marie Maliva

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

Phosphatidylcholine (PtdCho) is a prominent structural building block of cell and organelle membranes in animal, plant, and fungal cells and some bacteria. Due to its abundant nature in the plasma membrane and intracellular organelle membranes in eukaryotes, the biosynthesis of PtdCho must remain regulated to preserve the correct membrane lipid composition. Dysregulations in PtdCho metabolism can lead to mitochondrial dysfunction, cell death, and the development of diseases including cancer, atherosclerosis, and hepatic diseases. Knowledge of PtdCho has remained limited to the genes involved in its three biosynthetic pathways (Kennedy (K), methylation (M), and acyltransferase (A)), despite the growing realization of …

Characterization Of Undergraduate Biology Instructors’ Goals And Strategies For Implementing Quantitative Reasoning, Anum Khushal

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

Quantitative reasoning (QR) is the application of mathematics and statistics to real-life and scientific contexts. It is essential for understanding complex biological phenomena and analyzing large datasets in both academic and professional settings. In response to the growing demand for QR skills, biology educators and researchers have engaged in curricular reforms and education research. This qualitative study explores how undergraduate biology instructors integrate QR into their teaching using a framework informed by pedagogical content knowledge (PCK) and QR. The study involved 21 biology faculty from various U.S. institutions who intentionally incorporated QR in their instruction. Data was collected through semi-structured …

Multiscale Drivers Of Water Level Fluctuations And Nutrient Availability In Small Intermittent Reservoirs In The Us Midwest, Uchechukwu Vitus Chinatu Ogbenna

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

Reservoir dynamics are often captured by fluctuations in water surface elevation, which reflect a complex interplay of hydrologic inputs, climatic conditions, land use influences, and management operations. While water level fluctuations (WLFs) in large regulated systems have been widely studied, the drivers and implications of WLFs in small reservoirs, particularly those fed by intermittent streams, remain poorly understood. Here, we examined the temporal dynamics of WLFs and their relationship with nutrient availability in nine small reservoirs in the U.S. Midwest using daily records from 1985 to 2022. We used water level classification from modified Zscore and transition matrices to assess …