Digital Commons Network^™

To Mine Or Not To Mine?: Discovery Of Polymetallic Nodules And Discussions On Deep-Sea Mining, Haze Doleys

The Synapse: Intercollegiate science magazine

No abstract provided.

Density Functional Theory And Machine Learning Analysis Of C—C Reductive Coupling From Terminal Cyanido And Cyaphido Complexes, Roberto Magdiel Escobar

Theses and Dissertations

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals and industrial chemistry. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations using the Gaussian16 package to elucidate and compare …

Assessing Reproducibility Challenges In Clinical Metabolics, Darcy Lin Cochran

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

Current metabolomics research is expanding to be multiplatform and interdisciplinary. Metabolomic analysis has the potential to provide detailed insight into any biological system of interest to analyze the underlying molecular mechanisms of variables like environment, disease, and genetics. Human clinical metabolomics is a major research area that is often focused on finding biomarkers or panels of biomarkers for different diseases. However, results are difficult to compare across different laboratories since the field of metabolomics has yet to widely adopt best practices for sample preparation, data acquisition and data processing, results are difficult to compare across different laboratories.

This thesis focuses …

Domain-Specific Machine Learning Approaches For Geospatial Problems, Shine Bedi

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

This dissertation explores novel algorithms for complex geospatial problems at the intersection of environmental, social, and computational sciences. Emphasizing the unique challenges of the geospatial domain, particularly the deviation from the independent and identical distribution (IID) assumption, the research spans various methodologies across different domains, demonstrating the benefits of specialized approaches in spatial analysis.

First, we show that machine learning techniques can be effectively used in environmental modeling, which often has severe class imbalance challenges. Using artificial neural networks (ANN), support vector machines (SVM), and extreme gradient boosting (XGB) and techniques to address class imbalance provides insights into groundwater quality …

(R2104) On The Qualitative Results Of Riemann-Liouville Fractional Order Nonlinear Neutral Singular Systems With Mixed Delays, Abdullah Yiğit, Cemil Tunç

Applications and Applied Mathematics: An International Journal (AAM)

In this manuscript, we discuss new conditions for asymptotic stability of nonlinear Riemann- Liouville fractional mixed-delay neutral singular systems. By constructing a set of improved Lyapunov-Krasovski˘ı functionals (LKFs), we establish some new delay-dependent conditions in terms of matrix inequality, which guarantees that the systems are asymptotically stable. In the particular case, we give four numerical examples with their solutions and graphs via MATLAB software demonstrating the practical applicability of these proven conditions. With this study, some conditions existing in the literature are developed and generalized.

(R2113) A Numerical Method For Solving Linear First-Order Volterra Integro-Differential Equations With Integral Boundary Condition, Zelal Temel, Musa Cakir

Applications and Applied Mathematics: An International Journal (AAM)

We investigate an efficient numerical method for the linear first-order Volterra integro-differential equations with integral boundary condition. To solve this problem, boundaries are determined for its derivative and the solution. The numerical solutions of the problem are modeled over a uniform mesh using the composite right-side rectangle concept for the integral component and the implicit difference rules for the differential component. Next, the stability and convergence of the numerical approach are discussed. The numerical experiments are presented confirming the accuracy of the proposed scheme.

Environmental Impact Assessments (Eia): Analysis Of Transboundary Environmental Impact Assessments For The Development Of A Uniform Teia Model, Nicolas Chapa

Open Access Theses & Dissertations

This dissertation investigates the evolution, processes, and importance of Environmental Impact Assessments (EIAs), focusing on transboundary EIAs and the need for a uniform framework. Originating from the National Environmental Policy Act (NEPA) of 1969 in the U.S., EIAs have become globally adopted instruments for assessing and mitigating environmental impacts of development projects. This work reiterates historical milestones, strengths, and current limitations of EIAs. Research also included a review of environmental regulations from Mexico, such as the General Law on Ecological Equilibrium and Environmental Protection (LGEEPA). Through several case studies requiring the use of transboundary EIAs, where shared resources and concerns …

Addressing Ethical Issues In Healthcare Artificial Intelligence Using A Lifecycle-Informed Process, Benjamin X Collins, Jean-Christophe Bélisle-Pipon, Barbara J Evans, Kadija Ferryman, Xiaoqian Jiang, Camille Nebeker, Laurie Novak, Kirk Roberts, Martin Were, Zhijun Yin, Vardit Ravitsky, Joseph Coco, Rachele Hendricks-Sturrup, Ishan Williams, Ellen W Clayton, Bradley A Malin, Bridge2ai Ethics And Trustworthy Ai Working Group

Faculty, Staff and Student Publications

OBJECTIVES: Artificial intelligence (AI) proceeds through an iterative and evaluative process of development, use, and refinement which may be characterized as a lifecycle. Within this context, stakeholders can vary in their interests and perceptions of the ethical issues associated with this rapidly evolving technology in ways that can fail to identify and avert adverse outcomes. Identifying issues throughout the AI lifecycle in a systematic manner can facilitate better-informed ethical deliberation.

MATERIALS AND METHODS: We analyzed existing lifecycles from within the current literature for ethical issues of AI in healthcare to identify themes, which we relied upon to create a lifecycle …

Leveraging Ai Tools In University Writing Instruction: Enhancing Student Success While Upholding Academic Integrity, Daisuke Akiba, Rebecca Garte

Publications and Research

The emergence of AI-powered Large Language Models (LLMs), such as ChatGPT and Google Gemini, presents both opportunities and challenges for higher education, particularly regarding academic integrity in writing instruction. This exploratory study examines a novel pedagogical approach that integrates LLMs as required feedback tools in a university-level psychology writing assignment. The exclusive online approach emphasizes improvement through revision, requiring students to obtain AI-generated feedback on ungraded initial drafts based on an instructor-provided rubric, with final assessment focused on the quality of subsequent revisions. Analysis of survey data from 39 undergraduate students, incorporating both quantitative measures and qualitative responses, revealed several …

Synthesis Of Photocleavable Molecules For Neurological Applications, Nishal Madujith Egodawaththa Arachchilage Don

Theses and Dissertations

In recent biomedical research, the precise control of molecular dynamics through light activation has emerged as a powerful tool, particularly in the field of neurobiology. This approach involves the use of photocleavable cages or photoprotective groups (PPGs) that are chemically tethered to biologically active molecules such as neurotransmitters or calcium chelators. These cages remain inert until exposed to specific wavelengths of light, typically in the visible range, triggering the release of the active compound with high spatiotemporal precision.

For neurotransmitter systems, such as glutamate (Glu), which plays a critical role in synaptic transmission and memory formation, researchers have developed novel …

Novel, Ultra-Fast Electrochemical Sensors For The Enhanced Detection Of Neurotransmitters And Toxic Heavy Metals In Aqueous Solutions, Noel Manring

Theses and Dissertations

Neurodegenerative diseases (NDDs) are a growing global health concern, affecting millions of people worldwide. NDDs arise from the progressive loss of neuronal cell function, ultimately leading to cell death. Abnormal levels of neurotransmitters, the chemical messengers in the brain, have also been linked to NDDs. Despite various treatments and medications aimed at alleviating physical and mental symptoms, there is currently no cure or means to halt disease progression. While the exact pathogenesis of NDDs remain poorly understood, cognitive decline is largely attributed to brain volume reduction, particularly in the hippocampus. Clinical studies suggest that environmental factors, such as exposure to …

Evaluation Of Industrial Hemp Cultivar And Biochar Rate To Remediate Heavy-Metal-Contaminated Soil From The Tar Creek Superfund Site, Usa, Dietrich V. Thurston, Kristofor R. Brye, David M. Miller, Philip A. Moore Jr., Donald M. Johnson, Mike Richardson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Soil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek superfund site in northeast Oklahoma, United States, remains a threat to the environment and local ecosystem. Phytoremediation with industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), biochar rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- (AG) and belowground dry matter …

Comparison Of Statistical And Machine Learning Genomic Prediction Methods In Plant Breeding: Case Studies In Maize And Soybean, Igor Kuivjogi Fernandes

Graduate Theses and Dissertations

Plant breeding is essential to increase genetic gain and food production worldwide. This study was conducted to evaluate new ways to use machine learning (ML) to tackle plant breeding challenges, where two ideas were tested — the first chapter focuses on how to combine genetic and environmental data using ML to improve the prediction of maize grain yield in multi-environment trials, while the second chapter centers on how to couple feature selection of molecular markers with ML to enhance prediction of yield in soybean, and, in both cases, ML approaches were compared to well-established statistical methods greatly adopted by the …

Understanding The Influence Of Traffic And Noise On The Wildlife Community Surrounding Fm106 And Sh100 In South Texas, Anna Rose Mehner

Theses and Dissertations

In South Texas, highways create landscape fragmentation, habitat degradation, and result in wildlife vehicle collisions. Vehicle collisions are the highest known cause of mortality of the endangered ocelot (Leopardus pardalis), which led Texas Department of Transportation to install nine wildlife crossing structures (WCS) on Farm-to-Market 106 and five on State Highway 100. These highways are along Laguna Atascosa National Wildlife Refuge, which is the location of the southernmost breeding population of ocelots in the United States. Many other wildlife species including bobcat (Lynx rufus) and coyote (Canis latrans), are present along these highways and …

Structure Modifications And Alternative Monitoring Designs Of Wildlife Road Mitigation Structures, Madison T. Nadler

Theses and Dissertations

Wildlife mitigation structures are designed to keep animals off roadways while providing them safe passage to the other side and not impeding traffic flow. Camera traps are commonly used to assess the success of these mitigation structures, but there are downfalls to both the methods and structures. Alternative mitigation structure designs are needed to better prevent wildlife from accessing roadways in areas where they should be deterred. Additionally, traditional camera trapping methods do not accurately capture the full wildlife communities that may be utilizing these structures and other survey methods are needed, specifically aimed at small mammals, amphibians, and reptiles. …

Implementing Organic Fertilization Practices To Improve Aloe Vera Growth And Soil Health In The Lower Rio Grande Valley, Isaiah Edward Jaramillo

Theses and Dissertations

Aloe vera (L.) (Aloe) Burm. f., is valued for its applications across the cosmetic, medicinal, and food industries due to its leaf gel. In the aloe industry, the extraction of gel from leaves generates significant quantities of organic waste, which presents an opportunity to repurpose this material as an amendment in aloe cultivation. While Aloe is renowned for its resilience, understanding the feasibility of using these organic shavings as a soil fertility amendment in aloe production is critical. This research aims to identify sustainable fertilization methods for Aloe that can maintain and/or improve crop yield while enhancing soil health. This …

A Nursery Study Of The Interplay Between Soil Texture, Rooting Space, And Nurse Plants On Seedling Growth And Root Development In Woody Species Of Tamaulipan Thornscrub, Lance I. Santos

Theses and Dissertations

Reforestation attempts in semi-arid regions are plagued with seedling mortality. Blanket greenhouse practices may not be optimal, in addition, commensalism interactions between nurse plants are considered. To better understand the effects of soil texture and nurse plant interactions on growth and drought tolerance, two experiments were developed. For soil texture, Border palo verde seedlings were grown in different-sized plant bands with three soil types. To observe the effects of nurse plants, an experiment using guayacan, was developed using Texas Ebony, as a leguminous nurse plant. Plants were also exposed to a drought experiment. The results suggest that some soil textures …

Examining Hispanic Beginning Farmers And Ranchers In The Rio Grande Valley Through A Community Capitals Framework, Perla Kimberly Schrock

Theses and Dissertations

While existing literature addresses the experiences of beginning farmers and ranchers (BFR), there is a notable gap in research focused on Hispanic beginning farmers and ranchers (HBFR). This study aimed at exploring the unique experiences of HBFR in a predominantly Hispanic region, the Rio Grande Valley (RGV), employed the Community Capitals Framework (Flora et al., 2016). I conducted 16 semi-structured interviews with HBFR and local nonprofit organizations and federal employees, complemented by participant observations. Through thematic and content analysis of the interview transcripts, findings revealed valuable insights into the livelihoods of HBFR. Despite HBFR facing significant challenges, this study demonstrated …

Detecting Anomalies In Dynamic Attributed Graphs: An Unsupervised Learning Approach, Austin Hamilton

Electronic Theses and Dissertations

Dynamic attributed graphs, which evolve over time and hold node-specific attributes, are essential in fields like social network analysis, where anomalous node detection is a growing area. Vehicular social networks (VSNs), a subset of these graphs, are ad hoc networks in which vehicles exchange data with one another and with infrastructure. In this dynamic context, identifying anomalous nodes is challenging but crucial for maintaining trust within the network. This work presents an unsupervised deep learning approach for anomalous node detection in VSNs. This model achieved an accuracy of 71% while detecting synthetic anomalies in a simulated network based on real-world …

Physicochemical Property Effects On Immune Modulating Polymeric Nanoparticles: Potential Applications In Spinal Cord Injury, Daniel J. Kolpek, Jaechang Kim, Hisham Mohammed, John C. Gensel, Jonghyuck Park

Markey Cancer Center Faculty Publications

Nanoparticles (NPs) offer promising potential as therapeutic agents for inflammation-related diseases, owing to their capabilities in drug delivery and immune modulation. In preclinical studies focusing on spinal cord injury (SCI), polymeric NPs have demonstrated the ability to reprogram innate immune cells. This reprogramming results in redirecting immune cells away from the injury site, downregulating pro-inflammatory signaling, and promoting a regenerative environment post-injury. However, to fully understand the mechanisms driving these effects and maximize therapeutic efficacy, it is crucial to assess NP interactions with innate immune cells. This review examines how the physicochemical properties of polymeric NPs influence their modulation of …

Assessing Khumbu Region Glaciers Mass Balance Change Using Geospatial Techniques From 2012 To 2024, Yashvi Jagatbhai Shah

Electronic Theses, Projects, and Dissertations

The glaciers in the Hindu Kush Himalaya are critical for sustaining the water supply of South Asia's major rivers, upon which over 230 million people, both in the mountainous regions and lowland areas, depend. Climate change is driving rapid glaciers melt near the summit of Mount Everest, located at an elevation of approximately 7,906 meters (25,938 feet). This has resulted in glacier thinning occurring up to 80 times faster than the original ice formation. However, due to their disposition in a complex topographic setting and inaccessible terrain, continuous glacier observations pose significant challenges.

This study evaluated the mass balance of …

Unraveling Phytosulfokine Trafficking In Arabidopsis Thaliana Using Fiber-Optic Fluorescence Microscopy, Issaka Obuaba

Electronic Theses and Dissertations

As sessile organisms, plants manage stress through complex signaling networks involving phytohormones such as phytosulfokine (PSK). PSK, a disulfated pentapeptide, regulates plant growth, development, and stress responses by interacting with specific PSK receptors (PSKRs). In this study, we explored the trafficking dynamics of PSK, its post-application fate, and the synthesis of an analog. We administered both native PSK and a fluorescent version tagged with TAMRA (5(6)-carboxytetramethylrhodamine) to various Arabidopsis thaliana genotypes, including wild type, a PSKR-deficient mutant, and a strain overexpressing PSKR1 tagged with green fluorescent protein (GFP) over the wild-type background. Fiber-optic fluorescence microscopy revealed that receptor presence influences …

Investigating Phytosulfokine Trafficking: Insights Into The Role Of Phytohormones In Plant Signaling, Martin Tindi

Electronic Theses and Dissertations

Phytosulfokine is a critical signaling peptide involved in plant growth, development, and stress responses. This thesis investigates the trafficking mechanisms of Phytosulfokine (PSK) in Arabidopsis thaliana, employing fluorescently labelled PSK for non-destructive imaging using a custom-built fiber-optic fluorescence microscope. The study aims to determine the mobility and fate of PSK in plant tissues. Experimental results reveal the short-range and long-range movement of PSK across leaves. Additionally, the project highlights the optimization of non-destructive imaging techniques and the synthesis of caged dexamethasone to facilitate optogenetic studies. These findings provide new insights into PSK trafficking mechanisms in plants, enhancing our understanding …

Investigating Nekton Response To Changing Salinities In The Mississippi Sound: An Experimental And Statistical Approach, Adam Murray

Master's Theses

The Mississippi Sound provides nursery habitats for many coastal species and is recognized for its commercial fisheries. Previous freshening events linked to the Bonnet Carré Spillway, a Mississippi River flood diversion structure, proved catastrophic for oyster populations in the Mississippi Sound, but effects on mobile fish and shellfish species are not well-defined. The planned Mid-Breton Sediment Diversion (MBSD), an initiative to combat wetland loss, is also forecasted to lower salinities in the region, increasing the need to better understand responses of commercially and ecologically important species to freshening events. The objective of this study was to characterize effects of salinity …

Decoding Fgf/Fgfr Signaling: Insights Into Biological Functions And Disease Relevance, Oshadi Edirisinghe, Gaetane Ternier, Zeina Alraawi, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast Growth Factors (FGFs) and their cognate receptors, FGFRs, play pivotal roles in a plethora of biological processes, including cell proliferation, differentiation, tissue repair, and metabolic homeostasis. This review provides a comprehensive overview of FGF-FGFR signaling pathways while highlighting their complex regulatory mechanisms and interconnections with other signaling networks. Further, we briefly discuss the FGFs involvement in developmental, metabolic, and housekeeping functions. By complementing current knowledge and emerging research, this review aims to enhance the understanding of FGF-FGFR-mediated signaling and its implications for health and disease, which will be crucial for therapeutic development against FGF-related pathological conditions.

The Application Of High-Resolution Mass Spectrometry For The Analysis Of Biopolymers, Metabolites, And Biologically Relevant Small Molecules, Christ Duc Tran

Graduate Doctoral Dissertations

High-resolution mass spectrometry (HRMS), as its name suggests, possesses high resolving power that enables the separation of ions with very close mass values. This is particularly beneficial for analyzing complex samples where numerous compounds may have similar masses, as it helps prevent signal overlaps and ensures an accurate spectral analysis. The current work explores the diverse applications of high-resolution mass spectrometry in oligonucleotide research, organic synthesis and medicinal chemistry. Oligonucleotide research: Chapters 2-5 present the research results from studies that employed ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) to understand the pharmacokinetics of RNA interference (RNAi) therapeutics. The …

Evaluation Of 3d Beach Profiles: A New Method For Monitoring Changes In Beach Morphology And Grain Size, Kalinda Ellen Roberts

Graduate Masters Theses

Beach profiles are a simple and affordable approach to monitoring changes in beach morphology. However, traditional methods offer limited resolution and dimension. Recent advancements in technologies, particularly structure-from-motion (SfM) and grain size detection models (GSDMs), can be integrated into conventional beach profiling techniques, enabling more detailed spatial and temporal analysis of slope and grain sizes. This research introduces a new technique for coastal monitoring, termed “3D Beach Profiles,” which integrates SfM technology to create high-resolution three-dimensional digital surface models (DSMs) and orthomosaics of beach surfaces. These digital surfaces enable the extraction of beach slopes with orders of magnitude more data …

Thermal Modeling Of Cooling Time Of Submarine Dacite Lapilli Tuff: Brothers Volcano, Kermadec Arc, Kyler Byrd

Master's Theses

Little is known about submarine volcanoes' eruptive histories and styles, even though they are essential to developing island arc systems and represent the second largest volcanic systems on Earth. Scientific drilling allows for the opportunity to study these systems. This study focused on two drill sites on Brothers volcano from IODP Expedition 376: Site U1528, located on the resurgent cone, and Site U1530, located on the caldera rim. Expedition researchers analyzed samples for clast radius, density, thermal conductivity, and specific heat. This data was then entered into the heat transfer equation of a sphere to create a cooling curve model …

Single-Shot Mev-Resolution Hard X-Ray Spectrograph For Cavity-Based X-Ray Free Electron Laser, Keshab Kauchha

Dissertations

The Cavity-Based X-ray Free Electron Laser (CBXFEL) is a possible future direction in the development of fully coherent hard X-ray sources of high spectral brilliance, a narrow spectral bandwidth of ≃ 1 − 100 meV, and a high repetition rate of ≃ 1 MHz. A diagnostic tool is required to measure CBXFEL spectra with a meV resolution on a shot-to-shot basis.

The CBXFEL hard X-ray spectrograph is designed to image 9.831 keV X-rays in a ≃ 200 meV spectral window and with a spectral resolution of a few meV using an LCLS XFEL (Linac Coherent Light Source X-ray Free Electron …

Advancing Biofabrication Methodologies To Develop Biomimetic Tissue Scaffolds For Musculoskeletal Applications, Nashaita Yezdi Patrawalla

Theses and Dissertations

Musculoskeletal injuries impose a significant global burden, affecting millions and generating an economic toll exceeding $14 billion. Tissue engineering has gained traction as a promising strategy offering potential for functional restoration of damaged musculoskeletal tissues. This research aims to advance biofabrication techniques for generation of biomimetic tissue scaffolds, by optimizing scaffold design and modulating fabrication process parameters to generate scaffolds for musculoskeletal regeneration with application-specific tailored properties. In this realm, collagen-based biomaterials have been extensively investigated for tendon and ligamentous applications, and in combination with bioceramics incorporated into the collagen framework to produce composite scaffolds that better recapitulate the native …