Digital Commons Network^™

A Phenomenological Study Of Science Teachers’ Lived Experience: Pedagogical Judgment During The Covid-19 Pandemic, Amy Vo

Electronic Theses and Dissertations

At the beginning of the COVID-19 pandemic, in March of 2020, education in the United States changed dramatically. Science teachers began to look at the implementation of ambitious and equitable science teaching practices differently. Employing the hermeneutic phenomenological framework, the purpose of this study was to investigate the lived experience of science teachers, specifically looking at their pedagogical judgment related to ambitious and equitable science teaching. Semi-structured interviews, artifacts and surveys were used to develop a rich description of the phenomenon. Data analysis of the science teachers’ narratives, Qualtrics surveys, and lesson plans illuminated six essential themes common to all …

Mechanistic Insights Into Mftr-Dependent Regulation Of The Redox Cofactor Mycofactocin, Aigera Mendauletova

Electronic Theses and Dissertations

Organic redox cofactors are essential for life. While classic flavins and nicotinamides are widely distributed across all domains of life, nature has also evolved niche cofactors in subsets of life domains. For example, in Actinobacteria, coenzyme F420 is commonly used in place of flavin mononucleotide in enzymes associated with carbon fixation and oxidation of secondary alcohols. The importance of niche cofactors has long been recognized however, detailed understanding about their biosynthesis and physiological uses has been lagging. One class of niche cofactors is derived from ribosomally synthesized and posttranslationally modified peptides (RiPPs). To achieve their mature form, the genetically …

Artificial Emotional Intelligence In Socially Assistive Robots, Hojjat Abdollahi

Electronic Theses and Dissertations

Artificial Emotional Intelligence (AEI) bridges the gap between humans and machines by demonstrating empathy and affection towards each other. This is achieved by evaluating the emotional state of human users, adapting the machine’s behavior to them, and hence giving an appropriate response to those emotions. AEI is part of a larger field of studies called Affective Computing. Affective computing is the integration of artificial intelligence, psychology, robotics, biometrics, and many more fields of study. The main component in AEI and affective computing is emotion, and how we can utilize emotion to create a more natural and productive relationship between humans …

A Study Of The Cultural And Geological Environment Of The Magic Mountain Site In Golden, Colorado, Brianna K. Dalessandro

Electronic Theses and Dissertations

The Magic Mountain site, located in Golden, Colorado, has been the subject of intensive academic studies since the 1950s because of its extensive artifact assemblage and long habitation periods. The aim of this thesis was to use ground-penetrating radar, magnetometry, GIS models, and lithic analysis to further study when and how the Magic Mountain site was used during prehistoric times and contextualize a variety of hypotheses about site habitation and migratory patterns of prehistoric people in Colorado.

The results of these analyses indicate the habitation and migratory pattern of the Magic Mountain site was a periodic, but consistent, proximal visitation …

Elementary Preservice Math Teachers’ Evolving Dispositions Throughout A Math Methods Course: A Mixed Methods Study, Christine E. Hood

Electronic Theses and Dissertations

This study aimed to understand graduate-level Elementary Preservice Teachers’ (EPST) mathematical dispositions before, during, and after a graduate elementary math methods course taught through a rehumanizing (Gutiérrez, 2018), ambitious and equitable math (Horn & Garner, 2022) teaching framework. In this study, EPSTs’ dispositions included four constructs: math anxiety, math teaching anxiety, math self-efficacy, and math teacher self-efficacy. To fully understand the nuance and complexity of teacher education and EPSTs’ mathematical dispositions, I looked at both the EPSTs' and the instructors' perspectives. I investigated EPSTs’ dispositions through a modified multi-methods, sequential, and phenomenological lens. For the instructors’ perspectives, I conducted a …

Plant Community Response To Control Of A Dominant Invader At Multiple Scales, Alexander R. B. Goetz

Electronic Theses and Dissertations

Control of invasive Tamarix spp. in riparian systems has long been a priority for management in western North America, but questions remain regarding the response of the broader plant community to different treatments. Here we summarize a series of approaches at different scales to quantify the effects of Tamarix control on characteristics of this ecosystem, including provisioning of wildlife habitat. In the first chapter we analyzed findings of the last 20 years using meta-analysis and found that although treatment has been successful in reducing Tamarix and promoting native vegetation to some extent, most literature reports very small effect sizes and …

Problems With Machine Learning, High-Dimensional Data And Forecasting Stock Returns, Erik Mekelburg

Electronic Theses and Dissertations

Using a multi-level ensemble design, we forecast international stock market returns with a novel high-dimensional data set of aggregated cross sectional firm-level predictors. The method includes considerations of model uncertainty, parameter instability, model density and non-linearities with machine learning, shrinkage and model averaging. We provide evidence that it is important to systematically focus on all four sources of forecast failure, shed light on the sparsity/density debate in the stock return forecasting dialogue and contribute interesting findings on the efficacy dimensionality reduction with principal components analysis and partial least squares. The robustness of the approach is demonstrated through applications in four …

Developing Red Fluorescent Zn2+ Sensors And Characterizing Zn2+ Homeostasis In Mucolipidosis Type Iv Disease, Anna M. Dischler

Electronic Theses and Dissertations

Zinc (Zn²⁺) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn²⁺ levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn²⁺ signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn²⁺ sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular …

The Evolutionary Causes And Consequences Of Mammalian Hybridization, Kelsie E. Hunnicutt

Electronic Theses and Dissertations

The natural recombination of divergent genomes within hybrid offspring provides windows through which we can study evolutionary processes and the dynamics of speciation. In this work, I use a combination of comparative and population genomics on both laboratory crosses of divergent rodent lineages and a hybrid zone of cottontail rabbits in the wild to study the causes and consequences of hybridization in mammals. Hybrid sterility is a common reproductive barrier between species that tends to preferentially manifest in the heterogametic sex and frequently genetically maps to the sex chromosomes. Thus, the sex chromosomes appear to play a special role in …

A Participatory Drone Mapping And Critical Physical Geography Of Water Security For Irrigation In Northern Ghana, Dinko Hanaan Dinko

Electronic Theses and Dissertations

Dam discourse frequently incorrectly assumes that their emergence unilinearly translates to an expansion of economic opportunities while not considering how dams become sites for the reproduction of inequality and injustice. This dissertation investigates how the politics of irrigation water access are nested in a complex web of physical materialities of the 'natural' environment and power relations, with lived consequences on differentiated social identities in semiarid Ghana. The research draws on transdisciplinary perspectives from political ecology, embodiment, critical physical geography, and mixed methods, including interviews, focus group discussions, surveys, participatory drone mapping, and laboratory analysis of soil biochemical properties. The study …

Terrain Cost Learning From Human Preferences For Robot Path Planning Using A Visual User Interface, Kaivalya Velagapudi

Electronic Theses and Dissertations

Robot navigation in terrains with limited exploration and limited knowledge has been a problem of interest in robotics due to the potential dangers that may arise during traversal. Due to the large number of path permutations within a complex and feature-rich real-world environment, and in the interest of saving time and ensuring safety, the robot should learn the optimal path without repeated exploration of the terrain. This can be accomplished by leveraging the path preferences of a human operator so that, with selective inputs, the agent can effectively learn a terrain-cost mapping in order to determine the optimal route, thereby …

Post-Translational Modification Of Proteins Via Ambient Air Pollutants And Endogenous Reactive Species, Rachel Lauren Davey

Electronic Theses and Dissertations

Proteins can react with reactive oxygen species (ROS) and reactive nitrogen species (RNS) to form post-translational modifications (PTMs), which can affect protein structure and function. The formation of 3-nitrotyrosine (NTyr) and dityrosine (DiTyr) upon reaction of proteins with ROS/RNS are two common PTMs studied due to their stability and irreversibility, as well as their ability to enhance the allergenicity of pollen allergens upon formation. Many common techniques used to study the formation of these PTMs can reliably detect the PTMs but can only provide semi-quantitative information due to many assumptions and limitations. In Chapter 2 we present an analysis of …

Identifying The Role Of Phospholipase D1 And Phosphatidic Acid In Exocytosis, Broderick L. Bills

Electronic Theses and Dissertations

Exocytosis is an essential process for intercellular communication in eukaryotic cells. This process involves significant changes in membrane curvature, and lipids and curvature-sensing proteins can assist these processes. One protein in particular, phospholipase D1 (PLD1), and its product, the lipid phosphatidic acid (PA), are involved in multiple exocytic processes. However, PLD1 and PA’s role in this process has remained unclear. In this work, PLD1 and the production of PA were visualized during exocytosis, and PA localization to regions of membrane curvature was established. Together, these results support the hypothesis that PLD1 production of PA stabilizes negative curvature during membrane fusion. …

Islamic Studies Teachers' Perspectives Of Applying Technology In Saudi Arabia Elementary Schools, Amal Abdulmohsen Alsaif

Electronic Theses and Dissertations

In recent years, the use of technology in education has been on the rise around the world, and Saudi Arabia is no exception. The integration of technology in Saudi education has the potential to enhance the quality of education, increase access to education, and provide students with the skills they need to succeed in a rapidly changing world. It also has the potential to facilitate collaboration between students and teachers, both within and outside the classroom, and to promote lifelong learning.

The purpose of this qualitative study is to investigate Islamic Studies teachers' perceptions of using technology in their classrooms …

Water Literacy In Drought-Prone Regions: Case Studies From Aurora, Colorado, Usa And Cape Town, Western Cape, South Africa, Meghan Mccarroll

Electronic Theses and Dissertations

Water managers around the world must reevaluate their approach to water security as challenges continue to grow. Supply-focused paradigms that aimed to capture, control, and commodify water resources are increasingly unreliable and often depend on environmentally and socially damaging practices. Of particular concern are regions experiencing climate shocks and aridification from rising global temperatures. In order to stretch limited water resources using equitable water policies, conservation programs, and alternative water sourcing, water managers must invest in a water literate citizenry. Water literacy is the culmination of water-related knowledge, attitudes, and behaviors. The benefits of a water literate citizenry abound, including …

Tactical Allocation Through The Lens Of Correlational Time-Variance, Determinants, And Regimes, T.H. Williams

Electronic Theses and Dissertations

We investigate correlations among six primary asset classes from January 1982 to December 2022. Our analysis extends existing literature, on the well-researched stock-bond correlation (SBC), by encompassing 14 supplementary asset class dyads and four correlational regimes. We challenge the archetype of correlational time-invariance that underlies buy-and-hold asset allocation strategies by implementing structural break tests and an innovative Wavelet Coherence (WC) methodology, where our findings reveal temporal instability. Through a multi-method statistical approach, we present robust and persuasive evidence of macroeconomic factors as determinants of temporal change. Leveraging time-varying Granger causality, we unearth elusive yet significant relationships. Our research pivots to …

How Practices Drive Persistence: The Transformational Consumption Journey Of Native Americans In Higher Education, Gwen Locklear Almodovar

Electronic Theses and Dissertations

In an academic environment where many higher education institutions tout their diversity and inclusion statistics, there is a decline in the enrollment of Native American students and a decrease in Native American scholars. The President of the United States, in an October 2021 briefing and with the issuance of an executive order named The White House Initiative on Advancing Educational Equity, Excellence, and Economic Opportunity for Native Americans and Strengthening Tribal Colleges and Universities, saw the immediate urgency to understand the systematic causes and implement evidence-based strategies that will improve and increase student enrollment and academic advancement. This research takes …

Optimal Management And Sizing For Battery Energy Storage Systems For Grid Applications, Abdullah Muslih Alharbi

Electronic Theses and Dissertations

Battery energy storage systems (BESSs) play a dominant role in the reliability, resiliency, economics, and operational flexibility of the power grid. As such, the BESS is a promising and reliable green technology for supporting power grid facilities. However, the integration of BESS technology into power projects can be expensive and challenging, both technologically and in terms of regulation compliance. Thus, it is necessary to examine best practices for fully optimizing BESS sizing, operation, and scheduling in the context of benefiting BESS operators and investors by fully exploiting the valuable economic and technical benefits of BESSs. In this research, we identify …

Adversarial Explanations For Text-Based Local Surrogate Models, Christopher Burger

Electronic Theses and Dissertations

LIME has emerged as one of the most commonly referenced tools in explainable AI (XAI) frameworks that is integrated into critical machine learning applications–e.g., healthcare and finance. However, its stability remains little explored, especially in the context of text data, due to the unique challenges when it comes to perturbing the underlying data, data that requires a stricter measure of semantic and syntactic consistency. To address these challenges, we first evaluate the inherent instability of LIME on text data to establish a baseline, and then propose a novel algorithm XAIFOOLER to perturb text inputs and manipulate explanations that casts investigation …

Enhanced-Entropy Chaotic Circuit Design For Overhead-Constrained Hardware Security Applications In Integrated Circuits, Partha Sarathi Paul

Electronic Theses and Dissertations

This document presents a Ph.D. dissertation that focuses on designing overhead constrained circuits for chaos-based hardware security applications in integrated circuit (IC) technology. The designed circuits are optimized for promising chaotic behavior while maintaining the constrained area, delay, and power budget. This research includes proposing novel circuit topologies for attaining superior chaotic complexity, analyzing chaotic performance with multiple metrics, proposing the designs for real-world hardware-security applications that leverage proposed circuit topologies, and analyzing the security aspects of the designed applications. Multiple circuit design techniques are presented in this document. All the proposed works fall under the central motivation of designing …

Sustained And Improved Ophthalmic Formulations Of Gatifloxacin For Better Therapeutic Outcomes During Topical Ocular Applications, Poorva Hemant Joshi

Electronic Theses and Dissertations

Gatifloxacin (GTX) is a broad-spectrum 4th generation antimicrobial fluroquinolone used in the treatment of ocular infections such as conjunctivitis, keratitis and keratoconjuctivitis. GTX (as a sesquihydrate) is commercially available as aqueous eyedrops for the treatment of bacterial conjunctivitis (BC) which requires frequent administration due to low residence time on the conjunctival surface. The eye is a highly specialized photoreceptive organ, which is protected by a continuous tear flow containing antibacterial components. However, inflammation or scarring of the eye may be difficult to resolve once having occurred. Furthermore, initial infections if ignored are likely to invade the inner portions of the …

Lipid Based Ophthalmic Nanoformulations For Ciprofloxacin, Moxifloxacin, And Cannabidiol, Ahmed Adel Ali Youssef

Electronic Theses and Dissertations

Ocular drug delivery faces many challenges due to the unique anatomy and physiology of the human eye. The development of ocular drug delivery systems is subjected to a gradual shift from an empirical to a rational base due to a better understanding of the ocular barriers that control drug disposition in the eyeball as well as new approaches in clinical testing. Most of the topically applied actives are lipophilic with low aqueous solubility, and the ocular delivery of these drugs is posing a challenging task. Lipid-based drug delivery systems are well reported to improve solubility and enhance both bioavailability and …

Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson

Electronic Theses and Dissertations

One of the most significant shifts in the mix of U.S. electricity generation over the past few years has been the rapid expansion of renewable energy resources, especially solar and wind. However, fossil fuels are still necessary to fulfill the world’s energy requirements. Despite efforts to increase the use of renewable energy sources, these sources can be at times unreliable, causing countries around the world to continue to rely on base load units such as coal and natural gas. This decrease in fossil fuels and increase in renewable energy sources presents many complex issues in terms of power system planning, …

Quantifying The Effects Of Hvac Operation To Mitigate Aerosol Concentration In A Classroom Using Cfd, Scott Deprez

Electronic Theses and Dissertations

Heating, ventilation, and air conditioning (HVAC) is a complex mechanical system for the transition of air between outdoor and indoor areas. These systems are directly responsible for temperature, humidity, and air flow into any given space, thereby providing a level of comfort to those who live indoors. These systems account for 52 percent of U.S. energy consumption. When designing HVAC systems, indoor air quality (IAQ) is the main focus for achieving safe and clean air, such as in the case of airborne diseases. HVAC systems are responsible for the flow of air in indoor spaces and thereby expand the transmissible …

Evaluation Of Low-Cost Radiometer For Surface Reflectance Re-Trieval And Orbital Sensor’S Validation, Dinithi Siriwardana Pathiranage

Electronic Theses and Dissertations

This paper evaluates the Arable Mark 2 sensor, an automated and low-cost radiometer, for its potential to retrieve surface reflectance data and validate orbital sensors such as the Landsat-8 (L8) Operational Land Imager (OLI) Level 2 product. While orbital sensors are widely used for monitoring solar radiation changes, managing natural resources, and understanding climatic trends, atmospheric effects can make it challenging to obtain accurate measurements. Equipped with multiple sensors, including long-wave and short-wave radiometers, the Arable Mark 2 sensor can measure upwelling and downwelling irradiance to calculate surface reflectance. To assess the accuracy and consistency of the Arable Mark 2 …

Seroprevalence Of Sars-Cov-2 Antibodies Among Rural Healthcare Workers, Jordan Neises

Electronic Theses and Dissertations

The objective of this longitudinal cohort study was to determine the seroprevalence of antibodies to severe acute respiratory syndrome coronavirus-2 (SARSCoV- 2) in healthcare workers employed at healthcare clinics in three rural counties in eastern South Dakota and western Minnesota from May 13, 2020 through December 22, 2020. Three blood draws were performed at five clinical sites and tested for the presence of antibodies against the SARS-CoV-2 virus. Serum samples were tested for the presence of antibodies using a fluorescent microsphere immunoassay (FMIA), neutralization of SARS-CoV-2 Spike-pseudotyped particles (SARS-CoV-2pp) assay, and serum virus neutralization (SVN) assay. The seroprevalence was determined …

Quantitative Change Analysis Of Undisturbed Lands In Eastern South Dakota: 2012-2021, Riley W. Wollschlager

Electronic Theses and Dissertations

The actual rate of loss of undisturbed prairie and woodland in eastern South Dakota is unknown, and the landscape composition of the region continues to change. Undisturbed land is land with no proven prior cropping or other disturbance history. Agriculture, development, recreation, and other land use practices create disturbances resulting in the further conversion of undisturbed prairies and woodlands. Previous work by South Dakota State University (SDSU) quantified the remaining undisturbed land in eastern South Dakota as of 2012 (Bauman et al 2016). Farm Service Agency (FSA) common land unit (CLU) and National Agricultural Imagery Program (NAIP) imagery were the …

A Study Of The Local Deep Galerkin Method For The Modified Cahn Hilliard Equation, Shi Wen Wong

Electronic Theses and Dissertations

Solving higher order partial differential equations (PDEs) can often prove to be a challenging task due to the involvement of higher-order derivatives of the unknown function, particularly for complex problems. The higher the order of the PDE, the more challenging it becomes to obtain an analytical solution. In such cases, alternative numerical methods are often used, such as finite element method or finite difference method. However, these methods can be computationally expensive and require a significant amount of mathematical expertise to implement. In recent times, there has been significant progress in applying neural networks to various fields, including the solution …

Impact Of Virtual Fence Technology On Yearling Steer Behavior, Performance, And Energetic Expenditure, Logan Riley Vandermark

Electronic Theses and Dissertations

Beef cattle production in the U.S. is largely dependent upon extensive rangelands like the Northern Great Plains. Solutions are needed to meet both the demand of animal-based protein products for a growing world population and the desire for producers to manage for several different ecosystem functions. Virtual fencing (VF) is an emerging precision technology that has the potential to revolutionize livestock management on extensive rangeland systems. However, the need to quantify animal behavior and performance differences using emerging precision technologies, like VenceTM, is ever growing. Thus, the objective of this research was to determine the impact of virtual fencing on …

Modulatory Effects Of Deacetylated Sialic Acids (A Sugar Residue) In Nk-Mediated Cytotoxicity And Targeted Therapy By Receptor Tyrosine Kinase Inhibitors, Mathias Tawiah Anim

Electronic Theses and Dissertations

The complex nature of the biology of cancer is still an unraveling science, yielding several biomarkers that have served as molecular targets for detection and treatment of the disease. How sugars, glycans, play a role has remained relatively uninvestigated. Sialic acid (Sia), a sugar residue on the surface of cells, has been identified as a hallmark of cancer and its progression. Sialic acid can be highly functionalized, but we became interested in acetylated Sias. This functional group is modulated by Sialate O- acetylesterase (encoded by the gene SIAE) and Sialate O-acetyltransferase (encoded by CASD1), enzymes that play a crucial role …