Digital Commons Network^™

Low-Cost Carriers Versus Legacy Carriers: Passenger Preference During The Covid-19 Pandemic, Aaron Bushelle

Theses and Dissertations

The purpose of the current study was to identify whether passengers had a preference between traveling on low-cost carriers versus legacy carriers during the ongoing pandemic. Building off research conducted by another researcher, several dimensions were identified and utilized within the question items. For this research, the target population was persons residing within the United States who were at least 18 years old and have traveled since the start of the pandemic in the United States in January 2020. A questionnaire was distributed online, and convenience sampling was undertaken. A T-test was conducted, and results indicated that when it came …

Infrared Electric Field Enhancement Via A Hyperbolic-Metalens-Coupled Nanoantenna, Mohamed Jebril Kyamo

Theses and Dissertations

The development of near- and mid-infrared applications requires high enhancement of the electric field intensity (EFI) and a high absorption cross-section of the electric field. The high enhancement of EFI can be obtained by concentrating optical energy to areas much smaller than the diffraction limit or by using surface plasmon polaritons (SPPs). Noble metals such as gold (Au) or silver (Ag) are not feasible for infrared (IR) applications because of high losses, lack of tunability, low resolution, and low-intensity enhancement. Our methods to solve these problems are based on appropriate metamaterial selection and on coupling systems with optimization of their …

Nanomechanical Characterization Of Vascular Tissue Using Atomic Force Microscopy, Ana Isabel Delgado Peralta

Theses and Dissertations

Cardiovascular morphogenesis and pathophysiology have been associated with the mechanical properties of the vessel wall. In this work, nanomechanical properties of diseased arteries and control groups were quantified using the Atomic Force Microscopy (AFM). Both tip sizes of 20nm and 5µm were used for examining the local and global stiffness. First, we measured the stiffness as a potential index factor of the mice’s aortic aneurysm. Results have shown the stiffness of mice aortic aneurysm is 58.84 ± 30.26 kPa, which is significantly different (P < 0.05) from the stiffness of the control group of 4.70 ± 17.41 kPa. This was attributed to the degradation of elastin fibers and increment of collagen deposition in the vessel as observed in the histological analysis. The lesion heterogeneity was illustrated by the stiffness gradient from 40 kPa to 1.2 MPa within a 2µm2 region. We also examined the stiffness of the diabetic rat aorta as a potential biomarker for disease progression. Results have shown a significantly higher stiffness of 70.25 ± 14.10 kPa in diabetic rat aorta, compared with 54.19 ± 14.15 kPa in the control group. Lastly, we characterized the human aortic calcifications to fill the knowledge gap of scarce datasets for calcification stiffness. Results have demonstrated the calcification stiffness as 61.5 ± 35 kPa, which is significantly larger than the stiffness of the control group of 12.0 ± 4.4 kPa. The stiffness variation was attributed to the percentage of calcium deposits, observed from the histological analysis. These nanomechanical characterizations could be further used for a better understanding of arterial adaptation and to provide insights for effective vascular therapies.

Holocene Human Influence In The Ecuadorean Amazon, Meghan Mary O'Connor

Theses and Dissertations

The extent to which the spectacular biodiversity of Amazonia has been shaped by Pre-Columbian humans is actively debated. Forests that today appear to be pristine wildernesses may have supported complex human societies as recently as 300 years ago. Understanding human history and the potential successional trajectories that result from site abandonment are important to conservation and policy-making. The Yasuni, is famed for its human and biological diversity and yet its pre-history is poorly known. Lake Añangucocha, a small blackwater lake in northwestern Ecuador, is unusual in that it is not a riverine lake, and has the potential to provide the …

Testing The Efficacy Of Uvc Leds For Biofouling Control, Margaret Jeannette Giggie

Theses and Dissertations

The use of ultraviolet-C (UVC) light as a biofouling preventative has been successfully demonstrated using mercury-based lamps. However, these lamps have several limitations (such as fragility and use of mercury), and the use of UVC LEDs (light-emitting diodes) has been suggested as an alternative. Several experiments were conducted to assess the efficacy of LED strips (29 W, 270 nm, emittance angle of 130º) for biofouling control, as well as to compare them to a classic lamp (25 W, 254 nm, emits UVC light at 360º). Experiment #1 assessed the biofouling abundance and community composition on test panels exposed to either …

Quantifying Responsiveness In The Vaccine Industry To Evaluate And Improve Pandemic Response, Connor Hill

Theses and Dissertations

In the wake of the pandemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) we can look at many aspects of the global response, including social, scientific, and governmental. Current research in the areas of vaccine development and manufacturing find the process of developing a new vaccine takes an especially long time and is unresponsive. Understanding the factors that influence responsiveness can help organizations be better prepared to address the needs of society should another pandemic strike. Responsiveness can be linked to product, process, and volume. The vaccine development and manufacturing process historically takes years to reach distribution for public use. …

Cellular Migration As A Function Of Magnetic Field Intervention, Amy Marie Vecheck

Theses and Dissertations

This work aims to assess cellular migration in three-dimensional structures as a function of Zeeman resonance. By using Zeeman resonance to initialize intersystem crossing of electrons, also known as the Radical Pair Mechanism, bioenergetics processes would be modulated. Processes such as oxygen consumption rate and extracellular acidification rate are indicative of cellular respiration and glycolysis and can be altered based on the orientation of the magnetic field applied: parallel and perpendicular, respectively. This study focused on the parallel orientation and looked to used Zeeman resonance to increase flavin adenosine dinucleotide, which results in preventing the breakdown of F-actin. Cellular viability …

Factors Influencing Students’ Achievement In Scientific Literacy: A Secondary Analysis Of Pisa 2018 Data From Saudi Arabia, Manal Dhaifallah Alkhudaydi

Theses and Dissertations

The Kingdom of Saudi Arabia joined PISA for the first time in 2018, and 6,136 of the students in 235 schools participated. The purpose of this multi-level study was to examine the influence of selected student- and school-level factors on students’ scientific literacy using data that were gathered as part of the 2018 PISA assessment. The sample of this study was obtained from the OECD’s PISA 2018 International Database. In this study, the focus was on the relationship between selected factors measured in PISA school and student surveys and students’ scientific literacy, as measured by the Science section of the …

The Impacts Of Holocene Climate And Pre-Columbian Humans On Neotropical Andean Forests, Rachel Kathleen Sales

Theses and Dissertations

Humid montane forests in the tropical Andes form hotspots for biodiversity, endemism, and conservation. Threats to the forests from deforestation are amplified by ongoing climate change, which could further reduce available habitat area by about 57 – 80%. These forests are known to have withstood considerable climate change in the past, and an emerging view suggests that they have also been shaped by a long interaction with people. Although climate-driven species range shifts are broadly known, questions remain about how past climate change has affected the species composition of these forests. The interaction of people with forests on the eastern …

Metabolic Signatures Of Kin Recognition In The Model Angiosperm Arabidopsis Thaliana, Thiara Siqueira Bento

Theses and Dissertations

Many organisms have evolved to identify and respond to differences in genetic relatedness between conspecifics, allowing them to select between competitive and facilitative strategies to improve fitness. Due to their sessile nature, plants frequently draw from the same pool of nutrients, and the ability to limit competition between closely related conspecifics would be advantageous. Over the last 3 decades, significant evidence has accumulated in multiple species that such ‘kin recognition’ (KR) is indeed commonplace in plants. I propose that if KR has evolved, at least in part, as a plant-plant interaction to regulate nutrient uptake, then nutrients should modulate the …

A Spatiotemporal Bayesian Model For Population Analysis, Mohamed Jaber

Theses and Dissertations

Spatiotemporal population analysis based on incomplete, redundant, and unidentified observations is critically important, yet it is a very challenging problem. Different approaches have been proposed and several methods have been implemented to address this problem. Capture-recapture methods have been widely used and have become the standard sampling and analytical framework for ecological statistics with applications to population analysis. Despite the fact that capture-recapture methods have been commonly used, these methods do not consider the spatial structure of the population. Moreover, conventional capturerecapture methods do not use any explicit spatial information with regard to the spatial nature of the sampling and …

Multiscale Optimization Via Multilevel Pca-Based Control Space Reduction In Applications To Electrical Impedance Tomography, Maria Minhee Felicia Monica Chun

Theses and Dissertations

A fully developed computational framework for the optimal reconstruction of binary-type images suitable for various models seen in biological and medical applications is developed and validated. This framework enables solutions to the inverse electrical impedance tomography (EIT) problems of cancer detection at different levels of complexity with multiple cancer-affected regions of different sizes based on available measurements usually affected by noise. A new spatial partitioning methodology and efficient scheme for switching between fine and coarse scales are developed to allow higher variations in the geometry of reconstructed binary images with superior performance confirmed computationally on various models. A nominal number …

Machine Learning Based Surrogate Model For Hurricane Storm Surge Forecasting In The Laguna Madre, Cesar E. Davila Hernandez

Theses and Dissertations

Texas coastal communities are at constant risk of hurricane impacts every storm season. It is especially important to model and predict storm surge variations during hurricane and storm events. Traditionally, hurricane storm surge predictions have been the result of numerical hydrodynamics based simulations. This type of simulations often requires high amounts of computational resources and complex ocean modelling efforts. Recently, machine learning techniques are being explored and are gaining popularity in hydrologic and ocean engineering modelling fields based on their performance to model nonlinear relationships and low computational requirements for prediction. Advances in machine learning and artificial intelligence (A.I.) demand …

Monitoring Of Tool Wear And Surface Roughness Using Anfis Method During Cnc Turning Of Cfrp Composite, Md Mofakkirul Islam

Theses and Dissertations

Carbon fiber-reinforced plastic (CFRP) is gaining wide acceptance in areas including sports, aerospace and automobile industry . Because of its superior mechanical qualities and lower weight than metals, it needs effective and efficient machining methods. In this study, the relationship between the cutting parameters (Speed, Feed, Depth of Cut) and response parameters (Vibration, Surface Finish, Cutting Force and Tool Wear) are investigated for CFRP composite. For machining of CFRP, CNC turning operation with coated carbide tool is used. An ANFIS model with two MISO system has been developed to predict the tool wear and surface finish. Speed, feed, depth of …

Trait Anxiety In The Workplace: A Job Demands-Resources Perspective, Tessly Ann Dieguez

Theses and Dissertations

There is a widely held assumption that anxiety is always bad for job performance, when, in reality, the research findings on anxiety and performance are complex, varied, and inconsistent. Anxiety is extremely common and recently on the rise in the general population, and it can be related to important workplace outcomes such as job performance and well-being. Using the theoretical backdrops of the job demands-resources model (Bakker & Demerouti, 2007, 2018) and the theory of workplace anxiety (Cheng & McCarthy, 2018), this study proposed a model examining the mechanisms through which trait anxiety could lead to lower and higher typical …

Control Of Irradiation Wavelength And Quantum Yield Of Photocleavable Cages, Jingxuan Ma

Theses and Dissertations

An important component of biological research is the precise regulation of biomolecules in their physiological environment. Recent advances in neuroscience, have made it possible to regulate the activity of neurotransmitters using photocleavable protecting groups (PPGs), which are also known as cages. This enables the use of light as a trigger to activate selected neurons via photo release of agonists with precise control of timing as well as synaptic site, popularly referred to as spatiotemporal control. In recent years, a variety of PPGs have been developed and applied to biomolecular cages. PPGs can be classified according to their absorption wavelengths (from …

Computer Vision And Machine Learning Applications In Cellular Images And Clinical Data, Guochang Ye

Theses and Dissertations

With the progressive development of artificial intelligence (AI), automated analysis has been explored for substituting tedious manual methods in cellular image analysis. Additionally, medical information not included in the conventional statistical methods is now being reconsidered with AI-based personalized medicine. The adaptivity and flexibility of AI ensure its efficiency and accuracy. In this work, computer vision and machine learning (ML) methods under the scope of AI are explicitly investigated and applied to cellular images and clinical data for cytological analysis and to provide diagnosis-based assistance/predictions. Firstly, novel computer vision algorithms achieve cell detection and differentiation estimation on phase-contact microscopic images …

The Form And Function Of Cranial Spines In Fishes, Louis Michael Penrod

Theses and Dissertations

Despite the prevalence of fishes that express cranial spines, quantitative investigations into the function of these spines are rare. Function is often assumed with little or no evidence. Commonly, spine-like structures are considered to be used for defense despite spines potentially being used for other purposes. Here, I took a high-level approach to investigate the morphology and potential functions of cranial spines in over 2000 fishes. Identifying the function of cranial spines in fishes not only informs us as to how these fishes interact with conspecifics, with other species, and with their environment, but also may provide advances in human …

Cross-Gender And 1-To-N Face Recognition Error Analysis Of Gender Misclassified Images, Paloma Vela Achu

Theses and Dissertations

A number of recent research studies have shown that face recognition accuracy is meaningfully worse for females than males. Gender classification algorithms also perform worse: one commercial classifier gives a 7% error rate for African-American females vs. 0.5% for Caucasian males. In response to these observations, we consider one primary question: do errors in gender classification lead to errors in facial recognition? We approach this question by focusing on two main areas (1) do gender-misclassified images generate higher similarity scores with different individuals from the false-gender category versus their true-gender category? (2) What is the impact of gender misclassified images …

Age-Related Differences In Food-Specific Inhibitory Control: Electrophysiological And Behavioral Evidence In Healthy Aging, Whitney D. Allen

Theses and Dissertations

The number of older adults is estimated to double from 52 million to 95 million by 2060. Approximately 80-85% of older adults are diagnosed with a chronic health condition. Many of these chronic health conditions are influenced by diet and exercise, suggesting improved diet and eating behaviors could improve health-related outcomes. One factor that might improve dietary habits in older adults is food-related inhibitory control. We tested whether food-related inhibitory control, using behavioral (response time, error rate) and scalp-recorded event-related potential (ERP; N2 and P3 components) measures of food-related inhibitory control differed between younger and older adults over age 55. …

Nm-Rs Au Naturale: Investigations Into Simulating A Natural Environment, Jenna Pantophlet

Theses and Dissertations

Naked Mole-rats (NM-Rs) have been studied in laboratories for decades due to their unique behavior and physiology. However, due to the scope and complexity of the NM-R’s natural subterranean tunneling system, it has been difficult to replicate in the laboratory environment. From a researcher’s perspective, optimal housing is cost- and space-efficient and easily cleaned. On the other hand, optimal animal welfare and husbandry encourages the most biologically relevant enclosure to evoke the fullest range of an animal's behavioral repertoire. While there is an abundance of works centered on the biomedical potential of these odd rodents (Buffenstein et al, 2012; Delaney …

Parenthood Orientation Among Young Women: Is It Associated With Pregnancy Intention And Unprotected Intercourse?, Nakeisha Blades

Theses and Dissertations

This study explored relationships between parenthood orientation, pregnancy intention, and unprotected intercourse. Nulligravid, sexually active women aged 18-29 (N = 252) were surveyed on these topics in May 2019. There were significant differences in parenthood orientation by past and current pregnancy intention. Higher scores on parenthood orientation were associated with increased odds of past unprotected intercourse and expecting future unprotected intercourse. Only education and contraceptive self-efficacy retained significance in adjusted models. Study results are consistent with prior work on parenthood orientation and pregnancy intention and point to other factors as stronger correlates of contraceptive use.

Non-Verbal Pride Expressions As A Predictor Of Lgbtq Health, Craig Gilbert

Theses and Dissertations

Pride is a self-conscious, positive emotion that has been assessed in a wide range of populations and with a variety of pre-validated measures. Research has shown that the presence of pride can function as a potential resilience factor against minority based stress and has been linked to increased emotional well being, life satisfaction, and self-esteem. However, a majority of this research relies upon self-report questionnaires as opposed to observational data. To evaluate the predictive power of non-verbal pride behaviors, a group of LGBTQ+ individuals (n=125) were asked during a recorded interview to describe an experience where they felt prideful about …

Eukaryotic Initiation Factor 4e (Eif4e) In Complex With Eif4e Binding Protein 1 (4e-Bp1) Binds With Higher Affinity To M7gpppn Cap Of A Subset Of Human Mrnas, Izza F. Nawaz

Theses and Dissertations

Fluorescence anisotropy binding assays were used to analyze the binding of eIF4E in complex with 4E-BP1 onto the 5’ m7G cap of a subset of mRNA that are known to carry cap-independent translation. These studies suggest that 4E-BP1 increases eIF4E binding affinity to 5’cap of both FGF-9 and HIF-1𝝰.

Using A Tracer Test To Assess The Fate And Transport Of Nitrate In A Saturated Buffer Zone, Alhassan Sahad Sahad

Theses and Dissertations

The Upper Mississippi Basin (UMB), which includes Illinois, has highly fertile soils and therefore, experiences intensive agricultural practices. While fertile, the soils do not drain well, resulting in the installation of tile-drainage systems. Agricultural practices within the UMB involves the application of nitrogen (N)-rich fertilizers. The tile systems coupled with the application of N fertilizers have led to the excessive export of nitrates as nitrogen (NO3-N) from the agricultural fields into surface and subsurface waters through subsurface tile drainage systems. Excess NO3-N contributes to eutrophication and to development of hypoxic zones in aquatic environments. One method that has exhibited success …

Tidal Translations: Thinking-With Untranslatability In Craig Santos Perez's From Unincorporated Territory, Maryn Gardner

Theses and Dissertations

Craig Santos Perez's poetic series from Unincorporated Territory describes and decries the U.S. militarization, colonization, and environmental degradation of Guam in the Western Pacific through multilingual, excerpted, and series-long poems. Perez's writing style requires slow, careful reading with translations sometimes appearing on the same page, various pages later, or not at all. I describe this kind of elongated translation as slow translation, recalling translation theorist Michael Cronin's "Slow Language" movement. This thesis invites readers, especially multispecies ethnographers, to slow down the translation of nonhuman species and their stories by paying attention to moments of untranslatability in multispecies literature and interactions. …

Bio-Ionic Liquid Functionalized Hydrogels Towards Smart Tissue Regeneration, Vaishali Krishnadoss

Theses and Dissertations

A blend of scaffolds, biologically active molecules, and cells are required to assemble functional constructs to repair and regenerate damaged tissue or organ via tissue engineering. The scaffold supports cell growth and proliferation and acts as a medium for diverse cellular activities. Even though hydrogel's high-water content and flexible nature make it a pronounced applicant as a scaffold, they exhibit significant technical limitations such as the absence of cell-binding motifs, lack of oxygen, conductivity, adhesive properties, growth of cells in a 3-dimensional (3D) microenvironment. In this thesis, a novel material platform is evaluated and studied to address the concerns mentioned …

Conceptualization Of Steam Education In The Elementary Classroom, Virginia Olmert Mccullough

Theses and Dissertations

Science, Technology, Engineering, Art, and Mathematics (STEAM) education is an instructional approach to education in which students demonstrate creative approaches in experiential, inquiry-based learning within the STEM disciplines. Despite the national focus on STEAM education, there exists considerable uncertainty as to what constitutes STEAM education and how classroom educators make sense of their conceptualization of STEAM in their classroom within the state of Georgia.

The method of conceptualization is the internal processing of thoughts that produce new ideas or knowledge. This descriptive case study offers thoughtful new insights on how educators in a STEAM-certified elementary school in a school district …

Assessing Augmented Reality Instruction In Manufacturing Engineering Education, Janine Draper Price

Theses and Dissertations

Augmented Reality (AR) is fast-growing technology that has proved itself in many applications, including manufacturing environments. Manufacturing engineers benefit in an industrial environment by harnessing this technology in the workplace to guide workers through a variety of tasks. It is no longer a question on whether it is useful, but what are the best ways of applying the technology. Currently there are no published studies on ways to use augmented reality in a Manufacturing Engineering Educational Environment (MEEE). This study examines various ways that AR can be used in an MEEE setting and assesses the value of such applications. This …

Mindfulness And Observational Drawing, Corinne Christopherson Sonderegger

Theses and Dissertations

Observational drawing has many benefits, yet it can be a difficult and frustrating curriculum for students and teachers alike. As I was teaching elementary and college art classes simultaneously, I noticed a significant discrepancy between my younger and older students. Students in my elementary art classes loved to draw and often expressed how excited they were to make art. However, students in my college art classes were more hesitant and self-conscious about drawing and did not believe they could progress artistically. Many of these students had abandoned drawing in elementary or middle school. This pattern evokes the U curve of …