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Technical Development, Optimization, And Clinical Implementation Of Quantitative Magnetic Resonance Imaging Methods For Radiation Oncology, Lucas Mccullum

Dissertations and Theses (Open Access)

Magnetic resonance imaging (MRI) has gradually grown more important in the field of radiation oncology. This paradigm shift has grown from initial experiments with MRI of cancerous lesions in the early 1970s, to the integration of MRI images for radiation therapy treatment planning (i.e., MRI-Simulation) in the early 1980s, to the combined MRI linear accelerator (MR-Linac) becoming commercially available in 2018 which can simultaneously image a tumor and treat it with radiation. However, due to its novelty in radiation oncology, its full potential for the integration of quantitative MRI-based biomarkers has yet to be fully realized.

Therefore, this dissertation will …

Membrane Organization Of Rheb And Rhoa: Roles In Function And Allosteric Druggability, Chase M. Hutchins

Dissertations and Theses (Open Access)

Small GTPases of the Ras superfamily are membrane-bound molecular switches that regulate nearly all major cellular processes, and their dysregulation drives cancers, neurological disorders, and metabolic diseases. While anchored to cellular membranes, the catalytic domains of small GTPases undergo orientation dynamics, adopting distinct configurations that can occlude or expose effector-binding surfaces and modulate signaling output. These dynamics have been characterized in the Ras oncoproteins, but whether they extend across the superfamily and influence allosteric druggability has remained unknown.

In this dissertation, I address these questions through Rheb and RhoA, two small GTPases with complementary differences in subfamily lineage, membrane localization, …

Platelet Gαz Regulates Ovarian Tumor Growth And Mediates The Effects Of Chronic Stress, María G. Torres Carrizalez

Dissertations and Theses (Open Access)

Ovarian cancer is the most aggressive gynecologic cancer, with 12,450 estimated deaths in 2026. Elevated platelet counts are commonly observed in patients with ovarian cancer and are associated with enhanced tumor growth and poor prognosis. Patients with ovarian cancer are frequently exposed to elevated levels of stress, which has been correlated with accelerated disease progression and increased mortality. Interestingly, the platelet Gαz protein is activated by epinephrine through the α2A-adrenergic receptor, suggesting a potential mechanistic link between stress signaling and platelet-driven tumor progression. To investigate this, I evaluated the role of platelet Gαz in ovarian cancer using control (Gz^{fl/fl …}

Understanding Epigenomic Landscapes In Cancer Progression And Immunotherapy Response, Jonathan Schulz

Dissertations and Theses (Open Access)

Nonmutational epigenomic reprogramming has emerged as a key hallmark of cancer that plays crucial roles in tumor evolution during its progression and response to therapy. However, the extent and nature of epigenomic reprogramming remains poorly understood. This dissertation examines how epigenetic regulation shapes cancer progression and response to immunotherapy. Working at the intersection of cancer biology and computational genomics, it develops analytical frameworks for characterizing chromatin structure and DNA methylation across diverse tumor contexts and uses these frameworks to address two complementary biological questions: how promoter-associated chromatin organization varies across cancer types, and how epigenetic perturbation modulates tumor immunogenicity in …

An Integrated Framework For Early Detection And Transmissibility Assessment Of Emerging Variants In Wastewater, Xingwen Chen, Tin Phan, Wei Lin Lee, Katie Clark, Steven F Rhode, Samantha Brozak, Bruce Pell, Tsultrim Palden, Mats Leifels, Anna Gitter, Yang Kuang, Stefan Wuertz, Janelle Thompson, Kristina D Mena, Eric J Alm, Fuqing Wu

Faculty, Staff and Student Publications

Tracking the emergence of new viral variants is critical for epidemic preparedness, but remains challenging because variants typically circulate at low prevalence during the early phase of outbreaks. Here, we present an integrated framework that combines sensitive variant detection in wastewater with quantitative assessment of transmissibility through dynamic epidemic modeling. Using the SARS-CoV-2 Omicron variant as a proof of concept, we developed a novel nested allele-specific RT-qPCR assay (NAS-PCR) that achieved a thousand-fold increase in sensitivity compared with allele-specific RT-qPCR (limit of detection: 0.5 copies/μl). NAS-PCR detected Omicron in wastewater samples from the Greater Boston area starting in September 2021, …

Introduction To The Special Issue On Computer Modeling For Future Communications And Networks, Wenbing Zhao, Pan Wang

Electrical and Computer Engineering Faculty Publications

No abstract provided.

Enhancing Reliable Performance Of Microgrids With Autonomous Control Of Distributed Energy Resources, Sahand Liasi

All Dissertations

This dissertation presents a comprehensive investigation into enhancing the reliability, efficiency, and autonomous operation of modern power networks through advanced microgrid integration and control strategies. The research addresses critical challenges across three interconnected domains: microgrid control, thermodynamic modeling of heat recovery system (HRS), and optimal distribution network reliability.

In the realm of microgrid control, this work introduces novel methodologies for grid forming inverter-based resources (IBRs). A significant contribution is the development and validation of an "Auto Frequency Change" controller, which drastically reduces microgrid synchronization time with the main grid from several minutes to approximately four seconds, with theoretical potential for …

Development And Validation Of The Ampere Scale: Measuring Adaptive And Maladaptive Perfectionism In Engineering Students, Haleh B. Brotherton

All Dissertations

Perfectionism refers to the inclination to set very high expectations for oneself, which can at times encourage personal development and at other times lead to stress and a sense of pressure. Perfectionism is widely observed among engineering students; however, instruments that distinguish adaptive striving from concern-driven tendencies in the engineering context remain limited. My study is based on the development and validation of the AMPERE (Adaptive and Maladaptive Perfectionism in Engineering) scale through a three-phase process: (I) expert review with two domain experts to establish content validity; (II) cognitive interviews with seven undergraduates to refine wording and interpretability; and (III) …

Generative Ai Of Breast Cancer Progression In Gene Expression Space, Xusheng Ai

All Dissertations

Breast cancer is one of the most common and deadly cancers in the world. Although doctors can use gene activity data to better understand different types of breast cancer, it is still difficult to identify the most important genes and to track how the disease changes over time. This is partly because gene data are very large and complex.

This dissertation develops a computer-based framework to study breast cancer using gene expression data. The work focuses on three goals: creating realistic synthetic gene data, identifying important genes linked to cancer, and modeling how breast cancer changes from normal tissue to …

Safe Control Design For Quadruped Locomotion In Unstructured Environments Using Linear Transfer Operators, Sriram Sundar Krishnamoorthy Shankara Narayanan

All Dissertations

Deploying quadruped robots in unstructured, obstacle-rich environments requires control and planning methods that remain safe and reliable despite complex terrain geometry, limited sensing, and inevitable modeling errors. This thesis develops operator-theoretic tools for safe control design of robotic systems using linear transfer operators, with a focus on quadruped locomotion in unstructured environments. The central goal is to develop a unified operator-theoretic framework for safe control design based on the Perron–Frobenius (P–F) and Koopman operators. In particular, the thesis leverages \emph{density functions} to develop safe navigation frameworks in the dual space of densities. In the operator-theoretic perspective, the P–F operator governs …

“Do We Belong?”: Supporting Culturally And Linguistically Diverse Students Through Teacher Education, Morohunkeji Orija

All Dissertations

The population of students from diverse cultural and linguistic backgrounds in K-12 education continues to increase, yet the teacher workforce remains largely homogeneous, predominantly White. This imbalance creates a cultural mismatch in educational settings. In teacher education, predominantly White teacher educators prepare predominantly White preservice teachers, further increasing this mismatch. In early childhood education (ECE), which spans birth to 8 years, racial mismatch can lead to misunderstandings and misconceptions, contributing to bias and manifesting as Racial Microaggressions (RMAs). RMAs are mostly unintentional, and research is needed to examine how preservice teachers can identify and address them, given their impact on …

Interplay Between Phase Instability And Deformation Mechanisms In Beta Titanium Alloys In Aggressive Environments, Benjamin Elbrecht

All Dissertations

Modern designs, such as commercial jet turbines, are reliant on the high temperature performance of their constituent materials. Improvements to the strength-at-temperature of materials are critical to the continued advancement of efficiency and payload capacity in these advanced applications. This dissertation presents studies that progress towards this goal through the construction of a new experimental setup for complex temperature and force profiles that also accurately captures deformation behavior through non-contact measurements. Using this setup, studies into two specialty titanium alloys were executed: discovering the microscopic mechanisms responsible for the macroscale behavior and testing in conditions closely replicating aircraft turbine operating …

Monomial Quadratic Identities Of Hecke Eigenforms, Trevor Vilardi

All Dissertations

Duke and Ghate independently studied the question of when it is possible for the product of two eigenforms to be an eigenform. In this dissertation, we take up a generalization of that question, namely is it possible for the product of two eigenforms to be equal to a different product of two eigenforms? Under this formulation, the question becomes closer to one about unique factorization, i.e., how closely do eigenforms work like irreducible elements? Our conjecture is that there are only finitely many cases where the product of two eigenforms is equal to a different product of two eigenforms, and …

Using Large Language Models To Assess Entrepreneurial Personality In Generation Z College Students, Xianyong Wang

All Dissertations

As entrepreneurial personality (EP) plays a critical role in Generation Z’s (Gen Z) long-term success, it is crucial to understand the EP of Gen Z college students. To date, little is known about what EP is and how it can be assessed in Gen Z. Therefore, this dissertation presented two sequential studies to address two closely related research foci. The first study examined the scope and dimensionality of EP in Gen Z college students using topic modeling. In the second study, pre-trained LLMs were fine-tuned to predict self-reported EP levels from personal narrative responses. To collect data, college students (N …

Reimagining Access: Gentrification, Race And Youth Engagement In Outdoor Recreation, Cameron Smith

All Dissertations

Outdoor recreation has proven beneficial for youth, providing mental, social, and physical health benefits that last a lifetime. However, there is a gap in Black and Brown youth's participation in structured outdoor activities due to a multitude of structural factors. An overarching systemic factor that has affected these youths' participation in outdoor recreation is Gentrification, and its derivative, Green Gentrification, which specifically refers to how green amenities and infrastructure drive displacement of long-term communities. As a result of the displacement, Black and Brown youth are placed in a society where they are forced to navigate spaces that were intentionally designed …

The Impact Of Label Material On Perceived Value And Environmental-Friendliness Of Beverages In Returnable Glass Bottles Versus Actual Environmental Impact Via Life Cycle Assessment, Toni Sharp

All Dissertations

With guidance from the EPA to reduce virgin packaging use and alternatively increase reuse, the concept of reusable packaging has re-emerged as a potential sustainable alternative to single-use and recyclable packaging. For businesses, an understanding of the potential environmental benefits of switching from single-use packaging to reusable packaging, along with consumer willingness to pay for sustainable packaging are paramount. Existing literature on willingness to pay (WTP) for ethical or sustainable products typically relies on consumers’ stated preferences found through surveys using hypothetical products and prices. It has been revealed that sustainability claims printed on the label or products in glass …

Assessing Neurodiverse Inclusion In Zoos, Aquariums, And Nature Centers: A Secondary Analysis Of The Mozaics Project, Jennifer N.K. Garcia

All Dissertations

Playful experiences are found to promote positive youth development (Burdette & Whitaker, 2005; Gray, 2011; Sobel, 2018; Watchman & Spencer-Cavaliere, 2017). Additionally, playing in nature can improve attention and mood and reduce stress (Greenleaf, 2014; Kaplan & Kaplan, 1989; Shin & Swank, 2018; Ulrich ,1991). Unfortunately, neurodiverse youth, especially those with autism, can often experience barriers that limit access to play (Pynn et al., 2018; Stern, 2003) specifically play in nature (Barnes, 2007; Wolfberg, 2009). Yet, community organizations that offer playful experiences in nature, such as zoos, aquariums, and nature centers, could be uniquely positioned in the community to support …

Virtual Reality In Informal Education: Trends, Frameworks, And Implementation Strategies, Allison Maynard

All Dissertations

The rapid evolution of immersive technologies presents informal education settings with a complex dual challenge: while virtual reality (VR) offers compelling opportunities for engagement and experiential learning, its adoption demands significant institutional resources and may require a meaningful departure from established interpretive practice. As informal education institutions face decisions about whether to adopt emerging technologies, a critical gap remains in understanding how VR should be designed and integrated to serve both organizational missions and the needs of frontline interpreters and audiences. This dissertation moves beyond the technical novelty of VR to empirically examine its purposeful positioning within informal education settings, …

Baseline Cervical Intervertebral Disc Biomechanics And Implications For Allograft Preservation, Nathan F. Buchweitz

All Dissertations

Neck pain has become an increasingly common orthopaedic healthcare issue. Evidence shows that degeneration of cervical intervertebral discs (the cartilage between the spinal vertebrae in the neck) may be associated. While disc degeneration in the lumbar spine has been extensively studied in relation to low back pain, it has received less attention in the cervical spine. Biomechanically, the cervical (neck) and lumbar (lower back) regions of the spine differ in function. Lumbar discs resist a greater burden of body weight, whereas cervical discs are adapted for mobility to aid flexible head orientation. Despite these key differences, disc injury and degeneration …

Neurobiological Mechanisms Of Attention In Adolescents, Virginia Clark

All Dissertations

Adolescence is a transformative developmental period characterized by profound biological, neurological, and behavioral changes. This dissertation investigates the neurobiological underpinnings of attention in adolescents, emphasizing how internal mechanisms influence and individually shape cognitive development through the endosystem. Rooted in the intersection of human development, learning sciences, and cognitive neuroscience, this work argues for a more integrated understanding of attention as a fundamental cognitive function for learning, one that is behaviorally seen but also biologically and neurologically driven. While developmental science has often emphasized external influences such as family, culture, and environment, this work centers on the adolescent’s internal biological systems …

Sweetly Somatic, Grace Edwards

Graduate Theses and Dissertations

The delight of biting into something sweet. The freedom of getting lost in the movement of your own body. The sensation of being completely enveloped by color. The flutter that rises in your chest when surrounded by abundance. Sweetly Somatic traces personal sensory experience across time, transforming ephemeral moments of joy into forms that capture enduring perseverance. Sculpted from fluxing ceramic materials, piped grout, and glass adornments, the works examine the elasticity of memory, both bodily and retrospectively. My bodily sensations are my most accessible form of joy, and a filter that all experiences move through.

"Because You Speak Two Languages": Latino Immigrant Families Negotiating Language Ideology, Liminality, And Education In Arkansas, Cindy Rauth

Graduate Theses and Dissertations

This dissertation presents a critical ethnographic study of lower socio-economic status, multilingual Latino immigrant families in one region of Arkansas, which has undergone rapid demographic changes in the last four decades. As the Latino population has grown, schools have struggled to accommodate the needs of their diverse students and families, which has contributed to below-grade-level literacy skills and significant student disengagement. This study examines students’ schooling experiences from the perspective of the family. Through an interdisciplinary approach, this study explores three interconnected themes: family experiences of schooling, language ideology, and liminality. A comprehensive examination of family educational experiences includes the …

How Academic Pressure Is Declining The Mental Health Of South Korean Students, Lilyanne Boyland

East Asian Studies

South Korea’s education system is widely recognized for its academic excellence; however, this may highly impact students’ mental health and overall well-being, which can hinder their academic performance. Students are known to dedicate long hours of their day to their education, in addition to their daily academic schedules. This study focuses on how academic pressure, that is mostly driven by parents and educators, as well as traditional cultural values on education, affects the mental health of South Korean students. This thesis is divided into three sections: Historical and Cultural Contexts, South Korea’s Current Educational Environment, and Next Steps for South …

Intersectionality And Belonging: Higher Education Mathematics, Ashley Natalie

Mathematics and Statistics

Students with intersecting marginalized identities (such as race, gender, socioeconomic status, disability, or first-generation background) often face unique challenges in advanced mathematics that affect confidence, participation, amounting to a sense of belonging. These experiences remain underrepresented in mathematics education research. This qualitative, narrative-based study examines how these students experience classroom dynamics and belonging in upper-level mathematics courses. Semi-structured interviews will be analyzed thematically to identify patterns related to identity, classroom culture, instructor behavior, and peer interactions. Findings aim to highlight barriers and supportive practices, informing more inclusive teaching strategies and equitable learning environments in advanced mathematics.

Intersectionality And Belonging: Higher Education Mathematics, Ashley Williams

Mathematics and Statistics

Students with intersecting marginalized identities (such as race, gender, socioeconomic status, disability, or first-generation background) often face unique challenges in advanced mathematics that affect confidence, participation, amounting to a sense of belonging. These experiences remain underrepresented in mathematics education research. This qualitative, narrative-based study examines how these students experience classroom dynamics and belonging in upper-level mathematics courses. Semi-structured interviews will be analyzed thematically to identify patterns related to identity, classroom culture, instructor behavior, and peer interactions. Findings aim to highlight barriers and supportive practices, informing more inclusive teaching strategies and equitable learning environments in advanced mathematics.

Youth In Leadership Positions: A Mediation Program Proposal, Abigail Horn

Sociology

Encountering the justice system can have harmful impacts on a child’s well-being and can lead to negative outcomes in the future, such as missing school and reoffending. This paper proposes a program to combat these impacts by creating infrastructure for schools to handle low level offenses within schools through a mentoring program. After a review of the literature on the current justice system in the United States, rehabilitative and restorative justice practices, and the effects of youth leadership positions, the “Re-Mentoring Program” is proposed. A play on the words "restorative" and "rehabilitative," this program involves youth who have offended, victims, …

Belonging, Ver Ikeseh

Masters Theses, 2020-current

This thesis explores belonging as the core of my artistic practice, developed through public murals and participatory installations in shared spaces. Grounded in a studio practice that engages directly with communities, the work positions art within everyday environments rather than separate from them. Through murals created across James Madison University and within surrounding communities, I examine how public art can generate moments of connection, visibility, and reflection. The thesis culminates in the participatory mural Belonging, created in the Duke Hall Gallery at James Madison University, where these ideas are brought together through direct public engagement. Developed through collaboration, the …

Log Off To Level Up: The Effect Of Social Media Hiatus On Goal Pursuit, Nekysha L. Y. Jalil, Yong Han Tan, Andree Hartanto, Eddie M. W. Tong

Research Collection School of Social Sciences

Concerns are growing that social media, with its constant notifications and attention-grabbing content, may distract individuals and hinder progress toward important goals. Despite its pervasive presence in our lives, the impact of social media on goal achievement has not been thoroughly studied. This within-subject experimental study aims to investigate the effects of social media hiatus (SMH), a short abstinence from social media usage, on goal pursuit processes. Participants (N= 107) completed daily diaries over three consecutive days of SMH and three days of regular social media use. SMH was manipulated by blocking participants’ access to multiple social media platforms. The …

The Effect Of A 14-Day Digital Nudge-Based Sleep Hygiene Intervention On Behavioural, Cognitive, And Emotional Well-Being In College Students: An Experimental Approach, Tracy X. Chen, Chi-Ying Cheng, Michelle Koay, Chin Boon Soh, Andree Hartanto

Research Collection School of Social Sciences

Sleep is essential for one's cognitive, psychological, and physical health. Yet, college students often face sleep deprivation due to academic demands, social obligations, and extracurricular commitments. This study implemented a 14-day Digital Nudge-Based Sleep Hygiene Intervention, delivered via a digital platform, to encourage healthier sleep practices among college students. Grounded in nudge theory, the digital intervention used subtle behavioural prompts to improve participants' sleep hygiene without imposing restrictions, demonstrating high adherence and scalability. Participants were guided through daily tasks to enhance autonomy and motivation, such as creating calming bedtime routines. The digital intervention led to positive outcomes across four domains: …

Brief Virtual Reality And Mixed Reality Mindfulness Breathing Exercise For Emotional Well-Being And Cognitive Functions In University Students: Within-Subjects Experimental Design Study, Zoey Khai Yee Eun, Charmaine Jiali Koh, Hwajin Yang, Adalia Yin Hui Goh, Meilan Hu, K Tennakoon Appuhamillage Sandeeshwara Kasturiratna, Andree Hartanto

Research Collection School of Social Sciences

Background: Mindfulness has been shown to enhance emotional well-being and cognitive performance, yet much of this evidence stems from interventions requiring prolonged practice, making them time-consuming and less accessible. Recent studies suggest that brief mindfulness sessions may also yield positive outcomes, but the effectiveness of such interventions in virtual reality (VR) and mixed reality (MR) remains underexplored. Objective: This study investigates the effects of brief mindfulness breathing exercises delivered through VR and MR on attentional and emotional restoration and self-control capacity. Methods: Using a within-subjects experimental design, 102 undergraduate participants (n=83, 81.4% female; mean age 20.87, SD 1.89) completed a …