Doctor of Philosophy (PhD), Ohio University, 2007, Computer Education and Technology (Education)

This study examined the relationship between students' perceptions of interaction, gender, age and students' satisfaction with course and students' grades. The data were collected using a Web-based survey from 65 students enrolled in an online humanities course in a Midwestern community college. Multiple regression analysis was used to analyze data. Results indicated that neither perceived personal interaction (participation) nor age accounted for a significant amount of variation in the dependent variable, satisfaction with the course. The most important predictor of students' satisfaction was perceptions of overall interaction, followed by gender. The regression model with the two predictors was significant. Male students who perceived the overall interaction in the course to be high were more satisfied with the course. No significant correlations were found between perceptions of interaction and course grades. Gender and age were not significantly correlated with course grades. The regression model with four predictors, perceptions of personal and overall interaction, gender, and age, was not significant. The key predictor of students' satisfaction with the course was not the extent to which students participated in the interaction that was occurring in the course, but rather their perception that there was much interaction in the course. This relationship between perceived overall class interaction and course satisfaction serves as an indicator of “vicarious learning,” or learning that takes place when a student actively observes and benefits from interaction among the other students, or between students and the instructor. Students who would not initiate interaction on their own can still learn from observing class interactions.

Doctor of Philosophy, The Ohio State University, 2010, EDU Policy and Leadership

A quasi-experiment was carried out in a college success strategies course to evaluate the impact of structured interpersonal interaction on undergraduate students' Academic Engagement and Academic Achievement. The course, EPL 259: Individual Learning and Motivation, employs a blended learning instructional model – Active Discovery and Participation through Technology (ADAPT; Tuckman, 2002) – that requires students to spend the majority of class time working independently on online activities. In the quasi-experiment, students in six treatment sections were exposed to some combination of two types of interpersonal interaction: Student-Student Interaction and Student-Instructor Interaction. Student-Student Interaction was facilitated in two different formats: (1) through in-class, cooperative learning activities, and (2) through online, asynchronous discussion board activities. Two sections of EPL 259 received the first Student-Student Interaction format, two sections received the second format, and two sections received neither format. In addition, in each of these three pairs of sections, one section also received Student-Instructor Interaction, facilitated through weekly, one-on-one meetings between each student and his or her instructor. The desired outcomes, Academic Engagement and Academic Achievement, were each measured in two ways. Academic Engagement was measured: (1) through analysis of data on students' course-related behaviors, including rates of attendance, tardiness, submission of assignments, and late submission of papers, and (2) through students' scores on a multifactor survey of course engagement. Academic Achievement was measured: (1) through total points earned on written assignments and online activities, and (2) through grades on the comprehensive final examination. A series of Analyses of Covariance (ANCOVAs), utilizing participants' Prior Cumulative GPA and measures of Conscientiousness and Extraversion as covariates, was carried out to assess (open full item for complete abstract)

Doctor of Philosophy (PhD), Wright State University, 2015, Engineering PhD

Streamwise vortex-surface interactions can occur in aviation intentionally in the context of formation flight as an energy saving mechanism, unintentionally in wake crossings when aircraft fly in close proximity, and as a consequence of aircraft design through the interaction of fluid dynamics between different aerodynamic surfaces. The bulk of past work on streamwise vortex-surface interactions has focused on steady inviscid analysis for optimizing aerodynamic loads in the context of formation flight or experimental analysis on fin buffeting problems. A fundamental understanding of the viscous and unsteady effects that may occur is both important and currently lacking in the literature. This dissertation seeks to fill this need by using a high-fidelity implicit large-eddy simulation approach coupled with geometrically non-linear finite elements to identify and analyze important physics that may occur. Simple, canonical configurations are employed in order help disentangle the many interrelated factors of a very complex problem. Analysis of a tandem wing configuration elucidated mutual induction between the incident vortex from the leader wing and tip vortex of the follower wing that resulted in a broad taxonomy of flow structure, wake evolution, and unsteady behaviors for several lateral impingement locations. Interaction of an isolated streamwise vortex with a wing revealed a robust helical instability develops when a strong vortex impinges directly with the leading-edge. This spiraling behavior was found to occur as a result of the upstream influence of adverse pressure gradients provided by the wing that drive the vortex into its linearly unstable regime allowing for the growth of shortwave perturbations. Stability can be augmented through vertical positioning of the vortex. A negative offset can enhance stability by providing a stronger adverse pressure gradient while a positive offset exploits a favorable gradient and removes the upstream instability altogethe (open full item for complete abstract)

Doctor of Philosophy, University of Toledo, 2007, Curriculum and Instruction: Educational Technology

Course management systems (CMS) are widely used in higher education to deliver courses completely at a distance. Although research suggests learning is influenced by social interaction, there is comparatively little research on why and how students enrolled in a CMS-based, fully online course interact with their peers. A review of the literature suggests the history of distance education is primarily constructed of applied practice, largely unchanged throughout periods of technological innovation. The purpose of this study is to discover students' perceptions of social interaction among peers enrolled in a university-level, fully online, CMS-based course. An online survey provided an objective measure of peer interaction. The results revealed hierarchical patterns in reasons for interaction, communication methods used, and the perceived value of interaction in academic success. The study also revealed significant demographic differences regarding reasons for interaction and communication methods used. Content review suggests students have a strong interest in how instruction is provided online. Improvement in learning skills, communication literacy, and information literacy are recommended to increase online learning outcomes. Additional research is suggested to expand the knowledge of distance education.

Master of Fine Arts, The Ohio State University, 2009, Industrial, Interior, and Visual Communications Design

Gestures play important roles as facilitators of language development, temporal-spatial learning, and non-verbal communication. Gesture-based interaction design seeks to capitalize on this natural method of human communication by using gestures as a means of interfacing with digital content. While technological factors address important issues related to sensing gestural input, design factors are the most critical factors relate to developing useful and approachable gesture-based interactivity. The goal of this research is to articulate more clearly some intrinsic characteristics of gesture that are significant to gestural interface designers, while providing methodologies that designers can use to gather and implement this information in a fashion that suits their unique design processes. Gesture researchers have published a great deal of research that has significant implications related to gestural interface design, but most research in the field of gesture studies relates to gestures that are produced in combination with speech or in place of speech. Directly applying this research to visual interface design is difficult because many of the examples of gestures provided by these researchers analyze gesture in terms their linguistic characteristics. Because interface designers are seeking gestures that can be incorporated into interactive scenarios, there is a need for example of gestures produced in response to visual-spatial cues. The aim for this study and beyond is to create a library of gestures that can serve as a reference to designers who are seeking visual-spatial representations of a broad range of gestural expression. This study presents methods of visual and spatial contextualization that can be applied or expanded upon by gestural interface designers who are seeking to build unique gestural vocabularies on a project-by-project basis. This document outlines a pragmatic approach to gestural interface design that aims to inspire designers toward further (open full item for complete abstract)

Doctor of Philosophy, Miami University, 2005, Chemistry and Biochemistry

Noncovalent weak interactions such as pi-pi, lone pair-pi and C-H...O hydrogen bonding have been studied experimentally. Triptycene-derived model compounds serves as conformational equilibrium reporters for direct measurements of these interactions. For arene-arene interactions in the parallel-displaced orientation, a series of triptycene derivatives bearing 1, 9- arenes with different substituents were synthesized and the ratios of syn to anti conformers were determined in terms of low-temperature NMR spectroscopy. The free energies of the interactions were then derived from the syn/anti ratios. Two possible mechanisms are suggested for off-set arene-arene interactions. For the systems with a moderate electron donor and electron acceptor, electrostatic forces are believed to control the arene-arene interactions. The interactions between the arenes bearing electron-donating groups (EDG) are found to be either negligible or slightly repulsive, while the interactions between arenes with electron-withdrawing groups (EWG) are attractive. However, for the systems with one strong electron acceptor such as pentafluorophenyl, the interactions are found always attractive regardless of whether the other arene has EWG or not. Furthermore, the interactions between the arenes bearing EDG and EWG are much stronger than those between arenes both bearing EWG. Therefore, charge-transfer interactions are proposed to play a significant role in these systems. Moreover, off-centered lone pair-arene interactions and C-H...O hydrogen bond interactions are also investigated by triptycene-derived systems successfully. The results are consistent with theoretical calculations. Noncovalent interactions have also been studied by computational chemistry. The driving forces in controlling the stereoselection for two allylboration reactions have been explored. For the Roush allylboration, the interactions between the aldehyde carbonyl carbon and the carbonyl oxygen of tartrate ester or amide are f (open full item for complete abstract)

Ph.D., Antioch University, 2025, Antioch New England: Environmental Studies

Adolescents with histories of trauma often experience disruptions to their emotional, social, and behavioral development. For those living in group home settings, supportive environments can play a key role in fostering healing and resilience. While nature interaction is increasingly recognized as a valuable way to support mental health and resilience, little research has explored its role in these settings. This study introduces an innovative methodology—the Interaction Pattern Approach (IPA)—to examine the role of nature interaction in coping and resilience for 12 adolescents with Adverse Childhood Experiences (ACEs) living in a youth group home. In this design, IPA integrates photovoice data with 22 months of participant-observation, employing a structured coding system to analyze meaningful adolescent-nature interactions. The analysis identified 62 distinct Level 3 Interaction Patterns (e.g., “experiencing periodicity of nature,” “seeing wildlife,” “seeking connection with animals”) that characterized how participants engaged with nature. These patterns were grouped into 7 Coping and Resilience Domains (e.g., self-regulation, autonomy, transcendence), each comprising numerous strengths (e.g., emotional regulation, perseverance, gratitude). The findings provide a foundation for developing a “nature language” that emphasizes the ontogenetic and phylogenetic significance of nature interactions. By demonstrating the diverse ways in which nature fosters coping and resilience, this study highlights the importance of prioritizing nature-based interventions in youth group homes and underscores nature's unique potential to support vulnerable populations. This dissertation is available in open access at AURA (https://aura.antioch.edu) and OhioLINK ETD Center (https://etd.ohiolink.edu).

Doctor of Philosophy, The Ohio State University, 2024, EDU Policy and Leadership

This study asked what elements should be included in a cognitive accessibility heuristic framework for parent-educators to compare STEM educational video games for K-5 level autistic children who require substantial supports? To provide an answer to this question, two component questions were asked: 1) “which computer learning game environment and affordance considerations should be included in a cognitive accessibility heuristic framework?” and 2) “which elements of which evidence-based practices should be included in a cognitive accessibility heuristic framework?” A heuristic framework was created that poses questions regarding autism cognitive accessibility considerations for game settings, user interface elements, and user interaction feedback elements that align with evidence-based practices for autism. A small group of 10 participants were parent-educators of autistic children who met the study question criteria and were solicited by convenience and snowball sampling. The heuristic was tested against two STEM-based computer learning games at the K-5 curricular level, specifically Box Island and Peg Plus Cat – Music Maker). Participants were asked to evaluate the heuristic against these games based on how they thought their autistic children would perceive the game experience. Data showed that the list of questions included in the heuristic appropriately considered autism cognitive accessibility when evaluating computer STEM-based computer learning game settings, when reviewing the game environment interface, and when responding to user interaction. The study concluded that participants considered all questions were valuable and should be included. Since the relative importance of some questions differed amongst participants, the heuristic also demonstrated sufficient flexibility to accommodate varying needs of the participants' autistic players. Participants indicated that stepping through the heuristic provided heightened awareness of autistic percept (open full item for complete abstract)

Ph.D., Antioch University, 2024, Leadership and Change

COVID-19 changed how faculty members approached teaching in higher education in the United States. This study specifically looks at the changes in faculty-student interaction (FSI) during the COVID-19 pandemic. While extensive literature exists on the topic from the student perspective, the disruption in education necessitated a more extensive study of the faculty perspective. A multiple-case study methodology was employed to explore the experiences of a small cohort of faculty members at a single institution and how they fostered positive interactions with students from Spring 2019 through Spring 2023. The data collected included semi-structured interviews, course syllabi, teaching philosophies, and a pre-interview questionnaire with demographic data. The findings revealed that faculty initially faced hurdles engaging with students but swiftly devised strategies to adapt. Their approaches primarily emerged from internet searches and conversations with other faculty in their communities of practice. Additionally, faculty members who taught prior to the pandemic used their prior teaching experience but also credited having access to course materials designed for online learning as a strategy for positive interaction. Finally, returning to in-person teaching with social restrictions presented significant challenges in comparison to teaching online. A key implication for practice is requiring faculty to teach asynchronous courses periodically to ensure familiarity with best practices for online learning and access to updated teaching materials. This dissertation is available in open access at AURA (https://aura.antioch.edu) and OhioLINK ETD Center (https://etd.ohiolink.edu).

Doctor of Psychology (Psy.D.), Xavier University, 2023, Psychology

Despite strong evidence for the efficacy of psychodynamic psychotherapy (Drisko & Simmons, 2012; Leichsenring & Steinert, 2019; Shedler, 2010), understanding and articulating the mechanisms that lead to change is a challenge (Pine, 2020). The current study investigated the impact of dynamic/expressive and relational/supportive interventions in response to momentary image-distorting defense mechanisms on immediately subsequent overall defensive functioning (ODF) and patient productivity. A total of 175 Therapeutic Interaction Episodes (TIEs) preceded by a major (borderline) and/or minor (narcissistic) defense mechanism were identified from three consecutive sessions about six weeks into treatment among 25 fully transcribed psychoanalyses completed from 1968 to 2011. Observer rating measures used included the Defense Mechanism Ration Scales (DMRS-5; Perry, 1990), the patient productivity scale from the Analytic Process Scales (APS; Scharf et al., 2010), and items from the Dynamic Interaction Scales (DIS; Waldron et al., 2013b) and APS (Scharf et al., 2010) to identify relational/supportive and dynamic/expressive interventions. It was hypothesized that relational/supportive and dynamic/expressive interventions would contribute to changes in overall defensive functioning and patient productivity. Hierarchical multiple linear regressions were conducted for each outcome variable (ODF and patient productivity) and results did not support the hypotheses. Limitations included small sample size, TIE methodology, difficulty achieving adequate interrater reliability, adapted use of measures, and outcome variable selection. Recommendations for future research employing microanalytic methods of studying psychotherapy processes are provided.

PHD, Kent State University, 2023, College of Arts and Sciences / Department of Chemistry and Biochemistry

Supramolecular Chemistry has become a versatile and dynamic field for drug delivery, catalysis, sensing, and protein targeting. It is based on molecular recognition which is the non-covalent interaction or intermolecular force (IMF) between the host and the guest with high affinity and specificity due to proper fitting. The IMF like H-bonding, Van der Waals forces, electrostatic and/or hydrophobic interaction are considered responsible for the proper fitting on the host cavity, but they lack the direct methods to precisely gauge the assembly/disassembly pathways of noncovalent force due to rapid motions of the molecules. Here, we used single-molecular force spectroscopy to directly measure the intermolecular mechanical force (IMMF) between the different hosts and the guests as well as small molecules. We found that the IMMF of cucurbit[7]uril (CB7) as host and charged adamantane as a guest was greater than neutral adamantane. From this study, we concluded that CB7 is a good host in drug delivery and sensing. However, when we changed the host and guest from CB7 to β-cyclodextrin (Me-β-CD/β-CD) and adamantane to cholesterol, respectively, we found that the IMMF between the β-CD and cholesterol depends on the orientations of the cholesterol inside the host cavity. We also found that the stability of the Me-β-CD-cholesterol complex was greater than the β-CD-cholesterol complex. In addition to the IMMF of host-guest pairs, we also measured the IMMF between two cholesterol molecules which is comparable to the stability of DNA secondary structures and the IMMFs of dimeric cholesterol complexes were dependent on the orientation of the interaction. By looking at the IMMFs, it tells that β-CD can easily solubilize the cholesterol plaque inside the artery. These results demonstrate that the IMMF can serve as a generic and multipurpose variable to examine noncovalent interactions among small molecules.

Doctor of Philosophy (PhD), Wright State University, 2022, Computer Science and Engineering PhD

Inadequate professional training and practices related to health care may result in severe complications to care experiences and outcomes. Moreover, healthcare professionals are as susceptible to the possibility of implicit biases as any other group. Importantly, the health care training is critical and challenging as minor prejudicial beliefs have an adverse influence or serious consequences on patients' health outcomes. Thus, facilitating serious role-playing virtual care practices along with raising awareness of healthcare professionals about the enduring impact of implicit/explicit biases and Social Determinants of Health (SDH) on health outcomes assist to advance the patient-provider relation, care experiences (e.g., healthcare experience and patient care experience), and promote health equity. In addition, employing the “learning by doing” approach for health care practices directly in real-life is less preferred wherein high-risk care is essential. Thus, there is a high scope and demand for the utilization of alternative ways which can facilitate a self-driven and self-motivational digital experiential learning approach with the integration of innovative computer technology that encourages learners to acquire professional development skills. The primary focus of this research is to deliver Computer-Supported Experiential Learning (CSEL) and Computer-Supported Expert-Guided Experiential Learning (CSEGEL) approaches to deliver professional development skills (e.g., healthcare skills). Specifically, this research and development deliver CSEL and CSEGEL approaches-based serious role-playing games or mobile applications as digital experiential learning tools by integrating first-person virtual role-playing scenarios to enhance healthcare skills (e.g., cultural humility, professional communication, awareness of the enduring impact of both social determinants of health and implicit/explicit biases on health outcomes, and compassionate and empathetic attitude) of (open full item for complete abstract)

MDES, University of Cincinnati, 2022, Design, Architecture, Art and Planning: Design

Purpose: This study aims to discover the trust factors between robotaxis and passengers and then propose an in-vehicle interactive design solution that can be referenced in future studies. Design/methodology/approach: The study utilizes data collected from 12 participants using a semi-structured interview. This study's design proposals will be based on interview-based research, literature review, and a case study of modern vehicle cockpit designs. The validation process includes mock-up interaction tests and prototype screen size tests. Findings: According to this study, a reliable robotaxi system should always notify and explain its features to passengers. Meanwhile, passengers should be provided with clear traffic information and control options. The robotaxi should be able to adapt to current and future traffic circumstances while prioritizing journey efficiency. Other findings suggest that passengers may trust the robotaxi more if the vehicle allows them to transfer previous HVI experience to the new environment, particularly if physical buttons are used. Lastly, giving passengers a customized experience through the design of the space would make them more likely to trust the robotaxi. Originality/value: This study examines ways of building trustworthiness between the robotaxi and passengers through an in-vehicle interface system and provides the design guidelines and principles. To reach this goal, the system logic design, the interaction framework, and the user operation hierarchy were all investigated.

Doctor of Philosophy (PhD), Ohio University, 2022, Mechanical and Systems Engineering (Engineering and Technology)

IRF3 dimerization is an important step during the innate immune signal transduction in the human body. However, abnormal dimerization of IRF3 has been linked to a number of diseases, including autoimmune diseases [46], diabetes [35], and cancer [73]. In this dissertation, I focus on understanding the molecular-level processes involved in the dimerization of two interferon regulatory factor 3 (IRF3) proteins. This investigation begins with a fundamental study in which I explore the role of water-mediated interactions in the association of the hydrophobic domains of the protein. I examine the role of hydrophobicity, flexibility, and density of the flexible side chains in systematic simulations using a highly simplified model. Next, I study molecular processes involved in IRF3 protein dimerization. For this study, I first calculate free energy along pathways associated with the association of two IRF3 chains and then determine the most stable dimeric configuration. I extend this investigation to determine how the stable dimeric configuration of IRF3 changes with its phosphorylation state by studying phosphorylation at six different serine residues. This work shows that phosphorylation of different residues of IRF3 protein can significantly change the stable dimeric configuration. Finally, I estimate the protein-ligand binding affinity via Markov state analysis applied to fully atomistic simulations. I apply this technique to study the binding affinities of six different ligands for the ATP binding site of Glycogen synthase kinase-3β (GSK-3β). The binding affinity prediction from Markov state analysis is in strong agreement with the experimental results. My MD simulations show that the ligands that have a higher propensity of attaining a compact conformation due to the stacking of their aromatic groups also show stronger inhibition of GSK-3β activity.

Master of Science (MS), Wright State University, 2022, Computer Science

Promoting awareness of social determinants of health (SDoH) among healthcare providers is important to improve the patient care experience and outcome as it helps providers understand their patients in a better way which can facilitate more efficient and effective communication about health conditions. Healthcare professionals are typically educated about SDoH through lectures, questionaries, or role-play-based approaches; but in today's world, it is becoming increasingly possible to leverage modern technology to create more impactful and accessible tools for SDoH education. Wright LIFE (Lifelike Immersion for Equity) is a simulation-based training tool especially created for this purpose. It is a mobile app that would be available on both Google Play and Apple Store for easy access to the providers. This highly realistic, interactive, and captivating app is essential for creating mindfulness about SDoH and generating long-lasting compassion and empathy in health care workers for their real patients and helping them to build a good clinician-patient relationship. An important aspect of this simulation is the realism of the characters and their behavior. This thesis specifically focuses on the strategy and experience of designing and developing realistic human character models and animations so that the players connect naturally and deeply with the virtual characters. This contributes to the generation of a greater level of empathy in the providers and decreases the level of biases. In addition to its contribution to creating efficient design methodologies, this effort also resulted in a portfolio of high-quality, low-memory multi-modal avatars resembling diverse people of various ethnicities, ages, body types, and gender.

Doctor of Philosophy, University of Toledo, 2021, Psychology - Clinical

Generalized anxiety disorder (GAD), a chronic disorder characterized by excessive and difficult-to-control worry, has been shown to be associated with a global pattern of avoidance, emotion dysregulation, negative affectivity, dysfunctional social cognition, and maladaptive interpersonal behavior. However, limited research exists examining functioning and connection during social interactions. The present study aimed to investigate how individuals with GAD respond while engaged in an intense, online social interaction aimed at increasing level of connectedness. Participants were adult females (N = 101) with and without GAD who engaged in either an evocative or non-evocative/control online interaction. Results revealed that individuals with GAD experienced lower positive affect, higher negative affect, and perceived their interaction partner more negatively (hostile-submissive, hostile, submissive) compared to those without GAD during the interaction. Relatedly, individuals with GAD were perceived more negatively and less positively by their interaction partner during the interaction. However, GAD status did not predict participant likeability, desire to engage in future interaction, intimacy, openness, or commitment to the relationship with their interaction partner. Individuals with GAD further reported experiencing lower levels of connectedness with their interaction partner while engaged in a deep and intimate interaction aimed at fostering connectedness. Results support the notion that the pathology associated with GAD interferes with the ability to engage in prosocial behavior and cultivate close connected relationships. Implications of these findings are discussed.

Doctor of Philosophy, The Ohio State University, 2019, Aero/Astro Engineering

Impinging oblique shockwaves are commonplace in both external and internal flow paths on high-speed vehicles, and their prevalence will only increase with the continued pursuit of readily deployable flight vehicles. These shockwaves cause sharp pressure rises that create intense localized structural loads. Recently, impinging shocks waves have been identified as a mechanism to induce panel flutter, which presents a major concern for fatigue failure and increased noise generation. Critical to this is the fact that loss of panel stability occurs at different operating conditions and panel stiffness compared to classical panel flutter. To date, research on shock-induced panel flutter has been limited to a two-dimensional, semi-infinite assumption. Additionally, most existing simulations on the topic are restricted to inviscid flow. This dissertation documents expanded understanding of shock-induced panel flutter phenomena by exploring the effects of three-dimensionality and viscosity on the aeroelastic system. The analysis is carried out numerically using the Air Force Research Laboratory FDL3DI code. The first configuration considered is Mach 2 inviscid flow over a square panel. The panel is simply supported on all four edges, and the shockwave is set to impinge along the mid-chord. A parametric sweep is performed over non-dimensional dynamic pressure and incident shock angle. Mean, standard deviation, and time history of the panel response are presented. Additionally, the panel response is projected onto the natural mode shapes in order to gain deeper insight into the characteristics of the structural response. Fluid pressure snapshots are also provided. In general, the panel flutter response is qualitatively similar to previous studies on the semi-infinite configuration. Flutter amplitude is slightly lower and flutter frequency slightly higher for the three-dimensional configuration in all cases. Additionally, the critical non-dimensional dynamic pressure is i (open full item for complete abstract)

BFA, Kent State University, 2019, College of Communication and Information / School of Visual Communication Design

This thesis is an exploration in how roleplaying games are designed to fit the needs of potential users. As roleplaying games are experiencing popularity greater than before, it behooves the media to reach as wide an audience as possible, as to not isolate those who might possibly enjoy them. This investigation is done through designing a roleplaying game for an audience of both new players and experienced players. Existing theory questions whether or not a single roleplaying game can be versatile enough to reach the numerous and varied potential audiences, often siding with the opinion that such a game cannot exist. Though research, prototyping, and a cyclical approach to the design process, the author developed a roleplaying game sharing traits of gamist, narrativist, and simulationist creative agendas while maintaining an equilibrium between mechanical complexity and simplicity, enabling use from a myriad of users, regardless of prior experience.

Doctor of Philosophy (PhD), Ohio University, 2018, Physics and Astronomy (Arts and Sciences)

In this dissertation we study magnetic induced effects on semiconducting transition metal dichalcogenides, such as MoS2, WS2, and MoTe2. We model finite size structures, such as flakes, ribbons, and heteroribbons, with a suitable low energy three-orbital tight binding model, which considers the right symmetries at energies close to the band gap. We study magnetic interactions in different systems, such as between magnetic impurities in MoS2 flakes and MoS2-WS2 heteroribbons. Moreover, we consider a MoTe2 ribbon on top of a ferromagnetic insulator substrate to study magnetic exchange effects induced by proximity of the two materials. In the case of magnetic impurity systems, we study two different regimes: the effective exchange interaction between two magnetic impurities embedded in dichalcogenides, and the study of ground state configurations for many magnetic impurities. For the first regime, we study the indirect Ruderman-Kittel-Kasuya-Yosida exchange interaction, which describes how the magnetic impurity spins align with respect to each other. We find sizable non-collinear Dzyaloshinskii-Moriya interactions terms, along the typical Heisenberg and Ising terms. We also find long range interactions (slow decay) when the impurities are set on locations of high wave function probability, such as the flake edges and the interface of the heteroribbons, and at Fermi levels in the gap of the material. In the second regime, the study of multiple magnetic impurities in a spin chain arrangement shows the appearance of low energy ferromagnetic and helical phases, tunable by experimental parameters such as impurity separation and gating. In the hybrid system of MoTe2 on a ferromagnetic substrate, we find spin polarization and spin currents at the MoTe2 edge, driven by Rashba and exchange fields induced by the proximity of the substrate. Our results reveal that the effective magnetic exchange in a TMD finite sample results in strong spin-polarized edge states lying in the 2D b (open full item for complete abstract)

Master of Science (MS), Wright State University, 2018, Biological Sciences

Optineurin, an autophagy adaptor protein genetically linked to Normal Tension Glaucoma and Amyotrophic Lateral Sclerosis, has been found in the pathological inclusions of various other neurodegenerative disorders, supporting an important role of optineurin in neurodegeneration. Using yeast as a model, we found that overexpression of optineurin drastically enhances the toxicity of the Parkinson's disease-causing protein, alpha-synuclein. Considering the conserved protein-protein interaction between optineurin and Ypt1, a yeast suppressor of the toxicity of both optineurin and alpha-synuclein, we hypothesize that cellular targets of optineurin underlie in the cytotoxicity and the enhancer effect. Using genome-wide yeast two-hybrid screens, we identified 97 yeast interacting proteins of optineurin and systematically tested their modifier effect on the toxicity of optineurin and alpha-synuclein. Given the neuroprotective effect of the mammalian homologs of Ypt1, the convergent pathways of the identified modifiers may represent conserved cellular perturbations induced by optineurin overexpression in higher eukaryotes.