Multiscale and Multimodal Structure-Function Analysis of Intervertebral Disc Degeneration and Regeneration

Intervertebral disc (IVD) degeneration and associated back pain place a significant burden on the population. IVD degeneration is a progressive cascade of cellular, compositional and structural changes, which results in a loss of disc height, disorganization of extracellular matrix architecture, herniation of the nucleus pulposus (NP), tears in the annulus fibrosus (AF), and remodeling of the boney and cartilaginous endplates. These changes often occur concomitantly, making it difficult to determine which factor initiates degeneration. Furthermore, assessment of the subcomponents and interfacial regions of the IVD have been largely qualitative to date, and the changes that occur at this length scale with degeneration are not yet well understood. This poor understanding of disease etiology hinders the development of therapies to restore native structure and function of the IVD, and so, current clinical treatments are focused on alleviation of symptoms rather than focused regeneration. As such, tissue engineering provides a promising treatment option and has the potential to restore both the structure and function of the native disc. The overall goal of this thesis is to establish quantitative microscale and macroscale outcomes that define the spectrum of degeneration and to inform regeneration. In Aim 1, we developed a quantitative dataset of the structural and functional features of degeneration over time in an in vivo rabbit model and identified the primary contributors to disc degeneration using a machine learning approach. We found that puncture acutely compromised disc macro and microscale mechanics, followed by progressive AF stiffening and remodeling. These dynamic changes were accompanied by increases in endplate bone volume fraction, increases in microscale stiffness of the soft tissue interfaces between the disc and vertebral bone, and reductions in endplate vascularity and small molecule transport into the disc as a function of degenerative state. Notably, our neural network model identified changes in diffusion into the disc (a measurement of disc nutrition) as the most significant predictor of disc degeneration. In order to extend the translatability of this animal model, we employed similar multimodal analyses in Aim 2, using human cadaveric spines of differing degenerative states. We observed widespread multiscale alterations to the IVD, endplates, bone, and whole motion segment. Interestingly, and in contrast to the rabbit model, we observed motion segment softening and endplate resorption with degeneration. We discerned several correlations between the quantitative variables, particularly between IVD and endplate measurements, suggesting crosstalk between these tissues during degeneration. To address a potential treatment strategy for end-stage degeneration, we sought to advance and optimize the composition and mechanics of a tissue-engineered whole disc replacement (DAPS). Our findings from Aims 1 & 2 indicated that AF structural integrity and micromechanical properties are severely affected during degeneration, and as such, in Aim 3, we included a soluble polymer into the AF region of the DAPS to promote cell ingress and improve matrix distribution. This modification better approximated native micro- and macro-mechanical properties of the DAPS, cellular colonization, and matrix elaboration, in the in vitro and vivo environments. Overall, the results from this Thesis identify the most significant contributors to disc degeneration, and advance new treatment strategies towards clinical use.Ph.D., Biomedical Engineering -- Drexel University, 202

Electrochemical and Rheological Analysis of Flowable Conducting Suspension Electrodes for Scalable Energy Storage

Following the advancements in materials development for electrochemical systems, flowable suspension-type (i.e. semi-solid) electrodes have gained much attraction in the last decade, offering scalability and flexible design for many conventional energy storage technologies. Flowable suspension electrodes are multi-phase mixtures of liquid electrolytes and electrochemically active solid particles that can offer fluidization of traditional electrode chemistries and allow adaptation of highly scalable flow-assisted system architectures for large-scale energy storage applications. In suspension electrodes, volume spanning networks of conducting particle clusters facilitate the transport of charges under dynamically changing conditions and the liquid electrolyte phase is responsible for the physical transport of ions and the solid particles. Due to their complex nature, experimental and theoretical approaches are required from a host of disciplines to fully investigate the governing properties of suspension electrodes. Despite its significance, optimizing the electrochemical and rheological parameters not only for efficient electrochemical performance but also for low-dissipation flow remains to be one of the least explored areas. This thesis aims to address the existing gap in rheological understanding of capacitive suspensions in relation to their electrochemical performance and focuses on establishing key structure-property relationships that can ultimately help us achieve low-dissipation flow, high electrochemical performance capacitive flowable systems. This is accomplished through systematic experimentation to establish a link between key rheological properties and the electrochemical performance. Multi-component carbon suspensions consisting of high-surface-area porous carbons and conducting carbon nanoparticles are used as model systems to investigate the effect of particle morphology on charge percolation and rheological behavior of flowable suspension electrodes. A systematic study focusing on different types of slurry preparation protocols is carried out to determine the impact of mixing on electrical conductivity and electrochemical performance of capacitive suspensions. Alternative electroactive materials with hydrophilic surface groups such as MXenes are explored, investigating the potential of clay-like conducting particles for low-dissipation flow FE applications. Lastly, focusing on minimizing rheology dependent losses (e.g. pumping) and improving the power output of low-viscosity suspensions, the emphasis is given to alternative approaches to flow cell design and an overview of porous electrode integration to slurry electrode systems is provided.Ph.D., Materials Science and Engineering -- Drexel University, 202

Executive Function Professional Development: A Curriculum Review

This study explored to what extent teacher professional development on executive functions, a student's cognitive ability to regulate academic behavior (Dawson & Guare, 2010), is meeting the needs of teachers as adult learners. Primary and elementary school teachers are continually engaged in professional development to refine and advance their craft. The purpose of this instrumental case study was to explore the extent to which a school district's professional development on executive functions is providing teachers with the knowledge they need to support students' growth of execution functions and meeting the teachers' needs as an adult learner. The researcher investigated the design of an existing executive function professional development curriculum and reviewed teacher perception of the impact of the training on their understanding and practice. The study was guided by the following research questions: 1. How do teachers in a rural K-12 school district located in the northeastern United States perceive the impact of the existing curriculum on their understanding of executive functions and their classroom practices? 2. To what extent does the existing curriculum reflect current research in executive functions and brain development? 3. To what extent does the existing curriculum utilize elements of effective teacher professional development and adult learning? Conceptually the researcher framed the literature review around three topics: research on executive functions, adult learning theory, and teacher professional development. The researcher obtained the existing executive function curriculum used by the school district and conducted a review. Primary and elementary school teachers from the selected district were asked to participate in a Qualtrics survey to collect qualitative data about the perceived impact of the curriculum on their understanding of executive functions and their classroom practices. Based upon the data collected, analyzed, and interpreted, recommendations were made regarding the use of the existing executive function professional development curriculum to enhance skill development in students.Ed.D., Educational Leadership and Management -- Drexel University, 202

An Examination of the Relationship Between Parents' Attitudes and Actions Pertaining to Mathematics and Their First-Grade Private School Children's Attitudes Towards Mathematics

Children should begin to learn foundational mathematical concepts at a developmentally appropriate level at home when they are young, just as they learn the building blocks of reading when involved in daily activities. Parents of young children should understand the importance of introducing these concepts to their children in fun, natural ways so they do not miss the opportunity to facilitate the building of a strong mathematical foundation in their children. In addition to understanding the importance of math-related experiences parents provide their young children, it is essential to understand how parents' attitudes towards math may inadvertently predispose their children to think negatively about math, potentially impacting the children's attitude towards math throughout their school career. As young children are influenced by both affective and tangible experiences with parents in their homes, the purpose of this study was to explore the possible influence of parental attitudes about math and the math-related experiences they provide on the attitudes towards math of their non first born, first-grade private school children. This qualitative case study used individual interviews of the parents, specifically the mothers, and their first-grade private school children and an observation of the mothers and children baking cookies together to gather data which were then analyzed using a five step process to answer the research questions: Is there a relationship between parents' attitudes about math and the attitudes about math of their first-grade children enrolled in private schools? and How do parents' actions influence the attitudes about math of their first-grade children enrolled in private schools? Study findings indicate that there is a positive relationship between the children's attitude towards math and what they perceive their mother's attitude towards math to be. However, there was no evidence that using math in their everyday lives led to a positive attitude towards math in the children primarily because study participants were unaware of the foundational math concepts embedded in their daily activities. Recommendations include teaching parents about basic foundational math concepts and how they can be included in engaging real life activities and how making a purposeful connection between the activity and math concept(s) involved can bridge the home-school math experiences leading to a more cohesive math education.Ed.D., Educational Leadership and Management -- Drexel University, 202

A Quantitative, Cross-Sectional Study: Investigating Staff Morale of Early Intervention Teachers in Eastern and Southeastern Pennsylvania Intermediate Units

This quantitative, cross-sectional study investigated the current state of staff morale within early childhood special education (ECSE) environments in four Eastern and Southeastern Pennsylvania intermediate units. The problem addressed by this research is that staff in ECSE may be at risk for low morale, impacting work environments for teachers who support quality services for students. Given the lack of research into ECSE morale, this study aimed to address this knowledge gap within the literature by discovering how satisfied teachers in early intervention settings are within their work environments. Research has shown that many factors contribute to a state of morale and that morale can be measured through job satisfaction. Maintaining a positive working environment, in addition to job satisfaction, has a positive correlation with the quality of work produced and teacher morale. By administering the Early Childhood Special Education Job Attitude Survey (ECSEJAS), this study examined perceptions of staff morale and factors that affect morale among 56 ECSE teachers and 14 Early Intervention (EI) program administrators. Survey results were compared between teachers and administrators, regions, and locations. Findings indicate that there was not a statistically significant difference between the state of morale by location or region. However, there was a statistically significant difference between ECSE teachers and EI program administrators; with ECSE teachers having a lower morale score (EI program administrators: M=95.93, ECSE teachers: M=77.45). Primary factors affecting morale, that have the capacity to be controlled or altered at the organizational level, were found to be workload, compensation, the ability to be involved in decision-making, and professional development. This study advances research in EI by providing a much-needed baseline of staff morale within ECSE environments that can be used in future research. Based on the study results, recommendations for practice include capping workloads, increasing professional development, providing fair compensation, and increasing staff empowerment in decision-making. Recommendations for future research include exploring the potential cause for the statistically significant difference found between EI program administrator's and ECSE teacher's morale and expanding the investigation of primary factors affecting morale of early intervention staff across additional intermediate units in the state of Pennsylvania.Ed.D., Educational Leadership and Management -- Drexel University, 202

Using Raymarched shaders as environments in 3D video games

Today’s 3D video games boast of massive game worlds. Responsible for this are a huge group of 3D artists who bring the world to life through their content creation skills. But what if the entire world could be created and rendered with the help of a single shader. The video game industry has almost solely relied on poly modeling as its main source of content creation. But technical and usability issues with the use of polygons exist to this very day, such as the need for a high polygon counts to depict detail, tedious setup of the environment, the use of multiple levels of detail for individual assets, repeated asset instantiation to depict endless environments, and lack of flexibility in changing entire environments due to memory and storage overhead. In order to overcome these issues, alternate means of content creation need to be considered and evaluated. The idea of creating endless video game terrains and assets without the use of the traditional asset generation pipeline and repetition of art assets is a fascinating and favorable one for video game artists, and has found limited application through procedural generation of geometry (polygons). This research aims at achieving the above in a game engine with just the use of shader code. Shaders have long been used to tweak surface and material properties of poly surfaces in the video game industry, but have seldom been looked at as a means of asset creation just by themselves. Raymarching is the technique that makes the rendering of environments solely with the use of a shader possible. It has existed for decades but has only recently found popularity in real-time applications due to the expansion of hardware shaders. Our research is aimed at defining a content creation pipeline which supports rendering game environments in game engines solely with the help of shaders, and evaluating its potential use for interactive game environments. To facilitate this, we will compare the shader generated environments with a similar poly-modeled environment using the key factors of content generation as a framework to analyze them in a qualitative and quantitative manner.M.S., Digital Media -- Drexel University, 202

Broken Chains: Non Traditional Black Male Experiences in The College Admissions Process; A Study in Portraiture

This qualitative study used portraiture as a research method to highlight and understand the lived experiences of three Black-male non-traditional aged learners during the college admissions application process. The study also sought to answer what are the issues and complexities facing Black male non-traditional learners during the college admissions process? Specifically, this study surfaced true experiences of non-traditional aged Black males engaged in the college admissions process for the first time. Portraiture operates in qualitative paradigms that links science to art merging the methodical and thorough depiction of excellent ethnography with the suggestive character of good writing. Much of the research around the college admission process for Black men is historical with attention on the overarching impact of historical court decisions, diminished school resources, and ethical college admission practices to increase access for traditionally aged minority students, but very little research exists on how Black non-traditional male learners make meaning of their college application experiences, or the spaces where their stories are being told. I captured some of those stories in this dissertation.Ed.D., Educational Leadership and Management -- Drexel University, 202

Level of Fit of Two Fracture Fixation Plates to the Radius through Physical and Virtual Analysis

Fractures of the radius are commonly treated by open reduction and internal fixation by use of a fracture fixation plate. In doing so, the gap between the underside of the plate and the surface of the bone must be minimized, and contouring time of the plate to the radius shape must also be minimized. It is proposed that plates with an initial precontour to approximate the shape of the radius will best achieve these requirements. To this end, the goal of this study is to evaluate the bending time and the level of fit of precontoured plates versus standard plates in fracture fixation of the radius. Six cadaver arms were obtained, and their radii were extracted and cleaned of soft tissue. Precontoured plates designed by Acumed, LLC, were fitted to the radii before and after additional contouring along with standard industry plates designed by DePuy Synthes. Gap measurements were taken at various points along the plate, and bending times were recorded for the plates that were additionally contoured. This analysis was then repeated virtually as well as physically through use of 3D printed duplicates of the radii. The dorsal precontoured Acumed and Synthes plates were found to fit equally well to the radius, while the volar precontoured Acumed plate does not fit as well as the Synthes plate. Additionally bending both the dorsal and volar Acumed plates provides superior fit over the Synthes plate. Also, no significant differences were found between the measurements of the bone and 3D printed bone, meaning 3D printed bone could be a useful facsimile of real bone for use in surgical planning.M.S., Mechanical Engineering and Mechanics -- Drexel University, 202

A Phenomenological Study: Exploring High School Students' Experiences Earning an Entrepreneurship Diploma in an Entrepreneurship Education Secondary School Program

As of 2015, 42 states reported some type of entrepreneurship education standards, guidelines, or proficiencies and 18 states required entrepreneurship education courses to be offered at the high school level. Yet, there is limited qualitative literature on students' experiences in degree-granting entrepreneurship education secondary school programs that promote an entrepreneurial mindset. This leads to a limited understanding for secondary school leaders and curricula developers designing and implementing these programs, which potentially results in the design and implementation of ineffective programs. The purpose of this qualitative, phenomenological study was to explore high school students' lived experiences earning a high school Entrepreneurship Diploma (ED) that was designed to promote an entrepreneurial mindset. This study collected and analyzed qualitative data from ED Cohort 1 members, their parents, and former program faculty, primarily through questionnaires, interviews, and reflection matrices. Four results emerged from the study's findings: (a) Uncertain and Non-Traditional Future Work Landscape Necessitates Diverse and Holistic Skillset, which the ED Promoted; (b) Participation in Numerous and Reoccurring Experiences that Enable High School Students to Apply Classroom Learning to Real World Problem-Solving and Presentation Empowers Students to Develop Confidence and Take Risks; (c) Sustained Collaborative and Teamwork-Based Learning Leverages Social Relationships and Helps Students Develop and Understand the Value of Support Networks; and (d) Self-Reflection and Feedback in the Context of Entrepreneurial Mindset Development Enable Powerful and Purposeful Self-Discovery of Authentic Identity. These results are valuable to secondary school leaders and curricula developers designing and implementing entrepreneurship education programs that promote an entrepreneurial mindset in students. Since these results also indicate the skills with which high school students might be entering college or the workforce, these results are indirectly valuable to college administrators and employers, who desire entrepreneurially minded individuals or employees.Ed.D., Educational Leadership and Management -- Drexel University, 202

Exploring the Lived Experiences of Servant Leaders who Model Altruism to Motivate Young Adult Protégés for Altruistic Service in a Nonprofit Humanitarian Organization: A Phenomenological Study

This study explored the lived experiences of altruistic servant leaders who practice selfless service; it sought to understand how servant leadership and altruism shape and transform young adult protégés to become emerging leaders who embrace altruistic service as a calling. This research focused on the difficulty that the humanitarian segment of the nonprofits sector is facing in attracting, recruiting, and retaining young adults who are altruistic as part of their workforce. A phenomenological approach was used to identify and understand the psychological essences, pattern, and structure of the lived experiences of the study participants. Semi-structured interview questions were developed to explore the individual participant's deep and lived meaning of altruistic love and captured the thick and rich description of the issues explored. Three distinct results, which were the major themes that emerged from the study, were significant ideas that synthesized findings and were congruous to the concept and purpose of this study: (a) providing leadership for protégés, (b) mentoring protégés for transformation, and (c) facilitating learning experiences for protégés. The results from this study informed the recommendations for leader-mentors to possess altruistic love as a virtue and demonstrate selflessness in serving others as a lifestyle. It is also recommended for them to deploy the strategy of need-based selfless service to protégés for the building of mutual trust, then making the protégés have a sense of belonging by allowing them to be involved as partners in their own mentoring and development program. Furthermore, the engagement of protégés in ongoing dialogue that can shift their meaning perspectives is recommended. Creating the opportunities for protégés to be involved in community service that will facilitate learning experiences, self-reflection, and self-discovery, which will enable them to connect with altruistic service as a calling is part of the recommendations. Therefore, this study provided some potential solutions for solving the research problems.Ed.D., Educational Leadership and Management -- Drexel University, 202