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Beyond the Mission: Understanding Belonging in Concorde’s Division
No full textLeadership and Learning in Organizations capstone projectConcorde’s Commercial Rocket Launch Division, also known as Nighthawk, is responsible for licensing and regulating commercial space activities to ensure safety and compliance with federal standards. Nighthawk is critical in regulating, licensing, and commercial space activities. Within Nighthawk, the Nexus division handles business operations, policy, and innovation and supports Nighthawk’s licensing and regulatory processes. As the commercial space industry expands, Nighthawk faces increasing complexity in its regulatory responsibilities. Employees, particularly in Nexus, report a diminished sense of belonging and misalignment with the organization’s mission to provide the safest, most efficient aerospace system in the world.
This study investigates:
1. How do employees' perceptions of their roles and responsibilities within Concorde’s commercial rocket launch division correlate with their sense of belonging to the organization?
2. What organizational factors significantly influence employees’ sense of belonging within the Concorde’s commercial rocket launch division?
3. What specific organizational strategies or practices can the Concorde’s commercial rocket launch division implement to strengthen employees’ sense of belonging?
This mixed-methods approach utilized survey data, leadership interviews, and insights from a strategic off-site to assess perceptions, organizational structures, and communication practices across the division.Findings revealed a significant disconnect between employees and the organization’s mission, particularly within the Nexus division pointing to low levels of engagement, unclear role alignment, disconnect from the mission, and a lack of belonging within the workforce. Additional challenges include high workloads without clear staffing plans, weak communication from leadership, and low engagement metrics—only 29% of employees felt their talents were fully utilized. External scrutiny and rigid regulatory constraints compound internal frustrations, further weakening employee connection to the organization.
To address these issues, the study recommends four strategic actions:
(1) strengthen leadership communication to align daily work with mission objectives
(2) improve workforce development through structured engagement and talent utilization programs
(3) foster a culture of inclusion and recognition to increase organizational belonging
(4) streamline operational processes by involving employees in efficiency initiatives.
These recommendations aim to build a more connected, supported, and mission-driven workforce as Nighthawk continues to grow and are designed to cultivate a more engaged, resilient, and high-performing workforce capable of navigating the complexities and opportunities presented by the dynamic landscape of commercial space exploration
Deep Learning Enabled Methods for Information Hiding
No full textWhen you look at the provided image, what do you see? Two gorgeous fur babies? Funny looking life jackets? To the unassuming eye, this image is exactly as it appears---two gorgeous dogs in life jackets---but beneath the surface, this image contains the entire work of Shakespeare's "Hamlet", embedded in a manner to be imperceptible to the human eye. Information hiding is a method of secure communication through strategic concealment and extraction. It enables communication while completely disguising the act itself. Because information hiding techniques are deeply intertwined with evolving technologies, they advance as rapidly as new innovations emerge. As methods for embedding hidden data become more sophisticated, so too do the techniques for detecting and eliminating them, creating an ongoing cycle of adaptation and countermeasures.
This dissertation examines information hiding through the lens of deep learning, exploring topics such as deep learning-based sanitization techniques for removing hidden information from media, automated methods for visible watermark removal, trigger-based fragile watermarking schemes for safeguarding model integrity, and an analysis of the robustness of modern malware detection models
The Effect of Error Correction Procedures on Skill Acquisition and Maintenance: A Component Analysis of Prompt-Transfer-Distract-Check (PTDC)
No full textWhile certain error correction procedures are well-supported by existing research, others - such as the Prompt-Transfer-Distract-Check (PTDC) procedure - require further investigation to determine the conditions under which they are most effective. This study conducted a component analysis of PTDC to examine its effects on skill acquisition, maintenance, and participant preference relative to a prompt-transfer only (PT-only) condition. An adapted alternating treatments design was used to compare the two procedures across three preschool-aged children during discrete trial training (DTT) targeting novel tacts. Dependent variables included percentage of correct responses, various efficiency measures, and maintenance performance. All participants acquired skills in both conditions, with PT-only demonstrating slightly greater instructional efficiency for two participants. However, these differences were minimal and may be even less pronounced under typical instructional conditions that include antecedent instruction. Preference for PTDC may have been influenced by variability inherent in the procedure, suggesting that variability itself could function as a reinforcer and potentially influence preference. Limitations related to target set equivalency are also discussed
Understanding the Effects of DRP1 Patient Mutations on Synaptic Maturation of Cortical Neurons
No full textWith the advent of exome sequencing, a growing number of children are being identified with de novo loss of function mutations in the dynamin 1 like (DNM1L) gene encoding the large GTPase essential for mitochondrial fission, dynamin-related protein 1 (DRP1); these mutations result in severe neurodevelopmental phenotypes, such as developmental delay, optic atrophy, and epileptic encephalopathies. Though it is established that mitochondrial fission is an essential precursor to the rapidly changing metabolic needs of the developing cortex, it is not understood how identified mutations in different domains of DRP1 uniquely disrupt cortical development and synaptic maturation. We leveraged the power of induced pluripotent stem cells (iPSCs) harboring DRP1 mutations in either the GTPase or stalk domains to model early stages of cortical development in vitro. High-resolution time-lapse imaging of axonal transport in mutant DRP1 cortical neurons reveals mutation-specific changes in mitochondrial motility of severely hyperfused mitochondrial structures. Transcriptional profiling of mutant DRP1 cortical neurons during maturation also implicates mutation-dependent alterations in synaptic development and calcium regulation gene expression. Disruptions in calcium dynamics were confirmed using live functional recordings of 100 DIV (days in vitro) mutant DRP1 cortical neurons. These findings and deficits in pre- and post-synaptic marker colocalization using super resolution microscopy, strongly suggest that altered mitochondrial morphology of DRP1 mutant neurons leads to pathogenic dysregulation of synaptic development and activity
The Role of the Cationic Amino Acid Transporter SLC7A2 and Arginine on Pancreatic Alpha Cell Proliferation and Function
No full textInadequate secretion of insulin from pancreatic β-cells in concert with failure to suppress pancreatic α-cell secretion of glucagon results in hyperglycemia and ultimately diabetes. However, the mechanisms for this inappropriate secretory response of α- and β-cells during diabetes has not been fully determined. Although much is known about glucose regulation of islet hormone secretion, how amino acids, such as arginine, have been understudied in hormone secretion and glycemic regulation. Our lab and others have identified a liver-α-cell axis that mediates the regulation of α-cell function through changes in circulating amino acids. Arginine is a potent stimulator of insulin and glucagon secretion, suggest that α-cells and β-cells might have robust arginine transport and sensing capacity. This dissertation aims to elucidate the mechanisms by which arginine stimulates islet hormone secretion and cell proliferation using global and islet cell type specific alterations in expression of the cationic amino acid transporter, SLC7A2, including a surprising role for arginine sensing and α-> β cell communication
Amplifying Student Voice: How Connectedness and Academic Engagement Shape Key Student Outcomes at an Urban Middle School
No full textLeadership and Learning in Organizations capstone projectSummit View Middle School (SVMS), a highly diverse, urban public middle school, experienced a decline in student outcomes following the COVID-19 pandemic, including chronic absenteeism, behavioral disruptions, and low academic performance. To address these issues, the school implemented the Student Voice Program (SVP)—a student-led, project-based intervention aimed at increasing school connectedness, engagement, and academic motivation. This study examined the relationships between students’ perceptions of connectedness and academic engagement and school outcomes, and the impact of the SVP on students’ beliefs, behaviors, and performance at SVMS.
The questions guiding this project were:
Q1: What is the relationship between students’ perceptions of connectedness and academic engagement and school outcomes (achievement, behavior, and attendance)?
Q2: How do SVP participants and educators perceive the program’s impact on connectedness, engagement, and students’ ability to meet school expectations?
Through a multi-phase mixed-methods design and case study, several key findings emerged, including:
Academic engagement and self-efficacy are the strongest predictors of GPA and attendance.
School connectedness, when paired with high engagement, supports better attendance.
Engagement significantly predicted GPA (β = .21), while connectedness alone did not.
Students in the SVP demonstrated ownership of learning, accountability, and participation. Educators observed SVP as a catalyst for transforming student identity, building leadership, and improving relationships.
Findings allowed us to make three key recommendations to SVMS to increase student self-efficacy, scale the SVP, and redefine academic rigor.
This study underscores the power of authentic student voice and academic engagement as levers for transforming school climate
Synthesis and Characterization of Two-Dimensional Materials
No full textSince the isolation and discovery of the electronic properties of graphene in 2004, two-dimensional (2D) materials have emerged as a new class of materials that can enable next-generation applications. Hexagonal boron nitride (h-BN), has the potential to make transformative advances in ultra-high permeance, size selective membranes for applications such as hydrocarbon separations, proton exchange membranes, and even hydrogen isotope separations, however the generation of nanometer scale pores in the material remains a challenge due to h-BN’s ceramic material properties. In this dissertation, a thorough literature analysis is performed on all existing methods to synthesize h-BN, ranging from flux-based synthesis of high-quality bulk h-BN, analogous to graphite, to the synthesis of monolayer and few-layered films. Monolayer h-BN synthesis via chemical vapor deposition (CVD) on copper is explored as route to make atomically-thin membranes with ceramic properties, useful for separations in harsh thermal and chemical environments. Size-selective membrane performance is found to vary with the CVD growth temperature, offering a bottom-up method to integrate nanopores in the material. The mechanism of h-BN synthesis on iron is then investigated, where the co-solubility of boron and nitrogen into the catalyst foil significantly alters reaction kinetics. Insights into the unique reaction mechanism are presented. Using machine-learning, an ideal parameter space for growing monolayer h-BN is identified. The separation of hydrogen isotopes is then demonstrated on CVD-grown h-BN, and we find that h-BN grown on iron allows for comparable separation performance as pristine exfoliated h-BN, whereas h-BN synthesized on Cu exhibits significantly less selectivity due to intrinsic nanopores in the material. Membrane-based defect characterization is also performed on monolayer MoS2, enabling centimeter-scale analysis of sub-nm to nanometer vacancy defects in the material. The bottom-up generation of carbon defects in the h-BN lattice is demonstrated during the CVD process, ultimately useful as another method of pore creation, or intentional carbon doping towards generating single-photon emitters. Finally, a novel and scalable synthesis process is demonstrated to grow flux-quality h-BN on a planer substrate with deterministic thickness control, circumventing the challenges associated with flake exfoliation methods
Beyond the Racial Discipline Gap: The Collateral Consequences of School Suspension among African American and Afro-Caribbean Adolescents
No full textAn extensive body of research documents racial disparities in exclusionary school discipline between Black and White students, demonstrating the persistence of racial inequality in US public schools. Education scholars find that exclusionary discipline poses collateral consequences for affected youth, including Black adolescents. However, few studies consider how school punishment affects Black youth of diverse ethnicities. Consequently, I examine the impact of school suspension on selected health and educational outcomes among African American and Afro-Caribbean adolescents. Drawing on perspectives in the sociology of race, ethnicity, immigration, education, and health, I use data from the adolescent supplement of the National Survey of American Life (2001-2003) to test these relationships. Study one examines the association between school suspension and depressive symptoms among African American and Afro-Caribbean adolescents and the mechanisms underlying these relationships. Findings reveal that suspension is associated with higher depressive symptoms in each group. Among African Americans, this relationship is partially explained by family emotional support and mastery. Study two examines the impact of school suspension on self-reported grades and homework time among the same groups. Results indicate that suspension is linked with lower grades among African Americans and Afro-Caribbeans. Moderation analyses show that suspension has a more detrimental impact on the average grades of African Americans compared to their Afro-Caribbean peers with similar achievement. Relative to high-performing African Americans, school suspension is more damaging to the high achievement of Afro-Caribbeans, suggesting that it may be one path through which the Afro-Caribbean educational advantage declines. Findings also reveal that suspension is related to reduced homework time in the combined sample of Black adolescents, and this relationship does not vary by ethnicity. The final study investigates the impact of school suspension on tobacco smoking among African American and Afro-Caribbean adolescents. Results show that suspension influences smoking in the combined sample, and this relationship does not differ by ethnicity. In sum, my dissertation extends research on exclusionary discipline by uncovering ethnic variation in the relationship between school suspension and multiple outcomes among diverse Black adolescents
Regulation of β-catenin Localization in Wnt Signaling
No full textThe transcriptional coactivator β-catenin is a critical effector of the Wnt pathway. Initially identified as a key component of the cadherin complex, β-catenin also plays an essential role in cell-cell adhesion at the membrane. Whether Wnt-regulated cytoplasmic β-catenin interacts with the cadherin-associated pool under physiological conditions is unclear. Using a mutant cell line depleted of N- and E-cadherins, I demonstrate that the mutant cells exhibit lower levels of basal -catenin that plateaus to a similar level as the parental line with Wnt3a stimulation. Furthermore, the cadherin mutant line exhibits significantly enhanced levels of Wnt signaling by comparison to its parental control; these effects are reversed by reintroducing wild-type E-cadherin but not a form that cannot bind-catenin. Enhanced Wnt signaling in the cadherin mutant is consistent with a previous study showing that Wnt pathway activation occurs via fold changes in β-catenin levels. Our mathematical modeling suggests a mechanism in which β-catenin binding to cadherins acts as a sink to maintain elevated cytoplasmic -catenin levels in the face of -catenin destruction complex activity. To explore disease implications, our bioinformatic analysis reveals a correlation between elevated Wnt target gene expression and the loss of E-cadherin in a Wnt-driven model of thyroid cancer. Our results have relevance for tumorigenesis, as cadherin loss is commonly associated with poor prognosis and increased metastatic potential
Manipulating Local Atomic Environment on Solid Surfaces for Catalysis: From Single Atoms to Clusters and High-Entropy Oxides
No full textUnderstanding and engineering local atomic environment of an active site is critical for optimizing catalytic performance. This dissertation investigates how electronic structure, atomic ensembles, lattice strain, and compositional effects influence catalysis at the atomic scale. Using density functional theory (DFT) and machine learning, several catalytic systems are explored. First, Pt single atoms on Gd-doped CeO₂ are shown to enhance CO oxidation due to a new reaction channel opened from the interaction of the Pt single atom with the oxygen vacancy induced by Gd-doping and the CO reactant. Second, Pd dimers on CeO₂ surfaces are optimized for methane combustion through precise control of the Pd–Pd distance on the surface and in the oxygen lattice of CeO2. Third, a PdO trimer on CeO₂ enables efficient CO₂ hydrogenation and C–C coupling, leading valuable C₂ products. Finally, the complex local environment on the surfaces of a medium-entropy oxide is investigated for methane activation using hydrogen adsorption energy (HAE) as a descriptor, revealing key local factors governing adsorption energies; state-of-the-art graph neural network models are compared and DimeNet++ is shown to provide strong predictive performance and transferability for HAEs. Together, these studies provide atomic-level insights into how local environment can be manipulated to design more efficient catalysts for energy and environmental applications