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THE DIETARY EVOLUTION AND REGENERATION PHYSIOLOGY OF FRESHWATER ANNELIDS
No full textAll organisms must acquire materials to build their bodies and generate energy to fuel essential functions. Animals are especially reliant on the consumption of organic matter, ranging from detritus to other animals, to fuel processes that build, maintain, repair, and replicate their bodies. Without the ingestion, absorption, and metabolism of nutrients, most organismal functions are impossible. To understand organismal function and adaptation, it is important to understand how organisms acquire and use resources. In this dissertation, I investigated both how new diets evolve and the physiological mechanisms that power regeneration, using a family of meiofaunal annelids as models. In the first part of my thesis, I explored dietary evolution by investigating how carnivory evolved in an unusually predatory annelid genus. Recent transitions to carnivory are rare among animals, limiting our understanding of how and why non-carnivorous lineages become predatory. In my first two chapters, I employed a molecular phylogeny and metabarcoding gut content analysis to demonstrate that carnivory evolved twice in the genus, likely mediated by intermediate diets of ciliates and by mollusc symbiosis. These data suggest thatcarnivory can evolve from non-carnivorous ancestors through distinct evolutionary pathways, even among closely related lineages. In the second part of my thesis, I explored the metabolic pathways that fuel regeneration. Much is known about the developmental mechanisms that initiate and shape regeneration, but relatively little research has explored the physiological mechanisms that fuel regeneration. For my third chapter, I employed comparative respirometry, qPCR, and pharmacological experiments to demonstrate that anaerobic metabolism, but not aerobic metabolism, is required to fuel regeneration in annelids. These data add to accumulating evidence that regeneration, cancer, and development are regulated by similar metabolic mechanisms. I expand on regeneration physiology for my fourth and final chapter, where I synthesize literature exploring the significance of nutrition, metabolism, and the environment to regeneration across invertebrates. Ultimately, my investigations of dietary evolution and regeneration physiology deepen our understanding of the ways that animals obtain energy and allocate it to essential functions
DESIGN’S ROLE IN THE REPRESENTATION OF COMMUNITIES OF PEOPLE OF COLOR ON STAGE
No full textThe following thesis reflects on the importance of authentic representation of communities of people of color using scenic design. It outlines the scenic design process of two shows as case studies, A Bicycle Country by Nilo Cruz and for colored girls who have considered suicide / when the rainbow is enuf by Ntozake Shange, produced by the School of Theatre, Dance and Performance Studies at the University of Maryland, College Park in November of 2023 and February of 2025 respectively. Tools used to convey the design to the creative and production teams include research images, concept renderings, ¼” scale model photographs, drafting plates, and paint elevations. Additionally, this paper includes process and production photographs and a reflection of the entire process
Afterlives of Black Fugitive Resistance: Narratives of Colorism, Framing Blackness, and Gender in Runaway Advertisements
No full textTo understand the foundations of Black life in the United States, it is necessary to confront the legacy of slavery. The enduring structural and racial impact of slavery and global colonialism in shaping contemporary society is at the core of my dissertation work. I employ innovative hand-coded data detailing runaway enslaved persons during colonial-era U.S. slavery as a vehicle to drive empirical and theoretical conversations about the connections between historical and contemporary processes of race, racialization, and intersectional Black identities. To this end, I work through three primary projects.In Manuscript 1 (Chapter 2), I explore processes of “color-coding” enslaved Black individuals through the establishment, standardization, and transmission of color-based terminology (e.g., “light,” “brown,” or “dark”). To detail these historical nuances of color, I conduct a scoping review of over 6,000 hand-coded runaway advertisements and advance historical documentation of the color terminology employed during U.S. slavery. My review provides evidence of an enduring transmission of color vocabulary from the era of U.S. slavery to shaping contemporary labels of skin, as well as suggesting the inheritance of color terminology across racial groups (i.e., from white enslavers to the Black community).
Manuscript 2 (Chapter 3) challenges hegemonic bi-dimensional skin-color frameworks and suggests that processes used to label skin tones are inconsistent across the color spectrum. Through this chapter, I delve into a quantitative analysis of the relationship between perceived skin tone and the prices offered as rewards for the recapture of runaway individuals. My findings support historical and social science expectations that functions of colorism operate across a sliding gradient dependent on skin shade (i.e., significantly higher rewards offered for the recapture of lighter-skinned men). However, drawing from Black scholars’ discussions on hegemonic normativity, I argue that the absence of descriptors for medium-skin tones reflects a distinct form of “othering,” wherein existing cultural and social frames define and value identities in relation to historically white-centric standards.
Manuscript 3 (Chapter 4) employs a mixed-methods approach to examine the intersection of gender and race. Employing an intersectional lens, my quantitative findings reveal that, relative to men, higher proportions of enslaved women ran away in groups. Further, the composition of these groups had higher odds of including children when women fled, highlighting the strong influence of gendered expectations shaping opportunities for resistance. My qualitative findings document the erasure of the agency of runaway enslaved women through enslavers’ frequent portrayal of runaway women as extensions of resistance efforts led by men (e.g., claiming that runaway women were “enticed away”). These findings challenge existing narratives by showing that Black women’s resistance is systematically minimized. This pattern parallels contemporary political debates about the visibility of Black women’s leadership and agency across resistance efforts
SOCIAL-EMOTIONAL LEARNING IN ELEMENTARY SCHOOL: BUILDING CONSENSUS AMONG KINDERGARTEN TEACHERS
No full textElementary school educators are responsible for supporting the development of the whole child, which includes both academic instruction in subjects such as reading, writing, and math, and supporting the development of social-emotional learning (SEL) skills. Research from the Committee on Academic, Social, and Emotional Learning (2008b) links SEL instruction to positive student outcomes, including increased academic motivation, improved cognitive test performance, and enhanced self-control as reported by teachers. Hawkins et al. (2008) found that students with greater social-emotional competence are more likely to graduate from high school and be college and career ready. Additionally, CEOs from leading U.S. companies have reported that individuals entering the workforce often lack basic employability skills such as the ability to effectively communicate, work in a team, and solve complex problems (Business Roundtable, 2017).
In the school district that served as the focus of this study, there is no comprehensive or systematic SEL implementation plan at the elementary level. Although teachers are expected to provide quarterly Learning Behavior grades, the processes for assessing SEL skill development are inconsistent. This aim of this study was to ensure a shared understanding among elementary educators about what SEL entails and how to accurately and consistently report student progress.
This qualitative study explored the knowledge and practices of kindergarten teachers related to SEL, with a focus on two Learning Behaviors—Interpersonal Skills and Collaboration. Twelve kindergarten teachers participated in focus groups, sharing insights about their understanding of SEL and their current approaches to instruction, assessment, and grading. Thematic analysis of the focus group transcripts revealed inconsistent understanding of SEL, a lack of clarity about what behaviors indicate skill attainment, and inconsistency in data collection or grading practices.
Findings suggest that the district should consider reviewing its current SEL efforts to move towards a more comprehensive, systemic implementation model. Professional learning opportunities focused on building a shared understanding of SEL and establishing consistent assessment and grading practices would enable teachers to more accurately communicate student progress to families and other stakeholders
Evaluating Lightning Predictability Over Southeastern South America Using Machine Learning and CloudSat Vertical Profiles
No full textAPPLICATION OF GEOSPATIAL AND STATISTICAL ANALYSIS IN HAZARD ASSESSMENT
No full textThe extent and severity of the hazard impacts experienced by a region are uncertain and highly dependent on its intensity and the geospatial characteristics of that location (e.g., proximity to the coast). This dissertation considers multiple hazards, including floods, sea-level rise (SLR), and tropical cyclones (TC), and investigates their potential adverse effects on contaminated sites and nuclear power plants (NPPs). Several geospatial and statistical tools are used to assess the hazards' characteristics and their interaction with physical and social features.First, the possibility of inundation at contaminated sites (including brownfield, superfund, and toxics release inventory sites) due to flood and SLR is investigated. A framework is proposed that assigns a score (I-Score) to each site based on the probability of inundation, social vulnerability, and the population of communities near each site. The analysis shows that many contaminated sites with a relatively high likelihood of inundation are located in areas with a high Social Vulnerability Index (SVI) and population. A density-based representation of the I-Score for recognizing potential hotspots is presented. The framework proposed in this study could support policymakers in prioritizing contaminated sites for further assessment and action.
Second, geospatial and statistical tools are used to characterize the uncertainty associated with TC predictions and to compare forecasted and observed hurricane track information. Specifically, hurricane track and wind radii (wind radius is the distance from the center of TC that is under the effect of the specific level of wind speed that TC generates) are considered, and uncertainty associated with the timing and location of landfall (in this dissertation is defined as the onset of various storm conditions which is different from the prevalent definition as an intersection of the center of TC with coastline) and the duration of direct storm impacts (e.g., high wind speeds) is characterized. A particular focus is placed on presenting the uncertainty associated with the temporal and spatial characteristics of the TC so that the hazard may be characterized for input into the probabilistic risk assessment (PRA) for NPPs.
Third, models are developed to support the external hazard PRAs for NPPs. NPPs may implement a range of actions to prepare for and protect against natural hazards such as hurricanes. These preparatory actions are intended to mitigate the potential damage caused by these events. However, successful implementation of these preparatory actions requires adequate notifications and sufficient warning time. Thus, comprehensive risk assessments require an understanding of TC forecast errors and uncertainty. The variation of forecast errors in specific parameters (e.g., warning time and strong wind duration) relative to TC geospatial location and maximum winds is explored. Statistical models are developed and adopted to predict the adverse effects of TC and their timing. Then, a Bayesian network (BN) is developed to probabilistically model the relationship of multiple variables, including the relationship between TC-generated wind, flood, and warning time. The BN developed in this dissertation can be connected to other BNs related to human reliability analysis and system failure analysis to provide information regarding external hazards (flood, wind, and their timing)
INVESTIGATING BIOLOGICAL SYSTEMS: MOLECULAR DYNAMICS SIMULATION AND MACHINE LEARNING APPROACHES TO PEPTIDE-LIPID, IONIZABLE LIPID-RNA INTERACTIONS, AND IRON-SULFUR PROTEINS
No full textIn my dissertation, I present an investigation of molecular interactions and iron-sulfur protein through four interconnected research works. In Chapter 2, I characterized the thermodynamics of arginine-phosphate binding, focusing on D-myo-inositol-1,4,5-triphosphate (IP3) and the arginine-glycine-arginine tripeptide (RGR). Additionally, I investigated guanidinium-phosphate interactions in both monoester (such as glycerol-3-phosphate and glucose-6-phosphate) and diester (dimethyl-phosphate (DMP)) configurations using methyl guanidine (MGUA) as a model compound. Through comparison with experimental isothermal titration calorimetry data, I validated the computational binding energies with mono-ester phosphate and refined a specific nitrogen-oxygen interaction parameter in the CHARMM force field for MGUA-DMP interactions to improve the accuracy of molecular simulations. In Chapter 3, I investigated supramolecular interactions between novel ionizable lipids (AMG1041 and AMG1541) and RNA. Through molecular dynamics simulations, I demonstrated that β-hydroxyls significantly enhance RNA binding, with AMG1541 forming more hydrogen bonds than AMG1041 (11.2 vs 9.8) and stronger interaction energies (−136.04 ± 10.70 vs −113.68 ± 24.81 kcal/mol). Removal of β-hydroxyls nearly halved the hydrogen bonds (to 5.17 and 4.4) and substantially reduced interaction energies, providing insights for optimizing mRNA delivery systems. In Chapter 4, I developed a novel machine learning framework for identifying iron-sulfur (Fe-S) cluster-containing proteins. My sequence-based approach, utilizing my curated FeSseqdb database and random forest classification, achieved high precision (0.94 ± 0.01) and F1-score (0.88 ± 0.02). Through this framework, I uncovered key determinants of Fe-S protein identification, particularly the role of cysteine spacing and proline content. Building on this work, Chapter 5 focused on predicting Fe-S cluster redox potentials. I created a regression model that achieved strong correlation with experimental data (R² = 0.82) using only two features: total cluster charge and average Fe atom valence. Applying this model across 9,821 Fe-S clusters from the Protein Data Bank, I achieved 88% agreement with experimental values. Through these four chapters, I have advanced our understanding of fundamental molecular interactions and demonstrated the power of integrating experimental and computational approaches. My refined force field parameters, machine learning frameworks, and interaction analyses contribute valuable tools to the fields of molecular modeling, protein engineering, and drug delivery system design
BIOTIC AND ABIOTIC DRIVERS OF DIVERSIFICATION IN THE OIL-COLLECTING BEE GENUS <i>CHALEPOGENUS</i> (APIDAE: TAPINOTASPIDINI)
No full textThe oil-bee genus Chalepogenus Holmberg (Apidae: Tapinotaspidini) has unresolved systematics, and can serve as a model to study various ecological traits in driving evolution. The genus is restricted to South America and presents specialized interactions with oil-host plants. However, the ecological preferences in the group were never summarized. In this work I aimed to resolve the evolutionary relationships in the genus and to investigate the traits driving its evolution.To accomplish this, in the first chapter I gathered natural history data (i.e., climate, range/biogeographic, floral-oil preferences, morphology) to evaluate differences and similarities within the morphogroups in the genus. Results show that morphogroups in the genus display clear range differences, floral choices and climatic preferences, which in some cases relate to different morphological traits. These differences and their structure suggest that the spatial and evolutionary history of the genus may have driven changes in the climatic and floral preferences of the ancestors of the taxon. Based on these results, I proposed eco-evolutionary hypotheses, to be tested in a phylogenetic tree.
In the second chapter, I used genomic markers and several phylogenetic approaches to build phylogenetic trees and analyze the evolutionary relationships in the group. My results indicate that the genus is not monophyletic, reinforcing the need for a higher-level taxonomic review of the group. Despite this need, our well-supported topologies show that morphogroups and most known species are monophyletic.
After summarizing the natural history data and reconstructing phylogenetic relationships, in the third chapter I test eco-evolutionary hypotheses. With this goal, I first estimated the ages of the group and then performed several diversification and ancestral state reconstruction analyses to analyze the role of the various traits in the evolution of the group. The origin of the group was estimated in the Oligocene, and speciation and shifts in the ancestral ranges, climatic preferences and host-plant preferences were congruent with multiple South American biogeographical and climatic events, especially during the Miocene. These analyses indicate that the evolution of the group was likely initially driven by biogeographic events and that climatic preferences and host plant switches occurred after new regions were colonized.
Generally, this work significantly contributes to the systematics of Chalepogenus bees, while providing a framework for building and testing eco-evolutionary hypotheses based on natural history and phylogenetic data. Moreover, it is an important addition to the knowledge of the biogeographic history of South America, highlighting the importance of investigating the ecology and evolution of understudied biodiversity
EXPLORING SCHOOL–COMMUNITY PARTNERSHIPS AND SUPPLEMENTAL EDUCATION TO CREATE SCHOOLS THAT MAKE A DIFFERENCE
No full textThe purpose of this study was to explore how school–community partnerships and supplemental education programs are implemented in a high-performing school to increase student learning. The following research questions guide my dissertation: How do teachers and school leaders perceive Achievers Academy partnerships and supplemental education programs contribute to the overall education of the school’s students? In what ways does Achievers Academy staff build partnerships and supplemental education activities in their school?
This study employed a single case study methodology with a convergent mixed methods case study design to answer the research questions. Using the case study methodology provided a real-life context with a holistic approach and meaningful characteristics with the hope to inform other educational reforms to improve the student achievement of underserved students.
This mixed methods approach and theoretical framing captured the complexity of the case and connected it with data. I also conducted a document review and semistructured interviews with key school leaders to thoroughly explore my research topic to provide a robust study. The interview protocol provides a detailed investigation of different facets of my research questions regarding standards, expectations, daily practices, community involvement, and collaborative practices and I was able to collect additional data and further explored the intricacies of my case school. I used the school improvement perception survey to capture the perspectives of school key stakeholders on school–community partnerships (Shannon and Bylsma, 2007), and the ASCD (Association for Supervision and Curriculum Development) School Improvement Tool to examine the school’s supplemental education programs as is relates to school improvement in my case school.
Using these data, I examined school–community stakeholders’ perceptions and experiences around school–community partnerships and supplemental education. The school leadership team is part of the leadership structure of a school which often undertakes the crucial role of developing, overseeing, and evaluating the effectiveness and impact of the school’s action plan and has the responsibility for leading the strategic planning process while providing clear and achievable goals and targets. Finally, I analyzed the data collected to examine how school–community partnerships and supplemental education programs contribute to the improvement of minoritized students (e.g., Black, Latinx, and other minoritized students) and their overall community well-being
ANALYSIS AND REFLECTION ON PRODUCING A BANNER YEAR (WORKING TITLE)
No full textThe newspaper industry is in crisis, and journalists are looking for a way to save it. This thesis explores the filmmaking process of a documentary highlighting one specific business model in use at The Baltimore Banner in Baltimore, Maryland. The accompanying film highlights the journalists in action, showing how the newsroom reacts to large breaking news of the Francis Scott Key Bridge collapse on March 26, 2024 in Baltimore. The Banner is a nonprofit news organization run like a startup for-profit newsroom. This paper reviews the nonprofit model and dissects the history of the newspaper crisis. It then deconstructs the filmmaking process and reflects on lessons learned. The thesis affirms that a mix of cinema vérité and sit-down interviews is the proper filmmaking format for the audience to understand why journalism and the nonprofit model are important to a city like Baltimore