31825 research outputs found
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See our crowns: an analysis of Black Girls' experiences in American high schools and the impact of Africana Womanism
No full textFontnette, AliciaPorcher, KishaFor the purpose of this work, any and all mentions of Black Girls are inherently inclusive of Black Queer, Black Non-Binary, Black Transgender, and Black Non-Gender-Conforming students and their intersectional identities. The work conducted in this project details the experiences of Black Girls in American schools. Trends in exclusionary discipline in American high schools (specifically in Delaware and in Illinois) were analyzed, revealing significant disparities between Black and white girls. There was also a deep erasure of the perspectives, the knowledges, and the experiences of Black Girls, which is the by-product of a system rooted in colonial conditioning. Disciplinary data and Black Girls’ oral histories were combined to generate insights on reinventing schooling and education as locations of safety, of community, of healing, and of personal development for Black Girls and Black Queer people, as well as all other students. ☐ Keywords: African-American Studies, Black Girlhood Studies Education, PedagogyUniversity of Delaware, Department of Africana StudiesM.A
Distribution of buoyant tracers in an idealized tidally averaged estuarine circulation model with application to the Delaware Bay
No full textKukulka, TobiasBetween the river and the ocean lies a highly dynamic and complex system, an estuary, that acts as a critical trap for marine debris originating from both land and fluvial sources. In this study, an idealized tidally averaged estuarine circulation model for the gravitationally driven circulation was applied to predict tracer transport and marine debris pathways using a tracer conservation equation that incorporates multiple transport processes. The modeling results reveal that tidal mixing, estuarine depth, and width determine the estuarine circulation strength and structure. Lateral surface flows converge over the deeper channel center aggregating buoyant tracers there. At the bottom of the channel center lateral currents diverge resulting in enhanced tracer concentrations of sinking particles near the estuarine flanks. An analysis of high-resolution satellite imagery of Delaware Bay suggests that buoyant material frequently aggregates near the estuarine channel in narrow bands that extend along the estuary, consistent with model results. These aggregation zones are more often observed during winter than other seasons. Finally, the cross-sectionally averaged tracer concentration of a neutrally buoyant tracer is modeled based on a balance between transport by river flow, along-estuary tidal mixing, and shear dispersion by the estuarine exchange flow. The along-channel distribution of the tracer concentration is controlled by a nondimensional number (a Peclet number) that describes the relative importance of advection by river flow and along-estuary mixing. For stronger mixing, tracer concentration gradients are more constant along the estuary. Together, these insights offer an integrated framework to better predict and manage marine debris accumulation in estuaries.University of Delaware, School of Marine Science and PolicyM.S
Growing Healthy Ecosystems in the C&D Canal - Summit North Marina
No full textThis project plans to use the marina to explore, demonstrate, and test different types of green stormwater infrastructure, shoreline restoration, and other restoration tactics which could work to mitigate ecological issues the canal and greater Chesapeake Bay face. In addition this will expose the local communities and visitors to tactics that help them understand the importance of a healthy ecosystem and educate them of the issues in supporting the ecosystems of the canal and bays.Wik, AnnaZimmerman, Jame
Identification of the Wnt maturation complex
No full textSelva, Erica M.Wnt signal transduction is fundamental to human development and is responsible for maintaining cellular homeostasis later in life. During development, reduced or absent Wnt signaling results in a wide range of developmental defects and aberrant signaling in adults is recognized as a primary driver of cancers. Strikingly, Wnt signaling is so indispensable to bodily function that any perturbation or disruption throughout the pathway can lead to developmental defect or cancer; prominent examples include focal dermal hyperplasia, osteogenesis imperfecta, and colorectal cancer. While the numerous Wnt ligands and target receptors in receiving cells have been extensively studied, the maturation of virtually all Wnt ligands within sending cells is relegated to highly conserved yet understudied components, Porcupine (Por) and Wntless (Wls). Our initial characterization of Por and Wls function within the model organism Drosophila melanogaster to produce functional Wnt has informed much of our understanding of Wnt ligand maturation. Further characterization of the mechanisms by which these players interact to produce mature, active Wnt ligand is essential to better delineate how Wnt signaling is regulated. ☐ Herein we provide identification and initial characterization of the Wnt Maturation Complex. We discovered that Wls forms homo-dimers dependent upon intermolecular disulfide bridge formation, and these Wls dimers interact with both Wnt and Porcupine (2:1, Wls-Wnt, Wls-Por). Remarkably, this provides a universal mechanism for Wls dimerization and a possible explanation for the uncharacterized Wnt hand-off between Por and Wls in early ER Wnt processing. The overarching goals of this work are two-fold: to characterize disulfide bonded Wls dimer interactions in forming Wnt maturation complexes and to characterize disulfide bonded Wls dimer importance in Wnt post-translational modification, secretion, and signaling. We have generated various tagged forms of Drosophila Por and Wls wild-type (WT) and conserved cysteine mutants that are used in co-immunoprecipitation experiments to examine the importance of Wls disulfide bonds in forming early Wnt maturation complexes. To determine if Wls cysteine mutants affect post-translational modification, secretion, and signaling, we used readouts of Wnt N-glycosylation by western blot, secretion into media by western blot, and canonical Wnt signaling activity indicated by ß-catenin levels in western blot and by transcriptional reporter assays. This work will lead to an understanding of how Wls dimers function within a cell to produce functional Wnt ligand, impacting our comprehension of Wnt cellular dynamics, processing, and secretion mechanisms. Results from this work have the potential to identify targeted therapeutics for diseases fueled by aberrant Wnt signaling.University of Delaware, Department of Biological SciencesM.S
Essays on educational inequalities
No full textShores, KennethThis dissertation presents three empirical studies examining critical issues in U.S. education policy and finance—specifically, how policy design and institutional contexts either mitigate or reproduce inequities in school funding, instructional quality, and career readiness. Each chapter addresses a distinct dimension of K–16 schooling in the United States, and collectively they offer insights into the multifaceted ways that resources, instructional reforms, and career preparation intersect with equity goals. ☐ Paper One investigates Title I, the largest federal educational grant aimed at supporting low-income students in K–12 schooling. Using a stacked regression discontinuity design, I examine whether Title I truly supplements district budgets or crowds out state and local revenue. The findings suggest that, while large-scale displacement of operating funds is not apparent, some districts respond by reducing capital outlays and bond elections—especially those with larger Title I allocations. These results underscore how evolving institutional characteristics can affect district-level fiscal behavior. ☐ Paper Two (with Dr. Florence Ran) analyzes corequisite remediation in community colleges, a widely adopted reform intended to improve the success of academically underprepared students in college-level coursework. Using administrative data from the Tennessee community college system and employing difference-in-differences and event study analyses, this study shows that corequisite models improve gateway course completion for students across a range of academic readiness levels. However, these positive impacts vary by student preparedness, and students were more likely to drop out of the public college system after the reform—highlighting the need for additional supports. ☐ Paper Three (with Dr. Kenneth Shores and Arielle Lentz) examines high school Career and Technical Education (CTE) programs and their potential role in shaping future wage inequality. Linking Delaware’s administrative data with occupational wage information, this paper explores wage disparities across student subgroups and investigates the sources of these gaps. The results reveal notable differences in expected wages: female–male wage gaps arise largely from within-school factors, whereas racial and socioeconomic gaps primarily reflect across-school differences. These patterns suggest that high school career programs, though seemingly neutral, may inadvertently produce gaps in students’ future earnings. ☐ Taken together, these three papers illustrate how equity considerations are woven into the fiscal, curricular, and structural facets of U.S. education. By identifying unintended consequences of policy interventions, this dissertation provides policy-relevant evidence on how educational systems can better serve all students.Ph.D.University of Delaware, Education and Social Policy Progra
Vibration-Mediated Recovery of Irradiated Osteocytes and Their Regulatory Role in Breast Cancer Bone Metastasis
No full textThis article was originally published in Advanced Healthcare Materials. The version of record is available at: https://doi.org/10.1002/adhm.202501689
©2025 The Author(s). Advanced Healthcare Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, https://creativecommons.org/licenses/by/4.0/, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Radiotherapy is a cornerstone of breast cancer treatment, but it can unintentionally damage bone, causing bone loss and pain, with no currently effective therapeutic strategy available. While chemically mediated radioprotection is extensively studied, mechanically mediated radioprotection remains underexplored. Given its safety and efficacy, this work examines the potential of low-magnitude, high-frequency (LMHF) vibration as a non-invasive intervention to protect irradiated bone, focusing on osteocytes—the primary mechanosensors and regulators whose functions extend to modulating breast cancer bone metastasis. These results demonstrate that LMHF vibration (0.3 g, 60 Hz, 1 h) mitigates osteocyte apoptosis and upregulates cytoskeletal markers following 8 Gy irradiation. LMHF vibration applied 1 h per day over 3 days restores the regulatory function of irradiated osteocytes in controlling breast cancer extravasation in a microfluidic platform. A combined approach integrating vibration with radiotherapy further reduces cancer invasion and extravasation, demonstrating a compound effect. RNA sequencing (RNA-seq) analysis reveals that this osteocyte-mediated regulation is possibly driven by the Wnt signaling pathway. These findings highlight the potential of LMHF vibration in enhancing radiotherapy efficacy by protecting osteocytes and reducing breast cancer metastasis, underscoring the promise of a non-invasive mechanical intervention in preserving bone health and optimizing cancer treatment outcomes.The authors sincerely appreciate Jiann Rin Ng, Karim Mansour, Max Mizrahi, and Norbert Tanacs for their contributions to the design and fabrication of the LMHF vibration platform. The authors also sincerely thank Jeremy Newton from Dr. Edmond Young’s lab for his assistance with plasma bonding, Hongyu Zhao from Dr. Xi Huang’s lab for support with the DNA damage assay, Aojun Jiang from Dr. Yu Sun’s lab for assistance with reagent procurement, and Dr. Axel Guenther for providing the irradiator permit. This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant
(RGPIN-2019-07056)
Using BRUVS to Characterize the Community of Sandy Shoal Habitats of the Mid-Atlantic Bight
No full textenterThis study explores the biodiversity and community structure of two sandy
shoal habitats on the East Atlantic coast of the United States: Sandbridge (Virginia)
and Hens and Chickens (Delaware). Two different methodologies were used to
characterize the communities: Baited Remote Underwater Video Surveillance/Systems
(BRUVS) and longlines. We assess species relative abundance (MaxN) and diversity,
evenness, and richness using Shannon’s Diversity Index, Simpson’s Diversity Index,
Pielou’s Evenness, and species richness metrics. We then examine environmental
covariates such as water temperature, brightness, depth, distance from shore,
proximity to the closest estuary, and tidal stage at both sites to determine if the
environment drives differences in community composition. Generally, species
diversity and richness were greater at Sandbridge. However, we observed no
significant differences in biodiversity indices between the two locations, most likely
due to a small sample size of videos. Our findings also reveal significant differences in
environmental variables between the two shoals, particularly in brightness and the
distances from shore and the closest estuary. Brightness exhibited a positive linear
relationship with diversity indices and richness, suggesting that less turbid habitats
may support more complex communities. Distance to the closest estuary presented a
negative linear relationship with evenness, indicating that further proximity to the
estuary may maintain a more balanced distribution of species. These trends also
highlight that BRUVs are dependent on clear water conditions to effectively record
data. This study also touches on the significance of using multiple sampling
techniques to better assess marine compositions and diversity. Long-lining and
BRUVS yielded distinct species captures with minimal overlap, indicating different
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biases and strengths of each method. Water turbidity (brightness) limited species
detection and identification, particularly at Hens and Chickens, highlighting a
limitation of BRUVS in turbid waters. This study also suggests further research into
temporal variations, additional environmental factors, and enhancements to sampling
methods to improve biodiversity assessments.ente
Biochar-phytagel hydrogel enhances growth, nutrient uptake, and drought resilience of lettuce microgreens
No full textThis article was originally published in Journal of Agriculture and Food Research. The version of record is available at: https://doi.org/10.1016/j.jafr.2025.102573
Under a Creative Commons license https://creativecommons.org/licenses/by-nc-nd/4.0/Soil-free cultivation systems require substrates that can provide both moisture and nutrients to sustain plant growth. Biochar, a carbon-rich product of biomass pyrolysis, is well known for improving soil water retention and nutrient availability, yet its role in hydrogel-based substrates remains under-explored. In this study, corn-derived biochar (1–10 % w/w) and biochars from cocoa husk, nutshell, bamboo, and poultry litter (5 % w/w each) were incorporated into phytagel hydrogels for lettuce (Lactuca sativa) microgreens. Germination rates were comparable across treatments (72–74 %), although emergence was modestly delayed in biochar composites. At 70 % relative humidity (RH), biochar amendments enhanced shoot elongation (up to 12.2 ± 0.3 cm vs. 9.8 ± 0.4 cm in the control), root growth (6.0 ± 0.4 cm vs. 4.0 ± 0.4 cm), and fresh biomass (2.4 ± 0.03 g vs. 1.6 ± 0.1 g). Under reduced humidity (50 % and 30 % RH), biochar-phytagel substrates buffered moisture loss, preserved chlorophyll contents, and maintained leaf water above 90 %, whereas the control fell below 88 %. Nutrient profiling further revealed significant increases in phosphorus, potassium, calcium, magnesium, and micronutrients (Fe, Zn, Cu, Mn, etc), particularly in 5–10 wt % corn and poultry litter biochars. These results demonstrate that biochar-hydrogel composites enhance both the resilience and nutritional quality of microgreens under moisture limitation, offering promising substrates for sustainable controlled environment agriculture.This work was supported and sponsored by the Natural Resources Conservation Service, US Department of Agriculture, through the grant program Partnership for Climate-Smart Commodities, grant number: NR243A750004G028
Utilizing non-thermal atmospheric plasma (NTAP) for electrified chemical manufacturing and enhanced catalysis
No full textVlachos, Dionisios G.As climate change accelerates, decarbonizing the chemical industry, one of the largest contributors to greenhouse gas emissions, has become increasingly urgent. This substantial contribution stems largely from the industry’s heavy reliance on fossil-fuel energy and carbon-intensive thermal processes. Process electrification offers a promising pathway to replace these fossil fuel-based processes with cleaner, more efficient alternatives powered by sustainable electricity. Among these, non-thermal atmospheric plasma (NTAP) emerges as a versatile electrified platform due to its non-equilibrium nature, which enables molecular activation at ambient temperatures and pressures, overcoming activation barriers without the need for combustion-based heating. ☐ This dissertation investigates the application of NTAP to decarbonize chemical production through direct chemical transformations, particularly of plastic waste and its derivatives, as well as through catalyst enhancement. Chapters 2 and 3 explore the chemical transformation of abundant and inert liquid n-alkanes into long-chain oxygenates via the plasma-liquid interface, with Chapter 3 advancing this work through process intensification using a continuous-flow biphasic microreactor. This reactor design enhances the plasma-liquid interfacial area, enabling higher production rates and improved efficiencies, while offering modularity and scalability. ☐ Building on this foundation, Chapter 4 demonstrates the extension of this platform to plastic waste-derived paraffins, enabling the transformation of plastics and biomass waste into renewable surfactants. These hybrid waste-derived surfactants exhibit superior performance compared to commercial surfactants produced from fossil fuels. In Chapter 5, the scope of plasma-assisted plastics upcycling is further expanded through the development of a novel NTAP method for bulk oxidation of polymers such as low-density polyethylene (LDPE). These bulk-oxidized LDPE materials serve effectively as compatibilizers in mixed plastic blends, offering a promising route for recycling mixed plastic waste streams. ☐ Chapter 6 continues the theme of plastics upcycling, shifting focus to the recycling of per- and polyfluoroalkyl substances (PFAS)-coated textiles. We demonstrate that NTAP is a highly effective method for removing polymeric PFAS coatings from UV- and water-resistant textiles, outperforming conventional Soxhlet and microwave extraction. In addition to removing the majority of PFAS coatings, plasma treatment transforms hydrophobic fabrics into hydrophilic ones, thereby enhancing glycolysis depolymerization through improved solvent uptake. ☐ Finally, Chapters 7 and 8 pivot to utilizing NTAP as a surface activation technique for catalyst engineering. Chapter 7 demonstrates rapid surface oxidation activated carbon supports via NTAP, enhancing metal dispersion. Chapter 8 employs a plasma-based method for complete ligand removal from nanocatalysts without altering particle morphology. Both approaches contribute to improved catalytic performance for key biomass transformations. ☐ Collectively, this dissertation establishes NTAP as a powerful electrified technology for decarbonizing chemical production by enabling new pathways for hydrocarbon valorization, engineering advanced catalysts, and advancing sustainable chemical manufacturing.University of Delaware, Department of Chemical and Biomolecular EngineeringPh.D