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Modeling River Otter (Lontra canadensis) Habitat Suitability using Citizen Science Data
No full textenterThe North American river otter (Lontra canadensis) has undergone population
decline and recovery due to historical overharvesting, habitat loss, and recent
reintroduction efforts. My study models river otter habitat suitability using Maxent in
four Mid-Atlantic states—Pennsylvania, Maryland, Delaware, and New Jersey—using
citizen science presence-only data from iNaturalist. I incorporated environmental
variables (wetlands, forests, and stream density) and anthropogenic factors (harvest
rates and human population density) to assess their relative contributions. The full
model, which included all five covariates, performed best (AUC = 0.812), with an
increasing harvest rate as the strongest predictor. Environmental-only (AUC = 0.731)
and anthropogenic-only (AUC = 0.785) models performed less effectively, supporting
the hypothesis that both types of variables improve predictive accuracy. Wetlands and
moderate human population density positively influenced habitat suitability, while
detectability biases affected remote or heavily urbanized areas. These results
demonstrate the value of combining citizen science data with spatial modeling to
assess habitat use for semi-aquatic mammals like the river otter in human-dominated
landscapes.ente
Nudgeable, to a degree: an experimental examination of temperature defaults in university residence halls
No full textPalm-Forster, Leah H.Air conditioning and heating are the two largest categories of residential energy use. We conducted a field experiment across 566 dorm rooms at the University of Delaware to test whether temperature setting defaults can be used to reduce energy consumption. Treatments, applied using a between-subject design, varied the default temperature and how frequently the default was reset. Post-experiment survey data are used to identify relevant psychological channels through which the default effect is activated, along with residents’ emotional reactance to the default. Using difference-in-differences regression models, we find the presence of default effects in all treatments. This default effect appears to be primarily driven by the effort required to repeatedly change away from the default temperature, concern for others’ comfort, and a lack of knowledge about how the dorm room thermostats work. Residents’ perceptions of the experiment were neutral to slightly positive on average, but the welfare effects of the default remain unclear as some residents maintained default settings simply because they did not believe they could change the thermostat setting. A supplemental field experiment finds that, relative to the status quo, winter energy consumption and operating costs of the dorm room fan coil units can be cut ~28% through more efficient heating setpoints, and an additional ~9% through weekly reinforcement of a temperature default. These results demonstrate that small temperature defaults may be a promising way to reduce energy consumption and costs without provoking a negative response from occupants. Future research is needed to understand the effect of temperature defaults in warm seasons and to clarify welfare effects, particularly when residents lack understanding about how to operate their thermostats.University of Delaware, Department of Applied Economics and StatisticsM.S.Univerity of Delaware, Water Science and Policy Progra
Do you know them?: maintaining Black family bonds during Reconstruction
No full textMaloba, Wunyabari O.Freedom, for freed people in the United States, could take several forms, but the reunification of family was a priority for most, if not all. The federal government, their resources, and the state government, though tasked with aiding the reunification process during Reconstruction provided little support and often prevented the reunification process with laws and societal expectations thrust on freed people. I analyze the federal and state government’s role in the reunification process, and freed people’s response to their intervention, through three methods: marriage, child apprenticeship, and information wanted advertisements published in the newspapers. The tenacious attitude to maintain and rekindle relationships lost by slavery are a significant Africanism found in the freed population and crucial to their survival after slavery.University of Delaware, Department of Africana StudiesM.A
Structural Response of Bijels Stabilized by Ellipsoidal Magnetic Particles
No full textThis preprint has not undergone peer review (when applicable) or any post-submission improvements or corrections. The Version of Record of this contribution is published in Lecture Notes in Computer Science ((LNCS,volume 15909)), and is available online at https://doi.org/10.1007/978-3-031-97564-6_19
http://creativecommons.org/licenses/by/4.0/
© 2025 The Author(s), under exclusive license to Springer Nature Switzerland AG
This article was originally published in Lecture Notes in Computer Science ((LNCS,volume 15909)). The version of record is available at: https://doi.org/10.1007/978-3-031-97564-6_19Bicontinuous interfacially jammed emulsion gels (bijels) are soft materials characterized by an interconnected network of fluid domains stabilized by colloidal particles. Their tunable microstructures make them promising candidates for applications in material templating, membrane separations, and drug delivery. In this study, we explore how magnetic fields influence the post-formation structural evolution of bijels stabilized by magnetically responsive ellipsoidal particles. Using hybrid Lattice Boltzmann–Molecular Dynamics simulations, we examine the response of systems stabilized by oblate and prolate particles across a range of magnetic field strengths (¯B = 0, 0.2, 0.5, 1). We quantify structural evolution through metrics including domain size, average interfacial tilt angle and six-fold Steinhardt bond orientational order. Our findings reveal that particle shape mediates the extent of anisotropy and domain coarsening, with prolate particles promoting ordering and alignment, while oblate particles tend to disrupt local structure. Finally, we compare bijels formed under an applied field to those exposed post-formation, showing that magnetic alignment can effectively tune microstructure in both cases to an approximately equal degree, highlighting a viable route for post-processing control of responsive bijel materials.This work was supported by the National Science Foundation under NSF Award DMR-2414458 and OIA-2346036. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect those of the National Science Foundation. This work used
NCSA Delta GPU at the National Center for Supercomputing Applications through allocation PHY220131 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program, which is supported by National Science Foundation grants #2138259, #2138286, #2138307, #2137603, and #2138296
Short-term estradiol administration does not restore endothelin‐B receptor‐mediated vasodilation in postmenopausal women
No full textThis article was originally published in American Journal of Physiology - Heart and Circulatory Physiology. The version of record is available at: https://doi.org/10.1152/ajpheart.00815.2024.
Copyright © 2025 The Authors. Licensed under Creative Commons Attribution CC-BY 4.0 (http://creativecommons.org/licenses/by/4.0/). Published by the American Physiological Society.The endothelin-B receptor (ETBR) mediates vasodilation in young women, an effect that is absent in postmenopausal women. We have previously demonstrated that ETBR-mediated vasodilation is regulated by estradiol (E2) in young women; however, the impact of E2 on ETBR function in postmenopausal women remains unknown. Accordingly, the objective of this study was to test the hypothesis that E2 exposure restores ETBR-mediated dilation in postmenopausal women. Ten healthy postmenopausal women (55 ± 2 yr of age, 5 ± 3 years since menopause) completed the study. E2 was administered by transdermal patch for 7 days (0.1 mg/day, Vivelle-Dot patch). Vasodilation in the cutaneous microcirculation (microvascular endothelial function) was measured via local heating (42°C) using laser Doppler flowmetry combined with intradermal microdialysis perfusions of lactated Ringer’s (control) and ETBR antagonist (BQ-788, 300 nM) at baseline and after E2 administration. There was no effect of E2 on ETBR function [hormone × site, F(1,9) = 0.77, P = 0.40]. These data demonstrate that in contrast to findings in premenopausal women, E2 administration does not restore ETBR function in postmenopausal women.
NEW & NOTEWORTHY
The vascular endothelial endothelin-B receptor (ETBR) mediates vasodilation in premenopausal women, an effect modulated by estradiol. ETBR-mediated vasodilation is lost in postmenopausal women, but the effect of exogenous estradiol administration on ETBR function in postmenopausal women is not known. During estradiol administration, ETBR blockade did not affect cutaneous microvascular vasodilatory response to local heating. We demonstrate that exogenous estradiol administration does not restore ETBR-mediated vasodilation in postmenopausal women.This work was supported by the AHA Award Grants 16SDG30700015 (PI: M. M. Wenner), NIH R01 HL 146558 (PI: M. M. Wenner), and NIH P20 GM 113125 (PI: D. G. Edwards)
Sustainable production of value-added chemicals from food waste and forest residues
No full textVlachos, Dionisios G.Over 80% of global energy and more than 90% of chemical products are derived from fossil fuels, making them a dominant driver of greenhouse gas emissions. The escalating demand for energy and chemicals, alongside increasing environmental awareness and stringent greenhouse gas emission regulations, highlights the critical need for renewable alternatives. Forest residues and food waste (FW) are promising resources to meet these demands sustainably. In addition to feedstock selection, a sustainable biorefinery relies on conversion technology, and high-value products while maintaining cost-effectiveness, energy and carbon efficiency. In this thesis, we investigate conversion of FW and forest residues into value-added chemicals via economic and environment-friendly processes. ☐ The extraction of phenolic acids from FW prior to thermocatalytic valorization is crucial for enhancing resource efficiency and economic gains. In Chapters 2-4, we address the key knowledge gaps in phenolic acids extraction from diverse FW feedstocks. In Chapter 2, we establish a blueprint for solvent selection, offering new insights into phenolic acids extraction from FW. A high-performance solvent is identified, and its utility is demonstrated on potato peel waste. In addition, a strategy for replacing highly soluble toxic solvents with green mixtures is presented. Chapter 3 focusses on understanding the impact of feedstock heterogeneity on microwave heating and extractive yields. We demonstrate that the heating of FW-extractant mixtures is unaffected by the FW dielectric properties, as uniform mixing occurs at a 0.05 solid-to-liquid ratio (g/mL). The enhanced heat and mass transfer in high-moisture FW improves target acid yields, governed by the acid’s concentration in free and bound forms. We elucidate intermolecular interactions among various FW components that yield higher phenolics in mixed FW compared to a simple additive model and provides new insights into developing versatile MAE strategies for treating diverse feedstocks. Finally, Chapter 4 presents synthesis of a molecular imprinted polymer to selectively separate commercially valuable phenolic acids from a FW-extracted mixture. A biobased monomer is identified for synthesis of the polymer, providing the highest separation factor for chlorogenic acid compared to traditional monomers. HSPiP is employed to screen synthesis solvents and functional monomers. The data indicates that the extraction solvent interacts with the polymer, influencing its performance. We propose a separation strategy utilizing the synthesized polymer and apply it to potato peel and coffee bean waste extractive mixtures, analyzing its economic and environmental advantages over commercial alternatives. ☐ In chapter 5, we direct our attention to reductive catalytic fractionation of forest residues of three tree parts (bark, twigs/branchlets, leaves) collected in four phenophases (senescence, leafless, emergence, and leafed for deciduous trees) from four co-occurring species (Betula lenta L., Fagus grandifolia Ehrh., Liriodendron tulipifera L., and Pinus rigida Mill). We examine the impact of phenophases, species and tree part on the lignin content, total phenolic monomer, S, and G units yields. Generally, bark has the highest lignin content, followed by twigs/branchlets and leaves. Further, the forest residues collected in leafed phenophase provide the highest total phenolic monomer yields, making them more effective for lignin valorization. This work introduces simple harvesting strategies for targeting specific monomers and products for biorefineries.University of Delaware, Department of Chemical and Biomolecular EngineeringPh.D
MARRIAGE AND OTHER UNEXPECTED PARTIES: QUEER JOY IN CONTEMPORARY SHAKESPEARE ADAPTATION
No full textenterAt first glance, Shakespeare and queer joy may seem completely unrelated.
First performed in the 16th and 17th centuries (before the term “queer” as we know it
existed), Shakespeare’s work has been criticized for perpetuating racist narratives,
supporting white nationalism, and establishing normative ideas of the human. Queer
joy, on the other hand, is a relatively new term. And essential to concept of “queer” is
a position against normative ideas of sexuality and gender and a desire to build
coalitions with those multiply marginalized by heteronormativity. Centering on my
experiences of queer joy while viewing the Wilma Theater’s filmed Fat Ham (James
Ijames’s Black, queer adaption of Hamlet) and gender-nonconforming adaptation of
Twelfth Night from 2023, this thesis asks what Shakespeare can offer queer joy.
I draw from seminal queer theory texts and work in queer affect studies to
theorize queer joy as a survival tool for queer life. Queer joy exists alongside
negativity and the inevitable struggle of living out of alignment with
heteronormativity, bringing better worlds into the present and motivating resistance.
Building on the work of critical race theorists on appropriating Shakespeare and Early
Modern sexuality studies, I argue that it is the adaptability of Shakespeare and his
existence before the institutionalization of modern structures regulating sexuality and
gender that make his work useful for queer joy. Performing queer joy in Shakespeare
adaptation shows that nonnormative gender and sexuality have historical precedent
and have always persisted, even in times of oppression. At a time when the U.S.
government is dismantling legal protections and recognition for so many, the radical
persistence of queer joy in Shakespeare is more essential than ever.ente
Advancing conversational information system: enhanced context understanding, knowledge grounding, and synergistic framework
No full textFang, HuiThe increasing prevalence of conversational interfaces necessitates the development of robust Conversational Information Systems (CIS) capable of understanding context-dependent user needs and providing accurate, grounded information through interactive dialogue. However, designing effective CIS faces significant challenges, including resolving linguistic ambiguity, managing evolving context, ensuring knowledge grounding (especially with Large Language Models), developing effective interaction strategies, and creating suitable evaluation methodologies. This thesis addresses these challenges across core CIS domains and explores the extension of underlying principles to complex information processing tasks mediated by collaborating intelligent agents. ☐ We first investigate ambiguity resolution in Conversational Text Retrieval (CTR). We propose a mixed-initiative framework leveraging user feedback for clarification and introduce ZeQR, a novel zero-shot query reformulation technique that reframes context understanding as a machine reading comprehension task, eliminating the need for conversational training data. Subsequently, we focus on Conversational Recommender Systems (CRS). We introduce Behavior Alignment, a novel metric for evaluating the strategic alignment of LLM-based CRS with human interaction patterns, addressing shortcomings in existing evaluation methods. We also develop ReGeS, a synergistic Retrieval-Augmented Generation (RAG) framework that enhances knowledge grounding and recommendation accuracy through reciprocal interaction between retrieval and generation components. ☐ Finally, recognizing that the principles of iterative, context-aware, and collaborative information processing extend beyond human-machine dialogue, we explore their application in multi-agent systems. We present DocAgent, a multi-agent collaborative system employing dependency-aware processing to generate grounded documentation for complex source code. This serves as a case study demonstrating how CIS interaction paradigms can be adapted for orchestrating agent-agent collaboration on sophisticated, structured information generation tasks. ☐ Collectively, this research advances the state-of-the-art by providing novel methods for context understanding, knowledge grounding, system evaluation, and synergistic design in CIS. It highlights the evolution of conversational paradigms towards multi-agent collaboration and contributes to building more intelligent, reliable, and effective systems for interactive information access and processing.University of Delaware, Institute for Financial Services AnalyticsPh.D
SYSTEMATIC IDENTIFICATION AND VALIDATION OF CYCLIC NUCLEOTIDE RECEPTORS IN BACTERIA
No full textCyclic nucleotide-based signaling plays a central role in bacterial antiviral de-fense systems such as CBASS. These systems rely on a diverse array of cyclic nucleo-tide second messengers (cNSMs) to initiate immune responses upon phage infection. However, the full spectrum of protein receptors that detect these molecules remains largely uncharacterized. This study aims to expand our understanding of cNSM sig-naling, specifically involving cyclic UMP, cyclic UMP-AMP, cyclic GMP-UMP, and cyclic AMP-AMP-GMP, by identifying novel receptor proteins in bacteria and exper-imentally validating their interactions.
To achieve this, proteomic mass spectrometry analyses were performed on pull-down assays using bacterial cell lysates, with the cNSMs as baits. Candidate re-ceptors were identified based on selective enrichment and further prioritized using bioinformatic analysis. Subsequent biochemical validation involved gene cloning, recombinant protein expression, and purification. Differential scanning fluorimetry (DSF) was employed as a primary screening technique to assess ligand-induced stabi-lization of protein targets.
Our findings demonstrate that this systematic workflow, combining pull-down proteomics with DSF screening, offers a robust, efficient, and reliable methodology for receptor identification. Importantly, we identified a promising candidate protein that binds cyclic UMP (cUMP), highlighting a potentially novel receptor involved in cNSM-mediated signaling. These results could potentially contribute to our under-standing of bacterial signaling networks and regarding the immune regulation mech-anisms
What Does Play Have to Do With It? A Concrete and Digital Spatial Intervention With 3-Year-Olds Predicts Spatial and Math Learning
No full textThis article was originally published in Developmental Psychology. © American Psychological Association, 2025. This paper is not the copy of record and may not exactly replicate the authoritative document published in the APA journal. The final article is available, upon publication, at: https://doi.org/10.1037/dev0001904.Spatial skills like block building and puzzle making are associated with later growth in science, technology, engineering, and mathematics learning. How these early spatial experiences—both in concrete and digital platforms—boost children’s spatial skills remains a mystery. This study examined how children with low- and high-parental education use corrective feedback in a series of spatial assembly tasks. We further ask whether this spatial learning increases near- and far-transfer spatial and math skills. U.S. preschoolers (N = 331) were randomly assigned to either a “business-as-usual” control or one of six spatial training groups (comprising concrete and digital training with modeling and feedback [MF], gesture feedback, or spatial language feedback). Children were trained for 5 weeks to construct 2D puzzles that match a model using a variety of geometric shapes. Pre- and posttests evaluated 2D and 3D spatial assembly, spatial language comprehension, shape identification, and math performance. Results indicate performance enhancement in trained 2D spatial assembly across all six trainings. Digital gesture feedback transferred, boosting 3D spatial assembly performance. Both concrete and digital spatial language feedback trainings increased shape identification performance. Concrete-MF significantly (and digital-MF marginally) increased word problem math performance for children with lower parental education. Finally, collapsing across conditions, both concrete and digital training increased overall spatial skills, especially for preschoolers with lower parental education. Transfer to overall mathematics performance was far less robust. Overall, early concrete and digital spatial assembly experiences seem to support preschoolers’ spatial skill development but have a minor impact on mathematics skill development.
Public Significance Statement
Understanding how different types of spatial training impact children’s learning can inform the design of effective interventions to enhance science, technology, engineering, and mathematics skills, particularly among those from underresourced backgrounds. Results from the present study suggest that spatial assembly training improved spatial skills and possibly math word problem skills of children with lower parental education. This research illustrates the potential of both concrete and digital spatial assembly in fostering early spatial ability and possibly math ability, offering promising avenues for equitable and accessible educational interventions.This research was supported by an Institute of Education Sciences Grant R305A140385 awarded to RMG and KHP. We want to thank Maya Marzouk, Jelani Medford, Lindsey Foster, Siffat Islam, Amanda Cibischino, and Calla Pritulsky for their help with the set-up and data collection of this project as well as FlickerLab who helped to create the digital app component in the current study. We would also like to thank all the children who participated, their parents, and our preschool partners in northern Delaware and the Philadelphia area