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Theorizing supportive messaging for alcohol-related with a test of the cognitive-emotional theory of esteem support messages
No full textCrowley, John P.Social support helps students to cope with the harmful effects of regrettable alcohol-related consequences. Prior work on the Cognitive-Emotional Theory of Esteem Support Messages (CETESM) shows how messages provided to those facing esteem-threatening circumstances vary. The CETESM posits that messages differ in their content-focus (i.e. emotion- vs. problem-focused) and linguistic style (i.e. assertive vs. inductive). This study uses the CETESM to test a between-subjects factorial design where message content-focus and style are simultaneously varied to see which message features are strongest predictors of state self-esteem improvements, perceived behavioral control, and intentions to control drinking. The findings of the study indicate that emotion-focused (EF) messages are significantly more effective at eliciting state self-esteem improvements than problem-focused (PF) messages which are no more effective than messages with no EF/PF-content. Implications for theoretical development and the application of the findings are discussed. ☐ Keywords: self-esteem, social support, regret, messages.University of Delaware, Department of CommunicationM.A
Biobased chemical recycling: aminolysis of PET using renewable reagents and monomers to synthesize new semi-aromatic polyamides
No full textThis article was originally published in RSC Sustainability. The version of record is available at: https://doi.org/10.1039/D5SU00547G
© 2025 The Author(s). Published by the Royal Society of Chemistry
This article is licensed under a Creative Commons Attribution-Non Commercial 3.0 Unported Licence.Chemical recycling of PET is a method of depolymerizing polymer chains to monomeric components enabling the synthesis of second-generation materials with virgin-like quality. Commercial chemical recycling techniques rely upon high pressure methanolysis to create precursors capable of synthesizing a second-generation PET resin. However, despite the circular approach of methanolysis, a product with a very short lifespan and similar value is created. The approach of the current study is to utilize aminolysis as an ambient pressure technique to create precursors for higher value materials with longer lifespans to address the current crisis in plastic waste. Semi-aromatic polyamides (SAP) are desired in this circumstance because of their high melting point and heat resistance combined with good meltprocessability similar to aliphatic polyamides. In this study SAPs were synthesized using precursors recovered from the aminolysis of PET employing biobased diamines and dicarboxylic acids. While aminolysis has been explored in previous studies, this work investigated the use of biobased components from castor oil: decamethylene diamine during recycling and sebacic acid during polymerization. Polymer synthesis resulted in the formation of SAPs similar to polyphthalamides (PPA) with novel structures given the aromatic portion from terephthalic acid (TPA) and aliphatic portion from the diamines and diacids. The synthesized materials exhibited excellent thermal stability with high glass transition temperatures. Novel polymers were created with varying aliphatic chain length to understand fundamental parameters needed to produce a valuable polymer from post-consumer waste.This work was supported as part of the AIM for Composites, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at Clemson University under award #DE-SC0023389
Dual fluorine tag incorporation into SARS-CoV-2 NNTD Protein for 19F NMR spectroscopy
No full textPolenova, TatyanaThis master’s thesis describes efforts towards the development and application of a dual fluorine labeling strategy for 19F nuclear magnetic resonance (NMR) spectroscopy. Using the SARS-CoV-2 nucleocapsid N-terminal domain (NNTD) as a model, we combined two labeling techniques: site-specific incorporation of trifluoromethyl-phenylalanine (tfmF) at position Phe-28 and biosynthetic incorporation of 7-fluorotryptophan (7F-Trp) at all native tryptophan residues (Trp-14, Trp-70, Trp-94). High-efficiency labeling (>90%) was achieved in E. coli Rosetta DL3 using orthogonal tRNA/synthetase systems, confirmed by mass spectrometry and SDS-PAGE. ☐ Solution-state ¹⁹F NMR showed distinct and well-resolved signals for both tfmF (−14.6 ppm) and 7F-Trp (−52 to −57 ppm), indicating successful site-specific incorporation with minimal impact on protein structure. Moreover, the CF₃- tag provided approximately 9-fold greater signal sensitivity and can serve as an independent reporter on local structure in 19F NMR experiments. Crystallization and solid-state NMR data confirmed that the dual-labeled NNTD maintained its structural integrity, supporting its use for NMR experiments. ☐ This work lays the foundation for future NMR studies. The methodology is broadly applicable to other systems, offering a versatile framework for atomic-resolution structural biology in physiological contexts.University of Delaware, Department of Chemistry and BiochemistryM.S
Fate of novel brominated flame retardants in aquatic ecosystems: impact of chemical and substrate properties on partitioning
No full text"At the request of the author or degree granting institution, this graduate work is not available to view or purchase until March 10 2026"--ProQuest citation/abstract page.Chin, Yu-PingPersistent organic pollutants (POPs) are legacy manufactured organic chemicals classified as such due to their longevity and ubiquity in the environment, high bioaccumulation potential, and adverse effects at environmentally relevant concentrations. POPs include pesticides, industrial chemicals and byproducts, flame retardants, and plasticizers, among others. Novel brominated flame retardants (NBFRs) replaced the legacy brominated flame retardants (BFRs) that had been classified as POPS with the intention that these would be less harmful to humans and the natural environment. This dissertation investigates the fate of NBFRs in aquatic ecosystems by measuring their lipophilicity and partitioning to dissolved organic matter (DOM). It also explores the role of chemical and DOM properties in partitioning. ☐ First, octanol-water partition coefficients (KOW) of several NBFRs were measured by reversed-phase high performance liquid chromatography (HPLC) and estimated by computational models. We observed that computational log KOW estimates differed between themselves by 1–3 orders of magnitude. However, the reliability of the computational models could be evaluated by their ability to predict the log KOW of chemicals with similar structures to the NBFRs. The best-performing computational models predicted log KOW for the calibration chemicals close to their known values with root mean square error (RMSE) = 0.224, and for the NBFRs that were close to those we measured (RMSE = 0.334). Additionally, we confirmed previous research that found planar chemicals exhibited different partitioning behavior to the HPLC column than nonplanar chemicals. ☐ Second, we measured the dissolved organic carbon-water partition coefficients (KDOC) of five NBFRs by the solubility enhancement method to dissolved organic matter (DOM) isolated from diverse aquatic and terrestrial sources. We also measured the molecular weight of the DOM by high performance size exclusion chromatography. DOM performs an important role in the fate of organic contaminants in aquatic ecosystems via partitioning processes. DOM can increase chemical mobility, reduce their bioavailability and effective toxicity, and mediate chemical transformation by catalyzing abiotic and photolytic reactions. We observed that linear free energy relationships (LFERs) which predicted KDOC from chemical KOW significantly overpredicted partitioning of NBFRs to aquatic DOM, while poly-parameter (pp-) LFERs predicted KDOC to within an order of magnitude for four of the five NBFRs studied. We attribute the underestimation of the fifth NBFR to a lack of training set compounds in the pp-LFERs that possessed similar molecular structures and physicochemical properties. Additionally, the three nonplanar NBFRs did not partition most strongly to the DOM with the highest molecular weight and aromaticity, as would be expected. This was the first study to measure the KDOC of these NBFRs to natural aquatic DOM, and we observed partitioning behavior that was not easily explained using traditional LFER models. ☐ Third, we expanded our scope to investigate the partitioning behavior of neutral organic chemicals to natural aquatic DOM and Aldrich Humic Acid (AHA), a commercial DOM manufactured from low-grade coal and often used as a substitute for natural DOM in partitioning studies. We collected experimental KDOC data and assembled a database representing 1648 measurements and 319 structurally diverse neutral organic chemicals. LFERs were derived for AHA based on KOW and Abraham parameters with RMSE of 0.650 and 0.561, respectively. In contrast, no single “universal” LFER could predict partitioning to aquatic DOM. We observed that partitioning was dependent on chemical planarity and molar volume, regardless of measurement method or DOM composition. Planar chemical partitioning positively correlated with chemical molar volume, while nonplanar chemical partitioning similarly increased with molar volume until a breakpoint of 198 cm3/mol, after which KDOC did not or only increased slightly with molar volume. Incorporating planarity and molar volume into our pp-LFER allowed the partitioning of all chemicals to be predicted with significantly improved accuracy (RMSE = 0.604) as compared to traditional LFER models. We posit that our observations for the aquatic DOM dataset are due to the molecular weight and molar volume of the larger and sterically hindered nonplanar chemicals approaching that of the DOM itself. At that point, the binding would be better described as association between co-solutes, rather than partitioning. ☐ Overall, these studies provide insight into the fate of novel brominated flame retardants in aquatic ecosystems by measuring their octanol-water and dissolved organic carbon-water partition coefficients. These partition coefficients offer insight into whether or not these NBFRs should be classified as persistent organic pollutants, as high KOW indicates a high bioaccumulation potential, while high KDOC indicates that DOM may act as a “shield” and reduce the bioavailability of the freely dissolved NBFR to aquatic organisms. Finally, the examination of all available data on the partitioning of neutral organic chemicals to DOM revealed that partitioning was dependent on chemical planarity and molar volume. This new LFER may be used to incorporate DOM partitioning into computational models in order to more accurately predict the fate of NBFRs and other neutral organic chemicals in aquatic ecosystems and evaluate their potential as POPs.University of Delaware, Civil, Construction and Environmental EngineeringPh.D
The effect of parental self efficacy on outcomes for children with Autism Spectrum Disorder
No full textBarnes, Tia NaveleneThis study examined the relationship between parental self-efficacy (PSE), parent training involvement, and child behavioral outcomes following Applied Behavior Analysis (ABA) intervention for children with Autism Spectrum Disorder (ASD). While ABA is an evidence-based intervention often implemented by clinicians, increasing attention has been given to the role of caregiver beliefs and involvement in shaping treatment success. Guided by Bandura’s Social Cognitive Theory, this study assessed whether PSE or parent training frequency was more strongly associated with perceived child improvement. A total of 46 caregivers of children receiving ABA completed a one-time survey measuring self-efficacy, training participation, and their child’s functioning before and after intervention. Pearson and partial correlation analyses were used to test associations among variables. This study also examined the extent to which PSE served as a stronger predictor of child outcomes than parent involvement in training. Results showed a significant positive correlation between PSE and perceptions of post-intervention child outcomes, even after controlling for baseline functioning. In contrast, parent training involvement was not significantly associated with either PSE or child progress. These findings suggest that internal caregiver beliefs may play a more critical role in perceived treatment outcomes than participation metrics alone. Implications for ABA programs include greater emphasis on supporting parental confidence as a mechanism for promoting sustainable behavioral change.University of Delaware, Department of Human Development and Family SciencesM.S
Editorial Introduction to the ‘Bibliotoxicology’ Special Issue of Studies in Conservation
No full textThis is an Accepted Manuscript of an article published by Taylor & Francis in Studies in Conservation on 01/29/2025, available at: https://doi.org/10.1080/00393630.2025.2456899.
© 2025 Melissa Tedone.
This article will be embargoed until 07/29/2026.The term ‘bibliotoxicology’ was first used in 2020 to describe the Poison Book Project, which investigates arsenic and other heavy metals in nineteenth-century Euro-American bookbindings. The Bibliotoxicology Working Group (BibTox), which emerged from this work in 2022, brings together conservators, scientists, librarians, collection managers, book historians, and health and safety professionals. Currently made up of over 80 members from 45 institutions across eight countries, BibTox provides an ad-hoc, virtual discussion forum where researchers and professionals encountering a range of toxic materials in library collections can debate pressing safety and access concerns. BibTox aims to identify toxic substances in library and archives collections, establish safer management practices, and make reliable information broadly accessible
An investigation of HOX-regulatory mechanisms and their role in the stem cell origin of human colorectal cancer
No full textBoman, Bruce M.Homeobox (HOX) genes are a highly conserved subset of genes that encode transcription factors critical for SC function. Many HOX are also implicated in multiple cancers, including colorectal cancer (CRC). However, how HOX genes affect SC regulation and how HOX gene dysregulation contributes to CRC development is still understudied. Current research indicates that HOX expression is regulated by the WNT and retinoic acid (RA) signaling pathways, both of which are dysregulated in CRC. Goal: To determine how HOX gene regulation specifies differentiation of colonic SCs into specialized cell lineages in the colon and how dysregulation of HOX genes contributes to CRC development. Hypotheses: i) The different SC subtypes within the human colonic epithelium have distinct HOX gene expression signatures; ii) HOX gene expression is normally controlled by RA and WNT signaling in human colon, and aberrant WNT and RA signaling dysregulates HOX expression in CRC development. Results: Treatment of CRC cells with all-trans RA (ATRA): 1) Decreased proliferation and increased cellular differentiation, particularly along the neuroendocrine cell (NEC) lineage; 2). Significantly changed HOX gene expression. NanoString mRNA profiling shows that ATRA treatment of CRC cells increases HOXA3 & HOXA5 and decreases HOXA10, HOXB6 & HOXB9. NanoString profiling also shows that the HOXC6 and HOXA5 showed significant decreased expression in LGR5+ cells. Meanwhile, ALDH+ cells showed an increase in HOXA7 and HOXD10 and a decrease in expression of HOXB8 and HOXB13. Lastly, GLP2R+ neuroendocrine cells (NECs) show significant increased expression of HOXB6, HOXA6, and HOXC9 and decreased expression of HOXA1. Moreover, comparing these mRNA expression patterns to the TCGA mRNA expression database identified a HOX expression pattern that predicts poor CRC survival. Specifically, an increase in HOXB4, HOXC6, HOXC9, HOXC11, HOXC13, and HOXD9 and a decrease of HOXA13 and HOXB13 indicate poorer CRC survival. Conclusion: Defining how HOX gene expression changes in response to ATRA treatment in comparison to the HOX gene signatures of different colonic cell lineages shows how HOX gene expression plays a role in differentiation of SCs along the NEC lineage and how aberrant WNT and RA signaling dysregulates HOX expression in CRC development.University of Delaware, Department of Biological SciencesPh.D
Creation of a 22 Year Tax Parcel Time Series
No full textMotivation for development of the time series:
•Model where development is likely to occur to support land use and infrastructure planning.
•Allocate county-based housing projections as provided by the Delaware Population Consortium to smaller areas withing the counties.
•The ability to examine policy “what-ifs” at the more detailed level of tax parcels is increasingly needed for sub-area or community transportation plans, and various research.
•Generally, map where development has occurred in the last 20 years and develop a method of managing an array of tax parcel data for further research and policy considerations.DelDOT and the Delaware Center for Transportatio