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The myth of getting carried away: relationships between rape myth acceptance and disclosure of sexual violence among victims/survivors in university
No full textThis article was originally published in Critical Public Health. The version of record is available at: https://doi.org/10.1080/09581596.2025.2522965
© 2025 the author(s). Published by informa UK limited, trading as Taylor & Francis Group
This is an Open access article distributed under the terms of the Creative Commons attribution-Non Commercial license (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. the terms on which this article has been published allow the posting of the accepted Manuscript in a repository by the author(s) or with their consent.Objective
To examine the relationships between rape myth acceptance among victims/survivors of sexual violence and their disclosure behaviors, to inform more effective sexual violence prevention and support for victim/survivor public health strategies.
Participants
Undergraduate students (n = 342) enrolled at a university, aged 18 or older (m = 21.12, SD = 4.12), and who have experienced sexual violence.
Methods
An online survey was administered in 2020 at a racially and ethnically diverse public university. ANOVA tests compared rape myth acceptance scores across social groups, and binary logistic regressions examined the association between rape myth acceptance and disclosure of sexual assault.
Results
Regression results revealed that among college students who had experienced some form of sexual violence, there was no significant relationship between total rape myth acceptance scores and sexual assault disclosure. However, one rape myth was significantly associated with disclosure behavior: Guys don’t usually intend to force sex on a girl, but sometimes they get too sexually carried away.
Conclusions
Findings may enhance sexual assault prevention training in high schools and colleges/universities, as well as public health campaigns aimed at improving social support for victims/survivors by targeting entrenched beliefs about rape myths that act as barriers to disclosure among victims/survivors.The authors did not receive any funding in preparing this manuscript
Topology-informed robust optimization for out-of-distribution generalization
No full textPeng, XiMachine learning models have demonstrated remarkable success across numerous domains, but their performance often deteriorates significantly when deployed on data distributions that differ from those encountered during training. This dissertation addresses the critical challenge of out-of-distribution (OoD) generalization through four complementary approaches. First, we introduce Topology-informed Robust Optimization (TRO) for single expert models, a method that leverages the topological structure of data distributions to construct realistic uncertainty sets and improve OoD resilience. Second, we extend this approach to mixture-of-experts models by developing a novel ensemble pruning technique that adaptively selects complementary models based on a learned ensemble topology graph. Third, for the challenging scenario of single domain generalization, we propose an adversarial domain augmentation framework that relaxes worst-case constraints to generate diverse "fictitious" domains while maintaining semantic consistency. Finally, we address the crucial need for uncertainty quantification in OoD scenarios by developing a Bayesian meta-learning approach that applies uncertainty-guided perturbations to both feature and label spaces. Through extensive theoretical analysis and empirical validation across diverse tasks including classification, regression, semantic segmentation, and speech recognition, we demonstrate that incorporating structural information about distribution relationships substantially enhances generalization to unseen distributions. This research contributes novel optimization methods, theoretical insights, and practical techniques to improve the robustness and reliability of machine learning models deployed in real-world environments where distribution shifts are inevitable.University of Delaware, Department of Computer and Information SciencesPh.D
Characterizing the Effect of Poly(ethylene glycol) Concentration and Surface Modifications on Doxorubicin-Loaded Polymer Nanoparticles
No full textenterTriple-negative breast cancer (TNBC) is an extremely aggressive subtype of
breast cancer that accounts for around 20% of all breast cancer diagnoses [1], [2].
Unlike other subtypes of breast cancer, TNBC lacks expression of the three common
receptors of estrogen receptor (ER), progestogen receptor (PR), and human epidermal
growth factor receptor 2 (HER2), making it difficult to treat with current interventions
[3]. The lack of molecular targets combined with TNBC’s aggressive nature leads to
poor prognosis with a ~40% mortality rate within 5 years of diagnosis [4]. Due to this
poor prognosis, it is important to develop novel methods to treat TNBC.
Nanoparticles (NPs) are versatile drug-delivery vessels with highly tunable
characteristics making them adaptable for a variety of therapeutic applications [5].
Poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PEG-PLGA) NPs have favorable
characteristics such as biodegradability and biocompatibility, and the individual
components of PLGA and PEG are both FDA approved polymers [6], [7]. These NPs
have the ability to encapsulate and deliver Doxorubicin, a chemotherapeutic, which
can enhance the drugs’ effectiveness and safety in treating solid tumor cancers by
improving the relative amount of the payload that reaches tumors versus other tissues
[7]. NPs also prevent the adverse off target effects normally characteristic of
chemotherapies. To advance the use of PEG-PLGA NPs in cancer nanomedicine, this
thesis investigates how PEG concentration influences the characteristics of PEG PLGA NPs as well as how surface modifications affect the NPs’ characteristics.
PEG-PLGA NPs are prepared by mixing different combinations of PEG-PLGA
with PLGA through a single emulsion oil-in-water method. In this thesis, three ratios
of PEG-PLGA to PLGA (25% PEG-PLGA/75% PLGA, 50% PEG-PLGA/50%
PLGA, 75% PEG-PLGA/25% PLGA) were used to produce NPs containing
doxorubicin-HCl (DOX), a chemotherapy drug used to treat TNBC and other forms of
cancer. Each formulation was characterized for its’ initial DOX loading, stability in
storage conditions, and DOX release kinetics in physiologic conditions. Through these
studies, it was identified that the 25/75 PEG-PLGA/PLGA formulation shows optimal
characteristics such as remaining stable in size and charge in storage conditions,
having a high initial DOX loading, superior DOX retention in storage conditions, and
favorable release kinetics in physiologic conditions. Based on these favorable
characteristics, the 25/75 formulation was selected for additional experiments to study
the influence of surface modifications on NP characteristics. NPs were coated with
either Frizzled7 (FZD7) antibodies or TNBC cell-derived plasma membranes, as both
of these coatings have been shown to enable TNBC cell targeting of NPs in prior
research. In this thesis, it was determined that both FZD7 antibody-coated NPs and
TNBC cell membrane-coated NPs showed similar DOX release kinetics to the
unmodified core, although the initial DOX loading in the NPs was reduced compared
to the uncoated NPs. These findings suggest that further optimization of the coating
process may be needed to ensure minimal loss of cargo during NP surface
functionalization.
Collectively, this thesis shows that a lower ratio of PEG-PLGA to PLGA is
preferable when developing NPs for hydrophobic drug delivery and that there is some
loss in cargo loading during the surface functionalization of these NPs. These findings
are important for the future development of NPs with improved characteristics to
enhance cancer treatment outcomes.ente
Time Enabled Traffic Data
No full textTraffic data as available in Delaware includes periodic counts, traffic studies, and a wide range of sensor technology counts. This data is the volume, speed, or other characteristics of a particular turning movement at a particular time on a particular date. Measurements are time dependent, and data can be queried for a particular minute or hour or day or month, or season. This document discusses how time dependent traffic data can be effectively prepared, stored, displayed, and analyzed within geographic information systems (GIS). Research to prepare the measurement tables, assign time, and visualize the data are discussed. The processing of the DelDOT TMC Device data is the subject of the work, but the approach would be similar for various traffic count data. Preparation of the data is toward defining typical flows by time of day, day of week, and season
Signal processing on Cayley and nearly Cayley graphs
No full textGhandehari, MahyaGraph Signal Processing (GSP) is a dynamic and quickly growing field of study that is motivated by the continued increase in network-based data in today's world and the need for tools to analyze such data. In this dissertation, we address multiple questions arising in the mathematics of GSP and related areas, including Graph Limit Theory and Graphon Signal Processing. We focus on developing techniques for Cayley graphs, which are algebraically-defined and highly symmetric in nature, making them a rich class of graphs for applications. For instance, Cayley graphs appear in contexts such as ranked-choice voting, RNA folding, and small-world networks. This leads to the need for the further advancement of graph signal processing techniques for Cayley graphs. ☐ An important component in the design of GSP techniques is the spectral decomposition of graph adjacency matrices. The main tool in GSP, the graph Fourier transform, relies on an appropriate choice of eigenbasis for the asociated graph matrix. In order to better capture the symmetries in a Cayley graph, we present a spectral decomposition of the adjacency matrix of a weighted Cayley graph based on the representation theory of the underlying group. This representation-theoretic approach offers a significant benefit in that it provides a block-diagonalization of the graph Laplacian matrix resulting in much smaller block sizes than the original matrix. Moreover, the same block-diagonalizing matrix works for any Cayley graph over a given group. Based on this spectral decomposition, we give an explicit recipe for constructing the eigenvalues and eigenvectors of the graph. This leads us to a preferred choice of eigenbasis for the graph Fourier transform when applied to weighted Cayley graphs. ☐ Utilizing these eigenbases, we construct a class of frames for signal processing on weighted Cayley graphs called Frobenius-Schur and Cayley frames. Frames are over-complete spanning sets that are often a more advantageous choice for representing a signal rather than an orthonormal basis, as frames can provide redundancy and allow for the reconstruction of a signal, even if some of the signal information is lost in the process of transmission. We provide a characterization and detailed description for the construction of the Frobenius-Schur and Cayley frames. These frames are especially promising as a tool for GSP on Cayley graphs as they have been shown to provide meaningful interpretation of ranked voting data. ☐ We also address questions in the area of Graphon Signal Processing, which unifies Graph Limit Theory and Graph Signal Processing to provide an instance-independent framework for signal processing on graphs. Given a sequence of graphs of growing size, one possible limiting object is a symmetric, measurable function on [0,1]2, called a graphon. In order to analyze data on the sequence of graphs, one would have to compute a spectral decomposition of the associated matrix for each individual graph. Graph Limit Theory allows us to instead consider the limiting graphon and compute a spectral decomposition only once in order to analyze data on graphs sampled from the graphon. We present examples of Graphon Signal Processing on Cayley graphons, which are the appropriate analogue of Cayley graphs in the graphon setting. Moreover, we lay the foundation for the development of frames on Cayley graphons. ☐ So far, Graphon Signal Processing has only been developed in the context of dense graph sequences. Relying on the Lp theory for sparse graph sequences, we lay the foundation for the development of Graphon Signal Processing in the sparse setting. We present multiple results that, in the sparse setting, relate cut-norm convergence and p → q-norm convergence of graphons as well as establishing convergence for eigenfunctions of the graphon integral operator. These propositions bring us one step closer to defining the graphon Fourier transform for Lp graphons.University of Delaware, Department of Mathematical SciencesPh.D
Health Outcomes Associated with Community Senior Center Fitness Classes: Influence of Activity Type and Baseline Physical Activity Level
No full text© 2025 by the author. This is an open access article distributed under the conditions of the Creative Commons by Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium or format,
provided the original work is correctly cited.
This article was originally published in OBM Geriatrics.. The version of record is available at: doi:10.21926/obm.geriatr.2503326Senior centers serve as community anchors for the approximately 57.8 million older adults in the U.S., offering a range of health promotion programs, including exercise classes. This study examined how the type of exercise programs at senior centers influences older adults’ health (mental, physical, and quality of life) and how baseline physical activity levels may influence these changes as part of a statewide health promotion program evaluation in senior centers in Delaware. The exercise programs offered were based on each senior center’s needs, increasing the feasibility and accessibility of these classes. Data was categorized by type of exercise class attended, “aerobic” (n = 63), “muscular strengthening” (n = 44), “balance and flexibility” (n = 20), or mixed class type participation (n = 13). Participants (n = 141; age: 74.4 ± 8.1 yrs; 87.1% female) attended exercise classes at their respective senior centers across the state of Delaware. Participants completed pre-and post-program assessments of perceived mental and physical health, quality of life, and physical activity level. Participants’ baseline physical activity levels were “Inactive” (n = 54), “Moderately Active” (n = 24), or “Active” (n = 45). A linear regression model was used to examine whether health outcomes were predicted by the type of exercise class and baseline physical activity level. Class type, baseline physical activity levels, age, and sex did not significantly predict post-program perceived physical and mental health or quality of life. However, pre-program scores of physical health, mental health, and quality of life significantly predicted their associated post-program health outcome scores. Overall, regardless of exercise class type, age, sex, or pre-participation physical activity, senior center exercise classes positively impact mental health and quality of life amongst older adults. These findings indicate that senior center exercise programs may be a cost-effective public health strategy to support healthy aging, by improving older adults’ mental health and quality of life
Fecal microbiota transplantation modulates jejunal host-microbiota interface in weanling piglets
No full textThis article was originally published in Microbiome. The version of record is available at: https://doi.org/10.1186/s40168-025-02042-9.
© The Author(s) 2025.
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.Background
Weaning-associated enteric diseases are a major concern in the swine industry. This study investigates the effects of fecal microbiota transplantation (FMT) on the jejunum of weanling piglets, a segment of bowel less studied in terms of microbiomic changes despite its primary involvement in major post-weaning enteric diseases, including postweaning diarrhea (PWD). Thirty-two 3-week-old piglets were divided equally into two groups: Control and FMT. The FMT group received fecal microbiota preparation from 3-month-old healthy pigs on the 1st and 3rd day after weaning. Half of each group was inoculated with an enterotoxigenic E. coli (ETEC) isolate 10 days post-FMT. Piglets were euthanized in the third week (14th and 18th days post-FMT) after weaning to collect intestinal tissues and contents for microbiomic, metabolomic, and transcriptomic analyses.
Results
The jejunal microbiota showed a significant increase in alpha diversity in the third week post-FMT compared with the ileum and colon. FMT significantly enriched the jejunal microbiota composition, while multiple bacterial genera were specifically lacking in control weanling piglets. FMT was strongly associated with the enrichment of the genus Pseudoscardovia of the Bifidobacteriaceae family, which was found lacking in the jejunum of weanling control piglets and inversely associated with the abundance of the genus Bifidobacterium within the same family. Other genera associated with FMT included Solobacterium, Shuttleworthia, and Pseudoraminibacter, whereas bacteria such as Erysipelotrichaceae and Acidaminococcus were identified as most abundant in the control piglets. Metabolomic analysis revealed a significant modulatory effect of FMT on carbohydrate, amino acid, nucleotide, vitamin, and xenobiotic metabolisms, suggesting improved nutrient utilization. Transcriptomic analyses further confirmed the regulatory effects of FMT on gene expression associated with immune, metabolic, barrier, and neuroendocrine functions. Prior FMT treatment in the context of ETEC infection indicated a potential protective role, as evidenced by a significant shift in microbial diversity and metabolomic compositions and decreased diarrhea severity even though no effect on pathogen shedding was evident.
Conclusions
This study underscores the promise of FMT in enhancing jejunal health. In addition, the results suggest that FMT could be considered a potential strategy to address conditions associated with small intestinal dysbiosis in swine and other monogastric species with similar gut anatomy and physiology, such as humans.
Video Abstract available at: https://doi.org/10.1186/s40168-025-02042-9This project was supported by Agriculture and Food Research Initiative competitive grant no. 2022-67015-40720 from the USDA National Institute of Food and Agriculture and grant no. 19-216 IPPA from the Iowa Pork Producers Association
Iron-oxidizing microorganisms: genes, mechanisms, and environmental impact
No full textChan, Clara S.Iron is the fourth most abundant element in Earth’s crust and plays a crucial role in the planet’s biogeochemical cycles. Freshwater iron-oxidizing bacteria (FeOB) can catalyze and accelerate iron oxidation thereby mediating, and potentially driving, iron cycling in diverse environments. However, without functional marker genes of iron oxidation, we are unable to fully assess FeOB contributions to environmental iron oxidation. This dissertation addresses that knowledge gap by identifying novel genes and mechanisms with a potential role in Fe oxidation, testing the expression of novel genes and known Fe oxidases in a lab isolate, and investigating the expression of those genes in the environment. It also explores the environmental impact of FeOB, examining how their Fe-cycling metabolisms can impact C and N cycling in wetland environments. ☐ We need a better accounting of iron oxidation genes and mechanisms before we can detect and quantify biotic iron oxidation in the environment. This is especially true for iron oxidation in freshwater environments, for which there are few isolates. Of the isolates we do have, many are difficult to culture, growing slowly and to low cell density, limiting our ability to investigate them. In the first study, we leveraged bioinformatics tools to do a pangenome analysis of the Gallionellaceae, a family of freshwater bacteria known for its iron-oxidizing members. We first resolved the Gallionellaceae phylogeny, identifying four main genera. We then compared genomes of the three iron-oxidizing genera (Gallionella, Sideroxydans, and Ferriphaselus) against genomes from a single nitrite oxidizing genus (Candidatus Nitrotoga) to learn about the genes and mechanisms unique to iron oxidation. Cyc2 and MtoA iron oxidase genes were widely distributed, yet specific to the FeOB. Further analysis of the FeOB genomes identified additional shared metabolic traits and genes that may encode adaptations for Fe oxidation and extracellular electron uptake (EEU). This includes genes that may encode iron oxidation pathway components (ircABCD), and genes for multiheme c-type cytochromes (MHCs) that could form porin-cytochrome complexes to oxidize Fe or transport electrons throughout a range of redox potentials. Overall, the Gallionellaceae pangenome provides an in-depth look at the metabolic flexibility and genetic potential of a family of FeOB. It suggests Gallionella, Sideroxydans, and Ferriphaselus have a range of adaptations that contribute to their success. It also identifies putative genes and mechanisms of Fe oxidation for additional study. ☐ Determining whether a gene’s expression is specific to a single activity is a key step in evaluating its potential as a functional marker gene. However, evidence of gene expression in FeOB remains limited, partly due to the challenges of culturing sufficient biomass and iron’s interference with DNA and RNA extraction and sequencing. In this study, we analyzed the gene expression of Sideroxydans sp. CL21 to investigate its iron oxidation genes and pathways. CL21 is a Gallionellaceae FeOB capable of growth on both organic and inorganic substrates, making it the only organotrophic Gallionellaceae FeOB isolate to date. It contains genes for both known iron oxidases (cyc2, mtoA) and several additional genes of interest identified in the Gallionellaceae pangenome (ircABCD, PCC3). To overcome the challenges of low biomass and iron interference, we grew CL21 on lactate instead of Fe(II) and used iron oxidation assays to determine when cells were able to oxidize iron. These iron assays revealed lactate-grown cells could oxidize Fe(II) during late-log phase (Day 14), but not at mid-log phase (Day 6). This allowed us to compare gene expression between iron-oxidizing (late-log) and non-iron-oxidizing (mid-log) cells. We found iron oxidase genes (cyc2, mtoA) were highly expressed at both time points, and did not correspond to iron oxidation activity. This supports growing evidence that cyc2 expression is often high and is not (by itself) a sign of iron oxidation activity. In contrast, several genes encoding periplasmic and inner membrane cytochromes (mtoD, cymA/imoA, ircABCD) were significantly upregulated at the late-log (iron-oxidizing) timepoint. These expression patterns suggest CL21’s iron oxidation pathway may be regulated at different stages, with genes encoding periplasmic and inner membrane electron carriers (mtoD, cymA/imoA, ircABCD) upregulated at times of iron oxidation activity. Thus, genes like ircABCD may be prospective indicators of iron oxidation activity in the environment. ☐ Minerotrophic wetlands (fens) are home to diverse microbial communities that drive biogeochemical cycling, but the understanding of Fe-cycling organisms in these environments is limited. In particular, the taxonomic and metabolic diversity of these iron-cycling communities is not well understood. In this third study, we used our insights into the genes and mechanisms of Fe oxidation along with knowledge of Fe reduction and N-cycling genes to assess the microbial community of the Schlöppnerbrunnen fen. We found that nearly half the reconstructed community had a potential for Fe-cycling at all depths (5-30 cm). Fe oxidizers included many Gallionellaceae from known (Gallionella, Sideroxydans) and novel (RI-121, CAITJF01) genera. Surprisingly, an abundant and active Bathyarchaeia (FEN-987) also encoded and expressed a Cluster 1 cyc2. Fen FeRB were also diverse. Known taxa, like Geobacter, made up a small percent of the community while members of the Acidobacteriae with iron reduction genes appeared more abundant. By analyzing these FeOB and FeRB in conjunction with N-cycling, we found multiple organisms with a potential for NDFO or Feammox in the fen. This suggests iron cyclers may be able to directly influence N transformations. Overall, this study identified a diverse microbial community with a high potential for Fe-cycling. It shows that not only do wetlands have a high capacity for biogeochemical Fe- and N-cycling, but those processes may be linked though NDFO or Feammox metabolisms in various organisms making the continued study of Fe-cyclers key to understanding biotic drivers of N detoxification and GHG production. ☐ Overall, this dissertation contributes to the development of functional gene markers for Fe oxidation by leveraging -omics and bioinformatics analyses of both lab isolates and environmental datasets. It identifies key genes and mechanisms for further investigation, while also advancing our understanding of the environmental role of FeOB and their involvement in coupling the Fe, C, and N cycles.Ph.D.University of Delaware, Microbiology Graduate Progra
Using trust generators as a framework for building trust at Delaware Technical Community College
No full textKarchmer-Klein, RachelResearch indicates that trust is a foundation of student success. It is therefore crucial for instructors to use trust building strategies to promote student retention and success. However, anecdotal and institutional evidence indicates that instructors at Delaware Tech do not feel equipped with communication strategies to build rapport and connect with students. To address that challenge, I pursued the following improvement goal: to design professional development sessions for Delaware Tech instructors on strategies to build rapport and connect to students through Hammond’s (2015) trust generators (concern, selective vulnerability, familiarity, similarity of interests, and competence) as the foundation for a culturally responsive pedagogical (CRP) perspective. ☐ My first improvement strategy consisted of identifying and compiling research through a literature review and annotated table to better understand communication and trust building at the community college level. The research showed that getting to know students and building empathy enhances student success. Furthermore, a survey assessing Delaware Tech instructor self-perceptions of culturally responsive practice implementation was sent to all Delaware Tech full-time faculty. Survey results indicated that Delaware Tech instructors felt most concerned about culturally responsive practices that focused on awareness of students’ home lives and cultures. ☐ Based on those results, professional development was needed to provide instructors strategies on getting to know students and building learning partnerships through trust. Therefore, I designed and implemented professional learning focused on Hammond’s (2015) trust generators. First, I designed a Google Site compiling multimodal resources on CRP and trust-building practices. Next, I designed and implemented a professional development seminar on the importance of trust building and strategies to implement Hammond’s (2015) trust generators. Next, I built a curriculum plan and course design matrix for a micro-credential course on learning partnerships and trust generators to be offered through Delaware Tech’s Center for Creative Instruction and Technology. ☐ The final improvement strategy featured an evaluation survey of professional learning. The survey results from the professional development seminar indicated a positive experience, and further professional development offerings based on this research were requested by leadership. ☐ Future steps in providing strategies for instructors on trust building should include more research on the connection between communication and rapport building, in-depth conversations with instructors (including adjunct instructors) about areas of needed support, leveraging Delaware Tech’s Professional Learning Community (PLC) groups for ongoing professional learning, and implementation of a micro-credential course on trust generators.University of Delaware, School of EducationD.Ed