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Time course of person perception and evaluation as a function of competency status and human-like characteristics
No full textKubota, Jennifer T.Cloutier, JasminThis research examined how competency status influences attention and evaluative processing of human agents (i.e., human faces) and non-human agents (i.e., AI faces and AI symbols). Specifically, we focused on the N170 and the P300 responses, given their associations with early face processing and motivational saliency, respectively. 43 self-identified male participants completed an impression formation task while we recorded electroencephalogram (EEG). Participants were instructed to form impressions of interaction partners that varied in human-like characteristics (i.e., human faces, AI human faces, and AI symbols) and competency status. Specifically, participants were presented with images of each target and their corresponding competency status, which was denoted by a set of stars—either high competency status (8-10 stars) or low competency status (1-3 stars). Impressions of these faces were performed in a context of ostensible future cooperative interactions with the partners. The results showed distinct ERP patterns when perceiving human and AI agents varying in competency status. ERP results revealed an interaction between human-like characteristics and competency status for N170 amplitudes, such that greater N170 amplitudes were observed in response to high-status AI faces and AI symbols compared to high-status human faces. Moreover, greater P300 amplitudes were observed in response to a) AI faces relative to human faces and AI symbols and b) high-status compared to low-status partners. This research has implications for how competency status shapes attention and evaluative processes deployed towards human and AI agents.University of Delaware, Department of Psychological and Brain SciencesM.S
Exploring advanced binder and electrolyte system for high-performance lithium-sulfur batteries
No full textYao, Koffi, P. C.Lithium-Sulfur (Li-S) batteries have received significant attention as promising alternative to lithium-ion batteries due to their high theoretical specific capacity (1675 mAh·g-1Sulfur) and energy density (2500 Wh·kg-1). However, there are fundamental challenges impeding their commercialization. Notorious among those challenges is the “polysulfide shuttle” consisting of the dissolution into the electrolyte and subsequent crossover to the negative electrode of long-chain, high-order sulfides (LiPSs). The mitigation of this polysulfide shuttle through electrode engineering and electrolyte design is key to realizing durable Li-S cells. In this thesis, successive studies are conducted with the goal of contributing novel insights and approaches for overcoming this fundamental barrier. ☐ The lesser-known role of the conventional binder (polyvinylidene fluoride, PVDF) in the instability and degradation of sulfur electrodes in Li-S batteries, as well as potential strategies for its mitigation were investigated. In addition, the influence of various electrolyte systems on the reaction pathways governing polysulfide dissolution and migration has been systematically investigated. Based on these findings, a biphase electrolyte system is proposed to eliminate LiPSs-shuttle and enhance the electrochemical stability of Li-S batteries. ☐ The first study investigates a critical failure pathway in PVDF-based sulfur electrodes that have not been widely recognized. It is revealed that 1,3-dioxolane, a common solvent in Li-S electrolytes, falls within the Hansen solubility sphere of PVDF, leading to the gradual dissolution of PVDF. Consequently, this dissolution compromises electrode structural integrity, increases electronic impedance, and causes rapid loss of active sulfur via the LiPS shuttle. To address this issue, a novel double crosslinked starch (DCS) binder was synthesized via two cross-linking reactions and contrasted against PVDF to mechanistically highlight the impact of such PVDF-dissolution. Compared to PVDF, DCS remains insoluble in the electrolyte, preserving the structural integrity of the sulfur electrode and exhibiting 2.5 times lower impedance after 200 cycles. Operando Raman spectroscopy, visual cell observations, and ex-situ UV-vis analysis confirmed superior polysulfide retention of the DCS-bound electrode. It achieved a discharge capacity of 522 mAh·gs-1 at 0.1 C rate after 200 cycles, representing a capacity fade of 0.14% per cycle beyond the initial 20 cycles. Under similar conditions, PVDF-bound sulfur electrode delivered a lower discharge capacity of 434 mAh· gs-1, and a higher decay rate of 0.24% per cycle after stabilization. This study highlights the limitations of PVDF binder in S-electrodes and investigates an alternative candidate (DCS) binder, which improves the structural integrity of S-electrodes and demonstrates superior electrochemical performance. ☐ The second study explores the influence of different electrolyte paradigms on the dissolution and diffusion of LiPSs in Li-S batteries. These electrolytes are categorized into fully solvating electrolytes (FSEs) and sparingly solvating electrolytes (SSEs). A comprehensive literature meta-analysis reveals that the most significant benefit of sparingly solvating electrolytes in Li-S batteries is the improvement in coulombic efficiency. Optical operando Li-S cell and ex situ UV-vis analysis were used to investigate polysulfide speciation in FSE and SSE. Experimental optical imaging enables real-time visualization of polysulfide dynamics, while UV-vis spectroscopy facilitates the identification of soluble polysulfide species within the electrolyte at the completion of cycling. Optical imaging and UV-vis characterization reveal that an increase in lithium salt concentration in the electrolyte, which renders it more sparingly solvating, induces a shift toward the formation of shorter-chain polysulfides. The transition to shorter-chain polysulfides indicates a reduction in the polysulfide species participating in LiPS-shuttle, thereby enhancing the coulombic efficiency. Under similar conditions, FSE follows the well-known reaction pathway, where sulfur initially converts to long-chain LiPS before transitioning to short-chain LiPS. This study demonstrates that SSEs minimize LiPS-shuttle, which is a major contributor to capacity fading and poor coulombic efficiency in FSEs. ☐ The final study proposes a novel biphase electrolyte based on the phase separation between solvents with different polarity. The biphase electrolyte decouples the cathode electrolyte (catholyte) from the anode electrolyte (anolyte), forming a selective interfacial membrane between them. This membrane blocks LiPS crossover from the catholyte to the anolyte, while allowing Li+ ion transport. Hansen Solubility Parameters of solvents are used to identify non-aqueous solvent pairs that exhibit and maintain phase separation during the cycling of Li-S batteries at room temperature. Candidate solvent pairs exhibited significant differences in their partial polarities. The high-polar solvent was used to prepare the catholyte due to its strong LiPS solvation power, while the low-polar solvent was used to prepare the anolyte. As a proof-of-concept, cycling an operando visual cell with biphase electrolyte confirms that the selective interfacial membrane effectively confines LiPSs to the catholyte. Electrochemical cycling further demonstrates that the biphase electrolyte maintains a more stable coulombic efficiency after the initial cycles compared to conventional electrolyte, indicating effective suppression of LiPS-shuttle. This study presents a new pathway for advancing the development of high-performance Li-S batteries. ☐ Together, these studies highlight the importance of developing alternative binders for S-electrodes, elucidate the reaction mechanisms governing polysulfide speciation in an electrolyte that reduces LiPS-shuttle, and propose a novel electrolyte that effectively suppresses LiPS-shuttle.University of Delaware, Department of Mechanical EngineeringPh.D
Infant diet interventions: effects on the gastrointestinal microbiota
No full text"At the request of the author or degree granting institution, this graduate work is not available to view or purchase until April 01 2026"--ProQuest citation/abstract page.Trabulsi, Jillian C.Early diet shapes the function, composition, and diversity of bacterial communities of the gastrointestinal (gut) microbiome. In the context of the liquid diet of infancy, pre-, pro-, and synbiotics have been added to infant formula in an effort to more closely resemble human milk (HM) and its beneficial health properties. With the introduction of solid foods, commonly known as weaning, there is a paucity of literature regarding the impact of individual first foods on the gut microbiota. To this end, the objectives of this dissertation were to: 1) synthesize the literature surrounding the effects of prebiotics, probiotics, and synbiotics on the infant gut microbiome and other health outcomes; 2) evaluate the feasibility of a short-term vegetable feeding intervention on the infant gut microbiota and microRNA (miRNA) expression; 3) evaluate the effect of different first food types (i.e., grain, meat, vegetable, and fruit) on the gut microbiota of exclusively HM fed infants. ☐ To address the first objective, a systematic review was conducted to evaluate the efficacy of pre-, pro-, and synbiotics in infant formula; 32 randomized, controlled trials (RCTs) were identified for inclusion. Among them, the methods utilized to measure the gut microbiota varied (e.g., colony plating, fluorescence in situ hybridization, quantitative polymerase chain reaction, 16S sequencing). The totality of the evidence revealed a consistent trend wherein Bifidobacterium levels increased with supplementation of pre- and synbiotics, but not pro-biotics. Pro- and synbiotic supplementation generally led to increased levels of the bacterial strain supplemented in the formula. Fecal pH was lower and stool consistency was softer with the addition of certain pre- and synbiotics. Further studies of pro- and synbiotic supplementation, utilizing advanced sequencing methodologies for a more comprehensive analysis, are warranted. ☐ For the second objective, a feasibility study of healthy infants (n=11) was conducted to evaluate the relationships among vegetable consumption, gut microbiota, and miRNA expression. Infants were randomized to one of three arms: control, broccoli, or carrot. The control group maintained their liquid milk diet only, while the other groups consumed broccoli or carrot purees on days 1-3 in addition to their liquid milk diet. Stool samples were collected on days 0, 2, 4, and 6; genomic DNA and total RNA were extracted from stool samples to measure microbiota and miRNA outcomes. Compared to control, a trend towards a decrease in alpha diversity (Shannon index) was observed in the carrot group on days 2 and 4 and beta diversity (weighted Unifrac) differed between the carrot and broccoli groups. Streptococcus was increased at day 4 in the carrot compared to control group. For the miRNA, a decrease in expression of miR-217 and miR-590-5p was observed in both the broccoli and carrot groups compared to control, whereas an increase in eight and two different miRNAs were observed in carrot and broccoli groups, respectively. This study demonstrated the feasibility for short-term feeding interventions to investigate effects on and the relationship between microbial communities and miRNA expression. ☐ To address the third objective, a pilot RCT was conducted to investigate the effect of common first food types on the gut microbiome. Vaginally delivered, exclusively HM fed infants (n=41) that had not yet begun consuming solid foods were randomized to one of four groups: oatmeal cereal, beef, carrot, or prune, and were fed their randomized food 3x/day, 2oz each feeding, along with HM, for one week, followed by oatmeal cereal and HM for a second week. Stool samples were collected and diet intake was recorded. Genomic DNA was extracted from stool samples and the 16S gene (V1-V9 regions) was sequenced. This study is currently ongoing, with analyses conducted exclusively on participants completed to date (n=22). Focusing on the effects of time only, as expected, microbial diversity increased, and the relative abundance of bacterial taxa (genus level) also changed over time. Specific to the feeding intervention, preliminary results suggest that the introduction of meat resulted in a microbial profile characterized by lower alpha diversity in comparison to feeding cereal, fruit, or vegetables, and these latter three groups exhibited microbial profiles of equal alpha diversity. In these preliminary data, there were no differences by feeding group for beta diversity. Moreover, the feeding of prune appears to result in an increase in Klebsiella compared to feeding beef and carrot. Upon ceasing feeding of the first food, feeding oatmeal cereal further increased alpha diversity in infants previously fed meat as their first food. Beta diversity indices indicated a difference between the continuation of oatmeal cereal compared to the introduction of oatmeal cereal after prune. However, no differences were found in relative abundance. These analyses will be repeated, in a blinded manner, with the completion of the RCT to elucidate differential effects of first foods on the gut microbiome and contribute to the literature on optimal first foods. The value of this research may provide justification for the consideration of gut health in addition to nutritional requirements as part of infant feeding recommendations. ☐ In summary, variations in both liquid and complementary diet composition result in distinct impacts on the gut microbiota which in turn may influence host health. The results of this research establish the effects of short-term feeding interventions on gut microbial composition and emphasize the importance of the gut microbial profile as a consideration when formulating first food recommendations for infants.University of Delaware, Department of Health Behavior and Nutrition SciencesPh.D
"It's like saying I'm not smart enough or good enough": mental illness self-labeling and self-stigma in graduate school
No full textVican, ShawnaGraduate students experience high rates of mental illness, often struggling with anxiety, depression, or other conditions while navigating demanding programs, high-pressure environments, and complex institutional systems. Many face burnout and imposter syndrome, and accessing help or accommodations often requires disclosure of a diagnosis or symptoms. This study explores how graduate students navigate the process of self-labeling as mentally ill, focusing on the role of stigma within academia. The research aimed to better understand how students interpret their mental health experiences, whether they self-label, disclose, and how stigma influences these decisions. Guided by Thoits’ (1985) self-labeling theory and an intersectional stigma framework (Berger, 2004), this mixed methods study included a survey of 500 graduate students across the United States and follow-up interviews with 20 participants. Quantitative findings show that self-labeling, stigma, and disclosure are shaped by both individual and environmental factors, with characteristics such as LGBTQIA+ identity, age, race, international student status, and field of study significantly influencing internalized stigma, anticipated discrimination, and willingness to disclose - particularly to advisors or mentors. Social context also played a key role; knowing peers who had disclosed and having prior treatment experiences increased the likelihood of disclosure, highlighting the importance of perceived safety and normalization. Qualitative analyses further revealed that self-labeling is a complex process influenced by factors such as stigma, understanding of identity, and symptom severity. These findings underscore the importance of institutional policies that are culturally competent, equity-driven, and attentive to intersectionality and power dynamics that shape graduate students’ mental health experiences. ☐ Keywords: Mental illness, Stigma, Graduate Students, Mental health, Self-labeling theory, Intersectional Stigma, Mental illness disclosureUniversity of Delaware, Department of Sociology and Criminal JusticePh.D
Live streaming communities, transparasocial relationships, and product purchase intentions among viewers
No full textBleakley, AmyResearch has yet to explain the complex and unique experience live streaming viewers have with their favorite live streamers. It is not well understood how parasocial & transparasocial relationships, the strength of online communities, and consumer outcomes relate to one another in the context of live streaming This current study asked college students ages 18-24 (n = 356) to describe how they perceive their favorite live streamer and the community surrounding that live streamer. Path analysis was utilized to understand how social affordances, transparasocial relationships, community indices, and purchase intentions are interlinked in live streaming contexts. Results showed that specific affordances, like social presence, were positively associated with the stronger streamer-audience relationships, and also was associated with community experiences through these streamer audience relationships. Similarly, the streamer-audience relationships were positively related to a stronger community experience and increased audience purchase intentions; stronger community experiences were also positively associated with. Of note is that explicit persuasive knowledge moderated the relationship between the streamer audience relationship and purchase intentions in that high levels of explicit persuasive knowledge was associated with higher purchase intentions for those with strong streamer audience relationships. Findings from this study can be used to better understand the dynamic relationship specific online users have with various live streamers and their communities.University of Delaware, Department of CommunicationM.A
Simultaneous population genomics of hosts and their parasites with selective whole genome amplification
No full textThis article was originally published in Parasites & Vectors. The version of record is available at: https://doi.org/10.1186/s13071-025-07087-1
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, 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 changes were made. 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/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background Generating parasite genomes is challenging when little of the DNA in infected host tissue is from the parasite. We used selective whole genome amplification (SWGA) to generate genomic data from wildlife samples of the avian haemosporidian Haemoproteus majoris (lineage PARUS1) and its host, the blue tit (Cyanistes caeruleus). Methods We used SWGA to amplify the parasite DNA in nine avian blood samples collected between 1996 and 2021, and subsequently performed short-read sequencing and bioinformatically separated the host and parasite reads in each sample. Results SWGA increased the percentage of parasite reads significantly. Sequencing to a depth of about 56 million reads (forward and reverse) per sample resulted on average (± standard error [SE]) in 11.3X ± 1.85 for the host genome and 1.17X ± 0.446 mean depth of coverage for the host and parasite, respectively, after SWGA. Furthermore, about 74% of the host genome (genome size approx. 1.2 Gb) and 33% of the parasite genome (approx. 23.9 Mb) had at least 1X coverage on average; two samples had 1X coverage of approximately 60% of the parasite genome. Parasite sequencing success was positively correlated with parasitemia. When comparing the parasite sequences in the four best samples, we identified 9895 sites (minimum 5X coverage) that varied among the infections. When filtering the full dataset to at least six samples per variant, we identified 14,512,339 and 7068 sites that varied among samples in the host and parasite populations, respectively, revealing variation among samples and years. Conclusions SWGA facilitates dual host-parasite population genomics in this system and will greatly expand our understanding of host-parasite interactions over space and time.Open access funding provided by Lund University. We performed bioinformatic analyses on the University of Delaware’s BIOMIX cluster and used the BioStore data management resource at the University of Delaware Bioinformatics Data Science Core [RRID:SCR_017696]. These resources are supported by Delaware INBRE (NIH/NIGMS P20 GM103446), NIH Shared Instrumentation Grant (S10 OD028725), the State of Delaware and the Delaware Biotechnology Institute. VAE was supported by funding from USDA Hatch (DEL00854, NE1943, and NE2443). IS was supported by the Delaware INBRE program (NIH/NIGMS P20 GM103446). OH was supported by the Swedish Research Council (VR 2021–03663) and the Erik Philip-Sörensens Foundation. AT was supported by the Carl-Trygger Foundation
Enhanced Matrix Completion Method for Super-resolution Tomography SAR Imaging: First Large-scale Urban 3-D High-resolution Results of LT-1 Satellites Using Monostatic Data
No full textThis article was originally published in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. The version of record is available at: https://doi.org/10.1109/JSTARS.2025.3604224
This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/LuTan-1 (LT-1) constellation is an innovative distributed L-band spaceborne synthetic aperture radar (SAR), which can potentially provide tomographic mapping with twin satellites, i.e., Tomographic SAR (TomoSAR) imaging. Usually, compressed sensing (CS) techniques can be used in TomoSAR imaging to improve the elevation resolution by exploiting the layout sparsity. However, the off-grid effect of discrete dictionary used in traditional CS methods tends to dramatically degrade the imaging performance. In this paper, a novel non-convex enhanced matrix completion (NcEMC) algorithm is proposed for gridless super-resolution TomoSAR imaging. Specifically, a Hankel matrix completion model is firstly designed to effectively exploit the latent data structure in an off-grid manner. Benefiting from the enhanced low-rankness of Hankel matrix form, a more refined uniform baseline observation is reconstructed from the original configuration using the optimization of matrix completion with the achievement of signal enhancement. To avoid using a regularization term to balance the traditional singular value decomposition solution of Hankel matrix, the proposed algorithm restates the low-rank constraint in a symmetric decomposition manner, which is beneficial to reduce the computation cost. Subsequently, an incoherence condition is introduced as a significant constraint in the non-convex Hankel matrix reconstruction process. To this end, a projected gradient descent iteration method is designed to satisfy the incoherence condition, thereby facilitating a more robust and accurate process of data reconstruction. Meanwhile, this paper presents the first large-scale urban 3-D high-resolution results of LT-1 satellites. We use a collection of 10 repeat-pass LT-1 monostatic SAR images to demonstrate the entire processing in tomographic SAR imaging application and the superiority of the proposed algorithm.This work of Zhou and Xu was supported in part by the National Science Foundation of China (NSFC) under Grant 62071113, the Natural Science Foundation of Jiangsu Province under Grant BK20211559, the Fundamental Research Funds for the Central Universities under Grant 2242022k60008, and in part by Oriental Talent Plan Youth Project CYQN2023076
A CORE Future of Sustainability and Healing
No full textGauger-Cobb Middle School, established in 1972, and located in Newark, DE, serves as an ideal site for a landscape redesign due to its potential to improve both educationally and spatially. Newark, on a city scale, is also looking at ways to better integrate sustainable design and community health into its urban fabric. This project will focus on rearranging and designing existing elements, redesigning the outdoor spaces of the school to enhance environmental conservation and sustainability, and promoting student well-being to create a more engaging and educational environment. Key elements will include outdoor learning, green play spaces, native plantings for wildlife conservation, and stormwater management systems like rain gardens and bioswales to address the region’s water management needs. The redesign will also aim to increase accessibility and foster a sense of community in the surrounding area through inviting, functional recreation spaces and physical activity. The surrounding forest area, will act as a conservation park network with trails and signage, to promote environmental stewardship, to encourage outdoor activity, and to connect communities to nature and each other. By taking advantage of this beautiful historic opportunity of provided land, we can create a future for lower-class surrounding communities and utilize the land to foster growth and prosperity for all.
Goals & Objectives
COLLECTIVE OUTDOOR INTERACTION
- Tending to the five forms of cognitive play
- Tending to all student types and needs
- Designing through all of the different classifications of space
OPEN-ENDED OUTDOOR LEARNING
- Connect curriculum to the natural and built environment
- Cultivate collaboration and communication
- Foster curiosity through exploration
RESTORATIVE FOREST WETLANDS
- Control water and riparian restoration
- Designing artful waterbodies
- Woodland conservation & ecological planting awareness
ESTABLISH COMMUNITY CORRIDORS
- Conserving this site to be a core forest area for wildlife
- Creating connecting trails for community interaction
- Creating educational signage to span across the sit
Caregiver strain and quality of life: exploring the moderating role of caregiver age in an I/DD context
No full textEarnshaw, Valerie A.The number of diagnosed cases of intellectual and developmental disabilities (I/DD) has risen in the last few decades, and advances in healthcare and support services have increased the life expectancy for this population. Policy changes promoting residential choice have resulted in more people with I/DD living at home with aging family caregivers. Caregiving for offspring with I/DD can lead to caregiver strain, which affects the quality of life (QoL) of both the caregiver and the family unit. While research on caregiver strain and its impact on QoL is growing, the moderating role of caregiver age and perceptions of mutuality remain underexplored. Aging caregivers face unique barriers compared to younger caregivers, and mutuality has been shown in other research contexts to mitigate caregiver strain, though this may vary across the life course. This explanatory-sequential mixed-methods study utilized Family Systems Theory and the Strengths and Vulnerabilities Integration (SAVi) model to examine caregiver age and mutuality as moderators in the relationship between caregiver strain and QoL. The study also investigated potential interactions between caregiver age and mutuality to explore whether mutuality’s moderating role evolves over time. Quantitative data was collected through a cross-sectional online survey with n=186 participants. Sixteen participants who completed the online survey were then invited to engage in semi-structured interviews for qualitative data collection, selected based on their age and responses to the quantitative survey. Qualitative data were analyzed in conjunction with quantitative findings. Moderation analyses indicated that caregiver age and mutuality alone did not moderate the caregiver strain-QoL association. However, there was a three-way interaction between caregiver strain, age and mutuality suggesting that higher mutuality levels weakened the association between caregiver strain and QoL–but only among younger caregivers. Qualitative data both supported and expanded quantitative findings. Specifically, caregivers of all ages reported significant strain; however, their experiences varied. Older caregivers described more physical strain than younger caregivers, indicating a greater need for tangible support. Recommendations are proposed for measurement approaches, policy development, and programmatic interventions.
Keywords: intellectual and developmental disabilities (I/DD), caregiver strain, mutuality, caregiver age, family systems theory, strengths and vulnerabilities integration model (SAVi), moderation analysis, semi-structured interviews, mixed methods, explanatory sequential. ☐ Keywords: intellectual and developmental disabilities (I/DD), caregiver strain, mutuality, caregiver age, family systems theory, strengths and vulnerabilities integration model (SAVi), moderation analysis, semi-structured interviews, mixed methods, explanatory sequential.University of Delaware, Department of Human Development and Family SciencesPh.D
