31825 research outputs found
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Optimizing in-vitro production of Delaware-isolated Pythium zoospores
No full textSparks, Erin E.Betts, Alyssa K.Pythium, which are fungus-like eukaryotic plant pathogens, are notorious for significant worldwide crop losses by causing damping off, seedling blights, root rots, foliar blights, or stalk rots across hundreds of plant species. Pythium propagates in various ecological niches by producing oospores, sporangia, and mycelial hyphae. However, infections on host tissue are primarily initiated by specialized, motile, asexual structures known as zoospores released from sporangia. Research focused on Pythium-plant interactions is advanced by understanding the biology of Pythium spp., particularly through observations of zoospore production and visualization of infection. While previous studies have successfully produced zoospores via in vitro methods, consistent and reproducible methods for specific species of pathogenic Pythium remain limited, particularly for species like Pythium graminicola, a prominent pathogen of corn in the Mid-Atlantic United States. By refining pre-existing techniques to improve zoospore yield, efficiency, and production reliability, a method optimized for in vitro zoospore production of P. graminicola was developed. A new strategy of chopped inoculum plugs was also tested, and increased surface area exposure was found to enhance zoospore release. Chopped inoculum plugs from 7-day-old cultures grown on lima bean agar media, soaked in deionized water, and incubated under constant light and temperature for 24 hours, produced the highest number of zoospores, with an average of 7.9 × 10^3 zoospores/mL for P. graminicola. This optimized method was later tested on P. dissotocum, P. inflatum, P. torulosum, and Globisporangium sylvaticum to induce zoospore production and examine the relationship between phylogenetic relatedness and method responsiveness. Two out of four species tested responded positively, with P. dissotocum producing the highest and P. torulosum comparable to P. graminicola, while G. sylvaticum and P. inflatum showed negligible to no zoospore production. This work builds on foundational methods, providing a reliable and reproducible approach for zoospore production to facilitate future research into Pythium biology, infection, diagnostics, and management within the framework of Mid-Atlantic corn.University of Delaware, Department of Plant and Soil SciencesM.S
The Behavioral Revolution in Agricultural and Resource Economics: A Perspective on the Past and the Future
No full textThis article was originally published in Journal of Agricultural and Resource Economics. The version of record is available at: https://doi.org/10.22004/ag.econ.369144
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License https://creativecommons.org/licenses/by-nc/4.0/This paper traces the past 50 years of evolution of behavioral economics within agricultural and resource economics, documenting how applied economistsÕ empirical observations of farmer behavior, environmental valuation anomalies, and food choice patterns contributed foundational insights to behavioral theory. The fieldÕs practical orientation led to early identification of key anomalies, including the endowment effect, adoption patterns, peer effects, other-regarding behavior and stigma effects. Through analysis of publication trends across five leading journals, we demonstrate steady growth in behavioral research. Finally, we examine institutional developments, including specialized research centers and policy applications, while acknowledging ongoing challenges regarding replication, external validity, and the limitations of nudge interventions, which provides fertile grounds for future research
Standard purification methods are not sufficient to remove micellular lipophilic dye from polymer nanoparticle solution
No full textThis article was originally published in RSC Pharmaceutics. The version of record is available at: https://doi.org/10.1039/D5PM00013K.
© 2025 The Author(s). Published by the Royal Society of Chemistry.
This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence (http://creativecommons.org/licenses/by-nc/3.0/).Tracking nanoparticles’ location is imperative for understanding cellular interactions, pharmacokinetics, and biodistribution. DiD is a lipophilic dye commonly used to label nanoparticles for trafficking studies. Herein, we show that DiD micelles form in polymer NP solutions during synthesis and can lead to false positive results in downstream assays. Potential methods to remove these micelles are also described.The authors thank Dr John Sperduto for his input and expertise as well as the Delaware Biotechnology Institute for their support. This work was supported by the National Institutes of Health under award numbers R35GM149292 and R35GM119659 and by the University of Delaware Summer Scholars Program. E. H. S. acknowledges support from the National Science Foundation Graduate Research Fellowship Program under award number 1940700
Biophysical modelling of intrinsic cardiac nervous system neuronal electrophysiology based on single-cell transcriptomics
No full textThis article was originally published in The Journal of Physiology. The version of record is available at: https://doi.org/10.1113/JP287595.
© 2025 The Author(s). The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.The intrinsic cardiac nervous system (ICNS), termed as the heart's ‘little brain’, is the final point of neural regulation of cardiac function. Studying the dynamic behaviour of these ICNS neurons via multiscale neuronal computer models has been limited by the sparsity of electrophysiological data. We developed and analysed a computational library of neuronal electrophysiological models based on single neuron transcriptomic data obtained from ICNS neurons. Each neuronal genotype was characterized by a unique combination of ion channels identified from the transcriptomic data, using a cycle threshold cutoff that ensured the electrical excitability of the neuronal models. The parameters of the ion channel models were grounded based on passive properties (resting membrane potential, input impedance and rheobase) to avoid biasing the dynamic behaviour of the model. Consistent with experimental observations, the emergent model dynamics showed phasic activity in response to the current clamp stimulus in a majority of neuronal genotypes (61%). Additionally, 24% of the ICNS neurons showed a tonic response, 11% were phasic-to-tonic with increasing current stimulation and 3% showed tonic-to-phasic behaviour. The computational approach and the library of models bridge the gap between widely available molecular-level gene expression and sparse cellular-level electrophysiology for studying the functional role of the ICNS in cardiac regulation and pathology.National Heart, Lung, and Blood Institute (NHLBI) U01 HL133360 and R01 HL161696: J.S., R.V.; National Institutes of Health (NIH) Common Fund Stimulating Peripheral Activity to Relieve Conditions (SPARC) Program OT2OD030534: R.V.; National Science Foundation (NSF) 1940700: M.G
Perceptions and experiences of food insecurity-related stigma in the United States
No full textKarpyn, AllisonStigma, defined as a multi-level social process, can result in social exclusion, reduced opportunities, and adverse health outcomes for target individuals or groups. Understanding and addressing manifestations of stigma related to the use of government (i.e., SNAP and WIC) and emergency (i.e., food banks, pantries, and cupboards) food assistance, and their impacts on program access among eligible adults, is pivotal for achieving health equity. This dissertation, guided by the Stigma and Food Inequity Framework, included three studies with the following aims: 1) conduct a scoping review of the literature to evaluate individual- and structural-level stigma associated with both government and emergency food program utilization, 2) conduct a qualitative study with emergency food program clients regarding individual-level experiences of food insecurity-related stigma, and disclosures related to participation in emergency food programs, and 3) conduct a qualitative study with emergency food program clients examining experiences of structural-level stigma. This dissertation offers important insights into food insecurity-related stigma and its manifestations within government and emergency food programs in the U.S., driving intervention strategies aligned with the Stigma and Food Inequity Framework.University of Delaware, Department of Human Development and Family SciencesPh.D
Characterizing the developmental, motor, and neuroimmunological impacts within a non-invasive two hit mouse model of neonatal hypoxic ischemic encephalopathy
No full textWright-Jin, ElizabethSchwarz, Jaclyn M.Hypoxic ischemic encephalopathy (HIE) is a perinatal brain injury characterized by a lack of oxygen or blood flow to the fetal brain. HIE is one of the most serious causes of neurological deficits in children born at term and can lead to significant long-term deficits including cerebral palsy, epilepsy, learning deficits, and vision/hearing impairments. There are limits to therapeutic hypothermia, the only current treatment of HIE, as it must be initiated within six hours following birth, and up to 40% of treated infants still experience adverse neurodevelopmental outcomes. Other treatments have shown promise in animal models; however, none have been effective in clinical trials. This points to the need for additional animal models that better incorporate the risk factors and etiology of HIE to develop and test additional treatments. ☐ Maternal immune activation (MIA) is a significant risk factor for the development of HIE and cerebral palsy. MIA is hypothesized to have a priming effect on microglia, the immune cells of the brain, leading to an exacerbated proinflammatory response and worse outcomes following a later immune challenge. It is easy to include MIA in animal models through the peripheral injection of bacterial or mimetics into pregnant animals, additionally incorporating the maternal and fetal interaction that occurs in HIE. ☐ Our novel, non-invasive model of HIE pairs maternal immune activation via the administration of lipopolysaccharide (LPS) on gestational day 18 with a progressive hypoxia to 0% oxygen for 8 minutes on postnatal day 6 (P6). The aims of this dissertation are 1) to characterize developmental changes and long-term motor outcomes within our model of HIE, 2) to investigate areas of injury or altered microglia response within the brain at acute and long-term timepoints, and 3) to characterize the neuroimmune response to our model of HIE. ☐ We found that our model of HIE leads to significant developmental delays within the neonatal period in most, but not all, measures. In adulthood, HIE animals exhibited long-term motor deficits including reduced forelimb strength and gait disturbances but not altered social behavior. Anatomical MRI one day following the second hit of hypoxia identified that HIE animals trended towards a decrease in overall brain volume, but did not have a decrease in the volume of specific brain regions. In adulthood, MRI did not find any differences in overall brain volume. We utilized immunohistochemistry to quantify the density of apoptotic cells, neurons, and microglia in motor regions one day after hypoxia (P7). HIE animals had significantly increased microglial density in the cerebellum, indicating region-specific neuroinflammation. There were no differences in the density of apoptotic cells or neurons in either the dorsal striatum or the cerebellum on P7. We additionally analyzed neuronal density in adulthood in the dorsal striatum and found no decreases due to HIE. We utilized bulkRNAseq to characterize the initial transcriptional response of microglia to HIE. On P7, microglia exhibited an upregulation of pro-inflammatory, proliferation-related, and apoptotic gene sets. Single cell-RNAseq on P8/P10 revealed two microglia subclusters of interest following HIE. Pseudobulk analysis of this data revealed increased expression of genes in microglia related to mobility and localization of cells following HIE, as well as an upregulation of epigenetic machinery and neurodevelopmental genes in macrophages. ☐ Together these results support our model as a valid model of HIE as it produces motor deficits throughout the lifespan as well as an initial proinflammatory response in microglia following insult. We were additionally able to characterize the nuanced response of microglia and macrophages within our model. This model does not produce an overt focal histological injury or increase in apoptosis at the timepoints assessed and therefore represents a milder or global injury phenotype. HIE in humans is highly heterogeneous and varies in severity and outcome. Therefore, this novel model fills a niche which will contribute to further our understanding of the variable phenotype of HIE.Ph.D.University of Delaware, Interdisciplinary Neuroscience Graduate Progra
INVESTIGATING THE ROLE OF DKK3 IN TEMPOROMANDIBULAR JOINT HOMEOSTASIS IN THE MURINE MODEL
No full textenterThe temporomandibular joint (TMJ), also known as the jaw joint, is essential to daily
human function. Without proper jaw function, necessary activities like eating, drinking, and
speaking can become painful and impaired [1]. In studying the TMJ, both histologically and
molecularly, our understanding of how disorders of the jaw joint develop can be furthered.
Controlling the canonical Wnt (cWnt) signaling pathway has been thought to have
essential function in the maintenance of the TMJ. Preventing cWnt signaling in putative
progenitor cell populations may allow for these cells to differentiate into necessary fibrocartilage
for the TMJ articulating surfaces [2]. One likely inhibitor of cWnt, which has been less
thoroughly researched in vivo, is Dkk3.
To study the role of Dkk3 in TMJ homeostasis in vivo, the Dkk3 gene was deleted in
transgenic mice and compared to Dkk3 wild type. Then, the TMJs of these mice were studied
through H&E histology, fluorescent reporters tagging Wnt signaling activity, and micro-CT.
Our findings suggest that Dkk3 is indeed important in vivo to the maintenance of putative
stem progenitor populations in the TMJ condyle and fossa, and in the absence of Dkk3 these
populations may be depleted and differentiated into bone by excessive Wnt signaling, causing
abnormal TMJ features, particularly in the fossa.ente
Proprioceptive Thresholds Are Indicators of Upper Limb Perception After Stroke
No full textThis article was originally published in Neurorehabilitation and Neural Repair . The version of record is available at: https://doi.org/10.1177/15459683251363245
© The Author(s) 2025Background: Proprioception is critical for daily activities and is often impaired after stroke. Recent studies have highlighted the prevalence of proprioceptive impairments of the upper limb in stroke; however, few studies have examined the relationship between proprioceptive impairments and motor function. Objective: We examined how proprioceptive detection thresholds (Movement Discrimination Thresholds (MDT)) relate to existing assessments of upper limb proprioceptive, motor, and
clinical function after stroke.
Methods: Stroke (N=39) and control participants (N=39) completed five tasks using the Kinarm Exoskeleton Lab: 1) MDT— a single-arm proprioceptive task assessing movement detection threshold, 2) Position Matching—a bilateral matching task assessing static limb position sense, 3) Kinesthetic Matching— a bilateral matching task assessing sense of limb motion, 4) Visually Guided Reaching—a task assessing upper limb motor control, and 5) Reaching without Vision— a task assessing upper limb motor control with increased reliance on proprioceptive feedback.
Results: Stroke participants were significantly impaired on all robotic tasks compared to controls. We found that MDT was correlated with bilateral matching robotic tasks of proprioception, including Position Matching (ρ=0.64, p<0.001) and Kinesthetic Matching (ρ=0.56, p<0.001). However, MDT was not significantly correlated with robotic tasks of motor control or clinical measures.
Conclusions: MDT, a single-arm measure that reduces motor requirements in proprioceptive testing, was significantly correlated to existing robotic measures of proprioception. MDT is capable of measuring impairments in perception that may be independent from impairments in action-based motor function.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by a Canadian Institutes of Health Research (CIHR) Operating Grant (MOP 106662, SPD), a Heart and Stroke Foundation of Canada Grant-in-Aid (SPD), a National Science Foundation Grant (#1934650, JAS), Ontario Research Foundation Grant (ORF-RE-09-112, SHS), and GSK chair in Neuroscience (SHS)
Ascribed status and perceived gender influences on trust decisions
No full textKubota, Jennifer T.Everyday humans need to decide whom and why to trust to successfully navigate their social world. Investigations of trust during decision-making have begun to explore how various social characteristics of interaction partners influence trust in others. This paper aims to understand how the perceived gender and socioeconomic status (SES) of others influence subsequent trust. More specifically, using a modified Trust Game paradigm, we aimed to uncover how trust processes during decision-making may be simultaneously shaped by status and gender. Participants (n = 44) played 256 trials of the Trust Game with 64 unique partners who varied in perceived gender and assigned status. Each unique partner varying in gender and status was pre-determined to share back invested money twice and keep it twice during the game. During gameplay, participants demonstrated a bias to preferentially trust individuals of high status regardless of their perceived gender. These results provide further evidence of positive evaluative bias towards high SES individuals. ☐ Keywords: socioeconomic status, perceived gender, trust, decision-makingUniversity of Delaware, Department of Psychological and Brain SciencesM.S
A global open-source dataset of monthly irrigated and rainfed cropped areas (MIRCA-OS) for the 21st century
No full textThis article was originally published in Scientific Data. The version of record is available at: https://doi.org/10.1038/s41597-024-04313-w.
© 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/.
This research was featured in UDaily on 5/19/2025 at: https://www.udel.edu/udaily/2025/may/global-crop-data-irrigation-agriculture/Crop production is among the most extensive human activities on the planet – with critical importance for global food security, land use, environmental burden, and climate. Yet despite the key role that croplands play in global land use and Earth systems, there remains little understanding of how spatial patterns of global crop cultivation have recently evolved and which crops have contributed most to these changes. Here we construct a new data library of subnational crop-specific irrigated and rainfed harvested area statistics and combine it with global gridded land cover products to develop a global gridded (5-arcminute) irrigated and rainfed cropped area (MIRCA-OS) dataset for the years 2000 to 2015 for 23 crop classes. These global data products support critical insights into the spatially detailed patterns of irrigated and rainfed cropland change since the start of the century and provide an improved foundation for a wide array of global assessments spanning agriculture, water resource management, land use change, climate impact, and sustainable development.We thank Gambhir Lamsal and Landon Marston for providing the harvested area statistics for the United States. E.A.K. and K.F.D. were supported by USDA Grant no. 2022-67019-37180 and the University of Alabama Global Water Security Center. E.A.K. was supported by the Consortium of Universities for the Advancement of Hydrologic Sciences (CUAHSI) through the Hydroinformatics Innovation Fellowship. S.H. was supported by the National Science Foundation Digital Transformation of Development Fellowship (#DGE- 2125913) and the National Science Foundation Graduate Research Fellowships Program (#DGE-1752814). S.S. was supported by the Deutsche Forschungsgemeinschaft (D.F.G., German Research Foundation) – SFB 1502/1-2022 – Projektnummer: 450058266