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VALIDATING DIFFERENTIALLY EXPRESSED GENES IN MET-2 DELETION MUTANTS AND IDENTIFICATION OF GENES RESPONSIBLE FOR SPERMATOGENIC DEFECTS REGULATED BY H3K9 METHYLATION
No full textenterOne important mechanism of genetic regulation is through post-translational
histone modifications. A histone methyltransferase known as MET-2 is an enzyme
responsible for such modifications. Specifically, MET-2 is responsible for
dimethylation of lysine 9 of histone H3 (H3K9me2), thus promoting heterochromatin
structure and resulting in repression of gene expression (Bessler et al., 2010).
Consequently, the absence of H3K9me2 leads to the overexpression of various genes,
threatening germline integrity, which is vital for proper embryonic development
(Delaney et al., 2019). The function of H3K9me2 has been previously studied in
oogenesis. However, these germline effects may also impact spermatogenesis in C.
elegans. This is evidenced by data indicating met-2 deletion males have significantly
reduced fertility. The goal of this research is to explore if misregulation of specific
genes is responsible for the spermatogenic defects seen in met-2 mutants. RNAseq was
performed on control and met-2 male germ lines and data was collected on
differentially expressed genes. Based on previous characterization for functions in
meiotic progression or fertilization I am investigating eight of the met-2 differentially
expressed genes that were found to be upregulated. My first project goal was to
validate upregulation of transcripts in met-2 males compared to control by performing
qPCR to analyze mRNA levels of the genes of interest. Analysis of qPCR results did
not verify differential expression of the genes of interest in male enriched samples of
met-2 versus control worms. The second project goal was to explore in more depth the
function of one gene of interest, rmd-1, and how misregulation of gene expression
contributes to the spermatogenic defects seen in met-2 mutants. The gene rmd-1 is
involved in spindle organization and microtubule attachment to the kinetochore.
Preliminary data of RNAi knockdown of rmd-1 shows reduced percent embryonic
viability, meanwhile having no effect on brood size. Although both gametogenesis and
fertilization occur in rmd-1 knockdown animals, these results indicate that proper
expression of rmd-1 may be necessary for the production of gametes of high quality. I
have also begun examining spermatogenesis-specific effects of rmd-1 RNAi
knockdown via male Embryonic Viability Assays and DAPI staining of the dissected
male gonads. Thus far, rmd-1 RNAi knockdown males may have an extended
transition zone. More replicates of male EVAs, as well as additional staining and
imaging of the gonads in the future will help further elucidate details of the possible
role of rmd-1 in spermatogenic defects regulated by H3K9 methylation.ente
“They Just Don’t Get That We Matter”: Black Boys’ Critical Consciousness Development During a Health Crisis and Racial Reckoning
No full textThis article was originally published in Urban Review. The version of record is available at: https://doi.org/10.1007/s11256-025-00728-w.
© 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/.While the COVID-19 pandemic and heightened racial unrest throughout 2020–2021 brought forth unprecedented disruption and trauma to youth and their families globally, these societal occurrences also provided fodder for youth learning and development. We use a theory of critical consciousness development (e.g., critical reflection, critical motivation, and critical action) and a racialized lens on social-psychological “mattering” to explore the voiced perspectives of adolescent Black high school boys, who participated in our school-university research partnership called The Black Boy Mattering Project. Findings from focus group interviews, gathered over the course of two school years, revealed that as participants navigated the health crisis and widespread racial reckoning, they deepened their critical consciousness of their marginal mattering. Marginal mattering reflects a type of perceived insignificance driven by sensing hyper-awareness from others for the alleged negative traits of one’s minoritized (e.g., racial) group. It led to Black boys feeling unappreciated, undervalued, and even feared in society and school environments. Findings show that while maneuvering COVID-19, participants’ encounters with Black Lives Matter via social media and news outlets inspired their critical reflection on the racial realities that framed their social and school lives and fueled their marginal mattering. Participants also determined protestors’ capacity to impact social change for the Black community, which inspired them to evaluate their critical motivation for making school-level change. While participants did not join street-level protests, they engaged in critical action through social media and some school-based endeavors. Implications suggest ways forward for more humanizing school policies and practices.The funding was provided by Spencer Foundation (Postdoctoral Research Development Award) and the University of Delaware Partnership for Public Education (PPE Fellowship)
Getting Misinformation Wrong: Why Content Fixes Can't Solve Structural Problems
No full textThis paper argues that the contemporary “misinformation panic” misdiagnoses the challenges facing democratic societies. While false and misleading information can cause harm, the dominant response—fact-checking, content moderation, and algorithmic interventions—rests on the faulty “asymmetry assumption” that misinformation operates differently from accurate information. In reality, belief formation follows symmetrical processes shaped by identity, partisanship, and epistemic communities. Survey design flaws, definitional drift, and selective issue focus have inflated the perceived prevalence and impact of misinformation, fueling a moral panic sustained by third-person effects and elite institutional interests. Rather than treating misinformation as a contagion to be eradicated, the paper reframes it as a symptom of deeper structural problems: epistemic polarization, institutional distrust, media fragmentation, and elite legitimation of false claims. Addressing these challenges requires moving beyond content-focused interventions toward structural reforms that build epistemic resilience, revitalize local news, strengthen democratic institutions, and realign elite incentives. By shifting attention from supply-side content fixes to the demand-side and structural conditions that foster receptivity to misleading information, this paper outlines a more effective path toward democratic resilience in an era of fragmented knowledge communities
An investigation of relationships between elementary teachers' skills for analyzing videos of teaching and skills for lesson planning
No full textJansen, AmandaDesigning a professional development program that supports teachers to improve multiple teaching skills is a complex endeavor. In this dissertation study, I outline an exploration of possible relationships between two teaching skills: analyzing videos of teaching and lesson planning. I used teacher noticing (van Es & Sherin, 2002; Sherin, 2017) as a framework to explain why these relationships might exist. To investigate this relationship, I used a subset of data from a research project that I was a part of for four years. The data included open-ended responses from participants to prompts that asked them to analyze video clips of teaching (other teachers’ teaching) and to plan a lesson by interpreting written curriculum materials. Both quantitative and qualitative findings supported the use of teacher noticing as a broader construct that can be applied to multiple teaching skills. Correlation analyses revealed that there was a relationship between teachers’ analysis of teaching video and lesson planning skills. Specifically, teachers’ ability to describe the key mathematics in the video aligned with their lesson planning skills. I qualitatively described two cases that were around the trend line for these skills, and these cases tended to demonstrate the same teacher noticing dimension for both skills. I chose two additional cases as extreme cases to describe qualitatively, because they provided counterexamples to the trends in the sample; their open-ended answers showed an understanding of what the trend did not look like. This study has implications for professional development designers and facilitators. When engaging teachers in professional learning, teachers would benefit from opportunities to make connections between multiple teaching skills to simultaneously support the improvement of multiple teaching skills. Finally, this study demonstrates how educational researchers can recognize interconnections between multiple teaching skills by using teacher noticing dimensions as a framework to interpret teaching skills, if relevant.University of Delaware, School of EducationPh.D
EXPLORING THE IMPACT OF GLOBAL NORTH CULTURAL BIASES ON WILDLIFE PRACTICES IN THE GLOBAL SOUTH
No full textenterI explore the cultural biases embedded within Global North conservation
ideologies and their impact on wildlife practices in the Global South. The
advancement of wildlife conservation depends on understanding how historical
portrayals of Indigenous knowledge systems as “primitive” continues to impact how
global wildlife conservation is viewed by the Global North. Case studies from the
Pacific Northwest, the Amazon, and sub-Saharan Africa demonstrate the sustainability
and sophistication of Indigenous wildlife management practices, which are often
ignored or displaced by Western conservation models such as “Fortress
Conservation.” Through 11 interviews with professionals and students across diverse
countries, my research reveals ongoing tensions between Western scientific
frameworks and community-led approaches, including the displacement of Indigenous
peoples, inequitable conservation partnerships, and the criminalization of traditional
hunting. Historical legacies of colonialism and modern neocolonial structures—
particularly in economic and legal systems—continue to shape conservation
narratives, often placing blame on marginalized communities for environmental
degradation without addressing underlying socio-economic conditions. I argue for the
urgent need to decolonize conservation by integrating Indigenous knowledge,
addressing structural inequalities, and promoting more just, culturally respectful
approaches to wildlife management.ente
Neural and cognitive effects of exergaming interventions in autistic youth
No full textBhat, AnjanaChildren and adolescents with autism spectrum disorder (ASD) present with executive functioning (EF) and motor impairments. These co-occurring EF and motor challenges are correlated with and impact the core impairments of ASD, including socialization, communication, and restricted and repetitive behaviors. Exergaming is the use of video gaming platforms to promote physical activity, offering direct benefits to motor skills and, potentially, EF skills that are often unaddressed in mainstream autism services. Our systematic review of DMI studies in developmental disabilities confirmed robust motor improvements across populations; however, cognitive effects in autistic individuals were less conclusive due to a limited number of studies. Therefore, we investigated the neural underpinnings of EF and body coordination challenges in autistic youth, and the impact of digital motor interventions (DMIs) on cortical activation during EF and multilimb coordination tasks. ☐ Using functional near-infrared spectroscopy (fNIRS), autistic youth (N=15, age 11.5 ± 0.57, 5-16 years) demonstrated lower EF performance, as shown in standardized questionnaire Behavior Rating Inventory of Executive Function (BRIEF) and greater reaction time variability during fNIRS Flanker inhibitory control tasks, accompanied by altered cortical activation patterns compared to age- and sex-matched non-autistic youth. Specifically, they demonstrated hypoactivation in the left inferior parietal lobule (IPL), precentral gyrus (PCG), and middle frontal gyrus (MFG), as well as hyperactivation in the left superior temporal sulcus (STS), and less left lateralization during inhibitory control. Moreover, lower left MFG hypoactivation was associated with elevated EF impairments. Interestingly, in the ASD group, right IPL and left/right STS activation were associated with better EF performance, indicating a potential compensatory strategy in autistic youth. These findings suggest that autistic children have different activation patterns in the default mode network (DMN) and the central executive network (CEN) compared to non-autistic peers during inhibitory control performance. ☐ Autistic youth also exhibited lower body coordination performance, as indicated by standardized motor assessment Bruininks-Oseretsky Test of Motor Proficiency- 2nd (BOT-2), Developmental Coordination Disorder Questionnaire (DCD-Q), and greater movement errors during a fNIRS whole-body, multilimb coordination task compared to controls. FNIRS revealed STS hypoactivation and inferior frontal gyrus (IFG) hyperactivation, indicating altered sensorimotor integration. While non-autistic youth primarily activated STS and IPL, autistic youth showed predominant IFG engagement, which was associated with increased task errors and reduced coordination. ☐ Two pilot randomized controlled trials evaluated the effect of 2 DMIs on EF, fine motor, and cortical activation in autistic youth. The BrainyAct motor intervention (N = 24, Age :10.5 ± 0.5 years) showed some improvements in game-specific cognitive scores, but trainers encountered significant technological difficulties. The intervention failed to produce transfer effects during standardized EF or motor assessments. In contrast, the Nintendo Switch exergaming intervention (N = 30, Age: 12.6 ± 0.62 years) led to moderate improvements in cognitive flexibility in the Stroop task and moderately improved inhibitory control performance, with large between-group differences in the Flanker task; however, it did not enhance fine motor skills. ☐ fNIRS neuroimaging post-intervention revealed that Nintendo exergaming induced cortical changes linked to reduced cortical activation in the IFG and PCG for the young NE subgroup (<13 years), as well as decreased activation in the IPL, MFG, and IFG for the older NE subgroup. In addition, a general reduction in cortical activation was shown in the left hemispheres for the lower communication score NE subgroup, and in both hemispheres in the high communication score NE subgroup. The regions showing an intervention response corresponded with the DMN and CEN regions identified as important for EF performance in our previous studies. Nintendo exergaming interventions may improve inhibitory control in autistic youth by enhancing neural efficiency through the development of inhibitory control skills, suppressing DMN regions, and increasing processing speed by enhancing neurotransmitter levels and receptor sensitivity. However, although we found robust evidence of body coordination improvements in our larger pilot RCT, no training-related neural changes were observed during the fNIRS whole-body coordination tasks, highlighting the need to improve our fNIRS task to better capture intervention-related changes. ☐ In conclusion, this dissertation presents evidence for autism-specific fNIRS cortical activation patterns that inform the development of autism interventions and support the assessment of motor and executive function (EF) challenges in autistic youth. Furthermore, it demonstrates that carefully designed, accessible exergaming can support EF improvements in autistic youth.Ph.D.University of Delaware, Interdisciplinary Neuroscience Graduate Progra
Sensitivity of electronic structure to crystal distortions in infinite-layered LaNiO2
No full textThis article was originally published in Physical Review B. The version of record is available at: https://doi.org/10.1103/PhysRevB.111.014518.
©2025 American Physical Society.Recent observations of unconventional superconductivity (SC) in thin films of LaNiO2 (critical temperature c≃ 10 K) and in bulk single crystals of La3Ni2O7 under pressure c≃80K have cemented a long sought-after class of SC nickelates. In La1−SrNiO2, SC appears only in films for reasons not understood. We perform a combination of experiments to probe the crystal structure and magnetic order in bulk LaNiO2 together with ab initio calculations of the electronic structure. We find that the infinite layers are naturally buckled out-of-plane. The electronic bands are largely unaffected by the buckling, but uniaxial compression along the axis may lead to a Lifshitz transition.This paper has been supported by the U.S. Department of Energy (DOE), Grant No. DE-FG02-01ER45927. We acknowledge the support of the NIST, U.S. Department of Commerce, in providing the neutron research facilities used in this paper. Work at ORNL was supported by the DOE, Office of Basic Energy Sciences, Materials Sciences and Engineering Division and Scientific User Facilities Division. Support for this paper was also provided by the High-Tech Research Center Project for Private Universities from the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Specially Promoted Research (JSPS KAKENHI Grant No. 25000003), and Grant-in-Aid for Scientific Research (S) and (B) (JSPS KAKENHI Grants No. 25220803 and No. 25287087). Moreover, this paper was supported by the Strategic International Collaborative Research Program (LEMSUPER) from Japan Science and Technology Agency. Two of authors (K.K. and J.A.) were supported by IMRA Material Co., LTD. J.B.M. acknowledges funding from the Special Postdoctoral Researcher Program at RIKEN
Biophysical interactions of impurities, drug substance, and purification media in downstream bioprocessing
No full textLenhoff, Abraham M.In the manufacturing of biologics, the downstream process includes several steps that cumulatively isolate the product from impurities, which range in size from cells to colloids such as host-cell proteins and nucleic acids. Unit operations that can remove these impurities commonly take advantage of the innate biophysical differences between product and impurity, such as charge and size, and are often themselves composed of purification media that preferentially interact with either product or impurity to enable isolation. There is an increasing incentive to understand the interactions that dominate these unit operations to mitigate potential risks in product development prior to final commercialization and develop novel technologies to keep pace with changes such as intensified upstream productivity or novel therapeutic modalities. The goal of this work is to better characterize these interactions across an array of size scales and unit operations, such as capture and harvest steps. ☐ Primary depth filtration is commonly used as a harvest step in downstream bioprocessing to remove cellular impurities. Despite its ubiquity, the biophysical interactions resulting in particle deposition in a depth filter are largely unstudied. Several popular depth filters from an array of manufacturers are used in this step in industry, and this work details the microstructural characterization of a library of many such layers, with an eye to assessing likely filtration mechanisms and efficiencies when the media layers are challenged with a typical industrial cell culture fluid. ☐ Typical cell culture fluids themselves are also analyzed, and the characterized filters and feeds were used in several depth filtration experiments where biophysical particle deposition mechanisms were inferred from increasing resistance to flow and measured filtrate turbidity as a function of fluid loading and observed by several imaging methods on the spent filter media. The mechanisms observed include adsorption, direct filtration (sieving), and filter caking, with the feed and filter in question playing a major role in the prevalence or even dominance of each mechanism. ☐ The knowledge gained from the characterization of cell culture fluid, filter, and their mechanistic interplay in-process is then used to develop a mechanistic model. Previous modeling and mechanistic work relevant to depth filtration is considered in the development of such a model, which also includes additional considerations specific to the filtration of mammalian cells. The resistance and filtrate turbidity data collected are used as a basis to validate the performance of the model across a wide range of relevant process parameters and material attributes, and additional industrial data are also used as a challenge to the model. ☐ Following harvest is typically capture, where challenges to the capture of virus-like particle (VLP) biologics are commonly seen due to their large size. This work describes a novel capture approach for VLPs wherein the VLP is not purified within a capture chromatography resin, as is common and feasible with small modalities, but is instead captured in bulk solution by a ligand with tunable solubility properties. These properties allow a continuous affinity precipitation and filtration approach to capture, where the binding and insolubility of a microparticle ligand-target complex is followed by the washing of soluble impurities into the filtrate of a hollow-fiber membrane module and subsequent resolubilization and separation of target from the ligand. ☐ In some bioprocessing situations, individual impurities may persist through capture step and even beyond, propagating until the final drug substance, where they can often have deleterious side effects on the product. This work adds additional context to an area under active investigation, the biophysical interactions enabling this impurity persistence through several downstream unit operations. One particular hypothesis addressed is the notion that these impurities strongly associate to the product, such that the impurities move through the process along with the product. The binding strengths of a set of these impurities is measured to a panel of archetypal products, and the binding locations associated with these binding strengths are assessed both experimentally and computationally.University of Delaware, Department of Chemical and Biomolecular EngineeringPh.D
Advancements in germanium tin material characterizations and fabrication process technologies for photodetector and transistor applications
No full textZeng, YupingGermanium tin (GeSn) alloys have emerged as promising materials for optoelectronic devices operating in the Short-wave infrared (SWIR) and mid-infrared (MIR) and even regions, offering unique advantages over conventional semiconductor materials. The incorporation of tin (Sn) into germanium (Ge) allows for the tunability of the bandgap, enabling efficient light emission and absorption across a wide range of wavelengths, making GeSn ideal for SWIR and MIR applications. This material's compatibility with complementary metal-oxide-semiconductor (CMOS) technology further enhances its potential for integration into cost-effective, scalable photonic and electronic systems. Recent advancements in the growth, characterization, and doping of GeSn have demonstrated enhanced optical properties, including direct bandgap behavior in the SWIR and MIR spectral ranges, high carrier mobility, and improved device performance. Notably, GeSn also shows great promise in transistor applications, where the alloy's tunable properties allow for the development of high-performance field-effect transistors (FETs) with superior switching characteristics and enhanced electron mobility. The material's potential for integration in light-emitting diodes (LEDs), lasers, photodetectors (PDs), modulators, and transistors operating in the SWIR and MIR regions is unlocking new opportunities in telecommunications, environmental sensing, medical diagnostics, and infrared imaging. This thesis explores the progress in GeSn material development, device fabrication techniques, and its application in both optoelectronic devices and high-speed transistors, highlighting its role in advancing the performance and functionality of SWIR and MIR technologies.University of Delaware, Department of Electrical and Computer EngineeringPh.D
