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Creators/Authors contains: "Chen, Angela"

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  1. Neuron Sandbox is a browser-based tool that helps middle school students grasp basic principles of neural computation. It simulates a linear threshold unit applied to binary decision problems, which students solve by adjusting the unit's threshold and/or weights. Although Neuron Sandbox provides extensive visualization aids, solving these problems is challenging for students who have not yet been exposed to algebra. We collected survey, video, and worksheet data from 21 seventh grade students in two sections of an AI elective, taught by the same teacher, that used Neuron Sandbox. We present a scaffolding strategy that proved effective at guiding these students to achieve mastery of these problems. While the amount of scaffolding required was more than we originally anticipated, by the end of the exercise students understood the computation that linear threshold units perform and were able to generalize their understanding of the worksheet’s solve for threshold strategy to also solve for weights. 
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    Free, publicly-accessible full text available April 11, 2026
  2. Free, publicly-accessible full text available December 15, 2025
  3. The planetary model of the atom is alive and well in middle school science class—and in popular iconography—despite most educated adults’ awareness of its shortcomings. The model persists because it is easily visualized, intuitively understandable, and expresses important truths. Models don’t have to get everything right to be useful. Middle schoolers would be overwhelmed by a more correct description of electron orbitals as probability densities satisfying the Schrödinger equation. Better to just show orbitals as ellipses. In the current era, when immensely powerful AI technologies built on neural networks are rapidly disrupting the world, K-12 students need age-appropriate models of neural networks just as they need age-appropriate models of atoms. We suggest the linear threshold unit as the best model for introducing middle school students to neural computation, and we present an interactive tool, Neuron Sandbox, that facilitates their learning. 
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  4. Free, publicly-accessible full text available December 19, 2025
  5. Spin chemistry of photogenerated spin-correlated radical pairs (SCRPs) offers a practical approach to control chemical reactions and molecular emissions using weak magnetic fields. This capability to harness magnetic field effects (MFEs) paves the way for developing SCRPs-based molecular qubits. Here, we introduce a new series of donor-chiral bridge-acceptor (D-χ-A) molecules that demonstrate significant MFEs on fluorescence intensity and lifetime in solution at room temperature – critical for quantum sensing. By precisely tuning the donor site through torsional locking, distance extension, and planarization, we achieved remarkable control over key quantum properties, including field-response range and linewidth. In the most responsive systems, emission lifetimes increased by over 200%, and total emission intensity was modulated by up to 30%. This level of tunability, and rational design principle of optically addressable molecular qubits, represents a major leap toward functional synthetic molecular qubits, advancing the field of molecular quantum technologies. 
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  6. BackgroundThe prevalence of human papillomavirus (HPV) and its related cancers is a major global concern. In the United States, routine HPV vaccination is recommended for youth aged 11 or 12 years. Despite HPV being the most common sexually transmitted infection and the vaccine’s proven efficacy, the vaccination rate among US youth remains below the recommended 80% completion rate. Mobile health (mHealth) interventions have demonstrated promise in improving health. Examining and synthesizing the current evidence about the impact of mHealth interventions on vaccination coverage in youth and intervention characteristics could guide future mHealth interventions aimed at mitigating the vaccination gap and disease burden. ObjectiveThis study aims to conduct a systematic review to assess the effectiveness of mHealth interventions on parental intent to vaccinate youth against HPV and youth’s vaccine uptake. MethodsWe searched empirical papers through databases including Google Scholar, PubMed, CINAHL, PsycINFO, and Cochrane Library. The inclusion criteria were the following: (1) published between January 2011 and December 2022; (2) using mHealth aimed to improve HPV vaccination rate; (3) targeted unvaccinated youth or their parents; and (4) measured HPV-related knowledge, vaccination intention, or vaccine uptake. Overall, 3 researchers screened and appraised the quality of the eligible papers using the Melnyk Levels of Evidence and the Cochrane Grading of Recommendations Assessment, Development, and Evaluation methodology. Disagreements in search results and result interpretation were resolved through consensus. ResultsOverall, 17 studies that met the inclusion criteria were included in the final review. Most studies were conducted in the United States (14/17, 82%), used a randomized controlled trial design (12/17, 71%), and adopted behavior change theories or a culture-centric approach (10/17, 59%). mHealth interventions included SMS text message reminders, motivational SMS text messages, computer-tailored or tablet-tailored interventions, smartphone apps, web-based tailored interventions, social media (Facebook) campaigns, digital videos, and digital storytelling interventions. Approximately 88% (15/17) of the mHealth interventions demonstrated positive effects on knowledge, intention, or behaviors related to HPV vaccination. Overall, 12% (2/17) reported limited or no intervention impact on vaccine uptake or vaccine series completion. Effective vaccine uptake was commonly seen in interventions based on behavior change theories and those that provided culturally relevant information. ConclusionsThis systematic review identified the impact of mHealth interventions among unvaccinated youth and their parents, which showed improvement in HPV-related knowledge, vaccination intention, or vaccine initiation. The interventions that incorporated theories and culture-centric approaches revealed the most promising results. Although these outcomes are encouraging, future studies are needed to investigate factors associated with the success of interventions using SMS text messaging or social media. More studies are also needed for a better understanding of the intervention elements that boost the responses of age-specific and ethnicity-specific populations. 
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  7. IntroductionWhile vaccines are crucial for disease prevention, disparities in vaccination coverage persist among youths aged 10 to 29 years, including within the United States. Serious games are emerging as a new strategy to address vaccine hesitancy. This systematic review aimed to aggregate and assess the current evidence on game-based interventions to improve youth vaccination rates, evaluating their impact and identifying factors influencing their effectiveness. MethodsThis systematic review was conducted through a meticulous search and evaluation of literature from databases including PubMed, Cumulative Index to Nursing and Allied Health Literature database, ProQuest platform, Cochrane Library, and Google Scholar. Studies were included if they (a) were designed with the purpose of improving youth vaccination rates; (b) were published in English; (c) were published between January 2011 and June 2023; and (d) evaluated the effect of game-based interventions. Search terms included Medical Subject Headings terms and keywords of the eligible articles. ResultsOut of 269 studies, 11 were included in the final analysis of this review. The earliest study dated back to 2013, with 5 being randomized controlled trial and 6 studies incorporating theoretical models in their design or outcome measures. The findings indicated a generally positive effect of game-based interventions on vaccine-related knowledge. However, the impact on actual vaccine uptake was limited. In-game avatar customization and collaboration games were found as effective tools for player engagement. ConclusionThe review findings indicated that serious games boost vaccine knowledge but lack strong evidence for influencing youth vaccine uptake. More rigorous research and tailored game designs are needed to determine the effectiveness of game-based interventions and effectively address the diverse needs of youth in vaccine decision-making. 
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  8. Abstract Small RNAs (sRNAs) of the fungal pathogenBotrytis cinereacan enter plant cells and hijack host Argonaute protein 1 (AGO1) to silence host immunity genes. However, the mechanism by which these fungal sRNAs are secreted and enter host cells remains unclear. Here, we demonstrate thatB. cinereautilizes extracellular vesicles (EVs) to secrete Bc-sRNAs, which are then internalized by plant cells through clathrin-mediated endocytosis (CME). TheB. cinereatetraspanin protein, Punchless 1 (BcPLS1), serves as an EV biomarker and plays an essential role in fungal pathogenicity. We observe numerousArabidopsisclathrin-coated vesicles (CCVs) aroundB. cinereainfection sites and the colocalization ofB. cinereaEV marker BcPLS1 andArabidopsis CLATHRIN LIGHT CHAIN 1, one of the core components of CCV. Meanwhile, BcPLS1 and theB. cinerea-secreted sRNAs are detected in purified CCVs after infection.Arabidopsisknockout mutants and inducible dominant-negative mutants of key components of the CME pathway exhibit increased resistance toB. cinereainfection. Furthermore, Bc-sRNA loading intoArabidopsisAGO1 and host target gene suppression are attenuated in those CME mutants. Together, our results demonstrate that fungi secrete sRNAs via EVs, which then enter host plant cells mainly through CME. 
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  9. Summary Spray‐induced gene silencing (SIGS) is an innovative and eco‐friendly technology where topical application of pathogen gene‐targeting RNAs to plant material can enable disease control. SIGS applications remain limited because of the instability of RNA, which can be rapidly degraded when exposed to various environmental conditions. Inspired by the natural mechanism of cross‐kingdom RNAi through extracellular vesicle trafficking, we describe herein the use of artificial nanovesicles (AVs) for RNA encapsulation and control against the fungal pathogen, Botrytis cinerea . AVs were synthesized using three different cationic lipid formulations, DOTAP + PEG, DOTAP and DODMA, and examined for their ability to protect and deliver double stranded RNA (dsRNA). All three formulations enabled dsRNA delivery and uptake by B . cinerea . Further, encapsulating dsRNA in AVs provided strong protection from nuclease degradation and from removal by leaf washing. This improved stability led to prolonged RNAi‐mediated protection against B . cinerea both on pre‐ and post‐harvest plant material using AVs. Specifically, the AVs extended the protection duration conferred by dsRNA to 10 days on tomato and grape fruits and to 21 days on grape leaves. The results of this work demonstrate how AVs can be used as a new nanocarrier to overcome RNA instability in SIGS for crop protection. 
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