1,361 research outputs found

    Going Wild! Teaching about Wild Products from BC\u27s Coastal Rainforests: A Guidebook for Educatiors for Grades 4 -7

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    What type of plants did our ancestors collect and use from our coastal forests? How do people use these plants now? Why are they important to you and your family? How can we learn to recognize them and continue to use them in a sustainable way to strengthen our communities? This guidebook will help you and your students explore these questions. It provides background material on some special plants and mushrooms from the rainforests of BC’s Central and North Coast and Haida Gwaii that are important for many reasons.The activities in this guidebook focus on these species, how they are used and why they are important. The activities are designed for grades 4 to 7, but also include extension activities for other grades. Going Wild! Teaching about Wild Products from BC’s Coastal Rainforests has been developed specifically for First Nations on the Central and North Coast and Haida Gwaii, but it can be used as a resource for other coastal communities and in other locations in BC where these plants are found. We hope that this guide book will be a useful tool in helping your students find a closer connection with their environment, and with plants that have been, and continue to be, important to their communities

    Shaped nozzles for cryogenic buffer gas beam sources

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    Cryogenic buffer gas beams are important sources of cold molecules. In this work we explore the use of a converging-diverging nozzle with a buffer-gas beam. We find that, under appropriate circumstances, the use of a nozzle can produce a beam with improved collimation, lower transverse temperatures, and higher fluxes per solid angle

    Exploring Self-Concept for Students with Emotional and/or Behavioral Disorders as They Transition from Elementary to Middle School and High School

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    Although significant research has been conducted around assessment and intervention for students with emotional and/or behavioral disorders (EBDs), few have investigated specifically how students with EBD self-report on their academic and social competence, or self-concept. Using a national longitudinal database, this study explored how students with EBD reported their selfconcept in elementary school, how their reported self-concept changed as they transitioned to middle and high school, and, what factors influenced this change. Using latent growth modeling procedures, the study found that students with EBD reported high self-concept across time and that reported self-concept was most impacted by ethnicity (β = −.174) and urbanicity (β = −.113)

    Modeling Alzheimer’s disease using human cell derived brain organoids and 3D models

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    Age-related neurodegenerative diseases, like Alzheimer’s disease (AD), are challenging diseases for those affected with no cure and limited treatment options. Functional, human derived brain tissues that represent the diverse genetic background and cellular subtypes contributing to sporadic AD (sAD) are limited. Human stem cell derived brain organoids recapitulate some features of human brain cytoarchitecture and AD-like pathology, providing a tool for illuminating the relationship between AD pathology and neural cell dysregulation leading to cognitive decline. In this review, we explore current strategies for implementing brain organoids in the study of AD as well as the challenges associated with investigating age-related brain diseases using organoid models

    Seedbank Persistence of Palmer Amaranth (\u3ci\u3eAmaranthus palmeri\u3c/i\u3e) and Waterhemp (\u3ci\u3eAmaranthus tuberculatus\u3c/i\u3e) across Diverse Geographical Regions in the United States

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    Knowledge of the effects of burial depth and burial duration on seed viability and, consequently, seedbank persistence of Palmer amaranth (Amaranthus palmeri S. Watson) and waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer] ecotypes can be used for the development of efficient weed management programs. This is of particular interest, given the great fecundity of both species and, consequently, their high seedbank replenishment potential. Seeds of both species collected from five different locations across the United States were investigated in seven states (sites) with different soil and climatic conditions. Seeds were placed at two depths (0 and 15cm) for 3 yr. Each year, seeds were retrieved, and seed damage (shrunken, malformed, or broken) plus losses (deteriorated and futile germination) and viability were evaluated. Greater seed damage plus loss averaged across seed origin, burial depth, and year was recorded for lots tested at Illinois (51.3% and 51.8%) followed by Tennessee (40.5% and 45.1%) and Missouri (39.2% and 42%) for A. palmeri and A. tuberculatus, respectively. The site differences for seed persistence were probably due to higher volumetric water content at these sites. Rates of seed demise were directly proportional to burial depth (α=0.001), whereas the percentage of viable seeds recovered after 36 mo on the soil surface ranged from 4.1% to 4.3% compared with 5% to 5.3% at the 15-cm depth for A. palmeri and A. tuberculatus, respectively. Seed viability loss was greater in the seeds placed on the soil surface compared with the buried seeds. The greatest influences on seed viability were burial conditions and time and site-specific soil conditions, more so than geographical location. Thus, management of these weed species should focus on reducing seed shattering, enhancing seed removal from the soil surface, or adjusting tillage systems

    Chiral Assemblies of Pinwheel Superlattices on Substrates

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    The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles a holy grail for (meta)materials. Here we show that tetrahedral gold nanoparticles can spontaneously transform from a perovskite-like low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. While the corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror-asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices display strong chiroptical activity identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of the substrate-supported chiral superlattices facilitate manufacturing of metastructured coatings with unusual optical, mechanical and electronic characteristics

    Shaped nozzles for cryogenic buffer-gas beam sources

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    Cryogenic buffer-gas beams are important sources of cold molecules. In this work we explore the use of a converging-diverging nozzle with a buffer-gas beam. We find that, under appropriate circumstances, the use of a nozzle can produce a beam with improved collimation, lower transverse temperatures, and higher fluxes per solid angle

    Physics and Computing Performance of the Exa.TrkX TrackML Pipeline

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    The Exa.TrkX project has applied geometric learning concepts such as metric learning and graph neural networks to HEP particle tracking. The Exa.TrkX tracking pipeline clusters detector measurements to form track candidates and filters them. The pipeline, originally developed using the TrackML dataset (a simulation of an LHC-like tracking detector), has been demonstrated on various detectors, including the DUNE LArTPC and the CMS High-Granularity Calorimeter. This paper documents new developments needed to study the physics and computing performance of the Exa.TrkX pipeline on the full TrackML dataset, a first step towards validating the pipeline using ATLAS and CMS data. The pipeline achieves tracking efficiency and purity similar to production tracking algorithms. Crucially for future HEP applications, the pipeline benefits significantly from GPU acceleration, and its computational requirements scale close to linearly with the number of particles in the event
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