258 research outputs found

    Automatic Dynamic Aircraft Modeler (ADAM) for the Computer Program NASTRAN

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    Large general purpose finite element programs require users to develop large quantities of input data. General purpose pre-processors are used to decrease the effort required to develop structural models. Further reduction of effort can be achieved by specific application pre-processors. Automatic Dynamic Aircraft Modeler (ADAM) is one such application specific pre-processor. General purpose pre-processors use points, lines and surfaces to describe geometric shapes. Specifying that ADAM is used only for aircraft structures allows generic structural sections, wing boxes and bodies, to be pre-defined. Hence with only gross dimensions, thicknesses, material properties and pre-defined boundary conditions a complete model of an aircraft can be created

    Medicago LINC complexes function in nuclear morphology, nuclear movement, and root nodule symbiosis 1[OPEN]

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    Nuclear movement is involved in cellular and developmental processes across eukaryotic life, often driven by Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes, which bridge the nuclear envelope (NE) via the interaction of Klarsicht/ ANC-1/Syne-1 Homology (KASH) and Sad1/UNC-84 (SUN) proteins. Arabidopsis (Arabidopsis thaliana) LINC complexes are involved in nuclear movement and positioning in several cell types. Observations since the 1950s have described targeted nuclear movement and positioning during symbiosis initiation between legumes and rhizobia, but it has not been established whether these movements are functional or incidental. Here, we identify and characterize LINC complexes in the model legume Medicago truncatula. We show that LINC complex characteristics such as NE localization, dependence of KASH proteins on SUN protein binding for NE enrichment, and direct SUN-KASH binding are conserved between plant species. Using a SUN dominant-negative strategy, we demonstrate that LINC complexes are necessary for proper nuclear shaping and movement in Medicago root hairs, and are important for infection thread initiation and nodulation.National Science Foundation NSF-1440019, NSF-1613501Biotechnology and Biological Sciences Research Council BB/P007112/1European Molecular Biology Organization 699

    Disposal of Household Wastewater in Soils of High Stone Content (1981-1983)

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    Four experimental filter fields were constructed with built-in monitoring equipment in Nixa soils. These soils contain many chert fragments and a fragipan about 60 cm below the soil surface. The fragipan restricts downward movement of water and is the designlimitingfeature. The four filter fields were: 1. A standard filter field, 76 cm deep. The bottom of the trench was in the fragipan. 2. A modified standard filter field, 30 cm deep. The bottom of the trench was above the fragipan. 3. A modified pressure filter field, 40 cm deep. The bottom of the trench was above the fragipan. In addition, a pressure-distribution system was used to insure uniform distribution of effluent in the trench. Inadvertently, this field was installed in a different soil, and the results cannot be compared directly with the other three. 4. Another modified pressure filter field with the bottom of the trench only 6 cm below the soil surface. Observation of these systems confirms that placing filter fields higher in the soil above the hydraulically limiting horizon results in improved hydraulic performance. The presence of the fragipan amplified the adverse effects attributable to climatic stress. The seepage beds which are higher in the soil profile are able to handle the effluent load and climate load with less danger of surfacing

    Nuclei in motion: movement and positioning of plant nuclei in development, signaling, symbiosis, and disease

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    While textbook figures imply nuclei as resting spheres at the center of idealized cells, this picture fits few real situations. Plant nuclei come in many shapes and sizes, and can be actively transported within the cell. In several contexts, this nuclear movement is tightly coupled to a developmental program, the response to an abiotic signal, or a cellular reprogramming during either mutualistic or parasitic plant-microbe interactions. While many such phenomena have been observed and carefully described, the underlying molecular mechanism and the functional significance of the nuclear movement are typically unknown. Here, we survey recent as well as older literature to provide a concise starting point for applying contemporary molecular, genetic and biochemical approaches to this fascinating, yet poorly understood phenomenon

    Data Analysis Recitation Activities Support Better Understanding in SEA-PHAGES CURE

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    Course-based undergraduate research experiences (CUREs) are widely known to improve student learning outcomes in the sciences. Undergraduate students have a particularly difficult time interpreting the scientific data that they generate in these experiences – especially when lacking opportunity and exposure to science processes prior to entering higher education. Therefore, it is vital to structure these research experiences such that students can see maximal gains in their skills. This is especially true in the SEA-PHAGES (Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science) lab experience, which focuses on bacteriophages – a subject about which most undergraduate students have limited knowledge. In the SEA-PHAGES lab experience at The Ohio State University, we observed that while students made rapid gains in science process skills over the course of the semester, they still struggled to interpret the data they generated. To address this issue, we designed and implemented a set of five recitation activities to complement the lab experience, termed Recitation Activities to Improve Literacy in Science (RAILS). Using an adapted student assessment of learning gains (SALG) survey, we observed that these activities improved students' perceived ability to interpret their data, and students reported that they experienced significant gains in their data analysis ability as a result of the activities. We hope that other SEA-PHAGES instructors will similarly benefit from utilizing these recitation activities as part of their implementation of the curriculum. Primary image: Phages on RAILS. A bacteriophage is pictured driving a train engine down a track

    Urban Horticulture, from Local Initiatives to Global Success Stories

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    Urban horticulture describes economically viable horticultural production activities conducted in a city or suburb. It is a growing segment of horticulture in the United States as well as in developing countries, where the enormous growth of megalopolis is not backed by a simultaneous increase of farmland or agricultural productivity. Today, urban horticulture includes food sovereignty in underprivileged neighborhoods, increased availability of vegetables and fruits in big cities, healthy and diverse diets, improved food safety, low transportation costs, efficient resource use, and the mitigation of environmental impacts of horticultural production such as the emission of greenhouse gases. The workshop “Urban horticulture: From local initiatives to global success stories,” held at the 2018 American Society for Horticultural Science (ASHS) conference in Washington, DC, featured present and historical success stories of urban horticulture from Asia, Africa, Latin America, and the United States
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