3,311 research outputs found

    Effects of Corn and Selected Weed Species on Feeding Behavior of the Stalk Borer, \u3ci\u3ePapaipema Nebris\u3c/i\u3e (Lepidoptera: Noctuidae)

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    Experiments were conducted in an outdoor insectary to examine behavioral interactions between fifth instar stalk borers, Papaiperna nebris, and potential host plant species. Plants tested included 6- and 8-leaf stage corn, Zea mays, and ten weed species (six broadleaf and four grass) commonly associated with corn production in southern Wisconsin. Broadleaf plants found to be acceptable hosts included Ambrosia trifida, Arnaranthus retroflexus, Rumex crispus, and Chenopodium album; Asclepias syriaca and Abutilon theophrasti were not acceptable as host plants. Corn and the other grass species (Agropyron repens, Bromus inermis, Dactylis glomerata, and Setaria faberi) were found to be acceptable hosts. All acceptable plants also supported larval development to the pupal stage, though on 6-leaf stage corn and the small-stemmed grasses the majority of larvae dispersed before completing development. Larvae developing on corn, A. triftda, and A. retroflexus pupated within the plant stem, whereas larvae developing on the other plants pupated in the soil near the plant on which they fed. Stalk borer larvae required substantially less time to bore into corn stalks than into the stems of the broadleaf plants. In a limited preference experiment, corn was clearly preferred as a host plant over the three broadleaf and one small-stemmed grass species tested

    Análisis de una propuesta de evaluación en relación con la estructura conceptual de la proporcionalidad

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    La presente propuesta es una aproximación reflexiva y critica de las prácticas evaluativas que se vienen desarrollando en la enseñanza básica y media en las instituciones de carácter privado de la ciudad de Cali, sustentada desde nuestra propia experiencia como docentes en ejercicio y estudiantes de último semestre en Licenciatura de Matemáticas y Física de la Universidad del Valle, y apoyada en el análisis de unas actividades piloto de intervención y evaluación matemática, en torno a diferentes nociones y conceptos relacionados con la estructura conceptual del tópico de proporción y proporcionalidad en los grados de séptimo de educación básica y décimo de educación media que se realizaron a fin de plantear una serie de interrogantes cruciales en torno a la evaluación, dado su carácter organizador, dinamizador y potencializador del currículo. Esta propuesta se apoyará en el marco metodológico de los organizadores del currículo, donde la evaluación es un eje fundamental en el análisis didáctico que permite la articulación y organización de un currículo significativo para los intereses de los educandos

    The role of virtual reality in built environment education

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    This study builds upon previous research on the integration of Virtual Reality (VR) within the built environment curriculum and aims to investigate the role of VR and three-dimensional (3D) computer modelling on learning and teaching in a school of the built environment. In order to achieve this aim, a number of academic experiences were analysed to explore the applicability and viability of 3D computer modelling and VR into built environment subject areas. Although two-dimensional (2D) representations have been greatly accepted by built environment professions and education, 3D computer representations and VR applications, offering interactivity and immersiveness, are not yet widely accepted. The study attempts to understand the values and challenges of integrating visualisation technologies into built environment teaching and investigates tutors’ perceptions, opinions and concerns with respect to these technologies. The study reports on the integration process and considers how 3D computer modelling and VR technologies can combine with, and extend, the existing range of learning and teaching methods appropriate to different disciplines and programme areas

    Network theory approach for data evaluation in the dynamic force spectroscopy of biomolecular interactions

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    Investigations of molecular bonds between single molecules and molecular complexes by the dynamic force spectroscopy are subject to large fluctuations at nanoscale and possible other aspecific binding, which mask the experimental output. Big efforts are devoted to develop methods for effective selection of the relevant experimental data, before taking the quantitative analysis of bond parameters. Here we present a methodology which is based on the application of graph theory. The force-distance curves corresponding to repeated pulling events are mapped onto their correlation network (mathematical graph). On these graphs the groups of similar curves appear as topological modules, which are identified using the spectral analysis of graphs. We demonstrate the approach by analyzing a large ensemble of the force-distance curves measured on: ssDNA-ssDNA, peptide-RNA (system from HIV1), and peptide-Au surface. Within our data sets the methodology systematically separates subgroups of curves which are related to different intermolecular interactions and to spatial arrangements in which the molecules are brought together and/or pulling speeds. This demonstrates the sensitivity of the method to the spatial degrees of freedom, suggesting potential applications in the case of large molecular complexes and situations with multiple binding sites
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