58 research outputs found

    Una aproximaciĂłn semiĂłtico-comunicativa a las explicaciones de fĂ­sica universitaria

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    El propósito del estudio es indagar la actuación de profesores experimentados a partir del estudio y caracterización de explicaciones en clases de física en una facultad de ingeniería. La aproximación metodológica es cualitativa y estå enmarcada en un estudio descriptivo-interpretativo de casos. Considerando el caråcter social, didåctico, semiótico, comunicativo y multimodal de las clases de ciencias, seleccionamos el referente teórico båsico el aportado por Ogborn (1996). Este referente nos permite deducir una interesante propuesta analítica y metodológica para el estudio de las explicaciones. El estudio aportó 'pistas' acerca de 'cómo' los profesores transforman su conocimiento en uno 'enseñable' y que contribuye al desarrollo de habilidades y capacidades requeridas a un estudiante de ingeniería para ser un profesional competente. Extraemos también elementos de la pråctica docente que pueden usarse como material de enseñanza en programas orientados a la mejora de la pråctica del profesorado 'novel' y/o mås experimentado de física

    Rapid Ring-Opening Metathesis Polymerization of Monomers Obtained from Biomass-Derived Furfuryl Amines and Maleic Anhydride

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    Well-controlled and extremely rapid ring-opening metathesis polymerization of unusual oxanorbornene lactam esters by Grubbs third-generation catalyst is used to prepare a range of bio-based homo- and copolymers. Bio-derived oxanorbornene lactam monomers were prepared at room temperature from maleic anhydride and secondary furfuryl amines by using a 100 % atom economical, tandem Diels–Alder lactamization reaction, followed by esterification. Several of the resulting homo- and copolymers show good control over polymer molecular weight and have narrow molecular weight distributions

    TRY plant trait database – enhanced coverage and open access

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    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    The global spectrum of plant form and function

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    Effects of wind farm construction and operation on mire and wet heath vegetation in the Monte Maior SCI, north-west Spain

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    As part of the environmental impact assessment for the construction of a wind farm within the Monte Maior Natura 2000 Site of Community Importance (SCI) in Galicia, north-west Spain, a complete analysis of the development site’s important mire and wet heath plant communities was performed. The study included phytosociological characterisation, species-area metrics, calculation of α and ÎČ diversity, and analysis of physiognomical characteristics such as life forms, distribution ranges and phenology. Permanent quadrats were monitored for three years after construction of the wind farm in order to identify and describe any changes in floristic composition. Two phytosociological associations were recognised in mire habitat, namely Eleocharitetum multicaulis (Litorelletea uniflorae) and Carici durieui-Sphagnetum papillosi subas. ericetosum mackaianae (Oxycocco-Sphagnetea), whilst the wet heath was assigned to Gentiano pneumonanthe-Ericetum mackaianae (Calluno-Ulicetea). The two plant communities shared most physiognomical characteristics and 13–33% of species. Low values were obtained for α and ÎČ diversity, with about nine species per square metre for heathland and ten species per square metre for mire habitat. Hemicryptophytes dominated and no therophytes were recorded. The dominant plant families were Poaceae in heathlands and Cyperaceae in mires, and most of the species flowered in early or late summer. Both communities were stable and no change in any of the attributes investigated was observed during the study period. The results indicate that, so long as the traditional land use of low-intensity grazing can be maintained, there are no major hazards for these plant communities. However, some of the data suggest that the improvement of access to the area provided by the wind farm may result in an increase in human activity which could affect environmental conditions and thus the longer-term stability of the plant communities

    Effect of plant traits and population structure on the female reproductive success of the endemic Primula elatior subsp. bergidensis (Primulaceae)

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    his study explores the possible causes of variation in female reproductive success of the subspecific taxon Primula elatior subsp. bergidensis, a distylic endemic to the north-western Iberian Peninsula, by analysing both vegetative and reproductive traits. In three populations, we marked vegetative and reproductive individuals either by mapping the spatial position of every individual (in one population), or by establishing permanent quadrats (in the remainder two populations). We recorded floral morph (pin or thrum), width and length of the largest leaf, scape length, and number of flowers produced; all individuals were monitored to estimate the number of fruits and seeds produced. The results show that the morph ratio did not differ significantly from 1:1 in any of the populations. The number of flowers per plant varied between populations, and longer scape length was associated with higher fruit set in all populations. Plant size, scape length, and population spatial structure all had major effects on reproductive success, but the strength—and in some cases the direction—of the effects varied among populations.Peer reviewe
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