1,720,964 research outputs found
Landscape linear elements in agroecosystems: its role as reservoir of biodiversity and implications for the conservation of plantpollinator interaction and the associated pollination service
No full textLa fragmentación del paisaje y las prácticas agrícolas pueden afectar ladiversidad de plantas y polinizadores e interacciones que los elementos lineales del paisaje (ELP) sostienen en los agroecosistemas. Para comprobarlo, se estudiaron veinte tramos de ELP (banquinas de caminos rurales), en la Pampa Interior (Partido de Carlos Casares, Buenos Aires, Argentina). En este trabajo, se consideraron tres características y contextos de los ELP a diferentes escalas de observación: ancho de los ELP (escala puntual), la ocupación del lote adyacente (escala local) y la heterogeneidad de hábitat (escala de paisaje). Durante dos temporadas consecutivas se examinó la influencia de esas características y contextos en la riqueza de plantas con flores entomófilas, la abundancia de unidades florales y la riqueza y abundancia de sus visitantes en los ELP (enfoque estructural). También se evaluó el efecto de las características y contextos en las redes de interacciones planta-polinizador (RPP) de los ELP y la provisión del servicio de polinización (enfoque funcional). La escala puntual fue la más importante, ya que los ELP más anchos tuvieron mayor riqueza de plantas, abundancia de visitantes florales y riqueza de interacciones en las RPP. Además, el número de visitas en plantas individuales aumentó en ELP más anchos y la cantidad de granos de polen conespecíficos disminuyó en los ELP con mayor abundancia de flores. A escala local, con el incremento de la riqueza de plantas en los ELP, aumentó la cantidad de granos de polen conespecíficos en ELP adyacentes a lotes sin cultivar. A escala de paisaje, sólo la uniformidad de las interacciones en las RPP disminuyó cuando la diversidad de paisaje fue mayor. Concluimos que la conservación y el manejo de los ELP en agroecosistemas manejados intensamente es prioritaria para mantener alta diversidad, RPP más complejas y funcionales y la provisión del servicio de polinización de mayor calidad y cantidad.Landscape fragmentation and agricultural practices can affect the plants and pollinators diversity and their interactions that landscape linear elements (LLE) host in agroecosystems. To prove this, twenty portions of LLE (road verges) were studied in the Argentine Pampas (Carlos Casares, Buenos Aires). In this study, three LLE contexts were selected in different scales of observation: width of that linear element (site scale), occupation of the adjacent fields (local scale) and habitat heterogeneity (landscape scale). During two consecutive seasons the influence of these contexts on the entomophilous flowering plants, the abundance of floral units and the richness and abundance of their visitors in the LLE (structural approach) were examined. Plantpollination interaction networks (PPN) and pollination service they provide (functional approach) were also evaluated. The site scale was the most important, since the widest LLE had higher plant richness, higher flower visitor abundance and interaction richness in PPN. In addition, the number of visits in individual plants increased in widest LLE and the number of conspecific pollen grains decreased in LLE with higher abundance of flowers. At local scale, the increase in plant richness in the LLE increased the number of conspecific pollen grains in the LLE adjacent to uncultivated fields. At landscape scale, the evenness of interactions in the PPN decreased when landscape diversity was higher. We conclude that, the conservation and management of LLE in agroecosystems intensely managed should be a priority to maintain high species diversity, more complex and functional interaction networks and a pollination service provision of high quality and quantity.Fil: Monasterolo, Marcos. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Animal pollination contributes to more than half of citrus production
No full textAnimal pollination is crucial for the reproduction and economic viability of a wide range of crops. Despite the existing data, the extent to which citrus crops depend on pollinators to guarantee fruit production still needs to be determined. Here, we described the composition of potential pollinators in citrus (Citrus spp.) from the main growing areas of Argentina; moreover, we combined Bayesian models and empirical simulations to assess the contribution of animal pollination on fruit set and yield ha−1 in different species and cultivars of lemons, grapefruits, mandarins, and oranges. Honeybee (A. mellifera L.) was the most commonly observed potential pollinator, followed by a diverse group of insects, mainly native bees. Regardless of citrus species and cultivars, the probability of flowers setting fruit in pollinated flowers was 2.4 times higher than unpollinated flowers. Furthermore, our simulations showed that about 60% of the citrus yield ha−1 can be attributable to animal pollination across all species and cultivars. Therefore, it is crucial to maintain environments that support pollinator diversity and increase consumer and to producer awareness and demand in order to ensure the significant benefits of animal pollination in citrus production.EEA Marcos JuárezFil: Monasterolo, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro regional de Energía y Ambiente para el Desarrollo Sustentable; ArgentinaFil: Monasterolo, Marcos. Universidad Nacional de Catamarca. Centro regional de Energía y Ambiente para el Desarrollo Sustentable; ArgentinaFil: Ramírez Mejía, Andrés F. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Ramírez Mejía, Andrés F. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología Regional; ArgentinaFil: Cavigliasso, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Schliserman, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional De Energía y Ambiente para el Desarrollo Sustentable (CREAS); ArgentinaFil: Schliserman, Pablo. Universidad Nacional de Catamarca. Centro Regional De Energía y Ambiente para el Desarrollo Sustentable (CREAS); ArgentinaFil: Chavanne, Valentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Carro, Claudia M. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Chacoff, Natacha. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Chacoff, Natacha. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología Regional; ArgentinaFil: Chacoff, Natacha. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo, Argentin
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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