1,720,958 research outputs found
Diversidad de visitantes florales en agroecosistemas de frutales caducifolios y su relación con variables a escala local y de paisaje
Get PDFEn el paisaje agrícola de frutales caducifolios los polinizadores son indispensables debido a que estos cultivos son altamente dependientes a la polinización cruzada, no obstante, la diversidad y funcionalidad de los polinizadores está en riesgo a causa de factores a escala local como el uso intensivo de agroquímicos, y factores a escala amplia como la simplificación del paisaje. En este estudio se determinó la diversidad de insectos visitantes florales y polinizadores potenciales en agroecosistemas de frutales caducifolios; se realizó un acercamiento a la polinización del ciruelo cv. Horvin, se caracterizó el manejo de los cultivos y los elementos del paisaje, y se determinó la relación entre algunas variables de paisaje local y amplio con la diversidad del grupo funcional de abejas silvestres. Se encontraron 65 especies de visitantes florales asociados con 64 especies de plantas. Abejas (Hymenoptera: Apoidea) y moscas de la familia Syrphidae fueron los principales visitantes florales en el paisaje. La abeja Apis mellifera, las moscas de la familia Bibionidae y Eristalis sp., presentaron la mayor probabilidad de polinización del ciruelo. La diversidad de abejas se encontró correlacionada negativamente con características de la intensificación de la agricultura como el manejo agroquímico, en contraste, se benefició por mayor cobertura de bosques y pastos arbolados en el paisaje circundante. Este trabajo presenta el primer inventario de visitantes florales en agroecosistemas de frutales caducifolios en Colombia y aporta al entendimiento de la relación entre polinizadores y paisaje, lo cual será una base para tomar acciones de manejo a diferentes escalas que favorezcan la conservación y funcionalidad de los polinizadores.Abstract: In the agricultural landscape of deciduous fruit trees pollinators are essential because these crops are highly dependent on cross-pollination, however, the diversity and functionality of pollinators is at risk due to factors at the local scale such as the intensive use of agrochemicals, and large-scale factors such as landscape simplification. In this study, the diversity of floral visitor and potential pollinators in deciduous fruit tree agroecosystems was determined; an approach was made to the pollination of the plum cv. Horvin, the management of crops and landscape elements was characterized, and the relationship between some variables of local and wide landscape with the diversity of the functional group of wild bees was determined. We found 65 species of floral visitors associated with 64 species of plants. Bees (Hymenoptera: Apoidea) and flies of the family Syrphidae were the main floral visitors in the landscape. The bee Apis mellifera, the flies of the family Bibionidae and Eristalis sp., had the highest probability of plum pollination. The diversity of bees was found negatively correlated with characteristics of the intensification of agriculture such as agrochemical management, in contrast, it benefited by greater coverage of forests and wooded pastures in the surrounding landscape. This work presents the first inventory of floral visitors in deciduous fruit tree agroecosystems in Colombia and contributes to the understanding of the relationship between pollinators and landscape, which will be a basis to take management actions at different scales that favor the conservation and functionality of pollinators.Maestrí
Moscas de la fruta (Diptera: Lonchaeidae) y sus parasitoides naturales asociados a curuba Passiflora spp.y Passiflora bogotensisen Cundinamarca, Colombia
Get PDFLa presente investigación tuvo como objetivoconocer las especies de moscas de la fruta (Diptera: Lonchaeidae) y sus parasitoides naturales, que habitan tanto en cultivos de curuba Passiflora spp. con manejo agroecológico como en P. bogotensis, procedentes de diferentes localidades del departamento de Cundinamarca. El propósito fue verificar si las moscas de la fruta de la curuba y sus parasitoides pueden habitar también en ecosistemas naturales. La información recuperada sobre esta relación tritrófica moscas-enemigos naturales-pasifloras será una evidencia que permita evaluar la importancia que tienen las especies emparentadas, el manejo agroecológico de los cultivos y la conservación de los ecosistemas naturales, en razón a los múltiples servicios que prestan como el control natural. Esta investigación tuvo en cuenta el trabajo conjunto entre agricultor, estudiante y experto, debido a que la articulación del conocimiento científico y el conocimiento tradicional es la base de la innovación tecnológicapara la agricultura (Hoffmann et al., 2007)y permiteel diálogo de saberes y la investigación con enfoque ecosistémico
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
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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