1,720,984 research outputs found
Sigatoka-amarela da bananeira em função da nutrição mineral em solução nutritiva e da distribuição espacial da fertilidade do solo
Full text linkDissertação apresentada à Universidade Federal de Lavras, como parte das exigências do Programa de Pós-graduação em Agronomia/Fitopatologia, área de concentração em Fitopatologia, para a obtenção do título de Mestre.Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPqFitopatologiaEste trabalho foi realizado com o objetivo de avaliar a Sigatoka-amarela em mudas de bananeira, cultivadas em solução nutritiva e sobre omissão de nutrientes, bem como verificar o padrão espacial dessa doença no campo, correlacionando-o com a nutrição mineral por meio da geoestatística. Em solução nutritiva, a omissão de nutrientes causou sintomas visuais de deficiências nas mudas e resultou nas maiores áreas abaixo da curva de progresso do número de lesões da Sigatoka-amarela para os tratamentos sem K e S. Observou-se também que não foi possível avaliar a severidade da doença até 60 dias após a inoculação, em função da deficiência nas folhas inoculadas. No campo, com uso da geoestatística, foi observado que o gride principal apresentou moderado grau de dependência espacial com alcance de 193,71 m e o subgride apresentou agregação ou reboleira, com forte grau de dependência espacial, com alcance de 6,58 m, ajustou-se o modelo exponencial para ambos os grides. Nos mapas de krigagem ordinária, foi possível constatar a relação positiva entre a severidade da Sigatoka-amarela com os teores de fósforo, nitrogênio, potássio e cálcio e negativa com teores de magnésio, cobre e manganêsThis work was performed aiming at evaluating yellow Sigatoka in banana seedlings grown in nutrient solution and on nutrient omission, as well as to determining the spatial pattern of disease in the field, correlating it with balanced nutrition using geostatistical analyst. In nutrient solution, the nutrients omission caused visual deficiency symptoms in seedlings and reached the highest areas under the number of lesions of yellow Sigatoka curve progress for treatments without K and S. However, it was not possible to assess yellow Sigatoka severity until 60 days after inoculation due the extreme deficiency symptoms in inoculated leaves. Using geostatistics in the field work we found that the main grid showed a moderate degree of spatial dependence with a range of 193.71 m and the subgrid showed a strong degree of spatial dependence with a range of 6.58 m. Besides, we adjusted the exponential model for both grids and through ordinary kriging maps, it was possible to found a positive relationship between yellow Sigatoka severity with levels of phosphorus, nitrogen, potassium, and calcium and negative relationship with levels of magnesium, copper and manganes
Desenvolvimento e validação de escala diagramática para avaliação da Sigatoka amarela da bananeira
Full text linkA bananeira (Musa spp.) é cultivada em todas as regiões brasileiras, sendo a banana uma das frutas mais consumidas e de importância socioeconômica significativa para o país. Nas áreas com baixa produtividade, os principais fatores associados são a falta de tecnificação e o manejo inadequado de pragas e doenças. Dentre as doenças, destaca-se a Sigatoka amarela da bananeira (Mycosphaerella musicola), responsável por causar redução na produção acima de 50%. O objetivo deste trabalho foi desenvolver e validar uma escala diagramática para avaliar a severidade da Sigatoka amarela da bananeira. A escala diagramática foi elaborada e validada com oito níveis de severidade (0,44; 5,43; 12,80; 20,22; 40,26; 60,20; 72,83 e 91,28%). A validação da escala envolveu a participação de 14 avaliadores sem experiência com o patossistema. Realizaram-se três avaliações, com intervalos semanais. Na primeira avaliação, foram apresentadas aos avaliadores, 50 imagens de folhas sintomáticas, e os valores de severidade foram estimados sem o auxílio de escala. Nas avaliações subsequentes, os avaliadores utilizaram a escala. Os dados foram analisados por dois métodos: regressão linear simples e coeficiente de concordância de Lin. Por meio da regressão linear simples, sem a escala, os valores do intercepto de 92,86% dos avaliadores diferiram significativamente de zero. Com o uso da escala, na primeira e segunda avaliações, houve redução na porcentagem de avaliadores com valores de intercepto significativos, para 57,14% e 28,57%. Por meio do coeficiente de concordância de Lin o fator de correção do desvio foi de 0,918 e 0,991, sem e com o uso da escala, respectivamente. O coeficiente de correlação de concordância de Lin, foi de 0,857 e 0,946, sem e com o uso da escala, respectivamente. Sem a escala, a maioria dos avaliadores superestimou a severidade da doença. Já com o uso da escala, houve elevada acurácia, precisão, repetibilidade e reprodutibilidade das estimativas. Portanto, recomenda-se a escala diagramática desenvolvida nesse estudo, para avaliar a Sigatoka amarela da bananeira.Banana (Musa spp.) is cultivated in all Brazilian regions, being the banana one of the most consumed fruits and of significant socioeconomic importance for the country. In areas with low productivity, the main associated factors are the lack of technification and inadequate management of pests and diseases. Among the diseases, the Yellow sigatoka leaf spot (Mycosphaerella musicola) stands out, responsible for causing a reduction in production above 50%. The objective of this work was to develop and validate a diagrammatic scale to assess the severity of the Yellow sigatoka leaf spot. The diagrammatic scale was developed and validated with eight severity levels (0.44, 5.43, 12.80, 20.22, 40.26, 60.20, 72.83 and 91.28%). Scale validation involved the participation of 14 raters without experience with the pathosystem. Three assessments were carried out at weekly intervals. In the first evaluation, 50 images of symptomatic leaves were presented to the evaluators, and the severity values were estimated without the aid of the scale. In subsequent evaluations, the evaluators used the scale. Data were analyzed by two methods: simple linear regression and Lin's coefficient of agreement. By means of simple linear regression, without the scale, the intercept values of 92.86% of the evaluators differed significantly from zero. With the use of the scale, in the first and second evaluations, there was a reduction in the percentage of evaluators with significant intercept values, to 57.14% and 28.57%. Using Lin's coefficient of agreement, the deviation correction factor was 0.918 and 0.991, without and with the use of the scale, respectively. Lin's correlation coefficient of agreement was 0.857 and 0.946, without and with the use of the scale, respectively. Without the scale, most raters overestimated the severity of the disease. With the use of the scale, there was high accuracy, precision, repeatability and reproducibility of estimates. Therefore, the diagrammatic scale developed in this study is recommended to assess the banana yellow Sigatoka.Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNP
Space-temporal analysis of yellow sigatoka in banana using remote sensing and geostatistics
No full textYellow Sigatoka leaf spot, caused by Pseudocercospora musae (Mycosphaerella musicola), is among the diseases that most affect banana crop. The disease progress occurs in both time and space, and the Remote Sensing sciences and the space-time Geostatistics provide support for the analysis of this dynamic process. Therefore, the objective of this study was to perform the spatiotemporal prediction of yellow Sigatoka at different times, to calculate and evaluate vegetation indices derived from the Enhanced Thematic Mapper Plus (ETM +) sensor, from the Landsat 7 satellite, to infer about the disease occurrence, to evaluate the existence of spatial and temporal correlation between data obtained by the sensor and data in situ, and finally to analyze the spectral signature of the plant affected by the disease. The first study used images from the Landsat 7 satellite, ETM + sensor, with atmospheric correction method Dark Object Substraction 1 (DOS1) and Second Simulation of Sattelite Signal in the Solar Spectrum (6S). Normalized Difference Vegetation Index (NDVI), Green Standard Difference Vegetation Index (GNDVI) and Normalized Difference Water Index (NDWI) were calculated. In the spectral signature related to the months of September and October, the mid-infrared region allowed the characterization of the disease in the plant. The NDVI and GNDVI indices showed differences in the atmospheric correction and in relation to the disease the NDWI presented better result. In the second study, Gneiting's separable spatiotemporal, Double Exponential, and non-separable covariance models were tested with the Weight Least Squares (WLS), Restricted Maximum Likelihood (REML) and Likelihood Pairwise methods. The Gneiting‟s non-separable model, WLS adjustment method, in which the trend was modeled, allowed to reduce as uncertainties of spatial and temporal prediction of the disease, as well as to characterize the pattern of monocycle temporality of the disease.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A Sigatoka amarela, cujo agente etiológico é o Pseudocercospora musae (Mycosphaerella musicola), está entre as doenças que mais afetam a bananeira. O progresso da doença ocorre tanto no tempo como no espaço e as ciências Sensoriamento Remoto e Geoestatística espaço-tempo oferecem suporte para a análise desse processo dinâmico. Portanto, o objetivo deste trabalho foi realizar a predição espaçotemporal da Sigatoka amarela em diferentes épocas, calcular e avaliar índices de vegetação derivados do sensor Enhanced Thematic Mapper Plus (ETM+), satélite Landsat 7, para inferir sobre a ocorrência da doença, avaliar a existência de correlação espacial e temporal entre dados obtidos pelo sensor e dados in situ e, por fim, analisar a assinatura espectral da planta afetada pela doença. No primeiro estudo, foram utilizaradas imagens do satélite Landsat 7, sensor ETM+, com correção atmosférica método Dark Object Substraction 1 (DOS1) e Second Simulation of Sattelite Signal in the Solar Spectrum (6S). Foram calculados os índices Vegetação da Diferença Normalizada (NDVI), Índice de Vegetação da Diferença Normalizada no Verde (GNDVI) e Índice de Água de Diferença Normalizada (NDWI). Na assinatura espectral referente aos meses de setembro e outubro, a região do infravermelho médio possibilitou a análise das características da doença na planta. Os índices NDVI e GNDVI mostraram diferenças na correção atmosférica e em relação à doença o NDWI foi o que apresentou melhor resultado. No segundo estudo, os modelos de covariância espaçotemporais separáveis, Duplamente Exponencial, e não separáveis, de Gneiting, foram testados com os métodos de ajuste Weight Least Squares (WLS), Restricted Maximum Likelihood (REML) e Likelihood Pairwise. O modelo não separável de Gneiting, método de ajuste WLS, em que a tendência foi modelada, permitiu reduzir as incertezas de predição espacial e temporal da doença, bem como caracterizar o padrão espaçotemporal do monociclo da doença
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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