1,720,959 research outputs found
Desarrollo de un sistema de alertas agroclimáticas tempranas para la chinche de los pastos, Collaria scenica, en la sabana de Bogotá
Get PDFSe desarrolló un sistema de alertas agroclimáticas tempranas para la chinche de los pastos, Collaria scenica, en la sabana de Bogotá a partir del análisis del comportamiento de su población, con los escenarios de cambio climático para los años 2020 y 2030 generados por el modelo global HadCM3 y el modelo regional PRECIS, bajo los escenarios de tipo B2, A2 y A1B, según estudios del IDEAM, y para condiciones de variabilidad climática predominantes cuando se presenta un fenómeno de El Niño-Oscilación sur (ENSO). Usando datos de campo tomados semanalmente desde mayo 2009 a noviembre 2010 en Funza y datos de la estación meteorológica Tibaitatá en Mosquera, se estimó las variables agroclimáticas significativas en la presencia de ninfas y adultos de la chinche a través de un modelo de regresión lineal múltiple. La temperatura máxima y mínima, precipitación y evapotranspiración mostraron mayor significancia. Así, se analizó la respuesta de estas variables a los cambios de sus promedios en escenarios futuros y a las fluctuaciones de la temperatura superficial del mar y su impacto en el aumento o disminución de la plaga. / Abstract. An early warning agroclimatic system was developed for grass bug, Collaria scenica, from studying the behavior of the population, related with climate change scenarios for 2020 and 2030, generated by the HadCM3 global model and the model PRECIS regional under scenarios B2, A2 and A1B, according to studies by IDEAM, and the conditions determined by the El Niño-Southern Oscillation (ENSO) phenomenon. Using field data weekly from May 2009 to November 2010 in Funza and weather station data Tibaitatá in Mosquera, agro-climatic variables were considered significant the presence of nymphs and adults of the bug through a multiple linear regression model. The temperature minimum and maximum rainfall and evapotranspiration showed more significant. Thus, it was analyzed the response of these variables to changes in their future scenarios averages and fluctuations Sea surface temperature and its impact on increase or decrease of the plague.Maestrí
Implementation of a method for the spatial anaysis of global climate model outputs in mountainous areas considering the altitudinal gradient
No full textLas salidas de las simulaciones de la temperatura media superficial del aire del MCG CCSM4 del centro de
investigación NCAR fueron espacializadas considerando un ajuste con el gradiente altitudinal para la región
Andina de Colombia usando una función de regresión lineal. El modelo fue seleccionado previamente, a partir de la comparación de los datos de las elevaciones de los modelos disponibles de la base de datos CMIP5 con respecto a las elevaciones reales de las estaciones meteorológicas ubicadas en la zona de estudio. Los mapas fueron generados mediante una técnica para reducir los valores de la variable a un nivel de referencia y luego establecer su distribución vertical para cada grilla implementando el modelo de elevación digital (DEM). Los resultados de las simulaciones del modelo CCSM4 ajustados consiguen valores mucho mas cercanos a los reales, lo que permite construir análisis climáticos más robustos y por tanto generar proyecciones futuras con menor incertidumbre.The air temperature outputs from CCSM4 simulations of The National Center for Atmospheric Research (NCAR) were interpolated considering the altitudinal gradient for the Colombian Andina region with a linear regression function. The model was selected previously through comparing available data elevations models in the CMIP5 project dataset regarding the actual elevations of meteorological stations in the study area. The maps were generated using a technique to reduce the temperature values to a reference level and then it is established the vertical distribution for each pixel implementing the digital elevation model (DEM). The CCSM4 simulations adjusted got values more near to real data, allowing to build more robust climate analyzes and therefore generate less uncertainty with future projections
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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