1,720,974 research outputs found
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
Anais do IV Simpósio de Zoologia
No full textO IV Simpósio de Zoologia foi realizado entre os dias 6 e 10 de agosto de2018 em Curitiba, pelo Programa de Pós-Graduação em Zoologia da UniversidadeFederal do Paraná. Ao longo do evento foram ofertados Minicursos, Palestras euma Mostra científica com apresentações de pós-graduandos do programa eestudantes e profissionais de outras instituições. O evento inteiramente gratuito foi realizado com apoio de várias instituições apoiadoras (vide capa), e a colaboração voluntária de parte dos participantes. As inscrições e submissões de resumos foram pelo site do evento https://4simposiozoologia2.wixsite.com/simposio com a data limite de 30 de junho e o prazo de emissão dos pareceres pela Comissão de resumos e certificados encerrou-se no dia 20 de julho
Clustering methods: evaluation and application for study of genetic divergence in garlic accessions
No full textEste estudo teve por objetivo avaliar, quanto a consistência do agrupamento, os
métodos de agrupamentos hierárquicos UPGMA e Ward e os de otimização de
Tocher e Tocher modificado, pela aplicação da análise discriminante de Fisher
aos grupos obtidos com cada método, em estudo da divergência genética entre
acessos de alho, identificando também os acessos mais dissimilares. Os
agrupamentos foram realizados com base na distância generalizada de Mahalanobis, que também permitiu quantificar a importância relativa dos caracteres. Os acessos que apresentaram maior dissimilaridade foram os acessos 13 (BGH 4505) e 61 (BGH 5958), principalmente em relação ao peso médio do bulbo e produtividade. Os métodos de Tocher modificado, UPGMA e algoritmo de Ward apresentaram resultados concordantes entre si quanto a formação dos grupos. No entanto, pela análise discriminante de Fisher aplicada aos grupos dos métodos hierárquicos (UPGMA e Ward) observou-se as menores taxas de erro aparente, sendo, portanto, os métodos mais consistentes para o estudo da diversidade genética de acessos de alho.This study aimed to assess, as the consistency of the grouping, hierarchical clustering methods UPGMA and Ward and optimization Tocher and modified Tocher by application of Fisher discriminant analysis in groups obtained with each method in the study of genetic divergence among garlic accessions, also identifying the most dissimilar access. The groupings were based on the Mahalanobis distance, which also allowed to quantify the relative importance of characters. The accessions with the highest dissimilarity accesses were 13 (BGH 4505) and 61 (BGH 5958), especially in relation to the average weight of the bulb and productivity. Modified Tocher methods, UPGMA and Ward algorithm presented results agree with each other and form groups. However, the Fisher discriminant analysis applied to groups of hierarchical methods (UPGMA and Ward) showed the lowest apparent error, therefore, more consistent methods for studying the genetic diversity of garlic accessions
Teste da covariância genética via razão de produtos cruzados médios
No full textWhen a genetic factor is being studied for more than one response variable, estimates of the genetic covariances are essential, specially in breeding programs. In a genetic covariance analysis, genetic and residual mean cross-products are obtained. Stochastically, to quantify the magnitude of the joint variation of two response variables due to genetic effect with respect to the variation due to residual effect may allow one to make inferences about the significance of the associated genetic covariance. In this study it is presented tests of significance for genetic covariance upon a twofold way: tests that take into account the genetic and environmental effects and tests that only consider the genetic information. The first way refers to tests based on the mean cross-products ratio via nonparametric bootstrap resampling and Monte Carlo simulation of Wishart matrices. The second way of testing genetic covariance refers to tests based on adaptation of Wilks\' and Pillai\'s statistics for evaluating independence of two sets of variables. For the first type of tests, empirical distributions under the null hypothesis, i.e., null genetic covariance, were built and graphically analyzed. In addition, the exact distribution of mean cross-products ratio obtained from variables normally distributed with zero mean and finite variance was examined. Writing computational algorithms in R language to perform the proposed tests was also an objective of this study. Only under certain conditions does the probability density function of the product of two random Gaussian variables approximate a normal curve. Therefore, studying the distribution of a mean cross-products ratio as a quotient of two Gaussian variables is not suitable. Tests based on mean cross-products ratio are related to both the value of the genetic covariance and the magnitude of the latter relative to the residual covariance. And both approaches (bootstrap and simulation) are more sensitive than the tests based only on genetic information. The performance of the tests based on mean cross-products ratio is related to the quality of the original data set in terms of the MANOVA assumptions, and the test statistic does not depend on the estimation of the matrix of genetic covariances ΣG. The adaptation of Wilks\' and Pillai\'s statistics can be used to test the genetic covariance. Their approximations to a χ21 distribution were checked and the accuracy of their inferences is related to the quality of G.Quando um fator genético está sendo estudado em mais de uma variável de resposta, estimativas das covariâncias genéticas são essenciais, especialmente para programas de melhoramento. Em uma análise de covariância genética, produtos cruzados médios devido ao efeito genético, a partir do qual é obtida a covariância genética, e devido ao efeito residual são obtidos. Estocasticamente, quantificar a magnitude da variação conjunta de duas variáveis resposta devido ao efeito genético em relação à variação devida ao efeito residual pode permitir realizar inferências sobre a covariância genética associada. Neste estudo são apresentados testes de significância para a covariância genética de duas formas: testes que levam em conta os efeitos genéticos e ambientais (ou residuais) e testes que consideram apenas a informação genética. A primeira forma refere-se testes baseados na razão de produtos cruzados médios via bootstrap não paramétrico e simulação de matrizes Wishart pelo método de Monte Carlo. A segunda maneira de testar a covariância genética refere-se a testes com base em uma adaptação das estatísticas de Wilks e Pillai para avaliar a independência de dois conjuntos de variáveis. Para o primeiro tipo de testes, as distribuições empíricas sob a hipótese nula, ou seja, covariância genética nula, foram construídas e analisadas graficamente. Além disso, foi feito um estudo analítico da distribuição da razão de produtos cruzados médios obtidos a partir de variáveis normalmente distribuídas com média zero e variância finita. Escrever algoritmos computacionais em linguagem R para realizar os testes propostos também foi um dos objetivos deste estudo. Apenas sob certas condições a função de densidade de probabilidade do produto de duas variáveis aleatórias gaussianas aproxima-se da curva normal. Por conseguinte, o estudo da distribuição da razão de produtos cruzados médios como um quociente de duas variáveis gaussianas não é adequado. Os testes baseados na razão de produtos cruzados médios estão relacionados tanto com o valor da covariância genética quanto com a magnitude desta em relação à covariância residual. Ambas as abordagens (bootstrap e simulação) mostraram-se mais sensíveis do que os testes baseados apenas nas informações genéticas. O desempenho dos testes baseados na razão de produtos cruzados médios está relacionado à qualidade dos dados originais em termos das pressuposições da MANOVA, e a estatística de teste não depende da estimação da matriz de covariâncias genéticas ΣG. A adaptação das estatísticas de Wilks e Pillai pode ser usada para testar a covariância genética. As aproximações à distribuição Χ21 foi verificada. A precisão de suas inferências está relacionada a qualidade da matriz G
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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