1,720,971 research outputs found
Anatomia da madeira de quatro espécies de Aspidosperma Mart. & Zucc. Comercializadas no estado do Pará, Brasil
No full textA madeira do gênero Aspidosperma é usada com frequência no mercado madeireiro amazônico, ocasionando pressão sobre as suas espécies. O objetivo do presente trabalho foi caracterizar anatomicamente o lenho de A. carapanauba, A. desmanthum, A. excelsum e A. spruceanum, visando contribuir com a identificação e a distinção das espécies. Todas as espécies apresentaram vasos solitários, difusos, com placa de perfuração simples e pontoações parênquimo-vascular e raio-vasculares alternas. Em nível macroscópico, as espécies são semelhantes devido à textura fina, enquanto que microscopicamente, a principal diferença é o parênquima axial: (i) apotraqueal difuso em agregados em A. carapanauba, A. excelsum e A. spruceanum; (ii) paratraqueal aliforme losangular curto em A. desmanthum. Os raios são unisseriados a trisseriados em A. spruceanum e A. carapanauba; corpo formado por todas as célulasprocumbentes, enquanto queem A. excelsum e A. desmanthum, o corpo é formado por células procumbentes e uma camada marginal de células quadradas ou eretas
Agrupamento de madeiras amazônicas com base nas características macroscópicas e físicas
No full textThe anatomy gives wood is a fundamental piece in the fight against illegal trade in wood, and currently this tool seeks new methodologies so that allied traditional techniques, speed and optimize the identification of wood. Given this, the present work aims to characterize macroscopically the wood of 15 Amazonian woods and to group these individuals through multivariate statistical analysis. The woods used come from the xylotheque of the Faculty of Forestry Engineering, UFPA - Campus Altamira. The traditional techniques used in wood anatomy were used and submitted to multivariate cluster analysis in order to group the species, based on their physical and anatomical characteristics. The most commonly found anatomical structures were diffuse apatracheal and aliphatic paratracheal axial parenchyma, each with 9 individuals. The Fabaceae family had the most anatomical variations between individuals and the genus Caryocar presented the most similar species. The 15 species were divided into 3 groups, formed by woods with more similar characteristics. All species were identified according to their anatomical characters and the 3 groupings performed presented coherence. Showing the viability of the method, combined with the traditional techniques of wood identification.A anatomia dá madeira é peça fundamental no combate ao comércio ilegal de madeira, e atualmente essa ferramenta, busca novas metodologias para que aliadas técnicas tradicionais, agilizem e otimizem a identificação da madeira. Diante disto, o presente trabalho tem como objetivo, caracterizar macroscopicamente o lenho de 15 madeiras amazônicas e realizar o agrupamento desses indivíduos através de analises estatísticas multivariadas. As madeiras utilizadas, são oriundas da xiloteca da Faculdade de Engenharia Florestal, UFPA – Campus Altamira. Utilizou-se as técnicas tradicionais usadas em anatomia da madeira e submetida a análise multivariada de conglomerado com a finalidade de agrupar as espécies, baseando-se nas suas características físicas e anatômicas. As estruturas anatômicas mais encontradas foram parênquima axial paratraqueal aliforme e apotraqueal difuso, cada um com 9 individuos. A família Fabaceae foi a que mais teve variações anatômicas entre os indivíduos e o gênero Caryocar foi o que apresentou caracteres das espécies mais similares entre si. As 15 espécies foram divididas em 3 grupos, formado pelas madeiras com características mais semelhantes. Todas as espécies foram identificadas segundo seus caracteres anatômicos e os 3 agrupamentos realizados apresentaram coerência. Mostrando a viabilidade do método, aliado as técnicas tradicionais de identificação de madeira
Análise da superfície foliar, como ferramenta para o agrupamento de espécies florestais amazônicas
No full textThe objective was to describe and systematize the leaf epidermis of 10 Amazonian forest species as tools to help the taxonomy and contributing to the technical-scientific knowledge. For this, the usual techniques in plant anatomy were performed to observe, besides the stomata width, length and frequency and submitted to statistics, applying: Tukey test, ANOVA, Cluster Analysis and Principal Component Analysis. It was observed that the adaxial and abaxial epidermis have heterodimen- tional cells, with varied shape and size, rounded and sinuous, in all studied species the stomata are anomocytic and only Spondias mombin is amphiestomatic. The species Dipteryx odorata and Virola surinamensis can be easily identified due to their guard cell ornamentation. The species Alexa grandiflora and Lecythis lurida have similar structures making identification difficult. The trichomes presented varied forms, being these the best parameter for identification and distinction.Objetivou-se descrever e sistematizar a epiderme foliar de 10 espécies florestais amazônicas, como ferramentas para auxiliar a taxonomia e contribuindo com o conhecimento técnico-científico. Para isso realizou-se técnicas usuais em anatomia vegetal, para observação, além da largura, comprimento e frequência dos estômatos e submetidos a estatística, aplicando: o teste de Tukey, ANOVA, Analise de agrupamento e Análise de Componentes Principais. Observou-se que a epiderme adaxial e abaxial apresenta células heterodimencionais, com forma e tamanho variados, arredondadas e sinuosas, em todas as espécies estudadas os estômatos são anomocíticos e somente a Spondias mombin é anfiestomatica. As espécies Dipteryx odorata e Virola surinamensis podem ser facilmente identificadas devido sua ornamentação da célula guarda, as espécies Alexa grandiflora e Lecythis lurida apresentam estruturas semelhantes dificultando a identificação. Os tricomas apresentaram formas variadas, sendo estes o melhor parâmetro para identificação e distinção
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
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