1,720,973 research outputs found
Characters Selection of Leaf Morphology in Some Families (Tree Habit) In Sumatra Region for Species Identification
Full text linkIdentification is a basic activity and one of primary objective on systematic. For plant biodiversity studies,it was the first steps that researcher performed before studying any topics in the research area. Unfortunately, species identification is usually a time consuming activity. One of the main objectives of this study was to obtain a set of leaf morphology characters that were useful and efficient enough for species identification, especially on the tree habits group in order to reduce time consuming for the identification species. All of the leaf morphology characters were selected by correlation coefficient and separation coefficient values. Besides of that, the stability, simplicity and validity of the characters were also part of concern. The characters that had high value of separation coefficient and low value of correlation coefficient would be added one by one as in their rank, until the value of the combination separation coefficient was equal to 1 (100%). The result of this study suggested that 30 from 92 characters of leaf morphology were recommended as a set of characters that useful and efficient enough for species identification
IMPACT OF STAND STRUCTURE TO THE DIVERSITY OF TREE SAPLING IN RUBBER AGROFOREST SYSTEM
Full text linkThe study of stand structure of rubber agroforest system and its effect on tree sapling diversity was carried out in Bungo District, Jambi Province from August 2004 to August 2005. Basal area (BA) and tree density were surveyed using variable-area transect method. Tree sapling species was surveyed using standard plots combined with circular elementary subplots laid along 60 m transect line. The result shown that BA and tree density of rubber agroforest system were lower significantly with forest at the diameter class 30 cm, but at the diameter class 30 cm there were not differ significantly. PCA analysis shown there was a positive correlation between BA non rubber tree with the species diversity and richness indices of tree sapling in rubber agroforest system and there was no correlation between density of non rubber tree and the indices. However, in the forest, BA and tree density were have a negative correlation with the species diversity and richness indices of tree sapling
Potency Study of N-Hexane Extracts of Black Plum (Syzygium cumini (L.) Skeels) in the Inhibitation Growth of Salmonella typhi and Candida sp.
Full text linkN-hexane extracts of the bark from black plum (Syzygium cumini (L.) Skeels) showed activity against Salmonella typhi. Meanwhile, the result showed that N-hexane was not able to inhibit the growth of Candida sp. The research was done at Microbiology laboratory, Biology Department Faculty of Mathematics and Science, Syiah Kuala University. The barks of black plum were collected from Aceh Besar District. The extraction method for black plum used maceration with N-hexane and than concentrated in rotary evaporator. The disc diffusion method used to screen the antimicrobial activity with 20 %, 30 %, 40 % dan 50 % concentration
Potency Study of N-Hexane Extracts of Black Plum (Syzygium cumini (L.) Skeels) Intheinhibitation of Growth Salmonella typhi and Candida sp.
Full text linkN-hexane extracts of the bark from black plum(Syzygium cumini (L.) Skeels) showed activity againtSalmonella typhi. Meanwhile, the result showed that N-hexane was not able to inhibit the growth of Candida sp. The research was done at Microbiology laboratory, Biology Department Faculty of Mathemathics andScience, Syiah Kuala University. The bark of black plum were collected from Aceh Besar District. The extraction method for black plum used maceration with N-hexane and than concentrated in rotary evaporator. The disc diffusion method used to screen the antimicrobial activity with 20 %, 30 %, 40 % dan 50 % concentration
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
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