1,720,990 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
Risk assessment of botanicals and botanical preparations intended for use in food and food supplements: Emerging issues
No full textAt present there is a growing interest for use of botanicals and botanical ingredients in medicines, for teas or in foods and in food supplements. In addition, a number of plant-derived food items form an integral part of regular human diets. Currently, there is an increasing awareness among safety experts and regulators of risks associated with the use of botanicals and botanical ingredients in food including food supplements. It is becoming clear that ¿natural¿ does not equal ¿safe¿ and that, in modern society, adverse health effects can occur as a result of (mis)use. With the growing awareness of these issues efforts to ensure safety of botanicals and botanical ingredients are also increasing. Several guidance documents on safety assessment of botanicals and botanical preparations to be used as ingredients in food and food supplements have been published, although, at present, relevant legislative frameworks and guidances for risk assessment are not established yet. Furthermore, when defining possible guidance documents for risk assessment of botanicals, several issues emerge that need to be developed beyond the present state-of-the-art. The present paper describes some of the issues to be considered and developed to a further extent to improve risk assessment of botanicals and botanical preparations, illustrated by examples based on some allylalkoxybenzenes. It is concluded that, for an improved and more accurate future risk assessment of botanicals, it is necessary to further develop and validate: (i) the use of the margin of exposure (MOE) concept for compounds that are both genotoxic and carcinogenic; (ii) new ways to quantify and incorporate matrix effects into risk assessment strategies; (iii) the use of analytical chemistry approaches, enabling complete chemical characterisation of complex mixtures. Defining new approaches in risk assessment would be in line with the inspiring attitude of the late Professor Robert Kroes, who, for example by supporting the threshold of toxicological concern (TTC) concept, was a pioneer for development and implementation of new paradigms in the field of risk assessment and food safety
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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