1,720,958 research outputs found
Meiofauna and nematofauna composition and biodiversity in the enclosed seas of Taranto (Italy)
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The diversity of Indian Ocean Heterotardigrada
No full textInformation about Indian Ocean tardigrades is quite scarce and in most cases refers to species in coastal coralline sediment and occasionally in abyssal mud. The present data concern species found in the intertidal sand of Coco and La Digue Islands in the Seychelles, previously unsampled for tardigrades, as well as species in subtidal sediment found at depths ranging between 1 and 60 m off the shores of the Maldive Atolls. These sediments are all very similar and consist of heterogeneous coralline sand, moderately or scarcely sorted. Sixteen species (three new to science) were found in the Seychelles, belonging to Renaudarctidae, Stygarctidae, Halechiniscidae, Batillipedidae and Echiniscoididae. Diversity and evenness data are also interesting, with maximum values of H' = 2.59 and of J = 0.97. In the Maldives 25 species were found (two new to science) belonging to Neostygarctidae, Stygarctidae, Halechiniscidae and Batillipedidae. Such a number of species, despite the low percentage of tardigrade fauna (only 0.6% of the total meiofauna), contributes to the high values of both diversity and evenness, with H' ranging between 1.5 and 2.6 and J between 0.6 and 1. The Indian Ocean tardigrade fauna currently numbers 31 species of Arthrotardigrada and 2 species of Echiniscoidida. In the present study, Arthrotardigrada are the most abundant and all the families are present except Neoarctidae. Halechiniscidae is present with all the sub-families (except Euclavartinae), thus contributing to the high diversity values. Furthermore, 18 species, representing more than 50% of the total marine tardigrade fauna, are new records for the Indian Ocean, including five species new to science
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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