1,720,959 research outputs found
Regional mantle heterogeneity regulates melt production along the Réunion hotspot-influenced Central Indian Ridge
No full textTo ascertain factors controlling melt production along a typical distal, 'hotspot-interacting' mid-ocean ridge, we investigated the extent and distribution of both plume-related and plume-unrelated basalt from the central Indian ridge (CIR) between 15°S and 20°S. Comprehensive geochemical data of fresh-quenched volcanic glasses and basalts were used. Variation of Sr, Nd, and Pb isotopic compositions and Nb/Zr, Ba/Nb, and Ba/La content were interpreted by mixing of three melt end members: the Indian depleted MORB mantle derived melt; radiogenic and enriched melt derived from source mantle for Rodrigues Ridge and the intermediate series of Mauritius Island (RE2, radiogenic enriched component 2); and radiogenic but depleted melt derived from source mantle for Gasitao Ridge (RD, radiogenic depleted component). On the basis of quantitative mantle melting and melt mixing model, results show that sources for RE2 and RD are geochemically distinct from those of the Réunion plume (RE1, radiogenic enriched melt component 1). Moreover, the geochemical variation of MORB of 15°S to 20°S is unrelated to contamination of the upper mantle by the Réunion plume. These results suggest strongly that plume-unrelated heterogeneity is widespread throughout the upper mantle. The chemical characteristics of RE2 are remarkably pronounced in basalt from the central portion of ridge segment 16 around 18°S, suggesting substantial magma production. The influence of RE2 decreases along with decreasing magma production to the north, and is only slightly identifiable in basalt from the northern part of segment 18. Although the influence of RE2 decreases somewhat to the south, basalts with extreme RE2 signature were produced in the center of segment 15 around 19°S, where magma production is high. In contrast to RE2, the geochemical signature of RD in basalt is geographically limited to two localities: the south end of segment 18 and the center of segment 15. However, these observations reveal that both RE2 and RD contribute strongly to magma production on segment 15. Results show that melting of ancient recycled plate materials with a low melting point regulates voluminous magma production along the CIR
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
Petrology of the basalts of the Central Indian Ridge and regional variations of MORBs along the eastern part of the Southwest Indian Ridge
No full textDispelling 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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