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Occurrence of high-Al N-MORB along the Easternmost Southwest Indian Ridge
Get PDFOne of the deepest and slowest part of the mid-ocean-ridge system lies within the easternmost part of the Southwest Indian Ridge between 61°E and 69° E. In this region, a distinctive sea-floor terrain characterized by high-relief segments separated by long, deep tectonized sections shows a predominance of tectonic over magmatic extensional processes, suggesting an unstable and weak, but locally focalized magma supply. Other features of this section include the absence of long-lived transforms, thick lithosphere, high upper mantle seismic wave velocities and thin oceanic crust (4-5 km).
When compared to other ridge segments, most MORB erupted along this section distinguish themselves by their higher Na2O, Sr and Al2O3 compositions, very low CaO/Al2O3 ratios relative to TiO2 and depleted heavy rare-earth element (REE) distributions. Another peculiar feature is their subparallel LREE enriched patterns. The high-Al-MgO magma type erupted periodically around the ridge system is also found in this region at 61.93°E. These lavas are characterized by high Al2O3 (> 17 wt. %), MgO (> 8.8 wt. %) and FeO contents, low SiO2 (< 49 wt. %) and Na2O and very low TiO2 (< 1 wt. %), and a LREE depleted pattern compared to the main population. At slightly lower MgO, sporadically, two other dredges located at 63.36-63.66°E share some of these distinct compositional characteristics. As a whole, these lavas are the most depleted in highly incompatible elements, but are also characterized by an offset toward lower MREE/HREE ratios relative to the main population.
These peculiar basalts are not parental to the more common lower MgO compositions and cannot be related to them by fractional crystallization alone. Instead, their major element features, and the occasional presence of positive Eu and Sr anomalies might indicate assimilation of plagioclase cumulates, while their offset in MREE/HREE might require a multistage melting evolution with an earlier event in the garnet stability field
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
Prospective Terre Solide 2021-2025
No full textBilan et Prospective 2021-2025 de la Commission spécialisée Terre Solide de l‘Institut National des Sciences de l’UniversSynthèse des ateliers, des forums préparatoires et du colloque de Paris 19-21 octobre 2020Sous la coordination de Bruno Scaillet, Président de la CSTS, Eric Humler puis Stéphane Guillot,Directeur Adjoint Scientifique du domaine TS-INS
Prospective Terre Solide 2021-2025
No full textBilan et Prospective 2021-2025 de la Commission spécialisée Terre Solide de l‘Institut National des Sciences de l’UniversSynthèse des ateliers, des forums préparatoires et du colloque de Paris 19-21 octobre 2020Sous la coordination de Bruno Scaillet, Président de la CSTS, Eric Humler puis Stéphane Guillot,Directeur Adjoint Scientifique du domaine TS-INS
Prospective Terre Solide 2021-2025
No full textBilan et Prospective 2021-2025 de la Commission spécialisée Terre Solide de l‘Institut National des Sciences de l’UniversSynthèse des ateliers, des forums préparatoires et du colloque de Paris 19-21 octobre 2020Sous la coordination de Bruno Scaillet, Président de la CSTS, Eric Humler puis Stéphane Guillot,Directeur Adjoint Scientifique du domaine TS-INS
Prospective Terre Solide 2021-2025
No full textBilan et Prospective 2021-2025 de la Commission spécialisée Terre Solide de l‘Institut National des Sciences de l’UniversSynthèse des ateliers, des forums préparatoires et du colloque de Paris 19-21 octobre 2020Sous la coordination de Bruno Scaillet, Président de la CSTS, Eric Humler puis Stéphane Guillot,Directeur Adjoint Scientifique du domaine TS-INS
Prospective Terre Solide 2021-2025
No full textBilan et Prospective 2021-2025 de la Commission spécialisée Terre Solide de l‘Institut National des Sciences de l’UniversSynthèse des ateliers, des forums préparatoires et du colloque de Paris 19-21 octobre 2020Sous la coordination de Bruno Scaillet, Président de la CSTS, Eric Humler puis Stéphane Guillot,Directeur Adjoint Scientifique du domaine TS-INS
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