1,721,032 research outputs found
Environmental control on the end of the Dolomia Principale/Hauptdolomit depositional system in the central Alps: Coupling sea-level and climate changes
Full text linkThe Norian in the Western Tethys is characterised by the deposition of early-dolomitised inner platform facies (Dolomia Principale/Hauptdolomit, DP/HD), bordered on the landward side by terrigenous coastal deposits (Keuper) and on the seaward side by calcareous backreef and reefal facies (Dachstein Limestone) passing basinward to open-sea sediments (Hallstatt facies). The inner carbonate platform is locally (Lombardy Basin, Carnic Alps, Central Austroalpine) dissected by normal faults leading to the development of intraplatform troughs.
Close to the Norian-Rhaetian boundary, sedimentation records an abrupt environmental change both on platform top and basins all over the Western Tethys (e.g. Western Carpathians, Transdanubian Range, Alps, Central Apennine). The top of the Dolomia Principale locally emerged, reflecting a major eustatic sea-level fall. Emersion is recorded in favourable settings by the development of polycyclic paleosols up to 30 m thick. In the Norian intraplatform basins, the succession is capped by 4 to 8 m of thin-bedded, fine-grained limestones yielding abundant remnants of fishes and terrestrial reptiles. Fossil concentration as well as sedimentological features is indicative of reduced sedimentation rates due to decreased carbonate production, induced by the emersion of the platform top. The sea-level fall was followed by deposition of mixed fine-grained siliciclastic-carbonate successions (e.g. Riva di Solto Shale, Kossen beds, "Rhaetavicula contorta beds", Fatra Formation).
Stratigraphic evidence indicates a dry climate in the Western Tethys during the Norian, as indicated by the presence of evaporites (Burano, Apennine) and arid to semi-arid coastal to playa settings (Upper Keuper, Germany). In contrast, the basal layers of the basinal shales show evidence of wet climate.
The end of the Norian depositional system records two different phenomena: (1) an important sea-level fall was responsible for the emersion of the platform top and deposition of a condensed horizon in the basins: and (2) transition from dry to humid climate. The observed evolution is explained with a global cooling which caused the rapid sea-level fall responsible for the abrupt end of the DP/HD depositional system and the shift of the boundary between arid and temperate climate belts, which modified the distribution and amount of rainfall, triggering the deposition of shales along the Western Tethys margin
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
Significato adattativo del polimorfismo per la glutamminico-ossalacetico transaminasi-1 nella zanzara Culex pipiens
No full textVariations 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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