1,720,981 research outputs found
Contrasting tectonic records in pre-Alpine metabasites of the Southern Alps (Lake Como, Italy)
No full textThe microstructural and petrological evolution of pre-Alpine metabasites from the Southern Alps allow to compare the P-T-d-t paths in the three adjacent basement zones of Domaso-Cortafo (DCZ), Dervio-Olgiasca (DOZ) and Monte Muggio (MMZ) for delineating the Variscan and post-Variscan evolutions of the deep and middle crust in the Lake Como region. The DCZ rocks show a P-T evolution characterized by a pre-D2 almost isobaric T-increase up to T = 560-650°C and P = 0.7-1.1 GPa during D2 deformation. A decompressional cooling characterizes the exhumation during which D3 deformation took place. The DOZ amphibolites show a P-T-d-t path in which the physical metamorphic conditions predating D2 were: T = 530-590°C and P = 0.8-1.2 GPa. D2 deformation developed during a decompression accompanied by a T-increase (T = 630-710°C and P = 0.4-0.7 GPa). The final exhumation stage is characterized by cooling occurring during a slight decompression (T < 400°C and P≥0.2 GPa). This P-T evolution of the amphibolites well matches the P-T-d-t path of the surrounding metapelites. The DOZ and DCZ tectono-thermal evolutions, compared with that of the MMZ, evidentiate that three different tectono-metamorphic units constitute thin interleaved crustal slices. The DCZ and MMZ P-T evolutions may represent the thermal record of the Variscan subduction-collision and subsequent uplift, whereas the DOZ P-T evolution occurred under a higher thermal regime, consequent to a Permo-Triassic crustal thinning. The complex stacking geometry of such thin portions of deep crust, exhumed in different times and under different thermal conditions, requires a polyphase juxtaposition history. (C) 2000 Elsevier Science Ltd. All rights reserved
Map of foliation trajectories and metamorphic imprint: A tool for individuating tectonometamorphic units in the Southalpine basement (Como Lake area)
No full textNew structural mapping and metamorphic evolution of the Domaso Cortafò Zone (Southern Alps - Lake Como)
No full textMaps of foliation trajectories and metamorphic imprints: a tool to individuate tectono-metamorphic units in the Southalpine metamorphic basement.
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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
The role of structural and metamorphic memory in the distinction of tectono-metamorphic units : the basement of the Como Lake in the Southern Alps
No full textThe concept of 'metamorphic field gradient' applied to the lithologically homogeneous deep crust of the Southern Alps suggests the existence of two metamorphic units. The comparison of P-T-d-t paths, derived in adjacent portions of this basement and supported by a continuous foliation trajectory map helps to distinguish three tectono-metamorphic units, corresponding to the Domaso-Cortafo, Dervio-Olgiasca and Monte Muggio zones. The degree of granular scale reorganisation of the prevailing planar fabric is considered in the three zones together with the relative chronology of the structural imprints and the metamorphic environments in which they developed. This approach emphasizes that the dominant metamorphic imprint of each unit coincides with that of the most pervasive fabric at the regional scale when the degree of fabric evolution is sufficiently high, and not with the T(max)-P(Tmax) recorded in each tectono-metamorphic unit. In terrains that underwent polyphase deformation and metamorphism the 'metamorphic field gradient' concept cannot therefore be utilised to discriminate tectono-metamorphic units. (C) 2000 Elsevier Science Ltd. All rights reserved
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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