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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
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Thermal evolution of continental rifting in Corsica (France)
Get PDFDespite advances in understanding the structural development of magma-poor rift margins, the temporal and thermal evolution of lithospheric hyperextension during rifting remains poorly understood. In contrast to classic pure-shear models, multi-stage rift models that include depth-dependent thinning predict significant conductive crustal reheating during the necking phase due to buoyant rise of the asthenosphere. The Santa Lucia nappe of NE Corsica is an ideal laboratory to test for lower- and upper-crustal reheating as it preserves both Permian lower crust exhumed from granulitic conditions during Tethyan rifting and upper crust in contact with syn- and post-rift Mesozoic strata. This study uses novel zircon, rutile, and apatite LA-ICP-MS depth-profile U-Pb petro-and thermochronology coupled with garnet trace-element thermometry to constrain the syn-rift thermal evolution of this lower-crustal section during progressive lithospheric necking hyperextension, providing compelling evidence for significant early reheating due to depth-dependent thinning. Jurassic reheating is recorded in the footwall of the Belli Piani Shear Zone (BPSZ), where 200-180 Ma zircon U-Pb overgrowths on Permian core populations and preservation of stranded-diffusion profiles in garnets resorbed during D2 deformation imply that the dominant footwall fabric formed as a result of large-magnitude ductile thinning and reheating to ~800°C during Jurassic hyperextension. Conductive reheating of the upper crust in the lower hanging wall to 500-550°C due to either juxtaposition against the hot BPSZ footwall during lower crustal exhumation or wholesale crustal reheating due to conductive steepening of geothermal gradients during early rifting. Rapid post-reheating cooling in response to extensional unroofing of the footwall underscores the importance of ductile shearing and thinning during crustal hyperextension.
The results of this study suggest that the thermal evolution of magma-poor rifted margins mimics their multi-phase structural evolution, beginning with diffuse rifting and tectonic subsidence. Depth-dependent thinning triggers dramatic crustal reheating at the onset of necking and hyperextension, demonstrated here in the footwall and lower hanging wall of the Belli Piani subunit. Rapid cooling and exhumation of the lower crust and extreme crustal attenuation during continued hyperextension culminates in mantle exhumation, followed by thermal relaxation and subsidence to a steady-state thermal field coeval with the start of sea-floor spreading.Earth and Planetary Science
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Temporal constraints on progressive rifting of a hyper-extended continental margin using bedrock and detrital zircon (U-Th)/(Pb-He) dating, Mauléon Basin, western Pyrenees
Get PDFtextWhile the understanding of the structural, temporal, and thermal evolution of rifted continental margins has significantly evolved over the past several decades, critical outstanding questions remain, especially concerning the thermal evolution as well as the spatial and temporal intricacies of tectonically controlled sedimentation and sedimentary provenance during progressive rifting and hyper-extension. To constrain the proximal to distal tectonic, stratigraphic and thermal evolution of rifted continental margins, bedrock and detrital zircon (U-Th)/He (ZHe) and zircon U-Pb double dating techniques were applied to the Mauléon Basin of the western Pyrenees. This non-magmatic, asymmetric, hyper-extended rift basin formed during Early Cretaceous hyper-extension of Iberian lithosphere, as a result of lateral propagation of rifting in the Bay of Biscay, and experienced a limited magnitude of shortening during post-rift Pyrenean inversion. This resulted in the preservation of outcrops of sedimentary cover, upper and lower crustal sections, serpentinized lithospheric mantle, and the basic rift-relationships; making the Mauléon Basin an ideal locality to constrain rift-related processes during hyper-extension. Detrital zircon U-Pb analyses indicate that the proximal rift margin is primarily composed of pre-rift strata with Pan-African zircon U-Pb signatures and primary age peaks at ~615 Ma and ~1000 Ma. In contrast, the distal rift margin is composed of exhumed mid-lower crustal granulites, which have a similar Pan-African signature but with additional Variscan (Permian) overgrowths. Detrital zircon U-Pb analyses of syn- to post-rift strata indicate compartmentalized, local sourcing from the pre-rift strata in the proximal margin and the exhumed lower crust in the distal margin. Late syn- to post-rift strata show a shift to non-compartmentalized, regional sourcing from the proximal rift margin and hinterland. These observations are combined to present a sediment dispersal model for the progression of rifting. ZHe analyses shows preservation of two distinct age domains: an elevation-invariant age cluster at ~98 Ma, interpreted as rift-related cooling due to major exhumation along the SMD, and an elevation-invariant age cluster at ~50 Ma, interpreted as rapid cooling related to Pyrenean inversion. These results indicate the Mauléon Basin experienced early syn-rift heating prior to the exhumation of parts of the proximal domain to <180°C; these are the only localities that record rift-related timing. Based on thermochronometric modeling and burial estimates the syn-rift geothermal gradients in the necking domain were as high as ~80°C/km and ~80-100°C/km in the hyper-thinned domain. From the early syn-rift until Pyrenean inversion at ~50 Ma, most of the distal rift margin remained at temperatures >180°C. These observations of heating and high geothermal gradients are compared to geologic and numerical rifting models to give insight into preferred models for the rifting evolution of hyper-extended margins.Earth and Planetary Science
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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