1,721,046 research outputs found
Evolution of the northern tip of Afar triangle: Inferences from the Quaternary succession of the Dandiero â Massawa area (Eritrea)
No full textPiracy-controlled geometry of tide-dominated point bars: Combined evidence from ancient sedimentary successions and modern channel networks
No full textEstablishing critical comparisons between fluvial- and tidal-channel morphodynamics is a major goal in the study of coastal landscapes. Freely migrating meandering rivers are known to produce laterally extensive, sand-prone point-bar bodies which commonly exhibit width:thickness ratios up to 250. Meandering channels are widespread in tidal channel networks draining intertidal plains, where they exhibit planform dynamics similar to their fluvial analogues. However, tidal networks are characterized by a high channel density that likely hinders tidal meanders from migrating laterally for long distances without interacting with other channels. In order to better understand how the interaction between adjacent meandering channels controls the development of tide-dominated point bars, two point-bar bodies from the Eocene Castigaleu Formation (Spain) are investigated and compared with the geometry of a modern tidal point bar of the northern Venice Lagoon (Italy). The Eocene bars are characterized by a low width:thickness ratio (<30), interpreted as the result of premature deactivation of their parent-channel migration. Such deactivations were likely related to avulsive piracy operated by adjoining tide-dominated channels, and likely prevented the parent channel bend from depositing a laterally extensive, tabular sand body along its inner bank. This analysis is corroborated by direct time-lapse observations of similar dynamics in modern tidal networks, and from morphodynamic and sedimentological evidence from recent deposits of the Venice Lagoon. We conclude that, in densely drained tidal networks, meander bends often interact with adjacent channels, thereby triggering piracy events and premature channel abandonments that generate point-bar architectures distinct from those produced in fluvial meandering rivers
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
STRATIGRAPHIC AND CHRONOLOGIC FRAMEWORK OF THE UPPER MIOCENE CESSANITI SUCCESSION (VIBO VALENTIA, CALABRIA, ITALY)
Get PDFThis study revises the mammal-bearing stratigraphic succession of Cava Gentile, near Cessaniti (Calabria, southern Italy), with the aim of dating the Late Miocene fossiliferous succession by the integration of mammal biochronology with sedimentology, magnetostratigraphy and marine biostratigraphy. Since the first discovery of mammal remains at Cessaniti, the chronological framework of the sedimentary succession was based on the biochronological significance of the mammal assemblage and on the biostratigraphic characterisation of the capping unit. Chronological control of the sedimentary succession and the age range of the mammal faunal assemblage at Cessaniti is now possible by combining the mammal biochronological constraints with biostratigraphy and the characterisation of the magnetostratigraphy of the sedimentary succession. Our study allows the conclusion that: i) an overall transgressive trend is recorded at the late Tortonian succession of the Capo Vaticano area, with locally different depositional trends; ii) the late Tortonian transgression was punctuated by minor episodes of forced regression, as attested by soils and fluvial deposits intercalated within the Cava Gentile succession (documented here for the first time); iii) the relative sea level rises that characterised these sedimentation patterns allowed accumulation of marine and terrestrial fossils in specific transgressive horizons; iv) the combination of palaeomagnetic data and biostratigraphic analyses, together with the biochronological constraints offered by the Cessaniti mammal assemblage, allows the assignment of the basal unit of the Cessaniti (Cava Gentile) succession to the normal Chron C4n (8.1–7.5 Ma); and v) the maximum range of the Cessaniti land mammal assemblage from Cava Gentile is about 1 Ma, bracketed between 8.1 and 7.2 Ma
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
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
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