1,721,002 research outputs found
Sedimentary processes and deposits associated with a coastal headland: Portland Bill, southern UK
No full textThe present study investigates the sedimentary processes and deposits, associated with a coastal headland. The case study considered here is the continental shelf around Portland Bill (southern UK). A range of different scientific approaches was undertaken, in order to develop and expand upon the scientific understanding of such processes and deposits: (a) numerical modelling (including tidally-induced flow, sand transport and wave refraction); (b) in situ hydrodynamic measurements; and (c) geophysical surveys (side-scan sonar and using an high-resolution seismic profiler) and sediment sampling. The presence of a sequence of sedimentary deposits, associated with a complex suite of bedforms and sedimentary facies, was observed. This sequence of deposits, described as headland-shelf deposits (HSD), have a reasonably symmetrical sigmoidal plan-view distribution, on both sites of the headland; they are described, sequentially, towards the headland, as: sand shoals, or "sand streams" (the Adamant and West Shoals); sandy/gravel flats, representing sand bypass zones (the East and West Flats); and sandbanks, associated with zones of sand convergence (Shambles and Portland Banks). The HSD are isolated laterally, but are connected longitudinally. Both shoals and banks have an asymmetric cross-section steeper towards the coast, being the main depocentres over the area. The distribution of such facies and deposits is controlled by instantaneous gradients in bed shear stress and sediment transport rates; these are related to the transient development of headland-eddies and the associated bedload transport. Sediment transport, associated with a coastal headland, is defined by the occurrence of two conceptually-distinct zones: (a) an inner zone, showing sand transport towards the headland, following an increase in gradient in the sand transport rates; and (b) an outer zone, showing sand transport away from the headland, following a decrease in gradient in the transport rates. The boundary between these two zones defines a bedload convergence zone. At the tip of the headland, a scour zone (or zone of maximum erosion) is present.</p
Bryozoan framework composition in the oddly shaped reefs from Abrolhos Bank, Brazil, southwestern Atlantic: taxonomy and ecology
No full textRamalho, Laís V., Taylor, Paul D., Moraes, Fernando Coreixas, Moura, Rodrigo, Amado-Filho, Gilberto M., Bastos, Alex C. (2018): Bryozoan framework composition in the oddly shaped reefs from Abrolhos Bank, Brazil, southwestern Atlantic: taxonomy and ecology. Zootaxa 4483 (1): 155-186, DOI: 10.11646/zootaxa.4483.1.
FIGURE 5. Cribrilaria lateralis Ramalho & Moraes n in Bryozoa from the reefs off the Amazon River mouth: checklist, thirteen new species, and notes on their ecology and distribution
No full textFIGURE 5. Cribrilaria lateralis Ramalho & Moraes n. sp. (Holotype MNRJBRY-1527). A. Colony with fertile and infertile zooids and large triangular avicularia. B. Ovicellate zooid with four spines, infertile autozooids with five spines and a large triangular avicularium. C. Ancestrula with 12 spines, most with apophyses directed inwardly. Scale bars: A, B, 100 µm; C, 50 µm.Published as part of Ramalho, Laís V., Moraes, Fernando C., Salgado, Leonardo T., Bastos, Alex C. & Moura, Rodrigo L., 2021, Bryozoa from the reefs off the Amazon River mouth: checklist, thirteen new species, and notes on their ecology and distribution, pp. 1-45 in Zootaxa 4950 (1) on page 10, DOI: 10.11646/zootaxa.4950.1.1, http://zenodo.org/record/464324
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
FIGURE 9. A–D. Thornelya atlanticoensis Ramalho & Moraes n in Bryozoa from the reefs off the Amazon River mouth: checklist, thirteen new species, and notes on their ecology and distribution
No full textFIGURE 9. A–D. Thornelya atlanticoensis Ramalho & Moraes n. sp. (Holotype MNRJBRY-1452). A. Colony with both ovicellate and non-ovicellate zooids. B. Autozooids showing orifice with spines, and lateral avicularia. C. Unbleached colony showing zooids with long spines. D. Fertile zooid showing lateral avicularia and ovicell bearing a small avicularium. E–G. Therenia dianae Ramalho & Moraes n. sp. (Holotype MNRJBRY-1431). E. Colony edge with several fertile and infertile zooids and large avicularium. F. Detail of zooids showing orifices with a small sinus, and avicularia. G. Detail of an ovicellate zooid. Scale bars: A, E, 500 µm; B, C, 250 µm; D, 100 µm; F, G, 200 µm.Published as part of Ramalho, Laís V., Moraes, Fernando C., Salgado, Leonardo T., Bastos, Alex C. & Moura, Rodrigo L., 2021, Bryozoa from the reefs off the Amazon River mouth: checklist, thirteen new species, and notes on their ecology and distribution, pp. 1-45 in Zootaxa 4950 (1) on page 19, DOI: 10.11646/zootaxa.4950.1.1, http://zenodo.org/record/464324
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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