1,720,962 research outputs found
A fluvial-dominated, lacustrine, sandy Gilbert-type delta in the Pleistocene Dandiero Basin (Eritrea): sedimentary processes and depositional architecture
No full textDetecting large-scale fluvial bars from the sedimentary record: a lesson from the Pleistocene Dandiero Basin (Eritrea)
No full textPalaeoenvironments of the Buia Homo site: High-resolution facies analysis and non-marine sequence stratigraphy in the Alat formation (Pleistocene Dandiero Basin, Danakil depression, Eritrea).
No full textThe Early to Middle Pleistocene Dandiero rift basin is located nearby to the Buia village, 110 km south of Massawa (Eritrea), and is filled by about 1,000 m of continental deposits bearing 1 My erectus-like human remains. The basin fill consists of six formations (from bottom up): Bukra sand and gravels (fluvial), Alat formation (fluvio-lacustrine), Wara sand and gravel (fluvial), Goreya formation (lacustrine), Aro sand (fluvio-deltaic) and Addai fanglomerate (alluvial fan). This paper is focused on the Homo-bearing deposits of the Alat formation and deals with facies analyses and palaeoenvironmental reconstruction. The Alat formation records several episodes of changing accommodation space, with repeated shifts from fluvial to lacustrine conditions. The first episode points to rapid lake formation followed by a progressive shallowing. The second episode records fluvial aggradation above a sequence boundary, followed by the development and progressive infill of a second lake. The third episode points to a rapid lake formation followed by deposition of deltaic and fluvial sediments. The last episode is characterised by fluvial deposition under low accommodation conditions. The development of the lacustrine environments was probably controlled by tectonics, in accordance with its formation during regionally dry climatic conditions, although minor shifts toward wetter conditions cannot be excluded. Human remains occur in the upper Alat formation., where the transition from a deltaic to alluvial setting is characterized by high frequency, potentially millennial-scale, lake-level oscillations. The palaeoanthropological record in the Buia area seems to be correlated with water availability (lacustrine coastal plains and floodplains) in relatively open and grassy environment (grassland- and savannah-dominated). The increase in fluvial discharge that occurred at the top of the Alat formation led to erosion and winnowing of the underlying fossil-bearing, fluvio-deltaic deposits. A large number of bones and artefacts were consequently accumulated at the base of channel fills, which represent a preferential horizon for fossils searching
Stratigraphic context and taxonomic assessment of the large cercopithecoid (Primates, Mammalia) from the late Early Pleistocene palaeoanthropological site of Buia (Eritrea).
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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
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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