1,720,965 research outputs found
Geomorphic and neotectonic evolution of the Ecuadorian Andes
No full textIn Early Miocene times the Cordillera did not exist and the Pacific Ocean reached the Oriente. In the Middle Miocene, the uplift of an elongated swell, consisting of Palaeozoic and older rocks, created the Eastern Cordillera. Decollements were activated diverging away from the Eastern Cordillera. In the eastern trench, located approximately in correspondence with the present day Interandean Depression, many thousands of meters of sediments were deposited. A planation surface was created at the end of Lower Pliocene from the Costa to the Oriente graded to sea level. Later, ignimbric flows covered much of the planation surface. Uplift brought the planation surface to 3500-4000 m. The Interandean Depression, bounded by normal faults, was created during the Upper Pliocene, and large strato-volcanoes erupted at this time. The volcanic activity contributed to the filling of an accumulation plateau preserved today in many parts of the Interandean Depression. The creation of the Interandean Depression is the result of lateral spreading activated as a consequence of uplift of the Cordillera. In the Middle and Late Pleistocene the Cordillera and the Accumulation plateau were mostly affected by downcutting with minor episodes of accumulation during the cold phases. (C) 2000 Elsevier Science B.V. All rights reserved
The significance of high planation surfaces in the Andes of Ecuador
No full textA traverse of Ecuador crosses five planated units including two main horsts which constitute the Andean Cordillera. A single surface once extended across all units, and its formation was completed by Early Pliocene times. Vertical uplift occurred mainly in the Plio-Pleistocene. Most rock structures in the Andes result from pre-planation tectonics and have no connection with mountain building. Post-planation vertical uplift created the mountains, and uplift led to gravitational spreading. The causes of stillstand and uplift are debatable but subduction and compression fail to account for the nature, the symmetry and the timing of events in the Ecuadorian Andes
Neotectonic mountain uplift: some further instances
No full textBriefly, the concept of the Neotectonic Period is that
most of the world’s mountains have been uplifted in
the past few million years, after a period of planation. If
folding is present it usually preceded the planation. The age of mountains is thus the age of uplift, not the age of the last folding, if any. Neotectonic uplift affects mountains on active continental margins, passive margins, continental interiors and island arcs. Examples of mountains from all around the world are included in these references, and updated tables have been published elsewhere and present article records several further examples
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
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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