1,721,013 research outputs found
Synchronized changes in shallow water carbonate production during the Carnian Pluvial Episode (Late Triassic) throughout Tethys
No full textQuantitative petrologic analysis on carbonates was carried out on stratigraphic sections encompassing the Carnian Pluvial Episode from northwestern Sichuan Basin, South China and eastern Southern Alps. The Carnian Pluvial Episode, or CPE, is a period of climate change that occurred between the early Carnian and the beginning of the late Carnian (Late Triassic) and coincides with multiple, sharp negative excursions of δ13C record that are thought to be evidence of perturbations of the global carbon cycle. During the CPE, relevant environmental modifications and biological turnovers occurred in the marine realm. In particular, microbial carbonate platforms, that were dominant in northwestern Sichuan Basin and throughout Tethys, underwent widespread demise and the microbial component in shelf carbonate sediments sharply decreased and was replaced by ooid- and skeletal grains. Our results show a Tethys-wide coincidence between this change in the carbonate factory. Most notably, both in eastern and western Tethys microbial carbonate production recovered in the late Tuvalian, and the timing of recovery was not influenced by differences of basin evolution and geodynamic setting that characterize such distant domains
Terrestrial laser scanner imaging reveals astronomical forcing in the Early Cretaceous of the Tethys realm
No full textWe present the first application of the terrestrial laser scanner (TLS) to cyclostratigraphy and demonstrate the capability of this remote sensing technology in rapid retrieval of high resolution cyclostratigraphic data from typical hemipelagic successions exposed in outcrops with limited accessibility. TLS infrared imaging is capable of recording, up to a distance of 50. m, a laser intensity value which is inversely proportional to the abundance of clay minerals in limestones and marls. The following characteristics make TLS a very useful tool: 1) fast data collection; 2) high-resolution and high accuracy; and 3) TLS is an active, sensor-based acquisition process that is independent from environmental conditions as illumination. We demonstrate this new methodology with a study of a section in the Early Cretaceous (Albian) Marne a Fucoidi formation exposed in the Vispi Quarry near Gubbio (central Italy). The same stratigraphic interval has been studied in detail in a core drilled at a few kilometers away (the Piobbico core). We compare TLS results with those obtained previously from the Piobbico core, and propose a correlation between the two sections. Results indicate clear cyclicity in the TLS data, that correlates to the Piobbico data. This is the first report of correlation at the eccentricity scale in pre-Cenozoic stratigraphy. Statistical time series analysis confirms the presence of astronomical parameters with a predominance of eccentricity cycles, in agreement with the Piobbico core. The future application of TLS in cyclostratigraphy will rapidly enrich the collection of series with Milankovitch cycles needed to build a Mesozoic astrochronological time scale
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
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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