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S. Elmi et C. Babin - Histoire de la terre, coll. «Cursus », 1994
No full textS. Elmi et C. Babin - Histoire de la terre, coll. «Cursus », 1994. In: L'information géographique, volume 60, n°3, 1996. p. 132
S. Elmi et C. Babin - Histoire de la terre, coll. «Cursus », 1994
No full textS. Elmi et C. Babin - Histoire de la terre, coll. «Cursus », 1994. In: L'information géographique, volume 60, n°3, 1996. p. 132
Tolerance develops to sympathetic effects of khat in humans
No full textKhat chewing has been found to induce, like amphetamines, psychostimulation and increase in sympathetic tone. The possibility that tolerance develops to these effects has been studied by comparing the influence of the chewing of a standard dose of khat on some physiological parameters in chronic consumers and naive subjects. Systolic blood pressure appears to rise in both groups, but the increase in diastolic pressure was more marked in naive subjects and inversely related to the reduction of pulse rate. The increases of respiratory rate and body temperature were also higher in naive subjects. In both groups, all these effects disappeared after 18 h. These results are consistent with an amphetamine-like mechanism of action and suggest that tolerance develops to the sympathetic effects of khat
Etude paléontologique et dynamique d'un intervalle condensé à gastropodes dans les calcaires à grands bivalves du Pliensbachien (Ouarsenis, Algérie)
No full textThe large bivalve limestones of the Grand Pic de l'Ouarsenis have yielded a gastropod fauna attributed to the Middle Carixian (Lower Pliensbachian) by Metaderoceras sp. and to the Cl biozone of the benthic foraminifer chart. Its palaeontological study allows to recognize and to describe eight species belonging to seven different superfamilies, despite their poor state of preservation. Some taxa are known on both sides of the Tethys (northwestern and maghrebian margins). The environmental setting of the Ouarsenis fauna is mainly controlled by an insular palaeotopography and by autocyciclic processes (tectonic and hydrodynamism). The deposit of the gastropod fauna has occurred during the transgressive phase of a 3rd order sequence (condensed interval sensu Vail et al., 1991). These events, occurring during the Late Carixian times, are well documented along the south-tellian border. The eustatic deepening is complicated by the local tilted-blocks tectonics. In these conditions, the gastropods level has been deposited in a weak sedimentation rate setting and its environment is located to the upper part of the photic zone and subjected to low hydrodynamic conditions. The marine waters were warm, calm, with a normal salinity
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
Characterization of the surface properties of polycrystalline WO3
No full textTungsten trioxide was precipitated from an ammonium paratungstate aqueous solution at acid pH. The precipitated material consists of a mixture of hexagonal and pseudocubic WO3. After calcination at about 700 K, it transforms into monophasic pseudocubic WO3 (15m2 g−2). FTIR investigation of adsorbed water, ammonia, pyridine, pivalonitrile and CO2 indicates an acid nature of the surface. Two types of strong Lewis acid sites, as well as Brönsted acid sites, have been detected. Models are proposed for the surface sites of WO3, and the catalytic activity of WO3-containing catalysts is briefly discussed in relation to their surface chemistry
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
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