1,720,969 research outputs found
Eléments radiochronologiques et palynologiques sur les alluvions du lit majeur de la Loire (Val d'Avaray, Loir-et-Cher, France) / Radiocarbon dating and palynology of alluvial deposits in the Loire flood plain (Val d'Avaray, Loir-et-Cher, France).
No full textChronology and stratigraphy of major bed alluvial deposits of middle Loire River had been performed studying four cored boreholes realised in clay and peat infilling of oxbows.
Diachronism of oxbows infilling permits the reconstruction of a composite sequence covering Late glacial and Holocene. Numerous radiocarbon dating and high resolution palynological studies offer possibility of vegetation reconstruction over these periods. Impact of anthropogenic activities on watershed-scale erosion are suspected during both Bronze and Gallo roman ages (around 3,300 and 1,990 B.P.).L'étude de quatre sondages carottés réalisés dans le remplissage argilo-tourbeux de bras mort en Loire moyenne a permis de caractériser les cadres chronologique et stratigraphique des alluvions du lit majeur de ce secteur. Les nombreuses datations radiochronologiques associés aux études palynologiques ont permis de retracer l'évolution du peuplement végétal du Tardiglaciaire au Subatlantique. Des indices d'impact de l'activité anthropique locale et à l'échelle du bassin versant ont été identifiés.Garcin Manuel, Farjanel Geneviève, Giot Denis. Eléments radiochronologiques et palynologiques sur les alluvions du lit majeur de la Loire (Val d'Avaray, Loir-et-Cher, France) / Radiocarbon dating and palynology of alluvial deposits in the Loire flood plain (Val d'Avaray, Loir-et-Cher, France).. In: Quaternaire, vol. 12, n°1-2, 2001. Paléoenvironnements holocènes et géoarchéologie. pp. 69-88
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
Le gîte de Bois Madame (Hérault) : une minéralisation Pb-Zn de milieu confiné en plate-forme carbonatée. The Bois Madame (Hérault, France) ore deposit : a Pb-Zn mineralization in a confined environment on a carbonate platform
No full textConcentrations of iron, zinc and lead sulphides occur in the lower part of the formation known as Bois Madame, of late Upper Kimmeridgian age.
Paleostructural and paleogeographic reconstructions suggest that these concentrations were deposited in a confined area, within a carbonate platform, that was the site for entrapment of calcaro-sapropelic deposits already enriched in metals. The formation was affected by stratiform dolomitization of a distinctive, uniformly fine-grained euhedral textural facies that resulted in the creation of an impermeable barrier at a relatively early diagenetic stage. The main consequences of this were diagenetic maturation in a closed system and protection against external agencies. Another, regional and crosscutting dolomitization originating from the underlying Portlandian reefal dolostones did not affect the Bois Madame formation.
Within their dolomitic envelope, the initial disseminated sulphides are selectively concentrated in the sapropelic horizons. Organic matter play a determining role at several stages in the birth and development of highgrade ore body. Very early during diagenesis it was responsible for the development of reducing conditions that affected the behaviour of the metals : fixation followed by precipitation by bacterial bioreduction of marine sulfates. Also, being distributed in layers, the organic material acted as drains in the relatively impermeable carbonate rocks, thereby allowing the later development of reconcentrations during compaction-dissolution processes.
The orebody is such that, with the syndepositional appareance of the first sulphides followed by an early closure to extend influences, it can be proposed as a model of stratiform syndiagenetic, metal concentration.Les concentrations sulfurées à fer, zinc et plomb sont encaissées dans la partie inférieure de la formation dite de Bois Madame, d'âge Kimméridgien supérieur.
Les reconstitutions paléostructurales et paléogéographiques conduisent à envisager la genèse de ces concentrations dans un site de confinement au sein d'une plate-forme carbonatée. Ce site opère comme piège de dépôts calcaro-sapropéliques précocement enrichis en métaux. Une dolomitisation stratiforme à faciès particulier, automorphe, homométrique fin, affecte la formation et engendre une barrière de perméabilité à un stade relativement précoce de la diagenèse. En conséquence la maturation diagénétique va se développer en système fermé, et isoler la formation à l'égard de fluides extérieurs. Ainsi, une seconde dolomitisation, d'extension régionale, recoupe la série ; elle est issue des formations récifales portlandiennes sus-jacentes ; elle est sans action sur la formation de Bois Madame.
Au sein de leur enveloppe de dolomie, les sulfures métalliques disséminés se concentrent de façon très sélective sur les horizons sapropéliques. La matière organique joue un rôle déterminant à plusieurs reprises dans la naissance et l'évolution du gîte. Au cours de la diagenèse très précoce, elle est responsable du développement de conditions réductrices qui provoquent la fixation puis la précipitation des métaux par réduction bactérienne des sulfates marins. En second lieu, étant répartie en strates, elle joue un rôle de drain dans les dolomies peu perméables et permet le développement de reconcentrations sulfurées plus tardives par compaction-dissolution.
Tel qu'il se présente avec apparition des premiers sulfures dès l'étape sédimentaire puis une fermeture précoce aux apports extérieurs, ce gîte peut être proposé comme un modèle de concentration métallique syndiagénétique.Aubague Maurice, Giot Denis, Sureau Jean-François. Le gîte de Bois Madame (Hérault) : une minéralisation Pb-Zn de milieu confiné en plate-forme carbonatée. The Bois Madame (Hérault, France) ore deposit : a Pb-Zn mineralization in a confined environment on a carbonate platform. In: Sciences Géologiques. Bulletin, tome 39, n°3, 1986. Concentrations métalliques et milieux confinés. pp. 251-262
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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