1,720,966 research outputs found
Ecologie de Leptoconops irritans Noé, 1905 en moyenne Camargue. Localisation et dynamique des biotopes larvaires
No full textRioux Jean-Antoine, Descous Suzanne, Corre Jean-Jacques, Croset Henri, Tour S. Ecologie de Leptoconops irritans Noé, 1905 en moyenne Camargue. Localisation et dynamique des biotopes larvaires . In: La Terre et La Vie, Revue d'Histoire naturelle, tome 22, n°4, 1968. pp. 458-469
Biologie évolutive des populations Ouest-Européennes de Crocidures. I. — Critères d’identification et répartition biogéographique de Crocidura russula (Hermann, 1780) et Crocidura suaveolens (Pallas 1811)
No full textUsing cytocaryologic and electrophoretic techniques, the authors were able to clarify the taxonomic status of a number of populations of three european species of shrews belonging to genus Crocidura.
They propose a set of reliable morphological criteria to allow the identification of Crocidura russula, C. leucodon and C. suaveolens (Figs 1 and 2). The present distribution of C. russula and C. suaveolens in Europe is critically reviewed, and shown on figures 3 and 4. — They also propose a new interpretation of the past history of the group, based on new subfossil material.L’emploi des techniques cytocaryologique et électrophorétique a permis de préciser le statut taxinomique encore controversé de populations des trois Crocidures européennes, de sélectionner des critères d’identification morphologiques sûrs et, sur la base de ces critères, de délimiter l’aire de répartition de Crocidura russula et de Crocidura suaveolens en Europe. Ces nouvelles données permettent de proposer un scénario cohérent de l’histoire des peuplements de Crocidures.Poitevin F., Catalan Josette, Fons Roger, Croset Henri. Biologie évolutive des populations Ouest-Européennes de Crocidures. I. — Critères d’identification et répartition biogéographique de Crocidura russula (Hermann, 1780) et Crocidura suaveolens (Pallas 1811). In: Revue d'Écologie (La Terre et La Vie), tome 41, n°4, 1986. pp. 299-314
Biologie évolutive des populations Ouest-Européennes de Crocidures (Mammalia, Insectivora). II. — Ecologie comparée de Crocidura russula Hermann, 1780 et de Crocidura suaveolens Pallas, 1811 dans le midi de la France et en Corse : rôle probable de la compétition dans le partage des milieux
No full textThe ecological requirements of two species of shrews, the Greater Whitetoothed Shrew (Crocidura russula) and the Lesser White-toothed Shrew (Crocidura suaveolens) were compared in Southern France and Corsica.
Both species are shown to differ in their ecophysiology. However, their fundamental niches are not fully realized when the two species coexist, which suggests some kind of competition between the two. This view is supported by the fact that the two shrew species are very seldom met together at a same traping site on the mainland, and by the larger size of C. suaveolens in Corsica, where C. russula does not occur.L’écologie comparée des populations de Crocidura russula et de Crocidura suaveolens dans le midi de la France et en Corse, a permis de mettre en évidence des besoins éco-physiologiques différents pour ces deux espèces. Toutefois, la comparaison de populations continentales et insulaires a montré que la niche potentielle de chacune d’entre elles était également limitée par la présence de l’autre. On en conclut qu’il existe une compétition interspécifique active. Cette hypothèse est renforcée par la quasi exclusion spatiale des deux espèces à l’échelle de la station et l’augmentation importante de la taille de l’espèce la plus petite (Crocidura suaveolens) en condition insulaire où cette compétition n’existe pas.Poitevin F., Catalan Josette, Fons Roger, Croset Henri. Biologie évolutive des populations Ouest-Européennes de Crocidures (Mammalia, Insectivora). II. — Ecologie comparée de Crocidura russula Hermann, 1780 et de Crocidura suaveolens Pallas, 1811 dans le midi de la France et en Corse : rôle probable de la compétition dans le partage des milieux. In: Revue d'Écologie (La Terre et La Vie), tome 42, n°1, 1987. pp. 39-58
Premières données sur l’écologie des populations naturelles de souris, Mus spretus Lataste et Mus musculus domesticus Rutty dans le Midi de la France
No full textTwo species of mice Mus spretus and Mus musculus domesticus, live in Southern France. The identification criteria are discussed, together with the geographical distribution and ecological requirements of the two species. Because of its high water requirements Mus musculus domesticus cannot live permanently in arid habitats, such as the «garrigues», a more or less open community of small shrubs of Quercus coccifera. On the contrary, the absence of Mus spretus from more humid habitats cannot be attributed to by any environmental factor in particular. Preliminary laboratory experiments and observations in open-air enclosures suggest that the very presence of Mus musculus domesticus in its optimal habitat can inhibit the reproduction of Mus spretus.Après avoir rappelé les critères d’identification des deux Souris du Midi de la France, Mus spretus et Mus musculus domesticus, les auteurs précisent la répartition biogéographique et écologique des deux espèces. Leurs observations montrent que Mus musculus domesticus est limitée vers les biotopes arides (garrigues à Chêne kermès), par ses exigences hydriques. A l’inverse, la limite de Mus spretus vers les biotopes humides ne peut être expliquée par des facteurs mésologiques. Des expériences préliminaires, au laboratoire et en enclos extérieurs, semblent indiquer une limitation de la reproduction de Mus spretus par Mus musculus domesticus dès que les conditions mésologiques sont favorables à cette dernière.Orsini Ph., Cassaing Jacques, Duplantier Jean-Marc, Croset Henri. Premières données sur l’écologie des populations naturelles de souris, Mus spretus Lataste et Mus musculus domesticus Rutty dans le Midi de la France. In: Revue d'Écologie (La Terre et La Vie), tome 36, n°3, 1982. pp. 321-336
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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