186,282 research outputs found
Boudouresque, C.F., Jeudy de grissac, A. et Olivier, J. (Editors). — First International Workshop on Posidonia oceanica Beds. Porquerolles, France, 12-15 October 1983 Published by G. I. S. Posidonie, Marseille, France
No full textGrillas Patrick. Boudouresque, C.F., Jeudy de grissac, A. et Olivier, J. (Editors). — First International Workshop on Posidonia oceanica Beds. Porquerolles, France, 12-15 October 1983 Published by G. I. S. Posidonie, Marseille, France. In: Revue d'Écologie (La Terre et La Vie), tome 43, n°3, 1988. p. 325
Effect of inter-annual meteorological fluctuations and wild boar disturbance on the vegetation of Mediterranean temporary ponds
No full textQuestions: Which are the effects of inter-annual meteorological fluctuations on plant species richness and vegetation dynamics in Mediterranean temporary ponds, shallow wetlands characterized by alternating phases of drought and flooding? Which are the effects of wild boar disturbance? How do the responses of specialist or non-specialist species of the habitat differ?. Location: NW Sardinia Island (Italy). Methods: We assessed plant cover during six years within one 60 cm × 60 cm quadrat in each of five areas. To measure the effect of inter-annual meteorological fluctuations on vegetation, we used two indices: the evapotranspiration and the synthetic agrometeorological indicator. To quantify the effect of disturbance by boars, we compared two treatments: disturbed and non-disturbed (located outside and inside 1.5 m × 1.5 m exclosures respectively). As a whole, we monitored 60 plots (6 years × 2 treatments × 5 replications). We analyzed data using ANOVA, PERMANOVA and BIO-ENV. Results: Plant species richness and composition showed significant differences between years and treatments. Species composition was correlated with the evapotranspiration before the vegetative peak during the last period and with the agrometeorological indicator during the whole vegetative period. Specialist species showed much weaker growth, quantified as cover, in the drier years. Starting from the third survey year, plant richness and cover of specialist species were significantly higher in disturbed than in not-disturbed plots. The extent of bare soil generally was not affected by the treatment. Conclusions: Meteorological fluctuations affect plant species composition and vegetation dynamics in Mediterranean temporary ponds. The sensitivity of specialist species could make them particularly vulnerable to climate change. Nevertheless, they are resilient to unpredictable disturbances such as burrowing by wild boar. However, our results concerning the positive impact of wild boar disturbance on the vegetation cannot be generalized. Elsewhere, the lack of hunting activity could also be a problem for these habitats
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Grislas: un algoritmo genético paralelo que combina los modelos de grillas e islas para encontrar soluciones óptimas cercanas al problema del agente viajero
No full textEste trabajo implementa un modelo de Algoritmo Genético Par alelo llamado modelo de Gris-Las, mejorado con optimización local 2opt. Este modelo está enfocado a encontrar soluciones óptimas cercanas al problema del Agente Viajero sobre un ambiente de cómputo distribuido. Gris-Las se basa esencialmente en dos modelos comunes de Algoritmos Genéticos Paralelos, el modelo de Grillas (modelo celular ) y el modelo de Islas. El algoritmo heurístico de optimización local 2opt también es utilizado para reducir el dominio de búsqueda en el problema
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
Conséquences des changements hydrologiques sur le fonctionnement biologique d’une lagune
No full textGrillas Patrick, Charpentier Anne, Chauvelon Philippe, Crivelli Alain Jean, Sandoz Alain, Lescuyer F., Coulet Eric. Conséquences des changements hydrologiques sur le fonctionnement biologique d’une lagune . In: Revue d'Écologie (La Terre et La Vie), tome 59, n°1-2, 2004. p. 367
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