177,015 research outputs found
Crinoid columnal associations and sequence stratigraphy architecture: the Le Faou Formation, Lower Devonian of the Massif armoricain (France)
No full textCrinoid columnals are major rnacrobenthic components of the Lower Devonian faunas of the Massif armoricain particularly in the Seillou section. Three crinoid columnal associations have been delineated based on R and Q-mode cluster analysis. Distribution of these associations is correlated to the sequence stratigraphic architecture, showing the close relationships between crinoid columnal association dynamics and relative sea-level variations. Comparing the distribution of benthic associations, we note a lesser diversity in crinoid columnal associations than in brachiopod ones. Crinoids (high-level Suspension feeders) seem to occupy broader specialised niches than brachiopods (reclining and low-level suspension feeders) and are characterised by a different ecological space utilisation
Paleoecologie des associations marines paleozoïques, rôle des variations du niveau relatif de la mer
No full textCommunautés benthiques à brachiopodes et variations eustatiques: exemple de la Formation du Faou (Dévonien, Massif armoricain, France)
No full textA detailed study of the Seillou section (Le Faou Fm., Armorican Massif) on the ground of sequence stratigraphy and palaeontological content results in the definition of the relationships between the brachiopod benthic assemblages and the sea-level fluctuations. ((C) Academie des sciences / Elsevier, Paris.
Relations entre les variations des assemblages benthiques emsiens et l’eustatisme dans la coupe de Seillou (Massif armoricain, France)
No full textPalaeoecological study and sequence stratigraphy of the Emsian part of the Seillou section (Le Faou formation, Armorican massif) allows the identification of benthic and pelagic associations, and shows the correlation between the distribution of associations and the sea level variations. A major change in sedimentation and faunas could represent the signature of the Basal Zlichov Event in the Armorican massif. (C) 2001 Academie des sciences / Editions scientifiques et medicales Elsevier SAS
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
Benthic assemblages, palynomorphs, and medium to high frequency cycles near the Pragian-Emsian boundary in the Armorican Massif (Western France)
No full text"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Genesis and significance of shellbeds in terrigenous platform deposits: an example from the Ordovician of Sardinia
No full textFormation et signification paléo-environnementale des concentrations coquillières: exemples de l'Ordovicien de Sardaigne et du Dévonien du Massif armoricain
No full textFormation and palaeoenvironmental significance of shellbeds: examples from the Ordovician of Sardinia and the
Devonian of Armorican Massif. The study of shellbeds in the terrigenous platform deposits of the Upper Ordovician of
Sardinia and Lower Devonian of the Armorican Massif, considering the taphonomic signatures and their repartition at the scale
of a genetic sequence, allows us to distinguish two types of shellbeds (types A and B) and to suggest a genetic model for their
origin. Shellbeds formation is related to autocyclic and allocyclic constraints. Type A shellbeds are associated with high or
moderate supply episodes during sea level falls, while type B shellbeds are related to low supply episodes during sea-level rises
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
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