1,720,973 research outputs found
Floristic changes along the topographical gradient in montane grasslands in Monti Picentini (Campania, SW Italy)
No full textDeciduous Oak Forests Database of the Italian Peninsula
No full textThe existence of large databases is fundamental to improve ecological and phytogeographical information to build a ‘natural’ syntaxonomic scheme. In different parts of Europe, deciduous forests have already been well studied and their phytosociological meaning interpreted at regional level, nevertheless a broader scale approach is often missing. To define the thermophilic and mesophilic oak deciduous forests of Southern Europe there are several syntaxonomical proposals at higher ranks, that show differences in their ecological significance. Several Authors use the Querco-Fagetea class by which the differences between oak, mixed and beech forests are expressed at the level of order and alliance. Despite the clear link between the Italian and Balkan Peninsula, the Apennines maintain strong links with the forest vegetation of Central Europe, interpretable only within the Querco- Fagetea class. In Italy phytosociological studies focused on deciduous oak forests have a relative recent tradition compared with other countries. In particular there are a great number of local contributions, while there are only few contributions that tackle syntaxonomical issues at a broader, peninsular level. For these reasons the aim of this database is to collect relevés of oak forests belonging to the Quercetalia pubescenti-petraeae and Fagetalia sylvaticae orders to perform numerical analyses and classification. Thermophilous and thermo-mesophilous oak forests are dominated by various species such as Quercus cerris, Q. pubescens, Q. frainetto, Carpinus betulus, Carpinus orientalis, Ostrya carpinifolia, Fraxinus ornus and Acer opalus obtusatum. The present project is based on selected published (and unpublished) relevés recorded according to the Braun-Blanquet approach and stored in a TURBOVEG database. At present 1,600 relevés of oak forests vegetation surveyed in Peninsular Italy are stored in the Deciduous Oak Forests Database of the Italian Peninsula (GIVD ID EU-IT-006). The future goals are to determine whether the variation in species composition follows a geographical pattern, to test the real ecological characteristics of the associations recognised by phytosociological studies and to identify which diagnostic species can be used for different types
Phytoclimatic characterization of Quercus frainetto Ten. stands in peninsular Italy
No full textThe floristic differentiation of the deciduous Quercus frainetto forests along the climatic gradients of Apennine Italy has been studied. The ecological amplitude of this oak, and the bioclimatological relationships here assessed, suggest potentiality for the growth of Q. frainetto-rich communities as broad zonal vegetation belt, ranging from NW to SE along the W side of peninsular Italy. Strong floristical and ecological similarities to the balcanic stands are described. The status of real vegetation belt for the Italian Quercion frainetto s.l. is here emphasized
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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