1,720,979 research outputs found
A new vision for ecological network: integrating hierarchical landscape classification and multi-taxon data to support local planning decisions
No full textGeographical and ecological differentiation in Italian mesophilous pastures referred to the alliance Cynosurion cristati Tx. 1947
No full textThe alliance Cynosurion cristati has been found by various authors across the European continent. However, the fact that its diagnosis is based on species that are found in a wide range of geographical and ecological conditions and on the absence of grazing-sensitive species has rendered the characterization of this alliance somewhat complicated.
The aims of this paper were: i) to investigate differences in the composition of some European mesophilous pastures, with particular focus on Italy; ii) to assess the main factors underlying these changes; iii) to evaluate the need for a new classification for such communities in the Italian peninsula. We used previously published data from several other European countries and both published and unpublished data from Italy. A synoptic table of data from different parts of Europe was analysed by means of hierarchical clustering. We used Multi- Response Permutational Procedure and phi coefficient to test differences between Cynosurion clusters and identify their diagnostic species. We performed Non-metric Multi-Dimensional Scaling on a table of 111 Ital- ian relevés. Kendall’s correlation coefficient was calculated by relating the relevé scores in the ordination with the geographical, environmental variables, and with the Ellenberg indices relative to soil conditions. The first axis scores were also used as the dependent variable in a regression tree. Important compositional differ- ences were found within the Cynosurion cluster, with significant differences emerging between the Apennine pastures in central and southern Italy and those in northern and central Italy. The first axis ordination was strongly related to the latitudinal/thermal gradient. Indeed, latitude and temperature were the most important variables in the regression tree. Our results highlight marked compositional variation in Cynosurion grass- lands. This variation, which is related in the Italian peninsula to bioclimatic and biogeographical factors, led us to propose a rearrangement of the existing classification of the alliance for this part of Europe
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
Un aggiornamento della flora del Cilento e della Campania
No full textUpdate to the Flora of Cilento and Campania region (Southern Italy) - We present the results of floristic researches carried out from 1984 to 2011 in the area of Cilento (Campania region, southern Italy). We listed, from original data, 71 taxa: 9 result new records for the Campania region; 38 are new to the flora of Cilento; furthermore we report the findings of 18 species requiring confirmation and some detail regarding infraspecific taxa. We argue that, considering the actual state of knowledge, the flora of Cilento account of 2070 taxa and that the incidence of exotic species (as well as invasive) in the recent records, is high. Finally, we pointed out that the flora of wetlands and ponds, despite some interesting new findings, is heavily threatened by habitat loss and fragmentation resulting in small populations, undergoing to local risk of extinction
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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