1,720,961 research outputs found
Una revisione critica della check-list e della bibliografia degli Odonati della Sicilia
Full text linkFirst records of the Brahminy blindsnake, Indotyphlops braminus (Daudin, 1803), in Italy (Squamata: Typhlopidae)
Full text linkPatterns of genetic and phenotypic diversity of the Mediterranean banded centipede Scolopendra cingulata Latreille, 1829 (Chilopoda: Scolopendromorpha) in Sicily and adjacent areas
No full textThe genus Scolopendra is a taxonomically complex group, with species displaying intricate evolutionary radiation across Mediterranean islands. The present work aims to explore the diversity patterns of the Mediterranean banded centipede S. cingulata across Sicily, some surrounding islands, and Southern Calabria, investigating its genetic (COI and 28S) and phenotypic variation. Through extensive sampling and the analysis of 92 COI sequences from 82 sampling sites, three distinct structured lineages were identified in the study area: Sicily/Malta (SM), Eastern Peloritani Mountains (EP), and Aspromonte (As). Conversely, 28S sequences did not reveal the same genetic structure observed in the COI, probably due to the occurrence of introgression phenomena. Morphological assessments showed significant variation among clades. Colour pattern analysis revealed distinguishable morphotypes among the three clades. SM juveniles exhibit a unique light morphotype, contrasting with the dark dichromatic morphotype common to As and EP juveniles. These findings seem to suggest multiple colonisation events and prolonged isolation periods in Sicily, which shaped the current diversity of S. cingulata on the island. The genetic distinctiveness and apparent parapatric distribution of SM and EP, with limited evidence of admixture, highlight the need for further studies to fully understand the evolutionary history and potential taxonomic implications for this taxon
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
L’ultima spiaggia. Il declino degli ecosistemi dunali della Sicilia negli ultimi 50 anni
No full textQuesto contributo mira non solo a denunciare l’estremo degrado di buona parte degli ecosistemi dunali della Sicilia, ma anche a suggerire strategie efficaci per una corretta salvaguardia e gestione sostenibile di ciò che ne rimane
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