1,720,987 research outputs found
Variazioni di portata del Po, eutrofizzazione e comunità macrobentonica in una stazione al largo di Porto Garibaldi (Emilia Romagna, nord Adriatico): dieci anni di studio
No full textPolicheti criptogenici nei mari italiani: caso di Aricidea fragilis (Annelida: Paraonidae)
No full textLo studio e monitoraggio delle specie alloctone in ambiente marino è un elemento di primaria importanza per lo sviluppo di politiche ambientali. Tuttavia, soprattutto con gli invertebrati, non è sempre semplice capire se una specie sia realmente alloctona, o non rappresenti piuttosto un’entità nativa la cui presenza è stata sottostimata. In questo studio si è scelto di studiare la diffusione in Mediterraneo di Aricidea fragilis Webster, 1879, una specie tipica dell’Atlantico occidentale, di cui sono note alcune segnalazioni storiche (Strelzov, 1973; Laubier&Ramos, 1974), ma che negli ultimi anni è stata oggetto di un’ampia espansione demografica principalmente nel Mar Adriatico. Sulla base di dati storici e di dati inediti, con considerazioni sull’ecologia della specie, si tenta di discutere se A. fragilis debba essere considerata alloctona o nativa nei mari italiani. Si tratta, in questo caso, della prima possibile introduzione di un polichete della famiglia Paraonidae
First record of Anadara transversa (Say, 1822) (Bivalvia: Arcidae) in Sardinian waters (NW Tyrrhenian Sea)
No full text
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
Aricidea fragilis (Annelida: Paraonidae) in the Mediterranean Sea: overlooked native or alien species?
No full textThe paraonid polychaete Aricidea fragilis Webster, 1879, a typically west-Atlantic species, is reported from the
Mediterranean Sea on the basis of several individuals, from the Adriatic and Tyrrhenian Sea. Its differences with the
other Mediterranean Paraonidae, and in particular with the morphologically close Aricidea suecica meridionalis Laubier &
Ramos, 1974, are briefly discussed. The possible status of A. fragilis as an alien species in European waters is analysed. The
scarcity of historical records, the relatively restricted distribution, and the population dynamics observed in European waters
strongly support the hypothesis of an introduction, despite the wide temporal interval between the first record of the species
in the 1930s and the currently ongoing range expansion and population explosion. Here we precautionarily suggest
considering A. fragilis a cryptogenic species
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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