1,720,961 research outputs found
Aspetti biologici di Eledone cirrhosa (Cephalopoda Octopoda) nei mari circostanti la Sardegna
No full textData on the biology of Eledone cirrhosa (Cephalopoda Octopoda), collected in the Sardinian Sea during 9 trawl surveys carried out from 1997 to 2001, are presented. In relation to the sexual maturity, reached in spring-summer as in the rest of the Mediterranean basin, we found that when eggs were at their maximum size and lost the reticular system Eledone specimens were far from the fishing areas. Furthermore, even if the most part of individuals spawns at summer at the age of two years, we found a variable percentage of individuals that did not fully develop their gonads until the next year, forming a third group of bigger-sized 3 years old specimens. This finding is in accordance to and supported by the growth curves for the Eledone of large size that attribute to them an age of 3 years instead of two as for the mean adult population which spawn and dead at the age of 22 months
Valutazioni sull’accrescimento di Palinurus elephas (Fabr., 1877) con metodi diretti nei mari sardi
No full textIndagine sulla selettività delle reti da posta in un’area della Sardegna occidentale
No full textFishing experiments have been carried out in western-central Sardinia area by gill nets with a mesh size of 8, 10 and 12. Statistical analysis show that the 12 net gives higher yields in weight in comparison with the 8 and 10 nets, though the caught specimens are more numerous and of smaller size. All the three mesh size nets are selective towards the most important species examined, except for the Diplodus genus. However, a more accurate analysis bring us to conclude that the 12 net is inadvisable, at least for commercial species such as Mullus surmuletus
VALUTAZIONI SULL'ACCRESCIMENTO DI PALINURUS ELEPHAS (FABR., 1877) TRAMIRE MARCATURA E RICATTURA NEI MARI SARDI
No full textAbout 3500 Palinurus elephas (Crustacea, Decapoda) specimens were tagged and released between 1997 and 2001 in an area of centre-western Sardinia where fishing is prohibited (depth range 50-100 m). The size of 116 lobsters, recovered in successive times, were recorded and analysed with two different procedures (Fabens; Gulland and Holt). The Von bertalanffy growth parameters were estimated for each sex and compared by computing the growth performance index (Φ’). Males showed a higher asymptotic carapace length than females (167 vs 120 mm), but a similar Φ’ (3.6 vs 3.5)
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
- …
