1,721,006 research outputs found
Geographical and bathymetrical distribution of Aristaeomorpha foliacea and Aristeus antennatus (DECAPODA, ARISTEIDAE) in the Greek Ionian Sea
No full textEssential habitats for unexploited deep-water resources in the Ionian Sea: should they be protected areas?
No full textCatch composition on red shrimps (Aristaeomorpha foliacea and Aristeus antennatus) grounds in the Eastern Ionian Sea
No full textIn the present study, the catch composition and the catch per unit effort (CPUE) by weight and numbers in red shrimps’ (Aristaeomorpha foliacea and Aristeus antennatus) grounds was examined in the southern part of the eastern Ionian Sea, in order to collect important information for the Greek waters, where no deep- water fishery exists. In the depth stratum 500–700 m, the catch of the commercial species represented a high proportion (>70%) of the total catch. Red shrimps and several other commercial species were found in important quantities. The present results suggest the possibility of developing a deep-water fishery in Greece. In such a case, attention should be paid because of the high vulnerability of A. foliacea – the main deep-water fishing resource in the area – to the fishing pressure
Deep-sea distribution, biological and ecological aspects of Aristeus antennatus (Risso, 1816) in the western and central Mediterranean Sea
No full textThe object of the DESEAS Project, funded by the EC, was to gather preliminary data on the abundance and
maximum depth distribution of the rose shrimp Aristeus antennatus in the Mediterranean Sea. An exploratory survey was
therefore designed with that goal in mind and conducted on the R/V García del Cid, sampling the maximum depths in three
specific areas in the central and western Mediterranean, one off Ibiza (Balearic Islands), one off Calabria (western Ionian
Sea), and one off the southern Peloponnesian Peninsula (Gulf of Kalamata, eastern Ionian Sea). The depths sampled ranged
from 600 to 4000 m, with specimens of A. antennatus being collected down to 3300 m. There were three distinct boundaries
marking the abundance of this species: < 1000 m, relatively high abundance (up to 1000 ind km-2); 1000-1500 m, relatively
moderate abundance (up to 300 ind km-2); and > 1500 m, relatively low abundance (<100 ind km-2). The known
population structure of this shrimp species, with increasing proportions of males and juveniles with depth, was also recorded
in the deep-sea regions in other areas of the Mediterranean. No evidence of any differences in gonad development or in
the presence of spermatophores carried by females was found in any of the three sampling areas. Lastly, a tendency for the
relative proportion of juveniles to increase with depth was also observed
Deep-sea Mediterranean biology: the case of Aristaeomorpha foliacea (Risso, 1827) (Crustacea: Decapoda: Aristeidae)
No full textData on the distribution, abundance and biological parameters of the giant red shrimp Aristaeomorpha foliacea were collected during a research survey in deep waters (600-4000 m) of the Mediterranean Sea at three locations: the Balearic Sea, the western Ionian and the eastern Ionian in early summer 2001. The shrimp was mainly found in the shallower zone (< 1000 m) of the eastern Ionian Sea. Few specimens were caught in the deeper waters of this region, with 1100 m being the lower limit of its distribution. This is the maximum depth reported for the species in the Mediterranean. At the other two locations, the species was scarcely caught and only in the shallowest zone (< 1000 m). In the area and depth zone of high abundance, 5 modal groups for females and 3 for males were distinguished using the Bhattacharya method. The recruitment seems to take place at the shallowest stations (600 m). More than 50% of adult females were in advanced maturity stages. The striking abundance differences of the species between the western and eastern locations may be explained by the different exploitation level of the deep waters (almost null in the eastern Ionian Sea and extensive more westwards). However, the distribution and biological characteristics of A. foliacea indicate a higher vulnerability to over-fishing comparing to the other commercial co-occurring deep-water shrimp Aristeus antennatus
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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