1,720,969 research outputs found
Parasites of cage cultured European seabassDicentrarchus Labraxand gilthead seabreamSparus auratafrom Sardinia (western Mediterranean): first results
Full text linkEuropean seabassDicentrarchus labraxand gilthead seabreamSparus aurataare the most important marine finfish species intensively cultured in the Mediterranean. Many factors influenced the rapid increase in the production
of these species in the last two decades. One of the most important factors is the great development and diffusion
of sea-cage culture, because some of the parasite species has become a serious threat to cage-reared fish in other Mediterranean localities
Effect of two different protein/fat ratios of the diet on meagre (Argyrosomus regius) traits
Full text linkThe aim of this study was to evaluate the effect of two diets with different protein/fat ratios (P/F) (diet
A: P/F 2.26; diet B: P/F 3.36) on the chemical composition, fatty acid profile and some somatic indexes
of meagre (Argyrosomus regius). The trial was carried out on two groups of meagre raised in two different
sea cages during 15 months. At the end of the production cycle biometric measures as well as
chemical-nutritional analysis of the fillets were conducted on 25 fishes per group. Diet A, with a lower P/F,
furnished animals with higher percentages of mesenteric fat (0.48vs0.41%; P<0.01) and of fillet yield
(51.21vs48.12; P<0.01). Moreover, the fillets obtained with the diet A showed higher percentage of fat
(3.60vs2.41%; P<0.01), lower moisture (74.10vs75.42%; P<0.01), lower losses of water under pressure
(16.73vs20.20%; P<0.01) and after 48 h of refrigeration (3.08vs4.23%; P<0.01). The fatty acids
profile of fillets was affected by the diet. Diet A resulted in a higher level of saturated fatty acids (26.44 vs
23.17% of total lipid; P<0.01) and a lower percentage of polyunsaturated fatty acids (31.56vs36.08%;
P<0.01) in the fillet, mainly due to the lower content of linoleic acid (13.63vs19.77%; P<0.01). The
atherogenic (AI) and thrombogenic (TI) indexes, which resulted very low in the fish of Group B (AI=0.48
vs 0.60, P<0.01; TI=0.33vs0.37, P<0.01), together with the low lipid content of meat in both groups,
confirmed the very high nutritional quality of meagre fillets
Influence ofMoraxellasp. colonization on the kidney proteome of farmed gilthead sea breams (Sparus aurata, L.)
Full text linkBackground:Currently, presence ofMoraxellasp. in internal organs of fish is not considered detrimental for fish farming. However, bacterial colonization of internal organs can affect fish wellness and decrease growth rate, stress resistance, and immune response. Recently, there have been reports by farmers concerning slow growth, poor feed conversion, and low average weight increase of fish farmed in offshore floating sea cages, often associated with internal organ colonization byMoraxellasp. Therefore, presence of these opportunistic bacteria deserves further investigations for elucidating incidence and impact on fish metabolism.Results:A total of 960 gilthead sea breams (Sparus aurata, L.), collected along 17 months from four offshore sea cage plants and two natural lagoons in Sardinia, were subjected to routine microbiological examination of internal organs throughout the production cycle. Thirteen subjects (1.35%) were found positive forMoraxellasp. in the kidney (7), brain (3), eye (1), spleen (1), and perivisceral fat (1). In order to investigate the influence ofMoraxellasp. colonization, positive and negative kidney samples were subjected to a differential proteomics study by means of 2-D PAGE and mass spectrometry. Interestingly,Moraxellasp. infected kidneys displayed a concerted upregulation of several mitochondrial enzymes compared to negative tissues, reinforcing previous observations following lipopolysaccharide (LPS) challenge in fish.Conclusions:Presence ofMoraxellasp. in farmed sea bream kidney is able to induce proteome alterations similar to those described following LPS challenge in other fish species. This study revealed thatMoraxellasp. might becausing metabolic alterations in fish, and provided indications on proteins that could be investigated as markers of infection by Gram-negative bacteria within farming plants
Vibrio splendidus clade associated with a disease affecting Paracentrotus lividus (Lamarck, 1816) in Sardinia (Western Mediterranean)
No full textThis work reports for the first time the so-called bald sea urchin disease of the populations of Paracentrotus lividus in Sardinia (Italy). Following the disease occurrence reported by local fishermen of about 35% on the collected specimens for commercial purpose, the phenomenon was evaluated in two areas. Animals displayed external lesions represented by loss of spines and greenish/brownish skeleton patches. Microscopy of exoskeleton and tube feet showed haemocytosis with associated bacteria; gut and intestine histopathology revealed inflammatory lesions of different type and intensity. Microbiological and molecular analysis revealed the presence of the strains belonging to the Vibrio splendidus clade. Due to the important ecological role of Paracentrotus lividus in the Mediterranean Sea, this report represents a wake-up call for the entire basin worth of further insights
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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