1,720,961 research outputs found
POLYCHLORINATED BIPHENYLS (PCBs) IN MUSCLE OF THE WILD COMMON CARP (CYPRINUS CARPIO) FROM THE LAKE PIEDILUCO
No full textPCB concentrations in freshwater wild brown trouts (Salmo trutta trutta L) from Marche rivers, Central Italy
No full textThe purpose of this study is to evaluate the degree of PCBs contamination of wild brown trouts (Salmo trutta trutta L) caught in Marche Region rivers and to study the percentage contribution of the sum of the six indicators PCBs with respect to the sum of eighteen congeners in wild brown trouts. The determination of eighteen PCBs was made on the edible portion (fillets) of trouts by GC-ECD analysis. Fish samples were collected from fourteen rivers, selected to represent the fluvial pollution in the Marche Region. The total sum of eighteen congener concentrations was 8.2±0.9 ng/g wet weight. All the analysed samples showed a high variability of their congener profile even though the six PCBs indicators stood for 49.8% of the total PCBs. In the muscle of brown trout the Σ eighteen PCB and the Σ six PCB concentrations were not statistically correlated with the length and the body mass of specimens. Total PCB (Σ eighteen PCBs and Σ six PCBs) concentrations measured in the different sampling sites showed significant statistical differences among districts and, in the same district, among rivers (p<0.01). In particular, the lowest PCB levels (p<0.01) were detected in fish caught in Pesaro-Urbino Province rivers with the mean total PCB concentrations of 102.4±6.3 ng/g fat weight while the highest PCB levels were measured in specimens coming from Macerata Province rivers (1147.8±456.6 ng/g fat weight)
Temporal trends of PCBs in feed and dietary influence in farmed rainbow trout (Oncorhynchus mykiss)
No full textAs a rainbow trout producer, Italy is accounted as fifth in the world and second in continental Europe. In this study, the levels of the eighteen PCBs in feed and in trout, showed a statistical significant difference (p< 0.01) throughout the years, with a declining trend from 2005 to 2010. This trend shows effectively that quality and safety of trout feeds has greatly improved during the last years and, as a consequence, also the PCBs values in muscle trout, showed a decreasing trend.Moreover, feed Σ18PCBs showed a statistical significant difference (p<0.01) among the analysed brands and was positively correlated (p<0.01 and r = 0.451) with the rainbow trout muscle Σ18PCBs. These results showed that the presence of PCBs in trout muscle is directly linked to the chemical quality of aquaculture feed. The most commonly detected PCBs congeners were congeners PCB 153 and PCB 138 in all the three compared brands.[...
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
NDL-POLYCHLORINATED BIPHENYLS (PCB) IN FOOD: TREE YEARS DATA FROM MARCHE AND UMBRIA REGIONS (ITALY).
No full textMicroplastics and Brominated Flame Retardants in Freshwater Fishes From Italian Lakes: Implication for Human Health
No full textMicroplastics (MPs) and brominated flame retardants (BFRs) represent a synergic threat for aquatic environments and organisms' health status, with an additional concern over food quality and food security for species of commercial interest. In this study, the ingestion of MPs, levels of polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCDs) were assessed in organisms from two lakes of Central Italy, with the aims of exploring the bioavailability of these pollutants in freshwater environments, the possible translocation of MPs from digestive to edible tissues, and the relationship between MPs ingestion and bioaccumulation of BFRs. The fish Perca fluviatilis, Anguilla anguilla, Carassus auratus, and the crayfish Procambarus clarkii, all species commercialized for human consumption, were caught in Trasimeno Lake; moreover, P. fluviatilis and Rutilus rutilus were also sampled in Piediluco, a lake strongly influenced by industrial and anthropogenic activities, where fishing for commercial purpose is forbidden. With the exception of C. auratus which showed the highest frequency of MPs ingestion (75%), species from Piediluco Lake exhibited a more elevated percentage of organisms positive to MPs ingestion (45%) and higher levels of PBDEs and HBCDs (mean values of 343 and 792 pg/g, respectively, in P. fluviatilis; 445 and 677 pg/g, respectively, in R. rutilus) than Trasimeno species (25% frequency of MPs ingestion, mean values between 6 and 163 pg/g for PBDEs and 5-107 pg/g for HBCDs). Polyester fibers dominated among MP typologies, and a high occurrence of man-made natural fibers was recorded. The number of MPs extracted in the gastrointestinal tracts of fish and soft bodies of crayfishes positive to MPs ingestion ranged between 1 and 2, whereas no MPs were found in fish filets. Given these results, the risk related to human consumption of Trasimeno organisms appears very low, whereas further investigations are required to better elucidate the possible role of MPs pollution in modulating chemical bioaccumulation in edible tissues. This study contributed to assess both environmental quality and food safety, reinforcing the use of bioindicator species for monitoring plans, in accordance with European recommendations
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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