1,720,970 research outputs found
Moss (Bryum radiculosum) as a bioindicator of trace metal deposition around an industrialised area in Sardinia (Italy)
No full textThe moss Bryum radiculosum (Brid.), a species typical of dry and coastal environments, was used as a bioindicator for the estimation of atmospheric trace metal deposition around the industrial site of Portoscuso (Sardinia, Italy), which includes a lead-zinc smelter, two power plants, and aluminium production factories. For Cd, Pb, Zn, and V the results showed very similar patterns with extremely high values in the immediate surroundings of the industrial area. Copper and Cr showed somewhat different patterns, but still pointing to local pollution sources. The levels of metals at distance of about 13 km from the industrial site were still higher than in background samples. In order to evaluate the suitability of B. radiculosum for monitoring studies, trace metal concentrations in moss were compared with bulk deposition measurements in the same area. Correlation was significant only for Pb, Cd, and Zn. For Cr, Cu, and V the results showed high variability, mainly to be ascribed to soil factors. (c) 2005 Elsevier Ltd. All rights reserved
Accumulation rate and inventories of 134Cs, 137Cs, 239+240 Pu, 238Pu and 241Am fallout radionuclides and atmospheric pollutants from radiodated alpine peat cores (Italy
No full textInvestigation on the Content of Uranium and Other Elements in Imported Mushrooms, From the Balkan Region
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Critical analysis of radiochemical methodologies for the assessment of sediment pollution and dynamics in the Lagoon of Venice
No full textAquatic sediments are the ultimate sink of wastes dispersed in freshwater and soil. They are therefore a useful tool for investigating
polluted ecosystems. Lagoon environments are very difficult to study due to their unstable morphology. Under these circumstances, even an
excellent environmental investigation of a restricted lagoon area would still be inadequate to appreciate the characteristics of the entire
system. The Venice lagoon is a very complex ecosystem whose morphology is complicated further by extensive anthropic intervention. A
good environmental representation of the area was obtained with a preliminary radiochemical survey of airborne radionuclides, a unique tool
in evaluating the homogeneity of the entire sedimentary system. It must be stressed, however, that the significance of the data depends
substantially on the use of qualified procedures. Based on this, a detailed study was carried out on selected homogeneous areas,
reconstructing the inventories and fluxes of pollutants in the sediments. In this work the radiochemical approach to the environmental study
of the Venice lagoon is examine
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
Fattori ambientali che modulano il contenuto di 131I e 137Cs nelle acque reflue urbane in un’area del nord Italia: il caso delle province di Padova e Vicenza
No full textVariations 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
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