1,720,957 research outputs found
Soil Salinization May Trigger Mercury Mobilisation from Contaminated Soils and Sediment
Get PDFMercury (Hg) contamination of soils is a concerning issue worldwide due to its high toxicity and risk to human health. Source of contamination, chemical form and environmental conditions affect its mobility and hence bioavailability. Contaminated coastal soils, could potentially become hotspots of Hg re-mobilisation, because of simultaneous flooding and salinization caused by sea level rise as a consequence of climate change.The aim of our work was to assess changes in Hg solubility in soils and sediments, with different type of Hg contamination, after exposure to salt and flood stresses.A soil contaminated by mining activity (mainly cinnabar-Hg) and a sediment heavily contaminated by a chlor-alkali plant (mainly elemental Hg) were collected from North-East Italy. Mercury speciation was performed either by Thermal Desorption (TD) or by a Sequential Extraction Procedure (SEP) to quantify operationally defined binding forms (soluble, exchangeable, bound to Mn or Fe oxides, bound to organic matter, non-cinnabar and cinnabar Hg forms).A bench top simulation with 0 to 32.8 g l-1 salt solution was carried out in microcosms filled with contaminated soil or sediment, to characterize flood effects on Hg mobility. Soils were kept submerged for different inundation periods (1, 7 and 30 days). After the flooding treatment, a rain event was simulated using artificial rain water. Solubilised Hg of each flood and each leaching treatment was measured by ICP-MS.Thermal desorption showed the presence of two main forms of Hg: organic bound Hg and HgS. The cinnabar-Hg peak was largely prevalent in the mine-contaminated soil, whereas the organic-bound-Hg peak was prevalent in the chlor-alkali contaminated sediment. This difference was confirmed by the liquid SEP speciation.Hg mobility increased with increasing salinity and flooding time. The effect of salt concentration was more pronounced for longer flooding periods. After 1 day of inundation, the amount of solubilised Hg was negligible, but after 7 days flooding Hg levels in the highest saline solution reached up to 0.9 and 9.3 µg Hg L-1 in the soil and in the sediment simulations, respectively. The mobility of Hg increased substantially after 30 days, and was about 22 times in the soil (19.8 µg Hg L-1) and 10 times in the sediment (89.8 µg Hg L-1) compared to the background level.Our results show a potential risk of Hg re-mobilization from contaminated coastal soils and sediments as consequence of sea level rise and their consequent salinization
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Potentially toxic elements in facultative metallophytes Biscutella laevigata and Silene vulgaris along the stream descending from the abandoned Raibl mine (Italy)
No full textThe Raibl mine, located on the Italian side of the Julian Alps, was Italy's most productive lead (Pb) and zinc (Zn) mine until operations ceased in 1991. The large volume of by-products generated several environmental problems. Potentially toxic elements (PTEs) migrated along the Rio del Lago/Slizza streams contaminating the banks. The metal tolerance of the facultative metallophytes Biscutella laevigata and Silene vulgaris has been assessed using the bioconcentration factor and translocation factor. In aboveground tissues of B. laevigata were detected 0.05-1.92 mg kg-1 of Cd, 0.21-234 mg kg-1 of Pb, 0.49-1587 mg kg-1 of Tl and 20.6-3391 mg kg-1 of Zn, and of S. vulgaris 0.01-1.60 mg kg-1 of Cd, 0.01-138 mg kg-1 of Pb, 0.01-578 mg kg-1 of Tl and 14.9-1590 mg kg-1 of Zn. Concerning the phytoremediation potential, both species have confirmed promising characteristics, but S. vulgaris should be preferred to B. laevigata for phytostabilization projects in substrates with low Tl concentrations. The high concentrations of PTEs found in the sediments of the Rio del Lago/Slizza and in the herbaceous plants collected from the watercourse banks raise concerns about the potential impact of these elements on the surrounding ecosystem
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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