1,720,957 research outputs found
Biomagnification of mercury in an Antarctic marine coastal food web
No full textTotal Hg concentrations were determined in marine sediments and biota from the inner shelf of Terra Nova Bay (Antarctica). Like published data on air, snow and soils from the same region, Hg levels in the finest fraction of marine sediments were among the lowest ever reported for coastal marine environments (0.012 ± 0.007 μg g-1 dry wt). A progressive increase in Hg concentrations was found in organisms at different levels of the marine food web (phytoplankton < zooplankton and benthic primary consumers < detritivorous and opportunistic benthic invertebrates < epipelagic fish < demersal fish and plankton-feeding seabirds < fish-eating penguins < predatory birds and Weddell seal). In general, primary producers and consumers showed slightly lower Hg concentrations (0.076 ± 0.023 μg g-1 dry wt) than organisms of related species from other seas, but values in feathers (2.91 ± 1.93 μg g-1 dry wt) of the Antarctic skua and in tissues of a Weddell seal (44.0 and 24.0 μg g-1 dry wt in the liver and spleen, respectively) were similar to those in skuas and seals from the northern hemisphere. Trophic connections between organisms in well developed benthic communities, phytoplankton and fish and environmental factors such as enhanced upwelling of cold water, sea ice and low light are deemed to enhance natural biomagnification processes of Hg in the pristine Antarctic coastal environment
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
Environmental impact of trace element emission from geothermal power plants
No full textConcentrations of several trace elements were determined in mosses, higher plants and organs of small mammals from a geothermal area in Tuscany (central Italy). Increased deposition of Hg, As, B, and Sb was detected in biological samples collected within a few hundred meters of geothermal power plants. Among the species considered, the moss Hypnum cupressiforme was the most efficient accumulator of trace elements. Contamination levels in a fodder-plant (Hedysarum coronarium) and vegetables grown in the geothermal field did not seem to pose health risks for consumers. However, a statistically significant increase in Hg, B, and As concentrations was found in the kidney and muscle of small mammals living close to geothermal installations. Biological effects of B pollution were detected in two sensitive plant species. In view of plans to increase the exploitation of geothermal resources in the area, adequate measures to monitor the environment should be taken. Mosses are the most suitable accumulative biomonitors for a surveillance network, and studies on small mammal populations should be intensified. Available technologies should be used to diminish atmospheric emissions from geothermal power plants
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
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
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