1,720,961 research outputs found
Toxicity of some synthetic pyrethroids to red swamp crayfish (Procambarus clarkii, Girard 1852) and common carp (Cyprinus carpio, L. 1758), in laboratory tests.
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Evaluation of the toxicity of synthetic pyrethroids to red swamp crayfish (Procambarus clarkii, Girard 1852) and common carp (Cyprinus carpio, L. 1758)
Full text linkThe acute toxicity of three synthetic pyrethroids (Cypermethrin, Deltamethrin and Cyfluthrin) to red swamp crayfish (Procambarus clarkii) and the mortality after long-term exposition of young common carp to Deltamethrin were determined in standardized laboratory tests.
The aim of this study was to evaluate the possibility of limiting the expansion of crayfish by the use of these compounds and the implications of their use on fish.
Red swamp crayfish experienced high sensitivity to pyrethroids as expressed by the LC50-24h: 0.14 mu g/l for Cypermethrin, 0.17 mu g/l for Cyfluthrin and 0.22 mu g/l for Deltamethrin. No mortality was observed in common carp during the long term (24 days) exposure test at initial concentration of 22.0 mu g/1 of Deltamethrin. The concentrations of Deltamethrin in muscle of crayfish and common carp were under the limit of quantification of the gas-chromatographic method in all the tests.
The results suggest that synthetic pyrethroids may be suitable to control or to eradicate nuisance populations of red swamp crayfish, in small and limited areas
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
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
Toxicity of the synthetic pyretroid Ciflutrin to the red swamp crayfish (Procambarus clarkii).
No full textSeveral experiments show that synthetic pyrethroids are toxic for freshwater crayfish. Laboratory studies were conducted to determine the acute toxicity of synthetic pyrethroid cyfluthrin (commercial formulation Solfac WP 10 -Bayer-, with 10% active ingredient) in view of a potential eradication of red swamp crayfish (Procambarus clarkii). We tested the effects of 10 different concentrations.
Cyfluthrin was highly toxic to red swamp crayfish at concentration as low as 0.04 μg/l after 48 hours of exposition. The 24-h LC50 was determined at a temperature of 20°C 1°C and calculated by graphic method. The values of the 24-h LC50 and the 48-h LC50 were respectively 0.13 μg/l and 0.08 μg/l. Neurological symptoms such as loss of coordination of the movements and paralysis occurred before the death of the crayfish. In parallel, we assessed the selectivity of the insecticide testing it in goldfish (Carassius auratus) and evaluating its toxicity and the residues in the whole carcass
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