1,721,070 research outputs found
Effects of copper and the sea lice treatment Slice® on nutrient release from marine sediments
No full textCopper-based antifoulant paints and the sea lice treatment Slice® are widely used, and often detectable in the sediments beneath farms where they are administered. Ten-day, whole sediment mesocosm experiments were conducted to examine how increasing sediment concentrations of copper or Slice® influenced final water column concentrations of ammonium–nitrogen (NH4–N), nitrate + nitrite–nitrogen (NOX–N) and phosphate–phosphorus (PO4–P) in the presence of the non-target, benthic organisms Corophium volutator and Hediste diversicolor. Nominal sediment concentrations of copper and Slice® had significant effects on the resulting concentrations of almost all nutrients examined. The overall trends in nutrient concentrations at the end of the 10-day incubations were highly similar between the trials with either copper or Slice®, irrespective of the invertebrate species present. This suggests that nutrient exchange from the experimental sediments was primarily influenced by the direct effect of copper/Slice® dose on the sediment microbial community, rather than the indirect effect of reduced bioturbation/irrigation due to increased macrofaunal mortality
Acute toxicity of some treatments commonly used by the salmonid aquaculture industry to Corophium volutator and Hediste diversicolor: whole sediment bioassay tests
No full textThe commercial farming of Atlantic salmon, Salmo salar, typically requires the periodic application of copper-based anti-foulants and chemotherapeutic treatments, including Slice®, Excis®, Salmosan® and Aquatet®/Tetraplex® to reduce the effects of biological pests. Information on the environmental safety of any chemical agent released into the aquatic environment must be obtained before a product can be licensed for use, but such information typically exists only in confidential technical reports which can be difficult to obtain. Furthermore, different test organisms, experimental protocols and reporting procedures make comparison of the various compounds/studies difficult. Here we present a series of 10-day, whole sediment bioassay tests that determined the concentrations of emamectin benzoate (EB), cypermethrin (CP), azamethiphos (AZ) and oxytetracycline hydrochloride (OTC), the active ingredients of the aforementioned chemotherapeutants, and copper, that caused 50% mortality (LC50) in the non-target benthic crustacean, Corophium volutator. Additional whole sediment bioassays of identical design were conducted with the non-target polychaete worm, Hediste diversicolor exposed to copper and EB. C. volutator demonstrated similar sensitivity to EB and AZ, with LC50s of 153 (95% confidence intervals, CI = 119–198) and 182 (95% CI = 152–217) µg active ingredient [kg wet sediment]? 1 respectively. OTC caused 50% mortality of C. volutator at a concentration of 414 (95% CI = 233–734) µg OTC [kg wet sediment]? 1. The LC50 for H. diversicolor exposed to EB was 1368 (95% CI = 744–2516) µg EB [kg wet sediment]? 1, an order of magnitude greater than that for C. volutator. Conversely, C. volutator was able to tolerate much higher concentrations of copper than H. diversicolor, with LC50s of 193,326 (95% CI = 171,034–218,523) and 74,988 (95% CI = 61,192–91,895) µg Cu [kg wet sediment]? 1 respectively. CP was the most toxic to C. volutator of all compounds investigated, causing 50% mortality at a concentration of 5 (95% CI = 4–6) µg CP [kg wet sediment]? 1. These data allow direct inter-comparison of the toxicities of some of the commonly applied treatments used by the global salmonid aquaculture industry
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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