1,720,958 research outputs found
Diversità della meiofauna in sistemi caratterizzati dalla presenza di macroalghe erette (EMA) e sistemi dominati da alghe incrostanti e ricci (ECA)
No full textTrophic status and meiofauna biodiversity in the Northern Adriatic Sea: insights for the assessment of good environmental status
Full text linkThe Descriptor 5 (Eutrophication) of the EU Marine Strategy Framework Directive aims at preventing the negative effects of eutrophication. However, in coastal systems all indicators based on water column parameters fail in identifying the trophic status and its effects on biodiversity and ecosystem functioning. We investigated benthic trophic status, in terms of sedimentary organic matter quantity, composition and quality, along with meiofaunal abundance, richness of taxa and community composition in three coastal sites (N Adriatic Sea) affected by different levels of anthropogenic stressors. We show that, on the basis of organic matter quantity and composition, the investigated areas can be classified from oligo-to mesotrophic, whereas using meiofauna as a descriptor, their environmental quality ranged from sufficient to moderately impacted. Our results show that the benthic trophic status based on organic matter variables, is not sufficient to provide a sound assessment of the environmental quality in marine coastal ecosystems. However, data reported here indicate that the integration of the meiofaunal variable allows providing robust assessments of the marine environmental statu
Ocean acidification alters meiobenthic assemblage composition and organic matter degradation rates in seagrass sediments
Full text linkSeagrass meadows are an important organic matter (OM) reservoir but, are currently being lost due to global and regional stressors. Yet, there is limited research investigating the cumulative impacts of anthropogenic stressors on the structure and functioning of seagrass benthic assemblages, key drivers of OM mineralization and burial. Here, using a 16-month field experiment, we assessed how meiobenthic assemblages and extracellular enzymatic activities (as a proxy of OM degradation) in Posidonia oceanica sediments responded to ocean acidification (OA) and nutrient loadings, at CO2 vents. P. oceanica meadows were exposed to three nutrient levels (control, moderate, and high) at both ambient and low pH sites. OA altered meiobenthic assemblage structure, resulting in increased abundance of annelids and crustaceans, along with a decline in foraminifera. In addition, low pH enhanced OM degradation rates in seagrass sediments by enhancing extracellular enzymatic activities, potentially decreasing the sediment carbon storage capacity of seagrasses. Nutrient enrichment had no effect on the response variables analyzed, suggesting that, under nutrient concentration unlikely to cause N or P imitation, a moderate increase of dissolved nutrients in the water column had limited influence on meiobenthic assemblages. These findings show that OA can significantly alter meiobenthic assemblage structure and enhance OM degradation rates in seagrass sediments. As meiofauna are ubiquitous key actors in the functioning of benthic ecosystems, we postulated that OA, altering the structure of meiobenthic assemblages and OM degradation, could affect organic carbon sequestration over large spatial scales
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
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