1,721,011 research outputs found
Marine ecosystem degradation
No full textKey messages
Marine ecosystem degradation involves the loss of benefits to society; it can occur as a result of natural causes or human activity.
Impacts of climate change, including ocean acidification, are inherently global. Widespread local activities can also have cumulative global effects. The many components of both kinds of impacts interact.
The rate of marine ecosystem degradation is accelerating due to economic growth and population growth.
Improved assessments of ecosystem state should be based on integrated, interdisciplinary observations that include biodiversity and ecosystem functioning.
Further international policy action is needed to reduce the drivers of marine degradation, improve marine literacy and develop a global approach to marine conservation
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
Molecular identification of picoplankton populations in contrasting waters of the Arabian Sea
Full text linkThe composition of picoplankton in the southern oligotrophic, northern mesotrophic waters and deep oxygen minimum zone (OMZ) of the Arabian Sea was determined by 16S ribosomal RNA gene cloning and fluorescence in situ hybridisation (FISH). It was hypothesised that the composition of the heterotrophic picoplankton would be different in these contrasting waters. To reduce the total diversity, cells were sorted by flow cytometry according to their scatter and DNA content before PCR amplification. The 16S rRNA clone libraries resulting from flow-sorted populations were different and often dominated by a small number of clades. Libraries from the Prochlorococcus-dominated southerly waters were dominated by sequences related to uncultured clusters of SAR11, SAR86 and Actinobacteria (HGC I). From surface waters of the Synechococcus-dominated northern part of the Arabian Sea, mostly sequences related to the uncultured gammaproteobacterial group ‘Svalbard’ and HGC I were retrieved. The clone libraries from the OMZ were also dominated by sequences falling in the clades SAR11 and SAR406, but included sequences related to those of sulfate-reducing
(Desulfosarcina, Desulfofrigus) and sulfide-oxidising bacteria (endosymbionts of Riftia and Calyptogena). With a recently developed more sensitive FISH protocol approximately 60% of all DAPI stained cells could be identified by general probes as Bacteria, Cren- or Euryarchaeota in both provinces of the Arabian Sea; 40% remained undetected. On this level and on that of the major phylogenetic groups like Alpha- and Gammaproteobacteria only minor differences were detected by FISH. However, the composition of heterotrophic picoplankton clearly differed for the proteobacterial subgroups SAR86, SAR11 and SAR116. These were more abundant in the oligotrophic waters throughout the water column than in the mesotrophic surface waters and the OMZ. This supports our original hypothesis that the contrasting waters in the Arabian Sea harbor different heterotrophic
picoplankton communities. In the future, FISH with a larger set of probes for more narrow phylogenetic groups will enable us to quantify these differences in more detail
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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