1,721,164 research outputs found
High-resolution palaeoceanography of extreme early Pliocene carbonate-opal cycles in the eastern equatorial Pacific
No full textAlthough the modern eastern equatorial Pacific Ocean is a micronutrient-limited HNLC region, late Neogene sediments recovered from ODP Leg 138 indicate the occurrence of past high-productivity periods between the mid-Miocene and early Pliocene. These are represented by the presence of well-laminated diatom oozes (<75% opal) comprised of monospecific (95-100% Thalassiothrix longissma) and mixed diatom assemblage laminations interspersed with intervals of foram-nannofossil ooze. The monospecific laminations have been interpreted to represent episodic rapid deposition of large diatom mats from surface waters, associated with enhanced activity of tropical instability waves along the equatorial front. This study focuses on the youngest, early Pliocene laminated diatom mat interval present at ODP Site 847 and chronologically identical interval at Site 851, in which these diatom mats are absent. The aims of the project were to provide a timescale for the early Pliocene laminated diatom mat intervals, re-evaluate sedimentation rate and biogenic silica flux estimates; investigate surface hydrographic changes, organic carbon export and calcium carbonate dissolution associated with diatom mat deposition. Stable oxygen and carbon isotope records determined from benthic foraminifera were used together with existing wet bulk density records for Sites 847 and 851 to establish the lines with Site 846, which has an established time stratigraphic framework, and thus determined a new timescale for Sites 847 and 851. The onset of the early Pliocene laminated diatom mat interval was dated at 4.69 Ma and its end at 4.66 Ma. Within this interval, the average sedimentation rate during diatom mat deposition was 234 m/Ma, compared to 35 and 29 m/Ma during 'normal' sedimentation before and after the diatom mat deposits at Site 847. Diatom mat deposition resulted in average biogenic silica fluxes of 3.50-5.20 x 10-5 molSi/cm2/yr compared to fluxes of 3.53x4.13 x 10-6 molSi/cm2/yr during 'normal' sedimentation.</p
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
Involving medical students in service improvement: evaluation of a student-led, extracurricular, multidisciplinary quality improvement initiative
No full textBACKGROUND: Quality improvement (QI) is considered a duty of every doctor and, as such, it is fundamental that medical schools nurture QI skills of medical students. At a London medical school, a novel initiative was designed to involve medical students in QI. Such novel aspects include its student leadership, multidisciplinary approach and extra-curricular nature. The aim of this study is to evaluate the effectiveness of the initiative, and thus add to the experiences of existing medical student QI programs, as well as provide guidance to other institutions wishing to involve medical students in QI.METHODS: The key features of the initiative's design is described. Its effectiveness was evaluated by the collection of retrospective data on the quality of the initiative's QI projects (QIPs), including the proportion which: 1) reached completion; 2) resulted in a significant improvement in their primary outcome; 3) had sustained results at follow-up; 4) achieved publication; and 5) contributed towards a prize or conference presentation.RESULTS: There were 109 students involved throughout 10 projects from 14 different undergraduate and postgraduate courses from 2015-2019. 50% of the initiative's projects achieved a significant improvement in their primary outcome, and the proportion of projects which sustained these improvements at follow-up was 100%. Furthermore, 20% of projects were published, and 60% contributed towards a prize or conference presentation.CONCLUSION: The results of this study show that the initiative was effective at involving medical students in QI. As such, other groups establishing medical student QI programs may benefit from replicating positive elements of its design and operation.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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