1,721,543 research outputs found
Houghton, J. — Global warming. The complete briefing. Cambridge University Press, Cambridge. 2009
No full textErard Christian. Houghton, J. — Global warming. The complete briefing. Cambridge University Press, Cambridge. 2009. In: Revue d'Écologie (La Terre et La Vie), tome 64, n°4, 2009. pp. 380-381
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Impact of sedimentation, climate and sea level on marine sedimentary pyrite sulfur isotopes: Insights from the Valle di Manche section (Lower-Middle Pleistocene, southern Italy)
Get PDFVariations in the isotopic composition of sulfur in sedimentary pyrite (δ34Spyr) are often used to reconstruct global sulfur biogeochemical cycling and Earth's surface oxidation state over Earth history. Recent work, however, has shown that δ34Spyr is strongly impacted by local depositional conditions, which both confounds attempts to reconstruct global sulfur cycling and provides a new proxy for investigating local paleoenvironmental conditions. We present a chemostratigraphic record of δ34Spyr in a detailed paleoenvironmental and sequence stratigraphic framework spanning the Early-Mid Pleistocene transition from the Crotone Basin (Calabria, Southern Italy). Bulk δ34Spyr data parallel transgressive-regressive cycles and enable the differentiation of progradational and retrogradational stacking patterns, where δ34Spyr values decrease toward −50‰ in outer shelf deposits during late transgression and become more positive and variable in prograding sedimentary units accumulated in shallower environments. In parallel with the observed variations in δ34Spyr, complementary data on organic carbon abundance and isotopic composition and total nitrogen abundance document changes in terrestrial delivery of sediment to the basin, as a consequence of glacial-interglacial eustatic sea-level changes, regional climate and local tectonics. The chemostratigraphic record of δ34Spyr appears sensitive to variations in sedimentation rates and local erosional surfaces and therefore may represent a powerful tool to assess stratal stacking patterns for sequence stratigraphic interpretations of siliciclastic successions. These results highlight the role of local conditions in controlling sedimentary δ34Spyr records and illustrate how isotopic data can be used to reconstruct key parameters of the sedimentary environment that might not otherwise be accessible, especially in deep-time strata
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
PRM39 Resource Use Measurement In Trials Conducted In Care Homes: A Study Of Level-Of-Agreement Between Data Collected From Gp Records And Care Home Records
No full textObjectivesMethodological research focused on resource use measurement has been limited in comparison to the amount of research focussed on measuring outcomes within the economic evaluation context. This study was designed to assess the level-of-agreement between two different sources of health and social care resource use data collected on care home residents.MethodsThe methods were informed by a review of level-of-agreement studies concerned with resource use in older people. In the base case, resource use data collected from both GP medical records (electronic records) and care home records (paper-based records) on 362 care home residents were obtained as part of the CAREMED cluster randomised controlled trial. Descriptive statistics were explored before assessing level-of-agreement through percent agreement, 95% limits of agreement, and Lin’s concordance correlation coefficient (CCC). Sensitivity analyses excluded non-users and tested timeframe. Factors affecting the magnitude of difference were explored using multi-level modelling.ResultsSeveral resource items (number of GP, out of hours GP and podiatrist contacts) were found to have substantial agreement (0.61 to 0.80) between the GP records and care home records according to the CCC. The number of total visits, dietician, paramedic and SLT contacts showed moderate agreement (0.41 to 0.60). Most resources showed a poor (less than 0.00) or slight (0.00 to 0.22) level-of-agreement either due to care home records (for chiropodist, music therapy, and social worker contacts) or GP records (for phlebotomist and practice nurse) recording a greater number of visits. Patient classification (residential/nursing), number of falls, number of STOPP criteria met, number of medications and comorbidities significantly affected the magnitude of differences observed.ConclusionsThis research suggests that both sources of data are reliable for some resources but not others, indicating dual sources may be necessary where a wider perspective is important and feasible in terms of costs of data collection
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