1,720,958 research outputs found
Metanalytical assessment of reference values for polychlorinated biphenyl in human blood
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Assessment Of Neurobehavioral Performance As A Function Of Current And Cumulative Lead Exposure.
No full textGoing 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
Biological monitoring as a valid tool to assess occupational exposure to mixtures of 2,4-:2,6-toluene diisocyanate
No full textBackground and Objectives: Despite its advantages over environmental monitoring, biological monitoring of
exposure to 2,4-:2,6-toluene diisocyanate (TDI) mixtures is still underused. The present study was designed in order
to evaluate the feasibility and reliability of biological monitoring in a factory producing polyurethane foam
blocks. Methods: Airborne TDI isomers were sampled by both static and personal pumps and determined by
HPLC with fluorimetric detection. Specific metabolites 2,4- and 2,6-toluenediamine (TDA) were determined by
gas chromatography-mass spectrometry on hydrolysed urine samples collected from 16 workers at the beginning of
the workweek and both before (BS) and at the end (ES) of the 4th workday. Additional samples were collected at the
end of the 1st half-shift and at the beginning of the 2nd half-shift in 5 workers. Results: In the foam production
shop, TDI values were on average about 20 μg/m3, with higher levels in the 2nd half-shift and peak levels in workers
operating along the polymerization tunnel. Average TDI levels were significantly correlated with ES TDA
concentrations (p<0.0001). TDA showed a fast urinary elimination phase leading to progressively higher TDA
levels either during the shift (5 workers) and at the end-of-shift. A slower elimination phase with a weekly accumulation
was demonstrated by values at the beginning of the workweek (higher than in unexposed subjects) and by
their elevation in subsequent BS samples. Conclusions: The study demonstrates the feasibility and reliability of
biological monitoring in workers exposed to 2,4-:2,6-TDI mixtures. This approach can provide information about
both the daily and weekly exposure levels
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
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