1,721,034 research outputs found
Increased telomere length and mtDNA copy number induced by multi-walled carbon nanotube exposure in the workplace
No full textCarbon nanotubes (CNTs) – except MWCNT-7 - have been classified as Group 3 [ “Not classifiable as to its carcinogenicity to humans”] by the IARC. Despite considerable mechanistic evidence in vitro/ in vivo, the classification highlights a general lack of data, especially among humans. In our previous study, we reported epigenetic changes in the MWCNT exposed workers. Here, we evaluated whether MWCNT can also cause alterations in aging related features including relative telomere length (TL) and/or mitochondrial copy number (mtDNAcn). Relative TL and mtDNAcn were measured on extracted DNA from peripheral blood from MWCNT exposed workers (N = 24) and non-exposed controls (N = 43) using a qPCR method. A higher mtDNAcn and longer TL were observed in MWCNT exposed workers when compared to controls. Independent of age, sex, smoking behavior, alcohol consumption and BMI, MWCNT-exposure was associated with an 18.30 % increase in blood TL (95% CI: 7.15 to 30.62 %; p = 0.001) and 35.21 % increase in mtDNAcn (95% CI: 19.12 to 53.46 %). Our results suggest that exposure to MWCNT can induce an increase in the mtDNAcn and TL; however, the mechanistic basis or consequence of such change requires further experimental studies.sponsorship: We like to acknowledge FWO post-doctoral fellowship for Manosij Ghosh (12W7718N) and Dries S. Martens (12X9620N). (FWO|12W7718N, FWO|12X9620N)status: Published onlin
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
Human health risks of exposure to carbon nanotubes: Keeping pace with innnovation
No full textThe worldwide production of carbon nanotubes (CNTs) has increased substantially in the last decade as the material offer society new opportunities for effectively stronger, lighter, better electrically conductive, and more flexible products. However, concerns have been raised about (occupational) health risks due to CNT exposure, but understanding of the specific hazard potential of CNTs is complicated by its variability in structure and size. In addition, an accurate risk assessment is further hindered by difficulties in measuring CNT exposure and limited exposure data for the different stages of the CNT product life cycle. This thesis contributes to the safe(r) use of CNTs and provides scientific knowledge concerning 1) a comprehensive exposure assessment method for multi-walled (MW)CNTs, 2) the identification of activities and exposure determinates which significantly contributes to MWCNTs exposure across the product life cycle and 3) the observation of an indication of endothelial activation and an increased inflammatory reaction associated with MWCNT exposure. Based on the conclusions of this research the following recommendations are made: 1) The use of less hazardous functionalized forms of CNTs, which are identified based on physical and chemical characteristics of products, should be stimulated, 2) Conservative soft laws (soft regulatory agreements) could help society adapt to the pace of innovation safely and should be considered, and 3) A mandatory European exposure registration for the increasing number of workers exposed to CNTs is suggested as health effects are still largely unknown
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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