1,720,967 research outputs found
Deoxyribonucleic acid (DNA) biosensors for environmental risk assessment and drug studies
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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
[microRNAs as biological indicators of environmental and occupational exposure to asbestos].
No full textMalignant mesothelioma is an aggressive cancer refractory to current therapies, the incidence of which is expected to rise in the next decades. Exposure to asbestos is a well known risk factor, as InternationalAgency for Research and Cancer (IARC) classified this compound as group I (carcinogenic to humans). The lack of tumor biomarkers for diagnosis and medical survey plays a fundamental role for the development of a universally accepted therapeutic approach. In this review we evaluated the mechanism of asbestos carcinogenesis by analyzing activated oncogenes, genetic predisposition, and SV40 infection as cofactors. Therefore, interest has focused on microRNAs, 19-25 nucleotide-long single-stranded RNAs that negatively regulate gene expression by modulating translational efficiency of target genes involved in numerous cellular processes including development, differentiation, proliferation, apoptosis, and stress response. The analysis revealed a differential expression of miRNAs between mesothelioma and mesothelial cells, suggesting their potential role as oncogenes or tumor suppressor genes in mesothelioma oncogenesis. We have also investigated the role of polymorphism in the etiology and pathogenesis of mesothelioma, in order to evaluate the association between disease linked to asbestos exposure andgenetic variability. The identification of dysregulated miRNAs or frequent genetic polymorphisms as potential diagnostic biomarkers or as prognostic factors for malignant mesothelioma could facilitate the surveillance procedure of subjects exposed to asbestos
Development of a multiresidue method for analyzing herbicide and fungicide residues in bovine milk based on solid-phase extraction and liquid chromatography-tandem mass spectrometry
No full textThis report describes a liquid chromatography (LC)-tandem mass spectrometry (MS) multiresidue method for determining traces of 30 base/neutral/acid herbicides and fungicides in bovine whole milk. Four milliliters of milk was spiked with the analytes and two surrogate analytes (SAs) and then diluted with 35 mL of a water/methanol solution (50:50, v/v). This mixture was passed through a 0.5-g Carbograph 4 (TM) cartridge. After washings, analytes were re-extracted by back-flushing the cartridge with 1.5 mL of methanol followed by 6 mL of methylene chloride/methanol (80:20, v/v), 50 mmol/L formic acid. After partial solvent removal down to about 0.1, 0.15 mL of I mmol/L formic acid aqueous solution and an internal standard (IS) were added. After filtration, 50 mu L of the final extract was then introduced into the LC analytical column. During the chromatographic run, the MS system was operated in both positive and negative ion modes. MS data acquisition was performed in the multi-reaction monitoring mode, selecting two precursor ion > product ion transitions for each target compound, except for pentachlorophenol. On analyzing six milk samples from different sources, absolute recovery of the analytes and the two SAs ranged between 78% and 104% with RSDs not larger than 13%. The accuracy of the method at three different spike levels was assessed by adding the two SAs to analyte-containing milk samples and varied between 82% and 120% with RSDs not larger than 11%. Limits of quantification were estimated to range between 0.008 and 1.4 mu g/L. Compared to the Carbograph 4 cartridge, one filled with a N-vinylpyrrolidone-m-divinylbenzene co-polymer (Oasis HLB (TM)) sorbent was much less efficient in recovering several of the acidic herbicides considered and, in addition, its relative final extract produced a severe negative matrix effect that drastically weakened ion signal intensities of several non acidic analytes
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