1,721,217 research outputs found
The threshold of toxicological concern concept in risk assessment
No full textThe concept that "safe levels of exposure" for humans can be identified for individual chemicals is central to the risk assessment of compounds with known toxicological profiles. The Threshold of Toxicological Concern (TTC) is a concept that refers to the establishment of a level of exposure for all chemicals, whether or not there are chemical-specific toxicity data, below which there would be no appreciable risk to human health. The concept proposes that a low level of exposure with a negligible risk can be identified for many chemicals, including those of unknown toxicity, based on knowledge of their chemical structures. The present paper aims to describe the history of the TTC principle, its use to date, its potential future applications and the incorporation of the TTC principle in the Risk Assessment paradigm
Risk characterisation of chemicals in food and diet
Full text linkRisk characterisation of chemicals in food and diet. Renwick AG, Barlow SM, Hertz-Picciotto I, Boobis AR, Dybing E, Edler L, Eisenbrand G, Greig JB, Kleiner J, Lambe J, Muller DJ, Smith MR, Tritscher A, Tuijtelaars S, van den Brandt PA, Walker R, Kroes R. University of Southampton, Clinical Pharmacology Group, School of Medicine, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, U
Students and their parents on conflict and radicalism 1970
No full textAttitude towards the university / political attitude / family background / relation to parents with regard to education / authoritarianism of parents / experiences in high school / perspectives of future / judgement of work in general / motivations for choice of study / status of higher occupations / perception and individual judgement / opinions on the study program / authoritarianism of teachers / procedures of conflict resolution / discrepancies between actual and desired influence of students / perception of the influence of academic people in general / contact with fellow students / organizational membership / participation / activism / opinions on proposals for restructuring the university on a democratic basis / perception of existing versus ideal power-structure in the university, and in society as a whole / definition of democracy / the image of society / inequality / subjective social mobility / identification with groups / causes for tensions in the university / radicalism as an ideology / science and politics / the radical credo. Background variables: basic characteristics/ residence/ income/capital assets/ education/ politics/ religion/ organizational membershi
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
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