1,720,998 research outputs found
Atmospheric Dynamic Processes Affecting the Cycle of Mercury in the Mediterranean Region
No full textModelling the Atmospheric Emission, Dispersion, Transformation and Deposition of Mercury on a Mediterranean Scale
No full textPossible social relevance of illicit psychotropic substances present in the atmosphere
No full textAlthough the worldwide presence of illicit psychotropic compounds in the environment is well known, the social impact of drug abuse on the community has yet to be determined. Besides, the possibility of deriving indicators of the prevalence of drug abuse from the content of illicit substances in the air remains unexplored. In this study, the atmospheric concentrations of psychotropic compounds recorded in Italy were plotted vs. a series of criminal statistics. Meaningful links were found between atmospheric cocaine and the amount of drugs seized, the number of drug related crimes and the demand for clinical treatment recorded in the Italian regions. Atmospheric cocaine and cannabinoids also seemed to be correlated with tumour insurgence and mental disease frequency, respectively. However, further investigations are necessary to elucidate/explain/clarify if the behaviours observed for cocaine vs. the parameters usually adopted to estimate drug abuse prevalence (correspond to an effective relationships)/are directly linked, and to understand why the same approach failed when applied to cannabinoids. Moreover, according to our study illicit drugs are suspected to promote long-term ill health effects even when present at low concentrations the air. (C) 2011 Elsevier B.V. All rights reserved
Mercury Chemistry in the MBL: Mediterranean Case and Sensitivity Studies using the AMCOTS (Atmospheric Mercury Chemistry over the Sea) model
No full textThe atmospheric oxidation of mercury in the Mediterranean marine boundary layer (MBL) has been studied using the Atmospheric Mercury Chemistry over the Sea (AMCOTS) model. The model results have been compared to measured data obtained during an oceanographic research campaign in 2000, with more success than previous modelling attempts. In light of the often high concentrations of ozone present in the Mediterranean boundary layer, seasonal case studies using typical meteorological conditions and average ozone concentrations have been performed to identify the main oxidants of elemental mercury. The sensitivity of the modelled reactive gaseous mercury (RGM) concentrations to the Hg+O 3 rate constant has been assessed using the two most recent rate determinations. The results using the higher of the two literature values gives results inconsistent with measured values of RGM when the reaction between Hg and O3 is assumed to give a gas phase product. This does not necessarily indicate that the rate constant is incorrect but possibly that other rate constants in the model are overestimated or indeed that there may be reduction reactions occurring in the atmosphere which have yet to be identified. Alternatively, when the reaction product of Hg and O3 is assumed to be a solid and therefore not contribute to RGM the modelled and measured results are comparable. The deposition rates calculated by the model when compared with calculated and measured sea surface emission fluxes available in the literature indicate that dry deposition flux of RGM is comparable to the sea surface emission flux. The calculated lifetime of Hg0 in the Mediterranean MBL is between one and two weeks
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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