1,721,012 research outputs found
Nuclear Powered Submarines as Hazards For The Marine Environment
No full textHundreds of nuclear-powered submarines (NPS) have been manufactured since 1953; some 160 are still in operation. Decommissioning NPS is a major, delicate and costly task. There have been many incidents with NPS during their 50 years operational period: Most of these emergencies resulted in serious radiological and ecological consequences. In the Mediterranean, the effects of marine pollution due to NPS have been under recent investigation following the October 2003 accident to the US nuclear submarine Hartford in Sardinia (Italy). Preliminary studies indicated that no apparent environmental release had taken place as a direct result of the accident. However, further analyses detected traces of Pu-239 in several of the algal species, indicative of anthropogenic pollutants. Furthermore, several samples showed concentrations of radially distributed alpha tracks (forming "hot spots") emanating from micron-sized point sources. The concentrated, extremely localized occurrence of these nuclides cannot be explained in terms of left-over worldwide nuclear pollution. A local source seems more plausible. Our ongoing sampling programme has revealed that: some of the high alpha/hot spot levels measured in February 2004 have decreased markedly during subsequent months, others have decreased only slightly, and others still have remained unchanged: a clear indication that different nuclides are present. We are now analyzing 2005 sample
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
Biomonitoring of Doñana National Park using the Algerian mouse (Mus spretus) as a sentinel species
No full textVariations 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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