1,720,963 research outputs found
Identification of bacterial populations in Brassica sp., Helianthus annuus and their possible role in heavy metal accumulation in plants
No full textIdentification of bacterial populations in Brassica sp., Helianthus annuus and their possible role in heavy metal accumulation in plants
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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
A potential role for bacterial endophytes in phytoremediation of heavy metal contaminated soils
No full textThis thesis aims to study the potential contribution of heavy metal resistant endophytic bacteria on heavy metal uptake and translocation processes by their host plant. The extensive study of bacterial heavy metal resistance mechanisms showed that metal bioprecipitation processes near the bacterial cell wall are often found to be a consequence of efflux based systems that reduce the bioavailable metal concentration present. Heavy metal resistant endophytic bacteria with a similar behaviour would possibly result in a lowered heavy metal bioavailability that consequently would lead to a lowered heavy metal toxicity or an improved heavy metal accumulation within the host plant. Based on this concept, new strategies to improve phytoremediation would be developed.Deze thesis heeft als doel de potentiële bijdrage van zware metalen resistente endofytische bacteriën op de zware metalen opname en translocatieprocessen van hun gastheerplant te bestuderen. De intensieve studie van de bacteriële zware metalen resistentiemechanismen toonde immers aan dat metaal bioprecipitatie processen ter hoogte van de bacteriële celwand dikwijls optreden als gevolg van efflux gebaseerde systemen die de aanwezige biologisch beschikbare zware metalen reduceren. In analogie hiermee zou de aanwezigheid van zware metaal resistente endofyten kunnen resulteren in een verlaagde biologische beschikbaarheid van de zware metalen in de plant wat tot een verminderde zware metaal toxiciteit of verbeterde zware metaalaccumulatie in de plant kan leiden. Hierop gebaseerd kunnen strategieën voor een verbeterde fytoremediatie van zware metalen worden ontwikkeld
A potential role for bacterial endophytes in phytoremediation of heavy metal contaminated soils
No full textThis thesis aims to study the potential contribution of heavy metal resistant endophytic bacteria on heavy metal uptake and translocation processes by their host plant. The extensive study of bacterial heavy metal resistance mechanisms showed that metal bioprecipitation processes near the bacterial cell wall are often found to be a consequence of efflux based systems that reduce the bioavailable metal concentration present. Heavy metal resistant endophytic bacteria with a similar behaviour would possibly result in a lowered heavy metal bioavailability that consequently would lead to a lowered heavy metal toxicity or an improved heavy metal accumulation within the host plant. Based on this concept, new strategies to improve phytoremediation would be developed.Deze thesis heeft als doel de potentiële bijdrage van zware metalen resistente endofytische bacteriën op de zware metalen opname en translocatieprocessen van hun gastheerplant te bestuderen. De intensieve studie van de bacteriële zware metalen resistentiemechanismen toonde immers aan dat metaal bioprecipitatie processen ter hoogte van de bacteriële celwand dikwijls optreden als gevolg van efflux gebaseerde systemen die de aanwezige biologisch beschikbare zware metalen reduceren. In analogie hiermee zou de aanwezigheid van zware metaal resistente endofyten kunnen resulteren in een verlaagde biologische beschikbaarheid van de zware metalen in de plant wat tot een verminderde zware metaal toxiciteit of verbeterde zware metaalaccumulatie in de plant kan leiden. Hierop gebaseerd kunnen strategieën voor een verbeterde fytoremediatie van zware metalen worden ontwikkeld
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