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Measurements of photosynthesis in mixtures reveal allelopathy between a dinoflagellate (Amphidinium carterae) and a diatom (Thalassiosira pseudonana)
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Le plaste des diatomées : centre énergétique et cible des interactions allélopathiques
No full textOne of the major forces that shape the dynamics and structure of phytoplankton communities is the direct inhibition of the metabolism of competitors thanks to the use of secondary metabolites. But our understanding of this phenomenon, called allelopathy, remains limited. Photosynthesis is an ideal probe to study allelopathic interactions between marine microalgae, simply because it is one of the main targets. We have validated a new approach allowing to dissect the photosynthetic activities of each microalgae within a mixture, allowing to reveal allelopathic interactions affecting photosynthesis. This thesis focuses on diatoms plastid which, beyond being the energetic center of the cell, also proves to be a specific target of the allelochemical compounds released by their competitors.This methodological approach made it possible to demonstrate the inhibition of the photosynthetic activity of the diatom T. pseudonana by allelochemical compounds released by the dinoflagellate A. carterae. This inhibition involves the dissipation of the electrochemical proton gradient across the thylakoids, probably by amphidinol-like molecules forming pores on biological membranes. We were also able to show two other allelopathic interactions targeting the plastid of diatoms: the role of alkyl-quinolones, released by bacteria, on the photosynthetic and respiratory electron transport chains of the diatom P. tricornutum, and the effects of the filtrate of the dinoflagellate A. minutum on the cytoplasmic and plastid membranes of the diatom C. muelleri.Une des principales forces qui façonnent la dynamique et la structure des communautés phytoplanctoniques est l'inhibition directe du métabolisme des concurrents grâce à l'utilisation de métabolites secondaires. Mais notre compréhension de ce phénomène, appelé allélopathie, reste limitée. La photosynthèse est une sonde idéale pour étudier les interactions allélopathiques entre microalgues marines, car elle en est une des cibles principales. Nous avons validé une approche nouvelle, permettant de disséquer les activités photosynthétiques de chaque microalgue au sein d’un mélange, permettant de dévoiler des interactions allélopathiques ciblant la photosynthèse. Cette thèse se concentre sur le plaste des diatomées, qui, au-delà d’être le centre énergétique de la cellule, s’avèrent aussi être la cible des composés allélochimiques libérés par leurs compétiteurs. Cette approche méthodologique a permis de montrer l’inhibition de l’activité photosynthétique de la diatomée T. pseudonana par des composés allélochimiques libérés par le dinoflagellé A. carterae. Cette inhibition implique la dissipation du gradient électrochimique de proton généré à travers les thylacoïdes, probablement par des molécules de type amphidinols formant des pores sur les membranes biologiques. Au cours de deux collaborations, nous avons montré deux autres interactions allélopathiques ciblant le plaste des diatomées : le rôle des quinolones libérées par des bactéries, sur les chaînes de transport d’électron photosynthétique et respiratoire de la diatomée P. tricornutum, les effets du filtrat du dinoflagellé A. minutum sur les membranes cytoplasmiques et chloroplastiques de la diatomée C. muelleri
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
The diatom plastid : energetic center and target of allelopathic interactions
No full textUne des principales forces qui façonnent la dynamique et la structure des communautés phytoplanctoniques est l'inhibition directe du métabolisme des concurrents grâce à l'utilisation de métabolites secondaires. Mais notre compréhension de ce phénomène, appelé allélopathie, reste limitée. La photosynthèse est une sonde idéale pour étudier les interactions allélopathiques entre microalgues marines, car elle en est une des cibles principales. Nous avons validé une approche nouvelle, permettant de disséquer les activités photosynthétiques de chaque microalgue au sein d’un mélange, permettant de dévoiler des interactions allélopathiques ciblant la photosynthèse. Cette thèse se concentre sur le plaste des diatomées, qui, au-delà d’être le centre énergétique de la cellule, s’avèrent aussi être la cible des composés allélochimiques libérés par leurs compétiteurs. Cette approche méthodologique a permis de montrer l’inhibition de l’activité photosynthétique de la diatomée T. pseudonana par des composés allélochimiques libérés par le dinoflagellé A. carterae. Cette inhibition implique la dissipation du gradient électrochimique de proton généré à travers les thylacoïdes, probablement par des molécules de type amphidinols formant des pores sur les membranes biologiques. Au cours de deux collaborations, nous avons montré deux autres interactions allélopathiques ciblant le plaste des diatomées : le rôle des quinolones libérées par des bactéries, sur les chaînes de transport d’électron photosynthétique et respiratoire de la diatomée P. tricornutum, les effets du filtrat du dinoflagellé A. minutum sur les membranes cytoplasmiques et chloroplastiques de la diatomée C. muelleri.One of the major forces that shape the dynamics and structure of phytoplankton communities is the direct inhibition of the metabolism of competitors thanks to the use of secondary metabolites. But our understanding of this phenomenon, called allelopathy, remains limited. Photosynthesis is an ideal probe to study allelopathic interactions between marine microalgae, simply because it is one of the main targets. We have validated a new approach allowing to dissect the photosynthetic activities of each microalgae within a mixture, allowing to reveal allelopathic interactions affecting photosynthesis. This thesis focuses on diatoms plastid which, beyond being the energetic center of the cell, also proves to be a specific target of the allelochemical compounds released by their competitors.This methodological approach made it possible to demonstrate the inhibition of the photosynthetic activity of the diatom T. pseudonana by allelochemical compounds released by the dinoflagellate A. carterae. This inhibition involves the dissipation of the electrochemical proton gradient across the thylakoids, probably by amphidinol-like molecules forming pores on biological membranes. We were also able to show two other allelopathic interactions targeting the plastid of diatoms: the role of alkyl-quinolones, released by bacteria, on the photosynthetic and respiratory electron transport chains of the diatom P. tricornutum, and the effects of the filtrate of the dinoflagellate A. minutum on the cytoplasmic and plastid membranes of the diatom C. muelleri
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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