1,720,958 research outputs found
Efficacité et mécanismes d'action des défensines de tiques contre le champignon phytopathogène et toxinogène Fusarium graminearum
No full textFusarium Head Blight (FHB) mainly caused by the fungus Fusarium graminearum is a devastating disease affecting cereal crops that leads to significant yield losses and a reduced grain quality. Indeed, F. graminearum produces type B trichothecene mycotoxins (TCTB) which are detrimental to the health of humans and livestock. In the present study, a peptide referred to as TickCore3 (TC3), the γ-core of the tick defensin DefMT3, was demonstrated to be a potent fungicidal agent against F. graminearum and an efficient inhibitor of the production of TCTB. The structural and physico-chemical determinants required for the peptide efficacy were clarified. Through microscopic observation, the peptide was shown to bind specifically to the fungal spore’s envelope. Furthermore, a strategy combining transcriptomic (RNA-seq) and metabolomic (LC-MS) has been implemented to unravel the mechanism of action of TC3. Significant changes in F. graminearum transcriptome such as in its metabolome were induced by TC3 exposure evidencing a multi-faceted mechanism. The results obtained during this thesis demonstrated that TC3 could be a promising candidate for the development of new eco-friendly plant protection solutions.La fusariose de l’épi (FHB), principalement causée par le champignon Fusarium graminearum, est une maladie dévastatrice qui affecte les cultures céréalières et entraîne des pertes de rendement importantes et une diminution de la qualité des grains. En effet, F. graminearum produit des mycotoxines appelées trichothécènes de type B (TCTB) qui nuisent à la santé humaine et animale. Le peptide appelé TickCore3 (TC3), γ-core de la défensine de tique DefMT3, s’est avéré être un puissant antifongique contre F. graminearum et un inhibiteur efficace de la production de TCTB. Les déterminants structuraux et physico-chimiques nécessaires à l’efficacité du peptide ont été clarifiés. Des observations microscopiques ont permis de montrer que le peptide se fixait spécifiquement à l’enveloppe des spores fongiques. En outre, une stratégie associant transcriptomique (RNA-seq) et métabolomique (LC-MS/MS) a été mise en oeuvre pour décrypter le mécanisme d’action de TC3. Des changements importants dans le transcriptome de F. graminearum, comme dans son métabolome, ont été induits par une exposition au TC3 mettant en évidence un mécanisme à multiples facettes. Les résultats obtenus au cours de cette thèse ont démontré que TC3 était un candidat prometteur pour de nouvelles solutions de protection des végétaux, alternatives aux fongicides de synthèse
Efficacy and mechanisms of action of tick defensins against the phytopathogenic and toxinogenic fungus Fusarium graminearum
No full textLa fusariose de l’épi (FHB), principalement causée par le champignon Fusarium graminearum, est une maladie dévastatrice qui affecte les cultures céréalières et entraîne des pertes de rendement importantes et une diminution de la qualité des grains. En effet, F. graminearum produit des mycotoxines appelées trichothécènes de type B (TCTB) qui nuisent à la santé humaine et animale. Le peptide appelé TickCore3 (TC3), γ-core de la défensine de tique DefMT3, s’est avéré être un puissant antifongique contre F. graminearum et un inhibiteur efficace de la production de TCTB. Les déterminants structuraux et physico-chimiques nécessaires à l’efficacité du peptide ont été clarifiés. Des observations microscopiques ont permis de montrer que le peptide se fixait spécifiquement à l’enveloppe des spores fongiques. En outre, une stratégie associant transcriptomique (RNA-seq) et métabolomique (LC-MS/MS) a été mise en oeuvre pour décrypter le mécanisme d’action de TC3. Des changements importants dans le transcriptome de F. graminearum, comme dans son métabolome, ont été induits par une exposition au TC3 mettant en évidence un mécanisme à multiples facettes. Les résultats obtenus au cours de cette thèse ont démontré que TC3 était un candidat prometteur pour de nouvelles solutions de protection des végétaux, alternatives aux fongicides de synthèse.Fusarium Head Blight (FHB) mainly caused by the fungus Fusarium graminearum is a devastating disease affecting cereal crops that leads to significant yield losses and a reduced grain quality. Indeed, F. graminearum produces type B trichothecene mycotoxins (TCTB) which are detrimental to the health of humans and livestock. In the present study, a peptide referred to as TickCore3 (TC3), the γ-core of the tick defensin DefMT3, was demonstrated to be a potent fungicidal agent against F. graminearum and an efficient inhibitor of the production of TCTB. The structural and physico-chemical determinants required for the peptide efficacy were clarified. Through microscopic observation, the peptide was shown to bind specifically to the fungal spore’s envelope. Furthermore, a strategy combining transcriptomic (RNA-seq) and metabolomic (LC-MS) has been implemented to unravel the mechanism of action of TC3. Significant changes in F. graminearum transcriptome such as in its metabolome were induced by TC3 exposure evidencing a multi-faceted mechanism. The results obtained during this thesis demonstrated that TC3 could be a promising candidate for the development of new eco-friendly plant protection solutions
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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