1,721,000 research outputs found
AfuPmV-1-infected Aspergillus fumigatus is more susceptible to stress than virus-free fungus
Get PDFInfection with Aspergillus fumigatus polymycovirus 1 (AfuPmV-1) affects Aspergillus fumigatus Af293’s growth in vitro, iron metabolism, resistance in intermicrobial competition with Pseudomonas aeruginosa, resistance to osmotic stress, and resistance to the chitin synthase inhibitor nikkomycin Z. Here, we show that response to high temperature, Congo Red-induced stress, and hydrogen peroxide are also dependent on the viral infection status of A. fumigatus. AfuPmV-1- infected Af293 was more susceptible than virus-free Af293 to growth inhibition by high temperature, hydrogen peroxide, Congo Red exposure, and nutrient restriction. Increased resistance of virus-free fungus was observed when cultures were started from conidia but, in the case of high temperature and hydrogen peroxide, not when cultures were started from hyphae. This indicates that the virus impairs the stress response during the growth phase of germination of conidia and development into hyphae. In conclusion, our work indicates that AfuPmV-1 infection in A. fumigatus impairs host responses to stress, as shown by exposure to high temperature, oxidative stress such as hydrogen peroxide, and some cell wall stresses, as shown by exposure to Congo Red (in agreement with our previous observations using nikkomycin Z) and nutrient restriction
Study of the role of the families of Glycoside Hydrolases GH16, GH17 and GH55 in the morphogenesis of the opportunistic pathogen, Aspergillus fumigatus
No full textLa paroi cellulaire fongique est une couche externe et robuste composée principalement de polysaccharides, qui protège la cellule fongique de son environnement, médie l'interaction cellule-cellule et est responsable de la forme de la cellule. La paroi cellulaire du pathogène opportuniste Aspergillus fumigatus est essentiellement composée de ß(1,3)glucane qui est synthétisé au niveau de la membrane plasmique par un complexe transmembranaire puis modifié dans l'espace pariétal par des activités de ramification, de réticulation et de dégradation. La paroi cellulaire est une structure hautement dynamique qui subit des changements constants au cours de la morphogenèse fongique. Dans cette étude, nous avons étudié le rôle de trois familles de glycoside-hydrolases (GH16, GH17 et GH55) dans le remodelage du ß(1,3)glucane la paroi cellulaire de ce pathogène fongique par différentes approches. Les activités transglycosidase et glucanase respectivement de AfCrh5p et AsScw11p ont été étudiées en utilisant des protéines recombinantes et la première structure cristallographique de la famille Crh a été résolue. D’autre part, une délétion complète des gènes de chaque famille a été réalisée pour étudier la fonction biologique de ces enzymes et a mis en évidence un rôle à de multiples facettes de ces glycosides-hydrolases dans la morphogenèse du champignon filamenteux, A. fumigatus.The fungal cell wall is an outer and robust layer mainly composed of polysaccharides, which protects the fungal cell from its environment, mediates cell-cell interaction, and is responsible for the shape of the cell. The cell wall of the opportunistic pathogen Aspergillus fumigatus is essentially composed of ß(1,3)glucan which is synthesized at the plasma membrane by a transmembrane complex and then modified in the cell wall space by branching, cross-linking and degradating activities. The cell wall is a highly dynamic structure, which undergoes constant change during cell division, growth and morphogenesis. In this study, we investigated the role of three glycoside-hydrolases families (GH16, GH17 and GH55) in cell wall remodeling of this fungal pathogen by different approaches. Transglycosidase and glucanase activities of respectively AfCrh5p and AsScw11p have been studied by using recombinant proteins and the first crystal structure of the Crh family have been resolved. Furthermore, complete deletion of each family's genes has been performed to study the biological function of these enzymes and highlighted a multi-faceted role of this glycosides-hydrolases in the morphogenesis of the filamentous fungus, A. fumigatus
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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