1,721,037 research outputs found
Diversité linguistique et alphabétisation dans une perspective globale (LDL). Une perspective comparative des pratiques dans les pays d'Europe et d'Afrique
Get PDFProgramme à moyen terme du CELV2004 -200
THE MAJOR SECRETED CELLULASE, CELV, OF ERWINIA-CAROTOVORA SUBSP CAROTOVORA IS AN IMPORTANT SOFT-ROT VIRULENCE FACTOR
No full textCelV is the major secreted beta-1,4-endoglucanase of the phytopathogen Erwinia carotovora subsp. carotovora. Its role in virulence was investigated by comparing the ability of a cellulase-deficient mutant to cause soft rot of potato tubers with that of the wild type. A significant role was demonstrated despite the inability of CelV to effect soft rot when expressed in Escherichia coli. This established the major cellulase of E. carotovora subsp. carotovora as a virulence factor and provided evidence for a synergistic relationship between the various classes of exoenzyme in attack of potato tubers
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
MOLECULAR ANALYSIS OF THE MAJOR CELLULASE (CELV) OF ERWINIA-CAROTOVORA - EVIDENCE FOR AN EVOLUTIONARY MIX-AND-MATCH OF ENZYME DOMAINS
No full textThe structural gene for the major cellulase of Erwinia carotovora subspecies carotovora (Ecc) was isolated and expressed in Escherichia coli. Sequencing of the gene (celV) revealed a typical signal sequence and two functional domains in the enzyme; a catalytic domain linked by a short proline/threonine-rich linker to a cellulose-binding domain (CBD). The deduced amino acid sequence of the catalytic domain showed homology with cellulases of Family A, including enzymes from Bacillus spp. and Erwinia chrysanthemi CelZ, whereas the CBD showed homology with cellulases from several diverse families, supporting a ''mix-and-match'' hypothesis for evolution of this domain. Analysis of the substrate specificity of CelV showed it to be an endoglucanase with some exoglucanase activity. The pH optimum is about 7.0 and the temperature optimum about 42-degrees-C. CelV is secreted by Ecc and by the taxonomically related Erwinia carotovora subspecies atroseptica (Eca) but not by E. coli. Overproduction of the enzyme from multicopy plasmids in Ecc appears to overload the secretory mechanism
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
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