Large-scale DNA molecular studies require reliable and efficient tools for DNA extractions. However, for some plant species and brown algae, isolation of high-quality DNA is difficult. We developed a novel method for isolating high-quality DNA from the polysaccharide-rich and polyphenol-rich brown algae based on a commercial kit and protocol (Qiagen) by optimizing the lysis step and including a chloroform ⁄ isoamyl alcohol supplementary purification step. DNAs from 24 brown algal species extracted using the original and the modified Qiagen protocol were compared for yield, quality, and effectiveness in PCR amplification. There was no significant difference in the yields between protocols. However, a statistically significant increase in DNA purity was obtained with the modified protocol, for which the A 260 ⁄ A 280 and A 260 ⁄ A 230 absorbance ratios averaged 1.66 ± 0.05 and 1.31 ± 0.01, respectively, compared to 1.37 ± 0.04 and 0.52 ± 0.04 with the original protocol. DNAs extracted by the modified procedure were more successfully amplified by PCR (nuclear, mitochondrial, and chloroplastic regions) than DNAs extracted using the original commercial kit and protocol. Importantly, the modified protocol can be applied in a high-throughput (e.g., 96-well plate) format, allowing a higher efficiency for downstream molecular analysis. In addition, improved DNA quality could increase its stability for long-term storage.
The history of the successive transformations of the Rhône-Poulenc group illustrates the complexity of the relations between companies and territories, between regional and logical interests world. One follows here all the stages of the first French chemical group : Lyons origin at the end of the XIXth century, prevalent regional bases until 1960, logical main road of the capitalism of State then, world management finally. One passed thus from a culture of industrial company to a primarily financial strategy, with an obvious loss of territorial anchoring.
Management par projet et logiques communicationnelles Le management par projet à l'épreuve des différences sociocognitives de ses acteurs Jacques Bonnet
La mutation des compétences d'encadrement et de direction est requise par la complexification du travail et des organisations. La notion de parcours semble pertinente pour traiter des changements identitaires et professionnels qui s'opèrent chez ces managers. Les six postures managériales présentées ici, témoignent de l'évolution du rapport de signification que les managers entretiennent avec leurs activités, les organisations et les autres acteurs.
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