Rhône-Poulenc

About: Rhône-Poulenc is a based out in . It is known for research contribution in the topics: Alkyl & Catalysis. The organization has 8909 authors who have published 8934 publications receiving 182241 citations. The organization is also known as: Rhone-Poulenc.

Characterization of Penicillium chrysogenum physiology in submerged cultures by color and monochrome image analysis.

Abstract: Although filamentous microorganisms are widely used in industrial fermentation processes, their growth and differentiation are not yet fully understood, because their biomass is structured, and therefore difficult to describe and to quantify. This lack of appropriate tools can hinder the optimization and control of the fermentation. A quantitative image analysis method was therefore developed for characterizing the physiology of the penicillin-producing mold Penicillium chrysogenum. This method is based on a differential staining procedure showing six physiological states: growing material, three differentiated states characterized by an increasing granulation, a highly vacuolized state, and dead segments having lost their cytoplasm. The image analysis software, with versions written for monochrome and color images, consisted of a semiautomatic binary mask computation step and a fully automatic segmentation step based on a fuzzy classification.

Tissue‐specific Expression of the Human Gene for Lecithin: Cholesterol Acyltransferase in Transgenic Mice Alters Blood Lipids, Lipoproteins and Lipases towards a Less Atherogenic Profile

Abstract: Lecithin:cholesterol acyltransferase (LCAT) is a key enzyme in the reverse cholesterol pathway but its role in lipid metabolism is still unclear. We have generated mice transgenic for a 7-kb genomic DNA fragment comprising the 6 exons and 5 introns of the LCAT gene with 1932 bp of 5' flanking and 908 bp of 3' flanking sequences. One line had integrated about 30 copies and expressed about 40-fold increased LCAT activity in a human test system. The expression showed correct tissue specificity of the human LCAT gene. Increased LCAT activity resulted in a decrease of plasma triacylglycerols below 50% of fasting controls. This reduction was seen in all lipoprotein fractions. Lipoprotein lipase activity did not change significantly, whereas hepatic triacylglycerol lipase increased markedly. Plasma total cholesterol was similar in fasting transgenic and control mice, but low-density lipoprotein and very low-density lipoprotein cholesterol were reduced to about 50%. High-density lipoprotein cholesterol increased about 20%, accompanied by a correspondingly increased size and a higher cholesterol efflux-stimulating activity of transgenic LCAT high-density lipoprotein. Both apolipoprotein A-I and A-II plasma concentrations increased in transgenic mice. Plasma triacylglycerol and cholesteryl ester fatty acid distribution showed an increased proportion of palmitic acid, whereas oleic, linoleic and arachidonic acid decreased, thus resembling more closely the human situation. Overexpression of the human LCAT gene provokes major changes in plasma lipoprotein and apolipoprotein concentrations, resulting in a less atherogenic plasma lipoprotein profile through a reduction in atherogenic and an increase in anti-atherogenic lipoproteins.

Régression PLS et applications

Abstract: La regression PLS permet de relier un ensemble de variables dependantes Y = {Y 1 ,...,Y P } a un ensemble de variables independantes X = {X 1 ,...,X M } lorsque le nombre de variables independantes et/ou dependantes est eleve. La regression PLS consiste a effectuer une analyse en composantes principales de l'ensemble de variables X sous la contrainte que les (pseudo-)composantes principales des X j soient aussi «explicatives» que possible de l'ensemble de variables Y. Il est alors possible de predire les Y k a partir des X j en separant mieux le signal (ce qui est synthetique, structure, commun aux donnees) du bruit (ce qui est plus specifique a l'echantillon de donnees etudie). Nous presentons la regression PLS d'un point de vue «analyse des donnees», puis exposons deux applications industrielles, l'une realisee au Centre de Recherches d'Aubervilliers et l'autre au Centre d'Industrialisation de Decines de Rhone-Poulenc. Enfin nous montrons comment utiliser la regression PLS usuelle lorsque les donnees sont qualitatives