Search results for "milieu"
showing 10 items of 19813 documents
Efficient Online Laplacian Eigenmap Computation for Dimensionality Reduction in Molecular Phylogeny via Optimisation on the Sphere
2019
Reconstructing the phylogeny of large groups of large divergent genomes remains a difficult problem to solve, whatever the methods considered. Methods based on distance matrices are blocked due to the calculation of these matrices that is impossible in practice, when Bayesian inference or maximum likelihood methods presuppose multiple alignment of the genomes, which is itself difficult to achieve if precision is required. In this paper, we propose to calculate new distances for randomly selected couples of species over iterations, and then to map the biological sequences in a space of small dimension based on the partial knowledge of this genome similarity matrix. This mapping is then used …
Identification of a new volatile compound in onion (Allium cepa) and leek (Allium porum) : 3,4-dimethyl-2,5-dioxo-2,5-dihydrothiophene
1980
International audience
Interactions between volatiles and lipids in complex systems
1998
Partition equilibria of three aroma compounds in three different biphasic systems were studied by a liquid/liquid partition technique to investigate interactions that occur between volatiles and lipids in biphasic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl acetate, 2,5-dimethylpyrazine, and oct-1-en-3-ol. The results showed that the intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or aroma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This met…
Effects of Food Label Health and Nutrition Claims on Consumer Perceptions
2009
Two experiments are reported that examined consumers' perceptions of food package labels where health and nutrition claims were present and where they had been removed. Unlike previous studies examining the influence of information on perception, realistic materials were used. This was accomplished by presenting information on a computer as photo-realistic images of packages where claims had been removed by editing to give a without-claims condition. Automatic presentation of materials and data collection meant participants proceeded through the computer questionnaire without the presence of an experimenter. The experiment was conducted with both British and French consumers. No significant…
« Nez et langues électroniques » : bilan et perspectives pour les huiles alimentaires
2003
Le « Nez electronique », et plus recemment la « Langue electronique » ont ete fort mediatises durant la derniere decennie. Aussi est-il necessaire, avec le recul, de faire le point sur les benefices que ces technologies peuvent apporter dans le domaine des produits alimentaires, et en particulier pour huiles vegetales. On trouve une litterature relativement abondante dans ce domaine, mais les applications qui ont reussi a franchir le cap de l’utilisation industrielle sont extremement restreintes. S’agit-il d’une frilosite des industriels pour des investissements de controle-qualite ou d’un manque de fiabilite des resultats de laboratoire ? Pourtant, la demande en outils rapides de controle-…
Quelle information accompagne la distribution des Compléments Nutritionnels Oraux (CNO) à l’hôpital : un état des lieux
2019
Introduction et but de l’etude Bien que l’efficacite des Complements Nutritionnels Oraux (CNO) ait ete prouvee dans de nombreuses situations cliniques, leur utilisation en milieu hospitalier se heurte a des problematiques de prescription, de distribution et d’observance. L’objectif de l’etude etait de faire un etat des lieux des informations donnees par le personnel soignant aux patients lors de la distribution des CNO et d’etudier les representations des patients vis-a-vis de ces produits. Materiel et methodes Au cours d’une premiere phase, un observateur neutre a suivi les equipes de service et consigne tous les echanges verbaux entre soignant et patient lors de la distribution des CNO. A…
Electrochemical modifications of proteins: disulfide bonds reduction
2002
International audience; Electrochemical reduction of lysozyme disulfide bonds was achieved at pH between 10 and 11.Below pH 10, no disulfide bond cleavage was observed. At pH higher than 12, the cleavage of disulfide bonds is essentially due to hydrolysis. The addition of denaturant considerably enhanced the performance of the electrochemical device.
Fatty acid composition of french butters, with special emphasis on conjugated linoleic acid (CLA) isomers
2005
Conjugated linoleic acids (CLA) are fatty acids primarily found in dairy products. These fatty acids may have potential biological properties interesting for human health. Update of French food composition data banks was needed to determine CLA levels in French dairy products and to evaluate CLA intake by the French population. As part of this investigation, we analyzed 54 butters from local producers at different times of the year. The average CLA levels in butter were 0.45 g CLA/100 g butter in winter, 0.58 in spring, and 0.80 in summer. Regional variations of CLA levels in butters were observed from different producing areas in France. Butters from hill and mountain regions, and butters …
Association of liver steatosis with lipid oversecretion and hypotriglyceridaemia in C57BL/6j mice fed trans-10, cis-12-linoleic acid
2003
AbstractConjugated linoleic acids (CLA) have recently been recognized to reduce body fat and plasma lipids in some animals. This study demonstrated that the steatosis accompanying the fat loss induced by trans-10,cis-12-C18:2 (CLA2) and not cis-9,trans-11-C18:2 (CLA1) isomer in C57BL/6j mice was not due to an alteration of the liver lipoprotein production that was even increased. The 3-fold decrease in plasma triacylglycerol contents and the induction of mRNA expression of low-density lipoprotein receptors concomitantly observed in CLA2-fed mice suggested an increase in the lipoprotein clearance at the level of the liver itself. CLA1 feeding produced similar but attenuated effects on trigly…
Role of aroma–matrix interactions on perception of structured emulsions
2011
The impact of the composition of spreads on in vivo aroma release and aroma perception was investigated using online proton transfer reaction mass spectrometry (PTR-MS) and sensory methodologies. Consumption of model products spread on bread induced a significant increase in aroma release and better discrimination in aroma perception, compared to when the product was tasted pure from a spoon. Dynamic release of a series of 10 aroma compounds was slower with the increase in solid fat content, and the quantity decreased when proteins were added. Sensory ranking of model products mostly confirmed the release results.