Valentine Rey

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Ingestion of pure fructose stimulates de novo lipogenesis and gluconeogenesis. This may however not be relevant to typical nutritional situations, where fructose is invariably ingested with glucose. We therefore assessed the metabolic fate of fructose incorporated in a mixed meal without or with glucose in eight healthy volunteers. Each participant was(More)
OBJECTIVE To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. RESEARCH METHODS AND PROCEDURES Nine healthy lean volunteers (five men and four women) were studied after 4 days of either isocaloric feeding or carbohydrate(More)
This paper focuses on the construction of statically admissible stress fields (SA-fields) for a posteriori error estimation. In the context of verification, the recovery of such fields enables to provide strict upper bounds of the energy norm of the discretization error between the known finite element solution and the unavailable exact solution. The(More)
OBJECTIVE Fructose is partly metabolized in small bowel enterocytes, where it can be converted into glucose or fatty acids. It was therefore hypothesized that Roux-en-Y gastric bypass (RYGB) may significantly alter fructose metabolism. METHODS We performed a randomized clinical study in eight patients 12-17 months after RYGB and eight control (Ctrl)(More)
OBJECTIVE To assess the short-term consequences of carbohydrate or fat overfeeding or of food restriction on the metabolic effects of mental stress in healthy lean women. RESEARCH METHODS AND PROCEDURES The effects of a sympathetic activation elicited by mental stress were evaluated in a group of healthy women after standardized isocaloric feeding (ISO)(More)
This paper deals with the estimation of the distance between the solution of a static linear mechanic problem and its approximation by the finite element method solved with a non-overlapping domain decomposition method (FETI or BDD). We propose a new strict upper bound of the error which separates the contribution of the iterative solver and the(More)
This paper deals with bounding the error on the estimation of quantities of interest obtained by finite element and domain decomposition methods. The proposed bounds are written in order to separate the two errors involved in the resolution of reference and adjoint problems : on the one hand the discretization error due to the finite element method and on(More)
Glucose-fructose ingestion increases glucose and lactate oxidation during exercise. We hypothesized that training with glucose-fructose would induce key adaptations in lactate metabolism. Two groups of eight sedentary males were endurance-trained for three weeks while ingesting either glucose-fructose (GF) or water (C). Effects of glucose-fructose on(More)
This paper investigates the possibility to estimate the discretization error of large finite element problems solved by BDD or FETI domain decomposition methods. We show that a simple processing of the fields available during the iterations enables us to compute strict error bounds where we tell the difference between the effects of the FE discretization(More)