Conservatoire national des arts et métiers

About: Conservatoire national des arts et métiers is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Context (language use). The organization has 3573 authors who have published 7127 publications receiving 141430 citations. The organization is also known as: CNAM & Conservatoire des arts et métiers.

Effects of different degrees of iron deficiency on cytochrome P450 complex and pentose phosphate pathway dehydrogenases in the rat.

Abstract: Four groups of weanling male rats were fed one of three iron-deficient diets (6, 18 and 23 mg iron/kg diet) or a normal iron-containing diet (41 mg iron/kg diet) for 30 d. The effects of the diets on various iron status parameters were determined and four enzymes were assayed: cytochrome P450 (P450) and NADPH cytochrome P450 reductase (P450-RED) in liver and intestine microsomes, and glucose-6-phosphate dehydrogenase (G6P-DH) and 6-phosphogluconate dehydrogenase (6PG-DH) in liver, intestine and erythrocyte cytosol. Rats fed 6 mg iron/kg diet were severely anemic, whereas rats fed 18 or 23 mg iron/kg diet were moderately or mildly iron-deficient, as shown by their hemoglobin levels, hematocrit, red blood cell parameters, erythrocyte protoporphyrin and liver iron stores. P450 concentration and P450-RED activity in liver were unaffected by iron deficiency, but P450 concentration was markedly lower in the intestine of the three iron-deficient groups than in the controls. Activities of G6P-DH and 6PG-DH were not impaired in liver or intestine, except that liver 6PG-DH activity of severely anemic rats was less than that of control rats. However, severe and moderate iron deprivation resulted in a stimulation of G6P-DH and 6PG-DH activities per million erythrocytes. These results demonstrate that even moderate iron deficiency may alter fundamental enzymatic systems intervening in drug metabolism and in the pentose phosphate pathway.

Preparation of Recycled Polypropylene/Organophilic Modified Layered Silicates Nanocomposites Part I: The Recycling Process of Polypropylene and the Mechanical Properties of Recycled Polypropylene/Organoclay Nanocomposites

Abstract: The recycling process of polypropylene (PP) and the elaboration of recycled polypropylene/modified clay nanocomposite by melt intercalation method have been investigated The purpose of this work i

Proteomic Analysis Reveals Changes in the Liver Protein Pattern of Rats Exposed to Dietary Folate Deficiency

Abstract: Epidemiologic and experimental studies showed that folate deficiency is associated with increased risk of degenerative diseases by enhancing abnormal one-carbon metabolism. We studied the changes in the proteome of liver, the main tissue of folate storage and metabolism, in a rat model of dietary folate depletion. Four-month-old rats were fed for 4 wk an amino acid-defined diet without folate and compared with pair-fed rats given the same diet adequately supplemented with folic acid. Folate deprivation decreased plasma and hepatic folate concentrations dramatically, while increasing homocysteinemia significantly. Using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight MS, we identified 9 spots corresponding to differentially expressed proteins in the liver of folate-deficient rats compared with controls. Among those spots, 4 had a significantly increased volume, whereas the volume of the 5 other spots was decreased. Upregulated proteins included glutathione peroxidase (GPx) 1 and peroxiredoxin 6, 2 enzymes involved in the response to oxidative stress, and MAWD binding protein (MAWDBP), which has been associated with cancer. MAWDBP was simultaneously identified as a second spot with a lower isoelectric point (pI) that vanished almost completely after folate deficiency. Decreased abundance was also observed for cofilin 1, a protein linked to tumorigenesis, and for the GRP 75 precursor and preproalbumin, both of which are responsive to oxidative stress and/or inflammation. Moreover, an enzyme activity assay and/or Western blot analysis of GPx-1 and MAWDBP confirmed the proteomic findings. Our results show that folate deficiency modifies the abundance of several liver proteins consistently with adaptive tissue responses to oxidative and degenerative processes.

Pricing and Inference with Mixtures of Conditionally Normal Processes

Abstract: The main objective of this paper is to exploit important properties of the mixtures of normal distributions and of conditionally normal processes in order to propose flexible and tractable discrete-time option pricing models, based on the exponential-affine stochastic discount factor (SDF) modeling principle. These models deal simultaneously and coherently with the historical and risk-neutral worlds, they can be static or dynamic and, moreover, they can be parametric or semi-parametric. In the static setting our approach provide explicit historical and risk-neutral stock returns distributions and closed-form formulas for European option prices of any residual maturity. These pricing formulas turn out to be convex combinations of Black and Scholes formulas. The previous approach is extended to the dynamic case in several ways. First, by assuming that a Mixed Normal distribution is valid for the standardized error terms. Second, by considering mixtures of conditionally Gaussian processes and, third, by adopting a semi-parametric approach which estimates the distribution of standardized error terms by mixtures of normals based on a kernel method. Some numerical exercise shows the ability of our European option pricing models to replicate implied volatility smiles, volatility skews and volatility surfaces coherently with observations.