Showing papers by "Conservatoire national des arts et métiers published in 1998"
TL;DR: Data on baseline characteristics of the participants suggest that the present sample is close to the national population in terms of geographic density, socioeconomic status, and the distribution of various major risk factors for the diseases under study.
378 citations
TL;DR: In this article, the possibilities and limits of solid-sorption cooling and heat pumping are analyzed. But, the performance of this technology takes time and it is not a feasible alternative to electrical vapour compression.
214 citations
Journal Article•
TL;DR: This report presents the rationale and discusses the justification of the design, doses and combination of antioxidant micronutrients chosen in the SU.VI.MAX study.
Abstract: The "SUpplementation en VItamines et MinerauxAntioXydants" (SU.VI.MAX) study is a randomized double-blind, placebo-controlled, primary prevention trial designed to test the efficacy of daily supplementation with antioxidant vitamins (vitamin C, 120 mg; vitamin E, 30 mg; and beta-carotene, 6 mg) and minerals (selenium, 100 micrograms; and zinc, 20 mg), at nutritional doses (one to three times the daily recommended dietary allowances), in reducing the frequency of major health problems in industrialized countries, and especially the main causes of premature death (cancers and cardiovascular diseases). The study involves 12,735 eligible subjects (women aged 35 to 60 years; men aged 45 to 60 years) included in 1994 in France. They will be followed up for 8 years. The objectives and the specific design of this intervention study are linked to its public health aim. The targeted population is the general population (not simply high-risk subjects) and the antioxidant agents tested are being administered at a level which is not pharmacologic and which may be attained by dietary intake of natural sources of these micronutrients and/or enriched foods. The amounts we are testing in the SU.VI.MAX study are those which, in observational studies have been associated with the lowest risk of diseases. This report presents the rationale and discusses the justification of the design, doses and combination of antioxidant micronutrients chosen in the SU.VI.MAX study.
187 citations
TL;DR: It appears that a low risk of pathologies may be related to multiple nutrients consumed at nutritional doses and in combination, and Optimal effects may be expected with a combination of nutrients at levels similar to those found in a healthy diet.
151 citations
TL;DR: Serum ferritin was positively correlated with meat, fish and total iron intake, and negatively correlated with dietary products consumption, calcium and fiber intake.
Abstract: The iron status of a national sample of adults living in France and participating in the SU.VI.MAX cohort, was assessed using serum ferritin and hemoglobin concentrations. Complete data were obtained for 6648 women 35-60 y old and for 3283 men 45-60 y old. Assessment of iron dietary intakes was realized on a subsample of 3111 women and 2337 men who reported six 24 h dietary records during a one-year period; 22.7% of menstruating women and 5.3% of post-menopausal women presented a total depletion of iron stores (serum ferritin < 15 microg/l). Iron-deficient anemias were found in, respectively, 4.4% and less than 1% of these women. Three-quarters of the anemias were related to iron deficiency in menstruating women. In men, iron depletion and iron deficiency anemia were very rare. Post-menopausal women had much higher serum ferritin levels than menstruating women. In menstruating women, those using intrauterine devices had significantly lower serum ferritin levels than those without contraception, and much lower than those using oral contraception. The frequency of iron depletion reached 28.1% in women using intrauterine devices, but only 13.6% in those using oral contraceptives. The mean iron intake was 16.7 +/- 5.7 mg/d in men and 12.3 +/- 3.4 mg/d in women. Heme iron represented respectively, 11.1 and 10.4% of iron intake. Ninety-three percent of menstruating women had dietary iron intakes lower than recommended dietary allowances (RDA); 52.6% consumed less than two thirds of these RDA. In post-menopausal women and men, respectively 27.7% and 3.6% had dietary intakes lower than RDA. Serum ferritin was positively correlated with meat, fish and total iron intake, and negatively correlated with dietary products consumption, calcium and fiber intake.
149 citations
01 Jun 1998
TL;DR: DEDALE is presented, a spatial database system intended to overcome some limitations of current systems by providing an abstract and non-specialized data model and query language for the representation and manipulation of spatial objects that generalizes the constraint database model of [KKR90].
Abstract: This paper presents DEDALE, a spatial database system intended to overcome some limitations of current systems by providing an abstract and non-specialized data model and query language for the representation and manipulation of spatial objects. DEDALE relies on a logical model based on linear constraints, which generalizes the constraint database model of [KKR90]. While in the classical constraint model, spatial data is always decomposed into its convex components, in DEDALE holes are allowed to fit the need of practical applications. The logical representation of spatial data although slightly more costly in memory, has the advantage of simplifying the algorithms. DEDALE relies on nested relations, in which all sorts of data (thematic, spatial, etc.) are stored in a uniform fashion. This new data model supports declarative query languages, which allow an intuitive and efficient manipulation of spatial objects. Their formal foundation constitutes a basis for practical query optimization. We describe several evaluation rules tailored for geometric data and give the specification of an optimizer module for spatial queries. Except for the latter module, the system has been fully implemented upon the O2 DBMS, thus proving the effectiveness of a constraint-based approach for the design of spatial database systems.
139 citations
TL;DR: In this article, a new family of PEO-based SPEs containing potassium hydroxide and water was thoroughly investigated in order to better understand the structure of these materials and to relate it with the interesting conducting properties observed.
97 citations
12 May 1998
TL;DR: A new technique to overcome the induced difficulties of FDD (frequency division duplex) for the design of a forward link beamformer in cellular mobile communications systems is presented, which takes advantage of the array topology at the basestation to transpose second order statistics of the propagation channel from the uplink frequency to the downlink frequency.
Abstract: A new technique to overcome the induced difficulties of FDD (frequency division duplex) for the design of a forward link beamformer in cellular mobile communications systems is presented. It takes advantage of the array topology at the basestation, used to transpose second order statistics of the propagation channel from the uplink frequency to the downlink frequency, thus enabling one to optimize directly any beamforming criterion based on these statistics at the downlink frequency, without feedback nor DOA (direction of arrival) estimation. It can be applied whatever the criterion used to design the beamformer. The effectiveness is verified by the mean of simulation results.
82 citations
TL;DR: In this paper, mixed 10-undecenoyl/3,5-dimethylphenylaminocarbonyl derivatives of amylose and chitosan were prepared and immobilized on allylsilica gel.
78 citations
01 Nov 1998
TL;DR: This paper presents a data model, based on linear constraints, dedicated to the representation and manipulation of multidimensional data, and restricts the orthographic dimension of an object O, defined as the dimension of the components O1, On such that O=O1×...× On.
Abstract: Most spatial information systems are limited to a fixed dimension (generally 2) which is not extensible. On the other hand, the emerging paradigm of constraint databases allows the representation of data of arbitrary dimension, together with abstract query languages. The complexity of evaluating queries though might be costly if the dimension of the objects is really arbitrary. In this paper, we present a data model, based on linear constraints, dedicated to the representation and manipulation of multidimensional data. In order to preserve a low complexity for query evaluation, we restrict the orthographic dimension of an object O, defined as the dimension of the components O1 ,..., On such that O=O1×...× On. This allows to process queries independently on each component, therefore achieving a satisfying trade-off between design simplicity, expressive power of the query language and efficiency of query evaluation. We illustrate these concepts in the context of spatio-temporal databases where space and time are the natural components. This data model has been implemented in the DEDALE system and a spatio-temporal application, with orthographic dimension 2, is currently running, thus showing the practical relevance of the approach.
75 citations
TL;DR: In this article, the effect of mixing has been tested on the extractable activities of lipoxygenase, peroxidase, and catalase from dough after 2, 5, and 20 min of mixing.
Abstract: The effect of mixing has been tested on the extractable activities of lipoxygenase, peroxidase, and catalase from dough after 2, 5, and 20 min of mixing, and 30 min of rest period after 20 min of mixing. Different mixing conditions have been studied including temperature, atmosphere, speed, amount of water added to the dough, buffer solutions between pH 3.6 and 7.5 added to the dough, and different additives (linoleic acid, guaiacol, hydrogen peroxide, ascorbic acid, cysteine, yeast, and sodium chloride). In all the mixing conditions tested, the dough peroxidase activity remains equivalent to the initial flour activity, whereas losses in lipoxygenase and catalase activities largely varied according to mixing conditions. The results show that a self-destruction mechanism as well as physicochemical denaturation are responsible for these losses. Lipoxygenase losses seem mainly associated with the former mechanism, whereas catalase losses are highly increased in acidic conditions (physicochemical den...
TL;DR: In this article, an analysis of the behavior of the PMR-15 polyimide alone has been performed under thermomechanical loading conditions corresponding to military aeroengine applications.
Abstract: To establish the constitutive equations for carbon/PMR-15 composites and to determine the contribution of the matrix to the mechanical response, an analysis of the behavior of the PMR-15 polyimide alone has been performed under thermomechanical loading conditions corresponding to military aeroengine applications. In particular, the creep behavior of the material has been studied for several combinations of stress (0.3 to 0.7 σr), temperature (250 to 300°C), and time (5 and 1300 h). The creep compliance has been modeled in the field where the behavior is linear, using the Burgers model, together with a retardation time distribution for the viscoelastic region. The viscoelastic behavior is described satisfactorily by the Kohlrausch function, and combined with the Maxwell relation, enables the creep compliance of PMR-15 polyimide to be modeled in the temperature range considered for short loading times. For long times at 250°C and 0.3 σr, the polymer undergoes slow plastic deformation, but nevertheless, conserves its overall viscoelastic properties. There is no equivalence between time and temperature. The master curve, constructed graphically on the basis of linear viscoelastic strains, short times, and a reference temperature of 250°C, deviates quite significantly from the experimental curve at longer times. In the latter case, the creep compliance curve can be correctly fitted to a simple power law. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1983–1991, 1998
TL;DR: In this paper, the design of an intrinsically passive controller having a Hamiltonian structure plus dissipation was presented, and it was shown that this does not imply the necessity of measuring the port variables for implementation purposes.
TL;DR: This study demonstrates the efficacy of an intake of antioxidant vitamins and trace elements, given at nutritional doses, on biochemical indicators of vitamin and trace element status.
Abstract: Objective: To test the impact of supplementation with nutritional doses of antioxidant nutrients on biochemical indicators of vitamin and trace element levels.Design: A randomized double-blind trial was performed comparing two groups receiving daily either a combination of vitamins (beta-carotene, 6 mg; vitamin C, 120 mg; and vitamin E, 30 mg) and trace elements (zinc, 20 mg; and selenium, 100 μg); or a placebo.Subjects: 401 subjects (166 males aged 45 to 60 years and 235 females aged 35 to 60 years).Measure of outcome: Biological markers of vitamin and trace element status and free radical parameters were measured initially, 3 months, and 6 months after supplemention.Results: Mean serum concentrations of alpha-tocopherol, vitamin C, beta-carotene, zinc and selenium increased significantly after 3 months of supplementation in the group receiving multivitamins associated with minerals. At baseline, 18.2% of the men and 5.1% of the women had low concentrations of serum vitamin C (<20 μmol/l); 2.4% of the me...
TL;DR: Early investigations on piezoelectric plates were based on a priori mechanical and experimental considerations as mentioned in this paper, assuming plane stress and considering only transverse components of electric displace.
Abstract: Early investigations on piezoelectric plates were based on a priori mechanical and experimental considerations. They assume plane stress and consider only transverse components of electric displace...
TL;DR: In this article, exogenous wheat lipase was added to flour (15 lipase units [LU] per gram of dry matter) to obtain substantial modification of nonpolar lipids during dough mixing.
Abstract: In control dough, endogenous wheat lipase was inactive, because the triacylglycerol (TAG), 1,2-diacylglycerol (DAG1,2), and 1,3-diacylglycerol (DAG1,3) fractions of nonpolar lipids were not affected by mixing. Conversely, the free fatty acid (FFA) and monoacylglycerol (MAG) fractions decreased, mainly due to the oxidation of polyunsaturated fatty acids (PUFA) catalyzed by wheat lipoxygenase. Addition of exogenous lipase to flour (15 lipase units [LU] per gram of dry matter) resulted in substantial modification of nonpolar lipids during dough mixing. Due to the 1,3 specificity of the lipase used in this experiment, the TAG and DAG1,3 fractions decreased, whereas the MAG and FFA fractions increased. The DAG1,2 fraction increased at the beginning of mixing and decreased after 40 min of mixing. Moreover, part of the PUFA released by lipase activity was oxidized by wheat lipoxygenase, resulting in major losses of PUFA. Conversely, the net content of the saturated and monounsaturated fatty acids (SMUFA...
TL;DR: A new learning algorithm probabilistic self-organizing map (PRSOM) using a Probabilistic formalism for topological maps that approximates the density distribution of the input set with a mixture of normal distributions is proposed.
16 Dec 1998
TL;DR: In this paper, a constructive procedure to modify the total energy function of forced Hamiltonian systems with dissipation in order to generate Lyapunov functions for non-zero equilibria is proposed.
Abstract: We propose a constructive procedure to modify the total energy function of forced Hamiltonian systems with dissipation in order to generate Lyapunov functions for non-zero equilibria. A key step in the procedure, which is motivated from energy-balance considerations standard in network modeling of physical systems, is to embed the system into a larger Hamiltonian system for which a series of Casimir functions (i.e., first integrals) can be easily constructed. For linear systems the resulting Lyapunov function is the incremental energy, thus our derivations provide a physical explanation to it. An easily verifiable necessary and sufficient condition for the applicability of the technique in the general nonlinear case is given. Some examples that illustrate the method are given.
TL;DR: The photophysical and complexing properties of a fluoroionophore consisting of coumarin 343 linked to monoaza-15-crown-5 are reported in acetonitrile and ethanol as discussed by the authors.
Abstract: The photophysical and complexing properties of a fluoroionophore consisting of coumarin 343 linked to monoaza-15-crown-5 are reported in acetonitrile and ethanol. The amide link between the coumarin and the crown precludes pH sensitivity of the tertiary amine bridging group. Upon complexation by calcium and magnesium cations, the photophysical properties undergo marked changes, whereas the effects are insignificant or very weak with alkali metal ions. I.R. spectra were recorded in deuterated acetonitrile in order to unravel the participation of the carbonyl groups in the complexation. The stoichiometry of the complexes is 1:1 apart from the case of complexation with calcium in acetonitrile where two complexes can be formed. The stability constants of the complexes were determined in acetonitrile and ethanol.
TL;DR: In this paper, a double-channel Fabry-Perot etalon and laser diodes emitting around 780 nm were used to measure the air-refractive index with an experimental uncertainty of 2 × 10-8.
Abstract: A new system, consisting of a double-channel Fabry–Perot etalon and laser diodes emitting around 780 nm, is described and proposed for use for measuring air-refractive index. The principle of this refractometer is based on frequency measurements between optical laser sources. It permits quasi-instantaneous measurement with a resolution of better than 10-9 and uncertainty in the 10-8 range. Some preliminary results on the stability of this system and the measurements of the refractive index of air with this apparatus are presented. The first measurements of the index of air at 780 nm are, within an experimental uncertainty of the order of 2 × 10-8, in agreement with the predicted values by the so-called revised Edlen equations. This result is, to the best of our knowledge, the first to extend to the near IR the validity of the revised Edlen equation derived for the wavelength range of 350–650 nm.
TL;DR: In this article, the chromatographic behavior of a 10-undecenoate/3,5-dimethylphenylcarbamate of cellulose bonded on allylsilica gel is tested using four organic mobile phase modifiers (2-propanol, chloroform, tetrahydrofuran and ethyl acetate).
01 Jan 1998
TL;DR: In this paper, les firmes jouent un role fondamental vis-a-vis d'une endogeneisation du changement technologique dans le cadre de strategies « win-win », aussi, a cote de la competitivite d'autres notions comme la'gouvernance' sont-elles introduites.
Abstract: Avec l'emergence de problemes globaux d'environnement dans les annees 1980, de nouvelles pratiques visent a reconcilier l'activite economique et la preservation de la qualite environnementale. Les firmes jouent un role fondamental vis-a-vis d'une endogeneisation du changement technologique dans le cadre de strategies « win-win ». Nous nous interrogeons sur le role de l'innovation technologique environnementale et sur les conditions de sa mise en oeuvre. Laisser l'initiative des choix strategiques en matiere environnementale a la seule competitivite industrielle peut conduire a des options technologiques et sociales « verrouillees » loin de toute trajectoire de soutenabilite. Aussi, a cote de la competitivite d'autres notions comme la « gouvernance » sont-elles introduites.
TL;DR: Chlorophyll and carotenoid variations of 2-d-old and 10-D-old bean leaves (Phaseolus vulgaris var Red Kidney) were analyzed by HPLC during the first photoperiod of greening and the kinetics of Chl and carOTenoid accumulation are different at the two investigated developmental stages.
Abstract: Chlorophyll and carotenoid variations of 2-d-old and 10-d-old bean leaves (Phaseolus vulgaris var Red Kidney) were analyzed by HPLC during the first photoperiod of greening (16 h light + 8 h dark). The HPLC method used is suitable for the separation of cis- and trans-carotenoid isomers, Pchlide a and Chlide a as well as their esters. The main results are (1) before illumination the composition of the carotenoid pool is similar at the two developmental stages; (2) non-illuminated 2-d-old leaves are devoid of Pchlide a ester; (3) chlorophyll and carotenoid accumulation in 2-d-old leaves presented a lag phase twice longer than observed in 10-d-old ones; (4) Chlide a seems directly esterified to Chl a in 2-d-old leaves whereas esterification requires four steps in 10-d-old leaves and, (5) the kinetics of Chl and carotenoid accumulation are different at the two investigated developmental stages.
TL;DR: The results indicated that the total 7a.-hydroxyDHEA produced was significantly increased in AD and may contribute to the disease-related disturbances of DHEA production and metabolism.
Abstract: Evidence has indicated that circulating adrenal steroid quantitites were significantly changed in patients with Alzheimer's disease (AD). Aside of 3 beta-sulfatation and 3 beta-acylations, levels of dehydroepiandrosterone (DHEA) result from production and metabolic transformation yields. 7 alpha-Hydroxylation of DHEA has been described in humans, and 7 alpha-hydroxy-DHEA may be responsible for the known antiglucocorticoid effects of DHEA. Using a negative ion fragmentometry method with gas chromatography/mass spectrometry on trifluoroacetate derivatives, we measured levels of free 7 alpha-hydroxy-DHEA as well as its sulfated conjugate and its fatty acid esters in serum of 10 female patients with AD and of 8 age-matched healthy control women. Free 7 alpha-hydroxy-DHEA levels in AD and controls were not significantly different (240.2 +/- 37.2 pg/ml and 206.8 +/- 21.6 pg/ml, respectively), but sulfate conjugate levels were significantly increased in AD (p = .01) (262 +/- 28.4 and 145.4 +/- 27.6, respectively) as well as fatty acid esters (p = .041) (65.7 +/- 6.9 and 40.7 +/- 9.2, respectively). These results indicated that the total 7 alpha-hydroxy-DHEA produced was significantly increased in AD (p = .024) and may contribute to the disease-related disturbances of DHEA production and metabolism.
TL;DR: Pour le travail, le taux d'ALR etait plus eleve en France en 1991 that dans d'autres pays industrialises a la meme epoque that existait de grandes disparites entre les etablissements, essentiellement liees a des facteurs structurels and organisationnels.
Abstract: Resume Objectifs Determiner l'incidence des analgesies peridurales obstetricales (APD) et les modes d'anesthesie pour cesarienne en France en 1991. Type d'etude Etude retrospective. Patientes Fichier de 84235 grossesses. Methodes Fichier etabli par tirage au sort inversement proportionnel a la taille de la maternite, pour un total de 770054 grossesses en 1991. Pour les accouchements par voie basse, les donnees recueillies etaient: APD, mode de debut d'accouchement spontane ou declenche, grossesses multiples, uterus cicatriciel. Pour les cesariennes, etaient releves les interventions programmees ou en dehors du travail, le type d'anesthesie. Etaient aussi notes la taille de la maternite, son statut (CHU, CH, etablissement prive) et le mode de garde de Panesthesiste (sur place ou en astreinte). Resultats Accouchements par voie basse. Le taux global d'APD etait de 37,2 %. Dans 5 % des maternites une APD n'etait pas realisee. Ce taux augmentait significativement avec l'activite ( P P P P P P P Conclusion Pour le travail, le taux d'ALR etait plus eleve en France en 1991 que dans d'autres pays industrialises a la meme epoque. Il existait de grandes disparites entre les etablissements, essentiellement liees a des facteurs structurels et organisationnels. Pour la cesarienne, les taux d'AG etaient eleves par rapport a ceux de la litterature.
TL;DR: In this paper, an explicit bound of the error (u - uh) was given without complex computations, and this bound was obtained without complex computation. The basic idea is to define locally an admissible vector field for the dual model, where u is a finite element approximation of u.
Abstract: Let u be the solution of the following model: $$ \left\{\begin{array}{l} \mbox{find $u \in H^1_0(\Omega)$ such that} \\ [3pt] -\Delta u = f\quad\mbox{in } \Omega, \end{array}\right. $$ where f is a given function in L2(\Omega)$ and $\Omega$ a bounded open set in $\mathbb{R}^{2}$ with a polygonal boundary. Let uh be a finite element approximation of u. The goal of this paper is to suggest an explicit bound of the error (u - uh). Furthermore, this bound is obtained without complex computations. The basic idea is to define locally an admissible vector field for the dual model.
TL;DR: In this article, a characterization of the wear mechanisms of brake disks and brake pads was carried out to define a characterization methodology, so as to identify the wear mechanism of this tribological couple, and evaluate the behavior of these new materials.
TL;DR: Using thin layer chromatography and gas chromatography-mass spectrometry, identification of 7α-hydroxy-DHEA and 7β-hydroxylation of DHEA metabolites produced in mouse liver microsome digests and kinetic studies of their production are reported.
11 May 1998
TL;DR: This preliminary work addresses the problems of 3D scenes dynamic specification and VRML browser response time for such scenes.
Abstract: We experiment the production of VRML scenes on the fly for the unguided browsing through a digitalized rare books collection. The physical appearance of books is captured by photographic textures in order to help the user evaluation of the collection relevance. In this preliminary work, we address the problems of 3D scenes dynamic specification and VRML browser response time for such scenes.
TL;DR: In this article, a single vertical heat exchanger tube with multiple spans was excited by random vibration, and the frequency response spectra and resonant peak-fitted damping ratios were calculated for all tests.
Abstract: Heat exchanger tubes can be damaged or fail if subjected to excessive flow-induced vibration, either from fatigue or fretting-wear. Good heat exchanger design requires that the designer understands and accounts for the vibration mechanisms that might occur, such as vortex shedding, turbulent excitation or fluidelastic instability. To incorporate these phenomena into a flow-induced vibration analysis of a heat exchanger requires information about damping. Damping in multispan heat exchanger tubes largely consists of three components: viscous damping along the tube, and friction and squeeze-film damping at the supports. Unlike viscous damping, squeeze-film damping and friction damage are poorly understood and difficult to measure. In addition, the effect of temperature-dependent fluid viscosity on tube damping has not been verified. To investigate these problems, a single vertical heat exchanger tube with multiple spans was excited by random vibration. Tests were conducted in air and in water at three different temperatures (25, 60, and 90 C). At room temperature, tests were carried out at five different preloads. Frequency response spectra and resonant peak-fitted damping ratios were calculated for all tests. Energy dissipation rates at the supports and the rate of excitation energy input were also measured. Results indicate that damping does not change overmore » the range of temperatures tested and friction damping is very dependent on preload.« less