Showing papers by "Conservatoire national des arts et métiers published in 1989"
01 May 1989-Graphical Models \/graphical Models and Image Processing \/computer Vision, Graphics, and Image Processing
TL;DR: The technique, derived from Gordon's algorithm, accounts for visual perception criteria, namely for contour detection, and the efficiency of the algorithm is compared to Gordon's and to the classical ones.
Abstract: A digital processing technique is proposed in order to enhance image contrast without significant noise enhancement. The technique, derived from Gordon's algorithm, accounts for visual perception criteria, namely for contour detection. The efficiency of our algorithm is compared to Gordon's and to the classical ones.
363 citations
TL;DR: In this paper, the effects of the monomer molecular structure on the properties of the resulting substituted conducting poly(thiophenes) have been analyzed with as main objective the definition of the basic structural conditions for introducing a given functionalized group while preserving the electronic and electrochemical properties of a conducting backbone.
71 citations
TL;DR: The results demonstrate that even moderate iron deficiency may alter fundamental enzymatic systems intervening in drug metabolism and in the pentose phosphate pathway.
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.
51 citations
TL;DR: The results obtained imply that iron deprivation may have an adverse effect on the iron-binding properties of iron in the blood of mice.
Abstract: The consequences of iron deprivation on iron-containing enzymes of different tissues in rat and/or human is reviewed. Iron participates in a wide variety of biochemical processes, including mitochondrial electron transport, catecholamine metabolism and DNA synthesis. Recently, a broad spectrum of biochemical abnormalities resulting from iron deficiency have been described. Effects on skeletal muscle, cardiac muscle, brain tissue, liver tissue gastrointestinal tractus, body temperature regulation, DNA synthesis are successively discussed. The key liabilities of tissue iron deficiency, even at a mild degree relate to decrease in intellectual performance, and in physical capacity during exercise, alteration of temperature regulation, immune function.
34 citations
TL;DR: A necessary and sufficient ergodicity condition for complex open queueing systems that belong to a particular class of unbounded Markov stochastic Petri nets and which can include synchronization features like fork and join arrivals and departures.
Abstract: A necessary and sufficient ergodicity condition for complex open queueing systems is given. The queueing networks considered belong to a particular class of unbounded Markov stochastic Petri nets. These systems can include synchronization features like fork and join arrivals and departures, and feedback between behavior of different queues. Grouped and correlated arrivals and departures are also allowed. An example and a proof of the ergodicity results are presented. >
32 citations
Journal Article•
TL;DR: In the iron group, hemoglobin level increased significantly during the pregnancy and anemia was observed only in 3% of women at the delivery, and among the placebo group, anemia (Hb less than 11 g/dl) was observed at the end of the pregnancy in 30% ofWomen.
Abstract: An iron supplementation trial versus placebo was performed in double blind on 191 attending at 3 month the antenatal clinic of Poissy maternity. Iron status of mothers and newborns was assessed at 3, 5, 7 month, during the delivery and 2 months after the delivery, using biochemical indicators (hemoglobin level, serum ferritin). The compliance was good in 165 pregnant women (86% of the initial sample): 81 in the iron group, 84 in the placebo group. Among the placebo group, anemia (Hb less than 11 g/dl) was observed at the end of the pregnancy in 30% of women. Depletion of iron stores started at 5 month. In the iron group, hemoglobin level increased significantly during the pregnancy and anemia was observed only in 3% of women at the delivery. Iron status of newborns and two months after delivery was related to mothers iron status at delivery and particularly at the 7th month of pregnancy.
32 citations
TL;DR: In this paper, a decomposition method for minimizing quadratic pseudo-Boolean functions is proposed, where the function f is a sum of monomials of f and each monomial of f appears in at most one f"i.
17 citations
TL;DR: Asymmetric oxidation of substituted phenylacetic acids was performed using D.D.Q. as oxidizing reagent as mentioned in this paper, and the formation of a donor-acceptor intermediate complex between substrate and reagent accounted for the d.d.q. observed and the configuration of the major products obtained.
16 citations
TL;DR: In this article, the ergonomic consequences of this study affect the dimensional characteristics of the production locations or the industrial product, and further ergonomic considerations are related to the occasionally excessive physical strength limits of many populations in industrially developing countries.
15 citations
TL;DR: In this article, the chemical structure of the well-known laser dye DCM (4-dicyanomethylene-2-methyl-6-p-dimethylamino-styrl-4H-pyran) has been modified in order to increase the solubility in alcohols.
14 citations
Journal Article•
TL;DR: Children born of parents from the South Sahara were found to be at high risk for iron deficiency and iron deficiency anemia was found in 8% of 10 month olds from continental France versus 23% in the other group.
Abstract: Iron status was assessed using a combination of several biochemical indicators (serum ferritin, erythrocyte protoporphyrin, serum iron, MCV, hemoglobin) in 3,676 apparently healthy children. Children who were 10 months, 2 years and 4 years of age were selected from the population undergoing a free medical check up in a Paris Child Health Center. The prevalence of iron deficiency in children of parents from continental France was 29% in the 10 month olds, 13% in the 2 year olds and 7% in those who were 4 years of age. Corresponding figures in children born of immigrant parents were 50%, 44% and 15% respectively. Iron deficiency anemia was found in 8% of 10 month olds from continental France versus 23% in the other group. Children born of parents from the South Sahara were found to be at high risk for iron deficiency.
TL;DR: In this article, the role of qualitative prospective analysis in the business planning and forecasting context is discussed and, from the experience of application of this analysis over a decade or more, draws ten golden rules for effective strategic management.
Abstract: La prospective recognizes that the future is the raison d'etre of the present, that it is multiple and uncertain, and that it is a way for everyone to take control of their own future. This article looks at the role of such qualitative prospective analysis in the business planning and forecasting context, and, from the experience of application of this analysis over a decade or more, draws ten golden rules for effective strategic management.
01 Jan 1989
TL;DR: In this article, the synthese des deux enantiomeres de poly(thiophenes) chiraux a ete realisee is described. But this synthetise is not a complete synthetisation.
Abstract: La synthese des deux enantiomeres de poly(thiophenes) chiraux a ete realisee. Ces materiaux peuvent reconnaitre stereo-selectivement des anions chiraux lors de cycles voltametriques.
01 Jan 1989
TL;DR: In this article, the proprietors electriques du poly(cyclopenta [c] thiophene) se situent entre celles du poly (methyl-3,4,thiophene), and celles de poly (dimethyl-3-4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,33,34,35,34
Abstract: Le cyclopenta [c] thiophene, le cyclopenta [b] thiophene et le thieno [c] thiophene ont ete synthetises et leur electro- polymerisation a ete etudiee. Les proprietes electriques du poly(cyclopenta [c] thiophene) se situent entre celles du poly (methyl-3-thiophene) et celles du poly (dimethyl-3,4-thiophene).
TL;DR: Cette etude montre que la description, l'analyse et the transformation de nombreuses situations de travail requierent les connaissances combinees de l'ergonomie and de the psychopathologie.
Abstract: Cette etude montre que la description, l'analyse et la transformation de nombreuses situations de travail requierent les connaissances combinees de l'ergonomie et de la psychopathologie. Deux aspects sont abordes: la charge de travail et la securite des installations
TL;DR: In this paper, the structure of 7-aminobenzoxazinones was modified by enclosing their amino nitrogen atom in a julolidyl ring, which was expected to enhance the fluorescence performances in this series.
TL;DR: In this article, the authors examined the prospects of the main ceramics proposed as breeder materials for fusion reactors, i.e. Li2O, Li2ZrO3, LiAlO2, Li4SiO4.
TL;DR: It is suggested that glutathione content in cellular fractions may be one of the determining parameters for the mutagenic activity of B(a)P.
Abstract: The effects of vitamin A dietary intake (2 and 20 IU ∗ /g of food) on the mutagenic activity of benzo[ a ]pyrene (B(a)P) toward Salmonella typhimurium (TA98) were studied either in control rats or in animals treated by the PCB congeners 2,4,5,2′,4′,5′-hexachlorobiphenyl ((2,4,5) 2 Cl) and 3,4,3′,4′-tetrachlorobiphenyl ((3,4) 2 Cl). (3,4) 2 Cl (a planar compound) strongly increased B(a)P monooxygenase (B(a)PMO) activity and glutathione transferase, (2,4,5) 2 Cl (a non-planar PCB) was a strong inducer of epoxide hydrolase and a weak inducer of B(a)PMO. Enzyme induction was not modified by changes in vitamin A dietary intake. A higher mutagenic effect was observed in the (3,4) 2 Cl group than in the (2,4,5) 2 Cl one. This could be related to the specific form of cytochrome P-450 induced by (3,4) 2 Cl. In the untreated animals, the activation of B(a)P was higher in the 2-IU group than in the 20-IU one. Conversely, in PCB-treated rats the mutagenic activity of B(a)P was higher in the 20-IU group than in the 2-IU one. PCB induction increased the liver content of vitamin C in both the 2-IU and the 20-IU groups but only increased the glutathione levels in the 2-IU groups. This suggests that glutathione content in cellular fractions may be one of the determining parameters for the mutagenic activity of B(a)P.
TL;DR: In vitamin A-deficient rats, liver glutathione peroxidase activity was decreased, α-tocopherol content was strongly enhanced, but microsomal liquid peroxidation remained unchanged.
Abstract: In vitamin A-deficient rats, liver glutathione peroxidase activity was decreased, α-tocopherol content was strongly enhanced, but microsomal liquid peroxidation remained unchanged.
01 Jan 1989
TL;DR: The bichromophoric molecules considered in the present paper consist of two chromophores covalently linked by a molecular spacer (for instance, a polymethylene chain) so that no conjugation between them is possible.
Abstract: The bichromophoric molecules considered in the present paper consist of two chromophores covalently linked by a molecular spacer (for instance, a polymethylene chain) so that no conjugation between them is possible. Several intramolecular excited-state processes can occur in this kind of molecule (De Shryver et al., 1977a).
TL;DR: The new benzoxazinone derivative has a high molar absorbance, a good quantum yield fluorescence when it is bound to hydrophilic polypeptides and its fluorescence intensity is not dependent on pH in the physiological pH range.
01 Jan 1989
TL;DR: In this paper, the main contresens associe aux generateurs a polymeres conducteurs est celui relatif a la puissance, which depend essentiellement de la densite de courant maximum par unite de surface d'electrode fonction en general de la resistivite de l’electrolyte and de la diffusion.
Abstract: Les polymeres conducteurs electroniques ont deja suscite beaucoup d’interet parmi les scientifiques et les centres de recherche industriels du monde entier. La decouverte par Shirakawa d’une methode de synthese permettant d’obtenir des films de polyacetylene souples et mecaniquement resistants, puis l’exploitation de ce materiau par le professeur Mac Diarmid dans le domaine des generateurs electrochimiques ont largement contribue a l’engouement. Les chiffres publies ont laisse croire trop facilement que les polymeres conducteurs pourraient servir a la construction de batteries d’accumulateurs legeres, puissantes et economiques. Or les generateurs a polymeres conducteurs presentent des capacites specifiques analogues a celle du plomb - acide quand on tient compte de l’electrolyte et du solvant. Par suite de leur faible densite, les capacites volumiques sont donc beaucoup moins bonnes. Le principal contresens associe aux generateurs a polymeres conducteurs est celui relatif a la puissance. La puissance depend essentiellement de la densite de courant maximum par unite de surface d’electrode fonction en general de la resistivite de l’electrolyte et de la diffusion. La resistivite des electrolytes a base de solvants organiques utilises pour les polymeres conducteurs est cent fois plus forte que la resistivite de l’acide sulfurique ou de la potasse aqueuse utilises dans les accumulateurs commerciaux. En outre les phenomenes de dopage et de dedopage necessite des diffusions d’ions a l’interieur des masses actives qui sont tres lentes et severement limitantes dans le cas des generateurs a polymeres conducteurs. Il n’est donc pas possible avec ces derniers d’obtenir des generateurs de puissance comme cela a souvent ete suggere. Les proprietes de cyclage et d’autodecharge varient beaucoup d’un polymere a l’autre, actuellement seuls le poly pyrrole et la poly aniline semblent presenter des proprietes acceptables comme masses actives positives. Ils presentent la particularite de fournir des courbes de decharge analogues a celles des supercondensateurs; si leur fonctionnement electrochimique est similaire, ils pourraient subir sans dommage un grand nombre de cycles sans vieillissement important, pourvu que le solvant organique resiste aux tensions de fin de charge. Le poly acetylene et le poly paraphenylene presentent eux de bonnes capacite de cyclage lorsqu’ils sont utilises comme masses actives negatives. La possibilite de pouvoir effectuer un grand nombre de cycles en generateurs etanches sans entretien, avec une bonne indication de l’etat de charge sont actuellement les principales qualites associees a l’utilisation des polymeres conducteurs dans les generateurs electrochimiques.
TL;DR: Among this nutritionally vulnerable group, post-menarcheal girls and girls in their growth spurt peak had a lower serum ferritin level than the others and the effect of factors known to influence iron and folate status was specified.
Abstract: The relationships of diet, development, and maturation indices to the status of blood iron and folate indicators were studied among 233 adolescent girls aged 10-16 years. Statistically significant associations between total iron intake and hemoglobin, plasma iron, serum ferritin and transferrin saturation were observed after controlling the confounding effect of other parameters. Iron intake provided by meat was positively related to hemoglobin and serum ferritin levels. Moreover, post-menarcheal girls and girls in their growth spurt peak had a lower serum ferritin level than the others. Plasma and erythrocyte folate levels increased with increasing folate intake from vegetables and fruits. Plasma folate level decreased with decreasing folate from meat. Plasma and erythrocyte folate levels decreased with chronologic age independantly of dietary intake. Among this nutritionally vulnerable group, our results specify the effect of factors known to influence iron and folate status.
TL;DR: The project covers all mathematical topics in the French “Seconde” form in general education and provides both software for collective use and related written materials.
TL;DR: In this paper, a small, highly sensitive, inexpensive fluorimeter for the detection of very low fluorescence intensities for analytical and clinical purposes is described, which is achieved by use of an inexpensive continuous wave laser with a power of a few milliwatts.
29 Sep 1989
TL;DR: In this article, the authors present an approach based on the concept of dynamique des instances and the dynamique of classes for representation of connaissances based on le concept d objet.
Abstract: Cette etude s'inscrit dans le cadre du projet Sherpa. Ce projet a pour but de concevoir un systeme de representation de connaissances base sur le concept d'objet. L'axe privilegie du projet concerne la gestion de la dynamique des donnees et des connaissances. L'etude presentee s'interesse plus particulierement a la dynamique des instances et la dynamique des classes. La dynamique d'une instance est geree grâce a des structures. Celles-ci refletent les differents etats possibles d'incompletude et d'incoherence des instances. Ces structures sont creees a l'aide de regles heuristiques. Si une instance se deteriore, une boucle de degradation permet de gerer cette deterioration. Une instance se deteriore si elle devient moins complete et/ou moins coherente. Cependant, l'utilisateur a la possibilite d'affiner pour une application donnee le concept d'amelioration et de deterioration d'une instance. La dynamique des classes comprend leur creation et leur mise a jour. Plusieurs facons de creer une classe sont envisagees, notamment la creation d'une classe a partir d'une structure. Nous etudions, plus particulierement, l'optimisation de la mise a jour et de la reclassification des instances d'une classe modifiee.
TL;DR: An automated reactor in which reactions can be carried out using at least one gaseous reagent and one liquid reagent at a pressure of up to 5 bar is described.
Abstract: This paper describes an automated reactor in which reactions can be carried out using at least one gaseous reagent and one liquid reagent at a pressure ofup to 5 bar. The reactor was used to produce a hydrogenation reaction, in which system all operations, i.e. introduction of liquids and gases, control and regulation of pressure, temperature and volume of gases introduced and finally draining ofthe reactor, were to be automated. The system is conceived in modular form, each module being responsible for one specific task [1,2].
TL;DR: The authors examines two seemingly contradictory views of West Germany: that its economic and industrial success will continue, based on the excellent performance of its productive system and the quality of its training schemes; or that it is a power in decline due to ageing and demographic factors, weakness in the service industries, and a rigid social system.
TL;DR: In this article, the microstructure of polyoxymethylene injecte and thermodynamic properties of polymeres cristallins are investigated. But, as a consequence, the effect of microstructures on the comportement en traction of the injecte is unknown.