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International audience; Fuel cell (FC) is a promising solution in order to tackle global warming problems. Though, efforts are needed for the development of reliable tools to monitor the FC state of health and to extract useful information in order to detect possible malfunctioning. The present paper propose an original method based on the Dynamic Time Warping (DTW) technique in order to process and analyze electrochemical impedance spectroscopy data. The proposed method extracts information on the similarities between 2 EIS curves. This method is evaluated on data from start-up and shutdown experimental campaign on a high temperature PEM-FC stack. Several hundreds of EIS curves are processed over 5 different conditions. The proposed method reaches 92% of correct unsupervised classifications. From the different classes identified, the ohmic resistance is extracted in order to study the impact of 2 different start-up and shutdown protocols on the FC performance.

Background: Little is known about the influence of the ageing process on the bacterial metabolism. The aim of this work was to study the inter-individual variation and the influence of age on metabolic characteristics of the faecal microflora from persons of three age groups. Methods: Nine enzyme activities and 11 metabolites were analysed in faecal samples of 21 elderly persons (69-89 years of age), 15 adults (30-46 years of age) and 14 children (3-15 years of age). Results: They provide a pattern of the faecal microflora metabolism in a French population aged between 3 and 89 years. They showed large interindividual differences in the three groups. Although the enzyme activities were not significantly different between groups, glycolytic activities appeared less variable in adults than in elderly persons and children. The major metabolites (acetate, propionate, butyrate and L-lactate) resulting from carbohydrate fermentation were similar in the three groups. Samples from elderly persons were characteriz...

Few pharmaceutical studies, with the exception of those on rectal solutions, are described on short chain fatty acid (SCFA) formulations-especially for sodium butyrate, which is a colonocyte preferential substrate. Highly dosed butyrate pellets (90%) were prepared and their coating was designed for colonic delivery. In vivo determination (pH and transit time of pellets in rats) allowed to respectively choose the grade and thickness (resistance of 6 h) of the pH-dependent coating (Eudragi L+S, 1:1). The coated pellets were administered to naturally butyrate-deprived rats. The rats' colonic mucosa had the particularity to weakly express mitochondrial HMG-CoA synthase, an enzyme that responds to luminal butyrate. The results did not show early absorption of butyrate, but a probable cecal loss in the rat cecum as cecal residence time of the pellets was important and as pH was propitious for the coating hydrolysis. It seemed that butyrate, given daily for 7 days without the other main SCFA. was unable to induce the enzyme and/or that the dose (0.32 mmol/day) was insufficient.

In this paper, we describe a crosslingual Information Retrieval System (IRS), which makes the interrogation of multilingual databases possible. Indeed, the CEA needs to be able to process an important amount of multilingual databases and documents, and so we had to adapt the IRS we use, SPIRIT (which relies on linguistical and statistical processing) to this situation. We have thus set up a crosslingual interrogation system based on the indexation of documents containing parts written in different languages and on the bilingual reformulation of the query. The latter tries all the possible translations for every significant word of the query and the documents are used as filters in case of uncertainty or ambiguity. The answers to a query are given in the form of a list of classes of documents ranked according to their relevance. This paper describes the application of these techniques to crosslingual access to catalogs and bibliographic databases.

Gastrointestinal distribution kinetics of a large amount (0.5-1 g) of three types of non-disintegrating pellets which had the same size (S1, 710-1000 micrometers) but different densities (D1, 0.9 and D2, 1.5 g cm-3), or which had the same density (D1) but different diameters (S1 and S2, 1250-1600 micrometers) were examined in fed rats. The percentage of pellets remaining in the stomach, small gut, caecum and colon was measured at suitable intervals. Whatever the size of the pellets, the heavier the density, the longer the gastric emptying (2.1 h for D2-S1 instead of 1.3 h for D1-S1 and 0.7 h for D1-S2). The small gut transit time was not influenced by density but was slightly prolonged by size: 3.3 h for D1-S2 instead of 2.6 h for D1-S1 and D2-S1. Conversely, the gastrocolonic transit time was widely influenced by density (13.5 h for D2-S1) and somewhat by size (8.2 h for D1-S2 and 4.5 h for D1-S1). This delays were proportional to caecal residence time in the large, sacculated and derivated caecum of rats. In order to use the rat as an experimental model for pharmaceutical pellets, those results should have implication for the design of dosage forms, particularly those for controlled or timed release or those for targeted release at specific positions in the gastrointestinal tract.

Germfree suckling rats were infected with an SA11 rotavirus strain. Infected pups developed diarrhea associated with histopathological changes. The virus was detected in feces and in the small intestine. Cellular vacuolation was observed in the villi of the jejunum. These results provide a new model for further investigations of group A rotavirus infection.

Ingestion of fermented dairy products induces changes in the equilibrium and metabolism of the intestinal microflora and may thus exert a healthful influence on the host. We compared the effects of consumption of a traditional yogurt, a milk fermented with yogurt cultures and Lactobacillus casei (YC), and a nonfermented gelled milk on the fecal microflora of healthy infants. Thirty-nine infants aged 10-18 mo were randomly assigned to one of three groups in which they received 125 g/d of one of the three products for 1 mo. The following indexes were not modified during the supplementation period or for 1 wk after the end of supplementation: total number of anaerobes, bifidobacteria, bacteroides, and enterobacteria; pH; water content; concentrations of acetate, butyrate, propionate, and lactate; and bacterial enzyme activity of beta-galactosidase and alpha-glucosidase. In contrast, in the yogurt group the number of enterococci in fecal samples increased (P0.05), whereas the percentage of branched-chain and long-chain fatty acids, which are markers of proteolytic fermentation, decreased (P0.05). In the YC group, the percentage of children with6 log10 colony-forming units lactobacilli/g feces increased (P0.05), whereas the potentially harmful enzyme activity of beta-glucuronidase and beta-glucosidase decreased (P0.05). These decreases were particularly marked in those infants in the YC group in whom activity of the enzymes was initially unusually high.

BACKGROUND From 5 months of age, infants are progressively introduced to a variety of foods which influence the equilibrium of the intestinal microflora. METHODS Thirty-five children age 10-18 months from 8 day care centers in France were studied. Fecal specimens were examined for their biochemical and microbiological criteria. RESULTS Bifidobacteria and Bacteroides belong to the predominant populations (9.7 and 8.6 log 10 cfu/g, respectively). The mean level of enterobacteria and enterococci were 8.0 and 7.8 log 10 cfu/g, respectively. Only 10% of the infants presented a lactobacilli amount above 6 log 10 cfu/g. Most feces had similar pH values (mean 6.4), percentage of water (mean 76.4%), and short chain fatty acid, ammonia and lactic acid concentrations (means 77, 6.7 and 2.3 mumol/g, respectively). beta-galactosidase had the highest activity (106 IU/g of protein) and nitroreductase, the lowest (0.1 IU/g of protein). alpha-glucosidase and nitrate reductase showed intermediate values of 17 and 4 IU/g of protein, respectively. With the exception of 4 infants, beta-glucosidase and beta-glucuronidase values were low (4 and 2 IU/g of protein). Age and day care center were not significant factors for most parameters studied, except that rotavirus was related to day care center, with detection in 5 infants from the same center. CONCLUSIONS Many biochemical parameters were comparable to those found in adults, with the exception of ammonia concentration and beta-galactosidase activity. The fecal bacterial profile was different than in adults, with more Bifidobacteria than Bacteroides and higher levels of facultative anaerobes. One infant suffering from gastroenteritis had distinctive biochemical and bacterial parameters.

The effects of two levels of transgalactosylated oligosaccharide (TOS) intake on bacterial glycolytic activity, end products of fermentation and bacterial steroid transformation were studied in rats associated with a human faecal flora. Rats were fed a human-type diet containing 0, 5 or 10% TOS. Caecal pH decrease correlated with the amount of TOS in the diet. Intake of the TOS diet induced a decrease in blood cholesterol and a strong increase in beta-galactosidase activity in the hindgut. TOS fermentation led to production of hydrogen and short chain fatty acids, whereas ammonia and branched-chain fatty acids were decreased. A diet containing 10% TOS increased caecal lactic acid concentrations and reduced beta-glucuronidase activities and steroid transformation.

1. Twenty-two axenic (germfree) or thirty heteroxenic (axenic colonized with human flora) 2.5-3.5 months old female Fisher rats were fed for four weeks either a hypercholesterolemic (HYPER) diet or a HYPER diet containing 5% guar gum (GG) sterilized by heat or by gamma irradiation. 2. Axenic rats fed the irradiated GG diet had higher cholesterolemia than their counterparts fed an autoclaved diet (4.50 vs 2.29 mmol/l), whereas the method of sterilization had no effect on plasma cholesterol in axenic HYPER or heteroxenic animals (7.35 vs 6.51 mg/dl). 3. The levels of hepatic esterified cholesterol were higher in heteroxenic animals fed the irradiated GG diet than in their counterparts fed the autoclaved GG diet (5.65 vs 3.57 mmol/g tissue). 4. The composition of volatile fatty acids in the cecal content of heteroxenic rats was dependent on the method of sterilization regardless of the presence of fiber: the levels of butyrate were 2.88 and 0.85 mumol/g for rats fed the autoclaved and irradiated diets, respectively. 5. Gamma irradiation abolished the cholesterol-lowering effect of guar gum, whereas sterilization by heat preserved this effect. 6. The hypocholesterolemic effect of guar was reduced by gamma irradiation sterilization and was probably mediated by qualitative changes in the intestinal microflora which interfered with bile acid absorption.

Cet article décrit l'étude et la mise en oeuvre d'un variateur de vitesse pour machine asynchrone sans capteur mécanique et alimentée par un onduleur de tension cotrôlé en courant. Le manque d'information (2 capteurs de courants de ligne uniquement) nécessite la reconstitution fiable et précise des grandeurs fondamentales non mesurées (flux, vitesse, couple). Les résultats obtenus montrent notamment l'excellente qualité de l'estimation de vitesse, quel que soit le point de fonctionnement et en dépit des perturbations auxquelles le système est soumis. Cette étude donne lieu à la réalisation d'un variateur prototype.

Intestinal mucosal morphometry and ileal epithelial renewal were studied in conventional (CV) and germ-free (GF) rats fed either poorly digestible amylomaize or normal maize starch diets. Intestinal morphometry and position of labelled enterocytes were studied at various times after tritiated thymidine injection. With amylomaize starch diet, no difference was observed in the size of crypts (C), villi (V) and C + V between duodenum and jejunum both in CV and GF rats. In the ileum, however, values were significantly lower than those in the duodenum and jejunum. Furthermore, the presence of the microbial flora led to higher values when compared with GF values. Despite the morphological modifications in the ileum, no significant difference was detected in the labelled cell positions and epithelial renewal time between CV and GF values. This suggests that the resistant part of amylomaize starch was responsible for the modification in mucosal morphometry and the longer ileal epithelium renewal time in CV rats which then becomes similar to that in GF rats.

Presents a method to observe the rotor flux of a current-controlled induction motor. To ensure maximum robustness, a feedback loop is used to eliminate the error between actual system and model outputs. A reduced-order observation model is used to decrease the computation time. Various perturbation tests, particularly for large parameters variations have been carried out by simulation, yielding an excellent state observer performance. Some experimental results allow a check on the state observation model. >

The authors show for a simple problem where analytical calculations can be performed, the time evolution of the wavefunction describes the motion in phase space, first through the time evolution of a density pulse and secondly by considering the Wigner distribution function. In the classical limit this last distribution exhibits a very complex physically meaningless structure but by smoothing with a double gaussian kernel, the correct limit is obtained.

L'étude de la morphologie, des conditions de croissance et des gisements à pavements polygonaux du type triangulaire et hexagonal, localisés sur les coulées polycristallines de grottes, nous montre que ces formations de niveaux d'eau sont des «troncatures» (au sens physique) au sommet de rhomboèdres p et e¹. Les «troncatures » sont planes, au niveau du plan d'eau, quand celui-ci reste fixe. Elles se creusent quand le niveau est variable. On montre que la croissance de ces pavements ne se fait qu'autour et au-dessous du plan de «troncature », dans les zones immergées., Andrieux C. Étude cristallographique des pavements polygonaux des coulées polycristallines de calcite des grottes. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 86, 2, 1963. pp. 135-138.

Minéral balances of P, Ca, Mg, Na, K, Mn, Fe and Cu were determined for three groups of holoxenic rats (CV) fed a non sterilized (CVN), steamsterilized (CVA) or irradiated (CVI) diet and for two groups of axenic (GF) rats fed a steam-sterilized (GFA) or irradiated (GFI) diet. In the group of CV rats as compared to CVN group of rats, the CVA and CVI rats retained less Cu and more Fe and Mn, their urinary excretion of P and Mg was higher and they retained less Mg. Comparison between CV and GF rats showed that the apparent absorption and retention of Ca, P, Mg, Mn, Cu were higher in GF than in CV rats. On the contrary, the apparent absorption of Na and K was lower in GF than in CV rats. However, the observed differences were modified by the mode of diet sterilization. Thus, with respect to the apparent absorption of Na, K, Mn and urinary excretion of Mg, the differences between CV and GF rats were larger when the diet was irradiated than when it was steam-sterilized. On the contrary, the apparent digestibility and urinary excretion of Mg, the apparent absorption and retention of Fe were more modified when the diet was steam-sterilized than when irradiated. For some parameters of the metabolism of Na, K, Fe, Mn, Mg, and P measured in GF rats, the differences observed between GFA and GFI rats were larger than in CV rats. Accordingly, the mode of sterilization is liable to modify the metabolism of some minerals and the microbial flora of the digestive tract is capable of modifying this action.

A semisynthetic diet fed to axenic mice was found to prevent the establishment of a Clostridium perenne strain in their intestinal tract. This inhibitory effect did not occur when axenic mice were preinoculated with a strain of Clostridium difficile. The inhibitory effect was related to the presence in the intestinal contents of axenic mice of both dietary copper and a dipeptide, aspartic-epsilon-lysine. When C. difficile was inoculated into axenic mice, the dipeptide disappeared from the digesta, and C. perenne became established even in the presence of high concentrations of copper.

L'auteur essaie de donner une explication du mécanisme de l'implantation et de la croissance d'une stalactite tubiforme monocristalline. Il montre que son diamètre extérieur doit être compris entre deux valeurs : la plus petite équivalant au diamètre du col de rupture d'une goutte pendante, la plus grande étant indirectement liée aux dimensions maximales d'une goutte pendue à une voûte. Le diamètre intérieur de la stalactite varie comme le débit du pore qui l'alimente en eau., Andrieux C. Étude des stalactites tubiformes monocristallines. Mécanisme de leur formation et conditionnement de leurs dimensions transversales. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 88, 1, 1965. pp. 53-58.

On admettait jusqu'à ce jour, que l'allongement des édifices rupestres stalactiformes se faisait sensiblement suivant l'axe ternaire du rhomboèdre de calcite (2,3,4.). On admettait également que l'axe ternaire était orienté dans la direction de la pesanteur. La découverte de nouveaux édifices stalactitiques, monocristallins, de forme polyédrique, nous a permis de vérifier que la direction de l'axe ternaire est indépendante de la pesanteur. Nous n'avons rencontré aucun édifice stalactiforme dont l'axe A3 et l'axe d'allongement soient confondus. On montre que l'allongement des stalactites monocristallines se fait suivant des rangées privilégiées du réseau rhomboédrique, que le monocristal ne possède plus qu'un seul plan de symétrie et qu'un seul plan de clivage facile., Andrieux C. Étude cristallographique des édifices stalactitiques. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 85, 1, 1962. pp. 67-76.

L'auteur montre que des édifices monocristallins et excentriques de calcite, appelés encore « hélictites », naissent et se développent dans les grottes dont le régime hydraulique et le climat ; sont stables. Ces grottes sont, en général, situées à faible profondeur dans des terrains calcaires homogènes : les hélictites sont abondantes dans les galeries situées prés du sol pédologique. Il essaie de montrer que la croissance excentrique peut être due à la présence d'impuretés adsorbables de la calcite et inhibitrices de la croissance ; ces impuretés proviendraient du sol pédologique. L'eau traversant le canalicule est responsable de l'allongement des hélictites, alors que l'eau provenant de la paroi, et maintenue sur tout l'édifice par des forces de tensions superficielles, assure l'épaississement., Andrieux C. Morphogenèse des hélictites monocristallines. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 88, 2, 1965. pp. 163-171.

1. Groups of rats were maintained from weaning on magnesium-deficient (30 mg Mg/kg) and control (460 mg Mg/kg) diets.2. Mg deficiency for a period of more than 3 months resulted in sterility of both males and females.3. A Mg deficiency of less than 3 months caused abortions or resorptionsin uteroof foetuses in pregnant females before other physical signs appeared.4. Mg deficiency during lactation rendered the survival of young rats uncertain. The mother rat died of exhaustion if she did not devour her litter.5. The growth of surviving young rats born of Mg-deficient mothers was noticeably retarded when they were nursed by mothers receiving the Mg-deficient diet.

Many authors, both in quantum mechanics and signal theory, are concerned with a condition of positivity for the generalized Wigner functions. They give (and use) as necessary and sufficient the condition that the kernel be the characteristic function of another Wigner function. It is shown that the condition is not necessary, but only sufficient.

Des récifs à madrépores coloniaux massifs ont été découverts dans la région toulonnaise, près du petit village de Sainte-Anne d'Evenos. Ces récifs, vivants, au sénonien inférieur, présentent aujourd'hui des madrépores fossilisés en géodes étanches, dans lesquelles on trouve, entre autres, du sulfate de strontium. La présence de cette célestine pose un problème de genèse difficile à résoudre., Périnet Guy, Andrieux C. Sur la présence de strontium dans des formations récifales du sénonien toulonnais. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 81, 10-12, 1958. pp. 276-277.