Extrapolation of fuzzy values from incomplete data bases

This paper presents different approaches which enable a data base management system to obtain a plausible fuzzy estimate for an attribute value of an item for which the information is not explicitly stored in the data base. This can be made either by a kind of analogical reasoning from information about particular items or by means of expert rules which specify the (fuzzy) sets of possible values of the attribute under consideration, for various classes of items. Another kind of expert rules enables the system to compute an estimate from the attribute value of another item provided that, in other respects, this latter item sufficiently resembles the item, the value of which we are interested in; then these expert rules are used either for controlling the analogical reasoning process or for enlarging the scope of application of the first kind of expert rules. The different approaches are discussed in the framework of possibility theory.     

Negotiating Dialogue Games

Recently in the field of agent communication, many authors have adopted the view of interaction as a joint activity regulated by means of dialogue games. It is argued in particular that this approach should increase the flexibility of dialogues by allowing a variety of game compositions. In this research note, we present a framework suited to this feature. A preliminary attempt to capture the negotiation phase (which allows agents to agree upon the dialogue game currently regulating their conversation) is discussed.     

Influence of carbonaceous electrodes on capacitance and breakdown voltage for hybrid capacitor

This paper presents a new type of capacitor and deals with a hybrid approach where the advantages of two systems, dielectric capacitors and the ultracapacitor are combined. The objective is to increase the capacitance and the energy storage capability, while or at least preserving or decreasing the volume of the passive components. In this aim, the surface area and structural properties of ultracapacitor electrodes and the high dielectric strength of a polymer material are associated. The surface roughness of the carbonbased electrodes, namely (activated carbon—AC, and carbon nanotubes—CNTs), has a good impact on the capacitance. However, the surface roughness also depends on the composition of carbonaceous materials and so does the capacitance. Moreover, the choice of the dielectric material is the key parameter. The better the impregnation of the roughness is, the better is the increase of the capacitance.Since the final objective is to improve the electrical energy stored by the capacitor, the effect of surface roughness on the breakdown voltage is also evaluated.     

Transmission electron microscopy for elucidating the impact of silver-based treatments (ionic silver versus nanosilver-containing coating) on the model yeast Saccharomyces cerevisiae

After exposure to ionic silver or nanosilver-containing plasma coating, the same visual aspect of scanning transmission electron microscopy (STEM) images was observed for the model yeast Saccharomyces cerevisiae. The main common feature was the presence of electron-dense nodules all over the cell. However, high resolution TEM (HRTEM), STEM, energy dispersive x-ray microanalysis spectroscopy (EDS) and electron microdiffraction revealed some striking differences. Regarding ionic silver exposure, the formation of electron-dense nodules was related to the Ag(+) reactivity towards sulfur-containing compounds to form clusters with Ag(2)S-like structures, together with the production of a few silver nanocrystals, mainly at the cell wall periphery. For nanosilver-based treatment, some sulfur-containing silver clusters preferentially located at the cell wall periphery were detected, together with nodules composed of silver, sulfur and phosphorus all over the cell. In both silver-based treatments, nitrogen and silver signals overlapped, confirming the affinity of silver entities for proteinaceous compounds. Moreover, in the case of nanosilver, interactions of silver with phosphorus-containing subcellular structures were indicated.     

Valeur d'un test in vitro d'incorporation de glucose marque pour l'estimation de l'activité antiseborrheique

Deux methodes d'estimation de l'activité antiséborrhéique, l'une in vitro , l'autre in vivo , ont été comparées en étudiant l'action de deux produits différents: le metbufen et la N-sébaçoylméthionine. Le test in vitro d'incorporation de glucose marqué est pratiqué sur la glande préputiale de rat isolée. In vivo , sur la peau de rat castré et supplémenté par l'énanthate de testortérone, l'effet de traitement topique est suivi par l'étude histologique des glandes sébacées.
Les résultats obtenus avec les deux produits essayés présentent un parallélisme permettant de conclure à la validité du test in vitro dans le screening de molécules à activité antiséborrhéique.
An in vitro test for the evaluation of antiseborrheic activity     

In vitro screening of probiotics and synbiotics according to anti-inflammatory and anti-proliferative effects

There is emerging evidence of the efficiency of probiotic, prebiotic and synbiotic treatments in inflammatory bowel diseases (IBDs) and one of their long-term complications, colorectal cancer (CRC). In this study, various strains of probiotic lactic acid bacteria, prebiotic glucooligosaccharides (GOS) or a synbiotic combination of the two were screened for anti-inflammatory and anti-proliferative effects in different in vitro models in the context of such diseases. To mimic IBD response to Gram negative bacteria, HT-29 cells were sensitised to inflammatory response to lipopolysaccharide (LPS) by IFNγ which increased expression of TLR4, the LPS biosensor, and were then treated by probiotics, prebiotics and synbiotics. Secreted IL-8 and activated NF-κB were monitored as inflammation biomarkers. A selection of active strains were then subjected to a second inflammatory cell culture model consisting of inflammatory activated transgenic Caco-2 cells transfected by a reporter gene under the control of NF-κB inducible promoter. Quantification of reporter gene expression allowed us to demonstrate some probiotic inhibitory properties or to confirm such characteristics in two different models. Proliferation of cancerous HT-29 cells was monitored by XTT assay. Only three probiotic strains induced a proliferation decrease, but with a lack of reproducibility. Binary or ternary probiotic associations, complemented or not by prebiotic GOS, significantly decreased proliferation, especially with a synbiotic association of Bifidobacterium breve, Lactococcus lactis and oligoalternan, a GOS. This combination was selected for the following experiments. We showed the involvement of both bacterial and carbohydrate compounds of this synbiotic in the observed effect by dose range tests. We demonstrated that this decrease in proliferation may be due to an induction of a differentiated phenotype, as shown by the up-regulation of intestinal alkaline phosphatase, a biomarker of differentiation, monitored by real-time RT-PCR in HT-29 cells treated by the selected synbiotics. Thus, this study demonstrates the ability of probiotics to exert anti-inflammatory effects and shows some anti-proliferative characteristics for a specific synbiotics. These products should be further evaluated in animal models to confirm the in vitro results.     

Application d'une méthodologie expérimentale à l'étude du diagramme ternaire d'un gel

Nous avons montré sur l'exemple d'un gel, mélange de trois constituants (C12–C15 Alcohols Benzoate, Cyclomethicone et Ethylene Vinyl Acetate Copolymer) qu'il est possible d'optimiser une formulation en un nombre preécis d'essais en faisant appel à une stratégic expérimentale optimale. Le gel avait déjàétéétudié par Chang,¹ mais par approches successives.
Nous avons utlisé les matrices d'expériences développées dans le cas des mélanges par Scheffe sous le nom de 'reseaux-simplex'. Prévoyant des intéractions de 2éme ordre entre les constituants nous avons retenu le modéle appelé'cubique réduit'. Cette approche permet l'exploration systémique de tout le domaine.
Les réponses étudiées sont la compatibilité (gel homogène ou non), la consistance, la blancheur et le coût. Le meilleur gel étant celui qui se rapproche le plus de la vaseline.
A partir des résultats, nous avons tracé des courbes d'isoréponse en blancheur, consistance et coût. La superposition des diagrammes conduit à la détermination d'une zone où les réponses sont optimales.
En ajoutant la réponse supplémentaire: 'facilité d'étalement sur la peau'on arrive au meilleur gel avec un nombre réduit d'essais.
La même méthode s'appliquerait à des mélanges de plus de trois constituants.
Study of a ternary diagram gel according to a methodology of experimental research     

Immobilised yeast grape must deacidification in a recycle fixed bed reactor

Maloalcoholic fermentation (MAF) of grape must by Schizosaccharomyces pombe immobilised in calcium‐alginate double‐layer beads (ProMalic^®) was studied in Erlenmeyer flasks and in a total recycle fixed‐bed reactor operating in batch mode. The reaction is pseudo‐first order with respect to l ‐malic acid and under similar conditions deacidification is faster in the recycle reactor. This was attributed to mass transfer limitations which were confirmed in the recycle reactor by studying the influence of yeast load on the rate of MAF. Mass transfer limitations are also responsible for the lower activation energy of fermentation with the immobilised yeast (67 ± 9 kJ mol^?1) in comparison with the free cells (126 ± 19 kJ mol^?1). Alcoholic fermentation and MAF were performed simultaneously, both in the recycle reactor and in the industrial trials, confirming the efficacy of immobilised S. pombe to reduce grape must acidity without interfering with the main fermentation. Altogether, the present results are useful for the scale‐up of a recycle reactor to process large volumes of grape must.