A programmable architecture for the provision of hybrid services

The success of new service provision platforms will largely depend on their ability to blend with existing technologies. The advent of Internet telephony, although impressive, is unlikely to make telephone customers suddenly turn in favor of computers. Rather, customers display increasing interest in services that span multiple networks (especially Internet Protocol-based networks and the telephone and cellular networks) and open new vistas. We refer to these services as hybrid services and propose an architecture for their provision. This architecture allows for programming the service platform elements (i.e., network nodes, gateways, control servers, and terminals) in order to include new service logics. We identify components that can be assembled to build these logics by considering a service as a composition of features such as address translation, security, call control, connectivity, charging and user interaction. Generic service components are derived from the modeling of these features. We assure that our proposal can be implemented even in existing systems in return for slight changes: These systems are required to generate an event when a special service is encountered. The treatment of this event is handled by an object at a Java Service Layer. Java has been chosen for its platform-neutrality feature and its embedded security mechanisms. Using our architecture, we design a hybrid closed user group service

Tests de contrôle de qualité des caractéristiques mécaniques pour les tuiles, large format en micro-béton : étude et réalisation

Le travail intitulé « Tests de contrôle de qualité des caractéristiques mécaniques pour les tuiles, large format en micro-béton : étude et réalisation » a pour objet principal de proposer une technologie d’amélioration des tests de contrôle de qualité des caractéristiques mécaniques suivantes : résistance à la flexion trois (3) points et quatre (4) points, résistance aux chocs et résistance à la traction du talon. A cet effet, une étude conceptuelle basée sur la 3ème loi de NEWTON : « principe de l’action et de la réaction » et le calcul de structures par la méthode des éléments finis a permis de modéliser, d’analyser et de dimensionner un nouveau dispositif qui respecte avec une certaine rigueur les recommandations et les exigences des documents normatifs [4]. Ce nouveau dispositif qui regroupe les différents tests de contrôle des caractéristiques mécaniques mentionnées ci-dessus a été réalisé et validé. Lors de la validation, nous avons comparé les résultats issus des simulations numériques par éléments finis et des essais réels. Mots-clés : micro-béton, tuile, dispositifs des tests, contrôle de qualité, caractéristiques mécaniques, action et  réaction, éléments finis et large format.Tests of quality control of the mechanical characteristics for tiles, the wide size in micro-concrete: study and realizationThe work entitled "tests of quality control of the mechanical characteristics for tiles, the wide size in microconcrete: study and realization " has for main object to propose a technology of improvement of the tests of quality control of the following mechanical characteristics: fold resistance three (3) points and four (4) points, shock resistance and traction resistance of the heel. For that purpose, an abstract study based on the NEWTON's 3rd law: " Principle of the action and the reaction " and the calculation of structures by the method of the finished elements allowed to model, to analyze and to size a new device which respects with a certain rigor the recommendations and the requirements of the normative documents [4]. This new device which groups together the various tests of control of the mechanical characteristics mentioned above was realized and validated. During the validation, we compared the results stemming from numeric simulations by finished elements and from real tries. Keywords : micro-concrete, tile, devices of the tests, the quality control, the characteristics mechanics, action and reaction, finished elements and wide size

Étude des caractéristiques physico-mécaniques des tuiles en micro-béton fabriquées localement à base de la gomme arabique

La présente étude a pour objet la validation de l’utilisation d’un liant végétal naturel comme matrice dans l’élaboration des matériaux de construction. La gomme arabique, également connue sous le nom de gomme Sénégal, en substitution du ciment a été utilisée pour la fabrication des tuiles en micro-béton. Les méthodes expérimentales des essais dites de « mise au point » et des « essais erreurs » ont servi pour déterminer les rapports optimaux de l’eau sur la gomme arabique (E/G) et de la solution de la gomme arabique sur le sable (SG/S). Avec ces rapports, les essais de contrôle ont été effectués sur les tuiles romanes d’expérimentations de dimensions 500x250x10 mm3. Les résultats de ces essais nous montrent que ces tuiles sont belles et biens résistantes et leurs aspects physiques ne posent aucun problème. En outre, l’analyse statique et dynamique modale par simulation numérique confirme ces résultats. Toutefois, pendant leur maturation, les tuiles à base de la gomme arabique doivent être placées dans un séchoir ou au soleil jusqu’à ce que la colle(mélange de l’eau et de la gomme) sèche complètement. Par cette étude, nous pouvons désormais envisager de couvrir nos ouvrages avec ces types de tuiles. Enfin, comme ces tuiles seront exposées aux intempéries, nous entrevoyons en perspective de réaliser une étude complémentaire pour en savoir plus sur leur vieillissement sous l'action de l'humidité et de la chaleur. Mots-clés : liant, matrice, gomme, ciment, tuile, analyse, statique, dynamique, modale, simulation, maturation, séchoir. Study of the characteristics physico-mecaniques of tiles in micro-concrete made locally with the gum arabic The present study has for object the validation of the use of a plant sociable disposition natural as matrix in the elaboration of building materials. The gum arabic, also known under the name of gum Senegal, in substitution of the cement was used for the manufacturing of tiles in micro-concrete. The experimental methods of the tries said about "clarification" and about " tries errors " served to determine the optimal relationships of the water on the gum arabic ( E/G) and the solution of the gum arabic on the sand (SG/). With these relationships, the tries of control were made on the Romanic tiles of experiments of dimensions 500x250x10 mm3. The results of these tries show us that these tiles are beautiful and good resistant and their physical aspects raise no problem. Besides, the static and modal dynamic analysis by digital simulation confirms these results. However, during their maturation, tiles with the gum arabic must be placed in a hairdryer or in the sun until the glue (mixture of the water and the gum) dries completely. By this study, we can intend from now on to cover our works with these types of tiles. Finally, as these tiles will be exposed to the bad weather, we envisage in prospect to realize a follow-up study to know more about their ageing under the effect of the humidity and of the heat.Keywords : binder, matrix, gum, cement, tile, analysis, statics, dynamic, modal, simulation, maturation, hairdryer

Extensions to an Authentication Technique Proposed for the Global Mobility Network

We present three attacks against the authentication protocol that has been proposed for the so called global mobility network in \cite{kn:Suz97}. We show that the attacks are feasible and propose corrections that make the protocol more robust and resistant against the presented attacks. Our aim is to highlight some basic design principles for cryptographic protocols, the adherence to which would have prevented these attacks

Variation diurne de la composition chimique et influence sur les propriétés antimicrobiennes de l’huile essentielle de Ocimum canum Sims cultivé au Bénin

L’huile essentielle de Ocimum canum Sims (Lamiaceae) obtenue par hydrodiffusion à différents moments de la journée a été analysée par GC/FID et GC/SM puis testée sur différentes bactéries par la microtechnique de dilution. Le rendement et la composition chimique de l’huile varient selon le temps et l’ensoleillement. Abondant le matin à 7 heures (1,71±0,01%), le rendement décroît progressivement avec l’augmentation des rayons solaires, jusqu’à son minimum à 13 heures (1,35±0,01%) quand le soleil est au zénith, avant de croître à nouveau à sa valeur la plus élevée (1,78±0,02% à 19 h) au couché du soleil. Plus de 54 composés représentant près de 98% des hydrodiffusats, ont été identifiés dans les différents échantillons. Les principaux sont : α-thujène (5,56 à 7,85%), β-myrcene (2 à 6,94%), δ-3-carène (3,07 à 4,84%), p-cymène (14,61 à 22,8%), g-terpinène (6,05 à 10,7%), carvacrol (7,94 à 30,8%), β-caryophyllène (0,15 à 18,86%) et β- sélinène (2,74 à 14,41%). Les taux de certains constituants comme β-caryophyllène et β-sélinène croissent avec l’ensoleillement contrairement à ceux du carvacrol, p-cymène. Cette variation diurne perturbe la synergie d’action des constituants de l’huile qui présentent une forte activité inhibitrice (0,38 à 7,19 mg/ml) sur Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25923, Acinetobacter baumannii ATCC 19609 et Staphylococcus aureus résistante 1199B NorA. Les huiles obtenues à 7 heures et 19 heures sont les plus efficaces à faible concentration (0,38 à 2,88 mg/ml). Pour la première fois, l'interaction est démontrée entre variation diurne de la composition chimique et propriétés antimicrobiennes de l'huile essentielle de Ocimum canum Sims du Bénin.Keywords: Ocimum americanum, composés volatils, Chémotype à carvacrol Variation diurne-Activité antibactérienn

HIGH PERFORMANCE LIQUID CHROMATOGRAPHY QUANTIFICATION OF OLEANOLIC ACID IN LAUNAEA TARAXACIFOLIA AND LARVICIDAL ACTIVITY AGAINST ANOPHELES GAMBIAE

Objective: One of the measures used to prevent malaria is the management of breeding sites. For preventive and ecologically profitable control, the use of bio-larvicides made from active plant extracts would be an asset for the control of malaria vectors, in particular Anopheles gambiae. Advances in pharmacognosy have revealed the benefits of several phytochemicals with very rich and varied therapeutic effects. Among the latter, oleanolic acid (OA) is quite remarkable because of its various and multiple properties, much of which is demonstrated with the leaves of Launaea taraxacifolia. Methods: After a liquid-liquid fractionation with different organic solvents of the hydro-methanolic extract of Launaea taraxacifolia, we obtained three fractions named Fhex (hexane fraction), FDCM (dichloromethane fraction) and FHM (hydro-methanolic fraction) which were tested on 3rd instar Anopheles gambiae larvae. Results: Fhex proved to be the most active with LC50 of 120.11 ppm and 69.50 ppm respectively in 24 and 48 hours of contact. We then developed a new method of Ultra-Violet High Performance Liquid Chromatography (HPLC / UV) method and determined the quantity of oleanolic acid in the Fhex and FDCM fractions to be respectively 0.46% and 0.23% . Conclusion: Launaea taraxacifolia has a larvicidal potential due to the presence of oleanolic acid whose inhibitory effect against Anopheles gambiae larvae

The Effect of Spirulina platensis versus Soybean on Insulin Resistance in HIV-Infected Patients: A Randomized Pilot Study

HIV-infected patients develop abnormalities of glucose metabolism due to the virus and antiretroviral drugs. Spirulina and soybean are nutritional supplements that are cheap, accessible in our community and affect glucose metabolism. We carried out a randomized study to assess the effect of Spirulina platensis versus soybean as a food supplement on HIV/HAART-associated insulin resistance (IR) in 33 insulin-resistant HIV-infected patients. The study lasted for two months at the National Obesity Centre of Cameroon. Insulin resistance was measured using the short insulin tolerance test. Physical activity and diet did not change over the study duration. On-treatment analysis was used to analyze data. The Mann-Whitney U test, the Students T test and the Chi square test were used as appropriate. Curve gradients were analyzed using ANCOVA. Seventeen subjects were randomized to spirulina and 16 to soybean. Each received 19 g of supplement daily. The follow up rate was 65% vs. 100% for spirulina and soybean groups, respectively, and both groups were comparable at baseline. After eight weeks, insulin sensitivity (IS) increased by 224.7% vs. 60% in the spirulina and soybean groups respectively (p < 0.001). One hundred per cent vs. 69% of subjects on spirulina versus soybean, respectively, improved their IS (p = 0.049) with a 1.45 (1.05–2.02) chance of improving insulin sensitivity on spirulina. This pilot study suggests that insulin sensitivity in HIV patients improves more when spirulina rather than soybean is used as a nutritional supplement. Trial registration: ClinicalTrials.gov identifier NCT01141777

Farmers' perception of climate change and climate-smart agriculture in northern Benin, west Africa

Climate-Smart Agriculture (CSA) is an approach that identifies actions needed to transform and reorganize agricultural systems to effectively support agricultural development and ensure food security in the face of climate change. In this study, we assessed farmers’ perception of climate change, available CSA practices (CSAP) and the determinants of CSAP adoption in northern Benin. A list of CSAP was generated from a workshop with different stakeholders. Face-to-face interviews were then carried out with 368 farmers selected based on stratified random sampling in the study area. Binomial generalized mixed-effect models were run to analyze the relation between socio-demographic characteristics and the use of CSAP. CSAP were evaluated using a three-point Likert scale and the frequency of agreement with the statement that the selected practices meet the pillars of CSA. More than 60% of farmers had heard about climate change, and more than 80% had observed changes in temperature, rainfall amounts and distribution. Thirty-one CSAP were identified in the area, and only 11 were known by more than 50% of farmers. Out of the 12 selected CSAP for the assessment of adoption and evaluation, seven (7) were used by more than 50% of those who knew them. Farmers agreed with the statements that the evaluated practices improved farm productivity and adaptation to climate change but did not mitigate climate change. Ethnic group and education level were the two major factors that significantly determined the use of the evaluated CSAP