A Semantic Social Recommender System Using Ontologies Based Approach For Tunisian Tourism

Tunisia is well placed in terms of medical tourism and has highly qualified and specialized medical and surgical teams. Integrating social networks in Tunisian medical tourism recommender systems can result in much more accurate recommendations. That is to say, information, interests, and recommendations retrieved from social networks can improve the prediction accuracy. This paper aims to improve traditional recommender systems by incorporating information in social network; including user preferences and influences from social friends. Accordingly, a user interest ontology is developed to make personalized recommendations out of such information. In this paper, we present a semantic social recommender system employing a user interest ontology and a Tunisian Medical Tourism ontology. Our system can improve the quality of recommendation for Tunisian tourism domain. Finally, our social recommendation algorithm is implemented in order to be used in a Tunisia tourism Website to assist users interested in visiting Tunisia for medical purposes

Aproximación computacional al estudio de la inyectabilidad de cementos óseos y medidas ultrasónicas

Doble titulacióEste PFC presenta, en primer lugar, las bases para la formalización de simulaciones numéricas de procesos de inyección de materiales de tipo cemento como los que se utilizan en las técnicas de mínima invasión de vertebroplastia y cifoplastia. Mediante estas técnicas quirúrgicas, el cirujano inyecta un cemento óseo a través de una cánula en una vértebra fracturada por compresión debido a problemas de osteoporosis, por ejemplo. En segundo lugar, se diseña, implementa y se programa un sistema ultrasónico de medida destinado a la determinación experimental de propiedades y funciones materiales específicas de los cementos simulados aunque constituye un sistema modular y escalable para la realización de cualquier valoración no destructiva mediante ultrasonidos. Se describe en primer lugar el Estado del Arte de la aplicación clínica y de los materiales utilizados. En segundo lugar, se ha dado continuidad a trabajos y proyectos anteriores mejorando algunas realizaciones relacionadas con la simulación de la descripción del flujo mediante técnicas de Level Set. Para ello se ha documentado adecuadamente la memoria con los fundamentos básicos relacionados con el flujo de fluidos y el método de los elementos finitos que aseguren la continuidad del trabajo y se han descrito las simulaciones paso a paso de manera que faciliten el uso de la herramienta comercial que se ha hecho servir (COMSOL Multiphysics) en ulteriores proyectos. En tercer lugar se ha diseñado, construido y programado un sistema ultrasónico de medida destinado a la determinación de aquellas propiedades de los cementos utilizados que constituyen parámetros de entrada que el entorno de simulación necesita

Comparative study of the chemical composition and biological activities of the essential oils of Senecio gallicus from Tunisia.

The essential oils of flowers and remaining parts of the plant Senecio gallicus (Asteraceae), growing wild in Sfax (Tunisia), were obtained by hydrodistillation over a period of two years (2012 and 2013). Their analysis by Gas Chromatography-Mass Spectrometry (GC-MS), led to a total number of 36 components, belonging to different classes of chemical compounds. Oils compositions were characterized by the abundance of monoterpenes hydrocarbons, the major compounds present in flowers for the two years of study were  respectively the sabinene (49.45% and 28.86%), the α-pinene (9.67% and 9.1%), and the β-myrcene (9.88% and 10.97%). These compounds were also dominant in the essential oils of the plant without flowers where they represent (65.34% and 55%) for the sabinene, (4.14% and 7.3%) for α-pinene, and (6.86% and 0%) for β-myrcene. Obtained essential oils were tested for many biological activities and showed a moderate effect against the fungus Trichoderma reesei and bacteria such as Bacillus sp and Staphylococcus aureus. This study of the Senecio gallicus essential oils represents the first one in Tunisia

Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

<p>Abstract</p> <p>Background</p> <p>Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones.</p> <p>Results</p> <p>Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from <it>Rhizopus oryzae </it>was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h.</p> <p>Conclusions</p> <p>Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.</p

Evolution of endogenous enzyme activities and virgin olive oil characteristics during Chétoui and Chemlali olive ripening

The composition and biochemical characteristics of olive fruits, mainly olive enzymes system, are crucial in determining the final quality of virgin olive oil (VOO). Thus, olives endogenous olive enzyme activities were studied during Chétoui and Chemlali olive ripening. The compositional quality of the corresponding VOO was also studied. Peroxidase (POX) and β-glucosidase activities increased during olives ripening. However, polyphenoloxidase activity decreased slowly. Moreover,the POX enzyme appears to play an essential role in determining VOO total phenol amounts, as the decrease in phenol content registered during olive ripening coincided with the increase in POX activity. A positive correlation between oil antioxidant activity and the total phenol content was established for both the olive cultivars studied. With regard to pigments, chlorophyll content wasmuch higher than that of carotenoids in both Chétoui and Chemlali oils. Moreover, different trends in chlorophyll and carotenoid contents were observed, depending on the olive cultivar. Concerning volatile compounds, our results showed that the highest content of total C6, C5 LOX compounds and pentene dimers was observed at a RI of approximately 3 for both cultivars. However, C6 alcohols and total C5 compounds decreased in Chétoui and Chemlali oils, respectively, during olive ripening

Caractérisation des propriétés mécaniques et électriques des matériaux composites par méthode holographique numérique 3D et analyse diélectrique

Ce travail de thèse décrit l application de méthodes d analyse innovantes à la caractérisation des propriétésmécaniques et électriques de matériaux composites.Le Chapitre premier dresse un état de l art des fondamentaux théoriques et pré requis nécessaires à lacompréhension du manuscrit. Un regard critique permet de dégager une stratégie pour l analyse, basée d une partsur des méthodes holographiques numériques et d autre part sur des techniques de mesure diélectrique.Le Chapitre second est dédié au choix de la méthode d holographie numérique. En particulier, la configurationimage montre quelques particularités qui sont analysées en détail : le rôle du diaphragme d'ouverture du systèmed'imagerie. Nous concluons que la méthode d holographie de Fresnel présente des avantages d achromatismepour les applications avec plusieurs longueurs d onde.Le 3ème Chapitre présente deux applications de l holographie numérique au contrôle de structures compositesincorporées avec des pastilles piézoélectriques dédiées à l émission acoustique. Nous avons démontré en premiertemps, la possibilité d analyser par holographie numérique de Fresnel en temps moyenné le comportementvibratoire des poutres composites excitées harmoniquement. Dans un second temps, on a montré que les pastillesutilisées influencent le comportement mécanique des matériaux en régime statique.Le Chapitre 4 présente l analyse expérimentale et numérique des structures composites soumises à un essai decisaillement en flexion trois points rapprochés. Nous présentons les résultats obtenus pour des applications à deséchantillons lin/époxy et lin/carbone/époxy.Le 5ème Chapitre aborde l analyse des propriétés diélectriques des composites renforcés par fibres de lin. Deuxtechniques expérimentales sont mises en oeuvre : la calorimétrie différentielle à balayage (DSC) et l impédancemètre de type Novocontrol. Nous concluons que les fibres de lin seules dans le composite sont moinshydrophiles que celles incorporées avec des fibres de carbone, ce qui explique la meilleure adhérencefibres/matrice dans le premier cas.This PhD thesis describes the application of innovative analytical methods for the characterization of mechanicaland electrical properties of composite materials.The first chapter provides a state of the art of theoretical fundamentals and prerequisites needed to understandthe manuscript. A critical survey leads to a strategy for the analysis, based partly on digital holographic methodsand dielectric techniques.The second chapter is devoted to the choice of method of digital holography. In particular, this configurationshows some features that are analyzed in detail: the role of the aperture stop of the imaging system. We concludethat the Fresnel holography method has the advantage of achromatism for applications with multiplewavelengths.The third chapter presents two applications of digital holography control of composite structures with embeddedpiezoelectric patches dedicated to acoustic emission. We first demonstrate the possibility of analyzing thevibration behavior of composite beams using time averaged digital holography. Then, it was shown that thepellets used influence the mechanical behavior of materials under static conditions.Chapter 4 presents the experimental and numerical analysis of composite structures subjected to a shear test inclose three-point bending. We present the results obtained for samples with linen / flax and epoxy / carbon /epoxy.The last chapter deals with the analysis of the dielectric properties of composites reinforced with flax fibersstudied in the preceding chapter. We conclude that the flax fibers incorporated in the composite are lesshydrophilic than those incorporated with carbon fibers, which explains the improved adhesion fiber / matrix inthe first case.LE MANS-BU Sciences (721812109) / SudocSudocFranceF

In vitro study of the PLA2 inhibition and antioxidant activities of Aloe vera leaf skin extracts

<p>Abstract</p> <p>Background</p> <p>In the present work we determined the total phenolic content of <it>Aloe vera </it>leaf skin (AVLS) extracts by using various solvents (hexane, chloroform-ethanol (1/1), ethyl acetate, butanol and water). We have also evaluated the antioxidant and the anti-PLA2 properties of these extracts by measuring their inhibition potency on the human pro-inflammatory phospholipase A2 (group IIA).</p> <p>Results</p> <p>The water extract exhibits the highest inhibitory effect with an IC₅₀= 0.22 mg/ml and interestingly no effect was observed on the digestive phospholipase A2 (group IB) even at a concentration of 5 mg/ml. Antioxidant activities were also analyzed and the most active extracts were observed when using chloroform ethanol (1/1) and ethyl acetate (IC₅₀= 0.274 and 0.326 mg/ml, respectively). Analysis of the total phenolic content reveals that the water extract, with the best anti-PLA2 effect, was poor in phenolic molecules (2 mg GAE/g). This latter value has to be compared with the chloroform-ethanol and the ethyl acetate extracts (40 and 23.8 mg GAE/g, respectively), mostly responsible for the antioxidant activity.</p> <p>Conclusion</p> <p>A significant correlation was established between the total phenolic content and the antioxidant capacity but not with the anti PLA2 activity. Results from phytochemical screening suggest that the anti PLA2 molecules were probably catechin tannins compounds.</p

Synthesis of lipophilic tyrosyl esters derivatives and assessment of their antimicrobial and antileishmania activities

<p>Abstract</p> <p>Background</p> <p>Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants.</p> <p>Results</p> <p>A large series of tyrosyl esters (<b>TyC₂</b>to <b>TyC_18:1</b>) with increasing lipophilicity was synthesized in a good yield using lipase from <it>Candida antarctica </it>(Novozyme 435). Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC) methods, or their antileishmanial activity against <it>Leishmania major </it>and <it>Leishmania infantum </it>parasite species.</p> <p>Among all the tested compounds, our results showed that only <b>TyC₈</b>, <b>TyC₁₀</b>and <b>TyC₁₂</b>exhibited antibacterial and antileishmanial activities. When MIC and IC₅₀values were plotted against the acyl chain length of each tyrosyl derivative, <b>TyC₁₀</b>showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives.</p> <p>Conclusion</p> <p>These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.</p

XQuery adaptation for multimodal retrieval of multimedia documents

ABSTRACT: Recent years witness a phenomenal growth of multimedia data in various modalitie