Articles internationaux
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Item Explanation-aware computing of the prognosis for breast cancer supported by IK-DCBRC: Technical innovation(University of Tlemcen, 2014-10) Khelassi, AbdeldjalilBackground: Active research is being conducted to determine the prognosis for breast cancer. However, the uncertainty is a major obstacle in this domain of medical research. In that context, explanation-aware computing has the potential for providing meaningful interactions between complex medical applications and users, which would ensure a significant reduction of uncertainty and risks. This paper presents an explanation-aware agent, supported by Intensive Knowledge-Distributed Case-Based Reasoning Classifier (IK-DCBRC), to reduce the uncertainty and risks associated with the diagnosis of breast cancer. Methods: A meaningful explanation is generated by inferring from a rule-based system according to the level of abstraction and the reasoning traces. The computer-aided detection is conducted by IK-DCBRC, which is a multi- agent system that applies the case-based reasoning paradigm and a fuzzy similarity function for the automatic prognosis by the class of breast tumors, i.e. malignant or benign, from a pattern of cytological images. Results: A meaningful interaction between the physician and the computer-aided diagnosis system, IK-DCBRC, is achieved via an intelligent agent. The physician can observe the trace of reasoning, terms, justifications, and the strategy to be used to decrease the risks and doubts associated with the automatic diagnosis. The capability of the system we have developed was proven by an example in which conflicts were clarified and transparency was ensured. Conclusion: The explanation agent ensures the transparency of the automatic diagnosis of breast cancer supported by IK-DCBRC, which decreases uncertainty and risks and detects some conflicts.Item Etude des proprietes thermodynamiques , structurales et de transport du melange liquide GNL par dynamique moleculaire et application aux coumarines(University of Tlemcen, 2014-11-09) Belkacem, FouziaEtude des proprietes thermodynamiques , structurales et de transport du melange liquide GNL par dynamique moleculaire et application aux coumarinesItem Fatigue Crack Growth on Double Butt Weld with Toe Crack of Pipelines Steel(2012) Hadjoui, Féthi; Benachour, Mustapha; Benguediab, MohamedThe welded structures have a broad applicability (car industry, aeronautical, marine, pipelines, etc.). The welding being an assembled process, presents both advantages and disadvantages. A simple existing defect after welding can generate a catastrophic fracture. This work studies the fatigue crack growth of double butt weld with toe crack. Two types of pipeline material are studied with knowing API 5L grades X60 and X70 where tension form of loading is applied. In order to predict the fatigue behavior of the welded structure, a constant amplitude loading is applied where the influence of the stress ratio over the fatigue life is presentedItem Materials Sciences and Applications(University of Tlemcen, 2012-09) Hadjoui, F.; Benachour, M.; Benguediab, M.Materials Sciences and ApplicationsItem Ultra-Wide-Band Microstrip Concentric Annular Ring Antenna for Wireless Communications(University of Tlemcen, 2012-01) Azzaz Rahmani, S; Boukli Hacene2, NIn this paper, a new design technique for bandwidth enhancement of concentric microstrip annular ring slot antennas is presented. Using this technique, an Ultra-Wide-Band antenna is designed with simulated bandwidth of 111.29%.Item Effects of Mancozeb and Metribuzin on in vitro proliferative responses and oxidative stress of human and rat spleen lymphocytes stimulated by mitogens(University of Tlemcen, 2011-06-06) Medjdoub, A; Merzouk, Sa; Merzouk, H; Chiali, Fz; Narce, MPesticides have been shown to possess marked immunotropic activity. The aim of this work was to study the in vitro effects of different concentrations (1–100 lM) of Mancozeb (fungicide) and Metribuzin (herbicide),on the proliferative responses of human and rat spleen lymphocytes stimulated by concanavalin A (ConA, mitogen), the Th1- (IL-2, INFc) and Th2- (IL-4) cytokine secretion and on the intracellular oxidative status. The results showed that Mancozeb significantly reduced ConA lymphocyte proliferation in a dose-dependent manner in both humans and rats. It also decreased IL-2, INFc and IL-4 secretion with a a shift away to Th1 phenotype. Metribuzin at low concentrations (1–10 lM) resulted in activation of ConA stimulated lymphocyte proliferation and cytokine production in both human and rat spleen cells. However, at high concentrations (25–100 lM), Metribuzin induced a dose-dependent inhibition of lymphocyte proliferation and cytokines. Changes in intracellular levels of reduced Glutathione, hydroperoxides and carbonyl proteins and in the activities of catalase and SOD were observed after Mancozeb and Metribuzin exposure reflecting oxidative stress and DNA damage specially at high concentrations. In conclusion, Mancozeb and Metribuzin had significant immunomodulatory properties with oxidative stress induction at high concentrationsItem 5,6-Dihydro-2H-pyranones and 5,6-dihydro-2H-pyridones and their derivatives modulate in vitro human T lymphocyte function(University of Tlemcen, 2013) Baba Hamed, Y; Medjdoub, A; Mostefa Kara, B; Merzouk, H; Villemin, D; Narce, MThe aim of this work was to study the in vitro effects of d-lactone 1, d-lactam 3 and their enaminone derivatives 2 and 4, synthesized in our laboratory, on the proliferative responses of human lymphocytes, Th1 and Th2 cytokine secretion and intracellular redox status. Peripheral blood lymphocytes were isolated using differential centrifugation on a density gradient of Histopaque. They were cultured with mitogen concanavalin A (Con A)and with different concentrations of the compounds 1, 2, 3 and 4 (0.1–10 lM). Proliferation (MTT assay), IL-2, INFc and IL-4 (Elisa kits), oxidative markers (intracellular glutathione, hydroperoxide and carbonyl protein contents) and cytotoxic effect (micronucleus test) were determined. The compounds 1 and 2 are immunosuppressive and decrease IL-2, INFc and IL-4 secretion with a shift away from Th2 response to Th1 phenotype. The compounds 3 and 4 were immunostimulant and increased cytokine secretion with a shift away from Th1 response to Th2. The introduction of an enamine group to 1 and 3 to provide 2 and 4 seemed to attenuate their immunological properties. These immunomodulatory properties were, however, accompanied by an increase in lymphocyte intracellular oxidative stress, especially with 1 and 2 at high concentrations. In conclusion, the compounds 1, 2, 3 and 4 could be used to provide cell-mediated immune responses for novel therapies in T-cell mediated immune disordersItem Antifungal activity of the Algerian Lawsonia inermis(henna)(University of Tlemcen, 2013) Rahmoun, Nadjib; Boucherit Otmani, Zahia; Boucherit, Kebir; Benabdallah, Mohammed; Choukchou Braham, NoureddineContext: Lawsonia inermisLinn. (Lythraceae) or henna has been used since the earliest times as a medicine, preservative, and cosmetic. It has long been recommended in traditional medicine as an astringent, purgative, and abortifacient. Objective: Lawsone and six extracts of L. inermisplant, used by Algerian traditional healers to treat infectious diseases, were screened for their antifungal activity against filamentous fungi. Materials and methods: Water and five organic extracts – DMSO, ethanol, chloroform, ethyl acetate, and di-ethyl ether – of L. inermisleaves, collected in the area of Adrar (Algeria), were prepared by soaking 25 g of powdered plant in 100 mL of solvent. The extracts were screened for antifungal activity using the poisoned food technique against five filamentous fungi. Results: Results demonstrated that the best yield (8.03%) was obtained with the ethanol extract. The commercial lawsone showed potentially interesting MICs against the strains Fusarium oxysporum(12 µg/mL) and Aspergillus flavus(50 µg/mL). The ethanol extract showed the only interesting MIC (230 µg/mL of crude extract) against the strain F. oxysporumcompared with other extracts. Discussion and conclusion: These results suggest that the Algerian L. inermisplant has antifungal activity that can be related to the presence of lawsone in the leaves plant. The results can be exploited largely in research of new antifungal drugs.Item Antimicrobial Activities of the Henna Extract and Some Synthetic Naphthoquinones Derivatives(University of Tlemcen, 2013) Rahmoun, Nadjib Mohammed; Boucherit Atmani, Zahia; Benabdallah, Mohammed; Boucherit, Kebir; Villemin, Didier; Choukchou Braham, NoureddineNaphthoquinones are compounds widely distributed in the environment, both as natural products and as pharmaceutical agents. They have been the subject of much research due to their pharmacological activities. In this study, methanol extract of henna and a series of synthesized structural analogue of lawsone have been assessed for their antimicrobial activities. Methanol extract of henna and eight naphthoquinones derivatives were tested as potential antimicrobial agents against twelve bacteria and three Candida species using the agar disc diffusion and broth microdilution methods according to guidelines recommended by the Clinical and Laboratory Standards Institute. Besides 2b and 3b, methanol extract and all the synthesized compounds 1a, 2a, 1b and 1c, 2c and 3c showed weakto-strong activity against at least one tested strain. However, the compounds 1c and 1b were found to have the most effective activity against pathogenic bacteria and displayed an activity 8 to 64 fold higher than that othe structural analogue, lawsone. Their MICs ranged from 8-64 µg ml -1. Henna extract was found to have an interesting activity. Our results indicate an effective in vitro activity of 1,4-naphthoquinone derivatives and suggest the benefits of further studies for its application in antibiotherapyItem Antibacterial and antifungal activity of lawsone and novel naphthoquinone derivatives(University of Tlemcen, 2012-06) Rahmoun, Nm; Boucherit Otmani, Z; Boucherit, K; Benabdallah, M; Villemin, D; Choukchou Braham, N.Introduction. – Naphthoquinone derivatives are under investigation as potential therapeutic agents. The antibacterial and antifungal activity of lawsone and of some novel naphthoquinone derivatives was assessed in vitro. Methods. – The antimicrobial activity was determined using diffusion disk and the broth microdilution methods against seven bacteria and three Candida species, according to recommendations of the Clinical and Laboratory Standards Institute. Results. – Two compounds (P05 et P06) presented a good antibacterial effectiveness against two gram-positive bacteria. No antifungal potency was observed against the three Candida albicans strains used in the test. Conclusion. – Our results prove that the introduction of substituents on ketone function position 4 decreased the antimicrobial properties of the synthetized compoundsItem Identification and genetic diversity of Bacillus cereus strains isolated from a pasteurized milk processing line in Algeria(University of Tlemcen, 2012-09-06) Malek, F; Moussa Boudjemaa, B; Aouar Metri, A; Kihal, MBacillus cereus is a food pathogen of major concern to the dairy industry. Strains of B. cereus were isolated in 2006 and 2010 from a pasteurized milk processing line in a dairy plant in Algeria. Pasteurized milk is obtained from reconstituted and processed milk powder. This study was designed to discriminate between the isolated B. cereus strains and to predict their food poisoning potential. Strains were fingerprinted by M13-PCR, and identified at the phylogenetic group level by amplified panC gene sequence analysis. They were clustered into three distinct M13-PCR groups: one major group which included 17 strains and two minor groups which contained two and one strains, respectively. Strains originating from both the process equipment and milk powder were from the major group indicating that milk powder was the main source of initial contamination. Strains from the major and second group were affiliated to the mesophilic phylogenetic group III while the unique strain of the third group was classified into the mesophilic phylogenetic group IV. The data presented in this study showed a very low genetic diversity among B. cereus strains identified in milk powder and secondly by milk processing systems, as well as persistence in the dairy environment of specific B. cereus genotypes, across 4 years. M13-PCR typing and phylogenetic affiliation were useful for characterizing B. cereus dairy isolatesItem Microflora of biofilm on Algerian dairy processing lines: An approach to improve microbial quality of pasteurized milk(University of Tlemcen, 2012-05-09) Malek, F; Moussa Boudjemaa, B; Khaouani Yousfi, F; Kalai, A; Kihel, MBacterial contamination of pasteurized milk may originate from different sources: raw milk, process equipment surfaces and packaging materials. It is hypothesized that post-pasteurization contamination along the milk processing lines is responsible of reducing shelf life of Algerian pasteurized milk. This assumption was investigated through assessment of both the microflora of biofilms in milk pipeline systems at five dairy plants of Northwestern Algeria and the effectiveness of a quaternary ammonium based compound used for the disinfection of the plant equipment. Samples were collected before and after cleaning-in-place (CIP) systems from different segments of pasteurization lines with sterile cotton swabs. Quantitative assessment showed little reduction of the total bacteria count after CIP. On the average bacterial numbers were 5.6 × 103, 1.2 × 104, 5.1 × 104, 2.5 × 105 and 9.7 × 107 cfu/cm2, respectively, in the different units. Phenotypic identification of isolates revealed predominance of Gram-positive bacilli belonging to Bacillus and notably the Bacillus cereus group, at maximal levels of 72 and 21% respectively. The other Gram-positive microflora included Staphylococcus (30%) and Micrococcus (10%). In contrast, the incidence of the Gram-negative bacteria was relatively low. Two genera, identified as Pseudomonas (9%) and Enterobacter (6%), were found only in two dairies. Three dairies were Gram-negative bacteria-free. That should be the result of common contamination sources or highly environmental selective pressure. Further studies have to address these hypotheses. Treatment of experimental Bacillus cereus sensu lato strains biofilms with a 50, 100 and 150 ppm of quaternary ammonium disinfectant, showed a significant resistance of biofilms to this product even after long exposure time (15 min). This study emphasized the importance of aerobic spore-forming bacteria in dairy-processing equipment as they are able to built recalcitrant biofilms on the inside equipment surfaces with subsequent resistance to conventional CIP system and potential transfer to pasteurized milk. Therefore, in order to reduce the contamination levels of spore-forming bacteria and improve the quality and shelf life of the product, these dairies have, besides improvement in the hygienic status of the plant equipments, also to monitor either the pasteurization process or the contamination from raw material (that is, milk powder).Item Flank wear modeling of a tungsten carbide tip using the GMDH method in turning operation(University of Tlemcen, 2013) Kara Ali, D; Ghernaout, Mea; Galiz, S; Liazid, AIn machining area, the use of conventional ap-proach to develop a reliable method predicting tool wear with a mathematical model based on the plastic defor-mation of the work material cannot always deal to satisfac-tory results. Sometimes the conventional model gives ra-ther large prediction errors by the disturbance into the cut-ting process. This paper deals with the prediction of the tool flank wear in a turning operation using the powerful technique called Group Method of data Handling (GMDH). As a process modeling tool, the GMDH algo-rithm determines a mathematical representation between tool flank wear and the measured variables involved. The GMDH method is said useful for forming a statistical model of a complex multi-variable system using a few pro-cess data. The tool wear model obtained by applying GMDH has considerably high prediction accuracy and indicates the influence of input variables on the cutting tool life. Special care was taken to avoid the influence of the dynamic phenomenon of turning process on the obtained experimental data. The derived model reveals that tool wear and consequently tool life is a complex function ac-cording to cutting parameters: speed, feed and depth of cut.Item Toward cognitive radio resource management based on multi-agent systems for improvement of real-time application performance(University of Tlemcen, 2012) Amraoui, Asma; Benidris, Fatima Zohra; Benmammar, Badr; Krief, Francine; Bendimerad, Fethi TarikCognitive Radio (CR) is a promising technology that can alleviate the spectrum shortage problem by enabling unlicensed users equipped with CRs to coexist with incumbentusers in licensed spectrum bands while causing no interference to incumbent communications. In this paper, we propose a new approach which uses CR for improving realtimeapplication performance related to only one cognitive radio mobile terminal (CRMT). We also present a synthesis of research relating to dynamic spectrum allocationand sharing in the context of CR networks using multi-agent systems. In our future work, we will seek to improvereal-time application performance related to many CRMT.Item Effet de la combinaison de la chaux et de la pouzzolane naturelle sur la durabilité des sols argileux(University of Tlemcen, 2011-05-29) Harichane, Khelifa; Ghrici, Mohamed; Khebizi, Wiem; Missoum, HanifiItem Actinomycose de la paroi abdominale(University of Tlemcen, 2014-05-18) Loudjedi, S; Hamel, L; Bereksi, A; Taouagh, N; Bendimered, M; Bouazza, Dj; Kherbouche, ML'actinomycose est une maladie suppurative subaiguë pseudo-tumorale due à une infection par un bacille gram positif anaérobie, l’Actinomyces, germe surtout saprophyte de la sphère ORL et du tube digestif. Les atteintes abdominopelviennes classiques se font par contiguïté après une infection colique ou rectale (sigmoïdite, appendicite, par exemple). L’actinomycose pose un problème diagnostique dans la mesure ou elle se présente dans la majorité des cas sous la forme d’une masse tumorale abdominale ou pelvienne l’intérêt d’examens morphologiques tel que le scanner et les prélèvements bactériologiques qui facilitent la détection de la maladie. Dans quelques cas l’exploration chirurgicale s’impose et c’est la biopsie et l’examen anatomopatholologique extemporané qui confirme le diagnostic. Les auteurs rapportent une observation exceptionnelle pour illustrer la présentation polymorphe et la difficulté de prise en charge de cette maladie.Item Préparation et caractérisation des catalyseurs à base de ruthénium supporté sur la bentonite intercalée au titane. Application à l’époxydation du cyclohexène.(University of Tlemcen, 2014-05-14) Leshaf, AnissaCe travail est consacré à la préparation de catalyseurs à base de Ruthénium supportés sur une argile intercalée par le titane pour les tester dans les réactions d’époxydation du cyclohexène. L’argile utilisée est la Bentonite de Hammam Boughrara (carrière de Roussel), en raison des caractéristiques qu’elle présente telles que : la surface spécifique, la capacité d’échange cationique et sa disponibilité. Cette argile a été utilisée après purification suivie par des modifications chimiques (l’échange cationique). L’intercalation de titane sous forme de piliers d’oxyde dans l’espace interfoliaire de l’argile avec les différents rapports molaires Ti/g d’argile : 10,15 et 20 mmol ont été réalisés en se basant sur les méthodes décrites dans la littérature. L’imprégnation du Ruthénium a été effectuée par voie humide avec un pourcentage de 5% en poids. Les matériaux préparés ont été caractérisés par absorption atomique qui a confirmé la teneur réelle de métal déposée, par spectroscopie infrarouge qui a permis d’identifier les espèces existantes dans nos matériaux et par diffraction de rayon X qui a permis de mettre en évidence la coexistence des phase anatase et rutile pour les rapport 15 et 20 mmole de Ti/g d’argile. Les matériaux sont testés en époxydation du cyclohexène. L’argile sodée n’est pas active alors que les supports donnent des conversions élevées qui augmentent avec la teneur en titane. Les sélectivités en époxyde diminuent avec cette teneur à cause de l’apparition de la phase rutile de TiO2 qui a un effet néfaste sur l’epoxydation. En introduisant la phase métallique, les conversions baissent considérablement, probablement il y a une décomposition de l’oxydant.Item Synthesis, characterization and activity in cyclohexene epoxidation of V2O5-TiO2 anatase xerogel(University of Tlemcen, 2012-12-19) Lahcene, D; Choukchou Braham, N; Kappenstein, C; Pirault Roy, FThe system of V2O5-TiO2 catalysts with V2O5 contents from 5 to 20 wt% were prepared by the sol-gel route and calcined at 500 A degrees C. The mixed oxide series presented the crystalline structure of TiO2 anatase phase. BET analysis showed a medium surface area decreasing from 73 to 19 m(2) g(-1) when V2O5 content rose from 5 to 20 wt%. The results of pyridine adsorption followed by FT-IR indicate that the catalysts display identical surface acid densities, independently of the V2O5 content, and both Bronsted and Lewis acid sites are present on their surfaces. The V2O5 system presents an activity and selectivity during the cyclohexene oxidation reaction. The presence of V2O5 increases the catalyst efficiency and leads to a selectivity change from cyclohexenol (blank test) to epoxide, with a maximum for 15 wt% V2O5. The conversion of cyclohexene was 46 % while the selectivity to epoxide was higher (75 %).Item Thermal resistances of air in cavity walls and their effect upon the thermal insulation performance(University of Tlemcen, 2013) Bekkouche, Sma; Benouaz, T; Chreier, Mk; Hamdani, M; Yaiche, Mr; Benamrane, NThermal resistances of air in cavity walls and their effect upon the thermal insulation performance.Item Influence of building orientation on internal temperature in saharian climates, building located in ghardaia region (algeria)(2013) Bekkouche, Sidi Mohammed El Amine.; Benouaz, Tayeb.; Cherier, Mohamed Kamel.; Hamdani, Maamar.; Yaiche, Redha Mohamed.; Khanniche, Rachid.Influence of building orientation on internal temperature in saharian climates, building located in ghardaia region (algeria).