Search results for: Ouassila Labbani-Narsis

Authors: Ouassila Labbani-Narsis, Christophe Nicolle

Abstract:

Building formal ontologies remains a complex process for companies. In the literature, this process is based on the technical knowledge and expertise of domain experts, without further details on the used methodologies. Possible problems of disagreements between experts, expression of tacit knowledge related to high level know-how rarely verbalized, qualification of results by using cases, or simply adhesion of the group of experts, remain currently unsolved. This paper proposes a methodological approach based on knowledge elicitation for the conception of formal, consensual, and shared ontologies. The proposed approach is experimentally tested on industrial collaboration projects in the field of manufacturing (associating knowledge sources from multinational companies) and in the field of viticulture (associating explicit knowledge and implicit knowledge acquired through observation).

Keywords: collaborative ontology engineering, knowledge elicitation, knowledge engineering, knowledge management

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Authors: Chahinez Ait Si Said, Ouassila Touafek, Mohamed Reda Zahi, Smain Sabour, ‎Mohamed El Hattab ‎

Abstract:

Oil mill wastewater (OMW) is a major effluent of the olive industry resulting from olive ‎oil extraction which is a great source for the development of new drugs. The present ‎study aimed to evaluate the antimicrobial activity of seven different fractions separated ‎from OMW extract. The sample was recovered from an oil mill in the Blida region ‎‎(Algeria). A crude ethyl acetate extract was prepared from OMW according to a well-‎established protocol; the yield of the extract obtained was 4%. From the extract, ‎different fractions were prepared by fractionating the total extract with an open column ‎chromatography. The obtained fractions were submitted to antimicrobial activity ‎screening in a comparative purpose. All the fractions obtained show great antimicrobial ‎potential. ‎Phytochemical study of the different fractions was assessed by evaluating the total ‎phenolic compounds for all fractions studied as the main compounds found in OMW ‎were phenols like hydroxytyrosol, tyrosol, phenolic acids like caffeic, quinic and ferulic ‎acids which show great therapeutic activities. ‎

Keywords: olive mill wastewater, fractionation, total phenolic compound, antimicrobial activity

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Authors: Ouassila Bekkal Brikci Benhabib, Zahia Boucherit Otmani, Kebir Boucherit, A. Seghir

Abstract:

The establishment of intravenous catheters in hospitalized patient is an act common in many clinical situations. These therapeutic tools, from their insertion in the body, represent gateways including fungal germs prone. The latter can generate the growth of biofilms, which can be the cause of fungal infection. Faced with this problem, we conducted a study at the University Hospital of Tlemcen in the neurosurgery unit and aims to isolate and identify Candida yeasts from intravenous catheters. Then test their ability to form biofilms. Materials and methods: 256 patient hospitalized in surgery of the hospital in west Algeria were submitted to this study. All samples were taken from peripheral venous catheters implanted for 72 hours or more days. A total of 31 isolates of Candida species were isolated. MIC and SMIC are determined at 80% inhibition by the test XTT tetrazolium measured at 490 nm. The final concentrations of antifungal agent being between 0.03 and 16 mg / ml for amphotericin B and from 0.015 to 8 mg / mL caspofungin. Results: 31 Candida species isolates from catheters including 14 Candida albicans and 17 Candida non albicans . 21 strains of all the isolates were able to form biofilms. In their form of Planktonic cells, all isolates are 100% susceptible to antifungal agents tested. However, in their state of biofilms, more isolates have become tolerant to the tested antifungals. Conclusion: Candida yeasts isolated from intravascular catheters are considered an important virulence factor in the pathogenesis of infections. Their involvement in catheter-related infections can be disastrous for their potential to generate biofilms. They survive high concentrations of antifungal where treatment failure. Pending the development of a therapeutic approach antibiofilm related to catheters, their mastery is going through: -The risk of infection prevention based on the training and awareness of medical staff, -Strict hygiene and maximum asepsis, and -The choice of material limiting microbial colonization.

Keywords: candida, biofilm, hospital, infection, amphotericin B, caspofungin

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