44 research outputs found

    Interplaying Cassandra NoSQL Consistency and Performance: A Benchmarking Approach

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    This experience report analyses performance of the Cassandra NoSQL database and studies the fundamental trade-off between data consistency and delays in distributed data storages. The primary focus is on investigating the interplay between the Cassandra performance (response time) and its consistency settings. The paper reports the results of the read and write performance benchmarking for a replicated Cassandra cluster, deployed in the Amazon EC2 Cloud. We present quantitative results showing how different consistency settings affect the Cassandra performance under different workloads. One of our main findings is that it is possible to minimize Cassandra delays and still guarantee the strong data consistency by optimal coordination of consistency settings for both read and write requests. Our experiments show that (i) strong consistency costs up to 25% of performance and (ii) the best setting for strong consistency depends on the ratio of read and write operations. Finally, we generalize our experience by proposing a benchmarking-based methodology for run-time optimization of consistency settings to achieve the maximum Cassandra performance and still guarantee the strong data consistency under mixed workloads

    In vitro antimicrobial activity of Pistacia lentiscus L. edible oil and phenolic extract.

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    International audiencePistacia lentiscus L. is known in some Tunisian forest area by its fixed oil used in traditional medicine as an antiseptic product. This investigation is the first to study the antimicrobial activity of P.lentiscus edible oil and its phenolic extract. Oil was extracted from fruits harvested from six provenances located in Tunisia. The antimicrobial activity was tested using disc diffusion assay and the broth dilution method. Kbouch and Sidi Zid oils were most efficient (p < 0.003) against, respectively, Staphylococcus aureus and Aspergillus niger with an inhibition zone of 9.33 mm. The phenolic extract had the largest spectrum of sensitive microorganisms. The minimum inhibitory concentration and minimum bactericidal concentration results showed that all strains were inhibited by both oil and extract

    Effect of growing area on tocopherols, carotenoids and fatty acid composition of Pistacia lentiscus edible oil

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    International audienceIn this investigation, we aim to study, for the first time, the effect of the growing area on tocopherols, carotenoids and fatty acid content of Pistacia lentiscus fixed oil. Fruits were harvested from eight different sites located in the north and the centre of Tunisia. Tocopherols, carotenoids and fatty acid content of the fixed oils were determined. The highest carotenoid content was exhibited by Feija oil (10.57 mg/kg of oil). Oueslatia and Tabarka oils displayed the highest alpha-tocopherol content (96.79 and 92.79 mg/kg of oil, respectively). Three major fatty acids were determined: oleic, palmitic and linoleic acids. Oleic acid was the main fatty acid presenting more than 50% of the total fatty acid content. Kebouche oil presented the highest oleic acid content (55.66%). All these results highlight the richness of carotenoids, tocopherols and unsaturated fatty acids in P. lentiscus seed oil and underscore the nutritional value of this natural product

    A unilocular thymic cyst associated with true thymic hyperplasia: a challenging diagnosis especially in a child

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    Mona Mlika,1,2 Walid Gattoufi,1,2 Hazem Zribi,2 Emna Braham,1,2 Adel Marghli,2 Faouzi El Mezni1,21Department of Pathology, Abderrahman Mami Hospital, Tunis, Tunisia; 2Research Unit UR12SP16, Universit&eacute; Tunis El Manar, Facult&eacute; de M&eacute;decine de Tunis, Tunis El Manar, TunisiaAbstract: We report a new case of a mediastinal mass in a 19-year-old patient corresponding microscopically to an association of unilocular thymic cyst and true thymic hyperplasia. Our aim is to highlight the absence of specificity of clinical and radiological findings and the necessity of a thorough sampling of the tumor in order to establish the diagnosis.Keywords: true thymic hyperplasia, thymic cyst, microscopy, surger
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