On the Design of Clean-Slate Network Control and Management Plane

We provide a design of clean-slate control and management plane for data networks using the abstraction of 4D architecture, utilizing and extending 4D’s concept of a logically centralized Decision plane that is responsible for managing network-wide resources. In this paper, a scalable protocol and a dynamically adaptable algorithm for assigning Data plane devices to a physically distributed Decision plane are investigated, that enable a network to operate with minimal configuration and human intervention while providing optimal convergence and robustness against failures. Our work is especially relevant in the context of ISPs and large geographically dispersed enterprise networks. We also provide an extensive evaluation of our algorithm using real-world and artificially generated ISP topologies along with an experimental evaluation using ns-2 simulator

Coopetition spectrum trading in cognitive radio networks

Spectrum trading is a promising method to improve spectrum usage efficiency. Several issues must be addressed, however, to enable spectrum trading that goes beyond conservative trading idle bands and achieve cooperation between primary and secondary users. In this paper, we argue that spectrum holes should be explicitly endogenous and negotiated by spectrum trading participants. To this end, we proposed an a Vickery auction based, coopetive framework to foster cooperation, while allowing competition for spectrum sharing. Incentive schemes and penalty for revocable spectrum are proposed to increase the spectrum access opportunities for SUs while protecting PUs spectrum value. A simultation study shows that the proposed framework outperforms conservative trading approaches, in a variety of scenarios with different levels of cooperation and bidding strategies. © 2013 IEEE

Investigation phytochimique et biologique d'espèces du genre Ferula. Synthèse d'analogues structuraux et étude de la relation structure-activité

Souhaitant valoriser des plantes médicinales non étudiées et découvrir de nouvelles substances naturelles biologiquement et pharmacologiquement actives, nous avons étudié quelques extraits volatils et non volatils des plantes Ferula tunetana L. et F. lutea (Poire) Maire. (Apiaceae). L'étude de la composition chimique des huiles essentielles des fleurs de F. lutea et des feuilles, graines, tiges et racines de la plante F. tunetana nous a permis d'identifier la majorité des constituants par la CPG, la CPG/SM et la RMN 13C. Les investigations phytochimiques entreprises sur deux extraits des fleurs de F. lutea, par les techniques chromatographiques liquides et préparatives sur colonne à pression atmosphérique (CC), chromatographie à haute pression (flash chromatographie) et CCM préparatives, nous ont permis d'isoler six produits de l'extrait butanolique. Deux nouveaux composés non cités dans la littérature (E)-5-ethylidenefuran-2(5H)-one-5-O-ß-D-glucopyranoside (P1) et l'acide 4-hydroxy-3, méthyl butanoique (P5) et trois produits isolés pour la première fois de cette plante : verbenone-5-O-ß-D-glucopyranoside (P2), caféate de méthyle (P3) et l'acide chlorogénique (P4). Nous avons pu aussi isoler de l'extrait à l'acétate d'éthyle des fleurs de F. lutea sept produits isolé pour la première fois de cette plante, 3, 5-O-dicaféoylquinate de méthyle (P6), l'acide 3,5-O-dicaféoylquinique (P7), narcissin (P8), (-)-Z-deltoine (P9), (-)-marmésine (P10), Isoimperatorine (P11) et 2,3,6 triméthyl benzaldéhyde (P12). Les structures de ces composés ont été élucidées à l'aide des méthodes spectroscopiques : spectrométrie de masse (DCI-SM, ES-SM), spectroscopie de RMN 1D et 2D (1H, 13C, HSQC, HMBC, COSY et NOESY) et le Rayon X pour le composé (P5). Nous avons isolé une bonne quantité de deltoine (P10) ce qui nous a permis d'effectuer des hémisynthèses d'une série 1,3 dipolaire pour accéder à de nouveaux isoxazolines (2a,a'-2g,g') et aziridines (3a,a'-3e,e') D'autre part, connaissant les propriétés biologiques des phénoliques, par exemple les flavonoïdes, nous avons synthétisé de nouveaux dérivés de type flavonole Flav1-Flav26. Les activités biologiques des huiles essentielles, extraits organiques, produits purs et les produits synthétisés ont été évaluées à l'aide de tests in vitro : activités microbiologique (contre diverses souches bactériennes et fongiques), antioxydante (envers les radicaux DPPH, ABTS), inhibitrice de 5-lipoxygénase et cytotoxique (sur une lignée cancéreuses coliques humaines HCT 116 et deux lignées ovariennes IGROV-1 et OVCAR-3)Wishing to enhance not studied medicinal plants and discover new biologically and pharmacologically active natural products, we studied some volatile and non-volatile extracts of plants: Ferula tunetana and F. lutea (Apiaceae). The chemical composition of the flower oil from F. lutea and the leaves, seeds, stems and roots of F. tunetana, obtained by hydrodistillation, were analyzed by combination of GC/FID, GC/MS and 13C-NMR spectroscopy. The phytochemical investigations of flowers of F. lutea undertaken on these two extracts using preparative liquid chromatographic column at atmospheric pressure (CC), high pressure chromatography (flash chromatography) and preparative TLC allowed us to isolate two new compounds from n-butanol (E)-5-ethylidenefuran-2(5H)-one-5-O-ß-D-glucopyranoside (P1), 4-hydroxy-3-methyl-but-2-enoic acid (P5 ), and three known compounds Verbenone-5-O-ß-D-glucopyranoside (P2 ), methyl caffeate (P3 ) and chlorogenic acid (P4 ). We were also isolated seven compounds isolated from the first time from ethyl acetate of flowers of F. lutea: methyle 3, 5-O-dicaffeoylquinate (P6), 3,5-O-dicafeoylquinic acid (P7), Narcissin (P8), (-)-Z-Deltoin (P9), (-)-marmesin (P10), Isoimperatorin (P11), 2,3,6 trimethyl benzaldehyde (P12). The pure compounds have had their structure elucidated using sepctroscopics methods: mass spectrometry (DCI-SM and ESI-MS) and NMR spectroscopy, 1D and 2D experiments (1H, 13C, HSQC, HMBC, COSY and NOESY) and diffraction of X-ray for compound (P5) We isolated a good quantity of Deltoin (10) which allowed us to perform a series hémisynthesis of 1,3-dipolar to access new isoxazolines and aziridines derivatives. Within the framework of synthesizing similar natural substances, we prepared a series of novel flavonol derivatives. The biological activities of essential oils, organic extracts, pure compounds and synthesized products were evaluated by in vitro bioassays: microbiological (against various strains of bacteria and fungi), antioxidant (towards radical DPPH and ABTS), 5-lipoxygenase inhibitory and cytotoxic (on one human colon cancer cell lines HCT 116 and two ovary cells lines IGROV-1 and OVCAR-3) activitie

Coopetive spectrum trading - Creating endogenous spectrum holes

Dynamic spectrum access has been proposed to address the spectrum scarcity. Based on this access mode, secondary users are allowed to opportunistically operate when primary users are absent. Secondary Users are, however, required to relinquish the spectrum upon return of the incumbent spectrum holder. Although it improves spectrum utility, opportunistic spectrum access limits secondary users' access to exogenous spectrum holes vacated by primary users. We argue that spectrum holes should be endogenous, enabled by incentives to incumbent users to increase spectrum availability, while mitigating risk. To this end, we take a different perspective on dynamic spectrum sharing and propose a coopetive framework, whereby primary and secondary users engage in a cooperative, yet competitive, auction-driven spectrum sharing to enhance spectrum usage. In this framework, the primary users'spectrum is organized in three bands, namely exclusive usage, usage right and management right bands. Based on this structure, spectrum is traded as financial options to increase trading flexibility and capture the value primary and secondary users attach to spectrum access and usage. Spectrum trading between primary and secondary users is formalized as a utility maximization problem. Approximate solutions to this problem are derived and their performance is analyzed. The results show that spectrum trading, which combines revocable and exclusive leasing, provides higher utilities for both primary and secondary users. © 2014 Springer Science+Business Media New York

Coopetition spectrum trading - Creating endogenous spectrum holes

Dynamic spectrum access is an important way to alleviate the spectrum scarcity. Traditionally, secondary users are allowed to opportunistically operate when primary users are absent and buy idle bands from primary users. Although it improves the spectrum utility to some extents, it is not enough. In this paper, we argue that spectrum hole should be endogenous which means they should be negotiated by primary and secondary users. We proposed a novel spectrum sharing scheme with spectrum usage and management right. Further, we suggest spectrum trading as a financial option to capture the realistic usage and increase the trading flexibility. We show the superior of our model for primary users in deterministic and dynamic leasing environments. © 2013 ICST - The Institute for Computer Sciences, Social Informatics and Telecommunications Engineering

PERSPECTIVES DE MESURE DE LA PERFORMANCE DE LA GOUVERNANCE

Cet article a pour but de présenter une plus value en ce qui concerne la performance de la gouvernance dans une institution publique marocaine. Le choix a été porté sur la Trésorerie Générale du Royaume car elle est au cœur de la finance publique et par conséquent se présente comme un acteur majeur de la réalisation de la bonne gouvernance dans le secteur public. Ce travail a essayé d’approcher par description les notions de performance et de gouvernance. Puis, a tenté de construire des indicateurs de performance adaptés à la gouvernance dans un organisme public. Ensuite, cette recherche a analysé les données et résultats tirés de l’application de ces indicateurs sur le fonctionnement de la Trésorerie Générale

Apocrine carcinoma of the male breast: a case report of an exceptional tumor

Apocrine carcinoma of the male breast is an exceptional malignant tumor. It does not have a particular clinical or radiological appearance, but it's microscopically characterized by the presence of granular cells and foamy cells representing over 90% of tumor cells. These cells express most of the time the GCDFP-15 and the androgen receptors. This tumor is a distinct molecular entity. In this observation, we report the case of a 70 year old man presenting apocrine carcinoma of the left breast diagnosed at the stage of lung metastasis

Shadow replication: An energy-aware, fault-tolerant computational model for green cloud computing

As the demand for cloud computing continues to increase, cloud service providers face the daunting challenge to meet the negotiated SLA agreement, in terms of reliability and timely performance, while achieving cost-effectiveness. This challenge is increasingly compounded by the increasing likelihood of failure in large-scale clouds and the rising impact of energy consumption and CO2 emission on the environment. This paper proposes Shadow Replication, a novel fault-tolerance model for cloud computing, which seamlessly addresses failure at scale, while minimizing energy consumption and reducing its impact on the environment. The basic tenet of the model is to associate a suite of shadow processes to execute concurrently with the main process, but initially at a much reduced execution speed, to overcome failures as they occur. Two computationally-feasible schemes are proposed to achieve Shadow Replication. A performance evaluation framework is developed to analyze these schemes and compare their performance to traditional replication-based fault tolerance methods, focusing on the inherent tradeoff between fault tolerance, the specified SLA and profit maximization. The results show that Shadow Replication leads to significant energy reduction, and is better suited for compute-intensive execution models, where up to 30% more profit increase can be achieved due to reduced energy consumption