Joint Hybrid Backhaul and Access Links Design in Cloud-Radio Access Networks

The cloud-radio access network (CRAN) is expected to be the core network architecture for next generation mobile radio systems. In this paper, we consider the downlink of a CRAN formed of one central processor (the cloud) and several base-station (BS), where each BS is connected to the cloud via either a wireless or capacity-limited wireline backhaul link. The paper addresses the joint design of the hybrid backhaul links (i.e., designing the wireline and wireless backhaul connections from the cloud to the BSs) and the access links (i.e., determining the sparse beamforming solution from the BSs to the users). The paper formulates the hybrid backhaul and access link design problem by minimizing the total network power consumption. The paper solves the problem using a two-stage heuristic algorithm. At one stage, the sparse beamforming solution is found using a weighted mixed `1=`2 norm minimization approach; the correlation matrix of the quantization noise of the wireline backhaul links is computed using the classical rate-distortion theory. At the second stage, the transmit powers of the wireless backhaul links are found by solving a power minimization problem subject to quality-of-service constraints, based on the principle of conservation of rate by utilizing the rates found in the first stage. Simulation results suggest that the performance of the proposed algorithm approaches the global optimum solution, especially at high signal-to-interference-plus-noise ratio (SINR).Comment: 6 pages, 3 figures, IWCPM 201

Dilatation de bronches séquellaire d’une tuberculose pulmonaire au cours d’un syndrome de Rhupus

La fréquence de la tuberculose est beaucoup plus élevée au cours des maladies systémiques que dans la population générale, il s'agit le plus souvent de la réactivation d'une tuberculose latente. A côté de l'immunodépression induite par la maladie sous-jacente, il faut souligner le rôle favorisant des glucocorticoïdes et des traitements immunosuppresseurs. Nous rapportons un cas de tuberculose pulmonaire compliquée d'une dilatation des broches (DDB) au cours d'une entité très rare appelée rhupus syndrome (lupus érythémateux systémique et polyarthrite rhumatoïde). Une patiente âgée de 41 ans suivie depuis 10 ans pour rhupussyndrome, elle était mise sous corticothérapie à fortes doses associée à des anti paludéens de synthèse et du méthotrexate. L'évolution ultérieure était marquée par l'amélioration de la  symptomatologie cutanée et articulaire avec l'apparition d'une symptomatologie respiratoire trainante et récidivante. Le dernier épisode était marqué par une fièvre à 39°, une asthénie, un amaigrissement, une dyspnée et une toux. Le bilan tuberculeux était positif et la radiographie thoracique montrait un foyer de dilatation des bronches lobaire supérieur droit séquellaire d'une tuberculose pulmonaire. La patiente était mise antituberculeux avec bonne amélioration clinique et radiologique.Pan African Medical Journal 2015; 2

Evaluation of the antioxidant and antibacterial activities of Tunisian Artemisia Herba-alba essential oil

Tunisia is characterized by a climate that allows the proliferation of many plants rich in active substances with multiple biological activities and can replace the use of antioxidants and synthetic antibiotics. For this reason, Artemisia leaves and twigs were collected from the central region of Tunisia (Thala). The essential oil was extracted using hydro-distillation and analyzed using GC/MS, the antioxidant activity of Artemisia Herba-alba was evaluated by the DPPH test and the antibacterial powers against four bacterial strains was measured by the agar well method diffusion. GC/MS results showed that the main components of Artemisia Herba-alba essential oil were ?-thujone (23.9 %) and chrysanthenone (17.4%). Indeed, the results showed a potent antioxidant effect (85.2 % inhibition of free radicals DPPH) and the IC50 value was 84.8 µg/ml. Concerning the antibacterial activity, the oil was active against Gram-negative and Gram-positive bacteria. A strong effect was observed against Salmonella (29mm) and Bacillus (22.5 mm). To conclude, the antioxidant power and the antibacterial activity are strongly correlated with the chemical composition of the essential oil. Keywords: Artemisia Herba-alba, essential oil, antioxidant activity, antibacterial activit

In vitro ruminal fermentation, nutritional evaluation and antioxidant activity of some forest shrubs of North West Tunisia for goats

Chemical composition and characteristics of in vitro fermentation were determined for two shrubs (Genista aspalathoides and Rhamnus alaternus) collected from north western Tunisia. The primary and secondary chemical composition was determined and in vitro fermentation parameters were measured in 100 ml glass syringes for 48 hours to determine gas production. There are significant differences in chemical and wall composition for the two shrubs studied (p < 0.05). Rhamnus alaternus is richer in secondary metabolites (59.2 mg GAE / g DM) than Genista aspalathoides and has the highest content of crude protein (CP). Genista aspalathoides had the lowest anti-radical activity since it has the highest levels of secondary metabolites, so it is the most digestible species with the highest value of gas production after 24 hours incubation and released more methane than Rhamnus alaternus. Keywords: Shrub, Chemical composition, in vitro fermentation, antioxidant activity, methan

Comparison of Judgements Made by Managers of State Farms (Agro-combinats) and of Agricultural Cooperatives (U.C.P.) In Tunisia Regarding Skills and Training Needed

Agricultural Educatio