Essai de conceptualisation de l’attractivite des espaces ruraux Algeriens

L’article est une réflexion sur les espaces ruraux algériens et leur devenir. La progression rapide de  l’urbanisation, l’exode rural qui en découle et l’accentuation de la dépendance alimentaire posent la question du devenir des espaces ruraux dans un contexte d’ouverture économique et d’une volonté d’encourager la  métropolisation exprimée dans le schéma national d’aménagement du territoire (SNAT). Cette réflexion est un prolongement d’un travail de terrain effectué dans le cadre de la thèse de doctorat. A partir d’une enquête  auprès d’industriels ayant choisi de localiser leur entreprise dans des zones rurales pour connaître leurs motivations, nous nous interrogeons sur les facteurs d’attractivité des espaces ruraux algériens.MOTS CLEFS: Espaces ruraux, espaces urbains, attractivité, compétitivité, aménagement du territoir

Payoff inequity reduces the effectiveness of correlated-equilibrium recommendations

We examine theoretically and experimentally how individuals’ willingness to follow third-party recommendations in 2 × 2 games is affected by payoff asymmetry. We consider six versions of Battle-of-the-Sexes. Recommendations imply monetary payoffs that are equal ex ante, but unequal ex post. So, although following recommendations constitutes a Nash equilibrium under standard preferences, sufficiently inequity-averse players can rationally disobey a recommendation that would lead to a very unfavourable payoff distribution, as long as the cost of doing so is not too large. Our theoretical model incorporates inequity aversion, along with level-k reasoning. Our main experimental result is consistent with the model: as either payoff asymmetry increases or the cost of disobeying an unfavourable recommendation decreases, subjects are more likely to disobey recommendations

FORMULATION AND CHARACTERIZATION OF FLOATING BEADS OF ANTIBIOTIC BY EMULSION GELATION TECHNIQUE

Objective: The study aims at formulation and characterization of floating hydrogel beads of cefdinir for improving its bioavailability. Methods: Cefdinir is broad-spectrum, oral, third-generation cephalosporin antimicrobial agent active against Gram-positive and Gram-negative bacteria. The floating hydrogel beads of cefdinir were formulated with polymers such as sodium alginate and sodium carboxymethyl cellulose by emulsion gelation technique using olive oil/castor oil. The beads were evaluated for surface morphology, bead size, entrapment efficiency, floating characteristics, in vitro swelling, in vitro drug release, and stability studies. Results: On the basis of evaluation, all the beads show good swelling up to 12 h in 0.1 N hydrochloric acid. The swelling was followed by values in order of vegetable oil > mineral oil in case of emulsion gelation method. Scanning electron microscopy study shows that beads were spherical in shape. Comparing all the formulations, formulation FB12 was considered as optimized formulation which shows % yield 94.06±0.11, % floating 87.28±0.90, in vitro drug release 94.68, and also stable in stability studies. Conclusion: From the findings, it may be concluded that cefdinir-loaded floating beads were successfully prepared and proved to be useful for the better bioavailability and patient compliance for enhanced antimicrobial activity

Finding Community Structure with Performance Guarantees in Complex Networks

Many networks including social networks, computer networks, and biological networks are found to divide naturally into communities of densely connected individuals. Finding community structure is one of fundamental problems in network science. Since Newman's suggestion of using \emph{modularity} as a measure to qualify the goodness of community structures, many efficient methods to maximize modularity have been proposed but without a guarantee of optimality. In this paper, we propose two polynomial-time algorithms to the modularity maximization problem with theoretical performance guarantees. The first algorithm comes with a \emph{priori guarantee} that the modularity of found community structure is within a constant factor of the optimal modularity when the network has the power-law degree distribution. Despite being mainly of theoretical interest, to our best knowledge, this is the first approximation algorithm for finding community structure in networks. In our second algorithm, we propose a \emph{sparse metric}, a substantially faster linear programming method for maximizing modularity and apply a rounding technique based on this sparse metric with a \emph{posteriori approximation guarantee}. Our experiments show that the rounding algorithm returns the optimal solutions in most cases and are very scalable, that is, it can run on a network of a few thousand nodes whereas the LP solution in the literature only ran on a network of at most 235 nodes

Class II ADP-ribosylation factors are required for efficient secretion of Dengue viruses

This article is available open access through the publisher’s website.Identification and characterization of virus-host interactions are very important steps toward a better understanding of the molecular mechanisms responsible for disease progression and pathogenesis. To date, very few cellular factors involved in the life cycle of flaviviruses, which are important human pathogens, have been described. In this study, we demonstrate a crucial role for class II Arf proteins (Arf4 and Arf5) in the dengue flavivirus life cycle. We show that simultaneous depletion of Arf4 and Arf5 blocks recombinant subviral particle secretion for all four dengue serotypes. Immunostaining analysis suggests that class II Arf proteins are required at an early pre-Golgi step for dengue virus secretion. Using a horseradish peroxidase protein fused to a signal peptide, we show that class II Arfs act specifically on dengue virus secretion without altering the secretion of proteins through the constitutive secretory pathway. Co-immunoprecipitation data demonstrate that the dengue prM glycoprotein interacts with class II Arf proteins but not through its C-terminal VXPX motif. Finally, experiments performed with replication-competent dengue and yellow fever viruses demonstrate that the depletion of class II Arfs inhibits virus secretion, thus confirming their implication in the virus life cycle, although data obtained with West Nile virus pointed out the differences in virus-host interactions among flaviviruses. Our findings shed new light on a molecular mechanism used by dengue viruses during the late stages of the life cycle and demonstrate a novel function for class II Arf proteins.Research Fund for Control of Infectious Diseases of Hong Kong and BNP Paribas Corporate and Investment Banking

Correlation between biomarkers of exposure, effect and potential harm in the urine of electronic cigarette users.

ObjectivesTo determine if urinary biomarkers of effect and potential harm are elevated in electronic cigarette users compared with non-smokers and if elevation correlates with increased concentrations of metals in urine.Study design and settingThis was a cross-sectional study of biomarkers of exposure, effect and potential harm in urine from non-smokers (n=20), electronic cigarette users (n=20) and cigarette smokers (n=13). Participant's screening and urine collection were performed at the Roswell Park Comprehensive Cancer Center, and biomarker analysis and metal analysis were performed at the University of California, Riverside.ResultsMetallothionein was significantly elevated in the electronic cigarette group (3761±3932 pg/mg) compared with the non-smokers (1129±1294 pg/mg, p=0.05). 8-OHdG (8-hydroxy-2'-deoxyguanosine) was significantly elevated in electronic cigarette users (442.8±300.7 ng/mg) versus non-smokers (221.6±157.8 ng/mg, p=0.01). 8-Isoprostane showed a significant increase in electronic cigarette users (750.8±433 pg/mg) versus non-smokers (411.2±287.4 pg/mg, p=0.03). Linear regression analysis in the electronic cigarette group showed a significant correlation between cotinine and total metal concentration; total metal concentration and metallothionein; cotinine and oxidative DNA damage; and total metal concentration and oxidative DNA damage. Zinc was significantly elevated in the electronic cigarette users (584.5±826.6 µg/g) compared with non-smokers (413.6±233.7 µg/g, p=0.03). Linear regression analysis showed a significant correlation between urinary zinc concentration and 8-OHdG in the electronic cigarette users.ConclusionsThis study is the first to investigate biomarkers of potential harm and effect in electronic cigarette users and to show a linkage to metal exposure. The biomarker levels in electronic cigarette users were similar to (and not lower than) cigarette smokers. In electronic cigarette users, there was a link to elevated total metal exposure and oxidative DNA damage. Specifically, our results demonstrate that zinc concentration was correlated to oxidative DNA damage