Descent methods for equilibrium problems in a banach space

In this paper, we consider equilibrium problems with differentiable bifunctions in a Banach space setting and investigate properties of gap functions for such problems. We suggest a derivative-free descent method and give conditions which provide strong convergence of the method. © 2004 Elsevier Ltd. AU rights reserved

La gestion de l’eau d’irrigation par application de la théorie des jeux : cas de la région d’AL Haouz

In Morocco, water resources are limited and in most cases exposed to over-exploitation and degradation by actors with their non-rational behavior seeking to maximize their own profits until the resource is depleted. This competition to access a limited resource will provoke a conflict of interest between the different actors using this resource. This work was carried out in the El Haouz area with the objective of proposing the most relevant strategy for a good management of irrigation water resource. The game theory has been applied to the case study based on the prisoner's dilemma, as this methodology is typical of conflicts of interest around the use of natural resources. This methodology has contributed to identify the problems and suggest solutions adapted to the case study. Despite the difficulties encountered in bringing together the behaviors of the various actors, contracting policy appears to be a good alternative to achieve the objective of an integrated management of irrigation water while associating social welfare, economic and environmental well-being.Au Maroc, les ressources en eau sont limitées et sont dans la plupart des cas exposées à la surexploitation et à la dégradation par des individus avec leurs comportements non rationnel cherchant à maximiser leurs profits jusqu’à l’épuisement de la ressource. Cette situation de compétition pour l’accès à une ressource limitée va provoquer un conflit d’intérêt entre les différents individus usagers de cette ressource. Ce travail a été réalisé dans la zone d’El Haouz et dont l’objectif est d’identifier la meilleure stratégie de gestion de l’eau d’irrigation. La théorie de jeux a été appliquée au cas d’étude en se basant sur le dilemme du prisonnier vue que cette méthodologie est le cas typique des conflits d’intérêt autours de l’usage des ressources naturelles. Cette méthodologie a permis d’identifier les problèmes et proposer des solutions adaptées au cas d’étude. Il ressort que, malgré les difficultés rencontrées pour rapprocher les comportements des différents acteurs, la contractualisation semble être une bonne alternative pour atteindre l’objectif d’une gestion intégrée des eaux d’irrigation (Optimum de Pareto) tout en associant le bien-être social, économique et environnemental

Le carcinome indifférencié des glandes salivaires

Le carcinome indifferencie primitif des glandes salivaires est rare. Son association avec le virus Epstein Barr, initialement decrite chez les esquimaux, est retrouvee dans la majorite des cas publies. Nous rapportons un nouveau cas tunisien survenu chez un homme age de 64 ans, revele par une tumefaction de la glande parotide gauche. Microscopiquement se discutait le caractere primitif ou secondaire de la tumeur, etaye par les examens complementaires. Le patient etait traite par une parotidectomie suivie d’un curage ganglionnaire et d’une radiotherapie. L’evolution etait favorable apres un an de recul.  Mots clès : Glande salivaire- Carcinome indifferencie- Virus Epstein Bar

Radiofrequency ablation versus hepatic resection for hepatocellular carcinoma within the Milan criteria – A comparative study

AbstractBackgroundTo compare the results of radiofrequency ablation (RFA) with hepatic resection in the treatment of hepatocellular carcinoma (HCC) within the Milan criteria.MethodsA nonrandomized comparative study was performed with 111 consecutive patients who underwent laparoscopic RFA (n = 31) or curative hepatic resection (n = 80) for HCC within Milan criteria.ResultsProcedure related complications were less often and severe after RFA than resection (3.2% vs. 25%). There was no significant difference in hospital mortality (0% vs. 3.8%). Hospital stay was significantly shorter in the RFA group than in the resection group (mean, 3.8 vs. 6.8 days). The 1-, 3-, and 5-year disease-free survival rates for the RFA group and the resection group were 76%, 40%, 40% and 76%, 60%, 60%, respectively. Disease-free survival was significantly lower in the RFA group than in the resection group. The corresponding 1-, 3-, and 5-year overall survival rates for the RFA group and the resection group were 100%, 92%, 84%, and 92%, 75%, 71%, respectively. The overall survival for RFA and resection were not significantly different.ConclusionsOur result showed comparable overall survival between RFA and surgery, although RFA was associated with a significantly higher tumor recurrence rate. RFA had the advantages over surgical resection in being less invasive and having lower morbidity

Association of the MTHFR A1298C Variant with Unexplained Severe Male Infertility

The methylenetetrahydrofolate reductase (MTHFR) gene is one of the main regulatory enzymes involved in folate metabolism, DNA synthesis and remethylation reactions. The influence of MTHFR variants on male infertility is not completely understood. The objective of this study was to analyze the distribution of the MTHFR C677T and A1298C variants using PCR-Restriction Fragment Length Polymorphism (RFLP) in a case group consisting of 344 men with unexplained reduced sperm counts compared to 617 ancestry-matched fertile or normozoospermic controls. The Chi square test was used to analyze the genotype distributions of MTHFR polymorphisms. Our data indicated a lack of association of the C677T variant with infertility. However, the homozygous (C/C) A1298C polymorphism of the MTHFR gene was present at a statistically high significance in severe oligozoospermia group compared with controls (OR = 3.372, 95% confidence interval CI = 1.27–8.238; p = 0.01431). The genotype distribution of the A1298C variants showed significant deviation from the expected Hardy-Weinberg equilibrium, suggesting that purifying selection may be acting on the 1298CC genotype. Further studies are necessary to determine the influence of the environment, especially the consumption of diet folate on sperm counts of men with different MTHFR variants

Local Modelling Techniques for Assessing Micro-Level Impacts of Risk Factors in Complex Data: Understanding Health and Socioeconomic Inequalities in Childhood Educational Attainments

Although inequalities in health and socioeconomic status have an important influence on childhood educational performance, the interactions between these multiple factors relating to variation in educational outcomes at micro-level is unknown, and how to evaluate the many possible interactions of these factors is not well established. This paper aims to examine multi-dimensional deprivation factors and their impact on childhood educational outcomes at micro-level, focusing on geographic areas having widely different disparity patterns, in which each area is characterised by six deprivation domains (Income, Health, Geographical Access to Services, Housing, Physical Environment, and Community Safety). Traditional health statistical studies tend to use one global model to describe the whole population for macro-analysis. In this paper, we combine linked educational and deprivation data across small areas (median population of 1500), then use a local modelling technique, the Takagi-Sugeno fuzzy system, to predict area educational outcomes at ages 7 and 11. We define two new metrics, “Micro-impact of Domain” and “Contribution of Domain”, to quantify the variations of local impacts of multidimensional factors on educational outcomes across small areas. The two metrics highlight differing priorities. Our study reveals complex multi-way interactions between the deprivation domains, which could not be provided by traditional health statistical methods based on single global model. We demonstrate that although Income has an expected central role, all domains contribute, and in some areas Health, Environment, Access to Services, Housing and Community Safety each could be the dominant factor. Thus the relative importance of health and socioeconomic factors varies considerably for different areas, depending on the levels of each of the other factors, and therefore each component of deprivation must be considered as part of a wider system. Childhood educational achievement could benefit from policies and intervention strategies that are tailored to the local geographic areas' profiles

Probing Molecular Mechanisms of the Hsp90 Chaperone: Biophysical Modeling Identifies Key Regulators of Functional Dynamics

Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based “conformational selection” of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected residue clusters may be a rather general functional requirement encoded across molecular chaperones. The obtained insights may be useful in guiding discovery of allosteric Hsp90 inhibitors targeting protein interfaces with co-chaperones and protein binding clients