De la crédiblité de la politique monétaire en Tunisie: pourquoi et comment?

The object of this paper is to determine an optimal rule of monetary policy for a small open economy. We introduced the uncovered interest parity to the model of Ball (1999). The coefficients obtained of the rule are lower than those found by Ball privileging exchange rate. The estimate of this model in the case of Tunisia made it possible to confirm the awaited theoretical results. As, it is necessary to announce as this rule of monetary policy remains effective under condition of its credibility.L’objet de ce travail est de déterminer une règle optimale de politique monétaire pour une petite économie ouverte. Pour ce faire, nous partons du modèle de Ball (1999) dans lequel l’on introduit la parité non couverte du taux d’intérêt. Les coefficients obtenus de la règle sont inférieurs à ceux trouvés par Ball privilégiant le taux de change. L’estimation de ce modèle pour le cas de la Tunisie a permis de confirmer les résultats théoriques attendus. Aussi, il y a lieu de signaler que cette règle de politique monétaire demeure efficace au vue des mesures à mettre en oeuvre afin de crédibiliser les actions des autorités monétaires

Oxidative stress and COPD: Polymorphism of glutathione S-transferase and contribution of clinical phytotherapy / Le stress oxydatif et la BPCO: Polymorphisme des glutathion- stransf\ue9rases et apport de la phytoth\ue9rapie clinique

The oxidative stress is incriminated as cause or consequence of numerous pathologies such as, the inflammatory syndromes, cancer, diabetes, as well as in chronic obstructive pulmonary disease (COPD). Researches were developed on the biological, clinical and molecular exploration of COPD. This pathology is characterized by an airflow limitation that is not fully reversible. Consequently, we attend an important back keeping of numerous environmental toxins in the respiratory system. The measures of personal exposure to tobacco smoke, dusts and professional chemicals, as well as internal and external air pollutants reduction are important objectives in the primary and secondary prevention of CPOD. The system purifying oxidative stress is complex. It includes enzymatic and non-enzymatic ways. Among the enzymatic families, the glutathione-S-transferases constitute an important agent of detoxification. The analysis of polymorphisms of genes coding these proteins was undertaken in the perspective of the research for a positive correlation with the oxidative stress. In COPD patients sample followed in hospitals of Central Tunisia, we detected an association of genotypes null-allele GSTM1 (p=0,02) and Val105/Val105 GSTP1 (p=0,001) with the development of the pathology. Besides in the prospect to contribute to the preventive efforts and to the improvement of the therapeutic solutions, we led an investigation with the followers of the clinical herbal medicine. Some plants facilitate the hepatic detoxification and several species are recommended for that purpose. We distinguish plants with vitamins and rich in trace elements (roots of Daucus carota, fruits of Rosa canina). We also privilege plants to active antioxidant principles as the ginkgo (ginkgolides, bilobalides), the thistle marries Silybum marianum (sylimarine) and even green tea (epigallocatechines)