Proposition d’un modèle de l’efficacité du co-commissariat aux comptes dans les sociétés anonymes cotées françaises.

Si le commissariat aux comptes est une institution reconnue par un large public, le co-commissariat aux comptes semble ignoré. Dans un contexte de remise en cause de la crédibilité des informations financières et de l’opinion de l’auditeur, nous nous interrogeons sur l’efficacité d’un double contrôle dans les SA cotées françaises. A partir du cadre conceptuel normatif de l’efficacité du co- commissariat aux comptes, nous proposons un modèle explicatif fondé sur le principe d’indépendance en apparence.If legal audit is an institution recognized by a wide public, joint audit seems unknown. As financial information and auditor opinion are challenged, we wonder about the efficiency of a joint audit regulation in French limited companies. From the normative conceptual framework of the efficiency of joint audit, we propose an explanatory model based on the appearance of independence.co-commissariat aux comptes; modèle; efficacité; indépendance en apparence; audit légal; SA cotées françaises;

PROPOSITION D'UN MODELE DE L'EFFICACITE DU CO-COMMISSARIAT AUX COMPTES DANS LES SOCIETES ANONYMES COTEES FRANÇAISES

Si le commissariat aux comptes est une institution reconnue par un large public, le co-commissariat aux comptes semble ignoré. Dans un contexte de remise en cause de la crédibilité des informations financières et de l'opinion de l'auditeur, nous nous interrogeons sur l'efficacité d'un double contrôle dans les SA cotées françaises. A partir du cadre conceptuel normatif de l'efficacité du cocommissariat aux comptes, nous proposons un modèle explicatif fondé sur le principe d'indépendance en apparence.co-commissariat aux comptes; modèle; efficacité; indépendance en apparence; audit légal; SA cotées françaises

Role of protein phosphatase-2A and -1 in the regulation of GSK-3, cdk5 and cdc2 and the phosphorylation of tau in rat forebrain

AbstractIn Alzheimer disease brain the activities of protein phosphatase (PP)-2A and PP-1 are decreased and the microtubule-associated protein tau is abnormally hyperphosphorylated at several sites at serine/threonine. Employing rat forebrain slices kept metabolically active in oxygenated artificial CSF as a model system, we investigated the role of PP-2A/PP-1 in the regulation of some of the major abnormally hyperphosphorylated sites of tau and the protein kinases involved. Treatment of the brain slices with 1.0 μM okadaic acid inhibited ∼65% of PP-2A and produced hyperphosphorylation of tau at Ser 198/199/202, Ser 396/404 and Ser 422. No significant changes in the activities of glycogen synthase kinase-3 (GSK-3) and cyclin dependent protein kinases cdk5 and cdc2 were observed. Calyculin A (0.1 μM) inhibited ∼50% PP-1, ∼20% PP-2A, 50% GSK-3 and ∼30% cdk5 but neither inhibited the activity of cyclin AMP dependent protein kinase A (PKA) nor resulted in the hyperphosphorylation of tau at any of the above sites. Treatment of brain slices with 1 μM okadaic acid plus 0.1 μM calyculin A inhibited ∼100% of both PP-2A and PP-1, ∼80% of GSK-3, ∼50% of cdk5 and ∼30% of cdc2 but neither inhibited PKA nor resulted in the hyperphosphorylation of tau at any of the above sites. These studies suggest (i) that PP-1 upregulates the phosphorylation of tau at Ser 198/199/202 and Ser 396/404 indirectly by regulating the activities of GSK-3, cdk5 and cdc2 whereas PP-2A regulates the phosphorylation of tau directly by dephosphorylation at the above sites, and (ii) that a decrease in the PP-2A activity leads to abnormal hyperphosphorylation of tau at Ser 198/199/202, Ser 396/404 and Ser 422

Numerical Investigation of Flow in a New DC Pump MHD

Electromagnetic pumps have several advantages to mechanical pumps. They offer maneuverability by directional thrust along with quietness and are conceived with an aim of eliminating all moving parts, being also free from problems of wear and tiredness of use. The flow field in the channel is treated as steady state, incompressible and fully developed laminar flow conditions. Our numerical code DCPMHD uses cylindrical coordinates (r,ϕ , z) and solves the incompressible MHD equations for magnetic vector potential A and fluid velocity V. Using finite volume method for numerical calculation. The numerical results of the performance characteristics of a DC electromagnetic pump are discussed and show that our new concept is capable to deliver bi-directional activation and have a satisfactory controllability, because of its proportional output force and input current relationship

Trypanosomiasis of camels (Camelus dromedarius) in Algeria: First report

Camel trypanosomosis is a life-threatening disease in the camel species and responsible for severe economic losses either in milk or meat productions. This study was carried out on the south-east area of Algeria on 100 camels of various ages and either sex from two herds. Microscopic examination of blood smears revealed higher levels of trypanosomosis caused by Trypanosoma evansi, an elongated parasite with a kinetoplast and a single nucleus located in its half-length and one flagellum with great heterogeneity. This first investigation reveals higher infection rate than those observed in other countries using blood smears, the trypanosomosis attack has reached an alarming level and the occurrence of trypanosomosis at this high level on blood smears is like "the tree that hides the forest" and make up a serious and potential danger both on animal and public health. Therefore, radical preventive and offensive drastic measures must be taken against this menacing disease at the critical points to prevent the economic losses and to avoid possible human transmission

Propofol Directly Increases Tau Phosphorylation

In Alzheimer's disease (AD) and other tauopathies, the microtubule-associated protein tau can undergo aberrant hyperphosphorylation potentially leading to the development of neurofibrillary pathology. Anesthetics have been previously shown to induce tau hyperphosphorylation through a mechanism involving hypothermia-induced inhibition of protein phosphatase 2A (PP2A) activity. However, the effects of propofol, a common clinically used intravenous anesthetic, on tau phosphorylation under normothermic conditions are unknown. We investigated the effects of a general anesthetic dose of propofol on levels of phosphorylated tau in the mouse hippocampus and cortex under normothermic conditions. Thirty min following the administration of propofol 250 mg/kg i.p., significant increases in tau phosphorylation were observed at the AT8, CP13, and PHF-1 phosphoepitopes in the hippocampus, as well as at AT8, PHF-1, MC6, pS262, and pS422 epitopes in the cortex. However, we did not detect somatodendritic relocalization of tau. In both brain regions, tau hyperphosphorylation persisted at the AT8 epitope 2 h following propofol, although the sedative effects of the drug were no longer evident at this time point. By 6 h following propofol, levels of phosphorylated tau at AT8 returned to control levels. An initial decrease in the activity and expression of PP2A were observed, suggesting that PP2A inhibition is at least partly responsible for the hyperphosphorylation of tau at multiple sites following 30 min of propofol exposure. We also examined tau phosphorylation in SH-SY5Y cells transfected to overexpress human tau. A 1 h exposure to a clinically relevant concentration of propofol in vitro was also associated with tau hyperphosphorylation. These findings suggest that propofol increases tau phosphorylation both in vivo and in vitro under normothermic conditions, and further studies are warranted to determine the impact of this anesthetic on the acceleration of neurofibrillary pathology

Multifaceted roles of GSK-3 and Wnt/β-catenin in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention

Glycogen synthase kinase-3 (GSK-3) is well documented to participate in a complex array of critical cellular processes. It was initially identified in rat skeletal muscle as a serine/threonine kinase that phosphorylated and inactivated glycogen synthase. This versatile protein is involved in numerous signaling pathways that influence metabolism, embryogenesis, differentiation, migration, cell cycle progression and survival. Recently, GSK-3 has been implicated in leukemia stem cell pathophysiology and may be an appropriate target for its eradication. In this review, we will discuss the roles that GSK-3 plays in hematopoiesis and leukemogenesis as how this pivotal kinase can interact with multiple signaling pathways such as: Wnt/β-catenin, phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR), Ras/Raf/MEK/extracellular signal-regulated kinase (ERK), Notch and others. Moreover, we will discuss how targeting GSK-3 and these other pathways can improve leukemia therapy and may overcome therapeutic resistance. In summary, GSK-3 is a crucial regulatory kinase interacting with multiple pathways to control various physiological processes, as well as leukemia stem cells, leukemia progression and therapeutic resistance. GSK-3 and Wnt are clearly intriguing therapeutic targets

Circuit Model of a Magneto-Hydrodynamic DC Pump

This paper focused on the study and the modeling of an original magneto-hydrodynamic DC pump. An analytic circuit model is deduced of an analytical field model and compared to results obtained through 2D FEM simulations

Magnetohydrodynamics approach for active decay heat removal system in future generation IV reactor

In this work, a helical-type magnetohydrodynamics transportation system for active decay-heat-removal system in a prototype fourth-generation sodium fast reactor was numerically analysed considering operational conditions of atmospheric pressure, for liquid sodium transportation in a loop. The prototype fourth-generation sodium fast reactor is a reactor with high uranium utilisation and an electric power output of 150 MWe, subjected to a developed pressure of 10kPa and flowrate of 0.005m(3)/s under a temperature condition of 468.75K for the active decay-heat-removal system. A helical-type magnetohydrodynamics transportation system was used to develop pressure in such a loop to reduce the current compared with that in a rectangular-type one; this could overcome the principal limitation of the requirement of a high current in a magnetohydrodynamics transportation system. The main parameters of the considered helical-type magnetohydrodynamics transportation system were the inner diameter, silver brazing, number of turns, and radius of pump, which affect the current, magnetic-flux density, and its velocity. The parameters were analysed in relation to the minimisation of the pump current while maximising the pressure. The specifications of the optimised helical-type magnetohydrodynamics transportation systemcurrent of 352 A and magnetic-flux density of 0.466Twere derived to satisfy the conditions of the active decay-heat-removal system