Le principe de précaution : un ‘nouveau’ rapport à la nature

Le principe de précaution révèle un changement majeur du rapport entre l’homme et la nature, perçue maintenant comme fin plutôt que comme moyen. Nous sommes passés d’un rapport historique dominant – dominé à un rapport d’interdépendance où la nature est devenue un objectif de l’activité humaine, objectif auquel le principe de précaution contribue par son éclairage sur les risques des innovations technologiques. Le principe de précaution transpose en particulier des pratiques médicales (notion de prudence, pharmaco-vigilance) aux pratiques environnementales, symbole de l’effacement de l’opposition entre intérieur (corps humain) et extérieur (nature). Le principe de précaution révèle donc l’intégration de la nature dans les fins de l’homme, un élargissement de la conscience humaine à son environnement, qui ne peut plus impunément être négligé ou oublié, et cela même au nom de l’incertitude scientifique

The Optimum design of Flat Rectrangular Concrete Plates supporting loads in Buidling structures and tests on a one-third full size experimental model

The popularity of concrete flat plate construction in Building Structures has soared in the last 20 years but their design has been based mainly on their ultimate strength rather than their behaviour in terms of deflection and cracking at working loads. As a result their deflections have been larger than anticipated and have caused displacements and severe cracks in masonry partitions which are being supported. In order to design any rectangular flat plate for optimum performance and economy most of the present design procedures such as the Elastic, Empirical, Yield-Line, Elastic-Plastic and Finite Difference, are reviewed, critically examined and illustrated by designing the same typical flat plate consisting of three bays in each direction for a uniformly distributed transverse load. Comparisons are made of the cost, strength and behaviour of each resulting plate

Capitalisme et économie de marché

Ever since they have been conceptually created in the middle of the 19 century, capitalism and market economy have been intertwined. Nevertheless, an accurate study of the definition of capitalism by the most eminent writers such as Marx, Weber, Schumpeter or Braudel, proves the existence of a wide array of definition, which tends to demonstrate a c1ear divergence between capitalism and market economy. Capitalism is therefore re-evaluated and redefined by the market power of shareholders, endured by employees as well as customers, yet socially accepted. Market economy is redefined by the freedom of enterprise as well as choice. Separating capitalism from market economy with these new definitions induces a new criticism of power and its abuse in the name of freedom, which sever capitalism from its traditional defense rhetoric.The notion of competition shifts from capitalism to market economy. Cooperation is added to the market economy, creating a goal of balance of powers rather than perfection as it was suggested by the neoclassical economies. Inscribed al the heart of the company, cooperation opens up a greater customer satisfaction, complementing competition. Corporate governance of a capitalist company, focused on the shareholders' interests, must evolve into balanced corporate governance, enabling compromises stemming from the divergent but legitimate interests of customers, employees, and shareholders. A new market economy with a clear balance of powers, shared between competition and cooperation, comes forth as the liberal, non-State solution to solving the capitalist power.Les termes capitalisme et économie de marché sont assimilés depuis le milieu du XIXème siècle, date de leur apparition sémantique. L'examen de la définition précise du capitalisme chez ses plus éminents auteurs, Marx, Weber, Schumpeter ou Braudel, révèle cependant chez chacun une définition différente, originale, qui démontre l'existence d'une divergence entre le capitalisme et l'économie de marché. Le capitalisme est donc réévalué et redéfini comme le pouvoir de marché des actionnaires, subi par les salariés comme par les clients mais accepté socialement, L'économie de marché est, elle, redéfinie par la liberté, d'entreprendre comme de choisir. La séparation du capitalisme et de l'économie de marché que ces définitions nouvelles apportent permet une critique nouvelle, du pouvoir en économie, et de ses abus, au nom de la liberté, qui prive le capitalisme de ses arguments de défense.La concurrence disparaît du capitalisme pour se retrouver au centre de l'économie de marché. S'y ajoute la coopération, créant un objectif d'équilibre des pouvoirs plutôt que de perfection comme le proposait l'économie néoclassique. La coopération, au coeur de l'entreprise, ouvre la possibilité nouvelle d'une meilleure satisfaction du client en complément de la concurrence. La gouvernance de l'entreprise capitaliste, dans l'intérêt des actionnaires, doit donc évoluer vers une gouvernance équilibrée, créatrice de compromis issus des intérêts légitimes mais divergents des clients, des salariés et des actionnaires. L'économie de marché d'équilibre des pouvoirs, intégrant la concurrence et la coopération, apparaît comme une solution libérale, non étatique, au pouvoir capitaliste

Cost-effectiveness of empagliflozin in heart failure patients irrespective of ejection fraction in England.

AIMS: Heart failure (HF) is a complex syndrome commonly categorized into two main phenotypes [left ventricular ejection fraction (LVEF) below or above 40%], and although empagliflozin is the first approved medication with proven clinical effectiveness for both phenotypes, its cost-effectiveness of treating the entire HF population remains unknown. METHODS: The analysis was performed utilizing two preexisting, LVEF phenotype-specific cost-effectiveness models to estimate the cost-effectiveness of empagliflozin in adults for the treatment of symptomatic chronic HF, irrespective of ejection fraction (EF). The results of the phenotype-specific models were combined using a population-weighted approach to estimate the deterministic and probabilistic incremental cost-effectiveness ratios (ICERs). RESULTS: Based on combined results, empagliflozin + standard of care (SoC) is associated with 6.13 life-years (LYs) and 3.92 quality-adjusted life-years (QALYs) compared with 5.98 LYs and 3.76 QALYs for SoC alone over a lifetime, resulting in an incremental difference of 0.15 LYs and 0.16 QALYs, respectively. Total lifetime healthcare costs per patient are £15 246 for empagliflozin + SoC and £13 982 for SoC giving an incremental difference of £1264. The ICER is £7757/QALY, which is substantially lower than the willingness-to-pay (WTP) of £30 000 per QALY used by NICE. The results of the probabilistic sensitivity analyses are in line with the deterministic results. CONCLUSION: Empagliflozin is the first efficacious, approved, and cost-effective treatment option for all HF patients, irrespective of EF. The combined ICER was consistently below the WTP threshold. Therefore, empagliflozin offers value for money for the treatment of the full HF population in England

A CD31-derived peptide prevents angiotensin II-induced atherosclerosis progression and aneurysm formation.

International audienceAIMS: The loss of the inhibitory receptor CD31 on peripheral T lymphocytes is associated with the incidence of atherosclerotic complications such as abdominal aortic aneurysms (AAA) in patients and plaque thrombosis in mice. However, we have recently discovered that a small fragment of extracellular CD31 remains expressed on the surface of the apparently 'CD31-negative' T-cells and that it is possible to restore the CD31-mediated T-cell inhibition in vivo by using a synthetic CD31-derived peptide. Here, we wanted to evaluate the therapeutic potential of the peptide in an experimental model of accelerated atherosclerosis and AAA formation. METHODS AND RESULTS: The effect of the murine CD31-derived peptide (aa 551-574, 1.5 mg/kg/day, sc) was evaluated on the extent of atherosclerotic plaques and the incidence of AAA in 28-week-old apolipoprotein E knockout mice (male, n ≥ 8/group) submitted to chronic angiotensin II infusion. The therapeutic mechanisms of the peptide were assessed by evaluating its effect on immune cell functions in vivo and in vitro. The prevalence of angiotensin II-induced AAA correlated with the loss of extracellular CD31 on T-cells. CD31 peptide treatment reduced both aneurysm formation and plaque size (P < 0.05 vs. control). Protection was associated with reduced perivascular leucocyte infiltration and T-cell activation in vivo. Functional in vitro studies showed that the peptide is able to suppress both T-cell and macrophage activation. CONCLUSION: CD31 peptides could represent a new class of drugs intended to prevent the inflammatory cell processes, such as those underlying progression of atherosclerosis and development of AAA

Identification of Restricted Subsets of Mature microRNA Abnormally Expressed in Inactive Colonic Mucosa of Patients with Inflammatory Bowel Disease

International audienceBACKGROUND: Ulcerative Colitis (UC) and Crohn's Disease (CD) are two chronic Inflammatory Bowel Diseases (IBD) affecting the intestinal mucosa. Current understanding of IBD pathogenesis points out the interplay of genetic events and environmental cues in the dysregulated immune response. We hypothesized that dysregulated microRNA (miRNA) expression may contribute to IBD pathogenesis. miRNAs are small, non-coding RNAs which prevent protein synthesis through translational suppression or mRNAs degradation, and regulate several physiological processes. METHODOLOGY/FINDINGS: Expression of mature miRNAs was studied by Q-PCR in inactive colonic mucosa of patients with UC (8), CD (8) and expressed relative to that observed in healthy controls (10). Only miRNAs with highly altered expression (>5 or 100 -fold and 0.05-0.19 -fold for over- and under- expression, respectively; 0.00

Primed T Cell Responses to Chemokines Are Regulated by the Immunoglobulin-Like Molecule CD31

CD31, an immunoglobulin-like molecule expressed by leukocytes and endothelial cells, is thought to contribute to the physiological regulation T cell homeostasis due to the presence of two immunotyrosine-based inhibitory motifs in its cytoplasmic tail. Indeed, loss of CD31 expression leads to uncontrolled T cell-mediated inflammation in a variety of experimental models of disease and certain CD31 polymorphisms correlate with increased disease severity in human graft-versus-host disease and atherosclerosis. The molecular mechanisms underlying CD31-mediated regulation of T cell responses have not yet been clarified. We here show that CD31-mediated signals attenuate T cell chemokinesis both in vitro and in vivo. This effect selectively affects activated/memory T lymphocytes, in which CD31 is clustered on the cell membrane where it segregates to the leading edge. We provide evidence that this molecular segregation, which does not occur in naïve T lymphocytes, might lead to cis-CD31 engagement on the same membrane and subsequent interference with the chemokine-induced PI3K/Akt signalling pathway. We propose that CD31-mediated modulation of memory T cell chemokinesis is a key mechanism by which this molecule contributes to the homeostatic regulation of effector T cell immunity

Insights on Glucocorticoid Receptor Activity Modulation through the Binding of Rigid Steroids

Background: The glucocorticoid receptor (GR) is a transcription factor that regulates gene expression in a ligand-dependent fashion. This modular protein is one of the major pharmacological targets due to its involvement in both cause and treatment of many human diseases. Intense efforts have been made to get information about the molecular basis of GR activity. Methodology/Principal Findings: Here, the behavior of four GR-ligand complexes with different glucocorticoid and antiglucocorticoid properties were evaluated. The ability of GR-ligand complexes to oligomerize in vivo was analyzed by performing the novel Number and Brightness assay. Results showed that most of GR molecules form homodimers inside the nucleus upon ligand binding. Additionally, in vitro GR-DNA binding analyses suggest that ligand structure modulates GRDNA interaction dynamics rather than the receptor's ability to bind DNA. On the other hand, by coimmunoprecipitation studies we evaluated the in vivo interaction between the transcriptional intermediary factor 2 (TIF2) coactivator and different GR-ligand complexes. No correlation was found between GR intranuclear distribution, cofactor recruitment and the homodimerization process. Finally, Molecular determinants that support the observed experimental GR LBD-ligand/TIF2 interaction were found by Molecular Dynamics simulation. Conclusions/Significance: The data presented here sustain the idea that in vivo GR homodimerization inside the nucleus can be achieved in a DNA-independent fashion, without ruling out a dependent pathway as well. Moreover, since at least one GR-ligand complex is able to induce homodimer formation while preventing TIF2 coactivator interaction, results suggest that these two events might be independent from each other. Finally, 21-hydroxy-6,19-epoxyprogesterone arises as a selective glucocorticoid with potential pharmacological interest. Taking into account that GR homodimerization and cofactor recruitment are considered essential steps in the receptor activation pathway, results presented here contribute to understand how specific ligands influence GR behavior. © 2010 Presman et al.Fil:Presman, D.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Alvarez, L.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Levi, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Martí, M.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Veleiro, A.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Burton, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Pecci, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina