La modélisation des trajectoires professionnelles dans le modèle Prisme

Le modèle de microsimulation de la Cnav, Prisme (Projection des retraites individuelles : simulation, modélisation, évaluation), a été créé en 2004. Ce modèle répondait à un besoin d’évaluation des effets des réformes des retraites, tant du point de vue financier pour le régime, que du point de vue de l’assuré, à travers l’évolution de son montant de pension ou de son âge de liquidation. Les nombreuses non‑linéarités induites par le mode de calcul de la retraite au Régime Général ont rendu nécessaires les évaluations basées sur un grand nombre de situations individuelles, ce qui est l’essence même de la microsimulation. Prisme repose sur les fichiers de gestion de la Cnav retraçant la totalité de la carrière des assurés au régime général et, de plus en plus, dans les autres régimes. Il s’appuie sur un échantillon au 1/ 20e de près de 5 millions d’individus. Le module «carrière » permet de modéliser les statuts d’activité de chaque individu pour chaque année et chaque trimestre projetés. Il permet ainsi de simuler le partage de la population entre actifs et inactifs, et au sein des actifs, entre salariés du régime général, salariés d’autres régimes (alignés et non alignés), chômeurs, salariés en arrêt maladie, invalides. Depuis 2009, ces situations sont modélisées par un enchaînement d’équations logistiques, estimées sur les transitions de carrières des années 2005 à 2007. Elles sont déclinées par genre, tranches d’âge glissantes et lieu de naissance. Un salaire annuel est ensuite attribué aux individus pour lesquels un report d’activité salarié au régime général est affecté. Le module «carrière » permet donc de simuler de manière fine les trajectoires professionnelles des individus et d’estimer les conditions de leur départ (date de départ, durées d’assurance, montant de leur retraite, etc.). Des indicateurs de suivi des carrières projetées sont présentés dans ce papier et permettent ainsi de valider la cohérence de cette modélisation.Berteau‑Rapin Caroline, Beurnier Paul, Denayrolles Émilie. La modélisation des trajectoires professionnelles dans le modèle Prisme. In: Economie et statistique, n°481-482, 2015. Microsimulation appliquée aux politiques fiscales et sociales. pp. 97-120

Two allelic genes responsible for vegetative incompatibility in the fungus Podospora anserina are not essential for cell viability

International audienceVegetative incompatibility is a lethal reaction that destroys the heterokaryotic cells formed by the fusion of hyphae of non-isogenic strains in many fungi. That incompatibility is genetically determined is well known but the function of the genes triggering this rapid cell death is not. The two allelic incompatibility genes, s and S, of the fungus Podospora anserina were characterized. Both encode 30 kDa polypeptides, which differ by 14 amino acids between the two genes. These two proteins are responsible for the incompatibility reaction that results when cells containing s and S genes fuse. Inactivation of the s or S gene by disruption suppresses incompatibility but does not affect the growth or the sexual cycle of the mutant strains. This suggests that these incompatibility genes have no essential function in the life cycle of the fungus

Removing isoflavones from modern soyfood: Why and how?

AbstractEstrogenic isoflavones were found, in the 1940s, to disrupt ewe reproduction and were identified in soy-consumers’ urine in 1982. This led to controversy about their safety, often supported by current Asian diet measurements, but not by historical data. Traditional Asian recipes of soy were tested while assaying soy glycosilated isoflavones. As these compounds are water-soluble, their concentration is reduced by soaking. Pre-cooking or simmering time-dependently reduces the isoflavone:protein ratio in Tofu. Cooking soy-juice for 15 or 60min decreases the isoflavone:protein ratios in Tofu from 6.90 to 3.57 and 1.80, respectively (p<0.001). Traditional Tempeh contains only 18.07% of the original soybean isoflavones (p<0.001). Soy-juice isoflavones were reduced by ultra-filtration (6.54 vs 1.24 isoflavone:protein; p<0.001). Soy-protein and isoflavones are dissociated by water rinsing and prolonged cooking, but these have no equivalent in modern processes. As regards human health, a precise definition of the safety level of isoflavone intake requires additional studies

Traditional and Domestic Cooking Dramatically Reduce Estrogenic Isoflavones in Soy Foods

Soybean is a pulse which has considerable nutritional value due to its high protein, fibers and polyunsaturated fatty acid (PUFA) contents. It also contains phytoestrogenic compounds that definitely hinder its recommendation for general consumption. Contrary to ancient times, when soybeans were boiled, modern commercial soy foods can contain up to 150 mg/100g of estrogenic isoflavones. Interestingly, current estimations of isoflavone intake in the literature do not distinguish between the origins of soy food, i.e., whether it is homemade or commercial. As a result, the isoflavone exposure in Asian countries may well be overestimated. This study aims to demonstrate, based on step-by-step monitoring of isoflavones, that traditional and domestic treatments, leveraging isoflavones water-solubility, can indeed significantly reduce their content in soy foods. Indeed, when compared to commercial foods, the isoflavone content was found to be 20, 2.6, 4.5 and 9.8 times lower in &ldquo;homemade&rdquo; soy juice, tofu, tempeh and miso, respectively. Additionally, water soaking was found to reduce the isoflavones levels in soy-textured proteins by more than 70%. Hence, this simple process has the potential to help drastically reduce overall xenoestrogens exposure. This study could serve as a basis for establishing the isoflavones Reference Dose and issuing food safety guidelines

Evolution of Sensory Properties of Beef during Long Dry Ageing

Ageing is an essential step in obtaining meat with satisfactory sensory properties. Dry-ageing, although being a niche practice, is increasingly being developed to enhance the taste experience of meat consumers. In this work, we studied the kinetics of the evolution of muscle properties with increasing ageing time, in order to propose an optimal duration, allowing a compromise between quality and meat weight loss reduction. Our study was performed on 32 samples from 8 animals for which the Longissimus thoracis sensory properties were analysed at different stages of ageing (7, 16, 35 and 60-days post-slaughter). This work showed an increase in the dry matter content of meat with increasing ageing duration, concomitant with a slight increase in pH. Although the luminance of the meat is stabilized after 14-days, the red and yellow indices decrease until 35-days of ageing. Iron content also decreases with ageing duration. Finally, the kinetic evolution of muscle rheological properties indicates that the toughness decreases at least up to 35-days on raw meat. Cooking seems to homogenise the tenderness of the samples, no difference was noticed between the different ageing durations when meat was cooked. These first experimental data need to be confirmed with different animal types