1,069 research outputs found

    Que valent les engagements des régimes de retraite envers les retraités en France ?

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    Using the "Echantillon Inter régimes des Retraités" (EIR) 2008 and 2012 panel data, we calculate retirees\u27 pension wealth (consumed and residual) at an aggregated level, and provide in-depth results by type of pension scheme and by managing organism. We put an emphasis on direct pensions already perceived by retirees and to be paid in the future, without taking into account current contributors\u27 future retirement. We find that the overall pension wealth is not very sensitive to the discount rate, but this result does not hold if we concentrate on the future pension wealth. From this point of view, it must be noted that some of the organisms have a high proportion of pension still to be paid. Moreover, whatever the type of pension wealth calculated, the results show a rapid increase from 2008 to 2012 (except for the basic scheme of farmers). Finally, spread indicators and Gini index of pension wealth are relatively higher than those found in the distribution of labor income by other studies. We find that there are more inequalities in the private sector than in the public, particularly in the private sector for complementary pension schemes

    Pension Wealth in France: An Assessment on Panel Data

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    This contribution proposes a measure of pension wealth in the French public PAYG schemes (first and second pillar schemes) and of its distribution among the population of retirees in 2008 using the Echantillon Inter rĂ©gimes de RetraitĂ©s (EIR) panel data. We show that aggregate pension wealth amounts to around 4765 billion Euros assuming a 2 percent discount rate. There are significant differences in the amount of individual’s pension wealth between the pension schemes of the private and public sector. Moreover, there is more inequality in the distribution of pension wealth among private sector retirees than public sectorones

    Charge redistribution at Pd surfaces: ab initio grounds for tight-binding interatomic potentials

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    A simplified tight-binding description of the electronic structure is often necessary for complex studies of surfaces of transition metal compounds. This requires a self-consistent parametrization of the charge redistribution, which is not obvious for late transition series elements (such as Pd, Cu, Au), for which not only d but also s-p electrons have to be taken into account. We show here, with the help of an ab initio FP-LMTO approach, that for these elements the electronic charge is unchanged from bulk to the surface, not only per site but also per orbital. This implies different level shifts for each orbital in order to achieve this orbital neutrality rule. Our results invalidate any neutrality rule which would allow charge redistribution between orbitals to ensure a common rigid shift for all of them. Moreover, in the case of Pd, the power law which governs the variation of band energy with respect to coordination number, is found to differ significantly from the usual tight-binding square root.Comment: 6 pages, 2 figures, Latex; Phys.Rev. B 56 (1997

    La réforme des retraites de 1993 : quel impact sur l'équivalent patrimonial des droits à retraite ?

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    Depuis 1993, la France a enregistrĂ© plusieurs rĂ©formes de son systĂšme de retraites, visant avant tout Ă  en assurer la soutenabilitĂ©. Cette contribution a pour objectif d’évaluer l’impact de la rĂ©forme de 1993 sur l’équivalent patrimonial des droits individuels Ă  la retraite (EPDR), c\u27est-Ă -dire la somme actuarielle probable des pensions Ă  recevoir, de la date de liquidation des droits jusqu’au dĂ©cĂšs. Plus prĂ©cisĂ©ment, nous mesurons l’impact de cette rĂ©forme sur l’EPDR des mono-pensionnĂ©s du rĂ©gime gĂ©nĂ©ral, Ă  l’aide des donnĂ©es de l’Echantillon InterrĂ©gimes de RetraitĂ©s 2008. Parmi les mesures phares de la rĂ©forme de 1993 figure l’augmentation progressive de la durĂ©e de cotisation nĂ©cessaire pour obtenir une retraite Ă  taux plein au rĂ©gime gĂ©nĂ©ral. Cette augmentation est susceptible d’engendrer deux effets opposĂ©s : un effet de report de l’ñge de liquidation pour conserver un EPDR adĂ©quat pour ses vieux jours (voire l’augmenter) ou un effet de dĂ©cote, si l’assurĂ©-e ne souhaite, ou ne peut, pas prolonger son activitĂ© et subit donc une dĂ©cote sur sa pension, et partant sur son EPDR. Pour tester les effets nets de la rĂ©forme de 1993 sur l’EPDR, nous procĂ©dons Ă  des estimations Ă©conomĂ©triques en diffĂ©rences premiĂšres et en doubles diffĂ©rences, ainsi qu’à des estimations par quantiles pour mesurer les impacts le long de la distribution de l’EPDR. Nos estimations montrent des rĂ©sultats diffĂ©rents selon que les individus partent avant ou aprĂšs 2004, date d’entrĂ©e en vigueur de la rĂ©forme. Ainsi, toutes choses Ă©gales par ailleurs, un dĂ©part en retraite avant 2004 plutĂŽt que postĂ©rieurement, augmente l’EPDR des retraitĂ©s concernĂ©s. Toutefois, l’interaction avec les autres variables nuance cette conclusion. D’une part, reporter son dĂ©part en retraite rĂ©duit l’EPDR moyen d’environ 20% : le report permet d’accumuler des droits supplĂ©mentaires, mais sur une pĂ©riode rĂ©duite. D’autre part, l’effet de la dĂ©cote est nĂ©gatif, mais son intensitĂ© est rĂ©duite quand les retraitĂ©s reportent leur dĂ©part. En outre, comme les gĂ©nĂ©rations 1934-1943 ont subi conjointement les rĂ©formes de 1993 et 2003, nos estimations en double diffĂ©rence permettent d’isoler l’effet « pur » de la rĂ©forme de 1993 : lorsque les affiliĂ©s ont subi une dĂ©cote, sans avoir reportĂ© leur dĂ©part en retraite pour l’attĂ©nuer, la liquidation des droits aux conditions de 2003 par rapport aux conditions de 1993 est la plus dĂ©favorable. Enfin, les estimations par quantiles montrent que ces effets s’intensifient dans la premiĂšre moitiĂ© de la distribution, et s’attĂ©nuent au-delĂ 

    Surfactant effect in heteroepitaxial growth. The Pb - Co/Cu(111) case

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    A MonteCarlo simulations study has been performed in order to study the effect of Pb as surfactant on the initial growth stage of Co/Cu(111). The main characteristics of Co growing over Cu(111) face, i.e. the decorated double layer steps, the multiple layer islands and the pools of vacancies, disappear with the pre-evaporation of a Pb monolayer. Through MC simulations, a full picture of these complex processes is obtained. Co quickly diffuses through the Pb monolayer exchanging place with Cu atoms at the substrate. The exchange process diffusion inhibits the formation of pure Co islands, reducing the surface stress and then the formation of multilayer islands and the pools of vacancies. On the other hand, the random exchange also suppress the nucleation preferential sites generated by Co atoms at Cu steps, responsible of the step decoration.Comment: 4 pages, latex, 2 figures embedded in the tex

    Low number of neurosecretory vesicles in neuroblastoma impairs massive catecholamine release and prevents hypertension

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    Introduction: Neuroblastoma (NB) is a pediatric cancer of the developing sympathetic nervous system. It produces and releases metanephrines, which are used as biomarkers for diagnosis in plasma and urine. However, plasma catecholamine concentrations remain generally normal in children with NB. Thus, unlike pheochromocytoma and paraganglioma (PHEO/PGL), two other non-epithelial neuroendocrine tumors, hypertension is not part of the usual clinical picture of patients with NB. This suggests that the mode of production and secretion of catecholamines and metanephrines in NB is different from that in PHEO/PGL, but little is known about these discrepancies. Here we aim to provide a detailed comparison of the biosynthesis, metabolism and storage of catecholamines and metanephrines between patients with NB and PHEO. Method: Catecholamines and metanephrines were quantified in NB and PHEO/PGL patients from plasma and tumor tissues by ultra-high pressure liquid chromatography tandem mass spectrometry. Electron microscopy was used to quantify neurosecretory vesicles within cells derived from PHEO tumor biopsies, NB-PDX and NB cell lines. Chromaffin markers were detected by qPCR, IHC and/or immunoblotting. Results: Plasma levels of metanephrines were comparable between NB and PHEO patients, while catecholamines were 3.5-fold lower in NB vs PHEO affected individuals. However, we observed that intratumoral concentrations of metanephrines and catecholamines measured in NB were several orders of magnitude lower than in PHEO. Cellular and molecular analyses revealed that NB cell lines, primary cells dissociated from human tumor biopsies as well as cells from patient-derived xenograft tumors (NB-PDX) stored a very low amount of intracellular catecholamines, and contained only rare neurosecretory vesicles relative to PHEO cells. In addition, primary NB expressed reduced levels of numerous chromaffin markers, as compared to PHEO/PGL, except catechol O-methyltransferase and monoamine oxidase A. Furthermore, functional assays through induction of chromaffin differentiation of the IMR32 NB cell line with Bt2cAMP led to an increase of neurosecretory vesicles able to secrete catecholamines after KCl or nicotine stimulation. Conclusion: The low amount of neurosecretory vesicles in NB cytoplasm prevents catecholamine storage and lead to their rapid transformation by catechol O-methyltransferase into metanephrines that diffuse in blood. Hence, in contrast to PHEO/PGL, catecholamines are not secreted massively in the blood, which explains why systemic hypertension is not observed in most patients with NB

    Low number of neurosecretory vesicles in neuroblastoma impairs massive catecholamine release and prevents hypertension.

    Get PDF
    Neuroblastoma (NB) is a pediatric cancer of the developing sympathetic nervous system. It produces and releases metanephrines, which are used as biomarkers for diagnosis in plasma and urine. However, plasma catecholamine concentrations remain generally normal in children with NB. Thus, unlike pheochromocytoma and paraganglioma (PHEO/PGL), two other non-epithelial neuroendocrine tumors, hypertension is not part of the usual clinical picture of patients with NB. This suggests that the mode of production and secretion of catecholamines and metanephrines in NB is different from that in PHEO/PGL, but little is known about these discrepancies. Here we aim to provide a detailed comparison of the biosynthesis, metabolism and storage of catecholamines and metanephrines between patients with NB and PHEO. Catecholamines and metanephrines were quantified in NB and PHEO/PGL patients from plasma and tumor tissues by ultra-high pressure liquid chromatography tandem mass spectrometry. Electron microscopy was used to quantify neurosecretory vesicles within cells derived from PHEO tumor biopsies, NB-PDX and NB cell lines. Chromaffin markers were detected by qPCR, IHC and/or immunoblotting. Plasma levels of metanephrines were comparable between NB and PHEO patients, while catecholamines were 3.5-fold lower in NB vs PHEO affected individuals. However, we observed that intratumoral concentrations of metanephrines and catecholamines measured in NB were several orders of magnitude lower than in PHEO. Cellular and molecular analyses revealed that NB cell lines, primary cells dissociated from human tumor biopsies as well as cells from patient-derived xenograft tumors (NB-PDX) stored a very low amount of intracellular catecholamines, and contained only rare neurosecretory vesicles relative to PHEO cells. In addition, primary NB expressed reduced levels of numerous chromaffin markers, as compared to PHEO/PGL, except catechol O-methyltransferase and monoamine oxidase A. Furthermore, functional assays through induction of chromaffin differentiation of the IMR32 NB cell line with Bt2cAMP led to an increase of neurosecretory vesicles able to secrete catecholamines after KCl or nicotine stimulation. The low amount of neurosecretory vesicles in NB cytoplasm prevents catecholamine storage and lead to their rapid transformation by catechol O-methyltransferase into metanephrines that diffuse in blood. Hence, in contrast to PHEO/PGL, catecholamines are not secreted massively in the blood, which explains why systemic hypertension is not observed in most patients with NB

    The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths

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    We present the Planck Sky Model (PSM), a parametric model for the generation of all-sky, few arcminute resolution maps of sky emission at submillimetre to centimetre wavelengths, in both intensity and polarisation. Several options are implemented to model the cosmic microwave background, Galactic diffuse emission (synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic Sunyaev-Zeldovich signals from clusters of galaxies. Each component is simulated by means of educated interpolations/extrapolations of data sets available at the time of the launch of the Planck mission, complemented by state-of-the-art models of the emission. Distinctive features of the simulations are: spatially varying spectral properties of synchrotron and dust; different spectral parameters for each point source; modeling of the clustering properties of extragalactic sources and of the power spectrum of fluctuations in the cosmic infrared background. The PSM enables the production of random realizations of the sky emission, constrained to match observational data within their uncertainties, and is implemented in a software package that is regularly updated with incoming information from observations. The model is expected to serve as a useful tool for optimizing planned microwave and sub-millimetre surveys and to test data processing and analysis pipelines. It is, in particular, used for the development and validation of data analysis pipelines within the planck collaboration. A version of the software that can be used for simulating the observations for a variety of experiments is made available on a dedicated website.Comment: 35 pages, 31 figure

    High level expression of soluble glycoproteins in the allantoic fluid of embryonated chicken eggs using a Sendai virus minigenome system

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    BACKGROUND: Embryonated chicken eggs have been used since the mid-20th century to grow a wide range of animal viruses to high titers. However, eggs have found so far only limited use in the production of recombinant proteins. We now describe a system, based on a Sendai virus minigenome, to produce large amounts of heterologous viral glycoproteins in the allantoic cavity of embryonated eggs. RESULTS: Soluble forms of human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV) fusion (F) proteins, devoid of their transmembrane and cytoplasmic domains, were produced in allantoic fluids using the Sendai minigenome system. The first step was rescuing in cell cultures Sendai virus minigenomes encoding the proteins of interest, with the help of wild type Sendai virus. The second step was propagating such recombinant defective viruses, together with the helper virus, in the allantoic cavity of chicken embryonated eggs, and passage to optimize protein production. When compared with the production of the same proteins in the culture supernatant of cells infected with vaccinia recombinants, the yield in the allantoic fluid was 5–10 fold higher. Mutant forms of these soluble proteins were easily constructed by site-directed mutagenesis and expressed in eggs using the same approach. CONCLUSION: The simplicity and economy of the Sendai minigenome system, together with the high yield achieved in the allantoic fluid of eggs, makes it an attractive method to express soluble glycoproteins aimed for structural studies

    Equivalent Patrimonial des Droits Ă  Retraite en France : MĂ©thodologie et Mesure dans l'EIR

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    L’équivalent patrimonial des droits Ă  retraite (directs ou dĂ©rivĂ©s) permet d’évaluer la soutenabilitĂ© et la gĂ©nĂ©rositĂ© des rĂ©gimes de retraite. A l’aide des donnĂ©es de l’Echantillon Inter-rĂ©gimes des RetraitĂ©s de 2008, nous proposons une mesure de cet indicateur pour les assurĂ©s Ă  la retraite du systĂšme de retraite français. L’objectif de cet article est de discuter des choix mĂ©thodologiques retenus Ă  chaque Ă©tape de calcul de l’équivalent patrimonial et de souligner les contraintes et les limites spĂ©cifiques Ă  un tel exercice. Les rĂ©sultats obtenus rĂ©vĂšlent que les diffĂ©rences entre les rĂ©gimes de retraite peuvent gĂ©nĂ©rer des engagements d’une ampleur variable envers les assurĂ©s Ă  la retraite. L’analyse de la concentration montre que la distribution de l’équivalent patrimonial des droits directs est plus inĂ©gale entre les assurĂ©s aux rĂ©gimes complĂ©mentaires qu’entre les assurĂ©s des rĂ©gimes de base ou intĂ©grĂ©s (rĂ©gime gĂ©nĂ©ral, SRE-civile par exemple). Les inĂ©galitĂ©s au sein des rĂ©gimes et entre les gĂ©nĂ©rations dans la distribution de l’équivalent patrimonial tendent globalement Ă  diminuer au fil des gĂ©nĂ©rations Ă©tudiĂ©es
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