Silicon-on-insulator microring resonators for photonic biosensing applications

Silicon-on-insulator microring resonators have proven to be an excellent platform for label-free nanophotonic biosensors. The high index contrast of the silicon-on-insulator waveguides allows for fabrication of micrometer size sensors. Their small size combined with high sensitivity make them ideal candidates for integration in sensing arrays as a multiplexed DNA detection platform. By chemically modifying the sensor surface, the microrings can provide sequence selective DNA detection. However, the high index contrast also limits the quality of the resonances by introducing an intrinsic mode-splitting by coupling the degenerate resonator modes. This severely deteriorates the quality of the output signal. The quality of the resonances is of utmost importance to determine the performance of the microrings as a biosensor. We will suggest an integrated interferometric approach to give access to the unsplit, high-quality normal modes of the microring resonator

Income Taxation with Frictional Labor Supply

This paper characterizes the optimal labor income taxes in an environment where individual labor supply choices are subject to adjustment frictions. Agents incur a fixed cost of adjusting their hours of work in response to changes in their idiosyncratic wages or their tax rates. This fixed cost can be thought of as the cost of searching for a new job in an economy where hours are constrained within the firm. I derive a formula that characterizes the optimal long-run progressive tax schedule in this economy. Adjustment frictions generate endogenously an extensive margin of labor supply conditional on participation. In addition to the standard intensive margin disincentive effects of taxes, the optimal schedule takes into account their effects on the option value of adjusting hours of work, and therefore depends on several new elasticities and marginal social welfare weights. I then evaluate the quantitative magnitude of these novel theoretical effects and show that for a given intensive margin labor supply elasticity, the optimal long-run tax schedule is less progressive than a frictionless model would predict, because an increase in progressivity raises the dispersion of individual incomes around their desired values. The welfare miscalculations by wrongly assuming a frictionless economy can be large, and are decreasing in the size of the intensive margin labor income elasticity. The insights of this paper apply more broadly to models where fixed costs interact with non-linear policy instruments to yield long-run aggregate effects

Recognition of non-formal and informal learning in OECD countries: an overview of some key issues

We are constantly learning, all of us, everywhere and all the time! While there is nothing new about this observation, the idea of exploiting learning that takes place outside the formal system of initial education and training seems to have emerged on a large scale only recently. Taking advantage of such learning requires it to be visible and therefore recognised. The aim of the paper is to give an overview of key issues involved in recognising non-formal and informal learning, ranging from the legitimacy of the learning activities in terms of the outcomes to be recognised, through the cost of the necessary assessment, and essential elements such as quality assurance, the standards used, the potential benefits and the real obstacles. The findings summarised here are based on a report that describes and analyses practices in the 22 countries that participated actively in an OECD study (2009), with participating countries from the five continents

Income Taxation with Frictional Labor Supply

This paper characterizes the optimal labor income taxes in an environment where individual labor supply choices are subject to adjustment frictions. Agents incur a fixed cost of adjusting their hours of work in response to changes in their idiosyncratic wages or their tax rates. This fixed cost can be thought of as the cost of searching for a new job in an economy where hours are constrained within the firm. I derive a formula that characterizes the optimal long-run progressive tax schedule in this economy. Adjustment frictions generate endogenously an extensive margin of labor supply conditional on participation. In addition to the standard intensive margin disincentive effects of taxes, the optimal schedule takes into account their effects on the option value of adjusting hours of work, and therefore depends on several new elasticities and marginal social welfare weights. I then evaluate the quantitative magnitude of these novel theoretical effects and show that for a given intensive margin labor supply elasticity, the optimal long-run tax schedule is less progressive than a frictionless model would predict, because an increase in progressivity raises the dispersion of individual incomes around their desired values. The welfare miscalculations by wrongly assuming a frictionless economy can be large, and are decreasing in the size of the intensive margin labor income elasticity. The insights of this paper apply more broadly to models where fixed costs interact with non-linear policy instruments to yield long-run aggregate effects

Conseil et orientation professionnelle tout au long de la vie : éléments de synthèse des expériences menées dans l'Union européenne

International audienceCe document de synthèse s'adresse à tous les décideurs, acteurs ou même utilisateurs de conseil en matière d'insertion professionnelle et d'intégration sociale au sens large. Il répond pour partie à tous ceux qui s'interrogent sur ces notions de publics cibles et de forme d'action. Il isole très clairement des domaines inégalement explorés et prend quelque peu à contre pied l'idée selon laquelle l'insertion professionnelle est le seul et unique but. Elle est sans doute centrale mais ne doit pas être le seul objectif au risque de ne jamais y parvenir. Ce document liste un ensemble de solutions intermédiaires expérimentées, ou simplement préconisées, çà et là. Il reste toutefois très en ligne avec les différentes actions de l'Union européenne en faveur de l'emploi. Les lignes qui suivent tentent de dégager les éléments récurrents dans les textes de référence mais aussi des grandes lignes d'analyse et de débats potentiels. Le souci d'en tirer des recommandations concrètes est donc présent dans tout le texte

Silicon photonics biosensing: different packaging platforms and applications

We present two different platforms integrating silicon photonic biosensors. One is based on integration with reaction tubes to be compatible with traditional lab approaches. The other uses through-chip fluidics in order to achieve better mixing of the analyte

Nonlinear Tax Incidence and Optimal Taxation in General Equilibrium

We study the incidence of nonlinear labor income taxes in an economy with a continuum of endogenous wages. We derive in closed form the effects of reforming nonlinearly an arbitrary tax system, by showing that this problem can be formalized as an integral equation. Our tax incidence formulas are valid both when the underlying assignment of skills to tasks is fixed or endogenous. We show qualitatively and quantitatively that contrary to conventional wisdom, if the tax system is initially suboptimal and progressive, the general-equilibrium trickle-down forces may raise the benefits of increasing the marginal tax rates on high incomes. We finally derive a parsimonious characterization of optimal taxes