A 2D nanosphere array for atomic spectroscopy

We are interested in the spectroscopic behaviour of a gas confined in a micrometric or even nanometric volume. Such a situation could be encountered by the filling-up of a porous medium, such as a photonic crystal, with an atomic gas. Here, we discuss the first step of this program, with the generation and characterization of a self-organized 2D film of nanospheres of silica. We show that an optical characterization by laser light diffraction permits to extract some information on the array structure and represents an interesting complement to electron microscopy.Comment: accept\'e pour publication \`a Annales de Physique- proceedings of COLOQ1

Europhiles or Eurosceptics? Comparing the European policies of the Labour Party and the Liberal Democrats

The Labour Party and the Liberal Democrats are often portrayed as Britain’s pro- European parties. Indeed, both parties express a keen interest in keeping Britain in the European Union (EU) and in promoting a constructive engagement with other member states. Yet, to what extent can the two parties be characterized as Europhiles? In this article, we develop Taggart and Szczerbiak’s (2008) concept of hard and soft Euroscepticism, extend it to Europhile party positions, and apply it to Labour and the Liberal Democrats’ recent European policies. For this purpose, we analyze manifestos and party leaders’ key speeches on the EU. We find, overall, that the Labour Party and the Liberal Democrats are ‘soft’ Europhiles whose discourses have focused on EU reform. Yet, whilst their EU policies are very similar, their EU strategies differ: the Labour leadership have generally tried to contain the salience of EU issues, whereas the Liberal Democrats have followed a more offensive EU strategy after 2014. This can best be explained through electoral incentives and internal dynamics

Host cell invasion by apicomplexan parasites: the junction conundrum

No abstract available

Has the Financial Crisis Undermined Credit Reallocation in the United Kingdom?

The global financial crisis and its aftermath heightened awareness of the role of credit frictions in affecting aggregate economic performance. An important question is whether capital is being allocated to its most productive uses. This paper examines the process through which credit is reallocated across surviving UK businesses over 2004-2012 using the methodology developed by Davis and Haltiwanger (1992) for the analysis of job reallocation. We find that credit reallocation among survivors is intense, and that it primarily occurs across firms similar in size, industry, or location. The results suggest that the aftermath of the global financial crisis has been characterized by persistently increased levels of credit reallocation. However, the evolution of the intensity of credit reallocation after the crisis varies greatly by firm size as measured by sales, with firms in the middle of the distribution driving the overall elevated levels of reallocation in the post-crisis period. When focusing on the sub-sample of larger firms we use to examine the efficiency of the reallocation process, reallocation flows appear to have decreased to levels lower than pre-crisis after a sharp increase in 2007-2008. In terms of efficiency developments, we find that the productivity slowdown of 2008-2009 does not coincide with a deterioration of allocative efficiency along three crucial dimensions of firm performance, namely TFP, labour productivity, and default risk. However, the credit crunch of 2008-2009 coincides with a slowdown of year-on-year efficiency improvements, which persists until the end of the sample period. This raises the prospect that the financial crisis might have undermined the ability of lenders to channel credit to its most productive uses

Resonant infiltration of an opal: reflection lineshape and contribution from in-depth regions

We analyze the resonant variation of the optical reflection on an infiltrated artificial opal made of transparent nanospheres. The resonant infiltration is considered as a perturbation in the frame of a previously described one-dimensional model based upon a stratified effective index. We show that for a thin slice of resonant medium, the resonant response oscillates with the position of this slice. We derive that for adequate conditions of incidence angle, this spatially oscillating behavior matches the geometrical periodicity of the opal, and hence the related density of resonant infiltration. Close to these matching conditions, the resonant response of the global infiltration varies sharply in amplitude and shape with the incidence angle and polarization. The corresponding resonant reflection originates from a rather deep infiltration, up to several wavelengths or layers of spheres. Finally, we discuss the relationship between the present predictions and our previous observations on an opal infiltrated with a resonant vapor.Comment: to appear in J Chem Phy

Using effective medium theories to design tailored nanocomposite materials for optical systems

Modern optical systems are subject to very restrictive performance, size and cost requirements. Especially in portable systems size often is the most important factor, which necessitates elaborate designs to achieve the desired specifications. However, current designs already operate very close to the physical limits and further progress is difficult to achieve by changing only the complexity of the design. Another way of improving the performance is to tailor the optical properties of materials specifically to the application at hand. A class of novel, customizable materials that enables the tailoring of the optical properties, and promises to overcome many of the intrinsic disadvantages of polymers, are nanocomposites. However, despite considerable past research efforts, these types of materials are largely underutilized in optical systems. To shed light into this issue we, in this paper, discuss how nanocomposites can be modeled using effective medium theories. In the second part, we then investigate the fundamental requirements that have to be fulfilled to make nanocomposites suitable for optical applications, and show that it is indeed possible to fabricate such a material using existing methods. Furthermore, we show how nanocomposites can be used to tailor the refractive index and dispersion properties towards specific applications.Comment: This is a draft manuscript of a paper published in Proc. SPIE (Proceedings Volume 10745, Current Developments in Lens Design and Optical Engineering XIX, Event: SPIE Optical Engineering + Applications, 2018

Le médecin du travail face au harcèlement moral au travail : constats et prespectives

peer reviewedL'article de D. Faulx et C. Geuzaine, paru dans le numéro 3-2000 de cette revue, aborde l'étendue du phénomène du harcèlement moral ainsi que les aspects juridiques de la définition, la description du processus, ses conséquences médicales et les facteurs de risque. Dans la suite de cette étude, nous présentons ici les résultats d'une enquête menée auprès des médecins du travail, en tant que témoins et intervenants privilégiés dans le domaine du harcèlement. Cette enquête vise à apporter des informations descriptives originales concernant les attitudes, les opinions et représentations des médecins du travail par rapport au phénomène de harcèlement moral. En outre, elle est l'occasion de tester une série d'hypothèses sur les facteurs pouvant influencer l'attitude des médecins du travail vis-à-vis du harcèlement moral