Clusters et networks en Irlande : un modèle de développement économique ?

Dans une économie de plus en plus globalisée, l’importance de liens et de relations plus étroits entre les différents acteurs économiques est apparue de plus en plus clairement. Les regroupements et les alliances sont devenus les outils incontournables de la compétitivité tant pour les entreprises que pour les institutions traditionnellement supposées relever de la sphère publique, comme l’enseignement et la recherche, désormais forcées, en raison de déficits publics croissants, de trouver d’autres sources de revenus et de se lancer dans la compétition. C’est pourquoi se sont formés des grappes (clusters) et des réseaux (networks) de diverses natures, caractérisés par la concentration des moyens et la complémentarité, à l’échelle internationale, nationale ou régionale, impliquant des acteurs publics ou privés, ou des partenariats public-privé. Le Tigre Celtique n’a pas été épargné par ce phénomène économique, et le développement économique remarquable de l’Irlande s’est appuyé en partie sur l’éclosion de ces noyaux et réseaux dans divers secteurs de la vie économique. Cependant, l’émergence et la multiplication de ces structures pose nombre de questions sur leur mise en œuvre et leurs effets, et sur le fossé éventuel entre théorie et pratique.In an increasingly globalised economy, the importance of tighter links and relationships between the various economic stakeholders has become more and more obvious. Connections and alliances have become the inescapable instruments of competitiveness both for enterprises and for institutions traditionally related to the public sector, like the higher education and research institutions which, as a result of constantly inflating public deficits, have had to find new sources of funding and become competitive too. This is the reason why a large variety of regional, national and international clusters and networks have taken shape, all characterised by the concentration of means and by complementarity, involving public or private stakeholders or public-private partnerships. The Celtic Tiger has not been spared by this economic phenomenon and the remarkable economic development of Ireland has partly depended on the development of such clusters and networks in various economic sectors. However, the emergence and the multiplication of these structures call the issues of their implementation and effects and of the possible gap between theory and practice in question

Efficient fiber-optical interface for nanophotonic devices

We demonstrate a method for efficient coupling of guided light from a single mode optical fiber to nanophotonic devices. Our approach makes use of single-sided conical tapered optical fibers that are evanescently coupled over the last ~10 um to a nanophotonic waveguide. By means of adiabatic mode transfer using a properly chosen taper, single-mode fiber-waveguide coupling efficiencies as high as 97(1)% are achieved. Efficient coupling is obtained for a wide range of device geometries which are either singly-clamped on a chip or attached to the fiber, demonstrating a promising approach for integrated nanophotonic circuits, quantum optical and nanoscale sensing applications.Comment: 7 pages, 4 figures, includes supplementary informatio

"Io ho voluto scrivere tutto quel che me passa per la mente". Le lettere di Giulia Gonzaga

The almost entirely unpublished collection of Giulia Gonzaga’s letters tells not only the story of one woman’s private life but, as is often the case with female correspondence, interweaves personal, public and institutional themes. These are ‘domestic' letters in which concerns about the household, children, nephews and nieces, are entwined with discussions about the difficulties of government, the petty personal ambitions of the power-hungry, and the defence of the family blood line. A gentlewoman who was perhaps better known for her beauty than her culture, Giulia Gonzaga is a lively witness of a society at the centre of an unprecedented political and religious crisis. The hundreds of mostly handwritten letters chronicle diverse moments from the history of sixteenth-century Italy, sometimes dealing at length with political and religious affairs from around 1520 to 1565. Giulia Gonzaga was at the centre of a complicated aristocratic order whose imperial ambitions and mode of governance sometimes came into direct conflict with the papacy, which had its own designs on power. Nobles such as Giulia Gonzaga were therefore both tolerant of and curious about new religious thinking. Together with her “spiritual” friends and supporters of ecclesiastic reform, she contributed to the effort to shift the religious policy of the Church of Rome. She gives voice to dissent and fears, and laments the defeats that the reformists suffered at the hands of the Roman Inquisition.

Quantitative GIS-based analysis of archaeological data of the archaic state of Tell Mardikh/Ebla (3rdmillennium BC): The Big-DEA project

The paper provides an overview on Big-DEA, a multidisciplinary project aimed at developing a comprehensive multi-level explanatory model for the development of an archaic State in the ancient Near East, using the exceptional case of Tell Mardikh, ancient Ebla (Syria), during the second half of the 3rd millennium. The project's goal is the reconstruction of the archaic state organization through an integrated analysis of archaeological and epigraphic data. The interaction between humanities and hard sciences is adopted in order to build a multi-tier explanatory model regarding the territory under the control of the Ebla kingdom, considering anthropic and environmental data deriving from excavations, survey and textual sources. The way to managing and study such a large Big Data archive, which includes different datasets, is itself the main challenge of the project: the creation of a dedicated relational database management system (RDBMS) functional to the implementation of the available GIS platform and the development of an appropriate simulation framework

Quantum nonlinear optics using cold Rydberg atoms

Although photons do no a ect each other in vacuum, interactions between individual photons could enable a wide variety of scienti c and engineering applications. Here we report on the creation of a quantum nonlinear medium with large photon-photon interactions at the single photon level. Our approach relies on Electromagnetically Induced Transparency (EIT) techniques, in which individual photons are coherently mapped onto strongly interacting Rydberg atoms. Under EIT conditions, photons traveling in the medium are best described as part-matter part-light quantum particles, called polaritons, which experience long-range interactions through the Rydberg blockade. In particular, we demonstrate coherent photon-photon interactions, akin to those associated with conventional massive particles, paving the way for novel photonics states and quantum simulation with light

Introduction

Dans un article intitulé « De quoi la crise est-elle le nom », le journaliste Georges Streiff écrivait en 2013 « La crise est partout. Le mot est utilisé jusqu’à l’overdose. Curieusement, plus on en parle, moins on dit de quoi il retourne. C’est LA crise. Comme une rengaine anxiogène qui se suffirait à elle-même. » Dans La crise sans fin. Essai sur l’expérience moderne du temps, Myriam Revault d’Allonnes explique : On ne parle plus aujourd'hui d'une crise succédant à d'autres crises – et prél..

Quantum nonlinear optics using cold atomic ensembles

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 219-232).The fundamental properties of light derive from its constituent particles, photons, which are massless and do no interact with each other. The realization of interactions between photons could enable a wide variety of scientific and engineering applications. In particular, coherent interactions would open the path for the simulation of quantum systems with light. Photon-photon interactions can be mediated by matter, in our case cold atomic ensembles, which provide a nonlinear medium. In conventional nonlinear media, the nonlinearities are negligibly weak at intensities corresponding to single photons and nonlinear optics at the few-photon level is a long-standing goal of optical and quantum science. In this thesis, we report on two different experimental approaches to create optical media with giant nonlinearities. Both approaches rely on Electromagnetically Induced Transparency, in which photons traveling in the medium are best described as part-matter part-light quantum particles, called polaritons. In our first approach, we achieve low-light nonlinearities by loading ensembles of cold atoms in a hollow-core photonic crystal fiber to enhance the polariton-photon interactions. In our second approach, the photons are coupled to strongly interacting Rydberg atoms, which mediate large interactions between single quanta of light. Moreover, the intrinsic nature of these interactions can be tailored to take on a coherent dispersive form.by Thibault Peyronel.Ph.D