Deterministic radiative coupling between plasmonic nanoantennas and semiconducting nanowire quantum dots

International audienceWe report on the deterministic coupling between single semiconducting nanowire quantum dots emitting in the visible and plasmonic Au nanoantennas. Both systems are separately carefully characterized through microphotoluminescence and cathodoluminescence. A two-step realignment process using cathodoluminescence allows for electron beam lithography of Au antennas near individual nanowire quantum dots with a precision of 50 nm. A complete set of optical properties are measured before and after antenna fabrication. They evidence both an increase of the NW absorption, and an improvement of the quantum dot emission rate up to a factor two in presence of the antenna

LES POLITIQUES ENVIRONNEMENTALES A L'EPREUVE DE L'INTERCOMMUNALITE : VERS DE NOUVEAUX TERRITOIRES D'ACTION ?

Cette recherche a questionné l'hypothèse généralement admise que l'intercommunalité permet une rationalisation de l'action publique qui engendre " une plus grande efficacité, une plus grande cohérence et une solidarité territoriale renforcée " et ce, dans le domaine des politiques environnementales. En effet, pour conduire une analyse approfondie des effets de l'intercommunalité sur le contenu substantiel des politiques, il était nécessaire de restreindre l'analyse à un champ d'action donné ; compte-tenu de l'importance de l'environnement dans l'action publique des intercommunalités et des compétences de l'équipe répondante tant dans le domaine des politiques environnementales (UMR CITERES) que dans celui de l'intercommunalité (EA LERAD), c'est ce champ qui a été investi. Il a ainsi été proposé, sur la base d'une analyse de politiques environnementales conduites par des intercommunalités sur deux territoires tests (le SCoT du Saumurois et le SCoT de l'Amboisie, du Blérois et du Castelrenaudais (ABC)), de vérifier les effets du développement de l'intercommunalité sur le contenu des politiques menées

From diluted magnetic semiconductors to self-organized nanocolumns of GeMn in Germanium

While achieving high Curie temperatures (above room temperature) in diluted magnetic semiconductors remains a challenge in the case of well controlled homogeneous alloys, several systems characterized by a strongly inhomogeneous incorporation of the magnetic component appear as promising. Incorporation of manganese into germanium drastically alters the growth conditions, and in certain conditions of low temperature Molecular Beam Epitaxy it leads to the formation of well organized nanocolumns of a Mn-rich material, with a crystalline structure in epitaxial relationship with the Mn-poor germanium matrix. A strong interaction between the Mn atoms in these nanocolums is demonstrated by x-ray absorption spectroscopy, giving rise to a ferromagnetic character as observed through magnetometry and x-ray magnetic circular dichroism. Most interesting, intense magneto-transport features are observed on the whole structure, which strongly depend on the magnetic configuration of the nanocolumns.Comment: SPIE Optics & Photonics Symposium, San Diego : \'Etats-Unis d'Am\'erique (2008

Developmental expression of fibrillarin and U3 snRNA in Xenopus laevis

Fibrillarin is one of the protein components that together with U3 snRNA constitute the U3 snRNP, a small nuclear ribonucleoprotein particle involved in ribosomal RNA processing in eucaryotic cells. Using an antifibrillarin antiserum for protein detection and a fibrillarin cDNA and a synthetic oligonucleotide complementary to U3 snRNA as hybridization probes, the expression of these two components has been studied during Xenopus development. Fibrillarin mRNA is accumulated early in oogenesis, like many other messengers, and translated during oocyte growth. Fibrillarin protein is thus progressively accumulated throughout oogenesis to be assembled with U3 snRNA and used for ribosome production in the amplified nucleoli. After fertilization, the amount of U3 snRNA decreases while the maternally accumulated fibrillarin mRNA is maintained and utilized to produce more protein. After the mid-blastula transition, stored fibrillarin is assembled with newly synthesized U3 snRNA and becomes localized in the prenucleolar bodies and reforming nucleoli

Developmental expression of fibrillarin and U3 snRNA in Xenopus laevis

Fibrillarin is one of the protein components that together with U3 snRNA constitute the U3 snRNP, a small nuclear ribonucleoprotein particle involved in ribosomal RNA processing in eucaryotic cells. Using an antifibrillarin antiserum for protein detection and a fibrillarin cDNA and a synthetic oligonucleotide complementary to U3 snRNA as hybridization probes, the expression of these two components has been studied during Xenopus development. Fibrillarin mRNA is accumulated early in oogenesis, like many other messengers, and translated during oocyte growth. Fibrillarin protein is thus progressively accumulated throughout oogenesis to be assembled with U3 snRNA and used for ribosome production in the amplified nucleoli. After fertilization, the amount of U3 snRNA decreases while the maternally accumulated fibrillarin mRNA is maintained and utilized to produce more protein. After the mid-blastula transition, stored fibrillarin is assembled with newly synthesized U3 snRNA and becomes localized in the prenucleolar bodies and reforming nucleoli