Post-magmatic alteration of certain magmatic Ni sulfide ores in Western Australia, the Miitel deposit and the Sarah's Find prospect, produced Ni–As–PGE haloes around massive sulfides. A study of the composition of arsenide grains from these hydrothermal haloes, along with arsenides from various magmatic and hydrothermal mineralized environments in other localities, was conducted in order to compare their composition, and assess their potential use as indicator minerals for exploration vectoring, as well as to gain knowledge on their crystallization history. Concentrations in trace elements such as platinum-group elements (PGEs), Au and other metals was obtained by laser ablation inductively coupled plasma mass spectroscopy analyses. Results show that variations in PGEs and Au compositions can be related to the magmatic vs. hydrothermal origin of the grains; and to their provenance from deposits enriched in either Ni, Au or both. Magmatic NiCoFe sulfarsenides have strongly correlated, high IPGE (Os, Ir, Ru, Rh) contents up to 100 ppm Ir, compared with maximum values in hydrothermal sulfarsenides of ~1 ppm. Gold in hydrothermal sulfarsenides from Au-mineralized ultramafic rocks extends up to 500 ppm, with typical values of 3–30 ppm; similar values are also found in nickeline (also called niccolite). These results suggest that nickel arsenides could potentially be used as indicator minerals for nickel and gold exploration. Trace-element contents of arsenide grains in shear zones could be used to deduce the presence of Ni or Au mineralization upstream in the fluid pathway.

On 24–25 October 2005 a cluster of five haemolytic uraemic syndrome (HUS) cases was reported in southwest France. An investigation was undertaken to identify the outbreak source and implement control measures. Cases were defined as individuals with HUS or diarrhoea with isolation of Escherichia coli O157:H7 in stools or a positive antibody response to E. coli O157 lipopolysaccharide, resident in southwest France with symptom onset after 19 September 2005. Sixty-nine identified patients had symptom onset between 5 October and 3 November 2005, including 17 cases of HUS. One brand of frozen beef burgers produced on 22 August 2005 was consumed by all patients in the week before symptom onset. E. coli O157:H7 strains from patients, patients' burgers and the manufacturing plant were genetically related. This is the largest community-wide outbreak of E. coli O157:H7 in France to date and the first associated with consumption of contaminated frozen beef burgers.

Depuis le début des années 90, EDF a fait des efforts importants en matière d’optimisation de la radioprotection des travailleurs dans les centres nucléaires de production d’électricité (CNPE) ce qui s’est traduit par une forte réduction de la dose individuelle (581 intervenants au dessus de 20 mSv en 1996 ; aucun au dessus de 20 mSv et seulement 17 au dessus de 16 mSv en 2006) et de la dose collective moyenne par tranche (réduction de plus d’un facteur deux en dix ans). EDF souhaite poursuivre ses efforts pour améliorer la radioprotection dans les centrales françaises. Une des voies d’amélioration est l’analyse du retour d’expérience de la pratique des centrales étrangères ayant de très bons résultats dosimétriques ou ayant connu une amélioration récente significative de la dosimétrie. Dans cette perspective, entre 2003 et 2006, le CEPN a organisé pour EDF huit visites d’intercomparaison de l’organisation et des pratiques de radioprotection dans des centrales nucléaires à l’étranger. Lors de chaque visite, une équipe de quatre personnes, composée de deux représentants d’EDF et de deux représentants du CEPN, se rend sur place pendant une semaine et rencontre des représentants de la plupart des services impliqués dans la mise en œuvre des thèmes retenus. Plusieurs bonnes pratiques de radioprotection ont été mises en avant lors de ces visites : une bonne intégration de la radioprotection dans le management de la centrale ; les efforts de réduction du terme source ; l’impact fondamental de la réduction des volumes de travail exposé par l’optimisation des programmes de maintenance et par des modifications entraînant une réduction de la nécessité de maintenance ; une radioprotection de proximité expérimentée ; de nouveaux outils au service de la radioprotection du 21e siècle, en particulier la télésurveillance et la télédosimétrie.

The involvement of local stakeholders in the decision-making process regarding health, safety and environmental issues is developing in many countries. As far as the management of effluent discharges from nuclear installations in France is concerned, members of Local Commission of Information, including elected people and NGOs, are playing an increasing role in that respect. To deepen the understanding of these risk governance processes, a working group of experts from different institutions was set up in 2000 by the Institute of Radiation Protection and Nuclear Safety (IRSN). Several case studies concerning the involvement of stakeholders were performed, among them: the dialogue process around the discharges of the COGEMA La Hague reprocessing plant, the role of the local liaison committees of the Fessenheim and Gravelines nuclear power plants. Four main elements, contributing to the social trust, emerge from this analysis: 1) the social dynamics of the consultation process, notably with the emergence of “new" stakeholders such as elected people and NGOs; 2) the readability of the plant follow-up from the point of view of local stakeholders and their involvement in the decision process (the relay role of these “new" stakeholders); 3) the contribution of the institutional and pluralist expertise to the social trust (broadening of the range of values taken into account); 4) the issue of the local justification of the plant in the prospect of the sustainable development (no risk being acceptable without counter-parts). This paper addresses these different issues on the basis of the case studies in the perspective of examining the radiological risk governance process.

AlGaN is an important material for the realization of nitride heterostructures, involved in most device designs. We have studied the growth of this alloy using low pressure MOVPE (76 Torr), and using triethyl-gallium (TEGa), trimethyl-aluminum (TMA1) and ammonia (NH3) as precursors. First the solid -gas aluminum segregation was studied in order to calibrate the incorporation of Al in the solid phase. We found that aluminum is more readily incorporated than gallium in the solid, leading to an apparent Al segregation coefficient greater than unity. A simple kinetic model is used to fit the experimental data. Scanning electron microscopy has been used to investigate the morphology of the samples through the whole range of Al content (x = 0 to 1), and we observe a clear evolution of the surface features versus aluminum concentration: at low Al contents, small (below 1 pm) hexagonal holes are observed while at high Al, acicular features are observed, with a sudden transition between those morphologies around x = 0.5. Transmission electron microscopy was used to analyze the crystalline structure of these samples. Finally, the samples were studied by low temperature (2K) reflectivity and Raman spectroscopy. We report the evolution of the optical quality of samples (x < 0.4) versus Al content, as evaluated from the broadening of the observed excitonic transitions in the 2K reflectivity.

The problem of residual strain in GaN epilayers is currently the attention of many studies, since it affects the optical and electrical properties of the epilayers. In order to discuss the origin of this residual strain, we have grown a series of GaN epilayers onto AlN buffer layers, sapphire (0001) being used as substrate. The buffer layer is usually deposited in an amorphous state and is recrystallized by a thermal annealing. Here we have made a systematic study of the buffer recrystallization by changing the annealing temperature and the annealing time. The surface morphology is probed using Atomic Force Microscopy (AFM). The lattice parameter c is carried out from accurate x-ray diffraction measurements. The GaN layers were studied by low temperature photoluminescence and reflectivity. The amount of residual strain is calibrated from the position of the A exciton and the optical quality of the layers is assessed from the photoluminescence linewidths. The longer the annealing time the better the strain relaxation in AlN buffer layers and the higher the lattice mismatch with GaN overlayers.

Group theory states that the spectroscopy of excitons in GaN epilayers grown with biaxial stress on M Plane (10–10)-oriented substrates is strongly anisotropie in the growth plane, in contrast to the situation if growth occurs on conventional C plane substrates. In addition, we predict existence of nine radiative transitions instead of five, three for each family of A, B, and C excitons. We calculate the in-plane anisotropy and show that, due to the crossed configuration of the wurtzite crystal field and the built-in strain one, the A exciton is significantly coupled to the electromagnetic field in π polarization (E//c).

The effects of children's exposure to parental alcoholism was assessed using records from an existing prospective 40-year longitudinal study of working-class families: 176 men who had grown up with an alcoholic parent or parents were compared with 230 men without such exposure. Degree of exposure to alcoholism in the childhood family environment was highly correlated in later life with alcohol use, alcoholism, time in jail, sociopathy, and death, but not with increased rates of unemployment, poor physical health, or measures of adult ego functioning. Most of the impairments observed occurred in those subjects who actually developed alcoholism. Exposure to alcoholism in the family environment and family history of alcoholism independently contributed to the later development of alcoholism.