This work presents the synthesis of minerals with a layered structure in supercritical water/ethanol mixtures to decrease the critical coordinates of the solvent regarding water. Depending on the water/ethanol ratio of the solvent, we obtained three different minerals adopting an octahedral brucitic sheet: (1) without a Si-tetrahedral sheet (O); (2) associated with one Si-tetrahedral sheet (T-O); or (3) intercalated between two Si-tetrahedral sheets (T-O-T). We have thus shown that ethanol in a supercritical water/ethanol mixture changes the solubility of silicon with a direct consequence on the formation of the tetrahedral silicon sheets and thus makes it possible to control the structure of the synthesized layered material.

The Polar Large Telescope (PLT) project is primarily aimed at undertaking large, wide band synoptic astronomical surveys in the infrared in order to provide critical data to the forthcoming generation of observational facilities such as ALMA, JWST, LSST and the E–ELT, and to complement the observations obtained with them. Sensitive thermal IR surveys beyond 2.3 μm cannot be carried out from any existing ground based observatory and the Antarctic Plateau is the only place on the ground where it can be envisaged, thanks to its unique atmospheric and environmental properties, such as the turbulence profile (image quality), the low opacity and the reduced thermal background emission of the sky. These unique conditions enable high angular resolution wide field surveys in the near thermal infrared (2.3–5 μm). This spectral range is particularly well suited to tackling key astrophysical questions such as: i) investigating the nature of the distant universe, the first generation of stars and the latest stages of stellar evolution, ii) understanding transient phenomena such as gamma ray-bursts and Type Ia supernovae, iii) increasing our knowledge of extra-solar planets. Further instruments may broaden the expected science outcomes of such a 2–4 m class telescope especially for the characterization of galaxies at very large distance to provide new clues in the mysteries of dark matter and energy. Efforts will be made to merge this project with other comparable projects within an international consortium.

The simulation of simultaneous diffusion and precipitation of a chemical element during internal oxidation phenomena is presented here, from X-FEM method. This technique seems to be really appropriate when solubility products are very low, or even almost null. In this case, a precipitation front appears and should be properly represented by the numerical simulation. The X-FEM method is then of strong interest, since it allows to know precisely the position of the front all the time of simulation, without remeshing.

The aim of this article is to describe the evolution of the Italian regional party systems 25 years after the establishment of 15 Ordinary Statute regions and five years after the implementation of a major Constitutional reform increasing the powers of the regions and the visibility of regional political actors. The theoretical point of departure of the article is the second order election model originally applied to European elections to highlight their dependence on the national political level. The article begins by showing that this model has been applicable for regional elections only since the mid-1990s, a finding that goes against the conventional wisdom. The article then explains the structure of regional political competition through the analysis of two phenomena, fragmentation and differentiation, and the way they are correlated, stressing the changing pattern of competition before and after the breakdown of the First Republic.

Levels of nickel and vanadium, trace metals found in high concentration in the oil spilled from the “Erika” tanker off Brittany (France) in December 1999 (41 ± 1 and 87 ± 3 mg kg−1 respectively), have been monitored over a one-year period following this accidental event in several benthic invertebrates. Ni and V in mussels (Mytilus edulis) and oysters (Crassostrea gigas) soft tissues were analysed twice a month by graphite furnace atomic absorption spectrometry and a scallop (Pecten maximus) shell daily growth bands were sampled every three bands by laser ablation and analysed by ICP-MS for these two contaminants. Survey data for mollusc tissues were compared with reference data arising from the national monitoring database. Ni concentrations in dried tissues, comparable with reference data (1.8 ± 0.9 µg g−1 in mussels and 1.2 ± 0.5 µg g−1 in oysters) do not show any additional input during the whole period. Conversely, a sharp increase in vanadium concentrations (up to 4.6 and 3.2 µg g−1 for mussels and oysters respectively) is observed around May 2000, i.e. 5 months after the wreck, compared with the monitoring data (1.4 ± 0.6 µg g−1 in mussels and 1.3 ± 0.6 µg g−1 in oysters). Furthermore, no Ni peak is detectable in the time profiles of scallop shell growth bands where a V peak is observed also in May 2000. This study shows that although a “mussel-watch-type” network, based on the monitoring of vanadium concentration in mollusc tissues, is able to identify contamination due to oil spills, similar information might be obtained a posteriori by analysing daily growth bands of scallop shells.

Nodulated legume trees comprised 43% of the stand basal area in the low, most frequently flooded microsites, and 23% in higher, drier microsites in a tropical freshwater swamp forest in French Guiana. Dinitrogen fixation in Pterocarpus officinalis, Hydrochorea corymbosa and Inga pilosula was confirmed by acetylene reduction assay (ARA), presence of leghaemoglobin in nodules and the 15N natural abundance method. The results for Zygia cataractae were inconclusive but suggested N2 fixation in drier microsites. Nodulated Inga disticha had a 15N-to-14N ratio similar to non-N2-fixing trees, but ARA indicated nitrogenase activity and leghaemoglobin was present in nodules. All bacterial strains were identified as Bradyrhizobium spp. according to the partial 16S rDNA sequences, and they were infective in vitro in the model species Macroptilium atropurpureum. About 35-50% of N in the leaves of P. officinalis, H. corymbosa and I. pilosula was fixed from the atmosphere. Dinitrogen fixation was estimated to contribute at least 8-13% and 17-28% to whole-canopy N in high and low microsites, respectively. Symbiotic N2 fixation appears to provide both a competitive advantage to legume trees under N-limited, flooded conditions and an important N input to neotropical freshwater swamp forests.

French mollusc production is based mainly on the Pacific cupped oyster, Crassostrea gigas. Since 1991, annual mass mortality of juveniles has been reported during summer months. These recurring episodes concern professionals who fear that like Portugese oyster, C. angulata, C. gigas could in turn disappear following one of these epizooties. Previously, bacteriological analysis of moribund oyster juveniles yielded an isolate of a Vibrio splendidus biovar II strain, named TNEMF6. This isolate was demonstrated to be pathogenic to Crassostrea gigas spat by experimental challenge. To study the association between summer oyster mortality and presence of TNEMF6 cluster strains, Vibrionaceae fauna were isolated from infected spat along the French Atlantic coast between 1997-1998. Strains related to V. splendidus biovar II were selected. Comparison with TNEMF6 was performed by classical biochemical tests and polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) of SSU rDNA, rpoD, and gyrB genes. Genomic similarities were confirmed by DNA/DNA hybridization. Only one strain out of 14, TNNIII7, was found to be closely related to the pathogenic bacteria. Neither the phenotypic nor the genotypic markers used in this study were able to distinguish pathogenic from non-pathogenic strains of the widespread V. splendidus. However, future genetic comparisons of TNEMF6 and TNNIII7 is likely to reveal genes involved in pathogenicity.

The phylogenetic relationships of several smut fungi parasitic on dicotyledons were analysed. Parsimony analysis was performed based on the sequences of the ITS regions of the rDNA genes. Three genera were considered: Microbotryum, Sphacelotheca and Ustilago. The cladogram showed a dichotomy: the species of Microbotryum and Ustilago parasitic on dicotyledons (dicot Ustilago) were found to be divided into two independent taxa among the Microbotryaceae. A divergent mechanism of evolution of the species of each of these two clades with their respective hosts could be involved in this dichotomy. According to our results, Microbotryum appears monophyletic and restricted to the anthericolous smuts on Caryophyllaceae. However, no morphological characters have yet been found to support this distinction, and we refute the denomination Bauhinus as defined by Moore to describe the group of ‘dicot Ustilago’ as it leads to controversial determinations. Sphacelotheca belongs to Microbotryales, but could not be synonymised with Microbotryum as S. polygoni-persicariae is in an independent clade. Lastly, U. duriaeana is independent of the ‘dicot Ustilago’ clade; the position of this species among Microbotryales is still uncertain.