Cartographie automatisée des zones à hauts risques naturels par superposition de données multivariées : exemple de la commune de Seillans (Var)

Mémoire HS n° 15 - Géologie Alpine Risques naturels dans le Sud-est de la France - Colloque Association des Géologues du Sud-est - Avignon, 19 et 20 octobre 1989Dans le cadre d'une étude financée par l'EPR PACA, nous avons développé une méthode de cartographie des zones soumises à des mouvements du sol, à l'aide de moyens infonnatiques. Nous avons appliqué cette méthode à la commune de Seillans afin d'intégrer cette carte des risques dans le plan d'occupation des sols. Parmi les phénomènes naturels qui contraignent l'utilisation du sol, nous n'avons pris en compte que le phénomène glissement de terrain : il n'est en effet pas encore possible par les méthodes employées de mettre en évidence les zones soumises à des phénomènes de dissolution; nous avons également laissé de coté le risque lié à l'instabilité des falaises et des chutes de blocs. Pour réaliser cette cartographie des zones soumises à des mouvements de sol, nous avons retenu trois facteurs: - nature lithologique des terrains affleurant, - pente topographique et sa valeur en pourcentage - hydrologi

In vitro effects of tyre debris organic extract on the kinetic and morphologic traits of rabbit spermatozoa

[EN] The present study aims at evaluating the effects of the organic extract of tyre debris (TDOE) from tyre wear on the kinetic and morphologic features of rabbit spermatozoa. Rabbit sperm were incubated for 4 h with 0, 5, 10, 50 and 75 ¿g/mL of TDOE. Sperm motility was evaluated by computer-assisted semen analysis. Phosphatidilcholine (PS) externalization (apoptosis) and plasma membrane breakage (necrosis) were assessed using the annexinV/propidium iodide assay. The sperm ultrastructure was observed by scanning (SEM) and transmission electron microscopy (TEM). A relevant decrease in the motility rate, PS externalization, and in plasma membrane breakage of spermatozoa were observed after incubation with TDOE at concentrations higher than 50 ¿g/mL. The most frequent ultrastructural anomalies detected in the analysed specimens were: plasma and/or acrosomal membrane breakage, swollen and disorganized mitochondria, and altered axonemal patterns. Taken together, these results suggest that the organic extract of tyre debris can be toxic to rabbit spermatozoa ¿ affecting their movement and structural integrity ¿ when present in seminal plasma at a concentrations higher than 50 ¿g/mL. Although rabbit sperm has been proven to be a suitable model for testing the in vitro effects of many chemical compounds, including TDOE, the obtained results must be considered preliminary and cannot be extrapolated yet to the in vivo outcomes because of scanty data. The results encourage, however, further research in this field.Supported by the PROLIFE Flagship project, city of Milan, ItalyMoretti, E.; Dal Bosco, A.; Mourvaki, E.; Cardinali, R.; Collodel, G.; Geminiani, M.; Cetta, F.... (2009). In vitro effects of tyre debris organic extract on the kinetic and morphologic traits of rabbit spermatozoa. World Rabbit Science. 17(4):213-220. doi:10.4995/wrs.2009.64621322017

Evidence of Deterministic Components in the Apparent Randomness of GRBs: Clues of a Chaotic Dynamic

Prompt γ-ray emissions from gamma-ray bursts (GRBs) exhibit a vast range of extremely complex temporal structures with a typical variability time-scale significantly short – as fast as milliseconds. This work aims to investigate the apparent randomness of the GRB time profiles making extensive use of nonlinear techniques combining the advanced spectral method of the Singular Spectrum Analysis (SSA) with the classical tools provided by the Chaos Theory. Despite their morphological complexity, we detect evidence of a non stochastic short-term variability during the overall burst duration – seemingly consistent with a chaotic behavior. The phase space portrait of such variability shows the existence of a well-defined strange attractor underlying the erratic prompt emission structures. This scenario can shed new light on the ultra-relativistic processes believed to take place in GRB explosions and usually associated with the birth of a fast-spinning magnetar or accretion of matter onto a newly formed black hole

Late Aptian paleoclimate reconstruction of the Brazilian equatorial margin: inferences from palynology

This study conducted high-resolution paleoclimatic analyses based on the identification of palynological groups of late Aptian age (biozone Sergipea veriverrucata) in the Bragança and Codó formations within the Bragança–Viseu, São Luís, and Parnaíba basins. The analysis comprised 40 palynological samples, with 200 palynomorphs per slide counted when possible. Bioclimatic analysis was mainly supported by the identification of botanical affinities, and ecological and climatic parameters such as the wet/arid trend (Fs/X), Shannon–Wiener diversity, and indicator species analysis (IndVal) were used. Statistical analyses such as principal component and cluster analyses were employed to support the paleoclimatic interpretations. The study recognized 69 genera distributed among the main groups of living plants, including bryophytes, ferns, lycophytes, gymnosperms, and angiosperms. It was possible to attribute botanical affinity in 94.2 % of the taxa, and nine genera occurred in all sections studied: Afropollis, Araucariacites, Callialasporites, Cicatricosisporites, Classopollis, Cyathidites, Deltoidospora, Equisetosporites, and Verrucosisporites, with Classopollis being the most abundant. The stratigraphic distribution of the bioclimatic groups (hydrophytes, hygrophytes, lowland tropical flora, upland flora, and xerophytes) allowed for the identification of climatic phases: pre-evaporitic, evaporitic, and post-evaporitic. In the pre-evaporitic phase, the most significant abundances were between the hygrophytes and upland flora, indicating a certain level of humidity. Xerophytes were the most abundant in all phases, with a conspicuous increase in the evaporitic phase, reflecting an increase in aridity. In the post-evaporitic phase, there was a significant increase in the upland flora with the return of wetter conditions. This study confirmed an increasing humidity trend in the analyzed sections, probably owing to the influence of the Intertropical Convergence Zone that was already operating during the late Aptian.</p

Clustering Microarray Data: Theoretical and Practical Issues

The analysis of microarray data is a widespread functional genomics approach that allows for the monitoring of the expression of thousands of genes at once. The analysis of the great amount of data generated in a microarray experiment requires powerful statistical techniques. One of the first tasks of the analysis of microarray data is to cluster data into biologically meaningful groups according to their expression patterns. In this article, we discuss classical as well as recent clustering techniques for microarray data. We pay particular attention to both theoretical and practical issues and give some general indications that might be useful to practitioners

Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study, we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired; however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV- and HBV-infected patients versus controls. © 2008 The Authors

One-pot sequential 1,2-addition, Pd-catalysed cross-coupling of organolithium reagents with Weinreb amides

An efficient sequential 1,2-addition/cross-coupling of Weinreb amides with two organolithium reagents is reported. This synthetic approach allows access to a wide variety of functionalized ketones in a modular way. The one-pot procedure presented here takes advantage of a kinetically stable tetrahedral Weinreb intermediate during subsequent Pd-catalyzed cross-coupling with the second organolithium reagent leading, within short reaction times and under mild conditions, to the formation of ketones in excellent overall yields

Changes in hepatic and renal glutathione-dependent enzyme activities in rabbits and lambs subchronically tretated with triphenyltin acetate

To gain insight into the biochemical mechanisms of organotin toxicity the effects of oral subchronic exposure (70 d) to triphenyltin acetate (TPTA) on hepatic and renal enzymes involved in glutathione metabolism were investigated in rabbits and lambs. Rabbits were offered a diet fortified with 15, 75 or 150 ppm TPTA, whereas lambs were daily given 1 or 7.5 mg/kg TPTA. On the whole, rabbits were more susceptible than lambs and in both species hepatic enzymes were affected to a greater extent than renal enzymes. In rabbit liver, glutathione S-transferase activity toward 1.2-dichloro-4-nitrobenzene (DCNB) was enhanced at 15 ppm and depressed at 150 ppm TPTA, whereas selenium-dependent glutathione peroxidase (Se-GPX) decreased in a dose-related manner; glyoxalase II (GII) activity increased to the same extent at 15 or 75 ppm TPTA but was unaffected at 150 ppm TPTA. For renal enzyme activities in rabbits, only GPX activity was significantly inhibited at 150 ppm TPTA. The only statistically significant changes in lambs were a fall in both hepatic GST accepting DCNB as substrate at 7.5 mg/kg and Se-GPX at I or 7.5 mg/kg TPTA, and an increase in renal GII activity at 7.5 mg/kg TPTA. These results suggest that depression of important antioxidant enzymes such as GST and GPX are part of the complex mechanism of organotin toxicit

A support for classifying scientific papers in a University Department

This work proposes a procedure for merging the classifications provided by competing lists of journal from different institutions, solving indeterminacies and missing attributions

The active fault system of SW Alps

International audienceHistorical and active seismicity in the south-western Alps (France and Italy) shows the recurrence of relatively high-magnitude earthquakes (M ≥ 5.8), like the one that recently affected the Italian Apennine range (M = 6.3 on the 30th March 2009). However, up-to-date detailed mapping of the active fault network has been poorly established. The evaluation of seismological hazard in particular in the highly populated French and Italian coastal region cannot be done without this. Here, we present a detailed study of the main active fault system, based on geological observations along the south-western flank of the Alpine arc. This N140° right-lateral strike-slip active fault system runs along the edge of the Argentera-Mercantour range and can be followed down to the Mediterranean Sea. It is evidenced by (1) Holocene offsets of glacial geomorphology witnessing ongoing fault activity since 10 ka, (2) widespread recent (10–20 Ma) pseudotachylytes featuring long term activity of the faults, (3) active landslides along the main fault zone, (4) geothermal anomalies (hot springs) emerging in the active faults, (5) ongoing low-magnitude seismic activity and (6) localization of the main historical events. In the light of our investigations, we propose a new tectonic pattern for the active fault system in the south-western Alps