718 research outputs found

    Morphological analysis of stylolites for paleostress estimation in limestones surrounding the Andra Underground Research Laboratory site

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    We develop and test a methodology to infer paleostress from the morphology of stylolites within borehole cores. This non-destructive method is based on the analysis of the stylolite trace along the outer cylindrical surface of the cores. It relies on an automatic digitization of high-resolution photographs and on the spatial Fourier spectrum analysis of the stylolite traces. We test and show, on both synthetic and natural examples, that the information from this outer cylindrical surface is equivalent to the one obtained from the destructive planar sections traditionally used. The assessment of paleostress from the stylolite morphology analysis is made using a recent theoretical model, which links the morphological properties to the physical processes acting during stylolite evolution. This model shows that two scaling regimes are to be expected for the stylolite height power spectrum, separated by a cross-over length that depends on the magnitude of the paleostress during formation. We develop a non linear fit method to automatically extract the cross-over lengths from the digitized stylolite profiles. Results on cores from boreholes drilled in the surroundings of the Andra Underground Research Laboratory located at Bure, France, show that different groups of sedimentary stylolites can be distinguished, and correspond to different estimated vertical paleostress values. For the Oxfordian formation, one group of stylolites indicate a paleostress of around 10 MPa, while another group yields 15 MPa. For the Dogger formation, two stylolites indicate a paleostress of around 10 MPa, while others appear to have stopped growing at paleostresses between 30 and 22 MPa, starting at an erosion phase that initiated in the late Cretaceous and continues today. This method has a high potential for further applications on reservoirs or other geological contexts where stylolites are present.Comment: International Journal of Rock Mechanics and Mining Sciences (2013) online firs

    Prediction of thermal radiative properties (300–1000 K) of La2NiO4+δ ceramics.

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    A multiscale numerical model is developed to predict the thermal radiative properties (TRP) of rough La2NiO4+δ coatings. The model integrates intrinsic and extrinsic contributions related to the chemical composition and the texture, respectively. High-temperature infrared reflectivity and thermogravimetric measurements on a La2NiO4+δ single crystal make it possible to understand the role of the excess oxygen in the intrinsic TRP. We show that dense ceramics with thicknesses higher than 4 μm are optically thick, and that one can adjust the surface roughness parameters to predict their TRP

    Expansive evolution of the TREHALOSE-6-PHOSPHATE PHOSPHATASE gene family in Arabidopsis

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    Trehalose is a nonreducing sugar used as a reserve carbohydrate and stress protectant in a variety of organisms. While higher plants typically do not accumulate high levels of trehalose, they encode large families of putative trehalose biosynthesis genes. Trehalose biosynthesis in plants involves a two-step reaction in which trehalose-6-phosphate (T6P) is synthesized from UDPglucose and glucose-6-phosphate (catalyzed by T6P synthase [TPS]), and subsequently dephosphorylated to produce the disaccharide trehalose (catalyzed by T6P phosphatase [TPP]). In Arabidopsis (Arabidopsis thaliana), 11 genes encode proteins with both TPS- and TPP-like domains but only one of these (AtTPS1) appears to be an active (TPS) enzyme. In addition, plants contain a large family of smaller proteins with a conserved TPP domain. Here, we present an in-depth analysis of the 10 TPP genes and gene products in Arabidopsis (TPPA-TPPJ). Collinearity analysis revealed that all of these genes originate from whole-genome duplication events. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that all encode active TPP enzymes with an essential role for some conserved residues in the catalytic domain. These results suggest that the TPP genes function in the regulation of T6P levels, with T6P emerging as a novel key regulator of growth and development in higher plants. Extensive gene expression analyses using a complete set of promoter-beta-glucuronidase/green fluorescent protein reporter lines further uncovered cell- and tissue-specific expression patterns, conferring spatiotemporal control of trehalose metabolism. Consistently, phenotypic characterization of knockdown and overexpression lines of a single TPP, AtTPPG, points to unique properties of individual TPPs in Arabidopsis, and underlines the intimate connection between trehalose metabolism and abscisic acid signaling

    Testosterone Hormone Replacement Therapy: State-of-the-Art and Emerging Technologies

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    In the human male, testosterone is the major circulating androgen. The clinical effects of androgen are numerous, and testosterone deficiency is associated with a number of clinical abnormalities. At present, a variety of preparations containing testosterone is available for the treatment of androgen deficiency. Ideally, those treatments have to produce and maintain physiologic serum concentrations of the hormone. This article reviews the current existing testosterone dosage forms on the market with their advantages and drawbacks and examines new and emerging technology developments concerning this therapy. In particular, the latest innovations in transdermal delivery are explore

    Modeling the growth of stylolites in sedimentary rocks

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    [1] Stylolites are ubiquitous pressure solution seams found in sedimentary rocks. Their morphology is shown to follow two self-affine regimes. Analyzing the scaling properties of their height over their average direction shows that (1) at small scale, they are self-affine surfaces with a Hurst exponent around 1, and (2) at large scale, they follow another self-affine scaling with Hurst exponent around 0.5. In the present paper, we show theoretically the influence of the main principal stress and the local geometry of the stylolitic interface on the dissolution reaction rate. We compute how it is affected by the deviation between the principal stress axis and the local interface between the rock and the soft material in the stylolite. The free energy entering in the dissolution reaction kinetics is expressed from the surface energy term and via integration from the stress perturbations due to these local misalignments. The resulting model shows the interface evolution at different stress conditions. In the stylolitic case, i.e., when the main principal stress is normal to the interface, two different stabilizing terms dominate at small and large scales which are linked respectively to the surface energy and to the elastic interactions. Integrating the presence of small-scale heterogeneities related to the rock properties of the grains in the model leads to the formulation of a Langevin equation predicting the dynamic evolution of the surface. This equation leads to saturated surfaces obeying the two observed scaling laws. Analytical and numerical analysis of this surface evolution model shows that the crossover length separating both scaling regimes depends directly on the applied far-field stress magnitude. This method gives the basis for the development of a paleostress magnitude marker. We apply the computation of this marker, i.e., the morphological analysis, on a stylolite found in the Dogger limestone layer located in the neighborhood of the ANDRA Underground Research Laboratory at Bure (eastern France). The results are consistent with the two scaling regimes expected, and the practical determination of the major principal paleostress, from the estimation of a crossover length, is illustrated on this example

    The Role Of The Informal Sector In Income Generation In Madagascar: The Case Of The Fisheries Sector In The Urban District Of Toliara

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    The purpose of our article is to analyse the informal sector in Madagascar, in order to understand whether it is really a source of income. To do this, we carried out a representative survey of the fishing industry in the urban district of Toliara. The fishing industry has gradually taken its place in the overall economic organisation, and has now become an element of balance and a factor in social stability, and the basis of a territorial dynamic. On a national scale, it accounts for 7 per cent of gross domestic product, provides around 1.5 million direct and indirect jobs, and accounts for 6.6 per cent of exports, making it a fundamental sector of the economy. The main objective of this article is to provide, through various theoretical and empirical tests and analyses, some answers as to the real contribution of the informal sector to the financial integration of fishing households, in Madagascar in general and in the Urban Commune of Toliara in particular. The results of research among a sample of 250 fishermen in this capital of the Atsimo-Andrefana region confirmed that the informal sector offers stable financial resources

    Genomic analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared to <1% of B. cinerea. The arsenal of genes associated with necrotrophic processes is similar between the species, including genes involved in plant cell wall degradation and oxalic acid production. Analysis of secondary metabolism gene clusters revealed an expansion in number and diversity of B. cinerea–specific secondary metabolites relative to S. sclerotiorum. The potential diversity in secondary metabolism might be involved in adaptation to specific ecological niches. Comparative genome analysis revealed the basis of differing sexual mating compatibility systems between S. sclerotiorum and B. cinerea. The organization of the mating-type loci differs, and their structures provide evidence for the evolution of heterothallism from homothallism. These data shed light on the evolutionary and mechanistic bases of the genetically complex traits of necrotrophic pathogenicity and sexual mating. This resource should facilitate the functional studies designed to better understand what makes these fungi such successful and persistent pathogens of agronomic crops.Fil: Ten Have, Arjen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Amselem, Joelle. Institut National de la Recherche Agronomique; FranciaFil: Cuomo, Christina A.. Broad Institute of MIT and Harvard; Estados UnidosFil: Jan, A. L. van Kan. Wageningen University; Países BajosFil: Viaud, Muriel. Institut National de la Recherche Agronomique; FranciaFil: Benito, Ernesto P.. Universidad de Salamanca; EspañaFil: Couloux, Arnaud. Centre National de Séquençage. Genoscope; FranciaFil: Coutinho, Pedro M.. Centre National de la Recherche Scientifique; FranciaFil: Vries, Ronald P. de. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajos. Fungal Biodiversity Centre; Países BajosFil: Dyer, Paul S.. The University Of Nottingham; Reino UnidoFil: Fillinger, Sabine. Institut National de la Recherche Agronomique; FranciaFil: Fournier, Elisabeth. Institut National de la Recherche Agronomique; Francia. Centre de coopération internationale en recherche agronomique pour le développement; FranciaFil: Gout, Lilian. Institut National de la Recherche Agronomique; FranciaFil: Hahn, Matthias. University Of Kaiserlautern; AlemaniaFil: Kohn, Linda. University Of Toronto; CanadáFil: Lapalu, Nicolas. Institut National de la Recherche Agronomique; FranciaFil: Plummer, Kim M.. la Trobe University; AustraliaFil: Pradier, Jean-Marc. Institut National de la Recherche Agronomique; FranciaFil: Quévillon, Emmanuel. Institut National de la Recherche Agronomique; Francia. Centre National de la Recherche Scientifique; FranciaFil: Sharon, Amir. Tel Aviv University. Department of Molecular Biology and Ecology of Plants; IsraelFil: Simon, Adeline. Institut National de la Recherche Agronomique; FranciaFil: Tudzynski, Bettina. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Tudzynski, Paul. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Wincker, Patrick. Centre National de Séquençage. Genoscope; FranciaFil: Andrew, Marion. University Of Toronto; CanadáFil: Anthouard, Véronique. Centre National de Séquençage. Genoscope; FranciaFil: Beever, Ross E.. Landcare Research; Nueva ZelandaFil: Beffa, Rolland. Centre National de la Recherche Scientifique; FranciaFil: Benoit, Isabelle . Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países BajosFil: Bouzid, Ourdia. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajo

    Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

    Get PDF
    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t
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