1,276 research outputs found

    Ferruginous biolaminations within the pre-Hirnantian (Late Ordovician) of the Carnic Alps, Austria

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    Well preserved laminated structures occur within the Upper Ordovician of the Cellon section in the Carnic Alps (Austria), a world-famous reference section for Silurian conodont biostratigraphy. Microfacies from the Upper Ordovician Uqua Formation were characterised by using optical and scanning electron microscopy (SEM), an environmental scanning electron microscopy coupled with microanalyses (SEM/ESEM-EDX) and a confocal laser Raman microscopy. Ferruginous laminated structures overgrowing specific skeletal fragments occur in the lower part of the studied unit in the form of finely red-to greenish coatings composed of chamosite and goethite alternating with calcite bands. Laminae have arborescent to dendrolitic morphologies. Such morphologies suggest a biomediated genesis and the existence of a potential microbial factory acting in a nearby location from which coated material was later redeposited. These ferruginous coatings around organisms are not documented within the latest Ordovician Plöcken Formation at Cellon or in the coeval Wolayer Formation elsewhere.Well preserved laminated structures occur within the Upper Ordovician of the Cellon section in the Carnic Alps (Austria), a world-famous reference section for Silurian conodont biostratigraphy. Microfacies from the Upper Ordovician Uqua Formation were characterised by using optical and scanning electron microscopy (SEM), an environmental scanning electron microscopy coupled with microanalyses (SEM/ESEM-EDX) and a confocal laser Raman microscopy. Ferruginous laminated structures overgrowing specific skeletal fragments occur in the lower part of the studied unit in the form of finely red-to greenish coatings composed of chamosite and goethite alternating with calcite bands. Laminae have arborescent to dendrolitic morphologies. Such morphologies suggest a biomediated genesis and the existence of a potential microbial factory acting in a nearby location from which coated material was later redeposited. These ferruginous coatings around organisms are not documented within the latest Ordovician Plöcken Formation at Cellon or in the coeval Wolayer Formation elsewhere

    Quantitative trait loci for flowering time and inflorescence architecture in rose

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    The pattern of development of the inflorescence is an important characteristic in ornamental plants, where the economic value is in the flower. The genetic determinism of inflorescence architecture is poorly understood, especially in woody perennial plants with long life cycles. Our objective was to study the genetic determinism of this characteristic in rose. The genetic architectures of 10 traits associated with the developmental timing and architecture of the inflorescence, and with flower production were investigated in a F 1 diploid garden rose population, based on intensive measurements of phenological and morphological traits in a field. There were substantial genetic variations in inflorescence development traits, with broad-sense heritabilities ranging from 0.82 to 0.93. Genotypic correlations were significant for most (87%) pairs of traits, suggesting either pleiotropy or tight linkage among loci. However, non-significant and low correlations between some pairs of traits revealed two independent developmental pathways controlling inflorescence architecture: (1) the production of inflorescence nodes increased the number of branches and the production of flowers; (2) internode elongation connected with frequent branching increased the number of branches and the production of flowers. QTL mapping identified six common QTL regions (cQTL) for inflorescence developmental traits. A QTL for flowering time and many inflorescence traits were mapped to the same cQTL. Several candidate genes that are known to control inflorescence developmental traits and gibberellin signaling in Arabidopsis thaliana were mapped in rose. Rose orthologues of FLOWERING LOCUS T (RoFT), TERMINAL FLOWER 1 (RoKSN), SPINDLY (RoSPINDLY), DELLA (RoDELLA), and SLEEPY (RoSLEEPY) co-localized with cQTL for relevant traits. This is the first report on the genetic basis of complex inflorescence developmental traits in rose

    On biosignatures for Mars

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    In this work, we address the difficulty of reliably identifying traces of life on Mars. Several independent lines of evidence are required to build a compelling body of proof. In particular, we underline the importance of correctly interpreting the geological and mineralogical context of the sites to be explored for the presence of biosignatures. We use as examples to illustrate this, ALH84001 (where knowledge of the geological context was very limited) and other terrestrial deposits, for which this could be properly established. We also discuss promising locations and formations to be explored by ongoing and future rover missions, including Oxia Planum, which, dated at 4.0 Ga, is the most ancient Mars location targeted for investigation yet

    Separation between coherent and turbulent fluctuations. What can we learn from the Empirical Mode Decomposition?

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    The performances of a new data processing technique, namely the Empirical Mode Decomposition, are evaluated on a fully developed turbulent velocity signal perturbed by a numerical forcing which mimics a long-period flapping. First, we introduce a "resemblance" criterion to discriminate between the polluted and the unpolluted modes extracted from the perturbed velocity signal by means of the Empirical Mode Decomposition algorithm. A rejection procedure, playing, somehow, the role of a high-pass filter, is then designed in order to infer the original velocity signal from the perturbed one. The quality of this recovering procedure is extensively evaluated in the case of a "mono-component" perturbation (sine wave) by varying both the amplitude and the frequency of the perturbation. An excellent agreement between the recovered and the reference velocity signals is found, even though some discrepancies are observed when the perturbation frequency overlaps the frequency range corresponding to the energy-containing eddies as emphasized by both the energy spectrum and the structure functions. Finally, our recovering procedure is successfully performed on a time-dependent perturbation (linear chirp) covering a broad range of frequencies.Comment: 23 pages, 13 figures, submitted to Experiments in Fluid

    A breathing zirconium metal-organic framework with reversible loss of crystallinity by correlated nanodomain formation

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    The isoreticular analogue of the metal-organic framework UiO-66(Zr), synthesized with the flexible trans-1,4-cyclohexanedicarboxylic acid as linker, shows a peculiar breathing behavior by reversibly losing long-range crystalline order upon evacuation. The underlying flexibility is attributed to a concerted conformational contraction of up to two thirds of the linkers, which breaks the local lattice symmetry. X-ray scattering data are described well by a nanodomain model in which differently oriented tetragonal-type distortions propagate over about 7-10 unit cells

    Effect of GA 3 and paclobutrazol on adventitious shoot regeneration of two Pelargonium sp

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    This study had two aims. The first was to improve the regeneration efficiency of Pelargonium leaf discs by adventitious budding. The second was to test the effect of gibberellic acid (GA 3) and paclobutrazol (PBZ) on callus formation and adventitious shoot regeneration in Pelargonium before using genetic transformation of this species for functional validation of genes involved in the process of GA regulation. GA 3 and paclobutrazol (an inhibitor of GA synthesis pathway) were added (together or separately) in the shoot regeneration media of two Pelargonium species, Pelargonium * hortorum \u27Panache sud\u27 (\u27P.sud\u27) and Pelargonium * domesticum \u27Autumn haze\u27 (\u27 P.dom\u27). In both cases, GA 3 applied alone, completely inhibited the bud regeneration. Moreover, the rate of callus formation decreased drastically when 5 M of GA 3 was applied to \u27 P. dom\u27 explants. Similar result was obtained with \u27P.sud\u27 explants using 20 M GA 3. Paclobutrazol (0.3 M) applied at the same time as GA 3 (10 M) could partially restore regeneration process of \u27 P. dom\u27. For \u27 P. dom\u27, the use of paclobutrazol alone increased callus formation and slightly improved the rate of regeneration. Moreover, initiated buds had a better appearance. For \u27P. sud\u27, which had an abundant callusing, paclobutrazol did not improve regeneration and led to hyperhydric shoots

    Weak radiative hyperon decays, Hara's theorem and the diquark

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    Weak radiative hyperon decays are discussed in the diquark-level approach. It is pointed out that in the general diquark formalism one may reproduce the experimentally suggested pattern of asymmetries, while maintaining Hara's theorem in the SU(3) limit. At present, however, no detailed quark-based model of parity-violating diquark-photon coupling exists that would have the necessary properties.Comment: 10 pages, LaTe

    Mutations des régions frontalières avec l’Union européenne: Cahiers du CEFRES N° 9f, Territoires en mutation

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    International audienceCette seconde table ronde a pour sujet les mutations des régions frontalières avec l’Union européenne. Tout d’abord, Michel Foucher (Université Lumière Lyon II) s’intéresse à la problématique sans cesse renouvelée des frontières internes et externes de l’Union européenne, puis G. Lepesant (CERI) se concentre sur les échanges et la coopération aux frontières orientales de l’Allemagne. Jiří Patočka (AV ČR) communique ensuite sur certains aspects du développement des eurorégions en République tchèque tandis que František Zich (UK) s’intéresse aux évolutions des relations entre les habitants des régions frontalières germano-tchèques. Suivent une communication de Giorgio Ficarelli (Comission européenne) sur les actions de soutien de l’Union européenne à la coopération transfrontalière, une autre de Jaroslav Zámečník qui se focalise sur une expérience particulière de coopération frontalière, celle de l’eurorégion Nisa, et une autre de Milan Jeřábek (Masarykova Univerzita), commentant les résultats de sondages réalisés dans les régions frontalières tchéco-allemandes. Enfin, Jiří Tomeš (UK) réfléchit à une problématisation de la différenciation régionale et de son contexte politique et Ľubomír Falťan (SAS) conclut sur quelques remarques au sujet des relations transfrontalières austro-slovaques

    An oligofluorene truxene based distributed feedback laser for biosensing applications

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    The first example of an all-organic oligofluorene truxene based distributed feedback laser for the detection of a specific protein–small molecule interaction is reported. The protein avidin was detected down to View the MathML source1μgmL−1 using our biotin-labelled biosensor platform. This interaction was both selective and reversible when biotin was replaced with desthiobiotin. Avidin detection was not perturbed by Bovine Serum Albumin up to View the MathML source50,000μgmL−1. Our biosensor offers a new detection platform that is both highly sensitive, modular and potentially re-usable
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