129 research outputs found

    Coupling far and near tectonic signals in syn-orogenic sediments: The Olvena growth strata (Sierras Marginales, southern Pyrenees)

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    The Olvena area (Sierras Marginales, southern Pyrenees) provides an outstanding example for studying the relationships between tectonics and sedimentation related to fold-and-thrust systems having shallow décollements. Stratigraphic and sedimentological features allow infer i) the relationship between Oligocene-Miocene locallysourced alluvial fans and a far-sourced wider fluvial system, and ii) the control exerted by tectonics on the stratigraphic architecture. Initially, uplift resulting from folding and thrusting in the Sierras Marginales precluded the entrance through this area into the Ebro basin of a wide fluvial system sourced in internal zones of the Pyrenean chain (including the Axial Zone). A subsiding area was created in the southern front of the Sierras where west-flowing alluvial fans generated, having their source areas in the rejuvenated reliefs. The subsequent cessation of movement of the tectonic structures permitted these reliefs to be subdued and the overpassing of the north-coming fluvial system that progressively covered a wider area. Sequential evolution and stratigraphic architecture evidence thrust emplacement geometry and chronology, including out-of-sequence reactivation of structures and the influence of evaporite flow along the décollement. Although these syn-tectonic deposits belong to the Ebro basin succession, its megasequential evolution differs from the general sequence established for the basin fill, highlighting the importance of differentiating the influence of near-coming sedimentary systems when interpreting basin-scale sequence stratigraphy

    Understanding sperm quality for improved reproductive performance

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    The assessment of semen quality is used to identify factors that influence sperm performance and diagnose male infertility [...

    Coupling far and near tectonic signals in syn-orogenic sediments: the Olvena growth strata (Sierras Marginales, southern Pyrenees)

    Get PDF
    The Olvena area (Sierras Marginales, southern Pyrenees) provides an outstanding example for studying the relationships between tectonics and sedimentation related to fold-and-thrust systems having shallow décollements. Stratigraphic and sedimentological features allow infer i) the relationship between Oligocene-Miocene locallysourced alluvial fans and a far-sourced wider fluvial system, and ii) the control exerted by tectonics on the stratigraphic architecture. Initially, uplift resulting from folding and thrusting in the Sierras Marginales precluded the entrance through this area into the Ebro basin of a wide fluvial system sourced in internal zones of the Pyrenean chain (including the Axial Zone). A subsiding area was created in the southern front of the Sierras where west-flowing alluvial fans generated, having their source areas in the rejuvenated reliefs. The subsequent cessation of movement of the tectonic structures permitted these reliefs to be subdued and the overpassing of the north-coming fluvial system that progressively covered a wider area. Sequential evolution and stratigraphic architecture evidence thrust emplacement geometry and chronology, including out-of-sequence reactivation of structures and the influence of evaporite flow along the décollement. Although these syn-tectonic deposits belong to the Ebro basin succession, its megasequential evolution differs from the general sequence established for the basin fill, highlighting the importance of differentiating the influence of near-coming sedimentary systems when interpreting basin-scale sequence stratigraphy

    Toward an integrative and predictive sperm quality analysis in Bos taurus

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    There is a need to develop more integrative sperm quality analysis methods, enabling researchers to evaluate different parameters simultaneously cell by cell. In this work, we present a new multi-parametric fluorescent test able to discriminate different sperm subpopulations based on their labeling pattern and motility characteristics. Cryopreserved semen samples from 20 Holstein bulls were used in the study. Analyses of sperm motility using computer-assisted sperm analysis (CASA-mot), membrane integrity by acridine orange-propidium iodide combination and multi-parametric by the ISAS®3Fun kit, were performed. The new method allows a clear discrimination of sperm subpopulations based on membrane and acrosomal integrity, motility and morphology. It was also possible to observe live spermatozoa showing signs of capacitation such as hyperactivated motility and changes in acrosomal structure. Sperm subpopulation with intact plasma membrane and acrosome showed a higher proportion of motile sperm than those with damaged acrosome or increased fluorescence intensity. Spermatozoa with intact plasmalemma and damaged acrosome were static or exhibit weak movement. Significant correlations among the different sperm quality parameters evaluated were also described. We concluded that the ISAS®3Fun is an integrated method that represents an advance in sperm quality analysis with the potential to improve fertility predictions

    Lateral error compensation for stitching-free measurement with focus variation microscopy

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    This paper proposes a practical methodology to quantify and compensate lateral errors for focus variation microscopy measurements without stitching. The main advantages of this new methodology are its fast and simple implementation using any uncalibrated artefact. The methodology is applied by performing measurements with multiple image fields with and without stitching on an uncalibrated artefact and using the stitched measurements as reference. To quantify the lateral errors, the determination of their geometrical components is carried out through kinematic modelling. With the quantified errors, compensation can be applied for lateral measurements without stitching. Over the entire 200mm lateral range, the lateral errors without stitching and without compensation can reach up to 180 mu m. With the proposed error compensation methodology, the lateral errors have been reduced to around 15 mu m. The proposed methodology can be applied to any Cartesian-based optical measuring instrument

    Effect of ambient temperature on machine tool compensation functions

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    Volumetric verification is increasing daily its relevance. However, as it is based on mathematical compensation, it does not model only the influence of the machine tool's geometric error to verify, but the total error of the data. Among all error sources, thermal variations due to changes in environmental conditions strongly affect MT position accuracy. This paper studies how verification changes affect compensation functions based on a modification of machine tool kinematic model and a generator of synthetic data. It takes into consideration the influence of the measurement noise on verification too. Moreover, the paper also studies how differences between verification and working conditions affect the accuracy of MT compensation functions. To do that, a brief explanation of the developed algorithm is presented

    Coupling far and near tectonic signals in syn-orogenic sediments : the Olvena growth strata (Sierras Marginales, southern Pyrenees)

    Get PDF
    The Olvena area (Sierras Marginales, southern Pyrenees) provides an outstanding example for studying the relationships between tectonics and sedimentation related to fold-and-thrust systems having shallow décollements. Stratigraphic and sedimentological features allow infer i) the relationship between Oligocene-Miocene locallysourced alluvial fans and a far-sourced wider fluvial system, and ii) the control exerted by tectonics on the stratigraphic architecture. Initially, uplift resulting from folding and thrusting in the Sierras Marginales precluded the entrance through this area into the Ebro basin of a wide fluvial system sourced in internal zones of the Pyrenean chain (including the Axial Zone). A subsiding area was created in the southern front of the Sierras where west-flowing alluvial fans generated, having their source areas in the rejuvenated reliefs. The subsequent cessation of movement of the tectonic structures permitted these reliefs to be subdued and the overpassing of the north-coming fluvial system that progressively covered a wider area. Sequential evolution and stratigraphic architecture evidence thrust emplacement geometry and chronology, including out-of-sequence reactivation of structures and the influence of evaporite flow along the décollement. Although these syn-tectonic deposits belong to the Ebro basin succession, its megasequential evolution differs from the general sequence established for the basin fill, highlighting the importance of differentiating the influence of near-coming sedimentary systems when interpreting basin-scale sequence stratigraphy

    Lateral error compensation for focus variation microscopy

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    Focus variation microscopy measures both the areal form and areal surface texture of components. Improvements to the accuracy and precision of focus variation microscopes usually requires measurements with multiple image-fields to compensate lateral stage errors. This paper proposes a methodology for compensation of lateral stage error of a focus variation microscope using an uncalibrated artefact

    Ability of the isas3fun method to detect sperm acrosome integrity and its potential to discriminate between high and low field fertility bulls

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    The objective of the present study was to investigate whether fertility differences in bulls are reflected in variations of sperm quality when analysing only one ejaculate per male. Two experiments were performed. In the first experiment, frozen semen samples from 20 adult bulls were tested; 10 bulls had high field fertility and 10 bulls had low field fertility. Analyses of sperm motility, membrane integrity, and membrane–acrosome integrity with the ISAS3Fun method were performed. Sperm morphometry of the fluorescence sperm subpopulations obtained with the ISAS3Fun method was also analysed. Significant differences between high-and low-fertility groups were only found with the ISAS3Fun technique, specifically in sperm acrosome integrity, the proportion of spermatozoa with an intact acrosome and damaged membrane, and in sperm head width of spermatozoa with intact structures. Discriminant analyses allowed us to correctly classify 90% of sperm samples in their fertility group using sperm quality parameters. Given that only the results obtained with the ISAS3Fun technique were related to bull fertility, we performed a second experiment aimed to validate the efficacy of this technique to detect the acrosomal integrity of bull spermatozoa, comparing them with the conventional FITC-PNA/propidium iodide (PNA/PI) combination under capacitating conditions. The results indicated that the ISAS3Fun combination provided an accurate assessment of both viability and acrosomal integrity for ejaculated spermatozoa, while the PNA/PI combination underestimated the extension of acrosomal damage due to false negatives. It was concluded that the simultaneous assessment of sperm plasma membranes and acrosome integrity with the ISAS3Fun method is precise and seems to have a greater potential to discriminate between high-and low-fertility bulls than more conventional in vitro sperm quality tests. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Aportaciones de la modelización analógica al estudio de la deformación intraplaca

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    Se han realizado modelos analógicos de sistemas frágil/dúctil dinámicamente dimensionados. Los experimentos consistieron en comprimir longitudinalmente un paquete de arena con un nivel basal de silicona que funciona como un nivel de despegue. Las condiciones en los límites se eligieron para analizar la influencia de la migración lateral del nivel dúctil, así como de la velocidad de deformación en el patrón de deformación resultante. Los resultados obtenidos indican que cuando el nivel dúctil migra lateralmente el mayor engrosamiento cortical no se produce en la zona más próxima al back-stop, sino que aparece desplazado hacia el interior del modelo. Dynamically scaled brittle/ductile analogue models have been performed. Experiments consisted of the compression of a sand-pack with a basal ductile layer of silicone putty acting as a décollement level. The boundary conditions were chosen to analyze the influence of the lateral migration of the ductile level and the strain rate on the deformational pattern. Results show that when the ductile level migrates laterally, the higher thickening is obtained far from the back-stop creating a high relief in the pro-wedge region
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