43 research outputs found

    Experiment vs Simulation RT WFNDEC 2014 Benchmark: CIVA Results

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    41st Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Boise, ID, JUL 20-25, 2014International audienceThe French Atomic Energy Commission and Alternative Energies (CEA) has developed for years the CIVA software dedicated to simulation of NDE techniques such as Radiographic Testing (RI). RI modelling is achieved in CIVA using combination of a determinist approach based on ray tracing for transmission beam simulation and a Monte Carlo model for the scattered beam computation. Furthermore, CIVA includes various detectors models, in particular common x-ray films and a photostimulable phosphor plates. This communication presents the results obtained with the configurations proposed in the World Federation of NDEC 2014 RT modelling benchmark with the RI models implemented in the CIVA software

    Real-time high-resolution topographic imagery using interference microscopy

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    New instrumentation has been developed that is dedicated to the measurement of surface morphology with high resolutions and short acquisition times. Sinusoidal phase-shifting interferometry is demonstrated to provide within an acquisition time of only a few milliseconds topographic images with ~1 nm height precision, ~1 μm lateral resolution, and a few tens of pm sensitivity. A white-light scanning microscope is also under development, using an in-house developed high speed, intelligent CCD camera, the first tests of which demonstrate the feasibility of providing topographic images of deep surface relief (several microns to several tens of microns) within less than 0.3 s. The useful lateral field of view can be extended by employing image “stitching” while maintaining a high lateral resolution.

    Larval transcriptomic response to host plants in two related phytophagous lepidopteran species: implications for host specialization and species divergence

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    Abstract Background Most phytophagous insects have morphological, behavioral and physiological adaptations allowing them to specialize on one or a few plant species. Identifying the mechanisms involved in host plant specialization is crucial to understand the role of divergent selection between different environments in species diversification, and to identify sustainable targets for the management of insect pest species. In the present study, we measured larval phenotypic and transcriptomic responses to host plants in two related phytophagous lepidopteran species: the European corn borer (ECB), a worldwide pest of maize, and the adzuki bean borer (ABB), which feeds of various dicotyledons. Our aim was to identify the genes and functions underlying host specialization and/or divergence between ECB and ABB. Results At the phenotypic level, we observed contrasted patterns of survival, weight gain and developmental time between ECB and ABB, and within ECB and ABB reared on two different host plants. At the transcriptomic level, around 8% of the genes were differentially expressed (DE) between species and/or host plant. 70% of these DE genes displayed a divergent pattern of expression between ECB and ABB, regardless of the host, while the remaining 30% were involved in the plastic response between hosts. We further categorized plastic DE genes according to their parallel or opposite pattern between ECB and ABB to specifically identify candidate genes involved in the species divergence by host specialization. These candidates highlighted a comprehensive response, involving functions related to plant recognition, digestion, detoxification, immunity and development. Last, we detected viral, bacterial, and yeast genes whose incidence contrasted ECB and ABB samples, and maize and mugwort conditions. We suggest that these microorganism communities might influence the survival, metabolism and defense patterns observed in ECB and ABB larvae. Conclusions The comprehensive approach developed in the present study allowed to identify phenotypic specialization patterns and underlying candidate molecular mechanisms, and highlighted the putative role of microorganisms in the insect-host plant interaction. These findings offer the opportunity to pinpoint specific and sustainable molecular or physiological targets for the regulation of ECB pest populations

    Fast X-ray imaging of cavitating flows

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    A new method based on ultra-fast X-ray imaging was developed in this work for the investigation of the dynamics and the structures of complex two-phase flows. In this paper, cavitation was created inside a millimetric 2D Venturi-type test section, while seeding particles were injected into the flow. Thanks to the phase-contrast enhancement technique provided by the APS (Advanced Photon Source) synchrotron beam, high definition X-ray images of the complex cavitating flows were obtained. These images contain valuable information about both the liquid and the gaseous phases. By means of image processing, the two phases were separated, and velocity fields of each phase were, therefore, calculated using image cross-correlations. The local vapour volume fractions were also obtained, thanks to the local intensity levels within the recorded images. These simultaneous measurements, provided by this new technique, afford more insight into the structure and the dynamic of two-phase flows as well as the interactions between them, and hence enable to improve our understanding of their behaviour. In the case of cavitating flows inside a Venturi-type test section, the X-ray measurements demonstrate, for the first time, the presence of significant slip velocities between the phases within sheet cavities for both steady and unsteady flow configurations

    Additional file 5: of Larval transcriptomic response to host plants in two related phytophagous lepidopteran species: implications for host specialization and species divergence

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    Table S7. Detailed information for DE genes displaying significant sequence similarity to genes previously described in bacteria: mean normalized counts per experimental set-up, model effects (host plant, moth species, interaction) and functional annotations. (XLSX 46 kb
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