265 research outputs found

    Pourquoi sélectionner de nouvelles variétés de blé tendre adaptées à l’agriculture biologique ?

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    International audienceLongtemps marginale en France, l’agriculture biologique est un secteur émergent à fort potentiel : les objectifs fixés par la loi Grenelle I ambitionnaient de faire passer les surfaces cultivées en agriculture biologique de 2% de la SAU française à 6% en 2012 puis de franchir un nouveau palier avec une couverture de 20% de la SAU en 2020. Même si en réalité c’est seulement 3% de la SAU qui est actuellement cultivée en agriculture biologique, les recherches consacrées à ce domaine, dont le cahier des charges interdit le recours aux produits de la chimie de synthèse, permettent d’anticiper le probable fort renchérissement du coût de l’énergie fossile (pic pétrolier).Ce travail pionnier de réduction des engrais et des pesticides sera alors utile à l’ensemble de l’agriculture. Tous les systèmes de culture ont bénéficié des progrès de la sélection végétale excepté l’agriculture biologique, parent pauvre de l’amélioration génétique. En effet la sélection s’est faite depuis 50 ans pour des itinéraires techniques artificialisés pour lesquels la fertilisation azotée minérale est abondante et où les herbicides sont utilisés pour lutter contre les adventices des cultures. Elle a conduit à l’obtention de variétés à paille courte donc peu concurrentielles vis-à-vis des mauvaises herbes et qui peinent en conditions de disponibilités réduites en azote, conditions rencontrées en agriculture biologique. La sélection variétale sur des critères adaptés à ces milieux aux contraintes fortes se justifie. Nous présenterons pourquoi elle peut être porteuse d’enseignements et discuterons de sa possible évolution au regard des premiers résultats obtenus

    On the validity of fMRI studies with subject-level data processed through different pipelines

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    In recent years, the lack of reproducibility of research findings has become an important source of concerns in many scientific fields, including functional Magnetic Resonance Imaging (fMRI). The low statistical power often observed in fMRI studies was identified as one of the leading causes of irreproducibility. The development of data sharing opens up new opportunities to achieve larger sample sizes by reusing existing data. FMRI studies proceed by first preparing subject-level data using a given analysis pipeline and then combining those into a group analysis. Historically the subject-level analysis pipeline was identical for all subjects. As practices evolve towards more data reuse, researchers might want to directly combine subject-level data thata were processed using different pipelines. Here, we investigate the impact of combining subject-level data processed with different pipelines in between-group fMRI studies. We used the HCP Young-Adult dataset (N=1,080 participants) processed with 24 different pipelines. We then performed between-group analyses comparing subject data processed with different pipelines. We worked under the null hypothesis of no differences between subjects and compared the estimated false-positive rates obtained with the nominal rates. We showed that the analytical variability induced by the parameters explored in this dataset increases the false positive rates of studies combining data from different pipelines. We conclude that different processed subject data cannot be combined without taking into account the processing applied on these data

    From selection to cultivation with the support of all stakeholders: first registration in France of two bread wheat varieties after VCU in organic farming system

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    As bread wheat is the most important cash crops for French organic farmers, the question of the kind of varieties farmers should be using is therefore very important. Most of varieties available were bred for intensive “conventional” farming systems (with high inputs of mineral fertilizers and pesticides), also screening current varieties for organic conditions becomes a necessity to identifiy suitable varieties for organic farming conditions in a short term experiment. After 20 years of selection and screening combined in two different crop management systems, low inputs and organic, two lines, Hendrix and Skerzzo, have been registered in the official catalogue with the special mention « organic farming ». For the second year of seed production, 150 hectares were sown in autumn 2013 to be sell to organic farmers in 2014. This successful process was possible with the support of all the agricultural organic sector associated in the initiative

    Inhomogeneous Si-doping of gold-seeded InAs nanowires grown by molecular beam epitaxy

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    We have investigated in-situ Si doping of InAs nanowires grown by molecular beam epitaxy from gold seeds. The effectiveness of n-type doping is confirmed by electrical measurements showing an increase of the electron density with the Si flux. We also observe an increase of the electron density along the nanowires from the tip to the base, attributed to the dopant incorporation on the nanowire facets whereas no detectable incorporation occurs through the seed. Furthermore the Si incorporation strongly influences the lateral growth of the nanowires without giving rise to significant tapering, revealing the complex interplay between axial and lateral growth.This work was supported by the ANR through the Project No. ANR-11-JS04-002-01, and the Ministry of Higher Education and Research, Nord-Pas de Calais Regional Council and FEDER through the “Contrat de Projets Etat Region (CPER) 2007-2013.” P.C. is the recipient of an Australian Research Council Future Fellowship (project number FT120100498)

    Mammography in asymptomatic women aged 40-49 years

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    OBJECTIVE To assess findings of mammography of and interventions resulting from breast cancer screening in women aged 40-49 years with no increased risk (typical risk) of breast cancer. METHODS This cross-sectional study evaluated women aged 40-49 years who underwent mammography screening in a mastology reference center in Recife, PE, Northeastern Brazil, between January 2010 and October 2011. Women with breast-related complaints, positive findings in the physical examination, or high risk of breast cancer were excluded. RESULTS The 1,000 mammograms performed were classified into the following Breast Imaging-Reporting and Data System (BI-RADS) categories BI-RADS 0, 232; BI-RADS 1, 294; BI-RADS 2, 294; BI-RADS 3, 16; BI-RADS 4A, 2; BI-RADS 5, 1. There was one case of grade II invasive ductal carcinoma and various interventions, including 469 ultrasound scans, 53 referrals to mastologists, 11 cytological examinations, and 8 biopsies. CONCLUSIONS Mammography screening in women aged 40-49 years with typical risk of breast cancer led to the performance of other interventions. However, it also resulted in increased costs without demonstrable efficacy in decreasing mortality.OBJETIVO Avaliar os achados mamográficos e as intervenções decorrentes do rastreamento em mulheres de 40 a 49 anos de idade com risco habitual para o câncer de mama. MÉTODOS Estudo transversal com mulheres de 40 a 49 anos, submetidas ao rastreamento mamográfico em centro de referência em mastologia, em Recife, PE, de janeiro de 2010 a outubro de 2011. Foram excluídas mulheres com queixas mamárias, alterações no exame físico e com alto risco para câncer de mama. RESULTADOS Das 1.000 mamografias realizadas, 232 foram BI-RADS 0, 454 BI-RADS 1, 294 BI-RADS 2, 16 BI-RADS 3, duas BI-RADS 4A, uma BI-RADS 4C e uma BI-RADS 5. Observou-se um único caso de carcinoma ductal invasivo grau II e várias intervenções: 469 ultrassonografias, 53 encaminhamentos para a mastologia, 11 citologias e oito biópsias. CONCLUSÕES O rastreamento mamográfico em mulheres de 40 a 49 anos com risco habitual para o câncer de mama leva a outras intervenções e, assim, ao aumento dos custos com eficácia não mostrada para redução da mortalidade

    Robust diameter-based thickness estimation of 3D objects

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    International audienceWe propose a robust thickness estimation approach for 3D objects based on the Shape Diameter Function (SDF). Our method first applies a modified strategy to estimate the local diameter with increased accuracy. We then compute a scale-dependent robust thickness estimate from a point cloud, constructed using this local diameter estimation and a variant of a robust distance function. The robustness of our method is benchmarked against several operations such as remeshing, geometric noise and artifacts common in triangle soups. The experimental results show a more stable local thickness estimation than the original SDF, and consistent segmentation results on defect-laden inputs

    \u3cem\u3eIonoSeis\u3c/em\u3e: A Package to Model Coseismic Ionospheric Disturbances

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    We present the framework of the modeling package IonoSeis. This software models Global Navigation Satellite System (GNSS) derived slant total electron content (sTEC) perturbations in the ionosphere due to the interaction of the neutral atmosphere and charged particles in the ionosphere. We use a simplified model to couple the neutral particle momentum into the ionosphere and reconstruct time series of sTEC perturbations that match observed data in both arrival time and perturbation shape. We propagate neutral atmosphere disturbances to ionospheric heights using a three-dimensional ray-tracing code in spherical coordinates called Windy Atmospheric Sonic Propagation (WASP3D), which works for a stationary or non-stationary atmospheric models. The source of the atmosphere perturbation can be an earthquake or volcanic eruption; both couple significant amounts of energy into the atmosphere in the frequency range of a few Millihertz. We demonstrate the output of the code by comparing modeled sTEC perturbation data to the observed perturbation recorded at GNSS station BTNG (Bitung, Indonesia) immediately following the 28 September 2018, Sulawesi-Palu earthquake. With this framework, we provide a software to couple the lithosphere, atmosphere, and ionosphere that can be used to study post-seismic ionospherically-derived signals

    Development of a natural ingredient – Natural preservative: A case study

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    AbstractLately, the cosmetic and personal care market has been more and more driven toward natural ingredients by the rising consumers' awareness about personal health and safety and their will for safer cosmetics free of harmful chemicals. Preservatives are no exception to the rule: evidence or suspicion of the toxicity of certain synthetic preservatives that have been around for decades pushed the cosmetic industry forward to seek for natural alternatives, as the selection of natural preservatives already available is quite limited. Sourcing active metabolites and developing new natural ingredients are long-term procedures that are thoroughly described in the present paper, via the example of the design of a natural preservative based on the Santolina chamaecyparissus extract, and of the assessments of its preservative effectiveness

    Verifying goal-oriented specifications used in model-driven development processes

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    [EN] Goal-oriented requirements engineering promotes the use of goals to elicit, elaborate, structure, specify, analyze, negotiate, document, and modify requirements. Thus, goal-oriented specifications are essential for capturing the objectives that the system to be developed should achieve. However, the application of goal oriented specifications into model-driven development (MDD) processes is still handcrafted, not aligned in the automated flow from models to code. In other words, the experience of analysts and designers is necessary to manually transform the input goal-oriented models into system models for code generation (models compilation). Some authors have proposed guidelines to facilitate and partially automate this translation, but there is a lack of techniques to assess the adequacy of goal-oriented models as starting point of MDD processes. In this paper, we present and evaluate a verification approach that guarantees the automatic, correct, and complete transformation of goal-oriented models into design models used by specific MDD solutions. In particular, this approach has been put into practice by adopting a well-known goal-oriented modeling approach, the i* framework, and an industrial MDD solution called Integranova.This work has been developed with the support of FONDECYT under the projects AMoDDI 11130583 and TESTMODE 11121395.This work is also supported by EOSSAC project, funded by the Ministry of Economy and Competitiveness of the Spanish government (TIN2013-44641-P).Giachetti Herrera, GA.; MarĂ­n, B.; LĂłpez, L.; Franch, X.; Pastor LĂłpez, O. (2017). Verifying goal-oriented specifications used in model-driven development processes. Information Systems. 64:41-62. https://doi.org/10.1016/j.is.2016.06.011S41626

    Mammography in asymptomatic women aged 40-49 years

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    OBJECTIVE To assess findings of mammography of and interventions resulting from breast cancer screening in women aged 40-49 years with no increased risk (typical risk) of breast cancer. METHODS This cross-sectional study evaluated women aged 40-49 years who underwent mammography screening in a mastology reference center in Recife, PE, Northeastern Brazil, between January 2010 and October 2011. Women with breast-related complaints, positive findings in the physical examination, or high risk of breast cancer were excluded. RESULTS The 1,000 mammograms performed were classified into the following Breast Imaging-Reporting and Data System (BI-RADS) categories BI-RADS 0, 232; BI-RADS 1, 294; BI-RADS 2, 294; BI-RADS 3, 16; BI-RADS 4A, 2; BI-RADS 5, 1. There was one case of grade II invasive ductal carcinoma and various interventions, including 469 ultrasound scans, 53 referrals to mastologists, 11 cytological examinations, and 8 biopsies. CONCLUSIONS Mammography screening in women aged 40-49 years with typical risk of breast cancer led to the performance of other interventions. However, it also resulted in increased costs without demonstrable efficacy in decreasing mortality
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