4,358 research outputs found

    A Fast Splitting Method for efficient Split Bregman Iterations

    Full text link
    In this paper we propose a new fast splitting algorithm to solve the Weighted Split Bregman minimization problem in the backward step of an accelerated Forward-Backward algorithm. Beside proving the convergence of the method, numerical tests, carried out on different imaging applications, prove the accuracy and computational efficiency of the proposed algorithm

    How to enhance crop production and nitrogen fluxes? A result-oriented scheme to evaluate best agri-environmental measures in Veneto Region, Italy

    Get PDF
    The cost-effectiveness of adopting agri-environmental measures (AEMs) in Europe, which combine agricultural productions with reduced N losses, is debated due to poorly targeted site-specific funding that is allocated regardless of local variability. An integrated DAYCENT model-GIS platform was developed combining pedo-climatic and agricultural systems information. The aim was to evaluate best strategies to improve N fluxes of agro-ecosystems within a perspective of sustainable intensification. Indicators of agronomic efficiency and environmental quality were considered. The results showed that agronomic benefits were observed with a continuous soil cover (conservation agriculture and cover crops), which enhanced nitrogen use efficiency (+17%) and crop yields (+34%), although in some cases these might be overestimated due to modelling limitations. An overall environmental improvement was found with continuous soil cover and long-term change from mineral to organic inputs (NLeach 45 Mg ha 121), which were effective in the sandy soils of western and eastern Veneto with low SOM, improving the soil-water balance and nutrients availability over time. Results suggest that AEM subsidies should be allocated at a site-specific level that includes pedo-climatic variability, following a result-oriented approach

    Assessing the Accuracy and Power of Population Genetic Inference from Low-Pass Next-Generation Sequencing Data

    Get PDF
    Next-generation sequencing (NGS) technologies have made it possible to address population genetic questions in almost any system, but high error rates associated with such data can introduce significant biases into downstream analyses, necessitating careful experimental design and interpretation in studies based on short-read sequencing. Exploration of population genetic analyses based on NGS has revealed some of the potential biases, but previous work has emphasized parameters relevant to human population genetics and further examination of parameters relevant to other systems is necessary, including situations where sample sizes are small and genetic variation is high. To assess experimental power to address several principal objectives of population genetic studies under these conditions, we simulated population samples under selective sweep, population growth, and population subdivision models and tested the power to accurately infer population genetic parameters from sequence polymorphism data obtained through simulated 4×, 8×, and 15× read depth sequence data. We found that estimates of population genetic differentiation and population growth parameters were systematically biased when inference was based on 4× sequencing, but biases were markedly reduced at even 8× read depth. We also found that the power to identify footprints of positive selection depends on an interaction between read depth and the strength of selection, with strong selection being recovered consistently at all read depths, but weak selection requiring deeper read depths for reliable detection. Although we have explored only a small subset of the many possible experimental designs and population genetic models, using only one SNP-calling approach, our results reveal some general patterns and provide some assessment of what biases could be expected under similar experimental structures

    Magnetic island evolution under the action of electron cyclotron current drive

    Get PDF
    The magnetic island evolution under the action of an externally current generated by electron cyclotron (ECCD) wave beams is studied using a reduced resistive magnetohydrodynamics (RRMHD) plasma model. We found interesting and somewhat unexpected features of the actual nonlinear 2-D evolution of the magnetic perturbation depending on the injection time of the radio frequency control. In particular in the linear phase of the magnetic island growth we observe that the complete annihilation of the island width is followed by a spatial phase shift of the island, referred as «flip»instability. On the other hand, a current drive deposition in the Rutherford regime can be accompained by the occurrence of a Kelvin-Helmholtz type shear flow instability, responsible for the onset of a plasma turbulent behavio

    La actuación del contador público en el cambio del régimen patrimonial matrimonial según el nuevo Código Civil y Comercial de la Nación

    Get PDF
    El 8 de octubre de 2014 se realizó la publicación en el Boletín oficial de la ley 26.994 que sancionó la implementación del nuevo Código Civil y Comercial de la República Argentina. Esta nueva norma trajo consigo diversas modificaciones abiertas a distintos tipos de interpretaciones, estudios y/o análisis entre las cuales se encuentra la posibilidad de adoptar un nuevo régimen Matrimonial Patrimonial. Es decir que una pareja antes de iniciar su matrimonio puede optar ya sea por el régimen de Comunidad o el régimen de separación de bienes como normas que van a regir el antes y el después de la gestión de bienes y deudas de la sociedad conyugal. Como así también se permite que una vez adoptado uno de los regímenes se pueda cambiar por otro. Cuando una pareja decide abandonar el régimen de comunidad y adoptar el régimen de separación de bienes se abre la puerta a nuevas fuentes laborales para profesionales de diferentes campos entre los cuales se encuentra el Contador Público. La actuación, idoneidad y capacidad del mismo es fundamental para llevar a cabo esta tarea, lo que se explica en este trabajo, donde se analiza el rol del Contador Público en la extinción por cambio del régimen patrimonial matrimonial encontrándose vigente el matrimonio y se analizan los distintos regímenes que permite adoptar la legislación vigente.Fil: Belelli, María José. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: Gofre, Katherina E.. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: Lazzaro, Jimena. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas

    Different communities hosting Ionopsidium savianum (Caruel) Arcang. in Tuscany: a trait perspective.

    Get PDF
    corecore