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AbstractEnergy crops are currently promoted as potential sources of alternative energy that can help mitigate the climate change caused by greenhouse gases (GHGs). The perennial crop Miscanthus × giganteus is considered promising due to its high potential for biomass production under conditions of low input. However, to assess its potential for GHG mitigation, a better quantification of the crop's contribution to soil organic matter recycling under various management systems is needed. The aim of this work was to study the effect of abscised leaves on carbon (C) and nitrogen (N) recycling in a Miscanthus plantation. The dynamics of senescent leaf fall, the rate of leaf decomposition (using a litter bag approach) and the leaf accumulation at the soil surface were tracked over two 1‐year periods under field conditions in Northern France. The fallen leaves represented an average yearly input of 1.40 Mg C ha−1 and 16 kg N ha−1. The abscised leaves lost approximately 54% of their initial mass in 1 year due to decomposition; the remaining mass, accumulated as a mulch layer at the soil surface, was equivalent to 7 Mg dry matter (DM) ha−1 5 years after planting. Based on the estimated annual leaf‐C recycling rate and a stabilization rate of 35% of the added C, the annual contribution of the senescent leaves to the soil C was estimated to be approximately 0.50 Mg C ha−1yr−1 or 10 Mg C ha−1 total over the 20‐year lifespan of a Miscanthus crop. This finding suggested that for Miscanthus, the abscised leaves contribute more to the soil C accumulation than do the rhizomes or roots. In contrast, the recycling of the leaf N to the soil was less than for the other N fluxes, particularly for those involving the transfer of N from the tops of the plant to the rhizome.

ABSTRACT The objective of this study was to evaluate the effect of the conversion of secondary native vegetation (NV) to conventional systems (agriculture and pasture) in soil organic carbon (SOC) and carbon of fractions particulate organic matter (POM) and mineral-associated organic matter (MAOM) in the Brazilian semi-arid region. The study was carried out in the municipalities of Delmiro Gouveia, Inhapi and Pariconha, in Alagoas, Brazil. Soils were collected in the layers of 0-0.1, 0.1-0.2 and 0.2-0.3 m. The treatments analyzed were: agricultural crops with 4, 15 and 30 years and pasture with 10 years. As a reference, the secondary Caatinga was used. The results show that in soils with sandy texture (Neossolos Quartzarênico and Regolítico – Arenosols and Regosols, respectively), there were reductions in SOC levels and carbon in the compartment associated with minerals. The inverse can be observed in the clay-textured Argissolo (Acrisols), with 30 years of cultivation, in which there was an increase in SOC and C in the quantitative fractions of soil organic matter. In addition, despite the sandy texture of the Neossolo Regolítico, POM levels were increased in the pasture system in comparison to native vegetation, but it was not enough to recover the original SOC content of this system. RESUMO O objetivo deste estudo foi avaliar o efeito da conversão da vegetação nativa secundária (VN) em sistemas convencionais (agricultura e pastagem) no carbono orgânico total (COS) e carbono das frações da matéria orgânica particulada (MOP) e, matéria orgânica associada aos minerais (MOAM) no semiárido brasileiro. O estudo foi realizado nos municípios de Delmiro Gouveia, Inhapi e Pariconha, em Alagoas. Os solos foram coletados nas camadas de 0-0.1, 0.1-0.2 e 0.2-0.3 m. Os tratamentos analisados foram: cultivos agrícolas com 4, 15 e 30 anos e, pastagem com 10 anos. Como referência utilizou-se a Caatinga secundária. Os resultados mostram que em solos com textura mais arenosa (Neossolos Quartzarênico e Regolítico – Arenosols e Regosols, respectivamente) há reduções nos níveis de COS e carbono no compartimento associada aos minerais. O inverso pode ser observado no Argissolo (Acrisols), de textura argilosa com 30 anos de cultivo, o qual ocorreu um aumento no COS e C nas frações quantitativas da matéria orgânica do solo. Além disso, apesar da textura arenosa do Neossolo Regolítico, os níveis de MOP foram aumentados no sistema de pasto em relação à vegetação nativa, todavia não o suficiente para recuperar o conteúdo original de COS desse sistema.

<p class="CORPOICA"><span lang="ES-CO">Se obtuvieron predicciones acerca de los efectos genéticos aditivos y no aditivos relativos al peso al destete en terneros pertenecientes a un rebaño multirracial Angus x Brahman, valiéndose de un procedimiento de evaluación animal multirracial; estos valores se compararon frente a predicciones de los efectos genéticos basadas en evaluaciones que contemplaban únicamente los efectos aditivos. Se encontraron cambios substanciales en las predicciones de los efectos genéticos cuando se incluyeron los efectos genéticos no aditivos en la evaluación. Éstos originaron diferencias en el ordenamiento de los toros para los efectos genéticos aditivos y totales. Por lo tanto, en la selección de toros destinados a programas de cruzamiento, se recomienda usar evaluaciones genéticas multirraciales que involucren los efectos genéticos no aditivos.</span></p><p class="CORPOICA"> </p><p class="CORPOICA"><strong>Prediction of Additive and Nonadditive Genetic Effects for Weight at Weaning Using a Multibreed Animal Evaluation Procedure</strong></p><p class="CORPOICA"><span lang="EN-US">Additive and nonadditive genetic effects were predicted for weaning weight in an Angus-Brahman multibreed herd by using a multibreed animal evaluation procedure and were compared to the predictions of genetic effects based only on additive genetic effects. Changes in the prediction of genetic effects were found when nonadditive genetic efects were included in the genetic evaluation procedure. </span><span lang="ES-CO">These changes caused differences in the ranking of sires for additive and total genetic effects. </span><span lang="EN-US">Therefore, when bulls used in crossbreeding programs are to be chosen, it should be valuable to use multibreed genetic evaluations that involve nonadditive genetic effects.</span></p>

International audience

The present study had as objective evaluates the physiologic behavior of different genetic groups of sheep created in the semi-arid paraibano in the dry and rainy times. Forty sheep were used, eight of each genetic group, distributed entirely in a randomized design. There was shift effect, for all the environmental variables and studied physiologic parameters. There were significant interactions of the factors genotypes, time and hour for the parameters, rectal temperature and breathing frequency. With relationship to the Index of tolerance to the heat (ITC) significant effect of the studied factors was not verified. With these results it can be ended that the races Santa Inês, Cariri and the products, resultants of crossings of the animals ½Dorper and ½Damara with sheep without defined race (SRD) they resemble each other in the adaptation aspect to the conditions of the semi-arid.

O trabalho teve como objetivo avaliar o potencial de clones de Eucalyptus urophylla para produção de painéis aglomerados homogêneos de baixa densidade. Foram avaliados seis clones de Eucalyptus urophylla com 94 meses de idade, plantados no municipio de Paracatu-MG, sendo utilizada como parâmetro de comparação a madeira de Pinus oocarpa. Para cada clone de Eucalyptus urophylla e também para o Pinus oocarpa foram produzidos seis painéis com o adesivo uréia-formaldeido no teor de 6%, densidade nominal de 0,60 g/cm³, pressão especifica de 40kgf/cm², temperatura de 160ºC e tempo de 8 minutos. Os clones de Eucalyptus urophylla apresentaram potencial para produção de painéis aglomerados convencionais de baixa densidade. Os clones 62 e 28 obtiveram os melhores resultados em todas as propriedades fisico-mecânicas avaliadas, apresentando propriedades iguais ou superiores as obtidas para os painéis produzidos com a madeira de Pinus oocarpa. Com relação à norma de comercialização CS 236/1966 apenas o clone 28 atendeu a todos os requisitos. Nenhum dos clones avaliados atendeu a norma EN 312/2003.

This study develops a modelling framework by utilizing multi-sensor imagery for classifying different forest and land use types in the Phnom Kulen National Park (PKNP) in Cambodia. Three remote sensing datasets (Landsat optical data, ALOS L-band data and LiDAR derived Canopy Height Model (CHM)) were used in conjunction with three different machine learning (ML) regression techniques (Support Vector Machines (SVM), Random Forests (RF) and Artificial Neural Networks (ANN)). These ML methods were implemented on (a) Landsat spectral data, (b) Landsat spectral band & ALOS backscatter data, and (c) Landsat spectral band, ALOS backscatter data, & LiDAR CHM data. The Landsat-ALOS combination produced more accurate classification results (95% overall accuracy with SVM) compared to Landsat-only bands for all ML models. Inclusion of LiDAR CHM (which is a proxy for vertical canopy heights) improved the overall accuracy to 98%. The research establishes that majority of PKNP is dominated by cashew plantations and the nearly intact forests are concentrated in the more inaccessible parts of the park. The findings demonstrate how different RS datasets can be used in conjunction with different ML models to map forests that had undergone varying levels of degradation and plantations. International audience

This work seeks to mitigate the effects of constraints on mobile robotic systems. To this end, auxiliary control loops and robust tuning techniques are proposed. The former are proposed to mitigate the effects of constraints on the input and output of the systems through the modification of the motion parameter in path following applications.Then, PID controllers are considered as a structural constraint, given its wide use in robotics particularly at low control level. A robust tuning methodology considering this constraint is proposed which achieves good performancelevels even when facing disturbances. Finally, to deal with robustness in presence of robots nonlinearity constraints, an analysis and tuning tool for sliding mode controllers is proposed. The particularity of this tuning method, based on global optimization and interval techniques,is that it allows generating tuning maps of the parameter regions where the desired performance criterion is fulfilled. All the proposed strategies are put into practice, through real experimentation or invalidated simulators, over the AUV Ciscrea available at ENSTA Bretagne.; Ce travail vise à atténuer les effets des contraintes sur les systèmes robotiques mobiles. À cette fin, des structures de commande auxiliaire et des techniques de réglage robuste sont proposées. Les structures sont proposées dans le cadre du suivi de chemin pour atténuer les effets des contraintes sur les entrées et les sorties des systèmes. Ensuite, étant donnée leur utilisation répandue en robotique, les contrôleurs de type PID sont considérés comme une contrainte structurelle. Une méthode de réglage robuste, tenant compte de cette contrainte, est proposée permettant d’atteindre de bons niveaux de performance même en présence de perturbations. Enfin, pour faire face à la robustesse en présence des contraintes de non-linéarité sur robots, un outil d’analyse et de réglage pour les contrôleurs de mode glissant est proposé. La particularité de cette méthode de réglage, basée sur des techniques d’optimisation globale et de calculs par intervalles, est qu’elle permet de générer des cartographies de réglage des paramètres pour lesquels le critère de performance souhaité est rempli.Toutes les stratégies proposées sont mises en pratique par des expérimentations réelles ou sur des simulateurs validés (AUV Ciscrea disponible à l’ENSTA Bretagne).