63 research outputs found

    La modélisation : une aide à la gestion de l'irrigation de précision : cas de l'orangeraie d'El-Salam, Nord Sinaï (Egypte)

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    Des études sur l'économie de l'eau dans le Delta du Nil ont été menées en 2011-2013 à l'Institut de Recherche pour le Développement. L'orangeraie El-Salam a été choisie comme station d'étude "étalon". Ces études concernent le mode de gestion de l'irrigation de précision, avec comme perspective, la mise au point d'un modèle utilisable pour la gestion de l'irrigation d'autres cultures dans l'ensemble du Delta du Nil. Ce modèle de l'évapotranspiration réelle fonctionne avec un pas de temps d'une journée et utilise l'approche de Penman-Monteith qui tient compte de la spécificité d'un couvert. Les variables d'entrée du modèle sont la donnée météorologique standard issue des stations météorologiques du réseau national. Nous avons comparé les doses d'irrigation appliquées à l'orangeraie (I=994,30 mm.an-1 ; 2,72 mm.jour-1 ; le coefficient cultural Ea/EP=0,78) avec les besoins en eau issus du modèle (Eacalculée) pour proposer une gestion quotidienne de l'irrigation plus économe en eau. Les pertes en eau (drainage hors de la zone racinaire) sont de 94,570 m3 d'eau an-1 pour l'ensemble de la plantation de 80 ha, soit 1,182 m3 d'eau an-1 ha-1 (-12 %). Connaissant le coût élevé d'acheminement de l'eau vers les cultures, ces résultats peuvent être pris en compte dans l'aménagement hydraulique des sites de production

    Ressources en eau et changement climatique en région méditerranéenne

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    Structure-function-dynamics relationships in the peculiar Planktothrix PCC7805 OCP1: impact of his-tagging and carotenoid type

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    The orange carotenoid protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection. Here, we report on the functional, spectral and structural characteristics of the peculiar Planktothrix PCC7805 OCP (Plankto-OCP). We show that this OCP variant is characterized by higher photoactivation and recovery rates, and a stronger energy-quenching activity, compared to other OCPs studied thus far. We characterize the effect of the functionalizing carotenoid and of his-tagging on these reactions, and the time scales on which these modifications affect photoactivation. The presence of a His-tag at the C-terminus has a large influence on photoactivation, thermal recovery and PBS-fluorescence quenching, and likewise for the nature of the carotenoid that additionally affects the yield and characteristics of excited states and the ns-s dynamics of photoactivated OCP. By solving the structures of Plankto-OCP in the ECN- and CAN-functionalized states, each in two closely-related crystal forms, we further unveil the molecular breathing motions that animate Plankto-OCP at the monomer and dimer levels. We finally discuss the structural changes that could explain the peculiar properties of Plankto-OCP. - Complete functional characterization of Synechocystis and Planktothrix OCPs - Hitherto unknown structures of ECN- and CAN-functionalized Planktothrix OC

    Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae)

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    220 páginas, 5 figuras, 1 tabla.[EN] This adaptation text reproduces Anexo I of the dissertation “Results”: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771[ES] Este artículo es una adaptación del Anexo I de la tesis doctoral: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771Taxonomic and ecological interest in squat lobsters has grown considerably over the last two decades. A checklist of the 870 current valid species of squat lobsters of the world (families Chirostylidae, Galatheidae and Kiwaidae) is presented. The compilation includes the complete taxonomic synonymy and geographical distribution of each species plus type information (type locality, repository and registration number). The numbers of described species in the world’s major ocean basins are summarised.Peer reviewe

    Morphology of the megalopa of the mud crab, Rhithropanopeus harrisii (Gould, 1841) (Decapoda, Brachyura, Panopeidae), identified by DNA barcode.

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    The morphology of the megalopa stage of the panopeid Rhithropanopeus harrisii is redescribed and illustrated in detail from plankton specimens identified by DNA barcode (16S mtDNA) as previous descriptions do not meet the current standard of brachyuran larval description. Several morphological characters vary widely from those of other panopeid species which could cast some doubt on the species’ placement in the same family. Besides, some anomalous megalopae of R. harrisii were found among specimens reared at the laboratory from zoeae collected in the plankton. These anomalous morphological features are discussed in terms of problems associated with laboratory rearing conditions

    Effects of urban green infrastructure (UGI) on local outdoor microclimate during the growing season

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    This study analyzed how the variations of plant area index (PAI) and weather conditions alter the influence of urban green infrastructure (UGI) on microclimate. To observe how diverse UGIs affect the ambient microclimate through the seasons, microclimatic data were measured during the growing season at five sites in a local urban area in The Netherlands. Site A was located in an open space; sites B, C, and D were covered by different types and configurations of green infrastructure (grove, a single deciduous tree, and street trees, respectively); and site E was adjacent to buildings to study the effects of their façades on microclimate. Hemispherical photography and globe thermometers were used to quantify PAI and thermal comfort at both shaded and unshaded locations. The results showed that groves with high tree density (site B) have the strongest effect on microclimate conditions. Monthly variations in the differences of mean radiant temperature (∆Tmrt) between shaded and unshaded areas followed the same pattern as the PAI. Linear regression showed a significant positive correlation between PAI and ∆Tmrt. The difference of daily average air temperature (∆Ta) between shaded and unshaded areas was also positively correlated to PAI, but with a slope coefficient below the measurement accuracy (±0.5 °C). This study showed that weather conditions can significantly impact the effectiveness of UGI in regulating microclimate. The results of this study can support the development of appropriate UGI measures to enhance thermal comfort in urban areas
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