411 research outputs found

    Les dispositifs enclos-exclos: une solution pour évaluer l'équilibre forêt-grande faune

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    Accord-cadre de recherche et de vulgarisation forestière

    Alejandro de la Sota’s modern villages: vernacular abstraction and surrealist modernity

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    Asked to implement General Franco’s ambitious “hydro-social dream” of modernization of the countryside, Falangist planners, engineers, and architects of the Instituto Nacional de Colonización (I.N.C.) developed a national strategy of “interior colonization” that, along with the reclamation of extensive regions, included the construction of302 modern pueblos between 1944 and 1970. Alejandro de la Sota (1913–1996) was one of the first five architects of the I.N.C. He designed Gimenells (1943), which set up the standards for the 1940s, and thenfour innovative villages: Esquivel (1952), Entrerríos (1954), Valuengoand La Bazana (1956). Based on research within the archives of the Fundación Alejandro de la Sota and the Ministry of Agriculture, this paper summarizes the modernity of his pueblos: the separation of traffic, the propagandistic concept of the open plaza, the volumetric abstraction ofthe vernacular house, and his ironic use (as understood by Ortega yGasset) of the Spanish classical. The research emphasizes how de la Sota transcended the functionalist elements of modernity in order to mobilize memories of the real and produce a “surreal” reality. In so doing,he reversed the fundamental reference to the countryside thatcharacterized Spanish surrealism to bring surrealism within the processof Franquist rural modernization

    Harmonized Growth Models and Simulations of the Evolution of Pure Stands of Norway spruce, Larches and Douglas-fir for Southern Belgium (Wallonia).

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    In order to compare different silvicultural scenarios we have undertaken the development of a software that can simulate stand evolution in regards to their species composition, site characteristics and silvicultural operations. As a first approach we limited the scope of our work to even-aged and pure coniferous stands of the three most important coniferous species in Wallonia (southern part of Belgium): Norway spruce (Picea abies), douglas-fir (Pseudotsuga menziensii) and larches (Larix sp.). This presentation introduces carried out simulations and compare their outcomes. First we gathered data sets from the permanent regional inventory, from observation networks and experimental plots throughout Wallonia. Then we adjusted, for these species, harmonized and distance-independent models of dominant-height growth, tree diameter growth, mortality, and the distribution of tree diameter frequency before the first thinning. Next we implemented those models in the Capsis platform, and we simulated, for the three species, the evolution of virtual stands using different scenarios. On one hand the evolution was performed without thinning, and on the other hand we applied silvicultural scenarios that are commonly used in Wallonia. As a result these models highlight, for example, the great juvenile growth and sensibility to stands density of larches whereas Norway spruce behaves the opposite. Further work is however needed to predict and simulate wood quality and value. Once this will be achieved we will attempt to optimize silvicultural scenarios for the three species.Accord cadre de recherche et vulgarisation forestières: ACTION 2.2.1. - CROISSANCE, PRODUCTIVITE ET SYLVICULTURE DU DOUGLAS, DE L'EPICEA COMMUN ET DES MELEZE

    A phase I pharmacokinetic study of hypoxic abdominal stop-flow perfusion with gemcitabine in patients with advanced pancreatic cancer and refractory malignant ascites

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    Purpose: As no curative treatment for advanced pancreatic and biliary cancer with malignant ascites exists, new modalities possibly improving the response to available chemotherapies must be explored. This phase I study assesses the feasibility, tolerability and pharmacokinetics of a regional treatment of gemcitabine administered in escalating doses by the stop-flow approach to patients with advanced abdominal malignancies (adenocarcinoma of the pancreas, n=8, and cholangiocarcinoma of the liver, n=1). Experimental design: Gemcitabine at 500, 750 and 1,125mg/m2 was administered to three patients at each dose level by loco-regional chemotherapy, using hypoxic abdominal stop-flow perfusion. This was achieved by an aorto-caval occlusion by balloon catheters connected to an extracorporeal circuit. Gemcitabine and its main metabolite 2′,2′-difluorodeoxyuridine (dFdU) concentrations were measured by high performance liquid chromatography with UV detection in the extracorporeal circuit during the 20min of stop-flow perfusion, and in peripheral plasma for 420min. Blood gases were monitored during the stop-flow perfusion and hypoxia was considered stringent if two of the following endpoints were met: pH≤7.2, pO2 nadir ratio ≤0.70 or pCO2 peak ratio ≥1.35. The tolerability of this procedure was also assessed. Results: Stringent hypoxia was achieved in four patients. Very high levels of gemcitabine were rapidly reached in the extracorporeal circuit during the 20min of stop-flow perfusion, with C max levels in the abdominal circuit of 246 (±37%), 2,039 (±77%) and 4,780 (±7.3%)μg/ml for the three dose levels 500, 750 and 1,125mg/m2, respectively. These C max were between 13 (±51%) and 290 (±12%) times higher than those measured in the peripheral plasma. Similarly, the abdominal exposure to gemcitabine, calculated as AUCt0-20, was between 5.5 (±43%) and 200 (±66%)-fold higher than the systemic exposure. Loco-regional exposure to gemcitabine was statistically higher in presence of stringent hypoxia (P<0.01 for C max and AUCt0-20, both normalised to the gemcitabine dose). Toxicities were acceptable considering the complexity of the procedure and were mostly hepatic; it was not possible to differentiate the respective contributions of systemic and regional exposures. A significant correlation (P<0.05) was found between systemic C max of gemcitabine and the nadir of both leucocytes and neutrophils. Conclusions: Regional exposure to gemcitabine—the current standard drug for advanced adenocarcinoma of the pancreas—can be markedly enhanced using an optimised hypoxic stop-flow perfusion technique, with acceptable toxicities up to a dose of 1,125mg/m2. However, the activity of gemcitabine under hypoxic conditions is not as firmly established as that of other drugs such as mitomycin C, melphalan or tirapazamine. Further studies of this investigational modality, but with bioreductive drugs, are therefore warranted first to evaluate the tolerance in a phase I study and later on to assess whether it does improve the response to chemotherap

    Identification of Genes Differentially Expressed in Response to Cold in Pisum sativum Using RNA Sequencing Analyses

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    International audienceLow temperature stress affects growth and development in pea (Pisum sativum L.) and decreases yield. In this study, RNA sequencing time series analyses performed on lines, Champagne frost-tolerant and Térèse frost-sensitive, during a low temperature treatment versus a control condition, led us to identify 4981 differentially expressed genes. Thanks to our experimental design and statistical analyses, we were able to classify these genes into three sets. The first one was composed of 2487 genes that could be related to the constitutive differences between the two lines and were not regulated during cold treatment. The second gathered 1403 genes that could be related to the chilling response. The third set contained 1091 genes, including genes that could be related to freezing tolerance. The identification of differentially expressed genes related to cold, oxidative stress, and dehydration responses, including some transcription factors and kinases, confirmed the soundness of our analyses. In addition, we identified about one hundred genes, whose expression has not yet been linked to cold stress. Overall, our findings showed that both lines have different characteristics for their cold response (chilling response and/or freezing tolerance), as more than 90% of differentially expressed genes were specific to each of them

    Monitoring selective logging intensities in central Africa with sentinel-1: A canopy disturbance experiment

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    peer reviewedForest degradation is a major threat to tropical forests, and effective monitoring using remotely sensed data is subject to significant challenges. In particular, consistent methods for detecting subtle changes in the forest canopy structure caused by selective logging are lacking. Here, using a unique dataset collected in southeastern Cameroon, covering over 22,000 ha of monthly harvesting areas, >6000 locations of harvested trees, and an independent canopy gap dataset developed from an uninhabited aerial vehicle flight (UAV; RGB camera) of approximately 1500 ha, a new method was designed to monitor canopy disturbance and logging intensity in Central Africa. Using Sentinel-1 synthetic aperture radar (SAR) data, the method was conceptualised using a twostep, two-scale approach, which better matched logging practices. First, (non-)harvesting activity areas were identified using textural indices at a spatial resolution of 300 m (step 1), and within these harvesting activity areas, canopy gaps were detected at a resolution of 10 m (step 2). Both steps were based on monthly differences in the Sentinel-1 SAR time series computed using the average of the 12 months preceding and the average of the three months following the month of interest. This method identified harvesting activity areas (step 1 at 300 m resolution) of over 12,004 km2 with high accuracy (omission and commission errors for both classes ≤0.05) and, within them, detected canopy gaps (step 2 at 10 m resolution) with a global accuracy of 0.89. Although some canopy gaps were subject to omission and commission errors (0.39 and 0.05, respectively), this method yielded better results than other available approaches. Compared to the UAV canopy gaps, this method detected most of the small gaps (≤ 500 m2), which represent 80% of all disturbed areas, whereas other available approaches missed at least 70% of these and consequently missed most of the disturbance events occurring in a selectively logged forest. Furthermore, the predictions were correlated with logging intensity, i.e., the number of trees and volume cut per hectare, which are two important criteria for assessing the sustainability of logging activities. This two-step two-scale method for short-term, monthly monitoring of logging disturbances and intensity has strong practical implications for forest administration and certification bodies in Central Africa.15. Life on land13. Climate action9. Industry, innovation and infrastructur

    Principes de base de la télédétection et ses potentialités comme outil de caractérisation de la ressource forestière – II. LiDAR aérien

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    La télédétection a déjà démontré, au travers de nombreuses études, son potentiel de caractérisation de la ressource forestière. En particulier, le développement du LiDAR aérien a ouvert la voie à de nouvelles perspectives. Cette technologie offre une vision tridimensionnelle de la forêt qui permet de récolter à large échelle des informations à l'intérieur même des peuplements. Après avoir présenté les grands principes de télédétection dans un premier article (Forêt Wallonne n°114), ce second volet présente quelques concepts de base pour se familiariser avec le LiDAR et illustre son intérêt pour la gestion des forêts et des milieux naturels aux travers de travaux de recherche menés sur une zone pilote constituée par le bassin versant de la Houille dans la région de Gedinne en Province de Namur

    Large-scale functional RNAi screen in C. elegans identifies genes that regulate the dysfunction of mutant polyglutamine neurons

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    <p>Abstract</p> <p>Background</p> <p>A central goal in Huntington's disease (HD) research is to identify and prioritize candidate targets for neuroprotective intervention, which requires genome-scale information on the modifiers of early-stage neuron injury in HD.</p> <p>Results</p> <p>Here, we performed a large-scale RNA interference screen in <it>C. elegans </it>strains that express N-terminal huntingtin (htt) in touch receptor neurons. These neurons control the response to light touch. Their function is strongly impaired by expanded polyglutamines (128Q) as shown by the nearly complete loss of touch response in adult animals, providing an <it>in vivo </it>model in which to manipulate the early phases of expanded-polyQ neurotoxicity. In total, 6034 genes were examined, revealing 662 gene inactivations that either reduce or aggravate defective touch response in 128Q animals. Several genes were previously implicated in HD or neurodegenerative disease, suggesting that this screen has effectively identified candidate targets for HD. Network-based analysis emphasized a subset of high-confidence modifier genes in pathways of interest in HD including metabolic, neurodevelopmental and pro-survival pathways. Finally, 49 modifiers of 128Q-neuron dysfunction that are dysregulated in the striatum of either R/2 or CHL2 HD mice, or both, were identified.</p> <p>Conclusions</p> <p>Collectively, these results highlight the relevance to HD pathogenesis, providing novel information on the potential therapeutic targets for neuroprotection in HD.</p
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