On the stability of global solutions to Navier–Stokes equations in the space

AbstractWe show that the global solutions to the Navier–Stokes equations in R3 with data in VMO−1 which belong to the space defined by Koch and Tataru are stable, in the sense that they vanish at infinity (in time), that they depend analytically on their data, and that the set of Cauchy data giving rise to such a solution is open in the BMO−1 topology. We then study the case of more regular data

Time Scale Approach for Chirp Detection

International audienceTwo different approaches for joint detection and estimation of signals embedded in stationary random noise are considered and compared, for the subclass of amplitude and frequency modulated signals. Matched filter approaches are compared to time-frequency and time scale based approaches. Particular attention is paid to the case of the so-called " power-law chirps " , characterized by monomial and polynomial amplitude and frequency functions. As target application, the problem of gravitational waves at interferometric detectors is considered

Internet-based greenhouse climate choice to grow greenhouse tomatoes

* INRA Centre d'Avignon, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9 Diffusion du document : INRA Centre d'Avignon, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9International audienc

Modulation of competition between fruits and leaves by flower pruning and water fogging, and consequences on tomato leaf and fruit growth

International audienc

Effects of decreasing VPD by misting on leaf area and leaf inclination in tomato and estimation of consequences on light absorption

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Grow virtual tomatoes : two user friendly softwares for teaching the cultivation of greenhouse tomato

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Co-design of innovative periurban horticultural agroforestry systems in the south of France

PosterDesigning agricultural systems targeting an increase of natural regulations and a decrease of pest populations should be based on the optimization of various ecological services and biodiversity by modifying deeply the composition, structure and organization of agroecosystems. An agroforestry system combining fruit trees, vegetables and wild trees and shrubs is one possible option. Key challenges are to find out (i) a compromise between economic/technical constraints and ecological processes stimulating natural regulations and (ii) to test spatial combinations of vegetation. We explored the basic ecological principles necessary for the functioning of such cropping systems and elaborated an approach enabling the design and monitoring of complex horticultural agroforestry systems, at the level of a production unit. We present a co-design research project for a 4 ha pilot farm unit in the periurban area of Avignon, France (La Durette). We elaborated over two years different possible spatial arrangements and prototypes through participative discussions involving scientists, advisors and farmers. We progressively evaluated different combinations and ratios of fruit and vegetable production through calculation of expected yield, operational costs and income over ten years and through an expert evaluation of the labour time requirements. We also studied different possible spatial arrangements by modelling the impact of canopies on the available light for annual crops . This led to proposals for a sustainable and viable crop production system managed by 2 farmers. The different calculation tools could be further used to elaborate whole farm planning guides for horticultural agroforestry farms under temperate climate

Effets d'une exposition à la clothianidine sur les paramètres du liquide séminale de mâle d'abeilles

International audienceMany problems have been reported on honey bees colonies including fertility problems of queens resulted in production failure. Pesticides can be the cause of this failure in connection with the quality of sperm drone. Thus, the aim of this study was to assess the influence of exposure to syrup contaminated with clothianidin at 0.1 µg/L on semen parameters of drones. Results showed a significant decrease of semen volume and sperm concentration and an increase in sperm mortality rate. As for the energetic state, clothianidin increased cell redox potential, the ATP content of spermatozoa as well as the lactate dehydrogenase activity (LDH). It was concluded that exposure to clothianidin during the sexual maturity of drones could affect the semen quality.De nombreux problèmes ont été signalés sur les colonies d'abeilles domestiques, notamment des problèmes de fertilité des reines entraînant un échec de la production. Les pesticides peuvent être la cause de cet échec en relation avec la qualité du sperme des bourdons. Ainsi, le but de cette étude était d'évaluer l'influence de l'exposition au sirop contaminé par la clothianidine à 0,1 µg/L sur les paramètres du sperme des bourdons. Les résultats ont montré une diminution significative du volume du sperme et de la concentration en spermatozoïdes et une augmentation du taux de mortalité des spermatozoïdes. Quant à l'état énergétique, la clothianidine a augmenté le potentiel redox des cellules, la teneur en ATP des spermatozoïdes ainsi que l'activité de la lactate déshydrogénase (LDH). Il a été conclu que l'exposition à la clothianidine pendant la maturité sexuelle des bourdons pourrait affecter la qualité du sperme

Physiological effects of gamma irradiation in the honeybee, Apis mellifera

International audienceTerrestrial ecosystems are exposed to various kinds of pollutants, including radionuclides. The honeybee, Apis mellifera, is commonly used in ecotoxicology as a model species for evaluating the effects of pollutants. In the present study, honeybees were irradiated right after birth for 14 days with gamma rays at dose rates ranging between 4.38x10-3 and 588 mGy/d. Biological tissues (head, intestine and abdomen) were sampled at D3, D10 and D14. Ten different physiological markers involved in nervous (acetylcholinesterase (AChE)), antioxidative (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)), immune system (phenoloxidase (PO)) and metabolism (carboxylesterases (CaEs) and alkaline phosphatase (ALP)) were measured. Univariate analyses were conducted to determine whether each individual biomarker response was positively or negatively correlated with the dose rate. Then, multivariate analyses were applied to investigate the relationships between all the biomarker responses. Although no mortality occurred during the experiment, several biomarkers varied significantly in relation to the dose rate. Globally, the biomarkers of antioxidant and immune systems decreased as the dose rate increased. Reversible effects on the indicator of the neural system were found. Concerning indicators of metabolism (carboxylesterases), variations occurred but no clear pattern was found. Taken altogether, these results help better understand the effects of ionizing radiation on bees by identifying relevant physiological markers of effects. These results could improve the assessment of the environmental risk due to ionizing radiation in terrestrial ecosystems