546 research outputs found

    French lag in scientific research on organic farming: a scientometric approach

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    France suffers from a large research deficit in most areas related to sustainable development and public health. The case of research on organic farming, within the framework of the broader sector of agronomic research, constitutes a largely under-investigated field. Even if the demand for organic products is rapidly growing in Europe, research in this field still suffers from a lack of funding and researchers. A bibliometric analysis based on key words from scientific publications (in English only) taken from Thomson Scientific’s ISI Web of Science reference database made it possible to determine sufficiently relevant indicators for a comparison of national research efforts from 2000-2006, and to therefore assess actual research priorities in the area of organic farming. Beyond traditional specialisation analyses, the ratio between the world share of publications of a given country in organic farming and its world share of publications in specific disciplines and sub-disciplines (according to the nomenclature of the French Observatory for Sciences and Techniques) allowed us to obtain these prioritisation indexes that act as policy and priority (or prioritisation activity) indicators for research institutions involved in the concerned area. An index above 1 indicates an over-specialisation, whereas an index below 1 indicates an under-specialisation. For the period 2000-2006, the European Union obtained a specialisation index of 1.52 in the area of organic farming, compared to 0.68 for the US, 0.98 for Brazil and 0.18 for China. However, this seemingly satisfactory average for Europe as a whole hides important disparities between European countries. Moreover, France is at the very end of the classification for all indexes with only 0.47 specialisation, compared to Germany with 1.19, Italy with 1.39, Austria with 2.78, Sweden with 3.99, Finland with 4.46 and Denmark with 12.19. The prioritisation index for organic farming in comparison to the discipline, “Applied biology and ecology”, is 1.65 for the EU27, 0.69 for the US, 1.7 for Germany, 3.98 for Austria, 3.84 for Finland, 9.45 for Denmark and 0.49 for France. In comparison to the subdiscipline, “Agriculture, plant biology” the index is 1.5 for the EU27, 0.98 for the US, 1.61 for Germany, 3.28 for Austria, 1.52 for Finland, 9.79 for Denmark, and 0.41 for France. Finally, for the sub-discipline, “Agro-food”, it is 1.86 for the EU27, 0.73 for the US, 1.98 for Germany, 6.92 for Austria, 7.39 for Finland, 9.39 for Denmark and 0.58 for France. These results confirm that research on organic farming is largely under-prioritised in France. The French national research effort is therefore far from meeting the ecological and economic challenges facing agriculture in the 21st century

    Professional training and participatory research: Combined actions for developing organic rice farming in the Camargue region of France

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    In 2006 and 2007, INRA’s Joint Research Unit, Innovation, was a partner in a European professional training project within the framework of the Leonardo da Vinci programme. The objective of this project was to help develop organic rice farming in the major European rice-growing regions where rice is mainly cultivated in ecologically-sensitive areas. In France, the rate of conversion to organic production is much lower that what would be expected, since organic rice farming presents particular technical problems. The availability of expert support is critical to successful conversion and no structured training was available in the past. This is the reason why we developed a participatory training method that helps rice growers and stakeholders to convert to organic farming and to improve their organic rice production. Different training sessions were organised. The participants shared their thoughts about technical problems encountered and identified possible solutions. Some of the topics developed were weeds, soils and fertility, and varieties. At the end of these sessions, a motivated workgroup was set up. Some of its members even proposed to assess the efficiency of some of the techniques that were discussed during the work sessions in fields on their own farms. Furthermore, field visits were organised in the Camargue region of France and in Spain. Scientists and group members hope to be able to continue to work together after the O.R.P.E.S.A. project is over. In order to make this possible, we are now planning to initiate new research and development actions using the same approach

    Establishing references to optimise organic fertilisation in organic rice farming in the Camargue region of France

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    The mineralization rate of a commercial organic fertiliser was evaluated over the course of three years in an organic rice field in the Camargue (France). The effect of different mounts of fertiliser applied at different periods was tested. The organic fertiliser rapidly mineralised under flooded conditions. On the basis of this result, we demonstrated that an adaptation of organic fertilisation practices, similar to those employed for mineral fertilisers, would result in the optimisation of organic fertilisers, leading to improved profitability

    Transfer Functions and Penetrations of Five Differential Mobility Analyzers for Sub-2 nm Particle Classification

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    The transfer functions and penetrations of five differential mobility analyzers (DMAs) for sub-2 nm particle classification were evaluated in this study. These DMAs include the TSI nanoDMA, the Caltech radial DMA (RDMA) and nanoRDMA, the Grimm nanoDMA, and the Karlsruhe-Vienna DMA. Measurements were done using tetra-alkyl ammonium ion standards with mobility diameters of 1.16, 1.47, and 1.70 nm. These monomobile ions were generated by electrospray followed by high resolution mobility classification. Measurements were focused at an aerosol-to-sheath flow ratio of 0.1. A data inversion routine was developed to obtain the true transfer function for each test DMA, and these measured transfer functions were compared with theory. DMA penetration efficiencies were also measured. An approximate model for diffusional deposition, based on the modified Gormley and Kennedy equation using an effective length, is given for each test DMA. These results quantitatively characterize the performance of the test DMAs in classifying sub-2 nm particles and can be readily used for DMA data inversion

    Production de références pour optimiser la fertilisation organique en riziculture biologique camarguaise (France)

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    La vitesse de minéralisation d’un engrais organique commercial a été évaluée durant trois années dans une rizière biologique en Camargue (France). L’effet de différentes doses d’engrais apportées à différentes périodes a été testé. En conditions inondées, l’engrais organique minéralise rapidement. Sur la base de ce résultat, nous montrons qu’une adaptation des pratiques de fertilisation organique, inspirée de celles appliquées pour des engrais minéraux, permet une meilleure valorisation des engrais organiques, découlant sur une meilleure rentabilité

    Obstacles, levers and impacts of organic farming development in Camargue

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    We are presenting an analysis of the obstacles and levers for the development of organic cropping systems in Camargue, documented with a multicriteria analysis of scenarios of organic farming (OF) development. This communication is built using results from on-farm agronomic monitoring, stakeholders and farmers’ interviews and the use of models for integrated assessment of scenarios. At the farm level, the obstacles are related to identification of profitable cropping systems and rotations that include enough rice, conversion being therefore risky as impacting financial management and requiring a labour reorganisation. At the regional level, the constraints are related to the absence of advisory services for technical issues, and to the lack of coordination among the different stakeholders, to the low incentive of the public policies to convert, and to a relatively opaque organization of the supply chains. At the regional level, we analysed the consequences of two scenarios related to OF development on criteria such as the rice surface area, the quantity and quality of water, energy consumption or the employment generated. These results are expected to contribute to the definition of an action plan about OF development by the local stakeholders

    UVA-induced cyclobutane pyrimidine dimers in DNA: a direct photochemical mechanism?

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    International audienceThe carcinogenic action of UVA radiation is commonly attributed to DNA oxidation mediated by endogenous photosensitisers. Yet, it was recently shown that cyclobutane pyrimidine dimers (CPD), well known for their involvement in UVB genotoxicity, are produced in larger yield than oxidative lesions in UVA-irradiated cells and skin. In the present work, we gathered mechanistic information on this photoreaction by comparing formation of all possible bipyrimidine photoproducts upon UVA irradiation of cells, purified genomic DNA and dA20:dT20 oligonucleotide duplex. We observed that the distribution of photoproducts, characterized by the sole formation of CPD and the absence of (6-4) photoproducts was similar in the three types of samples. The CPD involving two thymines represented 90% of the amount of photoproducts. Moreover, the yields of formation of the DNA lesions were similar in cells and isolated DNA. In addition, the effect of the wavelength of the incident photons was found to be the same in isolated DNA and cells. This set of data shows that UVA-induced cyclobutane pyrimidine dimers are formed via a direct photochemical mechanism, without mediation of a cellular photosensitiser. This is possible because the double-stranded structure increases the capacity of DNA bases to absorb UVA photons, as evidenced in the case of the oligomer dA20:dT20. These results emphasize the need to consider UVA in the carcinogenic effects of sunlight. An efficient photoprotection is needed that can only be complete by completely blocking incident photons, rather than by systemic approaches such as antioxidant supplementation

    Terrestrial groundwater and nutrient discharge along the 240-km-long Aquitanian coast

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    We collected samples from sea water, runnel water, beach pore waters, water from the unconfined surficial aquifer discharging at the beach face, groundwater, and rainwater from the Aquitanian coast in order to determine the flux of dissolved inorganic nitrogen (DIN), phosphorus and silica from terrestrial submarine groundwater discharge (SGD). The flux of fresh groundwater was obtained from a water balance calculation based on precipitation and evapotranspiration and assessment of the coastal watershed from hydrograph separation. Waters with intermediate salinities between sea water and freshwaters are found all along the 240-km-long coast, indicating that SGD is ubiquitous. The estimated fresh water flux is 2.25 m3 d− 1 m− 1 longshore. Terrestrial SGD provides a DIN flux of 9·106 mol each year to the adjacent coastal zone. This flux is about four times lower than the release of DIN due to tidally driven saline SGD. The freshwater DIN flux is low because the upland land use consists almost exclusively of pine forest. Dissolved organic nitrogen represents more than 60% of the total dissolved nitrogen flux. Dissolved iron, phosphorus and silica have much higher concentrations in the anoxic forest aquifer than in the fresh-water end-member of the subterranean estuary sampled in the upper beach aquifer. This suggests that the salinity gradient of the estuary does not correspond to a redox gradient. The redox front between anoxic groundwater and fresh oxic waters occurs below the soil-depleted foredune/yellow dune. Anoxic P- and Si-rich waters seep directly on the beach face only in the north Gironde, where the foredunes are eroded. This study reveals the role of the sandy foredune aquifer in biogeochemical fluxes from SGD, which is to dilute and oxidize waters from the unconfined surficial upland aquifer

    Radial velocities for the Hipparcos-Gaia Hundred-Thousand-Proper-Motion project

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    (abridged) The Hundred-Thousand-Proper-Motion (HTPM) project will determine the proper motions of ~113500 stars using a 23-year baseline. The proper motions will use the Hipparcos data, with epoch 1991.25, as first epoch and the first intermediate-release Gaia astrometry, with epoch ~2014.5, as second epoch. The expected HTPM proper-motion standard errors are 30-190 muas/yr, depending on stellar magnitude. Depending on the characteristics of an object, in particular its distance and velocity, its radial velocity can have a significant impact on the determination of its proper motion. The impact of this perspective acceleration is largest for fast-moving, nearby stars. Our goal is to determine, for each star in the Hipparcos catalogue, the radial-velocity standard error that is required to guarantee a negligible contribution of perspective acceleration to the HTPM proper-motion precision. We employ two evaluation criteria, both based on Monte-Carlo simulations, with which we determine which stars need to be spectroscopically (re-)measured. Both criteria take the Hipparcos measurement errors into account. For each star in the Hipparcos catalogue, we determine the confidence level with which the available radial velocity and its standard error, taken from the XHIP compilation catalogue, are acceptable. We find that for 97 stars, the radial velocities available in the literature are insufficiently precise for a 68.27% confidence level. We also identify 109 stars for which radial velocities are currently unknown yet need to be acquired to meet the 68.27% confidence level. To satisfy the radial-velocity requirements coming from our study will be a daunting task consuming a significant amount of spectroscopic telescope time. Fortunately, the follow-up spectroscopy is not time-critical since the HTPM proper motions can be corrected a posteriori once (improved) radial velocities become available.Comment: Accepted in A&
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