17 research outputs found

    Finding guidelines for cabbage intercropping systems design as a first step in a meta-analysis relay for vegetables

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    Modern agriculture has been focused on optimizing production, neglecting supporting and regulating ecosystem services. Meta-analyses have demonstrated the potential of intercropping to deliver multiple ecosystem services. However, guidelines for the design and management of such systems remain unclear, especially for the understudied vegetable-based intercropping systems. Given the diversity of vegetable crops, we propose a ‘relay’ of classical crop-specific meta-analyses to capitalize on vegetable intercropping research. Each ‘leg’ in the relay analyzes the effects of companion crops on a focal crop, and over the course of subsequent legs, the network of interactions among the different crops is built. In this study we start what we aspire to be the meta-analysis relay, focusing on cabbage (Brassica oleracea ssp.) and the delivery of the provisioning services Productivity, Product Quality (grade and pest injury in cabbage products), and Yield Stability across different companion species, spatio-temporal configurations, and management practices. We identified 76 studies from all inhabited continents across 81 field sites, comprising 892 data records, of which 689 remained after cleaning. We show that intercropping reduced cabbage productivity (−7% on average, P < 0.05) but also pest injury (−48%, P < 0.001) relative to sole cabbage systems. Cabbage grade on the contrary was not significantly improved by intercropping (+1%, P = 0.71). Effects on yield stability varied widely as only few data records were available from trials conducted over more than two years, pointing to the need for longer-term experimentation. Greater productivity was associated with companion species with a low growth habit or types sown at or after planting of the cabbage crop thus limiting competition with cabbage at early development stages. The decrease in pest injuries was associated with intercropping patterns involving strong inter-plant interactions (i.e., mixed, row, and additive) and companion species that supported biodiversity such as living mulches. Overall, beneficial effects of intercropping tended to be more evident in organic production systems, possibly because synthetic inputs may have hidden regulating effects. Cabbage growers and agricultural advisors can use these guidelines when designing intercrop systems specific to their needs. Applying the approach to other crops and agro-ecosystem services as part of the proposed meta-analysis relay will foster comprehensive understanding of vegetable intercropping systems interactions

    Ca NMR investigation in bi-based high-Tc cuprates

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    As a first step of a study of the electronic properties of CuO2 planes by probing calcium nuclei in the Bi-based high-Tc materials, we report here the structural assignment of Ca NMR lines measured in 43Ca-enriched powders of n = 2 ((Bi, Pb)2Sr2CaCu2O8+x) et n = 3 ((Bi, Pb)2Sr2Ca2Cu3O10+y). Pour le site principal du calcium (Ca entre deux plans CuO2) bismuth compounds. For the main calcium site (Ca between two CuO2 planes) we could determine the quadrupolar as well as the shift parameters

    Si-O-Si Angle Distribution in Amorphous Silica Characterized by EXAFS Multiple Scattering Calculations

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    EXAFS-Multiple Scattering (MS) calculations has been performed to characterize the second shell of neighbours around silicon in amorphous silica. To render the large Si-O-Si angle distribution, a combination of three regular [(Si(OSi)4] structural models covering the 130 to 160° angle range is used in the calculations

    O Knight shifts of the various types of CuO

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    A 17O NMR study has been performed on a 17O enriched powder sample of (Bi, Pb)2Sr2Ca2Cu3Oy, also called n = 3 phase (with Tc = 110K) which belongs to the Bi-based superconductors family (Bi, Pb)2Sr2Can-1CunO2n+4 The n = 3 compound which contains in its unit cell two types of CuO2 planes (labelled type I and II), Is compared to the n = 2 compound where only one type of CuCO2 planes (type I) is present. 17O Knight shift measurements versus temperature, in the normal phase, have allowed us to evidence the distinct behaviours of the two types of planes present in the n = 3 compound. The results are consistent with the existence of stronger electron correlations, or smaller charge carrier density in the type II planes

    Infections and multiple sclerosis: Recommendations from the French Multiple Sclerosis Society

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    International audienceIntroduction: Viral, bacterial, or fungal infections are suspected of triggering multiple sclerosis (MS) and promoting relapses of the disease and are likely to be promoted by immune-active treatments. This raises questions about the infectious workup and preventive treatment of these infections prior to their initiation.Objectives: To establish recommendations on infections and MS. Provide information to patients and healthcare professionals on the minimal infectious workup to be performed in an MS patient at diagnosis and prior to initiation of immuno-active therapy in MS.Methods: The recommendation attempts to answer four main questions about infections and MS. The French Group for Recommendations in Multiple Sclerosis (France4MS) did a systematic review of articles from PubMed and universities databases (from January 1975 to June 2020), using the RAND/UCLA formalized consensus method. The RAND/UCLA method has been developed to synthesize the scientific literature and expert opinions on health care topics and was used for reaching a formal agreement. Twenty-three experts contributed to the detailed review and a group of 63 multidisciplinary health professionals validated the final version of 36 recommendations.Results: It is recommended that MS patients undergo a minimal infectious workup, check their vaccination status at diagnosis, and repeat it during follow-up and before starting immunotherapy. Screening and preventive treatment of viral (group Herpes virus, HPV, JCV, HCV, HBV), bacterial (mycobacteria) and fungal (Cryptococcus) infections is recommended prior to the initiation of certain immuno-active MS therapies.Discussion and conclusions: At diagnosis of MS and prior to the choice of therapeutic strategy, it is recommended to update the vaccination schedule of MS patients in reference to the HCSP vaccination schedule and the SFSEP recommendations. Before starting immunosuppressive treatment, it is recommended to inform patients of the risks of infections and to look for a constitutive or acquired immune deficiency. Health professionals and patients should be informed of the updated recommendations on infections and MS
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