143 research outputs found

    Design and multicriteria evaluation of regionalized test cases in organic crops without animal production

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    What are the performances of different stockless organic crops systems? And more specifically, are there rotations more efficient than other for economic, technical and / or environmental criteria? This work aims to present the method of co-construction of simulated cases for an evaluation of economic, environmental and technical performances, at rotation and production system scale. Fifteen «test cases» have been defined in the partner regions of CASDAR projects ROTAB and ProtéAB and evaluated with a set of quantitative and non-aggregated indicators (tool Systerre ®). The results provided many references at different scales. In the current context, profitability was ensured for all cases studied, but the production environment had a major impact on the overall performance. Long rotations with multiannual crop rotation (often alfalfa), sometimes less economically efficient, had strong advantages regarding agricultural sustainability. They also seemed to be less sensitive to changes in economic conditions and provided that the crop harvest was performed by a company, (it requires less work time). The typical cases are upgradeable tools to be adapted to different simulations or prospective studies

    Clinico-pathological considerations in a 48-years-old female with acute kidney injury: is it lupus nephritis, ANCA-associated vasculitis or something else?

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    BACKGROUND: The value of ANCA positivity in the setting of systemic lupus erythematous and their pathogenicity remains uncertain. CASE PRESENTATION: We report the case of a 48-year-old female with rapidly progressive kidney failure, arthro-myalgia and weight loss. Auto-immune screening showed anti-dsDNA antibodies, complement consumption and triple ANCA positivity. A first kidney biopsy done at presentation highlighted class IV-G glomerulonephritis with elective extra-capillary involvement and mainly C1q glomerular deposition at immunofluorescence study. After three months of a regimen combining steroids and cyclophosphamide, a second biopsy was performed and showed class IV-G glomerulonephritis with mainly endocapillary proliferation. CONCLUSION: This case is atypical in view of immunological profile and kidney histopathological presentation and evolution and gives rise to discussion in view of recent data on ANCA value in lupus nephritis, and suggests that different auto-immune pathways may be involved in lupus nephritis

    KNOWING, CHARACTERIZING AND ASSESSING SYSTEMS OF ORGANIC CROP ROTATIONS

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    The choice of crop rotations in organic stockless cropping systems is the first leverage used to manage technical issues (to maintain soil fertility, to control pest and weeds) and economic issues (to insure income). The RotAB project (French Casdar funding 2008-2010) implemented complementary approaches to better knowing, characterizing and assessing arable crop rotations. Their conception depends on numerous factors such as the types of soil and climate (on which depend the types of crops, yield potential, possibility of mechanical weed control…) or the economic context (existence of outlets and continuity of markets). If nitrogen supply and weed control are the most important agronomic issues of organic farmers in stockless cropping systems, phosphorus availability appears to be the next important issue for soil fertility and system sustainability

    Les lombalgies chroniques : symptôme ou pas symptôme ?

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    Cet article étudie un aspect psychologique impliqué dans certaines affections somatiques, ici les lombalgies chroniques. Plusieurs cas de patients lombalgiques reçus en entretiens psychothérapiques montrent que le statut de la douleur évolue selon que le sujet lui accorde ou non une valeur de symptôme, au sens psychanalytique. Le « choix » de ce statut est personnel, subjectif, inconscient, et impacte l’évolution de la lombalgie. Après avoir défini le symptôme au sens médical et au sens psychanalytique, et avoir rappelé la distinction entre l’hystérie et la psychosomatique, les auteurs présentent leur conception des rapports corps et psyché selon le modèle de la bande de Möbius utilisée par Lacan pour définir les rapports entre le conscient et l’inconscient. Il est cependant illusoire, en médecine générale, de pouvoir amener tous les patients à faire de leur lombalgie un symptôme « psychanalytique ». Le contexte et le cadre ne sont pas les mêmes car le patient qui va consulter son médecin n’en attend pas la même chose que celui qui va consulter un psychologue, un psychanalyste ou un psychiatre. Néanmoins, l’ouverture des uns et des autres à la possibilité d’une évolution du patient fondée sur un changement de sa position subjective peut être un avantage important, car ce qui est en jeu dans le processus de la chronicisation n’est pas seulement la disparition pure et simple de la douleur, mais la modification préalable de sa fonction pour le sujet, c’est-à-dire le passage de la fonction première de la douleur comme signal de danger à celle qui favorise l’élaboration d’un sens subjectif. Et pour cela, faut-il encore que ce sujet, comme les praticiens concernés, lui reconnaissent cette seconde fonction

    OPTIMIZING AND PROMOTING MECHANICAL WEED CONTROL IN ARABLE CROPS

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    Within an overall strategy of weed flora management, mechanical weed control practices are complementary solutions to agronomic levers (crop rotation, tillage...) in weed control. Acquiring knowledge and communicating on the effectiveness of mechanical practices and tools appear essential. The "Mechanical Weed Control" project in France conducted between 2009 and 2012 made progress in this regard. The project shows that research activities are to be continued (experimentation, analysis of practices) and should be complemented by promotion that focuses on participatory approaches where farmers are involved in the implementation of these new practices

    Asymptotic behavior of oscillatory fractional processes

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    International audienceIn this paper we consider the antiderivative of the product of a fractional random process and a periodic function. We establish that the rescaled process constructed in this way converges to a Brownian motion whose variance depends on the frequency of the periodic function and the Hurst parameter. We also prove that for two different frequencies the limits are independent. Finally, we discuss applications to wave propagation in random media

    Early post-transplant serum IgA level is associated with IgA nephropathy recurrence after kidney transplantation

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    IgA nephropathy (IgAN), the most frequent primary glomerulonephritis, affects young patients and is associated with a high risk of progression to end-stage renal disease. Consequently, patients with IgAN constitute an important proportion of candidates for kidney transplantation. Several studies showed a significant risk of IgAN recurrence on kidney graft, but the risks factors for recurrence remain to be accurately evaluated. Indeed, early identification of at risk patients may allow the optimization of treatment and the reduction of recurrence rate on the graft. In the present work, we studied the relationship between post-transplant serum IgA (sIgA) levels and the risk of IgAN recurrence after kidney transplantation. Recipients with IgAN had higher levels of sIgA as compared to patients with other nephropathies (p<0.05). The prevalence of IgAN recurrence was 20.8% during the period of analysis (mean follow-up of 6 ± 3.2 years). Serum IgA levels at M6, M12 and M24 post-transplant were significantly higher in patients with IgAN recurrence as compared to those without (p = 0.009, p = 0.035 and p = 0.029, respectively). Using receiver operating curve (ROC), sIgA at M6 and M12 post-transplant were significantly associated with IgAN recurrence (AUC = 0.771, p = 0.004 and AUC = 0.767, p = 0.016, respectively), while serum creatinine and proteinuria were not. Serum IgA level at month 6 was significantly associated with the occurrence of post-transplant IgA recurrence, whether it was analyzed as a continuous or a categorical variable. After successive adjustment on age, gender and proteinuria, sIgA remained a significant risk factor of post-transplant IgAN recurrence. Finally, survival free of IgAN recurrence was significantly better in patients with sIgA<222 mg/dL at month 6 as compare to IgAN patients with sIgA≥222 mg/dL (p = 0.03). Thus, the present work supports a link between post-transplant sIgA levels and IgAN recurrence and suggests that sIgA may be a valuable predictive biomarker of IgAN recurrence in kidney transplant recipients

    Co-Designing an organic framework: the ”REF’AB” Project in France

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    To help the development of Organic Food and Farming (OFF) systems, there is the need to consolidate conversions to OF, to support entry into organic farming, and to develop existing organic farms. Therefore a group of extensionists, researchers and educators has being working 2 years long to co-design a framework for OFF, taking into account the need to (i) embrace all forms of OFF, and at the same time to (ii) address the specificities of OFF. This project, called REF’AB (REFerentiel de l’Agriculture Biologique, 2010-2012) aims at designing the organization of set of references produced on shared methodological bases. The approach consisted in identifying key-issues of OFF systems, defining indicators, identifying relevant databases and references to feed the framework, and providing recommendations for governance to optimise the establishment and circulation of references. The outcomes of this project is that first it was not necessarily clear what a framework for OFF should be, and therefore a conference of consensus was used as a methodological tool to share views by multi-stakeholders. Second, we used sustainability assessment as an integrative process of the three levels (technical-economic, environmental, and social) and third, to manage to share a more transversal approach, we proposed a framework with 3 levels of key-proprieties: 1) security and efficiency, 2) durability through the protection of resources, and 3) autonomy and resilience

    Pre-transplant CD45RC expression on blood T cells differentiates patients with cancer and rejection after kidney transplantation

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    Background Biological biomarkers to stratify cancer risk before kidney transplantation are lacking. Several data support that tumor development and growth is associated with a tolerant immune profile. T cells expressing low levels of CD45RC preferentially secrete regulatory cytokines and contain regulatory T cell subset. In contrast, T cells expressing high levels of CD45RC have been shown to secrete proinflammatory cytokines, to drive alloreactivity and to predict acute rejection (AR) in kidney transplant patients. In the present work, we evaluated whether pre-transplant CD45RClow T cell subset was predictive of post-transplant cancer occurrence. Methods We performed an observational cohort study of 89 consecutive first time kidney transplant patients whose CD45RC T cell expression was determined by flow cytometry before transplantation. Post-transplant events including cancer, AR, and death were assessed retrospectively. Results After a mean follow-up of 11.1±4.1 years, cancer occurred in 25 patients (28.1%) and was associated with a decreased pre-transplant proportion of CD4+CD45RChigh T cells, with a frequency below 51.9% conferring a 3.7-fold increased risk of post-transplant malignancy (HR 3.71 [1.24–11.1], p = 0.019). The sensibility, specificity, negative predictive and positive predictive values of CD4+CD45RChigh<51.9% were 84.0, 54.7, 89.8 and 42.0% respectively. Confirming our previous results, frequency of CD8+CD45RChigh T cells above 52.1% was associated with AR, conferring a 20-fold increased risk (HR 21.7 [2.67–176.2], p = 0.0004). The sensibility, specificity, negative predictive and positive predictive values of CD8+CD45RChigh>52.1% were 94.5, 68.0, 34.7 and 98.6% respectively. Frequency of CD4+CD45RChigh T cells was positively correlated with those of CD8+CD45RChigh (p<0.0001), suggesting that recipients with high AR risk display a low cancer risk. Conclusion High frequency of CD45RChigh T cells was associated with AR, while low frequency was associated with cancer. Thus, CD45RC expression on T cells appears as a double-edged sword biomarker of promising interest to assess both cancer and AR risk before kidney transplantation
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