1,041 research outputs found

    Genetic diversity of african and worldwide strains of Ralstonia solanacearum as determined by PCR-Restriction Fragment Length Polymorphism analysis of the hrp gene region

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    The genetic diversity among a worldwide collection of 120 strains of #Ralstonia solanacearum# was assessed by restriction fragment length polymorphism (RFLP) analysis of amplified fragments from the hrp gene region. Five amplified fragments appeared to be specific to #R. solanacearum#. Fifteen different profiles were identified among the 120 bacterial strains, and a hierarchical cluster analysis distributed them into eight clusters. Each cluster included strains belonging to a single biovar, except for strains of biovars 3 and 4, which could not be separated. However, the biovar 1 strains showed rather extensive diversity since they were distributed into five clusters whereas the biovar 2 and the biovar 3 and 4 strains were gathered into one and two clusters, respectively. PCR-RFLP analysis of the #hrp# gene region confirmed the results of previous studies which split the species into an "Americanum" division including biovar 1 and 2 strains and an "Asiaticum" division including biovar 3 and 4 strains. However, the present study showed that most of the biovar 1 strains, originating from African countries (Reunion Island, Madagascar, Zimbabwe, and Angola) and being included in a separate cluster, belong to the "Asiaticum" rather than to the "Americanum" division. These African strains could thus have evolved separately from other biovar 1 strains originating from the Americas. (Résumé d'auteur

    Phenotypic diversity of Xanthomonas sp. mangiferaeindicae

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    Carbohydrate utilization profiles by means of the API (Appareils et Procédés d'Identification) system and sensitivity to antibiotics and heavy metal salts of 68 #Xanthomonas sp. mangiferaeindicae# strains isolated in nine countries from mango (#Mangifera indica L.#) and other genera of the #Anacardiaceae# were examined to assess the variability of the taxon. The strains could be separated into 10 groups according to Ward clustering. Apigmented strains isolated from the pepper tree [syn. Brazilian pepper] (#Schinus terebenthifolius Raddi#) could not be clearly differentiated from most apigmented strains isolated from mango. Yellow-pigmented strains isolated from mango in Brazil and Reunion Island, apigmented strains isolated from mango in Brazil and from ambarella in the French West Indies, clustered in distinct groups. The results are consistent with those of other studies, based on isozyme analysis of esterase, phosphoglucomutase and superoxide dismutase, and hrp-RFLP analysis; they indicate the need for a comprehensive taxonomic evaluation of xanthomonads associated with #Anacardiaceae#. (Résumé d'auteur

    Identification de l'agent responsable de la maladie des taches noires de la mangue (Mangifera indicae)

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    Une bactérie, Pseudomonas mangifera indicae, a été isolée de lésions sur mangues en provenance de la Réunion. Elle est responsable de la maladie des taches noires (black spot

    The role of economics in ecosystem based management:The case of the EU Marine Strategy Framework Directive; first lessons learnt and way forward

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    The EU Marine Strategy Framework Directive (MSFD) sets out a plan of action relating to marine environmental policy and in particular to achieving ‘good environmental status’ (GES) in European marine waters by 2020. Article 8.1 (c) of the Directive calls for ‘an economic and social analysis of the use of those waters and of the cost of degradation of the marine environment’. The MSFD is ‘informed’ by the Ecosystem Approach to management, with GES interpreted in terms of ecosystem functioning and services provision. Implementation of the Ecosystem Approach is expected to be by adaptive management policy and practice. The initial socio-economic assessment was made by maritime EU Member States between 2011 and 2012, with future updates to be made on a regular basis. For the majority of Member States, this assessment has led to an exercise combining an analysis of maritime activities both at national and coastal zone scales, and an analysis of the non-market value of marine waters. In this paper we examine the approaches taken in more detail, outline the main challenges facing the Member States in assessing the economic value of achieving GES as outlined in the Directive and make recommendations for the theoretically sound and practically useful completion of the required follow-up economic assessments specified in the MSFD

    Ultrastructure of interactions between Cassava and Xanthomonas campestris pv. manihotis : cytochemistry of cellulose and pectin degradation in a susceptible cultivar

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    A cytochemical investigation was carried out on the development of an aggressive strain of #Xanthomonas campestris pv. #manihotis, responsible for the cassava bacterial blight, to gain better insights into molecular and cellular mechanisms involved in leaf cell wall degradation by this pathogen. The use of anti-pectin monoclonal antibodies revealed that the plant middle lamellae were damaged during the infection process, from the epiphytic stage on the leaf surface to invasion of vascular bundles. In parallel, application of a beta-1,4-exoglucanase-gold probe to healthy and infected tissues indicated that primary and secondary cell walls were also altered. Quantitation of gold labeling confirmed that pectin was more severely degraded than cellulose. Accumulation of pectin-like compounds was also detected in occluded infected vessels. Bacterial-surrounding sheaths, which were routinely seen during pathogenesis early after leaf inoculation, had a dense or loosened fibrillar appearance and were differentiated from the pathogen cell wall. Close association occurred between extracellular fibrils and leaf cell walls, both at early and advanced stages of wall degradation. Bacterial extracellular sheaths were often seen deep in host cell walls, sometimes enclosing residual plant cell wall fragments. Our cytochemical data demonstrated that cell wall degradation of cassava by #Xanthomonas campestris pv. #manihotis plays an important role in host tissue colonization. It is also suggested that bacterial extracellular sheaths are involved in plant cell surface degradation. (Résumé d'auteur

    Assessing costs and benefits of measures to achieve good environmental status in European regional seas: challenges, opportunities, and lessons learnt

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    The EU Marine Strategy Framework Directive (MSFD) requires Member States to assess the costs and benefits of Programmes of Measures (PoMs) put in place to ensure that European marine waters achieve Good Environmental Status by 2020. An interdisciplinary approach is needed to carry out such an assessment whereby economic analysis is used to evaluate the outputs from ecological analysis that determines the expected effects of such management measures. This paper applies and tests an existing six-step approach to assess costs and benefits of management measures with potential to support the overall goal of the MSFD and discusses a range of ecological and economic analytical tools applicable to this task. Environmental cost-benefit analyses are considered for selected PoMs in three European case studies: Baltic Sea (Finland), East Coast Marine Plan area (UK), and the Bay of Biscay (Spain). These contrasting case studies are used to investigate the application of environmental cost-benefit analysis (CBA) including the challenges, opportunities and lessons learnt from using this approach. This paper demonstrates that there are opportunities in applying the six-step environmental CBA framework presented to assess the impact of PoMs. However, given demonstrated limitations of knowledge and data availability, application of other economic techniques should also be considered (although not applied here) to complement the more formal environmental CBA approach

    Extended thromboprophylaxis with betrixaban in acutely ill medical patients

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    BACKGROUND: Patients with acute medical illnesses are at prolonged risk for venous thrombosis. However, the appropriate duration of thromboprophylaxis remains unknown. METHODS: Patients who were hospitalized for acute medical illnesses were randomly assigned to receive subcutaneous enoxaparin (at a dose of 40 mg once daily) for 10±4 days plus oral betrixaban placebo for 35 to 42 days or subcutaneous enoxaparin placebo for 10±4 days plus oral betrixaban (at a dose of 80 mg once daily) for 35 to 42 days. We performed sequential analyses in three prespecified, progressively inclusive cohorts: patients with an elevated d-dimer level (cohort 1), patients with an elevated d-dimer level or an age of at least 75 years (cohort 2), and all the enrolled patients (overall population cohort). The statistical analysis plan specified that if the between-group difference in any analysis in this sequence was not significant, the other analyses would be considered exploratory. The primary efficacy outcome was a composite of asymptomatic proximal deep-vein thrombosis and symptomatic venous thromboembolism. The principal safety outcome was major bleeding. RESULTS: A total of 7513 patients underwent randomization. In cohort 1, the primary efficacy outcome occurred in 6.9% of patients receiving betrixaban and 8.5% receiving enoxaparin (relative risk in the betrixaban group, 0.81; 95% confidence interval [CI], 0.65 to 1.00; P=0.054). The rates were 5.6% and 7.1%, respectively (relative risk, 0.80; 95% CI, 0.66 to 0.98; P=0.03) in cohort 2 and 5.3% and 7.0% (relative risk, 0.76; 95% CI, 0.63 to 0.92; P=0.006) in the overall population. (The last two analyses were considered to be exploratory owing to the result in cohort 1.) In the overall population, major bleeding occurred in 0.7% of the betrixaban group and 0.6% of the enoxaparin group (relative risk, 1.19; 95% CI, 0.67 to 2.12; P=0.55). CONCLUSIONS: Among acutely ill medical patients with an elevated d-dimer level, there was no significant difference between extended-duration betrixaban and a standard regimen of enoxaparin in the prespecified primary efficacy outcome. However, prespecified exploratory analyses provided evidence suggesting a benefit for betrixaban in the two larger cohorts. (Funded by Portola Pharmaceuticals; APEX ClinicalTrials.gov number, NCT01583218.)

    Demons of the Anthropocene. Facing Bruno Latour’s Gaia

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    As proposed in 2012 by the 3th International Geological Congress, the Anthropocene is the geological epoch of the Quaternary Period following the Holocene, the age that accounts for the transformation of humans into a force shaping the Earth, and of human actions into a geological phenomenon. Current debates on the Anthropocene are introducing new figures of impersonality, modes of political agency that are shaking the certainties of modern political philosophy. A key protagonist of this epistemic turn is Gaia, the Earth, the Greek Mother of most western gods.As proposed in 2012 by the 3th International Geological Congress, the Anthropocene is the geological epoch of the Quaternary Period following the Holocene, the age that accounts for the transformation of humans into a force shaping the Earth, and of human actions into a geological phenomenon. Current debates on the Anthropocene are introducing new figures of impersonality, modes of political agency that are shaking the certainties of modern political philosophy. A key protagonist of this epistemic turn is Gaia, the Earth, the Greek Mother of most western gods

    A Futurist Art of the Past: Anton Giulio Bragaglia’s Photodynamism

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    The article examines "Un gesto del capo" (A gesture of the head), a 1911 “Photodynamic” picture by Anton Giulio Bragaglia (1890-1960), and discusses its Bergsonian motifs
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