134 research outputs found

    Influence du changement climatique sur la diversité inter et intra-spécifique des plantes cultivées à Tougou au nord du Burkina Faso

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    L’objectif de l’étude est d’évaluer la diversité taxonomique et la variabilité inter et intra-spécifique des plantes cultivées non spontanées dans un contexte de changement climatique. Les données sont collectées à l’aide d’une enquête au près de 75 producteurs menée suivant des interviews semi-structurées. Les résultats ont révélé l’existence de 122 écotypes appartenant à 49 espèces, 39 genres et 22 familles. La diversité interspécifique représentait 73% de la diversité des plantes cultivées au plan national. La variabilité intraspécifique était faible comparée à la variabilité au plan national. Elle était plus élevée chez les céréales et les cultures potagères pluviales avec 2 à 10 écotypes par espèce contre 1 à 3 écotypes par espèce chez les cultures maraîchères. Les écotypes ayant un cycle de plus de 90 jours représentant 10,5% de l’ensemble des écotypes recensés, sont menacés de disparition à cause du changement climatique. Une stratégie de collecte, de conservation, d’amélioration et de promotion de ces ressources ainsi que la restauration des écosystèmes dégradés s’avèrent nécessaire pour le maintien de la phytodiversité cultivée.Mots clés: Burkina Faso, agro biodiversité, écotype, espèces menacées, conservatio

    Thermostable DNA Polymerase from a Viral Metagenome Is a Potent RT-PCR Enzyme

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    Viral metagenomic libraries are a promising but previously untapped source of new reagent enzymes. Deep sequencing and functional screening of viral metagenomic DNA from a near-boiling thermal pool identified clones expressing thermostable DNA polymerase (Pol) activity. Among these, 3173 Pol demonstrated both high thermostability and innate reverse transcriptase (RT) activity. We describe the biochemistry of 3173 Pol and report its use in single-enzyme reverse transcription PCR (RT-PCR). Wild-type 3173 Pol contains a proofreading 3′-5′ exonuclease domain that confers high fidelity in PCR. An easier-to-use exonuclease-deficient derivative was incorporated into a PyroScript RT-PCR master mix and compared to one-enzyme (Tth) and two-enzyme (MMLV RT/Taq) RT-PCR systems for quantitative detection of MS2 RNA, influenza A RNA, and mRNA targets. Specificity and sensitivity of 3173 Pol-based RT-PCR were higher than Tth Pol and comparable to three common two-enzyme systems. The performance and simplified set-up make this enzyme a potential alternative for research and molecular diagnostics

    Comparative Proteomic Analysis of Serum from Patients with Systemic Sclerosis and Sclerodermatous GVHD. Evidence of Defective Function of Factor H

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    BACKGROUND: Systemic sclerosis (SSc) is an autoimmune disease characterized by immunological and vascular abnormalities. Until now, the cause of SSc remains unclear. Sclerodermatous graft-versus-host disease (ScGVHD) is one of the most severe complications following bone marrow transplantation (BMT) for haematological disorders. Since the first cases, the similarity of ScGVHD to SSc has been reported. However, both diseases could have different etiopathogeneses. The objective of this study was to identify new serum biomarkers involved in SSc and ScGVHD. METHODOLOGY: Serum was obtained from patients with SSc and ScGVHD, patients without ScGVHD who received BMT for haematological disorders and healthy controls. Bi-dimensional electrophoresis (2D) was carried out to generate maps of serum proteins from patients and controls. The 2D maps underwent image analysis and differently expressed proteins were identified. Immuno-blot analysis and ELISA assay were used to validate the proteomic data. Hemolytic assay with sheep erythrocytes was performed to evaluate the capacity of Factor H (FH) to control complement activation on the cellular surface. FH binding to endothelial cells (ECs) was also analysed in order to assess possible dysfunctions of this protein. PRINCIPAL FINDINGS: Fourteen differentially expressed proteins were identified. We detected pneumococcal antibody cross-reacting with double stranded DNA in serum of all bone marrow transplanted patients with ScGVHD. We documented higher levels of FH in serum of SSc and ScGVHD patients compared healthy controls and increased sheep erythrocytes lysis after incubation with serum of diffuse SSc patients. In addition, we observed that FH binding to ECs was reduced when we used serum from these patients. CONCLUSIONS: The comparative proteomic analysis of serum from SSc and ScGVHD patients highlighted proteins involved in either promoting or maintaining an inflammatory state. We also found a defective function of Factor H, possibly associated with ECs damage

    Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis

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    Objective: Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained. / Methods: A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twenty‐four clinical and serologic variables were used for clustering. / Results: Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement. / Conclusion: Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis

    A LIXISOL MICROBIAL ACTIVITY UNDER URBAN WASTES COMPOSTS EFFECT IN DONSIN, BURKINA FASO

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    <p>Mineralization causes soil carbon loss. This study focuses soil microbial activity measurement in relation with the application of six types of composts in sorghum three-year experiment. Composts were applied single or combined with urea. Organic carbon content, microbial biomass, respirometry and carbon global mineralization rate were evaluated. In comparison to the control, single composts treatments parameters variation rates ranged from -1 to +71%. When composts were combined with urea, parameters variations rates ranged from -8 to +107%. Under single urea, these parameters variation rates ranged from -14% to +31%. Best composts seemed to be those produced with various and balanced composting materials. Eco-friendly composts adoption could improve soil organic carbon content for sustainable microbial process.</p

    Clinical images: Recurrence of sarcoidosis heralded by bullous reaction within tribal scarification

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    The patient was a 44-year-old Ghanaian woman with a 5-year history of histologically proven sarcoidosis with pulmonary, mediastinum lymph node, liver, and joint involvement. She had been treated with prednisone at an initial dosage of 25 mg/day, which resulted in clinical remissio
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