171 research outputs found

    CONTRIBUTION AU DESIGN, STABILITÉ, PERFORMANCE ET OPTIMISATION D’UN UAV

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    Ce travail porte sur la simulation numérique, l’étude de performance, la stabilité et l’optimisation d’un modèle de drone (PIPER CUB J3).Dans ce but plusieurs logiciels de conception et de dessin assisté par ordinateur ont été utilisés : le modèle de l’UAV est conçu sous le logiciel « SolidWorks », les étapes de maillage et résolution des équations de Navier-Stokes décrivant l’écoulement sous « Ansys 16.0 », l’étude de stabilité et performance de vol par « Advanced Anlysis Aircraft 2.5 ».Pour des fins d’optimisation et d’amélioration en termes de finesse et d’endurance, trois types d’ailette ont été étudié

    Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste

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    Abstract: In this study, it was observed that in experimental work under laboratory scale using conventional biochemical methane potential (BMP) assay, the loading rate ratio 4:1 had optimum biodegradability rate than other ratios which were investigated, while the loading rate ratio of 1:1 had optimum biogas and methane yield after 15 days hydraulic retention time. It was concluded that chicken waste (CM) monodigestion has higher biodegradability rate compare to organic fraction municipality solid waste (OFMSW) mono-digestion. Co-digestion of OFMSW and CM stabilizes conditions in digestion process such as carbon to nitrogen (C:N) ratio in the substrate mixtures as well as macro and micronutrients, pH, inhibitors or toxic compounds, dry matter and thus increasing biogas production. It was concluded that the organic waste generated in the municipal landfills could be co-digested with CM to produce methane which can be used as a source of environmentally friendly and clean energy for the transport sector, industries and residential homes

    Sestrins induce natural killer function in senescent-like CD8(+) T cells

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    Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8⁺ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27⁻CD28⁻CD8⁺ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D-DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27⁻CD28⁻CD8⁺ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27⁻CD28⁻CD8⁺ T cells to acquire a broad-spectrum, innate-like killing activity

    Inhibition of Enterovirus 71 (EV-71) Infections by a Novel Antiviral Peptide Derived from EV-71 Capsid Protein VP1

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    Enterovirus 71 (EV-71) is the main causative agent of hand, foot and mouth disease (HFMD). In recent years, EV-71 infections were reported to cause high fatalities and severe neurological complications in Asia. Currently, no effective antiviral or vaccine is available to treat or prevent EV-71 infection. In this study, we have discovered a synthetic peptide which could be developed as a potential antiviral for inhibition of EV-71. Ninety five synthetic peptides (15-mers) overlapping the entire EV-71 capsid protein, VP1, were chemically synthesized and tested for antiviral properties against EV-71 in human Rhabdomyosarcoma (RD) cells. One peptide, SP40, was found to significantly reduce cytopathic effects of all representative EV-71 strains from genotypes A, B and C tested, with IC50 values ranging from 6–9.3 µM in RD cells. The in vitro inhibitory effect of SP40 exhibited a dose dependent concentration corresponding to a decrease in infectious viral particles, total viral RNA and the levels of VP1 protein. The antiviral activity of SP40 peptide was not restricted to a specific cell line as inhibition of EV-71 was observed in RD, HeLa, HT-29 and Vero cells. Besides inhibition of EV-71, it also had antiviral activities against CV-A16 and poliovirus type 1 in cell culture. Mechanism of action studies suggested that the SP40 peptide was not virucidal but was able to block viral attachment to the RD cells. Substitutions of arginine and lysine residues with alanine in the SP40 peptide at positions R3A, R4A, K5A and R13A were found to significantly decrease antiviral activities, implying the importance of positively charged amino acids for the antiviral activities. The data demonstrated the potential and feasibility of SP40 as a broad spectrum antiviral agent against EV-71

    Consensus Middle East and North Africa Registry on Inborn Errors of Immunity

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    Background: Inborn errors of immunity (IEIs) are a heterogeneous group of genetic defects of immunity, which cause high rates of morbidity and mortality mainly among children due to infectious and non-infectious complications. The IEI burden has been critically underestimated in countries from middle- and low-income regions and the majority of patients with IEI in these regions lack a molecular diagnosis. Methods: We analyzed the clinical, immunologic, and genetic data of IEI patients from 22 countries in the Middle East and North Africa (MENA) region. The data was collected from national registries and diverse databases such as the Asian Pacific Society for Immunodeficiencies (APSID) registry, African Society for Immunodeficiencies (ASID) registry, Jeffrey Modell Foundation (JMF) registry, J Project centers, and International Consortium on Immune Deficiency (ICID) centers. Results: We identified 17,120 patients with IEI, among which females represented 39.4%. Parental consanguinity was present in 60.5% of cases and 27.3% of the patients were from families with a confirmed previous family history of IEI. The median age of patients at the onset of disease was 36 months and the median delay in diagnosis was 41 months. The rate of registered IEI patients ranges between 0.02 and 7.58 per 100,000 population, and the lowest rates were in countries with the highest rates of disability-adjusted life years (DALY) and death rates for children. Predominantly antibody deficiencies were the most frequent IEI entities diagnosed in 41.2% of the cohort. Among 5871 patients genetically evaluated, the diagnostic yield was 83% with the majority (65.2%) having autosomal recessive defects. The mortality rate was the highest in patients with non-syndromic combined immunodeficiency (51.7%, median age: 3.5 years) and particularly in patients with mutations in specific genes associated with this phenotype (RFXANK, RAG1, and IL2RG). Conclusions: This comprehensive registry highlights the importance of a detailed investigation of IEI patients in the MENA region. The high yield of genetic diagnosis of IEI in this region has important implications for prevention, prognosis, treatment, and resource allocation

    Autophagy acts through TRAF3 and RELB to regulate gene expression via antagonism of SMAD proteins

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    Macroautophagy can regulate cell signalling and tumorigenesis via elusive molecular mechanisms. We establish a RAS mutant cancer cell model where the autophagy gene ATG5 is dispensable in A549 cells in vitro, yet promotes tumorigenesis in mice. ATG5 represses transcriptional activation by the TGFβ-SMAD gene regulatory pathway. However, autophagy does not terminate cytosolic signal transduction by TGFβ. Instead, we use proteomics to identify selective degradation of the signalling scaffold TRAF3. TRAF3 autophagy is driven by RAS and results in activation of the NF-κB family member RELB. We show that RELB represses TGFβ target promoters independently of DNA binding at NF-κB recognition sequences, instead binding with SMAD family member(s) at SMAD-response elements. Thus, autophagy antagonises TGFβ gene expression. Finally, autophagy-deficient A549 cells regain tumorigenicity upon SMAD4 knockdown. Thus, at least in this setting, a physiologic function for autophagic regulation of gene expression is tumour growth

    Informe de la campaña ARGELIA0204 para la evaluación de recursos demersales en las costas de Argelia (Mediterráneo sud-occidental)

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    RESUMEN: Del 5 de Febrero al 8 de Marzo de 2004 se llevó a cabo la campaña de prospección pesquera con arrastre de fondo ARGELIA0204 en aguas de Argelia, a bordo del B/O Vizconde de Eza. Se realizaron 114 pescas (6 nulas) entre 40 y 760 m de profundidad. Se presentan los resultados de las capturas realizadas en esta campaña y se analizan los índices de abundancia y biomasa de las especies más importantes, así como su distribución de tallas, por sector geográfico y estrato batimétrico. Se comparan los rendimientos y las tallas obtenidos con los de la campaña realizada en 2003 en la misma área y con otras campañas realizadas en el Mediterráneo.RÉSUME: Rapport de la campagne ARGELIA0204 portant évaluation des ressources demersaux des côtes Algériennes (Méditerranée sud-occidental).- Du 05 du Février au 8 du Mars 2004, s’est réalisée une campagne de prospection par chalutage du fond ARGELIA0204 des côtes Algériennes, a bord du B/O Vizconde de Eza. 114 traits de pêche (6 annulées) ont été effectue entre 40 et 800 m de profondeur. Les résultats des captures réalisées durant cette campagne et l’analyse des indices d’abondance et biomasse des espèces les plus importantes sont présentés, par secteur, par aire géographique et strate bathymétrique, ainsi que leurs distributions de tailles par secteur géographique et strate bathymétrique. Les rendements et les tailles obtenus ont fait l’objet d’une comparaison avec les autres campagnes réalisées dans la Méditerranée.ABSTRACT: Report of the ARGELIA0204 survey for the assessment of the deep-sea demersal resources off Algerian coast (south-western Mediterranean).- From 5 February to 8 March 2004 the bottom-trawl survey ARGELIA0204 was developed in waters off Argelia, on board R/V Vizconde de Eza. 114 hauls (6 null) were carried out between 40 and 800 m depth. The results on the captures obtained during this survey are shown and abundance and biomass indexes of the most important species are analyzed by geographic sector and area, and bathymetric stratum, as their size distribution by geographic sector and bathymetric stratum. Yields and sizes obtained are compared to those from other surveys carried out in the Mediterranea

    Inequities and their determinants in coverage of maternal health services in Burkina Faso

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    Background: Poor and marginalized segments of society often display the worst health status due to limited access to health enhancing interventions. It follows that in order to enhance the health status of entire populations, inequities in access to health care services need to be addressed as an inherent element of any effort targeting Universal Health Coverage. In line with this observation and the need to generate evidence on the equity status quo in sub-Saharan Africa, we assessed the magnitude of the inequities and their determinants in coverage of maternal health services in Burkina Faso. Methods: We assessed coverage for three basic maternal care services (at least four antenatal care visits, facility-based delivery, and at least one postnatal care visit) using data from a cross-sectional household survey including a total of 6655 mostly rural, poor women who had completed a pregnancy in the 24 months prior to the survey date. We assessed equity along the dimensions of household wealth, distance to the health facility, and literacy using both simple comparative measures and concentration indices. We also ran hierarchical random effects regression to confirm the presence or absence of inequities due to household wealth, distance, and literacy, while controlling for potential confounders. Results: Coverage of facility based delivery was high (89%), but suboptimal for at least four antenatal care visits (44%) and one postnatal care visit (53%). We detected inequities along the dimensions of household wealth, literacy and distance. Service coverage was higher among the least poor, those who were literate, and those living closer to a health facility. We detected a significant positive association between household wealth and all outcome variables, and a positive association between literacy and facility-based delivery. We detected a negative association between living farther away from the catchment facility and all outcome variables. Conclusion: Existing inequities in maternal health services in Burkina Faso are likely going to jeopardize the achievement of Universal Health Coverage. It is important that policy makers continue to strengthen and monitor the implementation of strategies that promote proportionate universalism and forge multi-sectoral approach in dealing with social determinants of inequities in maternal health services coverage
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