Numerical homogenization methods for parabolic monotone problems

In this paper we review various numerical homogenization methods for monotone parabolic problems with multiple scales. The spatial discretisation is based on finite element methods and the multiscale strategy relies on the heterogeneous multiscale method. The time discretization is performed by several classes of Runge-Kutta methods (strongly A-stable or explicit stabilized methods). We discuss the construction and the analysis of such methods for a range of problems, from linear parabolic problems to nonlinear monotone parabolic problems in the very general Lp(W1,p) setting. We also show that under appropriate assumptions, a computationally attractive linearized method can be constructed for nonlinear problems

Détermination du débit de filtration glomérulaire au cours de la drépanocytose au Sénégal: Schwartz, Cockcroft et Gault, MDRD, CKD-EPI ou JSCCS ?

La détermination du Débit de Filtration Glomérulaire (DFG) est importante chez les drépanocytaires du fait qu’ils constituent un groupe de patients chez lesquels des atteintes rénales sont fréquemment décrites notamment l’hyperfiltration glomérulaire. Dès lors, à une époque où les calculateurs en ligne proposent simultanément différentes formules de détermination du DFG, il serait important d’évaluer au sein d’une population noire africaine drépanocytaire l’équivalence entre ces formules qui ont été développées et validées sur des populations caucasiennes et afro-américaines à DFG normal ou diminué. Ainsi cette étude avait pour but d’évaluer l’interchangeabilité des différentes formules de détermination du DFG en les appliquant à des drépanocytaires. Des enfants et adultes sénégalais drépanocytaires homozygotes ont été alors recrutés et leur DFG calculé. La fréquence de l’hyperfiltration glomérulaire et celle de l’insuffisance rénale ont été calculées à partir des résultats obtenus avec les formules de Schwartz et du CKD-EPI. La concordance des différentes formules a été évaluée avec la méthode Bland-Altman. Au total 56 adultes et 62 enfants ont été inclus dans l’étude. L’insuffisance rénale a été notée chez 1,78% des adultes et 9,68% des enfants ; l’hyperfiltration glomérulaire chez 66,10% des adultes et 25,8% des enfants. Par rapport aux formules de référence (CKD-EPI, Schwartz), tous les biais relevés étaient significativement différents de zéro à l’exception de celui de Cockcroftet Gault qui était statistiquement nul. Les limites de concordance étaient toutes inacceptablement larges par rapport aux limites attendues à l’exception de celles du CKD-EPI sans ajustement sur la race. Ainsi, la formule de Schwartz n’était pas interchangeable avec celle du JSCCS chez les enfants, tout comme celle du CKD-EPI ne l’était pas non plus avec celles du JSCCS, de Cockcroft, du MDRD ou du CKD-EPI sans ajustement sur la race chez les adultes drépanocytaires.   English title: Determination of glomerular filtration rate in sickle cell disease in Senegal: Schwartz, Cockcroft and Gault, MDRD, CKD-EPI or JSCCS? Determination of Glomerular Filtration Rate (GFR) is important in patients living with sickle cell disease (SCD) because they constitute a group of patients where kidney dysfunction is frequently described, in particular glomerular hyperfiltration. Therefore, at a time when online calculators simultaneously propose different formulas to estimate GFR, it would be important to evaluate in a black African population living with SCD the equivalence between these formulas which have been developed and validated on Caucasian and African American populations with normal or decreased GFR. Thus, the aim of this study was to evaluate interchangeability of different GFR formulas in a group of patients living with SCD. Homozygous Senegalese sickle cell children and adults were then recruited and their GFR computed using Schwartz and JSCCS in children, Cockcroft and Gault, CKD-EPI with and without adjustment for ethnicity, MDRD and JSCCS formulas in adults. The frequency of glomerular hyperfiltration and renal failure was computed based on the results generated using Schwartz and CKD-EPI formulas. The agreement between formulas was assessed with BlandAltman method. A total of 56 adults and 62 children were included in this study. Renal failure was observed in 1.78% of adults and 9.68% of children; glomerular hyperfiltration in 66.10% of adults and 25.8% of children. Compared with reference formulas (CKD-EPI, Schwartz), all biases found were significantly different from zero except for Cockcroft and Gault formula bias, which was statistically zero. The limits of agreement were all unacceptably wide compared with the expected limits with the exception of CKD-EPI without adjustment for ethnicity. Thus, Schwartz formula would not be interchangeable with JSCCS formula in children, nor was the CKD-EPI formula interchangeable with the JSCCS, Cockcroft and Gault, MDRD or CKD-EPI without adjustment for ethnicity formulas in adults living with sickle cell anemia

16S Metagenomic Comparison of Plasmodium falciparum–Infected and Noninfected Anopheles gambiae and Anopheles funestus Microbiota from Senegal

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Chilling, irradiation and transport of male Glossina palpalis gambiensis pupae: Effect on the emergence, flight ability and survival

International audienceBackground The sterile insect technique (SIT) requires mass-rearing of the target species, irradiation to induce sexual sterility and transportation from the mass-rearing facility to the target site. Those treatments require several steps that may affect the biological quality of sterile males. This study has been carried out to evaluate the relative impact of chilling, irradiation and transport on emergence rate, flight ability and survival of sterile male Glossina palpalis gambiensis. Results Chilling, irradiation and transport all affected the quality control parameters studied. The emergence rate was significantly reduced by long chilling periods and transport, i.e. from 92% at the source insectary in Burkina Faso to 78% upon arrival in Senegal. Flight ability was affected by all three parameters with 31% operational flies lost between the production facility and the destination site. Only survival under stress was not affected by any of the treatments. Conclusion The chilling period and transport were the main factors that impacted significantly the quality of sterile male pupae. Therefore, in the operational programme, the delivery of sterile male pupae was divided over two shipments per week to reduce the chilling time and improve the quality of the sterile males. Quality of the male pupae may further be improved by reducing the transport time and vibrations during transport

Risk factors for acquisition of meningococcal carriage in the African meningitis belt

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