Improvements in Modeling 90 degree Bleed Holes for Supersonic Inlets

The modeling of porous bleed regions as boundary conditions in computational fluid dynamics (CFD) simulations of supersonic inlet flows has been improved through a scaling of sonic flow coefficient data for 90deg bleed holes. The scaling removed the Mach number as a factor in computing the sonic flow coefficient and allowed the data to be fitted with a quadratic equation, with the only factor being the ratio of the plenum static pressure to the surface static pressure. The implementation of the bleed model into the Wind-US CFD flow solver was simplified by no longer requiring the evaluation of the flow properties at the boundary-layer edge. The quadratic equation can be extrapolated to allow the modeling of small amounts of blowing, which can exist when recirculation of the bleed flow occurs within the bleed region. The improved accuracy of the bleed model was demonstrated through CFD simulations of bleed regions on a flat plate in supersonic flow with and without an impinging oblique shock. The bleed model demonstrated good agreement with experimental data and three-dimensional CFD simulations of bleed holes

New microsatellite markers for Dacryodes edulis (Burseraceae), an indigenous fruit tree species from Central Africa

Microsatellites were designed and characterized in the African fruit tree species Dacryodes edulis (Burseraceae). The fruits are commercialized throughout Central Africa and the species is present in forested environments as well as cultivated systems. The high variability of these markers makes them suitable to investigate the structure of genetic diversity in this important food tree species from Central Africa. From a genomic library obtained by next-generation sequencing, 21 new polymorphic microsatellite loci were developed. Tested on 95 individuals from four populations coming from three countries of the Congo Basin, the microsatellites displayed two to 20 alleles (mean 7.5; expected heterozygosity 0.003 to 0.937, mean 0.666). The transferability of microsatellites was effective for four other Dacryodes species (D. buettneri, D. igaganga, D. osika, D. pubescens). This set of newly developed microsatellite markers will be useful for assessing the genetic diversity and differentiation as well as gene flow patterns of D. edulis in tropical forests from Central Africa

Change in hepatitis C virus genotype in hemodialysis patients after end-of-treatment response to interferon monotherapy--relapse or re-infection?

Hepatitis C virus (HCV) infection remains common among hemodialysis patients and its occurrence is related mainly to nosocomial spread. Although dialysis patients with HCV infection respond well to interferon-based therapy, relapse is frequent. This study aimed at a selected group of hemodialysis patients infected with HCV infection undergoing interferon therapy who achieved end-of-treatment virological response but became HCV-RNA positive again 6 months after end-of-treatment. It was evaluated whether de novo HCV-RNA positivity in these non-sustained responders occurred due to lack of clearance of HCV after the initial response to interferon-alpha (relapse) or due to re-infection with a new strain (re-infection). Genotyping by Inno-LiPA and by phylogenetic tree analysis using partial HCV-NS5B sequences at two evaluation points: pre-treatment (T0) and 6 months after end-of-treatment (T18). Non-sustained responders (n = 15) carried subtypes 1a (8 patients), 1b (4 patients), 3a (2 patients), and 4a (1 patient) before treatment. Identical subtypes were detected in 10 patients at T18. Five patients changed genotypes at T18, suggesting nosocomial re-infection. This study emphasizes the importance of epidemiologic measures to control the re-exposure of hemodialysis patients treated previously for HCV infection.status: publishe