AfSBT Congress abstracts Zimbabwe 2014: Epidemiology of hepatitis B virus infection in Africa

No Abstrac

Roughness of sandstone fracture surfaces: Profilometry and shadow length investigations

The geometrical properties of fractured sandstone surfaces were studied by measuring the length distribution of the shadows appearing under grazing illumination. Three distinct domains of variation were found: at short length scales a cut-off of self-affinity is observed due to the inter-granular rupture of sandstones, at long length scales, the number of shadows falls off very rapidly because of the non-zero illumination angle and of the finite roughness amplitude. Finally, in the intermediate domain, the shadow length distribution displays a power law decrease with an exponent related to the roughness exponent measured by mechanical profilometry. Moreover, this method is found to be more sensitive to deviations from self-affinity than usual methods

Collectivités territoriales et transports publics urbains dans les Etats de l'Union européenne

L'organisation politico-administrative infra-étatique (nombre de niveaux, autonomie politique et de gestion)conditionne largement l'organisation des transports urbains.Dans une première partie,l'auteur brosse une synthèse comparative de l'organisation des collectivitésterritoriales dans les 15 pays de l'union européenne, les détails concernant chaque Etat étant reportés dans uneannexe.En seconde partie, l'organisation des transports urbains de ces mêmes pays est analysée, en insistantparticulièrement sur les rapports entre "autorités organisatrices" et transporteurs.En guise de conclusion, l'auteur livre quelques réflexions sur quelques unes des difficultés à résoudre et desévolutions possibles, probables ou certaines

Moving on from voluntary nonremunerated donors: who is the best blood donor

Summary Blood transfusion safety in sub-Saharan Africa (SSA) is marred by the high prevalence of infectious agents, chronic blood shortage and lack of resources. However, considerable pressure is applied by richer countries and international transfusion bodies to establish voluntary, non-remunerated blood donors (VNRD) as the only source of blood, excluding the traditional family/replacement donors on the grounds of a higher level of safety. Such a policy increases the cost of a unit of blood by two to fivefold and exacerbates the pre-existing blood shortage. This review provides compelling evidence that first-time VNRD are no safer than family/replacement donors and that only repeat donation provides improved blood safety. In order to limit blood shortage and maintain affordability of the blood supply in SSA, both types of donors should be accepted and both should be encouraged to donate regularly

Inactivation of Plasmodium falciparum in whole blood by riboflavin plus irradiation.

BACKGROUND: Malaria parasites are frequently transmitted by unscreened blood transfusions in Africa. Pathogen reduction methods in whole blood would thus greatly improve blood safety. We aimed to determine the efficacy of riboflavin plus irradiation for treatment of whole blood infected with Plasmodium falciparum. STUDY DESIGN AND METHODS: Blood was inoculated with 10(4) or 10(5) parasites/mL and riboflavin treated with or without ultraviolet (UV) irradiation (40-160 J/mL red blood cells [mL(RBCs)]). Parasite genome integrity was assessed by quantitative amplification inhibition assays, and P. falciparum viability was monitored in vitro. RESULTS: Riboflavin alone did not affect parasite genome integrity or parasite viability. Application of UV after riboflavin treatment disrupted parasite genome integrity, reducing polymerase-dependent amplification by up to 2 logs (99%). At 80 J/mL(RBCs), riboflavin plus irradiation prevented recovery of viable parasites in vitro for 2 weeks, whereas untreated controls typically recovered to approximately 2% parasitemia after 4 days of in vitro culture. Exposure of blood to 160 J/mL(RBCs) was not associated with significant hemolysis. CONCLUSIONS: Riboflavin plus irradiation treatment of whole blood damages parasite genomes and drastically reduces P. falciparum viability in vitro. In the absence of suitable malaria screening assays, parasite inactivation should be investigated for prevention of transfusion-transmitted malaria in highly endemic areas

The Determination of Optimal Fines in Cartel Cases The Myth of Underdeterrence

The determination of optimal fines to deter the formation or continuation of cartels is a major objective of competition policy. We provide an analysis of static and dynamic frameworks to characterize the restitution and deterrence properties of fines: cartel stability depends on their ability to prevent deviation by firms, while the benefit of a deviation depends on the fines to be imposed in case of detection by the antitrust authority. We show that the proper consideration of the dynamics of competition has a major impact on the determination of optimal dissuasive fines: our results suggest that a clear majority of fines imposed by the European Commission in recent years meet the deterrence objective

The Determination of Optimal Fines in Cartel Cases - The Myth of Underdeterrence

The determination of optimal fines to deter the formation or continuation of cartels is a major objective of competition policy. We provide an analysis of static and dynamic frameworks to characterize the restitution and deterrence properties of fines: cartel stability depends on their ability to prevent deviation by firms, while the benefit of a deviation depends on the fines to be imposed in case of detection by the antitrust authority. We show that the proper consideration of the dynamics of competition has a major impact on the determination of optimal dissuasive fines: our results suggest that a clear majority of fines imposed by the European Commission in recent years meet the deterrence objective. La détermination d’amendes optimales pour dissuader la formation ou la poursuite des cartels est au cœur des politiques de concurrence. Nous définissons un cadre stratégique pour caractériser le caractère restitutif et dissuasif des amendes dans des contextes statique et dynamique : la stabilité d’un cartel dépend de sa capacité à prévenir les déviations dont la profitabilité est fonction des amendes imposées lorsque le cartel est découvert. Nous montrons que la prise en compte appropriée de la dynamique de la concurrence a un impact majeur sur la détermination des amendes dissuasives optimales : nos résultats suggèrent qu’une nette majorité des amendes infligées par la Commission Européenne ces dernières années rencontrent l'objectif de dissuasion.Optimal fines, cartels, Amendes optimales, cartels

Detection of Brucellae in peripheral blood mononuclear cells for monitoring therapeutic efficacy of brucellosis infection.

BACKGROUND: Brucellosis is one of the most severe widespread zoonoses caused by the Gram-negative bacterium Brucella species. The diagnosis and clinical assessment of human brucellosis are very important for the management of patients, while there is a lack of effective methods to detect Brucellae. Classical culture of Brucella species is time consuming and often fails. A simple and sensitive assay is needed for diagnosis of Brucella infection and monitoring of treatment in man. METHODS: Blood samples and peripheral blood mononuclear cells (PBMCs) were collected from 154 patients hospitalized for brucellosis. Brucella antibodies were detected by Rose Bengal Plate Test (RBPT), Standard Tube Agglutination Test (SAT) and enzyme-linked immunosorbent assay (ELISA). Intracellular Brucellae were detected by blood culture and immunofluorescence staining (IFS). RESULTS: Among 154 brucellosis patients, 59.7% (92/154) were antibody reactive by RBPT, 81.8% (126/154) by SAT and 95.5% (147/154) by ELISA, respectively. Only 3.2% (5/154) of patient blood samples resulted in positive Brucella culture, while 68.8% (106/154) carried IFS detectable Brucella antigens in PBMCs. Gender (P = 0.01) but not age (P > 0.05) was a significant risk factor. The frequency of intracellular Brucella antigens was similar between patients receiving different treatment regimens (P > 0.05). However, a significant decrease of intracellular Brucellae was observed only in patients with acute brucellosis after the third course of treatment (P < 0.05), suggesting that current regimens to treat chronic brucellosis were not effective. CONCLUSIONS: IFS appears a sensitive assay for detection of Brucella antigens in PBMCs and could be used for diagnosis and therapeutic monitoring of brucellosis in clinical practice

Dispersion enhancement and damping by buoyancy driven flows in 2D networks of capillaries

The influence of a small relative density difference on the displacement of two miscible liquids is studied experimentally in transparent 2D networks of micro channels. Both stable displacements in which the denser fluid enters at the bottom of the cell and displaces the lighter one and unstable displacements in which the lighter fluid is injected at the bottom and displaces the denser one are realized. Except at the lowest mean flow velocity U, the average $C(x,t)$ of the relative concentration satisfies a convection-dispersion equation. The dispersion coefficient is studied as function of the relative magnitude of fluid velocity and of the velocity of buoyancy driven fluid motion. A model is suggested and its applicability to previous results obtained in 3D media is discussed

Marmoset Viral Hepatic Inflammation Induced by Hepatitis C Virus Core Protein via IL-32.

Common marmosets infected with GB virus-B (GBV-B) chimeras containing hepatitis C virus (HCV) core and envelope proteins (CE1E2p7) developed more severe hepatitis than those infected with HCV envelope proteins (E1E2p7), suggesting that HCV core protein might be involved in the pathogenesis of viral hepatitis. The potential role of HCV core in hepatic inflammation was investigated. Six individual cDNA libraries of liver tissues from HCV CE1E2p7 or E1E2p7 chimera-infected marmosets (three animals per group) were constructed and sequenced. By differential expression gene analysis, 30 of 632 mRNA transcripts were correlated with the immune system process, which might be associated with hepatitis. A protein-protein interaction network was constituted by STRING database based on these 30 differentially expressed genes (DEGs), showing that IL-32 might play a central regulatory role in HCV core-related hepatitis. To investigate the effect of HCV core protein on IL-32 production, HCV core expressing and mock constructs were transfected into Huh7 cells. IL-32 mRNA and secretion protein were detected at significantly higher levels in cells expressing HCV core protein than in those without HCV core expression (P < 0.01 and P < 0.001, respectively). By KEGG enrichment analysis and using the specific signaling pathway inhibitor LY294002 for inhibition of PI3K, IL-32 expression was significantly reduced (P < 0.001). In conclusion, HCV core protein induces an increase of IL-32 expression via the PI3K pathway in hepatic cells, which played a major role in development of HCV-related severe hepatitis