Identification of T-cell epitopes in the Hepatitis C virus genotype 4 proteome: a step towards epitope-driven vaccine development

Hepatitis C is an inflammatory infectious disease of the liver caused by the Hepatitis C Virus (HCV). It is a global pandemic, chronically inflicting 150 million people worldwide, with millions of new infections arising annually. The standard therapy of HCV is expensive, associated with severe side effects, and has variable success rates. Thus far, no HCV vaccine has been developed, owing to the challenges that faced and still face its development. Despite these challenges, several attempts have been taken to develop a vaccine, some of which have progressed to phase II clinical trials. Most of these attempts, however, have focused on HCV genotypes 1 and 2 as vaccine targets, and almost no attention has been given to HCV genotype 4 (HCV-4), the viral genotype most prevalent in the Middle East and Central Africa. In an attempt to fill this gap in HCV-4 vaccine research, this project describes the in silico identification of a group of highly conserved and immunogenic T-cell epitopes from the HCV-4 proteome, using the iVAX immunoinformatics toolkit (EpiVax Inc., RI, USA), as a first step towards the development of an epitope-driven vaccine against the viral genotype. Furthermore, it puts forth a fast and inexpensive method for the validation of the results retrospectively using the repository of empirical HCV immune epitope data on the Immune Epitope Database (IEDB). 90 HLA class I and 14 HLA class II epitopes were identified. From those, 20 HLA class I epitopes were found to be previously uncharacterized, while the in silico HLA binding predictions for 27 others (class I and class II) have been retrospectively validated. The retrospective validation results for 4 of the identified HLA class II epitopes were confirmed by a pilot HLA class II binding assay. Furthermore, an investigation of the conservancy of a selected set of the identified epitopes in newly re-sequenced HCV strains from the Egyptian population was performed. The identified and retrospectively validated set of epitopes constitutes a good target for further immunogenicity testing and epitope-driven vaccine development against HCV-4

Synthesis of Electromagnetic Metasurfaces: Principles and Illustrations

The paper presents partial overview of the mathematical synthesis and the physical realization of metasurfaces, and related illustrative examples. The synthesis consists in determining the exact tensorial surface susceptibility functions of the metasurface, based on generalized sheet transition conditions, while the realization deals with both metallic and dielectric scattering particle structures. The examples demonstrate the capabilities of the synthesis and realization techniques, thereby showing the plethora of possible metasurface field transmission and subsequent applications. The first example is the design of two diffraction engineering birefringent metasurfaces performing polarization beam splitting and orbital angular momentum multiplexing, respectively. Next, we discuss the concept of the "transistor" metasurface, which is an electromagnetic linear switch based on destructive interferences. Then, we introduce a non-reciprocal non-gyrotropic metasurface using a pick-up circuit radiator (PCR) architecture. Finally, the implementation of all-dielectric metasurfaces for spatial dispersion engineering is discussed

LES CONSÉQUENCES DE LA CRISE FINANCIÈRE DE 2008 SUR LA CRÉATION & LA RÉPARTITION DE LA VALEUR PARTENARIALE AU SEIN DES GRANDES ENTREPRISES EUROPÉENNES ?

L’objectif de cet article est double, mesurer l’incidence de la crise financière sur la création de la valeur partenariale et son appropriation par les parties prenantes explicites en Europe et proposer une typologie des secteurs les plus favorables en matière d’appropriation de la valeur partenariale par ces parties prenantes. Notre étude est fondée sur une base benchmark de 553 sociétés européennes réparties dans huit secteurs d’activités. Globalement, il ressort de cette recherche que la valeur partenariale créée en 2008 a augmenté de 13,1% par rapport à celle de 2006. En 2010 l’augmentation est de 4,9% par rapport à celle de 2008. En matière d’appropriation, les secteurs favorables aux bailleurs de fonds, aux salariés ainsi qu’à la firme sont les secteurs à forte intensité capitalistique et technologique. Les secteurs favorables aux clients sont ceux où les produits de substitution sont facilement disponibles et le coût de changement de fournisseur est relativement bas. Il ressort également que les fournisseurs disposent de plus de pouvoir de négociation dans les secteurs où le coût de changement de ces derniers est élevé à cause d’une marque forte ou de produits très différenciés. Cette étude fournit enfin un tableau de bord récapitulatif de l’appropriation de la valeur partenariale par les parties prenantes en Europe

Conjugal transfer of plasmids and antibiotic resistance among Escherichia coli isolated from animals in a rural area in Sarawak (Malaysia)

Thirty-six strains of Escherichia coli isolated from animals in Bario, a remote area in Sarawak, Malaysia, were examined for presence of plasmid DNA and their susceptibility to nine antimicrobial agents. Of the total 36 isolates, five bovine and six canine isolates were found to contain plasmid DNA ranging in sizes from 2.6 to 70 kilobases. All were susceptible to chloramphenicol, erythromycin, gentamicin, nalidixic acid and neomycin but resistance to ampicillin (47%), erythromycin (19%), streptomycin (25%) and tetracycline (11%) was observed. Resistance was associated with carriage of a 47 kb (SC98), 70 kb, (SC133) and 56 and 46 kb (SC119) plasmids which were transmissible to the Escherichia coli K12 recipient. It is concluded that animals form a potential reservoir of R plasmids carrying E. coli in the study area