Functionally Distinct Subpopulations of CpG-Activated Memory B Cells

During the human B cell (Bc) recall response, rapid cell division results in multiple Bc subpopulations. The TLR-9 agonist CpG oligodeoxynucleotide, combined with cytokines, causes Bc activation and division in vitro and increased CD27 surface expression in a sub-population of Bc. We hypothesized that the proliferating CD27lo subpopulation, which has a lower frequency of antibody-secreting cells (ASC) than CD27hi plasmablasts, provides alternative functions such as cytokine secretion, costimulation, or antigen presentation. We performed genome-wide transcriptional analysis of CpG activated Bc sorted into undivided, proliferating CD27lo and proliferating CD27hi subpopulations. Our data supported an alternative hypothesis, that CD27lo cells are a transient pre-plasmablast population, expressing genes associated with Bc receptor editing. Undivided cells had an active transcriptional program of non-ASC B cell functions, including cytokine secretion and costimulation, suggesting a link between innate and adaptive Bc responses. Transcriptome analysis suggested a gene regulatory network for CD27lo and CD27hi Bc differentiation

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

VIH, migraciones y derechos humanos : perspectivas internacionales

Las enfermedades son manifestaciones que sobrepasan la biología y el individuo, reflejando aspectos e implicaciones socioculturales. La infección por el VIH/SIDA es un caso paradigmático de localización social de la enfermedad y de cómo ésta nos interpela no sólo individualmente sino también a escala de la vida colectiva, como miembros de grupos, sociedades y Estados fundados sobre determinados cuadros de normas y valores. Es precisamente en esta dimensión colectiva que se sitúa la discusión propuesta en este libro, presentando un aporte teórico crítico e interdisciplinar, desde las ciencias sociales, sobre las transformaciones causadas por la globalización y por las políticas neoliberales, y su impacto particular en las cuestiones de género, migración e infección por el VIH en países y grupos poblacionales más vulnerables a la epidemia