Mycobacterium tuberculosis is the main aetiologic agent of tuberculosis, a disease of great concern in less‐developed regions. Apoptosis is a conspicuous event in macrophages infected in vitro with mycobacteria, a phenomenon also observed in vivo in granulomas of patients with tuberculosis. To determine its significance, it is important to define the mycobacterial moieties involved and how they cause apoptosis. Here we show that the 38‐kDa lipoprotein induces macrophage caspase‐dependent apoptosis involving TNF‐α and FasL and, interestingly, with the upregulation of cell‐death receptors TNFR1, TNFR2 and Fas. A role for the Toll‐like receptor 2 was also demonstrated. In conclusion, the ability to induce apoptosis of host cells is another property of the 38‐kDa lipoprotein, a molecule that has focused attention for being an immunodominant antigen that participates in phosphate transport.

We describe the association of caspase-dependent and caspase-independent mechanisms in macrophage apoptosis induced by LpqH, a 19 kDa Mycobacterium tuberculosis lipoprotein. LpqH triggered TLR2 activation, with upregulation of death receptors and ligands, which was followed by a death receptor signaling cascade with activation of initiator caspase 8 and executioner caspase 3. In this caspase-mediated phase, mitochondrial factors were involved in loss of mitochondrial transmembrane potential (ΔΨm), release of cytochrome c, and caspase 9 activation. Interestingly, a caspase-independent pathway was also identified; by immunoblot, the mitochondrial apoptosis inducing factor (AIF) was demonstrated in nuclei and cytosol of LpqH-treated macrophages. Confocal microscopy revealed translocation of AIF to the nuclei of the majority of apoptotic cells. These findings emphasize the complex and redundant nature of the macrophage death response to mycobacteria.

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The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description of internal structures that were not treated in previous works, allowing dose determination in different regions of the eye for a more adequate clinical analysis. Dose calculations were determined with the MCNP-4C Monte Carlo particle transport code running n parallel environment using PVM. The Amersham CKA4 ophthalmic applicator has been chosen and the depth dose distribution has been determined and compared to those provide by the manufacturer. The results have shown excellent agreement. Besides, absorbed dose values due to both 125I seeds and 60Co plaques were obtained for each one of the different structures which compose the eye model and can give relevant information in eventual clinical analyses.

The rupture of periodicity caused by one defect (defect layer) in a one-dimensional photonic crystal (1DPhC) results in a narrow transmission spectral line in the photonic band-gap, and the field distribution shows a strong confinement in the proximity of the defect layer. In this work, we present a theoretical model to calculate the frequency of defect modes caused by defect layers induced by localized mechanical stress. Two periodical arrangements were studied: one with layers of poly(methyl-methacrylate) (PMMA) and polystyrene (PS), PMMA-PS; the other with layers of PMMA and fused silica (SiO2), PMMA-SiO2. The defect layers were induced by localized compression (tension). The frequencies of the defect modes were calculated using elasto-optical theory and plane wave expansion and perturbation methods. Numerical results show that the frequency of the defect mode increases (decreases) when the compression (tension) increases. Based on the theoretical model developed, we show that compression of n layers of a 1DPhC induces n defect modes whose frequencies depend on the compression magnitude in the case of normal incidence of electromagnetic waves, in accordance with the results reported for other types of defect layers. The methodology shows the feasibility of the plane wave expansion and perturbation methods to study the frequency of the defect modes. Both periodical arrangements are suitable for designing mechanically tunable (1DPhC)-based narrow pass band filters and narrow reflectors in the (60, 65) THz range.

Le luxe est associé à l’excès mais aussi à la beauté et au plaisir. Il éveille souvent des réactions à la fois favorables et défavorables parmi les consommateurs, en particulier chez les jeunes ou millennials . Cette catégorie de la population, généralement négligée dans les études sur le luxe, représente pourtant un levier potentiel de croissance pour les marques de luxe. Par ailleurs, ce segment représente l’avenir dans le sens où il sera au cœur du marché du luxe des adultes de demain. Les enjeux sont donc importants. Ce segment des millennials pourrait en effet éprouver des sentiments d’ambivalence face à la décision d’acheter des produits de luxe et cela pourrait influencer son intention de faire des achats et de les reporter. L’impact de l’ambivalence sur ces variables est mal connu dans la littérature en marketing. En effet, les études sur les attitudes envers les produits et marques de luxe utilisent des échelles qui mesurent les attitudes favorables ou défavorables mais qui ne permettent pas aux consommateurs d’exprimer leur ambivalence. Afin d’expliquer comment l’ambivalence influe sur la décision d’acheter des produits de luxe, nous avons mené une enquête par questionnaire auprès de 143 étudiants français. Les résultats montrent que l’ambivalence a un double effet sur les intentions de ce nouveau segment de consommateurs : elle atténue l’intention d’achat par le biais de l’attitude, et favorise le report d’achat par le biais de la recherche d’informations.

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