101 research outputs found

    First Order Dominance Techniques and Multidimensional Poverty Indices:An Empirical Comparison of Different Approaches

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    In this empirically driven paper we compare the performance of two techniques in the literature of poverty measurement with ordinal data: multidimensional poverty indices and first order dominance techniques (FOD). Combining multiple scenario simulated data with observed data from 48 Demographic and Health Surveys around the developing world, our empirical findings suggest that the FOD approach can be implemented as a useful robustness check for ordinal poverty indices like the multidimensional poverty index (MPI; the United Nations Development Program's flagship poverty indicator) to distinguish between those country comparisons that are sensitive to alternative specifications of basic measurement assumptions and those which are not. To the extent that the FOD approach is able to uncover the socio-economic gradient that exists between countries, it can be proposed as a viable complement to the MPI with the advantage of not having to rely on many of the normatively binding assumptions that underpin the construction of the index

    Coronavirus Cell Entry Occurs through the Endo-/Lysosomal Pathway in a Proteolysis-Dependent Manner

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    Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs). Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV). Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion

    Characterization of asphaltic oil occurrences from the southeastern margin of the Basque-Cantabrian Basin, Spain

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    A geochemical investigation has been undertaken on biodegraded hydrocarbons in outcropping reservoirs of the south-eastern margin of the Basque-Cantabrian Basin (Álava sector). The aims of the study were the characterization of the geochemical features and biodegradation level of these hydrocarbons, and the evaluation of their resemblance to oils from the Ayoluengo onshore oil field by means of isotopic analyses and gas chromatography-mass spectrometry techniques. Most of the samples lack n-alkanes, isoprenoids, low molecular weight aromatic compounds, steranes, homohopanes, diasteranes and triaromatic steroids, whereas hexacyclic and heptacyclic alkanes appear as key compounds although some structures were not totally elucidated. Thermal maturity has been assessed with several parameters and a calculated-equivalent vitrinite reflectance value of around 0.8% was estimated. In addition, gammacerane content, diasterane-to-sterane ratio and C35 to C34 hopanes ratio suggest that the Álava oil shows were derived from a carbonate rock deposited in a reducing, water-stratified and possibly hypersaline environment. Isotopic signatures and other data confirmed that these hydrocarbons are not genetically related to the oils from Ayoluengo and, consequently, their origin is associated with a yet unknown source rock in the basin

    Characterization of asphaltic oil occurrences from the southeastern margin of the Basque-Cantabrian Basin, Spain

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    A geochemical investigation has been undertaken on biodegraded hydrocarbons in outcropping reservoirs of the south-eastern margin of the Basque-Cantabrian Basin (Álava sector). The aims of the study were the characterization of the geochemical features and biodegradation level of these hydrocarbons, and the evaluation of their resemblance to oils from the Ayoluengo onshore oil field by means of isotopic analyses and gas chromatography-mass spectrometry techniques. Most of the samples lack n-alkanes, isoprenoids, low molecular weight aromatic compounds, steranes, homohopanes, diasteranes and triaromatic steroids, whereas hexacyclic and heptacyclic alkanes appear as key compounds although some structures were not totally elucidated. Thermal maturity has been assessed with several parameters and a calculated-equivalent vitrinite reflectance value of around 0.8% was estimated. In addition, gammacerane content, diasterane-to-sterane ratio and C35 to C34 hopanes ratio suggest that the Álava oil shows were derived from a carbonate rock deposited in a reducing, water-stratified and possibly hypersaline environment. Isotopic signatures and other data confirmed that these hydrocarbons are not genetically related to the oils from Ayoluengo and, consequently, their origin is associated with a yet unknown source rock in the basin
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