2,821 research outputs found

    Europe vs. The United States: Is There a Trade-Off Between Mobility and Inequality?

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    This paper asses the scope of income mobility from a comparative perspective and explores if there is an observable relationship with inequality. More specifically, the main hypotheses to be tested are the existence of notable differences in mobility between the USA and the European Union which could offset the observed differences in inequality, the possible differences within the European Union and, finally, whether or not the factors which determine mobility differ greatly. To this end, a broad range of mobility indicators is used, their structure in each country is studied and the principal determinants are analyzed by means of different decomposition exercises.

    Critical phenomena of the Majority voter model in a three dimensional cubic lattice

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    In this work we investigate the critical behavior of the three dimensional simple-cubic Majority voter model. Using numerical simulations and a combination of two different cumulants we evaluated the critical point with a higher accuracy than the previous numerical result found by Yang et al. [J.- S. Yang, I.-M. Kim and W. Kwak, Phys. Rev. E 77, 051122 (2008)]. Using standard Finite Size Scaling theory and scaling corrections we find that the critical exponents {\nu}, {\gamma} and {\beta} are the same as those of the three dimensional Ising model.Comment: 5 pages, 5 figures. Accepted in PR

    Modulation of inflammation in transgenic models of Alzheimer's disease

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    Over the past decade the process of inflammation has been a focus of increasing interest in the Alzheimer's disease (AD) field, not only for its potential role in neuronal degeneration but also as a promising therapeutic target. However, recent research in this field has provided divergent outcomes, largely due to the use of different models and different stages of the disease when the investigations have been carried out. It is now accepted that microglia, and possibly astrocytes, change their activation phenotype during ageing and the stage of the disease, and therefore these are important factors to have in mind to define the function of different inflammatory components as well as potential therapies. Modulating inflammation using animal models of AD has offered the possibility to investigate inflammatory components individually and manipulate inflammatory genes in amyloid precursor protein and tau transgenics independently. This has also offered some hints on the mechanisms by which these factors may affect AD pathology. In this review we examine the different transgenic approaches and treatments that have been reported to modulate inflammation using animal models of AD. These studies have provided evidence that enhancing inflammation is linked with increases in amyloid-beta (Aβ) generation, Aβ aggregation and tau phosphorylation. However, the alterations on tau phosphorylation can be independent of changes in Aβ levels by these inflammatory mediators

    Measuring Spatial Dynamics in Metropolitan Areas

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    This paper introduces a new approach to measuring neighborhood change. Instead of the traditional method of identifying “neighborhoods†a priori and then studying how resident attributes change over time, our approach looks at the neighborhood more intrinsically as a unit that has both a geographic footprint and a socioeconomic composition. Therefore, change is identified when both as- pects of a neighborhood transform from one period to the next. Our approach is based on a spatial clustering algorithm that identifies neighborhoods at two points in time for one city. We also develop indicators of spatial change at both the macro (city) level as well as local (neighborhood) scale. We illustrate these methods in an application to an extensive database of time-consistent census tracts for 359 of the largest metropolitan areas in the US for the period 1990-2000.

    Differential contribution of PB1-F2 to the virulence of highly pathogenic H5N1 influenza A virus in mammalian and avian species

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    Highly pathogenic avian influenza A viruses (HPAIV) of the H5N1 subtype occasionally transmit from birds to humans and can cause severe systemic infections in both hosts. PB1-F2 is an alternative translation product of the viral PB1 segment that was initially characterized as a pro-apoptotic mitochondrial viral pathogenicity factor. A full-length PB1-F2 has been present in all human influenza pandemic virus isolates of the 20(th) century, but appears to be lost evolutionarily over time as the new virus establishes itself and circulates in the human host. In contrast, the open reading frame (ORF) for PB1-F2 is exceptionally well-conserved in avian influenza virus isolates. Here we perform a comparative study to show for the first time that PB1-F2 is a pathogenicity determinant for HPAIV (A/Viet Nam/1203/2004, VN1203 (H5N1)) in both mammals and birds. In a mammalian host, the rare N66S polymorphism in PB1-F2 that was previously described to be associated with high lethality of the 1918 influenza A virus showed increased replication and virulence of a recombinant VN1203 H5N1 virus, while deletion of the entire PB1-F2 ORF had negligible effects. Interestingly, the N66S substituted virus efficiently invades the CNS and replicates in the brain of Mx+/+ mice. In ducks deletion of PB1-F2 clearly resulted in delayed onset of clinical symptoms and systemic spreading of virus, while variations at position 66 played only a minor role in pathogenesis. These data implicate PB1-F2 as an important pathogenicity factor in ducks independent of sequence variations at position 66. Our data could explain why PB1-F2 is conserved in avian influenza virus isolates and only impacts pathogenicity in mammals when containing certain amino acid motifs such as the rare N66S polymorphism

    Innovating in a 4th course of Chemical Engineering: A Bolognese Recipe

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    In this article we analyze a case study conducted within a pilot innovation experience in an undergraduate course on Chemical Engineering. The study was developed during three years, 2005/06, 2006/07 y 2007/08, at the University of Valladolid (Spain). The main goal of this work is to show evidence to better understand the methodological changes promoted by the aforementioned pilot experience, as well as to reflect on whether or not this sort of innovations help to reach EHEA thorny demands. The methodological innovation carried out in the course was based on active learning methods, such as Project-based Learning, and the study of real cases from multiple perspectives and subjects
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