334 research outputs found

    Desarrollo y corrupción

    Get PDF

    On the evolutionary origin of aging

    Get PDF
    It is generally believed that the first organisms did not age, and that aging thus evolved at some point in the history of life. When and why this transition occurred is a fundamental question in evolutionary biology. Recent reports of aging in bacteria suggest that aging predates the emergence of eukaryotes and originated in simple unicellular organisms. Here we use simple models to study why such organisms would evolve aging. These models show that the differentiation between an aging parent and a rejuvenated offspring readily evolves as a strategy to cope with damage that accumulates due to vital activities. We use measurements of the age-specific performance of individual bacteria to test the assumptions of the model, and find evidence that they are fulfilled. The mechanism that leads to aging is expected to operate in a wide range of organisms, suggesting that aging evolved early and repeatedly in the history of life. Aging might thus be a more fundamental aspect of cellular organisms than assumed so far

    Challenging assumptions of the enlargement literature : the impact of the EU on human and minority rights in Macedonia

    Get PDF
    This article argues that from the very start of the transition process in Macedonia, a fusion of concerns about security and democratisation locked local nationalist elites and international organisations intoa political dynamic that prioritised security over democratisation. This dynamic resulted in little progress in the implementation of human and minority rights until 2009, despite heavy EU involvement in Macedonia after the internal warfare of 2001. The effects of this informally institutionalised relationship have been overlooked by scholarship on EU enlargement towards Eastern Europe, which has made generalisations based on assumptions relevant to the democratisation of countries in Eastern Europe, but not the Western Balkans

    A Multidimensional Analytical Comparison of Remicade and the Biosimilar Remsima

    Get PDF
    In April 2016, the Food and Drug Administration approved the first biosimilar monoclonal antibody (mAb) – Inflectra/Remsima (Celltrion) based off the original product Remicade (infliximab, Janssen). Biosimilars promise significant cost savings for patients, but the unavoidable differences between innovator and copycat biologics raise questions regarding product interchangeability. In this study, Remicade and Remsima were examined by native mass spectrometry, ion mobility and quantitative peptide mapping. The levels of oxidation, deamidation and mutation of individual amino acids were remarkably similar. We found different levels of C-terminal truncation, soluble protein aggregates and glycation that all likely have a limited clinical impact. Importantly, we identified over 25 glycoforms for each product and observed glycoform population differences, with afucosylated glycans accounting for 19.7% of Remicade and 13,2% of Remsima glycoforms, which translated into a 2-fold reduction in FcγRIIIa binding for Remsima. While this difference was acknowledged in Remsima regulatory filings, our glycoform analysis and receptor binding results appear to be somewhat different from the published values, likely due to methodological differences between laboratories and improved glycoform identification by our laboratory using a peptide map-based method. Our mass spectrometry based analysis provides rapid and robust analytical information vital for biosimilar development. We have demonstrated the utility of our multiple attribute monitoring workflow using the model mAbs Remicade and Remsima, and have provided a template for analysis of future mAb biosimilars

    Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

    Get PDF
    Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity

    Elliptic flow from two- and four-particle correlations in Au + Au collisions at sqrt{s_{NN}} = 130 GeV

    Get PDF
    Elliptic flow holds much promise for studying the early-time thermalization attained in ultrarelativistic nuclear collisions. Flow measurements also provide a means of distinguishing between hydrodynamic models and calculations which approach the low density (dilute gas) limit. Among the effects that can complicate the interpretation of elliptic flow measurements are azimuthal correlations that are unrelated to the reaction plane (non-flow correlations). Using data for Au + Au collisions at sqrt{s_{NN}} = 130 GeV from the STAR TPC, it is found that four-particle correlation analyses can reliably separate flow and non-flow correlation signals. The latter account for on average about 15% of the observed second-harmonic azimuthal correlation, with the largest relative contribution for the most peripheral and the most central collisions. The results are also corrected for the effect of flow variations within centrality bins. This effect is negligible for all but the most central bin, where the correction to the elliptic flow is about a factor of two. A simple new method for two-particle flow analysis based on scalar products is described. An analysis based on the distribution of the magnitude of the flow vector is also described.Comment: minor text change

    Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on its redshift

    Get PDF
    We report the first detection of very-high-energy (VHE) gamma-ray emission above 140 GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 +- 0.5_stat +- 0.3_syst and a flux normalization at 200 GeV of (5.1 +- 0.9_stat +- 0.5_syst) x 10^{-11} TeV^-1 cm^-2 s^-1, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.Comment: accepted for publication, Ap
    corecore