5,630 research outputs found

    Upper limits on the total cosmic-ray luminosity of individual sources

    Get PDF
    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) (E > 10^18 eV) are determined for five individual sources. The upper limit on the integral flux of GeV-TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV-TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV-TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.Fil: Anjos, R. C.. Universidade de Sao Paulo; BrasilFil: de Souza, V.. Universidade de Sao Paulo; BrasilFil: Supanitsky, Alberto Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

    Making Sense Of Blood-based Proteomics And Metabolomics In Psychiatric Research.

    Get PDF
    This manuscript describes the basics of proteomic and metabolic profiling of blood serum and plasma from patients with psychiatric disorders. It will also explain the rationale behind the use of these body fluids due to need for user friendly and rapid tests in the clinic with simple sampling procedures. It has emerged over the last 15 years or so that psychiatric disorders are whole body diseases and the bloodstream is a means of molecular transport and therefore provides a conduit for two way communication with the brain. Here we also describe some of the basic biomarker findings from studies of serum or plasma from patients with psychiatric disorders like schizophrenia, major depression and bipolar disorder. Finally, we will discuss potential future advancements in this area which includes the development of held devices containing miniature proteomic and metabolic assays which can be used for facilitating diagnosis in a point-of-care setting and yield results in less than 15 minutes from a single drop of blood

    KINEMATIC ANALYSIS OF VOLLEYBALL SPIKE

    Get PDF
    Volleyball nowadays is, after soccer, the most practiced sport in Brazil (Bojikian, 2004). However, studies related to the patterns used by the athletes during training are not in common use, especially those aiming to help the coach detect failures. Our goal was to compare the kinematic pattern of the volleyball spike performed by three female athletes of the Sport Club Pinheiros who played as outside hitters. The analysed variables were: ankle, knee and elbow angles during the last step and jump, and the maximum height attained during the jump

    Controls on the erosion of the continental margin of southeast Brazil from cosmogenic 10Be in river sediments

    Get PDF
    The Atlantic Ocean coast region of southeast Brazil contains two coast-parallel mountain ranges (the Serra do Mar and Serra da Mantiqueira) generated by tectonic activity pulses tens of millions years after the main continental rift event occurred around 120 Ma. Although the short-term erosion rates for the region are established, the relative importance of the factors controlling erosion is poorly constrained. We combine new and published catchment-averaged erosion rates (n = 48) using in situ-produced 10Be concentrations in quartz from river sediments to establish the regional erosion pattern. The river catchments are (i) escarpment topography, (ii) high-altitude low-relief and (iii) mixed topography, which record how escarpment fronts are migrating inland. Ocean-facing coastal escarpment catchments of the Serra do Mar (ε = 18–53 m/Ma) can be eroded approximately twice as fast as continent-facing escarpment catchments in the Serra do Mar and Serra da Mantiqueira (ε = 7–24 m/Ma). The correlation between the normalized channel steepness index (ksn) and slope angle indicates that river incision and hillslope erosion processes combine to maintain the high relief. The Serra do Mar catchments define a mean slope angle threshold indicating that landslides are the dominant erosional process when slope angles in excess of ~30°. Tectonic activity is low and plays no significant role in driving erosion. A first-order relationship between erosion rate and precipitation-temperature across the region implies that climate plays a key role in soil production, river incision and in triggering erosional processes. Although the high topographic relief is a pre-condition for the occurrence of significant erosion, the climatic condition is the outlining factor of the regional variation in erosion rates

    Diffusive epidemic process: theory and simulation

    Full text link
    We study the continuous absorbing-state phase transition in the one-dimensional diffusive epidemic process via mean-field theory and Monte Carlo simulation. In this model, particles of two species (A and B) hop on a lattice and undergo reactions B -> A and A + B -> 2B; the total particle number is conserved. We formulate the model as a continuous-time Markov process described by a master equation. A phase transition between the (absorbing) B-free state and an active state is observed as the parameters (reaction and diffusion rates, and total particle density) are varied. Mean-field theory reveals a surprising, nonmonotonic dependence of the critical recovery rate on the diffusion rate of B particles. A computational realization of the process that is faithful to the transition rates defining the model is devised, allowing for direct comparison with theory. Using the quasi-stationary simulation method we determine the order parameter and the survival time in systems of up to 4000 sites. Due to strong finite-size effects, the results converge only for large system sizes. We find no evidence for a discontinuous transition. Our results are consistent with the existence of three distinct universality classes, depending on whether A particles diffusive more rapidly, less rapidly, or at the same rate as B particles.Comment: 19 pages, 5 figure
    corecore