8 resultados para Rebel slaves

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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We report an improved measurement of (nu) over bar (mu) disappearance over a distance of 735 km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a (nu) over bar (mu)-enhanced configuration. From a total exposure of 2.95 x 10(20) protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of Delta(m) over bar (2) = [2.62(-0.28)(+0.31)(stat) +/- 0.09(syst)] x 10(-3) eV(2) and constrain the (nu) over bar (mu) mixing angle sin(2)(2 (theta) over bar) > 0.75 (90% C.L.). These values are in agreement with Delta m(2) and sin(2)(2 theta) measured for nu(mu), removing the tension reported in [P. Adamson et al. (MINOS), Phys. Rev. Lett. 107, 021801 (2011).].

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The KASCADE-Grande experiment, located at Karlsruhe Institute of Technology (Germany) is a multi-component extensive air-shower experiment devoted to the study of cosmic rays and their interactions at primary energies 10(14)-10(18) eV. Main goals of the experiment are the measurement of the all-particle energy spectrum and mass composition in the 10(16)-10(18) eV range by sampling charged (N-ch) and muon (N-mu) components of the air shower. The method to derive the energy spectrum and its uncertainties, as well as the implications of the obtained result, is discussed. An overview of the analyses performed by KASCADE-Grande to derive the mass composition of the measured high-energy comic rays is presented as well. (C) 2012 Elsevier By. All rights reserved.

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We observe a correlation between the slope of radio lateral distributions and the mean muon pseudorapidity of 59 individual cosmic-ray-air-shower events. The radio lateral distributions are measured with LOPES, a digital radio interferometer colocated with the multidetector-air-shower array KASCADE-Grande, which includes a muon-tracking detector. The result proves experimentally that radio measurements are sensitive to the longitudinal development of cosmic-ray air showers. This is one of the main prerequisites for using radio arrays for ultra-high-energy particle physics and astrophysics.

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The energy spectrum of cosmic rays between 10(16) eV and 10(18) eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is described. The resulting all-particle energy spectrum exhibits strong hints for a hardening of the spectrum at approximately 2 . 10(16) eV and a significant steepening at approximate to 8 . 10(16) eV. These observations challenge the view that the spectrum is a single power law between knee and ankle. Possible scenarios generating such features are discussed in terms of astrophysical processes that may explain the transition region from galactic to extragalactic origin of cosmic rays. (C) 2012 Elsevier B.V. All rights reserved.

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The Brazilian population represents an admixture of native Amerindians, Portuguese settlers and Africans who were brought as slaves during the colonization period that began in the 16th century and was followed by waves of immigrations of Europeans and Asians in the 20th century. The contribution of these different ethnic groups to the constitution of Brazilian populations from different geographic regions is variable and, in addition to environmental factors, might act by determining different allele profiles among Brazilian populations from different regions. We studied polymorphic sites at the 3' untranslated region of the HLA-G gene in individuals from a Northeastern Brazilian region and compared them to our previously published data about a Southeastern Brazilian region, located at a distance of 2589 km. Our results showed that most polymorphic sites present a similar distribution in both populations, except for the lower frequency of the +3003C allele in the Northeastern population compared to the Southeastern population. Although differences in genotypic distribution were only significant for the +3003 locus (P = 0.0201), the diversity of haplotypes was distinct for each population. These results are important for casecontrol studies on the association of human leucocyte antigen-G polymorphism with disease and also in terms of the genetic structure of two distinct Brazilian populations.

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We have searched for sidereal variations in the rate of antineutrino interactions in the MINOS Near Detector. Using antineutrinos produced by the NuMI beam, we find no statistically significant sidereal modulation in the rate. When this result is placed in the context of the Standard Model Extension theory we are able to place upper limits on the coefficients defining the theory. These limits are used in combination with the results from an earlier analysis of MINOS neutrino data to further constrain the coefficients.

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This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9 kton-years) of data. A total of 2072 candidate events are observed. These are separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons, both produced by charged-current nu(mu) and (nu) over bar (mu) interactions, and 701 contained-vertex showers, composed mainly of charged-current nu(e) and (nu) over bar (e) interactions and neutral-current interactions. The curvature of muon tracks in the magnetic field of the MINOS Far Detector is used to select separate samples of nu(mu) and (nu) over bar (mu) events. The observed ratio of (nu) over bar (mu) to v(mu) events is compared with the Monte Carlo ( MC) simulation, giving a double ratio of R((nu) over bar/nu)data/R(nu) over bar/nu MC = 1.03 +/- 0.08(stat) +/- 0.08(syst). The v(mu) and (nu) over bar (mu) data are separated into bins of L/E resolution, based on the reconstructed energy and direction of each event, and a maximum likelihood fit to the observed L/E distributions is used to determine the atmospheric neutrino oscillation parameters. This fit returns 90% confidence limits of |Delta m(2)| = (1.9 +/- 0.4) x 10(-3) eV(2) and sin(2)2 theta > 0.86. The fit is extended to incorporate separate nu(mu) and (nu) over bar mu oscillation parameters, returning 90% confidence limits of |Delta m(2)| - |Delta(m) over bar (2)| = 0.6(-0.8)(+2.4) x 10(-3) eV(2) on the difference between the squared-mass splittings for neutrinos and antineutrinos.

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Trata-se de proceder a uma leitura histórica dos problemas da perseguição religiosa, conversão e do memoricídio operado pelos processos de aculturação dos escravos na formação do Brasil, em face das garantias atuais do “Estatuto da Igualdade Racial”.