1,203 research outputs found

    A study of the ethical dilemmas experienced by school psychologists in Portugal

    Get PDF
    Published online: 06 Apr 2015This study examines the ethical dilemmas and difficulties encountered by Portuguese school psychologists. As part of a larger survey, participants were asked about ethical issues faced in daily practice and asked to describe ethical incidents. Of the 477 respondents, 274 reported 441 ethically troubling or challenging situations. Responses were coded into a six-category system based on the code of ethics of Portuguese psychologists. Most of the reported dilemmas concerned privacy and confidentiality principles (53%). Results are discussed in light of relevant literature and international findings. Implications for the development of the profession and future research are provided.This research was financially sponsored by the Portuguese Foundation for Science and Technology (Doctoral grant, SFRH/BD/78646/2011)

    The Unmet Needs for Studying Chronic Pelvic/Visceral Pain Using Animal Models

    Get PDF
    The different definitions of chronic pelvic/visceral pain used by international societies have changed over the years. These differences have a great impact on the way researchers study chronic pelvic/visceral pain. Recently, the role of systemic changes, including the role of the central nervous system, in the perpetuation and chronification of pelvic/visceral pain has gained weight. Consequently, researchers are using animal models that resemble those systemic changes rather than using models that are organ- or tissue-specific. In this review, we discuss the advantages and disadvantages of using bladder-centric and systemic models, enumerating some of the central nervous system changes and pain-related behaviors occurring in each model. We also present some drawbacks when using animal models and pain-related behavior tests and raise questions about possible, yet to be demonstrated, investigator-related bias. We also suggest new approaches to study chronic pelvic/visceral pain by refining existing animal models or using new ones.</jats:p

    Núcleos de seleção e estratégias para a introdução e produção de touros nelore no Pantanal.

    Get PDF
    Este trabalho teve o objetivo de avaliar algumas questões relacionadas a produção e reposição de touros no Pantanal, como suporte para a tomada de decisões tendo em vista a melhoria dos índices de produtividade dos rebanhos.bitstream/item/37394/1/BP69.pd

    Bounds on the electromagnetic interactions of excited spin-3/2 leptons

    Get PDF
    We discuss possible deviations from QED produced by a virtual excited spin-3/2 lepton in the reaction e+e2γe^+e^- \longrightarrow 2\gamma. Data recorded by the OPAL Collaboration at a c.m. energy s=183GeV\sqrt{s} = 183 GeV are used to establish bounds on the nonstandard-lepton mass and coupling strengths.Comment: Latex, 5 pages, 7 ps figures. To be published in Phys. Rev.

    Constraining models for the origin of ultra-high-energy cosmic rays with a novel combined analysis of arrival directions, spectrum, and composition data measured at the Pierre Auger Observatory

    Get PDF
    The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical models with homogeneous source distributions. Studies of the distribution of the cosmic-ray arrival directions show a better agreement with models in which a fraction of the flux is non-isotropic and associated with the nearby radio galaxy Centaurus A or with catalogs such as that of starburst galaxies. Here, we present a novel combination of both analyses by a simultaneous fit of arrival directions, energy spectrum, and composition data measured at the Pierre Auger Observatory. The model takes into account a rigidity-dependent magnetic field blurring and an energy-dependent evolution of the catalog contribution shaped by interactions during propagation. We find that a model containing a flux contribution from the starburst galaxy catalog of around 20% at 40 EeV with a magnetic field blurring of around 20◦ for a rigidity of 10 EV provides a fair simultaneous description of all three observables. The starburst galaxy model is favored with a significance of 4.5σ (considering experimental systematic effects) compared to a reference model with only homogeneously distributed background sources. By investigating a scenario with Centaurus A as a single source in combination with the homogeneous background, we confirm that this region of the sky provides the dominant contribution to the observed anisotropy signal. Models containing a catalog of jetted active galactic nuclei whose flux scales with the γ-ray emission are, however, disfavored as they cannot adequately describe the measured arrival directions

    AugerPrime surface detector electronics

    Get PDF
    Operating since 2004, the Pierre Auger Observatory has led to major advances in our understanding of the ultra-high-energy cosmic rays. The latest findings have revealed new insights that led to the upgrade of the Observatory, with the primary goal of obtaining information on the primary mass of the most energetic cosmic rays on a shower-by-shower basis. In the framework of the upgrade, called AugerPrime, the 1660 water-Cherenkov detectors of the surface array are equipped with plastic scintillators and radio antennas, allowing us to enhance the composition sensitivity. To accommodate new detectors and to increase experimental capabilities, the electronics is also upgraded. This includes better timing with up-to-date GPS receivers, higher sampling frequency, increased dynamic range, and more powerful local processing of the data. In this paper, the design characteristics of the new electronics and the enhanced dynamic range will be described. The manufacturing and test processes will be outlined and the test results will be discussed. The calibration of the SD detector and various performance parameters obtained from the analysis of the first commissioning data will also be presented

    Testing effects of Lorentz invariance violation in the propagation of astroparticles with the Pierre Auger Observatory

    Get PDF
    Lorentz invariance violation (LIV) is often described by dispersion relations of the form E i2 = m i2+p i2+δi,n E 2+n with delta different based on particle type i, with energy E, momentum p and rest mass m. Kinematics and energy thresholds of interactions are modified once the LIV terms become comparable to the squared masses of the particles involved. Thus, the strongest constraints on the LIV coefficients δi,n tend to come from the highest energies. At sufficiently high energies, photons produced by cosmic ray interactions as they propagate through the Universe could be subluminal and unattenuated over cosmological distances. Cosmic ray interactions can also be modified and lead to detectable fingerprints in the energy spectrum and mass composition observed on Earth. The data collected at the Pierre Auger Observatory are therefore possibly sensitive to both the electromagnetic and hadronic sectors of LIV. In this article, we explore these two sectors by comparing the energy spectrum and the composition of cosmic rays and the upper limits on the photon flux from the Pierre Auger Observatory with simulations including LIV. Constraints on LIV parameters depend strongly on the mass composition of cosmic rays at the highest energies. For the electromagnetic sector, while no constraints can be obtained in the absence of protons beyond 1019 eV, we obtain δγ,0 \u3e -10-21, δγ,1 \u3e -10-40 eV-1 and δγ,2 \u3e -10-58 eV-2 in the case of a subdominant proton component up to 1020 eV. For the hadronic sector, we study the best description of the data as a function of LIV coefficients and we derive constraints in the hadronic sector such as δhad,0 \u3c 10-19, δhad,1 \u3c 10-38 eV-1 and δhad,2 \u3c 10-57 eV-2 at 5σ CL

    Constraints on metastable superheavy dark matter coupled to sterile neutrinos with the Pierre Auger Observatory

    Get PDF
    Dark matter particles could be superheavy, provided their lifetime is much longer than the age of the Universe. Using the sensitivity of the Pierre Auger Observatory to ultrahigh energy neutrinos and photons, we constrain a specific extension of the Standard Model of particle physics that meets the lifetime requirement for a superheavy particle by coupling it to a sector of ultralight sterile neutrinos. Our results show that, for a typical dark coupling constant of 0.1, the mixing angle θm between active and sterile neutrinos must satisfy, roughly, θm≲1.5×10-6(MX/109 GeV)-2 for a mass MX of the dark-matter particle between 108 GeV and 1011 GeV
    corecore