1,645 research outputs found

    Quantum cosmology of scalar-tensor theories and self-adjointness

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    In this paper, the problem of the self-adjointness for the case of a quantum minisuperspace Hamiltonian retrieved from a Brans-Dicke (BD) action is investigated. Our matter content is presented in terms of a perfect fluid, onto which the Schutz's formalism will be applied. We use the von Neumann theorem and the similarity with the Laplacian operator in one of the variables to determine the cases where the Hamiltonian is self-adjoint and if it admits self-adjoint extensions. For the latter, we study which extension is physically more suitable.Comment: Latex file, 12 pages. Small changes made in the paper, and a a new appendix adde

    Meaning of the Pap smear for health student

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    OBJECTIVE: To describe the meanings of the Pap smear for health students. METHODS: Descriptive study, qualitative approach, with 45 students from the health area of ​​a Higher Education Institution, in the Northeast of Brazil. Data were collected in 2017, by means of interviews, processed in the IRaMuTeQ software, and pushed by the Descending Hierarchical Classification. RESULTS: The students recognize that the education in health is the best strategy to prevent cervical cancer, as it is an essential tool in primary care and must be performed by health professionals. CONCLUSION: The meanings found by the students revealed a concern with their role in the Pap smear and, therefore, considers it very important to improve their knowledge in this area so that they can provide quality care to women seeking to prevent cervical cancer.OBJETIVO: Descrever os significados do exame de Papanicolaou para estudantes da saúde. MÉTODOS: Estudo descritivo, de abordagem qualitativa, com 45 estudantes da área de saúde de uma Instituição de Ensino Superior, no Nordeste do Brasil. Os dados foram coletados em 2017, por meio de entrevistas, processados no software IRaMuTeQ, e analisados pela Classificação Hierárquica Descendente. RESULTADOS: Os estudantes reconhecem que a educação em saúde é a melhor estratégia para prevenir o cancro do colo do útero, por ser uma ferramenta essencial na atenção básica e deve ser realizada por profissionais de saúde. CONCLUSÃO: Os significados atribuídos pelos estudantes revelaram uma preocupação com seu papel no exame de Papanicolaou e, portanto, consideram muito importante aprimorar seus conhecimentos nessa área para que possam prestar um atendimento de qualidade às mulheres que buscam a prevenção do cancro de colo do úteroinfo:eu-repo/semantics/publishedVersio

    Non-equilibrium dynamics of a thermal plasma in a gravitational field

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    We introduce functional methods to study the non-equilibrium dynamics of a quantum massless scalar field at finite temperature in a gravitational field. We calculate the Close Time Path (CTP) effective action and, using its formal equivalence with the influence functional, derive the noise and dissipation kernels of the quantum open system in terms of quantities in thermodynamical equilibrium. Using this fact, we formally prove the existence of a Fluctuation-Dissipation Relation (FDR) at all temperatures between the quantum fluctuations of the plasma in thermal equilibrium and the energy dissipated by the external gravitational field. What is new is the identification of a stochastic source (noise) term arising from the quantum and thermal fluctuations in the plasma field, and the derivation of a Langevin-type equation which describes the non-equilibrium dynamics of the gravitational field influenced by the plasma. The back reaction of the plasma on the gravitational field is embodied in the FDR. From the CTP effective action the contribution of the quantum scalar field to the thermal graviton polarization tensor can also be derived and it is shown to agree with other techniques, most notably, Linear Response Theory (LRT). We show the connection between the LRT, which is applicable for near-equilibrium conditions and the functional methods used in this work which are useful for fully non-equilibrium conditions.Comment: Final version published in Phys. Rev.

    Signatures of Primordial non-Gaussianities in the Matter Power-Spectrum and Bispectrum: the Time-RG Approach

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    We apply the time-renormalization group approach to study the effect of primordial non-Gaussianities in the non-linear evolution of cosmological dark matter density perturbations. This method improves the standard perturbation approach by solving renormalization group-like equations governing the dynamics of gravitational instability. The primordial bispectra constructed from the dark matter density contrast and the velocity fields represent initial conditions for the renormalization group flow. We consider local, equilateral and folded shapes for the initial non-Gaussianity and analyze as well the case in which the non-linear parameter f_{NL} parametrizing the strength of the non-Gaussianity depends on the momenta in Fourier space through a power-law relation, the so-called running non-Gaussianity. For the local model of non-Gaussianity we compare our findings for the power-spectrum with those of recent N-body simulations and find that they accurately fit the N-body data up to wave-numbers k \sim 0.25 h/Mpc at z=0. We also present predictions for the (reduced) matter bispectra for the various shapes of non-Gaussianity.Comment: 27 pages, 12 figures. Results and discussion for a particular case added. One figure and one reference added. Matches with the version accepted for publication in the JCAP

    Nuclear 11.3μm PAH emission in local active galactic nuclei

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    A. Alonso-Herrero et al.We present Gran Telescopio CANARIAS CanariCam 8.7 μm imaging and 7.5-13 μm spectroscopy of six local systems known to host an active galactic nucleus (AGN) and have nuclear star formation. Our main goal is to investigate whether the molecules responsible for the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature are destroyed in the close vicinity of an AGN. We detect 11.3 μm PAH feature emission in the nuclear regions of the galaxies as well as extended PAH emission over a few hundred parsecs. The equivalent width (EW) of the feature shows a minimum at the nucleus but increases with increasing radial distances, reaching typical star-forming values a few hundred parsecs away from the nucleus. The reduced nuclear EWs are interpreted as due to increased dilution from the AGN continuum rather than destruction of the PAH molecules. We conclude that at least those molecules responsible for the 11.3 μm PAH feature survive in the nuclear environments as close as 10 pc from the AGN and for Seyfert-like AGN luminosities. We propose that material in the dusty tori, nuclear gas discs, and/or host galaxies of AGN is likely to provide the column densities necessary to protect the PAH molecules from the AGN radiation field. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.AA-H and AH-C are partly funded by the Universidad de Cantabria through the Augusto G. Linares programme. AA-H and AH-C acknowledge financial support from the Spanish Plan Nacional grant AYA2012-31447, AA-H and PE from grant AYA2009-05705-E, CRA from grant AYA2010-21887-C04.4 (Estallidos), PE from grant AYA2012-31277, and LC from grant AYA2012-32295. CRA acknowledges financial support from the Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-327934) and SFH from the Marie Curie International Incoming Fellowship within the 7th European Community Framework Programme (PIIFGA-2013-623804).Peer Reviewe

    Citotoxicity and immune response induced by organopalladium(II) compounds in mice bearing Ehrlich ascites tumour

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    Cyclometallated palladium(II) complexes are reactive inorganic compounds employed in several biological studies because of their antitumour potential and interaction with immune system. In the present study, the immune and citotoxic response induced by two organopalladated complexes: [{Pd(N,C-dmba)} 2(μ-NCS) 2] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N′-dimethylbenzylamine, dppp = 1,3-bis(diphenylphosphino)propane] and cisplatin (cis-DDP), as standard, were investigated in mice bearing Ehrlich ascites tumour. The mice were divided into five groups and inoculated with the compounds (1) or (2) or cisplatin, or only vehicle or phosphate-buffered saline (PBS). Many parameters were evaluated, such as tumour cell percentage in the peritoneal exsudate, levels of seric nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and increase in life span. Analysis of all data revealed, for compound (2), an activity similar to that presented by cisplatin, resulting in increased life span, lower levels of seric TNF-α and increase in NO production. ©2007 Sociedade Brasileira de Química

    The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

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    The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr
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