Avaliação do stress parental em mães de crianças com perturbação de hiperatividade com défice de atenção

Introdução: Pretendeu-se identificar os níveis de stress nas mães de crianças e adolescentes com perturbação de hiperatividadecom défice de atenção e verificar se existe uma associação entre o stress percecionado por estas mães e o funcionamento familiar.Métodos: Foram utilizados o índice de stress parental, versão reduzida, que caracteriza o stress parental total de acordo comtrês dimensões (dificuldade parental, interação pais / criança e criança difícil), e a escala de avaliação da adaptabilidade e coesãofamiliar, que classifica as famílias em equilibradas, meio-termo ou extremas.Resultados: Participaram neste estudo 89 mães. Obtiveram-se valores médios no questionário índice de stress parental acimado percentil 85 (valor de cutoff) nas subescalas interação disfuncional criança-pais, criança difícil e no valor de stress total.Verificou-se ainda que havia uma forte correlação entre stress total e as três subescalas, isto é, mães com níveis mais elevadosde stress tendem a ter uma maior perceção de dificuldade parental, de interação disfuncional com a criança e de criança difícil.Não se verificaram diferenças estatisticamente significativas entre o tipo de família (equilibrada versus meio-termo ou extrema,ou monoparental versus nuclear) e o stress parental.Discussão: Concluiu-se que as mães das crianças com perturbação de hiperatividade com défice de atenção apresentam elevadosníveis de stress, o qual parece advir fundamentalmente das características da criança, que é percecionada como sendouma criança difícil, e de uma interação disfuncional entre os pais e a criança. Não parece haver relação entre o nível de stressexperienciado por estas mães e a funcionalidade ou organização da famíli

Level of physical activity, stress and health of bank clerks

The purpose of this study was to investigate the relationship among level of physical activity, stress and health in male and female bank clerks. Two hundred eighty three bank clerks answered the Questionnaire of Habitual Physical Activities (Pate et al., 1995), the Perceived Stress Scale (Cohen, Karmack, & Mermelsteinm, 1983), and two scales of self-evaluated health (Andrade, 2001). More active bank clerks showed themselves as less stressed (F = 4.87, p = .008), significant results only for women (F = 4.11, p = .019). More active bank clerks also perceived themselves as healthier (p = .000, gamma = .56) and fell ill less frequently (p = .02, gamma = −.34), significant results only for men (p = .001, gamma = .60 e p = .033, gamma = −.33, respectively). Bank clerks with better perceived health showed significantly lower stress (F = 13.45, p = .000), significant results for both men (F = 9.75, p = .000) and women (F = 7.88, p = .000), as well as those getting sick less frequently (F = 5.40, p = .001), significant results only for women (F = 4.60, p = .004). Findings indicated a relationship among all the variables investigated and differing relationships for men and women

Clusters of Galaxies: New Results from the CLEF Hydrodynamics Simulation

Preliminary results are presented from the CLEF hydrodynamics simulation, a large (N=2(428)^3 particles within a 200 Mpc/h comoving box) simulation of the LCDM cosmology that includes both radiative cooling and a simple model for galactic feedback. Specifically, we focus on the X-ray properties of the simulated clusters at z=0 and demonstrate a reasonable level of agreement between simulated and observed cluster scaling relations.Comment: 7 pages, 4 figures, accepted for publication in Advances in Space Research (proceedings of the COSPAR 2004 Assembly, Paris

Limits on the gravity wave contribution to microwave anisotropies

We present limits on the fraction of large angle microwave anisotropies which could come from tensor perturbations. We use the COBE results as well as smaller scale CMB observations, measurements of galaxy correlations, abundances of galaxy clusters, and Lyman alpha absorption cloud statistics. Our aim is to provide conservative limits on the tensor-to-scalar ratio for standard inflationary models. For power-law inflation, for example, we find T/S<0.52 at 95% confidence, with a similar constraint for phi^p potentials. However, for models with tensor amplitude unrelated to the scalar spectral index it is still currently possible to have T/S>1.Comment: 23 pages, 7 figures, accepted for publication in Phys. Rev. D. Calculations extended to blue spectral index, Fig. 6 added, discussion of results expande

The Formation of Cosmic Structures in a Light Gravitino Dominated Universe

We analyse the formation of cosmic structures in models where the dark matter is dominated by light gravitinos with mass of $100$ eV -- 1 keV, as predicted by gauge-mediated supersymmetry (SUSY) breaking models. After evaluating the number of degrees of freedom at the gravitinos decoupling ($g_*$), we compute the transfer function for matter fluctuations and show that gravitinos behave like warm dark matter (WDM) with free-streaming scale comparable to the galaxy mass scale. We consider different low-density variants of the WDM model, both with and without cosmological constant, and compare the predictions on the abundances of neutral hydrogen within high-redshift damped Ly--$\alpha$ systems and on the number density of local galaxy clusters with the corresponding observational constraints. We find that none of the models satisfies both constraints at the same time, unless a rather small $\Omega_0$ value (\mincir 0.4) and a rather large Hubble parameter (\magcir 0.9) is assumed. Furthermore, in a model with warm + hot dark matter, with hot component provided by massive neutrinos, the strong suppression of fluctuation on scales of \sim 1\hm precludes the formation of high-redshift objects, when the low--$z$ cluster abundance is required. We conclude that all different variants of a light gravitino DM dominated model show strong difficulties for what concerns cosmic structure formation. This gives a severe cosmological constraint on the gauge-mediated SUSY breaking scheme.Comment: 28 pages,Latex, submitted for publication to Phys.Rev.

Planck-scale quintessence and the physics of structure formation

In a recent paper we considered the possibility of a scalar field providing an explanation for the cosmic acceleration. Our model had the interesting properties of attractor-like behavior and having its parameters of O(1) in Planck units. Here we discuss the effect of the field on large scale structure and CMB anisotropies. We show how some versions of our model inspired by "brane" physics have novel features due to the fact that the scalar field has a significant role over a wider range of redshifts than for typical "dark energy" models. One of these features is the additional suppression of the formation of large scale structure, as compared with cosmological constant models. In light of the new pressures being placed on cosmological parameters (in particular H_0) by CMB data, this added suppression allows our "brane" models to give excellent fits to both CMB and large scale structure data.Comment: 18 pages, 12 figures, submitted to PR

Cosmological parameters from SDSS and WMAP

We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.htm

Colossal dielectric constants in transition-metal oxides

Many transition-metal oxides show very large ("colossal") magnitudes of the dielectric constant and thus have immense potential for applications in modern microelectronics and for the development of new capacitance-based energy-storage devices. In the present work, we thoroughly discuss the mechanisms that can lead to colossal values of the dielectric constant, especially emphasising effects generated by external and internal interfaces, including electronic phase separation. In addition, we provide a detailed overview and discussion of the dielectric properties of CaCu3Ti4O12 and related systems, which is today's most investigated material with colossal dielectric constant. Also a variety of further transition-metal oxides with large dielectric constants are treated in detail, among them the system La2-xSrxNiO4 where electronic phase separation may play a role in the generation of a colossal dielectric constant.Comment: 31 pages, 18 figures, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom