Atmospheric NLTE-Models for the Spectroscopic Analysis of Blue Stars with Winds. III. X-ray emission from wind-embedded shocks

X-rays/EUV radiation emitted from wind-embedded shocks in hot, massive stars can affect the ionization balance in their outer atmospheres, and can be the mechanism responsible for the production of highly ionized species. To allow for these processes in the context of spectral analysis, we have implemented such emission into our unified, NLTE model atmosphere/spectrum synthesis code FASTWIND. The shock structure and corresponding emission is calculated as a function of user-supplied parameters. We account for a temperature and density stratification inside the post-shock cooling zones, calculated for radiative and adiabatic cooling in the inner and outer wind, respectively. The high-energy absorption of the cool wind is considered by adding important K-shell opacities, and corresponding Auger ionization rates have been included into the NLTE network. We tested and verified our implementation carefully against corresponding results from various alternative model atmosphere codes, and studied the effects from shock emission for important ions from He, C, N, O, Si, and P. Surprisingly, dielectronic recombination turned out to play an essential role for the ionization balance of OIV/OV around Teff = 45,000 K. Finally, we investigated the behavior of the mass absorption coefficient, kappa_nu(r), important in the context of X-ray line formation in massive star winds. In almost all considered cases, direct ionization is of major influence, and Auger ionization significantly affects only NVI and OVI. The approximation of a radially constant kappa_nu is justified for r > 1.2 Rstar and lambda < 18 A, and also for many models at longer wavelengths. To estimate the actual value of this quantity, however, the HeII opacities need to be calculated from detailed NLTE modeling, at least for wavelengths longer than 18 to 20 A, and information on the individual CNO abundances has to be present.Comment: accepted by A&

Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies angular correlation function

We analyse the large-scale angular correlation function (ACF) of the CMASS luminous galaxies (LGs), a photometric-redshift catalogue based on the Data Release 8 (DR8) of the Sloan Digital Sky Survey-III. This catalogue contains over $600 \, \, 000$ LGs in the range $0.45 \leq z \leq 0.65$, which was split into four redshift shells of constant width. First, we estimate the constraints on the redshift-space distortion (RSD) parameters $b\sigma_8$ and $f\sigma_8$, where $b$ is the galaxy bias, $f$ the growth rate and $\sigma_8$ is the normalization of the perturbations, finding that they vary appreciably among different redshift shells, in agreement with previous results using DR7 data. When assuming constant RSD parameters over the survey redshift range, we obtain $f\sigma_8 = 0.69 \pm 0.21$, which agrees at the $1.5\sigma$ level with Baryon Oscillation Spectroscopic Survey DR9 spectroscopic results. Next, we performed two cosmological analyses, where relevant parameters not fitted were kept fixed at their fiducial values. In the first analysis, we extracted the baryon acoustic oscillation peak position for the four redshift shells, and combined with the sound horizon scale from 7-year \textit{Wilkinson Microwave Anisotropy Probe} $(WMAP7)$ to produce the constraints $\Omega_{m}=0.249 \pm 0.031$ and $w=-0.885 \pm 0.145$. In the second analysis, we used the ACF full shape information to constrain cosmology using real data for the first time, finding $\Omega_{m} = 0.280 \pm 0.022$ and $f_b = \Omega_b/\Omega_m = 0.211 \pm 0.026$. These results are in good agreement with $WMAP7$ findings, showing that the ACF can be efficiently applied to constrain cosmology in future photometric galaxy surveys.Comment: MNRAS accepted. Minor corrections to match publish versio

Renormalizability of Nonrenormalizable Field Theories

We give a simple and elegant proof of the Equivalence Theorem, stating that two field theories related by nonlinear field transformations have the same S matrix. We are thus able to identify a subclass of nonrenormalizable field theories which are actually physically equivalent to renormalizable ones. Our strategy is to show by means of the BRS formalism that the "nonrenormalizable" part of such fake nonrenormalizable theories, is a kind of gauge fixing, being confined in the cohomologically trivial sector of the theory.Comment: 3 pages, revtex, no figure

Validade e confiabilidade do diâmetro abdominal sagital enquanto preditor de gordura abdominal visceral

OBJECTIVES: To evaluate the reliability of the sagittal abdominal diameter and its validity as a predictor of visceral abdominal fat, as well as to identify the most appropriate cut-off points to identify the area of visceral fat that is known to represent a risk factor for cardiovascular disease. DESIGN: Validation study. SUBJECTS: 92 healthy volunteers (57 women, 35 men), age: 20-83 y, body mass index: 19.3 to 35.9 kg/m². MEASUREMENTS: Sagittal abdominal diameter (SAD), weight, height, circumferences (waist, hip, and thigh), sub-scapular skinfold thickness, abdominal diameter index, and waist-hip ratio (WHR). METHOD OF CHOICE: Computed tomography (CT). STATISTIC: Receiver operating characteristic (ROC) curve. RESULTS: The reliability for SAD measurement was very high (Inter-class coefficient = 0.99). Visceral fat as measured by VAF through CT was highly correlated with SAD (women r = 0.80; men r = 0.64, p < 0.001), waist circumference (women r = 0.77; men r = 0.73, p < 0.001), and WHR (women r = 0.72; men r = 0.58, p < 0.001). The ROC curve indicated 19.3 cm and 20.5 cm as the threshold values for abdominal sagittal diameter in women and men (sensitivity 85% and 83%, specificity 77% and 82%, respectively). CONCLUSIONS: There was a high correlation between SAD and VAF. The cut-off values identified for SAD presented a sensitivity and specificity that were considered adequate.OBJETIVOS: Avaliar a confiabilidade do diâmetro abdominal sagital e a sua validade enquanto preditor de gordura abdominal visceral, assim como identificar os pontos de corte mais apropriados para identificar a área de gordura visceral que é conhecida por representar fator de risco para doença cardiovascular. MÉTODOS: Desenho: Estudo de validação. Amostra: 92 voluntários saudáveis (57 mulheres, 35 homens), idade: 20-83 anos, índice de massa corporal: 19,3 a 35,9 kg/m². Medidas: Diâmetro abdominal sagital (DAS), peso, altura, circunferências (cintura, quadril e coxa), pregas cutâneas tricipital e subescapular, índice diâmetro abdominal e razão cintura-quadril (RCQ). MÉTODO DE ESCOLHA: Tomografia computadorizada (TC). ESTATÍSTICA: Curva ROC (receiver operating characteristic). RESULTADOS: A confiabilidade do DAS foi muito alta (coeficiente inter-classe = 0,99). A área de gordura visceral medida pela TC teve uma alta correlação com o DAS (mulheres r = 0,80, homens r = 0,64, p < 0,001), circunferência da cintura (mulheres r = 0,77, homens r = 0,73, p < 0,001) e com a RCQ (mulheres r = 0,72, homens r = 0,58, p < 0,001). A curva ROC indicou 19,3 cm e 20,5 cm como valores limites para o diâmetro abdominal sagital em mulheres e homens (sensibilidade de 85% e 83%, especificidade de 77% e 82%, respectivamente). CONCLUSÕES: Observou-se alta correlação entre o DAS e a área de gordura abdominal visceral. Os pontos de corte identificados para o DAS apresentaram sensibilidade e especificidade adequadas.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal da Bahia Escola de Nutrição Departamento Ciência da NutriçãoUniversidade Federal de São Paulo (UNIFESP) Department of Health and Human Services of Centers for Disease Control and PreventionUniversidade Federal de São Paulo (UNIFESP) Departamento de Medicina PreventivaUNIFESP, Department of Health and Human Services of Centers for Disease Control and PreventionUNIFESP, Depto. de Medicina PreventivaSciEL

Using Meta-Ethnography to Synthesize Research: A Worked Example of the Relations between Personality on Software Team Processes

Context: The increase in the number of qualitative and mixed-methods research published in software engineering has created an opportunity for further knowledge generation through the synthesis of studies with similar aims. This is particularly true in the research on human aspects because the phenomena of interest are often better understood using qualitative research. However, the use of qualitative synthesis methods is not widespread and worked examples of their consistent application in software engineering are needed. Objective: To explore the use of meta-ethnography in the synthesis of empirical studies in software engineering through an example using studies about the relations between personality and software team processes. Methods: We applied the seven phases of meta-ethnography on a set of articles selected from a previously developed systematic review, to assess the appropriateness of meta-ethnography in this domain with respect to ease of use, and usefulness and reliability of results. Results: Common concepts were identified through reading and interpreting the studies. Then, second order translations were built and used to synthesize a model of the relationships between personality and software team processes. Conclusions: Meta-ethnography is adequate in the synthesis of empirical studies even in the context of mixed-methods studies. However, we believe that the method should not be used to synthesize studies that are too disparate to avoid the development of gross generalizations, which tend to be fruitless and are contrary to the central tenets of interpretive research