Galaxy clusters, type Ia supernovae and the fine structure constant

As is well known, measurements of the Sunyaev-Zeldovich effect can be combined with observations of the X-ray surface brightness of galaxy clusters to estimate the angular diameter distance to these structures. In this paper, we show that this technique depends on the fine structure constant, $\alpha$. Therefore, if $\alpha$ is a time-dependent quantity, e.g., $\alpha=\alpha_0 \phi(z)$, where $\phi$ is a function of redshift, we argue that current data do not provide the real angular diameter distance, $D_{\rm{A}}(z)$, to the cluster but instead $D_A^{data}(z) = \phi(z)^2 D_{\rm{A}}(z)$. We use this result to derive constraints on a possible variation of $\alpha$ for a class of dilaton runaway models considering a sample of 25 measurements of $D_A^{data}(z)$ in redshift range $0.023 < z < 0.784$ and estimates of $D_{\rm{A}}(z)$ from current type Ia supernovae observations. We find no significant indication of variation of $\alpha$ with the present data.Comment: 8 pages, 4 figures, To appear in JCA

Prognostic Factors of Tympanoplasty Type I in Pediatric Population – 4 Years Series of Dona Estefânia Hospital (HDE) of Centro Hospitalar Lisboa CentraL (CHLC –EPE)

Objetivos: Identificação de fatores de prognóstico em crianças submetidas a timpanoplastia tipo I. Materiais e métodos: Estudo retrospetivo baseado na análise de todos os processos clínicos de crianças atá aos 15 anos de idade, submetidas a timpanoplastia tipo I de Portmann durante um período de 4 anos. Resultados: Das 260 timpanoplastias realizadas neste período no serviço foram incluídos no estudo apenas 109 crianças. Das timpanoplastias realizadas, obteve-se sucesso cirúrgico em 68.8%, não se tendo identificado fatores de mau prognóstico cirúrgico com significância estatística. Conclusões: As timpanoplastias tipo I em crianças são um procedimento válido e com elevada taxa de sucesso, não tendo sido identificado qualquer fator de mau prognóstico cirúrgico com significado estatístico.info:eu-repo/semantics/publishedVersio

Gravitational lens time-delay as a probe of a possible time variation of the fine-structure constant

A new method based on large-scale structure observations is proposed to probe a possible time variation of the fine-structure constant ($\alpha$). Our analyses are based on time-delay of Strong Gravitational Lensing and Type Ia Supernovae observations. By considering a class of runaway dilaton models, where the cosmological evolution of the fine-structure constant is given by $\frac{\Delta \alpha}{\alpha} \approx -\gamma \ln{(1+z)}$, we obtain limits on the physical properties parameter of the model ($\gamma$) at the level $10^{-2}$ ($1\sigma$). Although our limits are less restrictive than those obtained by quasar spectroscopy, the approach presented here provides new bounds on the possibility of $\frac{\Delta \alpha}{\alpha} \neq 0$ at a different range of redshifts.Comment: 9 pages, 4 figures and 1 tabl

Retropharyngeal and Lateropharyngeal Infections in Children: The Experience of a Pediatric Hospital During the Last Decade

Introdução: Apresentando-se muitas vezes de forma insidiosa e mascarando-se por tratamentos efectuados previamente, as infecções retro e laterofaríngeas são um desafio diagnóstico. São pouco frequentes na era antibiótica moderna, mas têm capacidade para causarem complicações potencialmente fatais. Material e métodos: Estudo retrospectivo dos casos e análise de dados relativos à epidemiologia, etiologia, apresentação clínica, diagnóstico, tratamento e complicações, de crianças diagnosticadas com infecções retro e laterofaríngeas, no nosso hospital pediátrico, desde Janeiro 2001 a Janeiro 2012. Resultados: Foram incluídas no estudo 23 crianças, com idades compreendidas entre os 3 meses e os 8 anos, com uma média de idades de 47 meses (4 anos). Treze (57%) apresentavam infecções retrofaríngeas, 2 (9%) infecções laterofaríngeas e 8 (35%) ambas. A incidência de casos foi maior no ano de 2010 (4 casos). Doze (52%) eram do sexo masculino e 11 (48%) do sexo feminino. A odinofagia (57%), a cervicalgia (26%) e a recusa alimentar (22%) foram as queixas mais comuns à apresentação. A febre (87%), o torcicolo e a rigidez cervical (65%), a tumefacção cervical (52%) e a prostração (35%) foram os achados físicos mais frequentes. Todos (100%) os doentes receberam antibioticoterapia endovenosa. O tratamento médico sem drenagem foi inicialmente proposto para 15 (65%) crianças. A falência no tratamento médico, requerendo cirurgia, ocorreu em 5 (33%) delas. Num dos casos, foi necessário efectuar uma nova drenagem cirúrgica. O tratamento cirúrgico foi inicialmente proposto para 8 (35%) crianças, tendo sido efectuado durante as primeiras 24 horas. Este tratamento não teve falência em nenhum (0%) dos casos, não tendo sido necessária a realização de uma segunda cirurgia. No entanto, numa das crianças, por aparecimento de um novo abcesso noutra localização, houve necessidade de se proceder à sua drenagem. Duas (9%) crianças tiveram complicações: mediastinite, trombose da veia jugular e síndrome de Claude Bernard Horner. Conclusões: Os sintomas na apresentação das infecções retro e laterofaríngeas na população pediátrica são variados, requerendo o seu diagnóstico um elevado índice de suspeição. O tratamento correcto e atempado é fundamental para um prognóstico favorável. O tratamento ideal nos doentes sem obstrução iminente da via aérea é controverso e objecto de debate, particularmente a escolha entre tratamento médico ou cirúrgico como primeira linha. Torna-se portanto, essencial, maior investigação nesta área, de forma a optimizar resultados

Constraining a possible time-variation of the speed of light along with the fine-structure constant using strong gravitational lensing and Type Ia supernovae observations

The possible time variation of the fundamental constants of nature has been an active subject of research since the large-number hypothesis was proposed by Dirac. In this paper, we propose a new method to investigate a possible time variation of the speed of light (c) along with the fine-structure constant (α) using Strong Gravitational Lensing (SGL) and Type Ia Supernovae (SNe Ia) observations. We assume a general approach to describe the mass distribution of lens-type galaxies, the one in favor of the power-law index model (PLAW). We also consider the runaway dilaton model to describe a possible time-variation of α. In order to explore the results deeply, we split the SGL sample into five sub-samples according to the lens stellar velocity dispersion and three sub-samples according to lens redshift. The results suggest that it is reasonable to treat the systems separately, but no strong indication of varying c was found.Fil: Colaço, L. R.. Universidade Federal do Rio Grande do Norte; BrasilFil: Landau, Susana Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gonzalez, J. E.. Universidade Federal de Sergipe; BrasilFil: Spinelly, J.. Universidade Estadual da Paraiba; BrasilFil: Santos, G .L. F.. Universidade Estadual da Paraiba; Brasi

EXPERIMENTAL STUDY OF TERNARY FUEL BLENDS ON AN ASTM-CFR-CETANE ENGINE

This work analyses how ternary blends of biodiesel, anhydrous and hydrous ethanol, and diesel, in different proportions, behave regarding fuel emissions and combustion parameters. The determination of their cetane number, using an ASTM-CFR cetane research engine is also investigated. The base fuels used were 99,9% pure anhydrous ethanol, commercial diesel, which contains 5% of biodiesel in volume, biodiesel from soybean oil, and hydrous ethanol with 7% of water, in volume. The fuel blends werespecified after a careful bibliography research. Five volume fractions of biodiesel (5, 10, 20, 60 and 100%, in volume) and four of ethanol (0, 5, 8 and 15%, also in volume) were used in this study. All blends have endured a mixture stability test prior to being burned, the ones with clear visual phase separation being eventually rejected. The results for the cetane number presented a clear decrease in its value as ethanol was added. Some blends with high ethanol content failed to provide the minimum cetane number for use in compression ignition engines according to the present Brazilian regulations. Concerning the emissions tests, carbon dioxide emissions showed a decreasing trend as the quantity of added ethanol raised. Carbon monoxide emissions, however, showed the opposite trend. The nitrogen oxides emissions presented an increase as more biodiesel was added to the blend. The conclusions as to the impact of changing ethanol’s volume in the blends were discussed taking in consideration important operational remarks. A final analysis was proposed in order to compare anhydrous and hydrous ethanol. A clear reduction in nitrogen oxides and carbon dioxide emissions was observed, with an almost identical value for the carbon monoxide emissions. Cetane number for the hydrous ethanol blend, however, suffered a decrease compared to the same blend with anhydrous ethanol

A Hubble Constant Estimate from Galaxy Cluster and type Ia SNe Observations

In this work, we constrain the Hubble constant parameter,$H_0$, using a combination of the Pantheon sample and galaxy clusters (GC) measurements from minimal cosmological assumptions. Assuming the validity of the cosmic distance duality relation, an estimator is created for $H_0$ that only depends on simple geometrical distances, which is evaluated from Pantheon and a GC angular diameter distance sample afterward. The statistical and systematic errors in GC measurements are summed in quadrature in our analysis. We find $H_0 = 67.22 \pm 6.07$ ${\rm \,km\, s^{-1}\, Mpc^{-1}}$ in $1\sigma$ confidence level. This measurement presents an error of around 9\%, showing that future and better GC measurements can shed light on the current Hubble tension.Comment: 7 pages, two figure

Static Safety for an Actor Dedicated Process Calculus by Abstract Interpretation

The actor model eases the definition of concurrent programs with non uniform behaviors. Static analysis of such a model was previously done in a data-flow oriented way, with type systems. This approach was based on constraint set resolution and was not able to deal with precise properties for communications of behaviors. We present here a new approach, control-flow oriented, based on the abstract interpretation framework, able to deal with communication of behaviors. Within our new analyses, we are able to verify most of the previous properties we observed as well as new ones, principally based on occurrence counting

Contribution of non-genetic factors to the reproductive performance of mirandesa cows

Characterization of reproductive traits in Mirandesa beef cattle is important for breed improvement and conservation, mainly due to its little genetic diversity. Reduced individual and maternal performance is often associated with inbreeding depression, which could be further aggravate the environmental effects. In this study, 7386 herd records for Mirandesa were used to characterize the main reproductive traits, like age at first calving (AFC), pregnancy length (PL), calving interval (CI), yearly calving distribution (CD) and productive lifespan (PLf). The non-genetic effects were tested using non-parametric methods, as the target variables were not normally distributed. The median for AFC in Mirandesa was close to 32 months; AFC was affected by the production system, farm and by the year and season of birth. The mean for PL was 287±8.9 days, being affected by parity and calf gender. The median CI, of 378 days, was only affected by the breeding program, parity, season and year. Calving season was unevenly distributed over the year, showing different patterns after the production system. The mean productive lifespan of Mirandesa was 6.45 years, though 20% of the cows presented a PLf longer than ten years. The main non-genetic effects suggested that farmer´s decision and nutrition may constrain the expression of the reproductive traits in Mirandesa breed. This aspect needs to be addressed when designing any breeding programs which should prioritise for the increase in the number of calves per year along with a careful selection of reproducers to decrease reported inbreeding.The authors wish to thank ACBRM (Associação de Criadores de Bovinos de Raça Mirandesa) for providing access to the Mirandesa cattle Herdbook.info:eu-repo/semantics/publishedVersio