Morphological Classification of galaxies by Artificial Neural Networks

We explore a method for automatic morphological classification of galaxies by an Artificial Neural Network algorithm. The method is illustrated using 13 galaxy parameters measured by machine (ESO-LV), and classified into five types (E, S0, Sa + Sb, Sc + Sd and Irr). A simple Backpropagation algorithm allows us to train a network on a subset of the catalogue according to human classification, and then to predict, using the measured parameters, the classification for the rest of the catalogue. We show that the neural network behaves in our problem as a Bayesian classifier, i.e. it assigns the a posteriori probability for each of the five classes considered. The network highest probability choice agrees with the catalogue classification for 64 percent of the galaxies. If either the first or the second highest probability choice of the network is considered, the success rate is 90 per cent. The technique allows uniform and more objective classification of very large extragalactic data sets

The Compact Group of Galaxies HCG 31 is in an early phase of merging

We have obtained high spectral resolution (R = 45900) Fabry-Perot velocity maps of the Hickson Compact Group HCG 31 in order to revisit the important problem of the merger nature of the central object A+C and to derive the internal kinematics of the candidate tidal dwarf galaxies in this group. Our main findings are: (1) double kinematic components are present throughout the main body of A+C, which strongly suggests that this complex is an ongoing merger (2) regions $A2$ and E, to the east and south of complex A+C, present rotation patterns with velocity amplitudes of $\sim 25 km s^{-1}$ and they counterrotate with respect to A+C, (3) region F, which was previously thought to be the best example of a tidal dwarf galaxy in HCG 31, presents no rotation and negligible internal velocity dispersion, as is also the case for region $A1$. HCG 31 presents an undergoing merger in its center (A+C) and it is likely that it has suffered additional perturbations due to interactions with the nearby galaxies B, G and Q.Comment: 5 pages + figures - Accepted to ApJ Lette

Optically Controlled Reconfigurable Filtenna

This work is regarding the development of a novel antenna called optically controlled reconfigurable filtenna, which is based on the integration of a broadband printed antenna with a bandpass reconfigurable RF filter. The filter is designed by applying defected microstrip structure (DMS) technique and positioned in printed antenna feeding line in order to keep the same size of the original antenna. The filtenna bandwidth is optically reconfigurable by using two photoconductive silicon switches excited by CW laser at 808 nm. Numerical results rely on independent and switchable operational modes through the 2.4 and 5.1 GHz ISM bands, whereas measurements demonstrate two reconfigurable modes based on single-band/dual-band operation over the same frequency bands. The proposed device is validated by theoretical, numerical, and experimental results

Influência do exercício físico sobre a pressão arterial, peso corporal, índice d massa corporal e circunferência da cintura

É amplamente reconhecida a relação entre hipertensão arterial e acident vascular cerebral, infarto agudo do miocárdio, insuficiência cardíaca, doença vascula periférica, dissecção da aorta e insufuciência renal crônica.A prevenção e o tratament precoce da hipertensão podem prevenir ou retardar esses eventos. OBJETIVOS: Reconhecer a existência e o grau de redução da pressão arterial, do pes corporal, do IMC e da medida da circunferência da cintura proporcionados pela atividad física regular. METODOLOGIA: Será realizado um estudo prospectivo com pacientes hipertensos e pré hipertensos em acompanhamento ambulatorial. Os sujeitos do estudo serão acompanhados por 6 meses. A medida da pressão arteri  será realizada pelo método auscultatório. O peso corporal e a estatura serão avaliados po meio de uma balança de precisão. O IMC será calculado por meio da divisão do peso pel estatura ao quadrado. A medida da Circunferência da cintura será efetuada com fit métrica na linha do umbigo. Os dados obtidos serão comparados com o objetivo de verificar se o grupo de sujeitos qu realizou atividade física apresentou melhor controle dos níveis pressóricos, do pes corporal, do IMC, e da circunferência da cintura

J-PLUS: Identification of low-metallicity stars with artificial neural networks using SPHINX

We present a new methodology for the estimation of stellar atmospheric parameters from narrow- and intermediate-band photometry of the Javalambre Photometric Local Universe Survey (J-PLUS), and propose a method for target pre-selection of low-metallicity stars for follow-up spectroscopic studies. Photometric metallicity estimates for stars in the globular cluster M15 are determined using this method. By development of a neural-network-based photometry pipeline, we aim to produce estimates of effective temperature, $T_{\rm eff}$, and metallicity, [Fe/H], for a large subset of stars in the J-PLUS footprint. The Stellar Photometric Index Network Explorer, SPHINX, is developed to produce estimates of $T_{\rm eff}$ and [Fe/H], after training on a combination of J-PLUS photometric inputs and synthetic magnitudes computed for medium-resolution (R ~ 2000) spectra of the Sloan Digital Sky Survey. This methodology is applied to J-PLUS photometry of the globular cluster M15. Effective temperature estimates made with J-PLUS Early Data Release photometry exhibit low scatter, \sigma($T_{\rm eff}$) = 91 K, over the temperature range 4500 < $T_{\rm eff}$ (K) < 8500. For stars from the J-PLUS First Data Release with 4500 < $T_{\rm eff}$ (K) < 6200, 85 $\pm$ 3% of stars known to have [Fe/H] <-2.0 are recovered by SPHINX. A mean metallicity of [Fe/H]=-2.32 $\pm$ 0.01, with a residual spread of 0.3 dex, is determined for M15 using J-PLUS photometry of 664 likely cluster members. We confirm the performance of SPHINX within the ranges specified, and verify its utility as a stand-alone tool for photometric estimation of effective temperature and metallicity, and for pre-selection of metal-poor spectroscopic targets.Comment: 18 pages, 12 figure

Two spectroscopically confirmed galaxy structures at z=0.61 and 0.74 in the CFHTLS Deep~3 field

Adami et al. (2010) have detected several cluster candidates at z>0.5 as part of a systematic search for clusters in the Canada France Hawaii Telescope Legacy Survey, based on photometric redshifts. We focus here on two of them, located in the D3 field: D3-6 and D3-43. We have obtained spectroscopy with Gemini/GMOS and measured redshifts for 23 and 14 galaxies in the two structures. These redshifts were combined with those available in the literature. A dynamical and a weak lensing analysis were also performed, together with the study of X-ray Chandra archive data. Cluster D3-6 is found to be a single structure of 8 spectroscopically confirmed members at an average redshift z=0.607, with a velocity dispersion of 423 km/s. It appears to be a relatively low mass cluster. D3-43-S3 has 46 spectroscopically confirmed members at an average redshift z=0.739. It can be decomposed into two main substructures, having a velocity dispersion of about 600 and 350 km/s. An explanation to the fact that D3-43-S3 is detected through weak lensing (only marginally, at the ~3sigma level) but not in X-rays could be that the two substructures are just beginning to merge more or less along the line of sight. We also show that D3-6 and D3-43-S3 have similar global galaxy luminosity functions, stellar mass functions, and star formation rate (SFR) distributions. The only differences are that D3-6 exhibits a lack of faint early type galaxies, a deficit of extremely high stellar mass galaxies compared to D3-43-S3, and an excess of very high SFR galaxies. This study shows the power of techniques based on photometric redshifts to detect low to moderately massive structures, even at z~0.75.Comment: Accepted in A&A, final version, shortened abstrac

Revisão bibliográfica do efeito da L-carnitina na redução de tecido adiposo em praticantes de exercício físico: mitos e verdades

A carnitina é uma amina quaternária, que quimicamente é formada pelos aminoácidos essenciais lisina e metionina. Apresenta duas formas que são os estereoisômeros: L-carnitina que é encontrada nos tecidos e D - carnitina que é a forma inativa da amina. A sua síntese se dá em órgãos de vital importância como fígado, rins e cérebro. Para sua produção são necessários o ferro, ácido ascórbico, niacina e vitamina B6. É notória a significativa atuação da mesma em efeitos de geração energética celular, promovendo o transporte de ácidos graxos livres (de cadeia média a longa) para a matriz mitocondrial, para participarem do processo denominado beta-oxidação. Como este processo possibilita a geração de elevada quantidade de substratos para o ciclo de Krebs, este determinará a maior formação de energia e aproveitamento do oxigênio molecular, poupando glicogênio muscular. Isto resulta em melhor desempenho na realização da atividade física. Há ainda estudos (Mingrone et al, 1999) que indicam que a L-carnitina possui papel no aumento da sensibilidade à insulina por atenuar o estresse oxidativo e acúmulo de lipídeos no músculo esquelético sensível à insulina. Com o objetivo de entender melhor o papel da L- carnitina, o presente trabalho visa fazer uma revisão bibliográfica de pesquisas que relacionem a suplementação com L-carnitina e redução do tecido adiposo em praticantes de exercício físico. O propósito é verificar se tal suplementação apresenta, de fato, resultados favoráveis que forneçam embasamento científico para o seu uso em praticantes de atividade física