Relationship between power decrease and swimming performance : a pilot study

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Inheritances, social classes, and wealth distribution

We consider a simple theoretical model to investigate the impact of inheritances on the wealth distribution. Wealth is described as a finite resource, which remains constant over different generations and is divided equally among offspring. All other sources of wealth are neglected. We consider different societies characterized by a different offspring probability distribution. We find that, if the population remains constant, the society reaches a stationary wealth distribution. We show that inequality emerges every time the number of children per family is not always the same. For realistic offspring distributions from developed countries, the model predicts a Gini coefficient of $G\approx 0.3$. If we divide the society into wealth classes and set the probability of getting married to depend on the distance between classes, the stationary wealth distribution crosses over from an exponential to a power-law regime as the number of wealth classes and the level of class distinction increase.Comment: 7 pages, 7 figure

Efeito de um treino de força em seco no desempenho em jovens nadadores

Em natação a performance depende da força e potência muscular (Newton et al., 2002) e a capacidade de exercer força na água é fundamental, especialmente em distâncias curtas (Morouço et al., 2011). Assim, os programas de treino de força em seco são comuns em natação ainda que o consenso sobre os benefícios específicos para o nadador ainda não tenha sido alcançado (Tanaka et al., 1993; Trappe and Pearson, 1994; Girold et al., 2007). Por um lado, várias investigações apresentaram melhorias na performance de nado após um programa de treino de força em seco (Strass, 1988; Girold et al., 2007; Aspenes et al., 2009; Girold et al., 2012). Por outro lado, várias investigações não apresentaram melhorias na performance de nado após um programa de treino de força em seco (Tanaka et al., 1993; Trappe and Pearson, 1994; Garrido et al., 2010; Sadowski et al., 2012). As razões para os resultados menos positivos podem dever-se a falhas nos protocolos de intervenção, tais como: especificidade do meio aquático (incapacidade de replicar os movimentos aquáticos em meio terrestre e a falta da resistência da água); escolha de exercícios pouco específicos ou que não solicitem os mesmos grupos musculares que o nado; velocidade de execução e cargas dos exercícios; amostra e os momentos das avaliações. As investigações com jovens nadadores são ainda mais escassas do que com adultos, o que revela alguma necessidade de investigação em torno deste assunto. Assim, os objetivos deste estudo foram examinar os efeitos de um programa de treino de força em seco: (i) na performance de nado e (ii) produção de força na água

Estudo da combinação dos padrões motores Correr e Largar e Pontapear sem ressalto, em crianças de 6 e 9 anos de idade

O objectivo deste estudo foi verificar se, com a idade, há um aumento na capacidade de combinar os padrões motores Correr e Largar e Pontapear sem ressalto e uma maior velocidade de saída da bola, na projecção da mesma a um alvo estacionário. Para tal, comparámos a performance, em crianças de 6 e 9 anos de idade, em termos quantitativos, do Largar e Pontapear sem ressalto parado, com o mesmo após breve corrida. Com efeito, as crianças de 9 anos revelaram ser capazes de combinar eficazmente o padrão Correr com o Largar e Pontapear sem ressalto, visível no aumento significativo da velocidade imprimida à bola nesta situação, comparativamente à execução parada, o que não se verificou com as crianças de 6 anos

Accommodating Maternal Age in CRIB Scale: Quantifying the Effect on the Classification

Receiver operating characteristic (ROC) curves are a well-accepted measure of accuracy of diagnostic tests using in continuous or ordinal markers. Based on the notion of using a threshold to classify subjects as positive (diseased) or negative (no diseased), a ROC curve is a plot of the true positive fraction (TPF) versus the false positive fraction (FPF) for all possible cut points. Thus, it describes the whole range of possible operating characteristic for the test and hence its inherent capacity for distinguish between two status. The clinical severity scale CRIB - Clinical Risk Index for Babies, emerged in 1993 to predict the mortality of newborn at less than 32 weeks of gestation and very low birth weight (< 1500gr) [4]. In previous work of Braga [3] this index was reported as showing a good performance in assessing risk of death for babies with very low birth weight (less than 1500 g weight). However, in some situations, the performance of the diagnostic test, the ROC curve itself and the Area Under the Curve(AUC) can be strongly influenced by the presence of covariates, whether continuous or categorical [5], [32], [33]. The World Health Organization and the Ministry of Health, defined as "late pregnancy" that thus occurs in women over 35 years. In this work, using the conditional ROC curve, we analyze the effect of one covariate, maternal age, on the ROC curve that representing the diagnostic test performance. We chose two age status, less than 35 years old and equal or greater than 35 years old, to verify the effects on the discriminating power of CRIB scale, in the process classification using R and STATA software.info:eu-repo/semantics/publishedVersio

The Creation of Defects with Core Condensation

Defects in superfluid 3He, high-Tc superconductors, QCD colour superfluids and cosmic vortons can possess (anti)ferromagnetic cores, and their generalisations. In each case there is a second order parameter whose value is zero in the bulk which does not vanish in the core. We examine the production of defects in the simplest 1+1 dimensional scalar theory in which a second order parameter can take non-zero values in a defect core. We study in detail the effects of core condensation on the defect production mechanism.Comment: 9 pages, 7 figures, small corrections, 2 references added, final version to be published in PR

Process intensification of gas-liquid flows with a novel constricted oscillatory-meso tube

GLD-8 - 8th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor EngineeringA novel constricted meso-tube (4.4. mm internal diameter) operated with oscillatory flow mixing has recently demonstrated enhanced volumetric mass transfer coefficients ( kLa) for continuous gas-liquid flows. Values of kLa up to 0.16 s-1 were obtained with a very low air-inflow rate (QG = 0.28 ml min-1) for the continuous running of a liquid phase (QL = 1.58 ml min-1), while in the presence of fluid oscillations. This is a one-order of magnitude improvement in the O2 transfer efficiencies in comparison with those values typically found for the most common-aerated reactors (e.g. stirred tank reactor, bubbles column, air-lift reactor). The design of novel multiphase, scaled-down reactors based on this novel tube’s geometry allows the intensification of gas-liquid flow processes through reducing the required processing volumes and the improved performance in terms of mixing, residence times and mass transfer. As a correct design does require a full understanding of the mass transfer processes, the different contributions of the mass transfer coefficient and the gas-liquid interfacial area in the global kLa enhancement were explored and herein reportedinfo:eu-repo/semantics/publishedVersio