Precisión de diámetro abdominal sagital como predictor de la grasa abdominal en brasileños adultos: una comparación con la circunferencia de la cintura

Aim: We aim was to compare the sagittal abdominal diameter (SAD) with waist circumference (WC) as a predictor of central obesity among adults and to identify the sensitivity and specificity of the best cut-off point for SAD.Methods: A cross-sectional study of 266 Brazilians adults (euthrophic and overweight), aged 31-84 years old, of which 89 men and 177 women, was carried out. Anthropometric measurements such as SAD, weight, height, waist and hip circumferences, waist and hip ratio, body mass index, body fat percentage were performed. Receiver Operating Characteristics (ROC) curve was used to identify the sensitivity and specificity of the best cut off point for SAD as a predictor of central obesity. Statistical analysis were considered significant with a value of p < 0.05.Results: the SAD measurement was positively correlated with WC for both genders, although stronger among overweight and obesity women (r = 0.71; p < 0.001 and r = 0.79; p < 0.001, respectively) than men. ROC curves identified the best cut-off points for SAD of 23.1 cm and 20.1 cm for men and women (96% and 85% sensitivity, 86% and 84% specificity, respectively).Conclusion: SAD measurement may be used as an anthropometric tool to identify central obesity among women for presenting adequate sensitivity and specificity.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilSão Paulo State Univ UNESP, Dept Publ Hlth, Ctr Metab Exercise & Nutr CeMENutri, Botucatu, SP, BrazilPUC, Sch Nutr, Campinas, SP, BrazilSão Paulo State Univ UNESP, Dept Stat, Botucatu, SP, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilWeb of Scienc

Feeding practices and physical inactivity contributions to childhood overweight

OBJECTIVE: To review the literature in order to show how current feeding and physical activity practices may contribute to childhood overweight. DATA SOURCE: Ovid Journals, Highwire and SciELO, selecting original and review articles from 1997 to 2007, published in English and Portuguese. DATA SYNTHESIS: The periodic assessment of children nutritional status is important to diagnose their current health status and to predict their adult life prognosis. In Brazil, the prevalence of childhood obesity is progressively increasing in all social classes and its frequency varies from five to 18%, according to the region assessed. The association between the health, demographic and behavioral transition and the change in feeding practices can explain the increasing prevalence of childhood overweight. The current food consumption with high fat, sugar and sodium intake and low intake of whole cereals, fruits and vegetables associated to physical inactivity due to the excessive use of computers, electronic games and television may play a role in childhood obesity. This life style can be explained by changing family habits and school environment. CONCLUSIONS: These data suggest considerable influence of environmental factors, mainly nutritional habits and physical inactivity, on the increasing prevalence of childhood overweight.OBJETIVO: Revisar estudos que abordam as práticas alimentares atuais e o padrão de atividade física como contribuintes do excesso de peso na infância. FONTES DE DADOS: Ovid Journals, Highwire e SciELO, com seleção de artigos originais e de revisão nos últimos dez anos (1997 a 2007), na língua portuguesa e inglesa. SÍNTESE DE DADOS: O acompanhamento do estado nutricional de crianças permite diagnosticar seu estado de saúde atual, bem como predizer parcialmente seu prognóstico na vida adulta. A prevalência de obesidade infantil, no Brasil, apresenta aumento progressivo em todas as classes sociais e sua freqüência varia entre cinco a 18%, dependendo da região estudada. A associação da transição epidemiológica, demográfica e comportamental e a alteração do hábito alimentar são apontadas como fatores causais do aumento progressivo da obesidade infantil. Práticas alimentares caracterizadas por elevado teor de lipídios, sacarose e sódio e por reduzido consumo de cereais integrais, frutas e hortaliças associadas à inatividade física decorrente do uso de computadores, jogos eletrônicos e televisores influenciam parte considerável de crianças. Este estilo de vida reflete os hábitos familiares e pode ser influenciado pelo ambiente escolar no qual a criança está inserida. CONCLUSÕES: Os dados sugerem influência considerável dos fatores ambientais, principalmente hábitos alimentares e inatividade física, no crescente aumento da prevalência de excesso de peso na população pediátrica.Universidade Estadual Paulista Faculdade de Medicina de BotucatuUniversidade Federal do Rio de JaneiroUnesp FMB Departamento de PediatriaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUnesp FMBUNIFESP, EPM, Depto. de FisiologiaSciEL

Maximizing entropy of image models for 2-D constrained coding

This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite context models, which define stationary probability distributions on finite rectangles and thus allow for calculation of the entropy. We consider two binary constraints and revisit the hard square constraint given by forbidding neighboring 1s and provide novel results for the constraint that no uniform 2 £ 2 squares contains all 0s or all 1s. The maximum values of the entropy for the constraints are estimated and binary PRF satisfying the constraint are characterized and optimized w.r.t. the entropy. The maximum binary PRF entropy is 0.839 bits/symbol for the no uniform squares constraint. The entropy of the Markov random field defined by the 2-D constraint is estimated to be (upper bounded by) 0.8570 bits/symbol using the iterative technique of Belief Propagation on 2 £ 2 finite lattices. Based on combinatorial bounding techniques the maximum entropy for the constraint was determined to be 0.848

UV-Ozone reactor with modified high pressure mercury vapor lamp for surface treatment of transparent conductive oxides used in electroluminescent polymeric devices

An UV-Ozone reactor was developed with an ignition tube extracted into HID mercury lamp used to irradiation on zinc oxide (ZnO) and fluorinated tin oxide (FTO) films for PLEDs devices. Different exposures times were used. In contact angle measurements revealed better results for ZnO and FTO by 15 and 5 min, respectively. In Diffuse Reflectance Infra-red Fourier Transformed (DRIFT) spectroscopy allowed the observation of water, hydrocarbon and carbon dioxide adsorbed on the untreated TCO surfaces. After the UV-Ozone treatment the contaminants were significantly reduced or eliminated and the PLEDs devices decreased threshold voltages in comparison with respectively untreated TCOs

The supplementation of L-carnitine does not promote alterations in the resting metabolic rate and in the use of energetic substrates in physically active individuals

OBJETIVO: Avaliar o efeito da suplementação de L-carnitina, por 30 dias, sobre a taxa metabólica de repouso (TMR) e oxidação de ácidos graxos livres (AGL), em repouso e exercício. SUJEITOS E MÉTODOS: Vinte e um voluntários ativos (40 a 58 anos) com sobrepeso foram randomizados em dois grupos: suplementado (GS; N = 11; 1,8 g/dia de L-carnitina) e placebo (GP; N = 10; maltodextrina). Foi feita avaliação da ingestão calórica, antropometria, determinação da TMR, VO2máx, quociente respiratório e AGL plasmáticos. RESULTADOS: Não houve diferença significativa na ingestão (-244,66 vs. -126,00 kcal/dia), composição corporal (-0,07 vs. -0,17 kg/m²), TMR (0,06 vs. -0,02 kcal/ dia), quociente respiratório em repouso (3,69 vs. -1,01) e exercício (0,01 vs. -0,01) e VO2máx (0,50 vs. 1,25 mL/kg/min) para o grupo GS em relação ao GP. Houve aumento dos AGL em repouso no GP (0,27), porém sem diferenças no exercício para os grupos. CONCLUSÃO: Não houve efeito da L-carnitina em nenhuma das variáveis analisadas no estudo.PURPOSE: To investigate the effects of L-carnitine supplementation, over thirty days, on the resting metabolic rate (RMR) and oxidation of free fatty acids (FFA) under rested or exercised conditions. SUBJECTS AND METHODS: Twenty-one overweight active volunteers (40 to 58 years old) were randomized into two groups: supplemented (GS; N = 11; 1,8 g/day of L-carnitine) or placebo (GP; N = 10; maltodextrin). Caloric intake, anthropometry, RMR, VO2max, respiratory exchange ratio and plasma FFA were measured. RESULTS: No significant changes were found in the caloric intake (-244,66 vs. -126,00 kcal/day), body composition (-0.07 vs. -0.17 kg/m²), RMR (0.06 vs. -0.02 kcal/day), respiratory exchange ratio at rest (3.69 vs. -1.01) and exercise (0.01 vs. -0.01) or VO2max (0.50 vs. 1.25 mL/kg/min) between GS and GP. Plasma FFA levels were increased under resting conditions only in the GP group (0.27), but no significant changes were observed before or after physical activity in any of the groups. CONCLUSION: Supplementation with L-carnitine caused no changes in the variables analyzed in this study