To evaluate the influence of upwelling events on nitrous oxide (N2O) levels and sea-air exchange in Setúbal Bay (SW Portugal), measurements of dissolved N2O were carried out from the surface down to 200 m depth in May 2006 and May 2007. During the weak upwelling event (May 2006), higher N2O concentrations (values up to 14 nmol L-1) were observed in the upper and deeper layers. In the upper layers a positive correlation between ΔN2O (N2O excess) and apparent oxygen utilization was calculated, suggesting that nitrification contributed to N2O production. During the stronger upwelling event (May 2007), N2O values were lower and did not surpass 12 nmol L-1. Production of N2O could not be disentangled and apparently upwelling provided an effective pathway for ventilating N2O from subsurface waters to the atmosphere. Surface waters were, in general, supersaturated with respect to the atmosphere (percent saturation values 95-160%), indicating that the study area was acting as a source of atmospheric N2O. Higher upwelling-favorable winds (values up to 9 m s-1) registered in May 2007 contributed to increase N2O emissions, which attained a maximum value of 15.2 µmol m-2 d-1 in this period. Lower N2O sea-air fluxes were estimated in May 2006 and values did not surpass 8.8 µmol m-2 d-1. Taking into account the N2O flux in our study area, the contribution of Portuguese coastal upwelling to N2O emission was estimated, varying from 0.040 to 0.102 Gg N yr-1. These values are lower than those reported for most upwelling systems and represent a minor source to atmospheric N2O.

Para evaluar la influencia de los eventos de surgencia en las concentraciones y flujos a la atmósfera del óxido de nitrógeno disuelto (N2O) en la bahía de Setúbal (SO de Portugal), se midió el N2O desde la superficie hasta una profundidad de 200 m en mayo de 2006 y mayo de 2007. Durante el afloramiento débil (mayo de 2006), las mayores concentraciones de N2O (valores de hasta 14 nmol L-1) fueron observadas en la capa superior y la capa más profunda de la columna de agua. En las capas superiores se detectó una correlación positiva entre el ΔN2O (exceso de N2O) y el consumo aparente de oxígeno, lo que sugiere que la nitrificación contribuyó a la producción de N2O. Durante el evento de surgencia más fuerte (mayo de 2007), las concentraciones de N2O disuelto fueron menores y no rebasaron los 12 nmol L-1. No fue posible definir el proceso de producción de N2O, y el afloramiento parece haber sido una forma eficiente de ventilación del N2O a la atmósfera. En general, las aguas superficiales estuvieron sobresaturadas en N2O con respecto a la atmósfera (saturación de 95 a 160%), lo que indica que el área de estudio estaba actuando como una fuente de N2O atmosférico. Vientos más fuertes y favorables a las surgencias, registrados en mayo de 2007 (de hasta 9 m s-1), contribuyeron al aumento de las emisiones de N2O, que alcanzaron valores de hasta 15.2 µmol m-2 d-1 en dicho periodo. En mayo de 2006 se estimaron los flujos más bajos de N2O a la atmósfera, que no superaron 8.8 µmol m-2 d-1. Teniendo en cuenta el flujo de N2O del área de estudio, se estima que la surgencia costera portuguesa cotribuye con una emisión de N2O entre 0.040 y 0.102 Gg N año-1. Estos valores son inferiores a los de la mayoría de los sistemas de surgencia, por lo que representan una fuente menor de N2O atmosférico.

OBJETIVO: Avaliar como as características demográficas, sociais e comportamentais se associam a diferentes tipos de atividade física. MÉTODOS: Avaliaram-se 37.692 indivíduos de amostra representativa da população portuguesa, no âmbito do Inquérito Nacional de Saúde, 1998-99. A maioria era constituída por mulheres (53,1%) e idade 20 anos. A avaliação da atividade física diária foi baseada em questionário e classificada como: total, de lazer e exercício. Cada tipo foi dicotomizado em baixa intensidade (atividades leves/moderadas) e alta intensidade (atividades pesadas/muito pesadas). Calcularam-se odds ratios (OR) e respectivos intervalos de confiança de 95% por regressão logística não condicional. RESULTADOS: Em ambos os sexos, verificou-se associação inversa significativa entre idade e diferentes tipos de atividade física, e entre a obesidade e a atividade de lazer e exercício. A escolaridade (<4; 5-11; 12 anos) associou-se positivamente com a atividade física de lazer (OR 1; 1,58; 2,39 nas mulheres e OR 1; 1,44; 2,08 nos homens) e com o exercício (OR 1; 3,50; 9,77 nas mulheres e OR 1; 3,42; 7,61 nos homens) e de forma inversa com a AF total (OR 1; 0,65; 0,20 nas mulheres e 1; 0,47; 0,09 nos homens). Independentemente da idade, os solteiros eram frequentemente mais ativos. A atividade de lazer associou-se negativamente ao consumo de bebidas alcoólicas para ambos os sexos e nos homens, ao consumo de tabaco. CONCLUSÕES: Os jovens, normoponderais, solteiros, não-bebedores e os homens não-fumadores apresentaram maior probabilidade de serem fisicamente ativos. Em ambos os sexos, observou-se um efeito diferencial da escolaridade segundo os tipos de atividade física.

OBJECTIVE: To evaluate the association between demographic, social and behavior characteristics and different types of physical activity. METHODS: A total of 37.692 subjects of a representative sample of the Portuguese population were studied as part of the National Health Survey in 1998 and 1999. Most were females (53.1%) aged >20 years. Daily physical activity was self-reported based on a questionnaire and discriminated in different types: total physical activity, leisure-time and exercise. Each type of physical activity was dichotomized into low (light/moderate) and high intensity (heavy/very heavy). Odds ratios (OR) and 95% confidence intervals were estimated using unconditional logistic regression. RESULTS: In both men and women, a significant inverse association between age and different types of physical activity and between obesity and leisure time physical activity and exercise was seen. A positive association was found between education (<4; 5-11; 12 years) and leisure-time PA (OR 1; 1.58; 2.39 in females and 1; 1.44; 2.08 in males) and exercise (OR 1; 3.50; 9.77 in females and 1; 3.42; 7.61 in males) and an inverse association with total physical activity (OR 1; 0.65; 0.20 in females and 1; 0.47; 0.09 in males) was found. Regardless of age, single subjects were frequently more active. Alcohol consumption in both men and women and tobacco consumption in males were negatively associated with leisure-time physical activity. CONCLUSIONS: Youngest, normal weighted, single, non-drinkers subjects and non-smokers males were more likely to be physically active. In both men and women, there was a clear effect of education on the type of physical activity.

OBJETIVO: Avaliar como as características demográficas, sociais e comportamentais se associam a diferentes tipos de atividade física. MÉTODOS: Avaliaram-se 37.692 indivíduos de amostra representativa da população portuguesa, no âmbito do Inquérito Nacional de Saúde, 1998-99. A maioria era constituída por mulheres (53,1%) e idade 20 anos. A avaliação da atividade física diária foi baseada em questionário e classificada como: total, de lazer e exercício. Cada tipo foi dicotomizado em baixa intensidade (atividades leves/moderadas) e alta intensidade (atividades pesadas/muito pesadas). Calcularam-se odds ratios (OR) e respectivos intervalos de confiança de 95% por regressão logística não condicional. RESULTADOS: Em ambos os sexos, verificou-se associação inversa significativa entre idade e diferentes tipos de atividade física, e entre a obesidade e a atividade de lazer e exercício. A escolaridade (<4; 5-11; 12 anos) associou-se positivamente com a atividade física de lazer (OR 1; 1,58; 2,39 nas mulheres e OR 1; 1,44; 2,08 nos homens) e com o exercício (OR 1; 3,50; 9,77 nas mulheres e OR 1; 3,42; 7,61 nos homens) e de forma inversa com a AF total (OR 1; 0,65; 0,20 nas mulheres e 1; 0,47; 0,09 nos homens). Independentemente da idade, os solteiros eram frequentemente mais ativos. A atividade de lazer associou-se negativamente ao consumo de bebidas alcoólicas para ambos os sexos e nos homens, ao consumo de tabaco. CONCLUSÕES: Os jovens, normoponderais, solteiros, não-bebedores e os homens não-fumadores apresentaram maior probabilidade de serem fisicamente ativos. Em ambos os sexos, observou-se um efeito diferencial da escolaridade segundo os tipos de atividade física.

OBJECTIVE: To evaluate the association between demographic, social and behavior characteristics and different types of physical activity. METHODS: A total of 37.692 subjects of a representative sample of the Portuguese population were studied as part of the National Health Survey in 1998 and 1999. Most were females (53.1%) aged >20 years. Daily physical activity was self-reported based on a questionnaire and discriminated in different types: total physical activity, leisure-time and exercise. Each type of physical activity was dichotomized into low (light/moderate) and high intensity (heavy/very heavy). Odds ratios (OR) and 95% confidence intervals were estimated using unconditional logistic regression. RESULTS: In both men and women, a significant inverse association between age and different types of physical activity and between obesity and leisure time physical activity and exercise was seen. A positive association was found between education (<4; 5-11; 12 years) and leisure-time PA (OR 1; 1.58; 2.39 in females and 1; 1.44; 2.08 in males) and exercise (OR 1; 3.50; 9.77 in females and 1; 3.42; 7.61 in males) and an inverse association with total physical activity (OR 1; 0.65; 0.20 in females and 1; 0.47; 0.09 in males) was found. Regardless of age, single subjects were frequently more active. Alcohol consumption in both men and women and tobacco consumption in males were negatively associated with leisure-time physical activity. CONCLUSIONS: Youngest, normal weighted, single, non-drinkers subjects and non-smokers males were more likely to be physically active. In both men and women, there was a clear effect of education on the type of physical activity.