Validation and adaptation of the Physical Activity Enjoyment Scale (PACES) in fitness group exercisers

Background: Recently, Mullen et al. (2011) presented an 8-item version of the Physical Activity Enjoyment Scale (PACES) providing a valid instrument for assessing enjoyment in physical activity. The present paper investigated the psychometric properties of a Portuguese adaptation of PACES.Methods: After a process of back-to-back translation into Portuguese, 395 members of fitness centers who ranged in age from 18 to 66 years (31.11 ± 8.90, mean ± SD) completed the translated version of the PACES. On average, participants had 3.2 years of experience in fitness group classes and practiced for approximately 3.3 times per week.Results: An initial exploratory factor analysis (n = 139) revealed a unidimensional structure with factor loadings ranging from 0.79 to 0.89. Results also showed acceptable internal consistency. A confirmatory factor analysis in an independent sample (n = 256) provided additional support for the unidimensional structure of the questionnaire. In addition, moderate positive correlations between enjoyment and intrinsic and identified regulation, and moderate negative correlations between enjoyment and external and amotivation demonstrate the convergent validity of the instrument. Finally, measurement invariance between two independent samples was also found.Conclusion: The 8-item Portuguese version of PACES is a valid and reliable instrument for measuring enjoyment of physical activity in Portuguese adult's fitness exercisers, therefore suitable to use as a measure of affect in exercise adherence interventions studies

Estratégia h-adaptativa para a análise elasto-plástica bidimensional

Neste trabalho apresenta-se uma estratégia h-adaptativa para problemas de elasticidade bidimensional, discretizados por elementos finitos triangulares lineares, considerando a nao linearidade do material. Esta estratégia é baseada na técnica de remalhamento (remeshing) onde, através de estimativa de erro a posteriori, se prediz o tamanho do elemento necessário para atingir um nível de precisao pré-especificado. O comportamento nao linear do material é tratado através do modelo de subcamadas, nao se limitando portanto a modelos bilineares.Peer Reviewe

Estratégia h-adaptativa para a análise elasto-plástica bidimensional

Neste trabalho apresenta-se uma estratégia h-adaptativa para problemas de elasticidade bidimensional, discretizados por elementos finitos triangulares lineares, considerando a nao linearidade do material. Esta estratégia é baseada na técnica de remalhamento (remeshing) onde, através de estimativa de erro a posteriori, se prediz o tamanho do elemento necessário para atingir um nível de precisao pré-especificado. O comportamento nao linear do material é tratado através do modelo de subcamadas, nao se limitando portanto a modelos bilineares.Peer Reviewe

Presence of stratospheric humidity in the ozone column depletion on the west coast of South America

The ozone column depletion over the western coast of South America has been previously explained, based on the existence of winds in the area of the depletion, which cause compression and thinning of the ozone layer. However, the presence of humidity and methane transported by these winds to the stratosphere where the ozone depletion is present gives evidence that these compounds also participate in the depletion of the ozone layer. These two compounds, humidity and methane, are analysed during the ozone depletion of January, 1998. It is observed that when humidity presents fluctuations, ozone has fluctuations too. A maximum of humidity corresponds to a minimum of ozone, but there is a shift in altitude between them. This shift is observed in the stratosphere and upper troposphere and corresponds to approximately 500 m. It is important to point out that during this event El Ni˜no was present and the sources of methane are the Amazon forest and the Pacific Ocean. The data for this study was obtained from NASA and HALOE