Características psicométricas da versão portuguesa da escala de Socialização Parental na Adolescência ESPA-29 / Psychometric properties of the portuguese version of the Parental Socialization Scale in Adolescence (ESPA-29)

O objetivo do estudo foi validar a versão portuguesa da Escala de Estilos de Socialização Parental na Adolescência (ESPA-29) de Musitu e García (2001, 2004). Participaram 849 adolescentes de ambos os sexos (57,2% raparigas e 42,8% rapazes), com idades compreendidas entre os 10 e os 18 anos (M = 14,57, DP = 2,43) e residentes no sul de Portugal. A validade de constructo foi estudada através da análise fatorial exploratória e a fidelidade do instrumento através da análise da consistência interna e da estabilidade temporal (pelo método de teste-reteste). Os resultados obtidos foram consistentes com os da versão original e reproduziram a estrutura bidimensional da escala. A versão portuguesa da ESPA-29 apresentou boas características psicométricas, com níveis de consistência interna e de estabilidade temporal bastante satisfatórias. Estes resultados sugerem que a versão portuguesa da ESPA-29 é fiável para o estudo dos estilos de socialização parental em adolescentes portugueses. (AU)

The aim of this study was to validate the Portuguese version of the Parental Socialization Scale in Adolescence (ESPA-29) by Musitu and García (2001, 2004). A sample of 849 adolescents (57.2% girls and 42.8% boys), aged 10 to 18 years (M = 14.57, SD = 2.43), from the southern region of Portugal, participated in the study. Construct validity was studied using exploratory factor analysis, and the reliability study was conducted through the analysis of internal consistency and temporal stability (through the test-retest method). Results were consistent with those obtained in the original version of the instrument and reproduced the bi-dimensional structure of the scale. Furthermore, the Portuguese version of ESPA-29 showed good psychometric characteristics, with satisfactory levels of internal consistency and temporal stability. These results suggest that this is a reliable instrument for studying parental socialization styles in Portuguese adolescents. (AU)

Efficient dechlorination of carbon tetrachloride by hydrophobic green rust intercalated with dodecanoate anions.

The reductive dechlorination of carbon tetrachloride (CT) by Fe(II)-Fe(III) hydroxide (green rust) intercalated with dodecanoate, Fe(II)(4)Fe(III)(2)(OH)(12)(C(12)H(23)O(2))(2) · yH(2)O (designated GR(C12)), at pH ~ 8 and at room temperature was investigated. CT at concentration levels similar to those found in heavily contaminated groundwater close to polluted industrial sites (14-988 µM) was reduced mainly to the fully dechlorinated products carbon monoxide (CO, yields >54%) and formic acid (HCOOH, yields >6%). Minor formation of chloroform (CF), the only chlorinated degradation product, was also detected (yields <6.3%). Reactions carried out with excess GR followed pseudo first-order kinetics with respect to CT with rate constants ranging from 6.5 × 10(-2) to 0.47 h(-1). These rate constants are comparable to those measured for CT dechlorinations mediated by zerovalent iron. Reduction of the highest concentration of CT (1.4 mM) proceeds until 56% of the Fe(II) sites of GR(C12) was consumed. This reaction ceased after 10 h due to surface passivation of GR(C12).

Kinetics of ptaquiloside hydrolysis in aqueous solution.

Ptaquiloside (PTA) is a well-known toxin produced by the bracken fern (Pteridium aquilinum (L.) Kuhn). It is proposed that PTA from bracken stands can leach through soil and sediments into drinking-water reservoirs, thus representing a concern for human health. To predict the persistence of the toxin, a full understanding of the PTA degradation in aqueous environments is important. The kinetics of PTA hydrolysis was examined at 22 degrees C in aqueous buffered solutions (pH 2.88-8.93). The reaction was found to follow first-order kinetics with respect to PTA at all pH and temperature conditions. At pH lower than 4.43 (+/- 0.32), the reaction is acid-mediated, whereas the reaction is base-mediated at pH higher than 6.39 (+/- 0.28). The rate constants for the acid-catalyzed, base-catalyzed, and neutral hydrolysis are 25.70 (+/- 0.96), 4.83 (+/- 0.03) X 10(4), and 9.49 (+/- 6.02) x 10(-4) h(-1), respectively. The PTA hydrolysis at pH 4.46 is strongly dependent on temperature, with an activation energy of 74.4 (+/- 2.6) kJ mol(-1). Stoichiometric calculations, reaction kinetics, and ultraviolet-visible spectrophotometry strongly indicates the formation of an intermediary compound at pH 5.07 and 6.07 via a mechanism comprising two first-order consecutive reactions. Ptaquiloside has the lowest rate of hydrolysis at slightly acidic pH and low temperatures. Therefore, because PTA is not sorbed in soil, slightly acidic sandy soils in cold climates are most prone to PTA leaching to deeper soil layers and aquifers.