José Pedro Silva

Degradation of UV filters 2-ethylhexyl-4-methoxycinnamate and 4-tert-butyl-4′-methoxydibenzoylmethane in chlorinated water

Environmental context The increasing use of sun-creams containing UV-filtering chemicals has led to increased inputs of these compounds to the aquatic environment. Chlorinated waters can convert these chemicals into chlorinated products whose toxic effects are of primary concern. To better understand the environmental fate of sun-cream chemicals, we studied the stability of two UV-filtering compounds under varying conditions of pH, chlorine concentration, temperature, dissolved organic matter and solar irradiation. Abstract The stability of the UV filters 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-tert-butyl-4′-methoxydibenzoylmethane (BDM) in chlorinated water was studied. High-performance liquid chromatography (HPLC)-UV-diode array detection (DAD) was used to follow the reaction kinetics of both UV filters and HPLC-tandem mass spectrometry (MS/MS) was used to tentatively identify the major transformation by-products. Under the experimental conditions used in this work both UV filters reacted with chlorine following pseudo-first order kinetics: rate constant k=0.0095±0.0007min–1 and half-life t1/2=73±4min for EHMC and rate constant k=0.006±0.001min–1 and half-life t1/2=119±14min for BDM (mean±standard deviation). The chemical transformation of the UV filters in chlorinated water led to the formation of chlorinated by-products that were tentatively identified as mono- and dichloro-substituted compounds that resulted from substitution of the hydrogen atoms in the benzene rings by one or two chlorine atoms. Experimental Box–Behnken designs were used to assess the effect of experimental factors: pH, temperature, chlorine concentration, dissolved organic matter and artificial sunlight irradiation on the transformation of the UV filters.

Encapsulation of probiotic strains in plain or cysteine‐supplemented alginate improves viability at storage below freezing temperatures

Four probiotic bacteria (Lactobacillus paracasei L26, L. casei‐01, L. acidophilus Ki, and Bifidobacterium animalis BB‐12®) were encapsulated in plain alginate or alginate supplemented with L‐cysteine·HCl, and resulting microcapsules were stored at different temperatures, namely 21, 4, −20, or −80°C for a period of up to 6 months. The results showed that the encapsulation in calcium alginate microcapsules was only effective in promoting protection at freezing temperatures, independently of the sensitivity of the strain. Storage of calcium alginate microcapsules at −80°C indicated a protective effect upon viability of all four probiotic strains and the presence of L‐cysteine·HCl in the alginate matrix improved protection upon cell viability of B. animalis BB‐12®. An increase in storage temperature of encapsulated bacteria caused an increase in rate of loss in their viability that was strain dependent. This study suggests that microencapsulation of probiotic cells in calcium alginate can be suitable for sustaining the viability of probiotics in food products that require storage below freezing temperatures, even in the absence of cryoprotectors, contributing to an increased shelf life.

L’émigration portugaise qualifiée dans le contexte européen

Devant le renouvellement de l’emigration portugaise en Europe, une enquete realisee en 2014 fait le point sur les representations que les migrants portent sur leur propre parcours. La distinction de differents facteurs de repulsion pour leur pays d’origine et d’attraction pour le pays de destination permet d’esquisser les nouveaux visages des migrants portugais, plus qualifies que leurs predecesseurs, tres informes sur les perspectives professionnelles de mobilite. Envisageant leur depart davantage comme une experience de vie qu’une situation d’emigration, ils contribuent a redefinir les contours transnationaux de l’Europe contemporaine.

The decision to emigrate: a study from the perspective of dispositional plurality

This paper analyses the Portuguese high-skilled emigration, focusing on the emigration decision-making process. This article aims to understand the dispositions leading to this decision, and the social processes that explain its origin, sedimentation and activation. To this end, and using the theoretical and methodological approach of Bernard Lahire, 53 sociological portraits of skilled Portuguese who emigrated to other European countries are cross-sectional analyzed. This analysis is supplemented by data from a survey previously administered. Thus, we will address how the migratory dispositions are built through the individual biographies, highlighting the heuristic potential of the individual observation scale.Este artigo analisa a emigracao portuguesa qualificada, focando-se sobre a producao da decisao de emigrar. E seu objetivo compreender as disposicoes que conduzem a essa decisao, bem como os processos sociais que explicam a sua genese, sedimentacao e ativacao. Para isso, e recorrendo a proposta teorica e metodologica de Bernard Lahire, procede-se a analise transversal de 53 retratos sociologicos de portugueses qualificados que emigraram para outros paises europeus, complementada pelos dados de um inquerito administrado previamente. Deste modo, daremos conta da forma como as disposicoes migratorias se constroem atraves dos percursos biograficos, ressaltando as potencialidades heuristicas da escala individual de observacao.

A decisão de emigrar : um estudo a partir da perspetiva da pluralidade

This paper analyses the Portuguese high-skilled emigration, focusing on the emigration decision-making process. This article aims to understand the dispositions leading to this decision, and the social processes that explain its origin, sedimentation and activation. To this end, and using the theoretical and methodological approach of Bernard Lahire, 53 sociological portraits of skilled Portuguese who emigrated to other European countries are cross-sectional analyzed. This analysis is supplemented by data from a survey previously administered. Thus, we will address how the migratory dispositions are built through the individual biographies, highlighting the heuristic potential of the individual observation scale.Este artigo analisa a emigracao portuguesa qualificada, focando-se sobre a producao da decisao de emigrar. E seu objetivo compreender as disposicoes que conduzem a essa decisao, bem como os processos sociais que explicam a sua genese, sedimentacao e ativacao. Para isso, e recorrendo a proposta teorica e metodologica de Bernard Lahire, procede-se a analise transversal de 53 retratos sociologicos de portugueses qualificados que emigraram para outros paises europeus, complementada pelos dados de um inquerito administrado previamente. Deste modo, daremos conta da forma como as disposicoes migratorias se constroem atraves dos percursos biograficos, ressaltando as potencialidades heuristicas da escala individual de observacao.

A decisão de emigrar: um estudo a partir da perspetiva da pluralidade disposicional

This paper analyses the Portuguese high-skilled emigration, focusing on the emigration decision-making process. This article aims to understand the dispositions leading to this decision, and the social processes that explain its origin, sedimentation and activation. To this end, and using the theoretical and methodological approach of Bernard Lahire, 53 sociological portraits of skilled Portuguese who emigrated to other European countries are cross-sectional analyzed. This analysis is supplemented by data from a survey previously administered. Thus, we will address how the migratory dispositions are built through the individual biographies, highlighting the heuristic potential of the individual observation scale.Este artigo analisa a emigracao portuguesa qualificada, focando-se sobre a producao da decisao de emigrar. E seu objetivo compreender as disposicoes que conduzem a essa decisao, bem como os processos sociais que explicam a sua genese, sedimentacao e ativacao. Para isso, e recorrendo a proposta teorica e metodologica de Bernard Lahire, procede-se a analise transversal de 53 retratos sociologicos de portugueses qualificados que emigraram para outros paises europeus, complementada pelos dados de um inquerito administrado previamente. Deste modo, daremos conta da forma como as disposicoes migratorias se constroem atraves dos percursos biograficos, ressaltando as potencialidades heuristicas da escala individual de observacao.