Children and adolescents in front of screens: a paradigm shift in the relationship and mediation model

This paper reviews the major theories and research that analyze the relationship between children and screens. In addition, the agents which act as mediators that help children in the interpretation of the messages are considered. As a conclusion, it is observed that the new forms of multiscreen access used by children and adolescents have developed new consumption styles and that information and communication technologies (ICT) have resulted in new styles of interpersonal and group relationships. The impact of the multiscreen society should be analyzed in light of the role played by different mediators and by educommunication. Este artículo revisa las principales teorías e investigaciones que analizan la relación entre los niños y las pantallas. Además, se consideran los agentes que actúan como mediadores que ayudan a los niños en la interpretación de los mensajes. Como conclusión, se observa que las nuevas formas de acceso multipantalla utilizadas por niños y adolescentes han desarrollado nuevos estilos de consumo y que las tecnologías de la información y la comunicación (TIC) han dado lugar a nuevos estilos de relaciones interpersonales y grupales. El impacto de la sociedad de las pantallas debe analizarse a la luz del papel desempeñado por los diferentes mediadores y la educación

An attempt to quantify grapevine water stress in a mediterranean environment

Aiming to quantify the effects of the intensity and duration of grapevine water stress, physiological and agronomical data from an irrigation experiment conducted during 1999 at Alentejo, south of Portugal, with the red variety Aragonez (syn. Tempranillo) were correlated with an water stress index (Sψ). This index was calculated by the integral of predawn leaf water potential below –0.2 MPa between bloom and harvest. Significant relationships were found between the Sψ, yield components and berry composition. The multiple regression analysis shows that the Sψ in the period bloom-veraison has a higher contribution to explain the variation in berry weight, anthocyanins and phenolics concentration than the Sψ in the period veraison-harvest. The knowledge of those relationships, together with the relationship between available soil water content and predawn leaf water potential, may allow the adequate management of soil water availability to optimise the yield/quality ratio for each ecological situationinfo:eu-repo/semantics/publishedVersio

Relationships between leaf water potential and photosynthetic activity of field grapevines grown under different soil water regimes

Relationships between ecophysiological parameters from a grapevine irrigation experiment (rain-fed vs. deficit irrigation) conducted during 1998 at Alentejo, south of Portugal, with the red variety Aragonez (syn. Tempranillo) are presented and discussed. The irrigation affected positively grapevine physiology without changing berry composition. Predawn leaf water potential shows a significant dependence on available soil water, measured by a neutron probe, the correlation coefficients being higher in nonirrigated plants than in irrigated ones. Leaf water potential (Ψ) values measured in exposed leaves in the morning and afternoon were also significantly correlated with available soil water. Net CO2 assimilation rate (A) and stomatal conductance (gs) of sun leaves measured throughout the growing season at three different periods of the day were significantly correlated with predawn leaf water potential, nonirrigated vines presenting the highest correlation coefficients. Significant correlations were also found between Ψ and A or gs measured in the early morning. Our results show that, in water stress conditions, predawn leaf water potential can be used as an indicator of soil water availability and physiological activity of sun exposed leavesinfo:eu-repo/semantics/publishedVersio

Influência da rega na qualidade do vinho e perenidade da videira no Alentejo

Programa PAMAF-IED Acção de Investigação, Experimentação e DemonstraçãoEste projecto teve como objectivo avaliar os efeitos da utilização da rega na vinha, como complemento das disponibilidades hídricas do solo, na qualidade dos vinhos, no vigor e perenidade da videira na região do AlentejoN/

Rega da vinha no Alentejo. Dotações e época de aplicação

Apresenta-se um resumo dos principais resultados de três anos de ensaios (1997-99) de rega gota-a-gota na casta Aragonez em duas parcelas de vinha no Alentejo onde se compararam diferentes dotações e épocas de paragem da rega com uma testemunha não regada. Devido à maior capacidade de armazenamento de água do solo da parcela de Carvalhas (Estremoz) as diferenças ente modalidades foram, em qualquer dos anos, sempre de maior amplitude na parcela de Pinheiros, em Évora. Comparativamente à testemunha não regada, a rega reduziu a senescência foliar e induziu um efeito favorável no estado hídrico e na actividade fisiológica da folha ao longo de todo o dia, sobretudo durante o período de maturação e nas modalidades onde se aplicou maiores dotações de rega. Todavia, comparativamente à maior dotação, as menores dotações proporcionaram resultados agronómicos mais favoráveis. A paragem da rega ao pintor induziu um stress moderado e uma melhoria do microclima dos cachos durante o período de maturação, aspectos favoráveis à qualidade, sem ter afectado significativamente a produção comparativamente à rega até à vindimainfo:eu-repo/semantics/publishedVersio

Effects of T- and P-odd weak nucleon interaction in nuclei: renormalizations due to residual strong interaction, matrix elements between compound states and their correlations with P-violating matrix elements

Manifestations of P-,T-odd weak interaction between nucleons in nucleus are considered. Renormalization of this interaction due to residual strong interaction is studied. Mean squared matrix elements of P-,T-odd weak interaction between compound states are calculated. Correlators between P-,T-odd and P-odd, T-even weak interaction matrix elements between compound states are considered and estimates for these quantities are obtained.Comment: Submitted to Phys. Rev. C; 21 pages, REVTEX 3, no figure

Feature selection for spontaneous speech analysis to aid in Alzheimer’s disease diagnosis: A fractal dimension approach

Alzheimer’s disease (AD) is the most prevalent form of degenerative dementia; it has a high socio-economic impact in Westerncountries. The purpose of our project is to contribute to earlier diagnosis of AD and allow better estimates of its severity by usingautomatic analysis performed through new biomarkers extracted through non-invasive intelligent methods. The method selectedis based on speech biomarkers derived from the analysis of spontaneous speech (SS). Thus the main goal of the present work isfeature search in SS, aiming at pre-clinical evaluation whose results can be used to select appropriate tests for AD diagnosis. Thefeature set employed in our earlier work offered some hopeful conclusions but failed to capture the nonlinear dynamics of speechthat are present in the speech waveforms. The extra information provided by the nonlinear features could be especially useful whentraining data is limited. In this work, the fractal dimension (FD) of the observed time series is combined with linear parameters inthe feature vector in order to enhance the performance of the original system while controlling the computational cost.© 2014 Elsevier Ltd. All rights reserved