618 research outputs found

    The retable of the chapel of Our Lady of Mercy in the cloister of Oporto’s Cathedral: study, conservation and restoration

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    The retable located in the Chapel of Our Lady of Mercy, in the cloisters of Oporto’s cathedral, dates back to the 17th century. Artistically, it belongs to a transition period between the Mannerism and the Baroque styles. The artistic value and the lack of documented information about the artwork led to the development of a project contemplating its the study. Both chemical and physical analyses - observation of the support, micro-FTIR and SEM-EDS - suggest that the retable was carved in sweet chestnut wood, accordingly to the techniques used at the time. The retable presents water-gilded areas contrasting with blue and red phytomorphic motifs. The polychromed areas were later covered with lead white paint. There were also evidences of previous conservation-restoration interventions. The frail condition of the retable’s materials testified the need to conserve and restore it. Among other procedures, the materials were consolidated and the lacunae were filled and inpainted - partially regenerating the artwork’s aesthetic unit

    In situ photobiology of corals over large depth ranges: A multivariate analysis on the roles of environment, host, and algal symbiont

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    We applied a multivariate analysis to investigate the roles of host and symbiont on the in situ physiological response of genus Madracis holobionts towards light. Across a large depth gradient (5–40 m) and for four Madracis species and three symbiont genotypes, we assessed several variables by measuring chlorophyll a fluorescence, photosynthetic pigment composition, or symbiont population descriptors. Most of the variation is explained by two major photobiological components: light-use efficiency and symbiont cell densities. Two other minor components emphasize photoprotective pathways and light-harvesting properties such as secondary pigments. Statistics highlight the role of irradiance on coral physiology and reveal mechanisms that are either genetically constrained, such as symbiont cell sizes, or environmentally dependent, such as photochemical efficiencies. Other parameters, such as cellular light-harvesting and photoprotective pigment concentrations, are regulated by host, symbiont, and environment. The interaction between host and environment stresses the role of host properties in adjusting the internal environment available for the endosymbionts. Different holobiont strategies, relating to symbiont cell density, vary in their physiological optimization of light-harvesting or photoprotective mechanisms and link to host-species distribution and dominance over the reef slope. Symbiont functional diversity appears to have a significant role but does not explain host vertical distribution patterns per se, highlighting the importance of species-specific morphological and physiological properties of the coral host

    Cardiac Doppler Variation with Volume Status Changes in General Intensive Care

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    Num grupo de 64 doentes de uma Unidade de Cuidados Intensivos, 24 dos quais submetidos a ventilação mecânica, foi determinada a influência da modificação da volémia nas características do Doppler cardíaco, através da negativização do balanço hídrico e correspondente modificação da pressão venosa central. Com a modificação da volémia, a relação E/A do fluxo transvalvular mitral mostrou uma tendência para reduzir, o tempo de desaceleração da onda E mitral para diminuir, o tempo de relaxamento isovolumétrico para aumentar, e a veia cava inferior reduziu o seu diâmetro expiratório e aumentou o valor do colapso inspiratório. Não se observou uma correlação significativa entre os valores das variáveis estudadas e a modificação da volémia, inclusivamente entre a pressão venosa central e o balanço hídrico. A modificação da volémia em doentes críticos modifica as características de determinados parâmetros de ecocardiografia- -Doppler, mas não é possível predizer a magnitude dessa variação

    Synthesis and fluorescence properties of side-chain carboxylated 5,9-diaminobenzo[a]phenoxazinium salts

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    The efficient synthesis of a series of novel side-chain carboxylated 5,9-diaminobenzo[a]phenoxazinium salts is described. The ring system was prepared by the reaction of 5-alkylamino-2-nitrosophenol hydrochlorides with the appropriate N-alkylated-naphthylamine. Evaluation of the visible and fluorescence properties of the cationic dyes was carried out in ethanol and water at physiological pH. In both solvents they showed intense visible absorption maxima in the range 500-638 nm (ethanol) and 625-650 (water), and fluoresced strongly, with fluorescence maxima from 612 to 669 nm (ethanol) and from 654 to 685 nm (water). A wide variation in fluorescence quantum yields is observed, ranging from 0.051 to 0.50 and 0.065 to 0.32 in ethanol and water, respectively.Fundação para a Ciência e a Tecnologia (FCT)

    The interplay of phonology and orthography in visual cognate word recognition: an ERP study

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    This study examined the role of phonological and orthographic overlap in the recognition of cognate words by recording electrophysiological and behavioral data. One hundred and ninety-two words were selected: 96 cognate words listed according to their phonological and orthographic overlap vs. 96 noncognate words. Twenty-four proficient European Portuguese-English bilinguals performed a silent reading task with a masked priming paradigm. The results showed that phonology interacts with semantic activation at N400 modulations. Phonological priming effects were dependent on the orthographic overlap of cognate words. Thus, the distinctive processing of cognate words seems to be due to their cross-linguistic similarity, which is consistent with a localist connectionist account on cognate representation and processing.The research reported in this paper wasfunded by FCT (Foundation for Science and Technology), by NSRF (National Strategic Reference Framework), by COMPETE (Operational Agenda for Competitiveness Factors), a program created by the EU as part of the European Regional Development Fund (ERDF), (PTDC/PSI-PCO/104671/2008) and by the Spanish Ministry of Education and Science (PSI2009–12616) and Plan E

    Social theory and the politics of big data and method

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    This article is an intervention in the debate on big data. It seeks to show, firstly, that behind the wager to make sociology more relevant to the digital there lies a coherent if essentially unstated vision and a whole stance which are more a symptom of the current world than a resolute endeavour to think that world through; hence the conclusion that the perspective prevailing in the debate lacks both the theoretical grip and the practical impulse to initiate a much needed renewal of social theory and sociology. Secondly, and more importantly, the article expounds an alternative view and shows by thus doing that other possibilities of engaging the digital can be pursued. The article is thus an invitation to widen the debate on big data and the digital and a call for a more combative social theory
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