227 resultados para Hajdú, Péter


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Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5–10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality.

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School geography is often quite different from academic geography and there are good reasons for that, as school is preparing young people to be able to lead the life they value instead of just training them to learn specific subject contents. In some countries school geography is understood as being mainly a social science. Nonetheless physical geography often plays an important part in textbooks and in everyday teaching in these countries. This presentation will examine how physical geography topics are justified in specialist teacher magazines in Germany. Are they justified by simply pointing at the value of the academic knowledge itself? Are they justified by claiming students’ special interest in these topics? Or are they justified by showing the value of physical geography in promoting social aims such as sustainable development, freedom or equality?