736 research outputs found

    La difusión de la prensa diaria en los Paises Catalanes entre 1976-1996

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    Esta investigación analiza la evolución de la difusión de la prensa diaria en relación a la vertebración política de los territorios de Cataluña, Islas Baleares y País Valenciano con el conjunto del estado, desde el principio de la transición a la democracia en 1976 hasta 1996. Las principales conclusiones apuntan a un incremento de la vertebración estatal de estos territorios, especialmente en cuanto a su dependencia informativa provocada por el incremento muy significativo de la prensa central de penetración en cuanto a ventas totales, tasas de difusión y ocupación del mercado. El estado de las Autonomías se revela, pues, no como un factor de mayor autonomía informativa territorial, sino de integración y homogeneización.This study analyses generic processes affecting the various tiers of the daily press in relation to the evolution of the political structuring of the Catalanspeaking areas (Catalonia, Balearic Islands and Valencian Community) within the Spanish State, from the beginning of the transition to democracy in 1976 through to 1996. The major movements to be detected in press diffusion are the increase in the "vertebration" of the Spanish state as a whole, evident as much in the increased weight of the centralised statewide press penetrating the Catalanspeaking market as in the process of homogenisation revealed by key data referring to total sales, circulation density and market shares

    Enzyme contribution of non-Saccharomyces yeasts to wine production

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    The fermentation of grape must to produce wine is a biologically complex process, carried on by yeasts and malolactic bacteria. The yeasts present in spontaneous fermentation may be divided into two groups, the Saccharomyces yeasts, particularly S. cerevisiae, and the non-Saccharomyces yeasts which include members of the genera Rhodotorula, Pichia, Candida, Debaryomyces, Metschtnikowia, Hansenula and Hanseniaspora. S. cerevisiae yeasts are able to convert sugar into ethanol and CO2 via fermentation. They have been used for thousands of years by mankind for the production of fermented beverages and foods, including wine. Their enzymes provide interesting wine organoleptic characteristics. β-Glucosidase activity is involved in the release of terpenes to wine, thus contributing to varietal aroma. β-Xylosidase enzyme is also interesting in industry due to its involvement in the degradation of hemicellulose by hydrolyzing its main heteroglycan (xylan). The ability of yeasts to release proteases has been observed by many researchers because of their potential to degrade haze proteins in wine and to generate nutrient sources for microorganisms. Moreover, these enzymes are interesting in biotechnology, for use in food processing such as cheese, pickles or sausage

    Distribution of lipid biomarkers and carbon isotope fractionation in contrasting trophic environments of the South East Pacific

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    The distribution of lipid biomarkers and their stable carbon isotope composition was investigated on suspended particles from different contrasting trophic environments at six sites in the South East Pacific. High algal biomass with diatom-related lipids (24-methylcholesta-5,24(28)-dien-3β-ol, C<sub>25</sub> HBI alkenes, C<sub>16:4</sub> FA, C<sub>20:5</sub> FA) was characteristic in the upwelling zone, whereas haptophyte lipids (long-chain (C<sub>37</sub>-C<sub>39</sub>) unsaturated ketones) were proportionally most abundant in the nutrient-poor settings of the centre of the South Pacific Gyre and on its easter edge. The dinoflagellate–sterol, 4α-23,24-trimethylcholest-22(<i>E</i>)-en-3β-ol, was a minor contributor in all of the studied area and the cyanobacteria-hydrocarbon, C<sub>17</sub><i>n</i>-alkane, was at maximum in the high nutrient low chlorophyll regime of the subequatorial waters near the Marquesas archipelago. <br><br> The taxonomic and spatial variability of the relationships between carbon photosynthetic fractionation and environmental conditions for four specific algal taxa (diatoms, haptophytes, dinoflagellates and cyanobacteria) was also investigated. The carbon isotope fractionation factor (ε<sub>p</sub>) of the 24-methylcholesta-5,24(28)-dien-3β-ol diatom marker, varied over a range of 16% along the different trophic systems. In contrast, ε<sub>p</sub> of dinoflagellate, cyanobacteria and alkenone markers varied only by 7–10‰. The low fractionation factors and small variations between the different phytoplankton markers measured in the upwelling area likely reveals uniformly high specific growth rates within the four phytoplankton taxa, and/or that transport of inorganic carbon into phytoplankton cells may not only occur by diffusion but also by other carbon concentrating mechanisms (CCM). In contrast, in the oligotrophic zone, i.e. gyre and eastgyre, relatively high ε<sub>p</sub> values, especially for the diatom marker, indicate diffusive CO<sub>2</sub> uptake by the eukaryotic phytoplankton. At these nutrient-poor sites, the lower ε<sub>p</sub> values for haptophytes, dinoflagellates and cyanobacteria indicate higher growth rates or major differences on the carbon uptake mechanisms compared to diatoms

    Ecology and biogeochemistry of contrasting trophic environments in the South East Pacific by carbon isotope ratios on lipid biomarkers

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    International audienceThe distribution of lipid biomarkers and their carbon isotope composition was investigated on suspended particles from different contrasting trophic environments at six sites in the South East Pacific. High algal biomass with diatom-related lipids was characteristic in the upwelling zone, whereas haptophyte lipids were proportionally most abundant in the nutrient-poor settings of the centre of the South Pacific Gyre and on its easter edge. Dinoflagellate–sterols were minor contributors in all of the studied area and cyanobacteria-hydrocarbons were at maximum in the high nutrient low chlorophyll regime of the subequatorial waters at near the Marquesas archipelago. The taxonomic and spatial variability of the relationships between carbon photosynthetic fractionation and environmental conditions for four specific algal taxa (diatoms, haptophytes, dinoflagellates and cyanobacteria) was also investigated. The carbon isotope fractionation factor (ep) of the diatom marker varied over a range of 16‰ along the different trophic systems. In contrast, ep of dinoflagellate, cyanobacteria and alkenone markers varied only by 7–10‰. The low fractionation factors and small variations between the different phytoplankton markers measured in the upwelling area likely reveals uniformly high specific growth rates within the four phytoplankton taxa, and/or that transport of inorganic carbon into phytoplankton cells may not only occur by diffusion but by other carbon concentrating mechanisms (CCM). In contrast, in the oligotrophic zone, i.e. gyre and eastgyre, relatively high ep values, especially for the diatom marker, indicate diffusive CO2 uptake by the eukaryotic phytoplankton. At these nutrient-poor sites, the lowest ep values for haptophytes, dinoflagellates and cyanobacteria infer higher growth rates compared to diatoms

    La difusión de la prensa diaria en los Países Catalanes entre 1976 y 1996

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    Esta investigación analiza la evolución de la difusión de la prensa diaria en relación a la vertebración política de los territorios de Cataluña, Islas Baleares y País Valenciano con el conjunto del estado, desde el principio de la transición a la democracia en 1976 hasta 1996. Las principales conclusiones apuntan a un incremento de la vertebración estatal de estos territorios, especialmente en cuanto a su dependencia informativa provocada por el incremento muy significativo de la prensa central de penetración en cuanto a ventas totales, tasas de difusión y ocupación del mercado. El estado de las Autonomías se revela, pues, no como un factor de mayor autonomía informativa territorial, sino de integración y homogeneizació

    Mecanismes adrenèrgics en la fisiopatología del tremolor essencial

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    L'expressió tremolor essencial o tremolor essencial benigne s'empra per descriure una síndrome neurològica caracteritzada per la presència gairebé exclusiva d'un tremolor posicional predominant a les extremitats superiors..

    Vestibular role of KCNQ4 and KCNQ5 K+ channels revealed by mouse models

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    The function of sensory hair cells of the cochlea and vestibular organs depends on an influx of K+ through apical mechanosensitive ion channels and its subsequent removal over their basolateral membrane. The KCNQ4 (Kv7.4) K+ channel, which is mutated in DFNA2 human hearing loss, is expressed in the basal membrane of cochlear outer hair cells (OHCs) where it may mediate K+ efflux. Like the related K+ channel KCNQ5 (Kv7.5), KCNQ4 is also found at calyx terminals ensheathing type I vestibular hair cells where it may be localized pre- or postsynaptically. Making use of Kcnq4-/- mice lacking KCNQ4, as well as Kcnq4dn/dn and Kcnq5dn/dn mice expressing dominant negative channel mutants, we now show unambiguously that in adult mice both channels reside in postsynaptic calyx-forming neurons, but cannot be detected in the innervated hair cells. Accordingly whole-cell currents of vestibular hair cells did not differ between genotypes. Neither Kcnq4-/-, Kcnq5dn/dn nor Kcnq4-/-/Kcnq5dn/dn double mutant mice displayed circling behavior found with severe vestibular impairment. However, a milder form of vestibular dysfunction was apparent from altered vestibulo-ocular reflexes in Kcnq4-/-/Kcnq5dn/dn and Kcnq4-/- mice. The larger impact of KCNQ4 may result from its preferential expression in central zones of maculae and cristae, which are innervated by phasic neurons that are more sensitive than the tonic neurons predominantly present in the surrounding peripheral zones where KCNQ5 is found. The impact of postsynaptic KCNQ4 on vestibular function may be related to K+ removal and modulation of synaptic transmission.Fil: Spitzmaul, Guillermo Federico. Leibniz Institut Fur Molekulare Pharmakologie; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Investigaciones Bioquímicas Bahía Blanca (i); ArgentinaFil: Tolosa, Leonardo. Netherlands Institute For Neuroscience; Países BajosFil: Winkelman, Beerend H. J.. Netherlands Institute For Neuroscience; Países BajosFil: Heidenreich, Matthias. Leibniz_Institut Fur Molekulare Pharmakologie (Fmp) ; AlemaniaFil: Frens, Maartens. Department Of Neurosciences, Erasmus; Países BajosFil: Chabbert, Christian. Institut Des Neurosciences De Montpellier; FranciaFil: de Zeeuw, Chris I.. Netherlands Institute For Neuroscience; Países BajosFil: Jentsch, Thomas J.. Charité-Universitätsmedizin. Cluster of Excellence NeuroCure; Alemani
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