3,744 research outputs found

    Consumo e hipermodernidad: una revisión de la teoría de Gilles Lipovetsky

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    Gilles Lipovetsky has gradually become one of the most internationally acclaimed scholars in modern French sociology due to his sharp analyses on post-modern societies. In this paper we will develop a critical revision of his main lines of thought. Our goal is to reflect upon the limits of Lipovetsky’s approach to concepts such as post-modernity, hypermodernity and consumption

    Socialization of the elderly in outdoor health circuits

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    En los parques biosaludables, originalmente concebidos para la población madura y anciana, se encuentran usuarios de diferentes edades y con distintas formas de entender la actividad física. El presente trabajo intenta examinar las relaciones de las personas mayores con el resto de usuarios para determinar en qué medida dichos parques pueden cumplir alguna función social más allá del fomento de hábitos saludables. Para ello se ha llevado a cabo una serie de observaciones, participantes y no participantes, en tres parques de la ciudad de Granada, donde se ha visto que, si bien existe una proporción minoritaria pero importante de usuarios jóvenes (aproximadamente un tercio del total), estos tienden a evitar una interacción que parte de los usuarios de mayor edad buscan expresamente

    Fenómenos de retracción y comportamiento frente a la corrosión de materiales base cemento de bajo pH basados en OPC o CAC

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    Prior to using low-pH cementitious materials in underground repositories for high level waste, the characteristics determining their long-term durability must be analysed in depth. In this sense, different shrinkage tests have been made on mortar and concrete specimens using low-pH cement formulations based on ordinary portland cement (OPC) or calcium aluminate cement (CAC), with high mineral admixtures contents. They showed similar autogenous shrinkage than samples without mineral admixtures but higher drying shrinkage when materials based on OPC with high silica fume contents were considered. Besides, as the use of reinforced concrete could be required in underground repositories, the susceptibility of reinforcement to corrosion when using low-pH cementitious materials based on OPC was analyzed, considering carbon steel and galvanized steel. In the formers corrosion was detected due to the low pore solution pH but any problem was detected when galvanized reinforcement were used.Previo al empleo de materiales con cementos de bajo pH en almacenamientos geológicos profundos (AGP) de residuos radiactivos de alta actividad, características relacionadas con su durabilidad a largo plazo deben ser verificadas. Así, su estabilidad volumétrica se ha analizado en morteros y hormigones de bajo pH basados en OPC o CAC, con elevados contenidos de adiciones minerales. Estos presentaron retracciones autógenas similares a las medidas en materiales convencionales, pero retracciones por secado mayores en los basados en OPC y altos contenidos de humo de sílice. Dado que en zonas de los AGP podría emplearse hormigón armado, también se evaluó la susceptibilidad a la corrosión de aceros al carbono y aceros galvanizados en materiales de bajo pH basados en OPC. Se detectó un inicio temprano de corrosión en los primeros debido al bajo pH presente en el fluido de los poros de estos materiales, sin detectarse problemas al emplear aceros galvanizados

    El Coeficiente de Pulimento Acelerado y su relación con parámetros petrográficos (contraste de dureza y composición modal) y la microrrugosidad superficial de áridos naturales y artificiales

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    The goal of this work was first to establish the relationships between the PSV values and the microstructural and mineralogical features of the aggregates and surface micro-roughness, and then to establish the behavioural differences between natural and artificial aggregates. The results obtained indicate that the surface micro-roughness and the different PSV values of the natural aggregates are strongly governed by the existence of minerals with different degrees of hardness, together with the proportion of these minerals. In contrast, the different degree of porosity in artificial aggregates (a furnace slag) was seen to be responsible for its high surface micro-roughness and PSV values. Finally, the PSV and a petrographic parameter (Overall Hardness Contrast, ΔH) were seen to be related by an exponential curve (PSV=39.726ΔH0.057) with an extremely good fit, providing a good tool to estimate PSVs in natural and artificial aggregates from petrographic parameters.El objetivo de este trabajo es establecer, por un lado, las relaciones existentes del CPA con las características petrográficas de los áridos, así como su microrrugosidad superficial y, por otro, las diferencias de comportamiento entre áridos naturales y artificiales. Los resultados indican que en los áridos naturales la microrrugosidad superficial y el diferente valor del CPA están determinados, en gran medida, por las diferencias de dureza de sus minerales y también por la proporción en la que estos minerales se encuentran en las distintas litologías. Sin embargo, en los áridos artificiales (escorias de fundición) su elevada porosidad es la responsable de su marcada microrrugosidad superficial y su elevado valor del CPA. Finalmente, se relaciona el CPA con un parámetro petrográfico (Contraste de Dureza Global, ΔH) mediante una curva exponencial, cuyo excelente índice de regresión hace que sea factible estimar mediante el estudio petrográfico de un árido su valor del CPA (CPA=39,726ΔH0,057)

    Tree species effects on soil microbial community composition and greenhouse gases emissions in a Mediterranean ecotone forest

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    Resumen de una presentación realizada en: I Simposio sobre Interacciones Planta-Suelo (ICA-CSIC, Madrid, 25-26 Febrero 2016)Over recent decades in the Iberian Peninsula, altitudinal shifts from Pinus sylvestris L. to Quercus pyrenaica Willd species has been observed as a consequence of Global Change, meaning changes in temperature, precipitation, land use and forestry. The forest conversion from pine to oak can alter the litter quality and quantity provided to the soil and thereby the soil microbial community composition and functioning. Since soil microbiota plays an important role in organic matter decomposition, and this in turn is key in biogeochemical cycles and forest ecosystems productivity, the rate in which forests produce and consume greenhouse gases can be also affected by changes in forest composition. In other words, changes in litter decomposition will ultimately affect downstream carbon and nitrogen dynamics although this impact is uncertain. In order to predict changes in carbon and nitrogen stocks in Global Change scenarios, it is necessary to deepen the impact of vegetation changes on soil microbial communities, litter decomposition dynamics (priming effect) and the underlying interactions between these factors. To test this, we conducted a full-factorial transplant microcosms experiment mixing both fresh soils and litter from Pyrenean oak, Scots pine and mixed stands collected inside their transitional area in Central Spain. The microcosms consisted in soil cylinders inside Kilner jars used as chambers inside an incubator. In this experiment, we investigated how and to what extent the addition of litter with different quality (needles, oak leaves and mixed needlesleaves) to soil inoculums with contrasting soil microbiota impact on soil (i) CO2, NO, N2O and CH4 efflux rates, (ii) total organic carbon and nitrogen and (iii) dissolved organic carbon and nitrogen. Furthermore, we assessed if these responses were controlled by changes in the microbial community structure using the PLFA analyses prior and after the incubation period of 54 days.Peer reviewe

    INCIDENCIA DE CARDIOPATÍAS DURANTE EL EMBARAZO EN LA PROVINCIA DE VILLA CLARA / Incidence of heart disease during pregnancy in Villa Clara province

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    ResumenIntroducción y objetivos: Las enfermedades cardiovasculares constituyen la cuarta causa de muerte durante el período gravídico-puerperal, y un indicador de morbilidad y mortalidad para el producto de la concepción. El objetivo de esta investigación fue determinar el comportamiento de la cardiopatía en la embarazada, su atención médica y evolución durante y al final del embarazo. Método: Se realizó un estudio descriptivo, prospectivo, donde se analizaron 283 gestantes con diagnóstico de cardiopatía, atendidas en el Hospital Universitario Gineco-Obstétrico "Mariana Grajales" de Santa Clara, Villa Clara, en el período 2008-2010. La información se obtuvo mediante la revisión de las historias clínicas individuales, interrogatorio, examen físico completo, así como pruebas complementarias para establecer o confirmar el diagnóstico. Resultados: Se obtuvo una incidencia de 17,2 cardiopatías por cada mil gestantes y en el 59,7 % de ellas, la cardiopatía era adquirida; el prolapso valvular mitral fue la más frecuente (45 %). De las congénitas, el 36,8 % se trataba de una comunicación interauricular. Se utilizó antibioprofilaxis en el 96,8 % de las embarazadas y en el 96,1 % de ellas se mantuvo un seguimiento médico. El 92,6 % tenía clase funcional I y 4,6 % presentó complicación por su enfermedad. El 77,4 % parió entre las 37 y 42 semanas, y el 82,7 % tuvo parto eutócico. Conclusiones: Las gestantes cardiópatas fueron más frecuentes en edades entre 20 y 29 años, con predominio de las que no habían parido, captación entre las 13 y 24 semanas, y cardiopatías adquiridas. La atención médica que prevaleció fue la antibioprofilaxis y el seguimiento médico con evolución final del embarazo satisfactoria. / AbstractIntroduction and Objectives: Cardiovascular diseases are the fourth leading cause of death during the gravid-puerperal period, and an indicator of morbidity and mortality for the product of conception. The objective of this research was to determine the behavior of heart disease in pregnant women, its medical care and evolution during and after pregnancy. Method: A prospective descriptive study was performed, which analyzed 283 pregnant women diagnosed with heart disease, and treated at the Obstetrics and Gynecology University Hospital "Mariana Grajales" in Santa Clara, Villa Clara, in the period 2008-2010. Information was obtained through review of individual medical records, interview, complete physical examination and laboratory tests to establish or confirm the diagnosis. Results: A heart disease incidence of 17.2 per thousand pregnant women was obtained and in 59.7% of them, the heart disease was acquired, and the mitral valve prolapse was the most frequent (45%). Of the congenital diseases, 36.8% was an atrial septal defect. Antibiotic prophylaxis was used in 96.8% of pregnant women and in 96.1% of them a medical monitoring was kept. 92.6% had functional class I and 4.6% presented disease-related complications. 77.4% gave birth between 37 and 42 weeks, and 82.7% had vaginal delivery. Conclusions: Pregnant women with heart disease were more common in ages 20 to 29 years, predominantly in those who had not given birth, whose pregnancies had been detected between 13 and 24 weeks, and with acquired heart diseases. The prevailing medical care was antibiotic prophylaxis and medical monitoring with satisfactory final outcome of pregnancy

    Crystallization of para-Hydrogen: a quantum phase transition at finite temperature?

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    4 págs.; 3 figs.; Open Access funded by Creative Commons Atribution Licence 3.0; 7th Meeting of the Spanish Neutron Scattering Association (SETN)Recent neutron scattering measurements have revealed that para-Hydrogen prepared in its fundamental state solidifies in a crystal that do not show temperature response (temperature independent molecular displacement and first rotational level linewidth as well as negligible thermal expansion). Here, it is argued that such unique behaviour in the crystal phase can be understood if the crystallization is driven by pure quantum fluctuations.Work supported in part by grants MAT2007-65711-C04-01 and MAT2012-33633 from the Spanish Ministerio de Economía y Competitividad.Peer Reviewe

    Hierarchy of QM SUSYs on a Bounded Domain

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    We systematically formulate a hierarchy of isospectral Hamiltonians in one-dimensional supersymmetric quantum mechanics on an interval and on a circle, in which two successive Hamiltonians form N=2 supersymmetry. We find that boundary conditions compatible with supersymmetry are severely restricted. In the case of an interval, a hierarchy of, at most, three isospectral Hamiltonians is possible with unique boundary conditions, while in the case of a circle an infinite tower of isospectral Hamiltonians can be constructed with two-parameter family of boundary conditions.Comment: 15 pages, 3 figure
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