977 resultados para HOBSBAWM, ERIC J., 1917-2012


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The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a large-scale mesocosm experiment was performed off Tvärminne Research Station, Finland in summer 2012. During the second half of the experiment, dimethylsulphide (DMS) concentrations in the highest fCO2 mesocosms (1075-1333 µatm) were 34 % lower than at ambient CO2 (350 µatm). However the net production (as measured by concentration change) of seven halocarbons analysed was not significantly affected by even the highest CO2 levels after 5 weeks exposure. Methyl iodide (CH3I) and diiodomethane (CH2I2) showed 15 % and 57 % increases in mean mesocosm concentration (3.8 ± 0.6 pmol L-1 increasing to 4.3 ± 0.4 pmol L-1 and 87.4 ± 14.9 pmol L-1 increasing to 134.4 ± 24.1 pmol L-1 respectively) during Phase II of the experiment, which were unrelated to CO2 and corresponded to 30 % lower Chl-? concentrations compared to Phase I. No other iodocarbons increased or showed a peak, with mean chloroiodomethane (CH2ClI) concentrations measured at 5.3 (± 0.9) pmol L-1 and iodoethane (C2H5I) at 0.5 (± 0.1) pmol L-1. Of the concentrations of bromoform (CHBr3; mean 88.1 ± 13.2 pmol L-1), dibromomethane (CH2Br2; mean 5.3 ± 0.8 pmol L-1) and dibromochloromethane (CHBr2Cl, mean 3.0 ± 0.5 pmol L-1), only CH2Br2 showed a decrease of 17 % between Phases I and II, with CHBr3 and CHBr2Cl showing similar mean concentrations in both Phases. Outside the mesocosms, an upwelling event was responsible for bringing colder, high CO2, low pH water to the surface starting on day t16 of the experiment; this variable CO2 system with frequent upwelling events implies the community of the Baltic Sea is acclimated to regular significant declines in pH caused by up to 800 µatm fCO2. After this upwelling, DMS concentrations declined, but halocarbon concentrations remained similar or increased compared to measurements prior to the change in conditions. Based on our findings, with future acidification of Baltic Sea waters, biogenic halocarbon emissions are likely to remain at similar values to today, however emissions of biogenic sulphur could significantly decrease from this region.

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Anthropogenic carbon dioxide (CO2) emissions are reducing the pH in the world's oceans. The plankton community is a key component driving biogeochemical fluxes, and the effect of increased CO2 on plankton is critical for understanding the ramifications of ocean acidification on global carbon fluxes. We determined the plankton community composition and measured primary production, respiration rates and carbon export (defined here as carbon sinking out of a shallow, coastal area) during an ocean acidification experiment. Mesocosms (~ 55 m3) were set up in the Baltic Sea with a gradient of CO2 levels initially ranging from ambient (~ 240 µatm), used as control, to high CO2 (up to ~ 1330 µatm). The phytoplankton community was dominated by dinoflagellates, diatoms, cyanobacteria and chlorophytes, and the zooplankton community by protozoans, heterotrophic dinoflagellates and cladocerans. The plankton community composition was relatively homogenous between treatments. Community respiration rates were lower at high CO2 levels. The carbon-normalized respiration was approximately 40 % lower in the high CO2 environment compared with the controls during the latter phase of the experiment. We did not, however, detect any effect of increased CO2 on primary production. This could be due to measurement uncertainty, as the measured total particular carbon (TPC) and combined results presented in this special issue suggest that the reduced respiration rate translated into higher net carbon fixation. The percent carbon derived from microscopy counts (both phyto- and zooplankton), of the measured total particular carbon (TPC) decreased from ~ 26 % at t0 to ~ 8 % at t31, probably driven by a shift towards smaller plankton (< 4 µm) not enumerated by microscopy. Our results suggest that reduced respiration lead to increased net carbon fixation at high CO2. However, the increased primary production did not translate into increased carbon export, and did consequently not work as a negative feedback mechanism for increasing atmospheric CO2 concentration.

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Com este estudo pretendi perceber as estratégias e dificuldades que persistem em alunos que supostamente terão sido alvo de um trabalho com números racionais nos primeiros anos de escolaridade, mais concretamente perceber a noção de partilha equitativa, bem como de comparação de frações dos referidos alunos. Decorre do referido objetivo as seguintes questões de investigação: (1) Que estratégias e dificuldades apresentam os alunos na resolução de situações de partilha equitativa? (2) Que estratégias e dificuldades apresentam os alunos na comparação de números racionais? Para atingir o objetivo pretendido recorri a uma investigação de cariz interpretativo, abordagem essencialmente qualitativa e pesquisa documental, pelo que analisei as provas de Matemática realizadas por 1330 alunos de 21 agrupamentos do Distrito de Leiria, no âmbito do concurso “DESAFIOS 2012”, mais concretamente as respostas dadas a uma tarefa relativa aos números racionais. De salientar que os alunos que participaram no concurso “DESAFIOS 2012”, frequentaram o 1.º ciclo do ensino básico, já no âmbito da entrada em vigor do Programade Matemática do Ensino Básico - PMEB (ME, 2007). Os resultados levam a concluir que uma das estratégias mais usada é o recurso à modelação da tarefa para a partilha equitativa das sandes, bem como formas intuitivas de pensamento para a comparação de frações. As dificuldades prendem-se essencialmente com a modelação da tarefa e identificação das quantidades envolvidas, bem como o recurso ao pensamento diferencial para a comparação das frações.

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In the context of demands by the European feminist movement at the beginning of the 20th century, in Spain women’s sport flagged up aspirations to what were considered to be male practices. The first experiences of women in football stand out because of their use of the media to appear as a symbol of social transformation to modernity in the 20th century. It was not in vain that women’s football highlighted the demands of the feminist movements, although it did come up against male disapproval from an opposing group. The research sets out from a bibliographical and media review of specialist press and sports news of the time. Other current studies have also been considered in order to place it in a social and historical focus on sport. This has enabled us to highlight that football in Spain was established as an unequivocal space for (re) producing male hegemony where women were relegated to the representation of a symbolic ritual in a scenario of accessory and condescension.

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La consolidación del fútbol en España se produjo a partir de los años veinte del siglo pasado. Entre 1920 a 1936 el fútbol adquirió todos los rasgos personales que hoy le caracterizan. En esta época surgió una literatura técnica y periodística especializada que se configuró como uno de los pilares más importantes para el desarrollo técnico deportivo y del espectáculo de masas. En torno a esta cuestión, el presente artículo busca un doble objetivo: recopilar la literatura técnica y periodística especializada publicada durante el período de 1920 a 1936, y reconocer el alcance social, técnico e ideológico de esta literatura futbolística en el proceso de configuración del fútbol en España. Para abordar este propósito hemos utilizado una metodología heurística y de análisis documental de las fuentes originales. Apreciamos que a través de estas obras podemos conocer mejor el contexto del espacio socio-deportivo del fútbol en España y, también, despertar nuevas líneas potenciales de investigación.

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En este artículo se estudia una obra atribuida a Sófocles titulada Κρῆτες (Los cretenses), una tragedia sólo conocida por dos dudosos testimonios de Hesiquio y Ateneo de Náucratis. A finales del siglo xviii una nueva lectura de ambos los adscribía a otra tragedia, con lo que se negaba la existencia de Κρῆτες. A pesar de esto, este título se sigue manteniendo en las ediciones de la obra sofoclea, ahora relacionado con nuevos hallazgos de fragmentos papiráceos del autor. Nuestro objetivo es el de analizar los testimonios en profundidad para concluir si la obra pudo o no haberse escrito.

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adesp. fr. 700 Kn.-Sn. podría proceder de Andrómeda de Eurípides y no de una Níobe. Los siguientes elementos de los frs. (a) y (b) pueden responder a lo que se conoce de la tragedia de Eurípides: (a) la semejanza con una estatua; (b) la novia de Hades; (c) el silencio del personaje; (d) la colaboración con las Moiras; (e) el contraste entre la fortuna regia y la desgracia y el sufrimiento de los padres. No es, por tanto, necesario modificar el texto recibido para eliminar μάγους πάγας y la referencia a las trampas mágicas en el v. 5, que cuadra bien con Medusa y Perseo.

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Recent evidence suggests that - in addition to 17p deletion - TP53 mutation is an independent prognostic factor in chronic lymphocytic leukemia (CLL). Data from retrospective analyses and prospective clinical trials show that ∼5% of untreated CLL patients with treatment indication have a TP53 mutation in the absence of 17p deletion. These patients have a poor response and reduced progression-free survival and overall survival with standard treatment approaches. These data suggest that TP53 mutation testing warrants integration into current diagnostic work up of patients with CLL. There are a number of assays to detect TP53 mutations, which have respective advantages and shortcomings. Direct Sanger sequencing of exons 4-9 can be recommended as a suitable test to identify TP53 mutations for centers with limited experience with alternative screening methods. Recommendations are provided on standard operating procedures, quality control, reporting and interpretation. Patients with treatment indications should be investigated for TP53 mutations in addition to the work-up recommended by the International workshop on CLL guidelines. Patients with TP53 mutation may be considered for allogeneic stem cell transplantation in first remission. Alemtuzumab-based regimens can yield a substantial proportion of complete responses, although of short duration. Ideally, patients should be treated within clinical trials exploring new therapeutic agents.

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En vista de las inequidades entre mujeres y hombres como las implicaciones que éstas posan sobre la seguridad alimentaria y el desarrollo agro-rural, la Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) ha incursionado en procesos de comunicación para el desarrollo con un proyecto que innovador, integra un enfoque de género.

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Introducción El golpe de Estado de 1917, el periódico “La Información” en su primera pagina destacaba con grandes titulares los sucesos políticos ocurridos el día anterior, esto era el 27 de enero, fecha de importantes acontecimientos en nuestra historia patria