946 resultados para poetry of XXth century


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En el marco de la crisis vitivinícola de principios del siglo XX, se generó, entre los agentes implicados en esa actividad, una discusión sobre sus causas y posibles soluciones. Uno de los cambios propiciados fue la renovación de la legislación que regulaba la agroindustria. Este artículo analiza la génesis de la nueva ley de vinos, sancionada en 1904, con el nº 4363, que reguló la actividad hasta fines de la década de 1930 y constituyó un avance en la definición de vino genuino y otorgó herramientas más eficaces al Estado para reprimir la falsificación del vino. Sin embargo, reforzó el modelo de producción de vino en masa y dejó "espacios" de control vacíos que fueron denunciados por otros sectores relacionados con la agroindustria.

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La aparición de libros en español tales como El siglo XX de Eric J. Hobsbawm y la reedición de La crisis del Mundo Burgués de José Luis Romero, nos puso nuevamente en contacto con dos textos que poseen una sintonía notable. En el presente artículo se pretende ver cuales son los mundos descriptos por estos prestigiosos historiadores que son los mismos y distintos a la vez, en donde la erudición y la vivencia se convierten en dos instrumentos claves a la hora de observar sus interrogantes y respuestas sobre el pasado reciente.

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El pasado cercano, traumático, doloroso y abierto de los años 70-80, signados por la violencia política y el terrorismo de Estado, se encuentra en la agenda de la transmisión escolar. Como contenido de historia y ciencias sociales y de diversos actos de conmemoración, esta historia reciente interpela a las instituciones escolares y a los profesores. ¿Cómo se construyen las prácticas docentes en torno a esta historia reciente? ¿Qué lecturas y traducciones realizan los profesores de las prescripciones oficiales? ¿Qué lugar ocupa la historia reciente en la enseñanza de la historia argentina del siglo XX? ¿Cómo se materializan las conmemoraciones y clases alusivas acerca del tema? Estas preguntas han guiado nuestra indagación y nuestro diálogo con profesores de Ciudad y Provincia de Buenos Aires (que ejercen en secundaria, EGB3 o Polimodal) A partir de la voz de estos protagonistas, el trabajo pretende reconstruir la trama que participa en la transmisión de la historia reciente; un entramado cruzado, entre otros elementos, por la propia historia de la enseñanza de la historia, las tradiciones escolares y las políticas institucionales.

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El cartesianismo ha impregnado el pensamiento filosófico y científico occidental durante siglos, pero desde las últimas décadas del siglo XX han aparecido movimientos contestatarios significativos. Las tesis cartesianas más importantes cuestionadas han sido: a) el dualismo metafísico mente-cuerpo, que supone además la adopción sistemática de otros dualismos, b) el individualismo, c) el internalismo, que caracteriza la mente por sus relaciones internas y d) la identificación de la mente con la conciencia. Estas tesis no solo fueron de importancia para la historia del pensamiento filosófico y científico, sino que acarrearon consecuencias concretas en ámbitos como la educación y la práctica científica. Presentaremos algunos de los cambios conceptuales que se han pruducido, opuestos al cartesianismo. Uno de ellos es la emergencia de categorías como las de mente corporizada, mente situada y extendida, y sus consecuencias en los distintos contextos, que se oponen especialmente al internalismo y al individualismo. La mente no es concebida como lo que está "dentro de la cabeza", sino que se la concibe de un modo que incluye elementos del entorno, sea este el medio natural, social y tecnológico. Otro caso significativo es el reconocimiento de estructuras mentales no conscientes, opuestas a la concepción que identifica mente con conciencia

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El objetivo de este trabajo es mostrar las posibilidades que ofrece la documentación conservada en el Archivo Histórico del Agua para aproximarse a la cuestión de la creciente implicación del Estado mexicano en el proceso de modernización agraria, a través de la política de fomento a la irrigación, durante la primera parte del siglo XX. Para alcanzar esta meta partimos de la caracterización del modelo agroexportador implementado en México entre 1877 y 1930. Después sintetizamos la evolución del sector agropecuario en el estado de Sinaloa durante ese mismo periodo. Seguidamente, se enfatizan las expectativas iniciales que tuvo la oligarquía sobre la gran irrigación en Sinaloa a partir del estudio, fundamentalmente macroeconómico, de las tres empresas que suscribieron un contrato de subvención con el gobierno federal a fines del Porfiriato. Y, por último, a partir del seguimiento de estos mismos casos, se hacen claros los motivos que nos permiten entender la progresiva pérdida de legitimidad, tras el período revolucionario de 1910, de ese modelo modernizador del agro "desde arriba" con apoyo público hasta su quiebra final.

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En este trabajo se presenta un status quaestionis de las principales tendencias críticas del siglo XX sobre la "Eneida ovidiana" y se proponen cuatro parámetros metodológicos para abordar la secuencia: en primer lugar, considerar las razones para la inclusión de una Odisea en la "Eneida ovidiana", en el marco de las discusiones "sobre" género e influencias de la década del 90; en segundo lugar, precisar las relaciones de la secuencia con el final romano de la obra y las posibilidades de que, aun sin un augusteísmo político, haya una afirmación de Roma; en tercer lugar, otorgarle a la idea de la apoteosis y a la apoteosis de Eneas un papel destacado en la secuencia y en el plan de la obra; por último, aportar algo a la discusión sobre la concepción de hombre en las Metamorfosis y sus diferencias y complemento respecto de Virgilio

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Geographic information systems allow the extraction and quantitative analysis of information from historical maps. The aims of this research were to examine the completeness of information represented on the 1881 Palestine Exploration Fund (PEF) map, to quantitatively reconstruct the landscape of nineteenth century Palestine and to explore whether spatial patterns in land cover/land use can be partially explained statistically by physical and human factors. Using historical aerial photos, we concluded that most of the major past landscape features were indeed shown on the PEF map, with an average overall correspondence of 53%. Forests and Mediterranean maquis were more abundant at distances greater than 2 km from towns and villages. Specific land cover/land-use types were associated with certain soil types, topographic regions and rainfall thresholds. In conclusion, the 1881 PEF map can serve as a reliable reference for understanding the land cover/land-use patterns of nineteenth century Palestine.

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Instrumental monitoring of the climate at high northern latitudes has documented the ongoing warming of the last few decades. Climate modelling has also demonstrated that the global warming signal will be amplified in the polar region. Such temperature increases would have important implications on the ecosystem and biota of the Barents Sea. This study therefore aims to reconstruct the climatic changes of the Barents Sea based on benthic foraminifera over approximately the last 1400 years at the decadal to sub-decadal scale. Oxygen and carbon isotope analysis and benthic foraminiferal species counts indicate an overall warming trend of approximately 2.6°C through the 1400-year record. In addition, the well-documented cooling period equating to the 'Little Ice Age' is evident between c. 1650 and 1850. Most notably, a series of highly fluctuating temperatures are observed over the last century. An increase of 1.5°C is shown across this period. Thus for the first time we are able to demonstrate that the recent Arctic warming is also reflected in the oceanic micro-fauna.

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The world's oceans are warming and becoming more acidic. Both stressors, singly or in combination, impact marine species, and ensuing effects might be particularly serious for early life stages. To date most studies have focused on ocean acidification (OA) effects in fully marine environments, while little attention has been devoted to more variable coastal ecosystems, such as the Western Baltic Sea. Since natural spatial and temporal variability of environmental conditions such as salinity, temperature or pCO2 impose more complex stresses upon organisms inhabiting these habitats, species can be expected to be more tolerant to OA (or warming) than fully marine taxa. We present data on the variability of salinity, temperature and pH within the Kiel Fjord and on the responses of the barnacle Amphibalanus improvisus from this habitat to simulated warming and OA during its early development. Nauplii and cyprids were exposed to different temperature (12, 20 and 27°C) and pCO2 (nominally 400, 1250 and 3250 µatm) treatments for 8 and 4 weeks, respectively. Survival, larval duration and settlement success were monitored. Warming affected larval responses more strongly than OA. Increased temperatures favored survival and development of nauplii but decreased survival of cyprids. OA had no effect upon survival of nauplii but enhanced their development at low (12°C) and high (27°C) temperatures. In contrast, at the intermediate temperature (20°C), nauplii were not affected even by 3250 µatm pCO2. None of the treatments significantly affected settlement success of cyprids. These experiments show a remarkable tolerance of A. improvisus larvae to 1250 µatm pCO2, the level of OA predicted for the end of the century.

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Carbon dioxide concentrations in the surface ocean are increasing owing to rising CO2 concentrations in the atmosphere. Higher CO2 levels are predicted to affect essential physiological processes of many aquatic organisms, leading to widespread impacts on marine diversity and ecosystem function, especially when combined with the effects of global warming. Yet the ability for marine species to adjust to increasing CO2 levels over many generations is an unresolved issue. Here we show that ocean conditions projected for the end of the century (approximately 1,000 µatm CO2 and a temperature rise of 1.5-3.0 °C) cause an increase in metabolic rate and decreases in length, weight, condition and survival of juvenile fish. However, these effects are absent or reversed when parents also experience high CO2 concentrations. Our results show that non-genetic parental effects can dramatically alter the response of marine organisms to increasing CO2 and demonstrate that some species have more capacity to acclimate to ocean acidification than previously thought.

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We studied the interactive effects of pCO2 and growth light on the coastal marine diatom Thalassiosira pseudonana CCMP 1335 growing under ambient and expected end-of-the-century pCO2 (750 ppmv), and a range of growth light from 30 to 380 µmol photons/m**2/s. Elevated pCO2 significantly stimulated the growth of T. pseudonana under sub-saturating growth light, but not under saturating to super-saturating growth light. Under ambient pCO2 susceptibility to photoinactivation of photosystem II (sigma i) increased with increasing growth rate, but cells growing under elevated pCO2 showed no dependence between growth rate and sigma i, so under high growth light cells under elevated pCO2 were less susceptible to photoinactivation of photosystem II, and thus incurred a lower running cost to maintain photosystem II function. Growth light altered the contents of RbcL (RUBISCO) and PsaC (PSI) protein subunits, and the ratios among the subunits, but there were only limited effects on these and other protein pools between cells grown under ambient and elevated pCO2.

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The effects of ocean acidification and increased temperature on physiology of six strains of the polar diatom Fragilariopsis cylindrus from Greenland were investigated. Experiments were performed under manipulated pH levels (8.0, 7.7, 7.4, and 7.1) and different temperatures (1, 5, and 8 °C) to simulate changes from present to plausible future levels. Each of the 12 scenarios was run for 7 days, and a significant interaction between temperature and pH on growth was detected. By combining increased temperature and acidification, the two factors counterbalanced each other, and therefore no effect on the growth rates was found. However, the growth rates increased with elevated temperatures by 20-50% depending on the strain. In addition, a general negative effect of increasing acidification on growth was observed. At pH 7.7 and 7.4, the growth response varied considerably among strains. However, a more uniform response was detected at pH 7.1 with most of the strains exhibiting reduced growth rates by 20-37% compared to pH 8.0. It should be emphasized that a significant interaction between temperature and pH was found, meaning that the combination of the two parameters affected growth differently than when considering one at a time. Based on these results, we anticipate that the polar diatom F. cylindrus will be unaffected by changes in temperature and pH within the range expected by the end of the century. In each simulated scenario, the variation in growth rates among the strains was larger than the variation observed due to the whole range of changes in either pH or temperature. Climate change may therefore not affect the species as such, but may lead to changes in the population structure of the species, with the strains exhibiting high phenotypic plasticity, in terms of temperature and pH tolerance towards future conditions, dominating the population.

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The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.

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Ocean acidification studies in the past decade have greatly improved our knowledge of how calcifying organisms respond to increased surface ocean CO2 levels. It has become evident that, for many organisms, nutrient availability is an important factor that influences their physiological responses and competitive interactions with other species. Therefore, we tested how simulated ocean acidification and eutrophication (nitrate and phosphate enrichment) interact to affect the physiology and ecology of a calcifying chlorophyte macroalga (Halimeda opuntia (L.) J.V. Lamouroux) and its common noncalcifying epiphyte (Dictyota sp.) in a 4-week fully crossed multifactorial experiment. Inorganic nutrient enrichment (+NP) had a strong influence on all responses measured with the exception of net calcification. Elevated CO2 alone significantly decreased electron transport rates of the photosynthetic apparatus and resulted in phosphorus limitation in both species, but had no effect on oxygen production or respiration. The combination of CO2 and +NP significantly increased electron transport rates in both species. While +NP alone stimulated H. opuntia growth rates, Dictyota growth was significantly stimulated by nutrient enrichment only at elevated CO2, which led to the highest biomass ratios of Dictyota to Halimeda. Our results suggest that inorganic nutrient enrichment alone stimulates several aspects of H. opuntia physiology, but nutrient enrichment at a CO2 concentration predicted for the end of the century benefits Dictyota sp. and hinders its calcifying basibiont H. opuntia.

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Heavy metals pollution in marine environments has caused great damage to marine biological and ecological systems. Heavy metals accumulate in marine creatures, after which they are delivered to higher trophic levels of marine organisms through the marine food chain, which causes serious harm to marine biological systems and human health. Additionally, excess carbon dioxide in the atmosphere has caused ocean acidification. Indeed, about one third of the CO2 released into the atmosphere by anthropogenic activities since the beginning of the industrial revolution has been absorbed by the world's oceans, which play a key role in moderating climate change. Modeling has shown that, if current trends in CO2 emissions continue, the average pH of the ocean will reach 7.8 by the end of this century, corresponding to 0.5 units below the pre-industrial level, or a three-fold increase in H+ concentration. The ocean pH has not been at this level for several millions of years. Additionally, these changes are occurring at speeds 100 times greater than ever previously observed. As a result, several marine species, communities and ecosystems might not have time to acclimate or adapt to these fast changes in ocean chemistry. In addition, decreasing ocean pH has the potential to seriously affect the growth, development and reproduction reproductive processes of marine organisms, as well as threaten normal development of the marine ecosystem. Copepods are an important part of the meiofauna that play an important role in the marine ecosystem. Pollution of the marine environment can influence their growth and development, as well as the ecological processes they are involved in. Accordingly, there is important scientific value to investigation of the response of copepods to ocean acidification and heavy metals pollution. In the present study, we evaluated the effects of simulated future ocean acidification and the toxicological interaction between ocean acidity and heavy metals of Cu and Cd on T. japonicus. To accomplish this, harpacticoids were exposed to Cu and Cd concentration gradient seawater that had been equilibrated with CO2 and air to reach pH 8.0, 7.7, 7.3 and 6.5 for 96 h. Survival was not significantly suppressed under single sea water acidification, and the final survival rates were greater than 93% in both the experimental groups and the controls. The toxicity of Cu to T. japonicus was significantly affected by sea water acidification, with the 96h LC50 decreasing by nearly threefold from 1.98 to 0.64 mg/L with decreasing pH. The 96 h LC50 of Cd decreased with decreasing pH, but there was no significant difference in mortality among pH treatments. The results of the present study demonstrated that the predicted future ocean acidification has the potential to negatively affect survival of T. japonicus by exacerbating the toxicity of Cu. The calculated safe concentrations of Cu were 11.9 (pH 7.7) and 10.5 (pH 7.3) µg/L, which were below the class I value and very close to the class II level of the China National Quality Standard for Sea Water. Overall, these results indicate that the Chinese coastal sea will face a