Arte y política : Las rarezas de la revista Hexágono '71 de Edgardo Antonio Vigo

Este trabajo presenta uno de los modos por los cuales el arte se encuentra con la política a través de la poética del artista plástico Edgardo Antonio Vigo, entre fines de lo '60 y mediados de los '70. Desde la vanguardia estética este artista trabajó con diversos materiales, generando una poética que apuntaba a provocar la participación del público, su asombro o desconcierto, así como formas expresivas que se alejaban de las Bellas Artes y sus cánones. Además, incorporó temas vinculados con la política, especialmente asociados a la radicalización, que tomaban elementos comunes a los discursos y prácticas culturales de la época, sin abandonar su posición vanguardista. El análisis de la revista Hexágono 71, permite pensar lo político del arte en tanto forma de desestructurar los modos de concebir la organización y jerarquías, sujetos y objetos del orden social, como su vinculación con la política, los acontecimientos y disputas del momento, aunque sin responder al modelo del artista comprometido

(Table 1) Bioclimatic subzones and soil characteristics along the Yamal Arctic Transect, northwestern Siberia

Sustainability of tundra vegetation under changing climate on the Yamal Peninsula, northwestern Siberia, home to the world's largest area of reindeer husbandry, is of crucial importance to the local native community. An integrated investigation is needed for better understanding of the effects of soils, climate change and grazing on tundra vegetation in the Yamal region. In this study we applied a nutrient-based plant community model - ArcVeg - to evaluate how two factors (soil organic nitrogen (SON) levels and grazing) interact to affect tundra responses to climate warming across a latitudinal climatic gradient on the Yamal Peninsula. Model simulations were driven by field-collected soil data and expected grazing patterns along the Yamal Arctic Transect (YAT), within bioclimate subzones C (high arctic), D (northern low arctic) and E (southern low arctic). Plant biomass and NPP (net primary productivity) were significantly increased with warmer bioclimate subzones, greater soil nutrient levels and temporal climate warming, while they declined with higher grazing frequency. Temporal climate warming of 2 °C caused an increase of 665 g/m**2 in total biomass at the high SON site in subzone E, but only 298 g/m**2 at the low SON site. When grazing frequency was also increased, total biomass increased by only 369 g/m**2 at the high SON site in contrast to 184 g/m**2 at the low SON site in subzone E. Our results suggest that high SON can support greater plant biomass and plant responses to climate warming, while low SON and grazing may limit plant response to climate change. In addition to the first order factors (SON, bioclimate subzones, grazing and temporal climate warming), interactions among these significantly affect plant biomass and productivity in the arctic tundra and should not be ignored in regional scale studies.

Persas de Esquilo : vv. 1-154

El teatro de Esquilo, luego de los análisis surgidos en la primera mitad del siglo XX bajo la óptica alemana, pareció pasar inadvertido a la mirada crítica posterior. Actualmente, de la mano de las nuevas corrientes que privilegiaron el estudio de la performance teatral, la obra del poeta se somete a análisis desde una visión renovadora que absorbe y trasciende el debate exclusivamente filológico. Entre las tragedias conservadas de la Antigüedad Clásica, Persas se erige no sólo como el primer testimonio completo del género, sino también como la única pieza que poseemos con tema histórico. Inscribiéndonos en el marco de las últimas tendencias críticas, a partir del análisis filológico-literario de la Párodos (vv. 1-154), en el presente trabajo nos proponemos ver de qué manera el poeta construye la imagen del bárbaro frente a la del griego, teniendo en cuenta que la pieza, que ofrece la mirada persa sobre la batalla de Salamina, fue concebida por un ateniense, para la audiencia ateniense. Historia y manifestación literaria convergen, así, en una tragedia que revela el pensamiento y la grandeza de su creador.

Stable oxygen isotope record of Globigerinoides ruber of ODP Site 133-820 off the Great Barriere Reef

Oxygen-isotope ratio measurements are presented for the planktonic species Globigerinoides ruber collected from shallow-water, upper-slope sediments from Holes 820A and 820B in 280 m of water, on the seaward edge of the Great Barrier Reef. Correlation of the Site 820 isotope curve with deep-sea reference curves of the Pacific Ocean (Core V28-238, Hole 677A, Hole 607A) permits the definition of isotope stages 1 to 19 in the top 145 m of Holes 820A and 820B. However, paleontological data indicate that stages 4 and 7 might be missing and that two hiatuses occur at a depth of 8.05 to 12.1 and 34.55 to 35.8 mbsf. Using deep-sea Hole 677A as a reference for ice-volume variations, we determine the difference in isotopic signature between it and Site 820. We propose that this difference is a regional signal representing a progressive 4°C increase in surface-water temperature at Site 820. The proposed temperature change was initiated at about 400 k.y. and corresponds to a change from high-to-low frequency variations in Pleistocene isotope signals. We postulate that these changes may have catalyzed the growth of the Great Barrier Reef. The shift also coincides with changes in seismic character and some physical and chemical sediment characteristics.

Age determination, sedimentological, biogeochemical, and plant macrofossils analyses of outcrop PG2038-1

Thermokarst lakes are a widespread feature of the Arctic tundra, in which highly dynamic processes are closely connected with current and past climate changes. We investigated late Quaternary sediment dynamics, basin and shoreline evolution, and environmental interrelations of Lake El'gene-Kyuele in the NE Siberian Arctic (latitude 71°17'N, longitude 125°34'E). The water-body displays thaw-lake characteristics cutting into both Pleistocene Ice Complex and Holocene alas sediments. Our methods are based on grain size distribution, mineralogical composition, TOC/N ratio, stable carbon isotopes and the analysis of plant macrofossils from a 3.5-m sediment profile at the modern eastern lake shore. Our results show two main sources for sediments in the lake basin: terrigenous diamicton supplied from thermokarst slopes and the lake shore, and lacustrine detritus that has mainly settled in the deep lake basin. The lake and its adjacent thermokarst basin rapidly expanded during the early Holocene. This climatically warmer than today period was characterized by forest or forest tundra vegetation composed of larches, birch trees and shrubs. Woodlands of both the HTM and the Late Pleistocene were affected by fire, which potentially triggered the initiation of thermokarst processes resulting later in lake formation and expansion. The maximum lake depth at the study site and the lowest limnic bioproductivity occurred during the longest time interval of ~7 ka starting in the Holocene Thermal Maximum and lasting throughout the progressively cooler Neoglacial, whereas partial drainage and an extensive shift of the lake shoreline occurred ~0.9 cal. ka BP. Correspondingly, this study discusses different climatic and environmental drivers for the dynamics of a thermokarst basin.