973 resultados para 12930-040
Resumo:
Se estudiará, desde una perspectiva interdisciplinar (Semiótica, Análisis del Discurso, Comunicación), el trabajo massmediático de representación e interpretación de los países limítrofes en los medios gráficos, entendidos como dispositivos de mediación de la experiencia y el sentido de la comunidad, la identidad y la memoria colectiva. Se analizarán los procesos de semiotización mediática de las configuraciones cronotópicas locales, nacionales, regionales, en los que se haga referencia a cualquier aspecto, dimensión, nivel, esfera social, relacionados con los países fronterizos, en el marco de los procesos de integración del Cono Sur, con vistas a los procesos de globalización y mundialización.
Resumo:
Actividades desarrolladas durante el período: se trata de las actividades efectivamente realizadas durante el período de referencia. Consulta bibliográfica; Recopilación de documentos; Selección de unidades de análisis; Desarrollo de entrevistas; Análisis de datos; Producción de documentos.
Resumo:
Among bivalves, scallops are exceptional due to their capacity to escape from predators by swimming which is provided by rapid and strong claps that are produced by the phasic muscle interspersed with tonic muscle contractions. Based on the concept of oxygen and capacity-limited thermal tolerance, the following hypothesis was tested: ocean warming and acidification (OWA) would induce disturbances in aerobic metabolic scope and extracellular acid-case status and impair swimming performance in temperate scallops. Following long-term incubation under near-future OWA scenarios [20 vs. 10 °C (control) and 0.112 kPa CO2 (hypercapnia) vs. 0.040 kPa CO2 (normocapnic control)], the clapping performance and metabolic rates (MR) were measured in resting (RMR) and fatigued (maximum MR) king scallops, Pecten maximus, from Roscoff, France. Exposure to OA, either alone or combined with warming, left MR and swimming parameters such as the total number of claps and clapping forces virtually unchanged. Only the duration of the escape response was affected by OA which caused earlier exhaustion in hyper- than in normocapnic scallops at 10 °C. While maximum MR was unaffected, warm exposure increased RMR in both normocapnic and hypercapnic P. maximus resulting in similar Q 10 values of ~2.2. The increased costs of maintenance and the observation of strongly reduced haemolymph PO2 levels indicate that at 20 °C scallops have reached the upper thermal pejus range with unbalanced capacities for aerobic energy metabolism. As a consequence, warming to 20 °C decreased mean phasic force during escape performance until fatigue. The observed prolonged recovery time in warm incubated scallops might be a consequence of elevated metabolic costs at reduced oxygen availability in the warmth.
Resumo:
Middle Eocene to Late Oligocene sediments from near the crest (Site 689B, water depth 2080 m) and flank (water depth 2914 m) of the Maud Rise (62°S) have been investigated by coarse fraction analysis and have revealed the following: (1) The middle Eocene (50-40 Ma) was a period of pure carbonate sedimentation, with good preservation of carbonate microfossils. No opal > 40 µm is present. (2) In the late Eocene (40-36.5 Ma) opal fossils (mainly radiolaria, and some diatoms > 40 µm) appeared for the first time. Three maxima in opal sedimentation (Eocene/Oligocene boundary, middle early Oligocene and early/late Oligocene boundary) are separated by increases in carbonate sedimentation. The dissolution of carbonate fossils is strong in the opal-rich layers. Opal sedimentation is attributed to cooling and probably more vigorous atmospheric circulation and increased upwelling. (3) Carbonate dissolution increased with water depth in the Oligocene, whereas in the middle Eocene excellent carbonate preservation in the deeper Site 690B and stronger dissolution in the shallower Site 689B is attributed to different bottom-water characteristics. The middle Eocene bottom water probably was formed by strong evaporation at low latitudes, whereas by the earliest Oligocene formation of Antarctic Bottom Water (AABW) had set in. (4) Current influence, not on top but on the flank of the Maud Rise, could be recorded by means of larger grain sizes of benthonic and planktonic microfossils. (5) Ice-rafted debris was not found. Quartz and other minerals are very rare and not larger than 125 µm and may have been supplied by ice as well as by wind or by deep currents. Mica contents were up to 10 times higher in the middle Eocene on the flank compared to on the crest of the Maud Rise, indicating deep current supply.
Resumo:
One of the expected scientific results of Ocean Drilling Program Leg 167 was to reconstruct the Neogene history of biogenic calcium carbonate accumulation in the northeastern Pacific along the California margin (Lyle, Koizumi, Richter, et al., 1997). This aims to constrain inorganic carbon burial rates, deep-water hydrography in the North Pacific, and linkages between deep Atlantic and Pacific circulation and carbonate accumulation or dissolution patterns. Data are presented for four sites. Two of them are located in the California bight-East Cortez Basin (Site 1012: 32°16.970?N 118°23.024?W, 1773 m) and San Nicholas Basin (Site 1013: 32°48.040??, 118°53.992?W, 1564 m). The others are the dedicated Hole 1017E at Site 1017 (34°32.099?N, 121°6.430?W, 955 m) and Site 1019 in the Eel River Basin (41¢X40.972?N, 124°55.975?W, 977 m). Reconstruction of paleo-sea-surface temperatures (SST) by determining the alkenone unsaturation index of the extractable organic matter is an independent technique and helps to verify oxygen-isotope-based estimates. Results from the uppermost 600 cm of the dedicated Hole 1017E are expected to reveal the local temperature history of the last 30 k.y.