Relaciones y pluralismo

En la segunda mitad de este trabajo presentamos un "Breve discurso acerca del Pluralismo." Su propósito consiste en resaltar las categorías de relación y multiplicidad frente a los conceptos opuestos de término y unidad. Dicho énfasis sencillamente reconoce algo que ha venido sucediendo en diversas disciplinas durante algún tiempo, un intento que hoy es especialmente urgente, dado que hay muchos desarrollos notables en las ciencias que no podemos comprender adecuadamente -o incluso aceptar- sin efectuar cambios en nuestras categorías básicas. La primera mitad proporciona un marco apropiado. Se examina la intersubjetividad, mostrando de qué forma Edmund Husserl lucha entre dos enfoques en conflicto: la realidad de las relaciones humanas y la posición estrictamente subjetiva. Citamos unos pocos fragmentos de sus borradores póstumos para dejar que el ilustre autor hable por sí mismo y para mostrar lo inciertas que eran sus ideas sobre el tema. Husserl emplea en repetidas ocasiones el término "mónada". Unas pocas citas de la Monadología de Leibniz explicarán la razón de ello.

Climate proxies in sediment core MD95-2010

High-amplitude, rapid climate fluctuations are common features of glacial times. The prominent changes in air temperature recorded in the Greenland ice cores (Dansgaard et al., 1993, doi:10.1038/339532a0; Grootes et al., 1993 doi:10.1038/366552a0) are coherent with shifts in the magnitude of the northward heat flux carried by the North Atlantic surface ocean (Bond et al., 1993, doi:10.1038/365143a0; Bond and Lotti, 1995, doi:10.1126/science.267.5200.1005); changes in the ocean's thermohaline circulation are a key component in many explanations of this climate flickering (Broecker, 1997, doi:10.1126/science.278.5343.1582). Here we use stable-isotope and other sedimentological data to reveal specific oceanic reorganizations during these rapid climate-change events. Deep water was generated more or less continuously in the Nordic Seas during the latter part of the last glacial period (60 to 10 thousand years ago), but by two different mechanisms. The deep-water formation occurred by convection in the open ocean during warmer periods (interstadials). But during colder phases (stadials), a freshening of the surface ocean reduced or stopped open-ocean convection, and deep-water formation was instead driven by brine-release during sea-ice freezing. These shifting magnitudes and modes nested within the overall continuity of deep-water formation were probably important for the structuring and rapidity of the prevailing climate changes.

Isotopic composition of terrestrial plant waxes (dD and d13C of n-alkanes) of sediment core SO188_342 from the Northern Bay of Bengal for the last 18 ka

The Indian Summer Monsoon (ISM) is a major global climatic phenomenon. Long-term precipitation proxy records of the ISM, however, are often fragmented and discontinuous, impeding an estimation of the magnitude of precipitation variability from the Last Glacial to the present. To improve our understanding of past ISM variability, we provide a continuous reconstructed record of precipitation and continental vegetation changes from the lower Ganges-Brahmaputra-Meghna catchment and the Indo-Burman ranges over the last 18,000 years (18 ka). The records derive from a marine sediment core from the northern Bay of Bengal (NBoB), and are complemented by numerical model results of spatial moisture transport and precipitation distribution over the Bengal region. The isotopic composition of terrestrial plant waxes (dD and d13C of n-alkanes) are compared to results from an isotope-enabled general atmospheric circulation model (IsoCAM) for selected time slices (pre-industrial, mid-Holocene and Heinrich Stadial 1). Comparison of proxy and model results indicate that past changes in the dD of precipitation and plant waxes were mainly driven by the amount effect, and strongly influenced by ISM rainfall. Maximum precipitation is detected for the Early Holocene Climatic Optimum (EHCO; 10.5-6 ka BP), whereas minimum precipitation occurred during the Heinrich Stadial 1 (HS1; 16.9-15.4 ka BP). The IsoCAM model results support the hypothesis of a constant moisture source (i.e. the NBoB) throughout the study period. Relative to the pre-industrial period the model reconstructions show 20% more rain during the mid-Holocene (6 ka BP) and 20% less rain during the Heinrich Stadial 1 (HS1), respectively. A shift from C4-plant dominated ecosystems during the glacial to subsequent C3/C4-mixed ones during the interglacial took place. Vegetation changes were predominantly driven by precipitation variability, as evidenced by the significant correlation between the dD and d13C alkane records. When compared to other records across the ISM domain, precipitation and vegetation changes inferred from our records and the numerical model results provide evidence for a coherent regional variability of the ISM from the Last Glacial to the present.