El escepticismo de Hume en la investigación sobre el entendimiento humano

Fil: Elgarte, Julieta Magdalena. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Part of the global DOC versus AOU (dissolved organic carbon/apparent oxygen utilization) data compilation, Ross Sea

Dissolved and particulate organic matter was measured during six cruises to the southern Ross Sea. The cruises were conducted during late austral winter to autumn from 1994 to 1997 and included coverage of various stages of the seasonal phytoplankton bloom. The data from the various years are compiled into a representative seasonal cycle in order to assess general patterns of dissolved organic matter (DOM) and particulate organic matter (POM) dynamics in the southern Ross Sea. Dissolved organic carbon (DOC) and particulate organic carbon (POC) were at background concentrations of approximately 42 and 3 µM C, respectively, during the late winter conditions in October. As the spring phytoplankton bloom progressed, organic matter increased, and by January DOC and POC reached as high as 30 and 107 µM C, respectively, in excess of initial wintertime conditions. Stocks and concentrations of DOC and POC returned to near background values by autumn (April). Approximately 90% of the accumulated organic matter was partitioned into POM, with modest net accumulation of DOM stocks despite large net organic matter production and the dominance of Phaeocystis antarctica. Changes in NO3 concentration from wintertime values were used to calculate the equivalent biological drawdown of dissolved inorganic carbon (DICequiv). The fraction of DICequiv drawdown resulting in net DOC production was relatively constant (ca. 11%), despite large temporal and spatial variability in DICequiv drawdown. The C : N (molar ratio) of the seasonally produced DOM had a geometric mean of 6.2 and was nitrogen-rich compared to background DOM. The DOM stocks that accumulate in excess of deep refractory background stocks are often referred to as "semi-labile" DOM. The "semi-labile" pool in the Ross Sea turns over on timescales of about 6 months. As a result of the modest net DOM production and its lability, the role DOM plays in export to the deep sea is small in this region.

Distribution of phytolithes in CRP sediment cores from the Ross Sea, Antarctica

Phytoliths (siliceous plant microfossils) have been recovered from Cenozoic sediments (c. 34 to 17 Ma) in the CRP-2/2A and CRP-3 drillholes cored off Cape Roberts, Victoria Land Basin, Antarctica. The phytolith assemblages are sparse, but well-preserved and dominated by spherical forms similar to those of modern trees or shrubs. Rare phytoliths comparable to modern grass forms are also present. However, due to the paucity of phytolith data, any interpretations made are necessarily tentative. The assemblages of CRP-2/2A and the upper c. 250 m of CRP-3 are interpreted as representing a predominantly woody vegetation, including Nothofagus and Libocedrus with local areas of grass in the more exposed locations. A cool climate is interpreted to have prevailed throughout both cores. However, beneath c. 250 metres below sea floor in CRP-3, the dominant woody vegetation is supplemented by pockets of Palmae, ?Proteaceae and 'warm' climate grasses. This association represents vegetation growth in sheltered, moist sites - possibly north-facing mid-slopes or the coastal fringe. It may also represent remnant vegetation that grew in moist, temperate conditions during the Middle to Late Eocene, previously interpreted from the Southern McMurdo Sound erratics and lower part of the CIROS-1 drillhole. The phytolith analysis compares well to the terrestrial palynomorph record from both cores and provides additional independent taxonomic and climatic interpretations.

¿Saldrá el sol mañana? El sentido de la probabilidad en Hume a la luz de su contexto histórico filosófico

Fil: Calvente, Sofía Beatriz. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Soil characteristics and abundance of archaea in samples from the Ross Sea Region, Antarctica

The objective of this study was to examine the presence and diversity of Archaea within mineral and ornithogenic soils from 12 locations across the Ross Sea region. Archaea were not abundant but DNA sufficient for producing 16S rRNA gene clone libraries was extracted from 18 of 51 soil samples, from four locations. A total of 1452 clones were analysed by restriction fragment length polymorphism and assigned to 43 operational taxonomic units from which representatives were sequenced. Archaea were primarily restricted to coastal mineral soils which showed a predominance of Crenarchaeota belonging to group 1.1b (>99% of clones). These clones were assigned to six clusters (A through F), based on shared identity to sequences in the GenBank database. Ordination indicated that soil chemistry and water content determined archaeal community structure. This is the first comprehensive study of the archaeal community in Antarctic soils and as such provides a reference point for further investigation of microbial function in this environment.

El milagro de creer en milagros : La crítica de Hume a la idea de un dios providencial

Fil: Calvente, Sofía Beatriz. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

David Hume y el escepticismo : Algunas pistas para un acertijo

Fil: Di Berardino, María Aurelia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Consideraciones sobre la noción de experiencia en David Hume y William James

Fil: Calvente, Sofía Beatriz. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

David Hume y las neuronas espejo : una actualización de la teoría del sentimiento de empatía

El objetivo de esta ponencia será dar cuenta del modo en que los avances producidos en el campo de la neurociencia vienen a sustentar la intuición humeana de la motivación moral arraigada en un sentimiento de empatía. A este fin se realizará un breve recorrido por los puntos fundamentales en la concepción moral de Hume y se expondrán algunos resultados obtenidos en el área neurocientífica respecto al descubrimiento de las neuronas espejo en los macacos, y la posterior investigación de la existencia de dichas neuronas en el hombre. Por último, se señalarán las similitudes que estas actuales investigaciones tienen con la noción de empatía humeana, pretendiendo aportar de esta manera solidez a las ideas del filósofo escocés