Estudio crítico : Martin Kusch A Sceptical Guide to Meaning and Rules. Defending Kripke's Wittgenstein, Montreal and Kingston, Ithaca, McGuill-Queen's University Press, 2006

Fil: Karczmarczyk, Pedro Diego. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Peronismo, pos-peronismo y profesionalización : Trayectorias académicas, estrategias de auto-preservación y círculos discipulares en la antropología porteña, 1945-1963

En el presente artículo se analiza el campo antropológico porteño en el período comprendido entre 1945 y 1963. El objetivo es reconstruir las trayectorias, los reposicionamientos y las estrategias adoptadas por los miembros estructuralmente significativos de la disciplina durante el peronismo y en la etapa posterior. Se sostiene que, si bien la presencia estatal modificó las condiciones de acción de los agentes (llevándolos a extender la disputa a la arena política), no parece haberse registrado una crisis de las jerarquías, un desmembramiento de los círculos discipulares ni una alteración de las reglas del orden sucesorio. Por consiguiente, la hipótesis de la que se parte es que, aunque el advenimiento del peronismo trazaría antagonismos, su impronta en el sistema disciplinar fue secundaria, predominando los mecanismos de auto-preservación, las redes de sociabilidad, las lealtades interpersonales y las afinidades electivas. En ese sentido, se pretende mostrar la operatividad de las lógicas de producción y reproducción académicas (la autonomía relativa del campo) en una etapa de enorme efervescencia política, ideológica e intelectual

Estudio crítico : Martin Kusch A Sceptical Guide to Meaning and Rules. Defending Kripke's Wittgenstein, Montreal and Kingston, Ithaca, McGuill-Queen's University Press, 2006

Fil: Karczmarczyk, Pedro Diego. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Peronismo, pos-peronismo y profesionalización : Trayectorias académicas, estrategias de auto-preservación y círculos discipulares en la antropología porteña, 1945-1963

En el presente artículo se analiza el campo antropológico porteño en el período comprendido entre 1945 y 1963. El objetivo es reconstruir las trayectorias, los reposicionamientos y las estrategias adoptadas por los miembros estructuralmente significativos de la disciplina durante el peronismo y en la etapa posterior. Se sostiene que, si bien la presencia estatal modificó las condiciones de acción de los agentes (llevándolos a extender la disputa a la arena política), no parece haberse registrado una crisis de las jerarquías, un desmembramiento de los círculos discipulares ni una alteración de las reglas del orden sucesorio. Por consiguiente, la hipótesis de la que se parte es que, aunque el advenimiento del peronismo trazaría antagonismos, su impronta en el sistema disciplinar fue secundaria, predominando los mecanismos de auto-preservación, las redes de sociabilidad, las lealtades interpersonales y las afinidades electivas. En ese sentido, se pretende mostrar la operatividad de las lógicas de producción y reproducción académicas (la autonomía relativa del campo) en una etapa de enorme efervescencia política, ideológica e intelectual

Organic matter preservation in turbidites on the Madeira Abyssal Plain

Oxidized intervals of five organic-rich Madeira Abyssal Plain (MAP) turbidites deposited during the Miocene, Pliocene, and Pleistocene all displayed comparable major loss of total organic carbon (TOC) (84 ± 3.1%) accompanied by a negative isotopic (d13C) shift ranging from -0.3 to -2.9 per mil. Major but significantly lower loss of total nitrogen (Ntot, 61 ± 7.1%) also occurred, leading to a decrease in TOC relative to Ntot (C/Ntot) and a +1.3 to 2.7 per mil Ntot isotopic (d15N) shift. Compound specific isotopic measurements on plant wax n-alkanes indicate the terrestrial organic component in the unoxidized deposits is 13C-enriched owing to significant C4 contribution. Selective preservation of terrestrial relative to marine organic carbon could account for the d13C behavior of TOC upon oxidation but only if a 13C-depleted component of the bulk terrestrial signal is selectively preserved in the process. Although the C/Ntot decrease and positive d15N shift seems inconsistent with selective terrestrial organic preservation, results from analysis of a Modern eolian dust sample collected in the vicinity indicate these observations are compatible. Regardless of the specific explanation for these isotopic observations, however, our findings provide evidence that paleoreconstruction of properties such as pCO2 using the d13C of TOC is a goal fraught with uncertainty whether or not the marine sedimentary record considered is 'contaminated' with significant terrestrial input. Nonetheless, despite major and selective loss of both marine and terrestrial components as a consequence of postdepositional oxidation, intensive organic geochemical proxies such as the alkenone unsaturation index, UK'37, appear resistant to change and thereby retain their paleoceanographic promise.

Foraminiferal abundances and preservation in ODP Hole 130-805C

Downcore changes in various carbonate dissolution indexes are documented for Hole 805C for the last 1.2 m.y. These indexes include degree of fragmentation of planktonic foraminifers, percent sand, abundance ratio of species of contrasting solution susceptibilities (Globigerinoides sacculifer vs. Pulleniatina, Globorotalia tumida, and Globorotalia menardii), and the difference in d18O between species of contrasting solution susceptibilities (G. sacculifer vs. Pulleniatina). These preservation indexes have been combined into a single composite dissolution index that corresponds closely to the d18O record. The rate of change of the oxygen isotope signal is also important, with glacial-to-interglacial transitions corresponding to maximum preservation events and vice versa. For information on changing productivity (which is important because an increased supply of organic matter may enhance dissolution by lowering pH upon degradation), we present the abundance of coarse-fraction benthic foraminifers per gram and the ratio between two planktonic foraminiferal species, one of which is strongly associated with equatorial upwelling (Globorotalia tumida vs. Pulleniatina). Our results suggest that productivity plays a subordinate role in determining foraminifer preservation. Furthermore, our results confirm previous observations that associate enhanced preservation events with glacial periods and with glacial-to-interglacial transitions. A correlation between preservation and sedimentation rates of these carbonate-rich sediments could not be established. Notable differences are present between the responses of individual dissolution indexes, indicating that processes other than dissolution determine proxy indexes to varying degrees.

Geochemistry and degree of organic carbon preservation in non-bioturbated, shaly sediments

Based on 13 published porewater H2S and sulphate profiles the amount of H2S escaping from non-bioturbated shales varies between some few % to 45% of the amount of bacterially generated H2S. This finding permits calculation of the original organic carbon (TOCor) content of immature nonbioturbated shales using TOC and sulphur content data. In two immature non-bioturbated sequences from Hungary (Toarcian and Oligocene) the first-order correlation between HI and TOC/TOCor was found to be stronger than that between HI and TOC, indicating that sulphate reduction was the leading process both in decrease in TOC content and degradation of kerogen source potential.

Aragonite distribution and preservation of sediment cores from the Brazilian Continental Slope

We present late Quaternary records of aragonite preservation determined for sediment cores recovered on the Brazilian Continental Slope (1790-2585 m water depth) where North Atlantic Deep Water (NADW) dominates at present. We have used various indirect dissolution proxies (carbonate content, aragonite/calcite contents, and sand percentages) as well as gastropodal abundances and fragmentation of Limacina inflata to determine the state of aragonite preservation. In addition, microscopic investigations of the dissolution susceptibility of three Limacina species yielded the Limacina Dissolution Index which correlates well with most of the other proxies. Excellent preservation of aragonite was found in the Holocene section, whereas aragonite dissolution gradually increases downcore. This general pattern is attributed to an overall increase in aragonite corrosiveness of pore waters. Overprinted on this early diagenetic trend are high-frequency fluctuations of aragonite preservation, which may be related to climatically induced variations of intermediate water masses.