Hacer las reglas del hacer : Concepciones y rutinas bibliotecarias en los reglamentos de las bibliotecas populares en la Argentina (1870-1875)

El artículo aborda los vínculos sostenidos por la Comisión Protectora de las Bibliotecas Populares y las bibliotecas populares con relación a la elaboración de reglas adecuadas para ordenar el funcionamiento de estas instituciones. A partir de un análisis del Boletín de las Bibliotecas Populares, se estudia la manera en que la Comisión insistió en la difusión de dos servicios: la lectura gratuita en la sala y el préstamo domiciliario de libros a cambio de una cuota accesible. Se observa cómo las bibliotecas incorporaron progresivamente esas pautas y, al hacerlo, colaboraron con sus propios reglamentos con la estrategia pedagógica del Boletín. Se examinan, asimismo, las indicaciones técnicas presentes en la revista para contribuir con el desarrollo de los procesos bibliotecarios necesarios para sustentar dichos servicios. Se concluye que entre 1870 y 1875 estas acciones renovaron la tradición bibliotecaria en la Argentina, aun cuando es posible detectar diversas deficiencias y contrasentidos en la transmisión de esta nueva concepción bibliotecológica. Finalmente, se evalúa la pertinencia de los reglamentos y otros documentos institucionales para desenvolver los estudios históricos sobre los contextos de la lectura

Surface water properties, phytoplankton composition and photosynthesis rates of Amundsen Sea sites

The phytoplankton community composition and productivity in waters of the Amundsen Sea and surrounding sea ice zone were characterized with respect to iron (Fe) input from melting glaciers. High Fe input from glaciers such as the Pine Island Glacier, and the Dotson and Crosson ice shelves resulted in dense phytoplankton blooms in surface waters of Pine Island Bay, Pine Island Polynya, and Amundsen Polynya. Phytoplankton biomass distribution was the opposite of the distribution of dissolved Fe (DFe), confirming the uptake of glacial DFe in surface waters by phytoplankton. Phytoplankton biomass in the polynyas ranged from 0.6 to 14 µg Chl a / L, with lower biomass at glacier sites where strong upwelling of Modified Circumpolar Deep Water from beneath glacier tongues was observed. Phytoplankton blooms in the polynyas were dominated by the haptophyte Phaeocystis antarctica, whereas the phytoplankton community in the sea ice zone was a mix of P. antarctica and diatoms, resembling the species distribution in the Ross Sea. Water column productivity based on photosynthesis versus irradiance characteristics averaged 3.00 g C /m**2/d in polynya sites, which was approximately twice as high as in the sea ice zone. The highest water column productivity was observed in the Pine Island Polynya, where both thermally and salinity stratified waters resulted in a shallow surface mixed layer with high phytoplankton biomass. In contrast, new production based on NO3 uptake was similar between different polynya sites, where a deeper UML in the weakly, thermally stratified Pine Island Bay resulted in deeper NO3 removal, thereby offsetting the lower productivity at the surface. These are the first in situ observations that confirm satellite observations of high phytoplankton biomass and productivity in the Amundsen Sea. Moreover, the high phytoplankton productivity as a result of glacial input of DFe is the first evidence that melting glaciers have the potential to increase phytoplankton productivity and thereby CO2 uptake, resulting in a small negative feedback to anthropogenic CO2 emissions.

Hacer las reglas del hacer : Concepciones y rutinas bibliotecarias en los reglamentos de las bibliotecas populares en la Argentina (1870-1875)

El artículo aborda los vínculos sostenidos por la Comisión Protectora de las Bibliotecas Populares y las bibliotecas populares con relación a la elaboración de reglas adecuadas para ordenar el funcionamiento de estas instituciones. A partir de un análisis del Boletín de las Bibliotecas Populares, se estudia la manera en que la Comisión insistió en la difusión de dos servicios: la lectura gratuita en la sala y el préstamo domiciliario de libros a cambio de una cuota accesible. Se observa cómo las bibliotecas incorporaron progresivamente esas pautas y, al hacerlo, colaboraron con sus propios reglamentos con la estrategia pedagógica del Boletín. Se examinan, asimismo, las indicaciones técnicas presentes en la revista para contribuir con el desarrollo de los procesos bibliotecarios necesarios para sustentar dichos servicios. Se concluye que entre 1870 y 1875 estas acciones renovaron la tradición bibliotecaria en la Argentina, aun cuando es posible detectar diversas deficiencias y contrasentidos en la transmisión de esta nueva concepción bibliotecológica. Finalmente, se evalúa la pertinencia de los reglamentos y otros documentos institucionales para desenvolver los estudios históricos sobre los contextos de la lectura

Biogenic and lithogenic silica, silicic acid, production of biogenic silica, and irradiance measurements during the Ross Sea Bloom Project 1994-1996

The development of the seasonal phytoplankton bloom in the Ross Sea was studied during two cruises. The first, conducted in November-December 1994, investigated the initiation and rapid growth of the bloom, whereas the second (December 1995-January 1996) concentrated on the bloom's maximum biomass period and the subsequent decline in biomass. Central to the understanding of the controls of growth and the summer decline of the bloom is a quantitative assessment of the growth rate of phytoplankton. Growth rates were estimated over two time scales with different methods. The first estimated daily growth rates from isotropic incorporation under simulated in situ conditions, including 14C, 15N and 32Si uptake measurements combined with estimates of standing stocks of particulate organic carbon, nitrogen and biogenic silica. The second method used daily to weekly changes in biomass at selected locations, with net growth rates being estimated from changes in standing stocks of phytoplankton. In addition, growth rates were estimated in large-volume experiments under optimal irradiances. Growth rates showed distinct temporal patterns. Early in the growing season, short-term estimates suggested that growth rates of in situ assemblages were less than maximum (relative to the temperature-limited maximum) and were likely reduced due to low irradiance regimes encountered under the ice. Growth rates increased thereafter and appeared to reach their maximum as biomass approached the seasonal peak, but decreased markedly in late December. Differences between the major taxonomic groups present were also noted, especially from the isotopic tracer experiments. The haplophyte Phaeocystic antarctica was dominant in 1994 throughout the growing season, and it exhibited the greatest growth rates (mean 0.41/day) during spring. Diatom standing stocks were low early in the growing season, and growth rates averaged 0.100/day. In summer diatoms were more abundant, but their growth rates remained much lower (mean of 0.08/day) than the potential maximum. Understanding growth rate controls is essential to the development of predictive models of the carbon cycle and food webs in Antarctic waters.

Las bibliotecas populares en la Argentina entre 1870 y 1875 : La construcción de una política bibliotecaria

El artículo trata sobre la institución de las bibliotecas populares en la Argentina entre 1870 y 1875. Mediante el estudio de diversos documentos, se analizan los siguientes aspectos y sus mutuas relaciones: a. las vinculaciones entre la sociedad civil y el Estado implícitas en el dispositivo legal de fomento a las bibliotecas; b. las responsabilidades asumidas por oficina gubernamental a cargo la política bibliotecaria y la manera en que se construyó un saber especializado en la materia; c. el papel preponderante del Boletín de las bibliotecas populares como instancia de articulación entre las asociaciones y el Estado; d. los resultados cuantitativos obtenidos en la fase fundacional. En el cierre del trabajo se valoran los resultados expuestos en función de la significación histórica que tiene este período como inauguración de una manera concebir la expansión de las bibliotecas de acceso público

Geochemical analysis of minerals from sediment core CRP-2 in the Ross Sea, Antarctica

Distribution patterns, petrography, whole-rock and mineral chemistry, and shape and fabric data are described for the most representative basement lithologies occurring as clasts (granule to bolder grain-size class) from the 625 m deep CRP-2/2A drillcore. A major change in the distribution pattern of the clast types occurs at c. 310 mbsf., with granitoid-dominated clasts above and mainly dolerite clasts below; moreover, compositional and modal data suggest a further division into seven main detrital assemblages or petrofacies. In spite of this variability, most granitoid pebbles consist of either pink or grey biotite±hornblende monzogranites. Other less common and ubiquitous lithologies include biotite syenogranite, biotite-hornblende granodiorite, tonalite, monzogranitic porphyries (very common below 310 mbsf), microgranite, and subordinately, monzogabbro, Ca-silicate rocks, biotite-clinozoisite schist and biotite orthogneiss (restricted to the pre-Pliocene strata). The ubiquitous occurrence of biotite±hornblende monzogranite pebbles in both the Quaternary-Pliocene and Miocene-Oligocene sections, apparently reflects the dominance of these lithologies in the onshore basement, and particularly in the Cambro-Ordovician Granite Harbour Igneous Complex which forms the most extensive outcrop in southern Victoria Land. The petrographical features of the other CRP-2/2A pebble lithologies are consistent with a supply dominantly from areas of the Transantarctic Mountains facing the CRP-2/2A site, and they thus provide further evidence of a local provenance for the supply of basement clasts to the CRP-2/2A sedimentary strata.