Megaemprendimientos vs 'Micro' emprendimientos : Economía social y pequeña producción en la estepa patagónica rionegrina

En este trabajo analizaré la postura ecofeminista de la filósofa y científica india Vandana Shiva, respecto a las nociones de 'violencia contra la naturaleza', 'mal desarrollo', 'pobreza', 'monocultivo de la mente', 'conocimiento de las mujeres', 'globalización', entre otras, en relación al contexto economíco-socio-cultural específico de la línea sur rionegrina. En términos generales, abordaré la cuestión de cómo estas nociones pueden utilizarse (salvando algunas diferencias contextuales) para explicar el saqueo y sobreexplotación de los recursos naturales en nuestro país, la expulsión (directa e indirecta) de pueblos originarios y la indiferencia gubernamental hacia otros tipos de emprendimientos de desarrollo económico regional. Se tomará el caso particular de lo que sucede actualmente en la Línea Sur de Río Negro a manera de ilustración, sin buscar generalizaciones demasiado abarcativas. Estas tierras son especialmente significativas porque son aquellas tierras improductivas (inútiles para pastoreo y muy frías) a las que fueron empujados los araucanos sobrevivientes post-conquista, que ahora ven nuevamente amenazadas por la explotación megaminera impulsada desde el Estado como única forma de 'desarrollo económico'. Simultáneamente, al proyecto de 'desarrollo económico' megaminero, se lo comparará con la alternativa de desarrollo económico regional, llamada 'Mercado de la Estepa',en relación a la Ley de Economía Social, que actualmente defiende -junto con otros mercados similares en lugares donde no ha sido sancionada aun-

Animation of micro-computed tomography of bioerosion trace Entobia megastoma made by East Australian bioeroding sponge Cliona celata

Endolithic bioerosion is difficult to analyse and to describe, and it usually requires damaging of the sample material. Sponge erosion (Entobia) may be one of the most difficult to evaluate as it is simultaneously macroscopically inhomogeneous and microstructurally intricate. We studied the bioerosion traces of the two Australian sponges Cliona celata Grant, 1826 (sensu Schönberg 2000) and Cliona orientalis Thiele, 1900 with a newly available radiographic technology: high resolution X-ray micro-computed tomography (MCT). MCT allows non-destructive visualisation of live and dead structures in three dimensions and was compared to traditional microscopic methods. MCT and microscopy showed that C. celata bioerosion was more intense in the centre and branched out in the periphery. In contrast, C. orientalis produced a dense, even trace meshwork and caused an overall more intense erosion pattern than C. celata. Extended pioneering filaments were not usually found at the margins of the studied sponge erosion, but branches ended abruptly or tapered to points. Results obtained with MCT were similar in quality to observations from transparent optical spar under the dissecting microscope. Microstructures could not be resolved as well as with e.g. scanning electron microscopy (SEM). Even though sponge scars and sponge chips were easily recognisable on maximum magnification MCT images, they lacked the detail that is available from SEM. Other drawbacks of MCT involve high costs and presently limited access. Even though MCT cannot presently replace traditional techniques such as corrosion casts viewed by SEM, we obtained valuable information. Especially for the possibility to measure endolithic pore volumes, we regard MCT as a very promising tool that will continue to be optimised. A combination of different methods will produce the best results in the study of Entobia.

(Table 1) Micro-inclusion counts and ion concentrations in the five GRIP ice-core sections

We provide the first direct evidence that a number of water-soluble compounds, in particular calcium sulfate (CaSO4 2H2O) and calcium carbonate (CaCO3), are present as solid, micron-sized inclusions within the Greenland GRIP ice core. The compounds are detected by two independent methods: micro-Raman spectroscopy of a solid ice sample, and energy-dispersive X-ray spectroscopy of individual inclusions remaining after sublimation. CaSO4 2H2O is found in abundance throughout the Holocene and the last glacial period, while CaCO3 exists mainly in the glacial period ice. We also present size and spatial distributions of the micro-inclusions. These results suggest that water-soluble aerosols in the GRIP ice core are dependable proxies for past atmospheric conditions.

Micro- and picoplankton in waters of the Saint Paul Island, Pribilof Islands, Bering Sea

On the basis of materials collected in June-August 1994 characteristic data on microplankton were gathered in three biotopes of the eastern shelf of the Bering Sea: open shelf (coastal zone), the harbor, and the salt lagoon of Saint Paul Island (Pribiof Islands). The following parameters of microplanktonic communities were analyzed: abundance, biomass, and production of autotrophic picoplankton (picoalgae and cyanobacteria); abundance, biomass, growth rate constant, and production of bacterioplankton; role of filiform bacteria in bacterioplankton; species composition of heterotrophic flagellates and ciliates, their abundance, and biomass. Growth rates and consumption rates of picoplankton and bacterioplankton by heterotrophic nano- and microplankton were estimated in the experiments using the dilution method. Temporal dynamics of all structural and functional parameters of microplankton were analyzed. The minor role of autotrophic picoplankton and significant role of bacterioplankton as well as heterotrophic nano- and microplankton in planktonic communities of studied biotopes during summer months was shown. During certain periods, bacterial biomass was as high as 50-65% of phytoplankton biomass, and production of bacteria was as high as 20-40% of primary production. In the middle of the season biomass of nano- and microheterotrophic organisms in different biotopes exceeded biomass of mesozooplankton 2-10 times. Average consumption of bacterial production by nano- and microplankton during the period of observations was 85-94%.