Nuevo enlace ferrovial interprovincial Santa Fe-Entre Ríos : Una oportunidad de escala regional

La provincia de Santa Fe, Argentina, se encuentra en una localización estratégica. La potencialidad de la Hidrovía Paraná-Paraguay, los corredores bioceánicos viales y la red existente de trazados ferroviarios le confieren gran dinamismo a su integración económica, social, cultural y política, no sólo hacia el interior del propio territorio, sino también en relación a las demás provincias y más allá de los confines nacionales. La región capital, cuyo núcleo es la ciudad de Santa Fe, se encuentra caracterizada por factores realmente dinámicos: el riesgo hídrico que es intrínseco del área, la intensificación de los flujos económicos pasantes, los procesos de concentración demográfica y la creciente interdependencia entre ciudades, como es el casode Santa Fe y Paraná (capital de la vecina provincia de Entre Ríos), bajo un progresivo proceso de metropolización binuclear. Estos factores, sumados a la escasa cantidad de conexiones físicas sobre el sistema fluvial del río Paraná, han instalado la creciente necesidad de contar con un nuevo enlace interprovincial, adaptado a una hipótesis de reactivación ferroviaria. El proyecto se encuentra en fase preliminar. La cuestión principal gira en torno a la decisión de su localización específica, que deberá considerar el profundo efecto transformador propio de una obra civil de gran calibre, tanto en relación a la plataforma natural como al sistema de asentamientos humanos. También sus alcances territoriales y el impacto potencial en la micro, meso y macroescala. El propósito de la investigación reside en profundizar sobre las dimensiones involucradas por el proyecto (técnica, social, económica, ambiental, de movilidad), en la búsqueda de una toma de posición que permita echar luz sobre los escenarios más beneficiosos y/o menos desfavorables, en relación a las numerosas propuestas de localización que se encuentran actualmente en discusión. El resultado es una matriz analítica basada en variables cuantitativas y cualitativas, que permite una evaluación integral de las propuestas en función de considerar, en síntesis, el grado de impacto sobre la plataforma natural sustentante, sus capacidades para revertir las problemáticas territoriales actuales, y finalmente sus posibilidades para generar nuevos ejes de desarrollo en la región o bien potenciar los existentes. Se concluye que análisis preliminares de tipo pluridimensional son necesarios para someter a discusión, como instancia previa a estudios específicos de factibilidad y viabilidad, puesto que permiten una visualización integral de las variables intervinientes, marcando el camino hacia su adecuada ponderación. Palabras clave: enlace, multimodalidad, región, transformaciones

Séneca, didascalias y voluntad de representación

De las múltiples problemáticas planteadas por la obra trágica de Séneca, una de las que más polémica causa es la cuestión de la representación de sus obras. Numerosos y admirados eruditos han debatido hasta el cansancio sobre este tema, a menudo utilizando los mismos argumentos para tesis encontradas (Pociña, Andrés, 'Una vez más sobre la representación de las tragedias de Séneca', Emerita 41, 1973, 297-308.). En este trabajo intentamos corremos de esta discusión histórico-arqueológica para enfocamos en el entramado textual mismo en busca de pasajes claramente performativos (meso y microdidascalias textuales) que revelan una 'voluntad de representación', al menos primigenia, por parte del autor, más allá de si las obras fueron representadas o no alguna vez. El teatro antiguo tiene por convención la enunciación efectiva de las acciones escénicas y,a la vez, toda acción performativa tiene su correlato en el discurso. Estos pasajes cumplen la función de didascalias internas y responden a una voluntad del autor de influir en la representación (Issacharof, Michael, 'Voix, autorité, didascalies', Poétique 96, 1993, 463-474). La presencia de meso y microdidascalias, relevantes y fundamentales para el desarrollo dramático y trágico, son la huella rastreable de que existió una 'voluntad de representación' por parte de Séneca, al menos en el momento de creación y concepción poética de sus tragedias

Una iniciativa con Inteligencia Territorial : OPYD-OIDTE en Lavalleja, Uruguay

La creación de un espacio institucional en la IDL -Gobierno de Lavalleja- denominado OPyD-OIDTe aprobado en el Plan Quinquenal 2000-2015 y refrendado por un Convenio con la Red Científica Internacional de Inteligencia Territorial, tiene como propósito promover el desarrollo de proyectos emergentes de la comunidad -y el mundo empresario donde fuera oportuno- articulando iniciativas del Gobierno Departamental, organismos del Gobierno nacional, cooperación internacional y aportes científicos con aplicación de criterios de inteligencia territorial sustentables integrando una 'mesa de cuatro patas'. La Oficina OPyD de Promoción y Desarrollo promueve micro, meso y macro proyectos de desarrollo sustentable, mientras que el Observatorio OIDTe de Inteligencia y Desarrollo Territorial, con funciones de apoyo científico aplicado, acompaña promoviendo la concreción de proyectos con inteligencia territorial, mediante talleres y aplicación de métodos y técnicas; el enfoque transversal y orientado a la toma social participativa de decisiones para la intervención en el territorio hace de estos procesos, acciones con más sustentabilidad El trabajo se organiza en cuatro partes: qué es el Observatorio OIDTe (1); un resumen de los logros obtenidos en los primeros dos años con esta iniciativa (2), mientras que luego se pone hincapié en problemas, aprendizajes y soluciones en y con el OIDTe, en clave de inteligencia territorial, mediante intentos de articulación con las interfaces de conocimiento en Norman Long (3) y con el naciente Método Skypa propuesto por TAG UNLP-CONICET (4), con el propósito de aportar algunos grados de análisis, interpretación y sistematización acerca de dificultades tales como transformar ideas en proyectos, el paso de la fase de individuos aislados a la formación de grupos y equipos, la co-operación en los complejos procesos orientados a construir apropiación, valorización, organización y proyección colectiva, y maneras de descubrir en qué medida tienen lugar micro-procesos de transformación en conciencias, en espíritus, en miradas, en acciones y en objetos, en los sujetos y con sus territorios, entre muchos otros aspectos

Black shales from the Upper Aptian and Lower Albanian of the Volcontian Basin

Calcareous nannoplankton, palynomorph, benthic foraminifera, and oxygen isotope records from the supraregionally distributed Niveau Paquier (Early Albian age, Oceanic Anoxic Event 1b) and regionally distributed Niveau Kilian (Late Aptian age) black shales in the Vocontian Basin (SE France) exhibit variations that reflect paleoclimatic and paleoceanographic changes in the mid-Cretaceous low latitudes. To quantify surface water productivity and temperature changes, nutrient and temperature indices based on calcareous nannofossils were developed. The nutrient index strongly varies in the precessional band, whereas variations of the temperature index reflect eccentricity. Since polar ice caps were not present during the mid-Cretaceous, these variations probably result from feedback mechanisms within a monsoonal climate system of the mid-Cretaceous low latitudes involving warm/humid and cool/dry cycles. A model is proposed that explains the formation of mid-Cretaceous black shales through monsoonally driven changes in temperature and evaporation/precipitation patterns. The Lower Albian Niveau Paquier, which has a supraregional distribution, formed under extremely warm and humid conditions when monsoonal intensity was strongest. Bottom water ventilation in the Vocontian Basin was diminished, probably due to increased precipitation and reduced evaporation in regions of deep water formation at low latitudes. Surface water productivity in the Vocontian Basin was controlled by the strength of monsoonal winds. The Upper Aptian Niveau Kilian, which has a regional distribution only, formed under a less warm and humid climate than the Niveau Paquier. Low-latitude deep water formation was reduced to a lesser extent and/or on regional scale only. The threshold for the formation of a supraregional black shale was not reached. The intensity of increases in temperature and humidity controlled whether black shales developed on a regional or supraregional scale. At least in the Vocontian Basin, the increased preservation of organic matter at the sea floor was more significant in black shale formation than the role of enhanced productivity.

Abundance and biomass of zooplankton collected in 1995 and 1998 in the frontal zone between the Gulf Stream and the Labrador current

Vertical distribution of meso- and macroplankton was studied in the region of the most sharply pronounced climatic frontal zone between the Gulf Stream and the Labrador current. Hauls with a plankton net BR 113/140 and visual counts of macroplankton from the Mir submersible were used. In the frontal zone a contact occurs between arctic-boreal communities and communities of the North Atlantic subtropical gyre. The community of the North Atlantic subtropical gyre is more mature in terms of succession; many macroplanktonic carnivores-scavengers (mainly shrimps Acanthephyra) develop there and form a ''living network'' feeding on those transported from the north rich arctic-boreal mesoplankton. As a result biomass of shrimps appears to be significantly higher than biomass of their preys. Peculiarities of vertical distribution and population structure of shrimps were analyzed. Data on quantitative vertical distribution of total biomass of meso- and macroplankton and its principal groups, including gelatinous animals (ctenophores, medusas, and siphonophores) were obtained. Variations of the role of different plankton groups with depth were considered; these data enable a conclusion that frontal variations of the community structure embrace the depth range from the surface down to 2000 m.

Biomass of mesoplankton and macroplankton in the central tropical and equatorial regions of the Pacific Ocean

Collections made with 150 l sampling bottles and BR 113/140 nets, as well as direct counts from the Mir submersible are used to analyze vertical distribution of total biomass of meso- and macroplankton and biomass distributions of their main component groups in the central oligotrophic regions of the North Pacific. Biomass of mesoplankton in the upper 200 m layer ranges from 3.1 to 8.6 g/m**2, but sometimes it increases up to as much as 98 g/m**2 in local population explosions of salps. Jellies predominate in macroplankton at depths of up to 2-3 km, contributing 97-98% of live weight and 30-70% of biomass as organic carbon. In importance they are followed by micronecton fishes (up to 40% of organic carbon). Contributions of other groups countable from the submersible were negligible. Distributions of species at particular stations are discussed.

Pollen and diatom analysis on varved sediments in Lake Jues (Harz Mountains, Germany)

Studies combining sedimentological and biological evidence to reconstruct Holocene climate beyond the major changes, and especially seasonality, are rare in Europe, and are nearly completely absent in Germany. The present study tries to reconstruct changes of seasonality from evidence of annual algal successions within the framework of well-established pollen zonation and 14C-AMS dates from terrestrial plants. Laminated Holocene sediments in Lake Jues (10°20.70' E, 51°39.30' N, 241 m a.s.l.), located at the SW margin of the Harz Mountains, central Germany, were studied for sediment characteristics, pollen, diatoms and coccal green algae. An age model is based on 21 calibrated AMS radiocarbon dates from terrestrial plants. The sedimentary record covers the entire Holocene period. Trophic status and circulation/stagnation patterns of the lake were inferred from algal assemblages, the subannual structure of varves and the physico-chemical properties of the sediment. During the Holocene, mixing conditions alternated between di-, oligo- and meromictic depending on length and variability of spring and fall periods, and the stability of winter and summer weather. The trophic state was controlled by nutrient input, circulation patterns and the temperature-dependent rates of organic production and mineralization. Climate shifts, mainly in phase with those recorded from other European regions, are inferred from changing limnological conditions and terrestrial vegetation. Significant changes occurred at 11,600 cal. yr. BP (Preboreal warming), between 10,600 and 10,100 cal. yr. BP (Boreal cooling), and between 8,400 and 4,550 cal. yr. BP (warm and dry interval of the Atlantic). Since 4,550 cal. yr. BP the climate became gradually cooler, wetter and more oceanic. This trend was interrupted by warmer and dryer phases between 3,440 and 2,850 cal. yr. BP and, likely, between 2,500 and 2,250 cal. yr. BP.

Amphipods in sediment traps of the eastern Fram Strait

Life-cycle characteristics of the free-swimming lysianassoid amphipod Cyclocaris guilelmi were investigated and compared to those of other regularly appearing amphipods in the Arctic deep-sea community. In this context we analysed time-series data of meso- and bathypelagic amphipods collected as swimmers in moored sediment traps from 2004 to 2008 at the deep-sea long-term observatory HAUSGARTEN (79°N/4°E) in the eastern Fram Strait, Arctic Ocean. Six mesopelagic and three bathypelagic deep-sea amphipod species regularly occurred in the traps. The lysianassoid C. guilelmi showed a stable interannual population size and seasonal peaks in its occurrence from August to February during the five-year sampling period. The investigation of its population structure and reproduction ecology indicated year-round breeding behavior of this species. Up to 4 cohorts consisting mainly of juvenile and female C. guilelmi were observed. We conclude that C. guilelmi plays an important role within the Arctic amphipod deep water community.

Composition of bioclastic sands, carbonates and pyroclastic rocks of the Great Meteor and Josephine Seamounts, eastern North Atlantic

1. Great Meteor Seamount (GMS) is a very large (24,000 km**3) guyot with a flat summit plateau at 330-275 m; it has a volcanic core, capped by 150-600 m of post-Middle-Miocene carbonate and pyroclastic rocks, and is covered by bioclastic sands. The much smaller Josephine Seamount (JS, summit 170- 500 m w. d.) consists mainly of basalt which is only locally covered by limestones and bioclastic sands. 2. The bioclastic sands are almost free of terrigenous components, and are well sorted, unimodal medium sands. (1) "Recent pelagic sands" are typical of water depths > 600 m (JS) or > 1000 m (GMS). (2) "Sands of mixed relict-recent origin" (10-40% relict) and (3) "relict sands" (> 40% relict) are highly reworked, coarse lag deposits from the upper flanks and summit tops in which recent constituents are mixed with Pleistocene or older relict material. 3. From the carbonate rocks of both seamounts, 12 "microfacies" (MF-)types were distinguished. The 4 major types are: (1) Bio(pel)sparites (MF 1) occur on the summit plateaus and consist of magnesian calcite cementing small pellets and either redeposited planktonic bioclasts or mixed benthonic-planktonic skeletal debris ; (2) Porous biomicrites (MF 2) are typical of the marginal parts of the summit plateaus and contain mostly planktonic foraminifera (and pteropods), sometimes with redeposited bioclasts and/or coated grains; (3) Dense, ferruginous coralline-algal biomicrudites with Amphistegina sp. (MF 3.1), or with tuffaceous components (MF 3.2); (4) Dense, pelagic foraminiferal nannomicrite (MF 4) with scattered siderite rhombs. Corresponding to the proportion and mineralogical composition of the bioclasts and of the (Mgcalcitic) peloids, micrite, and cement, magnesian calcite (13-17 mol-% MgCO3) is much more abundant than low-Mg calcite and aragonite in rock types (1) and (2). Type (3) contains an "intermediate" Mg-calcite (7-9 mol-X), possibly due to an original Mg deficiency or to partial exsolution of Mg during diagenesis. The nannomicrite (4) consists of low-Mg calcite only. 4. Three textural types of volcanic and associated gyroclastic rocks were distinguished: (1) holohyaline, rapidly chilled and granulated lava flows and tuffs (palagonite tuff breccia and hyaloclastic top breccia); (2) tachylitic basalts (less rapidly chilled; with opaque glass); and (3) "slowly" crystallized, holocrystalline alkali olivine basalts. The carbonate in most mixed pyroclastic-carbonate sediments at the basalt contact is of "post-eruptive" origin (micritic crusts etc.); "pre-eruptive" limestone is recrystallized or altered at the basalt contact. A deuteric (?hydrothermal) "mineralX", filling vesicles in basalt and cementing pyroclastic breccias is described for the first time. 5. Origin and development of GMS andJS: From its origin, some 85 m. y. ago, the volcano of GMS remained active until about 10 m. y. B. P. with an average lava discharge of 320 km**3/m. y. The volcanic origin of JS is much younger (?Middle Tertiary), but the volcanic activity ended also about 9 m. y. ago. During L a t e Miocene to Pliocene times both volcanoes were eroded (wave-rounded cobbles). The oldest pyroclastics and carbonates (MF 3.1, 3.2) were originally deposited in shallow-water (?algal reef hardground). The Plio (-Pleisto) cene foraminiferal nannomicrites (MF 4) suggest a meso- to bathypelagic environment along the flanks of GMS. During the Quaternary (?Pleistocene) bioclastic sands were deposited in water depths beyond wave base on the summit tops, repeatedly reworked, and lithified into loosely consolidated biopelsparites and biomicrites (MF 1 and 2; Fig. 15). Intermediate steps were a first intragranular filling by micrite, reworking, oncoidal coating, weak consolidation with Mg-calcite cemented "peloids" in intergranular voids and local compaction of the peloids into cryptocrystalline micrite with interlocking Mg-calcite crystals up to 4p. The submarine lithification process was frequently interrupted by long intervals of nondeposition, dissolution, boring, and later infilling. The limestones were probably never subaerially exposed. Presently, the carbonate rocks undergo biogenic incrustation and partial dissolution into bioclastic sands. The irregular distribution pattern of the sands reflects (a) the patchy distribution of living benthonic organisms, (b) the steady rain of planktonic organism onto the seamount top, (c) the composition of disintegrating subrecent limestones, and (d) the intensity of winnowing and reworking bottom current

K-Ag age of volcanites from underwater rises of the Sea of Okhotsk and the Sea of Japan

New K-Ar datings of Meso-Cenozoic volcanites from the Sea of Japan and the Sea of Okhotsk were obtained. They enabled to reason age of different volcanic complexes. Basalts from volcanic edifices of the Sea of Japan Basin were determined as Middle Miocene - Pliocene (13.1-4.5 Ma) in age, which correlates well with geological evolution of the Sea of Japan. New datings for basalts from the continental slope of the South Primorye (11.1 Ma) confirm their age being similar to volcanites from Neogene basalt plateaus of the South Primorye; they are very similar not only in age but also in mineral and chemical compositions. Datings for rocks from the andesite series of the Northern Yamato Rise (24.7, 21.5 Ma) show that they are coeval with volcanites of the trachyandesite complex; this allows to combine them into one Oligocene - Early Miocene complex. In the Sea of Okhotsk datings of volcanite samples from three complexes were obtained: Cretaceous, Paleogene, and Pliocene-Pleistocene. Cretaceous magmatic rocks make part of basements of large rises in the Sea of Okhotsk, and Paleogene and Pliocene - Pleistocene complexes illustrate stages of Cenozoic tectono-magmatic activation of the region.

Distribution of late Quaternary calcareous nannofossils in DSDP Leg 96 sites

Sediments from holes drilled at 11 sites in the northern Gulf of Mexico during Deep Sea Drilling Project Leg 96 were analyzed for calcareous nannofossil content. All sediments recovered are Holocene and late Pleistocene in age and are within the Emiliania huxleyi Zone. The datum level represented by the lowest stratigraphic occurrence of dominant E. huxleyi occurs at two sites (Sites 615 and 619) and can be dated at approximately 84,000 yr. ago at Site 619. Reworked Cretaceous nannofossils are generally common or abundant and dominate the floral assemblages of the late Wisconsin glacial sediments. When present, indigenous late Quaternary species are rare or few in abundance. Slight increases in the contemporaneous Quaternary component of the floral assemblages can be documented by the use of a calculated in s/fu/reworked ratio. This ratio, based on the relative abundances of the indigenous Quaternary taxa and reworked taxa, shows potential both for local correlations between drill sites and for correlation with glacio-eustatic fluctuations during the late Pleistocene.

Representative and whole rock analyses of rocks from Filchnerfjella, Antarctica

The geological history of Filchnerfjella and surrounding areas (2°E to 8°E) in central Dronning Maud Land, East Antarctica, is constructed from metamorphic and igneous petrology, and structural investigations. The geology of Filchner-fjella consists mainly of metamorphic rocks accompanied by intrusive rocks. Two stages of metamorphism can be recognized in this area. The earlier stage metamorphism is defined as a porphyroblast stage (garnet, hornblende, and sillimanite stable), and the later one is recognized as a symplectic stage (orthopyroxene and cordieritestable). Taking metamorphic textures and geothermobarometries into account, the rocks experienced an early high-P/medium-T followed by a low-P and high-T stage. Partial melting took place during the low-P/high-T stage, because probable melt of leucocratic gneiss contains cordierite. The field relationships and petrography of the syenite at Filchnerfjella are similar to those of post-tectonic plutons from central Dronning Maud Land, and most of the post-tectonic intrusive rocks have within-plate geochemical features. The structural history in Filchnerfjella and surrounding areas can be divided into the Pan-African stage and the Meso to Cenozoic stage that relates to the break-up of Gondwana.

Vertical distribution of large particulate matter in the Western Mediterranean Sea

The relationship between mesoscale hydrodynamics and the distribution of large particulate matter (LPM, particles larger than 200 ?m) in the first 1000 m of the Western Mediterranean basin was studied with a microprocessor-driven CTD-video package, the Underwater Video Profiler (UVP). Observations made during the last decade showed that, in late spring and summer, LPM concentration was high in the coastal part of the Western Mediterranean basin at the shelf break and near the continental slope (computed maximum: 149 ?g C/l between 0 and 100 m near the Spanish coast of the Gibraltar Strait). LPM concentration decreased further offshore into the central Mediterranean Sea where, below 100 m, it remained uniformly low, ranging from 2 to 4 ?g C/l. However, a strong variability was observed in the different mesoscale structures such as the Almeria-Oran jet in the Alboran Sea or the Algerian eddies. LPM concentration was up to one order of magnitude higher in fronts and eddies than in the adjacent oligotrophic Mediterranean waters (i.e. 35 vs. 8 ?g C/l in the Alboran Sea or 16 vs. 3 ?g C/l in a small shear cyclonic eddy). Our observations suggest that LPM spatial heterogeneity generated by the upper layer mesoscale hydrodynamics extends into deeper layers. Consequently, the superficial mesoscale dynamics may significantly contribute to the biogeochemical cycling between the upper and meso-pelagic layers.

Downward particle fluxes at the oligotrophic and mesotrophic site of the EUMELI program

A two year record of downward particle flux was obtained with moored sediment traps at several depths of the water column in two regions characterized by different primary production levels (mesotrophic and oligotrophic) of the eastern subtropical North Atlantic Ocean in the framework of the EUMELI program. Settling particles were collected with multisample conical sediment-traps moored at 1000 and 2500 depths in the water column. Time-series samples were obtained between February 1991 and November 1992. During this time, sampling intervals varied from 8 to 10 d and were synchronized at all depths and also between the oligotrophic and mesotrophic moorings. Sediment-trap sampling procedures were consistent with JGOF and described elsewhere. The data shown here are mass, particulate organic carbon (POC), particulate inorganic carbon (PIC), coccolithophore, opal, and lithogenic downward fluxes obtained during the entire sediment-trap deployments at both sites.