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Villa General Belgrano, Argentina

The National University of Río Negro is a public institution of higher learning located in Río Negro Province, Argentina, and established in 2007 as part of a plan to geographically diversify Argentina's National University system.The university maintains campuses throughout Río Negro Province, one of Argentina's most-sparsely populated: Bariloche, Choele Choel, El Bolsón, General Roca, San Antonio Oeste, Viedma, and Villa Regina. The school offers 25 undergraduate courses and one post-graduate. Wikipedia.

Murriello S.,National University of Rio Negro
Public Understanding of Science | Year: 2015

Understanding the dialogue between museums and their visitors enables museums to subsist, undergo transformations and become consolidated as socially valued cultural venues. The Museo de La Plata (Argentina) was created in the late nineteenth century as a natural history museum, and this study shows that currently the museum is valued socially as a venue for family leisure and education, at which people make sense to the objects exhibited through characteristics conferred upon them by both the institution and the visitor. Nevertheless, such dialogue is somehow affected by the museographic proposal and the public interpretation of the institutional narrative, which could be analysed within the frame of contextual learning. As a consequence, the evolutionary idea that the museum aims to communicate is distorted by the public. This article highlights the importance of considering the visitors’ interpretations when planning museum exhibitions, a perspective that has been rather absent in the Argentinian museums. © The Author(s) 2015.

Ponce J.J.,National University of Rio Negro | Carmona N.,CONICET
Geology | Year: 2011

In this paper we present an outcrop example of coarse-grained sediment waves generated by hyperpycnal discharges at the toe of Miocene clinoform systems exposed in the northeast Atlantic coast of Tierra del Fuego, Argentina. An individual set of these sediment waves is formed during the waxing and waning phases of the hyperpycnal discharge. During the waxing phase, accumulation of coarse-grained sediments with generation and migration of dune bedforms occurs at the base of the clinoforms. These deposits show transitions of tractive sedimentary structures with evidence of bedload transport, and a continuous reworking by the overpassing hyperpycnal flow. The continued erosion and reworking during the waxing phase affect mainly the top and the stoss side of the dunes, resulting in isolated lenses having upcurrent aggradation structures. During the waning phase, these isolated lenses are covered by fine-grained heterolithic strata that are thicker on the stoss side than on the lee side, constituting a differential draping. The pulsating and sustained character of the hyperpycnal flows and the steep depositional slope clinoforms controlled the stacking pattern of the coarse-grained sediment waves during successive hyperpycnal events. In this way, small-scale, coarse-grained sediment waves, with wavelengths of 10-40 m and up to 5 m amplitude, and a stacking pattern showing an up-current growth, are generated by high-density hyperpycnal flows on slopes having steep gradients. © 2011 Geological Society of America.

Giambiagi L.,CONICET | Mescua J.,CONICET | Bechis F.,National University of Rio Negro | Tassara A.,University of Concepcion | Hoke G.,Syracuse University
Bulletin of the Geological Society of America | Year: 2012

The Andean fold-and-thrust belts of westcentral Argentina (33 S and 36 S), above the normal subduction segment, present important along-strike variations in mean topographic uplift, structural elevation, amount and rate of shortening, and crustal root geometry. To analyze the controlling factors of these latitudinal changes, we compare these parameters and the chronology of deformation along 11 balanced crustal cross sections across the thrust belts between 70 W and 69 W, where the majority of the uppercrustal deformation is concentrated, and reconstruct the Moho geometry along the transects. We propose two models of crustal deformation: a 33 40 S model, where the locus of upper-crustal shortening is aligned with respect to the maximum crustal thickness, and a 35 40 S model, where the uppercrustal shortening is uncoupled from the lower-crustal deformation and thickening. This degree of coupling between brittle upper crust and ductile lower crust deformation has strong influence on mean topographic ele vation. In the northern sector of the study area, an initial thick and felsic crust favors the coupling model, while in the southern sector, a thin and mafic lower crust allows the uncoupling model. Our results indicate that interplate dynamics may control the overall pattern of tectonic shortening; however, local variations in mean topographic elevation, deformation styles, and crustal root geometry are not fully explained and are more likely to be due to upper-plate lithospheric strength variations. © 2012 Geological Society of America.

During the Mesozoic, one of the most significant evolutionary processes was the secondary adaptation of tetrapods to life in water. Several non-related lineages invaded from the terrestrial realms and from the oceans of the entire world. Among these lineages, ichthyosaurs were particularly successful. Advance parvipelvian ichthyosaurs were the first tetrapods to evolve a fish-shaped body profile. The deep skeletal modifications of their bodies, as well as their biology, depict advance ichthyosaurs as the paradigm of secondary adaptation of reptiles tomarine life. Functional inferences point to themas off-shore cruising forms, similar to a living tuna, and some of them were capable of deep diving. Bone histology of some genera such as Temnodontosaurus, Stenopterygius, Ichthyosaurus, and Caypullisaurus, characterized by overall cancellous bone, is consistent with the idea of a fish-shaped ichthyosaurs as fast and far cruisers. Here, we provide histological examination of the ribs of the Middle Jurassic parvipelvian Mollesaurus. Contrasting with the bone histology of other parvipelvian, Mollesaurus ribs are characterized by a compact and thick cortex. Our data indicate that the rib cage was heavy and suggest that not all advanced ichthyosaurs were fast cruisers. The compact and dense ribs in these parvipelvian show that advance ichthyosaurs were ecologically more diverse than previously thought and that the lightening of the skeleton reversed, as also occurred in the evolution of cetacean, at least once along the evolutionary history of ichthyosaurs. © Springer-Verlag 2012.

Fernandez M.S.,Museo de La Plata | Talevi M.,National University of Rio Negro
Geological Magazine | Year: 2014

The oldest ophthalmosaurian records worldwide have been recovered from the Aalenian-Bajocian boundary of the Neuquén Basin in Central-West Argentina (Mendoza and Neuquén provinces). Although scarce, they document a poorly known period in the evolutionary history of parvipelvian ichthyosaurs. In this contribution we present updated information on these fossils, including a phylogenetic analysis, and a redescription of 'Stenopterygius grandis' Cabrera, 1939. Patagonian ichthyosaur occurrences indicate that during the Bajocian the Neuquén Basin palaeogulf, on the southern margins of the Palaeopacific Ocean, was inhabited by at least three morphologically discrete taxa: the slender Stenopterygius cayi, robust ophthalmosaurian Mollesaurus periallus and another indeterminate ichthyosaurian. Rib bone tissue structure indicates that rib cages of Bajocian ichthyosaurs included forms with dense rib microstructure (Mollesaurus) and forms with an 'osteoporotic-like' pattern (Stenopterygius cayi). Copyright © Cambridge University Press 2013.

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