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La Rioja, Argentina

The National University of La Rioja is an Argentine national university, situated in the city of La Rioja, capital of La Rioja Province. Its precursor, the Provincial University of La Rioja, was established in 1972. Wikipedia.

De Los Hoyos C.R.,CONICET | Willner A.P.,Ruhr University Bochum | Larrovere M.A.,CONICET | Larrovere M.A.,National University of La Rioja | And 3 more authors.
Gondwana Research | Year: 2011

We studied the P-T-t evolution of a mid-crustal igneous-metamorphic segment of the Famatinian Belt in the eastern sector of the Sierra de Velasco during its exhumation to the upper crust. Thermobarometric and geochronological methods combined with field observations permit us to distinguish three tectonic levels. The deepest Level I is represented by metasedimentary xenoliths and characterized by prograde isobaric heating at 20-25. km depth. Early/Middle Ordovician granites that contain xenoliths of Level I intruded in the shallower Level II. The latter is characterized by migmatization coeval with granitic intrusions and a retrograde isobaric cooling P-T path at 14-18. km depth. Level II was exhumed to the shallowest supracrustal Level III, where it was intruded by cordierite-bearing granites during the Middle/Late Ordovician and its host-rock was locally affected by high temperature-low pressure HT/LP metamorphism at 8-10. km depth. Level III was eventually intruded by Early Carboniferous granites after long-term slow exhumation to 6-7. km depth. Early/Middle Ordovician exhumation of Level II to Level III (Exhumation Period I, 0.25-0.78. mm/yr) was faster than exhumation of Level III from the Middle/Late Ordovician to the Lower Carboniferous (Exhumation Period II, 0.01-0.09. mm/yr). Slow exhumation rates and the lack of regional evidence of tectonic exhumation suggest that erosion was the main exhumation mechanism of the Famatinian Belt. Widespread slow exhumation associated with crustal thickening under a HT regime suggests that the Famatinian Belt represents the middle crust of an ancient Altiplano-Puna-like orogen. This thermally weakened over-thickened Famatinian crust was slowly exhumed mainly by erosion during ~. 180. Myr. © 2010 International Association for Gondwana Research. Source

This article describes the volcanic and sedimentary stratigraphy and their associated processes with the Andean deformation during the Late Cretaceous to Late Pliocene. The studied area is located between the Atuel and Barrancas rivers and the Main Cordillera, in southern Mendoza, Argentina. Three tectovolcanosedimentary cycles limited by regional discordances (Inca, Quechua, Pehuenche and Diaguita) are proposed. The first comprises Upper Oligocene to Upper Miocene volcanic and sedimentary units (Roca and Pircala-Coihueco formations and the Volcanic Cycle Molle). The second extends from the Late Oligocene to Late Miocene (Agua de la Piedra Formation and the Huincán Andesites volcanic cycle). Finally, the third cycle ranges from the Late Miocene to Pliocene (Butaló, Pincheiras, Loma Fiera and Rio Diamante formations and La Brea Andesites). Source

Giambastiani M.,National University of La Rioja
International Journal of Mining Science and Technology | Year: 2014

Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification (consolidation, cementation, new formed minerals), chemical sedimentary rocks and metamorphic rocks formed by minerals with Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the latter. They also include any type of rock that suffered alteration processes (hydrothermal or weathering). In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties (UCS, deformability) to physical index (porosity, density, etc.) has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text (Chihuído dam, N. Kirchner dam, J. Cepernic Dam, etc.) and others such as International Tunnel in the Province of Mendoza (Corredor Bioceánico), which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improving techniques will result in benefits to the better understanding of the geomechanics of weak rocks. © 2014 Published by Elsevier B.V. Source

Sandrone S.S.,National University of Cordoba | Repossi G.,National University of Cordoba | Repossi G.,National University of La Rioja | Candolfi M.,University of Buenos Aires | And 2 more authors.
Nutrition | Year: 2014

Certain polyunsaturated fatty acids (PUFAs) called essential fatty acids (EFAs) cannot be biosynthesized by the body and hence, need to be obtained from diet. These PUFAs and their metabolites have multiple physiological functions that are altered in tumor cells due to a decreased expression of δdelta-6-desaturase, which is an essential step in their metabolism. As a result, tumor cells would be protected from the toxic effect caused by free radicals, one product of EFA metabolism. EFAs have been proposed to have therapeutic potential in the treatment of glioblastoma. Gliomas are the most common primary tumors of the central nervous system in children and adults. High-grade gliomas remain a therapeutic challenge in neuro-oncology because there is no treatment that achieves a significant improvement in survival. Novel therapeutic strategies that use PUFAs for the treatment of gliomas have been assessed in cell cultures, rodent glioma models, and humans, with encouraging results. Here we review the latest progress made in the field. © 2014 Elsevier Inc. Source

Fernandez N.,National University of La Rioja | Theron P.,North West University South Africa | Rollard C.,French Natural History Museum
International Journal of Acarology | Year: 2013

Afticarabodes anjavidilavai gen. nov., sp. nov. and Rugocepheus joffrevillei sp. nov., both found on the island of Madagascar, are described and figured based on adult specimens, with the aid of optical and scanning electron microscopy. The genus Rugocepheus Mahunka, 2009 is redefined. © 2013 Taylor & Francis. Source

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