La Rioja, Argentina

National University of La Rioja
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.

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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.

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

This is the first part of a revision of the family Carabodidae by us. The new genus Bovicarabodes comprises three new species from Madagascar, Bovicarabodes deharvengi, Bovicarabodes levyi and Bovicarabodes fortdauphini, which are described and illustrated. Many morphological aspects found in the genus Bovicarabodes, that also exist in several other genera but have not been described before, are introduced and discussed in particular sections such as "Protection mechanisms" and "Medial eye". Other Carabodid genera which also present these features are indicated, studied and compared. The study is based on adult specimens using optical and scanning electron microscopy. The system of leg folding as well as the structure of the medial eyes were studied and compared to type material of many other Carabodid genera. A redescription of Hardybodes mirabilis Balogh, 1970, based on a study of the type material, is included. F7E57D3B-026C-4763-80ED-42E2B0CF8EDF © 2013 Copyright 2013 Taylor & Francis.

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.

Fiorelli L.E.,Centro Regional Of Investigaciones Cientificas Y Transferencia Tecnologica Crilar | Grellet-Tinner G.,Centro Regional Of Investigaciones Cientificas Y Transferencia Tecnologica Crilar | Alasino P.H.,Centro Regional Of Investigaciones Cientificas Y Transferencia Tecnologica Crilar | Alasino P.H.,National University of La Rioja | Arganaraz E.,CIPAL
Cretaceous Research | Year: 2012

The recent discovery of the Cretaceous Sanagasta geothermal nesting site in the Los Llanos Formation, La Rioja Province, northwestern Argentina, has shed light on new and unexpected neosauropod reproductive behaviours. Here we recapitulate the palaeontological discovery at Sanagasta and the oological characterization of the nesting site (reported in 2010). In addition, we describe in detail the geology, sedimentology, petrology, and geochemistry of the nesting site with the goals of assessing the palaeoenvironment of the Los Llanos Formation at this site. The Sanagasta Geologic Park, where the nesting site is located, represents a local expression of a geothermal process that occured in the Sierras Pampeanas during the Cretaceous Period. This geothermal cycle allows for the first time an Early Cretaceous dating (Hauterivian-Aptian) for the Los Llanos Formation, which is further supported by the occurrence of notosuchians, and ornithopod, sauropod and theropod dinosaurs in other exposures of the same formation in La Rioja Province. As such, in addition to shedding light on neosauropod palaeobiology and their nesting environment, this investigation clarifies longstanding geological issues pertaining to the sedimentary basins in the Sierras Pampeanas Orientales (central-west Argentina). © 2011 Elsevier Ltd.

Canali M.M.,National University of Cordoba | Porporatto C.,National University of Cordoba | Aoki M.P.,National University of Cordoba | Bianco I.D.,National University of La Rioja | Correa S.G.,National University of Cordoba
Vaccine | Year: 2010

Chitosan is a copolymer of N-acetylglucosamine and glucosamine derived from chitin with several applications in pharmaceutical and medical fields. This polysaccharide exhibits adjuvant properties in mucosal immune responses of humans, rats and mice. Characterization of signals elicited by chitosan at the intestinal epithelium could explain its immunomodulatory activity and biocompatibility. We fed normal rats with single doses of chitosan and 16. h later, we purified intestinal epithelial cells (IECs) to assess immune and biochemical parameters. Following chitosan administration, mRNA expression and release of several cytokines and chemokines increased, injury markers maintained constitutive levels and MHC type II molecule expression was augmented. IEC supernatants showed higher levels of IL-10, IL-6 and TGF-β. Arginase activity of IECs increased upon chitosan interaction in vivo and in vitro. Together, after chitosan feeding, mild activation of IECs occurs in vivo, with production of regulatory factors that could be relevant for its biocompatibility and immunomodulatory effects. © 2010 Elsevier Ltd.

Rustan J.J.,National University of La Rioja | Vaccari N.E.,National University of Cordoba
Revista Mexicana de Ciencias Geologicas | Year: 2012

Maurotarion megacephalum sp. nov., from the Pragian (Lower Devonian) of the Talacasto Formation, Precordillera basin, central-west Argentina, is described and interpreted as the first Malvinokaffric species of the genus outside the endemic subgenus M. (Malvinotarion). Based mainly on librigenal characters, the coeval M. periergum, from the Wenban Limestone, Nevada, U. S. A., is considered the closest allied taxon. Both species are interpreted as those most closely related to M. (Malvinotarion). Evidence suggests faunal exchange between low and high paleolatitudes for the Pragian, a hypothesis previously discarded in light of low sea level conditions interpreted during this time, and linked to a pattern of vicariance and radiation previously recognized from Malvinokaffric Maurotarion species.

Nullo F.,CONICET | Combina A.,CONICET | Combina A.,National University of La Rioja
Biological Journal of the Linnean Society | Year: 2011

We review stratigraphic records from various continental basins throughout Patagonia from the Cretaceous to the Late Tertiary and show that they can be used to reconstruct the history of the region, including the number and extension of marine transgressions as a result of sea level changes, changes in climate, and changes in the composition of the vertebrate fauna. The various independent sedimentary basins are analyzed with respect to internal facies relationships and in relation to global changes in climate and oscillations of sealevel. Volcanic processes associated with active volcanic arcs contributed lavas and substantial volumes of pyroclastics during this time interval. The interplay between different geological processes that took place during this time shaped the landscape of the continent and changed the associated flora and fauna, which were developed in this region, differing from other areas of southern South America and part of West Antarctica. © 2011 The Linnean Society of London.

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).

Giambastiani M.,National University of La Rioja
Underground - The Way to the Future: Proceedings of the World Tunnel Congress, WTC 2013 | Year: 2013

Tunneling in Argentina, in its modern concept, had its beginning with the development of the national railway network and had its maximum expression between the late XIX century and the early XX century, when 16,8 km of tunnels were built. Another important moment in tunnel engineering, was the development of the subway in Buenos Aires city, the first in Latin America, whose building started in 1911 with the A line. At the present time, 3,9km of tunnels were built. The roadway tunnels began in the 40's and they reached their maximum development in the 80's. In 1969, the first and unique immersed tunnel in South America (Uranga - Begnis Tunnel), was inaugurated under the Paraná river. 9,8 km of road tunnels were built altogether. The different hydroelectric project, developed in the second half of the XX century, gave a great impulse to the construction of tunnels and galleries( aprox. 86,9 km) Among the future projects, it must be highlighted the Agua Negra international roadway tunnel, the railway tunnels of Corredor Bioceánico, the enlargement of the subway in Buenos Aires and the subway project in Córdoba. © 2013 Taylor & Francis Group.

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.

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