National University of Patagonia San Juan Bosco
Ushuaia, Argentina

The National University of the Patagonia San Juan Bosco is a higher education establishment in Patagonia, southern Argentina. It was created on February 25, 1980, by law 22.713, as the merge of two national universities: the "Universidad de San Juan Bosco" and "Universidad Nacional de la Patagonia". It is named after San Juan Bosco, patron saint of the area.The university has four schools - Engineering, Economy, Humanities, Legal, and Natural science, spread over several cities in Patagonia: Puerto Madryn, Trelew, Esquel, Comodoro Rivadavia, and Ushuaia. The central faculty is located in Comodoro Rivadavia.The University has as of 2005 14,000 students, with 5000 in the main school. Wikipedia.

Time filter
Source Type

Bond M.,CONICET | Tejedor M.F.,CONICET | Tejedor M.F.,National University of Patagonia San Juan Bosco | Campbell K.E.,Jr. | And 4 more authors.
Nature | Year: 2015

The platyrrhine primates, or New World monkeys, are immigrant mammals whose fossil record comes from Tertiary and Quaternary sediments of South America and the Caribbean Greater Antilles. The time and place of platyrrhine origins are some of the most controversial issues in primate palaeontology, although an African Palaeogene ancestry has been presumed by most primatologists. Until now, the oldest fossil records of New World monkeys have come from Salla, Bolivia, and date to approximately 26 million years ago, or the Late Oligocene epoch. Here we report the discovery of new primates from the ?Late Eocene epoch of Amazonian Peru, which extends the fossil record of primates in South America back approximately 10 million years. The new specimens are important for understanding the origin and early evolution of modern platyrrhine primates because they bear little resemblance to any extinct or living South American primate, but they do bear striking resemblances to Eocene African anthropoids, and our phylogenetic analysis suggests a relationship with African taxa. The discovery of these new primates brings the first appearance datum of caviomorph rodents and primates in South America back into close correspondence, but raises new questions about the timing and means of arrival of these two mammalian groups. ©2015 Macmillan Publishers Limited. All rights reserved.

Bell C.D.,University of New Orleans | Kutschker A.,National University of Patagonia San Juan Bosco | Arroyo M.T.K.,University of Chile
Molecular Phylogenetics and Evolution | Year: 2012

The southern Andean clade of Valeriana provides an excellent model for the study of biogeography. Here we provide new data to help clarify phylogenetic relationships among the South American valerians, with special focus on taxa found in the southern Andes. We found that the southern Andean taxa formed a clade in maximum likelihood and maximum parsimony analyses, and used a Bayesian relaxed clock method to estimate divergence times within Valerianaceae. Our temporal results were similar to other studies, but we found greater variance in our estimates, suggesting that the species of Valeriana have been on the South American continent for some time, and have been successful at exploiting new niche opportunities that reflects the contemporary radiation. Regardless of the time frame for the radiation of the clade, the uptick in the rate of diversification in Valerianaceae appears correlated with a dispersal event from Central to South America. The appearance of Valeriana in the southern Andes (13.7. Ma) corresponds with the transition from closed forest on the western side of the Andes in central Chile to a more open Mediterranean woodland environment. This would suggest that the high species richness of Valerianaceae in South America is the result of multiple, smaller radiations such as the one in the southern Andes, that may or may not be geographically isolated. These smaller radiations may also be driven by species moving into new biomes (migration from a temperate to a more Mediterranean-type climate and into alpine). The degree to which different ecological and geological factors interact to drive diversification is difficult to ascertain. Likewise, without a better-resolved phylogeny it is impossible to determine the directionality of dispersal in this group; did they colonize the southern Andes first, then move northward as the central Andean alpine habitat became more widely available or vice versa? © 2012.

Pagani M.A.,CONICET | Taboada A.C.,CONICET | Taboada A.C.,National University of Patagonia San Juan Bosco
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

Argentina is a special place to study Late Palaeozoic life and environmental change because of the excellent exposures of Late Palaeozoic sedimentary sequences. In particular, Patagonia has an almost continuous Late Palaeozoic succession containing well-preserved faunal assemblages characterized by both strong endemism and distinctive palaeobiogeographic links to Australia and northeast Asia. In this contribution an overview of the current knowledge of the invertebrate faunas of Patagonia and their biostratigraphic and palaeobiogeographic significance are presented, along with comments on the future prospects of research in the light of new findings. The Late Palaeozoic outcrops in central-western Patagonia belong to the Tepuel-Genoa Basin (Chubut province, Argentina), then located in southwestern Gondwana during the Late Palaezoic. In this basin the succession is > 6000 m thick, and constitutes a continuous and complete succession from the Lower Carboniferous to lower Permian. As such, it has the potential to serve as an important reference section for regional and intercontinental correlations. The marine Late Palaeozoic of Patagonia has yielded abundant and well-preserved representatives of most invertebrate groups: brachiopods, bivalves, gastropods, cephalopods, hyolithids, pelmatozoans, ostracods and cnidarians. Recently, studies of the Patagonian faunas have resulted in different opinions on the ages of the faunas. Biostratigraphic correlation is complex due to strong faunal provincialism. For this reason, there are several hypotheses concerning the biostratigraphic zonation in the basin. Since 1920, when studies of Late Palaeozoic strata in Patagonia were first carried out, numerous papers on stratigraphic, palaeogeographic and taxonomic subjects have been published, but our knowledge of Carboniferous-Permian fossils from the Tepuel-Genoa Basin is still incomplete. At present, we are attempting to integrate and calibrate the different faunal associations with a view to achieving a unified biostratigraphic biozonation scheme and hence a much improved understanding of the palaeobiogeographic relationship of Patagonian faunas with those from western Argentina and other continents. Currently, detailed stratigraphic and palaeontological research is being done in the type section of the Tepuel-Genoa Basin. The aim of our studies is to integrate all partial sequences exposed throughout the basin and to propose a biostratigraphic chart based on key invertebrate taxa. Once this goal is achieved, a global correlation can be conducted, especially with other sections in Gondwana and the Arctic. © 2010 Elsevier B.V.

The first records of Histiotus macrotus for Chubut Province, Argentinean Patagonia are reported here. Since November 2008 until February 2009, 24 specimens were collected in two localities in the northwest of Chubut: Ea. El Principio (42° 59' 27" S 71° 24' 60" W) and School of Welsh Language "Ysgol Gymaraeg yr Andes" (43° 05' 56" S 71° 28' 26" W). The geographic distribution of the species is extended 200 km south; additional information on its dietary habits is also reported. ©SAREM, 2010.

Hernandez M.A.,National University of Patagonia San Juan Bosco | Alvarez H.M.,National University of Patagonia San Juan Bosco
FEMS Microbiology Letters | Year: 2010

Members of the genus Rhodococcus were investigated for their ability to produce glycogen during cultivation on gluconate or glucose. Strains belonging to Rhodococcus ruber, Rhodococcus opacus, Rhodococcus fascians, Rhodococcus erythropolis and Rhodococcus equi were able to produce glycogen up to 0.2-5.6% of cellular dry weight (CDW). The glycogen content varied from 0.8% to 3.2% of CDW in cells of R. opacus PD630, which is a well-known oleaginous bacterium, during the exponential growth phase, when cultivated on diverse carbon sources. Maltose and pyruvate promoted glycogen accumulation by cells of strain PD630 to a greater extent than glucose, gluconate, lactose, sucrose or acetate. This strain was able to produce triacylglycerols, polyhydroxyalkanoates and glycogen as storage compounds during growth on gluconate, although triacylglycerols were always the main product under the conditions of this study. Cerulenin, an inhibitor of de novo fatty acid synthesis, inhibited the accumulation of triacylglycerols from gluconate and increased the content of polyhydroxyalkanoates (from 2.0% to 4.2%, CDW) and glycogen (from 0.1% to 3.0%, CDW). An increase of the polyhydroxyalkanoates and glycogen content was also observed in two mutants of R. opacus PD630, which produced reduced amounts of triacylglycerols during cultivation of cells on gluconate. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Marinao C.J.,National University of Patagonia San Juan Bosco | Yorio P.,Wildlife Conservation Society
Wilson Journal of Ornithology | Year: 2011

We evaluated seabird attendance and incidental mortality at coastal trawl vessels targeting Argentine red shrimp (Pleoticus muelleri) in the Isla Escondida fishing area, Argentina, during 20062007 and 20072008. Eight seabird species attended vessels, and the most frequent and abundant seabird (percent occurrence, mean number per haul) in the two seasons was the Kelp Gull (Larus dominicanus) (100%, 112.3 and 100%, 263.4, respectively), followed by the Black-browed Albatross (Thalassarche melanophris) (85%, 17.6, and 90%, 32.4, respectively). Eleven Magellanic Penguins (Spheniscus magellanicus) and one Imperial Shag (Leucocarbo atriceps) were killed in nets with a mean capture rate of 0.003 and 0.0003 birds per haul, respectively. The estimated total number of birds killed was 53 penguins and five shags considering the total number of hauls made by the fishery in the two seasons. No contacts between seabirds and warp cables were recorded. Coastal shrimp vessels generally operated between 15 and 20 km offshore, at a mean distance from the main Kelp Gull colony (Punta Tombo) of 43.9 km. At least 100 fish and invertebrate species were discarded, mostly Argentine hake (Merluccius hubbsi). Total amount discarded per season by this coastal fishery in the two seasons was estimated at 3,284 and 6,590 tonnes, respectively. The coastal shrimp fishery in the Isla Escondida area appears to have a small impact on seabirds in terms of incidental mortality but provides significant amounts of supplementary food during the breeding season of the Kelp Gull. © 2011 by the Wilson Ornithological Society.

The genus Valeriana is the most diverse of the Valerianaceae family and is widely distributed in temperate northern hemisphere, Africa and South America, presenting in the Andean region an important center of secondary diversification. This work includes the review of species of southern South America based on material from Argentina and Chile south of latitude 33° S. Forty species of Valeriana are described for this region, references of published illustrations are given and a key is provided for their identification. New synonymies and lectotypes based on the study of type material are included. Notes on phenology, geographic distribution and habitat, additional material examined, distinguishing characters and taxonomic affinities are also given. Some species had not been reported previously for Argentina or Chile.

Hernandez M.A.,National University of Patagonia San Juan Bosco | Arabolaza A.,National University of Rosario | Rodriguez E.,National University of Rosario | Gramajo H.,National University of Rosario | Alvarez H.M.,National University of Patagonia San Juan Bosco
Applied Microbiology and Biotechnology | Year: 2013

Rhodococcus opacus PD630 is an oleaginous bacterium able to accumulate large amounts of triacylglycerols (TAG) in different carbon sources. The last reaction for TAG biosynthesis is catalyzed by the bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) enzymes encoded by atf genes. R. opacus PD630 possesses at least 17 putative atf homologous genes in its genome, but only atf1 and atf2 exhibited a significant DGAT activity when expressed in E. coli, as revealed in a previous study. The contribution of atf1 gene to TAG accumulation by strain PD630 has been demonstrated previously, although additional Atfs may also contribute to lipid accumulation, since the atf1-disrupted mutant is still able to produce significant amounts of TAG (Alvarez et al., Microbiology 154:2327-2335, 2008). In this study, we investigated the in vivo role of atf2 gene in TAG accumulation by R. opacus PD630 by using different genetic strategies. The atf2-disrupted mutant exhibited a decrease in TAG accumulation (up to 25-30 %, w/w) and an approximately tenfold increase in glycogen formation in comparison with the wild-type strain. Surprisingly, in contrast to single mutants, a double mutant generated by the disruption of atf1 and atf2 genes only showed a very low effect in TAG and in glycogen accumulation under lipid storage conditions. Overexpression of atf1 and atf2 genes in strain PD630 promoted an increase of approximately 10 % (w/w) in TAG accumulation, while heterologous expression of atf2 gene in Mycobacterium smegmatis caused an increase in TAG accumulation during cultivation in nitrogen-rich media. This study demonstrated that, in addition to atf1 gene, atf2 is actively involved in TAG accumulation by the oleaginous R. opacus PD630. © 2012 Springer-Verlag.

Brand C.,National University of Patagonia San Juan Bosco | Miserendino M.L.,National University of Patagonia San Juan Bosco
Hydrobiologia | Year: 2011

Synchrony, one of the main traits of population life histories, refers to the degree to which individuals complete a certain stage of the life cycle at the same time. It can be governed by temperature, variations in temperature, photoperiodic cues, detritus inputs, or discharge regimes. We investigated life cycles and secondary production of five caddisfly species in a second order stream in the Patagonian Mountains. In addition, we analyzed what environmental variables were implied in the caddisfly assemblage variation. Mastigoptila sp. (Glossosomatidae) and Eosericostoma aequispina (Helicophidae), Myotrichia murina (Sericostomatidae), Brachysetodes quadrifidus (Leptoceridae), and Neoatopsyche brevispina (Hydrobiosidae) showed univoltine life cycles, with an extended recruitment with no overlapping cohorts and a relatively well-synchronized imaginal emergence taking place during spring summer seasons. However, Myotrichia murina (Sericostomatidae) displayed a complex life cycle with mixed populations taking 10-12 months to develop, and pupae being collected almost continuously. The annual secondary production per species varied from 11.06 (E. aequispina) to 310.5 mg m-2 year-1 (M. murina), being overall caddisfly production (0.5 g m-2 year-1) similar to that reported for cold springs in other regions. The highest growth rates (K) were observed during late winter and spring (mostly September) and ranged from 0.70 to 3.70% day-1 in M. longicornuta and N. brevispina, respectively. Redundancy analysis indicated that seasonally dynamic variables, water temperature, discharge, and detritus biomass were the main predictors of caddisfly assemblage variation; consequently at this cold stream (mean annual 5.9°C), with a regular availability of food supply, these parameters ruled Trichoptera life histories and secondary production. As documented for other mountainous temperate areas, synchrony would be a dominant trait on life histories of Trichoptera species inhabiting Patagonian streams. © 2011 Springer Science+Business Media B.V.

Martinez O.A.,National University of Patagonia San Juan Bosco | Kutschker A.,National University of Patagonia San Juan Bosco
Biological Journal of the Linnean Society | Year: 2011

The gravel mantels known as 'Rodados Patagónicos' of Eastern Patagonia are one of the most distinctive features of the regional landscape. Their significant roundness, along with additional sedimentary and geomorphological evidence, indicates their origin is linked to fluvial action. Currently, no natural processes exist on Earth potentially generating equivalent deposits, either in Patagonia or elsewhere around the world. The hydrological conditions responsible for the gravel formation were thus likely very different from those currently prevailing in Argentine Patagonia, suggesting the gravel mantels formed during the Late Cenozoic, when surface drainage networks of relatively high energy existed in the region. Such high energy was induced by powerful flow rates and/or strong water gradients, attributable to tectonism, epirogenesis and/or lowering of sea level. Periods with water flow regimes significantly higher than at present characterized the full glacial phases lasting several thousands of years, corresponding to each of the many glaciations of the Pliocene and Pleistocene. The capacity for erosion and water transport would have been increased by the sea level drop characteristic of each full glacial phase. There were also much shorter periods, known as 'terminations', representing the abrupt ending of the main glacial events during which large amounts of water were released as a result of the intensive melting of the Cordilleran ice sheet. During interglacial periods, in the absence of large masses of ice in the mountains and with average temperatures similar to or higher than at present, layers of gravel were deposited as a result of tectonic or epirogenic movement or by reactivation of drainage networks produced by sea level lowering (glacio-eustatism). These endogenous landscape reactivations were also independent of and longer than the climatic fluctuations and therefore overlapped with both interglacial and glacial periods. Finally, some units of the 'Rodados Patagónicos' may also have been deposited during major pluvial events, characterized by higher mean annual precipitation over sufficiently long periods. The current evidence suggests that, at various times since the Late Miocene, varied climatic conditions have allowed the production and accumulation of large gravel beds covering much of extra-Andean Patagonia. © 2011 The Linnean Society of London.

Loading National University of Patagonia San Juan Bosco collaborators
Loading National University of Patagonia San Juan Bosco collaborators