184 research outputs found

    Implementación del método SMED en centros de mecanizado vertical y horizontal

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    Proyecto Integrador (II)--FCEFN-UNC, 2013Estudia la implementación de la metodología SMED (Single Minute Exchange Of Die) y el análisis de métodos y tiempos. Fue estudiado y analizado en el sistema productivo del sector de centros de mecanizado vertical y horizonta

    Hairy roots, their multiple applications and recent patents

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    In the last years, hairy root (HR) cultures are gaining attention in the biotechnology industry. This particular plant cell culture derives from explants infected with Agrobacterium rhizogenes. They constitute a relatively new approach to in vitro plant biotechnology and modern HR cultures are far away from the valuables findings performed by Philip R. White in the 1930´s, who obtained indefinite growth of excised root tips. HR cultures are characterized by genetic and biochemical stability and high growth rate without expensive exogenous hormones source. HR cultures have allowed a deep study of plant metabolic pathways and the production of valuable secondary metabolites and enzymes, with therapeutic or industrial application. Furthermore, the potential of HR cultures is increasing continuously since different biotechnological strategies such as genetic engineering, elicitation and metabolic traps are currently being explored for discovery of new metabolites and pathways, as well as for increasing metabolites biosynthesis and/or secretion. Advances in design of proper bioreactors for HR growth are being of great interest, since scale up of metabolite production will allow the integration of this technology to industrial processes. Another application of HR cultures is related to their capabilities to biotransform and to degrade different xenobiotics. In this context, removal assays using this plant model system are useful tools for phytoremediation assays, previous to the application in the field. This review highlights the more recent application of HRs and those new patents which show their multiple utilities.Fil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: González, Paola Solange. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

    Yoga y mindfulness: una alternativa para el desarrollo socioemocional en niños de preescolar de 3 a 6 años

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    Tesis (Educación Parvularia, Licenciado en Educación)La siguiente investigación trata de un análisis descriptivo, acerca de la utilización de las disciplinas de Yoga Kundalini infantil y Mindfulness infantil, dentro de dos establecimientos educacionales, particularmente en niños y niñas de nivel preescolar de 3 a 6 años, la cual fue realizada mediante 12 entrevistas a diferentes participantes del ámbito educacional, del ámbito del Yoga Kundalini infantil y del ámbito del Mindfulness. Por medio de esta indagación se vislumbra una alternativa educacional para el desarrollo socioemocional, permitiendo conocer los diferentes beneficios orientados a la adquisición de habilidades y herramientas, mediante metodologías que fomentan la consciencia intrapersonal e interpersonal, desde espacios compasivos que promoverían el bienestar general del Ser, recalcando la importancia del docente, desde una mirada profunda como formador humano

    Beneficio que tiene la actividad física en alumnos de Diplomado en Habilidades Laborales de la Universidad Andrés Bello Casona Las Condes

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    Tesis (Profesor de Educación Física para la Enseñanza Básica, Licenciado en Educación)El presente estudio tiene por objetivo presentar los beneficios que obtienen a través de la actividad física los estudiantes del Diploma en Habilidades Laborales (DHL) por medio del planteamiento de objetivos que definen y caracterizan los fines de la investigación, en donde la importancia del estudio radica en la percepción que tienen los estudiantes con respecto los beneficios socioafectivos, académicos y físicos de la práctica de la actividad física. Cada objetivo se relaciona directamente con las preguntas abiertas que se realizan en la entrevista y en ella se manifiestan respuestas que logran resaltar la importancia que tiene la actividad física pero también la importancia que le brinda cada estudiante, demostrando cómo la actividad física forma parte de sus vidas, la motivación y entretención que les generan los talleres deportivos que son parte de la Dirección General de Desarrollo Estudiantil (DGDE) de la Universidad Andrés Bello

    Quaternary ice sheets and sea level regression drove divergence in a marine gastropod along Eastern and Western coasts of South America

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    The southern coastline of South America is a remarkable area to evaluate how Quaternary glacial processes impacted the demography of the near-shore marine biota. Here we present new phylogeographic analyses in the pulmonate Siphonaria lessonii across its distribution, from northern Chile in the Pacific to Uruguay in the Atlantic. Contrary to our expectations, populations from the southwestern Atlantic, an area that was less impacted by ice during glacial maxima, showed low genetic diversity and evidence of recent expansion, similar to the patterns recorded in this study across heavily ice-impacted areas in the Pacific Magellan margin. We propose that Atlantic and Pacific shallow marine hard-substrate benthic species were both affected during the Quaternary in South America, but by different processes. At higher latitudes of the southeast Pacific, ice-scouring drastically affected S. lessonii populations compared to non-glaciated areas along the Chile-Peru province where the species was resilient. In the southwest Atlantic, S. lessonii populations would have been dramatically impacted by the reduction of near-shore rocky habitat availability as a consequence of glacio-eustatic movements. The increase of gravelly and rocky shore substrates in the southwest Atlantic supports a hypothesis of glacial refugia from where the species recolonized lower latitudes across the Atlantic and Pacific margins. Our results suggest that current patterns of genetic diversity and structure in near-shore marine benthic species do not solely depend on the impact of Quaternary glacial ice expansions but also on the availability of suitable habitats and life-history traits, including developmental mode, bathymetry and the likelihood of dispersal by rafting.Fil: Fernandez Iriarte, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: González Wevar, C. A.. Universidad de Chile; Chile. Universidad Austral de Chile.Instituto de Ciencias Marinas y Limnológicas; ChileFil: Segovia, N. I.. Universidad Católica del Norte; Chile. Universidad de Chile; ChileFil: Rosenfeld, S.. Universidad de Magallanes; ChileFil: Hüne, M.. Universidad de Chile; ChileFil: Fainburg, Leandro Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Nuñez, Jesus Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Haye, P. A.. Universidad Católica del Norte; ChileFil: Poulin, E.. Universidad de Chile; Chil

    Laevilacunaria (Mollusca, Gastropoda) in the Southern Ocean: A comprehensive occurrence dataset

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    The present dataset is a compilation of georeferenced occurrences of the littorinid genus Laevilacunaria Powell, 1951 (Mollusca, Gastropoda) in the Southern Ocean. Occurrence data were obtained from field expeditions (Antarctic and sub-Antarctic sampling) between 2015 and 2022, together with a review of published literature including records from 1887 to 2022. Three Laevilacunaria species have been recorded from the Southern Ocean: Laevilacunaria bennetti, L. antarctica and L. pumilio.The present dataset includes 75 occurrences, representing the most exhaustive database of this Antarctic and sub-Antarctic littorinid genus. The publication of this data paper was funded by the Belgian Science Policy Office (BELSPO, contract n°FR/36/AN1/AntaBIS) in the Framework of EU-Lifewatch as a contribution to the SCAR Antarctic biodiversity portal (biodiversity.aq)

    Evolutionary constraints on physiology confound range shift predictions of two nacellid limpets

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    Physiological comparisons are fundamental to quantitative assessments of the capacity of species to persist within their current distribution and to predict their rates of redistribution in response to climate change. Yet, the degree to which physiological traits are conserved through evolutionary history may fundamentally constrain the capacity for species to adapt and shift their geographic range. Taxa that straddle major climate transitions provide the opportunity to test the mechanisms underlying evolutionary constraints and how such constraints may influence range shift predictions. Here we focus on two abundant and shallow water nacellid limpets which have representative species on either side of the Polar front. We test the thermal thresholds of the Southern Patagonian limpet, Nacella deaurata and show that its optimal temperatures for growth (4 °C), activity (-1.2 to -0.2 °C) and survival (1 to 8 °C) are mismatched to its currently experienced annual sea surface temperature range (5.9 to 10 °C). Comparisons with the congeneric Antarctic limpet, N. concinna, reveal an evolutionary constraint on N. deaurata physiology, with overlapping thermal capacities, suggesting that a cold climate legacy has been maintained through the evolution of these species. These physiological assessments predict that the South American range of N. deaurata will likely decline with continued warming. It is, however, one of the first species with demonstrated physiological capacity to successfully colonize the cold Southern Ocean. With the expected increase in opportunities for transport within high southern latitudes, N. deaurata has the potential to establish and drive ecological change within the shallow Southern Ocean

    Survivors and colonizers: Contrasting biogeographic histories reconciled in the Antarctic freshwater copepod Boeckella poppei

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    Two main hypotheses have been proposed to explain the contemporary distribution of Antarctic terrestrial biota. We assess whether the current distribution of maritime Antarctic populations of the freshwater copepod Boeckella poppei is the result of (1) a post-Last Glacial Maximum (LGM) colonization, or whether (2) the species survived in regional glacial refugia throughout the LGM and earlier glaciations. Using 438 specimens from 34 different sampling sites across Southern South America, South Georgia, South Orkney Islands, South Shetland Islands and the Antarctic Peninsula, we analysed mitochondrial and nuclear sequences to uncover patterns of genetic diversity and population structure. We also performed median-joining haplotype network, phylogenetic reconstruction and divergence time analyses. Finally, we evaluated past demographic changes and historical scenarios using the Approximate Bayesian Computation (ABC) method. Our data support the existence of two clades with different and contrasting biogeographic histories. The first clade has been present in maritime Antarctica since at least the mid-Pleistocene, with the South Orkney Islands the most likely refugial area. The second clade has a broader distribution including southern South America, South Georgia, South Shetland Islands and the Antarctic Peninsula. The ABC method identified long-distance dispersal (LDD) colonization event(s) from southern South America to South Georgia and the maritime Antarctic after the LGM deglaciation, supporting more recent colonization of Antarctic locations. The current Antarctic and sub-Antarctic distribution of B. poppei is likely derived from two independent biogeographic events. The combination of both (1) post-LGM colonization from southern South America and (2) longer-term persistence in in situ regional refugia throughout glacial periods challenges current understanding of the biogeographic history of Antarctic freshwater biota. Re-colonization of ice-impacted Antarctic areas would have occurred following a LDD and Establishment model, pointing to the existence of possible post-dispersal barriers, despite widely assumed high passive dispersal capacity in freshwater invertebrates

    Distributional Patterns of Polychaetes Across the West Antarctic Based on DNA Barcoding and Particle Tracking Analyses

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    Recent genetic investigations have uncovered a high proportion of cryptic species within Antarctic polychaetes. It is likely that these evolved in isolation during periods of glaciation, and it is possible that cryptic populations would have remained geographically restricted from one another occupying different regions of Antarctica. By analysing the distributions of nine morphospecies, (six of which contained potential cryptic species), we find evidence for widespread distributions within the West Antarctic. Around 60% of the cryptic species exhibited sympatric distributions, and at least one cryptic clade was found to be widespread. Additional DNA barcodes from GenBank and morphological records extended the observed range of three species studied here, and indicate potential circum-Antarctic traits. Particle tracking analyses were used to model theoretical dispersal ranges of pelagic larvae. Data from these models suggest that the observed species distributions inferred from genetic similarity could have been established and maintained through the regional oceanographic currents, including the Antarctic Circumpolar Current (ACC) and its coastal counter current. Improved understanding of the distribution of Antarctic fauna is essential for predicting the impacts of environmental change and determining management strategies for the region.Copyright © 2017 Brasier, Harle, Wiklund, Jeffreys, Linse, Ruhl and Glover. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

    Complete distribution of the genus Laevilitorina (Littorinimorpha: Littorinidae) in the Southern Hemisphere: remarks and natural history

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    Littorinid snails are present in most coastal areas globally, playing a significant role in the ecology of intertidal communities. Laevilitorina is a marine gastropod genus distributed exclusively in the Southern Hemisphere, with 21 species reported from South America, the sub-Antarctic islands, Antarctica, New Zealand, Australia and Tasmania. Here, an updated database of 21 species generated from a combination of sources is presented: 1) new field sampling data; 2) published records; 3) the Global Biodiversity Information Facility (GBIF) and The Atlas of Living Australia (ALA), to provide a comprehensive description of the known geographic distribution of the genus and detailed occurrences for each of the 21 species. The database includes 813 records (occurrences), 53 from field sampling, 174 from the literature, 128 from GBIF, and 458 from ALA. West Antarctica had the highest species richness (8 species), followed by sub-Antarctic islands of New Zealand (4 species) and the south-east shelf of Australia (4 species). The provinces of Magellan, New Zealand South Island, and sub-Antarctic Islands of the Indian Ocean include two species each. This study specifically highlights reports of L. pygmaea and L. venusta, species that have been almost unrecorded since their description. Recent advances in molecular studies of L. caliginosa showed that this species does not correspond to a widely distributed taxon, but to multiple divergent lineages distributed throughout the Southern Ocean. Ongoing molecular and taxonomic studies are necessary for a better understanding of the diversity and biogeography of this genus
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