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Sample records for channel southern tierra

  1. Feeding habits of the false southern king crab Paralomis granulosa (Lithodidae in the Beagle Channel, Tierra del Fuego, Argentina

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    Laura Inés Comoglio

    1999-12-01

    Full Text Available Stomach contents of 282 false southern king crabs (Paralomis granulosa, between 10 to 90 mm CL from the Beagle Channel (Golondrina Bay and Roca Mora, Argentina, were examined by the frequency of occurrence method of analysis and by a food index. Roca Mora is an area where juveniles ( 60 mm CL are common; in this last area sexual segregation was also observed. The principal food groups for crabs of Golondrina Bay were algae, molluscs, crustaceans, bryozoans and foraminiferans; for crabs from Roca Mora the natural diet consisted of three major food groups: hydrozoans, echinoderms and foraminiferans. The relative frequency of different prey groups varied in relation to the size, season and sex. There were no significant differences in the quantity of food consumed by sexes in both areas. Generally small crabs ( 50 mm CL. Juveniles consumed a greater amount of food during winter and spring. In summer (moulting period, juveniles had the highest vacuity index. Adults consumed minor amounts of food during autumn, before the spawning-moulting-mating period when the vacuity index was higher (spring.

  2. CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

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    Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

    2015-04-01

    South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

  3. A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego

    Energy Technology Data Exchange (ETDEWEB)

    Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C; Austin, J A; Anselmetti, F S

    2010-11-19

    Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived precipitation. Increased wind strength and precipitation in the late Holocene drives the Nothofagus forest eastward and enhances run-off and terrigenous inputs to the lake. Superimposed on the long-term trend are a series of abrupt 9 negative departures in C/N ratio, which constrain the presence of seismically-driven mass flow events in the record. We identify an increase in bulk {delta}{sup 13}C between 7,000 and 5,000 cal yr BP that we attribute to enhanced aquatic productivity driven by warmer summer temperatures. The Lago Fagnano {delta}{sup 13}C record shows similarities with Holocene records of sea surface

  4. Channel Responses and Hydromodification in Southern California

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    Hawley, R. J.; Dust, D. W.; Bledsoe, B. P.

    2007-12-01

    Hydromodification (changes in watershed hydrologic characteristics, and the resulting hydraulics and channel forms due to urbanization) is ubiquitous in Southern California. In this region, the effects of hydromodification are driven and compounded by the arid/semiarid climate, high relief, erodible soils, high urbanization rates, and relatively low frequency of retention/detention. We conducted a preliminary survey of over 50 stream reaches along a gradient from least disturbed to fully urbanized. All stages of the Channel Evolution Model (CEM) of Schumm et al. (1984) were observed, from stable to degrading, widening, aggrading, and quasi-equilibrium channels. Several sites have CEM stages II through V in close proximity due to headcutting, hardpoints, and infrastructure. We also observed channels in undeveloped watersheds impacted by downstream urbanization via headcutting. A range of intervention measures was observed, with the frequent evolutionary endpoint as a concrete engineered flood control channel. We also observed multiple channel evolution sequences that deviate from the CEM for single-thread, incising channels. An alternative channel response, particularly on smaller urbanized streams is a stabilized, vegetation encroached low-flow channel with regular baseflow supplied by residential irrigation runoff. The limited cases of unimpacted streams that remain tend to be high gradient, high energy systems that are naturally proximate to the transition between braided and meandering form for a given sediment size.

  5. Species richness and faunistic affinities of the Gammaridea and Corophiidea (Amphipoda from shallow waters of southern Tierra del Fuego, Argentina: preliminary results

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    Ignacio Luis Chiesa

    2005-12-01

    Full Text Available Species richness and faunistic affinities of gammaridean and corophiidean amphipods from southern Tierra del Fuego were studied. The material was collected with dredges and grabs at 7 locations (15 sampling stations in a range of 5 to 35 m depth. A total of 61 species belonging to 20 families and 43 genera were identified. The genera Cephalophoxoides, Ceradocopsis and Photis are reported for the first time from the Magellan region and 3 species belonging to Atylus, Ischyrocerus and Photis appear to be new to science. Most of the species collected belong to Phoxocephalidae, whereas most individuals were contained in the Stenothoidae and Lysianassidae s.l. The analysis of the faunistic affinities showed that 16 species (39% are endemic to the Magellan region, 9 species (22% extend to the south, 5 species (12.2% to the north and 5 other species (12.2% to both the north and south. In addition, 6 species extend beyond the Magellan region as far as Oceania.

  6. Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

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    Maltchik, Leonardo; Rolon, Ana Silvia; Stenert, Cristina; Machado, Iberê Farina; Rocha, Odete

    2011-12-01

    Conservation of species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1) Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2) Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006). A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production.

  7. El fin de la tierra

    OpenAIRE

    Benitez Peña, Frank

    2014-01-01

    Ana Faura, una representante de una asociación de desplazados, desea recuperar la tierra que le fue arrebatada para enterrar allí los restos óseos de su esposo asesinado y volver a una vida que añora. En su propósito deberá enfrentarse no solo a amenazas de muerte en contra suya y de su único hijo sino a la necesidad de perdonar a los victimarios para lograr un verdadero retorno.

  8. La Memoria De Nuestra Tierra: Colorado

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    Baca, Judy

    2005-01-01

    La Memoria de Nuestra Tierra combines a meticulously hand-painted landscape with historic photographs in a seamless blend imprinted on the holographic-like surface of a metallic coated substrate. The mural for the Denver International Airport, entitled La Memoria de Nuestra Tierra is a breakthrough in digital murals, printed digitally on a…

  9. Construcciones a base de tierra

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    Alvarez Alonso, Marina

    1984-11-01

    oriented towards dissipating possible prejudices which exist with regard to earthen constructions.Trabajo realizado y basado en las nuevas posibilidades de las construcciones con tierra, una vez considerado su interés en épocas anteriores y las nuevas posibilidades que ofrece ante la crítica impuesta por la crisis de la energía. Se hacen consideraciones sobre las necesidades de vivienda previstas hasta el año 2000 y otros parámetros que vuelven a ser importantes al confrontarlos económicamente con los materiales industrializados, sistemas de construcción, soluciones orientadas a los países en vías de desarrollo, etc. Continúa el trabajo con las primeras vías de experimentación práctica desarrolladas por el equipo de trabajo de viviendas de bajo coste orientadas a la búsqueda y promoción de recursos locales y abundantes como el material tierra, vías de experimentación que comienzan con el conocimiento por el equipo de técnicas y materiales durante el curso realizado en Ciadueña (Soria. Se describen aspectos técnicos del material tierra desarrollados paralelamente a la experiencia práctica inicial y orientada a la elección idónea de los componentes, una vez confrontada la información bibliográfica relacionada con el tema. Entre las consideraciones técnicas se llega a una exposición más exhaustiva sobre: 1 Las técnicas existentes: ladrillos de adobe, tierra apisonada (tapial, etc. 2 Porcentajes idóneos de los componentes para la elección de los materiales preferibles en cada una de las técnicas anteriores. 3 Consideraciones de los aspectos físicos y mecánicos de la maquinaria existente y en experimentación, así como de las posibilidades respecto a su puesta en obra, costes comparativos, etc. 4 Estudio de las posibilidades para mejorar las características del material tierra mediante diferentes técnicas de estabilización (compactación y correcciones granulométricas, estabilizantes fisicoquímicos, betunes, productos

  10. Bloque de tierra comprimida como material constructivo

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    Óscar Javier Gutiérrez Junco

    2011-07-01

    Full Text Available La construcción con tierra es poco usada en la actualidad debido a la falta de difusión e investigación, y a que es relacionada con la pobreza; por ende, se desaprovechan muchas de sus ventajas, como la abundancia demateria prima, la localización, la disponibilidad, el reciclaje, la producción sin consumo de energía (calorífica, el bajo costo y la resistencia –con un adecuado estudio del material tierra, de la estructuración y del suelo de fundación–; otras de sus ventajas son el aislamiento térmico y acústico. Con el paso del tiempo se han mejorado las técnicas constructivas con tierra, realizando estabilizaciones e implementando el uso de maquinaria y herramienta mecánica para elaborar bloques de tierra comprimida, y así facilitar el trabajo y obtener mayor rendimiento. Este artículo presenta la tierra como material constructivo, las técnicas o sistemas constructivos, los bloques de tierra comprimida (BTC y algunos ensayos realizados a estos bloques.

  11. Patterns of larval distribution and settlement of Concholepas concholepas (Bruguiere, 1789) (Gastropoda, Muricidae) in fjords and channels of southern Chile

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    MOLINET, CARLOS; ARÉVALO, ALEJANDRA; GONZÁLEZ, MARÍA TERESA; MORENO, CARLOS A.; ARATA, JAVIER; NIKLITSCHEK, EDWIN

    2005-01-01

    The distribution of Concholepas concholepas (Mollusca, Gastropoda, Muricidae) is limited to the coasts of Chile and southern Peru. Almost all studies of this gastropod have been carried out in open coastal systems, rather than the fjords and channels of southern Chile, despite the fact that this area represents ca. 95 % of the total coastline in this country. Although there is a large volume of background literature on C. concholepas, almost nothing is published about early larval development...

  12. A model for tides and currents in the English Channel and southern North Sea

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    Walters, Roy. A.

    The amplitude and phase of 11 tidal constituents for the English Channel and southern North Sea are calculated using a frequency domain, finite element model. The governing equations — the shallow water equations — are modifed such that sea level is calculated using an elliptic equation of the Helmholz type followed by a back-calculation of velocity using the primitive momentum equations. Triangular elements with linear basis functions are used. The modified form of the governing equations provides stable solutions with little numerical noise. In this field-scale test problem, the model was able to produce the details of the structure of 11 tidal constituents including O 1, K 1, M 2, S 2, N 2, K 2, M 4, MS 4, MN 4, M 6, and 2MS 6.

  13. Allegheny woodrat (Neotoma magister) use of rock drainage channels on reclaimed mines in southern West Virginia

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    Chamblin, H.D.; Wood, P.B.; Edwards, J.W.

    2004-01-01

    Allegheny woodrats (Neotoma magister) currently receive protected status throughout their range due to population declines. Threats associated with habitat fragmentation (e.g., introduced predators, disease, loss of connectivity among subpopulations and habitat loss) may explain why Allegheny woodrats are no longer found in many areas where they existed just 25 y ago. In southern West Virginia, surface coal mining is a major cause of forest fragmentation. Furthermore, mountaintop mining, the prevalent method in the region, results in a loss of rock outcrops and cliffs within forested areas, typical habitat of the Allegheny woodrat To determine the extent that Allegheny woodrats make use of reclaimed mine land, particularly rock drainages built during reclamation, we sampled 24 drainage channels on reclaimed surface mines in southern West Virginia, collected habitat data at each site and used logistic regression to identify habitat variables related to Allegheny woodrat presence. During 187 trap nights, 13 adult, 2 subadult and 8 juvenile Allegheny woodrats were captured at 13 of the 24 sites. Percent of rock as a groundcover and density of stems >15 cm diameter-at-breast-height (DBH) were related to Allegheny woodrat presence and were significantly greater at sites where Allegheny woodrats were present than absent. Sites where Allegheny woodrats were present differed substantially from other described habitats in West Virginia, though they may simulate boulder piles that occur naturally. Our findings suggest the need for additional research to examine the dynamics between Allegheny woodrat populations inhabiting rock outcrops in forests adjacent to mines and populations inhabiting constructed drainage channels on reclaimed mines. However, if Allegheny woodrats can use human-created habitat, our results will be useful to surface mine reclamation and to other mitigation efforts where rocky habitats are lost or disturbed.

  14. Floating marine debris in fjords, gulfs and channels of southern Chile.

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    Hinojosa, Iván A; Thiel, Martin

    2009-08-01

    Floating marine debris (FMD) is reported from all oceans. The bulk of FMD are plastics, which due to their longevity cause multiple negative impacts on wildlife and environment. Identifying the origins of FMD (land- or sea-based) is important to take the necessary steps to diminish their abundance. Using ship surveys we examined the abundance, composition and distribution of FMD during the years 2002-2005 in the fjords, gulfs and channels of southern Chile. Abundances of FMD were relatively high compared with other studies, ranging from 1 to 250 items km(-2). The majority (approximately 80%) of FMD was composed of styrofoam (expanded polystyrene), plastic bags and plastic fragments. Styrofoam, which is intensively used as flotation device by mussel farms, was very abundant in the northern region but rarely occurred in the southern region of the study area. Food sacks from salmon farms were also most common in the northern region, where approximately 85% of the total Chilean mussel and salmon harvest is produced. Plastic bags, which could be from land- or sea-based sources, were found throughout the entire study area. Our results indicate that sea-based activities (mussel farming and salmon aquaculture) are responsible for most FMD in the study area. In order to reduce FMDs in the environment, in addition to stronger legislation and identification of potential sources, we suggest environmental education programs and we encourage public participation (e.g. in beach surveys and clean-ups).

  15. Water Age Responses to Weather Conditions in a Hyper-Eutrophic Channel Reservoir in Southern China

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    Wei Du

    2016-08-01

    Full Text Available Channel reservoirs have the characteristics of both rivers and lakes, in which hydrodynamic conditions and the factors affecting the eutrophication process are complex and highly affected by weather conditions. Water age at any location in the reservoir is used as an indicator for describing the spatial and temporal variations of water exchange and nutrient transport. The hyper-eutrophic Changtan Reservoir (CTR in Southern China was investigated. Three weather conditions including wet, normal, and dry years were considered for assessing the response of water age by using the coupled watershed model Soil Water Assessment Tool (SWAT and the three-dimensional hydrodynamic model Environmental Fluid Hydrodynamic Code (EFDC. The results showed that the water age in CTR varied tremendously under different weather conditions. The averaged water ages at the downstream of CTR were 3 d, 60 d, and 110 d, respectively in the three typical wet, normal, and dry years. The highest water ages at the main tributary were >70 d, >100 d, and >200 d, respectively. The spatial distribution of water ages in the tributaries and the reservoir were mainly affected by precipitation. This paper provides useful information on water exchange and transport pathways in channel reservoir, which will be helpful in understanding nutrient dynamics for controlling algal blooms.

  16. Microplastic contamination in brown shrimp (Crangon crangon, Linnaeus 1758) from coastal waters of the Southern North Sea and Channel area

    NARCIS (Netherlands)

    Devriese, L.I.; van der Meulen, M.D.; Maes, T.; Bekaert, K.; Paul-Pont, I.; Frère, L.; Robbens, J.; Vethaak, A.D.

    2015-01-01

    This study assessed the capability of Crangon crangon (L.), an ecologically and commercially important crustacean, of consuming plastics as an opportunistic feeder. We therefore determined the microplastic content of shrimp in shallow water habitats of the Channel area and Southern part of the North

  17. Cultural Tourism In Fragile Institutional Contexts Project For Cultural Routes In Tierra Del Fuego

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    Eugenio Garcés Feliú

    2012-12-01

    Full Text Available The following paper presents a project of Cultural Routes designed for the Chilean Tierra del Fuego, linked to promoting tourism and boosting the economy, through the development of a specific high standard tourism offer, linked to its natural and cultural heritage, with the purpose of capturing the potential income generation for Chile. The project had as main goal to enhance the competitiveness of the tourism sector of special interests in Tierra del Fuego, a key sector of Southern Patagonia, through the dissemination and transfer of technologies and knowledge, acquired in over 10 years of research and projects, onto the territory and local agents. These Cultural Routes build an innovative offer, capable of structuring the diverse touristic resources and strengthening the basis for the development of a new stage of national and international tourism market, located on the southern extreme of Chile and America.

  18. Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

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    Leonardo Maltchik

    2011-12-01

    species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1 Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2 Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006. A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production. Rev. Biol. Trop. 59 (4: 1895-1914. Epub 2011 December 01.

  19. Aquilo que nomeia lei: a Madre Tierra

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    Cristina Zanella Rodrigues

    2017-11-01

    Full Text Available Este texto é sustentado teoricamente na Análise do Discurso de viés pêcheuxtiano e tem por corpus dois textos legais: a Ley de Derechos de La Madre Tierra (Ley nº 71/2010 e a Ley Marco de La Madre Tierra y Desarrollo Integral para Vivir Bien (Ley nº 300/2012 aprovadas na Bolívia. A irrupção da Madre Tierra como nome de lei faz ecoar, do lugar da voz dos povos originários, a memória cosmovisionária como discurso da resistência contra o silenciamento de uma história.  Ao atentar para o processo de subjetivação e os ruídos que este acontecimento pode ocasionar, há por objetivo analisar que efeitos de sentido e deslocamentos teóricos são produzidos a partir das formas de nomear, designar, referenciar, subjetivar a Madre Tierra na sua materialização linguístico-discursiva num texto legal. E como se podem operar os conceitos de falta, excesso e estranhamento (ERNST, 2009 no trabalho de análise do nome que nomeia uma lei.

  20. Ecologia de las lombrices de tierra

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    Grizelle Gonzalez

    2014-01-01

    De los organismos de suelo, las lombrices de tierra son las mas conocidas y a menudo son consideradas las mas importantes por su influencia en el funcionamiento de ecosistemas de suelo (Hendriz y Bohlen, 2002). Tienen un efecto significativo en la estructura del suelo, el ciclo de nutrimentos y ls productividad de las cosechas. En terminos de biomasa, generalmente...

  1. Los conjuntos palaciegos reales de las Tierras Bajas Mayas del sur: una evaluación de los datos arqueológicos e iconográficos Royal palace complexes in Southern Maya Lowlands: evaluating archaeological and iconographical data

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    Kai Delvendahl

    2010-01-01

    Full Text Available Este artículo va a trazar algunas conclusiones de una evaluación de los aspectos físicos, espaciales, funcionales y sociales de los conjuntos palaciegos reales tomando en cuenta evidencia arqueológica e iconográfica. Para el componente iconográfico se analizaron representaciones de escenas palaciegas pintadas sobre 87 vasijas cilíndricas de cerámica, mientras que para el componente arqueológico se evaluó información de conjuntos palaciegos bien documentados como el Grupo Palaciego M7 de Aguateca, el Palacio de Palenque, Los 27 Escalones de Kohunlich, el Grupo 10L-2 de Copán, la Acrópolis Central de Tikal y el Grupo Gran Acrópolis de Calakmul. Uno de los objetivos generales de este trabajo es proporcionar un ejemplo de cómo se puede capitalizar la información que las escenas palaciegas proveen (al comparar el corpus iconográfico con el dato arqueológico. Esto permitiría plantear ideas más ajustadas sobre los aspectos físicos, espaciales, funcionales y sociales de los conjuntos palaciegos del Clásico Tardío en el área maya.This paper will present some conclusions of an evaluation of the physical, spatial, functional, and social aspects of Classic Maya royal palaces taking into account archaeological and iconographic evidence. For the iconographic evaluation, the analysis examined representations of palace-like ambience on 87 cylindrical ceramic vases, while the archaeological information includes data from the better documented palace groups of the Southern Maya Lowlands, including the Palace Group M7 of Aguateca, the Palace of Palenque, Los 27 Escalones of Kohunlich, Group 10L-2 of Copan, the Central Acropolis of Tikal and the Grand Acropolis Group of Calakmul. In comparing the iconographic corpus with the archaeological evidence, one of the general objectives of this presentation is to provide an example of how the information inherent in the palace scenes can be capitalized to propose more adjusted ideas about the

  2. Modelling of channel transmission loss processes in semi-arid catchments of southern Africa using the Pitman Model

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    V. Mvandaba

    2018-05-01

    Full Text Available Water availability is one of the major societal issues facing the world. The ability to understand and quantify the impact of key hydrological processes, on the availability of water resources, is therefore integral to ensuring equitable and sustainable resource management. Channel transmission losses are an under-researched hydrological process that affects resource availability in many semi-arid regions such as the Limpopo River Basin in southern Africa, where the loss processes amount to approximately 30 % of the water balance. To improve the understanding of these loss processes and test the capability of modelling routines, three approaches using the Pitman model are applied to selected alluvial aquifer environments. The three approaches are an explicit transmission loss function, the use of a wetland function to represent channel-floodplain storage exchanges and the use of a dummy reservoir to represent floodplain storage and evapotranspiration losses. Results indicate that all three approaches are able to simulate channel transmission losses with differing impacts on the regional flows. A determination of which method best represents the channel transmission losses process requires further testing in a study area that has reliable observed historical records.

  3. A new genus and new species of felt scales (Homoptera: Coccinea: Eriococcidae from Tierra del Fuego (Chile

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    Ilya A. Gavrilov-Zimin

    2016-10-01

    Full Text Available Telmatococcus igniumterrae gen. nov. et sp. nov. is described and illustrated based on the material collected from a sphagnum bog in the extreme southern part of South America (Tierra del Fuego. The new monotypic genus differs from all known genera of Eriococcidae in having short cylindrical truncated setae of the anal apparatus and pouches with numerous quinquelocular pores near the anal apparatus. The habitat of the new taxon is characterized.

  4. Comprobaciones resistentes de elementos constructivos de tierra

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    Estrada, Enrique

    1986-11-01

    Full Text Available This work has the purpose to compare, by means of different tests on adobe bricks and masonry, the obtained resistant properties and those of other similar works carried out in countries having a wide tradition and knowledge about earth as construction material. Elements (adobe bricks and blocks have been tested to compression and bending, and masonry made of those elements to compression and diagonal compression.El presente trabajo pretende comparar, por medio de distintos ensayos sobre elementos y fábricas de mampostería de tierra, las propiedades resistentes obtenidas con las de otros trabajos similares realizados en países con dilatada tradición y conocimiento de la tierra como material de construcción. Se han ensayado elementos (adobes y bloques a compresión y flexotracción y fábricas formadas por conjuntos de los mismos a compresión y a compresión diagonal.

  5. Channel heads in mountain catchments subject to human impact - The Skrzyczne range in Southern Poland

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    Wrońska-Wałach, Dominika; Żelazny, Mirosław; Małek, Stanisław; Krakowian, Katarzyna; Dąbek, Natalia

    2018-05-01

    Channel heads in mountain catchments are increasingly influenced by human activity. The disturbance of mountain headwater areas in moderate latitudes by the clearing of trees and the associated logging, road building and hydrotechnical constructions contribute to changes in the water cycle and consequently may induce a change in channel head development. Here we examine channel heads in the Beskid Śląski Mts., one of the areas most affected by ecological disaster in the Polish Flysch Carpathians. An ecological disaster associated with the decline of spruce trees in the 1980s and 1990s caused a substantial decrease (of about 50%) in the land area occupied by spruce forest in the Beskid Śląski Mts. As a result, headwater areas were subject to multidirectional changes in the environment. The purpose of this paper is to determine the detailed characteristics of channel heads currently developing in the analyzed headwater areas, as well as to identify independent factors that affect the evolution of channel heads. Geomorphological mapping was conducted in 2012 in the vicinity of springs in the study area. One-way ANOVA was used to determine the significance of differences between mean values calculated for groups identified based on: i) geomorphologic processes (hollows with rock veneer - h, spring niches - sn, gullies - g), ii) location vs. transformation of channel heads (forested areas vs., deforested areas with road constructions). Principal component analysis (PCA) was used to determine the structure and general patterns associated with relationships between the parameters of a channel head and its contribution area, as well as to identify and interpret new (orthogonal) spaces defined using distinct factors. As far as we know, this kind of approach has been never applied before. A total of 80 channel heads surrounding 104 springs were surveyed close to the main ridge in the study area. A total of 14 morphometric parameters were taken into account in this study

  6. Tierra Caliente, Michoacán

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    C. I. Villa

    2008-01-01

    Full Text Available Los sistemas de producción ganaderos de la región de Tierra Caliente están vinculados al manejo agrosilvopastoril, aprovechando una amplia gama de recursos forrajeros naturales, siendo las familias quienes conducen la administración y aprovechamiento de dichos recursos. Se buscó definir las características, recursos forrajeros aprovechables e insumos alimenticios, estimando su calidad nutricional, con el fin de encontrar estrategias de alimentación de ganado que reduzcan al mínimo el uso de insumos externos al interior de las unidades productivas. Se trabajó en comunidades del municipio de Tuzantla, en la región de Tierra Caliente del estado de Michoacán. El método incluye la recolección de información por medio de encuestas aplicadas a productores campesinos, durante el ciclo productivo 2007. Se analizaron de 200 a 300 g de 41 muestras de alimentos con el método de Wendee, para analizar su composición química. Se encontró que para la región de Tierra Caliente existe un sistema de producción bovina de mediana escala, semi-estabulado y trashumante que, en promedio, tiene 250 a 260 ha y 86 cabezas de ganado destinado a la producción de carne y pie de cría, y que producen 9.2 l/vaca/día; con esta leche se elabora queso a razón de 1kg de queso por cada 10 litros de leche. Se identificó, también, el uso de seis ingredientes fundamentales que componen dos dietas básicas, cuya composición química detectada fue de 10.2- 13.9% (PC, 7.9-11.8% (FC, 62.8-67.9% (ELN, 1.4-5% (EE y 1.9-8.8% (cenizas. Por tanto, se concluye que los ganaderos cubren los requerimientos nutricionales con base en el alto uso de concentrados, dejando los forrajes para satisfacer las necesidades de consumo de su ganado. Por esto, se requiere establecer un sistema de balanceo de raciones que permita optimizar los recursos

  7. El recurso tierra en Costa Rica

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    Floria Bertsch

    2006-01-01

    Full Text Available En este artículo se presenta un análisis sistemático de la evolución del recurso tierra durante los últimos 10 años, desde diferentes perspectivas: las instituciones involucradas en su manejo, su uso actual y potencial, la actividad agropecuaria que sustenta dicho recurso a través de diferentes mundos agrícolas, y algunas otras opciones de agricultura sostenible que han surgido recientemente como es la agricultura orgánica. También se analiza el urbanismo, como aquella presión que efectúa la población sobre el recurso, y se discuten algunas alternativas de conservación planteadas a nivel nacional. Como conclusiones de la autora, en términos generales, el tema adolece de falta de información confiable desde hace 20 años, hay una clara tendencia al paso de la tierra de pequeños a más grandes propietarios y un incremento en la “peonización” a partir de la pérdida de la propiedad. El país se dirige hacia una clara dependencia de la compra en mercados extranjeros para la alimentación básica, a pesar de la existencia de nuevas opciones tecnológicas. Existen avances importantes en legislación pero aún están a nivel de papel y en términos urbanísticos, la presión social vence el ordenamiento territorial.

  8. Landslides control the spatial and temporal variation of channel width in southern Taiwan: implications for landscape evolution and cascading hazards in steep, tectonically active landscapes

    Science.gov (United States)

    Yanites, B.; Bregy, J. C.; Carlson, G.; Cataldo, K.; Holahan, M.; Johnston, G.; Mitchell, N. A.; Nelson, A.; Valenza, J.; Wanker, M.

    2017-12-01

    Intense precipitation or seismic events can generate clustered mass movement processes across a landscape. These rare events have significant impacts on the landscape, however, the rarity of such events leads to uncertainty in how these events impact the entire geomorphic system over a range of timescales. Taiwan is a steep, seismically active region and is highly prone to landslide and debris flows, especially when exposed to heavy rainfall events. Typhoon Morakot made landfall in Taiwan in August of 2009, delivering record-breaking rainfall and inducing more than 22,000 landslides in southern Taiwan. The topographic gradient in southern Taiwan leads to spatial variability in landslide susceptibility providing an opportunity to infer the long-term impact of landslides on channel morphology. The availability of pre and post typhoon imagery allows a quantitative reconstruction on the propagating impact of this event on channel width. The pre and post typhoon patterns of channel width to river and hillslope gradients in 20 basins in the study area reveal the importance of cascading hazards from landslides on landscape evolution. Prior to Typhoon Morakot, the river channels in the central part of the study area were about 3-10 times wider than the channels in the south. Aggradation and widening was also a maximum in these basins where hillslope gradients and channel steepness is high. The results further show that the narrowest channels are located where channel steepness is the lowest, an observation inconsistent with a detachment-limited model for river evolution. We infer this pattern is indicative of a strong role of sediment supply, and associated landslide events, on long-term channel evolution. These findings have implications across a range of spatial and temporal scales including understanding the cascade of hazards in steep landscapes and geomorphic interpretation of channel morphology.

  9. Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea)

    OpenAIRE

    Zaghden, H.; Tedetti, Marc; Sayadi, S.; Serbaji, M. M.; Elleuch, B.; Saliot, A.

    2017-01-01

    International audience; We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs)and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia,Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3–11.7%, 8–174 μg g−1 sed. dw and175–10,769 ng g−1 sed. dw, respectively. The lowest concentrations were recorded in the channel (mediumsand sediment) and the highest ones in the Sfax harbo...

  10. State of knowledge of the Corallinales (Rhodophyta of Tierra del Fuego and the Antarctic Peninsula

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    María Laura Mendoza

    1999-12-01

    Full Text Available Corallinales (Rhodophyta in Tierra del Fuego are abundant, with 9 genera, 17 species and 1 subspecies. Pseudolithophyllum with 1 species (P. fueguianum, which represents 35.8% of the coralline algae, is dominant. The genera Parahydrolithon with 4 species (P. consociatum, P. discoideum, P. falklandicum, P. subantarcticum and 20%, Lithothamnion with 3 species (Lt. heterocladum, Lt. rugosum, Lt. granuliferum and 17.5%, and Synarthrophyton with 3 species (S. neglectum, S. patena, S. schmitzii and 12% share are abundant. Clathromorphum with 4 species (Cl. annulatum, Cl. lemoineanum, Cl. obtectulum, Cl. Variabile and a share of 5.8%, and Mesophyllum with 1 species (M. fueguianum and a share of 4.9% are frequent. The remaining three genera, Bossiella with 1 subspecies (B. orbigniana ssp. orbigniana, Corallina with 2 species (C. elongata, C. officinalis (1.1%, and Titanoderna with 1 species (T. conspectum (1% are scarce. C. officinalis is a cosmopolitan, and the other geniculate corallines are found in both hemispheres, whereas the crustose coralline occur only in the southern hemisphere. The characteristic vertical distribution of the species in the intertidal and subtidal zone of Tierra del Fuego is given. The Corallinales in the Antarctic Region are poorly known and need further investigation.

  11. La temperatura del interior de la tierra

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    Eslava R. Jesús A.

    1993-10-01

    Full Text Available The problem of defining the Earth interior temperature is analized from Heat Flow observations and the acceptance of convection processes in the mantle. Comparative analyses of thermal, adiabatic, and melting point profiles, allow to obtain the optimum temperature profile, wich fits the seismic model of a liquid external core.

    EI problema de definir la temperatura del interior de la Tierra, se analiza a partir de las observaciones del flujo térmico y la aceptación de procesos de convección en el manto.

    Análisis comparativos de perfiles térmicos, adiabáticos y de puntos de fusión, permiten obtener un perfil óptimo de distribución de temperaturas, que además satisface la observación sísmica de un núcleo externo líquido.

  12. The perceived image of Tierra del Fuego (Argentina in travel stories published by “TravelPod”

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    Patricia Andrea Mosti

    2017-07-01

    environmental conditions, with inhospitable landscapes and, by all appearances, a pristine ecosystem. Together these things form a constitutive part the territorial identity of southern Patagonia. The cartography, the scientific expeditions, the religious missions, the journalism and the literature played an important role in the diffusion and permanency of these representations. In modern Western societies, companies have positioned the concept as a powerful tourist resource, capable of motivating travelers coming to Tierra del Fuego. The present communication proposes an approximation to the perceived image of Tierra del Fuego, according to tourists’ statements in trip blogs, taking these chronicles from sources posted on the site Travelpod. The aim is to examine the contents of the perceived image and to investigate the ways that the concept “End of the World” is resignified. The tourists’ testimonies appeal always to the idea of the End of the World; these representations can be condensed to two dimensions, the one linked to physical – geographical aspects and another that recreates symbolic contents. In the perceived images of Tierra del Fuego, there is an intermingling of the archaic, the legend and the distance, the impregnable vastness of the nature and the recollection of heroic expeditions.

  13. Fine-scale relief related to late holocene channel shifting within the floor of the upper Redondo Fan, offshore Southern California

    Science.gov (United States)

    Normark, W.R.; Paull, C.K.; Caress, D.W.; Ussler, W.; Sliter, R.

    2009-01-01

    Erosional and depositional bedforms have been imaged at outcrop scale in the upper Redondo Fan, in the San Pedro Basin of offshore Southern California in ???600 m water depths, using an Autonomous Underwater Vehicle developed by the Monterey Bay Aquarium Research Institute. The Autonomous Underwater Vehicle is equipped with multibeam and chirp sub-bottom sonars. Sampling and photographic images using the Monterey Bay Aquarium Research Institute Remotely Operated Vehicle Tiburon provide groundtruth for the Autonomous Underwater Vehicle survey. The 0??3 m vertical and 1??5 m lateral bathymetric resolution and 0??1 m sub-bottom profile resolution provide unprecedented detail of bedform morphology and structure. Multiple channels within the Redondo Fan have been active at different times during the Late Holocene (0 to 3000 yr bp). The currently active channel extending from Redondo Canyon makes an abrupt 90?? turn at the canyon mouth before resuming a south-easterly course along the east side of the Redondo Fan. This channel is floored by sand and characterized by small steps generally <1 m in relief, spaced 10 to 80 m in the down-channel direction. A broader channel complex lies along the western side of the fan valley that was last active more than 850 years ago. Two distinct trains of large scours, with widths ranging from tens to a few hundred metres and depths of 20 m, occur on the floor of the western channel complex, which has a thin mud drape. If observed in cross-section only, these large scours would probably be misidentified as the thalweg of an active channel. ?? 2009 The Authors. Journal compilation ?? 2009 International Association of Sedimentologists.

  14. Estado, mercado de tierra urbana e inundaciones en ciudades argentinas

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    Nora Clichevsky

    2006-01-01

    Full Text Available En este trabajo se presentan los resultados de una investigación sobre las relaciones que se establecen entre los mercados de tierra urbana y las inundaciones en ciudades argentinas, en el marco más amplio de la vulnerabilidad urbana. Se pretende despejar incógnitas acerca del papel jugado por el Estado como regulador del mercado en áreas urbanas con vulnerabilidad natural a la inundación y como constructor de defensas contra las inundaciones y acerca de los impactos que han tenido las inundaciones y las obras de defensa contra ellas sobre el mercado de tierra y, por lo tanto, sobre el acceso al suelo urbano por parte de los distintos sectores de la población.

  15. La Arquitectura de tierra es una herencia humana

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    Walter Domínguez Vega

    2010-01-01

    Full Text Available Se aborda el uso de la tierra en la restauración y conservación de la vivienda más antigua de Holguín. Se basa en la tendencia actual para la conservación sostenible de los bienes patrimoniales y culturales que orienta los materiales utilizados en los trabajos de intervención, se detiene sobre la relevancia y alcance histórico cultural del patrimonio edificado en la provincia de Holguín, describe las características constructivas de sus muros de embarrado los morteros utilizados y las dificultades para la conservación de ésta. Propone que se revitalice el uso de la tierra en construcciones de viviendas y menciona las investigaciones arqueológicas históricas en el interior y exterior de la casa.

  16. Saber tradicional, ética de la tierra y sustentabilidad

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    Heyd, Thomas

    2005-06-01

    Full Text Available This is the crucial moment to take on sustainable forms of life, and hence it is now of primary importance to adopt a land ethic that takes into account not only the use value but also the intrinsic value of the beings that make up our natural environment. In this essay I begin by focusing on the obstacles that the development of a land ethic has to face, obstacles that are due to limitations in knowledge and to mistaken assumptions. As a way to resolve these practical difficulties I first point out the existence of our natural inclinations toward the land and life. Furthermore, I propose that the traditional knowledge of those peoples that have lived for extended periods with their environments can serve us as models for the development of a culture of appreciation for the earth and its inhabitants.

    Éste ese! momento crucial para emprender formas de vida sustentables, por lo que resulta esencial adoptar una ética de la tierra que reconozca el valor intrínseco además del valor útil de los seres que pueblan nuestro medio ambiente natural. En este ensayo empiezo enfocando los obstáculos a que se enfrenta el desarrollo de una ética de la tierra, obstáculos que resultan ser el producto de conocimientos limitados y suposiciones equivocadas. En resolución de esas problemáticas prácticas apunto, primero, la existencia de inclinaciones naturales hacia la tierra y la vida. Además propongo que en el saber tradicional de los pueblos que han convivido mucho tiempo con sus espacios tenemos modelos de formas del conocer que nos pueden servir de modelo para llegar a desarrollar una cultura de aprecio de la tierra y de sus habitantes.

  17. EL SITIO HESHKAIA 35: NUEVOS DATOS SOBRE LA ARQUEOLOGÍA DE MOAT (TIERRA DEL FUEGO, ARGENTINA / Heshkaia 35 site: new data on the archaeology of Moat (Tierra del Fuego, Argentina

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    Atilio Francisco Zangrando

    2014-11-01

    Full Text Available arqueológicos recuperados en el sitio Heshkaia 35 (costa sur de Tierra del Fuego, Argentina. Este sitio se ubica en un ámbito costero en la sección media de la cuenca del río Moat y registra ocupaciones durante el Holoceno Tardío (ca. 800-500 AP. La diversidad tecnológica y el registro zooarqueológico señalan el desarrollo de actividades múltiples. Los artefactos líticos dominan el conjunto tecnológico. Los desechos líticos indican un fuerte énfasis hacia los estadios finales de talla, puesto de manifiesto en la baja presencia de artefactos con corteza y la elevada frecuencia de lascas de formatización y de reactivación de filos. El conjunto zooarqueológico se compone mayormente de restos óseos de guanacos. Los moluscos también habrían cumplido un rol significativo en la dieta. Restos óseos de mamíferos marinos, zorros, aves y peces están representados por frecuencias bajas. La composición artefactual y arqueofaunística estaría indicando que el aprovisionamiento de recursos se habría articulado principalmente desde el ámbito costero y no necesariamente en el mar. Se discuten las implicaciones de esta evidencia para las pautas conductuales de cazadores-recolectores en la costa sur de Tierra del Fuego. Palabras Clave: Arqueología de costas, Cazadores-recolectores, Tierra del Fuego, Holoceno Tardío   Abstract This paper presents and discusses the archaeological evidence from Heshkaia 35 site (southern coast of Tierra del Fuego, Argentina. This site is located in a coastal setting in the middle section of the Moat River Basin and records occupations during the Late Holocene (ca. 800-500 BP. Technological diversity and the zooarchaeological record point to the development of multiple activities. Lithic artifacts dominate the technological assemblage. Lithic debitage indicates a strong emphasis towards final stages of reduction, shown by the lower occurrence of artifacts with cortex and the high frequency resharpening

  18. Exploraciones Micológicas en Tierra del Fuego Mycological explorations in Tierra del Fuego

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    Irma J. Gamundí

    2007-07-01

    Full Text Available Se narran las expediciones marítimas y terrestres en Tierra del Fuego durante los siglos XIX y XX, desde el punto de vista de la exploración micológica cuyos resultados han sido vertidos en publicaciones, destacando las expediciones argentinas. Contiene mapas con las principales expediciones argentinas. Se hace una evaluación de la diversidad fúngica de acuerdo con los datos previamente analizados, comparando los registros de colección en ambos períodos que indican una duplicación del número total de taxones de 647 especies descriptas en el siglo XIX hasta 1269 en el siglo XX. Simultáneamente se observa una disminución del 50,4 % al 19.7 % en el número de especies nuevas publicadas. Se agrega una lista de coleccionistas y otra del estado de conservación ex situ de especies seleccionadas. Se hace un breve comentario sobre la conservación de hábitats colonizados por hongos que están perturbados por la explotación no sustentable de los recursos naturales.A narration of the leading maritime and terrestrial expeditions in Fuegia during the XIX and XX centuries is approached from the point of view of the mycological exploration and published results on the mycobiota, emphazising the Argentine expeditions. Maps with the itinerary of main Argentine expeditions is given. An evaluation of the fungal diversity according to the previous review is presented, comparing the fungal records during both periods that shows duplication of the total number of taxa from 647 species described in XIX century to 1269 in the XX century. Simultaneously there is a decrease from 50.4 % to 19.7 % in the number of new species published. A list of collectors and a table with the state of ex-situ conservation of selected species is presented. A brief comment is given on conservation of habitats supporting fungal population that are disturbed by unsustainable exploitation of natural resources.

  19. Adjustments in channel morphology due to land-use changes and check dam installation in mountain torrents of Calabria (Southern Italy)

    Science.gov (United States)

    Fortugno, Diego; Zema, Demetrio Antonio; Bombino, Giuseppe; Tamburino, Vincenzo; Quinonero Rubio, Juan Manuel; Boix-Fayos, Carolina

    2016-04-01

    In Mediterranean semi-arid conditions the geomorphic effects of land-use changes and check dam installation on active channel headwater morphology are not completely understood. In such environments, the availability of specific studies, which monitor channel adjustments as a response to reforestation and check dams over representative observation periods, could help develop new management strategies and erosion control measures. This investigation is an integrated approach assessing the adjustments of channel morphology in a typical torrent (Sant'Agata, Calabria, Southern Italy) after land-use changes (e.g. fire, reforestation, land abandonment) and check dam construction across a period of about 60 years (1955-2012). A statistical analysis of historical rainfall records, an analysis of land-use change in the catchment area and a geomorphological mapping of channel adjustments were carried out and combined with field surveys of bed surface grain-size over a 5-km reach including 14 check dams. The analysis of the historical rainfall records showed a slight decrease in the amount and erosivity of precipitation. Mapping of land-use changes highlighted a general increase of vegetal coverage on the slopes adjacent to the monitored reaches. Together with the check dam network installation, this increase could have induced a reduction in water and sediment supply. The different erosional and depositional forms and adjustments showed a general narrowing between consecutive check dams together with local modifications detected upstream (bed aggradation and cross section expansion together with low-flow realignments) and downstream (local incision) of the installed check dams. Changes in the torrent bends were also detected as a response to erosional and depositional processes with different intensities. The study highlighted: (i) the efficiency of check dams against the disrupting power of the most intense floods by stabilising the active channel; and (ii) the influence of

  20. Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)

    Science.gov (United States)

    Lang, Jörg; Brandes, Christian; Winsemann, Jutta

    2017-03-01

    Erosion and deposition by supercritical density flows can strongly impact the facies distribution and architecture of submarine fans. Field examples from coarse-grained channel-levée complexes from the Sandino Forearc Basin (southern Central America) show that cyclic-step and antidune deposits represent common sedimentary facies of these depositional systems and relate to the different stages of avulsion, bypass, levée construction and channel backfilling. During channel avulsion, large-scale scour-fill complexes (18 to 29 m deep, 18 to 25 m wide, 60 to > 120 m long) were incised by supercritical density flows. The multi-storey infill of the large-scale scour-fill complexes comprises amalgamated massive, normally coarse-tail graded or widely spaced subhorizontally stratified conglomerates and pebbly sandstones, interpreted as deposits of the hydraulic-jump zone of cyclic steps. The large-scale scour-fill complexes can be distinguished from small-scale channel fills based on the preservation of a steep upper margin and a coarse-grained infill comprising mainly amalgamated hydraulic-jump zone deposits. Channel fills include repeated successions deposited by cyclic steps with superimposed antidunes. The deposits of the hydraulic-jump zone of cyclic steps comprise regularly spaced scours (0.2 to 2.6 m deep, 0.8 to 23 m long) infilled by intraclast-rich conglomerates or pebbly sandstones, displaying normal coarse-tail grading or backsets. These deposits are laterally and vertically associated with subhorizontally stratified, low-angle cross-stratified or sinusoidally stratified sandstones and pebbly sandstones, which were deposited by antidunes on the stoss side of the cyclic steps during flow re-acceleration. The field examples indicate that so-called spaced stratified deposits may commonly represent antidune deposits with varying stratification styles controlled by the aggradation rate, grain-size distribution and amalgamation. The deposits of small-scale cyclic

  1. Seismically-induced soft-sediment deformation structures associated with the Magallanes-Fagnano Fault System (Isla Grande de Tierra del Fuego, Argentina)

    Science.gov (United States)

    Onorato, M. Romina; Perucca, Laura; Coronato, Andrea; Rabassa, Jorge; López, Ramiro

    2016-10-01

    In this paper, evidence of paleoearthquake-induced soft-sediment deformation structures associated with the Magallanes-Fagnano Fault System in the Isla Grande de Tierra del Fuego, southern Argentina, has been identified. Well-preserved soft-sediment deformation structures were found in a Holocene sequence of the Udaeta pond. These structures were analyzed in terms of their geometrical characteristics, deformation mechanism, driving force system and possible trigger agent. They were also grouped in different morphological types: sand dykes, convolute lamination, load structures and faulted soft-sediment deformation features. Udaeta, a small pond in Argentina Tierra del Fuego, is considered a Quaternary pull-apart basin related to the Magallanes-Fagnano Fault System. The recognition of these seismically-induced features is an essential tool for paleoseismic studies. Since the three main urban centers in the Tierra del Fuego province of Argentina (Ushuaia, Río Grande and Tolhuin) have undergone an explosive growth in recent years, the results of this study will hopefully contribute to future analyses of the seismic risk of the region.

  2. LUCHA POR LA TIERRA EN EL NORTE DE URUGUAY

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    Gabriel Oyhantçabal Benelli

    2011-12-01

    Full Text Available Este artículo analiza la trayectoria de la lucha por la tierra en Bella Unión, una región característica en Uruguay por la producción de caña de azúcar, a través de los movimientos de clase de sus principales protagonistas: los cortadores de caña sindicalizados en la Unión de Trabajadores Azucareros de Artigas (UTAA. El recorrido histórico hace énfasis en dos períodos históricos diferentes: 1961-1973 y 2005-presente. El primero va desde la fundación del sindicato hasta el golpe militar. Se da en un contexto de auge de la lucha de masas en Uruguay en el cual los trabajadores rurales se organizan en la UTAA levantando, entre otras, la bandera de la Reforma Agraria. El segundo período está marcado por la llegada al gobierno nacional del Frente Amplio, una coalición social-demócrata que reactiva la producción de caña de azúcar en Bella Unión. Este cambio supone una oportunidad para las luchas sociales que la UTAA aprovecha con ocupaciones de tierra favoreciendo un proceso de colonización para los trabajadores rurales. Sin embargo el acceso a la tierra genera nuevas contradicciones, y por tanto nuevos desafíos, por los cambios en la forma de subsunción del trabajo al capital.

  3. Construcción con tierra en el siglo XXI

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    Bestraten, S.

    2011-09-01

    Full Text Available Earthen construction during the 21rst century first decade has resurfaced worldwide as a sustainable, low environmental impact and great expressive material. The research and the number of projects has been increased related to the growth of the associations, institutions, universities and events surrounding this sector. These projects have managed to modernize the traditional techniques of building with earth in order to adapt them to today’s projecting needs, and have been widely recognized for its quality. The aim of this article is to provide a global view on earth construction internationally, providing technical data of its utilization in contemporary architectural projects.

    La construcción con tierra durante la primera década del siglo XXI ha resurgido en todo el mundo como un material con propiedades sostenibles, de bajo impacto ambiental y de gran capacidad expresiva. Se ha experimentado un crecimiento a nivel de proyectos e investigaciones sobre el material relacionado con el aumento de número de asociaciones, instituciones, universidades y eventos alrededor de este sector. Los proyectos actuales han sabido modernizar las técnicas tradicionales de construcción con tierra para adaptarlas a las necesidades proyectuales y constructivas, siendo ampliamente reconocidos por su calidad. El objetivo de este artículo es ofrecer una visión actual sobre la construcción con tierra a nivel internacional, aportando datos técnicos de su utilización en proyectos arquitectónicos contemporáneos.

  4. Sol, Tierra y Luna. Movimientos relativos y sus consecuencias

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    Sebastián Cardenete García

    2011-01-01

    Full Text Available Cuando se pregunta a los estudiantes por la causa de las estaciones suelen responder: "en verano estamos más próximos al Sol y en invierno estamos más lejos del Sol". La persistencia de esta idea y el hecho de su generalización entre los estudiantes y muchos adultos me ha inducido a escribir este artículo, en el cual se trata de explicar, de una forma clara y simple, el motivo de este y otros fenómenos debidos al movimiento de la Luna alrededor de la Tierra y de ésta alrededor del Sol.

  5. Regional disaster risk management strategies for food security: Probing Southern African Development Community channels for influencing national policy

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    Happy M. Tirivangasi

    2018-05-01

    Full Text Available Natural disasters and food insecurity are directly interconnected. Climate change related hazards such as floods, hurricanes, tsunamis, droughts and other risks can weaken food security and severely impact agricultural activities. Consequently, this has an impact on market access, trade, food supply, reduced income, increased food prices, decreased farm income and employment. Natural disasters create poverty, which in turn increases the prevalence of food insecurity and malnutrition. It is clear that disasters put food security at risk. The poorest people in the community are affected by food insecurity and disasters; hence, there is a need to be prepared as well as be in a position to manage disasters. Without serious efforts to address them, the risks of disasters will become an increasingly serious obstacle to sustainable development and the achievement of sustainable development goals, particularly goal number 2 ‘end hunger, achieve food security and improved nutrition and promote sustainable agriculture’. In recent years, countries in southern Africa have experienced an increase in the frequency, magnitude and impact of climate change–related hazards such as droughts, veld fire, depleting water resources and flood events. This research aims to reveal Southern African Development Community disaster risk management strategies for food security to see how they an influence and shape policy at the national level in southern Africa. Sustainable Livelihood approach was adopted as the main theoretical framework for the study. The qualitative Analysis is based largely on data from databases such as national reports, regional reports and empirical findings on the disaster management–sustainable development nexus.

  6. Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea).

    Science.gov (United States)

    Zaghden, Hatem; Tedetti, Marc; Sayadi, Sami; Serbaji, Mohamed Moncef; Elleuch, Boubaker; Saliot, Alain

    2017-04-15

    We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3-11.7%, 8-174μgg -1 sed.dw and 175-10,769ngg -1 sed.dw, respectively. The lowest concentrations were recorded in the channel (medium sand sediment) and the highest ones in the Sfax harbor (very fine sand sediment). AHs, PAHs and TOC were not correlated for most of the stations. TOC/N and δ 13 C values revealed a mixed origin of OM with both marine and terrestrial sources. Hydrocarbon molecular composition highlighted the dominance of petrogenic AHs and the presence of both petrogenic and pyrogenic PAHs, associated with petroleum products and combustion processes. This work underscores the complex distribution patterns and the multiple sources of OM and hydrocarbons in this highly anthropogenized coastal environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Stratigraphy and paleogeographic significance of a Late Pennsylvanian to Early Permian channeled slope sequence in the Darwin Basin, southern Darwin Hills, east-central California

    Science.gov (United States)

    Stevens, Calvin H.; Stone, Paul; Magginetti, Robert T.; Ritter, Scott M.

    2015-01-01

    The complex stratigraphy of late Paleozoic rocks in the southern Darwin Hills consists of regionally extensive Mississippian and Early to Middle Pennsylvanian rocks overlain by latest Pennsylvanian to Early Permian rocks, herein called the Darwin Hills sequence. Deposition of this latter sequence marked the beginning of the Darwin Basin. In Mississippian time, a carbonate platform prograded westward over slightly older slope deposits. In the Late Mississippian this platform was exposed to erosion and siliciclastic sediments were deposited. In Early to Middle Pennsylvanian time the area subsided, forming a west-facing ramp that was subjected to deformation and erosion in Middle or early Late Pennsylvanian time. Later this area was tilted westward and deep-water sediments were deposited on this slope. In latest Pennsylvanian to earliest Permian time, a major channel was cut through the older Pennsylvanian rocks and into the Upper Mississippian strata. This channel was gradually filled with increasingly finer grained, deep-water sediment as the area evolved into a basin floor by Early Permian (Sakmarian) time. Expansion of the Darwin Basin in Artinskian time led to a second phase of deposition represented by strata of the regionally extensive Darwin Canyon Formation. The geology in this small area thus documents tectonic events occurring during the early development of the Darwin Basin.

  8. Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea)

    International Nuclear Information System (INIS)

    Zaghden, Hatem; Tedetti, Marc; Sayadi, Sami; Serbaji, Mohamed Moncef; Elleuch, Boubaker; Saliot, Alain

    2017-01-01

    We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3–11.7%, 8–174 μg g −1 sed. dw and 175–10,769 ng g −1 sed. dw, respectively. The lowest concentrations were recorded in the channel (medium sand sediment) and the highest ones in the Sfax harbor (very fine sand sediment). AHs, PAHs and TOC were not correlated for most of the stations. TOC/N and δ 13 C values revealed a mixed origin of OM with both marine and terrestrial sources. Hydrocarbon molecular composition highlighted the dominance of petrogenic AHs and the presence of both petrogenic and pyrogenic PAHs, associated with petroleum products and combustion processes. This work underscores the complex distribution patterns and the multiple sources of OM and hydrocarbons in this highly anthropogenized coastal environment. - Highlights: • TOC, AHs and PAHs ranged 2–12%, 8–174 μg g −1 sed. dw and 175–10,769 ng g −1 sed. dw. • Lowest concentrations in the Sfax-Kerkennah channel, highest ones in the Sfax harbor • Decoupling between TOC, AH and PAH contents • TOC/N and δ 13 C values revealed a mixed origin of OM with marine and terrestrial sources. • Dominance of petrogenic AHs and presence of both petrogenic and pyrogenic PAHs

  9. Identifying potential differences in ontogentic ages between modern and archaeological Nacella deaurata shells, Tierra del Fuego, Argentina

    Science.gov (United States)

    Surge, D. M.; Godino, I. B. I.; Álvarez, M.; López, M. B. I.

    2017-12-01

    Patelloid limpet shells are common constituents of rocky shore habitats along the eastern Atlantic basin and are often found in archaeological shell middens. Nacella deaurata is an intertidal species found in the Magellanic Province along the southern tip of South America. Recent discoveries of archaeological shell middens in Tierra del Fuego, Argentina, identify N. deaurata as one of the abundant shells in these deposits. Preliminary observations reveal that modern N. deaurata shells achieve larger sizes compared to those found in the archaeological middens. Here, we provide preliminary data to test the hypothesis that the larger, modern specimens grow to older ontogenetic ages than the smaller archaeological specimens. Our results may provide insights into harvesting pressures on this species during the time when the archaeological sites were inhabited. Understanding their annual growth patterns also has important implications for generating oxygen isotope proxy data to reconstruct seasonal variation in sea surface temperature.

  10. Rock Magnetic Properties of Laguna Carmen (Tierra del Fuego, Argentina): Implications for Paleomagnetic Reconstruction

    Science.gov (United States)

    Gogorza, C. G.; Orgeira, M. J.; Ponce, F.; Fernández, M.; Laprida, C.; Coronato, A.

    2013-05-01

    We report preliminary results obtained from a multi-proxy analysis including paleomagnetic and rock-magnetic studies of two sediment cores of Laguna Carmen (53°40'60" S 68°19'0" W, ~83m asl) in the semiarid steppe in northern Tierra del Fuego island, Southernmost Patagonia, Argentina. Two short cores (115 cm) were sampled using a Livingstone piston corer during the 2011 southern fall. Sediments are massive green clays (115 to 70 cm depth) with irregularly spaced thin sandy strata and lens. Massive yellow clay with thin sandy strata continues up to 30 cm depth; from here up to 10 cm yellow massive clays domain. The topmost 10 cm are mixed yellow and green clays with fine sand. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM100mT) were performed and several associated parameters calculated (ARM100mT/k and SIRM/ ARM100mT). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. Additionally, we present results of magnetic parameters measured with vibrating sample magnetometer (VSM). The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is magnetite with the presence of hematite in very low percentages. This is the first paleomagnetic study performed in lakes located in the northern, semiarid fuegian steppe, where humid-dry cycles have been interpreted all along the Holocene from an aeolian paleosoil sequence (Orgeira et el, 2012). Comparison between paleomagnetic records of Laguna Carmen and results obtained in earlier studies carried out at Laguna Potrok Aike (Gogorza et al., 2012

  11. Effect of resource spatial correlation and hunter-fisher-gatherer mobility on social cooperation in Tierra del Fuego.

    Directory of Open Access Journals (Sweden)

    José Ignacio Santos

    Full Text Available This article presents an agent-based model designed to explore the development of cooperation in hunter-fisher-gatherer societies that face a dilemma of sharing an unpredictable resource that is randomly distributed in space. The model is a stylised abstraction of the Yamana society, which inhabited the channels and islands of the southernmost part of Tierra del Fuego (Argentina-Chile. According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital. The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation. We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

  12. Channels to Meet Foreign Partners and the Daily Life Adaptation in the Current Society of the Southern Thai Families Whose Members are married to Foreigners

    Directory of Open Access Journals (Sweden)

    Jirawitt Phannarat

    2016-09-01

    Full Text Available This qualitative research study used a phenomenological approach by studying from 20 families in southern Thailand whose members are married to foreigners (Western and Asian and live in various provinces in the south, including Songkhla, Surat Thani, Krabi, Trang, Phuket, Trang, and Chumphon. The data was analyzed by using an interpreting method. The inductive reasoning was performed and the results then were presented in a descriptive analysis. The study results reveal that the channels to meet foreign partners are through working in similar or the same occupations and working in the fields that are likely to meet the foreigners, such as teaching English language in high schools, teaching foreign languages, and studying abroad. The adaptation started early since when they began dating. The results also find that these days the society began to open wide about marriages between Thais and foreigners than in the past. For economic adaptation, most families are moderate to good standing. Due to current economic conditions, higher cost of living affect the family economic condition, they then agree to resolve the problem by reducing unnecessary costs within the family and maintain austerity budget to reduce unnecessary costs in order to have sufficient income for the family. For the cultural adaptation, Thai families whose members are married to foreigners uniquely have positive attitude and openness to ideas and able to exchange ideas with each other when they see things differently. The foreign spouses are also able to accept and learn the southern Thai culture, and at the same time the families are also open to learn the foreign culture.

  13. De vuelta a la concentración de tierras en el Perú

    OpenAIRE

    Arias Nieto, Custodio

    2014-01-01

    En este artículo presento el nuevo proceso de concentración de tierras en el Perú producido en los últimos quince años, teniendo como marco las normas legales del modelo neoliberal. Éstas han permitido la emergencia del latifundio en las mejores tierras que se encuentran en la costa peruana, cuya producción es principalmente para la exportación. Asimismo, las concesiones mineras, petroleras y forestales también vienen conduciendo a un nuevo tipo de concentración de tierras que degrada o destr...

  14. La arquitectura en tierra: Una alternativa para la construcción sostenible

    OpenAIRE

    Gloria Zuleta Roa

    2012-01-01

    La inquietud sobre la sostenibilidad de la arquitectura hecha con tierra se convierte en el punto de partida para escribir este artículo sobre el uso de la tierra como alternativa para realizar construcciones sostenibles. Se inicia con una mirada histórica del uso de la tierra como material de construcción en el mundo y en Colombia; sus características en relación con la sostenibilidad en los procesos constructivos y finalmente su contextualización dentro de las normas que regulan la construc...

  15. La arquitectura en tierra: Una alternativa para la construcción sostenible

    Directory of Open Access Journals (Sweden)

    Gloria Zuleta Roa

    2011-12-01

    Full Text Available La inquietud sobre la sostenibilidad de la arquitectura hecha con tierra se convierte en el punto de partida para escribir este artículo sobre el uso de la tierra como alternativa para realizar construcciones sostenibles. Se inicia con una mirada histórica del uso de la tierra como material de construcción en el mundo y en Colombia; sus características en relación con la sostenibilidad en los procesos constructivos y finalmente su contextualización dentro de las normas que regulan la construcción.

  16. Fire and vegetation history on Santa Rosa Island, Channel Islands, and long-term environmental change in southern California

    Science.gov (United States)

    Starratt, Scott W.; Pinter, N.; Anderson, Robert S.; Jass, R.B.

    2009-01-01

    The long-term history of vegetation and fire was investigated at two locations – Soledad Pond (275 m; from ca. 12 000 cal. a BP) and Abalone Rocks Marsh (0 m; from ca. 7000 cal. a BP) – on Santa Rosa Island, situated off the coast of southern California. A coastal conifer forest covered highlands of Santa Rosa during the last glacial, but by ca. 11 800 cal. a BP Pinus stands, coastal sage scrub and grassland replaced the forest as the climate warmed. The early Holocene became increasingly drier, particularly after ca. 9150 cal. a BP, as the pond dried frequently, and coastal sage scrub covered the nearby hillslopes. By ca. 6900 cal. a BP grasslands recovered at both sites. Pollen of wetland plants became prominent at Soledad Pond after ca. 4500 cal. a BP, and at Abalone Rocks Marsh after ca. 3465 cal. a BP. Diatoms suggest freshening of the Abalone Rocks Marsh somewhat later, probably by additional runoff from the highlands. Introduction of non-native species by ranchers occurred subsequent to AD 1850. Charcoal influx is high early in the record, but declines during the early Holocene when minimal biomass suggests extended drought. A general increase occurs after ca. 7000 cal. a BP, and especially after ca. 4500 cal. a BP. The Holocene pattern closely resembles population levels constructed from the archaeological record, and suggests a potential influence by humans on the fire regime of the islands, particularly during the late Holocene.

  17. Midiendo el diámetro de la Tierra

    Directory of Open Access Journals (Sweden)

    Sierra Porta, S.

    2008-09-01

    Full Text Available De distintas maneras se han ingeniado interesantes procedimientos para medir el radio de la tierra. Aquí se expone uno con la utilización de muchas técnicas sea formales o no para tal fín. El procedimiento es lo suficientemente sencillo como para que cualquier aficionado pueda repetirlo. No es un nuevo método, pero puede verse como pequeñas variaciones al mismo pudieran dar menos o más errores. El método precisa de tres piedras, una cuerda y una regla, de acuerdo con sus indicaciones, se debe contar también con un cerro desde donde podamos divisar el horizonte desde un lugar despejado en dos direcciones opuestas. La altura ideal de esta colina o promontorio seria de 30 a 300 metros sobre el nivel del mar (fácilmente podría ser desde un edificio; desde ella se divisara claramente una zona despejada. La motivación principal es proporcionar un marco para que los estudiantes en clase diserten acerca de la posibilidad de medier el tamaño de la tierra con argumentos muy sencillos y al alcance de todos. Se estimula de formulación de proyectos para investigación en el aula. Además se considera, en concordancia con las reformas de la educación y la globalización de las ciencias y los conocimientos, como estas actividades pueden acoger distintas disciplinas para un análisis óptimo de los resultados.

  18. Identification and functional expression of a glutamate- and avermectin-gated chloride channel from Caligus rogercresseyi, a southern Hemisphere sea louse affecting farmed fish.

    Directory of Open Access Journals (Sweden)

    Isabel Cornejo

    2014-09-01

    Full Text Available Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC(50 value of around 200 nM, being cooperative (n(H = 2 for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new

  19. Cultural tourism in fragile institutional contexts: project for cultural routes in Tierra del Fuego

    OpenAIRE

    Garcés Feliu, Eugenio

    2012-01-01

    The following paper presents a project of Cultural Routes designed for the Chilean Tierra del Fuego, linked to promoting tourism and boosting the economy, through the development of a specific high standard tourism offer, linked to its natural and cultural heritage, with the purpose of capturing the potential income generation for Chile. The project had as main goal to enhance the competitiveness of the tourism sector of special interests in Tierra del Fuego, a key sector of South...

  20. Fast hydrodynamic model for medium- and long-term dispersion in seawater in the English Channel and southern North Sea, qualitative and quantitative validation by radionuclide tracers

    Science.gov (United States)

    du Bois, P. Bailly; Dumas, F.

    The database for medium- and long-term model validation using 125Sb released by the La Hague reprocessing plant includes 1400 measurements performed between 1987 and 1994 in the English Channel and the North Sea and data for each release since 1982. Antimony-125 has a conservative behaviour in water masses over a period of several years. These data can be used qualitatively and quantitatively to compare the measured concentrations with the calculated ones and quantities of tracers. Tritium measurements are also available for model calibration. A two-dimensional hydrodynamic model has been developed to allow repetitive long-term simulations. This model uses a database of residual tidal currents calculated using the Lagrangian barycentric method [Salomon, J.C., Guéguéniat, P., Orbi, A., Baron, Y., 1988. A Lagrangian model for long-term tidally induced transport and mixing. Verification by artificial radionuclide concentrations. In: Guary, J.C., Guéguéniat, P., Pentreath, R.J. (Eds.), Radionuclides: A Tool for Oceanography, Cherbourg 1-5 June, 1987. Elsevier Applied Science Publishers, London, New York, pp. 384-394]. The area covered by the model includes the English Channel, the southern North Sea and the Irish Sea with a mesh size of 1 km. The main adjustment parameters of this model are the sources of wind data used and the calculation method for evaluating wind stress at the sea surface. With these parameters, the fluxes of radionuclides and water masses in the English Channel and the North Sea were balanced for the whole period of field measurements (1987-1994). The correlation factor between individual measurements in seawater and calculation results is 0.88 with an average error of ±54%, the error attributable to the measurement process being 15% on average. The mean flux through the Dover Strait is 126,000 m 3 s -1, close from the one obtained from previous studies [Salomon, J.C., Breton, M., Guéguéniat, P. 1993. Computed residual flow through the Dover

  1. El nuevo acaparamiento de tierras y las cambiantes dinamicas de la agricultura en el sur de Africa

    OpenAIRE

    Hall, Ruth

    2011-01-01

    El termino 'acaparamiento con fuerza en los ultimos anos para describir el renovado interes de las empresas por la tierra agraria, que se materializado en forma de cerramientos y privatizaciones de tierras a gran escala. Sin embargo, este termino esconde importantes diferencias respecto a la legalidad, la estructura y los resultados de los acuerdos comerciales sobre la tierra, de manera que desvia la atencion respecto al papel desempenado por las elites y los gobernos locales como socios, int...

  2. Acaparamiento de tierras y acumulación global capitalista: aspectos clave en América Latina.

    OpenAIRE

    Landívar, Natalia

    2013-01-01

    El análisis del acaparamiento de la tierra en América Latina está centrado básicamente en dos conceptos: la extranjerización y concentración de la tierra. Por un lado, en varios países como Argentina, Brasil, Uruguay, Paraguay y Guatemala la discusión se ha centrado en la extranjerización de la propiedad de la tierra. Esta se refiere a la adquisición de tierra por actores extranjeros, como gobiernos y corporaciones, así como de individuos, para una variedad de propósitos y de diferentes escal...

  3. Diversity of endosymbiotic Nostoc in Gunnera magellanica from Tierra del Fuego, Chile [corrected].

    Science.gov (United States)

    Fernández-Martínez, M A; de Los Ríos, A; Sancho, L G; Pérez-Ortega, S

    2013-08-01

    Global warming is causing ice retreat in glaciers worldwide, most visibly over the last few decades in some areas of the planet. One of the most affected areas is the region of Tierra del Fuego (southern South America). Vascular plant recolonisation of recently deglaciated areas in this region is initiated by Gunnera magellanica, which forms symbiotic associations with the cyanobacterial genus Nostoc, a trait that likely confers advantages in this colonisation process. This symbiotic association in the genus Gunnera is notable as it represents the only known symbiotic relationship between angiosperms and cyanobacteria. The aim of this work was to study the genetic diversity of the Nostoc symbionts in Gunnera at three different, nested scale levels: specimen, population and region. Three different genomic regions were examined in the study: a fragment of the small subunit ribosomal RNA gene (16S), the RuBisCO large subunit gene coupled with its promoter sequence and a chaperon-like protein (rbcLX) and the ribosomal internal transcribed spacer (ITS) region. The identity of Nostoc as the symbiont was confirmed in all the infected rhizome tissue analysed. Strains isolated in the present study were closely related to strains known to form symbioses with other organisms, such as lichen-forming fungi or bryophytes. We found 12 unique haplotypes in the 16S rRNA (small subunit) region analysis, 19 unique haplotypes in the ITS region analysis and 57 in the RuBisCO proteins region (rbcLX). No genetic variability was found among Nostoc symbionts within a single host plant while Nostoc populations among different host plants within a given sampling site revealed major differences. Noteworthy, interpopulation variation was also shown between recently deglaciated soils and more ancient ones, between eastern and western sites and between northern and southern slopes of Cordillera Darwin. The cell structure of the symbiotic relationship was observed with low-temperature scanning

  4. Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

    Science.gov (United States)

    Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

    2009-01-01

    Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

  5. Formas de tierra y clases de pendiente del departamento de Cusco: informe ejecutivo

    OpenAIRE

    Instituto Nacional de Recursos Naturales. Dirección General de Estudios y Proyectos

    2000-01-01

    Muestra la evaluación de las formas de tierra y clases de pendiente de la región sierra del departamento de Cusco. El objetivo principal es presentar de manera esquemática el conjunto de formas de tierra, clases de pendiente dominante, sus diferencias morfoclimáticas y evolutivas, así como la identificación de las principales acciones erosivas que actualmente puedan significar riesgos a las actividades humanas, o a coadyuvar al deterioro generalizado del medio. El documento ha sido elaborado ...

  6. Formas de tierra y clases de pendiente del departamento de Amazonas: informe ejecutivo

    OpenAIRE

    Instituto Nacional de Recursos Naturales. Dirección General de Estudios y Proyectos

    2000-01-01

    Muestra la evaluación de las formas de tierra y clases de pendiente de la región sierra del departamento de Amazonas. El objetivo principal es presentar de manera esquemática el conjunto de formas de tierra, clases de pendiente dominante, sus diferencias morfoclimáticas y evolutivas, así como la identificación de las principales acciones erosivas que actualmente puedan significar riesgos a las actividades humanas, o a coadyuvar al deterioro generalizado del medio. El documento ha sido elabora...

  7. Formas de tierra y clases de pendiente del departamento de Ica: informe ejecutivo

    OpenAIRE

    Instituto Nacional de Recursos Naturales. Dirección General de Estudios y Proyectos

    2000-01-01

    Abarca la evaluación de las formas de tierra y clases de pendiente de la región sierra del departamento de Ica. El objetivo principal es brindar de manera esquemática el conjunto de formas de tierra, clases de pendiente dominante, sus diferencias morfoclimáticas y evolutivas, así como la identificación de las principales acciones erosivas que actualmente puedan significar riesgos a las actividades humanas, o a coadyuvar al deterioro generalizado del medio. El documento ha sido elaborado en el...

  8. Formas de tierra y clases de pendiente del departamento de Arequipa: informe ejecutivo

    OpenAIRE

    Instituto Nacional de Recursos Naturales. Dirección General de Estudios y Proyectos

    1999-01-01

    Abarca la evaluación de las formas de tierra y clases de pendiente de la región sierra del departamento de Arequipa. El objetivo principal es mostrar de manera esquemática el conjunto de formas de tierra, clases de pendiente dominante, sus diferencias morfoclimáticas y evolutivas, así como la identificación de las principales acciones erosivas que actualmente puedan significar riesgos a las actividades humanas, o a coadyuvar al deterioro generalizado del medio. El documento ha sido elaborado ...

  9. The architecture of the extremes cultural landscapes in Tierra del Fuego

    OpenAIRE

    Garcés Feliú, Eugenio

    2010-01-01

    This paper aims to analyze the relevance of applying the notion of extreme cultural landscape to Tierra del Fuego, as a complementary category to those defined by Unesco. It states that in Chile there are anumber of territories at the margins –in the end, along the border– that have been built as landscapes, specifics and concretes, where the exploitation of natural resources has proved profitable and the building of human settlements as been allowed. This is the case of Tierra del Fuego, con...

  10. Un congreso de fisica estudia la composicion de las capas de la tierra

    CERN Multimedia

    2003-01-01

    "El Congreso de Internacional de Neutrinos, que ayer comenzo en el Jardin Botanico de Valencia, aborda, entre otros aspectos, la composicion y el perfil tomografico de las distintas capas de estratos del interior de la Tierra, segun informo a Efe el profesor Jose Furtado Valle" (1/2 page).

  11. La Carta de la Tierra en educación obligatoria desde una perspectiva internacional

    Directory of Open Access Journals (Sweden)

    Eva Francisca Hinojosa-Pareja

    2014-01-01

    Full Text Available La Carta de la Tierra surge como iniciativa de la sociedad civil en el año 2000. Desde su comienzo, es avalada por instituciones y organizaciones internacionales como la Unesco, que apoyó su contenido en 2003, e incorporada como instrumento educativo en proyectos de aplicación internacional como la “Década de la Educación para el Desarrollo Sostenible (2005-2014”, promovida por Naciones Unidas. Este artículo analiza distintas experiencias internacionales que utilizan la Carta de la Tierra como elemento de innovación en el ámbito de la educación obligatoria (infantil, primaria y secundaria. Una década después de la publicación de la Carta de la Tierra, y a través del análisis del contenido de estas experiencias, pretendemos hacer balance del camino recorrido, del grado de compromiso asumido desde el ámbito educativo, y favorecer el diálogo y la progresiva toma de conciencia sobre la Carta de la Tierra y su relevancia a nivel educativo.

  12. Relaciones entre la presencia de tierra y la supervivencia en serpientes de coral mantenidas en cautiverio

    OpenAIRE

    Reynoso, H.; Bucher, Enrique; Merlini, H. O.

    1985-01-01

    Teniendo en cuenta las particularidades de la especie Micrurus frontalis pyrrhocryptus (coral) en lo referente a su comportamiento semifosorial, hemos considerado conveniente relacionar distintos aspectos biológicos de la especie tales como longevidad, peso y producción de veneno, con la disponibilidad de tierra en recipientes y exposición a la luz.

  13. Los Takanas: el acceso a la tierra y los recursos naturales (1950-2003.

    Directory of Open Access Journals (Sweden)

    Zulema Lehm Ardaya

    2010-01-01

    uso comercial de diferentes especies naturales. El artículo discute la adaptación de los takanas a los desafíos y tendencias del uso de los recursos naturales en sistemas de acceso comunitario a la tierra.

  14. IMPACTOS DEL CAMBIO DE USO DE LA TIERRA EN LA MICROCUENCA MEMBRILLO, MANABÍ, ECUADOR

    Directory of Open Access Journals (Sweden)

    Alberto Hernández Jiménez

    2013-12-01

    Full Text Available El cambio de uso de la tierra, sobre todo el cambio de tierras forestales a tierras cultivadas, es una de las prácticas que mayor impacto ha tenido en la degradación de los suelos en el mundo y que ha provocado, en gran parte, la emisión de CO2 a la atmósfera. Por esto se hace necesario evaluar los cambios que han tenido las propiedades de los suelos por los diferentes ecosistemas, para de esta forma, tomar las medidas de mejoramiento y conservación de los suelos. En este trabajo, se estudia por primera vez, el cambio de algunas propiedades de los suelos de las partes medias y bajas de la microcuenca Membrillo (provincia de Manabí, Ecuador. Esta microcuenca presenta un relieve alomado, premontañoso, en la cual predominan bosques primarios y secundarios y plantaciones de cacao, pastizales y cultivos como el maíz en su parte baja. Los suelos son Feozems, Cambisoles y Fluvisoles y se presentan los resultados sobre cambios en sus características morfológicas (color, tipo de estructura, espesor de los horizontes A y B, las pérdidas de carbono orgánico y el cambio en la densidad aparente del suelo, provocado por el cambio de uso de la tierra.

  15. Review of Los nuevos amos de la tierra. Land Grabbing (Liberti, 2015

    Directory of Open Access Journals (Sweden)

    Germán Ignacio Ochoa

    2017-01-01

    Full Text Available Stefano Liberti. 2015. Los nuevos amos de la tierra. Land Grabbing. Bogotá: Penguin Random House Grupo Editorial. 250 pp. ISBN: 9788430616886. [Título original en italiano: Land Grabbing. Come il mercato delle terre crea il nuovo colonialismo].

  16. Sediment Dynamics Affecting the Threatened Santa Ana Sucker in the Highly-modified Santa Ana River and Inset Channel, Southern California, USA

    Science.gov (United States)

    Minear, J. T.; Wright, S. A.

    2015-12-01

    In this study, we investigate the sediment dynamics of the low-flow channel of the Santa Ana River that is formed by wastewater discharges and contains some of the last remaining habitat of the Santa Ana Sucker (Catostomus santaanae). The Santa Ana River is a highly-modified river draining the San Bernardino Mountains and Inland Empire metropolitan area east of Los Angeles. Home to over 4 million people, the watershed provides habitat for the federally-threatened Santa Ana Sucker, which presently reside within the mainstem Santa Ana River in a reach supported by year-round constant discharges from water treatment plants. The nearly constant low-flow wastewater discharges and infrequent runoff events create a small, approximately 8 m wide, inset channel within the approximately 300 m wide mainstem channel that is typically dry except for large flood flows. The sediment dynamics within the inset channel are characterized by constantly evolving bed substrate and sediment transport rates, and occasional channel avulsions. The sediment dynamics have large influence on the Sucker, which rely on coarse-substrate (gravel and cobble) for their food production. In WY 2013 through the present, we investigated the sediment dynamics of the inset channel using repeat bathymetric and substrate surveys, bedload sampling, and discharge measurements. We found two distinct phases of the inset channel behavior: 1. 'Reset' flows, where sediment-laden mainstem discharges from upstream runoff events result in sand deposition in the inset channel or avulse the inset channel onto previously dry riverbed; and 2. 'Winnowing' flows, whereby the sand within the inset channel is removed by clear-water low flows from the wastewater treatment plant discharges. Thus, in contrast to many regulated rivers where high flows are required to flush fine sediments from the bed (for example, downstream from dams), in the Santa Ana River the low flows from wastewater treatment plants serve as the flushing

  17. Capitalismo, crisis y naturaleza: Un análisis del acaparamiento de tierras dentro y desde el Sur Global

    OpenAIRE

    Mora, Sol

    2016-01-01

    El acaparamiento de tierras (land grabbing) refiere al proceso de adquisiciones a gran escala de tierras agrícolas en otros estados, desatado en el contexto de la convergencia de crisis internacionales —alimentaria, energética, financiera y climática— de 2008. Este artículo analiza las razones que convirtieron al acaparamiento de tierras en un fenómeno global, irreductible a la lógica Norte-Sur. Adicionalmente, indaga sus implicaciones sobre la posición internacional y definici...

  18. Patterns of larval distribution and settlement of Concholepas concholepas (Bruguiere, 1789) (Gastropoda, Muricidae) in fjords and channels of southern Chile Patrones de distribución de larvas y asentamiento de Concholepas concholepas (Bruguiere, 1789) (Gastropoda, Muricidae) en fiordos y canales del sur de Chile

    OpenAIRE

    CARLOS MOLINET; ALEJANDRA ARÉVALO; MARÍA TERESA GONZÁLEZ; CARLOS A. MORENO; JAVIER ARATA; EDWIN NIKLITSCHEK

    2005-01-01

    The distribution of Concholepas concholepas (Mollusca, Gastropoda, Muricidae) is limited to the coasts of Chile and southern Peru. Almost all studies of this gastropod have been carried out in open coastal systems, rather than the fjords and channels of southern Chile, despite the fact that this area represents ca. 95 % of the total coastline in this country. Although there is a large volume of background literature on C. concholepas, almost nothing is published about early larval development...

  19. The architecture of the extremes cultural landscapes in Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Eugenio Garcés Feliú

    2010-03-01

    Full Text Available This paper aims to analyze the relevance of applying the notion of extreme cultural landscape to Tierra del Fuego, as a complementary category to those defined by Unesco. It states that in Chile there are anumber of territories at the margins –in the end, along the border– that have been built as landscapes, specifics and concretes, where the exploitation of natural resources has proved profitable and the building of human settlements as been allowed. This is the case of Tierra del Fuego, considered as a landscape and as a resource, according to Gregotti and Sola-Morales, that has been formed by a human process on the geographical support of Tierra del Fuego, and owes its existence to a process that transformed this territory into a product, placed south of the ice fields, southeast of the Strait of Magellan, in the confines of America, between south latitudes 52 and 55 degrees. On the other hand, reading the area in terms of palimpsest, according to Corboz, brings out several layers to form the extreme landscapes in Tierra del Fuego, considering some key issues including: the nomination of Magellan as extreme and special area by Cideze; the geographical context of Tierra del Fuego, as the exceptional finish of Patagonia and the gateway to Antarctica; the important collection of narratives and maps bequeathed by European explorers who recognized it; the rich cultural legacy of the aboriginal sélknam; and the human settlements, which emerged at the late nineteenth century, setting some recognizable and typical landscapes. In this way, we argued that the extreme cultural landscapes in Tierra del Fuego have been formed in the manner of overlapping layers, like a palimpsest, in a construction that transcends the physical territory, to settle in the Western cultural fantasy as an imaginary of that remote boundary.

  20. Visión de la Concentración de la Tierra en América Latina

    NARCIS (Netherlands)

    C. Kay (Cristóbal)

    2012-01-01

    textabstractEn este breve artículo presento de manera muy general y esquemática algunos aspectos sobre la concentración de la tierra en América Latina. No pretendo hacer un análisis detallado y completo sobre la problemática de la tierra en la región. Pero espero poder resaltar algunos factores que

  1. Desplazamiento forzado y propiedad de la tierra en Antioquia, 1996-2004

    Directory of Open Access Journals (Sweden)

    Carlos Felipe Gaviria

    2007-06-01

    Full Text Available El desplazamiento forzoso es un fenómeno mundial que ha acompañado crisis políticas y sociales, relacionado, además, con el dominio del territorio por parte de los grupos inmersos en el conflicto. En Colombia, este fenómeno social se ha incrementado en los últimos años, junto con problemas agrarios, sociales y productivos. El objetivo de este artículo es analizar la relación existente entre el desplazamiento forzado y los procesos de concentración de la tierra en Antioquia entre 1996-2004. Se encuentra que existe una relación positiva entre propiedad de la tierra y desplazamiento forzado; en especial en Urabá y Oriente, subregiones antioqueñas con la producción agrícola más importante.

  2. Efecto de la impermeabilidad del Mucílago de Nopal en bloques de tierra comprimidos

    Directory of Open Access Journals (Sweden)

    Yolanda Guadalupe Aranda Jiménez

    2013-01-01

    Full Text Available La arquitectura de tierra1 es conocida desde hace siglos, sin embargo, actualmente es poco utilizada comparado con los sistemas constructivos comunes. Los bloques de tierra comprimido (BTC son elementos constructivos con un potencial elevado para ser utilizado en las construcciones de vivienda en México, principalmente por su similitud con los bloques tradicionales, siendo conveniente mejorar sus características a partir de un estabilizante. Se realizó el estudio de BTC estabilizados con cemento y una sustancia proveniente de las pencas maduras de nopal. Se encontró que al añadir mucílago de nopal se observa un incremento significativo de la resistencia a la compresión húmeda y seca, lo cual estar relacionado con una disminución de la porosidad; se ofrecen algunas relaciones del efecto del mucílago en el sólido analizado.

  3. Design of earth network in electric substations; Diseno de redes de tierra en subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Raull-Martin, J. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-09-01

    The purpose of this paper is to present a summarized version of the different types of construction of grounding systems, as web as their materials and formulas, which are necessary and useful for the design and building of a grounding network for medium to high voltage facilities. A description is also made of how to determine the electrical resistivity of subsoil layers with different physical characteristics. Several illustrative examples are also solved in the paper. [Spanish] El proposito de este articulo es presentar de manera resumida los diferentes tipos de construccion de los sistemas de tierra, asi como sus materiales y formulas, los cuales son necesarios y utiles para el diseno y edificacion de una red de tierra para instalaciones de mediana y alta tension. Se describe tambien la obtencion de las diferentes resistividades que presentan los terrenos con diversas caracteristicas fisicas. Asi mismo, se solucionan ejercicios ilustrativos a lo largo del articulo.

  4. Arquitectura de tierra -histórica y moderna- en Italia

    Directory of Open Access Journals (Sweden)

    Galdieri, Eugenio

    1986-02-01

    Full Text Available This work about the history of mud constructions in Italy -both of brick and formwork- gives an exposition of geographical zones where those are located, the kind of uses so as their possible historic origins, among which the author points the strong connections with Spanish adobe constructions, both in Cagliars (Aragonese influence and in Oristano (Castilian influence.El trabajo de carácter histórico sobre las construcciones con tierra en Italia, tanto de adobe como de tapial presenta una panorámica de las zonas geográficas en las que se encuentran enclavadas, así como el tipo de usos y posibles orígenes históricos, entre los que el autor señala los fuertes vínculos con las construcciones de tierra españolas, tanto en Cagliaria (influencia aragonesa como en Oristano (influencia castellana.

  5. Bryophyte diversity patterns in flooded and tierra firme forests in the Araracuara Region, Colombian Amazonia

    OpenAIRE

    Benavides, Juan C.; Idarraga, Alvaro; Alvarez, Esteban

    2004-01-01

    We investigated patterns of bryophyte species richness and composition in two forest types of Colombian Amazonia, non-flooded tierra firme forest and floodplain forest of the Caquetá River. A total of 109 bryophyte species were recorded from 14 0.2 ha plots. Bryophyte life forms and habitats were analyzed, including the canopy and epiphylls. Bryophyte species did not show significant differences between landscapes but mosses and liverworts were different and with opposite responses balancing ...

  6. La adecuación de tierras en el departamento de Antioquia.

    Directory of Open Access Journals (Sweden)

    Arango T. Julio César

    1999-06-01

    Full Text Available Los programas estatales de adecuación de tierras en Colombia comenzaron a partir de la década del 50, durante la cual se emprendió la construcción de infraestructuras básicas para el riego, el drenaje y el control de inundaciones. Las inversiones efectuadas por distintas entidades que en el país han tenido que ver con el Sector de la Adecuación de Tierras han sido cuantiosas y con ellas, se beneficiaron durante muchos años, los agricultores situados en distintas zonas planas de los departamentos del Tolima, Boyacá, Magdalena, Valle del Cauca entre otros. Antioquia durante este mismo tiempo, no se favoreció de esos recursos, por la carencia de políticas estatales en el Sector de la Adecuación de Tierras, solamente a partir de 1983, con el montaje por parte del HIMAT del Programa Nacional de Pequeña Irrigación, comienzan a solucionarse los problemas de manejo del agua para el riego de los cultivos en distintas veredas de Antioquia. Hoy se dispone de 29 distritos de riego en pequeña escala, los cuales corresponden a una superficie total de 3.759 ha, en las cuales, se benefician 1.510 familias campesinas.

  7. Mass balance evolution of Martial Este Glacier, Tierra del Fuego (Argentina for the period 1960–2099

    Directory of Open Access Journals (Sweden)

    M. Buttstädt

    2009-12-01

    Full Text Available The Martial Este Glacier in southern Tierra del Fuego was studied in order to estimate the surface mass balance from 1960 until 2099. For this reason a degree-day model was calibrated. Air temperature and precipitation data obtained from 3 weather stations as well as glaciological measurements were applied. The model was driven using a vertical air temperature gradient of 0.69 K/100 m, a degree-day factor for snow of 4.7 mm w.e. K−1 day−1, a degree-day factor for ice of 9.4 mm w.e. K−1 day−1 and a precipitation gradient of 22%/100 m. For the purpose of surface mass balance reconstruction for the time period 1960 until 2006 a winter vertical air temperature gradient of 0.57 K/100 m and a summer vertical air temperature gradient of 0.71 K/100 m were added as well as a digital terrain model. The key finding is an almost continuous negative mass balance of −772 mm w.e. a−1 throughout this period. While the calculation of the mass balance for the period 1960–2006 is based on instrumental records, the mass balance for the years 2007 until 2099 was estimated based on the IPCC SRES A2-scenario. To accomplish this estimation, the dataset of the global climate model HadCM3 was statistically downscaled to fit local conditions at Martial Este Glacier. Subsequently, the downscaled air temperature and precipitation were applied to a volume-area scaling glacier change model. Findings reveal an enduring deglaciation resulting in a surface area reduction of nearly 93% until 2099. This implicates that the Martial Este Glacier might be melted off at the beginning of the 22nd century.

  8. Características y Problemas de Tenencia de la Tierra en el Sector Agropecuario Colombiano

    Directory of Open Access Journals (Sweden)

    Tobón Restrepo Arturo

    1964-12-01

    Full Text Available El término “Tenencia” es bastante amplio, pues relaciona la posesión física de un bien sin importar la legitimidad en el dominio de él. En cuanto a la posesión nuestro Código Civil (3 estipula: "La posesión es la tenencia de una cosa determinada con ánimo de señor o dueño, sea que el dueño o el que se la da por tal tenga la cosa por sí misma, o por otra persona que la tenga en lugar y a nombre de él". Para nuestro fin concretemos únicamente en el aspecto de la tierra. El presente estudio se encauza hacia la economía agrícola y la administración rural, más que al aspecto jurídico de la tenencia de la tierra Es bien sabido que en el sistema económico cada factor de producción encierra numerosas especificaciones, además el uso de uno de ellos .implica la combinación en el uso de los demás. Es por ello que al hablar de solución a un problema no se debe decir que se llegue a salvar los obstáculos que impiden el desarrollo económico en el panorama nacional ya que la tenencia de la tierra es un rubro dentro de los muchos con que cuenta el factor tierra. Es claro, que no podría separarse por completo el concepto de tenencia de la tierra de las demás circunstancias de carácter económico en todos sus aspectos; pero las consideraciones que se harán en el transcurso del presente trabajo serán tomadas con cierta tendencia individualista hacia el tema en mención.

  9. TECNOLOGÍAS DE TRATAMIENTO PARA LA TIERRA FULLER CONTAMINADA CON ACEITE DIELÉCTRICO

    Directory of Open Access Journals (Sweden)

    Óscar Darío Beltrán Pérez

    Full Text Available Desde hace algunos años en Colombia se vienen implementando convenios y normas para el adecuado manejo y disposición final de los residuos peligrosos, debido a que la cantidad generada cada vez va en aumento y al impacto adverso que estos residuos presentan en el ser humano y el medio ambiente. La tierra Fuller es un material inorgánico adsorbente (mineral de aluminosilicatos principalmente, utilizado en la industria eléctrica para la regeneración del aceite dieléctrico, un derivado del petróleo empleado como aislante eléctrico y térmico en los transformadores de potencia. Después del proceso de regeneración del aceite, el contenido de hidrocarburos del tipo poliaromáticos (o los PAH por sus siglas en inglés que presenta la tierra Fuller la convierten en un residuo peligroso que requiere de un adecuado tratamiento, para que reduzca su contaminación y permita su reutilización o segura disposición final en un relleno sanitario. Por esto, en este artículo se revisan las tecnologías disponibles para el tratamiento de este tipo de residuo peligroso (tierra Fuller contaminada con aceite dieléctrico, dividiendo los tratamientos en dos corrientes, las tecnologías fisicoquímicas y las biológicas, explorando las alternativas más apropiadas y eficientes para su tratamiento. La escasa información acerca de los tratamientos existentes para la tierra Fuller contaminada con aceite dieléctrico han orientado la revisión en términos de las tecnologías implementadas en suelos contaminados con hidrocarburos siendo válida la analogía debido a las similares características físicas que presenta la tierra Fuller con respecto a un suelo de bajo contenido de carbono.

  10. Abundancia y Biomasa de Lombrices de Tierra en dos Ecosistemas Intervenidos del Bosque Trópica l Húmedo, Bluefields Las lombrices de tierra son el intestino de la tierra Gilbert White, 1789.

    Directory of Open Access Journals (Sweden)

    Gladys Luna

    2012-09-01

    Full Text Available Muchos estudios han demostrado que las lombrices de tierra (Anelidae son el componente más abundante de la macrofauna del suelo y desempeñan funciones ecológicas dentro de él.El objetivo fue evaluar la abundancia y biomasa de lombrices de tierra en dos hábitats del bosque tropical húmedo con diferentes usos de suelo en la ciudad de Bluefields, Región Autónoma Atlántico Sur (RAAS. En cada hábitat se seleccionaron dos micro-hábitats: uno con sombra y otro sin sombra y en cada uno se delimitaron tres subparcelas de 1pie2 cada una, y una profundidad de 10 cm, ubicadas al azar y a una distancia mínima de 15 m entre sí.Cada muestra de suelo se tamizó y se extrajeron, se midieron y se pesaron los individuos por subparcela. El número de lombrices registradas fue mayor en el hábitat de área reforestada que en el hábitat de bosque, pero ocurrió lo contrario con respecto al tamaño promedio de los individuos.La mayor disponibilidad de materia orgánica en el bosque puede explicar el mayor tamaño de los individuos en este sitio.En aquellos suelos que han sufrido alteraciones antrópicas, como en el campus universitario, las comunidades de lombrices han experimentado cambios extremos denotando así una mala salud; sin embargo, estas comunidades se están recuperando, especialmente en los microhabitats con sombra.

  11. La función económica social: un medio para el acceso y conservación de la tenencia de la tierra en Bolivia

    OpenAIRE

    Bejarano Torrejón, Hugo

    2017-01-01

    La tenencia de la tierra constituye un factor importante en la estructura productiva y de desarrollo de los Estados, por cuanto el equilibrio entre las fuerzas productivas denominadas tierra y hombre constituyen la base para un desarrollo armónico del área rural lo cual impacta también en el desarrollo del mismo Estado; así la tenencia de la tierra es la relación entre la cantidad de tierra existente en un determinado Estado y su población, mediando su ocupación o posesión. El principio ag...

  12. Epidemiología de las lesiones por mordedura de perro en Tierra del Fuego, Argentina Epidemiology of dog bite lesions in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Fabián Zanini

    2008-02-01

    Full Text Available La convivencia del hombre y el perro ha resultado en beneficios mutuos durante miles de años, si bien en el último tiempo han surgido una serie de inconvenientes donde las lesiones por mordeduras ocupan un lugar destacado. El objetivo del presente trabajo fue describir las características epidemiológicas de las lesiones por mordedura de perro ocurridas a lo largo de un año en Tierra del Fuego. Se realizó un estudio observacional descriptivo, transversal, de los pacientes que ingresaron con lesiones por mordedura de perro al Servicio de Guardia Clínica y Pediátrica de los Hospitales y Centros de Salud desde el 1/3/05 hasta el 1/3/06. Se confeccionaron 382 planillas. El 49.5% fueron niños resultando más afectado el grupo de 5-9 años (44.4%; IC95% 37.2-51.8. En adultos correspondió al grupo de 15-24 años (29.5%; IC95% 23.2-36.5. Se registraron más lesiones en varones (57.6% que en mujeres (42.4% (x² = 8.6, p= 0.003. En los meses primavera y verano se registró el 56.5% de las lesiones, en la vía pública el 72.8% de ellas. Los perros de tamaño grande causaron el 49.7% (IC95% 44.6-54.9 de las lesiones. El 89.8% de los ataques fueron causados por perros ajenos. El 55.8% (IC95% 50.6-60.8 se registró en miembros inferiores y el 11% (IC95% 8.1-14.7 en cabeza y cuello. Los datos obtenidos demuestran que en Tierra del Fuego las lesiones por mordedura de perro afectan en forma permanente la salud e impactan en la calidad de vida de la población.The coexistence between man and dog has resulted in mutual benefits during thousands of years, nevertheless some problems have recently arisen where bite injuries have an important role. The aim of this work was to describe the epidemiological characteristics of dog bite lesions which occurred during a year in Tierra del Fuego. A descriptive observational, transversal study of patients who were admitted with dog bite injuries to clinic and pediatric emergency services of hospitals and health

  13. Habitar en Tierras Secas: La Tierra Cruda como vehículo de habitabilidad en el territorio no irrigado del norte de la Provincia de Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Virginia Miranda Gassull

    2015-12-01

    Full Text Available El territorio no irrigado del norte de la provincia de Mendoza es un vasto espacio sin acceso al bien hídrico, donde habita dispersa una población campesina de identidad originaria Huarpe. Habitar en este territorio ha sido desde hace siglos un desafío tanto al clima/ambiente como a condiciones sociopolíticas. Por lo tanto, el hábitat en tierras secas presenta particulares características respecto a su forma de gestión (autónoma, a su adaptación al ambiente y al uso de la técnica constructiva con tierra cruda: adobe. El objetivo a desarrollar aquí se sustenta en el uso actual del adobe, concebido como un vehículo que facilita la autoconstrucción y autoproducción de soluciones habitacionales en poblaciones desposeídas, ajustando su vivienda a las implicancias de un territorio árido y a un largo proceso de vulnerabilidad de derechos. Este artículo aproxima los primeros resultados de los relevamientos realizados sobre la técnica constructiva del adobe (a través de técnicas cuantitativas: encuesta y muestras in situ y las características propias del hábitat social de la población originaria Huarpe, a partir de la técnica de la observación participante.

  14. Seismic structure from multi-channel seismic reflection and wide-angle data of Transect 0E in the Southern Gulf of California

    Science.gov (United States)

    Paramo, P.; Holbrook, W.; Brown, H.; Lizarralde, D.; Fletcher, J.; Umhoefer, P.; Kent, G.; Harding, A.; Gonzalez, A.; Axen, G.

    2005-12-01

    We present a velocity model from wide-angle data along with coincident prestack depth migration sections from seismic reflection data collected in the southern Gulf of California. Transect 0E runs NE to SW from the hills of Sierra Madre in mainland Mexico near Mazatlan to approximately 115 km into Gulf of California waters. Wide-angle data were recorded by 9 ocean bottom seismometers, deployed by the R/V New Horizon and 10 Reftek seismometers located along onshore extension of the transect. The average spacing for the OBS and Refteks is ~12 km and shots were fired from the R/V Maurice Ewing at 150 m intervals. Transect 0E crosses what it is believed to be extended continental crust and lies in the initial direction of extension characteristic of the proto-gulf. Preliminary results from the velocity model show upper crustal velocities of 6.1-6.3 km/s and lower crustal velocities of 6.7-7.0 km/s along the entire transect. Seismic velocities and crustal thicknesses observed along transect 0E are characteristic of non-volcanic margins.

  15. Mapa de usos potenciales de la tierra de Galicia. Una perspectiva arqueológica

    Directory of Open Access Journals (Sweden)

    Currás Refojos, Brais X.

    2014-06-01

    Full Text Available A digital version of the map of potential land use of Galicia is here presented, adapted to a reclassification of three types of potential land use, established using historical criteria. An analytical procedure is developed to select the land-types and the system used for their digitalisation. In the final part the map is used to critically revise the possibilities of using this record for territorial characterisation in archaeological research.La cartografía de usos potenciales de la tierra es una herramienta de gran utilidad en el estudio de las formas de poblamiento y su relación con la explotación de los recursos agrícolas desde el enfoque de la arqueología del paisaje. La digitalización de esta información permite su aplicación sistemática en el análisis del territorio mediante SIG. En este trabajo se presenta el Mapa de usos potenciales de la tierra de Galicia, reclasificado en tres tipos establecidos en función de criterios históricos. Se muestra el procedimiento analítico desarrollado para la selección y clasificación de los tipos de tierra y su sistema de digitalización. Se examina la validez de esta fuente para la investigación arqueológica de las formas agrícolas en la antigu.edad desde el punto de vista del análisis del territorio y se ofrece una visión crítica sobre sus ventajas y limitaciones.

  16. [Tierra del Fuego: the scientific-political construction of exclusion and counter-image of the ideal city dweller].

    Science.gov (United States)

    Nacach, Gabriela

    2012-01-01

    Due to its late incorporation into the national State, the social, economic and political setting of the Argentine province Tierra del Fuego differed from that of the rest of the national territory. In the construction of dependent otherness, objectifications and representations were imposed by state-related and non-state-related institutions, among other agencies. In this context, the Salesian mission of La Candelaria and Ushuaia's Jail for recidivists stand out as spaces in which biopolitics was concretised. The native population and criminals in Tierra del Fuego were those to be subjugated. The thesis of the extinction of the Indian and the simultaneous exaltation of the criminal as the subject of progress identified the scientific and political mechanisms by which the exclusion of certain social groups (Tierra del Fuego's indigenous population) and the inclusion of others (criminals) were regulated.

  17. Las normativas de construcción con tierra en el mundo

    Directory of Open Access Journals (Sweden)

    Cid, J.

    2011-09-01

    Full Text Available For centuries, earth has been used as a construction material. Nevertheless, the normative in this matter is very scattered, and in the most developed countries, carrying out a construction with this material implies a variety of technical and legal problems. This article analyzes, in an international level, the normative panorama about constructions with earth, analyzing fifty five standards and regulations of countries all around the five continents; these represent the state of art that normalizes the earth as a construction material. It is a study indexed on the actual procedures and regulations developed by the national organisms of normalization or correspondent authorities. The standards and the organisms that produce them appear, analyzing the structure and the content of each one. We have studied and analyzed the most relevant aspects, such as stabilization, soil selections, the requisites of the products and the existent test, comparing the diverse normative. The knowledge from this study could be very useful for the development of future standards and as a reference for architects and engineers that work with earth.

    La tierra ha sido utilizada como material de construcción desde hace siglos. No obstante, la normativa al respecto está muy dispersa, y en la mayoría de países desarrollados surgen numerosos problemas técnicos y legales para llevar a cabo una construcción con este material. Este artículo estudia el panorama normativo para las construcciones con tierra cruda a nivel internacional, analizando cincuenta y cinco normas y reglamentos de países repartidos por los cinco continentes, que representan el estado del arte de la normalización de la tierra cruda como material de construcción. Es un estudio referenciado sobre las normas y reglamentos vigentes desarrollados por los organismos nacionales de normalización o autoridades correspondientes. Se presentan las normativas y los organismos que las emiten

  18. Modelo de levantamiento de informacion fisica catastral para el Instituto Nacional de Tierras, oficina regional Trujillo

    OpenAIRE

    Castellanos, Víctor

    2011-01-01

    Se identificó la metodología utilizada para el catastro físico de los Asentamientos Campesinos del Estado Trujillo, durante la vigencia del Instituto Agrario Nacional, y la existente actualmente con el Instituto Nacional de Tierras, Ofi cina Regional Trujillo. La evaluación de esta información determinó la propuesta de un modelo de levantamiento con fi nes de densifi cación de redes geodésicas utilizando tecnología satelital GPS, que facilite la actualización catastral de los pred...

  19. La industria textil en Tierra de Campos afines de la Edad Media

    Directory of Open Access Journals (Sweden)

    Hipólito Rafael OLIVA HERRER

    2009-12-01

    Full Text Available RESUMEN: El presente articulo trata de analizar el desarrollo de la industria textil rural en la región de Tierra de Campos, en torno al tradicional centro de producción textil de Palencia, a fines del XV y comienzos del XVI. La producción en el entorno rural conoció un amplio desarrollo basado en la producción de paños de calidad media-baja destinados al consumo interno, y dio lugar a formas organizativas complejas que se constituyeron en una alternativa frente al sistema gremial imperante en la urbe palentina, implicando intereses de un amplio espectro de grupos sociales.ABSTRACT: The present article aims to analyze the spreading of the rural textile industry in the region of Tierra de Campos in the late fifteenth and the early sixteenth centuries, around the traditional productive centre of Palencia. Here rural clothing experienced an important development based on the production of low and medium quality cloth under a putting-out system directed to interregional trade. The interests around rural industry involved a wide range of social groups, giving rise to complex organization forms and arising as an alternative to the traditional gudd stmcture.

  20. Ecohydrological features of some contrasting mires in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    A. Grootjans

    2010-01-01

    Full Text Available In November 2005, Tierra del Fuego (Argentina hosted the biennial conference and field excursion of the International Mire Conservation Group (IMCG. The group considered the vegetation, hydrology, peat stratigraphy and possible management options for about 20 mires which were visited during a seven-day excursion. We report here some field observations and measurements of electrical conductivity (EC25 in five mires which have been selected to encompass the most important ecohydrological features of the mires of Tierra del Fuego. Existing and new data on landscape topography and vegetation were combined in three-dimensional drawings. These drawings are actually conceptual models which could underpin further ecohydrological research, and proved to be very useful as a basis for discussions amongst conference participants about possible ecohydrological relationships. The mires that were studied developed under a wide range of climatic conditions and included fens and bogs. The bogs typically developed from lakes or fens and most are now dominated by Sphagnum magellanicum. This species forms large hummocks, and can invade weakly-buffered fens. Most of the mires were well preserved, but effects of human impact - such as road building and peat extraction - were also noticeable.

  1. Phylogeography of the Patagonian otter Lontra provocax: adaptive divergence to marine habitat or signature of southern glacial refugia?

    Directory of Open Access Journals (Sweden)

    Chehébar Claudio

    2011-02-01

    Full Text Available Abstract Background A number of studies have described the extension of ice cover in western Patagonia during the Last Glacial Maximum, providing evidence of a complete cover of terrestrial habitat from 41°S to 56°S and two main refugia, one in south-eastern Tierra del Fuego and the other north of the Chiloé Island. However, recent evidence of high genetic diversity in Patagonian river species suggests the existence of aquatic refugia in this region. Here, we further test this hypothesis based on phylogeographic inferences from a semi-aquatic species that is a top predator of river and marine fauna, the huillín or Southern river otter (Lontra provocax. Results We examined mtDNA sequences of the control region, ND5 and Cytochrome-b (2151 bp in total in 75 samples of L. provocax from 21 locations in river and marine habitats. Phylogenetic analysis illustrates two main divergent clades for L. provocax in continental freshwater habitat. A highly diverse clade was represented by haplotypes from the marine habitat of the Southern Fjords and Channels (SFC region (43°38' to 53°08'S, whereas only one of these haplotypes was paraphyletic and associated with northern river haplotypes. Conclusions Our data support the hypothesis of the persistence of L. provocax in western Patagonia, south of the ice sheet limit, during last glacial maximum (41°S latitude. This limit also corresponds to a strong environmental change, which might have spurred L. provocax differentiation between the two environments.

  2. Taenia saginata Goeze, 1872 (Platyhelminthes: Cestoda: Taeniidae en un indígena de Tierra del Fuego, Chile

    Directory of Open Access Journals (Sweden)

    Eduardo I. Faúndez

    2015-06-01

    Full Text Available Se entrega el primer registro del céstodo Taenia saginata en un indígena de Tierra del Fuego (Patagonia chilena, correspondiente al año 1902. Se discute la importancia del registro y se entregan ilustraciones del ejemplar.

  3. Modelo matemático para la descripción de la transferencia de calor para tierra vertida

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez-Domínguez

    2014-01-01

    Full Text Available La arquitectura de tierra implica procesos constructivos sustentables ya que utiliza materiales vernáculos duraderos cuyos residuos son de bajo impacto al ambiente. La tierra vertida es una técnica a partir de la cual pueden tenerse muros resistentes dentro de la edificación de viviendas pero cuyas propiedades han sido poco evaluadas y representadas a partir de modelos. La transferencia de calor es una de las características más importantes cuando se edifica en zonas calurosas pues implica ciertos niveles de confort para los usuarios. El presente trabajo propone un modelo para determinar la difusividad térmica de tierra vertida con uso potencial para otras determinaciones a diversas temperaturas, algunas implicaciones también son presentadas. Se encontró que el coeficiente de difusividad térmica de muestras de tierra vertida fue de   4.319  10 8 m 2 s 1 , mientras que su calor específico es de 1.1030 kJkg-1K 1 .

  4. Familia nuclear y jefatura del hogar: acceso a la mujer a la tierra en las reformas agrarias

    Directory of Open Access Journals (Sweden)

    Magdalena León

    1999-10-01

    Full Text Available En este texto se analizan las consecuencias que la neutralidad de género ha dejado para la política pública, en el caso específico de las reformas agrarias y acceso de la mujer a la tierra en América Latina.

  5. La tierra en armas de Dávalos-Serrano (o las armas del teatro

    Directory of Open Access Journals (Sweden)

    Marcela Beatriz Sosa

    2003-01-01

    Full Text Available La tierra en armas (1926 constituye un texto enigmático por diversas cuestiones, a pesar de su celebridad –es la obra teatral más famosa de la literatura salteña- y de su aparente transparencia al representar hechos históricos relativos a la gesta de Güemes. El primer enigma es el problema de la autoría, ya que La tierra en armas surge de la escritura en colaboración de Juan Carlos Dávalos y Ramón Serrano, pero en el momento de publicación del texto (1935 aparecerá en la portada sólo el nombre de Dávalos. El gesto editorial de borrar el nombre del segundo autor en esa primera publicación es decisivo para el futuro teatral de Serrano, quien desaparece posteriormente de la escena salteña. La segunda cuestión deriva de la categoría de teatro histórico a la cual pertenece La tierra en armas La ficcionalización de un personaje histórico implica plantear las complejas relaciones que se establecen entre discurso dramático y discurso histórico. Luego de trazar someramente la trayectoria épica de Güemes, se realiza una descripción de la acción dramática y de los fundamentales procedimientos discursivos, como el encadenamiento entre la intriga principal (histórica y la secundaria (sentimental, la mise en abyme de la leyenda de la flor del Ilolay y la visualización escénica del texto. La tercera cuestión incluye el contexto de producción, circulación y recepción del teatro de la época, así como el nivel ideológico, sin los cuales sería imposible postular una interpretación del texto de Dávalos y Serrano como estrategia individual y colectiva de afianzamiento de la identidad.

  6. Respuesta transitoria de las puestas a tierra en la protección contra rayos. Software GTIERRAS

    Directory of Open Access Journals (Sweden)

    Héctor David Gómez Montoya

    2006-01-01

    Full Text Available Se usa un programa computacional desarrollado en Matlab (GTIERRAS que implementa un modelo de base electromagnética, para determinar la impedancia de puesta a tierra de configuraciones arbitrarias y su comportamiento ante excitaciones tipo impulso. Impedancia, corrientes y voltajes, u otras variables eléctricas de sistemas de puesta a tierra se pueden presentar en el dominio de la frecuencia o del tiempo usando la transformada rápida de Fourier. La base general del modelo considerado se usa para valorar no sólo sobretensiones por descargas atmosféricas, sino también, otros transitorios típicos asociados con problemas de compatibilidad electromagnética. Los resultados muestran la influencia de algunas variables en la respuesta del sistema de puesta a tierra y revelan algunas diferencias que se deben tener en cuenta cuando se aplican criterios basados en el desempeño a baja frecuencia, para esfuerzos impulsivos de puestas a tierra. Adicionalmente, se presentan ejemplos de cálculo y comparaciones con resultados de otros autores para ilustrar algunos comportamientos que de ninguna manera son evidentes. Se investiga además, el efecto de la geometría de los electrodos y la resistividad del suelo, así como del frente de onda y el número de puntos de inyección. También se presentan resultados de tensiones de contacto y de paso, así como, el estudio de un sistema de protección contra rayos como ampliación de las aplicaciones del modelo. Finalmente, se derivan algunas conclusiones útiles para el diseño de sistemas de puesta a tierra.

  7. RIESGOS CLIMÁTICOS EN LAS TIERRAS VALENCIANAS. INCIDENCIA EN LA ACTIVIDAD AGRARIA

    Directory of Open Access Journals (Sweden)

    Jorge Olcina Cantos

    1995-01-01

    Full Text Available La actividad agraria es el sector económico que, con mayor frecuencia, sufre los efectos de episodios atmosféricos excepcionales que ocasionan graves pérdi- das de cosecha y daños en campos de cultivo e infraestructura agraria (caminos, redes de riego. El campo valenciano no es ajeno a estos eventos, por lo demás condignos a sus condiciones climáticas (lluvias torrenciales, heladas, tormentas de granizo, temporales de viento y sequías, que precisan estudio de causas, consecuencias económicas y localización territorial de sectores de riesgo, para la posterior propuesta de medidas de actuación. La relación de prácticas de defensa puestas en práctica en tierras valencianas ante estos sucesos atmosféri- cos completa el presente estudio.

  8. El regreso de los judíos hispanos a Tierra Santa

    Directory of Open Access Journals (Sweden)

    Enrique Cantera Montenegro

    2004-01-01

    Full Text Available Tras un breve análisis acerca del lugar que la ciudad de Jerusalén y la Tierra Prometida ocupan en el judaismo y en la conciencia colectiva del pueblo judío, y del papel que la Ciudad Santa desempeña como meta de los peregrinos judíos, se estudian los movimientos de migración de los judíos hispanos hacia Palestina, a lo largo de la Edad Media y hasta el siglo XVII.After a brief analysis about the importance of Jerusalem and the Promised Land in the Judaism and in the collective consciousness of the Jewish people, and the role played by the Holy City as a destination for the Jewish pilgrims, the migration movements of the Spanish Jewish to Palestine are studied, along the Middle Ages, until the 17th century.

  9. Substations grounding systems design; Diseno de sistemas de conexion a tierra en subestaciones

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Sanchez, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The grounding systems have been the object of a great number of analytical and experimental studies in the past 15 years, that have given rise to research reports on the several aspects involved in this technique. In this work are briefly reviewed various aspects that is necessary to take into account for its design, analysis and put in operation. [Espanol] Los sistemas de conexion a tierra han sido objeto de gran cantidad de estudios analiticos y experimentales en los pasados quince anos, que han dado origen a informes de investigacion sobre los diversos aspectos que involucra esta tecnica. En este trabajo se revisan brevemente diversos aspectos que es necesario considerar para su diseno, analisis y puesta en operacion.

  10. Soil-water retention curve and beginning of monitoring in Tierra Blanca Joven (TBJ)

    International Nuclear Information System (INIS)

    Chavez, Jose; Lopez, Reynaldo; Kopecky, Lubomir; Landaverde, Jose

    2013-01-01

    The areas covered by the volcanic tephras Tierra Blanca Joven (TBJ) in El Salvador, was suffered mass movements, liquefaction and erosion during the rainy season or when major earthquakes occur, causing important environmental, social and economic losses. A pressure plate, centrifuge and filter paper were used to build a Soil-Water Retention Curve, obtain the characterization of these unsaturated soil, suction values of the fall unit of TBJ. The use of this curve into finite elements software can help to acquire shear strength and permeability properties. The filter paper showed to be a practical method but close to saturation the pressure plate is needed.Scatter results were observed with the centrifuge. The Quickdraw tensiometre (suction) and TMS3 (soil moisture content) are being used in field test to proposed a field methodology for an early warning system for the slopes, that could help in urban planning and risk assessment. (author)

  11. Soil-water retention curve and beginning of monitoring in Tierra Blanca Joven (TBJ)

    International Nuclear Information System (INIS)

    Chavez, Jose A.; Lopez, Reynaldo; Kopecky, Lubomir; Landaverde, Jose

    2013-01-01

    The areas covered by the Tierra Blanca Joven volcanic tephra (TBJ) have suffered hillside movements, liquefaction and erosion causing important environmental, social and economic losses during the rainy season or when earthquakes occur in El Salvador. Suction values of a TBJ drop unit were obtained with the pressure cooker, centrifuge and filter paper to construct the Soil-Water Retention Curve to initiate the characterization of these partially saturated soils. The use of this curve in finite element programs has helped to know the shear stresses and permeability. The filter paper has proved to be a practical method but it is necessary to use the pressure cooker as it becomes saturated. Field tests with tensiometer (suction) and TMS3 (humidity) have been carried out to propose field methodology for an early warning system for hillsides, which can help urban planning and risk studies. (author)

  12. La tierra entre derecho y cultura indígena en Argentina

    Directory of Open Access Journals (Sweden)

    Marzia Rosti

    2009-12-01

    Full Text Available The paper considers the relationships between the indigenous peoples and the Argentinian State since the XIX century until 1994, when it was introduced in the Constitution the provision acknowledging to the indigenous peoples “la posesión y propiedad comunitarias de las tierras que tradicionalmente ocupan”, “la entrega de otras aptas y suficientes para el desarrollo humano” and granting them “la parcipación en la gestión referida a sus recursos naturales y a los demás intereses que los afecten” (art. 75, inc. 17. The paper describes then the issue concerning the claim for indigenous land – raised by the new constitutional provision – and focuses on some significant cases and the more recent jurisprudence on that issue.

  13. Atmospheric electric discharges and grounding systems; Descargas atmosfericas y sistemas de conexion a tierra

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, Elena [ed.] [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In this article the work made by the Institute of Investigaciones Electricas (IIE), in the area of atmospheric electric discharges and grounding connections at Comision Federal de Electricidad (CFE) is presented. The work consisted of the revision of the procedures for the design of transmission lines and substations of CFE from which high indexes of interruptions are reported, from this, a program was defined that allowed to improve the existing designs in CFE. [Spanish] En este articulo se presenta el trabajo realizado por el Instituto de Investigaciones Electricas (IIE), en el area de descargas atmosfericas y conexiones a tierra en Comision Federal de Electricidad (CFE). El trabajo consistio en la revision de los procedimientos de diseno de las areas de transmision y subestaciones de la CFE para los que se reportan altos indices de salidas, a partir de esto se definio un programa que permitio mejorar los disenos existentes en la CFE.

  14. Substations grounding systems design; Diseno de sistemas de conexion a tierra en subestaciones

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Sanchez, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The grounding systems have been the object of a great number of analytical and experimental studies in the past 15 years, that have given rise to research reports on the several aspects involved in this technique. In this work are briefly reviewed various aspects that is necessary to take into account for its design, analysis and put in operation. [Espanol] Los sistemas de conexion a tierra han sido objeto de gran cantidad de estudios analiticos y experimentales en los pasados quince anos, que han dado origen a informes de investigacion sobre los diversos aspectos que involucra esta tecnica. En este trabajo se revisan brevemente diversos aspectos que es necesario considerar para su diseno, analisis y puesta en operacion.

  15. Violence in Tierra Caliente: Inequality, Development and Education Rates in Drug War

    Directory of Open Access Journals (Sweden)

    Raúl Zepeda Gil

    2017-10-01

    Full Text Available The following article presents the effects of social and economic variables on the increment of violence in regional areas of Mexico, upon the intensification of drug prohibitions policies established by former President Felipe Calderon’s administration. This study involved using a data panel of homicides rates with firearms in 31 municipalities of the region of Tierra Caliente for the time period between 2006 to 2012. The results from the study help indicate that agroindustrial development, income inequality, and education rates have been effected in correlation with the increasing of homicidal rates. Also, based on the relevance of the inequality indicators of the study, it can be argued that there is a possible coincidence between the literature of civil wars and sociology of crime in that can be used to explain such cases of violence.

  16. Parábola existencial de la primera Residencia en la Tierra

    Directory of Open Access Journals (Sweden)

    Eduardo Gómez

    1979-12-01

    Full Text Available Como sucede con muchos artistas, es el amor el que hace de Neruda un gran poeta. Su iniciación en la literatura universal data, sin duda, de los "Veinte poemas de amor y una canción desesperada" pero es a partír de "Residencia en la tierra" que logra afianzarse, en profundidad, como uno de los grandes poetas de la lengua castellana y uno de los más extraordinarios líricos de la historia de la literatura. En "Veinte poemas... ", el amor lo hace compenetrarse, estremecido, con la Naturaleza, lo desnuda de convenciones y prejuicios, lo embriaga de gozos dolorosos y le descubre todo el vasto mundo popular del drama sentim ental, depurado y abierto a la profundidad cósmica.

  17. Significações da queda em Residencia en la tierra

    OpenAIRE

    Luigi Patruno

    2011-01-01

    En el presente trabajo, estudio las variantes que asume la imagen de la caída en Residencia en la tierra de Pablo Neruda. Por un lado, la caída se vincula con la decadencia y la muerte y es el movimiento que insiste en la condición frágil del sujeto; por el otro, es imagen de un hundimiento deseable en la memoria, tensión positiva hacia el conocimiento y descenso poético. En mi análisis, procedo hacia una revisión general de los discursos críticos sobre la caída en los poemas de Neruda, propo...

  18. Early migration and estuary stopover of introduced chinook salmon population in the Lapataia River Basin, southern Tierra del Fuego Island

    Science.gov (United States)

    Chalde, T.; Fernández, D. A.

    2017-12-01

    Established populations of chinook salmon (Oncorhynchus tshawytscha) have recently been reported in South America, at both Atlantic and Pacific basins. Several studies have evaluated different aspects of their life histories; however, little is known about the use of the estuaries by the juveniles of these populations. We examined spawning time, seaward migration timing, growth rate, scale patterns, diet, and geometric morphometric, contrasting the early life history during freshwater and estuary residence of a chinook population established in Lapataia Basin. Fall run spawning took place in March-April and the parr emerged in September. Two distinct seaward migration patterns were identified from sein net fishing records: one population segment migrating earlier to the estuary in October and a second group migrating later in February. The growth rate of fish captured at the estuary was significantly higher than the fish captured in freshwater. In addition, higher scale intercirculi distances were observed in estuary fish showing differences in growth rate. The feeding habitat in fish captured in both environments changed through time from bottom feeding to surface feeding and from significant diet overlap to no overlap. The morphology of the fish captured at the estuary was associated with the elongation of the caudal peduncle and a decrease in the condition factor index, both changes related to smolt transformation. The earlier migration and the higher growth rate of juveniles in the estuary together with fish of 1 + yo captured in this environment reveal that the estuary of Lapataia Basin is not only a stopover for the chinook salmon, but also a key habitat to reside and feed previous to the final seaward migration.

  19. Bryophyte-cyanobacteria associations during primary succession in recently Deglaciated areas of Tierra del Fuego (Chile).

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De Los Ríos, Asunción; Green, T G Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g-1 bryo. d-1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g-1 bryo. d-1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition.

  20. Guanaco’s diet and forage preferences in Nothofagus forest environments of Tierra del Fuego, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Quinteros, C.P.; Bava, J.; Gobbi, M.E.; Defossé, G.E.

    2017-11-01

    Aim of study: Guanaco (Lama guanicoe Müller), is a South American native ungulate widely distributed in Patagonia, which in the island of Tierra del Fuego (TF), extends its habitat into Nothofagus spp. forests. Within these forests, guanacos consume lenga (Nothofagus pumilio) leaves and twigs, and other understory species. The aim of this work was to determine: 1) the spring and summer diet of free ranging guanacos, and 2) which plants, grown in the forest understory, guanacos do prefer, or avoid, in these seasons of great forage abundance. Area of study: Tierra del Fuego (Argentina), on three representative areas which combined Nothofagus forests and adjacent meadows (vegas). Material and Methods: uanacos’ diet was determined by comparing epidermal and non-epidermal plant fragments with micro-histological analyses of feces. The analysis was made from composite samples of fresh feces, collected at the seasons of maximum forage productivity (spring and summer). Main results: During spring, 48% of guanacos’ diet was composed of lenga leaves, 30% of grass-like species, 15% of grasses, and less than 7% of herbs, shrubs, and lichens. In summer, 40% of the diet was composed of grasses, 30% of lenga leaves, 25% of grass-like species and the rest corresponded to herbs, shrubs, and lichens. Within the forest understory, guanaco selected lenga leaves and twigs, grass species were consumed according to their availability (or sometimes rejected), while other herbs were not consumed at all. Research highlights: Guanacos’ consumption preference for lenga, even considering the high availability of other forages, could adversely affect forest regeneration.

  1. Bryophyte-Cyanobacteria Associations during Primary Succession in Recently Deglaciated Areas of Tierra del Fuego (Chile)

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De los Ríos, Asunción; Green, T. G. Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G.

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g−1 bryo. d−1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g−1 bryo. d−1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition. PMID:24819926

  2. Guanaco’s diet and forage preferences in Nothofagus forest environments of Tierra del Fuego, Argentina

    International Nuclear Information System (INIS)

    Quinteros, C.P.; Bava, J.; Gobbi, M.E.; Defossé, G.E.

    2017-01-01

    Aim of study: Guanaco (Lama guanicoe Müller), is a South American native ungulate widely distributed in Patagonia, which in the island of Tierra del Fuego (TF), extends its habitat into Nothofagus spp. forests. Within these forests, guanacos consume lenga (Nothofagus pumilio) leaves and twigs, and other understory species. The aim of this work was to determine: 1) the spring and summer diet of free ranging guanacos, and 2) which plants, grown in the forest understory, guanacos do prefer, or avoid, in these seasons of great forage abundance. Area of study: Tierra del Fuego (Argentina), on three representative areas which combined Nothofagus forests and adjacent meadows (vegas). Material and Methods: uanacos’ diet was determined by comparing epidermal and non-epidermal plant fragments with micro-histological analyses of feces. The analysis was made from composite samples of fresh feces, collected at the seasons of maximum forage productivity (spring and summer). Main results: During spring, 48% of guanacos’ diet was composed of lenga leaves, 30% of grass-like species, 15% of grasses, and less than 7% of herbs, shrubs, and lichens. In summer, 40% of the diet was composed of grasses, 30% of lenga leaves, 25% of grass-like species and the rest corresponded to herbs, shrubs, and lichens. Within the forest understory, guanaco selected lenga leaves and twigs, grass species were consumed according to their availability (or sometimes rejected), while other herbs were not consumed at all. Research highlights: Guanacos’ consumption preference for lenga, even considering the high availability of other forages, could adversely affect forest regeneration.

  3. Knowing for controlling: ecological effects of invasive vertebrates in Tierra del Fuego Conocer para controlar: efectos ecológicos de vertebrados invasores en Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    CLAUDIA A SILVA

    2008-03-01

    Full Text Available The Tierra del Fuego (TDF archipelago is recognized as part o the last places on Earth that may still be considered wild. However, this condition may be threatened by the large number of invasive species present on the archipelago. These species can have significant effects on the ecology of the invaded ecosystems, at the genetic as well as at population, community and ecosystem levels. The aim of this study is to, by a bibliographic review, systematize existing information on the ecological impacts these species would be having on the TDF archipelago and detect information gaps in order to orient future research and effective management programs on these species. We restricted our review to vertebrate, non-marine invaders. We determined which species have invaded TDF, described their impacts on the archipelago and evaluated their potential impacts; this last issue was determined by reviewing some of the impacts these species have had in other geographic areas. Our findings indicate that at least nine vertebrate species (Salmo trutta, Salvelinus fontinalis, Oncorhynchus mykiss, Castor canadensis, Ondatra zibethicus, Oryctolagus cuniculus, Pseudalopex griseus, Mustela vison and Sus seroja have wild populations established away from human settlements in TDF. There is some scientific evidence on ecological impacts on the area for only five of these invaders, with the American beaver (Castor canadensis being the species monopolizing the greatest number of studies. These results contrast with the recognition, both in TDF and worldwide, of the potential of most of these species to cause significant ecological impacts, which makes it unlikely that the lack of verified impacts on TDF reflects an absence of significant effects of these invaders on the archipelago. We suggest that future research should focus on determining population density and distribution of these and other (i.e., feral species invasive vertebrates, as well as their impacts mainly on

  4. Centro de Control de Tierra para Colaboración de Vehículos Autónomos Marinos

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    J.A. Bonache Seco

    2017-12-01

    donde la incorporación del operador en la supervisión y control de las maniobras de los vehículos es un requisito imprescindible para dar seguridad y confianza a la operación realizada. Finalmente, se presenta un caso de uso del Centro de Control de Tierra donde se realiza una maniobra de seguimiento entre dos vehículos autónomos de superficie.

  5. Fate of a broad spectrum of perfluorinated compounds in soils and biota from Tierra del Fuego and Antarctica

    International Nuclear Information System (INIS)

    Llorca, Marta; Farré, Marinella; Tavano, Máximo Sebastián; Alonso, Bruno; Koremblit, Gabriel; Barceló, Damià

    2012-01-01

    In this study, the presence of 18 perfluorinated compounds was investigated in biota and environmental samples from the Antarctica and Tierra de Fuego, which were collected during a sampling campaign carried out along February and March 2010. 61 samples were analysed including fish, superficial soils, guano, algae, dung and tissues of Papua penguin by liquid chromatography coupled to tandem mass spectrometry. The concentrations of PFCs were ranging from 0.10 to 240 ng/g for most of the samples except for penguin dung, which presented levels between 95 and 603 ng/g for perfluorooctane sulfonate, and guano samples from Ushuaia, with concentration levels of 1190–2480 ng/g of perfluorohexanoic acid. PFCs acids presented, in general, the highest levels of concentration and perfluorooctanesulfonate was the most frequently found compound. The present study provides a significant amount of results, which globally supports the previous studies, related to the transport, deposition, biodegradation and bioaccumulation patterns of PFCs. - Highlights: ► 61 samples from the Antarctica and Tierra de Fuego analysed for the presence of 18 perfluorinated compounds. ► Acid compounds presented the highest levels of concentration and perfluorooctane sulfonate was the most frequently found. ► Concentrations in algae much higher than those in soils. ► Data supporting existing models for the transport, deposition, biodegradation and bioaccumulation patterns are presented. - 18 perfluorinated compounds assessed in biota and environmental samples from Tierra del Fuego and the Antarctica. Concentrations related to Compounds properties.

  6. Género y arrebato de tierras: el caso del nuevo aeropuerto internacional de Ciudad de México

    Directory of Open Access Journals (Sweden)

    Verónica Vázquez García

    2018-09-01

    Full Text Available En este artículo se explora la dinámica de género del arrebato de tierras en el municipio de Atenco, Estado de México, para la construcción del nuevo aeropuerto internacional de la Ciudad de México. A partir de datos obtenidos mediante la sistematización de expedientes ejidales, la observación participante y las entrevistas a profundidad, se analiza la discriminación de género en la venta de tierras y las estrategias de las mujeres para enfrentarla. El artículo contribuye a estudiar la infraestructura de comunicaciones, un sector poco teorizado; a utilizar información documental, principalmente testimonial, y a visibilizar los efectos de género y el papel de las mujeres en la resistencia. Se muestra que los agentes del arrebato de tierras son el Estado, el capital y las estructuras comunitarias que reproducen la inequidad de género, para concentrar la riqueza y los privilegios políticos en manos predominantemente masculinas.

  7. Seguimiento al comportamiento del mercado de tierras rurales a través de un GIS, Santander Colombia

    Directory of Open Access Journals (Sweden)

    Ricardo Lozano-Botache

    2016-01-01

    Full Text Available A pesar de los marcos legales y políticas públicas, en algunos países, los derechos de propiedad sobre la tierra siguen siendo usurpados o impedidos con métodos violentos. Este trabajo de investigación, desde el marco de referencia de la Administración de Tierras, el Neoinstitucionalismo y las herramientas computacionales –conocidas genéricamente como Sistemas de Información Geográfica (GIS, por sus siglas en inglés– presenta un modelo de observación regional de precios que, por la secuencia de datos y su proceso informático, puede mantenerse a través del tiempo como referente en procesos agrarios de restitución de tierras a víctimas del despojo, así como en la ejecución de proyectos de desarrollo social o económico.

  8. Negociando la tierra: empresas extranjeras, minería a gran escala y derechos humanos en Colombia

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    Juan David Velasco

    2014-01-01

    Full Text Available La adquisición masiva de tierras por parte de empresas extranjeras en países africanos, asiáticos y latinoamericanos refleja una nueva fase del capitalismo global (Sassen, 2013. Colombia no ha escapado a esta lógica mundial del capitalismo, pues en la última década la influencia de las empresas extranjeras en el mercado de tierras ha sido notoria. En esa lógica, este artículo compara, desde un enfoque de Derechos Humanos, las prácticas de adquisición de tierras de tres compañías extranjeras que han explotado carbón a cielo abierto en La Guajira y Cesar. Los resultados indican que la formalidad de la propiedad agraria y las restricciones institucionales de las empresas —asociadas al gobierno corporativo, la participación en bolsa de valores y el veto de compradores internacionales—influyen significativamente en el respeto a los derechos humanos.

  9. PERSPECTIVAS DEL PROCESO DE TITULACIÓN DE TIERRAS EN LA COMUNIDAD CAMPESINA SAN JUAN DE MIRAFLORES, 2011

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    Roger Ricardo Ríos Ramirez

    2014-12-01

    Full Text Available El objetivo del trabajo fue evaluar las perspectivas hacia la titulación de tierras en la Comunidad Campesina San Juan de Miraflores (CCSJM.El estudio fue de tipo descriptivo, con un diseño no experimental transversal. Se aplicó un cuestionario estructurado para evaluar perspectivas a una muestra de 353 comuneros seleccionados de manera aleatoria, estratificada y proporcional, previa validación de expertos y con una confiabilidad alfa de Cronbach α =  0.944.En la CCSJM, las parcelas no tienen las características necesarias para que la agricultura o ganadería se desarrollen, asimismo la actividad campesina no es la principal actividad económica. Asimismo, los comuneros de la CCSJM muestran una perspectiva favorable hacia la titulación de tierras.Por lo tanto, consideramos imperante el proceso de titulación de tierras y la promoción de opciones laborales distintas a las que usualmente realiza un campesino.

  10. ANÁLISIS PRELIMINAR DEL TRATAMIENTO FISICOQUÍMICO Y BIOLÓGICO DEL ACEITE DIELÉCTRICO PRESENTE EN TIERRA FULLER

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    EDISON ALEXANDER AGUDELO

    2011-01-01

    Full Text Available Este estudio evalúa dos tecnologías: una físico-química y otra biológica, que buscan eliminar la contaminación por el aceite dieléctrico presente en la tierra Fuller, Buscando con ello gestionar de forma ambientalmente adecuada este residuo peligroso. Para la Tecnología físico-química, se usó hexano como solvente y se alcanzó de manera preliminar remociones del aceite dieléctrico del orden del 87% en la tierra Fuller tratada, con una relación tierra Fuller: solvente de 1:8 p/v, una velocidad de agitación de 100 rpm y un tiempo de contacto de 30 minutos. La calidad del aceite dieléctrico recuperado no es apta para su uso en equipos eléctricos, por su baja rigidez dieléctrica, baja densidad y color desfavorable. La tierra Fuller recuperada alcanzó una densidad aparente de 0.623 gr/ml, una densidad real de 2.231 gr/ml y una porosidad de 72.075 %, lo que indica al menos preliminarmente que dicha tierra está muycercana en sus características físicas a la tierra fuller limpia. Para la tecnología biológica se trató la tierra contaminada en un reactor biológico de tierra activada, evaluando la velocidad de agitación y el tiempo de degradación necesario para alcanzar niveles de contaminación adecuados que permitan disponer el residuo en un relleno sanitario convencional sin riesgo para la salud de los ecosistemas y el ser humano, esta fase aún se encuentra en experimentación y los resultados dependen del análisis cromatográfi co del aceite dieléctrico que permanece en la tierra Fuller tratada, en el cual se hará el seguimiento de 10 especies que son clave dentro de este producto, debido a su cantidad y/o toxicidad , falta comprobar la calidad química de la tierra fuller y del aceite dieléctrico recuperados en el tratamiento físico-químico, y validar el proceso biológico para degradar el aceite dieléctrico.

  11. Tierras estatales y desigualdad de género en Uruguay=State lands and gender inequality in Uruguay

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    Paula Florit O`Neill

    2017-06-01

    Full Text Available Resumen En Uruguay, el Instituto Nacional de Colonización (INC es la institución encargada de la adjudicación de tierra por parte del Estado, orientado a la distribución racional de la tierra y su acceso por parte de la población rural más vulnerable. A partir del año 2005, atravesó una reforma que jerarquizó su rol en las políticas de Estado y gestó un nuevo modelo de adjudicación de tierras: las experiencias asociativas. Ese mismo año, el nuevo gobierno impulsó la transversalización de género en el Estado, impulso que anclara en el INC a partir del 2013. Este artículo analiza desde una perspectiva de género la reforma refundacional y la nueva política de tierras, develando la ceguera de género de la reforma y evidenciando desafíos pendientes para la transversalización de género en el diseño de la principal modalidad de adjudicación de tierras públicas.      Abstract In Uruguay, the National Institute of Colonization is the institution resposible for the adjudication of land by the State, aimed at the rational distribution of land and its access by the most vulnerable rural population. Since 2005, the INC went through a reform that prioritized its role in the policies of the State and created a new model of land adjudication: associative experiences of colonization. In that same year, the new government promoted gender mainstreaming in the State, impulse that took roots in the INC from 2013 onwards. This article analyzes from a gender perspective the refounding reform and the new land policy, unveiling the gender blindness of the reform and highlighting pending challenges for gender mainstreaming in the design of the main public land adjudication modality.

  12. Health at the Extremes. Epidemiological and Sanitary Scene in Tierra del Fuego, 1890-1930

    Directory of Open Access Journals (Sweden)

    Romina Casali

    2014-05-01

    Full Text Available Objective: To characterize the epidemiological and sanitary conditions of the city of Ushuaia (National Territory of Tierra del Fuego at a key time in its history- a time in which interethnic contact and the consolidation of the Argentine nation-state were intensified as two parallel and related processes. Materials and methods: All death certificates available for the period 1890-1930 were analyzed, as well as relevant government documents and secondary sources in order to ob¬tain the health profile of the city and its relationship with the country in the following aspects: type of epidemiological phase, mortality rates, population structure, and the structure in health¬care. Conclusions: There was a great relevance of infectious diseases, and specially tuberculosis, among the population of the city in general, and among the indigenous and criminal population in particular. This epidemiological profile showed the shortcomings of a national health system that was trying to establish at the time, especially in a region difficult to reach.

  13. Arriendo y desigualdad en las tierras altas de Jujuy (Argentina a fines del siglo XIX

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    Cecilia A. Fandos

    2016-01-01

    Full Text Available Las estructuras agrarias originadas en los procesos más generales de desarrollo capitalista y de redefinición de los derechos de propiedad del siglo XIX en la provincia argentina de Jujuy, resultaron favorables a la formación de importantes latifundios. La contracara de esa fuerte concentración de tierras fue la existencia de un amplio sector de la sociedad que compartía la condición de arrendatarios. De ahí que en este artículo nos proponemos estudiar a los arrendatarios como productores –la riqueza y los ingresos brutos procedentes de la explotación rural que tenían a su cargo– a fin de indagar su capacidad de remuneración, contrastándolos entre sí y con otras situaciones sociales. Para ello, analizamos dos casos que tratan el asunto de sus relaciones de producción en el arriendo. A partir de fuentes fiscales y censales de la década de 1890 que contienen datos de la actividad agropecuaria y de informes sobre la rentabilidad de los distintos productos de origen agrícola o ganaderos de la misma época, reconstruimos el ingreso bruto de esas unidades para cada uno de los actores involucrados en ellas y analizamos los niveles de desigualdad para ese conjunto social.

  14. Functional ecology of soil microbial communities along a glacier forefield in Tierra del Fuego (Chile).

    Science.gov (United States)

    Fernández-Martínez, Miguel A; Pointing, Stephen B; Pérez-Ortega, Sergio; Arróniz-Crespo, María; Green, T G Allan; Rozzi, Ricardo; Sancho, Leopoldo G; de Los Ríos, Asunción

    2016-09-01

    A previously established chronosequence from Pia Glacier forefield in Tierra del Fuego (Chile) containing soils of different ages (from bare soils to forest ones) is analyzed. We used this chronosequence as framework to postulate that microbial successional development would be accompanied by changes in functionality. To test this, the GeoChip functional microarray was used to identify diversity of genes involved in microbial carbon and nitrogen metabolism, as well as other genes related to microbial stress response and biotic interactions. Changes in putative functionality generally reflected succession-related taxonomic composition of soil microbiota. Major shifts in carbon fixation and catabolism were observed, as well as major changes in nitrogen metabolism. At initial microbial dominated succession stages, microorganisms could be mainly involved in pathways that help to increase nutrient availability, while more complex microbial transformations such as denitrification and methanogenesis, and later degradation of complex organic substrates, could be more prevalent at vegetated successional states. Shifts in virus populations broadly reflected changes in microbial diversity. Conversely, stress response pathways appeared relatively well conserved for communities along the entire chronosequence. We conclude that nutrient utilization is likely the major driver of microbial succession in these soils. [Int Microbiol 19(3):161-173 (2016)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  15. EVALUATION OF INSECTICIDES FOR PEST CONTROL IN MANGO (Mangifera indica L. IN TIERRA CALIENTE, GUERRERO, MEXICO

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    Yuridia Duran

    2017-12-01

    Full Text Available The mango crop is attacked by various pests, in Arcelia, Tierra Caliente, Guerrero, Mexico. Scale insects (Hemiptera and thrips (Thysanoptera were identified, the pesticides imidacloprid, spinosad, sulfur and mineral oil were tested against them, as well as their effect on fruit quality, using pest action thresholds. The thrips Frankliniella invasor appeared in the highest populations, but F. difficilis, F. occidentalis, F. fortissima, F. cephalica, Leptothrips macconnelli, L. bifurcatus and L. theobromae were also found. It was observed that mineral oil maintained the lowest populations and least damage in fruit; thrips species did not cause significant damage because they were seasonal pests that only occur when soft tissue is available in plants and once this tissue becomes unavailable populations diminish without the need of insecticides.  The mite Cisaberoptus kenyae was identified, which in high populations can cause crop damage; for its control sulfur yielded better results. The scale Milviscutulus mangiferae was present in very low populations. Treatment with mineral oil resulted in the highest quality fruits.

  16. MICROFUNGAL COMPOSITION IN AN ASTELIA-DONATIA CUSHION PEATLAND IN TIERRA DEL FUEGO, ARGENTINA

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    Noelia I. Paredes

    2014-01-01

    Full Text Available En el Hemisferio Sur las turberas almacenan grandes cantidades de carbono en el suelo. A pesar de su importancia en el ciclo global del carbono, se sabe poco acerca de los procesos de descomposición y su diversidad fúngica. El presente estudio se realizó para describir la composición de hongos filamen - tosos en dos profundidades de una turbera compacta donde las especies vegetales predominantes son Astelia (Asteliaceae y Donatia (Donatiaceae en Moat, Tierra del Fuego, Argentina. De 48 muestras procesadas, se obtuvieron 338 aislamientos. Mediante el uso de diferentes metodologías de cultivo, a través de observación microscópica y por métodos moleculares identificamos 38 especies fúngicas y 18 géneros de Ascomycetes y Zygomycetes. Los aislamientos de Ascomycetes fueron los más abundantes, con dominancia de Penicillium y Trichoderma . Se describe la composición fúngica y se comparó la diversidad y equitatividad de las especies a dos profundidades de muestreo. No se encontraron diferencias significativas entre la composición de especies, la diversidad y equitatividad. La turbera estudiada es un ecosistema que presenta alta diversidad de especies fúngicas filamentosas, algunas de ellas descritas en otras turberas en todo el mundo.

  17. Tierras de la microcuenca potrerillo (Cauca, Colombia: Clasificación local en relación con propiedades edáficas.

    Directory of Open Access Journals (Sweden)

    Cerón Rengifo Carmen Patricia

    2003-12-01

    Full Text Available Este estudio se realizó con el objetivo de relacionar la clasificación local de tierras con propiedades físicas, químicas y biológicas del suelo. Se hicieron entrevistas a 36 agricultores de la microcuenca, Potrerillo, Cauca, Colombia, para considerar criterios culturales de clasificación local; se tomaron muestras de suelo en 8 tierras, de 0 a 5 y 0 a 20 cm, con 5 repeticiones. Se determinó color, textura, N y P disponible, C total, fracción liviana de materia orgánica (LL, PH, Ca, K, Mg y Al. Los datos se trabajaron estadísticamente a partir de análisis de varianza, prueba Duncan y análisis de clasificación de datos. La información sugiere que los agricultores diferencias las tierras a partir de la ubicación, características físicas del suelo y de categorías culturales llamadas tierra buena, mala, brava y cansada. Las tierras consideradas buenas se relacionan con colores pardos oscuros, contenidos más altos de N, C y fracción LL, mayor densidad de miriápodos en tierras con vegetación arbórea y mayor biomasa de lombrices en barbecho de la parte baja de la colina. Entre las tierras de menor calidad, disminuye N, C fracción LL y Al y aumenta el pH; en aquellas que no son utilizadas son frecuentes los colores amarillos o rojos, decrecen los valores de N, C, LL, Ph y se incrementa el Al.

  18. On the presence of upper paleocene rocks in the foreland succession at Cabo Nariz, Tierra del Fuego, Chile: Geology and new palynological and U-Pb data

    International Nuclear Information System (INIS)

    Sanchez, Alejandro; Pavlishina, Polina; Godoy, Estanislao; Herve, Francisco; Fanning, C.Mark

    2010-01-01

    On the west coast of Tierra del Fuego, south of Cabo Nariz, in Chile, Upper Cretaceous to Paleocene sedimentary successions of the Magallanes foreland basin crop out. The presence of dinoflagellate cysts, as well as radiometric U-Pb SHPJMP dating of detrital zircons, indicate that this succession ranges from the Campanian to Thanetian (Late Paleocene) in age. The base of the exposed sedimentary succession comprises siltstones of external platform facies (Cerro Cuchilla Formation), which are thrust over the Cabo Nariz Beds. The latter fonnation is divided into two members: a lower siltstone-dominated turbidite facies member and an upper member of sandstone-dominated turbidites, with sandstone and conglomerate channel facies. The presence of dinocysts in the Cerro Cuchilla Formation suggests a late Campanian to early Danian age. The fossil content in the Cabo Nariz Beds indicate a Selandian (Middle Paleocene) depositional age in accordance with the detrital zircon ages which provide a maximum possible Campanian age (76.5±0.7 Ma), and very close to the Thanetian (Late Paleocene) (57.6±1 Ma) depositional ages for the lower and upper member, respectively. The sedimentary succession of Cabo Nariz Beds, is interpreted as a north-northwest prograding submarine fan of middle to Late Paleocene age. It is considered to represent the deposition of detritus derived from an uplifting orogen located to the south. The detrital zircon age spectra suggest that there was a period of low intensity of magmatic activity in the source area around the K-T boundary

  19. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  20. El escritor, las sombras y la Patria: En esta dulce tierra de Andrés Rivera The writer, the shadows and the homeland in Andrés Rivera's "La dulce tierra"

    Directory of Open Access Journals (Sweden)

    Carmen Perilli

    2007-12-01

    Full Text Available La novela En esta dulce tierra arma un simulacro histórico que se desintegra en una narración de finales múltiples. Parodia su nombre "en esta dulce tierra" ya que el circunstancial anuncia sucesos terribles que hacen estallar el adjetivo. Remite a la literatura decimonónica, en especial a los romances fundacionales como Amalia de José Mármol. La nación se imagina como espacio cerrado, clausurado por el despotismo en el asilo, la morgue, la cárcel, el sótano. Los protagonistas se mueven ilusoriamente de Sur a Norte. Si Sarmiento invoca la sombra de Facundo, Rivera evoca en Cufré otras propias sombras, dobles en tiempos y lugares otros. La narración de la historia argentina es la narración de una derrota, la de la civilización. La imagen histórica es disfórica: el mundo está enfermo, ebrio de sangre y violencia. Facundo es la sombra de la barbarie, cifra de la naturaleza americana, producto de los llanos riojanos. Cufré es la sombra de una clase "culta" que dibuja en su trayectoria una figura paradojal. Las dos son víctimas de una tierra concebida como naturaleza bárbara en un caso y de una tierra construida como patria siniestra en el otro. El Poder actúa como una segunda naturaleza que, en esta tierra, tiene el sabor de la muerte.The novel En esta dulce tierra sets up a historical pretense that disintegrates into several endings. The title is an irony, since terrible events take place in this "sweet land." It refers to the literature of the XIX century, especially to the founding romances such as that of José Mármol's Amalia. The nation is envisioned as a closed space relegated by despotism to the asylum, the morgue, the jail, the basement. The characters live an illusion moving from north to south. If Sarmiento invokes the shadow of Facundo, Rivera evokes some of his own shadows in Cufré, doubles in different times and spaces. The narration of the Argentine history is a story of defeat: civilizarion's. The historical

  1. Channel box

    International Nuclear Information System (INIS)

    Tanabe, Akira.

    1993-01-01

    In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)

  2. La ganadería lanar en Madrid y su tierra durante la Edad Media

    Directory of Open Access Journals (Sweden)

    Tomás Puñal Fernández

    1998-01-01

    Full Text Available El estudio de la ganadería en general y ovina en particular ofrece un campo muy generoso de investigación porque permite conocer muchas de las estructuras socioeconómicas regionales y locales de un país o territorio. En el caso de Madrid dicho estudio es importante por cuanto en el conjunto de las labores agropecuarias del concejo, las ganaderas fueron las que mejor marcaron su desarrollo económico. La tierra madrileña es tierra de ganado, sobre todo lanar, y ello fue el punto de referencia de diversas actividades económicas que iban desde el abastecimiento de carne para la alimentación hasta la obtención de materia prima, lana y pieles, para las industrias textil y del cuero. Para tener una visión más amplia e interdisciplinar el presente estudio se ha hecho desde una doble perspectiva económica y social. Desde la ganadería estante y local a la trashumante, con especial mención a la Mesta y toda su problemática, así como los aspectos cuantitativos derivados del número de ovejas y el tamaño y tipo de los rebaños y sus aspectos fiscales concomitantes. En relación a ello toda la infraestructura de pastos y cañadas. Los aspectos sociales se refieren a los propietarios de ovejas como una oligarquía rural de labradores enriquecidos, así como a los trabajadores del ganado, es decir los pastores, sus contratos, salarios y condiciones de vida. En conjunto el panorama que se ofrece es muy significativo y permite acercarnos un poco más a la realidad socioeconómica del Madrid medieval.The study of the livestock in general and sheep in particular, offers a huge field to research as it allows to know many of the local and regional socioeconomíc structures of a city or country. In the case of Madrid, that study is important because the sheep livestock is, among the rest of the agricultural activities, the main one for its contribution to the economic development. Madrid is a livestock área, mainly for sheep, as the point of

  3. Mires and mire types of Peninsula Mitre, Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    A. Grootjans

    2014-01-01

    Full Text Available In 2007, a field visit by members of the International Mire Conservation Group (IMCG to the Atlantic coast of Peninsula Mitre (the easternmost part of Isla Grande de Tierra del Fuego, Argentina gathered information on mire diversity in this remote wild area with largely pristine mires. Our expedition showed that Peninsula Mitre hosts a wide variety of habitats across two exciting ecological gradients: (i a regional west–east gradient from Sphagnum magellanicum dominated mires in the west to Astelia pumila dominated mires in the east; and (ii a gradient from extremely acid to extremely carbonate rich mire types induced by local bedrock. The large variety of hydromorphological mire types comprises raised bogs, blanket bogs, sloping fens, string fens, flat fens and calcareous spring fens. In the Atlantic coastal area, the abundance of Sphagnum magellanicum in the ombrogenic systems decreases conspicuously from west to east with the species being almost absent in the east. However, the fossil record shows thick layers of Sphagnum peat close beneath mire surfaces everywhere, indicating that substantial hydrological and ecological changes have taken place in the recent past. We observed large scale erosion in the mires along the Atlantic coast. Locally, well-developed fen systems are present, including calcareous spring fens with active travertine (tufa deposition. The regional vegetation can be regarded as a parallel to that of boreal oceanic regions in the northern hemisphere. The mires and peatlands of the peninsula are of global significance. They are impressive, peculiar, extensive and largely pristine mires in a globally very rare climatic and biogeographical context embedded in a landscape with significant natural dynamics. The damaging impact of free-roaming cattle on the mires and upland vegetation is, however, conspicuous and needs urgent attention. Peninsula Mitre deserves the highest possible protection, e.g. as a provincial protected

  4. Geoprocesamiento aplicado al analisis del uso de la tierra en el municipio de San Pedro de Ycuamandyyú , Paraguay

    Directory of Open Access Journals (Sweden)

    Oscar Agustín Figueredo Torres

    2002-01-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  5. Geoprocesamiento aplicado al analisis del uso de la tierra en el municipio de San Pedro de Ycuamandyyú, Paraguay.

    Directory of Open Access Journals (Sweden)

    Oscar Agustín Torres Figueredo

    2010-08-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  6. GEOPROCESAMIENTO APLICADO AL ANALISIS DEL USO DE LA TIERRA EN EL MUNICIPIO DE SAN PEDRO DE YCUAMANDYYÚ, PARAGUAY

    Directory of Open Access Journals (Sweden)

    Oscar Agustín Torres Figueredo

    2002-10-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  7. Surface channeling

    International Nuclear Information System (INIS)

    Sizmann, R.; Varelas, C.

    1976-01-01

    There is experimental evidence that swift light ions incident at small angles towards single crystalline surfaces can lose an appreciable fraction of their kinetic energy during reflection. It is shown that these projectiles penetrate into the bulk surface region of the crystal. They can travel as channeled particles along long paths through the solid (surface channeling). The angular distribution and the depth history of the re-emerged projectiles are investigated by computer simulations. A considerable fraction of the penetrating projectiles re-emerges from the crystal with constant transverse energy if the angle of incidence is smaller than the critical angle for axial channeling. Analytical formulae are derived based on a diffusion model for surface channeling. A comparison with experimental data exhibits the relevance of the analytical solutions. (Auth.)

  8. El acaparamiento de tierras como proceso dinámico. Las estrategias de los actores en contextos de estancamiento económico

    Directory of Open Access Journals (Sweden)

    Carla Gras

    2017-01-01

    Full Text Available Este artículo pretende contribuir a la comprensión de los procesos de acaparamiento de tierras. A partir de un análisis realizado en el norte de Córdoba (Argentina, se sugiere que dicho fenómeno: (a no es lineal, uniforme ni se incrementa de manera sostenida en el tiempo; y (b no se limita a la concentración de tierras sino que integra recursos estratégicos (financieros, tecnológicos, gerenciales que convergen en el objetivo más general de acaparamiento de capital. Analizamos una dinámica específica, la “ralentización” o disminución en la cantidad de tierra controlada por las empresas, bajo la hipótesis que ella no constituye necesariamente una retracción del acaparamiento.

  9. Modelos del planeta Tierra en escolares rurales de Chile / Planet Earth models about students in rural schools from Chile

    Directory of Open Access Journals (Sweden)

    Paula Alonqueo Boudon

    2015-12-01

    Full Text Available RESUMEN El presente estudio tuvo como objetivo identificar los modelos del planeta Tierra en escolares mapuches y no mapuches de procedencia rural. Los participantes fueron 40 escolares distribuidos en dos grupos de edad, quienes respondieron a una tarea cognitiva que indaga la representación de la forma del planeta Tierra. En base al grado de acuerdo con la representación científica, cada participante fue categorizado en uno de cuatro modelos del planeta Tierra. El modelo 4, concordante con el conocimiento científico, no fue observado, pues la mayoría de los participantes se concentra en el modelo 3 en el que coexisten conocimientos previos con algunos elementos científicos. En los niños no mapuches se aprecia que el modelo del planeta Tierra se ajusta a los significados científicos a medida que aumenta el conocimiento escolar. Por el contrario, en los niños mapuches no se observa esta tendencia. Se discute el papel de la cultura y la enseñanza en el aprendizaje del modelo científico del planeta. ABSTRACT The aim of this study was to identify planet Earth models in mapuches and non mapuches students of rural origin. The participants were 40 students divided into two age groups who responded to a cognitive task which explores the representation of the shape of the planet Earth. Based on the degree of agreement with the scientific representation, each participant was categorized into one of four models of planet Earth. Model 4, consistent with the scientific knowledge was not observed because the majority of the participants were concentrated in Model 3. In non mapuche children, it is observed that the model of the planet Earth is adjusted to the scientific meaning in accordance with the increase of school knowledge. On the other hand, this trend is not observed in mapuche children. The role of culture and teaching is discussed in the learning of planet scientific model.

  10. Género, propiedad y empoderamiento: tierra, Estado y mercado en América Latina [Reseña

    OpenAIRE

    García Núñez, Luis Fernando; León, Magdalena; Deere, Carmen Diana

    2001-01-01

    Es un texto de una gran importancia para el momento actual. Un documento que trabaja el problema de género desde otras perspectivas. Integra el conflicto alrededor de las fronteras de lo social, lo político, lo cultural y lo económico. "Desde nuestra investigación inicial en los años setenta y ochenta se habían realizado relativamente pocos estudios sobre género y derecho a la tierra, y casi no se había prestado atención a las implicaciones de género de la contrarreforma agraria neoliberal". ...

  11. Estudio de la estructura cortical en la Isla de Tierra del Fuego a partir de datos sismológicos

    OpenAIRE

    Buffoni, C.; Schimmel, Martin; Sabbione, N.C.; Rosa, M.L.

    2012-01-01

    La Isla de Tierra del Fuego (TdF) se encuentra ubicada en el extremo sur de la Cuenca de Magallanes, donde el borde transformante entre la Placa de Scotia y la Sudamericana define el Sistema de Fallas Magallanes-Fagnano (MFS), cuya falla principal tiene un movimiento sinestral. Con el fin de obtener información de la corteza, se realizó un análisis de funciones receptoras (FR) a partir de datos registrados en cinco estaciones sismológicas instaladas en la Isla. Una FR es el resultado de un pr...

  12. Tierra y negocios en Salta a fines del siglo XIX y principios del XX. Estudio de casos

    OpenAIRE

    del Valle Michel, Azucena; Parrón, Mario Gustavo; Corregidor, Blanca Esther

    2017-01-01

    El trabajo analiza las estrategias desarrolladas por Vicente Arquati y Paulino Echazú en diferentes espacios socioeconómicos de la provincia de Salta, entre fines del siglo XIX y principios del XX. Las mismas, posibilitaron la concentración de tierras, la comercialización de productos y otras actividades lucrativas. Sobre estas cuestiones se plantean interrogantes para identificar los factores explicativos de la imposibilidad de esos sujetos de mantener sus logros económicos, a pesar de haber...

  13. Difference fractal surfaces poured earth floors Tamaulipas / Diferencia fractal en superficies de tierra vertida con suelo de Tamaulipas

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez Dominguez

    2013-09-01

    Full Text Available Poured earth is a sustainable construction and economically feasible technique to develop in Tamaulipas, by the materials availability and traditional manufacturing procedures uses. There are several variables to be considered in these elements for their properties, among them it can be found roughness and porosity analysis which are important because they are related to material mechanical resistance and durability. This study aimed to characterize solid surfaces using fractal dimension to know its uniformity and porosity, compared with a concrete surface. Solids were obtained from poured earth of two combinations of soils stabilized with cement from the state of Tamaulipas. We found that a surface of a sample, obtained with ground, is more uniform than poured concrete surface, and that fractal dimension is higher while porosity increases; results suggest that this is because of the presence of clay in the poured earth mixtures. La tierra vertida es una técnica constructiva sustentable y económicamente viable para desarrollarse en Tamaulipas, por la disponibilidad de materiales y procedimientos de fabricación similares a los tradicionales. Son diversas las variables que deben estudiarse en estos elementos para conocer sus propiedades, entre las que se encuentran la rugosidad y la porosidad, las cuales son importantes debido a su estrecha relación con la resistencia mecánica y durabilidad del material estudiado. El presente trabajo tuvo por objetivo caracterizar superficies sólidas a partir de la dimensión fractal para conocer su uniformidad y porosidad, comparándola con una superficie de concreto. Los sólidos fueron obtenidos a partir de tierra vertida conformada de dos combinaciones de suelos estabilizadas con cemento provenientes del estado de Tamaulipas. Se encontró que una superficie de tierra vertida es menos irregular que una superficie de concreto además de tener una menor porosidad reflejada en una menor dimensión fractal

  14. Tenencia de la tierra y desarrollo rural sostenible: algunos puntos para la reflexión en el caso venezolano.

    OpenAIRE

    Delahaye, Olivier

    2007-01-01

    1.- Artículos Tenencia de la tierra y desarrollo rural sostenible: algunos puntos para la reflexión en el caso venezolano. Land tenure and sustained rural development: points for reflecting on the Venezuelan case. Tenure de la terre et développement rural durable : quelques points pour la réflexion dans le cas du Venezuela. Delahaye, Olivier Paradigmas del mercado financiero rural en países en desarrollo. Paradigms in the rural financial markets in developing countries. ...

  15. Acceso a la tierra de los ex huasipungueros en la hacienda "Carpuela", en el valle del Chota.

    OpenAIRE

    Villa Zura, Marco Patricio

    2015-01-01

    El propo?sito del presente estudio de investigacio?n es abordar como fue el acceso a la tierra de los ex huasipungueros en la hacienda Carpuela en el Valle del Chota, parroquia Ambuqui?, canto?n Ibarra, Provincia de Imbabura, quienes fortalecieron la organizacio?n comunitaria, apoya?ndose en la Ley de Reforma Agraria, ejecutada por el Instituto Ecuatoriano de Reforma Agraria y Colonizacio?n de 1964 y la de 1973 que continuo. Adema?s autores teo?ricos reflejan la historia de los jesuitas qu...

  16. Cultivable microflora and endo mycorrhizas obtained in litter forest (Paramo Guerrero - Finca Puente de Tierra) Zipaquira, Colombia

    International Nuclear Information System (INIS)

    Bernal, Eleonora; Celis, Sebastian; Galindez, Ximena; Moratto, Claudia; Sanchez, Jimena; Garcia, Daniel

    2006-01-01

    The count of cultivable microorganisms (bacteria and fungi), cellulolytic microorganisms and endo mycorrhizas present in litter forest (property Puente de Tierra) in the Guerrero's moor, Colombia was made. The most frequently isolated microorganisms belonged to the staphylococcus, bacillus, pseudomonas, micrococcus, penicillium and rhodotorulagenus and cladosporium sp., which is a cellulolytic microorganism, was isolated in carboxymethyl cellulose agar. In addition eight morphotypes of endomycorrhizas were found, species of glomus and acaulospora predominated among them. This study contributes with the knowledge of the cultivable microorganisms of litter that have been little explored in moor ecosystems

  17. Forestaciones en tierras agrarias de la Región de Murcia : cambios medioambientales y paisajísticos

    OpenAIRE

    González Botía, Miguel Ángel

    2017-01-01

    El objetivo principal de esta tesis ha sido el estudio de las consecuencias derivadas de las forestaciones de tierras agrarias abandonadas en la Región de Murcia (FOTARM), considerada una medida agroambiental de la PAC, que pretende paliar los graves problemas de erosión, degradación y desertificación, derivados de dicho abandono. Primeramente se ha realizado un minucioso análisis de las forestaciones, que se llevaron a cabo en dos periodos: el primero (y principal) de 1994 a 1999, (llegando ...

  18. Spark Channels

    Energy Technology Data Exchange (ETDEWEB)

    Haydon, S. C. [Department of Physics, University of New England, Armidale, NSW (Australia)

    1968-04-15

    A brief summary is given of the principal methods used for initiating spark channels and the various highly time-resolved techniques developed recently for studies with nanosecond resolution. The importance of the percentage overvoltage in determining the early history and subsequent development of the various phases of the growth of the spark channel is discussed. An account is then given of the recent photographic, oscillographic and spectroscopic investigations of spark channels initiated by co-axial cable discharges of spark gaps at low [{approx} 1%] overvoltages. The phenomena observed in the development of the immediate post-breakdown phase, the diffuse glow structure, the growth of the luminous filament and the final formation of the spark channel in hydrogen are described. A brief account is also given of the salient features emerging from corresponding studies of highly overvolted spark gaps in which the spark channel develops from single avalanche conditions. The essential differences between the two types of channel formation are summarized and possible explanations of the general features are indicated. (author)

  19. Cambio del uso de la tierra y pérdida de la cobertura boscosa, comunidades agrarias Sechina, La Ensenada y Cerro San Gil, Izabal Guatemala

    Directory of Open Access Journals (Sweden)

    Eddi Alejandro Vanegas Chacón

    2016-07-01

    Full Text Available En Guatemala, pocas temáticas son abordadas con tanta pasión como el acceso a la tierra y sus relaciones de productividad. Ante el juicio histórico y la evidencia de las estadísticas se deslumbra que las políticas agrarias de los últimos cincuenta años, si bien mitigaron la pobreza en el agro rural conllevaron con ellas daños ambientales irreversibles y deudas agrarias millonarias. Se estudió la dinámica del cambio de uso de la tierra y la pérdida de la cobertura boscosa en las comunidades agrarias beneficiadas por la Ley de Transformación Agraria, Sechina, La Ensenada y Cerro San Gil ubicadas en el departamento de Izabal. Se utilizó fotointerpretación y se realizaron estudios semidetallados de la intensidad de la tierra para el periodo 1958 a 2010. Se concluyó que bajo las premisas de “mejora a la tierra” de la Ley de Transformación Agraria ocurrió cambio de uso y cobertura de la tierra, de forestal a agropecuaria, en las comunidades agrarias Sechina 42%, La Ensenada 46,2% y Cerro San Gil 48,6%, donde se promovieron sistemas de aprovechamiento agrícola que conllevaron al sobre-uso de las tierras en 42%, 78% y 30%, respectivamente. Esto sugiere, que la adquisición de la tierra no es el fin, más bien es el medio, para promover desarrollo rural sostenible, a través de acompañamiento técnico agropecuario, monitoreo y evaluación tanto económica como ambiental.

  20. Estudios florísticos y ecológicos sobre las algas de agua dulce de turberas de Tierra del Fuego

    OpenAIRE

    Mataloni, María Gabriela

    1994-01-01

    En esta Tesis Doctoral se realizan diversas investigaciones florísticas y ecológicas sobre las algas de turberas de Sphagnum de la provincia de Tierra Fuego. Para ello se condijeron básicamente dos trabajos. en la primera parte se estudiaron ocho ojos de agua pertenecientes a siete turberas ubicadas en el sur de Tierra del Fuego. En cada una de ellas se muestrearon tanto el fitoplancton del agua libre como las algas que viven asociadas a Sphagnum a lo largo de un gradiente ambiental caracteri...

  1. El acaparamiento de tierras como proceso dinámico. Las estrategias de los actores en contextos de estancamiento económico

    OpenAIRE

    Carla Gras; Daniel M. Cáceres

    2017-01-01

    Este artículo pretende contribuir a la comprensión de los procesos de acaparamiento de tierras. A partir de un análisis realizado en el norte de Córdoba (Argentina), se sugiere que dicho fenómeno: (a) no es lineal, uniforme ni se incrementa de manera sostenida en el tiempo; y (b) no se limita a la concentración de tierras sino que integra recursos estratégicos (financieros, tecnológicos, gerenciales) que convergen en el objetivo más general de acaparamiento de capital. Analizamos una dinámica...

  2. El Límite a la Protección de las Tierras Indígenas de la Ley 19.253

    Directory of Open Access Journals (Sweden)

    Mario Salamanca Huenchullán

    Full Text Available Este trabajo aborda el tema del límite a la protección de las tierras indígenas, que como una exigencia del interés nacional introduce en la legislación chilena la Ley Indígena 19.253, en su relación con la expropiación para la construcción de obras públicas, que en virtud de la utilidad pública se construyen sobre estas mismas tierras.

  3. Holocene glacial fluctuations in southern South America

    Science.gov (United States)

    Reynhout, S.; Sagredo, E. A.; Kaplan, M. R.; Aravena, J. C.; Martini, M. A.; Strelin, J. A.; Schaefer, J. M.

    2016-12-01

    Understanding the timing and magnitude of former glacier fluctuations is critical to decipher long-term climatic trends and to unravel both natural cycles and human impact on the current glacial behavior. Despite more than seven decades of research efforts, a unifying model of Holocene glacial fluctuations in Southern South America remains elusive. Here, we present the state-of-the-art regarding the timing of Holocene glacial fluctuation in southern Patagonia-Tierra del Fuego, with a focus on a new generation of high-resolution radiocarbon and 10Be surface exposure dating chronologies. Recently acquired evidence suggest that after receding from advanced Late Glacial positions, Patagonian glaciers were for the most part close to, or even behind, present ice margins during the Early Holocene. On the other hand, emerging chronologies indicate that in some areas there were extensive expansions (century scale?) that punctuated the warm interval. Subsequently, we have evidence of multiple millennial timescale glacial advances starting in the middle Holocene. Several glacial maxima are defined by moraines and other landforms from 7000 years ago to the 19th century, with a gap sometime between 4,500 and 2,500 years ago. The last set of advances began around 800-600 years ago. Although glacial activity is documented in Patagonia at the same time as the European Little Ice Age, the extent of these glacial events are less prominent than those of the mid-Holocene. The causes that may explain these glacial fluctuations remain elusive. Finally, we discuss ongoing efforts to better define the timing and extent of Holocene glaciations in southern South America, and to establish the basis to test competing hypothesis of regional Holocene climate variability.

  4. Evaluación del efecto insecticida de tierra de diatomeas sobre Triatoma infestans (Hemíptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    Mariana L Bilbao

    2007-04-01

    Full Text Available El Triatoma infestans es el principal vector de la enfermedad de Chagas en Argentina. La tierra de diatomeas (TD es un producto natural que se comercializa actualmente con fines insecticidas y que produce la muerte por deshidratación. Se evaluó la eficacia insecticida de TD al 60% de pureza, proveniente del yacimiento La Iglesiana (San Juan, Argentina sobre ninfas V y adultos de T.infestans. Se ensayaron dos dosis: 112,5 g/m2 (T1 y 225 g/m2 (T2, con cuatro réplicas por tratamiento, con cinco ejemplares, incluyendo los controles (TC en el laboratorio. Se contaron los individuos vivos y muertos durante cinco días. No se encontró diferencias en la mortalidad (ANOVA, p>0,05 en los adultos (T1: 40%, T2: 25% y TC: 30% ni en las ninfas V (T1: 10%, T2: 15% y TC: 10%. Se concluye que la tierra de diatomeas del yacimiento La Iglesiana, en las condiciones de laboratorio evaluadas, no posee capacidad insecticida sobre T.infestans.

  5. Crecimiento ganadero y ocupación de tierras públicas, causas de conflictividad en la frontera bonaerense

    Directory of Open Access Journals (Sweden)

    Fernando Enrique Barba

    2007-01-01

    Full Text Available Sin dudas, la forma más visible de violencia practicada en la frontera de Buenos Aires durante los siglos XVIII y XIX fue la guerra entre el blanco y las diferentes parcialidades indígenas. Si bien puede afirmarse en sentido amplio que dicha guerra fue permanente, esta se intensificó en momentos determinados coincidentes con lo que podemos calificar, en rasgos generales, períodos de expansión ganadera. La presente colaboración intenta señalar entonces cuatro momentos en el proceso de expansión ganadera cuyas características generales fueron el aumento de los rebaños y ocupación de nuevas tierras, siendo estos hechos seguidos por la reacción de los indios quienes incrementaron los malones, pequeños en general y eventualmente masivos, en busca de los ganados de todo tipo existentes en las estancias bonaerenses. Los cuatro períodos a estudiar son: 1º a partir de las últimas vaquerías (1718; 2º la formación del virreinato y las nuevas condiciones de comercio; 3º la expansión ganadera a partir de 1810 y la ocupación de tierras más allá del Salado y 4º y el gran crecimiento a partir de Caseros

  6. Plan de manejo sostenible de tierra para la producción de leche en la UBPC Aguadita, Cienfuegos, Cuba

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    Eligia de la C Cuellar

    Full Text Available Se realizó un estudio en la UBPC Aguadita, del municipio Rodas _provincia Cienfuegos, Cuba_, con el objetivo de elaborar un plan de manejo sostenible del suelo para incrementar la producción de leche. Se utilizó la guía contenida en el manual de procedimientos para la implementación del manejo sostenible de tierra. Los pasos de la guía permitieron concebir una investigación no experimental, de tipo correlacional/múltiple, en la que se utilizaron métodos teóricos y prácticos con sus correspondientes técnicas (entrevistas, encuestas, revisión documental, observación directa; y se realizaron mediciones en el lugar, con la aplicación de diez herramientas metodológicas. Se demostró que la baja producción de leche en la UBPC es causada fundamentalmente por la degradación de los suelos, la mala calidad de los pastos y la deficiente gestión del conocimiento, lo que coincide con la principal barrera para la aplicación del manejo sostenible de tierra. A partir de estos resultados se elaboró el plan de manejo sostenible, como herramienta que contribuye a desarrollar acciones que mitiguen el impacto negativo de la degradación de suelos en el rendimiento lechero de la unidad.

  7. MARKETING CHANNELS

    Directory of Open Access Journals (Sweden)

    Ljiljana Stošić Mihajlović

    2014-07-01

    Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.

  8. Checklist of the Discomycetes (Fungi of Patagonia, Tierra del Fuego and adjacent antarctic areas

    Directory of Open Access Journals (Sweden)

    Irma J. Gamundí

    2004-01-01

    Full Text Available La información brindada en este catálogo consiste en registrar las especies de hongos pertenecientes a los órdenes Cyttariales, Helotiales, Ostropales, Pezizales, Rhytismatales y Thelebolales (Discomycetes coleccionadas en Patagonia, Tierra del Fuego y áreas adyacentes antárticas (Patagonia. Además datos sobre sus organismos asociados fueron localizados, resumidos, validados y editados. Las fuentes de información fueron las exsiccatae depositadas en colecciones de Argentina y otros países y de las publicaciones listadas en la bibliografía. Otros registros derivaron de observaciones de campo sobre material fresco y colecciones de referencia. La información fue acumulada en un sistema computarizado relacional de datos taxonómicos, nomenclaturales, bibliográficos, de distribución geográfica y de observaciones biológicas. Este sistema permite la acumulación de datos paralelos en diferentes idiomas, y distingue la información original de la opinión corriente de lo que puede significar esa información. En la Biological Records Database, 5029 registros fueron creados para observaciones sobre la ocurrencia temporal y espacial de los organismos vivos de la región. De éstos, 2613 corresponden a registros de colecciones de Discomycetes de la Patagonia y Tierra del Fuego, con la siguiente distribución: 1854 para a la Argentina, 687 para Chile y 72 para áreas adyacentes antárticas. Excluyendo los sinónimos, los Discomycetes están representados por 361 especies y taxones subespecíficos (160 géneros, 22 familias y 7 órdenes. Los registros remanentes fueron de organismos asociados con los Discomycetes: 163 animales (8 especies, 8 géneros, 6 familias y 5 órdenes; 2 Chromista; 223 hongos (52 especies, 54 géneros, 26 familias y 13 ódenes; 2028 plantas (159 especies, 122 géneros, 59 familias y 39 órdenes. Cada uno de estos taxones (y cada sinónimo conocido está representado por un registro separado en la Base de Datos Taxon

  9. Modelo para evaluar la calidad de las tierras: caso del cultivo de papa

    Directory of Open Access Journals (Sweden)

    Martínez Luis Joel

    2006-06-01

    Hidden="false" UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" />

    Dentro de la busqueda de la sostenibilidad y la competitividad de la agricultura, la evaluacion de la calidad de las tierras es un aspecto basico que permite tomar decisiones sobre  las areas mas apropiadas para ubicar los cultivos y sobre los procesos de degradación de las tierras, con el fin de tomar medidas para su manejo y conservacion. En esta investigacion se

  10. Expansión estatal, política de tierras y desarrollo de la repartición topográfica en Buenos Aires, siglo XIX

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    Valeria Araceli D'Agostino

    2014-11-01

    Full Text Available Este artículo aborda la política de tierras del Estado provincial bonaerensey su relación con el proceso de conformación de la repartición topográfi ca,tomando como punto de partida el contexto de expansión territorial y deincorporación de tierras a la economía provincial abierto luego de la rupturadel vínculo colonial. Se considera que la centralidad de la problemática dela tierra en este contexto impulsó la temprana organización de la reparticióndestinada a: realizar las tareas de reconocimiento, mensura y delimitación delos territorios de dominio público y privado, elaborar un catastro territorial,controlar el traspaso de tierras públicas a particulares, perfeccionar el trazadode pueblos y ejidos y regular las actividades de los agentes encargados de lasmismas, entre otras.

  11. Organización territorial y distribución de la tierra en la comunidad de San Felipe Otlaltepec, Puebla, México

    Directory of Open Access Journals (Sweden)

    Jesús García Maceda

    2014-01-01

    Full Text Available San Felipe Otlaltepec, una comunidad indígena Popoloca del estado de Puebla, organiza su territorio en secciones, una unidad territorial colonial. Esta organización es la base de la apropiación del territorio urbano y de las tierras agrícolas. Con entrevistas y fotografías aéreas, se construyó un modelo de la conformación original y actual de las viviendas de las secciones y de la apropiación de la tierra, para su comparación. Actualmente, se observa una mezcla de viviendas de diferentes secciones, que no corresponde al arreglo original de las mismas. Situación similar se observó en la distribución de las tierras agrícolas. Estos cambios se deben principalmente a casamientos entre miembros de diferentes secciones, los cuales cambian la posesión de la tierra y la pertenencia a una sección determinada. A pesar de la mezcla de viviendas de diferentes secciones, los entrevistados manifestaron un sentido profundo de pertenencia a la sección a la que pertenecen formalmente.

  12. Regulación en el uso de la tierra con fines preventivos en los alrededores del cuadrante de la antigua comunidad de Cinchona, Alajuela, Costa Rica

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    Esquivel Valverde, Lidier

    2011-07-01

    Full Text Available La regulación del uso de la tierra permite establecer cuales lugares son aptas para el establecimiento de zonas habitacionales, comercios, industria, actividades agrícolas, actividades turísticas, entre otras, evitando incrementar la vulnerabilidad física o ambiental. El presente artículo se basa en un estudio realizado a la comunidad de Cinchona a raíz del sismo del año 2009, el cual, por las características topográficas y geológicas de la región, generó una cantidad alta de daños a la infraestructura y pérdida de vidas humanas, lo que propició la elaboración de una herramienta técnica normativa que regulara el uso de la tierra en esa zona. La investigación consideró aspectos como el uso de la tierra antes del sismo, tenencia de la tierra, producción agropecuaria, valor de la tierra, pendientes de terreno, geomorfología, capacidad de uso de la tierra, aguas subterráneas, zonas de vida y áreas silvestres y por último las amenazas más relevantes. Como resultado del estudio se presenta en el artículo un resumen de la regulación de tierra propuesta, la cual comprende el sector de Vieja Cinchona (zona devastada por el sismo y las microcuencas cercanas Land use regulations allow to identify suitable places to establish housing, commerce, industry, agricultural activities, and tourism, among others, avoiding to increase physical or environmental vulnerability. This article is based on a study developed at the Cinchona community after the 2009 earthquake, which due to the topographic and geological characteristics generated a lot of damages to infrastructures and losses of human lives. In this context, a normative technical tool was developed to regulate the land use in the zone. The investigation considered aspects such as land use before the earthquake, land possession, farming production, land value, land slopes, geomorphology, land use capacity, underground water, wild life areas and most relevant threats. As a result of

  13. Historia y memoria campesina: silencios y representaciones sobre la lucha por la tierra y la represión en Ongoy

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    Guido Chati

    2015-01-01

    Full Text Available Este artículo sostiene que hay espacios sociales en Perú donde se producen memorias alternativas sobre la violencia política que tuvo lugar entre 1980 y 2000. En Andahuaylas, Apurímac, las narrativas recurrentes hablan acerca de la servidumbre en la hacienda, de la movilización campesina por la restitución de sus tierras, la ocupación de tierras y sobre su violenta represión. Existe esta memoria victoriosa respecto de la ocupación de la tierra, al lado de una memoria de victimización respecto de la guerra interna. Sin embargo, esas representaciones han sido silenciadas a través de estudios oficiales sobre la memoria, que están tan de moda. En Ongoy, Andahuaylas, bajo la apariencia de un conflicto entre las comunidades y hacienda, se encuentran prácticas políticas campesinas en relación con el Estado. Los campesinos desarrollan redes con las instituciones del Estado, sindicatos, estudiantes, inmigrantes, partidos políticos y otros en busca de la restitución de sus tierras. Reúnen documentos que utilizan como apoyo de su memoria y de su precedencia en el territorio. Ellos muestran que la lucha por la tierra que relativamente termina en 1963 con la ocupación de la tierra, la masacre de los campesinos y la represión, tiene orígenes coloniales. Son historias y recuerdos que reconstruyen la lucha por la tierra como un acto heroico y se superponen con otras representaciones más recientes de la violencia política. Para analizar el proceso, reconstruyo lo ocurrido en Ongoy entre 1960 y 1969 en diálogo con los documentos que los campesinos reunieron y con los testimonios de los actores sobre la forma en que se da una lectura posterior a la violencia política.

  14. Evaluación de la tasa de infiltración en tierras agrícolas, forestales y de pastoreo en la subcuenca del río Shullcas

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    Guillermo Carlos Gómez

    2014-06-01

    Full Text Available Objetivos: Evaluar y determinar el uso del suelo con mayor tasa de infiltración en la subcuenca del río Shullcas en Huancayo. Métodos: Se desarrolló una investigación básica con diseño correlacional. Los usos actuales de la tierra fueron identificadas y demarcadas, según la normativa peruana de clasificación de tierras por su capacidad de uso mayor; en estas zonas se seleccionó 31 puntos de muestreo al azar usando las herramientas de software ArcGIS, en los que se midieron la infiltración empleando infiltrómetros de doble anillo, se registraron los tipos de cobertura vegetal y se tomaron muestras de suelo para analizar sus contenidos de arcilla, arena, limo y humedad; asimismo densidad aparente y porosidad en laboratorio. Resultados: Las tasas de infiltración promedio, según el tipo de uso de tierras, fueron: 14,04 cm/h para las tierras forestales; 12,42 cm/h para las tierras agrícolas y 2,07 cm/h para las tierras de pastoreo; además, solo el 12,63% de la subcuenca del río Shullcas tiene infiltración mayor a 0,2 cm/h. Conclusiones: No existe diferencia estadística significativa entre la tasa de infiltración de tierras forestales y agrícolas, pero si existe diferencias de la tasa de infiltración de tierras forestales y agrícolas respecto a la tasa de infiltración de tierras de pastoreo.

  15. Channel Power in Multi-Channel Environments

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); B. Skiera (Bernd)

    2004-01-01

    textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

  16. El movimiento de los trabajadores rurales sin tierra y la reforma agraria en Brasil

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    Lorenzo FERNÁNDEZ FRANCO

    2009-11-01

    Full Text Available RESUMEN: Este artículo, es un primer avance, de carácter exploratorio, de una investigación más amplia que el autor está llevando a cabo sobre el mismo tema. Centrado en el "Movimiento de los Trabajadores Rurales sin Tierra", habitualmente identificado en Brasil por las siglas MST, se contempla dicho movimiento social desde sus orígenes más remotos, al final de los años 50, hasta nuestros días situándolo, por un lado, en las transformaciones políticas y en parte sociales, y en el largo y lento proceso de una reforma agraria inconclusa, por otro. De forma descriptiva, se desarrollan, en un primer paso, los antecedentes, proceso de constitución, etapas y estructura agraria brasileña, se plantea de forma suscinta la problemática de la reforma agraria. Con estas consideraciones preliminares, siguiendo casi literalmente la formulación del propio MST, se exponen, con mayor amplitud, los objetivos y características de la Reforma Agraria desde la perspectiva de los propios trabajadores rurales. Asimismo, aunque de forma más esquemática y en base a los datos oficiales, se plantean las directrices, metas y algunas de las realizaciones del Gobierno de Fernando H. Cardoso sobre dicha reforma. En definitiva, con este artículo, se pretenden establecer las bases y los ejes analíticos necesarios para una investigación más amplia y comprensiva de este fenómeno social de masas que va más allá de la propia realidad de injusticia que se está viviendo en el mundo rural brasileño y que está contando también con un amplio y sorprendente apoyo de sectores urbanos de la población brasileña.ABSTRACT: This article is an introductory and exploratory advance of a more extensive investigation that the author is carrying out on the same subject. The research is centred on the "Movement of the Rural Workers without Land", which is ussually identified in Brazil with the initials MST. This social movement is analyzed since its remotest origins, the

  17. Southern blotting.

    Science.gov (United States)

    Brown, T

    2001-05-01

    Southern blotting is the transfer of DNA fragments from an electrophoresis gel to a membrane support (the properties and advantages of the different types of membrane, transfer buffer, and transfer method are discussed in detail), resulting in immobilization of the DNA fragments, so the membrane carries a semipermanent reproduction of the banding pattern of the gel. After immobilization, the DNA can be subjected to hybridization analysis, enabling bands with sequence similarity to a labeled probe to be identified. This appendix describes Southern blotting via upward capillary transfer of DNA from an agarose gel onto a nylon or nitrocellulose membrane, using a high-salt transfer buffer to promote binding of DNA to the membrane. With the high-salt buffer, the DNA becomes bound to the membrane during transfer but not permanently immobilized. Immobilization is achieved by UV irradiation (for nylon) or baking (for nitrocellulose). A Support Protocol describes how to calibrate a UV transilluminator for optimal UV irradiation of a nylon membrane. An alternate protocol details transfer using nylon membranes and an alkaline buffer, and is primarily used with positively charged nylon membranes. The advantage of this combination is that no post-transfer immobilization step is required, as the positively charged membrane binds DNA irreversibly under alkaline transfer conditions. The method can also be used with neutral nylon membranes but less DNA will be retained. A second alternate protocol describes a transfer method based on a different transfer-stack setup. The traditional method of upward capillary transfer of DNA from gel to membrane described in the first basic and alternate protocols has certain disadvantages, notably the fact that the gel can become crushed by the weighted filter papers and paper towels that are laid on top of it. This slows down the blotting process and may reduce the amount of DNA that can be transferred. The downward capillary method described in

  18. LA MOVILIZACIÓN DE LOS GARÍFUNAS PARA PRESERVAR SUS TIERRAS «ANCESTRALES» EN GUATEMALA

    OpenAIRE

    Nicolás Rey

    2009-01-01

    Livingston, en el noreste de Guatemala, es la «ciudad negra» de ese país que cuenta con una población de mayoría maya. Los derechos de los garífunas, mayas y xincas —recuperación de tierras ancestrales, valorización de su identidad y desarrollo socioeconómico— fueron inscritos en los Acuerdos de Paz, 1995-1996. Este artículo, resultado de una amplia investigación, presenta la increíble trayectoria de los garífunas: - un pueblo «en resistencia» nacido en las Antillas Menores, del encuentr...

  19. La tierra urbana en el portafolio de las fortunas antioqueñas en la primera mitad del siglo XX

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    Fernando Botero

    1992-07-01

    Full Text Available La tesis principal, motivo de debate abierto que se plantea con este ensayo, tiene que ver con el papel que la tierra urbana tuvo en el conjunto de las fortunas antioqueñas. A su vez, esta temática sirve como puente para conectar los negocios a la historia urbana y ayudar a iluminar el debate en torno a la acumulación de capital en Antioquia. De esta forma la polémica sirve como pretexto y telón de fondo para exponer algunas tesis alternativas y proponer una nueva ventana para leer nuestro pasado y recuperar la memoria perdida que constituye el gran potencial y la esperanza para construir nuestro futuro.

  20. El acaparamiento de las tierras a gran escala en el mundo. El papel de las firmas multinacionales (Internacional)

    OpenAIRE

    Perdriault, Mathieu

    2011-01-01

    En los años 2007 y 2008, los medios de comunicación se hicieron eco, de manera creciente, de la adquisición –por intereses públicos o privados–, de los derechos de propiedad sobre grandes extensiones de tierra, especialmente en África, América y Europa del Este. Los miembros de la ONG GRAIN están entre los primeros que han observado la proliferación de artículos de prensa sobre este tema. Se los presentó ante los ojos de la opinión pública mundial, en octubre del 2008, mediante una recopilac...

  1. El Hidróxido de Calcio y los bloques de tierra comprimida, alternativa sostenible de construcción

    Directory of Open Access Journals (Sweden)

    Rubén Salvador Roux Gutiérrez

    2012-01-01

    Full Text Available En la actualidad, en nuestro país se hace mención a que existen una serie de problemas con los programas de vivienda, aún cuando se ha reducido el déficit de vivienda o que se han construido c ada año más viviendas en beneficio de las personas de bajos ingresos. Topelson (2011 el presente artículo describe un estudio sobre una alternativa sustentable de edificación y a la vez pretende demostrar las ventajas del uso del hidróxido de cal y los bl oques de tierra comprimida (BTC, para la edificación de vivienda y así poder reducir las emisones de CO 2 emitidas por los procesos constructivos convenci o nales El presente artículo trata dos materiales elementales en los procesos constructivos de las viv iendas, por un lado se realizá el estudio químico de los morteros cal – arena que se utilizán para el pegado de los mampuestos y los revoques, con la finalidad de determinar la absorción de CO 2 y por otra parte se hace el estudio mecánicos de un materia l alternativo para el uso de muros de carga como son los Bloques de Tierra Comprimida estabilizados con cal, por último se hace un comparativo entre estos materiales alternativos y los convencionales con relación a las emisones de CO2.

  2. Estado y territorio: aportes, desafíos y tensiones en torno a los problemas de tierra en San Juan

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    Margarita Moscheni Bustos

    2015-06-01

    Full Text Available RESUMEN La disputa por la tierra se ha convertido en un tema relevante para la política argentina en el siglo XX. Poseedores históricos, propietarios y desposeídos son los actores que participan en la trama. Atravesando el juego, se encuentra el Estado en sus distintos niveles, que con cierta autonomía relativa, regula a favor de unos y en detrimento de otros. Este trabajo se propone aportar datos empíricos sobre algunas tensiones territoriales en la provincia de San Juan y el rol del Estado y sus contradicciones en los distintos niveles. El caso gira en torno a la disputa por la tierra, generando tensiones políticas entre propiedad privada y propiedad comunitaria, o entre el derecho civil y los derechos emanados de la Constitución Nacional, los Tratados Internacionales y la Ley de Bosques Nativos N° 26.331. ABSTRACT The fight about lands has been became in a relevant situation for the argentine politics in the 20th century, the historic owners, and dispossessed are the most important actors. The state through its different levels has a certain kind of autonomy and regulate and take actions which tend to favor some social groups and damage others. In this work is proposed give some empirical facts about territorial tensions in the province of San Juan, its role and contradictions in its different levels. The case revolves around the land dispute, generating political tensions between private property and communal property, or between civil law and rights arising out of the National Constitution, international treaties and Native Forest Law, No. 26.331.

  3. [Distribution patterns of canopy and understory tree species at local scale in a Tierra Firme forest, the Colombian Amazonia].

    Science.gov (United States)

    Barreto-Silva, Juan Sebastian; López, Dairon Cárdenas; Montoya, Alvaro Javier Duque

    2014-03-01

    The effect of environmental variation on the structure of tree communities in tropical forests is still under debate. There is evidence that in landscapes like Tierra Firme forest, where the environmental gradient decreases at a local level, the effect of soil on the distribution patterns of plant species is minimal, happens to be random or is due to biological processes. In contrast, in studies with different kinds of plants from tropical forests, a greater effect on floristic composition of varying soil and topography has been reported. To assess this, the current study was carried out in a permanent plot of ten hectares in the Amacayacu National Park, Colombian Amazonia. To run the analysis, floristic and environmental variations were obtained according to tree species abundance categories and growth forms. In order to quantify the role played by both environmental filtering and dispersal limitation, the variation of the spatial configuration was included. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the species distribution patterns. The spatial template was evaluated using the Principal Coordinates of Neighbor Matrix method. We recorded 14 074 individuals from 1 053 species and 80 families. The most abundant families were Myristicaceae, Moraceae, Meliaceae, Arecaceae and Lecythidaceae, coinciding with other studies from Northwest Amazonia. Beta diversity was relatively low within the plot. Soils were very poor, had high aluminum concentration and were predominantly clayey. The floristic differences explained along the ten hectares plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on Tierra Firme

  4. Un suelo referible al periodo calido medieval en Patagonia Austral y Tierra del Fuego (Argentina. Aspectos cronologicos y paleoclimaticos

    Directory of Open Access Journals (Sweden)

    Favier Dubois, C. M.

    2002-08-01

    Full Text Available Geoarchaeological work done in Southernmost Patagonia and in the north of Tierra del Fuego, have revealed the recurrent presence of a paedogenesis interval represented by a soil of an A-AC-C profile, with a mollic epipedon, in the upper section of eolian and colluvial deposits of the late Holocene. This soil is today buried in the sites that have been analyzed, while it remains exposed in other areas of the landscape. Radiocarbon dates obtained on materials placed below it (maximum ages and those obtained by OCR (Oxidizable Carbon Ratio in the AC horizon of this soil (minimum ages, indicate the beginning of its development around the year 1000 BP. Its chronology and environmental implications suggest a relationship with the medieval climatic fluctuations called Medieval Warm Period or Medieval Optimum in Europe. This period has correlates detected in Patagonia by dendroclimatic studies.Estudios geoarqueológicos realizados en 5 localidades de Patagonia austral y norte Tierra del Fuego han revelado la recurrente presencia de un suelo de perfil A-AC-C, de epipedon mólico, en depósitos eólicos y coluviales del Holoceno tardío. Este suelo se observa sepultado en los yacimientos arqueológicos analizados, mientras que permanece expuesto en otras posiciones del paisaje. Numerosas edades máximas y mínimas obtenidas por 14C y por la técnica de OCR (Oxidizable Carbon Ratio indican el comienzo de su desarrollo hacia el 1000 AP. Su cronología e implicancias ambientales permiten vincularlo con fluctuaciones climáticas desarrolladas durante el denominado Período Cálido Medieval u Optimo Medieval Europeo, con correlatos detectados en Patagonia a través de estudios dendroclimáticos.

  5. Inferencias paleodietarias mediante isótopos estables en restos óseos humanos provenientes de Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Schinder, Gala

    2003-01-01

    Full Text Available Las actuales lineas de acción vinculadas al uso de isótopos estables en la Isla Grande de Tierra del Fuego están orientándose a acotar factores de variación (especialmente la variación espacial y temporal y al cruce con otras lineas de evidencias como los estilos de vida. A partir de la ocupación europea en el Siglo XVIII se modificó el estilo de vida de las poblaciones históricas de la región. El presente trabajo tiene como objetivos explorar la variabilidad en cuanto al tipo de recursos consurnidos por hombres y mujeres a partir de la información isotópica obtenida de huesos de individuos provenientes de diferentes sectores geográficos (Norte, Sudeste y Beagle y la determinación de la composición de la dieta en términos de contenido proteico. Los datos isotópicos se complementaron con información etnográfica. El análisis Kruskal-Wallis sugiere que existen diferencias significativas entre los diferentes sectores geográficos, pero no se registraron diferencias significativas entre hombres y mujeres. Asimismo, los isótopos indican que los individuos del Sudeste consumían preferentemente dietas más ricas en proteínas que sus vecinos del norte de la Isla. En los últimos años, ha crecido el interé por los estudios orientados al análisis de la división sexual del trabajo en sociedades cazadoras recolectoras. Este trabajo constituye un primer aporte para evaluar la variabilidad en cuanto a las diferencias en la obtención de recursos entre sexos y el tipo de dieta en individuos históricos de Tierra del Fuego.

  6. El proyecto de restitución de tierras en Colombia: ¿ilustración de la fuerza civilizadora de la hipocresía?

    Directory of Open Access Journals (Sweden)

    Maria Paula Saffon

    2010-12-01

    Full Text Available El presente artículo ofrece una interpretación teórica acerca de las disposiciones sobre restitución de tierras contenidas en la famosa “Ley de Víctimas”, la cual fue debatida en el Congreso colombiano en el año 2008. El proyecto de ley preveía mecanismos específicos encaminados a garantizar la restitución de tierras a las víctimas del conflicto armado colombiano. En su momento, el proyecto de ley fue respaldado por los principales actores políticos del país, incluyendo el gobierno y las élites que lo apoyaban, por un lado, y las organizaciones de víctimas y de derechos humanos y los grupos de oposición, por el otro. El hecho de que todos los actores políticos del país estuviesen considerando seriamente la posibilidad de restituir las tierras a las víctimas del conflicto armado colombiano parecía indicar la existencia de un consenso entre actores políticos cuyas posiciones normalmente están enfrentadas, sobre un tema que tradicionalmente ha generado altos niveles de polarización. Le existencia de dicho consenso es desconcertante porque no parece corresponder ni a los intereses ni a la visión de justicia de dichos actores políticos, y además porque la restitución de tierras enfrenta enormes dificultades tanto prácticas como normativas, lo que indica que posiblemente no sea la mejor alternativa para enfrentar la problemática de distribución de tierras en Colombia. El artículo concluye que el respaldo dado por todos los actores al principio de justicia restaurativa podría llevar a su efectiva realización, y consiguientemente generar un resultado que a pesar de (o quizás por no ser intencional, podría contribuir sustancialmente a resolver el problema de la desigual distribución de tierras en Colombia

  7. Construcción sismorresistente en tierra: la gran experiencia contemporánea de la Pontificia Universidad Católica del Perú

    Directory of Open Access Journals (Sweden)

    Blondet, M.

    2011-09-01

    Full Text Available In many developing countries the most common alternative for dwelling construction is building with earth because the material is abundant and cheap. The quality of most traditional earthen construction is very low, because it is done informally, with little or no technical assistance. In seismic areas where earthen construction is common, every time an earthquake occurs, many dwellings collapse, causing considerable economic losses and tragic injuries and deaths. The professional and academic communities in some seismic countries have not remained indifferent to this important problem. Researchers at the Catholic University of Peru (PUCP have been investigating on the construction of earthen buildings in seismic areas for about 40 years and have obtained invaluable results. This article describes the evolution of the knowledge generated at PUCP of reinforced earth, a material composed of earth and compatible reinforcements, with which it is possible to build seismic-resistant constructions.

    En muchos países en vías de desarrollo la alternativa de vivienda más común es la construcción con tierra, pues el material es abundante y barato. La construcción tradicional de viviendas de tierra se realiza informalmente, sin asesoría técnica. Por ello, la calidad de estas construcciones es generalmente muy baja. En zonas sísmicas donde se construye con tierra, cada vez que ocurre un terremoto colapsan muchas construcciones de este material, causando considerables pérdidas económicas y lamentables pérdidas de vidas. Las comunidades académicas y profesionales de algunos países sísmicos no han permanecido impasibles frente a esta grave situación. En el Perú, investigadores de la Pontificia Universidad Católica del Perú (PUCP han venido investigando la construcción con tierra en áreas sísmicas desde hace cerca 40 años y han obtenido invalorables resultados. Este artículo describe la evolución del conocimiento generado en la

  8. Channelling and electromagnetic radiation of channelling particles

    International Nuclear Information System (INIS)

    Kalashnikov, N.

    1983-01-01

    A brief description is presented of the channelling of charged particles between atoms in the crystal lattice. The specificities are discussed of the transverse motion of channelling particles as are the origin and properties of quasi-characteristic radiation of channelling particles which accompany transfers from one band of permissible energies of the transverse motion of channelling particles to the other. (B.S.)

  9. Channel Modeling

    Science.gov (United States)

    Schmitz, Arne; Schinnenburg, Marc; Gross, James; Aguiar, Ana

    For any communication system the Signal-to-Interference-plus-Noise-Ratio of the link is a fundamental metric. Recall (cf. Chapter 9) that the SINR is defined as the ratio between the received power of the signal of interest and the sum of all "disturbing" power sources (i.e. interference and noise). From information theory it is known that a higher SINR increases the maximum possible error-free transmission rate (referred to as Shannon capacity [417] of any communication system and vice versa). Conversely, the higher the SINR, the lower will be the bit error rate in practical systems. While one aspect of the SINR is the sum of all distracting power sources, another issue is the received power. This depends on the transmitted power, the used antennas, possibly on signal processing techniques and ultimately on the channel gain between transmitter and receiver.

  10. Channeling experiment

    International Nuclear Information System (INIS)

    Abelin, H.; Birgersson, L.; Widen, H.; Aagren, T.; Moreno, L.; Neretnieks, I.

    1990-07-01

    Channeling of water flow and tracer transport in real fractures in a granite body at Stripa have been investigated experimentally. The experimental site was located 360 m below the ground level. Two kinds of experiments were performed. In the single hole experiments, 20 cm diameter holes were drilled about 2.5 m into the rock in the plane of the fracture. Specially designed packers were used to inject water into the fracture in 5 cm intervals all along the fracture trace in the hole. The variation of the injection flowrates along the fracture were used to determine the transmissivity variations in the fracture plane. Detailed photographs were taken from inside the hole and the visual fracture aperture was compared with the injection flowrates in the same locations. Geostatistical methods were used to evaluate the results. Five holes were measured in great detail. In addition 7 holes were drilled and scanned by simpler packer systems. A double hole experiment was performed where two parallel holes were drilled in the same fracture plane at nearly 2 m distance. Pressure pulse tests were made between the holes in both directions. Tracers were injected in 5 locations in one hole and monitored for in many locations in the other hole. The single hole experiment and the double hole experiment show that most of the fracture planes are tight but that there are open sections which form connected channels over distances of at least 2 meters. It was also found in the double hole experiment that the investigated fracture was intersected by at least one fracture between the two holes which diverted a large amount of the injected tracers to several distant locations at the tunnel wall. (authours)

  11. Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile

    OpenAIRE

    Raimundo Soto; Felipe Morandé

    1992-01-01

    Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile This note presents previously unpublished data on prices of agricultural land in Chile's central region and houses (both rental and purchasing prices) in Santiago, with the corresponding methodology. As such, it is a follow-up to an Appendix in Morande (1992).

  12. Design of a grounding network in electrical substations. Materials and formulas the most used; Diseno de redes de tierra en subestaciones electricas. Materiales y formulas mas utilizadas

    Energy Technology Data Exchange (ETDEWEB)

    Raull Martin, J. [Facultad de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2000-09-01

    The purpose of this paper is to present a summarized version of the different types of construction of grounding systems, as well as their materials and formulas, which are necessary and useful for the design and building of a grounding network for medium to high voltage facilities. A description is also made of how to determine the electrical resistivity of subsoil layers with different physical characteristics. Several illustrative examples are also solved in the paper. [Spanish] El proposito de este articulo es presentar de manera resumida los diferentes tipos de construccion de los sistemas de tierra, asi como sus materiales y formulas, los cuales son necesarios y utiles para el diseno y edificacion de una red de tierra para instalaciones de mediana y alta tension. Se describe tambien la obtencion de las diferentes resistividades que presenta los terrenos con diversas caracteristicas fisicas. Asimismo, se solucionan ejercicios ilustrativos a lo largo del articulo.

  13. Neutralizar la degradación de las tierras, una aspiración global. ¿Es posible lograrlo en México?

    OpenAIRE

    Armando López Santos

    2016-01-01

    Neutralizar la degradación de las tierras (LDN, por sus siglas en inglés) o equilibrar su deterioro, es un reto planteado por el Comité de Ciencia y Tecnología (CCT) de la Convención de las Naciones Unidas de Lucha Contra la Desertificación (UNCCD, por sus siglas en inglés), de la que México forma parte, es un concepto moderno que va más allá del recurso edáfico, que expresa un objetivo aspiracional global y una meta voluntaria nacional para contrarrestar el avance de la degradación de tierra...

  14. Transient analysis for grounding systems considering the ground ionization; Analisis transitorio de sistemas de puesta a tierra considerando la ionizacion del suelo

    Energy Technology Data Exchange (ETDEWEB)

    Salgado Salgado, Luis Alberto

    2008-06-15

    All electrical installation must have an effective grounding system. The purpose of this grounding system is to provide a low impedance path for draining electric currents generated by faults, switching operations or atmospheric discharges to earth, avoiding damage to people, equipment or installations. High currents drained to ground leads to an electric field which can be capable of breaking down the dielectric strength of the ground. When this happens, the ionization phenomena takes place, which reduce the grounding system impedance and modify its performance. In this thesis, a computational model for evaluating the transient performance of grounding systems subjected to high magnitude and frequency currents is presented. The model is based in a transmission line approach and the grounding system transient analysis is carried out in the frequency domain. The time domain translation is performed by means of the Fast Fourier Inverse Transform (FFIT). The computer model is capable of simulating soil ionization. The computer model developed is used to study the performance of vertical rods and grounding grids of different sizes. In every case, different electric field magnitudes and soil's resistivity were used, currents of different frequency components and magnitude values where used as well. The obtained results presented were compared and validated with other computer model results and measurements published in the literature. [Spanish] Toda instalacion electrica debe contar con un sistema de puesta a tierra efectivo. La finalidad de este sistema es proporcionar un camino de baja impedancia para drenar a tierra las corrientes generadas por fallas, maniobras o fenomenos naturales como las descargas atmosfericas, evitando de esta manera danos a las personas, equipos o instalaciones. Cuando las corrientes drenadas a tierra son de gran magnitud se origina un campo electrico critico capaz de romper la rigidez dielectrica del suelo que rodea los conductores del

  15. Neutralizar la degradación de las tierras, una aspiración global. ¿Es posible lograrlo en México?

    Directory of Open Access Journals (Sweden)

    Armando López Santos

    2016-04-01

    Full Text Available Neutralizar la degradación de las tierras (LDN, por sus siglas en inglés o equilibrar su deterioro, es un reto planteado por el Comité de Ciencia y Tecnología (CCT de la Convención de las Naciones Unidas de Lucha Contra la Desertificación (UNCCD, por sus siglas en inglés, de la que México forma parte, es un concepto moderno que va más allá del recurso edáfico, que expresa un objetivo aspiracional global y una meta voluntaria nacional para contrarrestar el avance de la degradación de tierras al 2030. De ponerse en marcha, implicaría detener o revertir la tendencia de disminución de calidad físico-biótica (agua-suelo-planta-atmósfera que sostiene el funcionamiento de los ecosistemas, de manera que esto permita conseguir un estado de equilibrio suficiente para mantener un nivel de salud ecosistémica y una garantía en la seguridad alimentaria para las generaciones futuras. El objetivo del presente ensayo fue analizar qué posibilidades tiene México para poner en marcha los principios y acciones necesarias para prevenir, detener y revertir el ritmo de degradación de sus tierras. Un breve análisis de las circunstancias, tanto a nivel global como en el contexto nacional, donde se vislumbran dificultades para conciliar la política ambiental con las metas de crecimiento económico o asumir las consecuencias por la sobre-explotación evidente de los recursos territoriales, de lo contrario LDN solo llegará a ser un reto frustrado ante la tendencia de la degradación de las tierras y comprometiendo con ello cada vez más la calidad de vida de las futuras generaciones.

  16. Composición florística de dos bosques (Tierra firme y varzea) en la región de Araracuara, Amazonia Colombiana

    OpenAIRE

    Londoño Vega Ana Catalina; Alvarez Dávila Estéban

    1997-01-01

    Two rain forests of the Araracuara region (Colombian Amazon) are described and compared in terms of vascular terrestrial plant composition. Two 1.8 ha rectangular plots, located in upland (tierra firme) and seasonally flooded (várzea) sites, were sampled for individuals taller than 0.5 m. A total of 1149 species, 347 genera and 98 families were found. Arborescent species comprised 65% of the total at both sites; climbers (woody and herbaceous) contributed 24%, shrubs 8% and terrestrial herbs ...

  17. El acaparamiento de tierras en América Latina y el Caribe visto desde una perspectiva internacional más amplia

    NARCIS (Netherlands)

    S.M. Borras jr. (Saturnino); J.C. Franco (Jennifer); C. Kay (Cristóbal); M. Spoor (Monique)

    2012-01-01

    markdownabstractEste volumen continúa la discusión surgida de los antecedentes recogidos en la investigación presentada en el libro “Dinámicas del mercado de la tierra en América Latina y el Caribe: concentración y extranjerización”, publicado por la Oficina Regional de la FAO en junio de

  18. Cartografía mediante imágenes Landsat de suelos salinos en la tierra de Medina (Valladolid

    Directory of Open Access Journals (Sweden)

    García Rodríguez, M. P.

    2010-07-01

    Full Text Available The main goal of this study is the mapping of saline soils (solonchaks, solonetzs and luvisols with salic phases in «Tierra de Medina» (Valladolid using images of the TM and ETM sensors of the Landsat satellites. The spectral signatures of these soils show very high digital values, which allows to differentiate them from other types of soils and superficial covers. The highest values correspond to those which have salt efflorescences and the lowest values to soils affected by hydromorphic processes. The images obtained with the NDVI do not allow a clear discrimination of saline soils, but they allow to interpret the changes in their use. In these soils the values of NDVI are very low, due to their scarce vegetation. There is a remarkable vegetation reduction between years 1987 and 2001, which implies a structure deterioration and a great loss of vegetal cover; many of soils affected by salinization have not been cultivated any more.

    El objetivo del estudio es cartografiar los suelos salinos (solonchaks, solonetzs y luvisoles con fases sálicas en la Tierra de Medina (Valladolid utilizado imágenes de los sensores TM y ETM de los satélites Landsat. Las signaturas espectrales de estos suelos muestran valores digitales muy altos, lo que permite diferenciarlos de otros tipos de suelos y cubiertas superficiales. Los valores más altos corresponden a los que tienen eflorescencias salinas en superficie y los más bajos a los suelos afectados por hidromorfismo. Las imágenes obtenidas con el NDVI no permiten una clara discriminación de los suelos salinos, pero sí interpretar los cambios en su uso. En estos suelos los valores de NDVI son muy bajos, acordes con su escasa vegetación. Hay un notable descenso entre los años 1987 y 2001, lo que implica un deterioro de su estructura y una gran pérdida de cubierta vegetal; muchos de los suelos afectados por salinización se han dejado de cultivar. [fr] L’objectif de l’étude est

  19. Erosional and depositional contourite features at the transition between the western Scotia Sea and southern South Atlantic Ocean: links with regional water-mass circulation since the Middle Miocene

    Science.gov (United States)

    Pérez, Lara F.; Hernández-Molina, F. Javier; Esteban, Federico D.; Tassone, Alejandro; Piola, Alberto R.; Maldonado, Andrés; Preu, Benedict; Violante, Roberto A.; Lodolo, Emanuele

    2015-08-01

    The aim of the present study was to characterise the morpho-sedimentary features and main stratigraphic stacking pattern off the Tierra del Fuego continental margin, the north-western sector of the Scotia Sea abyssal plain (Yaghan Basin) and the Malvinas/Falkland depression, based on single- and multi-channel seismic profiles. Distinct contourite features were identified within the sedimentary record from the Middle Miocene onwards. Each major drift developed in a water depth range coincident with a particular water mass, contourite terraces on top of some of these drifts being associated with interfaces between water masses. Two major palaeoceanographic changes were identified. One took place in the Middle Miocene with the onset of Antarctic Intermediate Water flow and the enhancement of Circumpolar Deep Water (CDW) flow, coevally with the onset of Weddell Sea Deep Water flow in the Scotia Sea. Another palaeoceanographic change occurred on the abyssal plain of the Yaghan Basin in the Late Miocene as a consequence of the onset of Southeast Pacific Deep Water flow and its complex interaction with the lower branch of the CDW. Interestingly, these two periods of change in bottom currents are coincident with regional tectonic episodes, as well as climate and Antarctic ice sheet oscillations. The results convincingly demonstrate that the identification of contourite features on the present-day seafloor and within the sedimentary record is the key for decoding the circulation of water masses in the past. Nevertheless, further detailed studies, especially the recovery of drill cores, are necessary to establish a more robust chronology of the evolutionary stages at the transition between the western Scotia Sea and the southern South Atlantic Ocean.

  20. Diversity and distribution patterns in high southern latitude sponges.

    Directory of Open Access Journals (Sweden)

    Rachel V Downey

    Full Text Available Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%. Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent

  1. A new form of land concentration in Colombia Una nueva forma de concentración de la tierra en Colombia:la ley 1448 de 2011

    Directory of Open Access Journals (Sweden)

    Juan Pablo Henao Guzmán

    2012-06-01

    Full Text Available This article aims to show how the Law 1448 of 2011, which explains reparation and restitution of victims, and the National Development Plan (NDP 2011-2014 generate land concentration in Colombia. This is due to how the NDP objectives disintegrate the Law 1448 objectives; this phenomenon could be explained using an agency model and the subsequent moral risk issue formed between the State and the victims. Regarding these results, a game-theory model was built, and this effectively concludes that the Law 1448 and the NDP generate land concentration in ColombiaEn este artículo se pretende mostrar, mediante un análisis económico, cómo la Ley 1448 de 2011 (o Ley de Víctimas y Restitución de Tierras, junto al Plan Nacional de Desarrollo (PND 2011-2014, generan concentración de la tierra en Colombia. Esto se debe a que los objetivos del PND terminan disgregando los que busca la Ley 1448, lo cual se explica con el uso de un modelo de agencia y el subsecuente problema de riesgo moral para el Estado y las víctimas del conflicto. A partir de los resultados anteriores se construye un modelo de teoría de juegos, del que se concluye que, efectivamente, la Ley 1448 y el PND generan concentración de la tierra en Colombia.

  2. Producción de biomasa aérea y uso equivalente de la tierra en intercultivos de alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    T. W Pereyra

    Full Text Available Tradicionalmente, el incremento de la productividad se ha asociado al aumento del rendimiento a través del mejoramiento genético y las prácticas de manejo del cultivo. Sin embargo, si se considera la producción por unidad de área y de tiempo, el sistema de intercultivos puede ser otra forma de mejorar la rentabilidad. El objetivo del experimento fue determinar la biomasa producida y el uso equivalente de la tierra en monocultivo e intercultivos de alfalfa (Medicago sativa L. con sorgo sudán (Sorghum sudanense L. y avena (Avena sativa L.. Se determinó la biomasa aérea de todos los tratamientos (expresada por unidad de superficie y el uso equivalente de la tierra. El diseño fue completamente aleatorizado, dispuesto en bloques con dos repeticiones. Los resultados se sometieron a un ANOVA y las medias se compararon mediante la prueba de Duncan, a través del paquete estadístico INFOSTAT. El intercultivo alfalfa-sorgo triplicó la producción de alfalfa en relación con el monocultivo, mientras que alfalfa-avena no superó la producción de alfalfa pura en los meses de invierno. El intercultivo alfalfa-sorgo fue un 57 % más eficiente en el uso de la tierra que sus respectivos monocultivos, mientras que alfalfa-avena no logró superar la unidad.

  3. Persuasión lingüística para la defensa de la tierra: El Título Primordial de Santiago Sula

    Directory of Open Access Journals (Sweden)

    Marta Puente González

    2016-07-01

    Full Text Available Los pueblos de indios de la Nueva España crearon, a fines de la época colonial, una forma de  defender sus territorios ante la amenaza de colonos españoles, criollos y otros indios que usurpaban ilegalmente terrenos e intentaban rentabilizar el control de las tierras. Empezaron a producir un tipo de textos, sus Títulos Primordiales, que presentaban en los juicios para demostrar la titularidad de sus posesiones. No son textos del tipo administrativo, sino que insertan narraciones con los acontecimientos pasados más importantes para la comunidad. Pero principalmente son escritos que fueron pensados para persuadir a los receptores de la veracidad de sus argumentos. Buscaban convencer, en lo lingüístico y textual, para tener efecto en la vida real: que no se les arrebatase sus tierras. En este trabajo se abordará la aproximación a este tipo textual mediante el estudio, desde la pragmática lingüística y el análisis del discurso, del Título Primordial de Santiago Sula, un documento paradigmático del género. Con ello se quiere demostrar que el Título Primordial de Santiago Sulase caracteriza por una estructura argumentativa con un narrador que dispone de distintos tipos de argumentos y otras estrategias textuales para reforzar la única conclusión final: la defensa dela tierra.

  4. Los ocupantes de tierras en la Norpatagonia. Los Inspectores nacionales, el colono ideal y el poblador real al comenzar el siglo XX

    Directory of Open Access Journals (Sweden)

    Blanco, Graciela

    2016-12-01

    Full Text Available El presente trabajo realiza una aproximación a los pobladores que se asentaron en el norte de la Patagonia Argentina, particularmente en el Territorio de Río Negro, a partir de los informes de inspección realizados por funcionarios de la Dirección Nacional de Tierras en los años 1904, 1910 y 1920-21. Estos informes no abarcan la totalidad del territorio, inspeccionándose en esos años distintas zonas, particularmente las destinadas a funcionar como colonias o reservas –Conesa, Choele Choel, Frias, El Cuy, Valcheta-. Los mismos dan cuenta de los pobladores, la forma de tenencia de la tierra, la producción y las inversiones realizadas, clasificando y calificando a los pobladores de acuerdo a diferentes variables. El relato construido por estos inspectores resultaba el insumo más importante a la hora de decidir el acceso a la tierra. Se estudian los informes que estos agentes estatales producían, caracterizando las condiciones del poblamiento y puesta en producción de la región por parte de los pequeños productores de ganado menor o crianceros, complementando esas fuentes con la prensa regional y la producción existente sobre el tema.

  5. «Le Domaine de la Terre», un conjunto de realizaciones-piloto a base de tierra, en L'isle D'abeau (Francia

    Directory of Open Access Journals (Sweden)

    Salas, J.

    1986-02-01

    Full Text Available In this work, some of the experimental housing works (blocks, formwork, mud and straw... built on the outskirts of Lyon (France are presented in a systematic way. The ensemble is called «Le Domaine de la Terre», and eleven different projects are concerned, where a number of institutions and teams of professionals have worked. In its whole it is an excelent exposition at natural scale of the possibilities of mud construction, even though the results are of a great diversity -formal and conceptually- between those diverse projects.Se presentan en el trabajo de forma sistematizada algunas de las realizaciones de viviendas experimentales a base de tierra (bloques, tapial, bloques compactados, tierra-paja.... realizadas en las cercanías de Lyon (Francia y que constituyen el conjunto «Le Domaine de la Terre». Se trata de una realización a base de once proyectos distintos en los que han intervenido un buen número de instituciones, equipos de proyecto y profesionales franceses. Globalmente constituyen una excelente exposición a escala natural de las posibilidades de las construcciones de tierra, aunque los resultados son muy diversos -formal y conceptualmente- entre los distintos proyectos.

  6. EN LA RESIDENCIA EN LA TIERRA, UN “CABALLERO SOLO” VIVE POSEÍDO POR EL DESEO

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    Luis Alfonso Castro Sotelo

    2011-09-01

    Full Text Available A través del análisis textual, palabras clave, estructura, tema y perspectiva de la voz lírica, se pretende rescatar los elementos estéticos e ideológicos del poema "Caballero solo" del libro Residencia en la tierra. Se asume tal poema como evidencia de la transformación en el sistema nerudiano, un poema donde los elementos de lo social conviven y se enfrentan contra el sujeto individual que escribe y padece. En cierto modo, este poema propone una explicación tipo tesis sobre el funcionamiento del deseo, origen y tránsito, y la vida sexual del mundo social que rodea al poeta y que provoca el retorno posible al espacio primigenio del bosque, la naturaleza y los monstruos de la fantasía: después de percibir el sexo en todas partes, el poeta se protege y rodea por los elementos que lo acompañaron en la infancia y, tal vez, formaron parte del paisaje de todos los hombres a la hora del deseo y del sexo.In these pages, the poem "Caballero solo" is seen as a particularly rich discourse for textual analysis. The poem is built up around key words and concepts, an evocative structure, an attractive issue, and a thought provoking perspective, following an undoubtedly Nerudian lyric voice. The focus lies on the aesthetic and ideological elements in "Caballero solo", included in Residencia en la tierra. The poem is seen as evidence of a transformation in the Nerudian system, where the social elements coexist along with and confront the subject who writes and suffers. Emphasis is paid to the way the poem states a thesis regarding the functioning of desires, their origins and evolution, and sexuality in the social world of the poet, the subject. This world provides a possibility of returning to the primitive spaces of nature, the woods, and the monsters of fantasy. After having perceived sexuality everywhere, the poet shelters himself amongst the elements of his infancy, which can be taken as a common human landscape alluding to sex and desire.

  7. LA MOVILIZACIÓN DE LOS GARÍFUNAS PARA PRESERVAR SUS TIERRAS «ANCESTRALES» EN GUATEMALA

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    Nicolás Rey

    2009-12-01

    Full Text Available Livingston, en el noreste de Guatemala, es la «ciudad negra» de ese país que cuenta con una población de mayoría maya. Los derechos de los garífunas, mayas y xincas —recuperación de tierras ancestrales, valorización de su identidad y desarrollo socioeconómico— fueron inscritos en los Acuerdos de Paz, 1995-1996. Este artículo, resultado de una amplia investigación, presenta la increíble trayectoria de los garífunas: - un pueblo «en resistencia» nacido en las Antillas Menores, del encuentro entre indígenas caribes y negros cimarrones durante la colonización y la esclavitud; luego deportado a América Central, - que está reconquistando «espacios» como la tierra, lo político... gracias a una dinámica social compleja que une los vivos a los muertos —culto a los ancestros—, en alianza a veces con otros grupos mayas y ladinos.   ABSTRACT Livingston, in the northeast of Guatemala, is a «black city» in a country with a predominantly Maya population. The rights of the Garinagu, Maya and Xinca—the recovery of their ancestral lands, the value placed on their identity, and socio-economic development—were enshrined in the peace agreements (1995-1996. This article, resulting from an extensive research project, describes the incredible story of the Garinagu: - a people in «resistance» born in the Lesser Antilles from the encounter between Carib Indians and black runaway slaves, during colonization and slavery, later deported to Central America - who are reconquering «spaces» such as land and politics, thanks to a complex social dynamic that links those who are alive to the dead —ancestor worship—, occasionally in conjunction with other groups —Maya, Ladinos—.

  8. De la tierra al suelo: la transformación del paisaje y el nuevo turismo residencial

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    Aledo Tur, Antonio

    2008-02-01

    Full Text Available Residential Tourism has had a main role of speeding up the social and environmental processes of change that took place in Spain during the second half of the last century. This article begins with the description of its main characteristics, its effects at a local level and the different phases of its evolution. A special reference will be made with regard to last phase (2002-2007 which has been nomitaded New Residential Tourism (NRT. NRT is characterized by the appearance of urban megaprojects of thousands of households, with several golf courses and all the services needed. Its goal is to build privatized units of residential leisure, which are autonomous and independent from the territory where they are settled. In this paper there is an underlying reflection about the socio-cultural consequences of the transformation of agricultural land into urban land. A land that is definitely denatured and transformed into urban space for tourism consumption.El turismo residencial ha sido un agente acelerador de los procesos de transformación social y ambiental acaecidos en la España mediterránea durante la segunda mitad del siglo pasado. Este trabajo se inicia con la descripción de sus principales características, sus efectos a escala local y sus diferentes fases evolutivas. Se hará una especial referencia al último período que se ha iniciado en 2002 y que se ha denominado Nuevo Turismo Residencia (NTR. El NTR se caracteriza por la aparición de megaproyectos urbanísticos de miles de viviendas, con varios campos de golf y todos los servicios necesarios para convertirlo en una unidad de ocio residencial privatizada, autónoma e independiente del territorio en el que se instale. En última instancia, en este artículo subyace una reflexión en torno a las consecuencias socioculturales de la transformación de la tierra en suelo ya que éste es el principal recurso del turismo residencial. La tierra ha pasado de entenderse como un espacio para la

  9. QBO Modulation of the Mesopause Gravity Wave Momentum Flux over Tierra del Fuego

    Science.gov (United States)

    De Wit, R. J.; Janches, D.; Fritts, D. C.; Hibbins, R. E.

    2016-01-01

    The interannual variability of the mesosphere and lower thermosphere (MLT) gravity wave momentum flux over southern mid latitudes (53.7degS) has been studied using more than 7 years of meteor radar observations at Ro Grande, Argentina. A modulation, with periods similar to that of the equatorial stratospheric quasi-biennial oscillation (QBO), is observed in the vertical flux of zonal as well as meridional momentum. The QBO signal is largest in the zonal component during summer and is in phase with the stratospheric QBO at 50 hPa (approx. 21 km). The relation between the stratospheric QBO and the QBO modulation in the MLT gravity wave forcing (derived from the divergence of the momentum flux) was found to be consistent with that expected from the Holton-Tan effect coupled to the interhemispheric coupling mechanism. These results provide the first observational support for the existence of the midlatitude gravity wave forcing anomalies as hypothesized in the interhemispheric coupling mechanism.

  10. Purificando la tierra, colonizando el espíritu: conflicto armado y religiosidad en la mítica Marquetalia

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    Andrés Felipe Ospina

    2015-01-01

    Full Text Available El quebrado territorio de la cordillera central en Colombia ha sido el epicentrode luchas políticas, militares y especialmente espirituales en las que el territorioen pugna, la mítica zona de Marquetalia, debate creencias y prácticas, en torno alpoder, la sangre y la tierra. Lógicas de diverso orden que vinculan la lucha armada,la conquista espiritual y la cosmología del pueblo indígena Nasa –que habita en lazona–, ponen acento crítico en una tensa relación que confronta a la vez que vinculael orden político con el actuar religioso. Este trabajo, centrado en las relacionesemergentes de un campo etnográfico, busca dar cuenta de acciones y relaciones quearticulan y condensan tales enfrentamientos, al mismo tiempo que sugiere un marcode interpretación desde las prácticas religiosas que evidencia la forma en que varioselementos del conflicto armado en Colombia tienen como móvil un componenteespiritual.

  11. Martín Sancho (siglos XIV-XVI un despoblado bajomedieval en la tierra de Medellín

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    Julián Clemente Ramos

    2006-08-01

    Full Text Available The Extremaduran village of Martin Sancho is documented for the first time in 1374. In the second half of the fourteenth century, something that may initially have been an individual appropriation has given rise to a concentrated settlement. Its population seems never to have been more than twenty-five. This village had its own district and council, whose only official was the mayor. Its inhabitants were parishioners of the church of San Martin de Medellín. Around the middle of the fifteenth century, Martin Sancho experienced a certain demographic decline, its population no more than 15-20, of whom only a part resided there permanently. This situation appears to have increased the importance of cattle raising, in the context of the relative abundance of grasses and perhaps also the accumulation of properties on the part of qualified members of the village. The violence of the governor of the tierra and future landlord Rodrigo Portocarrero, who appropriates the district, produces rapid depopulation. In the first quarter of the sixteenth century, Medellín manages through a judicial process to integrate it in its public land.

  12. La restitución de la tierra y la prevención del desplazamiento forzado en Colombia

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    Felipe Gómez-Isa

    2010-12-01

    Full Text Available El conflicto armado interno en Colombia se caracteriza por la generación de más de tres millones de desplazados internos, con consecuencias dramáticas desde el punto de vista humanitario y desde la óptica de la protección de sus derechos. En ocasiones, las razones fundamentales de dicho desplazamiento descansan en una dinámica de control y apropiación territorial con fines tanto estratégico-militares como puramente económicos. Los estándares jurídicos de orden interno e internacional establecen el derecho de las víctimas a la restitución de sus viviendas y patrimonio como el “medio preferente” de reparación en casos de desplazamiento, algo que no se está teniendo en cuenta suficientemente por parte de las políticas de atención al desplazamiento del Gobierno colombiano y de diversas instituciones internacionales. Cualquier política integral de reparación a las víctimas debe pasar necesariamente por la reversión del despojo de tierras, territorios y bienes que se ha producido en Colombia al amparo del conflicto armado interno.

  13. Pedagogía de la Tierra: los sujetos del campo y la Enseñanza Superior

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    Fernando José Martins

    2013-07-01

    Full Text Available Resumen: En el contexto de las políticas y prácticas de la enseñanza superior, de manera general, cada vez más atraídas por la lógica de mercado, se intenta en este artículo dar visibilidad a una experiencia en este nivel de enseñanza, que pretende posicionarse en la contracorriente de aquella lógica: la Pedagogía de la Tierra. Bajo la forma de política pública afirmativa, encarada hacia los sujetos del campo, se construye en Brasil un curso especial con características singulares y propias, que ha llamado la atención de los investigadores y de la sociedad civil. Esta experiencia señala elementos significativos que sustentan la definición de políticas y prácticas de una enseñanza superior vinculada a una perspectiva emancipatoria, orientada específicamente a las clases populares. Palabras clave: movimientos sociales, participación, universidad.

  14. La arquitectura de los puestos de pastoreo en las tierras altas del norte argentino (Susques, provincia de Jujuy

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    Jorge Tomasi

    2015-06-01

    Full Text Available En este artículo nos proponemos analizar las características que presentan los puestos de pastoreo en las tierras altas de la provincia de Jujuy, en el noroeste argentino. El análisis considerará las lógicas de emplazamiento, las configuraciones y las materialidades de estos puestos. Tomaremos en cuenta particularmente los sentidos que la topografía tiene en la configuración de la arquitectura doméstica. Estas construcciones tienen un sentido específico en el marco de los sistemas de asentamiento de los grupos pastoriles, en relación con las estrategias de movilidad de las familias junto con los rebaños. El estudio se basa en el material del trabajo de campo etnográfico que se ha venido desarrollando desde el 2004 en la localidad de Susques, el cual ha implicado un relevamiento sistemático de los distintos tipos de asentamiento, en el marco de una investigación sobre las espacialidades y la arquitectura pastoril en los Andes.

  15. Salamanca como referente simbólico: la urbe del siglo XXI en Tierra Violenta de Luciano G. Egido

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    Ana Eva Rodríguez Valentín

    2017-02-01

    Full Text Available El propósito de este artículo es examinar el material simbólico y los vínculos sociales entre la memoria colectiva, la identidad y el espacio de Salamanca, en el siglo XXI a través de la novela, Tierra Violenta, de Luciano G. Egido. Desde esta perspectiva, propongo una lectura del texto que nos ayude a entender cómo las circunstancias políticas y económicas determinan la estructura de la ciudad; que cambia, a su vez,  la vida de sus habitantes. Se trata de una ciudad que, aparentemente, vive en el pasado, pero que no es inmune a los mecanismos que rigen el siglo XXI. En esta aproximación, el texto literario es una fuente de distintas líneas de análisis para entender las temporalidades urbanas y la dialéctica de ambos, el proyecto público y  la herencia urbana.

  16. El arbitrio de tierras de 1622 y el debate sobre las propiedades y los derechos coloniales de los indios

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    Glave, Luis Miguel

    2014-06-01

    Full Text Available This article analyses the 1622 tax on the sale of lands within the context of the broad debate regarding the lawfulness of the sale and composition of properties, initiated at the end of the sixteenth century. The opportunity to press upon the natives’ resources is studied, as well as the defensive measures available to them, while striving to call attention to the dialogue between metropolitan policy – which sought to increase monetary resources in times of need – and discrepancies within the Andean kingdom at a time of legal and administrative changes that attempted to respond to imperial demands.Este artículo analiza un arbitrio sobre la venta de tierras de 1622, situándolo en el extenso debate acerca de la licitud de la enajenación y composición de propiedades comenzado a finales del siglo XVI. Se estudia la coyuntura de presión sobre los recursos de los naturales y las opciones de defensa de los mismos, procurando resaltar el diálogo entre la política metropolitana, que buscaba ampliar recursos monetarios en tiempo de necesidad, y las discrepancias internas del reino andino en pleno proceso de cambios administrativos y legales que intentaban responder a esa demanda imperial.

  17. «En tierra de hombres» (2005. El acoso psicológico en el trabajo

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    Carmen María VIZOSO GÓMEZ

    2016-10-01

    Full Text Available El acoso psicológico en el trabajo está considerado un grave problema en el entorno laboral debido a los efectos negativos que provoca no solo en la convivencia dentro de la empresa y en la productividad de los trabajadores sino también en la salud de la víctima y en el bienestar de su familia. La película En tierra de hombres está inspirada en un caso real de acoso en el trabajo, concretamente de acoso sexual, sufrido por las mujeres que trabajaban en una mina de hierro. Esta situación desembocó en la primera demanda colectiva sobre discriminación sexual. En el presente artículo se analizan las escenas, los diálogos y las características de los personajes para explicar en qué consiste este tipo de acoso. Así, se describe el clima laboral en la empresa, las conductas vejatorias de los acosadores, el proceso de desarrollo del problema hasta que la víctima abandona la empresa, las consecuencias del acoso en diversos ámbitos y también una posible forma de solucionarlo. Por último, se defiende el valor que tiene este film como recurso didáctico para la formación de estudiantes y trabajadores y para la prevención del acoso en el ámbito laboral.

  18. Edipo y Gaia : el tema de la Madre Tierra en el Oráculo de Delfos

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    Ángel Luis Casquillo Fumanal

    2010-01-01

    Full Text Available Cuando el oráculo de Delfos proclamó destino de Edipo el casarse con su madre, éste entendió de forma unívoca que la Pitia se refería a su madre biológica. Pero la equivocidad (y la analogía era una característica propia de Delfos, que empleaba conceptos —como el de madre— de forma ambigua: El término madre en la ideología délfica podía referirse analógicamente a la Madre Tierra. Si Edipo hubiera entendido el oráculo de forma analógica, su destino podría haber sido distinto.When Delphic oracle proclaimed Oedipus;destiny marrying his own mother, he understood in an univocal way that Pythia meant his biological mother. But aequivocity (or analogy was characteristic of Delphi, which employed concepts —as mother— in an ambiguous way. The word mother, in Delphic ideology, could mean Mother Earth. If Oedipus had understood Delphic oracle in an analogical way, his destiny could have been different.

  19. Caracterización de suelos bajo bosques de Nothofagus betuloides (Mirb Blume, en Tierra del Fuego, Chile Characterization of soils of Nothofagus betuloides (Mirb Blume forests, in Tierra del Fuego, Chile

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    VÍCTOR GERDING

    2002-12-01

    Full Text Available En tres sectores de la parte occidental de Tierra del Fuego (54º45'-54º15' S, 68º40'-70º10' O se caracterizó morfológica, física y químicamente los suelos bajo bosques de coigüe de Magallanes (Nothofagus betuloides (Mirb Blume y sus especies asociadas lenga (Nothofagus pumilio (P. et E. Krasser y canelo (Drimys winteri Forst.. Se describieron 85 perfiles de suelo y aproximadamente 250 observaciones con bastón pedológico. Los suelos bajo coigüe de Magallanes eran jóvenes, muy influidos por la actividad volcánica, topografía y clima. Se observó la presencia de los órdenes Spodosol e Iceptisol, principalmente. En general los suelos eran delgados a muy delgados (mayoritariamente entre 10 y 40 cm, con un alto volumen de esqueleto, textura franca, estructura masiva a granular, capacidad de agua aprovechable baja y drenaje externo e interno moderado a lento. Además, presentan una alta acidez (pH 4-5,5, una baja oferta nutricional y muy altos niveles de saturación de aluminio (promedio > 60 %. El mantillo (Oe/Oa presentó condiciones adecuadas para el desarrollo radicular. Existe comúnmente un horizonte blanco (frecuentemente 10 YR 5/1-2 inmediatamente debajo del mantillo, con textura franco limosa y estructura masiva, con arraigamiento muy bajo. Se plantea como hipótesis que este horizonte se originó por depósitos de cenizas volcánicas y procesos de podzolización. Se concluye que la fertilidad de estos suelos es baja debido a limitantes físicas (dificultades de arraigamiento y químicas (acidez, toxicidad de aluminio, baja oferta de basesSoils under coigüe de Magallanes (Nothofagus betuloides (Mirb Blume forests, located in the oriental part of Tierra del Fuego (54º45'-54º15' S, 68º40'-70º10' W, were characterized morphologically, physically and chemically. Associated tree species were lenga (Nothofagus pumilio (P. et E. Krasser and canelo (Drimys winterii Forst.. A total of 85 soil profiles and approximately 250 soil

  20. Citizens and service channels: channel choice and channel management implications

    NARCIS (Netherlands)

    Pieterson, Willem Jan

    2010-01-01

    The arrival of electronic channels in the 1990s has had a huge impact on governmental service delivery. The new channels have led to many new opportunities to improve public service delivery, not only in terms of citizen satisfaction, but also in cost reduction for governmental agencies. However,

  1. Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales from Tierra del Fuego, Argentina

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    Ana C Scorsetti

    2012-06-01

    Full Text Available Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T. cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T. cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4ºC, 12ºC and 24ºC, on different agar media supplemented with the following specific substrates: chitin azure, Tween ® 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4ºC, 12ºC and 24ºC. The suspension was adjusted to a concentration of 1x10 7 conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24°C, the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween® 20 at the lower two incubation temperatures of 4

  2. Comportamiento de comunidades de lombrices de tierra en dos sistemas ganaderos Behavior of earthworm communities in two livestock production systems

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    Saray Sánchez

    2011-09-01

    Full Text Available Con el objetivo de evaluar el comportamiento de comunidades de lombrices de tierra en dos sistemas ganaderos (pastizal de gramíneas y sistema silvopastoril, los cuales se manejaron para la ceba de animales vacunos y la producción de semillas, se realizó una investigación en la Estación Experimental de Pastos y Forrajes «Indio Hatuey», Matanzas. Para el estudio de las comunidades de lombrices se hicieron seis colectas. En cada una de las áreas descritas se tomaron 40 muestras de suelo, según la Metodología del Programa de Investigación Internacional «Biología y Fertilidad del Suelo Tropical». Se encontraron 297 y 740 organismos en el pastizal de gramíneas y en el sistema silvopastoril, respectivamente. La especie Onychochaeta elegans mostró una mayor abundancia proporcional en el pastizal de gramíneas; mientras que en el sistema silvopastoril se encontraron tres especies, de ellas dos típicas de zonas boscosas: Polypheretima elongata y Onychochaeta windlei; la primera tuvo un mayor valor, con diferencias significativas respecto a las especies halladas del género Onychochaeta. Se concluye que la presencia de árboles en pastizales de gramíneas contribuye a estimular los organismos del suelo, en especial las lombrices de tierra, las que desempeñan un papel importante al mejorar no solo los indicadores físicos y químicos de este, sino también como estimuladoras de otros organismos.In order to evaluate the behavior of earthworm communities in two livestock production systems (grassland and silvopastoral system, which were managed for cattle fattening and seed production, a study was conducted at the Experimental Station of Pastures and Forages «Indio Hatuey», Matanzas. For the study of the earthworm communities six collections were made. In each of the described areas 40 soil samples were taken, according to the Methodology of the International Research Program «Tropical Soil Biology and Fertility». In the grassland and

  3. Linking invasive exotic vertebrates and their ecosystem impacts in Tierra del Fuego to test theory and determine action

    Science.gov (United States)

    Valenzuela, Alejandro E. J.; Anderson, Christopher B.; Fasola, Laura; Cabello, José L.

    2014-01-01

    Understanding processes and impacts of biological invasions is fundamental for ecology and management. Recent reviews summarized the mechanisms by which invasive species alter entire ecosystems, but quantitative assessments of these mechanisms are lacking for actual assemblages to determine their relative importance, frequency and patterns. We updated information on introduced vertebrates in the Tierra del Fuego Archipelago (TDF) via an exhaustive literature review and new data to evaluate ecosystem impact mechanisms and provide management recommendations. To date, 24 exotic vertebrates have naturalized in TDF, outnumbering natives nearly 2:1, with the North American beaver (Castor canadensis) and muskrat (Ondatra zibethica) being the most widely distributed species and also impacting the ecosystem through the greatest number of mechanisms. Introduced vertebrates occupied most parts of the archipelago with human-inhabited islands having greater taxa richness. All exotics potentially altered ecosystems by one or more mechanisms: 100% food webs, 92% invasional meltdown, 42% habitat modification, 38% disease or parasite transmission, 21% soil property and disturbance regime changes. Impact to habitat structure was the main clustering criterion for this assemblage. Within the species that physically alter habitats, we found two sub-groups: 1) large herbivores and 2) "others" including beavers and muskrats. Species that did not alter habitat were divided further into those with predatory trophic effects (carnivorous mammals and trout, sub-group 4) and the rest with assorted impacts (sub-group 3). By establishing high quality information on archipelago-wide assemblage, distribution, impacts and mechanisms for exotic vertebrates, we recommend, based on ecological criteria, prioritizing the management of sub-group 2. A secondary priority might be given to the carnivores in sub-group 4, while species in sub-groups 1 and 3 are less urgent. As the first systematic survey of

  4. Rayleigh waves from correlation of seismic noise in Great Island of Tierra del Fuego, Argentina: Constraints on upper crustal structure

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    Carolina Buffoni

    2018-01-01

    Full Text Available In this study, the ambient seismic noise cross-correlation technique is applied to estimate the upper structure of the crust beneath Great Island of Tierra del Fuego (TdF, Argentina, by the analysis of short-period Rayleigh wave group velocities. The island, situated in the southernmost South America, is a key area of investigation among the interaction between the South American and Scotia plates and is considered as a very seismically active one. Through cross-correlating the vertical components of ambient seismic noise registered at four broadband stations in TdF, we were able to extract Rayleigh waves which were used to estimate group velocities in the period band of 2.5–16 s using a time-frequency analysis. Although ambient noise sources are distributed inhomogeneously, robust empirical Green's functions could be recovered from the cross-correlation of 12 months of ambient noise. The observed group velocities were inverted considering a non-linear iterative damped least-squares inversion procedure and several 1-D shear wave velocity models of the upper crust were obtained. According to the inversion results, the S-wave velocity ranges between 1.75 and 3.7 km/s in the first 10 km of crust, depending on the pair of stations considered. These results are in agreement to the major known surface and sub-surface geological and tectonic features known in the area. This study represents the first ambient seismic noise analysis in TdF in order to constraint the upper crust beneath this region. It can also be considered as a successful feasibility study for future analyses with a denser station deployment for a more detailed imaging of structure.

  5. Perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala

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    Dennis Guerra-Centeno

    2017-03-01

    Full Text Available Se describe el perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala a partir del análisis de 305 expedientes de casos atendidos en los hospitales regionales de Escuintla y San Benito, Petén, entre 2008 y 2013. De los 305 casos, 169 correspondieron al Hospital Regional de Escuintla y 136 al Hospital Regional de San Benito Petén. Los casos del Hospital Regional de Escuintla correspondieron a pacientes provenientes de los departamentos de Escuintla, Santa Rosa, Chimaltenango, Retalhuleu, Suchitepéquez, Sacatepéquez, Sololá y Guatemala. Los casos del Hospital Regional de San Benito Petén correspondieron a pacientes provenientes del área centro y norte de Petén, y algunos referidos del área sur. La edad media de la víctima fue 25.2 años. La enfermedad afectó más a hombres (61.3% que a mujeres (38.7%. La mayoría de los afectados (28.3% eran agricultores. Las especies de serpiente que se consignaron en los expedientes con mayor frecuencia fueron Bothrops asper (serpiente barba amarilla en la región norte y Crotalus simus (serpiente cascabel en la región sur. La mayoría de las mordeduras ocurrieron en los miembros inferiores. Los eventos de mordedura ocurrieron durante el día y durante la noche en proporciones similares. El tiempo medio que tarda la víctima en llegar al hospital fue de 5.6 horas. Se describen también otros aspectos epidemiológicos y se discuten las implicaciones ecológicas y sociales de los datos generados.

  6. Construcción e impacto sobre el ambiente: el caso de la tierra y otros materiales

    Directory of Open Access Journals (Sweden)

    Vázquez Espí, Mariano

    2001-02-01

    Full Text Available The assessment of the impact on the environment of the diverse human activities becomes more unavoidable as the signs of the ecological damage become more evident. Here, the relative merit of several formulations for the physical cost of building (embodied energy, exergy cost and matter cost of materials is analysed; it is also analysed the structure of the aggregate physical cost, including the relative evaluation of its more meaningful items. As a way of concrete examples, the energy and matter embodied into different building functions is evaluated depending on the material used (earth, steel, concrete, brick. Lastly, some conclusions about the attributes of a future, "sustainable" building are taken out.Conforme los indicios del deterioro ecológico se hacen más evidentes, la evaluación del impacto sobre el ambiente de las distintas actividades humanas se vuelve más insoslayable. Aquí se analiza el relativo mérito de distintas formulaciones del coste físico de la construcción: energía incorporada, coste exergético y coste material; también la estructura del coste físico agregado, incluyendo la valoración relativa de sus términos más significativos. Como ejemplos concretos, se evalúa la energía y la materia incorporada por distintas funciones constructivas según el material empleado (tierra, acero, ladrillo, hormigón. Finalmente, se extraen algunas conclusiones acerca de las características de una futura construcción "sostenible ".

  7. La formación del mercado de tierras durante la expansión de la frontera bonaerense. Chascomús y Junín, 1860-1890

    Directory of Open Access Journals (Sweden)

    Guillermo Banzato

    2009-04-01

    Full Text Available En este trabajo nos proponemos analizar la formación del mercado de tierras durante la expansión de la frontera de la provincia de Buenos Aires entre 1860 y 1890, a partir de un enfoque local comparado, enfocando la investigación en dos partidos: Chascomús y Junín. Postulamos que la constitución del mercado de tierras en la campaña bonaerense fue un proceso gradual, que se inició apenas comenzaron a poblarse las tierras defendidas por los fuertes de la frontera interior y se establecían ciertas garantías de seguridad para la propiedad privada

  8. Patterns of larval distribution and settlement of Concholepas concholepas (Bruguiere, 1789 (Gastropoda, Muricidae in fjords and channels of southern Chile Patrones de distribución de larvas y asentamiento de Concholepas concholepas (Bruguiere, 1789 (Gastropoda, Muricidae en fiordos y canales del sur de Chile

    Directory of Open Access Journals (Sweden)

    CARLOS MOLINET

    2005-09-01

    Full Text Available The distribution of Concholepas concholepas (Mollusca, Gastropoda, Muricidae is limited to the coasts of Chile and southern Peru. Almost all studies of this gastropod have been carried out in open coastal systems, rather than the fjords and channels of southern Chile, despite the fact that this area represents ca. 95 % of the total coastline in this country. Although there is a large volume of background literature on C. concholepas, almost nothing is published about early larval development under natural conditions, mostly because early veligers have rarely been found in nature. This study is the first attempt to determine the spatial and temporal abundance and size patterns of C. concholepas larvae in their natural environment throughout all of their developmental stages until they settle. Weekly plankton samples were obtained at the surface and at 8 m depth in four locations in southern Chile in combination with temperature and salinity records in each location. Settlement was quantified using artificial substrates in all locations. We have observed that C. concholepas larval development occurs throughout the entire year in Chilean inland seas, with early veliger larvae being released mostly from August to March, reaching the competent stage around June to August, and settling between July and August. Thus, larvae appear to have a long planktonic development that can last between 6 and 12 months. Differences in local hydrology could affect larval development of C. concholepas in this region. Further oceanographic and ecological investigation is necessary in order to answer the questions and hypotheses originated from this studyConcholepas concholepas (Mollusca, Gastropoda, Muricidae se distribuye entre las costas del sur de Perú y extremo sur de Chile. Prácticamente todos los estudios sobre este gastrópodo han sido realizados en costas expuestas, sin considerar los fiordos y canales del sur de Chile, a pesar de que estos representan

  9. La mecánica de fluidos y la teoría de la figura de la Tierra entre Newton y Clairaut (1687-1743)

    OpenAIRE

    Lafuente, Antonio

    1983-01-01

    El objeto de este artículo es analizar la literatura publicada sobre el tema de la figura de la Tierra entre 1687 y 1743. La primera fecha coincide con la publicación de los Philosophiae Naturalis Principia Mathematica. El estudio de Newton demostraba la insuficiencia de recursos de la ciencia experimental y el abismo existente entre la precisión que podían asegurar los métodos de la astronomía práctica y las nuevas exigencias planteadas por su mecánica celeste. La segunda fech...

  10. ENTRE LA COSTA DE COBIJA Y TIERRAS ALTAS: EL TRÁFICO ARRIERO A INICIOS DE LA REPÚBLICA BOLIVIANA

    OpenAIRE

    Letelier Cosmelli, Javiera

    2016-01-01

    Desde la configuración del Puerto de Cobija hasta la guerra del Pacífico, tanto indígenas como bolivianos y extranjeros establecieron relaciones en el marco de un contexto cambiante y complejo tanto a nivel nacional como internacional en donde se introduce la economía capitalista industrial. Es en ese marco que los arrieros y la movilidad entre costa y tierras altas se constituyeron en piezas claves para dar vida a Cobija y resto de Atacama. A partir de este escenario realizamos una revisión ...

  11. Impacto social del arrendamiento de tierras para generar energía eléctrica en La Venta, Juchitán de Zaragoza, Oaxaca.

    OpenAIRE

    Racilla Manuel, Sarita

    2013-01-01

    La investigación analiza lo que es el impacto social del arrendamiento de tierras y los cambios producidos por la instalación de parques eólicos, como caso de estudio del Ejido de La Venta, Juchitán de Zaragoza, Oaxaca. La tesis se realizó con una metodología mixta;(cuantitativa-cualitativa), para analizar el fenómeno antes descrito; está comprendida en cuatro capítulos. El primer capítulo plantea la estructura general de la investigación. El segundo, aborda el marco teórico y distintas visio...

  12. The profile of the imprisoned minors in detention centres for offenders and the professionals who treat them: a descriptive study in the Tierras de Oria institution

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    Tomás Sola Martínez

    2009-05-01

    Full Text Available Although juvenile delinquency is a present matter in media since many years ago, the profile that defines both imprisoned minors in detention centres and proffesionals who treat them is still unknown for most of our society. This article aims for these profiles to be shown by means of a descriptive study carried out in the “Tierras de Oria” institution about the age, gender and education of both their inmates and the proffesionals who intervene in their re-education and guarantee their social and labour rehabilitation when they join our society.

  13. Patrones de distribución de especies arbóreas de dosel y sotobosque a escala local en bosques de tierra firme, Amazonia colombiana

    OpenAIRE

    Juan Sebastian Barreto-Silva; Dairon Cárdenas López; Álvaro Javier Duque Montoya

    2014-01-01

    El efecto de la variación ambiental en la estructura de las comunidades arbóreas en bosques tropicales, aún se debate. En paisajes como los bosques de tierra firme, donde el gradiente ambiental disminuye, el efecto de los suelos sobre los patrones de distribución de especies es mínimo. En contraste, un mayor efecto de la variación edáfica y topográfica sobre la composición florística, se ha reportado en estudios con diferentes tipos de plantas en bosques tropicales. Este estudio se realizó en...

  14. Modelación de sistemas de puesta a tierra para evaluación de sobretensiones transitorias; Modelling large grounding systems to evaluate transient voltages

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    Yandi Anibal Gallego Landera

    2015-04-01

    Full Text Available En plantas generadoras y en subestaciones se requieren sistemas de puesta a tierra (SPT espaciosos, con configuraciones complejas como parte del sistema de protección contra rayos. Las corrientes provocadas por una descarga atmosférica pueden causar altas tensiones en los cables de señales ubicados cerca de los SPT. Estas tensiones transitorias pueden causar falsas señales, las cuales provocan un mal funcionamiento de la instrumentación electrónica. Determinar medidas de protección contra rayos requiere del conocimiento de la máxima elevación de la tensión entre el SPT y la tierra remota. El presente trabajo propone una metodología para analizar el comportamiento transitorio de redes de tierra. La técnica se basa en considerar los diferentes segmentos de la malla de tierra como elementos de líneas de transmisión. Para desarrollar esta metodología se utilizó el software MATLAB-Simulink. Los resultados se validan por comparación con modelos basados en la teoría del campo electromagnético publicados en la literatura. In generating plants and substations spacious grounding systems with complex configuration as part of the protection system against lighting, are required. The current caused by an atmospheric discharge can cause high voltages in the signal cables located near the grounding systems. These transient voltages may be the reason for the occurrence of false signals, which can cause malfunctioning and of electronic instruments. The knowledge of maximum elevation of voltage between the grounding systems and the remote ground is required to determine protection against lightning. This paper proposes a methodology to analyze the transient behavior of grounding grid. The technique is based on considering the different segments of the ground grid as elements of transmission lines. For modeling the grounding systems behavior in its transient state faster, the MATLAB-Simulink software was used. The results were validated by

  15. Determinación de la máxima capacidad de adsorción de la tierra de arriera en la eliminación de fosfatos en soluciones acuosas

    OpenAIRE

    Cremades Oliver, Lázaro Vicente

    2013-01-01

    Los materiales existentes en el trópico como es la tierra de arriera pueden ser usados como una herramienta de biorremediación en procesos de purificación y descontaminación de aguas residuales contaminadas. El objetivo de este estudio consistió en determinar la máxima capacidad de adsorción de tierra de arriera en la eliminación de fosfatos en periodos de tiempos determinados. La metodología aplicada consistió en la extracción de fósforo adsorbido por las arcillas y la técnica de Melhich, a ...

  16. Influencia del uso de la tierra con cultivos de cacao, chakras y bosque primario, sobre la diversidad, almacenamiento de carbono y productividad en la Reserva de la Biosfera Sumaco, Ecuador.

    OpenAIRE

    Jadán Maza, Ángel Oswaldo

    2013-01-01

    La investigación se realizó en la Reserva de la Biosfera Sumaco, en la provincia del Napo, Republica del Ecuador. Se estudiaron siete sistemas de uso de la tierra: Chakras con y sin sombra, cultivos de cacao propagados por semilla con y sin sombra, cacao injertado con y sin sombra y bosque primario. Se evaluaron tres variables de respuesta: diversidad arbórea y arbustiva, almacenamiento-acumulación de carbono (C) y productividad, en los diferentes sistemas de usos de la tierra.

  17. UN MÉTODO DE GESTIÓN AMBIENTAL PARA EL TRATAMIENTO Y LA DISPOSICIÓN FINAL ADECUADA DE UN RESIDUO PELIGROSO. CASO: TIERRA FULLER CONTAMINADA CON ACEITE DIELÉCTRICO

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    AGUDELO EDISON ALEXANDER

    2012-11-01

    Full Text Available La gestión ambiental de un residuo peligroso comprende diferentes etapas: generación, minimización, transporte, valorización, tratamiento y disposición. Este trabajo explora dos tecnologías para el tratamiento y disposición final de un residuo peligroso (RESPEL o tierra Fuller contaminada con aceite dieléctrico: una físico-química y otra biológica. Para la tecnología físico-química se usó hexano como solvente y se alcanzaron remociones del aceite dieléctrico del orden del 87% en la tierra Fuller contaminada, con una relación tierra Fuller: solvente de 1:8 p/v, una velocidad de agitación de 100 rpm y un tiempo de contacto de 30 min. La calidad del aceite dieléctrico recuperado no es apta para su uso nuevamente en equipos eléctricos, por su baja rigidez dieléctrica, baja densidad y color desfavorable. La tierra Fuller recuperada registró una densidad aparente de 0.641 gr/ml, una densidad real de 2.231 gr/ml y una porosidad de 72.075 %, lo que indica que dicha tierra esta muy cercana en sus características físicas a la tierra Fuller limpia.Para la tecnología biológica se trató la tierra contaminada en un biorreactor biológico de tierra activada, evaluando la velocidad de agitación y el tiempo de degradación necesario para alcanzar los niveles de descontaminación adecuados que permitan disponer el residuo en un relleno sanitario convencional o una escombrera sin riesgo alguno para la salud de los ecosistemas y el ser humano. Se alcanzaron remociones en este sistema del orden de 49.68%, aunque no se alcanzó los niveles de limpieza exigidos por la Resolución 1170 de 1997 del DAMA. El resultado es importante en cuanto se creía que altas concentraciones de hidrocarburos (superiores al 10% son inhibitorias de la actividad biológica. Se hizo el seguimiento cromatográfico a 10 especies de hidrocarburos presentes en el aceite dieléctrico que son importantes dentro de este producto.

  18. Dinámica reciente de la concentración de la propiedad y uso de la tierra en Colombia. Algunas reflexiones a propósito de la especialización productiva

    OpenAIRE

    Suescún, Carlos Alberto

    2011-01-01

    La dinámica histórica de desigualdad rural en Colombia, ha estado caracterizada principalmente por una persistente concentración de la propiedad de la tierra, que en tiempo reciente ha estado impulsada por factores como el despojo de tierras y la profundización de las desigualdades en el sector rural en un contexto de violencia y narcotráfico. A estos factores estructurales, en las últimas dos décadas se han sumado dos adicionales que han profundizado las desigualdades: la especialización pro...

  19. Caracterización actual de la utilización del uso del suelo y la cobertura vegetal en la región de la Tierra Indígena Sangradouto/Volta Grande-Mato Grosso, Brasil

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    Fernando Shinji Kawakubo

    2012-02-01

    Full Text Available El objeto de este trabajo fue el mapear el uso y cobertura vegetal en la tierra indígena Sangradouro/Volta Grande-MT (Brasil. Para ello se emplearon técnicas de Modelo Lineal de Mezcla Espectral acompañadas por la segmentación de las imágenes sintéticas y clasificación supervisada de los componentes divididos. El cálculo de las áreas correspondientes a las clases de uso del suelo y cobertura vegetal, permitió estimar el estado actual de la tierra en el contexto ambiental.

  20. Function and expression of the epithelial Ca(2+) channel family: comparison of mammalian ECaC1 and 2.

    NARCIS (Netherlands)

    Hoenderop, J.G.J.; Vennekens, R.; Müller, D.G.; Prenen, J.; Droogmans, G.; Bindels, R.J.M.; Nilius, B.

    2001-01-01

    1. The epithelial Ca(2+) channel (ECaC) family represents a unique group of Ca(2+)-selective channels that share limited homology to the ligand-gated capsaicin receptors, the osmolarity-sensitive channel OTRPC4, as well as the transient receptor potential family. Southern blot analysis demonstrated

  1. Reciente invasión del Archipiélago de Tierra del Fuego por la avispa Vespula germanica (Hymenoptera: Vespidae

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    Francisco J. SOLA

    2015-01-01

    Full Text Available Vespula germanica es una especie invasora de nivel mundial que ha sido detectada en la Patagonia continental de la Argentina y Chile. En este trabajo, ampliamos el rango de distribución de este véspido de la Patagonia, al Archipiélago de Tierra del Fuego. Indicamos ubicación, año y ambiente de cada avistamiento y/o captura. El patrón de expansión indicaría que esta especie está bien establecida tanto en áreas naturales como antrópicas, y probablemente ha dependido del transporte humano para llegar desde el continente. Esta comunicación breve sirve también para tomar medidas prácticas de mitigación y control de esta especie, incluyendo información básica para que la ciudadanía tome conciencia sobre su presencia y esto ayude a evitar su transporte a nuevos lugares. Finalmente, se recomienda mayor investigación para el manejo y control de esta especie invasora en Tierra del Fuego.

  2. Tierra y revolución. La campaña salteña en las primeras décadas del siglo XIX

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    Sara Emilia Mata

    2016-09-01

    Full Text Available La formación de la Junta de Gobierno en Buenos Aires en 1810 dio inicio a un proceso político que adquirió derroteros diversos en el interior del extenso territorio perteneciente al Virreinato del Río de la Plata. Al igual que en las provincias del Alto Perú,  la jurisdicción de Salta fue escenario  de una guerra de recursos de la cual participó la población rural integrando las milicias provinciales o “Escuadrones Gauchos”.  Interesa entonces observar en qué medida el conflicto bélico agudizó y puso en evidencia las tensiones existentes por los derechos de propiedad y usufructo de la tierra ya manifestadas a fines del siglo XVIII, particularmente en el valle de Lerma, y su incidencia en las disputas en torno a la tierra que tuvieron lugar luego de concluida la guerra en la provincia de Salta.

  3. La devolución de las tierras usurpadas al Concejo de Salamanca en los inicios de la Edad Moderna. Aproximación a su estudio

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    Clara Isabel LÓPEZ BENITO

    2009-12-01

    Full Text Available La importancia de las usurpaciones de tierras sufridas por el Concejo de Salamanca en sus términos y jurisdicción a lo largo del siglo XV quedó claramente demostrada con la publicación de N. Cabrillana, quien a partir de una rica documentación procedente del Archivo de la Biblioteca Nacional de Madrid, sacó a la luz un problema prácticamente desconocido hasta ese momento. Otras publicaciones posteriores, basadas en noticias aportadas por el Archivo Municipal de Salamanca, han complementado aquella aportación decisiva, aunque sin poder disponer nunca de un documento del alcance de la Pesquisa utilizada por Cabrillana; ni siquiera de un cuerpo de documentos homogéneo que permita medir y valorar de forma global la incidencia del fenómeno usurpador. Sin embargo, nadie duda de la trascendencia que éste tiene para la historia socioeconómica, e incluso paisajística, de la provincia de Salamanca. Este interés nos mueve a presentar ciertos datos y documentos recogidos en el siempre sorprendente Archivo de nuestro municipio, para intentar llegar un poco más allá en el conocimiento de las enajenaciones de tierras concejiles.

  4. Modelado, Simulación y Control de Satélites en los Puntos de Lagrange del Sistema Tierra - Luna

    Directory of Open Access Journals (Sweden)

    F. Alonso Zotes

    2011-07-01

    Full Text Available Resumen: El objetivo de este artículo es modelar, analizar y controlar una constelación de cinco satélites, situados en los puntos de Lagrange del sistema Tierra – Luna. El modelo se ha desarrollado incluyendo efectos complejos no considerados habitualmente, como el viento solar, la no esfericidad de los planetas y la deriva de la órbita lunar, para hacerlo más realista. Sobre los satélites se ejerce una propulsión continua, calculada por medio de controladores tipo PD, tanto convencionales como borrosos, y cuya finalidad es situar y mantener a cada satélite en su punto de Lagrange frente a las inestabilidades y derivas inherentes al sistema. El sistema completo se ha implementado en el lenguaje de modelado Modelica, para el que se han creado una serie de elementos aeroespaciales, y las simulaciones se han desarrollado con el software Dymola. Tanto con los controladores clásicos como con los borrosos se han obtenido muy buenos resultados. Palabras clave: modelado, simulación, control borroso, satélites, puntos de Lagrange, sistema Tierra-Luna

  5. 3D modelling of the Salesian mission Nuestra Señora de la Candelaria cemetery (Río Grande, Tierra del Fuego, Argentina

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    Melisa A. Salerno

    2017-07-01

    Full Text Available The Salesian mission Nuestra Señora de La Candelaria operated between the late 19th and the mid-20th centuries in Río Grande (Tierra del Fuego, Argentina. Its cemetery still holds the remains of indigenous and religious people who lived in the institution, and settlers who lived nearby. For some years, the place has received the attention of a research project interested in discussing the dynamics of colonial relationships in Tierra del Fuego. The cemetery has a long history of changes, and even though it was declared part of the national and provincial heritage, its preservation conditions are relatively poor. In this article we present the work carried out to produce a 3D model of the cemetery, combining information obtained by planialtimetric and photographic survey. The result represents a detailed and photorealistic record of the materiality of the cemetery at present. Therefore, it does not only provide a relevant tool to colaborate in the promotion and protection of the archaeological heritage. It also provides a platform for future 3D modelling of historical images of the cemetery, with different research goals.

  6. USOS DE LA TIERRA, CONFLICTO Y PODER POLÍTICO EN LA FRONTERA AGRÍCOLA DEL ALTO SINÚ 1940-1970

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    Ruth Esther Gutierrez

    2016-08-01

    Full Text Available El presente artículo presenta un recorrido histórico, a partir del cual aborda las perspectivas historiográficas desde donde se ha estudiado la manera cómo la subregión del alto Sinú se convirtió en una frontera agrícola, que a mediados del siglo XX y más específicamente entre 1940 y 1970, despertó un profundo interés en las élites económicas y políticas nacionales y regionales, quienes abiertamente iniciaron un proceso de acaparamiento de las tierras e instauración de sistemas laborales que incluían la sujeción de la mano de obra a las corrientes bipartidistas liberales y conservadoras. Así mismo, se presentan las formas contestatarias que adoptaron los campesinos del alto Sinú frente al monopolio de la tierra ostentado por gamonales y funcionarios públicos.

  7. Información molecular obtenida a partir de pieles de la colección del Museo Regional Fagnano, Río Grande, Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Petrigh, Romi

    2014-10-01

    Full Text Available En el presente trabajo se aplicaron técnicas moleculares sobre muestras poco conservadas de pieles depositadas en la colección del Museo Regional Monseñor Fagnano, Tierra del Fuego, Argentina, con el objetivo de identificar la especie con la que fueron confeccionadas. Se extrajeron pelos de mantas realizadas con pieles de guanaco (Lama guanicoe por Selk’nam y de una piel de puma (Puma concolor procedente de la provincia de Santa Cruz. Ambas muestras se encontraban almacenadas en el Museo Regional Monseñor Fagnano y en la Misión Salesiana Candelaria en Rio Grande, Tierra del Fuego, Argentina. La extracción de ADN de los fragmentos de pelos de 5mm de longitud se realizó en un buffer de lisis PCR-compatible. Se amplificaron por PCR fragmentos específicos de ADN mitocondrial y se secuenciaron. Las secuencias fueron comparadas con las depositadas en la base de secuencias de nucleótidos del National Center for Biotechnology Information (NCBI de Estados Unidos. La aplicación de técnicas moleculares permitió recuperar secuencias de ADN de muestras de pieles con un estado de conservación poco óptimo para análisis genéticos, pudiendo extenderse a otras fuentes de pelos como las fibras textiles de origen arqueológico de la región.

  8. EFICACIA EN LA RESTITUCIÓN DE TIERRAS A VÍCTIMAS DE DESPLAZAMIENTO FORZADO DE OCAÑA NORTE DE SANTANDER

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    Fidencio Suarez Vargas

    2016-02-01

    Full Text Available RESUMEN En este trabajo investigativo desarrollamos el tema referente a la eficacia en la restitución de tierras a las víctimas de desplazamiento forzado de la ciudad de Ocaña, Norte de Santander, durante el año 2014. A través del mismo nos propusimos compendia y analizar los distintos componentes jurídicos referentes al tema de estudio, con el objeto de establecer su funcionalidad en el municipio de Ocaña. Por medio del análisis cuantitativo de las cifras que reportan los juzgados de restitución de tierras respecto al número de reclamaciones realizadas a partir de la expedición de la ley, número de sentencias y número de restituciones llevadas a cabo, establecimos el nivel de eficacia del estado en lo que respecta al cumplimiento de este derecho principalísimo a las víctimas del conflicto armado colombiano. Finalmente, conoceremos que el grado de cumplimiento por parte del estado a las víctimas de desplazamiento del municipio de Ocaña es inexistente.

  9. Ejércitos irregulares y organización campesina: Guáimaro, el camino hacia la restitución del derecho a la tierra

    Directory of Open Access Journals (Sweden)

    Patricia Stella Jaramillo Guerra

    2010-07-01

    Full Text Available Este artículo recoge los resultados preliminares del proyecto de Extensión “Estructura Agraria, soberanía alimentaria y mujer rural”, donde se relaciona el impacto del paramilitarismo en un corregimiento ribereño del departamento del Magdalena. En el decurso del proceso investigativo se encontró que, luego de un dramático capítulo de violencia y desplazamiento paramilitar, mediante el cual se evidenció empíricamente la concreción de estos grupos irregulares como empresas armadas, generaron procesos de apropiación forzosa de la tierra, robusteciendo aún más el esquema de concentración que históricamente se ha consolidado. Justamente en este contexto se ha presentado un interesante proceso de movilización campesina que busca desarticular el curso de su descomposición descendente, al colocar la tierra, en primer lugar, como fin esencial en sus dimensiones productivas pero identitarias, por sobre todo.

  10. Aproximación a la patología presentada en las construcciones de tierra. Algunas recomendaciones de intervención

    Directory of Open Access Journals (Sweden)

    Rodríguez, M. A.

    2011-09-01

    Full Text Available This article shows several points to consider in the study and conservation of the heritage of earth. We show the most characteristic damages of these buildings and we propose some recommendations for the correct diagnostic of their pathology. Finally, some recommendations for the conservation of this heritage are given.

    En el presente artículo se ponen de manifiesto una serie de aspectos que es necesario tener presente a la hora de acometer un estudio sobre la patología presentada en las construcciones de tierra en general, y patrimoniales en particular. Para ello, y tras proponer una serie de recomendaciones que contribuyan a un correcto diagnóstico de la patología presentada, se identifican las lesiones más características de este tipo de construcciones. Por último, se proponen algunas pautas de intervención en función de la patología presentada, así como recomendaciones de carácter general para la conservación del patrimonio de estructuras de tierra.

  11. Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales from Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Ana C Scorsetti

    2012-06-01

    Full Text Available Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T. cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T. cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4ºC, 12ºC and 24ºC, on different agar media supplemented with the following specific substrates: chitin azure, Tween ® 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4ºC, 12ºC and 24ºC. The suspension was adjusted to a concentration of 1x10 7 conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24°C, the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween® 20 at the lower two incubation temperatures of 4

  12. Tierras indígenas, demarcaciones territoriales y gubernamentalización: El caso Huarpe, Pcia de Mendoza

    Directory of Open Access Journals (Sweden)

    Leticia Katzer

    2010-07-01

    Full Text Available El objetivo de este trabajo es analizar, a través del acercamiento a una etnografía de los procesos administrativos, la trama de dispositivos estatales que han operado en la asignación de tierras a los indígenas adscriptos como Huarpes y que operan contemporáneamente en la definición de sus derechos territoriales. Se trata de explicitar las representaciones, intereses y saberes que han guiado las propuestas de intervención, recuperándolos como componentes constitutivos de un proceso social e histórico. A diferencia de las narrativas administrativas -que mediante la adopción de un lenguaje tecnicista y de nociones como la de hábitat, terminan por naturalizar, neutralizar y deshistorizar los conflictos políticos implícitos en la construcción de territorios étnicos- enfocamos los mecanismos de intervención sobre los indígenas como una forma de territorialización, revisando críticamente la pretendida mirada neutra y objetiva del aparato administrativo-judicial, apoyada en representaciones atemporales.The objective of this work is to analyze, through approach to one ethnography of the administrative processes, the plot of state devices that have operated in the allocation of earth to the adscript indigenous like Huarpes and that operate contemporarily in the definition of their territorial rights. It is tried to specify the representations, interests and learnings that they have guided the intervention proposals, recovering them like constituent components of a social and historical process. Unlike the administrative narratives - that by means of the adoption of a technicist language and slight knowledge like the one of habitat, they finish naturalizing, neutralizing and unhistoring the conflicts implicit politicians in the construction of ethnic territories we focused the intervention mechanisms on the natives like one territorialization form, reviewing critically the tried neutral and objective glance of the administrative

  13. LA DEGRADACIÓN DE TIERRAS COMO EJE EN LA ORGANIZACIÓN DE LOS CONTENIDOS EN GEOGRAFÍA

    Directory of Open Access Journals (Sweden)

    María Elena Chiementon

    2008-12-01

    Full Text Available El deterioro ambiental no es un fenómeno reciente, pero la magnitud de los cambios que se observan actualmente no tiene precedentes. En este sentido, la degradación de tierras es una de las problemáticas que alcanza niveles alarmantes a escala mundial, poniéndose de manifiesto a través de una disminución significativa de la capacidad productiva del territorio. Esta problemática también está presente en la región patagónica y en particular en la Provincia de Neuquén afectando especialmente a los productores de menores recursos. Los procesos degradatorios son producto de las transformaciones que se introducen en el sistema natural, asociadas sobre todo a la aceleración de la erosión hídrica y eólica, que modifican el equilibrio y la dinámica de las relaciones entre todos sus componentes. Si bien se trata de un problema que se expresa fundamentalmente en la alteración de procesos naturales, su raíz es política, social y económica. En este marco la riqueza que ofrece este tema como eje de trabajo, propicia numerosas posibilidades en el vínculo entre el proceso de enseñanza aprendizaje con la actualidad. De esta manera se presenta como una forma diferente de trabajo áulico en la construcción de conceptos, procedimientos y valores, favoreciendo el tratamiento y la reflexión de temas tradicionales como la erosión, los circuitos productivos, etc. y aprovechando el uso cada vez más masivo de las imágenes satelitales que permiten mostrar la dimensión del problema. El presente trabajo intenta generar aportes para su abordaje conceptual y metodológico en la enseñanza de la Geografía, reconociendo la gravedad de la situación, por sus alcances a mediano y largo plazo en las distintas escalas. Analizarlo desde una perspectiva geográfica permite comprenderlo y explicarlo a partir de la articulación Sociedad-Naturaleza, organizando un amplio abanico de temas y pudiendo ser utilizado como hilo conductor en la organización de

  14. Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales) from Tierra del Fuego, Argentina.

    Science.gov (United States)

    Scorsetti, Ana C; Elíades, Lorena A; Stenglein, Sebastián A; Cabello, Marta N; Pelizza, Sebastián A; Saparrat, Mario C N

    2012-06-01

    Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4 degreeC, 12 degreeC and 24 degreeC), on different agar media supplemented with the following specific substrates: chitin azure, Tween 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4 degree C, 12 degree C and 24 degree C). The suspension was adjusted to a concentration of 1x10(7) conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24 degreeC), the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween 20 at the lower two incubation

  15. USACE Navigation Channels 2012

    Data.gov (United States)

    California Natural Resource Agency — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...

  16. Calcium channel blocker overdose

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used ...

  17. Quantum Channels With Memory

    International Nuclear Information System (INIS)

    Rybar, T.

    2012-01-01

    Quantum memory channels represent a very general, yet simple and comprehensible model for causal processes. As such they have attracted considerable research interest, mostly aimed on their transfer capabilities and structure properties. Most notably it was shown that memory channels can be implemented via physically naturally motivated collision models. We also define the concept of repeatable channels and show that only unital channels can be implemented repeat ably with pure memory channels. In the special case of qubit channels we also show that every unital qubit channel has a repeatable implementation. We also briefly explore the possibilities of stroboscopical simulation of channels and show that all random unitary channels can be stroboscopically simulated. Particularly in qubit case, all indivisible qubit channels are also random unitary, hence for qubit all indivisible channels can be stroboscopically simulated. Memory channels also naturally capture the framework of correlated experiments. We develop methods to gather and interpret data obtained in such setting and in detail examine the two qubit case. We also show that for control unitary interactions the measured data will never contradict a simple unitary evolution. Thus no memory effects can be spotted then. (author)

  18. Eight channel fast scalar

    Energy Technology Data Exchange (ETDEWEB)

    Waddoup, W D; Stubbs, R J [Durham Univ. (UK)

    1977-11-01

    An eight channel 64-bit scaler has been constructed with a static CMOS memory. Scaling frequencies are independently variable, at each channel, as are the number of bits/channel. The scaler, when used in conjunction with a multichannel charge to time converter results in a very flexible, gated multichannel ADC.

  19. KV7 potassium channels

    DEFF Research Database (Denmark)

    Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A

    2014-01-01

    Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...

  20. Fertilizing Southern Hardwoods

    Science.gov (United States)

    W. M. Broadfoot; A. F. Ike

    1967-01-01

    If present trends continue, fertilizing may soon be economically feasible in southern hardwood stands. Demands for the wood are rising, and the acreage alloted for growing it is steadily shrinking. To supply anticipated requests for information, the U. S. Forest Service has established tree nutrition studies at the Southern Hardwoods Laboratory in Stoneville,...

  1. Southern Gothic Literature

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2017-01-01

    Provides an outline of Southern Gothic Literature, offers an argument about its history and shape, and discusses the scholarly literature surrounding Southern Gothic. Oxford Research Encyclopedia is an online peer-reviewed encyclopedia for researchers, teachers, and students interested in all...... facets of the study of literature...

  2. Construcción sustentable, análisis de retraso térmico a bloques de tierra comprimidos / Sustainable building, thermal analysis of delay to earth blocks tablets

    Directory of Open Access Journals (Sweden)

    Roux Gutiérrez, Rubén Salvador

    2015-09-01

    Full Text Available Este artículo es el resultado de la investigación que aborda el tema las propiedades térmicas de los Bloques de Tierra Comprimida (BTC, para corroborar las ventajas de este material de construcción alternativo, sobre los materiales convencionales, para comprobar que estos materiales pueden satisfacer las necesidades de la población en la construcción de sus viviendas digna, mejorando la calidad de vida del usuario y produciendo un menor impacto ambiental. Se plantea el uso de BTC como unidad de análisis, elaborado con material de la zona del sur de Tamaulipas, probando sus ventajas como regulador natural de temperatura contra el bloque de concreto y el ladrillo recocido de la región, que son empleados en el ámbito de la construcción de viviendas. Las pruebas térmicas realizadas fueron simulando el efecto del sol sobre un muro, registrándose la temperatura durante las pruebas determinándose el retraso térmico en los muros dependiendo del material. Es así como con el resultado de las pruebas se determinó cual es el material óptimo para emplear como envolvente de la vivienda. This article is the result of research that addresses the issue the thermal properties of the Compressed Earth Blocks (CEB, to corroborate the benefits of this alternative building material, on the conventional materials, to verify that these materials can meet the needs of the population in the construction of their homes worthy, improving the quality of life of the user and producing a lower environmental impact. Considering the use of CEB as a unit of analysis, developed with materials from the area of southern Tamaulipas, proving its advantages as natural regulator of temperature against the concrete block and brick annealing of the region, who are employed in the field of housing construction. Thermal testing carried out were simulating the effect of the sun on a wall, the temperature recorded during the tests determined the delay in the thermal walls

  3. Uranium in tertiary stream channels, Lake Frome area, South Australia

    International Nuclear Information System (INIS)

    Brunt, D.A.

    1978-01-01

    Uranium exploration over a wide area of the Southern Frome Embayment, South Australia, has defined a number of Lower Tertiary fluvial palacochannels incised in older rocks. The buried channels contain similar stratigraphic sequences of interbedded sand, silt, and clay, probably derived from the adjacent uranium-rich Olary Province. Uranium mineralization is pervasive within two major palacochannels, and four small uranium deposits have been found in the basal sands of these channel sequences, at the margins of extensive tongues of limonitic sand. A genetic model is proposed suggesting formation by a uraniferous geochemical cell which migrated down the stream gradient and concentrated uranium on its lateral margins adjacent to the channel bank

  4. Southern Identity in "Southern Living" Magazine

    Science.gov (United States)

    Lauder, Tracy

    2012-01-01

    A fantasy-theme analysis of the editors' letters in "Southern Living" magazine shows an editorial vision of valuing the past and showcasing unique regional qualities. In addition, a content analysis of the visual representation of race in the magazine's formative years and recent past validates that inhabitants of the region were portrayed…

  5. Fine Channel Networks

    Science.gov (United States)

    1997-01-01

    A color image of fine channel networks on Mars; north toward top. The scene shows heavily cratered highlands dissected by dendritic open channel networks that dissect steep slopes of impact crater walls. This image is a composite of Viking high-resolution images in black and white and low-resolution images in color. The image extends from latitude 9 degrees S. to 5 degrees S. and from longitude 312 degrees to 320 degrees; Mercator projection. The dendritic pattern of the fine channels and their location on steep slopes leads to the interpretation that these are runoff channels. The restriction of these types of channels to ancient highland rocks suggests that these channels are old and date from a time on Mars when conditions existed for precipitation to actively erode rocks. After the channels reach a low plain, they appear to end. Termination may have resulted from burial by younger deposits or perhaps the flows percolated into the surface materials and continued underground.

  6. Proyecto de reforestación de tierras agrarias con encina (Quercus ilex L ballota Samp) para la producción de trufa (Tuber melanosporum Vitt.), en el término municipal de Peralveche, Guadalajara

    OpenAIRE

    RUIPÉREZ MARTÍNEZ, DIEGO

    2010-01-01

    Ruipérez Martínez, D. (2010). Proyecto de reforestación de tierras agrarias con encina (Quercus ilex L ballota Samp) para la producción de trufa (Tuber melanosporum Vitt.), en el término municipal de Peralveche, Guadalajara. http://hdl.handle.net/10251/8975. Archivo delegado

  7. Sin Tierras No Hay Paraíso: Turismo, organizaciones agrarias y apropiación territorial en México. Gustavo Marín Guardado (Coordinador. El Sauzal, Tenerife.

    Directory of Open Access Journals (Sweden)

    Maximiliano E Korstanje

    2016-08-01

    Full Text Available Sin Tierras No Hay Paraíso se sitúa como un trabajo editado por el profesor Marín Guardado que convoca 10 excelentes capítulos donde queda en evidencia esa tensión primigenia entre tierras orientadas al trabajo, y esta suerte de centros ejemplares ideológicamente orquestados para reforzar la superioridad de una clase sobre el resto de la sociedad.  En dicho proceso, y lejos de generar un crecimiento sustentable, el turismo monopoliza el uso de ciertas tierras creando serios efectos indeseados en zonas enteramente dedicadas a la agricultura. La lucha de las organizaciones agrarias en México por permanecer en las tierras que históricamente les pertenecían es inversamente proporcional a la voracidad empresaria del capitalismo moderno. Una de las grandes falencias de los estudios turísticos consiste en la sobrevaloración del turismo como un organizador social y geográfico, ciertamente con fallas que deben ser corregidas pero trivializando los alcances de los estudios postmarxistas los cuales han denunciado como los procesos de re-territorialización esconden una lógica de la “expropiación” y/o transferencia de riqueza.

  8. Morphology of channels and channel-sand bodies in the Glauconitic sandstone member (Upper Mannville), Little Bow area, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, J.C.; Hermanson, S.W.; Lawton, D.C.

    1982-12-01

    Large channels in the Glauconitic sandstone member of southern Alberta have proved to be difficult exploration targets because of an irregular distribution of reservoir sands within the channels. In the Little Bow area, two channels are present in the lower part of the Glauconitic member and have cut into the underlying Calcareous member. The channels can be recognized where they truncate regional markers of the Calcareous member -- the Bantry shale and Ostracod limestone, and where channel-fill deposits exhibit uniform geophysical log characters, indicating sandstone- or mudstone-filled reaches. Sediments of the Glauconitic member adjacent to the channels comprise a series of splay sandstones and mudstones that prograded into interdistributary bays of the lower delta plain. The two channels associated with these deposits are interpreted as distributary channels. Sand bodies within the channels formed as lateral bars and are isolated by mudstones which mark the abandoned stream course. Geological exploration for these discontinuous channel sandstones is difficult, and high-resolutio seismic data integrated with sound geologic modelling are critical for successful prospect delineation.

  9. Ion channels in plants.

    Science.gov (United States)

    Hedrich, Rainer

    2012-10-01

    Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K(+)-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K(+) channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.

  10. Rare-Earth-Rich Alloys; Alliages a Teneur Elevee en Terres Rares; Splavy, obogashchennye redkozemel'nymi ehlementami; Aleaciones Ricas en Tierras Raras

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, M.; Kato, H. [Albany Metallurgy Research Center, Bureau of Mines, United States Department of the Interior, Albany, OR (United States)

    1964-06-15

    ainsi que leurs effets sur les points de fusion, les transformations de l'etat solide et la resistance a la corrosion. Ils ont etabli des diagrammes de phases jusqu'au premier compose ou entectique a teneur elevee en terres rares, selon que l'un ou l'autre apparaissait le premier. Une fois cette partie des travaux termines, ils ont fabrique des alliages qu'ils ont traites a chaud pour obtenir le maximum de solubilite a l'etat solide du metal d'alliage qui n'est pas une terre rare,, et ils ont fait des essais d'oxydation et de corrosion. Ils n'ont observe aucune amelioration de la resistance des terres rares a l 'oxydation dans l 'atmosphere a la suite de l 'operation; en fait, la plupart des metaux d'addition se sont reveles nuisibles. L'aluminium augmentait fortement la resistance a la corrosion par l'eau chaude des terres rares ayant fait l'objet des essais; d'autres metaux n'augmentaient cette resistance des terres rares qu'a un moindre degre. (author) [Spanish] Los metales de las tierras raras presentan interes en el control de reactores de potencia debido a su elevada seccion eficaz de captura de neutrones termicos, pero por desgracia se corroen con facilidad. Partiendo del supuesto de que ciertos metales no pertenecientes al grupo de las tierras raras pueden alearse con disprosio, erbio, gadolinio y samario mejorando sus propiedades, los autores estudiaron los efectos que esta aleacion ejerce sobre las tierras raras. Estudiaron la solubilidad de metales como el circonio, vanadio, cromo, hierro, niquel, cobre, aluminio y silicio en disprosio, erbio, gadolinio y samario, y determinaron sus efectos sobre los respectivos puntos de fusion, las transformaciones de estado solido y la resistencia a la corrosion. Prepararon diagramas de fase hasta el primer compuesto rico en tierra rara o hasta el eutectico, segun cual apareciera primero. A l terminar esta parte del trabajo, prepararon aleaciones, que sometieron a un tratamiento termico para obtener un maximo de

  11. Especiación de tierras raras en las soluciones ácidas y neutras del sistema de drenaje del Arroyo del Val (Zaragoza

    Directory of Open Access Journals (Sweden)

    Zamora, A.

    1994-08-01

    -90 % of LREE and for 100 % of HREE. LnPO04 and Ln(PO43-2 complexes are quite significant compared to carbonate complexes, mainly in the speciation of HREE. These results il1ustrate the importance of phosphate ion concentration and REE phosphate complexation reactions in REEs speciation calculations.Las soluciones de la cuenca de drenaje del Arroyo del Val (Zaragoza presentan unas características geoquímicas muy diferenciadas, lo que las hace especialmente apropiadas para el estudio de diferentes aspectos acerca del comportamiento de los elementos de las Tierras Raras. Esta cuenca está constituida por un curso principal (Arroyo del Val de aguas ácidas (con valores de pH entre 3 y 4.5 e importantes concentraciones de sulfato, Al, Fe y distintos metales pesados al que desaguan varios afluentes de aguas bicarbonatadas (sulfatadas cálcicas (con valores de pH de hasta 7.5, alcalinidad apreciable y notables concentraciones de fosfato. En los puntos de confluencia del Arroyo del Val con los afluentes se producen espectaculares procesos de floculación de coloides ricos en aluminio, hierro y sulfato que tapizan el fondo del curso principal. Los elementos de las Tierras Raras fueron analizados en distintas muestras de aguas ácidas tomadas a lo largo de la cabecera del Arroyo del Val y en dos muestras de aguas neutras correspondientes a dos de los afluentes del sistema. Las concentraciones de estos elementos determinadas en las soluciones ácidas son, cuando menos, dos órdenes de magnitud superiores a las de las soluciones neutras y sus pautas de distribución (normalizadas frente a NASC muestran un marcado enriquecimiento en las Tierras Raras Intermedias (IREE; Eu-Tb. Los cálculos de especiación de REE realizados en las aguas ácidas muestran que estos elementos se encuentran de forma dominante como especies iónicas libres (Ln3+ ≈ 35 % y especialmente formando complejos con sulfato (LnSO+4 ≈ 60% y en menor proporción como Ln(SO4-2 ≈ 5%. Estos porcentajes

  12. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Shlomo Shamai (Shitz

    2009-01-01

    Full Text Available This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom (s.d.o.f. are derived for the degraded case with one receiver. Schemes to achieve the s.d.o.f. for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable s.d.o.f. is given for the general case.

  13. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Kramer Gerhard

    2009-01-01

    Full Text Available Abstract This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom ( are derived for the degraded case with one receiver. Schemes to achieve the for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable is given for the general case.

  14. ATP Release Channels

    Directory of Open Access Journals (Sweden)

    Akiyuki Taruno

    2018-03-01

    Full Text Available Adenosine triphosphate (ATP has been well established as an important extracellular ligand of autocrine signaling, intercellular communication, and neurotransmission with numerous physiological and pathophysiological roles. In addition to the classical exocytosis, non-vesicular mechanisms of cellular ATP release have been demonstrated in many cell types. Although large and negatively charged ATP molecules cannot diffuse across the lipid bilayer of the plasma membrane, conductive ATP release from the cytosol into the extracellular space is possible through ATP-permeable channels. Such channels must possess two minimum qualifications for ATP permeation: anion permeability and a large ion-conducting pore. Currently, five groups of channels are acknowledged as ATP-release channels: connexin hemichannels, pannexin 1, calcium homeostasis modulator 1 (CALHM1, volume-regulated anion channels (VRACs, also known as volume-sensitive outwardly rectifying (VSOR anion channels, and maxi-anion channels (MACs. Recently, major breakthroughs have been made in the field by molecular identification of CALHM1 as the action potential-dependent ATP-release channel in taste bud cells, LRRC8s as components of VRACs, and SLCO2A1 as a core subunit of MACs. Here, the function and physiological roles of these five groups of ATP-release channels are summarized, along with a discussion on the future implications of understanding these channels.

  15. ESTRUCTURA POBLACIONAL DE LA PALMA IRIARTEA DELTOIDEA, EN UN BOSQUE DE TIERRA FIRME DE LA AMAZONIA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    Gonzalez Roy

    2012-06-01

    Full Text Available El objetivo de esta investigación fue caracterizar la densidad y la estructura poblacional de la palma bombona Iriartea deltoidea en un bosque de tierra firme de la zona sur del Parque Nacional Natural Amacayacu, en la Amazonia Colombiana. En seis parcelas de 1 ha y 90 transectos de 50 x 1 m, se censaron todos los individuos de la especie. Para cada individuo, se registró la altura del tallo, el estado morfológico de las hojas (i.e. hojas enteras, hojas divididas, forma de las pinnas, la formación de raíz fúlcrea, la altura del cono de la raíz y el estado fenol��gico (brácteas, inflorescencias e infrutescencias. Se encontraron 2819 individuos (376±58 ind/ha que se agruparon en tres grandes categorías de edad significativamente diferentes (e.g. plántulas, juveniles y adultos. La gran categoría Plántulas se caracterizó por individuos con hojas no divididas, sin formación de raíces fúlcreas y comprendió el 96.6% de los individuos muestreados. Esta se subdividió en seis categorías de plántulas estadísticamente significativas dadas por cambios en la altura, número y morfología de las hojas. La gran categoría Juvenil consistió en individuos con hojas divididas en pinnas, formación de raíces fúlcreas con altura de cono radicular menor a 1 m, sin estructuras reproductivas y con 1.5% (42 de los individuos totales. Esta se subdividió en dos categorías de juveniles (I y II. La categoría Adultos incluyó todos los individuos con hojas divididas en pinnas, formación de raíces fúlcreas con altura del cono radicular mayor a 1 m y con presencia de estructuras reproductivas. Estos correspondieron al 1.9% (54 de los individuos y se subdividieron en dos categorías: Adultos I y Adultos II, dadas principalmente por diferencias significativas en la altura. La densidad de la población presentó una distribución típica de poblaciones naturales de plantas tropicales, siguiendo un modelo de Poisson en donde abundan individuos de

  16. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  17. European Southern Observatory

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    Professor A. Blaauw, Director general of the European Southern Observatory, with George Hampton on his right, signs the Agreement covering collaboration with CERN in the construction of the large telescope to be installed at the ESO Observatory in Chile.

  18. University of Southern California

    Data.gov (United States)

    Federal Laboratory Consortium — The focus of the University of Southern California (USC) Children''s Environmental Health Center is to develop a better understanding of how host susceptibility and...

  19. Southern African Business Review

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited scientific journal of the College of Economic and Management Sciences of the .... The effects of extended water supply disruptions on the operations of SMEs · EMAIL FREE ...

  20. Southern African Business Review

    African Journals Online (AJOL)

    Southern African Business Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2016) >. Log in or Register to get access to full text downloads.

  1. HIPPI and Fibre Channel

    International Nuclear Information System (INIS)

    Tolmie, D.E.

    1992-01-01

    The High-Performance Parallel Interface (HIPPI) and Fibre Channel are near-gigabit per second data communications interfaces being developed in ANSI standards Task Group X3T9.3. HIPPI is the current interface of choice in the high-end and supercomputer arena, and Fibre Channel is a follow-on effort. HIPPI came from a local area network background, and Fibre Channel came from a mainframe to peripheral interface background

  2. Nuclear reactor coolant channels

    International Nuclear Information System (INIS)

    Macbeth, R.V.

    1978-01-01

    Reference is made to coolant channels for pressurised water and boiling water reactors and the arrangement described aims to improve heat transfer between the fuel rods and the coolant. Baffle means extending axially within the channel are provided and disposed relative to the fuel rods so as to restrict flow oscillations occurring within the coolant from being propagated transversely to the axis of the channel. (UK)

  3. CONFLICTOS DE INTERESES EN LA ORDENACIÓN DE UN TERRITORIO DE MONTAÑA: EL TURISMO RURAL EN LA TIERRA PINARIEGA SORIANA

    Directory of Open Access Journals (Sweden)

    Jesús María Bachiller Martínez

    2012-01-01

    Full Text Available El auge del uso público en los espacios rurales es un componente más de las crecientes relaciones campo-ciudad. Los conflictos se multiplican, no solo en la relación entre desarrollo turístico y conservación, sino también en el trato con los propietarios rústicos, públicos y privados, que tienden a organizarse y plantear sus reivindicaciones en la ordenación y gestión de los territorios implicados. Se expone, como ejemplo, un propietario de excepción, la Mancomunidad de los 150 pueblos de la Tierra de Soria/ayuntamiento de Soria, que ha tenido que hacer frente al cambio de función que ha supuesto el aumento del uso público en sus montes.

  4. Propiedades magnéticas y micromorfología de suelos en el sitio arqueológico Marazzi 2, Isla Grande de Tierra del Fuego, Chile

    OpenAIRE

    Ozán, Ivana Laura; Orgeira, Maria Julia

    2017-01-01

    El objetivo del presente trabajo es investigar el origen de la señal magnética (natural y/o antrópica) y su vinculación con la micromorfología de suelos, en dos perfiles del sitio arqueológico Marazzi 2, perteneciente al Holoceno tardío y ubicado en el noroeste de la Isla Grande de Tierra del Fuego (Chile). Los resultados muestran que el perfil P1 presenta un pico de la señal magnética (presencia de magnetita y/o titanomagnetita) entre los 30 - 70 cm, que coincide con un horizonte Ab y ABb en...

  5. Study of the thermal behaviour of traditional wine cellars: the case of the area of ''Tierras Sorianas del Cid'' (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, I.C.; Ocana, S.M. [Universidad Politecnica de Madrid (Spain). Dpto. de Construccion y Vias Rurales

    2005-01-01

    This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them are analyzed and our hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 20{sup o}C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the ''Tierras Sorianas'' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint. (author)

  6. Localización de hipocentros y determinación de su magnitud en Tierra del Fuego y zonas aledañas

    Directory of Open Access Journals (Sweden)

    Carolina Buffoni

    2009-12-01

    Full Text Available Nuevos hipocentros de sismos de baja a mediana magnitud han sido calculados con el fin de estudiar la sismicidad en la Isla de Tierra del Fuego y zonas aledañas. La región presenta un complejo escenario tectónico: la isla es atravesada por una falla transformante conocida como Falla de Magallanes-Fagnano la cual divide a Tierra del Fuego en dos bloques continentales. Esta falla constituye el mayor segmento continental del borde de las placas de Scotia y Sudamericana. La isla tiene una importante historia sismológica que incluye un evento de carácter destructivo ocurrido en diciembre de 1949 el cual alcanzó una magnitud de 7.8 en la escala de Richter. De un análisis de sismicidad histórica, se conocen reportes de sismos en los años 1929, 1930, 1944, 1949 y 1970. En el presente trabajo se ha realizado la localización de los hipocentros y el análisis de los errores en la determinación. A tal efecto se analizaron los registros de 5 estaciones sismológicas para el período enero 2007 - diciembre 2007. Más de 180 sismos fueron localizados y algunos de ellos comparados con los cinco eventos registrados por el NEIC (National Earthquake Information Center y el ISC (Internacional Seismological Centre para el mismo período. El cálculo de magnitud fue realizado a partir de la amplitud del primer arribo. La mayoría de los sismos tienen un valor de magnitud mb que se concentra entre 2 y 4 grados. Con respecto a la profundidad hipocentral, más del 50% de los eventos localizados tienen profundidades en los primeros 10 km. El mapa de sismicidad obtenido muestra una distribución de sismos sobre y en las cercanías de la falla Magallanes-Fagnano, una concentración de epicentros en el área de la Cordillera de Darwin y en los alrededores de la placa de Scotia, manifestando indicios de una correlación con el ambiente geotectónico del área de estudio.New hypocentre locations of earthquakes with low to medium magnitude have been calculated in

  7. En una tierra inmensa y sin clérigos. La fundación del seminario del Tucumán, 1587-1611

    Directory of Open Access Journals (Sweden)

    Leticia Pérez Puente

    2016-01-01

    Full Text Available En este trabajo se estudia la creación del seminario conciliar de la diócesis del Tucumán. Un colegio muy distinto a los ordenados en el concilio de Trento, tanto por sus características, como porque su fundación formal tuvo por objetivo que la Compañía de Jesús se arraigara en el territorio tucumano y se hiciera cargo de la evangelización. Se trata de un ejemplo de cómo los mandatos del Concilio de Trento debieron modificarse al implantarse en Indias, pues, al igual que cualquier otra norma, los decretos canónicos tuvieron que adaptarse para responder a las necesidades de cada una de las diócesis, a las características de la tierra y a la forma en que en ella se organizaban los poderes.

  8. New Channels, New Possibilities

    DEFF Research Database (Denmark)

    Pieterson, Willem; Ebbers, Wolfgang; Østergaard Madsen, Christian

    2017-01-01

    In this contribution we discuss the characteristics of what we call the fourth generation of public sector service channels: social robots. Based on a review of relevant literature we discuss their characteristics and place into multi-channel models of service delivery. We argue that social robots......-channel models of service delivery. This is especially relevant given the current lack of evaluations of such models, the broad range of channels available, and their different stages of deployment at governments around the world. Nevertheless, social robots offer an potentially very relevant addition...

  9. Calcium Channel Blockers

    Science.gov (United States)

    ... Certain calcium channel blockers interact with grapefruit products. Kaplan NM, et al. Treatment of hypertension: Drug therapy. In: Kaplan's Clinical Hypertension. 11th ed. Philadelphia, Pa.: Wolters Kluwer ...

  10. A channel profile analyser

    International Nuclear Information System (INIS)

    Gobbur, S.G.

    1983-01-01

    It is well understood that due to the wide band noise present in a nuclear analog-to-digital converter, events at the boundaries of adjacent channels are shared. It is a difficult and laborious process to exactly find out the shape of the channels at the boundaries. A simple scheme has been developed for the direct display of channel shape of any type of ADC on a cathode ray oscilliscope display. This has been accomplished by sequentially incrementing the reference voltage of a precision pulse generator by a fraction of a channel and storing ADC data in alternative memory locations of a multichannel pulse height analyser. Alternative channels are needed due to the sharing at the boundaries of channels. In the flat region of the profile alternate memory locations are channels with zero counts and channels with the full scale counts. At the boundaries all memory locations will have counts. The shape of this is a direct display of the channel boundaries. (orig.)

  11. Tierra, palma africana y conflicto armado en el Bajo Atrato chocoano, Colombia. Una lectura desde el cambio en los órdenes de extracción

    Directory of Open Access Journals (Sweden)

    Paola García Reyes

    2014-01-01

    Full Text Available Desde la década de 1990 la región del Pacífico colombiano vive un proceso inédito de agudización del conflicto armado interno. Algunos estudios han descrito este hecho como una consecuencia no intencionada del reconocimiento de las poblaciones negras de la región como grupos étnicos propietarios de los territorios en los que habitan. En este artículo me pregunto de qué forma resultaron modificadas las dinámicas de conflicto en la subregión del Bajo Atrato chocoano (1985-2005 en Colombia, si esto se vincula con la explotación de sus recursos naturales, en particular la palma de aceite y cuál fue el papel que jugó en estas dinámicas el cambio en el régimen de propiedad de la tierra. Para responder a estas preguntas me baso en los estudios sobre la economía política de los conflictos armados e introduzco el concepto de órdenes de extracción con el fin de analizar las acciones de los actores del conflicto, los empresarios de la palma, el Estado como agente regulador y las poblaciones negras. Mi conclusión principal es que el cambio en la estructura de propiedad de la tierra no fue causa del conflicto y que el tipo de actor involucrado es una variable relevante.

  12. Inusual riqueza, composición y estructura arbórea en el bosque de tierra firme del Pongo Qoñec, Sur Oriente peruano

    Directory of Open Access Journals (Sweden)

    Isau Huamantupa-Chuquimaco

    2011-05-01

    Full Text Available Se estableció una parcela de 1 ha, en bosque de tierra firme en el Pongo de Qoñec, valle Kosñipata (Cusco, dentro de la Reserva Biósfera del Manú, a 710 m; 12°53'53"S y 72°22'25"W. Se registró 56 familias, 153 géneros, 249 especies con 813 individuos con Dap ≥ 10 cm. Las familias, más ricas fueron: Fabaceae (32 especies, Moraceae (24, Rubiaceae (17 y Lauraceae (12; los géneros más ricos, Inga (17, Neea (7, Miconia (5; se halló un área basal total de 40,50 m2, de ellas Iriartea deltoidea con 6,58 m2, Socratea salazarii 2,28 m2, y Endlicheria sp 1,65 m2, obtuvieron mayor ab; la especie con mayor valor de importancia fue: I. deltoidea, cor- roborando estudios anteriores en bosques de tierra firme. El análisis estructural muestra que clases diamétricas 10-20 cm, abarcan 71,3% del total de fustes. Al comparar nuestros resultados, el Pongo de Qoñec, sorpren- dentemente supera en riqueza a parcelas adyacentes dentro del sur peruano y muestra un patrón de riqueza de familias y géneros similar a parcelas peruanas diversas como Yanamono 300 especies y Mishana (289, en Loreto. Consideramos que esta inusual riqueza se debe en gran medida a factores ambientales únicos que se dan en este Pongo, como son la alta precipitación, dinámica de vientos y la variabilidad de suelos en áreas pequeñas. Por tanto estos resultados difieren considerablemente de enunciados conocidos, que consideran a la amazonia sur peruana con moderada a baja riqueza arbórea.

  13. Methodology for evaluating the grounding system in electrical substations; Metodologia para la evaluacion del sistema de puesta a tierra en subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Torrelles Rivas, L.F [Universidad Nacional Experimental Politecnica: Antonio Jose de Sucre (UNEXPO), Guayana, Bolivar (Venezuela)]. E-mail: torrellesluis@gmail.com; Alvarez, P. [Petroleos de Venezuela S.A (PDVSA), Maturin, Monagas (Venezuela)]. E-mail: alvarezph@pdvsa.com

    2013-03-15

    The present work proposes a methodology for evaluating grounding systems in electrical substations from medium and high voltage, in order to diagnose the state of the elements of the grounding system and the corresponding electrical variables. The assessment methodology developed includes a visual inspection phase to the elements of the substation. Then, by performing measurements and data analysis, the electrical continuity between the components of the substation and the mesh ground is verified, the soil resistivity and resistance of the mesh. Also included in the methodology the calculation of the step and touch voltage of the substation, based on the criteria of the International IEEE standards. We study the case of the 115 kV Pirital Substation belonging to PDVSA Oriente Transmission Network. [Spanish] En el presente trabajo se plantea una metodologia para la evaluacion de sistemas de puesta a tierra en subestaciones electricas de media y alta tension, con la finalidad de diagnosticar el estado de los elementos que conforman dicho sistema y las variables electricas correspondientes. La metodologia de evaluacion desarrollada incluye una fase de inspeccion visual de los elementos que conforman la subestacion. Luego, mediante la ejecucion de mediciones y analisis de datos, se verifica la continuidad electrica entre los componentes de la subestacion y la malla de puesta a tierra, la resistividad del suelo y resistencia de la malla. Se incluye tambien en la metodologia el calculo de las tensiones de paso y de toque de la subestacion, segun lo fundamentado en los criterios de los estandares Internacionales IEEE. Se estudia el caso de la Subestacion Pirital 115 kV perteneciente a la Red de Transmision de PDVSA Oriente.

  14. VOCES EN EL BOSQUE: EL USO DE RECURSOS VEGETALES ENTRE CAZADORES-RECOLECTORES DE LA ZONA CENTRAL DE TIERRA DEL FUEGO

    Directory of Open Access Journals (Sweden)

    Laura Caruso

    2008-01-01

    Full Text Available Se estudiaron las modalidades de aprovechamiento de las plantas entre los Selknam de Tierra del Fuego (Argentina y se presentan aquí los resultados obtenidos a partir del análisis de los restos de madera carbonizada y sin carbonizar del sitito Ewan, ocupado a principios del siglo XX para la realización de un ritual de iniciación. Los resultados permitieron una mejor comprensión de las estrategias de aprovechamiento de las plantas entre las sociedades cazadoras-recolectoras. La identificación de las especies empleadas y el registro de las principales características morfométricas permitió documentar el aprovechamiento del "ñire" (Nothofagus antarctica. Esta especie, dominante en el entorno, fue utilizada para la construcción de la vivienda y como combustible. En ambos casos se seleccionaron troncos de forma y tamaño adecuados. Los resultados del trabajo arqueobotánico y su confrontación con los datos etnográficos evidenciaron la importancia de los recursos vegetales dentro de la dinámica socioeconómica de este grupo humano. Los recursos vegetales, más allá de su rol alimentario, fueron relevantes en otros aspectos tales como la tecnología, la construcción, el combustible y debieron constituir una ventaja considerable en el ámbito de los bosques de la zona central de Tierra del Fuego.

  15. Patrones de distribución de especies arbóreas de dosel y sotobosque a escala local en bosques de tierra firme, Amazonia colombiana

    Directory of Open Access Journals (Sweden)

    Juan Sebastian Barreto-Silva

    2014-03-01

    Full Text Available El efecto de la variación ambiental en la estructura de las comunidades arbóreas en bosques tropicales, aún se debate. En paisajes como los bosques de tierra firme, donde el gradiente ambiental disminuye, el efecto de los suelos sobre los patrones de distribución de especies es mínimo. En contraste, un mayor efecto de la variación edáfica y topográfica sobre la composición florística, se ha reportado en estudios con diferentes tipos de plantas en bosques tropicales. Este estudio se realizó en diez hectáreas de una parcela permanente. Se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas a escala local, según el estado de desarrollo y categorías de abundancia relativa. Se registraron 14 074 individuos de 1 053 especies y 80 familias. Los suelos son ácidos, presentan altas concentraciones de Aluminio y son predominantemente arcillosos. La diversidad beta fue baja. Las diferencias florísticas explicadas fueron asociadas con procesos biológicos espacialmente estructurados, particularmente, con la limitación en dispersión. Aunque, la mayor parte de la variación no fue explicada por las variables consideradas. Estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación florística en bosques de tierra firme de la amazonia.

  16. Influencia de informalidad en titulación de tierras y planificación productiva, en cadenas agroexportadoras del Valle del Mantaro, Perú

    Directory of Open Access Journals (Sweden)

    William Rodríguez Giráldez

    2015-06-01

    Full Text Available El objetivo fue determinar la influencia de la informalidad en la titulación de tierras sobre la planificación productiva en cadenas agroexportadoras del Valle del Mantaro. Investigación de alcance descriptivo-correlacional, no experimental, transeccional. Fueron encuestados 383 productores agrícolas de las provincias que comprenden el Valle del Mantaro: Huancayo, Concepción, Jauja y Chupaca. Se utilizaron estadísticos descriptivos como, distribución de frecuencias, tablas de contingencia, y ji al cuadrado para prueba de hipótesis. Entre los resultados se tiene que, 1 En informalidad en titulación de tierras, 61 % de productores tienen título de propiedad y 2 % en trámite; 95,7 % saben de beneficios del título de propiedad; 55 % manifiestan que terrenos son de su propiedad; 45 % consideran que parte de sus terrenos los alquilan; 2 En planificación productiva, 52 % de productores deciden qué sembrar en función a la demanda y mejor precio de mercado, 62 % mejoraron resultados gracias a la planificación, 23 % lograron metas de producción entre el 75 % y 100 %, solo 19 % mejoraron su productividad esperada y 47 % mejoraron rangos inferiores a 25 %; además el 87 % consideran que en la planificación de la producción deben participar productores y empresas. En conclusión, participar en cadenas productivas no depende de la tenencia de terrenos con título de propiedad. El trabajo asociativo no depende de la decisión de sembrar, de la planificación, de mejoras de productividad, ni de participación en procesos de planificación.

  17. A linearization of quantum channels

    Science.gov (United States)

    Crowder, Tanner

    2015-06-01

    Because the quantum channels form a compact, convex set, we can express any quantum channel as a convex combination of extremal channels. We give a Euclidean representation for the channels whose inverses are also valid channels; these are a subset of the extreme points. They form a compact, connected Lie group, and we calculate its Lie algebra. Lastly, we calculate a maximal torus for the group and provide a constructive approach to decomposing any invertible channel into a product of elementary channels.

  18. Omni channel fashion shopping

    NARCIS (Netherlands)

    Kemperman, A.D.A.M.; van Delft, L.; Borgers, A.W.J.; Pantano, E.

    2015-01-01

    This chapter gives insight into consumers' online and offline fashion shopping behavior, consumers' omni-channel usage during the shopping process, and consumer fashion shopper segments. Based on a literature review, omni-channel shopping behavior during the shopping process was operationalized.

  19. Channel electron multipliers

    International Nuclear Information System (INIS)

    Seidman, A.; Avrahami, Z.; Sheinfux, B.; Grinberg, J.

    1976-01-01

    A channel electron multiplier is described having a tubular wall coated with a secondary-electron emitting material and including an electric field for accelerating the electrons, the electric field comprising a plurality of low-resistive conductive rings each alternating with a high-resistive insulating ring. The thickness of the low-resistive rings is many times larger than that of the high-resistive rings, being in the order of tens of microns for the low-resistive rings and at least one order of magnitude lower for the high-resistive rings; and the diameter of the channel tubular walls is also many times larger than the thickness of the high-resistive rings. Both single-channel and multiple-channel electron multipliers are described. A very important advantage, particularly in making multiple-channel multipliers, is the simplicity of the procedure that may be used in constructing such multipliers. Other operational advantages are described

  20. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

    2014-01-01

    About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... drive the late repolarization of the ventricle with some redundancy, and in atria this repolarization reserve is supplemented by the fairly atrial-specific KV1.5, Kir3, KCa, and K2P channels. The role of the latter two subtypes in atria is currently being clarified, and several findings indicate...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...

  1. Cl- channels in apoptosis

    DEFF Research Database (Denmark)

    Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida

    2016-01-01

    A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also......(-) channels or as regulators of other apoptotic Cl(-) channels, such as LRRC8. CFTR has been known for its proapoptotic effects for some time, and this effect may be based on glutathione release from the cell and increase in cytosolic reactive oxygen species (ROS). Although we find that CFTR is activated...

  2. CHANNEL ESTIMATION TECHNIQUE

    DEFF Research Database (Denmark)

    2015-01-01

    A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over the communicat......A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over...... the communication channel. The method further includes determining a sequence of second coefficient estimates of the communication channel based on a decomposition of the first coefficient estimates in a dictionary matrix and a sparse vector of the second coefficient estimates, the dictionary matrix including...... filter characteristics of at least one known transceiver filter arranged in the communication channel....

  3. Identificación de los mecanismos subyacentes a la invasión de Castor canadensis (Rodentia en el archipiélago de Tierra del Fuego, Chile Identifying the mechanisms underlying the invasion of Castor canadensis (Rodentia into Tierra del Fuego archipelago, Chile

    Directory of Open Access Journals (Sweden)

    PETRA K WALLEM

    2007-09-01

    Full Text Available Castor canadensis es considerado un ingeniero ecosistémico arquetípico, ya que altera el estado de factores bióticos y abióticos, mediante interacciones no tróficas, modificando sustancialmente los ecosistemas que habita. Esta especie fue introducida en la Isla Grande de Tierra del Fuego en 1946 por el gobierno argentino, con el fin de estimular la industria peletera. Actualmente se encuentra presente en las principales islas del archipiélago, incluyendo Tierra del Fuego, Navarino, Dawson y Hoste y ocupando habitat tan contrastantes como los bosques subpolares magallánicos, el matorral y la estepa patagónica. Su éxito en estos habitat sugiere que su expansión solo se verá limitada por la disponibilidad de recursos hídricos. De acuerdo a lo observado en Tierra del Fuego, en ausencia de un programa de control poblacional, los castores amenazan con establecerse en todos los bosques templados nativos del continente (entre los 35 y 55° S y ocupar los habitat de matorral y pastizal circundantes a los mismos. El presente artículo propone tres hipótesis referentes a los mecanismos subyacentes al éxito de esta invasión: el escape de enemigos naturales, la oportunidad de recursos, y la autofacilitación mediante interacciones no tróficas. Los antecedentes disponibles develan patrones conductuales (e.g., el establecimiento de colonias en forma independiente de la cercanía de recursos maderables, un aparente crecimiento poblacional irruptivo, así como una explotación centrada en Nothofagus pumilio, especie dominante en los bosques magallánicos que sugieren la operación de los mecanismos de escape de enemigos naturales y oportunidad de recursos. También se observa una mayor densidad de colonias activas en habitat que presentan mayor extensión de modificación ambiental, sugiriendo el accionar del mecanismo de autofacilitación. Si bien la información reunida no permite poner a prueba las hipótesis propuestas, sí entrega un marco

  4. Coherifying quantum channels

    Science.gov (United States)

    Korzekwa, Kamil; Czachórski, Stanisław; Puchała, Zbigniew; Życzkowski, Karol

    2018-04-01

    Is it always possible to explain random stochastic transitions between states of a finite-dimensional system as arising from the deterministic quantum evolution of the system? If not, then what is the minimal amount of randomness required by quantum theory to explain a given stochastic process? Here, we address this problem by studying possible coherifications of a quantum channel Φ, i.e., we look for channels {{{Φ }}}{ \\mathcal C } that induce the same classical transitions T, but are ‘more coherent’. To quantify the coherence of a channel Φ we measure the coherence of the corresponding Jamiołkowski state J Φ. We show that the classical transition matrix T can be coherified to reversible unitary dynamics if and only if T is unistochastic. Otherwise the Jamiołkowski state {J}{{Φ }}{ \\mathcal C } of the optimally coherified channel is mixed, and the dynamics must necessarily be irreversible. To assess the extent to which an optimal process {{{Φ }}}{ \\mathcal C } is indeterministic we find explicit bounds on the entropy and purity of {J}{{Φ }}{ \\mathcal C }, and relate the latter to the unitarity of {{{Φ }}}{ \\mathcal C }. We also find optimal coherifications for several classes of channels, including all one-qubit channels. Finally, we provide a non-optimal coherification procedure that works for an arbitrary channel Φ and reduces its rank (the minimal number of required Kraus operators) from {d}2 to d.

  5. CANDU channel flow verification

    International Nuclear Information System (INIS)

    Mazalu, N.; Negut, Gh.

    1997-01-01

    The purpose of this evaluation was to obtain accurate information on each channel flow that enables us to assess precisely the level of reactor thermal power and, for reasons of safety, to establish which channel is boiling. In order to assess the channel flow parameters, computer simulations were done with the NUCIRC code and the results were checked by measurements. The complete channel flow measurements were made in the zero power cold condition. In hot conditions there were made flow measurements using the Shut Down System 1 (SDS 1) flow devices from 0.1 % F.P. up to 100 % F.P. The NUCIRC prediction for CANDU channel flows and the measurements by Ultrasonic Flow Meter at zero power cold conditions and SDS 1 flow channel measurements at different reactor power levels showed an acceptable agreement. The 100 % F.P. average errors for channel flow of R, shows that suitable NUCIRC flow assessment can be made. So, it can be done a fair prediction of the reactor power distribution. NUCIRC can predict accurately the onset of boiling and helps to warn at the possible power instabilities at high powers or it can detect the flow blockages. The thermal hydraulic analyst has in NUCIRC a suitable tool to do accurate predictions for the thermal hydraulic parameters for different steady state power levels which subsequently leads to an optimal CANDU reactor operation. (authors)

  6. Reconfigurable virtual electrowetting channels.

    Science.gov (United States)

    Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

    2012-02-21

    Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

  7. Evaluation channel performance in multichannel environments

    NARCIS (Netherlands)

    Gensler, S.; Dekimpe, M.; Skiera, B.

    2007-01-01

    Evaluating channel performance is crucial for actively managing multiple sales channels, and requires understanding the customers' channel preferences. Two key components of channel performance are (i) the existing customers' intrinsic loyalty to a particular channel and (ii) the channel's ability

  8. Channel follower leakage restrictor

    International Nuclear Information System (INIS)

    Williamson, H.E.; Smith, B.A.

    1977-01-01

    An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures

  9. Distribución de tierras raras en soluciones y coloides de un sistema natural de aguas ácidas (Arroyo del Val, Zaragoza

    Directory of Open Access Journals (Sweden)

    López Julián, P. L.

    1993-04-01

    presentan los primeros resultados obtenidos sobre las concentraciones de tierras raras (REE de estas aguas ácidas (en muestras filtradas a través de mallas de 0,1 I-tm y en los coloides asociados. Las pautas de tierras raras (normalizadas frente a NASC de las aguas ácidas analizadas presentan globalmente un enriquecimiento relativo de las tierras taras pesadas (HREE respecto a las ligeras (LREE, con relaciones Lun/Lan ≈ 2. No obstante, lo más llamativo de estas pautas es el considerable enriquecimiento en las tierras raras intermedias (IREE representadas por Eu, Gd y Tb. Ello provoca que, en detalle, las pautas obtenidas para estas aguas puedan caracterizarse por un enriquecimiento en las tierras raras más pesadas desde La a Gd y por un empobrecimiento, también respecto a las más pesadas, entre Gd y Lu. Los contenidos de REE de los geles analizados son considerablemente superiores a los determinados en las aguas, presentando enriquecimientos de hasta tres y cuatro órdenes de magnitud. Las pautas de REE obtenidas para estos geles, tomados en distintos puntos del curso del Arroyo del Val, son considerablemente diferentes. La del coloide muestreado en el mismo punto que las aguas analizadas es similar a la de las soluciones, con una marcada convexidad para los IREE; la del otro gel, tomado aguas abajo respecto al anterior, presenta un perfil mucho más plano aunque todavía ligeramente convexo para los IREE. Aparentemente, el proceso de floculación coloidal observado en la primera confluencia del Arroyo del Val con un afluente de aguas neutras provoca una considerable disminución de las REE transportadas por las aguas ácidas (hasta un SO %. Yen ese punto, el coloide floculado presenta un enriquecimiento relativo en HREE respecto al observado en las aguas antes y en el punto de floculación.

  10. Conversation with Lara about the Earth and Land. (Spanish Title: Conversando con Lara sobre la Tierra y la Teirra.) Conversando com Lara sobre a Terra e a Terra

    Science.gov (United States)

    da Conceição Barbosa-Lima, Maria

    2010-12-01

    The present article is the analysis of a conversation between the author and Lara, a four-yearold- girl, enrolled in nursery school, while she makes a drawing of the Earth. It took place outside school environment and without any other person around to avoid interference during the interview. According to Ferreira & Silva (2004), a researcher can only comprehend a child's drawing, or form, by listening to him/her while he/she is creating it. Lara presented the traditional flat drawing, picturing the sky parallel to the ground, as reported by Nardi & Carvalho (1996). However, when asked to draw the World - term used by Butterworth et al. (2002), in order to avoid unnecessary confusion - she represented it by a circle, with herself on the surface. Her drawings led to the conclusion that such girl does not know yet the World in which she lives is the Earth, and probably because of that, within her age and consequent maturity, she accurately differentiates the concepts of land and Earth. El presente artículo analiza una entrevista libre, mientras una niña de 4 años y 4 meses, matriculada en el pregrado, dibuja la Tierra. Esta entrevista se realizó fuera del ambiente escolar y sin otra persona alrededor que pudiera interferir. De acuerdo con Ferreira Silva (2004), para quien investiga es posible conocer realmente lo que un niño o una niña pone en el papel a través de grafismos y/o dibujos si se lo escucha durante el proceso de creación de la escritura con imágenes. La niña, en este caso, representa la Tierra con el tradicional dibujo plano y el "cielo" paralelo al suelo, conforme analizaron Nardi & Carvalho (1996). Pero, cuando se Le solicita dibujar el "Mundo" - palabra empleada en un trabajo de Butterworth et al. (2002), con intención de no provocar "confusiones" innecesarias a sus sujetos de investigación- lo representa de forma circular, poniéndose sobre su superficie. Sus dibujos llevan a concluir que esta niña aún no tiene conocimiento que el mundo

  11. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  12. Diseño y Aplicación de Métodos para Evaluar Patologías Constructivas en el Hábitat Rural. Arquitectura de Tierra en el Noroeste Argentino

    Directory of Open Access Journals (Sweden)

    Rodolfo Rotondaro

    2004-01-01

    Full Text Available Se proponen una serie de instrumentos y procedimientos simples de gabinete y laboratorio para monitorear cuantitativa y cualitativamente los deterioros constructivos de edificios de tierra en ámbitos rurales. Los edificios elegidos son patrimoniales, materialmente similares y pertenecen al impulso constructivo colonial, valores que incentivan el estudio pormenorizado de la interacción ambiente-edificio. Esta investigación arroja interesantes resultados sobre la durabilidad de las construcciones de tierra. Además permite comparar patrones de comportamiento de este tipo de construcciones en distintos ambientes. También se evalúan los métodos empleados y se interpretan los deterioros cronológicamente, en el marco de un estudio de tipo comparativo de patologías constructivas.

  13. LA TEORÍA DE VON THUNEN SOBRE LA INFLUENCIA DE LA DISTANCIA AL MERCADO EN RELACIÓN A LA UTILIZACIÓN DE LA TIERRA. SU APLICACIÓN A COSTA RICA

    OpenAIRE

    Waibel, Leo

    2011-01-01

    El problema fundamental de Brasil actual es la colonización, la cual es estudiada por el geógrafo bajo dos puntos: i) las áreas que deben ser pobladas, y ii) el tipo de aprovechamiento de la tierra que debe ser  adoptado…El primero es un problema de geografía física; el otro, de geografía económica y economía rural. Dependiendo la utilización de la tierra, en gran parte, de la distancia al centro de consumo o exportación, el estudio de esa dependencia especial significación para el Brasil. Fu...

  14. Many channel spectrum unfolding

    International Nuclear Information System (INIS)

    Najzer, M.; Glumac, B.; Pauko, M.

    1980-01-01

    The principle of the ITER unfolding code as used for the many channel spectrum unfolding is described. Its unfolding ability is tested on seven typical neutron spectra. The effect of the initial spectrum approximation upon the solution is discussed

  15. Channelized Streams in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This draft dataset consists of all ditches or channelized pieces of stream that could be identified using three input datasets; namely the1:24,000 National...

  16. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  17. Sensing with Ion Channels

    CERN Document Server

    Martinac, Boris

    2008-01-01

    All living cells are able to detect and translate environmental stimuli into biologically meaningful signals. Sensations of touch, hearing, sight, taste, smell or pain are essential to the survival of all living organisms. The importance of sensory input for the existence of life thus justifies the effort made to understand its molecular origins. Sensing with Ion Channels focuses on ion channels as key molecules enabling biological systems to sense and process the physical and chemical stimuli that act upon cells in their living environment. Its aim is to serve as a reference to ion channel specialists and as a source of new information to non specialists who want to learn about the structural and functional diversity of ion channels and their role in sensory physiology.

  18. Calcium channel blocker poisoning

    Directory of Open Access Journals (Sweden)

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  19. TRP channels: an overview

    DEFF Research Database (Denmark)

    Pedersen, Stine Falsig; Owsianik, Grzegorz; Nilius, Bernd

    2005-01-01

    The TRP ("transient receptor potential") family of ion channels now comprises more than 30 cation channels, most of which are permeable for Ca2+, and some also for Mg2+. On the basis of sequence homology, the TRP family can be divided in seven main subfamilies: the TRPC ('Canonical') family......, the TRPV ('Vanilloid') family, the TRPM ('Melastatin') family, the TRPP ('Polycystin') family, the TRPML ('Mucolipin') family, the TRPA ('Ankyrin') family, and the TRPN ('NOMPC') family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading...... to a plethora of data on the roles of TRPs in a variety of tissues and species, including mammals, insects, and yeast. The present review summarizes the most pertinent recent evidence regarding the structural and functional properties of TRP channels, focusing on the regulation and physiology of mammalian TRPs....

  20. Informes de la construcción, Nº 523 monográfico La tierra material de construcción : una aproximación contemporánea

    OpenAIRE

    Bestraten Castells, Sandra Cinta; Hormias Laperal, Emilio

    2011-01-01

    Este documento recoge la actualidad de la arquitectura en tierra, incorporndo las novedades tecnológicas del sector, las últimas investigaciones en universidades de varios paises y los principales centros de referencia en el estudio de este campo. La publicación ha sido coordinada desde la Universidad Poltitécnica de Cataluña por los autores de la presente comunicación

  1. Authentication over Noisy Channels

    OpenAIRE

    Lai, Lifeng; Gamal, Hesham El; Poor, H. Vincent

    2008-01-01

    In this work, message authentication over noisy channels is studied. The model developed in this paper is the authentication theory counterpart of Wyner's wiretap channel model. Two types of opponent attacks, namely impersonation attacks and substitution attacks, are investigated for both single message and multiple message authentication scenarios. For each scenario, information theoretic lower and upper bounds on the opponent's success probability are derived. Remarkably, in both scenarios,...

  2. Channelling versus inversion

    DEFF Research Database (Denmark)

    Gale, A.S.; Surlyk, Finn; Anderskouv, Kresten

    2013-01-01

    Evidence from regional stratigraphical patterns in Santonian−Campanian chalk is used to infer the presence of a very broad channel system (5 km across) with a depth of at least 50 m, running NNW−SSE across the eastern Isle of Wight; only the western part of the channel wall and fill is exposed. W......−Campanian chalks in the eastern Isle of Wight, involving penecontemporaneous tectonic inversion of the underlying basement structure, are rejected....

  3. Stream Channel Stability.

    Science.gov (United States)

    1981-04-01

    Cycles of wetting and drying are also t ,v itiue swelling and shrinkage of the soil. S 11ied blocks or peds of soil fabric ,,ks. id downslope soil creep ...hydrographs of water and sediment at the point in question. By feeding the output from the hydrology-transport model into the finite element model...the banks as undercut banks fail. Channel irregularities such as seepage zones, cattle crossings, overbank drainage, buried channels, organic deposits

  4. Channeling and dynamic chaos

    Energy Technology Data Exchange (ETDEWEB)

    Bolotin, IU L; Gonchar, V IU; Truten, V I; Shulga, N F

    1986-01-01

    It is shown that axial channeling of relativistic electrons can give rise to the effect of dynamic chaos which involves essentially chaotic motion of a particle in the channel. The conditions leading to the effect of dynamic chaos and the manifestations of this effect in physical processes associated with the passage of particles through a crystal are examined using a silicon crystal as an example. 7 references.

  5. Southern pulpwood production, 1962

    Science.gov (United States)

    Joe F. Christopher; Martha E. Nelson

    1963-01-01

    Pulpwood production in the south rose to an all-time high of 25,586,300 cords in 1962-58 percent of the Nation's total. At the year's end, 80 southern pulpmills were operating; their combined daily pulping capacity was more than 52,000 tons. Nine mills outside the region were using wood grown in the South.

  6. Multilingualism in Southern Africa.

    Science.gov (United States)

    Peirce, Bonny Norton; Ridge, Stanley G. M.

    1997-01-01

    Reviews recent research in multilingualism in Southern Africa, focusing on the role of languages in education, sociolinguistics, and language policy. Much of the research is on South Africa. Topics discussed include language of instruction in schools, teacher education, higher education, adult literacy, language contact, gender and linguistic…

  7. NREL + Southern California Gas

    Energy Technology Data Exchange (ETDEWEB)

    Berdahl, Sonja E [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-09

    NREL and Southern California Gas Company are evaluating a new 'power-to-gas' approach - one that produces methane through a biological pathway and uses the expansive natural gas infrastructure to store it. This approach has the potential to change how the power industry approaches renewable generation and energy storage.

  8. Course on Ionic Channels

    CERN Document Server

    1986-01-01

    This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe­ cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single­ channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re­ lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem­ brane preparations and the use of membrane vesicles and optical tech­ niques in the stUGY of ionic channels a...

  9. DOMINANCIA FLORÍSTICA Y VARIABILIDAD ESTRUCTURAL EN BOSQUES DE TIERRA FIRME EN EL NOROCCIDENTE DE LA AMAZONÍA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    DUQUE ÁLVARO

    2003-06-01

    Full Text Available Se presenta un estudio de la vegetación en 3.1 ha de bosque distribuidos en 3 unidadesfisiográficas: coluvios derivados de superficies de areniscas, superficies terciarias y superficiesaluviales de origen de ríos amazonenses, en un área ubicada entre el río Yarí y el sectorsuroriental de la serranía de Chiribiquete, departamento de Caquetá, Amazonía colombiana.El número de especies de plantas vasculares con DAP > 10 cm en parcelasde 0.1 ha osciló entre 25 y 60, mientras que la diversidad (número de especies/número deindividuos varió entre 0.31 y 0.94. Mediante un análisis de componentes principales se identificarontres tipos estructurales de bosque, pero sin una clara relación con la variabilidadfisiográfica en el área. Oenocarpus bataua y Clathrotropis macrocarpa fueron las especiesmás abundantes en todas las unidades fisiográficas. De acuerdo con el análisis de coordenadaspolares, las superficies terciarias y las superficies aluviales de ríos de aguas oscuras,fueron entre sí similares florísticamente, mientras que los coluvios de las mesas deareniscas muestran una ligera tendencia hacia una mayor disimilitud florística. Seconcluye que los bosques de la Amazonía colombiana son tan ricos en especiescomo los registrados en la Amazonía ecuatoriana y peruana, aunque se aprecia unaclara diferencia florística entre los bosques de tierra firme del piedemonte amazónicoen Ecuador y Perú, y los bosques del norte de la Amazonía colombiana. Los resultadosde este estudio apoyan la idea de que la especialización edáfica de las especiesarbóreas en bosques de tierra firme bien drenada en la Amazonía noroccidental es muy baja.

  10. Ruta de producción Casa en tierra ajena. Documental sobre migración forzada en Centroamérica

    Directory of Open Access Journals (Sweden)

    Ivannia Villalobos Vindas

    2017-11-01

    Full Text Available La Universidad Estatal a Distancia (UNED, a sus 40 años de ser fundada, acumula una experiencia de producción de material didáctico del género documental de gran calidad, tanto a nivel del país como de la región. Esto ha sido reconocido en los más de 40 premios o reconocimientos nacionales e internacionales hacia la producción realizada concretamente desde el Programa de Producción de Material Audiovisual (PPMA. Cada proceso de producción audiovisual tiene sus ritmos y particularidades. En el siguiente artículo se exponen las etapas y decisiones clave en la ruta de producción del documental sobre migración forzada en Centroamérica Casa en tierra ajena, una producción de la Universidad Estatal a Distancia (UNED y la Universidad de Costa Rica (UCR, con el apoyo financiero del Consejo Nacional de Rectores (CONARE. En el año del 40 aniversario de la UNED, se estrenó Casa en tierra ajena, el primer largometraje documental realizado por la UNED con una escala de producción y grabación que abarca Centroamérica y México, el cual continúa con el compromiso e impacto característico de las producciones UNED, la difusión y el impacto global. Como herramienta de aprendizaje, este artículo aborda los aspectos relacionados con los factores que influyeron en la construcción del proyecto y los objetivos del equipo de producción en un documental educativo y de incidencia social. Además, se describen los momentos o decisiones clave en las etapas de preproducción, producción y posproducción que condujeron a un proceso de producción riguroso en lo académico y sensible en la dimensión humana.

  11. La llegada de inmigrantes a Isla de Tierra en Alhucemas: Crisis migratoria entre España y Marruecos y violaciones de derechos humanos

    Directory of Open Access Journals (Sweden)

    Inmaculada González García

    2014-06-01

    Full Text Available Nuevas cuestiones de naturaleza jurídica se han planteado tras la llegada masiva de inmigrantes subsaharianos a las Islas y Peñones españoles en el Norte de África, en concreto, a la Isla de Tierra en 2012. En este caso, la reclamación territorial marroquí de dichos territorios no ha sido un obstáculo para cooperar con España en la lucha contra la inmigración irregular, si bien planteamos la violación por ambos países de las normas nacionales e internacionales en materia de protección de los derechos humanos y de las garantías procesales en los procedimientos de expulsión/devolución de inmigrantes. Analizaremos, en primer lugar, la falta de claridad del estatuto jurídico de la Isla de Tierra y su incidencia en el ejercicio de las competencias soberanas por parte de España en el control de las fronteras europeas en el Norte de África. Por otra parte, cuestionaremos la validez del acuerdo hispano-marroquí de readmisión de inmigrantes entrados de forma irregular de 1992 y, finalmente, analizaremos la violación de los derechos humanos de los inmigrantes y las denuncias presentadas por Organizaciones No Gubernamentales (ONG ante instancias nacionales (el Defensor del pueblo español e internacionales (como el Comité contra la Tortura de la Organización de las Naciones Unidas –ONU- o el Tribunal Europeo de Derechos Humanos –TEDH- del Consejo de Europa. Destacaremos principalmente las normas que los Estados deben aplicar en el control de fronteras y en la lucha contra la inmigración irregular, habiéndose constatado internamente, y es probable que se haga también en el plano internacional, la violación de las garantías procesales y los derechos humanos de los inmigrantes

  12. Efecto de diferentes usos de la tierra en la composición y la abundancia de la macrofauna edáfica, en la provincia de Matanzas

    Directory of Open Access Journals (Sweden)

    Y García

    Full Text Available Se evaluó el efecto de cuatro sistemas de uso de la tierra en la riqueza y la abundancia de la macrofauna edáfica, durante el periodo lluvioso (junio-octubre del año 2011, en los municipios de Colón, Calimete y Perico (provincia de Matanzas, Cuba. El muestreo de la macrofauna se realizó según la Metodología del Programa de Investigación Internacional Biología y Fertilidad del Suelo Tropical (TSBF. Los sistemas evaluados fueron: cultivos varios (suelos con 10 años -o más- de explotación intensiva, fincas agropecuarias (suelos con más de cinco años de explotación, con laboreo mínimo y con fertilización orgánica e inorgánica, silvopastoril (suelos con más de 10 años de explotación y con una carga global de ganado vacuno entre 1,7 y 1,8 UGM/ha y pastizal (suelos con más de 10 años de explotación y con una carga global de ganado vacuno entre 1,3 y 1,5 UGM/ha. Los mayores valores de densidad y biomasa se obtuvieron en los sistemas menos perturbados, siguiendo el gradiente: silvopastoril-pastizal-fincas agropecuarias-cultivos varios. La densidad solo fue sensible en los sistemas donde hubo un contraste en cuanto a la diversidad y los estratos de vegetación. La biomasa reflejó los cambios en los diferentes usos y en el manejo de los suelos. Se demostró que los distintos usos de la tierra, así como el grado de perturbación e intensidad del manejo, influyeron en la composición y la abundancia de la macrofauna edáfica.

  13. Ion channelling in diamond

    International Nuclear Information System (INIS)

    Derry, T.E.

    1978-06-01

    Diamond is one of the most extreme cases from a channelling point of view, having the smallest thermal vibration amplitude and the lowest atomic number of commonly-encountered crystals. These are the two parameters most important for determining channelling behaviour. It is of consiberable interest therefore to see how well the theories explaining and predicting the channeling properties of other substance, succeed with diamond. Natural diamond, although the best available form for these experiments, is rather variable in its physical properties. Part of the project was devoted to considering and solving the problem of obtaining reproducible results representative of the ideal crystal. Channelling studies were performed on several good crystals, using the Rutherford backscattering method. Critical angles for proton channelling were measured for incident energies from 0.6 to 4.5 MeV, in the three most open axes and three most open planes of the diamond structure, and for α-particle channelling at 0.7 and 1.0 MeV (He + ) in the same axes and planes. For 1.0 MeV protons, the crystal temperature was varied from 20 degrees Celsius to 700 degrees Celsius. The results are presented as curves of backscattered yield versus angle in the region of each axis or plane, and summarised in the form of tables and graphs. Generally the critical angles, axial minimum yields, and temperature dependence are well predicted by the accepted theories. The most valuable overall conclusion is that the mean thermal vibration amplitude of the atoms in a crytical determines the critical approach distance to the channel walls at which an ion can remain channelled, even when this distance is much smaller than the Thomas-Fermi screening distance of the atomic potential, as is the case in diamond. A brief study was made of the radiation damage caused by α-particle bombardment, via its effect on the channelling phenomenon. It was possible to hold damage down to negligible levels during the

  14. Optical Communications Channel Combiner

    Science.gov (United States)

    Quirk, Kevin J.; Quirk, Kevin J.; Nguyen, Danh H.; Nguyen, Huy

    2012-01-01

    NASA has identified deep-space optical communications links as an integral part of a unified space communication network in order to provide data rates in excess of 100 Mb/s. The distances and limited power inherent in a deep-space optical downlink necessitate the use of photon-counting detectors and a power-efficient modulation such as pulse position modulation (PPM). For the output of each photodetector, whether from a separate telescope or a portion of the detection area, a communication receiver estimates a log-likelihood ratio for each PPM slot. To realize the full effective aperture of these receivers, their outputs must be combined prior to information decoding. A channel combiner was developed to synchronize the log-likelihood ratio (LLR) sequences of multiple receivers, and then combines these into a single LLR sequence for information decoding. The channel combiner synchronizes the LLR sequences of up to three receivers and then combines these into a single LLR sequence for output. The channel combiner has three channel inputs, each of which takes as input a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The cross-correlation between the channels LLR time series are calculated and used to synchronize the sequences prior to combining. The output of the channel combiner is a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The unit is controlled through a 1 Gb/s Ethernet UDP/IP interface. A deep-space optical communication link has not yet been demonstrated. This ground-station channel combiner was developed to demonstrate this capability and is unique in its ability to process such a signal.

  15. Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?

    Science.gov (United States)

    Rodriguez, J Alexis P; Kargel, Jeffrey S; Baker, Victor R; Gulick, Virginia C; Berman, Daniel C; Fairén, Alberto G; Linares, Rogelio; Zarroca, Mario; Yan, Jianguo; Miyamoto, Hideaki; Glines, Natalie

    2015-09-08

    Catastrophic floods generated ~3.2 Ga by rapid groundwater evacuation scoured the Solar System's most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet's upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean [corrected]. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.

  16. Variación florística de especies arbóreas a escala local en un bosque de tierra firme en la Amazonia colombiana Floristic variation of canopy tree species at a local scale on tierra firme forests in colombian Amazonia

    Directory of Open Access Journals (Sweden)

    Juan Sebastian Barreto Silva

    2010-03-01

    Full Text Available El presente estudio se llevó a cabo en cinco hectáreas de una parcela permanente establecida en el Parque Nacional Amacayacu, Amazonia colombiana. En éste, se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas (DAP>10 cm a escala local en un bosque de tierra firme. Se estudió la variación florística y ambiental en cuadrantes de 20x20 m. Adicionalmente, se consideraron diferentes categorías de abundancia (total, alta, media y baja. Se utilizó el Análisis de Correspondencia Linealizado y el Análisis de Correspondencia Canónica, seguido de una partición de la variación, para cuantificar la magnitud a la cual el ambiente y la limitación en dispersión determinan la variación florística. La fracción espacial, representando procesos de autocorrelación como la limitación en dispersión, se analizó mediante dos métodos: Asumiendo un polinomio de tercer grado y por el método de Coordenadas Principales de Matrices Vecinas (PCNM. La diversidad beta de la parcela fue baja. El PCNM aparece como el método de análisis más apropiado para estudios a esta escala. Las diferencias florísticas explicadas a lo largo de la parcela de 5-ha fueron principalmente asociadas con procesos biológicos como la limitación en dispersión. La mayor parte de la variación florística, no obstante, no fue explicada por las variables ambientales o espaciales consideradas. En conclusión, estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación espacial de las especies arbóreas a escala local en tierra firme en los bosques en el Parque Nacional Amacayacu.This study was carried out in a 5-ha permanent plot established in the Amacayacu National Park, Colombian Amazonia. We assessed the extent at which floristic patterns of tree species were determined by either the environmental variation or the spatial configuration in tierra firme

  17. Channel Choice: A Literature Review

    DEFF Research Database (Denmark)

    Østergaard Madsen, Christian; Kræmmergaard, Pernille

    2015-01-01

    The channel choice branch of e-government studies citizens’ and businesses’ choice of channels for interacting with government, and how government organizations can integrate channels and migrate users towards the most cost-efficient channels. In spite of the valuable contributions offered...

  18. Channel Identification Machines

    Directory of Open Access Journals (Sweden)

    Aurel A. Lazar

    2012-01-01

    Full Text Available We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

  19. Channel identification machines.

    Science.gov (United States)

    Lazar, Aurel A; Slutskiy, Yevgeniy B

    2012-01-01

    We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s) onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS) with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

  20. Construction Management South-Ukrainian and North-Crimean channels in 1950−1953

    Directory of Open Access Journals (Sweden)

    Satskyi, P. V.

    2017-08-01

    Full Text Available In the current article the analysis of the mechanisms of the providing of management of the building process of the Southern-Ukrainian and Northern-Crimean channels in the command-administrative system of USSR during the late Stalinist period has been made. The building of Southern-Ukrainian and Northern-Crimea channels had a particular political value for USSR in the beginning of 1950s, while the realization of this project was supposed to create the prerequisites for the economic development of the Southern regions of Ukraine (until 1954 and the Northern regions of the Crimea. The General Directorate 'Ukrvodstroy" of the Ministry of Cotton of USSR was supposed to be responsible for the building of the Southern-Ukrainian and Northern-Crimean channels. However, the Ministry of Cotton as well as other union ministries turned out to be ineffective in the process of administering of "communism construction". On the other hand, the Council of Ministers of Ukrainian SSR and the Communist Party of the Soviet Union were very effective in providing of the building of the Southern-Ukrainian and Northern-Crimean channels. Due to the effective activity of the leadership of Ukrainian SSR related to the providing of the building of Southern-Ukrainian and Northern-Crimean channels, the revival of the social-economic development of the Crimea took place, particularly in the far end regions of the Crimea it happened due to the development of capital investments required for the program of channels building. Thus, the Council of Ministers of Ukrainian Soviet Socialist Republic and the Central Committee of Communist Party (Bolsheviks of Ukraine was actively expanding its territory competence on the territory of the Crimea.

  1. Mitología grecolatina y rock. El mito de Prometeo en letras de Extremoduro, Tierra Santa y Kutxi Romero & Ja ta Ja / Greek-latin mythology and rock. The myth of Prometheus in lyrics of Extremoduro, Tierra Santa and Kutxi Romero & Ja ta Ja

    Directory of Open Access Journals (Sweden)

    http://iesgtballester.juntaextremadura.net/web/profesores/tejuelo/vinculos/articulos/r17/04.pdf

    2013-06-01

    Full Text Available Resumen: A pesar de la creencia de que las letras de la música rock española actual están llenas de mensajes vacíos y de tópicos repetidos, podemos encontrar grupos y solistas cuyas composiciones se alejan de ese cliché para servir de vehículo de transmisión de cuestiones culturales como pueda ser la mitología clásica. Además, esta transmisión no siempre se queda en la mera anécdota de la cita culturalista, sino que en ocasiones va más allá, haciendo que el mito sirva como elemento de comparación o, incluso, recreándolo.Las siguientes páginas pasarán revista a la aparición del mito de Prometeo en las letras de tres grupos de rock nacional contemporáneos: Extremoduro, Tierra Santa y la colaboración entre el cantante y letrista de Marea, Kutxi Romero, con Ja ta Ja.Abstract: In spite of the belief that the lyrics of current Spanish rock music are full of empty messages and repeated topics, we can find groups and soloist whose compositions move away from that chiclé to serve as a transmission vehicle of cultural questions such as classical mythology. Besides, this transmission is not always just a mere anecdote of the culturalist quote, but on some occasions it goes further, making the myth an element of comparison, or even recreating it.The following pages will review the appearance of the Prometheus myth in the lyrics of three contemporary national rock groups: Extremoduro, Tierra Santa and the collaboration between the singer and composer of Marea, Kutxi Romero, with Ja ta Ja.

  2. Responsabilidad Social Matriz de indicadores sustentables que refleja el impacto de la forestación en tierras marginales del Partido de Bahía Blanca, Argentina

    Directory of Open Access Journals (Sweden)

    Regina del Carmen Durán Durán

    2009-01-01

    Full Text Available Actualmente, se han empezado a considerar otras obligaciones que tienen las empresas para con su comunidad; se trata de aspectos vinculados con las dimensiones sociales y ambientales. Desde este contexto, nuestro trabajo tiene como punto de partida el concepto de responsabilidad social desde la noción de sustentabilidad. El objetivo es evaluar la forestación como instrumento para mejorar la sostenibilidad de los sistemas productivos tradicionales en tierras marginales del Partido de Bahía Blanca, mitigando los impactos del desarrollo no responsable de la producción primaria. Para ello, se han identificado técnicas de manejo generadoras de externalidades positivas en otras actividades agropecuarias complementarias, donde existen limitantes edafológicas, apoyándose en las tres dimensiones del concepto de sustentabilidad: ecológica, económica, sociopolítica y cultural. De igual forma, se diseñó una matriz de evaluación y ponderación de impactos, que contempla indicadores cuantitativos y cualitativos, de cuya aplicación surge la forestación como una alternativa sustentable

  3. La cuestión de la tierra: el despojo y la posesión en el trabajo etnográfico

    Directory of Open Access Journals (Sweden)

    Meghan L. Morris

    2017-01-01

    Full Text Available En Colombia, el concepto de despojo ha ido tomando fuerza en espacios sociales, burocráticos y académicos. En este artícu - lo atiendo el llamado de Gillian Hart (2006 a mantener un compromiso con la com - prensión del despojo, que considere con - juntamente sus significados dispares y sus hechos materiales mediante la etnografía, a fin de construir conceptos que ayuden a entender la complejidad. Con base en el trabajo etnográfico llevado a cabo en Urabá, un sitio a menudo considerado como "em - blemático" del despojo, tomo las posibilida - des y límites del despojo como herramienta conceptual para entender las complejidades del conflicto en la región. Sugiero que com - plementar el despojo con otras herramientas conceptuales, como la posesión, podría llevar a una comprensión más profunda de la cuestión de la tierra en una región como Urabá y a la construcción de soluciones políticas más duraderas.

  4. Primer registro de Dasypsyllus (Avesopsylla lasius lasius (Siphonaptera: Ceratophyllidae en nidos de golondrina chilena, Tachycineta meyeni (Passeriformes: Hirundinidae, en Ushuaia (Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Rosana ARAMBURÚ

    2009-01-01

    Full Text Available La golondrina chilena, Tachycineta meyeni (Cabanis, nidifica en el centro de Chile y suroeste de Argentina. En invierno migra a Bolivia, Paraguay y al sureste de Brasil. Estas golondrinas ocuparon una serie de cajas-nido en Ushuaia, Tierra del Fuego. Luego de la temporada de cría, tratamos los nidos con acetato de etilo y los revisamos en búsqueda de artrópodos hematófagos. Encontramos pulgas adultas, que fueron fijadas, aclaradas, deshidratadas, diafanizadas y montadas en un derivado de clavo de olor para su observación al microsocopio óptico. Identificamos machos y hembras de Dasypsyllus (Avesopsylla lasius lasius (Rothschild. En Argentina, esta pulga es conocida solamente en Sierra de la Ventana (Buenos Aires, donde se la halló parasitando la golondrina barranquera, Notiochelidon cyanoleuca patagonica (Vieillot. La información disponible debería complementarse con prospecciones en localidades intermedias. Otras aves relacionadas con ambas golondrinas por la ocupación de nidos, como el rayadito (Aphrastura spinicauda (Gmelin, ratona común (Troglodytes aedon Vieillot, caminera común (Geositta cunicularia (Vieillot, hornero (Furnarius rufus (Gmelin, podrían contribuir a la dispersión de la pulga entre las dos localidades registradas.

  5. Caminos e historias de la tierra cafetera – La unión entre territorio, paisaje cultural y su gente como producto experiencial de turismo cultural

    Directory of Open Access Journals (Sweden)

    Urte Duis

    2011-11-01

    Full Text Available Las últimas décadas han sido caracterizadas por planteamientos relativos al estudio y puesta en valor del territorio como atractivo turístico, teniendo en cuenta sus recursos, sus habitantes y los procesos de planificación y gestión. En este marco toma fuerza la apreciación de recursos culturales y naturales, el turismo y el paisaje cultural. Este último es el contenedor y el contenido de actividades turísticas que valoran los recursos autóctonos llevando a la creación de una experiencia vivencial como nueva apuesta en el turismo rural. Este artículo presenta las experiencias particulares del Quindío en torno al proyecto Paisaje Cultural y sus implicaciones para el diseño de un modelo de turismo cultural en los pueblos de la Cordillera, basado en los atributos que determinan su excepcionalidad y autenticidad. Para tal fin, se realizaron trabajos participativos dirigidos a la interpretación cultural, conceptualizando el producto “Caminos e historias de la tierra cafetera” y aportando a la ‘patrimonialización’ del paisaje como territorio museo.

  6. Los judíos de Peñafiel : una minoría confesional en tierras de señorío

    Directory of Open Access Journals (Sweden)

    Efrén de la Peña Barroso

    2009-01-01

    Full Text Available La comunidad judía de Peñafiel se configuró como una aljama de pequeño tamaño dentro de la provincia de Valladolid. Los préstamos y las deudas, el arrendamiento de rentas y la actividad inquisitorial reflejan que la evolución de esta comunidad no se diferenció de la del resto de juderías y aljamas castellanas, a pesar de estar ubicada en tierras de señorío. Sin embargo, es interesante destacar que algunos de sus miembros gozaron de una posición acomodada en materia económica, y que varios judíos de Peñafiel controlaron buena parte de los molinos de grano de la ribera del Duratón.The Jewish community of Peñafiel grew as a small Jewry in the province of Valladolid. Loans and debts, taxes, and Inquisition inquiries reveal that the evolution of this community does not differ from other Castilian Jewries although they were inside lordship lands. Furthermore, it has to be highlighted that some of the Jews of the Jewry had considerable wealth, and even owned most of the watermills on the banks of the Duratón river.

  7. Características tecnológicas de la madera de palo morado (Peltogyne mexicana Martínez de tierra colorada, Guerrero, México

    Directory of Open Access Journals (Sweden)

    J. Navarro-Martínez

    2005-01-01

    Full Text Available El presente trabajo contribuye al conocimiento de las características y propiedades tecnológicas de la madera de Palo morado (Peltogyne mexicana Martínez, mediante la caracterización anatómica, porcentaje de elementos y determinación de las propiedades físicas y tres mecánicas. Se colectaron dos árboles en Tierra Colorada Guerrero. El material se obtuvo de trozas a 1.30 m de altura. Para el estudio macroscópico se usaron muestras de 7 x 15 x 1 cm y para el microscópico se elaboraron preparaciones fijas de cortes y de material disociado. La madera presenta un color violeta intenso, porosidad difusa, parénquima en bandas y aliforme confluente con cristales, los elementos de vaso son cortos de diámetro medio, con inclusiones, rayos uniseriados, biseriados, triseriados y raramente multiseriados; las fibras son de tipo libriforme de longitud media, diámetro fino y pared gruesa, presenta densidad básica, contracciones y dureza alta.

  8. Life on earth: to reduce egotism and increase cooperaation La vida en la tierra: mermarl al egoísmo y aumentar la cooperación

    Directory of Open Access Journals (Sweden)

    Jorge Eliécer Ossa Londoño

    2002-04-01

    Full Text Available This short essay collects the thoughts of the author stimulated by some preliminary readings on the sujet of environmental ethics. The concept of life on earth is proposed as the fundamental basis for an ethics of the inviromental. Egotism as an ontogenetc principle for the construction of the individuality of the living being: and cooperation, as a necessary organizing axis, are recognized in this context and it is proposed that a rule of thumb to manage the very complex relatinships with the environment could lay on the capacity of the human being to increase cooperation and reduce his egotism. Este corto ensayo recoge las reflexiones del autor, estimuladas por algunas lecturas preliminares sobre el tema de ética ambiental. Se propone el concepto de la vida en la tierra como base fundamental de una ética planetaria y se rescata el egoísmo ontogénico como una función necesaria para la construcción del individuo vivo y la cooperación como principio organizador necesario. Se sugiere que la capacidad del ser humano para incrementar su sentido de cooperación y para reducir su egoísmo, podrá ser la regla de oro para manejar las complejas relaciones con el entorno.

  9. Las ciencias de la tierra y la biblia. Una aproximación desde la razón científica

    Directory of Open Access Journals (Sweden)

    Francisco J. Ayala

    2004-01-01

    Full Text Available El desarrollo de la Ciencia, Natural e Histórica, ha ido aportando nuevos elementos que permiten una aproximación a los relatos bíblicos desde la perspectiva de la razón científica. En este sentido, se presenta una aproximación científica, básicamente desde las Ciencias de la Tierra y teniendo en cuenta la realidad histórica del pueblo hebreo y la propia Biblia, al relato de la Creación, y los posibles núcleos histórico-científicos de los relatos del Diluvio Universal y la destrucción de Sodoma y Gomorra, de acuerdo con los últimos conocimientos disponibles. Por otra parte, se analizan los condicionamientos que los relatos bíblicos, especialmente la Creación y el Diluvio, impusieron históricamente al surgimiento de las Ciencias Geológicas.

  10. Rendimiento y coste energético en la construcción de cerramientos de fábrica de adobe y bloque de tierra comprimida

    Directory of Open Access Journals (Sweden)

    Rivera Gómez, David

    2001-06-01

    Full Text Available This study synthetically sets forth the results of a research financed as a Special Action by the R+D National Plan; said research had as a main objective the scientific test of the advantages of building with earth in its improved present applications, starting from the sustainable bioclimatic qualities which were already traditionally known. The research process was divided between the constructive analysis of the traditional homes of the North-east Area of Segovia and the proofs obtained in laboratory at the Eduardo Torroja Institute, the School of Architecture of Madrid and the facilities of the Traditional Architecture Research Center (CIAT in Boceguillas (Segovia.Este artículo expone sintéticamente los resultados de una investigación financiada como Acción Especial por el Plan Nacional de I+D; dicha investigación tenía como objeto la demostración científica de las ventajas de la construcción con tierra en sus aplicaciones actuales mejoradas, partiendo de las cualidades bioclimáticas y sostenibles que ya eran conocidas tradicionalmente. El proceso investigador se repartió entre el análisis constructivo de las viviendas tradicionales de la Comarca Nordeste de Segovia y las pruebas de laboratorio en el Instituto Eduardo Torroja, la Escuela de Arquitectura de Madrid, y las instalaciones del Centro de Investigación de Arquitectura Tradicional (C.I.A.T., en Boceguillas (Segovia.

  11. Teorías de la tierra y sistemas geológicos: un largo debate en la historia de la geología

    Directory of Open Access Journals (Sweden)

    Pelayo, Francisco

    1996-12-01

    Full Text Available During the second half of the XVIIIth century, the first theories about the origin and history of the Earth were issued. The interpretation that considered Deluge as a decisive factor in the modeling of land surface was the most debated until the issue of the Catastrophism and Actualism geological systems in the XIXth century. Norwadays, the polemics about methods and systems in the History of Geology is still open between geologists and historians of science.

    Durante la segunda mitad del siglo XVIII se emitieron las primeras teorías del origen e historia de la Tierra. La interpretación que consideraba al Diluvio como el factor geológico decisivo en el modelado de la superficie terrestre fue la más debatida hasta el surgimiento de los sistemas geológicos catastrofista y actualista en el siglo XIX. En la actualidad, continua abierta la polémica entre geólogos e historiadores de la ciencia sobre métodos y sistemas en la Historia de la Geología.

  12. Southern Universities Nuclear Institute

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Southern Universities Nuclear Institute was created in 1961 to provide postgraduate research and teaching facilities for the universities of Cape Town and Stellenbosch. The main research tool is the 6,0 MV Van de Graaff accelerator installed in 1964. Developments and improvements over the years have maintained the Institute's research effectiveness. The work of local research groups has led to a large number of M Sc and doctorate degrees and numerous publications in international journals. Research at the Institute includes front-line studies of basic nuclear and atomic physics, the development and application of nuclear analytical techniques and the application of radioisotope tracers to problems in science, industry and medicine. The Institute receives financial support from the two southern universities, the Department of National Education, the CSIR and the Atomic Energy Board

  13. Even at the uttermost ends of the Earth: how seabirds telecouple the Beagle Channel with regional and global processes that affect environmental conservation and social-ecological sustainability

    Directory of Open Access Journals (Sweden)

    Andrea N. Raya Rey

    2017-12-01

    Full Text Available Human-wildlife dynamics exhibit novel characteristics in the Anthropocene, given the unprecedented degree of globalization that has increased the linkages between habitats and people across space and time. This is largely caused by transnational mobility and migration, international labor, resource markets, and trade. Understanding the relationship between humans and wildlife, and their associated telecoupling processes, helps to promote better management practices and governance for reconciling socioeconomic and conservation interests. Even remote places on the globe exhibit these features. For example, in southern Patagonia's coastal and marine ecosystems, seabirds are not only very abundant and charismatic members of the wildlife community, nowadays, their colonies are a main tourism attraction of global significance, and in the past they were used for consumptive and scientific purposes that also linked the "uttermost ends of the Earth" with distant places. Thus, in this study, we review human-seabird interactions in the iconic Beagle Channel (BC in the Argentine portion of the Tierra del Fuego Archipelago. We adapted and employed the coupled human and natural systems (CHANS approach and telecoupling framework to integrate disparate social and biological information and obtain a more holistic understanding of current human-seabird dynamics and trends in the BC. Although our assessment includes the temporal scale of human-seabird relationships, we centered the CHANS and telecoupling analysis on the modern seabird-tourism interaction, focused on the channel's Argentine sector, in which tourism is most intensively developed. Our synthesis of the BC's telecoupled CHANS allowed us to recognize the strong historical local-to-global interactions between both human and natural subsystems and the sharp increase in distance telecoupling during the 20th century. Despite this globalizing trend in seabirds connecting the BC's local ecosystems to distant

  14. Cryogenic microwave channelized receiver

    International Nuclear Information System (INIS)

    Rauscher, C.; Pond, J.M.; Tait, G.B.

    1996-01-01

    The channelized receiver being presented demonstrates the use of high temperature superconductor technology in a microwave system setting where superconductor, microwave-monolithic-integrated-circuit, and hybrid-integrated-circuit components are united in one package and cooled to liquid-nitrogen temperatures. The receiver consists of a superconducting X-band four-channel demultiplexer with 100-MHz-wide channels, four commercial monolithically integrated mixers, and four custom-designed hybrid-circuit detectors containing heterostructure ramp diodes. The composite receiver unit has been integrated into the payload of the second-phase NRL high temperature superconductor space experiment (HTSSE-II). Prior to payload assembly, the response characteristics of the receiver were measured as functions of frequency, temperature, and drive levels. The article describes the circuitry, discusses the key issues related to design and implementation, and summarizes the experimental results

  15. Chaos in quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Hosur, Pavan; Qi, Xiao-Liang [Department of Physics, Stanford University,476 Lomita Mall, Stanford, California 94305 (United States); Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, Massachusetts 02139 (United States); Yoshida, Beni [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena CA 91125 (United States)

    2016-02-01

    We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.

  16. Distribution Channels Conflict and Management

    OpenAIRE

    Kiran, Dr Vasanth; Majumdar, Dr Mousumi; Kishore, Dr Krishna

    2012-01-01

    Relationships in distribution channels tend to be long-term oriented and members of the channel rely on each other to jointly realize their goals by serving buyers. Despite the channels focus on serving buyers, conflicts often arise between channel members because of each members self-interest. When conflicts arise, the perceptions of a channel member based on normative, rational/instrumental, or emotional reasoning will influence relational norms like trust and commitment that characterize t...

  17. Southern Alberta system reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, A. [Alberta Electric System Operator, Calgary, AB (Canada)

    2008-07-01

    System planning for the Alberta Electric System Operator's (AESO) southern system was discussed in view of the growing interest in developing wind energy resources in the province. While Alberta currently has a total of 11,500 MW of installed wind power, southern Alberta has a very small capability for interconnecting additional wind resources. There are 3 main agencies involved in system planning for the southern region: (1) the Alberta Utilities Commission (AUC), (2) the AESO, and (3) the transmission facility owners. Transmission needs are studied by the AESO, who then applies to the AUC for approval. Transmission facility owners also apply to the AUC for approval to construct facilities. The AESO's roles are to operate the wholesale electricity market; plan the transmission system; arrange access for loads and generation; and oversee transmission system operation. The AESO is an independent agency with a public interest mandate. The AESO's queue management process has been designed to facilitate non-discriminatory system access. Development options currently being considered by the AESO include a 240 kV AC transmission line; a 500 kV AC transmission line; a 765 kV AC transmission line; a high voltage direct current (HVDC) system; and a voltage source converter (VSC) HVDC system. Radial and looped configurations are also being considered. The AESO is currently conducting a participant involvement program that involves open houses with the Canadian Wind Energy Association (CanWEA) and other provincial stakeholders. tabs., figs.

  18. Morphological expression of active tectonics in the Southern Alps

    Science.gov (United States)

    Robl, Jörg; Heberer, Bianca; Neubauer, Franz; Hergarten, Stefan

    2015-04-01

    Evolving drainage pattern and corresponding metrics of the channels (e.g. normalized steepness index) are sensitive indicators for tectonic or climatic events punctuating the evolution of mountain belts and their associated foreland basins. The analysis of drainage systems and their characteristic properties represents a well-established approach to constrain the impact of tectonic and climatic drivers on mountainous landscapes in the recent past. The Southern Alps (SA) are one of the seismically most active zones in the periphery of northern Adria. Recent deformation is caused by the ongoing convergence of the Adriatic and European plate and is recorded by numerous earthquakes in the domain of the SA. Deformation in the SA is characterized by back-thrusting causing crustal thickening and should therefore result in uplift and topography formation. The vertical velocity field determined by GPS-data clearly indicates a belt of significant uplift in the south South alpine indenter between Lake Garda in the west and the Triglav in the east and strong subsidence of the foreland basin surrounding the Mediterranean Sea near Venice, although subsidence is often related to ongoing subduction of the Adriatic microplate underneath Appennines. Despite of these short term time series, timing, rates and drivers of alpine landscape evolution are not well constrained and the linkage between crustal deformation and topographic evolution of this highly active alpine segment remains unclear for the following reasons: (1) The eastern Southern Alps were heavily overprinted by the Pleistocene glaciations and tectonic signals in the alpine landscape are blurred. Only the transition zone to the southern foreland basin remained unaffected and allows an analysis of a glacially undisturbed topography. (2) The major part of this domain is covered by lithology (carbonatic rocks) which is unsuitable for low temperature geochronology and cosmogenic isotope dating so that exhumation and erosion

  19. Fuel channel refilling

    International Nuclear Information System (INIS)

    Shoukri, M.; Abdul-Razzak, A.

    1992-11-01

    This report extends the work reported in document INFO-0370 on fuel channel refilling by providing analysis of the refilling tests conducted using the RD-14 and RD-14M test facilities. The analysis focuses on the general thermal-hydraulic characteristics of the facilities following various small and large inlet and outlet header breaks with emergency coolant injection. The two-fluid model thermal-hydraulic computer code CATHENA was tested against results obtained from selected experiments carried out in the two facilities. Conclusions related to the effect of break size, mode of emergency core injection, primary pump operation and parallel channels are presented. (Author) (116 figs., 17 tabs., 53 refs.)

  20. Ion channels in glioblastoma.

    Science.gov (United States)

    Molenaar, Remco J

    2011-01-01

    Glioblastoma is the most common primary brain tumor with the most dismal prognosis. It is characterized by extensive invasion, migration, and angiogenesis. Median survival is only 15 months due to this behavior, rendering focal surgical resection ineffective and adequate radiotherapy impossible. At this moment, several ion channels have been implicated in glioblastoma proliferation, migration, and invasion. This paper summarizes studies on potassium, sodium, chloride, and calcium channels of glioblastoma. It provides an up-to-date overview of the literature that could ultimately lead to new therapeutic targets.

  1. Fuel channel refilling

    International Nuclear Information System (INIS)

    Shoukri, M.; Abdul-Razzak, A.

    1990-04-01

    Analysis of existing data on fuel channel refilling is presented. The analysis focuses on the data obtained using the Stern Laboratories Cold Water Injection Test (CWIT) Facility. The two-fluid model thermal-hydraulics computer code CATHENA is also used to simulate experimental results on fuel channel refilling from both the CWIT and RD-14 facilities. Conclusions related to single and double break tests, including the effect of non-condensible gases, are presented. A set of recommendations is given for further analysis and separate effect experiments. (67 figs., 5 tabs., 24 refs.)

  2. Potassium channels in brain mitochondria.

    Science.gov (United States)

    Bednarczyk, Piotr

    2009-01-01

    Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

  3. A search for Potential Impact Sites in Southern Argentina

    Science.gov (United States)

    Rocca, M. C. L.

    The Southern part of Argentina is composed of five Provinces; Tierra del Fuego, Santa Cruz, Chubut, Rio Negro and Neuquen. A search for potential impact sites was performed by the author through the examination of 76 color LANDSAT satellite images ( 1:250,000 - resolution = 250 meters ) at the Instituto Geografico Militar ( IGM ) of Buenos Aires city. When a potential candidate was found a more detailed study of the site was done. If available the radar X-SAR satellite images of the Deutsche Forschungsanstalt fur Luft-und Raumfahrt, (DLR), Berlin, Germany , were also examined. The final step was to perform a review of the available published geologic information of each site at the Servicio Geologico y Minero Argentino ( SEGEMAR ), ( =Geological Survey of Argentina ), in Buenos Aires. The resulting catalogue contains information about sites where possible simple crater or complex impact structures could be present. Each case demands future detailed and `in situ' research by an impact cratering specialist. --Tierra del Fuego: TF1 ) Ushuaia 5569-II, No 218. Cerro Taarsh, Estancia San Justo. Possible complex structure. Semi-circular area of concentric low ridges. Estimated diameter : 12 km. Probably very eroded. --Santa Cruz: SC1 ) Gobernador Gregores 4969-I, No 127. Estancia La Aragonesa Possible eroded complex structure. Circular area of low ridges, estimated diameter: 10 km.. Bull's eye like morphology. SC2 ) Gobernador Gregores 4969-I, No 127. Gran Altiplanicie Central. Possible simple crater in basalts. Diameter: 1 km.. SC3 ) Tres Lagos 4972-IV, No 106. Meseta del Bagual Chico. Possible perfectly circular simple crater in basalts. Diameter: 1.0 km.. SC4 )Paso Rio Bote 5172-II, No 20. Rio Pelque, Ruta Provincial No 5. A circular bowl-shaped structure is present on fluvial deposits of pleistocenic age. Diameter: 3.5 km.. SC5 ) Caleta Olivia 4769-II, No 28. North of Cerro Doce Grande. Possible complex structure of concentric circular rings of ridges. SC6 ) Caleta

  4. MITOCHONDRIAL BKCa CHANNEL

    Directory of Open Access Journals (Sweden)

    Enrique eBalderas

    2015-03-01

    Full Text Available Since its discovery in a glioma cell line 15 years ago, mitochondrial BKCa channel (mitoBKCa has been studied in brain cells and cardiomyocytes sharing general biophysical properties such as high K+ conductance (~300 pS, voltage-dependency and Ca2+-sensitivity. Main advances in deciphering the molecular composition of mitoBKCa have included establishing that it is encoded by the Kcnma1 gene, that a C-terminal splice insert confers mitoBKCa ability to be targeted to cardiac mitochondria, and evidence for its potential coassembly with β subunits. Notoriously, β1 subunit directly interacts with cytochrome c oxidase and mitoBKCa can be modulated by substrates of the respiratory chain. mitoBKCa channel has a central role in protecting the heart from ischemia, where pharmacological activation of the channel impacts the generation of reactive oxygen species and mitochondrial Ca2+ preventing cell death likely by impeding uncontrolled opening of the mitochondrial transition pore. Supporting this view, inhibition of mitoBKCa with Iberiotoxin, enhances cytochrome c release from glioma mitochondria. Many tantalizing questions remain. Some of them are: how is mitoBKCa coupled to the respiratory chain? Does mitoBKCa play non-conduction roles in mitochondria physiology? Which are the functional partners of mitoBKCa? What are the roles of mitoBKCa in other cell types? Answers to these questions are essential to define the impact of mitoBKCa channel in mitochondria biology and disease.

  5. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  6. Workshop on Gas Channels

    Science.gov (United States)

    2013-02-07

    Effect of pressure on gas permeability. In Fish … Different channels or splice variants at different depth.  HRE (hypoxia-response elements): which...proteins unexpectedly have HREs . HIF-1.  Shear stress:  expression of NOS  Are different splice variants used under different conditions?  Size

  7. Unexpected Climatological Behavior of MLT Gravity Wave Momentum Flux in the Lee of the Southern Andes Hot Spot

    Science.gov (United States)

    DeWit, R. J.; Janches, D.; Fritts, D. C.; Stockwell, R. G.; Coy, L.

    2017-01-01

    The Southern Argentina Agile MEteor Radar (SAAMER), located at Tierra del Fuego (53.7degS, 67.7degW), has been providing near-continuous high-resolution measurements of winds and high-frequency gravity wave (GW) momentum fluxes of the mesopause region since May 2008. As SAAMER is located in the lee of the largest seasonal GW hot spot on Earth, this is a key location to study GWs and their interaction with large-scale motions. GW momentum flux climatologies are shown for the first time for this location and discussed in light of these unique dynamics. Particularly, the large eastward GW momentum fluxes during local winter are surprising, as these observations cannot be explained by the direct upward propagation of expected large-amplitude mountain waves (MWs) through the eastward stratospheric jet. Instead, these results are interpreted as secondary GWs propagating away from stratospheric sources over the Andes accompanying MW breaking over the Southern Andes.

  8. The Southern Ocean Observing System

    OpenAIRE

    Rintoul, Stephen R.; Meredith, Michael P.; Schofield, Oscar; Newman, Louise

    2012-01-01

    The Southern Ocean includes the only latitude band where the ocean circles the earth unobstructed by continental boundaries. This accident of geography has profound consequences for global ocean circulation, biogeochemical cycles, and climate. The Southern Ocean connects the ocean basins and links the shallow and deep limbs of the overturning circulation (Rintoul et al., 2001). The ocean's capacity to moderate the pace of climate change is therefore influenced strongly by the Southern Ocean's...

  9. Anthropocene Survival of Southern New England's Salt ...

    Science.gov (United States)

    In southern New England, salt marshes are exceptionally vulnerable to the impacts of accelerated sea level rise. Regional rates of sea level rise have been as much as 50 % greater than the global average over past decades, a more than fourfold increase over late Holocene background values. In addition, coastal development blocks many potential marsh migration routes, and compensatory mechanisms relying on positive feedbacks between inundation and sediment deposition are insufficient to counter inundation increases in extreme low-turbidity tidal waters. Accordingly, multiple lines of evidence suggest that marsh submergence is occurring in southern New England. A combination of monitoring data, field re-surveys, radiometric dating, and analysis of peat composition have established that, beginning in the early and mid-twentieth century, the dominant low-marsh plant, Spartina alterniflora, has encroached upward in tidal marshes, and typical high-marsh plants, including Juncus gerardii and Spartina patens, have declined, providing strong evidence that vegetation changes are being driven, at least in part, by higher water levels. Additionally, aerial and satellite imagery show shoreline retreat, widening and headward extension of channels, and new and expanded interior depressions. Papers in this special section highlight changes in marsh-building processes, patterns of vegetation loss, and shifts in species composition. The final papers turn to strategies for minimiz

  10. Transferring Knowledge Gained From a Field Experience in Tierra del Fuego, the Uttermost Part of the Earth, to Central Texas Science Classrooms

    Science.gov (United States)

    Ormiston, C.; Dovzak, N.; Anderson, S.; Perry, E.; Ellins, K.; Tingle, D.; Knettel, P.; Redding, S.; Odle, K.

    2005-12-01

    As part of the UTIG's Teachers in the Field program, we, three teachers from Boerne High School in south-central Texas, and four of our students, collaborated with an international team of geoscientists studying the tectonic and climatic evolution of the Lago Fagnano region in Tierra del Fuego, Argentina, in March 2005. This unique field experience allowed us to participate in all aspects of the scientific process: the consideration of research questions, development of a research plan, collection of field data and observations, and synthesis and presentation of results. In addition to field work and reconnaissance tied directly to the project objectives, we characterized the modern chemical/physical soil and water parameters (temperature, pH, dissolved oxygen, NH4 content, etc.) and isotopic (18O and D) composition of the Lago Fagnano watershed. These data are now integrated into an existing database of comparable chemical/physical information gathered for North American sites through our summer field courses. We will utilize this rich data set to make Texas-Tierra del Fuego ecosystem comparisons with our classes. The level of mentoring, preparation and follow-up provided by an NSF GK-12 Fellow was a key factor contributing to the success of our experience and an important element in helping us transfer components of this challenging experience to our students. Before, during, and following a two-week field season at Lago Fagnano, we and our students were actively engaged as learners and as scientists. We acquired concepts and skills that are readily applicable in a classroom setting: geologic mapping, GIS applications, isotopic data collection and analysis, tectonics concepts, and a general understanding of how science is truly conducted. Other factors that contributed to a positive experience included the team of dynamic scientists, who encouraged, helped and inspired us, the strong support that we received from our high school campus and district level

  11. Justicia de género y tierras en Colombia: Desafíos para la era del ‘pos-acuerdo’

    Directory of Open Access Journals (Sweden)

    Donny Meertens

    2016-10-01

    Full Text Available Gender and Land Justice in Colombia: Challenges for the Post-Peace Accords Era With the signature of a Peace Accord between FARC guerrilla and the Colombian Government in August 2016, the country confronts a great number of challenges in terms of the implementation, not only of the immediate actions needed to carry out the DDR process for ex-combatants and the truth, justice and reparations measures for the victims, but also of the long-term democratic transformations agreed upon at the negotiations table. In this exploration I will reflect on the scope of land restitution as a measure of reparations, and its transformative potential in terms of gender justice. Colombia is the first country in Latin America in which these two elements, land and gender, have been explicitly included in the peace process. One of the conclusions of this reflection is that more institutional support is needed for rural women’s organizations in order to consolidate the results of a gender-just land restitution and link these to the rural reforms of the peace agenda, as a contribution to a more democratic participation of men and women in post-conflict rural development. Resumen Con la firma del Acuerdo de Paz entre FARC guerrilla y el Gobierno de Colombia, en agosto de 2016, el país enfrenta un sinnúmero de desafíos para la implementación de lo pactado, no sólo en lo inmediato (desarme-desmovilización-reintegración de excombatientes y de justicia-verdad-reparación para las víctimas sino frente a las transformaciones democráticas estipuladas para el pos-conflicto. En esta exploración reflexiono sobre la restitución de tierras como medida de reparación a víctimas y su alcance transformativo en términos de justicia de género. Colombia es el primer país en América Latina en el cual estos dos elementos, tierras y género, han sido incorporados explícitamente en un proceso de paz. Una de las conclusiones de esta reflexión es que se requiere un

  12. Análisis de nuevos estándares para reducir datos de gravedad: aplicación en Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pedraza De Marchi

    2011-12-01

    Full Text Available El objetivo principal de este trabajo consistió en investigar el uso de nuevos estándares y procedimientos para reducir datos de gravedad con el fin de mejorar la precisión, exactitud y utilidad geofísica de las anomalías de gravedad. Los nuevos estándares tienen en cuenta el mayor poder computacional actual, la moderna tecnología de posicionamiento satelital para determinar la altura y el posicionamiento de las estaciones gravimétricas, las mejoras en las bases de datos topográficos/batimétricos y nuevos algoritmos matemáticos. Están basados en procedimientos, protocolos, ecuaciones y parámetros internacionalmente aceptados y que en muchos casos difieren de los presentados en los actuales libros de textos y bases de datos gravimétricos existentes. El cambio más importante que sugieren los nuevos estándares es el uso del elipsoide de referencia terrestre internacionalmente adoptado para definir el datum vertical o superficie de referencia para las alturas (Hinze et al., 2005, debido al creciente uso del Sistema Global de Posicionamiento (GPS para realizar trabajos de campo gravimétricos. Las anomalías calculadas con los nuevos estándares podrían ser modificadas por el adjetivo "elipsoidal" (Hinze et al., 2005 para diferenciarlas de las anomalías que se calculan mediante las elevaciones convencionales referidas al geoide. Se usó la información existente en la provincia de Tierra del Fuego para hacer reducciones, siguiendo los procedimientos tradicionales y las nuevas recomendaciones y estándares. Se utilizaron los modelos digitales de terreno y modelos geopotenciales a fin de evaluar la eficacia de su uso en las reducciones gravimétricas. Se integró la información gravimétrica terrestre con anomalías de aire libre derivadas de la altimetría satelital en el mar, en un mapa combinado de anomalías isostáticas elipsoidales.The main objective of this study was to investigate the use of new standards and procedures for

  13. Dinámica de nutrientes en plantaciones forestales de Azadirachta indica (Meliaceae establecidas para restauración de tierras degradadas en Colombia

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Flórez-Flórez

    2013-06-01

    Full Text Available Azadirachta indica A. Juss (Nim ha sido ampliamente empleada en procedimientos de restauración, por lo tanto se evaluó el potencial de sus plantaciones para restaurar tierras secas degradadas por sobrepastoreo, vía reactivación del ciclo biogeoquímico. En 20 parcelas de 250m², se instalaron trampas de hojarasca y litter-bags. Se tomaron muestras de hojas maduras y de suelos dentro y fuera de las plantaciones, y se determinaron sus contenidos elementales. Fueron monitoreados la caída de hojarasca, la descomposición de hojarasca y la reabsorción de nutrientes foliares durante un año. Los aportes anuales de hojarasca fina representaron 557.54kg/ha (33% hojas de Nim. Los mayores retornos potenciales de nutrientes vía foliar fue- ron de Ca (4.6kg/ha y N (2.4kg/ha y los menores de P (0.06kg/ha. El 68% del material se descompuso tras un año. La mayor liberación de nutrientes fue de K (100% y la menor de N (40%. El P fue el nutriente más limitante, con baja disponibilidad edáfica y alta eficiencia en su uso según el Índice de Vitousek (IEV=3 176 y la reabsorción foliar (35%. Estas plantaciones juveniles demostraron efectividad en la reactivación del ciclo biogeoquímico, que mejoraron parámetros edáficos, según incrementos de materia orgánica, P y K; 72%, 31% y 61%, respectiva- mente. Además mejoraron la estabilidad de agregados y las tasas de respiración microbiana.

  14. DISEÑO ESTADÍSTICO PARA LA REMOCIÓN DE ROJO BÁSICO 46 UTILIZANDO TIERRA FULLER REGENERADA COMO MATERIAL ALTERNATIVO

    Directory of Open Access Journals (Sweden)

    Benjamín Zuluaga Díaz

    Full Text Available Diferentes materiales no convencionales han sido evaluados en los últimos años como adsorbentes para el tratamiento de efluentes coloreados provenientes de la industria textil. La tierra fuller (TF compuesta por distintos minerales, ha presentado una alta capacidad para la remoción de diferentes colorantes catiónicos, no obstante el rojo básico 46 (RB46, ampliamente utilizando en los procesos de tinción no ha sido estudiado sobre este material. En esta investigación se evalúan las mejores condiciones para alcanzar la mayor remoción del RB46 sobre TF mediante un diseño estadístico de experimentos bajo sistema discontinuo. Las variables analizadas fueron dosis de adsorbente, concentración de colorante y tiempo de contacto. La concentración final del colorante se cuantificó por espectrofotometría UV-Vis. Un diseño factorial 2³ y su posterior optimización a través de un diseño de superficie de respuesta central compuesta permitió alcanzar una remoción máxima del 99,07 % a una concentración de 35,0 mgL-1, una dosificación de 1,1 gL-1 y un tiempo de contacto de 8 h con un coeficiente de correlación ajustado del 96,79 %.

  15. Cambios en el uso del suelo de las tierras del ingenio Las Palmas, provincia de Chaco, en los años 1987 y 2001

    Directory of Open Access Journals (Sweden)

    Febe Rozkiewicz

    2010-01-01

    Full Text Available En el departamento Bermejo, provincia de Chaco, a fines del siglo XIX se origina uno de los ingenios azucareros más importantes del país: Las Palmas del Chaco Austral S.A. En la década de los noventa es víctima de las políticas de privatización imperantes del momento. Como consecuencia, se produce su cierre y posterior desaparición, lo que supuso la eliminación de la principal fuente de trabajo de la localidad. Las tendencias actuales y novedosas en teledetección, cartografía digital y Sistemas de Información Geográfica (SIG son una forma útil e importante de ofrecer conocimientos actualizados para el diagnóstico, monitoreo y su aplicación en la gestión e investigación de recursos presentes en los distintos lugares de nuestro país. En el presente trabajo se pretende analizar los cambios producidos en el uso de suelo en las tierras del ex Ingenio a partir del cierre del mismo, mediante el uso de imágenes satelitales de los años 1987 y 2001, y de sistemas de información geográfica (SIG. El análisis multiespectral y multitemporal de las mismas permitirá discriminar los tipos de cobertura del suelo sobre la base de su respuesta espectral.

  16. Southern Pine Beetle Information System (SPBIS)

    Science.gov (United States)

    Valli Peacher

    2011-01-01

    The southern pine beetle (SPB) is the most destructive forest insect in the South. The SPB attacks all species of southern pine, but loblolly and shortleaf are most susceptible. The Southern Pine Beetle Information System (SPBIS) is the computerized database used by the national forests in the Southern Region for tracking individual southern pine beetle infestations....

  17. Quantum communication under channel uncertainty

    International Nuclear Information System (INIS)

    Noetzel, Janis Christian Gregor

    2012-01-01

    This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

  18. VAX CAMAC channel

    International Nuclear Information System (INIS)

    Nelson, D.J.; Breidenbach, M.; Granieri, C.D.; Grund, J.E.; Patrick, J.F.; Weaver, L.J.

    1980-10-01

    A new generation CAMAC System has been developed for the Mark II Detector at SLAC's PEP storage ring. This flexible system can efficiently transfer data between a host computer and a very large set of CAMAC data acquisition and control modules. A bipolar microprocessor operates as a Channel interface by supervising the CAMAC system and minimizing the host computer's work. This programmable channel couples the host to a set of System Crates; each System Crate houses Branch Drivers that can directly control a set of crates or communicate over differential parallel highways to Branch Receivers for control of distant crates. A coherent software package integrates the high level programs, system driver level programs, and microcode control of the system

  19. Geysering in boiling channels

    Energy Technology Data Exchange (ETDEWEB)

    Aritomi, Masanori; Takemoto, Takatoshi [Tokyo Institute of Technology, Tokyo (Japan); Chiang, Jing-Hsien [Japan NUS Corp. Ltd., Toyko (Japan)] [and others

    1995-09-01

    A concept of natural circulation BWRs such as the SBWR has been proposed and seems to be promising in that the primary cooling system can be simplified. The authors have been investigating thermo-hydraulic instabilities which may appear during the start-up in natural circulation BWRs. In our previous works, geysering was investigated in parallel boiling channels for both natural and forced circulations, and its driving mechanism and the effect of system pressure on geysering occurrence were made clear. In this paper, geysering is investigated in a vertical column and a U-shaped vertical column heated in the lower parts. It is clarified from the results that the occurrence mechanism of geysering and the dependence of system pressure on geysering occurrence coincide between parallel boiling channels in circulation systems and vertical columns in non-circulation systems.

  20. Coolant channel module CCM

    International Nuclear Information System (INIS)

    Hoeld, Alois

    2007-01-01

    A complete and detailed description of the theoretical background of an '(1D) thermal-hydraulic drift-flux based mixture-fluid' coolant channel model and its resulting module CCM will be presented. The objective of this module is to simulate as universally as possible the steady state and transient behaviour of the key characteristic parameters of a single- or two-phase fluid flowing within any type of heated or non-heated coolant channel. Due to the possibility that different flow regimes can appear along any channel, such a 'basic (BC)' 1D channel is assumed to be subdivided into a number of corresponding sub-channels (SC-s). Each SC can belong to only two types of flow regime, an SC with just a single-phase fluid, containing exclusively either sub-cooled water or superheated steam, or an SC with a two-phase mixture flow. After an appropriate nodalisation of such a BC (and therefore also its SC-s) a 'modified finite volume method' has been applied for the spatial discretisation of the partial differential equations (PDE-s) which represent the basic conservation equations of thermal-hydraulics. Special attention had to be given to the possibility of variable SC entrance or outlet positions (which describe boiling boundaries or mixture levels) and thus the fact that an SC can even disappear or be created anew. The procedure yields for each SC type (and thus the entire BC), a set of non-linear ordinary 1st order differential equations (ODE-s). To link the resulting mean nodal with the nodal boundary function values, both of which are present in the discretised differential equations, a special quadratic polygon approximation procedure (PAX) had to be constructed. Together with the very thoroughly tested packages for drift-flux, heat transfer and single- and two-phase friction factors this procedure represents the central part of the here presented 'Separate-Region' approach, a theoretical model which provides the basis to the very effective working code package CCM

  1. Evaluación de tierras para reforestación (Horche, Guadalajara mediante un índice de Productividad Agraria

    Directory of Open Access Journals (Sweden)

    Hontoria Fernández, C.

    2002-03-01

    Full Text Available The EU is promoting afforestation in countries, like Spain, with areas vulnerable to land degradation and desertification. This paper aims to set up, by mean of Land Evaluation, the marginal lands in order to know which ones are susceptible to change from farm to forest. The Land Evaluation method used in this paper is an adaptation and update of the Riquier et al. (1970. It has been named «Índice de Productividad Agraria (IPA», by mean of which is possible to evaluate the main kind of extensive land use: herbaceous winter-spring and herbaceous summer crops, tree crops, range, and forest, all of then on dry and irrigated system, and the herbaceous and tree crops under conventional tillage and no tillage. The study area with an extension of 50 km2 is in Horche (southwest Guadalajara, central Spain. The Land survey has let distinguish nine mapping units: Cerrillo, Bachos, Plataformas, Vertientes, Glacis-Terrazas, Pie de ladera, Abanicos aluviales and Vegas (rainfed and irrigated. The IPA shows the Vertientes and Glacis-Terrazas with tree crops, and the Abanicos Aluviales and Cerrillos with herbaceous crops are marginal agricultural lands and are susceptible to change from farm to forest.

    [es] La Unión Europea está promoviendo la reforestación en aquellos países, como España, con áreas vulnerables a la degradación y a la desertificación. El propósito de este artículo es delimitar y definir, mediante un método de Evaluación de Tierras, las áreas marginales con el fin de conocer cuáles son susceptibles al cambio de uso agrícola al forestal. El método de Evaluación de Tierras que se utiliza en este artículo es una adaptación y actualización del de Riquier et al. (1970. Se ha denominado «índice de Productividad Agraria (IPA», y permite la Evaluación para los tipos de uso extensivos: cultivos herbáceos de invierno-primavera, cultivos herbáceos de verano, cultivos leñosos, pastizal y forestal, todos

  2. Tourism distribution channels

    OpenAIRE

    Camilleri, Mark Anthony

    2017-01-01

    The distribution channels link the customers with the businesses. For many years, the tourism businesses may have distributed their products and services through intermediaries. However, the latest advances in technology have brought significant changes in this regard. More individuals and corporate customers are increasingly benefiting of ubiquitous technologies, including digital media. The development of mobile devices and their applications, are offering a wide range of possibilities to t...

  3. Athermal channeled spectropolarimeter

    Science.gov (United States)

    Jones, Julia Craven

    2015-12-08

    A temperature insensitive (athermal) channeled spectropolarimeter (CSP) is described. The athermal CSP includes a crystal retarder formed of a biaxial crystal. The crystal retarder has three crystal axes, wherein each axis has its own distinct index of refraction. The axes are oriented in a particular manner, causing an amplitude modulating carrier frequency induced by the crystal retarder to be thermally invariant. Accordingly, a calibration beam technique can be used over a relatively wide range of ambient temperatures, with a common calibration data set.

  4. Nuclear reactor coolant channels

    International Nuclear Information System (INIS)

    Macbeth, R.V.

    1978-01-01

    A nuclear reactor coolant channel is described that is suitable for sub-cooled reactors as in pressurised water reactors as well as for bulk boiling, as in boiling water reactors and steam generating nuclear reactors. The arrangement aims to improve heat transfer between the fuel elements and the coolant. Full constructional details are given. See also other similar patents by the author. (U.K.)

  5. The M2 Channel

    DEFF Research Database (Denmark)

    Santner, Paul

    Drug resistance of Influenza A against antivirals is an increasing problem. No effective Influenza A drugs targeting the crucial viral protein, the proton transporter M2 are available anymore due to widespread resistance. Thanks to research efforts elucidating M2 protein structure, function and i...... resistance escape routes from drug inhibition. We thereby were hopefully able to provide a platform for the large-scale evaluation of M2 channel activity, inhibitors and resistance....

  6. Aquaglyceroporins: generalized metalloid channels

    Science.gov (United States)

    Mukhopadhyay, Rita; Bhattacharjee, Hiranmoy; Rosen, Barry P.

    2014-01-01

    Background: Aquaporins (AQPs), members of a superfamily of transmembrane channel proteins, are ubiquitous in all domains of life. They fall into a number of branches that can be functionally categorized into two major sub-groups: i) orthodox aquaporins, which are water-specific channels, and ii) aquaglyceroporins, which allow the transport of water, non-polar solutes, such as urea or glycerol, the reactive oxygen species hydrogen peroxide, and gases such as ammonia, carbon dioxide and nitric oxide and, as described in this review, metalloids. Scope of Review: This review summarizes the key findings that AQP channels conduct bidirectional movement of metalloids into and out of cells. Major Conclusions: As(OH)3 and Sb(OH)3 behave as inorganic molecular mimics of glycerol, a property that allows their passage through AQP channels. Plant AQPs also allow the passage of boron and silicon as their hydroxyacids, boric acid (B(OH)3) and orthosilicic acid (Si(OH)4), respectively. Genetic analysis suggests that germanic acid (GeO2) is also a substrate. While As(III), Sb(III) and Ge(IV) are toxic metalloids, borate (B(III)) and silicate (Si(IV)) are essential elements in higher plants. General Significance: The uptake of environmental metalloids by aquaporins provides an understanding of (i) how toxic elements such as arsenic enter the food chain; (ii) the delivery of arsenic and antimony containing drugs in the treatment of certain forms of leukemia and chemotherapy of diseases caused by pathogenic protozoa; and (iii) the possibility that food plants such as rice could be made safer by genetically modifying them to exclude arsenic while still accumulating boron and silicon. PMID:24291688

  7. Matching Dyadic Distributions to Channels

    OpenAIRE

    Böcherer, Georg; Mathar, Rudolf

    2010-01-01

    Many communication channels with discrete input have non-uniform capacity achieving probability mass functions (PMF). By parsing a stream of independent and equiprobable bits according to a full prefix-free code, a modu-lator can generate dyadic PMFs at the channel input. In this work, we show that for discrete memoryless channels and for memoryless discrete noiseless channels, searching for good dyadic input PMFs is equivalent to minimizing the Kullback-Leibler distance between a dyadic PMF ...

  8. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  9. Microstructural information from channeling measurements

    International Nuclear Information System (INIS)

    Quere, Y.

    1984-09-01

    Channeling is sensitive to nearly all structural changes in solids. One briefly recalls how particles are dechanneled by lattice defects and describes the main applications of channeling to materials science: detection of radiation damage, location of impurity atoms, precipitations in alloys... Channeling being a phenomenon characteristic of perfect crystals, any type of lattice imperfection (phonons, crystal defects, precipitation etc.) is expected to produce dechanneling. Consequently channeling and its opposite, dechanneling, have both been used to study structure and structural changes of materials

  10. Ion channeling revisited

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corona, Aldo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nguyen, Anh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    A MS Excel program has been written that calculates accidental, or unintentional, ion channeling in cubic bcc, fcc and diamond lattice crystals or polycrystalline materials. This becomes an important issue when simulating the creation by energetic neutrons of point displacement damage and extended defects using beams of ions. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different powers of the argument. The program then offers an extremely convenient way to calculate axial and planar half-angles and minimum yield or dechanneling probabilities, effects on half-angles of amorphous overlayers, accidental channeling probabilities for randomly oriented crystals or crystallites, and finally a way to automatically generate stereographic projections of axial and planar channeling half-angles. The program can generate these projections and calculate these probabilities for axes and [hkl] planes up to (555).

  11. The alpha channeling effect

    Science.gov (United States)

    Fisch, N. J.

    2015-12-01

    Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled into useful energy, so as to heat fuel ions or to drive current. Such a channeling needs to be catalyzed by waves Waves can produce diffusion in energy of the alpha particles in a way that is strictly coupled to diffusion in space. If these diffusion paths in energy-position space point from high energy in the center to low energy on the periphery, then alpha particles will be cooled while forced to the periphery. The energy from the alpha particles is absorbed by the wave. The amplified wave can then heat ions or drive current. This process or paradigm for extracting alpha particle energy collisionlessly has been called alpha channeling. While the effect is speculative, the upside potential for economical fusion is immense. The paradigm also operates more generally in other contexts of magnetically confined plasma.

  12. Un nuevo mamífero introducido en la Tierra del Fuego: el "peludo" Chaetophractus villosus (Mammalia, Dasypodidae en Isla Grande A new introduced mammal in Tierra del Fuego: the "large hairy armadillo" Chaetophractus villosus (Mammalia, Dasypodidae in the Isla Grande island

    Directory of Open Access Journals (Sweden)

    SEBASTIÁN POLJAK

    2007-09-01

    Full Text Available El 66 % de la mastofauna de la Tierra del Fuego está compuesta por especies introducidas deliberadamente por cuestiones de índole económica, estética y caza deportiva. Entre ellas, el armadillo Chaetophractus villosus conocido vulgarmente como "peludo", que habita desde el Chaco de Bolivia y Paraguay hasta el sur de la provincia de Santa Cruz en Argentina, ha sido introducida en la Isla Grande de Tierra del Fuego hace unos 20 años. Las cuevas y hoyos son las evidencias indirectas más conspicuas de la actividad de esta especie y son utilizados en este trabajo para determinar la distribución y estimar la abundancia relativa de la población de armadillos en el sector argentino de la Isla Grande. Se clasificó a las cuevas en "cortas" para refugio temporario y/o forrajeo y "largas", de uso como madriguera o semipermanente. Chaetophractus villosus es una especie establecida en la isla donde ocupa un área de unos 484 km² y su distribución se encuentra asociada a la red de tuberías soterradas para extracción y transporte de hidrocarburos, debido a las modificaciones físicas que esta actividad causa en el suelo. Aunque la población es aún pequeña, se considera que dada la distribución alcanzada por C. villosus a partir de la introducción de pocos individuos y teniendo en cuenta las condiciones climáticas de la región, es posible que no sea el clima un factor determinante en la distribución de esta especie sino las barreras geográficas como el Estrecho de Magallanes al sur y el Río de La Plata hacia el esteSixty-six percent of the mammal fauna of Tierra del Fuego consists of introduced species with economical or sport hunting importance. The large hairy armadillo, Chaetophractus villosus, is distributed from the Chaco of Bolivia and Paraguay to the South of Santa Cruz province in Argentina and was introduced to Isla Grande about 20 years ago. Since the holes and subterranean excavations are the most conspicuous indications of

  13. TRP channels in kidney disease.

    NARCIS (Netherlands)

    Hsu, Y.J.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Mammalian TRP channel proteins form six-transmembrane cation-permeable channels that may be grouped into six subfamilies on the basis of amino acid sequence homology (TRPC, TRPV, TRPM, TRPA, TRPP, and TRPML). Recent studies of TRP channels indicate that they are involved in numerous fundamental cell

  14. Parallel inter channel interaction mechanisms

    International Nuclear Information System (INIS)

    Jovic, V.; Afgan, N.; Jovic, L.

    1995-01-01

    Parallel channels interactions are examined. For experimental researches of nonstationary regimes flow in three parallel vertical channels results of phenomenon analysis and mechanisms of parallel channel interaction for adiabatic condition of one-phase fluid and two-phase mixture flow are shown. (author)

  15. La península de Paraguaná: Un paisaje natural para la enseñanza de la morfología litoral en Ciencias de la Tierra

    Directory of Open Access Journals (Sweden)

    Belmary Cecilia Barreto Pineda

    2016-12-01

    Full Text Available Esta investigación busca proponer el paisaje natural de la Península de Paraguaná como recurso didáctico en la asignatura Ciencias de la Tierra en la U.E.P John Wycliff. Con una metodología descriptiva, de proyecto factible, incluyendo una fase documental y diseño de campo no experimental. En relación al diagnóstico de los “Recursos Didácticos”, el 79% de los encuestados afirman que no se utilizan paisajes para impartir clases de Ciencias de la Tierra debido a la falta de motivación de los docentes por implementar recursos que se relacionen con el paisaje natural. Se generó una propuesta representada por un paquete didáctico constituido por la sección preliminar, fundamentos teóricos, video educativo, catálogo fotográfico, referencias bibliográficas e itinerario geográfico pedagógico que interrelacionan al estudiante con el entorno. Se recomienda su aplicación para los contenidos sobre Morfología litoral en Ciencias de la Tierra. Palabras Clave:  Recurso didáctico, paisaje natural, ciencias de la tierra, educación Paraguaná's Peninsula: A Natural Landscape for Teaching Coastal Morphology in Sciences of the Earth Abstract This investigation will propose the natural landscape of Paraguaná's Peninsula as a didactic resource in the subject Earth Sciences in the U.E.P John Wycliff. It was made using a descriptive methodology and a feasible project, with a documentary phase and non-experimental design field. In relation to the diagnosis of the “Didactic Resources", 79% of the respondents affirmed that landscapes are not used as part of the Teaching Program for Earth Sciences, due to the lack of motivation of teachers to implement resources that relate to the natural landscape. It was generated an offer based on the natural landscape of Paraguaná's Peninsula as a resource for teaching Earth Sciences, represented by a didactic package, structured with a preliminary section, theoretical foundations, educational video

  16. Inventario y evaluación semidetallada de los recursos de suelos, forestales y uso actual de la tierra de la cuenca alta del río Mayo: sector río Tumbaro - río Avisado

    OpenAIRE

    Oficina Nacional de Evaluación de Recursos Naturales

    1983-01-01

    Determina a nivel de semidetalle, el potencial y grado de utilización de los recursos suelos y forestales, así como el uso actual de la tierra de la cuenca alta del río Mayo, sector río Túmbaro - río Avisado, situada en el Norte del departamento de San Martín. El estudio, fue ejecutado en un sector con potencial agropecuario y comprendió una profundización del conocimiento de los recursos relacionados con estas actividades, con el fin de establecer y reordenar asentamientos humanos, formular ...

  17. Diseño e implementación de instalación électrica, electromecánica y sistema de puesta a tierra para el Catamaran Ocean Spray

    OpenAIRE

    Moreira Mite, Enrique Francisco; Camacho Delgado, Ricardo Javier

    2012-01-01

    Diseño e implementación de implementación de instalación eléctrica y puesta a tierra de una embarcación tipo   Catamaran. Siendo el turismo una fuente de ingreso económico muy importante para el país especialmente en las islas Galápagos, la asociación de armadores de Galápagos se encuentran en la necesidad de ampliar los medios para un mejor servicio a los turistas en los lugares de visita dentro de las islas, se proponen construir nuevas embarcaciones que cumplan con todas las seguridad...

  18. Remoción de Arsenico (V) y cromo (VI) presente en lechos acuáticos mediante el uso de tierra de diatomeas recubierta con sales de hierrro Arequipa 2016

    OpenAIRE

    Rojas Tamata, Karen

    2016-01-01

    RESUMEN La región de Arequipa cuenta con recursos naturales minerales y no minerales con mucho potencial comercial, entre ellas se destaca a la tierra de diatomeas, el 23% de las diatomeas del Perú están en nuestra región; por la naturaleza del terreno volcánico la presencia de arsénico es inminente en el agua, además existen empresas dedicadas a la curtiembre del cuero que eliminan sus desechos sin ningún otro tipo de tratamiento, por lo cual existen concentraciones elevadas de dichos m...

  19. Nivel de depredación de tierras agrícolas y deterioro ambiental en el sector alto de la campiña del distrito de moche

    OpenAIRE

    Mori Ramírez, Pepe Oswaldo

    2008-01-01

    El crecimiento de la población implica habilitar el espacio territorial para viviendas, reduciendo áreas rurales, ecosistemas y paisajes naturales, y superficies productiva, culturales y modos de vida. Las variables, expansión urbana y sustentabilidad ambiental, indican el deterioro ambiental trayendo como consecuencia la contaminación, agotamiento de recursos naturales y baja calidad de vida humana. Esta investigación se orienta a determinar el nivel de depredación de tierras agrícolas, yu ...

  20. De tierras de resguardo, solicitudes y querellas: participación política de indígenas caucanos en la construcción estatal (1850-1885)

    OpenAIRE

    Muñoz, Fernanda

    2015-01-01

    Apelar a la justicia constituyó una de las vías a través de las cuales los indígenas del territorio caucano, entre 1850 y 1885 -en el contexto de la Confederación Granadina y los Estados Unidos de Colombia-, se hicieron escuchar. Por medio de memoriales y representaciones, esta población se dirigió a las instancias gubernativas para solicitar fracciones de terreno a título individual o defender sus tierras de resguardo y bienes comunales. Aquí se sostiene que dichas manifestaciones constituye...

  1. De la apropiación terrateniente a la expansión del capital: notas desde una visión histórica sobre la concentración y los conflictos por la tierra

    OpenAIRE

    Martínez Dougnac, Gabriela

    2014-01-01

    Se abordan algunas notas y reflexiones que resultan de una investigación en curso acerca de los procesos de concentración de la tierra agrícola en nuestro país. El tema se aborda desde una perspectiva histórica, intentando explicar el actual acaparamiento y el despojo a los productores directos y a la sociedad que de éste resulta, atendiendo tanto a las tendencias de larga duración propias del desarrollo del capitalismo en al agro y a sus condiciones presentes, como a las formas act...

  2. Primer registro de Dasypsyllus (Avesopsylla lasius lasius (Siphonaptera: Ceratophyllidae en nidos de golondrina chilena, Tachycineta meyeni (Passeriformes: Hirundinidae, en Ushuaia (Tierra del Fuego, Argentina First record of Dasypsyllus (Avesopsylla lasius lasius (Siphonaptera: Ceratophyllidae in Chilean swallow nests Tachycineta meyeni (Passeriformes: Hirundinidae in Ushuaia (Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Rosana Aramburú

    2009-12-01

    Full Text Available La golondrina chilena, Tachycineta meyeni (Cabanis, nidifica en el centro de Chile y suroeste de Argentina. En invierno migra a Bolivia, Paraguay y al sureste de Brasil. Estas golondrinas ocuparon una serie de cajas-nido en Ushuaia, Tierra del Fuego. Luego de la temporada de cría, tratamos los nidos con acetato de etilo y los revisamos en búsqueda de artrópodos hematófagos. Encontramos pulgas adultas, que fueron fijadas, aclaradas, deshidratadas, diafanizadas y montadas en un derivado de clavo de olor para su observación al microsocopio óptico. Identificamos machos y hembras de Dasypsyllus (Avesopsylla lasius lasius (Rothschild. En Argentina, esta pulga es conocida solamente en Sierra de la Ventana (Buenos Aires, donde se la halló parasitando la golondrina barranquera, Notiochelidon cyanoleuca patagonica (Vieillot. La información disponible debería complementarse con prospecciones en localidades intermedias. Otras aves relacionadas con ambas golondrinas por la ocupación de nidos, como el rayadito (Aphrastura spinicauda (Gmelin, ratona común (Troglodytes aedon Vieillot, caminera común (Geositta cunicularia (Vieillot, hornero (Furnarius rufus (Gmelin, podrían contribuir a la dispersión de la pulga entre las dos localidades registradas.Chilean swallows Tachycineta meyeni (Cabanis nest in the central area in Chile and Southwest in Argentina. In winter, they migrate to Bolivia, Paraguay and Southeast of Brazil. A nest box population of Chilean swallows was established in Ushuaia, Tierra del Fuego. After the breeding season, we collected all nests, treated them with ethyl acetate, and inspected all the nest material for hematophagous arthropods. We found adult fleas, which were fixed, cleared, diaphanized, dehydrated, and mounted in a clove derivative for observation under a microscope. We identified males and females of Dasypsyllus (Avesopsylla lasius lasius (Rothschild. In Argentina, this flea is only known for Sierra de la Ventana

  3. Fusiform Rust of Southern Pines

    Science.gov (United States)

    W. R. Phelps; F. L. Czabator

    1978-01-01

    Fusiform rust, caused by the fungus Cronartium fusiforme Hedg. & Hunt ex Cumm., is distributed in the Southern United States from Maryland to Florida and west to Texas and southern Arkansas. Infections by the fungus, which develops at or near the point of infection, result in tapered, spindle-shaped swells, called galls, on branches and stems of pines. (see photo...

  4. Shakespeare in Southern Africa: Submissions

    African Journals Online (AJOL)

    Shakespeare in Southern Africa publishes articles, commentary and reviews on all aspects of Shakespearean studies and performance, with a particular emphasis on responses to Shakespeare in southern Africa. Submissions are reviewed by at least two referees. The practice of 'blind' reviewing is adhered to. The Journal ...

  5. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    Science.gov (United States)

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J. J.; Lodolo, Emanuele

    2015-12-01

    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from E-W in the Patagonian Andes to N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled

  6. Voltage-Gated Calcium Channels

    Science.gov (United States)

    Zamponi, Gerald Werner

    Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

  7. Tornado Strikes Southern Maryland

    Science.gov (United States)

    2002-01-01

    Evening light catches the tops of towering thunderheads over the Mid-Atlantic states on April 28, 2002. The powerful storms spawned several tornados, one of which was classified as an F4 tornado. The powerful tornado touched down in the southern Maryland town of La Plata, destroying most of the historic downtown. The twister-one of the strongest ever to hit the state-beat a 24-mile swath running west to east through the state and claimed at least three lives. The image above was taken by the Geostationary Operational Environmental Satellite (GOES) at 7:15 PM Eastern Daylight Savings Time. A large version of the animation shows more detail. (5.9 MB Quicktime) Image courtesy National Oceanic and Atmospheric Administration (NOAA) and the GOES Project Science Office. Animation by Robert Simmon, NASA GSFC.

  8. Sightings of Delphinus delphis (Cetacea, Odontoceti in the Otranto Channel (Southern Adriatic Sea and Northern Ionian Sea / Avvistamenti di Delphinus delphis (Cetacea, Odontoceti nel Canale d'Otranto (Mar Adriatico Meridionale e Mar Ionio Settentrionale

    Directory of Open Access Journals (Sweden)

    Francesco Maria Angelici

    1992-07-01

    Full Text Available Abstract Two sightings of Common dolphin Delphinus delphis in the Channel of Otranto are reported, and the status of this species in the Mediterranean Sea is briefly discussed. Riassunto Sono riportati due avvistamenti di Delfino comune Delphinus delphis nel Canale d'Otranto, lungo la costa greca e quella italiana. Viene inoltre brevemente commentata la frequenza degli avvistamenti e degli spiaggiamenti di tale specie nel Mar Mediterraneo.

  9. Classification and sedimentary characteristics of lacustrine hyperpycnal channels: Triassic outcrops in the south Ordos Basin, central China

    Science.gov (United States)

    Xian, Benzhong; Wang, Junhui; Gong, Chenglin; Yin, Yu; Chao, Chuzhi; Liu, Jianping; Zhang, Guodong; Yan, Qi

    2018-06-01

    Subaquatic channels are known as active conduits for the delivery of terrigenous sediments into related marine and lacustrine basins, as well as important targets for hydrocarbon exploration. Compared to submarine channels, lacustrine subaqueous channels created by hyperpycnal flows are understudied. Using well-exposed outcrops collected from three different locations in the southern Ordos Basin, central China, morphologies and architecture of a channelized hyperpycnal system were studied and classified. Six facies associations represent sedimentary processes from strong erosion by bedload dominated hyperpycnal flows, to transitional deposition jointly controlled by bedload and suspended-load dominated hyperpycnal flows, finally to deposition from suspended-load dominated hyperpycnal flows. On the basis of channel morphologies, infilling sediments and sedimentary processes, the documented channels can be classified into four main categories, which are erosional, bedload dominated, suspended-load dominated, and depositional channels. In very proximal and very distal locations, erosional channels and depositional channels serve as two end-members, while in middle areas, bedload-dominated channels and suspended-load dominated channels are transitional types. Erosional channels, as a response to strong erosion from bedload dominated hyperpycnal flows on upper slope, were mainly filled by mud interbedded with thin sand beds. As flow energy decreases, bedload dominated channels develop on middle slopes, which are characterized mainly by under- to balanced sediment infillings with cross-bedded sandstones and/or minor massive sandstones. Compared to bedload dominated channels, suspended-load dominated channels mainly develop in deeper water, and were filled mainly by massive or planar-laminated sandstones. Depositional channels, as a response to suspended-load dominated hyperpycnal flows in deep-water areas, are characterized by thin-medium bed classical turbidites with

  10. 47 CFR 90.315 - Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17...

    Science.gov (United States)

    2010-10-01

    ... in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone. 90... RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Authorization in the Band 470-512 MHz (UHF-TV Sharing) § 90.315 Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16...

  11. Beyond the Manual Channel

    DEFF Research Database (Denmark)

    , the main focus there is on spoken languages in their written and spoken forms. This series of workshops, however, offers a forum for researchers focussing on sign languages. For the fourth time, the workshop had sign language corpora as its main topic. This time, the focus was on any aspect beyond...... the manual channel. Not surprisingly, most papers deal with non-manuals on the face. Once again, the papers at this workshop clearly identify the potentials of even closer cooperation between sign linguists and sign language engineers, and we think it is events like this that contribute a lot to a better...

  12. Ion Channels in Leukocytes

    Science.gov (United States)

    1991-07-01

    muscle k142), heart muscle (80), bo- are released. In recent years much has been learned vine pulmonar arter endothelial cells (251), and rat about the...b3 Zn or cytes from cystic fibrosis patients lack a Cl current that Ni (1 mM)-added to the cytoplasmic side of the mem- can be acti% ated b3 the...that at37’C hu- to be defectiv.- in cystic fibrosis (55, 277), and Chen et al. man T-cell CiL channels are active at rest, implies that (25) have shown

  13. A Micromechanical RF Channelizer

    Science.gov (United States)

    Akgul, Mehmet

    The power consumption of a radio generally goes as the number and strength of the RF signals it must process. In particular, a radio receiver would consume much less power if the signal presented to its electronics contained only the desired signal in a tiny percent bandwidth frequency channel, rather than the typical mix of signals containing unwanted energy outside the desired channel. Unfortunately, a lack of filters capable of selecting single channel bandwidths at RF forces the front-ends of contemporary receivers to accept unwanted signals, and thus, to operate with sub-optimal efficiency. This dissertation focuses on the degree to which capacitive-gap transduced micromechanical resonators can achieve the aforementioned RF channel-selecting filters. It aims to first show theoretically that with appropriate scaling capacitive-gap transducers are strong enough to meet the needed coupling requirements; and second, to fully detail an architecture and design procedure needed to realize said filters. Finally, this dissertation provides an actual experimentally demonstrated RF channel-select filter designed using the developed procedures and confirming theoretical predictions. Specifically, this dissertation introduces four methods that make possible the design and fabrication of RF channel-select filters. The first of these introduces a small-signal equivalent circuit for parallel-plate capacitive-gap transduced micromechanical resonators that employs negative capacitance to model the dependence of resonance frequency on electrical stiffness in a way that facilitates the analysis of micromechanical circuits loaded with arbitrary electrical impedances. The new circuit model not only correctly predicts the dependence of electrical stiffness on the impedances loading the input and output electrodes of parallel-plate capacitive-gap transduced micromechanical device, but does so in a visually intuitive way that identifies current drive as most appropriate for

  14. TRPV6 channels.

    Science.gov (United States)

    Fecher-Trost, Claudia; Weissgerber, Petra; Wissenbach, Ulrich

    2014-01-01

    TRPV6 (former synonyms ECAC2, CaT1, CaT-like) displays several specific features which makes it unique among the members of the mammalian Trp gene family (1) TRPV6 (and its closest relative, TRPV5) are the only highly Ca(2+)-selective channels of the entire TRP superfamily (Peng et al. 1999; Wissenbach et al. 2001; Voets et al. 2004). (2) Translation of Trpv6 initiates at a non-AUG codon, at ACG, located upstream of the annotated AUG, which is not used for initiation (Fecher-Trost et al. 2013). The ACG codon is nevertheless decoded by methionine. Not only a very rare event in eukaryotic biology, the full-length TRPV6 protein existing in vivo comprises an amino terminus extended by 40 amino acid residues compared to the annotated truncated TRPV6 protein which has been used in most studies on TRPV6 channel activity so far. (In the following numbering occurs according to this full-length protein, with the numbers of the so far annotated truncated protein in brackets). (3) Only in humans a coupled polymorphism of Trpv6 exists causing three amino acid exchanges and resulting in an ancestral Trpv6 haplotype and a so-called derived Trpv6 haplotype (Wissenbach et al. 2001). The ancestral allele encodes the amino acid residues C197(157), M418(378) and M721(681) and the derived alleles R197(157), V418(378) and T721(681). The ancestral haplotype is found in all species, the derived Trpv6 haplotype has only been identified in humans, and its frequency increases with the distance to the African continent. Apparently the Trpv6 gene has been a strong target for selection in humans, and its derived variant is one of the few examples showing consistently differences to the orthologues genes of other primates (Akey et al. 2004, 2006; Stajich and Hahn 2005; Hughes et al. 2008). (4) The Trpv6 gene expression is significantly upregulated in several human malignancies including the most common cancers, prostate and breast cancer (Wissenbach et al. 2001; Zhuang et al. 2002; Fixemer et al

  15. SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism Geocronología SHRIMP del basamento de la Cuenca de Magallanes, Tierra del Fuego: plutonismo Cámbrico y metamorfismo Pérmico de alto grado

    Directory of Open Access Journals (Sweden)

    Francisco Hervé

    2010-07-01

    Full Text Available Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC, obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (523±7 Ma, 522±6 Ma and 538±6 Ma, interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770°C event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobífera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.Cinco nuevas edades radiométricas logradas mediante análisis U-Pb en circón utilizando el SHRIMP, fueron determinadas en gneises y rocas plutónicas foliadas obtenidas desde el fondo de pozos de sondajes en la Cuenca de Magallanes y

  16. Mimicking multi-channel scattering with single-channel approaches

    OpenAIRE

    Grishkevich, Sergey; Schneider, Philipp-Immanuel; Vanne, Yulian V.; Saenz, Alejandro

    2009-01-01

    The collision of two atoms is an intrinsic multi-channel (MC) problem as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold 6Li and 87Rb atoms in the ground state and in the ...

  17. Ecology of southern ocean pack ice.

    Science.gov (United States)

    Brierley, Andrew S; Thomas, David N

    2002-01-01

    Around Antarctica the annual five-fold growth and decay of sea ice is the most prominent physical process and has a profound impact on marine life there. In winter the pack ice canopy extends to cover almost 20 million square kilometres--some 8% of the southern hemisphere and an area larger than the Antarctic continent itself (13.2 million square kilometres)--and is one of the largest, most dynamic ecosystems on earth. Biological activity is associated with all physical components of the sea-ice system: the sea-ice surface; the internal sea-ice matrix and brine channel system; the underside of sea ice and the waters in the vicinity of sea ice that are modified by the presence of sea ice. Microbial and microalgal communities proliferate on and within sea ice and are grazed by a wide range of proto- and macrozooplankton that inhabit the sea ice in large concentrations. Grazing organisms also exploit biogenic material released from the sea ice at ice break-up or melt. Although rates of primary production in the underlying water column are often low because of shading by sea-ice cover, sea ice itself forms a substratum that provides standing stocks of bacteria, algae and grazers significantly higher than those in ice-free areas. Decay of sea ice in summer releases particulate and dissolved organic matter to the water column, playing a major role in biogeochemical cycling as well as seeding water column phytoplankton blooms. Numerous zooplankton species graze sea-ice algae, benefiting additionally because the overlying sea-ice ceiling provides a refuge from surface predators. Sea ice is an important nursery habitat for Antarctic krill, the pivotal species in the Southern Ocean marine ecosystem. Some deep-water fish migrate to shallow depths beneath sea ice to exploit the elevated concentrations of some zooplankton there. The increased secondary production associated with pack ice and the sea-ice edge is exploited by many higher predators, with seals, seabirds and whales

  18. Channel changes following headwater reforestation: The Ganaraska river, Ontario, Canada

    International Nuclear Information System (INIS)

    Buttle, J.M.

    1995-01-01

    Reforestation of headwater slopes of the Ganaraska River basin in southern Ontario following World War II has resulted in decreased peak flows and has likely reduced sediment yields. Changes in channel morphology produced by these modifications to the hydrologic regime were examined for a 6.7 km section of river in the context of Schumm's (1977) qualitative model of channel response to reforestation. Flood channel width (measured from air photographs) has decreased since 1928, while cross-sectional measurements during stream gauging in the study section revealed a decrease in the channel's width/depth ratio between 1960 and 1975. Both of these trends agree with Schumm's model. Changes in channel planform were dominated by downstream translation of meander bends and by meander cutoffs. The model predicted an increase in channel sinuosity in response to decreased peak flows and bed-material yield from the basin. However, sinuosity for the entire river section decreased significantly between 1928 and 1988, and only one reach experienced an increase in sinuosity following reforestation. A possible explanation for the model's failure to describe temporal changes in the Ganaraska's sinuosity involves a negative feedback whereby the increased sinuosity produced by decreased flow and sediment yield enhances potential for ice jams and meander cutoffs, which in turn reduce sinuosity. This limited test of Schumm's model suggests that caution be used when applying the model and its variants to reconstructions of basin palaeohydrology, and predictions of channel response to anthropogenic and natural changes to the hydrologic regime. 31 refs, 11 figs, 1 tab

  19. Health disparities between island and mainland Puerto Ricans Disparidades de salud entre puertorriqueños que viven en la isla de Puerto Rico y en tierra firme estadounidense

    Directory of Open Access Journals (Sweden)

    Gloria Y. F. Ho

    2006-05-01

    associated with the poor health status observed in mainland Puerto Ricans.OBJETIVO: Detectar disparidades de salud entre tres poblaciones: puertorriqueños que viven en Puerto Rico, así como puertorriqueños y personas no hispanas de raza blanca que viven en tierra firme estadounidense. MÉTODOS: Se analizaron los datos obtenidos mediante dos encuestas de similar diseño que se realizaron en 1999-2000. El Sistema de Vigilancia de Factores de Riesgo Conductuales proporcionó datos acerca de los puertorriqueños radicados en la isla y de residentes de Estados Unidos de raza blanca que no son hispanos. Otra encuesta de puertorriqueños radicados en la Ciudad de Nueva York aportó datos acerca de los puertorriqueños que residían en tierra firme estadounidense. Se usaron las razones de las tasas estandarizadas (standardized rate ratios, SRR para hacer las comparaciones interpoblacionales de las prevalencias ponderadas, estandarizadas por edad y sexo, de varios parámetros (obesidad, diabetes, tabaquismo y dolencias físicas y de indicadores de acceso a la atención sanitaria (frecuencia de los exámenes de rutina y de la atención de la diabetes. RESULTADOS: Los puertorriqueños que vivían en tierra firme estadounidense y los que vivían en la isla tuvieron una prevalencia de obesidad parecida (21% a 22%. Comparados con los habitantes de la isla, los puertorriqueños radicados en tierra firme tuvieron una prevalencia de diabetes más alta (SRR = 1,4; intervalo de confianza de 95% [IC95%]: 1,01 a 2,0; los que tenían diabetes también mostraron una mayor prevalencia de tabaquismo (SRR = 4,2; IC 95%: 2,3 a 7,7 y de dolencias físicas (SRR = 1,5%; IC95%: 1,1 a 2,0 que los puertorriqueños que vivían en la isla. Mientras que los puertorriqueños en tierra firme se asemejaron a los blancos que no eran hispanos en cuanto a la utilización de servicios de prevención primaria y de atención de la diabetes, los puertorriqueños en la isla tenían cifras de utilización mucho m

  20. PAST: Programa para el proyecto y análisis de sistemas de puesta a tierra. (Primera parte; SistPTEx: Program for the project and analysis of grounding system. (First part.

    Directory of Open Access Journals (Sweden)

    Angel Cecilio Valcárcel Rojas

    2011-05-01

    Full Text Available resistencia de contacto a tierra de diferentes configuraciones de electrodos, desde métodos aproximados, métodos semiexactos, hasta métodos que garantizan muy buenos niveles de exactitud. El desarrollo alcanzado por la computación ha permitido el rescate de algoritmos relativamente antiguos como los basados en la teoría de las imágenes de Maxwell, hasta el desarrollo de métodos basados en la teoría de los elementos finitos. En este trabajo se exponen las características y bondades de un programa para el proyecto y análisis de sistemas de puesta a tierra para cualquier instalación eléctrica, aplicando la teoría de las imágenes de Maxwell.  During the historical development of electrical engineering, have developed many methods for calculating the contact resistance grounding electrodes of different configurations, from approximate methods, semi exact methods up methods which guarantee good levels of exactness. The development achieved by the computer has enabled the rescue of relatively old algorithms, such as those based on the theory of Maxwell’s images, until the development of methods based on the theory of finite elements. In this paper we describe the features and benefits of a program for the design and analysis of grounding systems for any electrical installation, using the theory of Maxwell’s images.

  1. Tácticas de gobierno en la política de protección de tierras de la población desplazada en Colombia: Una etnográfica del Estado

    Directory of Open Access Journals (Sweden)

    Nadia Margarita Rodríguez J.

    2016-09-01

    Full Text Available La política de protección de tierras para la población desplazada en Colombia tiene un proceso de implementación largo y complejo, que ocurre entre 1997 y 2011. Este resulta interesante, ya que permite analizar la superposición de diferentes lógicas de gobierno, y diferentes formas de acceso al poder, que pueden ser analizadas desde diversas perspectivas de la Antropología política. El artículo presenta algunos debates teóricos y metodológicos sobre el estudio etnográfico del Estado y del análisis de estas distintas fuerzas políticas que conforman la gubernamentalidad, aplicadas al caso de la política de protección de tierras. En particular, se analizan las interacciones entre distintos actores y fuerzas que se gestaron dentro y fuera de un proyecto del gobierno con características particulares, y se narran desde la perspectiva de los funcionarios. Todo ello, intentando develar también el margen de maniobra de los funcionarios en el ejercicio del poder en el gobierno.

  2. LA DINÁMICA DEL USO DE LA TIERRA EN MATO GROSSO: ASPECTOS ECONÓMICOS DEL CULTIVO DE ARROZ, SOYA Y PASTOS

    Directory of Open Access Journals (Sweden)

    Dilamar Dallemole

    2014-08-01

    Full Text Available El cultivo de arroz siempre estuvo presente en el rol de culturas practicadas en el cerrado brasileño, en especial, en el Mato-grossense. Dado a esa particularidad, éste estudio busca comprender mejor las relaciones existentes entre la producción de arroz con las áreas plantadas de soya, y, propiamente, con la área plantada de arroz en Mato Grosso, en el período de 1979 a 2007. Debido a la gran extensión territorial del estado, el cultivo de arroz fue siendo realizado a lo largo de los años como frontera agrícola, para apertura de nuevas áreas, con variedades adecuadas a tierras, inicialmente, con baja fertilidad. Con el desarrollo tecnológico y la posibilidad de nuevas actividades productivas, esa realidad viene se alterando y la área plantada de arroz disminuyó a lo largo de los años, perdiendo espacio para la soya y pastos. Como instrumento metodológico, se empleó un modelo de regresión múltiple, estimada por el Método de Mínimos Cuadrados Ordinarios (MQO, en que los resultados apuntan las correlaciones existentes entre las categorías mencionadas, lo que permite analizar con más propiedad lo que está ocurriendo con el segmento. Las principales conclusiones obtenidas confirman la influencia positiva de la producción de arroz con relación a suya área plantada, sin embargo, negativa para las áreas plantadas de soya, pastos y arroz en Mato Grosso. Aunque venga perdiendo espacio para soya y pastos, el cultivo de arroz, mismo con menor productividad y calidad inferior del grano, aún es practicado debido a su capacidad de adaptación en nuevas áreas, o mismo, en áreas degradadas

  3. Primeros resultados del trabajo de investigación sobre la tierra como material de construcción, en el IETCC

    Directory of Open Access Journals (Sweden)

    Salas, Julián

    1986-02-01

    Full Text Available This work presents the first results from the researches based in the up to date earth constructions, taking into account its interest according to the new possibilities they offer, considering the energetic crisis and, fundamentally, the need to use local resources and feasible solutions in developing countries. Thinking about the main problems of this kind of construction, its short capacity of response to climate conditions -critical in humid environment- we pretend to establish valid parameters for mechanical behaviour so as for resistance under rain. After a first classification phase and soil identification, series of samples with different dosage, cement, fly ash and other chemical aggregates, were made, establishing relational parameters between different form and resistant behaviour rates. From those dosages, behaviour under dripping and in winter atmosphere in Madrid, were studied.El trabajo recoge los primeros resultados de la investigación basada en la nueva realidad de las construcciones a base de tierra, teniendo presente su interés ante las nuevas posibilidades que ofrece a la luz de la crisis energética y, fundamentalmente, por la necesidad de utilización de recursos locales y soluciones viables en países en vías de desarrollo. Considerado entre los principales problemas de este tipo de construcciones su limitada capacidad de respuesta ante los agentes atmosféricos -crítica en ambientes húmedos- se pretende establecer parámetros válidos tanto para el comportamiento mecánico, como para su aptitud frente al agua. Superada una primera fase de clasificación, e identificación de los suelos, se han realizado series de probetas con distintas dosificaciones de cal, cemento, cenizas volantes y otros aditivos químicos, estableciendo parámetros de relación entre distintos coeficientes de forma y comportamiento resistente. De estas dosificaciones se ha estudiado su comportamiento frente a ensayo de goteo y exposici

  4. Hacia una taxonomía constructiva de las tapias de tierra y fábricas encofradas históricas

    Directory of Open Access Journals (Sweden)

    Gil-Crespo, I. J.

    2015-06-01

    Full Text Available The principal aim of the research is the study of the constructive reasons of the historical masonries built with rammed earth and formwork masonry, belonging to late medieval fortifications. Uncertainties have been warned about dating the historical masonries and there are excessive exceptions that do not fall in the rankings traditionally employed to study these techniques. Due to these reasons, the article develops a proposal of constructive typology or taxonomy based in an open system that comes from the analysis of a representative number of masonries and that attends to several control parameters tor the complete characterization of each masonry: material, compaction degree, constructive function, formwork, rendering, combination of materials and, last, the situation, deepness, formation and section of the putlogholes. Each masonry is classified through an alphanumeric label. The system allows establishing several constructive types which it is possible to do a cronotypological and constructive classification.El objetivo fundamental de la investigación es el estudio de los fundamentos constructivos de las fábricas históricas de tapia de tierra y mampostería encofrada de las fortificaciones bajomedievales. Ante las incertidumbres detectadas en la datación de estas estructuras y frente al excesivo número de excepciones que quedan fuera de las clasificaciones tradicionalmente empleadas para estudiar este tipo de técnicas, el artículo desarrolla una propuesta de tipología o taxonomía constructiva basada en un sistema abierto. Este sistema nace del análisis de un número significativo de fábricas y atiende a diversos parámetros de control para la completa caracterización de cada fábrica: material, grado de compactación, función constructiva, encofrado, acabado superficial, combinación de materiales y situación, profundidad, formación y sección de los agujales. Cada fábrica se clasifica mediante una etiqueta alfanum

  5. ENTRE EL PROGRESO Y EL ABUSO: PROBLEMÁTICA SOCIAL EN TORNO A LAS TIERRAS PROTEGIDAS DE LAS COMUNIDADES NATIVAS EN EL PERÚ

    Directory of Open Access Journals (Sweden)

    Jerjes Loayza Javier

    2011-12-01

    Full Text Available Normal 0 21 false false false ES-AR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Se busca comprender el fenómeno de los conflictos sociales en torno a la irrupción del Estado peruano en tierras legalmente protegidas, provocando malestar y profunda deslegitimación política de la representatividad democrática. Para ello se  analizan críticamente las contradicciones existentes entre el marco legal peruano e internacional más importante dirigido a proteger a las comunidades indígenas, el discurso del Estado amparado en la dicotomía “progreso-atraso” sustentadas por el Presidente de la República y las consecuencias de las prácticas políticas estatales desvinculadas del diálogo y el respeto hacia los pueblos originarios. Se hará especial énfasis en el conflicto social suscitado en las provincias de Bagua y Uctubamba ubicadas en la selva peruana en el año 2009, ya que éste trajo a colación un intenso debate en torno a un escenario no resuelto en nuestro país: la situación de los pueblos indígenas y sus derechos, aunque estipulados en la carta magna peruana, minimizados en la práctica, reforzando, así, el debate relacionado a la necesidad de una triple categoría Medio ambiente-población-sistema social. En adelante será necesario aunar tanto libertad econ

  6. Ventajas del reforzamiento de muros de bloques de tierra compactados (BTC, como opción para el rescate de viviendas rurales

    Directory of Open Access Journals (Sweden)

    Juárez, L. A.

    2010-06-01

    Full Text Available Experimental research was made in compressed soil block (BTC piles. These specimens were reinforced with hexagonal mesh and welded wire mesh to determinate its mechanics characteristics by means of axial and diagonal compression, and flexion tests. We made experimental assays in accord with Mexican Code specifications of NTCM(1 and UNAM(2 Engineering Institute researchers. In axial compression test, the piles reinforced with welded wire mesh had a significant increase in maxim admissible load (39% but had not in masonry strength (4%. In diagonal compression test, the reinforced groups had significant increases in both, load capacity (90-125% and masonry strength (60-83%. The strength and deformation capacity were higher in specimens reinforced with welded wire mesh. In the flexion test had similar results. Although the compression, shear and flexion design parameters was determinate, it’s important and necessary to make more tests to corroborate these results.

    Se realizó una investigación experimental en pilas de bloques de tierra compactados (BTC reforzadas con malla hexagonal y malla electrosoldada para determinar la influencia del refuerzo, mediante ensayes de compresión axial, compresión diagonal y flexión lateral, según lo especifican las Normas Técnicas Complementarias para Mampostería (NTCM(1 y UNAM(2 del DF, en México. En el ensayo a compresión axial, se determinó que la carga máxima admisible se incrementó significativamente en el grupo reforzado con malla electrosoldada (39%, no así la resistencia (4%. En el ensaye a compresión diagonal, el incremento en la carga máxima admisible y resistencia fue significativo para los dos grupos reforzados, de 90 a 125% y de 60 a 83% respectivamente. A flexión lateral los incrementos fueron altamente significativos para el grupo reforzado con malla electrosoldada. Aunque se determinaron los parámetros de diseño a compresión, cortante y flexión del BTC, es importante

  7. DISPERSIÓN PRIMARIA DIURNA DE SEMILLAS DE DACRYODES CHIMANTENSIS Y PROTIUM PANICULATUM (BURSERACEAE EN UN BOSQUE DE TIERRA FIRME DE LA AMAZONIA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    ROZO-MORA MARÍA CAROLINA

    2004-06-01

    Full Text Available Estudiamos la dispersión primaria diurna de las semillas de Dacryodes chimantensisy Protium paniculatum (Burseraceae en un bosque de tierra firme de la Amazoniacolombiana. Desde diciembre de 1999 hasta junio de 2000 registramos las visitas defrugívoros, la remoción de frutos y la dispersión primaria de semillas de cincoindividuos por especie. Encontramos que D. chimantensis presenta en promediouna mayor altura, DAP, área de proyección de la copa y mayores cosechas que P.paniculatum. El porcentaje del valor promedio de frutos maduros de D. chimantensisosciló entre el 3 y el 21% del tamaño de la cosecha durante toda la estación de frutos,mientras que este porcentaje en P. paniculatum varió entre el 1 y 15%. Observamosactividad frugívora diurna en cuatro de los cinco individuos de D. chimantensisestudiados, mientras que en los individuos de P. paniculatum no se presentófrugivoría diurna. Únicamente Amazona festiva y A. amazonica consumieron frutosde D. chimantensis y removieron en promedio 1.8 % de los frutos por árbol, pero noalejaron semillas viables del parental (dispersión primaria. En las trampas ubicadasbajo el área de la proyección de la copa sobre el suelo, encontramos que el númerode frutos probados, intactos y dañados por frugívoros fue similar para las dosespecies. Las cosechas pequeñas, el número reducido de frutos maduros y las bajastasas de reducción de la cosecha, sumado a las pocas visitas diurnas, la baja remocióny dispersión primaria diurna de semillas por parte de los frugívoros, sugieren queestas dos especies tuvieron una dispersión limitada. Discutimos si la dispersión poranimales puede estar modelando la abundancia y los patrones de distribución espacialde estas especies.

  8. Comparación del sistema constructivo de Putucos con otros sistemas constructivos en tierra = Comparison of the construction system of Putucos with other construction systems in earth

    Directory of Open Access Journals (Sweden)

    Andrea Gamio Felipa

    2017-08-01

    Full Text Available El artículo tiene como objetivo comparar las diferentes propiedades mecánicas y físicas de 3 sistemas constructivos en tierra tales como el adobe, quincha y champa (Los Putucos, con el propósito de lograr una nueva línea de investigación para las champas y que, puedan ser parte de la implementación de las viviendas rurales que se realizan constantemente en el altiplano peruano. La metodología del trabajo consiste en la comparación de resultados obtenidos de investigaciones previas que muestren que dicho material tiene una resistencia en el tiempo superior al adobe y la quincha, sin embargo, existe ausencia de algunos datos de las champas ya que en la actualidad solo se ha realizado un análisis científico con ensayos sobre este material que serán analizados en el artículo. Es por ello que no se puede determinar en totalidad su eficiencia por la carencia de algunos ensayos, pero si podemos determinar una nueva línea de investigación. Abstract The present article has a purpose to compare the different mechanical and physical properties of 3 construction systems or material in earth, such as Adobe, quincha and champa (The Putucos, with the purpose of achieving a new line of research for champas’ material and can be part of the rural houses implementation which are constantly being carried out in the Peruvian highlands. It has been used the comparison of results obtained from previous research that may show that the material has a higher resistance over time than others, however, there is an absence of some data from the champas and actually exist only one Scientific analysis with test on this material, that is analyzed in the article. It is for this reason that it can’t fully determine its efficiency by lack of some tests, but it can determine a new line of research.

  9. Modelado y control en vuelo estacionario de helicópteros autónomos con cable de fijación a tierra

    Directory of Open Access Journals (Sweden)

    Luis A. Sandino

    2013-10-01

    Full Text Available Resumen: Los helicópteros son conocidos por sus capacidades de vuelo estacionario (maniobra conocida como hovering, despegue y aterrizaje vertical. Sin embargo, la ejecución de la maniobra de hovering puede verse afectada seriamente por perturbaciones como ráfagas de viento. Lo anterior es más significativo en el caso de helicópteros a escala, que son comúnmente adoptados como plataformas para el desarrollo de vehículos aéreos no tripulados. Para solventar las dificultades anteriores y conseguir maniobras de hovering más estables es posible emplear una configuración consistente en un helicóptero autónomo, un cable de fijación a tierra y un sistema de control que ajusta la tensión en el cable. En este artículo, además de incluir los pasos necesarios para obtener un modelo detallado del sistema, se presenta un análisis de los beneficios inherentes a la configuración con cable, así como el esquema general para el diseño de estrategias de control. A manera de ilustración, se incluyen simulaciones comparativas con perturbaciones de viento generadas artificialmente. Abstract: Helicopters are well-known by their hovering and vertical take-off and landing capabilities. However, the performance of the valuable feature of hovering can be seriously affected by external disturbances such as wind effect. The latter could be even more significant when dealing with small-size helicopters, which are commonly adopted as base platforms for developing unmanned aerial vehicles. In order to address the aforementioned instabilities in hovering maneuvers, it is possible to use an augmented configuration that consists of the unmanned helicopter itself, a tether connecting the helicopter to the ground, and a system in charge of adjusting the tether tension. In this paper, in addition to a detailed model of the system, an analysis on the inherent benefits to the augmented configuration is presented, as well as a general scheme for control design. By

  10. The Mysterious Southern Torque

    Science.gov (United States)

    McDowell, M. S.

    2004-05-01

    Something weird happened to twist the southern hemisphere out of alignment with the northern, as evidenced by the positions of the mountain ranges of North and South America, the Atlantic MAR, and the closure of West Africa to North America - all smooth were the torque reversed. What happened, and when, and why? We identify a number of global "cracks" of almost exactly the same length and direction, with some, even more peculiarly, turning the same angle, and proceeding an equal distance in the new direction. The Emperor-Hawaiian chain, the Louisville chain and the west coast of North America, as examples, are essentially parallel. Their northerly legs follow the angle of the axis of orbital ellipse. But then they all make equal 45 degree easterly bends, to 17.5 NW, and continue on, still parallel, for very similar distances. It is the same at the north coast of South America, and the mid-section of the MAR from 46W to 12W. It is the distance from the Cameroons to Kenya, from the south end of the Red Sea to the SE Indian Ridge at the Nema Fracture zone, from west to east of the Nazca plate.What is all this? Coincidence? Seeing things? Researchers have attributed plate motion or hot spot motion or both or absolutely none, to all of the above. Geophysicists have dated the surfaces from Archean to Pleistocene by all possible scientific means, certainly no possible correlation can be made. Yet we postulate the physical reality can be demonstrated. It is so global a phenomenon that it is well beyond what a hot spot or a plate could do. Even a really tremendous impact would have trouble making such precise geometric arrangements. So what is it - perhaps the angle of rotation, or the inertia of northern hemisphere mass above the geoid? And if so, then, what changed it? It would seem that some huge imbalance occurred. Suppose the whole bottom blew out of the southern hemisphere, and the center of mass drastically altered. Suppose some unknown universal force changed our

  11. Analysis, simulation and control of electromagnetic transients in gas insulated substations in SF6 by means of grounding grid; Analisis, simulacion y control de transitorios electromagneticos en subestaciones aisladas en SF6 por medio de redes de tierra

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Martinez, Gaston

    2007-12-15

    operaciones de maniobra, originando el sobrevoltaje transitorio ultra rapido (VFTO) y el voltaje transitorio encapsulado (TEV). Esta investigacion se centra en disminuir la magnitud del VFTO y el TEV a traves del diseno y rediseno de redes de tierra para subestaciones aisladas en gas. El objetivo de este trabajo es el de disenar una red de tierra para una subestacion aerea y redisenarla para una subestacion GIS utilizando el modelo detallado de la subestacion en SF6 interconectado con la red de tierra aerea hasta conseguir, a traves de la adicion metodologica de varillas de tierra, disminuir el VFTO y el TVE dentro del GIS. Los resultados de la simulacion muestran que la red de tierra disenada permite disminuir considerablemente la magnitud del VFTO; sin embargo, este diseno no consigue atenuar adecuadamente la magnitud del TEV.

  12. Multiplicative properties of quantum channels

    Science.gov (United States)

    Rahaman, Mizanur

    2017-08-01

    In this paper, we study the multiplicative behaviour of quantum channels, mathematically described by trace preserving, completely positive maps on matrix algebras. It turns out that the multiplicative domain of a unital quantum channel has a close connection to its spectral properties. A structure theorem (theorem 2.5), which reveals the automorphic property of an arbitrary unital quantum channel on a subalgebra, is presented. Various classes of quantum channels (irreducible, primitive, etc) are then analysed in terms of this stabilising subalgebra. The notion of the multiplicative index of a unital quantum channel is introduced, which measures the number of times a unital channel needs to be composed with itself for the multiplicative algebra to stabilise. We show that the maps that have trivial multiplicative domains are dense in completely bounded norm topology in the set of all unital completely positive maps. Some applications in quantum information theory are discussed.

  13. THE SOUTHERN AEGEAN SYSTEM

    Directory of Open Access Journals (Sweden)

    Ina Berg

    2015-08-01

    Full Text Available Although world-systems theory was originally formulated with our modern economic system in mind (Wallerstein 1974, it was not long before archaeologists began to apply it to ancient societies. Archaeologists and world-system theorists alike both argued that Wallerstein had disregarded evidence of interconnected, hierarchical systems in prehistoric times (Schneider 1977; Chase-Dunn & Hall 1991, 1997; Kardulias 1999a. Pailes and Whitecotton (1979 were among the first to modify world-systems theory for use in pre-capitalist settings. Since then many archaeologists have looked at data and regions with a world-systems perspective in mind (e.g. Champion 1989; Bilde et al. 1993; Rowlands & Larsen 1987; Kardulias 1999a. Some have attempted to map Wallerstein's theory directly onto prehistory (Kohl 1979; Whitecotton & Pailes 1986; Ekholm & Friedman 1982. Others have found the world systems model heuristically useful but lacking the analytical power needed for their prehistoric cases (Blanton et al. 1981; Upham 1982; Plog 1983; Alcock 1993. Building on the assumption that ancient societies were not qualitatively, but only quantitatively, different from modern capitalist ones (Schneider 1977; Sherratt & Sherratt 1991, this study applies world systems theory to the Southern Aegean during the Middle and Late Bronze Age (ca. 2000-1550 BC.

  14. Simulated behavior of drilling fluid discharges off Southern California

    International Nuclear Information System (INIS)

    Brandsma, M.G.; Kolpack, R.L.; Dickey, T.D.; Balcom, B.J.

    1990-01-01

    This paper focuses on the computer-simulated short-term behavior of drilling-fluid solids from the time of release to initial deposition on the ocean bottom. The geographic areas of primary interest were the Santa Barbara Channel and Point Conception regions off southern California. Simulations (53) were conducted for water depths ranging from 30 to 750 m. Oceanographic parameters for several representative oceanic conditions were obtained from available field measurements in the area. Characteristics of representative drilling-fluid solids were formulated from information supplied by several offshore operators and by laboratory analyses of samples

  15. The Pleistocene rivers of the English Channel region

    Science.gov (United States)

    Antoine, Pierre; Coutard, Jean-Pierre; Gibbard, Philip; Hallegouet, Bernard; Lautridou, Jean-Pierre; Ozouf, Jean-Claude

    2003-02-01

    The Pleistocene history of river systems that enter the English Channel from northern France and southern England is reviewed. During periods of low sea-level (cold stages) these streams were tributaries of the Channel River. In southern England the largest, the River Solent, is an axial stream that has drained the Hampshire Basin from the Early Pleistocene or late Pliocene. Other streams of southern England may be of similar antiquity but their records are generally short and their sedimentary history have been destroyed, as in northern Brittany, by coastal erosion and valley deepening as a consequence of tectonic uplift. In northern France, the Seine and Somme rivers have very well developed terrace systems recording incision that began at around 1 Ma. The uplift rate, deduced from the study of these terrace systems, is of 55 to 60 m myr-1 since the end of the Early Pleistocene. Generally the facies and sedimentary structures indicate that the bulk of the deposits in these rivers accumulated in braided river environments under periglacial climates in all the area around the Channel. Evolution of the rivers reflects their responses to climatic change, local geological structure and long-term tectonic activity. In this context the Middle Somme valley is characterised by a regular pattern in which incision occurs at the beginning of each glacial period within a general background of uplift. Nevertheless the response of the different rivers to climatic variations, uplift and sea-level changes is complex and variable according to the different parts of the river courses.

  16. Upgrading a marketing channels role

    Directory of Open Access Journals (Sweden)

    Tišma-Borota Ankica

    2002-01-01

    Full Text Available As one of the marketing mix instruments, marketing channels were usually behind other instruments (product, price and promotion. Many companies regarded marketing channels as something that was 'left' after more important strategies of price, product and promotion were created. In recent past, things have changed and marketing channels became more interesting for research. This change came as a result of change in global market functioning especially in competitive advantage, distributors' strength and increasing technology.

  17. Single-channel kinetics of BK (Slo1 channels

    Directory of Open Access Journals (Sweden)

    Yanyan eGeng

    2015-01-01

    Full Text Available Single-channel kinetics has proven a powerful tool to reveal information about the gating mechanisms that control the opening and closing of ion channels. This introductory review focuses on the gating of large conductance Ca2+- and voltage-activated K+ (BK or Slo1 channels at the single-channel level. It starts with single-channel current records and progresses to presentation and analysis of single-channel data and the development of gating mechanisms in terms of discrete state Markov (DSM models. The DSM models are formulated in terms of the tetrameric modular structure of BK channels, consisting of a central transmembrane pore-gate domain (PGD attached to four surrounding transmembrane voltage sensing domains (VSD and a large intracellular cytosolic domain (CTD, also referred to as the gating ring. The modular structure and data analysis shows that the Ca2+ and voltage dependent gating considered separately can each be approximated by 10-state two-tiered models with 5 closed states on the upper tier and 5 open states on the lower tier. The modular structure and joint Ca2+ and voltage dependent gating are consistent with a 50 state two-tiered model with 25 closed states on the upper tier and 25 open states on the lower tier. Adding an additional tier of brief closed (flicker states to the 10-state or 50-state models improved the description of the gating. For fixed experimental conditions a channel would gate in only a subset of the potential number of states. The detected number of states and the correlations between adjacent interval durations are consistent with the tiered models. The examined models can account for the single-channel kinetics and the bursting behavior of gating. Ca2+ and voltage activate BK channels by predominantly increasing the effective opening rate of the channel with a smaller decrease in the effective closing rate. Ca2+ and depolarization thus activate by mainly destabilizing the closed states.

  18. Invertebrate diversity in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile displays mean invertebrate diversity within 5 minute grid cells. The Shannon Index of diversity was calculated from Southern California Coastal Water...

  19. Southern African Business Review: Submissions

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited journal of the College of Economic and Management Sciences of the University of South Africa. ... the right to make minor editorial adjustments without consulting the author.

  20. The Holocene Great Belt connection to the southern Kattegat, Scandinavia

    DEFF Research Database (Denmark)

    Bendixen, Carina; Jensen, Jørn Bo; Boldreel, Lars Ole

    2017-01-01

    Late- and postglacial geological evolution of the southern Kattegat connection to the Great Belt was investigated from high-resolution seismic data and radiocarbon-dated sediment cores in order to elucidate the Ancylus Lake drainage/Littorina Sea transgression. It was found that glacial deposits...... form the acoustic basement and are covered by Lateglacial (LG) marine sediments and postglacial (PG; Holocene) material. The LG deposits form a highstand systems tract, whereas the PG deposits cover a full depositional sequence, consisting of a lowstand systems tract (PG I), transgressive systems tract...... (PG II; subdivided into three parasequences) and finally a highstand systems tract (PG III). PG I sand deposits (11.7–10.8 cal. ka BP) are found in a major western channel and in a secondary eastern channel. PG II (10.8–9.8 cal. ka BP) consists of estuarine and coastal deposits linked to an estuary...

  1. Human responses to Middle Holocene climate change on California's Channel Islands

    Science.gov (United States)

    Kennett, Douglas J.; Kennett, James P.; Erlandson, Jon M.; Cannariato, Kevin G.

    2007-02-01

    High-resolution archaeological and paleoenvironmental records from California's Channel Islands provide a unique opportunity to examine potential relationships between climatically induced environmental changes and prehistoric human behavioral responses. Available climate records in western North America (7-3.8 ka) indicate a severe dry interval between 6.3 and 4.8 ka embedded within a generally warm and dry Middle Holocene. Very dry conditions in western North America between 6.3 and 4.8 ka correlate with cold to moderate sea-surface temperatures (SST) along the southern California Coast evident in Ocean Drilling Program (ODP) Core 893A/B (Santa Barbara Basin). An episode of inferred high marine productivity between 6.3 and 5.8 ka corresponds with the coldest estimated SSTs of the Middle Holocene, otherwise marked by warm/low productivity marine conditions (7.5-3.8 ka). The impact of this severe aridity on humans was different between the northern and southern Channel Islands, apparently related to degree of island isolation, size and productivity of islands relative to population, fresh water availability, and on-going social relationships between island and continental populations. Northern Channel Islanders seem to have been largely unaffected by this severe arid phase. In contrast, cultural changes on the southern Channel Islands were likely influenced by the climatically induced environmental changes. We suggest that productive marine conditions coupled with a dry terrestrial climate between 6.3 and 5.8 ka stimulated early village development and intensified fishing on the more remote southern islands. Contact with people on the adjacent southern California Coast increased during this time with increased participation in a down-the-line trade network extending into the western Great Basin and central Oregon. Genetic similarities between Middle Holocene burial populations on the southern Channel Islands and modern California Uto-Aztecan populations suggest

  2. UMTS Common Channel Sensitivity Analysis

    DEFF Research Database (Denmark)

    Pratas, Nuno; Rodrigues, António; Santos, Frederico

    2006-01-01

    and as such it is necessary that both channels be available across the cell radius. This requirement makes the choice of the transmission parameters a fundamental one. This paper presents a sensitivity analysis regarding the transmission parameters of two UMTS common channels: RACH and FACH. Optimization of these channels...... is performed and values for the key transmission parameters in both common channels are obtained. On RACH these parameters are the message to preamble offset, the initial SIR target and the preamble power step while on FACH it is the transmission power offset....

  3. Demystifying Mechanosensitive Piezo Ion Channels.

    Science.gov (United States)

    Xu, X Z Shawn

    2016-06-01

    Mechanosensitive channels mediate touch, hearing, proprioception, and blood pressure regulation. Piezo proteins, including Piezo1 and Piezo2, represent a new class of mechanosensitive channels that have been reported to play key roles in most, if not all, of these modalities. The structural architecture and molecular mechanisms by which Piezos act as mechanosensitive channels, however, remain mysterious. Two new studies have now provided critical insights into the atomic structure and molecular basis of the ion permeation and mechano-gating properties of the Piezo1 channel.

  4. Defect Distributions in Channeling Experiments

    DEFF Research Database (Denmark)

    Andersen, Hans Henrik; Sigmund, P.

    1965-01-01

    A simple collision model allows to calculate energy losses of perfectly channeled particles. The maximum energy loss is related in a simple way to the displacement energy of lattice atoms perpendicular to the channel. From that, one obtains rather definite predictions on the possibility...... of radiation damage by channeled particles. As an application, one gets a necessary criterion for the occurence of super tails in channeling experiments. The theory involves some assumptions on the behaviour of Born-Mayer potentials which are verified by comparison to experimental displacement energies....

  5. Utilization of the southern pines

    Energy Technology Data Exchange (ETDEWEB)

    Koch, P

    1972-01-01

    After several years out of print, this book is again available. The two-volume reference characterizes the southern pine tree as raw material and describes the process by which it is converted to use. All 10 species are considered. The book is addressed primarily to the incoming generation of researchers and industrial managers in the southern pine industry. Foremen, superintendents, quality control personnel, wood procurement men, forest managers, extension workers, professors, and students of wood technology should find the handbook of value.

  6. Energy Trade in Southern Africa

    International Nuclear Information System (INIS)

    Holland, W F.

    1996-01-01

    This document deals with possible energy growth in Southern African countries. This region possesses substantial energy resources (including fossil fuels), but because of political instability, government intervention, financial paralysis and lack of adequate transportation infrastructure, this region faces problems in satisfying energy needs. Two key international actions, namely the South African Development Community (SADC) Energy Protocol and the Southern African Power Pool (SAPP) are expected to enhance energy trade and promote economic development. (TEC)

  7. Characteristics of southern California atmospheric rivers

    Science.gov (United States)

    Harris, Sarah M.; Carvalho, Leila M. V.

    2018-05-01

    Atmospheric rivers (ARs) are channels of high water vapor flux that transport moisture from low to higher latitudes on synoptic timescales. In areas of topographical variability, ARs may lead to high-intensity precipitation due to orographic forcing. ARs landfalling along North America's west coast are linked to extreme events including those leading to flooding and landslides. In southern California (SCA), proper AR forecasting is important for regional water resources as well as hazard mitigation and as the area's annual precipitation totals occur from relatively few storms per season, any changes to storm frequency and/or intensity may have dramatic consequences. Yet, as most regional AR studies focus on the Pacific Northwest, there is little information about SCA ARs. We develop an algorithm to identify ARs landfalling on North America's west coast between 1979 and 2013 within total precipitable water reanalysis fields. ARs are then categorized according to landfall region. To determine and differentiate the characteristics and spatial distributions of ARs affecting these areas, we examine lag composites of various atmospheric variables for each landfall region. SCA ARs differ from ARs landfalling farther north in the days prior to landfall with the position and amplitude of a trough offshore from the Asian continent and ridge over Alaska, as well as the displacement and eastward extension of the jet core that potentially guides AR moisture southwards. The relationships between AR landfalls and the El Niño/Southern Oscillation (ENSO), the Madden-Julian Oscillation (MJO), and the Pacific/North American Teleconnection Pattern (PNA) are also investigated.

  8. Preservation of meandering river channels in uniformly aggrading channel belts

    NARCIS (Netherlands)

    Lageweg, W.I. van de; Schuurman, F.; Cohen, K.M.; Dijk, W.M. van; Shimizu, Y.; Kleinhans, M.G.

    2016-01-01

    Channel belt deposits from meandering river systems commonly display an internal architecture of stacked depositional features with scoured basal contacts due to channel and bedform migration across a range of scales. Recognition and correct interpretation of these bounding surfaces is essential to

  9. MONETARY TRANSMISSION CHANNELS IN ROMANIA – THE CREDIT CHANNEL

    Directory of Open Access Journals (Sweden)

    Magdalena RĂDULESCU

    2009-12-01

    Full Text Available The theoretical – intuitive analysis applied to the segment of monetary transmission evidences the fact that forming the traditional monetary impulses transmission channels are in a starting phase due to the long financial non – intermediary process which Romanian economy had known. In these conditions, the exchange rate channel, and also NBR currency purchases was, for a long time, an important way through which monetary authorities actions influenced macro economical behaviors. But starting with 2000, it is observed a credit channel reactivation and, especially, interest rate channel. Anyhow, the credit channel continues to be undermined by the existence of liquidity surplus within the system, by the phenomena of substitution of national currency credit with currency credits, and also moral hazardous displays. Albeit some of these phenomena also affect the interest rate channel, its role in sending monetary policy impulses is in a continuous progress. Apparently, it acts by way of nominal interest rates, their real level seeming less relevant. Once with remaking the two traditional channels, the companies and households balance is configured and consolidated, which shall potentate in the future the efficiency of the monetary policy. This paper analyses the credit channel in Romania, through an unrestricted VAR analysis.. It shows the responses of exchange rate, inflation rate, GDP, interest rate, imports and exports to a shock on non-governmental credit

  10. ZnO-channel thin-film transistors: Channel mobility

    International Nuclear Information System (INIS)

    Hoffman, R.L.

    2004-01-01

    ZnO-channel thin-film transistor (TFT) test structures are fabricated using a bottom-gate structure on thermally oxidized Si; ZnO is deposited via RF sputtering from an oxide target, with an unheated substrate. Electrical characteristics are evaluated, with particular attention given to the extraction and interpretation of transistor channel mobility. ZnO-channel TFT mobility exhibits severe deviation from that assumed by ideal TFT models; mobility extraction methodology must accordingly be recast so as to provide useful insight into device operation. Two mobility metrics, μ avg and μ inc , are developed and proposed as relevant tools in the characterization of nonideal TFTs. These mobility metrics are employed to characterize the ZnO-channel TFTs reported herein; values for μ inc as high as 25 cm2/V s are measured, comprising a substantial increase in ZnO-channel TFT mobility as compared to previously reported performance for such devices

  11. URBAN WATERSHED STUDIES IN SOUTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    Cristiano Poleto

    2007-12-01

    Full Text Available One of the greatest problems observed in Brazilian urban watersheds are concerned to the amount of solid residues, domestic sewerage and sediments that are disposed in the rivers and streams that drain those areas. This project aims to present these problems through a study of case taken in an urban watershed in Porto Alegre city, Southern Brazil. For this study, different procedures were used, such as field surveys, interviews with the inhabitants, satellite images, sediment samples, flow measures and morphology assessment of part of the local fluvial system to check the degree of instability of the channel. In 2005, it was verified that 42.57% of the watershed was impermeable, considering the paved streets, the residential and commercial buildings and stone pavements. As there was no sewer treatment, most of this sewerage was directly disposed into the stream and the TOC has reached 20% (m/m. Moreover, the occupation of riparian areas, a great amount of soil exposed in the watershed, the nonpaved streets and a great volume of solid residues were causing the instability in the channel, silting the stream bed. The metals (Zn, Pb and Cr selected for this study are most frequently found in high concentrations in urban areas. The results suggest the occurrence of a high enrichment of the fluvial sediment by these metals. The concentrations of these elements vary temporally during storms due to the input of impervious area runoff containing high concentration of elements associated to vehicular traffic and other anthropogenic activities. Then, it is possible to conclude that the contamination of the urban watershed is reflected in the results obtained in the fluvial suspended sediments.

  12. URBAN WATERSHED STUDIES IN SOUTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    Cristiano Poleto

    2007-01-01

    Full Text Available One of the greatest problems observed in Brazilian urban watersheds are concerned to the amount of solid residues, domestic sewerage and sediments that are disposed in the rivers and streams that drain those areas. This project aims to present these problems through a study of case taken in an urban watershed in Porto Alegre city, Southern Brazil. For this study, different procedures were used, such as field surveys, interviews with the inhabitants, satellite images, sediment samples, flow measures and morphology assessment of part of the local fluvial system to check the degree of instability of the channel. In 2005, it was verified that 42.57% of the watershed was impermeable, considering the paved streets, the residential and commercial buildings and stone pavements. As there was no sewer treatment, most of this sewerage was directly disposed into the stream and the TOC has reached 20% (m/m. Moreover, the occupation of riparian areas, a great amount of soil exposed in the watershed, the nonpaved streets and a great volume of solid residues were causing the instability in the channel, silting the stream bed. The metals (Zn, Pb and Cr selected for this study are most frequently found in high concentrations in urban areas. The results suggest the occurrence of a high enrichment of the fluvial sediment by these metals. The concentrations of these elements vary temporally during storms due to the input of impervious area runoff containing high concentration of elements associated to vehicular traffic and other anthropogenic activities. Then, it is possible to conclude that the contamination of the urban watershed is reflected in the results obtained in the fluvial suspended sediments.

  13. El pulso de la Tierra

    OpenAIRE

    Instituto Geofísico del Perú

    2010-01-01

    Trata sobre la sismología y geodesia espacial aplicada a nuestro país. El BCRP agradece al IGP el haber compartido este artículo aparecido en la memoria institucional 2009, Presente y Futuro, el que contribuirá a ampliar nuestro conocimiento sobre el origen y comportamiento de los terremotos.

  14. A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation

    International Nuclear Information System (INIS)

    Brasso, Rebecka L.; Chiaradia, André; Polito, Michael J.; Raya Rey, Andrea; Emslie, Steven D.

    2015-01-01

    Highlights: • Mercury concentrations documented for 10 species of penguins (26 breeding populations). • Mercury concentrations ⩽2.00 ppm in feathers from 18/26 penguin populations. • Trophic level calculations revealed source of population-level variation in mercury. • First documentation of geographic mercury ‘hotspots’ for penguin populations. - Abstract: The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability

  15. A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation.

    Science.gov (United States)

    Brasso, Rebecka L; Chiaradia, André; Polito, Michael J; Raya Rey, Andrea; Emslie, Steven D

    2015-08-15

    The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic 'hot spots' of mercury availability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. An improved channel assessment scheme

    KAUST Repository

    Bader, Ahmed

    2014-01-01

    A source node in a multihop network determines whether to transmit in a channel based on whether the channel is occupied by a packet transmission with a large number of relays; whether the source node is in the data tones back-off zone; and the source node is in the busy tone back-off zone.

  17. Quantum communication under channel uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Noetzel, Janis Christian Gregor

    2012-09-06

    This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

  18. Perceived quality of channel zapping

    NARCIS (Netherlands)

    Kooij, R.E.; Ahmed, K.; Brunnström, K.

    2006-01-01

    The end user experience of service quality is critical to the success of a service provider's IPTV deployment program. A key element involved in validating IPTV quality of experience (QoE) is how quickly and reliably users can change TV channels, often referred to as channel zapping. Currently there

  19. Channel's Concurrence and Quantum Teleportation

    Institute of Scientific and Technical Information of China (English)

    LING Yin-Sheng

    2005-01-01

    Concurrence can measure the entanglement property of a system. If the channel is a pure state, positive concurrence state can afford the good performance in the teleportation process. If the channel ia a mixed state, positive concurrence state cannot assure the good performance in the teleportation. The conditions of the positive concurrence and the quantum teleportation in the Heisenberg spin ring is derived.

  20. An improved channel assessment scheme

    KAUST Repository

    Bader, Ahmed

    2014-05-01

    A source node in a multihop network determines whether to transmit in a channel based on whether the channel is occupied by a packet transmission with a large number of relays; whether the source node is in the data tones back-off zone; and the source node is in the busy tone back-off zone.

  1. 'Que memoria de onbre non es en contrario'. Usurpación de tierras y manipulación del pasado en la Castilla urbana del siglo 'Que memoria de onbre non es en contrario'. Usurpación de tierras y manipulación del pasado en la Castilla urbana del siglo XV

    Directory of Open Access Journals (Sweden)

    José Antonio JARA FUENTE

    2009-12-01

    Full Text Available RESUMEN: En el presente trabajo, se abordan las estrategias elaboradas por distintos actores sociales para segregar de la jurisdicción del concejo de Cuenca espacios que, en última instancia, debían haber dado lugar a la creación de señoríos. Centrándome en el proceso que enfrentó a Cuenca con un noble local, Alonso Carrillo, pretendo mostrar cómo se desarrolló dicho proceso a lo largo del siglo XV, así como los discursos elaborados para justificar y legitimar aquellos procesos de apropiación. Finalmente, analizo cómo se enfrentó el concejo de Cuenca a las segregaciones de tierras de su jurisdicción, y las diversas estrategias que desarrolló para oponerse, con éxito, a ese proceso.ABSTRACT: This paper deals with the strategies developed by several social actors in order to segregate land from Cuenca's jurisdictional hinterland and to build, on this space, their own states. Focusing my study on a legal process opposing the city of Cuenca and a local nobleman, Alonso Carrillo, I will try to show the development of that process along the fifteenthcentury as weU as the discourses devised to justify and legitimise those processes of land seizure. Innally, I analyse the opposition raised by the city of Cuenca against the segregation of lands from its hinterland and the different strategies it developed in order to successfully oppose to that process.

  2. Regional bankfull-channel dimensions of non-urban wadeable streams in Indiana

    Science.gov (United States)

    Robinson, Bret A.

    2013-01-01

    During floods, damage to properties and community infrastructure may result from inundation and the processes of erosion. The damages imparted by erosion are collectively termed the fluvial erosion hazard (FEH), and the Indiana Silver Jackets Multi-agency Hazard Mitigation Taskforce is supporting a program to build tools that will assist Indiana property owners and communities with FEH-mitigation efforts. As part of that program, regional channel-dimension relations are identified for non-urban wadeable streams in Indiana. With a site-selection process that targeted the three largest physiographic regions of the state, field work was completed to measure channel-dimension and channel-geometry characteristics across Indiana. In total, 82 sites were identified for data collection; 25 in the Northern Moraine and Lake region, 31 in the Central Till Plain region, and 26 in the Southern Hills and Lowlands region. Following well established methods, for each data-collection site, effort was applied to identify bankfull stage, determine bankfull-channel dimensions, and document channel-geometry characteristics that allowed for determinations of channel classification. In this report, regional bankfull-channel dimension results are presented as a combination of plots and regression equations that identify the relations between drainage area and the bankfull-channel dimensions of width, mean depth, and cross-sectional area. This investigation found that the channel-dimension data support independent relations for each of the three physiographic regions noted above. Furthermore, these relations show that, for any given drainage area, northern Indiana channels have the smallest predicted dimensions, southern Indiana channels have the largest predicted dimensions, and central Indiana channels are intermediate in their predicted dimensions. When considering the suite of variables that influence bankfull-channel dimensions, it appears that contrasting runoff characteristics

  3. Decreasing vortex flux in channels

    International Nuclear Information System (INIS)

    Migaj, V.K.; Nosova, I.S.

    1979-01-01

    A new method for reducing vortex flow losses in power plant channels is suggested. The method is based on vortex splitting in vortex flow areas with transverse barriers placed on the channel walls. The upper barrier ends are at the level of the upper boundary of the vortex area and don't protrude to the active flow beyond this boundary. The effectiveness of the method suggested is illustrated taking as an example the investigation of square and flat channels with abrupt widening in one plane, diffusers with widening in one plane, or a rectangualr bend. It is shown that splitting the vortex areas with transverse barriers in the channels results in reduction of hydraulic losses by 10-25%. The above method is characteristic of an extreme simplicity, its application doesn't require changes in the channel shape nor installation of any devices in the flow

  4. Channel box dimension measuring method

    International Nuclear Information System (INIS)

    Oshima, Hirotake; Jo, Hiroto.

    1994-01-01

    The present invention provides a method for measuring the entire length of a channel box of a fuel assembly of a BWR type reactor. Namely, four sensors are used as one set that generate ultrasonic waves from oblique upper portion, oblique lower portion, upper portion and lower portion of the channel box respectively. The distances between the four sensors and each of the portions of the channel box are measured respectively for both of a reference member and a member to be measured. The entire length of the channel box is measured by calculating the measured values and the angles of the obliquely disposed sensors according to a predetermined formula. According to the method of the present invention, the inclination of the channel box to be measured can be corrected. In addition, accuracy of the measurement is improved and the measuring time is saved as well as the measuring device and operation can be simplified. (I.S.)

  5. Marketing channels and competitive advantage

    Directory of Open Access Journals (Sweden)

    Jovičić Dragoljub

    2005-01-01

    Full Text Available Issue that can already be seen and will be very clear in the future is that the central problem in the market of tube caps will not be the product or the price or promotion, but marketing channels. Therefore, the competitive advantage will most probably be built on marketing channels and not the production - as it has been so far, so, the questions of choice functioning and modification of marketing channels, as well as selection of the most appropriate members of channels will become more and more important. Accordingly, it may freely be said that the choice, i.e. the movement of marketing channels represents one of the strategic decisions which has to be made by a company management and which will subsequently very significantly influence the functioning and efficacy of not only the system of distribution, but also the entire business transactions.

  6. Southern Peru desert shattered by the great 2001 earthquake: Implications for paleoseismic and paleo-El Niño–Southern Oscillation records

    OpenAIRE

    Keefer, David K.; Moseley, Michael E.

    2004-01-01

    In the desert region around the coastal city of Ilo, the great southern Peru earthquake of June 23, 2001 (8.2–8.4 moment magnitude), produced intense and widespread ground-failure effects. These effects included abundant landslides, pervasive ground cracking, microfracturing of surficial hillslope materials, collapse of drainage banks over long stretches, widening of hillside rills, and lengthening of first-order tributary channels. We have coined the term “shattered landscape” to describe th...

  7. La usurpación de tierras comunales y baldíos en Guadalajara durante la segunda mitad del siglo XV = The Illegal Appropriation of Communal Lands in Guadalajara in the Second Half of the Fifteenth Century

    Directory of Open Access Journals (Sweden)

    Javier Plaza de Agustín

    2015-06-01

    Full Text Available La ciudad de Guadalajara, desde su incorporación a la corona castellana, se constituyó como cabeza de un amplio territorio de realengo sobre el que ejercía su jurisdicción. Este alfoz se componía de considerables extensiones de tierras de uso comunal, principalmente pastos para el ganado y bosque del que se obtenía madera y caza, que constituían una de las bases económicas de la ciudad y las aldeas de su entorno. Durante la Baja Edad Media, y específicamente en la segunda mitad del siglo XV, estas tierras sufrieron el expolio de todo tipo de usurpadores contra los que el concejo trató de luchar, bien utilizando sus propios medios o bien mediante la intervención de la monarquía. Este artículo tratará de estudiar la situación de las tierras públicas de la ciudad y conocer la identidad de los usurpadores, para lo cual se ha recurrido principalmente al estudio de la documentación conservada acerca de los diversos conflictos asociados a este fenómeno.Since its incorporation in the kingdom of Castile, Guadalajara became the head of an extensive territory under the direct rule of the king. Within this territory, there were large tracts of communal lands, mainly pasture for cattle and forests that provided wood and game, one of the main economic sources for the city and its surrounding villages. In the late Middle Ages, and specifically in the second half of the fifteenth century, these lands suffered illegal appropriation by all kinds of occupiers against which the local council tried to fight either by means of its own resources or through royal intervention. This article aims to study the location of the public lands of the city and to identify those responsible for their encroachment. For this purpose, we have mainly focussed on the extant documentation concerning various conflicts associated with this phenomenon.

  8. PROTOTIPO DE UN SISTEMA INTEGRADO DIGITAL PARA LA CLASIFICACIÓN DE COBERTURAS Y USOS DE LA TIERRA A NIVEL DE FINCA BANANERA DIGITAL INTEGRATED SYSTEM FOR THE CLASSIFICATION OF LAND COVER AND USE TO BANANA FARM LEVEL

    Directory of Open Access Journals (Sweden)

    Darío Antonio Castañeda Sánchez

    2006-06-01

    Full Text Available Se desarrolló un prototipo de un sistema integral para la clasificación de coberturas y usos de la tierra, aplicable a los sistemas bananeros. Este se basó en dos criterios, el de la participación comunitaria y el del sensoramiento remoto. El primero se fundamenta en la incorporación del conocimiento que tiene la comunidad de su entorno mediante talleres y cartografía social, el segundo propone el empleo de herramientas tecnológicas de bajo costo para el levantamiento de las coberturas y uso de la tierra, como la adquisición de fotografías aéreas de baja altitud usando un sistema conformado por una cometa o globo, un equipo para la adquisición de las imágenes y un equipo de control en tierra. La propuesta fue aplicada mediante un estudio de caso en una finca bananera ubicada en la región de Urabá (Colombia. El análisis de imágenes permitió la agrupación de las coberturas en clases o grupos y con el aporte de la participación comunitaria se describieron los usos para cada cobertura. Finalmente se hizo un análisis de las normas ambientales relacionadas con la distribución espacial de las coberturas, hallándose por ejemplo áreas de retiro del cultivo respecto a recursos o zonas vulnerables así como su cumplimiento o no de la normatividad.An integrated system was developed for the classification of land cover and use that is applicable to banana systems. It was based on two criteria; community participation and remote sensing. The former is based upon incorporation of the knowledge that the community has regarding its surroundings through workshops and social cartography; the latter proposes the use of low cost technological tools for establishing land covers and uses, such as acquiring low altitude aerial photographs using a system comprised of a kite or balloon, equipment for image acquisition, and ground based control equipment. The proposal was applied through a case study in a banana plantation located in the Urab

  9. Methods of channeling simulation

    International Nuclear Information System (INIS)

    Barrett, J.H.

    1989-06-01

    Many computer simulation programs have been used to interpret experiments almost since the first channeling measurements were made. Certain aspects of these programs are important in how accurately they simulate ions in crystals; among these are the manner in which the structure of the crystal is incorporated, how any quantity of interest is computed, what ion-atom potential is used, how deflections are computed from the potential, incorporation of thermal vibrations of the lattice atoms, correlations of thermal vibrations, and form of stopping power. Other aspects of the programs are included to improve the speed; among these are table lookup, importance sampling, and the multiparameter method. It is desirable for programs to facilitate incorporation of special features of interest in special situations; examples are relaxations and enhanced vibrations of surface atoms, easy substitution of an alternate potential for comparison, change of row directions from layer to layer in strained-layer lattices, and different vibration amplitudes for substitutional solute or impurity atoms. Ways of implementing all of these aspects and features and the consequences of them will be discussed. 30 refs., 3 figs

  10. Based on Channel Characteristics

    Directory of Open Access Journals (Sweden)

    Zhuo Hao

    2013-01-01

    Full Text Available A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

  11. Buscando luz en la tierra: bajo las bóvedas del Baño Real del Palacio de Comares

    Directory of Open Access Journals (Sweden)

    Miguel Guitart

    2015-05-01

    Full Text Available A lo largo de la cultura islámica se han producido soluciones espaciales de enorme riqueza arquitectónica y refinamiento estético, que no necesariamente material. El baño o hammam es con probabilidad uno de los más singulares. Procedente de las pautas establecidas por las termas romanas, estos baños se convirtieron en salas fundamentales de la vida social del mundo islámico. Cabría destacar en España ejem­plos tan relevantes como los Baños de Alí en Jaén del siglo X, el Bañuelo del Albaicín en Granada del siglo XI, o el más representativo de todos ellos, el Baño de Comares en el palacio-fortaleza de la Alhambra del siglo XIV. Todos ellos se caracterizan por sus bóvedas perforadas a modo de grandes moldes de luz que, si bien cumplían una misión funcional como la de introducir luz natural y regular la temperatura y la cantidad de vapor de agua en el interior, también transformaban por completo el espacio por medio de la luz y las sombras, haciendo de estas salas lugares muy característicos de su propia cultura. El hammam del Baño del Palacio de Comares, también conocido como Baño Real por haber sido de uso particular de los Reyes Católicos, se remonta a la época de Yusuf I (1333-1354. El Baño Real o de Comares constituye uno de los espacios de mayor interés dentro del conjunto de la Alhambra, con uno de los hammam en mejor estado de conservación hasta la fecha en Occidente, prácticamente íntegro a pesar de algunas modificaciones estructurales y un mantenimiento más testimonial que funcional. Podríamos asumir que el baño del Palacio de Comares se experimenta desde una doble estrategia: la del estatismo del baño como espacio consolidado y no cam­biante, relacionado por su masa y la condición original de la tierra de la que surge y sobre la que se asienta, que se infunde de vida al ser intervenida por la luz esce­nográfica del filtro de sus bóvedas; y la del movimiento establecido, del recorrido del visitante

  12. Mestizaje y nacionalismo en la tierra en armas de Dávalos / Serrano y en algunos ensayos de Juan Carlos Dávalos.

    Directory of Open Access Journals (Sweden)

    Elisa Moyano

    2003-01-01

    Full Text Available El presente trabajo realiza un análisis de La tierra en armas, Los gauchos y “Gauchos y collas” en los que algunos personajes se presentan elaborados desde el paradigma del mestizaje. Los textos no constituyen descripciones del mestizo, del mestizaje o del proceso de su constitución (aunque los ensayos hacen pequeños aportes en este sentido como las realizadas por Uslar Pietri o por Fernando Ortiz. Se trata (y ésta es nuestra hipótesis de textos donde se construyen mestizos ideales para proponerlos como figuras de identificación en el marco de una doctrina política: el nacionalismo. El análisis se hizo siguiendo el modelo teórico-metodológico que Cornejo Polar utiliza para “desenmascarar” el hispanismo de la tesis de Riva Agüero sobre el Inca Garcilaso. A partir de comparaciones con las figuras mestizas construidas en otros textos, se encontraron similitudes con las de Riva Agüero con lo que se pensó en una posible raíz andina de los textos davalianos; pero se llegó a la conclusión de que éstos: 1.- están informados por un nacionalismo fuertemente hispanista a la manera de Manuel Gálvez y no al modo helenizante de Lugones 2.- están atravesados por un tenaz antiindigenismo, en las antípodas de una posición como la de Ricardo Rojas que daba importancia también a la vertiente indígena del mestizaje. Finalmente y a manera de conclusión se discute si, a comienzos del siglo XXI, tiene sentido “denunciar” hispanismo. O si, realizada en tantos ensayos la ponderación del mestizaje como característica de Hispanoamérica (aún cuando se haga sobresalir la vertiente hispana del mismo no sería preferible: 1.- ubicar los textos en sus condiciones productivas; 2.- preguntar por el lugar enunciativo desde dónde se “desenmascara” el hispanismo; 3.- ver si en los enunciados no se está estigmatizando todavía a España que —a diferencia de otras potencias imperiales— hizo posible la mezcla, y finalmente 4.- observar si, al

  13. Treasures of the Southern Sky

    CERN Document Server

    Gendler, Robert; Malin, David

    2011-01-01

    In these pages, the reader can follow the engaging saga of astronomical exploration in the southern hemisphere, in a modern merger of aesthetics, science, and a story of human endeavor. This book is truly a celebration of southern skies.  Jerry Bonnell, Editor - Astronomy Picture of the Day The southern sky became accessible to scientific scrutiny only a few centuries ago, after the first European explorers ventured south of the equator. Modern observing and imaging techniques have since revealed what seems like a new Universe, previously hidden below the horizon, a fresh astronomical bounty of beauty and knowledge uniquely different from the northern sky. The authors have crafted a book that brings this hidden Universe to all, regardless of location or latitude. Treasures of the Southern Sky celebrates the remarkable beauty and richness of the southern sky in words and with world-class imagery. In part, a photographic anthology of deep sky wonders south of the celestial equator, this book also celebrates th...

  14. Information geometry of Gaussian channels

    International Nuclear Information System (INIS)

    Monras, Alex; Illuminati, Fabrizio

    2010-01-01

    We define a local Riemannian metric tensor in the manifold of Gaussian channels and the distance that it induces. We adopt an information-geometric approach and define a metric derived from the Bures-Fisher metric for quantum states. The resulting metric inherits several desirable properties from the Bures-Fisher metric and is operationally motivated by distinguishability considerations: It serves as an upper bound to the attainable quantum Fisher information for the channel parameters using Gaussian states, under generic constraints on the physically available resources. Our approach naturally includes the use of entangled Gaussian probe states. We prove that the metric enjoys some desirable properties like stability and covariance. As a by-product, we also obtain some general results in Gaussian channel estimation that are the continuous-variable analogs of previously known results in finite dimensions. We prove that optimal probe states are always pure and bounded in the number of ancillary modes, even in the presence of constraints on the reduced state input in the channel. This has experimental and computational implications. It limits the complexity of optimal experimental setups for channel estimation and reduces the computational requirements for the evaluation of the metric: Indeed, we construct a converging algorithm for its computation. We provide explicit formulas for computing the multiparametric quantum Fisher information for dissipative channels probed with arbitrary Gaussian states and provide the optimal observables for the estimation of the channel parameters (e.g., bath couplings, squeezing, and temperature).

  15. Channel Simulation in Quantum Metrology

    Directory of Open Access Journals (Sweden)

    Laurenza Riccardo

    2018-04-01

    Full Text Available In this review we discuss how channel simulation can be used to simplify the most general protocols of quantum parameter estimation, where unlimited entanglement and adaptive joint operations may be employed. Whenever the unknown parameter encoded in a quantum channel is completely transferred in an environmental program state simulating the channel, the optimal adaptive estimation cannot beat the standard quantum limit. In this setting, we elucidate the crucial role of quantum teleportation as a primitive operation which allows one to completely reduce adaptive protocols over suitable teleportation-covariant channels and derive matching upper and lower bounds for parameter estimation. For these channels,wemay express the quantum Cramér Rao bound directly in terms of their Choi matrices. Our review considers both discrete- and continuous-variable systems, also presenting some new results for bosonic Gaussian channels using an alternative sub-optimal simulation. It is an open problem to design simulations for quantum channels that achieve the Heisenberg limit.

  16. Las imágenes inducidas de Tierra del Fuego (Argentina. Cambios y permanencias en el contenido de la promoción turística oficial (1990-2012

    Directory of Open Access Journals (Sweden)

    Patricia Andrea Mosti

    2016-01-01

    Full Text Available La imagen turística es una construcción mental y social que guarda relación con los atributos tangibles e intangibles del destino. La promoción turística contribuye a conformar la imagen del destino atendiendo a los imaginarios de los posibles consumidores y a los atributos del territorio que se deciden poner en valor y promocionar. El objetivo general de esta investigación es indagar sobre las continuidades y los cambios en el contenido del discurso promocional oficial de Tierra del Fuego y su vinculación con el imaginario de la región austral. Se analizó el contenido visual y textual del discurso promocional que se difunde en los folletos turísticos elaborados desde la década del 90’ hasta el presente.

  17. Evaluación cualitativa de la satisfacción de los ciudadanos usuarios de un programa municipal de regularización de la tenencia de la tierra

    OpenAIRE

    Adriana Velázquez García; Jorge Arzate Salgado

    2015-01-01

    El artículo analiza la percepción del ciudadano al hacer uso de un programa de gobierno en términos de su satisfacción en dos aspectos: la atención recibida y los resultados obtenidos. Se presenta un estudio de caso de un programa de regularización de la tenencia de la tierra gestionado por un gobierno municipal de Toluca, en el Estado de México. La perspectiva teórica y metodológica gira en torno a la evaluación de políticas utilizando teoría fundamentada; gracias a la cual se logran detecta...

  18. Localización de faltas en sistemas de distribución de energía eléctrica con neutro puesta a tierra mediante método basado en el modelo

    OpenAIRE

    Corrionero Salinero, Quintín

    2015-01-01

    1) Tema abordado: se trata de definir e implementar un sistema de localización de faltas para redes de distribución de energía eléctrica, con un régimen de neutro puesto a tierra a través de una resistencia limitadora. Un porcentaje elevado del tiempo necesario para reponer una avería en este tipo de redes es la localización de la falta en la línea eléctrica. En muchas ocasiones el propio trazado de la línea a través de una orografía muy montañosa, como el caso de la zona norte de España, y ...

  19. Skeletal Muscle Na+ Channel Disorders

    Directory of Open Access Journals (Sweden)

    Dina eSimkin

    2011-10-01

    Full Text Available Five inherited human disorders affecting skeletal muscle contraction have been traced to mutations in the gene encoding the voltage-gated sodium channel Nav1.4. The main symptoms of these disorders are myotonia or periodic paralysis caused by changes in skeletal muscle fiber excitability. Symptoms of these disorders vary from mild or latent disease to incapacitating or even death in severe cases. As new human sodium channel mutations corresponding to disease states become discovered, the importance of understanding the role of the sodium channel in skeletal muscle function and disease state grows.

  20. REC profile 2: Southern Electric

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    A review is presented of South Electric plc, one of the United Kingdom's Regional Electricity Companies (RECs), at present distributing electric power in central southern England. Known in financial markets as an efficient performer, the staff reductions and changes of employment conditions undertaken to achieve this end are described. The need to maintain success in its core business, while simultaneously seeking diversification, drive the company's keen competitive edge. The relationship between the RECs and the electricity regulator is also explored, as Southern Electric considers a friendly merger with another REC to improve its market competitiveness in price terms. (UK)

  1. Southern states' routing agency report

    International Nuclear Information System (INIS)

    1989-02-01

    The Southern states' routing agency report is a compendium of 16-southern states' routing programs relative to the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source ad scope of the agencies' rulemaking authority. Additionally, the state agency and contact designated by the state's governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed

  2. Southern States' Routing Agency Report

    International Nuclear Information System (INIS)

    1990-03-01

    The Southern States' Routing Agency Report is a compendium of 16-southern states' routing program for the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source and scope of the agencies' rulemaking authority. Additionally, the state agency and contact designated by the state's governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed

  3. Sexty Southerners: Sexting Content and Behaviors among Selected Southern Undergraduates

    Science.gov (United States)

    Hudson, Heather K.; Marshall, S. Alexandra

    2016-01-01

    Sexting is defined as sending/posting/sharing sexually explicit messages or nude/semi-nude images via electronic communication. Purpose: The purpose of this study was to assess and determine relationships of sexting behavioral intentions, sexting behaviors, and sexting content among selected Southern undergraduate students. Methods: Survey…

  4. «Huarpes no tan huarpes» y «hombres modernos»: interpelaciones étnicas y disputas por las últimas tierras irrigadas en Mendoza (Argentina

    Directory of Open Access Journals (Sweden)

    Leticia Saldi

    2015-05-01

    Full Text Available A través de un estudio etnográfico en la periferia del oasis de riego más importante del centro-oeste argentino, se analiza la intervención de persistentes representaciones étnico-raciales y ambientales en la delimitación de áreas irrigadas y de grupos sociales que ostentan la tenencia del agua y la tierra. Los grupos situados a uno y otro lado de los últimos canales de riego son interpelados desde paradigmas modernistas que vinculan a la tenencia del agua, la propiedad privada y la producción vitivinícola con la herencia europea y la idea de progreso, mientras que lo no irrigado, la tenencia comunitaria de la tierra y el pastoreo trashumante se asocia a la descendencia indígena huarpe y a la idea de atraso o involución. Debido a la presencia de dos espacios y grupos socio-culturales supuestamente autónomos, opuestos y separados por los últimos canales de riego es que se los conceptualiza como frontera hídrica. Esta, a pesar de ser considerada como natural y fija, es por el contrario artificial y dinámica, producto de luchas sociales y simbólicas por el agua y por la obtención de legitimidad como grupo socio-cultural capaz de obtenerla y controlarla. Asimismo se resaltan la presencia no solo de actores liminales, ni huarpes ni de origen europeo, sino también de alianzas que pueden llevar a la reconfiguración de espacios irrigados y de grupos socioculturales capaces de dar batalla en las disputas por los recursos naturales.

  5. Empleo del método estratigráfico en el estudio de la vivienda rural vernácula construida con tierra. Un caso de aplicación en La Rioja, Argentina

    Directory of Open Access Journals (Sweden)

    Rolón, Guillermo

    2010-12-01

    Full Text Available Earthen architecture, as being study subject, began in the last quarter of the twentieth century caused by the urgent need to preserve this type of building heritage worldwide. Nowadays, its scope has significantly increased and linked with other disciplinary fields. In this article, we present the preliminary results obtained from the study of earthen historic building by using theoretical and methodological tools developed within Archaeology of Architecture. The case herein discussed is a rural dwelling which was continuously inhabited. It was built during the second half of the nineteenth century in the valley regions in La Rioja province (Argentina. The study was jointly carried out using the wall stratigraphic method, the typology of rural housing and the analysis of different construction techniques.La Arquitectura en Tierra, como campo temático específico dentro de la disciplina de Arquitectura, renace a partir del último cuarto de siglo XX impulsada por la urgente necesidad de preservar este tipo de patrimonio construido en todo el mundo. En la actualidad, su campo de acción se ha incrementado notablemente, del mismo modo que su vinculación con otras disciplinas. En este texto exponemos los resultados previos surgidos del estudio de un edificio histórico doméstico en tierra empleando herramientas teóricas y metodológicas desarrolladas en el ámbito de la Arqueología de la Arquitectura. El caso abordado corresponde a una vivienda rural popular construida durante la segunda mitad del siglo XIX en la región de los valles de la provincia argentina de La Rioja, con continuidad de uso hasta la actualidad. El estudio fue realizado empleando conjuntamente el método estratigráfico de alzados, la tipología de vivienda rural y el análisis de las diferentes técnicas constructivas.

  6. Interferometric Meteor Head Echo Observations using the Southern Argentina Agile Meteor Radar (SAAMER)

    Science.gov (United States)

    Janches, D.; Hocking, W.; Pifko, S.; Hormaechea, J. L.; Fritts, D. C.; Brunini, C; Michell, R.; Samara, M.

    2013-01-01

    A radar meteor echo is the radar scattering signature from the free-electrons in a plasma trail generated by entry of extraterrestrial particles into the atmosphere. Three categories of scattering mechanisms exist: specular, nonspecular trails, and head-echoes. Generally, there are two types of radars utilized to detect meteors. Traditional VHF meteor radars (often called all-sky1radars) primarily detect the specular reflection of meteor trails traveling perpendicular to the line of sight of the scattering trail, while High Power and Large Aperture (HPLA) radars efficiently detect meteor head-echoes and, in some cases, non-specular trails. The fact that head-echo measurements can be performed only with HPLA radars limits these studies in several ways. HPLA radars are very sensitive instruments constraining the studies to the lower masses, and these observations cannot be performed continuously because they take place at national observatories with limited allocated observing time. These drawbacks can be addressed by developing head echo observing techniques with modified all-sky meteor radars. In addition, the fact that the simultaneous detection of all different scattering mechanisms can be made with the same instrument, rather than requiring assorted different classes of radars, can help clarify observed differences between the different methodologies. In this study, we demonstrate that such concurrent observations are now possible, enabled by the enhanced design of the Southern Argentina Agile Meteor Radar (SAAMER) deployed at the Estacion Astronomica Rio Grande (EARG) in Tierra del Fuego, Argentina. The results presented here are derived from observations performed over a period of 12 days in August 2011, and include meteoroid dynamical parameter distributions, radiants and estimated masses. Overall, the SAAMER's head echo detections appear to be produced by larger particles than those which have been studied thus far using this technique.

  7. Anatomy of La Jolla submarine canyon system; offshore southern California

    Science.gov (United States)

    Paull, C.K.; Caress, D.W.; Lundsten, E.; Gwiazda, R.; Anderson, K.; McGann, M.; Conrad, J.; Edwards, B.; Sumner, E.J.

    2013-01-01

    An autonomous underwater vehicle (AUV) carrying a multibeam sonar and a chirp profiler was used to map sections of the seafloor within the La Jolla Canyon, offshore southern California, at sub-meter scales. Close-up observations and sampling were conducted during remotely operated vehicle (ROV) dives. Minisparker seismic-reflection profiles from a surface ship help to define the overall geometry of the La Jolla Canyon especially with respect to the pre-canyon host sediments. The floor of the axial channel is covered with unconsolidated sand similar to the sand on the shelf near the canyon head, lacks outcrops of the pre-canyon host strata, has an almost constant slope of 1.0° and is covered with trains of crescent shaped bedforms. The presence of modern plant material entombed within these sands confirms that the axial channel is presently active. The sand on the canyon floor liquefied during vibracore collection and flowed downslope, illustrating that the sediment filling the channel can easily fail even on this gentle slope. Data from the canyon walls help constrain the age of the canyon and extent of incision. Horizontal beds of moderately cohesive fine-grained sediments exposed on the steep canyon walls are consistently less than 1.232 million years old. The lateral continuity of seismic reflectors in minisparker profiles indicate that pre-canyon host strata extend uninterrupted from outside the canyon underneath some terraces within the canyon. Evidence of abandoned channels and point bar-like deposits are noticeably absent on the inside bend of channel meanders and in the subsurface of the terraces. While vibracores from the surface of terraces contain thin (< 10 cm) turbidites, they are inferred to be part of a veneer of recent sediment covering pre-canyon host sediments that underpin the terraces. The combined use of state of the art seafloor mapping and exploration tools provides a uniquely detailed view of the morphology within an active submarine canyon.

  8. Anatomy of La Jolla submarine canyon system; offshore southern California

    Science.gov (United States)

    Paull, C.K.; Caress, D.W.; Lundsten, E.; Gwiazda, R.; Anderson, K.; McGann, M.; Conrad, J.; Edwards, B.; Sumner, E.J.

    2013-01-01

    An autonomous underwater vehicle (AUV) carrying a multibeam sonar and a chirp profiler was used to map sections of the seafloor within the La Jolla Canyon, offshore southern California, at sub-meter scales. Close-up observations and sampling were conducted during remotely operated vehicle (ROV) dives. Minisparker seismic-reflection profiles from a surface ship help to define the overall geometry of the La Jolla Canyon especially with respect to the pre-canyon host sediments. The floor of the axial channel is covered with unconsolidated sand similar to the sand on the shelf near the canyon head, lacks outcrops of the pre-canyon host strata, has an almost constant slope of 1.0° and is covered with trains of crescent shaped bedforms. The presence of modern plant material entombed within these sands confirms that the axial channel is presently active. The sand on the canyon floor liquefied during vibracore collection and flowed downslope, illustrating that the sediment filling the channel can easily fail even on this gentle slope. Data from the canyon walls help constrain the age of the canyon and extent of incision. Horizontal beds of moderately cohesive fine-grained sediments exposed on the steep canyon walls are consistently less than 1.232 million years old. The lateral continuity of seismic reflectors in minisparker profiles indicate that pre-canyon host strata extend uninterrupted from outside the canyon underneath some terraces within the canyon. Evidence of abandoned channels and point bar-like deposits are noticeably absent on the inside bend of channel meanders and in the subsurface of the terraces. While vibracores from the surface of terraces contain thin (art seafloor mapping and exploration tools provides a uniquely detailed view of the morphology within an active submarine canyon.

  9. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected......'s mixing-length theory with a mixing length that is proportional to the height of the fluid layer. Using averaged boundary-layer equations, taking into account the friction with the channel walls and the eddy viscosity, the flow both upstream and downstream of the jump can be understood. For the downstream...... subcritical flow, we assume that the critical height is attained close to the channel outlet. We use mass and momentum conservation to determine the position of the jump and obtain an estimate which is in rough agreement with our experiment. We show that the averaging method with a varying velocity profile...

  10. Green channel cargo inspection system

    International Nuclear Information System (INIS)

    Shi Yuanping; Yu Jingsheng; Sun Hongqiang; Hao Pu; Cai Wenxia

    2011-01-01

    A radiation detection device was installed in the lanes of a highway toll station, radioactive rays which was collimated emitted through the measured, and arrived the detector. The average density of the fresh agricultural products belonged to Green channel and other prohibited items vary greatly, the absorption of radiation are different between the Green Channel Cargo and other substances. Prior to the experimental group, different standard samples which represent different models and goods were measured, the different standard samples were stored in a computer database. When the trucks get through the Green Channel, the detector will detect the radiation signal and bring to the computer, the computer will process the measured data, and make a conclusion whether the goods are Green Channel cargo. (authors)

  11. Flooding correlations in narrow channel

    International Nuclear Information System (INIS)

    Kim, S. H.; Baek, W. P.; Chang, S. H.

    1999-01-01

    Heat transfer in narrow gap is considered as important phenomena in severe accidents in nuclear power plants. Also in heat removal of electric chip. Critical heat flux(CHF) in narrow gap limits the maximum heat transfer rate in narrow channel. In case of closed bottom channel, flooding limited CHF occurrence is observed. Flooding correlations will be helpful to predict the CHF in closed bottom channel. In present study, flooding data for narrow channel geometry were collected and the work to recognize the effect of the span, w and gap size, s were performed. And new flooding correlations were suggested for high-aspect-ratio geometry. Also, flooding correlation was applied to flooding limited CHF data

  12. Multi-channel Kondo necklace

    International Nuclear Information System (INIS)

    Fazekas, P.; Kee Haeyoung.

    1993-06-01

    A multi-channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins τ J , j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig

  13. Experimentation with PEC channel prototype

    International Nuclear Information System (INIS)

    Caponetti, R.; Iacovelli, M.

    1984-01-01

    Experimentation on prototypes of PEC components is presently being carried out at Casaccia CRE. This report shows the results of the first cycle of experimentation of the central channel, concerning the aspects of sodium removal after experimentation

  14. Multi-channel Kondo necklace

    Energy Technology Data Exchange (ETDEWEB)

    Fazekas, P; Haeyoung, Kee

    1993-06-01

    A multi-channel generalization of Doniach`s Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins {tau}{sub J}, j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig.

  15. FMCG companies specific distribution channels

    Directory of Open Access Journals (Sweden)

    Ioana Barin

    2009-12-01

    Full Text Available Distribution includes all activities undertaken by the producer, alone or in cooperation, since the end of the final finished products or services until they are in possession of consumers. The distribution consists of the following major components: distribution channels or marketing channels, which together form a distribution network; logistics o rphysical distribution. In order to effective achieve, distribution of goods requires an amount of activities and operational processes related to transit of goods from producer to consumer, the best conditions, using existing distribution channels and logistics system. One of the essential functions of a distribution is performing acts of sale, through which, with the actual movement of goods, their change of ownership takes place, that the successive transfer of ownership from producer to consumer. This is an itinerary in the economic cycle of goods, called the distribution channel.

  16. Marketing channel behaviour and performance

    OpenAIRE

    Duarte, Margarida

    2000-01-01

    Thesis submitted to University of Manchester for the degree of Doctor of Philosophy in the Faculty of Business Administration. A major aim of this study is to offer a relatively comprehensive picture of marketing channel behaviour and performance. Given the statistical difficulties in testing a very large, comprehensive model to achieve this aim, two separate but overlapping models are proposed. One model specifically addresses behaviour in marketing channels, while the other integrates k...

  17. Channel coincidence counter: version 1

    International Nuclear Information System (INIS)

    Krick, M.S.; Menlove, H.O.

    1980-06-01

    A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

  18. TRP Channels in Human Prostate

    Directory of Open Access Journals (Sweden)

    Carl Van Haute

    2010-01-01

    Full Text Available This review gives an overview of morphological and functional characteristics in the human prostate. It will focus on the current knowledge about transient receptor potential (TRP channels expressed in the human prostate, and their putative role in normal physiology and prostate carcinogenesis. Controversial data regarding the expression pattern and the potential impact of TRP channels in prostate function, and their involvement in prostate cancer and other prostate diseases, will be discussed.

  19. Southern African Journal of Environmental Education

    African Journals Online (AJOL)

    The Southern African Journal of Environmental Education (SAJEE) is an accredited and ... It is published at least once a year, by the Environmental Education Association of Southern Africa (EEASA). ... AJOL African Journals Online. HOW TO ...

  20. Southern Coal Corporation Clean Water Settlement

    Science.gov (United States)

    Southern Coal Corporation is a coal mining and processing company headquartered in Roanoke, VA. Southern Coal Corporation and the following 26 affiliated entities are located in Alabama, Kentucky, Tennessee, Virginia and West Virginia