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Sample records for achala sierras pampeanas

  1. Geoquímica de ríos de montaña en las Sierras Pampeanas: I. Vertientes y arroyos del batolito de Achala, provincia de Córdoba, Argentina Geochemistry of mountain rivers in the Sierras Pampeanas: I. Springs and streams in the Achala batholith, Córdoba province, Argentina

    OpenAIRE

    A. I. Pasquini; L. B. Grosso; A. P. Mangeaud; P. J. Depetris

    2002-01-01

    Se analiza la composición química de vertientes y arroyos de altura (>1100 m s.n.m.) sobre el batolito de Achala en las Sierras Pampeanas de Córdoba, donde la litología dominante es un monzogranito porfírico. El agua tiene una composición mayoritaria bicarbonatada/sódico-potásica a cálcica. La concentración de los elementos disueltos tiene un orden de magnitud entre 10³ y 10(7) veces inferior a la corteza continental superior y al granito dominante. La concentración de los elementos químicos ...

  2. Hallazgo de espeleotemas silíceas en rocas graníticas del batolito de Achala, Sierras Pampeanas de Córdoba Occurrence of silica speothems in granitic rocks of the Achala batholith, Sierras Pampeanas of Córdoba

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    Marcela A. Cioccale

    2008-09-01

    Full Text Available Se presentan los primeros resultados en relación con el hallazgo de espeleotemas silíceas en rocas graníticas del batolito de Achala (Córdoba. Estas espeleotemas constituyen formas de acumulación en un ambiente dominado por procesos erosivos; alcanzando un desarrollo de unos de pocos milímetros hasta dos centímetros de espesor. Se localizan en grietas abiertas y paredes de tafonis. Presentan morfologías variadas que incluyen estalactitas y espeleotemas tipo flowstone. Están compuestas por sílice amorfa (ópalo A, yeso y fragmentos detríticos de cuarzo, feldespatos y micas. El modelado geoquímico, mediante el programa PHREEQC, permite simular la formación de estas espeleotemas a partir de procesos de evaporación del agua que circula a través de la roca fracturada.We are reporting on the occurrence of silica speleothems in granitic outcrops of the Achala batholith (Córdoba. Speleothems are accumulation forms which occur in environments dominated by erosive processes. They usually reach a thickness that varies between a few milimeters and 2 cm, and grow in fractures or in taffonis walls. Its morphology is varied and includes stalactites and flowstonetype speleothems. They are mainly composed of amorphous silica (opal-A and mineral detritus (quartz, feldspar, and mica. PHREEQC modelling allows simulating the genesis of speleothems, progressively increasing the evaporation of meteoric water that flows through fractured zones.

  3. Geoquímica de ríos de montaña en las Sierras Pampeanas: I. Vertientes y arroyos del batolito de Achala, provincia de Córdoba, Argentina

    OpenAIRE

    A. I. Pasquini; L. B. Grosso; A. P. Mangeaud; P. J. Depetris

    2002-01-01

    Se analiza la composición química de vertientes y arroyos de altura (>1100 m s.n.m.) sobre el batolito de Achala en las Sierras Pampeanas de Córdoba, donde la litología dominante es un monzogranito porfírico. El agua tiene una composición mayoritaria bicarbonatada/sódico-potásica a cálcica. La concentración de los elementos disueltos tiene un orden de magnitud entre 10³ y 10(7) veces inferior a la corteza continental superior y al granito dominante. La concentración de los elementos químicos ...

  4. Geoquímica de ríos de montaña en las Sierras Pampeanas: I. Vertientes y arroyos del batolito de Achala, provincia de Córdoba, Argentina Geochemistry of mountain rivers in the Sierras Pampeanas: I. Springs and streams in the Achala batholith, Córdoba province, Argentina

    Directory of Open Access Journals (Sweden)

    A. I. Pasquini

    2002-12-01

    Full Text Available Se analiza la composición química de vertientes y arroyos de altura (>1100 m s.n.m. sobre el batolito de Achala en las Sierras Pampeanas de Córdoba, donde la litología dominante es un monzogranito porfírico. El agua tiene una composición mayoritaria bicarbonatada/sódico-potásica a cálcica. La concentración de los elementos disueltos tiene un orden de magnitud entre 10³ y 10(7 veces inferior a la corteza continental superior y al granito dominante. La concentración de los elementos químicos está vinculada con el grado de movilidad de los mismos bajo condiciones de meteorización incipiente. Los elementos más móviles (alcalinos y alcalinotérreos presentan las concentraciones más elevadas en el agua y en la roca, mientras los más inmóviles (Al, Ga, Ti, Zr, Hf, Th y tierras raras exhiben las más bajas. Ambos grupos de elementos están sujetos a un control litológico significativo. Los metales de transición, tienen solubilidades y concentraciones variables, sugiriendo la existencia de otros controles además del litológico. Los iones mayoritarios evidencian una dilución estival cercana al 60%, mientras que los elementos traza manifiestan un incremento de sus concentraciones por movilización durante el período estival. Las características geológicas de la región, junto con su condición climática semiárida, favorecen el predominio de un régimen de denudación "limitado por la meteorización", donde los procesos de erosión física predominan sobre la meteorización química. Bajo estas condiciones, las características geoquímicas del agua en la región, escasamente afectada por la actividad antrópica, ponen de manifiesto el control que ejercen la litología y el relieve sobre las mismas.The chemical composition of mountainous (>1,100 m a.s.l. springs and streams from the Achala batholith, in the Pampean Range of Córdoba, Argentina are analized; in this area, the most important lithology is porphyritic monzogranite

  5. Hallazgo de espeleotemas silíceas en rocas graníticas del batolito de Achala, Sierras Pampeanas de Córdoba

    Directory of Open Access Journals (Sweden)

    Marcela A. Cioccale

    2008-09-01

    Full Text Available Se presentan los primeros resultados en relación con el hallazgo de espeleotemas silíceas en rocas graníticas del batolito de Achala (Córdoba. Estas espeleotemas constituyen formas de acumulación en un ambiente dominado por procesos erosivos; alcanzando un desarrollo de unos de pocos milímetros hasta dos centímetros de espesor. Se localizan en grietas abiertas y paredes de tafonis. Presentan morfologías variadas que incluyen estalactitas y espeleotemas tipo flowstone. Están compuestas por sílice amorfa (ópalo A, yeso y fragmentos detríticos de cuarzo, feldespatos y micas. El modelado geoquímico, mediante el programa PHREEQC, permite simular la formación de estas espeleotemas a partir de procesos de evaporación del agua que circula a través de la roca fracturada.

  6. Geoquímica de ríos de montaña en las Sierras Pampeanas: I. Vertientes y arroyos del batolito de Achala, provincia de Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    A. I. Pasquini

    2002-12-01

    Full Text Available Se analiza la composición química de vertientes y arroyos de altura (>1100 m s.n.m. sobre el batolito de Achala en las Sierras Pampeanas de Córdoba, donde la litología dominante es un monzogranito porfírico. El agua tiene una composición mayoritaria bicarbonatada/sódico-potásica a cálcica. La concentración de los elementos disueltos tiene un orden de magnitud entre 10³ y 10(7 veces inferior a la corteza continental superior y al granito dominante. La concentración de los elementos químicos está vinculada con el grado de movilidad de los mismos bajo condiciones de meteorización incipiente. Los elementos más móviles (alcalinos y alcalinotérreos presentan las concentraciones más elevadas en el agua y en la roca, mientras los más inmóviles (Al, Ga, Ti, Zr, Hf, Th y tierras raras exhiben las más bajas. Ambos grupos de elementos están sujetos a un control litológico significativo. Los metales de transición, tienen solubilidades y concentraciones variables, sugiriendo la existencia de otros controles además del litológico. Los iones mayoritarios evidencian una dilución estival cercana al 60%, mientras que los elementos traza manifiestan un incremento de sus concentraciones por movilización durante el período estival. Las características geológicas de la región, junto con su condición climática semiárida, favorecen el predominio de un régimen de denudación "limitado por la meteorización", donde los procesos de erosión física predominan sobre la meteorización química. Bajo estas condiciones, las características geoquímicas del agua en la región, escasamente afectada por la actividad antrópica, ponen de manifiesto el control que ejercen la litología y el relieve sobre las mismas.

  7. La susceptibilidad magnética del batolito de Achala (Devónico, Sierra Grande de Córdoba y sus diferencias con otros granitos achalianos

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    Silvana E. Geuna

    2008-09-01

    Full Text Available El magmatismo devónico de las Sierras Pampeanas de Córdoba y San Luis está representado por batolitos y plutones de composición monzogranítica y forma subelíptica, emplazados en un basamento metamórfico-plutónico eopaleozoico. Se distinguen dos grupos: el primero, compuesto por granitoides con hornblenda-biotita, metaluminosos a débilmente peraluminosos; y el segundo, formado por granitoides con biotita y muscovita, peraluminosos. Ambos grupos se caracterizan respectivamente por tener magnetita e ilmenita como fases accesorias, lo cual genera propiedades magnéticas distintivas. Entre ellos, el batolito de Achala, Córdoba, con una extensión de casi 2.500 km², es un buen exponente de los granitos paramagnéticos (no magnéticos. Su mineralogía magnética fue caracterizada en cuarenta y un sitios, la mayoría de ellos en el Monzogranito Achala. Se determinó una susceptibilidad magnética promedio muy baja, 15 x 10-5 (SI, controlada por el contenido de biotita e ilmeno- hematita. Veintiún sitios mostraron remanencia magnética estable portada por hematita, que aparece como un mineral accesorio, intercrecida con discos de exsolución de (hemoilmenita. La anisotropía de susceptibilidad magnética es débil y predominan las formas obladas, como es usual en fábricas magmáticas de granitos paramagnéticos; casi no se obtuvieron lineaciones. El grado de anisotropía es mayor en zonas con cizallamiento magmático, debido al efecto de la deformación subsolidus. El magnetismo débil del monzogranito de Achala contrasta con el carácter magnético de los plutones monzograníticos porfíricos más representativos de otros batolitos de la región, como Renca, Cerro Áspero y Las Chacras-Piedras Coloradas. La virtual ausencia de magnetita, junto con la presencia de ilmeno-hematita exsuelta, indica que un enfriamiento bajo condiciones oxidantes sería el responsable del carácter paramagnético de Achala. Como consecuencia de aplicación pr

  8. Datos preliminares sobre el metamorfismo de la Sierra de Pie de Palo, Sierras Pampeanas Occidentales (Argentina)

    OpenAIRE

    Edgardo G. Baldo; Casquet, César; Galindo Francisco, Mª del Carmen

    1998-01-01

    The Sierra de Pie de Palo belongs to the Western Sierras Pampeanas. Although still poorly known in detail, the sierra consists of a relatively autochthonous sequence of shelf sediments metamorphosed to low grade (the Caucete Group) and an allochthonous complex of polymetamorphic medium-to-high grade igneous and sedimentary rocks thrust towards the west and northwest. Mylonitization is widespread. Radiometric dating by different methods (U-Pb, 4°Ar/39Ar and K-Ar) suggests that at l...

  9. Datos preliminares sobre el metamorfismo de la Sierra de Pie de Palo, Sierras Pampeanas Occidentales (Argentina)

    OpenAIRE

    Edgardo G. Baldo; Casquet Martín, César; Galindo, Carmen

    1997-01-01

    The Sierra de Pie de Palo belongs to the Western Sierras Pampeanas. Although still poorly known in detail, the sierra consists of a relatively autochthonous sequence of shelf sediments metamorphosed to low grade (the Caucete Group) and an allochthonous complex of polymetamorphic medium-to-high grade igneous and sedimentary rocks thrust towards the west and northwest. Mylonitization is widespread. Radiometric dating by different methods (U-Pb, 40Ar/39Ar and K-Ar) suggests that at least two tec...

  10. La susceptibilidad magnética del batolito de Achala (Devónico, Sierra Grande de Córdoba y sus diferencias con otros granitos achalianos The magnetic susceptibility of the Achala Batholith (Devonian, Sierra Grande de Córdoba and its difference with other Achalian granites

    Directory of Open Access Journals (Sweden)

    Silvana E. Geuna

    2008-09-01

    Full Text Available El magmatismo devónico de las Sierras Pampeanas de Córdoba y San Luis está representado por batolitos y plutones de composición monzogranítica y forma subelíptica, emplazados en un basamento metamórfico-plutónico eopaleozoico. Se distinguen dos grupos: el primero, compuesto por granitoides con hornblenda-biotita, metaluminosos a débilmente peraluminosos; y el segundo, formado por granitoides con biotita y muscovita, peraluminosos. Ambos grupos se caracterizan respectivamente por tener magnetita e ilmenita como fases accesorias, lo cual genera propiedades magnéticas distintivas. Entre ellos, el batolito de Achala, Córdoba, con una extensión de casi 2.500 km², es un buen exponente de los granitos paramagnéticos (no magnéticos. Su mineralogía magnética fue caracterizada en cuarenta y un sitios, la mayoría de ellos en el Monzogranito Achala. Se determinó una susceptibilidad magnética promedio muy baja, 15 x 10-5 (SI, controlada por el contenido de biotita e ilmeno- hematita. Veintiún sitios mostraron remanencia magnética estable portada por hematita, que aparece como un mineral accesorio, intercrecida con discos de exsolución de (hemoilmenita. La anisotropía de susceptibilidad magnética es débil y predominan las formas obladas, como es usual en fábricas magmáticas de granitos paramagnéticos; casi no se obtuvieron lineaciones. El grado de anisotropía es mayor en zonas con cizallamiento magmático, debido al efecto de la deformación subsolidus. El magnetismo débil del monzogranito de Achala contrasta con el carácter magnético de los plutones monzograníticos porfíricos más representativos de otros batolitos de la región, como Renca, Cerro Áspero y Las Chacras-Piedras Coloradas. La virtual ausencia de magnetita, junto con la presencia de ilmeno-hematita exsuelta, indica que un enfriamiento bajo condiciones oxidantes sería el responsable del carácter paramagnético de Achala. Como consecuencia de aplicación pr

  11. Active tectonics in the Argentine Precordillera and Western Sierras Pampeanas

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    L.L. Siame

    2006-12-01

    Full Text Available The Andean foreland of western Argentina (28°S-33°S corresponds to retroarc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. This region is characterized by high levels of seismic activity and crustal active faulting. To improve earthquake source identification and characterization in the San Juan region, data from seismology, structural geology and quantitative geomorphology were integrated and combined to provide a seismotectonic model. In this seismotectonic model, the Andean back-arc of western Argentina can be regarded as an obliquely converging foreland where Plio-Quaternary deformations are partitioned between strike-slip and thrust motions that are localized on the E-verging, thin-skinned Argentine Precordillera, and the W-verging thick-skinned Sierras Pampeanas, respectively. In this seismotectonic model, the Sierra Pie de Palo appears to be a key structure playing a major role in the partitioning of the Plio-Quaternary deformations.

  12. Anfibios de las Sierras Pampeanas Centrales de Argentina: diversidad y distribución altitudinal

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    Julián N. Lescano

    2015-09-01

    Full Text Available Amphibians from Sierras Pampeanas Centrales of Argentina: diversity and altitudinal distribution. Sierras Pampeanas Centrales (SPC mountains are located in Córdoba and San Luis provinces (Argentina and represent an area of unique biogeographic importance. In this paper we provide a synthesis about the knowledge of diversity and altitudinal distribution of anurans that inhabit SPC mountains. We compiled a species list through different information sources (field data, biological collections and bibliography. Using this information we characterize altitudinal distribution range of each species and analyze associations between species richness and composition and altitude gradient. We recorded 24 amphibians species belonging to five families. These species are heterogeneously distributed over the altitude gradient of SPC. We detect a linear negative relationship between altitude and species richness and defined assemblages associated with different altitude sectors. The results obtained in the paper represent basic information that will be useful to evaluate anthropogenic impact on this particular and fragile mountain system.

  13. Deformación cuaternaria asociada al frente de levantamiento oriental de las sierras de Velasco y Ambato, Sierras Pampeanas occidentales Quaternary deformation associated with the eastern uplift front of the Sierras de Velasco and Ambato, western Sierras Pampeanas

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    Analía L. Casa

    2010-12-01

    Full Text Available Sobre el frente oriental de la sierra de Velasco y extremo sur de la sierra de Ambato, Sierras Pampeanas Occidentales, se han hallado nuevas evidencias de actividad tectónica cuaternaria en cercanías de la ciudad de La Rioja. Los rasgos reconocidos corresponden a distintos tramos reactivados de las fallas que delimitan los frentes serranos y a estructuras que afectan los depósitos cuaternarios sobre el piedemonte. la sierra de Velasco Oriental se encuentra marginada por fallas de rumbo NNE e inclinación al ONO, mientras que la sierra de Ambato austral presenta estructuras de rumbo NE que inclinan al NO. En el bloque Carrizal estas direcciones se interfieren originando un sector de mayor complejidad estructural. La deformación observada evidencia la persistencia de un régimen compresivo durante el Cuaternario al que se asocian fallas inversas de vergencia oriental a sudoriental. Estas fallas continúan elevando los cordones serranos y constituyen potenciales fuentes sismogénicas.Along the eastern front of the Sierra de Velasco and at the southern end of the Sierra de Ambato, western Sierras Pampeanas, have been found new evidences of Quaternary tectonic activity near La Rioja city. Observed evidences correspond to different reactivated sections of the faults that bound the mountain fronts, as well as to structures affecting the Quaternary deposits on the piedmont. The bounding faults of the Sierra de Velasco Oriental-front exhibit a NNE trend and WNW dip, while structures at the southernmost Ambato range are characterized by NE trend and NW dip. The neotectonic faults of the El Carrizal block are the result of the interference of both structural trends, resulting in a sector with higher structural complexity. The here described deformation show the persistence of a compressive regime during the Quaternary, with eastern to southeastern verging reverse faults. It is considering that these faults are driving the current uplift of the mountain

  14. Active tectonics in the Argentine Precordillera and Western Sierras Pampeanas Tectónica activa en la Precordillera argentina y las Sierras Pampeanas occidentales

    Directory of Open Access Journals (Sweden)

    L.L. Siame

    2006-12-01

    Full Text Available The Andean foreland of western Argentina (28°S-33°S corresponds to retroarc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. This region is characterized by high levels of seismic activity and crustal active faulting. To improve earthquake source identification and characterization in the San Juan region, data from seismology, structural geology and quantitative geomorphology were integrated and combined to provide a seismotectonic model. In this seismotectonic model, the Andean back-arc of western Argentina can be regarded as an obliquely converging foreland where Plio-Quaternary deformations are partitioned between strike-slip and thrust motions that are localized on the E-verging, thin-skinned Argentine Precordillera, and the W-verging thick-skinned Sierras Pampeanas, respectively. In this seismotectonic model, the Sierra Pie de Palo appears to be a key structure playing a major role in the partitioning of the Plio-Quaternary deformations.El antepais andino del centro-oeste de Argentina (28°S-33°S está caracterizado por deformaciones asociadas a la subducción horizontal activa de la placa de Nazca debajo de la litósfera de la placa Sudamericana. En esta región se concentra una importante actividad sísmica y fallamiento cortical activo. Para mejorar la identificación y caracterización de las fuentes sismogénicas en la región de San Juan, fueron integrados y combinados datos de sismología, geología estructural y geomorfología cuantitativa para establecer un modelo sismotectónico. El mismo considera al retroarco del oeste argentino como un antearco con convergencia oblicua donde las deformaciones plio-cuaternarias son particionadas en movimientos compresivos y de transcurrencia dextral. Dichos movimientos están localizados respectivamente en la Precordillera, una faja de pliegues y escurrimientos de cobertura con vergencia hacia el este, y en las Sierras

  15. Nuevas evidencias de deformaciones cuaternarias asociadas a la falla Sierra chica, Sierras pampeanas de Córdoba

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    Guillermo L Sagripanti

    2012-12-01

    Full Text Available En la intraplaca argentina, entre los 31º 45' y 32º 45' de latitud S, en el frente occidental de la Sierra Chica, Sierras Pampeanas de Córdoba, la presencia de morfologías superficiales y deformaciones en sedimentos cuaternarios permiten deducir que la actividad tectónica neógena en la región, tuvo continuidad en el Holoceno y probablemente ha tenido asociada la ocurrencia de paleoterremotos. Los objetivos de la presente contribución son presentar nuevas evidencias de deformaciones cuaternarias asociadas a la falla Sierra Chica, extender su traza hacia el sur en la llanura y hacer una estimación preliminar del potencial sismogénico asociado a esta estructura. Se relevaron siete perfiles transversales a la traza de una falla secundaria del frente principal de levantamiento de la Sierra Chica. Estos presentan el basamento cristalino precámbrico, depósitos conglomerádicos y sedimentos no cohesivos cuaternarios, afectados por deformaciones dúctiles y frágiles correspondientes a reactivaciones pleistocenas y holocenas de la estructura. Los resultados obtenidos han permitido extender la traza de la falla hacia el S en la llanura hasta el arroyo Tegua, relevar estructuras deformacionales en sedimentos finos no reportadas hasta el presente y estimar la magnitud máxima de un terremoto futuro, entre Ms 6,7-7,5 y Mw=7,5, asociado a la falla Sierra Chica.

  16. Geochemical interpretation of gamma-ray spectrometry images from the Achala granite (Cordoba, Argentina)

    International Nuclear Information System (INIS)

    Data of an old spectrometry gamma-ray survey carried out in the Sierras Pampeanas Range by the National Atomic Energy Commission (Argentina) were reprocessed to obtain a corrected digital archive. The geochemical interpretation of the 250 x 250 meters spectrometric grids from the Achala batholith area was based on the behaviour of the radioelements in a peraluminous magma. Spectrometric maps of potassium, uranium, thorium and their ratios were used. In particular, the Th grid was very useful to define the primary magmatic evolution of the granitoids. K and U correlate roughly with Th distribution. The observed positive correlation between Th and U is thought to be the result of surficial leaching of U from uraninite. Finally, U/Th ratio allows to determine both, the magmatic evolution of the rocks and the mineral phase responsible for U content. (author)

  17. Crustal structure of the Eastern Sierras Pampeanas of Argentina using high frequency local receiver functions

    Science.gov (United States)

    Perarnau, Marcelo; Gilbert, Hersh; Alvarado, Patricia; Martino, Roberto; Anderson, Megan

    2012-12-01

    The Eastern Sierras Pampeanas are basement cored outcrops uplifted in the Andean foreland where the easternmost segment of the Pampean flat slab segment starts dipping more steeply into the deeper mantle. These ranges of central Argentina known as the Sierras de Córdoba have an enriched-quartz composition and are bounded by a series of reverse faults. Different models have been suggested to represent the style of the thick-skinned deformation in this area. However the overall structure linking the exposed faults and terrane boundaries with their probable continuation at depth is unknown. In this paper we present images of the crustal structure beneath the Sierras de Córdoba using the common conversion point stacking method of high frequency local receiver functions recorded by the ESP broadband seismic array. The work consists of two transects located around 31°S and 32°S across the Sierras de Córdoba. The results show a consistent sharp Moho signal associated with a high contrast in seismic velocities in good agreement with the granitic character of the crust lying above the mafic upper mantle. The Moho morphology varies exhibiting thicknesses of 38 km in the west to 35 km in the east with a vertical shifting under the Sierra Chica. We relate this variable character to the presence of the boundary between the Pampia terrane and the Rio de La Plata craton. Our results for the intra-crustal structure indicate the presence of three discontinuities in the northern transect and at least two discontinuities in the southern transect. These discontinuities appear vertically displaced beneath the surface traces of the major range bounding faults providing evidence for the continuation to mid-crustal depths of the exposed reverse faults. Thus, the reverse faults seem to have displaced several horizontal intra-crustal interfaces. Finally in the lower crust we found a region which seems to be aseismic.

  18. La actividad neotectónica en la sierra Baja de San Marcos - Cruz del Eje, flanco occidental de las Sierras Pampeanas Orientales

    OpenAIRE

    A Massabie; Sanguinetti, A; G Lo Forte; Cegarra, M.

    2003-01-01

    El área pedemontana de San Marcos Sierra-Cruz del Eje constituye, en la provincia de Córdoba, Argentina, una comarca clave para el análisis neotectónico en las Sierras Pampeanas Orientales. En esta región se han realizado estudios centrados en la unidad morfoestructural sierra Baja de San Marcos donde, aplicando un control múltiple de datos estructurales, geomorfológicos, sedimentológicos, paleontológicos y radimétricos, se ha determinado temporal y espacialmente la evolución de la actividad ...

  19. La estructura ándica de las Sierras Pampeanas basada en los mecanismos focales de terremotos en su región noroeste The Andean structure of the Sierras Pampeanas based on earthquake focal mechanisms in their northwestern region

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    Patricia Alvarado

    2010-12-01

    Full Text Available El modelado de formas de ondas sísmicas de banda ancha de redes globales y de Chile para dos terremotos corticales moderados de la región noroeste de las Sierras Pampeanas ha permitido caracterizar sus mecanismos focales, profundidades hipocentrales y características sismotectónicas. El terremoto de magnitud Mw 5.8 del 28 de mayo de 2002 localizado en el flanco oriental de la sierra de Velasco y el terremoto Mw 6.2 del 7 de setiembre de 2004 con epicentro en la parte sudoccidental de la sierra de Ambato muestran profundidades focales someras de 10 y 8 km, respectivamente. Estos resultados combinados con la sismicidad histórica de la región permiten esbozar la estructura profunda de las Sierras Pampeanas en la región estudiada. El análisis sismológico efectuado en forma conjunta con la interpretación de la estructura superficial y los estudios neotectónicos previos permiten descartar mecanismos extensionales o de deformación mediante desplazamiento de rumbo como los responsables de la estructuración actual de las sierras de Ambato y Velasco. Se realiza la comparación entre el vector de velocidad de convergencia entre las placas de Nazca y Sudamericana, y los vectores relativos de velocidades de GPS en la región de estudio con la sumatoria del tensor momento sísmico para la mayor liberación de energía sísmica de sismos corticales ocurridos en la región en los últimos 30 años. Esta comparación predice una rotación horaria de 50º del eje de máxima compresión (eje P promedio respecto de la orientación hacia el noreste de la convergencia mencionada y muestra una importante partición de la deformación. Se interpreta que esta partición está controlada por la fábrica eopaleozoica del basamento, que ha regulado la orientación y vergencia de las fallas andinas.Modeling of broadband seismic waveforms recorded by global and Chilean networks for two moderate crustal earthquakes of the northwestern Sierras Pampeanas shows

  20. La actividad neotectónica en la sierra Baja de San Marcos - Cruz del Eje, flanco occidental de las Sierras Pampeanas Orientales Neotectonic activity in the Sierra Baja de San Marcos-Cruz del Eje area, west flank of Sierras Pampeanas Orientales

    OpenAIRE

    A Massabie; Sanguinetti, A; G Lo Forte; Cegarra, M.

    2003-01-01

    El área pedemontana de San Marcos Sierra-Cruz del Eje constituye, en la provincia de Córdoba, Argentina, una comarca clave para el análisis neotectónico en las Sierras Pampeanas Orientales. En esta región se han realizado estudios centrados en la unidad morfoestructural sierra Baja de San Marcos donde, aplicando un control múltiple de datos estructurales, geomorfológicos, sedimentológicos, paleontológicos y radimétricos, se ha determinado temporal y espacialmente la evolución de la actividad ...

  1. Regional polyphase deformation of the Eastern Sierras Pampeanas (Argentina Andean foreland): strengths and weaknesses of paleostress inversion

    Science.gov (United States)

    Traforti, Anna; Zampieri, Dario; Massironi, Matteo; Viola, Giulio; Alvarado, Patricia; Di Toro, Giulio

    2016-04-01

    The Eastern Sierras Pampeanas of central Argentina are composed of a series of basement-cored ranges, located in the Andean foreland c. 600 km east of the Andean Cordillera. Although uplift of the ranges is partly attributed to the regional Neogene evolution (Ramos et al. 2002), many questions remain as to the timing and style of deformation. In fact, the Eastern Sierras Pampeanas show compelling evidence of a long lasting brittle history (spanning the Early Carboniferous to Present time), characterised by several deformation events reflecting different tectonic regimes. Each deformation phase resulted in further strain increments accommodated by reactivation of inherited structures and rheological anisotropies (Martino 2003). In the framework of such a polyphase brittle tectonic evolution affecting highly anisotropic basement rocks, the application of paleostress inversion methods, though powerful, suffers from some shortcomings, such as the likely heterogeneous character of fault slip datasets and the possible reactivation of even highly misoriented structures, and thus requires careful analysis. The challenge is to gather sufficient fault-slip data, to develop a proper understanding of the regional evolution. This is done by the identification of internally consistent fault and fracture subsets (associated to distinct stress states on the basis of their geometric and kinematic compatibility) in order to generate a chronologically-constrained evolutionary conceptual model. Based on large fault-slip datasets collected in the Sierras de Cordoba (Eastern Sierras Pampeanas), reduced stress tensors have been generated and interpreted as part of an evolutionary model by considering the obtained results against: (i) existing K-Ar illite ages of fault gouges in the study area (Bense et al. 2013), (ii) the nature and orientation of pre-existing anisotropies and (iii) the present-day stress field due to the convergence of the Nazca and South America plates (main shortening

  2. Comparative seismic and petrographic crustal study between the Western and Eastern Sierras Pampeanas region (31°S

    Directory of Open Access Journals (Sweden)

    P. Alvarado

    2005-12-01

    Full Text Available The ancient Sierras Pampeanas in the central west part of Argentina are a seismically active region in the back-arc of the Andes. Their crystalline basement cored uplifts extend up to 800 km east of the oceanic trench over the flat subduction segment of the Nazca plate. Approximately 40 felt crustal earthquakes, are reported per year for this region. Historic and modern seismicity indicates that the Western Sierras Pampeanas (WSP have more crustal earthquakes of greater-size than the Eastern Sierras Pampeanas (ESP. Remarkable changes in composition and structure also characterize the WSP and ESP basements. We have quantitatively compared both regions using seismological constrains. A recent regional study of moderate earthquakes shows reverse and thrust focal mechanisms occurring at depths down to 25 km in the WSP. In contrast, the ESP have reverse and strike-slip focal mechanisms of shallower depths (< 10 km. A seismic velocity structure of Vp 6.4 km/s, Vp/Vs ~1.80, and thickness 50 km, best represents the WSP crust. The ESP crust is characterized by Vp 6.0 km/s, Vp/Vs < 1.70, and thickness 30 km. These seismological determinations correlate with the interpretation of a different origin for the western and eastern terranes. The WSP show seismic properties indicative of a more mafic-ultramafic thick crust consistent with an oceanic island-arc and back-arc formation. The ESP show crustal seismic properties consistent with a higher silica content and with a formation by the collision of a continental terrane.

  3. Deformación cuaternaria asociada al frente de levantamiento oriental de las sierras de Velasco y Ambato, Sierras Pampeanas occidentales

    Directory of Open Access Journals (Sweden)

    Analía L. Casa

    2010-12-01

    Full Text Available Sobre el frente oriental de la sierra de Velasco y extremo sur de la sierra de Ambato, Sierras Pampeanas Occidentales, se han hallado nuevas evidencias de actividad tectónica cuaternaria en cercanías de la ciudad de La Rioja. Los rasgos reconocidos corresponden a distintos tramos reactivados de las fallas que delimitan los frentes serranos y a estructuras que afectan los depósitos cuaternarios sobre el piedemonte. la sierra de Velasco Oriental se encuentra marginada por fallas de rumbo NNE e inclinación al ONO, mientras que la sierra de Ambato austral presenta estructuras de rumbo NE que inclinan al NO. En el bloque Carrizal estas direcciones se interfieren originando un sector de mayor complejidad estructural. La deformación observada evidencia la persistencia de un régimen compresivo durante el Cuaternario al que se asocian fallas inversas de vergencia oriental a sudoriental. Estas fallas continúan elevando los cordones serranos y constituyen potenciales fuentes sismogénicas.

  4. Los diques comendíticos de Papachacra (Catamarca: magmatismo peralcalino en sierras Pampeanas orientales

    Directory of Open Access Journals (Sweden)

    Fernando Colombo

    2010-03-01

    Full Text Available En Papachacra (Provincia de Catamarca, NO de Argentina hay un plutón compuesto por varios tipos diferentes de granitoides de tipo A con afinidad alcalina. Las rocas más tardías son riolitas peralcalinas (comenditas, que forman diques de hasta 50 cm atravesando el granito biotítico El Portezuelo, el cual está genéticamente desvinculado. Tienen textura porfírica y están compuestas por fenocristales de feldespato potásico (Or97-98 Ab2-3 y egirina (Ac94-98 en una mesostasis afanítica de cuarzo, feldespato potásico, albita, egirina y anfíbol litífero relacionado a la flúor-ferro-leakeíta. Los minerales accesorios son ilmenita, magnetita, óxidos del grupo del pirocloro, epidoto rico en tierras raras, zircón intersticial, monacita- (Ce y un óxido de Nb-Y-Fe no identificado. El contenido de SiO2 varía entre 68,28 y 69,33%, con muy bajo Mg, Ca, Ba, Sr y Eu, y altas concentraciones de Nb (399-409 ppm, Ta (16-34 ppm, Th (46-84 ppm, Y (101-192 ppm, Zn (280-320 ppm, Ga (42-47 ppm y especialmente Zr (2324-3000 ppm. Las comenditas se intruyeron durante un evento magmático anorogénico. Un estudio isotópico (Rb-Sr de reconocimiento hecho a rocas relacionadas indica una edad de 295 + 8 Ma, con una relación 87Sr/86Sr inicial cercana a 0,7041, lo que apunta a una fuente del manto sublitosférico o la base de la corteza inferior. Estas rocas pertenecen a la clase A1 de granitos de tipo A, sugiriendo un origen relacionado a rifting o a puntos calientes, y sus relaciones de elementos trazas muestran afinidades con fundidos relacionados a basaltos de islas oceánicas. En este sentido son diferentes de todos los granitos de tipo A post-devónicos descriptos en Sierras Pampeanas Orientales.

  5. Las superficies de erosión en las Sierras Pampeanas de Córdoba: algunas consideraciones sobre su génesis

    Directory of Open Access Journals (Sweden)

    C.A. Beltramone

    2007-09-01

    Full Text Available Las Sierras Pampeanas de Córdoba constituyen parte de la unidad morfoestructural Sierras Pampeanas Orientales. Se considera la existencia de una sola superficie de erosión, preservada en diferentes posiciones topográficas. Escarpas de fallas limitan las superficies de erosión reconocidas. No fueron reconocidos signos que evidencien el proceso de pedimentación en su base, ni profundos perfiles de meteorización (saprolito. Se consideran a esta superficie como una peneplanicie formada durante el Paleozoico y posteriormente desmembrada por los movimientos tectónicos que dieron lugar a la formación de las sierras de Córdoba.

  6. El magmatismo neopaleozoico en la Sierra de La Huerta, Sierras Pampeanas Occidentales, provincia de San Juan: los pórfidos Marayes Viejo y El Arriero

    Directory of Open Access Journals (Sweden)

    B. Castro de Machuca

    2007-09-01

    Full Text Available Dos cuerpos porfíricos subvolcánicos asignados al ciclo magmático gondwánico intruyen al basamento cristalino de la sierra de La Huerta, Sierras Pampeanas Occidentales, en el área de la quebrada El Arriero (Dacita El Arriero y en el sector de Marayes Viejo (Andesita Marayes Viejo. Se trata de rocas andesíticas a dacíticas de medio a alto K y con afinidad calcoalcalina. Para la Dacita El Arriero se determinó una edad Ar/Ar sobre biotita de 299,9 ± 3,6 Ma y para la Andesita Marayes Viejo una edad K/Ar sobre roca total de 259 ± 13 Ma. La edad obtenida en la Dacita El Arriero constituye la manifestación más temprana del magmatismo neopaleozoico en este sector de las Sierras Pampeanas, y pone en evidencia una actividad volcánica continua a partir del Carbonífero Superior hasta la base del Triásico Inferior. Los estudios efectuados indican que la Andesita Marayes Viejo y la Dacita El Arriero son rocas consanguíneas y tienen signaturas geoquímicas y patrones de tierras raras típicos de arco volcánico consistentes con una zona de subducción activa durante el Neopaleozoico. Sobre la base de la petrología, geoquímica y edades radimétricas, estas litologías pueden ser correlacionadas con volcanitas andesíticas de la Formación Punta del Agua, en la Precordillera de La Rioja.

  7. La actividad neotectónica en la sierra Baja de San Marcos - Cruz del Eje, flanco occidental de las Sierras Pampeanas Orientales

    Directory of Open Access Journals (Sweden)

    A Massabie

    2003-12-01

    Full Text Available El área pedemontana de San Marcos Sierra-Cruz del Eje constituye, en la provincia de Córdoba, Argentina, una comarca clave para el análisis neotectónico en las Sierras Pampeanas Orientales. En esta región se han realizado estudios centrados en la unidad morfoestructural sierra Baja de San Marcos donde, aplicando un control múltiple de datos estructurales, geomorfológicos, sedimentológicos, paleontológicos y radimétricos, se ha determinado temporal y espacialmente la evolución de la actividad neotectónica del fallamiento andino. Se presentan evidencias sobre la reactivación cuaternaria tardía de la Falla Sierra Baja de San Marcos, conspicua falla inversa de vergencia occidental con componentes de desplazamiento de rumbo y de inclinación, enlazando los episodios tectónicos con las modificaciones del paisaje. Estas modificaciones son expresadas por los depósitos de endicamiento del río Quilpo, por los niveles aterrazados, vinculados a los cauces actuales de los ríos de la Costa (San Marcos y Quilpo, y por los cambios en su desarrollo de la red de avenamiento principal de la región. La edad 14C corregida de 2.560±120 aap, obtenida para los sedimentos del endicamiento permite acotar un primer episodio de actividad, Holoceno tardío, de la Falla Sierra Baja de San Marcos. Las observaciones efectuadas sobre la misma estructura, en una trinchera excavada para su investigación, confirman su extensión hacia el noroeste, dan evidencias sobre una segunda etapa de movimientos en el Holoceno tardío y determinan sus características estructurales comunes a otras fallas con actividad neotectónica estudiadas en las Sierras Pampeanas Orientales, las cuales responden a una mecánica transpresiva.

  8. New fission-track ages of mio-pliocene tuffs in the Sierras Pampeanas and Precordillera of Argentina

    International Nuclear Information System (INIS)

    Fission-track dates were determined for 18 volcanic tuff horizons located in nine Neogene foreland basin sequences distributed throughout the Precordillera and Sierras Pampeanas of Northwestern Argentina, an area of nearly horizontal subduction. These and other data indicate that a lower age limit for the sedimentary sequences studied is approximately 17 Ma. Therefore these fission-track dates constrain both the history of volcanic activity and the time of deposition in several foreland basins from the middle Miocene to Recent. Although the dates range from 3.6±0.8 Ma to 17.0±1.9 Ma, there is a marked increase in the number of ashes younger than 9 Ma. This implies that two distinct episodes of volcanic activity affected the region. The source of some of these tuffs is unknown but they are probably limited to the 'flat-slab' region between 27 deg and 32 deg S. Tuffs at Rio Blanco and Santa Florentina that are spatially associated with the Mogotes dacite domes of the Famatina Range represented magmatism bracketed from about 7 to 4 Ma in the region underlain by the flat-subducted plate. The stratigraphic relations in the basins show that the faulting that uplifted Sierra de Famatina was contemporaneous with the volcanism which reached the surface along the bounding faults. (Author)

  9. Nuevas edades radimétricas para la Formación Toro Negro en la Sierra de los Colorados, Sierras Pampeanas Noroccidentales, provincia de La Rioja New radiometric ages for the Toro Negro Fromation in the Sierra de los Colorados, northwestern Sierras Pampeanas

    Directory of Open Access Journals (Sweden)

    P.L. Ciccioli

    2005-03-01

    Full Text Available En este trabajo se dan a conocer nuevas edades radimétricas obtenidas por el método K/Ar roca total sobre dos niveles de tobas vítreas de la parte media-superior de la Formación Toro Negro en la sierra de los Colorados, Sierras Pampeanas Noroccidentales (provincia de La Rioja. Las edades 8,6 ± 0,3 Ma y 6,8 ± 0,2 Ma ubican a la Formación Toro Negro en el Mioceno superior modificando así la edad pliocena establecida anteriormente. Los valores obtenidos presentan un alto grado de confiabilidad, dado que se tratan de tobas vítreas las cuales no tienen ningún signo de retransporte, contaminación ni alteración diagenética. Los niveles de tobas han sido mapeados y georeferenciados con coordenadas obtenidas con GPS. Las muestras presentan una precisa ubicación en la columna estratigráfica y se encuentran lo suficientemente próximas de manera de controlar indirectamente los valores obtenidos.New absolute ages derived from whole rock K/Ar dating of two vitric tuffs collected from the upper-middle part of the Toro Negro Formation in the outcrops of the Sierra de Los Colorados, Sierras Pampeanas Noroccidentales (La Rioja Province are presented herein. The obtained values of 8,6 ± 0,3 Ma and 6,8 ± 0,2 Ma respectively, indicate an Upper Miocene age and challenge the previous Pliocene age proposed for this unit. The results presented here have a high degree of confidence because they do not show evidences of reworking, mixing with terrigenous clastics nor diagenetic alteration. The tuff levels were mapped and georeferenced using GPS coordinates and their close location in the stratigraphic column provides an additional control for the obtained ages.

  10. Geoquímica de ríos de montaña en las Sierras Pampeanas: II. El río Los Reartes, sierra de Comenchingones, provincia de Córdoba Geochemistry of mountain rivers in the Sierras Pampeanas: II. Los Reartes River, Sierra de Comenchingones, Province of Córdoba.

    OpenAIRE

    Andrea I. Pasquini; Karina L. Lecomte; Pedro J. Depetris

    2004-01-01

    Se analiza la hidrogeoquímica de la cuenca del río Los Reartes, un típico sistema hídrico montañoso de las Sierras Pampeanas de Córdoba. La litología dominante está representada por rocas graníticas y gnéisicas del basamento. La altitud máxima es de 2.400 m s.n.m. y la mínima de 670 m s.n.m. Las pendientes decrecen desde el 20% en las nacientes hasta inferiores al 6% en las áreas bajas. El clima es semiárido con una concentración estival de las precipitaciones. El pH de las aguas varía de 6,9...

  11. Time constraints on the tectonic evolution of the eastern Sierras Pampeanas (Central Argentina)

    DEFF Research Database (Denmark)

    Siegesmund, Siegfried; Steenken, A; Martino, R D;

    2010-01-01

    cycle in the neighbouring Sierra de San Luis and has not affected the titanite ages. The PTt evolution can be correlated with the plate tectonic processes responsible for the formation of the Pampean orogene, i.e., the accretion of the Pampean basement to the Río de La Plata craton (M2) and the later...

  12. Control estructural de las mineralizaciones de fluorita del batolito Cerro Áspero, Sierras Pampeanas de Córdoba Structural control of vein-type fluorite deposits of Cerro Áspero batholith, Sierras Pampeanas of Córdoba

    Directory of Open Access Journals (Sweden)

    Jorge E Coniglio

    2010-12-01

    Full Text Available Con más de 1.000.000 t de reservas totales el batolito Cerro Áspero, magmatismo devónico de alto potasio, es portador de las mayores concentraciones de fluorita de las Sierras Pampeanas. Las vetas epitermales son de edad cretácica, subverticales, poseen potencias generalmente menores a 3 m y se extienden a profundidades mayores a 200 metros. Ocurren en un área de 440 km² con una distribución intrabatolítica predominante. La geometría y la cinemática de las estructuras mineralizadas son consistentes con deformación por cizalla simple, dextrógira, con el eje extensional principal (σ3 orientado hacia el NNO. Esta situación implantó en el área estructuras extensionales N70ºE ( 4 km de corrida, que presentan patrones de fallas transcurrentes, con bifurcaciones, deflexiones, aperturas, saltos, cierres y fracturas en échelon asociadas. Los estudios texturales y estructurales en las vetas han permitido distinguir cuatro estadios sucesivos de mineralización que fueron controlados por una actividad discontinua de la cupla dextral. Este modelo estructural es similar a aquéllos propuestos para mineralizaciones de fluorita emplazadas en otros sectores del continente durante el mismo período, los que vinculan el control tectónico con la apertura del océano Atlántico sur. El registro del relleno hidrotermal permitió reconstruir la historia de apertura de las estructuras y puede usarse como un criterio efectivo de prospección y exploración. Las mayores concentraciones de mineral ocurren en las estructuras extensionales y en las flexiones dilatantes de las estructuras asociadas con la zona de cizallamiento principal NNE-SSO, que registran la secuencia mineralizada completa.With over 1,000,000 t of total reserves, the high-K devonian granites of the Cerro Áspero batholith (440 km² are the most important fluorite-bearing granitic suite in the Sierras Pampeanas. The epithermal fluorite veins, of Cretaceous age, fill in steeply dipping

  13. Las fajas de deformación dúctil de las Sierras Pampeanas de Córdoba: Una reseña general

    OpenAIRE

    2003-01-01

    Se describen dieciseis fajas de deformación dúctil, reconocidas hasta el momento en las sierras de Córdoba, atendiendo a su extensión, límites, descripción general de las rocas de falla que la conforman, estructura interna y se da un significado tectónico que permite asignarlas a cuatro grupos. (1) Fajas transcurrentes dextrales paralelas al arco magmático precámbrico-cámbrico, relacionadas con la subducción pampeana durante el Cámbrico inferior. (2) Fajas de desenraizamiento del Orógeno Pamp...

  14. Los granitos peraluminosos de las Sierras de Vinquis, Cerro Negro y Zapata (Sierras Pampeanas, provincia de Catamarca, Argentina

    Directory of Open Access Journals (Sweden)

    Medina, M. E.

    1992-12-01

    Full Text Available The studied plutons are close to several batholiths of this region, as Sierra de Mazán and other, but with some mineralogical peculiarities. The magmatic cordierite, common in proximate places, is scarce, as sillimanite, while the andalusite is very rare, with few tourmaline. Fluorite and allanite are also typical accasories only in the granites of the Sierra de Zapata. All plutons are peraluminous of potassic tendency, with cortical affinity.The interpretation of the geochemical values distinguishes between granites of different maturity, emplaced under a predominant influence of active margin for Cerro Negro and Vinquis, while the batholith of Zapata has, below these concepts, a marked feature of within plate.The mineralogical associations suggest that the granites of Cerro Negro and Vinquis were emplaced to pressures of 2 kb or less and temperature of 650º C, while the granites of Zapata had done under conditions of lesser pressure, between 1.5 and 2.0 kb and lower temperature, 600-650º C.A grandes rasgos, los plutones estudiados tienen semejanzas con otros del entorno regional, tal como los de la Sierra de Mazán, pero con peculiaridades mineralógicas. La cordierita magmática, que en lugares próximos es muy abundante, es aquí escasa, al igual que la sillimanita, mientras que la andalucita es muy rara y la turmalina poco frecuente. La fluorita y allanita son accesorios comunes y de cierta abundancia sólo en los granitos de la Sierra de Zapata.Todos los plutones son peralumínicos y de tendencia potásica, con neta afinidad cortical. El estudio estadístico de datos geoquímicos seleccionados, permite diferenciar agrupaciones que tienen un reflejo satisfactorio en los plutones caracterizados, por encima de las variaciones de facies. La interpretación de los valores geoquímicos distingue granitos de desigual madurez, emplazados bajo una influencia predominante de margen activo o intraplaca de características continentales, en

  15. Control estructural de las mineralizaciones de fluorita del batolito Cerro Áspero, Sierras Pampeanas de Córdoba

    Directory of Open Access Journals (Sweden)

    Jorge E Coniglio

    2010-12-01

    Full Text Available Con más de 1.000.000 t de reservas totales el batolito Cerro Áspero, magmatismo devónico de alto potasio, es portador de las mayores concentraciones de fluorita de las Sierras Pampeanas. Las vetas epitermales son de edad cretácica, subverticales, poseen potencias generalmente menores a 3 m y se extienden a profundidades mayores a 200 metros. Ocurren en un área de 440 km² con una distribución intrabatolítica predominante. La geometría y la cinemática de las estructuras mineralizadas son consistentes con deformación por cizalla simple, dextrógira, con el eje extensional principal (σ3 orientado hacia el NNO. Esta situación implantó en el área estructuras extensionales N70ºE ( 4 km de corrida, que presentan patrones de fallas transcurrentes, con bifurcaciones, deflexiones, aperturas, saltos, cierres y fracturas en échelon asociadas. Los estudios texturales y estructurales en las vetas han permitido distinguir cuatro estadios sucesivos de mineralización que fueron controlados por una actividad discontinua de la cupla dextral. Este modelo estructural es similar a aquéllos propuestos para mineralizaciones de fluorita emplazadas en otros sectores del continente durante el mismo período, los que vinculan el control tectónico con la apertura del océano Atlántico sur. El registro del relleno hidrotermal permitió reconstruir la historia de apertura de las estructuras y puede usarse como un criterio efectivo de prospección y exploración. Las mayores concentraciones de mineral ocurren en las estructuras extensionales y en las flexiones dilatantes de las estructuras asociadas con la zona de cizallamiento principal NNE-SSO, que registran la secuencia mineralizada completa.

  16. Relaciones isotópicas Sm/Nd en rocas graníticas y miloníticas de Sierras Pampeanas del noroeste Argentino

    Directory of Open Access Journals (Sweden)

    Kawashita, K.

    2005-04-01

    Full Text Available The Velasco, Copacabana and Paimán Ranges in Sierras Pampeanas, are constituted mainly by paleozoic plutonic bodies of the Famatinian cycle (Huaco, Antinaco and Paimán and for mylonitic rocks (TIPA Shear Zone, originated as a consequence of dynamic events happening during the Upper Ordovician-Devonian. The last magmatic event of the area would probably have of devonian age (Granite San Blas. Model-ages of two stages were calculated based on 147Sm/144Nd relationships; the obtained values are closely grouped at around 1594 Ma. and the more plausible interpretation seems to be a reworking of an Early Proterozoic protolith.Las sierras de Velasco, Copacabana y Paimán, en el ambiente de Sierras Pampeanas, están constituidas principalmente por cuerpos plutónicos del Paleozoico inferior, relacionados con el ciclo Famatiniano (Granitos Huaco, Antinaco y Paimán y por rocas miloníticas (Faja Milonítica TiPA, originadas a partir de estos protolitos como consecuencia de eventos dinámicos acaecidos durante el Ordovícico superior-Devónico. El último evento magmático del área es de edad probablemente devónica (Granito San Blas. Se calcularon edades modelos de «dos estadios» en base a relaciones 147Sm/144Nd; los valores obtenidos se presentan estrechamente agrupadas en torno a 1594 Ma. y se interpretan a este basamento como un protolito del Proterozoico medio retrabajado.

  17. Volcanismo postorogénico en el extremo norte de las Sierras Pampeanas Orientales: Nuevos datos geocronológicos y sus implicancias tectónicas Postorogenic Volcanism in the Northern Boundary of the Eastern Sierras Pampeanas: Chronological Constraints and Their Tectonic Implications

    OpenAIRE

    PR Leal; LA Hartmann; JOS Santos; RC Miró; VA Ramos

    2003-01-01

    Este trabajo presenta nuevos datos geocronológicos del sector norte de las Sierras Pampeanas Orientales, en la provincia de Santiago del Estero. La geología regional del área está caracterizada por una serie de granitoides de edad proterozoica tardía a cámbrica temprana que son intruidos por rocas volcánicas supracorticales. Un cuerpo riodacítico, emplazado discordantemente en granitos deformados, asignado a la Dacita Los Burros, está densamente intruido por diques riolíticos, conocidos como ...

  18. The geodynamic evolution of the eastern Sierras Pampeanas based on geochemical, Sm-Nd, Pb-Pb and SHRIMP data

    DEFF Research Database (Denmark)

    Drobe, M; Lopez de Luchi, M; Steenken, A;

    2011-01-01

    Whole-rock geochemical analyses using major and trace elements in combination with the Sm–Nd and Pb–Pb isotope systems, together with SHRIMP age dating on metasedimentary rocks from the Sierras de Chepes, the Sierras de Co´rdoba, the Sierra Norte and the San Luis Formation in the Sierra de San Luis...

  19. La estructura ándica de las Sierras Pampeanas basada en los mecanismos focales de terremotos en su región noroeste

    Directory of Open Access Journals (Sweden)

    Patricia Alvarado

    2010-12-01

    Full Text Available El modelado de formas de ondas sísmicas de banda ancha de redes globales y de Chile para dos terremotos corticales moderados de la región noroeste de las Sierras Pampeanas ha permitido caracterizar sus mecanismos focales, profundidades hipocentrales y características sismotectónicas. El terremoto de magnitud Mw 5.8 del 28 de mayo de 2002 localizado en el flanco oriental de la sierra de Velasco y el terremoto Mw 6.2 del 7 de setiembre de 2004 con epicentro en la parte sudoccidental de la sierra de Ambato muestran profundidades focales someras de 10 y 8 km, respectivamente. Estos resultados combinados con la sismicidad histórica de la región permiten esbozar la estructura profunda de las Sierras Pampeanas en la región estudiada. El análisis sismológico efectuado en forma conjunta con la interpretación de la estructura superficial y los estudios neotectónicos previos permiten descartar mecanismos extensionales o de deformación mediante desplazamiento de rumbo como los responsables de la estructuración actual de las sierras de Ambato y Velasco. Se realiza la comparación entre el vector de velocidad de convergencia entre las placas de Nazca y Sudamericana, y los vectores relativos de velocidades de GPS en la región de estudio con la sumatoria del tensor momento sísmico para la mayor liberación de energía sísmica de sismos corticales ocurridos en la región en los últimos 30 años. Esta comparación predice una rotación horaria de 50º del eje de máxima compresión (eje P promedio respecto de la orientación hacia el noreste de la convergencia mencionada y muestra una importante partición de la deformación. Se interpreta que esta partición está controlada por la fábrica eopaleozoica del basamento, que ha regulado la orientación y vergencia de las fallas andinas.

  20. Pinturas rupestres y estructuras de piedra en las Sierras de Curicó (extremo noroccidental de Tandilia, Región Pampeana

    Directory of Open Access Journals (Sweden)

    Patricia Madrid

    2000-12-01

    Full Text Available En las Sierras de Curicó (también conocidas como de La China en el Pdo. de Olavarría, se han detectado pinturas rupestres en paredones y reparos de los afloramientos tabulares de cuarcita. Se trata de tres sectores con motivos lineales, geométricos, pintados en rojo. En el faldeo de la misma sierra, se localizaron dos estructuras pequeñas de piedra pircada de forma circular. En la cima de otro afloramiento rocoso, ubicado 500 m al oeste de estas estructuras, se halló una acumulación oval de piedras. En este trabajo se resumen las características del conjunto arqueológico y se presentan los resultados de los sondeos realizados en una de esas estructuras. Se examina la contemporaneidad entre las estructuras y las pinturas rupestres y su posible filiación tehuelche. Se comparan estas pinturas con otras manifestaciones similares de la Región Pampeana. Por último, se exploran aspectos simbólicos y religiosos de las sociedades pampeanas tardías.In the Curicó hills (also known as the La China hill, in the Olavarría district, rock art has been discovered on walls and in shelters in the quartzite tabular outcrops of the Balcarce Formation. The paintings are in three sectors and consist of lineal and geometrical motifs painted in red. On the slope of the hill, two stone circular structures were detected, and on the top of the opposite hill an oval stone structure was also found. In this article, the characteristics of this archaeological material are summarised and the results from test pits, excavated in one of these structures is presented. The contemporaneity among the findings is examined as well as its possible tehuelche affiliation. Finally, the symbolic and religion dimensions of the Late Pampean indigenous societies are explored.

  1. Geología y petrología del granito tres cerritos, extremo meridional de la sierra de Quilmes y su relación con el magmatismo devónico-carbonífero de las sierras Pampeanas

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    Ana E Acosta Nagle

    2014-09-01

    Full Text Available El Granito Tres Cerritos está ubicado en el extremo SE de la Sierra de Quilmes, en el departamento Santa María, provincia de Catamarca, en el ambiente morfoestructural de Sierras Pampeanas Septentrionales. El basamento metamórfico de la zona de estudio está constituido por esquistos de bajo y mediano grado metamórfico pertenecientes al Complejo Tolombón, que son afectadas por una faja de cizalla formada con anterioridad al emplazamiento del intrusivo. Localmente se produce metamorfismo de contacto con formación de porfiroblastos de cordierita y biotita. El granito Tres Cerritos aflora en dos sectores, uno de mayor extensión, de unos 6 km² de superficie, de forma elongada con su eje mayor de 4 km de rumbo submeridional y otro más pequeño, que aflora al oeste del área de estudio, de unos 1,9 Km de largo por 250 m de ancho, aproximadamente. Composicionalmente varía entre sienogranito y monzogranito y presenta tres facies: Porfírica biotítica, porfírica moscovítica y equigranular moscovítica. Geoquímicamente se define como un granito calco-alcalino y peraluminoso, con alto potasio. Según dataciones K/Ar este granito sería de edad carbonífera superior. Las características petrográficas, geoquímicas y geocronológicas del granito Tres Cerritos son similares a la de los intrusivos devónico-carboníferos de las Sierras Pampeanas de Catamarca, La Rioja, Córdoba y San Luis, por lo que el granito Tres Cerritos formaría parte de un evento magmático de gran extensión areal, post-orogénico o de intraplaca, que afectó a las Sierras Pampeanas durante el Devónico-Carbonífero.

  2. Análisis geoquímico-geocronológico de rocas granulíticas y calcosilicáticas de las Sierras Pampeanas Noroccidentales

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    AJ Toselli

    2003-12-01

    Full Text Available Las rocas calcosilicáticas y granulíticas, muestran tipologías diferentes en los sectores occidental y oriental de las Sierras Pampeanas Noroccidentales. Las asociaciones minerales difieren según el grado metamórfico y las composiciones químicas varían desde ricas en óxido de calcio a ricas en sílice; siendo diferentes de las anfibolitas. Las rocas calcosilicáticas en las Cumbres Calchaquíes, Aconquija y Ancasti muestran paragénesis con cuarzo, plagioclasa, clinozoicita, granate, hornblenda, titanita, diópsido, biotita y calcita; mientras que en la sierra de Quilmes, en facies granulita, se presenta hipersteno y escasa biotita. Ambas son diferentes de las rocas calcosilicáticas de la sierra de Fiambalá. Los datos geocronológicos obtenidos, permiten correlacionar al evento de muy bajo-bajo grado metamórfico de la Formación Puncoviscana, con edades de 530-568 Ma, con sus equivalentes más profundos en la sierra de Quilmes, representados por rocas calcosilicáticas de 571 Ma, granulitas con 480 Ma y las relacionadas con fenómenos anatécticos y graníticos con edades de 453 Ma (Granito Cafayate y 446 Ma (Loma Colorada, típicas para el Ciclo Famatiniano. Esto se reitera en la tonalita El Infiernillo, de 419 Ma, en las granodioritas sintectónicas de la Formación El Portezuelo, con 445 Ma; en el gneis de La Puntilla de Copacabana con 483 Ma y en el gneis de la sierra de Fiambalá con 440 Ma. Asimismo la faja de deformación de la sierra de Copacabana, con una edad de 388 Ma, se relaciona con los granitos de Zapata de 395 Ma, y los de La Punta, de 405 Ma y Señor de la Peña, 376 Ma, en la sierra de Velasco. Esto muestra que metamorfismo, deformación y magmatismo del Ciclo Famatiniano, se sobreimponen al Ciclo Pampeano.

  3. Estructura interna de la franja migmatítica del núcleo cristalino de las sierras Pampeanas septentrionales del Noroeste Argentino

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    Clara Eugenia Cisterna

    2010-03-01

    Full Text Available El Complejo Las Cañas en la sierra de Aconquija (Sierras Pampeanas Septentrionales, NO de Argentina está integrado por rocas del basamento cristalino, representadas por migmatitas y en menor proporción por esquistos, que se hallan como resisters en ellas. Las migmatitas varían desde metatexitas a diatexitas y muestran una foliación migmatítica, acompañada de pliegues intrafoliales formados bajo condiciones de elevado metamorfismo, con fusión parcial y anatexis. Un plegamiento posterior, en condiciones de elevada ductilidad, genera figuras de interferencia. Finalmente, se reconoce un episodio de deformación por cizallamiento dúctil - frágil que afecta parcialmente a las migmatitas, con sectores donde sus manifestaciones están más intensamente desarrolladas que en otros. Las observaciones de campo, estructurales y petrográficas permiten definir para estas rocas episodios de deformación pre, sin y post migmatíticos e interpretar que la evolución de este tramo del basamento cristalino del noroeste de Argentina se habría desarrollado en un cinturón móvil que integró el borde occidental del Gondwana, donde los episodios deformacionales reconocidos tienen correspondencia con el ciclo pampeano (550 - 500 Ma y la sobreimposición del ciclo famatiniano (500 - 440 Ma.

  4. Variaciones texturales y movilidad geoquímica asociadas a milonitización: la zona de cizalla del granitoide El Tigre, Sierra de Pie de Palo, Sierras Pampeanas Occidentales, San Juan Textural variations and chemical mobility during mylonitization: The El Tigre granitoid shear zone, Sierra de Pie de Palo, western sierras pampeanas, San Juan

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    Brígida Castro De Machuca

    2010-03-01

    Full Text Available Una faja de cizalla dúctil con foliación milonítica de dirección NEE y buzamiento al sudeste, afecta a un granitoide mesoproterozoico (Granitoide El Tigre: 31º31'30''S-68º15'12''O que forma parte del basamento cristalino de la Sierra de Pie de Palo, Sierras Pampeanas Occidentales. El análisis cinemático de la faja indica una componente principal de desplazamiento de rumbo con sentido de movimiento dextral. En el granitoide no deformado (protolito se preservan asociaciones minerales y texturas relícticas, ígneas y metamórficas, que son obliteradas por la deformación. La milonitización operó en un sistema abierto provocando la movilización (ganancia o pérdida de casi todos los elementos mayores y traza, incluyendo las tierras raras e isótopos de Rb/Sr y Sm/Nd. Los cambios químicos fueron controlados mayormente por transporte sintectónico de fluidos y por transformaciones mineralógicas producidas durante la milonitización (disminución del contenido de granate, biotita y minerales accesorios y neoformación de mica blanca en la matriz de las milonitas. Las variaciones isotópicas entre el protolito y las milonitas también serían resultado de la intervención de fluidos durante la deformación, con interacción variable entre fluido y rocas de caja. Los cambios texturales, mineralógicos y químicos experimentados por el granitoide durante la milonitización, permiten reconstruir su evolución tectono-metamórfica y las condiciones metamórficas imperantes. Las asociaciones minerales y microestructuras de deformación de las milonitas sugieren para la faja de cizalla del granitoide El Tigre condiciones propias de la facies de esquistos verdes, con temperaturas inferiores a los 400 °C. Este evento deformante tuvo lugar a los 473 ± 10 Ma durante la orogenia Famatiniana.A high-strain ductile shear zone trending NEE with southeasterly dipping mylonitic foliation, has been recognized affecting a Mesoproterozoic (ca. 1105 Ma

  5. Geoquímica de ríos de montaña en las Sierras Pampeanas: II. El río Los Reartes, sierra de Comenchingones, provincia de Córdoba

    OpenAIRE

    Andrea I. Pasquini; Karina L. Lecomte; Pedro J. Depetris

    2004-01-01

    Se analiza la hidrogeoquímica de la cuenca del río Los Reartes, un típico sistema hídrico montañoso de las Sierras Pampeanas de Córdoba. La litología dominante está representada por rocas graníticas y gnéisicas del basamento. La altitud máxima es de 2.400 m s.n.m. y la mínima de 670 m s.n.m. Las pendientes decrecen desde el 20% en las nacientes hasta inferiores al 6% en las áreas bajas. El clima es semiárido con una concentración estival de las precipitaciones. El pH de las aguas varía de 6,9...

  6. Volcanismo postorogénico en el extremo norte de las Sierras Pampeanas Orientales: Nuevos datos geocronológicos y sus implicancias tectónicas

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    PR Leal

    2003-12-01

    Full Text Available Este trabajo presenta nuevos datos geocronológicos del sector norte de las Sierras Pampeanas Orientales, en la provincia de Santiago del Estero. La geología regional del área está caracterizada por una serie de granitoides de edad proterozoica tardía a cámbrica temprana que son intruidos por rocas volcánicas supracorticales. Un cuerpo riodacítico, emplazado discordantemente en granitos deformados, asignado a la Dacita Los Burros, está densamente intruido por diques riolíticos, conocidos como Riolitas Oncán, ampliamente expuestos en la sierra de Ambargasta. Estas rocas volcánicas fueron emplazadas después de un importante episodio de deformación y exhumación del batolito, que ocurrió durante la orogenia pampeana. Datos geocronológicos, obtenidos de circones de la Dacita Los Burros por SHRIMP II, permitieron determinar que este cuerpo ha terminado su cristalización alrededor de 512 ± 3,5 Ma, con un evento hidrotermal superpuesto de 481 ± 1,5 Ma. Este efecto hidrotermal ha sido interpretado como asociado al emplazamiento de las Riolitas Oncán. Basados en datos estructurales, análisis geoquímicos y petrológicos previos y los nuevos datos, es posible interpretar la existencia de un arco magmático en las Sierras Pampeanas Orientales desarrollado durante el Precámbrico tardío al Cámbrico temprano, como resultado de una subducción hacia el este del terreno Pampia. La colisión de este terreno controló la deformación principal y el metamorfismo alrededor de 530 Ma, la exhumación del batolito y el emplazamiento de las series volcánicas ácidas aquí descriptas durante el Cámbrico inferior. A su vez, las edades modelos Sm-Nd compiladas para el centro de la Argentina y áreas adyacentes, junto con el análisis aquí presentado, muestran dos basamentos diferentes: edades modelo entre 1800 y 1300 Ma están concentradas al oeste de la zona de cizalla transbrasiliana, mientras que en el sector oriental edades modelos entre 2000

  7. Volcanismo postorogénico en el extremo norte de las Sierras Pampeanas Orientales: Nuevos datos geocronológicos y sus implicancias tectónicas Postorogenic Volcanism in the Northern Boundary of the Eastern Sierras Pampeanas: Chronological Constraints and Their Tectonic Implications

    Directory of Open Access Journals (Sweden)

    PR Leal

    2003-12-01

    Full Text Available Este trabajo presenta nuevos datos geocronológicos del sector norte de las Sierras Pampeanas Orientales, en la provincia de Santiago del Estero. La geología regional del área está caracterizada por una serie de granitoides de edad proterozoica tardía a cámbrica temprana que son intruidos por rocas volcánicas supracorticales. Un cuerpo riodacítico, emplazado discordantemente en granitos deformados, asignado a la Dacita Los Burros, está densamente intruido por diques riolíticos, conocidos como Riolitas Oncán, ampliamente expuestos en la sierra de Ambargasta. Estas rocas volcánicas fueron emplazadas después de un importante episodio de deformación y exhumación del batolito, que ocurrió durante la orogenia pampeana. Datos geocronológicos, obtenidos de circones de la Dacita Los Burros por SHRIMP II, permitieron determinar que este cuerpo ha terminado su cristalización alrededor de 512 ± 3,5 Ma, con un evento hidrotermal superpuesto de 481 ± 1,5 Ma. Este efecto hidrotermal ha sido interpretado como asociado al emplazamiento de las Riolitas Oncán. Basados en datos estructurales, análisis geoquímicos y petrológicos previos y los nuevos datos, es posible interpretar la existencia de un arco magmático en las Sierras Pampeanas Orientales desarrollado durante el Precámbrico tardío al Cámbrico temprano, como resultado de una subducción hacia el este del terreno Pampia. La colisión de este terreno controló la deformación principal y el metamorfismo alrededor de 530 Ma, la exhumación del batolito y el emplazamiento de las series volcánicas ácidas aquí descriptas durante el Cámbrico inferior. A su vez, las edades modelos Sm-Nd compiladas para el centro de la Argentina y áreas adyacentes, junto con el análisis aquí presentado, muestran dos basamentos diferentes: edades modelo entre 1800 y 1300 Ma están concentradas al oeste de la zona de cizalla transbrasiliana, mientras que en el sector oriental edades modelos entre 2000

  8. Geoquímica de ríos de montaña en las Sierras Pampeanas: II. El río Los Reartes, sierra de Comenchingones, provincia de Córdoba Geochemistry of mountain rivers in the Sierras Pampeanas: II. Los Reartes River, Sierra de Comenchingones, Province of Córdoba.

    Directory of Open Access Journals (Sweden)

    Andrea I. Pasquini

    2004-03-01

    Full Text Available Se analiza la hidrogeoquímica de la cuenca del río Los Reartes, un típico sistema hídrico montañoso de las Sierras Pampeanas de Córdoba. La litología dominante está representada por rocas graníticas y gnéisicas del basamento. La altitud máxima es de 2.400 m s.n.m. y la mínima de 670 m s.n.m. Las pendientes decrecen desde el 20% en las nacientes hasta inferiores al 6% en las áreas bajas. El clima es semiárido con una concentración estival de las precipitaciones. El pH de las aguas varía de 6,9 a 9,1 y los sólidos totales disueltos (STD oscilan entre 31 y 114 mg/l. La composición mayoritaria está caracterizada por HCO3- > Cl-+ SO42- y Na++ Ca2+ > K++ Mg2+. El pH, los STD y la alcalinidad aumentan aguas abajo, las aguas evolucionan de bicarbonatadas sódicopotásicas a cálcicas. Los elementos traza disueltos tienen concentraciones de 10-3a 10-7 veces la corteza continental superior. Los más solubles (Ca, Na, K, Mg, Ba, Sr presentan las mayores concentraciones disueltas, mientras los más inmóviles exhiben las más bajas. Los elementos de tierras raras (ETR exhiben concentraciones disueltas extremadamente bajas (ΣETR de 30 a 319 ng/l, controladas principalmente por el pH y por procesos de adsorción. La distribución anual irregular de las precipitaciones ejerce un control estacional sobre las concentraciones. La química de estas aguas evidencia un control climático y litológico. La condición climática semiárida determina una incipiente alteración química de los silicatos y la litología constituye el factor determinante que imprime una señal química común a las aguas de la región.We analyzed the hydrogeochemistry of Río Los Reartes, a typical high-altitude, mountainous drainage basin in the Sierras Pampeanas of Córdoba, Argentina. The dominant rocks in the area are granites and gneisses of the crystalline basement. Maximum and minimum altitudes are 2,400 m, and 670 m above sea level, respectively. The slopes

  9. Estructura interna de la franja migmatítica del núcleo cristalino de las sierras Pampeanas septentrionales del Noroeste Argentino Internal structure of the migmatitic belt in the crystalline core of the northern Sierras Pampenas Northwestern Argentina

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    Clara Eugenia Cisterna

    2010-03-01

    Full Text Available El Complejo Las Cañas en la sierra de Aconquija (Sierras Pampeanas Septentrionales, NO de Argentina está integrado por rocas del basamento cristalino, representadas por migmatitas y en menor proporción por esquistos, que se hallan como resisters en ellas. Las migmatitas varían desde metatexitas a diatexitas y muestran una foliación migmatítica, acompañada de pliegues intrafoliales formados bajo condiciones de elevado metamorfismo, con fusión parcial y anatexis. Un plegamiento posterior, en condiciones de elevada ductilidad, genera figuras de interferencia. Finalmente, se reconoce un episodio de deformación por cizallamiento dúctil - frágil que afecta parcialmente a las migmatitas, con sectores donde sus manifestaciones están más intensamente desarrolladas que en otros. Las observaciones de campo, estructurales y petrográficas permiten definir para estas rocas episodios de deformación pre, sin y post migmatíticos e interpretar que la evolución de este tramo del basamento cristalino del noroeste de Argentina se habría desarrollado en un cinturón móvil que integró el borde occidental del Gondwana, donde los episodios deformacionales reconocidos tienen correspondencia con el ciclo pampeano (550 - 500 Ma y la sobreimposición del ciclo famatiniano (500 - 440 Ma.The Las Cañas Complex located in Aconquija Range (Sierras Pampeanas Septentrionales is formed by rocks of the crystalline basement, mainly migmatites and, in smaller proportion, schists which are as resisters included in the migmatites. The migmatites range from metatexites to diatexites. They show a migmatitic foliation accompanied by intrafoliated folds generated under high metamorphic conditions, with partial melt and anatexis. A later superposed folding episode under high ductile conditions generated interference patterns. Finally a brittle-ductile shear episode involving the migmatites is recognized. It affects some portions more intensively than others; its

  10. Provencance of the late Proterozoic to early Cambrian metaclastic sediments ot the Sierra de San Luis (Eastern Sierras Pampeanas) and Cordillera Oriental, Argentina

    DEFF Research Database (Denmark)

    Drobe, M.; López de Luchi, M.; Steenken, A.;

    2009-01-01

    Provenance studies have been performed utilising major and trace elements, Nd systematics, whole rock Pb-Pb isotopes and zircon U/Pb SHRIMP data on metasedimentary rocks of the Sierra de San Luis (Nogolí Metamorphic Complex, Pringles Metamorphic Complex, Conlara Metamorphic Complex and San Luis F...

  11. Influencia de la tectónica preandina sobre la tectónica andina: el caso de la falla de Sierra Chica, Sierras Pampeanas de Córdoba

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    Roberto D Martino

    2012-06-01

    Full Text Available La falla de la Sierra Chica es una de las fallas inversas terciarias más importantes de las Sierras Pampeanas de Córdoba. La deformación frágil andina habría sido controlada parcialmente por estructuras previas como la foliación regional del basamento metamórfico proterozoico tardío-cámbrico. Otro control importante está dado por la tectónica extensional cretácica que produjo la apertura del océano Atlántico. La traza actual de la falla presenta tramos rectos, de alto ángulo (~50-60° y vinculados con depósitos cretácicos, que son interpretados como resultado de la reactivación de fallas directas previas, y tramos curvos de bajo ángulo (~30°, que no se asocian a ningún depósito en particular, que serían nuevas fallas inversas originadas por la tectónica terciaria. Una serie de fajas miloníticas antiguas, oblicuas al rumbo general, denominadas lineamientos Carapé, Quebrada Honda y Soconcho, producen la segmentación general de la falla de la Sierra Chica en tres grandes láminas de corrimiento. Durante la compresión terciaria, dichos lineamientos fueron reactivados como fallas de deslizamiento de rumbo dextral, que actuaron como rampas laterales mientras las láminas de corrimiento se desplazaban en sentido NNO (~N 330°. La forma convexa hacia el oeste se debería al efecto del fallamiento inverso de bajo ángulo asociado a la expansión de la parte frontal de la lámina de corrimiento. Las diferencias geobarométricas actuales (~5000 m entre los bloques exhumados a ambos lados de la falla de la Sierra Chica, a la latitud de Alta Gracia (31º 36' S, todavía reflejarían los efectos de la tectónica extensional cretácica, no compensados por la inversión terciaria.

  12. Texturas, inclusiones fluidas e isótopos estables envetas tensionales cuarzo-auríferas de cizallas paleozoicas, Sierras Pampeanas Orientales

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    Diana Mutti

    2009-06-01

    lafase final de la orogenia achaliana. El estudio avala también, la participaciónde aguas meteóricas durante el estadio4 final, debido entre otros,al alzamiento gradual de las Sierras Pampeanas desde el Devónico.

  13. La prolongación austral de las Sierras Pampeanas en la provincia de La Pampa: Evidencias geológicas y geofísicas

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    S. Delpino

    2005-09-01

    vergencia ONO. Las correlaciones estructurales, petrológicas y geofísicas halladas en la presente contribución, constituyen un aporte significativo a la hipótesis de continuidad de las Sierras Pampeanas Orientales en la porción central de la provincia de La Pampa.

  14. Las fajas de deformación dúctil de las Sierras Pampeanas de Córdoba: Una reseña general

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    RD Martino

    2003-12-01

    Full Text Available Se describen dieciseis fajas de deformación dúctil, reconocidas hasta el momento en las sierras de Córdoba, atendiendo a su extensión, límites, descripción general de las rocas de falla que la conforman, estructura interna y se da un significado tectónico que permite asignarlas a cuatro grupos. (1 Fajas transcurrentes dextrales paralelas al arco magmático precámbrico-cámbrico, relacionadas con la subducción pampeana durante el Cámbrico inferior. (2 Fajas de desenraizamiento del Orógeno Pampeano cámbrico, de naturaleza inversa, producidas por cizalla general convergente (transpresión, relacionadas con etapas póstumas colisionales del terreno Pampia contra el margen de Gondwana y con la subducción famatiniana. Su actividad deformacional se constriñe al lapso 490-470 Ma. (3 Fajas de imbricación regional con generación de cabalgamientos con un fuerte control reológico, ligadas a la contracción oclóyica (Ordovícico superior-Silúrico inferior, de naturaleza inversa, que determinan dominios de edad. De este a oeste, se definen: los dominios precámbrico-cámbrico (ígneo, cámbrico (metamórfico de grado medio a alto y ordovícico (metamórfico de grado medio a alto. Estas fajas estarían relacionadas con el acercamiento del terreno Cuyania al margen gondwánico, antes de su emplazamiento y colisión final en el Ordovícico superior. (4 Fajas contraccionales achalianas, con cinemáticas que indican movimientos inversos con una actividad deformacional que se extendería hasta el Devónico inferior, coincidente con la amalgamación definitiva del terreno Cuyania y con el cese del magmatismo famatiniano. Posteriormente, se registra una reactivación importante o el desarrollo de nuevas fajas de deformación alrededor del límite Devónico-Carbonífero, que serían la expresión de la orogenia Chánica producida por el emplazamiento del terreno Chilenia en el margen gondwánico.

  15. Evolución metalogenética de las Sierras Pampeanas de Córdoba y sur de Santiago del Estero: Ciclos prepampeano y pampeano

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    D. Mutti

    2005-03-01

    Full Text Available La hipótesis de evolución metalogenética de las Sierras Pampeanas de Córdoba y sur de Santiago del Estero propone cinco estadios metalogenéticos, de los cuales los dos primeros se abordan en este trabajo: el estadio 1 - vinculado con la apertura y expansión neoproterozoica del océano proto-atlántico - forma parte del ciclo extensional prepampeano. Durante el mismo se generaron depósitos volcanogénicos submarinos de Cu-Fe (Zn-Au-Ag-Co en basaltos, W (B-F-Zn en calizas y dolomías impuras y Fe en sedimentos silicoclásticos, y manifestaciones transicionales entre estos y MVT de Cu (Au-Ag y Pb-Zn (Ag-Cu-Au en calizas y dolomías impuras; a él se asocian concentraciones magmáticas de Cr en tectonitas del manto y de Fe-Ti en ultramafitas-mafitas de la zona de transición corteza-manto. En una reconstrucción global neoproterozoica, se establece la distribución de los depósitos prepampeanos y su relación espacial con los principales distritos volcanogénicos submarinos, SEDEX y MVT del océano protoatlántico. El ciclo compresional pampeano - famatiniano comprende dos estadios. El estadio metalogenético 2 (Neoproterozoico - Cámbrico temprano corresponde al ciclo orogénico pampeano, durante el cual se desarrollaron numerosas estructuras deformaciónales y magmatismo, generandose manifestaciones magmático-metamórficas de Fe-Ti en diques ultramáficos y máficos en tectonitas del manto, manifestaciones metasomáticas de Fe-Ti en rodingitas y pegmatitas portadoras de Be-Li-U-ETR, ademas de transformaciones (metamorfismo, deformación, removilización y recristalización en depósitos de Cr, Cu-Fe (Zn-Au-Ag-Co, W (B-F-Zn, Cu (Au-Ag, Pb-Zn (Ag-Cu-Au y Fe, que condicionan su respuesta magnética. Para los depósitos y manifestaciones de los estadios metalogenéticos descriptos se propone una distribución espacial según fajas vinculadas con megaestructuras activas a partir de los ciclos prepampeano y pampeano, y las asociaciones petrogen

  16. Variaciones texturales y movilidad geoquímica asociadas a milonitización: la zona de cizalla del granitoide El Tigre, Sierra de Pie de Palo, Sierras Pampeanas Occidentales, San Juan

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    Brígida Castro De Machuca

    2010-03-01

    Full Text Available Una faja de cizalla dúctil con foliación milonítica de dirección NEE y buzamiento al sudeste, afecta a un granitoide mesoproterozoico (Granitoide El Tigre: 31º31'30''S-68º15'12''O que forma parte del basamento cristalino de la Sierra de Pie de Palo, Sierras Pampeanas Occidentales. El análisis cinemático de la faja indica una componente principal de desplazamiento de rumbo con sentido de movimiento dextral. En el granitoide no deformado (protolito se preservan asociaciones minerales y texturas relícticas, ígneas y metamórficas, que son obliteradas por la deformación. La milonitización operó en un sistema abierto provocando la movilización (ganancia o pérdida de casi todos los elementos mayores y traza, incluyendo las tierras raras e isótopos de Rb/Sr y Sm/Nd. Los cambios químicos fueron controlados mayormente por transporte sintectónico de fluidos y por transformaciones mineralógicas producidas durante la milonitización (disminución del contenido de granate, biotita y minerales accesorios y neoformación de mica blanca en la matriz de las milonitas. Las variaciones isotópicas entre el protolito y las milonitas también serían resultado de la intervención de fluidos durante la deformación, con interacción variable entre fluido y rocas de caja. Los cambios texturales, mineralógicos y químicos experimentados por el granitoide durante la milonitización, permiten reconstruir su evolución tectono-metamórfica y las condiciones metamórficas imperantes. Las asociaciones minerales y microestructuras de deformación de las milonitas sugieren para la faja de cizalla del granitoide El Tigre condiciones propias de la facies de esquistos verdes, con temperaturas inferiores a los 400 °C. Este evento deformante tuvo lugar a los 473 ± 10 Ma durante la orogenia Famatiniana.

  17. Plutón La Costa, una expresión de magmatismo tipo-s en el sector noreste de la Sierra de Velasco, Sierras Pampeanas

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    P.H. Alasino

    2006-06-01

    Full Text Available Estudios combinados de petrología, química mineral y geoquímcia de roca total revelan la presencia de dos unidades graníticas peraluminosas con minerales aluminosos magmáticos tales como granate y mica blanca y la presencia distintiva de turmalina. Las evidencias aquí presentadas indican que estas dos facies, Anillaco y Anjullón, junto a la unidad peraluminosa Santa Cruz estudiada en trabajos previos, constituyen una serie de rocas co-sanguíneas, emplazadas en niveles someros de la corteza y las cuales conforman una unidad ígnea mayor denominada aquí plutón La Costa, la cual aflora en el sector noreste de la sierra de Velasco. La asociación mineral, la química mineral y la geoquímica de roca total permiten definir al plutón La Costa como un clásico granitoide tipo-S, derivado de una roca fuente de composición esencialmente pelítica. Diferentes estudios demuestran que la generación de granitoides tipo-S requiere de un alto gradiente geotérmico, por lo cual el plutón La Costa indica que la corteza en esta región soportó un notable calentamiento durante la generación del magma. Sin embargo, la ausencia de datos geocronológicos impide definir el evento tectomagmático que produjo el magma primordial de este plutón.

  18. Geoquímica de ríos de montaña en las Sierras Pampeanas: II. El río Los Reartes, sierra de Comenchingones, provincia de Córdoba

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    Andrea I. Pasquini

    2004-03-01

    Full Text Available Se analiza la hidrogeoquímica de la cuenca del río Los Reartes, un típico sistema hídrico montañoso de las Sierras Pampeanas de Córdoba. La litología dominante está representada por rocas graníticas y gnéisicas del basamento. La altitud máxima es de 2.400 m s.n.m. y la mínima de 670 m s.n.m. Las pendientes decrecen desde el 20% en las nacientes hasta inferiores al 6% en las áreas bajas. El clima es semiárido con una concentración estival de las precipitaciones. El pH de las aguas varía de 6,9 a 9,1 y los sólidos totales disueltos (STD oscilan entre 31 y 114 mg/l. La composición mayoritaria está caracterizada por HCO3- > Cl-+ SO42- y Na++ Ca2+ > K++ Mg2+. El pH, los STD y la alcalinidad aumentan aguas abajo, las aguas evolucionan de bicarbonatadas sódicopotásicas a cálcicas. Los elementos traza disueltos tienen concentraciones de 10-3a 10-7 veces la corteza continental superior. Los más solubles (Ca, Na, K, Mg, Ba, Sr presentan las mayores concentraciones disueltas, mientras los más inmóviles exhiben las más bajas. Los elementos de tierras raras (ETR exhiben concentraciones disueltas extremadamente bajas (ΣETR de 30 a 319 ng/l, controladas principalmente por el pH y por procesos de adsorción. La distribución anual irregular de las precipitaciones ejerce un control estacional sobre las concentraciones. La química de estas aguas evidencia un control climático y litológico. La condición climática semiárida determina una incipiente alteración química de los silicatos y la litología constituye el factor determinante que imprime una señal química común a las aguas de la región.

  19. Depósitos polimetálicos en el orógeno famatiniano de las Sierras Pampeanas de San Luis y Córdoba: fluidos, fuentes y modelos de emplazamiento Polymetallic deposits in the Famatinian orogen of the Sierras Pampeanas of San Luis and Córdoba: fluids, sources and emplacement model

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    D. Mutti

    2007-11-01

    Full Text Available El ciclo orogénico famatinano originó en las Sierras Pampeanas de San Luis y Córdoba un episodio mineralizante relacionado con cizallas de rumbo norte de primer orden y granitoides entre los ~ 385 y ~ 292 Ma. Este episodio definió dominios lineales polimetálicos de W, Ag, Pb, Zn, Au y metales asociados, en metamorfitas y minoritariamente en granitoides. En depósitos representativos de San Luis y Córdoba, los valores de d18Ofluido(H2O y dDfluido(H2O en silicatos, señalan para los fluidos mineralizantes, una filiación magmática y con aguas meteóricas evolucionadas. Las determinaciones de d34Sfluido (H2S en sulfuros sugieren la incorporación del azufre por termoreducción desde las metasedimentitas corticales. Las relaciones 208Pb/204Pb - 207Pb/204Pb - 206Pb/204Pb indican el aporte de Pb desde la corteza continental fanerozoica homogeneizada, aunque en La Fortuna (distrito Las Aguadas, La Aspereza (distrito San Martín y Fischer (distrito Cerro Áspero, se comprobó además, un componente mantélico. Las estructuras tensionales mineralizadas, con orientación mayoritaria entre 250º y 319º y geometría interna escalonada (en echelón, responden al modelo Riedel en zonas de cizalla simple. Estas estructuras secundarias se desarrollaron en un ambiente extensional frágil - dúctil a frágil y en un regimen transpresivo, durante un esfuerzo máximo principal s1 NO - SE y el alzamiento de la región. Las características halladas sugieren que el magmatismo famatiniano sinorogénico a posorogénico, ocasionó anomalías térmicas que propiciaron la circulación hidrotermal en sistemas convectivos. El flujo acuoso se encauzó principalmente, por la estructura de primer orden Tres Árboles y lineamientos secundarios. No se encontraron evidencias de que el magmatismo granítico hubiera contribuido significativamente con el aporte de azufre y elementos metálicos, al menos en este estilo de depósitos con marcado control estructural

  20. La faja metalogenética de San Luis, Sierras Pampeanas: mineralizacióny geocronología en el contexto metalogenético regional The San Luis Metallogenic Belt (SLMB,Sierras Pampeanas: mineralization and geochronology in a regionalmetallogenic framework

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    Nilda E. Urbina

    2009-06-01

    Full Text Available La faja metalogenética de SanLuis (FMSL, se halla directamente vinculada con la horizontalización de lazona de subducción entre los 27º y 33º S. Varios depósitos minerales sedisponen a lo largo de una faja de orientación ONO de 80 km de extensión. Seencuentran estrechamente vinculados al volcanismo de tipo calcoalcalino normala alto K y shoshonítico, el cual se inició a los 12-13 Ma en el oeste yfinalizó a los 1,9 Ma en el este de la faja indicando un rápido desplazamientodel frente volcánico. Los distritos La Carolina y Cañada Honda son los másimportantes desde le punto de vista metalogenético e incluyen depósitosepitermales de metales preciosos y porfíricos. La faja metalogenética reflejael extraordinario ensanchamiento del arco magmático a los 33º S y se asemeja ala situación del distrito Farallón Negro a los 27º S. Ambos tienencaracterísticas geoquímicas similares y fueron emplazados en las zonas detransición sur y norte del segmento de subducción horizontal (flat slab,donde cambia el ángulo de subducción. La dispocisión transversal al arcomagmático andino sugiere la existencia de zonas de debilidad estructural a lolargo de las latitudes de 27º y 33ºS que controlaron el ascenso de los magmas yla formación de mineralizaciones hidrotermales.The San Luis Tertiary Metallogenic Belt located in theSierras Pampeanas of San Luis is related with the subduction zone shallowingbetween 27º and 33º S. Several mineralizations of epithermal and porphyry typesare located along an 80 km WNWtrending belt. They are closely related to thenormal to high-K calc-alkaline and shoshonitic volcanism, which began at ~ 12-13 Ma in the west and ended at 1.9 Ma in the east indicating a swift eastwardshift of the volcanic front. La Carolina and Cañada Honda are the mostimportant metallogenic districts, including epithermal and porphyry deposits. The San Luis Metallogenic Belt reflects the extraordinary broadening of themagmatic arc at

  1. Evolución metalogenética de las Sierras Pampeanas de Córdoba y sur de Santiago del Estero: Ciclos prepampeano y pampeano Metallogenic evolution of the Sierras Pampeanas of Córdoba and south of Santiago del Estero: Prepampean and Pampean cycles

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    D. Mutti

    2005-03-01

    Full Text Available La hipótesis de evolución metalogenética de las Sierras Pampeanas de Córdoba y sur de Santiago del Estero propone cinco estadios metalogenéticos, de los cuales los dos primeros se abordan en este trabajo: el estadio 1 - vinculado con la apertura y expansión neoproterozoica del océano proto-atlántico - forma parte del ciclo extensional prepampeano. Durante el mismo se generaron depósitos volcanogénicos submarinos de Cu-Fe (Zn-Au-Ag-Co en basaltos, W (B-F-Zn en calizas y dolomías impuras y Fe en sedimentos silicoclásticos, y manifestaciones transicionales entre estos y MVT de Cu (Au-Ag y Pb-Zn (Ag-Cu-Au en calizas y dolomías impuras; a él se asocian concentraciones magmáticas de Cr en tectonitas del manto y de Fe-Ti en ultramafitas-mafitas de la zona de transición corteza-manto. En una reconstrucción global neoproterozoica, se establece la distribución de los depósitos prepampeanos y su relación espacial con los principales distritos volcanogénicos submarinos, SEDEX y MVT del océano protoatlántico. El ciclo compresional pampeano - famatiniano comprende dos estadios. El estadio metalogenético 2 (Neoproterozoico - Cámbrico temprano corresponde al ciclo orogénico pampeano, durante el cual se desarrollaron numerosas estructuras deformaciónales y magmatismo, generandose manifestaciones magmático-metamórficas de Fe-Ti en diques ultramáficos y máficos en tectonitas del manto, manifestaciones metasomáticas de Fe-Ti en rodingitas y pegmatitas portadoras de Be-Li-U-ETR, ademas de transformaciones (metamorfismo, deformación, removilización y recristalización en depósitos de Cr, Cu-Fe (Zn-Au-Ag-Co, W (B-F-Zn, Cu (Au-Ag, Pb-Zn (Ag-Cu-Au y Fe, que condicionan su respuesta magnética. Para los depósitos y manifestaciones de los estadios metalogenéticos descriptos se propone una distribución espacial según fajas vinculadas con megaestructuras activas a partir de los ciclos prepampeano y pampeano, y las asociaciones petrogen

  2. Evolución metalogenética de las Sierras Pampeanas de Córdoba y sur de Santiago del Estero: Ciclos famatiniano, gondwánico y ándico

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    D. Mutti

    2005-09-01

    Full Text Available Se propone la evolución metalogenética de las Sierras Pampeaneas de Córdoba y sur de Santiago del Estero en cinco estadios, de los cuales los dos primeros se expusieron en un trabajo anterior. El estadio metalogenético 3, que corresponde al segundo ciclo orogénico del Pampeano-Famatiniano, se caracterizó por la migración de fluidos hidrotermales y la generación y reactivación de estructuras. Durante el mismo sucedieron transformaciones en depósitos de Cr (Fe-Ti, Cu (Au-Ag, Pb-Zn (Ag-Cu-Au, Fe y Cu- Fe (Zn-Au-Ag-Co, y se originaron pegmatitas portadoras de Be-Nb-Ta-W-P-U-ETR, depósitos biextendidos de W-Bi (Mo-Cu-Sn- Zn-Au-B-F-Te y de U asociados a granitoides, depósitos metasomáticos de Fe-Cu (Ti-Au y vetas de Au (Cu-Zn-Pb-As y polimetálicas de Ag-Pb-Zn (V-Sn-Mn-Cd-Au-Cu-As-Bi-Sb-Co. Para este estadio se establece una correlación con depósitos en cinturones orogénicos. El estadio metalogenético 4, correspondiente al ciclo extensional gondwánico y vinculado con la apertura del rifting Atlántico, formó depósitos de Mn (Fe-F-Ba en vetas y de F (Fe-Mn en vetas asociados con granitos. El estadio metalogenético 5 se desarrolló durante el ciclo compresional Ándico y generó manifestaciones de Au epitermal y depósitos y manifestaciones de U-V (Mn-Fe en sedimentitas. Los sucesivos estadios de depositación y movilización de elementos metálicos definieron fajas mineralizadas que otorgan a este sector de las Sierras Pampeanas un carácter de dominio especializado en Cr, W, Fe, Cu, Zn, Pb, Ti, Au, Bi, Be, Li, U, Mn, F y B y subordinado en Sn, Mo, ETR, Ta, Nb, V, Cd, Ag, Sb, Co, P, As, S, Te, Se y Ba.

  3. Rasgos estructurales en la Sierra Pampeana de Velasco y alrededores a partir de los campos gravimétricos y magnetrométricos

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    Marcos A Sánchez

    2013-06-01

    Full Text Available La región que comprende la sierra de Velasco y el Sistema de Famatina, en el centro-oeste de la Provincia de La Rioja - Argentina, es un área clave para el estudio de la amalgamación de terrenos y tectónica vinculada con el levantamiento andino. En éste trabajo, se definen algunos rasgos de la estructura cortical de ésta región. Para ello, mediante la aplicación de métodos potenciales (gravedad y magnetismo, adecuadamente procesados e interpretados a través de técnicas semiautomáticas y de resalto de anomalías, se logró determinar: a una región que respondería a la zona de sutura entre los terrenos Famatina y Pampia y b fallas relacionadas al levantamiento de las sierras de Famatina y de Velasco. Los resultados anteriores se representan en una sección este - oeste en un modelo estructural de bloques de basamento entre Famatina y Velasco, hasta 12 km de profundidad. En él señalamos además la distribución de las fallas y sus buzamientos.

  4. Actualización en el límite entre sierras Pampeanas occidentales y Precordillera Oriental, en la provincia de San Juan

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    Juvenal J. Zambrano

    2008-03-01

    Full Text Available En este trabajo se analiza el sistema de fallamiento existente en la depresión tectónica de Tulum, ubicada en la parte este y sur de la provincia de San Juan, en el oeste árido de Argentina. El límite entre los dos sistemas morfoestructurales, uno la Precordillera Oriental y el otro el Sistema Pampeano Occidental ha sido establecido en trabajos anteriores, a lo largo del sistema de fallamiento de Tulum, que cruza a la depresión diagonalmente en dirección NNE. No obstante la disponibilidad de nueva información de sondeos eléctricos verticales y de algunas perforaciones para búsqueda de agua subterránea, efectuados al sur y al oeste del cerro Valdivia, permite señalar que hacia el suroeste de este núcleo de basamento metamórfico limitado en ambos flancos por fallas, el límite Sistema Pampeano y Precordillera se aproxima al cordón montañoso de sierra Chica de Zonda, continuando al sur en el cerro Salinas. De allí al SSO existen, en superficie, indicaciones de que el sistema de fallamiento continúa hasta el Montecito, donde el sistema pampeano de fallas queda interrumpido por la gran falla con actividad cuaternaria que sirve de límite oriental a la sierra de Las Peñas. El contacto entre ambos sistemas forma el extremo sur de la Precordillera Oriental en subsuelo. Este conocimiento estructural permite no solo ser aplicado a la prospección de agua sino también a la de hidrocarburos en la región.

  5. Manifestaciones geomorfológicas y geofísicas de una estructura geológica profunda al sur de la Sierra de Pie de Palo, Sierras Pampeanas

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    M. Patricia Martínez

    2008-06-01

    Full Text Available En el presente trabajo se vinculan las evidencias geomorfológicas y geofísicas con la existencia de una estructura emplazada en la corteza superior, ubicada al sur de la sierra de Pie de Palo y con similares dimensiones que ésta. A partir de valores de gravedad, se calculó una carta de anomalías de Bouguer, correspondiente a la sierra de Pie de Palo y zonas aledañas. Se aplicó el método de deconvolución de Euler, variando adecuadamente el ancho de ventana entre 20 y 35 km y con dos índices estructurales: 0,5 y 1. Las respuestas obtenidas con este método señalan en ambos casos una concentración de soluciones que se corresponden con rasgos estructurales reconocidos geológicamente como: la megafalla Desaguadero Bermejo; el borde oriental de la Precordillera; la megafractura de El Molle. Por otro lado, existe una gran acumulación de soluciones de forma trapezoidal al sur de la sierra de Pie de Palo. Estas fuentes responden a profundidades en su mayoría ubicadas entre 10 y 20 kilómetros, indicando una cuarta estructura profunda o alto de basamento. Las evidencias geomorfológicas encontradas en la región corroborarían la existencia de esta estructura en ascenso, sugerida por las sucesivas migraciones de los cauces de los ríos San Juan hacia el norte y Mendoza y Tunuyán hacia el sur, tanto en épocas prehistóricas como históricas. Este fenómeno podría compararse con el ocurrido durante el terremoto de 1977, con epicentro en la provincia de San Juan, el cual produjo un ascenso de la sierra de Pie de Palo de 1,20 metros.

  6. Depósitos polimetálicos en el orógeno famatiniano de las Sierras Pampeanas de San Luis y Córdoba: fluidos, fuentes y modelos de emplazamiento

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    D. Mutti

    2007-03-01

    Full Text Available El ciclo orogénico famatinano originó en las Sierras Pampeanas de San Luis y Córdoba un episodio mineralizante relacionado con cizallas de rumbo norte de primer orden y granitoides entre los ~ 385 y ~ 292 Ma. Este episodio definió dominios lineales polimetálicos de W, Ag, Pb, Zn, Au y metales asociados, en metamorfitas y minoritariamente en granitoides. En depósitos representativos de San Luis y Córdoba, los valores de d18Ofluido(H2O y dDfluido(H2O en silicatos, señalan para los fluidos mineralizantes, una filiación magmática y con aguas meteóricas evolucionadas. Las determinaciones de d34Sfluido (H2S en sulfuros sugieren la incorporación del azufre por termoreducción desde las metasedimentitas corticales. Las relaciones 208Pb/204Pb - 207Pb/204Pb - 206Pb/204Pb indican el aporte de Pb desde la corteza continental fanerozoica homogeneizada, aunque en La Fortuna (distrito Las Aguadas, La Aspereza (distrito San Martín y Fischer (distrito Cerro Áspero, se comprobó además, un componente mantélico. Las estructuras tensionales mineralizadas, con orientación mayoritaria entre 250º y 319º y geometría interna escalonada (en echelón, responden al modelo Riedel en zonas de cizalla simple. Estas estructuras secundarias se desarrollaron en un ambiente extensional frágil - dúctil a frágil y en un regimen transpresivo, durante un esfuerzo máximo principal s1 NO - SE y el alzamiento de la región. Las características halladas sugieren que el magmatismo famatiniano sinorogénico a posorogénico, ocasionó anomalías térmicas que propiciaron la circulación hidrotermal en sistemas convectivos. El flujo acuoso se encauzó principalmente, por la estructura de primer orden Tres Árboles y lineamientos secundarios. No se encontraron evidencias de que el magmatismo granítico hubiera contribuido significativamente con el aporte de azufre y elementos metálicos, al menos en este estilo de depósitos con marcado control estructural.

  7. Las fajas de deformación dúctil de las Sierras Pampeanas de Córdoba: Una reseña general Ductile deformation shear belts at Pampean Ranges near Córdoba, Central Argentina: A Review

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    RD Martino

    2003-12-01

    Full Text Available Se describen dieciseis fajas de deformación dúctil, reconocidas hasta el momento en las sierras de Córdoba, atendiendo a su extensión, límites, descripción general de las rocas de falla que la conforman, estructura interna y se da un significado tectónico que permite asignarlas a cuatro grupos. (1 Fajas transcurrentes dextrales paralelas al arco magmático precámbrico-cámbrico, relacionadas con la subducción pampeana durante el Cámbrico inferior. (2 Fajas de desenraizamiento del Orógeno Pampeano cámbrico, de naturaleza inversa, producidas por cizalla general convergente (transpresión, relacionadas con etapas póstumas colisionales del terreno Pampia contra el margen de Gondwana y con la subducción famatiniana. Su actividad deformacional se constriñe al lapso 490-470 Ma. (3 Fajas de imbricación regional con generación de cabalgamientos con un fuerte control reológico, ligadas a la contracción oclóyica (Ordovícico superior-Silúrico inferior, de naturaleza inversa, que determinan dominios de edad. De este a oeste, se definen: los dominios precámbrico-cámbrico (ígneo, cámbrico (metamórfico de grado medio a alto y ordovícico (metamórfico de grado medio a alto. Estas fajas estarían relacionadas con el acercamiento del terreno Cuyania al margen gondwánico, antes de su emplazamiento y colisión final en el Ordovícico superior. (4 Fajas contraccionales achalianas, con cinemáticas que indican movimientos inversos con una actividad deformacional que se extendería hasta el Devónico inferior, coincidente con la amalgamación definitiva del terreno Cuyania y con el cese del magmatismo famatiniano. Posteriormente, se registra una reactivación importante o el desarrollo de nuevas fajas de deformación alrededor del límite Devónico-Carbonífero, que serían la expresión de la orogenia Chánica producida por el emplazamiento del terreno Chilenia en el margen gondwánico.Sixteen ductile shear belts recognized at Pampean

  8. Cambios de gravedad de origen tectónico en la transición entre las Sierras Pampeanas Occidentales y la Precordillera Sanjuanina Gravity changes of tectonic origin in the transition between western Sierras Pampeanas and Precordillera of San Juan.

    Directory of Open Access Journals (Sweden)

    Francisco Ruiz

    2011-12-01

    Full Text Available El fenómeno sísmico está estrechamente ligado a cambios de gravedad producto de la deformación y de cambios de densidad en la corteza. Se ha establecido una red de control geodésico con el propósito de establecer relaciones espacio-temporales en la evolución del campo gravitatorio producido por actividad tectónica. La red está compuesta por 65 puntos fijos bien materializados y cubre un área de 3.500 km2 con la ciudad de San Juan en su centro. Diez años de mediciones periódicas han permitido evaluar las velocidades de variación de la intensidad del campo gravitatorio; éstas se ajustan razonablemente por el modelo estadístico de regresión lineal de las observaciones de la gravedad versus tiempo. Los resultados señalan el levantamiento actual de la Precordillera Oriental, que se refleja en aumentos de gravedad (g en las estaciones situadas al oeste del fallamiento Villicum-Ullum-Zonda y en la disminución de g al este de la estructura. identificamos tres segmentos activos: a la falla de La Laja con fuerte disminución de g, b el segmento Maradona-Cerro Bayo, con aumentos de g al oeste de la sierra Chica de Zonda y c una disminución de g en la falla de La Rinconada. Los datos muestran actividad tectónica en el sistema de fallas del Tulum que exhibe un gradiente en la dirección del lineamiento Cerro Valdivia-Cerro Barboza-Sierra de Pie de Palo que se incrementa hacia el este. Sus variaciones máximas negativas se observan al este del cerro Barboza. Mapas de anomalías magnéticas y gravimétricas señalan patrones en el basamento coincidentes con estas estructuras activas.Earthquake is closely tied up with gravity changes on the basis of crustal deformation and crustal density changes. A network of areal geodetic control was set up with the purpose of establishing space-time relations in the evolution of the gravity field produced by tectonic activity. The network is composed by 65 bench marks well materialized in the field, and

  9. Patrimonio arqueológico, preservación y turismo. El caso de las Sierras de Curicó (Sistema de Tandilia, Región Pampeana, Argentina)

    OpenAIRE

    Patricia Madrid; Victoria Pedrotta; Andrea Istillarte

    2014-01-01

    El propósito de este artículo es discutir los efectos positivos y negativos del uso de la localidad arqueológica Sierras de Curicó (partido de Olavarría, provincia de Buenos Aires, Argentina) en el marco de potenciales emprendimientos turísticos. El atractivo natural de este paisaje arqueológico conformado por pinturas rupestres, estructuras de piedra, un montículo rocoso y un alero, en las serranías bajas de Tandilia, ha concitado desde hace algunos años un uso recreativo espontáneo en un ár...

  10. Patrimonio arqueológico, preservación y turismo. El caso de las Sierras de Curicó (Sistema de Tandilia, Región Pampeana, Argentina

    Directory of Open Access Journals (Sweden)

    Patricia Madrid

    2014-06-01

    Full Text Available El propósito de este artículo es discutir los efectos positivos y negativos del uso de la localidad arqueológica Sierras de Curicó (partido de Olavarría, provincia de Buenos Aires, Argentina en el marco de potenciales emprendimientos turísticos. El atractivo natural de este paisaje arqueológico conformado por pinturas rupestres, estructuras de piedra, un montículo rocoso y un alero, en las serranías bajas de Tandilia, ha concitado desde hace algunos años un uso recreativo espontáneo en un área no planificada para su uso turístico. En efecto, al impacto natural creciente se suma la acción antrópica cada vez más frecuente, poniendo a la localidad arqueológica en situación de vulnerabilidad y riesgo de conservación. Esto se acentúa particularmente en el caso de las representaciones rupestres, que constituyen sectores de visibilidad regular y altamente sensibles a la atención del visitante. En este contexto, es primordial evaluar la preservación del paisaje arqueológico como un todo antes de considerar su inclusión en proyectos de desarrollo sustentable que incluyan actividades turísticas. Previo diagnóstico, se analizan las estrategias mas adecuadas para poner en valor las Sierras de Curicó como alternativas a un uso turístico convencional en el contexto de escasas o nulas posibilidades de regular medidas efectivas de protección del patrimonio local. Por último, se recomienda un plan de manejo y la no apertura del sitio al público.

  11. The Structure at Sierra Ambato, Catamarca, Argentina: A New Meteorite Impact Site?

    Science.gov (United States)

    Acevedo, R. D.; Rocca, M.; Alonso, R.; Rabassa, J.; Ponce, J. F.

    2012-09-01

    A new possible impact crater was discovered in Catamarca Province: the structure at Sierra Ambato (28º 03" 23.22” S, 66º 03" 11.06” W), located at Sierras Pampeanas (3,500 m.a.s.l). It has 1.0 km in diameter.

  12. El plutón de Serrezuela: Evento magmático del Carbonífero en el sector norte de la sierra de Pocho, Córdoba, República Argentina The Serrezuela Pluton: Carboniferous magmatic event in the northerm sector of the Sierra de Pocho, Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    GM Gómez

    2003-09-01

    . El plutón de Serrezuela de edad carbonífera (321+7,4 Ma y 303+2MA, K/Ar, representa uno de los pulsos magmáticos graníticos mas jóvenes en este sector de las Sierras Pampeanas Orientales. Este cuerpo posiblemente registre el final del ciclo magmático generador de los vecinos batolito de Achala y plutón de La Playa bajo un régimen colisional.The Serrezuela granite is located at the Sierra de Serrezuela in the northern Sierra de Pocho, northwest Córdoba. It is a 16 km2 body, divided into two sectors by metamorphic outcrops. Structurally it is confined by several fractures related to major N-S regional lineaments. The Serrezuela pluton is composed of two main facies: biotite + muscovite monzogranite (BMM, and biotite tourmaline monzogranite (BTM. Both facies are calcalkaline peraluminous, with minor occurrences of a metaluminous biotite aplite. The BTM overlies the BMM facies with sharp contact, in a layer-like occurrence. The Serrezuela granitic stock is characterized by the presence of miarolitic cavities and widespread tourmalinization. A late quartz vein of considerable dimensions intrudes at the pluton boundary. Major element geochemistry shows some dispersion, whereas trace elements show a trend from biotite + muscovite monzogranite toward biotite tourmaline monzogranite. All rocks are strongly differentiated with the biotite + muscovite monzogranite being the least evolved and the most areally extended unit. A liquid fractionation mechanism is proposed for the differentiation and emplacement of the biotite tourmaline monzogranite. Changes in the foliation direction of the country rock, the presence of banded plagioclase and miarolitic cavities, suggests that the Serrezuela pluton had a forced emplacement into the country rocks at shallow crustal depth, along preexisting lineaments. Serrezuela pluton, is a Carboniferous K/Ar age granite (321± 7.4 Ma and 303± 2 Ma. It represents one of the youngest granitic magma pulses of this sector of the Eastern

  13. El plutón de Serrezuela: Evento magmático del Carbonífero en el sector norte de la sierra de Pocho, Córdoba, República Argentina

    Directory of Open Access Journals (Sweden)

    GM Gómez

    2003-09-01

    . El plutón de Serrezuela de edad carbonífera (321+7,4 Ma y 303+2MA, K/Ar, representa uno de los pulsos magmáticos graníticos mas jóvenes en este sector de las Sierras Pampeanas Orientales. Este cuerpo posiblemente registre el final del ciclo magmático generador de los vecinos batolito de Achala y plutón de La Playa bajo un régimen colisional.

  14. Cargas subcorticales en el antepaís andino y la planicie pampeana: evidencias estratigráficas, topográficas y geofísicas

    Directory of Open Access Journals (Sweden)

    F.M. Dávila

    2005-12-01

    Full Text Available En la región sur de los Andes Centrales, la generación de espacios de acomodación en el antepaís ha sido explicada mediante la influencia de cargas supracorticales (apilamiento de escamas tectónicas y de cargas litostáticas. Estudios en la región de Sierras Pampeanas sugieren un patrón de subsidencia de longitud de onda regional (>500 km, difícilmente explicada por estas cargas generalmente asociadas a subsidencias de longitud de onda corta (<300 km. Se propone que los rasgos estratigráficoestructurales, topográficos y geofísicos en la región de Sierras Pampeanas y en la cuenca Chaco-paranaense pueden ser explicados mediante deflexiones inducidas por mecanismos subcorticales ocurridos en el manto astenosférico y/o la corteza inferior, como flujos astenosféricos termo-inducidos y/o eclogitización, respectivamente. Las cargas supracorticales se habrían superpuesto al fenómeno de subsidencia regional, solapando su influencia localmente.

  15. Análisis de subsidencia de la Cuenca de las Salinas, Sierras Pampeanas occidentales Subsidence analysis of the Las Salinas Basin, western Sierras Pampeanas

    Directory of Open Access Journals (Sweden)

    Edgardo A. Azeglio

    2008-06-01

    Full Text Available En el presente trabajo se ha evaluado la subsidencia total de la cuenca de Las Salinas mediante diagramas tiempo - profundidad, considerando la subsidencia inicial, por carga y termotectónica. También se calculó la velocidad de subsidencia interválica en función del tiempo geológico. El área en estudio se ubica aproximadamente entre los paralelos 31°17´S y 32°40´S y los meridianos 66°38´W y 67°48´W en las cercanías de la localidad de Marayes, en el sitio denominado cuenca de Las Salinas. Los diagramas tiempo - profundidad permitieron relacionar cambios en la velocidad de subsidencia de la cuenca durante el proceso distensivo del Mesozoico y el actualmente compresional a la cual esta sometida, obteniéndose valores concordantes con áreas circundantes. Como resultado del análisis se encontró que la velocidad de subsidencia inicial fue de 0,0017 mm/año en el Carbonífero, la que fue aumentando lentamente hasta alcanzar los 0,00875 mm/año en el Cretácico. Este incremento disminuye sensiblemente durante el Cretácico superior, para posteriormente incrementarse abruptamente en el Terciario (0,043 mm/año. Este régimen se mantiene durante el Plioceno a Mioceno, alcanzando valores promedios de 0,269 mm/año, culminando con valores de 0,0973 mm/año. De la comparación entre ambos diagramas de subsidencia se observan distintos ritmos de sedimentación entre el sector norte y sur de la cuenca que podría ser la consecuencia de un fallamiento en el basamento. La comparación de estos valores con los obtenidos en la cuenca de Beazley indican que si bien los valores de subsidencia inicial y ritmo de sedimentación fueron similares. El inicio de la subsidencia en la cuenca de Beazley, se produjo con posterioridad (en el Triásico. La componente termotectónica en ambas cuencas es similar a pesar que el gradiente térmico normal de la zona aumenta sensiblemente en dirección sur.In the present work the total subsidence of Las Salinas basin has been evaluated trough time-depth diagrams, were the initial subsidence by load and thermotectonics were analyzed. The subsidence interval velocity was also calculated in function of the geologic time. The area under study is limited by the geographic coordinates of 31°17´ and 32°40´S latitude and 66°38´ and 67°48´W longitude, in the neighborhood of Marayes locality, in Las Salinas basin. The time-depth diagrams discriminate velocity changes of the basin subsidence rate during the extensional tectonics, and the present day dominant compressional process. The calculated results are in agreement with other regional rates. The obtained rates were: An initial subsidence velocity of 0.0017 mm/year during the Carboniferous period. This velocity had a constant and slow increase during Triassic and early Cretaceous times reaching mean values of 0.00875 mm/year in this last stage. The subsidence rate sensibly decreases during the late Cretaceous, and most part of the Tertiary. Subsequently a sudden change is observed during Pliocene - Miocene times reaching average values of 0.269 mm/year, and ending with rates of 0.0973 mm/year. The time-depth diagrams also show different subsidence rates from the northern and the southern parts of the basin, which could be the consequence of active basement faults during sedimentation. The initial subsidence and sedimentation rates were similar when these results are compared with Beazley Basin data, but the beginning of subsidence in Beazley Basin was later (Triassic time. The thermotectonic subsidences in both basins are similar, although the normal geothermal gradient of the area increases sensibly to the south.

  16. Cargas subcorticales en el antepaís andino y la planicie pampeana: evidencias estratigráficas, topográficas y geofísicas Subcrustal loads in the Andean foreland and pampean plain: stratigraphic, topographic and geophysical evidence

    Directory of Open Access Journals (Sweden)

    F.M. Dávila

    2005-12-01

    Full Text Available En la región sur de los Andes Centrales, la generación de espacios de acomodación en el antepaís ha sido explicada mediante la influencia de cargas supracorticales (apilamiento de escamas tectónicas y de cargas litostáticas. Estudios en la región de Sierras Pampeanas sugieren un patrón de subsidencia de longitud de onda regional (>500 km, difícilmente explicada por estas cargas generalmente asociadas a subsidencias de longitud de onda corta (In the Central Andes, supracrustal tectonic loading has been extensively invoked to explain retroarc flexure and foreland basin subsidence, due to stacking of tectonic slivers and amplification by sedimentary loads. However, we present surface and subsurface stratigraphic data from the Sierras Pampeanas broken foreland that suggest a long-wavelength subsidence pattern (>500 km, which is difficult to explain with upper crustal loads that are generally associated with short wavelength (< 300 km subsidence. It is proposed that stratigraphic, structural, topographic and geophysical features in the Sierras Pampeanas region and Chaco-Paranense basin can be explained by flections driven by processes occurring in the asthenosphere and/or lower crust, like thermal-driven corner mantle flow and/or eclogitization, respectively. Short-wavelength flexure (<300 km driven by various factors enhances regional subsidence features.

  17. Variabilidad morfológica craneofacial en el valle inferior del Rio Negro: implicaciones para el análisis de la dinámica poblacional en nordpatagonia y en el sudeste de la Región Pampeana

    OpenAIRE

    Pérez, Sergio Iván; Barrientos, Gustavo

    2001-01-01

    Recientemente se propuso, en base a distintas líneas de evidencia arqueológica y bioarqueológica, que los grupos humanos que habitaron el Sudeste de la Región Pampeana en distintos momentos del Holoceno fueron poblaciones locales pertenecientes a metapoblaciones alocrónicas, con un rango de distribución geográfica desconocido, pero que probablemente abarcó regiones vecinas como el norte de la Pampa Húmeda, Pampa Seca, Sierras Centrales y el norte de Patagonia. Con el fin de poner a prueba tal...

  18. Análisis de subsidencia de la Cuenca de las Salinas, Sierras Pampeanas occidentales

    Directory of Open Access Journals (Sweden)

    Edgardo A. Azeglio

    2008-06-01

    Full Text Available En el presente trabajo se ha evaluado la subsidencia total de la cuenca de Las Salinas mediante diagramas tiempo - profundidad, considerando la subsidencia inicial, por carga y termotectónica. También se calculó la velocidad de subsidencia interválica en función del tiempo geológico. El área en estudio se ubica aproximadamente entre los paralelos 31°17´S y 32°40´S y los meridianos 66°38´W y 67°48´W en las cercanías de la localidad de Marayes, en el sitio denominado cuenca de Las Salinas. Los diagramas tiempo - profundidad permitieron relacionar cambios en la velocidad de subsidencia de la cuenca durante el proceso distensivo del Mesozoico y el actualmente compresional a la cual esta sometida, obteniéndose valores concordantes con áreas circundantes. Como resultado del análisis se encontró que la velocidad de subsidencia inicial fue de 0,0017 mm/año en el Carbonífero, la que fue aumentando lentamente hasta alcanzar los 0,00875 mm/año en el Cretácico. Este incremento disminuye sensiblemente durante el Cretácico superior, para posteriormente incrementarse abruptamente en el Terciario (0,043 mm/año. Este régimen se mantiene durante el Plioceno a Mioceno, alcanzando valores promedios de 0,269 mm/año, culminando con valores de 0,0973 mm/año. De la comparación entre ambos diagramas de subsidencia se observan distintos ritmos de sedimentación entre el sector norte y sur de la cuenca que podría ser la consecuencia de un fallamiento en el basamento. La comparación de estos valores con los obtenidos en la cuenca de Beazley indican que si bien los valores de subsidencia inicial y ritmo de sedimentación fueron similares. El inicio de la subsidencia en la cuenca de Beazley, se produjo con posterioridad (en el Triásico. La componente termotectónica en ambas cuencas es similar a pesar que el gradiente térmico normal de la zona aumenta sensiblemente en dirección sur.

  19. El basamento de la sierra de San Luis: Nuevas evidencias magnéticas y sus implicancias tectónicas

    Directory of Open Access Journals (Sweden)

    CJ Chernicoff

    2003-12-01

    Full Text Available Los mapas aeromagnéticos disponibles de las sierras de San Luis y Comechingones en el sector sudoriental de las Sierras Pampeanas de Argentina, permiten examinar las características geológicas y estructurales de las unidades metamórficas e intrusivas del basamento de la región. A través de la aplicación del filtro de continuación ascendente a los datos del campo magnético total reducido al polo, se ha podido observar la configuración profunda de las distintas unidades. Entre ellas se destaca la secuencia supracortical, en parte correspondiente a la Formación San Luis, que permite reconstruir en varios sectores de la región, en algunos casos subaflorante, una importante sucesión de rocas metasedimentarias de hasta 3 km de espesor, que es interpretada como perteneciente a depósitos de una cuenca de antepaís formada con posterioridad a la orogenia pampeana, alrededor de los 530 Ma. Se caracterizan las distintas unidades metamórficas e ígneas a partir de su señal magnética, y sobre esta base se presenta una sección estructural profunda, que sirve de base para proponer la evolución tectónica del basamento de este sector de las Sierras Pampeanas. Éste registra a partir de la orogenia pampeana la instalación de un arco magmático con su respectiva cuenca de trasarco durante el Cámbrico tardío y el Ordovícico temprano, los que son cerrados y deformados durante la colisión del terreno de Cuyania en el Ordovícico medio.

  20. Variabilidad morfológica craneofacial en el valle inferior del Rio Negro: implicaciones para el análisis de la dinámica poblacional en nordpatagonia y en el sudeste de la Región Pampeana

    Directory of Open Access Journals (Sweden)

    Pérez, Sergio Iván

    2001-01-01

    Full Text Available Recientemente se propuso, en base a distintas líneas de evidencia arqueológica y bioarqueológica, que los grupos humanos que habitaron el Sudeste de la Región Pampeana en distintos momentos del Holoceno fueron poblaciones locales pertenecientes a metapoblaciones alocrónicas, con un rango de distribución geográfica desconocido, pero que probablemente abarcó regiones vecinas como el norte de la Pampa Húmeda, Pampa Seca, Sierras Centrales y el norte de Patagonia. Con el fin de poner a prueba tales hipótesis, se diseñó una investigación orientada a establecer, en cada caso, el grado de similitud morfológica a nivel craneofacial (tamaño y forma, mediante análisis discriminante aplicado a variables Howellianas. En una primera etapa se analizaron muestras masculinas y femeninas provenientes del valle inferior del Río Negro (colección del Museo de La Plata; n= 133, de cronología desconocida, y muestras diacrónicas del Sudeste de la Región Pampeana, con cronología determinada radiocarbónicamente (n= 36. Los resultados preliminares muestran que: a gran parte de la variabilidad registrada en la muestra de Río Negro tiene su correlato en la registrada en la Región Pampeana, lo que sugiere una estrecha relación biológica entre los habitantes prehispánicos de estas dos regiones, y b la muestra del valle del Río Negro está probablemente integrada por individuos correspondientes a distintos momentos del Holoceno.

  1. Guide to Using Sierra

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Ryan Phillip [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Agelastos, Anthony Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, Joel D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

  2. El basamento de la sierra de San Luis: Nuevas evidencias magnéticas y sus implicancias tectónicas The basement of Sierra de San Luis: New magnetic evidence and tectonic implication

    Directory of Open Access Journals (Sweden)

    CJ Chernicoff

    2003-12-01

    Full Text Available Los mapas aeromagnéticos disponibles de las sierras de San Luis y Comechingones en el sector sudoriental de las Sierras Pampeanas de Argentina, permiten examinar las características geológicas y estructurales de las unidades metamórficas e intrusivas del basamento de la región. A través de la aplicación del filtro de continuación ascendente a los datos del campo magnético total reducido al polo, se ha podido observar la configuración profunda de las distintas unidades. Entre ellas se destaca la secuencia supracortical, en parte correspondiente a la Formación San Luis, que permite reconstruir en varios sectores de la región, en algunos casos subaflorante, una importante sucesión de rocas metasedimentarias de hasta 3 km de espesor, que es interpretada como perteneciente a depósitos de una cuenca de antepaís formada con posterioridad a la orogenia pampeana, alrededor de los 530 Ma. Se caracterizan las distintas unidades metamórficas e ígneas a partir de su señal magnética, y sobre esta base se presenta una sección estructural profunda, que sirve de base para proponer la evolución tectónica del basamento de este sector de las Sierras Pampeanas. Éste registra a partir de la orogenia pampeana la instalación de un arco magmático con su respectiva cuenca de trasarco durante el Cámbrico tardío y el Ordovícico temprano, los que son cerrados y deformados durante la colisión del terreno de Cuyania en el Ordovícico medio.The available aeromagnetic maps of the Sierras de San Luis and Comechingones in the south-eastern sector of the Sierras Pampeanas of Argentina, show the geologic and structural characteristics of the metamorphic and intrusive units of the basement of the region. Through the upward continuation filter applied to the magnetic data, it is possible to view the depth to the different units. Among them it stands out the supracrustal sequence partly equivalent to the San Luis Formation, interpreted as foreland basin

  3. Southern Sierra Fisher Conservation Area - Sierra Nevada [ds568

    Data.gov (United States)

    California Department of Resources — The Southern Sierra Fisher Conservation Area encompasses the known occupied range of the Pacific fisher in the Sierra Nevada. This consists of an elevational band...

  4. Fuertes paleosismos de intraplaca y sus retornos vinculados a la falla Las Lagunas, Sierras Pampeanas de Cordoba Strong intraplate paleoearthquakes and their recurrence related to Las Lagunas fault, Sierras Pampeanas of Cordoba

    Directory of Open Access Journals (Sweden)

    Guillermo L Sagripanti

    2011-03-01

    Full Text Available En la intraplaca argentina, a la latitud 33°S, región sur de la provincia de Córdoba, la presencia de morfologías superficiales y deformaciones en sedimentos sueltos cuaternarios hacen suponer que la actividad tectónica neógena tuvo continuidad en el Holoceno y que seguramente fue acompañada por la ocurrencia de paleoterremotos. Los objetivos del presente trabajo son, por medio de investigaciones paleosismológicas realizar la reconstrucción del registro de la sismicidad prehistórica de la región y una estimación del potencial sismogénico de una fuente, con probada actividad cuaternaria, que sean de base en la estimación del riesgo sísmico de la región. Se excavaron seis trincheras transversales a la traza de la falla Las Lagunas, en sedimentos de origen eólico, fluvial y lagunar, en las cuales se relevaron estructuras cosísmicas, deformacionales y de licuefacción, de escala mesoscópica. Los resultados obtenidos han permitido proponer un modelo de retrodeformación para la falla, calcular el período de recurrencia de fuertes terremotos que es del orden de 1,2 - 2,0 Ka, calcular la magnitud de algunos paleo-eventos, Ms > 6,6 y hacer una estimación de la magnitud del terremoto máximo.Evidences like landforms and deformations in loose quaternary sediments, in the argentinian intraplate, at latitude 33° S, southern part of the Cordoba province, suggest that the Neogene tectonic activity continues into the Holocene and certainly had been associated to strong paleoearthquakes. The objectives of this work are to make a reconstruction of the prehistoric seis-micity record of the region by paleoseismological investigations, and to estimate the seismogenic potential of a source with proven Quaternary activity, with the aim of setting the basis to estimate the seismic risk of the region. Six trenches were dug across the trace of the Las Lagunas fault, cutting eolian, fluvial, and lagoon sediments. In the sites, several coseismic deformation and liquefaction structures were observed at a mesoscopic scale. The results allowed the proposal of a retrodeformation model for the fault, calculating the period of recurrence of strong earthquakes, around of 1,2 - 2,0 Kyr. The magnitude of some paleoevents Ms > 6,6 and maximum earthquake were also estimated.

  5. Fuertes paleosismos de intraplaca y sus retornos vinculados a la falla Las Lagunas, Sierras Pampeanas de Cordoba

    Directory of Open Access Journals (Sweden)

    Guillermo L Sagripanti

    2011-03-01

    Full Text Available En la intraplaca argentina, a la latitud 33°S, región sur de la provincia de Córdoba, la presencia de morfologías superficiales y deformaciones en sedimentos sueltos cuaternarios hacen suponer que la actividad tectónica neógena tuvo continuidad en el Holoceno y que seguramente fue acompañada por la ocurrencia de paleoterremotos. Los objetivos del presente trabajo son, por medio de investigaciones paleosismológicas realizar la reconstrucción del registro de la sismicidad prehistórica de la región y una estimación del potencial sismogénico de una fuente, con probada actividad cuaternaria, que sean de base en la estimación del riesgo sísmico de la región. Se excavaron seis trincheras transversales a la traza de la falla Las Lagunas, en sedimentos de origen eólico, fluvial y lagunar, en las cuales se relevaron estructuras cosísmicas, deformacionales y de licuefacción, de escala mesoscópica. Los resultados obtenidos han permitido proponer un modelo de retrodeformación para la falla, calcular el período de recurrencia de fuertes terremotos que es del orden de 1,2 - 2,0 Ka, calcular la magnitud de algunos paleo-eventos, Ms > 6,6 y hacer una estimación de la magnitud del terremoto máximo.

  6. Sierra Structural Dynamics Theory Manual

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Garth M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-19

    Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Sierra/SD. For a more detailed description of how to use Sierra/SD , we refer the reader to Sierra/SD, User's Notes . Many of the constructs in Sierra/SD are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Sierra/SD are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature. This page intentionally left blank.

  7. Discriminación de rocas ultramáficas y su encajonante metamórfico, mediante el procesamiento de imágenes satelitales Landsat 7 ETM+, Sierra Chica, Córdoba Ultramafic rocks discrimination from country rocks, using Landsat 7 ETM+ image data processing, in the Sierra Chica, Córdoba

    Directory of Open Access Journals (Sweden)

    Patricia A Anzil

    2010-06-01

    Full Text Available En el marco de una investigación sobre la identificación y cartografía de rocas ultramáficas en la sierra Chica de Córdoba, se evalúan técnicas y estrategias de análisis y caracterización espectral de imágenes satelitales como recursos para detectar y delimitar estos cuerpos. Se utilizan además datos de campo y la ubicación de afloramientos ya reconocidos en campaña para cotejar los resultados que se obtienen del análisis de las imágenes. Se emplean imágenes satelitales Landsat-7 ETM+, recurriéndose a estrategias de procesamiento digital tales como la combinación de bandas, los cocientes de bandas y las clasificaciones espectrales, lográndose avanzar en el propósito planteado, a pesar de la cobertura vegetal y la escasa superficie de tales afloramientos. El área de estudio se ubica en las Sierras Pampeanas de Córdoba, entre la sierra Grande y sierra Chica, lugar donde afloran cuerpos ultramáficos, correspondientes a la faja ultramáfica oriental, intercalados en metamorfitas de grado medio a alto. De los procesos aplicados para el tratamiento digital, las clasificaciones con máxima probabilidad y paralelepípedos, son los que aportan los mejores resultados. Estos son consistentes con cuerpos ya reconocidos por otros medios.Techniques and strategies were developed in image analysis and spectral characterization in a reasearch to identify and map the ultramafic rocks and to detect and outline these bodies at Sierra Chica of Córdoba. Field data and specific location of these bodies were used to check the results obtained from the digital treatment. Landsat- 7 ETM+ image data are employed in digital processing, including band combination, band rationing and spectral classification to reach the purpose of this work, in spite of vegetal cover and reduced exposed area of these rocks. Ultramafic rocks, part of the "Eastern Belt", intercalates with intermediate to high grade metamorphic rocks, located in the Sierras Pampeanas of

  8. Edad y caracterización de una mica de litio asociada a un sistema de greisen en Mina la Rosario, Sierra de Fiambalá, Catamarca Age and characterization of a lithium mica associated with a greisen system in the Rosario Mine, Sierra de Fiambalá, Catamarca

    Directory of Open Access Journals (Sweden)

    Julio C. Avila

    2008-03-01

    Full Text Available En el presente trabajo se realiza el estudio mineralógico y se define la edad de una mica de litio obtenida en las salbandas de las vetas cuarzo portadoras de wolframita de mina La Rosario, ubicada en las proximidades del granito Ayacucho, Sierra de Fiambalá, Sierras Pampeanas Occidentales de la provincia de Catamarca. Esta especie mineral fue identificada a través de diferentes técnicas analíticas que incluyen determinaciones por difracción de rayos X, análisis químicos y por espectrometría infrarroja. Los resultados de los estudios indican que su estructura corresponde a una zinnwaldita y su composición química permite ubicarla dentro de la serie biotita-siderofilita-zinnwaldita-lepidolita. Las edades isotópicas obtenidas para el Granito Ayacucho (340 ± 8 Ma y esta mica hidrotermal (339 ± 8 Ma confirman una edad carbonífera para este intrusivo y la estrecha relación temporal con la mineralización hidrotermal asociada.This work deals with a mineralogical study and the age of a lithium mica obtained from the selvage of wolframite quartz veins from La Rosario mine, which crops out close to Ayacucho Granite, Sierra de Fiambalá, Sierras Pampeanas Occidentales of Catamarca province. This mineral species was identified through different analytical techniques that include X-ray diffraction, chemical analyses and infrared spectrometry analyses. The results of the studies indicate that its structure corresponds to zinnwaldite and its chemical composition allows locating it inside the biotite-siderophyllite-zinnwaldite-lepidolite series. The isotopic ages obtained for the Ayacucho granite (340 ± 8 Ma and this hydrothermal mica (339 ± 8 Ma confirm a Carboniferous age for this intrusive and the genetic link with hydrothermal mineralization.

  9. Ignimbritas riolíticas neoproterozoicas en la Sierra Norte de Córdoba: ¿evidencia de un arco magmático temprano en el ciclo Pampeano? Neoproterozoic rhyolite ignimbrites in the Sierra Norte de Córdoba: evidence of an early magmatic arc in the Pampean cycle?

    Directory of Open Access Journals (Sweden)

    EJ Llambías

    2003-12-01

    Full Text Available La Sierra Norte forma parte de las Sierras Pampeanas de Córdoba por lo cual las principales intrusiones graníticas y el metamorfismo están relacionadas al ciclo orogénico Pampeano. La mayor diferencia con las Sierras de Córdoba es que en Sierra Norte el grado metamórfico es bajo y las intrusiones son superficiales. La Sierra Norte está compuesta por pequeños afloramientos de metasedimentitas, plutones de granodiorita y granito y cuerpos subvolcánicos relacionados a los últimos estadios del batolito. En este trabajo describimos mantos de ignimbritas intercalados en los metaconglomerados de la Formación La Lidia. Las ignimbritas están moderadamente soldadas y está compuestas por aproximadamente 15 % de porfiroclastos de cuarzo, feldespato potásico y plagioclasa totalmente alterada. La pasta consiste de trizas vítreas devitrificadas. La edad U/Pb convencional en circones dio 584+22/-14 Ma y es interpretada como la edad de cristalización. Tanto las ignimbritas como la roca de caja han sido afectadas por un metamorfismo en facies prehnita-pumpellita que alteró la plagioclasa en zoicita, sericita y pumpellita. Las ignimbritas silícicas neoproterozoicas, conjuntamente con el batolito calcoalcalino que le suceden sugiere la existencia de un arco magmático asociado al margen continental activo de Gondwana. Este arco habría estado activo desde el Neoproterozoico hasta el Cámbrico, con una duración de más de 60 Ma. La correlación de las metasedimentitas y volcanitas neoproterozoicas con la Formación Puncoviscana es posible.The Sierra Norte belongs to the Sierras Pampeanas of Córdoba and like in the Sierras de Córdoba the main granitic intrusions, metamorphism and deformation are related to the Pampean orogenic cycle. The most important difference with Sierras de Córdoba is that Sierra Norte shows a weaker deformation and a lower grade metamorphism. Sierra Norte consists of small outcrops of metasedimentary rocks intruded by

  10. Estimación de la estructura cortical de velocidades sísmicas en el suroeste de la sierra de Pie de Palo, provincia de San Juan Estimation of the seismic velocity crustal structure in the southwest region of the Sierra de Pie de Palo southwest San Juan

    Directory of Open Access Journals (Sweden)

    Marcelo Perarnau

    2010-12-01

    Full Text Available En este trabajo se muestran resultados relacionados con la estructura de corteza en la región de la sierra de Pie de Palo perteneciente a las Sierras Pampeanas Occidentales a partir de funciones del receptor telesísmicas para la estación sismológica Coronel Fontana (31,605°S y 68,238°O. Estos resultados ponen de manifiesto evidencias de dos discontinuidades intracorticales a profundidades de 13 y 28 km aproximadamente y una discontinuidad más profunda cerca de 47 km de profundidad que correspondería al Moho. Los valores de contraste entre las velocidades de ondas P y S (Vp/Vs para estas discontinuidades son en general elevados. En particular, la región comprendida entre 13 y 28 km de profundidad muestra los valores más altos de Vp/Vs lo cual indicaría un mayor grado de fracturación o fallamiento para esta zona de la corteza. Los resultados indican una densificación de la corteza inferior.In this paper receiver function results beneath the seismic station Coronel Fontana (31,605°S and 68,238°W, in the western Sierras Pampeanas are shown. These results provide evidence for two intracrustal discontinuities at depths of 13 km and 28 km approximately and a deeper discontinuity near 47 km depth, which correlates with the Moho. Overall the ratio between the seismic velocities of P and S waves (Vp/Vs for these discontinuities are high. In particular, the region between 13 and 28 km depth shows the higher values of Vp/Vs, which is consistent with a higher degree of fracturing and faulting. The results also indicate a denser composition of the lower crust.

  11. Las metamorfitas de baja presión en la Sierra de Socoscora, San Luis, y sus implicancias regionales The low-pressure metamorphic sequence in the Sierra de Socoscora, San Luis, and their regional implications

    Directory of Open Access Journals (Sweden)

    Andrés Carugno Durán

    2012-06-01

    Full Text Available La secuencia metamórfica de alta temperatura y baja presión presente en la sierra de Socoscora está compuesta por esquistos con porfroblastos de cordierita y andalucita, esquistos con nódulos de sericita, esquistos cuarzo biotítico muscovíticos y anfibolitas. Todas estas rocas se encuentran en contacto tectónico con migmatitas y granitoides. Los aforamientos de esta secuencia esquistosa son saltuarios, van de unos pocos metros a algunos kilómetros cuadrados y, en algunos casos, se presentan como xenolitos en los granitoides. Esta secuencia metasedimentaria, con intercalaciones de metabasitas, presenta evidencias de al menos tres fases deformacionales (F1, F2 y F3, asociadas a una evolución metamórfica de baja presión. F1 se desarrolla conjuntamente con un metamorfismo M1 (Bt1 + Ms1, posteriormente crece cordierita estática, entre las fases F1 y F2, dando lugar a M2 (Crd + Bt2 + Qtz + Kfs, durante la fase F2 se alcanza el clímax térmico con la presencia de sillimanita (fibrolita (M3: Bt3+ Ms2 + Sil. Posteriormente, el crecimiento estático de andalucita, post F2, caracteriza a M4 (And + Ms3. Por último, durante F3 se produce el clivaje de crenulación S3. La presencia de abundantes rocas máficas y/o granitoides en la zona, podrían ser responsables de los altos gradientes que permitieron el desarrollo de las paragénesis descriptas. En otros sectores de Sierras Pampeanas se han reconocido rocas formadas en condiciones similares, asociadas a procesos asignados a las orogenias Pampeana y Famatiniana. La falta de datos geocronológicos no permite asignar con precisión las rocas estudiadas a una u otra etapa. Las rocas que se describen en este trabajo podrían corresponder a niveles de menor profundidad que los correspondientes a las migmatitas presentes en la región.The low-pressure high-temperature metamorphic sequence recognized in the Sierra de Socoscora is formed by schists with cordierite and andalusite porphyroblasts, schists

  12. A seismological and petrological crustal model for the southwest of the Sierra de Pie de Palo, province of San Juan

    Directory of Open Access Journals (Sweden)

    Brígida Castro de Machuca

    2012-06-01

    Full Text Available A seismic velocity analysis from teleseismic receiver functions recorded in the southwestern fank of the Sierra de Pie de Palo (Western Sierras Pampeanas, Argentina, is compared with seismic properties directly calculated from lithological composition. The seismological results show an upper layer located in the first 13 km depth. A deeper contrast in seismic velocities is found at a depth of 28 km; the petrological results indicate a composition compatible with observed greenschist and amphibolite facies mafic rocks up to this depth. The receiver function measurements at 13 km and 28 km depths could be interpreted as two potential décollement levels that might have favoring a mechanism to thicken the whole crust, which produces a receiver function Moho signal located at 47 km depth. In addition, the lower crust between 28 km and 47 km exhibits high seismic P-wave velocities and Vp/Vs ratio (> 1.80 that are representative of a densification consistent with upper amphibolite to granulite/ecoglite facies lithologies. Based on these results, the combined petrological and seismological analyses suggest the continuation of the same mafic-crust outcropping lithologies into the lower levels of the 47-km thickened crust, which could be part of the Pie de Palo Complex ophiolite belt or the Precordillera basement.

  13. Nuevos aportes a la historia natural de la mulita pampeana Dasypus hybridus (Mammalia, Dasypodidae

    Directory of Open Access Journals (Sweden)

    Agustín M. Abba

    2011-12-01

    Full Text Available En este trabajo se presentan nuevos aportes sobre la historia natural de la mulita pampeana Dasypus hybridus (Desmarest, 1804 (Mammalia, Xenarthra, Dasypodidae. Los estudios de campo fueron llevados a cabo en 100 ha de cuatro establecimientos agropecuarios de la provincia de Buenos Aires, Argentina. Durante tres años se realizó un muestreo estacional de armadillos por captura y liberación. Se obtuvieron datos de hábitos alimentarios, uso del espacio y del tiempo, comportamiento, termorregulación, datos poblacionales y morfológicos. Se realizaron 71 capturas. En la dieta el ítem principal registrado fue material vegetal, seguido por hormigas e insectos coleópteros; no se observó una diferencia estacional en los hábitos alimentarios. La actividad de las mulitas se concentra durante el día, existió una baja en la frecuencia de observación durante las estaciones frías (otoño e invierno. La mulita pampeana prefiere suelos húmicos, terrenos altos y pastizales densos y altos; asimismo seleccionan los montes para refugiarse. Son individuos asociales. La temperatura rectal mostró correlaciones positivas con la temperatura ambiente. La proporción de sexos fue cercana a uno y no se observó dimorfismo sexual. Los resultados obtenidos concuerdan parcialmente con lo observado para otras especies del género, destacando las tendencias observadas en los hábitos alimentarios y en la estrategia termorregulatoria. Este trabajo representa un aporte en varios aspectos de una especie poco estudiada en una zona bajo importantes presiones de uso y modificación de hábitat.

  14. Modeling interfacial fracture in Sierra.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Arthur A.; Ohashi, Yuki; Lu, Wei-Yang; Nelson, Stacy A. C.; Foulk, James W.,; Reedy, Earl David,; Austin, Kevin N.; Margolis, Stephen B.

    2013-09-01

    This report summarizes computational efforts to model interfacial fracture using cohesive zone models in the SIERRA/SolidMechanics (SIERRA/SM) finite element code. Cohesive surface elements were used to model crack initiation and propagation along predefined paths. Mesh convergence was observed with SIERRA/SM for numerous geometries. As the funding for this project came from the Advanced Simulation and Computing Verification and Validation (ASC V&V) focus area, considerable effort was spent performing verification and validation. Code verification was performed to compare code predictions to analytical solutions for simple three-element simulations as well as a higher-fidelity simulation of a double-cantilever beam. Parameter identification was conducted with Dakota using experimental results on asymmetric double-cantilever beam (ADCB) and end-notched-flexure (ENF) experiments conducted under Campaign-6 funding. Discretization convergence studies were also performed with respect to mesh size and time step and an optimization study was completed for mode II delamination using the ENF geometry. Throughout this verification process, numerous SIERRA/SM bugs were found and reported, all of which have been fixed, leading to over a 10-fold increase in convergence rates. Finally, mixed-mode flexure experiments were performed for validation. One of the unexplained issues encountered was material property variability for ostensibly the same composite material. Since the variability is not fully understood, it is difficult to accurately assess uncertainty when performing predictions.

  15. The Capilla del Monte pluton, Sierras de Córdoba, Argentina: the easternmost Early Carboniferous magmatism in the pre-Andean SW Gondwana margin

    Science.gov (United States)

    Dahlquist, Juan A.; Pankhurst, Robert J.; Rapela, Carlos W.; Basei, Miguel A. S.; Alasino, Pablo H.; Saavedra, Julio; Baldo, Edgardo G.; Murra, Juan A.; da Costa Campos Neto, Mario

    2016-07-01

    New geochronological, geochemical, and isotopic data are reported for the Capilla del Monte two-mica granite pluton in the northeastern Sierras de Córdoba. An Early Carboniferous age is established by a U-Pb zircon concordia (336 ± 3 Ma) and a Rb-Sr whole-rock isochron (337 ± 2 Ma). Zircon saturation geothermometry indicates relatively high temperatures (735-800 °C). The granites have high average SiO2 (74.2 %), Na2O + K2O (7.8 %), and high field-strength elements, high K2O/Na2O (1.7) and FeO/MgO ratios (5.1), with low CaO content (0.71 %). REE patterns with marked negative Eu anomalies (Eu/Eu* 0.14-0.56) indicate crystal fractionation, dominantly of plagioclase and K-feldspar, from a peraluminous magma enriched in F. Isotope data (87Sr/86Srinitial = 0.7086, ɛ Nd336 = -5.5 to -4.4 with T DM = 1.5 Ga, zircon ɛ Hf336 +0.8 to -6.1; mean T DM = 1.5 Ga) suggest a Mesoproterozoic continental source, albeit with some younger or more juvenile material indicated by the Hf data. The pluton is the easternmost member of a Carboniferous A-type magmatic suite which shows an increase in juvenile input toward the west in this part of the pre-Andean margin. The petrological and geochemical data strongly suggest a similar intraplate geodynamic setting to that of the nearby but much larger, Late Devonian, Achala batholith, although Hf isotope signatures of zircon suggest a more uniformly crustal origin for the latter. Further studies are required to understand whether these bodies represent two independent magmatic episodes or more continuous activity.

  16. CPAFFC Delegation Visits Sierra Leone and Cameroon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>At the invitation of the Sierra Leone-China Friendship Association (SLCFA) and the Ministry of Territorial Administration and Decentralization of Cameroon, a 14-member CPAFFC delegation headed by Wang Daoyu, vice chairman of the Standing Committee of the Shandong Provincial People’s Congress, paid a goodwill visit to Sierra Leone and Cameroon in early December 2005. In Sierra Leone Vice President Solomon Ekuma Berewa, President of the Parliament Edmond Cowan, and Vice Foreign Minister Mohamed Kamara, and in

  17. Evolución tectónica andina entre las Sierras de Hualfín, capillitas y extremo sur de Aconquija, provincia de Catamarca

    Directory of Open Access Journals (Sweden)

    Raúl Seggiaro

    2014-12-01

    Full Text Available Las Sierras Pampeanas septentrionales están integradas por bloques de basamento cristalino basculados por fallas de rumbo NE-SO, que forman parte del lineamiento de Aconquija o de Tucumán. Las unidades cenozoicas, dispuestas en los valles intramontanos que separan las sierras de Capillitas, Hualfín y Aconquija, presentan relaciones de inconformidad sobre el basamento y registran cuatro sucesivos eventos deformacionales andinos. El primer evento deformacional presenta estratos de sincrecimiento asociados a fallas normales en la Formación Hualfín. Durante el segundo evento, la Formación Hualfín fue intensamente plegada y erosionada previamente a la depositación del Complejo Volcánico Farallón Negro. El tercer evento, de carácter transtensivo, se registra en el Compelo Volcánico Farallón Negro con fallas normales y discordancias progresivas. Este evento es coincidente con la irrupción del vulcanismo en la cuenca. A los fines de analizar la cinemática de la cuarta y última etapa de deformación se realizaron mediciones de indicadores cinemáticos a lo largo de fallas regionales y estructuras menores, con resultados que reflejan desplazamientos dextrales transpresivos. Los desplazamientos correspondientes a esta etapa estarían asociados a la elevación de las sierras y el emplazamiento de cuerpos subvolcánicos, algunos de los cuales como los de cerro Atajo, Capillitas y Agua Rica entre otros, son de interés económico. La tectónica transpresiva, aún vigente, se registra en fallas activas asociadas a avalanchas y flujos de detritos provenientes de las laderas de las sierras.

  18. Eventos de avalanchas y represamientos reiterados de ocurrencia prehistórica en la cuenca del río Villavil, sierra de Aconquija, Andalgalá, Catamarca Avalanches and dammed valleys events of Prehistoric occurrence in the Villavil river basin, Sierra de Aconquija, Andalgalá, Catamarca

    Directory of Open Access Journals (Sweden)

    Aldo Luis Banchig

    2009-12-01

    Full Text Available Este trabajo presenta la existencia de un cuerpo sedimentario cuyos mecanismos depositacionales involucran procesos gravitacionales de gran envergadura, identificado como una avalancha de rocas (2,69 x10(9 m³, de carácter prehistórico con reactivaciones sucesivas, generado en la ladera oriental del cerro Zapallar (3.100 m s.n.m., en el extremo sur de la sierra del Aconquija (Sierras Pampeanas. Las múltiples reactivaciones de este depósito han generado reiterados represamientos en el río Villavil. La zona de estudio se emplaza en afloramientos de rocas ígneas graníticas del basamento y en proximidades de la intersección de dos grandes fallamientos regionales que, al parecer, han influido en la generación de estos eventos. Evidencias de actividad cuaternaria de los fallamientos regionales permiten deducir una posible sismogénesis asociada a estas estructuras, aunque esto no se correlaciona con la sismicidad histórica. La ocurrencia de colapsos sucesivos asociados a la oclusión reiterada del río Villavil, representa un riesgo potencial al desarrollo de la localidad de Villavil ubicada en la misma quebrada.The study reports reactivations of an ancient rock avalanche (2.69 x10(9 m³ generated in the eastern hillslope of Zapallar peak (3,100 m a.s.l. in the southern sector of Sierra del Aconquija (Sierras Pampeanas. Multiple events of the original deposit have generated several natural dams in the Villavil river. The area is located in basement outcrops constituted by granites crossed by two regional faults that favored the occurrence of these events. Evidence of Quaternary activity of these regional faults suggests a seismic triggering mechanism associated with these structures even though this hypothesis is not supported by seismic historical records. The occurrence of these successive collapses related to damned paleo-lakes along the Villavil river is a potential risk for the developiment of Villavil village located in this gully.

  19. Aspen Characteristics - Sierra State Parks [ds379

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands on lands administrated by the Sierra District, California...

  20. Tubulinosema pampeana sp. n. (Microsporidia, Tubulinosematidae), a pathogen of the South American bumble bee Bombus atratus.

    Science.gov (United States)

    Plischuk, Santiago; Sanscrainte, Neil D; Becnel, James J; Estep, Alden S; Lange, Carlos E

    2015-03-01

    An undescribed microsporidium was detected and isolated from the South American bumble bee Bombus atratus collected in the Pampas region of Argentina. Infection intensity in workers averaged 8.2 × 10(7)spores/bee. The main site of infection was adipose tissue where hypertrophy of adipocytes resulted in cyst-like body formation. Mature spores were ovoid and monomorphic. They measured 4.00 μm × 2.37 μm (fresh) or 3.98 μm × 1.88 μm (fixed). All stages were diplokariotic and developed in direct contact with host cytoplasm. Isofilar polar filament was arranged in 16 coils in one or, posteriorly, two layers. Coiling angle was variable, between perpendicular and almost parallel to major spore axis. Late meronts and sporogonial stages were surrounded by vesicles of approximately 60 nm in diameter. Based on both new and already designed primers, a 1827 bp (SSUrRNA, ITS, LSUrRNA) sequence was obtained. Data analyses suggest that this microsporidium is a new species of the genus Tubulinosema. The name Tubulinosema pampeana sp. n. is proposed. PMID:25637516

  1. Las metamorfitas de baja presión en la Sierra de Socoscora, San Luis, y sus implicancias regionales

    Directory of Open Access Journals (Sweden)

    Andrés Carugno Durán

    2012-06-01

    Full Text Available La secuencia metamórfica de alta temperatura y baja presión presente en la sierra de Socoscora está compuesta por esquistos con porfroblastos de cordierita y andalucita, esquistos con nódulos de sericita, esquistos cuarzo biotítico muscovíticos y anfibolitas. Todas estas rocas se encuentran en contacto tectónico con migmatitas y granitoides. Los aforamientos de esta secuencia esquistosa son saltuarios, van de unos pocos metros a algunos kilómetros cuadrados y, en algunos casos, se presentan como xenolitos en los granitoides. Esta secuencia metasedimentaria, con intercalaciones de metabasitas, presenta evidencias de al menos tres fases deformacionales (F1, F2 y F3, asociadas a una evolución metamórfica de baja presión. F1 se desarrolla conjuntamente con un metamorfismo M1 (Bt1 + Ms1, posteriormente crece cordierita estática, entre las fases F1 y F2, dando lugar a M2 (Crd + Bt2 + Qtz + Kfs, durante la fase F2 se alcanza el clímax térmico con la presencia de sillimanita (fibrolita (M3: Bt3+ Ms2 + Sil. Posteriormente, el crecimiento estático de andalucita, post F2, caracteriza a M4 (And + Ms3. Por último, durante F3 se produce el clivaje de crenulación S3. La presencia de abundantes rocas máficas y/o granitoides en la zona, podrían ser responsables de los altos gradientes que permitieron el desarrollo de las paragénesis descriptas. En otros sectores de Sierras Pampeanas se han reconocido rocas formadas en condiciones similares, asociadas a procesos asignados a las orogenias Pampeana y Famatiniana. La falta de datos geocronológicos no permite asignar con precisión las rocas estudiadas a una u otra etapa. Las rocas que se describen en este trabajo podrían corresponder a niveles de menor profundidad que los correspondientes a las migmatitas presentes en la región.

  2. Control estructural sobre el plutón Los Ratones y la mineralización de uranio en la sierra de Fiambalá, Sierras Pampeanas, Catamarca Structural control on the Los Ratones pluton and the uranium mineralization at the Fiambalá range, Sierras Pampeanas, Catamarca

    Directory of Open Access Journals (Sweden)

    Fernando Hongn

    2010-12-01

    Full Text Available El Granito Los Ratones, de edad carbonífera, está compuesto por dos facies principales: porfírica y equigranular. La mineralización de uranio alojada en la caja metamórfica sobre el borde NO del plutón se interpreta asociada a un greisen abierto rico en flúor vinculado con las facies equigranular. La cartografía detallada de la roca de caja del plutón, de parte de los bordes del intrusivo y de las manifestaciones uraníferas muestra un marcado control estructural sobre el emplazamiento del plutón, particularmente de la facies porfírica, y sobre la circulación de los fluidos mineralizantes. Cuatro juegos de fracturas participan de este control. Los dos principales de rumbo N y NE coinciden nítidamente con los bordes oeste y noroeste de la facies porfírica y con las expresiones más notables de la mineralización de uranio. El tercer juego corresponde a fracturas de rumbo E-O que son secundarias respecto a las anteriores considerando su frecuencia y longitud, al igual que el cuarto de rumbo NO. Los buzamientos de los juegos de fracturas N y NE son próximos a la vertical, orientación corroborada por estudios geofísicos en la zona dominada por las fracturas NE. Además de los rasgos mencionados, los diques básicos y ácidos que acompañan al plutón siguen preferentemente estas orientaciones. Las estructuras que controlan el magmatismo y la mineralización estarían vinculadas con un sistema de fallas meridianas con movimiento horizontal derecho principal y normal subordinado que parcialmente reactivaron heterogeneidades del basamento metamórfico, básicamente la foliación principal. Flexiones y quiebres a lo largo de estas estructuras generaron zonas dilatantes en las que se concentraron el magmatismo y la mineralización.The Carboniferous Los Ratones pluton is composed by two main facies: equigranular and porphyric. The uranium mineralization hosted by the metamorphic rock on the NW border of the pluton is related to a fluor- rich greisen related to the equigranular facies. The detailed mapping of the pluton host rock and the uranium mineralization shows a well-defined structural control on both the granite emplacement, particularly on the porphyric facies, and on the migration of the mineralized fluids. Four sets of fractures participate on this control. The two main with N and NE trends coincide clearly with the west and northwest border of the pluton as well as with the high-grade uranium manifestations. The third and fourth ones respectively corresponds to E-W and NW striking fractures, which are less developed in relation to the main fractures considering their frequency and size. Fractures of the four sets are high dipping close to vertical, attitude corroborated by geophysical studies in the area where the NE fractures are the best developed. In addition to the mentioned features, granite-related acidic and basic dikes follow mainly these orientations. The fracture sets seem to be related to a high-east dipping meridian fault system with right horizontal main movement component and subordinate normal displacement. These faults partially reactivated heterogeneities of the metamorphic rocks, mainly the dominant foliation. Changes on the strike of these fractures formed dilatant zones where magmatism and related mineralization were concentrated.

  3. Reading Comprehension Instruction Practices in Sierra Leone

    NARCIS (Netherlands)

    Hersbach, S.; Denessen, E.J.P.G.; Droop, W.

    2014-01-01

    Aim: In this study an attempt was made to give insight in the way reading comprehension is taught in Sierra Leone. Attention was paid to the didactical strategies and the materials used during reading comprehension instruction. Methodology: Primary school teachers in Sierra Leone (N=43) were observe

  4. Edad y caracterización de una mica de litio asociada a un sistema de greisen en Mina la Rosario, Sierra de Fiambalá, Catamarca

    Directory of Open Access Journals (Sweden)

    Julio C. Avila

    2008-03-01

    Full Text Available En el presente trabajo se realiza el estudio mineralógico y se define la edad de una mica de litio obtenida en las salbandas de las vetas cuarzo portadoras de wolframita de mina La Rosario, ubicada en las proximidades del granito Ayacucho, Sierra de Fiambalá, Sierras Pampeanas Occidentales de la provincia de Catamarca. Esta especie mineral fue identificada a través de diferentes técnicas analíticas que incluyen determinaciones por difracción de rayos X, análisis químicos y por espectrometría infrarroja. Los resultados de los estudios indican que su estructura corresponde a una zinnwaldita y su composición química permite ubicarla dentro de la serie biotita-siderofilita-zinnwaldita-lepidolita. Las edades isotópicas obtenidas para el Granito Ayacucho (340 ± 8 Ma y esta mica hidrotermal (339 ± 8 Ma confirman una edad carbonífera para este intrusivo y la estrecha relación temporal con la mineralización hidrotermal asociada.

  5. Stock monzogranítico El Chorro (Sierra de Ancasti, Catamarca: un ejemplo de magmatismo tipo S con granate ígneo

    Directory of Open Access Journals (Sweden)

    Juan A Dahlquist

    2011-06-01

    Full Text Available Las rocas graníticas ordovícicas de la sierra de Ancasti representan uno de los afloramientos más orientales del cinturón orogénico famatiniano de Sierras Pampeanas. Se describe un pequeño stock granítico (denominado El Chorro cuyo rasgo distintivo es la presencia de granate. Aunque el granate es un mineral accesorio poco común en rocas ígneas, su presencia es petrológicamente significativa. El Chorro es un monzogranito tipo S que contiene una inusual cantidad de granate magmático (2,8 % modal. Estudios combinados de petrología, química mineral y de geoquímica de roca total sugieren que se trata de un magma peraluminoso generado por la fusión parcial de rocas metasedimentarias, con la subsecuente formación de granate durante la cristalización. Los estudios realizados muestran que el granate cristalizó en equilibrio con otras fases minerales como biotita y muscovita. Cálculos geotermobarométricos revelan una temperatura de cristalización de 710-716 ºC y una presión de 3,8 + 0,8 kbar, indicando que el magma fue emplazado en la corteza media (~ 14 km con temperaturas de cristalización magmáticas medias a bajas.

  6. Estimación de la estructura cortical de velocidades sísmicas en el suroeste de la sierra de Pie de Palo, provincia de San Juan

    Directory of Open Access Journals (Sweden)

    Marcelo Perarnau

    2010-12-01

    Full Text Available En este trabajo se muestran resultados relacionados con la estructura de corteza en la región de la sierra de Pie de Palo perteneciente a las Sierras Pampeanas Occidentales a partir de funciones del receptor telesísmicas para la estación sismológica Coronel Fontana (31,605°S y 68,238°O. Estos resultados ponen de manifiesto evidencias de dos discontinuidades intracorticales a profundidades de 13 y 28 km aproximadamente y una discontinuidad más profunda cerca de 47 km de profundidad que correspondería al Moho. Los valores de contraste entre las velocidades de ondas P y S (Vp/Vs para estas discontinuidades son en general elevados. En particular, la región comprendida entre 13 y 28 km de profundidad muestra los valores más altos de Vp/Vs lo cual indicaría un mayor grado de fracturación o fallamiento para esta zona de la corteza. Los resultados indican una densificación de la corteza inferior.

  7. Eventos de avalanchas y represamientos reiterados de ocurrencia prehistórica en la cuenca del río Villavil, sierra de Aconquija, Andalgalá, Catamarca

    Directory of Open Access Journals (Sweden)

    Aldo Luis Banchig

    2009-12-01

    Full Text Available Este trabajo presenta la existencia de un cuerpo sedimentario cuyos mecanismos depositacionales involucran procesos gravitacionales de gran envergadura, identificado como una avalancha de rocas (2,69 x10(9 m³, de carácter prehistórico con reactivaciones sucesivas, generado en la ladera oriental del cerro Zapallar (3.100 m s.n.m., en el extremo sur de la sierra del Aconquija (Sierras Pampeanas. Las múltiples reactivaciones de este depósito han generado reiterados represamientos en el río Villavil. La zona de estudio se emplaza en afloramientos de rocas ígneas graníticas del basamento y en proximidades de la intersección de dos grandes fallamientos regionales que, al parecer, han influido en la generación de estos eventos. Evidencias de actividad cuaternaria de los fallamientos regionales permiten deducir una posible sismogénesis asociada a estas estructuras, aunque esto no se correlaciona con la sismicidad histórica. La ocurrencia de colapsos sucesivos asociados a la oclusión reiterada del río Villavil, representa un riesgo potencial al desarrollo de la localidad de Villavil ubicada en la misma quebrada.

  8. Ignimbritas riolíticas neoproterozoicas en la Sierra Norte de Córdoba: ¿evidencia de un arco magmático temprano en el ciclo Pampeano?

    Directory of Open Access Journals (Sweden)

    EJ Llambías

    2003-12-01

    Full Text Available La Sierra Norte forma parte de las Sierras Pampeanas de Córdoba por lo cual las principales intrusiones graníticas y el metamorfismo están relacionadas al ciclo orogénico Pampeano. La mayor diferencia con las Sierras de Córdoba es que en Sierra Norte el grado metamórfico es bajo y las intrusiones son superficiales. La Sierra Norte está compuesta por pequeños afloramientos de metasedimentitas, plutones de granodiorita y granito y cuerpos subvolcánicos relacionados a los últimos estadios del batolito. En este trabajo describimos mantos de ignimbritas intercalados en los metaconglomerados de la Formación La Lidia. Las ignimbritas están moderadamente soldadas y está compuestas por aproximadamente 15 % de porfiroclastos de cuarzo, feldespato potásico y plagioclasa totalmente alterada. La pasta consiste de trizas vítreas devitrificadas. La edad U/Pb convencional en circones dio 584+22/-14 Ma y es interpretada como la edad de cristalización. Tanto las ignimbritas como la roca de caja han sido afectadas por un metamorfismo en facies prehnita-pumpellita que alteró la plagioclasa en zoicita, sericita y pumpellita. Las ignimbritas silícicas neoproterozoicas, conjuntamente con el batolito calcoalcalino que le suceden sugiere la existencia de un arco magmático asociado al margen continental activo de Gondwana. Este arco habría estado activo desde el Neoproterozoico hasta el Cámbrico, con una duración de más de 60 Ma. La correlación de las metasedimentitas y volcanitas neoproterozoicas con la Formación Puncoviscana es posible.

  9. Sierra/SM theory manual.

    Energy Technology Data Exchange (ETDEWEB)

    Crane, Nathan Karl

    2013-07-01

    Presented in this document are the theoretical aspects of capabilities contained in the Sierra/SM code. This manuscript serves as an ideal starting point for understanding the theoretical foundations of the code. For a comprehensive study of these capabilities, the reader is encouraged to explore the many references to scientific articles and textbooks contained in this manual. It is important to point out that some capabilities are still in development and may not be presented in this document. Further updates to this manuscript will be made as these capabilites come closer to production level.

  10. El registro de la pequena edad de hielo en lagunas pampeanas

    Directory of Open Access Journals (Sweden)

    Cecilia Laprida

    2009-12-01

    Full Text Available Se conoce como Pequeña Edad de Hielo (LIA al episodio acontecido entre el siglo 16 y mediados del siglo 19, durante el cual el clima en Europa se tornó frío y ocasionalmente tormentoso. En ciertas partes de Europa, las observaciones instrumentales lo abarcan parcialmente, pero para Sudamérica no se dispone de registros instrumentales contemporáneos a dicho evento. Con el objetivo de obtener nuevas evidencias para el período comprendido por la Pequeña Edad de Hielo en la llanura pampeana, se analizaron testigos cortos de la laguna de Chascomús y de la laguna del Monte los que, de acuerdo a dataciones AMS, abarcan los últimos 500 años. Ambos testigos constan de tres secuencias granodecrecientes. El análisis del registro de la laguna de Chascomús ha permitido reconocer un período benigno desde fines del siglo 15 hasta alrededor del 1700, cuando se evidencia una retracción de la laguna que inaugura un período seco. Este episodio habría continuado por casi 150 años y se revierte alrededor de 1850, momento a partir del cual los eventos de excesos hídricos comenzaron a dominar el escenario pampeano. La base del testigo de la laguna de Monte fue datada en 1441-1494 AD. Si bien el modelo de edades para este testigo aún no ha podido ser bien establecido, los eventos de Chascomús y Monte podrían ser correlacionables y expresar tendencias seculares regionales de la humedad.

  11. ESTIMACIONES ACERCA DE LA SALUD DE POBLACIONES QUE OCUPARON LAS SIERRAS CENTRALES Y PLANICIES ORIENTALES (CÓRDOBA, ARGENTINA EN EL HOLOCENO TARDÍO: UNA APROXIMACIÓN DESDE LA ANTROPOLOGÍA DENTAL / Estimating Late Holocene health from Cordoba´s...

    Directory of Open Access Journals (Sweden)

    Claudina Victoria González

    2011-12-01

    Full Text Available El objetivo de este trabajo es analizar desde una perspectiva bioarqueológica las condiciones generales de salud de las poblaciones humanas que ocuparon la región austral de las Sierras Pampeanas en el Holoceno tardío (ca. 2500-400 años A.P., particularmente a través del estudio de bioindicadores dentales tales como hipoplasias del esmalte dental, abscesos y pérdidas dentales ante mortem. Se analizó una muestra de 80 individuos adultos de ambos sexos, procedentes de 48 sitios de toda la región. Se calcularon prevalencias por sexo, edad, cronología -Holoceno tardío inicial (ca. 2500-1500 años AP. y final (ca.1500-400 años AP-, así como sub-regiones geográficas - Sierras Chicas, Noreste, Noroeste, Llanura extraserrana, Sur y Traslasierra-. Posteriormente, se evaluó si las diferencias observadas eran significativas o no, mediante la aplicación del test de Chi-cuadrado (X2. Los resultados indican que las poblaciones asentadas en la región hacia momentos finales del Holoceno tardío habrían sufrido un deterioro en las condiciones generales de salud, principalmente los individuos adultos jóvenes y medios de toda el área, siendo mayor la intensidad en las sub regiones Noreste y Traslasierra.   Palabras clave: bioindicadores dentales, salud, región austral de las Sierras Pampeanas, Bioarqueología   Estimating Late Holocene health from Cordoba´s Central Highlands end Eastern Lowland populations (Argentina. A dental anthropology approach   Abstract The aim of this work is to study, from a bioarchaeological perspective, the health conditions of the populations that inhabited the southern portion of the Sierras Pampeanas region (Córdoba province by the Late Holocene (ca. 2500-400 years BP, through the analysis of three non-specific indicators of stress and infectious diseases: hypoplasia of dental enamel, abscesses, and antemortem teeth loss. The sample is composed by 80 adult individuals from 48 archaeological sites. We

  12. Actualización en el límite entre sierras Pampeanas occidentales y Precordillera Oriental, en la provincia de San Juan

    OpenAIRE

    Juvenal J. Zambrano; Graciela M Suvires

    2008-01-01

    En este trabajo se analiza el sistema de fallamiento existente en la depresión tectónica de Tulum, ubicada en la parte este y sur de la provincia de San Juan, en el oeste árido de Argentina. El límite entre los dos sistemas morfoestructurales, uno la Precordillera Oriental y el otro el Sistema Pampeano Occidental ha sido establecido en trabajos anteriores, a lo largo del sistema de fallamiento de Tulum, que cruza a la depresión diagonalmente en dirección NNE. No obstante la disponibilidad de ...

  13. Geocronología, paleoambientes y paleosuelos holocenos en la región pampeana

    Directory of Open Access Journals (Sweden)

    E. Fucks

    2007-09-01

    Full Text Available Las condiciones paleoambientales de la región pampeana durante el Holoceno, generaron diferentes superficies de estabilización del paisaje, permitiendo la formación de suelos tanto en ambientes de la llanura marina costera como en ambientes continentales. El análisis de diferentes perfiles geológicos en cuatro localidades y sus áreas de influencia en el NE y E de la provincia de Buenos Aires, permitieron identificar eventos pedogenéticos ubicados entre circa 4.500 años AP - 3.500 años 14C AP y circa 1.700 años 14C AP, en ambientes de la llanura marina costera y eventos pedogenéticos en planicies de inundación, ubicados cronológicamente con posterioridad a los circa 8.500- 8.000 años 14C AP, finalizando 2.000 años 14C AP. La cronología radiocarbónica permitió también: 1 ubicar cronológicamente el tope de la depositación del Miembro Guerrero de la Formación Luján dentro del Holoceno temprano (circa 8.500 años 14C AP; 2 ubicar el lapso máximo de depositación del sedimento denominado aluvio actual, desde el Holoceno tardío (circa 2.500 años 14C AP hasta los depósitos actuales donde se desarrolla un suelo muy incipiente; 3 datar eventos pedogenéticos dentro del aluvio actual en circa 1.700 años 14C AP; 4 estimar el retiro del máximo transgresivo del Holoceno y el comienzo de condiciones fluviales (circa 4.500 - 4.200 años 14C AP.

  14. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  15. Sierra Nevada snow melt from SMS-2

    Science.gov (United States)

    Breaker, L. C.; Mcmillan, M. C.

    1975-01-01

    A film loop from SMS-2 imagery shows snow melt over the Sierra Nevadas from May 10 to July 8, 1975. The sequence indicates a successful application of geostationary satellite data for monitoring dynamic hydrologic conditions.

  16. Running Parallel Discrete Event Simulators on Sierra

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jefferson, D. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-12-03

    In this proposal we consider porting the ROSS/Charm++ simulator and the discrete event models that run under its control so that they run on the Sierra architecture and make efficient use of the Volta GPUs.

  17. A strategic analysis of Sierra wireless

    OpenAIRE

    Durand, Juan-Carlos

    2005-01-01

    This paper performs a strategic analysis of Sierra Wireless, a leader in wireless data communications hardware and software. Sierra Wireless operates in the cellular modem industry and develops, manufactures, markets and supports wide-area wireless modems and enterprise software. The company faces challenges to its market leadership across its product lines due to commoditization of the market. It needs to change its differentiation strategy, develop lower-cost products and reduce its operati...

  18. El Granito Calasuya: un intrusivo alcalifeldespático postcolisional en el batolito de Sierra Norte-Ambargasta, Córdoba

    Directory of Open Access Journals (Sweden)

    Javier Elortegui Palacios

    2008-09-01

    Full Text Available La zona central del extenso batolito Sierra Norte-Ambargasta, en el bloque más oriental de las Sierras Pampeanas orientales, está representada por granitoides de arco magmático tipo I (granodioritas, monzogranitos, pórfidos dacíticos y riolíticos denominados serie La Isla - Cerro de los Burros, intruidos por cuerpos menores félsicos postcolisionales, químicamente más evolucionados (denominados unidades Puesto de Los Caminos y Cerro Baritina, todos pertenecientes al Neoproterozoico- Cámbrico inferior. Nueva información geológica y geoquímica de la región centro-oriental del mismo batolito permitió identificar un plutón de composición alcalifeldespática, denominado Granito Calasuya, el primero de esta naturaleza en el batolito. Su mineralogía distintiva la constituyen la composición albítica de la plagioclasa magmática (An < 6% molar, el elevado #Fe en las biotitas (0,97, la existencia de fluorita accesoria tardío magmática y el conspicuo proceso de albitización postmagmática. Su alto grado evolutivo se refleja en sus elevados tenores de SiO2 y sus bajos contenidos de CaO, MgO, TiO2, MnO y Fe2O3(t; también en las proporciones elevadas de Rb, Y y Th y en los contenidos deprimidos de Sr, Ba y Zr. Los valores de ΣETR son bajos, con perfiles asimétricos dominados por ETRL con anomalías positivas Ce/Ce* y negativas muy marcadas de Eu/Eu*. La relación Zr+Nb+Ce+Y versus Ga/Al distingue inequívocamente a este plutón como un granito tipo "I" altamente fraccionado. De acuerdo a ciertos patrones de campo y geoquímicos, el Granito Calasuya es comparable a los granitos epizonales postcolisionales de la unidad Puesto de los Caminos. Sin embargo, a pesar de estas evidencias, los patrones de ETR y su particular mineralogía accesoria revelan más afinidad con la unidad Cerro Baritina, representada por aplitas sienograníticas de edad cámbrica inferior, rocas que junto a otros granitoides fuertemente evolucionados han sido

  19. Las estructuras de la Cuenca de Bermejo y Sierra de Valle Fértil a partir de los métodos deconvolución de Euler y señal analítica

    Directory of Open Access Journals (Sweden)

    Federico Lince Klinger

    2008-06-01

    Full Text Available Se aplicaron técnicas de señal analítica y deconvolución de Euler a valores de anomalías de Bouguer de la cuenca de Bermejo y de la sierra de Valle Fértil, en el sector occidental de las Sierras Pampeanas. A partir de las soluciones encontradas por estas técnicas, se han interpretado la ubicación y profundidad de las fuentes causantes de anomalías, las que se vinculan con las estructuras geológicas que involucran al basamento. Con el objeto de verificar los resultados obtenidos y de minimizar las ambigüedades de los métodos potenciales, se preparó un modelo gravimétrico directo basado en un modelo estructural del área. A la respuesta gravimétrica de este modelo directo se le aplicó la técnica de señal analítica 2D, encontrándose soluciones que son consistentes con la profundidad y geometría de las fuentes previamente interpretadas, corroborando los resultados obtenidos.

  20. GPS Imaging of Sierra Nevada Uplift

    Science.gov (United States)

    Hammond, W. C.; Blewitt, G.; Kreemer, C.

    2015-12-01

    Recent improvements in the scope and precision of GPS networks across California and Nevada have allowed for uplift of the Sierra Nevada to be observed directly. Much of the signal, in the range of 1 to 2 mm/yr, has been attributed to lithospheric scale rebound following massive groundwater withdrawal in the San Joaquin Valley in southern California, exacerbated by drought since 2011. However, natural tectonic deformation associated with long term uplift of the range may also contribute to the observed signal. We have developed new algorithms that enhance the signal of Sierra Nevada uplift and improve our ability to interpret and separate natural tectonic signals from anthropogenic contributions. We apply our new Median Interannual Difference Adjusted for Skewness (MIDAS) algorithm to the vertical times series and a inverse distance-weighted median spatial filtering and Delaunay-based interpolation to despeckle the rate map. The resulting spatially continuous vertical rate field is insensitive to outliers and steps in the GPS time series, and omits isolated features attributable to unstable stations or unrepresentative rates. The resulting vertical rate field for California and Nevada exhibits regionally coherent signals from the earthquake cycle including interseismic strain accumulation in Cascadia, postseismic relaxation of the mantle from recent large earthquakes in central Nevada and southern California, groundwater loading changes, and tectonic uplift of the Sierra Nevada and Coast Ranges. Uplift of the Sierra Nevada extends from the Garlock Fault in the south to an indefinite boundary in the north near the latitude of Mt. Lassen to the eastern Sierra Nevada range front in Owen's Valley. The rates transition to near zero in the southern Walker Lane. The eastern boundary of uplift coincides with the highest strain rates in the western Great Basin, suggesting higher normal fault slip rates and a component of tectonic uplift of the Sierra Nevada.

  1. Miracle Boy of Sierra Vista

    Institute of Scientific and Technical Information of China (English)

    Deborah; Morris; 郗莱仁

    1998-01-01

    Sierra Vista是美国亚利桑那州的一个偏僻的小镇。1990年11月12日,这里发生了一桩震惊全美的故事。 笔者的一位友人读罢此文,认为这是让人心跳的一场“劫后余生”。 文章的开头,展示了一幅温馨的家庭生活图: 11月12日这一天,正值美国的Veterans Day(退伍军人节),学校放假。Amanda,两个小孩的母亲,决定陪同她的朋友Lyne Jackson去Tucson,而她的两个小孩,Nicole,12岁,Justin,8岁,暂时由Lyne的父母照看。Nicole,Justin和Lyne的9岁的小孩Keith等一起在外面戏耍。 “劫难”的到来总是那么猝不及防: Suddenly, Keith burst inside. "Grandma, Justin’s hurt!" Keith spoke in a frightened, breathless voice,"Hurry!" 当祖母和Keith赶到出事现场时,见到的是一场惨祸; Justin was sprawled (四肢摊开躺着) on his back on the ground, his handsclutching(抓住) at a 5/8-inch-thick threaded steel rod(螺纹钢棒) buried deep in his stomach! 惨祸是如何发生的呢?原来: Justin and Keith had scaled(攀上) the magnolia (木兰树) ’s branches, then triedto leap onto the roof of the house. But Justin slipped on the shingles (屋顶板)and slidoff feet-first, plummeting (骤然跌下) 12 feet onto the

  2. The Special Court for Sierra Leone

    DEFF Research Database (Denmark)

    Damgaard, Ciara Therése

    2004-01-01

    The focus of this article is the Special Court for Sierra Leone and the extent to which it can be said that the Special Court has already challenged, or will, in the future, challenge the tradition of impunity for gender-based crimes. In this regard, an analysis is undertaken of the Special Court......'s Statute, Rules of Procedure and Evidence and practice to date, in order to determine its treatment of gender-based crimes and whether it can be said that the Special Court for Sierra Leone challenges the tradition of impunity for gender-based crimes. Udgivelsesdato: december 2004...

  3. Especificidade de Puccinia pampeana a cultivares de Capsicum spp. e outras solanáceas Specificity of Puccinia pampeana to Capsicum spp. cultivars and other solanaceous plants. Summa Phytopathologica

    Directory of Open Access Journals (Sweden)

    Martha Maria Passador

    2009-02-01

    Full Text Available A ferrugem de espécies de Capsicum spp. (pimenta e pimentão, é causada pelo fungo Puccinia pampeana, pode causar perdas totais em plantios de diversas espécies de Capsicum, onde preodminam temperaturas ao redor de 21ºC. Esta ferrugem, mesmo sendo específica do gênero Capsicum, e mesmo muitas espécies dentro deste gênero sendo suscetíveis, algumas apresentam reação de hipersensibilidade. Foi o caso de Capsicum annuum (pimenta cv. Cayenne e C. chinense (pimenta cv. Habañero, que após a formação dos espermogônios (11 dias, apresentou manchas necróticas na região periférica aos espermogônios, aos 15 dias após a inoculação, não havendo evolução da infecção. Também foi observada reação de hipersensibilidade, de forma mais moderada em folhas C. annuum (pimenta serrano e C. baccatum (chapéu-de-frade. Com relação às outras solanáceas inoculadas (jiló e berinjela não foram observados os sintomas e sinais da infecção.The Capsicum spp. (pepper and green pepper rust is caused by the fungus Puccinia pampeana. This is an important disease in these crops which may cause complete losses in crops of several species of Capsicum. Although specific to the genus Capsicum, and despite the fact that many species within this genus are susceptible to rust, some of them have shown a hypersensitivity reaction. That was the case with Capsicum annuum (Cayenne pepper and C. chinense (datil pepper, which, after spermogonia formation (11 days, showed necrotic spots in the peripheral region of the spermogonia 15 days after inoculation, without evolution of the infection. A milder hypersensitivity reaction was also observed only in leaves of C. annuum (chili pepper and C. baccatum ("chapéu-de-frade". With regard to other solanaceous plants inoculated ("jiló" and eggplant, no symptoms or signs of infection were observed.

  4. NATURAL RESOURCE MANAGEMENT IN THE SIERRA OF SONORA UNDER THE SCHEME UMAFOR. CASE STUDY: SIERRA ALTA AND SIERRA LA MADERA

    Directory of Open Access Journals (Sweden)

    Hugo Silva-Kurumiya

    2011-05-01

    Full Text Available This paper shows the use and value of natural resources from a social, sustainable and legal perspective, under the scheme of Sustainable Forest Management Units (UMAFOR by its Spanish acronym. Two participatory workshops were carried out in March 2010, one in UMAFOR Sierra La Madera and another in UMAFOR Sierra Alta, belonging to the Sierra de Sonora. An adaptation of “Problems, Causes and Consequences” of Ramírez-García (2004 methodology was used to discuss issues such as conservation, productive activities, society, laws, research and support programs. The objective was to analyze challenges and opportunities in the Sierra de Sonora under this management scheme. The ratting of natural resource for inhabitant and producers was documented based in ecosystems type and its value for use. Economic value was the most important for productive and non productive use; however, there are opportunities to transit from traditional to sustainable activities. Local producers are interested in linking whit research centers and consultants to get support for diversification of productive activities. It is possible to have changes according to sustainable development; UMAFOR is an alternative to achieve those changes.

  5. The Cora: People of the Sierra Madre.

    Science.gov (United States)

    Lane, Sarah; And Others

    This text explores an isolated and indigenous people who live in the Sierra Madre Occidental in Mexico. Isolation has allowed the Cora Indians to maintain their traditional customs to a much greater extent than many other groups of Native Americans. The historical and geographical contexts of the Cora are presented in this curriculum resource.…

  6. Registro de Nephridiophaga sp. (Protista: Nephridiophagidae en Apis mellifera (Hymenoptera: Apidae del Sur de la región Pampeana

    Directory of Open Access Journals (Sweden)

    Santiago PLISCHUK

    2011-01-01

    Full Text Available Durante estudios prospectivos tendientes a la detección de protistas asociados a ápidos en la región Pampeana, se observó la presencia de esporos ovales bicóncavos y grupos de esporos (cúmulos en los túbulos de Malpighi de abejas de Dufaur, partido de Saavedra, sudoeste de la provincia de Buenos Aires. Los esporos maduros midieron 4,8 ± 0,05 x 2,4 ± 0,03 μm y la carga (intensidad promedió 5,71 ± 1,49 x 106 esporos/abeja. Las detecciones se efectuaron entre julio y octubre de 2006 y la prevalencia en las colmenas positivas osciló entre 1 y 16,7 %. Las características morfológicas de los esporos, el lugar de desarrollo y la especie huésped involucrada sugieren que el microorganismo en cuestión, pertenece al género Nephridiophaga y sería N. apis Ivanić, especie tipo cuyo conocimiento es extremadamente limitado. El hallazgo constituye el primer registro de un nefridiofágido asociado a A. mellifera fuera del continente europeo.

  7. A seismological and petrological crustal model for the southwest of the Sierra de Pie de Palo, province of San Juan Modelo cortical sismológico y petrológico para el sudoeste de la sierra de Pie de Palo, provincia de San Juan

    Directory of Open Access Journals (Sweden)

    Brígida Castro de Machuca

    2012-06-01

    Full Text Available A seismic velocity analysis from teleseismic receiver functions recorded in the southwestern fank of the Sierra de Pie de Palo (Western Sierras Pampeanas, Argentina, is compared with seismic properties directly calculated from lithological composition. The seismological results show an upper layer located in the first 13 km depth. A deeper contrast in seismic velocities is found at a depth of 28 km; the petrological results indicate a composition compatible with observed greenschist and amphibolite facies mafic rocks up to this depth. The receiver function measurements at 13 km and 28 km depths could be interpreted as two potential décollement levels that might have favoring a mechanism to thicken the whole crust, which produces a receiver function Moho signal located at 47 km depth. In addition, the lower crust between 28 km and 47 km exhibits high seismic P-wave velocities and Vp/Vs ratio (> 1.80 that are representative of a densification consistent with upper amphibolite to granulite/ecoglite facies lithologies. Based on these results, the combined petrological and seismological analyses suggest the continuation of the same mafic-crust outcropping lithologies into the lower levels of the 47-km thickened crust, which could be part of the Pie de Palo Complex ophiolite belt or the Precordillera basement.Un análisis de funciones del receptor registradas en el suroeste de la Sierra de Pie de Palo (Sierras Pampeanas Occidentales, Argentina, se compara con propiedades sísmicas directamente calculadas a partir de la composición litológica. Los resultados sismológicos indican una capa superior en los primeros 13 km. Otra zona de contraste entre las velocidades de ondas sísmicas, más profunda, se encuentra a unos 28 km; los resultados del análisis petrológico indican una composición compatible con rocas máficas en facies de esquistos verdes y anfibolitas hasta esa profundidad. Las observaciones de función del receptor a 13 y 28 km de

  8. Petrología y geoquímica de la unidad ígnea Quebrada Blanca, sierra de la Huerta, Provincia de San Juan Petrology and geochemistry of the Quebrada Blanca Igneous Unit, Sierra de La Huerta, province of San Juan.

    Directory of Open Access Journals (Sweden)

    Brígida Castro de Machuca

    2011-12-01

    Full Text Available La unidad ígnea Quebrada Blanca (Pérmico Superior-Triásico inferior, que intruye al basamento cristalino de la sierra de La Huerta, Sierras Pampeanas Occidentales, es el término más diferenciado de un grupo de rocas ígneas de edad y características similares. Está compuesta por un cuerpo hipabisal de pórfido riolítico, una brecha hidrotermal-intrusiva en la que se distinguen dos facies con marcadas diferencias texturales y composicionales, y diques felsíticos/riolíticos. Esta asociación rocosa define la raíz de una diatrema expuesta por la erosión. La génesis de la brecha estuvo asociada a la cristalización del pórfido riolítico, al brechamiento explosivo y a la exsolución de fluidos magmático-hidrotermales que fracturaron la caperuza solidificada del intrusivo y las rocas metamórficas circundantes, transportando los fragmentos hacia niveles más superficiales. El pórfido se terminó de emplazar con posterioridad, probablemente ocupando el conducto alimentador. Los datos geoquímicos indican para estas litologías contenidos altos en sílice, carácter subalcalino, calcoalcalino de alto K, y afinidad metaluminosa a débilmente peraluminosa. Los contenidos de elementos litófilos de gran radio iónico son altos mientras que los de Sr, P y Ti son bajos. Presentan enriquecimiento en LREE y empobrecimiento en HREE con la relación (La/YbN = 3,37 a 13,67. Las características geoquímicas son compatibles con las de rocas ígneas generadas en arcos volcánicos. Esta unidad es correlacionada tentativamente con la sección superior (dacítica-riolítica del Grupo Choiyoi, y se la asigna a las etapas finales de la evolución del arco magmático continental emplazado a lo largo del borde occidental de Gondwana a partir del Carbonífero superior.The Quebrada Blanca igneous unit (Upper Permian-Lower Triassic intruding the crystalline basement of the Sierra de La Huerta, Western Sierras Pampeanas, is the most differentiated member of a

  9. Sedimentología y evolución paleoambiental de la Formación Patquía (Pérmico en el extremo sur de la sierra de Maz y cerro Bola, provincia de La Rioja, Argentina Sedimentology and palaeoenvironmental evolution of the Patquía Formation (Permian, in the Sierra de Maz and cerro Bola, La Rioja Province, Argentina

    Directory of Open Access Journals (Sweden)

    A. T. Caselli

    2002-12-01

    Full Text Available En este trabajo se analizan las características sedimentológicas de la Formación Patquía en la Sierra de Maz y en el Cerro Bola (perfiles de cerro Guandacol, La Cortadera, cerro Noqués y cerro Bola, donde fueron reconocidas siete asociaciones de facies. La facies A está compuesta por aglomerados, brechas y conglomerados depositados en pequeños abanicos aluviales. Areniscas gruesas y conglomerados integran la facies B, la que fue probablemente depositada en planicies fluviales entrelazadas. La facies C incluye conglomerados y areniscas gruesas correspondientes a sistemas fluviales de baja sinuosidad. La facies D es la más extendida regionalmente y está compuesta por sabulitas, areniscas, pelitas y tobas, interpretadas como cursos fluviales de elevada sinuosidad. Un episodio de sedimentación eólica está registrado en la facies E, constituida por areniscas finas a medianas mostrando estratificación entrecruzada de gran escala. La facies F, areniscas y pelitas interestratificadas, fue depositada en lagos clásticos, someros y permanentes. La facies G incluye areniscas blanquecinas y pelitas rosadas, con intercalaciones de areniscas finas con estratificación entrecruzada de gran escala, sedimentadas en sistemas fluviales sinuosos con migración de dunas eólicas en las planicies. La composición modal de las areniscas permite identificar tres petrofacies. La cuarzoféldica representa el aporte del basamento de las Sierras Pampeanas. La cuarzofeldlítica incluye fragmentos de volcanitas ácidas y mesosilícicas relacionadas a la faja volcánica Permo-Triásica ubicada al oeste. La litomíxtica está dominada por líticos sedimentarios y paleovolcánicos provenientes de la Precordillera. Finalmente, el análisis estratigráfico de las facies arriba descriptas permitió la identificación de dos secuencias depositacionales.The sedimentological characteristics of the Patquía Formation in the Sierra de Maz and Cerro Bola areas were analyzed

  10. Acumulaciones de restos óseos en reparos rocosos de las sierras de Tandilia oriental, Argentina

    Directory of Open Access Journals (Sweden)

    Adrián Quintana, C.

    2004-04-01

    Full Text Available This article is an approach to the processes that influence in the formation of the paleontological record in the hills of Eastern Tandilia Range (Pampean Region of Argentina. The associations of fossil remains and the bony assemblage of the current surface, both of rocky shelters, are compared. The agents of incorporation of bones to the shelters, the causes of natural and human alterations, and the indicators of stability of the fossil record are described. The diversity and specific richness, the quantity of deposited bony remains, and the quality of the record is analyzed. Its concludes that: in the rocky repairs of Eastern Tandilia the causes that generate bony accumulations presently are not analogous to those of the last 11,000 years. The only exception is the deposit of bones coming from pellets of rapacious birds. This lack of agreement is due to: the strong human influences in the formation of the fossil record that caused deposits with more quantity of bones and diversity of species in the present-day record. This last one, it is only conditioned by natural factors.A modo de una primera aproximación a los procesos que condicionan la formación del registro paleontológico en las sierras de Tandilia Oriental (Región Pampeana de Argentina se comparan las asociaciones de restos fósiles de reparos rocosos con los conjuntos óseos de la superficie actual relevados en los mismos ámbitos. Se describen los agentes de ingreso de huesos a los reparos, las causas de alteraciones naturales y antrópicas, y los indicadores de estabilidad del registro fósil. Se analiza la diversidad y riqueza específica, la cantidad de restos óseos depositados, y la calidad del registro. Se concluye que en los reparos rocosos de Tandilia Oriental las causas que generan acumu-laciones óseas en el presente no son análogas a las de los últimos 11.000 años. La única excepción es el depósito de huesos provenientes de egagrópilas de aves rapaces. Esta

  11. Las estructuras de la Cuenca de Bermejo y Sierra de Valle Fértil a partir de los métodos deconvolución de Euler y señal analítica The structures of the Bermejo Basin and Sierra de la Huerta based on Euler deconvolution and analytic signal techniques

    Directory of Open Access Journals (Sweden)

    Federico Lince Klinger

    2008-06-01

    Full Text Available Se aplicaron técnicas de señal analítica y deconvolución de Euler a valores de anomalías de Bouguer de la cuenca de Bermejo y de la sierra de Valle Fértil, en el sector occidental de las Sierras Pampeanas. A partir de las soluciones encontradas por estas técnicas, se han interpretado la ubicación y profundidad de las fuentes causantes de anomalías, las que se vinculan con las estructuras geológicas que involucran al basamento. Con el objeto de verificar los resultados obtenidos y de minimizar las ambigüedades de los métodos potenciales, se preparó un modelo gravimétrico directo basado en un modelo estructural del área. A la respuesta gravimétrica de este modelo directo se le aplicó la técnica de señal analítica 2D, encontrándose soluciones que son consistentes con la profundidad y geometría de las fuentes previamente interpretadas, corroborando los resultados obtenidos.These geophysical techniques were applied to the Bouguer anomalies in the Bermejo Basin and Valle Fértil range. The location and depth to source of the anomalies were interpreted from the solutions obtained by these techniques. The found sources have been related with the geologic structures affecting the basement. In order to verify the results obtained and minimize the ambiguity of these potential methods, a forward gravimetric model was prepared, based on a geological and structural model of the area. The 2D analytic signal technique was applied to the gravimetric response of the model, and the solutions found are consistent with the depth and geometry of the above recognized sources, confirming the results obtained.

  12. Archaeological obsidian from La Sierra Gorda Mexico, by PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Juarez-Cossio, D.; Terreros, E.; Quiroz-Moreno, J.; Romero-Sanchez, S. [Instituto Nacional de Antropologia e Historia, Mexico. Seminario 8, Col. Centro. 06060 Mexico, DF (Mexico); Calligaro, T.F. [Centre de Recherche et de Restauration des Musees de France, UMR 171, Palais du Louvre-Porte des Lions, 14, Quai Francois Mitterrand, 75001 Paris (France); Tenorio, D. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico, DF (Mexico)], E-mail: dolores.tenorio@inin.gob.mx; Jimenez-Reyes, M. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico, DF (Mexico); Los Rios, M. de [Instituto Nacional de Antropologia e Historia, Mexico. Seminario 8, Col. Centro. 06060 Mexico, DF (Mexico)

    2009-04-15

    The chemical compositions of 42 obsidian pre-Hispanic artifacts from Tancama and Purisima, both archaeological sites of La Sierra Gorda Valleys, Mexico, were analyzed by PIXE technique. These obsidians came from four sources: Sierra de Pachuca Hidalgo, Paraiso Queretaro, Ucareo Michoacan and mainly from Zacualtipan/Metzquititlan Hidalgo. According to archaeological evidences, La Sierra Gorda valleys participated in commercial exchange with other regional sites, from Classic to Post-classic periods (A.D. 300-1500)

  13. El continuo trato con infieles: los renegados de la región pampeana centro-oriental durante el último tercio del siglo XVIII

    OpenAIRE

    Daniel Villar; Juan Francisco Jiménez

    2005-01-01

    Se considera el caso de los renegados, un conjunto poco numeroso de criollos, mestizos, negros y mulatos voluntariamente instalados entre los grupos indígenas de la región pampeana centro-oriental. Acogidos con flexibilidad por estos últimos, que los incorporaban a su vida y proyectos, los renegados representaron, en cambio, para la administración colonial la figura del traidor por antonomasia, totalmente volcados a auxiliar a los infieles para lo cual previamente debieron apartarse de dios y...

  14. Aspectos del manejo del agua y la fertilidad en Molisoles de la región semiárida pampeana

    OpenAIRE

    Quiroga, Alberto

    2004-01-01

    Nuestros trabajos parten de la hipótesis que los contenidos de la materia orgánica (MO), en Haplustoles y Hapludoles de la región semiárida y subhúmeda pampeana, resultan principalmente dependientes de factores relacionados con el régimen hídrico de los suelos (precipitaciones, capacidad de retención de agua y granulometría) y con el manejo de residuos (sistema de producción, secuencia de cultivos, sistema de labranza, fertilización). Este trabajo intentará mostrar la influencia de los...

  15. Post-Ebola Syndrome, Sierra Leone

    OpenAIRE

    Scott, Janet T.; Sesay, Foday R.; Massaquoi, Thomas A.; Idriss, Baimba R.; Sahr, Foday; Semple, Malcolm G.

    2016-01-01

    Thousands of persons have survived Ebola virus disease. Almost all survivors describe symptoms that persist or develop after hospital discharge. A cross-sectional survey of the symptoms of all survivors from the Ebola treatment unit (ETU) at 34th Regimental Military Hospital, Freetown, Sierra Leone (MH34), was conducted after discharge at their initial follow-up appointment within 3 weeks after their second negative PCR result. From its opening on December 1, 2014, through March 31, 2015, the...

  16. SIERRA Toolkit v. 2.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-14

    The SIERRA Toolkit is a collection of libraries to facilitate the development of parallel engineering analysis applications. These libraries supply basic core services that an engineering application may need such as a parallel distributed and dynamic mesh database (for unstructured meshes), mechanics algorithm support (parallel infrastructure only), interfaces to parallel solvers, parallel mesh and data I/O, and various utilities (timers, diagnostic tools, etc.)

  17. La dinámica del poblamiento humano del Sudeste de la Región Pampeana durante el Holoceno

    Directory of Open Access Journals (Sweden)

    Gustavo Barrientos

    2002-12-01

    Full Text Available El objetivo de este trabajo es discutir una serie de conceptos (v.g. población local, metapoblación, útiles para comprender la dinámica del poblamiento humano del Sudeste de la Región Pampeana durante el Holoceno. Dicha dinámica es concebida como el resultado de la alternancia de procesos de retracción y expansión poblacional (demográfica y geográfica, incluyendo ocasionalmente eventos significativos tales como la extinción local y la recolonización de espacios. Dos procesos, probablemente conducentes al reemplazo poblacional a nivel regional, son considerados en este trabajo: uno, ocurrido durante el Holoceno medio (ca. 6.000 a 4.000 años AP y otro, acontecido durante la fase final del Holoceno tardío (ca. 1.000 a 500 años AP. Ambos casos habrían involucrado el ingreso al área de poblaciones con distinto grado de vinculación con las poblaciones preexistentes, aunque probablemente obedeciendo a causas distintas. En base al análisis biométrico del esqueleto craneofacial de muestras diacrónicas del Sudeste de la Región Pampeana y del N.E. de Patagonia, se ponen a prueba estas dos hipótesis.A central goal of this paper is to introduce and discuss useful concepts (e.g., local populations and metapopulations for better understanding the dynamics of the human peopling of the Southeastern Pampean Region during the Holocene. Such a dynamic is conceived as resulting from alternating processes of population retraction and expansion (both demographic and geographic, occasionally including some significant events like local extinction and re-colonization. Two main processes, probably involving population replacement at the regional level, are considered. The first process occurred in the Mid Holocene (ca. 6000-4000 BP, and the second at the end of the Late Holocene (ca. 1000-500 BP. Both cases may involve the entry into the area of populations with a distinct degree of relatedness with respect to the pre-existent local populations

  18. Implementing an Ebola Vaccine Study - Sierra Leone.

    Science.gov (United States)

    Widdowson, Marc-Alain; Schrag, Stephanie J; Carter, Rosalind J; Carr, Wendy; Legardy-Williams, Jennifer; Gibson, Laura; Lisk, Durodami R; Jalloh, Mohamed I; Bash-Taqi, Donald A; Kargbo, Samuel A Sheku; Idriss, Ayesha; Deen, Gibrilla F; Russell, James B W; McDonald, Wendi; Albert, Alison P; Basket, Michelle; Callis, Amy; Carter, Victoria M; Ogunsanya, Kelli R Clifton; Gee, Julianne; Pinner, Robert; Mahon, Barbara E; Goldstein, Susan T; Seward, Jane F; Samai, Mohamed; Schuchat, Anne

    2016-01-01

    In October 2014, the College of Medicine and Allied Health Sciences of the University of Sierra Leone, the Sierra Leone Ministry of Health and Sanitation, and CDC joined the global effort to accelerate assessment and availability of candidate Ebola vaccines and began planning for the Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE). STRIVE was an individually randomized controlled phase II/III trial to evaluate efficacy, immunogenicity, and safety of the recombinant vesicular stomatitis virus Ebola vaccine (rVSV-ZEBOV). The study population was health care and frontline workers in select chiefdoms of the five most affected districts in Sierra Leone. Participants were randomized to receive a single intramuscular dose of rVSV-ZEBOV at enrollment or to receive a single intramuscular dose 18-24 weeks after enrollment. All participants were followed up monthly until 6 months after vaccination. Two substudies separately assessed detailed reactogenicity over 1 month and immunogenicity over 12 months. During the 5 months before the trial, STRIVE and partners built a research platform in Sierra Leone comprising participant follow-up sites, cold chain, reliable power supply, and vaccination clinics and hired and trained at least 350 national staff. Wide-ranging community outreach, informational sessions, and messaging were conducted before and during the trial to ensure full communication to the population of the study area regarding procedures and current knowledge about the trial vaccine. During April 9-August 15, 2015, STRIVE enrolled 8,673 participants, of whom 453 and 539 were also enrolled in the safety and immunogenicity substudies, respectively. As of April 28, 2016, no Ebola cases and no vaccine-related serious adverse events, which by regulatory definition include death, life-threatening illness, hospitalization or prolongation of hospitalization, or permanent disability, were reported in the study population. Although STRIVE will not produce an

  19. Evaluación de la sequía 2008-2009 en el oeste de la Región Pampeana (Argentina)

    OpenAIRE

    Guillermo T. D\\u2019Ambrosio; Vanesa Y. Bohn; M. Cintia. Piccolo

    2013-01-01

    Se analiza la variabilidad de la precipitación y los efectos de la sequía en la extensión areal del Dique Paso de las Piedras y en la actividad agrícola del Oeste de la región pampeana (Argentina) durante los años 2008-2009. La metodología incluye la aplicación del Índice Estandarizado de Precipitación, el procesamiento digital de imágenes satelitales y el análisis de los rendimientos productivos de cuatro cultivos de la región. El Índice Estandarizado de Precipitación ha indicado sequía mete...

  20. La Formación Balbuena, integrante del arco magmático pampeano en la sierra de Ambargasta, provincia de Santiago del Estero

    Directory of Open Access Journals (Sweden)

    M Koukharsky

    2003-12-01

    Full Text Available En un sector de las Sierras Pampeanas Orientales (29°25´ - 29°35´S y 63°43´ - 64°00´O, se estudió un conjunto de diques de acimutes entre 90 y 120° y espesores inferiores a los 10 m, que se incluyen en la Formación Balbuena. Sus composiciones abarcan dacitas, andesitas y andesitas basálticas y son interpretados como los representantes intermedios y básicos de una serie calcoalcalina cuyo extremo ácido se encontraría en los ya conocidos Pórfiros riodacíticos de Oncán aflorantes en el borde occidental del área. Son finamente porfíricos y se caracterizan por una intensa alteración de los componentes máficos y pastas, resultante de una importante actividad deutérica. Intruyen a los granitoides de las Formaciones Ojo de Agua y Ambargasta, ambos del Cámbrico medio a superior según determinaciones isotópicas. Sobre la base de edades K/Ar preexistentes, a las que se añaden dos nuevos valores, sumadas a observaciones de campo, se asignan los diques a un mismo ciclo magmático plutónico-volcánico, confirmando la vinculación ya aceptada en investigaciones anteriores para las volcanitas ácidas. Su signatura geoquímica apoya la existencia de un arco previamente postulado por otros autores y corresponden a una ubicación de arco a retroarco. Se habría desarrollado sobre corteza continental. La Formación Balbuena pertenecería al último de los eventos magmáticos importantes del ciclo Pampeano propuestos para la región.

  1. Geomagnetic Polarity Epochs: Sierra Nevada II.

    Science.gov (United States)

    Cox, A; Doell, R R; Dalrymple, G B

    1963-10-18

    Ten new determinations on volcanic extrusions in the Sierra Nevada with potassium-argon ages of 3.1 million years or less indicate that the remanent magnetizations fall into two groups, a normal group in which the remanent magnetization is directed downward and to the north, and a reversed group magnetized up and to the south. Thermomagnetic experiments and mineralogic studies fail to provide an explanation of the opposing polarities in terms of mineralogic control, but rather suggest that the remanent magnetization reflects reversals of the main dipole field of the earth. All available radiometric ages are consistent with this field-reversal hypothesis and indicate that the present normal polarity epoch (N1) as well as the previous reversed epoch (R1) are 0.9 to 1.0 million years long, whereas the previous normal epoch (N2) was at least 25 percent longer. PMID:17799480

  2. Adhesive joint and composites modeling in SIERRA.

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Yuki; Brown, Arthur A.; Hammerand, Daniel Carl; Adolf, Douglas Brian; Chambers, Robert S.; Foulk, James W., III (.,; )

    2005-11-01

    Polymers and fiber-reinforced polymer matrix composites play an important role in many Defense Program applications. Recently an advanced nonlinear viscoelastic model for polymers has been developed and incorporated into ADAGIO, Sandia's SIERRA-based quasi-static analysis code. Standard linear elastic shell and continuum models for fiber-reinforced polymer-matrix composites have also been added to ADAGIO. This report details the use of these models for advanced adhesive joint and composites simulations carried out as part of an Advanced Simulation and Computing Advanced Deployment (ASC AD) project. More specifically, the thermo-mechanical response of an adhesive joint when loaded during repeated thermal cycling is simulated, the response of some composite rings under internal pressurization is calculated, and the performance of a composite container subjected to internal pressurization, thermal loading, and distributed mechanical loading is determined. Finally, general comparisons between the continuum and shell element approaches for modeling composites using ADAGIO are given.

  3. Sierra Nevada Mountain Range as seen from STS-58

    Science.gov (United States)

    1994-01-01

    The Sierra Nevada Mountain Range can be seen in this north-looking high oblique view taken in October, 1993, by the STS-58 crew. Visible in the view to the west of the Sierra Nevada are the San Joaquin and Sacramento Valleys of central California. The San Francisco/Oakland Bay Area can be seen to the west of the valley at the extreme left of the photograph. To the east or right of the Sierra Nevada, the basin and Range Region of central and northern Nevada is visible. Mono Lake, Lake Tahoe and Pyramid lake are also visible in this scene. The long northwest/southeast trending Walker Lane Shear Zone, which lies just to the east (right) of the Sierra Nevada is also visible. Near the top of the view (near the horizon), the snow covered volcanic peak Mount Shasta can be seen.

  4. Echocardiographic analysis of a malfunctioning Davila-Sierra mitral valve

    OpenAIRE

    Tri, Terry B.; Gregoratos, Gabriel

    1981-01-01

    Although the Davila-Sierra mitral valve prosthesis was removed from the market nearly a decade ago, a number of patients still have this valve in place. We recently studied the echocardiographic features of a malfunctioning Davila-Sierra mitral valve prosthesis. Abnormalities that suggested improper functioning of the prosthesis included a markedly delayed poppet opening and an early diastolic hump believed to represent motion of the mitral annulus. Previously described echocardiographic indi...

  5. Functional Requirements for SIERRA Version 1.0 Beta; TOPICAL

    International Nuclear Information System (INIS)

    The objective of the SIERRA framework is to provide a common software infrastructure for massively parallel computational mechanics applications. The SIERRA framework consolidates the mechanics-independent computational services required by a diverse set of mechanics applications into a shared framework. Consolidation of these computational services eliminates their redundant development and maintenance efforts and streamlines the coupling of independently developed computational mechanics capabilities into integrated multi-mechanics applications

  6. International Marketing Strategy of Transformations LTD in Sierra Leone

    OpenAIRE

    Alam, Mohammed Touqeer

    2011-01-01

    The central idea of the report is to formulate an international marketing strategy for Transformations Ltd, a learning and development company based in UK for its entry in Sierra Leone market. The company wants to provide accredited British Leadership and Management qualification in Sierra Leone. The report uses theoretical framework for marketing analyses including internationalization models, entry mode, market segmentation, targeting, positioning and generic strategy. The report adopte...

  7. Sierra Structural Dynamics User's Notes

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Garth M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-19

    Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of weapons systems. This document provides a users guide to the input for Sierra/SD. Details of input specifications for the different solution types, output options, element types and parameters are included. The appendices contain detailed examples, and instructions for running the software on parallel platforms.

  8. La Formación Balbuena, integrante del arco magmático pampeano en la sierra de Ambargasta, provincia de Santiago del Estero The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero

    Directory of Open Access Journals (Sweden)

    M Koukharsky

    2003-12-01

    Full Text Available En un sector de las Sierras Pampeanas Orientales (29°25´ - 29°35´S y 63°43´ - 64°00´O, se estudió un conjunto de diques de acimutes entre 90 y 120° y espesores inferiores a los 10 m, que se incluyen en la Formación Balbuena. Sus composiciones abarcan dacitas, andesitas y andesitas basálticas y son interpretados como los representantes intermedios y básicos de una serie calcoalcalina cuyo extremo ácido se encontraría en los ya conocidos Pórfiros riodacíticos de Oncán aflorantes en el borde occidental del área. Son finamente porfíricos y se caracterizan por una intensa alteración de los componentes máficos y pastas, resultante de una importante actividad deutérica. Intruyen a los granitoides de las Formaciones Ojo de Agua y Ambargasta, ambos del Cámbrico medio a superior según determinaciones isotópicas. Sobre la base de edades K/Ar preexistentes, a las que se añaden dos nuevos valores, sumadas a observaciones de campo, se asignan los diques a un mismo ciclo magmático plutónico-volcánico, confirmando la vinculación ya aceptada en investigaciones anteriores para las volcanitas ácidas. Su signatura geoquímica apoya la existencia de un arco previamente postulado por otros autores y corresponden a una ubicación de arco a retroarco. Se habría desarrollado sobre corteza continental. La Formación Balbuena pertenecería al último de los eventos magmáticos importantes del ciclo Pampeano propuestos para la región.A set of dikes in the Eastern Sierras Pampeanas (29°25´ - 29°35´S y 63°43´ - 64°00´W trending from 90° to 120° azimuths and with thickness less than 10 m wide are assigned to the Balbuena Formation. These dikes are basaltic, andesitic to dacitic in composition representing basic to intermediate members of the calc-alkaline magmas that gave rise to the rhyodacitic Oncán Porphyries. The fine porphyritic rocks of the Balbuena Formation have an intense alteration of the mafic minerals and groundmass

  9. Contaminant studies in the Sierra Nevadas

    Science.gov (United States)

    Sparling, D.W.; Fellers, G.

    2002-01-01

    full text: Several species of anuran amphibians (frogs and toads) are experiencing severe population declines in even seemingly pristine areas of the Sierra Mountains of California. Among the most severely depressed species are the redlegged frog, the foothill and mountain yellow-legged frogs, the Yosemite toad, and the Cascades frog. Several factors, such as habitat fragmentation, introduced predators (especially fish), and disease, have been linked to these declines. But recent evidence from a USGS-led study shows that contaminants are a primary factor. During the past three years, researchers from the USGS Patuxent Wildlife Research Center, the Western Ecology Research Center, the USDA Beltsville Agriculture Research Center, and the Texas A&M University have teamed up to conduct an extensive study on airborne pesticides and their effects on amphibian populations in the Sierra Nevada Mountains. Previous work on environmental chemistry demonstrated that pesticides from the intensely agricultural Central Valley of California are being blown into the more pristine Sierra Nevada Mountains, especially around Sequoia and Yosemite National Parks. Several pesticides, including diazinon, chlorpyrifos, malathion and endosulfan, can be measured in snow, rainfall, and pond waters in these national parks. With the exception of endosulfan, these pesticides affect and even kill both invertebrates and vertebrate species by inhibiting cholinesterase, an enzyme essential to proper nervous system functioning. In the summer of 2001, we published a paper showing that these same pesticides are now found in adults and the tadpoles of Pacific treefrogs. The results of this landmark study showed that more than 50 percent of the tadpoles and adults sampled in Yosemite and Sequoia National Parks had detectable levels of diazinon or chlorpyrifos and that 86 percent of the Pacific treefrogs sampled in the Lake Tahoe region had detectable levels of endosulfan. In contrast, frogs that were

  10. Post-Ebola Syndrome, Sierra Leone.

    Science.gov (United States)

    Scott, Janet T; Sesay, Foday R; Massaquoi, Thomas A; Idriss, Baimba R; Sahr, Foday; Semple, Malcolm G

    2016-04-01

    Thousands of persons have survived Ebola virus disease. Almost all survivors describe symptoms that persist or develop after hospital discharge. A cross-sectional survey of the symptoms of all survivors from the Ebola treatment unit (ETU) at 34th Regimental Military Hospital, Freetown, Sierra Leone (MH34), was conducted after discharge at their initial follow-up appointment within 3 weeks after their second negative PCR result. From its opening on December 1, 2014, through March 31, 2015, the MH34 ETU treated 84 persons (8-70 years of age) with PCR-confirmed Ebola virus disease, of whom 44 survived. Survivors reported musculoskeletal pain (70%), headache (48%), and ocular problems (14%). Those who reported headache had had lower admission cycle threshold Ebola PCR than did those who did not (psurvivor cohort from 1 ETU enables analysis of the proportion of symptoms of post-Ebola syndrome. The Ebola epidemic is waning, but the effects of the disease will remain. PMID:26983037

  11. La estructura del Grupo Sierras Bayas en el sector norte de las sierras homónimas, noroeste de las Sierras Septentrionales de Buenos Aires

    Directory of Open Access Journals (Sweden)

    A.C. Massabie

    2005-03-01

    Full Text Available El Grupo Sierras Bayas, de edad precámbrica tardía, se halla integrado por las formaciones sedimentarias Villa Mónica, Cerro Largo y Loma Negra, y forman parte de la porción noroccidental de las Sierras Septentrionales de Buenos Aires. Los afloramientos principales, relativamente aislados en serranías bajas, se ubican en los alrededores de Olavarría, particularmente en las Sierras Bayas, y con menor extensión en cercanías a la localidad de Barker. La morfoestructura de conjunto de estas sedimentitas en el sector norte de las Sierras Bayas corresponde a una cubeta asimétrica levemente basculada hacia el sudsudoeste. En el Grupo Sierras Bayas, se han identificado y relevado sistemáticamente dos sistemas de plegamiento suave F1 (NE y F2 (NO que se interfieren y generan diseños de tipo 1 en domos y cubetas. Los plegamientos reconocidos, F1 y F2, de planos axiales subverticales y ejes B subhorizontales se interfieren con ángulos que varían entre 70º y 90º. Desarrollan tres órdenes de plegamiento que controlan en las escalas adoptadas para el mapeo, la posición de los afloramientos y exposiciones artificiales de las formaciones integrantes del Grupo Sierras Bayas. El fallamiento local relevado ejerce un control muy limitado sobre la disposición de las sedimentitas precámbricas plegadas, y las observaciones de campo avalan su actividad inicial con posterioridad al episodio tectónico que desarrolló los sistemas de plegamiento del Grupo Sierras Bayas. La deformación dúctil de la cubierta sedimentaria, como ha sido observado localmente, se considera que ha estado asociada con una reactivación tectónica del basamento, Complejo Buenos Aires, favorecida por las anisotropías penetrativas principales preexistentes en el macizo rocoso de granititas milonitizadas. La similitud en el diseño de los plegamientos F1 y F2, la morfoestructura general en cubeta y la falta de una secuencia definida en las relaciones de interferencia permitir

  12. Environmental values and risk: A review of Sierra Club policies

    International Nuclear Information System (INIS)

    Sierra Club values are driven by an overriding environmental ethic. Sierra Club environmental values may be characterized by the concept of 'usufruct' a term favored by United States Founding Father Thomas Jefferson. Usufruct conveys the idea that the environment is ours to use, but not to destroy. Each generation has the obligation to pass on to future generations a world at least as environmentally rich as the one it inherited. It is appropriate to accept risk today in order to preserve the environment for generations yet to come. As viewed through the lens of its formal policies, the Sierra Club is an organization that embraces technology, but insists that technology be evaluated comprehensively, taking full account of both environmental and social externalities. The Club is 'risk averse' with respect to early introduction of technologies seen as likely to have significant negative environmental or social impact. The Club places heavy emphasis on process, which must involve the public meaningfully

  13. SIERRA - A 3-D device simulator for reliability modeling

    Science.gov (United States)

    Chern, Jue-Hsien; Arledge, Lawrence A., Jr.; Yang, Ping; Maeda, John T.

    1989-05-01

    SIERRA is a three-dimensional general-purpose semiconductor-device simulation program which serves as a foundation for investigating integrated-circuit (IC) device and reliability issues. This program solves the Poisson and continuity equations in silicon under dc, transient, and small-signal conditions. Executing on a vector/parallel minisupercomputer, SIERRA utilizes a matrix solver which uses an incomplete LU (ILU) preconditioned conjugate gradient square (CGS, BCG) method. The ILU-CGS method provides a good compromise between memory size and convergence rate. The authors have observed a 5x to 7x speedup over standard direct methods in simulations of transient problems containing highly coupled Poisson and continuity equations such as those found in reliability-oriented simulations. The application of SIERRA to parasitic CMOS latchup and dynamic random-access memory single-event-upset studies is described.

  14. Ebola Surveillance - Guinea, Liberia, and Sierra Leone.

    Science.gov (United States)

    McNamara, Lucy A; Schafer, Ilana J; Nolen, Leisha D; Gorina, Yelena; Redd, John T; Lo, Terrence; Ervin, Elizabeth; Henao, Olga; Dahl, Benjamin A; Morgan, Oliver; Hersey, Sara; Knust, Barbara

    2016-01-01

    Developing a surveillance system during a public health emergency is always challenging but is especially so in countries with limited public health infrastructure. Surveillance for Ebola virus disease (Ebola) in the West African countries heavily affected by Ebola (Guinea, Liberia, and Sierra Leone) faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information technology resources, limited telephone and Internet service, and overwhelming numbers of infected persons. Through the work of CDC and numerous partners, including the countries' ministries of health, the World Health Organization, and other government and nongovernment organizations, functional Ebola surveillance was established and maintained in these countries. CDC staff were heavily involved in implementing case-based surveillance systems, sustaining case surveillance and contact tracing, and interpreting surveillance data. In addition to helping the ministries of health and other partners understand and manage the epidemic, CDC's activities strengthened epidemiologic and data management capacity to improve routine surveillance in the countries affected, even after the Ebola epidemic ended, and enhanced local capacity to respond quickly to future public health emergencies. However, the many obstacles overcome during development of these Ebola surveillance systems highlight the need to have strong public health, surveillance, and information technology infrastructure in place before a public health emergency occurs. Intense, long-term focus on strengthening public health surveillance systems in developing countries, as described in the Global Health Security Agenda, is needed.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html). PMID:27389614

  15. SierraDNA – Demonstrating the Usefulness of Direct ILS Database Access

    OpenAIRE

    James Padgett; Jonathan Hooper

    2015-01-01

    Innovative Interface’s Sierra(™) Integrated Library System (ILS) brings with it a Database Navigator Application (SierraDNA) - in layman's terms SierraDNA gives Sierra sites read access to their ILS database. Unlike the closed use cases produced by vendor supplied APIs, which restrict Libraries to limited development opportunities, SierraDNA enables sites to publish their own APIs and scripts based upon custom SQL code to meet their own needs and those of their users and processes. In thi...

  16. Evaluación de la sequía 2008-2009 en el oeste de la Región Pampeana (Argentina

    Directory of Open Access Journals (Sweden)

    Guillermo T. D\\u2019Ambrosio

    2013-01-01

    Full Text Available Se analiza la variabilidad de la precipitación y los efectos de la sequía en la extensión areal del Dique Paso de las Piedras y en la actividad agrícola del Oeste de la región pampeana (Argentina durante los años 2008-2009. La metodología incluye la aplicación del Índice Estandarizado de Precipitación, el procesamiento digital de imágenes satelitales y el análisis de los rendimientos productivos de cuatro cultivos de la región. El Índice Estandarizado de Precipitación ha indicado sequía meteorológica en los años 2008 y 2009. En 2009 el rendimiento de los cultivos ha disminuido entre el 25 y 65 % con respecto a años anteriores. La extensión areal del dique ha disminuido un 52 % en 2009 en relación a períodos húmedos.

  17. Sobre la homogeinización de la presión fiscal en la agricultura pampeana tras la devaluación.

    Directory of Open Access Journals (Sweden)

    Diego Ariel Fernández

    2014-04-01

    Full Text Available La década del ’90 marcó una fuerte aceleración del proceso de concentración económica de la producción agrícola pampeana, evolución que continuaría tras la devaluación de 2002. En la determinación del mismo convergen distintos factores: las economías de escala, el manejo cambiario, la evolución tecnológica (entre otros. En este trabajo se estudia uno de estos condicionantes: la política impositiva del Estado Nacional. Se analizan los tributos que gravan al agro y sus alícuotas, diferenciando según la escala y perfil tecnológico del productor, calculando un indicador de la presión fiscal (peso de los tributos sobre el ingreso bruto de la explotación. Se concluye que en el nuevo siglo se produjo una nivelación importante en cuanto a los montos impositivos requeridos por el Estado a los distintos tipos de agentes, lo que minimizó la posibilidad que tiene éste a partir de aquella herramienta de modelar una trama social más desconcentrada.

  18. Sierra/solid mechanics 4.22 user's guide.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Jesse David

    2011-10-01

    Sierra/SolidMechanics (Sierra/SM) is a Lagrangian, three-dimensional code for the analysis of solids and structures. It provides capabilities for explicit dynamic and implicit quasistatic and dynamic analyses. The explicit dynamics capabilities allow for the efficient and robust solution of models subjected to large, suddenly applied loads. For implicit problems, Sierra/SM uses a multi-level iterative solver, which enables it to effectively solve problems with large deformations, nonlinear material behavior, and contact. Sierra/SM has a versatile library of continuum and structural elements, and an extensive library of material models. The code is written for parallel computing environments, and it allows for scalable solutions of very large problems for both implicit and explicit analyses. It is built on the SIERRA Framework, which allows for coupling with other SIERRA mechanics codes. This document describes the functionality and input structure for Sierra/SM.

  19. Reemergence of chikungunya virus in Bo, Sierra Leone.

    Science.gov (United States)

    Ansumana, Rashid; Jacobsen, Kathryn H; Leski, Tomasz A; Covington, Andrea L; Bangura, Umaru; Hodges, Mary H; Lin, Baochuan; Bockarie, Alfred S; Lamin, Joseph M; Bockarie, Moses J; Stenger, David A

    2013-07-01

    We diagnosed 400 possible IgM-positive cases of chikungunya virus in Bo, Sierra Leone, during July 2012-January 2013 by using lateral flow immunoassays. Cases detected likely represent only a small fraction of total cases. Further laboratory testing is required to confirm this outbreak and characterize the virus. PMID:23764023

  20. Relative Contributions of Phosphorus in High Elevation Sierra Nevada Lakes

    Science.gov (United States)

    Jensen, L. K.; McIntyre, B. M.; Lyons, R. A.

    2015-12-01

    High elevation lakes of the Sierra Nevada mountain range show signs of eutrophication due to increased phosphorus loading. Phosphorus is a major contributing factor to freshwater lake eutrophication when in excess. Three previously researched sources of phosphorus to high-elevation montane lakes include atmospheric deposition, internal loading from sediments, and excretions from non-native stocked fish. The goal of this research was to isolate the estimated phosphorus contributions from residential shoreline developments and stocked non-native fish. A steady-state phosphorus loading rate model was created to quantify relative phosphorus loading into two lakes in the Eastern Sierra Nevada: Convict and Silver Lake. A conglomerate control lake was created from Eastern Brook Lake in the Eastern Sierra Nevada, Pear Lake in the Southern Sierra Nevada, and Snowflake Lake in Canada. Both Convict and Silver Lakes contain stocked non-native trout species and Silver Lake also has ~25 vacation homes on its eastern shore. Seasonal steady-state total phosphorus concentrations were determined using EPA Method 365.2. Loading rate constants were calculated using loading rates from literature and corresponding concentrations. It was determined that as much as 42% of phosphorous to Silver Lake came from shoreline housing developments, and 24% came from stocked fish depending on the season. Previous studies showed much lower contributions from non-native fish.

  1. Power in Practice: Trade Union Education in Sierra Leone

    Science.gov (United States)

    Stirling, John

    2013-01-01

    This article presents an analysis of the development of a trade union education program in Sierra Leone in the geo-historical context of British colonialism. It places the argument in relation to the contradictory trends of trade unionism more generally and alongside their antagonistic cooperation with capitalism. It discusses the limits and…

  2. An accidental sect: how war made belief in Sierra Leone

    NARCIS (Netherlands)

    Richards, P.

    2006-01-01

    Idealists consider beliefs cause wars. Realists consider wars cause beliefs. The war in Sierra Leone offers some scope to test between these two views. The main rebel faction, the Revolutionary United Front (RUF) was, sociologically speaking, an accidental sect. It lost its original ideologues at an

  3. Correlation of the Klamath Mountains and Sierra Nevada

    Science.gov (United States)

    Irwin, William P.

    2003-01-01

    This report graphically portrays the broadly parallel tectonic development of the Klamath Mountains and Sierra Nevada from early Paleozoic to Early Cretaceous time. It is dedicated to J.S. Diller of the U.S. Geological Survey who, during his pioneer field studies a century ago, recognized significant similarities between these two important provinces. The report is based mainly on the numerous published reports of the field and laboratory studies by various geologists and students during the last century, and to a lesser extent on my own field work which has been substantial in the Klamath Mountains but minimal in the Sierra Nevada. For brevity, required by the format of this report, little of the extensive literature pertaining to these two provinces is referenced. This report is preliminary in nature and was prepared as an aid to further study of the tectonic relations between the Klamath Mountains and Sierra Nevada. This report consists of two sheets: Sheet 1, Map showing accreted terranes and plutons of the Klamath Mountains and Sierra Nevada, and Sheet 2, Successive accretionary episodes of the Klamath mountains and northern part of Sierra Nevada, showing related plutonic, volcanic, and metamorphic events. The map on Sheet 1 was compiled and modified from two Open-File maps (Irwin and Wooden, 1999 and 2001) which had been compiled and modified mainly from Jennings (1977), Harwood (1992), Irwin (1994), Jayko (1988), Graymer and Jones (1994), Edelman and Sharp (1989), Schweickert and others (1999), Saucedo and Wagner(1992), Saleeby and Sharp (1980), Wagner and others (1981), and various other sources. For detailed lists of the sources for the isotopic age data used in Sheets 1 and 2, see Irwin and Wooden (1999 and 2001). On Sheet 2, the accretionary episodes are shown sequentially from left to right in two tiers of figures. Episodes for the Klamath Mountains are in the upper tier; correlative episodes of the Sierra Nevada are directly below in the lower tier

  4. Health complications of female genital mutilation in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Bjälkander O

    2012-07-01

    Full Text Available Owolabi Bjälkander,1 Laurel Bangura,2 Bailah Leigh,3 Vanja Berggren,1 Staffan Bergström,1 Lars Almroth11Division of Global Health, Department of Public Health, Karolinska Institutet, Stockholm, Sweden; 2Inter Africa Committee, Sierra Leone; 3Department of Community Health, College of Medicine and Allied Health Sciences, University of Sierra Leone, Sierra LeoneAbstract: Sierra Leone has one of the highest rates of female genital mutilation (FGM in the world, and yet little is known about the health consequences of the practice.Purpose: To explore whether and what kind of FGM-related health complications girls and women in Sierra Leone experience, and to elucidate their health care-seeking behaviors.Patients and methods: A feasibility study was conducted to test and refine questionnaires and methods used for this study. Thereafter, a cross-section of girls and women (n = 258 attending antenatal care and Well Women Clinics in Bo Town, Bo District, in the southern region and in Makeni Town, Bombali District, in the northern region of Sierra Leone were randomly selected. Participants answered interview-administrated pretested structured questionnaires with open-ended-questions, administrated by trained female personnel.Results: All respondents had undergone FGM, most between 10 and 14 years of age. Complications were reported by 218 respondents (84.5%, the most common ones being excessive bleeding, delay in or incomplete healing, and tenderness. Fever was significantly more often reported by girls who had undergone FGM before 10 years of age compared with those who had undergone the procedure later. Out of those who reported complications, 187 (85.8% sought treatment, with 89 of them visiting a traditional healer, 75 a Sowei (traditional circumciser, and 16 a health professional.Conclusion: The high prevalence rate of FGM and the proportion of medical complications show that FGM is a matter for public health concern in Sierra Leone. Girls who

  5. Lassa Fever in Post-Conflict Sierra Leone

    Science.gov (United States)

    Hartnett, Jessica N.; Levy, Danielle C.; Yenni, Rachael E.; Moses, Lina M.; Fullah, Mohammed; Momoh, Mambo; Fonnie, Mbalu; Fonnie, Richard; Kanneh, Lansana; Koroma, Veronica J.; Kargbo, Kandeh; Ottomassathien, Darin; Muncy, Ivana J.; Jones, Abigail B.; Illick, Megan M.; Kulakosky, Peter C.; Haislip, Allyson M.; Bishop, Christopher M.; Elliot, Deborah H.; Brown, Bethany L.; Zhu, Hu; Hastie, Kathryn M.; Andersen, Kristian G.; Gire, Stephen K.; Tabrizi, Shervin; Tariyal, Ridhi; Stremlau, Mathew; Matschiner, Alex; Sampey, Darryl B.; Spence, Jennifer S.; Cross, Robert W.; Geisbert, Joan B.; Folarin, Onikepe A.; Happi, Christian T.; Pitts, Kelly R.; Geske, F. Jon; Geisbert, Thomas W.; Saphire, Erica Ollmann; Robinson, James E.; Wilson, Russell B.; Sabeti, Pardis C.; Henderson, Lee A.; Khan, S. Humarr; Bausch, Daniel G.; Branco, Luis M.; Garry, Robert F.

    2014-01-01

    Background Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Methodology/Principal Findings Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs) in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects. Conclusions/Significance Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to

  6. Lassa fever in post-conflict sierra leone.

    Directory of Open Access Journals (Sweden)

    Jeffrey G Shaffer

    2014-03-01

    Full Text Available Lassa fever (LF, an often-fatal hemorrhagic disease caused by Lassa virus (LASV, is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002 ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH in an area with the world's highest incidence of the disease.Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects.Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to develop more effective and/or supplemental treatments for

  7. Experiencias de la asociación ajo Allium Sativum y verdura de hoja en la región semiárida pampeana

    OpenAIRE

    Lara, Gabriel; Urbano, Valeria; Anzorena, Carlos

    2015-01-01

    La región semiárida pampeana resulta un ambiente propicio para el cultivo de ajo, sin embargo los productores encuentran algunas desventajas que hace que sean reticentes a su plantación, se menciona el largo periodo de utilización del terreno; obtención de una única cosecha al final del ciclo; entre otros. Se experimentó el policultivo de Ajo Allium Sativum + Acelga Beta vulgaris var cicla y luego Ajo + Espinaca Spinacia oleracea, tanto en riego por surco como en riego por goteo. La experienc...

  8. Metodología de análisis de hipoplasias del esmalte dental aplicada al estudio de poblaciones prehispánicas del sudeste de la Región Pampeana

    OpenAIRE

    Barrientos, Gustavo

    1999-01-01

    El objetivo de este trabajo es presentar la metodología de análisis de hipoplasias del esmalte dental aplicada al estudio de una muestra de esqueletos humanos provenientes de diversos sitios arqueológicos del Sudeste de la Región Pampeana, asignables a distintos momentos del Holoceno. Para cada diente, se realizó una evaluación del grado de sensibilidad para el registro de hipoplasias y del grado de representatividad a nivel muestral. Debido a que los dientes con mayor frecuencia relativa de ...

  9. Virajes en las políticas públicas de tierras. Continuidades y discontinuidades a partir de la segunda mitad del siglo XX, región pampeana. Argentina

    OpenAIRE

    Marina Bustamante

    2011-01-01

    El acceso a la tierra -tanto a la propiedad como al usufructo- es de capital importancia en el desarrollo socio-económico de la Región Pampeana argentina y, por tanto, ha sido objeto de diversas políticas públicas. Sin embargo, su formulación e implementación ha sido dinámica y cambiante, en función del contexto mundial y nacional y en función de voluntades políticas que responden y promueven un determinado estilo de desarrollo. A partir de dicha consideración, se identifican - desde mediados...

  10. El continuo trato con infieles: los renegados de la región pampeana centro-oriental durante el último tercio del siglo XVIII

    Directory of Open Access Journals (Sweden)

    Daniel Villar

    2005-12-01

    Full Text Available Se considera el caso de los renegados, un conjunto poco numeroso de criollos, mestizos, negros y mulatos voluntariamente instalados entre los grupos indígenas de la región pampeana centro-oriental. Acogidos con flexibilidad por estos últimos, que los incorporaban a su vida y proyectos, los renegados representaron, en cambio, para la administración colonial la figura del traidor por antonomasia, totalmente volcados a auxiliar a los infieles para lo cual previamente debieron apartarse de dios y abandonar al rey, convirtiéndose en seres irredimibles y peligrosos. Una serie de diacríticos que revelaban su singular condición transcultural contribuyeron a aumentar el grado de exposición al riesgoimplicado por su actividad como espías y baqueanos, y al tiempo que facilitaron su identificación y castigo, les confirieron una visibilidad documental que permite reflexionar sobre el contexto de mixegenación cultural 1 en el que sus presencias cobran sentido.The subject matter is the renegadoes, a small group of criollos, mestizos, black men and mulattoes, voluntarily settled among the indigenous groups of the central-west region of the pampas. Received with flexibility by the latter, who incorporated them into their lives and projects, the renegadoes were seen as absolute traitors by the colonial administration since, after abandoning the Christian god and king, they dedicated themselves to helping the unfaithful becoming irredeemable and dangerous beings. A series of diacritics, that revealed their unique transcultural condition, contributed to increase the risk exposure implied by their activities as spies and scouts (baqueanos, facilitating their identification and punishment and also granting them a documentary visibility that allows us to think about the cultural miscegenation context in which their presence became significant.

  11. Estructuras primarias, secundarias y evolución estructural de las corneanas de La Clemira, sierra de Ambargasta, Santiago del Estero

    Directory of Open Access Journals (Sweden)

    R.D. Martino

    2005-06-01

    Full Text Available Las corneanas de La Clemira se habrían generado por el efecto térmico de los granitoides de Ambargasta sobre rocas sedimentarias, en el Cámbrico medio, conservándose como colgajos kilométricos. Están compuestas por una secuencia alternada de metapelitas y metapsamitas, con el plano de estratificación original todavía reconocible (S0, dispuesto verticalmente con el techo hacia el este. Las corneanas se destacan por preservar estructuras primarias mesoscópicas de origen sedimentario (estratificación cruzada, estructuras de carga y plegamiento convoluto, únicas por sus características dentro de las metamorfitas de las Sierras Pampeanas Orientales. También se han identificado estructuras secundarias mesoscópicas, principalmente pliegues, debidas a deformación posterior al metamorfismo de contacto. A escala microscópica, se observan microestructuras de disolución por presión en motas de cordierita y orientación de la biotita de la matriz. Estas evidencias estructurales permiten establecer tres etapas evolutivas postmetamórficas: (1 acortamiento en el Cámbrico superior, paralelo a las capas, con generación de pliegues simétricos rectos, pliegues en caja asociados a niveles de despegue y pliegues por propagación de fallas; (2 alargamiento en el límite cambroordovícico, con formación de pliegues monoclinales que gradan a fallas directas; y (3 diaclasado tardío. La deformación postmetamórfica se habría desarrollado en el nivel estructural superior, por encima del frente de esquistosidad, según se deduce de las estructuras encontradas y de las condiciones de emplazamiento de los granitoides de Ambargasta (P < 0,3 GPa. Las estructuras reconocidas, a escala decimétrica, son análogas a las de las fajas corridas y plegadas en las coberteras sedimentarias.

  12. Petrología y análisis geométrico y tectónico de las milonitas de la Sierra de Copacabaña, provincia de Catamarca, República Argentina

    Directory of Open Access Journals (Sweden)

    López, J. P.

    1992-12-01

    Full Text Available A petrographic and structural study of units from Copacabana Range in the Northwestern Pampean Ranges is presented. Two facies of deformed granitoids were recognized. Rocks of both facies are classificated as mylonite schists, mylonite gneisses and protomylonites. First would have formed at temperature of 3500 C and 15 km of deep. Protomylonite would have formed at lower temperatures and deeps. Undeformed granitoids and ortogneis are also descript.Structural data and the analysis of some kinematic indicators suggest that a main shear plane strikes NNW, inclined to the east, with vergence to the west. Geometric analysis, realized in base to petrographic diagrams of c-axis of quartz and mica cleavage suggest an orthorhombic fabric.Se realiza un estudio petrológico estructural de las unidades que componen el extremo septentrional de la Sierra de Copacabana, que se localiza en el ámbito de las Sierras Pampeanas Noroccidentales. Entre éstas se reconocen dos épocas de deformación de los granitoides; de acuerdo a la clasificación de Higgins (1971 corresponden a esquistos miloníticos, gneises miloníticos y protomilonitas. Los primeros se habrían formado a temperaturas superiores a los 3500 C y a profundidades de unos 15 km, bajo un régimen cuasi plástico de deformación, mientras que las condiciones de formación de las protomilonitas corresponden a una zona de transición elástico-friccional a cuasiplástico, a temperaturas y profundidades algo menores.Además se describe también la facies granítica no deformada, que se halla en contacto neto con las anteriores y un ortogneis que representa la roca de caja en la que se instruyeron los granitoides.Los datos estructurales y observaciones de indicadores cinemáticos sugieren un plano de cizalla principal de rumbo NNW e inclinación al este, cuyo movimiento relativo es de carácter inverso, produciendo un cabalgamiento con vergencia al W. El análisis geométrico de diagramas petrof

  13. Home birth and hospital birth trends in Bo, Sierra Leone.

    Science.gov (United States)

    Jacobsen, Kathryn H; Abdirahman, Hafsa A; Ansumana, Rashid; Bockarie, Alfred S; Bangura, Umaru; Jimmy, David Henry; Malanoski, Anthony P; Sundufu, Abu James; Stenger, David A

    2012-06-01

    As of April 2010, all maternity care at government healthcare facilities in Sierra Leone is provided at no cost to patients. In late 2010, we conducted a community health census of 18 sections of the city of Bo (selected via randomized cluster sampling from 68 total sections). Among the 3421 women with a history of pregnancy who participated in the study, older women most often reported having a history of both home and hospital deliveries, while younger women showed a preference for hospital births. The proportion of lastborn children delivered at a healthcare facility increased from 71.8% of offspring 10-14 years old to 81.1% of those one to nine years old and 87.3% of infants born after April 2010. These findings suggest that the new maternal healthcare initiative has accelerated an existing trend toward a preference for healthcare facility births, at least in some urban parts of Sierra Leone. PMID:22375565

  14. CAPACITY OF RURAL WOMEN IN THE SIERRA NEVADA OF PUEBLA

    Directory of Open Access Journals (Sweden)

    Verónica Ramírez-Castel

    2015-07-01

    Full Text Available The types of skills developed by rural women in the Sierra Nevada of Puebla since their participation in the Development Partnership Link for Sierra Nevada, AC. and the effects it had on personal, family and community levels are analyzed. The research methodology used was quantitative-qualitative: questionnaire, depth interviews and participant observation. The results indicate that they acquired skills from a gender perspective, technical-productive, eco-environmental and organizational-political, in the psychomotor, cognitive and affective dimensions; they managed to transform gender relations, contribute to the food security of their families, health care basics and promote environmental stewardship. The integral development of the capacities of rural women, contributes to their formation as social actors and political life of their communities, actively focusing on local development, integrating social networking and participating in the local economy.

  15. Estructuras primarias, secundarias y evolución estructural de las corneanas de La Clemira, sierra de Ambargasta, Santiago del Estero Primary and secondary structures, and structural evolution of La Clemira hornfels from Sierra de Ambargasta, Santiago del Estero

    Directory of Open Access Journals (Sweden)

    R.D. Martino

    2005-06-01

    Full Text Available Las corneanas de La Clemira se habrían generado por el efecto térmico de los granitoides de Ambargasta sobre rocas sedimentarias, en el Cámbrico medio, conservándose como colgajos kilométricos. Están compuestas por una secuencia alternada de metapelitas y metapsamitas, con el plano de estratificación original todavía reconocible (S0, dispuesto verticalmente con el techo hacia el este. Las corneanas se destacan por preservar estructuras primarias mesoscópicas de origen sedimentario (estratificación cruzada, estructuras de carga y plegamiento convoluto, únicas por sus características dentro de las metamorfitas de las Sierras Pampeanas Orientales. También se han identificado estructuras secundarias mesoscópicas, principalmente pliegues, debidas a deformación posterior al metamorfismo de contacto. A escala microscópica, se observan microestructuras de disolución por presión en motas de cordierita y orientación de la biotita de la matriz. Estas evidencias estructurales permiten establecer tres etapas evolutivas postmetamórficas: (1 acortamiento en el Cámbrico superior, paralelo a las capas, con generación de pliegues simétricos rectos, pliegues en caja asociados a niveles de despegue y pliegues por propagación de fallas; (2 alargamiento en el límite cambroordovícico, con formación de pliegues monoclinales que gradan a fallas directas; y (3 diaclasado tardío. La deformación postmetamórfica se habría desarrollado en el nivel estructural superior, por encima del frente de esquistosidad, según se deduce de las estructuras encontradas y de las condiciones de emplazamiento de los granitoides de Ambargasta (P The hornfelses of La Clemira were generated by the thermal effect of the Ambargasta granitoids on sedimentary rocks during the Middle Cambrian, and are preserved as kilometre-size roof pendants in the granitoids. A vertical and alternating sequence of metapelites and metapsammites, conserving the original bedding (S0

  16. Securitizing Borderless Diseases: The case of Ebola in Sierra Leone

    OpenAIRE

    Hansen, Sofie; Jakshøj, Christoffer; Nielsen, Mie

    2016-01-01

    This chapter investigates how the Ebola Virus Disease Outbreak was securitised, and in turn how this securitization affected the sovereignty and development of Sierra Leone. Drawing on the Copenhagen School theory on securitization combined with Elbe’s notions of Medicalized Insecurity the chapter examines the process of securitising the Ebola outbreak. Hereafter the concept of Medicalised Nativism is applied to provide insight into the everyday effects of the outbreak on locals and to provid...

  17. Polymictic pool behavior in a montane meadow, Sierra Nevada, CA

    OpenAIRE

    Lucas, Ryan Geoffrey

    2013-01-01

    We observed polymictic behavior in stream pools in a low gradient montane meadow in the southern Sierra Nevada Mountains, California. Thermal stratification in stream pools has been observed in various environments; stratification generally persists where the buoyancy forces created by a variation in water density, as a function of water temperature, are able to overcome turbulent forces resulting from stream flow. Because the density gradient creates a relatively weak buoyancy force, low f...

  18. Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA.

    Science.gov (United States)

    Boyd, Oliver S; Jones, Craig H; Sheehan, Anne F

    2004-07-30

    Seismic tomography reveals garnet-rich crust and mantle lithosphere descending into the upper mantle beneath the southeastern Sierra Nevada. The descending lithosphere consists of two layers: an iron-rich eclogite above a magnesium-rich garnet peridotite. These results place descending eclogite above and east of high P wave speed material previously imaged beneath the southern Great Valley, suggesting a previously unsuspected coherence in the lithospheric removal process.

  19. Carbon dioxide fluxes across the Sierra de Guadarrama, Spain

    OpenAIRE

    Inclán Cuartas, Rosa; Uribe Vallejos, Carla; Torre, D. de la; Sánchez Ledesma, Dolores María; Clavero Sánchez, M. Angeles; Fernández Díaz, Ana Maria; Morante Sánchez, Ramón; Cardeña Contreras, Ana; Fernández, M.; Rubio Sánchez, Agustín

    2010-01-01

    Understanding the spatial and temporal variation in soil respiration within small geographic areas is essential to accurately assess the carbon budget on a global scale. In this study, we investigated the factors controlling soil respiration in an altitudinal gradient in a southern Mediterranean mixed pine–oak forest ecosystem in the north face of the Sierra de Guadarrama in Spain. Soil respiration was measured in five Pinus sylvestris L. plots over a period of 1 year by means of a clos...

  20. Impact of the civil war in Sierra Leone on deforestation

    OpenAIRE

    Minářová, Barbora

    2012-01-01

    The process of deforestation in Sierra Leone already started before the civil war, but it is generally assumed that the conflict exacerbated it. The present study investigated the impact of the civil war on deforestation, fallow periods and commercial logging, in the region around the Gola Rainforests National Park. Forest covers were affected by the civil war in two ways: directly through farm abandonment (i) and indirectly through defined channels (ii), such as preferences towards natural r...

  1. Lassa fever in post-conflict sierra leone.

    OpenAIRE

    Shaffer, Jeffrey G.; Grant, Donald S; John S Schieffelin; Boisen, Matt L; Augustine Goba; Hartnett, Jessica N.; Levy, Danielle C.; Yenni, Rachael E.; Moses, Lina M; Mohammed Fullah; Mambo Momoh; Mbalu Fonnie; Richard Fonnie; Lansana Kanneh; Koroma, Veronica J.

    2014-01-01

    Background Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Methodology/Principal Findings Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the po...

  2. Lassa Fever in Post-Conflict Sierra Leone

    OpenAIRE

    Shaffer, Jeffrey G.; Grant, Donald S; John S Schieffelin; Boisen, Matt L; Goba, Augustine; Hartnett, Jessica N.; Levy, Danielle C.; Yenni, Rachael E.; Moses, Lina M; Fullah, Mohammed; Momoh, Mambo; Fonnie, Mbalu; Fonnie, Richard; Kanneh, Lansana; Koroma, Veronica J.

    2014-01-01

    Background: Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Methodology/Principal Findings Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the p...

  3. Sierra Leone: Krio and the Quest for National Integration

    OpenAIRE

    Oyètádé, B. Akíntúndé; Fashole-Luke, Victor

    2008-01-01

    The Republic of Sierra Leone is a smaller country in size, population and the number of its languages than many other countries on the West African coast such as Ghana, Ivory Coast and Nigeria. A particularly interesting phenomenon is however present in the configuration of the languages present and used in the country, and how language links up the general population. Though there are two proportionately large indigenous languages spoken in the country, Temne and Mende, it is found that th...

  4. Celebrity, Violence, and the Mystic Arts in Postwar Sierra Leone

    OpenAIRE

    Anderson, Samuel Mark

    2014-01-01

    This dissertation tracks the operations of Hassan Jalloh, once a commander in Sierra Leone's devastating civil war, now self-proclaimed "King of West Africa Mystical Power and Culture." Jalloh served in the Civil Defense Forces, a pro-government militia that mobilized the imagery and practices of village hunter traditions in pursuit of local legitimacy and esoteric defense maneuvers including disappearance, metamorphosis, and bullet-proofing. Faced with disarmament and doubtful reintegration ...

  5. Tectonic control on southern Sierra Nevada topography, California

    OpenAIRE

    Mahéo, Gweltaz; Saleeby, Jason; Saleeby, Zorka; Farley, Kenneth A.

    2009-01-01

    In this study we integrate the apatite (U-Th)/He thermochronometric technique with geomorphic, structural, and stratigraphic studies to pursue the origin and evolution of topographic relief related to extensive late Cenozoic faulting in the southern Sierra Nevada. The geomorphology of this region reflects a transition from a vast region to the north characterized by nonequilibrium fluvial modification of a relict low-relief landscape, little affected by internal deformation, to a more complex...

  6. Sierra Leone Police Reform: the role of the UK government

    OpenAIRE

    Bruce Baker

    2010-01-01

    Sierra Leone's civil war left development urgently needing security and security urgently needing reform. The initial UK response was un-coordinated until the Poverty Reduction Strategy 2004 which highlighted the importance of security. The SSR review, in response, made the security-development link explicit and all state security providers together with the judiciary, oversight mechanisms and relevant NGOs were brought together under the Justice Sector Development Programme. This review of p...

  7. Reducing CO2 emissions in Sierra Leone and Ghana

    International Nuclear Information System (INIS)

    With soring population growth rates and minimal economic growth, the nations of Africa are afflicted with innumerable problems. Why then should Africa's developing countries worry about CO2 emissions? First, because agricultural activities form the backbone of most African economies; thus, these nations may be particularly vulnerable to the negative impacts of climate change. Second, acting to reduce carbon emissions will bring about more efficient energy use. All of Africa could benefit from the improved use of energy. Finally, the accumulation of CO2 in the atmosphere is a global problem with individual solutions; in order to reduce international emissions, all countries, including those in Africa, must contribute. Typical of many African countries, Ghana and Sierra Leone have among the lowest levels of energy demand per capita across the globe. primary energy demand per capita in these two West African nations equals about one quarter of the world's average and about one twentieth of the US average. This work summarizes the results of two long-term energy use and carbon emissions scenarios for Sierra Leone and Ghana. In the high emissions (HE) scenario for 2025, policy changes focused on galvanizing economic growth lead to significant increases in energy use and carbon emissions in Ghana and Sierra Leone between 1985 and 2025. In the low emissions (LE) scenario, the implementation of policies aimed specifically at curtailing CO2 emissions significantly limits the increase in carbon in both nations by 2025

  8. Environmental values and risk: A review of Sierra Club policies

    Energy Technology Data Exchange (ETDEWEB)

    Craig, P.P. [Univ. of California, Davis, CA (United States). Graduate Group in Ecology

    1999-12-01

    Sierra Club values are driven by an overriding environmental ethic. Sierra Club environmental values may be characterized by the concept of 'usufruct' a term favored by United States Founding Father Thomas Jefferson. Usufruct conveys the idea that the environment is ours to use, but not to destroy. Each generation has the obligation to pass on to future generations a world at least as environmentally rich as the one it inherited. It is appropriate to accept risk today in order to preserve the environment for generations yet to come. As viewed through the lens of its formal policies, the Sierra Club is an organization that embraces technology, but insists that technology be evaluated comprehensively, taking full account of both environmental and social externalities. The Club is 'risk averse' with respect to early introduction of technologies seen as likely to have significant negative environmental or social impact. The Club places heavy emphasis on process, which must involve the public meaningfully.

  9. Attenuation Tomography of Sierra Negra Volcano of the Galapagos Archipelago

    Science.gov (United States)

    Rodd, R.; Lees, J. M.

    2014-12-01

    Following relocation of events with the double-difference location algorithm (HypoDD), we apply tomographic methods to extract 3D attenuation models illuminating the plumbing system of the Sierra Negra Caldera of the Galapagos Archipelago. The dataset consists of 1737 events recorded from July 2009 to June 2011 on the 17-station SIGNET broadband seismic array. We use t* spectral decay methods for both P- and S- phases with the clustered locations to highlight locations where significant variations in Q suggest the presence of magma melt. While the presence of a magma sill, at least 2 km depth, is indicated by InSAR and GPS studies, the delineated magma body has not been explored in detail. The lower bound of the proposed magma accumulation is still under question and thus forms the primary target of this research. Melt replenishment and degassing of the magma sill is believed to cause inflation and/or deflation of the caldera floor. Imaging the extent of the magma sill will provide insight into the feeder system and deformation process of the Sierra Negra caldera. Detailed relocation, Qp and Qs inversion, as well as estimates of the scattering attenuation using coda-normalization technique will be presented. The close relationship between seismic attenuation and the thermal state of the magmatic system suggests we can distinguish melt and/or fluid regions within the Sierra Negra plumbing system.

  10. Tafonomía sobre asociaciones de vertebrados registradas en trampas fluviales de la Región Pampeana (Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Pomi, L. H.

    2008-12-01

    Full Text Available We describe a new taphonomic mode from a fluvial system developed in channel terraces located at the Pampean Region (Quequén Grande River, Buenos Aires, Argentina associated with natural vertical cavities («marmits». We analyzed a recent (mainly aquatic vertebrate assemblage accumulated in these cavities, which operate as bone traps. Our observations suggest that these traps have accumulated isolated specimens and live or dead complete individuals during high hydric regime (torrential rains. Skeletal part representation indicates that exists a bone selection. We compare the element differential survey with different variables (structural bone density, original representation in a skeleton, size, form and volume, concluding that selection was associated with floating capabilities of missing bones (e.g. vertebrae.Se da a conocer un nuevo modo tafonómico reconocido en un sistema fluvial ubicado en la Región Pampeana (provincia de Buenos Aires, Argentina. Éste se encuentra asociado a cavidades verticales (marmitas desarrolladas en terrazas del canal principal del río Quequén Grande. Se estudió una asociación de vertebrados actuales (en su mayoría de hábitos acuáticos acumulados en estas cavidades, las cuales actuaron como trampas para los especímenes. El estudio de la muestra y observaciones realizadas in situ, sugieren que dicha trampa acumuló individuos completos (vivos o muertos y especímenes aislados durante eventos de alto régimen hídrico (lluvias torrenciales. La representación de partes anatómicas indica una selección de elementos. Se comparó la supervivencia diferencial de cada elemento con diferentes variables (densidad ósea estructural, representación original en el esqueleto, tamaño, forma y volumen, concluyendo que la selección observada se produjo por la capacidad de flotación de los elementos ausentes (p. ej., vértebras.

  11. La estructura del Grupo Sierras Bayas en el sector norte de las sierras homónimas, noroeste de las Sierras Septentrionales de Buenos Aires The structure of Sierras Bayas Group in the north area of the homonymous hills, northwest of Sierras Septentrionales of Buenos Aires, Argentine

    Directory of Open Access Journals (Sweden)

    A.C. Massabie

    2005-03-01

    Full Text Available El Grupo Sierras Bayas, de edad precámbrica tardía, se halla integrado por las formaciones sedimentarias Villa Mónica, Cerro Largo y Loma Negra, y forman parte de la porción noroccidental de las Sierras Septentrionales de Buenos Aires. Los afloramientos principales, relativamente aislados en serranías bajas, se ubican en los alrededores de Olavarría, particularmente en las Sierras Bayas, y con menor extensión en cercanías a la localidad de Barker. La morfoestructura de conjunto de estas sedimentitas en el sector norte de las Sierras Bayas corresponde a una cubeta asimétrica levemente basculada hacia el sudsudoeste. En el Grupo Sierras Bayas, se han identificado y relevado sistemáticamente dos sistemas de plegamiento suave F1 (NE y F2 (NO que se interfieren y generan diseños de tipo 1 en domos y cubetas. Los plegamientos reconocidos, F1 y F2, de planos axiales subverticales y ejes B subhorizontales se interfieren con ángulos que varían entre 70º y 90º. Desarrollan tres órdenes de plegamiento que controlan en las escalas adoptadas para el mapeo, la posición de los afloramientos y exposiciones artificiales de las formaciones integrantes del Grupo Sierras Bayas. El fallamiento local relevado ejerce un control muy limitado sobre la disposición de las sedimentitas precámbricas plegadas, y las observaciones de campo avalan su actividad inicial con posterioridad al episodio tectónico que desarrolló los sistemas de plegamiento del Grupo Sierras Bayas. La deformación dúctil de la cubierta sedimentaria, como ha sido observado localmente, se considera que ha estado asociada con una reactivación tectónica del basamento, Complejo Buenos Aires, favorecida por las anisotropías penetrativas principales preexistentes en el macizo rocoso de granititas milonitizadas. La similitud en el diseño de los plegamientos F1 y F2, la morfoestructura general en cubeta y la falta de una secuencia definida en las relaciones de interferencia permitir

  12. Assessment of Anemia Knowledge, Attitudes and Behaviors among Pregnant Women in Sierra Leone

    Science.gov (United States)

    M'Cormack, Fredanna A. D.; Drolet, Judy C.

    2012-01-01

    Introduction: Iron deficiency anemia prevalence of pregnant Sierra Leone women currently is reported to be 59.7%. Anemia is considered to be a direct cause of 3-7% of maternal deaths and an indirect cause of 20-40% of maternal deaths. This study explores knowledge, attitudes, and behaviors of urban pregnant Sierra Leone women regarding anemia.…

  13. Curriculum Diversification Re-examined--A Case Study of Sierra Leone.

    Science.gov (United States)

    Wright, Cream A. H.

    This paper deals with a case study of secondary curriculum diversification as a vocationalization strategy in Sierra Leone. It explores diversification issues from four crucial standpoints that are distinct but highly interrelated. First, diversification is dealt with as a policy that was adopted and actively pursued by Sierra Leone for over a…

  14. 76 FR 13177 - Public Utilities Commission of Nevada and Sierra Pacific Power Company v. Tuscarora Gas...

    Science.gov (United States)

    2011-03-10

    ... and Sierra Pacific Power Company (Complainants) filed a formal complaint against Tuscarora Gas... Energy Regulatory Commission Public Utilities Commission of Nevada and Sierra Pacific Power Company v. Tuscarora Gas Transmission Company; Notice of Complaint Take notice that on February 28, 2011, pursuant...

  15. Re-imaging the Modernity of Sierra Leone and Equatorial Guinea: Africa past and Africa present

    OpenAIRE

    Codling, Rosetta

    2011-01-01

    This paper engages the concept of the imposed Modernity of Europe upon the African republics of Sierra Leone and Equatorial Guinea. Evidence of the encroachment of a ‘false’ Modernity upon Africa’s Sierra Leone and Equatorial Guinea are chronicled in the works of Donato Ndongo (Shadows of Your Black Memory) and Syl Cheney Coker (The Last Harmattan of Alusine Dunbar).

  16. Sierra Leone - Mining Sector Reform : A Strategic Environmental and Social Assessment

    OpenAIRE

    World Bank, (WB)

    2008-01-01

    The Strategic Environmental and Social Assessment (SESA) of the mining sector in Sierra Leone was undertaken in response to the Government of Sierra Leone's (GOSL) request for assistance in developing its minerals policy. The SESA will help meet long-term country development by integrating environmental and social considerations in mining sector reforms. The crucial aspect of the SESA proc...

  17. Modeling Patterns of Precipitation Phase in the Central Sierra Nevada

    Science.gov (United States)

    Strikas, O.; Pavelsky, T.

    2013-12-01

    Snowpack provides 75% of summer hydrologic flow in the western United States. This summer flow is vitally important in California, the country's leading producer of agriculture, with $43.5 billion dollars in cash receipts in 2011. Snowpack in the California Sierra Nevada has declined by approximately half from 1900 to 1990. In this study, we use the Weather Research and Forecasting (WRF) regional climate model at a 3km resolution to understand the critical temperature window at which both snow and rain fall for the Central Sierra Nevada during the 2002 water year. Results suggest that temperature and snow fraction [snowfall / (snowfall + rainfall)] share a logistic relationship with the snow fraction being 1 until approximately 272 K, then the snow fraction decreases by approximately 22%/K leveling at 0 snow fraction at 276.5 K. We further examine the spatial patterns of temperatures, precipitation amounts, and precipitation types in the Sierra Nevada to determine the areas of greatest potential snow to rain transition under a future warmer climate. Preliminary results suggest that the high risk areas are at the low to mid elevations. This research provides evidence that even a minor increase in temperature (+0.5 K) will yield changes in spring and summer hydrographs for the region. The spatial variability of IPCC temperature regime change for 2050 and 2100 will be downscaled for a higher resolution prediction of precipitation. It is currently under investigation how the proposed IPCC (A1 and B2) predictions of climate change for the region by 2050 (+2.7 K; +1.6 K ) and 2100 (+4.4 K; +2.7 K) will alter the corresponding annual river hydrographs. Given the complex topography of the Sierra Nevada, several spatial interpolations using GIS and statistical algorithms will be executed to render this high resolution (3km) output. Other future work with collaborators intends to model the agricultural risk associated with our predicted changes. This plot demonstrates the

  18. Three-dimensional Q for Sierra Negra volcano, Galapagos

    Science.gov (United States)

    Young, B. E.; Lees, J. M.; Ebinger, C. J.

    2012-12-01

    Galapagos Islands volcanoes are some of the most rapidly deforming volcanoes on Earth, yet the magma storage chambers and migration pathways are poorly imaged. Three-dimensional tomographic inversion for seismic attenuation, 1/Q, is used to image variations in subsurface structure and heterogeneity associated with magma storage and volcanic construction at Sierra Negra volcano, Galapagos Islands. P-wave power spectra were used to estimate t* (attenuation weighted, integrated slowness) in the frequency domain for local earthquakes recorded on the 15 station, broadband SIGNET array. The SIGNET network was deployed around Sierra Negra caldera and the southern part of Isabela Island between August 2009 and January 2011. A subset of 451 earthquakes was selected for attenuation analysis based on event location within the array and station coverage. The modelled spectra were used to calculate path attenuation and earthquake source parameters. The earthquake source parameters corresponding to amplitude at zero frequency (Ω0) and corner frequency (fc) relate to earthquake size and are therefore set constant across stations. Accordingly, we derive a single Ω0 and fc for each event and fix them while allowing only t* to vary. Values of t* range between 8.89 x 10-15 and 0.0525. Preliminary results show an increase in attenuation beneath the caldera starting at 1 km depth. The zone of high attenuation is more pronounced at 2 km depth and extends laterally to the east and southeast beyond the extent of the 10 km-wide caldera. Gravity anomaly and InSAR data has been used previously to model the magma chamber at Sierra Negra. Deformation modelling requires a flat-topped sill at 2 km depth (Geist et. al., 2007; Jonsson, S., 2009; Yun et. al., 2006). Our shallow, high attenuation zone matches these results, but also indicates that the attenuating bodies extend beyond the limits of the caldera beneath the SE flank of Sierra Negra. Elongate zones of higher attenuation correlate with

  19. Registro de Nephridiophaga sp. (Protista: Nephridiophagidae) en Apis mellifera (Hymenoptera: Apidae) del Sur de la región Pampeana Record of Nephridiophaga sp. (Protista: Nephridiophagidae) in Apis mellifera (Hymenoptera: Apidae) of the southern Pampas

    OpenAIRE

    Santiago Plischuk; Carlos E. Lange

    2011-01-01

    Durante estudios prospectivos tendientes a la detección de protistas asociados a ápidos en la región Pampeana, se observó la presencia de esporos ovales bicóncavos y grupos de esporos (cúmulos) en los túbulos de Malpighi de abejas de Dufaur, partido de Saavedra, sudoeste de la provincia de Buenos Aires. Los esporos maduros midieron 4,8 ± 0,05 x 2,4 ± 0,03 μm y la carga (intensidad) promedió 5,71 ± 1,49 x 10(6) esporos/abeja. Las detecciones se efectuaron entre julio y octubre de 2006 y l...

  20. PROBLEMS IN THE ADMISSION TO HIGHER EDUCATION IN THE LOWER SIERRA DE SONORA, CASE: UNIVERSITY OF SIERRA

    Directory of Open Access Journals (Sweden)

    Rubén Ángel Vásquez-Navarro

    2011-05-01

    Full Text Available The aim of this paper is to clarify the issues and find solutions to align somewhat academic models of institutions of higher average level and above found in the central highlands of the state of Sonora, as are the University of Sierra, and the CBTA 53 and confront the culture of the people of the importance of young people studying a degree in that region.The above educational institutions are located in the geographical catchment area and education, in fact, in the same population, in the northeastern state of Sonora. The mountains of Sonora had always intended to have a school of higher education. To justify the town of Montezuma as a geographically strategic point, and thanks to the efforts made by the governor in turn was as the University of Sierra opens its doors to students on the mountain in August 2002.For the analysis of the functioning of an educational institution in the rural sector, should take into account a wide range of factors, however, this work will be key to analyze the dislocation and inconsistency of educational models from an institution of higher average level in relationship to another level, which serve as a unique educational opportunities for the people of Sonora and surrounding Montezuma. In addition, the cultural aspect, which reflects a regional behavior of the inhabitants of the region. La Sierra University is located in the mountainous region of the state of Sonora, in the town of Montezuma, with a catchment area of more than 30 municipalities in this area, which lacked a college until recently time.

  1. Water quality associated public health risk in Bo, Sierra Leone.

    Science.gov (United States)

    Jimmy, David H; Sundufu, Abu J; Malanoski, Anthony P; Jacobsen, Kathryn H; Ansumana, Rashid; Leski, Tomasz A; Bangura, Umaru; Bockarie, Alfred S; Tejan, Edries; Lin, Baochuan; Stenger, David A

    2013-01-01

    Human health depends on reliable access to safe drinking water, but in many developing countries only a limited number of wells and boreholes are available. Many of these water resources are contaminated with biological or chemical pollutants. The goal of this study was to examine water access and quality in urban Bo, Sierra Leone. A health census and community mapping project in one neighborhood in Bo identified the 36 water sources used by the community. A water sample was taken from each water source and tested for a variety of microbiological and physicochemical substances. Only 38.9% of the water sources met World Health Organization (WHO) microbial safety requirements based on fecal coliform levels. Physiochemical analysis indicated that the majority (91.7%) of the water sources met the requirements set by the WHO. In combination, 25% of these water resources met safe drinking water criteria. No variables associated with wells were statistically significant predictors of contamination. This study indicated that fecal contamination is the greatest health risk associated with drinking water. There is a need to raise hygiene awareness and implement inexpensive methods to reduce fecal contamination and improve drinking water safety in Bo, Sierra Leone. PMID:22350346

  2. El registro de la pequena edad de hielo en lagunas pampeanas The record of the Little Ice Age in the Pampean lakes

    Directory of Open Access Journals (Sweden)

    Cecilia Laprida

    2009-12-01

    Full Text Available Se conoce como Pequeña Edad de Hielo (LIA al episodio acontecido entre el siglo 16 y mediados del siglo 19, durante el cual el clima en Europa se tornó frío y ocasionalmente tormentoso. En ciertas partes de Europa, las observaciones instrumentales lo abarcan parcialmente, pero para Sudamérica no se dispone de registros instrumentales contemporáneos a dicho evento. Con el objetivo de obtener nuevas evidencias para el período comprendido por la Pequeña Edad de Hielo en la llanura pampeana, se analizaron testigos cortos de la laguna de Chascomús y de la laguna del Monte los que, de acuerdo a dataciones AMS, abarcan los últimos 500 años. Ambos testigos constan de tres secuencias granodecrecientes. El análisis del registro de la laguna de Chascomús ha permitido reconocer un período benigno desde fines del siglo 15 hasta alrededor del 1700, cuando se evidencia una retracción de la laguna que inaugura un período seco. Este episodio habría continuado por casi 150 años y se revierte alrededor de 1850, momento a partir del cual los eventos de excesos hídricos comenzaron a dominar el escenario pampeano. La base del testigo de la laguna de Monte fue datada en 1441-1494 AD. Si bien el modelo de edades para este testigo aún no ha podido ser bien establecido, los eventos de Chascomús y Monte podrían ser correlacionables y expresar tendencias seculares regionales de la humedad.The Little Ice Age (LIA is a climate episode between the 16th and middle 19th centuries, characterized in Europe by colder temperatures and occasionally stormy weather. In certain areas of Europe, long instrumental observations record the Little Ice Age partially; however, in the pampean region meteorological data only started about one hundred years ago. The objective of this contribution is to provide new evidences about the Little Ice Age in the Pampean plain based on lake cores. Short cores of Chascomús and Monte lakes were analyzed and, according to AMS data

  3. Geocronología, paleoambientes y paleosuelos holocenos en la región pampeana Holocene geochronology, paleoenvironments and paleosoils in the Pampean region

    Directory of Open Access Journals (Sweden)

    E. Fucks

    2007-09-01

    Full Text Available Las condiciones paleoambientales de la región pampeana durante el Holoceno, generaron diferentes superficies de estabilización del paisaje, permitiendo la formación de suelos tanto en ambientes de la llanura marina costera como en ambientes continentales. El análisis de diferentes perfiles geológicos en cuatro localidades y sus áreas de influencia en el NE y E de la provincia de Buenos Aires, permitieron identificar eventos pedogenéticos ubicados entre circa 4.500 años AP - 3.500 años 14C AP y circa 1.700 años 14C AP, en ambientes de la llanura marina costera y eventos pedogenéticos en planicies de inundación, ubicados cronológicamente con posterioridad a los circa 8.500- 8.000 años 14C AP, finalizando 2.000 años 14C AP. La cronología radiocarbónica permitió también: 1 ubicar cronológicamente el tope de la depositación del Miembro Guerrero de la Formación Luján dentro del Holoceno temprano (circa 8.500 años 14C AP; 2 ubicar el lapso máximo de depositación del sedimento denominado aluvio actual, desde el Holoceno tardío (circa 2.500 años 14C AP hasta los depósitos actuales donde se desarrolla un suelo muy incipiente; 3 datar eventos pedogenéticos dentro del aluvio actual en circa 1.700 años 14C AP; 4 estimar el retiro del máximo transgresivo del Holoceno y el comienzo de condiciones fluviales (circa 4.500 - 4.200 años 14C AP.The palaeoenvironmental conditions in the Pampean region during the Holocene, generated different surfaces of landscape stabilization, making possible the formation of soils in coastal marine plains and continental environments. The analyses of different geological profiles in four localities and areas of influence (NE and E of Buenos Aires province, permitted to identify pedogenetic events: 1 in coastal marine plain environments, located among circa 4500 - 3500 14C years BP and circa 1700 14C years BP; 2 in flood plains, located chronologically later to circa 8500 - 8000 14C years BP

  4. Botanical novelties from Sierra de Maigualida, southern Venezuela. II

    Directory of Open Access Journals (Sweden)

    Grande, José R.

    2012-06-01

    Full Text Available Four new species, Siphocampylus acanthidiotrichus J.R. Grande (Campanulaceae, Phyllanthus huberi Riina & P.E. Berry (Phyllanthaceae, Sohnreyia maigualidensis J.R. Grande & Kallunki (Rutaceae, and Turnera maigualidensis J.R. Grande & Arbo (Turneraceae are described and illustrated from the summit areas of Sierra de Maigualida in the Gua - yana Highlands of southern Venezuela. To date, one genus, 32 spe cies, one subspecies, and one variety of angiosperms are known only from the Maigualida meadows and shrublands, between 1800 m and the highest elevation areas at 2400 m. Here we describe the first iteroparous species for the genus Sohnreyia K. Krause, a Turnera L. species with apically villose, apiculate petals, and a Siphocampylus Pohl species with aculeiform hairs and pinnatisect leaves. The new species, Siphocampylus acanthidiotrichus, together with S. Tillettii Steyerm., represents a morphologically distinct subgroup within the genus.

    Se describen e ilustran cuatro especies nuevas procedentes de las cumbres de la Sierra de Maigualida: Siphocampylus acanthidiotrichus J.R. Grande (Campanulaceae, Phyllanthus huberi Riina & P.E. Berry (Phyllanthaceae, Sohnreyia maigualidensis J.R. Grande & Kallunki (Rutaceae y Turnera maigualidensis J.R. Grande & Arbo (Turneraceae. Hasta ahora un género, 32 especies, una subespecie y una variedad de angiospermas se conocen exclusivamente de la Sierra de Maigualida, y todas ellas proceden de herbazales y arbustales desarrollados entre los 1800 m y las áreas más altas, a 2400 m. Aquí, se describen por primera vez una especie iterópara del género Sohnreyia K. Krause (Rutaceae, una especie de Turnera L. con pétalos apiculados apicalmente vilosos y una especie de Siphocampylus Pohl con pelos aculeiformes y hojas pinnatisectas. La nueva especie Siphocampylus acanthidiotrichus representa

  5. [The indigenous population of Sierra Norte de Puebla].

    Science.gov (United States)

    Marquez Gonzalez, G

    1991-06-01

    The northern sierra region of Pueblo, Mexico, contains 1496 communities in 65 municipios and covers 1/4 of the area of the state of Puebla. The topography is steep and mountainous, and the area is inaccessible. The region contains the 3 principal zones of Mesoamerica, hot lands from sea level to 700 meters above sea level, temperate zones from 700-1500 meters, and cold country from 1500-2000 meters above sea level. Most of the population resides in the temperate and cold lands, but the hot zones are economically important. Little is known of the prehistory of the area. The Totonac were believed to have been the earliest settlers. In the mid-15th century numerous Nahua groups came to the area. In the late 15th century the region fell to the Aztecs, but their dominion was cut short by the arrival of the Spanish. Spanish penetration was relatively slow because of the difficult terrain and the lack of precious metals desired by the Spanish. The introduction of coffee cultivation in the late 19th century accelerated the adoption of urban-mestizo sociocultural and commercial elements by the indigenous population. The population of the northern sierra increased from 752,656 in 1980 to 965,976 in 1990. The 1980 census reported that 259,140 persons spoke indigenous languages, including 179,677 who spoke Nahuatl, 66,020 Totonaco, and 4921 Otomi. The most important cities are located on paved roads: Teziutland, Zacatlan, Hauachinango, and Zacapoaxtla. The municipios with predominantly monolingual indigenous populations are concentrated in the most difficult to reach areas of the central sierra massif. The region is characterized by temporary and permanent emigration of the indigenous population. The main reasons for emigration are lack of land and of alternative sources of employment, and desire for education. During the months August-December, known as the time of hunger, there is seasonal migration of household heads in search of work as laborers in cane cutting, tobacco

  6. Morfometría dental aplicada al análisis de los procesos de diferenciación poblacional en el sudeste de la Región Pampeana y norte de Patagonia durante el Holoceno Tardío

    Directory of Open Access Journals (Sweden)

    Bernal, Valeria

    2005-01-01

    Full Text Available El objetivo del presente trabajo es analizar la variabilidad en la morfometría dental en muestras de restos óseos humanos del SE de la Región Pampeana asignables a distintos momentos del Holoceno tardío y comparar, desde un punto de vista espacial, el grado de similitud morfológica con muestras procedentes del NE de Patagonia (valles de Río Negro y Chubut, San Blas, Isla Gama. Se relevaron los diámetros mesiodistal y bucolingual medidos a nivel del margen cervical en la totalidad de las piezas dentales permanentes correspondientes a 130 individuos de ambos sexos. Las medidas obtenidas fueron empleadas en análisis estadísticos multivariados con el fin de evaluar el grado similitud morfológica entre las muestras. Los resultados obtenidos indican que: 1- hay diferencias entre las muestras procedentes del SE de la Región Pampeana correspondientes al Holoceno tardío inicial y final, caracterizándose estas últimas por un mayor tamaño dental; 2- la muestra del SE de la Región Pampeana correspondiente al Holoceno tardío final presenta mayor similitud morfológica con la muestra más tardía del valle de Río Negro; 3- existen variaciones cronológicas en el tamaño dental entre las muestras procedentes del NE de Patagonia.

  7. DNA sequences of troglobitic nicoletiid insects support Sierra de El Abra and the Sierra de Guatemala as a single biogeographical area: Implications for Astyanax

    Directory of Open Access Journals (Sweden)

    Luis Espinasa

    2014-03-01

    Full Text Available The blind Mexican tetra fish, Astyanax mexicanus, has become the most influential model for research of cave adapted organisms. Many authors assume that the Sierra de Guatemala populations and the Sierra de El Abra populations are derived from two independent colonizations. This assumption arises in part from biogeography. The 100 m high, 100 m wide Servilleta Canyon of the Boquillas River separates both mountain ranges and is an apparent barrier for troglobite dispersion. Anelpistina quinterensis (Nicoletiidae, Zygentoma, Insecta is one of the most troglomorphic nicoletiid silverfish insects ever described. 16S rRNA sequences support that this species migrated underground to reach both mountain ranges within less than 12,000 years. Furthermore, literature shows a plethora of aquatic and terrestrial cave restricted species that inhabit both mountain ranges. Thus, the Servilleta canyon has not been an effective biological barrier that prevented underground migration of troglobites between the Sierra de Guatemala and the Sierra de El Abra. The Boquillas River has changed its course throughout time. Caves that in the past connected the two Sierras were only recently geologically truncated by the erosion of the new river course. It is likely that, with the geological changes of the area and throughout the 2-8 million years of evolutionary history of cave Astyanax, there have been opportunities to migrate across the Servilleta canyon.

  8. Ebola Virus Disease in Children, Sierra Leone, 2014–2015

    Science.gov (United States)

    Naveed, Asad; Wing, Kevin; Gbessay, Musa; Ross, J.C.G.; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohammed Boie; Baion, David; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia A.; Gibb, Diana M.; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

    2016-01-01

    Little is known about potentially modifiable factors in Ebola virus disease in children. We undertook a retrospective cohort study of children Ebola holding units in the Western Area, Sierra Leone, during 2014–2015 to identify factors affecting outcome. Primary outcome was death or discharge after transfer to Ebola treatment centers. All 309 Ebola virus–positive children 2 days–12 years old were included; outcomes were available for 282 (91%). Case-fatality was 57%, and 55% of deaths occurred in Ebola holding units. Blood test results showed hypoglycemia and hepatic/renal dysfunction. Death occurred swiftly (median 3 days after admission) and was associated with younger age and diarrhea. Despite triangulation of information from multiple sources, data availability was limited, and we identified no modifiable factors substantially affecting death. In future Ebola virus disease epidemics, robust, rapid data collection is vital to determine effectiveness of interventions for children. PMID:27649367

  9. Indigenousness without ethnicity in the Sierra Norte of Oaxaca

    Directory of Open Access Journals (Sweden)

    ROSA GUADALUPE MENDOZA ZUANY

    2014-08-01

    Full Text Available This article analyses the relationship between ethnic, indigenous and community-based identities in the communities of Ixtlan and Guelatao in the Sierra Norte of Oaxaca, Mexico. Local identities and sense of belonging to the communities prevail over ethnic identification amongst the inhabitants of these communities. The strengthening of local (community-based identity has been achieved through an internal social organisation and categorisation of the inhabitants based on their origin as a mechanism of integration, particularly in diverse communities with large numbers of outsiders. Parallel to this, new ways of defining indigenousness, without ethnic claims, are emerging through making reference to the practice of comunaliddadand attachment to localities/communities.

  10. Element Verification and Comparison in Sierra/Solid Mechanics Problems

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Yuki; Roth, William

    2016-05-01

    The goal of this project was to study the effects of element selection on the Sierra/SM solutions to five common solid mechanics problems. A total of nine element formulations were used for each problem. The models were run multiple times with varying spatial and temporal discretization in order to ensure convergence. The first four problems have been compared to analytical solutions, and all numerical results were found to be sufficiently accurate. The penetration problem was found to have a high mesh dependence in terms of element type, mesh discretization, and meshing scheme. Also, the time to solution is shown for each problem in order to facilitate element selection when computer resources are limited.

  11. Ebola Virus Disease in Children, Sierra Leone, 2014-2015.

    Science.gov (United States)

    Fitzgerald, Felicity; Naveed, Asad; Wing, Kevin; Gbessay, Musa; Ross, J C G; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohammed Boie; Baion, David; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia A; Gibb, Diana M; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

    2016-10-01

    Little is known about potentially modifiable factors in Ebola virus disease in children. We undertook a retrospective cohort study of children <13 years old admitted to 11 Ebola holding units in the Western Area, Sierra Leone, during 2014-2015 to identify factors affecting outcome. Primary outcome was death or discharge after transfer to Ebola treatment centers. All 309 Ebola virus-positive children 2 days-12 years old were included; outcomes were available for 282 (91%). Case-fatality was 57%, and 55% of deaths occurred in Ebola holding units. Blood test results showed hypoglycemia and hepatic/renal dysfunction. Death occurred swiftly (median 3 days after admission) and was associated with younger age and diarrhea. Despite triangulation of information from multiple sources, data availability was limited, and we identified no modifiable factors substantially affecting death. In future Ebola virus disease epidemics, robust, rapid data collection is vital to determine effectiveness of interventions for children. PMID:27649367

  12. Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Reyes-Cortes, Ignacio Alfonso

    The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered

  13. Enteric fever in a British soldier from Sierra Leone.

    Science.gov (United States)

    Osborne, Lucy G; Brown, M; Bailey, M S

    2016-06-01

    Enteric fever (typhoid and paratyphoid) remains a threat to British troops overseas and causes significant morbidity and mortality. We report the case of a soldier who developed typhoid despite appropriate vaccination and field hygiene measures, which began 23 days after returning from a deployment in Sierra Leone. The incubation period was longer than average, symptoms started 2 days after stopping doxycycline for malaria chemoprophylaxis and initial blood cultures were negative. The Salmonella enterica serovar Typhi eventually isolated was resistant to amoxicillin, co-amoxiclav, co-trimoxazole and nalidixic acid and had reduced susceptibility to ciprofloxacin. He was successfully treated with ceftriaxone followed by azithromycin, but 1 month later he remained fatigued and unable to work. The clinical and laboratory features of enteric fever are non-specific and the diagnosis should be considered in troops returning from an endemic area with a febrile illness. Multiple blood cultures and referral to a specialist unit may be required.

  14. Uranium mining in Sierra Pintada: knowledge, epistemic communities and development

    International Nuclear Information System (INIS)

    This paper analyses the conflict triggered by the National Atomic Energy Commission of Argentina (CNEA) proposing to re-open the Mining Complex of Sierra Pintada, in San Rafael, Province of Mendoza. Since 2004 when the Commission submitted the first report to the Ministry of Public Works and Environment of Mendoza to obtain the necessary permission to restart the works in the mine, several protests have taken place and many legal measures were taken in order to stop any resuming attempts. This study argues that, although CNEA has been an epistemic community capable of applying their policy proposals in the nuclear field, their technical knowledge is currently not sufficient to design a policy, and moreover, to hold that they are working for local and sustainable development. Only 'puzzling' 'with actors' paradigms and knowledge is possible to fit together their demands and achieve a public policy, or solution, for this problem. (author)

  15. Ebola response in Sierra Leone: The impact on children.

    Science.gov (United States)

    Fitzgerald, Felicity; Awonuga, Waheed; Shah, Tejshri; Youkee, Daniel

    2016-07-01

    The West African Ebola virus disease (EVD) outbreak is the largest ever seen, with over 28,000 cases and 11,300 deaths since early 2014. The magnitude of the outbreak has tested fragile governmental health systems and non-governmental organizations (NGOs) to their limit. Here we discuss the outbreak in the Western Area of Sierra Leone, the shape of the local response and the impact the response had on caring for children suspected of having contracted EVD. Challenges encountered in providing clinical care to children whilst working in the "Red Zone" where risk of EVD is considered to be highest, wearing full personal protective equipment are detailed. Suggestions and recommendations both for further research and for operational improvement in the future are made, with particular reference as to how a response could be more child-focused. PMID:27177732

  16. Cretaceous stratigraphy of sierra de Beauvoir, Fuegian Andes, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel R. Martinioni

    2013-03-01

    Full Text Available The Cretaceous stratigraphy north of Lago Fagnano, Tierra del Fuego, was poorly known until the last decade of the twentieth century. Stratigraphic, sedimentologic, and paleontological observations in sierra de Beauvoir and surroundings enabled the recognition of two main packages of dominant marine mudstone. 1 A more than 450 m thick package of slate, shale and mudstone, constituted by the revised Lower Cretaceous Beauvoir Formation. A type locality in the core of sierra de Beauvoir, with diagnostic Aptian-Albian fossils including inoceramids of the Inoceramus neocomiensis group and Aucellina sp., is proposed for this unit. 2 A more than 1,500 m thick, mudstone-dominated, but sandier upward, package consisting of at least three Upper Cretaceous units. Arroyo Castorera Formation (nom. nov. bears Turonian inoceramids of the I. hobetsensis group and I. cf. lamarcki. Río Rodríguez Formation (nom. nov. has Coniacian inoceramids, cf. Cremnoceramus sp. Policarpo Formation bears poorly preserved ammonites (Grossouvrites sp., Maorites sp., and Diplomoceras sp., together with diagnostic Maastrichtian dinocysts (Manumiella spp. complex, Operculodinium cf. azcaratei, some specimens of Fibrocysta-Exochosphaeridium complex, and Palaeocystodinium granulatum. Both packages were deposited in deep-marine environments and show, as a whole, a coarsening upward trend in the succession of Cretaceous rocks. Beauvoir Formation is part of the back-arc basin-fill of the former Rocas Verdes marginal basin. Arroyo Castorera Formation appears as a transition to the initiating Late Cretaceous Austral foreland basin evolution, clearly represented by turbiditic deposits of Río Rodríguez and Policarpo formations that were progressively accumulated in front of the rising Fuegian Andes.

  17. Knowledge of breast cancer in women in Sierra Leone

    Directory of Open Access Journals (Sweden)

    JHEE Shepherd

    2006-09-01

    Full Text Available Breast cancer has been described as one of the life-threatening diseases affecting women and is a major problem in women’s health issues. The unrecorded number of cases of breast lumps and breast cancer observed in women in Sierra Leone prompted the researcher to organize a “Breast Week” during which 1 200 women were educated on breast cancer and the importance of breast health. This research is a follow up of the “Breast Week” which was organized in Freetown, Sierra Leone The specific objective of this study was to assess whether the knowledge and teachings given to the women who participated in this project was fully understood. A sample size of 120 women (10% who participated in the “Breast Week” was obtained through systematic sampling. A quantitative approach was adopted and a structured interview schedule guided the data collection process. The data were processed through use of SPSS and Microsoft Excel. Texts from open ended questions were categorized and frequency counts were applied to the data. It was found that the majority (96.6% of the women had some knowledge of breast cancer. They linked breast cancer to the signs and symptoms associated with it and were able to describe the disease as one that kills women if not promptly detected and/or treated appropriately. Findings indicate that the majority of the women are aware of the dangers of the disease and had knowledge of someone who had died of breast cancer (59.2%. An assessment of the effectiveness of knowledge on breast cancer showed that these women could identify breast cancer as a disease that affects women and may cause death if not detected on time.

  18. Critical Habitat for the Sierra Nevada Bighorn Sheep (Ovis canadensis californiana)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas designated as critical habitat for the Sierra Nevada Bighorn Sheep. Critical habitat for the species occurs in twelve units: Mount...

  19. 76 FR 44493 - Revisions to the California State Implementation Plan, Northern Sierra Air Quality Management...

    Science.gov (United States)

    2011-07-26

    ... Management District, Sacramento Metropolitan Air Quality Management District, and South Coast Air Quality... taking direct final action to approve revisions to the Northern Sierra Air Quality Management District (NSAQMD), Sacramento Metropolitan Air Quality Management District (SMAQMD), and South Coast Air...

  20. 76 FR 44535 - Revisions to the California State Implementation Plan, Northern Sierra Air Quality Management...

    Science.gov (United States)

    2011-07-26

    ... Management District, Sacramento Metropolitan Air Quality Management District, and South Coast Air Quality... proposing to approve revisions to the Northern Sierra Air Quality Management District (NSAQMD), Sacramento Metropolitan Air Quality Management District (SMAQMD), and South Coast Air Quality Management District......

  1. Contested Jurisdictions: Legitimacy and Governance at the Special Court for Sierra Leone

    OpenAIRE

    Kendall, Sara

    2009-01-01

    The Special Court for Sierra Leone, established in 2002 to adjudicate crimes committed during a decade-long conflict, represents a new form of tribunal. Its "hybrid" structure was designed to address the domestic populace more directly than at previous international criminal tribunals. The Special Court's architects claimed that the Court's physical location in Sierra Leone and its inclusion of domestic law would generate greater awareness of and participation in its transitional justice ob...

  2. Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

    OpenAIRE

    Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz,Lola; Bonet, Francisco Javier; Zamora, Regino

    2016-01-01

    In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and ani...

  3. Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

    OpenAIRE

    Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz,Lola; Bonet-García, Francisco Javier; Zamora, Regino

    2016-01-01

    Abstract In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transec...

  4. Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain)

    OpenAIRE

    Antonio Jesús Pérez-Luque; Francisco Javier Bonet; Ramón Pérez-Pérez; Rut Aspizua; Juan Lorite; Regino Zamora

    2014-01-01

    Abstract The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain). The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened) from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic in...

  5. Ebola Virus Disease Complications as Experienced by Survivors in Sierra Leone

    OpenAIRE

    Tiffany, Amanda; Vetter, Pauline; Mattia, John; Dayer, Julie-Anne; Bartsch, Maria; Kasztura, Miriam; Sterk, Esther; Tijerino, Ana Maria; Kaiser, Laurent; Ciglenecki, Iza

    2016-01-01

    Background.  Thousands of people have survived Ebola virus disease (EVD) during the ongoing outbreak. However, data about the frequency and risk factors of long-term post-EVD complications remain scarce. We describe the clinical characteristics of EVD survivors followed in a survivor clinic in Freetown, Sierra Leone. Methods.  A survivor clinic opened within an Ebola treatment center compound in Freetown, Sierra Leone. At each visit, clinical and psychological assessments were conducted and f...

  6. Noteworthy records of two species of mammals in the Sierra Madre de Oaxaca, Mexico Registros notables de dos especies de mamíferos de la Sierra Madre de Oaxaca, México

    OpenAIRE

    Miguel Briones-Salas; María D. Luna-Krauletz; Ariadna Marín-Sánchez; Jorge Servín

    2006-01-01

    We conducted mammal surveys in the Sierra Madre de Oaxaca (Sierra Norte) in Oaxaca, Mexico, and recorded the occurrence of two conspicuous mammal species: the spider monkey (Ateles geoffroyi vellerosus) and the coyote (Canis latrans cagottis). Spider monkeys has not been previously recorded in the Sierra Madre de Oaxaca, and coyotes have not been previously observed in Mexico at elevations as high as the present one (3 200 mas1) in the Sierra Madre de Oaxaca.Se efectuaron colectas de mamífero...

  7. Anomalías del campo gravitatorio y magnético terrestre en la sierra de Socoscora, provincia de San Luis Earth gravity and magnetic field anomalies in the Sierra of Socoscora, San Luis province

    Directory of Open Access Journals (Sweden)

    J Kostadinoff

    2003-12-01

    Full Text Available La sierra de Socoscora se ubica en forma meridiana y se manifiesta como un escalón al noroeste de la Sierra Grande de San Luis. En la sierra de Socoscora las rocas del basamento están representadas por metamorfitas de alto grado con escasos afloramientos de metabasitas. Las mediciones del campo gravitatorio y magnético indican la presencia de un volumen mayor de estas rocas en su subsuelo. Los excesos de masa en esta sierra se hallan definidas por anomalías gravimétricas de Bouguer (residuales positivas similares a las encontradas en la Sierra Grande de San Luis. La magnetometría indica, a partir de las respuestas positivas, la existencia de rocas máficas con concentraciones anómalas de minerales magnéticos.The Sierra de Socoscora is a north - south trending mountain range, located nortwest of the Sierra Grande of San Luis. The basament is constituted by high grade metamorphic rocks with few associated metabasites. Earth gravity and magnetic field measurements are indicative of the presence of bigger volumes of mafic rocks below the surface, which carry anomalous concentrations of ferromagnetic and/or paramagnetic minerals (magnetite and/or sulfides. An excess of mass below this Sierra is shown by Bouguer gravimetric anomalies with magnitudes similar to those measured in the Sierra Grande de San Luis. Positive magnetic anomalies are indicative of the presence of mafic rocks with anomalous concentrations of magnetic minerals.

  8. Sierra Elvira limestone: petrophysical characteristics of an Andalusian heritage stone

    Directory of Open Access Journals (Sweden)

    Valverde, I.

    2008-06-01

    Full Text Available “Sierra Elvira stone” is one of the ornamental building stones most widely used in the historical monuments of eastern Andalusia. A Liassic age limestone, it appears in the central section of the Baetic Mountains and more specifically in the Middle Subbaetic domain. While the most common variety is a crinoid limestone, a micritic limestone of the same age has also been quarried, albeit in much smaller quantities. These stones form very thick beds, up to nearly 5 m deep, that run in consistently parallel lines and have a dip angle that facilitates quarrying.With petrographic, physical and mechanical properties that ensure stone strength and durability, it is a high quality building material suitable for both structural and ornamental purposes. These properties can be attributed to the minimal open porosity and concomitant excellent water resistance that characterize the stone, as well as to its high mechanical strength and low textural anisotropy, both elastic and mechanical. With such attributes, the stone can be successfully used for any number of purposes, including decorative stonework (portals, fountains, plinths, structural members (column shafts and bases or urban curbing and paving. Intervention on Sierra de Elvira limestone structures should be limited to cleaning or repair, for consolidating or protective materials are scantly effective.La “Piedra de Sierra Elvira” constituye una de las piedras ornamentales más significativas del Patrimonio Arquitectónico de Andalucía Oriental. Es una roca caliza del Lias que aflora en el Subbético Medio del sector central de las Cordilleras Béticas. El litotipo más explotado es una caliza con crinoides, en bastante menor importancia se ha extraído también otra caliza micrítica de la misma edad. Los bancos son muy potentes, en algunos casos de más de 5 m, con un paralelismo constante y un buzamiento que favorece su explotación en los frentes de cantera.Sus caracter

  9. Monitoring lichens diversity and climatic change in Sierra Nevada (Spain

    Directory of Open Access Journals (Sweden)

    Fernández Calzado, M.ª R.

    2013-12-01

    Full Text Available Lichens are common organisms in high mountain zones, where they play an important role in ecosystem balance. In recent years, the increasing interest in understanding more about their interactions with abiotic factors has prompted several investigations, some of which have proved their value as bioindicators of climatic conditions. In this context, focusing on climatic change effects on high mountain vascular plants and supported by the Global Observation Research Initiative in Alpine Environments project (GLORIA, we have monitored for the first time the lichens biodiversity in Sierra Nevada with the intention of studying the alterations caused by the process of climatic change. The aim of this paper is to explain the monitoring experience developed on the massif and contribute to the first results from the biodiversity and statistical analysis of the sampling data.Los líquenes son organismos comunes en las zonas de alta montaña donde juegan un importante papel en el equilibrio de los ecosistemas. En los últimos años, el creciente interés por entender más acerca de sus interacciones con los factores abióticos ha motivado diversas investigaciones, algunas de las cuales han demostrado su valor como bioindicadores de las condiciones climáticas. En este contexto, centrándonos en los efectos del cambio climático en plantas vasculares de alta montaña y respaldados por el proyecto “Iniciativa para la investigación y el seguimiento global de los ambientes alpinos (GLORIA”, se ha monitorizado por primera vez la diversidad de líquenes en Sierra Nevada con la intención de estudiar las posibles alteraciones que esta pueda sufrir causadas por el proceso de cambio climático. El objetivo de este artículo es el de dar a conocer la experiencia de seguimiento en el macizo y aportar los primeros resultados procedentes del análisis, tanto de la biodiversidad como estadístico, de los datos de muestreo.

  10. Deformation of the late Miocene to Pliocene Inyo Surface, eastern Sierra region, California

    Science.gov (United States)

    Jayko, A.S.

    2009-01-01

    A middle and late Miocene erosion surface, the Inyo Surface, underlies late Miocene mafic flows in the White Mountains and late Miocene and (or) early Pliocene flows elsewhere in the eastern Sierra region. The Inyo Surface is correlated with an erosion surface that underlies late Miocene mafic flows in the central and northern Sierra Nevada. The mafic flows had outpourings similar to flood basalts, although of smaller volume, providing paleohorizontal and paleolowland indicators. The flows filed and locally topped the existing landscape forming broad plateau-like flats. Topographic relief in the region was characterized by weathered and rounded slopesp rior to late Miocene mafic magmatism. Relicts of the older landscape lie adjacent to late Miocene and early Pliocene basalt-covered lowlands that now occur within the crests of ranges that have 2500-3000 m relief and dramatically steep escarpments. Late Miocene mafic flows that lie on the crest of the Sierra Nevada adjacent to the White Mountains predate significant activity on the Sierra Nevada frontal fault zone. These deposits and accompanying erosion surfaces provide excellent strain markers for reconstructing part of the Walker Lane north of the Garlock fault and west of the Amargosa drainage, here referred to as the eastern Sierra region. The Inyo Surface is a compound erosional surface that records at least four major erosion events during the Cenozoic. These four surfaces were first recognized on the Kern Plateau and named from oldest to youngest, the Summit Upland, the Subsummit Plateau, the Chagoopa Plateau, and the Canyon. The three older surfaces have also been subsequently modifi ed by Pleistocene glaciation. The compound erosion surface, which is locally overlain by late Miocene mafic flows in the northern and central Sierra Nevada, is here referred to as the Lindgren Surface. Correlatives in the eastern Sierra region are found in the White Mountains, Inyo Mountains, Darwin Plateau, Coso Range, and

  11. California spotted owls: Chapter 5 in Managing Sierra Nevada forests

    Science.gov (United States)

    Roberts, Suzanne C.; Brooks, Matthew L.

    2012-01-01

    California spotted owls (Strix occidentalis occidentalis) are habitat specialists that are strongly associated with late-successional forests. For nesting and roosting, they require large trees and snags embedded in a stand with a complex forest structure (Blakesley et al. 2005, Gutiérrez et al. 1992, Verner et al. 1992b). In mixedconifer forests of the Sierra Nevada, California spotted owls typically nest and roost in stands with high canopy closure (≥75 percent) [Note: when citing studies, we use terminology consistent with Jennings et al. (1999), however, not all studies properly distinguish between canopy cover and closure and often use the terms interchangeably (see chapter 14 for clarification)] and an abundance of large trees (>24 in (60 cm) diameter at breast height [d.b.h.]) (Bias and Gutiérrez 1992, Gutiérrez et al. 1992, LaHaye et al. 1997, Moen and Gutiérrez 1997, Verner et al. 1992a). The California spotted owl guidelines (Verner et al. 1992b) effectively summarized much of the information about nesting and roosting habitat. Since that report, research on the California spotted owl has continued with much of the new information concentrated in five areas: population trends, barred owl (Strix varia) invasion, climate effects, foraging habitat, and owl response to fire.

  12. Sierra Stars Observatory Network: An Accessible Global Network

    Science.gov (United States)

    Williams, Richard; Beshore, Edward

    2011-03-01

    The Sierra Stars Observatory Network (SSON) is a unique partnership among professional observatories that provides its users with affordable high-quality calibrated image data. SSON comprises observatories in the Northern and Southern Hemisphere and is in the process of expanding to a truly global network capable of covering the entire sky 24 hours a day in the near future. The goal of SSON is to serve the needs of science-based projects and programs. Colleges, universities, institutions, and individuals use SSON for their education and research projects. The mission of SSON is to promote and expand the use of its facilities among the thousands of colleges and schools worldwide that do not have access to professional-quality automated observatory systems to use for astronomy education and research. With appropriate leadership and guidance educators can use SSON to help teach astronomy and do meaningful scientific projects. The relatively small cost of using SSON for this type of work makes it affordable and accessible for educators to start using immediately. Remote observatory services like SSON need to evolve to better support education and research initiatives of colleges, institutions and individual investigators. To meet these needs, SSON is developing a sophisticated interactive scheduling system to integrate among the nodes of the observatory network. This will enable more dynamic observations, including immediate priority interrupts, acquiring moving objects using ephemeris data, and more.

  13. Geological and geophysical investigations at Sierra del Medio massif - Argentine

    International Nuclear Information System (INIS)

    Geological investigations were performed at Sierra del Medio (Chubut Province), a mountainous massif of about 25 km by 8 km of migmatic origin, which emerges from a depressed tectonic trench or graben called Pampa de Gastre. The most ancient rocks belong to biotitic and anphibolic schist that passed almost entirely to tonalitoid migmatites with a second process producing granitic rocks. Boreholes were drilled on the basis of conclusions from Landsat satellites imagery and aerial photographic sets, folowed by field work on geological, petrographic, geophysical and hydrogeological features at surface, structural interpretation supported by geostatistical computations. Two sets of boreholes were drilled to investigate subsurface rock behaviour al 300 m depth and 800 m depth respectively, beginning at peripheral places and ending at the central part or selected site. Basic purposes of boreholes were to define structural and petrographic features of the rock massif by a good comprehension of master joints and faulting distribution with its belts of alteration mylonitization or brecciation, mechanical properties of samples, chemical composition and varitions, petrographic facies and mineralogy. Boreholes provided data to investigate joints, faults and dikes as general discontinuities for hydraulic research like permeability or effective hydraulic conductivity, and their geostatistical modelling. Boreholes are also being prepared for geophysical logging from which logthermal ones have already been completed. (Author)

  14. Seed germination of Sierra Nevada postfire chaparral species

    Science.gov (United States)

    Keeley, Jon E.; McGinnis, Thomas W.; Bollens, Kim A.

    2005-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Here we report further germination experiments that elucidate the response of several widespread shrub species whose germination response was not clear and include other species from the Sierra Nevada, which have not previously been included in germination studies. The shrubs Adenostoma fasciculatum and Eriodictyon crassifolium and the postfire annualMentzelia dispersa exhibited highly significant germination in response to smoke treatments, with some enhanced germination in response to heating as well. The shrubs Fremontodendron californicum and Malacothamnus fremontii were stimulated only by heat-shock treatments. Seeds buried in the soil for one year exhibited substantially higher germination for controls and most treatments. In the case of two postfire annuals, Mimulus bolanderi and M. gracilipes, germination of fresh seed was significantly greater with smoke or heating but after soil storage, over two-thirds of the control seeds germinated and treatment effects were not significant. These two annuals are generally restricted to postfire conditions and it is suggested that control germination of soil-stored seed may be a light-response (which was not tested here) as previously reported for another chaparral species in that genus.

  15. Farming Families' Access to Water in the Pampa Region: A multidimensional analysis El acceso al agua de los agricultores familiares de la región pampeana: Un análisis multidimensional

    Directory of Open Access Journals (Sweden)

    Alejandra Moreyra

    2012-01-01

    Full Text Available This paper presents the conceptual and methodological perspective of participatory action research with an interdisciplinary approach. Specifically, this research examines different dimensions that condition the access to water for farming families in the Pampa region. Together with famers and extension workers, we defined the problems, considering that water as mediator of social relations among different actors involved - resource appropriation for irrigation and agricultural production and other sectors' productions, family consumption and sewage-. In the last sections of the document, the research team presents observations, analysis and reflections on the progress of field work we have done so farEste artículo presenta, en su primera parte, el enfoque conceptual y metodológico de un proyecto de investigación-acción participativa abordado de forma interdisciplinaria. La investigación refiere a las diferentes dimensiones que condicionan el acceso al agua de los agricultores familiares en distintos sitios de la región pampeana. La problemática se define en la dinámica con los actores involucrados, considerando que el agua mediatiza las relaciones sociales -de apropiación para el riego y la producción agrícola y de otros sectores, el consumo y la eliminación de residuos- entre diferentes actores. En las últimas secciones se presentan algunas de las observaciones y reflexiones del equipo de investigación en base a los primeros avances del trabajo de campo

  16. Comparación de índices de estrés hídrico, a partir de información captada por el sensor MODIS, en la región pampeana argentina

    Directory of Open Access Journals (Sweden)

    Patricia Vazquez

    2013-01-01

    Full Text Available La Región Pampeana Argentina manifiesta una tenencia a la expansión agrícola que aumenta los riesgos económicos por su elevada dependencia de las condiciones meteorológicas. A fin de mejorar las predicciones sobre el comportamiento de los cultivos, en este trabajo se estudia la sensibilidad de diferentes índices de estrés hídrico a la disponibilidad de agua en el suelo (DAS, mediante el uso de imágenes satelitales en la mencionada región. Se analizaron tres índices a partir de datos de campañas de terreno en diferentes cultivos, conjuntamente con información satelital. Dos de ellos, Crop Water Stress Index (CWSI y Water Deficit Index (WDI, combinan información de satélite con datos de estaciones meteorológicas. El tercero, Temperature–Vegeta- tion Dryness Index (TDVI, utiliza solamente información de satélite. Se observó que el TDVI es el que mejor resultados arroja (r2 = 0,92. Se concluye que este índice es el que permite generar diagnósticos adecuados por ser el más sensible a cambios en la DAS.

  17. Eficiencia agronómica del azufre elemental relativa a una fuente azufrada soluble en trigo en la Región Pampeana Agronomic efficiency of elemental sulphur in wheat relative to a soluble sulphur source in the Pampas Region

    Directory of Open Access Journals (Sweden)

    Martin Torres Duggan

    2010-07-01

    Full Text Available La eficiencia agronómica del azufre elemental (AE en relación a fuentes azufradas solubles y sulfatadas, depende de su reactividad (e.g. tamaño de partícula y de las condiciones edafo-climáticas. Para las condiciones de la Región Pampeana algunas publicaciones sugieren que el AE puede ser una fuente de S tan efectiva como las fuentes solubles, aunque la información no concluyente. Se hipotetiza que en las condiciones de la Región Pampeana, ambas fuentes poseen similar eficiencia agronómica en la mayoría de los años. Los objetivos del trabajo fueron: i. Evaluar la respuesta al agregado de S con una fuente reactiva de AE en relación a un fertilizante azufrado sulfatado, aplicado en trigo en diferentes dosis y en distintas condiciones edafo-climáticas; ii. Comparar, para el conjunto de experimentos, la eficiencia agronómica del S aplicado con las distintas fuentes. iii. Relacionar las respuestas a la fertilización azufrada con variables de suelo y clima. Se realizaron ocho ensayos de campo durante dos años consecutivos en lotes de producción ubicados en la Región Pampeana. Se aplicó un diseño en bloques completos aleatorizados con cuatro o seis repeticiones en un arreglo factorial de tratamientos (factor 1: fuente azufrada, factor 2: dosis de S. Los tratamientos fueron: un testigo absoluto; fertilización con AE micronizado (95% de S en dos niveles de dosis y fertilización con sulfato de amonio granulado (SA, 24% S, también en dos niveles de dosis. Las dosis evaluadas fueron 10 y 30 kg ha-1 de S (año 1 y 15 y 30 kg ha¹ (año 2. La fertilización azufrada afectó significativamente (p0,05 en la mayoría de los sitios. La dosis más baja (10 o 15 kg ha-1 fue suficiente para cubrir el requerimiento de S del cultivo. Se observó una asociación positiva entre las respuestas y el contenido de MO del suelo y las precipitaciones (macollaje y total del ciclo y una relación inversa con el contenido de S-SO4(2- disponibles a la

  18. Impacts of snow water equivalent on forest disturbance in the Sierra Nevada with climate change

    Science.gov (United States)

    Nguyen, A.; Mueller, C.; Petrakis, R.; Adkins, S.; Kuss, O.; Kumaran, M.; Meyer, M.; Schmidt, C.

    2013-12-01

    High Sierra snow and ice provide the primary water supply for the Sierra Nevada ecosystem. Understanding how climate change affects high Sierra snowmelt and how these changes impact forest disturbance is important for future forest management. Snow water equivalent (SWE) anomalies were averaged on a monthly basis and overall trends of snowpack availability and timing of snowmelt were examined throughout the Sierra Nevada from 2003 - 2012. Periods of decreased snowpack were examined alongside periods of decreased soil moisture, increased soil temperature, and increased wild fires. This project used NASA Earth Observations (EOS) such as the Moderate Resolution Imaging Spectroradiometer (MODIS) for snow cover and Landsat 5 for extent of forest disturbance and vegetative analysis. We also used ancillary and modeled datasets such as temperature, precipitation, and water flow rate to provide a better understanding of the relation between snowpack, soil moisture availability, and soil temperature to wildfires. A Generalized Additive Model (GAM) was used to make predictions of future forest disturbance patterns as well to analyze the sensitivity of particular variables indicative of wildfire. This information is useful for forest management decisions within the US Forest Service and will assist in the incorporation of climate change impact assessments on forest health. Layers of various climatic and surface conditions along with areas of fire are used in the Generalize Additive Model to create a wildfire risk map of the Sierra Nevada M261E Ecological Region, CA.

  19. Sierra/SolidMechanics 4.22 user's guide : addendum for shock capabilities.

    Energy Technology Data Exchange (ETDEWEB)

    2011-10-01

    This is an addendum to the Sierra/SolidMechanics 4.22 User's Guide to document additional capabilities that are available for use in the Presto{_}ITAR code that are not available for use in the standard version of Sierra/SolidMechanics (Sierra/SM). Presto{_}ITAR is an enhanced version of Sierra/SM that provides capabilities that make it regulated under the U.S. Department of State's International Traffic in Arms Regulations (ITAR) export-control rules. This code is part of the Vivace product, and is only distributed to entities that comply with ITAR regulations. The enhancements primarily focus on material models that include an energy-dependent pressure response, appropriate for very large deformations and strain rates. Since this is an addendum to the standard Sierra/SolidMechanics User's Guide, please refer to that document first for general descriptions of code capability and use. This addendum documents material models and element features that support energy-dependent material models.

  20. Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain

    Directory of Open Access Journals (Sweden)

    Antonio Jesús Pérez-Luque

    2014-02-01

    Full Text Available The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain. The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic inventory was created to gather useful information for the proper management of Pinus plantations in Sierra Nevada. This is the only dataset that shows a comprehensive view of the forest flora in Sierra Nevada. This is the reason why it is being used to assess the biodiversity in the very dense pine plantations on this massif. With this dataset, managers have improved their ability to decide where to apply forest treatments in order to avoid biodiversity loss. The dataset forms part of the Sierra Nevada Global Change Observatory (OBSNEV, a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

  1. 78 FR 72926 - Bald and Golden Eagles; Migratory Birds; Phase I Development of the Chokecherry-Sierra Madre Wind...

    Science.gov (United States)

    2013-12-04

    ...), announce our intent to prepare a draft Environmental Impact Statement (EIS) for Phase I of the Chokecherry-Sierra Madre Wind Energy Project. Our draft EIS will analyze the environmental impacts associated with... Chokecherry-Sierra Madre Wind Energy Project AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice...

  2. Airborne Pesticides as an Unlikely Cause for Population Declines of Alpine Frogs in the Sierra Nevada, California

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured...

  3. 77 FR 45 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List Sierra Nevada...

    Science.gov (United States)

    2012-01-03

    ... in the Petition The petition asserts that exposure of Sierra Nevada red fox to domestic dogs places... dogs have been documented in other subspecies of red fox, and can be fatal (Little et al. 1998, p. 623... individuals, attributing the death of one directly to a dog attack. Given that the Sierra Nevada red...

  4. Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

    Science.gov (United States)

    Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

    2016-01-01

    Abstract In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:26865820

  5. Origen y decadencia del gamonalismo en la sierra ecuatoriana

    Directory of Open Access Journals (Sweden)

    Ibarra Crespo, Hernán

    2002-12-01

    Full Text Available This article analyzes the historical path of gamonalismo in Ecuadorian highlands. Although it could be alike to Mexican caciquismo and Brazilian coronelismo, gamonalismo had its specific forms. In Ecuador it is possible to reconstruct its meaning in political terms, as a form of traditional domination. The use of this particular term is analyzed in different historical moments between the 18th and 20th century; focusing on the origin and decline of this local power. The aim is to build an interpretative frame in order to understand agrarian sources of Ecuadorian state development and ethnic domination.

    Este artículo analiza la trayectoria histórica del gamonalismo en la sierra ecuatoriana. Aunque homologado con el caciquismo mexicano y el coronelismo brasileño, tiene rasgos específicos. En el Ecuador es posible reconstruir el significado del gamonalismo en el lenguaje político y como modalidad de dominación tradicional. Por una parte, se realiza un rastreo y análisis del uso del término en distintos momentos históricos entre los siglos XVIII y XX. Por otra parte, se efectúa un abordaje del origen y declinación de esta forma de poder. Se aspira a construir un marco interpretativo que aporte a la comprensión de los fundamentos agrarios de la constitución del Estado ecuatoriano y las formas de dominación étnica.

  6. Social indicators of dental caries among Sierra Leonean schoolchildren.

    Science.gov (United States)

    Nörmark, S

    1993-06-01

    Most of the caries of African child populations is found in limited fractions of that population. The purpose of the present study was to analyze the caries situation of Sierra Leonean schoolchildren in relation to demographic, socioeconomic, and behavioral variables, in order to develop an appropriate index for prediction of caries. A total of 610 students from primary class 1 (mean age: 7 yr) and secondary form 1 (mean age 15 yr) were dentally examined by three examiners and interviewed by their teachers. Intra- and interexaminer reproducibilities were 82 and 70%, and interinterviewer reliability was 67-100% for the individual questions. Urban students had more caries than rural. In class 1, dmfs+DMFS was 4.1 and 1.8, respectively; in form 1, DMFS was 5.3 and 3.5. Two tribes (the Fulas and the Madingos) had higher caries means than the rest, especially in class 1, where dmfs+DMFS was 6.5 and 2.4, respectively. Form 1 students with literate parents had a higher caries mean, and class 1 pupils with defective school uniforms a lower mean. The apparently high-risk groups did not consume more sweet snacks or clean their teeth less frequently. There was clearly more caries among the quartiles of children with most visible plaque on molars, but all social and demographic subgroups had similar amounts of plaque. Multivariate analyses of class 1 children showed that pupils living in urban areas, Fulas and Madingos, and children wearing complete school uniforms had caries significantly more frequently, other factors being equal.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8322004

  7. Vulnerability of birds to climate change in California's Sierra Nevada

    Directory of Open Access Journals (Sweden)

    Rodney B. Siegel

    2014-06-01

    Full Text Available In a rapidly changing climate, effective bird conservation requires not only reliable information about the current vulnerability of species of conservation concern, but also credible projections of their future vulnerability. Such projections may enable managers to preempt or reduce emerging climate-related threats through appropriate habitat management. We used NatureServe's Climate Change Vulnerability Index (CCVI to predict vulnerability to climate change of 168 bird species that breed in the Sierra Nevada mountains of California, USA. The CCVI assesses species-specific exposure and sensitivity to climate change within a defined geographic area, through the integration of (a species' range maps, (b information about species' natural history traits and ecological relationships, (c historic and current climate data, and (d spatially explicit climate change projections. We conducted the assessment under two different downscaled climate models with divergent projections about future precipitation through the middle of the 21st century. Assessments differed relatively little under the two climate models. Of five CCVI vulnerability ranking categories, only one species, White-tailed Ptarmigan (Lagopus leucura, received the most vulnerable rank, Extremely Vulnerable. No species received the second-highest vulnerability ranking, Highly Vulnerable. Sixteen species scored as Moderately Vulnerable using one or both climate models: Common Merganser (Mergus merganser, Osprey (Pandion haliaetus, Bald Eagle (Haliaeetus leucocephalus, Northern Goshawk (Accipiter gentilis, Peregrine Falcon (Falco peregrinus, Prairie Falcon (Falco mexicanus, Spotted Sandpiper (Actitis macularius, Great Gray Owl (Strix nebulosa, Black Swift (Cypseloides niger, Clark's Nutcracker (Nucifraga columbiana, American Dipper (Cinclus mexicanus, Swainson's Thrush (Catharus ustulatus, American Pipit (Anthus rubescens, Gray-crowned Rosy-Finch (Leucosticte tephrocotis, Pine Grosbeak

  8. Dosis óptima económica de nitrógeno en maíz según potencial de producción y disponibilidad de nitrógeno en la región pampeana norte Economic optimal nitrogen rate as affected by yield potential and nitrogen supply in the northern pampas

    OpenAIRE

    Fernando Salvagiotti; Julio Manuel Castellarín; Facundo Javier Ferraguti; Hugo Miguel Pedrol

    2011-01-01

    El maíz es el principal cereal de verano en la Región Pampeana norte de la Argentina donde los suelos presentan una deficiencia crónica de nitrógeno (N). La fertilización nitrogenada en maíz debe optimizar los niveles de N disponible a la siembra (Nds=Nds inic + N fertilizante) para asegurar la máxima rentabilidad y evitar altas dosis que perjudiquen el ambiente. Los objetivos de este trabajo fueron: i) comparar la capacidad de los modelos cuadrático-plateau (CP) y esférico (Esf) para estimar...

  9. Snow algae of the Sierra Nevada, Spain, and High Atlas mountains of Morocco.

    Science.gov (United States)

    Duval, B; Duval, E; Hoham, R W

    1999-03-01

    Snow algae (Chlorophyta) are reported from the Sierra Nevada mountains in southern Spain and the High Atlas mountains of Morocco. Populations of the snow algae Chlamydomonas sp., coloring the snow orange-red, were collected from Pico de Veleta, Spain, while snow samples from Mt. Neltner in the High Atlas mountains, contained resting spores of an orange-green colored Chloromonas sp. Other microbes observed in snow samples include bacteria, fungi, heterotrophic euglenids, diatoms, nematodes, and heterotrophic mastigotes (flagellated protists). This is the first report of snow algae from the Sierra Nevada mountains of Spain and from the Afro-alpine environment. PMID:10943390

  10. La dinámica demográfica reciente en la Sierra Morena Cordobesa

    OpenAIRE

    Ricardo Manuel Luque Revuelto

    2012-01-01

    RESUMEN: La Sierra de Córdoba constituye un ámbito espacial diferenciado en la provincia y en el conjunto de Andalucía. Los habitantes de los espacios mariánicos son el elemento básico en la ocupación de ese territorio, caracterizado por un marcado carácter rural. El estudio de la dinámica demográfica reciente de los espacios mariánicos y las diferencias regionales que presenta constituye el objetivo principal del presente trabajo. ABSTRACT: The Sierra de Cordoba is a distinct spatial are...

  11. Media and conflict in Sierra Leone: national and international perspectives of the civil war

    OpenAIRE

    Valentina Bau

    2011-01-01

    The rise of the media in Sierra Leone. The media and the civil conflict. The evolution of the conflict. The Western media perspective of a "barbaric" Africa. Western media coverage of the civil war in Sierra Leone: the British example. The role of NGOs in news reporting.

    The end of the twentieth century saw an adverse escalation in armed conflict. A characteristic of this was that whilst the majority of wars that took place before the 1990s were fought between state...

  12. Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Mar ta, Colombia

    International Nuclear Information System (INIS)

    Two research stations (M inca, 700 m altitude and Maria Ter esa, 790 m altitude) were established in the Sierra Nevada de Santa Mar ta in places to study the soil fauna associated with forest and coffee plantations. Soil fauna was collected using pitfall and Bailer's traps. Samples were taken from litter as well as from horizons 0, A and B. individuals collected were identified to family level. Diversity, abundance and frequency indexes were used to compare fauna composition at both sites. Significant differences were found between the two research sites as well as with data from other high altitude forest in the Sierra Nevada de Santa Mar ta

  13. Señales del cambio global en el sitio LTER-Sierra Nevada

    OpenAIRE

    A.J. Pérez-Luque; F.J. Bonet; Zamora, R.; J.M. Barea-Azcón; R. Aspizua; F.J. Sánchez-Gutiérrez

    2016-01-01

    La investigación ecológica a largo plazo proporciona información útil para comprender las complejas dinámicas de los sistemas naturales. Esto se hace especialmente importante en las regiones de montaña como Sierra Nevada, que presenta un fuerte gradiente de condiciones ambientales en una escala espacial pequeña. En el sitio LTER-Sierra Nevada se ha implementado un programa de seguimiento a largo plazo que, junto con la integración de información ecológica sobre los ecosistemas nevadenses, est...

  14. Numerical Wind Modeling for the San Pedro Mártir Sierra in Baja California

    Directory of Open Access Journals (Sweden)

    K. Vogiatzis

    2004-01-01

    Full Text Available Presentamos la simulación numérica del viento en la Sierra de San Pedro Mártir para realizar una evaluación preliminar de los posibles sitios donde instalar nuevos telescopios. Como criterio inicial, se eligieron los puntos más altos de la sierra, pero a la vez de fácil acceso. Se presentan la altura de la capa límite y el efecto de la turbulencia en los diferentes sitios para velocidades y direcciones del viento típicas.

  15. Noteworthy records of two species of mammals in the Sierra Madre de Oaxaca, Mexico Registros notables de dos especies de mamíferos de la Sierra Madre de Oaxaca, México

    Directory of Open Access Journals (Sweden)

    Miguel Briones-Salas

    2006-12-01

    Full Text Available We conducted mammal surveys in the Sierra Madre de Oaxaca (Sierra Norte in Oaxaca, Mexico, and recorded the occurrence of two conspicuous mammal species: the spider monkey (Ateles geoffroyi vellerosus and the coyote (Canis latrans cagottis. Spider monkeys has not been previously recorded in the Sierra Madre de Oaxaca, and coyotes have not been previously observed in Mexico at elevations as high as the present one (3 200 mas1 in the Sierra Madre de Oaxaca.Se efectuaron colectas de mamíferos en la Sierra Madre de Oaxaca (Sierra Norte en Oaxaca, México, y se registró la notoria presencia de dos mamíferos: el mono araña (Ateles geoffroyi vellerosus y el coyote (Canis latrans cagottis. El mono araña no se había registrado previamente en la Sierra Madre de Oaxaca, en tanto que el coyote, no había sido registrado en México a tan gran altitud (3 200 m como la de la localidad de captura.

  16. Metodología de análisis de hipoplasias del esmalte dental aplicada al estudio de poblaciones prehispánicas del sudeste de la Región Pampeana

    Directory of Open Access Journals (Sweden)

    Barrientos, Gustavo

    1999-01-01

    Full Text Available El objetivo de este trabajo es presentar la metodología de análisis de hipoplasias del esmalte dental aplicada al estudio de una muestra de esqueletos humanos provenientes de diversos sitios arqueológicos del Sudeste de la Región Pampeana, asignables a distintos momentos del Holoceno. Para cada diente, se realizó una evaluación del grado de sensibilidad para el registro de hipoplasias y del grado de representatividad a nivel muestral. Debido a que los dientes con mayor frecuencia relativa de hipoplasias fueron, al mismo tiempo, los de más baja representación en la muestra (i.e. C1, se analizaron todas las clases de dientes presentes. Se calcularon prevalencias por sexo, edad y período. Se introdujo una nueva medida de la experiencia individual de stress, denominada Número Mínimo de Eventos de Detención del Crecimiento Dental (NMEDCD. La edad etiológica de las líneas de hipoplasia sólo fue calculada en el C1, empleando los datos longitudinales proporcionados por Dean et al. (1993. No se encontraron diferencias estadisticamente significativas entre los porcentajes de prevalencia correspondientes a cada período, ni entre los correspondientes a las distintas categorías de sexo y edad. Las edades etiológicas medias de las submuestras discriminadas por período tampoco mostraron diferencias significativas. Los datos disponibles para esta muestra acerca de los procesos de atrición y desgaste, indican que hasta los 40 años, límite de edad que incluye aproximadamente el 75% de la muestra total analizada, los efectos de tales procesos probablemente influyeron en forma mínima sobre la preservación y las posibilidades de registro y análisis de las hipoplasias.

  17. The effects of epilepsy on child education in Sierra Leone.

    Science.gov (United States)

    Ali, Desta B; Tomek, Michal; Lisk, Durodami R

    2014-08-01

    Epilepsy is associated with a significant burden of false beliefs and social stigma in the setting of Sub-Saharan Africa. To assess the impacts of epilepsy on child education in Sierra Leone (SL), we carried out a cross-sectional descriptive study examining its effects on school attendance, participation in physical activities, and social acceptance among classmates. We also assessed the knowledge, beliefs, and attitudes regarding epilepsy of both the children's caregivers and teachers. The data were collected at various epilepsy clinics and schools in Freetown, SL. A total of 50 patients were interviewed and questionnaires administered to their caregivers and teachers, making a total of 150 respondents. Fifty-one percent of the children were absent from school for >5 days per month. Ninety percent did not participate in games and sports, with the commonest reason being fear of occurrence of seizures. Thirty-six percent claimed having experienced negative attitude from their classmates. Regarding the caregivers, 48% believed that epilepsy was a medical illness, while 34% considered it a demonic manifestation. Forty-eight percent were apprehensive about sending their children to school, with 83% of these caregivers stating fear of seizures and potential injuries. Only 8% of the caregivers did not prevent their children from taking part in any physical activity at school. Regarding the teachers, 16% believed that epilepsy was a demonic manifestation, and 10% thought that it was contagious. Fourteen percent did not think that children with epilepsy should go to school, and 80% would prevent children with epilepsy from participating in games and sports. When faced with a child having a seizure, 48% would hold the child down, 12% would place a hard object in the child's mouth, and 12% would avoid any physical contact. In total, 20% of the children ceased attending school permanently; daily occurrence of seizures (p<0.05), negative attitude of classmates (p<0.001), and

  18. Socio-Ecological Factors Affecting Pregnant Women's Anemia Status in Freetown, Sierra Leone

    Science.gov (United States)

    M'Cormack, Fredanna; Drolet, Judy

    2012-01-01

    Background: Sierra Leone has high maternal mortality. Socio-ecological factors are considered contributing factors to this high mortality. Anemia is considered to be a direct cause of 4% of maternal deaths and an indirect cause of 20-40% of maternal deaths. Purpose: The current study explores socio-ecological contributing factors to the anemia…

  19. Early Phanerozoic trace fossils from the Sierra Albarrana quartzites (Ossa-Morena Zone, Southwest Spain)

    NARCIS (Netherlands)

    Marcos, A.; Azor, A.; González, F.; Simancas, F.

    1991-01-01

    Three ichnogenera are described from a 50 to 500 m thick shallow-water sandstone-shale sequence (Sierra Albarrana Quartzites). The ichnofauna consists of the burrows of worm-like animals (Arenicolites, Monocraterion, and Skolithos). The age of this formation, previously considered to be Precambrian

  20. A Miocene to Pleistocene climate and elevation record of the Sierra Nevada (California).

    Science.gov (United States)

    Mulch, A; Sarna-Wojcicki, A M; Perkins, M E; Chamberlain, C P

    2008-05-13

    Orographic precipitation of Pacific-sourced moisture creates a rain shadow across the central part of the Sierra Nevada (California) that contrasts with the southern part of the range, where seasonal monsoonal precipitation sourced to the south obscures this rain shadow effect. Orographic rainout systematically lowers the hydrogen isotope composition of precipitation (deltaD(ppt)) and therefore deltaD(ppt) reflects a measure of the magnitude of the rain shadow. Hydrogen isotope compositions of volcanic glass (deltaD(glass)) hydrated at the earth's surface provide a unique opportunity to track the elevation and precipitation history of the Sierra Nevada and adjacent Basin and Range Province. Analysis of 67 well dated volcanic glass samples from widespread volcanic ash-fall deposits located from the Pacific coast to the Basin and Range Province demonstrates that between 0.6 and 12.1 Ma the hydrogen isotope compositions of meteoric water displayed a large (>40 per thousand) decrease from the windward to the leeward side of the central Sierra Nevada, consistent with the existence of a rain shadow of modern magnitude over that time. Evidence for a Miocene-to-recent rain shadow of constant magnitude and systematic changes in the longitudinal climate and precipitation patterns strongly suggest that the modern first-order topographic elements of the Sierra Nevada characterized the landscape over at least the last 12 million years. PMID:18441101

  1. Multinationals and employment in a West African sub-region: Liberia and Sierra Leone.

    OpenAIRE

    Iyanda O

    1983-01-01

    ILO pub. Working paper on the impact of multinational enterprises on employment in West Africa, comprising a case study of Liberia and Sierra Leone - discusses direct foreign investment trends (1970-1981), sectoral distribution, investment policies relating to agricultural sector and mining as well as manufacturing; the impact on employment creation, productivity, wages, training, public finance, etc., (incl. Linkage effects). References.

  2. Who cares for former child soldiers? Mental health systems of care in Sierra Leone

    NARCIS (Netherlands)

    S. Song; H. van den Brink; J. de Jong

    2013-01-01

    While numerous studies on former child soldiers (FCS) have shown mental health needs, adequate services are a challenge. This study aimed to identify priorities, barriers and facilitators of mental health care for Sierra Leonean FCS. Thematic analysis was done on 24 qualitative interviews with parti

  3. Sierra Leone's Former Child Soldiers: A Longitudinal Study of Risk, Protective Factors, and Mental Health

    Science.gov (United States)

    Betancourt, Theresa S.; Brennan, Robert T.; Rubin-Smith, Julia; Fitzmaurice, Garrett M.; Gilman, Stephen E.

    2010-01-01

    Objective: To investigate the longitudinal course of internalizing and externalizing problems and adaptive/prosocial behaviors among Sierra Leonean former child soldiers and whether postconflict factors contribute to adverse or resilient mental health outcomes. Method: Male and female former child soldiers (N = 260, aged 10 to 17 years at…

  4. Sierra Leone's Former Child Soldiers: A Follow-Up Study of Psychosocial Adjustment and Community Reintegration

    Science.gov (United States)

    Betancourt, Theresa Stichick; Borisova, Ivelina Ivanova; Williams, Timothy Philip; Brennan, Robert T.; Whitfield, Theodore H.; de la Soudiere, Marie; Williamson, John; Gilman, Stephen E.

    2010-01-01

    This is the first prospective study to investigate psychosocial adjustment in male and female former child soldiers (ages 10-18; n = 156, 12% female). The study began in Sierra Leone in 2002 and was designed to examine both risk and protective factors in psychosocial adjustment. Over the 2-year period of follow-up, youth who had wounded or killed…

  5. 78 FR 24471 - Endangered and Threatened Wildlife and Plants; Endangered Status for the Sierra Nevada Yellow...

    Science.gov (United States)

    2013-04-25

    ... History Mountain yellow-legged frogs currently exist in montane regions of the Sierra Nevada of California... by mountain yellow-legged frogs are frequently grassy or muddy. This differs from the sandy or rocky... Northern Distinct Population Segment of the Mountain Yellow-Legged Frog, and Threatened Status for...

  6. Sierra Leone : Public Expenditure Review for Water and Sanitation 2002 to 2009

    OpenAIRE

    Bennett, Anthony; Thompson, Darrell; Ginneken, Meike van

    2011-01-01

    This review focuses on how public expenditure translates into the delivery of water supply and sanitation services in rural and urban areas in Sierra Leone. It describes the legal and institutional framework for the allocation of resources assesses access to Water Supply and Sanitation (WSS) services and past sector performance, and analyzes public expenditure in the sector, including the ...

  7. Improved Present Day Euler Vector for the Sierra Nevada Block Using GPS

    Science.gov (United States)

    Psencik, K. O.; Dixon, T. H.; Schmalzle, G.; McQuarrie, N.; McCaffery, R.

    2006-12-01

    We present a new surface velocity field for California and Nevada (UM-CANVAS) and use it to solve for a new angular velocity for the rigid Sierra Nevada-Great Valley block. We use all publicly available GPS data for this region, from both continuous (CGPS) and episodic campaign (EGPS) sites. All data were re-processed to create a consistent velocity field. Site velocities are referenced to both stable North America and the central Basin and Range. The Sierra Nevada block is a relatively long, narrow block, bounded on the west by the San Andreas Fault, on the east by a complex fault system comprising the Eastern California Shear Zone and the Walker Lane Belt, and on the south by the Garlock fault. The northern extent of the block is not well defined. The new data along with a strain accumulation algorithm may help to define this boundary. Published estimates for the motion of Sierra Nevada block include clockwise, counter-clockwise, and no rotation relative to stable North America; the new velocity data may also help to resolve this discrepancy. To better understand the motion of the Sierra Nevada block over time, we compare our model of present day motion to a geologic model of block motion over the last 2-3 Ma (McQuarrie and Wernicke, 2005). McQuarrie, N. and B. Wernicke, An Animated tectonic reconstruction of southwestern North America since 36 Ma. Geosphere, V.1; no.3; 147-172; 2005.

  8. Decentralization, Accountability and Local Services in Sierra Leone : Situation Analysis, Key Challenges and Opportunities for Reform

    OpenAIRE

    World Bank

    2014-01-01

    Following years of civil war that ended in 2002, Sierra Leone has pursued a policy of decentralization, devolving responsibility for many government functions to the Local Council level. The aims of this policy include achieving a more equitable and inclusive access to public services across the national territory, in part to alleviate regional inequities that contributed to the civil war....

  9. Die Geologie von Camarena de la Sierra und Riodeva (Provinz Teruel, Spanien)

    NARCIS (Netherlands)

    Wz., R. Martin

    1936-01-01

    Als ich im Jahre 1933 ein Gebiet für meine Feldarbeit suchte, wählte ich auf Veranlassung von Herrn Dr. I. M. van der Vlerk die Gemeinde Camarena de la Sierra südlich von Teruel, wo G. R. J. Terpstra, damals Student der Geologie zu Leiden, im Sommer 1931 eine geologische Aufnahme angefangen hatte, w

  10. Aircraft measurements of the impacts of pollution aerosols on clouds and precipitation over the Sierra Nevada

    Science.gov (United States)

    Rosenfeld, Daniel; Woodley, William L.; Axisa, Duncan; Freud, Eyal; Hudson, James G.; Givati, Amir

    2008-08-01

    Recent publications suggest that anthropogenic aerosols suppress orographic precipitation in California and elsewhere. A field campaign (SUPRECIP: Suppression of Precipitation) was conducted to investigate this hypothesized aerosol effect. The campaign consisted of in situ aircraft measurements of the polluting aerosols, the composition of the clouds ingesting them, and the way the precipitation-forming processes are affected. SUPRECIP was conducted during February and March of 2005 and February and March of 2006. The flights documented the aerosols and orographic clouds flowing into the central Sierra Nevada from the upwind densely populated industrialized/urbanized areas and contrasted them with the aerosols and clouds downwind of the sparsely populated areas in the northern Sierra Nevada. SUPRECIP found that the aerosols transported from the coastal regions are augmented greatly by local sources in the Central Valley resulting in high concentrations of aerosols in the eastern parts of the Central Valley and the Sierra foothills. This pattern is consistent with the detected patterns of suppressed orographic precipitation, occurring primarily in the southern and central Sierra Nevada, but not in the north. The precipitation suppression occurs mainly in the orographic clouds that are triggered from the boundary layer over the foothills and propagate over the mountains. The elevated orographic clouds that form at the crest are minimally affected. The clouds are affected mainly during the second half of the day and the subsequent evening, when solar heating mixes the boundary layer up to cloud bases. Local, yet unidentified nonurban sources are suspected to play a major role.

  11. Bodies in action. Culture and body skills in post-conflict Sierra Leone

    NARCIS (Netherlands)

    Niet, van der A.

    2010-01-01

    This book is about human body movement and culture. The body skills of a sample of Sierra Leoneans are analyzed in terms of acquisition of the skills, the importance of learning these skills to become part of a community and the physical consequences of the activities. It focuses on skills in footba

  12. Pesticide Distributions and Population Declines of California Alpine Frogs, Rana Muscosa and Rana Sierrae

    Science.gov (United States)

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in th...

  13. Educating Africans for Inferiority under British Rule: Bo School in Sierra Leone.

    Science.gov (United States)

    Corby, Richard A.

    1990-01-01

    Sierra Leone's Bo School was established in 1906 by British colonial officials to educate chiefs' sons for subordinate positions. Nevertheless, the school contributed to creation of the postindependence ruling class. Enrollment, curriculum, student life, responsibilities of British and African teachers, and alumni networks are examined. Contains…

  14. Señales del cambio global en el sitio LTER-Sierra Nevada

    Directory of Open Access Journals (Sweden)

    A.J. Pérez-Luque

    2016-01-01

    Full Text Available La investigación ecológica a largo plazo proporciona información útil para comprender las complejas dinámicas de los sistemas naturales. Esto se hace especialmente importante en las regiones de montaña como Sierra Nevada, que presenta un fuerte gradiente de condiciones ambientales en una escala espacial pequeña. En el sitio LTER-Sierra Nevada se ha implementado un programa de seguimiento a largo plazo que, junto con la integración de información ecológica sobre los ecosistemas nevadenses, está permitiendo evaluar los efectos del cambio global en esta región de montaña. En este trabajo presentamos algunos resultados de los impactos del cambio global sobre los ecosistemas nevadenses, obtenidos tras varios años de implantación del Observatorio del Cambio Global de Sierra Nevada. Además de una evaluación temporal de los principales motores de cambio global (clima y usos del suelo, presentamos varios casos de estudio del impacto del cambio global sobre la componente biótica y socioeconómica de los ecosistemas de Sierra Nevada.

  15. Hacia una Estrategia de Desarrollo para la Sierra Rural en el Perú

    NARCIS (Netherlands)

    Escobal, J.A.; Valdivia, L.

    2004-01-01

    El objetivo de este proyecto es elaborar un documento que establezca los lineamientos de una política de desarrollo para la Sierra rural en el Perú e identificar los requerimientos institucionales y de investigación complementaria que se requerirían para la construcción de programas específicos que

  16. School Persistence in the Wake of War: Wartime Experiences, Reintegration Supports, and Dropout in Sierra Leone

    Science.gov (United States)

    Zuilkowski, Stephanie Simmons; Betancourt, Theresa S.

    2014-01-01

    This article examines the relationship of wartime experience and reintegration supports to students' risk of school dropout. It draws on longitudinal, mixed-methods data collected among children and youth in Sierra Leone from 2002 through 2008. The study finds that family financial support and perceived social support are positively…

  17. Coming back from the bush : gender, youth and reintegration in northern Sierra Leone

    NARCIS (Netherlands)

    Gog, van J.G.

    2008-01-01

    This thesis explores the postwar reintegration strategies of young women who had forcibly become affiliated with one of the fighting factions during the ten years of civil war in Sierra Leone. Instead of conceptualizing reintegration as the result of policies, the author defines it as the dynamic pr

  18. 75 FR 44942 - 2015 Resource Pool-Sierra Nevada Customer Service Region

    Science.gov (United States)

    2010-07-30

    ...: Background Pursuant to the Marketing Plan (64 FR 34417, June 25, 1999), Western published the Call for 2015... (DOE), published its 2004 Power Marketing Plan (Marketing Plan) for the Sierra Nevada Customer Service Region (SNR) in the Federal Register on June 25, 1999. The Marketing Plan specifies the terms...

  19. Ebola Virus Disease Complications as Experienced by Survivors in Sierra Leone

    OpenAIRE

    Tiffany, Amanda; Vetter, Pauline; Mattia, John; Dayer, Julie-Anne; Bartsch, Maria; Kasztura, Miriam Sophie; Sterk, Esther; Tijerino, Ana Maria; Kaiser, Laurent; Ciglenecki, Iza

    2016-01-01

    Thousands of people have survived Ebola virus disease (EVD) during the ongoing outbreak. However, data about the frequency and risk factors of long-term post-EVD complications remain scarce. We describe the clinical characteristics of EVD survivors followed in a survivor clinic in Freetown, Sierra Leone.

  20. Genotypic anomaly in ebola virus strains circulating in magazine wharf Area, Freetown, Sierra Leone, 2015

    NARCIS (Netherlands)

    S.L. Smits (Saskia); S.D. Pas (Suzan); C.B.E.M. Reusken (Chantal); B.L. Haagmans (Bart); P. Pertile; C. Cancedda; K. Dierberg; I. Wurie; A. Kamara; D. Kargbo; S.L. Caddy; A. Arias; L. Thorne; J. Lu; U. Jah; I. Goodfellow; M.P.G. Koopmans D.V.M. (Marion)

    2015-01-01

    textabstractThe Magazine Wharf area, Freetown, Sierra Leone was a focus of ongoing Ebola virus transmission from late June 2015. Viral genomes linked to this area contain a series of 13 T to C substitutions in a 150 base pair intergenic region downstream of viral protein 40 open reading frame, simil

  1. Training for Innovation: Capacity-Building in Agricultural Research in Post-War Sierra Leone

    Science.gov (United States)

    Gboku, Matthew L. S.; Bebeley, Jenneh F.

    2016-01-01

    This paper examines how the Sierra Leone Agricultural Research Institute (SLARI) used training and development to build capacity for innovation in agricultural research following the country's civil war which ended in 2002. The Institute's training for innovation addressed different agricultural product value chains (APVCs) within the framework of…

  2. The Mono Arch, eastern Sierra region, California: Dynamic topography associated with upper-mantle upwelling?

    Science.gov (United States)

    Jayko, A.S.

    2009-01-01

    A broad, topographic flexure localized east of and over the central and southern Sierra Nevada, herein named the Mono Arch, apparently represents crustal response to lithospheric and/or upper-mantle processes, probably dominated by mantle upwelling within the continental interior associated Pacific-North American plate-boundary deformation. This zone of flexure is identified through comparison between the topographic characteristics of the active Cascade volcanic arc and backarc regions with the analogous former arc and backarc in the Sierra Nevada and eastern Sierra Nevada. Serial topographic profiles measured normal to the modern Cascade backarc reveal an accordance of topographic lows defined by valley floors with an average minimum elevation of ???1400-1500m for over 175km to the southeast. Although the accordance drops in elevation slightly to the south, the modern Cascade backarc region is remarkably level, and is characterized by relief up to ???750m above this baseline elevation. By contrast, serial topographic profiles over the former arc and backarc transitions of the eastern Sierra region exhibit a regional anticlinal warping defined by accordant valley floors and by a late Miocene-early Pliocene erosion surface and associated deposits. The amplitude of this flexure above regionally flat baseline elevations to the east varies spatially along the length of the former Sierran arc, with a maximum of ???1000m centred over the Bridgeport Basin. The total zone of flexure is approximately 350km long N-S and 100km wide E-W, and extends from Indian Wells Valley in the south to the Sonora Pass region in the north. Previous geophysical, petrologic, and geodetic studies suggest that the Mono Arch overlies a zone of active mantle upwelling. This region also represents a zone crustal weakness formerly exploited by the middle-to-late Miocene arc and is presently the locus of seismic and volcanic activities. This seismic zone, which lies east of the Sierra Nevada block

  3. Sierra cooperative ozone impact assessment study: Year 4. Volume 2, Part B. 1994 hourly data tabulations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, J.J.; Dixon, A.J.

    1995-05-01

    The purpose of the Sierra Cooperative Ozone Impact Assessment Study (SCOIAS) was to characterize ozone concentration and meteorological conditions in mixed conifer forests on the western slope of the Sierra Nevada. The report summarizes the data collected in 1994. The major tasks were to continue aerometric monitoring at six stations in five national forests, and to measure leaf water potential as a factor influencing ozone uptake by pine trees growing near the monitoring stations. The six stations were located at Mountain Home in the Sequoia, Shaver Lake and Jerseydale in the Sierra, Five-Mile in the Stanislaus, Sly Park in the El Dorado, and White Cloud in the Tahoe National Forests.

  4. Status and understanding of groundwater quality in the Tahoe-Martis, Central Sierra, and Southern Sierra study units, 2006-2007--California GAMA Priority Basin Project

    Science.gov (United States)

    Fram, Miranda S.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the Tahoe-Martis, Central Sierra, and Southern Sierra study units was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The three study units are located in the Sierra Nevada region of California in parts of Nevada, Placer, El Dorado, Madera, Tulare, and Kern Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board, in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The project was designed to provide statistically robust assessments of untreated groundwater quality within the primary aquifer systems used for drinking water. The primary aquifer systems (hereinafter, primary aquifers) for each study unit are defined by the depth of the screened or open intervals of the wells listed in the California Department of Public Health (CDPH) database of wells used for municipal and community drinking-water supply. The quality of groundwater in shallower or deeper water-bearing zones may differ from that in the primary aquifers; shallower groundwater may be more vulnerable to contamination from the surface. The assessments for the Tahoe-Martis, Central Sierra, and Southern Sierra study units were based on water-quality and ancillary data collected by the USGS from 132 wells in the three study units during 2006 and 2007 and water-quality data reported in the CDPH database. Two types of assessments were made: (1) status, assessment of the current quality of the groundwater resource, and (2) understanding, identification of the natural and human factors affecting groundwater quality. The assessments characterize untreated groundwater quality, not the quality of treated drinking water delivered to consumers by water purveyors. Relative-concentrations (sample concentrations divided by benchmark concentrations) were used for evaluating groundwater quality for those

  5. Deep Crustal Earthquakes and Repeating Earthquakes in the West-Central Sierra Nevada, Western USA

    Science.gov (United States)

    Hurd, O.; Frassetto, A.; Zandt, G.; Gilbert, H.; Jones, C.; Owens, T. J.

    2006-12-01

    The Sierra Nevada EarthScope Project (SNEP) is a multiple institution, collaborative research project focused on investigating the structure and evolution of the Sierra Nevada batholith in eastern California. The first phase of the project (summer 2005-summer 2006) saw the deployment of over forty (40) broadband seismometers spanning the central Sierra Nevada from Fresno, California to just south of the Lake Tahoe region. These seismic stations recorded many small, local earthquakes in both the western foothills and high Sierra Nevada that were mostly located from 20 to 120 km north of Fresno and were not present in other regional catalogs. Seismicity in this region is notable because it occurs in the interior of a plate away from major known faults. Ninety (90) events were picked on as many as 20 SNEP stations and located. These events occurred from late May 2005 to late January 2006 at a rate of ~10 per month and were located between 10 and 35 km depth. Many of the events fall within two distinct clusters beneath the array. The first cluster contains ~45 events and is located 30-70 km east of Merced, California and 30-90 km north of Fresno, California. The second represents ~30 events and is centered about the southern Yosemite National Park region. Average depth of the events in the first cluster is ~27 km compared to ~16 km for the events in the second. Past studies have found that events from similar locations in the western Sierra Nevada foothills exhibited ML magnitudes from 0 to 3.2 and had focal mechanisms displaying strike-slip faulting combined with normal and reverse components (Wong and Savage, 1983, BSSA). Direct comparison between waveforms of picked events occurring in small clusters (2-5 events) found that some events had nearly identical waveforms. This suggests similar rupture locations and characteristics despite the events having occurred a couple days to several weeks apart.

  6. Composition of modern sand from the Sierra Nevada, California, USA: Implications for actualistic petrofacies of continental-margin magmatic arcs

    OpenAIRE

    Ingersoll, Raymond V.; Eastmond, Daniel J.

    2007-01-01

    The Sierra Nevada of California represents the roots of a long-lived magmatic arc (primarily Cretaceous) that is presently being dissected as the range is uplifted, beginning in the south and progressing northward. This dissection is occurring concurrently with northward migration of the Mendocino triple junction, south of which magmatic-arc activity is absent, and north of which magmatic-arc activity continues. A north-to-south transect along the Sierra Nevada represents transitions of activ...

  7. Female Genital Mutilation in Sierra Leone: Forms, Reliability of Reported Status, and Accuracy of Related Demographic and Health Survey Questions

    OpenAIRE

    Owolabi Bjälkander; Donald S Grant; Vanja Berggren; Heli Bathija; Lars Almroth

    2013-01-01

    Objective. To determine forms of female genital mutilation (FGM), assess consistency between self-reported and observed FGM status, and assess the accuracy of Demographic and Health Surveys (DHS) FGM questions in Sierra Leone. Methods. This cross-sectional study, conducted between October 2010 and April 2012, enrolled 558 females aged 12–47 from eleven antenatal clinics in northeast Sierra Leone. Data on demography, FGM status, and self-reported anatomical descriptions were collected. Genital...

  8. Evaluating potential overlap between pack stock and Sierra Nevada bighorn sheep (Ovis canadensis sierrae) in Sequoia and Kings Canyon National Parks, California

    Science.gov (United States)

    Klinger, Robert C.; Few, Alexandra P.; Knox, Kathleen A.; Hatfield, Brian E.; Clark, Jonathan; German, David W.; Stephenson, Thomas R.

    2015-01-01

    Pack stock (horses, mules, burros, llamas, and goats) are frequently assumed to have negative effects on public lands, but there is a general lack of data to be able to quantify the degree to which this is actually the case. Sequoia and Kings Canyon National Parks have received complaints that pack stock may affect Sierra Nevada bighorn sheep (Ovis canadensis sierrae; SNBS), a federally endangered subspecies that occurs in largely disjunct herds in the Sierra Nevada Range of California. The potential effects are thought to be displacement of SNBS from meadows on their summer range (altered habitat use) or, more indirectly, through changes in SNBS habitat or forage quality. Our goals were to conduct an association analysis to quantify the degree of potential spatial overlap in meadow use between SNBS and pack stock and to compare differences in vegetation community composition, structure, and diversity among meadows with different levels of use by bighorn sheep and pack stock. For the association analysis, we used two approaches: (1) we quantified the proportion of meadows that were within the herd home ranges of bighorn sheep and were potentially open to pack stock, and, (2) we used Monte Carlo simulations and use-availability analyses to compare the proportion of meadows used by bighorn sheep relative to the proportional occurrence or area of meadows available to bighorn sheep that were used by pack stock. To evaluate potential effects of pack stock on meadow plant communities and SNBS forage, we sampled vegetation in 2011 and 2012 at 100 plots to generate data that allowed us to compare:

  9. A new species of Cryptotis (Mammalia, Eulipotyphla, Soricidae) from the Sierra de Perijá, Venezuelan-Colombian Andes

    Science.gov (United States)

    Quiroga-Carmona, Marcial; Woodman, Neal

    2015-01-01

    The Sierra de Perijá is the northern extension of the Cordillera Oriental of the Andes and includes part of the border between Colombia and Venezuela. The population of small-eared shrews (Mammalia, Eulipotyphla, Soricidae, Cryptotis) inhabiting the Sierra de Perijá previously was known from only a single skull from an individual collected in Colombia in 1989. This specimen had been referred to alternatively as C. thomasi and C. meridensis, but more precise definition of the known Colombian and Venezuelan species of Cryptotis has since excluded the Sierra de Perijá population from any named species. The recent collection of a specimen from the Venezuelan slope of Sierra de Perijá, prompted us to re-evaluate the taxonomic status of this population and determine its relationship with other Andean shrews. Our examination of the available specimens revealed that they possess a unique suite of morphological and morphometrical characters, and we describe the Sierra de Perijá population as a new species in the South American C. thomasi species group. Recognition of this new species adds to our knowledge of this genus in South America and to the biodiversity of the Sierra de Perijá.

  10. DATACIONES ARQUEOMAGNÉTICAS EN LA CIUDADELA DE TEOTIHUACAN, SIERRA DE LAS NAVAJAS Y XALASCO (Archaeomagnetic Datings in the Citadel of Teotihuacan, Sierra de las Navajas, and Xalasco

    Directory of Open Access Journals (Sweden)

    Anuar Gabriel Terán Guerrero

    2016-03-01

    Full Text Available El control cronoestratigráfico es fundamental para el desarrollo del trabajo arqueológico, por ello el arqueomagnetismo se ha constituido como una gran herramienta para las dataciones. En este trabajo se muestran los resultados de dataciones arqueomagnéticas mediante la determinación de la dirección de magnetización de pisos de estuco de tres sitios de la cultura teotihuacana: Ciudadela de Teotihuacan, Sierra de las Navajas y Xalasco, Tlaxcala. Esta cultura se desarrolló en el centro de México a partir del año 1 d. C., teniendo su mayor esplendor durante los siglos IV al VI d. C. Tres etapas constructivas fueron muestreadas en la ciudadela de Teotihuacan: la preciudadela, la pirámide de Quetzalcóatl y la pirámide adosada. La Sierra de las Navajas en Hidalgo, a 50 km de Teotihuacan, era su principal proveedor de obsidiana, por lo que es de interés conocer sus periodos de ocupación. El motivo del análisis de los pisos de Xalasco, Tlaxcala, sitio de la cultura teotihuacana, es por encontrarse en la ruta de comunicación con la zona del Golfo de México. Utilizando la metodología y el programa de Pavón-Carrasco et al. (2014 se infieren intervalos de tiempo que nos permiten comprender la dinámica ocupacional de estos sitios. ENGLISH: The chronostratigraphic control is fundamental during any archaeological survey. Recent studies over the Americas showed that archaeomagnetism emerges as a great tool for absolute dating purposes. In this paper, we report new archaeomagnetic datings obtained from stucco floors belonging to three sites of Teotihuacan: the Citadel of Teotihuacan, Sierra de las Navajas and Xalasco, Tlaxcala. This culture developed in central Mexico from AD 1, having its greatest splendor during the 4th to 6th centuries AD. Three construction phases were sampled in the citadel of Teotihuacan: the pre-Citadel, the Pyramid of Quetzalcoatl and the terraced pyramid. The Sierra de la Navajas in Hidalgo, located 50 km from

  11. Diversidad de mamíferos de la Reserva Natural Sierra Nanchititla, México Diversity of mammals in the Natural Reserve Sierra Nanchititla, Mexico

    OpenAIRE

    Octavio Monroy-Vilchis; Martha M. Zarco-González; José Ramírez-Pulido; Ulises Aguilera-Reyes

    2011-01-01

    La Reserva Natural Sierra Nanchititla (RNSN), por su extensión, es la segunda área natural protegida del Estado de México; sin embargo, se desconoce gran parte de su biodiversidad. El objetivo de este trabajo fue estimar su diversidad mastofaunística. Se utilizó el trampeo directo para la colecta de mamíferos pequeños y trampas-cámara para el estudio de los mamíferos medianos y grandes. Se calculó la diversidad a partir del índice de Margalef, y se evaluaron la dominancia y la equidad mediant...

  12. DATACIONES ARQUEOMAGNÉTICAS EN LA CIUDADELA DE TEOTIHUACAN, SIERRA DE LAS NAVAJAS Y XALASCO (Archaeomagnetic Datings in the Citadel of Teotihuacan, Sierra de las Navajas, and Xalasco)

    OpenAIRE

    Anuar Gabriel Terán Guerrero; Ana María Soler Arechalde; Avto Goguitchaichvili; Cecilia Caballero-Miranda; Juan Morales; Jaime Urrutia-Fucugauchi

    2016-01-01

    El control cronoestratigráfico es fundamental para el desarrollo del trabajo arqueológico, por ello el arqueomagnetismo se ha constituido como una gran herramienta para las dataciones. En este trabajo se muestran los resultados de dataciones arqueomagnéticas mediante la determinación de la dirección de magnetización de pisos de estuco de tres sitios de la cultura teotihuacana: Ciudadela de Teotihuacan, Sierra de las Navajas y Xalasco, Tlaxcala. Esta cultura se desarrolló en el centro de Méxic...

  13. Geología y fracturas en la estructura San Pedro, sierra del Alto Río Seco, Sierras Subandinas, provincia de Salta

    OpenAIRE

    L. Di Marco

    2005-01-01

    La estructura San Pedro se encuentra en el sector central-septentrional de la unidad morfo-estructural de Sierras Subandinas. Su columna estratigráfica esta caracterizada por una compleja historia geológica en la que se superponen varias cuencas sedimentarias con distinto origen, con un relleno total de más de 10.000 m de espesor y desarrolladas en diferentes edades geológicas y bajo distintos ambientes. El yacimiento San Pedrito (niveles devónicos), ubicado en el bloque Acambuco de la cuenca...

  14. Diversidad de mamíferos de la Reserva Natural Sierra Nanchititla, México Diversity of mammals in the Natural Reserve Sierra Nanchititla, Mexico

    Directory of Open Access Journals (Sweden)

    Octavio Monroy-Vilchis

    2011-03-01

    Full Text Available La Reserva Natural Sierra Nanchititla (RNSN, por su extensión, es la segunda área natural protegida del Estado de México; sin embargo, se desconoce gran parte de su biodiversidad. El objetivo de este trabajo fue estimar su diversidad mastofaunística. Se utilizó el trampeo directo para la colecta de mamíferos pequeños y trampas-cámara para el estudio de los mamíferos medianos y grandes. Se calculó la diversidad a partir del índice de Margalef, y se evaluaron la dominancia y la equidad mediante los índices de Simpson y Shannon-Wiener, respectivamente. Se registraron 53 especies de mamíferos; 3 de ellas son el primer registro estatal, 10 son endémicas de México y 4 las considera en alguna categoría de vulnerabilidad el gobierno mexicano. En la zona habitan 5 de las 6 especies de felinos de México. La composición mastofaunística de la RNSN fue comparada con la de la sierra Purépecha, Michoacán, con la que comparte el 38% de las especies. De acuerdo con el índice de Jaccard, la similitud entre ambas es baja. Considerando los resultados, la importancia de la RNSN con respecto a su diversidad mastofaunística es evidente, así como la necesidad de delinear estrategias para su conservación.The Sierra Nanchititla Natural Reserve (SNNR is the second largest natural protected area in the State of Mexico, however its biodiversity is largely unknown. The aim of this research was to estimate its mammalian diversity. Direct trapping was used to capture small mammals and camera-trapping for the study of medium and large mammals. Diversity was calculated from Margalef's index, dominance and equity were evaluated through Simpson's and Shannon-Wiener indexes, respectively. Fifty three species were registered, 3 of them are the first record for the State of Mexico, 10 are endemic to Mexico and 4 are considered in some category of vulnerability by the Mexican government. The area is inhabited by 5 of the 6 Mexican felid species. The

  15. Registro de Nephridiophaga sp. (Protista: Nephridiophagidae en Apis mellifera (Hymenoptera: Apidae del Sur de la región Pampeana Record of Nephridiophaga sp. (Protista: Nephridiophagidae in Apis mellifera (Hymenoptera: Apidae of the southern Pampas

    Directory of Open Access Journals (Sweden)

    Santiago Plischuk

    2011-12-01

    Full Text Available Durante estudios prospectivos tendientes a la detección de protistas asociados a ápidos en la región Pampeana, se observó la presencia de esporos ovales bicóncavos y grupos de esporos (cúmulos en los túbulos de Malpighi de abejas de Dufaur, partido de Saavedra, sudoeste de la provincia de Buenos Aires. Los esporos maduros midieron 4,8 ± 0,05 x 2,4 ± 0,03 μm y la carga (intensidad promedió 5,71 ± 1,49 x 10(6 esporos/abeja. Las detecciones se efectuaron entre julio y octubre de 2006 y la prevalencia en las colmenas positivas osciló entre 1 y 16,7 %. Las características morfológicas de los esporos, el lugar de desarrollo y la especie huésped involucrada sugieren que el microorganismo en cuestión, pertenece al género Nephridiophaga y sería N. apis Ivani, especie tipo cuyo conocimiento es extremadamente limitado. El hallazgo constituye el primer registro de un nefridiofágido asociado a A mellifera fuera del continente europeo.During surveys for the detection of protists associated to Apidae in the Pampas region, biconcave oval spores, and spore clumps were observed in the Malpighian tubules of honeybees from Dufaur, Saavedra county, southwestern Buenos Aires province. Mature spores measured 4.8 ± 0.05 x 2.4 ± 0.03 μm, and mean spore load was 5.71 ± 1.49 x 10(6 per honeybee. Detections were from July to October 2006, and prevalence in positive colonies ranged from 1 to 16.7%. Morphology of the spores, the site of development, and the identity of the host species suggest that the isolated microorganism belongs to the genus Nephridiophaga and would be N apis Ivani, the type species, knowledge on which is extremely limited. The finding constitutes the first record of a nephridiophagid in honeybees outside of Europe.

  16. Virajes en las políticas públicas de tierras. Continuidades y discontinuidades a partir de la segunda mitad del siglo XX, región pampeana. Argentina

    Directory of Open Access Journals (Sweden)

    Marina Bustamante

    2011-01-01

    Full Text Available El acceso a la tierra -tanto a la propiedad como al usufructo- es de capital importancia en el desarrollo socio-económico de la Región Pampeana argentina y, por tanto, ha sido objeto de diversas políticas públicas. Sin embargo, su formulación e implementación ha sido dinámica y cambiante, en función del contexto mundial y nacional y en función de voluntades políticas que responden y promueven un determinado estilo de desarrollo. A partir de dicha consideración, se identifican - desde mediados del siglo XX- dos etapas con un tratamiento de la cuestión de la tierra y de las relaciones sociales en juego nítidamente diferentes: una primera, en la cual las políticas agrarias parten de considerar a la tierra como bien de trabajo con función social -lo que se plasma en medidas de acción sobre la tenencia de la tierra-, y una segunda en la cual es considerada sólo como un bien de producción, de renta y especulación -lo que se materializa en políticas de apropiación de excedentes económicos-. Se pretende comprender cómo se articulan las voluntades políticas con los proyectos económicos y con las demandas sociales, para construir así un modelo de país acorde a cada momento histórico. Con tal propósito, se conceptualiza la política agropecuaria y las múltiples características que la definen, para continuar con el análisis de las sucesivas políticas públicas de tierras así como del contexto socio-económico en el cual se desarrollan. Para emprender tal tarea se recurre a la lectura crítica y analítica de cuantioso material bibliográfico, consistente en trabajos científicos y técnicos, legislaciones específicas, artículos periodísticos, así como publicaciones varias que contribuyen a enriquecer la temática

  17. Structure of Sierra Blanca (Alpujarride Complex, west of the Betic Cordillera

    Directory of Open Access Journals (Sweden)

    Andreo, B.

    1995-04-01

    Full Text Available Sierra Blanca, situated in the SW of Málaga, forms part of the Blanca unit, belonging to the Alpujarride Complex of the Betic Cordillera. Its lithologic sequences are made up of a group of migmatites, gneisses and schists and an upper formation of marbles (white dolomitic and the bottom and blue calcareous towards the top, linked with a transitional contact. The structure of Sierra Blanca is comprised of folds, generally isoclinal, with reversed limbs and with important tectonic transpositions, the direction of which is approximately E-W in the eastern area and N-S and E-W in the West. In both areas the folds present opposing vergences, consistently towards the interior of the sierra. The origin of these structures is explained with a model of westerly movements of the Blanca unit, in relation to the Los Reales unit, with the formation of frontal and lateral folds. In its advancement, the western part of Sierra Blanca underwent an important anti-clockwise rotation responsible for the co-existence of folds in N-S and E-W directions. These structures occurred under ductile conditions, owing to the presence of important overthrusting peridotitic masses of the Los Reales unit. This model of westerly displacement is inserted in the process undergone by the Betic-Rif Internal Zones (with Blanca and Los Reales units included which occurred at the end of the Oligocene-Early Miocene when the Gibraltar arch began to be formed.Sierra Blanca, situada al SW de Málaga, forma parte de la unidad de Blanca que pertenece al complejo Alpujárride de la Cordillera Bética. Su secuencia litológica está compuesta por un conjunto inferior de migmatitas, gneises y esquistos, y por una formación superior de mármoles, blancos dolomíticos en la base y mármoles calizos azules hacia la parte superior, entre los que existe un tránsito gradual. La estructura de Sierra Blanca está formada por pliegues, generalmente isoclinales, con flancos invertidos que muestran

  18. A Late Proterozoic Early Paleozoic magmatic cycle in Sierra de la Ventana, Argentina

    Science.gov (United States)

    Gregori, D. A.; López, V. L.; Grecco, L. E.

    2005-06-01

    Late Proterozoic-Early Paleozoic intrusive and volcanic rocks of Sierra de la Ventana can be grouped into two magmatic assemblages: the Meyer and Cochenleufú suites. The older (700-570 Ma) is composed of S-type quartz-monzodiorites, synogranites, and monzogranites associated with andesites and rhyolites and related to volcanic-arc and postcollisional settings. The younger (540-470 Ma) corresponds to highly fractionated homogeneous A-type monzogranites, linked to final plutonic events during postorogenic extension in collisional belts. Strong similarities between Sierra de la Ventana magmatic rocks and the S- and A-type granites of the Cape granite suite in South Africa allow positive correlation. In both areas, primitive volcanic arcs or collisional orogens are recognized. Continuous transpressional shearing between the Swartland and Tygerberg terranes in the Saldania belt may have triggered the generation and emplacement of both suites.

  19. Propuesta para la construcción del concepto de interculturalldad caso la sierra nevada

    Directory of Open Access Journals (Sweden)

    Julio Marino Barragán

    2014-02-01

    Full Text Available La imponente Sierra Nevada de Santa Marta controla buena parte del clima de toda la  región, gracias a la montaña sagrada los huracanes no son tan devastadores como sí la son por otras latitudes. Así como la Sierra, el  departamento del Magdalena es una de las regiones culturales más ricas del país y de la cuenca del Caribe. En el Magdalena encontramos poblados típicos de la múltiple mezcla, del mestizaje de los sinnúmeros de vertientes culturales que se arriesgan a venir por estas tierras, desde el cercano oriente, la esteparia Rusia.

  20. Climate controls on forest productivity along the climate gradient of the western Sierra Nevada

    Science.gov (United States)

    Kelly, A. E.; Goulden, M. L.

    2010-12-01

    The broad climate gradient of the slopes of the western Sierra Nevada mountains supports ecosystems spanning extremes of productivity, biomass, and function. We are using this natural environmental gradient to understand how climate controls NPP, aboveground biomass, species' range limits, and phenology. Our experimental approach combines eddy covariance, sap flow, dendrometer, and litterfall measurements in combination with soil and hydrological data from the Southern Sierra Critical Zone Observatory (SSCZO). We have found that above about 2500 m, forest productivity is limited by winter cold, while below 1200 m, productivity is likely limited by summer drought. The sweet spot between these elevations has a nearly year-long growing season despite a snowpack that persists for as long as six months. Our results show that small differences in temperature can markedly alter the water balance and productivity of mixed conifer forests.

  1. Thymus × pseudogranatensis (Labiatae, nuevo híbrido para Sierra Nevada (España

    Directory of Open Access Journals (Sweden)

    Lorite, Juan

    2011-12-01

    Full Text Available Thymus × pseudogranatensis Vizoso, F.B. Navarro & Lorite, a new spontaneous hybrid of Th. granatensis Boiss. subsp. granatensis and Th. zygis L. subsp. gracilis (Boiss. R. Morales, collected in the dolomitic areas of Sierra Nevada (SE Spain, is described. Morphological characters of the new nothospecies are analysed and its distribution and ecology are discussed.Se describe Thymus × pseudogranatensis Vizoso, F.B. Navarro & Lorite, un nuevo híbrido entre Th. granatensis Boiss. subsp. granatensis y Th. zygis L. subsp. gracilis (Boiss. R. Morales, colectado en la orla dolomítica de Sierra Nevada (SE de España. Se analizan los caracteres morfológicos de la nueva notoespecie y se aportan detalles sobre su hábitat y distribución.

  2. A new species of Rhadinella (Serpentes: Colubridae) from the Sierra Madre del Sur of Guerrero, Mexico.

    Science.gov (United States)

    Campillo, Gustavo; Dávila-Galavíz, Luis Fernando; Flores-Villela, Oscar; Campbell, Jonathan A

    2016-01-01

    We describe a new species of Rhadinella from the Sierra Madre del Sur of Guerrero, Mexico, a region where the genus was previously unknown. This diminutive species is a member of a group of snakes previously allocated in the Rhadinaea godmani group, and more recently transferred to the genus Rhadinella. These snakes may have conspicuous dark longitudinal striping on a pale brown to orange background or may have dark brown to blackish dorsal ground coloration, which mostly or completely obfuscates a pattern of longitudinal striping. The new species is mostly dark with barely discernible slightly paler or darker striping (depending on how striping is interpreted). The closest relative of the new species, on the basis of morphological similarities and biogeography, appears to be Rhadinella donaji which occurs to the east in the Sierra Madre del Sur of Oaxaca about 275 km from the type-locality of the new species.

  3. High altitude wind velocity at Sierra Negra and San Pedro M\\'artir

    CERN Document Server

    Carrasco, E; Carramiñana, A; Carrasco, Esperanza; Avila, Remy; Carrami\\~nana, Alberto

    2004-01-01

    It has been proposed that the global circulation of the atmosphere winds at 200 mb can be used as a criteria to establish the suitability of a site for the development of adaptive optics techniques such as slow wavefront corrugation correction. By using the NOAA NCEP/NCAR Reanalysis data base we analyze the monthly average wind velocity at 200 mb for a 16 year period, for two sites in Mexico: Sierra Negra and San Pedro M\\'artir. We compare the results with those obtained for Mauna Kea, Paranal and La Silla, with Maidanak in Uzbekistan, and with Gamsberg in Namibia. We show that for all the sites under study there is a yearly wind speed modulation and we model that modulation. Our results show that Sierra Negra and San Pedro M\\'artir are comparable with the best observatory sites as Mauna Kea and are amongst the most advantageous sites to apply adaptive optics techniques.

  4. Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone.

    Science.gov (United States)

    Fang, Li-Qun; Yang, Yang; Jiang, Jia-Fu; Yao, Hong-Wu; Kargbo, David; Li, Xin-Lou; Jiang, Bao-Gui; Kargbo, Brima; Tong, Yi-Gang; Wang, Ya-Wei; Liu, Kun; Kamara, Abdul; Dafae, Foday; Kanu, Alex; Jiang, Rui-Ruo; Sun, Ye; Sun, Ruo-Xi; Chen, Wan-Jun; Ma, Mai-Juan; Dean, Natalie E; Thomas, Harold; Longini, Ira M; Halloran, M Elizabeth; Cao, Wu-Chun

    2016-04-19

    Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014-2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission.

  5. Gold Mining Impacts on Food Chain Mercury in Northwestern Sierra Nevada Streams

    OpenAIRE

    Slotton, Darell G; Ayers, Shaun M; Reuter, John E; Goldman, Charles R

    1995-01-01

    More than three million kilograms of mercury are estimated to have been lost into northwestern Sierra Nevada rivers during the course of gold mining in the Gold Rush period of the last century (1840s - 1880s). Mercury was used extensively in the gold recovery process to amalgamate fine gold particles. Gold mining has continued at a less intensive scale through the present, with a relative resurgence of dredging operations during the past decade. In this study, we investigated mercury levels i...

  6. Precipitation trends in the High Sierra of California inferred from streamflow and snowpack observations

    Science.gov (United States)

    Henn, B. M.; Clark, M. P.; Kavetski, D.; McGurk, B. J.; Painter, T. H.; Lundquist, J. D.

    2015-12-01

    Directly observing basin-mean precipitation in the high-elevation basins of the Sierra Nevada of California is challenging, due to the sparse network of precipitation gauges at these altitudes and due to snow undercatch errors. However, numerous observations of streamflow and snowpack are also made in the Sierra, which offer additional information about the water balance of the basin with which to estimate precipitation. We develop and apply a Bayesian methodology for inferring basin-mean precipitation from streamflow and snowpack observations, in multiple snow-dominated Sierra basins. To do this, we calibrate semi-lumped hydrologic models representing each basin, using streamflow and snowpack to infer multiplicative corrections to precipitation forcing data, and thus improve basin-mean precipitation estimates. We use unimpaired streamflow observations from multiple basins across the Sierra from the mid-20th century to the present, as well as snowpack observations combined from snow pillows, courses and airborne LIDAR observations (ASO). For each basin, mean precipitation is inferred both as a long-term average and for individual water years. We investigate the inferred spatial patterns of precipitation in comparison to standard climatological and daily gridded precipitation datasets, finding significant differences in some basins and in some water years. For example, see figure of different estimates of 1982-2006 mean annual precipitation for several Yosemite-area basins (figure from manuscript currently in review at Water Resources Research). We also investigate the precision and robustness of inferring basin-mean precipitation rates from streamflow and snowpack observations. Uncertainties in this approach are associated with uncertainties in lumped hydrologic model structure and in the methodology of translating point snow observations to the basin scale. Using both snowpack and streamflow observations in the inference likely reduces these uncertainties

  7. Resilience Through Disturbance: Effects of Wildfire on Vegetation and Water Balance in the Sierra Nevadas

    Science.gov (United States)

    Boisrame, G. F. S.; Thompson, S. E.; Stephens, S.; Collins, B.; Tague, N.

    2015-12-01

    A century of fire suppression in the Western United States has drastically altered the historically fire-adapated ecology in California's Sierra Nevada Mountains. Fire suppression is understood to have increased the forest cover, as well as the stem density, canopy cover and water demand of montane forests, reducing resilience of the forests to drought, and increasing the risk of catastrophic fire by drying the landscape and increasing fuel loads. The potential to reverse these trends by re-introducing fire into the Sierra Nevada is highly promising, but the likely effects on vegetation structure and water balance are poorly quantified. The Illilouette Creek Basin in Yosemite National Park represents a unique experiment in the Sierra Nevada, in which managers have moved from fire suppression to allowing a near-natural fire regime to prevail since 1972. Changes in vegetation structure in the Illilouette since the restoration of natural burning provides a unique opportunity to examine how frequent, mixed severity fires can reshape the Sierra Nevada landscape. We characterize these changes from 1969 to the present using a combination of Landsat products and high-resolution aerial imagery. We describe how the landscape structure has changed in terms of vegetation composition and its spatial organization, and explore the drivers of different post-fire vegetation type transitions (e.g. forest to shrubland vs. forest to meadow). By upscaling field data using vegetation maps and Landsat wetness indices, we explore how these vegetation transitions have impacted the water balance of the Illilouette Creek Basin, potentially increasing its resilience in the face of drought, climate change, and catastrophic fire. In a region that is adapted to frequent disturbance from fire, this work helps us understand how allowing such natural disturbances to take place can increase the sustainability of diverse landscapes in the long term.

  8. Inversion for Eigenvalues and Modes Using Sierra-SD and ROL.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Aquino, Wilkins [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ridzal, Denis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kouri, Drew Philip [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    In this report we formulate eigenvalue-based methods for model calibration using a PDE-constrained optimization framework. We derive the abstract optimization operators from first principles and implement these methods using Sierra-SD and the Rapid Optimization Library (ROL). To demon- strate this approach, we use experimental measurements and an inverse solution to compute the joint and elastic foam properties of a low-fidelity unit (LFU) model.

  9. Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone

    Science.gov (United States)

    Fang, Li-Qun; Yang, Yang; Jiang, Jia-Fu; Yao, Hong-Wu; Kargbo, David; Li, Xin-Lou; Jiang, Bao-Gui; Kargbo, Brima; Tong, Yi-Gang; Wang, Ya-Wei; Liu, Kun; Kamara, Abdul; Dafae, Foday; Kanu, Alex; Jiang, Rui-Ruo; Sun, Ye; Sun, Ruo-Xi; Chen, Wan-Jun; Ma, Mai-Juan; Dean, Natalie E.; Thomas, Harold; Longini, Ira M.; Halloran, M. Elizabeth; Cao, Wu-Chun

    2016-01-01

    Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014−2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission. PMID:27035948

  10. Exploring the decision-­making processes during childbirth in rural Sierra Leone

    OpenAIRE

    Treacy, Laura Claire

    2014-01-01

    High rates of maternal mortality remain a persistent problem in Sierra Leone. Efforts to reduce these high rates have included initiatives to encourage more women to deliver at health facilities. Despite the introduction of free health care for pregnant women, many women still continue to deliver at home, with few having access to a skilled birth attendant. In addition, inequalities between rural and urban areas in accessing and utilising health facilities persist. Further insight into how an...

  11. Impact of civil war on emotion recognition: the denial of sadness in Sierra Leone

    OpenAIRE

    Umiltà, Maria Allessandra; Wood, Rachel; Loffredo, Francesca; Ravera, Roberto; Gallese, Vittorio

    2013-01-01

    Studies of children with atypical emotional experience demonstrate that childhood exposure to high levels of hostility and threat biases emotion perception. This study investigates emotion processing, in former child soldiers and non-combatant civilians. All participants have experienced prolonged violence exposure during childhood. The study, carried out in Sierra Leone, aimed to examine the effects of exposure to and forced participation in acts of extreme violence on the emotion processing...

  12. Impact of civil war on emotion recognition: the denial of sadness in Sierra Leone.

    OpenAIRE

    Maria Alessandra eUmilta'; Rachel eWood; Francesca eLoffredo; Roberto eRavera; Vittorio eGallese

    2013-01-01

    Studies of children with atypical emotional experience demonstrate that childhood exposure to high levels of hostility and threat biases emotion perception. This study investigates emotion processing, in former child soldiers and non-combatant civilians. All participants have experienced prolonged violence exposure during childhood. The study, carried out in Sierra Leone, aimed to examine the effects of exposure to and forced participation in acts of extreme violence on the emotion processing...

  13. Estimating the basic reproductive ratio for the Ebola outbreak in Liberia and Sierra Leone

    OpenAIRE

    Khan, Adnan; Naveed, Mahim; Dur-e-Ahmad, Muhammad; Imran, Mudassar

    2015-01-01

    Background Ebola virus disease has reemerged as a major public health crisis in Africa, with isolated cases also observed globally, during the current outbreak. Methods To estimate the basic reproductive ratio R0, which is a measure of the severity of the outbreak, we developed a SEIR (susceptible-exposed-infected-recovered) type deterministic model, and used data from the Centers for Disease Control and Prevention (CDC), for the Ebola outbreak in Liberia and Sierra Leone. Two different data ...

  14. Neoproterozoic peritidal facies of the Villa Monica Formation, Sierra la J uanita, Tandilia

    OpenAIRE

    Marcelo Manassero; Patricia E Zalba; Martin E Morosi

    2012-01-01

    From field observations and petrographic studies, a complex association of peritidal carbonate and siliciclastic facies have been recognized in the Villa Mónica Formation (Neoproterozoic), Sierra La Juanita, outcropping at the quarries of Estancia La Siempre Verde, Estancia La Placeres and Estancia Don Camilo, where carbonate facies have not been described 'in situ since their discovery in 1967. Three different detailed stratigraphic sections are fully described. On the one hand, calcareous f...

  15. The process and practice of diagnosis: innovations in diagnostics for Lassa fever in Sierra Leone

    OpenAIRE

    Wilkinson, Annie

    2013-01-01

    This thesis is about the process and practice of diagnosis and the implications of new diagnostic technologies in low resource settings. As a setting and a disease which has seen significant investment in diagnostics, Lassa fever in Sierra Leone has been selected as a case study to examine these themes. In this thesis, 'new diagnostic technologies’ refers to laboratory-based diagnostics which are fast, reliable, accurate and can be used in low income settings. The starting point of this thesi...

  16. Hydrologic response and watershed sensitivity to climate warming in California's Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Sarah E Null

    Full Text Available This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air temperature uniformly by 2 degrees, 4 degrees, and 6 degrees C, but leave other climatic variables unchanged from observed values. Results are analyzed for changes in mean annual flow, peak runoff timing, and duration of low flow conditions to highlight which watersheds are most resilient to climate warming within a region, and how individual watersheds may be affected by changes to runoff quantity and timing. Results are compared with current water resources development and ecosystem services in each watershed to gain insight into how regional climate warming may affect water supply, hydropower generation, and montane ecosystems. Overall, watersheds in the northern Sierra Nevada are most vulnerable to decreased mean annual flow, southern-central watersheds are most susceptible to runoff timing changes, and the central portion of the range is most affected by longer periods with low flow conditions. Modeling results suggest the American and Mokelumne Rivers are most vulnerable to all three metrics, and the Kern River is the most resilient, in part from the high elevations of the watershed. Our research seeks to bridge information gaps between climate change modeling and regional management planning, helping to incorporate climate change into the development of regional adaptation strategies for Sierra Nevada watersheds.

  17. Sierra Chata field, Argentina: geophysical discovery and development of a stratigraphic trap

    Energy Technology Data Exchange (ETDEWEB)

    Woller, Kevin L. [Mobil Technology Co. (United States); Louder, William T. [Santa Fe Energy Resources (Argentina)

    1999-07-01

    Drilling a seismic amplitude anomaly in the Cretaceous Mulichinco Sandstone discovered the Sierra Chata gas field in the Neuquen Basin, Argentina. This well followed several unsuccessful attempts to locate hydrocarbons in the block, including a well only 3 kilometers from the closet producing well in the field. Since that time, seismic data has played the major role in locating new wells, all 24 of which have been completed as producers. (author)

  18. Impact of Summer Cattle Grazing on the Sierra Nevada Watershed: Aquatic Algae and Bacteria

    OpenAIRE

    Derlet, Robert W.; Richards, John R.; Tanaka, Lidia L.; Curtis Hayden; K. Ali Ger; Goldman, Charles R.

    2012-01-01

    Introduction. We evaluated periphytic algal and microbial communities to assess the influence of human and cattle impact on Sierra water quality. Methods. 64 sites (lakes and streams from Lake Tahoe to Sequoia National Park, California) were sampled for suspended indicator bacteria and algae following standardized procedures. The potential for nonpoint pollution was divided into three categories: cattle-grazing areas (C), recreation use areas (R), or remote wildlife areas (W). Results. Periph...

  19. Soil moisture response to snowmelt and rainfall in a sierra nevada mixed-conifer forest

    OpenAIRE

    Bales, RC; Hopmans, JW; O'Geen, AT; Meadows, M.; Hartsough, PC; Kirchner, P; Hunsaker, CT; Beaudette, D

    2011-01-01

    Using data from a water-balance instrument cluster with spatially distributed sensors we determined the magnitude and within-catchment variability of components of the catchmentscale water balance, focusing on the relationship of seasonal evapotranspiration to changes in snowpack and soil moisture storage. Co-located, continuous snow depth and soil moisture measurements were deployed in a rain-snow transition catchment in the mixed-conifer forest in the Southern Sierra Nevada. At each elevati...

  20. Communicable Diseases and Gender Norms in the Sierra Leone Armed Forces

    OpenAIRE

    Djibo, Audrey Marie-Delphine

    2015-01-01

    BACKGROUND : Communicable diseases affecting military personnel in sub-Saharan Africa impact the overall health of soldiers and their contacts, and include human immunodeficiency virus (HIV) and syphilis infections. Understanding the risks of acquisition and transmission of sexually transmissible infections, particularly of HIV, is critical in shaping effective prevention interventions among soldiers in Sierra Leone. Sexual behaviors including partner types and condom use, as well as other be...

  1. Dataset of Phenology of Mediterranean high-mountain meadows flora (Sierra Nevada, Spain)

    OpenAIRE

    Antonio Jesús Pérez-Luque; Cristina Patricia Sánchez-Rojas; Regino Zamora; Ramón Pérez-Pérez; Francisco Javier Bonet

    2015-01-01

    Abstract Sierra Nevada mountain range (southern Spain) hosts a high number of endemic plant species, being one of the most important biodiversity hotspots in the Mediterranean basin. The high-mountain meadow ecosystems (borreguiles) harbour a large number of endemic and threatened plant species. In this data paper, we describe a dataset of the flora inhabiting this threatened ecosystem in this Mediterranean mountain. The dataset includes occurrence data for flora collected in those ecosystems...

  2. Dataset of Phenology of Mediterranean high-mountain meadows flora (Sierra Nevada, Spain)

    OpenAIRE

    Pérez-Luque, Antonio Jesús; Sánchez-Rojas, Cristina Patricia; Zamora, Regino; Pérez-Pérez, Ramón; Bonet, Francisco Javier

    2015-01-01

    Sierra Nevada mountain range (southern Spain) hosts a high number of endemic plant species, being one of the most important biodiversity hotspots in the Mediterranean basin. The high-mountain meadow ecosystems (borreguiles) harbour a large number of endemic and threatened plant species. In this data paper, we describe a dataset of the flora inhabiting this threatened ecosystem in this Mediterranean mountain. The dataset includes occurrence data for flora collected in those ecosystems in two p...

  3. The Special Court for Sierra Leone:Outreach, Legacy and Impact

    OpenAIRE

    Kerr, Rachel; Lincoln, Jessica

    2008-01-01

    The Special Court for Sierra Leone (SCSL) represents a new model of international criminal justice, mixing elements of international and domestic law and procedure and involving international and local staff. High hopes surrounded the creation of the Special Court, which was intended to remedy some of the shortfalls of previous attempts to deliver international criminal justice in a number of concrete ways: it was supposed to be more modest in its aims, complete trials in a shorter period, be...

  4. Skill evaluation of water supply forecasts in western Sierra Nevada and Colorado River basins

    OpenAIRE

    Harrison, Brent

    2014-01-01

    Runoff records from thirteen major river basins on the western slope of the Sierra Nevada in California were compared to runoff forecasts for those watersheds to determine the skill of those runoff forecasts. The forecasts, some dating back to the 1930's, were made at the beginning of the months of February, March, April and May. An array of summary, correlation and categorical skill measures were computed for each forecast and associated observation. The same array of skill measures were c...

  5. Psychosocial stressors and support needs of survivors of Ebola virus disease, Bombali District, Sierra Leone, 2015

    OpenAIRE

    Waheed Ariyo Bakare; Olayinka Stephen Ilesanmi; Edmund Presiror Nabena; Temitope Famuyide

    2016-01-01

    Ebola virus disease (EVD) survivors are increasing. There is a need to document their psychosocial stressors and support needs to enable appropriate interventions. The aim of this study was to document psychosocial stressors and support needs of EVD survivors in Bombali District, Sierra Leone, in 2015. Qualitative and quantitative methods were used. A cross-sectional study design (questionnaire) was used for quantitative data collection from 299 survivors, while in-depth interview was done fo...

  6. Habitat Preferences of Butterflies in the Bumbuna Forest, Northern Sierra Leone

    OpenAIRE

    Sundufu, Abu James; Dumbuya, Rashida

    2008-01-01

    The habitat preferences of the butterfly fauna were studied in the Bumbuna Forest Reserve in northern Sierra Leone. The intact forest reserve and a secondary forest regrowth, disturbed as a result of slash-and-burn agriculture, were compared to savanna habitats. Of the 290 specimens collected, 195 butterfly species were included, of which significant proportion were Nymphalidae. Of the 147 forest species, 111 (75.5%) showed preferences for the forest habitats, while 70 (47.6%) and 34 (23.1%) ...

  7. DIAGNOSIS IMPORTANCE OF RURAL DEVELOPMENT OF A MODEL AGROFORESTAL IN PEASANT COMMUNITIES OF SIERRA DE HUAUTLA

    OpenAIRE

    Miguel Uribe-Gómez; Artemio Cruz-León; Dionicio Juárez-Ramón; Alejandro Lara-Bueno; José L. Romo-Lozano; Ramón Valdivia-Alcalá; Marcos Portillo-Vázquez

    2015-01-01

    Family agricultural is socioeconomically important in rural areas, but in Mexico, from the 80's this production system presents social stagnation. This type of agriculture presents a dynamic reality in the interests of each producer and limiting access to factors of production (land, labor and capital). In this investigation a methodology for analysis and diagnosis of production systems in rural areas, in two communities in the Country Sierra de Huautla Tepalcingo, Morelos, Mexico was applied...

  8. Fungi in the diets of northern flying squirrels and lodgepole chipmunks in the Sierra Nevada

    OpenAIRE

    Meyer, M D; North, M P; D. A. Kelt

    2005-01-01

    The diets of a fungal specialist, northern flying squirrel (Glaucomys sabrinus (Shaw, 1801)), and a dietary generalist, lodgepole chipmunk (Neotamias speciosus (Merriam, 1890)), were examined in the old-growth, mixed-conifer forest at the Teakettle Experimental Forest in California's southern Sierra Nevada. Spores of fungi were identified from fecal pellets collected from both species during spring and summer of 1999 through 2002. Frequency of fungi in the diets of both squirrel species was c...

  9. Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone.

    Science.gov (United States)

    Fang, Li-Qun; Yang, Yang; Jiang, Jia-Fu; Yao, Hong-Wu; Kargbo, David; Li, Xin-Lou; Jiang, Bao-Gui; Kargbo, Brima; Tong, Yi-Gang; Wang, Ya-Wei; Liu, Kun; Kamara, Abdul; Dafae, Foday; Kanu, Alex; Jiang, Rui-Ruo; Sun, Ye; Sun, Ruo-Xi; Chen, Wan-Jun; Ma, Mai-Juan; Dean, Natalie E; Thomas, Harold; Longini, Ira M; Halloran, M Elizabeth; Cao, Wu-Chun

    2016-04-19

    Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014-2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission. PMID:27035948

  10. Análisis radiocarbónico en una tafocenosis de la región pampeana (provincia de Buenos Aires, Argentina: Su vinculación con la Gran Seca de 1827-1832 Radiocarbon Analysis Of A Taphocenosis From The Pampean Region (Buenos Aires Province, Argentina And Its Relationships With The "Great Drought" Of 1827-1832

    Directory of Open Access Journals (Sweden)

    Eduardo P. Tonni

    2008-12-01

    Full Text Available Se estudió una tafocenosis compuesta por gran número de ejemplares de Equus caballus, Bos taurus y Ovis aries, sin selección etaria. Se realizó una datación radiocarbónica sobre el colágeno del hueso de un húmero de Bos taurus; la fecha obtenida resultó "moderna" (entre 1750 y 1950 AD. Sin embargo, la concentración ΔC14 en el espécimen y su comparación con la curva de concentración ΔC14 para América del Sur, permitió inferir una edad de muerte que corresponde al lapso 1817-1828 AD. La fecha inferida refiere el origen de la tafocenosis a la "Gran Seca", uno de los eventos de sequía más importantes de la región pampeana, sobre el que se tiene registro histórico. Es éste el primer registro paleontológico de un evento de mortandad masiva de ganado relacionado con las frecuentes sequías verificada en la región pampeana durante los siglos XVIII y XIX.A taphocenosis composed of a great number of specimens of Equus caballus, Bos taurus and Ovis aries, without age selection, was analyzed. A radiocarbon date from the bone collagen of a humerus of Bos taurus was obtained; the date is "modern" (between AD 1750 and 1950. However, the 14C concentration of the specimen and its comparison with the South America concentration curve enabled the date to be narrowed down. The inferred date corresponds to the period AD 1817-1828, and suggests that the origin of the taphocenosis is related to the "Gran Seca" ("Great Drought", one of the most important drought events in the Pampeana Region for which there are historical records. This is the first paleontological record of an event of mass death of livestock related to the frequent droughts that affected the Pampean Region during the seventeenth and eighteenth centuries.

  11. Cretaceous plutonic rocks in the Donner Lake-Cisco Grove area, northern Sierra Nevada, California

    Science.gov (United States)

    Kulow, Matthew J.; Hanson, Richard E.; Girty, Gary H.; Girty, Melissa S.; Harwood, David S.

    1998-01-01

    The northernmost occurrences of extensive, glaciated exposures of the Sierra Nevada batholith occur in the Donner Lake-Cisco Grove area of the northern Sierra Nevada. The plutonic rocks in this area, which are termed here the Castle Valley plutonic assemblage, crop out over an area of 225 km2 and for the most part are shown as a single undifferentiated mass on previously published geological maps. In the present work, the plutonic assemblage is divided into eight separate intrusive units or lithodemes, two of which each consist of two separate plutons. Compositions are dominantly granodiorite and tonalite, but diorite and granite form small plutons in places. Spectacular examples of comb layering and orbicular texture occur in the diorites. U-Pb zircon ages have been obtained for all but one of the main units and range from ~120 to 114 Ma, indicating that the entire assemblage was emplaced in a narrow time frame in the Early Cretaceous. This is consistent with abundant field evidence that many of the individual phases were intruded penecontemporaneously. The timing of emplacement correlates with onset of major Cretaceous plutonism in the main part of the Sierra Nevada batholith farther south. The emplacement ages also are similar to isotopic ages for gold-quartz mineralization in the Sierran foothills west of the study area, suggesting a direct genetic relationship between the voluminous Early Cretaceous plutonism and hydrothermal gold mineralization.

  12. Espacio urbano, espacio del consumo en las crónicas norteamericanas de Justo Sierra

    Directory of Open Access Journals (Sweden)

    Cristina Beatriz Fernández

    2011-01-01

    Full Text Available El objetivo de este trabajo es analizar las crónicas de viaje de Justo Sierra, escritas en ocasión de su visita a los Estados Unidos a finales del siglo XIX, con énfasis en las dedicadas a la ciudad de Nueva York. En ellas, centramos nuestra atención en el registro textual de fenómenos relacionados con la forma en que Sierra percibe la modernidad norteamericana, especialmente significativa en lo que hace a la relación entre economía y sociedad. Por ello, atendemos particularmente la configuración del espacio urbano como un escenario del consumo, y procuramos demostrar cómo la constitución física y simbólica de las ciudades muestra rasgos de parentesco con esos eventos típicos de la época que fueron las ferias y exposiciones, las cuales también son objeto de la prosa de Sierra.

  13. Changes in precipitating snow chemistry with location and elevation in the California Sierra Nevada

    Science.gov (United States)

    Creamean, Jessie M.; Axson, Jessica L.; Bondy, Amy L.; Craig, Rebecca L.; May, Nathaniel W.; Shen, Hongru; Weber, Michael H.; Pratt, Kerri A.; Ault, Andrew P.

    2016-06-01

    Orographic snowfall in the Sierra Nevada Mountains is an important source of water for California and can vary significantly on an annual basis. The microphysical properties of orographic clouds and subsequent formation of precipitation are impacted, in part, by aerosols of varying size, number, and chemical composition, which are incorporated into clouds formed along the Sierra barrier. Herein, the physicochemical properties and sources of insoluble residues and soluble ions found in precipitation samples were explored for three sites of variable elevation in the Sierra Nevada during the 2012-2013 winter season. Residues were characterized using a suite of physicochemical techniques to determine the size-resolved number concentrations and associated chemical composition. A transition in the aerosol sources that served as cloud seeds or were scavenged in-cloud and below-cloud was observed as a function of location and elevation. Anthropogenic influence from the Central Valley was dominant at the two lowest elevation sites (1900 and 2200 m above mean sea level (AMSL)), whereas long-range transported mineral dust was a larger contributor at the highest elevation site where cleaner conditions were observed (2600 m AMSL). The residues and soluble ions observed provide insight into how multiple aerosol sources can impact cloud and precipitation formation processes, even over relatively small spatial scales. The transition with increasing elevation to aerosols that serve as ice nucleating particles may impact the properties and extent of snowfall in remote mountain regions where snowpack provides a vital supply of water.

  14. Hallazgo de granitoides fuertemente peraluminosos en la sierra de Famatina, orógeno famatiniano

    Directory of Open Access Journals (Sweden)

    J.A. Dahlquist

    2005-06-01

    Full Text Available La unidad fuertemente peraluminosa Cerro Toro, formada por rocas graníticas con cordierita y granate, constituye uno de los afloramientos más occidentales de la sierra de Famatina. Estudios combinados de petrología, geoquímica de roca total y química mineral indican que el magma primordial de esta unidad fue derivada a partir de la fusión parcial de metasedimentos en condiciones de alta temperatura (762°C y presión media (4,1 Kb. Las elevadas relaciones de Rb/Sr, Rb/Ba y las bajas relaciones de CaO/NaO2 (< 0,34 sugieren que el magma primordial se derivó de una fuente metasedimentaria de composición psamopelítica rica en plagioclasa (metagrauvacas, apoyando la anatexis de sedimentos provenientes de una plataforma continental inmadura. Este trabajo constituye el primer reporte de rocas graníticas fuertemente peraluminosas en la sierra de Famatina. Estas rocas graníticas son muy similares a las rocas de la unidad peraluminosa Granito Tuaní aflorante en la sierra de Chepes, la cual es formada por típicos granitoides famatinianos, sugiriendo que similares procesos petrogenéticos ocurrieron en ambas regiones del arco magmático desarrollado durante el Ordovícico Inferior a Medio.

  15. Interactions among wildland fires in a long-established Sierra Nevada natural fire area

    Science.gov (United States)

    Collins, B.M.; Miller, J.D.; Thode, A.E.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

    2009-01-01

    We investigate interactions between successive naturally occurring fires, and assess to what extent the environments in which fires burn influence these interactions. Using mapped fire perimeters and satellite-based estimates of post-fire effects (referred to hereafter as fire severity) for 19 fires burning relatively freely over a 31-year period, we demonstrate that fire as a landscape process can exhibit self-limiting characteristics in an upper elevation Sierra Nevada mixed conifer forest. We use the term 'self-limiting' to refer to recurring fire as a process over time (that is, fire regime) consuming fuel and ultimately constraining the spatial extent and lessening fire-induced effects of subsequent fires. When the amount of time between successive adjacent fires is under 9 years, and when fire weather is not extreme (burning index extremely low. Analysis of fire severity data by 10-year periods revealed a fair degree of stability in the proportion of area burned among fire severity classes (unchanged, low, moderate, high). This is in contrast to a recent study demonstrating increasing high-severity burning throughout the Sierra Nevada from 1984 to 2006, which suggests freely burning fires over time in upper elevation Sierra Nevada mixed conifer forests can regulate fire-induced effects across the landscape. This information can help managers better anticipate short- and long-term effects of allowing naturally ignited fires to burn, and ultimately, improve their ability to implement Wildland Fire Use programs in similar forest types. ?? 2008 Springer Science+Business Media, LLC.

  16. 10Be exposure dating of Holocene moraines in the Sierra Nevada, California

    Science.gov (United States)

    Hidy, Alan; Zimmerman, Susan; Finkel, Robert; Schaefer, Jeorg; Clark, Douglas

    2016-04-01

    Constraint on the extent and timing of Holocene glaciations is critical to addressing standing hypotheses that ascribe climatic fluctuations to changes in atmospheric and oceanic circulation patterns, or anthropogenic forcing. In the terrestrial record, such constraint typically relies on chronologies obtained from 10Be exposure dating of moraine deposits. However, the short exposure time of Holocene moraines, particularly those formed during the Little Ice Age (LIA), makes obtaining precise chronologies extremely challenging. To date, only a handful of LIA deposits in two locations (New Zealand and the Swiss Alps) have been successfully dated with 10Be. Here, we report new 10Be exposure ages from LIA and Neoglacial moraines from multiple sites in the Sierra Nevada (Lyell, Maclure, and Palisade glaciers). The Sierran LIA record will be compared to those from New Zealand and the Swiss Alps to test whether LIA deglaciation was globally synchronous. This result would support the contention that the LIA was terminated by anthropogenically-driven warming. Chronology from the neoglacial deposits will be used to test whether the timing of the return to glacial conditions in the Sierras correlates to a southward shift in the Intertropical Convergence Zone, which has been hypothesized to increase El Nino-like conditions in the Pacific Ocean. This record should be ideal for testing this hypothesis since precipitation in the Sierras is highly sensitive to El Nino conditions.

  17. Containing Ebola: A Test for Post-Conflict Security Sector Reform in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Cathy Haenlein

    2015-07-01

    Full Text Available Ebola has provided the greatest test of the Sierra Leonean security sector – and, in turn, of the UK-led reforms of the past ten-to-fifteen years. The performance of the country's security forces at the height of the crisis suggests that there are sound structures in place; however, Ebola has shown that the Government of Sierra Leone's national security architecture still lacks maturity in responding to such a scenario. Drawing on first-hand interviews with advisers on the ground, this article explores the Sierra Leone government’s response to the Ebola crisis and the performance of the security sector so far, within the wider context of UK-led security-sector reform (SSR since the end of the civil war. In doing so, it highlights a number of lessons to have emerged from the crisis, exploring what these reveal about the nature of the reforms implemented since the end of the country's civil war. In turn, it explores what these suggest for future SSR, which continues to be a core component of the UK’s approach to development and overseas capacity-building.

  18. El megadeslizamiento del cerro Uritorco, ladera occidental de la Sierra chica de Córdoba

    Directory of Open Access Journals (Sweden)

    Claudio A Carignano

    2014-03-01

    Full Text Available En el extremo norte de la Sierra Chica de Córdoba, sobre el flanco oeste del cerro Uritorco (1.949 m s.n.m., se ha identificado un megadeslizamiento (30°49'55,46"S y 64°29'50,31"O. Los materiales movilizados del frente del escarpe de la falla Sierra Chica, han cubierto parcialmente el granito de Capilla del Monte y los abanicos aluviales pleistocenos del piedemonte. El lóbulo y bloques rotados del deslizamiento conforman un alto topográfico que oficia de límite entre los valles de Punilla (al sur y de Charbonier (al noroeste. Mediante técnicas de procesamiento e interpretación de imágenes satelitales multiespectrales de media (Landsat-ETM y muy alta resolución (GeoEye-1, análisis digital del terreno a partir de modelos de elevación (SRTM y Aster-GDEM y el correspondiente control de campo, se ha delimitado y caracterizado esta megageoforma nunca antes advertida. Dada la elevada sismicidad actual e histórica de la zona y los indicios morfotectónicos que señalan como activas a las fallas Sierra Chica y Pajarillo-Copacabana-Masa, se estima que este deslizamiento posiblemente fue gatillado por un evento sísmico, acontecido en alguna de esas estructuras. Tanto el depósito del deslizamiento como su cicatriz de despegue presentan un significativo grado de erosión hídrica. Por análisis comparativos con otros deslizamientos ya datados y de características similares, situados en el escarpe occidental de las Sierras de San Luis, se le asigna una edad pleistocena medio-tardía. Por su volumen y características (2,1 x109 m³ se estableció que se trata de un megadeslizamiento único en las Sierras de Córdoba y constituye uno de los deslizamientos de mayor tamaño entre los registrados hasta el presente en Argentina.

  19. Spatiotemporal patterns of fault slip rates across the Central Sierra Nevada frontal fault zone

    Science.gov (United States)

    Rood, Dylan H.; Burbank, Douglas W.; Finkel, Robert C.

    2011-01-01

    Patterns in fault slip rates through time and space are examined across the transition from the Sierra Nevada to the Eastern California Shear Zone-Walker Lane belt. At each of four sites along the eastern Sierra Nevada frontal fault zone between 38 and 39° N latitude, geomorphic markers, such as glacial moraines and outwash terraces, are displaced by a suite of range-front normal faults. Using geomorphic mapping, surveying, and 10Be surface exposure dating, mean fault slip rates are defined, and by utilizing markers of different ages (generally, ~ 20 ka and ~ 150 ka), rates through time and interactions among multiple faults are examined over 10 4-10 5 year timescales. At each site for which data are available for the last ~ 150 ky, mean slip rates across the Sierra Nevada frontal fault zone have probably not varied by more than a factor of two over time spans equal to half of the total time interval (~ 20 ky and ~ 150 ky timescales): 0.3 ± 0.1 mm year - 1 (mode and 95% CI) at both Buckeye Creek in the Bridgeport basin and Sonora Junction; and 0.4 + 0.3/-0.1 mm year - 1 along the West Fork of the Carson River at Woodfords. Data permit rates that are relatively constant over the time scales examined. In contrast, slip rates are highly variable in space over the last ~ 20 ky. Slip rates decrease by a factor of 3-5 northward over a distance of ~ 20 km between the northern Mono Basin (1.3 + 0.6/-0.3 mm year - 1 at Lundy Canyon site) to the Bridgeport Basin (0.3 ± 0.1 mm year - 1 ). The 3-fold decrease in the slip rate on the Sierra Nevada frontal fault zone northward from Mono Basin is indicative of a change in the character of faulting north of the Mina Deflection as extension is transferred eastward onto normal faults between the Sierra Nevada and Walker Lane belt. A compilation of regional deformation rates reveals that the spatial pattern of extension rates changes along strike of the Eastern California Shear Zone-Walker Lane belt. South of the Mina Deflection

  20. Evaluación de una metodología de pronóstico estadístico para la condición hídrica del suelo en la región pampeana argentina Evaluation of a statistical forecasting method for the soil water condition in the Argentinean pampas region

    OpenAIRE

    Serio, L.; Martin, P.; Murphy, G.

    2010-01-01

    Una de las herramientas disponibles para el monitoreo de sequías y excesos de humedad en el suelo es el índice estandarizado de precipitación (SPI). Desde hace 3 años se ha implementado una metodología de monitoreo y predicción estadística mensual del SPI en la región pampeana de la Argentina. El objetivo de este trabajo fue hacer una evaluación de esos pronósticos. En primer lugar, se describen la metodología de cálculo del SPI y los aspectos considerados para emitir los pronósticos. Luego s...

  1. Patterns of endemism along an elevation gradient in Sierra Nevada (Spain and Lefka Ori (Crete, Greece

    Directory of Open Access Journals (Sweden)

    Fernández-Calzado, R.

    2013-12-01

    Full Text Available Aim: High mountains in the Mediterranean region of Europe are particularly rich in endemic vascular plants. We aimed to compare the altitudinal patterns of vascular plant species richness and the proportion of endemic species in two Mediterranean region: Lefka Ori on the island of Crete (Greece and Sierra Nevada on the Iberian peninsula. Location: Sierra Nevada, Granada (Spain; Lefka Ori, Crete (Greece. Methods: Data from standardised permanent plots settings on summit sites (comprising eight plot sectors, covering the upeermost 10 altitudinal metres of different elevations were used (GLORIA Multi-Summit approach; www.gloria.ac.at. Species numbers, rates of endemic species, and soils temperature were compared by means of ANCOVA and linear regression. Results: The two regions, though climatically similar, showed strikingly different patterns: In Sierra Nevada, the proportion of endemic vascular plants (species restricted to Sierra Nevada showed a stepwise increase from the lowest to the highest summit. In contrast, the proportion of endemic species restricted to Crete was not significantly different between the four summits in Lefka Ori. In both regions the observed trends were largely consistent with the altitudinal distribution of the endemic species obtained from standard floras. Main conclusions: The geographic positions of the two regions, i.e. island versus mainland and the higher elevation of Sierra Nevada are suggested to be the primary causes of the observed differences. The high degree of endemism in the cold environments of Mediterranean mountains’ upper bioclimatic zones indicates a pronounced vulnerability to the impacts of climate change. A continued and intensified species monitoring in the mountains around the Mediterranean basin, therefore, should be considered as a priority research task.Objetivo: Las zonas de alta montaña en la región mediterránea europea son particularmente ricas en plantas vasculares end

  2. Petrología del plutón La Florida, sierra de San Luis Petrology of the La Florida stock, Sierra de San Luis

    Directory of Open Access Journals (Sweden)

    E. Carol

    2007-09-01

    Full Text Available El plutón La Florida se localiza en la parte central de la Sierra de San Luis y se aloja en metasedimentitas regionales de grado medio pertenecientes al grupo micaesquistos derivadas de subgrauvacas y areniscas. Es de morfología semicircular, ligeramente elongado en dirección oblicua a la foliación regional, la cual acompaña la forma del plutón en el contacto. Su composición es monzogranítica y marcadamente peraluminoso, y está compuesto por cuarzo, microclino, plagioclasa, muscovita, biotita y granate. El estudio detallado ha permitido establecer que el contenido de biotita de los monzogranitos disminuye hacia los bordes del cuerpo en tanto que la muscovita, generalmente porfiroblástica, aumenta, lo cual conduce a variaciones notables del índice de color de las rocas. Además, se registra una abundante pegmatización que forma tanto diques como cuerpos irregulares en el borde del intrusivo y también en las rocas de caja adyacentes al contacto. Esta zonación sería resultado del incremento de fluidos acuosos durante la etapa tardío magmática, que causaron reacciones subsólidas en la mineralogía ortomagmática. El magma está relacionado con el proceso subductivo desarrollado durante la orogenia famatiniana, muestra afinidad con fundidos sin-colisionales y un tren evolutivo compatible con magmas de tipo S. El plutón de La Florida exhibe algunas diferencias geológicas, petrográficas y composionales con otros granitoides sin-cinemáticos de la sierra de San Luis, encontrándose algunas similitudes solamente con rocas del cordón de El Realito.La Florida pluton is located in the central part of the Sierra de San Luis. It is a nearly semicircular-shape intrusion, slightly elongated perpendicularly to the main NNE-SSW country rocks foliation, which deforms at the pluton margins. The body is emplaced in medium-grade metamorphosed subgreywakes and sandstones-derived rocks of the Micaschist Group. Intrusive rocks are mostly greyish

  3. Cambio agrario y nueva ruralidad: Caleidoscopio de la expansión sojera en la región pampeana Agrarian change and new rurality: Kaleidoscope of soya expansion in the Pampa region

    Directory of Open Access Journals (Sweden)

    Carla Gras

    2012-06-01

    Full Text Available En las últimas décadas, y en el marco de las tesis sobre la configuración de nuevas ruralidades, los pueblos y pequeñas localidades han vuelto a concitar la atención de las ciencias sociales. Lo rural se define como un espacio crecientemente polisémico, donde se redefinen los antes coincidentes contornos entre lo rural y lo agrícola. Nuestro interés en los pueblos rurales de la región pampeana parte de esa constatación y pretende, al mismo tiempo indagar en las implicancias de las transformaciones que se derivan de las profundas mutaciones operadas en el modelo de producción agropecuaria, las cuales involucraron, entre otros aspectos, una dinámica de "ganadores y "perdedores". La existencia de población que vive en pueblos y localidades rurales pero que no tiene relación laboral con el sector agropecuario, y de un mundo agrario profundamente transformado son los dos elementos cuyos reflejos, en los modos de configurar estos territorios nos interesa comprender. Nos interesa explorar cómo esta suerte de diferenciación entre "ganadores" y "perdedores" se expresó en las posiciones detentadas por los productores en las comunidades locales, tanto en lo que refiere a su lugar en la población y en la economía. Exploramos las diferenciaciones socioculturales que se generan y las tensiones y complejidades que adquiere la integración social en un mismo territorio, lejos de aquella idea de la comunidad que la define por la similitud u homogeneidad relativa de sus componentes, y por su estabilidad.In the last decades, and in the framework of the thesis on the configuration of a new rurality, villages and small towns have drawn the attention of the social sciences. Rurality is defined as increasingly polysemic, where the previous boundaries between rurality and agriculture have redefined. Our interest in the rural villages of the Pampa region stands on this understanding, and introduces another key process related to the deep changes

  4. Una aproximación bioarqueológica al estudio del poblamiento prehispánico tardío del Sudeste de la Región Pampeana

    Directory of Open Access Journals (Sweden)

    Gustavo Barrientos

    2001-12-01

    Full Text Available El objetivo de este trabajo es presentar, comparar y discutir la información bioarqueológica disponible para las poblaciones humanas del Holoceno tardío del Sudeste de la Región Pampeana (estructura regional del registro, indicadores óseos y dentales de salud, nutrición y dieta y variabilidad morfológica inter e intramuestral, con el fin de formular un modelo del poblamiento del área durante este período. La evidencia bioarqueológica sugiere que durante el Holoceno tardío pudieron haberse dado en el área condiciones que condujeron a una reducción de la movilidad, a una probable ampliación de la dieta, a una intensificación en el uso de recursos de bajo retorno y a cambios en las relaciones sociales y ecológicas de las poblaciones humanas respecto a anteriores momentos del Holoceno. Estos cambios pueden ser explicados como el resultado de una expansión demográfica y geográfica y de la ocupación efectiva del espacio regional posterior a una probable retracción poblacional ocurrida a mediados del Holoceno medio. Estos procesos se discuten a través de la aplicación de ciertos principios derivados del emergente campo de la geografía evolutiva (Lahr y Foley 1998 y de la ecología evolutiva (modelo Travelers-Processors; Bettinger y Baumhoff 1982.The aims of this paper are to present, compare and discuss the growing bioarchaeological database available for the late human populations from the southeastern Pampean Region in Argentina. These data are related to the regional structure of the bioarchaeological record, the sample distribution of bone and dental indicators of health status, nutrition and diet, and cranial and postcranial morphological diversity. All the bioarchaeological evidence suggests the existence during the Late Holocene of conditions promoting a reduction in group mobility, a broadening of diet spectrum, increased emphasis in processing of some relatively low return vegetal resources, such as seeds and sheaths

  5. Patrones biogeográficos de la avifauna de la Sierra Madre del Sur Biogeographic patterns of the avifauna of the Sierra Madre del Sur

    Directory of Open Access Journals (Sweden)

    Epifanio Blancas-Calva

    2010-08-01

    Full Text Available Analizamos la avifauna de 26 subcuencas de la provincia biótica de la Sierra Madre del Sur y sus relaciones biogeográficas utilizando el análisis de parsimonia de endemismos (PAE. A partir de información distributional de las especies obtenida de la base de datos del Atlas de las aves de México y de la literatura disponible, construimos una matriz de datos para 26 subcuencas y 437 especies. Se obtuvo un cladograma que sugiere la existencia de 3 grupos de subcuencas: el primero agrupa subcuencas de climas áridos, ubicadas geográficamente de norte a sureste en el estado de Oaxaca; el segundo, otras subcuencas de ambientes climáticos subhúmedos, y el tercero, las restantes subcuencas de ambientes climáticos húmedos de mayor complejidad ambiental.We analyzed the avifauna of 26 sub-basins of the Sierra Madre del Sur biotic province and their biogeographical relationships applying a parsimony analysis of endemicity (PAE. Based on the distributional information of the species obtained from the Atlas de las aves de México and published literature, we built a data matrix for 26 sub-basins and 437 species. The single cladogram obtained suggests the existence of three groups of sub-basins:the first with 5 sub-basins from arid environments, geographically located in north-southeastern Oaxaca; the second with another 5 sub-basins form subhumid environments; and the third one with the remaining sub-basins, from humid and environmentally more complex habitats.

  6. Post-orogenic evolution of the Sierras Septentrionales and the Sierras Australes and links to the evolution of the eastern Argentina South Atlantic passive continental margin constrained by low temperature thermochronometry and 2D thermokinematic modeling

    Science.gov (United States)

    Kollenz, Sebastian; Glasmacher, Ulrich Anton; Rossello, Eduardo A.

    2013-04-01

    The eastern Argentina South Atlantic passive continental margin is distinguished by a very flat topography. Out of the so called Pampean flat two mountain ranges are arising. These mountain ranges, the Sierras Australes and the Sierras Septentrionales, are located in the State of Buenos Aires south of the capital Buenos Aires. North of the Sierras Septentrionales the Salado basin is located. The Sierras Septentrionales and the Sierras Australes are also divided by a smaller intracratonic basin. Further in the South the Colorado basin is located. The Sierras Australes is a variscian fold belt originated by strong phases of metamorphosis, but till now it is unclear by how many tectonic phases the area was influenced (Tomezzoli & Vilas, 1999). It consists of Proterozoic to Paleozoic rocks. The Sierras Septentrionales consists mainly of Precambrian crystalline rocks. The Precambrian sequences are overlain by younger Sediments (Cingolani, 2010). The aim is to understand the long-term landscape evolution of the area by quantifiying erosion- and exhumation-rates and by dating ancient rock-uplift-events. Another goal is to find out how the opening of the south atlantic took effect on this region. To fulfill this goal, thermochronological techniques, such as fission-track dating and (U-Th-Sm)/He dating has been applied to samples from the region. Because there was no low-temperature thermochronology done in this area, both techniques were applied on apatites and zircons. Furthermore, numerical modeling of the cooling history has provided the data base for the quantification of the exhumation rates. The first data-set shows clusters of different ages which can be linked to tectonic activities during late Paleozoic times. Also the thermokinematic modeling is leading to new insights of the evolution of both mountain ranges. References: Renata Nela Tomezzoli and Juan Francisco Vilas (1999): Palaeomagnetic constraints on the age of deformation of the Sierras Australes thrust and

  7. Effect of previous chilling storage on quality loss in frozen (–20 °C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

    OpenAIRE

    Herlinda Soto-Valdez; Josafat Marina Ezquerra-Brauer; Enrique Márquez-Ríos; Wilfrido Torres-Arreola

    2015-01-01

    Rancidity development during frozen storage (–20 °C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric ...

  8. Public and Occupational Exposure to Naturally Occuring Radioactive Materials from Mining and Mineral Processing in Sierra Leone

    International Nuclear Information System (INIS)

    Mining has been identified as one of the potential sources of exposure to naturally occurring radioactive materials (NORM). However, mining companies are not being regulated for NORM in Sierra Leone until when recently the Protection from radiation Act 2001 was revised and repeated as recommended by the International Atomic Energy Agency’s Integrated Regulatory Review Service mission in Sierra Leone. Now Sierra Leone can be proud of one of the best laws in radiation protection that is the Nuclear Safety and radiation protection act, 2012. This law gave enforcement powers to the regulatory authority and a wider scope of control not excluding NORMS. Whilst the developed countries have identified NORM as potential problems and measures are being taken to address the issues, very little is being done in the developing countries. (author)

  9. Anomalías del campo gravitatorio y magnético terrestre en la sierra de Socoscora, provincia de San Luis

    Directory of Open Access Journals (Sweden)

    J Kostadinoff

    2003-12-01

    Full Text Available La sierra de Socoscora se ubica en forma meridiana y se manifiesta como un escalón al noroeste de la Sierra Grande de San Luis. En la sierra de Socoscora las rocas del basamento están representadas por metamorfitas de alto grado con escasos afloramientos de metabasitas. Las mediciones del campo gravitatorio y magnético indican la presencia de un volumen mayor de estas rocas en su subsuelo. Los excesos de masa en esta sierra se hallan definidas por anomalías gravimétricas de Bouguer (residuales positivas similares a las encontradas en la Sierra Grande de San Luis. La magnetometría indica, a partir de las respuestas positivas, la existencia de rocas máficas con concentraciones anómalas de minerales magnéticos.

  10. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Rodriguez-Pineda; P. Goodell; P.F. Dobson; J. Walton; R. Oliver; De La Garza; S. Harder

    2005-07-11

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area.

  11. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area

  12. The Impact of the West Africa Ebola Outbreak on Obstetric Health Care in Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Kim J Brolin Ribacke

    Full Text Available As Sierra Leone celebrates the end of the Ebola Virus Disease (EVD outbreak, we can begin to fully grasp its impact on already weak health systems. The EVD outbreak in West Africa forced many hospitals to close down or reduce their activity, either to prevent nosocomial transmission or because of staff shortages. The aim of this study is to assess the potential impact of EVD on nationwide access to obstetric care in Sierra Leone.Community health officers collected weekly data between January 2014-May 2015 on in-hospital deliveries and caesarean sections (C-sections from all open facilities (public, private for-profit and private non-profit sectors offering emergency obstetrics in Sierra Leone. This was compared to official data of EVD cases per district. Logistic and Poisson regression analyses were used to compute risk and rate estimates. Nationwide, the number of in-hospital deliveries and C-sections decreased by over 20% during the EVD outbreak. The decline occurred early on in the EVD outbreak and was mainly attributable to the closing of private not-for-profit hospitals rather than government facilities. Due to difficulties in collecting data in the midst of an epidemic, limitations of this study include some missing data points.Both the number of in-hospital deliveries and C-sections substantially declined shortly after the onset of the EVD outbreak. Since access to emergency obstetric care, like C-sections, is associated with decreased maternal mortality, many women are likely to have died due to the reduced access to appropriate care during childbirth. Future research on indirect health effects of health system breakdown should ideally be nationwide and continue also into the recovery phase. It is also important to understand the mechanisms behind the deterioration so that important health services can be reestablished.

  13. Representación de las propiedades de las aguas mineromedicinales de la Sierra del Rosario.

    Directory of Open Access Journals (Sweden)

    Margaret Suárez Muñoz

    2005-01-01

    Full Text Available La representación gráfica y el uso de Sistemas de Información Geográfica (SIG, ha permitido que los datos de diferentes recursos de aguas minerales de la Sierra del Rosario sean mostrados de forma resumida y que ofrezcan mayor claridad para usuarios experimentados o no, que precisen este tipo de información. En este trabajo con los datos de diferentes campañas de muestro realizadas en la Sierra del Rosario, han sido representadas, según su distribución geográfica algunas de las propiedades físico-químicas, con repercusión directa en las propiedades terapéuticas, de éstas aguas. El trabajo tiene como objetivo mostrar parte de la labor que se ha realizado en la Sierra del Rosario, completando la información existente en esta zona tan rica en recursos termales y procesándola para realizar un atlas de los recursos de la zona y con posterioridad del resto de los recursos del país. En su elaboración se utilizaron diferentes programas hidrogeoquímicos como el SACAN y el HIDROGEOQUIM, paquete de Microsoft Office 98 para Windows y el MAPINFO 6.5 como Sistema de Información Geográfica (SIG. El resultado final muestra diferentes mapas con representaciones de las propiedades de estas aguas, que fueron agrupadas según sus características, para brindar una información gráfica muy útil para la posterior utilización las mismas.

  14. Support services for survivors of ebola virus disease - Sierra Leone, 2014.

    Science.gov (United States)

    Lee-Kwan, Seung Hee; DeLuca, Nickolas; Adams, Monica; Dalling, Matthew; Drevlow, Elizabeth; Gassama, Gladys; Davies, Tina

    2014-12-19

    As of December 6, 2014, Sierra Leone reported 6,317 laboratory-confirmed cases of Ebola virus disease (Ebola), the highest number of reported cases in the current West Africa epidemic. The Sierra Leone Ministry of Health and Sanitation reported that as of December 6, 2014, there were 1,181 persons who had survived and were discharged. Survivors from previous Ebola outbreaks have reported major barriers to resuming normal lives after release from treatment, such as emotional distress, health issues, loss of possessions, and difficulty regaining their livelihoods. In August 2014, a knowledge, attitude, and practice survey regarding the Ebola outbreak in Sierra Leone, administered by a consortium of partners that included the Ministry of Health and Sanitation, UNICEF, CDC, and a local nongovernmental organization, Focus 1000, found that 96% of the general population respondents reported some discriminatory attitude towards persons with suspected or known Ebola. Access to increased psychosocial support, provision of goods, and family and community reunification programs might reduce these barriers. Survivors also have unique potential to contribute to the Ebola response, particularly because survivors might have some immunity to the same virus strain. In previous outbreaks, survivors served as burial team members, contact tracers, and community educators promoting messages that seeking treatment improves the chances for survival and that persons who survived Ebola can help their communities. As caregivers in Ebola treatment units, survivors have encouraged patients to stay hydrated and eat and inspired them to believe that they, too, can survive. Survivors regaining livelihood through participation in the response might offset the stigma associated with Ebola. PMID:25522090

  15. Asintóticas para frecuencias altas de ondas atrapadas por sierras submarinas

    OpenAIRE

    Marin Ramírez, Ana Magnolia

    2012-01-01

    Desde el primer trabajo de Ursell [1] en 1951, se conoce que en el caso de sierras submarinas ocurre el fenómeno de ondas guiadas para ondas de agua. Jones, en el período inicial del desarrollo del anáisis funcional moderno, obtuvo el primer resultado matemático concerniente al problema que tratamos aquí Usando análisis espectral para el operador de Laplace en dominios no acotados con varias condiciones de frontera, mostró los teoremas de comparación, de los cuales se obtienen resultado...

  16. Integration of the Watcher Telescope into the Sierra Stars Observatory Network – Lessons Learned for GLORIA

    Directory of Open Access Journals (Sweden)

    Martin Topinka

    2013-01-01

    Full Text Available The UCD Watcher robotic telescope is planning to participate in the Sierra Stars Observatory Network (SSON, a US-based organisation that provides astronomical images upon request to subscribing users, who are typically either amateurs or university/college students. Implementing the tasks required for the integration of Watcher to SSON, such as remote scheduling, file transfer, image quality validation and the provision of meteorological information, have provided useful experience for the GLORIA project. It has also become apparent that managing user expectations will be important for GLORIA.

  17. Uso tradicional de vertebrados silvestres en la Sierra Nanchititla, México

    OpenAIRE

    Monroy Vilchis, Octavio; Cabrera García, Leonardo; Suárez, Pedro; Zarco González, Martha Mariela; Rodríguez Soto, Clarita; Urios, Vicente

    2008-01-01

    Los pobladores nativos de México se han caracterizado por poseer conocimiento tradicional sobre las especies de flora y fauna de los ambientes donde habitan, así como por sus prácticas de aprovechamiento. En este estudio se documentó el uso tradicional de vertebrados silvestres por parte de los habitantes de las trece comunidades de mayor influencia de la Reserva Natural Sierra Nanchititla (RNSN), se examinó su disponibilidad como recurso en esta área protegida y se analizó la correlación ent...

  18. USO TRADICIONAL DE VERTEBRADOS SILVESTRES EN LA SIERRA NANCHITITLA, MÉXICO

    OpenAIRE

    Octavio Monroy-Vilchis; Leonardo Cabrera; Pedro Suárez; Martha Mariela Zarco-González; Clarita Rodríguez-Soto; Vicente Urios

    2008-01-01

    Los pobladores nativos de México se han caracterizado por poseer conocimiento tradicional sobre las especies de flora y fauna de los ambientes donde habitan, así como por sus prácticas de aprovechamiento. En este estudio se documentó el uso tradicional de vertebrados silvestres por parte de los habitantes de las trece comunidades de mayor influencia de la Reserva Natural Sierra Nanchititla (RNSN), se examinó su disponibilidad como recurso en esta área protegida y se analizó la correlación ent...

  19. La dinámica demográfica reciente en la Sierra Morena Cordobesa

    OpenAIRE

    Luque Revuelto, Ricardo Manuel

    2012-01-01

    La Sierra de Córdoba constituye un ámbito espacial diferenciado en la provincia y en el conjunto de Andalucía. Los habitantes de los espacios mariánicos son el elemento básico en la ocupación de ese territorio, caracterizado por un marcado carácter rural. El estudio de la dinámica demográfi ca reciente de los espacios mariánicos y las diferencias regionales que presenta constituye el objetivo principal del presente trabajo.

  20. Estructura de los encinares de la sierra de Santa Rosa, Guanajuato, México

    OpenAIRE

    Juan Martínez-Cruz; Oswaldo Téllez Valdés; Guillermo Ibarra-Manríquez

    2009-01-01

    Se describe la estructura de 4 asociaciones de encinares en el oriente de la sierra de Santa Rosa, Guanajuato, con el método de cuadrantes al punto central (21 transectos), donde se contabilizaron 2 320 individuos arbóreos y arbustivos, que incluyen 36 especies, 22 géneros y 15 familias. La asociación Quercus potosina-Q. castanea (QPC) registró la mayor riqueza (29 especies) y el menor número de individuos por ha-1 (650). Por el contrario, la asociación de Q. laurina-Q. rugosa (QLR) presentó ...

  1. Proyecto para la recuperación de suelos de la Sierra Minera.

    OpenAIRE

    Zanuzzi, Andrea

    2009-01-01

    Investigadores del grupo Gestión, Aprovechamiento y Recuperación de Suelos y Aguas han conseguido un método para reducir en gran medida la contaminación por metales pesados de zonas de la Sierra Minera de Cartagena-La Unión. Se trata de un sistema basado en la aplicación de residuos (purines, lodos de depuradora y lodo de corte de las canteras de mármol). Los resultados son fruto de dos proyectos de investigación, financiados por el Plan Nacional PETRI y PROFIT del Ministerio de Educación y C...

  2. High Hopes, Grim Reality: Reintegration and the Education of Former Child Soldiers in Sierra Leone

    OpenAIRE

    Betancourt, Theresa Stichick; Simmons, Stephanie; Borisova, Ivelina; Brewer, Stephanie E.; Iweala, Uzo; de la Soudière, Marie

    2008-01-01

    Civil war broke out in Sierra Leone in 1991 and lasted more than a decade. During the conflict, both the national army and the Revolutionary United Front (RUF), a rebel group responsible for some of the worst atrocities during the conflict, abducted children from the villages they attacked and occupied. An estimated 15,000–22,000 children of all ages were taken from their families and forced to serve the military groups in a number of ways, from performing domestic chores and other military s...

  3. Gravity change from 2014 to 2015, Sierra Vista Subwatershed, Upper San Pedro Basin, Arizona

    Science.gov (United States)

    Kennedy, Jeffrey R.

    2016-09-13

    Relative-gravity data and absolute-gravity data were collected at 68 stations in the Sierra Vista Subwatershed, Upper San Pedro Basin, Arizona, in May–June 2015 for the purpose of estimating aquifer-storage change. Similar data from 2014 and a description of the survey network were published in U.S. Geological Survey Open-File Report 2015–1086. Data collection and network adjustment results are presented in this report, which is accompanied by a supporting Web Data Release (http://dx.doi.org/10.5066/F7SQ8XHX). Station positions are presented from a Global Positioning System campaign to determine station elevation.

  4. Infraestructura verde urbana: Plan Estratégico de Desarrollo Urbano de Makeni (Sierra Leona)

    OpenAIRE

    García Fernández, Natalia; Salas Ruiz, Adela

    2014-01-01

    La aportación al Plan Estratégico de Desarrollo Urbano de Makeni (Sierra Leona) desde la Infraestructura Verde pretende formalizar una estrategia de aproximación al territorio que ponga en valor la capacidad productiva de éste y permita compatibilizar la protección de las áreas de mayor valor con un desarrollo urbano y socioeconómico sostenible. La identificación de la Infraestructura Verde en el territorio no es otra cosa que la formalización de la “elección del sitio” que evidenciamos de...

  5. Tafonomía en la Sierra de Atapuerca, Burgos (España)

    OpenAIRE

    Fernández Jalvo, Yolanda

    2003-01-01

    [ES] Los yacimientos de la Sierra de Atapuerca (Gran Dolina, Penal, Galería y Sima de los Huesos) tienen un abundante contenido fósil y en ellos se han efectuado varios estudios tafonómicos. De los tres primeros yacimientos, todos ellos en la Trinchera del Ferrocarril, el objeto de estudio ha sido las asociaciones de micromamíferos. Estos estudios han proporcionado una información importante sobre los mecanismos de formación de estos yacimientos y la evolución de las distintas cavida...

  6. Meteoric isotopic gradient on the windward side of theSierra Madre Oriental area, Veracruz Mexico

    OpenAIRE

    Juan Pérez Quezadas; Alejandra Cortés Silva; Salvatore Inguaggiato; María del Rocío Salas Ortega; Juan Cervantes Pérez; Victor Michael Heilweil

    2015-01-01

    The isotopic composition ( d 18 O , d D ) of precipitation in the windward side of the Sierra Madre Oriental on the eastern flank of the Mexican Volcanic Belt was characterized along a 90 km transect from sea level up to an altitude of 4220 meters. Rain samples were collected during the rainy season (May through October) from 2007 through 2012. The Local Meteoric Water Line (LMWL), determined with linear regression of isotope results, is d D = 7.44 d 18 O + 7.3, R 2 = 0.99. Thi...

  7. Salida de campo a Montejo de la Sierra (Madrid) a mediados de septiembre de 1953

    OpenAIRE

    Valverde Gómez, José Antonio, 1926-2003

    2008-01-01

    Salida de campo a Montejo de la Sierra, en Madrid, a mediados de septiembre de 1953, de la que se anotaron observaciones sobre los siguientes anfibios: Bufo bufo (Sapo común, llamado B.vulgaris por el autor) y Rana sp. (Rana), los siguientes reptiles: Natrix maura (Culebra viperina, llamada Tropidonotus viperinus por el autor) y Psammodromus sp. (Lagartija), los siguientes mamíferos: Arvicola sapidus (Rata de agua, también llamado Ratón aguadero), Martes foina (Garduña), Plecotus sp. (Orejudo...

  8. The Ebola virus disease outbreak and the mineral sectors of Guinea, Liberia, and Sierra Leone

    Science.gov (United States)

    Bermúdez-Lugo, Omayra; Menzie, William D.

    2015-01-01

    The mineral sector plays a key role in the economies of Guinea, Liberia, and Sierra Leone. The onset of the Ebola virus disease (EVD) outbreak in early 2014, together with changes in mineral market conditions, raised questions regarding the status of mining operations and of mineral development and exploration projects in all three countries. Mineral projects were the underpinnings of World Bank short-term forecasts of increases in gross domestic product (GDP) for all three countries and were expected to be the basis of future economic growth. The significant delay or cancellation of these projects could result in a major economic setback for all three countries.

  9. Seismic evidence for crustal underplating beneath a large igneous province: The Sierra Leone Rise, equatorial Atlantic

    OpenAIRE

    Jones, E. J. W.; McMechan, G. A.; Zeng, X.

    2015-01-01

    Wide-angle seismic profiles reveal anomalously thick crust with a high-velocity (> 7.3 km s− 1) zone under the Sierra Leone Rise, a major mid-plate elevation in the Atlantic lying between the Cape Verde platform and the Cameroon Volcanic Line. A profile recorded over the crest using an ocean-bottom seismometer and surface sonobuoys shows that beneath a 3 km water layer and 1 km of sediments, the basement extends to 16–20 km below sea level. Most velocity-depth values fall outside the expected...

  10. Slippery fish, material words: the substance of subsistence in coastal Sierra Leone

    OpenAIRE

    Diggins, Jennifer

    2014-01-01

    This thesis is based on eighteen months’ fieldwork in Tissana: a bustling multi-ethnic fishing town on Sierra Leone’s southern coast. It tells the story of the successive waves of young migrants who, for several decades, have been arriving on the coast from rural areas seeking an alternative to the indentured labour conditions of a farming economy still shaped by the legacy of domestic slavery. Set against the backdrop of a rapidly changing post­‐war economy, and in an ecological context in w...

  11. Listado florístico de la Sierra de Santa Rosa, Guanajuato, México

    OpenAIRE

    Juan Martínez Cruz; Oswaldo Téllez-Valdés

    2004-01-01

    Actualmente la Sierra de Santa Rosa es una de las pocas áreas reminiscentes medianamente conservadas en Guanajuato, ya que desafortunadamente el estado se ha caracterizado por la degradación de su cubierta vegetal desde tiempos coloniales. En este estudio florístico se registran 21 taxa infraespecíficos, 496 especies, 273 géneros y 93 familias de plantas vasculares. De éstas, la familia Asteraceae tiene la mayor riqueza de especies, seguida por Poaceae y Lamiaceae. Se registraron tres especie...

  12. Alternatives for Sustainable Development and Gender Equality: A Case Study from Sierra Leone

    OpenAIRE

    Lovetta Sesay, Fatmata

    2016-01-01

    Introduction It is generally accepted that women in developing countries live in a desperate economic situation. Yet there is little consensus as to what the problem is and therefore how it needs to be tackled. In the light of the “booming industry” of development agencies, it is time to evaluate how efficient and effective their work has been especially with their gender policies, and above all to evaluate the sustainability of programmes when agencies “poll out”. Alternatives for Sierra Leo...

  13. Flora útil de los cafetales en la Sierra Norte de Puebla, México

    OpenAIRE

    Miguel Ángel Martínez; Virginia Evangelista; Francisco Basurto; Myrna Mendoza; Antonio Cruz Rivas

    2007-01-01

    Los cafetales de la Sierra Norte de Puebla son agroecosistemas variados en composición y estructura, donde se pueden encontrar especies vegetales cultivadas y silvestres, nativas e introducidas, y cuya diversidad fl orística está estrechamente ligada a las condiciones sociales, económicas y ecológicas en las que se inserta la producción del café. En la última década el cultivo de esta planta ha estado en crisis debido a los bajos precios del producto; sin embargo, los agricultores mantienen l...

  14. Media and conflict in Sierra Leone: national and international perspectives of the civil war

    Directory of Open Access Journals (Sweden)

    Valentina Bau

    2011-08-01

    Full Text Available

    The rise of the media in Sierra Leone. The media and the civil conflict. The evolution of the conflict. The Western media perspective of a "barbaric" Africa. Western media coverage of the civil war in Sierra Leone: the British example. The role of NGOs in news reporting.

    The end of the twentieth century saw an adverse escalation in armed conflict. A characteristic of this was that whilst the majority of wars that took place before the 1990s were fought between states, conflicts post 1990 progressively began to take place within countries. The doctrines of major world powers no longer seemed to determine the ideologies and objectives of warring groups and, almost as a new war strategy, combatants started to target civilians rather than fighting sections in order to achieve their objectives. Atrocities began to be the statements that publicised political positions. In countries that were rich in natural resources, such as diamonds, the political goals of wars were often linked to the complex logics of resource appropriation (Bangura, 2004.
    Rather than providing an account of the events that shaped the unfolding of the civil war in Sierra Leone, this paper focuses on the analysis of the role that the media played in elaborating the perception of those events, both at a national and international level. A theoretical examination of the impact of the conflict’s media coverage - which has been explored and reviewed by authors such as Khan (1998 and Shaw (2006 - is conducted and its effect of the war explained.
    The growth of the Sierra Leonean press is discussed and its limitations reviewed, examining both the financial and legislative constraints that characterised it, some of which derive from the colonial period. The role of the media is then evaluated in relation to the internal influence that “biased” journalism had on the shaping of the war, and how it impacted on the fighting. Finally, an example of the Western media

  15. Practical aspects of mobilising property tax: experience in Sierra Leone and Malawi

    Directory of Open Access Journals (Sweden)

    Paul Fish

    2015-08-01

    Full Text Available Much literature has been written about the appeal of property tax as a stable source of revenue for subnational governments in developing countries. Building on this significant background of literature is the author’s practical experience working in local government institutions within both Sierra Leone and Malawi. This article relates to the development and testing of a process of mobilizing the internally generated property tax revenues of local governments, and reports on the results of that process, and the challenges and lessons learned.

  16. ESTRUCTURA DEL BOSQUE TEMPLADO DE GALERÍA EN LA SIERRA DE QUILA, JALISCO

    OpenAIRE

    Ana Luisa Santiago-Pérez; Alberto Ayón Escobedo; Verónica Carolina Rosas-Espinoza; Fabián Alejandro Rodríguez Zaragoza; Sandra Luz Toledo González

    2014-01-01

    El área protegida Sierra de Quila en Jalisco posee una extensa red de arroyos permanentes y temporales donde los bosques de galería mantienen importantes procesos ecológicos y de conectividad biológica. Este trabajo describe su estructura florística arbórea en siete arroyos ubicados en el intervalo altitudinal de 1 876 y 2 200 m. Se establecieron 29 sitios de muestreo de 500 m 2 cada uno (1.45 ha) en los que se midieron todos los individuos leñosos 7 cm de diámetro (DN). Se registraron ...

  17. Geología y fracturas en la estructura San Pedro, sierra del Alto Río Seco, Sierras Subandinas, provincia de Salta Geology and fractures in the San Pedro Structure, Sierra Alto del Río Seco, Sierras Subandinas, Province of Salta

    OpenAIRE

    L. Di Marco

    2005-01-01

    La estructura San Pedro se encuentra en el sector central-septentrional de la unidad morfo-estructural de Sierras Subandinas. Su columna estratigráfica esta caracterizada por una compleja historia geológica en la que se superponen varias cuencas sedimentarias con distinto origen, con un relleno total de más de 10.000 m de espesor y desarrolladas en diferentes edades geológicas y bajo distintos ambientes. El yacimiento San Pedrito (niveles devónicos), ubicado en el bloque Acambuco de la cuenca...

  18. Diamanti e sviluppo Un’analisi critica degli stereotipi sui minatori della Sierra Leone

    Directory of Open Access Journals (Sweden)

    Lorenzo D’Angelo

    2015-06-01

    Full Text Available In the last decade, the Sierra Leone’s diamond mines have been the focus of an intense debate among analysts and experts of the development. Two main interrelated issues have been at stake in this debate: first, to understand the economic and political reasons that had supported the civil war from 1991 to 2002 and, second, to understand how to convert a potential “conflict commodity” in a resource for peace and prosperity. In this paper, I intend to highlight some recurring stereotypes of this debate. In particular, I will focus on a constellation of representations that depict the artisanal miners either as workers poorly organized and prone to irrational economic behavior, or as workers subjected to forms of exploitation akin to slavery. Based on fieldwork conducted in the diamond mining areas of Sierra Leone (2007-2011, this article intends to analyze the main forms of working organization and distribution of earnings among the miners. By challenging some stereotypes characterizing the development discourse, my aim is to show the cultural complexity and the historical density of the practices through which the miners face the risks and uncertainties of their job.

  19. Diamanti e sviluppo Un’analisi critica degli stereotipi sui minatori della Sierra Leone

    Directory of Open Access Journals (Sweden)

    Lorenzo D’Angelo

    2013-06-01

    Full Text Available In the last decade, the Sierra Leone’s diamond mines have been the focus of an intense debate among analysts and experts of the development. Two main interrelated issues have been at stake in this debate: first, to understand the economic and political reasons that had supported the civil war from 1991 to 2002 and, second, to understand how to convert a potential “conflict commodity” in a resource for peace and prosperity. In this paper, I intend to highlight some recurring stereotypes of this debate. In particular, I will focus on a constellation of representations that depict the artisanal miners either as workers poorly organized and prone to irrational economic behavior, or as workers subjected to forms of exploitation akin to slavery. Based on fieldwork conducted in the diamond mining areas of Sierra Leone (2007-2011, this article intends to analyze the main forms of working organization and distribution of earnings among the miners. By challenging some stereotypes characterizing the development discourse, my aim is to show the cultural complexity and the historical density of the practices through which the miners face the risks and uncertainties of their job.

  20. Renealmia alpinia (Rottb.: Maas (Zingiberaceae: planta comestible de la Sierra Norte de Puebla (México

    Directory of Open Access Journals (Sweden)

    Macía, Manuel J.

    2002-06-01

    Full Text Available The edible fruits of Renealmia alpinia are highly valued in the Sierra Norte de Puebla (México where they are managed at a household level. The plant is wild in the región, although a rare species. The aril of the fruit is the edible part. After harvesting, the aril is extracted fresh and processed for local consumption. Sometimes the fruits are commercialized in tradicional markets. Only 19% of the total weight of the fruits is used for food.Los frutos comestibles de Renealmia alpinia son muy apreciados en la Sierra Norte de Puebla (México, en donde son manejados a nivel familiar. La planta crece silvestre en la región, aunque es una especie poco frecuente. La parte comestible es el arilo de los frutos. Tras la cosecha, se extrae en fresco el arilo y se procesa para su consumo familiar. Ocasionalmente los frutos se comercializan en los mercados tradicionales. Solamente el 19 % del peso total de los frutos se aprovecha para alimentación.

  1. Environmental interpretation of lithofacies and biofacies, lower Sierra Madre Limestone, west central Chiapas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, D.K.T.

    1989-03-01

    The Jiquipilas section of the Cretaceous Sierra Madre Limestone, which encompasses the lower part of the formation, was measured northwest of the town of Ocozocuautla in west-central Chiapas, Mexico. The section is 2140 m thick and is characterized by six lithofacies interpreted to represent supratidal, intertidal platform, restricted inner shelf, open inner shelf, shoal, and open-marine middle shelf environments. Overall, the sequence is submergent, with minor emergent episodes. Based upon cluster analysis, three biofacies associations were established: offshore middle shelf, nearshore middle shelf, and inner shelf. The lower 2045 m of the section are dominated by the inner shelf association, while the upper 95 m are dominated by the offshore association. The nearshore middle-shelf association is a minor component throughout the section. Correlation with a measure section from a previous study resulted in a composite thickness for the Sierra Madre Limestone in west-central Chiapas of 3355 m. This figure is considerably greater than previously reported thicknesses for the formation. It indicates that sedimentation on the Yucatan carbonate platform during the middle Cretaceous may have approached sediment accumulation rates in modern sedimentary basins.

  2. Factors Underlying Ebola Virus Infection Among Health Workers, Kenema, Sierra Leone, 2014–2015

    Science.gov (United States)

    Senga, Mikiko; Pringle, Kimberly; Ramsay, Andrew; Brett-Major, David M.; Fowler, Robert A.; French, Issa; Vandi, Mohamed; Sellu, Josephine; Pratt, Christian; Saidu, Josephine; Shindo, Nahoko; Bausch, Daniel G.

    2016-01-01

    Background. Ebola virus disease (EVD) in health workers (HWs) has been a major challenge during the 2014–2015 outbreak. We examined factors associated with Ebola virus exposure and mortality in HWs in Kenema District, Sierra Leone. Methods. We analyzed data from the Sierra Leone National Viral Hemorrhagic Fever Database, contact tracing records, Kenema Government Hospital (KGH) staff and Ebola Treatment Unit (ETU) rosters, and burial logs. Results. From May 2014 through January 2015, 600 cases of EVD originated in Kenema District, including 92 (15%) HWs, 66 (72%) of whom worked at KGH. Among KGH medical staff and international volunteers, 18 of 62 (29%) who worked in the ETU developed EVD, compared with 48 of 83 (58%) who worked elsewhere in the hospital. Thirteen percent of HWs with EVD reported contact with EVD patients, while 27% reported contact with other infected HWs. The number of HW EVD cases at KGH declined roughly 1 month after implementation of a new triage system at KGH and the opening of a second ETU within the district. The case fatality ratio for HWs and non-HWs with EVD was 69% and 74%, respectively. Conclusions. The cluster of HW EVD cases in Kenema District is one of the largest ever reported. Most HWs with EVD had potential virus exposure both inside and outside of hospitals. Prevention measures for HWs must address a spectrum of infection risks in both formal and informal care settings as well as in the community. PMID:27193749

  3. Measured black carbon deposition on the Sierra Nevada snow pack and implication for snow pack retreat

    Directory of Open Access Journals (Sweden)

    O. L. Hadley

    2010-08-01

    Full Text Available Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  4. Measured black carbon deposition on the Sierra Nevada snow pack and implication for snow pack retreat

    Directory of Open Access Journals (Sweden)

    O. L. Hadley

    2010-04-01

    Full Text Available Modeling studies show that the darkening of snow and ice by black carbon (BC deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition on the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  5. Ecofeminismo, mujeres y desarrollo sustentable: el caso de la Sierra de Santa Rosa en Guanajuato

    Directory of Open Access Journals (Sweden)

    Abril Saldaña Tejeda

    2015-01-01

    Full Text Available en este artículo se explora la participación de las mujeres en el Programa de Desarrollo Sustentable Sierra de Santa Rosa, en Guanajuato, de 2001 a 2011. Se expone la aportación del ecofeminismo para la noción de desarrollo sustentable, y para entender el vínculo entre la naturaleza y las mujeres. Se argumenta que la historia de la región, en específico el auge de la industria minera durante la Colonia, es un buen punto de partida para entender los problemas ambientales de la sierra y para visualizar el vínculo entre las estructuras que funcionan en detrimento del medio ambiente y de las mujeres. Así como también que dicho programa tuvo un efecto positivo en la participación social de las mujeres. Sin embargo, existen todavía retos importantes que se manifiestan en estructuras ideológicas, que impiden la participación de las mujeres como líderes y no sólo como trabajadoras, en las condiciones de pobreza que obstaculizan un verdadero compromiso con la sustentabilidad.

  6. Measured Black Carbon Deposition on the Sierra Nevada Snow Pack and Implication for Snow Pack Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, O.L.; Corrigan, C.E.; Kirchstetter, T.W.; Cliff, S.S.; Ramanathan, V.

    2010-01-12

    Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  7. Structure et stratigraphie du secteur oriental de la Sierra Almijara (zone alpujarride, Cordilleres Betiques

    Directory of Open Access Journals (Sweden)

    Sanz Galdeano, C.

    1986-10-01

    Full Text Available La série stratigraphique de la Sierra Almijara est formée. a sa base, par des schistes et des quarzites, sur lesquels se trouve une puissante formation divisée en trois terms. Deux d’entre eux sont de marbres et ils sont séparés par un troisème de schistes, calcoschistes et marbres. La structure montre des plis serrés, de direction N70 et d'autres qui semblent postérieurs de direction NNW-SSE. D'importants décrochements et failles inverses les coupent. On distingue seulement une nappe dans la zone étudiée: celle d’Almijara.
    La serie estratigráfica de Sierra Almijara está formada en su base por esquistos y cuarcitas sobre los que se sitúa una potente formación dividida en tres tramos. Dos de ellos son de mármoles y están separados por otro de esquistos, calcosquistos y mármoles. La estructura muestra apretados pliegues de dirección N70 y otros aparentemente posteriores de dirección NNW-SSE. Importantes fallas de desgarre e inversas los cortan. Sólo se distingue un manto en el área estudiada: el de Almijara

  8. Geology of the Sierra de los ajos (Laguna Merin basin, Rocha, Uruguay)

    International Nuclear Information System (INIS)

    The studied area is located between Lascano city and Sierra de los Ajos hills (department of Rocha, East Uruguay). It is represented by volcanic deposits correspondent to Puerto Gomez and Arequita Formations which are exposed as remarkable and preserved hills in areas recovered by Cenozoic sediments and wetlands. Detailed geological mapping allowed the descriptive characterization of eight volcanic facies: five coherent facies and three volcaniclastic facies. Several structural lineaments located in a constrictive framework, according to the transcurrent system represented by the northeastern portion of the Santa Lucia - Aigua - Merin tectonic corridor (SaLAM), were identified. These lineaments (Bella Vista, India Muerta and Los Ajos) controlled the tecto-magmatic arrange in this portion of the basin, determining petrographic and structural differences in the area. Particularly, to the East of the India Muerta with structural trend No.20 felsic lavas correspondent to the Sierra de los Ajos and related volcaniclastic deposits are present. On the other hand to the West, intermediate to felsic lavas occurred and no volcaniclastic deposits have been yet identified

  9. Geology of the Sierra de los ajos (Laguna Merin basin, Rocha, Uruguay)

    International Nuclear Information System (INIS)

    The studied area is located between Lascano city and Sierra de los Ajos hills (department of Rocha, East Uruguay). It is represented by volcanic deposits correspondent to Puerto Gómez and Arequita Formations which are exposed as remarkable and preserved hills in areas recovered by Cenozoic sediments and wetlands. Detailed geological mapping allowed the descriptive characterization of eight volcanic facies: five coherent facies and three volcaniclastic facies. Several structural lineaments located in a constrictive framework, according to the transcurrent system represented by the northeastern portion of the Santa Lucía - Aiguá - Merín tectonic corridor (SaLAM), were identified. These lineaments (Bella Vista, India Muerta and Los Ajos) controlled the tecto-magmatic arrange in this portion of the basin, determining petrographic and structural differences in the area. Particularly, to the East of the India Muerta with structural trend Nº20 felsic lavas corrrespondent to the Sierra de los Ajos and related volcaniclastic deposits are present. On the other hand to the West, intermediate to felsic lavas occurred and no volcaniclastic deposits have been yet identified

  10. Fumio Matsumura--accomplishments at the University of California, Davis, and in the Sierra Nevada Mountains.

    Science.gov (United States)

    Seiber, James N

    2015-05-01

    Fumio Matsumura joined the University of California, Davis, faculty in 1987 where he served as founding director of the Center for Environmental Health Sciences, associate director of the U.C. Toxic Substances Research and Teaching Program, and chair of the Department of Environmental Toxicology. He was an active affiliate with the NIEHS-funded Superfund Basic Research Program and the NIH Comprehensive Cancer Center. He was in many instances a primary driver or otherwise involved in most activities related to environmental toxicology at Davis, including the education of students in environmental biochemistry and ecotoxicology. A significant part of his broad research program was focused on the long range transport of chemicals such as toxaphene, PCBs and related contaminants used or released in California to the Sierra Nevada mountains, downwind of the urban and agricultural regions of the state. He hypothesized that these chemical residues adversely affected fish and wildlife, and particularly the declining populations of amphibians in Sierra Nevada streams and lakes. Fumio and his students and colleagues found residues of toxaphene and PCBs at higher elevations, an apparent result of atmospheric drift and deposition in the mountains. Fumio and his wife Teruko had personal interests in, and a love of the mountains, as avid skiers, hikers, and outdoor enthusiasts. PMID:25987222

  11. Lead poisoning in a calf from the mining area of Sierra Madrona and Alcudia Valley

    Directory of Open Access Journals (Sweden)

    J Rodríguez-Estival

    2014-01-01

    Full Text Available Se notifica el primer caso registrado de intoxicaci n por plomo (Pb en un ternero del antiguo distrito minero de Sierra Madrona y el Valle de Alcudia (Espa a, que apareci en una finca ganadera con restos visibles de antiguas activides mineras en los terrenos circundantes. El nivel de Pb en sangre detectado en el animal fue de 311 g/dL, y estuvo asociado a diversos s ntomas de intoxicaci n cl nica por Pb, que incluyen par lisis severa, p rdida de sensibilidad en los cuartos traseros e incoordinaci n. Los suelos, las plantas y los puntos de agua presentes en la finca mostraron niveles de Pb por encima de los valores umbral, siendo considerados como suelos altamente contaminados, pastos t xicos para el ganado y agua no potable para el consumo humano. Estos datos indican que la contaminaci n por Pb implica un riesgo para la salud del ganado criado en la zona minera de Sierra Madrona y el Valle de Alcudia.

  12. Dataset of Phenology of Mediterranean high-mountain meadows flora (Sierra Nevada, Spain

    Directory of Open Access Journals (Sweden)

    Antonio Jesús Pérez-Luque

    2015-02-01

    Full Text Available Sierra Nevada mountain range (southern Spain hosts a high number of endemic plant species, being one of the most important biodiversity hotspots in the Mediterranean basin. The high-mountain meadow ecosystems (borreguiles harbour a large number of endemic and threatened plant species. In this data paper, we describe a dataset of the flora inhabiting this threatened ecosystem in this Mediterranean mountain. The dataset includes occurrence data for flora collected in those ecosystems in two periods: 1988–1990 and 2009–2013. A total of 11002 records of occurrences belonging to 19 orders, 28 families 52 genera were collected. 73 taxa were recorded with 29 threatened taxa. We also included data of cover-abundance and phenology attributes for the records. The dataset is included in the Sierra Nevada Global-Change Observatory (OBSNEV, a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

  13. Habitat preferences of butterflies in the Bumbuna Forest, Northern Sierra Leone.

    Science.gov (United States)

    Sundufu, Abu James; Dumbuya, Rashida

    2008-01-01

    The habitat preferences of the butterfly fauna were studied in the Bumbuna Forest Reserve in northern Sierra Leone. The intact forest reserve and a secondary forest regrowth, disturbed as a result of slash-and-burn agriculture, were compared to savanna habitats. Of the 290 specimens collected, 195 butterfly species were included, of which significant proportion were Nymphalidae. Of the 147 forest species, 111 (75.5%) showed preferences for the forest habitats, while 70 (47.6%) and 34 (23.1%) preferred disturbed and savannah habitats, respectively. Numerically, a comparable proportion of savannah species were recorded in the 18 disturbed (73.9%) and 16 savannah habitats (63.2%). Accumulated species richness and diversity indices were lower in the disturbed habitats compared to the forest reserve, but lowest in the savanna habitats. However, a large proportion of forest species, especially those with either a more restricted geographic range or species for which no information on geographic distribution was available, were exclusively captured in the forest patches. The survey indicated the presence of a rich butterfly fauna, which should be systematically collected for further research and study in order to build a good taxonomic database for Sierra Leone. PMID:20302525

  14. Avistamientos recientes de águila real (Aquila chrysaetos en la sierra El Mechudo, Baja California Sur, México Recent sightings of Golden Eagle (Aquila chrysaetos in the Sierra El Mechudo, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Israel Guerrero-Cárdenas

    2013-03-01

    Full Text Available Se reportan nuevos avistamientos de águila real durante 3 años consecutivos (2007-2010 en 2 localidades de la sierra El Mechudo (El Saucito y las Tarabillas, Baja California Sur. Los avistamientos, se realizaron con cámaras-trampa y por observación directa. En BCS, los registros más recientes son de la sierra de la Laguna en el 2000. Se han detectado al menos 4 individuos diferentes, entre juveniles y adultos. La importancia de estos nuevos avistamientos reside en que por primera vez se registra la presencia del águila real en cuerpos de agua dulce.We report new sightings of Golden Eagle for 3 consecutive years (2007-2010 at 2 localities of the Sierra El Mechudo (El Saucito and Tarabillas, Baja California Sur. These sightings were recorded with camera traps and by direct observation. Most recent records from BCS are for the Sierra de la Laguna in 2000. At least 4 different individuals, both juveniles and adults, have been recorded. The importance of these new sightings is that for the first time we registered Golden Eagles infresh water wetlands.

  15. Chemical and isotopic study of thermal springs and gas discharges from Sierra de Chiapas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Nencetti, A; Tassi, F; Vaselli, O [Department of Earth Sciences, Florence (Italy); Macias, J. L [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Magro, G [CNR-Institute of Geosciences and Earth Resources, Pisa (Italy); Capaccioni, B [Institute of Volcanology and Geochemistry, Urbino (Italy); Minissale, A [CNR-Institute of Geosciences and Earth Resources, Florence (Italy); Mora, J. C [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico)

    2005-01-15

    Thermal water and gas discharges south-east of El Chichon volcano, Mexico are associated mainly with NW-SE oriented fault systems. Spring discharges include i) waters with Na-Cl composition and TDS>3000 mg/L; ii) waters with Ca-SO{sub 4} composition and TDS values between 1400 and 2300 mg/L; iii) waters with Na-Cl composition and TDS of 800 to 2400 mg/L and sulphate content up to 650 mg/L and iv) waters with Ca-HCO{sub 3} composition and low salinity (TDS <250mg/L). Most of these waters are associated with free-gas discharges of N{sub 2} (up to 93 % by vol.), CO{sub 2} (2.4 to 31.2 % by vol.) and Ar (up to 1.25 % by vol.) with a predominant meteoric origin. H{sub 2}S is present only in gas samplers collected at El Azufre (up to 1.1 % by vol.). The {delta}13C CO{sub 2} values are always below -9.7% (PDB) and suggest a partially biogenic origin for CO{sub 2}. Chemical and isotopic features of spring discharges indicate that fluid circulation in the Sierra de Chiapas is mainly regulated by meteoric waters that tend to infiltrate the upper and middle-Cretaceous carbonate units up to the lower Cretaceous-upper Jurassic evaporitic formations (by Lopez-Ramos, 1982). The latter provide the main source of the species in solution. No evidence for high-to-medium enthalpy systems at depth beneath the Sierra de Chiapas has been found. [Spanish] La Sierra de Chiapas localizada en el Sureste de Mexico, se caracteriza por la presencia de descargas de gas y agua. La mayoria de los manantiales termales se asocian a rocas volcanicas Terciarias a lo largo de fallas regionales con orientacion NOSE. Las descargas termales se dividen en cuatro grupos: i) aguas con composicion Na-Cl y Solidos Disueltos Totales (SDT) >3000 mg/L; ii) aguas con composicion Ca-SO{sub 4} y valores de SDT entre 1400 y 2300 mg/L; iii) aguas con composicion Na-Cl, bajos contenidos de SDT (800 2400 mg/L) y un contenido de sulfato alto (hasta 650 mg/L) y iv) aguas con una composicion Ca-HCO{sub 3} y salinidad baja

  16. Temporal constraints on the tectonic evolution of Sierra De Famatina, northwestern Argentina, using the fission-track method to date tuffs interbedded in synorogenic clastic sedimentary strata

    Energy Technology Data Exchange (ETDEWEB)

    Tabbutt, K.D. (Dartmouth College, Hanover, NH (USA))

    1990-07-01

    Fission-track dates from seven volcaniclastic units allow time constraints to be placed on synorogenic clastic strata exposed along the flanks of Sierra de Famatina, northwest Argentina. Four formations are exposed along the western margin of Sierra de Famatina. The El Abra conglomerate is composed of clasts eroded from the basement exposed just to the west of Cadena de Paiman. The El Buey Formation contains sediments probably derived from the Precordillera fold and thrust belt to the west. Fission-track dates give a maximum age of 6 Ma for the deposition of both of these formations. The El Durazno Formation, deposited between 6 and 4 Ma, contains proximal volcaniclastic and other clastic rocks derived from the core of Sierra de Famatina. The Santa Florentina conglomerate was derived from the rising Sierra de Famatina and deposited in the past 4 m.y. Sierra de Famatima probably became a positive topographic feature approximately 6 Ma. Prior to that time this region was receiving fine-grained sediments from a distal fold and thrust belt and conglomerates from local basement uplifts. Minor extrusive events (Mogote Formation) coincide both spatially and temporally with deformation along the major reverse faults that control the uplift of Sierra de Famatina. Minimum mean uplift rates calculated for Sierra de Famatina are 0.8 {plus minus} 0.1 mm/yr over a 6.8 m.y. interval.

  17. Complete Genome Sequence of an Ebola Virus Isolate Imported from Sierra Leone to Germany Determined by Circle Sequencing

    Science.gov (United States)

    Mengel, Jan Philipp; Lissin, Artur; Biedenkopf, Nadine; Schultze, Tilman; Mannala, Gopala Krishna; Schudt, Gordian; Kann, Gerrit; Wolf, Timo; Eickmann, Markus; Becker, Stephan

    2016-01-01

    We report here a complete genome sequence of Ebola virus Makona from a nonfatal patient sample that originated in Sierra Leone during the last Ebola virus outbreak in West Africa (species Zaire ebolavirus) using a highly accurate circle sequencing (Cir-seq) method.

  18. Examining Internet Usage Demographic Differences and the Relationship between Internet Usage and Business Outcomes in Sierra Leone

    Science.gov (United States)

    Kamara, Mohamed K.

    2013-01-01

    This study utilized the unified theory of acceptance and use of technology (UTAUT) to determine Internet users' perceptions and behavioral intentions to accept Wi-Fi technology deployment in Sierra Leone. The study sought to investigate (a) the Internet usage rates before and after Wi-Fi adaption in Freetown; (b) differences in Internet usage…

  19. Trauma Healing in Refugee Camps in Guinea: A Psychosocial Program for Liberian and Sierra Leonean Survivors of Torture and War

    Science.gov (United States)

    Stepakoff, Shanee; Hubbard, Jon; Katoh, Maki; Falk, Erika; Mikulu, Jean-Baptiste; Nkhoma, Potiphar; Omagwa, Yuvenalis

    2006-01-01

    From 1999 to 2005, the Minneapolis-based Center for Victims of Torture (CVT) served Liberian and Sierra Leonean survivors of torture and war living in the refugee camps of Guinea. A psychosocial program was developed with 3 main goals: (1) to provide mental health care; (2) to train local refugee counselors; and (3) to raise community awareness…

  20. The Fear of Poisoning and the Management of Urban Social Relations among the Professional Group in Freetown, Sierra Leone.

    Science.gov (United States)

    Harrell-Bond, B. E.

    1978-01-01

    Social relationships among professionals in Sierra Leone are marked by competition and tension. An examination of food symbolism, patterns of food sharing, and attitudes toward the safety of accepted proffered food and drink provides a means of looking at how the professionals structure and manage their social relations. (Author/EB)

  1. REGIONAL ANALYSIS OF INORGANIC NITROGEN YIELD AND RETENTION IN HIGH-ELEVATION ECOSYSTEMS OF THE SIERRA NEVADA AND ROCKY MOUNTAINS

    Science.gov (United States)

    Yields and retention of inorganic nitrogen (DIN) and nitrate concentrations in surface runoff are summarized for 28 high elevation watersheds in the Sierra Nevada, California and Rocky Mountains of Wyoming and Colorado. Catchments ranged in elevation from 2475 to 3603 m and from...

  2. Presencia de Phylodryas aestivus (Dumeril, Bibrón & Dumeril, 1854) en Sierra de la Ventana (provincia de Buenos Aires)

    OpenAIRE

    Couturier, Gustavo; Grisolia, Carlos S.

    1989-01-01

    La presente nota tiene por objeto citar a Philodryas aestivus para el área de Sierra de la Ventana. Con anterioridad la presencia de este culébrido para dicha región fue mencionada como probable por Miranda, Couturier y Williams (1982).

  3. 77 FR 63328 - Notice of Availability of the Record of Decision for the Chokecherry and Sierra Madre Wind Energy...

    Science.gov (United States)

    2012-10-16

    ... Madre Wind Energy Project and Approved Visual Resource Management Plan Amendment for Public Lands...) announces the availability of the Record of Decision (ROD) for the Chokecherry and Sierra Madre Wind Energy...: The BLM evaluated the potential wind energy development on a broad level to determine...

  4. Flora útil de los cafetales en la Sierra Norte de Puebla, México Useful plants of the Sierra Norte de Puebla, Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Martínez

    2007-06-01

    Full Text Available Los cafetales de la Sierra Norte de Puebla son agroecosistemas variados en composición y estructura, donde se pueden encontrar especies vegetales cultivadas y silvestres, nativas e introducidas, y cuya diversidad florística está estrechamente ligada a las condiciones sociales, económicas y ecológicas en las que se inserta la producción del café. En la última década el cultivo de esta planta ha estado en crisis debido a los bajos precios del producto; sin embargo,los agricultores mantienen los cafetales como fuente de ingreso adoptando nuevas estrategias para obtener recursos económicos mediante la introducción o incremento de cultivos de importancia económica, como pimienta, mamey o plantas medicinales, aprovechando la versatilidad y posibilidades de reorganización de estos agroecosistemas. En este trabajo se presenta el inventario de la flora útil encontrada en cafetales de la SNP. A la fecha están registradas 319 especies pertenecientes a 238 géneros y 99 familias; 90 especies son objeto de comercio y pueden representar nuevas fuentes de ingreso; 256 son nativas y 63 introducidas y se han agrupado en 13 categorías antropocéntricas, de las cuales las medicinales y comestibles son las más numerosas.Coffee plantations in the Sierra Norte de Puebla (SNP are agroecosystems with variable composition and structure. These agroecosystems include native and introduced plant species, as well as cultivated and wild ones. Plant diversity in coffee plantations is closely related to the social, economic, and ecological context into which coffee production is inserted. In the last decade, coffee cultivation has been in crisis due to low prices. Nevertheless, farmers of the SNP maintain their plantations as a source of income, with new strategies such as the introduction or increase of plants with economic value, like allspice (Pimenta dioica, mamey (Pouteria sapota, and medicinal plants, taking advantage of the versatility and possibilities

  5. Deformación sísmica reciente de la sierra de Pie de palo, provincia de San Juan

    Directory of Open Access Journals (Sweden)

    Guillermo Monsalvo

    2014-06-01

    Full Text Available En este trabajo se estudia la actividad sísmica en la sierra de Pie de Palo durante enero 2008 a diciembre 2009. Los datos utilizados fueron registrados por 52 estaciones sismológicas de los experimentos SIEMBRA y ESP. En ese período, 149 sismos corticales fueron localizados con magnitudes locales entre 0,8sierra de Pie de Palo con una ausencia en el sector centro occidental de la sierra y valle de Tulum. Además, se observa una distribución de sismos diferente para la corteza situada al norte con respecto al sur de la sierra: en el bloque norte, 52 hipocentros ocurrieron a niveles de corteza media a inferior mientras que en el boque sur, 73 sismos se concentraron principalmente en niveles corticales intermedios. Se observa una buena correlación de la sismicidad con el modelo de corteza local propuesto por Perarnau et al. (2010 posicionándose la mayor ocurrencia de actividad sísmica a profundidades de corteza media a inferior y ninguna determinación sísmica en el nivel más inferior sugiriendo un comportamiento probablemente más dúctil. Un total de 128 mecanismos focales fueron determinados utilizando primeros arribos de ondas P que indican soluciones principalmente de tipo inverso e inverso con componente de rumbo. Los resultados están de acuerdo con un acortamiento cortical en dirección aproximada este-oeste. Además, el estudio de las fuentes sísmicas realizado sugiere una deformación asociada diferente para los bloques que componen a la sierra, tanto en su extensión areal como en profundidad cortical.

  6. Plant endemics to Sierra de Gredos (central Spain: taxonomic, distributional, and evolutionary aspects

    Directory of Open Access Journals (Sweden)

    García, Bernardo

    2008-12-01

    Full Text Available Causes related to a low number of endemics to Sierra de Gredos (central Iberian Peninsula are poorly understood. Taxonomic, distributional and genetic aspects of the 12 endemic taxa (species and subspecies are herein discussed. New populations found in the last years provide new chorological reports and taxa to science. As a result, we extend the distribution range of Pseudomisopates rivas-martinezii and describe a new subspecies (Teucrium oxylepis subsp. Gredense. Genetic variation was investigated by sequencing the ITS (Internal Transcribed Sequence region, which is a widespread nuclear DNA region used to detect significant sequence divergence at the species and population levels. At the species level, only eight endemics to this large mountain range (c. 4,800 km2 indicates both limited speciation events coupled with their persistence, despite the high species richness of the flora of Sierra de Gredos (>2,500. According to the levels of ITS sequence divergence, significant isolation processes may have predated the Quaternary in Sierra de Gredos to account for divergence of the monotypic genus Pseudomisopates from its closest relatives (Misopates, Acanthorrhinum. Isolation of the other seven endemic species from their closest relatives has been a more recent process, as revealed by the limited ITS sequence variation obtained in this study. At the population level, no net nucleotide substitutions were observed between distant populations of the endemic species: Antirrhinum grosii, Astragalus devesae, Centaurea avilae, Dianthus gredensis, Echinospartum barnadesii, Pseudomisopates rivas-martinezii, Santolina oblongifolia. In contrast, the three populations of Sedum lagascae displayed a relatively high number (4 of nucleotide substitutions. These results, together with limited morphological differentiation, may reflect insufficient population isolation of seven of the eight endemic species of Sierra de Gredos in the Quaternary. Recurrent population

  7. Indicadores de calidad física en suelos de la Región Pampeana Norte de Argentina bajo siembra directa Physical quality indicators in soils from the northern Pampa region of Argentina under no till management

    Directory of Open Access Journals (Sweden)

    Laura Ferreras

    2007-12-01

    Full Text Available El uso sustentable de las tierras requiere conservar propiedades edáficas que son importantes desde el punto de vista de la fertilidad y el laboreo del suelo. La alteración de las condiciones del suelo por el manejo puede afectar la producción de los cultivos debido a que influye en la distribución de la materia orgánica y dinámica de nutrientes; como así también sobre la agregación y porosidad del suelo. Una de las regiones del mundo donde los suelos han sido sujetos a un intenso uso agrícola durante las últimas décadas es la Región Pampeana Norte. En los últimos años los productores han adoptado la siembra directa en forma creciente. El objetivo de este trabajo fue evaluar, en suelos representativos de esta región, parámetros de calidad física del suelo en sistemas agrícolas bajo siembra directa en comparación con el mismo tipo de suelo en su condición quasi-prístina. Se realizó la caracterización física de suelos cultivados de once establecimientos correspondientes a ensayos de la Red de Nutrición de la Región CREA Sur de Santa Fe ubicados en las provincias de Santa Fe, Córdoba y Buenos Aires. Se realizó además un muestreo en un sector adyacente sobre el mismo tipo de suelo en su condición quasi-prístina. Se extrajeron muestras compuestas de suelo a dos profundidades: 0-0,08 m y 0,08 m al límite inferior del horizonte Ap y se evaluó el porcentaje de agregados estables al agua (Ea y al etanol (Ee, el carbono orgánico total (COT, la densidad aparente (DA y la densidad del suelo máxima (DMAX. La resistencia mecánica (RM se midió a intervalos de 0,05 m desde superficie hasta 0,35 m de profundidad. Se constituyeron dos grupos de suelos en función de la textura: el Grupo I (con un contenido de arcilla en superficie que oscila entre 215 y 265 g kg-1 y el Grupo II (suelos que poseen entre 98 y 170 g kg-1 de arcilla en superficie. Los valores de Ea, Ee y COT fueron mayores (p Sustainable land use implies the

  8. Coherent Cloudiness Variability from Sierra Nevada to the Sea in California

    Science.gov (United States)

    Sumargo, E.; Cayan, D. R.

    2015-12-01

    Cloud variability serves as the principal modulator of incoming solar radiation. These cloud effects are particularly important in mountain settings such as the Sierra Nevada in California, because the solar irradiance is a primary input to the snowpack energy balance. An important, unanswered question is whether the mountain clouds over the Sierra Nevada are only one part of a larger-scale system or whether they vary distinctly from cloud patterns upstream over the Central Valley and coastal areas. To address this question we investigate cloud variability over California using 19 years (1996-2014) of GOES visible albedo product with 4-km spatial and 30-minute temporal resolutions. Two domains are considered: high elevations in which only higher (>800m) elevations are included, thus excluding the coast and valley clouds, and all elevations which includes all elevations from the offshore North Pacific to Nevada. Our focus is on the spring and early summer period, which is crucial because it includes much of the snowmelt runoff from the Sierra Nevada. Inter-annual variation of cloudiness, represented by the coefficient of variation of cloud albedo, reveals the highest relative variability from California coasts and lowlands in the winter and spring to highlands and mountains in the summer and autumn. This pattern also occurs across shorter to longer time-scales, with coefficient of variation ranging from 30-180% on daily scale to 5-40% on seasonal scale. Considering the spatial structure of anomalous cloudiness, rotated EOF (REOF) analyses of de-seasonalized daily cloud albedo in the high elevation domain yields patterns and temporal variations that are well correlated with those from the all elevation domain. This indicates that, to a large degree, the mountain clouds co-vary with those over the Central Valley and the California coast, even though the valley and coastal clouds include low stratus clouds. The monthly standard deviations of the amplitudes of the time

  9. Seasonal frost conditions and permafrost regime distribution in the high lands of Sierra Nevada (Spain)

    Science.gov (United States)

    Oliva, Marc; Gómez-Ortiz, Antonio; Salvador-Franch, Ferran; Salvà-Catarineu, Montserrat; Palacios, David; Tanarro, Luis Miguel; Ramos, Miguel

    2016-04-01

    Sierra Nevada, Southern Spain (37°S, 3°W), is the massif including the southernmost permafrost remnants in Europe. Over the last decades the distribution of permafrost in this massif has been examined through a combined approach including geomorphological, geophysical and monitoring studies. The purpose of this communication is to summarize all the studies relating to soil thermal regime in the high lands of Sierra Nevada. A 114.5 m deep borehole was drilled in 2000 in the Veleta summit (3380 m) in order to monitor soil temperatures in the summits of the massif. No permafrost regime was detected, with average temperatures stabilizing at 20 m depth at 2 °C. Seasonal frost conditions were also detected in periglacial landforms such as solifluction lobes and sorted-circles. In the Rio Seco cirque the mean annual temperatures in a solifluction lobe located in a southern glacial cirque of the massif (3005 m) were 3.9 °C at 1 m depth between 2006 and 2012; in the north-exposed San Juan valley, soil temperatures in another solifluction landform (2864 m) were 3.9 °C at 1 m depth between 2003 and 2012. In a sorted-circle located in the high plateau of Cerro de los Machos (3297 m) soil temperatures recorded an average of 1.7 °C at 50 cm depth between 2003 and 2011. The only place where temperatures were permanently negative was inside of the only active rock glacier distributed in the Veleta cirque, on the northern slope of the Veleta peak. Here, the remnants of a small glacier that existed during the Little Ice Age (LIA) are still present in the form of buried ice and permafrost buried under the boulders of this rock glacier. Temperatures averaged 0.2 °C at 1 m depth between 2006 and 2013, with permanently negative temperatures below this level until, at least, 10 m depth. Consequently, seasonal frost is widespread nowadays in most of the Sierra Nevada, with permafrost conditions strongly conditioned by the geomorphological setting and the recent environmental

  10. Diversidad de maiz en la sierra sur de Oaxaca, México: conocimiento y manejo tradicional.

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    Beatriz Rendón-Aguilar

    2015-07-01

    Full Text Available El estado de Oaxaca representa un importante acervo de maíz en México. Estudios previos han indicado la presencia de muchas variedades locales y razas agronómicas en la Sierra Norte y Valles Centrales. La Sierra Sur ha sido poco estudiada a pesar de la presencia de comunidades indígenas zapotecas, las cuales cultivan maíz, entre otras especies, y han preservado las variedades locales. El presente estudio responde a las siguientes preguntas: ¿cuál es la diversidad de maíz en términos de variedades tradicionales y razas agronómicas en la región zapoteca de Los Loxicha?, ¿la diversidad de maíz sigue un patrón de distribución a lo largo de un gradiente altitudinal?, ¿cuáles prácticas promueven y mantienen esta diversidad? Para contestar estas preguntas se realizó un estudio en cinco municipios de la Sierra Sur de Oaxaca. Durante 2007 se aplicaron entrevistas estructuradas a 930 agricultores para describir el proceso de manejo de semilla. La caracterización morfológica de las razas agronómicas se basó en muestras de mazorcas obtenidas en 375 milpas, con 20 plantas por milpa. Se encontraron altos niveles de diversidad local de maíz, con 36 variedades tradicionales correspondientes a 10 razas agronómicas. Las razas exhibieron diferencias en términos de variación fenotípica, distribución altitudinal y algunas muestran adaptación local. Los agricultores practican algunas formas de manejo ancestral para la selección de mazorcas y semillas, manteniendo, así, ciertos niveles de diferenciación entre las variedades y las razas agronómicas. Sin embargo, al sembrar diferentes variedades dentro de la misma parcela, se promueve el flujo génico y la introgresión entre ellas, manteniendo y promoviendo la diversidad fenotípica y genética.

  11. Sierra Nevada serpentinites. An important element in the architectonic heritage of Granada (Spain).

    Science.gov (United States)

    Navarro, Rafael; Pereira, Dolores; Rodríguez-Navarro, Carlos; Sebastián-Pardo, Eduardo

    2013-04-01

    Serpentinites are widely used in historic buildings in the whole world, from Ancient Greek or Egypt to more recent colonial buildings in the USA. Serpentinites from Sierra Nevada (S of Spain) have been traditionally used as ornamental elements in historic buildings of Granada city, both indoors and outdoors. The Cathedral, Carlos V Palace, Royal Chancery and some others are good examples of their use. Some other important cases can be found outside Granada, like El Escorial monastery, Las Salesas Reales convent, etc… all of them part of Madrid architectonic heritage. There are two quarries located in Sierra Nevada that supplied all the material to make the different elements in the cited buildings. In this work, a thorough characterization of the main serpentinites from Sierra Nevada, their uses, and their state of conservation in selected buildings from Granada has been performed. Samples from the main original quarry and from one historical building (Real Chancillería) have been analysed, determining the mineralogical and geochemical composition, texture, water parameters (absorption, porosity, density) and possible alteration by salt formation. It has been observed that the mineralogical and geochemical compositions are similar in both sets of samples, although the ones coming from the historical building show a highly advanced state of alteration. Regarding physical and mechanical parameters, samples from the quarry have very low water absorption values, while the porosity of serpentinites sampled from the Real Chancillería is comparatively much higher. We explain this difference as due to the weathering of the emplaced serpentinites by salt crystallization processes (mainly gypsum or epsomite), that generate strong internal pressures causing the disintegration of the whole natural stone. In addition, the increase of the porosity can be caused by dissolution processes related to the presence of acid solutions related to oxidation and hydrolysis of iron

  12. Sierra Vegetation

    Data.gov (United States)

    California Department of Resources — CDF-FRAP compiled the 'best available' land cover data into a single data layer, to support the various analyses required for the 2002 Forest and Range Assessment....

  13. Cacao 3 (Cc 3, Arte rupestre del formativo temprano en Antofagasta de la Sierra, Catamarca, Argentina

    Directory of Open Access Journals (Sweden)

    Alvaro Rodrigo Martel

    2004-01-01

    Full Text Available En el presente trabajo hemos abordado el estudio de la producción del arte rupestre del sitio Cacao 3 –Cc3- (Antofagasta de la Sierra, Catamarca con relación a las prácticas socioculturales de grupos agropastoriles del periodo Formativo Temprano en la Puna meridional argentina, haciendo hincapié en el emplazamiento del sitio y su asociación contextual con las demás evidencias arqueológicas conocidas para el área de estudio y estableciendo las relaciones entre las manifestaciones rupestres de Cc3 con las de otros sitios, a nivel micro y macrorregional, a través de indicadores estilísticos

  14. Mineralización de uranio en la Sierra de Velasco, La Rioja

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    Orquídea Morello

    2013-09-01

    Full Text Available En esta contribución se describe una mineralización de uranio hallada en la sierra de Velasco, provincia de La Rioja, noroeste de Argentina. La geología de la región incluye granitos, pegmatitas y rocas metamórficas. Las rocas hospedantes de la mineralización son el granito La Chinchilla, de edad carbonífera y las metamorfitas del Complejo La Cébila, de edad precámbrica-ordovícica inferior. La mineralización es perigranítica; se encuentra diseminada, en fracturas y alojada en el contacto entre el granito y la metamorfita. En el granito La Chinchilla se identificó un óxido de U-Nb-Ta, y en las metamorfitas se reconocieron silicatos (uranofano, betauranofano, fosfatos (furcalita y meta-autunita y minerales negros de uranio (uraninita -variedad pechblenda- y coffinita.

  15. Biodiversity of the Sierra del Divisor Zone Reserved (Peru: a view from small mammals

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    César E. Medina

    2015-10-01

    Full Text Available This study documents the small mammalian diversity in the Zona Reservada Sierra del Divisor (ZRSD. Six sites were evaluated between 2011 and 2013 with capture techniques (Victor snap traps, Tomahawk traps, Pitfall traps and mist nets. 67 species of small mammals were recorded (five marsupials, 10 rodents and 52 bats, 32 of which are new records for the ZRSD and two are species of the most rare and endemic rodents of Peru, the “Peruvian Aquatic Rat” Neusticomys peruviensis (Cricetidae: Ichthyomyini and “Ucayali´s Aquatic Mouse” Amphinectomys savamis (Cricetidae: Oryzomyini. On the other hand, the marsupial Marmosops bishopi; rodents Neacomys minutus, Euryoryzomys macconnelli, Scolomys melanops and Proechimys kulinae; and the bats Artibeus planirostris and Rhinophylla pumilio were the most plenty. Our finding showed the importance of the re-categorization of Reserved Zone to National Park like as a significant contribution to the conservation of the Peruvian mammals.

  16. Source identification in acoustics and structural mechanics using Sierra/SD.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Aquino, Wilkins [Duke University Durham, NC; Ross, Michael

    2013-03-01

    In this report we derive both time and frequency-domain methods for inverse identification of sources in elastodynamics and acoustics. The inverse/design problem is cast in a PDE-constrained optimization framework with efficient computation of gradients using the adjoint method. The implementation of source inversion in Sierra/SD is described, and results from both time and frequency domain source inversion are compared to actual experimental data for a weapon store used in captive carry on a military aircraft. The inverse methodology is advantageous in that it provides a method for creating ground based acoustic and vibration tests that can reduce the actual number of flight tests, and thus, saving costs and time for the program.

  17. Stratified Sampling of Neighborhood Sections for Population Estimation: A Case Study of Bo City, Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Roger Hillson

    Full Text Available There is a need for better estimators of population size in places that have undergone rapid growth and where collection of census data is difficult. We explored simulated estimates of urban population based on survey data from Bo, Sierra Leone, using two approaches: (1 stratified sampling from across 20 neighborhoods and (2 stratified single-stage cluster sampling of only four randomly-sampled neighborhoods. The stratification variables evaluated were (a occupants per individual residence, (b occupants per neighborhood, and (c residential structures per neighborhood. For method (1, stratification variable (a yielded the most accurate re-estimate of the current total population. Stratification variable (c, which can be estimated from aerial photography and zoning type verification, and variable (b, which could be ascertained by surveying a limited number of households, increased the accuracy of method (2. Small household-level surveys with appropriate sampling methods can yield reasonably accurate estimations of urban populations.

  18. Inferring ecological relationships from occupancy patterns for California Black Rails in the Sierra Nevada foothills

    Science.gov (United States)

    Richmond, Orien Manu Wright

    The secretive California Black Rail (Laterallus jamaicensis coturniculus ) has a disjunct and poorly understood distribution. After a new population was discovered in Yuba County in 1994, we conducted call playback surveys from 1994--2006 in the Sierra foothills and Sacramento Valley region to determine the distribution and residency of Black Rails, estimate densities, and obtain estimates of site occupancy and detection probability. We found Black Rails at 164 small, widely scattered marshes distributed along the lower western slopes of the Sierra Nevada foothills, from just northeast of Chico (Butte County) to Rocklin (Placer County). Marshes were surrounded by a matrix of unsuitable habitat, creating a patchy or metapopulation structure. We observed Black Rails nesting and present evidence that they are year-round residents. Assuming perfect detectability we estimated a lower-bound mean Black Rail density of 1.78 rails ha-1, and assuming a detection probability of 0.5 we estimated a mean density of 3.55 rails ha-1. We test if the presence of the larger Virginia Rail (Laterallus limicola) affects probabilities of detection or occupancy of the smaller California Black Rail in small freshwater marshes that range in size from 0.013-13.99 ha. We hypothesized that Black Rail occupancy should be lower in small marshes when Virginia Rails are present than when they are absent, because resources are presumably more limited and interference competition should increase. We found that Black Rail detection probability was unaffected by the detection of Virginia Rails, while, surprisingly, Black and Virginia Rail occupancy were positively associated even in small marshes. The average probability of Black Rail occupancy was higher when Virginia Rails were present (0.74 +/- 0.053) than when they were absent (0.36 +/- 0.069), and for both species occupancy increased with marsh size. We assessed the impact of winter (November-May) cattle grazing on occupancy of California Black

  19. Post War Challenges of Educational Delivery in Junior Schools in Bo City Southern Sierra Leone

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    Saffa Barbee Massaquoi

    2012-02-01

    Full Text Available This study investigated the availability and adequacy of teaching and learning materials, administrative problems and qualifications of teachers relative to their teaching effectiveness in junior secondary schools in Bo city, Southern Sierra Leone. The design of the study was a descriptive survey. The major findings and conclusion were that the junior secondary schools have trained and qualified teachers. The majority of the schools were over crowded with pupils in poorly ventilated classrooms. Three- fourths of the schools did not have science and computer laboratories, libraries, home economics facilities and generally the schools did not have appropriate toilet facilities. The difficult and bureaucratic processes involved in the recruitment of teachers were found to be responsible for the late payment of salaries for newly employed teachers. Teaching and learning materials were grossly inadequate in all the schools studied in the Bo city.

  20. Paleoclimatic Implications of Holocene Plant Remains from the Sierra Bacha, Sonora, Mexico

    Science.gov (United States)

    Van Devender, Thomas R.; Burgess, Tony L.; Piper, Jessie C.; Turner, Raymond M.

    1994-01-01

    A total of 93 plant taxa were identified from 11 packrat ( Neotoma sp.) midden samples from the Sierra Bacha on the coast of the Gulf of California near Puerto Libertad, Sonora, Mexico. Nine indurated samples have radiocarbon dates ranging from 9970 to 320 yr B.P. Sonoran desertscrub was present on rocky slopes throughout the Holocene. Early Holocene assemblages dominated by Fouquieria columnaris (boojum tree) reflect vegetation and climate more like modern Baja California with greater winter rainfall and cooler summers. Middle Holocene vegetation was essentially modern with modest indications of greater monsoonal rainfall even though cold-water upwelling locally inhibits summer precipitation. The results are similar to all previous midden reconstructions of early and middle Holocene climates in the Sonoran Desert, but contradict general atmospheric circulation model simulations.

  1. Comparative Bacteriological Study of Two Wild Boar Populations in Sierra Morena (Ja�n, Spain

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    Antonio NOTARIO

    2010-12-01

    Full Text Available The aim of this study was to investigate the presence of various bacterial species in the wild boar populations of Lugar Nuevo and Selladores-Contadero woodlands from Sierra Morena (Spain. Bacteriological analyses were carried out on a total of 229 wild boar individuals hunted in the period 2000-2003 in eleven experimental plots which are representative for the different biotopes of the area. The following species were detected: Brucella ovis, Clostridium sp., Corynebacterium sp., Streptococcus pneumoniae, Escherichia coli, Mycobacterium bovis, Mycobacterium avium subsp. paratuberculosis, Mannheimia haemolytica, Pasteurella multocida, Pseudomonas aeruginosa, Chlamydophila psittaci, Staphylococcus aureus and Staphylococcus sp. and the bacterial prevalence was estimated for each of them. The results provide useful indications of the health status of wild boar in both locations and highlight the potential of the wild boar populations to act as biological reservoirs of certain microorganisms that can be passed onto other vertebrate wild animals and humans.

  2. Thermal contact algorithms in SIERRA mechanics : mathematical background, numerical verification, and evaluation of performance.

    Energy Technology Data Exchange (ETDEWEB)

    Copps, Kevin D.; Carnes, Brian R.

    2008-04-01

    We examine algorithms for the finite element approximation of thermal contact models. We focus on the implementation of thermal contact algorithms in SIERRA Mechanics. Following the mathematical formulation of models for tied contact and resistance contact, we present three numerical algorithms: (1) the multi-point constraint (MPC) algorithm, (2) a resistance algorithm, and (3) a new generalized algorithm. We compare and contrast both the correctness and performance of the algorithms in three test problems. We tabulate the convergence rates of global norms of the temperature solution on sequentially refined meshes. We present the results of a parameter study of the effect of contact search tolerances. We outline best practices in using the software for predictive simulations, and suggest future improvements to the implementation.

  3. Inevitable changes in snowpack and water resources over California's Sierra Nevada

    Science.gov (United States)

    Hall, A. D.; Sun, F.; Walton, D.; Berg, N.; Schwartz, M. A.

    2015-12-01

    Here we use a downscaling technique incorporating both dynamical and statistical methods to project end-of-century changes in spring snow water equivalent in California's Sierra Nevada. The technique produces outcomes for all Global Climate Models (GCMs) and the four greenhouse gas forcing scenarios adopted by the Intergovernmental Panel on Climate Change (IPCC). For all GCMs and forcing scenarios, significant snow loss occurs at elevations below 2500 meters, despite increasing precipitation in many GCMs. The loss is significantly enhanced by snow albedo feedback. The approximate intermodel range in percent of total snow remaining in the entire region is 60-85% for a likely "mitigation" scenario, and 35-55% for the "business-as-usual" scenario. Thus significant snowpack decrease by century's end is inevitable, even if the loss can be cushioned through greenhouse gas emissions reductions over the coming decades. The snowpack loss also leads to significant changes in runoff timing, which are also inevitable.

  4. DIAGNOSIS IMPORTANCE OF RURAL DEVELOPMENT OF A MODEL AGROFORESTAL IN PEASANT COMMUNITIES OF SIERRA DE HUAUTLA

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    Miguel Uribe-Gómez

    2015-07-01

    Full Text Available Family agricultural is socioeconomically important in rural areas, but in Mexico, from the 80's this production system presents social stagnation. This type of agriculture presents a dynamic reality in the interests of each producer and limiting access to factors of production (land, labor and capital. In this investigation a methodology for analysis and diagnosis of production systems in rural areas, in two communities in the Country Sierra de Huautla Tepalcingo, Morelos, Mexico was applied. The proposal is based on an assessment of the environmental, historical, technological and socio-economic assessment of different productive activities for different types of units Family Production of the communities studied. The study showed that 40% of Family Production Units fail to exceed the threshold of survival and show impossibility capitalization medium and long term. So it is advisable to implement a model of local agricultural development to improve the socioeconomic conditions of Family Production Units of peasant communities.

  5. Paleozoic-involving thrust array in the central Sierras Interiores (South Pyrenean Zone, Central Pyrenees): regional implications

    Science.gov (United States)

    Rodriguez, L.; Cuevas, J.; Tubía, J. M.

    2012-04-01

    This work deals with the structural evolution of the Sierras Interiores between the Tena and Aragon valleys. The Sierras Interiores is a WNW-trending mountain range that bounds the South Pyrenean Zone to the north and that is characterized by a thrust-fold system with a strong lithological control that places preferably decollements in Triassic evaporites. In the studied area of the Sierras Interiores Cenomanian limestones cover discordantly the Paleozoic rocks of the Axial Zone because there is a stratigraphic lacuna developed from Triassic to Late Cretaceous times. A simple lithostratigraphy of the study area is made up of Late Cenomanian to Early Campanian limestones with grey colour and massive aspect in landscape (170 m, Lower calcareous section), Campanian to Maastrichtian brown coloured sandstones (400-600 m, Marboré sandstones) and, finally, Paleocene light-coloured massive limestones (130-230 m), that often generate the higher topographic levels of the Sierras Interiores due to their greater resistance to erosion. Above the sedimentary sequence of the Sierras Interiores, the Jaca Basin flysch succession crops out discordantly. Based on a detailed mapping of the studied area of the Sierras Interiores, together with well and structural data of the Jaca Basin (Lanaja, 1987; Rodríguez and Cuevas, 2008) we have constructed a 12 km long NS cross section, approximately parallel to the movement direction deduced for this region (Rodríguez et al., 2011). The main structure is a thrust array made up of at least four Paleozoic-involving thrusts (the deeper thrust system) of similar thickness in a probably piggyback sequence, some of which are blind thrusts that generate fold-propagation-folds in upper levels. The higher thrust of the thrust array crops out duplicating the lower calcareous section all over the Sierras Interiores. The emplacement of the deeper thrust system generated the tightness of previous structures: south directed piggyback duplexes (the upper

  6. Ebola Virus Disease Complications as Experienced by Survivors in Sierra Leone

    Science.gov (United States)

    Tiffany, Amanda; Vetter, Pauline; Mattia, John; Dayer, Julie-Anne; Bartsch, Maria; Kasztura, Miriam; Sterk, Esther; Tijerino, Ana Maria; Kaiser, Laurent; Ciglenecki, Iza

    2016-01-01

    Background. Thousands of people have survived Ebola virus disease (EVD) during the ongoing outbreak. However, data about the frequency and risk factors of long-term post-EVD complications remain scarce. We describe the clinical characteristics of EVD survivors followed in a survivor clinic in Freetown, Sierra Leone. Methods. A survivor clinic opened within an Ebola treatment center compound in Freetown, Sierra Leone. At each visit, clinical and psychological assessments were conducted and free treatment was offered. Survivors were referred to a partner's hospitals if their condition could not be managed in the clinic. We used routinely collected data from the clinic to describe long-term complications of EVD and their risk factors. Results. A total of 1001 medical consultations for 166 patients were performed between 3 February and 21 June 2015. The most frequent complaints and diagnoses were arthralgia (n = 129 [77.7%]), fatigue (n = 116 [69.8%]), abdominal pain (n = 90 [54.2%]), headache (n = 87 [52.4%]), anemia (n = 83 [50%]), skin disorders (n = 81 [48.8%]), back pain (n = 54 [32.5%]), and alopecia (n = 53 [31.9%]). Ocular complications were diagnosed in 94 survivors (56.7%); uveitis was the most common (n = 57 [34%]). Survivors were 10 times more likely to develop uveitis post-EVD if they presented with red/injected eyes during the acute phase of their illness. Conclusions. Post-EVD complications among our patients were similar to those described previously and were detected early following the acute phase of disease. Follow-up of survivors should begin immediately after discharge to address sequelae as they arise and reduce the potential for development of long-term disabilities such as blindness. PMID:27001797

  7. The mineral resources of the Sierra Nevada de Santa Marta, Columbia (Zone I)

    Science.gov (United States)

    Tschanz, Charles McFarland; Jimeno V., Andres; Cruz, Jaime B.

    1970-01-01

    The Sierra Nevada de Santa Maria on the north coast of Colombia is an isolated triangular mountain area that reaches altitudes of almost 19,000 feet. The exceedingly complex geology is shown on the 1:200,000 geologic map. Despite five major periods of granitic intrusion, three major periods of metamorphism, and extensive volcanic eruptions, metallic deposits are small and widely scattered. Sulfide deposits of significant economic value appear to be absent. Many small copper deposits, of chalcocite, cuprite, malachite, and azurite are found in epidotized rock in Mesozoic redbeds and intercalated volcanic rocks, but their economic potential is very small. Deposits of other common base metals appear to be absent. The most important metallic deposits may prove to be unusual bimineralic apatite-ilmenite deposits associated with gneissic anorthosite. The known magnetite deposits are too small to be exploited commercially. Primary gold deposits have not been identified and the placer deposits are uneconomic and very small. The largest and most important deposits are nonmetallic. Enormous reserves of limestone are suitable for cement manufacture and some high-purity limestone is suitable for the most exacting chemical uses. Small deposits of talc-tremolite could be exploited locally for ceramic use. The important noncoking bituminous coal deposits in the Cerrej6n area are excluded from this study. Other nonmetallic resources include igneous dimension stone in a variety of colors and textures, and agricultural dolomite. There probably are important undeveloped ground water resources on the slopes of the wide Rancheria and Cesar valleys, which separate the Sierra Nevada from the Serrania de Persia.

  8. Pattern of skin infections in black Africans of Sierra Leone (West Africa

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    Bari Arfan ul

    2007-01-01

    Full Text Available Background: Physical differences among human populations may lead to variable prevalence of skin disorders in different ethnicities. Skin infections are one of the important curable and largely preventable categories of skin disorders in the communities. Aim: The purpose of the study was to see the patterns of skin infections in black Africans of Sierra Leone and to compare with other ethnic populations. Materials and Methods: Local blacks of all age groups presenting in Dermatology out patient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone were included (from Nov 2004 to Oct 2005. Relevant clinical history and physical examination was done. Laboratory investigations were carried out when indicated. Skin diseases were broadly classified into two major categories i.e., infective and noninfective. Among infective, sexually transmitted infections were again separated. Nonblack settlers in the area and UN troops were not included in the study. Data was recorded and analyzed by Microsoft Excel program. Results: 3011 patients belonging to different local tribes having a variety of skin disorders were seen. Patients were of all ages and both sexes ranging from one month to 73 years of age. The Infective skin disorders were seen in 61.7% patients and most prevalent were superficial fungal infections (41.2% followed by, sexually transmitted infections (9.9% and parasitic infections (6.5%. Bacterial and viral infections were rare and so was the scabies. More than 90% parasitic infections were onchocerciasis with full spectrum of cutaneous manifestations. Conclusion: Pattern of skin infections in blacks varies considerably from other ethnic races. Environmental factors, geographical location and free existence of vector for onchocerciasis in West African region, possibly have a significant influence in this variable prevalence.

  9. [Historical presence of invasive fish in the biosphere reserve sierra de Huautla, Mexico].

    Science.gov (United States)

    Mejía-Mojica, Humberto; de Rodríguez-Romero, Felipe Jesús; Díaz-Pardo, Edmundo

    2012-06-01

    The effects of invasive species on native ecosystems are varied, and these have been linked to the disappearance or decline of native fauna, changes in community structure, modification of ecosystems and as vectors of new diseases and parasites. Besides, the development of trade in species for ornamental use has contributed significantly to the import and introduction of invasive fish in some important areas for biodiversity conservation in Mexico, but the presence of these species is poorly documented. In this study we analyzed the fish community in the Biosphere Reserve Sierra de Huautla by looking at diversity changes in the last 100 years. For this, we used databases of historical records and recent collections for five sites in the Amacuzac river, along the Biosphere Reserve area. We compared the values of similarity (Jaccard index) between five times series (1898-1901, 1945-1953, 1971-1980, 1994-1995 and 2008-2009), and we obtained values of similarity (Bray-Curtis) between the five sites analyzed. In our results we recognized a total of 19 species for the area, nine non-native and ten native, three of which were eliminated for the area. Similarity values between the early days and current records were very low (.27); the major changes in the composition of the fauna occurred in the past 20 years. The values of abundance, diversity and similarity among the sampling sites, indicate the dominance of non-native species. We discuss the role of the ornamental fish trade in the region as the leading cause of invasive introduction in the ecosystem and the possible negative effects that at least four non-native species have had on native fauna and the ecosystem (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys disjunctivus and P pardalis). There is an urgent need of programs for registration, control and eradication of invasive species in the Sierra de Huautla Biosphere Reserve and biodiversity protection areas in Mexico.

  10. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Leslie M Roche

    Full Text Available World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus. However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this

  11. Patterns of tree species diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.

    Directory of Open Access Journals (Sweden)

    Ramón Silva-Flores

    Full Text Available Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within species, between species, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different species of Pinus (ca. 22% on the whole, 54 species of Quercus (ca. 9-14%, 7 species of Arbutus (ca. 50% and many other trees species. The objectives of this study were to model how tree species diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum tree species diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of tree species are generally

  12. Nuevo Rowlandius Reddell & Cokendolpher, 1995 (Schizomida: Hubbardiidae de la Sierra San Luis, Venezuela noroccidental

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    Luis F. de Armas

    2009-01-01

    Full Text Available Se describe un nuevo esquizómido del género Rowlandius Reddell & Cokendolpher, 1995, proveniente de la Sierra de San Luis, Estado Falcón, en Venezuela noroccidental. Rowlandius arduus sp. n. se caracteriza por el dedo móvil del quelícero con un diminuto diente subdistal, una débil eminencia dorsoposterior en el segmento abdominal XII del macho y espermatecas constituidas por dos pares de lóbulos largos y sinuosos, tenuemente quitinizados, sin bulbo terminal notable. Su asignación al género Rowlandius es tentativa, pues posee varios caracteres que no concuerdan plenamente con el mismo, sin embargo la carencia de caracteres sinapomórficos limita su asignación a otro género. Este es el primer registro del género para Venezuela y la tercera especie suramericana conocida.A new species of the genus Rowlandius Reddell & Cokendolpher, 1995 is described from Sierra San Luis, Falcón State, northwestern Venezuela. Rowlandius arduus sp. n. may be characterized by having movable finger of chelicerae with a diminute sub-distal tooth, male with a poorly developed dorsal eminence on abdominal segment XII, and female with two pairs of weakly sclerotized, sinuous spermathecal lobes, without conspicuous terminal lobe. It is assigned to Rowlandius tentatively, because some characters are not congruent with this genus, nevertheless the absence of synapomorphic characters limits its inclusion in other one. This is the first record of the genus from Venezuela, and the third South American species described.

  13. Forest management effects on snow, runoff and evapotranspiration in Sierra Nevada mixed-conifer headwater catchments

    Science.gov (United States)

    Ray, R. L.; Saksa, P. C.; Bales, R. C.; Conklin, M. H.

    2012-12-01

    We used intensive field measurements and data-intensive hydro-ecological modeling to investigate the impact of forest vegetation management on the sensitivity of snow accumulation, evapotranspiration and discharge at seven headwater catchments in the Sierra Nevada. Catchments are located in dense mixed-conifer forest, at elevations of 1500 - 2100 m, and receive a mix of rain and snow precipitation. Management scenarios for reducing forest density by uniform thinning and forest clearings were implemented in the Regional Hydro-ecological Simulation System (RHESSys). Results obtained using inherent model equations to separate total precipitation into snow and rain underestimated snow water content in some of the catchments, requiring manual input of snow and rain for accurate simulations. Modeling precipitation phase accurately was critical for the current forest condition, as the change in vegetation has differing effects on rain, snow and snowmelt. Results using RHESSys show that light, uniform thinning alone (<20% canopy) may not be enough to change water yield significantly, but this threshold of canopy reduction is lowered by creating gaps in the forest alone or in combination with uniform thinning, and has potential to measurably increase water yield beyond background variation. Clarifying these specific impacts of forest vegetation on snow processes and water yield is essential for simulating forest management in the Sierra Nevada and it shows the forest structure has significant influence on the catchment water balance. However, modifying forest canopy density and canopy cover to calculate average levels of snow water equivalent at a basin-scale may not be detailed enough to incorporate all the complex forest structure effects on snow processes in mountain watersheds.

  14. Análisis comparativo de la composición de tres comunidades de Squamata de la Sierra Grande de Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Martori, Ricardo

    1994-01-01

    Full Text Available The differences and similarities of lizard assemblages can be explaned by historical or ecological factors or by the interaction of both. To examine these hypothesis we selected three communities with similar environmental influences in the Sierra Grande de Córdoba (Argentina. The sites selected where: Villa Las Rosas (31°56', 65°03', dep. San Javier on the west side of the Sierra, Tanti (310,22, 64°36' dep. Punilla on the east side of the Sierra and Achiras (33°10', 64°59' dep. Rio Cuarto on the southem extreme of the Sierra. All these sites have more than eight species of lizards. The diversity of each site is described and the novelties, sustitutions and absences for each locality are discussed and compared with three external communities. A phylogenetic hypothesis of the species involved in this study is need to resolve the biogeographic problems.

  15. NOAA TIFF Image - 1 m Backscatter Mosaic of Abrir La Sierra Bank, PR (2007) collected using a SeaBat Reson 8124 (200 kHz) multibeam echosounder

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1 meter resolution backscatter mosaic of the Abrir La Sierra Bank off the coast of western Puerto Rico, collected using a SeaBat Reson 8124...

  16. NOAA TIFF Image - 1 m Backscatter Mosaic of Abrir La Sierra Bank, PR (2007) collected using a Kongsberg EM 1002 (95 kHz) multibeam echosounder

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1 meter resolution backscatter mosaic of the Abrir La Sierra Bank off the coast of western Puerto Rico, collected using a Kongsberg EM 1002...

  17. Effects of Climate and Fuels Management on Wildfire Occurrence, Size, Severity and Emissions in the Sierra Nevada

    Science.gov (United States)

    Westerling, A. L.; Fites, J. A.; Keyser, A.

    2015-12-01

    Annual wildfire burned area in federally managed Sierra Nevada forests has increased by more than 10,000 ha per decade since the early 1970s. At the same time, recent years have seen some extremely large fires compared to the historical record, with significant areas of moderate to high severity fire (e.g., McNally 2002, Rim 2013, King 2014 fires). Changes to fuels and fire regimes due to fire suppression and land use, as well as warming temperatures and the occurrence of drought, are thought to be significant factors contributing to increased risks of large, severe fires in Sierra Nevada forests. Over 70% of the vegetated area in federally managed forests in the Sierra Nevada is classified as having altered fuels and fire regimes, while average annual temperature in the Sierra Nevada has been above the long term mean for all but four years in the past two decades. As climate is expected to continue warming for decades to come, we explored fuels management scenarios as the primary tools available to modify risks of large, severe wildfires. We developed experimental statistical models of fire occurrence, fire size, and high severity burned area, to explore the interaction between climate and altered fuels conditions. These models were applied to historical climate conditions, a sample of future climate projections, and to both current fuels conditions and a range of scenarios for fuels treatments. Emissions from wildfires were estimated using the Fire Inventory from the National Center for Atmospheric Research. Our models project that average annual burned area in the Sierra Nevada will more than double by mid-century. Similarly, particulate and other pollution emissions from Sierra Nevada wildfires are projected to more than double, even if future fire severity does not change. Fuels treatment scenarios significantly reduced simulated future burned area and emissions below untreated projections. High severity burned area responded to both climate and fuels

  18. Estructura de los encinares de la sierra de Santa Rosa, Guanajuato, México Oak forest structure in the Sierra de Santa Rosa range, Guanajuato, Mexico

    Directory of Open Access Journals (Sweden)

    Juan Martínez-Cruz

    2009-04-01

    Full Text Available Se describe la estructura de 4 asociaciones de encinares en el oriente de la sierra de Santa Rosa, Guanajuato, con el método de cuadrantes al punto central (21 transectos, donde se contabilizaron 2 320 individuos arbóreos y arbustivos, que incluyen 36 especies, 22 géneros y 15 familias. La asociación Quercus potosina-Q. castanea (QPC registró la mayor riqueza (29 especies y el menor número de individuos por ha-1 (650. Por el contrario, la asociación de Q. laurina-Q. rugosa (QLR presentó sólo 12 especies, pero la mayor densidad de arbustos por ha-1 (5 593. El índice α de Fisher y el análisis de rarefacción ratificaron que la asociación de QPC es la más diversa. La asociación Q. potosina-Q. eduardii (QPE fue la de mayor equidad. Los índices de Simpson (cualitativo y de Sørensen (cuantitativo coincidieron en que las asociaciones Q. coccolobifolia-QLR y QLR-QPE presentan la mayor diversidad beta. Debido al marcado deterioro que se observa en estos bosques, la heterogeneidad de las asociaciones de encinares respecto a su composición, atributos de estructura y diversidad, deben considerarse en acciones futuras encaminadas a lograr un manejo más sustentable de los recursos naturales que albergan estos bosques, así como acciones particulares de conservación y restauración.The structure of 4 oak associations in the western part of the Sierra de Santa Rosa range in Guanajuato state is described. Oak associations were sampled using the point centered quarter method (21 sites. We censused 2 320 individuals of trees and shrubs belonging to 36 species, in 22 genera and 15 families. Observed species richness (29 was highest in the Quercus potosina-Q. castanea association (QPC but tree density was the lowest (650 individuals/ha. Meanwhile, the Q. laurina-Q. rugosa association (QLR had the least number of observed species (12, but the maximum shrub density (5 593 individual/ ha. The Fisher index for alpha diversity and the rarefaction

  19. Using Power-Sharing to Win a War: The Implementation of the Lomé Agreement in Sierra Leone Wie man Machtteilung benutzt, um einen Krieg zu gewinnen: Die Umsetzung des Lomé-Abkommens in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Helga Malmin Binningsbø

    2009-01-01

    Full Text Available To end the civil war in Sierra Leone the government and the Revolutionary United Front (RUF signed a peace agreement guaranteeing power-sharing in July 1999. Such power-sharing is a widely used, often recommended political arrangement to overcome deep divisions between groups. However, scholars disagree on whether power-sharing causes peace, or, on the contrary, causes continuing violence. One reason for this is the literature’s tendency to neglect how power-sharing is actually put into place. But post-agreement implementation is essential if we are to judge the performance of power-sharing. Therefore, we investigate the role played by power-sharing in terminating the civil war in Sierra Leone. We argue that the government was able to use the peace agreement to pursue its goal of ending the war through marginalising the RUF. Zur Beendigung des Bürgerkriegs in Sierra Leone unterzeichneten die Regierung und die Revolutionary United Front (RUF im Juli 1999 eine Friedensvereinbarung, die Machtteilung garantierte. Machtteilung ist ein verbreitet eingesetztes und häufig empfohlenes politisches Konzept, um die tiefe Spaltung zwischen Konfliktgegnern zu überwinden. In der akademischen Debatte gibt es allerdings keine Übereinstimmung dahingehend, ob Machtteilung zum Frieden führt oder, im Gegenteil, zu einer Fortsetzung der Gewalt. Ein Grund dafür liegt darin, dass die Frage nach der realen Umsetzung von Machtteilungsklauseln in der Literatur tendenziell vernachlässigt wird. Die Bewährung in der Umsetzung ist allerdings ganz wesentlich für die Beurteilung der Stärken des Konzepts. Im vorliegenden Beitrag wird daher die Rolle analysiert, die Machtteilung bei der Beendigung des Krieges in Sierra Leone gespielt hat. Die Autorinnen argumentieren, dass die Regierung die Friedensvereinbarung dazu nutzen konnte, ihr Ziel der Marginalisierung der RUF zu erreichen.

  20. Effect of previous chilling storage on quality loss in frozen (–20 °C sierra (Scomberomorus sierra muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

    Directory of Open Access Journals (Sweden)

    Herlinda Soto-Valdez

    2015-03-01

    Full Text Available Rancidity development during frozen storage (–20 °C of sierra fish (Scomberomorus sierra was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively. Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days on the quality of the frozen fish. Physical (pH and texture and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant. An effect of previous ice storage time was observed on the frozen product (in all treatments. However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle.

  1. Deposition patterns and transport mechanisms for the endocrine disruptor 4-nonylphenol across the Sierra Nevada Mountains, California.

    Science.gov (United States)

    Lyons, Rebecca; Van de Bittner, Kyle; Morgan-Jones, Sean

    2014-12-01

    Dust and particulate distribution patterns are shifting as global climate change brings about longer drought periods. Particulates act as vehicles for long range transport of organic pollutants, depositing at locations far from their source. Nonylphenol, a biodegradation product of nonylphenol polyethoxylate, is a known endocrine disruptor. Nonylphenol polyethoxylate enters the environment as an inert ingredient in pesticide sprays, potentially traveling great distances from its application site. This is of concern when a highly agricultural region, California's Central Valley, lies adjacent to sensitive areas like the Eastern Sierra Nevada Mountains. The distribution and transport mechanisms for 4-nonylphenol were investigated in Eastern Sierra Nevada canyons. Regions close to canyon headwalls showed trace amounts of 4-nonylphenol in surface water, snow, and atmospheric deposition. Exposed areas had yearly average concentrations as high as 9 μg/L. Distribution patterns are consistent with particulate-bound transport. This suggests with increasing drought periods, higher levels of persistent organic pollutants are likely.

  2. Facilitators and barriers related to voluntary counseling and testing for HIV among young adults in Bo, Sierra Leone.

    Science.gov (United States)

    Bhoobun, Shalinee; Jetty, Anuradha; Koroma, Mohamed A; Kamara, Mohamed J; Kabia, Mohamed; Coulson, Reginald; Ansumana, Rashid; Jacobsen, Kathryn H

    2014-06-01

    In 2012, we interviewed a population-based sample of 285 young adult residents (age 18-35 years) of the city of Bo, Sierra Leone, about their attitudes toward and experience with voluntary testing and counseling (VCT) for HIV. In total, 33% of the participants (44% of women and 25% of men) reported having been tested for HIV at least once. More than 85% of those not previously tested indicated a willingness to be tested in the near future, but untested participants were nearly twice as likely as tested participants to report fears about family/partner rejection, job loss, and other potential consequences of testing. More than 90% of participants expressed a high desire for testing privacy, and the majority reported a preference for VCT at a facility far from home where no one would know them. Social barriers to HIV testing remain a challenge for HIV prevention in Sierra Leone. PMID:24203408

  3. Status and understanding of groundwater quality in the Sierra Nevada Regional study unit, 2008: California GAMA Priority Basin Project

    Science.gov (United States)

    Fram, Miranda S.; Belitz, Kenneth

    2014-01-01

    Groundwater quality in the Sierra Nevada Regional (SNR) study unit was investigated as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment Program Priority Basin Project. The study was designed to provide statistically unbiased assessments of the quality of untreated groundwater within the primary aquifer system of the Sierra Nevada. The primary aquifer system for the SNR study unit was delineated by the depth intervals over which wells in the State of California’s database of public drinking-water supply wells are open or screened. Two types of assessments were made: (1) a status assessment that described the current quality of the groundwater resource, and (2) an evaluation of relations between groundwater quality and potential explanatory factors that represent characteristics of the primary aquifer system. The assessments characterize untreated groundwater quality, rather than the quality of treated drinking water delivered to consumers by water distributors.

  4. Hydrological conditions and evaluation of sustainable groundwater use in the Sierra Vista Subwatershed, Upper San Pedro Basin, southeastern Arizona

    Science.gov (United States)

    Gungle, Bruce; Callegary, James B.; Paretti, Nicholas V.; Kennedy, Jeffrey R.; Eastoe, Christopher J.; Turner, Dale S.; Dickinson, Jesse E.; Levick, Lainie R.; Sugg, Zachary P.

    2016-08-18

    This study assessed progress toward achieving sustainable groundwater use in the Sierra Vista Subwatershed of the Upper San Pedro Basin, Arizona, through evaluation of 14 indicators of sustainable use. Sustainable use of groundwater in the Sierra Vista Subwatershed requires, at a minimum, a stable rate of groundwater discharge to, and thus base flow in, the San Pedro River. Many of the 14 indicators are therefore related to long-term or short-term effects on base flow and provide us with a means to evaluate groundwater discharge to and base flow in the San Pedro River. The indicators were based primarily on 10 to 20 years of data monitoring in the subwatershed, ending in 2012, and included subwatershedwide indicators, riparian-system indicators, San Pedro River indicators, and springs indicators.

  5. High-Resolution Climate Change Projections Capture the Elevation Dependence of Warming and Snow Cover Loss in California's Sierra Nevada

    Science.gov (United States)

    Walton, D.; Hall, A. D.; Berg, N.; Schwartz, M. A.; Sun, F.

    2015-12-01

    High-resolution projections of warming and snow cover change are made for California's Sierra Nevada mountain range for the period 2081-2100 using hybrid dynamical-statistical downscaling. First, future climate change projections from five global climate models (GCMs) are downscaled dynamically. The warming signal exhibits a strong elevation dependence that is not captured by common statistical downscaling methods. Variations in the warming are attributed to snow albedo feedback and the blocking effect of the Sierra Nevada, which creates a sharp warming gradient between marine and continental air masses. These two physical processes are incorporated into a simple statistical model that mimics the dynamical model's warming patterns given GCM input. This statistical model is used to produce warming and snow cover loss projections for an ensemble of 35 GCMs. Capturing the elevation dependence is important for many applications of climate change, including surface hydrology, water resources, and ecosystems.

  6. Search for an annual modulation of dark-matter signals with a germanium spectrometer at the Sierra Grande Laboratory

    CERN Document Server

    Abriola, D; Brodzinski, R L; Collar, J I; Gregorio, D E D; Farach, H A; García, E; Gattone, A O; Guérard, C K; Hasenbalg, F; Huck, H; Miley, H S; Morales, A; Morales, J; De Solorzano, A O; Puimedón, J; Reeves, J H; Salinas, A; Sarsa, M L; Villar, J A

    1999-01-01

    Data collected during three years with a germanium spectrometer at the Sierra Grande underground laboratory have been analyzed for distinctive features of annual modulation of the signal induced by WIMP dark matter candidates. The main motivation for this analysis was the recent suggestion by the DAMA/NaI Collaboration that a yearly modulation signal could not be rejected at the 90% confidence level when analyzing data obtained with a high-mass low-background scintillator detector. We performed two different analyses of the data: First, the statistical distribution of modulation-significance variables (expected from an experiment running under the conditions of Sierra Grande) was compared with the same variables obtained from the data. Second, the data were analyzed in energy bins as an independent check of the first result and to allow for the possibility of a crossover in the expected signal. In both cases no statistically significant deviation from the null result was found, which could support the hypothe...

  7. Asentamientos humanos y caracterización de la diversidad cultural en la sierra nevada de santa marta

    Directory of Open Access Journals (Sweden)

    Álvaro Osorio Santos

    2014-02-01

    Full Text Available Este artículo se presenta como una reconstrucción general de la historia prehispánico de la Sierra Nevada de Santa Marta y sus. En esta medida se describen las implicaciones históricas y culturales en la conformación de las comunidades habi tan tes del sector geográfico. Se aborda la historia desde los primeros pobladores pasando por la época de la colonia, la república, el siglo XX y sus repercusiones en la coyuntura actual. Con ello, se pretende que los estamentos gubernamentales tengan en cuenta las dimensiones humanas y cosmogonías de los ind ígenas pobladores de la Sierra Nevada a la hora de imponer e implementar planes y manejos en el resguardo de dichos grupos.

  8. Microfades del Cretácico medio y superior de la Sierra de Chiapas (SE México)

    OpenAIRE

    Rosales, C.; Bermúdez, J.; Aguilar, M.

    1996-01-01

    Based on the micropaleontologic study of the carbonate rocks from the Sierra de Chiapas (SE Mexico) ten microfacies are recognized. They correspond mainly to shallow carbonates with some deeper environments toward the top of the sequence. The age of the strata ranges from Cenomanian to Maastrichtian, including some gaps such as that corresponding to subaereal exposure in Cenomanian times and that for Santonian-Early Campanian which represents a regional discontinuity

  9. Analysis of security sector reform in post-conflict Sierra Leone : a comparison of current versus historical capabilities

    OpenAIRE

    Skora, Patrick W,

    2010-01-01

    Security Sector Reform (SSR) is a holistic approach to nation building that focuses on building strong police, military and justice systems that adhere to the rule of law and have a firm commitment to operating under democratically elected civilian governance. The British effort in conducting SSR is, to date, the most comprehensive effort that has been conducted. While UK and international involvement remains high in Sierra Leone, the security sector has operated independently since the r...

  10. Remote Sensing Analysis of the Sierra Blanca (Faskin Ranch) Low-Level Radioactive Waste Disposal Site, Hudspeth County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    LeMone, D. V.; Dodge, R.; Xie, H.; Langford, R. P.; Keller, G. R.

    2002-02-26

    Remote sensing images provide useful physical information, revealing such features as geological structure, vegetation, drainage patterns, and variations in consolidated and unconsolidated lithologies. That technology has been applied to the failed Sierra Blanca (Faskin Ranch) shallow burial low-level radioactive waste disposal site selected by the Texas Low-Level Radioactive Waste Disposal Authority. It has been re-examined using data from LANDSAT satellite series. The comparison of the earlier LANDSAT V (5/20/86) (30-m resolution) with the later new, higher resolution ETM imagery (10/23/99) LANDSAT VII data (15-m resolution) clearly shows the superiority of the LANDSAT VII data. The search for surficial indications of evidence of fatal flaws at the Sierra Blanca site utilizing was not successful, as it had been in the case of the earlier remote sensing analysis of the failed Fort Hancock site utilizing LANDSAT V data. The authors conclude that the tectonic activity at the Sierra Blanca site is much less recent and active than in the previously studied Fort Hancock site. The Sierra Blanca site failed primarily on the further needed documentation concerning a subsurface fault underneath the site and environmental justice issues. The presence of this fault was not revealed using the newer LANDSAT VII data. Despite this fact, it must be remembered that remote sensing provides baseline documentation for determining future physical and financial remediation responsibilities. On the basis of the two sites examined by LANDSAT remote sensing imaging, it is concluded that it is an essential, cost-effective tool that should be utilized not only in site examination but also in all nuclear-related facilities.

  11. Morfología comparada de los dientes humanos fósiles de Ibeas (Sierra de Atapuerca, Burgos)

    OpenAIRE

    Bermúdez de Castro, J. M.

    1987-01-01

    This paper contains a morphological and comparative study of 68 human fossil teeth recovered from the "Sima de los Huesos" site of the Cueva Mayor-Cueva del Silo karst system (Sierra de Atapuerca, Ibeas de Juarros, Burgos). The morphology of the Ibeas teeth conforms with a pattern of expansion of the anterior dentition characterizing all the Middle Pleistocene human populations, and with a pattern of structural reduction of the posterior teeth characterizing the European population of that pe...

  12. Lassa hemorrhagic fever in a late term pregnancy from northern Sierra Leone with a positive maternal outcome: case report.

    Science.gov (United States)

    Branco, Luis M; Boisen, Matt L; Andersen, Kristian G; Grove, Jessica N; Moses, Lina M; Muncy, Ivana J; Henderson, Lee A; Schieffellin, John S; Robinson, James E; Bangura, James J; Grant, Donald S; Raabe, Vanessa N; Fonnie, Mbalu; Zaitsev, Eleina M; Sabeti, Pardis C; Garry, Robert F

    2011-01-01

    Lassa fever (LF) is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW) in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and real time characterization of an acute hemorrhagic LF case at KGH LFW. This case report focuses on a third trimester pregnant Sierra Leonean woman from the historically non-endemic Northern district of Tonkolili who survived the illness despite fetal demise. Employed in this study were newly developed recombinant LASV Antigen Rapid Test cassettes and dipstick lateral flow immunoassays (LFI) that enabled the diagnosis of LF within twenty minutes of sample collection. Deregulation of overall homeostasis, significant hepatic and renal system involvement, and immunity profiles were extensively characterized during the course of hospitalization. Rapid diagnosis, prompt treatment with a full course of intravenous (IV) ribavirin, IV fluids management, and real time monitoring of clinical parameters resulted in a positive maternal outcome despite admission to the LFW seven days post onset of symptoms, fetal demise, and a natural still birth delivery. These studies solidify the growing rapid diagnostic, treatment, and surveillance capabilities at the KGH LF Laboratory, and the potential to significantly improve the current high mortality rate caused by LF. As a result of the growing capacity, we were also able to isolate Lassa virus (LASV) RNA from the patient and perform Sanger sequencing where we found significant genetic divergence from commonly circulating Sierra Leonean strains, showing potential for the discovery of a newly emerged LASV strain with expanded geographic distribution

  13. Lassa hemorrhagic fever in a late term pregnancy from northern sierra leone with a positive maternal outcome: case report

    OpenAIRE

    Bangura James J; Robinson James E; Schieffellin John S; Henderson Lee A; Muncy Ivana J; Moses Lina M; Grove Jessica N; Andersen Kristian G; Boisen Matt L; Branco Luis M; Grant Donald S; Raabe Vanessa N; Fonnie Mbalu; Sabeti Pardis C; Garry Robert F

    2011-01-01

    Abstract Lassa fever (LF) is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW) in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and rea...

  14. Lassa hemorrhagic fever in a late term pregnancy from northern sierra leone with a positive maternal outcome: case report

    Science.gov (United States)

    2011-01-01

    Lassa fever (LF) is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW) in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and real time characterization of an acute hemorrhagic LF case at KGH LFW. This case report focuses on a third trimester pregnant Sierra Leonean woman from the historically non-endemic Northern district of Tonkolili who survived the illness despite fetal demise. Employed in this study were newly developed recombinant LASV Antigen Rapid Test cassettes and dipstick lateral flow immunoassays (LFI) that enabled the diagnosis of LF within twenty minutes of sample collection. Deregulation of overall homeostasis, significant hepatic and renal system involvement, and immunity profiles were extensively characterized during the course of hospitalization. Rapid diagnosis, prompt treatment with a full course of intravenous (IV) ribavirin, IV fluids management, and real time monitoring of clinical parameters resulted in a positive maternal outcome despite admission to the LFW seven days post onset of symptoms, fetal demise, and a natural still birth delivery. These studies solidify the growing rapid diagnostic, treatment, and surveillance capabilities at the KGH LF Laboratory, and the potential to significantly improve the current high mortality rate caused by LF. As a result of the growing capacity, we were also able to isolate Lassa virus (LASV) RNA from the patient and perform Sanger sequencing where we found significant genetic divergence from commonly circulating Sierra Leonean strains, showing potential for the discovery of a newly emerged LASV strain with expanded geographic distribution

  15. Lassa hemorrhagic fever in a late term pregnancy from northern sierra leone with a positive maternal outcome: case report

    Directory of Open Access Journals (Sweden)

    Bangura James J

    2011-08-01

    Full Text Available Abstract Lassa fever (LF is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and real time characterization of an acute hemorrhagic LF case at KGH LFW. This case report focuses on a third trimester pregnant Sierra Leonean woman from the historically non-endemic Northern district of Tonkolili who survived the illness despite fetal demise. Employed in this study were newly developed recombinant LASV Antigen Rapid Test cassettes and dipstick lateral flow immunoassays (LFI that enabled the diagnosis of LF within twenty minutes of sample collection. Deregulation of overall homeostasis, significant hepatic and renal system involvement, and immunity profiles were extensively characterized during the course of hospitalization. Rapid diagnosis, prompt treatment with a full course of intravenous (IV ribavirin, IV fluids management, and real time monitoring of clinical parameters resulted in a positive maternal outcome despite admission to the LFW seven days post onset of symptoms, fetal demise, and a natural still birth delivery. These studies solidify the growing rapid diagnostic, treatment, and surveillance capabilities at the KGH LF Laboratory, and the potential to significantly improve the current high mortality rate caused by LF. As a result of the growing capacity, we were also able to isolate Lassa virus (LASV RNA from the patient and perform Sanger sequencing where we found significant genetic divergence from commonly circulating Sierra Leonean strains, showing potential for the discovery of a newly emerged LASV strain with expanded geographic

  16. Mapping Webs of Information, Conversation, and Social Connections: Evaluating the Mechanics of Collaborative Adaptive Management in the Sierra Nevada Forests

    OpenAIRE

    Lei, Shufei

    2014-01-01

    Managing within social-ecological systems at the landscape scale, such as in the national forests of the Sierra Nevada of California, is challenging to natural resource managers (e.g. the U.S. Forest Service) due to the uncertainties in natural processes and the complexities in social dynamics. Collaborative adaptive management (CAM) has been recently adopted as a viable strategy to diminish uncertainties in natural processes through iterative policy experimentations and adaptations, as well ...

  17. Evaluating the Spatial Distribution of Toxic Air Contaminants in Multiple Ecosystem Indicators in the Sierra Nevada-Southern Cascades

    Science.gov (United States)

    Nanus, L.; Simonich, S. L.; Rocchio, J.; Flanagan, C.

    2013-12-01

    Toxic air contaminants originating from agricultural areas of the Central Valley in California threaten vulnerable sensitive receptors including surface water, vegetation, snow, sediments, fish, and amphibians in the Sierra Nevada-Southern Cascades region. The spatial distribution of toxic air contaminants in different ecosystem indicators depends on variation in atmospheric concentrations and deposition, and variation in air toxics accumulation in ecosystems. The spatial distribution of organic air toxics and mercury at over 330 unique sampling locations and sample types over two decades (1990-2009) in the Sierra Nevada-Southern Cascades region were compiled and maps were developed to further understand spatial patterns and linkages between air toxics deposition and ecological effects. Potential ecosystem impacts in the Sierra Nevada-Southern Cascades region include bioaccumulation of air toxics in both aquatic and terrestrial ecosystems, reproductive disruption, and immune suppression. The most sensitive ecological end points in the region that are affected by bioaccumulation of toxic air contaminants are fish. Mercury was detected in all fish and approximately 6% exceeded human consumption thresholds. Organic air toxics were also detected in fish yielding variable spatial patterns. For amphibians, which are sensitive to pesticide exposure and potential immune suppression, increasing trends in current and historic use pesticides are observed from north to south across the region. In other indicators, such as vegetation, pesticide concentrations in lichen increase with increasing elevation. Current and historic use pesticides and mercury were also observed in snowpack at high elevations in the study area. This study shows spatial patterns in toxic air contaminants, evaluates associated risks to sensitive receptors, and identifies data gaps. Future research on atmospheric modeling and information on sources is needed in order to predict which ecosystems are the

  18. The carnivore remains from the Sima de los Huesos Middle Pleistocene site(Sierra de Atapuerca, Spain)

    OpenAIRE

    Torres Pérez-Hidalgo, Trinidad José de

    1997-01-01

    Remains of carnivores from the Sima de los Huesos site representing at least 158 adult individuals of a primitive (i.e., not very speleoid) form of Ursus deningeri Von Reichenau 1906, have been recovered through the 1995 field season. These new finds extend our knowledge of this group in the Sierra de Atapuerca Middle Pleistocene. Material previously classified as Cuoninae indet. is now assigned to Canis lupus and a third metatarsal assigned in 1987 to Panthera cf. gombaszoe...

  19. Relating Modernity, Conflict and Sexual Violence: Discourses of Violence Against Women in Post-War Sierra Leone

    OpenAIRE

    Spencer-Walters, Dayo T.

    2010-01-01

    This paper attempts to bring two spheres of violence against women (VAW), female genital mutilation/cutting and sexual assault, together in conversation against the backdrop of post war Sierra Leone. Within the dynamic sphere of human rights, violence against women has reached a crossroads. While activists have been successful in advocating for women's rights as human rights (focusing particularly on developing and conflict saturated countries), their efforts have, in many cases, reinforced u...

  20. Medicinal plants used in a Totonac community of the Sierra Norte de Puebla: Tuzamapan de Galeana, Puebla, Mexico.

    Science.gov (United States)

    Martinez Alfaro, M A

    1984-07-01

    Totonac Indians, like other aboriginal peoples, use many plants, animals and minerals in treating illness. We collected our information among mountain dwelling Totonacs (totonacos de la Sierra). These Totonacs from the mountain areas are only beginning to be studied from an ethnobotanical viewpoint. Here we report on their herbal remedies and briefly discuss their traditional medicine. Finally, the role of Western medicine in Totonac life is analyzed.

  1. Polychlorinated biphenyls and toxaphene in Pacific tree frog tadpoles (Hyla regilla) from the California Sierra Nevada, USA.

    Science.gov (United States)

    Angermann, Jeffrey E; Fellers, Gary M; Matsumura, Fumio

    2002-10-01

    Pacific tree frog (Hyla regilla) tadpoles were collected throughout the Sierra Nevada mountain range, California, USA, in 1996 and 1997 and analyzed for the presence of polychlorinated biphenyls (PCBs) and toxaphene. Whole-tadpole sigma PCB levels ranged from 244 ng/g (wet wt) at lower elevations on the western slope to 1.6 ng/g high on the eastern slope, whereas sigma toxaphene levels ranged from 15.6 to 1.5 ng/g. Linear regression of PCB and toxaphene residue levels versus elevation indicated a significant relationship, with an r2 value of 0.33 for PCB and 0.45 for toxaphene indicating a significant elevation effect on PCB and toxaphene bioaccumulation in Sierra Nevada H. regilla. Tadpole samples from sites in east-facing versus west-facing drainage basins showed significant differences in PCB and toxaphene residue levels, suggesting the possibility of a rain-shadow effect in the long-range atmospheric transport of these contaminants to the Sierra Nevada Mountains. PMID:12371500

  2. Floristic and structural characterization of the main forest types in the Taraira Sierra (Department of the Vaupes)

    International Nuclear Information System (INIS)

    The Floristic and structural characterization of the main forest types in the Taraira Sierra, it was carried out to give to know the forests that exist there, since there were not preliminary studies on this ecosystem, and to enlarge the knowledge on the forests of the Colombian Guayana. For the composition study and it structures of the vegetation, three parcels of study of 0.05 hectares settled down, 10m x 50m each one; two in high Catinga and one in the Arbustiva; likewise they were traveled by different places of the Sierra to collect vegetable material. According to the floristic composition, to the covering analysis, and to the Sorensen index (Cordoba, 1995) they were defined three communities, the first of them in Catinga arbustiva, Clusia spathulaefolia - Retiniphyllum truncatum that is characterized to reach heights until of 10 meters, on sandy soils with inferior slope to 7%. In the high Catinga they were two communities, Micrandra sprucei - amazon Poecilanthe and Micrandra sprucei - Tovomita clarkii, which are characterized to present a superior stratum that reaches the 20 meters high. The Taraira Sierra, makes part of the high-priority of conservation areas due to its wealth of species as much animals as vegetables, to its high endemism that is developed on poor and fragile soils of the Guianese shield and to that this ecosystem is in risk, due to the mining exploitation

  3. Effect of Tree-to-Shrub Type Conversion in Lower Montane Forests of the Sierra Nevada (USA) on Streamflow

    Science.gov (United States)

    Tague, Christina L.; Moritz, Max A.

    2016-01-01

    Higher global temperatures and increased levels of disturbance are contributing to greater tree mortality in many forest ecosystems. These same drivers can also limit forest regeneration, leading to vegetation type conversion. For the Sierra Nevada of California, little is known about how type conversion may affect streamflow, a critical source of water supply for urban, agriculture and environmental purposes. In this paper, we examined the effects of tree-to-shrub type conversion, in combination with climate change, on streamflow in two lower montane forest watersheds in the Sierra Nevada. A spatially distributed ecohydrologic model was used to simulate changes in streamflow, evaporation, and transpiration following type conversion, with an explicit focus on the role of vegetation size and aspect. Model results indicated that streamflow may show negligible change or small decreases following type conversion when the difference between tree and shrub leaf areas is small, partly due to the higher stomatal conductivity and the deep rooting depth of shrubs. In contrast, streamflow may increase when post-conversion shrubs have a small leaf area relative to trees. Model estimates also suggested that vegetation change could have a greater impact on streamflow magnitude than the direct hydrologic impacts of increased temperatures. Temperature increases, however, may have a greater impact on streamflow timing. Tree-to-shrub type conversion increased streamflow only marginally during dry years (annual precipitation communities to accurately characterize future hydrologic regimes for the Sierra Nevada. PMID:27575592

  4. Revisiting Emplacement Depths of the Fine Gold Intrusive Suite, West-Central Sierra Nevada

    Science.gov (United States)

    Head, D.; Lackey, J.

    2013-12-01

    The Fine Gold Intrusive Suite (FGIS) is a large intrusive complex in the west central portion of the Sierra Nevada Batholith. Portions of the Sierra Nevada Batholith have been well studied for plutonic pressure and crystallization histories (e.g., Ague and Brimhall, 1988, GSAB), whereas the regional depth of emplacement of the FGIS is not well characterized, and in previous work pressure estimates were not corrected for crystallization temperatures. An accurate sense of barometric gradient in the FGIS is important to evaluate the roles of pre-batholithic structural breaks in controlling magma emplacement levels, and also to reconstruct erosional levels within the Sierra Nevada as a whole. In this study, samples from the FGIS, all from the Bass Lake Tonalite, were petrographically characterized to identify those samples that contain mineral assemblage and crystallization textures appropriate for application of the Aluminum-in-Hornblende barometer of Hammarstrom and Zen (1986) re-calibrated by Anderson and Smith (1995). Analysis of these samples and use of the barometer results in both pressure and temperature of crystallization. FGIS amphiboles are typical magnesio-hornblende on average: K0.2Na0.1Ca1.8[Mg2.4(Al,Fe3+)(0.2-0.6)]Si6.7Ti0.1Al1.3O22(OH)2. Plagioclase compositional ranges are Ab(54-69)An(30-45)Or(0-1). Bass Lake Tonalite data of Ague and Brimhall (1988) were re-calculated for typical plagioclase composition in the Bass Lake Tonalite (Ab62An37Or1), yielding slightly higher crystallization pressures (3.3 to 5.8 kbar) than the original range (2.4 to 4.5 kbar). New FGIS crystallization pressures of 2.6 to 3.5 kbar match the recalculated data well, thus providing larger coverage for estimates of emplacement depth. Apparent temperatures from adjacent amphibole and plagioclase rims were found to be 691 to 767°C. When all barometric data are considered together, and uncertainties of the calibration are factored in, we find that FGIS crystallization pressures

  5. Simulating 3-D radiative transfer effects over the Sierra Nevada mountains using WRF

    Directory of Open Access Journals (Sweden)

    Y. Gu

    2012-08-01

    Full Text Available A surface solar radiation parameterization based on deviations between 3-D and conventional plane-parallel radiative transfer models has been incorporated into the Weather Research and Forecasting (WRF model to understand the solar insolation over mountain/snow areas and to investigate the impact of the spatial and temporal distribution and variation of surface solar fluxes on land-surface processes. Using the Sierra Nevada in the Western United States as a testbed, we show that mountain effect could produce up to −50 to +50 W m−2 deviations in the surface solar fluxes over the mountain areas, resulting in a temperature increase of up to 1 °C on the sunny side. Upward surface sensible and latent heat fluxes are modulated accordingly to compensate for the change in surface solar fluxes. Snow water equivalent and surface albedo both show decreases on the sunny side of the mountains, indicating more snowmelt and hence reduced snow albedo associated with more solar insolation due to mountain effect. Soil moisture increases on the sunny side of the mountains due to enhanced snowmelt, while decreases on the shade side. Substantial differences are found in the morning hours from 8–10 a.m. and in the afternoon around 3–5 p.m., while differences around noon and in the early morning and late afternoon are comparatively smaller. Variation in the surface energy balance can also affect atmospheric processes, such as cloud fields, through the modulation of vertical thermal structure. Negative changes of up to −40 g m−2 are found in the cloud water path, associated with reductions in the surface insolation over the cloud region. The day-averaged deviations in the surface solar flux are positive over the mountain areas and negative in the valleys, with a range between −12~12 W m−2. Changes in sensible and latent heat fluxes and surface skin temperature follow the solar insolation pattern. Differences in the

  6. Spatial Patterns between Regolith Thickness and Forest Productivity in the Southern Sierra CZO

    Science.gov (United States)

    Ferrell, R. M.; Ferrell, D. F.; Hartsough, P. C.; O'Geen, T. T.

    2015-12-01

    Soil in conjunction with underlying weathered bedrock make up what is referred to as regolith, which can be thought of as the substrate that actively contributes water and nutrients to above ground biomass. As a result, regolith thickness is an important regulating factor of forest health and drought tolerance in the Sierra Nevada. Our project examined the relationships between landscape position, regolith thickness, and tree productivity within a sub watershed of the Southern Sierra Critical Zone Observatory. We hypothesized that tree productivity will increase with increasing regolith thickness. Data was collected in the summer of 2015 at sixty-five sites within a 522-ha watershed averaging 1180m in elevation with a MAP of 80cm and a MAT of 11C. Sites were randomly selected from a grid and then stratified in the field to capture representative samples from different landscape positions. Regolith was sampled using a hand auger with attachable extensions. At each site we augered to hard bedrock or a maximum depth of 7.56 m, which ever was shallower. Biomass measurements were made for all conifer species (DBH>20cm) within a 10m radius of the primary auger hole. Tree age was measured from a representative tree for all species in the plots. Preliminary findings suggest that there is a weak correlation between landscape position/slope and regolith thickness, likely due to differences in lithology. It also appears that terrain shape can result in conflicting outcomes: 1. It can focus water to promote physical and chemical weathering and thick regolith; or, 2. water focusing can result in landscape scouring, removing soil and weathered bedrock to create shallow regolith. Productivity appears to be a function of regolith thickness, effective precipitation and landscape position. Water collecting areas in the lower watershed are shallow to bedrock, but typically receive high amounts of effective precipitation resulting in greater tree productivity. Moreover, thick regolith

  7. GuMNet - A high altitude monitoring network in the Sierra de Guadarrama (Madrid, Spain)

    Science.gov (United States)

    Santolaria-Canales, Edmundo

    2016-04-01

    The Guadarrama Monitoring Network (GuMNet) is an observational infrastructure focused on monitoring the state of the atmosphere and the ground in the Sierra de Guadarrama, 50 km NW of the city of Madrid. The network is composed of10 stations ranging from low altitude (900 m a.s.l.) to high mountain climate (2400 m a.s.l.). The atmospheric instrumentation includes sensors for air temperature, air humidity, 4-component net radiation, precipitation, snow height and wind speed and direction. The surface and subsurface infrastructure includes temperature and humidity sensors distributed in 9 trenches up to a maximum of 1 m depth and additionally temperature sensors in 15 PVC cased boreholes down to 20 m and 2 m with a higher vertical resolution close to the surface. All stations are located in exposed open areas except for one site that is in a forested area for measuring air-ground fluxes under forest conditions. High altitude sites are focused on periglacial areas and lower altitude sites have emphasis on pastures. One of the low altitude sites is equipped with a 10 m high tower with 3D sonic anemometers and a CO2/H2O analyzer that will allow the sampling of wind profiles and H2O and CO2 eddy covariance fluxes, important for estimation of CO2 and energy exchanges over complex vegetated surfaces. The network is connected via general packet radio service to the central lab in the Campus of Excellence of Moncloa and management software has been developed to handle the operation of the infrastructure. The data provided by GuMNet will help to improve the characterization of atmospheric variability from turbulent scales to meteorology and climate at high mountain areas, as well as land-atmosphere interactions. The network information aims at meeting the needs of accuracy to be used for biological, agricultural, hydrological, meteorological and climatic investigations in this area with relevance for ecosystem oriented studies. This setup will complement the broader network

  8. Thrust kinematics deduced by primary and secondary magnetizations in the Internal Sierras (Central Pyrenees, Spain)

    Science.gov (United States)

    Oliva, B.; Pueyo, E.

    2003-04-01

    The Central Southern Pyrenees are composed (from N to S) by the Axial Zone (made by several basement-involved nappes; (Gavarnie and Guarga), the Internal Sierras (IS) fold and thrust belt (Larra and Monte Perdido units), the Jaca piggyback basin (turbiditic and molassic) and the External Sierras. Several paleomagnetic studies have been carried out during the last decades in all units except for the IS. Different amounts of rotation were reported, usually from primary directions. This work shows paleomagnetic results derived from recent investigations in the IS. 78 sites were sampled in different thrust sheets in the Larra and Monte Perdido units. Sites were collected in Upper Cretaceous rocks; all of them were homogeneously distributed along the range strike. A N-S section through the Eocene turbiditic basin was also done (9 sites) to link our results to previous data. Stepwise thermal demagnetization every 25-50^oC was performed to unravel the NRM components. Magnetic mineralogy essays (IRM, IST and low temperature) confirm magnetite as the major magnetic carrier. Two paleomagnetic components can be distinguished; A) an intermediate direction unblocking from 350^o to 450^oC and B) a high temperature component (from 500^o -575^oC). The B component displays two polarities and a positive fold and reverse tests whereas the A component shows only reverse polarity and a pervasive negative fold test. The A component has been also found in the Eocene transect. Two major clues help to constrain the remagnetization age; on one hand the deformation age (Early-Middle Eocene in the Larra and Monte Perdido units) and, on the other hand, the age of the turbiditic rocks (Middle Eocene). Therefore the remagnetization process took place by the end of the IS thrust system configuration or in a later period. Since the rotation detected by the A and B components are similar, the rotation age can be constrained as younger than the remagnetization. All these deductions have important

  9. Delays in childhood immunization in a conflict area: a study from Sierra Leone during civil war

    Directory of Open Access Journals (Sweden)

    Gage George N

    2007-12-01

    Full Text Available Abstract Background Sierra Leone has undergone a decade of civil war from 1991 to 2001. From this period few data on immunization coverage are available, and conflict-related delays in immunization according to the Expanded Programme on Immunization (EPI schedule have not been investigated. We aimed to study delays in childhood immunization in the context of civil war in a Sierra Leonean community. Methods We conducted an immunization survey in Kissy Mess-Mess in the Greater Freetown area in 1998/99 using a two-stage sampling method. Based on immunization cards and verbal history we collected data on immunization for tuberculosis, diphtheria, tetanus, pertussis, polio, and measles by age group (0–8/9–11/12–23/24–35 months. We studied differences between age groups and explored temporal associations with war-related hostilities taking place in the community. Results We included 286 children who received 1690 vaccine doses; card retention was 87%. In 243 children (85%, 95% confidence interval (CI: 80–89% immunization was up-to-date. In 161 of these children (56%, 95%CI: 50–62% full age-appropriate immunization was achieved; in 82 (29%, 95%CI: 24–34% immunization was not appropriate for age. In the remaining 43 children immunization was partial in 37 (13%, 95%CI: 9–17 and absent in 6 (2%, 95%CI: 1–5. Immunization status varied across age groups. In children aged 9–11 months the proportion with age-inappropriate (delayed immunization was higher than in other age groups suggesting an association with war-related hostilities in the community. Conclusion Only about half of children under three years received full age-appropriate immunization. In children born during a period of increased hostilities, immunization was mostly inappropriate for age, but recommended immunizations were not completely abandoned. Missing or delayed immunization represents an additional threat to the health of children living in conflict areas.

  10. Observations of the diurnal and seasonal trends in nitrogen oxides in the western Sierra Nevada

    Directory of Open Access Journals (Sweden)

    J. G. Murphy

    2006-06-01

    Full Text Available Observations of speciated nitrogen oxides, namely NO2, total peroxy nitrates (ΣPNs, total alkyl nitrates (ΣANs, and HNO3 by thermal dissociation laser induced fluorescence (TD-LIF, and supporting chemical and meteorological measurements at Big Hill (1860 m, a high elevation site in California's Sierra Nevada Mountains, are described. From May through October, terrain-driven winds in the region routinely bring air from Sacramento, 100 km southwest of the site, upslope over oak and pine forests to Big Hill during the day, while at night, the site often samples clean, dry air characteristic of the free troposphere. Winter differs mainly in that the meteorology does not favour the buildup of Sacramento's pollution over the Sierra Nevada range, and the urban-influenced air that is seen has been less affected by biogenic VOC emissions, resulting in longer lifetime for NO2 and a predominance of the inorganic forms of nitrogen oxides.

    Summertime observations at Big Hill can be compared with those from Granite Bay, a Sacramento suburb, and from the University of California's Blodgett Forest Research Station to examine the evolution of nitrogen oxides and ozone within the urban plume. Nitrogen oxide radicals (NO and NO2, which dominate total nitrogen oxides (NOy at Granite Bay, are rapidly converted into HNO3, ΣPNs, and ΣANs, such that these compounds contribute 29, 30, and 21% respectively to the NOy budget in the plume at Big Hill. Nevertheless, the decreasing concentrations of NO2 as the plume is advected to Big Hill lead to decreases in the production rate of HNO3 and ozone. The data also demonstrate the role that temperature plays in sequestering NO2 into peroxy nitrates, effectively decreasing the rate of ozone production. The important contribution of ΣANs to NOy in the region suggests that they

  11. Timber harvest effect on soil moisture in the southern Sierra Nevada: Is there a measurable impact?

    Science.gov (United States)

    Meadows, M. W.; Bales, R. C.; Conklin, M. H.; Goulden, M.; Hartsough, P. C.; Hopmans, J. W.; Hunsaker, C. T.; Lucas, R. G.; Malazian, A. I.

    2013-12-01

    We monitored soil-moisture storage, evapotranspiration and streamflow in a Sierra Nevada mixed-conifer forest for three post-snowmelt spring/summer seasons during water years 2010-2013. We measured volumetric water content using a COsmic-ray Soil Moisture Observing Systems (COSMOS) to estimate shallow soil-moisture storage and an eddy-covariance flux tower to measure evapotranspiration, covering an area of about 20 ha. Soil-moisture sensors were also strategically placed at depths of 10, 30, 60 and 90 cm at 30 locations in and around the COSMOS and tower footprints. Timber harvest occurred during the summer of 2012, involving uneven-age thinning limited to trees less than 76.2 cm diameter at breast height (DBH). Timber harvest intensity varied by tree size class: approximately 39% of the trees 0 to 25.5 cm DBH, 21% of the trees 25.5 to 50.8 cm DBH, and 4% of trees 50.8-76.2 cm DBH. Merchantable timber removed from the site was about 81-100 cubic m per ha. Annual evapotranspiration was similar for all four years, averaging about 80 cm each year, despite large variability in annual precipitation amounts. Annual evapotranspiration was about 10% lower following harvest. However, 2012 and 2013 were both dry years. Water year 2011 was one of the wettest years on record - approximately 200 cm of precipitation - while 2012 was one of the driest with 70 cm of precipitation. Each year soil desiccation immediately followed snow-cover depletion, dropping from field capacity by about 20% volumetric water content over a 3-month period. The rate of soil-water loss was about the same for all years. In 2012 and 2013 the dates of snow disappearance were 2-3 months earlier than in 2011. About half of the annual total evapotranspiration for 2010-2012 occurred during the 3-month period following snowmelt. Each year, total summer precipitation was only 4-6 cm. Thus soil-water storage derived from snowmelt and rainfall provides much of the moisture for evapotranspiration in the mixed

  12. Diamonds, a resource curse? The case of Kono District in Sierra Leone

    Science.gov (United States)

    Wilson, Sigismond Ayodele

    Using an actor-oriented approach to political ecology integrated with theory on the social production of scale, this dissertation examines the extent to which diamond exploitation constitutes a resource curse in Sierra Leone, with Kono District as a case-study. It uses social survey methods and remote sensing analysis of Landsat images to (1) evaluate the role of Sierra Leone's diamonds in economic development from a historical lens, (2) examine the extent to which a weak regulatory state apparatus makes a rich diamond endowment more of a curse than a blessing, (3) determine whether geographically diffuse and remotely-located diamonds are more a liability than an asset, and (4) assess whether environmental conditions are worse in diamond than in non-diamond chiefdoms. Results of the study showed that the contribution of diamonds to national economic growth declined precipitously following the politicization of diamonds and growing informalization of mining under the leadership of Siaka Stevens. Growing disenchantment combined with grievances over access to diamond resources and rights, culminating in a civil war fuelled by conflict diamonds. Findings indicated that actors capitalized on a weak regulatory state to fulfill their agendas. Illicit diamond exploitation was mainly driven by corruption, economic constraints and perverse economic incentives. Preferential land allocation to industrial mining following World Bank Group-directed national mining policy reforms and the weakness of the state in ensuring companies' adherence to mining clauses precipitated corporation-community conflicts. Study findings showed that the resource curse was acute on diggers who received less than 1 a day unlike their South American counterparts who made at least 7 daily. Results from the study demonstrate that the spatiality of diamonds also contributed to the resource curse. Illicit diamond mining was more acute in remotely located mining sites than in extractive sites closer to

  13. Structure of the Alpujarrides on the southern and eastern border of the Sierra de Lújar

    Directory of Open Access Journals (Sweden)

    Tubía, J. M.

    1990-08-01

    Full Text Available The Alpujarride complex located to the South of the Sierra Nevada and extending between Motril and Adra is formed of five nappes, which in ascending order are: Lújar, Cástaras, Alcázar, Murtas and Adra. These five nappes display a structure that is the result of several overlapping events. Firstly, they reflect a process of ductile shearing associated with a mylonitic foliation and a mylonitic lineation with a N4üo E average orientation. Following this, an episode of translation towards the North has been recorded; this occurred under more superficial conditions and developed gouges and fault breccias. Associated with this episode are locally developed folds, which did not give rise to a mineral blastesis. Afterwards, the late deformations occurred, affecting the whole ofthe ensemble. Of these, the most important are those that originated folds with a N-S axis, verging towards the West and the normal faults. The extensional faults towards the South would be encompassed in this sectionEl Complejo Alpujárride situado al Sur de Sierra Nevada y comprendido entre Motril y Adra, está formado por cinco mantos que son, en orden ascendente: Lújar, Cástaras, Alcázar, Murtas y Adra. Estos cinco mantos presentan una estructuración que es el resultado de varios acontecimientos superpuestos. En primer lugar, reflejan un proceso de cizallamiento dúctil hacia el NE, que lleva asociado una foliación milonítica, de orientación media N4üo E. A continuación se ha registrado un episodio de traslaciones hacia el Norte, en condiciones más superficiales, que desarrolla brechas y harinas de falla. Asociado a este episodio se desarrollan localmente pliegues, que no dan lugar a una blastesis mineral. Con posterioridad se producen las deformaciones tardías, que afectan a todo el conjunto. De ellas, las más sobresalientes son las que originan pliegues de eje N-S, vergentes al Oeste y las fallas normales. Las fallas extensionales hacia el Sur quedar

  14. Observations of the diurnal and seasonal trends in nitrogen oxides in the western Sierra Nevada

    Directory of Open Access Journals (Sweden)

    J. G. Murphy

    2006-01-01

    Full Text Available Observations of speciated nitrogen oxides, namely NO2, total peroxy nitrates (ΣPNs, total alkyl nitrates (ΣANs, and HNO3 by thermal dissociation laser induced fluorescence (TD-LIF, and supporting chemical and meteorological measurements at Big Hill (1860 m, a high elevation site in California's Sierra Nevada Mountains, are described. From May through October, terrain-driven winds in the region routinely bring air from Sacramento, 100 km southwest of the site, upslope over oak and pine forests to Big Hill during the day, while at night, the site often samples clean, dry air characteristic of the free troposphere. Winter differs mainly in that the meteorology does not favour the buildup of Sacramento's pollution over the Sierra Nevada range, and the urban-influenced air that is seen has been less affected by biogenic VOC emissions, resulting in longer lifetime for NO2 and a predominance of the inorganic forms of nitrogen oxides. Summertime observations at Big Hill can be compared with those from Granite Bay, a Sacramento suburb, and from the University of California's Blodgett Forest Research Station to examine the evolution of nitrogen oxides and ozone within the urban plume. Nitrogen oxide radicals (NO and NO2, which dominate total nitrogen oxides (NOy at Granite Bay, are rapidly converted into HNO3, ΣPNs, and ΣANs, such that these compounds contribute 29, 30, and 21% respectively to the NOy budget in the plume at Big Hill. Nevertheless, the decreasing concentrations of NO2 as the plume is advected to Big Hill lead to decreases in the production rate of HNO3 and ozone. The data also demonstrate the role that temperature plays in sequestering NO2 into peroxy nitrates, effectively decreasing the rate of ozone production. The important contribution of ΣANs to NOy in the region suggests that they should be considered with regards to export of NOy from the boundary layer. Nocturnal observations of airmasses characteristic of the

  15. Snowmelt sensitivity to warmer temperatures: a field-validated model analysis, southern Sierra Nevada, California

    Science.gov (United States)

    Musselman, K. N.; Molotch, N. P.; Margulis, S. A.

    2014-12-01

    We present model simulations of climate change impacts on snowmelt processes over a 1600 km2 area in the southern Sierra Nevada, including western Sequoia National Park. The domain spans a 3600 m elevation gradient and ecosystems ranging from semi-arid grasslands to giant sequoia groves to alpine tundra. Three reference years were evaluated: a moderately dry snow season (23% below average SWE), an average snow season (7% above average SWE), and a moderately wet snow season (54% above average SWE). The Alpine3D model was run for the reference years and results were evaluated against data from a multi-scale measurement campaign that included repeated manual snow courses and basin-scale snow surveys, dozens of automated snow depth sensors, and automated SWE stations. Compared to automated measurements, the model represented the date of snow disappearance within two days. Compared to manual measurements, model SWE RMSE values for the average and wet snow seasons were highly correlated (R2=0.89 and R2=0.73) with the distance of SWE measurements from the nearest precipitation gauge used to force the model; no significant correlation was found with elevation. The results suggest that Alpine3D is highly accurate during the melt season and that precipitation uncertainty may critically limit snow model accuracy. The air temperature measured at 19 regional stations for the three reference years was modified by +1°C to +6°C to simulate the impact of warmer temperatures on snowmelt dynamics over the 3600 m elevation gradient. For all years, progressively warmer temperatures caused the seasonal SWE centroid to shift earlier and higher in elevation. At forested middle elevations, 70 - 80% of the present-day snowpack volume is lost in a +2°C scenario; 30 - 40% of that change is a result of precipitation phase shift and the remainder is due to enhanced melt. At all elevations, spring and fall snowpack was most sensitive to warmer temperatures; mid-winter sensitivity was least

  16. Observations of the diurnal and seasonal trends in nitrogen oxides in the western Sierra Nevada

    Science.gov (United States)

    Murphy, J. G.; Day, D. A.; Cleary, P. A.; Wooldridge, P. J.; Cohen, R. C.

    2006-11-01

    Observations of speciated nitrogen oxides, namely NO2, total peroxy nitrates (ΣPNs), total alkyl nitrates (ΣANs), and HNO3 by thermal dissociation laser induced fluorescence (TD-LIF), and supporting chemical and meteorological measurements at Big Hill (1860 m), a high elevation site in California's Sierra Nevada Mountains, are described. From May through October, terrain-driven winds in the region routinely bring air from Sacramento, 100 km southwest of the site, upslope over oak and pine forests to Big Hill during the day, while at night, the site often samples clean, dry air characteristic of the free troposphere. Winter differs mainly in that the meteorology does not favour the buildup of Sacramento's pollution over the Sierra Nevada range, and the urban-influenced air that is seen has been less affected by biogenic VOC emissions, resulting in longer lifetime for NO2 and a predominance of the inorganic forms of nitrogen oxides. Summertime observations at Big Hill can be compared with those from Granite Bay, a Sacramento suburb, and from the University of California's Blodgett Forest Research Station to examine the evolution of nitrogen oxides and ozone within the urban plume. Nitrogen oxide radicals (NO and NO2), which dominate total nitrogen oxides (NOy) at Granite Bay, are rapidly converted into HNO3, ΣPNs, and ΣANs, such that these compounds contribute 29, 30, and 21% respectively to the NOy budget in the plume at Big Hill. Nevertheless, the decreasing concentrations of NO2 as the plume is advected to Big Hill lead to decreases in the production rate of HNO3 and ozone. The data also demonstrate the role that temperature plays in sequestering NO2 into peroxy nitrates, effectively decreasing the rate of ozone production. The important contribution of ΣANs to NOy in the region suggests that they should be considered with regards to export of NOy from the boundary layer. Nocturnal observations of airmasses characteristic of the free troposphere showed lower

  17. Geología y fracturas en la estructura San Pedro, sierra del Alto Río Seco, Sierras Subandinas, provincia de Salta

    Directory of Open Access Journals (Sweden)

    L. Di Marco

    2005-12-01

    Full Text Available La estructura San Pedro se encuentra en el sector central-septentrional de la unidad morfo-estructural de Sierras Subandinas. Su columna estratigráfica esta caracterizada por una compleja historia geológica en la que se superponen varias cuencas sedimentarias con distinto origen, con un relleno total de más de 10.000 m de espesor y desarrolladas en diferentes edades geológicas y bajo distintos ambientes. El yacimiento San Pedrito (niveles devónicos, ubicado en el bloque Acambuco de la cuenca de Tarija puede ser estudiado en principio como un reservorio naturalmente fracturado por el carácter del fracturamiento y fallamiento que presentan las rocas reservorio. Siguiendo esta dirección de pensamiento, se realizó un estudio de fracturas, concentrando la atención en las Formaciones Las Peñas y San Telmo para luego intentar una posible vinculación con las unidades de subsuelo que componen las rocas reservorios del yacimiento San Pedrito. El solapamiento de las zonas de mayor intensidad de fracturas en superficie con las que presentan los mayores valores de producción acumulada del yacimiento San Pedro (niveles carboníferos demuestra que la deformación sufrida por todo el carbonífero como un solo paquete unitario fue desarrollada en forma coherente. Y que si bien los depósitos carboníferos pueden presentar discontinuidades menores, la deformación tectónica no llego a desacoplar mecánicamente los depósitos del Carbonífero superior e inferior. Las fracturas perpendiculares a la estructura (Tipo I hallan sus valores de mayor intensidad en las secciones crestales, y las paralelas a la estructura (Tipo II lo hacen en las secciones del limbo frontal. Este último juego guarda una próxima relación con la curvatura modelada y con los datos de producción acumulada de los pozos pertenecientes al yacimiento San Pedro.

  18. New constraints on the origin of the Sierra Madre de Chiapas (south Mexico) from sediment provenance and apatite thermochronometry

    Science.gov (United States)

    Witt, C.; Brichau, S.; Carter, A.

    2012-12-01

    The timing and source of deformation responsible for formation of the Sierra Madre de Chiapas (south Mexico) are unclear. To address this, apatite fission track and U-Th-He thermochronometry, combined with zircon U-Pb dating, were performed on bedrock and sedimentary samples of the Sierra Madre de Chiapas to discern timing of exhumation and identify sediment source areas. The U-Pb results show that Paleocene-Eocene terrigenous units outcropping at the northern section of the Sierra were mostly derived from Grenville (˜1 Ga) basement whereas the internal sections of the chain yield mainly Permian to Triassic ages (circa 270-230 Ma) typical of the Chiapas massif complex. Grenville-sourced sediments are most probably sourced by the Oaxacan block or the Guichicovi complex and were deposited to the north of the Sierra in a foreland setting related to a Laramide deformation front. Other possibly source areas may be related to metasedimentary units widely documented at the south Maya block such as the Baldi unit. The apatite fission track and U-Th-He data combined with previously published results record three main stages in exhumation history: (1) slow exhumation between 35 and 25 Ma affecting mainly the Chiapas massif complex; (2) fast exhumation between 16 and 9 Ma related to the onset of major strike-slip deformation affecting both the Chiapas massif complex and Chiapas fold-and-thrust belt; and (3) a 6 to 5 Ma period of rapid cooling that affected the Chiapas fold-and-thrust belt, coincident with the landward migration of the Caribbean-North America plate boundaries. These data suggest that most of the topographic growth of the Sierra Madre de Chiapas took place in the middle to late Miocene. The new thermochronological evidence combined with stratigraphic and kinematic information suggests that the left-lateral strike-slip faults bounding the Chiapas fold-and-thrust belt to the west may have accommodated most of the displacement between the North American and

  19. [Presence, abundance and reproductive strategies of ferns in disturbed areas of Sierra Nevada, México].

    Science.gov (United States)

    Rodríguez Romero, Ma Lucía; Zavala Hurtado, José Alejandro; Pacheco, Leticia

    2011-03-01

    Diverse reproductive strategies shown by ferns and lycophytes allow them to colonize a variety of habitats, particularly after the incidence of natural or anthropogenic disturbances. This study assessed the presence, abundance and reproductive strategies of ferns growing in soils of temperate forests with different levels of disturbance at the Sierra Nevada mountain range in the State of Mexico. Vegetation, soil and environmental variables were recorded in 200 m2 permanent plots located in four forest stands. One-Way ANOVA and Canonical Correspondence Analysis resulted in the recognition of three landscape types defined by the degree of environmental alteration: low, moderate and severe. Also, from five soil samples collected in each stand, germination of ferns and lycophytes was induced. A positive relationship was found between the alteration degree and Cheilanthes abundance. Under a low landscape alteration regime, species richness is restricted to Cheilanthes bonariensis, C. marginata and Pellaea ternifolia subsp. ternifolia. The soil is a reservoir of spores of Cheilanthes and Pellaea ternifolia subsp. ternifolia because their spores can remain viable for different time intervals. Apogamy is the usual reproductive strategy of Cheilanthes species in disturbed ecosystems, although these species also show sexual reproduction in natural ecosystems with adequate water availability. Apogamy may be related to a shorter generation time in comparison with a low disturbed ecosystem. On the other hand, Pellaea ternifolia subsp. ternifolia only has sexual reproduction. Apogamy might be related to a faster generation in comparison with a low disturbed ecosystem. PMID:21516659

  20. TRADITIONAL USE OF A PROTECTED SPECIES (Litsea glaucescens Kunth IN THE “SIERRA DEL LAUREL

    Directory of Open Access Journals (Sweden)

    Salvador Martín Medina-Torres

    2011-05-01

    Full Text Available Whenever a natural area is proposed to be a protected area, the information that supports the proposal is usually based on the physical environmental, rather than on the social environment and on the management of natural resource. This study was conducted from May 2004 to June 2005 whit the objective to analyze the process of exploitation of Mexican Bay Leaf (Litsea glaucescens Kunth in rural communities of Sierra del Laurel, a priority area in the state of Aguascalientes, México. Thirteen semi-structured interview were applied for local collectors and seven more were applied to inhabitants of the region to understand the trends in the use of resource. Three interviews were also applied to environmental officials from federal and local institutions to know about their position regarding the use of the Mexican Bay Leaf. A participative workshop with producers and collectors was conducted to document their opinion on the status of the population of this specie. Trend in utilization of the Mexican Bay Leaf have led it to be in danger of extinction: there is not organization nor legal utilization schemes among collectors that allow regeneration; the lack of institutional coordination, along whit inefficient implementation of laws and other legal instruments to regulate the management of natural resources, has contributed so that users have not adequate risk management procedures.

  1. Short Report: Serological Evidence of Under-Reported Dengue Circulation in Sierra Leone.

    Science.gov (United States)

    de Araújo Lobo, Jaime M; Mores, Christopher N; Bausch, Daniel G; Christofferson, Rebecca C

    2016-04-01

    Dengue virus (DENV) is thought to have emerged from a sylvatic cycle in Africa but has since become adapted to an urban-centric transmission cycle. These urban areas include villages in West Africa where DENV is not often routinely considered for patients presenting with febrile illnesses, as other endemic diseases (malaria, Lassa fever, e.g.) present with similar non-specific symptoms. Thus, dengue is likely under diagnosed in the region. These plaque reduction neutralization test-50 (PRNT50) screening results of patients presenting with fevers of unknown origin (FUO) at a clinic in Kenema, Sierra Leone indicate that all four serotypes of DENV likely circulate in areas surrounding Kenema. Using a more conservative PRNT80 cut-off value, our results still indicate the presence of antibody to all four serotypes in the region. Identifying alternate etiologies of FUOs in this region will assist clinicians in plan-of-care decisions as well as follow-up priorities. This is particularly relevant given the Ebola outbreak in the region, where diagnosis has a range of downstream effects ranging from correct allocation of medical resources, appropriate isolation of patients, and ultimately, a better informed public health sector. PMID:27116605

  2. Timing and new geomorphologic evidence of the last deglaciation stages in Sierra Nevada (southern Spain)

    Science.gov (United States)

    Palacios, David; Gómez-Ortiz, Antonio; Andrés, Nuria; Salvador, Ferrán; Oliva, Marc

    2016-10-01

    The main objective of this research is to improve knowledge of the deglaciation stages in Sierra Nevada (southern Spain) by applying 36Cl cosmogenic exposure dating to 28 samples from moraine and fossil rock glacier boulders and glacial polished surfaces, in 5 glaciated valleys around Veleta Peak (3396 m asl; 37°03‧02″N 3°20‧54″W). The results show that shortly before the Last Glacial Maximum (LGM) and during the LGM, the heads of the glacial valleys were occupied by ice tongues, with possible glacial transfluence between the valleys. After 19 ka, a major glacial regression started, but glaciers during the Oldest Dryas (OD) expanded again and refilled the valley bottoms. The glacial advances of the pre-LGM, LGM and OD formed polygenic moraine systems. During the Bølling-Allerød the glaciers receded and probably disappeared. Thereafter, the valley bottoms remained ice-free. During the Younger Dryas (YD) small glaciers developed again, but only in cirques shaped on east-facing slopes. Subsequently, these glaciers started retreating towards their valley heads and finally disappeared completely. With the onset of the Holocene, rock glaciers developed inside the deglaciated cirques on the eastern slopes of some valleys, but only under the most active and protected headwalls did large complex rock glaciers develop and remained active until the mid-Holocene.

  3. Air Pollution and Watershed Research in the Central Sierra Nevada of California: Nitrogen and Ozone

    Directory of Open Access Journals (Sweden)

    Carolyn Hunsaker

    2007-01-01

    Full Text Available Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3 and nitrogenous (N air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100–2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes.

  4. The Effect of Community-Based Prevention and Care on Ebola Transmission in Sierra Leone

    Science.gov (United States)

    Rogers, Braeden; Lee, Sylvia; Bhatnagar, Aarunima; Wolman, Yaron; Monasch, Roeland; Hipgrave, David; Salama, Peter; Kucharski, Adam; Chopra, Mickey

    2016-01-01

    Objectives. To examine the acceptability, use, effects on early isolation, and contribution to Ebola virus disease (EVD) transmission of Community Care Centers (CCCs), which were rapidly deployed in Sierra Leone during an accelerated phase of the 2014–2015 EVD epidemic. Methods. Focus group discussions, triads, and key informant interviews assessed acceptability of the CCCs. Facility registers, structured questionnaires, and laboratory records documented use, admission, and case identification. We estimated transmission effects by comparing time between symptom onset and isolation at CCCs relative to other facilities with the national Viral Hemorrhagic Fever data set. Results. Between November 2014 and January 2015, 46 CCCs were operational. Over 13 epidemic weeks, 6129 patients were triaged identifying 719 (12%) EVD suspects. Community acceptance was high despite initial mistrust. Nearly all patients presented to CCCs outside the national alert system. Isolation of EVD suspects within 4 days of symptoms was higher in CCCs compared with other facilities (85% vs 49%; odds ratio = 6.0; 95% confidence interval = 4.0, 9.1), contributing to a 13% to 32% reduction in the EVD reproduction number (Ro). Conclusions. Community-based approaches to prevention and care can reduce Ebola transmission. PMID:26890176

  5. Navigating Crisis and Chronicity in the Everyday: Former Child Soldiers in Urban Sierra Leone

    Directory of Open Access Journals (Sweden)

    Myriam Denov

    2013-09-01

    Full Text Available The aftermath of war is typically referred to as ‘post-conflict’, often insinuating a stage of relative calm following a period of armed violence, upheaval and strife. However, the assumption that the post-war context brings forth peace, prosperity and stability negates the reality that conflict, violence and poverty may become embedded in the post-war social fabric. Following its decade long civil war, Sierra Leone continues to contend with a political, social and economic reality marked by widespread poverty, violence, and devastated health and social service systems, highlighting that for many, ‘crisis’ has in fact become chronic and endemic in the post-war period. Drawing on interviews with 11 former child soldiers living in an urban settlement, this article underscores the blurred distinction between periods of war and peace. Moreover, using the concept of social navigation, the paper explores the strategies the youth deliberately and tactfully employed in negotiating a volatile post-conflict terrain. Their narratives reveal their active, rather than passive, efforts in fostering their own social, economic and physical wellbeing in light of ever-changing, and unstable circumstances.

  6. [Mammals' camera-trapping in Sierra Nanchititla, Mexico: relative abundance and activity patterns].

    Science.gov (United States)

    Monroy-Vilchis, Octavio; Zarco-González, Martha M; Rodríguez-Soto, Clarita; Soria-Díaz, Leroy; Urios, Vicente

    2011-03-01

    Species conservation and their management depend on the availability of their population behavior and changes in time. This way, population studies include aspects such as species abundance and activity pattern, among others, with the advantage that nowadays new technologies can be applied, in addition to common methods. In this study, we used camera-traps to obtain the index of relative abundance and to establish activity pattern of medium and large mammals in Sierra Nanchititla, Mexico. The study was conducted from December 2003 to May 2006, with a total sampling effort of 4 305 trap-days. We obtained 897 photographs of 19 different species. Nasua narica, Sylvilagus floridanus and Urocyon cinereoargenteus were the most abundant, in agreement with the relative abundance index (RAI, number of independent records/100 trap-days), and according to previous studies with indirect methods in the area. The activity patterns of the species showed that 67% of them are nocturnal, except Odocoileus virginianus, Nasua narica and others. Some species showed differences with previously reported patterns, which are related with seasonality, resources availability, organism sex, principally. The applied method contributed with reliable data about relative abundance and activity patterns. PMID:21516657

  7. Characterizing the Networks of Digital Information that Support Collaborative Adaptive Forest Management in Sierra Nevada Forests

    Science.gov (United States)

    Lei, Shufei; Iles, Alastair; Kelly, Maggi

    2015-07-01

    Some of the factors that can contribute to the success of collaborative adaptive management—such as social learning, open communication, and trust—are built upon a foundation of the open exchange of information about science and management between participants and the public. Despite the importance of information transparency, the use and flow of information in collaborative adaptive management has not been characterized in detail in the literature, and currently there exist opportunities to develop strategies for increasing the exchange of information, as well as to track information flow in such contexts. As digital information channels and networks have been increased over the last decade, powerful new information monitoring tools have also been evolved allowing for the complete characterization of information products through their production, transport, use, and monitoring. This study uses these tools to investigate the use of various science and management information products in a case study—the Sierra Nevada Adaptive Management Project—using a mixed method (citation analysis, web analytics, and content analysis) research approach borrowed from the information processing and management field. The results from our case study show that information technologies greatly facilitate the flow and use of digital information, leading to multiparty collaborations such as knowledge transfer and public participation in science research. We conclude with recommendations for expanding information exchange in collaborative adaptive management by taking advantage of available information technologies and networks.

  8. Social pathways for Ebola virus disease in rural Sierra Leone, and some implications for containment.

    Directory of Open Access Journals (Sweden)

    Paul Richards

    2015-04-01

    Full Text Available The current outbreak of Ebola Virus Disease in Upper West Africa is the largest ever recorded. Molecular evidence suggests spread has been almost exclusively through human-to-human contact. Social factors are thus clearly important to understand the epidemic and ways in which it might be stopped, but these factors have so far been little analyzed. The present paper focuses on Sierra Leone, and provides cross sectional data on the least understood part of the epidemic-the largely undocumented spread of Ebola in rural areas. Various forms of social networking in rural communities and their relevance for understanding pathways of transmission are described. Particular attention is paid to the relationship between marriage, funerals and land tenure. Funerals are known to be a high-risk factor for infection. It is suggested that more than a shift in awareness of risks will be needed to change local patterns of behavior, especially in regard to funerals, since these are central to the consolidation of community ties. A concluding discussion relates the information presented to plans for halting the disease. Local consultation and access are seen as major challenges to be addressed.

  9. Assessment of Community Event–Based Surveillance for Ebola Virus Disease, Sierra Leone, 2015

    Science.gov (United States)

    Crowe, Samuel J.; Jasperse, Joseph; Privette, Grayson; Stone, Erin; Miller, Laura; Hertz, Darren; Fu, Clementine; Maenner, Matthew J.; Jambai, Amara; Morgan, Oliver

    2016-01-01

    In 2015, community event–based surveillance (CEBS) was implemented in Sierra Leone to assist with the detection of Ebola virus disease (EVD) cases. We assessed the sensitivity of CEBS for finding EVD cases during a 7-month period, and in a 6-week subanalysis, we assessed the timeliness of reporting cases with no known epidemiologic links at time of detection. Of the 12,126 CEBS reports, 287 (2%) met the suspected case definition, and 16 were confirmed positive. CEBS detected 30% (16/53) of the EVD cases identified during the study period. During the subanalysis, CEBS staff identified 4 of 6 cases with no epidemiologic links. These CEBS-detected cases were identified more rapidly than those detected by the national surveillance system; however, too few cases were detected to determine system timeliness. Although CEBS detected EVD cases, it largely generated false alerts. Future versions of community-based surveillance could improve case detection through increased staff training and community engagement. PMID:27434608

  10. Determination of hydraulic conductivities of low permeability materials in the Sierra Ladrones Formation, Albuquerque basin

    Energy Technology Data Exchange (ETDEWEB)

    Planert, C.S.

    1995-06-01

    Low permeability materials in the Sierra Ladrones Formation were sampled and analyzed to determine their hydraulic conductivities using the falling head centrifugation method (fc) as described by Nimmo et al. (1991). The method is similar to the traditional falling head method, only it uses greatly increased centrifugal forces, allowing measurements to make in a relatively short amount of time. Using these measurements, variations in saturated hydraulic conductivities between different sediment types were analyzed using Analysis of Variance (ANOVA). Sampling resulted in useable data chiefly from the clay and silt facies of the formation. The range of conductivities determined are representative of brown and red clays, and silts which make up the overbank deposits of this region. Hydraulic conductivities for these overbank fines were found to range from approximately log K = {minus}9 m/s to log K = {minus}7 m/s. The upper measurement limit of the centrifuge apparatus was determined to be approximately 1.43 {times} 10{sup {minus}7} m/s and the lower limit was approximately 7.6 {times} 10{sup {minus}12} m/s.

  11. Origin of Meter-Size Granite Basins in the Southern Sierra Nevada, California

    Science.gov (United States)

    Moore, James G.; Gorden, Mary A.; Robinson, Joel E.; Moring, Barry C.

    2008-01-01

    Meter-size granite basins are found in a 180-km belt extending south from the South Fork of the Kings River to Lake Isabella on the west slope of the southern Sierra Nevada, California. Their origin has long been debated. A total of 1,033 basins have been inventoried at 221 sites. The basins occur on bedrock granitic outcrops at a median elevation of 1,950 m. Median basin diameter among 30 of the basin sites varies from 89 to 170 cm, median depth is 12 to 63 cm. Eighty percent of the basin sites also contain smaller bedrock mortars (~1-2 liters in capacity) of the type used by Native Americans (American Indians) to grind acorns. Features that suggest a manmade origin for the basins are: restricted size, shape, and elevation range; common association with Indian middens and grinding mortars; a south- and west-facing aspect; presence of differing shapes in distinct localities; and location in a food-rich belt with pleasant summer weather. Volcanic ash (erupted A.D. 1240+-60) in the bottom of several of the basins indicates that they were used shortly before ~760 years ago but not thereafter. Experiments suggest that campfires built on the granite will weaken the bedrock and expedite excavation of the basins. The primary use of the basins was apparently in preparing food, including acorns and pine nuts. The basins are among the largest and most permanent artifacts remaining from the California Indian civilization.

  12. Late Cenzoic rhyolites from the Kern Plateau, southern Sierra Nevada, California.

    Science.gov (United States)

    Bacon, C.R.; Duffield, W.A.

    1981-01-01

    Four late Cenozoic rhyolite domes lie atop the Kern Plateau, 30 to 40km S-SE of Mount Whitney. K-Ar and 40Ar/39Ar dating shows that Monache, Templeton, and Little Templeton Mountains are all about 2.4Ma old; a small dome nearby is approx 0.2Ma old. The three older rhyolites have SiO2 = 73-74% and have steep, fractionated rare earth element (REE) patterns; the youngest has SiO2 = 76% and a concave-upward REE pattern with a large negative Eu anomaly, Monache rhyolite contains the unusual phenocryst assemblage almandine + fayalite + biotite + oligoclase. The 2.4Ma old rocks may be nearly unmodified partial melts of crustal sources, whereas the 0.2Ma old rhyolite may be a product of relatively shallow differentiation. The rhyolites and nearby basalts are coeval with mafic and silicic volcanic rocks in the Coso Range about 40km to the SE. Their generation and eruption may reflect intense tectonic extension at the margin of the Basin and Range province and concomitant relaxation of compressive stress in a W- NW direction, allowing melts to reach the surface in the adjacent Sierra Nevada.-Authors

  13. Auditory capacities in Middle Pleistocene humans from the Sierra de Atapuerca in Spain

    Science.gov (United States)

    Martínez, I.; Rosa, M.; Arsuaga, J.-L.; Jarabo, P.; Quam, R.; Lorenzo, C.; Gracia, A.; Carretero, J.-M.; de Castro, J.-M. Bermúdez; Carbonell, E.

    2004-01-01

    Human hearing differs from that of chimpanzees and most other anthropoids in maintaining a relatively high sensitivity from 2 kHz up to 4 kHz, a region that contains relevant acoustic information in spoken language. Knowledge of the auditory capacities in human fossil ancestors could greatly enhance the understanding of when this human pattern emerged during the course of our evolutionary history. Here we use a comprehensive physical model to analyze the influence of skeletal structures on the acoustic filtering of the outer and middle ears in five fossil human specimens from the Middle Pleistocene site of the Sima de los Huesos in the Sierra de Atapuerca of Spain. Our results show that the skeletal anatomy in these hominids is compatible with a human-like pattern of sound power transmission through the outer and middle ear at frequencies up to 5 kHz, suggesting that they already had auditory capacities similar to those of living humans in this frequency range. PMID:15213327

  14. Differences in coprophilous beetle communities structure in Sierra de Minas (Uruguay): a mosaic landscape.

    Science.gov (United States)

    González-Vainer, Patricia; Morelli, E; Defeo, O

    2012-10-01

    Coprophilous beetles represent an abundant and rich group with critical importance in the functioning of terrestrial ecosystems. Most coprophagous beetles have a stenotopic distribution in relation to vegetation types. Because of this, they are usually very sensitive to environmental changes and are considered well suited as bioindicator organisms. The aim of this study was to analyze variations in coprophilous beetle assemblages in natural and anthropogenic habitats. Coprophilous beetle communities were sampled monthly for 1 year using pitfall traps baited with cow dung, in native xeric upland forests, 15-years-old plantations of Pinus elliottii and pastures in Sierra de Minas, Lavalleja, Uruguay. A total of 7,436 beetles were caught and identified to species or morphospecies level. The most abundant families were Aphodiidae, Scarabaeidae, and Staphylinidae. Differences in species richness, abundance, Shannon index, evenness, and dominance were detected between habitats. Abundances of most frequent families were significantly higher in both kinds of forests. Species richness and diversity of Aphodiidae and Staphylinidae were higher in forests, while Scarabaeidae showed the highest richness and diversity in pine plantations. Species composition significantly differed between habitats. Uroxys terminalis Waterhouse and Ataenius perforatus Harold typified the assemblages in native forests and pine plantations and also discriminated both communities because of their differential pattern of abundance between habitats. Typifying species in pastures were Onthophagus hirculus, Ateuchus robustus (Harold), and Ataenius platensis Blanchard. Habitat type had a strong effect on the coprophilous beetle community structure and composition. PMID:23950086

  15. SIERRA Multimechanics Module: Aria User Manual – Version 4.40

    Energy Technology Data Exchange (ETDEWEB)

    Notz, Patrick K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Subia, Samuel Ramirez [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hopkins, Matthew M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moffat, Harry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Noble, David R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Okusanya, Tolulope O. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-05-02

    Aria is a Galerkin finite element based program for solving coupled-physics problems described by systems of PDEs and is capable of solving nonlinear, implicit, transient and direct-to-steady state problems in two and three dimensions on parallel architectures. The suite of physics currently supported by Aria includes thermal energy transport, species transport, and electrostatics as well as generalized scalar, vector and tensor transport equations. Additionally, Aria includes support for manufacturing process flows via the incompressible Navier-Stokes equations specialized to a low Reynolds number (Re < 1) regime. Enhanced modeling support of manufacturing processing is made possible through use of either arbitrary Lagrangian- Eulerian (ALE) and level set based free and moving boundary tracking in conjunction with quasi-static nonlinear elastic solid mechanics for mesh control. Coupled physics problems are solved in several ways including fully-coupled Newton’s method with analytic or numerical sensitivities, fully-coupled Newton- Krylov methods and a loosely-coupled nonlinear iteration about subsets of the system that are solved using combinations of the aforementioned methods. Error estimation, uniform and dynamic ℎ-adaptivity and dynamic load balancing are some of Aria’s more advanced capabilities. Aria is based upon the Sierra Framework.

  16. CDC's Response to the 2014-2016 Ebola Epidemic - Guinea, Liberia, and Sierra Leone.

    Science.gov (United States)

    Dahl, Benjamin A; Kinzer, Michael H; Raghunathan, Pratima L; Christie, Athalia; De Cock, Kevin M; Mahoney, Frank; Bennett, Sarah D; Hersey, Sara; Morgan, Oliver W

    2016-01-01

    CDC's response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa was the largest in the agency's history and occurred in a geographic area where CDC had little operational presence. Approximately 1,450 CDC responders were deployed to Guinea, Liberia, and Sierra Leone since the start of the response in July 2014 to the end of the response at the end of March 2016, including 455 persons with repeat deployments. The responses undertaken in each country shared some similarities but also required unique strategies specific to individual country needs. The size and duration of the response challenged CDC in several ways, particularly with regard to staffing. The lessons learned from this epidemic will strengthen CDC's ability to respond to future public health emergencies. These lessons include the importance of ongoing partnerships with ministries of health in resource-limited countries and regions, a cadre of trained CDC staff who are ready to be deployed, and development of ongoing working relationships with U.S. government agencies and other multilateral and nongovernment organizations that deploy for international public health emergencies. CDC's establishment of a Global Rapid Response Team in June 2015 is anticipated to meet some of these challenges. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html). PMID:27388930

  17. Ten Years of Forest Cover Change in the Sierra Nevada Detected Using Landsat Satellite Image Analysis

    Science.gov (United States)

    Potter, Christopher S.

    2014-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) methodology was applied to detected changes in forest vegetation cover for areas burned by wildfires in the Sierra Nevada Mountains of California between the periods of 1975- 79 and 1995-1999. Results for areas burned by wildfire between 1995 and 1999 confirmed the importance of regrowing forest vegetation over 17% of the combined burned areas. A notable fraction (12%) of the entire 5-km (unburned) buffer area outside the 1995-199 fires perimeters showed decline in forest cover, and not nearly as many regrowing forest areas, covering only 3% of all the 1995-1999 buffer areas combined. Areas burned by wildfire between 1975 and 1979 confirmed the importance of disturbed (or declining evergreen) vegetation covering 13% of the combined 1975- 1979 burned areas. Based on comparison of these results to ground-based survey data, the LEDAPS methodology should be capable of fulfilling much of the need for consistent, low-cost monitoring of changes due to climate and biological factors in western forest regrowth following stand-replacing disturbances.

  18. Calibrating Late Quaternary terrestrial climate signals: radiometrically dated pollen evidence from the southern Sierra Nevada, USA

    Science.gov (United States)

    Litwin, Ronald J.; Smoot, Joseph P.; Durika, Nancy J.; Smith, George I.

    1999-01-01

    We constructed a radiometrically calibrated proxy record of Late Pleistocene and Holocene climate change exceeding 230,000 yr duration, using pollen profiles from two cores taken through age-equivalent dry lakes - one core having greater age control (via 230Th alpha mass-spectrometry) and the other having greater stratigraphic completeness. The better dated of these two serial pollen records (Searles Lake) served as a reference section for improving the effective radiometric age control in a nearby and more complete pollen record (Owens Lake) because they: (1) are situated ~90 km apart in the same drainage system (on, and immediately leeward of, the eastern flank of the Sierra Nevada), and (2) preserved strikingly similar pollen profiles and concordant sequences of sedimentological changes. Pollen assemblages from both lakes are well preserved and diverse, and document serial changes in Late Pleistocene and Holocene plant zone distribution and composition in the westernmost Great Basin; they consist of taxa now inhabiting montane forest, woodland, steppe, and desert-scrub environments. The studied core intervals are interpreted here to be the terrestrial equivalent of marine δ18O stages 1 through 9; these pollen profiles now appear to be among the best radiometrically dated Late Pleistocene records of terrestrial climate change known.

  19. Seasonal biology of Ferrisia gilli (Hemiptera: Pseudococcidae) in California Sierra foothill vineyards.

    Science.gov (United States)

    Wunderlich, Lynn R; Cooper, Monica L; Daane, Kent M

    2013-08-01

    The mealybug Ferrisia gilli Gullan is an emerging pest of wine grapes grown in California's Sierra foothills. A relatively new species, it had previously been recorded as a pest of pistachio, almond, and ornamentals. It was first reported on grape in El Dorado County in 2003 and has since established and spread. Nondestructive monitoring of grape vine sections was conducted in untreated vineyard plots and compared with destructive sampling conducted in grower-treated plots in 2008 and 2009 to determine F. gilli life stage seasonal presence, number of generations, location on the vine during the season, and damage potential to fruit clusters. Two generations were observed to be completed during the season. F. gilli overwintered under the bark at the base of the trunk, trunk, and cordon as second and third instars. Adults were found at the base of emerging shoots (spring) or on and under bark of old and new spurs. Live crawlers were born in June (first generation) and late August to September (second generation), and migrated to leaves to feed before moving to protected locations under bark or into fruit clusters. Lower mealybug densities and fruit damage were recorded on vines with than without insecticide treatment(s). Parasitized mealybugs were collected in low numbers and an Acerophagus sp. was the dominant parasitoid.

  20. First horizontal well opens new gas opportunities in the Sierra Chata Field Neuquen Basin-Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, C.A.; Nilson, G.J.; Acree, J.F.; Del Pino, M.A. [Devon Energy Corp., Calgary, AB (Canada); Anaya, L. [BJ Services Co. USA, Houston, TX (United States)

    2002-07-01

    This paper described the drilling activity surrounding the first horizontal re-entry gas well in the Sierra Chata field in the Neuquen basin in Argentina. In particular, a model forecast was compared with the final results. The re-entry well was originally designed to add gas reserves and to incorporate horizontal well technology to help access the thin sands with low permeability. A numeric simulation of the 1000 m horizontal well was used to predict an initial gas flow rate of 17.7 MMscfd with an estimated final recovery of 7.3 Bscf. This forecast was confirmed following the first year of production. Operational problems, however, were encountered and new solutions were needed to bring the well back on line. The use of an existing well bore saved $1 MM and improved the economics of the project. When re-entering the existing well bore, no new flow line was needed. Given the success of this first re-entry well, it was suggested that this technology can now be used for the Machiline formation which has low productivity for several reasons, including thin sands, low permeability and difficult access via vertical wells. The use of mud logs and resistivity/gamma ray logs while drilling was very important for geological control purposes. It was noted that a measurement while drilling (MWD) tool closer to the bit would have further improved the ability to stay within very thin target zones. 11 refs., 19 figs.