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Sample records for cerro negro sierra

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

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    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

  2. El volcanismo bimodal del volcán cerro Corona, Alta Sierra de Somún Curá, provincia de Río Negro

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    Guadalupe Maro

    2012-03-01

    Full Text Available La Alta Sierra de Somún Curá es uno de los complejos volcánicos terciarios postplateau en el ambiente de la meseta basáltica de Somún Curá, en la Patagonia extrandina. En ella se encuentra el cerro Corona, un volcán en escudo que corresponde al centro de mayor altura en la región. Está construido por rocas efusivas y piroclásticas subordinadas, fundamentalmente traquiandesíticas-basálticas, con variaciones traquíticas tanto en sus flancos como en su cráter. A pesar de la bimodalidad compositional con una importante discontinuidad entre el 54 y 58 % en peso de SiO2, el presente trabajo propone que las traquitas son el producto de la evolución por cristalización fraccionada de las traquiandesitas basálticas, con cierta influencia de recargas máficas a la cámara magmática de acuerdo a la presencia de texturas de desequilibrio en los fenocristales, principalmente de las rocas félsicas.

  3. El volcanismo bimodal del volcán cerro Corona, Alta Sierra de Somún Curá, provincia de Río Negro Bimodal volcanism of the Cerro Corona volcano in the Alta Sierra de Somún Curá (Río Negro province

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    Guadalupe Maro

    2012-03-01

    Full Text Available La Alta Sierra de Somún Curá es uno de los complejos volcánicos terciarios postplateau en el ambiente de la meseta basáltica de Somún Curá, en la Patagonia extrandina. En ella se encuentra el cerro Corona, un volcán en escudo que corresponde al centro de mayor altura en la región. Está construido por rocas efusivas y piroclásticas subordinadas, fundamentalmente traquiandesíticas-basálticas, con variaciones traquíticas tanto en sus flancos como en su cráter. A pesar de la bimodalidad compositional con una importante discontinuidad entre el 54 y 58 % en peso de SiO2, el presente trabajo propone que las traquitas son el producto de la evolución por cristalización fraccionada de las traquiandesitas basálticas, con cierta influencia de recargas máficas a la cámara magmática de acuerdo a la presencia de texturas de desequilibrio en los fenocristales, principalmente de las rocas félsicas.The Cerro Corona is a shield volcano situated in the Alta Sierra de Somún Curá, one of the tertiary volcanic complex that constitute the Meseta de Somún Curá, in the Extrandean Patagonia. It is the highest center in the region and it is compound mainly of basaltic trachyandesites, with trachytic variations on its flanks and crater. Despite the compositional bimodality with an important compositional gap between 54% and 58% in weight in SiO2, this work suggests that trachytes are the product of the evolution of basaltic trachyandesites through fractional crystallization, with some influence of mafic recharge to the magmatic chamber, in agreement with the presence of disequilibrium textures in fenocrystals, essentially in felsic rocks.

  4. Geophysical Investigations of Magma Plumbing Systems at Cerro Negro Volcano, Nicaragua

    Science.gov (United States)

    MacQueen, Patricia Grace

    Cerro Negro near Leon, Nicaragua is a very young (163 years), relatively small basaltic cinder cone volcano that has been unusually active during its short lifespan (recurrence interval 6--7 years), presenting a significant hazard to nearby communities. Previous studies have raised several questions as to the proper classification of Cerro Negro and its relation to neighboring Las Pilas-El Hoyo volcano. Analysis of Bouguer gravity data collected at Cerro Negro has revealed connected positive density anomalies beneath Cerro Negro and Las Pilas-El Hoyo. These findings suggest that eruptions at Cerro Negro may be tapping a large magma reservoir beneath Las Pilas-El Hoyo, implying that Cerro Negro should be considered the newest vent on the Las Pilas-El Hoyo volcanic complex. As such, it is possible that the intensity of volcanic hazards at Cerro Negro may eventually increase in the future to resemble those pertaining to a stratovolcano. Keywords: Cerro Negro; Las Pilas-El Hoyo; Bouguer gravity; magmatic plumbing systems; potential fields; volcano.

  5. Investigating the subsurface connection beneath Cerro Negro volcano and the El Hoyo Complex, Nicaragua

    Science.gov (United States)

    Venugopal, Swetha; Moune, Séverine; Williams-Jones, Glyn

    2016-10-01

    Cerro Negro, the youngest volcano along the Central American Volcanic Belt (CAVB), is a polygenetic cinder cone with relatively frequent basaltic eruptions. The neighbouring El Hoyo complex, of which Las Pilas is the dominant edifice, is a much larger and older complex with milder and less frequent eruptions. Previous studies have suggested a deep link beneath these two closely spaced volcanoes (McKnight, 1995; MacQueen, 2013). Melt inclusions were collected from various tephra samples in order to determine whether a connection exists and to delineate the features of this link. Major, volatile, and trace elemental compositions reveal a distinct geochemical continuum with Cerro Negro defining the primitive endmember and El Hoyo representing the evolved endmember. Magmatic conditions at the time of melt inclusion entrapment were estimated with major and volatile contents: 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for El Hoyo melts with an overall oxygen fugacity at the NNO buffer. Trace element contents are distinct and suggest Cerro Negro magmas fractionally crystallise while El Hoyo magmas are a mix between primitive Cerro Negro melts and residual and evolved El Hoyo magma. Modelling of end member compositions with alphaMELTS confirms the unique nature of El Hoyo magmas as resulting from incremental mixing between Cerro Negro and residual evolved magma at 4 km depth. Combining all available literature data, this study presents a model of the interconnected subsurface plumbing system. This model considers the modern day analogue of the Lemptégy cinder cones in Massif Central, France and incorporates structurally controlled dykes. The main implications of this study are the classification of Cerro Negro as the newest conduit within the El Hoyo Complex as well as the potential re-activation of the El Hoyo edifice.

  6. Spatial and Temporal Variations of Diffuse Carbon Dioxide Emission From Cerro Negro Volcano, Nicaragua, Central America

    Science.gov (United States)

    Galindo, I.; Melián, G.; Salazar, J.; Hernández, P.; Pérez, N.; Strauch, W.

    2002-12-01

    Cerro Negro is a basaltic cinder cone that has erupted 22 times since its birth in 1850. It is part of a group of four young cinder cones NW of Las Pilas volcano. Cerro Negro's most recent activity was on 5 August 1999 when erupted ash clouds at heights of about 7 km. In December 1999, three months after the eruption, a surface flux survey was carried out at Cerro Negro. Soil CO2 efflux values ranged from 0.5 to 35,000 gm-2d-1 and the total diffuse CO2 output was estimated about 2,800 td-1. Soil temperature reached values above 300°C on the NE flank of the volcano (Salazar et al., 2001). The goal of this study is to evaluate how diffuse CO2 degassing rate at Cerro Negro changes through its eruptive cycle and improve its volcano monitoring program. From Febraury 26 to March 11, 2002, a new diffuse CO2 degassing survey was carried out at Cerro Negro. Sampling distribution was similar to the 1999 survey covering an area of (0.6 Km2). Diffuse CO2 emission rates for the 2002 survey showed a wide range of values from 0.3 to 26,500 gm-2d-1. Most of the study area showed soil CO2 efflux values above 110 gm-2d-1, and the highest CO2 efflux rate was observed in the Northeastern sector of the crater. Soil temperature was also recorded during the survey, and the highest value was observed in the NE flank reaching temperatures up to 450°C. The total diffuse CO2 output for the 2002 survey was estimated about 280 td-1, which is one order of magnitude lower than the estimated for the 1999 survey. This significant temporal variation on diffuse CO2 emission rate seems to be clearly related to the eruptive cycle of Cerro Negro. If we consider that the statistically eruptive cycle for Cerro Negro is less than a decade, it is obvious that the December 1999 survey was performed within its post-eruptive period, while the recent 2002 survey was carried out two years and a half after the most recent eruption of Cerro Negro, within its inter-eruptive period. These results suggest that

  7. The degassing character of a young volcanic center: Cerro Negro, Nicaragua

    Science.gov (United States)

    Lucic, Gregor; Stix, John; Sherwood Lollar, Barbara; Lacrampe-Couloume, Georges; Muñoz, Angélica; Carcache, Martha Ibarra

    2014-09-01

    Cerro Negro volcano is a young basaltic cinder cone which is part of the Nicaraguan volcanic arc. Eruptive activity at Cerro Negro is characterized by explosive strombolian to subplinian eruptions driven by volatile-rich basaltic magma ascending rapidly from various crustal depths (>15 to 6 km) resulting in the onset of precursory activity only ˜30 min before an eruption. In this paper, we present a comprehensive degassing characterization of the volcano over a 4-year period aimed at improving our understanding of the magmatic plumbing network and its relationship with regional tectonics. A total of 124 individual soil gas samples were collected between 2010 and 2013 and analyzed for stable carbon isotopes (δ13C) from CO2. High temperature fumaroles were sampled for δ18O, δD, and 3He/4He isotope analysis, and major degassing zones were mapped using soil CO2 flux measurements. Gases at Cerro Negro are characterized by a strong 3He/4He mantle signature (6.3 to 7.3 RA), magmatic δ13C ratios (-2.3 to -3.0 ‰), meteoric δ18O and δD ratios, and stable CO2 fluxes (31 t d-1). The lack of δ13C fractionation and an increase in the relative mantle component from 2002 to 2012 suggest that the volatile flux at Cerro Negro originates from the mantle and ascends to the surface via a series of crustal fractures that act as permeable conduits. Despite the lack of new eruptions, the hydrothermal system of Cerro Negro continues to evolve due to seasonal inputs of meteoric water, slope failures that expose and bury sites of active degassing, and bursts of regional seismicity that have the potential to open up new conduits for gas release as well as magma. Continuing geophysical and geochemical monitoring of the main edifice and the recently formed south zone is essential, as the volcano remains overdue to erupt.

  8. Dynamics of diffuse CO2 emission and eruptive cycle at Cerro Negro volcano, Nicaragua

    Science.gov (United States)

    Rodriguez, F.; Melian, G.; Barrancos, J.; Padilla, G.; Diaz, M.; Calvo, D.; Nolasco, D.; Perez, N.; Hernandez Perez, P. A.; Ibarra, M.; Strauch, W.; Muñoz, A.

    2009-12-01

    Cerro Negro volcano is the youngest of a group of cinder cones NW of Las Pilas at 25 km from León (Nicaragua) with 685 meters above sea level and one of the most active volcanoes of Nicaragua. It has erupted 21 times since its birth in 1850, with an eruptive cycle about 7-8 years. Since the last eruption, occurred on 5 August 1999, with erupted lava flows and ash clouds together with gas emissions, a research collaboration program between INETER and ITER was established for monitoring diffuse CO2 emissions from Cerro Negro. Since then, ten CO2 surface efflux surveys have been undertaken covering an area of 0,6 km2, in order to evaluate the spatial and temporal variations of CO2 degassing rate in relation with the eruptive cycle of Cerro Negro. Soil CO2 efflux measurements were performed always by means of a portable NDIR sensor according to the accumulation chamber method. A total diffuse CO2 emission output of 1869 t d-1 was estimated for the 1999 survey; just 3 months after the 1999 eruption which can be considered within the post-eruptive phase. For the 2002 and 2003 surveys, considered within the inter-eruptive phase, a clear decreasing tendency on the total diffuse CO2 output was observed, with estimates of 431 and 84 t d-1, respectively. However, during the 2004 a slightly increase on the total diffuse CO2 emission was observed, reaching up to 256 t d-1. The observed relatively increase was addressed to the occurrence of a seismic swarm at Cerro Negro during the survey. The yearly surveys performed at Cerro Negro from 2005 until present, have always shown background levels of CO2 emission, with 68, 38, 45, 10 and 12 t d-1, respectively. The temporal evolution of the diffuse CO2 emissions from Cerro Negro will allow us to determine the typical range of seasonal or other transient departures from its normal or “baseline” behaviour and its relation with the eruptive cycle.

  9. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Carbognani, L.; Hazos, M.; Sanchez, V. (INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela)); Green, J.A.; Green, J.B.; Grigsby, R.D.; Pearson, C.D.; Reynolds, J.W.; Shay, J.Y.; Sturm, G.P. Jr.; Thomson, J.S.; Vogh, J.W.; Vrana, R.P.; Yu, S.K.T.; Diehl, B.H.; Grizzle, P.L.; Hirsch, D.E; Hornung, K.W.; Tang, S.Y.

    1989-12-01

    On March 6, 1980, the US Department of Energy (DOE) and the Ministry of Energy and Mines of Venezuela (MEMV) entered into a joint agreement which included analysis of heavy crude oils from the Venezuelan Orinoco oil belt.The purpose of this report is to present compositional data and describe new analytical methods obtained from work on the Cerro Negro Orinoco belt crude oil since 1980. Most of the chapters focus on the methods rather than the resulting data on Cerro Negro oil, and results from other oils obtained during the verification of the method are included. In addition, published work on analysis of heavy oils, tar sand bitumens, and like materials is reviewed, and the overall state of the art in analytical methodology for heavy fossil liquids is assessed. The various phases of the work included: distillation and determination of routine'' physical/chemical properties (Chapter 1); preliminary separation of >200{degree}C distillates and the residue into acid, base, neutral, saturated hydrocarbon and neutral-aromatic concentrates (Chapter 2); further separation of acid, base, and neutral concentrates into subtypes (Chapters 3-5); and determination of the distribution of metal-containing compounds in all fractions (Chapter 6).

  10. Intense Seismic Activity at Chiles and Cerro Negro Volcanoes on the Colombia-Ecuador Border

    Science.gov (United States)

    Torres, R. A.; Cadena, O.; Gomez, D.; Ruiz, M. C.; Prejean, S. G.; Lyons, J. J.; White, R. A.

    2015-12-01

    The region of Chiles and Cerro Negro volcanoes, located on the Colombian-Ecuadorian border, has experienced an ongoing seismic swarm beginning in Aug. 2013. Based on concern for local residents and authorities, a cooperative broadband monitoring network was installed by the Servicio Geológico Colombiano in Colombia and the Instituto Geofísico of the Escuela Politécnica Nacional in Ecuador. Since November 2013 more than 538,000 earthquakes were recorded; although since May 2015 the seismicity has decreased significantly to an average of 70 events per day. Three large earthquake swarms with increasing energy occurred in Aug.-Oct. 2013, March-May 2014, and Sept.-Dec. 2014. By the end of 2014, roughly 400 earthquakes greater than M 3 had occurred with a maximum rate of 8000 earthquakes per day. The largest earthquake was a 5.6 ML on Oct. 20, 2014. This event produced an InSAR coseismic deformation of ~23 cm (S. Ebmeier, personal communication). Most events are typical brittle failure volcano-tectonic (VT) earthquakes that are located in a cluster beneath the southern flank of Chiles volcano, with depths between 1.5 and 10 km. Although the great majority of earthquakes are VT, some low-frequency (LF, ~0.5 Hz) and very-low-frequency (VLF) events have occurred. Particle motion analysis suggests that the VLF source migrated with time. While a VLF on Oct. 15, 2014 was located south of Chiles volcano, near the InSAR source, the VLF registered on Feb. 14, 2015 was likely located very close to Chiles Volcano. We infer that magma intrusion and resulting fluid exsolution at depths greater than 5 km are driving seismicity in the Chiles-Cerro Negro region. However earthquakes are failing in a manner consistent with regional tectonics. Relative relocations reveal a structure consistent with mapped regional faults. Thus seismicity is likely controlled by an interaction of magmatic and tectonic processes. Because the regional stress field is highly compressional and the volcanoes

  11. Subsurface Connections and Magma Mixing as revealed by Olivine- and Pyroxene-Hosted Melt Inclusions from Cerro Negro Volcano and the Las Pilas-El Hoyo Complex, Nicaragua.

    Science.gov (United States)

    Venugopal, S.; Moune, S.; Williams-Jones, G.

    2015-12-01

    Cerro Negro, the youngest volcano in the Central American Volcanic Belt, is a polygenetic cinder cone with relatively frequent explosive basaltic eruptions. Las Pilas, on the other hand, is a much larger and older complex with milder and less frequent eruptions. Based on historical data, these two closely spaced volcanoes have shown concurrent eruptive behavior, suggesting a subsurface connection. To further investigate this link, melt inclusions, which are blebs of melt trapped in growing crystals, were the obvious choice for optimal comparison of sources and determination of pre-eruptive volatile contents and magmatic conditions. Olivine-hosted inclusions were chosen for both volcanoes and pyroxene-hosted inclusions were also sampled from Las Pilas to represent the evolved melt. Major, volatile and trace elements reveal a distinct geochemical continuum with Cerro Negro defining the primitive end member and Las Pilas representing the evolved end member. Volatile contents are high for Cerro Negro (up to 1260 ppm CO2, 4.27 wt% H2O and 1700 ppm S) suggesting that volatile exsolution is likely the trigger for Cerro Negro's explosive eruptions. Las Pilas volatile contents are lower but consistent with degassing and evolutionary trends shown by major oxides. Trace element contents are rather unique and suggest Cerro Negro magmas fractionally crystallize while Las Pilas magmas are the products of mixing. Magmatic conditions were estimated with major and volatile contents: at least 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for Las Pilas melts with an overall oxygen fugacity at the NNO buffer. In combination with available literature data, this study suggests an interconnected subsurface plumbing system and thus Cerro Negro should be considered as the newest vent within the Las Pilas-El Hoyo Complex.

  12. Unrest of Chiles - Cerro Negro volcanic complex: A binational Ecuador - Colombia effort

    Science.gov (United States)

    Ruiz, M. C.; Gomez, D.; Torres, R.; Cadena, O.; Mothes, P. A.; Anzieta, J. C.; Pacheco, D. A.; Bernard, B.; Acero, W.; Hidalgo, S.; Enriquez, W.; Cordova, A.

    2014-12-01

    The increasing seismic activity at the area of Chiles - Cerro Negro volcanic complex, located at the Ecuador-Colombian border, has been jointly monitored by the Instituto Geofisico - Ecuador and the Observatorio Vulcanologico y Sismologico de Pasto OVSP, a division of the Servicio Geologico Colombiano. Since April 2013, three seismic swarms have been detected in this area and more than 100.000 events are recorded since November 2013. The largest and more recent swarm has a daily average of 676 events between March and June 2014. Currently a seismic network of 8 seismic stations (5 in the Colombian and 3 in Ecuadorean side) are deployed in this area. Epicenters of more than 315 seismic events with magnitudes Ml>2.0 and 10 or more phases are located in an area 1-4 km south of Chiles volcano with shallow depths (up to 14 km). Most of events have magnitudes between 1.0 to 4.0. Nine events have magnitudes larger than 4.0 and the largest event occurred on April 30. 2014 with a local magnitude of 4.7 and inverse-transcurrent component focal mechanism. Waveforms and spectral patterns define these events as volcano-tectonic. Events with large magnitudes (above 3.0) show a very long-period component. Hot spring and deformation measurements also show signals of volcanic unrest.

  13. Public health surveillance after a volcanic eruption: lessons from Cerro Negro, Nicaragua, 1992.

    Science.gov (United States)

    Malilay, J; Real, M G; Ramirez Vanegas, A; Noji, E; Sinks, T

    1996-09-01

    The eruption of the Cerro Negro volcano near León, Nicaragua, on 9 April 1992 distributed an estimated 1.7 million tons of ash over a 200 square kilometer area. An assessment was conducted to evaluate the health effects on approximately 300,000 residents, using routine data obtained by the national epidemiologic surveillance system. It was found that rates of visits to health care facilities for acute diarrheal and respiratory illnesses increased in two study communities, one within and one near the disaster zone. Specifically, visits for acute diarrhea were nearly 6 times more numerous than before the eruption in both communities, while visits for acute respiratory diseases were 3.6 times more frequent in Malpaisillo (the community near the disaster zone) and 6.0 times more frequent in Telica (the community within it). Most of the visits were for infants and children less than 5 years old. Increased diarrheal disease morbidity, which commonly occurs after volcanic eruptions, demands detailed investigation of the type and quality of water supplies following heavy ashfall. Ash-related respiratory problems should be further examined to determine the spectrum of such diseases and the timing of illness onsets among infants and other special population subgroups. Data collected on health conditions before and after an eruption by passive surveillance can be used to detect eruption-related morbidity. Systems already in place, such as Nicaragua's national epidemiologic surveillance system, can be modified or extended so as to increase their sensitivity to new cases and hence their ability to provide appropriate notification to medical relief agencies. PMID:8897722

  14. Temporal Evolution of a Seismic Swarm at Chiles - Cerro Negro volcanic complex

    Science.gov (United States)

    Ruiz, Mario

    2015-04-01

    The increasing seismic activity in the area of the Chiles - Cerro Negro volcanic complex, located on the Ecuador-Colombian border, has been jointly monitored by the Instituto Geofisico - Ecuador and the Observatorio Vulcanologico y Sismologico de Pasto (OVSP), a division of the Servicio Geologico Colombiano. Since April 2013, three seismic swarms have been detected in this area, and more than 400.000 events have been recorded since November 2013. The largest and most recent swarm has a daily average of 3894 events between March and the 12th of December 2014. Currently a seismic network of 13 short- and broad-band stations (5 Colombian, 8 Ecuadorian) was deployed in this area. High quality epicenters of seismic events with magnitudes Ml>2.0, RMSChiles volcano with shallow depths (up to 14 km). Most events have magnitudes between 1.0 to 4.0. Fifteen events have magnitudes larger than 4.0 including an event that occurred on October 20, 2014. This event had a local magnitude of 5.7 and an oblique (strike-slip with some thrusting) focal mechanism. Waveforms and spectral patterns define these events as volcano-tectonic. However, events with moderate to large magnitudes (above 3.0) contain pronounced very-long-period components. Position time series recorded by a dual-frequency GPS receiver at the SE flank of Chiles show a slight departure from the normal tectonic trend beginning with the appearance of the last seismic swarm on or around September 30, 2014. This trend is subsequently punctuated by a sharp deformation transient related to the coseismic displacement of the October 20 event. After more than a year of very anomalous seismic activity and concurrent minor deformation, no evidence of surficial volcanic activity has been documented.

  15. Shallow earthquake inhibits unrest near Chiles-Cerro Negro volcanoes, Ecuador-Colombian border

    Science.gov (United States)

    Ebmeier, Susanna K.; Elliott, John R.; Nocquet, Jean-Mathieu; Biggs, Juliet; Mothes, Patricia; Jarrín, Paúl; Yépez, Marco; Aguaiza, Santiago; Lundgren, Paul; Samsonov, Sergey V.

    2016-09-01

    Magma movement or reservoir pressurisation can drive swarms of low-magnitude volcano-tectonic earthquakes, as well as occasional larger earthquakes (>M5) on local tectonic faults. Earthquakes >M5 near volcanoes are challenging to interpret in terms of evolving volcanic hazard, but are often associated with eruptions, and in some cases enhance the ascent of magma. We present geodetic observations from the first episode of unrest known to have occurred near Chiles and Cerro Negro de Mayasquer volcanoes on the Ecuador-Colombian border. A swarm of volcano-tectonic seismicity in October 2014 culminated in a Mw 5.6 earthquake south of the volcanoes. Satellite radar data spanning this earthquake detect displacements that are consistent with dextral oblique slip on a reverse fault at depths of 1.4-3.4 km within a SSW-NNE trending fault zone that last ruptured in 1886. GPS station measurements capture ∼20 days of uplift before the earthquake, probably originating from a pressure source ∼10-15 km south of Volcán Chiles, at depths exceeding 13 km. After the Mw 5.6 earthquake, uplift ceased and the rate of seismicity began to decrease. Potential mechanisms for this decline in activity include a decrease in the rate of movement of magma into the shallow crust, possibly caused by the restriction of fluid pathways. Our observations demonstrate that an earthquake triggered during volcanic unrest can inhibit magmatic processes, and have implications for the hazard interpretation of the interactions between earthquakes and volcanoes.

  16. Stress controlled magma-earthquake interaction during unrest at Chiles-Cerro Negro Volcanoes (Ecuador-Colombian border)

    Science.gov (United States)

    Ebmeier, S. K.; Elliott, J. R.; Nocquet, J. M.; Biggs, J.; Mothes, P. A.; Lundgren, P.; Samsonov, S. V.; Jarrin, P.; Yepez, M.; Aguaiza, S.

    2015-12-01

    The movement of fluids beneath a volcano can cause deformation, and therefore changes to the subsurface stress field that manifest in swarms of low magnitude (Chiles-Cerro Negro volcanoes on the Ecuador-Colombian border. These volcanoes were previously considered to be historically inactive, but between 2013 and early 2015 there were three episodes of unrest characterised by VT swarms of increasing energy and duration. GPS measurements at two stations near Volcán Chiles show inflation over a time period of approximately twenty days prior to the 20th October, consistent with the intrusion of magma at half space depths >13 km. This inflation took place during a swarm of VT seismicity with thousands of low magnitude events per day and culminated in a M 5.6 earthquake on the 20th October, when inflation abruptly ceased. We measure coseismic displacements from the M 5.6 earthquake with data from three independent InSAR platforms and find that they are consistent with shallow slip of 1.2 m on an oblique reverse fault. This fault plane would have experienced positive Coulomb stress changes from some of the range of potential sources consistent with the inflation. Magmatic intrusion could therefore have contributed to the loading on the fault directly through stress changes caused by pressurisation, and indirectly through the decrease in effective friction coefficient due to elevated pore fluid pressure. The cessation of inflation immediately after the moderate earthquake suggests a link between the two events. We expect slip on the fault plane identified from the InSAR data to have resulted in compression in the shallow crust south of Volcán Chiles, above the source that had previously been inflating. This would have inhibited further ascent of magma. The Chiles-Cerro Nego unrest provides rare observations of interaction between magmatic intrusion and a moderate earthquake during volcanic unrest.

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

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    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.

  18. Perfil infectológico de poblaciones mapuche de Cerro Policía y Aguada Guzmán de la provincia de Río Negro

    OpenAIRE

    Rey, Jorge Alberto; Dejean, Cristina Beatriz; Niborski, Ricardo; Arrayago, Alicia M.; Kohan, Abraham I.; Carnese, Francisco R.

    1996-01-01

    Nuestro trabajo analiza la prevalencia de marcadores de algunas infecciones que afectan las poblaciones mapuche de Cerro Policía (CP) y Aguada Guzmán (AG) en la Prov. de Río Negro. Los estudios incluídos son: determinación de anticuerpos anti-Treponema pallidum, anti-Trypanosoma cruzii, anti-Echinococcus granulosus, antígeno de superficie de la Hepatitis B (HBsAg), anticuerpos contra el core de la Hepatitis B (anti-HBc), anticuerpos contra el virus de la Hepatitis A (anti-HAV). Se estudiaron ...

  19. 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.

  20. Approaching viscosity control: electrical heating of extra heavy oil as alternative to diluent injection in down hole in Cerro Negro Field, Faja Petrolifera del Orinoco

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Manuel [Petroleos de Venezuela SA, PDVSA (Venezuela)

    2011-07-01

    Electrical heating is a method used to enhance oil recovery in extra heavy oil reservoirs. This method can be used when diluent injection or other methods are not able to reduce oil viscosity sufficiently or when problems of product quality or quantity arise. The aim of this paper is to evaluate the performance of electrical heating, individually and simultaneously with injection of diluents. For this purpose, simulations were undertaken in one well with integrated electrical heating and diluent injection in Cerro Negro Field in the Orinoco oil belt, Venezuela. Results have shown that the application of both methods together is more profitable than the application of electrical heating alone. This paper demonstrated that the use of electrical heating and diluent injection combined is a valid alternative to diluent injection alone, reducing production loss.

  1. 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

  2. Perfil infectológico de poblaciones mapuche de Cerro Policía y Aguada Guzmán de la provincia de Río Negro

    Directory of Open Access Journals (Sweden)

    Rey, Jorge Alberto

    1996-01-01

    Full Text Available Nuestro trabajo analiza la prevalencia de marcadores de algunas infecciones que afectan las poblaciones mapuche de Cerro Policía (CP y Aguada Guzmán (AG en la Prov. de Río Negro. Los estudios incluídos son: determinación de anticuerpos anti-Treponema pallidum, anti-Trypanosoma cruzii, anti-Echinococcus granulosus, antígeno de superficie de la Hepatitis B (HBsAg, anticuerpos contra el core de la Hepatitis B (anti-HBc, anticuerpos contra el virus de la Hepatitis A (anti-HAV. Se estudiaron 160 muestras en CP y 83 en AG. Los resultados muestran alta prevalencia para anti-HAV en CP (89.2% y en AG (77.1% y para hidatidosis (10.6% y 9.6% respectivamente. Se hallaron valores nulos o bajos para sífilis (CP: 0.0 % y AG:2.4%. La prevalencia para Chagas fue del 10% en CP y 0.0% en AG. Los datos para Hepatitis B fueron nulos o bajos: HBsAg (CP:0.0% y AG:1.2% y anti-HBc(CP:0.6% y AG:0.0%. Los resultados indican que, aún estando estas dos poblaciones tan próximas muestran diferencias en los perfiles de los marcadores serológicos estudiados. Al comparar las tasas de prevalencia con las de otras poblaciones de América, cada una presenta un perfil diferente que depende de la población y del agente infeccioso considerado.

  3. Models of Metabolic Community Structure in Martian Habitable Environments: Constraints from a Terrestrial Analog Acid-Sulfate Fumarole Environment, Cerro Negro Volcano, Nicaragua

    Science.gov (United States)

    Rogers, K. L.; McCollom, T. M.; Hynek, B. M.

    2014-12-01

    Microbial habitability in extreme environments on Earth is described by microscale geochemical conditions that constrain metabolic niches in concert with long-term habitat stability that is governed by dynamic geologic processes. Using terrestrial analogs to identify habitable martian environments requires correlating microscale geochemical constraints with reconstructions of past martian environments that are based on global-scale observations. While past martian environments can be characterized by primary parameters (e.g. pH, redox, mineralogy, thermal history), microbial habitability on Earth is a complex function of both primary and derived parameters (e.g. metabolic reaction energetics, chemical & thermal gradients, flow dynamics). In recent years we have been investigating acid-sulfate fumaroles at the Mars analog site, Cerro Negro Volcano, Nicaragua, where habitability is constrained by steep thermal gradients, spatially- and temporally-variable vent dynamics, and limited water and nutrient availability. The most common niche identified thus far is found in fumaroles that host mixed photosynthetic and chemosynthetic endolithic microbial communities. One such endolith is dominated by acidic red algae (Cyanidiales), aerobic bacterial heterotrophs (Ktedonobacteria), and archaeal thermoacidophiles (Hyperthermus, Caldisphaera, and Thermofilum). An analysis of the metabolic structure suggests that primary production by the red algae supports the growth of heterotrophic thermoacidophiles. Diversification among the chemoheterotrophs with respect to temperature and oxygen tolerance suggests community adaptation to environmental gradients or variable venting dynamics. Furthermore, individual cells within the endolith are silica-encrusted, providing the possibility for biosignature formation and preservation. Putative hydrothermal environments on early Mars with similar conditions could have supported endolithic communities with comparable metabolic strategies. Even

  4. 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.

  5. Geología de la Formación Cerro Negro (Cretácico en Isla Livingston: aportes a su geocronología y contenido paleontológico

    Directory of Open Access Journals (Sweden)

    C.A. Parica

    2007-12-01

    Full Text Available La península Byers se encuentra en el extremo occidental de la isla Livingston, archipiélago de las islas Shetland del Sur. Geológicamente está caracterizada por depósitos marinos, continentales y volcanismo cretácico-terciario que son incluidos en la Formación Cerro Negro de la sección superior del Grupo Byers. Las secuencias magmáticas han sido divididas en dos grupos principales, el primero comprende a las rocas piroclásticas y reúne cinco unidades con un importante desarrollo y distribución en el área. Por su parte, el segundo grupo comprende lavas e intrusivos aflorantes en cerros Don Carlos, Usnea (Usnea Plug, Chester (Chester Cone, Sealer (Sealer Hill y Negro (Negro Hill. Los términos sedimentarios incluyen conglomerados, areniscas y pelitas, de color gris verdoso con estratificación entrecruzada (tanto tabular como en artesa, raramente estratos macizos, laminación horizontal (en algunos casos de naturaleza rítmica, y estructuras de deformación sinsedimentaria (principalmente laminación convoluta. Se propone un ambiente fluvial de depositación, con canales dominados por carga de lecho y barras areno-gravosas bien desarrolladas. En lo que corresponde al sector de planicie de inundación, predominó allí la depositación de material limo-arcilloso por corrientes tractivas débiles durante las crecientes. En las áreas deprimidas de las planicies habría tenido lugar la formación de cuerpos de aguas de poca profundidad en los que se vió favorecida la preservación de la macro y microflora. En las nuevas localidades fosilíferas de península Byers, Domo Rotch (Rotch Dome, cerro Don Carlos, Lomada de las Plantas y 904, ha sido reconocida la presencia de las especies: Araucarites sp., Archangelskya furcata Herbst, Cladophlebis sp., Dictyozamites sp., Elatocladus sp, Phyllopteroides sp., Pseudoctenis sp., Ptyllophyllum menendezii Cantrill, Sphenopteris sp., Eocyathea remesaliae Césari, Sergioa austrina Césari y

  6. 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

  7. null Cerro Negro, Nicaragua Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This cinder cone in western Nicaragua has a name that means "black hill." It has erupted more than 20 times since its birth in 1850. Explosive eruptions from the...

  8. The Marianas-San Marcos vein system: characteristics of a shallow low sulfidation epithermal Au-Ag deposit in the Cerro Negro district, Deseado Massif, Patagonia, Argentina

    Science.gov (United States)

    Vidal, Conrado Permuy; Guido, Diego M.; Jovic, Sebastián M.; Bodnar, Robert J.; Moncada, Daniel; Melgarejo, Joan Carles; Hames, Willis

    2016-08-01

    The Cerro Negro district, within the Argentinian Deseado Massif province, has become one of the most significant recent epithermal discoveries, with estimated reserves plus resources of ˜6.7 Moz Au equivalent. The Marianas-San Marcos vein system contains about 70 % of the Au-Ag resources in the district. Mineralization consists of Upper Jurassic (155 Ma) epithermal Au- and Ag-rich veins of low to intermediate sulfidation style, hosted in and genetically related to Jurassic intermediate composition volcanic rocks (159-156 Ma). Veins have a complex infill history, represented by ten stages with clear crosscutting relationships that can be summarized in four main episodes: a low volume, metal-rich initial episode (E1), an extended banded quartz episode with minor mineralization (E2), a barren waning stage episode (E3), and a silver-rich late tectonic-hydrothermal episode (E4). The first three episodes are interpreted to have formed at the same time and probably from fluids of similar composition: a 290-230 °C fluid dominated by meteoric and volcanic waters (-3‰ to -0‰ δ18Owater), with <3 % NaCl equivalent salinity and with a magmatic source of sulfur (-1 to -2 ‰ δ34Swater). Metal was mainly precipitated at the beginning of vein formation (episode 1) due to a combination of boiling at ˜600 to 800 m below the paleowater table, and associated mixing/cooling processes, as evidenced by sulfide-rich bands showing crustiform-colloform quartz, adularia, and chlorite-smectite banding. During episodes 2 and 3, metal contents progressively decrease during continuing boiling conditions, and veins were filled by quartz and calcite during waning stages of the hydrothermal system, and the influx of bicarbonate waters (-6 to -8.5 ‰ δ18Owater). Hydrothermal alteration is characterized by proximal illite, adularia, and silica zone with chlorite and minor epidote, intermediate interlayered illite-smectite and a distal chlorite halo. This assemblage is in agreement with

  9. The Marianas-San Marcos vein system: characteristics of a shallow low sulfidation epithermal Au-Ag deposit in the Cerro Negro district, Deseado Massif, Patagonia, Argentina

    Science.gov (United States)

    Vidal, Conrado Permuy; Guido, Diego M.; Jovic, Sebastián M.; Bodnar, Robert J.; Moncada, Daniel; Melgarejo, Joan Carles; Hames, Willis

    2016-01-01

    The Cerro Negro district, within the Argentinian Deseado Massif province, has become one of the most significant recent epithermal discoveries, with estimated reserves plus resources of ˜6.7 Moz Au equivalent. The Marianas-San Marcos vein system contains about 70 % of the Au-Ag resources in the district. Mineralization consists of Upper Jurassic (155 Ma) epithermal Au- and Ag-rich veins of low to intermediate sulfidation style, hosted in and genetically related to Jurassic intermediate composition volcanic rocks (159-156 Ma). Veins have a complex infill history, represented by ten stages with clear crosscutting relationships that can be summarized in four main episodes: a low volume, metal-rich initial episode (E1), an extended banded quartz episode with minor mineralization (E2), a barren waning stage episode (E3), and a silver-rich late tectonic-hydrothermal episode (E4). The first three episodes are interpreted to have formed at the same time and probably from fluids of similar composition: a 290-230 °C fluid dominated by meteoric and volcanic waters (-3‰ to -0‰ δ18Owater), with <3 % NaCl equivalent salinity and with a magmatic source of sulfur (-1 to -2 ‰ δ34Swater). Metal was mainly precipitated at the beginning of vein formation (episode 1) due to a combination of boiling at ˜600 to 800 m below the paleowater table, and associated mixing/cooling processes, as evidenced by sulfide-rich bands showing crustiform-colloform quartz, adularia, and chlorite-smectite banding. During episodes 2 and 3, metal contents progressively decrease during continuing boiling conditions, and veins were filled by quartz and calcite during waning stages of the hydrothermal system, and the influx of bicarbonate waters (-6 to -8.5 ‰ δ18Owater). Hydrothermal alteration is characterized by proximal illite, adularia, and silica zone with chlorite and minor epidote, intermediate interlayered illite-smectite and a distal chlorite halo. This assemblage is in agreement with

  10. Paleomagnetism of the Late Proterozoic Sierras Bayas Group and the Ediacaran-Cambrian Apparent Polar Wander Path of the Rio de la Plata Craton

    Science.gov (United States)

    Rapalini, A. E.; Trindade, R. I.; Poiré, D. G.; Vieira, L.

    2007-05-01

    The apparent polar wander path (APWP) of the Rio de la Plata craton (RP) for the Late Proterozoic and Early Paleozoic is of significance to reconstruct the tectonic processes that led to the amalgamation of Gondwana. In order to define the Ediacaran-Cambrian APWP for RP, a systematic paleomagnetic study was carried out in the Sierras Bayas Group exposed in the province of Buenos Aires, Argentina. 328 samples from 44 sites were collected in the Cryogenian to Ediacaran Villa Mónica Fm., the Ediacaran Cerro Largo, Loma Negra and Las Aguilas Fms. and the Cambrian (?) Cerro Negro Fm. Sampling included mainly limestone and dolomite, red claystone and marls. Although most sites presented secondary magnetizations of likely recent and Permian (?) age, a few sites from the Cerro Largo and uppermost Villa Mónica Fms. carry a pre-tectonic magnetization that yielded a preliminary paleomagnetic pole at 34.6°S, 211.3° (6.4°/10-9°; n: 18 samples), while a pre-tectonic remanence from the Cerro Negro Fm. yielded a paleomagnetic pole at 10.9°N, 323.5°E (9.7°/13.3°, n:17 samples). These two preliminary paleomagnetic poles for the Sierras Bayas Group together with previously published ones permit to define with confidence the APWP of RP from ca. 600 to ca. 500 Ma.

  11. Geología y geocronología Rb-Sr de granitoides de Sierra Grande, provincia de Río Negro

    Directory of Open Access Journals (Sweden)

    Ricardo Varela

    2009-04-01

    Full Text Available Al este de Sierra Grande la unidad más antigua es la Ectinita El Jagüelito, metagrauvacas y pizarras, cortadas por granitoides ordovícicos (Rb-Sr en roca total 467 ± 16 Ma; U-Pb en circón 476 ± 4 Ma. Ectinitas y granitoides son cubiertos discordantemente por sedimentitas clásticas fosilíferas silúricas de la Formación Sierra Grande y el total de unidades deformado por pliegues y fallas. Al sur de Sierra Grande, Mina Hiparsa, afloran la Ectinita El Jagüelito, la Formación Sierra Grande y granitoides, en un contexto de fuerte deformación tectónica. Desde mitad de siglo pasado se discute si los granitoides constituyen el basamento de la Formación Sierra Grande o si son intrusivos en la misma. La Formación Sierra Grande está afectada por metamorfismo térmico. Datos radimétricos previos de granitoides son discordantes (Rb-Sr en roca total 252 ± 5 Ma; 363 ± 57 Ma; 318 ± 28 Ma; U-Pb SHRIMP en circón 476 ± 6 Ma. Se efectuaron nuevos análisis Rb-Sr en roca total y minerales y se propone la existencia de dos unidades graníticas. En granitoides del noroeste de la mina, Granito Mina Hiparsa, se obtuvieron dos isocronas (262 ± 6 Ma, 87Sr/86Sr inicial = 0,7162 ± 0,0003 y 263 ± 9 Ma, 87Sr/86Sr inicial = 0,7149 ± 0,0009. En los granitoides al oeste de la Mina Hiparsa, Granodiorita Laguna Medina, se efectuó una isocrona (260 ± 3 Ma, 87Sr/86Sr Inicial = 0,7078 ± 0,0012. Las rocas estudiadas son el producto de plutonismo ordovícico temprano y pérmico tardío-temprano. Las tres isocronas roca total-minerales son pérmicas, pero dos por metamorfismo y reseteo de rocas ordovícicas (87Sr/86Sr inicial ~ 0,7150 y una por cristalización (87Sr/86Sr inicial ~ 0,7080.

  12. Evolución magmática del Granito Peñón Rosado, Cerro Asperecito, flanco occidental de la sierra de Famatina

    Directory of Open Access Journals (Sweden)

    J.A. Dahlquist

    2006-03-01

    Full Text Available El granate es un mineral accesorio poco común en rocas ígneas y constituye un tema relevante de la petrología ígnea. Estudios combinados de petrología, química mineral, geoquímica de roca total y geoquímica isotópica en el cerro Asperecito indican que los granitoides con granate que forman el Granito Peñón Rosado (GPR fueron producidos por la fusión parcial de rocas metasedimentarias con subsecuente diferenciación durante su emplazamiento en el Ordovícico inferior-medio. En este sentido, la facies GPR1 representa un cristalizado temprano, la facies GPR2 representa un fundido diferenciado, y la facies GPR3 un fundido residual. El Granito Peñón Rosado, fue emplazado en condiciones de moderada temperatura (785ºC y presión media (4,4 kb en profundidades de la corteza media (~15 km. El emplazamiento casi sincrónico en la corteza media de una abundante suite metaluminosa durante el Ordovícico inferior-medio (468 Ma en el cerro Asperecito fue suficiente para inducir anatexis local de los metasedimentos circundantes. Los contenidos de elementos mayoritarios (CaO, Na2O y elementos traza (Rb, Sr, Ba en el Granito Peñón Rosado sugieren anatexis a partir de un material inmaduro acumulado en un plataforma continental. Así, el Granito Peñón Rosado es un típico granitoide tipo-S con granate y el modelo establecido aquí puede contribuir a un mejor entendimiento acerca de la cristalización del granate en rocas graníticas.

  13. Petrografía y geoquímica de las anfibolitas del cerro La Cocha, Sierra Chica, Córdoba Petrography and geochemistry of the anphibolites from La Cocha Hill, Sierra Chica, Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Patricia A Anzil

    2012-06-01

    Full Text Available En la Sierra Chica de Córdoba, a dos kilómetros al sur del Observatorio Astronómico de Bosque Alegre, se encuentran dos variedades litológicas de anfibolitas asociadas al cuerpo ultramáfico de La Cocha. Estas variedades incluyen anfibolitas sin piroxeno, compuestas por hornblenda, plagioclasa, titanita y minerales opacos, emplazadas en el núcleo de la estructura plegada del cuerpo ultramáfico. El segundo grupo son anfibolitas con dos piroxenos, compuestas por hornblenda, plagioclasa, ortopiroxeno (En, clinopiroxeno (Di y como accesorios minerales opacos, apatita, escasa titanita y circón. Estas anfibolitas se encuentran en el encajonante del cuerpo ultramáfico de La Cocha, asociadas a gneises granatíferos sillimaníticos. Con el objetivo de determinar el protolito, que por metamorfismo dieron origen a las anfibolitas, se realizó un estudio geoquímico de roca total. Las anfibolitas con dos piroxenos se clasifican dentro de la serie toleítica y, en base al diagrama de tierras raras se las podría asociar a un ambiente tectónico de generación de tipo N-MORB. Las anfibolitas sin piroxeno, también corresponderían a un ambiente asimilable a N-MORB, con mayor depresión en las tierras raras livianas, sugiriendo probablemente un ambiente de generación del fundido en un manto empobrecido.In the Sierra Chica of Córdoba (Argentina, two lithological varieties of amphibolites associated with the La Cocha ultramafic body, crops out two kilometer south of the Bosque Alegre Astronomical Observatory. These varieties include non-pyroxene amphibolite composed of hornblende, plagioclase, titanite and opaque minerals, situated in the core of the ultramafic body folded structure. The second group is pyroxene amphibolites comprising hornblende, plagioclase, orthopyroxene (En, clino-pyroxene (Di and accessories including opaque minerals, apatite, more rarely titanite and zircon. This group appears in the ultramafic country rock represented by garnet

  14. 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.

  15. Indios y blancos en la ciudad minera: Cerro de Pasco en el siglo XIX1

    OpenAIRE

    Contreras, Carlos

    2014-01-01

    En este artículo se presenta una descripción de las condiciones de vida, materiales y culturales en Cerro de Pasco durante el siglo pasado, cuando era una de las principales ciudades de la sierra peruana, tanto en lo económico como en lo demográfico.El autor discute las características de la estructura social de Cerro de Pasco, recalcando la yuxtaposición de elementos económicos y étnico-culturales y el tipo de relaciones sociales prevalecientes. Luego describe las características y condicion...

  16. El bronce final y la Edad del Hierro en "Cerro del Berrueco" (Ávila-Salamanca

    Directory of Open Access Journals (Sweden)

    J. Francisco FABIÁN GARCÍA

    2009-10-01

    Full Text Available El Cerro del Berrueco es un monte-isla enclavado en las inmediaciones del Sistema Central y, más concretamente, de las Sierras de Gredos y Béjar, en el sector Sur-Occidental de la Meseta Norte. Corresponde una parte de él a la provincia de Avila y otra, más extensa, a la de Salamanca.

  17. La secuencia ocupacional y cerámica del cerro barajas, Guanajuato y sus relaciones con el centro, el occidente y el norte de México

    OpenAIRE

    Migeon, Gérald; Pereira, Grégory

    2013-01-01

    Note portant sur l’auteur Note portant sur l’auteur Los sitios del Cerro Barajas, municipio de Pénjamo, se encuentran en el límite suroeste del estado de Guanajuato. Forman un conjunto de asentamientos prehispánicos que se extiende por la falda norte del cerro (figura 1). Dicho cerro domina el río Lerma del lado sur, el río Turbio del lado este y los valles y la Sierra de Pénjamo del lado norte; asentamientos fueron registrados por primera vez al inicio de la década los años 1980 en el marco ...

  18. Estratigrafía y petrología del sector noreste de sierra de Apas. Provincia del Chubut Stratigraphy and petrology of the Northeastern sector of Sierra de Apas. Chubut Province

    Directory of Open Access Journals (Sweden)

    M. Remesal

    2004-12-01

    Full Text Available La sierra de Apas, ubicada entre las provincias de Rio Negro y Chubut, forma parte del magmatismo de intraplaca emplazado durante el Paleogeno-Neógeno en el norte de la Patagonia extrandina. En el sector noreste se ha definido una estratigrafía integrada por: traquitas oscuras, flujos piroclásticos, traquitas claras, domos riolíticos y basaltos porfíricos y afíricos. Las traquitas oscuras, son relativamente más antiguas, tienen bajo porcentaje de fenocristales, y clasifican como traquitas- benmoreítas. Las traquitas claras son porfíricas, y clasifican como comenditas. Su ubicación estratigráfica es confirmada por una edad K/Ar de 19 ± 2 Ma. Los flujos piroclásticos son predominantemente vítreos, cubren a las traquitas oscuras y tienen composiciones traquiandesíticas. La petrografía y geoquímica establecen una estrecha relación con las traquitas claras. El único cuerpo dómico en el área es el cerro Colorado, cuya composición corresponde a una riolita peralcalina ó comendita; una edad K/Ar de 24 ± 1 Ma establece por primera vez su relación temporal. La unidad efusiva más joven corresponde a lavas basálticas, agrupadas en afíricas y porfíricas. Se propone designar a las primeras como basaltos olivínicos transicionales en tanto que los basaltos porfíricos se subdividen en basaltos olivínicos alcalinos y hawaiitas. Los datos estratigráficos y geoquímicos sugieren que la asociación volcánica estudiada es el resultado de al menos dos etapas evolutivas. Una de ellas incluye los basaltos, traquitas claras, flujos claros y comenditas que muestran un patrón de cristalización fraccionada. Las traquitas oscuras, más viejas, corresponderían a otro estadio evolutivo.The volcanic building of Sierra de Apas (located on the limit between the Rio Negro and Chubut provinces is part of the Paleogene-Neogene intraplate magmatism of the northern Extrandean Patagonia. This contribution is focused on the northeastern of the Sierra

  19. Professor Camillo Negro's Neuropathological Films.

    Science.gov (United States)

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease.

  20. Professor Camillo Negro's Neuropathological Films.

    Science.gov (United States)

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease. PMID:26684422

  1. Primer registro de oso negro americano (Ursus americanus) para el estado de Hidalgo, México

    OpenAIRE

    Alberto Enrique Rojas-Martínez; Luis Antonio Juárez-Casillas

    2013-01-01

    Se documenta el primer registro del oso negro americano (Ursus americanus) para el estado de Hidalgo, México, mismo que representa el punto más sureño de la distribución de esta especie. El ejemplar se encontró muerto cerca del poblado El Aguaje de Cerro Prieto en un lugar conocido como La Joya, municipio de La Misión, en el norte del estado, a una altitud de 1 481 m, probablemente correspondía a un individuo errante proveniente del estado de Querétaro.

  2. Microestructuras de deformación en rocas granulíticas, Cerro La Crespa, Tandilia, Provincia de Buenos Aires

    OpenAIRE

    Lucrecia Jorgensen; María C. Frisicale; Luis V Dimieri

    2008-01-01

    El cerro La Crespa, localizado un kilómetro al sur de la megacizalla de Azul, integra las sierras de Azul, las cuales componen parte del Sistema de Tandilia. El presente trabajo trata sobre el estudio petrográfico-microestructural, donde se determina la composición modal y arreglos texturales a escala de grano y una primera caracterización geoquímica de rocas granulíticas aflorantes en el sector NO del cerro La Crespa. A partir de tales análisis, se intenta dilucidar los mecanismos de deforma...

  3. THE CITY AND THE NEGRO.

    Science.gov (United States)

    SILBERMAN, CHARLES E.

    A SOLUTION TO THE NEGRO PROBLEM DEMANDS DIFFICULT AND HEROIC DECISIONS ON THE PART OF CIVIC AND POLITICAL LEADERS AND CHANGES IN THE BEHAVIOR OF AMERICANS FROM EVERY WALK OF LIFE--TEACHERS AND STUDENTS, TRADE-UNION LEADERS AND MEMBERS, AND EMPLOYERS AND EMPLOYEES. CURRENT ACTION BEING TAKEN AND FUTURE ACTIONS WHICH NEED TO BE TAKEN ARE DISCUSSED.…

  4. Geothermal drilling in Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A., Bernardo

    1982-08-10

    The number of characteristics of the different wells that have been drilled in the Cerro Prieto geothermal field to date enable one to summarize the basic factors in the applied technology, draw some conclusions, improve systems and procedures, and define some problems that have not yet been satisfactorily solved, although the existing solution is the best now available. For all practical purposes, the 100 wells drilled in the three areas or blocks into which the Cerro Prieto field has been divided have been completed. Both exploratory and production wells have been drilled; problems of partial or total lack of control have made it necessary to abandon some of these wells, since they were unsafe to keep in production or even to be used for observation and/or study. The wells and their type, the type of constructed wells and the accumulative meters that have been drilled for such wells are summarized.

  5. Update of the conceptual geological model for the geothermal reservoir in Cerro Prieto, BC; Actualizacion del modelo geologico conceptual del yacimiento geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Lira Herrera, Hector [Comision Federal de Electricidad, Mexicali, B.C., (Mexico)

    2005-06-01

    noroeste de Mexico durante el Terciario Superior, en el area de Cerro Prieto dio como resultado la formacion de una cuenca de tipo medio graben, entre las fallas Cerro Prieto Imperial (Cuenca Cerro Prieto), en la que se interpreta la existencia de fallas listricas con direccion predominante noroeste-sureste y noreste-suroeste, que se escalonan en forma general al NE. La zona de debilidad cortical generada durante el Terciario permitio el emplazamiento de un intrusito de composicion basica dentro de la cuenca tectonica, el cual ha sido asociado con una anomalia magnetica, denominada Nuevo Leon; este intrusivo ha sido alimentado por nuevas instrusiones magmaticas originadas por la actual tectonica extensional del Golfo de California. Las rocas mas antiguas identificadas en la zona estan compuestas por gneiss y esquistos de biotita de edad Permico-Jurasico, y tonalitas del Jurasico-Cretacico que estan en contacto con granitos del Cretacico, que en conjunto representan el basamento de la region. La columna litologica en el subsuelo de la cuenta tectonica de Cerro Prieto esta formada por un basamento compuesto por granitos del Cretacico; un paquete arcilloso representado por lutitas grises con intercalaciones de areniscas, lutitas cafes del Terciario y lodolitas, con un espesor promedio de 2700 m, que descansan sobre el basamento; y, finalmente sedimentos clasticos de edad Cuaternaria producto del material depositado por el Rio Colorado y los abanicos aluviales de la sierra Cucapa, compuestos por gravas, arenas y arcillas que cubren el paquete de lutitas, alcanzando un espesor promedio de 2500 m. Los fluidos que alimentan al yacimiento geotermico son calentados al pasar por la zona donde se localiza el intrusivo basico (fuente de calor) y migran a traves de las fallas listricas hacia estratos permeables (areniscas), que se localizan dentro del paquete de lutitas grises terciarias.

  6. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez R, J.; de la Pena L, A.

    1981-01-01

    The most recent information on the Cerro Prieto geothermal aquifer is summarized, with special emphasis on the initial production zone where the wells completed in the Alpha aquifer are located. These wells produce steam for power plant units 1 and 2. Brief comments also are made on the Beta aquifer, which underlies the Alpha aquifer in the Cerro Prieto I area and which extends to the east to what is known as the Cerro Prieto II and Cerro Prieto III areas. The location of the area studied is shown. The Alpha and Beta aquifers differ in their mineralogy and cementing mineral composition, temperatures, and piezometric levels. The difference in piezometric levels indicates that there is no local communication between the two aquifers. This situation has been verified by a well interference test, using well E-1 as a producer in the Beta aquifer and well M-46 as the observation well in the Alpha aquifer. No interference between them was observed. Information on the geology, geohydrology, and geochemistry of Cerro Prieto is presented.

  7. Body density differences between negro and caucasian professional football players

    OpenAIRE

    Adams, J.; Bagnall, K. M.; McFadden, K. D.; Mottola, M.

    1981-01-01

    Other workers have shown that the bone density for the average negro is greater than for the average caucasian. This would lead to greater values of body density for the average negro but it is confused because the average negro has a different body form (and consequently different proportions of body components) compared with the average caucasian. This study of body density of a group of professional Canadian football players investigates whether or not to separate negroes from caucasians w...

  8. El recorrido al Cerro Gordo y el ritual tepehuano de las ofrendas en los cerros de la comunidad de San Bernardino de Milpillas

    Directory of Open Access Journals (Sweden)

    Chantal CRAMAUSSEL

    2014-01-01

    Full Text Available El ritual de las ofrendas es una ceremonia propiciatoria de la lluvia que se efectúa al terminar la estación seca en los cerros más altos de la comunidad de San Bernardino de Milpillas Chico, en la Sierra Tepehuana del estado de Durango. A esos rituales distintos de los cató- licos que forman parte del ciclo anual de costumbre concurren las autoridades civiles, los curanderos y miembros del Consejo de ancianos. Es un momento muy importante en el que se refuerza la cohesión de los tepehuanos que tienen un patrón de asentamiento muy disperso, como los demás grupos del norte, pero sus rituales presentan también similitudes con los mesoamericanos.

  9. Sedimentary rocks Uranium in Cerro Largo Province

    International Nuclear Information System (INIS)

    With the aim of the uranium minerals exploration has been carried out several studies by UTE technicians in Cerro Largo Province from 1968 to 1969. In uranium concentration has been found pyrite, phosphate, iron oxides and manganese in uranium. Furthermore in La Divisa Ore were studied concentration Uranium enrichment has been studied in La Divisa ore

  10. Optical atmospheric extinction over Cerro Paranal

    NARCIS (Netherlands)

    F. Patat; S. Moehler; K. O'Brien; E. Pompei; T. Bensby; G. Carraro; A. de Ugarte Postigo; A. Fox; I. Gavignaud; G. James; H. Korhonen; C. Ledoux; S. Randall; H.A.A. Sana; J. Smoker; S. Stefl; T. Szeifert

    2011-01-01

    Aims. The present study was conducted to determine the optical extinction curve for Cerro Paranal under typical clear-sky observing conditions, with the purpose of providing the community with a function to be used to correct the observed spectra, with an accuracy of 0.01 mag airmass-1. Additionally

  11. 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.

  12. 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...

  13. Estratigrafía y petrología del sector noreste de sierra de Apas. Provincia del Chubut

    Directory of Open Access Journals (Sweden)

    M. Remesal

    2004-12-01

    Full Text Available La sierra de Apas, ubicada entre las provincias de Rio Negro y Chubut, forma parte del magmatismo de intraplaca emplazado durante el Paleogeno-Neógeno en el norte de la Patagonia extrandina. En el sector noreste se ha definido una estratigrafía integrada por: traquitas oscuras, flujos piroclásticos, traquitas claras, domos riolíticos y basaltos porfíricos y afíricos. Las traquitas oscuras, son relativamente más antiguas, tienen bajo porcentaje de fenocristales, y clasifican como traquitas- benmoreítas. Las traquitas claras son porfíricas, y clasifican como comenditas. Su ubicación estratigráfica es confirmada por una edad K/Ar de 19 ± 2 Ma. Los flujos piroclásticos son predominantemente vítreos, cubren a las traquitas oscuras y tienen composiciones traquiandesíticas. La petrografía y geoquímica establecen una estrecha relación con las traquitas claras. El único cuerpo dómico en el área es el cerro Colorado, cuya composición corresponde a una riolita peralcalina ó comendita; una edad K/Ar de 24 ± 1 Ma establece por primera vez su relación temporal. La unidad efusiva más joven corresponde a lavas basálticas, agrupadas en afíricas y porfíricas. Se propone designar a las primeras como basaltos olivínicos transicionales en tanto que los basaltos porfíricos se subdividen en basaltos olivínicos alcalinos y hawaiitas. Los datos estratigráficos y geoquímicos sugieren que la asociación volcánica estudiada es el resultado de al menos dos etapas evolutivas. Una de ellas incluye los basaltos, traquitas claras, flujos claros y comenditas que muestran un patrón de cristalización fraccionada. Las traquitas oscuras, más viejas, corresponderían a otro estadio evolutivo.

  14. PRECENCIA DE LOS NEGROS EN SANTA MARTA

    Directory of Open Access Journals (Sweden)

    Edgar Rey Sinning

    2002-08-01

    Full Text Available Partimos de señalar que las investigaciones sobre los negros en la Provincia de Santa Marta, son escasas; sin embargo, podemos afirmar que dos trabajos dan cuenta de su presencia en la ciudad y en todo su territorio. El primero, de ellos es la reciente publicación sobre la esclavitud entre los años 1791- 1851, de Dolcey Romero Jaramillo que revisa el papel de los negros en dicha provincia y ciudad. El otro es nuestro estudio sobre 10s negros llegados a Santa Marta desde el Departamento de Bolívar, en la década de los 80 del siglo pasado, titulado "Cristo Rey: Un Espacio para permanecer en el Tiempo". El presente artículo elabora una cronología de la presencia de los negros esclavos que llegaron a Santa Marta desde 1525, año de su fundación. Se señala cómo durante los primeros años se fueron autorizando dos (2 esclavos negros para algunas personas importantes, destinados a1 servicio doméstico. Política que se comienza a modificar a partir de 1535, cuando se le autorizan cien (100 esclavos al Gobernador Pedro Fernández de Lugo, y desde entonces, es importante su presencia en oficios varios, sobre todo en las actividades de las haciendas cercanas a Santa Marta, hasta el siglo XIX. A finales de ese siglo y comienzos del XX, es significativa su vinculación a] muelle -más tarde puerto-, como "muelleros" o "portuarios", asumiendo la responsabilidad de garantizar las actividades de carga y descarga del puerto samario. Igualmente se muestra su papel determinante en la construcción de las líneas férreas que unirían a la ciudad-puerto con la "Zona Bananera". Es para esta última actividad, que se traen negros desde Jamaica conocidos como "yumecas", llamados "yumecas" por los samarios.

  15. Exploration and development of Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Teilman, M.A.; Cordon, U.J.

    1981-01-01

    A brief retrospective of the exploration and field model development at Cerro Prieto are presented. Representative field models are presented for each of the work phases. These models demonstrate how the concept of the field evolved - from a small 2 km/sup 2/ area with a relatively unknown reservoir configuration - to a geothermal resource area over 20 km/sup 2/ where the hydrothermal processes and structural environment are being studied in detail. A model integrating information from these studies was developed.

  16. Importaciones áticas del siglo V a.C. del Cerro del Prado (Algeciras, Cádiz

    Directory of Open Access Journals (Sweden)

    Cabrera, Paloma

    1996-12-01

    Full Text Available In this paper we analyze a group of Attic imports, found in the excavations of Cerro del Prado, a settlement situated in the Bahía de Algeciras (Cádiz. The great interest of this group lies in the fact that it belongs to a particular chronological period, the last third of the 5th century B.C., as we have not found later imports, and in the almost exclusive presence of black glazed vases, which gives US an idea of a very definitive demand of the punic society of the Iberian Peninsula regarding the trade of greek goods.

    Presentamos en este trabajo un conjunto de importaciones áticas halladas en las excavaciones del Cerro del Prado, situado en la bahía de Algeciras (Cádiz. El interés de este conjunto reside en su pertenencia a un momento cronológico muy concreto: el último tercio del siglo V a.C., no habiéndose hallado importaciones más modernas y en la presencia absoluta de vasos de barniz negro, lo que nos habla de una demanda muy determinada de la sociedad púnica peninsular frente al comercio de productos griegos.

  17. 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

  18. Being Negro in Recife Brazil: A Political Aesthetics Approach

    NARCIS (Netherlands)

    Leerzem, van L.; Nuijten, M.C.M.; Vries, de P.A.

    2015-01-01

    In this article, we explore the role of cultura negra and what it means to be negro for a particular segment of the population of Recife, Brazil. We zoom in on participants in Terça Negra (negro Tuesday), one of the foremost weekly events in the city. For these participants, self-identifying as negr

  19. 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

  20. 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.

  1. Archimboldi: El agujero negro de 2666

    Directory of Open Access Journals (Sweden)

    Felipe Ríos

    2014-12-01

    Full Text Available Este ensayo busca demostrar una hipótesis: que en la obra de Roberto Bolaño el tiempo será asumido como un viaje hacia el caos y la percepción de "desfases" en la estructura cronológica. Dicho enfoque se aplicará concretamente a 2666, la novela donde Bolaño expuso su mayor preocupación por la cuestión temporal, y en especial a "La parte de Archimboldi", donde se evidencia que el escritor alemán no sólo actuaría como un personaje que, debido al hechizo de sus novelas, provoca su ulterior persecución, sino que opera como un verdadero "agujero negro", capaz de fagocitar toda circunstancia estética y vivencial que gire a su alrededor.

  2. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba Petrotectonic evolution of the Cerro Aspero mining district and emplacement model of the wolframiferous deposits, Córdoba

    OpenAIRE

    D. Mutti; S. González Chiozza

    2005-01-01

    La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4) y estructuras penetrativas (S2, S3 y S4) que se desarrollaron desde el...

  3. La presencia de Negros en la Nordpatagonia. 1779-1837

    Directory of Open Access Journals (Sweden)

    Dora Noemí Martínez de Gorla

    2003-12-01

    Full Text Available This paper studies the juridical and social effects created by the individual assimilation of the slave and freeperson in the Rio Negro and the massive entrance of blacks during the war with Brazil, a historic moment when differences were established between African blacks and American blacks. This distinction was modified with the decree of September 12, 1827, when such distinctions were abolished.//Este trabajo estudia los efectos jurídicos y sociales creados por la asimilación individual del esclavo y de la persona libre en el Rio Negro y la entrada masiva de africanos durante la guerra con Brasil, momento histórico en el que las diferencias entre africanos negros y americanos negros fueron establecidas. Esta distinción fue modificada con el decreto 12 de 1827, cuando se abolieron tales diferencias.

  4. Evaluation of geologic characteristics at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Halfman, S.E.; Vonder Haar, S.P.

    1981-01-01

    Computerized well-log analysis of Cerro Prieto has led to the identification of a relatively large and irregular low-density volume extending from near the surface in the vicinity of Laguna Volcano to greater depths toward the northeast. This low-density volume is located about a plane of symmetry of a self-potential anomaly and a group of northeast trending active faults. The presence of a volume of relatively high-density rock has been recognized at shallow depths in the initially developed part of the resource. It is believed to be due to minerals deposited by cooled, rising geothermal brine. Storativity calculated from well logs at the south end of the western part of the field shows acceptable comparison with storativity calculated from well tests. The amount of fluid produced from the field during the period 1973-1977 is greater than the amount in situ calculated from the completed interval thicknesses. Because this part of the field is still producing today, fluid must be recharging this part of the field.

  5. Optical atmospheric extinction over Cerro Paranal

    CERN Document Server

    Patat, F; O'Brien, K; Pompei, E; Bensby, T; Carraro, G; Postigo, A de Ugarte; Fox, A; Gavignaud, I; James, G; Korhonen, H; Ledoux, C; Randall, S; Sana, H; Smoker, J; Stefl, S; Szeifert, T

    2010-01-01

    Aims: The present study was conducted to determine the optical extinction curve for Cerro Paranal under typical clear-sky observing conditions, with an accuracy of 0.01 mag/airmass. Methods: The extinction curve of Paranal was obtained through low-resolution spectroscopy of 8 spectrophotometric standard stars observed with FORS1 mounted at the 8.2 m Very Large Telescope, covering a spectral range 3300-8000 A. A total of 600 spectra were collected on more than 40 nights distributed over six months, from October 2008 to March 2009. The average extinction curve was derived using a global fit algorithm, which allowed us to simultaneously combine all the available data. The main atmospheric parameters were retrieved using the LBLRTM radiative transfer code, which was also utilised to study the impact of variability of the main molecular bands of O2, O3, and H2O, and to estimate their column densities. Results: In general, the extinction curve of Paranal appears to conform to those derived for other astronomical si...

  6. Estratigrafía y petrología del sector noreste de sierra de Apas. Provincia del Chubut Stratigraphy and petrology of the Northeastern sector of Sierra de Apas. Chubut Province

    OpenAIRE

    M. Remesal; F.M. Salani; G.I. Massaferro; M.E. Cerredo

    2004-01-01

    La sierra de Apas, ubicada entre las provincias de Rio Negro y Chubut, forma parte del magmatismo de intraplaca emplazado durante el Paleogeno-Neógeno en el norte de la Patagonia extrandina. En el sector noreste se ha definido una estratigrafía integrada por: traquitas oscuras, flujos piroclásticos, traquitas claras, domos riolíticos y basaltos porfíricos y afíricos. Las traquitas oscuras, son relativamente más antiguas, tienen bajo porcentaje de fenocristales, y clasifican como traquitas- be...

  7. Estratigrafía y petrología del sector noreste de sierra de Apas. Provincia del Chubut

    OpenAIRE

    M. Remesal; F.M. Salani; G.I. Massaferro; M.E. Cerredo

    2004-01-01

    La sierra de Apas, ubicada entre las provincias de Rio Negro y Chubut, forma parte del magmatismo de intraplaca emplazado durante el Paleogeno-Neógeno en el norte de la Patagonia extrandina. En el sector noreste se ha definido una estratigrafía integrada por: traquitas oscuras, flujos piroclásticos, traquitas claras, domos riolíticos y basaltos porfíricos y afíricos. Las traquitas oscuras, son relativamente más antiguas, tienen bajo porcentaje de fenocristales, y clasifican como traquitas- be...

  8. Analisis neotectónico del área Cerro Salinas, departamento Sarmiento, provincia de San Juan Neotectonic analysis of the Cerro Salinas area, Sarmiento department, province of San Juan

    Directory of Open Access Journals (Sweden)

    Héctor Cisneros

    2010-12-01

    Full Text Available El cerro Salinas es una de las exposiciones más australes del basamento cristalino de las Sierras Pampeanas. Alrededor del mismo han sido reconocidos varios trazos de fallas caracterizados por escarpas rectilíneas de dirección submeridiana, que afectan a depósitos sedimentarios referidos al Terciario y Cuaternario. La actitud espacial de las fallas neotectónicas está controlada por la posición de la estratificación y de los contactos litológicos principales de las unidades terciarias, lo cual se ha interpretado preliminarmente como evidencia del flexodeslizamiento asociado al acortamiento andino. Esta situación guarda mucha similitud con el estilo de deformación de las principales zonas de fallamiento cuaternario de la Precordillera Oriental. Acorde con la distribución espacial de las deformaciones neotectónicas y de la geometría de las mismas, se dividió al área analizada en tres sectores. La principal estructura neotectónica, la falla Cerro Salinas, constituye el límite oeste tanto del cerro Salinas como de los afloramientos precuaternarios circundantes con una longitud reconocida de 15,77 km. Las observaciones realizadas en el área de estudio, principalmente al norte del mismo permiten indicar que la deformación en el frente de falla está vinculada a escarpas asociadas con fallas inversas propagantes. La discriminación cronológica de las unidades morfoestratigráficas cuaternarias se realizó en base a datos de multiparámetros y a la signatura de las superficies aluviales en imágenes Landsat ETM+ y ASTER, mediante procesamiento en base al método de componentes principales. En base a la sumatoria del desplazamiento vertical desarrollado por las escarpas de falla para el Pleistoceno tardío, se ha estimado una tasa de levantamiento mínima de 0,13 mm/año.The so called Cerro Salinas is one of the southernmost expressions of the Sierras Pampeanas crystalline basement. Several fault traces with N-S-trending rectilinear

  9. The Negro in the Drugstore Industry. The Racial Policies of American Industry.

    Science.gov (United States)

    Fletcher, F. Marion; Keeney, Marie R.

    This study examines the historical and current levels of Negro employment in drugstores, the reasons for the employment patterns, the prospects for greater Negro employment in high status jobs, and the effects of industry employment policies on the retail drug industry employment of Negroes. The report explores the nature of the retail drug…

  10. Report of boring made in the South of Cerro Largo district (Cerro Largo) 1977-1978

    International Nuclear Information System (INIS)

    The present work are within the framework and compiles the data obtained by means of the study of the perforations executed in the District Cerro Largo Sur of the detailed prospection of uranium minerals. This study was carried out by technicians of Geologic ex--Institute of Uruguay (IGU) - at the moment National Direction of Mining and Geology. (DINAMIGE). The works began at the beginning of 1977 and continued until 1978 July; The headquarters of the program of prospection of uranium was carried out by Ing. Hector Goso. In this report the conclusions drawn at the time of the detection of the works in the District already published, as well as the litologicos cuts of all the executed perforations are included

  11. Herpetofauna del Cerro Guiengola, Istmo de Tehuantepec, Oaxaca

    OpenAIRE

    Cintia Natalia Martín-Regalado; Rosa Ma. Gómez-Ugalde; Ma. Emma Cisneros-Palacios

    2011-01-01

    Este estudio se realizó en el Cerro Guiengola, Tehuantepec, Oaxaca, con el objetivo de contribuir al conocimiento de la herpetofauna en dicha área. Se obtuvieron 602 registros visuales y se recolectaron 103 ejemplares de anfibios y reptiles durante 60 días de trabajo de campo. Se enlistan 40 especies, pertenecientes a 33 géneros y 18 familias. Se determinó la distribución de la herpetofauna en el Cerro Guiengola por microhábitat, tipo de vegetación y altitud. Usando el método de Jaccard se el...

  12. 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.

  13. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba

    OpenAIRE

    D. Mutti; S. González Chiozza

    2005-01-01

    La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4) y estructuras penetrativas (S2, S3 y S4) que se desarrollaron desde el...

  14. O negro e a cultura afrodescendente na dramaturgia cubana

    OpenAIRE

    Marcos Antônio Alexandre

    2015-01-01

    Este artigo tem como objetivo analisar como o negro e a sua cultura integram a dramaturgia cubana contemporânea, observando aspectos relacionados às questões das identidades e à discussão da memória pessoal e coletiva, tendo como foco de análise alguns textos do autor Eugenio Hernández Espinosa.

  15. Guerreiro Ramos: o personalismo negro Guerreiro Ramos: black personalism

    Directory of Open Access Journals (Sweden)

    Muryatan Santana Barbosa

    2006-11-01

    Full Text Available Baseando-se em pesquisa recém-finalizada sobre a trajetória intelectual do sociólogo Alberto Guerreiro Ramos (1915-1982 (cf. Barbosa, 2004, este ensaio apresenta a filosofia política do personalismo negro, cerne do pensamento de Guerreiro Ramos acerca do negro brasileiro e mundial. Ademais, tratar-se-á de estabelecer, sucintamente, a proximidade de tal visão humanista do negro com recentes perspectivas multiculturalistas e pós-coloniais, a fim de mostrar a contemporaneidade desta contribuição de Guerreiro Ramos à teoria social e à práxis dos movimentos negros.As a result of nearly a finished research about the intellectual performance of the sociologist Alberto Guerreiro Ramos (1915-1982, this paper envisages the political philosophy of black personalism. This was the kern of Guerreiro Ramos thought about Brazilian and World-dimensioned Black. An attempt is made to connect this humanistic vision of Blackmen with recent multiculturalist and postcolonial visions, in order to point out the present day contribution of Guerreiro Ramos to social theory and praxis of Black movements.

  16. 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.

  17. Microestructuras de deformación en rocas granulíticas, Cerro La Crespa, Tandilia, Provincia de Buenos Aires

    Directory of Open Access Journals (Sweden)

    Lucrecia Jorgensen

    2008-06-01

    Full Text Available El cerro La Crespa, localizado un kilómetro al sur de la megacizalla de Azul, integra las sierras de Azul, las cuales componen parte del Sistema de Tandilia. El presente trabajo trata sobre el estudio petrográfico-microestructural, donde se determina la composición modal y arreglos texturales a escala de grano y una primera caracterización geoquímica de rocas granulíticas aflorantes en el sector NO del cerro La Crespa. A partir de tales análisis, se intenta dilucidar los mecanismos de deformación actuantes y las condiciones metamórficas alcanzadas. Se reconocen rocas con texturas granoblásticas de composición básica e intermedia. Dichas rocas evidencian deformación frágil-dúctil heterogénea, con desarrollo de fábricas miloníticas, acaecida luego de que el evento metamórfico alcanzara su máximo desarrollo. Las texturas primitivas y la asociación de minerales anhidros presentes indicarían que dichas rocas podrían ser consideradas dentro de la serie de las granulitas. En las milonitas se aprecian significativos cambios mineralógicos, ya que al aumentar la deformación se incrementa la proporción de minerales hidratados y simultáneamente se reduce la cantidad de minerales anhidros. Estas modificaciones hacen suponer que la deformación actuó bajo condiciones metamórficas medias a altas, en facies de anfibolita superior-granulita inferior. Esta interpretación está apoyada por los mecanismos de deformación observados, a saber, recristalización dinámica de feldespatos, piroxenos, anfíboles, biotita y cuarzo; elongación de piroxenos y desarrollo de microboudinage.

  18. Mineralización de uranio en la Sierra de Velasco, La Rioja

    Directory of Open Access Journals (Sweden)

    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.

  19. A poesia ‘é-sou’ negra = Negro poetry

    Directory of Open Access Journals (Sweden)

    José Pires Laranjeira

    2010-01-01

    Full Text Available Os diversos cânones da poesia brasileira não contemplam a poesia negrobrasileira como deveria ser. Sendo o poeta Luiz Gama ainda hoje menosprezado, em comparação com Castro Alves, é necessário, pois, colocá-lo no seu verdadeiro lugar de significação. Porém, esse esforço deve servir também para compreender que Gama, na sua poesia, ainda mostra alguma conformidade com certos preconceitos rácicos próprios do século XIX e que se encontram, por exemplo, em poetas angolanos. Já o poeta Solano Trindade, devido à sua formação ideologicamente comprometida com os pobres e miseráveis da sociedade, trata o negro como um ser social, econômico e cultural de corpointeiro, concepção aprofundada por Cuti, que, finalmente, deixa de apelidar o mestiço de mulato, segundo a conformidade com o Movimento Negro. Por outro lado, é um poeta da modernidade mais avançada, quer formalmente, quer atingindo o âmago do subconsciente negro, ao versar o seu sofrimento íntimo, de modo inédito. Brazilian poetry’s several literary canons fail to fully investigate Brazilian Black Poetry as it should be. In spite of the fact that the poet Luiz Gama is currently not in the limelight when compared to Castro Alves, the replacing of his real place of significance is actually worthwhile. This effort should also be needed to understand that Gama in his poetry shows a type of conformity with certain racial bias common in the 19th century as, for example, in the poetry of Angola. On the other hand, due to his ideologically committed ideology with the poor and destitute in society, the poet Solano Trindade deals with the Negro as a social, economical and cultural person. This concept is partook by Cuti who, at long last, do not call the half-breed as ‘mulato’, following orientations of the Negro Movement. On the other hand, he is formally poet featuring themost advanced modernity as he reaches the heart of the Negro subconscious in his singing of deep

  20. Analisis neotectónico del área Cerro Salinas, departamento Sarmiento, provincia de San Juan

    Directory of Open Access Journals (Sweden)

    Héctor Cisneros

    2010-12-01

    Full Text Available El cerro Salinas es una de las exposiciones más australes del basamento cristalino de las Sierras Pampeanas. Alrededor del mismo han sido reconocidos varios trazos de fallas caracterizados por escarpas rectilíneas de dirección submeridiana, que afectan a depósitos sedimentarios referidos al Terciario y Cuaternario. La actitud espacial de las fallas neotectónicas está controlada por la posición de la estratificación y de los contactos litológicos principales de las unidades terciarias, lo cual se ha interpretado preliminarmente como evidencia del flexodeslizamiento asociado al acortamiento andino. Esta situación guarda mucha similitud con el estilo de deformación de las principales zonas de fallamiento cuaternario de la Precordillera Oriental. Acorde con la distribución espacial de las deformaciones neotectónicas y de la geometría de las mismas, se dividió al área analizada en tres sectores. La principal estructura neotectónica, la falla Cerro Salinas, constituye el límite oeste tanto del cerro Salinas como de los afloramientos precuaternarios circundantes con una longitud reconocida de 15,77 km. Las observaciones realizadas en el área de estudio, principalmente al norte del mismo permiten indicar que la deformación en el frente de falla está vinculada a escarpas asociadas con fallas inversas propagantes. La discriminación cronológica de las unidades morfoestratigráficas cuaternarias se realizó en base a datos de multiparámetros y a la signatura de las superficies aluviales en imágenes Landsat ETM+ y ASTER, mediante procesamiento en base al método de componentes principales. En base a la sumatoria del desplazamiento vertical desarrollado por las escarpas de falla para el Pleistoceno tardío, se ha estimado una tasa de levantamiento mínima de 0,13 mm/año.

  1. Criteria for determining casing depth in Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Olivas M., H.M.; Vaca S., J.M.E.

    1982-08-10

    On the basis of geological data obtained during drilling and its relation to electric logs, together with the problems that arose when drilling through formations until the production zone was reached, it is possible to establish the most suitable manner to line a well and thus formulate an optimum casings program. The main criteria to be taken into consideration in preparing such a program and its application in the drilling of wells programmed in Cerro Prieto to optimize and economize such drilling and achieve suitable techniques for well completion are presented. The criteria are based on the characteristics of the Cerro Prieto field and on casing design factors, as well as a experience gained during drilling in such a field.

  2. Dating thermal events at Cerro Prieto using fission track annealing

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, S.J.; Elders, W..

    1981-01-01

    Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures.

  3. Early mineralization at Cerro de Pasco (central Peru) revisited

    OpenAIRE

    Rottier, Bertrand; Casanova, Vincent; Fontboté, Lluis; Kouzmanov, Kalin; Alvarez, Hugo; Bendezú, Ronner

    2013-01-01

    The large Cerro de Pasco Cordilleran base metal deposit in central Peru is located on the eastern margin of a Middle Miocene diatreme-dome complex. A striking characteristic is the presence of a N-S trending massive funnel-shape pyrite-quartz replacement ore body that contains pyrrhotite pipes grading outwards to lead-zinc replacement bodies, along the eastern contact of the diatreme-dome complex. Earlier workers interpreted the pyrrhotite pipes as postdating the pyritequartz body. This study...

  4. The Cerro LOS Calvos and La Banderia chondrites

    Science.gov (United States)

    Whitlock, Randall; Lewis, Charles F.; Clark, James C.; Moore, Carleton B.

    1991-06-01

    The Cerro los Calvos meteorite is a single stone of 68.5 g found in the Nuevo Mercurio strewn field of Zacatecas, (Mexico). It is an unusual H4 chondrite. Its olivine (Fa12.5) and orthopyroxene (Fs 11.7, Wo 0.8) are reduced relative to typical H chondrites. The La Banderia meteorite of 54.3 g from the same vicinity is an LL5 chondrite of shock classification e.

  5. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Vonder Haar, S.

    1980-01-01

    To aid in a paleoenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495 m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. We found foraminifera in 6 samples, ostracodes in 19 samples, and nannoplankton as coccoliths in 24 samples. Other groups, such as molluscs, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations are not possible at this time because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350{sup 0}C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to brackish water environments that correspond, in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-My-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500 m deep, is perplexing. These are not laboratory contaminates and, as yet, have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  6. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Haar, S.V.

    1982-08-10

    To aid in a paleonenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. Foraminifera was found in 6 samples, ostracodes in 19 samples and mannoplankton as coccoliths in 24 samples. Other groups, such as molluscus, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations at this time cannot be made because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350/sup 0/C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to backish water inviroments that correspond in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-m.y.-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500m deep, is perplexing. These are not laboratory contaminates and, as yet have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  7. Current state of the hydrothermal geochemistry studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Fausto L, J.J.; Jimenez S, M.E.; Esquer P, I.

    1981-01-01

    The current state of hydrothermal geochemistry studies being carried out at the field are reported. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. Data are presented on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from SiO/sub 2/. Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates).

  8. Buracos negros primordiais e astrofísica observacional

    Science.gov (United States)

    Custódio, P. S.; Horvath, J. E.

    2003-02-01

    A história da física contemporânea é pródiga em grandes descobertas (a Relatividade e a Mecânica Quântica entre as mais importantes) até meados dos anos '30. O peso destes desenvolvimentos é tão grande que outros feitos de grande porte (por exemplo, a teoria da nucleossíntese nas estrelas) são geralmente considerados como "filhotes" dos primeiros, ao menos na imaginação popular. Porém, algumas exceções à regra não-escrita são dignas de menção. Entre estas últimas está a descoberta por S.W.Hawking e colaboradores das propriedades de emissão dos buracos negros, trabalho que iniciou uma disciplina com vida própria denominada Termodinâmica de Buracos Negros.

  9. Analysis and simulatin of rock avalanche sequence in the Cerro Caquilluco landslide (Tacna, Peru)

    Science.gov (United States)

    Crosta, Giovanni B.; Frattini, Paolo; Valbuzzi, Elena; Hermanns, Reginald L.

    2014-05-01

    The Cerro Caquilluco (Tacna, Peru) rock avalanche complex has a total volume of about 15 km3 and a length of 43 km, extending from 3900 m a.s.l to 530 m a.s.l.. Based on geomorphological interpretation and lithological evidences, we reconstructed a possible rock-avalanches sequence consisting of at least nine major events. For each event, we calculated the mobilized volumes through the comparison of pre- and post-failure morphology. We argue that the first rock avalanche event corresponds to the Cerrillos Negros rock avalanche, characterized by a distal tongue shaped lobe, 11 km long, 3 km wide and 25 to 60 m thick (rough volume estimate 1.15 km3), deposited along the piedmont surface (average slope: 2° ). The reconstruction of pristine pre-failure morphology was accomplished by mimicking the preserved morphology close to the source area, and by removing the deposited volumes from the rock avalanche path. For this, we made the hypothesis that the old paleosurface was already eroded by valleys progressively moving upstream during a wetter climate, as suggested by Hoke et al (2007) for similar conditions in northern Chile. The reconstruction of the pre-event morphology required several attempts to fit the eroded and the deposited volumes. Finally, a total mobilized volume of about 10.2 km2 was obtained for this event. For the successive scenarios of slide retrogression, we used the morphologies obtained by previous scenarios as pre-failure morphologies, and we calculated, by difference with current topography, the lobe volumes. The volumes of single rock avalanche episodes decrease from the first to the last event, roughly following a power-law decay. This behavior is comparable to that described by Utili and Crosta (2011) for retrogressive instabilities in rocky cliffs. The rock-avalanche events have been simulated, to verify the different scenarios in terms of spreading area and maximum runout, by using SPH (Smooth Particle Hydrodynamics) and Finite Element codes

  10. O negro e a cultura afrodescendente na dramaturgia cubana

    Directory of Open Access Journals (Sweden)

    Marcos Antônio Alexandre

    2015-10-01

    Full Text Available Este artigo tem como objetivo analisar como o negro e a sua cultura integram a dramaturgia cubana contemporânea, observando aspectos relacionados às questões das identidades e à discussão da memória pessoal e coletiva, tendo como foco de análise alguns textos do autor Eugenio Hernández Espinosa.

  11. Amerindian agriculture in an urbanising Amazonia (Rio Negro, Brazil)

    OpenAIRE

    Emperaire, Laure; Eloy, L.

    2015-01-01

    This article explores the transformations undergone by indigenous agricultural systems in periurban areas of the Rio Negro (Amazonas, Brazil). Rather than losing their characteristics, these systems have basically been transposed from a forest context to periurban areas, maintaining multi-plot cultivation, dynamic management of agrobiodiversity and traditional knowledge. But this agriculture is confronted by the values of modernity embedded in urban agriculture. The recognition of the ecologi...

  12. 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

  13. Seismotectonics of the Cerro Prieto Geothermal Field, Baja California, Mexico.

    Science.gov (United States)

    Rebollar, C. J.; Reyes, L. M.; Quintanar, L.; Arellano, J. F.

    2002-12-01

    We studied the background seismic activity in the Cerro Prieto geothermal field (CPGF) using a network of 21 digital stations. Earthquakes are located below the exploitation area of the CPGF, between 3 and 12 km depth, within the basement. Earthquakes follow roughly a N30°E trend perpendicular to the Cerro Prieto fault. This activity is located on a horst-like structure below the geothermal field and coincides with the zone of maximum subsidence in the CPGF. Two earthquake swarms occurred along the SE-NW strike of the Cerro Prieto fault and in the neighborhood of the Cerro Prieto volcano. Magnitudes range from -0.3 to 2.5. A Vp/Vs=1.91 ratio of the activity below the volcano suggests a water-saturated medium and/or a partial-melt medium. We calculated 76 focal mechanisms of individual events. On June 1 and September 10, 1999, two earthquakes of Mw 5.2 and 5.3 occurred in the basement at depths of 7.4 and 3.8 km below the CPGF. Maximum peak accelerations above the hypocenter ranged from 128.0 to 432.0 cm/s2. Waveform modeling results in a fault geometries given by strike=236°, dip=60°, rake=-58° (normal) and strike=10°, dip=90°, rake=159° (right lateral strike-slip) for the June and September events. Observed triangular source time function of 0.7 seconds and a double source with a total duration of 1.9 seconds for the June and September events were used to calculate the synthetics seismograms. Static stress drops and seismic moments for the June and September events are: Δ\\sigma=82.5 MPa (825 bars), Mo= 7.65x1016 Nm (7.65x1023 dyne-cm) and Δ\\sigma=31.3 MPa (313 bars) and Mo=1.27x1017 Nm (1.27x1024 dyne-cm). These stress drops are typical of continental events rather than stress drops of events originated in spreading centers. We concluded from the focal mechanisms of the background seismicity and June and September 1999 events, that a complex stress environment exits in the CPGF due to the continual thinning of the crust in the Cerro Prieto basin.

  14. 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...

  15. Microestructuras de deformación en rocas granulíticas, Cerro La Crespa, Tandilia, Provincia de Buenos Aires Deformation microstructures in granulitic rocks, Cerro La Crespa, Tandilia, province of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Lucrecia Jorgensen

    2008-06-01

    Full Text Available El cerro La Crespa, localizado un kilómetro al sur de la megacizalla de Azul, integra las sierras de Azul, las cuales componen parte del Sistema de Tandilia. El presente trabajo trata sobre el estudio petrográfico-microestructural, donde se determina la composición modal y arreglos texturales a escala de grano y una primera caracterización geoquímica de rocas granulíticas aflorantes en el sector NO del cerro La Crespa. A partir de tales análisis, se intenta dilucidar los mecanismos de deformación actuantes y las condiciones metamórficas alcanzadas. Se reconocen rocas con texturas granoblásticas de composición básica e intermedia. Dichas rocas evidencian deformación frágil-dúctil heterogénea, con desarrollo de fábricas miloníticas, acaecida luego de que el evento metamórfico alcanzara su máximo desarrollo. Las texturas primitivas y la asociación de minerales anhidros presentes indicarían que dichas rocas podrían ser consideradas dentro de la serie de las granulitas. En las milonitas se aprecian significativos cambios mineralógicos, ya que al aumentar la deformación se incrementa la proporción de minerales hidratados y simultáneamente se reduce la cantidad de minerales anhidros. Estas modificaciones hacen suponer que la deformación actuó bajo condiciones metamórficas medias a altas, en facies de anfibolita superior-granulita inferior. Esta interpretación está apoyada por los mecanismos de deformación observados, a saber, recristalización dinámica de feldespatos, piroxenos, anfíboles, biotita y cuarzo; elongación de piroxenos y desarrollo de microboudinage.This work deals with a petrographic- microstructural study in order to determine the modal composition and textural arrangement on a grain scale and the first geochemistry characterization of granulitic rocks on the NW of the cerro La Crespa, which is located about 1 km south of the Azul Megashear and forms part of the sierras de Azul in the Tandilia System

  16. 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

  17. The Social Pathology Model: Historical Bases for Psychology's Denial of the Existence of Negro Culture.

    Science.gov (United States)

    Baratz, Joan C.; Baratz, Stephen S.

    The absence of a meaningful conception of Negro culture has forced the interpretation of almost all psychology's data on the Negro into two seemingly dichotomous categories: either that of biological incapacity, i.e., genetic inferiority, or social deviance and pathology, i.e., environmental deprivation. The cultural difference theory asserts that…

  18. A Context for the Birth of "The Journal of Negro Education"

    Science.gov (United States)

    Gordon, Edmund W.

    2007-01-01

    "The Journal of Negro Education" was born during the third decade of the 20th century. "The Journal" has reflected concern with race and racial discrimination as a central problem in the education of Negro people. During its 75th anniversary, the legacy of "The Journal" continues and has remained the educational, societal, and economic outlet for…

  19. DIMENSIONS OF ACHIEVEMENT-RELATED BEHAVIOR AMONG LOWER-CLASS NEGRO PARENTS.

    Science.gov (United States)

    SOLOMON, DANIEL; AND OTHERS

    A STUDY OF ACHIEVEMENT-RELATED BEHAVIOR SOUGHT TO IDENTIFY PARENT BEHAVIOR AS A SOURCE OF VARIANCE WITHIN A HOMOGENEOUS GROUP OF CHILDREN. SUBJECTS WERE 72 SETS OF NEGRO PARENTS OF FIFTH-GRADE CHILDREN IN A PREDOMINANTLY LOWER-CLASS NEGRO SCHOOL. THE INTERACTIONS OF PARENTS AND CHILD AS THE YOUNGSTER SOLVED EIGHT TASKS WERE OBSERVED IN THE HOME BY…

  20. The Negro in the Tobacco Industry. The Racial Policies of American Industry.

    Science.gov (United States)

    Northrup, Herbert R.; Ash, Robert I.

    The tobacco industry has employed Negroes since its inception in Colonial Virginia. This study is primarily concerned with the course of Negro employment and industry racial policies in the industry processing, manufacturing, selling, and distributing of cigarettes and manufactured tobacco, as distinct from the cigar industry which involves quite…

  1. 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.

  2. A trajetória do negro na literatura brasileira

    Directory of Open Access Journals (Sweden)

    Domício Proença Filho

    2004-04-01

    Full Text Available ESTE ARTIGO busca traçar o percurso do negro na literatura brasileira, como objeto, numa visão distanciada, e como sujeito, numa atitude compromissada. Destaca, de um lado, textos literários sobre o negro e, de outro, literatura do negro. Identifica, na produção literária ao longo do processo literário brasileiro, estereótipos reduplicadores da visão preconceituosa, explícita ou velada. Procura marcar a ultrapassagem do estereótipo e a assunção do negro como sujeito do seu discurso e de sua ação em defesa da identidade cultural. Nessa direção, seleciona autores e textos representativos produzidos notadamente a partir dos anos de 1970, momento de efervescência dos movimentos de auto-afirmação da etnia. Discute a designação literatura negra, entendida como aparentemente valorizadora, mas passível de converter-se em risco de fazer o jogo do preconceito velado.THIS ARTICLE outlines the trajectory of blacks in Brazilian literature, both as an object, with a distant perspective, and as a subject, with a more assertive attitude. As result it addresses the literary text on blacks, on the one hand; and by Blacks, on the other. It identifies a long history of stereotypes, associated with a prejudice vision of Blacks, both explicitly and implicitly. It seeks to describe the moment of passage in wich the stereotype was overtaken by the affirmation of blacks as subjects of their discourse, acting in defense of own cultural worth and identity. It selects a number of representative authors and texts starting in the 1970s, a particularly vital moment of Black conciousness affirmation in Brazil. It then argues the propriety of styling ablack literature, superficially presented as a positive affirmation, but pregnant of being turned into a form of implicit prejudice.

  3. 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

  4. Characterization of pottery from Cerro de Las Ventanas, Zacatecas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-del-Rio, H.; Mireles-Garcia, F. [Unidad Academica de Estudios Nucleares, UAZ, Zacatecas (Mexico); Mendez-Cardona, R.Y. [Unidad Academica de Antropologia, UAZ, Zacatecas (Mexico); Nicolas-Caretta, M. [INAH Delegacion Zacatecas (Mexico); Coordinacion de Ciencias Sociales y Humanidades, UASLP, Fracc. Talleres, SLP (Mexico); Speakman, R.J. [Museum Conservation Inst., Smithsonian Institution, Suitland, MD (United States); Glascock, M.D. [Research Reactor Center, Univ. of Missouri, Columbia, MO (United States)

    2009-09-15

    With the aim of classifying prehispanic pottery from Cerro de Las Ventanas site, Juchipila, Zacatecas, Mexico, instrumental neutron activation analysis (INAA) was used to analyze ceramic samples at the University of Missouri Research Reactor Center. Thirty-two chemical elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Two multivariate statistical methods, cluster analysis and principal component analysis, were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Mesoamerican ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Malpaso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de Las Ventanas represent a new and unique chemical fingerprint in the region. (orig.)

  5. Hydrocarbons emissions from Cerro Prieto Geothermal Power Plant, Mexico

    Science.gov (United States)

    Navarro, Karina; Navarro-González, Rafael; de la Rosa, José; Peralta, Oscar; Castro, Telma; Imaz, Mireya

    2014-05-01

    One of the most important environmental issues related to the use of geothermal fluids to generate electricity is the emission of non-condensable gases to the atmosphere. Mexico has one of the largest geothermal plants in the world. The facility is located at Cerro Prieto, Baja California, roughly 30 km south of Mexicali and the international boundary between Mexico and United States. The Cerro Prieto power plant has 13 units grouped on four individual powerhouses. Gas samples from 9 units of the four powerhouses were collected during 4 campaigns conducted in May-July, 2010, February, 2012, December, 2012, and May, 2013. Gas samples from the stacks were collected in 1000 ml Pyrex round flasks with Teflon stopcocks, and analyzed by gas chromatography-mass spectrometry. Methane was the most abundant aliphatic hydrocarbon, with a concentration that ranged from less than 1% up to 3.5% of the total gas mixture. Normal alkanes represented the second most abundant species, and displayed a decreasing abundance with increasing carbon number in the homologous series. Isoalkanes were also present as isobutane and isopentane. Cycloalkanes occurring as cyclopentane and cyclohexane, were detected only at trace level. Unsaturated hydrocarbons (alkenes and alkynes) were not detected. Benzene was detected at levels ranging from less than 1% up to 3.4% of the total gas mixture. Other aromatic hydrocarbons detected were toluene, and xylenes, and were present at lower concentrations (

  6. Characterization of pottery from Cerro de Las Ventanas, Zacatecas, Mexico

    International Nuclear Information System (INIS)

    With the aim of classifying prehispanic pottery from Cerro de Las Ventanas site, Juchipila, Zacatecas, Mexico, instrumental neutron activation analysis (INAA) was used to analyze ceramic samples at the University of Missouri Research Reactor Center. Thirty-two chemical elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Two multivariate statistical methods, cluster analysis and principal component analysis, were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Mesoamerican ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Malpaso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de Las Ventanas represent a new and unique chemical fingerprint in the region. (orig.)

  7. 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...

  8. 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...

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. Properties of Cerro Prieto rock at simulated in situ conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, J.F.

    1981-01-01

    Rocks from the Cerro Prieto Geothermal Field were tested under simulated in situ conditions in the laboratory to determine their properties and response to pore pressure reduction as would be caused by reservoir production. The primary purpose of the project was to provide information on compaction and creep as they may contribute to surface subsidence. Results show typical compressibilities for reservoir rocks of about 1 x 10/sup -6/ psi/sup -1/ and creep compaction rates of about 1 x 10/sup -9/ sec/sup -1/ when triggered by 1000 psi pore pressure reduction. This creep rate would cause significant porosity reduction if it continued for several years. Therefore it becomes important to learn how to correctly extrapolate such data to long times.

  14. Progress on the biphase turbine at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Cerini, D.; Hays, L.; Studhalter, W. [Douglas Energy Company, Placentia, CA (United States)

    1997-12-31

    The status of a Biphase turbine power plant being installed at the Cerro Prieto geothermal field is presented. The major modules for the power plant are completed except for a back pressure steam turbine. The power plant will be started in April 1997 with the Biphase turbine alone followed by the addition of the steam turbine module two months later. The current power plant performance level is 2780 kWe due to a decline in the well. An increase in power output to 4060 kWe by adding the flow from another well is planned. The addition of five Biphase power plants with a total power output of 21.2 megawatts is described.

  15. Results from two years of resistivity monitoring at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Wilt, M.J.; Goldstein, N.E.

    1981-01-01

    Dipole-dipole resistivity measurements for the combined purposes of reservoir delineation and resistivity monitoring were first made at Cerro Prieto in 1978 and have continued on an annual basis since then. Two 20 km long dipole-dipole lines with permanently emplaced electrodes at one kilometer spacings were established over the field area; one of these lines is remeasured annually. Resistivity measurements are taken using a 25 kW generator capable of up to 80A output and a microprocessor controlled signal averaging receiver; this high power-low noise system is capable of highly accurate measurements even at large transmitter-receiver separations. Standard error calculations for collected data indicate errors less than 5% for all points, but 95% confidence intervals show error limits about 2 to 4 times higher. Analysis of collected data indicate little change in the apparent resistivity of the upper 300 m over the field production zone and that in this section measurements are relatively insensitive to the annual rainfall cycle. Apparent resistivity increases were observed over the older producing zone at Cerro Prieto at depths of 1 km and greater. Large zones of decreasing apparent resistivity were observed flanking the zone of increases on both sides. The increase in apparent resistivity in the production region may be due to an increasing fraction of steam in the reservoir resulting from a production related decline in reservoir pressure. Alternatively the increases may be the result of fresh water influx from the Colorado River. The zone of declining resistivity flanking the area of increase may be due to the movement of saline waters into the reservoir region as a result of the pressure decline. Quantitative modeling of observed changes is impractical owing to the high uncertainty in estimating apparent resistivity changes and the nonuniqueness of models.

  16. The study of untreated syphilis in the Negro male

    International Nuclear Information System (INIS)

    Purpose: The participation of minorities in clinical studies is the subject of much discussion and has even become the subject of Federal law. The project known as the Tuskegee Syphilis Study and officially titled 'The Tuskegee Study of Untreated Syphilis in the Negro Male', is one of the great debacles of American medicine and a national shame. Despite the fact that its existence is well known, many do not know the historical facts of the study nor the context of the study. My purpose here is to recount the facts of the study and its historical context. Methods: The history recounted here is taken from documents gathered during a U.S. Senate investigation of the study, original papers located in National Library of Medicine, and books about the trial. Results: The trial began in 1931 as a survey of the natural history of untreated tertiary syphilis in Black men. This study enrolled 399 men with syphilis and 201 uninfected men to serve as controls. All were at least 25 years old at enrollment. The men were told they were in a study, but never educated about the implications. Later, men were not informed that there was a treatment for effective treatment for their disease - a treatment that was being withheld from them. This trial continued till 1972. Conclusion: Many of the issues that led to the study and caused it to continue for 40 years still exist. The lessons of the Public Health Study of Untreated Syphilis in the Untreated Negro include the dangers of paternalism, arrogance, blind loyalty, and misuse of science. 'Those who do not appreciate history are condemned to repeat it' (Alfred North Whitehead)

  17. Report of mortmorilloniticas clay in the Medina swamp (Cerro Largo district)

    International Nuclear Information System (INIS)

    This report describes the prospect ion work for the montmorillonitics clay in the region of Medina swamp in Cerro Largo district. The existence of new deposits was detected by cartography and geological study.

  18. Hidrogeologic and geophysical studies into Agro school Melo UTU Cerro Largo province

    International Nuclear Information System (INIS)

    The technical University UTU of Uruguay requested and Hidrogeologic study with the aim to analyze the factibility to discover underground stream waters which supply groundwaters into agro school Ing Agr. Alcides E Pintos Melo, Cerro Largo province.

  19. Comparison of Bender-Gestalt and WISC Correlations for Puerto Rican, White and Negro Children

    Science.gov (United States)

    Marmorale, Ann M.; Brown, Fred

    1975-01-01

    This study investigated whether a positive relationship between Bender-Gestalt performance and intelligence test scores would be found for Puerto Rican children and, as well, the generalizability of previous results obtained with Negro children. (Author/RK)

  20. Beta WAIS Comparison for Illiterate and Indigent Male and Female Negroes

    Science.gov (United States)

    Rochester, Dean E.; Bodwell, Aaron

    1970-01-01

    The feasibility of using the Revised Beta Examination for assessing the intellectual functioning level of indigent Negro adults is examined. Findings suggest that the Beta holds some promise. (Author)

  1. Geochemistry of igneous rocks from the Cerro Prieto geothermal field, northern Baja California, Mexico

    Science.gov (United States)

    Herzig, C. T.

    1990-08-01

    Fractional crystallization of basaltic magma, derived from an oceanic affinity source region present beneath the Salton Trough and emplaced into a pull-apart basin of this continental rift regime, produced a tholeiitic suite of hypabyssal rocks consisting of basalt, andesite and dacite within the Cerro Prieto geothermal field, located in northern Baja California, Mexico. Higher light-rare-earth-element abundances for a basalt from the Cerro Prieto geothermal field in comparison to basalts from the Gulf of California and the East Pacific Rise suggest partial assimilation of crustal materials into the parental magmas generated beneath the Salton Trough. The crustal contaminant may be present near the surface today in the form of granitoids of the Peninsular Ranges batholith, at deeper levels as hydrothermally altered materials near the base of the Salton Trough, or may be a relict feature of Tertiary subduction contained within the upper mantle beneath the Salton Trough. The Sr isotopic compositions of dacites from the nearby Cerro Prieto volcano range from 0.7029 to 0.7036, indicating an oceanic affinity source for these rocks. The suite of hypabyssal rocks of tholeiitic affinity present within the Cerro Prieto geothermal field, related by fractional crystallization, link the dacite volcano of Cerro Prieto to gabbroic plutons inferred to exist beneath the Cerro Prieto geothermal field.

  2. 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.

  3. Evidence of recent deep magmatic activity at Cerro Bravo-Cerro Machín volcanic complex, central Colombia. Implications for future volcanic activity at Nevado del Ruiz, Cerro Machín and other volcanoes

    Science.gov (United States)

    Londono, John Makario

    2016-09-01

    In the last nine years (2007-2015), the Cerro Bravo-Cerro Machín volcanic complex (CBCMVC), located in central Colombia, has experienced many changes in volcanic activity. In particular at Nevado del Ruiz volcano (NRV), Cerro Machin volcano (CMV) and Cerro Bravo (CBV) volcano. The recent activity of NRV, as well as increasing seismic activity at other volcanic centers of the CBCMVC, were preceded by notable changes in various geophysical and geochemical parameters, that suggests renewed magmatic activity is occurring at the volcanic complex. The onset of this activity started with seismicity located west of the volcanic complex, followed by seismicity at CBV and CMV. Later in 2010, strong seismicity was observed at NRV, with two small eruptions in 2012. After that, seismicity has been observed intermittently at other volcanic centers such as Santa Isabel, Cerro España, Paramillo de Santa Rosa, Quindío and Tolima volcanoes, which persists until today. Local deformation was observed from 2007 at NRV, followed by possible regional deformation at various volcanic centers between 2011 and 2013. In 2008, an increase in CO2 and Radon in soil was observed at CBV, followed by a change in helium isotopes at CMV between 2009 and 2011. Moreover, SO2 showed an increase from 2010 at NRV, with values remaining high until the present. These observations suggest that renewed magmatic activity is currently occurring at CBCMVC. NRV shows changes in its activity that may be related to this new magmatic activity. NRV is currently exhibiting the most activity of any volcano in the CBCMVC, which may be due to it being the only open volcanic system at this time. This suggests that over the coming years, there is a high probability of new unrest or an increase in volcanic activity of other volcanoes of the CBCMVC.

  4. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba Petrotectonic evolution of the Cerro Aspero mining district and emplacement model of the wolframiferous deposits, Córdoba

    Directory of Open Access Journals (Sweden)

    D. Mutti

    2005-03-01

    Full Text Available La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4 y estructuras penetrativas (S2, S3 y S4 que se desarrollaron desde el Pampeano hasta el Famatiniano inclusive, favoreciendo la intrusión anorogénica del batolito Cerro Áspero a partir del Devónico tardío. Como consecuencia del evento magmático fueron reactivadas las estructuras, movilizando fluidos hidrotermales por las anisotropías del terreno y debajo de un nivel de anfibolitas macizo que actuó como una barrera impermeable. La acción de un esfuerzo máximo s1 (330º contribuyó al desarrollo del sistema mineralizado siguiendo el patrón de fracturamiento del modelo de Riedel y propició la construcción del lineamiento mineral principal en una faja de cizalla simple dextral de posición 285º (S5. El fluido magmático - hidrotermal evolucionó mediante numerosos pulsos de ruptura y apertura de las inhomogeneidades rocosas, con sellado de cavidades por mecanismos de cierre con fracturamiento y relleno y disolución por presión. Estos mecanismos precipitaron sílice con hábito fibroso y reconcentraron elementos metálicos bajo un régimen de tracción y presión de fluido de poro estimada en 195 MPa. La edad de la mineralización de uno de sus estadios fue determinada en 343,8 ± 10,8 Ma, mediante una datación K/Ar en muscovita.Metalliferous mineralization, disseminated and in hydraulic breccias, in connection with a mining group composed of three swarm systems of quartz veinlets, veins and sills striking NNW, WNW and N, is exposed in the geological setting related to the Cerro Aspero granitic intrusion

  5. Uranium and Molybdenum extraction from a Cerro Solo deposit ore

    International Nuclear Information System (INIS)

    Cerro Solo, located in Chubut, Argentina, is a sandstone type uranium-molybdenum deposit. Good recovery of both elements can be achieved by acid leaching of the ore but the presence of molybdenum in pregnant liquors is an inconvenient to uranium separation and purification. A two steps process is developed. A selective alkaline leaching of the ore with sodium hydroxide allows separating and recovering of molybdenum and after solid-liquid separation, the ore is acid leached to recover uranium. Several samples averaging 0,2% uranium and 0,1% molybdenum with variable U/Mo ratio have been used and in both steps, leaching and oxidant reagents concentration, temperature and residence time in a stirred tank leaching have been studied. In alkaline leaching molybdenum recoveries greater than 96% are achieved, with 1% uranium extraction. In acid leaching up to 93% of the uranium is extracted and Mo/U ratio in solvent extraction feed is between 0,013 and 0,025. (author)

  6. Radon and ammonia transects across the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Semprini, L.; Kruger, P.

    1981-01-01

    Radon and ammonia transects, conducted at the Cerro Prieto geothermal field, involve measurement of concentration gradients at wells along lines of structural significance in the reservoir. Analysis of four transects showed radon concentrations ranging from 0.20 to 3.60 nCi/kg and ammonia concentrations from 17.6 to 59.3 mg/l. The data showed the lower concentrations in wells of lowest enthalpy fluid and the higher concentrations in wells of highest enthalpy fluid. Linear correlation analysis of the radon-enthalpy data indicated a strong relationship, with a marked influence by the two-phase conditions of the produced fluid. It appears that after phase separation in the reservoir, radon achieves radioactive equilibrium between fluid and rock, suggesting that the phase separation occurs well within the reservoir. A two-phase mixing model based on radon-enthalpy relations allows estimation of the fluid phase temperatures in the reservoir. Correlations of ammonia concentration with fluid enthalpy suggests an equilibrium partitioning model in which enrichment of ammonia correlates with higher enthalpy vapor.

  7. Performance of casings in Cerro Prieto production wells

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A, B.; Vital B, F.; Bermejo M, F.; Sanchez G, G.

    1981-01-01

    A careful evaluation of different production casings used at Cerro Prieto from 1964 to date has shown that the following casings have yielded particularly impressive results: 7 5/8-in. diameter, J-55, 26 lb/ft; 7 5/8-in. diameter, K-55, 45.3 lb/ft; and 5-in. diameter, K-55, 23.2 lb/ft. These casings differ from others of the same diameter but lighter weight which were also used at the field. The results are favorable in spite of severe construction problems, especially the loss of circulation during cementing operations, which we encountered in some of the wells where these casings were used. The use of gravity-fed fine sand as packing material and the arrangement of the production and intermediate casings were important in avoiding damage due to tension-compression stresses and, above all, damage due to internal or external corrosion over time. This situation is clearly evidenced if we compare the damage to the above casings with that experienced by grade N-80 production casings, especially in a corrosive environment.

  8. 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.

  9. 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

  10. 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...

  11. 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.

  12. Edad y rasgos petrográficos y geoquímicos de cuerpos subvolcánicos asignables a la Formación Cerro León, este del Macizo del Deseado, Santa Cruz Age and petrography and geochemistry features of subvolcanic outcrops from Cerro León Formation, east of the Deseado Massif, Santa Cruz

    Directory of Open Access Journals (Sweden)

    D. Guido

    2004-12-01

    Full Text Available Se presentan nuevos afloramientos de cuerpos subvolcánicos correlacionables con la Formación Cerro León en el sector oriental del Macizo del Deseado. Esta unidad aflora en dos sectores, en el bajo Leonardo y en el afloramiento Bahía Laura del Complejo Río Deseado. El primer sector presenta trece diques y un filón capa intruyendo a las sedimentitas pérmicas de la Formación La Golondrina y el segundo sector comprende tres diques que intruyen a rocas del basamento. Se trata de rocas de color gris a negro, frecuentemente alteradas, con textura microgranuda a porfírica, con fenocristales de plagioclasa, diópsido (En42 Fs11 Wo47 y en menor medida de hornblendas ricas en Mg (magnesio hastingsita, en una matriz holocristalina de textura intergranular. Son rocas subalcalinas de composiciones basalto-andesita y con afinidades calcoalcalinas. La edad Ar/Ar obtenida en una de estas muestras (180,1±1,5 Ma representa la primer determinación realizada en esta unidad y es coherente con las relaciones estratigráficas observadas para esta formación. La comparación con rocas ígneas jurásicas de la provincia geológica Macizo del Deseado, favorece la vinculación temporal y genética con el evento volcánico-piroclástico del Jurásico medio a superior (Formación Bajo Pobre y Grupo Bahía Laura. Sin embargo, la diferencia en las edades Ar/Ar, sugieren una interrupción entre el evento subvolcánico (180 Ma y el volcanismo Jurásico medio a superior (177 a 150 Ma. Se considera, preliminarmente, que los cuerpos subvolcánicos de la Formación Cerro León representarían las primeras evidencias magmáticas del rift jurásico en el Macizo del Deseado.New subvolcanic outcrops, correlated with the Cerro León Formation and located in the eastern Deseado Massif, are presented. This unit outcrops in two sectors, the Leonardo depression and the Bahía Laura outcrop of the Río Deseado Complex. In the first sector there are thirteen dikes and a sill

  13. 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.…

  14. Measured ground-surface movements, Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Massey, B.L.

    1981-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley, 30 kilometers southeast of Mexicali, Baja California, incurred slight deformation because of the extraction of hot water and steam, and probably, active tectonism. During 1977 to 1978, the US Geological Survey established and measured two networks of horizontal control in an effort to define both types of movement. These networks consisted of: (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from stations on an existing US Geological Survey crustal-strain network north of the international border; and (2) a local net tied to stations in the regional net and encompassing the present and planned geothermal production area. Electronic distance measuring instruments were used to measure the distances between stations in both networks in 1978, 1979 and 1981. Lines in the regional net averaged 25 km. in length and the standard deviation of an individual measurement is estimated to be approx. 0.3 part per million of line length. The local network was measured using different instrumentation and techniques. The average line length was about 5 km. and the standard deviation of an individual measurement approached 3 parts per million per line length. Ground-surface movements in the regional net, as measured by both the 1979 and 1981 resurveys, were small and did not exceed the noise level. The 1979 resurvey of the local net showed an apparent movement of 2 to 3 centimeters inward toward the center of the production area. This apparent movement was restricted to the general limits of the production area. The 1981 resurvey of the local net did not show increased movement attributable to fluid extraction.

  15. 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

  16. Rivers and Hughes's Construction of Black Culture in White America——Textual Analysis of "The Negro Speaks of RAvers"

    Institute of Scientific and Technical Information of China (English)

    曾慧

    2009-01-01

    Langston Hughes's central purpose in writing is "to explain and illuminate the Negro condition in America". By means of textual analysis, this thesis is to discover how the images of rivers in "The Negro Speaks of Rivers" construct the black culture, to find Hughes's identity in America.

  17. Filmografía y bibliografía del cine negro americano (1930-1960

    Directory of Open Access Journals (Sweden)

    Dr. José Luis Sánchez Noriega

    1999-01-01

    Full Text Available La actualidad del cine negro queda patente con el éxito de crítica y de público de obras recientes como Casino (Martin Scorsese, 1995, La brigada del sombrero (Lee Tamahori, 1996, Al caer el sol (Robert Benton, 1996 o Donnie Brasco (Mike Newell, 1996. Hace unos meses han aparecido dos libros que se ocupan de este género y ofrecen una selección de un centenar de películas: El cine negro en 100 películas de Antonio Santamarina (Alianza, Madrid, 1999 y Obras maestras del cine negro (Mensajero, Bilbao, 1998, de quien firma estas líneas.

  18. The age and constitution of Cerro Campanario, a mafic stratovolcano in the Andes of Central Chile

    OpenAIRE

    Wes Hildreth; Brad Singer; Estanislao Godoy; Francisco Munizaga

    1998-01-01

    ABSTRACT Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km³ edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and unspiked K-Ar analyses of its lavas.La edad y formación del cerro Campanario, un estratovolcán má...

  19. Informe de nuevas variedades IT-2004: NUEVA VARIEDAD DE TABACO NEGRO CUBANO (Nicotiana tabacum L.

    Directory of Open Access Journals (Sweden)

    E. Espino

    2005-01-01

    Full Text Available La nueva variedad de tabaco negro cubana 'IT-2004' posee un potencial de rendimiento de 2370 kg.ha-1 (700 qq/cab., con 20-22 hojas aprovechables por planta, es altamente resistente al moho azul, la pata prieta y necrosis ambiental y resistente a la sequía. Su calidad organoléptica responde al patrón del tabaco negro cubano, aunque con una fortaleza media, de ligera a medianamente fuerte, lo que permite su utilización como productora de materia prima para la industria cigarrera nacional.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Eolic central Guerrero Negro, BCS, Mexico, performance first year operation; Central eolica Guerrero Negro, BCS, Mexico, resultados del primer ano de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Cadenas Tovar, Roberto; Sanchez Cornejo, Carlos; Lopez Rios, Serafin [Comision Federal de Electricidad, Morelia, Michoacan (Mexico); Ley Romero, Jose R [Comision Federal de Electricidad, Guerrero Negro, Baja California Sur (Mexico)

    2000-07-01

    Comision Federal de Electricidad installed a 600 kW wind turbine in the Guerrero Negro isolated electrical grid to evaluate, under actual operation conditions, the contribution of wind energy in the generation of electricity. This paper describes the performance of the wind turbine in terms of its availability, power curve and electricity produced. The results have been satisfactory, electricity was supplied with a lesser fuel consumption than before. [Spanish] La Comision Federal de Electricidad instalo en Guerrero Negro, Baja California Sur, Mexico un aerogenerador de 600 kW para evaluar en condiciones reales de operacion la integracion de la energia del viento a sistemas electricos aislados basados en diesel. En este trabajo se describen los resultados del primer ano de operacion del aerogenerador en terminos de su disponibilidad, curva de potencia y generacion obtenida. Los resultados han sido satisfactorios, registrandose una reduccion en el consumo de combustible fosil en el sistema.

  2. Corpo negro e cultura brasileira em cinco filmes nacionais: uma leitura de Cidade de Deus, Orfeu Negro, Orfeu, Madame Satã e Ônibus 174

    Directory of Open Access Journals (Sweden)

    Érica Rodrigues Fontes

    2007-01-01

    Full Text Available This paper analyses howCidade de Deus, Orfeu Negro, Orfeu,Ônibus 174 e Madame Satã filter ideologiesthat are connected to thedominant powers and to the culturalhistory of Brazil, portraying the African-brazilian as the Other, source ofsocial violence. For a deeper analysisof how identity is created in themovie, I will make use of PeggyPhelan’s Theory of Identity whichaffirms it is constructed by theglance.

  3. 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)

  4. 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...

  5. 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.)

  6. El Negro, el Niño, witchcraft and the absence of rain in Botswana

    NARCIS (Netherlands)

    Gewald, J.B.

    2001-01-01

    In October 2000, the remains of 'El Negro', a Tswana man who had died 170 years before and who, as a stuffed specimen, had been on display in Europe for over 160 years, were flown from Spain to Botswana and given a State funeral in the capital Gaborone. In early 2001, as it became clear that the rai

  7. Irmã de índio, mulher de branco: perspectivas femininas no alto rio Negro

    Directory of Open Access Journals (Sweden)

    Cristiane Lasmar

    2008-10-01

    Full Text Available A posição "deslocada" das mulheres é um traço constitutivo da experiência social feminina no alto rio Negro, em contraste com a masculina, esta fortemente centrada na noção de "pertencimento". Tomando isso por pressuposto, realiza-se, neste artigo, uma reflexão sobre a experiência social das mulheres indígenas que residem na cidade de São Gabriel da Cachoeira, principal pólo urbano da bacia do alto rio Negro. Com base em análise etnográfica, discute-se o modo como os casamentos com brancos na cidade contribuem para o processo de transformação da experiência social feminina.The "displaced" position of women is a constitutive feature of female social experience in the Upper Rio Negro, in contrast to the male position which is centred on the notion of "belonging". Starting from this premise, the article reflects on the social experience of Indigenous women who live in the city of São Gabriel da Cachoeira, the principal urban centre in the Upper Rio Negro basin. Through ethnographic analysis, it explores how marriages with white men in the city contribute to the process of transforming female social experience.

  8. The Making of the New Negro : Black Authorship, Masculinity, and Sexuality in the Harlem Renaissance

    NARCIS (Netherlands)

    Pochmara, Anna

    2011-01-01

    The Making of the New Negro onderzoekt zwarte mannelijkheid in de periode van de Harlem Renaissance, die lange tijd weinig wetenschappelijke aandacht trok, totdat in de jaren negentig veel geleerden ontdekten hoe complex, belangrijk en boeiend deze tijd was. Anna Pochmara maakt gebruik van Afro-Amer

  9. The Economic Impact of Cystic Echinococcosis in Rio Negro Province, Argentina.

    Science.gov (United States)

    Bingham, Glenda M; Larrieu, Edmundo; Uchiumi, Leonardo; Mercapide, Carlos; Mujica, Guillermo; Del Carpio, Mario; Hererro, Eduardo; Salvitti, Juan Carlos; Norby, Bo; Budke, Christine M

    2016-03-01

    Cystic echinococcosis (CE), a parasitic zoonosis with substantial human health and economic consequences, is highly endemic in Rio Negro Province, Argentina. The objective of this study was to estimate the direct and indirect human and livestock-associated monetary losses attributable to CE, in Rio Negro Province, for the year 2010. Human costs were estimated using data obtained from hospital chart reviews, patient interviews, and government reports. Livestock-associated losses were estimated using data from government reports and scientific publications. Spreadsheet models were developed utilizing Latin Hypercube sampling to account for uncertainty in the input parameters. In 2010, the estimated total cost of CE, in Rio Negro Province, ranged from US$4,234,000 (95% credible interval [CI]: US$2,709,000-US$6,226,000) to US$5,897,000 (95% CI: US$3,452,000-US$9,105,000), with livestock-associated losses representing between 80% and 94% of the total losses, depending on whether non-healthcare-seeking human cases were included and if livestock slaughter values were adjusted to account for underreporting. These estimates suggest that CE is responsible for considerable human and livestock-associated monetary losses in Rio Negro Province. Stakeholders and policymakers can use these data to better allocate public health and agricultural resources for this region. PMID:26787144

  10. Using Portraiture to Shift Paradigms: The New Negro Movement in the Classroom

    Science.gov (United States)

    Hildebrand, Jennifer

    2011-01-01

    In the period from roughly 1915 to 1935, many African Americans undertook an ambitious campaign to remake their image in mainstream (white) American society. This New Negro Movement (NNM)--a term that the author uses purposefully in contradistinction to "Harlem renaissance"--can be studied in the classroom, allowing history teachers to introduce…

  11. Length-weight relationship of fishes from a seagrass meadow in Negros Oriental, Philippines

    OpenAIRE

    Kochzius, M.

    1997-01-01

    The parameters a and b of the length-weight relationship of the form W=aL super(b) were estimated for 13 fish species sampled in a seagrass meadow in Negros Oriental, Philippines. Also, to facilitate conversions, the relationship between total length and standard length for the 13 species is given.

  12. 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

  13. 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

  14. Intelectuais negros e formas de integração nacional

    Directory of Open Access Journals (Sweden)

    Antonio Sérgio Alfredo Guimarães

    2004-04-01

    Full Text Available O AUTOR trata neste artigo de três questões: os diversos modos de integração dos "negros" à sociedade brasileira; a maneira também diversa como se formou a idéia de nação brasileira; e finalmente o papel ativo dos intelectuais "negros" na formação do que entendemos por "democracia racial". O seu argumento é de que foram os intelectuais "negros" os responsáveis pela enorme abrangência e capilaridade da doutrina de "democracia racial" entre nós, que a transformou, durante muito tempo, em importante instrumento de mobilização política dos negros. Tal doutrina incorporou idéias elementares, dispersas ao longo da história brasileira, desenvolvidas principalmente por intelectuais "brancos", como Joaquim Nabuco, Gilberto Freyre ou Arthur Ramos, mas re-trabalhadas e re-significadas por intelectuais negros, independentemente do modo como estes se integraram à sociedade brasileira e do modo como identificaram-se como nacionais.IN THIS article, the author deals with three issues: the various modes of integrating "blacks" into Brazilian society; the likewise diverse manners by which the idea of a Brazilian nation came about; and, finally, the active role of "black" intellectuals in forming what we understand as "racial democracy". He argues that "black" intellectuals were responsible for the comprehensiveness and capillarity of the "racial democracy" doctrine amongst us, which for a long time was an important instrument for the political mobilization for blacks. This doctrine incorporated elementary ideas, dispersed throughout Brazilian history, that had been developed mainly by "white" intellectuals, such as Joaquim Nabuco, Gilberto Freyre and Arthur Ramos, but were later reworked and re-signified by black intellectuals, regardless of how the latter came to be integrated into Brazilian society and how they identified themselves as nationals.

  15. Consumo de morera (Morus alba y sorgo negro forrajero (Sorghum almum en ganado Jersey

    Directory of Open Access Journals (Sweden)

    Carlos Boschini

    2000-01-01

    Full Text Available Se cosecharon ramas de morera de 84 días y forraje de sorgo negro forrajero de 77 días de rebrote. El forraje fue suministrado a seis toretes Jersey con un peso vivo promedio de 337 (±24,27 kg, distribuidos en un diseño de cuadrado latino 3 x 3, repetido. Los tratamientos experimentales fueron: a.- suministro único de morera, b.- 50% de morera y 50% de sorgo negro forrajero en base verde tal como fue cosechada y c.- suministro único de sorgo negro forrajero. Ambos forrajes se ofrecieron a los animales en forma picada (hojas y tallos. La mezcla de morera y sorgo se realizó en partes iguales en base al peso fresco. Cada animal recibió 50 kg/día de forraje verde. La relación promedio de hoja:tallo en la morera fue de 1,3 (±0,39 y de 0,84 (±0,26 en el sorgo negro. Se recolectaron muestras del material ofrecido y rechazado para el análisis de materia seca, proteína cruda, fibra neutro detergente y cenizas totales. No se observaron diferencias (p>0,05 en el consumo de materia fresca y de materia seca (kg/animal/día entre los tratamientos. La ingesta de materia seca por cada 100 kg de peso vivo de los animales fue de 1,94% para la dieta de morera, 1,82% para la mezcla morera/sorgo y 1,67% para la dieta de sorgo negro, lo cual fue inferior al 2% esperado

  16. 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.

  17. Aero radiometric relay of the areas including in the photo map: Sierra de los Rios (C 15), Fraile Muerto (Page E-16) and Cerro de Las Cuentas (Page E- 17) Cerro Largo district

    International Nuclear Information System (INIS)

    The present work constitutes the second part of the report realised on the aerorradimetric relief of the Long Hill Department. 1,325 km of in detail regular prospection were arrived at end on the photo-plans Died Frayle, Hill of Cuentas and Mountain range of the Rivers. This constitutes a 59% of the total of the areas released in all the campaign. A series took place in addition to aircraft reconnaissances on the photo-plans Step Pereira, Cordobes and Cerrezuelo covering 480 km, on the departments of Long Hill and bordering areas of the department of Peach tree. These works took place between days 8 of November to the 8 of December of 1970 being developed in this period, the making a flight, elaboration of the cintilometricos registries and interpretation of the same. The work area includes/understands the flights inclusively number 16 to the 26 and 30 and 31 flights in agreement can be seen in the advance plane. Scale 1:100.000

  18. Epithermal mineralization controlled by synextensional magmatism in the Guazapares Mining District of the Sierra Madre Occidental silicic large igneous province, Mexico

    Science.gov (United States)

    Murray, Bryan P.; Busby, Cathy J.

    2015-03-01

    syndepositional fault and adjacent hanging wall graben fill. (2) The San Antonio resource area, underlain by interstratified mafic-intermediate lavas and fluvial sandstone of the Témoris formation, faulted and tilted by two en echelon NW-trending normal faults with opposing dip-directions. Mineralization occurs along subvertical structures in the accommodation zone between these faults. There are no silicic intrusions at the surface within the San Antonio resource area, but they outcrop ˜0.5 km to the east, where they are intruded along the La Palmera Fault, and are located ˜120 m-depth in the subsurface. (3) The La Unión resource area, which is underlain by mineralized andesite lavas and lapilli-tuffs of the Témoris Formation. Adjacent to the La Unión resource area is Cerro Salitrera, one of the largest silicic intrusions in the area. The plug that forms Cerro Salitrera was intruded along the La Palmera Fault, and was not recognized as an intrusion prior to our work. We show here that epithermal mineralization is Late Oligocene to Miocene-age and hosted in extensional structures, younger than Laramide (Cretaceous-Eocene) ages of mineralization inferred from unpublished mining reports for the region. We further infer that mineralization was directly related to the emplacement of silicic intrusions of the Sierra Guazapares formation, when the mid-Cenozoic ignimbrite flare-up of the Sierra Madre Occidental swept westward into the study area about 24.5-23 Ma ago.

  19. Propuesta didáctica para implementar el concepto de agujero negro en estudiantes de educación media

    OpenAIRE

    Sánchez Ibarra, Jenny Paola

    2012-01-01

    Este trabajo de grado muestra el diseño de un Objeto Virtual de Aprendizaje (OVA) que desarrolla el concepto de agujero negro, a partir de tres interrogantes principales: ¿Qué es y cómo se forma un Agujero Negro? ¿Puede un Agujero Negro comerse toda la materia del universo? y ¿Qué pasaría si caigo en un Agujero Negro?. El OVA se realizó en la Dirección Nacional de Innovación Académica de la Universidad Nacional de Colombia, y es una herramienta dirigida al docente de física, que servirá entre...

  20. Mecanismos de deformación en la transición milonitas/striped gneiss y milonitas/ ultramilonitas en las sierras de Azul, cratón del Río de la Plata, Buenos Aires Deformation mechanisms in the mylonite/striped gneiss and mylonite/ultramylonite transition in Sierras de Azul, Río de la Plata craton, Buenos Aires

    Directory of Open Access Journals (Sweden)

    María C. Frisicale

    2010-08-01

    Full Text Available En el extremo occidental de la megacizalla de Azul se identificaron una serie de rocas miloníticas que presentan un grado de deformación variable e incluyen protomilonitas, milonitas, ribbon mylonites, striped gneisses y ultramilonitas. Se examinaron en forma detallada los mecanismos de deformación actuantes sobre los minerales principales de estas rocas, como feldespatos, cuarzo, anfíboles y piroxenos. El análisis de los mecanismos de deformación permitió realizar una estimación del grado metamórfico alcanzado en este sector de la zona de cizalla. Así se reconocen claramente dos áreas con diferente grado metamórfico, una en la que la deformación se habría producido en facies de anfibolita a granulita (temperaturas superiores a 600° y que se reconoce en los afloramientos del sector norte, cerro Negro y manantiales de Pereda; y una segunda área, que incluye los afloramientos de las estancias La Manuela y La Chiquita, donde la deformación, de menor intensidad, se desarrolló bajo condiciones de facies de esquistos verdes. Asimismo se analizaron los indicadores cinemáticos macro y microscópicos tales como estructuras S-C, granos rígidos fragmentados, porfiroclastos rotados y estructuras del tipo mineral-fish, con la finalidad de determinar el sentido de movimiento de las masas rocosas en esta área particular, y compararlo con los resultados existentes para el resto de la megacizalla de Azul.At the western sector of the Azul Megashear, mylonitic rocks with variable deformation that includes protomylonites, mylonites, ribbon mylonites, striped gneiss and ultramylonites were identified. A detailed examination of deformation mechanisms acting on main minerals like feldspar, quartz, amphibole and pyroxene was done. The analysis of deformation mechanisms allowed to establish the metamorphic degree reached in this sector of the shear zone. Thus, two areas with different metamorphic conditions were recognized. One of them, that involve

  1. Paleoambientes lacustres en la sección inferior de la Formación Río Negro, (Mioceno - Plioceno, Río Negro, Argentina

    Directory of Open Access Journals (Sweden)

    Roberto Schillizzi

    2008-12-01

    Full Text Available Se estudian paleoambientes lacustres aflorantes en un sector de la plataforma marina ubicadas en la localidad de La Lobería, Provincia de Río Negro. Los medios lagunares son buenos indicadores de las modificaciones climáticas soportadas por el ambiente. La metodología aplicada para la investigación consistió en tamizados por vía seca de las psamítas, análisis con difractometría de rayos "X" de las arcillas y observaciones paleontológicas. En la plataforma intermareal se determino la presencia de tres secciones que componen el miembro inferior de la Formación Río Negro. La sección basal esta formada por areniscas finas, gris verdoso, de origen eólico y depositadas en un medio de dunas con influencia ácuea. La sección media esta constituida por limolitas arcillosas a arenosas finas, color pardo rosado, con estratificación, moldes de bivalvos dulceacuícolas e icnitas de vertebrados. Esta sección se asocia a lagunas someras y restringidas, ambiente que se habría extendido en dirección NE. Este nivel esta cubierto por la sección superior formada por areniscas gris azuladas claras, con estratificación cruzada a horizontal, depositadas en un medio eólico. En la actualidad los ambientes lagunares descriptos soportan una fuerte erosión marina.This paper describes pond paleoenvironments from a marine platform sited in La Lobería, Río Negro Province, Argentina. Ponds are good indicators of paleoenvironmental evolution because they are very sensitive to changes in climatic conditions. The methodology used for this research consisted in dry sieving, X-ray diffractometry analysis and paleontological observations. Three sections belonging to the lower section of the Río Negro formation were determined in the intertidal platform. The lower section is composed of fine-grained greenish gray sandstones deposited in an aeolian dune environment with acueos influence. The middle section consists of stratifield pinkish brown clayey to

  2. Case history report on East Mesa and Cerro Prieto geothermal fields

    Energy Technology Data Exchange (ETDEWEB)

    Davis, DG.; Sanyal, S.K.

    1979-06-01

    Well log analysis as applied to the geothermal industry is one of the areas of technology in great need of further development. One means of improving log analysis technology is to study case histories of the past uses of log analysis as applied to specific fields. The project described in this report involved case history studies on two well-known geothermal areas in North America: the East Mesa field in California and the Cerro Prieto field in Mexico. Since there was considerably more pertinent material available on East Mesa, a major part of the effort on this project was devoted to studying the East Mesa field. One particular problem that first came to attention when studying the Cerro Prieto data was the difficulty in determining actual formation temperature at the time of logging. Since the temperature can have a significant effect on well log readings, an accurate temperature determination was considered to be important.

  3. Occurrences of alunite, prophyllite, and clays in the Cerro La Tiza area, Puerto Rico

    Science.gov (United States)

    Hildebrand, Fred Adelbert; Smith, Raymond J.

    1959-01-01

    A deposit of hydrothermally altered rocks in the Cerro La Tiza area located between the towns of Comerio and Aguas Buenas, approximately 25 kilometers southwest of San Juan, Puerto Rico, was mapped and studied to determine the principal minerals, their extent distribution and origin, and the possibility of their economic utilization, especially in Puerto Rico. The Cerro la Tiza area is about 7? kilometers long, has an average width of about 1? kilometers and embraces a total area of approximately 15 square kilometers. The principal mineralized zone, a dike-like mass of light-colored rocks surrounded by dark-colored volcanic country rocks, occupies the crest and upper slopes of east-trending Cerro La Tiza ridge and is believed to be of Late Cretaceous or Eocene age. This zone is approximately 5,300 meters long, 430 meters wide and has an area of approximately 225 hectares (556 acres). The rocks of the mineralized zone are of mixed character and consist mainly of massive quartzose rocks and banded quartz-alunite rocks closely associated with foliated pyrophyllitic, sericitic and clayey rocks. The principal minerals in probably order of abundance are quartz, alunite, pyrophyllite, kaolin group clays (kaolinite and halloysite) and sericite. Minerals of minor abundance are native sulfure, diaspore, svanbergite (?), sunyite (?), hematite, goethite, pyrite, rutile (?) and very small quantities of unidentified minerals. The mineralized zone has broken down to deposits of earth-rock debris of Quaternary age that cover much of the slopes and flanks of Cerro La Tiza. This debris consists generally of fragments and boulders with a very large size range embedded in a clayey matrix. The distribution of the earth-rock debris with respect to the present topography and drainage suggests that it may have undergone at least two cycles of erosion. Underlying the earth-rock debris and completely enclosing the mineralized zone are country rocks of probably Late Cretaceous age. These

  4. H2S and CO2 emissions from Cerro Prieto geothermal power plant, Mexico

    Science.gov (United States)

    Peralta, Oscar; Franco, Luis; Castro, Telma; Taran, Yuri; Bernard, Ruben; Inguaggiato, Salvatore; Navarro, Rafael; Saavedra, Isabel

    2014-05-01

    Cerro Prieto geothermal power plant has an operation capacity of 570 MW distributed in four powerhouses being the largest geothermal plant in Mexico. The geothermal field has 149 production wells. It is located in Cerro Prieto, Baja California, 30 km to the south of the Mexico-US border. Two sampling campaigns were performed in December 2012 and May 2013 where geothermal fluids from 46 production wells and 10 venting stacks were obtained and analyzed by gas chromatography coupled to mass spectrometry. Average CO2 and H2S composition of samples from venting stacks were 49.4% and 4.79%, respectively. Based on the chemical composition of samples, the geothermal power plant emits every day from venting stacks 869 tons of CO2, plus 68 tons of H2S, among other non-condensable gases.

  5. The age and constitution of Cerro Campanario, a mafic stratovolcano in the Andes of central Chile

    Science.gov (United States)

    Hildreth, W.; Singer, B.; Godoy, E.; Munizaga, F.

    1998-01-01

    Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km3 edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and unspiked K-Ar analyses of its lavas.

  6. New mammalian records in the Parque Nacional Cerros de Amotape, northwestern Peru

    OpenAIRE

    Cindy M. Hurtado; Víctor Pacheco

    2015-01-01

    The Pacific Tropical Rainforest and Equatorial Dry Forest are found only in southern Ecuador and northern Peru, and are among the most poorly known ecosystems of South America. Even though these forests are protected in Parque Nacional Cerros de Amotape (PNCA), they are threatened by fragmentation because of farming and agriculture. The aim of this study was to determine the medium and large mammalian species richness, using transect census, camera trapping, and specimen bone collection. Nine...

  7. Study of the atmospheric conditions at Cerro Armazones using astronomical data

    OpenAIRE

    Lakicevic, Masha; Kimeswenger, Stefan; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-01-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Cherenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using line-by-line ...

  8. Outbreak of acute Chagas disease associated with oral transmission in the Rio Negro region, Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Rita de Cássia de Souza-Lima

    2013-10-01

    Full Text Available Introduction Chagas disease is considered as emerging in the Brazilian Amazon, usually occurring in acute outbreaks. Methods We describe 17 cases of acute Chagas disease in Rio Negro, Amazonas. Results There were 15 males (average age, 31.3 years, all positive for Trypanosoma cruzi in fresh blood smear examination, and 14 positive by xenodiagnosis and PCR. The top clinical manifestations were fever, asthenia, abdominal pain, and palpitations. Electrocardiograms featured low-voltage QRS, anterosuperior divisional block, and right bundle branch block associated with anterosuperior divisional block. Conclusions All patients had consumed açaí products from Monte Alegre in the rural area around Santa Izabel do Rio Negro, Brazil.

  9. Outbreak of acute Chagas disease associated with oral transmission in the Rio Negro region, Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Rita de Cassia de Souza-Lima

    2013-07-01

    Full Text Available Introduction Chagas disease is considered as emerging in the Brazilian Amazon, usually occurring in acute outbreaks. Methods We describe 17 cases of acute Chagas disease in Rio Negro, Amazonas. Results There were 15 males (average age, 31.3 years, all positive for Trypanosoma cruzi in fresh blood smear examination, and 14 positive by xenodiagnosis and PCR. The top clinical manifestations were fever, asthenia, abdominal pain, and palpitations. Electrocardiograms featured low-voltage QRS, anterosuperior divisional block, and right bundle branch block associated with anterosuperior divisional block. Conclusions All patients had consumed açaí products from Monte Alegre in the rural area around Santa Izabel do Rio Negro, Brazil.

  10. New species of Cyphocharax (Characiformes: Curimatidae from the upper rio Negro, Amazon basin

    Directory of Open Access Journals (Sweden)

    Bruno F. Melo

    2014-06-01

    Full Text Available A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

  11. [The people of the black waters: the Amazon caboclo of the Negro river].

    Science.gov (United States)

    dos Santos, Fernando Sergio Dumas

    2007-12-01

    The article constructs a historically contextualized description of the people who live along the Negro river, a Brazilian affluent in the Amazon basin. Drawing on information about the daily social experience of the participants from the dawn of the twentieth century through the mid-1990s, the processes by which the population and communities took shape are identified. On the Negro river, contact between Brazilian society and the autochthonous, catechized indigenous groups living there was determinant in shaping the territory's caboclo identity. Starting in the last quarter of the nineteenth century, this nomenclature took root and entered the popular lexicon. Extractivist activities played a major role in spreading the term, within a context where the predominant social relations derived from the 'cultura do barracão'.

  12. Relationship between water chemistry and sediment mineralogy in the Cerro Prieto geothermal field: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Valette-Silver, J.N. (Univ. de Perpignan, France); Thompson, J.M.; Ball, J.W.

    1981-01-01

    The chemical compositions of waters collected from the Cerro Prieto geothermal production wells and hydrothermal emanations are different. Compared to the Cerro Prieto well waters, the surficial waters generally contain significantly less potassium, slightly less calcium and chloride, and significantly more magnesium and sulfate. In comparison to the unaltered sediments, the changes in the mineralogy of the altered sediments appear to be controlled by the type of emanation (well, spring, mud pot, geyser, fumarole, or cold pool). However, an increase in quartz and potassium feldspar percentages seems to be characteristic of the majority of the sediments in contact with geothermal fluids. Preliminary attempts to model the chemical processes occurring in the Cerro Prieto geothermal field using chemical equilibrium calculations are reported. For this purpose the chemical compositions of thermal waters (well and surficial emanation) were used as input data to make calculations with SOLMNEQ and WATEQ2 computer programs. Then the theoretical mineral composition of altered sediments was predicted and compared to the mineralogy actually observed in the solid samples.

  13. Evolution of the Cerro Prieto geothermal system as interpreted from vitrinite reflectance under isothermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barker, C.E. (US Geological Survey, Denver, CO); Pawlewicz, M.J.; Bostick, N.H.; Elders, W.A.

    1981-01-01

    Temperature estimates from reflectance data in the Cerro Prieto system correlate with modern temperature logs and temperature estimates from fluid inclusion and oxygen isotope geothermometry indicating that the temperature in the central portion of the Cerro Prieto System is now at its historical maximum. Isoreflectance lines formed by contouring vitrinite reflectance data for a given isothermal surface define an imaginary surface that indicates an apparent duration of heating in the system. The 250/sup 0/C isothermal surface has a complex dome-like form suggesting a localized heat source that has caused shallow heating in the central portion of this system. Isoreflectance lines relative to this 250/sup 0/C isothermal surface define a zone of low reflectance roughly corresponding to the crest of the isothermal surface. Comparison of these two surfaces suggest that the shallow heating in the central portion of Cerro Prieto is young relative to the heating (to 250/sup 0/C) on the system margins. Laboratory and theoretical models of hydrothermal convection cells suggest that the form of the observed 250/sup 0/C isothermal surface and the reflectance surface derived relative to it results from the convective rise of thermal fluids under the influence of a regional hydrodynamic gradient that induces a shift of the hydrothermal heating effects to the southwest.

  14. A review of the hydrogeologic-geochemical model for Cerro Prieto

    Science.gov (United States)

    Lippmann, M.J.; Truesdell, A.H.; Halfman-Dooley, S. E.; Mañónm, A.

    1991-01-01

    With continued exploitation of the Cerro Prieto, Mexico, geothermal field, there is increasing evidence that the hydrogeologic model developed by Halfman and co-workers presents the basic features controlling the movement of geothermal fluids in the system. In mid-1987 the total installed capacity at Cerro Prieto reached 620 MWc, requiring a large rate of fluid production (more than 10,500 tonnes/hr of a brine-steam mixture; August 1988). This significant mass extraction has led to changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. Pressure drawdown has caused an increase in cold water recharge in the southern and western edges of the field, and local and general reservoir boiling in parts of the geothermal system. After reviewing the hydrogeologic and geochemical models of Cerro Prieto, the exploitation-induced cold water recharge and reservoir boiling (and plugging) observed in different areas of the field, are discussed and interpreted on the basis of these models and schematic flow models that describe the hydrogeology. ?? 1991.

  15. TOTAL MERCURY (HgT) BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    OpenAIRE

    Jean Louchard Ferreira Soares; Ynglea Georgina de Freitas Goch; José Reinaldo Pacheco Peleja; Bruce Rider Forsberg; Edivaldo Júnior de Souza Lemos; Otávio Peleja de Sousa

    2016-01-01

    In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg) in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were d...

  16. "I Seem To Be Thinking Of Africa All The Time": Nancy Cunard's Negro: An Anthology

    OpenAIRE

    Griffin, Thabisile Inaya Nurah

    2014-01-01

    The appearance of Nancy Cunard's 1934 massive Negro: An Anthology represented a significant rupture in the literary and socio-political worlds of the interwar era. This collection of over 150 Black voices from around the world, along with a few notable white contributors, symbolized an important breach in Black radical literature at that time. Describing her work as a "brief outline of the history of the black race,"1 Cunard emphasized her personal desire to counter what she believed to be th...

  17. Santos negros nas Américas na crise do Antigo Regime

    Directory of Open Access Journals (Sweden)

    Caroline dos Santos Guedes

    2014-12-01

    Full Text Available Os objetos de estudo deste ensaio são a irmandade de São Baltasar em Buenos Aires e a irmandade de São Elesbão e Santa Efigênia no Rio de Janeiro de fins do século XVIII até princípios do século XIX. Ambas as instituições têm majoritariamente associados negros e contam também com santos negros como patronos. Observe-se a importância da apropriação da religião católica por estes afrodescendentes e o papel que esses “santos de cor” exercem no cotidiano desta população restrita de direitos devido à sua ascendência africana. As irmandades são instituições de suma importância na dinâmica colonial, então os negros se inserem nessas instituições ou criam suas próprias, muitas vezes na tentativa de penetrar no mundo social das colônias, ganhando maior visibilidade.

  18. OSL dating of sediments from Negro and Solimões rivers – Amazon, Brazil

    International Nuclear Information System (INIS)

    In this work, the OSL dating results of Quaternary fluvial deposits from the confluence of Negro and Solimões rivers were studied. The equivalent doses (De) of sediments were obtained using a Single Aliquot Regeneration (SAR) protocol. Statistic studies were made using frequency histogram, weighted histogram and Radial plot in order to analyze the De fluctuations. Ages from 74.5 to 205 thousand of years (Pleistocene) were recorded. The gamma-ray spectroscopy was used to evaluate the natural radioisotopes concentrations of the samples and low concentrations were found with values between 0.64 and 3.71 ppm for 235U and 238U; 2.01–9.77 ppm for 232Th; already, for 40K, the concentration was negligible. The OSL dating of sediments has contributed to a better understanding of the evolution of Negro and Solimões rivers, in Amazon, Brazil. - Highlights: ► OSL dating of fluvial terraces from Amazon. ► SAR protocols applied to Amazon sediments dating. ► OSL dating of Solimão and Negro rivers sediments

  19. Actualization of the Hydrogeological Model of the Ojos Negros VALLEY\\'{ }s Aquifer

    Science.gov (United States)

    Campos-Gaytan, J.; Vazquez Gonzalez, R.

    2002-12-01

    A regional groundwater flow model is actualized in order to study the water table behavior in the zone of the Ojos Negros valley, which is located in the state of Baja California, Mexico. In the actualization process of the Ojos Negros valley's hydrogeological model, is used all the information proportionate for the National Commission of Water, as well as that information obtained from academic and research works achieved in the study zone, about the hydrogeological conditions that present the Ojos Negros and Real del Castillo aquifers. In addition, a groundwater flow simulator is modified and improved from the numerical point of view. The actualized simulator solves numerically the Boussinesq equation, using centrals finite-differences techniques, the "fully implicit" approximation for the temporary variation, and the iterative method of successive over relaxation. Also it counts with the structure to considering the temporary variation of the different variables and geohydrologics conditions that has influence upon the groundwater system, and with programming subroutines in MATLAB (2000) for the graphic display of results. The simulation results are appropriate for determining the phreatic surface and the flow directions in different time intervals. The phreatic surface information can be used for studying the behavior (temporary evolution) of water table in the aquifers.

  20. Metazoan endoparasites of Serrasalmus marginatus (Characiformes: Serrasalminae in the Negro River, Pantanal, Brazil Metazoários endoparasitos de Serrasalmus marginatus (Characiformes: Serrasalminae no Rio Negro, Pantanal, Brasil

    Directory of Open Access Journals (Sweden)

    Wagner Vicentin

    2011-03-01

    Full Text Available In order to inventory the metazoan endoparasites of Serrasalmus marginatus, 91 specimens were examined. They were captured in the Negro River in Pantanal wetland, State of Mato Grosso do Sul, Central-Western Brazil, from October 2007 to August 2008. Parasites of six taxa were recovered: Procamallanus (Spirocamallanus inopinatus, Contracaecum sp. (Nematoda, metacercarial type Diplostomulum (Digenea, Brevimulticaecum sp. (Nematoda and Sebekia oxycephala, Subtriquetra sp. 1 and Subtriquetra sp. 2 (Pentastomida. The latter five species are reported for the first time in S. marginatus.Com o objetivo de inventariar os metazoários endoparasitos em Serrasalmus marginatus, no Rio Negro, Pantanal, Mato Grosso do Sul, Brasil, foram examinados 91 espécimes capturados no período de outubro de 2007 a agosto de 2008. Foram registrados seis táxons parasitos: Procamallanus (Spirocamallanus inopinatus, Contracaecum sp. (Nematoda, metacercária do tipo Diplostomulum (Digenea; Brevimulticaecum sp. (Nematoda; e Sebekia oxycephala, Subtriquetra sp. 1 e Subtriquetra sp. 2 (Pentastomida. As últimas cinco espécies citadas são registradas pela primeira vez em S. marginatus.

  1. Burn Severities, Fire Intensities, and Impacts to Major Vegation Types from the Cerro Grande Fire

    International Nuclear Information System (INIS)

    The Cerro Grande Fire resulted in major impacts and changes to the ecosystems that were burned. To partially document these effects, we estimated the acreage of major vegetation types that were burned at selected burn severity levels and fire intensity levels. To accomplish this, we adopted independently developed burn severity and fire intensity maps, in combination with a land cover map developed for habitat management purposes, as a basis for the analysis. To provide a measure of confidence in the acreage estimates, the accuracies of these maps were also assessed. In addition, two other maps of comparable quality were assessed for accuracy: one that was developed for mapping fuel risk and a second map that resulted from a preliminary application of an evolutionary computation software system, called GENIE. According to the burn severity map and the fire intensity map, the Cerro Grande Fire is estimated to have covered 42,885.4 acres and 42,854.7 acres, respectively. Of this, 57.0 percent was burned at low severity and 34.7 percent was burned at high severity. Similarly, 40.0 percent of the Cerro Grande Fire burned at high fire intensity, greater than 70 percent mortality, while 33.1 percent burned at moderately low intensity, 10 to 40 percent mortality. The most frequently burned cover types over the entire Cerro Grande Fire were ponderosa pine forest and mixed conifer forest, at approximately 43 percent each. However, portions of the fire that burned on Los Alamos National Laboratory (LANL) property were predominantly in ponderosa pine forests, whereas the Cerro Grande Fire burned primarily in mixed conifer forests on lands managed by other agencies. Some of the polygons of burn severities and fire intensities were extensive. The two largest burn severity polygons were 10,111 acres and 10,903 acres and these were burned at low severity. The next two largest polygons were 8999 acres (14 square miles) and 1551 acres (2.4 square miles) and both of these polygons

  2. Edad y rasgos petrográficos y geoquímicos de cuerpos subvolcánicos asignables a la Formación Cerro León, este del Macizo del Deseado, Santa Cruz

    Directory of Open Access Journals (Sweden)

    D. Guido

    2004-12-01

    Full Text Available Se presentan nuevos afloramientos de cuerpos subvolcánicos correlacionables con la Formación Cerro León en el sector oriental del Macizo del Deseado. Esta unidad aflora en dos sectores, en el bajo Leonardo y en el afloramiento Bahía Laura del Complejo Río Deseado. El primer sector presenta trece diques y un filón capa intruyendo a las sedimentitas pérmicas de la Formación La Golondrina y el segundo sector comprende tres diques que intruyen a rocas del basamento. Se trata de rocas de color gris a negro, frecuentemente alteradas, con textura microgranuda a porfírica, con fenocristales de plagioclasa, diópsido (En42 Fs11 Wo47 y en menor medida de hornblendas ricas en Mg (magnesio hastingsita, en una matriz holocristalina de textura intergranular. Son rocas subalcalinas de composiciones basalto-andesita y con afinidades calcoalcalinas. La edad Ar/Ar obtenida en una de estas muestras (180,1±1,5 Ma representa la primer determinación realizada en esta unidad y es coherente con las relaciones estratigráficas observadas para esta formación. La comparación con rocas ígneas jurásicas de la provincia geológica Macizo del Deseado, favorece la vinculación temporal y genética con el evento volcánico-piroclástico del Jurásico medio a superior (Formación Bajo Pobre y Grupo Bahía Laura. Sin embargo, la diferencia en las edades Ar/Ar, sugieren una interrupción entre el evento subvolcánico (180 Ma y el volcanismo Jurásico medio a superior (177 a 150 Ma. Se considera, preliminarmente, que los cuerpos subvolcánicos de la Formación Cerro León representarían las primeras evidencias magmáticas del rift jurásico en el Macizo del Deseado.

  3. Dynamics of Dissolved Organic Matter in Amazon Basin: Insights into Negro River Contribution

    Science.gov (United States)

    Moreira-Turcq, P.; Perez, M. P.; Benedetti, M.; Oliveira, M. A.; Lagane, C.; Seyler, P.; Oliveira, E.

    2006-12-01

    The study of global carbon cycle requires a precise knowledge of spatial and temporal distributions and exportation from continents to oceans. Organic carbon fluxes represent approximately half of the total carbon budget carried by rivers. Tropical rivers transport two third of the total organic carbon discharged into the world oceans but important gaps still exist in the knowledge of the tropical river carbon biochemistry. The Amazon River is responsible for 10% of the annual amount of organic carbon transported from rivers to oceans. The most important portion of total organic matter transported in the Amazon Basin is the dissolved fraction (between 80% and 95%). Amazonian annual flux of dissolved organic matter is directly related to hydrological variations. All rivers in the Amazon basin are characterized by monomodal hydrograms, with a low water period in october/november and a high water period in may/june. Temporal variations in Amazon dissolved organic carbon (3.0 to 9.1 mg l^{- 1}) are mainly controled by Negro River inputs. DOC and DON contributions from the Negro River can vary between 120 kgC s-1 and 520 kg C s-1, and between 5 kgN s--1 and 15 kgN s-1, during low and high water period, respectivelly. In the Negro River, during high water stages, while DOC concentrations are stable from the upstream stations to the downstream ones (about 11 mg l-1), discharge increases from 16000 to 46000 m3 s-1 and NOD can quintuple from upstream (0.071 mg l-1) to downstream (0.341 mg l-1). Then the nature of dissolved organic matter is variable (C/N ratio varied from 33 to 120 from upstream to downstream). During low water stages DOC concentrations are lower (mean DOC of 8.1 mg l-1) while DON is in the same range, discharge is about 10000 m3 s-1 at downstream stations of Negro River and the C/N ratio is lower and steadier along the River. Finaly, despite a low basin surface (12%) compared with the two other main Amazon tributaries, Solimões and Madeira Rivers, and a

  4. 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

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. 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...

  10. 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.

  11. Geoquímica y mineralogía de un depósito de caolín del área de los menucos, provincia de Río negro

    Directory of Open Access Journals (Sweden)

    Laura Grecco

    2014-06-01

    Full Text Available El área mineralizada Blancón está ubicada a unos 9 km de la localidad de Los Menucos, provincia de Río Negro. El yacimiento de caolín está emplazado en una toba riolítica de la Formación Sierra Colorada de edad triásica media - jurásica media. Se realizaron estudios petrográficos sobre secciones delgadas y análisis químicos de elementos mayoritarios, minoritarios y traza sobre roca total. Además se analizaron las venillas de caolín utilizando MEB, DRX, ATG-TG, IR y análisis isotópicos δ18O y δD. La presencia de pirofilita y alunita, el elevado contenido de Ba y Sr, la distribución de los elementos de las tierras raras y los valores δ18O y δD, permiten concluir que el caolín se formó por alteración hidrotermal de las tobas riolíticas.

  12. Areas to explore surrounding the Cerro Prieto geothermal field, BC; Areas para exploracion en los alrededores del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Dumas, Alvaro [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: alvaro.aguilar@cfe.gob.mx

    2009-07-15

    Exploration plays an important role in tapping underground natural resources-whether water, oil, natural gas or minerals. Exploratory data allow us to learn reservoir conditions, increasing probable reserves and reservoir life span. Around the Cerro Prieto geothermal field, BC, and in the Mexicali Valley in general, exploration had almost stopped but recently was resumed by the Studies Division of Comision Federal de ELectricidad (CFE)'s Gerencia de Proyectos Geotermoelectricos. The division sent technical personnel to structurally map the northern and eastern portions of Laguna Salada. The paper offers a general outline of the main zones undergoing exploratory studies-studies perhaps culminating in siting exploratory wells to locate more geothermal resources (and ultimately producing them using binary power plants). CFE also wants to site injection wells west of the current production zone, and this is covered, as well. All activities are meant to increase the productive lifespan of the geothermal reservoir. [Spanish] Cuando se trata de la explotacion de recursos naturales del subsuelo, sea agua, gas, petroleo o minerales, la exploracion juega un papel muy importante, ya que permite conocer las condiciones del yacimiento que pudieran llevar a incrementar las reservas de los recursos explotados y extender su vida util. En las zonas aledanas al campo geotermico de Cerro Prieto, BC, y en general en el Valle de Mexicali, la exploracion estaba practicamente detenida habiendose reactivado a raiz de que la Subgerencia de Estudios de la Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad (CFE) envio personal para realizar mapeos estructurales en las porciones norte y oriente de la Laguna Salada. Este trabajo presenta un panorama general de las areas prioritarias para realizar estudios exploratorios y poder programar, con mas bases, pozos exploratorios enfocados a localizar mas recursos geotermicos, inclusive para generar energia por medio

  13. Basic aspects of the Cerro Prieto reservoir water recharge; Aspectos basicos de la recarga de agua al reservorio de Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    The Cerro Prieto geothermal field, located 30 km South of Mexicali City, Baja California, has at present an installed capacity of 620 MW in geothermal power plants, that operating with endogenous steam, make use of the underground energy by means of deep wells, from which about 80 million cubic meters per year of high enthalpy water and steam mixture are extracted. During the exploitation physical an chemical changes in the hydrothermal fluids discharged by the wells have been detected, which shows, among other things, an elevated water recharge, located towards the West area of the field and a low recharge in the part of the east zone area. For this reason the hot brine waste re-injection is recommended, (previously treated to eliminate the silica excess) to thermally an hydraulically recharge the reservoir in that part of the field. [Espanol] El campo geotermico de Cerro Prieto, situado a 30 km al sur de la ciudad de Mexicali, Baja California, cuenta actualmente, despues de 18 anos en explotacion, con 620 MW de capacidad instalada en plantas geotermoelectricas que, operando con vapor endogeno, aprovechan la energia del subsuelo mediante pozos profundos de los que se extraen alrededor de 80 millones de metros cubicos por ano de una mezcla de agua vapor de elevada entalpia. Durante la explotacion se han percibido cambios fisicos y quimicos en los fluidos hidrotermales descargados por los pozos, lo que indica, entre otras cosas, una recarga elevada de agua localizada hacia el poniente del campo y una recarga baja en una zona de la parte oriental. Por ello se recomienda la reinyeccion de salmuera geotermica caliente de desecho (previamente tratada para eliminar el exceso de silice) para recargar termica e hidraulicamente el reservorio en esa parte del campo.

  14. Reconnaissance study of late quaternary faulting along cerro GoDen fault zone, western Puerto Rico

    Science.gov (United States)

    Mann, P.; Prentice, C.S.; Hippolyte, J.-C.; Grindlay, N.R.; Abrams, L.J.; Lao-Davila, D.

    2005-01-01

    The Cerro GoDen fault zone is associated with a curvilinear, continuous, and prominent topographic lineament in western Puerto Rico. The fault varies in strike from northwest to west. In its westernmost section, the fault is ???500 m south of an abrupt, curvilinear mountain front separating the 270- to 361-m-high La CaDena De San Francisco range from the Rio A??asco alluvial valley. The Quaternary fault of the A??asco Valley is in alignment with the bedrock fault mapped by D. McIntyre (1971) in the Central La Plata quadrangle sheet east of A??asco Valley. Previous workers have postulated that the Cerro GoDen fault zone continues southeast from the A??asco Valley and merges with the Great Southern Puerto Rico fault zone of south-central Puerto Rico. West of the A??asco Valley, the fault continues offshore into the Mona Passage (Caribbean Sea) where it is characterized by offsets of seafloor sediments estimated to be of late Quaternary age. Using both 1:18,500 scale air photographs taken in 1936 and 1:40,000 scale photographs taken by the U.S. Department of Agriculture in 1986, we iDentified geomorphic features suggestive of Quaternary fault movement in the A??asco Valley, including aligned and Deflected drainages, apparently offset terrace risers, and mountain-facing scarps. Many of these features suggest right-lateral displacement. Mapping of Paleogene bedrock units in the uplifted La CaDena range adjacent to the Cerro GoDen fault zone reveals the main tectonic events that have culminated in late Quaternary normal-oblique displacement across the Cerro GoDen fault. Cretaceous to Eocene rocks of the La CaDena range exhibit large folds with wavelengths of several kms. The orientation of folds and analysis of fault striations within the folds indicate that the folds formed by northeast-southwest shorTening in present-day geographic coordinates. The age of Deformation is well constrained as late Eocene-early Oligocene by an angular unconformity separating folDed, Deep

  15. Hydraulic model and steam flow numerical simulation of the Cerro Prieto geothermal field, Mexico, pipeline network

    International Nuclear Information System (INIS)

    The development of a hydraulic model and numerical simulation results of the Cerro Prieto geothermal field (CPGF) steam pipeline network are presented. Cerro Prieto is the largest water-dominant geothermal field in the world and its transportation network has 162 producing wells, connected through a network of pipelines that feeds 13 power-generating plants with an installed capacity of 720 MWe. The network is about 125 km long and has parallel high- and low-pressure networks. Prior to this study, it was suspected that steam flow stagnated or reversed from its planned direction in some segments of the network. Yet, the network complexity and extension complicated the analysis of steam transport for adequate delivery to the power plants. Thus, a hydraulic model of the steam transportation system was developed and implemented numerically using an existing simulator, which allowed the overall analysis of the network in order to quantify the pressure and energy losses as well as the steam flow direction in every part of the network. Numerical results of the high-pressure network were obtained which show that the mean relative differences between measured and simulated pressures and flowrates are less than 10%, which is considered satisfactory. Analysis of results led to the detection of areas of opportunity and to the recommendation of changes for improving steam transport. A main contribution of the present work is having simulated satisfactorily the longest (to our knowledge), and probably the most complex, steam pipeline network in the world. - Highlights: • Extensive literature review of flow models of geothermal steam gathering networks. • Hydraulic model of the Cerro Prieto geothermal field steam network. • Selection and validation of the employed pressure-drop model. • Numerical flow simulation of the world's largest geothermal steam gathering network. • Detailed network pressure drop analysis and mapping of steam flow distribution

  16. Archaeological fieldwork in the Bronze Age site of Cerro de la Encina (Monachil, Granada

    Directory of Open Access Journals (Sweden)

    Aranda Jiménez, Gonzalo

    2005-06-01

    Full Text Available New archaeological fieldwork has been carried out from November 2003 to May 2004 in the Bronze Age site of Cerro de la Encina, due to the interest of the regional government of Andalusia in displaying the settlement for visitors. The aim of this fieldwork has been the systematic excavation of a large settlement area partially known thanks to the excavations developed at the beginning of 1980s. A first toccupation period belonging to the Argaric Culture has been documented, highlighting specially the funerary ritual characterized by individual inhumations located below dwellings. After a gap in the occupation of the settlement a new social group belonging to the Late Bronze Age Culture of Southeast of Spain inhabits the Cerro de la Encina.

    El interés de la Consejería de Cultura de la Junta de Andalucía por la musealización del yacimiento del Cerro de la Encina ha motivado el desarrollo de nuevas investigaciones arqueológicas cuya primera fase se ha desarrollado entre Noviembre de 2003 y Mayo de 2004. Los trabajos han consistido en la excavación sistemática de un área de poblado de grandes dimensiones parcialmente conocida por las investigaciones realizadas a principios de los años 80. Los resultados han sido del máximo interés documentándose un primer momento de ocupación perteneciente a la Cultura de El Argar en el que destaca su espectacular registro funerario integrado dentro de las áreas de habitación. Tras un periodo de abandono del yacimiento se produce una nueva ocupación correspondiente a una comunidad del Bronce Final del Sureste.

  17. Negro Comapa, nueva variedad de frijol para el estado de Veracruz Negro Comapa, a new bean variety for the State of Veracruz

    Directory of Open Access Journals (Sweden)

    Ernesto López Salinas

    2010-12-01

    Full Text Available El programa de frijol del Campo Experimental Cotaxtla, perteneciente al Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP, ubicado en el municipio de Medellín de Bravo, Veracruz; durante varios años se han realizado trabajos de investigación en mejoramiento genético orientados a la generación de nuevas variedades de frijol negro, opaco y pequeño. Actualmente, Chiapas, Nayarit, Oaxaca y Veracruz son las principales entidades productoras de frijol Negro Comapa, en las cuales durante 2008 se sembraron 256 099 hectáreas, principalmente en otoño-invierno con humedad residual, que corresponde a 15.7% de la superficie sembrada en el país. En Veracruz en ese año se sembraron 42 593 hectáreas de frijol, cuyo rendimiento promedio fue de 730 kilogramos por hectárea.During several years in the bean program at Experimental Field Cotaxtla belonging to National Research Forestry, Agriculture and Livestock Institute (INIFAP, located in the municipality of Medellín de Bravo, Veracruz, research works have been carried out in genetic improvement with the aim of generation of new varieties of small opaque black bean. Currently, Chiapas, Nayarit, Oaxaca and Veracruz are the main producers states of this commercial grain type, in which 256 099 hectares were sowed during 2008, mainly in autumn-winter with residual humidity that corresponds to 15.7% of sowed surface in the country. In Veracruz in that year 42 593 hectares of bean were sowed whose average yield was of 730 kilograms per hectare.

  18. Estratigrafía y análisis tafonómico de Bonitasaura salgadoi Apesteguía, en el sitio «La Bonita» (Cretácico superior, Río Negro, Argentina Stratigraphic and taphonomic analysis of Bonitasaura salgadoi Apesteguía (Sauropoda, Titanosauria at «La Bonita» site (Upper Cretaceous, Río Negro Province, Argentina

    Directory of Open Access Journals (Sweden)

    Leandro M. Pérez

    2009-06-01

    Full Text Available La localidad fosilífera «La Bonita» se ubica en las cercanías del pueblo de Cerro Policía, provincia de Río negro, Argentina. Allí afloran sedimentos continentales silicoclásticos pertenecientes a las Formaciones Bajo de la Carpa y Anacleto (Santoniano-Campaniano separadas en discordancia de la Formación Rentería (Plioceno Superior-Pleistoceno. La Formación Bajo de la Carpa se compone de areniscas, finos bancos conglomerádicos alternados con pelitas y capas de vaques. La Formación Anacleto está compuesta de capas arenopelíticas. La Formación Rentería está mayormente compuesta por conglomerados con clastos que alcanzan 15 cm de longitud, incluídos en una matriz sabulítica. El análisis de facies sugiere un regimen fluvial, con un control subacuático que oscila entre energía media y alta. Los canales arenosos, lenticulares, poseen estratificación entrecruzada indicando un agente de transporte unidireccional. El análisis tafonómico indicaría que el dinosaurio murió en las cercanías de los márgenes del río, siendo rápidamente incorporado a los sedimentos fluviales y sepultado en sucesivos eventos. La distribución especial de los huesos revela un corto transporte desde la fuente de aporte, con una leve orientación hacia el norte. La presencia de dos series de vertebras caudales con arqueamiento opistótono indican que el animal fue expuesto un período suficiente de tiempo para que actúe el rigor mortis y la disecasión. El grado de desarticulación sugiere, también, cierta exposición subaérea, aunque no en gran medida, debido a la exquisita preservación del hueso periostial.«La Bonita» is a fossiliferous locality close to the town of Cerro Policía, Río Negro Province, Argentina. At the quarry are exposed siliceous rocks belonging to the Bajo de la Carpa and Anacleto formations (Santonian-Campanian, separated by an unconformity from the Rentería Formation (Upper Pliocene-Pleistocene. The Bajo de la Carpa

  19. Preliminary plasma spectrometric analyses for selected elements in some geothermal waters from Cerro Prieto, Mexico

    Science.gov (United States)

    Ball, J.W.; Jenne, E.A.

    1983-01-01

    As part of a cooperative study with Dr. Alfred Truesdell, water samples collected from geothermal power production wells at Cerro Prieto, Mexico, were analyzed for selected elements by d.c. argon plasma emission spectroscopy. Spectral interferences due to the presence of high concentrations of Ca, Si, Na and K in these water affected the apparent concentration values obtained. These effects were evaluated and correction techniques were developed and applied to the analytical values. Precipitates present in the samples at the time of analysis adversely affected the accuracy, precision and interpretability of the data. (USGS)

  20. Two-dimensional modeling of apparent resistivity pseudosections in the Cerro Prieto region

    Energy Technology Data Exchange (ETDEWEB)

    Vega, R.; Martinez, M.

    1981-01-01

    Using a finite-difference program (Dey, 1976) for two-dimensional modeling of apparent resistivity pseudosections obtained by different measuring arrays, four apparent resistivity pseudosections obtained at Cerro Prieto with a Schlumberger array by CFE personnel were modeled (Razo, 1978). Using geologic (Puente and de la Pena, 1978) and lithologic (Diaz, et al., 1981) data from the geothermal region, models were obtained which show clearly that, for the actual resistivity present in the zone, the information contained in the measured pseudosections is primarily due to the near-surface structure and does not show either the presence of the geothermal reservoir or the granitic basement which underlies it.

  1. 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

  2. Seroprevalence of Leptospira spp in cattle from Monte Negro municipality, western Amazon Prevalência de anticorpos anti-Leptospira spp em bovinos do município de Monte Negro, Amazônia Ocidental

    OpenAIRE

    Daniel M. Aguiar; Gennari, Solange M.; Guacyara T. Cavalcante; Marcelo B Labruna; Silvio A . Vasconcellos; Aline A. R. Rodrigues; Zenaide M. de Moraes; Luis M.A. Camargo

    2006-01-01

    The prevalence of anti-Leptospira spp antibodies was investigated in 2,109 female cattle from 86 herds of Monte Negro municipality, Rondônia, Brazil. Sera samples were evaluated by Microscopic Agglutination Test against 24 leptospira serovars. Titers =100 for at least one of 24 leptospira serovars were detected in 1,114 cows (52.8%) from 82 (95.3%) herds. The adjusted overall prevalence for Monte Negro municipality was 53.9% (49-58.7%; CI: 95%). The most prevalent serovars were Hardjo (14.5%)...

  3. Dental caries profile in Monte Negro, Amazonian state of Rondônia, Brazil, in 2008

    Directory of Open Access Journals (Sweden)

    Roosevelt Silva Bastos

    2010-10-01

    Full Text Available OBJECTIVE: This epidemiological survey assessed the dental caries profile in Monte Negro, a small town in the Amazonian state of Rondônia, Brazil, and its relationship with the northern region, national and global goals for oral health in the years 2000 and 2020. MATERIAL AND METHODS: The groups randomly examined were composed of individuals aged 5, 12, 15 to 19, 35 to 44, 65 to 74 years, living in both rural and urban areas. RESULTS: The means dft (standard deviation and DMFT (standard deviation for the groups were, respectively, 3.15 (3.12, 3.41 (2.69, 5.96 (4.19, 16.00 (7.30 and 25.96 (9.82. Caries-free individuals were 34.42%, 14.81% and 8.16% in the preschoolchildren, schoolchildren and adolescent groups, respectively. The Significant Caries Index percentages applied to the two younger groups were 6.65 and 6.70, and they increased to 32.00 in the individuals aged 65 to 74 years. Care Index percentages for adolescents, adults and elderly groups were, respectively, 29.40, 25.00 and 1.41. The dental caries profile in Monte Negro in 2008 shows that, 8 years after the year 2000, no FDI/WHO goal for any age settled in 1982 has been achieved. Dental caries increased with age and the main dental problem of adult and elderly groups was tooth loss. CONCLUSION: Oral health promotion and prevention of oral disease policies are urgent needs. Setting of oral health goals and targets to people living in Monte Negro or Amazonia to be pursuit and achieved in a near future is an important action to do because of the culture, sanitary conditions and socioeconomic aspects of this particular population.

  4. El impacto de la crisis fiscal en el trabajo en negro: las provincias de noroeste argentino

    Directory of Open Access Journals (Sweden)

    Marta Panaia

    2000-12-01

    Full Text Available El trabajo se enmarca dentro de los estudios de génesis, crecimiento y dinamismo del sector informal y aumento o disminución de la propensión a trabajar en condiciones de informalidad, ya sea por la forma de contrato (precariedad; por la falta de pago (evasión previsional o comunmente llamado «en gris» o « en negro» por su característica de clandestinidad (ilegalidad o por realizarse en unidades económicas informales. En el contexto económico de la década del '90, en la Argentina, con las nuevas medidas que construyen un nuevo perfil del mercado de trabajo, se analizan los determinantes del mercado de trabajo sin aportes utilizando los datos de la construcción de un mapa de propensión al trabajo en negro, en base a un método de análisis de inobservables de fenómenos de multiples causas y múltiples consecuencias. El mapa construido para todo el país, en una investigación anterior, sirve de base para un análisis más profundo de la zona del Noroeste Argentino, una de las regiones más desfavorecidas del país y donde la propensión al aumento del trabajo en negro es más intensa, contrastándolo con los del total del país.

  5. Viruses Surveillance Under Different Season Scenarios of the Negro River Basin, Amazonia, Brazil.

    Science.gov (United States)

    Vieira, Carmen Baur; de Abreu Corrêa, Adriana; de Jesus, Michele Silva; Luz, Sérgio Luiz Bessa; Wyn-Jones, Peter; Kay, David; Vargha, Marta; Miagostovich, Marize Pereira

    2016-03-01

    The Negro River is located in the Amazon basin, the largest hydrological catchment in the world. Its water is used for drinking, domestic activities, recreation and transportation and water quality is significantly affected by anthropogenic impacts. The goals of this study were to determine the presence and concentrations of the main viral etiological agents of acute gastroenteritis, such as group A rotavirus (RVA) and genogroup II norovirus (NoV GII), and to assess the use of human adenovirus (HAdV) and JC polyomavirus (JCPyV) as viral indicators of human faecal contamination in the aquatic environment of Manaus under different hydrological scenarios. Water samples were collected along Negro River and in small streams known as igarapés. Viruses were concentrated by an organic flocculation method and detected by quantitative PCR. From 272 samples analysed, HAdV was detected in 91.9%, followed by JCPyV (69.5%), RVA (23.9%) and NoV GII (7.4%). Viral concentrations ranged from 10(2) to 10(6) GC L(-1) and viruses were more likely to be detected during the flood season, with the exception of NoV GII, which was detected only during the dry season. Statistically significant differences on virus concentrations between dry and flood seasons were observed only for RVA. The HAdV data provides a useful complement to faecal indicator bacteria in the monitoring of aquatic environments. Overall results demonstrated that the hydrological cycle of the Negro River in the Amazon Basin affects the dynamics of viruses in aquatic environments and, consequently, the exposure of citizens to these waterborne pathogens.

  6. Validación de genotipos de frijol negro en la zona central del Estado de Veracruz, México

    Directory of Open Access Journals (Sweden)

    Francisco Javier Ugalde Acosta

    2005-01-01

    Full Text Available Validación de genotipos de frijol negro en la zona central del estado de Veracruz, México. El objetivo del presentetrabajo, fue validar genotipos de frijol con el paquete tecnológico del INIFAP, en parcelas de productores. Durante los ciclosde humedad residual de 1998 a 2001 se establecieron nueveparcelas de validación. Los genotipos utilizados fueron: las lí-neas II-307 y DOR-500 y las variedades Negro Huasteco 81,Negro Cotaxtla 91 y Negro INIFAPy como testigo del productor la variedad Jamapa. En las parcelas se realizaron las laboresde manejo agronómico recomendadas por el INIFAPpara esazona de producción. Cada parcela ocupó una superficie total de3000 m2. Se realizaron análisis de varianza individuales por localidad, considerando como repetición los rendimientos obtenidos por cada genotipo (500 m2 por ciclo de evaluación; también se efectuaron análisis combinado con prueba deseparación de medias (DMS 5% y un análisis económico mediante la Tasa de Retorno Marginal. Los resultados indicaronque las variedades y líneas mejoradas fueron superiores en másdel 100% en rendimiento al testigo. El análisis económicomostró que el mayor beneficio económico se obtuvo al sembrarlas variedades Negro INIFAPy Negro Cotaxtla 91, con utilidades superiores a los US $ 286/ha y una relación beneficio/costo de 1,52 y 1,51, respectivamente.

  7. Radiación no térmica en el entorno de agujeros negros acretantes

    OpenAIRE

    Vieyro, Florencia Laura

    2010-01-01

    El propósito de la presente tesis es presentar un estudio de los efectos de la componente no-térmica en la corona, y ver si esto produce alguna característica distintiva en el espectro electromagnético que pueda ser detectada por instrumentos de última generación, tales como Fermi/GLAST y AGILE. Primero, en el Capítulo 2, se caracteriza la corona de un agujero negro usando algunas hipótesis básicas, que permiten estimar los valores de los parámetros físicos relevantes, como el campo magnét...

  8. El color negro: dimensión pedagógica y cultural

    OpenAIRE

    Ruiz Sacristán, Lucía

    2014-01-01

    El color y su simbología son una realidad que lleva formando parte de nuestro entorno social a lo largo de toda la historia. A través de ella, hallaremos el origen y naturaleza de la simbología del color, deteniéndonos en todas las modificaciones pertinentes que éste ha ido sufriendo, haciendo especial hincapié en el color negro y su trayectoria. Además, con el presente trabajo damos a conocer el lenguaje del color y su importancia en nuestra sociedad. A su vez, se plasmará en una propuest...

  9. Textures, mineralogy and mineral chemistry of the Cerro de Maimón deposit (Dominican Republic): Weathering and metallurgical implications

    OpenAIRE

    Andreu Tàrrega, Eloi

    2010-01-01

    The aim of this thesis is to study the textures mineralogy, and mineral chemistry of the sulfide and oxide ores from the Cerro de Maimón deposit (a Cu-(Zn)-Au-Ag VMS deposit) in the Dominican Republic. The samples studied were collected by the author in June 2009 as part of an internship done at the Cerro de Maimón mine. The deposit is hosted in Maimón Formation, a metamorphosed and deformed volcanogenic bimodal suite formed in the first stages of the development of the primitive Caribbean is...

  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. SITE CHARACTERISTICS OF THE SUMMIT OF CERRO CHAJNANTOR AT THE 5640 M ALTITUDE

    Directory of Open Access Journals (Sweden)

    K. Motohara

    2011-01-01

    Full Text Available Instituto de Astronomía de la Universidad de Tokio está promoviendo el proyecto TAO (University of Tokyo Atacama Observatory; Yoshii et al. 2010 para construir un telescopio infrarrojo en la cima de Cerro Chajnantor (altitud 5640 m en el desierto de Atacama en el Norte de Chile. Para la evaluación de las características del sitio, primero se realizó el monitoreo del tiempo atmosférico, la emisividad de nubes y el seeing durante 2006. 2007. La fracción despejada fue alta (>80% y la mediana del seeing en la banda V fue de tan solo 0."69. Un telescopio explorador de 1 m llamado miniTAO fue instalado y comenzó a observar en 2009. Con éste se han obtenido imágenes satisfactorias de Paα de hidrógeno 1.875 μm como también imágenes de 30.40 μm por primera vez desde un telescopio en tierra. Estos resultados demuestran que la cima de Cerro Chajnantor es uno de los mejores sitios para la astronomía infrarroja en la Tierra.

  12. Elemental analysis of pottery from Cerro de las Ventanas, Zacatecas, by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Mireles G, F. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Mendez C, R. Y. [Universidad Autonoma de Zacatecas, Unidad Academica de Antropologia, Apdo. Postal 555 Suc. C, Zacatecas (Mexico); Nicolas C, M. [Universidad Autonoma de San Luis Potosi, Coordinacion de Ciencias Sociales y Humanidades, Av. Industrias 101-A, Fracc. Talleres, 78494 San Luis Potosi (Mexico); Speakman, R. J. [Museum Conservation Institute, Smithsonian Institution, Suitland, 20746 Maryland (United States); Glascock, M. D. [Reactor Center, University of Missouri, Columbia, 65211 Missouri (United States)

    2009-10-15

    Fifteen ceramic fragments samples from Cerro de las Ventanas site, Zacatecas, were analyzed by instrumental neutron activation analysis. Thirty-two elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Cluster analysis and principal component analysis were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Meso american ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Mal paso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de las Ventanas represent a new and unique chemical fingerprint in the region. (Author)

  13. A first shallow firn-core record from Glaciar La Ollada, Cerro Mercedario, central Argentine Andes

    Science.gov (United States)

    Bolius, David; Schwikowski, Margit; Jenk, Theo; Gäggeler, Heinz W.; Casassa, Gino; Rivera, Andrés

    In January 2003, shallow firn cores were recovered from Glaciar Esmeralda on Cerro del Plomo (33°14‧ S, 70°13‧ W; 5300 ma.s.l.), central Chile, and from Glaciar La Ollada on Cerro Mercedario (31°58‧ S, 70°07‧ W; 6070 ma.s.l.), Argentina, in order to find a suitable archive for paleoclimate reconstruction in a region strongly influenced by the El Niño-Southern Oscillation. In the area between 28° S and 35° S, the amount of winter precipitation is significantly correlated to the Southern Oscillation Index, with higher values during El Niño years. Glaciochemical analysis indicates that the paleo-record at Glaciar La Ollada is well preserved, whereas at Glaciar Esmeralda the record is strongly influenced by meltwater formation and percolation. A preliminary dating of the Mercedario core by annual-layer counting results in a time-span of 17 years (1986-2002), yielding an average annual net accumulation of 0.45 m w.e.

  14. Optical Sky Brightness at Cerro Tololo Inter-American Observatory from 1992 to 2006

    CERN Document Server

    Krisciunas, Kevin; Sanhueza, Pedro; Schwarz, Hugo E; Semler, Dylan R; Suntzeff, Nicholas B; Vera, Sergio

    2007-01-01

    We present optical UBVRI sky brightness measures from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m telescopes. The B- and V-band data are in reasonable agreement with measurements previously made at Mauna Kea, though on the basis of a small number of images per year there are discrepancies for the years 1992 through 1994. Our CCD-based data are not significantly different than values obtained at Cerro Paranal. We find that the yearly averages of V-band sky brightness are best correlated with the 10.7-cm solar flux taken 5 days prior to the sky brightness measures. This implies an average speed of 350 km/sec for the solar wind. While we can measure an enhancement of the night sky levels over La Serena 10 degrees above the horizon, at elevation angles above 45 degrees we find no evidence that the night sky brightness at Cerro Tololo is affected by artificial light of nearby towns and cities.

  15. Cerro de Pasco and other massive sulfide deposits of central Peru

    Energy Technology Data Exchange (ETDEWEB)

    Cheney, E.S.

    1985-01-01

    The famous Cerro de Pasco Pb-Zn-Ag deposit historically has been considered to be hydrothermally derived from an adjacent Tertiary volcanic vent. However, texturally massive pyrite-chert and pyrite-sphalerite-galena in the deposit have the same strike and cross folds as the adjacent pre-Tertiary strata. Both the deposit and the strata are cut by one of the large Longitudinal Faults. Both dikes and pyrite-enargite veins associated with the vent cut the massive sulfides; fragments of massive pyrite occur in the vent. A few examples of laminated pyrite and chert, banded pyrite and chert, banded pyrite and sphalerite, and banded pyrite, sphalerite, and galena are preserved in the massive sulfide portion of the deposit. The deposit has the composition and zoning patterns typical of shale-hosted massive sulfides. Cerro de Pasco probably in part of the pelitic Devonian Excelsior formation. The Colquijirca deposit 8 km to the south and the San Cristobal district 110 km to the south likewise have been considered to be Tertiary volcanic hydrothermal deposits. Colquijirca consists of stratigraphically controlled mantos of layered pyrite, chert and tuff in the Tertiary Calera formation. The mantos of the San Cristobal district are along the upper contact of the pyritic, Permian, Catalina felsic volcanic rocks; some ore consists of laminated pyrite and sphalerite. Tertiary plutons are conspicuously absent at San Cristobal, and the ores are brecciated by Tertiary folding.

  16. Dating thermal events at Cerro Prieto using fission-track annealing

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, S.J.; Elders, W.A.

    1981-01-01

    The duration of heating in the Cerro Prieto reservoir was estimated by relating the fading of spontaneous fission tracks in detrital apatite to observed temperatures. The rate of fading is a function of both time and temperature. The apparent fission track age of the detrital apatites then, is a function of both their source age and their time-temperature history. Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures. The temperature in well T-366, where complete annealing first occurs, was estimated to be between 160 and 180{sup 0}C. Complete annealing at these temperatures requires 10{sup 4} and 10{sup 3} years, respectively. Well M-94 has an apparently complex thermal history. Geothermometers in this well indicate temperatures some 50 to 100{sup 0}C higher than those measured directly in the borehole. Fission tracks are partially preserved in M-94 where paleotemperatures were as high as 200{sup 0}C and are erased where geothermometers indicate temperatures of 250{sup 0}C. This implies a thermal event less than 10{sup 1} years and greater than 10{sup 0} years in duration.

  17. Elemental analysis of pottery from Cerro de las Ventanas, Zacatecas, by INAA

    International Nuclear Information System (INIS)

    Fifteen ceramic fragments samples from Cerro de las Ventanas site, Zacatecas, were analyzed by instrumental neutron activation analysis. Thirty-two elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Cluster analysis and principal component analysis were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Meso american ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Mal paso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de las Ventanas represent a new and unique chemical fingerprint in the region. (Author)

  18. Comments on the Neolithic collective burial at Cerro Virtud (Cuevas de Almanzora, Almería

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    1999-06-01

    Full Text Available Different results from the collective burial of Cerro Virtud confirm the importance of this settlement for our understanding of the Neolithic in southeastern Iberian Peninsula. The site has both open air settlement and collective burial. It also has the first evidence of Neolithic metalworking in Western Europe. The article focuses on the collective burial. Anthropological analysis shows eleven individuals, some of them in primary positions and others displaced. A radiocarbon sequence of the burial is also pesented. The burial chronology is in the first half of V millennium cal EC.

    El estudio del enterramiento colectivo de Cerro Virtud confirma la importancia de este yacimiento en el desarrollo cronológico y cultural del Neolítico Medio en el Sureste de la Península Ibérica. Además de tratarse de un poblado al aire libre y contar con la primera evidencia de actividad metalúrgica de época neolítica documentada en el Occidente de Europa, presenta un enterramiento colectivo sobre el que se centra este artículo. Los resultados del análisis antropológico indican la presencia de, al menos, once individuos inhumados, unos en posición primaria y otros desplazados. Se aportan las nuevas dataciones de carbono 14 que sitúan cronológicamente al enterramiento en la primera mitad del V milenio cal AC.

  19. 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

    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.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

  20. Neoproterozoic to Lower Palaeozoic successions of the Tandilia System in Argentina: implication for the palaeotectonic framework of southwest Gondwana

    Science.gov (United States)

    Zimmermann, Udo; Poiré, Daniel G.; Peral, Lucía Gómez

    2011-04-01

    The Cryogenian to Uppermost Ediacaran successions of the Tandilia System (Sierras Bayas Group and Cerro Negro Formation) in central-eastern Argentina is exceptional because of its unmetamorphosed and nearly undeformed character, its sediment provenance trend and the absence of any identified glacial deposit and the deposition of warm water carbonates. We decipher a dramatic change in the basin evolution from small-scale depositional areas during the Neoproterozoic to a larger basin related to an active continental margin throughout the Uppermost Ediacaran. The base of the succession is represented by immature detritus of alkaline composition (Villa Mónica Formation), but towards the top of this formation, the material is sorted and reworked, nonetheless still reflecting in its detritus the local rocks. The clastic deposition is interrupted by diagenetic overprinted dolomites. The unconformable overlying quartz-arenitic Ediacaran Cerro Largo Formation reworked the Cryogenian Villa Mónica Formation and contains mainly felsic granitic and metamorphic basement material of slightly wider variety, while the dominant alkaline geochemical signature in rocks of the Villa Mónica Formation disappears. Based on diagenetic, petrographic and sedimentological data, we can interpret the unconformity representing a longer time of erosion. The Cerro Largo Formation shows a transition to mudstones and the heterolithic facies of the Olavarría Formation. The top of the Sierras Bayas Group is represented by limestones (Loma Negra Formation), which are discordantly overlain by the Uppermost Ediacaran Cerro Negro Formation. The latter displays detrital material derived from a continental arc, mafic and felsic sources. Several arc-related geochemical proxies (Th/Sc 20) are recorded in the sediment detritus, as are syn-depositional pyroclastites. The absence of volcanic material in the underlying rocks allows proposing that the Cerro Negro Formation is related to an active continental

  1. Presence of cross flow in the Cerro Prieto geothermal field, BC; Presencia de flujo cruzado en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez, Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2011-01-15

    During the development of Cerro Prieto geothermal field, BC, exploitation has increased gradually, causing a continuous drop in pressure to almost 100 bars in the central and eastern parts of the field. This has occurred despite the high natural recharge induced by the reservoir exploitation and helped by the high permeability of the reservoir and the wide availability of natural recharge of low-temperature water in the vicinity. The strata above the production zones have significantly lower temperatures than these zones, but due to the particular characteristics of the reservoir, do not have pressure drops. As the pressure of producing strata declines, the hydraulic pressure differential between them and the overlying strata increases. Thus in recent years the phenomenon of cross flow occurs with greater frequency and severity. In this paper, this phenomenon is analyzed, detailing the specific mechanisms favoring it and identifying the stage (drilling or workover) in which it commonly occurs. Rigorous supervision during these stages is crucial to identifying cross flow and to taking necessary measures to save the well. Cross flow cases are presented at different stages in the history of a well: during drilling, repair, before and during the stimulation, and during production. [Spanish] Durante el desarrollo del campo geotermico de Cerro Prieto, BC, la explotacion se ha incrementado en forma gradual provocando una continua caida de presion, que en las porciones central y oriente ha sido de casi 100 bars. Esto ha ocurrido a pesar de la enorme recarga natural inducida por la explotacion, favorecida por la alta permeabilidad del yacimiento y la gran disponibilidad de recarga natural de agua de baja temperatura en los alrededores del mismo. Los estratos ubicados encima de las zonas productoras presentan temperaturas significativamente menores que estos, pero debido a las caracteristicas particulares del yacimiento, no han presentado abatimiento en su presion. En la

  2. Forest succession in the Upper Rio Negro of Colombia and Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Saldarriaga, J.G.; West, D.C.; Tharp, M.L.

    1986-11-01

    Woody vegetation from 23 forest stands along the Upper Rio Negro of Venezuela and Colombia was sampled in 1982 to examine the hypothesis that the Amazon forest has been largely undisturbed since the Pleistocene, to quantify vegetation development during different stages of succession following agricultural development, and to determine the time required for a successional stand to become a mature forest. The ubiquitousness of charcoal in the tierra firme forest indicated the presence of fire associated with extreme dry periods and human disturbances. Changes in species composition, vegetation structure, and woody biomass were studied on 19 abandoned farms and four mature forest stands. Living and dead biomass for the tress and their components was determined by regression equations developed from measurements of harvested trees. The rate of recovery of floristic composition, structure, and biomass following disturbance is relatively slow. Aboveground dead biomass remained high 14 years after the forest was disturbed by the agricultural practices. The lowest dead biomass is reached 20 years after abandonment, and the largest values are found in mature forests. Data analysis of 80-year-old stands showed that the species composition approached that of a mature forest. Approximately 140 to 200 years was required for an abandoned farm to attain the basal area and biomass values comparable to those of a mature forest. The results of this study indicate that recovery is five to seven times longer in the Upper Rio Negro than it is in other tropical areas in South America.

  3. TOTAL MERCURY (HgT BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    Directory of Open Access Journals (Sweden)

    Jean Louchard Ferreira Soares

    2016-03-01

    Full Text Available In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were distributed in the basin of the Negro river during the period of high water. After the fisheries specimens were identified, measured and weighed. Then muscle samples were taken and subjected to acid digestion and analyzed by Cold Vapor Atomic Fluorescence Spectrophotometer - CVAFS. To research data was used analysis of variance and linear regression. A total of 264 specimens distributed into 10 species were analyzed, and the THg of the concentrations ranged from 0.030 for 1,670 mg.kg-1. The species Hoplias malabaricus, Serrasalmus rhombeus, Hemiodus immaculatus and Cichla temensis showed bioaccumulation. High concentrations of THg were found in carnivorous, piscivorous, planctívos and omnivores fish. No specimen showed mean concentrations of THg in violation to ANVISA, but this occurred in relation to FAO and WHO. keywords: Brazilian Amazon; biomonitoring; high waters; Hg.

  4. Forest succession in the Upper Rio Negro of Colombia and Venezuela

    International Nuclear Information System (INIS)

    Woody vegetation from 23 forest stands along the Upper Rio Negro of Venezuela and Colombia was sampled in 1982 to examine the hypothesis that the Amazon forest has been largely undisturbed since the Pleistocene, to quantify vegetation development during different stages of succession following agricultural development, and to determine the time required for a successional stand to become a mature forest. The ubiquitousness of charcoal in the tierra firme forest indicated the presence of fire associated with extreme dry periods and human disturbances. Changes in species composition, vegetation structure, and woody biomass were studied on 19 abandoned farms and four mature forest stands. Living and dead biomass for the tress and their components was determined by regression equations developed from measurements of harvested trees. The rate of recovery of floristic composition, structure, and biomass following disturbance is relatively slow. Aboveground dead biomass remained high 14 years after the forest was disturbed by the agricultural practices. The lowest dead biomass is reached 20 years after abandonment, and the largest values are found in mature forests. Data analysis of 80-year-old stands showed that the species composition approached that of a mature forest. Approximately 140 to 200 years was required for an abandoned farm to attain the basal area and biomass values comparable to those of a mature forest. The results of this study indicate that recovery is five to seven times longer in the Upper Rio Negro than it is in other tropical areas in South America

  5. Anthropogenic impact of mercury accumulation in fish from the Rio Madeira and Rio Negro rivers (Amazonia).

    Science.gov (United States)

    Dórea, José G; Barbosa, Antonio C

    2007-03-01

    Fish is an important concentrator of mono-methyl mercury and the main route to human contamination. We compared fish Hg bioaccumulation (within similar weight ranges) in two Amazonian river habitats during high-water seasons. The Rio Madeira has been greatly impacted by agriculture, alluvial gold extraction, and a hydroelectric reservoir, whereas the Rio Negro is much less affected by these human activities. The species at the top of the food web, Hoplias malabaricus (piscivorous; 80-668 ng Hg/g) and Cichla spp. (piscivorous; 42-747 ng Hg/g) showed the highest range of Hg concentrations. Nonpiscivorous species with comparable weight range, such as Potamorhina latior (detritivorous; 20-157 ng Hg/g) and Myleus torquatus (herbivorous; 2-182 ng Hg/g), had lower Hg concentrations. Triportheus elongatus (omnivorous; 5-350 ng Hg/g), with the lowest weight range, also showed a low range of Hg concentrations. Despite the Rio Madeira's higher sediment load as well as environmental impacts (deforestation, agriculture, hydroelectric reservoir, and alluvial gold mining) on natural Hg release, fish Hg bioaccumulation was no different between the two river habitats for nonpiscivorous species. In this small observational study only the species at the top of the food web (M. torquatus, Cichla spp, T. elongatus) showed higher mean Hg concentrations in the Rio Madeira than the dominantly wilderness habitat of the Rio Negro.

  6. Factors affecting Hg (II adsorption in soils from the Rio Negro basin (Amazon

    Directory of Open Access Journals (Sweden)

    Patricia Miretzky

    2005-06-01

    Full Text Available Mercury (II adsorption studies in top soils (top 10 cm from the Rio Negro basin show this process depends strongly on some selected parameters of the aqueous phase in contact with the soils. Maximum adsorption occurred in the pH range 3.0-5.0 (>90%. Dissolved organic matter shows an inhibitory effect on the availability of Hg (II to be adsorbed by the soils, whereas a higher chloride content of the solution resulted in a lower adsorption of Hg (II at pH 5.0. Soils with higher organic matter content were less affected by changes in the salinity. An increase in the initial Hg (II concentration increased the amount of Hg (II adsorbed by the soil and decreased the time needed to reach equilibrium. A Freundlich isotherm provided a good model for Hg (II adsorption in the two types of soil studied. The kinetics of Hg (II adsorption on Amazonian soils showed to be very fast and followed pseudo-second order kinetics. An environmental implication of these results is discussed under the real scenario present in the Negro River basin, where acidic waters are in contact with a soil naturally rich in mercury.

  7. Hantavirus pulmonary syndrome in the Province of Rio Negro, Argentina, 1993-1996.

    Science.gov (United States)

    Cantoni, G; Lazaro, M; Resa, A; Arellano, O; Amestoy, A M; De Bunder, S; Herrero, E; Perez, A; Larrieu, E

    1997-01-01

    Early in 1995 the first case of Hantavirus Pulmonary Syndrome was serologically confirmed in El Bolsón (Province of Río Negro, Argentina), corresponding to the third outbreak reported in Argentina. A total of 26 cases of HPS related to the Andean region of Rio Negro Province, were reported from 1993 to 1996, 17 in El Bolsón, 4 in San Carlos de Bariloche, and 5 in Buenos Aires. The incidence rate was 5.03 x 100,000 with a mortality rate of 51.85 x 100. The occurrence of cases was mainly seasonal, with a significantly greater number in the spring, and the persons affected mainly lived in urban or periurban areas. In four cases, the affected individuals were members of a couple, spouses or live-in contacts. Seven cases were Health workers (physicians, nurses or administrative staff). Twelve cases were related among them, due to an outbreak of 80 days. Two of them did not visit the Andean region. A total of 139 rodents were captured and seven of them, Olygoryzomys longicaudatus, were found to be serologically positive. The possibility of infection by contact with rodents or fecal matter is being analyzed and also hypothesis related with interhuman transmission.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. 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

  11. 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.

  12. Minimal thermodynamic conditions in the reservoir to produce steam at the Cerro Prieto geothermal field, BC; Condiciones termodinamicas minimas del yacimiento para producir vapor en el campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2009-01-15

    Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.

  13. Extension of the Cerro Prieto field and zones in the Mexicali Valley with geothermal possibilities in the future

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca L, H.L.; de la Pena L, A.; Puente C, I.; Diaz C, E.

    1981-01-01

    This study concerns the possible extension of the Cerro Prieto field and identification of other zones in the Mexicali Valley with geothermal development potential by assessing the structural geologic conditions in relation to the regional tectonic framework and the integration of geologic and geophysical surveys carried out at Cerro Prieto. This study is based on data obtained from the wells drilled to date and the available geological and geophysical information. With this information, a geologic model of the field is developed as a general description of the geometry of what might be the geothermal reservoir of the Cerro Prieto field. In areas with geothermal potential within the Mexicali Valley, the location of irrigation wells with anomalous temperatures was taken as a point of departure for subsequent studies. Based on this initial information, gravity and magnetic surveys were made, followed by seismic reflection and refraction surveys and the drilling of 1200-m-deep multiple-use wells. Based on the results of the final integration of these studies with the geology of the region, it is suggested that the following areas should be explored further: east of Cerro Prieto, Tulecheck, Riito, Aeropuerto-Algodones, and San Luis Rio Colorado, Sonora.

  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. Geología de la región del Cerro Guanaquero, Río Diamante, Mendoza Geology of Cerro Guanaquero region, Diamante River, Mendoza

    Directory of Open Access Journals (Sweden)

    Federico Fuentes

    2008-03-01

    Full Text Available El estudio realizado presenta nuevos datos sobre un sector poco conocido de la Cordillera Principal de Mendoza, en la alta cuenca del río Diamante en las adyacencias del cerro Guanaquero, y los primeros datos geocronológicos de sus rocas volcánicas. Las unidades geológicas presentes en el área se dividen en cuatro grupos principales: secuencias sedimentarias mesozoicas marinas y continentales intensamente plegadas y falladas; intrusivos y volcanitas intermedias de edad neógena; rocas volcánicas pliocenas a recientes de composición intermedia a básica, y depósitos cuaternarios inconsolidados. El cerro Guanaquero, un estratovolcán pliocuaternario intensamente erosionado por glaciares pleistocenos, con sus 4.841 metros es el rasgo orográfico más prominente. Está constituido esencialmente por andesitas grises porfíricas, piroxénicas a biotíticas. Intercaladas con las coladas andesíticas se presentan depósitos piroclásticos, aglomerados volcánicos, ignimbritas y basaltos. La datación de una andesita por el método K-Ar en roca total arrojó una edad de 1,4 ± 0,1 Ma. La deformación ándica comenzó en forma de una faja plegada y corrida de piel fina, con pliegues por despegue en el sector occidental y por propagación de falla en el oriental. La compresión al oeste de los 69º47´O terminó por invertir la fallas normales del rift mesozoico. A lo largo de este meridiano se encuentra la falla más importante de la región, la que se ha correlacionado con la falla Malargüe, bien desarrollada en latitudes más australes. Esta falla limita la faja plegada y corrida del Aconcagua, de naturaleza epidérmica, y la faja plegada y corrida de Malargüe, controlada por la inversión tectónica del basamento. El volcanismo fue muy intenso en el Plioceno y el Cuaternario, correspondiendo a un período de empinamiento de la placa oceánica subducida, en el que la región ha sido levantada pasivamente. La alta resistencia a la erosión de

  16. Fermented nondigestible fraction from common bean (Phaseolus vulgaris L.) cultivar Negro 8025 modulates HT-29 cell behavior.

    Science.gov (United States)

    Cruz-Bravo, R K; Guevara-Gonzalez, R; Ramos-Gomez, M; Garcia-Gasca, T; Campos-Vega, R; Oomah, B D; Loarca-Piña, G

    2011-03-01

    The aim of the study was to evaluate the effect of a fermented nondigestible fraction (FNDF) of cooked bean (Phaseolus vulgaris L.) cultivar Negro 8025 on human colon adenocarcinoma HT-29 cell survival. Negro 8025 was chosen for in vitro fermentation based on comparison of chemical composition with 2 other cultivars: Azufrado Higuera and Pinto Durango. Negro 8025 had 58% total dietary fiber, 27% resistant starch, and 20 mg of (+)-catechin equivalents per gram of sample. Short-chain fatty acids (SCFAs) production and pH of the medium were measured after fermentation as indicators of colon protection through induced arrest on cell culture and apoptosis. Butyrate and pH of FNDF of Negro 8025 were higher than the control fermented raffinose extract. The FNDF inhibited HT-29 cell survival in a time- and concentration-dependent manner. The lethal concentration 50 (LC(50)) was 13.63% FNDF (equivalent to 7.36, 0.33, and 3.31 mmol of acetic, propionic, and butyric acids, respectively). DNA fragmentation, an apoptosis indicator, was detected by the TdT-mediated dUTP nick end labeling method in cells treated with the LC(50)-FNDF and a synthetic mixture of SCFAs mimicking LC(50)-FNDF. Our results suggest that common bean is a reliable source of fermentable substrates in colon, producing compounds with potential chemoprotective effect on HT-29 colon adenocarcinoma cells, so it may present an effective alternative to mitigate colon cancer development.

  17. Food, feeding, and refuelling of Red Knots during northward migration at San Antonio Oeste, Rio Negro, Argentina

    NARCIS (Netherlands)

    Gonzalez, PM; Piersma, T; Verkuil, Y; González, Patricia M.

    1996-01-01

    We studied the food and feeding ecology of Red Knots Calidris canutus rufa on an area of rocky flat, or restinga, near San Antonio Oeste in the northwest of Golfo San Matias, Provincia de Rio Negro, Argentina in March 1992. These Red Knots are on their way north, from ''wintering'' areas in Tierra d

  18. Death at an Early Age: The Destruction of the Hearts and Minds of Negro Children in the Boston Public Schools.

    Science.gov (United States)

    Kozol, Jonathan

    This book recounts the author's experience of teaching in a predominantly Negro elementary school in Boston as part of a program to upgrade segregated schools. He describes specific incidents to convey the bigoted attitudes of the teachers and other authorities, which he feels were manifest in their behavior and in the curriculum and activities of…

  19. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba

    Directory of Open Access Journals (Sweden)

    D. Mutti

    2005-03-01

    Full Text Available La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4 y estructuras penetrativas (S2, S3 y S4 que se desarrollaron desde el Pampeano hasta el Famatiniano inclusive, favoreciendo la intrusión anorogénica del batolito Cerro Áspero a partir del Devónico tardío. Como consecuencia del evento magmático fueron reactivadas las estructuras, movilizando fluidos hidrotermales por las anisotropías del terreno y debajo de un nivel de anfibolitas macizo que actuó como una barrera impermeable. La acción de un esfuerzo máximo s1 (330º contribuyó al desarrollo del sistema mineralizado siguiendo el patrón de fracturamiento del modelo de Riedel y propició la construcción del lineamiento mineral principal en una faja de cizalla simple dextral de posición 285º (S5. El fluido magmático - hidrotermal evolucionó mediante numerosos pulsos de ruptura y apertura de las inhomogeneidades rocosas, con sellado de cavidades por mecanismos de cierre con fracturamiento y relleno y disolución por presión. Estos mecanismos precipitaron sílice con hábito fibroso y reconcentraron elementos metálicos bajo un régimen de tracción y presión de fluido de poro estimada en 195 MPa. La edad de la mineralización de uno de sus estadios fue determinada en 343,8 ± 10,8 Ma, mediante una datación K/Ar en muscovita.

  20. 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...

  1. Arterial oxygen saturation in healthy newborns delivered at term in Cerro de Pasco (4340 m and Lima (150 m

    Directory of Open Access Journals (Sweden)

    Gonzales Gustavo F

    2005-09-01

    Full Text Available Abstract Background High altitude is associated with both low pulse oxygen saturation at birth and more pre-term deliveries. The present study was performed to determine pulse oxygen saturation in newborns at term in Cerro de Pasco (4340 m and Lima (150 m to test the hypothesis that low pulse oxygen saturation at birth at high altitudes was not observed at term deliveries. Methods The present study was designed to determine pulse oxygen saturation values through 1 minute to 24 hours and values of Apgar score at 1 and 5 minutes in newborns delivered at term in Cerro de Pasco (4340 m and Lima (150 m. Pulse oxygen saturation was recorded in 39 newborns from Cerro de Pasco (4340 m and 131 from Lima (150 m at 1, 2, 3, 4, 5, 10, 15, 30 minutes and 1, 2, 8 and 24 hours after delivery. Apgar score was assessed at 1 and 5 minutes after birth. Neurological score was assessed at 24 h of birth by Dubowitz exam. Results Pulse oxygen saturation increased significantly from 1 to 15 min after birth at sea level and from 1 to 30 minutes at Cerro de Pasco. Thereafter, it increased slightly such that at 30 min at sea level and at 60 minutes in Cerro de Pasco it reached a plateau up to 24 hours after birth. At all times, pulse oxygen saturation was significantly higher at sea level than at high altitude (P Conclusion From these analyses may be concluded that pulse oxygen saturation at 4340 m was significantly low despite the fact that births occurred at term. Apgar scores at first minute and neurological scores were also lower at high altitudes.

  2. 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...

  3. Aprendendo a ser negro: a perspectiva dos estudantes Learning to be black: the students' perspective

    Directory of Open Access Journals (Sweden)

    Marzo Vargas dos Santos

    2011-08-01

    Full Text Available O artigo trata de identificar e compreender de que modo os estudantes negros da rede municipal de ensino de Porto Alegre constituem interações sociais, e como essas se manifestam na cultura estudantil e na Educação Física. Por meio de uma etnografia educativa, reflete sobre a participação do negro na construção da sociedade, que não é isenta de contradições e controvérsias. Os autores realizam análise de documentos, observação participante, diário de campo, grupos de discussão e entrevista semiestruturada. A análise enfatiza o modo pelo qual os colaboradores do estudo se percebem nas relações étnico-raciais, ao tratar dos códigos de significados na cultura estudantil, especialmente quanto ao seu reconhecimento no grupo, revelando que os negros manifestam certa naturalização de uma posição social de inferioridade. As diferentes culturas da escola dão sentidos distintos às ações, rituais e códigos que serão interpretados por aqueles envolvidos com os elementos dessa cultura.The article seeks to identify and understand the mode in which Afro-Brazilian students in the municipal school system of Porto Alegre constitute their social interactions and how such constructions manifest themselves amongst student culture and in Physical Education classes. Using educational ethnography, it reflects on afro participation in the construction of a society that is full of contradictions and controversies. The authors analyzed documents, used participant observation, kept a field diary, led discussion groups and conducted semi-structured interviews. The analysis emphasizes the way in which the study's subjects perceived themselves in ethno-racial relationships when dealing with the codes of student culture, especially when identifying themselves in relation to the group, revealing that Afro-Brazilians manifest a certain naturalization of a social position of inferiority. The different cultures in the school lend different

  4. SIMULACIÓN DE LA RADIACIÓN ESPECTRAL DE CUERPO NEGRO A DIFERENTES TEMPERATURAS

    Directory of Open Access Journals (Sweden)

    Zoraida Morantes

    2008-05-01

    Full Text Available En esta investigación se generaron dos interfaces gráficas de usuario en Matlab, con la finalidad de ser utilizadas como material de apoyo en la enseñanza experimental de la Física Cuántica, para el análisis de la ley de radiación de Planck. Para ello, se realizó la comparación y validación de la funcionalidad de las interfaces como herramienta de simulación, con datos existentes relacionados con la radiación espectral de un cuerpo negro en el rango infrarrojo, visible y ultravioleta a diferentes temperaturas, demostrando gráficamente que el valor de longitud de onda donde ocurre el máximo de la distribución espectral de la radiación de un cuerpo negro se desplaza a valores más pequeños en la medida que la temperatura se incrementa. Así mismo, se logró: obtener el valor de la intensidad total irradiada para dichas temperaturas a un valor particular de longitud de onda, demostrar gráficamente que la intensidad total irradiada por un cuerpo negro que corresponde al área bajo la curva se incrementa con la temperatura, obtener a partir de la información que ofrece la interfaz el valor de la constante de Planck usando la Ley de Wien, graficar la distribución espectral del tungsteno para diferentes temperaturas comparando los resultados con las curvas teóricas y las obtenidas aplicando LabVIEW (Laboratory Virtual Instrument Engineering Workbench. El trabajo fue abordado como una investigación documental (Arias, 1999, de tipo aplicativa y evaluativo (Padrón, 2000. La validación de las interfaces permitió considerar su incorporación a un sistema multimedia que se esta desarrollando en los Laboratorios de Física de la Facultad de Ingeniería de la Universidad del Zulia, y el Laboratorio de Física y Electrónica de la Universidad Rafael Belloso Chacín, con la finalidad de optimizar el aprendizaje y enseñanza de la física.

  5. 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.

  6. Mid amphibolite facies metamorphism of harzburgites in the Neoproterozoic Cerro Mantiqueiras Ophiolite, southernmost Brazil

    Directory of Open Access Journals (Sweden)

    HARTMANN LÉO A.

    2003-01-01

    Full Text Available Valuable information is retrieved from the integrated investigation of the field relationships, microstructure and mineral compositions of harzburgites from the Neoproterozoic Cerro Mantiqueiras Ophiolite. This important tectonic marker of the geological evolution of southernmost Brazilian Shield was thoroughly serpentinized during progressive metamorphism, because the oldest mineral assemblage is: olivine + orthopyroxene + tremolite + chlorite + chromite. This M1 was stabilized in mid amphibolite facies - 550-600ºC as calculated from mineral equilibria. No microstructural (e.g. ductile deformation of olivine or chromite or compositional (e.g. mantle spinel remnant of mantle history was identified. A metamorphic event M2 occurred in the low amphibolite facies along 100 m-wide shear zones, followed by intense serpentinization (M3 and narrow 1-3 m-wide shear zones (M4 containing asbestos.

  7. A new MOS mask cutter facility at Gemini/Cerro Tololo observatories

    Science.gov (United States)

    Wyman, Robert T.; Trancho, Gelys; Tighe, Roberto

    2010-07-01

    The installation and commissioning of a new laser cutter facility in La Serena, Chile is a cooperative effort between Gemini Observatory and the Cerro Tololo Inter-American Observatory. This system enables the cutting of aluminum and carbon fiber slit masks for three multi-object spectrographs operating in Chile: GMOS-S, Flamingos-2, and Goodman spectrograph. Selection of the new laser cutter tool was based on slit mask specifications developed for two materials. Prior to the commissioning all slit mask production was performed at Gemini's Northern base facility with a similar laser cutter system. The new facility supports two observatories and enhances the capabilities for both. This paper will discuss the observatory arrangement with respect to mask data tracking and handling. The laser system and facility will be discussed along with mask cutting performance, process development and manufacturing methods.

  8. MOVIMIENTOS DE LADERA Y PLANEAMIENTO URBANÍSTICO: EL CONFLICTO DEL CERRO DEL OPE, ARCHENA (MURCIA

    Directory of Open Access Journals (Sweden)

    María Dolores Gómez Moreno

    2009-01-01

    Full Text Available Los desprendimientos son un proceso natural que afecta, de forma generalizada en el Valle de Ricote, a las laderas del tipo cantil-talud. Su peligrosidad radica en que los bloques desprendidos del escarpe ruedan con facilidad, talud abajo, cuando son descalzados por efecto de la escorrentía superfi cial o desestabilizados por movimientos sísmicos. El planeamiento urbanístico se convierte en factor inductor del riesgo al clasifi car como urbanizables y urbanos suelos que, por su ubicación en pie de ladera, deberían excluirse de cualquier proceso urbanizador. Este es el caso de Archena en el entorno inmediato del cerro del Ope.

  9. Study of the atmospheric conditions at Cerro Armazones using astronomical data

    CERN Document Server

    Lakicevic, Masha; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-01-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Cherenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using line-by-line radiative transfer model (LBLRTM) radiative transfer models for the Earths atmosphere with the telluric absorption correction tool molecfit. All observations from the archive in the period from December 2008 to the end of 2014 were investigated. The dataset completely covers the El Nino event registered in the period 2009-2010. Models of the 3D Global Data Assimilation System (GDAS) were used for further comparison. Moreover, for those days with coincidence of data from a similar study with VLT/X-shooter and microwave rad...

  10. Hydrothermal alteration of sediments associated with surface emissions from the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Valette-Silver, J.N.; Esquer P., I.; Elders, W.A.; Collier, P.C.; Hoagland, J.R.

    1981-01-01

    A study of the mineralogical changes associated with these hydrothermal vents was initiated with the aim of developing possible exploration tools for geothermal resources. The Cerro Prieto reservoir has already been explored by extensive deep drilling so that relationships between surface manifestations and deeper hydrothermal processes could be established directly. Approximately 120 samples of surface sediments were collected both inside and outside of the vents. The mineralogy of the altered sediments studied appears to be controlled by the type of emission. A comparison between the changes in mineralogy due to low temperature hydrothermal activity in the reservoir, seen in samples from boreholes, and mineralogical changes in the surface emission samples shows similar general trends below 180 C: increase of quartz, feldspar and illite, with subsequent disappearance of kaolinite, montmorillonite, calcite and dolomite. These mineral assemblages seem to be characteristic products of the discharge from high intensity geothermal fields.

  11. Burn Severities, Fire Intensities, and Impacts to Major Vegetation Types from the Cerro Grande Fire

    Energy Technology Data Exchange (ETDEWEB)

    Balice, Randy G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bennett, Kathryn D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wright, Marjorie A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2004-12-15

    The Cerro Grande Fire resulted in major impacts and changes to the ecosystems that were burned. To partially document these effects, we estimated the acreage of major vegetation types that were burned at selected burn severity levels and fire intensity levels. To accomplish this, we adopted independently developed burn severity and fire intensity maps, in combination with a land cover map developed for habitat management purposes, as a basis for the analysis. To provide a measure of confidence in the acreage estimates, the accuracies of these maps were also assessed. In addition, two other maps of comparable quality were assessed for accuracy: one that was developed for mapping fuel risk and a second map that resulted from a preliminary application of an evolutionary computation software system, called GENIE.

  12. Did stresses from the Cerro Prieto Geothermal Field influence the El Mayor-Cucapah rupture sequence?

    Science.gov (United States)

    Trugman, Daniel T.; Borsa, Adrian A.; Sandwell, David T.

    2014-12-01

    The Mw 7.2 El Mayor-Cucapah (EMC) earthquake ruptured a complex fault system in northern Baja California that was previously considered inactive. The Cerro Prieto Geothermal Field (CPGF), site of the world's second largest geothermal power plant, is located approximately 15 km to the northeast of the EMC hypocenter. We investigate whether anthropogenic fluid extraction at the CPGF caused a significant perturbation to the stress field in the EMC rupture zone. We use Advanced Land Observing Satellite interferometric synthetic aperture radar data to develop a laterally heterogeneous model of fluid extraction at the CPGF and estimate that this extraction generates positive Coulomb stressing rates of order 15 kPa/yr near the EMC hypocenter, a value which exceeds the local tectonic stressing rate. Although we cannot definitively conclude that production at the CPGF triggered the EMC earthquake, its influence on the local stress field is substantial and should not be neglected in local seismic hazard assessments.

  13. Structure and age of the Cerro de Pasco Cu-Zn-Pb-Ag deposit, Peru

    Science.gov (United States)

    Cheney, E. S.

    1991-04-01

    The world-famous Cu-Zn-Pb-Ag deposit at Cerro de Pasco, Peru, consists of texturally massive pyrite, texturally massive sphalerite-galena-pyrite, and veins containing pyrite and enargite. Historically the deposit has been considered to be the hydrothermal product of the adjacent Miocene volcanic and intrusive complex (locally known as the “Vent”). However, both the texturally massive sulfides of the deposit and the pre-Miocene strata are cut by the Longitudinal fault, one of the largest faults in the district, but the Vent is not. Imbrication by the Longitudinal fault zone (duplex structures) has thickened the deposit so that it is amenable to open-pit mining. Dikes and pyrite-enargite veins pass from the Vent into the massive sulfides; fragments of massive pyrite occur in the Vent. Thus, no matter what their origin, the texturally massive sulfides are older and, therefore, genetically unrelated to the Vent.

  14. Comments on some of the drilling and completion problems in Cerro Prieto geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A, B.; Sanchez G, G.

    1981-01-01

    From 1960 to the present, 85 wells with a total drilling length exceeding 160,000 m have been constructed at Cerro Prieto, a modest figure compared to an oil field. This activity took place in five stages, each characterized by changes and modifications required by various drilling and well-completion problems. Initially, the technical procedures followed were similar to those used in the oil industry. However, several problems emerged as a result of the relatively high temperatures found in the geothermal reservoir. The various problems that have been encountered can be considered to be related to drilling fluids, cements and cementing operations, lithology, geothermal fluid characteristics, and casings and their accessories. As the importance of high temperatures and the characteristics of the geothermal reservoir fluids were better understood, the criteria were modified to optimize well-completion operations, and satisfactory results have been achieved to date.

  15. [Reptiles from Cerro Colorado and its surroundings, Cumana, Sucre State, Venezuela].

    Science.gov (United States)

    Oliveros, O; Prieto, A; Comejo, P

    2000-01-01

    An inventory of the reptiles that inhabit in Cerro Colorado and its surroundings, was performed from March, 1994 to March, 1995. There were reported 8 species of snakes and 7 of lizards enclosed in 4 and 5 families repectively. Aspects observed were ecolology as habitat, activity, reproduction and relative abundance. The more abundant species of lizards were: Cnemidophorus femniscatus, Ameiva bifrontata, (Teiidae), Tropidurus hispidus (Tropiduridae), Gonatodes vittatus and Hemidactylus mabouia (Gekkonidae) and the ophidians: Leptodeira annulata and Mastigodryas amarali (Colubridae). It is believed that the changes occurred in the zone influenced the increase of the relative abundance of the species Leptotyphlops goudotii (Leptotyphlopidae) arid Gymnophthalmus speciosus(Gymnophthalmidae) and perhaps in the disappearance of others that have been reported at the xerophitic or semixerophitic zones of the Sucre State of Venezuela. PMID:11220219

  16. Dynamics of a geothermal field traced by noble gases: Cerro Prieto, Mexico

    Science.gov (United States)

    Mazor, E.; Truesdell, A.H.

    1984-01-01

    Noble gases have been measured mass spectrometrically in samples collected during 1977 from producing wells at Cerro Prieto. Positive correlations between concentrations of radiogenic (He and 40Ar) and atmospheric noble gases (Ne, Ar and Kr) suggest the following dynamic model: the geothermal fluids originated from meteoric water that penetrated to more than 2500 m depth (below the level of first boiling) and mixed with radiogenic He and 40Ar formed in the aquifer rocks. Subsequently, small amounts of steam were lost by a Raleigh process (0 - 30%) and mixing with shallow cold water occurred (0 - 30%). Noble gases are sensitive tracers of boiling in the initial stages of 0 - 3% steam separation and complement other tracers, such as C1 or temperature, which are effective only beyond this range. ?? 1984.

  17. Results of the latest transient well pressure tests at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Abril G, A.; Vargas G, C.

    1981-01-01

    The equipment used in the interference and two-rate flow tests carried out at the Cerro Prieto geothermal field during 1980 are described. The results of two interference tests are presented, one between wells M-110 and M-104, and the other between wells M-7 and Q-757. The data was interpreted using type curve matching analysis. Results of two-rate flow tests carried out in wells M-102 and M-7 are also discussed. A technique for making two-rate flow tests is proposed. This approach, which attempts to avoid the uncertainty of present flow-rate measurements, makes use of devices for direct measurements of separated water and steam. Conclusions based on the above interpretations and recommendations for future tests are presented.

  18. Ordenación de espacios naturales: Los Cerros de Escazú (Costa Rica)

    OpenAIRE

    Zúñiga Venegas, William

    2004-01-01

    La presente tesis doctoral se realizó en Costa Rica, país del Istmo Centroamericano que ocupa el tercer lugar en extensión entre los siete países que lo integran, con un territorio de 51.100km2 y una población de 3.824.593 habitantes. De su extensión terrestre, por lo menos el 26% (13 286km2), cuenta con algún tipo de figura legal de protección ya sea ambiental o de los recursos naturales. El área específica de la investigación se localiza en la Zona Protectora de los Cerros de Escazú; que c...

  19. Sand Negro

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård

    2016-01-01

    relationship. I see this as an impasse, or an ongoing, deep-seated form of asymmetric check-mate. I suggst that there is a shared framework for understanding that must exist as a premise for the kinds of conflict between majoritized and minoritized positions in question here. To address this, I implement...

  20. 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

  1. 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.

  2. 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…

  3. 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

  4. 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

  5. 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

  6. Mosasaurs (Reptilia) from the late Maastrichtian (Late Cretaceous) of northern Patagonia (Río Negro, Argentina)

    Science.gov (United States)

    Fernández, Marta; Martin, James; Casadío, Silvio

    2008-03-01

    A diverse assemblage of mosasaurs was recently recovered from the Jagüel Formation (late Maastrichtian) exposed at three localities of northern Patagonia (Río Negro, Argentina). Four taxa (three mosasaurines and a plioplatecarpine) have been identified, and three of these marine reptiles can be identified at lower taxonomic levels: Mosasaurus sp. aff. M. hoffmanni, Plioplatecarpus sp., and Prognathodon sp. These occurrences are significant because they represent the first diagnostic material at generic level exhumed from Patagonia and include one of the youngest mosasaurs found worldwide. One of the specimens described herein was found only 1.5 m below the Cretaceous/Tertiary boundary. Only mosasaurs from Antarctica found within a meter of the boundary are known to occur higher in the geologic section.

  7. HANTAVIRUS PULMONARY SYNDROME IN THE PROVINCE OF RIO NEGRO, ARGENTINA, 1993-1996

    Directory of Open Access Journals (Sweden)

    Gustavo CANTONI

    1997-07-01

    Full Text Available Early in 1995 the first case of Hantavirus Pulmonary Syndrome was serologically confirmed in El Bolsón (Province of Río Negro, Argentina, corresponding to the third outbreak reported in Argentina. A total of 26 cases of HPS related to the Andean region of Rio Negro Province, were reported from 1993 to 1996, 17 in El Bolsón, 4 in San Carlos de Bariloche, and 5 in Buenos Aires. The incidence rate was 5.03 x 100000 with a mortality rate of 51.85 x 100. The occurrence of cases was mainly seasonal, with a significantly greater number in the spring, and the persons affected mainly lived in urban or periurban areas. In four cases, the affected individuals were members of a couple, spouses or live-in contacts. Seven cases were Health workers (physicians, nurses or administrative staff. Twelve cases were related among them, due to an outbreak of 80 days. Two of them did not visit the Andean region. A total of 139 rodents were captured and seven of them, Olygoryzomys longicaudatus, were found to be serologically positive. The possibility of infection by contact with rodents or fecal matter is being analyzed and also hypothesis related with interhuman transmissionEm 1995, o primeiro caso de Síndrome Pulmonar pelo Hantavírus (HPS foi sorologicamente confirmado em El Bolsón (Província de Rio Negro, Argentina, correspondendo ao terceiro surto relatado na Argentina. Um total de 26 casos de HPS relacionados com a região Andina, Província de Rio Negro, foram relatados de 1993 a 1996, 17 em El Bolsón, 4 em São Carlos de Bariloche e 5 em Buenos Aires. O índice de incidência foi de 5,03 x 100.000 com índice de mortalidade de 51,85 x 100. A ocorrência de casos foi principalmente sasonal, com números significativamente maiores na primavera, e as pessoas afetadas viviam principalmente nas áreas urbanas e periurbanas. Em 4 casos, os indivíduos afetados eram membros de um casal, esposas ou viviam em contato. Sete casos eram trabalhadores da Saúde (m

  8. ‘COROJO 2006’: NUEVA VARIEDAD CUBANA DE TABACO NEGRO (Nicotiana tabacum L.

    Directory of Open Access Journals (Sweden)

    Vivaldo García Morejón

    2013-01-01

    Full Text Available En la Estación Experimental del Tabaco, de San Juan y Martínez, Pinar del Río durante la campaña tabacalera 2001-2002, se realizó un cruzamiento sexual con el objetivo de obtener una variedad de tabaco negro con mayor rendimiento que la comercial ‘Criollo 98’, resistente al moho azul ( Peronospora hyocyami de Bary, a la pata prieta ( Phytophthora parasitica Dast. var . Nicotianae Breda de Haan, al virus del mosaico del tabaco (VMT y a la necrosis ambiental. Después de cinco generaciones de autofecundación y selección por el método genealógico se obtuvieron siete variedades resistentes. El cruce originó la nueva variedad `Corojo 2006 ́ que superó a la `Criollo 98 ́.

  9. La novelística feminista de Carmen Laforet y el género negro

    Directory of Open Access Journals (Sweden)

    Johnson, Roberta

    2006-08-01

    Full Text Available In her five long novels, Carmen Laforet consistently attempted to find new narrative means of framing a feminist message. There exist studies of her use of the Bildungsroman, the Gothic, and Expressionism in Nada. This essay focuses on elements of detective fiction, especially the noir subgenre, in Laforet’s novelistic production, concentrating on Al volver la esquina published posthumously in 2004. The masculine protagonistnarrator moves in a world that is akin to those of North American noir films and novels in order to reveal his dilemma as a man of traditional Spanish masculinist values in a Spain that is beginning to experience the influence of other countries where gender roles are changing.En sus cinco novelas largas, Carmen Laforet intentaba consistentemente encontrar nuevos modos narrativos para enmarcar un mensaje feminista. Ya se ha estudiado su incorporación de la Bildungsroman, lo gótico y lo expresionista en Nada. Este ensayo se enfoca en los elementos de la novela detectivesca, sobre todo el subgénero negro, en la novelística de Laforet. Se concentra en Al volver la esquina publicada póstumamente en 2004, y en la que el protagonista- narrador masculino se mueve en un mundo que se asemeja a los del cine y novela negros norteamericanos, para revelar su dilema de hombre de valores tradicionales masculinistas en una España que está empezando a sentir la influencia de otros países donde los papeles de los géneros sexuales están cambiando.

  10. 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

  11. 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

  12. Report of the seismic activity at the Cerro Prieto B.C., Mexico, geothermal field during 1996; Reporte de la actividad sismica registrada en el campo geotermico de Cerro Prieto, B.C., Mexico, durante 1996

    Energy Technology Data Exchange (ETDEWEB)

    Escamilla Hernandez, Abelardo [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1997-05-01

    In February 1996 started the operation of the Seismic Network of Cerro Prieto Geothermal Field (RESICP). It is constituted by five digital stations with velocity sensors of three components and a natural period of one second. The network worked continuously until December 2, 1996. During this period, we located 270 events in the field area and its neighborhood, with coda-length magnitude 1Cerro Prieto Dos and Cerro Prieto Tres. The recorded activity is less than in Zone A, focal depths are between five and seven km, and the coda- length magnitude is 1Cerro Prieto volcano and to the NW of it. The activity was of swarm type mainly, and inside this zone was recorded the greater event for the region (M{sub c}=4.21, 30 August at 06:245 Universal Time), coda-length magnitude 1 Cerro Prieto (RESICP); consta de cinco estaciones de tipo digital, sensores de velocidad de tres componentes, y periodo natural de un segundo. Trabajo en forma ininterrumpida hasta el 2 de diciembre de 1996. Durante ese periodo se localizaron

  13. Yacimientos de Halloysita en Mamil Choique,provincia de Río Negro, Patagonia Halloysite deposits in Mamil Choique, provinceof Río Negro, Patagonia

    Directory of Open Access Journals (Sweden)

    Fernanda Cravero

    2009-11-01

    Full Text Available En la provincia de Río Negro, al norte de la localidadde Mamil Choique, se explotan depósitos minerales cuyo material secomercializacomo caolín. Mediante estudios mineralógicos se determinó que el mineralprincipal es halloysita-(10 Å acompañado por cantidades menores de esmectita ycristobalita, siendo el primer yacimiento en la Argentina de este mineral y unode los pocos en el mundo. La halloysita se presenta en cristales tubulares,cilíndricos, menores a 0,5 µm de largo y condiámetros menores a 0,2 µm. Laidentificación de la halloysita-(10Å, corroborada mediante la intercalacióncon formamida, fue además posible debido al cuidado puesto en el embalaje ytraslado de las muestras pues este mineral se deshidrataa temperatura ambientetransformándose en halloysita- (7 Å, la cual es fácilmente confundida concaolinita. El mineral se presenta en zonas alteradas, sobre rocas ignimbritas decomposición riolítica pertenecientes a la Formación Huitrera de edad eocena.Este proceso se caracteriza principalmente por una intensa lixiviación de loselementos alcalinos y alcalinos térreos, y un incremento en la concentraciónrelativa de alúmina. El origen de la alteración no se ha establecido conprecisión, pero la mineralogía simple, la ausencia de minerales característicosy de elementos minoritarios o trazas de ambientes epitermales, sumado a laexistencia de un clima templado húmedo a partir del Eoceno, permite suponer unaformación de tipo meteórico. La determinación de halloysita plantea la revisiónen la utilización de material de este depósito, ya que este mineral poseepropiedades muy diferentes a las de los otros minerales del grupo del caolín.A white material in RíoNegro Province, Patagonia, has been mined as kaolin. Through mineralogicalstudies, the main mineral has been identified as halloysite-(10 Å with minoramounts of smectite and cristobalite. Halloysite tubes and cylinders are about0.5 µm long and 0.2 µm in diameter

  14. Reflexiones en torno a la vulnerabilidad social y residencial de los asentamiento informales de los cerros de Valparaíso, Chile

    OpenAIRE

    Bailey, Christine; Zenteno, Elizabeth

    2015-01-01

    El incendio del pasado abril del 2014 ha abierto una serie de reflexiones respecto a las condiciones y riesgos que viven miles de familias de asentamientos informales de los cerros de Valparaíso. Aplicando una serie de entrevistas en profundidad a mujeres residentes en los cerros y quebradas, el estudio apunta a comprender las condiciones que las llevaron a habitar en aquellas zonas, visualizando el lento e infinito proceso de construcción de sus viviendas y asentamiento ...

  15. Corrosion in pipelines and well casings at the Cerro Prieto geothermal field, BC; Corrosion en tuberias de linea y de revestimiento de pozos del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A.; Canchola Felix, Ismael; Raygoza Flores, Joaquin; Mora Perez, Othon [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2009-07-15

    In the area called Poligono Hidalgo, inside the Cerro Prieto IV zone in the Cerro Prieto geothermal field, BC, corrosion has occurred in the last few years on well casings and pipelines used for geothermal fluids. Corrosion test results are presented here for pipes, type API L-80 and ASTM A-53 grade B, which were subjected to condensate from wells 403 and 424. These wells have thrown corroded material from their respective casings. With these data we pinpoint corrosive conditions in this field area and determine which pipes are adequate to case wells in similar chemical, production conditions to minimize adverse effects and extend the life of the well, allowing more efficient exploitation of the deepest production zones in the reservoir. [Spanish] En el campo geotermico de Cerro Prieto, BC, dentro del area del Poligono Hidalgo en el sector conocido como Cerro Prieto IV, algunos pozos han presentado en los ultimos anos desgastes en sus tuberias de revestimiento y en las tuberias de linea para el transporte del fluido geotermico. Se presentan resultados de pruebas de corrosion con tuberias tipo API L-80 y ASTM A-53 grado B al ser sometidas al condensado de los pozos 403 y 424, los cuales han estado arrojando material de sus respectivas tuberias de revestimiento. Con estos datos se pretende conocer las condiciones corrosivas de esa zona del campo y determinar cual seria la tuberia ideal a utilizar en pozos con condiciones quimicas de produccion semejantes a fin de minimizar este efecto adverso y prolongar la vida de los pozos, a la vez que se permita la explotacion eficiente de las zonas productoras mas profundas del yacimiento.

  16. Efeitos da ação antrópica sobre a hidrogeoquímica do rio Negro na orla de Manaus/AM The human action effects on the hydrogeochemistry of Negro river at the Manaus shoreline

    OpenAIRE

    Antônia Gomes Neta Pinto; Adriana Maria Coimbra Horbe; Maria do Socorro Rocha da Silva; Sebastião Atila Fonseca Miranda; Domitila Pascoaloto; Helder Manuel da Costa Santos

    2009-01-01

    O rio Negro, na orla de Manaus, recebe de seus tributários urbanos resíduos domésticos e industriais, cuja composição variada vem modificando as características naturais de suas águas. Com o intuito de avaliar o efeito da ação antrópica sobre o rio Negro foram coletadas amostras de água e analisadas as variáveis: pH, Eh, condutividade elétrica e alcalinidade (por potenciometria); oxigênio dissolvido (titrimetria); nitrogênio amoniacal e de nitritos (espectrofotometria); os cátions Ca, Mg, Na ...

  17. Efeitos da ação antrópica sobre a hidrogeoquímica do rio Negro na orla de Manaus/AM The human action effects on the hydrogeochemistry of Negro river at the Manaus shoreline

    Directory of Open Access Journals (Sweden)

    Antônia Gomes Neta Pinto

    2009-09-01

    Full Text Available O rio Negro, na orla de Manaus, recebe de seus tributários urbanos resíduos domésticos e industriais, cuja composição variada vem modificando as características naturais de suas águas. Com o intuito de avaliar o efeito da ação antrópica sobre o rio Negro foram coletadas amostras de água e analisadas as variáveis: pH, Eh, condutividade elétrica e alcalinidade (por potenciometria; oxigênio dissolvido (titrimetria; nitrogênio amoniacal e de nitritos (espectrofotometria; os cátions Ca, Mg, Na e K, e os metais Cd, Cu, Cr, Fe, Mn, Ni, Pb e Zn (por espectroscopia de absorção atômica - EAA. Os resultados obtidos para pH, condutividade, oxigênio dissolvido, nitrogênio amoniacal e nitritos mostram piora na qualidade da água do rio Negro, na foz dos igarapés São Raimundo (FISR e Educandos (FIE e a jusante destes (JIE, que são os dois maiores tributários urbanos e receptores de esgotos domésticos e efluentes industriais. Os metais predominaram na fase dissolvida e, a maior parte, está acima do limite máximo desejável, preconizado pelo ministério da saúde para águas destinadas ao abastecimento público, exceto cobre e zinco. O estudo mostrou que apesar da contribuição antrópica dos tributários urbanos, o rio Negro mantém, ainda, sua capacidade de diluir os poluentes, principalmente, no período de maior volume de água.The Negro river, on the shoreline of the city of Manaus, receives an input of industrial and domestic wastes from its urban tributaries, which varying composition has been changing the natural characteristics of its waters. Aiming to assess the effect of the human action on the Negro River water samples were collected, and pH, Eh, electric conductivity and alkalinity (by potentiometry; dissolved oxygen (titrimetry; ammonia and nitrite (spectrophotometry; cations Ca, Mg, Na and K, and the metals Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn (by atomic absorption spectroscopy, AAS were analyzed. The results for p

  18. Seroprevalence of Leptospira spp in cattle from Monte Negro municipality, western Amazon Prevalência de anticorpos anti-Leptospira spp em bovinos do município de Monte Negro, Amazônia Ocidental

    Directory of Open Access Journals (Sweden)

    Daniel M. Aguiar

    2006-06-01

    Full Text Available The prevalence of anti-Leptospira spp antibodies was investigated in 2,109 female cattle from 86 herds of Monte Negro municipality, Rondônia, Brazil. Sera samples were evaluated by Microscopic Agglutination Test against 24 leptospira serovars. Titers =100 for at least one of 24 leptospira serovars were detected in 1,114 cows (52.8% from 82 (95.3% herds. The adjusted overall prevalence for Monte Negro municipality was 53.9% (49-58.7%; CI: 95%. The most prevalent serovars were Hardjo (14.5%, Wolffi (12.3%, Shermani (10.8%, Patoc (7.9%, and Hebdomadis (6.1%. Other serovars worldwidely reported like Bratislava, Pomona and Grippotyphosa were detected in low levels.Foi investigada a prevalência de anticorpos anti-Leptospira spp em 2.109 vacas provenientes de 86 rebanhos do município de Monte Negro, Rondônia, Brasil. As amostras de soro sanguíneo foram avaliadas pelo Teste de Aglutinação Microscópica frente a 24 sorovares de leptospira. Títulos =100 para um ou mais sorovares foram detectados em 1.114 vacas (52,8% de 82 (95,3% rebanhos. A prevalência ajustada para o município de Monte Negro foi de 53,9% (I.C.: 95%; 49-58,7%. Os sorovares mais prevalentes foram Hardjo (14,5%, Wolffi (12,3%, Shermani (10,8%, Patoc (7,9% e Hebdomadis (6.1%. Outros sorovares mundialmente relatados como Bratislava, Pomona e Grippotyphosa foram pouco detectados.

  19. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae from Cerro Fatal on Santa Cruz Island.

    Directory of Open Access Journals (Sweden)

    Nikos Poulakakis

    Full Text Available The taxonomy of giant Galapagos tortoises (Chelonoidis spp. is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises.

  20. Nueva edad de la base del grupo Chubut en la mena uranífera Cerro Solo, provincia del Chubut

    Directory of Open Access Journals (Sweden)

    Nilda Marveggio

    2013-09-01

    Full Text Available En este trabajo se analizan las características litológicas de la roca hospedante de la mineralización de uranio del yacimiento Cerro Solo, que corresponde al miembro inferior de la Formación Los Adobes, unidad basal del Grupo Chubut en su sector norte. Se analiza la asociación de polen angiospérmico de allí recuperada, y en base a ese análisis, se establece una edad albiana temprana para la asociación polínica, que determina una edad más joven que la considerada hasta el momento para el inicio de la depositación de las sedimentitas del Grupo Chubut en el depocentro del yacimiento Cerro Solo.

  1. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: indicators of temperature distribution and fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.E.; Elders, W.A.

    1981-01-01

    Oxygen isotopic compositions have been measured in drill cuttings and core samples from more than 40 wells ranging in depth to more than 3.5 km in the Cerro Prieto geothermal field. Oxygen isotopic profiles of pore-filling calcites in sandstones appear to be a reliable measure of the recent equilibrium temperature distribution in the field before production began. From these data, a detailed, three-dimensional map has been developed, showing the equilibrium temperatures in the geothermal field. A mass balance calculation has been performed using measured /sup 18/O enrichment of the geothermal brine. This calculation implies an overall water; rock volume ratio of approximately 3:1 during the history of the Cerro Prieto system. Paleotemperatures different from the present thermal regime have been studied by examining coexisting mineral systems which exchanged their oxygen with the geothermal brines at different rates.

  2. Relationshipe Between Self-potential Anomalies and Hydraulic Flow In A Geothermal System: Application To Cerro-prieto, Baja California

    Science.gov (United States)

    Saracco, G.; Revil, A.; Pessel, M.

    The Cerro Prieto geothermal field is located in the alluvial plain of the Mexicali Valley, northern Baja California, Mexico, at about 35 km southeast of the city of Mexicali. The Cerro Prieto geothermal field is one of several high temperature water-dominated geothermal fields within the Salton Trough. We analyze here the self-potential distri- bution at the ground surface in order to determine the pattern of fluid flow in te sub- surface of this geothermal field. Various methods of analysis of self-potential anoma- lies are employed to reach this purpose. We use density probability tomography of monopolar and dipolar electrical sources and an Euler-type analysis. The hydraulic flow pattern found in this geothermal field is in agreement with that detemined from the heat flux inside the structure.

  3. Identidades en movimiento: familias chilenas en la fruticultura del Alto Valle de Río Negro, Argentina Identities in movement: chilean families in the fruit production of the Alto Valle de Río Negro, Argentina

    Directory of Open Access Journals (Sweden)

    Verónica Trpin

    2007-12-01

    Full Text Available Este artículo, basado en el trabajo de campo realizado en áreas rurales del Alto Valle de Río Negro, Argentina, desde el año 1999, tiene como propósito presentar las relaciones en las cuales se insertan hombres y mujeres chilenas que residen y trabajan en "chacras" destinadas a la producción frutícola. Las diferentes actividades en las chacras se organizan según el sexo y la edad, definiéndose una segmentación del mercado de trabajo en la que se ven involucrados los diferentes miembros de la familia. Como desarrollaré, ser trabajadores chilenos en la fruticultura del Alto Valle de Río Negro reproduce una identidad étnica y nacional en el seno de la cotidianeidad familiar y laboral.This article, based on field work conducted in rural areas of the Alto Valle de Río Negro, Argentina, from 1999 on, analyzes the relations in which Chilean men and women who reside and work in small farms destined to fruit production are inserted. The different activities in the small farms are organized according to sex and age, circumscribing a segment of the labor market in which different members of the family are involved. As I will demonstrate, to be a Chilean worker in the fruit growing region of the Alto Valle is to reproduce an ethnic and national identity through work routines mediated by family relations.

  4. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: Indicators of temperature distribution and fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.E.; Elders, W.A.

    1981-01-01

    Oxygen isotopic compositions have been measured in drill cuttings and core samples from more than 40 wells ranging in depth to more than 3.5 km in the Cerro Prieto geothermal field. Profiles of isotopic ratios versus sampling depths provide information on the three-dimensional distribution of temperature and fluid flow. These parameters also indicate variations in the history of hydrothermal processes in different areas of the geothermal field.

  5. Los marsupiales (Mammalia) del Mioceno Superior de la Formación Cerro Azul (Provincia de La Pampa, Argentina)

    OpenAIRE

    Visconti, G; Montalvo, C. I.; Goin, F J

    2000-01-01

    We describe the most complete South American marsupial association of Huayquerian Age (late Miocene). Specimens were recovered from several new localities of central and northern La Pampa province (central Argentina), at levels assignable to Cerro Azul Fm.: Bajo Giuliani, Quehué, Telén, El Guanaco, and Laguna Chillhué. Loessoid sediments studied from this formation are indicative of lacustrine deposits overlaid by eolian levels bearing evidences of pedogenesis. A study of these...

  6. ‘Looking at risk with both eyes’: health and safety in the Cerro Rico of Potosí (Bolivia)

    OpenAIRE

    Lopez-Trueba, Mei

    2014-01-01

    This thesis is concerned with core assumptions and practices in dominant approaches to Occupational Health and Safety (hereafter, OHS). I critically evaluate these through an anthropological exploration of the everyday perceptions, experiences and practices related to OHS risks amongst the cooperative miners employed in the Cerro Rico of Potosi (Bolivian Highlands). Drawing on 17 months of ethnographic fieldwork conducted between 2009 and 2011, the thesis examines the lives and livelihood...

  7. Xenoliths of Cerro las Mercedes, Costa Rica: a Geochemical Record of Arc History?

    Science.gov (United States)

    Lindsay, F. N.; Gazel, E.; Herzberg, C. T.; Carr, M. J.; Feigenson, M. D.

    2006-12-01

    Over 70 ultramafic xenoliths, many with diameters of at least 3cm, open a window into the mantle beneath Cerro las Mercedes, Costa Rica. This quaternary vent is 70km behind the active volcanic front and near the northern boundary of the Caribbean Plateau. Both xenoliths and host lava remain well preserved in spite of substantial soil development in a rain forest environment. We analyzed the host lava and a subset of 30 rocks for bulk and mineral chemistry, which include both peridotite and pyroxenite populations. The host rock is Plio-Quaternary potassic alkaline basalt; depleted in SiO2 and Al2O3 and enriched in MgO and P2O5 relative to both present day and Miocene volcanics. In terms of trace elements, the host basalt has enriched LREEs and relative depletion of HFSEs, typical of island-arc basalt, both present and past. The coarse-grained pyroxenites have trace element chemistry akin to the volcanic front lavas of Costa Rica, although they are closer to chondritic values. Truly, they are more similar to basalts from Sarapiquí Miocene arc than to present day volcanic front basalts. Although there is enrichment in incompatible elements such as Ba and U and depletions in HFSEs, common in island arc basalts, the pyroxenites have a strong positive Pb anomaly that is characteristic only of the Miocene arc, not present day lavas. We interpret the pyroxenites as cumulates. The peridotite population includes dunites, spinel lherzolites and lherzolites. These rocks have Mg-numbers ranging from 87 to 92 and Cr-numbers ranging from 6 to 61. Whole rock geochemistry indicates that the peridotite xenoliths are fragments of mantle associated with the western Caribbean Plateau. SiO2, FeO, Al2O3 and MgO contents of several Cerro Mercedes peridotites are similar to those expected of hot residues that would form in a plume environment. Trace elements reveal some samples with enrichment of Ba and U, and depletion in Nb and Ta indicating variable extents of melt-rock reaction and

  8. Luis de Molina y la esclavitud de los negros africanos en el siglo XVI. Principios doctrinales y conclusiones

    Directory of Open Access Journals (Sweden)

    García Añoveros, Jesús María

    2000-08-01

    Full Text Available One of the most important consequences of Portuguese discoveries was the black slavery business. A most reputed theologist and jurist of the time, Juan de Molina, who had a first-hand knowledge of the subject, made a thorough analysis of the justness of slavery from a Theology and Law perspective, while showing himself opposed to the same. His doctrine set basis for future thought and he must be considered as the first great tratadist on black slavery.

    Una de las consecuencias más importantes de los descubrimientos portugueses en África fue el negocio de los esclavos negros. Luis de Molina, uno de los teólogos y juristas más importantes de su época y con un gran conocimiento del asunto, trató el tema de la licitud de los esclavos negros en amplitud, analizándolo desde la perspectiva de la teología y del derecho, sin omitir su opinión personal contraria a dicha esclavitud. Su doctrina creó escuela y debe ser considerado como el primer gran tratadista de la esclavitud de los negros.

  9. 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

  10. 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.

  11. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease-resistance genes in the common bean cultivar Ouro Negro

    OpenAIRE

    Gonçalves-Vidigal, MC; Cruz, AS; Lacanallo, GF; Vidigal Filho, PS; Sousa, LL; Pacheco, CMNA; McClean, P.; Gepts, P.; Pastor-Corrales, MA

    2013-01-01

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean (Phaseolus vulgaris L.). Ouro Negro is a highly productive common bean cultivar, which contains the Co-10 and Phg-ON genes for resistance to ANT and ALS, respectively. In this study, we performed a genetic co-segregation analysis of resistance to ANT and ALS using an F2 population from the Rudá × Ouro Negro cross and the F2:3 families from the AND 277 × Ouro Negro cross. Ouro Negro is resistant to races 7 an...

  12. 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...

  13. 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...

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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 ...

  1. 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...

  2. 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...

  3. Degradabilidad ruminal de la planta de sorgo negro forrajero (sorghum almum en diferentes etapas de crecimiento

    Directory of Open Access Journals (Sweden)

    Carlos Boschini

    2001-01-01

    Full Text Available Degradabilidad ruminal de la planta de sorgo negro forrajero (Sorghum almum en diferentes etapas de crecimiento. El trabajo se llevó a cabo con el propósito de conocer la degradabilidad ruminal de la materia seca del sorgo negro forrajero, cultivado en una zona alta de Costa Rica. Se tomaron muestras en diferentes etapas de crecimiento de la planta. El estudio se realizó en la Estación Experimental "Alfredo Volio Mata" de la Universidad de Costa Rica. El cultivo fue sembrado con 18 kg/ha de semilla (88% semilla pura germinable, distribuida a chorro continuo en surcos distanciados a 70 cm. Se fertilizó con 244 kg de la fórmula comercial 10-30-10 (N2, P2O5, K2O y a las seis semanas se aplicaron 45,5 kg/ha de nitrógeno. El primer muestreo se realizó a los 24 días de edad y los siguientes, cada 14 días, hasta los 150 días. Se determinó la degradabilidad potencial de la materia seca en las hojas, tallos, panojas. La degradabilidad potencial de la planta entera disminuyó de 90 a 75% conforme aumentó la edad durante los primeros 94 días. En el tallo, la fracción soluble disminuyó de 32 a 23%, mientras que la hoja bajó de 30 a 16%. La fracción degradable en el tallo disminuy ó de 57 a 46% con el desarrollo de la planta, en tanto que en la hoja aumentó de 56 a 69%. La velocidad de degradaci ón del tallo fue de 4,7 %/h a los 52 días y en la hoja de 8,6 %/h. De 66 a 94 días fue de 2,6%/h en el tallo y en la hoja de 5,4 %/h, 3,3 %/h y 3,8 %/h a los 66, 80 y 94 días, respectivamente

  4. 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

  5. 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.

  6. 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.

  7. A Climatology of Ripple Instabilities in the OH Airglow at Cerro Pachon, Chile

    Science.gov (United States)

    Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.; Rudy, R. J.

    2015-12-01

    Airglow imaging provides a unique means by which to study many wave-related phenomena in the 80 to 100 km altitude regime. Observations reveal quasi-monochromatic disturbances associated with atmospheric gravity waves (AGWs) as well as small-scale instabilities often called ripples. Ripples are wavelike features that resemble AGWs in appearance, but have short horizontal wavelengths (Corporation's Nightglow Imager (ANI) is located at the Andes Lidar Observatory near the crest of Cerro Pachon, Chile. ANI observes nighttime OH emission (near 1.6 microns) every 2 seconds over an approximate 73 degree field of view, which allows the study of AGW and ripple features over very short temporal and spatial scales. An automated wave detection algorithm is used to identify ripple and quasi monochromatic wave features in the ANI data. Ripples are characterized by their wavelength, orientation, drift speed and location in the image. Quasi-monochromatic waves are quantified by wavelength, wave period and propagation direction. We present a climatology of ripple instabilities at Chile, including comparisons to the background quasi-monochromatic wave field. Lidar and radar data are used to determine the background wind and temperatures, which allows comparisons between ripple observations and evanescent regions and potentially unstable regions identified by Richardson number.

  8. Research Experiences for Undergraduates at Cerro Tololo Inter-American Observatory

    Science.gov (United States)

    Hoard, D. W.; Smith, R. C.

    2000-12-01

    Each year, Cerro Tololo Inter-American Observatory (CTIO), located in La Serena, Chile, hosts a Research Experiences for Undergraduates (REU) Program funded by the National Science Foundation. In general, REU programs bring a group of undergraduate students to the host institute for 10 weeks, where they are teamed-up with staff members to perform research projects. Unlike REU programs at other U.S. institutions, the CTIO program takes place outside the United States and during the southern summer/northern winter months of January--March. This offers students not only a chance to perform research and participate in the day-to-day life at a major astronomical observatory, but also provides a unique exposure to a foreign culture and an option for students who can take advantage of a non-traditional work experience during the academic year. CTIO REU students also benefit from interaction with their Chilean counterparts participating in the Prácticas de Investigación en Astronomía, an REU-like program operated by CTIO for Chilean undergraduates. Since 1995, CTIO has hosted 20 REU students (with 4 more coming in 2001). Twenty (and counting) publications have resulted from CTIO REU projects. In addition, since 1999, 100% of the CTIO REU students have presented the results of their research projects at meetings of the American Astronomical Society. We present here an overview of the REU program at CTIO.

  9. Characterization of the sodium layer at Cerro Pachon, and impact on laser guide star performance

    CERN Document Server

    Neichel, Benoit; Callingham, Joseph; Rigaut, Francois; Winge, Claudia; Trancho, Gelys; 10.1093/mnras/sts631

    2013-01-01

    Detailed knowledge of the mesopheric sodium layer characteristics is crucial to estimate and optimize the performance of Laser Guide Star (LGS) assisted Adaptive Optics (AO) systems. In this paper, we present an analysis of two sets of data on the mesospheric sodium layer. The first set comes from a laser experiment that was carried out at Cerro Tololo to monitor the abundance and altitude of the mesospheric sodium in 2001, during six runs covering a period of one year. This data is used to derive the mesospheric sodium column density, the sodium layer thickness and the temporal behavior of the sodium layer mean altitude. The second set of data was gathered during the first year of the Gemini MCAO System (GeMS) commissioning and operations. GeMS uses five LGS to measure and compensate for atmospheric distortions. Analysis of the LGS wavefront sensor data provides information about the sodium photon return and the spot elongation seen by the WFS. All these parameters show large variations on a yearly, nightly ...

  10. Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

    Science.gov (United States)

    Pastrana-Corral, M A; Wakida, F T; García-Flores, E; Rodriguez-Mendivil, D D; Quiñonez-Plaza, A; Piñon-Colin, T D J

    2016-08-01

    Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area. PMID:27418073

  11. New mammalian records in the Parque Nacional Cerros de Amotape, northwestern Peru

    Directory of Open Access Journals (Sweden)

    Cindy M. Hurtado

    2015-04-01

    Full Text Available The Pacific Tropical Rainforest and Equatorial Dry Forest are found only in southern Ecuador and northern Peru, and are among the most poorly known ecosystems of South America. Even though these forests are protected in Parque Nacional Cerros de Amotape (PNCA, they are threatened by fragmentation because of farming and agriculture. The aim of this study was to determine the medium and large mammalian species richness, using transect census, camera trapping, and specimen bone collection. Nine transects were established and 21 camera trap stations were placed along 16 km2 in three localities of PNCA, from August 2012 to April 2013. Total sampling effort was 215 km of transects and 4077 camera-days. We documented 22 species; including 17 with camera trapping, 11 with transect census, and 10 with specimen collection.  Camera traps were the most effective method, and four species (Dasyprocta punctata, Cuniculus paca, Leopardus wiedii and Puma concolor were documented only with this method. This comprised the first Peruvian record for Dasyprocta punctata, and the first record for the western slope of the Peruvian Andes for Cuniculus paca. Also, both specimen collections and sightings confirm the presence of Potos flavus, first record in the western slope of the Peruvian Andes. Panthera onca, Tremarctos ornatus and Saimiri sciureus are considered locally extinct, while several species are in need of further research. We highlight the importance of the high diversity of this rainforests and encourage local authorities to give the area the highest priority in conservation.

  12. Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

    CERN Document Server

    Lascaux, Franck; Fini, Luca

    2015-01-01

    This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...

  13. Monitoring the atmospheric throughput at Cerro Tololo Inter-American Observatory with aTmCam

    CERN Document Server

    Li, Ting; Marshall, J L; Nagasawa, D Q; Carona, D W; Boada, S

    2014-01-01

    We have built an Atmospheric Transmission Monitoring Camera (aTmCam), which consists of four telescopes and detectors each with a narrow-band filter that monitors the brightness of suitable standard stars. Each narrowband filter is selected to monitor a different wavelength region of the atmospheric transmission, including regions dominated by the precipitable water vapor and aerosol optical depth. The colors of the stars are measured by this multi narrow-band imager system simultaneously. The measured colors, a model of the observed star, and the measured throughput of the system can be used to derive the atmospheric transmission of a site on sub-minute time scales. We deployed such a system to the Cerro Tololo Inter-American Observatory (CTIO) and executed two one-month-long observing campaigns in Oct-Nov 2012 and Sept-Oct 2013. We have determined the time and angular scales of variations in the atmospheric transmission above CTIO during these observing runs. We also compared our results with those from a G...

  14. Measurements of air contaminants during the Cerro Grande fire at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Eberhart, Craig

    2010-08-01

    Ambient air sampling for radioactive air contaminants was continued throughout the Cerro Grande fire that burned part of Los Alamos National Laboratory. During the fire, samples were collected more frequently than normal because buildup of smoke particles on the filters was decreasing the air flow. Overall, actual sampling time was 96% of the total possible sampling time for the May 2000 samples. To evaluate potential human exposure to air contaminants, the samples were analyzed as soon as possible and for additional specific radionuclides. Analyses showed that the smoke from the fire included resuspended radon decay products that had been accumulating for many years on the vegetation and the forest floor that burned. Concentrations of plutonium, americium, and depleted uranium were also measurable, but at locations and concentrations comparable to non-fire periods. A continuous particulate matter sampler measured concentrations that exceeded the National Ambient Air Quality Standard for PM-10 (particles less than 10 micrometers in diameter). These high concentrations were caused by smoke from the fire when it was close to the sampler.

  15. 3-cerro y 4-mundo: los números del banquete en las ofrendas quechuas

    Directory of Open Access Journals (Sweden)

    David Lorente Fernández

    2010-12-01

    Full Text Available Las ofrendas quechuas del sur del Perú son platos alimenticios, banquetes destinados principalmente a la pachamama y los apus, pero también elaborados sistemas matemáticos regidos por operaciones sofisticadas. Sirviéndose de dos números fundamentales, el 3 y el 4, los especialistas rituales son capaces de transmitir mensajes polisémicos. Mediante el número 3 aglutinan clientes, parajes y cerros, en suma, «personas» capaces de interactuar entre sí. El 3 aparece en los k’intus de hojas de coca y en las oraciones que se recitan durante el proceso de realizar la ofrenda. Por el contrario, el número 4 no indica relaciones sino formas espaciales: es un operador geométrico que unifica la servilleta ceremonial (unk’uña, el papel envoltorio y el paquete acabado para representar las cuatro direcciones del mundo y hacer de la ofrenda un mundo en miniatura. Gracias a los dos números el ritualista puede recrear el cosmos, establecer convenios con los dioses y definir nuevas situaciones favorables para la vida de sus clientes.

  16. Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

    Science.gov (United States)

    Pastrana-Corral, M A; Wakida, F T; García-Flores, E; Rodriguez-Mendivil, D D; Quiñonez-Plaza, A; Piñon-Colin, T D J

    2016-08-01

    Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area.

  17. Model of the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1982-08-10

    Earlier studies at Cerro Prieto by UCR have led to the development of a qualitative model for field flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modelling of heat and mass transfer in the system in this undisturbed state. A two-dimensional model assumes that the heat sources were a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compiling various information on the physical properties of the reservoir, the enthalpy contained in two 1cm thick section across the reservoir orthogonal to each other was calculated. Next various shapes, sizes and depths for the intrusion as initial conditions and boundary conditions for the calculation of heat transfer were considered. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4km wide emplaced at a depth of 5km some 30,000 to 50,000 years ago, providing heat to the geothermal system. Numerical modelling is still in progress. Although none of the models so far computed may be a perfect match for the thermal history of the reservoir, they all indicate that the intrusive heat source is young, close and large.

  18. Gas chemistry and thermometry of the Cerro Prieto, Mexico, geothermal field

    Science.gov (United States)

    Nehring, N.L.; D'Amore, F.

    1984-01-01

    Gas compositions of Cerro Prieto wells in 1977 reflected strong boiling in the reservoir around wells M-20 and M-25. This boiling zone appeared to be collapsing in 1982 when a number of wells in this area of the field were shut-in. In 1977 and 1982, gas compositions also showed boiling zones corresponding to faults H and L postulated by Halfman et al. (1982). Four gas geothermometers were applied, based on reservoir equilibria and calculated fugacities. The Fisher - Tropsch reaction predicted high temperatures and appeared to re-equilibrate slowly, whereas the H2S reaction predicted low temperatures and appeared to re-equilibrate rapidly. Hydrogen and NH3 reactions were intermediate. Like gas compositions, the geothermometers reflected reservoir processes, such as boiling. Surface gas compositions are related to well compositions, but contain large concentrations of N2 originating from air dissolved in groundwater. The groundwater appears to originate in the east and flow over the production field before mixing with reservoir gases near the surface. ?? 1984.

  19. Intersecting faults and sandstone stratigraphy at the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Vonder Haar, S.; Howard, J.H.

    1980-02-01

    The northwest-southeast trending Cerro Prieto fault is part of a major regional lineament that extends into Sonaro and has characteristics of both a wrench fault and an oceanic transform fault. The distribution of lithologies and temperature within the field was studied by comparing data from well cuttings, cores, well logs, and geochemical analyses. Across the earliest developed portion of the field, in particular along a 1.25-km northeast-southwest section from well M-9 to M-10, interesting correlations emerge that indicate a relationship among lithology, microfracturing, and temperature distribution. In the upper portion of Reservoir A of this stratigraphic section, between 1200 and 1400 m, the percentage of sandstones ranges from 20 to 55. Temperatures are 225/sup 0/ to 275/sup 0/C based on well logs, calcite isotope maxima, and Na-K-Ca indices. The study shows that an isothermal high in this vicinity corresponds to the lowest total percentage of sandstones. Scanning electron microphotographs of well cores and cuttings from sandstone and shale units reveal clogging, mineral dissolution, and mineral precipitation along microfractures. The working hypothesis is that these sandy shale and siltstone facies are most amenable to increased microfracturing and, in turn, such microfracturing allows for higher temperature fluid to rise to shallower depths in the reservoir.

  20. The Final Days of Paracas in Cerro del Gentil, Chincha Valley, Peru.

    Science.gov (United States)

    Tantaleán, Henry; Stanish, Charles; Rodríguez, Alexis; Pérez, Kelita

    2016-01-01

    This article describes and analyzes a highly significant archaeological context discovered in a late Paracas (400-200 BCE) sunken patio in the monumental platform mound of Cerro Gentil, located in the Chincha Valley, Peru. This patio area was used for several centuries for ritual activities, including large-scale feasting and other public gatherings. At one point late in this historical sequence people deposited a great deal of objects in what is demonstrably a single historical event. This was quickly followed by a series of minor events stratigraphically immediately above this larger event. This entire ritual process included the consumption of liquids and food, and involved the offering of whole pottery, pottery fragments, botanical remains, bone, lithics, baskets, pyro-engraved gourds, mummies, and other objects. We interpret these events as an "abandonment ceremony" or "termination ritual" during the late Paracas period, one that may have lasted for weeks or even months. The subsequent Topará occupation at the site (ca. 200 BCE- AD 100) involved the architectural enhancement of the mound area, but the pattern of use of the patio itself ended. Such a termination ritual signals a reorganization in the regional political structure of Paracas society. PMID:27144824

  1. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory

    International Nuclear Information System (INIS)

    Results from optical and infrared observations of SN 1987A obtained at Cerro Tololo Inter-American Observatory over the first seven months since core collapse are reviewed. Around 130 days after outburst, the bolometric light curve began to smoothly decline at a rate of ∼ 0.01 mag day-1, providing dramatic confirmation of the prediction that radioactivity had powered the optical display after the first month./ the peculiar color changes are kinks observed beginning on the 25th day probably signaled the initial release of trapped energy from mass 56 material. The bolometric luminosity of SN 1987A was unusually low at first, but reached a value more typical of other type II supernovae by the time that the final exponential decline had begun. Over much of the period covered by these observations, the optical and infrared spectra were characterized by strong absorption lines of Ba II and Sr II. Comparison with the spectra of other type II supernovae at similar stages of evolution supports the suggestion that s-processed elements were enriched in the hydrogen envelope of the progenitor, Sanduleak - 69 degrees 202

  2. La crisis del fletan negro. Una perspectiva desde la prensa canadiense

    Directory of Open Access Journals (Sweden)

    Santos Solla, Xosé Manuel

    2001-03-01

    Full Text Available La crisis del fletan negro supuso que durante al menos mes y medio todos los medios de comunicación de España y Canadá centrasen su atención en este tema. Que un pez tan desconocido fuese el centro de un conflicto de esas dimensiones es algo que realmente llamó la atención. Sin embargo, detrás de todo este asunto había algo más que la disputa por el reparto de unas pocas miles de toneladas. En este trabajo recogemos las informaciones de cinco periódicos representativos de Canadá, y con el apoyo de otras publicaciones y de encuestas realizadas en el propio país norteamericano, ofrecemos una visión particular del conflicto, deteniéndonos especialmente en la imagen que se transmitió a través de la prensa de los contendientes: Canadá y la Unión Europea; y dentro de ella España.

  3. Modelo An\\'alogo Ac\\'ustico ao Buraco Negro de Schwarzschild

    CERN Document Server

    Toniato, Júnior Diniz

    2011-01-01

    Um fluido em movimento pode agir sobre o som da mesma forma que os espa\\c{c}o-tempos curvos podem influenciar na trajet\\'oria da luz na relatividade geral. Com isso, pode-se descrever a propaga\\c{c}\\~ao dessas ondas sonoras atrav\\'es de uma m\\'etrica efetiva, sob a qual elas seguir\\~ao geod\\'esicas nulas. Esta disserta\\c{c}\\~ao faz uma revis\\~ao destes estudos concentrando-se em uma analogia ac\\'ustica para um buraco negro de Schwarzschild, demonstrando suas vantagens e limita\\c{c}\\~oes quando aplicada para o estudo da teoria de Hawking. A fluid in moviment can act on the sound the same way that curved space-time can influence on light trajectory in the general relativity. So, one can describe the propagation these sound waves through an effective metric, under wich they will follow null geodesics. This thesis makes a review of these studies focusing in an analogy to Schwarzschild black hole using an acoustic system, showing its advantages and limitations when applied in the study of Hawking's theory.

  4. [Aquatic Ecological Index based on freshwater (ICE(RN-MAE)) for the Rio Negro watershed, Colombia].

    Science.gov (United States)

    Forero, Laura Cristina; Longo, Magnolia; John Jairo, Ramirez; Guillermo, Chalar

    2014-04-01

    Aquatic Ecological Index based on freshwater (ICE(RN-MAE)) for the Rio Negro watershed, Colombia. Available indices to assess the ecological status of rivers in Colombia are mostly based on subjective hypotheses about macroinvertebrate tolerance to pollution, which have important limitations. Here we present the application of a method to establish an index of ecological quality for lotic systems in Colombia. The index, based on macroinvertebrate abundance and physicochemical variables, was developed as an alternative to the BMWP-Col index. The method consists on determining an environmental gradient from correlations between physicochemical variables and abundance. The scores obtained in each sampling point are used in a standardized correlation for a model of weighted averages (WA). In the WA model abundances are also weighted to estimate the optimum and tolerance values of each taxon; using this information we estimated the index of ecological quality based also on macroinvertebrate (ICE(RN-MAE)) abundance in each sampling site. Subsequently, we classified all sites using the index and concentrations of total phosphorus (TP) in a cluster analysis. Using TP and ICE(RN-MAE), mean, maximum, minimum and standard deviation, we defined threshold values corresponding to three categories of ecological status: good, fair and critical. PMID:25189081

  5. Fishery of the short-necked clam Paphia undulata in Southern Negros Occidental, Central Philippines

    Directory of Open Access Journals (Sweden)

    Karen A. Villarta

    2010-06-01

    Full Text Available This study documents the fishery of the short-necked clam Paphia undulata in coastal waters of southern Negros Occidental. Catch and effort estimates were determined based on daily records of compressor divers gathered between February-July 2008 in Himamaylan City and July 2008-May 2009 in the town of Hinigaran. Fishing and marketing practices in both areas were also documented and population biology information noted.Compared to earlier conditions, present fishing patterns show a worsened stage of overexploitation primarily characterized by collection of predominantly small and immature (mostly <45 mm shell lengths sizes. Intensity/duration and location of fishing also varied due to both abundance and demand factors.The difference in sizes of clams and the varying fishing durations in each area suggest a non-uniform pattern of settlement resulting most likely from differential larval recruitment, the likely factors causing the local boom and bust fishery. The larger and long term extent of the effect of these factors can only be further investigated by parallel 2-3 year fishery-dependent and -independent surveys

  6. 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 ...

  7. Ocorrência do molusco asiático Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae no baixo rio Negro, Amazônia central Occurrence of the Asian mollusc Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae in the lower Rio Negro, Central Amazon Region, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Mansur Pimpão

    2008-01-01

    Full Text Available O rio Negro é um dos maiores afluentes do rio Amazonas, mas poucos moluscos foram registrados até o momento para aquele rio, representados apenas por gastrópodes. Foi registrada a presença do molusco bivalve exótico Corbicula fluminea na margem esquerda do baixo rio Negro, no lago do Tupé e no Catalão - margem direita do rio Negro, todas localidades no município de Manaus, Brasil. O registro foi realizado por meio da coleta de conchas e espécimes vivos. É o primeiro registro de C. fluminea para o estado do Amazonas e Amazônia central.The Rio Negro is one of the biggest Rio Amazonas tributaries. Few molluscs have been registered to that river yet, represented only by gastropods. It is reported the occurrence of the exotic bivalve mollusc Corbicula fluminea in left bank margin of Rio Negro, Lago do Tupé and Catalão - right bank margin of Rio Negro, all localities in the municipality of Manaus, Brazil. The species is recorded by a collection of shells and specimens alive. This is the first occurrence of C. fluminea in the Amazon State and Central Amazon.

  8. Criteria to determine the depth of the production interval in wells of the Cerro Prieto geothermal field, Mexico; Criterios para determinar la profundidad del intervalo productor en pozos del campo geotermico de Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Leon Vivar, Jesus Saul de [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: jesus.deleon@cfe.gob.mx

    2006-07-15

    Ways to select the depth of the production interval or to complete wells in the Cerro Prieto geothermal field have changed during the development of the field. From 1961 when drilling began to the middle of 2005, a total of 325 wells were drilled. The paper compares the approaches used in the past with those of the last ten years. The Cerro Prieto system has been classified as being of liquid-dominated and high-temperature. Today, after 33 years of commercial exploitation, it has experienced a series of thermal and geochemical fluid changes making it necessary to modify the ways to select the depth of the well production intervals, according to the observed behavior of the reservoir. The new criteria include the thermal approach, the geological approach, the geochemical approach and a comparative approach with neighboring wells. If most of these criteria are interpreted correctly, the success of a well is ensured. [Spanish] Los criterios para seleccionar la profundidad del intervalo productor o la terminacion de los pozos en el campo geotermico de Cerro Prieto han cambiado durante el desarrollo del mismo. De 1961, cuando se perforaron los primeros pozos, hasta mediados del 2005 se han perforado un total de 325 pozos. En el presente articulo se hara una breve revision de cuales han sido los criterios usados en el pasado y los que se han venido empleando en los ultimos diez anos. El yacimiento de Cerro Prieto ha sido clasificado como de liquido dominante, de alta temperatura, pero actualmente, despues de 33 anos de explotacion comercial, ha sufrido una serie de cambios termicos y geoquimicos en sus fluidos, por lo que ha sido necesario modificar los criterios para seleccionar la profundidad del intervalo productor de los pozos de acuerdo al comportamiento observado en el yacimiento. Los criterios actuales se dividen en cuatro: 1. Criterio termico, 2. Criterio geologico, 3. Criterio geoquimico y 4. Criterio comparativo de los pozos vecinos. Cuando la mayoria de estos

  9. Evolution of the CP-I sector of the Cerro Prieto geothermal reservoir, BC, and exploitation alternatives; Evolucion del sector CP-I del yacimiento geotermico de Cerro Prieto, BC, y alternativas de explotacion

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez, Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2010-01-15

    After 35 years of exploitation of the CP-I (Cerro Prieto I) sector of the Cerro Prieto geothermal field, its thermal conditions have been declined substantially; the number of production wells is reduced and exploitation has been abandoned in some zones. However with a binary cycle, it is still possible to generate electricity from the remaining reservoir energy. To do so, one needs to know a detailed reservoir history of the sector, identifying the best potential strata to be assessed. In this paper, the CP-I reservoir evolution is presented and its exploitation and main reservoir characteristics -which play important roles- are identified. The CP-I zones offering the best conditions for binary cycle exploitation are identified. Exploiting partially abandoned reservoir sections is crucial for the future of the field. If such sections can be made to produce, this will help reduce the progressive steam-production decline in the occurring since production began. The production decline had been mitigated by a large area available for drilling replacement production wells, but such an area is limited now, due to the vast number of operating wells. [Spanish] Despues de 35 anos de explotacion del yacimiento en el sector de CP-I (Cerro Prieto I) del campo geotermico de Cerro Prieto, BC, sus condiciones termicas han declinado considerablemente, por lo que el numero de pozos productores ha disminuido, dejando algunas zonas abandonadas a la explotacion. Sin embargo, aun es posible aprovechar la energia que contiene este sector del yacimiento para la generacion de electricidad mediante ciclo binario. Para ello primeramente se debe conocer en detalle cual ha sido la evolucion del yacimiento en este sector, identificando los estratos de mejor potencial para evaluarlos posteriormente. En este estudio se presenta la evolucion del yacimiento de CP-I como respuesta a su explotacion, identificando las principales caracteristicas del yacimiento que determinan su comportamiento. Asi

  10. Update of the basement model of the Cerro Prieto, B. C., geothermal field, Mexico; Actualizacion del modelo del basamento en el campo geotermico de Cerro Prieto, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lopez, Macario [Residencia General de Cerro Prieto, Comision Federal de Electricidad, Mexicali, Baja California (Mexico)

    1999-04-01

    With the aim to actualize the basement model of the Cerro Prieto Geothermal Field, a gravity interpretation has been held. We modeled in 2.5 D, nine profiles traced over the Bouguer anomaly map. Well data concerning lithology and density changes were used to fit the gravity models. Results of this work confirm that the geometry of the basement of Cerro Prieto, corresponds to a structural sequence. From west to east it starts as a big depression, continues with a strong uplift of the basement in the middle sector and finally deepens eastward in steps. The basement model proposed in the present work, defines a similar trend to that established by Fonseca y Razo (1980), but there are differences in basement depth in some areas. In the present model we interpret basement depths between 200 and 400 m deeper than in previous models to the south and northwest of the actual exploitation zone. [Spanish] Con el fin de actualizar el modelo del basamento en el Campo Geotermico de Cerro Prieto, se realizo una reinterpretacion gravimetrica, modelando en 2.5 D, 9 perfiles trazados sobre el mapa de anomalia de Bouguer. Utilizando la informacion litologica obtenida a traves de numerosas perforaciones profundas, se hicieron coincidir, dentro de los mofelos gravimetricos, las principales variaciones litologicas con cambios en la densidad. Los resultados de este trabajo reiteran que la geometria del basamento del Campo de Cerro Prieto, vista de W a E, corresponde con una secuencia estructural que se inicia con una gran depresion en el W, continua con un fuerte levantamiento y finalmente se extiende con una tendencia a profundizarse hacia el E de forma escalonada. El modelo de basamento derivado del presente trabajo, define una tendencia muy similar al modelo de basamento establecido (Fonseca y Razo, 1980), pero difiere en cuanto a la profundidad en algunos sectores del campo. En el actual trabajo se interpreta una profundidad entre 200 y 400 m mayor hacia el sur y noroeste de la

  11. 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.…

  12. 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…

  13. 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...

  14. 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).

  15. 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.

  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. Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

    Science.gov (United States)

    Casteller, A.; Christen, M.; Villalba, R.; Martínez, H.; Stöckli, V.; Leiva, J. C.; Bartelt, P.

    2008-05-01

    The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1) to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2) to highlight the potential of textit{Nothofagus pumilio} tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

  18. Regional and local networks of horizontal control, Cerro Prieto geothermal area

    Science.gov (United States)

    Massey, B.L.

    1979-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley 30 km southeast of Mexicali, Baja California, is probably deforming due to (1) the extraction of large volumes of steam and hot water, and (2) active tectonism. Two networks of precise horizontal control were established in Mexicali Valley by the U.S. Geological Survey in 1977 - 1978 to measure both types of movement as they occur. These networks consisted of (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from survey stations on an existing U.S. Geological Survey crustal-strain network north of the international border, and (2) a local net tied to stations in the regional net and encompassing the area of present and planned geothermal production. Survey lines in this net were selected to span areas of probable ground-surface movements in and around the geothermal area. Electronic distance measuring (EDM) instruments, operating with a modulated laser beam, were used to measure the distances between stations in both networks. The regional net was run using a highly precise long-range EDM instrument, helicopters for transportation of men and equipment to inaccessible stations on mountain peaks, and a fixed wing airplane flying along the line of sight. Precision of measurements with this complex long-range system approached 0-2 ppm of line length. The local net was measured with a medium-range EDM instrument requiring minimal ancillary equipment. Precision of measurements with this less complex system approached 3 ppm for the shorter line lengths. The detection and analysis of ground-surface movements resulting from tectonic strains or induced by geothermal fluid withdrawal is dependent on subsequent resurveys of these networks. ?? 1979.

  19. Carbon-13 variations in fluids from the Cerro Prieto geothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Janik, C.J.; Nehring, N.L.; Huebner, M.A.; Truesdell, A.H.

    1982-08-10

    The carbon isotope compositions of CO/sub 2/ in steam from Cerro Prieto production well have been measured for 1977, 1979, and 1982. Variations in the delta/sup 13/C values are caused by production-related changes in the chemical and physical parameters of the geothermal system. In 1977, most CO/sub 2/ in the reservoir was isotopically light (delta/sup 13/C = -6.4 +/- 0.4). Heavier CO/sub 2/ was produced from wells in the center of the field (M5,M26,M27) due to deposition of isotopically light calcite caused by near-well boiling. In 1979 nearly all well showed relatively heavy CO/sub 2/, probably due to expansion of aquifer boiling and calcite precipitation. In 1982, many wells in the central part of the field were shut in. The amount of drawndown decreased and as temperatures and pressures near the wells increased, the boiling zones collapsed. The CO/sub 2/ in the fluid then exchanged with the precipitated calcite and became isotopically lighter. The sensitivity of carbon isotopes to calcite precipitations caused by aquifer boiling and to reequilibration with this deposited calcite upon decrease of boiling suggests use as an indicator of these aquifer processes. Surficial CO/sub 2/ of thermal origin was collected in 1981. Generally, the carbon-13 contents were close to CO/sub 2/ from production wells except for high-temperature mud pots and fumaroles containing isotopically light CO/sub 2/ derived from near surface alteration of organic matter.

  20. Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    A. Casteller

    2008-05-01

    Full Text Available The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1 to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2 to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

  1. Glacier mass balance reconstruction by sublimation induced enrichment of chemical species on Cerro Tapado (Chilean Andes

    Directory of Open Access Journals (Sweden)

    P. Ginot

    2006-01-01

    Full Text Available A 36 m long ice core down to bedrock from the Cerro Tapado glacier (5536 m a.s.l, 30°08' S, 69°55' W was analyzed to reconstruct past climatic conditions for Northern Chile. Because of the marked seasonality in the precipitation (short wet winter and extended dry summer periods in this region, major snow ablation and related post-depositional processes occur on the glacier surface during summer periods. They include predominantly sublimation and dry deposition. Assuming that, like measured during the field campaign, the enrichment of chloride was always related to sublimation, the chemical record along the ice core may be applied to reconstruct the history of such secondary processes linked to the past climatic conditions over northern Chile. For the time period 1962–1999, a mean annual net accumulation of 316 mm water equivalent (weq and 327 mm weq loss by sublimation was deduced by this method. This corresponds to an initial total annual accumulation of 539 mm weq. The annual variability of the accumulation and sublimation is related with the Southern Oscillation Index (SOI: higher net-accumulation during El-Niño years and more sublimation during La Niña years. The deepest part of the ice record shows a time discontinuity; with an ice body deposited under different climatic conditions: 290 mm higher precipitation but with reduced seasonal distribution (+470 mm in winter and –180 mm in summer and –3°C lower mean annual temperature. Unfortunately, its age is unknown. The comparison with regional proxy data however let us conclude that the glacier buildup did most likely occur after the dry mid-Holocene.

  2. The Black-White Achievement Gap Revisited Revisitando la brecha en el rendimiento de estudiantes negros y blancos Revisitando a defasagem de rendimento academico dos estudantes negros e brancos

    Directory of Open Access Journals (Sweden)

    Henry Braun

    2010-09-01

    Full Text Available This study examines trends in Black student achievement and in the Black-White achievement gap over the period 2000 to 2007, employing data from ten states drawn from the NAEP Grade 8 mathematics assessments. Results are obtained for three levels of aggregation: the state, school poverty stratum within the state, and schools within poverty stratum. In addition, information on the ten states’ education policies for the period 1998 to 2005 was compiled. States relative ranks on the overall strength of their reform efforts were compared to their relative ranks with respect to their success in improving Black student achievement and in reducing the Black- White achievement gap. This study constitutes an extension of earlier work that considered the same issues for the period 1992 to 2000 and, thus, offers a unique comparison between the pre-NCLB era and the present one. Although the ten states certainly differed in their outcomes, the general picture at all three levels of aggregation is quite clear: The achievement gaps are substantial and the introduction of federally mandated high stakes test-based accountability through No Child Left Behind has had a very modest impact on the rates of improvement for Black students and on the pace of reductions in the achievement gaps between Black students and White students. Moreover, there was only a weak association between states’ policy rankings and their rankings related to test results. It appears there is a need for both fresh thinking on education reform and a more concerted effort to collect comprehensive longitudinal information on states' education policies.
    Este estudio examina las tendencias en el rendimiento académico de estudiantes negros y la brecha en el rendimiento de los estudiantes negros y blancos en el período 2000 a 2007, utilizando datos de las evaluaciones NAEP de Matemáticas para el octavo grado en diez estados. Se obtuvieron resultados para tres niveles de agregacio

  3. Structural control on geothermal circulation in the Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Argentina)

    Science.gov (United States)

    Giordano, Guido; Pinton, Annamaria; Cianfarra, Paola; Baez, Walter; Chiodi, Agostina; Viramonte, José; Norini, Gianluca; Groppelli, Gianluca

    2013-01-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous springs. This study presents new stratigraphic and hydrogeological data on the geothermal field, together with the analysis from remote sensed image analysis of morphostructural evidences associated with the structural framework and active tectonics. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field. Away from the main tectonic features, such as at the Cerro Tuzgle field, the less developed network of faults and fractures allows only a moderate upwelling of geothermal fluids and a mixing between hot and shallow cold waters. The integration of field-based and remote-sensing analyses at the Cerro Tuzgle-Tocomar area proved to be effective in approaching the prospection of remote geothermal fields, and in defining the conceptual model for geothermal circulation.

  4. El retrato de los «negros brujos»: Los archivos visuales de la antropología afrocubana (1900-1920) The «Negros Brujos» portrait: Visual Archives of Afro-Cuban Anthropology

    OpenAIRE

    Jorge Pavez Ojeda

    2009-01-01

    Proponemos mostrar aquí el lugar que ocupó la imagen fotográfica en la elaboración de los imaginarios africanistas en las primeras décadas del siglo XX en Cuba. A partir de la revisión de algunas obras de la antropología cubana, destacaremos los procedimientos por los cuales las fotografías fueron usadas y valoradas como evidencias de las teorías del «atavismo» y las «supervivencias» africanas en Cuba, a partir de estereotipos occidentales aplicados a la estética de los llamados «negros brujo...

  5. Estructura, composición y diversidad de la selva baja caducifolia del Cerro Verde, Nizanda (Oaxaca), México

    OpenAIRE

    José Antonio Gallardo Cruz; Meave, Jorge A.; Eduardo A. Pérez García

    2005-01-01

    En este estudio se describe la estructura, la composición florística y los patrones de diversidad de la selva baja caducifolia del Cerro Verde, localizado en Nizanda (Istmo de Tehuantepec, Oaxaca, México). En 30 parcelas de 100 m2 se censaron las plantas leñosas con DAP #8805; 1 cm (estrato alto), y en cinco subcuadros de 4 m2 dentro de cada una se censaron las plantas con DAP 1 cm, pero con altura 30 cm (estrato bajo). Se encontraron 194 especies distribuidas en 52 familias. La riqueza de...

  6. Dieta de murciélagos nectarívoros del Parque Nacional Cerros de Amotape, Tumbes

    OpenAIRE

    Edith Arias; Richard Cadenillas; Víctor Pacheco

    2011-01-01

    En el Perú se reporta la presencia de 18 especies de murciélagos nectarívoros, sin embargo se cuenta con poca información sobre la dieta de estas especies. En este estudio se reporta por primera vez la dieta de los nectarívoros Glossophaga soricina, Lonchophylla hesperia y Anoura geoffroyi en el bosque seco ecuatorial y del bosque tropical del Pacífico del Parque Nacional Cerros de Amotape, Tumbes. Analizamos 21 contenidos gastrointestinales e identificamos ocho morfotipos de polen pertenecie...

  7. Los marsupiales (Mammalia) del Mioceno Superior de la formación Cerro Azul (Provincia de la Pampa, Argentina)

    OpenAIRE

    Goin, Francisco Javier; Montalvo, Claudia; Visconti, G

    2000-01-01

    Se describe la asociación de marsupiales sudamericanos fósiles de edad Huayqueriense (Mioceno tardío) más completa hasta ahora conocida. Los ejemplares fueron exhumados de varias localidades fosilíferas nuevas del centro y norte de la provincia de La Pampa (Argentina central), en sedimentos asignables a la Formación Cerro Azul: Bajo Giuliani, Quehué, Telén, El Guanaco y Laguna Chillhué. El conjunto de las sedimentitas loessoides analizadas en los diferentes afloramientos de esta formación ind...

  8. Palaeoenvironment reconstruction, volcanic evolution and geochronology of the Cerro Blanco subcomplex, Nevados de Chillan volcanic complex, Central Chile

    OpenAIRE

    Mee, Katy; Gilbert, Jennie S.; McGarvie, David W.; Naranjo, Jose A.; Pringle, Malcolm S.

    2009-01-01

    Nevados de Chillán Volcanic Complex, central Chile, has been active for at least 640 ka—a period spanning a number of glacial and interglacial periods. Geologic mapping, radiometric dating and geochemical analysis have identified six new volcanic units and produced four new 40Ar/39Ar ages for Cerro Blanco, the northern subcomplex of Nevados de Chillán volcano. Compositions range from dacite to basaltic-andesite and a new geologic map is presented. Examination of lava fracture structures on bo...

  9. Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Grant, M.A. (DSIR, Wellington, New Zealand); Truesdell, A.H.; Manon, A.

    1981-01-01

    Chemical and physical data suggest that the relatively shallow western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapor. Local boiling occurs near most wells in response to pressure decreases, but no general vapor zone has formed.

  10. Fault Length Vs Fault Displacement Evaluation In The Case Of Cerro Prieto Pull-Apart Basin (Baja California, Mexico) Subsidence

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Nava Pichardo, F. A.; Farfan, F.; Garcia Arthur, M. A.; Orozco, L.; Brassea, J.

    2013-05-01

    The Cerro Prieto pull-apart basin is located in the southern part of San Andreas Fault system, and is characterized by high seismicity, recent volcanism, tectonic deformation and hydrothermal activity (Lomnitz et al, 1970; Elders et al., 1984; Suárez-Vidal et al., 2008). Since the Cerro Prieto geothermal field production started, in 1973, significant subsidence increase was observed (Glowacka and Nava, 1996, Glowacka et al., 1999), and a relation between fluid extraction rate and subsidence rate has been suggested (op. cit.). Analysis of existing deformation data (Glowacka et al., 1999, 2005, Sarychikhina 2011) points to the fact that, although the extraction changes influence the subsidence rate, the tectonic faults control the spatial extent of the observed subsidence. Tectonic faults act as water barriers in the direction perpendicular to the fault, and/or separate regions with different compaction, and as effect the significant part of the subsidence is released as vertical displacement on the ground surface along fault rupture. These faults ruptures cause damages to roads and irrigation canals and water leakage. Since 1996, a network of geotechnical instruments has operated in the Mexicali Valley, for continuous recording of deformation phenomena. To date, the network (REDECVAM: Mexicali Valley Crustal Strain Measurement Array) includes two crackmeters and eight tiltmeters installed on, or very close to, the main faults; all instruments have sampling intervals in the 1 to 20 minutes range. Additionally, there are benchmarks for measuring vertical fault displacements for which readings are recorded every 3 months. Since the crackmeter measures vertical displacement on the fault at one place only, the question appears: can we use the crackmeter data to evaluate how long is the lenth of the fractured fault, and how quickly it grows, so we can know where we can expect fractures in the canals or roads? We used the Wells and Coppersmith (1994) relations between

  11. Arterial oxygen saturation in healthy newborns delivered at term in Cerro de Pasco (4340 m) and Lima (150 m)

    OpenAIRE

    Gonzales Gustavo F; Salirrosas Amelia

    2005-01-01

    Abstract Background High altitude is associated with both low pulse oxygen saturation at birth and more pre-term deliveries. The present study was performed to determine pulse oxygen saturation in newborns at term in Cerro de Pasco (4340 m) and Lima (150 m) to test the hypothesis that low pulse oxygen saturation at birth at high altitudes was not observed at term deliveries. Methods The present study was designed to determine pulse oxygen saturation values through 1 minute to 24 hours and val...

  12. Estudio de la líqueno flora encontrada en el Cerro de Quininí, Tibacuy, Cundinamarca

    OpenAIRE

    Hormaza Francisco; Vivas Oscar; Parra Alejandro

    2000-01-01

    Se realizó un muestreo de la liquen o flora del cerro de Quininí, Tibacuy, Cundinamarca para estudiar las características morfológicas externas de los géneros de líquenes encontrados en el. A su vez se hizo la revisión bibliográfica acerca de dichos géneros, datando así la riqueza de líquenes en la zona con 8 géneros en total y con respecto al papel de bioindicadores se mostró el grado de intervención para el lugar.

  13. Vertical movement along the Cerro Prieto transform fault, Baja California, Mexico - a mechanism for geothermal energy renewal

    Energy Technology Data Exchange (ETDEWEB)

    Vonder Haar, S.; Noble, J.E.; Puente Cruz, I.

    1979-03-01

    Data from 53 geothermal wells to depths of 1 to 3 km on either side of the right-lateral Cerro Prieto fault, as well as geophysical data, indicate vertical displacements of this fault of 400 to 600 m. This episoidic vertical movement has offset deltaic sandstone reservoirs that are primarily at 1200 m and 1800 m depth and contain 250{sup 0} to 345{sup 0}C water. A major fracture system for convective fluid movement has been thus maintained, with production at 150 MW.

  14. TITAN2D simulations of pyroclastic flows at Cerro Machín Volcano, Colombia: Hazard implications

    Science.gov (United States)

    Murcia, H. F.; Sheridan, M. F.; Macías, J. L.; Cortés, G. P.

    2010-03-01

    Cerro Machín is a dacitic tuff ring located in the central part of the Colombian Andes. It lies at the southern end of the Cerro Bravo-Cerro Machín volcanic belt. This volcano has experienced at least six major explosive eruptions during the last 5000 years. These eruptions have generated pyroclastic flows associated with Plinian activity that have traveled up to 8 km from the crater, and pyroclastic flows associated with Vulcanian activity with shorter runouts of 5 km from the source. Today, some 21,000 people live within a 8 km radius of Cerro Machín. The volcano is active with fumaroles and has shown increasing seismic activity since 2004, and therefore represents a potentially increasing threat to the local population. To evaluate the possible effects of future eruptions that may generate pyroclastic density currents controlled by granular flow dynamics we performed flow simulations with the TITAN2D code. These simulations were run in all directions around the volcano, using the input parameters of the largest eruption reported. The results show that an eruption of 0.3 km 3 of pyroclastic flows from a collapsing Plinian column would travel up to 9 km from the vent, emplacing a deposit thicker than 60 m within the Toche River valley. Deposits >45 m thick can be expected in the valleys of San Juan, Santa Marta, and Azufral creeks, while 30 m thick deposits could accumulate within the drainages of the Tochecito, Bermellón, and Coello Rivers. A minimum area of 56 km 2 could be affected directly by this kind of eruption. In comparison, Vulcanian column-collapse pyroclastic flows of 0.1 km 3 would travel up to 6 km from the vent depositing >45 m thick debris inside the Toche River valley and more than 30 m inside the valleys of San Juan, Santa Marta, and Azufral creeks. The minimum area that could be affected directly by this kind of eruption is 33 km 2. The distribution and thickness of the deposits obtained by these simulations are consistent with the hazard

  15. 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

  16. 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

  17. Reconstructing water level in Hoyo Negro, Quintana Roo, Mexico, implications for early Paleoamerican and faunal access

    Science.gov (United States)

    Collins, S. V.; Reinhardt, E. G.; Rissolo, D.; Chatters, J. C.; Nava Blank, A.; Luna Erreguerena, P.

    2015-09-01

    The skeletal remains of a Paleoamerican (Naia; HN5/48) and extinct megafauna were found at -40 to -43 mbsl in a submerged dissolution chamber named Hoyo Negro (HN) in the Sac Actun Cave System, Yucatan Peninsula, Mexico. The human remains were dated to between 12 and 13 Ka, making these remains the oldest securely dated in the Yucatan. Twelve sediment cores were used to reconstruct the Holocene flooding history of the now phreatic cave passages and cenotes (Ich Balam, Oasis) that connect to HN. Four facies were found: 1. bat guano and Seed (SF), 2. lime Mud (MF), 3. Calcite Rafts (CRF) and 4. Organic Matter/Calcite Rafts (OM/CRF) which were defined by their lithologic characteristics and ostracod, foraminifera and testate amoebae content. Basal radiocarbon ages (AMS) of aquatic sediments (SF) combined with cave bottom and ceiling height profiles determined the history of flooding in HN and when access was restricted for human and animal entry. Our results show that the bottom of HN was flooded at least by 9850 cal yr BP but likely earlier. We also found, that the pit became inaccessible for human and animal entry at ≈8100 cal yr BP, when water reaching the cave ceiling effectively prevented entry. Water level continued to rise between ≈6000 and 8100 cal yr BP, filling the cave passages and entry points to HN (Cenotes Ich Balam and Oasis). Analysis of cave facies revealed that both Holocene sea-level rise and cave ceiling height determined the configuration of airways and the deposition of floating and bat derived OM (guano and seeds). Calcite rafts, which form on the water surface, are also dependent on the presence of airways but can also form in isolated air domes in the cave ceiling that affect their loci of deposition on the cave bottom. These results indicated that aquatic cave sedimentation is transient in time and space, necessitating extraction of multiple cores to determine a limit after which flooding occurred.

  18. Efectos del control del picudo negro (Cosmopolites sordidus en el plátano.

    Directory of Open Access Journals (Sweden)

    Ignacio Armendáriz

    2016-06-01

    Full Text Available El objetivo del estudio fue comprobar el efecto en el plátano de las capturas masivas de adultos con feromonas y de la aplicación de hongos entomopatógenos sobre Cosmopolites sordidus. La investigación se realizó en el Carmen, Manabí, Ecuador, de diciembre 2013 a octubre 2014 en una parcela de nueva plantación de plátano Barraganete y se valoró el efecto de la eliminación de restos vegetales de las parcelas. El diseño experimental fue al azar con tres repeticiones. En laboratorio se comprobó la infectividad de la cepa de Beauveria bassiana sobre adultos del picudo negro y del picudo café (Metamasius hemipterus (92,80 y 100% en M. hemipterus frente a 46,70 y 16,20% en C. sordidus. Las capturas de adultos fueron continuas a lo largo del ensayo, con una media de 0,37 adultos/trampa/día. Los datos agronómicos indicaron una diferencia positiva y significativa (análisis de la varianza de los tratamientos frente al control en el perímetro del pseudotallo (F de 4,982 y en el peso de los racimos entre las parcelas limpias con feromonas y con hongos limpias frente al control (F= 3,994. Al comparar los tratamientos el peso del racimo y la longitud de los dedos fueron significativamente mayores en las parcelas de feromonas frente a las de hongos (F = 4,508. Las capturas de adultos con feromonas no estuvieron condicionadas por la limpieza de las parcelas, aunque esta sí incidió en la altura de las plantas (F= 4,245.

  19. The Role of Biofilms in the Sedimentology of Actively Forming Gypsum Deposits at Guerrero Negro, Mexico

    Science.gov (United States)

    Vogel, Marilyn B.; Des Marais, David J.; Turk, Kendra A.; Parenteau, Mary N.; Jahnke, Linda L.; Kubo, Michael D. Y.

    2009-11-01

    Actively forming gypsum deposits at the Guerrero Negro sabkha and saltern system provided habitats for stratified, pigmented microbial communities that exhibited significant morphological and phylogenetic diversity. These deposits ranged from meter-thick gypsum crusts forming in saltern seawater concentration ponds to columnar microbial mats with internally crystallized gypsum granules developing in natural anchialine pools. Gypsum-depositing environments were categorized as forming precipitation surfaces, biofilm-supported surfaces, and clastic surfaces. Each surface type was described in terms of depositional environment, microbial diversity, mineralogy, and sedimentary fabrics. Precipitation surfaces developed in high-salinity subaqueous environments where rates of precipitation outpaced the accumulation of clastic, organic, and/or biofilm layers. These surfaces hosted endolithic biofilms comprised predominantly of oxygenic and anoxygenic phototrophs, sulfate-reducing bacteria, and bacteria from the phylum Bacteroidetes. Biofilm-supported deposits developed in lower-salinity subaqueous environments where light and low water-column turbulence supported dense benthic microbial communities comprised mainly of oxygenic phototrophs. In these settings, gypsum granules precipitated in the extracellular polymeric substance (EPS) matrix as individual granules exhibiting distinctive morphologies. Clastic surfaces developed in sabkha mudflats that included gypsum, carbonate, and siliclastic particles with thin gypsum/biofilm components. Clastic surfaces were influenced by subsurface brine sheets and capillary evaporation and precipitated subsedimentary gypsum discs in deeper regions. Biofilms appeared to influence both chemical and physical sedimentary processes in the various subaqueous and subaerially exposed environments studied. Biofilm interaction with chemical sedimentary processes included dissolution and granularization of precipitation surfaces, formation of

  20. BIOLOGÍA DEL ÁFIDO NEGRO (Aphis craccivora: APHIDIDAE) SOBRE FRÍJOL CAUPI (Vigna unguiculata, FABACEAE)

    OpenAIRE

    Nataly DE LA PAVA S; Paula Andrea SEPÚLVEDA-CANO

    2015-01-01

    Este trabajo describe los parámetros biológicos y poblacionales del pulgón negro, Aphis craccivora Koch, sobre fríjol caupí (Vigna unguiculata (L. Walp.)), bajo condiciones de laboratorio. Los insectos se criaron sobre plántulas individualizadas a una temperatura promedio de 28 °C, humedad relativa de 70 % y fotoperiodo de 12 horas. Los parámetros medidos fueron periodo ninfal, fecundidad, supervivencia, periodo pre-reproductivo y aspectos relativos a la tasa de crecimiento del áfido. La tasa...

  1. Biogeochemical characteristics of organic matter in the particulate and colloidal fractions downstream of the rio Negro and Solimoes rivers confluence

    OpenAIRE

    Gadel, François; Serve, Léon; Benedetti, Marc,; Leticia Cotrim Da Cunha,; Blazi, Jean-Louis

    2000-01-01

    International audience The analysis of organic matter in the rio Negro, rio Solimões and rio Amazonas focused on total organic carbon (TOC), as determined at two main sizes, the particulate form ($> 0.2 \\mu$m) and the colloidal form ($0.2 \\mu$m to 5000 dalton). These fractions were obtained by tangential ultrafiltration carried out on 50 l water samples. The total polysaccharide contents were determined by a colorimetric method, the main classes of organic compounds by pyrolysis and gas ch...

  2. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico

    OpenAIRE

    Dillon, Jesse G.; Carlin, Mark; Gutierrez, Abraham; Nguyen, Vivian; McLain, Nathan

    2013-01-01

    The goal of this study was to use environmental sequencing of 16S rRNA and bop genes to compare the diversity of planktonic bacteria and archaea across ponds with increasing salinity in the Exportadora de Sal (ESSA) evaporative saltern in Guerrero Negro, Baja CA S., Mexico. We hypothesized that diverse communities of heterotrophic bacteria and archaea would be found in the ESSA ponds, but that bacterial diversity would decrease relative to archaea at the highest salinities. Archaeal 16S rRNA ...

  3. Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

    2011-07-15

    In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

  4. Cuerpos intrusivos asociados a las mineralizaciones polimetálicas del depósito Cerro León, área del anticlinal El Tranquilo, Santa Cruz: evidencias geofísicas Intrusive bodies associated with the polymetallic mineralization of the Cerro León deposit, area of Cerro Tranquilo anticline, Santa Cruz: Geophysical evidence

    OpenAIRE

    G. A Peñalva; S. M. Jovic; C. J. Chernicoff; D.M. Guido; I. Schalamuk

    2008-01-01

    Las características geológicas tales como presencia de cuerpos intrusivos y subvolcánicos someros básicos a intermedios y de las mineralizaciones con alto contenido de sulfuros del área del anticlinal El Tranquilo, son particulares y poco representadas en el macizo del Deseado. El depósito polimetálico vetiforme Cerro León presenta una signatura geoquímica-mineralógica que lo diferencia del clásico modelo epitermal de baja sulfuración característico del macizo del Deseado. Los datos aeromagné...

  5. 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.

  6. Tacuari formation (Nov. Nom.): Lithostratigraphy, facies, environment, age and geological significance (Cerro Largo - Uruguay)

    International Nuclear Information System (INIS)

    The definition of the Tacuari formation is proposed to group a set of glacial and fossiliferous siliciclastic rock deposited during the Upper proterozoic in the northeast of Uruguay. Up to this paper these lithologies were included in the San Gregorio formation (Carboniferous - Permian - Norte Basin). However, Leiosphaeridia tenuissima, L, minutissima, Myxcocooides distola, M, siderophila, Soldadophycus bossil and S. major were recorded in these rocks.This finded motivated the accomplishment of geological surveys that allowed to ferify the glacial origin of the Tacuari formation, to define its stratigraphic relationships and to corroborate its affectation by the Sierra Ballena shear zone. Two association of facies were recognized in the Tacuari formation: the base is represented by facies association A (outwash plains), characterized diamictites, sandostones and pelites; at the top, the facies association B (glaciomarine) includes a package of rhythmites with dropstones. On account of the tectonic setting, nature of sedimentation, age, and fossils, the definition of Tacuari formation constitutes a novel contribution to the regional evolutionary model of the Upper proterozoic. discussion of posible stratigraphc correlations with other neoproterozoic units of Western wondwana is also attempted

  7. Como aumentar a proporção de estudantes negros na universidade? How to increase the rate of black students at university?

    OpenAIRE

    Marcelo Henrique Romano Tragtenberg; João Luiz Dornelles Bastos; Lincon Hideo Nomura; Marco Aurélio Peres

    2006-01-01

    Existem diferentes propostas para aumento da população negra na universidade. Com o objetivo de investigar o impacto da adoção de algumas propostas na proporção de negros no ensino superior, a partir dos bancos de dados do vestibular e dos matriculados em 2004 na Universidade Federal de Santa Catarina, foi estudada a distribuição étnico-racial na instituição. Verificou-se baixa proporção de estudantes negros candidatos e aprovados no vestibular e matriculados na referida universidade. A dupli...

  8. 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

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

    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.

  10. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  11. Volcanismo y mineralización asociada en el área del cerro Tiporco, provincia de San Luis, Argentina

    Directory of Open Access Journals (Sweden)

    Ibañes, Oscar D.

    2011-12-01

    Full Text Available Abstract: Volcanism and associated mineralization in the Cerro Tiporco area, San Luis province, Argentina. The Tiporco area is located west of the Cerros del Rosario volcanic field and 66 km northeast of San Luis city. In the Santa Isabel-Córdoba quarry, a pyroclastic sequence has been recognized (Volcaniclastitas Lomitas lying on sedimentary rocks which belong to the Miocene Santa Isabel Formation. The stratigraphic arrangement indicates a Pliocene age. Within the sequence, upper and lower units may be distinguished, encompassing co-ignimbrite lithic breccias, surges and ignimbrite deposits. The volcanism in this area is characterized by initial explosive activity, with recurrent ignimbritic eruptions and phreatomagmatic episodes (surges, ending with the emplacement of domes and associated lava flows (Tiporco and Lomita. Both the pyroclastics and the lavas represent near-vent facies. A well defined NW-SE fault system controlled the emplacement of the volcanics. The associated mineralization consists of calcareous onyx and aragonite veins, calcite veinlets and travertine manifestations. The latter indicate a paleosurface consistent with the superficial levels of an epithermal system and very scarce erosion. In consequence, it is possible to infer the presence of metalliferous manifestations at depth as part of the same hydrothermal system.

  12. Vulnerabilidad al ascenso del nivel del mar en la costa de la provincia de Río Negro Vulnerability to sea-level rise of the coast of the Río Negro province

    Directory of Open Access Journals (Sweden)

    R.R. Kokot

    2004-09-01

    Full Text Available Los escenarios elaborados a escala mundial por el Panel Internacional de Cambio Climático (IPCC respecto al ascenso del nivel del mar, debido principalmente a la expansión térmica del océano y a las pérdidas de masa de los glaciares, prevén valores que en promedio oscilan entre 0,09 y 0,88 m desde 1990 al 2100, con tendencia a la aceleración. Los impactos potenciales por la elevación del mar conducen a cambios en el área costera, que incluyen inundación, incremento en el retroceso costero, e intrusión salina en los acuíferos y estuarios. Con el objeto de posibilitar un adecuado manejo de la costa de la provincia de Río Negro, se efectuó una zonificación que permite disponer de información referente a la vulnerabilidad por ascenso del nivel del mar, a través de un mapa de simple lectura. Las áreas de peligrosidad geológica, referidas a inundación permanente y/o episódica se identificaron mediante índices de vulnerabilidad costera, también denominados índices de susceptibilidad, obtenidos a través de la aplicación de un algoritmo que relaciona variables obtenidas a partir de información geológica costera, oceanográfica y climatológica. Las zonas más vulnerables al ascenso del nivel del mar, corresponden a Balneario El Salado (Playas Doradas, San Antonio Oeste - San Antonio Este, Caleta de los Loros y la desembocadura del río Negro, mientras que el tramo de costa correspondiente a la costa acantilada ubicada al oeste del río Negro y al sur de punta Pórfido, muestra una vulnerabilidad baja.According to the global predictions by the International Panel of Climate Change (IPCC, the sea-level rise due to ocean thermal expansion and glacier mass loss will average 0.09 - 0.88 m between 1990 and 2100, with a trend toward an increasing rise rate. Potential impacts of this increasing rise rate relate to changes in the coastal area, including floods, increased coastal retreat, and saline intrusion in the coastal acquiferous

  13. Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study

    Directory of Open Access Journals (Sweden)

    Jose Rodrigues Coura

    2013-12-01

    Full Text Available A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals.

  14. Escola pública para os negros e os pobres no Brasil: uma invenção imperial

    Directory of Open Access Journals (Sweden)

    Cynthia Greive Veiga

    2008-01-01

    Full Text Available El artículo presenta datos finales de estudios sobre la escolarización de niños pobres, negros y mestizos en Brasil, específicamente en la provincia de Minas Gerais durante la vigencia de la Monarquía constitucional (1824- 1889. Para su desarrollo fueron investigados diferentes documentos de la instrucción pública y la principal tesis es demostrar el carácter popular de la escuela del Imperio y discutir sobre como su fracaso en la función de instruir y civilizar pobres, negros y mestizos puede estar exactamente relacionada con la descalificación de la condición de educabilidad de la clientela a la cual se destinaba la escuela pública del siglo XIX. Destaca también la importancia de la temática para la ampliación de los debates sobre la historia de la escuela en Brasil.

  15. FACTIBILIDAD ECONÓMICA DE LA APLICACIÓN DE INOCULANTES MICROBIANOS EN EL CULTIVO DEL TABACO NEGRO

    Directory of Open Access Journals (Sweden)

    Yarilis León González

    2016-01-01

    Full Text Available La investigación se realizó durante las campañas tabacaleras 2010/2011 y 2011/2012 en la Estación Experimental del Tabaco de San Juan y Martínez, Pinar del Río, Cuba. El objetivo fue determinar la factibilidad económica de dos métodos de aplicación de inoculantes microbianos en el cultivo del tabaco negro al sol. Se utilizó un diseño experimental de bloques al azar con 19 tratamientos y cuatro repeticiones. Se estudiaron diferentes dosis de fertilizante mineral en combinación con dos inoculantes microbianos (Azotobacter chroococcum y Bacillus megatherium var. phosphaticum. Se utilizaron dos variantes: una inoculación en el momento de la siembra del semillero y otra variante que incluye la inoculación inicial y una reinoculación en el trasplante. Con la reinoculación y disminución del fertilizante mineral se lograron mejores resultados que con el método de inoculación. Se demostró la factibilidad económica de la reinoculación de A. chroococcum + B. megatherium var. phosphaticum y el 75 % de la dosis total de nitrógeno y fósforo en el cultivo del tabaco negro al sol.

  16. Characterisation of an enamelled metallic object found in Guerrero Negro (Baja California) by PIXE and RBS techniques

    Energy Technology Data Exchange (ETDEWEB)

    Calvo del Castillo, H. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid (Spain); Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Centre Europeen d' Archeometrie - I.P.N.A.S., Universite de Liege, Allee du 6 Aout, 10 Bat-15, Sart Tilman, 4000-Liege 1 (Belgium)], E-mail: hcalvo@ulg.ac.be; Ruvalcaba, J.L. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Calderon, T. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid (Spain); Salinas Nolasco, M.F. [Coordinacion de Conservacion del Patrimonio Cultural, Instituto Nacional de Antropologia e Historia (Mexico); Mejia, L.M. [Direccion de Arqueologia Subacuatica, Instituto Nacional de Antropologia e Historia (Mexico); Perdigon, K. [Coordinacion de Conservacion del Patrimonio Cultural, Instituto Nacional de Antropologia e Historia (Mexico)

    2008-05-15

    The coast of Guerrero Negro (Baja California) has been known for a long time by archaeologists for its shipwrecks. Archaeologists are recovering objects that come from sunken Spanish galleons in the colonial period, and reach the American coast in the frontier of the USA with Mexico. An enamelled metallic object was found next to the beach in Guerrero Negro. We have analysed the piece with proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) in an attempt to establish whether the object could come from one of the colonial shipwrecks and to valuate its cleaning process. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) have been also performed in three samples taken from the object in order to observe the heterogeneity of the material. The materials found revealed the presence of typical lead-glass enamels from with pigments such as cuprite (red), or lead-tin yellow used in colonial times. The metallic part consisted of brass. As for the cleaning process, the average efficiency considered as the weight% of chlorine removed, was of 83.4% for brass and 100% for ename0008.

  17. Relatos en Rojo y Negro: Aportes de Jorge Ricardo Masetti al periodismo contrahegemónico

    Directory of Open Access Journals (Sweden)

    Daniel González Almandoz

    2016-03-01

    Full Text Available Este trabajo pretende aproximarse a los aportes que Jorge Ricardo Masetti realizó a la construcción de experiencias periodísticas contrahegemónicas. Masetti fue un periodista argentino que en 1958 ascendió a Sierra Maestra para cubrir el levantamiento del M 26-7. Allí obtuvo entrevistas exclusivas con Fidel Castro y Ernesto Guevara. Luego, ya como partícipe de la Revolución Cubana, fundó y fue el primer director de la agencia de noticias Prensa Latina. Desde ese medio provocó rupturas con el modelo de comunicación mediática dominante en la época, y generó síntesis novedosas que dieron lugar a aportes a la reflexión y a la práctica periodística. Sin embargo, Masetti está ausente del imaginario colectivo del Periodismo. Esta investigación se instala en un encuentro entre los Estudios sobre Periodismo y la Historia de las Ideas, y es atravesada en su enfoque teórico por la Teoría de la Hegemonía.

  18. Mecanismos de deformación en la transición milonitas/striped gneiss y milonitas/ ultramilonitas en las sierras de Azul, cratón del Río de la Plata, Buenos Aires

    Directory of Open Access Journals (Sweden)

    María C. Frisicale

    2010-08-01

    Full Text Available En el extremo occidental de la megacizalla de Azul se identificaron una serie de rocas miloníticas que presentan un grado de deformación variable e incluyen protomilonitas, milonitas, ribbon mylonites, striped gneisses y ultramilonitas. Se examinaron en forma detallada los mecanismos de deformación actuantes sobre los minerales principales de estas rocas, como feldespatos, cuarzo, anfíboles y piroxenos. El análisis de los mecanismos de deformación permitió realizar una estimación del grado metamórfico alcanzado en este sector de la zona de cizalla. Así se reconocen claramente dos áreas con diferente grado metamórfico, una en la que la deformación se habría producido en facies de anfibolita a granulita (temperaturas superiores a 600° y que se reconoce en los afloramientos del sector norte, cerro Negro y manantiales de Pereda; y una segunda área, que incluye los afloramientos de las estancias La Manuela y La Chiquita, donde la deformación, de menor intensidad, se desarrolló bajo condiciones de facies de esquistos verdes. Asimismo se analizaron los indicadores cinemáticos macro y microscópicos tales como estructuras S-C, granos rígidos fragmentados, porfiroclastos rotados y estructuras del tipo mineral-fish, con la finalidad de determinar el sentido de movimiento de las masas rocosas en esta área particular, y compararlo con los resultados existentes para el resto de la megacizalla de Azul.

  19. 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 ...

  20. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  1. Condiciones para la transmision del hantavirus en zona andina de Río negro, Argentina

    Directory of Open Access Journals (Sweden)

    Gabriel Talmon

    2014-10-01

    Full Text Available El Síndrome Pulmonar por Hantavirus (SPH es una enfermedad de etiología viral que causa en el hombre un cuadro respiratorio grave. En Patagonia, la enfermedad es causada por el virus Andes Sur (AND, transmitido por el roedor Oligoryzomys longicaudatus. El objetivo del presente trabajo fue identificar las actividades del hombre que favorecen su exposición a roedores, denominados escenarios de contagio. Se realizó un estudio retrospectivo a partir de información recolectada en investigaciones de casos ocurridos en Río Negro, mediante Fichas Clínico-Epidemiológicas e informes de evaluación ecológico/ambiental. Se definieron como variables a ser consideradas: edad, sexo, época del año, grado de urbanización, localización geográfica, integración del hombre al hábitat de roedores, fuente probable de exposición, actividad humana y nivel de saneamiento. Se estudiaron 32 casos. La exposición rural se verificó en 18 (56.2% de los casos y 10 (31.3% en paraje rural (grupo de viviendas en zona rural. En relación al ambiente antropogénico 24 (75% resultaron en ambientes modificados por el hombre y 8 (25% en áreas poco modificadas. El sitio de exposición de mayor importancia en El Bolsón fue el interior de edificaciones en 8 de los 18 casos allí registrados (44.5%, mientras que en Bariloche fueron ambientes de exterior con 8/14 (57.1% casos. La actividad de riesgo fue laboral en 23 (71.9% de los casos y recreacional en 7 (28.1%. Determinar los escenarios de contagio a nivel local ha aportado información para aplicar todos los recursos disponibles en materia de prevención y educación sanitaria.

  2. Yacimientos de Halloysita en Mamil Choique,provincia de Río Negro, Patagonia

    Directory of Open Access Journals (Sweden)

    Fernanda Cravero

    2009-11-01

    Full Text Available En la provincia de Río Negro, al norte de la localidadde Mamil Choique, se explotan depósitos minerales cuyo material secomercializacomo caolín. Mediante estudios mineralógicos se determinó que el mineralprincipal es halloysita-(10 Å acompañado por cantidades menores de esmectita ycristobalita, siendo el primer yacimiento en la Argentina de este mineral y unode los pocos en el mundo. La halloysita se presenta en cristales tubulares,cilíndricos, menores a 0,5 µm de largo y condiámetros menores a 0,2 µm. Laidentificación de la halloysita-(10Å, corroborada mediante la intercalacióncon formamida, fue además posible debido al cuidado puesto en el embalaje ytraslado de las muestras pues este mineral se deshidrataa temperatura ambientetransformándose en halloysita- (7 Å, la cual es fácilmente confundida concaolinita. El mineral se presenta en zonas alteradas, sobre rocas ignimbritas decomposición riolítica pertenecientes a la Formación Huitrera de edad eocena.Este proceso se caracteriza principalmente por una intensa lixiviación de loselementos alcalinos y alcalinos térreos, y un incremento en la concentraciónrelativa de alúmina. El origen de la alteración no se ha establecido conprecisión, pero la mineralogía simple, la ausencia de minerales característicosy de elementos minoritarios o trazas de ambientes epitermales, sumado a laexistencia de un clima templado húmedo a partir del Eoceno, permite suponer unaformación de tipo meteórico. La determinación de halloysita plantea la revisiónen la utilización de material de este depósito, ya que este mineral poseepropiedades muy diferentes a las de los otros minerales del grupo del caolín.

  3. Gut transport characteristics in herbivorous and carnivorous serrasalmid fish from ion-poor Rio Negro water.

    Science.gov (United States)

    Pelster, Bernd; Wood, Chris M; Speers-Roesch, Ben; Driedzic, William R; Almeida-Val, Vera; Val, Adalberto

    2015-02-01

    Three closely related characids, Tambaqui (omnivore), black Piranha (carnivore), and Pacu (herbivore), all Serrasalmidae, inhabit the ion-poor, acidic Rio Negro. We compared O2-consumption and N excretion rates in vivo, and sodium, chloride, glucose, and ammonia transport characteristics of gut sac preparations in vitro. The Pacu had a significantly higher weight-specific oxygen consumption, and a lower N/Q ratio than the omnivorous Tambaqui, and a significantly lower urea-N excretion rate than the carnivorous black Piranha, suggesting N-limitation in the herbivorous Pacu. With a value of 2.62 ± 0.15, gut to fork length ratio in the Pacu was about 2.5 times higher than in the black Piranha, and 2.0 times higher than in the Tambaqui. Anterior intestinal activities of three enzymes involved in N-fixation for amino acid synthesis (glutamate dehydrogenase, glutamate-oxaloacetate transferase, and glutamate-pyruvate transferase) were generally greatest in the carnivore and lowest in the herbivore species. In all three species, sodium, chloride, glucose, and ammonia were taken up at high rates from the intestine, resulting in an isosmotic fluid flux. Comparing the area-specific fluid flux of the anterior, mid, and posterior gut sections, no difference was detected between the three sections of the Pacu, while in the Tambaqui, it was highest in the anterior section, and in the black Piranha highest in the middle section. Overall, the area-specific uptake rates for sodium, chloride, glucose, and ammonia of anterior, mid, and posterior sections were similar in all three species, indicating that there is no difference in the area-specific transport rates associated with trophic position. The net ammonia uptake flux from gut interior was not significantly different from the net ammonia efflux to the serosal fluid, so that the ammonia removed from the intestine by the mucosal epithelium was quantitatively transferred through the tissue to the serosal side in all three

  4. El complejo deslizamiento de Ailinco-Cerro Papas-Las Olletas (Departamento Minas, norte del Neuquén, Argentina The complex landslide of Ailinco-Cº Papas-Las Olletas, northern Neuquén, Argentina

    Directory of Open Access Journals (Sweden)

    E.F. González Díaz

    2003-06-01

    Full Text Available De acuerdo a los antecedentes disponibles, acumulaciones de aspecto tilloide que conforman el irregular paisaje de un amplio sector de la cuenca de drenaje del arroyo Ailinco y que se extiende al pie del extremo sur de la serranía de la Puntilla y del faldeo oeste del Cº Papas y en el paraje de las Olletas, han sido consideradas como propias de la génesis glaciaria (morenas; tills. Los autores las interpretan como correspondientes a depósitos de un complejo conjunto local de grandes movimientos gravitacionales, en el que se han distinguido tres avalanchas de rocas, siendo las mayores aquellas del Cº Las Papas y de Ailinco y otra de menor porte ocurrida en la zona de Las Olletas. Sólo se describe su distribución y sus principales características morfológicas Se propone como el promotor de los mismos a la energía sísmica, teniendo en cuenta las condiciones sismotectónicas de la región y antecedentes de otros similares movimientos cercanos, ya analizados por los autores En el mapa geomorfológico adjunto, que cubre prácticamente la totalidad del área de las cuencas de los arroyos Ailinco y Manchana Covunco, se distinguen la presencia y distribución de otras geoformas menores, cuyo origen está relacionado con procesos propios de la morfogenia glaciaria, de un ambiente local de condiciones periglaciarias actuales y de la remoción en masa.At the southern end of the Sierra de la Puntilla Range in northern Neuquén province, extensive deposits of "tilloid" features in a morphological environment with hummocky-topography were observed. Previous studies suggest their relation with glacial morphogenesis (moraines; tills. We propose instead here their relationship to large gravitational movements triggered by seismic shock, and we distinguish two rock-avalanches and a third considered as a minor landslide. The most important is the "Cerro Papas rock-avalanche" which occurred on its western slope. The "Ailinco rock-avalanche" is situated on

  5. Land subsidence in the Cerro Prieto Geothermal Field, 1 Baja California, Mexico, from 1994 to 2005. An integrated analysis of DInSAR, levelingand geological data.

    Energy Technology Data Exchange (ETDEWEB)

    Sarychikhina, O; Glowacka, E; Mellors, R; Vidal, F S

    2011-03-03

    Cerro Prieto is the oldest and largest Mexican geothermal field in operation and has been producing electricity since 1973. The large amount of geothermal fluids extracted to supply steam to the power plants has resulted in considerable deformation in and around the field. The deformation includes land subsidence and related ground fissuring and faulting. These phenomena have produced severe damages to infrastructure such as roads, irrigation canals and other facilities. In this paper, the technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) is applied using C-band ENVISAR ASAR data acquired between 2003 and 2006 to determine the extent and amount of land subsidence in the Mexicali Valley near Cerro Prieto Geothermal Field. The DInSAR results were compared with published data from precise leveling surveys (1994- 1997 and 1997-2006) and detailed geological information in order to improve the understanding of temporal and spatial distributions of anthropogenic subsidence in the Mexicali Valley. The leveling and DInSAR data were modeled to characterize the observed deformation in terms of fluid extraction. The results confirm that the tectonic faults control the spatial extent of the observed subsidence. These faults likely act as groundwater flow barriers for aquifers and reservoirs. The shape of the subsiding area coincides with the Cerro Prieto pull-apart basin. In addition, the spatial pattern of the subsidence as well as changes in rate are highly correlated with the development of the Cerro Prieto Geothermal Field.

  6. An integrated model for the natural flow regime in the Cerro Prieto hydrothermal system based upon petrological and isotope geochemical criteria

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Williams, A.E.; Hoagland, J..

    1981-01-01

    Studies of cuttings and cores at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced.

  7. El frente de corrimiento andino al nivel de los cerros Penitentes y Visera (alta Cordillera de Mendoza: aspectos cronológicos y cartográficos

    Directory of Open Access Journals (Sweden)

    Jean-Claude Vicente

    2009-10-01

    Full Text Available El hallazgo de una iportante fauna de invertebrados marinos del Tithoniano superior a espaldas del cerro Penitentes en la secuencia carbonática basal de la primera escama del frente de corrimiento andino, confirma la lógica tectónica de un despegue de esta unidad a nivel del Yeso Principal y lleva a invalidar ciertas correlaciones litoestratigráficas y bosquejos paleogeográficos asignados a la Formación La Manga. Por otro lado, el análisis de algunos perfiles claves en torno al cerro Penitentes entre la quebrada Vargas y el cerro Visera permite presentar una reinterpretación tectónica del sector. Esta se sustenta en el reconocimiento y la diferenciación de las unidades terciarias básicas representadas por los Conglomerados Penitentes (Mioceno inferior y los Aglomerados Santa María (Mioceno superior en una relación muy similar a la descrita anteriormente al norte de Puente del Inca. El estudio permite seguir las interferencias, en un contexto polifásico, entre las reactivaciones del corrimiento Penitentes de piel fina y un cabalgamiento frontal de piel gruesa que repite la secuencia terciaria. La discordancia entre las secuencias terciarias y el emplazamiento de una klippe de Malm sobre los Conglomerados Penitentes del sinclinal del cerro Visera, conduce a otorgar cierta importancia a la fase del final del Mioceno inferior.

  8. Land subsidence in the Cerro Prieto Geothermal Field, Baja California, Mexico, from 1994 to 2005: An integrated analysis of DInSAR, leveling and geological data

    Science.gov (United States)

    Sarychikhina, Olga; Glowacka, Ewa; Mellors, Robert; Vidal, Francisco Suárez

    2011-07-01

    Cerro Prieto is the oldest and largest Mexican geothermal field in operation and has been producing electricity since 1973. The large amount of geothermal fluids extracted to supply steam to the power plants has resulted in considerable deformation in and around the field. The deformation includes land subsidence and related ground fissuring and faulting. These phenomena have produced severe damages to the local infrastructure such as roads, irrigation canals and other facilities. In this paper, the technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) is applied using C-band ENVISAR ASAR data acquired between 2003 and 2006 to determine the extent and amount of land subsidence in the Mexicali Valley near Cerro Prieto Geothermal Field. The DInSAR results were compared with published data from precise leveling surveys (1994-1997 and 1997-2006) and detailed geological information in order to improve understanding of the temporal and spatial distributions of anthropogenic subsidence in the Mexicali Valley. The leveling and DInSAR data were modeled to characterize the observed deformation in terms of fluid extraction. The results confirm that the tectonic faults control the spatial extent of the observed subsidence. These faults likely act as groundwater flow barriers for aquifers and reservoirs. The shape of the subsiding area coincides with the Cerro Prieto pull-apart basin. In addition, the changes in spatial pattern and rate of the subsidence are correlated with the development of the Cerro Prieto Geothermal Field.

  9. 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

  10. [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

  11. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease resistance genes in common bean cultivar Ouro Negro

    Science.gov (United States)

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean. Ouro Negro is a highly productive Mesoamerican black-seeded common bean cultivar possessing the dominant Co-10 and Phg-ON genes that confer resistance to ANT and ALS, respectively. In this study we elucidate the ...

  12. The Effect of a Parent Education on the Self-Concept, Achievement, and Behavior of Educable Mentally Retarded Negro Pre-Adolescents.

    Science.gov (United States)

    Schleicher, Kurt Walter

    This study determined whether a systematic program of parent education for a period of six weeks would effect significant changes in the self-concept, attitude, behavior, and academic achievement of the mentally retarded children of these parents. Two groups of educable mentally retarded Negro pre-adolescents were compared on measures of…

  13. The Relationship between the Race of Characters in a Literary Selection and the Literary Responses of Negro and White Adolescent Readers.

    Science.gov (United States)

    Brewbaker, James Martin

    This study was undertaken to identify differences in the literary responses of adolescents related to race-of-characters (white, Negro, and neutral) in three versions of a short story. Each of 281 subjects (ninth- and eleventh-grade) read one story version and then--on an adapted semantic differential instrument--rated nine elements from the story…

  14. 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.

  15. 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.

  16. Omnivory and resource - sharing in nutrient - deficient Rio Negro waters: stabilization of biodiversity? Omnivoria e repartição de recursos em águas pobres em nutrientes da Bacia do Rio Negro

    Directory of Open Access Journals (Sweden)

    Ilse Walker

    2009-09-01

    Full Text Available Amazonian biodiversity is notorious, this is also valid for the fauna of the mineral-deficient waters of the Rio Negro System. Some 25 years of research on the benthic fauna of Central Amazonian streams resulted in species-rich foodwebs with a high degree of omnivory within dense animal communities. To exemplify the taxonomic range of omnivorous consumers, the detailed resource spectra of 18 consumer species, including Protozoa (2 species, Platyhelminthes (1 species, insects (2 species, fish (6 species and shrimps (Decapoda, 7 species, associated primarily with the benthic habitats of Rio Negro tributaries, are presented. Special features of omnivory are characterized, and the importance of litter-decomposing fungi as essential energy input into the foodwebs is documented. It is shown that general omnivory -diverse omnivore consumers sharing most of the resource types- is a prevalent feature. The relevance of this general omnivory for the maintenance of biodiversity is discussed.A biodiversidade do Amazonas é notório e isto também é válido para as águas pobres em nutrientes da bacia do Rio Negro. Uma pesquisa de 25 anos da fauna béntica de igarapés da Amazônia Central resultou em redes alimentares caraterizadas por alta diversidade de espécies, por intensa omnivoria e por alta densidade populacional. Para demonstrar a generalidade taxonômica de omnivoria no bentos dos igarapés, são apresentados as listas de presas / recursos de 18 espécies de consumidores, sendo Protozoa (2 epécies, Platyhelminthes (1 espécie, insetos (2 espécies, peixes (6 espécies e camarões (Decapoda, 7 espécies. Diferentes categorias de omnivoria são apresentados, e a importância de fungos decompositores da liteira submersa como input básico de energia nas redes alimentares é demonstrada. É prevalente a omnivoria geral, sendo que as diferentes espécies omnívoros estão utilizando os mesmos recursos. Considera- se a relevância desta omnivoria geral

  17. A re-appraisal of the stratigraphy and volcanology of the Cerro Galán volcanic system, NW Argentina

    Science.gov (United States)

    Folkes, Christopher B.; Wright, Heather M.; Cas, Ray A.F.; de Silva, Shanaka L.; Lesti, Chiara; Viramonte, Jose G.

    2011-01-01

    From detailed fieldwork and biotite 40Ar/39Ar dating correlated with paleomagnetic analyses of lithic clasts, we present a revision of the stratigraphy, areal extent and volume estimates of ignimbrites in the Cerro Galán volcanic complex. We find evidence for nine distinct outflow ignimbrites, including two newly identified ignimbrites in the Toconquis Group (the Pitas and Vega Ignimbrites). Toconquis Group Ignimbrites (~5.60–4.51 Ma biotite ages) have been discovered to the southwest and north of the caldera, increasing their spatial extents from previous estimates. Previously thought to be contemporaneous, we distinguish the Real Grande Ignimbrite (4.68 ± 0.07 Ma biotite age) from the Cueva Negra Ignimbrite (3.77 ± 0.08 Ma biotite age). The form and collapse processes of the Cerro Galán caldera are also reassessed. Based on re-interpretation of the margins of the caldera, we find evidence for a fault-bounded trapdoor collapse hinged along a regional N-S fault on the eastern side of the caldera and accommodated on a N-S fault on the western caldera margin. The collapsed area defines a roughly isosceles trapezoid shape elongated E-W and with maximum dimensions 27 × 16 km. The Cerro Galán Ignimbrite (CGI; 2.08 ± 0.02 Ma sanidine age) outflow sheet extends to 40 km in all directions from the inferred structural margins, with a maximum runout distance of ~80 km to the north of the caldera. New deposit volume estimates confirm an increase in eruptive volume through time, wherein the Toconquis Group Ignimbrites increase in volume from the ~10 km3 Lower Merihuaca Ignimbrite to a maximum of ~390 km3 (Dense Rock Equivalent; DRE) with the Real Grande Ignimbrite. The climactic CGI has a revised volume of ~630 km3 (DRE), approximately two thirds of the commonly quoted value.

  18. Hydraulic model of the steam-lines network of the Cerro Prieto, B.C., geothermal field; Modelo hidraulico de la red de vaporductos del campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Salaices, E; Garcia, A; Martinez J I; Ovando, R; Cecenas, M; Hernandez A F [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: salaices@iie.org.mx; Canchola, I; Mora, O; Miranda, C; Herandez, M; Lopez, S; Murillo, I [Comision Federal de Electricidad, B.C (Mexico)

    2007-01-15

    The steam-line network of the Cerro Prieto geothermal field is composed of 184 wells, and 162 of the wells are integrated and connected by pipes. Thirteen power units, with an installed electrical capacity of 720 MW, are fed by that network. The network length is 120 km, including pipes of several diameters with branches and interconnections. The extension and complexity of the steam-line system make it difficult to analyze the transport and supply of steam to the power plants. For that it was necessary to have a tool capable of analyzing the system and the performance of the network as a whole, as well as the direction and flow volumes in each part of the system. In this paper, a hydraulic model of the Cerro Prieto steam-line network is presented. The model can determine the performance of the whole network by quantifying the pressure drops, flows and heat losses of the components. The model analyses the consequences of changes in operating conditions, steam production, maintenance activities and design (such as the integration of new wells). The model was developed using PIPEPHASE 9.0, a numeric simulator of multi-phase flow in steady state with heat transfer. It is used to model systems and pipe networks for steam- and condensate-transport. [Spanish] La red de vaporductos del campo geotermico de Cerro Prieto esta compuesta por un conjunto de 184 pozos, de los cuales 162 son pozos integrados, interconectados entre si a traves de una red de tuberias. Por medio de esta red se alimentan 13 unidades generadoras de electricidad con una capacidad total instalada de 720 MWe. La red tiene una longitud aproximada de 120 kilometros y esta compuesta por tuberias de diferentes diametros, ramales, interconexiones, etc. La complejidad y extension del sistema de vaporductos hace muy dificil el analisis del transporte y suministro de vapor a las plantas generadoras. Lo anterior creo la necesidad de contar con una herramienta que ayudara en el analisis del sistema con el fin de

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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)

  6. 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

  7. Eruptive history of the youngest Mexican Shield and Mexico's most voluminous Holocene eruption: Cerro El Metate

    Science.gov (United States)

    Oryaëlle Chevrel, Magdalena; Guilbaud, Marie-Noelle; Siebe, Claus

    2016-04-01

    Small to medium-sized shield volcanoes are an important component of many volcanic fields on Earth. The Trans-Mexican Volcanic Belt, one of the most complex and active continental arcs worldwide, displays a large number of such medium-sized volcanoes. In particular the Michoacán-Guanajuato Volcanic Field (MGVF) situated in central Mexico, is the largest monogenetic volcanic field in the world and includes more than 1000 scoria cones and about four hundred medium-sized volcanoes, also known as Mexican shields. The Mexican shields nevertheless represent nearly 70% of the total volume erupted since 1 Ma and hence played a considerable role in the formation of the MGVF. However, the source, storage, and transport as well as the physical properties (density, viscosity, volatile content, etc.) of the magmas involved in these eruptions remain poorly constrained. Here, we focus on Cerro El Metate, the youngest monogenetic andesite shield volcano of the field. New C14 dates for the eruption yield a young age (~AD 1250), which briefly precedes the initial rise of the Tarascan Empire (AD 1350-1521) in this region. This volcano has a minimum volume of ~9.2 km3 DRE, and its viscous lava flows were emplaced during a single eruption over a period of ~35 years covering an area of 103 km2. By volume, this is certainly the largest eruption during the Holocene in Mexico, and it is the largest andesitic effusive eruption known worldwide for this period. Such a large volume of lava erupted in a relatively short time had a significant impact on the environment (modification of the hydrological network, forest fires, etc.), and hence, nearby human populations probably had to migrate. Its eruptive history was reconstructed through detailed mapping, and geochemical and rheological analyses of its thick hornblende-bearing andesitic flows. Early and late flows have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by

  8. Noise reduction in steam-vent points at the Cerro Prieto geothermal field, BC; Reduccion del ruido en puntos de desfogue en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2008-01-15

    Steam silencers have been placed on the power units regulation system of the Cerro Prieto geothermal field, but not where the steam-pipes vent high-pressure steam (rupture disks). Moreover, the power-unit silencers are large and their abilities to reduce noise depend on an external, uncontrollable factor: pores sizes in the volcanic rocks they are made of. Thus a compact, economic and relatively easy to construct metallic silencer was designed to be used at several points of dry-steam venting to minimize the noise. The design was based on orifice-plate equations and a prototype was constructed and tested. It proved capable of reducing noise by 30 decibels for atmospheric discharges of primary steam at operating pressures. The size of the silencer can be adjusted to the particular needs of each vent case. [Spanish] En el campo geotermico de Cerro Prieto solo existen silenciadores de vapor en el sistema de regulacion de las plantas generadoras, pero no en los sitios de desfogue de vapor a alta presion en los vaporductos (discos de ruptura). Ademas, los silenciadores de las plantas son muy robustos y su capacidad de reduccion del ruido depende de un factor externo no controlable, como es el tamano del poro de la roca volcanica con el que estan construidos. Por lo tanto, se diseno un silenciador metalico compacto, economico y relativamente facil de fabricar, para utilizarse en diversos puntos de descarga de vapor seco a fin de minimizar el ruido. El diseno se realizo con base en las ecuaciones de la placa de orificio. Se construyo un prototipo cuyas pruebas demostraron que es capaz de reducir el ruido hasta en 30 decibeles, al descargar desde la presion de operacion de vapor primario hacia la presion atmosferica. Las dimensiones del silenciador pueden ajustarse a las necesidades particulares de cada caso de desfogue.

  9. Cost model for geothermal wells applied to the Cerro Prieto geothermal field case, BC Abstract; Modelo de costeo de pozos geotermicos aplicado para el caso del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Vaca Serrano, Jaime M.E [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: jaime.vaca@cfe.gob.mx

    2008-01-15

    A project for drilling geothermal wells to produce electrical energy can be defined as a sequence of plans to get steam or geothermal fluids to satisfy a previously known demand, and, under the best possible conditions, to obtain payment. This paper presents a cost model for nine wells drilled at the Cerro Prieto geothermal field in 2005 and 2006 to supply steam to the power plants operating in the field. The cost model is based on the well cost, the initial steam production, the annual decline of steam, the drilling schedule and the break-even point for each well. The model shows the cost of steam by the ton and the sale price needed to determine the discount rate and the investment return time. [Spanish] Un proyecto de perforacion de pozos geotermicos puede definirse como una secuencia o sucesion de planes para obtener vapor o fluidos geotermicos destinados a satisfacer una demanda previamente determinada, que se emplearan principalmente para generar energia electrica, bajo las mejores condiciones para obtener un pago. Este trabajo presenta un modelo de costeo para nueve pozos en el campo geotermico de Cerro Prieto, que fueron perforados entre 2005 y 2006 como parte del suministro de vapor para las plantas generadoras que operan en este campo. El modelo de costeo se basa en el costo por pozo, la produccion inicial de vapor, la declinacion anual de vapor, los intereses de las obras de perforacion y el punto de equilibrio para cada pozo. Los resultados permiten conocer el costo de la tonelada de vapor y el precio de venta para determinar la tasa de descuento y el tiempo de retorno de la inversion.

  10. Glaciares de Roca Fósiles y otras formas criogénicas en San Carlos de Bariloche, Río Negro Fossil rock glaciers and other criogenic forms in San Carlos de Bariloche, Río Negro

    Directory of Open Access Journals (Sweden)

    Fernando Pereyra

    2010-05-01

    Full Text Available La presencia de formas criogénicas en la región Andino-Patagónica constituye un rasgo distintivo de la geomorfología de la región. Se estudia un glaciar de roca localizado en la zona del Cerro Catedral. Se analizan sus principales características, génesis e implicancias paleoambientales. El sector considerado se ubica en el sector norte del filo Catedral (41°10´S / 71°27´O localizado al sudeste de la zona céntrica de San Carlos de Bariloche, aledaño a la Villa Catedral. Numerosos factores han coadyuvado para hacer posible la formación de este glaciar de roca: la presencia de un clima ligeramente más frío y más seco que actual y una importante proporción de afloramientos rocosos intensamente diaclasados y fácilmente meteorizables. Además, se suman la importante participación del proceso de congelifracción que actúo como principal abastecedor de materiales detríticos en un paisaje geomorfológicamente inestable debido a la rápida deglaciación; la altitud y presencia de cenizas volcánicas que incluyen materiales tamaño limo ya que han favorecido a la presencia de hielo intersticial permitiendo el movimiento del mismo.Criogenic landforms are distinctive features in the Patagonic Andes. A fossil rock glacier, located in Cerro Catedral Zone is studied. Main features, genesis and palaeoclimatic implicances are considered. Studied zone is located in Cerro Catedral northern sector (41°10´S / 71°27´O, south west of San Carlos de Bariloche city close to Villa Catedral. Ocurrence of rock glaciers in the area resulted of the combination of several factors such as a colder and lightly drier weather than the present climate and a high coarse debris availability due to weathered and jointly outcropping rocks. Congelifraction is the main weathering process that supplied the debris. Landscape features, like height and geomorphologically instability due to rapid deglatiation, were also remarkable factors. Siltysize cineritic

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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......

  16. Vulnerabilidad al ascenso del nivel del mar en la costa de la provincia de Río Negro

    Directory of Open Access Journals (Sweden)

    R.R. Kokot

    2004-09-01

    Full Text Available Los escenarios elaborados a escala mundial por el Panel Internacional de Cambio Climático (IPCC respecto al ascenso del nivel del mar, debido principalmente a la expansión térmica del océano y a las pérdidas de masa de los glaciares, prevén valores que en promedio oscilan entre 0,09 y 0,88 m desde 1990 al 2100, con tendencia a la aceleración. Los impactos potenciales por la elevación del mar conducen a cambios en el área costera, que incluyen inundación, incremento en el retroceso costero, e intrusión salina en los acuíferos y estuarios. Con el objeto de posibilitar un adecuado manejo de la costa de la provincia de Río Negro, se efectuó una zonificación que permite disponer de información referente a la vulnerabilidad por ascenso del nivel del mar, a través de un mapa de simple lectura. Las áreas de peligrosidad geológica, referidas a inundación permanente y/o episódica se identificaron mediante índices de vulnerabilidad costera, también denominados índices de susceptibilidad, obtenidos a través de la aplicación de un algoritmo que relaciona variables obtenidas a partir de información geológica costera, oceanográfica y climatológica. Las zonas más vulnerables al ascenso del nivel del mar, corresponden a Balneario El Salado (Playas Doradas, San Antonio Oeste - San Antonio Este, Caleta de los Loros y la desembocadura del río Negro, mientras que el tramo de costa correspondiente a la costa acantilada ubicada al oeste del río Negro y al sur de punta Pórfido, muestra una vulnerabilidad baja.

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. Cerro Colotlán: aproximación arqueo-lingüística para su estudio

    OpenAIRE

    Cabrero García, Ma. Teresa; Valiñas Coalla, Leopoldo

    2010-01-01

    Este trabajo se basa en los hallazgos arqueológicos y en los análisis etnohistórico y lingüístico hechos en la zona habitacional de Cerro Colotlán, cuyo centro ceremonial fue utilizado por los tepecanos hasta las primeras décadas del siglo XX. En las excavaciones realizadas al iniciar el año 2000 se descubrió un asentamiento más antiguo fechado entre 990 y 1275 d.C., con una arquitectura muy distinta a la de los restos de la superficie. Los análisis etnohistórico y lingüístico permiten postul...

  3. Evaluación integral del riesgo volcánico del Cerro Machín, Colombia

    OpenAIRE

    Leonel Vega Mora; Fernando Javier Díaz

    2013-01-01

    El volcán Cerro Machín (VCM) se encuentra situado en la Cordillera Central de Colombia. Por la com- posición química, magnitud y extensión de sus erupciones pasadas, se reconoce como un volcán explosivo de gran potencial de daño, cuya actividad futura podría afectar intensamente durante mucho tiempo (meses hasta años) una región muy estratégica para la economía del país, que cubre áreas pertenecientes a los departamentos de Tolima, Quindío, Valle del Cauca y Cundinamarca, en las cuales habita...

  4. Charnockitic ortho gneisses and mafic granulites of Cerro Olivo complex, proterozoic basement of SE Uruguay, Part 1: Geology

    International Nuclear Information System (INIS)

    Charnockitic ortho gneisses and mafic granulite s exposed in the Cerro Bori Block, in the center of Punta del Este terrain, were the first document occurrence of granulitic rocks from SE sector of the Uruguayan Shield. We present here their main geological features, with the purpose to suggest some petrologic and structural interesting problems for a future lithogeochemical, mineral chemistry, stable isotopes and fluid inclusion studies about these rocks. We propose some speculation form field-based studies considering a cognate magmatic origin of both kinds of rocks, previous to a homogeneous granulitic metamorphism. Some structural evidences indicate that after their uplift, these rocks were located on over thickened crust, at great to medium deepness. A cataclasis during anatexis and amphibolite-facies mineral association stabilization are common phenomena. Other evidences suggest a polycyclic character for the regional geologic evolution

  5. Curie point depth from spectral analysis of aeromagnetic data from Cerro Prieto geothermal area, Baja California, México

    Science.gov (United States)

    Espinosa-Cardeña, J. M.; Campos-Enriquez, J. O.

    2008-10-01

    Using aeromagnetic data acquired in the area from the Cerro Prieto geothermal field, we estimated the depth to the Curie point isotherm, interpreted as the base of the magnetic sources, following statistical spectral-based techniques. According to our results the Curie point isotherm is located at a depths ranging from 14 to 17 km. Our result is somewhat deeper than that obtained previously based only in 2-D and 3-D forward modeling of previous low-quality data. However, our results are supported by independent information comprising geothermal gradients, seismicity distribution in the crust, and gravity determined crustal thickness. Our results imply a high thermal gradient (ranging between 33 and 38 °C/km) and high heat flow (of about 100 mW/m 2) for the study area. The thermal regime for the area is inferred to be similar to that from the Salton trough.

  6. Results of the first order leveling surveys in the Mexicali Valley and at the Cerro Prieto field

    Energy Technology Data Exchange (ETDEWEB)

    de la Pena L, A.

    1981-01-01

    The results obtained from the third leveling survey carried out by the Direccion General de Geografia del Territorio Nacional (previously DETENAL) during November and December 1979 are presented. Calculations of the changes in field elevation and plots showing comparisons of the 1977, 1978, and 1979 surveys are also presented. Results from a second order leveling survey performed to ascertain the extent of ground motion resulting from the 8 June 1980 earthquake are presented. This magnitude ML = 6.7 earthquake with epicenter located 15 km southeast of the Guadalupe Victoria village, caused fissures on the surface, the formation of small sand volcanos, and the ejection of ground water in the vicinity of the Cerro Prieto field. This leveling survey was carried out between benchmark BN-10067 at the intersection of the Solfatara canal and the Sonora-Baja California railroad, and benchmark BN-10055 located at the Delta station.

  7. Estudio de la líqueno flora encontrada en el Cerro de Quininí, Tibacuy, Cundinamarca

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    Hormaza Francisco

    2000-12-01

    Full Text Available

    Se realizó un muestreo de la liquen o flora del cerro de Quininí, Tibacuy, Cundinamarca para estudiar las características morfológicas externas de los géneros de líquenes encontrados en el. A su vez se hizo la revisión bibliográfica acerca de dichos géneros, datando así la riqueza de líquenes en la zona con 8 géneros en total y con respecto al papel de bioindicadores se mostró el grado de intervención para el lugar.

  8. Los marsupiales (Mammalia del Mioceno Superior de la Formación Cerro Azul (Provincia de La Pampa, Argentina

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    Visconti, G.

    2000-04-01

    Full Text Available We describe the most complete South American marsupial association of Huayquerian Age (late Miocene. Specimens were recovered from several new localities of central and northern La Pampa province (central Argentina, at levels assignable to Cerro Azul Fm.: Bajo Giuliani, Quehué, Telén, El Guanaco, and Laguna Chillhué. Loessoid sediments studied from this formation are indicative of lacustrine deposits overlaid by eolian levels bearing evidences of pedogenesis. A study of these levels at each one of the new localities led to their correlation in an integrated profile of Cerro Azul Fm. This formation corresponds to «Epecuén Fm.», at least in Salinas Grandes de Hidalgo, and probably also to the upper levels of Arroyo Chasicá Fm. The studied marsupials are representative of almost all major lineages (orders of South American Neogene marsupials. The marmosine didelphid Zygolestes tatei sp. nov. differs from the type species of the genus in its larger size, unreduced third lower premolar, and in the less reduction of the metaconid in the last lower molar. Another marmosine, Thylamys pinei sp. nov., differs from other Marmosini in the twinning of the para- and metaconid in the lower molars, and in the wider talonid of the m4. The Monodelphini marmosines Thylatheridium hudsoni y T. dolgopolae are abundant in several localities of this formation; their study confirms close affinities between this genus and Monodelphis. The didelphines Hyperdidelphys pattersoni and an indeterminate species of Lutreolina are also represented by a few specimens. A mandibular fragment including part of the last molar may represent the oldest record of a Sparassocynidae in central Argentina. The Borhyaenidae and Thylacosmilidae (Sparassodonta are also recorded by a few, fragmentary specimens. Pliolestes venetus sp. nov. (Paucituberculata, Caenolestidae differs from the type species of the genus in its smaller size and in the larger, less displaced metaconid in the

  9. Constraining the Paleogene of South America: Magnetostratigraphy and paleoclimate proxy records from Cerro Bayo (Provincia de Salta, Argentina)

    Science.gov (United States)

    Hyland, E.; Cotton, J. M.; Sheldon, N. D.

    2012-12-01

    Records of rapid climatic and ecological shifts in the past are crucial for understanding global systems and for predicting future impacts of climate change. Transient and broad scale hyperthermal events during the Paleogene, such as the Paleocene-Eocene Thermal Maximum (PETM) and Early Eocene Climatic Optimum (EECO), have been studied extensively through both marine records and a significant terrestrial record from North America. Despite this, little evidence exists from the climatic and ecological histories of other major landmasses, which limits the effectiveness of global climate response predictions. Here we present an integrated paleoenvironmental reconstruction of the early Paleogene from a site in central South America (Cerro Bayo, Argentina), including a new magnetostratigraphic age model, pedological and sedimentological interpretation, whole rock geochemical climate proxies, isotopic environmental proxies, and microfloral assemblages. Cerro Bayo is a 235-meter terrestrial section that exposes the Tunal, Mealla, and Maiz Gordo Formations, and based on magnetostratigraphic interpolation spans roughly 58—50 Mya, including both the PETM and EECO events. These formations are composed primarily of reddish sandstone and siltstone, much of which exhibits features characteristic of a moderate degree of pedogenesis (i.e., Inceptisols and Alfisols). High-resolution climate proxies derived from paleosol geochemical compositions highlight rapid increases in mean annual temperature (>5°C) and precipitation (>300 mm yr-1) during the PETM, as well as more gradual increasing temperature and precipitation trends leading up to the EECO. Carbon isotope stratigraphy through the section also indicates a sizable negative excursion (~4‰) during the PETM, and generally positive isotopic trends during the early Eocene. Phytolith biostratigraphy also details changes in local vegetation composition during climatic events that corresponds to similar patterns seen in terrestrial

  10. Una fosa-vertedero de época vettona en el Cerro de la Mesa (Alcolea de Tajo, Toledo

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    Chapa Brunet, Teresa

    2013-06-01

    Full Text Available The existence of pits filled with earth, ashes, pottery fragments and fauna, usually known as ash pits, rubbish pits or dumps, has been recognized on many Second Iron Age settlements of the Spanish Northern Plateau, generally linked with Vaccean and Vettonian groups. However, its distribution should be extended to the west of the Southern Plateau and eastern Extremadura, as evidenced by the example of the Cerro de la Mesa village and indications coming from other western sites. We offer here a detailed study of part of a rubbish pit where certain domestic remains were withdrawn in connection with a new project of urbanisation of the Vettonian village held on the transition from the 3rd to the 2nd centuries BC.La existencia de fosas rellenas con tierra, cenizas, fragmentos cerámicos y fauna denominadas genéricamente como cenizales, basureros o vertederos, es un hecho bien conocido en la Meseta Norte durante la Segunda Edad del Hierro, vinculándose con los grupos Vacceos y Vettones. Sin embargo, su distribución debe ampliarse al occidente de la Meseta Sur y oriente extremeño, como se evidencia tanto en el Cerro de la Mesa como a través de indicios documentados en otros yacimientos más occidentales. Se presenta aquí un detallado estudio de un sector de la fosa que actuó como vertedero para la retirada de ciertos restos domésticos con ocasión de la reurbanización en profundidad del poblado vettón que tuvo lugar en la transición del siglo III al II a.C.

  11. 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...

  12. 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.

  13. Gêneros digitais: expandindo a comunicação no Movimento Negro da Paraíba

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    Mirian Mirian de Albuquerque Aquino Aquino

    2014-05-01

    Full Text Available Resumo: Investigar como o Movimento Negro do Estado da Paraíba se apropria dos gêneros digitais (e-mail, blog, redes sociais e etc. e usa-os na perspectiva de disseminar a informação étnico-racial é o objetivo deste trabalho. Entendemos que os gêneros digitais podem ser utilizados como um canal de comunicação e disseminação dessa informação para os grupos negros sociais e racialmente invisibilizados na atual sociedade da informação-conhecimento-aprendizagem, onde o preconceito, a discriminação e o racismo fazem parte do seu cotidiano. A abordagem qualitativa caracteriza-se como pesquisa interpretativa com potencial descritivo e exploratório. A pesquisa bibliográfica serviu para discutirmos sobre os conceitos, a construção das categorias teóricas e o discurso do sujeito coletivo. O universo da pesquisa foi o Movimento Negro Organizado da Paraíba e os sujeitos/participantes foram quatro integrantes vinculados ao Núcleo de Estudantes Negras e Negros da UFPB e a Organização de Mulheres Negras na Paraíba. Utilizamos a entrevista semiestruturada como instrumento para a coleta dos dados cuja análise recorremos a técnica do Discurso do Sujeito Coletivo (DSC que tem por base a Semiótica de Pierce e a Teoria das Representações Sociais. Os resultados mostraram que a ferramenta mais utilizada pelo MNOPB para veicular as informações é o e-mail. O uso do blog está associado à comunicação da informação étnico-racial apreendida pelo grupo. DIGITAL GENRES: EXPANDING COMMUNICATION IN THE BLACK MOVEMENT OF PARAIBA Abstract: Investigate how the Black Movement of Paraiba State appropriates gender digital (email, blog, social networks and so on. And uses them in view of disseminating information étnico-raciais is the goal of this work. It is understood that these digital genres can be used as a channel of communication and dissemination of such information to the socially invisible, in the current information society

  14. Diplomacia transfronteriza en tiempos de revolución: el Alto Río Negro iberoamericano, 1815-1820

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    Adilson Brito

    2015-06-01

    Full Text Available Estudia los impactos de la guerra de independencia en la frontera regional del Alto Río Negro, teniendo como objeto de análisis las múltiples conexiones existentes entre los habitantes de ambos lados de la imaginaria línea fronteriza. A partir de julio de 1817, la guerra de independencia en Venezuela cambió de coordenadas: las luchas entre patriotas republicanos y realistas, fieles a la restauración de Fernando VII, alcanzaron la extensa región de frontera, e influenciaron las dinámicas políticas y sociales locales, principalmente las relaciones transfronterizas entre ambos lados, lo que impactó en la vida cotidiana de las poblaciones y afectó la diplomacia entre las autoridades portuguesas e hispanoamericanas, tanto realistas como patriotas.

  15. De esclavos a ciudadanos y malentretenidos. Representaciones del negro en el discurso jurídico colombiano del siglo XIX

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    Martha Isabel Rosas Guevara

    2014-01-01

    Full Text Available Mediante una narrativa historiográfica elaborada a partir de textos legales, el pre - sente documento pretende interpretar las ausencias y presencias del negro en el discurso jurídico decimonónico producido una vez obtenida la independencia de España en los albores del siglo XIX. Teniendo en cuenta que la imaginación del Estado republicano representó un desafío para las elites criollas, las cuales —pese a predicar retóricamente la consolidación de una comunidad nacional basada en la igualdad y la democracia— construyeron una idea de Nación sobre los basamentos ideológicos coloniales, perpetuados en la repulsión elitista hacia la masa o plebe, lo que a la postre produjo su exclusión de la promisoria modernidad.

  16. De esclavos a ciudadanos y malentretenidos. Representaciones del negro en el discurso jurídico colombiano del siglo XIX

    Directory of Open Access Journals (Sweden)

    Martha Isabel Rosas Guevara

    2014-07-01

    Full Text Available Mediante una narrativa historiográfica elaborada a partir de textos legales, el presente documento pretende interpretar las ausencias y presencias del negro en el discurso jurídico decimonónico producido una vez obtenida la independencia de España en los albores del siglo XIX. Teniendo en cuenta que la imaginación del Estado republicano representó un desafío para las elites criollas, las cuales —pese a predicar retóricamente la consolidación de una comunidad nacional basada en la igualdad y la democracia— construyeron una idea de Nación sobre los basamentos ideológicos coloniales, perpetuados en la repulsión elitista hacia la masa o plebe, lo que a la postre produjo su exclusión de la promisoria modernidad.

  17. De reales promesas al olvido concertado: los negros de la Revolución Haitiana en la Nueva Granada

    Directory of Open Access Journals (Sweden)

    Jorge Victoria Ojeda

    2007-01-01

    Full Text Available El artículo aborda un tema poco conocido en la historia de la Revolución Haitiana, tras el conflicto de España con Francia, de 1793 a 1795, en Santo Domingo: en su intento de recuperar el occidente de La Española, la Corona hispana buscó la alianza con los líderes del movimiento de esclavos de la colonia francesa de Saint-Domingue. Con la pérdida de la guerra, los líderes negros fueron desalojados. Las tropas se dividieron en grupos, y uno de ellos fue enviado a Portobelo. Pero al igual que las demás tropas de Auxiliares, las de Portobelo en poco vieron materializadas las promesas de libertad, excepciones, goces y prerrogativas con las cuales el bando español las ganó de su lado

  18. Rescate y germinación in vitro de embriones inmaduros de cedro negro (Juglans neotropica Diels

    Directory of Open Access Journals (Sweden)

    Oscar Darío Quintero-García

    2012-01-01

    Full Text Available Embriones inmaduros de cedro negro (Juglans neotropica (Juglandaceae con 16 y 20 semanas de desarrollo fueron removidos asépticamente de los frutos y sembrados durante 60 días en los medios de cultivo MS (Murashige y Skoog, 1962, WPM (Lloyd y McCown, 1980 y DKW (Driver y Kuniyuki, 1984, sin reguladores de crecimiento. Se observó que embriones con 16 semanas de desarrollo no germinaron en los tres medios de cultivo; por el contrario, los embriones con 20 semanas de desarrollo presentaron una germinación de 100%. Se encontró un marcado efecto del medio en el crecimiento de los embriones, siendo el medio MS mejor (P < 0.05 que los medios DKW y WPM, debido a que en él los embriones presentaron mayor altura y proporción tallo/raíz para la obtención de plántulas completas.

  19. El tribunal de la Santa Inquisición y los negros esclavos en América

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    Rosas Navarro, Ruth Magali

    2003-12-01

    Full Text Available Black slaves in America related with the Inquisitorial tribune in multiple ways: as processed defendants, confiscated material goods, service within and outside the Holy Office's prisons, witnesses and plaintiffs of their masters. Regarding this last matter, one could say that the Holy Office became the Justice Tribune which dedfended these «ebony pieces» from their master's abuse.

    Los negros esclavos en América se relacionaron de múltiples maneras con el tribunal inquisitorial: como reos procesados, bienes materiales confiscados, servicio dentro y fuera de las cárceles del Santo Oficio, testigos y denunciantes de sus amos. En este último sentido, el Santo Oficio se convirtió en Tribunal de Justicia que defendió a estas «piezas de ébano» del maltrato de sus amos.

  20. Cuerpos intrusivos asociados a las mineralizaciones polimetálicas del depósito Cerro León, área del anticlinal El Tranquilo, Santa Cruz: evidencias geofísicas Intrusive bodies associated with the polymetallic mineralization of the Cerro León deposit, area of Cerro Tranquilo anticline, Santa Cruz: Geophysical evidence

    Directory of Open Access Journals (Sweden)

    G. A Peñalva

    2008-03-01

    Full Text Available Las características geológicas tales como presencia de cuerpos intrusivos y subvolcánicos someros básicos a intermedios y de las mineralizaciones con alto contenido de sulfuros del área del anticlinal El Tranquilo, son particulares y poco representadas en el macizo del Deseado. El depósito polimetálico vetiforme Cerro León presenta una signatura geoquímica-mineralógica que lo diferencia del clásico modelo epitermal de baja sulfuración característico del macizo del Deseado. Los datos aeromagnéticos del área del anticlinal El Tranquilo permiten reconocer una conspicua anomalía subcircular que se interpreta como un intrusivo no aflorante, de aproximadamente 9 km de diámetro, que subyace al Grupo El Tranquilo y a la Formación Roca Blanca; su profundidad se estima en 1400 m. Este cuerpo intrusivo genera el domamiento regional del anticlinal El Tranquilo y el fracturamiento radial asociado. La interpretación de la presencia de pequeños cuerpos intrusivos y subvolcánicos o apófisis alimentados por el cuerpo intrusivo mayor, asociados con anomalías magnéticas de menor diámetro y mayor gradiente, está confirmada por datos de perforación. Las principales vetas del depósito Cerro León se ubican asociadas espacialmente con los cuerpos intrusivos y subvolcanicos someros no aflorantes. Esto, sumado al alto contenido de sulfuros y la signatura geoquímica y mineralógica de las vetas, sugiere que posiblemente estén asociadas genéticamente a los cuerpos intrusivos subyacentes y circundantes, y permite utilizar este modelo como una herramienta de prospección para este tipo de depósitos.The geologic characteristics such as presence of basic to intermediate intrusive and subvolcanic bodies, and the mineralization with high sulfide content of the El Tranquilo anticline area are peculiar and poorly represented in the Deseado Massif. The Cerro León polymetallic deposit presents a geochemical and mineralogical signature that is

  1. Evidence of increasing risk of schistosomiasis among school-age children in municipality of Calatrava, Province of Negros Occidental, Philippines

    Institute of Scientific and Technical Information of China (English)

    Belizario VY Jr; Erfe JM; Naig JRA; Chua PLC

    2015-01-01

    Objective:To explore risk of school-age children being infected with schistosomiasis in selected villages in the municipality of Calatrava, province of Negros Occidental, Philippines. Methods:As part of the monitoring and evaluation of the helminth control program in the province of Negros Occidental, parasitological monitoring, through the use microscopy of stool samples processed using Kato-Katz technique, was conducted to describe the baseline and follow-up parasitological status of school-age children in 2010 and 2012, respectively. Seven villages from the municipality of Calatrava were selected as study sites.Results:During baseline assessment, only one case of schistosomiasis was reported from the village of Marcelo. During follow-up assessment, 32 cases (6.9%) of schistosomiasis were reported and the prevalence of moderate-heavy intensity infection was 1.3% in six villages. Among the seven villages included in the follow-up, Minapasuk had the highest prevalence at 14.6%, while San Isidro reported no case of schistosomiasis.Conclusions:Non-endemic villages, which have reported positive cases in school-age children, may need to be assessed for possible endemicity for schistosomiasis. Transmission of the disease may need to be determined in these villages through active parasitological and malacological surveillance. Other non-endemic villages adjacent to or share river networks with endemic villages in Calatrava may need to be explored for possible introduction of the disease, especially after typhoons and flooding. Establishing endemicity for schistosomiasis in these villages will help infected and at risk individuals to receive yearly treatment to reduce morbidities caused by this disease.

  2. Decree 343/012. Is regulated the servitude established by Decree-Law 10,383, on several lines of electricity conduction -150 KV to be built in the departments of Florida, Cerro Largo, Maldonado, Flores, San Jose and Tacuarembo

    International Nuclear Information System (INIS)

    This decree regulates the establishment of electricity conduction in Florida, Cerro Largo, Maldonado, Flores, San Jose and Tacuarembo towns. These electrical lines are necessary to provide the public service by UTE

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

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    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

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

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    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.

  5. 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

  6. 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...

  7. Composición, estructura y diversidad del cerro El Águila, Michoacán, México Composition, structure and diversity of the cerro El Águila, Michoacán, Mexico

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Zacarias-Eslava

    2011-09-01

    Full Text Available Se describe la composición, estructura y diversidad de la vegetación presente en el cerro El Águila, Michoacán. Se reconocieron fisonómicamente 5 tipos de vegetación y en cada uno se establecieron 16 parcelas circulares de 400 m² (3.2 ha para censar los individuos leñosos ≥ 10 cm d.a.p., con una parcela anidada de 100 m² (0.8 ha para los individuos entre 2.5 y 9.9 cm d.a.p. El muestreo incluyó 46 especies agrupadas en 33 géneros y 21 familias. Los bosques tropical caducifolio y de Quercus deserticola tuvieron los valores más bajos de altura promedio ( 11 m y área basal (> 40 m²/ha. La diversidad fue mayor en el bosque tropical caducifolio (S=23 y α =5.4 y menor en el de Quercus-Pinus (S= 13 y α= 2.71. En general, los tipos de vegetación mostraron diferentes especies dominantes y una alta diversidad beta. La composición y estructura de estas comunidades puede asociarse a cambios en altitud y a la perturbación por actividades humanas. No obstante, la zona de estudio aún presenta áreas en buen estado de conservación, particularmente los bosques templados hacia las zonas con mayor altitud, por lo que se sugiere que en un futuro cercano sea incluida dentro de alguna categoría de protección estatal.This study describes composition, structure and diversity of vegetation in the Cerro El Águila, Michoacán. Five plant communities were recognized and for each one all woody individuals ≥10 cm DBH were tallied in sixteen 400 m² circular plots, whereas individuals between 2.5 and 9.9 cm DBH were measured in a 100 m² circular sub-plot centered within each larger plot. A total of 46 species, 33 genera and 21 families were recorded. The tropical deciduous forest and Quercus deserticola forest had low values of mean plant height ( 11 m and basal area (> 40 m²/ha. Diversity was greater in the tropical deciduous forest (S= 23 and α= 5.4, respectively and lower in the oak-pine forest (S= 13 and α= 2.71. All communities displayed

  8. Mineralogy of the silica-epidote mineralized zone (SEMZ) in the Cerro Prieto geothermal reservoir, B.C., Mexico; Mineralogia de la zona mineralizada de silice-epidota (ZMSE) del yacimiento geotermico de Cerro Prieto, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Georgina; Aragon, Alfonso; Portugal, Enrique; Arellano; Victor M [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: gim@iie.org.mx; Leon, Jesus de; Alvarez, Julio [Comision Federal de Electricidad, B.C. (Mexico)

    2006-07-15

    The distribution of hydrothermal minerals, mineral assemblages and fluid inclusion data were taken from drill cuttings from the production zone of wells all over the Cerro Prieto geothermal field. The production zone has been termed the silica-epidote mineralized zone (SEMZ), and is located in the deep part of the gray shale where thick layers of sandstone are found. Common mineral assemblages show three temperature ranges in the SEMZ: <200 degrees Celsius, 200-250 degrees Celsius and 250-300 degrees Celsius. The first range is characterized by clays, calcite and quartz; the second by quartz, epidote, chlorite and mica, and the third by epidote, amphibole, illite and chlorite. The study of fluid inclusions in authigenic grain quartz has shown two-phase fluid inclusions (liquid + vapor) of different salinities. A wide range exists of homogenization temperatures (Th) and for some wells there is a good agreement between Th and direct temperature measurements. [Spanish] Se determino la distribucion de minerales hidrotermales y las asociaciones parageneticas y se realizo el estudio microtermometrico de inclusiones fluidas a partir de recortes de perforacion de pozos de las distintas areas del campo geotermico de Cerro Prieto. Las muestras de recortes y nucleos de perforacion estudiados provienen de la zona de produccion a la que se le ha denominado Zona Mineralizada de Silice-Epidota (ZMSE), que se encuentra en la parte profunda de la lutita gris con importantes horizontes de areniscas. En esta zona las asociaciones parageneticas mas comunes han mostrado tres intervalos de temperatura para la ZMSE: <200 degrees Celsius, 200-250 degrees Celsius, 250-300 degrees Celsius. El primer intervalo esta caracterizado principalmente por arcillas, calcita y cuarzo; el segundo por cuarzo, epidota, clorita y micas, y el tercero por epidota, anfiboles, illita y clorita. El estudio de inclusiones fluidas en fragmentos de cuarzo autigenico mostro la presencia de inclusiones de dos fases

  9. Studies for recovering injection capacity in wells of the Cerro Prieto, BC, geothermal field; Estudios para recuperar la capacidad de aceptacion en pozos inyectores del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Rosales, Julio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: julio.alvarez@cfe.gob.mx

    2010-01-15

    As in geothermal fields around the world, at Cerro Prieto geothermal field, Baja California, former exploratory and production wells are used to inject residual brine. Since the 1980s, studies and activities have been carried out to find ways to recharge the reservoir and dispose of brine without harming the environment or underground aquifers. These include infiltration and cold-and-hot injection. Some of the studies are presented here, including analyses of litho-facies; core samples; pressure, temperature and spinner logs; well tests and injection rates-plus some studies on the shallow aquifer. All have been useful in fulfilling requirements made by environmental authorities. Because injection rates constantly decrease due to formation damage, it is proposed an additional technique be used to reduce such damages and prolong the lifetime of cold-and-hot injection wells-while ensuring the environment and shallow aquifers are not affected. [Spanish] Al igual que en diversos campos geotermicos en el mundo, en el de Cerro Prieto, Baja California se han utilizado tanto pozos inyectores perforados ex profeso como antiguos pozos exploratorios y productores para inyectar el fluido residual al subsuelo. Desde la decada de los 80 se han realizado diversos estudios y acciones en ese campo geotermico para recargar al yacimiento y para disponer del fluido residual, sin ocasionar danos al ambiente ni a los cuerpos hidricos del subsuelo, que van desde la infiltracion hasta la inyeccion en frio y en caliente. Este articulo presenta los diferentes estudios realizados con ese objetivo en el campo, incluyendo el analisis de litofacies, de nucleos de formacion, de registros de presion, temperatura y spinner, las pruebas en pozos y analisis de tasas de aceptacion, asi como los efectuados en el acuifero superficial. Todos ellos han sido de utilidad para atender los requerimientos de las autoridades ambientales. Finalmente, y en virtud de que las tasas de aceptacion de los pozos

  10. Two-phase characteristics of the feeding fluid of Cerro Prieto IV wells (Mexico) obtained by gas equilibrium; Caracteristicas bifasicas del fluido de alimentacion de pozos de Cerro Prieto IV (Mexico), obtenidas por equilibrio gaseoso

    Energy Technology Data Exchange (ETDEWEB)

    Barragan-Reyes, Rosa Maria; Arellano-Gomez, Victor Manuel; Portugal-Marin, Enrique [Instituto de Investigaciones Electricas (Mexico); De Leon-Vivar, Jesus [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)

    2008-10-15

    The gas composition of fluids produced by CP IV geothermal wells from the Cerro Prieto field was studied in order to identify different types of fluids entering the wells by estimating their temperature and excess steam. A method based on the Fischer Tropsch reaction and H2S equilibrium with pyrite-pyrrhotite as mineral buffer (FTHSH3) was used. The results for the reservoir natural state indicated the presence of fluids with heterogeneous reservoir temperature (between 275 and 310 degrees Celsius) and excess steam values, which were found from negative (boiled liquid that has lost steam when flowing to the well) to one (steam phase with zero liquid saturation). The study for individual wells in which boiling processes were identified, showed that through time, the feeding fluids consist of a two-phase mixture with different liquid/steam proportions. Also, the results suggested that a steam phase could occur at CP IV which is added to the feeding fluid, depending on the operation conditions of the wells. The origin of this steam could be the boiling of the deeper liquid due to a pressure drop. [Spanish] Se estudio la composicion gaseosa de los fluidos producidos por pozos geotermicos del sector CP IV del campo de Cerro Prieto para tratar de distinguir aportes de fluidos diferentes mediante la estimacion de su temperatura de yacimiento y del exceso de vapor. Se utilizo un metodo de equilibrio gaseoso basado en la reaccion de Fischer Tropsch y el equilibrio combinado pirita-pirrotita (FT-HSH3). Los resultados obtenidos indican que en el estado inicial del yacimiento existen fluidos que muestran heterogeneidad en los valores de temperatura de yacimiento (entre 275 y 310 grados Celsius), asi como en el exceso de vapor con valores desde negativos (liquido que despues de ebullir ha perdido vapor en su trayecto hacia el pozo) hasta uno (vapor con cero saturacion de liquido). El estudio individual de los pozos con fenomenos de ebullicion muestra que a traves del tiempo

  11. Geological and production analyses focused on exploration of the eastern part of the Cerro Prieto geothermal field, BC; Analisis geologico-productivo enfocado a la exploracion de la parte oriental del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Dumas, Alvaro [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)]. E-mail: alvaro.aguilar@cfe.gob.mx

    2008-01-15

    The eastern part of the Cerro Prieto geothermal field (CGCP), known as Poligono Nuevo Leon, is an area with proven geothermal resources, as confirmed by seven directional wells located toward the east and by vertical well M-200 located inside the polygon. Well M-200 was drilled in 1984 and has produced about 4 million tons of steam to date. It is integrated into the CP-2 sector, producing 68 t/h of steam. Presently the eastern part of CGCP, representing 25% of the total field area, is producing over half of the steam for the entire field. In the last few years, the steam has come only after increasing the number of production wells located in the eastern zone of CGCP (Rodriguez, 2006), where pressure, enthalpy and temperature conditions are better than in other parts of the field. However in the long term it will be necessary to incorporate Poligono Nuevo Leon into the productive area to expand the productive life of CGCP. This paper includes a geological analysis, plus models for steam production, temperature and enthalpy for Poligono Nuevo Leon. [Spanish] La parte oriental del Campo Geotermico de Cerro Prieto (CGCP), conocida como Poligono Nuevo Leon, representa una area potencial con recursos geotermicos comprobados, lo que demuestran siete pozos direccionales que se han perforado hacia el este, asi como el pozo vertical M-200, localizado dentro del poligono. El pozo M-200 se perforo en 1984 y ha producido a la fecha alrededor de 4 millones de toneladas de vapor, estando integrado al sector CP-2 una produccion de 68 t/h de vapor. Actualmente la parte oriental del CGCP, que representa el 25% del area total del campo, produce mas de la mitad del total de vapor del campo. El suministro de vapor en los ultimos anos se ha logrado cubrir aumentando el numero de pozos en operacion localizados en la zona oriente del CGCP (Rodriguez, 2006), ya que es aqui donde hay condiciones de presion, entalpia y temperatura del yacimiento que son mejores que en otras areas del campo

  12. The rules of urban planning and administrative responsibilities in protecting to the vulnerability and risk of Cerro Tapezco in Santa Ana

    International Nuclear Information System (INIS)

    An analysis of regulation is made of land use and administrative management of the Cerro Tapezco to show that as the years have passed it has been verified that the Costa Rican law on town planning has been inadequate for current problems due to lack of updating of various scientific and technical sources also dispersion and proliferation of competences of administrative authorities. The physical setting and planning rules is identified for CerroTapezco and surrounding towns. Local actions are explored in the elaboration of improvement and reform of the regulatory plan of Santa Ana. The administrative entities and institutions with competence in the development and implementation of plans have been identified, assessing deficiencies, inconsistencies and administrative omissions in urban planning of the city of Santa Ana and recommending changes necessary for the proper application of the Costa Rican law

  13. Effects of the Cerro Grande Fire (Smoke and Fallout Ash) on Soil Chemical Properties Within and Around Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, P.R.; Velasquez, W.R.; Naranjo, L. Jr.

    2000-11-01

    Soil surface (0- to 2-in. depth) samples were collected from areas within and around Los Alamos National Laboratory (LANL) just after the Cerro Grande fire, analyzed for radionuclides, radioactivity, and trace elements (heavy metals), and compared to soil samples collected in 1999 from the same sites. In addition, many types of organic substances (volatile and semivolatile organic compounds, organochlorine pesticides, polychlorinated biphenyls, high explosives, and dioxin and dioxin-like compounds) were assessed in soils from LANL, perimeter, and regional sites after the fire. Results show that impacts to regional, perimeter, and on-site (mesa top) areas from smoke and fallout ash as a result of the Cerro Grande fire were minimal.

  14. Evaluation of the Cerro Solo nuclear ore, province of Chubut. Geological characteristics of the deposit and of the basin. Pt. 2

    International Nuclear Information System (INIS)

    The Cerro Solo uranium ore deposit, is located 420 km west from Trelew city, Chubut province, in the extra-andean. The geologic environment belongs to the northwest edge portion of the intracratonic San Jorge Gulf Basin. The uraniferous district is named Pichinanes Ridge district. The mineralization lies 25 to 130 m depth, and is hosted by Los Adobes formation aged Aptian-Albian, made up by conglomerates, sandstones, coarse-sandstones and less abundant siltstones and claystones. The Cerro Solo ore deposit that belongs to the sandstone type-uranium occurrences are lenticular or tabular shaped, associated with organic material and pyrite, generally roughly parallel to the bedding (Trend-Type). The uranium minerals are uraninite and coffinite associated with organic material and pyrite, and frequently hematite, goethite, calcite, siderite and barite are observed. (Author)

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. Detecção de tracoma e doenças corneanas em índios da região do Alto Rio Negro

    Directory of Open Access Journals (Sweden)

    Reis Ana do Carmo Paula Pessoa dos

    2002-01-01

    Full Text Available Objetivo: Avaliar as condições oftalmológicas da população indígena do Alto Rio Negro, fronteira do Brasil com a Colômbia. Métodos: Exame oftalmológico de 179 índios habitantes do Rio Tiquié, afluente do Rio Negro, em julho de 1999. Resultado: Opacidades numulares corneanas 28,5%; pterígio 12,8%; tracoma 55%. Do total de índios examinados 2,8% apresentavam visão inferior a contar dedos a 5 metros, devido a lesões corneanas secundárias ao tracoma.

  20. Istorinės ir kultūros asmenybės negrožinėje lietuvių prozoje vaikams

    OpenAIRE

    Maskuliūnienė, Džiuljeta

    2009-01-01

    Straipsnyje analizuojama XIX–XXI a. negrožinė lietuvių vaikų proza, vaizduojanti istorines ir kultūros asmenybes. Iškeliama svarbi tokių tekstų teorinė problema: faktinio, dokumentinio ir meninio vaizdavimo sampyna. Chronologiškai apžvelgiama negrožinės lietuvių vaikų prozos raida. Jos ištakomis laikytini Motiejaus Valančiaus hagiografiniai tekstai. Tačiau iš esmės populiarinti tam tikrus asmenis pradėta daug vėliau, kai rašyti ėmė pozityvistiškai nusiteikę autoriai (Petras Vileišis, Šatrijos...

  1. Pucarilla-Cerro Tipillas volcanic complex: the oldest recognized caldera in the southeastern portion of central volcanic zone of Central Andes?

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, Silvina; Petrinovic, Ivan [CONICET -IBIGEO. Museo de Cs. Naturales, Universidad de Salta, Mendoza 2 (4400), Salta (Argentina)], E-mail: guzmansilvina@gmail.com

    2008-10-01

    We recognize the most eastern and oldest collapse caldera structure in the southern portion of the Central Volcanic Zone of the Andes. A description of Middle-Upper Miocene successions related to explosive- effusive events is presented. The location of this centre close to Cerro Galn Caldera attests a recurrence in the volcanism between 12 and 2 Ma in this portion of the Altiplano - Puna Plateau.

  2. Moche social boundaries and settlement dynamics at Cerro Castillo (c. AD 600-1000), Nepeña Valley, Peru Volume 1

    OpenAIRE

    Rengifo, Carlos

    2014-01-01

    This dissertation explores the pre-Columbian occupation at Cerro Castillo, a coastal settlement in the Nepeña Valley, Peru. The study examines the site’s internal organisation as well as its relationship with regional cultural phenomena during its most important period of occupation (circa AD 600-1000). Characterising the Moche presence at the site is one of the main subjects of this investigation. Moche was one of the grandest civilisations that developed in the pre-Columbian ...

  3. Cerro Grande Fire Impact to Water Quality and Stream Flow near Los Alamos National Laboratory: Results of Four Years of Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    B.M. Gallaher; R.J. Koch

    2004-09-15

    In May 2000, the Cerro Grande fire burned about 7400 acres of mixed conifer forest on the Los Alamos National Laboratory (LANL), and much of the 10,000 acres of mountainside draining onto LANL was severely burned. The resulting burned landscapes raised concerns of increased storm runoff and transport of contaminants by runoff in the canyons traversing LANL. The first storms after the fire produced runoff peaks that were more than 200 times greater than prefire levels. Total runoff volume for the year 2000 increased 50% over prefire years, despite a decline in total precipitation of 13% below normal and a general decrease in the number of monsoonal thunderstorms. The majority of runoff in 2000 occurred in the canyons at LANL south of Pueblo Canyon (70%), where the highest runoff volume occurred in Water Canyon and the peak discharge occurred in Pajarito Canyon. This report describes the observed effects of the Cerro Grande fire and related environmental impacts to watersheds at and near Los Alamos National Laboratory (LANL) for the first four runoff seasons after the fire, from 2000 through 2003. Spatial and temporal trends in radiological and chemical constituents that were identified as being associated with the Cerro Grande fire and those that were identified as being associated with historic LANL discharges are evaluated with regard to impacts to the Rio Grande and area reservoirs downstream of LANL. The results of environmental sampling performed by LANL, the New Mexico Environment Department (NMED), and U.S. Geological Survey (USGS) after the Cerro Grande fire are included in the evaluation. Effects are described for storm runoff, baseflow, stream sediments, and area regional reservoir sediment.

  4. Evaluación integral del riesgo volcánico del Cerro Machín, Colombia

    Directory of Open Access Journals (Sweden)

    Leonel Vega Mora

    2013-01-01

    Full Text Available El volcán Cerro Machín (VCM se encuentra situado en la Cordillera Central de Colombia. Por la com- posición química, magnitud y extensión de sus erupciones pasadas, se reconoce como un volcán explosivo de gran potencial de daño, cuya actividad futura podría afectar intensamente durante mucho tiempo (meses hasta años una región muy estratégica para la economía del país, que cubre áreas pertenecientes a los departamentos de Tolima, Quindío, Valle del Cauca y Cundinamarca, en las cuales habitan cerca de un millón de personas. En este artículo se muestra la metodología y resultados del estudio de “Evaluación Integral del Riesgo del Cerro Machín – Colombia”, realizado durante 2009 por el Grupo PIGA de Investigación en Política, Información y Gestión Ambiental de la Facultad de Ingeniería de la Universidad Nacional de Colombia, tomando como punto de partida el estudio de “Evaluación de la Amenaza Volcánica Potencial del Cerro Machín” adelantado en el 2002 por el Servicio Geológico Colombiano (SGC. En consecuencia, se genera y ajusta una nueva ecuación para la determinación del riesgo, basada en la valoración de índices de amenaza intrínseca e índices de vulnerabilidad, los primeros en función del grado de intensidad, duración, extensión y acumulación de las amenazas, y los segundos, en función del grado de exposición espacial y temporal de los elementos (sociales, económicos, institucionales y ecosisté- micos y de su capacidad de respuesta intrínseca y extrínseca ante las amenazas. Con estas ecuaciones y mediante el uso de sistemas de información geográfica (SIG, se realiza para cada escenario de análisis considerando la modelación geoespacial del riesgo a nivel de cada pixel cartográfico del área territorial de estudio. En esta modelación se integra toda la informa- ción territorial del área en estudio, lo que permite obtener, de acuerdo con el marco lógico de evaluación preestablecido

  5. 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.

  6. 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.

  7. 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.

  8. Calidad nutricional y consumo de morera (Morus alba, ramio (Bohemeria nivea (L Gaud y sorgo negro forrajero (Sorghum almum en cabras

    Directory of Open Access Journals (Sweden)

    Jorge Elizondo Salazar

    2004-01-01

    Full Text Available Calidad y consumo de morera (Morus alba, ramio (Bohemeria nivea (L Gaud y sorgo negro forrajero (Sorghum almum en cabras. El experimento se llevó a cabo en la Estación Experimental Alfredo Volio Mata de la Universidad de Costa Rica. Se evaluó y comparó el consumo de morera, ramio y sorgo negro forrajero en nueve cabras raza La Mancha, con un peso promedio de 38 (±1 kg, distribuidas en un diseño de cuadrado latino 3 x 3 repetido. Los tratamientos experimentales fueron: a dieta única de morera, b dieta única de ramio y c dieta única de sorgo negro. La morera con una edad de rebrote de 90 días, el ramio con 56 días y el sorgo negro con 70 días. El forraje se suministró en forma fresca picada (tallos y hojas. Se recolectaron muestras del material ofrecido y rechazado para el análisis de materia seca, proteína cruda y fibra neutro detergente. Se observaron diferencias altamente significativas (P≤0,01 para el consumo de forraje fresco, materia seca, proteína cruda y fibra neutro detergente. La ingesta de materia seca para los diferentes tratamientos se encontró dentro del rango reportado en la literatura, siendo de 1,94, 0,97 y 0,90 del peso vivo respectivamente. Con los consumos de proteína cruda obtenidos con la dieta de morera y ramio, los animales cubrieron sus necesidades de mantenimiento y suplieron el nutrimento de forma extra para alcanzar ganancias de peso diarias superiores a los 50 gramos. La dieta que presentó los mayores niveles de consumo de forraje verde, forraje seco, proteína cruda y fibra neutro detergente fue la correspondiente a morera, seguida de la dieta de ramio.

  9. Primer registro de Acerophagus griseus (Hymenoptera: Encyrtidae como parasitoide de Pseudococcus viburni (Hemiptera: Pseudococcidae en el Alto Valle de Río Negro, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel A. AQUINO

    2013-01-01

    Full Text Available Se cita por primera vez la presencia de Acerophagus griseus (De Santis (Hymenoptera: Encyrtidae como parasitoide de ninfas y adultos de Pseudococcus viburni (Signoret (Hemiptera: Pseudococcidae y se registra la zona de Alto Valle de Río Negro como nuevo registro de distribución en Argentina. Se brinda una diagnosis y se ilustran los caracteres morfológicos de A. griseus.

  10. Doença de Tay-Sachs em criança de raça negra Tay-Sachs disease in a Negro child

    Directory of Open Access Journals (Sweden)

    Sérgio Rosemberg

    1970-12-01

    Full Text Available É relatado um caso de doença de Tay-Sachs em criança da raça negra. O encontro desta entidade em indivíduos não judeus é bastante raro, sendo este o quinto caso descrito em criança negra. Os autores estudam alguns aspectos genéticos, chegando à conclusão de que o cálculo da freqüência do gene mutante é impossível devido ao pequeno número de casos e ao fato de que não há estimativas seguras quanto à taxa de nascimento de indivíduos negros na população, Em que pese o fato de o diagnóstico se assentar em bases puramente clínicas e anatômicas, prescindindo os autores de exames bioquímicos específicos, os dados apresentados são congruentes com os casos clássicos descritos na literatura.A case of Tay-Sachs diseases in a Negro child is reported. The occurrence of this disease in non-Jewish individuals is very rare and this is the fifth case of a Negro-child reported in the litterature. Some genetical aspects are studied and the authors conclude that the frequency calculation of the mutant gene is impossible due to the small number of cases and to the fact that there is reliable information regarding the rate of birth of Negro individuals in the general population. The diagnosis was based on ophtalmological and clinical data. No specific biochemical tests were performed but the data obtained are congruent with other cases reported in the litterature.

  11. Régimen de acceso al dominio de la tierra pastoril en Río Negro y Neuquén

    OpenAIRE

    Fernández, Juan Carlos

    2015-01-01

    En el presente trabajo se describen breve pero sistemáticamente las prácticas y normas generalmente aplicadas para lograr el acceso a la tierra de uso ganadero extensivo en las provincias de Río Negro y Neuquén, considerando a tal fin los problemas comúnmente generados con ocasión de la modificación de la titularidad del fundo agrario.

  12. Análisis litoestratigráfico de la Formación Cerro Azul (Mioceno Superior en la provincia de La Pampa

    Directory of Open Access Journals (Sweden)

    Graciela Visconti

    2010-10-01

    Full Text Available La Formación Cerro Azul fue definida en 1980 para incluir a las sedimentitas continentales pliocenas (limolitas arenosas y areniscas limosas que afloran de manera discontinua en casi todo el ámbito de la provincia de La Pampa. No obstante, varias investigaciones paleontológicas realizadas a partir de la segunda mitad de la década del 80' han permitido ubicar geocronológicamente a la unidad en el intervalo 10 Ma a 5,8-5,7 Ma. El objetivo del trabajo es realizar un análisis de las características litoestratigráficas de la Formación Cerro Azul de acuerdo al Código Argentino de Estratigrafía. Se propone un lectoestratotipo para la unidad, consistente en el perfil de Algarrobo del Águila y un perfil auxiliar en cerro El Morro. También se establecieron las relaciones estratigráficas con otras formaciones. Se interpreta un paleoambiente depositacional de llanura, donde alternan depósitos de loess con numerosos paleosuelos, detectándose escasos depósitos lacustres en la base y pocos cursos fluviales.

  13. Geographic Information System (GIS) Emergency Support for the May 2000 Cerro Grande Wildfire, Los Alamos, New Mexico, USA

    Energy Technology Data Exchange (ETDEWEB)

    C.R.Mynard; G.N.Keating; P.M.Rich; D.R. Bleakly

    2003-05-01

    In May 2000 the Cerro Grande wildfire swept through Los Alamos, New Mexico, burning approximately 17,400 ha (43,000 acres) and causing evacuation of Los Alamos National Laboratory (LANL) and the communities of Los Alamos and White Rock. An integral part of emergency response during the fire was the use of geographic information system (GIS) technology, which continues to be used in support of post-fire restoration and environmental monitoring. During the fire Laboratory GIS staff and volunteers from other organizations worked to produce maps and provide support for emergency managers, including at an emergency GIS facility in Santa Fe. Subsequent to the fire, Laboratory GIS teams supported the multiagency Burned Area Emergency Rehabilitation (BAER) team to provide GIS data and maps for planning mitigation efforts. The GIS teams continue to help researchers, operations personnel, and managers deal with the tremendous changes caused by the fire. Much of the work is under the auspices of the Cerro Grande Rehabilitation Project (CGRP) to promote recovery from fire damage, improve information exchange, enhance emergency management, and conduct mitigation activities. GIS efforts during the fire provided important lessons about institutional matters, working relationships, and emergency preparedness. These lessons include the importance of (1) an integrated framework for assessing natural and human hazards in a landscape context; (2) a strong GIS capability for emergency response; (3) coordinated emergency plans for GIS operations; (4) a method for employees to report their whereabouts and receive authoritative information during an evacuation; (5) GIS data that are complete, backed-up, and available during an emergency; (6) adaptation of GIS to the circumstances of the emergency; (7) better coordination in the GIS community; (8) better integration of GIS into LANL operations; and (9) a central data warehouse for data and metadata. These lessons are important for planning

  14. Influência de Negro de Fumo Modificado com Polianilina na Estrutura de Compósitos com Poli(Fluoreto de Vinilideno

    Directory of Open Access Journals (Sweden)

    Zucolotto Valtencir

    2002-01-01

    Full Text Available Compósitos condutores elétricos a base de poli(fluoreto de vinilideno (PVDF e negro de fumo modificado com polianilina (Eeonomer® foram preparados através do processamento por fusão. Resultados de reometria de torque indicaram que a presença de polianilina no negro de fumo é vantajosa ao processamento por fusão, reduzindo a viscosidade do fundido em comparação com a aditivação com negro de fumo puro. Compósitos contendo acima de 5% em peso de Eeonomer® apresentaram condutividade da ordem de 10-2 S/cm. Esse valor se manteve estável mesmo após tratamento térmico a 150degreesC por 170 h em atmosfera ambiente. Análises por calorimetria diferencial de varredura (DSC e difração de Raios-X mostraram que o tipo e a quantidade de Eeonomer®, assim como a taxa de resfriamento da amostra, podem afetar a temperatura de fusão, o grau de cristalinidade e a fase cristalina do PVDF presente no compósito.

  15. 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...

  16. 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...

  17. 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...

  18. 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

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

    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

  20. El Silúrico de la sierra de La Invernada, Precordillera de San Juan: implicancias estratigráficas y paleogeográficas

    Directory of Open Access Journals (Sweden)

    Silvio H Peralta

    2013-12-01

    Full Text Available En el flanco oriental de la sierra de La Invernada, Precordillera Central de San Juan, aflora una sucesión marino-clástica del Ordovícico Superior-Silúrico, asignada al Grupo Tucunuco, integrada por las formaciones La Chilca, su equivalente lateral Los Bretes (Hirnantiano?-Wenlockiano temprano, y la Formación Los Espejos (Wenlockiano medio-Ludowiano, con espesores variables entre 150 m y 220 m. Esta sucesión yace en discordancia erosiva (paraconcordancia, sobre calizas de la Formación San Juan (Ordovícico temprano, y es cubierta en paraconcordancia por depósitos devónicos de la Formación Punta Negra. En el área de Gualilán, la Formación La Chilca está representada por una sucesión de pelitas y areniscas estrato-granocreciente, que hacia el sur cambian a facies de pelitas bioturbadas formalmente denominadas en este trabajo Formación Los Bretes (nom.nov (="Facies Pachaco de la Formación Tambolar", cuyo estrato-tipo se propone en el cerro Blanco de Pachaco. La Formación Los Espejos sobreyace en paraconcordancia a la Formación La Chilca, presenta arreglo estrato-granocreciente, con pelitas transgresivas a la base, vaques, acumulaciones bioclásticas y estructuras de deformación sinsedimentaria en la parte superior. La Formación Los Espejos no aflora en Pachaco, pero sus depósitos se encuentran resedimentados en olistostromas del Devónico. Los depósitos silúricos del área de estudio muestran posición relativa distal, respecto a sus equivalentes de la Precordillera Central. El cambio de facies de la Formación La Chilca y ausencia de la Formación Los Espejos, se interpreta como resultado del basculamiento de la cuenca silúrica hacia el norte debido al control estructural del Alto del Tambolar.

  1. 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.

  2. The Cerro Bitiche Andesitic Field: petrological diversity and implications for magmatic evolution of mafic volcanic centers from the northern Puna

    Science.gov (United States)

    Maro, Guadalupe; Caffe, Pablo J.

    2016-07-01

    The Cerro Bitiche Andesitic Field (CBAF) is one of the two largest mafic volcanic fields in northern Puna (22-24° S) and is spatially and temporally associated with ignimbrites erupted from some central Andean Altiplano-Puna Volcanic Complex calderas. The CBAF comprises seven scoria cones and widespread high-K calcalkaline lava flows that cover an area of 200 km2. Although all erupted rocks have a relatively narrow chemical range (56-62 % SiO2, 3-6 % MgO), there is a broad diversity of mineral compositions and textures. The least evolved lavas (˜58-61 % SiO2) are high-Mg andesites with scarce (<10 %) microphenocrysts of either olivine or orthopyroxene. The small compositional range and low phenocryst content indicate evolution controlled by low percentages (<10 %) of fractional crystallization of olivine and clinopyroxene of magmas similar to the least evolved rocks from the field, accompanied by assimilation during rapid ascent through the crust. Evolved andesites (˜62 wt% SiO2), on the other hand, are porphyritic rocks with plagioclase + orthopyroxene + biotite and ubiquitous phenocryst disequilibrium textures. These magmas were likely stored in crustal reservoirs, where they experienced convection caused by mafic magma underplating, magma mixing, and/or assimilation. Trace element and mineral compositions of CBAF lavas provide evidence for complex evolution of distinct magma batches.

  3. A preliminary interpretation of gas composition in the CP IV sector wells, Cerro Prieto geothermal field, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Arellano Gomez, Victor M; Portugal Marin, Enrique [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Perez Hernandez, Alfredo; Rodriguez Rodriguez, Marco Helio; Leon Vivar, Jesus de [Comision Federal de Electricidad, Residencia General Cerro Prieto, B.C. (Mexico)

    2007-07-15

    To increase the electrical generation capacity of the Cerro Prieto geothermal field from 620 MW to 720 MW, the Cerro Prieto IV (CP IV) sector of the field was developed in the NE portion of the exploited field. Fourteen new wells have been drilled there since 2000. The wells in CP IV zone produce two-phase fluids at wellhead with heterogeneous steam fraction characteristics: at the central zone and towards the NW, the wells are liquid-dominated while those towards the E and S produce a relatively high steam fraction. This work studies the gas compositions of produced fluids to obtain reservoir parameters such as temperature and steam fraction and identify different sources of fluids in the wells. A method was used based on the Fischer Tropsch reaction and H{sub 2}S equilibria with pyrite-pyrrhotite as a mineral buffer (FT-HSH3). The results for the natural state showed the presence of fluids with reservoir temperatures from 275 to 310 degrees Celsius and excess steam values from -1 to 50%. Data are aligned in a FT-HSH3 trend, suggesting that the well discharges consist of a mixture in different proportions of the two end members. One seems to be a liquid with a temperature of over 300 degrees Celsius with negative or negligible excess steam. The other seems to be a two-phase fluid with a temperature of about 275 degrees Celsius and an excess steam fraction of about 0.5. According to the data for single wells and depending on the production conditions of the wells, reservoir fluid mixtures could occur in different proportions of liquid and steam. Data for 2005 that included wells drilled after 2000 suggest the presence of a steam phase in the reservoir. The steam could be generated with the boiling of deep reservoir fluid from a pressure drop. The mixing trend obtained for the natural state was also seen for 2005 data but lower temperatures (from 265 to 295 degrees Celsius) were obtained compared with those for natural conditions. The entry of lower

  4. Dieta de murciélagos nectarívoros del Parque Nacional Cerros de Amotape, Tumbes

    Directory of Open Access Journals (Sweden)

    Edith Arias

    2011-07-01

    Full Text Available En el Perú se reporta la presencia de 18 especies de murciélagos nectarívoros, sin embargo se cuenta con poca información sobre la dieta de estas especies. En este estudio se reporta por primera vez la dieta de los nectarívoros Glossophaga soricina, Lonchophylla hesperia y Anoura geoffroyi en el bosque seco ecuatorial y del bosque tropical del Pacífico del Parque Nacional Cerros de Amotape, Tumbes. Analizamos 21 contenidos gastrointestinales e identificamos ocho morfotipos de polen pertenecientes a las familias Bombacaceae, Cactaceae, Fabaceae, Solanaceae, Rubiaceae, Myrtaceae, Malvaceae y Rosaceae. Encontramos evidencia del síndrome de quiropterofilia en Bombacaceae, Cactaceae, Fabaceae, Solanaceae y Rubiaceae. Observamos que A. geoffroyi consume polen de Ceiba trichistandra, Solanaceae y Rubiacea; G. soricina consume de Abutilon reflexum, Armathocereus cartwrightianus, C. trichistandra y Rubiaceae; y L. hesperia de A. cartwrightianus, Eriobotrya japonica, Fabaceae y Psidium sp.; sugiriendo una dieta generalista en estas especies. Los murciélagos G. soricina y A. geoffroyi comparten el consumo del ceibo C. trichistandra y de la Rubiaceae, mientras que G. soricina comparte con L. hesperia el consumo del cactus A. cartwrightianus. Los otros morfotipos de polen no fueron compartidos entre murciélagos. Se encuentra además que el ceibo C. trichistandra fue la especie más consumida, especialmente por G. soricina.

  5. Late Quaternary vegetation, fire and climate history reconstructed from two cores at Cerro Toledo, Podocarpus National Park, southeastern Ecuadorian Andes

    Science.gov (United States)

    Brunschön, Corinna; Behling, Hermann

    2009-11-01

    The last ca. 20,000 yr of palaeoenvironmental conditions in Podocarpus National Park in the southeastern Ecuadorian Andes have been reconstructed from two pollen records from Cerro Toledo (04°22'28.6"S, 79°06'41.5"W) at 3150 m and 3110 m elevation. Páramo vegetation with high proportions of Plantago rigida characterised the last glacial maximum (LGM), reflecting cold and wet conditions. The upper forest line was at markedly lower elevations than present. After ca. 16,200 cal yr BP, páramo vegetation decreased slightly while mountain rainforest developed, suggesting rising temperatures. The trend of increasing temperatures and mountain rainforest expansion continued until ca. 8500 cal yr BP, while highest temperatures probably occurred from 9300 to 8500 cal yr BP. From ca. 8500 cal yr BP, páramo vegetation re-expanded with dominance of Poaceae, suggesting a change to cooler conditions. During the late Holocene after ca. 1800 cal yr BP, a decrease in páramo indicates a change to warmer conditions. Anthropogenic impact near the study site is indicated for times after 2300 cal yr BP. The regional environmental history indicates that through time the eastern Andean Cordillera in South Ecuador was influenced by eastern Amazonian climates rather than western Pacific climates.

  6. Monitoring and modeling land subsidence at the Cerro Prieto Geothermal Field, Baja California, Mexico, using SAR interferometry

    Science.gov (United States)

    Carnec, Claudie; Fabriol, Hubert

    Images derived from repeat-pass spaceborne interferometric synthetic aperture radar (InSAR) systems offer the possibility of mapping surface deformation of small spatial extent and monitoring its spatio-temporal evolution. A slow local subsidence has been detected at the Cerro Prieto geothermal field from images acquired by the European Space Agency remote sensing satellites ERS-1/2 between 1993 and 1997. Although agricultural activity in the area limited the investigation, interferometric monitoring revealed that the ground deformation is associated with the withdrawal of geothermal fluid and agreed with the leveling data. Modeling of the subsidence was carried out assuming elastic deformation in a half-space from simple point sources, of which five were necessary to reproduce the fringe patterns observed on the interferograms. The depths and locations of three of the sources are compatible with the location of the known reservoir. The study improves prior knowledge of the displacement field and of the mecanisms involved in the subsidence phenomenon.

  7. El patrimonio industrial petrolero en la Patagonia: Comodoro Rivadavia (Argentina y Cerro Sombrero (Chile. Una perspectiva comparada

    Directory of Open Access Journals (Sweden)

    Pía Acevedo Méndez

    2016-01-01

    Full Text Available El hallazgo de petróleo en Comodoro Rivadavia (Chubut, Argentina y en Manantiales (Tierra del Fuego, lado chileno, motivó la construcción de espacios socioproductivos bajo el modelo de Company Towns. En el caso argentino la empresa estatal Yacimientos Petrolíferos Fiscales (Y.P.F creó el Campamento Central y la Empresa Nacional del Petróleo (ENAP creó Cerro Sombrero en Chile, los que en la década de 1970 formaron dos tejidos urbanos (barrio en el caso argentino y pueblo en el caso chileno. En esta dinámica se transformó el modo de habitar de ambos espacios, que se convirtieron en potenciales elementos turísticos, teniendo en cuenta que desde el año 2014 poseen reconocimiento patrimonial relacionado con su pasado petrolero y su arquitectura moderna. El objetivo es comparar cómo ambas empresas petroleras estatales construyeron dichos espacios “urbanos” y sus comunidades sociolaborales e indagar en la relación identidad/ patrimonio de ypefeanos y enapinos.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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...

  14. 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

  15. 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...

  16. 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.

  17. Los comportamientos reproductivos de la población mapuche de la provincia de Río Negro

    Directory of Open Access Journals (Sweden)

    Crognier, Emile

    1996-01-01

    Full Text Available Datos retrospectivos sobre la fecundidad de 200 mujeres de origen mapuche de la provincia de Río Negro (Argentina, son analizados con el fin de describir las características de su vida reproductiva. La pubertad relativamente precoz (en promedio la primera menstruación aparece a los 13 años, no es la señal de la entrada a la vida fecunda, ésta se produce en promedio 7 años más tarde. Luego, la natalidad es regular -intervalos de dos a tres años separan los nacimientos sucesivos- hasta su conclusión, que interviene en promedio alrededor de los 38 años, implicando que aún cerca de un 30% de las mujeres conciben después de 43 años. La lactancia materna se practica por un poco más de un año, lo que debe contribuir a aumentar la duración de los intervalos intergenésicos, a pesar de que por otro lado, el uso de contraceptivos parece regular. El ritmo de la vida reproductiva parece ser significativamente más rápido en la ciudad que en el campo e igualmente parece establecerse en esta dirección la evolución entre las generaciones.

  18. Perlas y piel de azabache. El negro en las pesquerías de las Indias Occidentales

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    Tardieu, Jean Pierre

    2008-12-01

    Full Text Available Not very long after the Discovery, the pearls from the West Indies competed with those from the Orient for the full regalia of the ladies of the gentry, or that of the most revered virgins, while raising the curiosity of the best known chroniclers and creating an excruciating tax system. Considering the legislation passed for the benefit of Indians, those were to a large extent replaced in the “pearl fisheries” by black slaves submitted by the covetousness of their masters and the interests of the Crown to horrendous living and working conditions which most of the time relentlessly led them to death.

    Poco después del Descubrimiento, las perlas de las Indias occidentales rivalizaron con las de Oriente para el adorno de las damas de la alta sociedad o de las Vírgenes más veneradas, suscitando la curiosidad científica de los cronistas más conocidos y una exigente legislación fiscal. Debido a las leyes emitidas a favor de los indios, éstos se sustituyeron en gran parte, en las pesquerías de perlas, por esclavos negros sometidos —por la codicia de los amos y el interés de la Corona— a despiadadas condiciones de vida y de trabajo que desembocaban las más veces en una muerte inexorable.

  19. Retórica del negro, blanco y rojo: razonabilidad y estética para persuadir con imagenes visuales

    Directory of Open Access Journals (Sweden)

    José Luiz Caivano

    2004-12-01

    Full Text Available Nuestra propuesta analizará cómo el uso del color puede ser un elemento privilegiado para argumentar en una imagen visual. Los valores y connotaciones atribuidos al color en el contexto de un enunciado visual funcionan como "pruebas" en razonamientos de tipo persuasivo. De este modo, el uso de figuras retóricas no es un fin en sí mismo sino el correlato visible de la argumentación que funciona como andamiaje oculto, implícito, de la persuasión. En esta oportunidad hemos elegido el rojo, el negro y el blanco por la frecuencia de su aparición, la cantidad de usos y lo nutrido de sus interpretaciones socioculturales - que incluso pueden resultar aparentemente paradójicas o contradictorias. Todos estos sentidos están latents y coexisten. Los colores son reinterpretados en correspondencia con los contextos de uso en los textos mismos (co-textos, y con los efectivos contextos sociales que los enmarcan en una situación real dada (espacio y tiempo históricos.

  20. Quem é negro, quem é branco: desempenho escolar e classificação racial de alunos

    Directory of Open Access Journals (Sweden)

    Marília Carvalho

    2005-01-01

    Full Text Available This article is based on research undertaken with classes from the 1st to 4th grades of primary education in a public school in the municipality of São Paulo and discusses the differences between the racial classification of school children carried out by teachers and that made by the children themselves. The concept of race adopted is that of “social race”, that is, a social construct based on an erroneous biological idea but which has proved efficient for maintaining privileges. Concludes that the fact that the difference in school performance between white and black children in the school is greater when the teachers’ classification is employed in place of self-classification results as much from teachers ‘whitening’ children with good performance as from their evaluating children, chiefly boys, they perceive as Negroes with greater rigour. It further emphasises that it is not a case of accusing the teachers of deliberate racial discrimination but of investigating the ways in which racism, present in Brazilian society as a whole, also penetrates school relations.