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Sample records for venezuela importancia como

  1. Venezuela.

    PubMed

    1987-04-01

    The background notes by the U.S. State Department on Venezuela emphasize the unique economic conditions in this oil-rich nation, and include information on its people, geography, history, government politics, defense and foreign relations. Venezuela, located on the north coast of South America, has 17,791,000 people, growing at a rate of 2.7%. Infant mortality is 2.7/1000, and life expectancy is 70 years. Geography ranges from the scarcely populated highlands between the Orinoco river and Guyana, the Orinoco plains, to the populated Andes mountains and coast. 80% of the population is urban. Literacy is a priority at 88.4%; Technical and university education is increasing; emigration from other countries is common because of relatively good working conditions. Venezuela has a long history of self government, having become independent in 1921. Now the democratic constitutional government is effective in improving both internal and regional development and human rights. The economy is based on oil production and refining, as well as steel and aluminum, all nationalized industries. Self-sufficiency in agriculture is a national goal. Because of the rapid population growth rate, however, per capita income and GNP are stagnating. PMID:12177927

  2. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

    article title:  Oil Slicks on Lake Maracaibo, Venezuela     View Larger Image ... oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various ...

  3. Venezuela`s gas industry poised for long term growth

    SciTech Connect

    Croft, G.D.

    1995-06-19

    Venezuela`s enormous gas resource, combined with a new willingness to invite outside investment, could result in rapid growth in that industry into the next century. The development of liquefied natural gas exports will depend on the future course of gas prices in the US and Europe, but reserves are adequate to supply additional projects beyond the proposed Cristobal Colon project. Venezuela`s gas reserves are likely to increase if exploration for nonassociated gas is undertaken on a larger scale. The paper discusses gas reserves in Venezuela, internal gas markets, the potential for exports, competition from Trinidad, LNG export markets, and the encouragement of foreign investment in the gas industry of Venezuela.

  4. Country watch: Venezuela.

    PubMed

    Koch, R

    1996-01-01

    Since 1990, ACCSI has worked to safeguard the rights of people living with HIV/AIDS in Venezuela. The Pan American Health Organization (PAHO) had recognized ACCSI's program by 1992, enabling the nongovernmental organization (NGO) to establish fixed office hours during which it can receive clients. ACCSI does not distinguish between people living with HIV/AIDS and others, but considers it important to regulate AIDS as a public health issue within the context of human rights and ethics. Almost all of the Legal Office's initial cases were related to discrimination in the workplace, health centers, and educational institutions, but the ACCSI now also addresses family problems related to adoption, insurance, and inheritance, among others. To cope with the increase in service caseload, services have been extended through collaboration with specialized organizations concerned with human rights, women, children, prisons, and indigenous people. ACCSI influences governmental policy-making through its participation in the National AIDS Program. Moreover, ACCSI's networking activities ensure that the topic of HIV/AIDS and human rights is now always included in seminars and conferences in Venezuela, even when they are concerned with sexually transmitted diseases or other medical issues. Almost every time the press report upon AIDS, they consult the NGO. Everyday more people in Venezuela are standing up for their rights and denouncing discrimination against people infected with HIV. PMID:12347178

  5. Enzootic transmission of yellow fever virus, Venezuela.

    PubMed

    Auguste, Albert J; Lemey, Philippe; Bergren, Nicholas A; Giambalvo, Dileyvic; Moncada, Maria; Morón, Dulce; Hernandez, Rosa; Navarro, Juan-Carlos; Weaver, Scott C

    2015-01-01

    Phylogenetic analysis of yellow fever virus (YFV) strains isolated from Venezuela strongly supports YFV maintenance in situ in Venezuela, with evidence of regionally independent evolution within the country. However, there is considerable YFV movement from Brazil to Venezuela and between Trinidad and Venezuela. PMID:25531105

  6. Enzootic Transmission of Yellow Fever Virus, Venezuela

    PubMed Central

    Auguste, Albert J.; Lemey, Philippe; Bergren, Nicholas A.; Giambalvo, Dileyvic; Moncada, Maria; Morón, Dulce; Hernandez, Rosa; Navarro, Juan-Carlos

    2015-01-01

    Phylogenetic analysis of yellow fever virus (YFV) strains isolated from Venezuela strongly supports YFV maintenance in situ in Venezuela, with evidence of regionally independent evolution within the country. However, there is considerable YFV movement from Brazil to Venezuela and between Trinidad and Venezuela. PMID:25531105

  7. Hctor L. Palacios Verdes Caracas, Venezuela

    E-print Network

    Palacios, Héctor

    Héctor L. Palacios Verdes Caracas, Venezuela Phone: ask Email: hectorpal@gmail.com Web page: http://www.ldc.usb.ve/~hlp Citizen: Venezuela Residence: Venezuela Education Ph. D. Informatics and Digital Communication December. Caracas, Venezuela. Thesis: Planning as Branch and Bound: a Constraint Programming implementation. Advisor

  8. THE PEARL FISHERY OF VENEZUELA

    E-print Network

    THE PEARL FISHERY OF VENEZUELA Marine Biological Lafi'ir-toiy X.I B K. A. R TT JUN 2 41950 WOODS Albert M. Day, Director Special Scientific Report - Fisheries Ho. 26 THE PEARL FISHERY OF VENEZUELA Paul S. Galtsoff Fishery Research Biologist COMTEHTS Page Introduction 2 Brief history of the pearl

  9. La enseñanza teatral en Venezuela

    E-print Network

    Rodrí guez, Orlando

    1988-04-01

    su transformación hacia 1981. Antes, en abril de 1977, al realizarse las Primeras Jornadas de Análisis de la Enseñanza Teatral en Venezuela, donde se reunió una veintena de institutos formadores de todo el país, se obtuvieron algu nas conclusiones... su transformación hacia 1981. Antes, en abril de 1977, al realizarse las Primeras Jornadas de Análisis de la Enseñanza Teatral en Venezuela, donde se reunió una veintena de institutos formadores de todo el país, se obtuvieron algu nas conclusiones...

  10. Universidad Central de Venezuela Facultad de Ciencias

    E-print Network

    Coto, Ernesto

    Universidad Central de Venezuela Facultad de Ciencias Escuela de Computación Una herramienta para. Universidad Central de Venezuela. {ecoto, hnavarro, omaira}@opalo.ciens.ucv.ve **Laboratorio TOOLS. Escuela de Computación. Facultad de Ciencias. Universidad Central de Venezuela. amatteo@isys.ciens.ucv.ve Caracas, Enero

  11. Universidad Central de Venezuela Facultad de Ciencias

    E-print Network

    Coto, Ernesto

    Universidad Central de Venezuela Facultad de Ciencias Escuela de Computación Lecturas en Ciencias Construcción de Algoritmos Ernesto Coto ecoto@strix.ciens.ucv.ve Universidad Central de Venezuela. Facultad de Ciencias. Escuela de Computación. Laboratorio de Computación Gráfica (LCG) Venezuela. Caracas Apdo. 47002

  12. Universidad Central de Venezuela Facultad de Ciencias

    E-print Network

    Coto, Ernesto

    Universidad Central de Venezuela Facultad de Ciencias Escuela de Computación Lecturas en Ciencias ecoto@strix.ciens.ucv.ve ecoto@opalo.ciens.ucv.ve Universidad Central de Venezuela. Facultad de Ciencias. Escuela de Computación. Laboratorio de Computación Gráfica (LCG) Venezuela. Caracas Apdo. 47002, 1041-A

  13. Universidad Central de Venezuela Facultad de Ciencias

    E-print Network

    Coto, Ernesto

    Universidad Central de Venezuela Facultad de Ciencias Escuela de Computación Lecturas en Ciencias@opalo.ciens.ucv.ve Universidad Central de Venezuela. Facultad de Ciencias. Escuela de Computación. Laboratorio de Computación Gráfica (LCG) Venezuela. Caracas Apdo. 47002, 1041-A. ND 2003-02 Resumen Los grafos son solo abstracciones

  14. Cephalopod Resources of Venezuela Introduction

    E-print Network

    in production of octopus (mainly Octopus maya). In Venezuela, both squid and octopus are produced as a by-catch of the shrimp fishery. Only Mexico has a directed fishery for octopus. In the past 10 years, squid and octo. Octopus, Octopus vulgaris, is abundant in the catches from June until October, with a peak in August

  15. Venezuela. America = Las Americas [Series].

    ERIC Educational Resources Information Center

    Toro, Leonor; Avery, Robert S.

    This bilingual English/Spanish social studies resource booklet provides an encyclopedia-style overview of Venezuela's history, geography, economy, and culture for teachers to use with migrant children in the elementary grades. Topics presented in the English portion include climate, land, people, customs, government, arts, food, culture, wildlife,…

  16. Family cluster of Mayaro fever, Venezuela.

    PubMed

    Torres, Jaime R; Russell, Kevin L; Vasquez, Clovis; Barrera, Roberto; Tesh, Robert B; Salas, Rosalba; Watts, Douglas M

    2004-07-01

    A cluster of protracted migratory polyarthritis involving four adult family members occurred in January 2000 after a brief overnight outing in a rural area of Venezuela. Laboratory testing demonstrated Mayaro virus as the cause of the cluster. These results documented the first human cases of Mayaro virus in Venezuela. PMID:15324555

  17. Family Cluster of Mayaro Fever, Venezuela

    PubMed Central

    Russell, Kevin L.; Vasquez, Clovis; Tesh, Robert B.; Salas, Rosalba; Watts, Douglas M.

    2004-01-01

    A cluster of protracted migratory polyarthritis involving four adult family members occurred in January 2000 after a brief overnight outing in a rural area of Venezuela. Laboratory testing demonstrated Mayaro virus as the cause of the cluster. These results documented the first human cases of Mayaro virus in Venezuela. PMID:15324555

  18. Hydrocarbon potential of Central Monagas, Eastern Venezuela Basin, Venezuela

    SciTech Connect

    Barrios, F.; Daza, J.; Iusco, G.

    1996-08-01

    The Central Monagas area is part of the foreland sub-basin located on the southern flank of the Eastern Venezuela Basin. The sedimentary column of the Central Monagas is at least 7500 in thick and consists of Mesozoic (Cretaceous) and Cenozoic rocks. Interpretations of 60 regional seismic sections have been integrated with data from 12 existing wells, which cover an area of 1200 km{sup 2}. From these interpretations, basin-wide structure and interval isopach maps were constructed in order to aid the depiction of the basin architecture and tectonic history. The sub-basin developed on the southern flank of the Eastern Venezuela Basin is tightly linked to its evolution from a Mesozoic extensional regime into a Cenozoic compressional and strike-slip stage. The basin formed in the Middle Mesozoic by crustal extension of a rifting process. Regional northward tilting of the slab continued during the Late Cretaceous. Finally, the transpression of the Caribbean Plate during the Oligocene-Neogene induced the overprint of compressional deformation associated with the deposition of a foredeep wedge. Geochemical source rock analysis gave an average of 1.2 TOC, and R{sub o} of 0.66 indicating a mature, marine source. The modeling of the hydrocarbon generative history of the basin indicates that the oil migration started in the Middle Miocene, after the trap was formed. Analysis and mapping of reservoir rocks and seal rocks defined the effective area limits of these critical factors. The main play in the area is the extension of the Lower Oficina Formation which is the proven petroleum target in the Eastern Venezuela Basin.

  19. An Example of Educational Transformation: Venezuela.

    ERIC Educational Resources Information Center

    Cirigliano, Gustavo F. J.

    1979-01-01

    Presents a case study of educational development in Venezuela, with emphasis on political and cultural influences, social needs, needs of developing nations, experimentation on all levels, fellowship programs, and projections for the future. (DB)

  20. Como Lo Hago Yo: Myelomeningocele

    PubMed Central

    Lazareff, Jorge

    2014-01-01

    Fortificación con ádico fólico es efectiva, pero aún falta conciencia en los jóvenes. La legalidad del aborto aumenta la importancia de la consulta prenatal. Realizo la cirugía bajo microcoscopio por razones didácticas. Irrigación continua para reducir la temperatura del tejido. Trato a la plaqueta como tejido viable. No suturo la plaqueta. No cierro músculo. ATB por una semana después de cirugía. Hidrocefalia: Válvula en todos los casos de ventriculomegalia. Médula anclada: Desanclar una sola vez. Chiari II: Revisar la válvula. Incluir en el seguimiento rendimiento escolar, puede indicar obstrucción de la válvula o médula anclada. PMID:24791217

  1. Festival Report: Experimental Theatre in Venezuela

    E-print Network

    1985-10-01

    THEATRE REVIEW Experimental Theatre in Venezuela The I Jornadas de Búsqueda y Experimentación Teatral took place March 21-May 19, 1985 in Caracas. Organized by the Centro Latinoamericano de Creación e Investigación Teatral (CELCIT) in collaboration... for experimental theatre groups to present their work and thus to show the current tendencies of unconventional theatre in Venezuela. The participating groups (among them Shock Teatral, Contradanza, Taller Experimental, Taller Actoral, Corso Teatro, La Misere...

  2. Reformulated gasoline deal with Venezuela draws heat

    SciTech Connect

    Begley, R.

    1994-04-06

    A fight is brewing in Congress over a deal to let Venezuela off the hook in complying with the Clean Air Act reformulated gasoline rule. When Venezuela threatened to call for a GATT panel to challenge the rule as a trade barrier, the Clinton Administration negotiated to alter the rule, a deal that members of Congress are characterizing as {open_quotes}secret{close_quotes} and {open_quotes}back door.{close_quotes}

  3. An Energy Overview of Venezuela

    SciTech Connect

    anon.

    2003-10-20

    The DOE Office of Fossil Energy is maintaining a web site that is meant to provide useful business- and energy-related information about countries and regions of the world for exporters, project developers, and researchers. The site consists of more than 130 country pages (organized into seven different world regions), with each country page having its own set of links to information sources about that country. There are also more than 30 Country Energy Overviews at the web site -- each of these is a comprehensive review of a specific country's entire energy situation, including sections on Energy Policy, Oil, Natural Gas, Coal, Hydroelectric/Renewables, Nuclear Power, Energy Transmission Infrastructure, Electricity, Electric Industry Overview, Environmental Activities, Privatization, Trade, and Economic Situation. The specific country highlighted in this Country Energy Overview is Venezuela. The site is designed to be dynamic. Updates to the overviews will be made as need and resources permit.

  4. Massive Variability Surveys from Venezuela

    E-print Network

    Cesar Briceno

    2003-04-03

    At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

  5. LA ASAMBLEA NACIONAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA

    E-print Network

    Vásquez, Carlos

    LA ASAMBLEA NACIONAL DE LA REP�BLICA BOLIVARIANA DE VENEZUELA DECRETA la siguiente, LEY ORGÁNICA DE organizativas y de funcionamiento del Sistema Educativo de la República Bolivariana de Venezuela. Ámbito de

  6. 78 FR 55096 - Ferrosilicon from Russia and Venezuela

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ...731-TA-1224-1225 (Preliminary)] Ferrosilicon from Russia and Venezuela Determination On the basis...materially injured by reason of imports from Russia and Venezuela of ferrosilicon, provided...reason of LTFV imports of ferrosilicon from Russia and Venezuela. Accordingly,...

  7. Repblica Bolivariana de Venezuela Consejo Nacional de Universidades

    E-print Network

    Vásquez, Carlos

    1 República Bolivariana de Venezuela Consejo Nacional de Universidades Núcleo de Vice requerida para una función determinada. #12;2 República Bolivariana de Venezuela Consejo Nacional de mundo tecnologizado y globalizado que habitamos. " #12;3 República Bolivariana de Venezuela Consejo

  8. Four New Hypancistrus (Siluriformes: Loricariidae) from Amazonas, Venezuela

    E-print Network

    Armbruster, Jonathan W.

    Four New Hypancistrus (Siluriformes: Loricariidae) from Amazonas, Venezuela JONATHAN W. ARMBRUSTER. lunaorum are described based on specimens from the upper Ri´o Orinoco of southern Venezuela. Hypancistrus la base de especi´menes provenientes de la cuenca alta del ri´o Orinoco en el sur de Venezuela

  9. Sir --Venezuela has entered 2003 deadlocked in a dangerous political

    E-print Network

    Chapman, Clark R.

    Sir -- Venezuela has entered 2003 deadlocked in a dangerous political confrontation and a general to preserve Venezuela's science and its natural environment, which is rich in biodiversity. We ask for Scientific Research, PO Box 21827, Caracas 1020A, Venezuela correspondence NATURE |VOL 421 |30 JANUARY 2003

  10. Mapa Geologico de Venezuela a Escala 1:750,000

    USGS Publications Warehouse

    Hackley, Paul C.; Urbani, Franco; Karlsen, Alex W.; Garrity, Christopher P.

    2006-01-01

    Se presenta un mapa geologico digital de Venezuela sobre un fondo de relieve sombreado. Los datos geologicos e hidrologicos del norte del rio Orinoco proceden de la digitalizacion de mapas geologicos en papel a escala 1:500.000. Estos datos fueron integrados con el mapa geologico digital del Escudo de Guayana Venezolano, a su vez derivado de hojas en papel a escala 1:500.000. La informacion sobre los tipos de fallas mostrados en el mapa es igual que en las fuentes originales. Los poligonos geologicos fueron atribuidos por edad, litologia y nombre de la unidad siguiendo el Codigo geologico de Venezuela. Se incorporaron revisiones significativas de la geologia de la Cordillera de la Costa a partir de las nuevas hojas integradas a escala 1:25.000. Toda esta informacion geologico-estructural se sobrepuso a una imagen de relieve sombreado, producida por el procesamiento de los datos de radar interferometrico con 90 m (3 arcosegundos) de resolucion espacial obtenidos por la mision topografica de radar del transbordador espacial (SRTM). Las areas de la base de datos del SRTM carentes de informacion fueron llenadas por medio de la interpolacion de los datos de las celdas adyacentes. Para producir la imagen de relieve sombreado se uso una direccion de iluminacion de 315 deg con un angulo de 65 deg sobre el horizonte. La proyeccion usada en el mapa es conica equidistante, con latitudes de 4 y 9 deg norte como paralelos estandar y una longitud de 66 deg al oeste como meridiano central. Los datos en el mapa proceden primordialment de hojas a escala 1:500.000 y el producto esta preparado para una impresion optima en escala 1:750.000. Los usuarios pueden obtener ampliaciones mayores, sin embargo no se garantiza la precision del mapa a escalas mas detalladas. Especialmente en la region de Guayana, al sobreponer los mapas geologicos sobre la reciente imagen SRTM, se notan grandes discrepancias no sistematicas tanto en contactos como en fallas. Esto es debido a que los mapas geologicos de Guayana tienen como base topografica las imagenes de radar de vision lateral (SLAR), con muy control de campo de los a?os 1970's. La correccion de estos desfases esta planificada para el futuro.

  11. Mastery: A Lesson from Maria in Venezuela

    ERIC Educational Resources Information Center

    Powell, Sandra Anez; Powell, Norman W.

    2012-01-01

    Children who have been born into poverty or into at-risk circumstances are often considered "disposable" and not a societal priority. These youngsters have few advocates and limited successful options in life. In the city of Maracaibo, Venezuela, there is a large population of Amerindians who are called Guajiros. These indigenous people have…

  12. Venezuela natural gas for vehicles project

    SciTech Connect

    Marsicobetre, D.; Molero, T.

    1998-12-31

    The Natural Gas for Vehicles (NGV) Project in Venezuela describes the development and growth of the NGV project in the country. Venezuela is a prolific oil producer with advanced exploration, production, refining and solid marketing infrastructure. Gas production is 5.2 Bscfd. The Venezuelan Government and the oil state owned company Petroleos de Venezuela (PDVSA), pursued the opportunity of using natural gas for vehicles based on the huge amounts of gas reserves present and produced every day associated with the oil production. A nationwide gas pipeline network crosses the country from south to west reaching the most important cities and serving domestic and industrial purposes but there are no facilities to process or export liquefied natural gas. NGV has been introduced gradually in Venezuela over the last eight years by PDVSA. One hundred forty-five NGV stations have been installed and another 25 are under construction. Work done comprises displacement or relocation of existing gasoline equipment, civil work, installation and commissioning of equipment. The acceptance and usage of the NGV system is reflected in the more than 17,000 vehicles that have been converted to date using the equivalent of 2,000 bbl oil/day.

  13. The history of aeronautical medicine in Venezuela

    NASA Technical Reports Server (NTRS)

    Iriarte, D. R.

    1986-01-01

    The Aerial Medical Service of the Ministry of Transportation and Communications of Venezuela was created on June 1949, and later became the Department of Aeronautical Medicine. Its functions include the medical examinations of future pilots, navigators and flight engineers. The importance of good mental and physical health in all flight and ground personnel to ensure the safety of air travel is discussed.

  14. 78 FR 49471 - Ferrosilicon From the Russian Federation and Venezuela: Initiation of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ...ferrosilicon from the Russian Federation (``Russia'') and Venezuela filed in proper form...company-specific questions (``Supplement to Russia Petition'' and ``Supplement to Venezuela...Antidumping Duties on Ferrosilicon from Russia and Venezuela,'' filed on July...

  15. 78 FR 9034 - Silicomanganese From India, Kazakhstan, and Venezuela: Final Results of the Expedited Second...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-07

    ...A-307-820] Silicomanganese From India, Kazakhstan, and Venezuela: Final Results...antidumping duty orders on silicomanganese from India, Kazakhstan, and Venezuela. The Department...antidumping duty orders on silicomanganese from India, Kazakhstan, and Venezuela were...

  16. 78 FR 60846 - Silicomanganese From India, Kazakhstan, and Venezuela: Continuation of Antidumping Duty Orders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ...A-307-820] Silicomanganese From India, Kazakhstan, and Venezuela: Continuation...antidumping duty orders on silicomanganese from India, Kazakhstan, and Venezuela would likely...antidumping duty orders on silicomanganese from India, Kazakhstan, and Venezuela,...

  17. REPBLICA BOLIVARIANA DE VENEZUELA Consejo Nacional de Universidades

    E-print Network

    Vásquez, Carlos

    REP�BLICA BOLIVARIANA DE VENEZUELA Consejo Nacional de Universidades Núcleo de Autoridades de Instituciones de Educación Universitaria de Venezuela (NAEX), reunido en sesión Ordinaria en la sede de la Dirección de Extensión de la Universidad Central de Venezuela en la ciudad de Caracas el día 15 de mayo de

  18. Astrometry and Geostationary Satellites in Venezuela

    NASA Astrophysics Data System (ADS)

    Lacruz, E.; Abad, C.

    2015-10-01

    We present the current status and the first results of the astrometric project CIDA - ABAE for tracking geo-stationary satellites. This project aims to determine a preliminary orbit for the Venezuelan satellite VENESAT-1, using astrometric positions obtained from an optical telescope. The results presented here are based on observations from the Luepa space tracking ground station in Venezuela, which were processed using astrometric procedures.

  19. Wing shape divergence between Rhodnius prolixus from Cojedes (Venezuela) and Rhodnius robustus from Mérida (Venezuela).

    PubMed

    Villegas, J; Feliciangeli, M D; Dujardin, J P

    2002-12-01

    The existence of Rhodnius robustus as a species distinct from Rhodnius prolixus has long been the main epidemiological question about Chagas disease transmission in Venezuela and surrounding countries. These two taxa are morphologically and genetically very similar, but only R. prolixus is assumed to colonize houses and transmit Chagas disease to humans. R. robustus is assumed to be an exclusively sylvatic species, restricted to palm trees. If robustus and prolixus are actually the same species, the theoretical possibility exists of sylvatic specimens invading houses, even after insecticide application, and a control strategy similar to that of the successful Southern Cone Initiative against Triatoma infestans would be difficult to consider. Since no valid alternative control strategy exists, the answer to this biological question could be decisive about the future of vector control in this region. Although we believe genetic techniques are best suited to define species boundaries, we present here an example of the relevance of modern morphometrics in dealing with such an issue. Using both traditional and geometric morphometrics, we compared the wing size and shape in both sexes of these two taxa reared in the same laboratory for one generation. R. robustus specimens were collected from palm trees in the state of Mérida (Venezuela), and R. prolixus were collected from houses in the state of Cojedes (Venezuela). Our study provided no argument to question their specific status. Even after one generation of living in the same laboratory conditions, the two lines showed clear size differences, divergent allometric trends, and significant allometry-free differences in shape. These results suggest that R. robustus (Mérida, Venezuela) and R. prolixus (Cojedes, Venezuela) are distinct evolutionary units. Due to the epidemiological importance of this question, further studies in other geographic areas of Venezuela are required to accurately define the relationships of R. robustus and R. prolixus. PMID:12797988

  20. The Dairy Technology System in Venezuela. Summary of Research 79.

    ERIC Educational Resources Information Center

    Nieto, Ruben D.; Henderson, Janet L.

    A study examined the agricultural technology system in Venezuela with emphasis on the dairy industry. An analytical framework was used to identify the strengths and weaknesses of the following components of Venezuela's agricultural technology system: policy, technology development, technology transfer, and technology use. Selected government…

  1. Using the Five Themes of Geography to Teach about Venezuela.

    ERIC Educational Resources Information Center

    Sunal, Cynthia Szymanski; And Others

    1995-01-01

    Maintains that Venezuela has many U.S. ties because of its relative proximity and economic significance. Asserts that the Five Themes of Geography can be used to design effective classroom lessons about Venezuela. Presents five activities that include student objectives, necessary materials, and step-by-step instructional procedures. (CFR)

  2. 78 FR 55096 - Ferrosilicon from Russia and Venezuela

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... publishing the notice in the Federal Register of July 25, 2013 (78 FR 44969). The conference was held in... COMMISSION Ferrosilicon from Russia and Venezuela Determination On the basis of the record \\1\\ developed in... Russia and Venezuela of ferrosilicon, provided for in subheadings 7202.21.10, 7202.21.50,...

  3. Critical Pedagogy and Empowering in Teacher Education in Venezuela.

    ERIC Educational Resources Information Center

    Chacon, Carmen T.; Alvarez, Luisa Cristina

    This paper addresses the issue of the relationship between critical pedagogy and English as a foreign language (EFL) in Venezuela. Teacher-researchers have come to see the issues confronting nonnative educators in ELT as a more important issue than in previous years. They are particularly concerned about the current situation in Venezuela

  4. e-Science perspectives in Venezuela

    E-print Network

    Díaz, G; Hamar, V; Hoeger, H; Mendoza, C; Mendez, Z; Núñez, L A; Ruiz, N; Torrens, R; Uzcategui, M

    2008-01-01

    We describe the e-Science strategy in Venezuela, in particular initiatives by the Centro Nacional de Calculo Cientifico Universidad de Los Andes (CECALCULA), Merida, the Universidad de Los Andes (ULA), Merida, and the Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas. We present the plans for the Venezuelan Academic Grid and the current status of Grid ULA supported by Internet2. We show different web-based scientific applications that are being developed in quantum chemistry, atomic physics, structural damage analysis, biomedicine and bioclimate within the framework of the E-Infrastructure shared between Europe and Latin America (EELA)

  5. 420?Lentil Allergy: First Report from Venezuela

    PubMed Central

    Albarran, Carlos; Hulett, Arnaldo Capriles

    2012-01-01

    Background Allergy to lentils is infrequent in Latin America: this a first case report from Venezuela. A 5 year old female preschooler attended our allergology clinic with chief complaint of generalized giant urticaria inmediately after ingestion of cooked lentils; clinical history revealed frequent (>3) emergency visits, since the age of one year, with facial angioedema and generalized urticaria even from inhalation of vapors while cooking of lentils at home; moreover, also symptoms described ocurred while eating foods containing chick peas; lentils, as other beans (black, red, chick), belong to the leguminosa family along with peanuts and coconut. Methods Prick lancetter skin tests (H-S) to a panel of 25 inhalant and food allergens (Diater Labs, Argentina) were performed along with Prick to Prick tests to raw and cooked lentils, chickpeas, black beans, navy beans and coconut. A papule >3 mm and read at 10 minutes was considered positive. Results All other allergens tested were negative, that is, epithelia, molds, cockroach, grasses, mosquito, milk, egg, wheat, fishmix, shrimp and other seafood, nuts, hazelnut, almond, coconut and blackbeans. Conclusions 1. Prick to Prick testing confirms specific IgE presence to Lentils; our patient could tolerate peanuts and cocunut. Positive prick test to peanuts likely represent a cross reaction1; 2. Lupin flour (Lupinus Albus), from the Leguminosa family, is found increasingly used in industrially prepared foods and could elicit symptoms due to cross reactions, and advice to family was given accordingly2; 3. This is the first case report from Venezuela.

  6. A reservoir management strategy for multilayered reservoirs in eastern Venezuela 

    E-print Network

    Espinel Diaz, Arnaldo Leopoldo

    1998-01-01

    A reservoir management strategy has been developed for a field located in eastern Venezuela. The field contains deep, high pressure, multilayer reservoirs. A thorough formation evaluation was accomplished using the log data, core data, PVT data...

  7. Tax effects upon oil field development in Venezuela

    E-print Network

    Manzano, Osmel

    2000-01-01

    Important reforms have been made to the oil sector tax code in Venezuela. Given its diversity of oil resources, there was a concern that some resources were not being exploited because of the structure of the tax code. ...

  8. New species and records of Hydroptilidae (Trichoptera) from Venezuela

    PubMed Central

    Thomson, Robin E.; Holzenthal, Ralph W.

    2012-01-01

    Abstract Eight new species of Hydroptilidae (Trichoptera) from Venezuela are described: Acostatrichia digitata sp. n., Hydroptila cressae sp. n., Metrichia botrychion sp. n., Ochrotrichia spira sp. n., Oxyethira bettyae sp. n., Oxyethira quiramae sp. n., Oxyethira redunca sp. n., and Rhyacopsyche shorti sp. n.New country records for Venezuela of 2 additional species, Neotrichia feolai Santos & Nessimian, 2009 and Oxyethira picita Harris & Davenport, 1999, are also provided. Illustrations of male genitalia are provided with each description. PMID:22577311

  9. Hydrogen: BOC-FW venture secures major Venezuela project

    SciTech Connect

    Wood, A.

    1995-07-26

    BOC Gases and Foster Wheeler Power Systems (FW) have been awarded a $50-million project to supply a 50-million cu ft/day hydrogen (H{sub 2}) plant to Lagoven`s Amuay, Venezuela refinery for 1997 startup. BOC and FW have also formed a marketing agreement for on-site H{sub 2} plants in the Americas, extending a previous relationship covering Chile and Venezuela.

  10. e-Science initiatives in Venezuela

    E-print Network

    Chaves, J L; Hamar, V; Isea, R; Rojas, F; Ruiz, N; Torrens, R; Uzcategui, M; Florez-Lopez, J; Hoeger, H; Mendoza, C; Núñez, L A

    2007-01-01

    Within the context of the nascent e-Science infrastructure in Venezuela, we describe several web-based scientific applications developed at the Centro Nacional de Calculo Cientifico Universidad de Los Andes (CeCalCULA), Merida, and at the Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas. The different strategies that have been followed for implementing quantum chemistry and atomic physics applications are presented. We also briefly discuss a damage portal based on dynamic, nonlinear, finite elements of lumped damage mechanics and a biomedical portal developed within the framework of the \\textit{E-Infrastructure shared between Europe and Latin America} (EELA) initiative for searching common sequences and inferring their functions in parasitic diseases such as leishmaniasis, chagas and malaria.

  11. Digital shaded-relief map of Venezuela

    USGS Publications Warehouse

    Garrity, Christopher P.; Hackley, Paul C.; Urbani, Franco

    2004-01-01

    The Digital Shaded-Relief Map of Venezuela is a composite of more than 20 tiles of 90 meter (3 arc second) pixel resolution elevation data, captured during the Shuttle Radar Topography Mission (SRTM) in February 2000. The SRTM, a joint project between the National Geospatial-Intelligence Agency (NGA) and the National Aeronautics and Space Administration (NASA), provides the most accurate and comprehensive international digital elevation dataset ever assembled. The 10-day flight mission aboard the U.S. Space Shuttle Endeavour obtained elevation data for about 80% of the world's landmass at 3-5 meter pixel resolution through the use of synthetic aperture radar (SAR) technology. SAR is desirable because it acquires data along continuous swaths, maintaining data consistency across large areas, independent of cloud cover. Swaths were captured at an altitude of 230 km, and are approximately 225 km wide with varying lengths. Rendering of the shaded-relief image required editing of the raw elevation data to remove numerous holes and anomalously high and low values inherent in the dataset. Customized ArcInfo Arc Macro Language (AML) scripts were written to interpolate areas of null values and generalize irregular elevation spikes and wells. Coastlines and major water bodies used as a clipping mask were extracted from 1:500,000-scale geologic maps of Venezuela (Bellizzia and others, 1976). The shaded-relief image was rendered with an illumination azimuth of 315? and an altitude of 65?. A vertical exaggeration of 2X was applied to the image to enhance land-surface features. Image post-processing techniques were accomplished using conventional desktop imaging software.

  12. 78 FR 44969 - Ferrosilicon From Russia and Venezuela; Institution of Antidumping Duty Investigations and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ...731-TA-1224-1225 (Preliminary)] Ferrosilicon From Russia and Venezuela; Institution of Antidumping Duty Investigations...United States is materially retarded, by reason of imports from Russia and Venezuela of Ferrosilicon, provided for in...

  13. GACETA OFICIAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA AO CXXVIII-MES VII

    E-print Network

    Vásquez, Carlos

    GACETA OFICIAL DE LA REP�BLICA BOLIVARIANA DE VENEZUELA A�O CXXVIII- MES VII Caracas: Viernes 27 de BOLIVARIANA DE VENEZUELA MINISTERIO DE EDUCACI�N, CULTURA Y DEPORTES DESPACHO DEL MINISTRO. RESOLUCI�N Nº 145

  14. David Meets Goliath on the Information Superhighway: Venezuela in the Context of the Electronic Communication Networks.

    ERIC Educational Resources Information Center

    Sanchez-Vegas, Saadia

    1995-01-01

    Discusses Venezuela's information and communications technology infrastructure and usage patterns; examines future networking plans; and addresses political and economic considerations linked to the information and technology problems in Venezuela and in Latin America in general. (LRW)

  15. Ecology of large piscivorous fishes in Guri Reservoir, Venezuela, with notes on fish community structure 

    E-print Network

    Williams, John David

    1995-01-01

    Venezuela's growing human population is accompanied by a growing need for electricity which has largely been met with hydroelectric power, and yet the full effects of river impoundment on river ecosystems are not known. Venezuela currently has...

  16. Mantle flow beneath northwestern Venezuela: Seismic evidence for a deep origin of the Mrida Andes

    E-print Network

    Niu, Fenglin

    Mantle flow beneath northwestern Venezuela: Seismic evidence for a deep origin of the Mérida Andes University, Houston, TX, USA b Fundación de Investigaciones Simológicas (FUNVISIS), Caracas, Venezuela a b wave splitting from SKS data recorded by the national seismic network of Venezuela and a linear

  17. TWO NEW SPECIES OF LEPIDOCYRTUS FROM PARAMO DE MUCUBAJI MERIDA, VENEZUELA

    E-print Network

    Mari-Mutt, José A.

    TWO NEW SPECIES OF LEPIDOCYRTUS FROM PARAMO DE MUCUBAJI MERIDA, VENEZUELA (COLLEMBOLA ejemplares colectados en Paramo de Mucubaji, Estado de Merida, Venezuela. Los individuos fueron encontrados in Venezuela but only one, L. summersii (MacGillivray) 1894, has been described or reported from this country

  18. POTENTIAL EFFECTS OF GLOBAL CLIMATIC CHANGE ON THE PHENOLOGY AND YIELD OF MAIZE IN VENEZUELA *

    E-print Network

    Robock, Alan

    POTENTIAL EFFECTS OF GLOBAL CLIMATIC CHANGE ON THE PHENOLOGY AND YIELD OF MAIZE IN VENEZUELA de Ciencias, Universidad de Los Andes, Mdrida 5101, Venezuela 21nstitute of Applied Sciences, Venezuela 4Centro de Estudios Avanzados del Clima Tropical (CEACT), Ministerio deI Ambiente y de los

  19. NATURAL HAZARDS ON ALLUVIAL FANS: THE VENEZUELA DEBRIS FLOW AND FLASH FLOOD DISASTER

    E-print Network

    Eaton, L. Scott

    NATURAL HAZARDS ON ALLUVIAL FANS: THE VENEZUELA DEBRIS FLOW AND FLASH FLOOD DISASTER In December Venezuela. Rainfall on December 2-3 totaled 200 millimeters (8 inches) and was followed by a major storm, Denver, Colorado, Naples, Italy, and Vargas, Venezuela. In time scales spanning thousands of years

  20. BREEDING BIOLOGY AND NATURAL HISTORY OF THE SLATE-THROATED WHITESTART IN VENEZUELA

    E-print Network

    Martin, Thomas E.

    BREEDING BIOLOGY AND NATURAL HISTORY OF THE SLATE-THROATED WHITESTART IN VENEZUELA ROMA´ N A´ National Park, Venezuela. Nesting activity peaked in late April and May. Only the female built the nest is the most common race in the Andes of Venezuela, Colombia, and part of Ecuador. Genetic information for our

  1. Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1

    E-print Network

    Sigman, Daniel M.

    Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1 Daniel M. Sigman,2 of Venezuela. Water column denitrification occurring in the basin has only a very small isotopic imprint-Karger, Y. Astor, and R. Varela (2004), Nitrogen isotope dynamics of the Cariaco Basin, Venezuela, Global

  2. An Interview with Margot Benacerraf: Reveron, Araya, and the Institutionalization of Cinema in Venezuela.

    ERIC Educational Resources Information Center

    Schwartzman, Karen

    1993-01-01

    Presents an interview (edited into a first-person form) with Margot Benacerraf, known for two prize-winning films in the 1950s but not as well known for her active promotion of film culture in Venezuela. Discusses her education in Venezuela, travels outside Venezuela, production of her prize-winning films, and her efforts at promoting the…

  3. STATUS ACTUAL DE LOS REFRACTARIOS EN VENEZUELA: MATRIZ F-O-D-A Y PERSPECTIVAS FUTURAS

    E-print Network

    Vásquez, Carlos

    STATUS ACTUAL DE LOS REFRACTARIOS EN VENEZUELA: MATRIZ F-O-D-A Y PERSPECTIVAS FUTURAS Delia, Dept. de Ciencia de los Materiales, Caracas, Venezuela * dgutierr@usb.ve RESUMEN La industria manufacturera de materiales refractarios en Venezuela tiene más de 50 años. Entre las décadas del 60 y del 90

  4. Receiver function study of the crustal structure of the southeastern Caribbean plate boundary and Venezuela

    E-print Network

    Niu, Fenglin

    and Venezuela Fenglin Niu,1 Tammy Bravo,2 Gary Pavlis,2 Frank Vernon,3 Herbert Rendon,4 Maximiliano Bezada,1 broadband array deployed under the BOLIVAR project and the permanent national seismic network of Venezuela northeastern Venezuela and the Venezuelan Andes. There is a good correlation between crustal structure

  5. Pathogenicity of seven species of the Botryosphaeriaceae on Eucalyptus clones in Venezuela

    E-print Network

    Pathogenicity of seven species of the Botryosphaeriaceae on Eucalyptus clones in Venezuela S. R Milla, 5101-A Mérida, Venezuela. B Department of Genetics, Forestry and Agricultural Biotechnology found on Eucalyptus spp. in Venezuela. An initial inoculation trial was conducted using seven species

  6. Ingeniero Diana Awais GACETA OFICIAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA

    E-print Network

    Vásquez, Carlos

    Ingeniero Diana Awais GACETA OFICIAL DE LA REP�BLICA BOLIVARIANA DE VENEZUELA A�O CXXX-MES IX Funcional, que en ella se especifican. REP�BLICA BOLIVARIANA DE VENEZUELA CONSEJO NACIONAL DE UNIVERSIDADES de la República Bolivariana de Venezuela, introduce innovaciones en el campo jurídico

  7. BREEDING BIOLOGY OF THE GOLDEN-FACED TYRANNULET (ZIMMERIUS CHRYSOPS) IN VENEZUELA

    E-print Network

    Martin, Thomas E.

    BREEDING BIOLOGY OF THE GOLDEN-FACED TYRANNULET (ZIMMERIUS CHRYSOPS) IN VENEZUELA WILLIAM GOULDING1 Park, Venezuela during the 2002 to 2008 breeding seasons. The enclosed nest was similar to descriptions, it is broadly distributed with a range that extends from Peru, north through the Andes to Colombia and Venezuela

  8. Estudio muestra importancia de conversaciones tempranas sobre el cuidado en etapa final de la vida

    Cancer.gov

    Artículo sobre la importancia de hablar en forma temprana sobre el cuidado paliativo para asegurar que la atención prestada en la etapa final de la vida sea más acorde con las preferencias de los pacientes.

  9. Malaria control and elimination, Venezuela, 1800s –1970s.

    PubMed

    Griffing, Sean M; Villegas, Leopoldo; Udhayakumar, Venkatachalam

    2014-10-01

    Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920,malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world's interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication.Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization.We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines. PMID:25396258

  10. Malaria Control and Elimination,1 Venezuela, 1800s–1970s

    PubMed Central

    Villegas, Leopoldo; Udhayakumar, Venkatachalam

    2014-01-01

    Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920, malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world’s interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication. Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization. We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines.

  11. Digital geologic map and GIS database of Venezuela

    USGS Publications Warehouse

    Garrity, Christopher P.; Hackley, Paul C.; Urbani, Franco

    2006-01-01

    The digital geologic map and GIS database of Venezuela captures GIS compatible geologic and hydrologic data from the 'Geologic Shaded Relief Map of Venezuela,' which was released online as U.S. Geological Survey Open-File Report 2005-1038. Digital datasets and corresponding metadata files are stored in ESRI geodatabase format; accessible via ArcGIS 9.X. Feature classes in the geodatabase include geologic unit polygons, open water polygons, coincident geologic unit linework (contacts, faults, etc.) and non-coincident geologic unit linework (folds, drainage networks, etc.). Geologic unit polygon data were attributed for age, name, and lithologic type following the Lexico Estratigrafico de Venezuela. All digital datasets were captured from source data at 1:750,000. Although users may view and analyze data at varying scales, the authors make no guarantee as to the accuracy of the data at scales larger than 1:750,000.

  12. Syllidae (Annelida, Polychaeta) from the Caribbean coast of Venezuela

    PubMed Central

    Liñero-Arana, Ildefonso; Díaz Díaz, Oscarn

    2011-01-01

    Abstract Venezuela possesses a great variety of coastal environments allowing for a high diversity of marine species. However, systematic studies on marine invertebrates are scarce, especially on polychaetes. The family Syllidae is poorly known, and only 14 genera and 42 species have been reported from this country. A total of 13 genera and 26 species the Syllidae were identified from benthic samples collected on different substrata of the northeastern coast of Venezuela. Of these, seven genera and 16 species constitute new records for Venezuela: Odontosyllis guillermoi, Syllides floridanus, Salvatoria clavata, Salvatoria limbata, Sphaerosyllis longicauda, Parapionosyllis longicirrata, Trypanosyllis parvidentata, Trypanosyllis vittigera, Opisthosyllis sp., Syllis amica, Syllis armillaris, Syllis gracilis, Syllis pseudoarmillaris, Syllis vittata, Parasphaerosyllis indica and Myrianida convoluta. PMID:21998503

  13. Current Space Projects of the Bolivarian Republic of Venezuela

    NASA Astrophysics Data System (ADS)

    Hernández, R.; Acevedo R.; Varela, F.; Otero, S.

    2014-06-01

    Since 2008, with the successful launch of the first Venezuelan telecommunication satellite VENESAT-1, the Bolivarian Republic of Venezuela became an active player in the international space sector aimed at using space science and technology as a powerful tool to promote the national development. Based on that, through the Bolivarian Agency for Space Activities (ABAE), Venezuela has been implemented several space projects such as the manufacturing and launch of the first Venezuelan remote sensing satellite, the construction of a design center for small satellite technologies, as well as research and development activities related with the estimation of the physical properties of the Earth. This paper presents a brief description of the current space projects that are being developed by Venezuela.

  14. Political Bots and the Manipulation of Public Opinion in Venezuela

    E-print Network

    Forelle, Michelle; Monroy-Hernández, Andrés; Savage, Saiph

    2015-01-01

    Social and political bots have a small but strategic role in Venezuelan political conversations. These automated scripts generate content through social media platforms and then interact with people. In this preliminary study on the use of political bots in Venezuela, we analyze the tweeting, following and retweeting patterns for the accounts of prominent Venezuelan politicians and prominent Venezuelan bots. We find that bots generate a very small proportion of all the traffic about political life in Venezuela. Bots are used to retweet content from Venezuelan politicians but the effect is subtle in that less than 10 percent of all retweets come from bot-related platforms. Nonetheless, we find that the most active bots are those used by Venezuela's radical opposition. Bots are pretending to be political leaders, government agencies and political parties more than citizens. Finally, bots are promoting innocuous political events more than attacking opponents or spreading misinformation.

  15. Complete genome sequences of two begomoviruses infecting weeds in Venezuela.

    PubMed

    Fiallo-Olivé, Elvira; Chirinos, Dorys T; Geraud-Pouey, Francis; Moriones, Enrique; Navas-Castillo, Jesús

    2013-01-01

    The complete sequences of isolates of two new bipartite begomoviruses (genus Begomovirus, family Geminiviridae) found infecting weeds in Venezuela are provided. The names proposed for these new begomoviruses are "Datura leaf distortion virus" (DLDV), isolated from a Datura stramonium L. (family Solanaceae) plant, and "Dalechampia chlorotic mosaic virus" (DCMV), isolated from infected Dalechampia sp. (family Euphorbiaceae) and Boerhavia diffusa L. (family Nyctaginaceae) plants. Phylogenetic analysis showed that these new begomoviruses segregated in two distinct clades of New World begomoviruses. To our knowledge, this is the first record of a begomovirus infecting Dalechampia sp. plants. Also, this is the first report of a begomovirus infecting Boerhavia spp. and Datura spp. in Venezuela. PMID:22926716

  16. A new species of Corydalus Latreille from Venezuela (Megaloptera, Corydalidae)

    PubMed Central

    Contreras-Ramos, Atilano; von der Dunk, Klaus

    2010-01-01

    Abstract A new species of dobsonfly, Corydalus wanningeri, from Venezuela, is described and illustrated. It superficially resembles Corydalus neblinensis Contreras-Ramos, with a uniform reddish coloration of body and wings. Yet, because of male genitalic structure it might be closely related to Corydalus crossi Contreras-Ramos. Specimens were collected from a rain forest transitional zone between the Orinoco lowlands and the Gran Sabana plateau, in Bolívar state. This is the 15th species of Corydalus to be recorded from Venezuela, rendering this the country with the highest number of documented Corydalus species. A key to the sexually dimorphic, long-mandibled Venezuelan species of the genus is provided. PMID:21594032

  17. Events affecting gold exploration in Venezuela since 1999

    USGS Publications Warehouse

    Wilburn, David R.

    2014-01-01

    The structure of the gold mining industry in Venezuela has changed significantly since 1999 as a result of Government policy changes and industry response to these changes. This report documents the policy decisions that have affected the mining industry, discusses the response of the industry on a site by site basis, and suggests possible effects of these changes on the global economy. For the short term, at least, it appears that these changes have made Venezuela a more difficult place to invest for U.S. and Canadian companies, while investment by Chinese entities has been encouraged.

  18. The Bocono Fault Zone, Western Venezuela

    SciTech Connect

    Schubert, C. ); Estevez, R. ); Henneberg, H.G. )

    1993-02-01

    The Bocono Fault Zone, the western part of the Bocono Moron-El Pilar Fault System of the southern Caribbean plate boundary, consists of aligned valleys, linear depressions, pull-apart basins and other morphological features, which extend for about 500 km in a N45[degrees]E direction, between the Tachira depression (Venezuela-Colombia border) and the Caribbean Sea. It crosses obliquely the Cordillera de Merida and cuts across the Caribbean Mountains, two different geologic provinces of Late Tertiary-Quaternary and Late Cretaceous-Early Tertiary age, respectively. Therefore, the maximum age that can be assigned to the Bocono Fault Zone is Late Tertiary (probably Pliocene). A total maximum right-lateral offset rate of 3.3 mm/a. The age of the sedimentary fill o[approximately] the La Gonzalez pull-apart basin suggests that the 7-9 km right-lateral offset necessary to produce it took place in Middle to Late Pleistocene time. The majority of seismic events are well aligned with the main fault trace; minor events are distributed in a belt several kilometers wide. Focal depth is typically 15 km and focal mechanisms indicate an average east-west compression across the zone. Return periods of 135-460 a (Richter M = 8), 45-70 a (M = 7), and 7-15 a (M = 6) have been calculated. Geodetic studies of several sites along the zone indicate compressive and right-lateral components; at Mucubaji the rate of right-lateral displacement observed is about 1 mm every 5 months (15 a of measurements).

  19. TUBERCULOSIS COMO ENFERMEDAD OCUPACIONAL

    PubMed Central

    Mendoza-Ticona, Alberto

    2014-01-01

    Existe evidencia suficiente para declarar a la tuberculosis como enfermedad ocupacional en diversos profesionales especialmente entre los trabajadores de salud. En el Perú están normados y reglamentados los derechos laborales inherentes a la tuberculosis como enfermedad ocupacional, como la cobertura por discapacidad temporal o permanente. Sin embargo, estos derechos aún no han sido suficientemente socializados. En este trabajo se presenta información sobre el riesgo de adquirir tuberculosis en el lugar de trabajo, se revisan las evidencias para declarar a la tuberculosis como enfermedad ocupacional en trabajadores de salud y se presenta la legislación peruana vigente al respecto. PMID:22858771

  20. Molecular Epidemiologic Source Tracking of Orally Transmitted Chagas Disease, Venezuela

    PubMed Central

    Segovia, Maikell; Martínez, Clara E.; Messenger, Louisa A.; Nessi, Anaibeth; Londoño, Juan C.; Espinosa, Raul; Martínez, Cinda; Alfredo, Mijares; Bonfante-Cabarcas, Rafael; Lewis, Michael D.; de Noya, Belkisyolé A.; Miles, Michael A.; Llewellyn, Martin S.

    2013-01-01

    Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing. PMID:23768982

  1. A contribution to the centipede fauna of Venezuela (Chilopoda: Scolopendromorpha).

    PubMed

    Schileyko, Arkady A

    2014-01-01

    The descriptions of twelve Venezuelan Scolopendromorpha, a list of species, identification key and detailed list of localities are presented. Cryptops (C.) venezuelae Chamberlin, 1939, known only from the holotype has been re-described and Scolopendra conjungens Muralewicz, 1913 reduced to a junior synonym of Scolopendra angulata Newport, 1844 syn. nov. PMID:24989735

  2. Late Pleistocene carbonate dissolution in the Venezuela Basin, Caribbean Sea

    SciTech Connect

    Cofer-Shabica, N.B.; Peterson, L.C.

    1985-01-01

    Piston cores from water depths greater than 4000 m in the Venezuela Basin (Caribbean Sea) provide continuous late Pleistocene records of carbonate dissolution and accumulation. The authors examination of multiple dissolution indices indicate that, at least for the last 150,000 years, dissolution of carbonate in the Venezuela Basin has been more intense during interglacial than glacial periods, a pattern opposite to more general observations from the deep Atlantic and Gulf of Mexico. By virtue of its shallow sill depth (1815 m), the Venezuela Basin is relatively isolated from the mainstream of Atlantic thermohaline circulation, and presently is filled with homogeneous, relatively warm (3.8/sup 0/C) waters primarily derived from Upper North Atlantic Deep Water. During the last glacial, the enhanced preservation of carbonate in the Venezuela Basin suggests the presence of a less corrosive, more oxygenated water mass in the Atlantic near sill depth. However, this simple interpretations is potentially complicated by past changes in the rain of biogenic materials from surface waters to the deep basin in what must be an essentially closed system below sill depth. Their observations of increased interglacial dissolution may help to explain previously noted discrepancies in the local glacial to interglacial amplitude of delta/sup 18/O variations recorded by coccoliths and planktonic foraminifera.

  3. 78 FR 58556 - Silicomanganese From India, Kazakhstan, and Venezuela

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-24

    ... Venezuela. Background The Commission instituted these reviews on October 1, 2012 (77 FR 59970) and determined on January 4, 2013 that it would conduct full reviews (78 FR 4437, January 22, 2013). Notice of... Commission, Washington, DC, and by publishing the notice in the Federal Register on February 21, 2013 (78...

  4. Pedernales oilfield, eastern Venezuela: The first 100 years

    SciTech Connect

    Gluyas, J.; Oliver, J.; Wilson, W.

    1996-08-01

    Petroleum seeps and surface tar mats attracted oil explorers to Pedernales in eastern Venezuela 100 years ago. Commercial production from the Pedernales Field was established by Creole in 1933. In three production periods, broken by WWII and the end of the Creole-Texaco refining contract, Creole and Lagoven produced about 60 MMSTB from about 60 wells in about 60 years. Peak production was in the late 1950s, when the field delivered 12,000 BOPD. Production was stopped in 1986. In March 1993, BP Venezuela acquired the license to reactivate Pedernales on behalf of Lagoven, and BP`s first well in the field was drilled in August 1994. A second was completed in early 1995. The production from each well was sufficiently encouraging for commerciality to be declared in March 1995. Phase 1 of the field reactivation demanded a production rate of 11,500 BOPD. As of now (September, 1995) six wells, including one gas disposal well, have been completed. Wells have been placed using a combination of old well data and mapping based on a close spaced 2D seismic survey shot in early 1994. Results from these first few wells indicate that the required production rate will be achieved despite severely depleted reservoir pressures. This paper tells the story of reactivation and re-evaluation of one of eastern Venezuela`s oldest oilfields.

  5. version 25Apr11b From Saudi Arabia to Venezuela

    E-print Network

    O'Donnell, Tom

    SYLLABUS version 25Apr11b From Saudi Arabia to Venezuela: Energy Resources, Market Factors Blogs: 1. Global Fracking http://globalfracking.blogspot.com/ 2. Middle East and North African Oil http. They will understand the natural-resource and political-economic constraints underlying contemporary energy geo

  6. Clay mineralogy of surface sediments as a tool for deciphering river contributions to the Cariaco Basin (Venezuela)

    E-print Network

    Meyers, Steven D.

    Basin (Venezuela) V. Bout-Roumazeilles,1 A. Riboulleau,1 E. Armynot du Châtelet,1 L. Lorenzoni,3 N for deciphering river contributions to the Cariaco Basin (Venezuela), J. Geophys. Res. Oceans, 118, doi:10

  7. A new species of Coespeletia (Asteraceae, Millerieae) from Venezuela

    PubMed Central

    Diazgranados, Mauricio; Morillo, Gilberto

    2013-01-01

    Abstract A new species of Coespeletia from the páramos of Mérida (Venezuela) is described here. This species, named Coespeletia palustris, is found in a few marshy areas of the páramo. It is closely related to C. moritziana, but differs from it in a smaller number of florets in the capitula, larger ray flowers with longer ligulae and longer linguiform appendages, smaller pollen grains, larger cypselae, ebracteate scapes, leaves and inflorescences with more whitish indumentum, larger leaf sheaths, and marshy habitat. PMID:24399890

  8. Curie point depth in Venezuela and the Eastern Caribbean

    NASA Astrophysics Data System (ADS)

    Arnaiz-Rodríguez, Mariano S.; Orihuela, Nuris

    2013-04-01

    We estimate the Curie point depth (CPD) variations of Venezuela (continental crust, South American plate) and the Eastern Caribbean (oceanic crust, Caribbean Plate) by using spectral analysis of the magnetic anomalies, extracted from the 2010 Enhanced Magnetic Model (EMM2010), available at the National Oceanic and Atmospheric Administration (NOAA). To test the reliability of the spectral content of this model, for a small region, we compare he CPD derived from the EMM2010 against the one from aeromagnetic data. We also compile heat flow data from previous studies to correlate them with the CPD lateral variations. The estimations show that the CPD in Venezuela and the Eastern Caribbean ranges between 54 and 17 km. The mean depth value within the continental crust is around 38 km. On the Guayana Shield, it has a mean value of 42 km and reaches a maximum of 54 km. As the Moho depth is at most 50 km, the upper mantle beneath the craton is magnetized. Continental lateral variations appear to be linked to the isostatic state and age of the different provinces, and mark the limit between the Precambrian and the Paleozoic provinces. The Maracaibo Basin is revealed as a thermally stable one with a constant CPD, while the Eastern Venezuela Basin is thermally affected. Most of the Eastern Caribbean seems stable, with a large non-perturbed area with a mean CPD value of 23 km. As the crustal thickness is at most 20 km, the isotherm is located within the upper mantle. A CPD minimum located on the Lesser Antilles arc is concentrated in its northern part, and can be related to the subduction zone that is most active. Finally, a shallow area within the Eastern Caribbean corresponds to the thin crust region in the Venezuela Basin, although it might be linked to mantle dynamics.

  9. Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela

    SciTech Connect

    Salas, A. Rangel; Viloria, T.; Sajo-Bohus, L.; Barros, H.; Greaves, E. D.; Palacios, D.

    2007-10-26

    Maracaibo Lake is one of the most important water basing and oil producing regions in Venezuela. Changes in the local environment have been monitored for chemical pollution in the past. For this study we selected a set of sediment samples collected in the shore and analyzed for its radioisotope content. Results show the gamma emitting isotopes distribution. Isotopes concentrations have been determined within the natural K, Th and U families.

  10. Geologic map of the Venezuela part of the Puerto Ayacucho 2 degrees x 3 degrees Quadrangle, Amazonas Federal Territory, Venezuela

    USGS Publications Warehouse

    Wynn, Jeffrey C.; Olmore, Steven D.; Mendoza, Vicente; García, Andrés; Rendon, Ines; Estanga, Yasmin; Rincon, Haydee; Martinez, Felix; Lugo, Elis; Rivero, Nelson; Schruben, Paul G.

    1994-01-01

    This map is one of a series of 1:500,000-scale maps that, along with several other products, stems from a cooperative agreement between the U.S. Geological Survey (USGS) and the Corporacion Venezolana de Guayana, Tecnica Minera, C.A. (TECMIN), a Venezuelan Government-owned mining and mineral exploration company. The agreement covered cooperative work carried out in the Precambrian Shield of southern Venezuela during 1987-1991 and included a geologic and mineral resource inventory, technology transfer, and scientific training (Wynn and others, in press). The Precambrian Guayana Shield (Escudo de Guyana, not to be confused with the neighboring country of Guyana) includes some of the oldest known rocks in the world (Mendoza, 1977) and also covers parts of neighboring Guyana, Surinam, French Guiana, Columbia, and Brazil. In Venezuela, it underlies most of Bolivar state and all of the Amazonas Federal Territory (see index map).

  11. Bachaquero-01 reservoir, Venezuela-increasing oil production by switching from cyclic steam injection to steamflooding using horizontal wells 

    E-print Network

    Rodriguez, Manuel Gregorio

    1999-01-01

    The Bachaquero-01 reservoir of the Lagunillas field is located in the eastern part of the Maracaibo Lake, Venezuela. The field is operated by the national oil company of Venezuela, PDVSA (Petroleos de Venezuela, S.A.). The Bachaquero-01 heavy oil...

  12. Development, Antibiotic Production, and Ribosome Assembly in Streptomyces venezuelae Are Impacted by RNase J and RNase III

    E-print Network

    Elliot, Marie A.

    Development, Antibiotic Production, and Ribosome Assembly in Streptomyces venezuelae Are Impacted model system Streptomyces venezuelae. We show that each enzyme makes a unique contribution to the growth and development of S. venezuelae and further affects the secondary metabolism and antibiotic production

  13. Comparison of species-specific oxygen isotope paleotemperature equations: Sensitivity analysis using planktonic foraminifera from the Cariaco Basin, Venezuela

    E-print Network

    Meyers, Steven D.

    using planktonic foraminifera from the Cariaco Basin, Venezuela Katherine E. Wejnert a, , Robert C, Venezuela a b s t r a c ta r t i c l e i n f o Article history: Received 6 December 2011 Received in revised biweekly sediment trap samples collected in Cariaco Basin, Venezuela between 2003 and 2008. Sixteen

  14. Interruption of Onchocerca volvulus transmission in Northern Venezuela

    PubMed Central

    2013-01-01

    Background Onchocerciasis is caused by Onchocerca volvulus and transmitted by Simulium species (black flies). In the Americas, the infection has been previously described in 13 discrete regional foci distributed among six countries (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela) where more than 370,000 people are currently considered at risk. Since 2001, disease control in Venezuela has relied on the mass drug administration to the at-risk communities. This report provides empirical evidence of interruption of Onchocerca volvulus transmission by Simulium metallicum in 510 endemic communities from two Northern foci of Venezuela, after 10–12 years of 6-monthly Mectizan® (ivermectin) treatment to all the eligible residents. Methods In-depth entomologic and epidemiologic surveys were serially conducted from 2001–2012 in selected (sentinel and extra-sentinel) communities from the North-central (NC) and North-east (NE) onchocerciasis foci of Venezuela in order to monitor the impact of ivermectin treatment. Results From 2007–2009, entomological indicators in both foci confirmed that 0 out of 112,637 S. metallicum females examined by PCR contained L3 infection in insect heads. The upper bound of the 95% confidence intervals of the infective rate of the vector reached values below 1% by 2009 (NC) and 2012 (NE). Additionally, after 14 (NC) and 22 (NE) rounds of treatment, the seasonal transmission potential (±UL CIs) of S. metallicum was under the critical threshold of 20 L3 per person per season. Serological analysis in school children < 15 years-old demonstrated that 0 out of 6,590 individuals were harboring antibodies to Ov-16. Finally, epidemiological surveys made during 2010 (NC) and 2012 (NE) showed no evidence of microfilariae in the skin and eyes of the population. Conclusions These results meet the WHO criteria for absence of parasite transmission and disease morbidity in these endemic areas which represent 91% of the population previously at-risk in the country. Consequently, the two Northern foci are currently under post-treatment onchocerciasis surveillance status in Venezuela. PMID:24499653

  15. Paleoseismology in Venezuela: Objectives, methods, applications, limitations and perspectives

    NASA Astrophysics Data System (ADS)

    Audemard M., Franck A.

    2005-10-01

    The privileged location of Venezuela along an active interplate deformation belt, despite of being a "so-called" developing country, has led to a long paleoseismic tradition as attested by 45 trench assessments since 1968. Since then, a first 2-trench study was carried out by the American Woodward-Clyde company across the Oca fault at Sinamaica. Since 1980, all further paleoseismic studies have been performed by FUNVISIS and the Uribante-Caparo hydroelectric project (southern Mérida Andes) became their first assessment where 22 huge trenches were bulldozer-dug. Except for these Compañía Anónima de Administración y Fomento Eléctrico (CADAFE) financed trenches and two others, all other assessments were for Petróleos de Venezuela S. A. -PDVSA-. In this paper, geographic and geologic factors, as well as logistic limitations, conditioning success in paleoseismic studies by trenching, shall be discussed based on the Venezuelan experience developed over the years. The scientific contribution of this approach refer to: confirmation of Holocene fault activity, slip-per-event and average slip rate of a given fault (or segment), seismic potential (repeat of maximum credible earthquakes) of known faults, fault segmentation, fault interaction as consequence of stress loading by stick-slip on contiguous faults, time-space distribution of seismic activity along a given tectonic feature, seismotectonic association of historical earthquakes and landscape evolution on the short term and its implications on the long-term evolution (poorly discussed since this is really part of the field of Neotectonics). In recent years (since 1999), a new approach has been introduced in Venezuela consisting in complementing the seismic history derived from trenching studies with the evaluation of seismically induced perturbations in the continuous Quaternary sedimentary record of (either active or fossil) lakes. The future of this discipline in Venezuela heads to more trenching and lake coring in order to gather more data on the previously mentioned aspects. Other paleoseismic approaches have been developed very little in Venezuela since either climate or the geodynamic setting do not favor their application.

  16. Radioactive source materials in Los Estados Unidos de Venezuela

    USGS Publications Warehouse

    Wyant, Donald G.; Sharp, William N.; Rodriguez, Carlos Ponte

    1953-01-01

    This report summarizes the data available on radioactive source materials in Los Estados Unidos de Venezuela accumulated by geologists of the Direccions Tecnica de Geolgia and antecedent agencies prior to June 1951, and the writers from June to November 1951. The investigation comprised preliminary study, field examination, office studies, and the preparation of this report, in which the areas and localities examined are described in detail, the uranium potentialities of Venezuela are summarized, and recommendations are made. Preliminary study was made to select areas and rock types that were known or reported to be radioactive or that geologic experience suggests would be favorable host for uranium deposits, In the office, a study of gamma-ray well logs was started as one means of amassing general radiometric data and of rapidly scanning many of ye rocks in northern Venezuela; gamma-ray logs from about 140 representative wells were examined and their peaks of gamma intensity evaluated; in addition samples were analyzed radiometrically, and petrographically. Radiometic reconnaissance was made in the field during about 3 months of 1951, or about 12 areas, including over 100 localities in the State of Miranda, Carabobo, Yaracuy, Falcon, Lara, Trujillo, Zulia, Merida, Tachira, Bolivar, and Territory Delta Amacuro. During the course of the investigation, both in the filed and office, information was given about geology of uranium deposits, and in techniques used in prospecting and analysis. All studies and this report are designed to supplement and to strengthen the Direccion Tecnica de Geologias's program of investigation of radioactive source in Venezuela now in progress. The uranium potentialities of Los Estados de Venezuela are excellent for large, low-grade deposits of uraniferous phospahtic shales containing from 0.002 to 0.027 percent uranium; fair, for small or moderate-sized, low-grade placer deposits of thorium, rare-earth, and uranium minerals; poor, for high-grade hydrothermal pitchblende deposits; and highly possible for small, medium- to high-grade despots of carnotite-or copper-uranium bearing sandstone. Recommendations for the Venezuelan uranium program include 1) the systematic collection of a mass general radiometric data by examining sample collections, expanding the gamma-ray program, encouraging the use of Geiger counter by field geologists, and by enlisting the aid of the general public; 2) , the examination of specific areas or localities, chosen on the basis of geologic favorability from the results of the amassing of data, or obtained by hints and rumors; 3), the organization of a unit within the Direccion Tecnica de Geologica to direct, collection, and collate metric data. It is emphasized that to be most fruitful the program requires the application of sounds and imaginative geologic theory.

  17. A new species of Hemerobiella Kimmins (Neuroptera, Hemerobiidae) from Venezuela with notes on the genus.

    PubMed

    Sosa, Francisco; Lara, Rogéria I R; Martins, Caleb C

    2015-01-01

    Hemerobiella periotoi Sosa & Lara sp. nov. is described from Venezuela. The new species was collected at the edges of a mature cloud forest in Lara state. This is the third species known in Hemerobiella Kimmins, and the second recorded from Venezuela. Additionally, new Venezuelan records and illustrations of H. oswaldi Monserrat, as well as, a key to Hemerobiella species are provided. PMID:26624319

  18. A new species and first record of Cotinis Burmeister (Coleoptera: Scarabaeidae: Cetoniinae) for Venezuela.

    PubMed

    Gasca-Álvarez, Héctor Jaime; Deloya, Cuauhtémoc

    2015-01-01

    A new Cotinis Burmeister (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini) species from Venezuela is described and illustrated. The new species is compared with Cotinis barthelemyi (Gory & Percheron) from Colombia. The Neotropical distribution of Cotinis is expanded to Venezuela. A revised key to the species of Cotinis is provided in both English and Spanish. PMID:25947767

  19. 78 FR 77423 - Ferrosilicon From the Russian Federation and Venezuela: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... Russian Federation and Venezuela: Initiation of Antidumping Duty Investigations, 78 FR 49471 (August 14, 2013) (``Initiation Notice''). \\2\\ See id., 78 FR at 49474. As explained in the memorandum from the... International Trade Administration Ferrosilicon From the Russian Federation and Venezuela: Postponement...

  20. Using the Five Themes of Geography To Teach about Venezuela and Mexico.

    ERIC Educational Resources Information Center

    Sunal, Cynthia Szymanski; Christensen, Lois

    Activities that employ the five themes of geography--location, place, relationships within places, movement, and regions--to teach about Venezuela and Mexico are described in this document. Each theme has objectives, a list of materials, and three types of activities--exploration, invention, and expansion. Background information on Venezuela and…

  1. Earnings and Education in Venezuela: An Update from the 1987 Household Survey.

    ERIC Educational Resources Information Center

    Psacharopoulos, George; Alam, Asad

    1991-01-01

    Uses data from Venezuela's 1987 Household Survey to update returns to education and compare them to 1975 and 1984 figures. Returns to education have been maintained despite the educational explosion occurring in Venezuela during the period investigated. Although higher education is most heavily subsidized, primary education remains the most…

  2. 78 FR 4437 - Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To Conduct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... the domestic interested party group response to its notice of institution (77 FR 59970, October 1... Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To Conduct Full Five-Year... silicomanganese from India, Kazakhstan, and Venezuela would be likely to lead to continuation or recurrence...

  3. 78 FR 9034 - Silicomanganese From India, Kazakhstan, and Venezuela: Final Results of the Expedited Second...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-07

    ..., Kazakhstan, and Venezuela, 67 FR 36149 (May 23, 2002). On October 1, 2012, the Department initiated the... (``the Act''). See Initiation of Five-Year (``Sunset'') Review, 77 FR 59897 (October 1, 2012) (``notice... International Trade Administration Silicomanganese From India, Kazakhstan, and Venezuela: Final Results of...

  4. 78 FR 60846 - Silicomanganese From India, Kazakhstan, and Venezuela: Continuation of Antidumping Duty Orders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... FR 59897 (October 1, 2012). \\2\\ See Silicomanganese From India, Kazakhstan, and Venezuela: Final Results of the Expedited Second Sunset Reviews of the Antidumping Duty Orders, 78 FR 9034 (February 7, 2013). \\3\\ See Silicomanganese From India, Kazakhstan, and Venezuela: Determination, 78 FR...

  5. El objetivo de este curso es poner de manifiesto la importancia del estudio

    E-print Network

    El objetivo de este curso es poner de manifiesto la importancia del estudio paleoecológico en Ecología, sobre todo en lo referente a la dimensión tiempo. No es un curso sólo de reconstrucción-inscripción: 30 abril 2015 Matrícula: 100,00 Contacto: Núria Cañellas (nuriacatcb@gmail.com) PALEOECOLOGÍA Curso

  6. Zonation of hydric regimens in Venezuela based on rainfall characteristics

    NASA Astrophysics Data System (ADS)

    Lobo, D.; Verbist, K.; Gabriels, D.; Puche, M.; Bracho, G.; Soto, G.; Santibañez, F.

    2012-04-01

    The climate in Venezuela is a product of a complex combination and interaction of meteorological and geographical factors such as the geographic location either north of Ecuador or in the tropics, and the presence of warm waters north and northeast, a vast tropical moist forest south and a mountain range west. In order to delimit the different climatic zones in Venezuela, a zoning of water regimes were used to classify climate indices primarily on rainfall parameters. A first index used was the length of a dry period, corresponding to the number of months in the year when precipitation is less than half of the reference evapotranspiration. Another index was the Aridity Index (Ia) proposed by UNEP (1997), for which calculations were based on values of average annual rainfall of the stations of the FAO database (1984, 2000). The reference evapotranspiration (ETo) was calculated by the CIRH program version 2.0 (Santibanez, 2005), which allows the calculation of ETo by the FAO (Allen et al.1998) or by the original Penman-Monteith formula, by Thornthwaite (1948), Turc (1961) or by Ivanov (1996). The results show that the distribution of the climatic regimes of Venezuela is determined by rainfall patterns. The central region is dominated by a sub-humid regime surrounded by a humid regime. The southern region is dominated by hyper-humid, hydric and hyper-hydric regimes, as well as the most western and eastern regions. In the northern and central-western regions the semiarid, arid and hyper-arid regimes dominate.

  7. Natural Host Relationships of Hantaviruses Native to Western Venezuela

    PubMed Central

    Milazzo, Mary L.; Duno, Gloria; Utrera, Antonio; Richter, Martin H.; Duno, Freddy; de Manzione, Nuris

    2010-01-01

    Abstract Strains of Caño Delgadito virus (CADV) and Maporal virus (MAPV) were isolated from 25 (8.9%) of the 280 rodents captured on farms in 1997 in western Venezuela. The results of analyses of laboratory and zoographic data indicated that Alston's cotton rat (Sigmodon alstoni) is the principal host of CADV, horizontal virus transmission is the dominant mode of CADV transmission in Alston's cotton rat in nature, a pygmy rice rat (Oligoryzomys sp.) is the principal host of MAPV, and the natural host relationships of CADV and MAPV are highly specific. PMID:20055578

  8. Present Status of Historical Seismicity Studies in Colombia and Venezuela

    NASA Astrophysics Data System (ADS)

    Sarabia, A.; Cifuentes, H.; Altez Ortega, R.; Palme, C.; Dimate, C.

    2013-05-01

    After the publication of the SISRA (CERESIS-1985) regional project, a unified catalog of seismic parameters and intensities for South America, researchers in historical seismicity have continued advancing on different scales in the area of this study of seismic hazard. The most important initiatives carried out in this area in Colombia and Venezuela can be grouped as follows: a) Reviews of destructive earthquakes in national and international historic archives, principally by Altez and FUNVISIS in Venezuela and Espinosa, Salcedo, and Sarabia et al in Colombia, leading to the preparation of seismologic catalogues, scientific and dissemination articles, reports, books, among others. b) Organization and systematization of historic information to develop public domain data bases and information, specifically the Historic Seismologic Teleinformation System in Venezuela, carried out between 2004 and 2008 under the coordination of Christl Palme and accessible on-line: http://sismicidad.ciens.ula.ve. As well, the "Historia Sísmica de Colombia 1550-1830" (Seismic History in Colombia 1550-1830) data base, in CD-ROM, by Espinosa Baquero (2003) and the historic seismicity information system of Colombia (Servicio Geológico Colombiano-Universidad Nacional de Colombia), published on the internet in 2012: http://agata.ingeominas.gov.co:9090/SismicidadHistorica/. c) Macroseismic studies for the development of intensity attenuation equations and the quantification and revaluation of basic historic earthquake parameters using isoseismal maps (Rengifo et al., Palme et al., Salcedo et al., among others) and procedures such as Boxer and Bakun & Wentworth (Palme et al., Dimaté, among others), which have produced significant changes in the parameters of some of the large earthquakes. d) Symposiums of researchers to promote interest and development in the discipline, including Jornadas Venezolanas de Sismología Histórica (Venezuelan Congress of Historical Seismology), held periodically between 1997 and 2012, the year of the sixth edition. As well, national and international research groups have been formed to work actively on global projects, such as the Geophysics Laboratory of Universidad de Los Andes in Venezuela. In the future, international groups will be formed to jointly treat issues including localization and size of destructive events along borders, common scales for the evaluation of intensities, integrated data bases, etc. Additionally the methods employed will be validated by paleoseismology, neotectonics and instrumental seismicity, among others.

  9. José María Vargas (1786-1854): Reformer of anatomical studies in Venezuela.

    PubMed

    Reverón, Rafael Romero

    2014-03-01

    José María Vargas (1786-1854): Venezuelan medical doctor, surgeon, optician, anatomist, chemist, botanist, professor, geologist, mineralogist, and mathematician. Second President of Venezuela (1835-1836), First republican dean, he reformed medicine studies in 1827 establishing human anatomical dissection in the Universidad Central de Venezuela where he taught human anatomy between 1827 and 1853 along with surgery and chemistry. In 1838, he wrote Curso de Lecciones y demostraciones Anatómicas, the first book on the subject printed in Venezuela for the teaching of human anatomy. PMID:23650143

  10. Assessing earthquake catalogues in Venezuela by analyzing time series data

    NASA Astrophysics Data System (ADS)

    Vasquez, R.; Granado, C.

    2011-12-01

    We applied the Mann-Kendall non-parametric test for identifying significant trends in time series data regarding the seismicity patterns in Venezuela during the period 2001-2010. The entire seismicity region is divided in three areas to perform the test: 1) West with 12774 seismic events; 2) Center for a total of 909 earthquakes and 3) East with 6382 earthquakes. We analyzed the catalogues for every sub region to obtain the b value of the Gutenberg-Richter law based on the maximum likelihood method and the annual magnitude of completeness (Mc) by using the maximum curvature method (MAXC). We assessed statistically the analysis of Z for the time series consisting of the b value and Mc in the three subsets of earthquakes. The confidence interval of this study was 90%. This approach is useful to analyze the performance characteristics of the Venezuelan seismic network and the associated regional catalogues. The results lead to conclude that the Central part of Venezuela does not show an statistically significant trend of the seismicity or Mc, while western region has a decreasing trend in the Mc estimation but no variations in terms of the seismicity. Only the Eastern region presents an increasing trend in its seismicity and Mc values.

  11. Raptor abundance and distribution in the Llanos wetlands of Venezuela

    USGS Publications Warehouse

    Jensen, W.J.; Gregory, M.S.; Baldassarre, G.A.; Vilella, F.J.; Bildstein, K.L.

    2005-01-01

    The Llanos of Venezuela is a 275 000-km2 freshwater wetland long recognized as an important habitat for waterbirds. However, little information exists on the raptor community of the region. We conducted raptor surveys in the Southwestern and Western Llanos during 2000-02 and detected 28 species representing 19 genera. Overall, areas of the Llanos that we sampled contained 52% of all raptor species and more than 70% of the kites, buteos, and subbuteos known to inhabit Venezuela. Regional differences in the mean number per route for four of the 14 most common species, the Crested Caracara (Caracara plancus), Black-collared Hawk (Busarellus nigricollis), American Kestrel (Falco sparverius), and Osprey (Pandion haliaetus), were significant (P < 0.0018) in relation to the wet or dry seasons. Of the 14 less common species, six were detected in only one season (wet or dry). The Southwestern and Western regions of the Llanos support a rich raptor community composed primarily of nonmigratory wetland-dependent and upland-terrestrial species. ?? 2005 The Raptor Research Foundation, Inc.

  12. Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

    PubMed Central

    Carrasco, Hernán J.; Segovia, Maikell; Llewellyn, Martin S.; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E.; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A.; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A.; Feliciangeli, M. Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela. PMID:22745843

  13. A reservoir characterization for a complex multilayered system in Eastern Venezuela 

    E-print Network

    Avila, Carmen Esther

    1998-01-01

    and permeability by integration of all available data. In this research, we have characterized a multilayered reservoir located in eastern Venezuela. A methodology was developed to estimate the distribution of reservoir properties in uncured intervals and welts...

  14. 78 FR 4437 - Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To Conduct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ...orders on silicomanganese from India, Kazakhstan, and Venezuela...reviews on subject imports from India and Kazakhstan were inadequate...imports of silicomanganese from India and Kazakhstan to promote administrative efficiency in light of its decision to conduct...

  15. Biological and phylogenetic characterization of a genotype VII Newcastle disease virus from Venezuela: Efficacy of vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we describe the characterization a virulent genotype VII Newcastle disease virus (NDV) from Venezuela and evaluate the efficacy of heterologous genotype commercial vaccination under field and controlled rearing conditions. Biological pathotyping and molecular analysis were applied. Results sh...

  16. Correlation of the Jurassic through Oligocene Stratigraphic Units of Trinidad and Northeastern Venezuela

    SciTech Connect

    Algar, S.; Erikson, J.P.

    1995-04-01

    The Jurassic through Oligocene stratigraphies of Trinidad and the Serrenia del Interior of eastern Venezuela exhibit many similarities because of their proximity on the passive continental margins of northeastern South America. A slightly later subsidence in eastern Venezuela, and the generally deeper-water sedimentation in Trinidad, is interpreted to be the result of a serration of the original rift margin, producing an eastern Venezuela promontory and Trinidadian re-entrant. We interpret these serrations to be the result of oblique (NW-SE) spreading of North and South America during Middle and late Jurassic time. The stratigraphies of northeastern Venezuela and Trinidad contrast in the Hauterivan-Albian interval, with dynamic shallow shelf environments prevailing in the Serrenia del Interior and deeper marine submarine-fan deposition in Trinidad. Both areas develop middle to Upper Cretaceous source rocks during a time of eustatic sea level high and widespread oceanic anoxia. 15 refs., 4 fig.

  17. Different methodologies for obtaining a permeability distribution in the Misoa Formation, Venezuela 

    E-print Network

    Garcia, Ivette

    1998-01-01

    correlation as a function of porosity and grain diameter based on systematic packing. These two methodologies have been used to determine a permeability profile in the Misoa Formation, Venezuela. Formation permeability controls the strategies involving well...

  18. Review of the Berosus Leach of Venezuela (Coleoptera, Hydrophilidae, Berosini) with description of fourteen new species

    E-print Network

    Oliva, Adriana; Short, Andrew E. Z.

    2012-07-06

    The species of the water scavenger beetle genus Berosus Leach occurring in Venezuela are reviewed. Thirty-six species are recorded, including fifteen new species, fourteen of which are described here as new: Berosus aragua sp. n., Berosus...

  19. Characterization of gas condensate reservoirs using pressure transient and production data - Santa Barbara Field, Monagas, Venezuela 

    E-print Network

    Medina Tarrazzi, Trina Mercedes

    2003-01-01

    This thesis presents a field case history of the integrated analysis and interpretation developed using all of the available petrophysical, production, and well test data from the condensate zone of Block A, Santa Barbara Field (Monagas, Venezuela...

  20. Decentralization and Regionalization in the Ministry of Education: The Case of Venezuela

    ERIC Educational Resources Information Center

    Hanson, Mark

    1976-01-01

    This research is an effort to analyze the process of organizational change as it takes place within one segment of the public administration mechanism in Venezuela--The Ministry of Education. (Editor/RK)

  1. A Descriptive Chronology of Films by Women in Venezuela, 1952-92.

    ERIC Educational Resources Information Center

    Schwartzman, Karen

    1993-01-01

    Offers an annotated chronology of Venezuelan films, representing a first step toward a general history of women's filmmaking in Venezuela. Suggests that the participation of women directors closely follows the curve of national film production in general. (RS)

  2. Ecology of the river dolphin, Inia geoffrensis, in the Cinaruco River, Venezuela 

    E-print Network

    McGuire, Tamara Lee

    1995-01-01

    The Cinaruco River is a tributary of the Orinoco River, and forms the southern boundary of Venezuela's newest national park, Santos Luzardo. Like other rivers of this region, the Cinaruco River undergoes an extreme seasonal flood cycle. River...

  3. Identification and characterization of Hydraulic Flow Units in the San Juan Formation, Orocual Field, Venezuela 

    E-print Network

    Deghirmandjian, Odilia

    2001-01-01

    This thesis focuses on the integration of core and well log data in order to provide a petrophysical characterization of the Hydraulic Flow Units (HFU) in the San Juan Formation, Orocual Field, Venezuela. We used three separate approaches...

  4. Four new species of Andean Pilea (Urticaceae), with additional notes on the genus in Venezuela

    PubMed Central

    Dorr, Laurence J.; Stergios, Basil

    2014-01-01

    Abstract Four new species of Pilea (Urticaceae) from the Andes of Venezuela are described and illustrated: Pilea matthewii sp. nov., Pilea miguelii sp. nov., Pilea nicholasii sp. nov., and Pilea nidiae sp. nov. The affinities of these species and their positions within the informal classifications of Pilea proposed by Weddell and Killip are discussed. Notes on other species of Pilea found in Venezuela also are presented. PMID:25383012

  5. Venezuela's stake in US refining may grow: xenophobia addressed

    SciTech Connect

    Not Available

    1987-09-23

    Is this an invasion of U.S. oil industry sovereignty, or a happy marriage of upstream and downstream between US and foreign interests. Venezuela, a founding member of the Organization of Petroleum Exporting Countries who has also been a chief supplier to the US during times of peace and war, now owns half of two important US refining and marketing organizations. Many US marketers have felt uneasy about this foreign penetration of their turf. In this issue, for the sake of public information, the entire policy statement from the leader of that Venezuelan market strategy is provided. This issue also contains the following: (1) ED refining netback data for the US Gulf and West Coasts, Rotterdam, and Singapore as of late September, 1987; and (2) ED fuel price/tax series for countries of the Eastern Hemisphere, Sept. 19 edition. 4 figures, 6 tables.

  6. Postepizootic Persistence of Venezuelan Equine Encephalitis Virus, Venezuela

    PubMed Central

    Navarro, Juan-Carlos; Medina, Gladys; Vasquez, Clovis; Coffey, Lark L.; Wang, Eryu; Suárez, Alexander; Biord, Hernán; Salas, Marlene

    2005-01-01

    Five years after the apparent end of the major 1995 Venezuelan equine encephalitis (VEE) epizootic/epidemic, focal outbreaks of equine encephalitis occurred in Carabobo and Barinas States of western Venezuela. Virus isolates from horses in each location were nearly identical in sequence to 1995 isolates, which suggests natural persistence of subtype IC VEE virus (VEEV) strains in a genetically stable mode. Serologic evidence indicated that additional outbreaks occurred in Barinas State in 2003. Field studies identified known Culex (Melanoconion) spp. vectors and reservoir hosts of enzootic VEEV but a dearth of typical epidemic vectors. Cattle serosurveys indicated the recent circulation of enzootic VEEV strains, and possibly of epizootic strains. Persistence of VEEV subtype IC strains and infection of horses at the end of the rainy season suggest the possibility of an alternative, cryptic transmission cycle involving survival through the dry season of infected vectors or persistently infected vertebrates. PMID:16485478

  7. Swarms in Venezuela: characterization of the involved seismicity

    NASA Astrophysics Data System (ADS)

    Vasquez, R.; Granado, C.; Borges, N.

    2013-05-01

    A swarm is a gradual increase and decay of seismicity in time forming a cluster of seismic events without the occurrence of a particular mainshock or major earthquake. In Venezuela, there are few sequences of the swarm type in the instrumental age of seismology. These swarms are not related to volcanic activity and there is few studied evidence to lead the understanding of the triggering mechanism of the venezuelan swarm activity. We compile instrumental information in order to reassess and compare five swarms occurred in 1989, 1991, 1995, 2006 and 2011. Four of these swarms are located in areas where predominant quaternary faults generate most of the background seismicity. We investigated the statistical properties of these swarms and activity patterns under the frequency size distribution and the interevent-time distribution to study the time between two consecutive events as a stationary point process.

  8. Seismic anisotropy and mantle flow beneath western Venezuela

    NASA Astrophysics Data System (ADS)

    Masy, J.; Niu, F.; Levander, A.

    2009-12-01

    We measured shear wave splitting from SKS and SKKS data recorded by the national seismic network of Venezuela and a linear broadband PASSCAL/Rice seismic array across the Merida Andes. The linear array was installed as a second phase of the passive seismic component of the BOLIVAR project (Broadband Onshore-offshore Lithospheric Investigation of Venezuela and the Antilles arc Region) to better understand the complicated regional tectonics in western Venezuela. Polarization direction (?) of the faster S wave and delay time (?t) between the fast and slow wavelets from 20 stations were obtained using a stacking method proposed by Wolfe and Silver (1998). For each station, SKS or SKKS waveform data from 2 to 36 earthquakes, mostly from the Tonga subduction zone, were selected for splitting analysis. We assumed that shear wave splitting observed at each station is caused by upper mantle seismic anisotropy beneath the station. The best splitting parameters (?,?t) were estimated when the summed eigenvalue ratio ?(SNRi[?2i(?,?t)/?1i(?,?t)]) of the covariance matrix of the corrected particle motion reaches its minimum. We used signal-to-noise ratio (SNR) calculated from a noise time window before SKS as the weight of the summation. The fast polarization directions can be divided into 3 zones, all in agreement with local GPS data: The first zone is the stations north of the dextral strike-slip Oca fault, an extinct part of the San Sebastian-El Pilar plate boundary zone. These stations show the largest split times (1.6-2.0s), oriented in a roughly EW direction, and are similar to splitting observations made further to the east along the strike slip plate boundary. Zone two is the Maracaibo block, bounded on the southeast by the right lateral Bocono fault, where split orientations are at N45°E, suggesting that the observed seismic anisotropy is likely caused by lithospheric deformation parallel to the Bocono. Zone three is east of the Bocono fault inside the Barinas-Apure Basin, where the measured split times are smaller (0.6-1.0s) with an EW fast direction that is consistent with those observed at the Guarico Basin, Maturin Basin and the Guayana shield in the east (Growdon et al., 2009), and are interpreted as orientation with the motion of the continent. Russo and Silver (1994) proposed that the rollback of the Nazca plate induced a trench-parallel NS flow that passes around the northwest corner of the subducting plate and along the northern edge of South America, forming an eastward flow beneath the southern Caribbean plate. The observed seismic anisotropy in western Venezuela can be roughly explained by a combination of this corner flow, the westward drift of the South America continent due to the opening of Atlantic Ocean, modulated by the northward escape of the Maracaibo block.

  9. Potential for Great Thrust Earthquakes in NE Colombia & NW Venezuela

    NASA Astrophysics Data System (ADS)

    Bilham, R. G.; Mencin, D.

    2013-05-01

    Sixty-five percent of the ?19 mm/yr eastward velocity of the Caribbean Plate north of Aruba and the Guajira peninsula relative to the South American plate is accommodated by dextral slip on the Bocono Fault system in NW Venezuela at 12±1 mm/yr, the remaining ~3 mm/yr of shear apparently distributed to the NW of the fault (Perez et al., 2011). The N40E strike of the Bocono fault system, however, requires that 10.6±1 mm/yr of convergence should accompany this partitioned dextral shear, but GPS measurements reveal that less than 25% of this convergence occurs across the Venezuelan Andes. The remaining 6-8 mm of convergence is presumably accommodated by incipient subduction between the Bocono fault and a trench 300 km NW of the northern coast of Colombia. Hence NW Venezuela and NE Colombia may occasionally host great earthquakes. Our current poor understanding of the geometry of the plate interface permits the plate to be locked 300 km down-dip and possibly 600 km along-strike, and if the plate slips in 10 m ruptures it could do so every 1200 years in a M~9 earthquake. No great earthquake has occurred since 1492, since when ~4 m of potential slip has developed, but should slip occur on just 10% of the hypothesized décollement (100x150 km) it could do so now in an Mw=8.2 earthquake. In that a potential Mw>8 earthquake poses a future seismic and tsunami threat to the Caribbean it is important to examine whether great earthquakes have occurred previously near the NW Venezuela coast. It is possible that creep accommodates the entire convergence signal, since there is no suggestion from microseismicity for an abrupt locked-to-sliding transition, as, for example, signifies its location in the Himalaya. An alternative measure of future potential seismic energy release is to identify the locus and rate of present-day strain contraction. To this end, Venezuelan, Colombian and US (CU and UNAVCO) investigators are installing an array of more than a dozen continuous operating GPS sites in the region. Studies of tsunami deposits on the Dutch Antilles suggest that the provenance of paleotsunami responsible for moving 10-100 ton blocks of coral onshore in the past two millennia has been from the east (Sheffers, 2002), and not from the north or south as we might expect from a NW Venezuelan earthquake. The existence of precariously balanced rocks in the region provides an alternative constraint on the occurrence of large local accelerations. The survival of at least four precariously balanced megablocks on the island of Aruba suggests that horizontal accelerations here have not exceeded 1 g for the past several millennia, but refined numerical estimates of potential shaking intensity consistent with their survival have yet to be completed. Accelerations exceeded 2.5 g in the Tohuko 2011 earthquake but above the Mexican subduction zone, accelerations have typically not exceeded 0.5 g in recent Mw~7.5 earthquakes, and hence the existence of these blocks may not exclude the historical occurrence of damaging earthquakes. A broader search for surviving strong-motion indicators in Colombia and Venezuela is planned during the installation of the GPS array.

  10. Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela

    PubMed Central

    Milazzo, Mary L.; Cajimat, Maria N.B.; Duno, Gloria; Duno, Freddy; Utrera, Antonio

    2011-01-01

    Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston’s cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston’s cotton rats were infected with PIRV. The results of analyses of field and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRV-infected Alston’s cotton rats may transmit the viruses to humans. PMID:22172205

  11. Mineral content of the honey produced in Zulia state, Venezuela.

    PubMed

    Sulbarán de Ferrer, Betzabé; Ojeda de Rodríguez, Graciela; Peña, Jorge; Martínez, Janeth; Morán, María

    2004-09-01

    The mineral content of the honey produced in five zones of the Zulia state, Venezuela, during dry and rainy seasons was determined. The analyzed elements were: sodium, potassium (by emission spectroscopy), calcium, magnesium, copper, iron, manganese (by atomic absorption spectroscopy), phosphorus (phosphate ions, by colorimetric method), and ash content of raw honey samples directly collected from different beekeepers. The mean values for Na, K, Ca, Mg, Cu, Fe, Mn, and P were 353+84; 1774+138; 237+66; 52+24; 0.76+0.43; 13.5+10.23; 0.92+0.42 and 1642+323 mg/kg respectively. The mean ash content was 0.431+0.15%. Potassium was the most abundant of the elements determined. This results confirm that Zulian honey can be considered a good source of minerals. PMID:15807212

  12. Epidemiology and Disease Burden of Pediatric Dengue in Venezuela.

    PubMed

    Torres, Jaime R; Echezuría, Luís; Fernández, Mariano; Rísquez, Alejandro

    2015-12-01

    Dengue is a mosquito-borne viral disease that has evolved from a sporadic infection to a major public health problem in the Americas, Southeast Asia and the western Pacific, and Africa [ 1- 4]. Its incidence has increased 30-fold over the past 50 years, and although the true disease burden is not well known, the annual incidence in some areas of the Americas may reach 5%-10% of all children when underreporting is considered [ 1]. We recently analyzed the disease burden of dengue in Venezuela, and we found an overall decline in case numbers and mortality over the period of 1950-2011 [ 5]. However, there were increases in case number and mortality during epidemic years, especially among children [ 5]. In this report, we focus on the most recent period of data, from 2000 to 2011, comparing pediatric and adult case numbers and mortality. PMID:26407287

  13. Coal in Colombia and Venezuela: Production, transportation and export logistics

    SciTech Connect

    Thompson, D.

    1998-12-31

    The coal seams uplifted by the Perija and Sierra Nevada de Santa marta Mountains along the border of Colombia and Venezuela are high quality reserves with low mining ratios that are in close proximity to the coast. Since the late 70`s and early 80`s, various mining developments have increased the production of these reserves to its current level of 37 million tons per year. Most of the production is shipped to European and to North and South American markets. Further exploitation of these reserves will require significant investments in mine development, inland transportation, and port facilities. This paper will summarize the current status of the Colombian and Venezuelan coal industry, as well as the potential and challenges for increased production and exportation.

  14. Multidata remote sensing approach to regional geologic mapping in Venezuela

    SciTech Connect

    Baker, R.N.

    1996-08-01

    Remote Sensing played an important role in evaluating the exploration potential of selected lease blocks in Venezuela. Data sets used ranged from regional Landsat and airborne radar (SLAR) surveys to high-quality cloud-free air photos for local but largely inaccessible terrains. The resulting data base provided a framework for the conventional analyses of surface and subsurface information available to the project team. (1) Regional surface geology and major structural elements were interpreted from Landsat MSS imagery supplemented by TM and a regional 1:250,000 airborne radar (SLAR) survey. Evidence of dextral offset, en echelon folds and major thoroughgoing faults suggest a regional transpressional system modified by local extension and readjustment between small-scale crustal blocks. Surface expression of the major structural elements diminishes to the east, but can often be extended beneath the coastal plain by drainage anomalies and subtle geomorphic trends. (2) Environmental conditions were mapped using the high resolution airborne radar images which were used to relate vegetation types to surface texture and elevation; wetlands, outcrop and cultural features to image brightness. Additional work using multispectral TM or SPOT imagery is planned to more accurately define environmental conditions and provide a baseline for monitoring future trends. (3) Offshore oil seeps were detected using ERS-1 satellite radar (SAR) and known seeps in the Gulf of Paria as analogs. While partially successful, natural surfactants, wind shadow and a surprising variety of other phenomena created {open_quotes}false alarms{close_quotes} which required other supporting data and field sampling to verify the results. Key elements of the remote sensing analyses will be incorporated into a comprehensive geographic information (GIS) which will eventually include all of Venezuela.

  15. Venezuela 2000 restructures its electric power sector to ensure competitiveness

    SciTech Connect

    Alvarez, C.E.

    1999-11-01

    Today, it is well known that the countries that are best equipped to develop their production are not those with the most natural resources but those who have the best trained people, most technical resources and that base their development on competitiveness. The State model is, definitely, not one that offers the greatest advantages, and Venezuela is an example of this. Even when, thanks to the economic boom the country enjoyed in the 70s and 80s, it was able to cost the investments required to develop its infrastructure and to prepare a first class human contingent, over the long term, competition was discouraged and waste encouraged. The result was that, even when Venezuela had vast economic resources compared to its relatively small population, it was not able to become the exception to the rule and succeed in applying this model--now considered obsolete in many countries--indefinitely. Another model based on private ownership has begun to take its place, one that has made it possible to cost the increasingly large investments required, involves opening up these sectors to private capital, and uses the phenomenon of globalization--a major driving force behind competition and one that has wrought considerable change in all corners of the increasingly smaller planet. This paper describes the steps that different sectors in the country have been taking to implement this new model in the electric power sector, such as developing draft legislation for regulating the Sector, very shortly to culminate in the passing of an electric power law by Congress; opening up the Sector to private investors (privatization); dividing the electric power industry into four business units (generation, transmission, distribution and marketing); the electric power market; and other innovations currently being implemented.

  16. The importance of trenching in paleoseismic studies in Venezuela: brief historical summary

    NASA Astrophysics Data System (ADS)

    Murria, J.

    2009-04-01

    Paleoseismic studies have proved to be a powerful tool in seismic hazards assessment by he contributing to asses the seismogenic potential of a given fault by expanding the time window o seismic activity beyond the limits of historical and instrumental seismicity. Trenching has been an essential tool for paleoseismic studies in Venezuela. The first paleoseismic trenching project in Venezuela goes back to 1968 when Compania Shell de Venezuela retained the services of Woodward Clyde and Associates,(WCA), USA to asses the seismic integrity of the earthen dikes of Costa Oriental of Lake Maracaibo Protection System (COLM) in western Venezuela. The study was carried out under the general coordination of this author. An important part of this project included a seismology and seismic geology study under the direction of Geologist L.S. Cluff. This was the first ever study undertaken in Venezuela and included two excavations across the Oca Fault north of the city of Maracaibo. After several years of inactivity, FUNVISIS (The Venezuelan Foundation for Seismological Research) carried out in 1980 a seismic hazard (SHA) for the Uribante Caparo Hydroelectric Project southwest Venezuela. In 1989, MARAVEN, an operating company of PETROLE0S DE VENEUELA S.A. (PDVSA) undertook the project of a products pipeline form Maracaibo to El Vigia, south of Lake Maracaibo. Again, FUNVISIS was contracted to carry out a SHA, which included the digging of 5 trenches, which were supplemented with five more trenches for the COLM project. Trenching activity contined in Venezuela in the framework of SHA project, under the direction of Dr. Audemard. In 2001 Venezuelan trenching experience was exported to the neighboring Colombia as e Dr. Audemard t undertook a palaoseismicity project which included the digging of five trenches. In conclusion, paleoseismicty studies have given us the possibility of extending the scope of both instrumental and historical seismicity by some 10,000 years, trenching has proved for paleoseismic studies to be a valuable to.

  17. Modelo Crosscultural de Pasantias para Lideres de la Educacion: Cooperacion entre Estados Unidos y Venezuela (Designing an Effective School Administrator Internship Program: United States and Venezuela Cooperation).

    ERIC Educational Resources Information Center

    Serafin, Ana Gil; Thompson, Eugene W.

    A model was developed of an internship program designed to give valuable cross-cultural experience to school administrators in training at universities in the United States and Venezuela. A naturalistic approach was used to develop the model. Leading school administrators and educational leadership theorists in both countries were interviewed by…

  18. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species.

    PubMed

    Gutiérrez, Manuel Caballer; Ortea, Jesús; Rivero, Nelsy; Tucker, Gabriela Carias; Malaquias, Manuel António E; Narciso, Samuel

    2015-01-01

    The Caribbean waters of Venezuela are composed by a large variety of habitats, with over 2800 km of coastline, islands, and islets. This area is a transitional zone between two main biogeographic provinces, the Caribbean and the Brazilian, separated by the fresh water outflows of the Orinoco and Amazon rivers, and is therefore expected to be an area of high species diversity. However, concerning the study of molluscs, Venezuela is probably the poorest known region in the Caribbean. The best compilation of opisthobranch species known in Venezuela was produced almost a decade ago, mentioning the occurrence of 57 species, plus seven determined only to genus level. In this work, 134 species are reported for Venezuela (71 are illustrated), representing about 40 % of the entire diversity of opisthobranchs known in the Caribbean. Among the species occurring in Venezuela, 49 have here the southern limit of their distribution range and only one the northern limit. Forty-six species are recorded for the first time to the country and one is a new record for the Caribbean Sea, namely Placida cremoniana. In addition, the distribution and ecology of the species are given based in literature and new data. PMID:26624440

  19. Structural Model of the Tucupita Field, Eastern Venezuela Basin

    NASA Astrophysics Data System (ADS)

    Arteaga, L. A.

    2013-05-01

    The Tucupita Field has an area of 73,51 Km2, is located between the states of Monagas and Delta Amacuro, geologically is located at the greater Temblador area in the Eastern Venezuela Basin, where the Oficina Formation's sands represent the main hydrocarbons reservoirs. From the results of the seismic reprocessing realized by Fusion Petroleum Technologies, Inc., the structural model of this field was done as initial step to the geocellular model of the Oficina-40 Reservoir, which was defined as a Faulted Relay Ramp, where the normal faults are dominant with NE-SW orientation Introduction The Tucupita Field is a mature oilfield at the greater Temblador area, however most of the wells were completed in the upper sands, therefore the main study is focused in the geological characterization of the Oficina-40 Reservoir's lower sands, starting by the structural model Previous Studies 1. Proyecto Tucupita 3D The seismic data of the Tucupita Field were adquired in 1996 by Western Atlas of Venezuela for the Benton Vinccler Company. The UTM coordinates of the wells used in this project, have been taken to make this geological model 2. Soporte Geofísico Integrado The seismic project Tucupita was processed by Fusion Petroleum Technologies Inc., in Houston and consisted of reprocessing and pre-stack migration in time (PSTM) and pre-stack migration in depth (PSDM), this data belong to the Petrodelta Company Based on the regional stratigraphy, were validated the "picks" to make the structural sections to support research with hard data. After, it proceeded to interpret the structural style of the field from the seismic amplitude cube. Then, it was done the faults modelling and the stratigraphic horizons to carry out the geocellular model Three structural sections were realized, which was interpreted like a faulted monocline, whose peak is located southward, where justly the wells are located. The contact oil-water was interpreted to -5648'. Echelon faults were interpreted in a structure of the Faulted Relay Ramp (Figure 1), defined by two normal faults with orientation NE-SW, including the main fault of Tucupita Field Conclusions 1. The development of this structural model led to geological characterization of the Oficina-40 Reservoir, integrating this interpretation in a geocellular model to calculate the STOIIP.The Tucupita Field is characterized structurally as a Faulted Relay Ramp References 1. Fusion Petroleum Technologies, Inc. 2009. PROYECTO TUCUPITA SOPORTE GEOFÍSICO INTEGRADO; Figure 1. Faulted Relay Ramp, Tucupita Field

  20. Confronting Health Disparities: Latin American Social Medicine in Venezuela

    PubMed Central

    Mantini-Briggs, Clara

    2009-01-01

    Objectives. We explored the emergence and effectiveness of Venezuela's Misión Barrio Adentro, “Inside the Neighborhood Mission,” a program designed to improve access to health care among underserved residents of the country, hoping to draw lessons to apply to future attempts to address acute health disparities. Methods. We conducted our study in 3 capital-region neighborhoods, 2 small cities, and 2 rural areas, combining systematic observations with interviews of 221 residents, 41 health professionals, and 28 government officials. We surveyed 177 female and 91 male heads of household. Results. Interviews suggested that Misión Barrio Adentro emerged from creative interactions between policymakers, clinicians, community workers, and residents, adopting flexible, problem-solving strategies. In addition, data indicated that egalitarian physician–patient relationships and the direct involvement of local health committees overcame distrust and generated popular support for the program. Media and opposition antagonism complicated physicians’ lives and clinical practices but heightened the program's visibility. Conclusions. Top-down and bottom-up efforts are less effective than “horizontal” collaborations between professionals and residents in underserved communities. Direct, local involvement can generate creative and dynamic efforts to address acute health disparities in these areas. PMID:19150916

  1. Structural style on southern flank of Merida Andes, Venezuela

    SciTech Connect

    Urbina, C.; Cornelio, A. )

    1993-02-01

    The Merida Andes exhibit the most complex tectonics in western Venezuela. By studying the different ages and regional distribution of rocks, we can describe some tectonic features which are of interest to oil exploration in this area. Vertical basement movements accompanied extensional tectonics from pre-Cambrian until Eocene times. For this time interval, we reconstructed diverse normal fault systems and associated subsidence. From Eocene time onwards, compressional tectonics gave origin to anticlines and reverse, thrust and back-thrust faults. Neo-tectonic movements have modified existing structures by dislocation along transcurrent fault systems. Geochemical analyses have determined the presence of hydrocarbon source rocks equivalent to the a Luna Formation of the Maracaibo Basin; seismic, surface and subsurface data prove the existence of excellent seals in the Eocene Paguey Shale. The principal problem is to determine the timing of hydrocarbon migration with respect to the timing of trap formation. It is highly probable that the sapropelic strata of the Navay Formation, equivalent to the La Luna Formation, is presently expelling hydrocarbons to traps in the Barinas Basin, under presently existing temperature-pressure conditions.

  2. Gran Sabana fires (SE Venezuela): a paleoecological perspective

    NASA Astrophysics Data System (ADS)

    Montoya, Encarni; Rull, Valentí

    2011-11-01

    Fires are among the most important risks for tropical ecosystems in a future climatic change scenario. Recently, paleoecological research has been addressed to discern the role played by fire in neotropical landscapes. However, given the magnitude of the Neotropics, many studies are relegated to infer just local trends. Here we present the compilation of the paleo-fire records developed until now in the southern Gran Sabana (SE Venezuela) with the aim to describe the fire history as well as to infer the possible forcing factors implied. In this sense, southern Gran Sabana has been under fire perturbation since the Lateglacial, with the concomitant effects upon vegetation, and persisted during the Holocene. Around 2000 cal yr BP onwards, the fire activity highly increased promoting the expansion of pre-existing savannas, the decrease of forests and the appearance and establishment of Mauritia palm swamps. The continuous fire incidence registered for several thousands of years has likely promoted the supremacy of treeless savannas upon other vegetation types and the degradation to secondary landscapes. Based on the available evidence, the anthropogenic nature of this high fire activity has been postulated. If so, it could be hypothesized that the timing arrival of Pemón, the present-day indigenous culture in the Gran Sabana, would be ca 2000 cal yr BP onwards, rather than the last centuries, as it has been formerly assumed. The implications of these ancient practices in the area are also discussed for present Gran Sabana landscapes sustainability and future conservation strategies.

  3. Intestinal Parasitic Infections among Pregnant Women in Venezuela

    PubMed Central

    Rodríguez-Morales, Alfonso J.; Barbella, Rosa A.; Case, Cynthia; Arria, Melissa; Ravelo, Marisela; Perez, Henry; Urdaneta, Oscar; Gervasio, Gloria; Rubio, Nestor; Maldonado, Andrea; Aguilera, Ymora; Viloria, Anna; Blanco, Juan J.; Colina, Magdary; Hernández, Elizabeth; Araujo, Elianet; Cabaniel, Gilberto; Benitez, Jesús; Rifakis, Pedro

    2006-01-01

    Introduction. Intestinal parasitic infections, especially due to helminths, increase anemia in pregnant women. The results of this are low pregnancy weight gain and IUGR, followed by LBW, with its associated greater risks of infection and higher perinatal mortality rates. For these reasons, in the setting of no large previous studies in Venezuela about this problem, a national multicentric study was conducted. Methods. Pregnant women from nine states were studied, a prenatal evaluation with a coproparasitological study. Univariated and multivariated analyses were made to determine risk factors for intestinal parasitosis and related anemia. Results. During 19 months, 1038 pregnant women were included and evaluated. Intestinal parasitosis was evidenced in 73.9%: A lumbricoides 57.0%, T trichiura 36.0%, G lamblia 14.1%, E hystolitica 12.0%, N americanus 8.1%, E vermicularis 6.3%, S stercoralis 3.3%. Relative risk for anemia in those women with intestinal parasitosis was 2.56 (P < .01). Discussion. Intestinal parasitoses could be associated with conditions for development of anemia at pregnancy. These features reflect the need of routine coproparasitological study among pregnant women in rural and endemic zones for intestinal parasites. Further therapeutic and prophylactic protocols are needed. Additional research on pregnant intestinal parasitic infection impact on newborn health is also considered. PMID:17093349

  4. Caribbean basin framework, 4: Maracaibo basin, northwestern Venezuela

    SciTech Connect

    Lugo, J. )

    1991-03-01

    The Maracaibo basin is presently located in a topographic depression on the Maracaibo block, a triangular, fault-bounded block within the Caribbean-South America plate boundary of northwestern Venezuela. Intense oil exploration over the last 50 years has produced a large amount of seismic and well data that can be used to constrain four Jurassic to Recent tectonic and depositional events that affected the region: (1). Late Jurassic rift phase and subsidence along normal faults striking north-northeast across the floor of the basin; (2) Cretaceous to early Eocene subsidence recorded by shallow to deep marine carbonate and clastic rocks that thicken from south to north and completely cover Permian rocks of the Merida arch; (3) Eocene folding, thrusting, and initial reactivation of Jurassic normal faults as convergent strike-slip and reverse faults. Eocene clastic sediments are thickest in a narrow northwest-trending foredeep on the northeastern margin of the basin; (4) Late Miocene to Recent northwest-southeast convergence is marked by continued reactivation of Jurassic normal faults as reverse and left-lateral strike-slip faults, uplift of mountain ranges bordering the basin, and deposition of up to 10 km of clastic sediment.

  5. Late quaternary environmental history of Lake Valencia, Venezuela

    USGS Publications Warehouse

    Platt, Bradbury J.; Leyden, B.; Salgado-Labouriau, M.; Lewis, W.M., Jr.; Schubert, C.; Binford, M.W.; Frey, D.G.; Whitehead, D.R.; Weibezahn, F.H.

    1981-01-01

    Chemical, paleontological, and mineralogical analyses of a 7.5-meter core from the middle of Lake Valencia, Venezuela, have provided information on the paleoclimatic history of this low-elevation, low-latitude site for the last 13,000 years. The data show that dry climates existed in this region from 13,000 years before present (B.P.) until about 10,000 years B.P. The Lake Valencia Basin was occupied by intermittent saline marshes at that time. About 10,000 years B.P., a permanent lake of fluctuating salinity formed and arboreal plant communities replaced the earlier dominant xeric herbaceous vegetation and marsh plants. By 8500 years B.P., Lake Valencia reached moderate to low salinities and discharged water; the modern vegetation became established at that time. After 8500 years B.P., the lake twice ceased discharging as a result of reduced watershed moisture. The second of these drying episodes is still in progress and has been aggravated by human activities in the watershed. Copyright ?? 1981 AAAS.

  6. Sedimentary sequence evolution in a Foredeep basin: Eastern Venezuela

    SciTech Connect

    Bejarano, C.; Funes, D.; Sarzalho, S.; Audemard, F.; Flores, G.

    1996-08-01

    Well log-seismic sequence stratigraphy analysis in the Eastern Venezuela Foreland Basin leads to study of the evolution of sedimentary sequences onto the Cretaceous-Paleocene passive margin. This basin comprises two different foredeep sub-basins: The Guarico subbasin to the west, older, and the Maturin sub-basin to the east, younger. A foredeep switching between these two sub-basins is observed at 12.5 m.y. Seismic interpretation and well log sections across the study area show sedimentary sequences with transgressive sands and coastal onlaps to the east-southeast for the Guarico sub-basin, as well as truncations below the switching sequence (12.5 m.y.), and the Maturin sub-basin shows apparent coastal onlaps to the west-northwest, as well as a marine onlap (deeper water) in the west, where it starts to establish. Sequence stratigraphy analysis of these sequences with well logs allowed the study of the evolution of stratigraphic section from Paleocene to middle Miocene (68.0-12.0 m.y.). On the basis of well log patterns, the sequences were divided in regressive-transgressive-regressive sedimentary cycles caused by changes in relative sea level. Facies distributions were analyzed and the sequences were divided into simple sequences or sub- sequences of a greater frequencies than third order depositional sequences.

  7. New Insights into Chloramphenicol Biosynthesis in Streptomyces venezuelae ATCC 10712

    PubMed Central

    Fernández-Martínez, Lorena T.; Borsetto, Chiara; Gomez-Escribano, Juan Pablo; Bibb, Maureen J.; Al-Bassam, Mahmoud M.; Chandra, Govind

    2014-01-01

    Comparative genome analysis revealed seven uncharacterized genes, sven0909 to sven0915, adjacent to the previously identified chloramphenicol biosynthetic gene cluster (sven0916–sven0928) of Streptomyces venezuelae strain ATCC 10712 that was absent in a closely related Streptomyces strain that does not produce chloramphenicol. Transcriptional analysis suggested that three of these genes might be involved in chloramphenicol production, a prediction confirmed by the construction of deletion mutants. These three genes encode a cluster-associated transcriptional activator (Sven0913), a phosphopantetheinyl transferase (Sven0914), and a Na+/H+ antiporter (Sven0915). Bioinformatic analysis also revealed the presence of a previously undetected gene, sven0925, embedded within the chloramphenicol biosynthetic gene cluster that appears to encode an acyl carrier protein, bringing the number of new genes likely to be involved in chloramphenicol production to four. Microarray experiments and synteny comparisons also suggest that sven0929 is part of the biosynthetic gene cluster. This has allowed us to propose an updated and revised version of the chloramphenicol biosynthetic pathway. PMID:25267678

  8. First Report of Cowpea Mild Mottle Carlavirus on Yardlong Bean (Vigna unguiculata subsp. sesquipedalis) in Venezuela

    PubMed Central

    Brito, Miriam; Fernández-Rodríguez, Thaly; Garrido, Mario José; Mejías, Alexander; Romano, Mirtha; Marys, Edgloris

    2012-01-01

    Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained amplicons showed 84%–74% similarity to corresponding sequences of Cowpea mild mottle virus (CPMMV) isolates deposited in the GenBank database. This is the first report of CPMMV in Venezuela and is thought to be the first report of CPMMV infecting yardlong bean. PMID:23242372

  9. A modern regional geological analysis of Venezuela - lessons from a major new world oil province on exploration in mature areas

    SciTech Connect

    Daly, M. ); Audemard, F. ); Valdes, G. )

    1993-09-01

    Venezuela has produced some 44 billion bbl of oil since the early part of the century. As such, it represents one of the world's major oil producers and a mature petroleum province. However, major tracts of Venezuela's sedimentary basins remain underexplored and large discoveries are still being made in new and old reservoir systems. A regional geological analysis of Venezuela, focusing on basin evolution and sequence stratigraphy and incorporating data from the three national oil companies, is presented. The analysis presents a regionally consistent tectonostratigraphic model capable of explaining the evolution of the Mesozoic and Cenozoic basins of Venezuela and placing the major reservoir facies in their regional tectonic and sequence stratigraphic context. Four regional cross sections describe the stratigraphic and structural model. The model recognizes a Jurassic rifting event and inversion, succeeded by an Early Cretaceous passive margin. In western Venezuela, the Early Cretaceous passive subsidence is enhanced locally by extension related to the Colombian active margin. Venezuela experienced a major change in the Campanian with the initial collision of the Caribbean arc, recorded by foreland structuring and widespread stratigraphic changes. From the Campanian onward, the tectonostratigraphic evolution can be modeled in terms of a progressive southeast-directed arc-continent collision and the migration of the associated foredeep and rift basins. Within the tectonic framework, the major sequence stratigraphic units are identified and the reservoir distribution interpreted. This model provides a strong predictive tool to extrapolate reservoir systems into Venezuela's underexplored areas and to readdress its traditional areas.

  10. STSHV a teleinformatic system for historic seismology in Venezuela

    NASA Astrophysics Data System (ADS)

    Choy, J. E.; Palme, C.; Altez, R.; Aranguren, R.; Guada, C.; Silva, J.

    2013-05-01

    From 1997 on, when the first "Jornadas Venezolanas de Sismicidad Historica" took place, a big interest awoke in Venezuela to organize the available information related to historic earthquakes. At that moment only existed one published historic earthquake catalogue, that from Centeno Grau published the first time in 1949. That catalogue had no references about the sources of information. Other catalogues existed but they were internal reports for the petroleum companies and therefore difficult to access. In 2000 Grases et al reedited the Centeno-Grau catalogue, it ended up in a new, very complete catalogue with all the sources well referenced and updated. The next step to organize historic seismicity data was, from 2004 to 2008, the creation of the STSHV (Sistema de teleinformacion de Sismologia Historica Venezolana, http://sismicidad.hacer.ula.ve ). The idea was to bring together all information about destructive historic earthquakes in Venezuela in one place in the internet so it could be accessed easily by a widespread public. There are two ways to access the system. The first one, selecting an earthquake or a list of earthquakes, and the second one, selecting an information source or a list of sources. For each earthquake there is a summary of general information and additional materials: a list with the source parameters published by different authors, a list with intensities assessed by different authors, a list of information sources, a short text summarizing the historic situation at the time of the earthquake and a list of pictures if available. There are searching facilities for the seismic events and dynamic maps can be created. The information sources are classified in: books, handwritten documents, transcription of handwritten documents, documents published in books, journals and congress memories, newspapers, seismologic catalogues and electronic sources. There are facilities to find specific documents or lists of documents with common characteristics. For each document general information is displayed together with an extract of the information relating to the earthquake. If the complete document was available and no problem with the publishers rights a pdf copy of the document was included. We found this system extremely useful for studying historic earthquakes, as one can access immediately previous research works about an earthquake and it allows to check easily the historic information and so to validate the intensity data. So far, the intensity data have not been completed for earthquakes after 2000. This information would be important for improving calibration of intensity - magnitude calibrations of historic events, and is a work in progress. On the other hand, it is important to mention that "El Catálogo Sismológico Venezolano del siglo XX" (The Seismological Venezuelan Catalog), published in 2012, updates seismic information up to 2007, and that the STSHV was one of its primary sources of information.

  11. [Descriptive study of 43 nutritional education programs in Venezuela].

    PubMed

    Dehollaín, P L; Pérez Schael, I; Sfeir, L

    1983-06-01

    This study aimed to determine the existing resources and specific characteristics of non-formal nutrition education programs in Venezuela. Of the 174 institutions initially contacted, 43 were involved in these activities-22 official and 21 private institutions. The bulk of the programs fell under the official health sector and the private food industry. While objectives of the former were to motivate and educate the audience, the latter's goal was basically commercial. Forty-three per cent of the program content dealt with basic nutrition concepts; only 19% of programs included information on breast feeding, and maternal and child nutrition. There is a significantly greater use of interpersonal communication (65%) as compared to mass media (35%), irrespective of the type of institution. In the majority of programs, the nutritionist-dietitians and medical doctors carry out their activities, primarily oriented towards homemakers and school-age children. The official health sector gears its programs toward the poor, while the main interest of private industry are the middle and upper class communities. A total of 46% of the official programs and 55% of the private institutions do not include an evaluation component. It is concluded that the nutrition education programs in the country appear to follow traditional concepts as far as objectives, program content, media and target groups are concerned. This could have contributed to the apparent lack of impact of non-formal nutrition education in the country; thus the re-planning of existing programs, is suggested. This should be based on well-defined and measurable objectives: include messages geared toward the practical solution of specific nutrition problems, and the use of combined techniques of social communication with as much participation of the community as possible, not only in program implementation but also in its conception and planning. PMID:6673677

  12. A 75 ka Stalagmite Paleoclimate Record from Northern Venezuela

    NASA Astrophysics Data System (ADS)

    Retrum, J. B.; Gonzalez, L. A.; Edwards, R.; Tincher, S. M.; Cheng, H.; Urbani, F.

    2011-12-01

    A stalagmite collected from Cueva Zarraga in the northern Venezuelan Andes was analyzed to determine local paleoclimatic history and help examine climate change in the Caribbean. Ages were determined by U/Th disequilibrium and the stalagmite shows a nearly complete record for ~ 75 ka. Two significant periods of non-deposition have been identified. The first period ranges between the Last Glacial Maximum at 19,820 ± 149 cal yr BP and a brief resumption of stalagmite growth at 15,409 ± 747 cal yr BP, likely representing the Bølling-Allerød interstadial. After the brief period of deposition, growth does not resume unil the Holocene at 10,408 ± 78 cal yr BP. Carbon and oxygen isotopes show a major depletion shift from the last glacial period to the Holocene, suggesting warmer and wetter conditions during the Holocene. The oxygen isotope depletion shift is also seen in the Cariaco Basin foraminifera record off the northern coast of Venezuela. While tempting to attribute ?13C depletion to decrease of the C4 plant contribution, there is no evidence that the area experience major vegetation changes. We attribute the ?13C depletion to enhanced recycling of soil CO2 resulting from canopy effects. Today, Cueva Zarraga is at the northern extent of the Inter-Tropical Convergence Zone (ITCZ). The cooler and drier conditions of the last glacial period suggest a southern displacement of the ITCZ. The close proximity of Cueva Zarraga to Cariaco Basin may allow for a high resolution tropical terrestrial and oceanic climatic response comparison.

  13. Lithospheric scale model of Merida Andes, Venezuela (GIAME Project)

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Orihuela, N. D.; Klarica, S.; Gil, E.; Levander, A.; Audemard, F. A.; Mazuera, F.; Avila, J.

    2013-05-01

    Merida Andes (MA) is one of the most important orogenic belt in Venezuela and represents the northern culmination of South America Andes. During the last 60 years, several models have been proposed to explain the shallow and deep structure, using different geological, geophysical, seismological, geochemical and petrologic concepts; nevertheless, most of them have applied local observation windows, and do not represent the major structure of MA. Therefore, a multidisciplinary research group, coordinated by FUNVISIS, in close cooperation with UCV, ULA and PDVSA, is proposed in order to get the outlined goals in the project entitled GIAME ("Geociencia Integral de los Andes de MErida") was established, which aims to generate a lithospheric scale model and the development of a temporal dynamic model for the MA. As a base for lithospheric investigations of the Merida Andes, we are proposing three wide angle seismic profiles across the orogen on three representative sites, in order to determine the inner structure and its relation with the orogen's gravimetric root. To the date, there are no seismic studies at lithospheric scale which cross MA. The wide angle seismic will be complemented with the re-processing and re-interpretation of existing reflection seismic data, which will allow to establish a relationship between MA and its associated flexural basins (Maracaibo and Barinas-Apure basins). Depending on the results of the VENCORP Project (VENezuelan COntinental Reflection Profiling), which might show some reliable results about crustal features and Moho reflectors along three long seismic profiles at Caribbean Moutain system, a reflection seismic profile across the central portion of MA is proposed. Additional tasks, consisting in MA quaternary deformation studies, using research methods like neotectonics and paleoseismology, georadar, numerical modeling, cinematic GPS, SAR interferometry, thermocronology, detailed studies on regional geology, flexural modeling, gravity modeling, among others, will be carried out. We expect this project is going to help to solve many of the doubts regarding the origin, evolution and structural configuration of the Merida Andes.

  14. Neogene history of the Carapita Formation, Eastern Venezuela basin

    NASA Astrophysics Data System (ADS)

    Sanchez Zambrano, Dennis Alberto

    The planktonic and benthic foraminifera from the lower to middle Miocene shales of the Carapita Formation of Eastern Venezuela in three exploration wells and one outcrop section are analyzed with the objectives of establishing a precise biostratigraphy of the formation and its bathymetric history. Comparison with the well-preserved microfaunas of the correlative Cipero Formation of Trinidad made possible the achievement of these objectives. The formation, up to 4500 to 6000 m thick in outcrops, extends from northeastern Anzoategui and North of Monagas States to the Gulf of Paria and is both an important oil reservoir towards the east and the main seal rock for the Oligocene reservoir in the north of Monagas State. In the area studied the Carapita Formation spans lower to lower middle Miocene Zones N6/M3 to N9/M6; its upper part is unconstrained as only rare long ranging early Miocene to early Pliocene planktonic foraminifera occur above the Orbulina datum. Unexpectedly, we found that the four lower to middle Miocene sections are highly discontinuous, with hiastuses as long as 4 Myr. Based on the abundance patterns of sixty-nine species of benthic foraminifera and analysis of morphotype abundance following the methodology of Corliss and Chen (1988) and Corliss and Fois (1993), we show that the Carapita Formation was deposited at outer neritic to middle bathyal depths (?200--1000 m), whereas the Cipero Formation was deposited at middle to lower bathyal depths (?600--2000 m). Importantly, the bathymetric changes are associated with unconformities in all sections, strongly suggesting that both (shallowing and associated unconformities) were tectonically induced.

  15. LA BIOÉTICA COMO QUEHACER FILOSÓFICO

    PubMed Central

    Ferrer, Jorge José

    2009-01-01

    El artículo examina el estatuto epistemológico de la bioética como disciplina académica. El autor sostiene que el estatuto epistemológico de un discurso lo determina la pregunta fundamental que se plantea y la respuesta que se busca, focos integradores del discurso. En el caso de la bioética, la pregunta fundamental es de índole moral. La bioética es pues una disciplina ética que tiene su hogar epistemológico en la filosofía. El autor también defiende el concepto de “éticas aplicadas”. Sugiere finalmente que el método de la bioética, sobre todo la que se hace desde nuestras latitudes, debería adoptar el círculo hermenéutico como metodología para su filosofar. PMID:20463860

  16. Adapting EVIAVE methodology as a planning and decision-making tool in Venezuela.

    PubMed

    Zamorano, M; Paolini, A; Ramos, A; Rodríguez, M L

    2009-12-30

    Landfills in Venezuela have serious problems regarding their location, design and operation. In fact, basic waste disposal is one of the main weaknesses of the municipal waste management in this country. The Venezuelan Ministry of Environment and Renewable Resources has studied and identified the negative impacts of operating landfills, but no program has been implemented to determine the cause-effect relation of these impacts or to design strategies to counteract with the serious environmental and health risks generated. This paper describes how EVIAVE methodology can be successfully used for landfill diagnosis, and shows how this type of landfill diagnosis was applied in Venezuela. For our research study, we carried out both a quantitative and qualitative evaluation of the environmental problems generated by 22 landfills in Venezuela. Our study was based on the following environmental indexes: Landfill Environment, Environmental Risk, Environmental Value, and Probability of Contamination. For the purposes of our study, it was first necessary to adapt EVIAVE to the legal system and social context in Venezuela. The results obtained confirmed the applicability of this methodology to Venezuelan landfills. EVIAVE was found to be an effective planning tool that provided crucial information for the development of action plans, which would improve landfill operation, and help make decisions pertaining to their closure, sealing and eventual recovery. PMID:19699030

  17. Early Sexual Maturity Among Pume Foragers of Venezuela: Fitness Implications of Teen Motherhood

    E-print Network

    Kramer, Karen L.

    Early Sexual Maturity Among Pume´ Foragers of Venezuela: Fitness Implications of Teen Motherhood their late teens. Am J Phys Anthropol 136:338­350, 2008. VVC 2008 Wiley-Liss, Inc. Age at first birth is tied biology literature on teen pregnancy, objectives are to first to describe these patterns and then discuss

  18. Lobomycosis in Man and Lobomycosis-like Disease in Bottlenose Dolphin, Venezuela

    PubMed Central

    Bermudez, Luis; Van Bressem, Marie-Françoise; Reyes-Jaimes, Oscar; Sayegh, Alejandro J.

    2009-01-01

    We report 1 case of lobomycosis caused by Lacazia loboi in a fisherman and 1 case of lobomycosis-like disease in a bottlenose dolphin (Tursiops truncatus) along the coast of Venezuela. These findings suggest that the marine environment is a likely habitat for L. loboi and a reservoir for infection. PMID:19751598

  19. A new species of the genus Alienates Barber (Hemiptera: Heteroptera: Enicocephalidae: Alienatinae) from Venezuela.

    PubMed

    Ba?a?, Petr; Štys, Pavel; Kolesnichenko, Yuliya

    2015-01-01

    New species Alienates thomasi sp. nov. Ba?a? & Štys is described from Venezuela based on a single female. It is the first species recorded from South America, and is illustrated and compared with other Caribbean and Central American Alienates species. PMID:26623865

  20. The Effect of Wage Compression and Alternative Labor Market Opportunities on Teacher Quality in Venezuela

    ERIC Educational Resources Information Center

    Ortega, Daniel E.

    2010-01-01

    This paper examines the effect of teacher relative wages and teacher wage dispersion on high school graduates' preferences for teaching majors in College. This approximation to teacher quality is appropriate in a country like Venezuela as opposed to the US since the rigidity of the tertiary school system significantly limits mobility between…

  1. Five Years of Cyclotron Radioisotope Production Experiences at the First PET-CT in Venezuela

    SciTech Connect

    Colmenter, L.; Coelho, D.; Esteves, L. M.; Ruiz, N.; Morales, L.; Lugo, I.; Sajo-Bohus, L.; Liendo, J. A.; Greaves, E. D.; Barros, H.; Castillo, J.

    2007-10-26

    Five years operation of a compact cyclotron installed at PET-CT facility in Caracas, Venezuela is given. Production rate of {sup 18}F labeled FDG, operation and radiation monitoring experience are included. We conclude that {sup 18}FDG CT-PET is the most effective technique for patient diagnosis.

  2. 78 FR 44969 - Ferrosilicon From Russia and Venezuela; Institution of Antidumping Duty Investigations and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    .... Please consult the Commission's rules, as amended, 76 FR 61937 (Oct. 6, 2011) and the Commission's Handbook on Filing Procedures, 76 FR 62092 (Oct. 6, 2011), available on the Commission's Web site at http... Ferrosilicon From Russia and Venezuela; Institution of Antidumping Duty Investigations and Scheduling...

  3. Teachers' Perceived Efficacy among English as a Foreign Language Teachers in Middle Schools in Venezuela

    ERIC Educational Resources Information Center

    Chacon, C.T.

    2005-01-01

    Teachers' sense of efficacy has been shown to influence teachers' actions and student outcomes. This study explored self-efficacy beliefs among English as a Foreign Language teachers in selected schools in Venezuela. Data were collected through a survey administered to 100 teachers. The Teacher Sense of Efficacy Scale (Tschannen-Moran & Woolfolk…

  4. Education, Democracy and Social Change: Venezuela's Education Missions in Theory and Practice

    ERIC Educational Resources Information Center

    Duffy, Maura

    2015-01-01

    The "Bolivarian Revolution" in Venezuela is conceptualised as a pedagogical project that aims to develop "twenty-first century Socialism" through state-grassroots collaboration in the reorganisation of political space in order to develop participatory, democratic institutions and processes. The cornerstones of this project to…

  5. Comprehensive Education Bolivarian-Style: The Alternative School in Barrio Pueblo Nuevo, Venezuela

    ERIC Educational Resources Information Center

    Cole, Mike

    2014-01-01

    In this article, the author traces revolutionary developments in an alternative school in Barrio Pueblo Nuevo, Mérida, in the Bolivarian Republic of Venezuela, a school that caters for students between 4 and 14. He begins by recounting some fieldwork done at the school on his behalf by Edward Ellis in 2010. He goes on to discuss a video made at…

  6. Counter-Hegemonic Regionalism and Higher Education for All: Venezuela and the ALBA

    ERIC Educational Resources Information Center

    Muhr, Thomas

    2010-01-01

    This paper employs new regionalism theory and regulatory regionalism theory in its analysis and theorisation of the Bolivarian Alliance for the Peoples of Our America (ALBA) as a counter-hegemonic Latin American and Caribbean (LAC) regionalism. As (initially) the regionalisation of Venezuela's Bolivarian Revolution, ALBA is centred around the idea…

  7. 77 FR 59970 - Silicomanganese From India, Kazakhstan, and Venezuela; Institution of Five-Year Reviews...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... India, Kazakhstan, and Venezuela (73 FR 841, January 4, 2008). The Commission is now conducting second... part 201), and part 207, subparts A, D, E, and F (19 CFR part 207), as most recently amended at 74 FR... (67 FR 36149). Following the five-year reviews by Commerce and the Commission, effective November...

  8. The Bolivarian University of Venezuela: A Radical Alternative in the Global Field of Higher Education?

    ERIC Educational Resources Information Center

    Ivancheva, Mariya

    2013-01-01

    This article discusses paradoxes in the emergent global field of higher education as reflected in an alternative model of the university--the Bolivarian University of Venezuela (UBV) and the related higher education policy, Mision Sucre. With its credo in the applied social sciences, its commitment to popular pedagogy and its dependence on…

  9. 78 FR 13380 - Silicomanganese From India, Kazakhstan, and Venezuela; Scheduling of Full Five-Year Reviews...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... 751(c)(5) of the Act should proceed (78 FR 4437, January 22, 2013). A record of the Commissioners... amendments took effect on November 7, 2011. See 76 FR 61937 (Oct. 6, 2011) and the newly revised Commission's... Silicomanganese From India, Kazakhstan, and Venezuela; Scheduling of Full Five-Year Reviews Concerning...

  10. Mycobacterium tuberculosis population structure and molecular epidemiological analysis in Sucre municipality, Miranda state, Venezuela.

    PubMed

    Patiño, Margareth A; Abadía, Edgar; Solalba Gómez; Maes, Mailis; Muñoz, Mariana; Gómez, Daniela; Guzmán, Patricia; Méndez, María Victoria; Ramirez, Carmen; Mercedes, España; de Waard, Jacobus; Takiff, Howard

    2014-12-01

    Sucre municipality is a large, densely populated marginal area in the eastern part of Caracas, Venezuela that consistently has more cases of tuberculosis than other municipalities in the country. To identify the neighborhoods in the municipality with the highest prevalence of tuberculosis, and determine whether the Mycobacterium tuberculosis strain distribution in this municipality is different from that previously found in the western part of Caracas and the rest of Venezuela, we collected data on all tuberculosis cases in the municipality diagnosed in 2005-6. We performed two separate molecular epidemiological studies, spoligotyping 44 strains in a first study, and spoligotyping 131 strains, followed by MIRU-VNTR 15 on 21 clustered isolates in the second. With spoligotyping, the most common patterns were Shared International Type SIT17 (21%); SIT42 (15%); SIT93 (11%); SIT20 (7%); SIT53 (6%), a distribution similar to other parts of Venezuela, except that SIT42 and SIT20 were more common. MIRU-VNTR 15 showed that six of seven SIT17 strains examined belonged to a large cluster previously found circulating in Venezuela, but all of the SIT42 strains were related to a cluster centered in the neighborhoods of Unión and Maca, with a MIRU-VNTR pattern not previously seen in Venezuela. It appears that a large percentage of the tuberculosis in the Sucre municipality is caused by the active transmission of two strain families centered within distinct neighborhoods, one reflecting communication with the rest of the country, and the other suggesting the insular, isolated nature of some sectors. PMID:25558753

  11. Seismic microzoning projects and their implementation in Venezuela

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Cano, V.; Olbrich, F.; Vallee, M.; Morales, C.; Arreaza, A.; Mendes, K.; Klarica, S.; Alvarez Gomez, J.; Aray, J.; Vielma, J.; Pombo, A.; Diaz, J.; Grupo de trabajo

    2013-05-01

    Site effects have been recognized to play an important role in damage distribution of destructive earthquakes. These effects have been observed in Venezuela especially during the 1967 Caracas earthquake, when 4 buildings with 10 and more storeys during the Caracas 1967 earthquake collapsed, and a big number of them in the same deep sediment area have been seriously damaged. This motivated the development of studies regarding the subsurface configuration of Caracas and Barquisimeto during the last decade, with a seismic microzoning project realized in both cities from 2005 to 2009. The main results of this project were the development of design response spectra for the different microzones within the sedimentary basin, as well as estimates of landslide hazard. Implementation of the results in municipality ordinances is actually discussed with local authorities. They are aimed to address mitigation for new constructions by the application of the specific design spectra, for existing buildings via evaluation and retrofitting strategies, and for slope areas (informal, as well as formal developments) due to the identification of areas that may not be developed or require detailed studies of slope stabilities. Since then, seismic microzoning studies were started in Cumaná, Guarenas/Guatire and Lara state, and within a broader context of integrated risk management, which includes flooding, landslide and technological risks, in Mérida, Valencia, Maracay, Barcelona/Puerto La Cruz and Valle de la Pascua. The projects are coordinated by the Venezuelan Foundation for Seismological Research (FUNVISIS) in cooperation with local universities. Efforts are done to unable local researchers to apply the methodologies in other cities as Valera, Trujillo, Boconó, San Cristóbal and Tucacas. A unified seismic hazard map as input motion to these studies is actually in development. Depending on the local characteristics, building inventory and vulnerability analysis are done for risk analysis. Further members of the "Grupo de trabajo: Investigaciones aplicadas a la gestion integral del riesgo en espacios urbanos" are: Oscar Andrés López, Milgreya Cerrada, Rafael Torres, Oscar Ramírez, Elieser Sanzonetti, José Heredia, Jaime Avendaño, Fernando Mazuera, Luis Molina, Alexi Suárez, Víctor Rocabado, Mónica Paolini, Luis Yegres, Leonardo Alvarado, Herbert Rendón, Luz Rodríguez, Jorge González.

  12. Holocene evolution of the western Orinoco Delta, Venezuela

    USGS Publications Warehouse

    Aslan, A.; White, W.A.; Warne, A.G.; Guevara, E.H.

    2003-01-01

    The pristine nature of the Orinoco Delta of eastern Venezuela provides unique opportunities to study the geologic processes and environments of a major tropical delta. Remote-sensing images, shallow cores, and radiocarbon-dating of organic remains form the basis for describing deltaic environments and interpreting the Holocene history of the delta. The Orinoco Delta can be subdivided into two major sectors. The southeast sector is dominated by the Rio Grande-the principal distributary-and complex networks of anastomosing fluvial and tidal channels. The abundance of siliciclastic deposits suggests that fluvial processes such as over-bank flooding strongly influence this part of the delta. In contrast, the northwest sector is represented by few major distributaries, and overbank sedimentation is less widespread relative to the southeast sector. Peat is abundant and occurs in herbaceous and forested swamps that are individually up to 200 km2 in area. Northwest-directed littoral currents transport large volumes of suspended sediment and produce prominent mudcapes along the northwest coast. Mapping of surface sediments, vegetation, and major landforms identified four principal geomorphic systems within the western delta plain: (1) distributary channels, (2) interdistributary flood basins, (3) fluvial-marine transitional environments, and (4) marine-influenced coastal environments. Coring and radiocarbon dating of deltaic deposits show that the northern delta shoreline has prograded 20-30 km during the late Holocene sea-level highstand. Progradation has been accomplished by a combination of distributary avulsion and mudcape progradation. This style of deltaic progradation differs markedly from other deltas such as the Mississippi where distributary avulsion leads to coastal land loss, rather than shoreline progradation. The key difference is that the Orinoco Delta coastal zone receives prodigious amounts of sediment from northwest-moving littoral currents that transport sediment from as far away as the Amazon system (???1600 km). Late Holocene progradation of the delta has decreased delta-plain gradients, increased water levels, and minimized over-bank flooding and siliciclastic sedimentation in the northwest sector. These conditions, coupled with large amounts of direct precipitation, have led to widespread peat accumulation in interdistributary basins. Because peat-forming environments cover up to 5000 km2 of the delta plain, the Orinoco may be an excellent analogue for interpreting ancient deltaic peat deposits.

  13. Analysis of reservoir performance and forecasting for the eastern area of the C-2 Reservoir, Lake Maracaibo, Venezuela 

    E-print Network

    Urdaneta Anez, Jackeline C

    2001-01-01

    This research developed a numerical simulation based on the latest reservoir description to evaluate the feasibility of new infill wells to maximize the recovery specifically in the eastern region of the reservoir operated by Petroleos de Venezuela...

  14. Book Review: "Educational Reform and Administrative Development: The Cases of Columbia and Venezuela," by E. Mark Hanson.

    ERIC Educational Resources Information Center

    Lynch, Patrick D.

    1988-01-01

    Reviews "Educational Reform and Administrative Development: The Cases of Colombia and Venezuela," by E. Mark Hanson, which relates the policy-making and administrative structures of these two countries to their political, historical, and cultural contexts. (TE)

  15. Misión Madres Del Barrio: A Bolivarian Social Program Recognizing Housework and Creating A Caring Economy in Venezuela

    E-print Network

    Fischer-Hoffman, Cory

    2008-08-20

    ABSTRACT: This thesis began as a project about Misión Madres del Barrio; and it quickly transformed into a glimpse of the Bolivarian Revolution underway in Venezuela. Misión Madres del Barrio (MMB) is one of the pioneering social programs...

  16. Risk prevention and policy formulation : responding to the 1999 mud-floods catastrophe in El Litoral Central, Venezuela

    E-print Network

    Parisca-Blanco, Sonia

    2005-01-01

    Fifteen days of constant and intense rainfall in Venezuela culminated on December 16 1999, in catastrophic landslides and flooding along 25 miles of the Vargas State coastal strip. This catastrophe ravaged the Caracas ...

  17. Household energy use in urban Venezuela: Implications from surveys in Maracaibo, Valencia, Merida, and Barcelona-Puerto La Cruz

    SciTech Connect

    Figueroa, M.J.; Sathaye, J.

    1993-08-01

    This report identifies the most important results of a comparative analysis of household commercial energy use in Venezuelan urban cities. The use of modern fuels is widespread among all cities. Cooking consumes the largest share of urban household energy use. The survey documents no use of biomass and a negligible use of kerosene for cooking. LPG, natural gas, and kerosene are the main fuels available. LPG is the fuel choice of low-income households in all cities except Maracaibo, where 40% of all households use natural gas. Electricity consumption in Venezuela`s urban households is remarkably high compared with the levels used in households in comparable Latin American countries and in households of industrialized nations which confront harsher climatic conditions and, therefore, use electricity for water and space heating. The penetration of appliances in Venezuela`s urban households is very high. The appliances available on the market are inefficient, and there are inefficient patterns of energy use among the population. Climate conditions and the urban built form all play important roles in determining the high level of energy consumption in Venezuelan urban households. It is important to acknowledge the opportunities for introducing energy efficiency and conservation in Venezuela`s residential sector, particularly given current economic and financial constraints, which may hamper the future provision of energy services.

  18. Evolutionary and Ecological Characterization of Mayaro Virus Strains Isolated during an Outbreak, Venezuela, 2010.

    PubMed

    Auguste, Albert J; Liria, Jonathan; Forrester, Naomi L; Giambalvo, Dileyvic; Moncada, Maria; Long, Kanya C; Morón, Dulce; de Manzione, Nuris; Tesh, Robert B; Halsey, Eric S; Kochel, Tadeusz J; Hernandez, Rosa; Navarro, Juan-Carlos; Weaver, Scott C

    2015-10-01

    In 2010, an outbreak of febrile illness with arthralgic manifestations was detected at La Estación village, Portuguesa State, Venezuela. The etiologic agent was determined to be Mayaro virus (MAYV), a reemerging South American alphavirus. A total of 77 cases was reported and 19 were confirmed as seropositive. MAYV was isolated from acute-phase serum samples from 6 symptomatic patients. We sequenced 27 complete genomes representing the full spectrum of MAYV genetic diversity, which facilitated detection of a new genotype, designated N. Phylogenetic analysis of genomic sequences indicated that etiologic strains from Venezuela belong to genotype D. Results indicate that MAYV is highly conserved genetically, showing ?17% nucleotide divergence across all 3 genotypes and 4% among genotype D strains in the most variable genes. Coalescent analyses suggested genotypes D and L diverged ?150 years ago and genotype diverged N ?250 years ago. This virus commonly infects persons residing near enzootic transmission foci because of anthropogenic incursions. PMID:26401714

  19. KPC and VIM producing Enterobacter cloacae strain from a hospital in northeastern Venezuela.

    PubMed

    Martínez, Dianny; Marcano, Daniel; Rodulfo, Hectorina; Salgado, Nurys; Cuaical, Nirvia; Rodriguez, Lucy; Caña, Luisa; Medina, Belkis; Guzman, Militza; De Donato, Marcos

    2015-06-01

    An 83-year-old male patient is admitted to the central hospital in Cumana, Venezuela with severe urinary infection, history of hospitalizaions and prolonged antimicrobial treatments. A strain of Enterobacter cloacae was isolated showing resistance to multiple types of antibiotics (only sensitive to gentamicin), with phenotype of serine- and metallo-carbapenemases. Both, bla(VIM-2) and bla(KPC) genes were detected in the isolate. This is the first report of an Enterobacteriaceae species producing both KPC carbapenemase and VIM metallo carbapenemase in Venezuela. This finding has a great clinical and epidemiological impact in the region, because of the feasibility of transferring these genes, through mobile elements to other strains of Enterobacter and to other infection-causing species of bacteria. PMID:26299058

  20. Review of the Berosus Leach of Venezuela (Coleoptera, Hydrophilidae, Berosini) with description of fourteen new species

    PubMed Central

    Oliva, Adriana; Short, Andrew E. Z.

    2012-01-01

    Abstract The species of the water scavenger beetle genus Berosus Leach occurring in Venezuela are reviewed. Thirty-six species are recorded, including fifteen new species, fourteen of which are described here as new: Berosus aragua sp. n., Berosus asymmetricus sp. n., Berosus capanaparo sp. n., Berosus castaneus sp. n., Berosus corozo sp. n., Berosus ebeninus sp. n., Berosus garciai sp. n., Berosus humeralis sp. n., Berosus jolyi sp. n., Berosus llanensis sp. n., Berosus megaphallus sp. n., Berosus ornaticollis sp. n., Berosus repertus sp. n., and Berosus tramidrum sp. n. The fifteenth new species, known from a single female, is left undescribed pending the collection of males. Twelve species are recorded from Venezuela for the first time: Berosus ambogynus Mouchamps, Berosus consobrinus Knisch, Berosus elegans Knisch, Berosus geayi d’Orchymont, Berosus ghanicus d’Orchymont, Berosus guyanensis Queney, Berosus holdhausi Knisch, Berosus marquardti Knisch, Berosus olivae Queney, Berosus reticulatus Knisch, Berosus wintersteineri Knisch, and Berosus zimmermanni Knisch. PMID:22811607

  1. Evolutionary and Ecological Characterization of Mayaro Virus Strains Isolated during an Outbreak, Venezuela, 2010

    PubMed Central

    Auguste, Albert J.; Liria, Jonathan; Forrester, Naomi L.; Giambalvo, Dileyvic; Moncada, Maria; Long, Kanya C.; Morón, Dulce; de Manzione, Nuris; Tesh, Robert B.; Halsey, Eric S.; Kochel, Tadeusz J.; Hernandez, Rosa; Navarro, Juan-Carlos

    2015-01-01

    In 2010, an outbreak of febrile illness with arthralgic manifestations was detected at La Estación village, Portuguesa State, Venezuela. The etiologic agent was determined to be Mayaro virus (MAYV), a reemerging South American alphavirus. A total of 77 cases was reported and 19 were confirmed as seropositive. MAYV was isolated from acute-phase serum samples from 6 symptomatic patients. We sequenced 27 complete genomes representing the full spectrum of MAYV genetic diversity, which facilitated detection of a new genotype, designated N. Phylogenetic analysis of genomic sequences indicated that etiologic strains from Venezuela belong to genotype D. Results indicate that MAYV is highly conserved genetically, showing ?17% nucleotide divergence across all 3 genotypes and 4% among genotype D strains in the most variable genes. Coalescent analyses suggested genotypes D and L diverged ?150 years ago and genotype diverged N ?250 years ago. This virus commonly infects persons residing near enzootic transmission foci because of anthropogenic incursions. PMID:26401714

  2. Applications of Planktonic foraminifera in the Paleogene of the Eastern Venezuela-Trinidad Basin

    SciTech Connect

    Radford, S.

    1996-08-01

    Following increased interest in the petroleum potential of the Eastern Venezuela-Trinidad Basin, a revision of the planktonic foraminifera from the Paleogene was undertaken. The application of evolutionary trends in microperforate, medioperforate and macroperforate lineages for petroleum exploration is assessed. Scanning Electron Microscope illustrations are presented for over 100 taxa currently applied in high resolution biostratigraphy, sequence stratigraphy and paleoceanography of the region. These will allow more rapid and reliable recognition of zones, hiatuses and sequence boundaries.

  3. A new species of Piaroa (Schizomida: Hubbardiidae) from Venezuela, with taxonomic notes on the genus.

    PubMed

    M, Osvaldo Villarreal; De Armas, Luis F; García, Luis Fernando

    2014-01-01

    A new species belonging to the schizomid genus Piaroa Villarreal, Giupponi and Tourinho, 2008 is described from north-western Venezuela. A complementary description of Piaroa guipongai Villarreal and Garcia, 2012 is provided including SEM pictures of relevant structures of both sexes. A key for males of Piaroa and Colombiazomus Armas and Delgado-Santa, 2012 is included. The presence of Dm3 setae on Hubbardiidae is discussed. PMID:24870907

  4. First records of Ungla Navás (Neuroptera: Chrysopidae) from Venezuela, with descriptions of seven new species.

    PubMed

    Sosa, Francisco

    2015-01-01

    Ungla Navás is a small and relatively unstudied genus of Neotropical Chrysopini (Neuroptera: Chrysopidae: Chrysopinae) from Central and South America. Here, the genus is reported from Venezuela for the first time, and seven new species are described: Ungla demarmelsi sp. nov.; Ungla diazi sp. nov.; Ungla curimaguensis sp. nov.; Ungla martinsi sp. nov.; Ungla nigromaculifrons sp. nov.; Ungla rubricosa sp. nov.; and Ungla yutajensis sp. nov. PMID:26624036

  5. Molecular Detection and Characterization of Aichi Viruses in Sewage-Polluted Waters of Venezuela?

    PubMed Central

    Alcalá, Ana; Vizzi, Esmeralda; Rodríguez-Díaz, Jesús; Zambrano, José L.; Betancourt, Walter; Liprandi, Ferdinando

    2010-01-01

    The circulation of Aichi virus in a major urban area was demonstrated using molecular detection with samples recovered from a major river polluted with sewage discharges in Caracas, Venezuela. Five out of 11 water samples studied were positive, being classified by phylogenetic analysis as genotype B. Analysis of sewage waters appears to be a useful methodology to uncover the presence of a hitherto undetected fecal pathogen in a given geographical area. PMID:20418428

  6. Individuals in a Collectivist World: Born in the U.S.A., Teaching in Caracas, Venezuela

    ERIC Educational Resources Information Center

    Warring, Douglas F.; Huber-Warring, Tonya

    2006-01-01

    Venezuela is a country slightly larger than twice the size of California, the third largest U.S.A. state in land area. Caracas, the capitol city, is home to a population of 6 million people nested into a space that is actually smaller in size than the area of Minneapolis-St. Paul, Minnesota, U.S.A., a city/suburb of only 2.8 million people. In…

  7. New particle formation events observed at a high altitude site Pico Espejo, Venezuela

    NASA Astrophysics Data System (ADS)

    Nieminen, Tuomo; Kontkanen, Jenni; Krejci, Radovan; Ström, Johan; Tunved, Peter; Hamburger, Thomas; Calderon, Silvia; Hoffman, Pedro

    2013-05-01

    Formation and growth events of nucleation mode particles (10-25 nm in diameter) were analyzed from 27 month period of particle size distribution measurements at the high altitude site Pico Espejo in Venezuela. Particle formation was observed both in air masses connected to boundary layer air and in free tropospheric conditions. The frequency and magnitude of particle formation at this high altitude site was comparable to many observations at lower altitude sites.

  8. Potential role for Colombia and Venezuela in Pacific Rim coal trade

    SciTech Connect

    Dials, G.E.; Szpunar, C.B.

    1988-01-01

    In this paper we are going to focus on the role that two of the new entrants into the international coal market, Colombia and Venezuela, could play in a segment of the Pacific Rim Market. We will analyze their potential market capabilities and actions in terms of meeting the international coal trade demands of Japan, Hong Kong, South Korea, and Taiwan. 13 refs., 4 figs., 14 tabs.

  9. Phenotypic and molecular identification of Fonsecaea pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela.

    PubMed

    Carolina Rojas, O; León-Cachón, Rafael B R; Pérez-Maya, Antonio Alí; Aguirre-Garza, Marcelino; Moreno-Treviño, María G; González, Gloria M

    2015-05-01

    Chromoblastomycosis is a chronic granulomatous disease caused frequently by fungi of the Fonsecaea genus. The objective of this study was the phenotypic and molecular identification of F. pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela. Ten strains were included in this study. For phenotypic identification, we used macroscopic and microscopic morphologies, carbohydrate assimilation test, urea hydrolysis, cixcloheximide tolerance, proteolitic activity and the thermotolerance test. The antifungal activity of five drugs was evaluated against the isolates. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) ribosomal DNA regions of the isolated strains. The physiological analysis and morphological features were variable and the precise identification was not possible. All isolates were susceptible to itraconazole, terbinafine, voriconazole and posaconazole. Amphotericin B was the least effective drug. The alignment of the 559-nucleotide ITS sequences from our strains compared with sequences of GenBank revealed high homology with F. pedrosoi (EU285266.1). In this study, all patients were from rural areas, six from Mexico and four from Venezuela. Ten isolates were identified by phenotypic and molecular analysis, using ITS sequence and demonstrated that nine isolates from Mexico and Venezuela were 100% homologous and one isolate showed a small genetic distance. PMID:25728464

  10. Wood anatomy of tribe Detarieae and comparison with tribe Caesalpinieae (Leguminosae, Caesalpinioideae) in Venezuela.

    PubMed

    Melandri, José Luis; de Pernía, Narcisana Espinoza

    2009-01-01

    We studied the wood anatomy of 29 species belonging to 10 genera of the tribe Detarieae, subfamily Caesalpinioideae and compare them with tribe Caesalpinieae. Detarieae is the largest of four tribes of Caesalpinioideae, with 84 genera, only eleven occur in Venezuela with species of timber importance. The specimens were collected in Venezuela and include wood samples from the collection of the Laboratorio de Anatomía de Maderas de la Facultad de Ciencias Forestales y Ambientales de la Universidad de Los Andes, Venezuela, and of the Forest Products Laboratory of the USDA Forest Service in Madison, Wisconsin, USA. The terminology and methodology used followed the IAWA List of Microscopic Features for Hardwood Identification of the IAWA Committee, 1989. Measurements from each specimen were averaged (vessel diameters, vessel element lengths, intervessels pit size, fibre lengths and ray height). The species of Detarieae can be separated using a combination of diagnostic features. Wood characters that provide the most important diagnosis and may be used in systematics of Detarieae include: intercellular axial canals, rays heterocellular, rays exclusively or predominantly uniseriate, prismatic crystals common in ray cells, irregular storied structure and fibre wall thickness. For comparative anatomy between Detarieae and Caesalpinieae: intercellular axial canals, heterocellular rays, rays exclusively or predominantly uniseriate, prismatic crystals common in ray cells (in Detarieae) and regular storied structure, fibres septate, fibre wall thick or very thick, rays homocellular, multiseriate rays and silica bodies (in Caesalpinieae). Axial parenchyma is typically a good diagnostic feature for Leguminosae, but not for Detarieae and Caesalpinieae comparisons. PMID:19637709

  11. Distribution, status, and traditional significance of the West Indian manatee Trichechus manatus in Venezuela

    USGS Publications Warehouse

    O'Shea, Thomas J.; Correa-Viana, Martín; Ludlow, Mark E.; Robinson, John G.

    1988-01-01

    Aerial and interview surveys were conducted in 1986 to determine the current distribution, status, and traditional significance of the West Indian manatee Trichechus manatus in Venezuela. Aerial surveys provided just eight tentative sightings in 73 hours of searching. These discouraging results may have been due to poor visibility, small populations, and perhaps reduced dry season manatee activity. Results of interview surveys, however, permitted a number of important generalizations. A remnant manatee population exists in Lake Maracaibo, but none occur along the more than 1500 km of Caribbean coastline. Abundance is greatest in eastern Venezuela bordering the Golfo de Paria, in the Orinoco Delta, and in the middle Orinoco and tributaries. Local market hunting in the middle of this century probably greatly reduced manatee populations in these areas. Recent protection laws, education efforts, and manatee scarcity have resulted in a declining interest in manatee hunting. Much excellent manatee habitat persists in these regions, and a continued decline in hunting could result in an optimistic outlook for future manatee populations if the incidental take in net fisheries is controlled. Traditional beliefs and legends concerning manatees in Venezuela, including hunting taboos, show that these animals remain a colorful part of the folk culture. However, manatee protection does not pose economic hardships or infringe upon traditional spiritual beliefs.

  12. FRONTISPIECE. Three-striped Warblers (Basileuterus tristriatus) were studied in the northern Andes of Venezuela. Temperate and tropical parulids differ strongly in life histories. Three-striped Warblers have smaller clutches, longer

    E-print Network

    Martin, Thomas E.

    of Venezuela. Temperate and tropical parulids differ strongly in life histories. Three-striped Warblers have(4):667­678, 2009 BREEDING BIOLOGY OF THE THREE-STRIPED WARBLER IN VENEZUELA: A CONTRAST BETWEEN TROPICAL traits of the Three-striped Warbler (Basileuterus tristriatus) from 146 nests in Venezuela and compare

  13. Evolution of Dengue Virus Type 3 Genotype III in Venezuela: Diversification, Rates and Population Dynamics

    PubMed Central

    2010-01-01

    Background Dengue virus (DENV) is a member of the genus Flavivirus of the family Flaviviridae. DENV are comprised of four distinct serotypes (DENV-1 through DENV-4) and each serotype can be divided in different genotypes. Currently, there is a dramatic emergence of DENV-3 genotype III in Latin America. Nevertheless, we still have an incomplete understanding of the evolutionary forces underlying the evolution of this genotype in this region of the world. In order to gain insight into the degree of genetic variability, rates and patterns of evolution of this genotype in Venezuela and the South American region, phylogenetic analysis, based on a large number (n = 119) of envelope gene sequences from DENV-3 genotype III strains isolated in Venezuela from 2001 to 2008, were performed. Results Phylogenetic analysis revealed an in situ evolution of DENV-3 genotype III following its introduction in the Latin American region, where three different genetic clusters (A to C) can be observed among the DENV-3 genotype III strains circulating in this region. Bayesian coalescent inference analyses revealed an evolutionary rate of 8.48 × 10-4 substitutions/site/year (s/s/y) for strains of cluster A, composed entirely of strains isolated in Venezuela. Amino acid substitution at position 329 of domain III of the E protein (A?V) was found in almost all E proteins from Cluster A strains. Conclusions A significant evolutionary change between DENV-3 genotype III strains that circulated in the initial years of the introduction in the continent and strains isolated in the Latin American region in recent years was observed. The presence of DENV-3 genotype III strains belonging to different clusters was observed in Venezuela, revealing several introduction events into this country. The evolutionary rate found for Cluster A strains circulating in Venezuela is similar to the others previously established for this genotype in other regions of the world. This suggests a lack of correlation among DENV genotype III substitution rate and ecological pattern of virus spread. PMID:21087501

  14. Receiver Functions Imaging of the Moho and LAB in the Southern Caribbean plate boundary and Venezuela

    NASA Astrophysics Data System (ADS)

    Masy, J.; Levander, A.; Niu, F.

    2011-12-01

    We have made teleseismic Ps and Sp receiver functions from data recorded from 2003 to 2009 by the permanent national seismic network of Venezuela, the BOLIVAR (Broadband Onshore-offshore Lithospheric Investigation of Venezuela and the Antilles arc Region) and WAVE (Western Array for Venezuela) experiments. The receiver functions show rapid variations in Moho and lithosphere-asthenosphere boundary (LAB) depths both across and along the southern Caribbean plate boundary region. We used a total of 69 events with Mw > 6 occurring at epicentral distances from 30° to 90° for the Ps receiver functions, and 43 events with Mw > 5.7 from 55° to 85° to make Sp receiver functions. For CCP stacking we constructed a 3D velocity model from numerous active source profiles (Schmitz et al., 2001; Bezada et al., 2007; Clark et al., 2008; Guedez, 2008; Magnani et al., 2009), from finite-frequency P wave upper mantle tomography model of Bezada et al., (2010) and the Rayleigh wave tomography model of Miller et al., (2009). The Moho ranges in depth from ~25 km beneath the Caribbean Large Igneous Provinces to ~55 km beneath the Mérida Andes in western Venezuela. These results are consistent with previous receiver functions studies (Niu et al., 2007) and the available active source profiles. Beneath the Maracaibo Block in northwestern Venezuela, we observe a strong positive signal at 40 to 60 km depth dipping ~6° towards the continent. We interpret this as the Moho of the Caribbean slab subducting beneath northernmost South America from the west. Beneath northern Colombia and northwestern Venezuela the top of this slab has been previously inferred from intermediate depth seismicity (Malavé and Suarez, 1995), which indicates a slab dipping between 20° - 30° beneath Lake Maracaibo. Our results could indicate that the slab is tearing beneath Lake Maracaibo as suggested previously by Masy et al. (2011). The deeper (> 100 km depth) part of the slab has been imaged using P-wave tomography (Bezada et al, 2010). Like others we attribute the uplift of the Mérida Andes to flat Caribbean slab subduction (for example Kellogg and Bonini, 1982). In central Venezuela beneath the Cordillera de la Costa we observe a positive signal shallower than the Moho at <30 km depth beneath the entire range. We interpret this as a detachment surface beneath Caribbean & arc terranes thrust onto the SA margin (Bezada et al., 2010). The lithosphere-asthenosphere boundary (LAB) beneath the Mérida Andes is shallow, ~65km depth, and parallels the range. In the plate boundary region under the Cordillera de la Costa the lithosphere is also thin, ~65km, beneath the Cariaco basin the lithosphere thickens to 85 km. In the far east under Serranía del Interior the lithosphere is ~75 km. Cratonic lithosphere thickness varies from 85 to 100 km.

  15. Lithospheric Expressions of the Precambrian Shield, Mesozoic Rifting, and Cenozoic Subduction and Mountain Building in Venezuela

    NASA Astrophysics Data System (ADS)

    Levander, A.; Masy, J.; Niu, F.

    2013-05-01

    The Caribbean (CAR)-South American (SA) plate boundary in Venezuela is a broad zone of faulting and diffuse deformation. GPS measurements show the CAR moving approximately 2 cm/yr relative to SA, parallel to the strike slip fault system in the east, with more oblique convergence in the west (Weber et al., 2001) causing the southern edge of the Caribbean to subduct beneath northwestern South America. The west is further complicated by the motion of the triangular Maracaibo block, which is escaping northeastward relative to SA along the Bocono and Santa Marta Faults. In central and eastern Venezuela, plate motion is accommodated by transpression and transtension along the right lateral San Sebastian- El Pilar strike-slip fault system. The strike-slip system marks the northern edge of coastal thrust belts and their associated foreland basins. The Archean-Proterozoic Guayana Shield, part of the Amazonian Craton, underlies southeastern and south-central Venezuela. We used the 87 station Venezuela-U.S. BOLIVAR array (Levander et al., 2006) to investigate lithospheric structure in northern South America. We combined finite-frequency Rayleigh wave tomography with Ps and Sp receiver functions to determine lithosphere-asthenosphere boundary (LAB) depth. We measured Rayleigh phase velocities from 45 earthquakes in the period band 20-100s. The phase velocities were inverted for 1D shear velocity structure on a 0.5 by 0.5 degree grid. Crustal thickness for the starting model was determined from active seismic experiments and receiver function analysis. The resulting 3D shear velocity model was then used to determine the depth of the LAB, and to CCP stack Ps and Sp receiver functions from ~45 earthquakes. The receiver functions were calculated in several frequency bands using iterative deconvolution and inverse filtering. Lithospheric thickness varies by more a factor of 2.5 across Venezuela. We can divide the lithosphere into several distinct provinces, with LAB depth reflecting the signatures of the Precambrian craton in the south, Mesozoic rifting in central Venezuela, and Neogene subduction and orogenesis in both the northeast and northwest. Specifically, LAB depth varies from 110-130 km beneath the Guayana Shield, in agreement with finite-frequency body wave tomography (Bezada et al., 2010b). To the north beneath the Serrania del Interior and Maturin Basin the Rayleigh waves image two high velocity features to depths of 200 km. The northernmost, beneath the Serrania, corresponds to the top of the subducting Atlantic plate, in agreement with P-wave tomography that images the Atlantic plate to transition zone depths. Another localized high velocity feature extending to ~200 km depth lies to the south. We speculate that this is a lithospheric drip caused by destabilization of the SA lithospheric caused by Atlantic subduction. Immediately to the west beneath the Cariaco basin the LAB is at ~50 km, marking the top of a pronounced low velocity zone. The thin lithosphere extends southwestward from the Cariaco Basin beneath the Mesozoic Espino Graben to the craton. To the west the LAB deepens to ~80 km beneath the Barinas Apure Basin and then to ~90 km beneath the Neogene Merida Andes and Maracaibo block.

  16. pfmdr1 Amplification and Fixation of pfcrt Chloroquine Resistance Alleles in Plasmodium falciparum in Venezuela ? †

    PubMed Central

    Griffing, Sean; Syphard, Luke; Sridaran, Sankar; McCollum, Andrea M.; Mixson-Hayden, Tonya; Vinayak, Sumiti; Villegas, Leopoldo; Barnwell, John W.; Escalante, Ananias A.; Udhayakumar, Venkatachalam

    2010-01-01

    Molecular tools are valuable for determining evolutionary history and the prevalence of drug-resistant malaria parasites. These tools have helped to predict decreased sensitivity to antimalarials and fixation of multidrug resistance genotypes in some regions. In order to assess how historical drug policies impacted Plasmodium falciparum in Venezuela, we examined molecular changes in genes associated with drug resistance. We examined pfmdr1 and pfcrt in samples from Sifontes, Venezuela, and integrated our findings with earlier work describing dhfr and dhps in these samples. We characterized pfmdr1 genotypes and copy number variation, pfcrt genotypes, and proximal microsatellites in 93 samples originating from surveillance from 2003 to 2004. Multicopy pfmdr1 was found in 12% of the samples. Two pfmdr1 alleles, Y184F/N1042D/D1246Y (37%) and Y184F/S1034C/N1042D/D1246Y (63%), were found. These alleles share ancestry, and no evidence of strong selective pressure on mutations was found. pfcrt chloroquine resistance alleles are fixed with two alleles: StctVMNT (91%) and SagtVMNT (9%). These alleles are associated with strong selection. There was also an association between pfcrt, pfmdr1, dhfr, and dhps genotypes/haplotypes. Duplication of pfmdr1 suggests a potential shift in mefloquine sensitivity in this region, which warrants further study. A bottleneck occurred in P. falciparum in Sifontes, Venezuela, and multidrug resistance genotypes are present. This population could be targeted for malaria elimination programs to prevent the possible spread of multidrug-resistant parasites. PMID:20145087

  17. [Case reports of drug-induced liver injury in a reference hospital of Zulia state, Venezuela].

    PubMed

    Mengual-Moreno, Edgardo; Lizarzábal-García, Maribel; Ruiz-Soler, María; Silva-Suarez, Niniveth; Andrade-Bellido, Raúl; Lucena-González, Maribel; Bessone, Fernando; Hernández, Nelia; Sánchez, Adriana; Medina-Cáliz, Inmaculada

    2015-03-01

    Drug-induced liver injury (DILI) is an important cause of morbidity and mortality worldwide, with varied geographical differences. The aim of this prospective, descriptive, cross-sectional study was to identify and characterize cases of DILI in a hospital of Zulia state, Venezuela. Thirteen patients with a presumptive diagnosis of DILI attended by the Department of Gastroenterology, Hospital Universitario, Zulia state, Venezuela, from December-2012 to December-2013 were studied. Ibuprofen (n = 3; 23.1%), acetaminophen (n = 3; 23.1), isoniazid (n = 2; 15.4%) and Herbalife products (n = 2; 15.4%) were the main drugs involved with DILI. Acetaminophen and ibuprofen showed a mixed pattern of liver injury (n = 3; 23.1%) and isoniazid presented a hepatocellular pattern (n = 2; 15.4%). The CIOMS/RUCAMS allowed the identification of possible (n = 7; 53.9%), probable (n = 4; 30.8%) and highly-probable cases (n = 2; 15.4%) of DILI. Amoxicillin/clavulanate, isoniazid, isotretinoin, methotrexate and Herbalife nutritional products were implicated as highly-probable and probable agents. The highest percentage of DILI corresponded to mild cases that recovered after the discontinuation of the agent involved (n = 9; 69.3%). The consumption of Herbalife botanical products is associated with probable causality and fatality (n = 1; 7.7%). In conclusion, the frequency of DILI cases controlled by the Department of Gastroenterology of the Hospital Universitario of Maracaibo was low, being ibuprofen, acetaminophen, isoniazid and products Herbalife the products most commonly involved. It is recommended to continue with the prospective registration of cases, with an extended follow up monitoring period and to facilitate the incorporation of other hospitals in the Zulia State and Venezuela. PMID:25920181

  18. [Urban construction, professions, and immigration at the origin of urban studies in Venezuela, 1870-1957].

    PubMed

    Martin Frechilla, J J

    1996-01-01

    The individuals and circumstances involved in the creation of the first graduate urban studies program in Venezuela are recalled, beginning with the odernization of Caracas under the impulse of President Antonio Guzman Blanco, elected in 1870. Guzman Blanco converted himself into Venezuela's first urbanist with the establishment of organizational frameworks and completion of massive public works projects, which were based largely on the urban models of the US and Europe. Engineering and public health were consolidated as the two most influential sources of professional competence for guiding urban development. By the mid-1930s, growth fueled by petroleum revenues was causing rapid urbanization, and it became apparent that trained professionals able to manage the increasingly complex tasks of urban planning were in short supply. A new surge of modernizing construction began in 1936 and led to a cooperative arrangement with a French firm, whose personnel were to be required to train Venezuelan engineers for future service in urban planning. An influx of refugees from the Spanish Civil War and the increasing influence of urban planning processes in the US were also observed. The National Commission on Urbanism was created in 1946 as a dependency of the Ministry of Planning to facilitate public administration of the development and control of cities. Throughout the period, a debate was underway on the need for a multidisciplinary approach to urban planning versus a primarily architectural or engineering approach. In 1957, some consensus was reached on the need for urban planning to be viewed as more than a speciality of architecture. A framework was developed for a graduate program in 1969 in the Central University of Venezuela. The National Commission on Urbanism was disbanded in 1957, largely because of its excessive focus on architecture to the exclusion of other disciplines relevant to the urbanization process. PMID:12321404

  19. Residential energy use and conservation in Venezuela: Results and implications of a household survey in Caracas

    SciTech Connect

    Figueroa, M.J.; Ketoff, A.; Masera, O.

    1992-10-01

    This document presents the final report of a study of residential energy use in Caracas, the capital of Venezuela. It contains the findings of a household energy-use survey held in Caracas in 1988 and examines options for introducing energy conservation measures in the Venezuelan residential sector. Oil exports form the backbone of the Venezuelan economy. Improving energy efficiency in Venezuela will help free domestic oil resources that can be sold to the rest of the world. Energy conservation will also contribute to a faster recovery of the economy by reducing the need for major investments in new energy facilities, allowing the Venezuelan government to direct its financial investments towards other areas of development. Local environmental benefits will constitute an important additional by-product of implementing energy-efficiency policies in Venezuela. Caracas`s residential sector shows great potential for energy conservation. The sector is characterized by high saturation levels of major appliances, inefficiency of appliances available in the market, and by careless patterns of energy use. Household energy use per capita average 6.5 GJ/per year which is higher than most cities in developing countries; most of this energy is used for cooking. Electricity accounts for 41% of all energy use, while LPG and natural gas constitute the remainder. Specific options for inducing energy conservation and energy efficiency in Caracas`s residential sector include energy-pricing policies, fuel switching, particularly from electricity to gas, improving the energy performance of new appliances and customer information. To ensure the accomplishment of an energy-efficiency strategy, a concerted effort by energy users, manufacturers, utility companies, government agencies, and research institutions will be needed.

  20. Monitoring of organophosphorus pesticide residues in vegetables of agricultural area in Venezuela.

    PubMed

    Quintero, América; Caselles, María J; Ettiene, Gretty; de Colmenares, Nélida G; Ramírez, Tibisay; Medina, Deisy

    2008-10-01

    The purpose of this study was to determine the residues of seven pesticides organophosphorus (methamidophos, diazinon, chlorpyriphos, parathion-methyl, dimethoate, malathion and tetrachlorvinphos), in some vegetables like: potato, lettuce, tomato, onion, red pepper and green onion cultivated in José María Vargas County in Táchira State, Venezuela. The research permitted to detect that 48.0% of the samples were contaminated with some of the pesticides studied. Methamidophos was founded in the vegetables in the rank of 6.3%-65.5%. The results show that 16.7% of the samples tested have residues higher than the maximum limits permitted. PMID:18766290

  1. Sentinel Surveillance of Influenza-Like Illness in Two Hospitals in Maracay, Venezuela: 2006–2010

    PubMed Central

    Comach, Guillermo; Teneza-Mora, Nimfa; Kochel, Tadeusz J.; Espino, Carlos; Sierra, Gloria; Camacho, Daria E.; Laguna-Torres, V. Alberto; Garcia, Josefina; Chauca, Gloria; Gamero, Maria E.; Sovero, Merly; Bordones, Slave; Villalobos, Iris; Melchor, Angel; Halsey, Eric S.

    2012-01-01

    Background Limited information exists on the epidemiology of acute febrile respiratory illnesses in tropical South American countries such as Venezuela. The objective of the present study was to examine the epidemiology of influenza-like illness (ILI) in two hospitals in Maracay, Venezuela. Methodology/Principal Findings We performed a prospective surveillance study of persons with ILI who presented for care at two hospitals in Maracay, Venezuela, from October 2006 to December 2010. A respiratory specimen and clinical information were obtained from each participant. Viral isolation and identification with immunofluorescent antibodies and molecular methods were employed to detect respiratory viruses such as adenovirus, influenza A and B, parainfluenza, and respiratory sincytial virus, among others. There were 916 participants in the study (median age: 17 years; range: 1 month – 86 years). Viruses were identified in 143 (15.6%) subjects, and one participant was found to have a co-infection with more than one virus. Influenza viruses, including pandemic H1N1 2009, were the most frequently detected pathogens, accounting for 67.4% (97/144) of the viruses detected. Adenovirus (15/144), parainfluenza virus (13/144), and respiratory syncytial virus (11/144) were also important causes of ILI in this study. Pandemic H1N1 2009 virus became the most commonly isolated influenza virus during its initial appearance in 2009. Two waves of the pandemic were observed: the first which peaked in August 2009 and the second - higher than the preceding - that peaked in October 2009. In 2010, influenza A/H3N2 re-emerged as the most predominant respiratory virus detected. Conclusions/Significance Influenza viruses were the most commonly detected viral organisms among patients with acute febrile respiratory illnesses presenting at two hospitals in Maracay, Venezuela. Pandemic H1N1 2009 influenza virus did not completely replace other circulating influenza viruses during its initial appearance in 2009. Seasonal influenza A/H3N2 was the most common influenza virus in the post-pandemic phase. PMID:22984519

  2. Case report: Molecular evidence of Anaplasma platys infection in two women from Venezuela.

    PubMed

    Arraga-Alvarado, Cruz M; Qurollo, Barbara A; Parra, Omaira C; Berrueta, Maribel A; Hegarty, Barbara C; Breitschwerdt, Edward B

    2014-12-01

    This article presents two case reports of Anaplasma platys detection in two women from Venezuela. Both patients were exposed to Rhipicephalus sanguineus, the presumed tick vector, and experienced chronic, nonspecific clinical signs including headaches and muscle pains. Intra-platelet inclusion bodies resembling A. platys were observed in buffy coat smears and A. platys DNA was amplified and sequenced from whole blood; however, treatment with doxycycline did not alleviate their symptoms. These cases provide further support for A. platys as a zoonotic tick-borne pathogen, most likely of low pathogenicity; nonetheless, the cause of illness in humans by A. platys is yet to be confirmed. PMID:25266347

  3. Molecular Evidence of Anaplasma platys Infection in Two Women from Venezuela

    PubMed Central

    Arraga-Alvarado, Cruz M.; Qurollo, Barbara A.; Parra, Omaira C.; Berrueta, Maribel A.; Hegarty, Barbara C.; Breitschwerdt, Edward B.

    2014-01-01

    This article presents two case reports of Anaplasma platys detection in two women from Venezuela. Both patients were exposed to Rhipicephalus sanguineus, the presumed tick vector, and experienced chronic, nonspecific clinical signs including headaches and muscle pains. Intra-platelet inclusion bodies resembling A. platys were observed in buffy coat smears and A. platys DNA was amplified and sequenced from whole blood; however, treatment with doxycycline did not alleviate their symptoms. These cases provide further support for A. platys as a zoonotic tick-borne pathogen, most likely of low pathogenicity; nonetheless, the cause of illness in humans by A. platys is yet to be confirmed. PMID:25266347

  4. A study on the genus Agrilaxia Kerremans, 1903 from Venezuela (Coleoptera: Buprestidae: Buprestinae: Anthaxiini).

    PubMed

    Bílý, Svatopluk

    2015-01-01

    Study on the genus Agrilaxia Kerremans, 1903 from Venezuela. Altogether eight species were recorded from this country, four of them are described in this paper: Agrilaxia (Agrilaxia) biformis sp. nov., A. (A.) michaeli sp. nov., A. (A.) stephani sp. nov. and A. (A.) venezuelana sp. nov. All species are illustrated and new species are compared with the most similar/related species. A male of Agrilaxia (A.) balloui Fisher, 1942 is described and the male genitalia are illustrated. New country records are given for Agrilaxia (A.) balloui, A. (A.) costaricensis Obenberger, 1922, A. (A.) glabra Bílý & Brûlé 2013 and A. (A.) simillima Cobos, 1972. PMID:26624473

  5. Diurnal raptors in the fragmented rain forest of the Sierra Imataca, Venezuela

    USGS Publications Warehouse

    Alvarez, E.; Ellis, D.H.; Smith, D.G.; LaRue, C.T.

    1996-01-01

    The rain forest of the Sierra Imataca in eastern Venezuela has been subjected to extensive deforestation for pastures and agricultural settlements. In the last decade the opening of access roads combined with intensified logging and mining activities have fragmented a significant portion of the remaining forest. We noted local distribution and habitat use for 42 species of diurnal raptors observed in affected areas in this region. We observed some raptors considered as forest interior species and other open country species foraging and roosting in man-made openings inside the forest.

  6. Diurnal raptors in the fragmented rain forest of the Sierra Imataca, Venezuela

    USGS Publications Warehouse

    Alvarez, E.; Ellis, D.H.; Smith, D.G.; LaRue, C.T.

    1994-01-01

    The rain forest of the Sierra Imataca in eastern Venezuela has been subjected to extensive deforestation for pastures and agricultural settlements. In the last decade the opening of access roads combined with intensified logging and mining activities have fragmented a significant portion of the remaining forest. We noted local distribution and habitat use for 40 species of diurnal raptors observed in ten affected areas, including raptors considered as forest interior species and some open country species utilizing the man-made openings inside the forest for roosting and foraging.

  7. (Late?) Paleozoic age for the “Cretaceous” Tucutunemo Formation, northern Venezuela: Stratigraphic and tectonic implications

    NASA Astrophysics Data System (ADS)

    Benjamini, C.; Shagam, R.; Menendez, A.

    1987-10-01

    The largely phyllitic Tucutunemo Formation of the Caribbean Mountains of north-central Venezuela has been assigned to the Early or Late Cretaceous on the basis of lithologic correlation. Reexamination of some limestones in thin section revealed a crinoid-brachiopod microfacies in which productid spine bases and sections were identified. Other forms include bryozoans, probable dasyclad algae, and a possible chaetetid. The microfacies closely resemble those of limestones of the Permian Palmarito Formation of the Venezuelan Andes. These features suggest a (late?) Paleozoic age for the Tucutunemo Formation. A range of possible tectonic settings for the formation is summarized in two autochthonous and two allochthonous models.

  8. Evaluacion de Programas de Alfabetizacion. Consulta Tecnica Regional (Maracaibo, Venezuela, 30 Noviembre-6 Diciembre 1987) Informe Final. (Evaluation of Literacy Programs. Regional Technical Meeting (Maracaibo, Venezuela, November 30-December 6, 1987).

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Santiago (Chile). Regional Office for Education in Latin America and the Caribbean.

    The objectives of this seminar were to identify problems in evaluating literacy programs and to design a working strategy to confront them. Four presentations included national case studies from Brazil, Honduras, Nicaragua, and Venezuela. Central questions asked concerned who and what were evaluated and how were the results to be used. In Brazil,…

  9. Preliminary assessment of a Cretaceous-Paleogene Atlantic passive margin, Serrania del Interior and Central Ranges, Venezuela/Trinidad

    SciTech Connect

    Pindell, J.L.; Drake, C.L. ); Pitman, W.C. )

    1991-03-01

    For several decades, Cretaceous arc collision was assumed along northern Venezuela based on isotopic ages of metamorphic minerals. From subsidence histories in Venezuelan/Trinidadian basins, however, it is now clear that the Cretaceous metamorphic rocks were emplaced southeastward as allochthons above an autochthonous suite of rocks in the Cenozoic, and that the pre-Cenozoic autochthonous rocks represent a Mesozoic passive margin. The passive margin rocks have been metamorphosed separately during overthrusting by the allochthons in central Venezuela, but they are uplifted but not significantly metamorphosed in Eastern Venezuela and Trinidad. There, in the Serrania del Interior and Central Ranges of Venezuela/Trinidad, Mesozoic-Paleogene passive margin sequences were uplifted in Neogene time, when the Caribbean Plate arrived from the west and transpressionally inverted the passive margin. Thus, this portion of South America's Atlantic margin subsided thermally without tectonism from Jurassic to Eocene time, and these sections comprise the only Mesozoic-Cenozoic truly passive Atlantic margin in the Western Hemisphere that is now exposed for direct study. Direct assessments of sedimentological, depositional and faunal features indicative of, and changes in, water depth for Cretaceous and Paleogene time may be made here relative to a thermally subsiding passive margin without the complications of tectonism. Work is underway, and preliminary assessments presented here suggest that sea level changes of Cretaceous-Paleogene time are not as pronounced as the frequent large and rapid sea level falls and rises that are promoted by some.

  10. Molecular Characterization of Sewage-Borne Pathogens and Detection of Sewage Markers in an Urban Stream in Caracas, Venezuela?

    PubMed Central

    Betancourt, W. Q.; Querales, L.; Sulbaran, Y. F.; Rodriguez-Diaz, J.; Caraballo, L.; Pujol, F. H.

    2010-01-01

    Molecular characterization of two sewage-borne pathogens identified hepatitis A virus (HAV) subgenotype IA and Giardia duodenalis assemblages A and B as predominant genotypes circulating in an urban area of Venezuela. This study reveals epidemiological features of human pathogens of worldwide distribution and the efficacy of molecular methods for accurate assessment of sewage pollution. PMID:20097824

  11. Two new Fusicoccum species from Acacia and Eucalyptus in Venezuela, based on morphology and DNA sequence data

    E-print Network

    Two new Fusicoccum species from Acacia and Eucalyptus in Venezuela, based on morphology and DNA of woody plants, and they also include some serious pathogens of Eucalyptus and Acacia species. Numerous common. Here, we characterize two new Fusicoccum species, isolated from Eucalyptus and Acacia trees

  12. Are Returns to Education on the Decline in Venezuela and Does Mission Sucre Have a Role to Play?

    ERIC Educational Resources Information Center

    Gonzalez, Naihobe; Oyelere, Ruth Uwaifo

    2011-01-01

    Anecdotal evidence points to a falling standard of living for the educated in Venezuela. During this same period, President Hugo Chavez implemented several education reforms. We focus on a major university education reform known as Mission Sucre and its potential impact on returns to university education. First, we show that returns to education…

  13. Antifungal Susceptibilities, Varieties, and Electrophoretic Karyotypes of Clinical Isolates of Cryptococcus neoformans from Brazil, Chile, and Venezuela

    PubMed Central

    Calvo, Belinda M.; Colombo, Arnaldo L.; Fischman, Olga; Santiago, A.; Thompson, L.; Lazera, Marcia; Telles, Flavio; Fukushima, Kazutaka; Nishimura, Kazuko; Tanaka, Reiko; Myiajy, Makoto; Moretti-Branchini, M. Luiza

    2001-01-01

    One hundred clinical isolates of Cryptococcus neoformans from human immunodeficiency virus (HIV)-infected and non-HIV-infected patients from Brazil, Chile, and Venezuela were separated according to varieties and tested for antifungal susceptibility. A high susceptibility to antifungal agents was observed among all the isolates. The electrophoretic karyotyping of 51 strains revealed good discrimination among Cryptococcus neoformans var. neoformans strains. PMID:11376089

  14. Hydrolutos gransabanensis sp.n. (Orthoptera: Anostostomatidae), a new semi-aquatic Lutosini species from Gran Sabana (Venezuela).

    PubMed

    Derka, Tomás; Fedor, Peter; Svitok, Marek; Trizna, Milan

    2013-01-01

    Hydrolutos gransabanensis, a new species of Lutosini (Orthoptera: Anostostomatidae) from the cave Cueva El Tigre (Santa Elena de Uairén, SE Venezuela) is described and figured for both sexes. This is the first record of Hydrolutos species out of tepui systems. The genus is recently known by 6 apterous species from Venezuelan Guayana region. PMID:25243298

  15. Comparison of the petroleum systems of East Venezuela in their tectonostratigraphic context

    SciTech Connect

    Stronach, N.J.; Kerr, H.M.; Scotchmer, J.; Hunter, V.

    1996-08-01

    The Maturin and Guarico subbasins of East Venezuela record the transition from Cretaceous passive margin to Tertiary foreland basin with local post-orogenic transtensional basins. Petroleum is reservoired in several units ranging from Albian (El Cantil Formation) to Pliocene (Las Piedras Formation) age. Source rocks are principally in the Upper Cretaceous (Querecual Formation), and Miocene (Carapita Formation) in the Maturin subbasin and in the Upper Cretaceous (Tigre Formation) and Oligocene (Roblecito and La Pascua Formations) in the Guarico subbasin. An extensive well database has been used to address the distribution and provenance of hydrocarbons in the context of a tectonostratigraphic model for the evolution of the East Venezuela basin. Nine major plays have been described, comprising thirteen petroleum systems. The principal factors influencing the components of individual petroleum systems are as follows: (1) structural controls on Upper Cretaceous source rock distribution, relating to block faulting on the proto-Caribbean passive margin; (2) paleoenvironmental controls on source rock development within the Oligocene-Miocene foreland basin; and (3) timing of subsidence and maturation within the Oligocene-Upper Miocene foreland basin and the configuration of the associated fold and thrust belt, influencing long range and local migration routes (4) local development of Pliocene post-orogenic transtensional basins, influencing hydrocarbon generation, migration and remigration north of the Pirital High.

  16. Paleogeographic evolution of foldbelts adjacent to petroleum basins of Venezuela and Trinidad

    SciTech Connect

    Goodman, E.D.; Koch, P.S.; Summa, L.L.

    1996-08-01

    The foldbelts of Venezuela and Trinidad have shaped the history of adjacent sedimentary basins. A set of paleogeographic maps on reconstructed bases depict the role of foldbelts in the development of the sedimentary basins of Venezuela. Some of the foldbelts are inverted, pre-Tertiary graben/passive margin systems. Other foldbelts are allochthonous nappes or parautochthons that override the Mesozoic passive margin hinge without inversion. The emergence of these foldbelts changed the course of existing river systems and provided a new source for sediments and maturation in adjacent deeps. The Merida Andes area was remobilized beginning in the Early Miocene as a zone of lateral shear, along which the Bonaire Block has moved over 200 km to the northeast, dismembering the Maracaibo and Barinas basins. Late Miocene to Recent transpression and fault reactivation have driven rapid Andean uplift with thrust-related subsidence and maturation (e.g., SE Maracaibo foredeep). To the east, uplift and erosion of the Serrania del Interior (1) curtailed mid-Tertiary fluvial systems flowing northward from the igneous and sedimentary rocks of the Guyana Shield, deflecting them eastward, and (2) removed the thick early Miocene foredeep fill into a younger foredeep. Thus, the fold-thrust belts and sedimentary basins in this region are linked in their evolutionary histories.

  17. An Estimate of Recoverable Heavy Oil Resources of the Orinoco Oil Belt, Venezuela

    USGS Publications Warehouse

    Schenk, Christopher J.; Cook, Troy A.; Charpentier, Ronald R.; Pollastro, Richard M.; Klett, Timothy R.; Tennyson, Marilyn E.; Kirschbaum, Mark A.; Brownfield, Michael E.; Pitman, Janet K.

    2009-01-01

    The Orinoco Oil Belt Assessment Unit of the La Luna-Quercual Total Petroleum System encompasses approximately 50,000 km2 of the East Venezuela Basin Province that is underlain by more than 1 trillion barrels of heavy oil-in-place. As part of a program directed at estimating the technically recoverable oil and gas resources of priority petroleum basins worldwide, the U.S. Geological Survey estimated the recoverable oil resources of the Orinoco Oil Belt Assessment Unit. This estimate relied mainly on published geologic and engineering data for reservoirs (net oil-saturated sandstone thickness and extent), petrophysical properties (porosity, water saturation, and formation volume factors), recovery factors determined by pilot projects, and estimates of volumes of oil-in-place. The U.S. Geological Survey estimated a mean volume of 513 billion barrels of technically recoverable heavy oil in the Orinoco Oil Belt Assessment Unit of the East Venezuela Basin Province; the range is 380 to 652 billion barrels. The Orinoco Oil Belt Assessment Unit thus contains one of the largest recoverable oil accumulations in the world.

  18. Settlement patterns in the eastern coast of Maracaibo Lake, Venezuela : evaluation of existing settlements and model for a low income sector of El Menito new town

    E-print Network

    Rodriguez Navas, Humberto José

    1983-01-01

    This thesis is divided in two parts; The First part is the physical analysis of residential settlements in the Eastern Coast of Maracaibo Lake, Venezuela. The work is based on surveys, evaluations and comparisons of four ...

  19. Karyotype of the invasive species Pterois volitans (Scorpaeniformes: Scorpaenidae) from Margarita Island, Venezuela.

    PubMed

    Nirchio, Mauro; Ehemann, Nicolás; Siccha-Ramirez, Raquel; Ron, Ernesto; Pérez, Julio Eduardo; Rossi, Anna Rita; Oliveira, Claudio

    2014-12-01

    The genus Pterois includes nine valid species, native to the Red Sea and Indian Ocean throughout the Western Pacific. P. volitans and P. miles are native to the Indo-Pacific, and were introduced into Florida waters as a result of aquarium releases, and have been recently recognized as invaders of the Western Atlantic and Caribbean Sea (Costa Rica to Venezuela). Thus far, cytogenetic studies of the genus Pterois only cover basic aspects of three species, including P. volitans from Indo-Pacific Ocean. Considering the lack of more detailed information about cytogenetic characteristics of this invasive species, the objective of the present study was to investigate the basic and molecular cytogenetic characteristics of P. volitans in Venezuela, and compare the results with those from the original distribution area. For this, the karyotypic characteristics of four lionfish caught in Margarita Island, Venezuela, were investigated by examining metaphase chromosomes by Giemsa staining, C-banding, Ag-NOR, and two-colour-Fluorescent in situ hybridization (FISH) for mapping of 18S and 5S ribosomal genes. Comparing the sequences of the 16S gene of the specimens analyzed, with sequences already included in the Genbank, we corroborated that our specimens identified as P. volitans are in fact this species, and hence exclude the possibility of a misidentification of P. miles. The diploid number was 2n = 48 (2m + 10sm + 36a) with FN = 60. Chromosomes uniformly decreased in size, making it difficult to clearly identify the homologues except for the only metacentric pair, and the pairs number two, the largest of the submetacentric series. C-banding revealed only three pairs of chromosomes negative for C-band, whereas all remaining chromosomes presented telomeric and some interstitial C-positive blocks. Only two chromosomes were C-banding positive at the pericentromeric regions. Sequential staining revealed Ag-NOR on the tips of the short arms of chromosome pair number two and the FISH assay revealed that 18S rDNA and 5S rDNA genes are co-located on this chromosome pair. The co-localization of 5S rDNA and 45S rDNA is discussed. Both constitutive heterochromatin and NOR location detected in samples examined in this study, differ from those reported for P. volitans in previous analysis of specimens collected in Indian Ocean (Java), suggesting the occurrence of chromosome microrearrangements involving heterochromatin during the spread of P. volitans. PMID:25720173

  20. A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species

    PubMed Central

    Maier, Crystal A.

    2013-01-01

    Abstract The species of the riffle beetle subfamily Larainae occurring in Venezuela are revised. Examination of 756 specimens yielded 22 species in nine genera occurring throughout the country. Seven species are newly recorded from the country: Phanoceroides sp. 1, Phanocerus clavicornis Sharp, 1882, Phanocerus congener Grouvelle, 1898, Pharceonus volcanus Spangler & Santiago-Fragoso, 1992, Disersus dasycolus Spangler & Santiago-Fragoso, 1992, Disersus chibcha Spangler & Santiago-Fragoso, 1987, and Disersus inca Spangler & Santiago-Fragoso, 1992. Nine species are found to be new to science, which are here described: Hexanchorus dentitibialis sp. n., H. falconensis sp. n., H. flintorum sp. n., H. homaeotarsoides sp. n., H. inflatus sp. n., Phanocerus rufus sp. n., Pharceonus grandis sp. n., Pharceonus ariasi sp. n., Potamophilops bostrychophallus sp. n. Additionally, a key to species, distribution maps, and photographs and genitalia illustrations are provided for all species. PMID:24146552

  1. Agaporomorphus sharynae, a new species of diving beetle (Coleoptera: Dytiscidae: Copelatinae) from Venezuela.

    PubMed

    Miller, Kelly B

    2014-01-01

    Agaporomorphus sharynae sp. n. is described from Amazonas, Venezuela. Agaporomorphus Zimmermann, 1921 now includes nine known species. The new species is part of the A. knishi species group since it has similarly convoluted male genitalia with rows of setae on the dorsal surface. Males can be separated from those of other members of the genus by the structure of the abdominal ventrites, shape of the antennae, and shape of the male median lobe. The cladistic analysis of K.B. Miller & Wheeler (2008) is modified to include the new species. The habitus and male and female genitalia are illustrated, and male genitalia of other species of the A. knishi species group are illustrated for comparison. PMID:24869866

  2. Methane production from mixed tropical savanna and forest vegetation in Venezuela

    NASA Astrophysics Data System (ADS)

    Crutzen, P. J.; Sanhueza, E.; Brenninkmeijer, C. A. M.

    2006-04-01

    Measurements of methane concentrations in the boundary layer in the northern part of the Guayana shield, Venezuela, during the wet season (October 1988), showed the presence of substantial methane surface emissions. The measuring site is within the savanna climate region, but is affected by emissions from savanna and forest vegetation. From day versus night concentration measurements, with higher concentrations during night, a methane source strength near the site of 3-7×1011 molecules/cm2/s can be estimated, which includes emissions from small tracts of flooded soils, termites and especially tropical vegetation. Extrapolated to the entire savanna, this may imply a methane source of ~30-60 Tg yr-1 similar to the one calculated for tropical vegetation on the basis of recently published in vitro plant emission experiments by Keppler et al. (2006), which indicate emissions of ~30 Tg yr-1 for tropical savannas and grasslands and ~78 Tg yr-1 for tropical forests.

  3. A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species

    E-print Network

    Maier, Crystal A.

    2013-09-05

    , University of Kansas, Lawrence, KS, 66045, USA † http://zoobank.org/E777AD0C-E27A-4C2A-B09E-37ACEA60F00C Corresponding author: Crystal A. Maier (cmaier@ku.edu) Academic editor: P. Bouchard | Received 4 March 2013 | Accepted 7 August 2013 | Published 5... September 2013 http://zoobank.org/0F944E1B-0FCE-47B8-B3E0-73C97A79CAAA Citation: Maier CA (2013) A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species. ZooKeys 329: 33–91. doi: 10.3897/zookeys.329.4961 Abstract...

  4. FIRST REPORT OF METALLO-?-LACTAMASES PRODUCING Enterobacter spp. STRAINS FROM VENEZUELA

    PubMed Central

    Martínez, Dianny; Rodulfo, Hectorina E.; Rodríguez, Lucy; Caña, Luisa E.; Medina, Belkis; Guzman, Militza; Carreño, Numirin; Marcano, Daniel; Donato, Marcos De

    2014-01-01

    Clinical strains of Enterobacter were isolated from Cumana's Central Hospital in Venezuela, and classified as E. cloacae (21), E. aerogenes (7), E. intermedium (1), E. sakazakii (1) and three unclassified. The strains showed high levels of resistance, especially to SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). This is the first report for South America of bla VIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacae showed bla TEM-1, but only one showed bla CTX-M-15 gene, while no bla SHV was detected. PMID:24553611

  5. Genetic diversity between and within the arenavirus species indigenous to western Venezuela

    PubMed Central

    Fulhorst, Charles F.; Cajimat, Maria N.B.; Milazzo, Mary Louise; Paredes, Hector; de Manzione, Nuris M. C.; Salas, Rosa A.; Rollin, Pierre E.; Ksiazek, Thomas G.

    2008-01-01

    The results of analyses of Z, RNA-dependent RNA polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that Guanarito virus was the most common cause of Venezuelan hemorrhagic fever in a 7-year period in the 1990’s and that the evolution of Pirital virus in association with Sigmodon alstoni (Alston’s cotton rat) has occurred at a significantly higher rate than the evolution of Guanarito virus in association with Zygodontomys brevicauda (short-tailed cane mouse) on the plains of western Venezuela. The results of analyses of the primary structures of the glycoproteins of the 8 strains of Guanarito virus isolated from humans suggested that these strains would be highly cross-reactive in neutralization assays. Thus, passive antibody therapy may prove beneficial in the treatment of human disease caused by strains of Guanarito virus that are enzootic in the region in which Venezuelan hemorrhagic fever is endemic. PMID:18586298

  6. CTX-M-14 ?-lactamase-producing Citrobacter freundii isolated in Venezuela

    PubMed Central

    2011-01-01

    A clinical isolate of C. freundii with reduced susceptibility to extended-spectrum ?-lactams from a woman with cystocele associated with recurrent urinary tract infection was analyzed. Susceptibility tests, double disk synergy tests (DDST) and enzymatic activity by the agar iodometric method suggested the presence of ESBLs. Conjugation experiments revealed the presence of a large conjugative plasmid (pLM07/20) with an exclusive FrepB replicon type (IncF/FIB). PCR analysis and sequencing confirmed the presence of the blaCTX-M-14 gene in the pLM07/20 from C. freundii.LM07/10. Although this is the first report of CTX-M-14 in Venezuela, we alert the medical community that future increase of these ?-lactamases in our city could be due to dissemination of plasmids into bacterial populations. PMID:21627834

  7. Nutrient content of earthworms consumed by Ye'Kuana Amerindians of the Alto Orinoco of Venezuela.

    PubMed Central

    Paoletti, M G; Buscardo, E; VanderJagt, D J; Pastuszyn, A; Pizzoferrato, L; Huang, Y-S; Chuang, L-T; Millson, M; Cerda, H; Torres, F; Glew, R H

    2003-01-01

    For the Makiritare (Ye'Kuana) native people of the Alto Orinoco (Venezuela), earthworms (Anellida: Glossoscolecidae) are an important component of the diet. Two species in particular are widely consumed: 'kuru' (Andiorrhinus kuru n. sp.) and 'motto' (Andiorrhinus motto). We analysed eviscerated kuru body proper, and whole and smoked preparations of motto for their content of protein and amino acids, fatty acids and 20 minerals and trace elements. The samples contained large amounts of protein (64.5-72.9% of dry weight), essential amino acids, calcium and iron together with notable quantities of other important elements, indicating that these earthworms contain potentially useful quantities of many nutrients that are critical to the health of the humans who consume them. PMID:12614573

  8. The Double-Astrograph Telescope is working at the Observatorio Astronómico Nacional of Venezuela

    NASA Astrophysics Data System (ADS)

    Abad, C.; Barroeta, G.; Schenner, H.; Plaza, L.; Ramírez, P.; Lacruz, E.

    2009-05-01

    The Double Astrograph telescope (two 0.5 m lenses) in the Observatorio Astronómico Nacional of Venezuela (OAN) will soon be available for observations to the astronomical comunity. Despite of being placed at the OAN since thirty years ago, together with the three other telescopes installed there, it was not fully assembled. Recent engineering work on it, has got to mecanically balance the telescope and set control of the electric motors for the motion of this instrument. The current positioning and guided motions of the telescope allow for an observational quantification of the different aberrations of the optical system of the instrument. With this in mind, selected fields of stars have been observed with a CCD camera, that was installed at different locations on the focal plane. Here we show a summary of the technical operations and the first observational results, aimed at evaluating the potential of the Double Astrograph for future scientific investigations.

  9. GPS-derived slip rates of active faults in eastern Venezuela, along the southeastern Caribbean PBZ

    NASA Astrophysics Data System (ADS)

    Audemard, F. A.; Beck, C.; Jouanne, F.; Reinoza, C. E.; Fegag

    2013-05-01

    For over 20 years, GPS campaign measurements have been performed in eastern Venezuela, as well as in other areas of the country, by different scientific groups and in the frame of different either national or international efforts and/or projects, essentially aiming at the estimation of the rate of motion along the major Quaternary faults (i.e., Boconó, San Sebastián and El Pilar faults) composing the plate boundary zone (PBZ) between the Caribbean and South America, along onshore northern and western Venezuela. The slip rates and sense of slip of those major faults derived from the comparison of several GPS campaigns carried out through the years have confirmed the slip data (fault kinematics) previously derived from geologic data, through comprehensive neotectonic and paleoseismic studies mainly made by the FUNVISIS' Earth Sciences Dpt. staff. In a rough way, we could conclude that those faults are dextrally moving at a rate in the order of 10-12 mm/a. More recently, it has been shown that the El Pilar fault has a locking depth close to 10 km deep and that about half of the PBZ dextral motion is accommodated as creep, reducing the seismic hazard for northeastern Venezuela almost by half. On the contrary, in the near past, very little attention has been paid to the secondary active faulting in eastern Venezuela. In that sense, FUNVISIS, in collaboration with the Université de Savoie, started the monitoring of these secondary features by installing 36 brass benchmarks on bedrock in that region in 2003, which have been occupied 3 times, in late 2003 and 2005 and in early 2013. The comparison between the 2003 and 2005 occupations shows promising results, such as: a) The Charagato fault on Cubagua island is left-lateral with a slip rate of about 2 mm/a; b) slip vectors across the El Pilar fault tend to head to the ESE, suggesting that the tectonic regime is compressive transcurrent to transcurrent compressional (transpressional); c) The NW-SE-trending San Francisco fault, in the eastern Interior range, appears to be dextral with a preliminary slip rate of few mm/a; d) the Northern Coast fault, paralleling the El Pilar fault, is also dextral and slips at about 2 mm/a and e) a similar situation seems to display the San Sebastián fault in the Gulf of Cariaco, north of Cumaná, near its eastern tip. We expect that the 2013 occupation, carried out over 9 years later than the first one, will allow estimating more accurately the slip rates of the slower subordinate active faults of the region. This is a contribution to cooperation projects FONACIT-ECOS Nord PI-2003000090 and -2009000818 (French codes V04U01 and V10U01, respectively), French DyETI Programme, as well as Venezuelan FONACIT 2002000478 (GEODINOS) and LOCTI (Cumaná and GIAME) projects. Michel Bechtold, Victor Cano, Luis Melo, Reinaldo Ollarves, Fabián Rada, José Antonio Rodríguez, Javier Sánchez and Aurelien Van Welden are contributing FEGAG members.

  10. Applied geointegration to hydrocarbon exploration in the San Pedro-Machango Area, Maracaibo Basin, Venezuela

    SciTech Connect

    Fonseca, A.; Navarro, A.; Osorio, R.; Corvo, F.; Arismendi, J.

    1996-08-01

    Hydrocarbon exploration has nowadays a diversity of technological resources to capture, merge and interpret information from diverse sources. To accomplish this, the integration of geodata for modeling was done through the use of new technologies like Remote Sensing and Geographical Systems of Information and applied to the San Pedro-Machango area, located in the Serrania de Trujillo, west of Costa Bolivar (onshore), eastern Maracaibo Basin, Venezuela. The main purpose of this work was to optimize the design of an exploration program in harmony with environmental conservation procedures. Starting with satellital and radar images that incorporated geophysical, geological and environmental information, they then were analyzed and merged to improve the lithological, structural and tectonic interpretation, generating an integrated model that allowed better project design. The use of a system that combines information of geographical, geodetical, geophysical and geological origins with satellital and radar images produced up to date cartography and refined results of image interpretation.

  11. AVO in North of Paria, Venezuela: Gas methane versus condensate reservoirs

    SciTech Connect

    Regueiro, J.; Pena, A.

    1996-07-01

    The gas fields of North of Paria, offshore eastern Venezuela, present a unique opportunity for amplitude variations with offset (AVO) characterization of reservoirs containing different fluids: gas-condensate, gas (methane) and water (brine). AVO studies for two of the wells in the area, one with gas-condensate and the other with gas (methane) saturated reservoirs, show interesting results. Water sands and a fluid contact (condensate-water) are present in one of these wells, thus providing a control point on brine-saturated properties. The reservoirs in the second well consist of sands highly saturated with methane. Clear differences in AVO response exist between hydrocarbon-saturated reservoirs and those containing brine. However, it is also interesting that subtle but noticeable differences can be interpreted between condensate-and methane-saturated sands. These differences are attributed to differences in both in-situ fluid density and compressibility, and rock frame properties.

  12. Reliability as the big persuader to privatize the electrical system in Venezuela

    SciTech Connect

    Alvarez B., C.E.

    1998-12-31

    Throughout the past five years, the Venezuelan authorities, especially the Fondo de Inversiones de Venezuela (FIV), have done a major effort to privatize many of the state owned industries, among them, the electrical public utilities and some important electrical power generation plants or systems based on thermal generation. Mainly along the recent past years, black and brownouts have become more frequent in the system. In other words, system reliability has been diminishing, as a consequence of investment capital and O and M expenses have been reduced to levels below the required by the system. Public opinion is exercising pressure on politicians, so signals are that Congress will probably approve during the current or beginning of next years the required laws to expedite privatization and assure incentives and guaranties to investors. This paper deals with the insides of all these aspects, and with how soon privatization will be carried out. The FIV has been committed to implement this process.

  13. Methodology to incorporate EIA in land-use ordering -- case study: The Cataniapo River basin, Venezuela

    SciTech Connect

    Sebastiani, M.; Llambi, L.D.; Marquez, E.

    1998-07-01

    In Venezuela, the idea of tiering information between land-use ordering instruments and impact assessment is absent. In this article the authors explore a methodological alternative to bridge the information presented in land-use ordering instruments with the information requirements for impact assessment. The methodology is based on the steps carried out for an environmental impact assessment as well as on those considered to develop land-use ordering instruments. The methodology is applied to the territorial ordering plan and its proposal for the protection zone of the Cataniapo River basin. The purpose of the protection zone is to preserve the water quality and quantity of the river basin for human consumption.

  14. Management of a giant deep field: El Furrial Field, Eastern Venezuela

    SciTech Connect

    Pinto, N.; Mengual, R.; Anz, J.; Rodney, C.

    1996-08-01

    The Furrial Field is located in Eastern Venezuela and produces a 25 to 30{degrees} API asphaltenic crude oil from a 1500 ft thick Oligocene sand interval at a depth of 15,000 ft. The bubble point is about 4500 psi as compared to an original pressure of 11,000 psi. Oil in place is approximately 6800 million STB. Currently production is 350 MB/D from 77 well streams (Naricual Formation), and water is being injected at 400 MB/D to maintain pressure. The combination of a volumetric reservoir and asphaltenic nature of crude oil resulted in a rapid decrease in well productivity and reservoir pressure, creating the necessity to maintain reservoir pressure to maximize recovery. Discussed in this paper are the reservoir management techniques and strategies used by Lagoven to develop and operate these complex reservoirs. Acquisition and analysis of these data adequate to properly implement these management techniques are covered in detail.

  15. Training Hybrid Neuro-Fuzzy System to Infer Permeability in Wells on Maracaibo Lake, Venezuela

    E-print Network

    Hurtado, Nuri; Torres, Julio

    2014-01-01

    The high accuracy on inferrring of rocks properties, such as permeability ($k$), is a very useful study in the analysis of wells. This has led to development and use of empirical equations like Tixier, Timur, among others. In order to improve the inference of permeability we used a hybrid Neuro-Fuzzy System (NFS). The NFS allowed us to infer permeability of well, from data of porosity ($\\phi$) and water saturation ($Sw$). The work was performed with data from wells VCL-1021 (P21) and VCL-950 (P50), Block III, Maracaibo Lake, Venezuela. We evaluated the NFS equations ($k_{P50,i}(\\phi_i,Sw_i)$) with neighboring well data ($P21$), in order to verify the validity of the equations in the area. We have used ANFIS in MatLab.

  16. [Physical properties of the agar of Gracilariopsis tenuifrons (Gracilariacea) from Sucre, Venezuela].

    PubMed

    Zecchinel, E; Brito, L; Lárez, G

    2000-12-01

    The yield, gel strength, gelling and melting temperatures of Gracilariopsis tenuifrons agar from Guayacán, Araya Peninsula, Sucre State, Venezuela were determined. Yield values with and without alkali treatment ranged from 23.22 to 39.57% and from 16.29 to 22.42% respectively, while gel strength with alkali treatment fluctuated betwen 699.31 and 1231.69 g/cm2 and without treatment varied from 278.0 to 691.06 g/cm2. Gelling and melting temperatures were in the range reported for other agarophytes. Considering gel strength, the agar quality of G. tenuifrons was higher than in other species and its exploitation in economically feasible. PMID:15266808

  17. Altitude determination and descriptive analysis of clouds on ERTS-1 multispectral photography. [Venezuela

    NASA Technical Reports Server (NTRS)

    Albrizzio, C.; Andressen, A.

    1974-01-01

    A simple method to determine the approximate altitude of clouds is described, with the objective of refining their classification using only marginal data from the photographs. Results of the application of this method on photographs of the Goajira Peninsula, Paraguana Peninsula and the Central Coast of Venezuela are presented. Here, the altitudes computed are used to classify clouds and to identify the genus of others without typical form. Instability of air masses through clouds vertical development, and wind direction as well as other local climatic characteristics such as moisture content, loci of condensation, area, etc. are determined using repetitive coverage for the time interval of the photography. Applications for the regional and urban planning (including airport location and flights schedule) and natural resources evaluation are suggested.

  18. Trypanosoma cruzi, the Causal Agent of Chagas Disease: Boundaries between Wild and Domestic Cycles in Venezuela

    PubMed Central

    Herrera, Leidi

    2014-01-01

    Trypanosoma cruzi the etiological agent of American Trypanosomiasis or Chagas disease (ChD) is transmitted by triatomines vectors between mammals including man. T. cruzi has existed for circa 150?Ma in the Americas and nearly 10 million people are currently infected. The overlap between wild and domestic ecotopes where T. cruzi circulates is increasing. Host–parasite interactions have been determined by infection patterns in these cycles, all under natural or laboratorial conditions. This mini-review describes specific parasite niches, such as plant communities or biological corridors between domestic and wild landscapes, in order to help identify risk factors for ChD and define the boundaries between wild and domestic transmission cycles, with an emphasis on research undertaken in Venezuela. PMID:25506587

  19. The Cerro Negro accumulation of Venezuela's Orinoco Belt - the favorable convergence of several geological processes

    SciTech Connect

    Swanson, D.C. ); Tarache, C. )

    1993-02-01

    The Cerro Negro Area is a major part of eastern Venezuela's Orinoco Belt. Here upper Eocene fluvial-deltaic deposits of the Oficina Fm. reservoir billions of barrels of heavy oil, much of which is in valley-fill deposits. Maturation, migration and accumulation of these hydrocarbons in thick, porous and permeable sandstones were the logical conclusion to several major geological events in eastern Venezuela during the Tertiary. In the Cerro Negro Area, Cretaceous clastics were deposited on an igneous and metamorphic basement after which the sea withdrew northward toward the axial part of the Eastern Venezuelan Basin. The basement and Cretaceous deposits were weathered and eroded during the Eocene, Oligocene, and early Miocene, forming the unconformity on which the Oficina Fm. is deposited. Historic reconstruction begins with this unconformity, a paleotopographic surface strongly influencing the character and distribution of the overlying Oficina Fm. As relative sea level fell and gradients increased, streams incised into the shelf while transporting great amounts of coarse clastic load northward. At Cerro Negro, a mature topography of low ridges and hills were developed with differential elevations of several hundred feet. During the Miocene, a sea transgressed across the stream-etched unconformity. Streams carrying large amounts of clastic load encountered an elevating sea level. They consequently dropped their coarse load, forming long, linear, transgressive, valley-fill deposits. By Late Miocene, hydrocarbons generated in the deeper basin began to migrate southward through the long linear fluvial-deltaic clastic conduits that were separated laterally and vertically into complex [open quotes]plumbing systems.[close quotes] As the hydrocarbons moved shelfward, normal faults cut the conduits into numerous reservoir segments. The timing between migration and faulting is critical to present-day hydrocarbon distribution in these segments.

  20. Eastern Venezuela Basin's Post-Jurassic evolution as a passive transform margin basin

    SciTech Connect

    George, R.P. Jr. ); Sams, R.H. )

    1993-02-01

    Passive transform margins are segments of rifted continental margins bounded by transform faults that are active during rifting and that become inactive during drifting. Examples include the northern coast of Brazil and its matching margin along the Liberia-Nigeria coast. We propose that the northern margin of the Eastern Venezuela Basin was dominantly a passive transform margin during the Cretaceous and early Paleogene, rather than a purely passive margin. Published microplate reconstructions of the southern Caribbean show Jurassic separation of the Bahamas platform from northern South America along a northwest-trending transform fault postulated to lie just northeast of Trinidad and the Guianas. We conjecture that the [open quotes]Deflexion de Barcelona[close quotes] (a northwest-trending zone of strike slip faults along the southwestern edge of the Serrania del Interior) is controlled by a basement geofracture that is the onshore expression of Jurassic transform fault southwest of and subparallel to the southwestern Bahamas transform. Implications of this conjecture for the Eastern Venezuela Basin include: (1) absence of McKenzie-type regional crustal stretching, Mesozoic thermal anomaly, and Mesozoic thermal-tectonic subsidence; (2) abrupt rather than gradual seaward changes in crustal thickness; (3)abrupt lateral changes in thickness and facies of Mesozoic sediments, as in the Piaui-Ceara basins of northern Brazil; (4) tendency for structural styles developed during Neogene compression to include more strike-slip faults and en enchelon fold sets (because of reactivation of Mesozoic transforms) than would be expected by structural inversion of a purely passive margin.

  1. Evidence of at Least Two Introductions of HIV-1 in the Amerindian Warao Population from Venezuela

    PubMed Central

    Rangel, Héctor R.; Maes, Mailis; Villalba, Julian; Sulbarán, Yoneira; de Waard, Jacobus H.; Bello, Gonzalo; Pujol, Flor H.

    2012-01-01

    Background The Venezuelan Amerindians were, until recently, free of human immunodeficiency virus (HIV) infection. However, in 2007, HIV-1 infection was detected for the first time in the Warao Amerindian population living in the Eastern part of Venezuela, in the delta of the Orinoco river. The aim of this study was to analyze the genetic diversity of the HIV-1 circulating in this population. Methodology/Principal Findings The pol genomic region was sequenced for 16 HIV-1 isolates and for some of them, sequences from env, vif and nef genomic regions were obtained. All HIV-1 isolates were classified as subtype B, with exception of one that was classified as subtype C. The 15 subtype B isolates exhibited a high degree of genetic similarity and formed a highly supported monophyletic cluster in each genomic region analyzed. Evolutionary analyses of the pol genomic region indicated that the date of the most recent common ancestor of the Waraos subtype B clade dates back to the late 1990s. Conclusions/Significance At least two independent introductions of HIV-1 have occurred in the Warao Amerindians from Venezuela. The HIV-1 subtype B was successfully established and got disseminated in the community, while no evidence of local dissemination of the HIV-1 subtype C was detected in this study. These results warrant further surveys to evaluate the burden of this disease, which can be particularly devastating in this Amerindian population, with a high prevalence of tuberculosis, hepatitis B, among other infectious diseases, and with limited access to primary health care. PMID:22808212

  2. Mantle flow beneath northwestern Venezuela: Seismic evidence for a deep origin of the Mérida Andes

    NASA Astrophysics Data System (ADS)

    Masy, Jeniffer; Niu, Fenglin; Levander, Alan; Schmitz, Michael

    2011-05-01

    We measured shear wave splitting from SKS data recorded by the national seismic network of Venezuela and a linear broadband PASSCAL/Rice seismic array across the Mérida Andes. The linear array was installed in the second phase of the passive seismic component of the BOLIVAR project to better understand the complicated regional tectonics in western Venezuela. Using the method proposed by Wolfe and Silver (1998), SKS waveforms from 2 to 36 earthquakes, mostly from the Tonga subduction zone, were selected for each of the 23 stations in the region in order to do splitting analysis. The fast polarization directions can be divided into 3 zones, all in agreement with local GPS data: The first zone comprises the stations north of the dextral strike-slip Oca-Ancon fault. These stations show the largest split times (1.6-3.2 s), oriented in a roughly EW direction, and are similar to splitting observations made further to the east along the strike slip plate boundary (Growdon et al., 2009). We attribute this to trench-parallel mantle flow that passes around the northwest corner of the subducting Caribbean plate and along the northern edge of South America as proposed by Russo and Silver (1994), forming an eastward flow beneath the southern Caribbean plate. Zone two is the Mérida Andes, with the right lateral Bocono fault in the center, where split orientations are at ~ N45°E, suggesting that the observed seismic anisotropy is likely caused by lithospheric deformation parallel to the Bocono fault. Zone three is east of the Bocono fault inside the Barinas-Apure Basin, where the measured split times are smaller (~ 0.8 s) with an EW fast direction that is consistent with those observed at the Guarico Basin, Maturin Basin and the Guayana Shield in the east, and are interpreted as orientation with the motion of the continent.

  3. [FOOD CONSUMPTION PATTERN AT A FAMILY LEVEL OF URBAN AREAS OF ANZOÁTEGUI, VENEZUELA].

    PubMed

    Ekmeiro Salvador, Jesús; Moreno Rojas, Rafael; García Lorenzo, María; Cámara Martos, Fernando

    2015-01-01

    In order to assess the qualitative pattern of food consumption in urban families of Anzoátegui, Venezuela, 300 domestic groups that combined a total of 1 163 people were studied. The domestic dietary pattern was addressed by the method of qualitative frequency of food consumption, which applied a structured survey that yielded the usual frequency of intake of a food or food group over a given period. The information was obtained through an interview with the person responsible for the procurement of food in every home, and included basic data for the socioeconomic and nutritional profile of the families studied. The qualitative analysis of the diet was obtained by comparing the different food groups that constitute the actual consumption pattern of the population studied, with official feeding guidelines suggested for the Venezuelan population. The present study showed that the qualitative pattern of food consumption in the urban population evaluated is characterized by slightly adjusted to the promotion of health and control of diet-related diseases. The family food proved to be far from the guidelines established by the dietary guidelines for Venezuela and consumption patterns are fairly homogeneous in the different socioeconomic strata. The foods most consumed daily were salt, coffee, dressing and precooked corn flour as well as beef, chicken and the higher weekly food consumption pastas. 90% of the food consumed daily is technologically processed. The results contribute to increase knowledge about the food situation of the Venezuelan population, and technically could direct the efforts of the authorities to reconcile the development of the productive sector and food supply, whereas a pattern qualitatively inadequate intake directly affects the individual biological functioning, and results in the collective conditioning of unfavorable health states. PMID:26545547

  4. [Psychological resistance to use insulin in type 2 diabetes mellitus patients from Venezuela].

    PubMed

    González Rivas, Juan Pablo; Paoli, Mariela; García Santiago, Raúl; Verónica Avendaño, María; Lobo Santiago, Merlys; Avendaño, Andrea

    2014-09-01

    The psychological resistance to use insulin (PIR) is a condition where the patient with type 2 diabetes mellitus (T2DM) refuses to use insulin. Our objective was to determine the frequency of PIR in a Venezuelan population and their beliefs regarding insulin and current medication. In several states of Venezuela, from January to March 2013, 254 patients with T2DM, over 18 years old and naive to insulin treatment were interviewed. We applied an interview to evaluate the disposition of the patients to use insulin if their doctor prescribes it and to determine their beliefs about insulin and their current medication. The patients were categorized in: not willing (PIR group), ambivalent and willing to use insulin. The beliefs about insulin and their current medication were grouped into positive or negative. The mean age was 56.2 years, with 7.1 years of duration of the T2DM; 58.6% were females. One third (32.7%) had PIR, 20.9% were ambivalent and 46.4% were willing to use insulin. PIR patients showed lower frequency of positive beliefs and more frequency of negative beliefs to insulin and to their current treatment (p < 0.0001). Negative beliefs to insulin increased 14 times the risk of PIR, and people without university studies had a four times increase in the risk of PIR compared to the willing group. In conclusion, a high frequency of PIR in patients with T2DM (32.7%) was found in Venezuela; they showed low frequency of positive beliefs and high frequency of negative beliefs about insulin use. It is necessary to improve T2DM patient education on this issue. PMID:25272521

  5. [Superficial mycoses in patients from Anzoátegui state, Venezuela, period 2002-2012].

    PubMed

    Lemus-Espinoza, Druvic; Teresa Maniscalchi, María; Villarroel, Oskarina; Bónoli, Stefano B; Wahab, Fadi; García, Oswaldo

    2014-12-01

    Superficial fungal diseases that affect the skin and its appendages are frequently seen in basic triage and in dermatology services. These diseases are distributed in Venezuela with an incidence of 92.9%. The aim of this study was to determine the genera and species that cause dermatomycoses in residents of Anzoátegui state, Venezuela, during the period 2002-2012. A total of 4257 patients with a presumptive diagnosis of superficial mycoses were studied, with ages from 7 months to 79 years. The overall prevalence was 30.9%. The most frequent were dermatophytosis (44.7%). M. canis produced 148 cases of tinea capitis. Three dermatophytic agents represented 95% of all cases, with a significant predominance of T. mentagrophytes with 50%. Candidosis occurred in 28.4%. C. albicans, and the C. parapsilosis complex, were responsible for 80% of the cases. The other species identified were C. tropicalis (n = 41, 11.0%), C. glabrata (n = 10, 2.7%), C. guilliermondii (n = 6, 1.6%), C. krusei (n = 4, 1.1%). Pityriasis versicolor occurred in 22.4% of the cases studied, and less frequently were present onychomycosis produced by a non dermatophytic mold: Fusarium oxysporum (n = 34, 65.4%), Aspergillus terreus (n=16, 30.8%) and Scytalidium dimidiatum (n=2; 3.8%). Rare cases of Trichosporon onychomycosis (0.5%) and one case of black tinea were also found. Health education in the population is recommended to promote measures to prevent transmission of these fungi and prevent the spread of this silent public health problem. PMID:25558751

  6. Integrated foraminiferal biostratigraphy and chemostratigraphy of the querecual formation (Cretaceous), Eastern Venezuela

    USGS Publications Warehouse

    Crespo De Cabrera, S.; Sliter, W.V.; Jarvis, I.

    1999-01-01

    An integrated foraminiferal biostratigraphy and chemostratigraphy is presented for the Lower to Upper Cretaceous Querecual Formation exposed on Chimana Grande Island, Eastern Venezuela. The formation consists of >450 m alternating foraminiferal and organic-rich carbonates and laminated mudrocks, and is considered the main hydrocarbon source rock for the eastern Venezuela Basin. Biostratigraphic resolution within the Querecual Formation is poor, due to a paucity of keeled planktonic foraminifera and impoverished benthic faunas. Deposition occurred in a bathyal environment, with dysaerobic or anoxic bottom waters resulting from high rates of surface productivity associated with an upwelling environment. Biostratigraphic evidence indicates that the Querecual Formation ranges from the upper Albian Rotalipora ticinensis Zone to the Santonian Dicarinella asymetrica Zone. Iron and Al contents fall through the Albian-Cenomanian indicating a progressive decrease in the detrital supply, driven by rising eustatic sea level. A Ca profile demonstrates variations in carbonate production and dissolution. High total organic carbon (TOC) intervals occur in the upper Albian to mid-Cenomanian and Turonian, and high Ba/Al and Si/Al ratios characterize mid-Cenomanian and younger sediments. Variations in these elements primarily reflect changes in marine productivity, but are also affected by diagenetic processes. A stable carbon isotope curve established from analysis of organic matter (??13Corg) correlates well with published ??13C curves for carbonates from England and Italy. The Cenomanian/Turonian boundary cannot be identified using planktonic foraminifera, because key taxa are absent, but the base of the Turonian is clearly indicated by a sharp fall in ??13C immediately above a major positive excursion. The bottom of the Coniacian is placed below a ??13C minimum, towards the base of the Dicarinella concavata Zone. Combined with the foraminiferal data, the isotopic data enable much improved stratigraphic resolution compared to previous investigations of the formation.

  7. Common Distribution Patterns of Marsupials Related to Physiographical Diversity in Venezuela

    PubMed Central

    Ventura, Jacint; Bagaria, Guillem; Sans-Fuentes, Maria Assumpció; Pérez-Hernández, Roger

    2014-01-01

    The aim of this study is to identify significant biotic regions (groups of areas with similar biotas) and biotic elements (groups of taxa with similar distributions) for the marsupial fauna in a part of northern South America using physiographical areas as Operational Geographical Units (OGUs). We considered Venezuela a good model to elucidate this issue because of its high diversity in landscapes and the relatively vast amount of information available on the geographical distribution of marsupial species. Based on the presence-absence of 33 species in 15 physiographical sub-regions (OGUs) we identified Operational Biogeographical Units (OBUs) and chorotypes using a quantitative analysis that tested statistical significance of the resulting groups. Altitudinal and/or climatic trends in the OBUs and chorotypes were studied using a redundancy analysis. The classification method revealed four OBUs. Strong biotic boundaries separated: i) the xerophytic zone of the Continental coast (OBU I); ii) the sub-regions north of the Orinoco River (OBU III and IV); and those south to the river (OBU II). Eleven chorotypes were identified, four of which included a single species with a restricted geographic distribution. As for the other chorotypes, three main common distribution patterns have been inferred: i) species from the Llanos and/or distributed south of the Orinoco River; ii) species exclusively from the Andes; and iii) species that either occur exclusively north of the Orinoco River or that show a wide distribution throughout Venezuela. Mean altitude, evapotranspiration and precipitation of the driest month, and temperature range allowed us to characterize environmentally most of the OBUs and chorotypes obtained. PMID:24806452

  8. Molecular epidemiology suggests Venezuela as the origin of the dengue outbreak in Madeira, Portugal in 2012-2013.

    PubMed

    Franco, L; Pagan, I; Serre Del Cor, N; Schunk, M; Neumayr, A; Molero, F; Potente, A; Hatz, C; Wilder-Smith, A; Sánchez-Seco, M P; Tenorio, A

    2015-07-01

    An explosive epidemic occurred in Madeira Island (Portugal) from October 2012 to February 2013. Published data showed that dengue virus type 1 introduced from South America was the incriminated virus. We aim to determine the origin of the strain introduced to Madeira by travellers returning to Europe. Using phylogeographic analysis and complete envelope sequences we have demonstrated that the most probable origin of the strain is Venezuela. PMID:25843502

  9. Genetic History of Hepatitis C Virus in Venezuela: High Diversity and Long Time of Evolution of HCV Genotype 2

    PubMed Central

    Sulbarán, Maria Z.; Di Lello, Federico A.; Sulbarán, Yoneira; Cosson, Clarisa; Loureiro, Carmen L.; Rangel, Héctor R.; Cantaloube, Jean F.; Campos, Rodolfo H.; Moratorio, Gonzalo; Cristina, Juan; Pujol, Flor H.

    2010-01-01

    Background The subtype diversity of the hepatitis C virus (HCV) genotypes is unknown in Venezuela. Methodology/Principal Findings Partial sequencing of the NS5B region was performed in 310 isolates circulating in patients from 1995 to 2007. In the samples collected between 2005 and 2007, HCV genotype 1 (G1) was the most common genotype (63%), composed as expected of mainly G1a and G1b. G2 was the second most common genotype (33%), being G2a almost absent and G2j the most frequent subtype. Sequence analysis of the core region confirmed the subtype assignment performed within the NS5b region in 63 isolates. The complete genome sequence of G2j was obtained. G2j has been described in France, Canada and Burkina Fasso, but it was not found in Martinique, where several subtypes of G2 circulate in the general population. Bayesian coalescence analysis indicated a most recent common ancestor (MRCA) of G2j around 1785, before the introduction of G1b (1869) and G1a (1922). While HCV G1a and G1b experienced a growth reduction since 1990, coincident with the time when blood testing was implemented in Venezuela, HCV G2j did not seem to reach growth equilibrium during this period. Conclusions/Significance Assuming the introduction of G2j from Africa during the slave trade, the high frequency of G2j found in Venezuela could suggest: 1- the introduction of African ethnic groups different from the ones introduced to Martinique or 2- the occurrence of a founder effect. This study represents an in-depth analysis of the subtype diversity of HCV in Venezuela, which is still unexplored in the Americas and deserves further studies. PMID:21179440

  10. Molecular characterisation of Mycobacterium tuberculosis isolates in the First National Survey of Anti-tuberculosis Drug Resistance from Venezuela

    PubMed Central

    Aristimuño, Liselotte; Armengol, Raimond; Cebollada, Alberto; España, Mercedes; Guilarte, Alexis; Lafoz, Carmen; Lezcano, María A; Revillo, María J; Martín, Carlos; Ramírez, Carmen; Rastogi, Nalin; Rojas, Janet; de Salas, Albina Vázques; Sola, Christophe; Samper, Sofía

    2006-01-01

    Background Molecular typing of Mycobacterium tuberculosis strains has become a valuable tool in the epidemiology of tuberculosis (TB) by allowing detection of outbreaks, tracking of epidemics, identification of genotypes and transmission events among patients who would have remained undetected by conventional contact investigation. This is the first genetic biodiversity study of M. tuberculosis in Venezuela. Thus, we investigated the genetic patterns of strains isolated in the first survey of anti-tuberculosis drug-resistance realised as part of the Global Project of Anti-tuberculosis Drug Resistance Surveillance (WHO/IUATLD). Results Clinical isolates (670/873) were genotyped by spoligotyping. The results were compared with the international spoligotyping database (SpolDB4). Multidrug resistant (MDR) strains (14/18) were also analysed by IS6110-RFLP assays, and resistance to isoniazid and rifampicin was characterised. Spoligotyping grouped 82% (548/670) of the strains into 59 clusters. Twenty new spoligotypes (SITs) specific to Venezuela were identified. Eight new inter-regional clusters were created. The Beijing genotype was not found. The genetic network shows that the Latin American and Mediterranean family constitutes the backbone of the genetic TB population-structure in Venezuela, responsible of >60% of total TB cases studied. MDR was 0.5% in never treated patients and 13.5% in previously treated patients. Mutations in rpoB gene and katG genes were detected in 64% and 43% of the MDR strains, respectively. Two clusters were found to be identical by the four different analysis methods, presumably representing cases of recent transmission of MDR tuberculosis. Conclusion This study gives a first overview of the M. tuberculosis strains circulating in Venezuela during the first survey of anti-tuberculosis drug-resistance. It may aid in the creation of a national database that will be a valuable support for further studies. PMID:17032442

  11. Population structure of the dengue viruses, Aragua, Venezuela, 2006–2007. Insights into dengue evolution under hyperendemic transmission

    PubMed Central

    Rodriguez-Roche, Rosmari; Villegas, Elci; Cook, Shelley; Poh Kim, Pauline A.W.; Hinojosa, Yoandri; Rosario, Delfina; Villalobos, Iris; Bendezu, Herminia; Hibberd, Martin L.; Guzman, Maria G.

    2012-01-01

    During the past three decades there has been a notable increase in dengue disease severity in Venezuela. Nevertheless, the population structure of the viruses being transmitted in this country is not well understood. Here, we present a molecular epidemiological study on dengue viruses (DENV) circulating in Aragua State, Venezuela during 2006–2007. Twenty-one DENV full-length genomes representing all of the four serotypes were amplified and sequenced directly from the serum samples. Notably, only DENV-2 was associated with severe disease. Phylogenetic trees constructed using Bayesian methods indicated that only one genotype was circulating for each serotype. However, extensive viral genetic diversity was found in DENV isolated from the same area during the same period, indicating significant in situ evolution since the introduction of these genotypes. Collectively, the results suggest that the non-structural (NS) proteins may play an important role in DENV evolution, particularly NS1, NS2A and NS4B proteins. The phylogenetic data provide evidence to suggest that multiple introductions of DENV have occurred from the Latin American region into Venezuela and vice versa. The implications of the significant viral genetic diversity generated during hyperendemic transmission, particularly in NS protein are discussed and considered in the context of future development and use of human monoclonal antibodies as antivirals and tetravalent vaccines. PMID:22197765

  12. Global Climate Change Effects on Venezuela's Vulnerability to Chagas Disease is Linked to the Geographic Distribution of Five Triatomine Species.

    PubMed

    Ceccarelli, Soledad; Rabinovich, Jorge E

    2015-11-01

    We analyzed the possible effects of global climate change on the potential geographic distribution in Venezuela of five species of triatomines (Eratyrus mucronatus (Stal, 1859), Panstrongylus geniculatus (Latreille, 1811), Rhodnius prolixus (Stål, 1859), Rhodnius robustus (Larrousse, 1927), and Triatoma maculata (Erichson, 1848)), vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. To obtain the future potential geographic distributions, expressed as climatic niche suitability, we modeled the presences of these species using two IPCC (Intergovernmental Panel on Climate Change) future emission scenarios of global climate change (A1B and B1), the Global Climate model CSIRO Mark 3.0, and three periods of future projections (years 2020, 2060, and 2080). After estimating with the MaxEnt software the future climatic niche suitability for each species, scenario, and period of future projections, we estimated a series of indexes of Venezuela's vulnerability at the county, state, and country level, measured as the number of people exposed due to the changes in the geographical distribution of the five triatomine species analyzed. Despite that this is not a measure of the risk of Chagas disease transmission, we conclude that possible future effects of global climate change on the Venezuelan population vulnerability show a slightly decreasing trend, even taking into account future population growth; we can expect fewer locations in Venezuela where an average Venezuelan citizen would be exposed to triatomines in the next 50-70 yr. PMID:26336258

  13. Universidad Simn Bolvar, Edif. Energtica, Planta Baja. Valle de Sartenejas, Baruta, Caracas, Edo. Miranda, Venezuela, 89000 Telef.: 58 212 906-3708 / 3709 / 3710 / 3711 Fax: 58 212 906-3712 www.ulab.usb.ve

    E-print Network

    Vásquez, Carlos

    . Miranda, Venezuela, 89000 Telef.: 58 212 906-3708 / 3709 / 3710 / 3711 Fax: 58 212 906-3712 www siguiente: Universidad Simón Bolívar Valle de Sartenejas Baruta; Edo. Miranda, 1080 Venezuela Cód. Doc.: UL

  14. Population structure of guppies in north-eastern Venezuela, the area of putative incipient speciation

    PubMed Central

    2014-01-01

    Background Geographic barriers to gene flow and divergence among populations in sexual traits are two important causes of genetic isolation which may lead to speciation. Genetic isolation may be facilitated if these two mechanisms act synergistically. The guppy from the Cumaná region (within the Cariaco drainage) of eastern Venezuela has been previously described as a case of incipient speciation driven by sexual selection, significantly differentiated in sexual colouration and body shape from the common guppy, Poecilia reticulata. The latter occurs widely in northern Venezuela, including the south-eastern side of Cordillera de la Costa, where it inhabits streams belonging to the San Juan drainage. Here, we present molecular and morphological analyses of differentiation among guppy populations in the Cariaco and San Juan drainages. Our analyses are based on a 953 bp long mtDNA fragment, a set of 15 microsatellites (519 fish from 20 populations), and four phenotypic traits. Results Both microsatellite and mtDNA data showed that guppies inhabiting the two drainages are characterised by a significant genetic differentiation, but a higher proportion of the genetic variance was distributed among populations within regions. Most guppies in the Cariaco drainage had mtDNA from a distinct lineage, but we also found evidence for widespread introgression of mtDNA from the San Juan drainage into the Cariaco drainage. Phenotypically, populations in the two regions differed significantly only in the number of black crescents. Phenotypic clustering did not support existence of two distinct groupings, but indicated a degree of distinctiveness of Central Cumaná (CC) population. However, CC population showed little differentiation at the neutral markers from the proximate populations within the Cariaco drainage. Conclusions Our findings are consistent with only partial genetic isolation between the two geographic regions and indicate that the geographic barrier of Cordillera de la Costa has not played an important role in strengthening the incomplete pre-zygotic reproductive barrier between Cumaná and common guppy. Significant phenotypic differentiation between genetically similar (in terms of neutral variation) populations suggests that mate choice can maintain divergence at sexually selected traits despite gene flow. However, neither genetic nor phenotypic clustering supported delineation of two species within the region. PMID:24533965

  15. Variability of coastal suprabenthic assemblages from sandy beaches of the Caribbean coast of Venezuela.

    PubMed

    Ortega, Ileana; Martín, Alberto; Díaz, Yusbelly J

    2014-06-01

    The suprabenthos or hyperbenthos is the macrofaunal assemblage of small-sized organisms that interact for some time in the benthic boundary layer. Information about the taxonomic composition and role of suprabenthic species, especially in littoral zones, is scarce and scattered. This work attempts to contribute alleviate this problem. We analyze the temporal and spatial variations of suprabenthic assemblages in the swash-zone from four beaches of the littoral coast of Venezuela. For each beach, two sites were chosen, and special attention was given to water and sediment characteristics. 12 environmental variables were measured: Dissolved oxygen, oxygen saturation percentage, pH, salinity, surface temperature, total, organic and inorganic suspended solids, total organic carbon, organic matter in sediment, grain size of sediment, and amount of dragged material of sample. All faunal samples were taken on a monthly basis during 2011; these were extracted using a manual suprabenthic sledge towed parallel to the shoreline. Samples were sorted and identified to their lowest possible taxonomic level. A total of 24 141 specimens (mean abundance: 26.16 +/- 55.35 ind./m2) belonging to 21 taxonomic groups were identified. Analysis suggests that seasonality does not explain observed changes either in fauna or environmental variables. It was found that suprabenthic assemblages, total suprabenthos density, richness and environmental variables changed in a dissimilar fashion between months and beaches. The most frequent groups were amphipods and decapods; and at the species/categories level post-larval shrimp (Penaeidae), Grapsidae crab megalopae and Arenaeus cribarius megalopae were common. Dissimilarity between months in each beach was primarily explained by the abundance of amphipods, ctenophores, decapods and mysids. For particular months and selected beaches very high abundances of ctenophores were found. This group dominated the sample even though it is not usually a representative group in suprabenthos. Samples showed low correlations between suprabenthos and environmental variables. A somewhat stronger correlation could be established between water characteristics and dragged material abundance. The studied suprabenthos assemblage was found to have high taxa richness and very dynamic behaviour at spatial and temporal scale. Further analysis suggested that there is no evident pattern of distribution and that causality can not be directly attributed to temporal variation only. Possibly there is an influence of a synergy of environmentals or biological factors, rather than a single variable. The species Americamysis bahia and Americamysis taironana are reported for the first time in Venezuela. This study represents the first ecological research of the suprabenthos in the Caribbean region. PMID:25102634

  16. Tectonic implications of Paleocene-Eocene Foreland Basin, Lake Maracaibo, Venezuela

    SciTech Connect

    Lugo, J. ); Mann, P. )

    1993-02-01

    A compilation of industry geological and geophysical data indicates that Paleocene-Eocene clastic sedimentation in the Maracaibo basin records the first manifestation of Cenozoic foreland basin tectonics in northern South America. Isopach maps based on industry seismic data and well logs suggest that the Maracaibo foreland basin formed a 100 to 200 km wide elongate trough along the northeastern edge of the present-day Lake Maracaibo. The basin is asymmetric with a deep (7 km) northeastern margin adjacent to an exposed southwest-verging thrust belt mapped by previous workers. Isopach mapping of seven seismic units within the Eocene suggest a nor-northwest to southeast migration of the depocenter from Paleocene to Middle Eocene time at a rate of 0.6 cm/year. A similar style of foreland basin has been previously identified over a distance of 1000 Km from western central Venezuela to Trinidad. Eocene to Pliocene ages of foreland basin sedimentation in these areas suggest time transgressive, oblique collision of the Caribbean plate along the northern margin of South America. Comparison of the age of deformation along both the northern and southern edges of the pro-Caribbean plate yield reasonable estimates for the rate of relative motion of this small plate relative to the larger America plates.

  17. [Enterobius vermicularis in preschool children from a suburban area in San Félix, Bolívar State, Venezuela].

    PubMed

    Requena, Ixora; Jiménez, Yolimar; Rodríguez, Natacha; Sandoval, Maria; Alcala, Frannegy; Blanco, Ytalia; Devera, Rodolfo

    2007-09-01

    To determine the enterobiosis prevalence in preschool children, a study was carried out from may-july 2003, in the SEU "Teresa de la Parra" in San Félix, Bolívar State, Venezuela. Three samples from the perianal region were obtained from every child, by applying the Graham method, and one sample was obtained of the subungucal deposit by scraping and cutting off their finger nails. These samples were preserved in 10% formol and processed by the formol-ether method. Also, a stool sample was collected and analyzed by direct examination and the formol-ether method. The prevalence of Enterobius vermicularis was 45.8% (27/59). No differences in relation to age (chi2 = 1.23 d. f. = 2) and sex (p > 0.05) were observed between the infected children. The eggs E. vermicularis were not observed in the 59 samples of subungueal deposits. In conclusion, although the enterobiosis prevalence was high, as determined by the Graham method, a relationship could not be found between E. vermicularis in the scotch tape and the finger nail samples of the children evaluated. PMID:17853787

  18. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches

    PubMed Central

    de Noya, Belkisyolé Alarcón; Díaz-Bello, Zoraida; Colmenares, Cecilia; Ruiz-Guevara, Raiza; Mauriello, Luciano; Muñoz-Calderón, Arturo; Noya, Oscar

    2015-01-01

    Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana’s signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission. PMID:25946155

  19. Political economy of petrodollars: oil and democracy in Venezuela (Volumes I and II)

    SciTech Connect

    Karl, T.L.

    1982-01-01

    This thesis explores the impact of changes in the international petroleum economy upon the development strategy and political process of one oil-producing nation, Venezuela. It contends that sudden great wealth, like scarcity, can be a serious development curse, leading to policy decisions that provoke economic disruption and political decay. This ''paradox of plenty'' can best be explained by the interplay of an internationally-generated crisis of wealth with the skewed socio-economic arrangements and weak states characteristic of late developers. This interaction results in management overload and a subsequent decline in the problem-solving abilities of the state, making the effective utilization of petrodollar surpluses exceedingly difficult. An investigation of the political and economic consequences of the Perez Adminsitration's attempt to build a diversified industrial structure following the quadrupling of oil prices in 1973 illustrates this central theme. President Perez' ''project'' of accelerated modernization, designed to meet the competing demands of party and business interests, led to a contradictory development model which was both populist and entrepreneurial.

  20. Biostratigraphic sequence analysis of Oligocene-Lower Miocene sections in the Orocual Field, Eastern Venezuela Basin

    SciTech Connect

    Giffuni, G.; Castro-Mora, M.

    1996-08-01

    A detailed biostratigraphic study of the Oligocene-Miocene boundary was carried out in sections 1000 ft thick of ten wells of the Orocual Field, Eastern Venezuela, The sequences under investigation carry a rich microfauna of benthic and planktonic foraminifera and calcareous nannoplankton. About 500 samples were analyzed and nearly 150 species of foraminifera and 60 of nannoplankton calcareous were identified. The planktonic assemblages allow the identification of zones N3 and N4 of Blow, 1969; zones NP23, NP24, NP25 and NN1 of Martini, 1971; and zones F and E of Stainforth et al., 1959 of the Carapita Formation. The paleoenvironments of these sediments were determined rather precisely and vary from inner shelf to middle slope. Paleobathymetric curves of several wells are included. High and low fossil abundance and diversity peaks were used to recognize two sequences of the third order and five of the fourth order between 24.8 Ma and 26.5 Ma. A generalized transgressive trend is evident from the Late Oligocene to the Early Miocene.

  1. [Spatio-temporal variation of subtidal meiofauna in a sandy beach from Northeastern Venezuela].

    PubMed

    Arana, Ildefonso Liñero; Ojeda, Sol; Amaro, María Elena

    2013-03-01

    Meiofauna organisms that play an important role in the trophic ecology of soft bottom benthos, have short life cycles and they respond quickly to disturbance and pollution. The present study shows the spatio-temporal variation ofsubtidal meiofauna (metazoans passing a 500im sieve but retained on meshes of 40-63micro m) in four shallow subtidal stations. Samples were taken in the sandy beach of San Luis, in the Northeastern coast of Venezuela, from October 2005 until September 2006. For this, three replicate sediment core samples (4.91cm2), were collected monthly to a depth of 10cm into the sediment, and preserved in 6% formalin stained with rose Bengal. Specimens of 14 meiofaunal groups (Foraminifera excluded) were collected, being the nematodes, ostracods and harpacticoid copepods the most abundant. Monthly density was comprised between 64 and 503ind./10cm2, and mean density of stations between 173 and 449ind./10cm2. There is a trend of low densities from October to February (end of the rainy season until the middle of the dry season). The San Luis beach control of the meiofaunal community is shared by climatic conditions and by the biology of the species found. The meiofauna mean density in San Luis beach (263ind./10cm2) was low when compared to other studies in tropical areas. PMID:23894963

  2. Structure of the Mérida Andes, Venezuela: relations with the South America-Caribbean geodynamic interaction

    NASA Astrophysics Data System (ADS)

    Audemard, Felipe E.; Audemard, Franck A.

    2002-02-01

    For over 50 years, several models based on diverse geologic concepts and variable quality of data have been proposed to explain the major structure and history of the Mérida Andes (MA), in western Venezuela. Lately, this chain growth and associated flexural basins deepening have been related to incipient type-A subductions of either polarity, accounting for the across-chain asymmetry. However, these recent models have not well integrated the present tectonically active setting driven by neighboring major plate interactions. At present, this chain exhibits ongoing strain partitioning where cumulative right-lateral slip along chain axis is as much as half of, or about the same, as the transverse shortening since late Miocene, thus implying that the NNE-directed Maracaibo block extrusion with respect to the South America (SA) plate is not a secondary feature. Consequently, this paper discusses some limitations exhibited by the SE-directed continental subduction models-Maracaibo crust underthrusting the Mérida Andes-in the light of available geological and geophysical data. Besides, it is herein proposed that the Mérida Andes structuration is related to a NW-directed, gently dipping, incipient type-A subduction, where chain growth and evolution are similar to those of a sedimentary accretionary wedge (i.e., Barbados), but at crustal scale and with ongoing strain partitioning. This continental subduction is the SE portion of a major orogenic float that also comprises the Perijá range and the Santa Marta block.

  3. Structure of the Mérida Andes, Venezuela: relations with the South America Caribbean geodynamic interaction

    NASA Astrophysics Data System (ADS)

    Audemard, Felipe E.; Audemard, Franck A.

    2002-02-01

    For over 50 years, several models based on diverse geologic concepts and variable quality of data have been proposed to explain the major structure and history of the Mérida Andes (MA), in western Venezuela. Lately, this chain growth and associated flexural basins deepening have been related to incipient type-A subductions of either polarity, accounting for the across-chain asymmetry. However, these recent models have not well integrated the present tectonically active setting driven by neighboring major plate interactions. At present, this chain exhibits ongoing strain partitioning where cumulative right-lateral slip along chain axis is as much as half of, or about the same, as the transverse shortening since late Miocene, thus implying that the NNE-directed Maracaibo block extrusion with respect to the South America (SA) plate is not a secondary feature. Consequently, this paper discusses some limitations exhibited by the SE-directed continental subduction models—Maracaibo crust underthrusting the Mérida Andes—in the light of available geological and geophysical data. Besides, it is herein proposed that the Mérida Andes structuration is related to a NW-directed, gently dipping, incipient type-A subduction, where chain growth and evolution are similar to those of a sedimentary accretionary wedge (i.e., Barbados), but at crustal scale and with ongoing strain partitioning. This continental subduction is the SE portion of a major orogenic float that also comprises the Perijá range and the Santa Marta block.

  4. Salmonella on feces, hides and carcasses in beef slaughter facilities in Venezuela.

    PubMed

    Narváez-Bravo, Claudia; Rodas-González, Argenis; Fuenmayor, Yrimar; Flores-Rondon, Carolina; Carruyo, Gabriela; Moreno, Mireya; Perozo-Mena, Armindo; Hoet, Armando E

    2013-09-01

    This study determined Salmonella prevalence at different stages during the slaughtering in three beef slaughter plants (A, B and C) located in the western region of Venezuela (Zulia and Lara states). Each facility was visited three times at monthly intervals, from the months October through December of 2006. Samples were collected from hides (n=80), fecal grabs (n=80) and carcasses (n=80) at the phases of pre-evisceration, after-evisceration and pre-cooler at three sampling sites on the animals (rump, flank and brisket). Salmonella prevalence was higher on hides (36.3%) than on feces (13.8%) (P<0.05). Differences among slaughter plants for overall Salmonella prevalence were observed (P=0.001; A: 3.5%, B: 11.1%, C: 4.4%). From the isolated strains, Salmonella enterica subspecies enterica ser. Saintpaul, Salmonella ser. Javiana and Salmonella ser. Weltevreden were identified. Cattle feces and hides might be considered as important sources of Salmonella for carcass contamination at different slaughter stages. The presence of potentially pathogenic Salmonella serotypes at the slaughtering stages is an evidence of the circulation of this pathogen in the food environment; its presence could increase consumers' risks of infection if proper food handling and preparation techniques are not followed. These data should serve as a baseline for future comparisons in Salmonella prevalence on beef carcasses to be used by the government and industry in order to establish preventive measures and to better address the risks of Salmonella contamination. PMID:23973832

  5. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches.

    PubMed

    de Noya, Belkisyolé Alarcón; Díaz-Bello, Zoraida; Colmenares, Cecilia; Ruiz-Guevara, Raiza; Mauriello, Luciano; Muñoz-Calderón, Arturo; Noya, Oscar

    2015-05-01

    Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana's signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission. PMID:25946155

  6. [Diversity, abundance and distribution of benthic macrofauna on rocky shores from North Sucre State, Venezuela].

    PubMed

    Fernandez, Johanna; Jiménez, Mayré; Allen, Thays

    2014-09-01

    The rocky intertidal zone is among the most extreme physical environments on Earth. Organisms living in this area are constantly stricken by physico-chemical and biological factors. Due to the ecological importance of these areas, we studied the diversity, abundance and distribution of the rocky coastline benthic macrofauna, from the North coast of Sucre State, Venezuela. We performed bimonthly samplings from November 2008 to September 2009. The collection of biological material in the littoral zone (supra, mid and infralittoral) was done manually with a grid of 0.25m2. Organisms were preserved in 10% formalin for later identification and analysis (ecological parameters and Kruskal-Wallis test to the abundance and diversity). We found a total 19,020 organisms (86 spp.), in 8 phyla, 45 families and 47 genera. Mollusks were the most abundant and diverse (58 spp.), followed by arthropods (12 spp.), annelids (7 spp.), echinoderms (5 spp.), and the less represented cnidarians, sipunculids, nemertinids and urochordates (1 sp.). The zonation found coincided with the universal scheme of zonation. The towns of Rio Boca and Rio Caribe presented the highest values of ecological parameters, and the lowest were found in Playa Grande. Statistical significant differences were found in the abundance and diversity of macrofauna among the three zones. The little information on the composition and distribution of macrobenthic rocky coastline, prevents a better comparison, however the results contribute to the knowledge of the marine biodiversity in this region. PMID:25412527

  7. Biogenic nitrogen gas production at the oxic-anoxic interface in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Montes, E.; Altabet, M. A.; Muller-Karger, F. E.; Scranton, M. I.; Thunell, R. C.; Benitez-Nelson, C.; Lorenzoni, L.; Astor, Y. M.

    2012-08-01

    Excess nitrogen gas (excess N2) was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions) and March 2009 (upwelling conditions). During both sampling periods, excess N2 concentrations were below detection in surface waters, increasing to ~22 ?mol N kg-1 at the oxic-anoxic interface ([O2] < ~ 4 ?mol N kg-1, ~250 m). Below the oxic-anoxic interface (300-400 m), the average concentration of excess N2 was 24.7 ± 1.9 ?mol N kg-1 in September 2008 and 27.5 ± 2.0 ?mol N kg-1 in March 2009, i.e., excess N2 concentrations within this depth interval were ~ 3 ?mol N kg-1 higher (p < 0.001) during the upwelling season compared to the non-upwelling period. These results suggest that N-loss in the Cariaco Basin may vary seasonally in response to changes in the flux of sinking particulate organic matter. We attribute the increase in excess N2 concentrations, or N-loss, observed during upwelling to: (1) higher availability of fixed nitrogen derived from suspended and sinking particles at the oxic-anoxic interface and/or (2) enhanced ventilation at the oxic-anoxic interface during upwelling.

  8. Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela

    PubMed Central

    Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cárdenas, Lya; Sánchez, Víctor; Estrada, Yarys; Anaya, William; Martínez, Ángela

    2013-01-01

    To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet(r) Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally. PMID:23579803

  9. Assessment of Fatty Liver Syndrome and Its Predisposing Factors in a Dairy Herd from Venezuela

    PubMed Central

    Gonzalez, Clara I.

    2013-01-01

    The present on-farm research evaluated the occurrence of fatty liver syndrome and its predisposing risk factors for multiparous dairy cows from a commercial herd in Venezuela. Liver biopsy samples were collected at 35 days (d) prepartum (Holstein, n = 14; Holstein × Carora crossbred, n = 17) as well as 1 to 7?d (Holstein, n = 8; Holstein × Carora crossbred, n = 11) and 28 to 35?d (Holstein, n = 6; Holstein × Carora crossbred, n = 14) postpartum in order to analyse hepatic triacylglycerols (TAG, % wet basis) and glycogen concentrations. At postpartum, an occurrence of 72.0% for severe fatty liver along with 73.5% of subclinical ketosis (SCK) was found. The multiple regression model that best explained the association between milk production in the previous lactation (MYP) and TAG at first week postpartum was as follows: TAG, % = ?11.2 + 3.16 (prepartum body condition) + 0.0009176 (MYP) (R² = 0.36, P < 0.05). Logistic regression indicated that Holstein × Carora crossbred cows tended to have 27% higher relative risk than Holstein to experience SCK, whereas prepartum liver TAG greater than 3% tended to be associated with a higher relative risk for SCK compared to cows with TAG ?3%. PMID:23738138

  10. Optical characterization of dissolved organic matter in tropical rivers of the Guayana Shield, Venezuela

    NASA Astrophysics Data System (ADS)

    Yamashita, Youhei; Maie, Nagamitsu; BriceñO, Henry; Jaffé, Rudolf

    2010-03-01

    Tropical rivers are an important source of dissolved organic matter (DOM) to coastal oceans. However, temporal and spatial variability of DOM composition and thus its quality in such rivers, on landscape and basin scales, have not been well documented. In this study, we present data on the spatial distribution of DOM quantity and quality based on source, molecular weight, and composition using optical properties including excitation emission matrix fluorescence with parallel factor analysis. We compared such DOM quantity and quality determinations in main river channels and their tributaries for three river systems of the Guayana Shield, Venezuela. Spatial variabilities of DOM parameters were strongly related to differences in the geological settings of the drainage basins and presumably their associated vegetation cover. Linear relationships between quantitative and qualitative DOM parameters were also evident, suggesting that high DOC concentration correlated with chromophoric dissolved organic matter (CDOM) characteristics of higher molecular weight associated with terrestrial sources, while low DOC concentrations correlated with CDOM characteristics of lower molecular weight associated primarily with microbial sources. Such relationships seem to imply that DOM concentrations and their sources/characteristics may be coupled in the studied fluvial systems. In addition, shifts in DOM compositions between terrestrial and microbial signals were observed with changes in water discharge and in watersheds disturbed by gold mining activities. The observed linkages between, and the changes among DOM quantity and quality, suggest that the biogeochemistry of DOM in tropical rivers may be quite sensitive to climatic and land use change.

  11. Helicobacter pylori Infection in Rural and Urban Dyspeptic Patients from Venezuela.

    PubMed

    Contreras, Monica; Fernández-Delgado, Milagro; Reyes, Nelson; García-Amado, María Alexandra; Rojas, Héctor; Michelangeli, Fabian

    2015-10-01

    The goal of this work was to assess the Helicobacter pylori prevalence in a rural mestizo population and compare it to an urban population from Venezuela. The study was performed in gastric juice samples of 71 dyspeptic patients from Caracas (urban) and 39 from Tucupita (rural), in the Orinoco Delta region. Helicobacter pylori was detected by amplification of 16S rRNA, glmM, and ureA genes in 55.0% patients from urban and 87.2% from rural populations. cagA was found positive in 51% and 62% urban and rural patients, respectively. Non-H. pylori Helicobacter species were not detected in the urban population, but was found in 7.7% of patients in the rural study site. Frequency values of the 16S rRNA, glmM, and ureA genes were higher in the rural population. The odds ratio for each gene was 15.18 for 16S rRNA, 2.34 for glmM, 2.89 for ureA, and 1.53 cagA, showing significant differences except for cagA when gene frequency was compared in both populations. These results demonstrate a higher frequency of H. pylori and gastric non-H. pylori Helicobacter infection in a rural mestizo population with low hygienic standards as compared with city dwellers, representing a potential risk for the development of gastroduodenal diseases. PMID:26195456

  12. Biogenic nitrogen gas production at the oxic-anoxic interface in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Montes, E.; Altabet, M. A.; Muller-Karger, F. E.; Scranton, M. I.; Thunell, R. C.; Benitez-Nelson, C.; Lorenzoni, L.; Astor, Y. M.

    2013-01-01

    Excess nitrogen gas (N2xs) was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions) and March 2009 (upwelling conditions). During both sampling periods, N2xs concentrations were below detection in surface waters, increasing to ~ 22 ?mol N kg-1 at the oxic-anoxic interface ([O2] < ~ 4 ?mol kg-1, ~ 250 m). Below the oxic-anoxic interface (300-400 m), the average concentration of N2xs was 24.7 ± 1.9 ?mol N kg-1 in September 2008 and 27.5 ± 2.0 ?mol N kg-1 in March 2009, i.e., N2xs concentrations within this depth interval were ~ 3 ?mol N kg-1 higher (p < 0.001) during the upwelling season compared to the non-upwelling period. These results suggest that N-loss in the Cariaco Basin may vary seasonally in response to changes in the flux of sinking particulate organic matter. We attribute the increase in N2xs concentrations, or N-loss, observed during upwelling to: (1) higher availability of fixed nitrogen derived from suspended and sinking particles at the oxic-anoxic interface and/or (2) enhanced ventilation at the oxic-anoxic interface during upwelling.

  13. Predominant Periods and Shear Wave Velocity an indicator for Sediment Thickness, Caracas, Venezuela

    NASA Astrophysics Data System (ADS)

    Rocabado, V.; Schmitz, M.

    2013-05-01

    Within the Caracas seismic microzoning project, carried out by Venezuelan Foundation for Seismological Research (FUNVISIS), more than 1500 single measurements of ambient noise have been done since mid-90's in order to determinate fundamental periods of soil. In this work we show the result of these single stations applying H/V analysis, with period values between 0.2s and 2.4s, we propose a new relationship to estimate sediment thickness from period values, including the effect of the surface sediment layers, considering the values of shear-wave velocities for the first 30 m (Vs30) and the Vs value of the sedimentary layer, just above bedrock. The results indicate that this relationship generates more accurate estimates of sediment thickness comparing with depth values from other geophysical methods; this relationship was calibrated with information from 4 depth boreholes in Caracas, obtaining accurate depth values. The main objective of this new relationship is consider local information of soils in other cities, for local relationships between periods and sediment thickness, to generate accurate sediment thickness estimates from environmental noise measurements within seismic microzoning projects in Venezuela's most important cities.

  14. Geological Studies in eastern Venezuela and Trinidad from Cretaceous passive margin to Neogene transpressional thrust belt

    SciTech Connect

    Algar, S.T.; Erikson, J.E.; Pindell, J.L. )

    1991-03-01

    Sedimentological and structural analyses of Trinidad's Northern and Central ranges and Venezuela's Serrania del Interior have led to new interpretations of northeastern. South America's tectonic evolution within the Southern Caribbean Plate Boundary Zone. Medial ( ) Jurassic through early Cenozoic passive margin sediments make up the majority of these areas and were deposited somewhat to the WNW (between 80 and 130 km for Northern Range of Trinidad) of their present positions prior to structural shortening. Neogene southeastward displacement of Jurassic-Cretaceous passive slope and rise sediments (Northern Range) drove propagation of thrusts southward into the Serrania and Central ranges. Displacements were driven by migration of the Caribbean Plate relative to South America. Thus, the Serrania and Central ranges are the western hemisphere's only exposed Mesozoic-Cenozoic passive Atlantic margin stratigraphic section. As such, they provide a Cretaceous-Paleogene record of passive margin sedimentation at a thermally subsiding margin where the complicating effects of tectonism are absent. This makes these sections especially suited for studies of eustatic sea level behavior. Preliminary assessments are shown which suggest that sea level changes for Cretaceous to Paleogene time are not as pronounced as the frequent large and rapid sea level falls and rises that are promoted by some.

  15. Development of Caribbean plate tectonics: A contribution from oil exploration in Venezuela

    SciTech Connect

    Fuentes, J. ); Oum, S. ); Lander, R. )

    1990-05-01

    Following several huge oil and gas discoveries during the mid-1980s in the Northern Venezuela overthrust belt more detailed geological and geophysical studies have increased their perception of structural control on sedimentary basin development. Significant improvements in seismic data quality and seismic lines positioned close to outcrops of the frontal thrust give evidence of Miocene to Pleistocene thin-skinned tectonics as the mechanism of the formation of the overthrust belt of the Serrania del Interior. The authors conclude that the thrust sheet was formed by the effects of major right-lateral transcurrent movements along the El Pilar fault system, which forced metasediments against thick Miocene clastics in pull-apart basins. These basins were created earlier by strike-slip motions of preexisting parallel en-echelon normal faults. The eastwardly mobile Caribbean plate boundary and its evolution from a collision to a transpression zone is documented and a new approach to an evaluation of oil and gas potential is made of multiple reservoirs in stacked, folded thrust sheets.

  16. [Mosquito fauna (Diptera:Culicidae) from Falcon State, Venezuela. I. New records and current checklist].

    PubMed

    Navarro, J C; Bastidas, R J; Zavala, Y

    1994-01-01

    A total of 16 new species records of Culicidae from Falcon State was collected at the "Juan Crisostomo Falcon National Park" (Sierra de San Luis), Natural Monument "Cerro Santa Ana", Coro, and La Vela. Species of Sabethini, Culicini and Toxorhynchitini Tribes were found in natural breeding sites (Phytotelmata), with special occurrence in plants belonging to Tillandsia, Vriesea, Guzmania, Aechmea (Bromelianceae), Heliconia (Heliconiaceae), Calathea (Marantaceae) and Colocasia (Araceae). Aedini and Mansonini were collected only as adults. A specie of Culex (Carrollia) was collected from an artificial container. The Culicidae species belong to 6 genera out of the 23 genera reported from Venezuela (Culex, Wyeomyia, Johnbelkinia, Aedes, Psorophora, Mansonia and Coquillettidia) and to 5 Tribes out of the 9 present in the country. The Aedini, Sabethini and Culicini Tribes were richer in species with 5, 4 and 4 species, respectively, than the Mansonini (2 species) and Toxorhynchitini (1 species) Tribes. We discuss some bioecological aspects regarding the 16 new-species records in Falcon State and give a checklist of the mosquito species previously reported in the literature. PMID:9239851

  17. Estimation of the intrinsic absorption and scattering attenuation in Northeastern Venezuela (Southeastern Caribbean) using coda waves

    USGS Publications Warehouse

    Ugalde, A.; Pujades, L.G.; Canas, J.A.; Villasenor, A.

    1998-01-01

    Northeastern Venezuela has been studied in terms of coda wave attenuation using seismograms from local earthquakes recorded by a temporary short-period seismic network. The studied area has been separated into two subregions in order to investigate lateral variations in the attenuation parameters. Coda-Q-1 (Q(c)-1) has been obtained using the single-scattering theory. The contribution of the intrinsic absorption (Q(i)-1) and scattering (Q(s)-1) to total attenuation (Q(t)-1) has been estimated by means of a multiple lapse time window method, based on the hypothesis of multiple isotropic scattering with uniform distribution of scatterers. Results show significant spatial variations of attenuation: the estimates for intermediate depth events and for shallow events present major differences. This fact may be related to different tectonic characteristics that may be due to the presence of the Lesser Antilles subduction zone, because the intermediate depth seismic zone may be coincident with the southern continuation of the subducting slab under the arc.

  18. Geomorphic effects of large debris flows and flash floods, northern Venezuela, 1999

    USGS Publications Warehouse

    Larsen, M.C.; Wieczorek, G.F.

    2006-01-01

    A rare, high-magnitude storm in northern Venezuela in December 1999 triggered debris flows and flash floods, and caused one of the worst natural disasters in the recorded history of the Americas. Some 15,000 people were killed. The debris flows and floods inundated coastal communities on alluvial fans at the mouths of a coastal mountain drainage network and destroyed property estimated at more than $2 billion. Landslides were abundant and widespread on steep slopes within areas underlain by schist and gneiss from near the coast to slightly over the crest of the mountain range. Some hillsides were entirely denuded by single or coalescing failures, which formed massive debris flows in river channels flowing out onto densely populated alluvial fans at the coast. The massive amount of sediment derived from 24 watersheds along 50 km of the coast during the storm and deposited on alluvial fans and beaches has been estimated at 15 to 20 million m3. Sediment yield for the 1999 storm from the approximately 200 km2 drainage area of watersheds upstream of the alluvial fans was as much as 100,000 m3/km2. Rapid economic development in this dynamic geomorphic environment close to the capital city of Caracas, in combination with a severe rain storm, resulted in the death of approximately 5% of the population (300,000 total prior to the storm) in the northern Venezuelan state of Vargas. ?? 2006 Gebru??der Borntraeger.

  19. Oceanic influence on the precipitation in Venezuela under current and future climate

    NASA Astrophysics Data System (ADS)

    Tim, Nele; Bravo de Guenni, Lelys

    2015-09-01

    The Pacific and Atlantic oceanic influences on observational rainfall data from weather stations over Venezuela are analyzed using Canonical Correlation Analysis (CCA) executed in the Climate Predictability Tool. CCA is further conducted on rainfall and sea surface temperature data obtained from the Max Planck Institute for Meteorology Earth System Model (MPI-ESM) for historical (1951-2010) and future (2041-2100) periods. Four oceanic regions (North Tropical Atlantic, Niño3, Niño3.4 and an area which includes all previous three) are used for the CCA using data from the Extended Reconstructed Sea Surface Temperature (ERSST) data set, while precipitation data from two regions: a coastal region and an inland region are used in the analysis. Venezuelan seasons (dry and wet) were separated into an early and a late period. The oceanic impact on the precipitation of the station data is, in the majority of the cases, higher in the inland than at the coast. The Pacific's influence is stronger in the early dry season than in the wet season, whereas the Atlantic's influence is stronger in the wet season (inland). In contrast, CCA applied to the model data provides highest correlation coefficients in the late wet season for all oceanic regions. In most cases the North Tropical Atlantic has a stronger influence than the Niño regions.

  20. Estimation of undiscovered deposits in quantitative mineral resource assessments-examples from Venezuela and Puerto Rico

    USGS Publications Warehouse

    Cox, D.P.

    1993-01-01

    Quantitative mineral resource assessments used by the United States Geological Survey are based on deposit models. These assessments consist of three parts: (1) selecting appropriate deposit models and delineating on maps areas permissive for each type of deposit; (2) constructing a grade-tonnage model for each deposit model; and (3) estimating the number of undiscovered deposits of each type. In this article, I focus on the estimation of undiscovered deposits using two methods: the deposit density method and the target counting method. In the deposit density method, estimates are made by analogy with well-explored areas that are geologically similar to the study area and that contain a known density of deposits per unit area. The deposit density method is useful for regions where there is little or no data. This method was used to estimate undiscovered low-sulfide gold-quartz vein deposits in Venezuela. Estimates can also be made by counting targets such as mineral occurrences, geophysical or geochemical anomalies, or exploration "plays" and by assigning to each target a probability that it represents an undiscovered deposit that is a member of the grade-tonnage distribution. This method is useful in areas where detailed geological, geophysical, geochemical, and mineral occurrence data exist. Using this method, porphyry copper-gold deposits were estimated in Puerto Rico. ?? 1993 Oxford University Press.

  1. Geochemical study of the organic matter from Querecual formation, Anzoategui State, Venezuela

    SciTech Connect

    Garban, G.; Lopez, L.; Lo Monaco, S.; Lira, A.

    1996-08-01

    Kerogen and bitumen fractions extracted from twenty-one limestone samples from kind section of Querecual formation (Querecual River, Anzoategui State, Venezuela) were analyzed for their content of Co, Cr, Fe, Mn, Mo, Ni, S, Sr, V and Zn. S and trace-metals content from the kerogen fraction were used to obtain information about paleoenvironmental sedimentation conditions of the Querecual formation. Based on these data, and especially on the V and S content variations plus V/Ni, VIV+Ni and Mo/Mo+Cr ratios, we confirm an ancient-reducer condition on this region according with a sulfur-reducer environment. Trace-metals content variations from the bitumen fraction along the study section were used as possible primary migration indicators. V and Ni were the only elements showing a clear tendency to be used as primary migration indicators. The observed tendency allows us to postulate a vertical migration of the bitumen, from center to the extremes of the section.

  2. Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves

    USGS Publications Warehouse

    Mendoza, C.

    2000-01-01

    A two-step finite-fault waveform inversion scheme is applied to the broadband teleseismic P waves recorded for the strike-slip, Cariaco, Venezuela, earthquake of 9 July 1997 to recover the distribution of mainshock slip. The earthquake is first analyzed using a long narrow fault with a maximum rise time of 20 sec. This line-source analysis indicates that slip propagated to the west with a constant rupture velocity and a relatively short rise time. The results are then used to constrain a second inversion of the P waveforms using a 60-km by 20-km two-dimensional fault. The rupture shows a zone of large slip (1.3-m peak) near the hypocenter and a second, broader source extending updip and to the west at depths shallower than 5 km. The second source has a peak slip of 2.1 meters and accounts for most of the moment of 1.1 × 1026 dyne-cm (6.6 Mww) estimated from the P waves. The inferred rupture pattern is consistent with macroseismic effects observed in the epicentral area.

  3. Breeding biology and natural history of the Slate-throated Whitestart in Venezuela

    USGS Publications Warehouse

    Ruggera, R.A.; Martin, T.E.

    2010-01-01

    We provide details on the breeding biology of the Slate-throated Whitestart (Myioborus miniatus) from 126 nests found during seven breeding seasons, 2002-2008, at Yacamb?? National Park, Venezuela. Nesting activity peaked in late April and May. Only the female built the nest and incubated the eggs. Males rarely visited the nest during these stages. Mean clutch size (2.1 ?? 0.04 eggs, n = 93) was the smallest recorded for the Slate-throated Whitestart. Incubation and nestling period lengths were 15.3 ?? 0.31 (n = 21) and 10.8 ?? 0.24 (n = 7) days, respectively. Attentiveness (% of time on the nest) during incubation (59 ?? 1.6%, n = 52) was similar to other tropical warblers and much lower than northern relatives. This caused a relatively low egg temperature (34.40 ?? 0.33u C, n = ?? nests, 20 days) compared with north temperate birds. Both parents fed nestlings and increased their provisioning rates with nestling age. Growth rate based on nestling mass (k = 0.521 ?? 0.015) was faster than for other tropical passerines but slower than northern relatives. Predation was the main cause of nesting failure and rate of predation increased with age of the nest. An estimated 15% of nests were successful based on an overall Mayfield daily predation rate of 0.053 ?? 0.007. This study confirms a strong latitudinal variation in life history traits of warblers. ?? 2010 by the Wilson Ornithological Society.

  4. Malaria Control in Amerindian Communities of Venezuela : Strengthening Ecohealth Practice Throughout Conservation Science and Capability Approach.

    PubMed

    Bevilacqua, Mariapia; Rubio-Palis, Yasmin; Medina, Domingo A; Cárdenas, Lya

    2015-06-01

    Adaptive management and ecohealth frameworks were developed for malaria elimination in Amerindian riparian communities of Venezuela. These frameworks were developed as a strategy to capture, organize, and communicate connections among key factors related to local malaria complex systems. Important causal relationships between social, economic, and environmental stressors which are determinant of malaria were identified at different levels and assumptions that guide interventions are offered, based on available scientific knowledge and input from stakeholders. Drawing on our experience of action research committed to the health of Amerindian populations and conservation of areas with biodiversity value, the authors provide lessons to strengthen the practice of an ecohealth approach. First, conservation targets were considered as a way to achieve sustainable human well-being rather than as a consequence of well-being. Second, the effectiveness and sustainability of technical solutions generally proposed for malaria control depend largely on individual knowledge, attitudes, and practices. Hence, it is necessary to look at the real opportunities of choices that Amerindian people have for attaining a life without malaria, and therefore pay attention to local capabilities, needs, and freedom to choose. The ecohealth approach can benefit from the capability approach, and we explain why. PMID:25851195

  5. Geological photointerpretation of the Paraguana Peninsula using ERTS-A multispectral photography. [Venezuela

    NASA Technical Reports Server (NTRS)

    Albrizzio, C.

    1974-01-01

    A methodology was developed to evaluate multispectral analysis of orbital imagery on the interpretation of geology, coastal geomorphology and sedimentary processes. The images analyzed were obtained during the pass of ERTS satellite over the center region of Venezuela on October 19, 1972. ERTS-1 multispectral images in black and white paper copies and transparencies of the 4 bands and false color composites at scales of 1:1,000,000 and 1:500,000 were interpreted. Lithology and outcrop patterns of the following geological formations have been interpreted: igneous and metamorphic basement of Cocodite and Santa Ana, Jurassic-Cretaceous metamorphics of Pueblo Nuevo, Cantaure Miocene-Pliocene sediments, and Quaternary alluvium, dunes, beach ridges, bars and reefs. A prominent and extensive Paraguana tonal anomaly shaped as an 8 has been discovered at the NW of the Peninsula. Its erosional origin has exposed light toned lower beds at the center, with additional evidence of topographic depression and development of underground drainage of karst origin. Coastal geomorphology, its processes and energy has been interpreted with the help of wind direction analysis (ENE-WSW) at sea level through the orientation of transported materials (water vapor, water and sediments) by clouds, waves, sea current, plumes of suspended sediments associated to river outlets, dunes, sediment sources and shore-line orientation.

  6. [Diarrheagenic Escherichia coli associated with acute diarrhea in children of Cumaná, Venezuela].

    PubMed

    Hannaoui, Erika; Villalobos, Luz; Martínez, Rosa; Maldonado, Antonio; Hagel, Isabel; Bastardo, Jesús

    2010-12-01

    To establish the prevalence of strains of diarrheagenic Escherichia coli (DEC) associated to acute diarrhea in children of Cumaná, Venezuela, stool samples were taken from 200 children aged < 5 years with acute diarrheal disease, and from 30 healthy children used as control. Isolation and bacterial identification was performed by conventional biochemical tests and stool cultures. The presence of pathogenic genes of each type of DEC was investigated by the technique of polymerase chain reaction (PCR), determining the genes eae and bfp (EPEC), st and lt (ETEC), ipaH and virF (EIEC) Stx1/Stx2 (STEC), aafII (EAEC) and daaE (ADEC). From 169 E. coli, isolates we determined by PCR 10.65% positive for EPEC (1.18% "typical", 9.47% "atypical"); ETEC (5.91%); EAEC (1.78 %), EIEC (0.59%). There were no statistically significant differences regarding the frequency of each "pathotype" in relation to age, but it did occur when related to the sex (p<0.05). The most relevant clinical features were: fever, vomiting and abdominal pain and the greatest percentage of children affected were of the working and marginal classes. These results shown that the strains of DEC are important etiological agents in acute infectious diarrhea in children of Cumaná. PMID:21365876

  7. Ecological studies of enzootic Venezuelan equine encephalitis in north-central Venezuela, 1997-1998.

    PubMed

    Salas, R A; Garcia, C Z; Liria, J; Barrera, R; Navarro, J C; Medina, G; Vasquez, C; Fernandez, Z; Weaver, S C

    2001-01-01

    From 1997-1998, we investigated the possible continuous circulation of epizootic Venezuelan equine encephalitis (VEE) virus suggested by a 1983 subtype IC interepizootic mosquito isolate made in Panaquire, Miranda State, Venezuela. The study area was originally covered by lowland tropical rainforest but has been converted into cacao plantations. Sentinel hamsters, small mammal trapping, mosquito collections, and human serosurveys were used to detect active or recent virus circulation. Six strains of subtype ID VEE virus were isolated from hamsters that displayed no apparent disease. Four other arboviruses belonging to group A (Togaviridae: Alphavirus), two Bunyamwera group (Bunyaviridae), and three Gamboa group (Bunyaviridae) arboviruses were also isolated from hamsters, as well as 8 unidentified viruses. Venezuelan equine encephalitis-specific antibodies were detected in 5 small mammal species: Proechimys guairae, Marmosa spp., and Didelphis marsupialis. Mosquito collections comprised of 38 different species, including 8 members of the subgenus Culex (Melanoconion), did not yield any virus isolates. Sera from 195 humans, either workers in the cacao plantation or nearby residents, were all negative for VEE virus antibodies. Sequences of 1,677 nucleotides from the P62 gene of 2 virus isolates indicated that they represent a subtype ID lineage that is distinct from all others characterized previously, and are unrelated to epizootic VEE emergence. PMID:11425168

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

    SciTech Connect

    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.

  9. New Records of Mosquitoes (Diptera: Culicidae) from Bolívar State in South Eastern Venezuela, with 27 New Species for the State and 5 of Them New in the Country

    PubMed Central

    Berti, Jesús; Guzmán, Hernán; Estrada, Yarys; Ramírez, Rodrigo

    2015-01-01

    This is the first part of a series of studies related to mosquito ecological and biogeographic aspects. A total of 69 mosquito species (Diptera: Culicidae) was collected in 16 localities sampled in the Gran Sabana Municipality, Canaima National Park, and Venezuela. Twenty-seven mosquito species are recorded for the first time from Bolívar State, Venezuela. Five of them species are reported for the first time in Venezuela: Anopheles malefactor Dyar and Knab (1907); Chagasia bonneae Root (1927); Chagasia ablusa Harbach (2009); Culex anduzei Lane (1944), and Uranotaenia leucoptera Theobald (1907). Their medical importance is commented, and ecological and epidemiological aspects are discussed. A checklist of the mosquito species reported in the Gran Sabana County is given. PMID:25853113

  10. A new species of Caligus (Copepoda, Siphonostomatoida) from the plankton of the Caribbean coast of Venezuela with a key to species

    PubMed Central

    Suárez-Morales, Eduardo; Camisotti, Humberto; Martín, Alberto

    2012-01-01

    Abstract During a survey of the zooplankton community of Bahía Amuay, Venezuelan Caribbean, specimens of an undescribed species of Caligus Müller were collected. It resembles Caligus xystercus Cressey and Caligus ocyurus Cressey, both known only from the Caribbean Sea. The new species can be distinguished from these and other congeners by a combination of characters including the armature of legs 1 and 4, but mainly by its unique female genital complex. This is the first species of Caligus described from Venezuela. The species is described in full and a key to the species of the genus recorded in Venezuela is provided. PMID:22768004

  11. Prevalence of the metabolic syndrome, insulin resistance index, leptin and thyroid hormone levels in the general population of Merida (Venezuela).

    PubMed

    Uzcátegui, Euderruh; Valery, Lenin; Uzcátegui, Lilia; Gómez Pérez, Roald; Marquina, David; Baptista, Trino

    2015-06-01

    The metabolic syndrome (MetSyn) is a significant risk factor for cardiovascular events, but scarce information exists about its frequency in Venezuela. In this cross-sectional study, we quantified the prevalence of the MetSyn in a probabilistic, stratified sample of 274 subjects aged > or =18 years from the Libertador district in Merida, Venezuela. Secondary outcomes were the measurement of thyroid hormones (free T4 and TSH), leptin levels, and insulin resistance index (HOMA2-IR). The frequency of MetSyn (percentage +/- 95% confidence interval) according to several diagnostic criteria was as follows: National Cholesterol Education Panel (NCEP, original): 27.4% (22.1-32.7); modified NCEP: 31.8% (26.3-37.3); International Diabetes Federation: 40.9% (35.1-46.7); Latin American Diabetes Association: 27% (21.7-32.3), and Venezuelan criteria: 31.8% (26.3-37.3). The MetSyn was more frequent in males than in females with most diagnostic criteria. The estimated prevalence of type 2 diabetes mellitus was 2.9% either according to the patients' self reports or to fasting glucose level found to be above 126 mg/dL. Abnormal HOMA2-IR index, free T4 and TSH (above the 95th percentile) were detected in 4.5%, 4.4% and 5.1% of the sample, respectively. Free T4 and TSH levels below the 5th percentile were detected in 4.4% and 4.7% of subjects respectively. These values are presented for comparisons with forthcoming studies in specific clinical populations. While studies are being conducted about the different definitions of the MetSyn in Venezuela, we recommend analyzing and publishing local research data with all the available criteria so as to allow comparisons with the results already reported in the literature. PMID:26299057

  12. Non-capsulated and capsulated Haemophilus influenzae in children with acute otitis media in Venezuela: a prospective epidemiological study

    PubMed Central

    2012-01-01

    Background Non-typeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae are major causes of bacterial acute otitis media (AOM). Data regarding AOM are limited in Latin America. This is the first active surveillance in a private setting in Venezuela to characterize the bacterial etiology of AOM in children < 5 years of age. Methods Between December 2008 and December 2009, 91 AOM episodes (including sporadic, recurrent and treatment failures) were studied in 87 children enrolled into a medical center in Caracas, Venezuela. Middle ear fluid samples were collected either by tympanocentesis or spontaneous otorrhea swab sampling method. Standard laboratory and microbiological techniques were used to identify bacteria and test for antimicrobial resistance. The results were interpreted according to Clinical Laboratory Standards Institute (CLSI) 2009 for non-meningitis isolates. All statistical analyses were performed using SAS 9.1 and Microsoft Excel (for graphical purposes). Results Overall, bacteria were cultured from 69.2% (63 of the 91 episodes); at least one pathogen (S. pneumoniae, H. influenzae, S. pyogenes or M. catarrhalis) was cultured from 65.9% (60/91) of episodes. H. influenzae (55.5%; 35/63 episodes) and S. pneumoniae (34.9%; 22/63 episodes) were the most frequently reported bacteria. Among H. influenzae isolates, 62.9% (22/35 episodes) were non-capsulated (NTHi) and 31.4% (11/35 episodes) were capsulated including types d, a, c and f, across all age groups. Low antibiotic resistance for H. influenzae was observed to amoxicillin/ampicillin (5.7%; 2/35 samples). NTHi was isolated in four of the six H. influenzae positive samples (66.7%) from recurrent episodes. Conclusions We found H. influenzae and S. pneumoniae to be the main pathogens causing AOM in Venezuela. Pneumococcal conjugate vaccines with efficacy against these bacterial pathogens may have the potential to maximize protection against AOM. PMID:22335965

  13. A distinctive new subspecies of Scytalopus griseicollis (Aves, Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela

    PubMed Central

    Avendaño, Jorge Enrique; Donegan, Thomas M.

    2015-01-01

    Abstract We describe a new subspecies of Pale-bellied Tapaculo Scytalopus griseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopus griseicollis griseicollis and Scytalopus griseicollis gilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy. PMID:26085800

  14. A new species of small-eared shrew from Colombia and Venezuela (Mammalia: Soricomorpha: Soricidae: Genus Cryptotis)

    USGS Publications Warehouse

    Woodman, N.

    2002-01-01

    Populations of small-eared shrews inhabiting the northern Cordillera Oriental of Colombia and adjoining Venezuelan highlands in the vicinity of Paramo de Tama have been referred alternatively to Cryptotis thomssi or Cryptotis meridensis. Morphological and morphometrical study of this population indicates that it belongs to neither taxon, but represents a distinct, previously unrecognized species. I describe this new species as Cryptotis tamensis and redescribe C. meridensis. Recognition of the population at Paramo de Tama as a separate taxon calls into question the identities of populations of shrews currently represented only by single specimens from Cerro Pintado in the Sierra de Perija, Colombia, and near El Junquito in the coastal highlands of Venezuela.

  15. Genetic Diversity of Tn916-Related Transposons among Drug-Resistant Streptococcus pneumoniae Isolates Colonizing Healthy Children in Venezuela?

    PubMed Central

    Quintero, Beatríz; Araque, María; van der Gaast-de Jongh, Christa; Hermans, Peter W. M.

    2011-01-01

    Among a collection of 48 multidrug-resistant pneumococcal strains colonizing healthy children in a small municipality of Mérida, Venezuela, we identified sequence types (STs) related to a variety of internationally spreading drug-resistant clones, as well as ST135, thus far isolated only in Europe. The clones invariably harbored one or more of the Tn916-related transposons Tn3872, Tn5253, Tn6002, Tn2009, and Tn2010. Finally, our data suggest both structural rearrangements in certain transposons and occurrence of novel transposable elements. PMID:21788464

  16. A distinctive new subspecies of Scytalopusgriseicollis (Aves, Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela.

    PubMed

    Avendaño, Jorge Enrique; Donegan, Thomas M

    2015-01-01

    We describe a new subspecies of Pale-bellied Tapaculo Scytalopusgriseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopusgriseicollisgriseicollis and Scytalopusgriseicollisgilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy. PMID:26085800

  17. Geochronology of recent sediments from the Cariaco Trench (Venezuela) by Alpha Spectrometry of 210Pb (210Po).

    NASA Astrophysics Data System (ADS)

    Arriojas, A.; Barros, H.; Palacios, D.; Hurtado, S.; Villa, M.; Pérez, K.; Alfonso, J.; Sajo-Bohus, L.

    2010-08-01

    210Pb concentration in marine sediments of the Cariaco Trench (North-East of Venezuela) was measured through the analysis of 210Po alpha emissions, which can be assumed to be in secular equilibrium with 210Pb. The analysed sediment core has a length of 1.9 m. The results allowed to apply the CF:CS dating model (Constant Flux and Constant Supply). The sedimentation rate was estimated to be 0.25 cm/y. As far as we know this is the first ?- dating carried out in the country, performed with an alpha spectrometer recently funded by the IAEA.

  18. Geochronology of recent sediments from the Cariaco Trench (Venezuela) by Alpha Spectrometry of {sup 210}Pb ({sup 210}Po)

    SciTech Connect

    Arriojas, A.; Barros, H.; Palacios, D.; Sajo-Bohus, L.; Hurtado, S.; Villa, M.; Perez, K.; Alfonso, J.

    2010-08-04

    210Pb concentration in marine sediments of the Cariaco Trench (North-East of Venezuela) was measured through the analysis of 210Po alpha emissions, which can be assumed to be in secular equilibrium with 210Pb. The analysed sediment core has a length of 1.9 m. The results allowed to apply the CF:CS dating model (Constant Flux and Constant Supply). The sedimentation rate was estimated to be 0.25 cm/y. As far as we know this is the first {alpha}- dating carried out in the country, performed with an alpha spectrometer recently funded by the IAEA.

  19. Chagas’ Disease: An Emergent Urban Zoonosis. The Caracas Valley (Venezuela) as an Epidemiological Model

    PubMed Central

    Urdaneta-Morales, Servio

    2014-01-01

    The unprecedented emergence of important public health and veterinary zoonoses is usually a result of exponential population growth and globalization of human activities. I characterized Chagas’ disease as an emergent zoonosis in the Caracas Valley (Venezuela) due to the following findings: the presence of reservoirs (Didelphis marsupialis, Rattus rattus) and vectors (Panstrongylus geniculatus, Panstrongylus rufotuberculatus) infected with Trypanosoma cruzi in urbanized or marginalized areas; the elevated contact between P. geniculatus and human beings detected by parasitological and molecular examinations of triatomine feces demonstrated the possibility of transmission risks; a study of outbreaks of urban Chagas’ disease reported the first proven case of oral transmission of T. cruzi to human beings; the risk of transmission of glandular metacyclic stages from marsupials by experimental ocular and oral instillation; mice genitalia infected with T. cruzi contaminated blood resulted in the formation of amastigotes very close to the lumen suggesting that there may be a possibility of infection via their release into the urine and thence to the exterior; the ubiquitous histotropism and histopathology of T. cruzi was demonstrated using a mouse model; the presence of experimental T. cruzi pseudocysts in adipose, bone-cartilage, and eye tissue indicated a potential risk for transplants. Socio-sanitary programs that include improvements in housing, vector control, and access to medical treatment, as well as strategies aimed at combating social inequalities, poverty, and underdevelopment should be undertaken in those areas where zoonoses are most prevalent. Disciplines, such as Ecology, Epidemiology, Medical Entomology, Human and Veterinary Medicine, Environmental Studies, Public Health, Social and Political Studies, Immunology, Microbiology, and Pharmacology could all provide important contributions that aim to reduce the occurrence of factors governing the spread of emergent diseases. PMID:25520950

  20. [Vertebrate mortality in the Guanare-Guanarito road, Portuguesa state, Venezuela].

    PubMed

    Seijas, Andrés Eloy; Araujo-Quintero, Alexis; Velásquez, Nadines

    2013-12-01

    Roads directly or indirectly affect the structure, dynamics and function of ecosystems that they traverse. Most studies on the effect of roads on wildlife focus on the evaluation of mortality of vertebrates by vehicle collisions. Despite the extensive road network that exists in Venezuela, studies of wildlife mortality in them are scarce. In this paper, we analyzed the temporal and spatial pattern of vertebrate's collisions along the road Guanare-Guanarito, in Portuguesa state. We travelled 26 times between these towns (74 km) to localize dead vertebrates, at a speed of 50-60km/h. of those trips were conducted from March 13 to October 26, 2010, and 10 additional trips from December 7, 2009 to December 14, 2010; these ones, with the aim to include months and seasons that were insufficiently sampled during the first period. The elapsed time between trips varied from 14 to 37 days. The total distance traveled was 1 924 km. Dead animals found amounted 464 individuals, 66 of them were birds (25 identified species), 130 mammals (15 species) and 268 reptiles (18 species). The species with the highest number of individuals were the snake Leptodeira annulata (n=119), the oppossum Didelphis marsupialis (n=39) and the spectacled caiman Caiman crocodilus (n=33). Excluding domestic animals, the rate of road-killed vertebrates was 0.2282 indiv./km, a figure 28.3% higher than previous studies in the same road. Changes in the relative number of collisions for some species, respect to the numbers reported 20 years ago, were linked to the increase in traffic flow and changes in land use. Road segments with collision rates higher than expected by chance were identified. Collition by cars may be the principal cause of mortality for species like the tamandua (Tamandua tetradactyla) and the giant anteater (Myrmecophaga tridactyla), the last considered a vulnerable species. Some basic measures are proposed to reduce wildlife mortality on the road. PMID:24432523

  1. Chagas' disease: an emergent urban zoonosis. The caracas valley (Venezuela) as an epidemiological model.

    PubMed

    Urdaneta-Morales, Servio

    2014-01-01

    The unprecedented emergence of important public health and veterinary zoonoses is usually a result of exponential population growth and globalization of human activities. I characterized Chagas' disease as an emergent zoonosis in the Caracas Valley (Venezuela) due to the following findings: the presence of reservoirs (Didelphis marsupialis, Rattus rattus) and vectors (Panstrongylus geniculatus, Panstrongylus rufotuberculatus) infected with Trypanosoma cruzi in urbanized or marginalized areas; the elevated contact between P. geniculatus and human beings detected by parasitological and molecular examinations of triatomine feces demonstrated the possibility of transmission risks; a study of outbreaks of urban Chagas' disease reported the first proven case of oral transmission of T. cruzi to human beings; the risk of transmission of glandular metacyclic stages from marsupials by experimental ocular and oral instillation; mice genitalia infected with T. cruzi contaminated blood resulted in the formation of amastigotes very close to the lumen suggesting that there may be a possibility of infection via their release into the urine and thence to the exterior; the ubiquitous histotropism and histopathology of T. cruzi was demonstrated using a mouse model; the presence of experimental T. cruzi pseudocysts in adipose, bone-cartilage, and eye tissue indicated a potential risk for transplants. Socio-sanitary programs that include improvements in housing, vector control, and access to medical treatment, as well as strategies aimed at combating social inequalities, poverty, and underdevelopment should be undertaken in those areas where zoonoses are most prevalent. Disciplines, such as Ecology, Epidemiology, Medical Entomology, Human and Veterinary Medicine, Environmental Studies, Public Health, Social and Political Studies, Immunology, Microbiology, and Pharmacology could all provide important contributions that aim to reduce the occurrence of factors governing the spread of emergent diseases. PMID:25520950

  2. [Pesticide residues in drinking water of an agricultural community in the state of Mérida, Venezuela].

    PubMed

    Flores-García, Mery Elisa; Molina-Morales, Yuri; Balza-Quintero, Alirio; Benítez-Díaz, Pedro Rafael; Miranda-Contreras, Leticia

    2011-12-01

    The aim of this study was to determine the presence of pesticides in drinking water from six aqueducts in a region of intense agricultural activity in the state of Merida, Venezuela. The study was conducted for four continuous weeks, between May and June 2008. Pesticide residues were analyzed by solid phase extraction (SPE) and liquid chromatography (HPLC) with diode array detector (DAD). The method SPE-HPLC-DAD met the criteria of analytical validation, with good linearity (R2: 0.9840 to 0.9999), precision (coefficient of inter-day variability from 1.47 to 6.25%), accuracy (relative standard deviation 0.9 to 9.20%) and sensitivity (LOD < or = 0.012 microg/L; LOQ < or = 0.030 microg/L, except mancozeb with 0.400 microg/L). Seven of the thirteen selected pesticides have a recovery rate between 100% and 70%, the rest between 61% and 37%. Ten pesticides of the following chemical groups, were detected in 72 samples analyzed: organophosphates, carbamates, triazines and urea derivatives. The pesticides with the highest frequency of detection were: carbofuran and atrazine (39%), malathion (25%), dimethoate and metribuzin (19%). The pesticides found at high levels were diazinon (26.31 microg/L), methamidophos (10.99 microg/L), malathion (2.03 microg/L) and mancozeb (1.27 microg/L). Pesticide levels did not exceed the maximum allowed by Venezuelan law, however, according to international standards (EU and EPA-USA) values were above the maximum permissible levels. This study demonstrates the urgent need for systematic monitoring of the quality of water for human consumption in regions of high agricultural productivity. PMID:22523840

  3. Insecticide impregnated curtains to control domestic transmission of cutaneous leishmaniasis in Venezuela: cluster randomised trial

    PubMed Central

    Kroeger, Axel; Avila, Elci Villegas; Morison, Linda

    2002-01-01

    Objective To measure the impact on transmission of leishmaniasis of curtains impregnated with insecticide. Design Cluster randomised controlled trial: household interview survey, observational study of people's behaviour, entomological study with light trap captures of sandflies inside houses. Setting 14 urban sectors in Trujillo, Venezuela. Participants 2913 inhabitants of 569 houses. Intervention Sectors were paired according to their 12 month cumulative incidence of cutaneous leishmaniasis, one sector in each pair was randomly allocated to receive polyester curtains impregnated with lambdacyhalothrin (intervention group) while the other sector received curtains without insecticide or no curtains (control groups). After 12 months a follow up household survey was conducted. Main outcome measures Reduction in abundance of sandflies indoors and 12 month incidence of clinical cases of cutaneous leishmaniasis. Results Transmission of cutaneous leishmaniasis occurred mainly in the domestic setting, with the incidence over 12 months of 4%. The mean number of sandflies per trap per night was 16. After follow up the 12 month incidence of cutaneous leishmaniasis was 0% in the intervention group and 8% in the six pairs in the control group that received unimpregnated curtains (mean difference 8, 95% confidence interval 4.22 to 11.78; P=0.001). There were significantly fewer sandflies in the intervention group (2 v 15, mean difference 13 sandflies per trap; 9 to 17; P<0.001). Conclusion Curtains impregnated with insecticide provide a high degree of protection against indoor transmission of cutaneous leishmaniasis. What is already known on this topicThe transmission of cutaneous leishmaniasis is increasingly in urban and domestic settingsHouse spraying, space spraying, and insecticide treated material reduce the number of vectorsWhat this paper addsPyrethroid impregnated curtains can considerably reduce the incidence rate of cutaneous leishmaniasis in areas where indoor transmission is predominant PMID:12376442

  4. Dynamic controls on accretion and lithification of modern gypsum-dominated thrombolites, Los Roques, Venezuela

    NASA Astrophysics Data System (ADS)

    Petrash, Daniel A.; Gingras, Murray K.; Lalonde, Stefan V.; Orange, François; Pecoits, Ernesto; Konhauser, Kurt O.

    2012-03-01

    Meter-sized thrombolites coated by well developed zonally differentiated microbial mats have been found growing in the shallow waters (depth < 1 m) of a restricted hypersaline lagoon on the Archipelago Los Roques in Venezuela. By contrast, within the deeper parts of the studied lagoon, sedimentation is characterized by several decimeters of organic-rich material containing gypsum granules lacking carbonate cementation. The lithification of the thrombolites is thought to have proceeded as follows. First, extracellular polymeric substances (EPS) comprising the microbial mat concentrate Ca2 + and other metal cations by adsorption from the hypersaline waters. Second, some of these bound metals then serve as nucleation sites for primary calcium carbonate (CaCO3) precipitation. Third, while carbonate phases are forming in some zones of the mat, in others zones they are being re-dissolved due to the acidity generated through the metabolism of sulfide-oxidizing bacteria, Fourth, as the dissolved sulfide is oxidized into sulfate, the pore-water become saturated with respect to gypsum (CaSO4·2H2O). Fifth, as primary gypsum precipitates within the structures, endolithic sulfate-reducing bacteria metabolize the sulfate moiety in the mineral phase, while simultaneously oxidizing the EPS trapped during accretion. Sixth, as microbial EPS degradation proceeds, the anaerobic oxidation of specific protein fractions of the EPS matrix leads to increased alkalinity, the partial dissolution of gypsum, supersaturation with respect to calcium carbonate, and ultimately pseudomorphic aragonite replacement; this differs from secondary calcite cements in being enriched in 12C, and depleted in minor and trace metals initially associated with the EPS. The biogeochemical processes occurring in this thrombolite-constructing lagoon represent a novel field site for studying the chemical and isotopic processes characterizing early diagenetic gypsum and the role microbes play in its precipitation, dissolution and calcification. In this regard, insights gained from this modern field site will help to better understand mechanisms by which some Precambrian microbialites were lithified.

  5. Ecoepidemiological and Social Factors Related to Rabies Incidence in Venezuela during 2002-2004

    PubMed Central

    Rifakis, Pedro M.; Benitez, Jesus A.; Rodriguez-Morales, Alfonso J.; Dickson, Sonia M.; De-La-Paz-Pineda, Jose

    2006-01-01

    Rabies in Venezuela has been important in last years, affecting dogs, cats, and human, among other animals, being a reportable disease. In Zulia state, it is considered a major public health concern. Recently, a considerable increase in the incidence of rabies has been occurring, involving many epidemiological but also ecoepidemiological and social factors. These factors are analyzed in this report. During 2002-2004, 416 rabies cases were recorded. Incidence has been increasingly significantly, affecting mainly dogs (88.94%). Given this epidemiology we associated ecoepidemiological and social factors with rabies incidence in the most affected state, Zulia. In this period 411 rabies cases were recorded. Zulia has varied environmental conditions. It is composed mostly of lowlands bordered in the west by mountain system and in the south by the Andes. The mean is temperature 27.8°C, and mean yearly rainfall is 750 mm. Climatologically, 2002 corresponded with El Niño (drought), middle 2003 evolved to a Neutral period, and 2004 corresponded to La Niña (rainy); this change may have affected many diseases, including rabies. Ecological analysis showed that most cases occurred in lowland area of the state and during rainy season (p<0.05). Additionally, there is an important social problem due to educational deficiencies in the native population. Many ethnic groups live un Zulia, many myths about rabies are in circulation, and the importance of the disease is not widely realized. The full scale of the rabies burden is unknown, owing to inadequate disease surveillance. Although there have been important advances in our knowledge and ability to diagnose and prevent it, enormous challenges remain in animal rabies control and provision of accessible-appropriate human prophylaxis worldwide. Human and animal surveillance including ecological and social factors is needed. PMID:23674960

  6. Asymmetrical and heterogeneous elasto-static deformation along the El Pilar Fault in Northeastern Venezuela

    NASA Astrophysics Data System (ADS)

    Reinoza, C.; Jouanne, F.; Audemard, F. A.; Beck, C.

    2013-05-01

    Velocities field in both sides of the El Pilar fault, the most important right-lateral strike-slip fault of the Caribbean-South America plate boundary, present an important asymmetry. This pattern suggests a change in elastic properties when crossing the fault. We have applied an asymmetric model to simulate observed velocities with 20 mm/yr creep at depth, corresponding at the relative velocity of Caribbean plate versus South America plate. The preferred model indicated a shallow locking depth at 4.5 km. In a second part, a near-fault low-rigidity compliant zone from 3 km of depth with a 30 per cent of rigidity reduction respect to the environment is proposed using a 3D elasto-static model. We use GPS data from 23 stations collected in 2002 and 2005 like input parameters as well as geometry parameters based in previous work. The shallow locking depth and the interseismic velocities used in the asymmetry and compliant zone models respectively support: i) the hypothesis of a partially locked seismogenic upper part, ii) the concentration of the Caribbean- South America relative displacement entirely along the El Pilar Fault. Reinoza Carlos PhD thesis and stay in ISTerre Laboratory is funded through Venezuela's FUNDAYACUCHO Grant N° 756514C. This research is a contribution to FONACIT-ECOS Nord grant 2009000818 (French code V10U01). Observed velocities (white) from 2002 and 2005 GPS campaign measurements data with error ellipses drawn for 66% confidence level expressed in the South America plate reference frame.

  7. [Growth and mortality parameters of Orthopristis ruber (Perciformes: Haemulidae) from Los Frailes Archipelaeo. Venezuela].

    PubMed

    Atenas, Guerrieri; Eslava, Nora; González, Leo Walter; Guevara, Francisco

    2015-03-01

    Orthopristis ruber is a species in high demand in Eastern Venezuela, but production has been decreasing in recent years. For this reason, our objective was to estimate the growth and mortality parameters of this resource. Monthly samples were collected from June 2011 to May 2012, obtaining 2980 specimens in El Tirano and Puerto Abajo. Data on total length (cm), total weight (g), and sex were recorded for each specimen. No sexual dimorphism was shown with respect to length (t(S)=1.113, p>0.05), so one length-weight ratio was established for both sexes (Wt=0.0612*Lt(2.54)); and they both exhibited minor allometric growth. Growth was estimated by analysis of length frequency distributions using FiSAT software. The estimated growth parameters (L.=39.03cm, W.=679.60g, k=0.48/year and t(O) = -0.32 year) showed moderately rapid growth. Length frequency data were adjusted to the von Bertalaniffy model, and indicated an exponential tendency of accelerated growth during the first years of life, followed by slow growth until the fish reached its maximum length. The coefficient of variation of the growth index (theta) demonstrated no differences in growth pattern. The natural mortality rate (M=0.97/year), from fishing (F=1.57/year), and total mortality (Z=2.54/year), were high, as well as the exploitation rate (E=0.62/year). We concluded that O. ruber has been fully exploited by artisanal fishers, and suggest a continuous study on population dynamics, to recommend optimum management techniques for the fishery. PMID:26299124

  8. Cenozoic transpressional model for the tectonic and basinal development of Venezuela and Trinidad

    SciTech Connect

    Pindell, J.L. ); Dewey, J.F. )

    1991-03-01

    Geological features and plate tectonic constraints are integrated to outline a revised model for the Jurassic to Recent development of northern South America east of Guajira Peninsula. Development appears controlled by NoAm/SoAm and Carib/SoAm relative motions. Main phases were: (1) Jurassic rifting; (2) Late Jurassic - Maestrichtian passive margin sedimentation; (3) Eocene-Recent north-vergent understanding of Proto-Caribbean (Atlantic) crust beneath Venezuela; (4) eastwardly progressive Cenozoic south-vergent dextral transpression between northern South America and the Pacific-derived Caribbean Plate, and obduction of Caribbean terranes onto SoAm; (5) Neogene-Recent north-vergent underthrusting of Caribbean crust beneath the Guajira, Paraguana, and ABC (Aruba-Bonaire-Curacao-Orchila) terranes. Compressional and transcurrent sedimentary basins were developed in Cenozoic time in response to Carib-SoAm relative motion and terrane obduction, above rocks of the pre-existing Jurassic-Cretaceous passive shelf. Although Jurassic rift-related petroleum source rocks may have been deposited locally, primary source rocks are Upper Cretaceous and were deposited well after Jurassic rifting such that they were not affected by rift-related heat. In the absence of Cretaceous volcanism, geothermal gradients may be assumed to have been fairly normal. Maturation was thus a function of depth of burial, which was insufficient in each basin until Cenozoic basin development. A second phase of rapid deposition and hence maturation of Neogene age has occurred in inter-Andean basins of the west (e.g., Maracaibo) due to Miocene uplift and erosion of Andean ranges. These predicted maturation times are corroborated by more direct studies.

  9. Sources of ?15N variability in sinking particulate nitrogen in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Montes, Enrique; Thunell, Robert; Muller-Karger, Frank E.; Lorenzoni, Laura; Tappa, Eric; Troccoli, Luis; Astor, Yrene; Varela, Ramón

    2013-09-01

    Ten years of monthly observations of the ?15N of sinking particulate nitrogen (?15N-PN (in ‰ versus atmospheric N2)=[(15N/14N)sample/(15N/14N)standard)-1]1000) in the Cariaco Basin, Venezuela, confirm that the basin's bottom sediments store information about nitrogen dynamics related to seasonal and interannual variability in regional surface ocean processes. During the upwelling period of the southern Caribbean Sea (February-April), the ?15N-PN is similar to that of the thermocline nitrate (˜3.5‰). This nitrate is imported into the Cariaco Basin with Subtropical Underwater (SUW), which wells up near the coast. Thus, particles generated by phytoplankton photosynthesis during this productive period bear a sub-tropical North Atlantic isotopic imprint of N2 fixation (low compared to the global average of nitrate ?15N?5‰). During the non-upwelling period when surface waters are stratified (September-November), the ?15N-PN is also 3.5-4.0‰, and reflects a mixture of local N2 fixation within the mixed layer, inputs of terrigenous organic matter and SUW nitrate consumption by phytoplankton below the mixed layer, which most likely exerts the strongest control on the ?15N-PN signal during this time. In the transition periods of May-July and December-January, the ?15N-PN increases to 4.5-6.5‰. This coincides with maxima of continental material fluxes (terrestrial PON ?15N is >6‰) into the Cariaco Basin. The ?15N signal in the sediments of the Cariaco Basin thus provides information about the relative strength of the local coastal upwelling, the relative input of continental material via river runoff, and local N2 fixation. The findings contribute to interpretations of the basin's paleoclimatic nitrogen cycle variations based on observations of the sedimentary ?15N record at this location.

  10. Geodetic exploration of strain along the El Pilar Fault in northeastern Venezuela

    NASA Astrophysics Data System (ADS)

    Reinoza, C.; Jouanne, F.; Audemard, F. A.; Schmitz, M.; Beck, C.

    2015-03-01

    We use Global Navigation Satellite Systems observations in northeastern Venezuela to constrain the El Pilar Fault (EPF) kinematics and to explore the effects of the variable elastic properties of the surrounding medium and of the fault geometry on inferred slip rates and locking depth. The velocity field exhibits an asymmetric velocity gradient on either side of the EPF. We use five different approaches to explore possible models to explain this asymmetry. First, we infer a 1.6 km locking depth using a classic elastic half-space dislocation model. Second, we infer a 1.5 km locking depth and a 0.33 asymmetry coefficient using a heterogeneous asymmetric model, including contrasting material properties on either side of a vertical fault, suggesting that the igneous-metamorphic terranes on the northern side are ~2 times more rigid than the sedimentary southern side. Third, we use a three-dimensional elastostatic model to evaluate the presence of a compliant zone, suggesting a 30% reduction of rigidity in the upper 3 km at the depth of a 1 to 5 km wide fault zone. Fourth, we evaluate the distribution of fault slip, revealing a widespread partial creep pattern in the eastern upper segment, while the upper western segment exhibits a partially locked area, which coincides with the rupture surface of the 1797 and 1929 earthquakes. To supplement these models, we upgrade the previously published displacement simulation method using nonvertical dislocations with data acquired between 2003 and 2013. The localized aseismic displacement pattern associated with creeping or partially creeping fault segments could explain the low level of historic seismicity.

  11. Lithospheric expression of cenozoic subduction, mesozoic rifting and the Precambrian Shield in Venezuela

    NASA Astrophysics Data System (ADS)

    Masy, Jeniffer; Niu, Fenglin; Levander, Alan; Schmitz, Michael

    2015-01-01

    We have combined surface wave tomography with Ps and Sp receiver-function images based on common-conversion-point (CCP) stacking to study the upper mantle velocity structure, particularly the lithosphere-asthenosphere boundary (LAB), beneath eastern and central Venezuela. Rayleigh phase velocities in the frequency range of 0.01-0.05 Hz (20-100 s in period) were measured using the two-plane-wave method and finite-frequency kernels, and then inverted on a 0.5° × 0.5° grid. The phase velocity dispersion data at grid points were inverted for 1D shear velocity profiles using initial crust-mantle velocity models constructed from previous studies. The 3D velocity model and receiver-function images were interpreted jointly to determine the depth of the LAB and other upper mantle features. The tomographic images revealed two high velocity anomalies extending to more than ?200 km depth. One corresponds to the top of the subducting Atlantic plate beneath the Serrania del Interior. The other anomaly is a highly localized feature beneath the Maturin Basin. The LAB depth varies significantly in the study region: It is located at ?110 km depth beneath the Guayana Shield, and reaches ?130 km at the northern edge of the Maturin Basin, which might be related to the downward flexural bending due to thrust loading of the Caribbean plate and pull from the subducting Atlantic plate. Immediately to the west, the lithosphere is thin (?50-60 km) along the NE-SW trending Espino Graben from the Cariaco basin to the Orinoco River at the northern edge of the craton. The LAB in this region is the top of a pronounced low velocity zone. Westward, the lithosphere deepens to ?80 km depth beneath the Barinas Apure Basin, and to ?90 km beneath the Neogene Merida Andes and Maracaibo block. Both upper mantle velocity structure and lithosphere thickness correlate well with surface geology and are consistent with northern South American tectonics.

  12. Distribution and species diversity of deep-sea nematodes in the Venezuela Basin

    NASA Astrophysics Data System (ADS)

    Tietjen, John H.

    1984-02-01

    In three sedimentary regions in the deep (>3400 m) Venezuela Basin, nematode abundance and dry weight biomass (ean ±1 S.E.) were higher in hemipelagic sediments (94 ± 1.5 individuals, 88 ± 2.5 ?g per 10 cm -2) than in pelagic (67 ± 3 individuals, 32 ±33 ?g per 10 cm -2) or turbidite (36 ± 3 individuals, 30 ± 3 ?g per 10 cm -2) sediments. Abundance of nematodes appears to be at least partially related to geographic position within the basin; hemipelagic sediments lie closer to an area of elevated surface production near the Lesser Antilles than do the pelagic or turbidite sediments. Abundance of nematodes is also directly correlated with macrofauna abundance and presence of sedimentary lipids. Normal hierarchical classification indicates the presence of two faunal groups in the sediments: a 'sand' fauna in coarser pelagic sediments (median grain size, 65 ?m) and a 'silt-clay' fauna in the finer hemipelagic and turbidite sediments (median grain size in both, 0.65 ?m). Animals among the two faunal groups differ mostly in their feeding morphology: selective deposit feeding species, unable to utilize large, pelagically derived particles (mainly foraminiferan tests) are more abundant in finer hemipelagic and turbidite sediments, whereas species capable of rasping food particles off large sedimentary particles (epistrate feeders) are more abundant in pelagic sands than in finer sediments. Species diversity is higher in the hemipelagic than turbidite and pelagic sediments. Two reasons postulated for this are (1) the possible input of relatively fresh, surface-derived organic matter that might permit a large number of species to exist in hemipelagic sediments than in the other two, and (2) an optimally heterogeneous grain size distribution that might allow the species to coexist equitably. All three sediments support more diverse nematode assemblages than those in the North Carolina slope region, probably reflecting the greater physical stability of the abyssal than bathyal sea floor.

  13. Dirio Econmico -Universidades Como ser investigador em Portugal

    E-print Network

    Instituto de Sistemas e Robotica

    Diário Económico - Universidades Como é ser investigador em Portugal Autor: N.D. Editora: ST e SF - Universidades Como é ser investigador em Portugal Autor: N.D. Editora: ST e SF Id: 1646658 Data Publicação: 19

  14. Comparison of Petrophysical Rock Types from Core and Well-logs using Post-stack 3D Seismic Data: Field Example from Maracaibo-Venezuela

    E-print Network

    Ramachandran, Kumar

    Comparison of Petrophysical Rock Types from Core and Well-logs using Post-stack 3D Seismic Data with post stack 3D seismic data analysis was used to assess the petrophysical rock type distribution in an area located on the West side of Lake Maracaibo-Venezuela. The calculated petrophysical rock types were

  15. A reservoir engineering characterization of the north study area of the C2/VLE-305 reservoir, Lamar Field, Lake Maracaibo, Venezuela 

    E-print Network

    Padron Cabral, Ricardo Javier

    1994-01-01

    on the C2/VLE-305 reservoir unit in Lake Maracaibo, Venezuela and is used to illustrate the application of our modified FZI parameter. Our target reservoir member is the C2 unit which has been divided into five "flow units" (C20, C21 S, C211, C22 and C23...

  16. First Description of KPC-2-Producing Klebsiella oxytoca Isolated from a Pediatric Patient with Nosocomial Pneumonia in Venezuela

    PubMed Central

    Labrador, Indira

    2014-01-01

    During the last decade, carbapenem resistance has emerged among clinical isolates of the Enterobacteriaceae family. This has been increasingly attributed to the production of ?-lactamases capable of hydrolyzing carbapenems. Among these enzymes, Klebsiella pneumoniae carbapenemases (KPCs) are the most frequently and clinically significant class-A carbapenemases. In this report, we describe the first nosocomial KPC-2-producing K. oxytoca isolated from a pediatric patient with pneumonia admitted to the intensive care unit at The Andes University Hospital, Mérida, Venezuela. This strain was resistant to several antibiotics including imipenem, ertapenem, and meropenem but remained susceptible to ciprofloxacin, colistin, and tigecycline. Conjugation assays demonstrated the transferability of all resistance determinants, except aminoglycosides. The isolate LMM-SA26 carried a ~21?kb conjugative plasmid that harbored the blaKPC-2, blaCTX-M-8, and blaTEM-15 genes. Although carbapenem resistance in the Enterobacteriaceae is still unusual in Venezuela, KPCs have a great potential to spread due to their localization on mobile genetic elements. Therefore, rapid detection of KPC-carrying bacteria with phenotypic and confirmatory molecular tests is essential to establish therapeutic options and effective control measures. PMID:25405043

  17. Evaluation of GO_CONS_GCF_2_TIM and GOCO01S Geopotential Models in Venezuela and Caribbean Region

    NASA Astrophysics Data System (ADS)

    Orihuela, N. D.; Garcia, A. D.; Tabare, T.; Scientific Team Of Venezuelan; Caribbean Crustal Study From Satellital Data

    2010-12-01

    This paper shows two maps of the magnitude of the surface gravity vector (MSGV) of Venezuela and Caribbean region at 1:500.000 scale in the geographic window between the 0-20 north latitude and 74-58 western longitude (Fig. 1 and Fig. 2), that were generated from GOCE gravity gradients data provided by the European Space Agency (ESA). The maps that are showed come from the combined global gravity field model GOCO01s [GOCO Consortium., 2010] and from the satellite-only global gravity field model GO_CONS_GCF_2_TIM [Pail et al., 2010], both of 224 degree. The DEMs used for the evaluation of the MSGV are: Etopo2v2 [NGDC., 2006] and Etopo1 [Amante and Eakins, 2009] respectively. The data processing was done using: Shm2func [ICGEM., 2007]; Goce User Toolbox [ESA., 2009]; Gravsoft package [Tscherning et al., 1992] and Oasis Montaj (Geosoft). This research shows a review of observed gravity in the main geological provinces of the Venezuela and Caribbean region geography, revealing gravitational features important of the geological structures that are in Venezuelan and Caribbean subsurface.

  18. Dengue Seroprevalence and Risk Factors for Past and Recent Viral Transmission in Venezuela: A Comprehensive Community-Based Study

    PubMed Central

    Velasco-Salas, Zoraida I.; Sierra, Gloria M.; Guzmán, Diamelis M.; Zambrano, Julio; Vivas, Daniel; Comach, Guillermo; Wilschut, Jan C.; Tami, Adriana

    2014-01-01

    Dengue transmission in Venezuela has become perennial and a major public health problem. The increase in frequency and magnitude of recent epidemics prompted a comprehensive community-based cross-sectional study of 2,014 individuals in high-incidence neighborhoods of Maracay, Venezuela. We found a high seroprevalence (77.4%), with 10% of people experiencing recent infections. Multivariate logistic regression analysis showed that poverty-related socioeconomic factors (place and duration of residence, crowding, household size, and living in a shack) and factors/constraints related to intradomiciliary potential mosquito breeding sites (storing water and used tires) were linked with a greater risk of acquiring a dengue infection. Our results also suggest that transmission occurs mainly at home. The combination of increasingly crowded living conditions, growing population density, precarious homes, and water storage issues caused by enduring problems in public services in Maracay are the most likely factors that determine the permanent dengue transmission and the failure of vector control programs. PMID:25223944

  19. Dengue seroprevalence and risk factors for past and recent viral transmission in Venezuela: a comprehensive community-based study.

    PubMed

    Velasco-Salas, Zoraida I; Sierra, Gloria M; Guzmán, Diamelis M; Zambrano, Julio; Vivas, Daniel; Comach, Guillermo; Wilschut, Jan C; Tami, Adriana

    2014-11-01

    Dengue transmission in Venezuela has become perennial and a major public health problem. The increase in frequency and magnitude of recent epidemics prompted a comprehensive community-based cross-sectional study of 2,014 individuals in high-incidence neighborhoods of Maracay, Venezuela. We found a high seroprevalence (77.4%), with 10% of people experiencing recent infections. Multivariate logistic regression analysis showed that poverty-related socioeconomic factors (place and duration of residence, crowding, household size, and living in a shack) and factors/constraints related to intradomiciliary potential mosquito breeding sites (storing water and used tires) were linked with a greater risk of acquiring a dengue infection. Our results also suggest that transmission occurs mainly at home. The combination of increasingly crowded living conditions, growing population density, precarious homes, and water storage issues caused by enduring problems in public services in Maracay are the most likely factors that determine the permanent dengue transmission and the failure of vector control programs. PMID:25223944

  20. Venezuela-MEM/USA-DOE Fossil Energy Report IV-11: Supporting technology for enhanced oil recovery - EOR thermal processes

    SciTech Connect

    Venezuela

    2000-04-06

    This report contains the results of efforts under the six tasks of the Tenth Amendment anti Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Energy Agreement. This report is presented in sections (for each of the six Tasks) and each section contains one or more reports that were prepared to describe the results of the effort under each of the Tasks. A statement of each Task, taken from the Agreement Between Project Managers, is presented on the first page of each section. The Tasks are numbered 68 through 73. The first through tenth report on research performed under Annex IV Venezuela MEM/USA-DOE Fossil Energy Report Number IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, IV-8, IV-9, IV-10 contain the results of the first 67 Tasks. These reports are dated April 1983, August 1984, March 1986, July 1987, November 1988, December 1989, October 1991, February 1993, March 1995, and December 1997, respectively.

  1. The preliminary results of the measurements of environmental levels of 40K and 137Cs in Venezuela

    NASA Astrophysics Data System (ADS)

    LaBrecque, J. J.; Rosales, P. A.; Carias, O.

    1992-02-01

    The study of the beta-particle radioactivity in air and 90Sr in rainwater collected at Instituto Venezolano de Investigaciones Cientificas, IVIC, that began in 1959 in conjunction with the U.S. Atomic Energy Commission was discontinued in 1963. But after the Chernobyl nuclear power plant accident in the USSR, work on the radioactive contamination in Venezuela has been renewed. Initially the measurement of 134Cs and 137Cs in imported foodstuffs, such as milk powders and meats were undertaken, and these have now been extended to measurements of environmental levels of 40K and 137Cs in soils, sea sediments and foodstuffs. The data present herein are the only readily available data on radioactive contamination in the environment in Venezuela since 1963. The measurements were performed with a simple Nal(Tl) detector and two single channel analyzers as well as with a 25% efficient hyper-pure germanium semiconductor coupled to a multichannel analyzer system. Finally, these results can be used as baseline values (environmental background) in case of a nuclear accident in the region, as well as to screen imported foodstuff which is suspected to be contaminated.

  2. Respuesta Multiespectral de la Vegetacin Circundante de Canales Naturales como Posible Fuente de Identificacin de Corrientes

    E-print Network

    Gilbes, Fernando

    componente de los ecosistemas, el estado en que estos se encuentren puede determinar el estado de una zona o de agua en los canales primarios en las redes hídricas y sus ecosistemas son de gran importancia para

  3. Como Lo Hago Yo: Mielomeningocele En Bolivia

    PubMed Central

    Dabdoub, Carlos F.; Dabdoub, Carlos B.; Villavicencio, Ramiro; Quevedo, Germán

    2014-01-01

    Introducción: Las malformaciones del tubo neural (MTN) representan la segunda causa más frecuente de anomalías congénitas, luego de las cardiopatías. En este grupo se destaca el mielomeningocele (MMC) por su mayor incidencia, y por ser la más incapacitante y la más compleja entre todas las demás malformaciones del sistema nervioso c`entral (SNC). En Bolivia, como en muchos países de Sudamérica, los bajos niveles socio-culturales y la debilidad en el sistema sanitario, hacen que su incidencia y su morbilidad, sean mayores que en las naciones más desarrolladas. Material y Métodos: Se realizó un estudio retrospectivo y descriptivo de 70 casos de MMC, atendidos por un equipo multidisciplinario en el Hospital Universitario Japonés (HUJ) de Santa Cruz de la Sierra, entre 2008-2011. De ellos, 60 fueron intervenidos quirúrgicamente. Resultados: Se realizaron controles prenatales sólo en 27 mujeres (38.6%), diagnosticándose una disrafia espinal en apenas dos casos (7.4%). La edad de ingreso del MMC en su mayoría fue después de las 24 horas (65.6%), predominando su localización en la región lumbosacra (64.3%). De ellos, 67.2% eran abiertos, presentando un 32.9% un daño neurológico motor parcial mientras que 47.1% tenían paraplejia por debajo de la lesión. De los 70 casos, tres (4.3%) no fueron intervenidos, por presentar defectos congénitos severos o estado general grave. Las principales complicaciones posoperatorias inmediatas fueron: dehiscencia de sutura y/o infección de la herida (16.6%), fístula de líquido cefalorraquídeo (LCR) (10%) e infección del SNC (11.7%). La mortalidad general y postoperatoria fue de 7.1% y 3.3%, respectivamente. Al mes de vida presentaban hidrocefalia un 80% de los pacientes operados, colocándose una derivación ventriculoperitoneal (DVP) de presión media. De 9 pacientes que tuvieron un acompanamiento de dos o más años, seis presentaron una médula anclada, que fueron intervenidas quirúrgicamente. Conclusión: En esta serie, el diagnóstico prenatal del MMC fue ocasional y la derivación al HUJ de los recién nacidos con esta malformación fue generalmente tardía. No hubo predominio de género y la mayoría de los casos presentaron sus lesiones en la región lumbar y lumbosacra. La mortalidad general y postoperatoria fue similar a la reportada en la literatura. Pocos enfermos realizaron controles posteriores al alta hospitalaria. Igual que otros países de Sudamérica, las falencias en el sistema público de salud y el nivel sociocultural, son factores determinantes para un mal pronóstico en estos niños. Por sus múltiples complicaciones, el MMC requiere de una especial atención gubernamental, sobre todo de carácter preventivo mediante el uso de ácido fólico en mujeres fértiles, como también de un equipo profesional multidisciplinario, a fin de realizar un tratamiento adecuado y oportuno. Al mismo tiempo, trabajos multicéntricos en hospitales de América Latina, ayudarán al mejor manejo de estos pacientes. PMID:24791220

  4. Geochemical study of products associated with spontaneous oxidation of coal in the Cerro Pelado Formation, Venezuela

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Márquez, G.; Alejandre, F. J.; Del Río, J. J.; Hurtado, A.

    2009-02-01

    The aim of this research work is a geochemical, mineralogical, and textural characterization of spontaneously smouldered coal-derived products in northwestern Venezuela (Cerro Pelado Formation, some 10 km from Pedregal city). Several solid samples were collected from this formation, six of unweathering coal, an other six of resulting unmelted rocks forming on a surface coal bed, and the last four of mineralizations found accumulating around gas vents. The fresh coal and the unmelted material were analysed by scanning electron microscopy, X-ray diffraction, and proximate techniques. Products such as magnetite and chabazite-K were identified in the alteration rocks. Likewise, both materials were also studied in order to determine the mobilization of 17 elements into the environment; such elements were analysed through inductively coupled plasma atomic emission spectroscopy on extracts obtained by a sequential extraction method: each sample was firstly extracted with MilliQ water and then the resultant residue was washed. This and the subsequently resulting residues are extracted according to the mentioned procedure by using, respectively, ammonium acetate, chlorhydric acid, peroxide and chlorhydric acid, nitric acid and fluorhydric acid, and nitric acid. The studied elements are classified as highly mobile (Na, Ni, ...), nearly immobile (Ti, P) and partially mobile (Mg, Fe, K, ...). In regards to mineralizations around fumaroles associated with smoldering coal seams, Fourier-transform infrared spectroscopy and X-ray diffraction analyses have revealed the presence of salammoniac, mascagnite and other solid combustion compounds formed by reaction of gas emitted from coal oxidation, in addition to previously non-reported sulfur-rich by-products associated with gas fissures, particularly ammonium thiosulfate, a phase first obtained only synthetically in the laboratory. Another objective of the research was to collect and analyse gases escaping from surficial vents. Relatively high concentrations of several aromatic compounds were detected in the gas collected at the studied coal outcrop, as well as aliphatic hydrocarbons including ethane, propane, butanes, among others. High contents of carbon monoxide, methane and carbon dioxide were also measured for gas samples.

  5. Paleoseismicity studies on the Oca-Ancón fault system, northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A. M.

    1996-06-01

    The E-W-trending, right-lateral Oca-Ancón fault system extends eastward for 650 km, from the Colombian Caribbean coast near the city of Santa Marta to the town of Boca de Aroa (located on the eastern coast of Falcón State, northwestern Venezuela), across the Goajira peninsula, the outlet of Lake Maracaibo, the coastal plains of Buchivacoa and the central Falcón range. This system is very conspicuous west of the city of Maracaibo where its single trace sharply truncates the northern ends of the Santa Marta block and the Perijá range. Fault-related landforms along the system trace (e.g., displaced beach strandlines at Sinamaica and fault scarplets in the Buchivacoa plains) suggest that it may have been active during Holocene times. A first trenching attempt carried out north of Maracaibo (at Sinamaica) in 1969 only confirmed its Holocene tectonic activity. On the western coastal plains of Falcón State and east of Lake Maracaibo, the system is less simple as it is composed of two parallel fault strands but they are clearly evidenced by Holocene paleoseismic scarplets. Recently, this system has been paleoseismically evaluated by means of two trenches placed across each of the two parallel branches known as the Oca and the Ancón faults. Dimensions of these bulldozer-dug trenches are 80 m long and 8 m deep. Various lines of evidence obtained from these exploratory trenches indicate that: (a) three surface rupture events, dated slightly prior to 7755 ± 320, 6240 ± 39 and 1945 ± 630 yr B.P., have occurred along the Oca fault; (b) one surface rupture event has occurred within the past 3125 ± 185 yr on the Ancón fault; (c) the Holocene slip rate of the system is close to 2 mm/yr; and (d) either of the faults can generate a maximum event of magnitude 7.4-7.5 Recurrence of such earthquakes on the Ancón fault is close to 1900 years while it is about 4300 years on the Oca fault.

  6. Suboxic dolomite formation linked to the sedimentary Mn cycle, Archipelago Los Roques, Venezuela

    NASA Astrophysics Data System (ADS)

    Petrash, D.; Lalonde, S.; Gonzalez, G.; Gingras, M.; Konhauser, K.

    2013-12-01

    The preferential formation of Ca-rich dolomite precursors in modern peritidal environments has been associated with the degradation of buried microbial mats, with complexation of Ca and Mg cations by extracellular polysaccharides, and alkalinity generation, mostly through bacterial sulfate reduction. However, it remains unclear why Ca-dolomite would not occur in suboxic sediments where bacterial Mn(IV) and/or Fe(III) reduction are important sources of alkalinity, and the role, if any, of Fe- and Mn-recycling in its diagenetic stabilization to more stoichiometric dolomite is unknown. In a shoaling-upward parasequence in the Archipelago Los Roques, Venezuela, an abundance of Ca-dolomite coincides with a relative decrease in bulk-sediment iron concentrations. These sediments were analyzed with multiple analytical tools, including EPMA, ICP-MS, synchrotron-based XRF, XRD, and spatially resolved XANES. Results demonstrate that the distribution of spheroidal aggregates of nanometer-scale Ca-rich dolomite rhombohedra is linked with interstitial elemental sulfur and manganese accumulations, with Mn occurring in several oxidation states (Fig. 1). Based on our observations at this novel dolomite-forming site, we suggest that in peritidal settings the burial of metal-reactive microbial mats act as a barrier capable of concentrating dissolved reactive species that promote greater sediment residence times in suboxic (manganic) zones, where the recycling of Mn not only plays an important role in the remineralization of organic matter, but also sustains elevated alkalinity and dissolved pore water sulfide concentrations. The last two effects have been previously suggested to promote Mg dehydration, the major kinetic barrier to dolomite nucleation. Figure 1. Normalized Mn K-edge merged spectra of a 5 x 5 ?m analytical area bearing dolomite cements. A: The K-edge exhibits two main features at about 6554 and 6558 eV. B: Intermediate Mn (III) is identified by the positive slope of the first derivative of the XANES spectra in the interval 6547.9-6549.0 eV. C: A least-squares fitting of the spectra was performed to quantify the Mn species present. The spectra can be fitted with four model compounds, Mn2O3 (52.5 × 5.2%), MnCO3 (22.2 × 1.3%), gamma-MnOOH (15.0 × 5.0%), and Mn3O4 (10.3 × 7.7%), suggesting that these phases coexist in the dolomite-bearing microcrystalline cements.

  7. Low Child Survival Index in a Multi-Dimensionally Poor Amerindian Population in Venezuela

    PubMed Central

    Villalba, Julian A.; Liu, Yushi; Alvarez, Mauyuri K.; Calderon, Luisana; Canache, Merari; Cardenas, Gaudymar; Del Nogal, Berenice; Takiff, Howard E.; De Waard, Jacobus H.

    2013-01-01

    Background Warao Amerindians, who inhabit the Orinoco Delta, are the second largest indigenous group in Venezuela.  High Warao general mortality rates were mentioned in a limited study 21 years ago. However, there have been no comprehensive studies addressing child survival across the entire population. Objectives To determine the Child Survival-Index (CSI) (ratio: still-living children/total-live births) in the Warao population, the principal causes of childhood death and the socio-demographic factors associated with childhood deaths. Methods We conducted a cross-sectional epidemiological survey of 688 women from 97 communities in 7 different subregions of the Orinoco Delta. Data collected included socio-demographic characteristics and the reproductive history of each woman surveyed. The multidimensional poverty index (MPI) was used to classify the households as deprived across the three dimensions of the Human Development Index. Multivariable linear regression and Generalized Linear Model Procedures were used to identify socioeconomic and environmental characteristics statistically associated with the CSI. Findings The average CSI was 73.8% ±26. The two most common causes of death were gastroenteritis/diarrhea (63%) and acute respiratory tract Infection/pneumonia (18%).  Deaths in children under five years accounted for 97.3% of childhood deaths, with 54% occurring in the neonatal period or first year of life.  Most of the women (95.5%) were classified as multidimensionally poor.  The general MPI in the sample was 0.56.   CSI was negatively correlated with MPI, maternal age, residence in a traditional dwelling and profession of the head of household other than nurse or teacher. Conclusions The Warao have a low CSI which is correlated with MPI and maternal age.  Infectious diseases are responsible for 85% of childhood deaths.  The low socioeconomic development, lack of infrastructure and geographic and cultural isolation suggest that an integrated approach is urgently needed to improve the child survival and overall health of the Warao Amerindians.  PMID:24392022

  8. [Anatomy of the vegetative organs of two species of Atriplex (Chenopodiaceae) from Venezuela].

    PubMed

    Jáuregui, Damelis; Castro, Mercedes; Ruiz-Zapata, Thirza; Lapp, Marlene

    2014-12-01

    In Venezuela, Atriplex is represented by A. cristata and A. oestophora, the latter being endemic; they inhabit coastal areas with high temperatures, high solar radiation and sandy soils with high salt content. This work aimed to provide information to facilitate and clarify these species taxonomic delimitation, throughout the study of the anatomy of their vegetative organs; this may also clarify our understanding of their adaptability to soil and climatic conditions prevailing in areas they inhabit. The plant material was collected from at least three individuals of each species in Punta Taima Taima and Capatárida, Falcon. Segments of roots, located near the neck and towards the apex, apical, middle and basal internodes of stems, were taken; and of leaves, located in the middle portion of plants. This material was fixed in FAA (formaldehyde, acetic acid, 70% ethanol) until processing. Semipermanent and permanent microscope slides were prepared with transverse or longitudinal sections, made using a razor (free-hand) or a rotation microtome, in this latter case, after paraffin embedding; besides, additional plates were mounted with portions of leaf epidermis, obtained by the maceration technique. The sections were stained with aqueous toluidine blue (1%) or safranin-fast-green, and mounted in water-glycerin or in Canada balsam. In order to calculate the vulnerability index, the vessel diameter in the vascular rings of roots, as well as their density, were quantified. Our results revealed structural features in the different organs, that resulted of taxonomic value and allowed the distinction of the species: in the leaf, the presence of aquifer tissue, the number of vascular bundles and their organization in the midrib, and the collenchyma differentiation in this part of the leaf; in the roots, the xylem and phloem arrangement in the growth rings, the nature of conjunctive tissue, and the presence of included phloem in one species. In addition, the species showed typical anatomical features of halophytes and xerophytes, such as: high density of trichomes on leaves and young stems which act as salt secreting glands, abundant sclerenchyma in stems and roots, water storage tissue and Kranz anatomy in leaves, narrow cortical region in young roots, presence of cambial variants in stems and roots, as well as short and narrow xylem vessels. Vulnerability index calculations indicated that both species tend to assure conduction but not the efficiency of the system. Atriplex species have anatomical characters which facilitate their adaptation to the special conditions prevailing in their habitats and that may be used for taxonomic delimitation. PMID:25720192

  9. Oscillatory-zoned crystals of pyrochlore-group minerals from the Guaniamo kimberlites, Venezuela

    NASA Astrophysics Data System (ADS)

    Sharygin, Victor V.; Sobolev, Nikolai V.; Channer, Dominic M. DeR.

    2009-11-01

    Oscillatory-zoned crystals of pyrochlore-group minerals are found in the La Ceniza diamondiferous kimberlites, Guaniamo region, Venezuela. This is the first known occurrence of the pyrochlore-group minerals in kimberlites worldwide. The minerals occur in the kimberlite groundmass in association with olivine, zoned spinel, phlogopite, carbonates (dolomite, calcite, magnesite), apatite, tetraferriphlogopite, Fe-Ni-Cu-sulfides and serpentine. They form discrete octahedral crystals or intergrowths (up to 50 ?m) with a red-brown core and light brown rim. Individual zones in the cores are remarkably enriched in TiO 2 (up to 14.3 wt.%), Ta 2O 5 (up to 10.1 wt.%), ZrO 2 (up to 23.7 wt.%), ThO 2 (up to 22.3 wt.%) and UO 2 (up to 8.0 wt.%) at moderate Nb 2O 5 contents, whereas the outer regions contain significant CaO (up to 17.5 wt.%), Na 2O (up to 5.7 wt.%), Nb 2O 5 (up to 58.9 wt.%) and F (up to 4.6 wt.%), approaching the ideal formula (Na,Ca) 2Nb 2O 6F. Following the IMA recommendations and the "50% rule", the interior is classified as uranoan Zr-rich thoriobetafite/thoriopyrochlore or thorian Zr-rich betafite/pyrochlore, and the outer part as pyrochlore or thorian pyrochlore. Strong compositional zoning is consistent with two substitutions: 2(Th,U) 4+ + ? + (Ti,Zr) 4+ + O 2- ? 3Ca 2+ + Nb 5+ + (F,OH) - and 2(Th,U) 4+ + ? + 2(Ti,Zr) 4+ + O 2- ? 2Ca 2+ + Na + + 2Nb 5+ + (F,OH) -. The zoning patterns and the absence of perovskite indicate the dominant role of F among fluid components and relatively high alkalinity during crystallization of the silicate-carbonate groundmass of the La Ceniza kimberlite. The composition and zoning of the La Ceniza pyrochlore-group minerals are very specific, but in general strongly resemble those of some pyrochlores from carbonatites.

  10. Least Limiting Water Range of soils in the Colonia Agrícola de Turen, Venezuela

    NASA Astrophysics Data System (ADS)

    Perez, Maiby Yolanda; Florentino de Andreu, Adriana

    2013-04-01

    Soil physical degradation is a major problem affecting the soil quality for crops production in Venezuelan agricultural areas. The least limiting water range (LLWR) is considered a soil physical quality index defined as the range in soil water content within which the limitations to plant response associated with water potential, poor aeration and high mechanical resistance are minimal. The study was carried out to characterize the LLWR and to determine the LLWR response to structural changes on soils of the Colonia Agricola de Turen, Venezuela. The soils were cropped with maize under different tillage systems (no tillage, conventional and conventional - fallow) and non-cropped under native forest. Hundred and seventy undisturbed samples were taken from specific sites under each of the above soil conditions to determine the water retention curve, the soil resistance curve and bulk density. Disturbed samples were also taken from each site to determine particle size and organic matter content. Pedotransfer functions relating the water retention curve and soil resistance curve with particle size distribution, organic matter content and bulk density were developed and use to calculate the LLWR for each site. According to the results, soil physical degradation under conventional tillage and high clay content had the highest negative impact on the LLWR. For this case (silty clay loam soil), the LLWR became narrower due to the lower water content associated with poor aeration and the higher water content associated with high mechanical resistance. In contrast, for non degraded soils with high sand content (sandy loam) the LLWR showed the highest values associated with the water content at field capacity and the water content at permanent wilting point, both the upper and lower critical limits of LLWR. For silty loam and loam soils the LLWR declined with increasing bulk density and clay content associated with water content at field capacity and water content at high mechanical resistance. Soil resistance to root penetration determined the lower limit of LLWR in 41 % of the soils and the water content at field capacity determined the upper limit of LLWR in 94% of the soils. Further studies are recommended to determine the nature and magnitude of the association between the LLWR and crop yield under different soils and climate conditions.

  11. Some autecological characteristics of early to late successional tree species in Venezuela

    NASA Astrophysics Data System (ADS)

    Kammesheidt, Ludwig

    2000-01-01

    The breadth of the continuum concept of strategy with respect to succession was tested on 21 tree and shrub species common in either unlogged or logged stands, respectively, in the Forest Reserve of Caparo, Venezuela, by examining morphological, physiological and population characteristics. Based on a preliminary abundance analysis, `early', `mid' and `late' successional species as well as `generalists' were distinguished. Early successional species, i.e. Ochroma lagopus, Heliocarpus popayanensis and Cecropia peltata were similar in many autecological aspects, e.g. monolayered leaf arrangement, orthotropic architectural models, no adaptive reiteration, clumped distribution, but differed in gap association and distribution along a drainage gradient. Mid-successional species established themselves both in large and small gaps (> 300 m[sup2 ]; 80-300 m[sup2 ]) and showed a clumped to regular distribution pattern in logged areas; they exhibited more diverse crown and leaf characteristics than early successional species. Late successional species established themselves only in small gaps and understorey, and showed a regular spatial pattern in undisturbed areas. All late successional species displayed architectural models with plagiotropic lateral axes and showed a multilayered leaf arrangement. Adaptive reiteration was a common feature of late successional species which could be further subdivided into large, medium-sized and small trees, indicating different light requirements at maturity. Generalists were common treelet and shrub species in both disturbed and undisturbed sites where they are also capable of completing their life cycle. The light compensation point (LCP) of an individual plant was strongly influenced by its crown illuminance. Large late successional species showed the widest range of LCP values, reflecting the increasing light availability with increasing height in mature forest. On the basis of many autecological characteristics, it was found (i) that there is in fact a continuum of species strategies with respect to succession even among early and mid-successional species and (ii) that the latter group of species showed the widest breadth of autecological traits, reflecting the heterogeneous environment in which they establish and mature.

  12. Breeding biology of the golden-faced Tyrannulet (Zimmerius chrysops) in venezuela

    USGS Publications Warehouse

    Goulding, W.; Martin, T.E.

    2010-01-01

    We present the first detailed information on the breeding biology of the Golden-faced Tyrannulet (Zimmerius chrysops). Information was gathered from 96 nests in Yacamb National Park, Venezuela during the 2002 to 2008 breeding seasons. The enclosed nest was similar to descriptions of nests of other species in the genus. Eggs were laid on alternate days with mean (?? SE) clutch size of 1.98 ?? 0.02 (n 45) and fresh weight of 1.616 ?? 0.020 g (n 48). Only the female incubated and the incubation period averaged 16.9 ?? 0.3 days (n 10). Nest attentiveness ( time on the nest) averaged 66.0 ?? 1.6 (n 40) and increased from early to mid- and late-incubation. Incubation behavior yielded an average 24-hr egg temperature of 34.88 ?? 0.45?? C (n 7 nests, 43 days). The nestling growth rate constant for body mass (k 0.285 ?? 0.011) was slow even for tropical tyrannids. The nestling period for nests where exact hatch and fledging days were observed ranged from 17 to 19 days with an average of 18.0 ?? 0. 2 days (n 9). Both females and males fed nestlings at a rate that increased over the nestling period with a mean of 4.41 ?? 0.65 trips/hr (n 10) during days 1 and 2 after hatching, and 14.93 ?? 2.36 trips/hr (n 6) at pin-break (days 1011). Daily predation rates were similar in egg-laying (0.052 ?? 0.025; n 76.5 exposure days) and incubation periods (0.068 ?? 0.010; n 575.5 exposure days), but were lower during the nestling period (0.039 ?? 0.010; n 377.0 exposure days). The total daily predation rate (0.057 ?? 0.007; n 989.0 exposure days) indicated only 12 of nests were successful. These breeding biology parameters for Z. chrysops differ substantially from other tyrant-flycatchers and temperate species, further highlighting the diversity within the Tyrannidae. ?? 2010 by the Wilson Ornithological Society.

  13. Determinants of late disease-stage presentation at diagnosis of HIV infection in Venezuela: A case-case comparison

    PubMed Central

    Bonjour, Maeva A; Montagne, Morelba; Zambrano, Martha; Molina, Gloria; Lippuner, Catherine; Wadskier, Francis G; Castrillo, Milvida; Incani, Renzo N; Tami, Adriana

    2008-01-01

    Background Although Venezuela has a National Human Immunodeficiency Virus (HIV) Program offering free diagnosis and treatment, 41% of patients present for diagnosis at a later disease-stage, indicating that access to care may still be limited. Our study aimed to identify factors influencing delay in presenting for HIV-diagnosis using a case-case comparison. A cross-sectional survey was performed at the Regional HIV Reference Centre (CAI), Carabobo Region, Venezuela. Between May 2005 and October 2006 225 patients diagnosed with HIV at CAI were included and demographic, behavioural and medical characteristics collected from medical files. Socio-economic and behavioural factors were obtained from 129 eligible subjects through interviews. "Late presentation" at diagnosis was defined as patients classified with disease-stage B or C according to the 1993 Centers for Disease Control and Prevention (Atlanta, USA) classification, and "early presentation" defined as diagnosis in disease-stage A. Results Of 225 subjects, 91 (40%) were defined as late presenters. A similar proportion (51/129) was obtained in the interviewed sub-sample. Older age (>30 years), male heterosexuality, lower socio-economic status, perceiving ones partner to be faithful and living ? 25 km from the CAI were positively associated with late diagnosis in a multivariate model. Females were less likely to present late than heterosexual males (odds ratio = 0.23, P = 0.06). The main barriers to HIV testing were low knowledge of HIV/AIDS, lack of awareness of the free HIV program, lack of perceived risk of HIV-infection, fear for HIV-related stigma, fear for lack of confidentiality at testing site and logistic barriers. Conclusion Despite the free Venezuelan HIV Program, poverty and barriers related to lack of knowledge and awareness of both HIV and the Program itself were important determinants in late presentation at HIV diagnosis. This study also indicates that women; heterosexual, bisexual and homosexual men might have different pathways to testing and different factors related to late presentation in each subgroup. Efforts must be directed to i) increase awareness of HIV/AIDS and the Program and ii) the identification of specific factors associated with delay in HIV diagnosis per subgroup, to help develop targeted public health interventions improving early diagnosis and prognosis of people living with HIV/AIDS in Venezuela and elsewhere. PMID:18416849

  14. PREFACE: XII Latin American workshop on plasma physics (17-21 September 2007, Caracas, Venezuela)

    NASA Astrophysics Data System (ADS)

    Puerta, Julio

    2008-10-01

    Some years ago a group of Latin American physicists took the initiative to consult about the viability of organizing a meeting on plasma physics for researchers and students of the region. The result was that it was not only a good idea, but a necessity in order to show and share everyone's work, and to keep updated on latest advances and technologies on plasma physics. It was decided that for new researchers as well as students of Physics, it would prove to be the best way to keep them posted on such matters. This was the birth of a series of meetings known as Latin American workshops on plasma physics that take place every two years in a different Latin American country. In Venezuela we have had the opportunity to organize two editions of this interesting and important reunion of physicists. The first of these Latin American workshops on plasma physics was held in Cambuquira (Brazil) in 1982. After organizing the first six editions of the workshop, the VII LAWPP meeting was realized in Caracas in January 1997. It was designed with a structure similar to the first edition. It developed in two stages, a first week devoted to short courses with lecturers in different fields of plasma physics and a second week for contributed and invited presentations. Participants from sixteen different countries were present, half of them from this continent and the other half from overseas, demonstrating the international character of this meeting. There have been four more editions of the workshop and once again, we have had the opportunity to organize this latest edition of the series: the XII Latin American workshop on plasma physics, which took place in Caracas, Venezuela from the 17th to the 21st of September 2007. The structure was modified, because contributed and review papers were together during the first stage, with short courses realized during the second one, called mini-courses, and given by several high level contributors such as José Boedo, Leopoldo Soto, Claude Deutsch, Ricardo Galvao, Carlos Hidalgo, Paulo Sakanaka, Konosuke Sato, Malcom Haines and Maher Boulos. The general feeling is that these mini-courses were very successful. As an original idea of Professor Ricardo Magnus Osorio Galvão, Director of Centro Brasileiro de Pesquisas Físicas, we saluted the creation of The Vladimir Tsypin Award to the best Poster in the meeting. This prize was presented by Professor Galvão in memoriam of Vladimir Semenovich Tsypin. It was suggested that the granting of this award be made in every meeting from now on. We think that it is very important to emphasise the mini-courses due to the necessity of increasing in the near future a better formation for our young scientists. The contributions of all the lecturers are greatly appreciated. We had the typical fields in plasma physics as in past meetings. We also appreciated very much the lectures of Professor Malcolm Haines, Professor Sergey Popel, Professor Claude Deutsch, and Professor Antony Peratt for their very interesting talks on the Z-Pinch recorded to prehistory. Special thanks again to these lecturers since they have joined and honoured our meetings in the past as well. As in the VII LAWPP, all the sessions of the workshop were held at the Universidad Simon Bolivar campus, located in the nice green Valley of Sartenejas near Caracas. We also appreciate the stimulus and the financial support that we have always had for the preparation of these workshops from our institution by means of its authorities: Professor Benjamin Sharifker (Rector), Professor Aura Lopez (Dean of Academic Activities), (Professor Jose Luis Paz (Dean of Research and Development), Professor Pedro Berrisbeitia (Dean of Postgraduate Studies) and Professor William Colmenares (Dean of Extended Activities). We must also mention and appreciate the collaboration of architect Alejandro Chataing Roncajolo as Secretary and Coordinator of the Congress, as well as the daily important collaborations of our students Anais Möller, Laura Beiras, Juan Contreras, Gabriel Torrente, Aimée Guerrero, Francisco Jose Blanco

  15. Anatomy of biologically mediated opal speleothems in the World's largest sandstone cave: Cueva Charles Brewer, Chimantá Plateau, Venezuela

    NASA Astrophysics Data System (ADS)

    Aubrecht, R.; Brewer-Carías, Ch.; Šmída, B.; Audy, M.; Ková?ik, ?.

    2008-01-01

    Siliceous speleothems can be formed in sandstone caves. Recently, opal "biospeleothems" have been found in the World's largest cave in Precambrian sandstones on the Chimantá Tepui in Venezuela. The speleothems, although reminiscent of normal stalactites and stalagmites from limestone caves, are in fact large microbialites. More than a dozen forms were distinguished, but they share a common structure and origin. They consist of two main types: 1. fine-laminated columnar stromatolite formed by silicified filamentous microbes (either heterotrophic filamentous bacteria or cyanobacteria) and 2. a porous peloidal stromatolite formed by Nostoc-type cyanobacteria. The first type usually forms the central part and the second type, the outer part, of speleothems. Fungal hyphae, metazoan and plant remains also subordinately contribute to speleothem construction. The speleothems occur out of the reach of flowing water; the main source of silica is the condensed cave moisture which is the main dissolution-reprecipitation agent. Speleothems which originated by encrustation of spider threads are unique.

  16. Temporal variations of heavy metals levels in Perna viridis, on the Chacopata-Bocaripo lagoon axis, Sucre State, Venezuela.

    PubMed

    Pinto, Rafael; Acosta, Vanessa; Segnini, Mary Isabel; Brito, Leonor; Martínez, Gregorio

    2015-02-28

    Perna viridis was used as biomonitor to assess heavy metal levels in the Chacopata-Bocaripo lagoon axis, Venezuela, during rain and drought seasons. The mussels were weighed and measured. The metal concentrations were determined by atomic absorption spectrophotometry. For rain period, the order of bioavailability was: Cu>Ni>Mn>Co>Cd>Pb, and for drought: Cu>Mn>Ni>Co>Pb>Cd. The concentrations of Ni, Co, Cd and Pb showed significant differences (P<0.05) in both periods. There was higher metal accumulation during drought season, possibly related to upwelling, since it produces an increase in primary productivity, which translates more food into organisms, making metals bioavailable for mussels. Only Cu and Mn showed significant relationships between the size and metal concentration, during drought period, it may be because of the organisms need for these essential metals in different physiological processes. PMID:25444616

  17. The use of radar and LANDSAT data for mineral and petroleum exploration in the Los Andes region, Venezuela

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.

    1980-01-01

    A geological study of a 27,500 sq km area in the Los Andes region of northwestern Venezuela was performed which employed both X-band radar mosaics and computer processed Landsat images. The 3.12 cm wavelength radar data were collected with horizontal-horizontal polarization and 10 meter spatial resolution by an Aeroservices SAR system at an altitude of 12,000 meters. The radar images increased the number of observable suspected fractures by 27 percent over what could be mapped by LANDSAT alone, owing mostly to the cloud cover penetration capabilities of radar. The approximate eight fold greater spatial resolution of the radar images made possible the identification of shorter, narrower fractures than could be detected with LANDSAT data alone, resulting in the discovery of a low relief anticline that could not be observed in LANDSAT data. Exploration targets for petroleum, copper, and uranium were identified for further geophysical work.

  18. Debris-flow and flooding hazards associated with the December 1999 storm in coastal Venezuela and strategies for mitigation

    USGS Publications Warehouse

    Wieczorek, G.F.; Larsen, M.C.; Eaton, L.S.; Morgan, B.A.; Blair, J.L.

    2001-01-01

    Heavy rainfall from the storm of December 14-16, 1999 triggered thousands of landslides on steep slopes of the Sierra de Avila north of Caracas, Venezuela. In addition to landslides, heavy rainfall caused flooding and massive debris flows that damaged coastal communities in the State of Vargas along the Caribbean Sea. Examination of the rainfall pattern obtained from the GOES-8 satellite showed that the pattern of damage was generally consistent with the area of heaviest rainfall. Field observations of the severely affected drainage basins and historical records indicate that previous flooding and massive debris-flow events of similar magnitude to that of December 1999 have occurred throughout this region. The volume of debris-flow deposits and the large boulders that the flows transported qualifies the 1999 event amongst the largest historical rainfall-induced debris flows documented worldwide.

  19. Recurrent wheezing is associated with intestinal protozoan infections in Warao Amerindian children in Venezuela: a cross-sectional survey

    PubMed Central

    2014-01-01

    Background While in developed countries the prevalence of allergic diseases is rising, inflammatory diseases are relatively uncommon in rural developing areas. High prevalence rates of helminth and protozoan infections are commonly found in children living in rural settings and several studies suggest an inverse association between helminth infections and allergies. No studies investigating the relationship between parasitic infections and atopic diseases in rural children of developing countries under the age of 2 years have been published so far. We performed a cross-sectional survey to investigate the association of helminth and protozoan infections and malnutrition with recurrent wheezing and atopic eczema in Warao Amerindian children in Venezuela. Methods From August to November 2012, 229 children aged 0 to 2 years residing in the Orinoco Delta in Venezuela were enrolled. Data were collected through standardized questionnaires and physical examination, including inspection of the skin and anthropometric measurements. A stool sample was requested from all participants and detection of different parasites was performed using microscopy and real time polymerase chain reaction (PCR). Results We observed high prevalence rates of atopic eczema and recurrent wheezing, respectively 19% and 23%. The prevalence of helminth infections was 26% and the prevalence of protozoan infections was 59%. Atopic eczema and recurrent wheezing were more frequently observed in stunted compared with non-stunted children in multivariable analysis (OR 4.3, 95% CI 1.3 – 13.6, p?=?0.015 and OR 4.5, 95% CI 0.97 – 21.2, p?=?0.055). Furthermore, recurrent wheezing was significantly more often observed in children with protozoan infections than in children without protozoan infections (OR 6.7, 95% CI 1.5 – 30.5). Conclusions High prevalence rates of atopic eczema and recurrent wheezing in Warao Amerindian children under 2 years of age were related to stunting and intestinal protozoan infections respectively. Helminth infections were not significantly associated with either atopic eczema or recurrent wheezing. PMID:24885094

  20. Montelukast for the high impact of asthma exacerbations in Venezuela: a practical and valid approach for Latin America?

    PubMed Central

    2014-01-01

    Background Asthma affects mainly Venezuela’s urban and poor majority. Exacerbations bring about a high demand in health services, thus becoming a significant public health problem. In general, asthma control programs (GINA) with use of inhaled steroid medications have proven effective, although their implementation in real life remains cumbersome. Montelukast could be a useful and practical tool for these deprived socioeconomic sectors. Methods This real-life pilot study was conducted in a prospective, double blinded, placebo-controlled manner with randomized and parallel groups. Asthmatics that had never used leukotriene modifiers were recruited and followed-up every three months. The main outcome was the number of exacerbations meriting use of nebulized bronchodilators administered by the health care system. Results Eighty-eight asthmatic patients were enrolled, between children and adults. Groups were comparable in: demographic data, previous use of other medications, ACT scores, pulmonary functions (Wright Peak Flow meter), allergy status (Skin Prick Test) as well as adherence to the prescribed Montelukast treatment. By an intention to treat (ITT), a total of 64 patients were included for analysis. For the three and six months time points the difference between placebo and Montelukast was found to be significant (p < 0.03 and p < 0.04, respectively). Such trends continued for the rest of the year, but without statistical significance, due to patient attrition. Conclusions This real-life pilot study shows that a simplified strategy with oral Montelukast was practical and effective in controlling exacerbations in an asthmatic population of a vulnerable community from Caracas. Such an approach reinforces the role of primary care in asthma treatment. PMID:25232371

  1. Cenozoic uplift of the Northerm Margin of the Guayana Shield, Venezuela, and its influence on the distribution of mineral deposits

    SciTech Connect

    Olmore, S.D. ); Garcia, A. ); Antonia, S.C. )

    1993-02-01

    We present new ideas regarding the Cenozoic intraplate tectonics of the northern margin of the Guayana Shield. During Caribbean Orogeny tectonic transpression induced by right-lateral shear brought about the uplift of a 500 km by 200 km, east-northeast-trending elongate region south of the Orinoco River in south-central Venezuela-Uplifted Imataca Block (UIB). Erosional stripping of mineralized greenstone units from the UIB exposed a high-grade metamorphic core of quartz-feldspar granulite gneiss of Archean age. A 1000-meter-thick section of deltaic sediments from erosion of the UIB were deposited in the marginal basin to the north during Miocene and younger time. These sedimentary units host the Orinoco heavy-oil belt. The UIB is bounded on the north by a series of east-northeast-trending step faults that lie along the approximate trace of the Orinoco River. The UIB is bounded on the south by the Guri fault zone. Numerous sub-parallel faults within the exposed Archean block show evidence of late Cenozoic, post-uplift, right-lateral and normal displacement. Some conclusions: (1) high-grade Archean granulite or praqneiss may underlie portions of the Proterozoic greenstone and granite-gneiss terrain of the Guayana shield to the south; (2) differences in El Pao and Cerro Bolivar iron ores are explained by differential erosional stripping accompanying block uplift. (3) The juxtaposition of oil-bearing Cenozoic sediments and metal-rich Archean and lower Proterozoic greenstone units by Mesozoic and Cenozoic faulting makes central Venezuela one of the richest mineral-bearing provinces of the world.

  2. Semi-Periodic Sequences and Extraneous Events in Earthquake Forecasting. II: Application, Forecasts for Japan and Venezuela

    NASA Astrophysics Data System (ADS)

    Quinteros Cartaya, Claudia Beatriz; Nava Pichardo, Fidencio Alejandro; Glowacka, Ewa; Frez Cárdenas, José Duglas

    2014-07-01

    In order to analyze observed seismicity in central Japan and Venezuela, we applied a new method to identify semi-periodic sequences in the occurrence times of large earthquakes, which allows for the presence of multiple periodic sequences and/or events not belonging to any sequence in the time series. We also explored a scheme for diminishing the effects of a sharp cutoff magnitude threshold in selecting the events to analyze. A main four-event sequence with probability P c = 0.991 of not having occurred by chance was identified for earthquakes with M ? 8.0 in central Japan. Venezuela is divided, from West to East, into four regions; for each of these, the magnitude ranges and identified sequences are as follows. Region 1: M ? 6.0, a six-event sequence with P c = 0.923, and a four-event sequence with P c = 0.706. Region 2: M ? 5.6, a five-event sequence with P c = 0.942. Region 3: M ? 5.6, a four-event sequence with P c = 0.882. Region 4: M ? 6.0, a five-event sequence with P c = 0.891. Forecasts are made and evaluated for all identified sequences having four or more events and probabilities ?0.5. The last event of all these sequences was satisfactorily aftcast by previous events. Whether the identified sequences do, in fact, correspond to physical processes resulting in semi-periodic seismicity is, of course, an open question; but the forecasts, properly used, may be useful as a factor in seismic hazard estimation.

  3. Trypanosoma cruzi III from armadillos (Dasypus novemcinctus novemcinctus) from Northeastern Venezuela and its biological behavior in murine model. Risk of emergency of Chagas' disease.

    PubMed

    Morocoima, Antonio; Carrasco, Hernán J; Boadas, Johanna; Chique, José David; Herrera, Leidi; Urdaneta-Morales, Servio

    2012-11-01

    Trypanosoma cruzi, etiological agent of Chagas' disease, was isolated from armadillos (Dasypus novemcinctus novemcinctus) captured in rural communities Northeastern Venezuela from Nueva Esparta State (no endemic for Chagas' disease), Monagas and Anzoátegui States (endemics). The isolates, genetically typed by PCR-RFLP as belonging to the TcIII DTU, have demonstrated in murine model heterogenic parasitemia, mortality and histotropism with marked parasitism in cardiac, skeletal, and smooth myocytes that showed correlation with lymphobasophilic inflammatory infiltrates. Our finding of T. cruzi infected armadillos in Isla Margarita (Nueva Esparta State), together with reports of triatomine vectors in this region, the accentuated synanthropy of armadillos, intense economic activity, migration due to tourism and the lack of environmental education programs all of them represent risks that could cause the emergence of Chagas' disease in this area. This is the first report of the TcIII DTU in Northeastern Venezuela, thus widening the geographic distribution of this DTU. PMID:22902748

  4. Morphometric evidence for a possible role of Rhodnius prolixus from palm trees in house re-infestation in the State of Barinas (Venezuela).

    PubMed

    Feliciangeli, M Dora; Sanchez-Martin, Maria; Marrero, Rosalba; Davies, Clive; Dujardin, Jean-Pierre

    2007-02-01

    The main vector of Chagas disease in Venezuela is Rhodnius prolixus. Specimens of Rhodnius sp., identified elsewhere as R. prolixus by molecular tools, were collected in Barinas State (Venezuela) before insecticide application, and compared by morphometric techniques with post-spraying, re-infesting insects after control. Geometric morphometry was applied, allowing separate analyses of shape and size. The idea of a single species sharing silvatic and domestic/peri-domestic ecotopes was supported, suggesting new evolutionary scenarios for the controversial R. prolixus origins. The same data allowed to understand the possible mechanisms of villages re-infestation after a control campaign, either recolonization by local recovery of survivors or re-infestation by external migrants. Both mechanisms were apparent. Although shape properties could distinguish very close subpopulations such as insects from houses and insects from peri-domestic shelters, they were unable to identify the insects from palm trees as a distinct subpopulation. This strongly suggested that human environment could receive immigrants from palm trees. The pattern of size variation supported the hypothesis of a one-way exchange from silvatic to human environments, but did not support the reverse movement. Thus, morphometric data indicated that a silvatic population of the local vector is probably responsible for re-infesting villages after insecticide application, and they also pointed to the existence of re-infestation by local recovery of survivors. According to this interpretation, new epidemiological scenarios must be considered to improve Chagas disease control in Venezuela. PMID:17306204

  5. Mycobacterium tuberculosis ecology in Venezuela: epidemiologic correlates of common spoligotypes and a large clonal cluster defined by MIRU-VNTR-24

    PubMed Central

    2009-01-01

    Background Tuberculosis remains an endemic public health problem, but the ecology of the TB strains prevalent, and their transmission, can vary by country and by region. We sought to investigate the prevalence of Mycobacterium tuberculosis strains in different regions of Venezuela. A previous study identified the most prevalent strains in Venezuela but did not show geographical distribution nor identify clonal genotypes. To better understand local strain ecology, we used spoligotyping to analyze 1298 M. tuberculosis strains isolated in Venezuela from 1997 to 2006, predominantly from two large urban centers and two geographically distinct indigenous areas, and then studied a subgroup with MIRU-VNTR 24 loci. Results The distribution of spoligotype families is similar to that previously reported for Venezuela and other South American countries: LAM 53%, T 10%, Haarlem 5%, S 1.9%, X 1.2%, Beijing 0.4%, and EAI 0.2%. The six most common shared types (SIT's 17, 93, 605, 42, 53, 20) accounted for 49% of the isolates and were the most common in almost all regions, but only a minority were clustered by MIRU-VNTR 24. One exception was the third most frequent overall, SIT 605, which is the most common spoligotype in the state of Carabobo but infrequent in other regions. MIRU-VNTR homogeneity suggests it is a clonal group of strains and was named the "Carabobo" genotype. Epidemiologic comparisons showed that patients with SIT 17 were younger and more likely to have had specimens positive for Acid Fast Bacilli on microscopy, and patients with SIT 53 were older and more commonly smear negative. Female TB patients tended to be younger than male patients. Patients from the high incidence, indigenous population in Delta Amacuro state were younger and had a nearly equal male:female distribution. Conclusion Six SIT's cause nearly half of the cases of tuberculosis in Venezuela and dominate in nearly all regions. Strains with SIT 17, the most common pattern overall may be more actively transmitted and SIT 53 strains may be less virulent and associated with reactivation of past infections in older patients. In contrast to other common spoligotypes, strains with SIT 605 form a clonal group centered in the state of Carabobo. PMID:19660112

  6. Oncoplastic breast surgery: initial experience at the Centro Clinico de Estereotaxia—CECLINES, Caracas, Venezuela

    PubMed Central

    Acosta-Marin, V; Acosta-Freites, V; Contreras, A; Ravelo, R; Fuenmayor, G; Marin, C; Ramirez, A; Acosta-Marin, M; Perez-Fuentes, J; Longobardi, I; Esteves, H

    2014-01-01

    Background Breast-conserving surgery (BCS) may sometimes lead to deformities in the remaining breast. Oncoplastic surgery (OPS) aims to improve our aesthetic results even in the case of major volume resections. The purpose of this study is to provide an objective evaluation of our initial experience with OPS, mainly based on the levels of satisfaction reported by both patients and surgeons. Patients and Methods This prospective study was performed at CECLINES in Caracas, Venezuela, between January 2011 and October 2012. It involved 107 consecutive patients in two groups: 52 patients with level II OPS versus 55 patients with ‘standard’ BCS (SBCS). We evaluated the level of satisfaction and cosmetic outcome at 6 and 12 months post-operation using a score from 1 (bad) to 5 (excellent). The cosmetic score was recorded during the follow-up by the surgeon, by phone calls, and photographs were reviewed by a panel of four observers. Results The participation rate in the cosmetic outcome/level of satisfaction evaluation was 100% at 6 months and 96.2% at 12 months. The average tumour size was 23 mm [standard deviation (SD): 13.5] for the OPS group versus 17.6 mm (SD: 8.3) for the SBCS group (p = 0.017). The average weight for the surgical specimen was 101 g (range: 30–512 g) in the OPS group versus 60.4 g (range: 20–135 g) in the SBCS group (p = 0.004). The OPS techniques most performed were round block 40.3% (21/52), inverted T mammoplasty 26.8% (14/52) and vertical scar mammoplasty 15.3% (8/52). Of all the patients, 51.9% (27/52) had symmetrisation procedures performed distributed according to the period of the study: 77.2% (17/22) in 2011, 56.6% (17/30) in 2012, and 18.1% (6/33) in 2013. The rate of complications was 5.7% (3/52) in the OPS group and 0% for the SBCS group (p < 0.005). The average cosmetic score at 6 months by patients in the OPS group was 4.4; patient satisfaction scores of 4 (good) and 5 (excellent) were 88.4%. In the SBCS group at 6 months, the mean score reported by patients was 4.2, with scores 4–5 being 83.4% (p = 0.644). The cosmetic score by surgeons in the OPS group at 6 months was 4.5; the surgeon satisfaction scores of 4–5 were 94.2%. In the SBCS group, the surgeons’ mean score at 6 months was 4.1, with 84.5% of scores being 4 or 5 (p < 0.005). The final cosmetic score by patients in the OPS group at 12 months was 4.5; patient satisfaction scores of 4–5 were 90.4%. In the SBCS group, the final mean score at 12 months by patients was 4.2, with 77.5% of scores being 4 or 5 (p < 0.005). The final cosmetic score by surgeons in the OPS group at 12 months was 4.5; surgeon satisfaction scores of 4–5 were 92.3%. In the SBCS group, the surgeons’ final mean score at 12 months was 4.1, with 84.5% of scores being 4 or 5 (p < 0.005). Conclusions OPS provides good satisfaction rates. An SBCS when an OPS is not indicated mostly results in good satisfaction levels and cosmetic scores. Usually, the results remain stable after 6 months. The use of OPS allows the excision of bigger lesions and surgical specimens. Symmetrisation procedures are not always required. With the appropriate patient selection, the rate of complications is low for both OPS and SBCS. PMID:25374618

  7. Mapping lithosphere thickness beneath the Southern Caribbean and Venezuela using body wave reflectivity and surface wave tomography

    NASA Astrophysics Data System (ADS)

    Masy, J.; Niu, F.; Levander, A.; Schmitz, M.

    2012-12-01

    The Caribbean (CAR) and South American (SA) plate boundary in Venezuela is a broad zone of diffuse deformation and faulting. GPS measurements indicate that the CAR is moving approximately 2 cm/yr respect to SA, parallel to the strike slip fault system in the east, but with an oblique convergence component in the west (Weber et al., 2001). Along the central and eastern Venezuela coast, most of the motion is accommodated by both transpression and transtension along the right lateral strike-slip San Sebastian- El Pilar fault system. The main tectonic features of the area include accretionary wedges and coastal thrust belts with their associated foreland basins (e.g. Sierra del Interior and Espino Graben). Southern of the plate boundary is located the Guayana Shield, which is part of the Amazonian Craton, and is an elevated plain consisting of Precambrian rocks. BOLIVAR (Broadband Onshore-Offshore Lithospheric Investigation of Venezuela and the Antilles Arc Region) was a multidisciplinary, international investigation to determine the evolution of the CAR-SA plate boundary (Levander et al., 2006) that included a 47 station broadband seismic array to complement the 40 station Venezuelan national array operated by FUNVISIS. The goal of this study is to map out lithosphere thickness across the region in order to understand its role for the various types of deformations observed at surface. We combined surface wave tomography and body wave reflectivity to locate the depth of the lithosphere-asthenosphere boundary (LAB). To generate a coherent 3D reflectivity volume of the study area, we used both P- and S-wave receiver-function data, as well as the ScS reverberation records of two deep earthquakes occurring in South America. We also measured Rayleigh phase velocities in the frequency range of 20-100 s using the two plane-wave method to remove multi-pathing effects (Forsyth and Li, 2005). Finite-frequency kernels were computed for a total of 63 teleseismic events to improve lateral resolution (Yang and Forsyth, 2006). The phase velocities were inverted for 1D shear velocity structure on a 0.5 by 0.5 degree grid. Crustal thickness for the starting models was previously determined from BOLIVAR and other wide-angle seismic experiments and receiver function analysis (Schmitz et al., 2001; Niu et al., 2007; Bezada et al., 2007; Clark et al., 2008; Guedez, 2008; Magnani et al., 2009; Bezada et al., 2010a). The resulting 3D shear velocity model was then used to determine the depth of the LAB in conjunction with Ps and Sp receiver functions. LAB depth is approximately 120-140 km beneath the Archean-Proterozoic Guayana Shield, in reasonable agreement with body wave tomography. The lithosphere thins to the west beneath the Barinas Apure Basin to about 90 km, and to the north beneath the Sierra del Interior to 80 to 90 km. Offshore beneath the Cariaco basin the LAB is ~60 km. At depths up to 200 km beneath the Peninsula the Paria, there are high velocities interepreted as the subducting oceanic part of the South American Plate, a result that is consistent with finite-frequency P wave tomography (Bezada et al., 2010b).

  8. Health Seeking Behaviour and Treatment Intentions of Dengue and Fever: A Household Survey of Children and Adults in Venezuela

    PubMed Central

    Elsinga, Jelte; Lizarazo, Erley F.; Vincenti, Maria F.; Schmidt, Masja; Velasco-Salas, Zoraida I.; Arias, Luzlexis; Bailey, Ajay; Tami, Adriana

    2015-01-01

    Background Dengue in Venezuela is a major public health problem with an increasing incidence of severe cases. Early diagnosis and timely treatment influences the outcome of dengue illness, as delay in care-seeking is significantly associated with complications leading to severe dengue. We aimed to understand patterns of health seeking behaviour (HSB) in individuals exposed to high dengue incidence in order to improve early attendance to health centres. Methods Between September 2013 and February 2014 a cross-sectional household survey was performed in Maracay, Venezuela. Intended HSB of adults and children’s parents/guardians was assessed with respect to fever or suspected dengue. Data was collected through structured questionnaires from 105 individuals. Results Most individuals felt at risk of dengue and believed it could be a deadly disease. In the case of suspected dengue, the majority (60%) would choose to first seek medical help versus first treating at home, in contrast to 11% in the case of fever. Amongst those who decided to visit a doctor, a suspected dengue infection would prompt them to search medical help earlier than if having only fever (p<0.001). Multivariate analysis modelling showed that the independent factors associated with the intention to firstly visit a doctor versus treating at home in the case of dengue were feeling at risk (OR = 3.29; p = 0.042) and being an adult (as opposed to caring for a child as a parent/guardian; OR = 3.33, p = 0.021), while having had a previous dengue infection (OR = 0.29; p = 0.031) and living in the neighbourhood Caña de Azúcar (OR = 0.28, p = 0.038) were negatively associated with seeking medical care as their first action. Conclusion Knowledge of HSB related to dengue is scarce in the Americas, our study attempts to contribute to a better understanding of HSB in this region. Improving early dengue disease recognition and awareness may enhance prompt attendance to medical care in affected populations and thereby reduce mortality and severity of dengue. Especially for those with a previous dengue infection, efforts have to be made to promote prompt health centre attendance. PMID:26624283

  9. Mesozoic-Early Paleogene Paleogeography of Venezuela/Trinidad and its implications for Caribbean/South America plate interaction

    SciTech Connect

    James, K.H.; Rigby, S.M.

    1993-02-01

    We present paleogeographic reconstruction illustrating Jurassic-Early Cretaceous passive margin development along northern South America, followed by Late Cretaceous-Middle Eocene convergence between the Caribbean and South America plates. The maps support the model of in-situ origin of the Caribbean Plate. To construct the map's information from northern allochthonous units was combined with that from autochthonous units in the south. Allochthons comprise olistostromes, within upper Cretaceous-lower Paleogene flysch deposits, and upper Jurassic-lower Cretaceous metasediments in the Caribbean Mountains. In addition, northward tectonic escape of the Maracaibo Block and shortening resulting from plate collision were restored. The Late Cretaceous-Middle Eocene climax of Caribbean-South America plate collision was coeval from western Venezuela to Trinidad. Shortening juxtaposed rocks of disparate origins. However, the association of oceanic/volcanic elements with shelf deposits shows that the former were related to opening of the Caribbean and development of the Mesozoic passive margin of northern South America rather than originating in the Pacific. Since the late Eocene, plate interaction has been eastward migrating, dextral relative movement.

  10. Magnitude of fluid movement and rates of cementation associated with reverse faults Examples from the Maracaibo basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Perez, R. J.; Boles, J. R.

    2002-12-01

    Magnitude of vertical fluid movement and rates of quartz cementation were studied in three cored intervals where reverse faults cut the Eocene Misoa Fm in the Maracaibo basin, Venezuela. The faults are flower type structures, with slips up to 500 meters, generated by an Eocene inversion of Cretaceous-Paleocene normal displacements. The fault zones extend 2.5 meters away from the slip surface and are characterized by extensive quartz and chert precipitation associated with microfractures and cataclasis. Kinetic modeling of quartz precipitation suggests that the rates of microfracture annealing may have been initially up to 0.25 moles/C, lasting approximately 1 my after faulting started (37.5 mya) and subsequently decreasing during uplifting to less than 0.05 moles/C. Kinetic modeling suggests that quartz cementation along these reverse faults may have occurred in short periods of time and at approximately the same or lower rates than intervals away from faults. Minimum vertical distance of fluid flow along one fault zone was calculated with two different approaches. The first method divides the thermal gradient present during faulting (obtained through a thermal reconstruction of the area) by a difference between the host rock maximum burial temperature and fault cements temperatures (obtained from fluid inclusions). The second method integrates an average-weight function of the thermal gradient along the unknown depth. Both methods suggest that hot fluids, present during cementation, ascended a minimum of 450 to 800 meter along the fault zone.

  11. A new Dasypodini armadillo (Xenarthra: Cingulata) from San Gregorio Formation, Pliocene of Venezuela: affinities and biogeographic interpretations.

    PubMed

    Castro, Mariela C; Carlini, Alfredo A; Sánchez, Rodolfo; Sánchez-Villagra, Marcelo R

    2014-02-01

    We describe Pliodasypus vergelianus gen. et sp. nov., a Dasypodini armadillo from the middle Pliocene of Venezuela (Vergel Member, San Gregorio Formation). Although scarce, the remains are remarkable because of their geochronologic proximity to the main phase of Great American Biotic Interchange (GABI). The cladistic analysis conducted reveals that Pliodasypus groups with Dasypus and both are sister taxa of Propraopus, whereas Anadasypus is at a basal position. With respect to the records of tribe Dasypodini, after its oldest representative (Anadasypus, middle and late Miocene), the chronologically subsequent form is Pl. vergelianus (middle Pliocene), followed by Dasypus bellus in higher northern latitudes (late Pliocene), and then by widespread occurrences in the Pleistocene of North America (D. bellus) and South America (Propraopus, Dasypus punctatus, and Dasypus novemcinctus). Thus, we infer that Dasypus differentiated in the late Pliocene at low latitudes in the northern South America. It leads to two alternative hypotheses of dispersal: (a) some early Dasypus remained cryptically in South America until the Pleistocene, whereas others dispersed to North America between 2.2 and 2.7 Ma, or (b) they dispersed to North America subsequently to the emersion of the Panamanian isthmus and D. bellus differentiated there; later, during the Pleistocene, D. bellus entered South America and experienced speciation. The same process of re-ingression has been proposed to other xenarthrans, breaking with the traditional assumption that the GABI was unidirectional. PMID:24414134

  12. Sawfishes and Other Elasmobranch Assemblages from the Mio-Pliocene of the South Caribbean (Urumaco Sequence, Northwestern Venezuela)

    PubMed Central

    2015-01-01

    The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats. PMID:26488163

  13. Density estimates of the domestic vector of Chagas disease, Rhodnius prolixus Stål (Hemiptera: Reduviidae), in rural houses in Venezuela.

    PubMed Central

    Rabinovich, J. E.; Gürtler, R. E.; Leal, J. A.; Feliciangeli, D.

    1995-01-01

    We reported the use of the timed manual method, routinely employed as an indicator to the relative abundance of domestic triatomine bugs, to estimate their absolute density in houses. A team of six people collected Rhodnius prolixus Stål bugs from the walls and roofs of 14 typical palm-leaf rural houses located in Cojedes, Venezuela, spending 40 minutes searching in each house. One day after these manual collections, all the houses were demolished and the number of triatomine bugs were identified by instar and counted. Linear regression analyses of the number of R. prolixus collected over 4 man-hours and the census counts obtained by house demolition indicated that the fit of the data by instar (stage II--adult) and place of capture (roof versus palm walls versus mud walls) was satisfactory. The slopes of the regressions were interpreted as a measure of "catchability" (probability of capture). Catchability increased with developmental stage (ranging from 11.2% in stage II to 38.7% in adults), probably reflecting the increasing size and visibility of bugs as they evolved. The catchability on palm wall was higher than that for roofs or mud walls, increasing form 1.3% and 3.0% in stage II to 13.4% and 14.0% in adults, respectively. We reported, also, regression equations for converting field estimates of timed manual collections of R. prolixus into absolute density estimates. Images Fig. 1 PMID:7614667

  14. [Nitrogen, phosphorus and the C/N ratio in superficial sediments of the lagoon of Chacopata, Sucre, Venezuela].

    PubMed

    Fuentes Hernández, M V

    2000-12-01

    The basal behaviour and relationship with organic carbon (Corg) content and prevailing granulometric fractions, of organic nitrogen (Norg), total phosphorus (P-total) and C/N ratio in surface sediments of Chacopata lagoon, Sucre State, Venezuela, were studied. Concentrations and spatial gradients were determined in sixteen stations following a common method for marine sediments. Norg concentrations varied between 0.102 and 0.510% (x = 0.237%), total phosphorus between 0.012 and 0.094% (x = 0.058%) and C/N ratio between 9.27 and 44.47 (x = 20.53). The higher contents of Norg and total phosphorus are from sections with an abundance of mangroves, marine phanerogams, macroalgae, benthonic biomass and migratory birds shelters. The C/N ratio shows the typical values for carbonated sediments, indicating that the nitrogenous compounds are rapidly degraded and the organic matter presents itself as humic substances. This parameter was moderately associated with silt and clay, and showed antagonism with sand, whereas Norg and phosphorus showed no correlation with them. The organic contribution is purely autochthonous: no anthropogenous contributions were found. PMID:15266816

  15. Venezuela-MEM/USA-DOE Fossil Energy Report XIII-1, Supporting Technology for Enhanced Oil Recovery, Microbial EOR

    SciTech Connect

    Ziritt, Jose Luis

    1999-11-03

    The results from Annex XIII of the Cooperative Agreement between the United States Department of Energy (DOE) and the Ministry of Energy and Mines of the Republic of Venezuela (MEMV) have been documented and published with many researchers involved. Integrate comprehensive research programs in the area of Microbial Enhanced Oil Recovery (MEOR) ranged from feasibility laboratory studies to full-scale multi-well field pilots. The objective, to cooperate in a technical exchange of ideas and information was fully met throughout the life of the Annex. Information has been exchanged between the two countries through published reports and technical meetings between experts in both country's research communities. The meetings occurred every two years in locations coincident with the International MEOR conferences & workshops sponsored by DOE (June 1990, University of Oklahoma, September 1992, Brookhaven, September 1995, National Institute of Petroleum and Energy Research). Reports and publications produced during these years are listed in Appendix B. Several Annex managers have guided the exchange through the years. They included Luis Vierma, Jose Luis Zirritt, representing MEMV and E. B. Nuckols, Edith Allison, and Rhonda Lindsey, representing the U.S. DOE. Funding for this area of research remained steady for a few years but decreased in recent years. Because both countries have reduced research programs in this area, future exchanges on this topic will occur through ANNEX XV. Informal networks established between researchers through the years should continue to function between individuals in the two countries.

  16. Approaches to identifying reservoir heterogeneity and reserve growth opportunities from subsurface data: The Oficina Formation, Budare field, Venezuela

    SciTech Connect

    Hamilton, D.S.; Raeuchle, S.K.; Holtz, M.H.

    1997-08-01

    We applied an integrated geologic, geophysical, and engineering approach devised to identify heterogeneities in the subsurface that might lead to reserve growth opportunities in our analysis of the Oficina Formation at Budare field, Venezuela. The approach involves 4 key steps: (1) Determine geologic reservoir architecture; (2) Investigate trends in reservoir fluid flow; (3) Integrate fluid flow trends with reservoir architecture; and (4) Estimate original oil-in-place, residual oil saturation, and remaining mobile oil, to identify opportunities for reserve growth. There are three main oil-producing reservoirs in the Oficina Formation that were deposited in a bed-load fluvial system, an incised valley-fill, and a barrier-strandplain system. Reservoir continuity is complex because, in addition to lateral facies variability, the major Oficina depositional systems were internally subdivided by high-frequency stratigraphic surfaces. These surfaces define times of intermittent lacustrine and marine flooding events that punctuated the fluvial and marginal marine sedimentation, respectively. Syn and post depositional faulting further disrupted reservoir continuity. Trends in fluid flow established from initial fluid levels, response to recompletion workovers, and pressure depletion data demonstrated barriers to lateral and vertical fluid flow caused by a combination of reservoir facies pinchout, flooding shale markers, and the faults. Considerable reserve growth potential exists at Budare field because the reservoir units are highly compartment by the depositional heterogeneity and structural complexity. Numerous reserve growth opportunities were identified in attics updip of existing production, in untapped or incompletely drained compartments, and in field extensions.

  17. Solution weathering rate and origin of karst landforms and caves in the quartzite of Auyan-tepui (Gran Sabana, Venezuela)

    NASA Astrophysics Data System (ADS)

    Piccini, Leonardo; Mecchia, Marco

    2009-05-01

    The paper reports the results of SiO 2 analyses in the Aonda Cave system, located on the Auyán-tepui, one of the widest table-mountains of the Gran Sabana (South Venezuela), characterised by karst landforms developed in siliceous rock. Chemical analyses underline the very low concentration of SiO 2 of the surface water. Percolation and cave drip waters have a SiO 2 concentration of about 1 mg/l. The mean silica load of the cave stream is 184 mg/s, mainly derived from surface solution removal in the allogenic recharge area. In the Aonda Cave system, the mean SiO 2 dissolved load is 40 mg/s, in part from surface solution (15%) and mainly from underground processes (85%). The low solubility of SiO 2 in slightly acidic water implies the importance of the time factor in the formation of cave systems. With the present dissolution rate, about 10 Ma would be necessary to form the known karst system. This estimation can be significant only if we assume that climate has been stable in the last few tens of millions of years. Furthermore, this age can be taken as a minimum estimate, while, according to the geomorphic evolution of the area, the origin of the Aonda Cave system could be reasonably dated back to at least 20-30 Ma, that is, to the Oligocene.

  18. Aerosol particle properties in the tropical free troposphere observed at Pico Espejo (4765 m a.s.l.), Venezuela

    NASA Astrophysics Data System (ADS)

    Schmeißner, T.; Krejci, R.; Ström, J.; Birmili, W.; Wiedensohler, A.; Hochschild, G.; Gross, J.; Hoffmann, P.; Calderon, S.

    2010-11-01

    The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere were performed from March 2007 until Mai 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l. nearby the city of Mérida, Venezuela. Aerosol size distribution and number concentration data was obtained with a custom-built Differential Mobility Particle Sizer (DMPS system) and a Condensational Particle Counter (CPC). The analysis of the annual and diurnal variability of the tropical free troposphere (FT) aerosol focused mainly on possible links to the atmospheric general circulation in the tropics. Considerable annual and diurnal cycles of the particle number concentration were observed. Highest total particle number concentrations were measured during the dry season (519±613 cm-3), lowest during the wet season (318±194 cm-3). The more humid FT contained generally higher aerosol particle number concentrations (573±768 cm-3 during dry season, 320±195 cm-3 during wet season) than the dry FT (454±332 cm-3 during dry season, 275±172 cm-3 during wet season), indicating the importance of convection for aerosol distributions in the tropical FT. The diurnal cycle in the variability of the particle number concentration was mainly driven by local orography.

  19. [Risk factors associated with the diagnosis of chronic Chagasic miocardiopathy in seropositive individuals from Barinas state, Venezuela].

    PubMed

    González, Beatriz; Silva, Martha; Al-Atrache, Yusra; Delgado, Yelitze; Serrano, José Luis; Doccimo, Angelina; Hernández, Huber; Verde, Juan; Morillo, Daniela; Marín, Jaime; Concepción, Juan Luis; Bonfante-Cabarcas, Rafael; Rodríguez-Bonfante, Claudina

    2014-06-01

    This study evaluates the risk factors associated with the diagnosis of chronic chagasic miocardiopathy (CChM) in 115 seropositive individuals to anti-Trypanosoma cruzi antibodies, in Barinas state, Venezuela. Serology was performed with ELISA and MABA; while the CChM diagnosis was established by electrocardiography and echocardiography. A complete clinical history including epidemiological, personal/familiar antecedents and psychobiological habits, plus socioeconomic, psychosocial and alimentary habits interviews were performed for each individual. Risk factors were determined through binary logistic regression. Results showed that 81 patients (70,4%; CI 95% = 66.4-74.4) had criteria for CChM, of which 74 (64.4%; IC 95% = 60.2-68.6) were in phase II; while 34 (29.6%; IC 95% = 25.5-33.5) were in phase I of the disease and 7 (6.1%; IC 95% = 4.0-8.2) in phase III. In a one year period, two patients in phase III died of heart failure. The diagnosis of CChM was associated with hunting practice, maternal history of cardiopathies, chewing chimó, medical history of hypertension and apex beat visible; it was negatively associated with canned and preserved foods ingest. In conclusion the CChM diagnosis has high frequency in seropositive individuals in Barinas and heart failure prevention must be based on an early medical attention and educative strategies in order to control risk factors. PMID:24974628

  20. Planktonic foraminiferal shell weight as a proxy for changing carbonate ion concentration in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Marshall, B. J.; McConnell, M. C.; Thunell, R.

    2010-12-01

    Ocean acidification, due to increased atmospheric CO2, has diverse implications for marine calcifiers. In this study we use biweekly sediment trap samples and concurrent hydrographic measurements collected between January 2003 and May 2007 in the Cariaco Basin, Venezuela (10°30’ N, 65°31 W) to assess the relationship between shell weight and carbonate ion concentration [CO32-] of two planktonic foraminiferal species, Globigerinoides ruber and Orbulina universa.. Measured salinity, pH, sea surface temperature (SST) and total alkalinity (TA) were used to estimate pCO2 and [CO32-]. Shells of both G. ruber (300-355 µm) and O. universa (425 - 700 µm) species were picked (10-20 per sample) and weighed. Globigerinoides ruber shell weights varied from 7 µg to 19 µg from 2003 to 2007, with an average value of 11 ± 0.86 µg while surface water [CO32-] ranged from ~225-290 µmol/kg and averaged 250 µmol/kg. The data reveal a strong positive linear relationship between foraminiferal shell weight and [CO32-] for G. ruber and we expect to observe a similar relationship for O. universa. The initial results suggest the use of foraminiferal shell weight as a proxy for past changes in ocean pH.

  1. Preliminary results from U-Th dating of glacial-interglacial deposition cycles in a silica speleothem from Venezuela

    NASA Astrophysics Data System (ADS)

    Lundberg, J.; Brewer-Carias, C.; McFarlane, D. A.

    2010-07-01

    Recent explorations in Cueva Charles Brewer, a large cave in a sandstone tepui, SE Venezuela, have revealed silica biospeleothems of unprecedented size and diversity. Study of one — a sub-spherical mass of opaline silica — reveals a complex, laminated internal structure consisting of three narrow dark bands alternating with two wider light bands. Uranium-thorium dating has produced 3 stratigraphically correct dates on the light bands from 298 ± 6 (MIS 9) to 390 ± 33 ka (MIS 11). U concentration is only 30-110 ppb. Initial 234U/ 238U ratios are high and increase over time from 1.8 to 5.3. Growth rate is very low, the fastest, at 0.37 ± 0.23 mm/ka, in MIS 9. Trace element and heavy metal content of the dark bands is distinctly higher than that of the light bands. It is hypothesized that the dark and light bands correlate with drier/glacial and wetter/interglacial periods, respectively, and that this sample probably began to grow in MIS 13. The cave is in a region that straddles a regionally important ecotone: the speleothem isotopic and trace element variations may preserve a useful paleoclimatic signal. This is the first published suite of U-Th dates from a single silica speleothem and the longest Quaternary record for this region.

  2. Arbuscular mycorrhizal fungi communities in a coral cay system (Morrocoy, Venezuela) and their relationships with environmental variables.

    PubMed

    Alguacil, M M; Torrecillas, E; Lozano, Z; Roldán, A

    2015-02-01

    Knowledge of the natural diversity of arbuscular mycorrhizal fungi (AMF) and understanding of their biogeographical patterns and what drive them might help to the maintenance and preservation of ecosystems under a changing environment. The objective of this study was to evaluate the contribution of different environmental factors to the determination of the composition of AMF assemblages in representative sites within the Morrocoy National Park (Venezuela). The community structure of the AMF under the canopy of Coccoloba uvifera was investigated in four cays (Borracho, Muerto, Peraza, and Paiclás) and one mainland location (Las Luisas). Based on partial sequences of the nuclear small subunit ribosomal DNA gene, the AM fungi in soil samples were divided into 31 operational taxonomic units, grouped in eight families. The canonical correspondence analysis showed that environmental factors related to insularity (the mean annual rainfall, the distance to the mainland coast, and the cay land area) and a soil property related to biological activity (the total carbohydrate content) were significantly related to the distribution of the AMF communities. PMID:25461083

  3. Evaluation of the Seismic Hazard in Venezuela with a revised seismic catalog that seeks for harmonization along the country borders

    NASA Astrophysics Data System (ADS)

    Rendon, H.; Alvarado, L.; Paolini, M.; Olbrich, F.; González, J.; Ascanio, W.

    2013-05-01

    Probabilistic Seismic Hazard Assessment is a complex endeavor that relies on the quality of the information that comes from different sources: the seismic catalog, active faults parameters, strain rates, etc. Having this in mind, during the last several months, the FUNVISIS seismic hazard group has been working on a review and update of the local data base that form the basis for a reliable PSHA calculation. In particular, the seismic catalog, which provides the necessary information that allows the evaluation of the critical b-value, which controls how seismic occurrence distributes with magnitude, has received particular attention. The seismic catalog is the result of the effort of several generations of researchers along the years; therefore, the catalog necessarily suffers from the lack of consistency, homogeneity and completeness for all ranges of magnitude over any seismic study area. Merging the FUNVISIS instrumental catalog with the ones obtained from international agencies, we present the work that we have been doing to produce a consistent seismic catalog that covers Venezuela entirely, with seismic events starting from 1910 until 2012, and report the magnitude of completeness for the different periods. Also, we present preliminary results on the Seismic Hazard evaluation that takes into account such instrumental catalog, the historical catalog, updated known fault geometries and its correspondent parameters, and the new seismic sources that have been defined accordingly. Within the spirit of the Global Earthquake Model (GEM), all these efforts look for possible bridges with neighboring countries to establish consistent hazard maps across the borders.

  4. Sawfishes and Other Elasmobranch Assemblages from the Mio-Pliocene of the South Caribbean (Urumaco Sequence, Northwestern Venezuela).

    PubMed

    Carrillo-Briceño, Jorge D; Maxwell, Erin; Aguilera, Orangel A; Sánchez, Rodolfo; Sánchez-Villagra, Marcelo R

    2015-01-01

    The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats. PMID:26488163

  5. Application of integrated reservoir analysis to design of a waterflood project in Miocene LL3 field, Lake Maracaibo, Venezuela

    SciTech Connect

    Swanson, D.C.; Jam, P.

    1983-03-01

    Integrated Reservoir Analysis is a procedure where interpreted stratigraphic and facies frameworks are combined with structural analysis to produce more accurate and appropriate reservoir maps. The result is a three dimensional interpretation of the thickness, shape, lateral extent, and internal distribution of porosity and permeability in individual reservoir units. The facies framework results from environmental facies analysis and the use of electric log facies. The proper identification of reservoir facies is required for the mapping of reservoir geometry and the determination of the internal distribution of porosity and permeability. Facies-biased contouring techniques and the lateral extension of facies relationships along cross sections were used in the planning and design of a waterflood project by Lagoven, S.A., in fluvial-deltaic clastics of the Miocene La Rosa Formation in the LL3 field, Lake Maracaibo, Venezuela. Important clastic reservoir facies recognized in cores were (1) stream-mouth-bar, (2) distributary-channel-fill, and (3) fluvial point-bar deposits. These environmental facies often occurred in various combinations in deltaic lobes and displayed the electric log shape of the deltaic couplet. The pilot waterflood was designed to inject into stream-mouth-bar facies and withdraw from centrally located distributary-channel-fill deposits with their better porosity and permeability. After one year's operations, radioactive tracers indicate that the flood is operating as designed only at a reduced rate - probably as a result of the clay laminations.

  6. Debris-flow and flooding deposits in coastal Venezuela associated with the storm of December 14-16, 1999

    USGS Publications Warehouse

    Wieczorek, Gerald F.; Larsen, Matthew C.; Eaton, L. Scott; Morgan, Benjamin A.; Blair, J. Luke

    2002-01-01

    Heavy rainfall from the storm of December 14?16, 1999, triggered thousands of shallow landslides on steep slopes of the Sierra de Avila north of Caracas, Venezuela, and caused flooding and massive debris flows in the channels of major drainages that severely damaged coastal communities along the Caribbean Sea. Within this region we characterized geologic conditions where landslides initiated on hillsides and examined the texture of debris-flow deposits in the channels of nine drainages. In one of the most severely damaged areas on a highly developed alluvial fan at Caraballeda, we measured debris-flow deposits that ranged up to 5 meters (m) in thickness, inundating structures and roads over a large portion of the fan. Boulders up to 5 m long were carried along by the flows, impacted structures causing serious damage, and were deposited on the fan. Using field measurements and comparing pre-event and post-event topography from aerial photographs, we determined the volume of debris-flow and flood deposition on the fan to be about 2 million cubic meters. The total volume of material transported and deposited by landslides throughout the Vargas region ranks this as one of the most severe historical erosional events worldwide.

  7. First description of the breeding biology and natural history of the ochre-breasted brush finch atlapetes semirufus in venezuela

    USGS Publications Warehouse

    Biancucci, L.; Martin, T.E.

    2008-01-01

    We provide the first description of the eggs, breeding biology, and natural history of the Ochre-breasted Brush Finch (Atlapetes semirufus). We found 37 nests over four breeding seasons (2004-2007) in Yacamb?? National Park, Venezuela. Nesting activity started in late April and continued until early June suggesting single-brooded behavior despite a typical tropical clutch size of two eggs (x?? = 1.89) that were laid on consecutive days. Egg mass averaged 3.38 g and 11.6% of adult female mass. The incubation and nestling periods averaged 14.9 and 10.5 days, respectively. Only females incubated and the percent time they spent incubating did not change between early and late incubation. Females brooded 42.7% of the time when nestlings were 2 days of age and 20.5% when 9 days of age. Both parents provisioned young at a low rate (3.9 trips/hr) and nestling growth rate (k = 0.45) was also slow. Nest predation rates were relatively high with daily mortality rates of 0.058 and 0.067 during incubation and nestling stages, respectively.

  8. Breeding biology of the Three-striped warbler in Venezuela: A contrast between tropical and temperate parulids

    USGS Publications Warehouse

    Cox, W.A.; Martin, T.E.

    2009-01-01

    We document reproductive life history traits of the Three-striped Warbler (Basileuterus tristriatus) from 146 nests in Venezuela and compare our results to data from the literature for other tropical and temperate parulid species. Mean (?? SE) clutch size was 1.96 ?? 0.03 eggs (n = 96) and fresh egg mass was 2.09 ?? 0.02 g. The incubation period was 15.8 ?? 0.2 days (n = 23) and the nestling period was 10.5 ?? 0.3 days (n = 12). Males did not incubate and rarely provided food for females during incubation. Females had 57 ?? 2% (n = 49) nest attentiveness (% of time on the nest incubating), which caused egg temperature to commonly become cold relative to development. Both adults fed nestlings and feeding rates increased with nestling age. The growth rate constant for nestlings based on mass was K 0.490, which is slower than for north temperate warblers. Predation was the primary source of nest failure and only 22% of nests were successful based on a Mayfield daily predation rate of 0.048 ?? 0.006. Our literature review indicates parulids differ strongly in life histories between temperate and tropical/subtropical sites with species in the tropics having, on average, smaller clutches, longer incubation periods, lower nest attentiveness, longer off-bouts, and longer nestling periods. ?? 2009 by the Wilson Ornithological Society.

  9. Organic geochemical investigation and coal-bed methane characteristics of the Guasare coals (Paso Diablo mine, western Venezuela)

    USGS Publications Warehouse

    Quintero, K.; Martinez, M.; Hackley, P.; Marquez, G.; Garban, G.; Esteves, I.; Escobar, M.

    2011-01-01

    The aim of this work was to carry out a geochemical study of channel samples collected from six coal beds in the Marcelina Formation (Zulia State, western Venezuela) and to determine experimentally the gas content of the coals from the Paso Diablo mine. Organic geochemical analyses by gas chromatography-mass spectrometry and isotopic analyses on-line in coalbed gas samples were performed. The results suggest that the Guasare coals were deposited in a continental environment under highly dysoxic and low salinity conditions. The non-detection of 18??(H)-oleanane does not preclude that the organic facies that gave rise to the coals were dominated by angiosperms. In addition, the presence of the sesquiterpenoid cadalene may indicate the subordinate contribution of gymnosperms (conifers) in the Paleocene Guasare mire. The average coalbed gas content obtained was 0.6 cm3/g. ??13C and D values indicate that thermogenic gas is prevalent in the studied coals. Copyright ?? Taylor & Francis Group, LLC.

  10. A new Dasypodini armadillo (Xenarthra: Cingulata) from San Gregorio Formation, Pliocene of Venezuela: affinities and biogeographic interpretations

    NASA Astrophysics Data System (ADS)

    Castro, Mariela C.; Carlini, Alfredo A.; Sánchez, Rodolfo; Sánchez-Villagra, Marcelo R.

    2014-02-01

    We describe Pliodasypus vergelianus gen. et sp. nov., a Dasypodini armadillo from the middle Pliocene of Venezuela (Vergel Member, San Gregorio Formation). Although scarce, the remains are remarkable because of their geochronologic proximity to the main phase of Great American Biotic Interchange (GABI). The cladistic analysis conducted reveals that Pliodasypus groups with Dasypus and both are sister taxa of Propraopus, whereas Anadasypus is at a basal position. With respect to the records of tribe Dasypodini, after its oldest representative ( Anadasypus, middle and late Miocene), the chronologically subsequent form is Pl. vergelianus (middle Pliocene), followed by Dasypus bellus in higher northern latitudes (late Pliocene), and then by widespread occurrences in the Pleistocene of North America ( D. bellus) and South America ( Propraopus, Dasypus punctatus, and Dasypus novemcinctus). Thus, we infer that Dasypus differentiated in the late Pliocene at low latitudes in the northern South America. It leads to two alternative hypotheses of dispersal: (a) some early Dasypus remained cryptically in South America until the Pleistocene, whereas others dispersed to North America between 2.2 and 2.7 Ma, or (b) they dispersed to North America subsequently to the emersion of the Panamanian isthmus and D. bellus differentiated there; later, during the Pleistocene, D. bellus entered South America and experienced speciation. The same process of re-ingression has been proposed to other xenarthrans, breaking with the traditional assumption that the GABI was unidirectional.

  11. Reproductive biology of the violet-chested hummingbird in Venezuela and comparisons with other tropical and temperate hummingbirds

    USGS Publications Warehouse

    Fierro-Calderon, K.; Martin, T.E.

    2007-01-01

    We provide details on the breeding biology of the Violet-chested Hummingbird (Sternoclyta cyanopectus) based on 67 nests studied in Yacambu?? National Park, Venezuela, from 2002 through 2006. Clutch size was two white eggs, usually laid every other day. Fresh egg mass (0.95 ?? 0.14 g) was 15% of female mass. Incubation and nestling periods were 20.4 ?? 0.3 and 26.0 ?? 0.4 days, respectively. Nest attentiveness increased from 60% in early incubation to 68% in late incubation. The female spent 50% of her time brooding young nestlings, but ceased brooding by 13 days of age. Only the female fed the young, with a low rate of nest visitation (3.3 trips per hour) that did not increase with age of the young. Growth rate based on nestling mass (K = 0.28) was slow. Daily predation rates decreased across stages and were 0.064 ?? 0.044, 0.033 ?? 0.008, and 0.020 ?? 0.006 during the egg-laying, incubation, and nestling periods, respectively. Most, but not all, life history traits of the Violet-chested Hummingbird were similar to those reported for other tropical and temperate hummingbirds, providing further evidence that this family shows a relatively narrow range of life history variation. ?? The Cooper Ornithological Society 2007.

  12. Effect of Environmental Disturbance on the Population of Sandflies and Leishmania Transmission in an Endemic Area of Venezuela

    PubMed Central

    Nieves, Elsa; Oraá, Luzmary; Rondón, Yorfer; Sánchez, Mireya; Sánchez, Yetsenia; Rojas, Masyelly; Rondón, Maritza; Rujano, Maria; González, Nestor; Cazorla, Dalmiro

    2014-01-01

    The exploitation of new wilderness areas with crops is increasing and traditional crop substitution has been modified by new more productive crops. The results show the anthropogenic disturbance effect on the sandflies population and Leishmania transmission in endemic areas of Venezuela. Three agroecosystems with variable degrees of ecological disturbance, forest (conserved), cacao (fragmented), and orangery (disturbed), were selected. Four methods to sandfly capture were used; the specimens were identified and infected with Leishmania. Diversity, population structure, ANOVA, Tukey test, and simple correlation analysis were carried out. Shannon traps were able to capture 94.7% of the total sandflies, while CDC light traps, Sticky traps, and direct suction just captured 2.2%, 1.2%, and 0.9%, respectively. The results showed the effect of ecological disturbance degree on the composition of sandflies and population structure, revealing a dominance level increased but decreased on the diversity and richness of sandflies species in the greatest ecological disturbance area in relation to areas with less organic disturbance. Environments more disturbed cause adaptability of certain species such as Lutzomyia gomezi and Lutzomyia walkeri. These changes on the composition of sandflies population and structure emerging species could cause increasing of leishmaniasis transmission. PMID:24949018

  13. Structure of the Cordillera de la Costa Belt, North-Central Venezuela: Implications for plate tectronic models

    SciTech Connect

    Ave Lallemant, H.G.; Sisson, V.B.; Wright, J.E. )

    1993-02-01

    Preliminary results of an on-going study of the Cordillera de la Costa belt between Puerto Cabello and Choroni, north-central Venezuela, indicate that the deformational history is far more complicated than expected from simple plate-tectonic models. The Cordillera de la Costa belt consists of oceanic rocks (e.g., serpentinites, amphibilites, with lenses of eclogite and blueschist) intimately intermixed with metamorphosed continental margin deposits (e.g., mica and graphite schist, quartzite, marble). Locally, large granitic (basement ) complexes of Lower Paleozoic age are included as well. In late Cretaceous time, the entire belt was involved in four synmetamorphic deformations phases (D[sub 1a] to D[sub 1d]); the first (D[sub 1a]) occurred at depths of at 35-40 km and the later ones at successively shallower depths. This deformation occurred in a subduction zone, related to right-oblique convergence of the Farallon and Atlantic plates. The most penetrative structures resulted from (all in present coordinates) north-south contraction and east-west dextral simple shear (D[sub 1b]). During an Early Tertiary ( ) event (D[sub 2]), the belt was emplaced southward onto the South American continental margin. Subsequent deformational structures (D[sub 3]) resulted in cross folds and faults (with small pull-apart basins) which are consistent with the eastward passage of the Caribbean past the South American plate.

  14. The relationship between mud volcanoes, petroleum migration and accretionary prisms: Lessons from the Caucasus, the Australian margin and Venezuela

    SciTech Connect

    Ware, P.

    1996-08-01

    Mud volcanoes have been widely documented in areas of overpressure where explosive expansion of trapped methane has occurred during argillokinesis. In an area with high sedimentation rate, such as the Gulf of Mexico, there may be no time for fine-grained sediment to de-water before being covered by impermeable material. In an accretionary wedge this process is complicated by overthrusting of off-scraped material which increases the overburden pressure and provides many more avenues for the migration of fluids through the system. In some cases, such as is seen in the Caribbean, the fluids may escape directly to the surface (or seabottom) through high permeability beds. When this happens there may be no diapirism. In other cases, such as in Venezuela, the forearc may be the site of rapid, laterally-derived, sedimentation, and fluids from the overthrusted rocks may be forced to escape through several kilometers of recent deltaic sediments. Since these fluids may include petroleum, this has obvious exploration potential. If there are no suitable reservoir rocks, such as in Timor, there may be no commercial accumulations. However, many giant fields are associated, world-wide, with mud volcanoes, such as those in Azerbaijan.

  15. [Sponges (porifera) distribution along a depth gradient in a coral reef, Parque Nacional San Esteban, Carabobo, Venezuela].

    PubMed

    Núñez Flores, Mónica; Rodríguez-Quintal, José Gregorio; Cristina Díaz, María

    2010-10-01

    Sponges constitute one of the most diverse and abundant animal groups in the marine tropical benthos especially in coral reefs, though poorly studied to species level. The aim of this study is to characterize the sponge community along a depth gradient at Isla Larga (Parque Nacional San Esteban, Venezuela) fringe reef. Net and total sedimentation, roughness index, sponge species richness, density and proportion of the bottom covered by sponges, were evaluated at seven depths (1, 3, 6, 9, 12, 15, 18 m), 17 species were identified grouped in 10 demosponges families. The highest densities and coverage corresponded to 6 m of depth (6.03ind/m2; 11%), that coincides with the lowest net sedimentation and highest substrate heterogeneity. Most abundant species were Desmapsamma anchorata, Amphimedon erina and Scopalina rueztleri. Principal component analysis divided this community in three zones according to depth. The shallow zone of the reef (1 and 3 m), where wave force and high irradiance exert a constant stress sponges, shows the lowest density and coverage by sponges. In contrast, medium depth (6, 9 y 12 m) and deep zone (15 y 18 m) with lower light and sedimentation levels seem to enhance sponge growth and survival that are reflected on the higher densities and coverage of sponges. PMID:21302530

  16. Reassessing the cultural and psychopharmacological significance of Banisteriopsis caapi: preparation, classification and use among the Piaroa of Southern Venezuela.

    PubMed

    Rodd, Robin

    2008-09-01

    Recent attention to the monoamine oxidase inhibiting properties of Banisteriopsis caapi's harmala alkaloids has precluded a balanced assessment of B. caapi's overall significance to indigenous South American societies. Relatively little attention has been paid to the cultural contexts, local meanings and patterns of use of B. caapi among snuff-using societies, such as the Piaroa, who do not prepare decoctions containing N,N-dimethyltryptamine (DMT) admixtures. This article reviews the psychopharmacological literature on B. caapi in light of recent ethnographic work conducted among the Piaroa of southern Venezuela. Piaroa shamans use only B. caapi's cambium, identify at least five distinct varieties of B. caapi, and emphasise the plant's importance for heightening empathy. Some Piaroa people also attribute a range of extra-shamanic uses to B. caapi, including as a stimulant and hunting aid. In light of the psychopharmacological complexity of harmala alkaloids, and ethnographic evidence for a wide range of B. caapi uses,future research should reconsider B. caapi's cultural heritage and psychopharmacological potential as a stimulant and antidepressant-like substance. PMID:19004422

  17. A new baseline for fascioliasis in Venezuela: lymnaeid vectors ascertained by DNA sequencing and analysis of their relationships with human and animal infection

    PubMed Central

    2011-01-01

    Background Human and animal fascioliasis poses serious public health problems in South America. In Venezuela, livestock infection represents an important veterinary problem whereas there appear to be few human cases reported, most of which are passively detected in health centres. However, results of recent surveys suggest that the situation may be underestimated in particular areas. To obtain a baseline for future fascioliasis assessment, studies were undertaken by means of rDNA ITS-2 and ITS-1 and mtDNA cox1 sequencing to clarify the specific status of Venezuelan lymnaeids, their geographical distribution and fascioliasis transmission capacity, by comparison with other American countries and other continents. Results Results obtained completely change the lymnaeid scenario known so far. The relatively rich lymnaeid fauna of Venezuela has been proven to include (i) Lymnaea meridensis and L. neotropica as the only native members, (ii) L. cubensis and Pseudosuccinea columella introduced from the Caribbean area, and (iii) Galba truncatula and L. schirazensis introduced from the Old World. The absence of representatives of the stagnicoline and Radix groups is remarkable. Four species are fascioliasis vectors: G. truncatula, L. cubensis and L. neotropica, which have the capacity to give rise to human endemic areas, and P. columella, which is a source of animal infection and is responsible for the spread of disease. Vector capacity in the apparently highland endemic L. meridensis is to be confimed, although may be expected given its phylogenetic relationships. Similarly as elsewhere, the non-transmitting L. schirazensis has been confused with L. cubensis, also with G. truncatula and possibly with L. neotropica. Conclusions The new scenario leads to the re-opening of many disease aspects. In Venezuela, altitude appears to be the main factor influencing fascioliasis distribution. Human infection shows an altitude pattern similar to other Andean countries, although a differing highland/lowland impact on animal infection does not appear evident. The overlap of G. truncatula, L. cubensis and probably also L. neotropica in temperate and cold zones suggests a higher risk for human infection in mid and high altitude areas. A lymnaeid species mapping by means of DNA markers becomes a priority to determine human and animal fascioliasis distribution in Venezuela, owing to the importance of lymnaeid vectors in defining transmission and epidemiological patterns. PMID:21999170

  18. Hypsilara royi gen. n. and sp. n. (Coleoptera, Elmidae, Larainae) from Southern Venezuela, with a revised key to Larainae of the Western Hemisphere

    PubMed Central

    Maier, Crystal A.; Spangler, Paul J.

    2011-01-01

    Abstract Here we describe a new genus, for a new species of riffle beetle, Hypsilara royi gen. n. and sp. n., from the tepui Cerro de la Neblina in southern Venezuela. This new genus can be distinguished from all other laraine genera by its small size (ca. 4.5 mm) and the presence of a shallow, wide, V-shaped groove across the apical third of the pronotum. An updated key to the genera of Western Hemisphere Larainae is provided, along with information on habitat and collection methods for this taxon. PMID:21998500

  19. Monitoring of Land Deformation Due to Oil Production by InSAR Time Series Analysis Using PALSAR Data in Bolivarian Republic of Venezuela

    NASA Astrophysics Data System (ADS)

    Deguchi, Tomonori; Narita, Tatsuhiko

    2015-05-01

    The target area of this study is the Maracaibo sedimentary basin located in the western part of Bolivarian Republic of Venezuela. The full-scale exploration and development for oil resources in Venezuela which was the greatest oil-producing country in South America had begun at the Maracaibo sedimentary basin in the 1910s, and it was a center of the oil product in Venezuela until the 1980s. But, in most of oil fields in the Maracaibo sedimentary basin, there is concern over the drain on recoverable reserves due to deterioration, and the production amount of petroleum in Venezuela has been diminishing these days. Leveling and GPS surveying were carried out in the past, and they revealed that the large-scale subsidence phenomenon of which cumulative subsidence amount was approximately 5 meter had occurred. The authors applied the vertical displacement measurement by InSAR time series analysis using PALSAR data obtained in the Fine-beam and ScanSAR observation mode. As a result, it could be confirmed clear ground deformation in the surrounding of three oil fields (Tia Juana, Lagunillas and Bachaquero) and easily recognized that the areas of phase anomalies detected by this analysis had expanded and the number of interference fringes had increased over time. The annual velocity of vertical ground surface displacement measured by InSAR time series analysis was -51 mm per year, -103 mm per year and -58 mm per year in Tia Juana, Lagunillas and Bachaquero oil field respectively. The tendency that an earth surface shifted towards the center of phase anomalies was detected from the result of the horizontal ground change measurement. It was interpreted from Google Earth and Landsat images that oil-related facilities (mainly bowling stations) were built intensively over the areas where phase anomalies were detected. Therefore, it was inferred that there was a high association between the operation activity of the oil field and ground deformation. In addition, the deterioration is remarkable in the oil fields of the Maracaibo basin and oil production volume has been declining, on the other hand the spatial volume of the ground surface deformation also showed a clear decreasing trend.

  20. The Siquisique basalts and gabbros, Los Algodones, Venezuela: late Cretaceous oceanic plateau formed within the proto-Caribbean plate?

    NASA Astrophysics Data System (ADS)

    Kerr, A. C.; Neill, I.; Urbani, F.; Spikings, R.; Barry, T.; Tarney, J.

    2009-12-01

    Basalts and gabbros, exposed near Siquisique, Venezuela have previously been interpreted as Jurassic mid-ocean ridge basalts, on the basis of an ammonite found in nearby, but not obviously intercalated, sediments (Bartok, 1985). This, combined with their current tectonic position, well within the continent, and because they accreted before the Cretaceous ‘Great Arc’ of the Caribbean, has led to the Siquisique igneous rocks being widely regarded as Jurassic ‘normal’ mid-ocean ridge basalts and gabbros formed as North and South America rifted apart. We present new geochemical and chronological data which shows that the Siquisique igneous rocks are 95-90Ma and have a chemistry which is more consistent with derivation from a deep mantle plume, than a mid-ocean ridge. It is clear that these basalts represent part of the original ocean floor of the Caribbean, which formed before the tectonic emplacement of the present-day Caribbean from the Pacific. Chemically similar basalts and gabbros at El Copey on Araya Peninsula and Sans Souci in northern Trinidad also accreted to the continental margin of South America before the ‘Great Arc’ of the Caribbean and may well be part of the same intra-Caribbean ‘plume event’. These exposures all indicate that the oceanic crust of the proto-Caribbean, was likely to have consisted (at least in part) of thickened oceanic crust formed by melting of a hot-mantle plume. Although the Siquisique rocks formed at a similar time to the Caribbean-Colombian oceanic plateau they were not derived from the same mantle plume. This supports previous suggestions (Kerr & Tarney, 2005; Snow et al. 2005) that the period around ~90Ma (like that around 120Ma) was marked by a significant upsurge in global plume-related magmatic activity. This activity is likely to have contributed significantly to the major worldwide oceanic anoxia event (OAE2) around the Cenomanian-Turonian boundary (93.4Ma)(Kerr, 1998; Snow et al. 2005). Significantly, this discovery requires a revision of our current understanding of Caribbean plate tectonic evolution. References Bartok, P.E., et al. 1985. The Siquisique Ophiolites, Northern Lara State, Venezuela - a discussion on their Middle Jurassic Ammonites and Tectonic Implications. GSA Bulletin 96, 1050-1055. Kerr, A.C., 1998. Oceanic plateau formation: A cause of mass extinction and black shale deposition around the Cenomanian-Turonian boundary. J Geol Soc London 155, 619-626. Kerr, A.C., Tarney, J., 2005. Tectonic evolution of the Caribbean and northwestern South America: The case for accretion of two Late Cretaceous oceanic plateaus. Geology 33, 269-272. Snow, L.G. et al. 2005. Trace element abundances in the Rock Canyon Anticline, Pueblo, Colorado, marine sedimentary section and their relationship to Caribbean plateau construction and oxygen anoxic event 2. Paleoceanography 20, doi. 10.1029/2004PA001093.

  1. Petrography and U-Pb Zircon Geochronology of Geological Units of the Mesa de Cocodite, Península de Paraguaná, Venezuela

    NASA Astrophysics Data System (ADS)

    Mendi, D.; Baquero, M. L.; Oliveira, E. P.; Urbani, F.; Pinto, J.; Grande, S.; Valencia, V.

    2013-05-01

    Several continental crust units crop out in The Mesa de Cocodite, central Paraguaná Peninsula, Northwestern Venezuela, including a newly mapped quartz-feldspar gneiss that intruded the El Amparo Pluton, a major low-graded metamorphic unit of Permian age. It is unconformably overlying by Late Jurassic phyllites of the Pueblo Nuevo Formation. All these units are cross-cut by narrow dykes. This contribution focuses on the petrography and LA-ICP-MS U-Pb zircon dating of the igneous units, with the aim of constraining magmatism and its tectonic significance in the area. The quartz-feldspar gneiss consists of albite, bluish-smoked quartz, muscovite-chlorite, epidote and zircon. The enclosing El Amparo Pluton is typically a coarse-grained and thick-banded metagranodiorite, containing andesine, quartz, hornblende, epidote, K-feldspar, biotite, chlorite, titanite and zircon. The younger dykes consist of fine-grained, porphyritic hornblende diorites that contain numerous hornblende phenocrysts. The main minerals are andesine, hornblende, quartz, and chlorite. Accessory minerals include zircon, epidote and opaques. A felsic gneiss xenolith collected from the dykes contain quartz, K-feldspar, chlorite, epidote, albite and zircon. Zircon population in the quartz-feldspar gneiss displays a discordia trend, ranging in age from 1050-750 Ma but mostly around 950-900 Ma, which may represent a peak high-grade metamorphism in the area. The El Amparo Pluton provides a concordant Permian age (271.3±6.5 Ma), which is comparable with previous reported U-Pb ages in titanite. Because the porphyry dykes cross-cut all the units in the area, they should be post-Late Jurassic in Age; however, all dated zircons from the dykes are in the range of 1200-750 Ma. The absence of younger ages can be attributed to either formation during a relatively low temperature magmatic event, which generated very narrow younger zircon rims only and thus undetectable with the technique used, or a completely lack of newly generated outer zones due to quick cooling. The emplacement age for the dykes may be early Cenozoic, as for similar basement rocks from the Gulf of Venezuela and the Guajira Peninsula. A felsic-gneiss xenolith enclosed in the dykes contains inherited Proterozoic zircons (1200-950 Ma) with rims of Permian age (270.2±4.1 Ma). Thus, the inherited older ages detected in the feldspar-gneiss unit, the later dykes, and the xenolith indicate the occurrence of Grenvillian crust in Northwestern South America. The Permian ages obtained in the Paraguaná Peninsula are similar to ages reported for the Mérida Andes, Santa Marta Massif, Perijá Range, Orchila Island, northern part of the Maracaibo Basin (Toas Island), northwestern Falcon Basin. Therefore, the Permian magmatic event may have been related to an active margin during the construction of Pangaea, caused by the subduction of oceanic crust under the northwestern corner of South America.

  2. Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type

    USGS Publications Warehouse

    Hackley, P.C.; Martinez, M.

    2007-01-01

    About 7??Mt of high volatile bituminous coal are produced annually from the four coal zones of the Upper Paleocene Marcelina Formation at the Paso Diablo open-pit mine of western Venezuela. As part of an ongoing coal quality study, we have characterized twenty-two coal channel samples from the mine using organic petrology techniques. Samples also were analyzed for proximate-ultimate parameters, forms of sulfur, free swelling index, ash fusion temperatures, and calorific value. Six of the samples represent incremental benches across the 12-13??m thick No. 4 bed, the stratigraphically lowest mined coal, which is also mined at the 10??km distant Mina Norte open-pit. Organic content of the No. 4 bed indicates an upward increase of woody vegetation and/or greater preservation of organic material throughout the life of the original mire(s). An upward increase in telovitrinite and corresponding decrease in detrovitrinite and inertinite illustrate this trend. In contrast, stratigraphically higher coal groups generally exhibit a 'dulling upward' trend. The generally high inertinite content, and low ash yield and sulfur content, suggest that the Paso Diablo coals were deposited in rain-fed raised mires, protected from clastic input and subjected to frequent oxidation and/or moisture stress. However, the two thinnest coal beds (both 0.7??m thick) are each characterized by lower inertinite and higher telovitrinite content relative to the rest of Paso Diablo coal beds, indicative of less well-established raised mire environments prior to drowning. Foreland basin Paleocene coals of western Venezuela, including the Paso Diablo deposit and time-correlative coal deposits of the Ta??chira and Me??rida Andes, are characterized by high inertinite and consistently lower ash and sulfur relative to Eocene and younger coals of the area. We interpret these age-delimited coal quality characteristics to be due to water availability as a function of the tectonic control of subsidence rate. It is postulated that slower subsidence rates dominated during the Paleocene while greater foreland basin subsidence rates during the Eocene-Miocene resulted from the loading of nappe thrust sheets as part of the main construction phases of the Andean orogen. South-southeastward advance and emplacement of the Lara nappes during the oblique transpressive collision of the Caribbean and South American tectonic plates in the Paleocene was further removed from the sites of peat deposition, resulting in slower subsidence rates. Slower subsidence in the Paleocene may have favored the growth of raised mires, generating higher inertinite concentrations through more frequent moisture stress. Consistently low ash yield and sulfur content would be due to the protection from clastic input in raised mires, in addition to the leaching of mineral matter by rainfall and the development of acidic conditions preventing fixation of sulfur. In contrast, peat mires of Eocene-Miocene age encountered rapid subsidence due to the proximity of nappe emplacement, resulting in lower inertinite content, higher and more variable sulfur content, and higher ash yield.

  3. Harold Varmus investido bajo juramento como 14.º director d

    Cancer.gov

    Ganador del Premio Nobel, doctor Harold E. Varmus, prestó juramento hoy como 14.º director del Instituto Nacional del Cáncer (NCI).  "Es muy estimulante que estés de regreso con nosotros", dijo la secretaria del Departamento de Salud y Servicios Humanos K

  4. Cenozoic oblique collision of South American and Caribbean plates: New evidence in the Coastal Cordillera of Venezuela and Trinidad

    SciTech Connect

    Speed, R.C. ); Russo, R.M. ); Foland, K.A. )

    1993-02-01

    The hinterland of the Caribbean Mts. orogen in Trinidad and Venezuela contains schist and gneiss whole protoliths are wholly or partly of continental provenance. The hinterland lies between the foreland thrust belt and terranes. The terranes are alien to continental South America (SA) and may have proto-Caribbean or Caribbean plate origins. The hinterland rocks were widely thought to come from sediments and granitoids of Mesozoic protolithic ages and to be of Cretaceous metamorphic age. Such rocks are now know to be of at least two or more types, as follows: (1) low grade, protoliths of pre-Mesozoic basement and shelfal cover of uncertain age range, inboard locus, Oligocene to mid-Miocene metamorphic ages younging eastward (Caracas, Paria, and Northern Range belts), and (2) higher grade including high P/T, varies protoliths of uncertain age range, Cretaceous and ( )early Paleogene metamorphic ages (Tacagua, Araya, Margarita). The geometry, protoliths, structures, and metamorphic ages of type 1 parautochthoneity and an origin as a thickened wedge of crust-cored passive margin cover. The wedge grew by accretion between about 35 and 20 Ma during oblique transport toward the foreland. The diachroneity of metamorphism implies, as does the timing of foreland deformation, that the wedge evolved in a right-oblique collision between northern SA and terranes moving wholly or partly with the Caribbean plate since the Eocene. Type 2 rocks probably came with the terranes and are products of convergent zone tectonics, either in the proto-Caribbean plate. The hinterland boundaries are brittle thrusts that are out of sequence and imply progressive contraction from mid-Cenozoic to the present.

  5. A multidisciplinary study of the complex Santa Barbara-Furrial oilfields, Northern Monagas area, Eastern Venezuela Basin

    SciTech Connect

    Bojas, B.; Salazar, A.; Robinson, A.; Meunier, M.; Oviedo, P.; Swallow, J.; Diamond, L. )

    1993-02-01

    A multidisciplinary study has been conducted on the giant oilfields located in the northern Monagas area of the eastern Venezuela basin. The oilfields occur in a lower tertiary and Cretaceous sequence which has been heavily tectonized as a consequence of recent transpression along the Caribbean south American plate boundary. This structurally complex area was initially mapped by using 3000 km. Of 2D seismic data. Experience has shown these data to be inadequate and a 150 sq Km 3D survey was acquired over the Santa Barbara area. These data have been interpreted and several new structural features have been identified. As a consequence of this work the structural model has been modified and applied throughout the area. The Cretaceous to late Oligocene sediments, including the Naricual formation which is the main producing horizon, has been studied systematically. These sediments were deposited initially in a fluvial environment which was gradually inundated by successive marine incursions. Approximately 7000 ft of core has been logged and the sedimentary facies and sequence boundaries recognized were then used to calibrate electric logs which allowed facies extrapolation across the whole area. The final parasequence analysis has provided a detailed and reliable reservoir correlation. Original pressure data and subsequent production histories, together with different known oil-water contacts implies separate producing areas. Complex fluid segregations, from condensates to heavy oil had also to be explained. The integration of the geophysical, geological, fluid and production data has allowed each discipline to refine their field models by removing conflicts between these data, thereby producing a better overall description of the reservoir.

  6. New neotropical sebacinales species from a Pakaraimaea dipterocarpacea forest in the Guayana Region, Southern Venezuela: structural diversity and phylogeography.

    PubMed

    Moyersoen, Bernard; Wei?, Michael

    2014-01-01

    Pakaraimaea dipterocarpacea, a member of the Dipterocarpaceae endemic in the Guayana region, is associated with a diverse community of ectomycorrhizal (ECM) fungi. Amongst the 41 ECM fungal species detected in a 400 m2 P. dipterocarpacea ssp. nitida plot in Southern Venezuela, three species belonged to the Sebacinales. We tested whether ECM anatomotype characterization can be used as a feasible element in an integrative taxonomy in this diverse fungal group, where the relevance of fruitbody morphology for species delimitation seems limited. Using a combination of ECM morpho-anatomical characterizations and phylogenetic analyses based on nuclear ITS and LSU sequences, we report three new species. The main distinguishing features of Sebacina guayanensis are the yellowish cell walls together with conspicuous undifferentiated, uniform compact (type B) rhizomorphs. Staghorn-like hyphae are characteristic of S. tomentosa. The combination of clusters of thick-walled emanating hyphae, including hyphae similar to awl-shaped cystidia with basal dichotomous or trichotomous ramifications, and the presence of type B rhizomorphs were characteristic of a third, yet unnamed species. The three species belong to three different, possibly specifically tropical clades in Sebacinales Group A. The geographic distribution of phylogenetically related strains was wide, including a Dicymbe forest in Guyana and an Ecuadorian rainforest with Coccoloba species. We show that ECM morpho-anatomy can be used, in combination with other analyses, to delineate species within Sebacinales Group A. In addition to phylogenetic information, type B rhizomorphs observed in different Sebacinales clades have important ecological implications for this fungal group. The phylogeography of Sebacinales suggests that dispersion and host jump are important radiation mechanisms that shaped P. dipterocarpacea ECM fungal community. This study emphasizes the need for more sequence data to evaluate the hypothesis that phylogeographic relationships between neo- and paleotropical ECM fungal species could be attributed to the vicariance of cross-continental hosts such as the Dipterocarpacae. PMID:25072467

  7. New Neotropical Sebacinales Species from a Pakaraimaea dipterocarpacea Forest in the Guayana Region, Southern Venezuela: Structural Diversity and Phylogeography

    PubMed Central

    Moyersoen, Bernard; Weiß, Michael

    2014-01-01

    Pakaraimaea dipterocarpacea, a member of the Dipterocarpaceae endemic in the Guayana region, is associated with a diverse community of ectomycorrhizal (ECM) fungi. Amongst the 41 ECM fungal species detected in a 400 m2 P. dipterocarpacea ssp. nitida plot in Southern Venezuela, three species belonged to the Sebacinales. We tested whether ECM anatomotype characterization can be used as a feasible element in an integrative taxonomy in this diverse fungal group, where the relevance of fruitbody morphology for species delimitation seems limited. Using a combination of ECM morpho-anatomical characterizations and phylogenetic analyses based on nuclear ITS and LSU sequences, we report three new species. The main distinguishing features of Sebacina guayanensis are the yellowish cell walls together with conspicuous undifferentiated, uniform compact (type B) rhizomorphs. Staghorn-like hyphae are characteristic of S. tomentosa. The combination of clusters of thick-walled emanating hyphae, including hyphae similar to awl-shaped cystidia with basal dichotomous or trichotomous ramifications, and the presence of type B rhizomorphs were characteristic of a third, yet unnamed species. The three species belong to three different, possibly specifically tropical clades in Sebacinales Group A. The geographic distribution of phylogenetically related strains was wide, including a Dicymbe forest in Guyana and an Ecuadorian rainforest with Coccoloba species. We show that ECM morpho-anatomy can be used, in combination with other analyses, to delineate species within Sebacinales Group A. In addition to phylogenetic information, type B rhizomorphs observed in different Sebacinales clades have important ecological implications for this fungal group. The phylogeography of Sebacinales suggests that dispersion and host jump are important radiation mechanisms that shaped P. dipterocarpacea ECM fungal community. This study emphasizes the need for more sequence data to evaluate the hypothesis that phylogeographic relationships between neo- and paleotropical ECM fungal species could be attributed to the vicariance of cross-continental hosts such as the Dipterocarpacae. PMID:25072467

  8. Prediction and verification of possible reef-fish spawning aggregation sites in Los Roques Archipelago National Park, Venezuela.

    PubMed

    Boomhower, J; Romero, M; Posada, J; Kobara, S; Heyman, W

    2010-09-01

    This study attempts to predict and verify possible spawning aggregation sites and times in the Los Roques Archipelago National Park, Venezuela, based on physical reef characteristics and the knowledge of experienced local fishermen. Three possible aggregation sites were selected for monitoring based on satellite images, low-cost bathymetric mapping and interviews with experienced local fishermen. Abundances and sizes of 18 species that are known to form reproductive aggregations were monitored at these sites using underwater visual census for 7 days after each full moon from February to August, 2007. While spawning events were not observed, possible indirect evidence of spawning aggregations was found for Lutjanus analis at Cayo Sal and Boca de Sebastopol, Lutjanus apodus at Cayo Sal, Lutjanus cyanopterus at Cayo Sal and Piedra La Guasa and Epinephelus guttatus at Bajo California and Cayo de Agua. Additionally, indirect evidence was identified for the past existence of a spawning aggregation of Epinephelus striatus in the northern part of the archipelago, which may have been eliminated by overfishing c.15 years ago. Bathymetric mapping showed that the shelf edge at sites monitored in this study was shallower than at spawning aggregation sites in other parts of the Caribbean, and that sites were not proximal to deep water. While this study does not prove the existence or locations of spawning aggregations of reef fishes in the archipelago, it does add insight to a growing understanding of generalities in the relationship between seafloor characteristics and the locations of transient reef-fish spawning aggregations in the Caribbean. PMID:20840614

  9. Morphotype-based characterization of arbuscular mycorrhizal fungal communities in a restored tropical dry forest, Margarita island-Venezuela.

    PubMed

    Fajardo, Laurie; Loveral, Milagros; Arrindell, Pauline; Aguilar, Victor Hugo; Hasmy, Zamira; Cuenca, Gisela

    2015-09-01

    The mycorrhizal component of revegetated areas after ecological restoration or rehabilitation in arid and semiarid tropical areas has been scarcely assessed, particularly those made after mining disturbance. We evaluated and compared the presence of arbuscular mycorrhizal fungi of a small area of restored tropical dry forest destroyed by sand extraction, with a non-restored area of similar age, at the peninsula of Macanao, Margarita Island (Venezuela). Our study was undertaken in 2009, four years after planting, and the mycorrhizal status was evaluated in four restored plots (8 x 12.5 m) (two were previously treated with hydrogel (R2 and R2'), and two were left untreated (R1 and R1'), and four non-restored plots of similar size (NR1 and NR1' with graminoid physiognomy with some scattered shrubs; and NR2 and NR2', with a more species rich plant community). Apparently the restoration management promoted higher arbuscular mycorrhizal fungi (AMF) species richness and diversity, particularly in restored soils where the hydrogel was added (R2 treatment). Soil of the NRI treatment (with a higher herbaceous component) showed the highest spore density, compared to samples of soils under the other treatments. Considering species composition, Claroideoglomus etunicatum and Rhizophagus intraradices were found in all treatments; besides, Diversispora spurca and Funnefformis geosporum were only found in non-restored plots, while members of the Gigasporaceae (a family associated with little disturbed sites) were commonly observed in the plots with restored soils. Mycorrhizal colonization was similar in the restored and non-restored areas, being a less sensitive indicator of the ecosystem recovery. The trend of higher richness and diversity of AMF in the restored plot with hydrogel suggests that this management strategy contributes to accelerate the natural regeneration in those ecosystems where water plays an essential role. PMID:26666138

  10. An extraordinary example of photokarren in a sandstone cave, Cueva Charles Brewer, Chimantá Plateau, Venezuela: Biogeomorphology on a small scale

    NASA Astrophysics Data System (ADS)

    Lundberg, J.; McFarlane, D. A.; Brewer-Carias, C.

    2010-09-01

    A distinctive suite of small-scale erosional forms that are oriented towards the light occur close to the entrance of Cueva Charles Brewer, a large cave in a sandstone tepui, in SE Venezuela. These are the third example of photokarren ever studied in the world, the other two being from Borneo and Ireland. They are the only photokarren ever described from sandstone, and the only example from a non-carbonate environment. The host rock is a poorly-lithified unit of the Precambrian quartz arenite of the Roraima Supergroup. The forms are all oriented towards the light at 30° regardless of rock surface orientation. The primary (negative) erosional form is the tube. Coalescence of tubes results in the positive remnant forms of rods, pinnacles, and cones. The final stage is a bumpy, wavy surface of degraded cones. The size of the features varies with erosion rate, and details of the form vary with development stage. The main population averages 4.4 cm in depth, with 55% of the surface eroded. This is divided into 10% tubes, 70% rods, 10% cones, 5% linear valley and 5% wavy lowland. The micro-ecosystem includes many bacteria, diatoms, red algae, green algae, liverworts, and oribatid mites, but, surprisingly, no cyanobacteria. The presence of a surface biofilm inside the forms but not on the remnant rock surface and, in the non-degraded forms, the direct relationship of biomass with depth suggests that biological activity is the dominant control on development. In addition, direct bacterial corrosion was noted. These same features occur to varying extents in the photokarren of Borneo and Ireland, and the model for development that we present provides a unifying theory for all photokarren. (This study also includes the first published petrographic analysis of uppermost unit of the Mataui Formation).

  11. Seasonal and Interannual variability in Mg/Ca and ?18O of planktonic foraminifera from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Wejnert, K. E.; Thunell, R.; Astor, Y.

    2009-12-01

    Mg/Ca and ?18O has been measured in five planktonic foraminiferal species (Globigerina bulloides, Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) from biweekly sediment trap samples collected in the Cariaco Basin, Venezuela (10o30’ N, 65o31’ W) between May 2003 and September 2007. The Mg/Ca and ?18O data are compared local hydrography to evaluate how well each species tracks seasonal to interannual variability in upper ocean conditions and hence their usefulness in paleoceanographic reconstructions. The oxygen isotope results are consistent with known depth habitats for all five species. The near-surface dwelling G. bulloides and G. ruber display the lowest values with most falling between -0.75 and -1.25. Globigerinoides sacculifer which lives in the upper 50m, displays slightly higher ?18O (-0.5 - -1.0) and the deeper dwelling O. universa and G. menardii have the highest ?18O, predominately ranging from 0.0 to -0.5. Globigerinoides ruber ?18O ranges from -0.60 to -2.02. This equates to a temperature range of approximately 6 oC, which is equivalent to seasonal SST range (23-29 oC) . Temperature estimates derived from species specific equations indicate that G. ruber most accurately tracks sea surface temperature throughout the year. The Mg/Ca data are consistent with the ?18O results (G. bulloides and G. ruber: 4.5 - 6.0; G. sacculifer: 4.0 - 4.5; G. menardii: 2.5 - 3.5) except that O. universa has a relatively high concentration of magnesium (10.0 - 12.0). Mg/Ca and ?18O data will be compared to data collected from a concurrent deep trap to assess the elemental and isotopic changes that may occur during decent through the water column.

  12. Detection and Characterization of Waterborne Gastroenteritis Viruses in Urban Sewage and Sewage-Polluted River Waters in Caracas, Venezuela ?

    PubMed Central

    Rodríguez-Díaz, J.; Querales, L.; Caraballo, L.; Vizzi, E.; Liprandi, F.; Takiff, H.; Betancourt, W. Q.

    2009-01-01

    The detection and molecular characterization of pathogenic human viruses in urban sewage have been used extensively to derive information on circulating viruses in given populations throughout the world. In this study, a similar approach was applied to provide an overview of the epidemiology of waterborne gastroenteritis viruses circulating in urban areas of Caracas, the capital city of Venezuela in South America. Dry season sampling was conducted in sewers and in a major river severely polluted with urban sewage discharges. Nested PCR was used for detection of human adenoviruses (HAds), while reverse transcription plus nested or seminested PCR was used for detection of enteroviruses (HuEVs), rotaviruses (HRVs), noroviruses (HuNoVs), and astroviruses (HAstVs). HRVs were fully characterized with genotype-specific primers for VP4 (genotype P), VP7 (genotype G), and the rotavirus nonstructural protein 4 (NSP4). HuNoVs and HAstVs were characterized by sequencing and phylogenetic analysis. The detection rates of all viruses were ?50%, and all sampling events were positive for at least one of the pathogenic viruses studied. The predominant HRV types found were G1, P[8], P[4], and NSP4A and -B. Genogroup II of HuNoVs and HAstV type 8 were frequently detected in sewage and sewage-polluted river waters. This study reveals relevant epidemiological data on the distribution and persistence of human pathogenic viruses in sewage-polluted waters and addresses the potential health risks associated with transmission of these viruses through water-related environmental routes. PMID:19028907

  13. [Gradients, stability and conservation status of fishes in the Andean mountain streams of the Orinoco versant, Venezuela].

    PubMed

    Rodríguez-Olarte, Douglas; Barrios Gómez, Margenny

    2014-09-01

    Most Andean mountain streams of the Orinoco Basin in Venezuela, had been suffering various disturbances. In spite of this, fish communities have been poorly evaluated in terms of spatial and temporal gradients. Thus, the generation of information about these communities is a priority, since it may support conservation of regional hydrobiological resources. For this, six sites were monthly evaluated in tributaries of upper Turbio River in Sierra de Portuguesa (770-1,305 msnm), during the dry season and the beginning of the rainy season (January-April 2012); we characterized stream dimensions, substrate and water physicochemical variables. Electrofishing was used to determine the number and abundance of fish species. The fish communities and their stability were evaluated by exploring the changes in richness and abundance, coefficients of variation, hierarchical classification and non-metrical multidimensional scaling analysis. The sites conservation status was estimated with a habitat integrity index. Our results showed that richness of the 12 species found varied accord- ing to the mountain elevation, the tributaries and the conservation status of the sites. Chaetostoma dorsale, Creagrutus taphorni and Chaetostoma milesi comprised 90.8% of the relative abundance, and maintained the first ranks during the study period. The communities had little spatio-temporal variation which was associated with a gradient signed principally by the amount of shadow, rocks and gravel cover, water temperature and conductivity. Stability was moderate but varied with elevation and according to site conservation status. The tributaries in upper Turbio River were found to be under severe impacts and their fishes were found impoverished and at risk. PMID:25412531

  14. DSA Analysis of IRM Curves for Hydrocarbon Microseepage Characterization in Oil Fields From Eastern and Western Venezuela

    NASA Astrophysics Data System (ADS)

    Aldana, M.; Costanzo-Alvarez, V.; Gonzalez, C.; Gomez, L.

    2009-05-01

    During the last few years we have performed surface reservoir characterization at some Venezuelan oil fields using rock magnetic properties. We have tried to identify, at shallow levels, the "oil magnetic signature" of subjacent reservoirs. Recent data obtained from eastern Venezuela (San Juan field) emphasizes the differences between rock magnetic data from eastern and western oil fields. These results support the hypothesis of different authigenic processes. To better characterize hydrocarbon microseepage in both cases, we apply a new method to analyze IRM curves in order to find out the main magnetic phases responsible for the observed magnetic susceptibility (MS) anomalies. This alternative method is based on a Direct Signal Analysis (DSA) of the IRM in order to identify the number and type of magnetic components. According to this method, the IRM curve is decomposed as the sum of N elementary curves (modeled using the expression proposed by Robertson and France, 1994) whose mean coercivities vary in the interval of the measured magnetic field. The result is an adjusted spectral histogram from which the number of main contributions, their widths and mean coercivities, associated with the number and type of magnetic minerals, can be obtained. This analysis indicates that in western fields the main magnetic mineralogy is magnetite. Conversely in eastern fields, the MS anomalies are mainly caused by the presence of Fe sulphides (i.e. greigite). These results support the hypothesis of two different processes. In western fields a net electron transfer from the organic matter, degraded by hydrocarbon gas leakage, should occur precipitating Fe(II) magnetic minerals (e.g. magnetite). On the other hand, high concentrations of H2S at shallow depth levels, might allow the formation of secondary Fe-sulphides in eastern fields.

  15. Biological and Phylogenetic Characterization of a Genotype VII Newcastle Disease Virus from Venezuela: Efficacy of Field Vaccination

    PubMed Central

    Perozo, Francisco; Marcano, Rosmar

    2012-01-01

    Here we report the biological and molecular characterization of a virulent genotype VII Newcastle disease virus (NDV) circulating in Venezuela and the assessment of the vaccination efficacy under field conditions compared to controlled rearing conditions. Biological pathotyping showed a mean embryo dead time of 50 h and an intracerebral pathogenicity index of 1.86. Sequence-based phylogenetic analysis demonstrated that the virus belongs to genotype VII in class II (a genotype often found in Asia and Africa), representing the first report of the presence of this genotype in the continent of South America. A vaccine-challenge trial in commercial broilers reared in fields or in a experimental setting included dual (live/killed) priming of 1-day-old chicks plus two live NDV and infectious bursal disease virus (IBDV) field vaccinations at days 7 and 17, followed by a very stringent genotype VII NDV challenge at day 28. Serology for NDV and IBDV, bursal integrity, and protection against NDV lethal challenge were assessed. At 28 days, field vaccinates showed significantly lower NDV (1,356 versus 2,384) and higher IBD (7,295 versus 1,489) enzyme-linked immunosorbent assay (ELISA) antibody titers than the experimentally reared birds. A lower bursal size and bursa-body weight ratio (P < 0.05) and higher bursa lesion score were also detected in the field set. Only 57.1% of field vaccinates survived the lethal challenge, differing (P < 0.05) from 90.5% survival in the experimental farm. Overall, results confirmed the presence of the genotype VII viruses in South America and suggest that field-associated factors such as immunosuppression compromise the efficacy of the vaccination protocols implemented. PMID:22238433

  16. Present-day deformation along the El Pilar Fault in eastern Venezuela: Evidence of creep along a major transform boundary

    NASA Astrophysics Data System (ADS)

    Jouanne, François; Audemard, Franck A.; Beck, Christian; Van Welden, Aurélien; Ollarves, Reinaldo; Reinoza, Carlos

    2011-05-01

    The right-lateral strike-slip El Pilar Fault is one of the major structures that accommodate the relative displacement between the Caribbean and South-America Plates. This fault, which trends East-West along the northeastern Venezuela margin, is a seismogenic source, and shows numerous evidence for active tectonics, including deformation of the Quaternary sediments filling the Cariaco Gulf. Because the main El Pilar Fault strand belongs to a set of strike-slip faults and thrusts between the stable Guyana shield (South) and the Caribbean oceanic floor (North), a GPS network was designed and installed to measure the relative motion of the El Pilar Fault and other faults. The results obtained from the comparison of 2003 and 2005 surveys indicate: (i) a lack of significant displacement (especially shortening) in the Serrania del Interior (Neogene cordillera overthrusted above the Guyana craton), (ii) an eastward displacement (relative to fixed south America plate) up to 22 mm/year of benchmarks located north of the El Pilar Fault. Velocities simulations using dislocations in an elastic half-space show: (1) the concentration along the El Pilar Fault of the whole Caribbean-South America relative displacement, (2) the existence of an important component of aseismic displacement along the upper part of the El Pilar Fault. Between 12 km depth and the surface, only 40% of displacement is locked for the western segment and 50% for the eastern segment. This last phenomenon may be related to the existence of serpentinite lenses along the fault zone as observed for segments of San Andreas and North Anatolian faults.

  17. Late-life depression in Peru, Mexico and Venezuela: the 10/66 population-based study

    PubMed Central

    Guerra, Mariella; Ferri, Cleusa P.; Sosa, Ana Luisa; Salas, Aquiles; Gaona, Ciro; Gonzales, Victor; de la Torre, Gabriela Rojas; Prince, Martin

    2009-01-01

    Background The proportion of the global population aged 60 and over is increasing, more so in Latin America than any other region. Depression is common among elderly people and an important cause of disability worldwide. Aims To estimate the prevalence and correlates of late-life depression, associated disability and access to treatment in five locations in Latin America. Method A one-phase cross-sectional survey of 5886 people aged 65 and over from urban and rural locations in Peru and Mexico and an urban site in Venezuela. Depression was identified according to DSM–IV and ICD–10 criteria, Geriatric Mental State–Automated Geriatric Examination for Computer Assisted Taxonomy (GMS–AGECAT) algorithm and EURO–D cut-off point. Poisson regression was used to estimate the independent associations of sociodemographic characteristics, economic circumstances and health status with ICD–10 depression. Results For DSM–IV major depression overall prevalence varied between 1.3% and 2.8% by site, for ICD–10 depressive episode between 4.5% and 5.1%, for GMS–AGECAT depression between 30.0% and 35.9% and for EURO–D depression between 26.1% and 31.2%; therefore, there was a considerable prevalence of clinically significant depression beyond that identified by ICD–10 and DSM–IV diagnostic criteria. Most older people with depression had never received treatment. Limiting physical impairments and a past history of depression were the two most consistent correlates of the ICD–10 depressive episode. Conclusions The treatment gap poses a significant challenge for Latin American health systems, with their relatively weak primary care services and reliance on private specialists; local treatment trials could establish the cost-effectiveness of mental health investment in the government sector. PMID:19949200

  18. Late Pleistocene and Holocene Hydroclimate Variability in the Tropical Andes from Alpine Lake Sediments, Cordillera de Mérida, Venezuela

    NASA Astrophysics Data System (ADS)

    Larsen, D. J.; Abbott, M. B.; Polissar, P. J.

    2014-12-01

    The tropics play a major role in the global hydrologic cycle and changes to tropical rainfall patterns have critical implications for water resources and ecosystem dynamics over large geographic scales. In tropical South America, late Pleistocene and Holocene precipitation variability has been documented in geologic records and associated with numerous external and internal variables, including changes in summer insolation, South American summer monsoon strength, Pacific Ocean sea surface temperatures, continental moisture recycling, and other climate processes. However, there are few records from the northern hemisphere tropical Americas, a key region for understanding interhemispheric linkages and the drivers of tropical hydroclimate variability. Here, we present a ~13 ka record of coupled hydroclimate and environmental changes from Laguna Brava, a small (~0.07 km2), hydrologically closed lake basin situated at 2400 m asl in the Cordillera de Mérida, Venezuela. Sediment cores collected from varying water depths and proximity to shore are placed in a chronologic framework using radiocarbon ages from terrestrial macrofossils, and analyzed for a suite of physical, bulk geochemical, and stable isotopic parameters. Compound specific hydrogen isotope (D/H) measurements of terrestrial plant waxes (long-chain n-alkanes) show a sharp increase in the late Pleistocene, followed by a long-term trend toward more negative values that suggest a ~20‰ decrease in the D/H ratios of South American tropical precipitation during the Holocene. This pattern is consistent in sign and magnitude to other South American precipitation reconstructions from both hemispheres, indicating interhemispheric similarities in tropical hydroclimate variability. Superimposed on this continent-scale trend are changes in moisture balance and environmental conditions in the Venezuelan Andes. We reconstruct these parameters at Laguna Brava at multidecadal and centennial resolution and evaluate this record within the context of late Pleistocene and Holocene South American tropical hydroclimate variability and global climate changes.

  19. Molecular phylogenetics of the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae): evidence for Pliocene connections between mainland Venezuela and the island of Tobago.

    PubMed

    Jowers, Michael J; Lehtinen, Richard M; Downie, Roger J; Georgiadis, Andrew P; Murphy, John C

    2015-08-01

    The presence of Hyalinobatrachium orientale in Tobago and in northeastern Venezuela is puzzling as this species is unknown from the island of Trinidad, an island often hypothesized to be a stepping-stone for the mainland fauna to colonize Tobago. A period of extended isolation on Tobago could result in the Hyalinobatrachium population becoming distinct from the mainland H. orientale. Here, we use 12S and 16S rDNA gene fragments from nine H. orientale specimens from Tobago and the mainland to assess their relationship and taxonomy, as well as the tempo and mode of speciation. The results suggest H. orientale from Venezuela and Tobago are monophyletic and the two populations diverged about 3 million years ago. This estimate corresponds with the drier climate and lower sea levels of the Pliocene glaciation periods. We hypothesize that lower sea levels resulted in land-bridge formations connecting the mainland and Tobago, with a corridor of habitat allowing H. orientale to colonize Tobago to the west of Trinidad. PMID:24491102

  20. [Distribution of phylogenetic groups and virulence factors in CTX-M-15 ?-lactamase-producing uropathogenic Escherichia coli strains isolated from patients in the community of Mérida, Venezuela].

    PubMed

    Millán, Ysheth; Hernández, Erick; Millán, Beatriz; Araque, María

    2014-01-01

    In this study, the distribution of phylogenetic groups and the genetic detection of virulence factors in CTX-M-15 ?-lactamase-producing uropathogenic Escherichia coli (UPEC) strains were analyzed. Twenty eight strains were isolated between January 2009 and July 2011 from patients with urinary tract infection (UTI) who attended the Public Health Laboratory at Mérida, Venezuela. Determination of phylogenetic groups and detection of six virulence genes, fimH, fyuA, kpsMTII, usp, PAI and papAH, were performed by PCR amplification. Fifteen of the 28 isolates were mainly located in the phylogenetic group A, followed by B2 (12/28) and D (1/28). No direct relationship between the severity or recurrence of UTI and the distribution of phylogroups was observed. All studied virulence factors were found in group B2 strains with the highest frequency. The prevalent virulence profile included the combination of three main genes: fimH, kpsMTII and fyuA and, to a lesser extent, the presence of other determinants such as usp, PAI and/or papAH. These results indicate that virulent UPEC incorporated three important properties: adhesion, iron uptake and evasion of phagocytosis, which favored the production of recurrent UTI. This is the first report describing the association of phylogenetic groups with the potential virulence of CTX-M-15 ?-lactamase producing UPEC strains in Venezuela. PMID:25444124

  1. Water Soluble Organic Nitrogen in atmospheric aerosol samples from urban, sub-urban and pristine areas of Venezuela

    NASA Astrophysics Data System (ADS)

    Canelon, R.; Giuliante, A.; Aguiar, G.; Ghneim, T.; Perez, T.

    2007-12-01

    Concentrations of water soluble organic nitrogen (WSON) were determined in atmospheric total suspended particles (TSP) collected between September of 2005 and May of 2006, in an urban continental (Caracas, 10° 29' 09'' N, 66° 53' 48'' W), an urban coastal (Catia la mar, 10° 35' 47'' N, 67° 01' 45'' W), a sub-urban coastal (Osma, 10° 32' N, 67° 28' W), a suburban continental (Altos de Pipe, 10° 23' 41'' N, 63° 59' 10'' W), a pristine coastal (Isla de Aves, 15° 40' N, 63° 36' W) and a pristine continental (La Gran Sabana National Park, 5° 41' 30'' N, 61° 34' 20'' W) areas of Venezuela. TSP samples were collected using a Hi-Vol airborne particle sampler. TSP were impacted on a fiberglass filter pretreated under 400° C for 4 hours to minimize organic nitrogen contamination. Ultra sound water extractions of the sample filters were performed and their NH4+, NO2- and NO3- concentrations were determined by ion exchange liquid chromatography. The water extracts were UV digested and the nitrogen inorganic ions were analyzed after the UV exposure. WSON concentrations were calculated by the difference between the inorganic nitrogen concentrations before and after UV digestion. Ninety five percent of the aerosol samples collected in the suburban and pristine areas showed a WSON concentration range from 0.03 to 0.6 ?g/m3 whereas in urban areas the range was 0.21 to 1.09 ?g/m3. These concentration values are on the same order of magnitude than the previously found in other tropical and subtropical areas. The contribution of aerosol WSON to the total soluble nitrogen in the coastal urban, sub-urban and pristine areas ranged from 23 to 67%, while in Caracas was smaller (38±8%, n=5). Therefore, aerosol WSON provides an important source of nitrogen to these pristine and suburban ecosystems, which could potentially have implications on the nutrient cycling. There was a statistically significant linear correlation between the aerosol WSON and the water soluble inorganic nitrogen (WSIN) for the urban coastal, sub-urban and pristine zones (R2= 0.81, n=22). This correlation could be explained by a possible source of secondary water soluble organic aerosols derived by the reaction between biogenic volatile organic compounds (VOCs), such as isoprene, and nitrogen oxides (NOx) present in the atmosphere of these regions. Such correlation was not found in Caracas, possibly due to the fact that in this city the major source of VOCs is fossil fuel combustion which produces mostly non soluble aliphatic VOCs. These compounds could most likely produce low water soluble secondary organic nitrogen aerosols.

  2. Prevalence of musculoskeletal disorders and rheumatic diseases in an urban community in Monagas State, Venezuela: a COPCORD study.

    PubMed

    Granados, Ysabel; Cedeño, Ligia; Rosillo, Celenia; Berbin, Sol; Azocar, Miriam; Molina, María Elena; Lara, Onelia; Sanchez, Gloris; Peláez-Ballestas, Ingris

    2015-05-01

    The aim of the study was to determine the prevalence of musculoskeletal disorders and rheumatic diseases in an urban community in Venezuela. We conducted a cross-sectional, community-based study using the COPCORD (Community Oriented Program for Control of Rheumatic Diseases) methodology in subjects older than 18 years. Positive cases were evaluated by rheumatologists. We surveyed 3,973 individuals (1,606 males and 2,367 females), with a mean age of 43.7 years (standard deviation (SD) 17.6). Mean duration of education was 8.9 years (SD 3.7), 79.2 % had a monthly income of?

  3. Geomorphological signature of the Pleistocene thin-skinned tectonics in the northern Maturín Foreland Basin, Eastern Venezuela

    NASA Astrophysics Data System (ADS)

    Fajardo, Atiria; Nivière, Bertrand; Aubourg, Charles; Hervouët, Yves; Wagner, Roberto; Regard, Vincent; Callot, Jean-Paul

    2013-04-01

    The Eastern Venezuela foreland basin and the Serranía del Interior fold-thrust-belt were formed as a consequence of the oblique collision between Caribbean and South American plates. The foreland basin is divided into the Guárico sub-basin in the west and the Maturín sub-basin in the east. The Maturín sub-basin is geologically well known due to geological survey and structural-stratigraphic modeling motived by the hydrocarbon exploration. We focus here on Plio-Pleistocene deformations of the area that remain poorly understood. The study area stands on the northern edge of the Maturín sub-basin, in an area limited by the foothills of the Serranía del Interior to the north, and by the right lateral crustal Urica and San Francisco Faults to the west and east respectively. Between them, from the mountain to the deformation front, the thin-skinned tectonic wedge is mainly structured above the Pirital and Furrial thrust faults. The Pirital thrust fault involves a thick lithographic section that includes presumably pre-Cretaceous rocks whereas the Furrial Thrust is shallower and is associated with fault-bend-folds structures. We support that the Maturín sub-basin remains an area of active continental shortening in which a post-Pliocene peneplain surface has been deformed by folds, which are developed above buried reverse faults. We use the drainage patterns in this region to show active deformations that would be difficult to identify by other means. In particular we show how uplifts and tilts associated to fault activity alter the drainage pattern and the geometry of remnant terraces near Tarragona, San Felix, Punta de Mata, El Tejero and Jusepín zones. Given age, dip angles of the faults, and the vertical throw determined from the offset of the terrace and peneplain surfaces across the surface fault traces, we aim to estimate the cumulative shortening along the direction of tectonic transport and slip rates. Industrial seismic lines show that superficial deformations are not systematically connected to fault in depth. This raise the question (1) of the origin of the ongoing shortening in the tectonic wedge and (2) of the potentiality of a strain partitioning between thick-skinned and thin-skinned active deformations.

  4. Seasonal variability in B speciation and B/Ca in planktonic foraminifera from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Wejnert, K. E.; Thunell, R.; Bizimis, M.; Pellechia, P. J.; Astor, Y.

    2011-12-01

    We determined B/Ca on four planktonic foraminiferal species (Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) on a Thermo Element 2 high resolution ICP-MS. The material is from biweekly sediment trap samples collected in Cariaco Basin, Venezuela (10o30' N, 65o31' W) over a three year period between May 2003 and May 2006. The data are compared to local hydrography and water column chemistry to evaluate environmental controls on B incorporation into foraminiferal calcite. In addition, seasonal variability of B speciation in the foraminiferal calcite is assessed using 11B magic angle spinning (MAS) nuclear magnetic resonance (NMR) on samples of O. universa from January, February, and April 2007 and of G. menardii from December 2006. The B/Ca (?mol/mol) data displays clear depth stratification with the surface dwelling G. ruber having the highest B/Ca (202 - 455), followed by G. sacculifer (137 - 335) and the deeper dwelling G. menardii and O. universa having the lowest (102 - 281; 109 - 222 respectively), consistent with a decrease in pH with depth. The data also show a repeatable seasonal pattern with the highest values occurring when the water column is stratified in June and July and the lowest occurring during upwelling in December and January. However, none of the environmental variables have a strong correlation with B/Ca. The 11B MAS NMR O. universa data show a seasonal change in the speciation of B within the foraminiferal calcite. During January the boron is almost entirely incorporated (~ 90%) in a previously unrecognized trigonal form. However, in April only ~75% of the boron is in this trigonal form, whereas the rest of the boron is divided evenly between borate and boric acid. The observed trigonal form has a Cq of 3.0, which is similar to the theoretical value of 3.15 for the corner-sharing borate carbonate complex, B(OH2)CO3-. It is hypothesized that during calcification boron is converted to a borate carbonate complex, which is ultimately converted to either borate or boric acid with each equally likely. Our results support this hypothesis except that most of the boron does not complete this reaction, but remains in the intermediate borate carbonate complex form. The December G. menardii sample matches the January O. universa sample indicating there is no species difference with respect to the form of boron incorporated into the foraminiferal test.

  5. Earthquake source imaging by high-resolution array analysis at regional distances: the 2010 M7 Haiti earthquake as seen by the Venezuela National Seismic Network

    NASA Astrophysics Data System (ADS)

    Meng, L.; Ampuero, J. P.; Rendon, H.

    2010-12-01

    Back projection of teleseismic waves based on array processing has become a popular technique for earthquake source imaging,in particular to track the areas of the source that generate the strongest high frequency radiation. The technique has been previously applied to study the rupture process of the Sumatra earthquake and the supershear rupture of the Kunlun earthquakes. Here we attempt to image the Haiti earthquake using the data recorded by Venezuela National Seismic Network (VNSN). The network is composed of 22 broad-band stations with an East-West oriented geometry, and is located approximately 10 degrees away from Haiti in the perpendicular direction to the Enriquillo fault strike. This is the first opportunity to exploit the privileged position of the VNSN to study large earthquake ruptures in the Caribbean region. This is also a great opportunity to explore the back projection scheme of the crustal Pn phase at regional distances,which provides unique complementary insights to the teleseismic source inversions. The challenge in the analysis of the 2010 M7.0 Haiti earthquake is its very compact source region, possibly shorter than 30km, which is below the resolution limit of standard back projection techniques based on beamforming. Results of back projection analysis using the teleseismic USarray data reveal little details of the rupture process. To overcome the classical resolution limit we explored the Multiple Signal Classification method (MUSIC), a high-resolution array processing technique based on the signal-noise orthognality in the eigen space of the data covariance, which achieves both enhanced resolution and better ability to resolve closely spaced sources. We experiment with various synthetic earthquake scenarios to test the resolution. We find that MUSIC provides at least 3 times higher resolution than beamforming. We also study the inherent bias due to the interferences of coherent Green’s functions, which leads to a potential quantification of biased uncertainty of the back projection. Preliminary results from the Venezuela data set shows an East to West rupture propagation along the fault with sub-Rayleigh rupture speed, consistent with a compact source with two significant asperities which are confirmed by source time function obtained from Green’s function deconvolution and other source inversion results. These efforts could lead the Venezuela National Seismic Network to play a prominent role in the timely characterization of the rupture process of large earthquakes in the Caribbean, including the future ruptures along the yet unbroken segments of the Enriquillo fault system.

  6. [Allelic variants of the CYP2D6: *4, *6 and *10 in a sample of resident from the Aragua state, Venezuela].

    PubMed

    Flores-Angulo, Carlos; Villegas, Cecilia; Mora, Yuselin; Martínez, José Antonio; Oropeza, Teresa; Moreno, Nancy

    2015-12-01

    The aim of this study was to determine the CYP2D6: * 4, * 6 and * 10 gene variants frequency and to predict the metabolizer phenotype in a sample of 145 unrelated apparently healthy individuals residing in the state of Aragua, Venezuela. Genotypes were determined by Polymerase chain reaction assays followed by restriction endonucleases digestion. The metabolizer phenotype prediction was made based on the activity score system. The frequencies of CYP2D6 * 4, * 6 and * 10 allelic variants were 14.5%, 0.3% and 1%. A significant percentage of individuals were categorized as heterozygote-extensive/intermediate (23.5%) and poor metabolizers (4.1%), this information has potential clinical impact, because the CYP2D6 protein is involved in the metabolism of drugs frequently prescribed as: carvedilol, captopril, chloroquine, codeine, fluoxetine, fluvastatin, haloperidol, idarubicin, indinavir, imatinib, loperamide, nifedipine, ondansetron and tamoxifen. PMID:26732924

  7. Complete genome sequence of Jacquemontia yellow mosaic virus, a novel begomovirus from Venezuela related to other New World bipartite begomoviruses infecting Convolvulaceae.

    PubMed

    Fiallo-Olivé, Elvira; Chirinos, Dorys T; Geraud-Pouey, Francis; Moriones, Enrique; Navas-Castillo, Jesús

    2014-07-01

    The complete genome of a bipartite begomovirus (genus Begomovirus, family Geminiviridae) infecting Jacquemontia sp. (Convolvulaceae) in Venezuela has been cloned and sequenced. Sequence comparison and phylogenetic analysis have shown that it represents an isolate of a novel species with closest relatives being two New World bipartite begomoviruses that infect Convolvulaceae, Jacquemontia mosaic Yucatan virus and Merremia mosaic virus. The DNA-As of these begomoviruses, however, share only 77.0-78.4 % nucleotide sequence identity with the DNA-A of the isolate described here, for which a recombinant origin is suggested. Based on the symptoms observed in the field, the name Jacquemontia yellow mosaic virus (JacYMV) is proposed for this novel bipartite begomovirus. PMID:24463954

  8. Description of two new species of Rissoella Gray, 1847 (Mollusca, Gastropoda, Heterobranchia) from Venezuela, with a key to the Caribbean species known for the genus

    PubMed Central

    Caballer, Manuel; Ortea, Jesus; Narciso, Samuel

    2011-01-01

    Abstract Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensis sp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicola sp. n. Rissoella morrocoyensis sp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon and it lives on the leaves of the seagrass Thalassia testudinum Banks & König, 1805. Rissoella venezolanicola sp. n. has an angled preumbilical cord which extends to the columella delimiting a trapezoid, a hypobranchial gland marked by a yellow quaver-shaped ribbon and protoconch with fuchsia highlights. It lives on the brown alga Dictyota spp. The records of Rissoella in the Caribbean are revised and illustrations, a comparative table and a key to the Caribbean species known for the genus are provided. PMID:21976997

  9. 10Be dating of river terraces of Santo Domingo river, on Southeastern flank of the Mérida Andes, Venezuela: Tectonic and climatic implications

    NASA Astrophysics Data System (ADS)

    Guzmán, Oswaldo; Vassallo, Riccardo; Audemard, Franck; Mugnier, Jean-Louis; Oropeza, Javier; Yepez, Santiago; Carcaillet, Julien; Alvarado, Miguel; Carrillo, Eduardo

    2013-12-01

    In this study, we discuss the first cosmogenic 10Be dating of river terraces located in the lower reaches of the Santo Domingo river (Southeastern flank of the Mérida Andes, Western Venezuela). The geomorphic observations and dating allowed the restoration of the temporal evolution of incision rate, which was analysed in terms of tectonic, climatic and geomorphic processes. The long-term incision rate in the area has been constantly around 1.1 mm/a over the last 70 ka. Taking into account the geologic and geomorphologic setting, this value can be converted into the Late Pleistocene uplift rate of the Southeastern flank of the Mérida Andes. Our results show that the process of terraces formation in the lower reaches of the Santo Domingo river occurred at a higher frequency (103-104 years) than a glacial/interglacial cycle (104-105 years). According to the global and local climate curve, these terraces were abandoned during warm to cold transitions.

  10. Long-term effect of mass chemotherapy, transmission and risk factors for Schistosoma mansoni infection in very low endemic communities of Venezuela.

    PubMed

    Hofstede, Stefanie N; Tami, Adriana; van Liere, Genevieve A F S; Ballén, Diana; Incani, Renzo N

    2014-12-01

    The prevalence of Schistosoma mansoni infection in Venezuela has changed from high to low due mostly to successful control activities, including mass chemotherapy and molluscicide applications. This study examined the impact of mass chemotherapy on S. mansoni transmission and risk factors for infection 12 years after administration of praziquantel in Venezuela. Two relatively isolated rural communities were studied, one with snail control (Manuare) and the second without (Los Naranjos). A cross-sectional survey of randomly selected households included 226 (Manuare) and 192 (Los Naranjos) consenting participants. S. mansoni prevalence was determined using a combination of coprological (Kato-Katz) and serological (circumoval precipitin test, alkaline phosphatase immunoassay and Western blot) tests. Data on epidemiological and socioeconomic risk factors were obtained through individual structured interviews. Univariate analysis and multivariate logistic regression models identified independent risk factors for infection. Water sites were examined for the presence of Biomphalaria glabrata snails. Only one participant was positive by coprology. The overall prevalences according to the combined tests were 32.7% in Manuare and 26.6% in Los Naranjos. Lower prevalences (12.7% in Manuare and 13.2% in Los Naranjos) were found in children <12 years of age representing those born after mass chemotherapy. Social demographic variables associated with infection in both communities were older age (>25 years), contact with specific water sites, and being a farmer/non-specialised worker. Mass treatment with praziquantel applied once to endemic communities led to an important and long-lasting sustained reduction of S. mansoni infections independent of the application of snail control. A degree of low active transmission of S. mansoni persisted in the treated areas which was associated with similar factors in both communities. PMID:25128702

  11. Long term in-situ observations of biomass burning aerosol at a high altitude station in Venezuela - sources, impacts and inter annual variability

    NASA Astrophysics Data System (ADS)

    Hamburger, T.; Matis?ns, M.; Tunved, P.; Ström, J.; Calderon, S.; Hoffmann, P.; Hochschild, G.; Gross, J.; Schmeissner, T.; Krejci, R.

    2013-05-01

    First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron aerosol volume, number concentrations of primary particles and particle absorption were observed. Orographic lifting and shallow convection leads to a distinct diurnal cycle at the station. It enables measurements within the lower free troposphere during night time and observations of boundary layer air masses during day time and at their transitional regions. The seasonal cycle is defined by a wet rainy season and a dry biomass burning season. The particle load of biomass burning aerosol is dominated by fires in the Venezuelan savannah. Increases of aerosol concentrations could not be linked to long-range transport of biomass burning plumes from the Amazon basin or Africa due to effective wet scavenging of particles. Highest particle concentrations were observed within boundary layer air masses during the dry season. Ambient sub-micron aerosol volume reached 1.4 ± 1.3 ?m3 cm-3, heated (300 °C) particle number concentrations 510 ± 420 cm-3 and the absorption coefficient 0.91 ± 1.2 Mm-1. The respective concentrations were lowest within the lower free troposphere during the wet season and averaged at 0.19 ± 0.25 ?m3 cm-3, 150 ± 94 cm-3 and 0.15 ± 0.26 Mm-1. A decrease of particle concentrations during the dry seasons from 2007-2009 could be connected to a decrease in fire activity in the wider region of Venezuela using MODIS satellite observations. The variability of biomass burning is most likely linked to the El Niño-Southern Oscillation (ENSO). Low biomass burning activity in the Venezuelan savannah was observed to follow La Niña conditions, high biomass burning activity followed El Niño conditions.

  12. Long-term in situ observations of biomass burning aerosol at a high altitude station in Venezuela - sources, impacts and interannual variability

    NASA Astrophysics Data System (ADS)

    Hamburger, T.; Matis?ns, M.; Tunved, P.; Ström, J.; Calderon, S.; Hoffmann, P.; Hochschild, G.; Gross, J.; Schmeissner, T.; Wiedensohler, A.; Krejci, R.

    2013-10-01

    First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron particle volume, number concentrations of primary particles and particle absorption were observed. Orographic lifting and shallow convection leads to a distinct diurnal cycle at the station. It enables measurements within the lower free troposphere during night-time and observations of boundary layer air masses during daytime and at their transitional regions. The seasonal cycle is defined by a wet rainy season and a dry biomass burning season. The particle load of biomass burning aerosol is dominated by fires in the Venezuelan savannah. Increases of aerosol concentrations could not be linked to long-range transport of biomass burning plumes from the Amazon basin or Africa due to effective wet scavenging of particles. Highest particle concentrations were observed within boundary layer air masses during the dry season. Ambient sub-micron particle volume reached 1.4±1.3 ?m3 cm-3, refractory particle number concentrations (at 300 °C) 510±420 cm-3 and the absorption coefficient 0.91±1.2 Mm-1. The respective concentrations were lowest within the lower free troposphere during the wet season and averaged at 0.19±0.25 ?m3 cm-3, 150±94 cm-3 and 0.15±0.26 Mm-1. A decrease of particle concentrations during the dry seasons from 2007-2009 could be connected to a decrease in fire activity in the wider region of Venezuela using MODIS satellite observations. The variability of biomass burning is most likely linked to the El Niño-Southern Oscillation (ENSO). Low biomass burning activity in the Venezuelan savannah was observed to follow La Niña conditions, high biomass burning activity followed El Niño conditions.

  13. Reproductive phenology of 233 species from four herbaceous–shrubby communities in the Gran Sabana Plateau of Venezuela

    PubMed Central

    Ramírez, Nelson; Briceño, Herbert

    2011-01-01

    Background and aims Herbaceous–shrubby communities in the Gran Sabana (Great Savanna) Plateau of Venezuela grow under non-zonal conditions. We speculated that this would produce specific patterns of reproductive phenology within these different soil–climate–vegetation associations. Specifically, we tested the hypothesis that the reproductive phenology patterns of four herbaceous–shrubby communities are determined by climate, plant life-forms and soil properties. Methodology The reproductive phenology of 233 plant species of the Gran Sabana Plateau of the Venezuelan Guayana Highlands was studied taking into account their life-forms (i.e. trees, shrubs, climbers, annual herbs, perennial herbs, epiphytes and parasites/hemiparasites) in four herbaceous–shrubby communities: (i) shrubland, (ii) secondary bush, (iii) savanna and (iv) broad-leaved meadow. Patterns of flowering, and occurrence of unripe fruit and ripe fruit were studied at two levels of intensity for 24 months within a 5-year span. Two phenological records for each month of the year and between two and four replicates for each community type were made. Randomly selected 2–3 ha plots were used. General phenological patterns were established using <25% of the plants of each species in each plot to give the total duration of each phenological phase. High-intensity phenological patterns were established using >25% of individuals in each plot to establish times of high abundance of flowers, and presence of unripe fruit and/or ripe fruit on individual plants. This generated phenological peaks for each species. Principal results Non-seasonality of general flowering and unripe fruiting in each of the four communities was related to non-seasonal flowering and unripe fruiting patterns in the plant life-forms studied and to low variation in precipitation throughout the year. Flowering activity in the shrubland and broad-leaved meadow peaked twice. The bush community had only one flowering peak while the savanna gave a non-seasonal flowering peak. The peak unripe fruiting pattern was not clearly related to unripe fruit phenological patterns of the most abundant life-forms. Unripe fruit patterns and precipitation were only correlated for shrubs, climbers and trees in the shrubland. Ripe fruiting patterns peaked during the short-dry season in the bush and shrubland, and were negatively correlated with precipitation in the shrubland. General and peak ripe fruiting patterns were non-seasonal in the savanna and broad-leaved meadow and related to the dominance of herbaceous species with prolonged ripe fruiting times, low climate seasonality, high plant species richness and diversity, and dispersal syndromes. Conclusions The reproductive phenology of the herbaceous–shrubby communities is mainly influenced by the composition of the life-forms, the precipitation regime and soil type. PMID:22476484

  14. Seasonal variability in multi-elemental ratios and ?18O in planktonic foraminifera from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Wejnert, K. E.; Thunell, R.; Bizimis, M.; Astor, Y.

    2010-12-01

    Multi-elemental ratios (Mg/Ca, Mg/Li, Li/Ca, B/Ca, U/Ca, P/Ca, Cd/Ca, and Zn/Ca) of four planktonic foraminiferal species (Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) have been measure on a Thermo Element 2 inductively coupled plasma mass spectrometer (ICP-MS) and ?18O measurements have been taken on a GV ISOPRIME stable isotope ratio mass spectrometer. The material is from biweekly sediment trap samples collected in the Cariaco Basin, Venezuela (10o30’ N, 65o31’ W) between May 2003 and May 2004. The data are compared to local hydrography and water column chemistry to evaluate each proxy’s applicability in reconstructing past ocean conditions. The oxygen isotope results are consistent with known depth habitats for all five species. The surface dwelling G. ruber displays the lowest values of -0.84 and -1.76‰. G. sacculifer which lives in the upper 50m, displays slightly higher ?18O (-0.55 - -1.39‰) and the deeper dwelling O. universa and G. menardii have the highest ?18O, predominately ranging from 0.0 to -1.0‰. The G. ruber ?18O range equates to a temperature range of approximately 4.5 oC, which is equivalent to seasonal SST range (24.5-29 oC). Temperature estimates derived from species specific equations indicate that G. ruber most accurately tracks SST throughout the year. The temperature proxies, Mg/Ca (mmol/mol) and Mg/Li (mol/mmol), also reflect these different depth habitats (G. ruber: 4.1 - 6.9, 0.3 - 0.5; G. sacculifer: 2.9 - 4.3, 0.2 - 0.4; G. menardii: 1.9 - 4.3, 0.1 - 0.3) except that O. universa has a relatively high concentration of magnesium (7.1 - 13.1, 0.8 - 1.6). With these proxies, G. sacculifer most accurately reflects SST for both Mg/Ca and Mg/Li. For Li/Ca (µmol/mol) G. ruber has the highest ratios (13.2 - 18.5) and O. universa has the lowest (7.1 - 11.6). All of the species show an inverse relationship between temperature and Li/Ca with G. ruber most accurately recording SST. The pH proxy, B/Ca (µmol/mol), displays clear depth stratification with G. ruber having the highest B/Ca (246 - 360) and G. menardii and O. universa the lowest (102 - 230), consistent with a decrease in pH with depth. However, the other pH proxy, U/Ca shows no inter-species variation with all species having U/Ca values between 8 and 27 nmol/mol, which suggests that U incorporation is controlled by additional factors. All of the species display higher average values of the nutrient proxies P/Ca (mmol/mol), Cd/Ca (µmol/mol), and Zn/Ca (µmol/mol) during the winter upwelling than during non-upwelling, which is consistent with the nutrient distributions in the water column. None of the proxies show a significant relationship with measured phosphate concentrations; however this may be a result of uniformly low phosphate concentrations in the mixed layer.

  15. Venezuela's Bolivarian Schools Project.

    ERIC Educational Resources Information Center

    Diaz, Maria Magnolia Santamaria

    2002-01-01

    Discusses efforts by the Venezuelan government to improve the nation's school infrastructure through the Bolivarian Schools Project administered by the Ministry of Education, Culture and Sport. The project set educational principles which are guiding current school building efforts. (EV)

  16. Analysis of factors influencing the overall effect of racecadotril on childhood acute diarrhea. Results from a real-world and post-authorization surveillance study in Venezuela

    PubMed Central

    Chacón, Jose

    2010-01-01

    Drug efficacy might differ from clinical trial results when performed in clinical daily conditions. Therefore, it is mandatory to conduct trials about effectiveness to improve external validity. This post-authorization, open-label, noncontrolled, prospective, multicenter, observational, and naturalistic trial was designed to search for factors influencing the racecadotril overall effect on childhood acute watery diarrhea in a real-world setting of Venezuela. There were 3,873 children with acute watery diarrhea treated with racecadotril, an enkephalin breakdown blocker plus oral rehydration therapy by 97 pediatricians. Evaluations were carried out daily until emission of two consecutive formed stools or absence of watery bowel movements for 24 hours. The primary end-point was time-to-relief, defined as the time from first racecadotril dose to the last watery bowel movement time. Age, gender, nursing type, nursing status during diarrhea, diarrhea severity, and co-medication were considered as factors in the statistical analysis. The primary end-point was evaluated by factors using UNIANOVA, and post-hoc tests were done. A multiple regression analysis was carried out to identify factors affecting drug performance, racecadotril effectiveness and tolerability overall assessment was searched by physicians and patients, and inter-observer agreement was evaluated by kappa statistics. The mean time-to-relief was 18.5 ± 12.5 hours [95% confidence interval 17.9–19.0] and the diarrhea severity was the only variable with significant and independent weight on racecadotril effectiveness explaining 23% of time-to-relief variance, but even in severe diarrhea cases this time was less than 24 hours. High agreement about satisfactory perception on effectiveness and tolerability was reached among physicians and patients. In conclusion, the racecadotril overall effect, evaluated in a real-world setting of Venezuela, was in agreement with results of some earlier controlled trials. It was only influenced by severity of diarrhea episode, as well as being considered an effective and well tolerated treatment by physicians and patients. PMID:20668711

  17. Effects of land use change and seasonality of precipitation on soil nitrogen in a dry tropical forest area in the Western Llanos of Venezuela.

    PubMed

    González-Pedraza, Ana Francisca; Dezzeo, Nelda

    2014-01-01

    We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen. PMID:25610907

  18. [Detection of Entamoeba histolytica and Entamoeba dispar by PCR in children, less than five years of age with diarrhea, in Maracaibo, Venezuela. A preliminary study].

    PubMed

    Bracho Mora, Angela; Rivero de Rodríguez, Zulbey; Arraiz, Nailet; Villalobos, Rafael; Urdaneta, Haydee

    2013-12-01

    To determine the prevalence of Entamoeba histolytica as a producer of diarrhea, a study was conducted in children, less than five years of age, with diarrhea who attended several out patient clinics of the Servicio Aut6nomo Hospital Universitario, Maracaibo, Venezuela. A macroscopic and microscopic examination with physiological saline, lugol and Kinyoun staining were performed to the stool samples obtained. The remainder of the sample was frozen until DNA extraction, and PCR amplification was performed separately for E. histolytica and E. dispar. Microscopic examination showed no trophozoites and/or cysts of Entamoeba histolytica/dispar/moshkovskii, or intestinal coccidians in any of the 50 samples analyzed. Parasites detected were Giardia lamblia (6%), Blastocystis sp. (4%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) and Trichuris trichiura (2%). By PCR, six samples (12%) had DNA of E. dispar and two (4%) had DNA from E. histolytica; no child showed association of both amoebae. The two children who had E. histolytica were one-year-old. E. dispar was detected in younger children. We suggest that the prevalence of E. histolytica in children under five years is really low. PMID:24502179

  19. CO{sub 2} emissions from developing countries: Better understanding the role of Energy in the long term. Volume 2, Argentina, Brazil, Mexico, and Venezuela

    SciTech Connect

    Ketoff, A.; Sathaye, J.; Goldman, N.

    1991-07-01

    Recent years have witnessed a growing recognition of the link between emissions of carbon dioxide (CO{sub 2}) and changes in the global climate. Of all anthropogenic activities, energy production and use generate the single largest portion of these greenhouse gases. Although developing countries currently account for a small share of global carbon emissions, their contribution is increasing rapidly. Due to the rapid expansion of energy demand in these nations, the developing world`s share in global modern energy use rose from 16 to 27 percent between 1970 and 1990. If the growth rates observed over the past 20 years persist energy demand in developing will surpass that in the countries of the Organization for Economic Cooperation and Development (OECD) early in the 21st century. The study seeks to examine the forces that galvanize the growth of energy use and carbon emissions, to assess the likely future levels of energy and CO{sub 2} in selected developing nations and to identify opportunities for restraining this growth. The purpose of this report is to provide the quantitative information needed to develop effective policy options, not to identify the options themselves. These individual studies were conducted fro Argentina, Brazil, Mexico and Venezuela in Latin America.

  20. Deep-seated gravitational slope deformations along the active Boconó Fault in the central portion of the Mérida Andes, western Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A.; Beck, Christian; Carrillo, Eduardo

    2010-12-01

    Two very large deep-seated gravitational slope deformations in the highlands of the Mérida Andes, Venezuela, are herein described: the Mucubají Pass and Cerro La Camacha. These slope movements have slid in post-Last Glacial Maximum times. In addition, both landslides are in very close association with the active Boconó Fault trace. The Cerro La Camacha (Camacha Range) landslide is fault bounded along its northwest flank, whereas the Mucubají pass mass movement is even cut by the active fault trace. The almost 10 km long Mucubají slide mobilizes LGM moraine deposits along the unconformable basement contact. La Camacha slope movement is a sackung-type landslide, involving two huge masses that affect the entire northwestern slope of the La Camacha Range. This sackung is at least 20 km long, paralleling the active Boconó Fault trace. Combination of high relief energy (gravitational forces) and seismic shaking related to an on-site active fault could be responsible for the destabilization of the slopes or massif in both cases. Although the seismically-induced (re-)activation of the La Camacha landslide is very likely, there is no proof for that yet. Conversely, the Mucubají slide shows geomorphic, geodetic and sedimentary evidence of episodic activity in recent times, which could be ascribed to seismic triggering. In the particular case of the La Camacha sackung, the combination of dextral slip along the Boconó Fault and a SE-dipping fault plane could additionally favor the destabilization of the NW slope of the La Camacha Range.

  1. Analysis of number size distributions of tropical free tropospheric aerosol particles observed at Pico Espejo (4765 m a.s.l.), Venezuela

    NASA Astrophysics Data System (ADS)

    Schmeissner, T.; Krejci, R.; Ström, J.; Birmili, W.; Wiedensohler, A.; Hochschild, G.; Gross, J.; Hoffmann, P.; Calderon, S.

    2011-04-01

    The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere (FT) were performed from March 2007 until March 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l. nearby the city of Mérida, Venezuela. Aerosol size distribution and number concentration data was obtained with a custom-built Differential Mobility Particle Sizer (DMPS) system and a Condensational Particle Counter (CPC). The analysis of the annual and diurnal variability of the tropical FT aerosol focused mainly on possible links to the atmospheric general circulation in the tropics. Considerable annual and diurnal cycles of the particle number concentration were observed. Highest total particle number concentrations were measured during the dry season (January-March, 519 ± 613 cm-3), lowest during the wet season (July-September, 318 ± 194 cm-3). The more humid FT (relative humidity (RH) range 50-95 %) contained generally higher aerosol particle number concentrations (573 ± 768 cm-3 during dry season, 320 ± 195 cm-3 during wet season) than the dry FT (RH < 50 %, 454 ± 332 cm-3 during dry season, 275 ± 172 cm-3 during wet season), indicating the importance of convection for aerosol distributions in the tropical FT. The diurnal cycle in the variability of the particle number concentration was mainly driven by local orography.

  2. Forest-savanna- morichal dynamics in relation to fire and human occupation in the southern Gran Sabana (SE Venezuela) during the last millennia

    NASA Astrophysics Data System (ADS)

    Montoya, Encarni; Rull, Valentí; Stansell, Nathan D.; Abbott, Mark B.; Nogué, Sandra; Bird, Broxton W.; Díaz, Wilmer A.

    2011-11-01

    The southern Gran Sabana (SE Venezuela) holds a particular type of neotropical savanna characterized by the local occurrence of morichales ( Mauritia palm swamps) , in a climate apparently more suitable for rain forests. We present a paleoecological analysis of the last millennia of Lake Chonita (4°39'N-61°0'W, 884 m elevation), based on biological and physico-chemical proxies. Savannas dominated the region during the last millennia, but a significant vegetation replacement occurred in recent times. The site was covered by a treeless savanna with nearby rainforests from 3640 to 2180 cal yr BP. Water levels were higher than today until about 2800 cal yr BP. Forests retreated since about 2180 cal yr BP onwards, likely influenced by a higher fire incidence that facilitated a dramatic expansion of morichales. The simultaneous appearance of charcoal particles and Mauritia pollen around 2000 cal yr BP supports the potential pyrophilous nature of this palm and the importance of fire for its recent expansion. The whole picture suggests human settlements similar to today - in which fire is an essential element - since around 2000 yr ago. Therefore, present-day southern Gran Sabana landscapes seem to have been the result of the synergy between biogeographical, climatic and anthropogenic factors, mostly fire.

  3. Association of Transferable Quinolone Resistance Determinant qnrB19 with Extended-Spectrum ?-Lactamases in Salmonella Give and Salmonella Heidelberg in Venezuela

    PubMed Central

    González, Fanny

    2013-01-01

    Four nontyphoidal Salmonella strains with resistance to extended-spectrum cephalosporins and nonclassical quinolone resistance phenotype were studied. Two S. Give were isolated from pediatric patients with acute gastroenteritis, and two S. Heidelberg were recovered from raw chicken meat. Phenotypic characterization included antimicrobial susceptibility testing and detection of extended-spectrum ?-lactamases (ESBLs) by the double-disc synergy method. The detection of quinolone resistance-determining regions (QRDR) of gyrA, gyrB, and gyrC genes, blaESBLs genes, and plasmid-mediated quinolone resistance (PMQR) determinants was carried out by molecular methods. Plasmid analysis included Southern blot and restriction patterns. Transferability of resistance genes was examined by transformation. blaTEM-1 + blaSHV-12 genes were detected in S. Give SG9611 and blaTEM-1 + blaCTX-M-2 in the other three strains: S. Give SG9811, S. Heidelberg SH7511, and SH7911. Regardless of origin and serovars, the qnrB19 gene was detected in the 4 strains studied. All determinants of resistance were localized in plasmids and successfully transferred by transformation. This study highlights the circulation of qnrB19 associated with blaTEM-1, blaSHV-12, and blaCTX-M-2 in S. Give and S. Heidelberg in Venezuela. The recognition of factors associated with increasing resistance and the study of the molecular mechanisms involved can lead to a more focused use of antimicrobial agents. PMID:24187555

  4. Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of Venezuela

    PubMed Central

    González-Pedraza, Ana Francisca; Dezzeo, Nelda

    2014-01-01

    We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen. PMID:25610907

  5. Sedimentary evolution of the upper Cretaceous and late Oligocene sequences, and its relation to oil production, North Monagas area, Eastern Venezuela

    SciTech Connect

    Sambrano, J.; Rojas, B.; Rendon, J.; Chigne, R.; Maguregui, J.

    1996-08-01

    The most important oil reservoirs of the Eastern Venezuela Basin are located in the North Monagas Area. These reservoirs are contained within a 3500 ft Cretaceous to Late Oligocene sedimentary section. Daily production is rated at about 350 MBO and 1000 MMCFG. At this moment, these reservoirs are undergoing special studies, in order to establish enhanced recovery projects, for which heterogeneity definition is very important. The database consisted of log analyses of 136 wells, sedimentological and biostratigraphic interpretation of 10,200 ft of cores, and biostratigraphic interpretation of ditch samples from 13 wells. Sedimentary models, based on facies analyses and deltaic conceptual models of 31 separate genetic units were defined. The models allowed for the interpretation of paleoenvironments, sedimentary facies architecture, direction of sedimentation and depocenters. The preferred sediment orientation was determined to be West-East. In the Santa Barbara and Pirital reservoirs the Late Oligocene sediments are composed of fluvial deposits, and the Cretaceous sediments of estuarine deposits. In the Carito-Mulata reservoirs, the Late Oligocene sediments are composed of fluvial to marine deposits, and the Upper Cretaceous sediments of estuarine deposits. Possible preferred transmissibility pathways for fluid injection were described, providing a great support for the enhanced recovery phases of these reservoirs.

  6. Overview of radiometric ages in three allochthonous belts of Northern Venezuela: Old ones, new ones, and their impact on regional geology

    USGS Publications Warehouse

    Sisson, V.B.; Ave Lallemant, H.G.; Ostos, M.; Blythe, A.E.; Snee, L.W.; Copeland, Peter; Wright, J.E.; Donelick, R.A.; Guth, L.R.

    2005-01-01

    The margin of northern Venezuela is a complex zone representing the orogenic events from basement formation to subsequent subduction and exhumation during transpressional collision. This boundary zone has six east-west-trending belts that each record a different segment of its development. This geologic complexity requires radiometric ages to unravel, and we herein provide 48 new ages including U-Pb (4), Rb-Sr (2), 40Ar/39Ar (24), zircon and apatite fission-track (17), and 14C (1) ages to constrain the evolution of three of these belts. These three belts are the Cordillera de la Costa, Caucagua-El Tinaco, and Serran??a del Interior belts. In the Cordillera de la Costa belt, U-Pb geochronologic data indicate portions of the basement igneous and metaigneous rocks formed in the Cambro-Ordovician (513-471 Ma). New 40Ar/39Ar data from Margarita Island indicate that some of the subduction complex was rapidly cooled and exhumed, whereas other portions indicate slower cooling. This contrasts with new 40Ar/39Ar data from the Puerto Cabello. ?? 2005 Geological Society of America.

  7. Rapid Climatic Change at the End of the Last Glacial as Determined from Palynological Analysis of Sediments from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Delusina, I.; Peterson, L. C.; Spero, H.

    2005-05-01

    We report the first palynological study of a deep marine sediment core from the anoxic Cariaco Basin, off the coast of Venezuela. The Cariaco Basin acts as a natural sediment trap for rapidly accumulating sediments of marine and terrestrial origin. This situation creates favorable conditions for studying short-term paleoenvironmental change. Our pollen analyses indicate unique pollen assemblages which mirror the complex altitudinal zonation of coastal vegetation and its dynamics. The pollen analyses encompass the interval from 3 to 9 m in core MD03-2620, spanning the Glacial/Holocene transition and including the Younger Dryas and the beginning of the Preboreal. Our data indicate large changes during the time of Heinrich event 1 (ca 16-14 Kyr BP) with high arboreal/nonarboreal pollen ratios (2/8) and a dominance of wormwood changing to a cereals/sedge community. Another characteristic of this interval is the lowest pollen concentration, indicating the coldest and driest observed conditions. The disappearance of mangrove pollen at the time of the coldest episodes provides additional indirect evidence for the deterioration of climate conditions and for a drop in sea level. Maximum forest vegetation is found from the middle of the Bolling/Allerod and the middle of the Younger Dryas. This is followed by a similar, though less intense, interval of cooling between the Younger Dryas and the Preboreal. Variations in both the diversity of species and the pollen concentration correlate well with changes in sediment color and with the marine oxygen isotope record.

  8. Como EURAXESS pode ajuda-lo? Charlotte Grawitz, EURAXESS Links Brazil

    E-print Network

    Hanazaki, Natalia

    Como EURAXESS pode ajuda-lo? Charlotte Grawitz, EURAXESS Links Brazil Florianópolis, 17 de novembro Links Brazil - Como Trabalhamos Website e Facebook Newsletter e Publicações Apresentações e Eventos #12;Website (brazil.euraxess.org), Newsletter & Inscrição #12;Eventos EURAXESS Links Brazil EURAXESS Share

  9. K.K. Gan Como05 1 The Ohio State University

    E-print Network

    Gan, K. K.

    Pixel Detector #12;K.K. Gan Como05 2 Outline Introduction Proton Irradiation Studies Production Status Summary #12;K.K. Gan Como05 3 ATLAS Pixel Detector Inner most tracking detector Pixel size: 50O vendor: 1st prototype: 1-2 SMD detached from few boards remove gold under SMD pads 2nd prototype: SMD

  10. Corrector de gramtica para estudiantes autodidactas de ingls como lengua extranjera

    E-print Network

    Martin, Ralph R.

    funcionamiento de un nuevo tipo de corrector grama- tical (el Corrector Gramatical de la UNED),que se fundamenta este corrector gramatical, que incluyera expresiones regulares, podría aplicarse en muchos más casos COMO LENGUA EXTRANJERA 1172 Palabras clave: corrector gramatical, ILE, español como lengua materna

  11. 78 FR 38287 - Bitterroot National Forest, Darby Ranger District, Como Forest Health Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    .... Correction In the Federal Register of June 17, 2013, in FR DOC 2013- 14229 on page 36163 in the second column... Forest Service Bitterroot National Forest, Darby Ranger District, Como Forest Health Project AGENCY...,640 acres of national forest between Lake Como and Lost Horse roads, about 6 miles northwest of...

  12. Community-randomized trial of lambdacyhalothrin-treated hammock nets for malaria control in Yanomami communities in the Amazon region of Venezuela.

    PubMed

    Magris, M; Rubio-Palis, Y; Alexander, N; Ruiz, B; Galván, N; Frias, D; Blanco, M; Lines, J

    2007-03-01

    We conducted a community-randomized controlled trial in an area of moderate malaria transmission in the Amazon region, southern Venezuela, home of the Yanomami indigenous ethnic group. The aim was to compare the malaria incidence rate in villages with lambdacyhalothrin-treated hammock nets (ITHN) or with placebo-treated hammock nets (PTHN). In both arms of the study, intensive surveillance for early case detection was maintained and prompt malaria treatment was administered. Baseline data were collected before the intervention and a population of around 924 Yanomami was followed for 2 years. Despite the recent introduction of nets in the Yanomami villages and the adverse natural conditions in the area, the nets were accepted enthusiastically by the study population, used conscientiously and looked after carefully. The malaria incidence rate per thousand person-years at risk was 114.6 in the IHTN group and 186.8 in the PTHN group. The adjusted rate ratios indicated that ITHN prevent 56% [IRR: 0.44, 95% confidence interval (CI): 52-59%] of new malaria cases. ITHN reduced the prevalence of parasitaemia by 83% [relative risks (RR): 0.17, 95% CI: 47-100%], according to a cross-sectional survey carried out during the high transmission season. The prevalence of splenomegaly and anaemia was too low to detect any possible reduction as a result of ITHN. The main conclusion of the present study is that ITHN can reduce malaria incidence in the area and it is the most feasible method for malaria control in a forested area where indigenous villages are scattered over a large territory. This is the first community-level epidemiological trial to show that ITHN are highly effective against malaria transmitted by Anopheles darlingi. PMID:17313511

  13. Mixed domestic infestation by Rhodnius prolixus Stal, 1859 and Panstrongylus geniculatus Latreille, 1811, vector incrimination, and seroprevalence for Trypanosoma cruzi among inhabitants in El Guamito, Lara State, Venezuela.

    PubMed

    Feliciangeli, M Dora; Carrasco, Hernán; Patterson, James S; Suarez, Benny; Martínez, Clara; Medina, Mehudy

    2004-10-01

    Mixed infestation of nymphs and adults of Rhodnius prolixus Stal, 1859 and Panstrongylus geniculatus Latreille, 1811 was detected in 3 (15%) of 20 dwellings in El Guamito, an endemic focus of Chagas disease in Lara State, Venezuela. In one of the houses, both species were positive for Trypanosoma cruzi: 14.3% (R. prolixus) and 20% (P. geniculatus ). The overall infection rate in 143 of 352 R. prolixus was 16.1%. Parasites isolated from R. prolixus were identified as T. cruzi I by random amplified polymorphic DNA analysis. Dot-enzyme-linked immunosorbent assays of 36 R. prolixus showed that 58.3% of the R. prolixus had fed on humans. The gut contents of one fifth-instar nymph of P. geniculatus that was positive for T. cruzi also reacted with anti-human serum. A questionnaire was used to gather data on the demographic and socioeconomic characteristics of the population. An indirect immunofluorescent test, an indirect hemaglutination test, and an ELISA were used to detect the presence of antibodies against T. cruzi in 84 of 86 inhabitants and in 15.5% of people more than 20 years old. The relative risk (RR) of infection was greater in men than in women (RR = 1.61, 95% confidence interval = 0.54-4.80). Of the people more than 15 years old, 36.6% had no formal education. All respondents recognized triatomine bugs, but they did not relate them to Chagas disease transmission. A total of 85.7% of the houses were "ranchos" suitable for the colonization of triatomine bugs. The possible domiciliation of P. geniculatus and the implications of competition with R. prolixus for resources are discussed. Since there is no clear separation of food sources, abiotic factors such as microclimatic variation within houses may be critical to predict the outcome of the process of competition and potential domestication of this generally sylvatic species. PMID:15516649

  14. Light and desiccation responses of some Hymenophyllaceae (filmy ferns) from Trinidad, Venezuela and New Zealand: poikilohydry in a light-limited but low evaporation ecological niche

    PubMed Central

    Proctor, Michael C. F.

    2012-01-01

    Background and Aims Hymenophyllaceae (filmy ferns) are typically plants of shady, constantly moist habitats. They attain greatest species diversity and biomass in humid tropical montane forests and temperate hyperoceanic climates. This paper presents ecophysiological data bearing on their worldwide ecological niche space and its limits. Methods Chlorophyll fluorescence was used to monitor recovery in desiccation experiments, and for measurements of 95 % saturating irradiance [photosynthetic photon flux density (PPFD95 %)] of photosynthetic electron flow and other parameters, in the New Zealand Hymenophyllum sanguinolentum, and three species each of Hymenophyllum and Trichomanes from forests in Trinidad and Venezuela. Key Results Hymenophyllum sanguinolentum was comparable in desiccation tolerance and light responses with the European species. The more common species in the two tropical forests showed PPFD95 % >100 µmol m?2 s?1, and withstood moderate desiccation (–40 MPa) for several days. The four most shade-adapted species had PPFD95 % ?51 µmol m?2 s?1, and were sensitive to even mild and brief desiccation (–22 MPa for 3 d). Conclusions Light and desiccation responses of filmy ferns can be seen as an integrated package. At low light and windspeed in humid forests, net radiation and saturation deficit are low, and diffusion resistance high. Water loss is slow and can be supported by modest conduction from the sub-stratum. With higher irradiance, selection pressure for desiccation tolerance increases progressively. With low light and high humidity, the filmy fern pattern of adaptation is probably optimal, and the vascular plant leaf with mesophyll and stomata offers no advantage in light capture, water economy or CO2 uptake. Trade-offs between light adaptation and desiccation tolerance, and between stem conduction and water absorption through the leaf surface, underlie adaptive radiation and niche differentiation of species within the family. Hymenophyllaceae are a rare example of an evolutionary shift of adaptive strategy from typical vascular plant adaptation to the poikilohydry most typical of bryophytes. PMID:22334496

  15. Export of dissolved organic and inorganic nitrogen and total suspended sediments across an urbanization gradient in four tropical rivers of Venezuela

    NASA Astrophysics Data System (ADS)

    Rasse, R. J.; Perez, T.; Giuliante, A.; Donoso, L.

    2012-12-01

    We determined monthly concentrations of total dissolved nitrogen (TDN), dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON) and total suspended sediment (TSS) from 4 Venezuelan watersheds from August 2008 to September 2009. Three of these watersheds are mountainous rivers (Tuy, Neverí and Manzanares) and one is flat (Unare River). The three mountainous rivers vary in the degree of urbanization, with the Tuy hosting Caracas, the largest city in Venezuela. We found an order of magnitude larger TDN concentrations in the Tuy, which is impacted mainly by untreated point sources derived from Caracas metropolitan area. The largest TSS values were observed in the three mountainous rivers (Tuy, Neveri and Manzanares). TDN and TSS concentrations varied seasonally with larger TDN and lower TSS values during the dry season for all rivers. Most of the annual discharge of TDN (92%) and TSS (97%) takes place during the rainy season. Our results suggest that urbanization is the largest contributor affecting the composition and magnitude of TDN, whereas orography and local hydrology control the discharge of both TSS and TDN. We calculated the Water Pollution Level (WPL) for DIN and DON to determine the degree of contamination of these species in the evaluated watersheds. WPL values less than 1 indicate that there is in average enough dilution capacity in the river to assimilate the pollutant, whereas WPL larger than 1 indicate that the pollution assimilation capacity has been surpassed. All our evaluated rivers but the Tuy River show WPL-DIN and WPL-DON values between 0.1 and 0.96. The Tuy River had a WPL-DIN=6.3 and WPL-DON= 7.5. We attribute the Tuy River's large DIN and DON contamination to untreated urban point sources due to the strong correlation between population density and DIN and DON concentration from the evaluated watersheds. Our results suggest that urgent water treatment is required for this watershed to diminish the impact in coastal ecosystems.

  16. Triatoma maculata, the Vector of Trypanosoma cruzi, in Venezuela. Phenotypic and Genotypic Variability as Potential Indicator of Vector Displacement into the Domestic Habitat

    PubMed Central

    García-Alzate, Roberto; Lozano-Arias, Daisy; Reyes-Lugo, Rafael Matías; Morocoima, Antonio; Herrera, Leidi; Mendoza-León, Alexis

    2014-01-01

    Triatoma maculata is a wild vector of Trypanosoma cruzi, the causative agent of Chagas disease; its incursion in the domestic habitat is scant. In order to establish the possible domestic habitat of T. maculata, we evaluated wing variability and polymorphism of genotypic markers in subpopulations of T. maculata that live in different habitats in Venezuela. As markers, we used the mtCyt b gene, previously apply to evaluate population genetic structure in triatomine species, and the ?-tubulin gene region, a marker employed to study genetic variability in Leishmania subgenera. Adults of T. maculata were captured in the period 2012–2013 at domestic, peridomestic (PD), and wild areas of towns in the Venezuelan states of Anzoátegui, Bolívar, Portuguesa, Monagas, Nueva Esparta, and Sucre. The phenotypic analysis was conducted through the determination of the isometric size and conformation of the left wing of each insect (492 individuals), using the MorphoJ program. Results reveal that insects of the domestic habitat showed significant reductions in wing size and variations in anatomical characteristics associated with flying, in relation to the PD and wild habitats. The largest variability was found in Anzoátegui and Monagas. The genotypic variability was assessed by in silico sequence comparison of the molecular markers and PCR-RFLP assays, demonstrating a marked polymorphism for the markers in insects of the domestic habitat in comparison with the other habitats. The highest polymorphism was found for the ?-tubulin marker with enzymes BamHI and KpnI. Additionally, the infection rate by T. cruzi was higher in Monagas and Sucre (26.8 and 37.0%, respectively), while in domestic habitats the infestation rate was highest in Anzoátegui (22.3%). Results suggest domestic habitat colonization by T. maculata that in epidemiological terms, coupled with the presence in this habitat of nymphs of the vector, represents a high risk of transmission of Chagas disease. PMID:25325053

  17. Planktonic foraminiferal shell weight and boron isotopic composition as proxies for carbonate system parameters: Insight from sediment trap studies in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Marshall, B. J.; Thunell, R.; Henehan, M. J.; McConnell, M. C.; Astor, Y.

    2012-12-01

    The area-normalized shell weight (ANSW) and boron isotopic compositions of planktonic foraminifera collected from Cariaco Basin, Venezuela sediment traps were used as proxies for seawater carbonate ion concentrations ([CO32-]) and pH respectively. Three species of planktonic forams: G. ruber (pink), G. sacculifer, and O. universa were used in conjunction with known hydrographic data to calibrate the relationship between carbonate ion concentration and area-normalized shell weight. Individuals of each species were picked from sediment trap samples collected between January 2005 and September 2008, then weighed and photographed for size analysis. The individual foraminiferal ANSW were averaged for each sample (n > 10) and compared to the concurrent [CO32-] calculated from time-equivalent hydrographic data (pH, alkalinity, temperature, salinity, nutrient concentrations). The results of this study revealed strong positive-linear relationships between [CO32-] and the ANSW of G. ruber (r2 = 0.84), G. sacculifer (r2 = 0.90), and O. universa (r2 = 0.52) for broad size fractions. The results also suggest that the relationship between [CO32-] and ANSW is variable amongst species and thus species-specific equations are necessary when using foraminiferal ANSW during down-core paleo-oceanographic reconstructions. The relationship between pH and the boron isotopic composition of sediment trap foraminiferal calcite was also assessed. Trap samples containing 3-5 mg of O. universa were prepared for boron isotopic analysis on the Neptune MC-ICP-MS using a micro-sublimation method following oxidative cleaning and dissolution via nitric acid. The results of these sediment trap calibration studies were then compared to previously published calibration equations. The determination of seawater [CO32-] and pH using the proxies above will allow for the derivation of all other carbonate parameters during down-core paleo-climatic and paleo-oceanographic studies.

  18. Trends of violence among 7th, 8th and 9th grade students in the state of Lara, Venezuela: The Global School Health Survey 2004 and 2008

    PubMed Central

    2011-01-01

    Background Violence by young people is one of the most visible forms of violence and contributes greatly to the global burden of premature death, injury and disability. Methods The Global School-based Student Health Survey (GSHS), State of Lara, Venezuela (GSHS-Lara) is a school-based surveillance system. It comprises a repeated, cross-sectional, self-administered survey drawn from a representative sample of 7th to 9th grade students, performed in the school years 2003-2004 (GSHS-Lara 2004) and 2007-2008 (GSHS-Lara 2008). It explores, among other things, a general violence indicator such as school absenteeism due to feeling unsafe at school or on the way to or from school for any reason; and more specific indicators of violence such as robbery, bullying, physical fights and use of weapons, as well as exposure to lectures on how to prevent violence. Results are given in terms of prevalence percentage. Results Absenteeism doubled between the two study periods (10.8% to 20.8%). The number of students that were a victim of robbery remained high and without change both outside (14.2% and 14.8%) and inside school (21.7% and 22.0%). The number of victims of bullying was high and increasing (33.4% and 43.6%). Bullying associated with being physically attacked decreased (18.5% to 14.3%). Physical attacks without active participation and not associated with bullying were frequent (21.5%). Physical fighting with active participation prevalence remained high and without change (27.5% and 28.2%). Carrying a weapon almost doubled (4.3% to 7.1%). Less than 65% reported classes for violence prevention. Conclusions The GSHS-Lara shows that violence is an important public health problem that needs to be addressed by the community and its authorities. PMID:22958602

  19. Geochemistry of surface and subsurface waters in quartz-sandstones: significance for the geomorphic evolution of tepui table mountains (Gran Sabana, Venezuela)

    NASA Astrophysics Data System (ADS)

    Mecchia, Marco; Sauro, Francesco; Piccini, Leonardo; De Waele, Jo; Sanna, Laura; Tisato, Nicola; Lira, Jesus; Vergara, Freddy

    2014-04-01

    In situ measurements of discharge, pH, electric conductivity (EC), temperature, and SiO2 content have been carried out during five expeditions in the last 20 years on the summit plateaus, inside caves and along the rivers of the surrounding lowlands of three tepui massifs in Venezuela (Auyan, Roraima, and Chimanta). Additionally, detailed chemical analyses were performed on waters sampled in a newly discovered extensive quartz-sandstone cave system on the Auyan Tepui. Rock samples of the quartz-sandstone bedrock from different locations have been analysed to obtain their chemical composition with a wavelength dispersive X-ray fluorescence spectrometer. These data show that the majority of silica present in surface and subsurface water comes from dissolution of quartz and only in minor amount from hydrolysis of other silicate minerals. Probably the presence of a hardened crust of iron hydroxides limits the dissolution of silica on the top surface of tepuis. Dissolution in the subsurface, instead, is more significant and causes, in the long term, the “arenisation” of the quartz-sandstone and its subsequent removal by mechanical erosion. On the other hand, waters flowing on the arkosic rock outcropping on the lowland below the tepuis obtain their high dissolved silica content mainly from hydrolysis of silicates. The morphological evolution of these table mountains appears thus to be controlled mainly by the underground weathering of the quartz-sandstone, with the opening of deep fractures (grietas) and the collapse of large underground horizontal cave systems. Scarp retreat, instead, seems to be related to the higher weathering rate of the more arkosic formations underlying the quartz-sandstones.

  20. Field evaluation of four novel enzyme immunoassays for Chagas' disease in Venezuela blood banks: comparison of assays using fixed-epimastigotes, fixed-trypomastigotes or trypomastigote excreted-secreted antigens from two Trypanosoma cruzi strains.

    PubMed

    Berrizbeitia, M; Ndao, M; Bubis, J; Gottschalk, M; Aché, A; Lacouture, S; Medina, M; Ward, B J

    2006-12-01

    Many serological tests have been developed for the diagnosis of Chagas' disease, but few have been subjected to a rigorous field evaluation. We have recently described several novel enzyme immunoassays (EIAs) based on fixed-whole organisms or trypomastigote excretory-secretory antigens (TESA) from different Trypanosoma cruzi strains (Tulahuen or Brazil). This study evaluated the most promising of these novel assays (e.g. fixed-epimastigotes, fixed-trypomastigotes, TESA Brazil and TESA Tulahuen antigens) in a field study of Venezuelan blood bank specimens. The assays were tested in an operator-blinded fashion using 2038 blood bank samples obtained from low and high T.cruzi prevalence regions of Venezuela (n= 1050 and n= 988 from Bolivar and Portuguesa states, respectively). Based on National Laboratory for Chagas Immunodiagnosis (NLCI) 'gold standard' results, all novel EIAs were superior to the commercial kit currently used in Venezuela, achieving 100% sensitivity and >99% specificity at optimal cut-off values. The novel assays identified seven false-negative samples compared with the routine screening performed by the Venezuelan blood bank although two samples were also misclassified as positive. Minor differences in the performance of the four novel assays were observed at lower arbitrary cut-off values. This study confirms the potential utility of both the fixed-organism and the TESA-based assays in the diagnosis of T.cruzi infection. PMID:17163873

  1. High prevalence of asthma symptoms in Warao Amerindian children in Venezuela is significantly associated with open-fire cooking: a cross-sectional observational study

    PubMed Central

    2013-01-01

    Background The International Study on Asthma and Allergies in Childhood (ISAAC) reported a prevalence of asthma symptoms in 17 centers in nine Latin American countries that was similar to prevalence rates reported in non-tropical countries. It has been proposed that the continuous exposure to infectious diseases in rural populations residing in tropical areas leads to a relatively low prevalence of asthma symptoms. As almost a quarter of Latin American people live in rural tropical areas, the encountered high prevalence of asthma symptoms is remarkable. Wood smoke exposure and environmental tobacco smoke have been identified as possible risk factors for having asthma symptoms. Methods We performed a cross-sectional observational study from June 1, 2012 to September 30, 2012 in which we interviewed parents and guardians of Warao Amerindian children from Venezuela. Asthma symptoms were defined according to the ISAAC definition as self-reported wheezing in the last 12 months. The associations between wood smoke exposure and environmental tobacco smoke and the prevalence of asthma symptoms were calculated by means of univariate and multivariable logistic regression analyses. Results We included 630 children between two and ten years of age. Asthma symptoms were recorded in 164 of these children (26%). The prevalence of asthma symptoms was associated with the cooking method. Children exposed to the smoke produced by cooking on open wood fires were at higher risk of having asthma symptoms compared to children exposed to cooking with gas (AOR 2.12, 95% CI 1.18 - 3.84). Four percent of the children lived in a household where more than ten cigarettes were smoked per day and they had a higher risk of having asthma symptoms compared to children who were not exposed to cigarette smoke (AOR 2.69, 95% CI 1.11 - 6.48). Conclusion Our findings suggest that children living in rural settings in a household where wood is used for cooking or where more than ten cigarettes are smoked daily have a higher risk of having asthma symptoms. PMID:23870058

  2. Varying results using the shell weights of different planktonic foraminiferal species as a proxy for changing carbonate ion concentrations in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Marshall, B. J.; McConnell, M. C.; Thunell, R.; Astor, Y.

    2011-12-01

    Ocean acidification, due in part to increased atmospheric CO2, is thought to reduce calcification rates of planktonic foraminifera. A positive linear relationship has been found between foraminiferal shell weight and the carbonate ion concentrations [CO32-] of the waters in which they calcify (Barker and Elderfield, 2002). Such a relationship provides a useful proxy for determining past changes in ocean carbonate chemistry. The Cariaco Basin, Venezuela (10°30' N, 65°31 W) is an ideal study area to determine the relationship between seawater [CO32-] and planktonic foraminiferal shell weight as the region is characterized by the seasonal upwelling of low pH, low temperature, and low carbonate ion concentrated waters. In this study we use biweekly sediment trap samples and concurrent hydrographic measurements collected between January 2005 and May 2010 in the Cariaco Basin to assess the relationship between [CO32-] and shell weight of three planktonic foraminiferal species, Globigerinoides ruber, Orbulina universa and Globigerinoides sacculifer. Measured salinity, pH, sea surface temperature (SST) and total alkalinity (TA) were used to estimate pCO2 and [CO32-]. Size-normalized shells of G. ruber, O. universa and G. sacculifer were picked (> 10 per sample), photographed for size analysis and weighed. Globigerinoides ruber shell weights varied from 10.4 ?g to 17.7 ?g, with an average weight of 14.62 ?g from 2005 to 2007, with concurrent surface water [CO32-] ranging from ~220-280 ?mol/kg. Orbulina universa shell weights ranged from 35.4 ?g to 67.8 ?g with an average shell weight of 50.1 ?g. Preliminary data reveal a strong positive linear relationship between foraminiferal shell weight and [CO32-] for G. ruber (R2 = 0.52, 99% confidence level; p = 0.007) but no significant relationship for O. universa (R2 = 0.05, ; p = 0.4). The initial results suggest that the foraminiferal shell weight changes of certain planktonic foraminiferal species may reflect changes in the carbonate system better than others.

  3. Effective control of dengue vectors with curtains and water container covers treated with insecticide in Mexico and Venezuela: cluster randomised trials

    PubMed Central

    Kroeger, Axel; Lenhart, Audrey; Ochoa, Manuel; Villegas, Elci; Levy, Michael; Alexander, Neal; McCall, P J

    2006-01-01

    Objectives To measure the impact on the dengue vector population (Aedes aegypti) and disease transmission of window curtains and water container covers treated with insecticide. Design Cluster randomised controlled trial based on entomological surveys and, for Trujillo only, serological survey. In addition, each site had a non-randomised external control. Setting 18 urban sectors in Veracruz (Mexico) and 18 in Trujillo (Venezuela). Participants 4743 inhabitants (1095 houses) in Veracruz and 5306 inhabitants (1122 houses) in Trujillo. Intervention Sectors were paired according to entomological indices, and one sector in each pair was randomly allocated to receive treatment. In Veracruz, the intervention comprised curtains treated with lambdacyhalothrin and water treatment with pyriproxyfen chips (an insect growth regulator). In Trujillo, the intervention comprised curtains treated with longlasting deltamethrin (PermaNet) plus water jar covers of the same material. Follow-up surveys were conducted at intervals, with the final survey after 12 months in Veracruz and nine months in Trujillo. Main outcome measures Reduction in entomological indices, specifically the Breteau and house indices. Results In both study sites, indices at the end of the trial were significantly lower than those at baseline, though with no significant differences between control and intervention arms. The mean Breteau index dropped from 60% (intervention clusters) and 113% (control) to 7% (intervention) and 12% (control) in Veracruz and from 38% to 11% (intervention) and from 34% to 17% (control) in Trujillo. The pupae per person and container indices showed similar patterns. In contrast, in nearby communities not in the trial the entomological indices followed the rainfall pattern. The intervention reduced mosquito populations in neighbouring control clusters (spill-over effect); and houses closer to treated houses were less likely to have infestations than those further away. This created a community effect whereby mosquito numbers were reduced throughout the study site. The observed effects were probably associated with the use of materials treated with insecticide at both sites because in Veracruz, people did not accept and use the pyriproxyfen chips. Conclusion Window curtains and domestic water container covers treated with insecticide can reduce densities of dengue vectors to low levels and potentially affect dengue transmission. PMID:16735334

  4. New vanadium compounds in Venezuela heavy crude oil detected by positive-ion electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Zhao, Xu; Shi, Quan; Gray, Murray R; Xu, Chunming

    2014-01-01

    Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of C(n)H(2n-40)N(4)V(1)O(1) (36 ? n ? 58),C(n)H(2n-42)N(4)V(1)O(1) (37 ? n ? 57),C(n)H(2n-44)N(4)V(1)O(1) (38 ? n ? 59),C(n)H(2n-46)N(4)V(1)O(1) (43 ? n ? 54),C(n)H(2n-48)N(4)V(1)O(1) (45 ? n ? 55),C(n)H(2n-38)N(4)V(1)S(1)O(1) (36 ? n ? 41),C(n)H(2n-40)N(4)V(1)S(1)O(1) (35 ? n ? 51),C(n)H(2n-42)N(4)V(1)S(1)O(1) (36 ? n ? 54),C(n)H(2n-44)N(4)V(1)S(1)O(1) (41 ? n ? 55),C(n)H(2n-46)N(4)V(1)S(1)O(1) (39 ? n ? 55),C(n)H(2n-27)N(5)V(1)O(1) (29 ? n ? 40),C(n)H(2n-29)N(5)V(1)O(1) (34 ? n ? 42),C(n)H(2n-33)N(5)V(1)O(1) (31 ? n ? 38),C(n)H(2n-35)N(5)V(1)O(1) (32 ? n ? 41),C(n)H(2n-27)N(5)V(1)O(2) (32 ? n ? 41) and C(n)H(2n-29)N(5)V(1)O(2) (33 ? n ? 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils. PMID:24948028

  5. New Vanadium Compounds in Venezuela Heavy Crude Oil Detected by Positive-ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    PubMed Central

    Zhao, Xu; Shi, Quan; Gray, Murray R.; Xu, Chunming

    2014-01-01

    Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of CnH2n-40N4V1O1 (36 ? n ? 58),CnH2n-42N4V1O1 (37 ? n ? 57),CnH2n-44N4V1O1 (38 ? n ? 59),CnH2n-46N4V1O1 (43 ? n ? 54),CnH2n-48N4V1O1 (45 ? n ? 55),CnH2n-38N4V1S1O1 (36 ? n ? 41),CnH2n-40N4V1S1O1 (35 ? n ? 51),CnH2n-42N4V1S1O1 (36 ? n ? 54),CnH2n-44N4V1S1O1 (41 ? n ? 55),CnH2n-46N4V1S1O1 (39 ? n ? 55),CnH2n-27N5V1O1 (29 ? n ? 40),CnH2n-29N5V1O1 (34 ? n ? 42),CnH2n-33N5V1O1 (31 ? n ? 38),CnH2n-35N5V1O1 (32 ? n ? 41),CnH2n-27N5V1O2 (32 ? n ? 41) and CnH2n-29N5V1O2 (33 ? n ? 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils. PMID:24948028

  6. A High-Resolution Stalagmite Holocene Paleoclimate Record from Northern Venezuela with Insights into the Timing and Duration of the 8.2 ka Event

    NASA Astrophysics Data System (ADS)

    Retrum, J. B.; Gonzalez, L. A.; Edwards, R.; Cheng, H.; Tincher, S. M.; Urbani, F.

    2013-12-01

    The dearth of studies and data in the tropics hinders our understanding of atmospheric and oceanic interactions between the low latitudes and the rest of the globe. To understand better the interactions, specifically between the Caribbean and the North Atlantic, three stalagmites were collected from Cueva Zarraga in the Falcón Mountains of northwestern Venezuela and analyzed to determine local paleoclimatic history. Stalagmites ages were determined by U/Th disequilibrium and show a nearly complete Holocene record. The stalagmites have an average temporal resolution of 10.8 years/mm and ranges from 2.1 to 62.7 years. Both the carbon and oxygen isotope records preserve quasi-millennial oscillations and show a major depletion shift from the last glacial period into the Holocene, suggesting warmer and wetter conditions during the Holocene. The preservation of quasi-millennial oscillations and of high frequency multi-decadal changes by the ?13C indicates that the soil-vegetation-stalagmite system is acting as an amplifier of the climatic signal produced by climatic events and changes. In the early Holocene, the ?18O record shows a depletion trend from ~ 11,000 to 8,000 cal yr BP before reaching the Holocene Thermal Maximum. A prominent ?18O enrichment event is recorded in all the stalagmites that correspond to the 8.2 ka event. The 8.2 ka event is represented by a double peak with duration of ~ 180 years. Other short-term ?18O enrichment events likely correspond to Bond events 1, 2, 5, and 6. The late Holocene record, like other Caribbean records, indicates that the climate system diverges from insolation and may represent an atmospheric rearrangement that resulted in ENSO increase instability or in reduced seasonal movement of the Inter-Tropical Convergence Zone (ITCZ). Today, Cueva Zarraga is at the northern extent of the ITCZ and has two rainy seasons. The ?18O enrichment events during the Holocene suggest drier conditions southern displacement of the ITCZ, also suggested by Brazilian speleothem records that show trends that anti-correlate with Cueva Zarraga. The Cariaco Basin and Cueva Zarraga records show similar trends. The close proximity of Cueva Zarraga to Cariaco Basin may allow for a high-resolution tropical terrestrial and oceanic climatic response comparison.

  7. New Vanadium Compounds in Venezuela Heavy Crude Oil Detected by Positive-ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Zhao, Xu; Shi, Quan; Gray, Murray R.; Xu, Chunming

    2014-06-01

    Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of CnH2n-40N4V1O1 (36 <= n <= 58),CnH2n-42N4V1O1 (37 <= n <= 57),CnH2n-44N4V1O1 (38 <= n <= 59),CnH2n-46N4V1O1 (43 <= n <= 54),CnH2n-48N4V1O1 (45 <= n <= 55),CnH2n-38N4V1S1O1 (36 <= n <= 41),CnH2n-40N4V1S1O1 (35 <= n <= 51),CnH2n-42N4V1S1O1 (36 <= n <= 54),CnH2n-44N4V1S1O1 (41 <= n <= 55),CnH2n-46N4V1S1O1 (39 <= n <= 55),CnH2n-27N5V1O1 (29 <= n <= 40),CnH2n-29N5V1O1 (34 <= n <= 42),CnH2n-33N5V1O1 (31 <= n <= 38),CnH2n-35N5V1O1 (32 <= n <= 41),CnH2n-27N5V1O2 (32 <= n <= 41) and CnH2n-29N5V1O2 (33 <= n <= 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils.

  8. Nuestro inters como Facultad de Ciencias de la Salud es formar a la poblacin general y a determinados sectores profesionales para salvar vidas. La formacin se

    E-print Network

    Escolano, Francisco

    de PCR y la importancia del factor tiempo. Analizar correctamente una situación de emergencia y cuando alertar a los dispositivos de emergencias. Saber desarrollar las maniobras de RCP básica en Profesorado: acreditado por la American Hearts Association (AHA) y por la Sociedad Española de Medicina de

  9. K.K. Gan COMO07 1 Study of the Radiation Hardness of

    E-print Network

    Gan, K. K.

    K.K. Gan COMO07 1 Study of the Radiation Hardness of VCSEL and PIN Arrays Oct 10, 2007 W. Fernando Outline Introduction Radiation hardness of VCSEL arrays Radiation hardness of PIN arrays Summary #12;K planned for Super-LHC in 2015 study radiation-hardness of VCSEL and PIN arrays for the opto-link upgrades

  10. CURSO DE INICIACIN A LA ENSEANZA DEL ESPAOL COMO LENGUA EXTRANJERA-FORMACIN DE PROFESORADO

    E-print Network

    CURSO DE INICIACIÓN A LA ENSEÑANZA DEL ESPAÑOL COMO LENGUA EXTRANJERA-FORMACIÓN DE PROFESORADO, diplomatura o grado)*: o En curso (especificar curso y carrera)*: Otros: *Será necesario acreditar los estudios en curso. FORMALIZACIÓN DE LA MATRÍCULA Para formalizar la matrícula del curso es necesario

  11. CURSO DE INICIACIN A LA ENSEANZA DEL ESPAOL COMO LENGUA EXTRANJERA-FORMACIN DE PROFESORADO

    E-print Network

    Verschure, Paul

    CURSO DE INICIACIÓN A LA ENSEÑANZA DEL ESPAÑOL COMO LENGUA EXTRANJERA-FORMACIÓN DE PROFESORADO o grado)*: En curso (especificar curso y carrera)*: Otros: *Será necesario acreditar los estudios matrícula de los estudios en curso. FORMALIZACIÓN DE LA MATRÍCULA Para formalizar la matrícula del curso es

  12. Novas estratgias comunicativas como fator de qualidade na interao de surdos em um sistema organizacional

    E-print Network

    Barbosa, Alberto

    122 Novas estratégias comunicativas como fator de qualidade na interação de surdos em um sistema formulário web e verificar se o uso de novas estratégias comunicativas melhora a interação dos surdos. Foram (MAC), uma com a interface original do sistema, e outra com o uso de novas estratégias comunicativas

  13. UNIVERSIDAD SIMON BOLIVAR SEDE DEL LITORAL

    E-print Network

    Vásquez, Carlos

    , Francia, Venezuela. 4.4.Caso de Venezuela: Marco legal. 4.5.Calidad de los servicios: concepto de calidad.7.Formación de personal ­ caso de Venezuela. La gestión de personal como elemento estratégico. La formación de, 1995 4.- Victor Calzadilla, Josefina Bruni Celi, Educación Técnica Media en Venezuela, Ediciones IESA

  14. Biology Curriculum Reform in Venezuela.

    ERIC Educational Resources Information Center

    Rondon, Leonor Mariasole

    2001-01-01

    Describes science in the Venezuelan school system which reflects on the process of development followed to design and validate the Biology Study Programs (BSP) with the emphasis on the relevance of curricular changes proposed in biological science for secondary education. (Contains 19 references.) (ASK)

  15. O processo de aquisição das vogais semi-abertas "é, ó" / ?, ? / do portugues (brasileiro) como lingua estrangeira

    E-print Network

    Simoes, Antonio Roberto Monteiro; Kelm, Orlando R.

    1991-09-01

    - guindo as linhas do livro Com licenga! (Simoes 1991), ou seja, por razoes praticas, evita separar o grupo latino como se explica no protocolo experimental. Dois trabalhos que podem ser considerados pioneiros nesta area sao aqueles de Ellison et al... pode ver no manual de orientagao que acompanha o livro. O trabalho experimental dos Professores Lombello e Baleeiro (1983) da Uni- versidade Estadual de Campinas—Unicamp, assim como o trabalho nas escolas secundarias do Texas como aqueles das...

  16. Alejarse como proceso social: niños y ancianos «abandonados» en Ayacucho1

    PubMed Central

    Leinaweaver, Jessaca

    2013-01-01

    En investigaciones previas sobre el acogimiento familiar y la adopción en Ayacucho, se ha podido descubrir cómo los ayacuchanos adquieren y producen relaciones sociales. Mientras negocian creativamente los discursos y espacios construidos simultáneamente por instituciones, comunidades, y estructuras sociales, van adquiriendo nuevas formas de relacionarse. Este artículo discute el proceso opuesto: el deshacerse de relaciones de parentesco, y el proceso social del abandono o alejamiento. Cuando se aleja a una persona de su familia o su comunidad, los que se quedan en ella llegan a entenderse como ciertos tipos de personas. En los estudios de caso discutidos aquí, recopilados a través de una detallada y cuidadosa observación participante y de entrevistas etnográficas grabadas entre 2001 y 2007, se puede ver cómo, después de un alejamiento social, los individuos que alejan se reinterpretan como sujetos que se encuentran superándose o volviéndose modernos, o bien sacrificándose. PMID:25177044

  17. Como os Alunos do Ensino Médio da Rede Estadual de São Paulo obtém Conhecimentos Astronômicos?

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2005-08-01

    Atualmente vivencia-se um mundo globalizado onde os computadores e a internet permitiram um acesso rápido e seguro a todo tipo de informação e conhecimento. O presente trabalho visa analisar a maneira pela qual alunos de segundo grau da rede estadual da cidade de São Paulo obtiveram, caso tenham, conhecimentos básicos de astronomia quanto aos fenômenos celestes que os rodeiam, tais como a sucessão dos dias e das estações do ano, além de questioná~los sobre fatos genéricos tais como: o que vem a ser o Sol, o Big Bang, o que ocasionou a extinção dos dinossauros. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, o qual foi aplicado no primeiro colegial diurno da Escola Estadual Guilherme de Almeida. Num espaço amostral de 44 alunos constatou-se que 41% dos alunos adquiriram seus conhecimentos astronômicos na escola e 59% através da mídia em geral. Neste mesmo espaço amostral apenas 11% dos alunos usaram computadores na escola, 41% na residência, 5% no trabalho e 43% não utilizaram. O presente estudo revelou também que para 50% dos alunos o professor jamais utilizou um programa de computador a respeito de astronomia ou fez alguma apresentação sobre o tema. Embora em sua fase inicial este estudo revela claramente que a maioria dos alunos não obtém na escola seus conhecimentos astronômicos, estes provém de fontes não especificamente didático-pedagógicas tais como filmes e revistas populares que não raramente geram conhecimentos incompletos e em muitos casos inclusive falhos.

  18. The diffuse seismicity of the Sierra Nevada of Santa Marta, the Perijá Range, and south of the La Guajira peninsula, Colombia and Venezuela: Result of the convergence between Caribbean plate and the South American margin during the Late Neogene?

    NASA Astrophysics Data System (ADS)

    Chicangana, G.; Pedraza, P.; Mora-paez, H.; Ordonez Aristizabal, C. O.; Vargas-Jimenez, C. A.; Kammer, A.

    2012-12-01

    A diffuse low deep microseismicity located overall between the Guajira peninsula and the Sierra Nevada de Santa Marta (SNSM) was registered with the recent installation (2008 to Present) of three seismological stations in northeastern Colombia by the Colombian Seismological Network (RSNC), but mainly with the Uribia station in (the) central region of La Guajira peninsula, The microseismicity is characterized by a great population of events with 1.2 < Ml < 3.0. and few events of 3.0 < Ml < 4.0 that sporadically occur. The poor number of seismological stations in this region of Colombia impedes to locate the origin of the local seismicity; however, this seismic activity is associated to the tectonic activity of the Oca fault because with the GPS displacement analysis, neotectonics evidence found in faults traces associated to the Oca fault and the historical earthquake that affected the Colombian city of Santa Marta in 1834, lead us to conclude this. This is a big cortical fault that sets the limit between La Guajira peninsula and the SNSM. Its cortical characteristics were verified from geological data together with gravimetric and seismic exploration. The SNSM limits toward the southeast with the Cesar - Ranchería basin, and this basin in turn limits with the Perijá Range that is localized in the Colombia - Venezuela border. The SNSM, Cesar - Ranchería basin and Perijá Range limit toward the southwest with the Bucaramanga - Santa Marta fault (BSMF), the Oca fault toward the north, and Perijá - El Tigre fault toward the southeast defining a pyramidal orogenic complex. Using remote sensing images data with geological and regional geophysical information, we proposed that this orogenic complex was originated as a result of the Panama arc with the northwestern South America accretion. The final adjustment of the Caribbean plate (CP) between North America and South America during the Late Neogene produced the big cortical faults systems activation like Oca - Moron - El Pilar in Colombia and Venezuela toward the south of the Caribbean Plate (CP), and Motegua - Walton - Enriquillo - Plantain Garden toward the north of the CP. This situation was originated of a new subduction development of the Nazca - Cocos plates toward the south and the west of the Panama arc; when this happened, the evolution of the Present - day configuration of the Nazca plate and Galapagos Spreading Center started. From the Early Pliocene, the BSMF and the Oca fault were reactivated: the BSMF, with a left lateral movement, and the Oca fault with a right lateral movement. This last mobility produces the cortical diffuse seismicity that we are showing here.

  19. Use of geostatistic techniques to describe a reservoir to be submitted into a secondary recovery process field case: {open_quotes}Eocene B-Inferior/VLG-3659, Ceuta, Venezuela{close_quotes}

    SciTech Connect

    Hernandez, T.; Poquioma, W.

    1997-08-01

    This study presents the results of an integrated reservoir study of the Eocene B-Inferior/VLG-3659, Area 7, Ceuta filed. This field located in the Maracaibo Lake in the western side of Venezuela. The objective was to evaluating the feasibility to implement a secondary recovery project by means of water flooding. Core information was used for this study (194 ft), PVT analysis, RFI, build-up and statistic`s pressure analysis, modem logs and production history data. Using geostatistical techniques (Kriging) it was defined a low uncertainty geological model that was validated by means of a black oil simulator (Eclipse). The results showed a good comparison of historical pressure of the reservoir against those obtained from the model, without the need of {open_quotes}history matching{close_quotes}. It means without modifying neither the initial rock properties nor reservoir fluids. The results of this study recommended drilling in two new locations, also the reactivation of four producing wells and water flooding under peripherical array by means of four injection wells, with the recovery of an additional 30.2 MMSTB. The economical evaluation shows an internal return rate of 31.4%.

  20. Estimación de pequeñas perturbaciones en satélites geocéntricos como un problema inverso

    NASA Astrophysics Data System (ADS)

    Zadunaisky, P. E.

    El movimiento geocéntrico de un satélite artificial es simulado automáticamente por un sistema de ecuaciones diferenciales de segundo orden que incluyen dos funciones perturbadoras. La primera representa el segundo término del potencial gravitatorio de la Tierra y la segunda corresponde al frenado atmosférico. Asumiendo como conocidas, por hipótesis o por mediciones, la posición y velocidad del satélite en instantes sucesivos se estiman las perturbaciones a intervalos sucesivos por un método determinístico. Para ilustrar el método y comprobar la precisión de nuestros resultados hemos simulado dos ejemplos incluyendo valores conocidos de las perturbaciones que luego comparamos con los resultados de nuestro método. El método puede aplicarse por ejemplo para el intervalo de una revolución satelital lo cual permitiría el diseño inmediato de una maniobra correctiva de la órbita satelital.

  1. Las fulguraciones como manifestación de reconexión en el campo magnético solar

    NASA Astrophysics Data System (ADS)

    Bagalá, L. G.; Mandrini, M. C.; Rovira, M. G.; Démoulin, P.

    Las fulguraciones solares son fenómenos transitorios de liberación de energía que se desarrollan en las estructuras magnéticas de las regiones activas del Sol. Las fulguraciones pueden llegar a liberar hasta 1032 erg en 100 seg. en todo el rango electromagnético, y acelerar partículas. En este trabajo mostramos que la ubicación de los abrillantamientos en H? de diversas fulguraciones está relacionado con las propiedades de las conexiones de las líneas del campo magnético de la región, como se espera por las teorías de reconexión en 3D recientemente desarrolladas (Démoulin et al, 1996a). El campo magnético coronal se extrapola del campo fotosférico observado suponiendo una configuración libre de fuerzas lineal. Por medio de un algoritmo se determinan las regiones donde existe un cambio drástico en la conectividad de las líneas de campo (límites ``cuasi-discontinuos'', o cuasi-separatrices CS). Las CS son bandas abiertas que identifican zonas donde el campo magnético se reconectará con más probabilidad y, siempre que las mismas sean lo suficientemente finas, se producirá allíla liberación de energía proveniente del campo magnético. Hemos encontrado que en todas las regiones fulgurantes estudiadas (Démoulin et al, 1996b) existen CS en los mismos lugares donde se observaron los abrillantamientos en H?. Allídonde coinciden los abrillantamientos con las CS, éstas tienen un espesor menor que 1 Mm. Las líneas de campo coronales extrapoladas de nuestro modelo tienen sus orígenes fotosféricos a ambos lados de las CS, como se espera dados los recientes estudios de reconexión magnética en 3D. Estos resultados ponen a prueba los modelos presentes sobre fulguraciones solares.

  2. codice licenza insegna chiusura toponimo indirizzo civico localit cap prov 256903 TAKE-AWAY C' ERA UNA VOLTA MAI VIA ANZANI 35 COMO 22100 CO

    E-print Network

    UNA VOLTA MAI VIA ANZANI 35 COMO 22100 CO 240881 BAR TAVOLA FREDDA GE-BAR MAI VIA CASTELNUOVO 5 COMO AILANTI 3 MILANO 20156 MI 120931 SELF SERVICE VIVA' DOMENICA VIA ALESSANDRO TADINO 36 MILANO 20124 MI

  3. Most frequent mutation c.3402delC (p.Ala1135GlnfsX13) among Wilson disease patients in Venezuela has a wide distribution and two old origins.

    PubMed

    Paradisi, Irene; De Freitas, Laura; Arias, Sergio

    2015-02-01

    Wilson disease is an infrequent autosomal recessive disorder caused by mutations in the ATP7B gene (13q14.3) producing pathologic phenotypes due to copper accumulation in critical tissues. The aim of the research was to probe Wilson disease genetic epidemiology in Venezuela, through the identification in diagnosed index cases, of ATP7B locus mutations, their geographic distribution, frequency, in-phase haplotypes and probable ethnic ancestry. During the last three decades 33 independent Wilson disease families from the country at large were ascertained and diagnosed through severely reduced ceruloplasmin activity, higher urinary copper excretion, and specific clinical signs. Molecular studies of the ATP7B gene were accomplished in 26 of the families. Disease prevalence was estimated as 1:94,000 families between 1985 and 2013, showing geographic aggregation in the state of Zulia with 1:27,000 families in it. DNA analysis in 26 families revealed 13 different mutations. The c.3402delC was the most frequent one (26.9%), presenting two independent in-phase haplotypes, both of likely European descent; which is followed by the not previously reported p.G691V (9.6%) and by the frequent European H1069Q (7.7%). Known mutations c.51 + 4A > T, c.1285 + 5G > T, M645R, T788I, V845SfsX28, T977M, L1088X, T1220M, R1319X and a novel P767L showed frequencies between 5.8 and 1.9%. Despite the ample mutation heterogeneity for Wilson disease in the country, the findings provide a diagnostic algorithm to ease mutation assessment in new patients; the predominant c.3402delC displayed wide geographic distribution and two genetic origins. PMID:25497208

  4. LA IMPORTANCIA DE LA FIRMA EN LAS PUBLICACIONES CIENTFICAS

    E-print Network

    Bilbao Arrese, Jesús Mario

    Alva Edison, 7 41092 Sevilla Consejos útiles para completar su firma Modificar las variantes de firma. Consejo Superior de Investigaciones Científicas (CSIC). Parque Científico y Tecnológico Cartuja. c/ Thomas

  5. DIABETES MELLITUS COMO FACTOR DE RIESGO DE DEMENCIA EN LA POBLACIÓN ADULTA MAYOR MEXICANA

    PubMed Central

    Silvia, Mejía-Arango; Clemente, y Zúñiga-Gil

    2012-01-01

    Introduccion La diabetes mellitus y las demencias constituyen dos problemas crecientes de salud entre la población adulta mayor del mundo y en particular de los paises en desarrollo. Hacen falta estudios longitudinales sobre el papel de la diabetes como factor de riesgo para demencia. Objetivo Determinar el riesgo de demencia en sujetos Mexicanos con diabetes mellitus tipo 2. Materiales y Metodos Los sujetos diabéticos libres de demencia pertenecientes al Estudio Nacional de Salud y Envejecimiento en México fueron evaluados a los dos años de la línea de base. Se estudió el papel de los factores sociodemográficos, de otras comorbilidades y del tipo de tratamiento en la conversión a demencia. Resultados Durante la línea de base 749 sujetos (13.8%) tuvieron diabetes. El riesgo de desarrollar demencia en estos individuos fue el doble (RR, 2.08 IC 95%, 1.59–2.73). Se encontró un riesgo mayor en individuos de 80 años y más (RR 2.44 IC 95%, 1.46–4.08), en los hombres (RR, 2.25 IC 95%, 1.46–3.49) y en sujetos con nivel educativo menor de 7 años. El estar bajo tratamiento con insulina incrementó el riesgo de demencia (RR, 2.83, IC 95%, 1.58–5.06). Las otras comorbilidades que aumentaron el riesgo de demencia en los pacientes diabéticos fueron la hipertensión (RR, 2.75, IC 95%, 1.86–4.06) y la depresión (RR, 3.78, 95% IC 2.37–6.04). Conclusión Los sujetos con diabetes mellitus tienen un riesgo mayor de desarrollar demencia, La baja escolaridad y otras comorbilidades altamente prevalentes en la población Mexicana contribuyen a la asociación diabetes-demencia. PMID:21948010

  6. Proc. of the 12th Int. Conference on Digital Audio Effects (DAFx-09), Como, Italy, September 1-4, 2009

    E-print Network

    Plumbley, Mark

    to produce a high quality representation of audio using similar techniques. Rather than defining newProc. of the 12th Int. Conference on Digital Audio Effects (DAFx-09), Como, Italy, September 1-4, 2009 ESTIMATING PARAMETERS FROM AUDIO FOR AN EG+LFO MODEL OF PITCH ENVELOPES Stephen J. Welburn

  7. A simple combinatorial method to discover Co-Mo binary catalysts that grow vertically aligned single-walled carbon nanotubes

    E-print Network

    Maruyama, Shigeo

    A simple combinatorial method to discover Co-Mo binary catalysts that grow vertically aligned single-walled carbon nanotubes Suguru Noda a,* , Hisashi Sugime a , Toshio Osawa a , Yoshiko Tsuji-ku, Tokyo 113-8656, Japan Abstract A simple yet versatile combinatorial method to discover binary metal

  8. Universidad Central de Venezuela Facultad de Ciencias

    E-print Network

    Coto, Ernesto

    ­ Computer Tomography), Resonancia Magnética (MR ­ Magnetic Resonance) y otras modalidades. En particular Resonancia Magnética (MRI ­ Magnetic Resonance Imaging), tomografía computarizada (CT ­ Computer Tomography

  9. Snubdrilling a new well in Venezuela

    SciTech Connect

    Aasen, J.

    1995-12-01

    A new well was successfully drilled using a snubbing jack. The drill bit was rotated using a rotary table, downhole motors and combination of the two. Expected high-pressure zones prompted this use of ``snubdrilling.`` The primary objective was to drill a vertical well through underlying sands and gain information about formation pressures. This data would aid in the drilling of a relief well using a conventional drilling rig. The secondary objective was to relieve pressure by putting this new well on production. In addition to special high-pressure drilling jobs, there are other drilling applications where snubbing jacks are a feasible alternative to conventional rotary drilling rigs or coiled tubing units. Slimhole, underbalanced and flow drilling, and sidetracking of existing wells are excellent applications for snubdrilling. Advantages of snubdrilling vs. coiled tubing drilling, include ability to rotate drillstrings, use high-torque downhole motors, pump at high rates and pressures, apply significant overpull in case of stuck pipe, and run casing and liners without rigging down. Shortcomings of drilling with snubbing jacks compared to coiled tubing are the need to stop circulation while making new connections and inability to run continuous cable inside workstrings.

  10. Hearing-Impaired Children in Venezuela: 1985.

    ERIC Educational Resources Information Center

    Schildroth, Arthur; And Others

    1987-01-01

    The 1984-85 Venezuelan Survey of Deaf Children collected information on 804 deaf students between ages 3 and 14. Among findings were that 29% of the cases were caused by maternal rubella, that 36% had additional handicaps, and that meningitis was the most frequently reported after-birth cause of hearing losses. (Author/DB)

  11. Late Glacial to Holocene environmental variabilities: A new multi-proxy paleolimnological study of sedimentary sequences from Como (northern Italy)

    NASA Astrophysics Data System (ADS)

    Höbig, N.; Martinelli, E.; Motella, S.; Michetti, A. M.; Livio, F.; Tinner, W.; Reicherter, K.; Castelletti, L.

    2012-04-01

    Lake Como (northern Italy) is the deepest Italian lake, reaching a depth of about 425 m. The lambda-shaped lake expands about 45 km in NE-SW direction. Southwards of the hydrologically closed western branch, two sediment cores of 70 m (S1) and 65 m length (S2) were taken in the year 2005 close to the cathedral of Como (Piazza Verdi). The drilling sites are located in the middle of the Southern Alps, some 300 m from the present-day lakeshore. The cores provide the first detailed Late Glacial to Holocene multi-proxy record for the Lake Como basin. Our research is aimed at investigating the environmental and geological evolution of the Insubria Region. The multi-proxy study of the stratigraphic sequences contain geophysical, geotechnical, sedimentological, paleobotanical, and radiocarbon analyses. They have been performed for core S1 and are still in progress on core S2. With this data the working group focuses on two main issues. The first topic is the reconstruction of the natural and anthropogenic processes controlling the ground subsidence in the Como urban area (e.g., Comerci et al., 2007) and another aim is to reconstruct vegetation and land-use dynamics. In particular, 150 samples of vegetal macroremains have been collected in the palustrine deposits along S1 core, down to 31,00 m. Below this depth (dated 14C 12,496 ± 55 yr BP - 15,050 - 14,250 cal yr BP), the amount of plant macroremains in the sediment drops dramatically. The taxonomic determination was carried out on more than 800 macroremains. They are represented by fragments of wood, leaves, needles, seeds, fruits, mosses and tiny charcoals (Motella, 2009, unpublished PhD Thesis). Picea/Larix, Pinus sp., Juniperus with Betula, found in the deeper levels (30.80 - 30.00 m), are the first arboreal taxa that colonized the shores of Lake Como, and show that the reforestation began in this area about 16,000 years ago. During the early Holocene (25.10 m) Abies alba expanded and further upwards the sequence mixed deciduous forests became important. Preliminary results of palynological analyses for a section of the core S2 (35.04 - 18.12 m), show Late Glacial sediments in the depth of 35.04 - 31.16 m, due to vegetation changes related to natural climatic variability, with an alternation of communities typical of cold (Poaceae, Artemisia, Juniperus, Pinus and Betula) and temperate climates (e.g. Quercus). Later, during the Holocene, forests composed by mostly deciduous broadleaves and Abies alba expanded. During the mid and late Holocene human impact increased and modified vegetation. This is shown by the increase of herbs and heliofilous shrubs (26.51 m), typical of deforested spaces for fields and pastures. Human exploitation of wood is represented for example by the dramatic decline of Abies alba (24.97 m). Finally, the increase of Cerealia (19.39 m) is clearly related to intensified agricultural activities. The results of further paleobotanical and geophysical analyses which are in progress will be presented during the conference. Moreover, geochemical measurements (e.g., XRF) will be performed in future for core S2. Researches realized within the project of Italy-Switzerland Cooperation SITINET "Censimento, valorizzazione e messa in rete di siti geologici e archeologici" (Census, increase of value and computerization of geological and archaeological sites). Interreg IV A "Geo-Archeositi dell'Insubria" (Geo-Archaeosites of Insubria).

  12. 3/8/2015 Conhea duas gachas que, em realidades distintas, usam o estudo como bandeira pela igualdade de gnero -Zero Hora http://zh.clicrbs.com.br/rs/noticias/noticia/2015/03/conheca-duas-gauchas-que-em-realidades-distintas-usam-o-estudo-como-bandei... 1/5

    E-print Network

    Barbosa, Marcia C. B.

    igualdade de gênero - Zero Hora http://zh.clicrbs.com.br/rs/noticias/noticia/2015/03/conheca-duas-gauchas como bandeira pela igualdade de gênero Da alfabetização ao pósdoutorado, Delaidia e Márcia são exemplos estudo como bandeira pela igualdade de gênero - Zero Hora http

  13. In-situ HRTEM study of the reactive carbide phase of Co/MoS2 catalyst.

    PubMed

    Ramos, Manuel; Ferrer, Domingo; Martinez-Soto, Eduan; Lopez-Lippmann, Hugo; Torres, Brenda; Berhault, Gilles; Chianelli, Russell R

    2013-04-01

    Hydrotreatment catalytic operations are commonly performed industrially by layered molybdenum sulfide promoted by cobalt or nickel in order to remove heteroelements (S, N, O) from fossil fuels and biofuels. Indeed, these heteroelements are responsible of the emission of pollutants when these fuels are used in vehicles. In this respect, previous studies made by our research group have shown that the active phase under steady state conditions is partially carbided while strong bending effects of MoS2 slabs were also observed. However, up to now, the morphology of the resulting Co/MoSxCy carbided catalyst has not been fully characterized. In the present study, for the first time, a chemical reaction between the carbon content of a TEM Cu/C grid and a freshly sulfide Co/MoS2 catalyst was in situ observed at 300 °C and 450 °C by HRTEM experimental techniques at ~10 nm of resolution. Results indicate that bending of MoS2 layers occurred due to carbon addition on MoS2 edge sites, as observed in stabilized catalysts after HDS reaction. Using a silicon grid, only cracks of MoS2 slabs were observed without bending effect confirming the role of structural-carbon in this change of morphology. PMID:22925737

  14. Counseling in the Republica Bolivariana de Venezuela (Bolivarian Republic of Venezuela)

    ERIC Educational Resources Information Center

    Montilla, R. Esteban; Smith, Robert L.

    2009-01-01

    Counseling is an emerging profession in Latin America that offers people an opportunity to voice pain, exercise power, authentically connect with others, and experience healing within the community. Counseling reflects collaborative efforts between consultant and consultee who come together to reach mutual healing and growth through the use of…

  15. Instrues de utilizao O badge do Centenrio do IST --que se apresenta e configura como um hyperlink para o respectivo website comemorativo

    E-print Network

    Instituto de Sistemas e Robotica

    como um hyperlink para o respectivo website comemorativo --, será a forma oficial de associação dos diversos websites dos serviços e/ou iniciativas do IST ao mesmo, por forma a assegurar uma consistência no canto superior direito do website. Assegure-se --através do visionamento do código-fonte-- que está

  16. COMO SE CONECTAR A REDE WIFI DA BIBLIOTECA Para conectar a rede WIFI da biblioteca a partir do notebook, siga os passos abaixo

    E-print Network

    Paraná, Universidade Federal do

    1 COMO SE CONECTAR A REDE WIFI DA BIBLIOTECA Para conectar a rede WIFI da biblioteca a partir do. Se caso apareça mais opções procure pela "Conectar-se a internet". 3º Passo: - Ao clicar em "Conectar-se as conexões disponíveis para você se conectar: 5º Passo: Ao serem procuradas e exibidas as conexões

  17. Percepción de competencia y adiestramiento profesional especializado relativos al VIH/SIDA en estudiantes y profesionales de la salud: el estigma como un indicador de necesidad

    PubMed Central

    RODRÍGUEZ, Yarimar ROSA; DÍAZ, Nelson VARAS

    2009-01-01

    El proceso de estigmatización asume una devaluación de la persona debido a una característica o marca que haya sido identificada socialmente y que permita que se le describa como diferente. Desde que se desató la epidemia del VIH/SIDA, vivir con la enfermedad ha sido señalado de manera social como una marca estigmatizante. Las manifestaciones de dicha estigmatización se han documentado entre profesionales de la salud. Este estigma puede afectar los servicios de salud que las personas que viven con VIH/SIDA reciben de estos profesionales. Los objetivos de esta investigación fueron explorar: 1) la percepción que tienen estudiantes y profesionales de la salud sobre su nivel de competencia para ofrecer servicios a personas que viven con VIH/SIDA, 2) las opiniones de éstos sobre el tipo de adiestramiento profesional recibido y la necesidad del mismo, y 3) la manifestación de actitudes estigmatizantes como indicadores de necesidad de adiestramiento profesional. La muestra total del estudio estuvo compuesta por 80 de diversas profesiones de la salud. Los resultados reflejan que algunos/as de los/as participantes han recibido formación en VIH pero ésta no ha sido suficiente para contrarrestar las nociones estigmatizantes. Discutimos las implicaciones de los resultados para investigaciones futuras y el desarrollo de intervenciones con vías de minimizar las nociones estigmatizantes en los escenarios de salud. PMID:20011236

  18. La Importancia de la Entrada, Descenso y Aterrizaje - Duration: 89 seconds.

    NASA Video Gallery

    Únase a Fernando Abilleira, un analista de trayectoria de la Oficina de Exploración de Marte de la NASA, y conozca todas la nuevas tecnologías desarrolladas dentro del nuevo Laboratorio Científico ...

  19. Tal Como Somos/Just As We Are: An Educational Film to Reduce Stigma towards Gay and Bisexual Men, Transgender Individuals & Persons Living with HIV/AIDS

    PubMed Central

    Ramirez-Valles, Jesus; Kuhns, Lisa M.; Manjarrez, Dianna

    2013-01-01

    In this paper we describe the development and dissemination of a film-based educational intervention to reduce negative attitudes towards gay and bisexual men and transgender women (GBT) and people living with HIV/AIDS (PLWHA) in Latino communities, with a focus on youth. The intervention, Tal Como Somos/Just as We Are, is based on stigma and attribution theories, extensive formative research, and community input. Evaluation findings among educators and school youth suggest the film has the potential to effectively impact attitudes towards GBT and PLWHA. The film and intervention are being disseminated using diffusion of innovations theory through community-based organizations, schools, television broadcasting and film festivals. PMID:24377496

  20. Tal Como Somos/just as we are: an educational film to reduce stigma toward gay and bisexual men, transgender individuals, and persons living with HIV/AIDS.

    PubMed

    Ramirez-Valles, Jesus; Kuhns, Lisa M; Manjarrez, Dianna

    2014-04-01

    In this article, the authors describe the development and dissemination of a film-based educational intervention to reduce negative attitudes toward gay and bisexual men, transgender women, and people living with HIV/AIDS in Latino communities, with a focus on youth. The intervention, Tal Como Somos/Just as We Are, is based on stigma and attribution theories, extensive formative research, and community input. Evaluation findings among educators and school youth suggest the film has the potential to effectively influence attitudes toward gay and bisexual men, transgender women, and people living with HIV/AIDS. The film and intervention are being disseminated using diffusion of innovations theory through community-based organizations, schools, television broadcasting, and film festivals. PMID:24377496

  1. 78 FR 53007 - Additional Designation, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ..., Angel); DOB 27 Mar 1972; POB Caracas, Venezuela; nationality Venezuela; citizen Venezuela; Cedula No. 11295239 (Venezuela) (individual) . Dated: August 21, 2013. Barbara C. Hammerle, Acting Director, Office...

  2. Composite power law holdup correlations in horizontal pipes F. Garcia a,*, R. Garcia b

    E-print Network

    Joseph, Daniel D.

    .D. Joseph c a School of Mechanical Engineering, Central University of Venezuela, Caracas 1051, Venezuela b Fluid Mechanics Institute, Central University of Venezuela, Caracas 1051, Venezuela c Department

  3. Structural interpretation along the Icotea Fault, Lake Maracaibo, Venezuela

    SciTech Connect

    Bueno, E.; Zubizarreta, J.; Pinto, J.; Taylor, C.; Prieto, E. )

    1993-02-01

    This structural interpretation, performed on an interactive workstation, corresponds to an area covered by three 3D seismic surveys in Lake Maracaibo. These surveys (Block I, Northern and Southern Lama) focus on the Icotea fault trend, which is one of the major structural features in the Maracaibo Basin. The present study is centered on the interpretation of the origin and evolution of this fault trend. The Maracaibo Basin evolved from an initial phase dominated by extensional tectonism to a later compressional phase. The Icotea fault is interpreted as the border of a Triassic-Jurassic half graben. Subsequent to the deposition of shelf sediments, the fault became reactivated during the Paleocene and Lower to Middle Eocene. During the change to compressional tectonics within the upper Eocene, the half graben became inverted. As an associated event during the structural inversion, a sinistral strike slip deformation took place along the fault. The latest stage of faulting developed during Miocene, and resulted in lateral offsets along the Icotea fault system.

  4. Geomorphology of the Gran Sabana, Guayana Shield, southeastern Venezuela

    NASA Astrophysics Data System (ADS)

    Briceño, Henry O.; Schubert, Carlos

    1990-06-01

    The forms of the Gran Sabana have been developed mainly on rocks of the gently folded Precambrian Roraima Group, a sequence of quartzites and siliceous conglomerates, with intercalated jasper, chert, arkose, siltstone, and shale, locally intruded by diabase dikes and sills. Two planation surfaces are preserved on the Gran Sabana: the Auyán-tepui (2000-2900 m elevation) and the Wonken (900-1200 m) Surfaces, with a speculative Mesozoic initial age; they are still extending. Table mountains dominate the landscape. They comprise pediments, foothills, precipitous scarps hundreds of meters high, a rim, and a flattish summit. The table-mountain topography is controlled by joint systems; water percolates along joints and bedding planes, dissolves the siliceous cement, the quartzite disaggregates, and large blocks are isolated and collapse, accumulating at the foot of the scarps and on top of the table-mountain summits. The percolating water forms large and intricate cave systems, which frequently emerge in the scarp zone as high waterfalls. These mark the lowest level of erosion of the table mountains. Karstic structures are prominent in the summit zone. The evolution of the table-mountain topography has been controlled by a combination of tectonic, structural, stratigraphic, climatic, and temporal factors.

  5. The Resource Relationship: The Institutional Legacies of Oil in Venezuela

    NASA Astrophysics Data System (ADS)

    Bridgewater, Elliot

    This thesis problematizes the concept of the 'Resource Curse', addressing the arguments of several theorists that resource dependence results in state monopolization of natural resource production, and causes poor development outcomes in resource dependent states. A single case study of the Venezuelan experience is used in order to take a longer-run historical approach that considers economic and political determinants of oil-dependent development starting with the impressive growth and emerging democracy of the post war period, economic stagnation of the 1980's and 1990's, and the divisive contemporary era of 'Chavismo'. To deconstruct the thesis that oil and development do not mix, each chapter explores the dynamic connections between the fiscal structure of the Venezuelan state, institutionalized patterns of political conflict and compromise, and their socio-economic consequences. It is argued that such a multi-faceted approach moves beyond static interpretations of the resource curse to grasp more firmly the ever-changing resource relationship.

  6. Genetic Variability of Apolipoprotein E in Different Populations from Venezuela

    PubMed Central

    Fernández-Mestre, M. T.; Yehirobi, Castro; Montagnani, S.; Balbas, O.; Layrisse, Z.

    2005-01-01

    The genetic variation at the Apolipoprotein E locus (APOE) is an important determinant of plasma lipids and has been implicated in various human pathological conditions. The objective of the present study was to estimate the distribution of APOE alleles in five Venezuelan communities: two Amerindian tribes (Bari and Yucpa), one Negroid population from Curiepe, one Caucasoid population from Colonia Tovar and the mestizo urban population living in Caracas. The APOE*3 allele was the most common allele in all populations studied. However, a significant increase in the APOE*2 allele frequency in the Mestizo (18.96%) and Negroid (16.25%) populations was found. Similar to results reported in other Native American populations we have found that the APOE*2 allele is completely absent in the Bari and Yucpa Amerindians. Frequencies found in the Colonia Tovar population are in agreement with those reported in the population of Germany, indicating a high degree of relatedness. The results support the notion that the distribution of the APOE alleles shows ethnic variability. PMID:15735320

  7. Measuring political polarization: Twitter shows the two sides of Venezuela.

    PubMed

    Morales, A J; Borondo, J; Losada, J C; Benito, R M

    2015-03-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Chávez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network. PMID:25833436

  8. Mass Schooling for Socialist Transformation in Cuba and Venezuela

    ERIC Educational Resources Information Center

    Griffiths, Tom G.; Williams, Jo

    2009-01-01

    In contemporary contexts of Education for All and emphases on national educational performance, mass education globally continues to be strongly informed by human capital thinking, and by notions of developing future world citizens and workers for the international economy. In this paper, our central focus is on the ongoing educational project of…

  9. Schooling for Twenty-First-Century Socialism: Venezuela's Bolivarian Project

    ERIC Educational Resources Information Center

    Griffiths, Tom G.

    2010-01-01

    The global dominance of neoliberal policy prescriptions in recent decades has been well documented, with particular implications for educational systems. These include reduced public expenditure and provision, the promotion of individual (parental) choice, competition, increased user-pays and the privatisation of education. Against this…

  10. Measuring Political Polarization: Twitter shows the two sides of Venezuela

    E-print Network

    Morales, A J; Losada, J C; Benito, R M

    2015-01-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Ch\\'avez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  11. The gravity field and plate boundaries in Venezuela

    E-print Network

    Folinsbee, Robert Allin

    1972-01-01

    Free-air and simple Bouguer anomaly maps of the Venezuelan continental margin (from 60°W to 72°W and from 7°N to 13°N) are presented. The major features of the free-air map are: the large lows associated with the deep ...

  12. Mud volcanoes of the Orinoco Delta, Eastern Venezuela

    USGS Publications Warehouse

    Aslan, A.; Warne, A.G.; White, W.A.; Guevara, E.H.; Smyth, R.C.; Raney, J.A.; Gibeaut, J.C.

    2001-01-01

    Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Measuring political polarization: Twitter shows the two sides of Venezuela

    NASA Astrophysics Data System (ADS)

    Morales, A. J.; Borondo, J.; Losada, J. C.; Benito, R. M.

    2015-03-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Chávez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  14. Late quaternary evolution of the Orinoco Delta, Venezuela

    USGS Publications Warehouse

    Warne, A.G.; Guevara, E.H.; Aslan, A.

    2002-01-01

    The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel from incising as deeply as many other major river systems. Shallow seismic data indicate that the late Pleistocene Orinoco incised into the present continental shelf, where it formed a braided-river complex that transported sediment to a series of shelf-edge deltas. As sea level rose from 16,000 to 9,500 yrs BP, the Orinoco shoreline shifted rapidly landward, causing shallow-marine waves and currents to form a widespread transgressive sand unit. Decelerating sea-level rise and a warmer, wetter climate during the early Holocene (9,500 to 6,000 yrs BP) induced delta development within the relatively quiet-water environment of the EVB embayment. Sea level approached its present stand in the middle Holocene (6,000 to 3,000 yrs BP), and the Orinoco coast prograded, broadening the delta plain and infilling the EVB embayment. Significant quantities of Amazon sediment began to be transported to the Orinoco coast by littoral currents. Continued progradation in the late Holocene caused the constriction at Boca de Serpientes to alter nearshore and shelf hydrodynamics and subdivide the submarine delta into two distinct areas: the Atlantic shelf and the Gulf of Paria. The increased influence of littoral currents along the coast promoted mudcape development. Because most of the water and sediment were transported across the delta plain through the Rio Grande distributary in the southern delta, much of the central and northwestern delta plain became sediment starved, promoting widespread accumulation of peat deposits. Human impacts on the delta are mostly associated with the Volca??n Dam on Can??o Manamo. However, human activities have had relatively little effect on the delta processes and environments.

  15. Sequence stratigraphy of the Misoa Formation (Eocene) Lake Maracaibo, Venezuela

    SciTech Connect

    Marais-Gilchrist, G.; Higgs, R. )

    1993-02-01

    A preliminary sequence analysis of the Misoa Formation has been done in the Maraven concession area, Lake Maracaibo, using well logs supported by palynological and seismic data. The Misoa Formation is interpreted to comprise a lower transgressive unit containing at least four third-order cycles (lithostratigraphic units C7 to C3, approximately), and an upper dominantly regressive unit consisting of six third-order cycles (approximately C2 to B1). A major flooding surface (gamma-ray log maximum) provides a marker near the top of the lower unit, almost coincident with the important N-M local pollen zone. A tentative correlation can be achieved with the Haq-Vail coastal onlap curves for the Tejas A 2.3 to 3.3 third-order cycles, 55 to 44 ma. The maximum flooding surface would correlate with the maximum Eocene onlap at 52.5 ma. These ages broadly agree with the local pollen zonation. Incised valley fill units interpreted on the basis of blocky log character in some wells could have accumulated during global Eocene sea level falls, particularly those between 55 and 54 ma. The sequences gradually onlap onto the Paleocene unconformity and converge in a southwestward (landward) direction. Although north-south-oriented high-angle sinusoidal events are evident on some seismic lines, these are thought to indicate rotated listric fault-bounded blocks formed during an extensional episode, possibly syn-Misoa. The study should aid exploration for stratigraphic traps in the lake area.

  16. The bee genus Caenaugochlora in Venezuela (Hymenoptera: Halictidae)

    E-print Network

    Engel, Michael S.

    2014-05-12

    Two new species of the augochlorine bee genus Caenaugochlora Michener are described and figured. Caenaugochlora (Caenaugochlora) elpidia Engel, new species, and C. (C.) pantochlora Engel, new species, are the first formally described species...

  17. LA ASAMBLEA NACIONAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA

    E-print Network

    Vásquez, Carlos

    la equidad y la inclusión; la sustentabilidad del desarrollo, el derecho a la igualdad de género, el, la igualdad entre todos los ciudadanos y ciudadanas sin discriminaciones de ninguna índole, la aseguren a todos y todas igualdad de condiciones y oportunidades, y la promoción de la participación

  18. Co-Doped MoS2 Nanosheets with the Dominant CoMoS Phase Coated on Carbon as an Excellent Electrocatalyst for Hydrogen Evolution.

    PubMed

    Dai, Xiaoping; Du, Kangli; Li, Zhanzhao; Liu, Mengzhao; Ma, Yangde; Sun, Hui; Zhang, Xin; Yang, Ying

    2015-12-16

    Highly active and low-cost catalysts for hydrogen evolution reaction (HER) are crucial for the development of efficient water splitting. Molybdenum disulfide (MoS2) nanosheets possess unique physical and chemical properties, which make them promising candidates for HER. Herein, we reported a facile, effective, and scalable strategy by a deposition-precipitation method to fabricate metal-doped (Fe, Co, Ni) molybdenum sulfide with a few layers on carbon black as noble metal-free electrocatalysts for HER. The CoMoS phase after thermal annealing in Co-doped MoS2 plays a crucial role for the enhanced HER. The optimized Co-doped MoS2 catalyst shows superior HER performance with a high exchange current density of 0.03 mA·cm(-2), low onset potential of 90 mV, and small Tafel slope of 50 mV·dec(-1), which also exhibits excellent stability of 10000 cycles with negligible loss of the cathodic current. The superior HER activity originates from the synergistically structural and electronic modulations between MoS2 and Co ions, abundant defects in the active edge sites, as well as the good balance between active sites and electronic conductivity. Thanks to their ease of synthesis, low cost, and high activity, the Co-doped MoS2 catalysts appear to be promising HER catalysts for electrochemical water splitting. PMID:26599427

  19. Thermal effects on Co/Mo2C multilayer mirrors studied by soft x-ray standing wave enhanced photoemission spectroscopy

    NASA Astrophysics Data System (ADS)

    Giglia, A.; Mukherjee, S.; Mahne, N.; Nannarone, S.; Jonnard, P.; Le Guen, K.; Yuan, Y.-Y.; André, J.-M.; Wang, Z.-S.; Li, H.-C.; Zhu, J.-T.

    2013-05-01

    Here is presented the spectroscopic study of the evolution of the first buried interfaces of a B4C capped Co/Mo2C multilayer mirror induced by thermal treatment up to 600°C. This kind of study is typically performed to simulate the response of multilayer optics working in extreme conditions, as for instance when irradiated by new high brilliance sources as Free Electron Lasers. In fact, the efficiency of multilayers is related to the optical contrast between the alternating high and low density layers, and then to the degree of interdiffusion and the creation or evolution of interface compounds. The analysis has been performed at the Co L23 edge with different soft x-ray spectroscopic techniques including diffuse and specular reflectivity, total electron and fluorescent yield at the BEAR beamline at Elettra (Trieste) (http://www.elettra.trieste.it/elettra-beamlines/bear.html). The presentation is focused on the spectroscopic results obtained by soft x-ray standing wave enhanced photoemission (XSW) from the Mo 3d, B 1s, C 1s, O 1s core levels by using a photon energy close to the Co L23 edge and corresponding to the first Bragg peak of the multilayer. The experimental results have been compared with simulations to obtain information both on the chemical state (e.g. oxidation state) and interface morphology in terms of profiles of distribution of elements and interdiffusion of B, oxidized B and C in the interface region. In summary, it is possible to conclude in favour of a good stability of the multilayer in the investigated temperature range, as confirmed by the good performance in terms of reflectivity. These results confirm the usefulness of XSW for this kind analysis of multilayer optics.

  20. 2.2.5 Determinar los enteros n tales que d|n d = n2 Solucion: Como uno de los divisores va a ser siempre el propio n, bus-

    E-print Network

    Cilleruelo, Javier

    2.2.5 Determinar los enteros n tales que d|n d = n2 . Soluci´on: Como uno de los divisores va a ser pareja r tal que dr = n. Si tuviera m´as divisores, el producto ser´ia mayor, y en el que caso que n sea