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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.

    PubMed

    1982-02-01

    This discussion of Venezuela reviews the following: the history of the country's demographic situation; the government's overall approach to population problems; statistical systems and development planning; institutional arrangements for the integration of population within development planning; the government's view of the importance of population policy in realizing development objectives; population size, growth, and natural increase; morbidity and mortality; fertility; international migration; and spatial distribution. Over the 1920-1961 period Venezuela's level of fertility was high and continued to rise gradually. The crude birth rate was around 40.0/1000 population in 1920, 44.0/1000 in 1950, and 45.0/1000 in 1961, and thereafter began to decline, dropping to a level of 38.4/1000 by 1971. During the same period, mortality underwent a steady decline, with the crude death rate falling from 30.0/1000 population in 1920 to 13.7 in 1950, 7.4 in 1961, and to 6.6 by 1971. Venezuela's government has no policy of intervention to modify fertility or population growth but has relied primarily on the benefits of rapid economic growth to achieve a rate of demographic growth that is compatible with its development objectives. Since 1920, 7 modern censuses have been conducted. The most recent census was in 1971. The registration data are classified as incomplete. Multiround sample household surveys were conducted in 1976-1977 and 1978. The government has not established a special unit for population policies. It assigned this function to the Central Planning Agency in 1975. The government has not announced a comprehensive population policy, but it has been moving in the direction of formulating more comprehensive policies in 2 areas of concern--international migration and spatial distribution. The government considers the current rate of population growth to be satisfactory despite the fact that it is rather high by Latin American standards. The government also considers levels and trends of mortality to be acceptable, given current economic and social circumstances. The government currently considers levels and trends of immigration to be significant and unsatisfactory because they are too high. The country is now more than 75% urban. The government considers the distribution of population within the national territory to be inappropriate and to require substantial modification. PMID:12279318

  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. Astronomy in Venezuela

    NASA Astrophysics Data System (ADS)

    Rosenzweig, Patricia

    Since the installation of the Observatorio Cagigal in Caracas, astronomy in Venezuela has developed steadily, and, in the last few decades, has been strong. Both theoretical and observational astronomy now flourish in Venezuela. A research group, Grupo de Astrofísica (GA) at the Universidad de Los Andes (ULA) in Mérida, started with few members but now has increased its numbers and undergone many transformations, promoting the creation of the Grupo de Astrofísica Teórica (CAT), and with other collaborators initiated the creation of a graduate study program (that offers master's and doctor's degrees) in the Postgrado de Física Fundamental of ULA. With the financial support of domestic Science Foundations such as CONICIT, CDCHT, Fundacite, and individual and collective grants, many research projects have been started and many others are planned. Venezuelan astronomy has benefitted from the interest of researchers in other countries, who have helped to improve our scientific output and instrumentation. With the important collaboration of national and foreign institutions, astronomy is becoming one of the strongest disciplines of the next decade in Venezuela.

  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. Undocumented migration to Venezuela.

    PubMed

    Van Roy, R

    1984-01-01

    "In 1980 Venezuela took...steps to regularize the undocumented migrant population. While the number responding to the amnesty was small relative to expectations, the majority of illegals appeared to have regularized their status. For the first time it was possible to assess objectively the characteristics of the undocumented population. Moreover, the problem of illegal migrants seems to have been temporarily solved, a result of both the amnesty and the country's declining economic activity." Topics covered in the present article include the nationality, geographic distribution, sex and age distribution, educational status, and occupations of undocumented migrants. PMID:12339922

  8. 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,…

  9. 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,…

  10. Geothermal reconnaissance of northeastern Venezuela

    SciTech Connect

    Urbani, F. )

    1989-01-01

    About 60% of Venezuela has been covered by a reconnaissance geothermal survey that includes geologic and water geochemical studies. The information is stored in a computerized data bank that holds data from 361 geothermal localities. The subsurface reservoir temperatures of the geothermal systems have been estimated using chemical geothermometry and mixing models and in many cases conceptual geothermal modes have been postulated. Preliminary assessments of the northeastern Venezuelan geothermal systems indicate that the most promising system is Las Minas near El Pilar in the state of Sucre, with an estimated deep reservoir temperature of 200-220{sup 0}C. Further studies are intended to evaluate its potential for electricity generation. Based on present data, other medium and low temperature systems in Venezuela appear useful for direct applications.

  11. 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

  12. 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.

  13. 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)

  14. 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}

  15. 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.

  16. Venezuela slates second oil field revival round

    SciTech Connect

    Not Available

    1992-12-07

    This paper reports that Venezuela will accept bids under a second round next year from private foreign and domestic companies for production contracts to operate marginal active as well as inactive oil fields. The first such round came earlier this year, involving about 55 other marginal, inactive fields. It resulted in two contractors signed with domestic and foreign companies. It represented the first time since nationalization of the petroleum industry in Venezuela in 1976 that private companies were allowed to produce oil in the country. A public bid tender was expected at presstime last week.

  17. 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…

  18. 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.

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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)

  6. Language Planning for Venezuela: The Role of English.

    ERIC Educational Resources Information Center

    Kelsey, Irving; Serrano, Jose

    A rationale for teaching foreign languages in Venezuelan schools is discussed. An included sociolinguistic profile of Venezuela indicates that Spanish is the sole language of internal communication needs. Other languages spoken in Venezuela serve primarily a group function among the immigrant and indigenous communities. However, the teaching of…

  7. View of the Caribbean coast of Venezuela

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A near vertical view of the Caribbean coast of Venezuela is seen in this Skylab 3 Earth Resources Experiment Package S190-B (five-inch earth terrain camera) photograph taken from the Skylab space station in Earth orbit. The large body of water is the Golfo de Venezuela; and the major land mass is the Peninsula de Paraguana. The view is looking northward from the mouth of the Golfete de Coro and Punta Cardon to Punta Macolia. The peninsula is connected to the Venezuelan mainland by the narrow strip of land in the most easterly corner of the picture. The dry, arid climate of the peninsula is indicated by sparse vegetation and the abundance of sand dunes. The highest point is about 2,700 feet above the sea and is the conspicuous black spot. Old raised shorelines features appear as streaks parallel to the Golfete de Coro. Water of the Golfete de Coro is red from the high sediment content. The streaks in the water off the peninsula is apparently an effect of wind which is blowing sand and w

  8. [Zika virus: Another emerging arbovirus in Venezuela?].

    PubMed

    Valero Nereida

    2015-09-01

    Current health conditions of Venezuela, together with the tropical proliferation of different types of Aedes (aegypti and albopictus), suggest the arrival to this country of ZIKA virus (ZIKV). The Pan American Health Organization urges Latin American countries to take measures to prevent the ZIKV entry and advises that these measures must be designed to detect the introduction of ZIKV in an area, track its spread and actively monitor the disease. In Venezuela and other Latin-American countries, where endemicity is high for other arboviruses such as dengue arid chikungunya, health authorities should strengthen their surveillance systems to detect early and timely introduction of ZIKV ap.d refine diagnostic methods to confirm the infection rate; however, the high incidence of cases due those viral agents reflects weakened and poorly timed insensitive monitoring systems, as well as, poor vector control measures, arising the questions: will this arbovirus pop in our country, will it set as the other as edemicepidemic and lead to alter their clinical behavior and severity of the disease? PMID:26710538

  9. [Three phases of homicidal violence in Venezuela].

    PubMed

    Briceño-León, Roberto

    2012-12-01

    Venezuela was considered one of the least violent countries in Latin America, however by 2010 it was among the countries with the highest homicide rate. This article analyzes the evolution of homicides in Venezuela between 1985 and 2010 and proposes the existence of three stages which correspond to trends in social and political institutions of the country. The first from 1985 to 1993, characterized by the looting of 1989 and the coups d'état of 1992, when for the first time the homicide rate rose from 8 to 20. The second phase from 1994 to 1998 was a recovery period of the institutional and political stability when the homicide rate remained constant at around 20. The third phase began in 1999 with the H Chavez government and the institutional destruction that comes with the Bolivarian revolution and caused an increase in the rate of 20 to 57 homicides per 100 thousand inhabitants. This article argues that the explanation for the changes in the phases is to be found in the transformation of social and political institutions. PMID:23175399

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

    PubMed

    Thomson, Robin E; Holzenthal, Ralph W

    2012-01-01

    Eight new species of Hydroptilidae (Trichoptera) from Venezuela are described: Acostatrichia digitatasp. n., Hydroptila cressaesp. n., Metrichia botrychionsp. n., Ochrotrichia spirasp. n., Oxyethira bettyaesp. n., Oxyethira quiramaesp. n., Oxyethira reduncasp. n., and Rhyacopsyche shortisp. 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

  11. 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.

  12. 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

  13. 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.

  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. 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…

  16. 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.

  17. Composition and Ultrastructure of Streptomyces venezuelae

    PubMed Central

    Bradley, S. G.; Ritzi, Donna

    1968-01-01

    Streptomyces venezuelae is a filamentous bacterium with branching vegetative hyphae embedded in the substrate and aerial hyphae bearing spores. The exterior of the spore is inlaid with myriads of tiny rods which can be removed with xylene. The spore wall is approximately 30 nanometers thick. Occasionally, it can be seen that the plasma membrane and the membranous bodies within a spore are connected. The spore's germ plasm is not separated from the cytoplasm by a nuclear envelope. The cell walls of the vegetative hyphae, which are about 15 nanometers thick, are structurally and chemically similar to those of gram-positive bacteria. The numerous internal membranous bodies, some of which arise from the plasma membrane of the vegetative hypha, may be vesicular, whirled, or convoluted. Membranous bodies are usually prominent at the hyphal apices and are associated with septum formation. The germ plasm is an elongate, contorted, centrally placed area of lower electron density than the hyphal cytoplasm. The spores differ from the vegetative hyphae, not only in fine structure, but also in the arginine and leucine contents of their total cellular proteins. Images PMID:5669907

  18. Atmospheric formic and acetic acids in Venezuela

    NASA Astrophysics Data System (ADS)

    Sanhueza, Eugenio; Figueroa, Luis; Santana, Magaly

    Gas, phase and rain concentrations of HCOOH and CH 3COOH have been measured at various sites in the savannah climatic region, a cloud forest site and a coastal site in Venezuela. Gas phase and rain water were sampled using the aqueous scrubber technique and a wet only collector, respectively. Analyses were made by ion chromatography. The results indicate that formic and acetic acids are important components of the Venezuelan atmosphere. They are homogeneously distributed, suggesting a widespread source. Boundary layer concentrations during the dry season (HCOOH, 1.8 ppbv; CH 3COOH, 1.25 ppbv) are higher than in the wet season (HCOOH, 1.0 ppbv; CH 3COOH, 0.7 ppbv), mainly due to a longer lifetime of the acid during the dry season (˜6 days) compared with the wet season (˜2 days). The overall concentrations in rain are 7.0 and 4.0 μM for formic and acetic acids, respectively. The estimated annual total depositions are: HCOOH, 17 mmol m -2 yr -1 and CH 3COOH,10 mmol m -2 yr -1; around half of the acids are removed by dry deposition. It is established that a larger source (˜1.8 times) of both acids is present during the wet season. We speculate that atmospheric oxidation of hydrocarbons should be the main source of HCOOH and CH 3COOH in the Venezuelan atmosphere; soil emissions could make a significant contribution during the dry season.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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).

  5. Poverty rates in Venezuela: getting the numbers right.

    PubMed

    Weisbrot, Mark; Sandoval, Luis; Rosnick, David

    2006-01-01

    This article looks at household and individual poverty rates in Venezuela over the past seven years. For more than a year, the statement that poverty in Venezuela has increased under the government of President Hugo Chávez has appeared in scores of major newspapers, on major television and radio programs, and even in publications devoted to foreign policy. There are no data to support such statements, and in fact the available data show a decline in poverty for both individuals and households over the seven-year period: the percentage of people in poverty declined from 50 percent in the first quarter of 1999 to 43.7 percent in 2005. Further, there is no evidence to suggest any change in the methodology for measuring poverty during this period, as has been alleged in a number of reports. The article also examines briefly the impact of significant changes in non-cash benefits such as free health care, which are not taken into account in the measured poverty rate, on poor people in Venezuela. Finally, the authors look at how the mistakes in reporting on Venezuela's poverty rate were made; an appendix gives examples of mistakes in major media and foreign policy publications. PMID:17175848

  6. 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

  7. 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.

  8. 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.

  9. Primary amoebic meningoencephalitis: a new case from Venezuela.

    PubMed

    Caruzo, Giusseppe; Cardozo, José

    2008-10-01

    Primary amoebic meningoencephalitis (PAM) is not often seen. To date, less than 300 cases have been communicated to the medical literature since the disease was first discovered in 1965. Six of these reports originated in Venezuela. The authors describe a new spontaneous case of PAM in a 33-year-old previously healthy Western-Venezuelan man. PMID:18820207

  10. State-Led Education for Democratic Socialism: Venezuela's Education Missions

    ERIC Educational Resources Information Center

    Duffy, Maura

    2015-01-01

    Venezuela's "Bolivarian Revolution" is conceptualised as an anti-neoliberal project that aims to promote fundamental changes in the configuration of political power via processes of state-grassroots collaboration. Central to this process is an emphasis on the key role of education in the development of a 21st Century socialism based on…

  11. State-Led Education for Democratic Socialism: Venezuela's Education Missions

    ERIC Educational Resources Information Center

    Duffy, Maura

    2015-01-01

    Venezuela's "Bolivarian Revolution" is conceptualised as an anti-neoliberal project that aims to promote fundamental changes in the configuration of political power via processes of state-grassroots collaboration. Central to this process is an emphasis on the key role of education in the development of a 21st Century socialism based on…

  12. [Molecular characterization of Sigmodon hirsutus (Rodentia: Cricetidae) populations in Venezuela].

    PubMed

    Lessmann, Janeth; Arrivillaga, Jazzmín; Aguilera, Marisol

    2011-06-01

    Recent phylogenetic studies based on cytochrome b gene sequence, have determined that the species historically known as Sigmodon hispidus (Rodentia) from South America comprises a species S. hirsutus of paraphyletic origin. The aim of this study was to test the hypothesis that populations from Venezuela, represent the sensu strict form, ancestral haplotypes, and monophyletic subspecieS. For this, 12 individual sequences from three localities of different biogeographic regions in Venezuela were evaluated and sequenced based on cyto b. Additionally, the sequences were used to develop a cladistic analysis and genetic distance calculations, and to compare this information with two individual sequences of Sigmodon specimens available in Genbank. Phylogenetic analyses show that the three populations of S. hirsutus of Venezuela form an ancestral and monophyletic subclade supported by high bootstrap values and significant genetic distance between subclade within the S. hirsutus. Besides, the existence of two lineages suggests two subspecies, S. hirsutus hirsutus from Venezuela, and S. hirsutus mexicanus from Mexico-Central America, but, both species need formal description. PMID:21721239

  13. 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...

  14. Creutzfeldt-Jakob disease in Venezuela. A case report.

    PubMed

    Caraballo, A J

    1991-06-01

    A case of Creutzfeldt-Jakob disease (CJD) in a 32 year old man is presented. The clinical picture included a rapid progressive dementia associated with ataxia, global aphasia, myoclonus and pyramidal signs, death occurred after 13 months. The diagnosis of CJD was confirmed by CT and neuropathological studies. This is the first report of CJD occurring in Venezuela. PMID:1810244

  15. Crustal thickness variations in Venezuela from deep seismic observations

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Avila, J.; Bezada, M.; Vieira, E.; Yáñez, M.; Levander, A.; Zelt, C. A.; Jácome, M. I.; Magnani, M. B.; The Bolivar Active Seismic Working Group

    2008-11-01

    The Caribbean-South America plate boundary zone is a complex zone of plate interactions, forming thrust belts and foreland basins in northern Venezuela. Within the framework of the BOLIVAR and GEODINOS projects, the geodynamics of plate interactions is being investigated using interdisciplinary geological and geophysical methods. Here, we focus on the results of the land based active seismic observations done in 2004 along four deep seismic wide angle profiles, acquired perpendicular to the Caribbean-South America plate boundary in northern Venezuela between longitudes 63° W and 70° W, and ranging from about latitudes 12 °N to about 9 °N. The mostly unreversed profiles provide information on the crustal structure from the oceanic-transitional crust on the southern border of the Caribbean plate to the continental crust of the Caribbean Mountain System and their associated foreland basins, which are bordered to the south by the Guayana Shield, which corresponds to stable South America plate. The derived crustal thickness oscillates around 35 km along the coastline, corresponding to the Caribbean Mountain System, and decreases only slightly towards the Leeward Antilles. To the south, in the area of the Eastern Venezuela Basin, crustal thickness reaches 40 km, increasing towards the Guayana Shield to 45 km. Nevertheless, there are two regions of anomalous crustal thickness, proven by arrivals from the lower crust and the Moho discontinuity. In the eastern part of the Eastern Venezuela Basin, crustal thickness reaches up to 50 km, with high velocity anomalies within the lower crust, which are interpreted as reworked lower crustal and upper mantle material, associated to the plate interactions of the South American and the Caribbean plates. The second anomalous zone is a remarkable crustal thinning from 35 km to 27 km in the Falcón Basin in western Venezuela, which extends eastwards into the Bonaire Basin, as documented by PmP reflections derived from land shots, and observations of the air gun blasts on the stations of the Venezuelan seismological network.

  16. 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

  17. 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.

  18. Biosynthesis of glycosylated derivatives of tylosin in Streptomyces venezuelae.

    PubMed

    Han, Ah Reum; Park, Sung Ryeol; Park, Je Won; Lee, Eun Yeol; Kim, Dong-Myung; Kim, Byung-Gee; Yoon, Yeo Joon

    2011-06-01

    Streptomyces venezuelae YJ028, bearing a deletion of the entire biosynthetic gene cluster encoding the pikromycin polyketide synthases and desosamine biosynthetic enzymes, was used as a bioconversion system for combinatorial biosynthesis of glycosylated derivatives of tylosin. Two engineered deoxysugar biosynthetic pathways for the biosynthesis of TDP-3-O-demethyl-D-chalcose or TDP-Lrhamnose in conjunction with the glycosyltransferaseauxiliary protein pair DesVII/DesVIII were expressed in a S. venezuelae YJ028 mutant strain. Supplementation of each mutant strain capable of producing TDP-3-O-demethyl- D-chalcose or TDP-L-rhamnose with tylosin aglycone tylactone resulted in the production of the 3-O-demethyl- D-chalcose, D-quinovose, or L-rhamnose-glycosylated tylactone. PMID:21715968

  19. Brucella suis infections in collared peccaries in Venezuela.

    PubMed

    Lord, V R; Lord, R D

    1991-07-01

    A bacteriologic and serologic study was conducted on two ranches in the states of Apure and Guarico, Venezuela for brucellosis in collared peccaries (Tayassu tajacu). One hundred thirty-nine peccaries were necropsied and tissues were cultured. Forty-three isolations of Brucella suis biovar 1, were made from lymph nodes and spleens of 25 males and 18 females. Antibody to Brucella sp. was detected in sera from 122 animals by the rapid plate agglutination, standard tube agglutination, 2-mer-captoethanol, rivanol, complement fixation and card tests. Young animals had infection and reactor rates nearly as high as the older animals indicating most were infected at a relative early age. Results suggest that this species may transmit brucellosis when living with domestic animals. This is the first report of B. suis biovar 1 from collared peccaries in Venezuela. PMID:1920669

  20. 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.

  1. 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

  2. Research in seismology and earthquake engineering in Venezuela

    USGS Publications Warehouse

    Urbina, L.; Grases, J.

    1983-01-01

    After the July 29, 1967, damaging earthquake (with a moderate magnitude of 6.3) caused widespread damage to the northern coastal area of Venezuela and to the Caracas Valley, the Venezuelan Government decided to establish a Presidential Earthquake Commission. This commission undertook the task of coordinating the efforts to study the after-effects of the earthquake. The July 1967 earthquake claimed numerous lives and caused extensive damage to the capital of Venezuela. In 1968, the U.S Geological Survey conducted a seismological field study in the northern coastal area and in the Caracas Valley of Venezuela. the objective was to study the area that sustained severe, moderate, and no damage to structures. A reported entitled Ground Amplification Studies in Earthquake Damage Areas: The Caracas Earthquake of 1967 documented, for the first time, short-period seismic wave ground-motion amplifications in the Caracas Valley. Figure 1 shows the area of severe damage in the Los Palos Grantes suburb and the correlation with depth of alluvium and the arabic numbers denote the ground amplification factor at each site in the area. the Venezuelan Government initiated many programs to study in detail the damage sustained and to investigate the ongoing construction practices. These actions motivated professionals in the academic, private, and Government sectors to develops further capabilities and self-sufficiency in the fields of engineering and seismology. Allocation of funds was made to assist in training professionals and technicians and in developing new seismological stations and new programs at the national level in earthquake engineering and seismology. A brief description of the ongoing programs in Venezuela is listed below. these programs are being performed by FUNVISIS and by other national organizations listed at the end of this article.   

  3. Evidence that active transmission of porcine cysticercosis occurs in Venezuela.

    PubMed

    Cortez Alcobedes, Maria M; Boggio, Gonzalo; Guerra, Ma de Lourdes; de Gavidia, Magda Rodríguez; Rojas Reyes, Glenda C; Ferrer, Elizabeth; Lares, Maria; Alviarez, Yenny; Harrison, Leslie J S; Parkhouse, R Michael E

    2010-03-01

    There is a paucity of quantitative data on the status of porcine cysticercosis in Venezuela, information which is essential for understanding the level of disease transmission. This study was, therefore, conducted in a typical small rural community in Yaracuy State, Venezuela, where previous cases of human Taenia solium taeniasis/cysticercosis had been reported and where the free-ranging pig management practices and the lack of rudimentary sanitary facilities indicated an obvious risk for transmission of the disease. Serum samples from 52 village pigs were screened by enzyme-linked immunosorbent assays for anti-cysticercal antibodies (Ab-ELISA), using T. solium cyst fluid as the antigen and the HP10, monoclonal antibody-based, antigen trapping ELISA for parasite antigen (HP10 Ag-ELISA). Significantly, a high proportion of the animals (65.4% for the Ab-ELISA and 42.3% for the HP10 Ag-ELISA) were sero-positive. Five of the pigs, which were selected on that basis of positive tongue palpation, were killed for autopsy, and large numbers of viable cysticerci were found in the carcases. This unequivocal documentation of porcine cysticercosis in Venezuelan pigs presents clear evidence that T. solium is actively transmitted in Venezuela. Further detailed studies and implementation of appropriate control measures are therefore indicated. PMID:19779843

  4. Egalitarian policies and social determinants of health in Bolivarian Venezuela.

    PubMed

    Muntaner, Caries; Benach, Joan; Páez Victor, María; Ng, Edwin; Chung, Haejoo

    2013-01-01

    In 1999, newly-elected Venezuelan President Hugo Chávez initiated a far-reaching social movement as part of a political project known as the Bolivarian Revolution. Inspired by the democratic ideologies of Simón Bolívar, this movement was committed to reducing intractable inequalities that defined Venezuela's Fourth Republic (1958-1998). Given the ambitious scope of these reforms, Venezuela serves as an instructive example to understand the political context of social inequalities and population health. In this article, we provide a brief overview of the impact of egalitarian policies in Venezuela, stressing: (a) the socialist reforms and social class changes initiated by the Bolivarian Movement; (b) the impact of these reforms and changes on poverty and social determinants of health; (c) the sustainability of economic growth to continue pro-poor policies; and (d) the implications of egalitarian policies for other Latin American countries. The significance and implications of Chávez's achievements are now further underscored given his recent passing, leading one to ask whether political support for Bolivarianism will continue without its revolutionary leader. PMID:24066420

  5. Paleogeographic maps, Maturin basin of east Venezuela and Trinidad

    SciTech Connect

    Rohr, G.M.

    1990-05-01

    The northern margin of the Maturin basin of east Venezuela and Trinidad is part of the Caribbean-South American plate-boundary zone, and deformation within the zone reflects relative motions of these two plates. Stratigraphic sections within this zone do not record sedimentation at a fixed site but rather the different paleogeographic locations occupied by a piece of lithosphere as it migrated through space and time. This paper presents a method of restoring stratigraphic control to its site of deposition. The method assumes a constant rate of 2 cm/yr of relative eastward motion for the Caribbean plate in the vicinity of Trinidad and a uniform distribution of shear among numerous wrench faults within the boundary zone. A compressional component is independently derived by restoring a north-northeast-south-southeast cross section through Trinidad. Lithostratigraphic reference sections from Venezuela and Trinidad are reinterpreted as a paleoshelf edge which has undergone more than 90{degree} of clockwise rotation since the middle Eocene. The buried thrust front found productive in Venezuela at El Furrial is traced eastward across Trinidad and into the offshore. Restored paleogeographic maps are presented for middle Pliocene (3 m.y.); middle Miocene (14 m.y.); the Oligocene-Miocene boundary (22 m.y.) and middle Eocene (45 m.y.).

  6. 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).

  7. 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.

  8. 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.

  9. 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

  10. 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…

  11. 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…

  12. 78 FR 49471 - Ferrosilicon From the Russian Federation and Venezuela: Initiation of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ..., Petitioners submitted a foreign research report with respect to the Venezuela petition.\\2\\ On July 24, 2013... the foreign market researcher who authored the Foreign Research Report.\\3\\ On August 5, 2013... Venezuela,'' filed on July 19, 2013 (``Petitions''). \\2\\ See Petitioners' Venezuelan Foreign Research...

  13. 78 FR 4437 - Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To Conduct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... of institution (77 FR 59970, October 1, 2012) was adequate and that the respondent interested party... COMMISSION Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To Conduct... duty orders on silicomanganese from India, Kazakhstan, and Venezuela would be likely to lead...

  14. 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...

  15. 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.

  16. [Microbiological quality of pasteurized milk creams manufactured in Venezuela].

    PubMed

    Szwarcbort de Tamsut, L; García, C E

    1999-03-01

    A total of 100 samples of pasteurized milk creams produced by eleven (11) dairy milk industries were analyzed for the presence of microoganisms. The dairy milk industries were distributed along different places of Venezuela. The samples were analyzed for the presence of mesophilic aerobic bacteria, psychotropic bacteria, Staphylococcus aureus, coliformes, molds and yeasts 75% of the analyzed samples did not reach the international standards for aerobic mesophilic bacteria, similarly, 95% for Staphylococcus aureus, 91% for coliformes and 58% for molds and yeasts, so pathogenic enterobacteria we have found: Salmonella Typhimurium, Shigella sonnei and Escherichia coli enteropathogenic. PMID:10412511

  17. 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.

  18. [Mycobacterium tuberculosis: spoligotypes in the Carabobo state, Venezuela].

    PubMed

    Sequera C, Mónica; Delgado S, Víctor; Araque M, Wolfan; Torrealba O, Mariela; Núñez M, Raimunda; Da Mata J, Omaira; Abadía P, Edgar; Takiff, Howard; De Waard, Jacobus

    2008-10-01

    In order to study the genetic variability of Mycobacterium tuberculosis circulating in the Carabobo State at Venezuela, 317 strains of M. tuberculosis isolated from patients living in different health districts whose acid fast smears were positive, were included. Each strain was characterized by spoligotyping and the pattern compared with the national and worldwide SpolDB4.0 databases; 220 isolates (69.4%) were grouped in 24 clusters, being LAM the most common family (34%). In contrast to other Venezuelan regions, the most common Carabobo spoligotype was number 605, with 46 isolates (14.5%). In addition, there were 97 (30.6%) orphan spoligotypes, 19 of which are found in SpolDB4.0, and 78 non described. Co-infection with human immunodeficiency virus was detected in 11 patients (3.5%). These results show high genotypic variability of M. tuberculosis in the region, contributing with new information for a better understanding of tuberculosis transmission in Venezuela. PMID:18949149

  19. 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

  20. 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.

  1. The periodicity of Plasmodium vivax and Plasmodium falciparum in Venezuela.

    PubMed

    Grillet, María-Eugenia; El Souki, Mayida; Laguna, Francisco; León, José Rafael

    2014-01-01

    We investigated the periodicity of Plasmodium vivax and P. falciparum incidence in time-series of malaria data (1990-2010) from three endemic regions in Venezuela. In particular, we determined whether disease epidemics were related to local climate variability and regional climate anomalies such as the El Niño Southern Oscillation (ENSO). Malaria periodicity was found to exhibit unique features in each studied region. Significant multi-annual cycles of 2- to about 6-year periods were identified. The inter-annual variability of malaria cases was coherent with that of SSTs (ENSO), mainly at temporal scales within the 3-6 year periods. Additionally, malaria cases were intensified approximately 1 year after an El Niño event, a pattern that highlights the role of climate inter-annual variability in the epidemic patterns. Rainfall mediated the effect of ENSO on malaria locally. Particularly, rains from the last phase of the season had a critical role in the temporal dynamics of Plasmodium. The malaria-climate relationship was complex and transient, varying in strength with the region and species. By identifying temporal cycles of malaria we have made a first step in predicting high-risk years in Venezuela. Our findings emphasize the importance of analyzing high-resolution spatial-temporal data to better understand malaria transmission dynamics. PMID:24149288

  2. Renal diseases in children in Venezuela, South America.

    PubMed

    Orta-Sibu, Nelson; Lopez, Michelle; Moriyon, Juan C; Chavez, Juan B

    2002-07-01

    The present study reports epidemiological data on renal disorders in children in Venezuela. Information was obtained from 14 centers for the period January through December 1998. A total of 3,624 patients were evaluated as either a first outpatient consultation or as a first hospital admission. Nearly 70% of the patients could be grouped in one of the following categories: (1) urinary tract infections (32%), with detection of abnormalities of the urinary tract in 25%, (2) metabolic disorders (28%), mainly idiopathic hypercalciuria and hyperuricosuria, (3) glomerulonephritis (9.5%). The other 30% corresponded to urolithiasis 7%; renal tubular acidosis 5.6%; nephrotic syndrome 4.5%; primary hematuria 4.2%; acute renal failure 2.8% (43% were secondary to acute dehydration, 15% to birth asphyxia, 14% to septicemia, and 23% to multiple factors); chronic renal failure 1.6% (secondary to glomerulopathies, predominantly focal glomerulosclerosis, structural abnormalities of the urinary tract, hereditary disorders, and renal hypoplasia/dysplasia); miscellaneous diseases 4.8%. Hence, the spectrum of renal disorders in Venezuela is wide, sharing similarities with countries of both the developed and developing world. These data will hopefully contribute to the development of national healthcare policies appropriate to the epidemiology of the country. PMID:12172777

  3. Geographical distribution of Trypanosoma cruzi genotypes in Venezuela.

    PubMed

    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

  4. Genetic characterization of rabies field isolates from Venezuela.

    PubMed Central

    de Mattos, C A; de Mattos, C C; Smith, J S; Miller, E T; Papo, S; Utrera, A; Osburn, B I

    1996-01-01

    Twenty samples from cases of rabies in humans and domestic animals diagnosed in Venezuela between 1990 and 1994 and one sample from a vampire bat collected in 1976 were characterized by reactivity to monoclonal antibodies against the viral nucleoprotein and by patterns of nucleotide substitution in the nucleoprotein gene. Three antigenic variants were found: 1, 3, and 5. Antigenic variant 1 included all samples from dogs and humans infected by contact with rabid dogs. Unique substitutions permitted identification of two separate outbreaks of dog rabies in the Maracaibo Depression and Los Llanos region and in the Andean region of Venezuela. Samples from the vampire bat and two head of cattle were characterized as antigenic variant 3 and showed a nucleotide sequence homology of 96 to 98% to each other and to samples of vampire bat-associated rabies throughout Latin America. Ten of the remaining 12 samples were characterized as antigenic variant 5. Genetic studies indicated that 11 of these samples formed a highly homologous and distinctive group but were closely related to samples of vampire bat-associated rabies. The 12th sample of variant 5 (from a cat) showed only 78 to 80% genetic homology to samples of rabies associated with vampire bats. The application of antigenic and genetic typing to rabies surveillance in Latin America is essential to improve control programs. Recognition of the source of outbreaks of dog rabies and identification of wildlife species maintaining sylvatic cycles of rabies transmission permit better utilization of public health resources. PMID:8735118

  5. 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)

  6. 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)

  7. 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.

  8. 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...

  9. 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

  10. Overcoming Squeezing in the Yacambú-Quibor Tunnel, Venezuela

    NASA Astrophysics Data System (ADS)

    Hoek, E.; Guevara, R.

    2009-04-01

    The 5 m diameter 23.3 km long Yacambú-Quibor tunnel is designed to carry water through the Andes from the Yacambú dam in the wet tropical Orinoco basin to the semi-arid but fertile Quibor basin in western Venezuela. The tunnel is excavated in silicified and graphitic phyllites at depths of up to 1270 m below surface and extreme squeezing problems have been encountered. Construction involved 8 contracts extending over 32 years with breakthrough being achieved in July 2008. Several excavation methods and various lining designs were used over the years until the adoption of yielding support permitted the Owner and the Contractor to agree that only a circular section would be used and emphasis was placed on developing a routine construction procedure, irrespective of the rock conditions encountered at the face. This paper describes some of the rock engineering issues that were faced during the construction of this tunnel.

  11. Embodying racism: race, rhinoplasty, and self-esteem in Venezuela.

    PubMed

    Gulbas, Lauren E

    2013-03-01

    In this article, I examine how race motivates women's decisions to undergo aesthetic rhinoplasty in Caracas, Venezuela. Through a combination of cultural domain analysis and thematic analysis of qualitative interviews, I explore how the preference for whiteness and associated facial features dovetail with the aesthetic ideals promoted by cosmetic surgeons. Rhinoplasty is offered by physicians and interpreted by patients as a resolution to body dissatisfaction and low self-esteem. The clinical ethos of objectivity established by cosmetic surgeons fails to acknowledge how perceptions of the self and body are strongly tied to racial marginalization: patients' efforts to alter the nose reveal attempts to change not only how the body looks, but how it is lived. As a result, cosmetic surgery only acts as a stop-gap measure to heighten one's self-esteem and body image. PMID:23349127

  12. 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.

  13. 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.

  14. Potential options to reduce GHG emissions in Venezuela

    SciTech Connect

    Pereira, N.; Bonduki, Y.; Perdomo, M.

    1996-12-31

    The Government of Venezuela ratified the United Nations Framework Convention on Climate Change (UNFCCC) in December, 1994. The Convention requires all parties to develop and publish national inventories of anthropogenic greenhouse gas emissions (GHG) as well as national plans to reduce or control emissions, taking into account their common but differentiated responsibilities and their specific national and regional development priorities, objectives, and circumstances. Within this context, the Ministry of Environment and Renewable Natural Resources and the Ministry of Energy and Mines developed the `Venezuelan Case-Study to Address Climate Change`. The study was initiated in October 1993, with the financial and technical assistance of the Government of United States, through the U.S. Country Studies Program (USCSP), and the Global Environment Facility (GEF), through the United Nations Environment Programme (UNEP).

  15. 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.

  16. 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. 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. 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. However, there were increases in case number and mortality during epidemic years, especially among children. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. 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

  5. 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

  6. 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

  7. Fluorescence Time-lapse Imaging of the Complete S. venezuelae Life Cycle Using a Microfluidic Device.

    PubMed

    Schlimpert, Susan; Flärdh, Klas; Buttner, Mark

    2016-01-01

    Live-cell imaging of biological processes at the single cell level has been instrumental to our current understanding of the subcellular organization of bacterial cells. However, the application of time-lapse microscopy to study the cell biological processes underpinning development in the sporulating filamentous bacteria Streptomyces has been hampered by technical difficulties. Here we present a protocol to overcome these limitations by growing the new model species, Streptomyces venezuelae, in a commercially available microfluidic device which is connected to an inverted fluorescence widefield microscope. Unlike the classical model species, Streptomyces coelicolor, S. venezuelae sporulates in liquid, allowing the application of microfluidic growth chambers to cultivate and microscopically monitor the cellular development and differentiation of S. venezuelae over long time periods. In addition to monitoring morphological changes, the spatio-temporal distribution of fluorescently labeled target proteins can also be visualized by time-lapse microscopy. Moreover, the microfluidic platform offers the experimental flexibility to exchange the culture medium, which is used in the detailed protocol to stimulate sporulation of S. venezuelae in the microfluidic chamber. Images of the entire S. venezuelae life cycle are acquired at specific intervals and processed in the open-source software Fiji to produce movies of the recorded time-series. PMID:26967231

  8. Sequence stratigraphy of the Maturin sub-basin (Eastern Venezuela)

    SciTech Connect

    Gonzales, G.; Mata, S.; Santiago, N.

    1996-08-01

    The prolific Eastern Venezuela Basin has an area of about 160,000 km{sup 2} and is bounded by the Pilar Fault to the North, the Guayana Shield to the South, the Baul Arch to the West and beyond the Orinoco Delta to the East. Sequence analysis of three N-S and one W-E regional transects covered by over one thousand km of seismic lines and sedimentological, biostratigraphic and electrofacies studies of 80 wells allowed the definition of the sequence stratigraphic column of the basin. Seven major unconformity bounded depositional sequences were defined from Barremian to Recent, three in the Cretaceous and four in the Tertiary. Twenty-one third-order cycles were recognized in the Tejas B supercycle (Upper Oligocene-Recent). This cycle correlates very well with the Gulf of Mexico and Global chronostratigraphic charts. In the proximal, southern area, each sequence shows transgressive sandstones in its lower section and regressive ones in the upper part, separated by claystones that include a maximum flooding surface. In the distal area, fine marine sediments predominate with local turbidities. Some electrical markers and planktonic fossils are traceable over long distances. Regional transacts show two distinct structural zones: tensional to the South and compressional to the North. The best petroleum reservoirs occur in Tertiary and to a lesser extent in Cretaceous sequences. In this basin occurs the largest oil accumulation of the world (Orinoco), as well as several giant oil fields.

  9. An obstetrics and gynaecology graduate residency programme in Venezuela.

    PubMed Central

    Faneite, P.

    1998-01-01

    We present our experience on the design and development of a gynaecology and obstetrics graduate residency programme, developed in the Department of Obstetrics and Gynecology at the Dr Adolfo Prince Lara Hospital, Puerto Cabello, Venezuela, in which medical specialists and residents participate synergistically. From January to September 1993, curricular activities were planned and students selected. The programme started in October 1993, with six residents for a three-year programme. Courses were given by medical specialists from the Department. In addition to a Programme Coordinator, there is also a Residents' Coordinator, appointed for a two-month term of office; specific functions were assigned for residents occupying this position. All the programmed activities for three years were accomplished, including lectures and rotations, with an important record of surgical interventions. In our grade system, residents got an average of 18 over a maximum of 20 points. Residents also participated as speakers in workshops, special courses and national medicinal meetings, in which they presented a total of nine papers. Activities were evaluated bimonthly in meetings with students and each semester by the Graduate Committee. The first class graduated in September 1996. Results suggest that resident participation in graduate programmes is an important part of their education. PMID:9538482

  10. Geological study of Guafita field reservoirs, Apure basin, southwestern Venezuela

    SciTech Connect

    Moya, E.; Abud, J.; Hernandez, J.

    1989-03-01

    The medium-grade oil reservoirs of the Guafita field, Apure basin, southwestern Venezuela, represent the northeastern extension of the La Yuca-Cano Limon fields of Colombia. A detailed integrated reservoir study is being carried out in Guafita in order to define the geological model and to improve its development plan. The stratigraphic sequence of interest in the southern block of the Guafita field contains approximately 600 ft of sediments of Cretaceous and Oligocene-Miocene ages (Quevedo Member of the Navay and Guafita Formations, respectively). Fifteen prospective intervals, with approximately 150 ft of net oil sand, have been defined within this sequence by detailed correlation in the Colombian fields and four have been defined in the Quevedo Member. Lower delta-plain and delta-front depositional environments have been recognized from core studies in the Tertiary sediments. A combination of both structural and stratigraphic traps controls the hydrocarbon accumulations in the Guafita field, and at least two sealing shale regional markers have been defined. As a preliminary result of the approach of defining reservoir geometry and mapping each major sand body separately, the proven reserves of the Guafita field will decrease by approximately 12%. The possibility of fluid communication with the Colombian fields through the small-displacement riddle faults was established by means of juxtaposition of sand bodies.

  11. Pros and cons of power combined cycle in Venezuela

    SciTech Connect

    Alvarez, C.; Hernandez, S.

    1997-09-01

    In Venezuela combined cycle power has not been economically attractive to electric utility companies, mainly due to the very low price of natural gas. Savings in cost of natural gas due to a higher efficiency, characteristic of this type of cycle, does not compensate additional investments required to close the simple cycle (heat recovery steam generator (HRSG) and steam turbine island). Low gas prices have contributed to create a situation characterized by investors` reluctance to commit capital in gas pipe lines and associated equipment. The Government is taking measures to improve economics. Recently (January 1, 1997), the Ministry of Energy and Mines raised the price of natural gas, and established a formula to tie its price to the exchange rate variation (dollar/bolivar) in an intent to stimulate investments in this sector. This is considered a good beginning after a price freeze for about three years. Another measure that has been announced is the implementation of a corporate policy of outsourcing to build new gas facilities such as pipe lines and measuring and regulation stations. Under these new circumstances, it seems that combined cycle will play an important role in the power sector. In fact, some power generation projects are considering building new plants using this technology. An economical comparative study is presented between simple and combined cycles power plant. Screening curves are showed with a gas price forecast based on the government decree recently issued, as a function of plant capacity factor.

  12. Hemosporidian parasites in forest birds from Venezuela: genetic lineage analyses.

    PubMed

    Mijares, Alfredo; Rosales, Romel; Silva-Iturriza, Adriana

    2012-09-01

    Avian hemosporidian parasites of the genera Haemoproteus, Plasmodium, and Leucocytozoon are transmitted by different dipteran vectors. In the present work, we looked for the presence of these parasites in 47 birds from 12 families, which were sampled in the migratory corridor Paso de Portachuelo, located at the Henri Pittier National Park, Venezuela. The presence of the parasites was evidenced by amplification of a region of 471 bp of their cytochrome b gene. This region of the marker presents enough polymorphism to identify most of the mitochondrial lineages. Therefore, the obtained amplicons were sequenced, not only to identify the genus of the parasites sampled, but also to analyze their genetic diversity in the study area. The overall parasite prevalence was low (11%). We reported, for the first time, Plasmodium in birds of the species Formicarius analis and Chamaeza campanisona (Formicariidae) and Haemoproteus in Geotrygon linearis (Columbidae). A phylogenetic tree was generated using the Haemoproteus, Plasmodium, and Leucocytozoon sequences obtained in this study, together with representative sequences from previous studies. The highest genetic diversities between the two Haemoproteus lineages (11.70%) and among the three Plasmodium lineages (7.86%) found in this study are also similar to those found when lineages reported in the literature were used. These results indicate that in the migratory corridor Paso de Portachuleo, representative parasite lineages are found, making this location an attractive location for future studies. PMID:23050478

  13. 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.

  14. 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

  15. 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.

  16. [Balantidiasis in a rural community from Bolivar State, Venezuela].

    PubMed

    Devera, R; Requena, I; Velásquez, V; Castillo, H; Guevara, R; De Sousa, M; Marín, C; Silva, M

    1999-01-01

    Balantidium coli is the etiologic agent of balantidiasis, an infrequent zoonose of worldwide distribution. The objective of the present study was to determine the clinical and epidemiological aspects of balantidiasis in a rural community in the Bolivar State in Venezuela. Fifty persons and 12 pigs were evaluated. Fecal samples were analyzed by direct examination and by the methods of Faust and Willis. The global rate of intestinal parasitoses detected was 88.0% for the human population and 83.3% for the pigs. The prevalence of human and porcine balantidiais was 12.0% (6/50) and 33.3% (4/12), respectively. The disease was only detected in children, all of them with multiple parasites and with clinical manifestations. Deficient environmental sanitation, absence of basic services in the dwellings, low socioeconomic level, and the presence of pigs infected with B. coli are the factors that explain and maintain the conditions favorable to the transmission of balantidiasis in the population studied. PMID:10488584

  17. 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.

  18. Meningoencephalitis by Naegleria fowleri: epidemiological study in Anzoategui state, Venezuela.

    PubMed

    Cermeño, Julman R; Hernández, Isabel; El Yasin, Helal; Tinedo, Rubén; Sánchez, Raúl; Pérez, Gladys; Gravano, Rosalía; Ruiz, Aida

    2006-01-01

    A case of primary amoebic meningoencephalitis produced by Naegleria fowleri was diagnosed in the Independencia county of Anzoategui State, Venezuela. This case motivated the realization of the present epidemiological study with the aim of identifying free-living amoebae in this area. Representative water samples were taken and physicochemical and microbiologic analyses were carried out. Trophozoites and cysts of Naegleria spp, were detected in 44.4% (n=4). An excellent concordance was found among the observations of free-living amoebae in smears and those of monoxenic cultures in non-nourishing agar with Klebsiella pneumoniae (Kappa=1; p= 0.003). A variable load of aerobic mesophils was obtained. Moulds and yeast averages presented 3.0 CFU/ml (SD +/- 2.0) and 102.9 CFU/ml (SD +/- 32.2), respectively. One hundred per cent of the samples presented a most probable number of total and fecal coliforms of 240,000 NMP/100mL. Naegleria spp was present in waters of the Independence county of Anzoategui state, which constitutes a risk for people that use these sources. PMID:16906250

  19. Late Quaternary Environmental History of Lake Valencia, Venezuela

    NASA Astrophysics Data System (ADS)

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

    1981-12-01

    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.

  20. 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.

  1. Cretaceous to Eocene passive margin sedimentation in Northeastern Venezuela

    SciTech Connect

    Erikson, J.P. )

    1993-02-01

    Twenty two palinspastic paleogeographic maps are presented for the Cretaceous to Eocene strata of the Serrania del Interior of northeastern Venezuela. The mapped lithologies, environmental conditions, and evolving depositional systems record [approximately]90 m.y. of dominantly marine sedimentation on the only observable Mesozoic passive margin in the Western Hemisphere. The depositional systems of the passive margin are heterogeneous at lateral (i.e., along-margin) length scales greater than [approximately]40 km. The primary lateral heterogeneity is caused by a major Lower Cretaceous deltaic system that emanated southwest of the Serrania del Interior. All important intervals, such as the laterally variable Aptian-Albian El Cantil platform limestone and the hydrocarbon source rocks of the Upper Cretaceous Querecual and San Antonio formations, are related to probable causal mechanisms and environmental conditions. Stratigraphic events have been interpreted as of either local or regional extent; based on a combination of outcrop sedimentologic analyses and regional depositional systems interpretation. The 3-dimensional distribution of depositional systems and systems tracts reveals 4-6 regional sequence boundaries separated by 4-20 m.y. Subsidence analyses support the facies interpretation of a passive margin by showing continuous, thermally dominated subsidence during the Cretaceous to Eocene interval. Subsidence and accumulation rates increased and facies changed significantly in the Oligocene, indicating the end of passive margin sedimentation and the initiation of foredeep subsidence and accumulation associated with overthrusting the eastward-advancing Caribbean Plate.

  2. 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

  3. Diel variation of nitrogen fixation in Lake Valencia, Venezuela

    SciTech Connect

    Levine, S.N.; Lewis, W.M. Jr.

    1984-07-01

    During 1981 the authors examined the diel variations of nitrogen fixation in Lake Valencia, Venezuela. Four species of heterocyst-bearing blue-green algae were common but subdominant in the phytoplankton. In samples taken from and incubated at 0.5 m, the rate of nitrogen fixation per unit volume of water was lowest at night, increased from dawn until early afternoon, and then diminished between late afternoon and the first hour of darkness. This pattern was caused partly by diel changes in light intensity and partly by diel migrations of heterocystous blue-green algae. The heterocyst-specific nitrogen fixation rates at 0.5 m were much less variable than the nitrogen fixation rates per unit volume of water. Heterocyst-specific rates rose rapidly in early morning and fell slowly in the evening, but were almost constant over much of the day. Heterocyst-specific nitrogen fixation rates were very close to those predicted by a model based on the light dependency of nitrogen fixation.

  4. 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

  5. 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

  6. First report of Cowpea mild mottle Carlavirus on yardlong bean (Vigna unguiculata subsp. sesquipedalis) in Venezuela.

    PubMed

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

    2012-12-01

    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

  7. 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.

  8. 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.

  9. Coal bed methane potential in Venezuela-The forgotten resource

    SciTech Connect

    Vasquez-Herrera, A.R.; Bereskin, S.R.; McLennan, J.D.

    1996-08-01

    In nations already possessing riches of hydrocarbons situated in conventional reservoirs, evaluation of coal-bearing sequences for potential gas is logically delayed or ignored. Nonetheless, Venezuelan coals have long been recognized as stratigraphically associated with oil accumulations, but because coalbed methane (CBM) is a relatively new worldwide phenomenon, CBM potential has not been widely assessed in the country. Two general areas contain vast accumulations of coal for potential CBM activity: (1) the Maracaibo basin, containing the Guasare (northwest), Lobatera-Santo Domingo (southwest) and Urumaco (northeast) districts; and (2) the Oficina basin in eastern Venezuela possessing abundant accumulations related to the Faja Petrolifera de Orinoco (Orinoco Oil Belt). In both basins, high volatile bituminous and lignitic coals of mostly Oligo-Miocene age are abundantly found. Older coals are also present especially in the Maracaibo area. Two factors represent powerful incentives for CBM exploitation: addition of known reserves for economic considerations, and aid in bringing heavy crude oil to the surface by additional gas lift and oil viscosity reduction. Other favorable factors important for CBM methodology include: (1) abundant coals lying above known conventional reservoir targets; (2).6 - 1% vitrinite reflectance measurements in the Orinoco Oil Belt; (3) many coals occurring above 1500 m; (4) documented mine explosions especially in the 1920s and 1930s; (5) a strong tectonic overprint to perhaps add shear fractures to already cleated coals; (6) individual coal thickness up to 12 m with averages in the .8 m range; and (7) gas shows while drilling coal-rich intervals.

  10. 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.

  11. Resurrection Symphony: "El Sistema" as Ideology in Venezuela and Los Angeles

    ERIC Educational Resources Information Center

    Fink, Robert

    2016-01-01

    The explosive growth of Venezuela's "El Sistema" is rewriting the agenda of musical education in the West. Many commentators from the world of classical music react to the spectacle of dedicated young colonial musicians playing European masterworks as a kind of "miracle," accepting "Sistema" founder José Antonio…

  12. 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…

  13. 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…

  14. 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…

  15. Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela.

    PubMed

    Vásquez, Carlos; de Moraes, Gilberto J

    2013-05-01

    The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region. PMID:23065034

  16. 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... Automobile, Aerospace and Agricultural Implement Workers of America (``UAW''). \\5\\ See Letter to...

  17. 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…

  18. Rural Development in Venezuela and the Guianas: A Bibliography. Training and Methods Series Number 20.

    ERIC Educational Resources Information Center

    Anderson, Teresa, Comp.; And Others

    The bibliography cites 930 materials dealing with Venezuela and the Guianas. Published between 1949 and 1972, the materials are found in the Land Tenure Center Library at the University of Wisconsin. Topics covered are: agriculture, agrarian reform, economic affairs, economic cooperation, human resources, American Indians, industry, law, money,…

  19. 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…

  20. 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…

  1. 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

  2. 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…

  3. 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…

  4. 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.

  5. Resurrection Symphony: "El Sistema" as Ideology in Venezuela and Los Angeles

    ERIC Educational Resources Information Center

    Fink, Robert

    2016-01-01

    The explosive growth of Venezuela's "El Sistema" is rewriting the agenda of musical education in the West. Many commentators from the world of classical music react to the spectacle of dedicated young colonial musicians playing European masterworks as a kind of "miracle," accepting "Sistema" founder José Antonio…

  6. 77 FR 59970 - Silicomanganese From India, Kazakhstan, and Venezuela; Institution of Five-Year Reviews...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... silicomanganese from India, Kazakhstan, and Venezuela (73 FR 841, January 4, 2008). The Commission is now... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE... amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this request for information is required if...

  7. 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

    ...On October 1, 2012, the Department of Commerce (``Department'') initiated the second sunset reviews of the antidumping duty orders on silicomanganese from India, Kazakhstan, and Venezuela. The Department finds that revocation of these antidumping duty orders would be likely to lead to continuation or recurrence of dumping at the rates identified in the ``Final Results of Reviews'' section of......

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

    NASA Astrophysics Data System (ADS)

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

    2007-10-01

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

  9. 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

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  14. 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

  15. 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

  16. Activity of Lutzomyia pseudolongipalpis and L. longipalpis s.l. (Diptera: Psychodidae) in Venezuela.

    PubMed

    Feliciangeli, M D; Arrivillaga, J C; Bravo, A; Arias, F

    2004-09-01

    The nocturnal activity of the phlebotomine sandfly Lutzomyia pseudolongipalpis and two populations of L. longipalpis s.l. from different American visceral leishmaniasis foci in Venezuela was studied using collection bottle rotator traps. The activity of L. pseudolongipalpis from Lara State was continuous throughout the night, while that of L. longipalpis s.l. from El Layero, Guárico State and from Santa Ana del Valle, Margarita Island, was greatest before 23:00 h. The activity of sandflies of both populations and sexes steadily decreased thereafter. These different patterns seem to correlate with genetic data that indicate the presence in Venezuela of at least two sibling species in the L. longipalpis complex. The advantages of the bottle rotator trap for this type of study are discussed. PMID:15490751

  17. 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.

  18. 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…

  19. 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.

  20. 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

  1. 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.

  2. [Direct genetic manipulation and criminal code in Venezuela: absolute criminal law void?].

    PubMed

    Cermeño Zambrano, Fernando G De J

    2002-01-01

    The judicial regulation of genetic biotechnology applied to the human genome is of big relevance currently in Venezuela due to the drafting of an innovative bioethical law in the country's parliament. This article will highlight the constitutional normative of Venezuela's 1999 Constitution regarding this subject, as it establishes the framework from which this matter will be legally regulated. The approach this article makes towards the genetic biotechnology applied to the human genome is made taking into account the Venezuelan penal law and by highlighting the violent genetic manipulations that have criminal relevance. The genetic biotechnology applied to the human genome has another important relevance as a consequence of the reformulation of the Venezuelan Penal Code discussed by the country's National Assembly. Therefore, a concise study of the country's penal code will be made in this article to better understand what judicial-penal properties have been protected by the Venezuelan penal legislation. This last step will enable us to identify the penal tools Venezuela counts on to face direct genetic manipulations. We will equally indicate the existing punitive loophole and that should be covered by the penal legislator. In conclusion, this essay concerns criminal policy, referred to the direct genetic manipulations on the human genome that haven't been typified in Venezuelan law, thus discovering a genetic biotechnology paradise. PMID:12379984

  3. 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.

  4. 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

  5. Epizootics of yellow fever in Venezuela (2004-2005): an emerging zoonotic disease.

    PubMed

    Rifakis, Pedro M; Benitez, Jesus A; De-la-Paz-Pineda, Jose; Rodriguez-Morales, Alfonso J

    2006-10-01

    Epidemics and epizootics of yellow fever (YF) have been occurring in the border area of eastern Colombia and western Venezuela since 2003; for this reason many epidemiological control measures were adopted by the Ministry of Health (MOH) trying to prevent their spreading. These activities included monkey deaths surveillance as well as immunization of susceptible individuals with YF vaccine. In this setting, we analyzed epidemiological and epizootical issues related to YF in Venezuela during 2004-2005. In this period, YF epizootics occurred initially without geographical links to the 2003 outbreaks (which occurred at the Southern Maracaibo lake epizootic wave), but in relation with the Guayana epizootic wave; beginning in Monagas state and then affecting Anzoátegui, Guárico, and Sucre states. Just months later, Apure was also affected. Mérida and Táchira also report epizootics for the end of 2004. This year concluded with 15 human deaths due to YF and more than 100 howler monkey deaths. In the same year, 715 suspected cases were investigated confirming YF in 0.7% of them. For these reasons, between 2002 and 2004, Venezuela's MOH has vaccinated approximately 1.9 million people in areas considered to be enzootic. The country's goal for 2006 is to have 7 million people residing in high-risk cities and towns vaccinated, and in this way, preventing and controlling this emerging zoonotic disease. PMID:17135494

  6. Distribution of Lymnaeidae (Mollusca: Pulmonata), intermediate snail hosts of Fasciola hepatica in Venezuela.

    PubMed

    Pointier, J P; Noya, O; Alarcón de Noya, B; Théron, A

    2009-08-01

    An extensive malacological survey was carried out between 2005-2009 in order to clarify the exact number of lymnaeid species which may be intermediate hosts of Fasciola hepatica in Venezuela. Four species were discovered during this survey, including two local species: Lymnaea cubensis and Lymnaea cousini and two exotic species: Lymnaea truncatula and Lymnaea columella. The most common local species was L. cubensis which was found at 16 out of the 298 sampling sites. This species has a large distribution area throughout the Northern part of Venezuela and was encountered from sea level to an altitude of 1,802 m in state of Trujillo. The second local species L. cousini was collected at only two sites of the Andean Region at altitudes of 3,550 m and 4,040 m, respectively. The European L. truncatula was found at 24 sites all located in the states of Mérida and Táchira at an altitude varying between 1,540-4,000 m. The respective distribution areas of L. cubensis and L. truncatula do not appear to overlap, but more detailed malacological surveys are needed. The fourth lymnaeid species, L. columella was collected in a canal from Mérida at an altitude of 1,929 m and in an irrigation canal from the state of Guárico, at an altitude of 63 m. The role of these four lymnaeid species in the transmission of fascioliasis in Venezuela is discussed. PMID:19820844

  7. [Selenium content in the blood cattle from Venezuela. I. Central and Portugueste zones].

    PubMed

    Otaiza, E R; Valeri, H; Cumare, V

    1977-06-01

    Whole blood concentrations of selenium were determined in 776 dairy cows and calves from 28 farms located in three States (Aragua, Carabobo and Guárico) of the central zone of Venezuela and in Portuguesa State. Selenium levels largely varied according to both the geographic distribution and animals breed. Cattle from Guárico State showed the lowest average concentration (0.21 ppm) and those from Portuguesa the highest one (0.67 ppm). A group of animals from Turén (a District of Portuguesa State) showed the highest average concentration (1.64 ppm, range 1.02 +/- to 3.24 ppm). Concentrations of this magnitude in animals under grazing conditions could be related to high levels of selenium either in the soil or in the pasture. It is concluded that such animals are localized inaseleniferous zone (Turén). It must be noted that Jaffé et al. (op. cit.) found high levels of selenium in sesame seeds (Sesamum indicum) from this area and in blood and urine samples of children from Villa Bruzual, a little town of Turén. The results of this wok significantly differ from those obtained in other countries (of Europe and North America), where animals are managed under conditions very different from those of the tropical areas like Venezuela. The role this factor is discussed. This is the first report on blood levels in large animals of economical importance in Venezuela. PMID:931500

  8. [Fatty acids profile characterization of white maize hybrids grown in Venezuela].

    PubMed

    Alezones, Jesús; Avila, Manuel; Chassaigne, Alberto; Barrientos, Venancio

    2010-12-01

    In Venezuela, white corn is the most important crop regarding production, harvest area and consumption. One of its main by-products is corn oil, whose positive effect on health caused by the high content of unsaturated fatty acids has been widely recognized. In order to characterize the fatty acids profile of twelve white grained maize hybrids extensively grown in Venezuela, and the effect that divergent localities has on this profile, three semi commercial scale trials where established in Portuguesa, Yaracuy and Guárico states. Proportions of the main fatty acids in the raw oil of the different grain samples were determined using gas chromatography. Significant differences (p < 0,01) between hybrids were found for arachidic, palmitic, stearic, oleic, gadoleic and linoleic acids; non significant differences were found for linolenic acid. Significant differences between localities were found for all the fatty acids evaluated. High and significant correlations between fatty acids content were found; the most important relations were: linoleic-oleic (Rho = -0,98**), arachidic-palmitic (Rho = -0,61**), linoleic-stearic (Rho = -0,61**) and oleic-stearic (Rho = 0,58**). Corn produced in Venezuela presents lower levels of linoleic and higher levels of palmitic, stearic and oleic acids than the levels found in temperate corn. These differences involve significant changes in the nutritional properties of Venezuelan corn oil that should be considered in the development of new cultivars and industrial processes for oil production. PMID:21866691

  9. Heavy metals in sediments, mussels and oysters from Trinidad and Venezuela.

    PubMed

    Astudillol, L Rojas de; Yen, I Chang; Bekele, I

    2005-05-01

    The Gulf of Paria is bordered by both Trinidad and Venezuela, from which various metallic pollutants and other contaminants can originate. The Gulf is still a significant source of fish, crabs and shellfish for human consumption to both countries, where concerns over the quality of this marine environment have been long expressed but never properly addressed. In addition, the circulatory current patterns in the Gulf ensure that contaminants originating from either country are likely to affect both countries eventually. Heavy metals were determined in oysters (Crassostrea rhizophorae and C. virginica), green mussels (Perna viridis) and sediments from the Gulf of Paria. Samples were obtained at four sites in Trinidad and three sites in Venezuela in the Gulf of Paria, in addition to comparative samples collected from three sites on the north coast of Venezuela. Edible tissues of twelve shellfish from each location were blended and aliquots digested with concentrated nitric acid, for extraction of cadmium, chromium, copper, lead, nickel and zinc. The solutions were analysed by flame atomic absorption spectroscopy. Mercury was extracted with a mixture of nitric, hydrochloric and sulphuric acids and determined by cold vapour atomic absorption. Sediments were oven-dried at 60'C, before being similarly extracted. Results showed that mercury in sediments at all sites in Trinidad and Venezuela exceeded NOAA and Canadian sediment quality guidelines, while cadmium, copper, nickel, lead and zinc also exceeded these guidelines at several sites. Heavy metal levels in oysters and green mussels varied widely with location. However, oysters from the Gulf of Paria contained significantly higher mean levels of cadmium, copper, nickel and zinc than those from the north coast of Venezuela, but this difference was not apparent in mussels. Cadmium, mercury and zinc in sediments were significantly correlated with those of mussels, but not of oysters, in which copper and zinc at several sites in the Gulf of Paria exceeded local maximum permissible levels (Cu = 20 microg g(-1) wet wt; Zn = 50 microg g(-1) wet wt) for human consumption. These findings indicate that while mussels may be better biological indicators of heavy metal pollution in sediments than oysters, the latter may provide copper and zinc contamination. Further research is needed to determine the most appropriate biological indicators of heavy metal and other pollutants in the local marine environment and to develop protocols for their use. PMID:17465143

  10. 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

  11. 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.

  12. Cutaneous leishmaniasis due to Leishmania chagasi/Le. infantum in an endemic area of Guarico State, Venezuela.

    PubMed

    De Lima, H; Rodríguez, N; Feliciangeli, M D; Barrios, M A; Sosa, A; Agrela, I; Sánchez, E; Lopez, O

    2009-07-01

    This study reports cutaneous leishmaniasis (CL) caused by Leishmania chagasi/Le. infantum in Venezuela, with some atypical characteristics. Out of 63 cases of CL in the suburbs of Altagracia de Orituco, Guarico State, Venezuela, 30 presented clinical, parasitological, immunological and epidemiological features different from those of the classical CL known in the country. The initial lesion was small and nodular, which, if not treated, might progress to a superficial ulcer. No secondary infection was observed. The identification of the isolates was carried out by molecular techniques. Twelve species of phlebotomine sandflies were caught, the most abundant being Lutzomyia evansi and Lu. longipalpis s.l., known vectors of Le. chagasi/Le. infantum. The existence of Le. chagasi/Le. infantum and its vectors in an endemic area of CL has implications and we suggest that epidemiological studies should be carried out to obtain a clearer picture of the extent of this CL form in Venezuela. PMID:19150102

  13. [Cardiovascular risk: initial estimation in the study cohort "CDC of the Canary Islands in Venezuela"].

    PubMed

    Viso, Miguel; Rodríguez, Zulma; Loreto, Neydys; Fernández, Yolima; Callegari, Carlos; Nicita, Graciela; González, Julio; Cabrera de León, Antonio; Reigosa, Aldo

    2011-12-01

    In Venezuela as in the Canary Islands (Spain), cardiovascular disease is a major cause of morbidity and mortality. The purpose of this research is to estimate the cardiovascular risk in the Canary Islands migrants living in Venezuela and participating in the study cohort "CDC of the Canary Islands in Venezuela". 452 individuals, aged 18 to 93 years (54.9% women), were enrolled between June 2008 and August 2009. A data survey was performed and their weight, height, abdomen and hip circumferences, and blood pressure were measured. After a 12-hour fasting period, a blood sample was obtained for glucose and lipid profile determinations. 40.5% of the subjects were over 65 years of age and 8% corresponded to the younger group (18-30 years). In men, the average age was 57.69 +/- 18.17 years and the body mass index 29.39 +/- 5.71 kg/m2, whereas women were 56.50 +/- 16.91 years and 28.20 +/- 5.57 kg/m2, respectively. The prevalence of metabolic syndrome was 49.1%, overweight and obesity together 75,2%, abdominal obesity 85.4%, diabetes 17.4%, impaired fasting glucose (IFG) 12.2%, elevated blood pressure 52.9%, low HDL-cholesterol 53,8% and elevated serum triglycerides 31%. Among subjects without diabetes or IFG, a third showed a high triglycerides/HDL-cholesterol ratio, indicating insulin resistance. We conclude that the Canarian-Venezuelan community suffers high prevalence of cardiovascular risk factors (obesity, abdominal obesity, dyslipidemia, diabetes). In relation to the current population of the Canary Islands, they show a lower frequency of IFG and a higher frequency of low HDL-cholesterol. In comparison to the Venezuelan population (Zulia), they showed to have lower prevalence of IFG, low HDL cholesterol and elevated triglycerides. PMID:22523842

  14. [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

  15. [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

  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. Microseismicity evidence for subduction of the Caribbean plate beneath the South American Plate in northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    PéRez, Omar J.; Jaimes, Martha A.; Garciacaro, Emilio

    1997-08-01

    Over 1100 microearthquakes with body wave magnitude mb<4 have been located in western Venezuela and the southwestern Caribbean region since the installation in 1980 of the Venezuelan Seismological Array, together with 120 events of mb?4, one of them with surface wave magnitude Ms˜6. This tectonically complex region is part of the boundary between the Caribbean and the South American plates. The main seismically active feature inland in western Venezuela is the northeast striking, 600-km long, 100-km wide, right-lateral strike-slip Boconó fault zone along the Venezuelan Andes. About 80% of the earthquakes located in the entire region in the period 1980-mid-1995 have occurred on this fault zone, at focal depths <20 km. Microearthquake activity at lower rates also occurs northwest of the Venezuelan Andes, both in the continental and Caribbean sea regions. Part of this activity takes place at depths down to ˜150 km. Northwest oriented seismicity depth profiles show the existence of a Benioff zone dipping to the southeast beneath northwestern Venezuela and northern Colombia. This indicates the presence of a northeast striking, southeast dipping subducted slab of the Caribbean plate beneath the South American plate. Hypocentral locations show that the northeastern end of this subduction occurs northwest of the Curaçao-Aruba region, in the vicinity of a northwest trending, right-lateral strike-slip fault zone that joins up with the northeastern end of the Boconó fault zone. This latter place turns out to be the western end of the east-west striking San Sebastián fault along the Venezuelan coast.

  18. 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.

  19. Characterization of l-Digitoxosyl-phenanthroviridin from Streptomyces venezuelae ISP5230.

    PubMed

    Robertson, Andrew W; Martinez-Farina, Camilo F; Syvitski, Raymond T; Jakeman, David L

    2015-08-28

    The jadomycin-derived compound l-digitoxosyl-phenanthroviridin was isolated from fermentations of Streptomyces venezuelae ISP5230 grown in nutrient-deficient media with l-lysine as the sole nitrogen source. Structural elucidation was accomplished using a combination of high-resolution MS, LC-MS/MS, and 1D- and 2D-NMR. The compound was evaluated against the National Cancer Institute (NCI) 60 human tumor cell line screen in both the one-dose and five-dose screens, and cytotoxicity was compared to a small library of jadomycin analogues to probe the structure-activity relationship. PMID:26203536

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. [Outbreak of dengue in San Jose of Guaribe, Venezuela. Preliminary report].

    PubMed

    Caraballo, A; Hernández, J

    1991-01-01

    An outbreak of dengue in the Municipality San José of Guaribe, Guarico State about the middle of September and to beginning October 1990 is reported. A total 97 cases without death and the serologic study in a population sample showed type 2 virus. The quick intervention, the effectiveness of the measures of control, one attention medical opportune and the early serologic diagnostic to contribute of the outbreak control. This is the first description of a dengue outbreak in the Guarico State, Venezuela. PMID:1844971

  6. 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,…

  7. 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.

  8. Quaternary tectonics and present stress tensor of the inverted northern Falcón Basin, northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard M, Franck A.

    2001-02-01

    The Tertiary Falcón Basin in northwestern Venezuela has a privileged position in the geodynamic puzzle of northwestern South America, occurring in a region where several major plates (Caribbean, South America and Nazca) and minor lithospheric blocks (Maracaibo, Bonaire and Western Colombia) are interacting. A combination of good exposures due to aridity and a near-continuous sedimentary record in a now inverted basin helps to unravel the Neogene and Quaternary geodynamic evolution of this region. A neotectonic and microtectonic investigation of the Plio-Quaternary sedimentary rocks of the northern Falcón Basin reveals that this region is subject to a compressive to transpressive regime at present. This regime is characterized by a NNW-SSE oriented maximum horizontal stress, and a ENE-WSW trending intermediate (or minimum) horizontal stress, as is confirmed by focal mechanism solutions. This stress field is in agreement both with the NNE-directed extrusion of the Maracaibo and Bonaire blocks in Western Venezuela, where the Falcón Basin is located, and present-day transpression along the Caribbean-South America plate boundary zone.

  9. Evidence for clonal propagation in natural isolates of Plasmodium falciparum from Venezuela

    PubMed Central

    Urdaneta, Ludmel; Lal, Altaf; Barnabé, Christian; Oury, Bruno; Goldman, Ira; Ayala, Francisco J.; Tibayrenc, Michel

    2001-01-01

    We have analyzed 75 isolates of Plasmodium falciparum, collected in Venezuela during both the dry (November) and rainy (May–July) seasons, with a range of genetic markers including antigen genes and 14 random amplified polymorphic DNA (RAPD) primers. Thirteen P. falciparum stocks from Kenya and four other Plasmodium species are included in the analysis for comparison. Cross-hybridization shows that the 14 RAPD primers reveal 14 separate regions of the parasite's genome. The P. falciparum isolates are a monophyletic clade, significantly different from the other Plasmodium species. We identify three RAPD characters that could be useful as “tags” for rapid species identification. The Venezuelan genotypes fall into two discrete genetic subdivisions associated with either the dry or the rainy season; the isolates collected in the rainy season exhibit greater genetic diversity. There is significant linkage disequilibrium in each seasonal subsample and in the full sample. In contrast, no linkage disequilibrium is detected in the African sample. These results support the hypothesis that the population structure of P. falciparum in Venezuela, but not in Africa, is predominantly clonal. However, the impact of genetic recombination on Venezuelan P. falciparum seems higher than in parasitic species with long-term clonal evolution like Trypanosoma cruzi, the agent of Chagas' disease. The genetic structure of the Venezuelan samples is similar to that of Escherichia coli, a bacterium that propagates clonally, with occasional genetic recombination. PMID:11371616

  10. Serological prevalence of Babesia caballi and Theileria equi in horses of Lara State, Venezuela.

    PubMed

    Mujica, Franklin F; Perrone, Trina; Forlano, María; Coronado, Alfredo; Meléndez, Roy D; Barrios, Nailuj; Alvarez, Rafael; Granda, Fernando

    2011-05-31

    The main objective of this study was to demonstrate the occurrence of equine piroplasmosis (EP) in horses of Lara State, Venezuela, and to correlate it with the factors host's sex and age in order to know the epidemiology of this disease at the Venezuelan Centroccidental Region. Antibody levels to Babesia caballi and Theileria equi were assessed in 360 equine serum samples, collected from 9 municipalities of Lara State, using an ELISA technique with recombinant antigens and monoclonal antibodies (Mabs). Antibodies to B. caballi were found in 254 horses (70.6%), whereas 181 animals (50.3%) were detected as seropositives to T. equi. In addition, 128 samples (35.56%) were seropositives to both hemoparasites. There were no significant differences between the seropositivity to B. caballi and T. equi with the factors sex and age of the horses. These results show that Lara State is an enzootic area for equine piroplasmosis, and are a contribution to a partial knowledge of the dynamic of this disease in Venezuela. PMID:21273001

  11. 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.

  12. 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.

  13. 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

  14. Production optimization of sucker rod pumping wells producing viscous oil in Boscan field, Venezuela

    SciTech Connect

    Guirados, C.; Sandoval, J.; Rivas, O.; Troconis, H.

    1995-12-31

    Boscan field is located in the western coast of Maracaibo lake and is operated by Maraven S.A., affiliate of Petroleos de Venezuela S.A. It has 315 active wells, 252 of which are produced with sucker rod pumping. Other artificial lift methods currently applied in this field are hydraulic (piston) pumping (39 wells) and ESP (24 wells). This paper presents the results of the production optimization of two sucker rod pumping wells of Boscan field producing viscous oil. This optimization has been possible due to the development of a new production scheme and the application of system analysis in completion design. The new production scheme involves the utilization of a subsurface stuffing box assembly and a slotted housing, both designed and patented by Intevep S.A., affiliate of Petroleos de Venezuela S.A. The completion design method and software used in the optimization study were also developed by Intevep S.A. The new production scheme and design method proved to be effective in preventing the causes of the above mentioned problems, allowing the increase of oil production under better operating conditions.

  15. 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…

  16. Complete genome sequence of Streptomyces venezuelae ATCC 15439, a promising cell factory for production of secondary metabolites.

    PubMed

    Song, Ju Yeon; Yoo, Young Ji; Lim, Si-Kyu; Cha, Sun Ho; Kim, Ji-Eun; Roe, Jung-Hye; Kim, Jihyun F; Yoon, Yeo Joon

    2016-02-10

    Streptomyces venezuelae ATCC 15439, which produces 12- and 14-membered ring macrolide antibiotics, is a platform strain for heterologous expression of secondary metabolites. Its 9.05-Mb genome sequence revealed an abundance of genes involved in the biosynthesis of secondary metabolites and their precursors, which should be useful for the production of bioactive compounds. PMID:26718561

  17. Assessing the Educational and Financial Needs of Small-Scale Dairy Farmers in Socopo, Venezuela. Summary of Research 64.

    ERIC Educational Resources Information Center

    Nieto, Ruben D.; Henderson, Janet L.

    The process of transferring agricultural technology in many countries was studied to determine the perceived educational and financial needs of small-scale dairy farmers in Socopo, Venezuela. The following data were collected: (1) demographic characteristics--age, educational level, farm size, number of lactating cows, dairy farming experience,…

  18. 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

  19. 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.

  20. 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

  1. 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

  2. [Meaning of drugs use for adolescents living in the streets, Valencia, Venezuela].

    PubMed

    Alvarado-Chacón, Roberto; Silva, Marta Angélica Iossi; Guzmán-Facundo, Francisco; Serrano-Cazorla, Ronald Igor; Bencomo, Alexander

    2011-06-01

    This descriptive study with a qualitative approach aims to reveal the meaning of drugs use among adolescents living in the street, a condition that turns them into a social problem, so that theoretical approach seeks to understand the phenomenon. Seven (7) female adolescents living on the Cabriales walk in Valencia, Venezuela were interviewed. Grounded Theory and symbolic interactionism were used for data processing. Thus, the following categories were noticed: The search not to be good, Reaffirmation of the role of women, Consumption as experience, The gaze of others to the adolescent who uses drugs and The addict as a caregiver. Finally, we found that the use of drugs on the street for girls is a form of protection, survival and inclusion in the group. PMID:21739056

  3. 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.

  4. 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

  5. [Reproduction of the bird Mimus gilvus (Passeriformes: Mimidae) in Maracaibo, Venezuela].

    PubMed

    Paredes, M; Weir, E; Gil, K

    2001-01-01

    Four pairs of the poorly understood tropical mockingbird Mimus gilvus were captured and color banded at a grassland in Maracaibo, Venezuela in June 1997. Throughout the following 8 months, individuals were observed two days per week for 4 hours each. We recorded courtship behaviour, nest construction, incubation, parental care, territory defense and timing of reproductive cycle. Pairs lived in defined territories defended primarily by the male. Both sexes participated in nest building which began at the start of two rainy seasons: April and October. Between April and June, 80% of nests were parasited by the shiny cowbird (Molothrus bonariensis). No parasitism was recorded in the later nesting season. Consequently, breeding success for the April and October seasons was 20% and 83% respectively. Only the female incubated and the mean clutch size was 2.2 eggs. PMID:12189795

  6. The geothermal area of El Pilar-Casanay, State of Sucre, Venezuela: Geochemical exploration and model

    SciTech Connect

    D'Amore, F.; Gianelli, G.; Corazza, E. . Istituto Internazionale Ricerche Geotermiche)

    1994-06-01

    A geochemical survey was carried out in the El Pilar-Casanay area, State of Sucre, Venezuela, in order to ascertain its geothermoelectric potential. The area is characterized by many natural manifestations with temperatures in the range 80--100 C. The area investigated seems capable of producing high-enthalpy geothermal fluids; a deep reservoir is inferred, composed of a medium salinity (< 5,000 ppm) and neutral brine, with computed temperatures between 250 and 300 C, and with a high CO[sub 2] partial pressure. Second shallower reservoir is assumed to exist, with a temperature of the order of 200--220 C. The deep reservoir is shown to be liquid-dominated, while water and steam occupy the shallow one. The piezometric level (elevation 150 m) regulates the areal distribution of water springs and fumaroles. A partial self-sealing (mineral alteration) along outflows allows accumulation of hot fluids, while recharge is from local meteoric water.

  7. FIRST REPORT OF METALLO-β-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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Cretaceous and Tertiary palynology used in the geological understanding of the Maturin sub-basin, Venezuela

    SciTech Connect

    Paredes, I.; Fasola, A. )

    1991-03-01

    The use of palynology and micropaleontology, two biostratigraphic tools used at Intevep, S.A., have been of great help in the geological understanding during studies done on cores of the Maturin subbasin, a foreland type basin in Eastern Venezuela. Basically, the palynological work consisted of palynological and palynofacies analysis used to determine ages and to interpret the paleoenvironments of deposition in comparison with the interpretations obtained through sedimentological and micropaleontological studies. Palynomorph assemblages and palynofacies are shown for the quiescent Late Cretaceous, for the Tertiary in sequences that are not exactly dated and probably represent the first compressive movements in the basin, and for the Oligocene. In general, in these sequences it was possible to determine marine environments varying from near-shore to inner neritic, and also subaereal paleosols in the Cretaceous. The work highlights the importance of multidisciplinary studies in order to obtain interpretations more in accordance with reality.

  16. 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.

  17. [Polychaetes (Annelida: Polychaeta) epibiont on Spondylus americanus (Bivalvia: Spondylidae) from Mochima National Park, Venezuela].

    PubMed

    Liñero Arana, Ildefonso; Díaz Díaz, Oscar

    2006-09-01

    The polychaetes epibiontic on the mollusk Spondylus americanus Hermann, 1781 were extracted from mollusks hand-collected at a depth of 10-30 m in Mochima National Park, Venezuela (10 degrees 21'00" N-63 degrees 23'36" W), using scuba diving gear. Forty-three polychaete species were identified on the 32 bivalve specimens analyzed. The Serpulidae included 17 especies, Eunicidae six and Terebellidae four species. The most abundant species were Hydroides dirampha Mörch, 1863, Pileolaria militaris Claparède, 1868 (Serpulidae), and Notaulax nudicollis Krøyer, 1856 (Sabellidae). Their geographic affinitie were: 51.3% Atlantic, 28.2% widely distributed, 17.9% Amphiamericans, and 2.6% have a disjunct distribution. PMID:18491616

  18. Surveillance of HIV type 1 drug resistance among naive patients from Venezuela.

    PubMed

    Castillo, Julio; Comegna, Mario; Quijada, Wilmary; Jauvin, Valérie; Pinson, Patricia; Masquelier, Bernard; Fleury, Hervé; Castro, Erika

    2009-12-01

    We have studied 65 HIV-1-infected untreated patients recruited in Caracas, Venezuela with TCD4 counts > or =350/microl. The reverse transcriptase and protease sequences of the virus were sequenced, aligned with reference HIV-1 group M strains, and analyzed for drug resistance mutations. Most of the viruses were subtype B genotype in both the protease and RT genomic regions. Five of the 62 virus isolates successfully amplified showed evidence of recombination between protease and RT, with their protease region being non-B while their RT region was derived from subtype B. Four strains were found bearing resistance mutations either to NRTIs, NNRTIs, or PIs. The prevalence of HIV-1 isolates bearing resistance mutations was therefore above the 5% threshold of WHO. PMID:19954301

  19. 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

  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. Cenozoic Plate tectonic history of the northern Venezuela-Trinidad Area

    NASA Astrophysics Data System (ADS)

    Erlich, Robert N.; Barrett, S. F.

    1990-02-01

    Geological and geophysical data, coupled with recent plate tectonic reconstructions, suggest that the Cenozoic geologic history of the northern Venezuela-Trinidad area has been dominated by strike-slip displacement of discrete crustal blocks. Allochthonous terranes within the area include metavolcanic rocks of the Cretaceous Villa de Cura Group and metamorphic rocks of the Precambrian to Cretaceous Cordillera de la Costa. A relatively competent crustal block (Margarita Block) is defined by an outline around the metamorphic basement of Margarita Island, the Araya/Paria peninsula, the Northern Range of Trinidad, and Tobago Island. Reconstruction of the Margarita Block to its original position requires at least partial closure of the Falcon Basin, closure of the Bonaire and Cariaco basins, and restoration of about 50 km of motion on both the Oca and Bocono faults. Post middle Eocene eastward translation of the Caribbean plate caused eastward motion of the Margarita Block. A minor change in relative plate motion during the late Oligocene or early Miocene produced a right step in the Moron fault, forming the Cariaco pull-apart basin and El Pilar fault zone. Maximum offset on El Pilar fault is estimated to be no more than 125 km, though displacement along the entire fault zone may have been greater. Transpressional stresses between the Caribbean plate and northern South America caused folding of the Serrania del Interior of Venezuela and the Central Range of Trinidad. Eastward migration of transpressional stresses at the southeastern corner of the Caribbean-South American plate boundary is being accommodated by formation of oblique thrusts, transpressive anticlines, and downwarping of the crust. Bouguer gravity data suggest that Jurassic-aged Atlantic oceanic crust is being depressed as the Caribbean plate expands into the Demerara Plateau area. This study suggests that the faults and transtensional/transpressional/compressional structures identified in this study are the result of stresses produced during the large eastward translation of the Caribbean plate since the Paleocene, and are not the product of a shear couple.

  2. Dengue virus infections in a cohort of schoolchildren from Maracay, Venezuela: a 2-year prospective study.

    PubMed

    Comach, Guillermo; Blair, Patrick J; Sierra, Gloria; Guzman, Diamelis; Soler, Maritza; de Quintana, Maritza Cabello; Bracho-Labadie, Mergiory; Camacho, Daria; Russell, Kevin L; Olson, James G; Kochel, Tadevsz J

    2009-02-01

    In 2001, we began a prospective longitudinal study in a cohort of schoolchildren 5-13 years of age residing in Maracay, Venezuela, to determine the cumulative incidence of dengue virus (DENV) infections by virus serotype. This report presents serological data from 710 schoolchildren who were tested during the first 2 years of the study. Serological evaluations were conducted by plaque reduction neutralization test (PRNT). At study initiation, 51% of children had PRNT antibody titers against one (30.1% = 13.4% DENV-1, 14.2% DENV-2, 0.6% DENV-3, and 2% DENV-4) or multiple DENV serotypes (20.9%). By the end of the first year, 89 of 348 (25.6%) PRNT-negative children seroconverted, and 94 of 362 (26%) who were PRNT-positive in their baseline sera tested positive for additional serotypes, for an overall cumulative incidence of DENV infections of 25.8%. By serotype, the percentages found were 1.4% DENV-1, 1.4% DENV-2, 19% DENV-3, and 1.2% DENV-4. In the second year, 37 of 259 (14.3%) PRNT-negative children seroconverted, and 83 of 451 (18.4%) who had monotypic and multitypic PRNT patterns in their baseline sera exhibited additional serotype seroconversions, for an overall cumulative incidence of DENV infections of 16.9%. By serotype, the percentages found were 0.8% DENV-1, 1.5% DENV-2, 8.5% DENV-3, and 2.3% DENV-4. Overall, these results suggest a high cumulative incidence of DENV infections among 5-13-year-old school children in Maracay, Venezuela. PMID:18788903

  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. Historical Earthquakes As Examples To Assess The Seismic Hazard In The Eastern Region of Venezuela

    NASA Astrophysics Data System (ADS)

    Martin, J.; Posadas, A.; Avendaño, J.; Sierra, R.; Bonive, F.

    The North-East region of Venezuela lies on the border of the friction zone between the Caribbean and South-American tectonic plates, a source of great seismicity. The first written news of an earthquake in the American Continent were those of the earth- quake of september 1530 which caused damage to Cumaná, the first town of that Continent. Since then a continuous series of earthquakes have been reported, many of them with damaging effects on Cumaná; those caused in the 1929 earthquake (17-01- 1929; with IX Mercalli degrees) were well described by Sidney Paige in the Vo. 20 of the B.S.S.A., March, 1930. An earthquake of magnitude 5.9 {11-06-1986; 10.26z N,63.29z W} was the trigger for the Unesco`s intention to declare the Estado Sucre as a pilot zone for seismological studies. In 1991 a report issued by the International Institute of Earthquake Prediction Theory and Matematical Geophysics (Academy of Sciences, U.R.S.S.) stated that the ocurrence of an earthquake of great magnitude which could affect the North-East region of Venezuela was possible. Other studies of the seismicity of the region have been carried out. The interest of the authorities and of the seismologists reached a peak with the earthquake of july 1997 (10.456z N, 63.555z W), with a magnitude of 6.9; there was a death toll of 73, around 528 people injured and more than 2000 houses needed to be completely rebuilt. A study of micro- zonification of the city of Cumaná has been carried out recently and the results of this study will be presented also to this Congress.

  5. Venezuela offshore oil and gas production development: Past, present and future

    SciTech Connect

    Perez La Salvia, H.; Schwartz, E.; Contreras, M.; Rodriguez, J.I.; Febres, G.; Gajardo, E.

    1995-12-01

    This paper presents a short history of offshore oil and gas production in Venezuela starting in Lake Maracaibo in 1923. The main emphasis has been the results of the recent R and D and the exploratory offshore programs in areas like Orinoco Delta located in the Atlantic Ocean, Northeast and Northwest Venezuela in the Caribbean sea. In the R and D offshore program the main objectives were: (1) To establish the local environmental, oceanographical, geotechnical and seismicity conditions for the Venezuelan Continental Platform. (2) To give a technical support to the PDVSA Operating Affiliates during the exploratory programs including: (a) to develop accurate drilling vessel positioning systems; (b) evaluation of sea bottom geotechnical conditions for safely operating the jack-ups and drilling vessels involved in the exploratory wells and (c) to identify those areas which because of their special nature require further investigation to establish preliminary type of platforms required for the areas to be developed or to evaluate other solutions proposed by Foreign Consultant Engineering Companies to the PDVSA Operating Affiliated Companies. The main objective of PDVSA for the coming future will be to develop the North of Paria Gas Field through the initially named Christopher Columbus Project now Sucre Gas, S.A., a consortium conformed by LaGoven, S.A. Shell, Exxon and Mitsubishi. objective of this paper is to give an idea of the history of the Venezuelan Oil and Gas Offshore development giving emphasis to the results of the INTEVEP S.A. Red offshore program and to show some results of the particular characteristics of oceanographical, environmental, geotechnical and seismic conditions in the main areas evaluated during the exploratory program: Orinoco Delta, Gulf of Paria and North of Paria.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Characterization and distribution of tomato yellow margin leaf curl virus, a begomovirus from Venezuela.

    PubMed

    Nava, A; Londoño, A; Polston, J E

    2013-02-01

    A begomovirus causing mottling and leaf deformation in tomato from the State of Mérida was cloned and sequenced. The virus has a bipartite genome comprised of a DNA-A (2,572 nucleotides) and a DNA-B (2,543 nucleotides) with a genome organization typical of New World begomoviruses. Both components share a common region of 115 nucleotides with 98 % sequence identity. Phylogenetic analysis indicated that while no virus sequences were closely related, the A component was distantly related to those of two other tomato-infecting viruses, tomato leaf deformation virus and Merremia mosaic virus; and the DNA-B, to those of pepper huasteco yellow vein virus and Rhynchosia golden mosaic Yucatan virus. The DNA-A and DNA-B sequences were submitted to GenBank (accession no. AY508993 and AY508994, respectively) and later accepted by the International Committee on Taxonomy of Viruses as the genome of a member of a unique virus species with the name Tomato yellow margin leaf curl virus (TYMLCV). Tomato (Solanum lycopersicum L. 'Fl. Lanai') plants inoculated with cloned TYMLCV DNA-A and DNA-B became systemically infected and showed chlorotic margins and leaf curling. The distribution of TYMLCV in tomato-producing states in Venezuela was determined by nucleic acid spot hybridization analysis of 334 tomato leaf samples collected from ten states using a TYMLCV-specific probe and confirmed by PCR and sequencing of the PCR fragment. TYMLCV was detected in samples from the states of Aragua, Guárico, and Mérida, suggesting that TYMLCV is widely distributed in Venezuela. PMID:23064695

  11. 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.

  12. Source investigation of two outbreaks of skin and soft tissue infection by Mycobacterium abscessus subsp. abscessus in Venezuela.

    PubMed

    Torres-Coy, J A; Rodríguez-Castillo, B A; Pérez-Alfonzo, R; DE Waard, J H

    2016-04-01

    Outbreaks of soft tissue or skin infection due to non-tuberculous mycobacteria are reported frequently in scientific journals but in general the infection source in these outbreaks remains unknown. In Venezuela, in two distinct outbreaks, one after breast augmentation surgery and another after hydrolipoclasy therapy, 16 patients contracted a soft tissue infection due to Mycobacterium abscessus subsp. abscessus. Searching for the possible environmental infection sources in these outbreaks, initially the tap water (in the hydrolipoclasy therapy outbreak) and a surgical skin marker (in the breast implant surgery outbreak), were identified as the infection sources. Molecular typing of the strains with a variable number tandem repeat typing assay confirmed the tap water as the infection source but the molecular typing technique excluded the skin marker. We discuss the results and make a call for the implementation of stringent hygiene and disinfection guidelines for cosmetic procedures in Venezuela. PMID:26441024

  13. Male sex pheromones and the phylogeographic structure of the Lutzomyia longipalpis species complex (Diptera: Psychodidae) from Brazil and Venezuela.

    PubMed

    Watts, Phillip C; Hamilton, J Gordon C; Ward, Richard D; Noyes, Harry A; Souza, Nataly A; Kemp, Stephen J; Feliciangeli, M Dora; Brazil, Reginaldo; Maingon, Rhayza D C

    2005-10-01

    Lutzomyia longipalpis, a sibling complex, is the main vector of Leishmania chagasi/infantum. Discriminating between siblings is important as they may differ in vectorial capacity. Lutzomyia longipalpis populations display distinct male sex pheromone chemotypes. We investigated the phylogeographic pattern of variation at microsatellite loci from 11 populations from Brazil and Venezuela related to their male pheromone. Temporal genetic differentiation was mostly not significant at the same site. Spatial genetic differentiation was, however, strong, although there was only a weak relationship between genetic differentiation and the geographic distance separating the samples (r2 < 0.10); geographic separation explained a much greater (54-97%) percentage of the genetic differences among populations when samples with the same pheromone type were analyzed separately. A cluster analysis showed five groups: Lu. cruzi (Brazil) and Lu. pseudolongipalpis (Venezuela) as separate species, two (mostly 9-methyl-germacrene-B) Venezuelan and Brazilian groups, and a very distinct cluster of Brazilian cembrene populations. PMID:16222018

  14. Development of an Unnatural Amino Acid Incorporation System in the Actinobacterial Natural Product Producer Streptomyces venezuelae ATCC 15439.

    PubMed

    He, Jingxuan; Van Treeck, Briana; Nguyen, Han B; Melançon, Charles E

    2016-02-19

    Many Actinobacteria, most notably Streptomyces, produce structurally diverse bioactive natural products, including ribosomally synthesized peptides, by multistep enzymatic pathways. The use of site-specific genetic incorporation of unnatural amino acids to investigate and manipulate the functions of natural product biosynthetic enzymes, enzyme complexes, and ribosomally derived peptides in these organisms would have important implications for drug discovery and development efforts. Here, we have designed, constructed, and optimized unnatural amino acid systems capable of incorporating p-iodo-l-phenylalanine and p-azido-l-phenylalanine site-specifically into proteins in the model natural product producer Streptomyces venezuelae ATCC 15439. We observed notable differences in the fidelity and efficiency of these systems between S. venezuelae and previously used hosts. Our findings serve as a foundation for using an expanded genetic code in Streptomyces to address questions related to natural product biosynthesis and mechanism of action that are relevant to drug discovery and development. PMID:26562751

  15. COMO - A Program For Optical Design

    NASA Astrophysics Data System (ADS)

    Vollrath, Wolfgang

    1986-10-01

    COMO is an optical design program of a special orthogonalization type, developed by Prof. H.Marx at Ernst Leitz Wetzlar Company. Not using a merit function, COMO corrects aberrations under equality and inequality constraints not simultaneously but sequentially, the order is chosen by the optical designer. The optimization procedure shows distinctive features compared to other programs. COMO is in use at Leitz since the early 1970's and is now running on HP-1000F and HP-A900 computer systems. In 1974, when it was implemented on a HP-2100, it was probably one of the very first "mainfrawe" optical design programs running on a minicomputer. H.Marx named this program COMO.

  16. 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

  17. 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

  18. Beta-glucosylation as a part of self-resistance mechanism in methymycin/pikromycin producing strain Streptomyces venezuelae.

    PubMed

    Zhao, Lishan; Beyer, Noelle J; Borisova, Svetlana A; Liu, Hung-wen

    2003-12-23

    In our study of the biosynthesis of D-desosamine in Streptomyces venezuelae, we have cloned and sequenced the entire desosamine biosynthetic cluster. The deduced product of one of the genes, desR, in this cluster shows high sequence homology to beta-glucosidases, which catalyze the hydrolysis of the glycosidic linkages, a function not required for the biosynthesis of desosamine. Disruption of the desR gene led to the accumulation of glucosylated methymycin/neomethymycin products, all of which are biologically inactive. It is thus conceivable that methymycin/neomethymycin may be produced as inert diglycosides, and the DesR protein is responsible for transforming these antibiotics from their dormant to their active forms. This hypothesis is supported by the fact that the translated desR gene has a leader sequence characteristic of secretory proteins, allowing it to be transported through the cell membrane and hydrolyze the modified antibiotics extracellularly to activate them. Expression of desR and biochemical characterization of the purified protein confirmed the catalytic function of this enzyme as a beta-glycosidase capable of catalyzing the hydrolysis of glucosylated methymycin/neomethymycin produced by S. venezuelae. These results provide strong evidence substantiating glycosylation/deglycosylation as a likely self-resistance mechanism of S. venezuelae. However, further experiments have suggested that such a glycosylation/deglycosylation is only a secondary self-defense mechanism in S. venezuelae, whereas modification of 23S rRNA, which is the target site for methymycin and its derivatives, by PikR1 and PikR2 is a primary self-resistance mechanism. Considering that postsynthetic glycosylation is an effective means to control the biological activity of macrolide antibiotics, the availability of macrolide glycosidases, which can be used for the activation of newly formed antibiotics that have been deliberately deactivated by engineered glycosyltransferases, may be a valuable part of an overall strategy for the development of novel antibiotics using the combinatorial biosynthetic approach. PMID:14674753

  19. 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

  20. 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

  1. 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

  2. Black Hispanics have a worse cardiovascular risk profile than mixed Hispanics in Venezuela.

    PubMed

    Ryder, Elena; Silva, Eglee; Sulbarán, Tulio; Fernández, Virginia; Campos, Gilberto; Calmon, Gustavo; Clavell, Emilio; Raleigh, Xiomara; Florez, Hermes

    2007-03-01

    In order to characterize components of the metabolic syndrome (MS) in Venezuelan black Hispanics and compare these metabolic abnormalities with those found in the predominant mixed Hispanic population, 2336 mixed Hispanics (69% women) and 281 black Hispanics (60% women), aged 20-78 years, without prior history of diabetes and/or cardiovascular disease were evaluated in a population-based study in Zulia State, Venezuela. Blood pressure (BP), waist circumference, as well as fasting insulin, fasting blood glucose (FBG), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) levels were measured. The criteria proposed by the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) to identify those with metabolic abnormalities were used. We found that black Hispanics showed higher frequency of age-adjusted elevated BP than mixed Hispanics in both men (66.9% vs. 52.3%, p < 0.01) and women (39.3% vs. 30.4%, p < 0.05). In men, elevated FBG was also more frequent in black Hispanics (32.7%) than in mixed Hispanics (22.3%), despite the lack of significant differences in fasting insulin, HOMA-insulin resistance and HOMA-beta cell function values. In women low HDL-C and higher abdominal obesity were more common in black Hispanics (71.8% and 54.1%, respectively) than in mixed Hispanics (56.2% and 44.5%, respectively), despite the greater frequency of high TG in mixed Hispanics (22.6%) when compared to black Hispanics (13.3%). Furthermore, in logistic regression analysis black Hispanic race was independently associated with higher risk for hypertension, fasting hyperglycemia, and low HDL-C. These results suggest that black Hispanics have worse cardiovascular risk profile than mixed Hispanics in Zulia State, with higher BP, higher FBG, more abdominal obesity, and lower HDL-C. Identification and intervention of these high-risk subjects are important strategies for diabetes and cardiovascular disease prevention in Venezuela. PMID:17432543

  3. 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

  4. Rechenverfahren des optischen Korrektionsprogrammms "COMO". Teil 1.

    NASA Astrophysics Data System (ADS)

    Marx, H.

    1989-03-01

    COMO is a program of an orthogonalization type that was developed in order to achieve that each elementary correction step makes immediate use of the shortest possible step in the system data space even if many rigid boundary conditions are to be taken into account (optimization under constraints). COMO usually does not correct aberrations simultaneously (by minimization), but one after the other. The order is given by the optical designer. For each aberration (paraxial data included) one can either specify a target value or a bandwidth between a lower and an upper limit.

  5. Patterns of ant (Hymenoptera: Formicidae) richness and relative abundance along an aridity gradient in Western Venezuela.

    PubMed

    Pérez-Sánchez, A J; Lattke, J E; Viloria, A L

    2013-04-01

    In xeric ecosystems, ant diversity response to aridity varies with rainfall magnitude and gradient extension. At a local scale and with low precipitation regimes, increased aridity leads to a reduction of species richness and an increased relative abundance for some ant species. In order to test this pattern in tropical environments, ant richness and relative abundance variation were evaluated along 35 km of an aridity gradient in the Araya Peninsula, state of Sucre, Venezuela. Three sampling stations comprising five transects each were set up. Pitfall traps and direct collecting from vegetation were assessed per transect. Overall, 52 species, 23 genera, and 7 subfamilies of ants were recorded in the peninsula. The total number of species and genera recorded by both sampling stations and transects decreased linearly with increasing aridity. Total relative abundance was highest in the most arid portion of the peninsula, with Crematogaster rochai (Forel) and Camponotus conspicuus zonatus (Emery) (Hymenoptera: Formicidae) being the numerically dominant species. Spatial and multivariate analyses revealed significant changes in ant composition every 11 km of distance, and showed a decrease of ant diversity with the increase of harsh conditions in the gradient. Here, we discuss how local geographic and topographic features of Araya originate the aridity gradient and so affect the microhabitat conditions for the ant fauna. PMID:23949745

  6. [Cryptobenthic coral reef fishes in Los Roques National Park, Caribbean of Venezuela].

    PubMed

    Rodríguez-Quintal, José G

    2010-03-01

    A significant portion of coral reef fish assemblages are composed of small cryptobenthic fishes, but these are poorly represented in regional fish characterization works. We characterized the cryptobenthic reef fish community associated with coral reef in Los Roques National Park during six week surveys. The study included 11 locations in which these fish were registered in transects of 10 x 2 m. Specimens were collected using the suction method and a fine-mesh net. A total of 31 species of six families were collected (four Blenniidae, six Chaenopsidae, one Gobiesocidae, 12 Gobiidae, seven Labrisomidae and one Tripterygiidae). Six represented new records to the park, and Coralliozetus cardonae (Chaenopsidae) was a new record for Venezuela. The most important families were Gobiidae, Chaenopsidae and Labrisomidae. Cryptic fish assemblages changed with the reef environments, with a clear distribution pattern: some species were only observed in shallow areas of less than 5 m depth, while in fringing and barrier reef areas, other species were present and differentially distributed between the reef crest and the seaward slope. These patterns probably are related to the close association that these small fish maintain with the benthos. PMID:20411725

  7. 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

  8. The hydrocarbon habitat of northern South America: Colombia-Venezuela-Trinidad

    SciTech Connect

    James, K.H.

    1996-08-01

    A prolific hydrocarbon province extends across the northern margin of South America from Colombia to east of Trinidad. Two key components are a world-class source rock, formed on a regional Late Cretaceous passive margin, and a complex tectonic setting in which a variety of structural and stratigraphic traps, reservoirs, seals and hydrocarbon kitchens have evolved through time. Convergence between the Farallon and Caribbean plates with South America culminated in the late Cretaceous-early Palaeogene with emplacement of Colombia`s Central Cordillera in the west and a nappe-foreland basin system in the north. Regional hydrocarbon generation probably occurred below associated basins. Subsequent oblique convergence between the Caribbean and South America, partitioned into strike-slip and compressional strain, generated an eastward migrating and ongoing uplift-foredeep (kitchen) system from central Venezuela to Trinidad. Similarly, oblique interaction of western Colombia with the Nazca Plate caused segmentation of the earlier orogen, northward extrusion of elements such as the Maracaibo Block, and eastward migration of uplift progressively dividing earlier kitchens into localized foredeeps.

  9. [Soil microbial activity variation after land use changes in savannah, Llanos Orientales, Venezuela].

    PubMed

    Gómez, Yrma; Paolini, Jorge

    2011-03-01

    In West plains of Venezuela, the traditional land use of the Trachypogon savannah, has been the extensive grazing. The pressure over these savannahs to obtain a major animal productivity has stimulated the introduction of exotic forage plants, such as Brachiaria brizantha and Andropogon gayanus. In spite that great savannah extensions have been subject to this land use change, information about the effect that pastures and grazing activity have on microbial activity in these soils is scarce. So the objective of this study was to determine the impact that the extensive grazing and cover substitution have on microbial activity. The soil sampling was carried out during the dry and rainy seasons. The employed parameters to determine changes in soil microbial activity were the substrate induced respiration (SIR), basal respiration (BR), the dehydrogenase activity (DHS), the fluorescein diacetate hydrolysis (FDA) and the arginene ammonification (AA). The similarity of the structural soil characteristics studied allows us to infer, that the differences in the microbiological parameters are determined by climatic conditions and soil management. The results show that there is a low microbial activity in these soils. The rainy season caused an increase in all the microbiological parameters determined. B. brizantha made a greater contribution to soil carbon and promoted a greater heterotrophic activity. The extensive grazing and the low stocking rate in the West plain savannas did not affect the microbial activity in these soils. PMID:21516636

  10. 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.

  11. Trace elements of Paleocene Táchira coals, southwestern Venezuela: a geochemical study

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Escobar, M.; Esteves, I.; Lopez, C.; Galarraga, F.; González, R.

    2001-09-01

    The concentration and distribution of 35 elements in 78 coal samples from the Táchira State coal fields belonging to Los Cuervos Formation (Paleocene) of western Venezuela were obtained using atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission (ICP-AES). The aim of this work was to determine, through a multivariate statistical approach (factor analysis), if there is a correlation between the trace element content in coal beds and the provenance rocks at the time of peat deposition. Comparison with world averages and geometric means for trace element concentrations in coal-bed samples shows that B, Ba, La, V, Mn, Zn, and Pb are depleted. However, Táchira coal samples show a perceptible enrichment in Bi, Sb, As, Cd, and Mo, and they are highly enriched in Ag and Co. Nicholl's plot suggests that only B and Co show a distinctive organic affinity. Enriched elements (Ni, Ag, Cd, Mo, Co) are both statistically and genetically related, and we attribute their origin to a volcaniclastic Jurassic unit. Other statistical factors (Th-V-P and Ca-Mg-Mn) reveal a different provenance, indicating a felsic plutonic source and a sedimentary limestone, respectively. A fourth factor (K-Mo-Th-S) is composed mainly of clay minerals and authigenic sulfides.

  12. [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

  13. [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

  14. 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

  15. 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

  16. 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.

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

    PubMed

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

    2013-04-01

    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® 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

  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. 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.

  20. [Trichogramma species (Hymenoptera: Trichogrammatidae) parasitoids of Lepidopteran eggs in Lara State, Venezuela].

    PubMed

    Morales, José; Vásquez, Carlos; Pérez B, Nieves L; Valera, Neicy; Ríos, Yolmar; Arrieche, Norayda; Querino, Ranyse B

    2007-01-01

    This work was conducted to determine the occurrence of Trichogramma wasp species in Lara State, Venezuela. Lepidopteran egg samples collected from various crop leaves were observed daily under laboratory conditions for emergence of Trichogramma species adult wasps. Trichogramma were also obtained from traps containing eggs from the hosts Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). In the laboratory, specimens of Trichogramma species were mounted on microscope slides to show male genitalia and other morphological characters used for its identification. Trichogramma atopovirilia Oatman y Platner emerged from S. frugiperda eggs collected in a cornfield at La Palomera, Humocaro Alto and at El Parchal, Humocaro Bajo, Municipio Morán. T. atopovirilia also emerged from S. frugiperda eggs collected in a cornfield at Sabana Grande and from S. cerealella eggs used as traps in a pepper culture at Tintinal, Municipio Andrés Eloy Blanco. T. exiguum Pinto y Platner emerged from S. frugiperda eggs used as traps or collected in cornfield at Totumito and at La Palomera, Humocaro Alto. T. pretiosum Riley emerged from Phthorimaea operculella Zeller eggs collected on stored potatoes at Monte Carmelo, Sanare. The identification of Trichogramma species in Lara State would be useful in the development of biological control programs for lepidopteran pests. PMID:17934619

  1. 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.

  2. 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

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

    PubMed

    Noya, Belkisyolé Alarcón de; 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

  4. 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.

  5. 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.

  6. Integrating complexity of social systems in natural hazards planning: An example from Caracas, Venezuela

    NASA Astrophysics Data System (ADS)

    Vranes, Kevin; Czuchlewski, Kristina R.

    In December 1999, days of heavy rain on steep slopes north of Caracas, Venezuela triggered massive mud and debris flows, killing tens of thousands. Partly in response to this disaster, a multidisciplinary team of urban planners and Earth scientists from Columbia University recently developed a framework plan for building disaster resilience into the Venezuelan capital region. After assessing the complex intersection of urban geography with severe seismic and hydrologic hazards, substantial recommendations were made to local and regional authorities on future hazards mitigation.Areas found most at risk in the Caracas region include the transportation and utility infrastructure and the friable building stock of squatter settlements. Recognizing realistic economic and socio-political constraints on implementing change, a prioritized list of goals and activities was constructed, and recommendations made along various time scales. Immediate disaster-avoidance goals (to be completed within 1 to 5 years) include strengthening critical infrastructure nodes, housing stock, and emergency services. More intermediate goals (5 to 10 years) focus on upgrading fragile housing units, creating detailed hazard maps across the city, and incorporating disaster education into cultural activities. Recommended activities for the long term (beyond 10 years) include creating a fully redundant transportation and water delivery network, establishing legitimate land title for squatters, and re-locating critical facilities currently in high-risk areas.

  7. [Zinc plasma levels in a low socioeconomic status population of children in Maracaibo, Venezuela].

    PubMed

    Amaya, D; Urrieta, R; Gil, N M; Molano, N C; Medrano, I; Castejón, H V

    1997-03-01

    The objective of the present work was to determine plasma zinc concentration in a children's population belonging to low income families in Maracaibo, Venezuela. One hundred fifty-nine children (M:75;F:84) aged 3 months to 8 years were studied by clinic, anthropometric and socio-economical parameters. Fasting peripheral venipuncture blood samples were obtained and analyzed for plasma zinc using atomic absorption spectrophotometry. Plasma zinc levels were low (< 75 micrograms/dl) in 38.36% of the children studied. In turn, 33.89% of the eutrophic group, and 41% of the malnourished group were zinc deficient. By analyzing separately the group of children in which plasma zinc levels ranged between 75-80 micrograms/dl (critical zone), it could be seen that 18.65% of eutrophic and 10% of malnourished children belonged to this group. Thus, over 50% of the total children's population studied had critical or deficient plasma zinc levels. Therefore, functional studies on nutritional status of zinc are recommended to the Venezuelan children population; in case of being evidently deficitary, it is necessary to establish immediate zinc supplementation nutritional programs; especially for children coming from low income families. PMID:9429636

  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. 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.

  10. Resistance to malathion and deltamethrin in Aedes aegypti (Diptera: Culicidae) from western Venezuela.

    PubMed

    Alvarez, Leslie C; Ponce, Gustavo; Oviedo, Milagros; Lopez, Beatriz; Flores, Adriana E

    2013-09-01

    Resistance to the insecticides deltamethrin and malathion and the enzymes associated with metabolic resistance mechanisms were determined in four field populations of Aedes aegypti (L.) from western Venezuela during 2008 and 2010 using the bottle assay and the microplate biochemical techniques. For deltamethrin, mortality rates after 1 h exposure and after a 24-h recovery period were determined to calculate the 50% knock-downconcentration (KC50) and the lethal concentration (LC50), respectively. For malathion, mortality was recorded at 24 h to determine the LC50. For deltamethrin, resistance ratios of knock-down resistance and postrecovery were determined by calculating the RRKC50 and RRLC50, comparing the KC50 and LC50 values of the field populations and those of the susceptible New Orleans strain. Knock-down resistance to deltamethrin was moderate in the majority of the populations in 2008 (RRKC50 values were between 5- and 10-fold), and only one population showed high resistance in 2010 (RRKC50 > 10-fold). Moderate and high postrecovery resistance to deltamethrin was observed in the majority of the populations for 2008 and 2010, respectively. There was significantly increased expression of glutathione-S-tranferases and mixed-function oxidases. All populations showed low resistance to malathion in 2008 and 2010 with significantly higher levels of alpha-esterases for 2008 and 2010 and beta-esterases for 2008. PMID:24180108

  11. 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.

  12. 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

  13. 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.

  14. Diagenesis and reservoir characterization of the Cretaceous-Tertiary sequence, eastern Venezuela

    SciTech Connect

    Aquado, B.; Ghosh, S.; Isea, A. )

    1990-05-01

    The giant El Furrial field Maturin subbasin is the most important oil field discovered in Venezuela in the last three decades. The average oil column has a thickness of 400 m and the reservoirs consist of essentially sandy siliciclastic sediments of nearshore-shallow marine origin. The oil's API gravity ranges from light to extra heavy and occurs in a stratified manner in the reservoirs. A total of 1,080 m of core from the producing sequence was studied through x-ray diffraction scanning electron microscopy, and petrography. This data, along with petrophysical measurements, show a clear differentiation between the Upper Cretaceous and the Oligocene reservoirs. The Upper Cretaceous reservoirs are characterized by relatively fine and uniform grain size, subarkosic composition with common volcanic rock fragments, high degree of chemical and mechanical compaction highly illitic mixed-layer I/S assemblage with less than 10% expandable layers, and ubiquitous baroque dolomite. Additionally, porosity and permeability values are persistently low. Clearly, the Cretaceous sediments are diagenetically mature and may indicate diagenetic transformation at greater depths or under a different thermal regime. In contrast the coarser grained Oligocene reservoirs of quartz arenitic composition show a lesser diagenetic overprint, and greater porosity and permeability. Porosity is dominantly secondary due to cement and grain (mostly quartz) dissolution, as well as tectonically induced grain fracturing. Common kaolinite and minor amounts of I/S with up to 20% of expandable layers attest to a lower diagenetic regime than in the Cretaceous reservoirs.

  15. Chemical kinetic model of hydrocarbon generation, expulsion, and destruction applied to the Maracaibo basin, Venezuela

    SciTech Connect

    Sweeney, J.J.; Braun, R.L.; Burnham, A.K.

    1995-10-01

    This paper describes the development and application of a compositional chemical model of hydrocarbon generation, expulsion,a nd destruction for the Cretaceous La Luna Formation source rock of the Maraciabo basin, Venezuela. Applications include both laboratory and geological settings. Laboratory pyrolysis experiments were used to study bulk oil generation, expulsion, and associated changes in composition of the kerogen, extractable organic matter, and expelled and unexpelled hydrocarbons. The laboratory experiments were also used to determine kinetic parameters to quantitatively describe organic reactions, via a computer model that also includes simulation of pressure-driven primary expulsion, over widely varying conditions. We show that the chemical model accuratley simulates the experimental results. Thermal history models for wells in the Maraciabo basin were used to simulate hydrocarbon generation and pore pressure development in the La Luna Formation and expulsion into nearby Cretaceous reservoirs. Results of the modeling indicate that both compaction disequilibrium and organic maturation play important roles in the development of excess pore pressure in the La Luna Formation. The model simulation of the variation of indicators such as Rock-Eval parameters and extract and oil compositions shows generally good agreement with measurements from remaining kerogen, oils, and extracts recovered from the La Luna Formation and from nearby Cretaceous reservoirs.

  16. 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.

  17. [Food consumption patterns of children 4 to 14 years old in Valencia, Venezuela].

    PubMed

    del Real, Sara Irene; Fajardo, Zuleida; Solano, Liseti; Concepción Páez, María; Sánchez, Armando

    2005-09-01

    Results from a nutritional assessment are presented to establish the usual food consumption pattern of 438 children between 4-14 years of age, from a low income urban community in Valencia, Venezuela. Food intake data were collected through multiple 24 hours recalls and converted to individual food item weight in grams. Amounts of energy, macronutrients, iron, calcium, vitamin A, and vitamin C were estimated to compare them to national references. The food pattern was established according to intake frequency per food item and per food groups. Arepa was the most commonly consumed food item, and a main source of kilocalories, protein, carbohydrates, iron, and vitamin A. Unlike coffee, fruits were not among the most commonly consumed foods. Black beans were the main source of protein. Cookies and sodas were among the major sources of energy. Energy and nutrient intake were adequate, except for calcium (67% in preschoolers y 43% in school-aged children). Preschoolers' diet showed a better adequacy for all nutrients (p < 0.005), except for iron which was significantly higher in school-aged children. Since children below 15 years old are still forming food behaviors and habits, they are an ideal group to develop nutritional education strategies to modify harmful patterns such as high intake of sodas, and low intakes of calcium rich foods. PMID:16454054

  18. Neotectonic map of Venezuela and neighboring areas at scale 1:2,000,000

    SciTech Connect

    Beltran, C. , Caracas )

    1993-02-01

    An updated neotectonic map of Venezuela is presented, synthetizing works carried out by the FUNVISIS Earth Science Workgroup since 1979 and which includes the northeastern Colombian region and Trinidad island. The map shows a main deformation belt, some 40 to 100 km wide, with the most important evidences of quaternary activity and considered as the boundary between South America and Caribbean plates. Two secondary belts defining the borders of the Maracaibo Block are outlined as well. In the main belt, the major features are represented by the inter-connected strike-slip fault systems of Bocono-San Sebastian-El Pilar-Los Bajos-El Soldado. Important tectonic complications can be observed along this belt, like the [open quotes]Pamplona indenter[close quotes] associated structures that connects to the frontal fault system of the Colombian Eastern Range in the western end, and in the eastern end the high compressive zone of Trinidad that constitutes a transition between the strike-slip fault system and the subduction zone of the lesser Antilles. In addition, oblique secondary systems can be seen at both sides of the principal deformation axis without crossing it. Two other important secondary systems, the Santa Marta-Bucaramanga and the Oca-Ancon faults, and the main fault of Bocono define the Block of Maracaibo, which is characterized by important internal deformations.

  19. Biostratigraphy of a Middle Miocene-Pliocene sequence from Cumarebo area, Falcon State, northwestern Venezuela

    SciTech Connect

    Giffuni, G. )

    1991-03-01

    The southern Caribbean region offers little in the way of continuous sequences for the late Neogene. An upward facies shallowing trend unfavorable for planktonic foraminifers and erosional truncation seems to be almost a rule for such sediments. A fairly complete sedimentary sequence mainly represented by clays, silts, and carbonate rocks from the Cumarebo region, Falcon State, northwestern Venezuela, was chosen to study the biostratigraphy of the late Neogene using foraminifers. More than one hundred surface samples were analyzed throughout. The study of foraminiferal fossil assemblages and other microfossils was also used to define paleoenvironments of deposition. Four formations are involved in this work. From base to top they are the Socorro, Caujarao, El Veral, and Tucupido. From the study of planktonic foraminifers, six biostratigraphic zones were recognized: Globorotalia mayeri Zone, Globorotalia menardii Zone, Globorotalia acostaensis Zone, Globorotalia humerosa Zone, Globorotalia margaritae Zone, and Globorotalia miocenica Zone. These zones indicate that the age of the sequence ranks from late middle Miocene to middle Pliocene. Generally speaking, with some variations, the paleoenvironments of the sequence show a shallowing trend from marine upper-middle bathyal to middle neritic. These results make an important contribution to the stratigraphy and geologic history of the Cumarebo area, which is related to the Agua Salada basin, and may help clarify the paleogeography and paleotectonic evolution of this region for petroleum exploration.

  20. 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

  1. [Soil microbial activity variation after land use changes in savannah, Llanos Orientales, Venezuela].

    TOXLINE Toxicology Bibliographic Information

    Gómez Y; Paolini J

    2011-03-01

    In West plains of Venezuela, the traditional land use of the Trachypogon savannah, has been the extensive grazing. The pressure over these savannahs to obtain a major animal productivity has stimulated the introduction of exotic forage plants, such as Brachiaria brizantha and Andropogon gayanus. In spite that great savannah extensions have been subject to this land use change, information about the effect that pastures and grazing activity have on microbial activity in these soils is scarce. So the objective of this study was to determine the impact that the extensive grazing and cover substitution have on microbial activity. The soil sampling was carried out during the dry and rainy seasons. The employed parameters to determine changes in soil microbial activity were the substrate induced respiration (SIR), basal respiration (BR), the dehydrogenase activity (DHS), the fluorescein diacetate hydrolysis (FDA) and the arginene ammonification (AA). The similarity of the structural soil characteristics studied allows us to infer, that the differences in the microbiological parameters are determined by climatic conditions and soil management. The results show that there is a low microbial activity in these soils. The rainy season caused an increase in all the microbiological parameters determined. B. brizantha made a greater contribution to soil carbon and promoted a greater heterotrophic activity. The extensive grazing and the low stocking rate in the West plain savannas did not affect the microbial activity in these soils.

  2. Chronology of mercury enrichment factors in reef corals from western Venezuela.

    PubMed

    Ramos, Ruth; Cipriani, Roberto; Guzman, Hector M; García, Elia

    2009-02-01

    Mining and deforestation in the early 20th century, the development of petrochemical industries during the 1950s, and the constant weathering of natural deposits of cinabrium (HgS) have made Golfo Triste, Venezuela, a region impacted by mercury (Hg). We studied the chronology of Hg in coral skeletons of Siderastrea siderea (1 colony, 1900-1996) and Montastraea faveolata (2 colonies, 1930-1999) from Parque Nacional San Esteban. Maximum values of Hg/Ca ratios and standard deviations of Hg enrichment factors occurred in the 1940s, 1960s, and 1980s, and matched maxima of decadal rainfall. Values from the 1950s and 1970s matched periods of abundant but constantly decreasing rainfall and hence were best explained by the combination of runoff and the sudden bioavailability of Hg in the region. This sudden availability likely was associated with activities of the chlorine-caustic soda and fertilizer plants of Morón petrochemical complex, industries that started producing large amounts of Hg in 1958. PMID:19012938

  3. Measles outbreak in Venezuela: a new challenge to postelimination surveillance and control?

    PubMed

    Sarmiento, Héctor; Cobo, Oswaldo Barrezueta; Morice, Ana; Zapata, Roger; Benitez, María Victoria; Castillo-Solórzano, Carlos

    2011-09-01

    The circulation of wild measles virus was interrupted in Venezuela in February 2007 after the catch-up vaccination (1994) and monitoring (1998) and in response to the measles outbreak in 2001. Traditionally, the routine coverage with measles-mumps-rubella vaccine does not exceed 85%. In February 2006, a measles outbreak started by importation in the State Miranda; this extended to 7 states and lasted 50 weeks with an intermediate period of 17 weeks without reported cases. New cases were reported in the States Guarico and Amazon. The pattern of circulation of the silent period was determined through the use of retrospective search for measles; this showed that 57% of suspected cases did not enter the surveillance system. Molecular epidemiology made it possible to identify B3 as only genotype, which also circulated in Spain. The epidemiological and clinical characteristics of measles have been modified; these determine outbreaks identified late, of slow expansion, silent, and with limited case-fatality, compared with classical outbreaks. The outbreak spread by that behavior was not recognized and the classical control measures did not result. The beginning of a broader and intense vaccination was delayed, partly by weaknesses in the sensitivity of the system. It is crucial to recognize the new behavior of measles and the effectiveness of the classical control measures, and especially to establish criteria for interruption of the circulation to control an outbreak in this stage of elimination. PMID:21954266

  4. 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.

  5. Modeling Chagas Disease at Population Level to Explain Venezuela's Real Data

    PubMed Central

    González-Parra, Gilberto; Chen-Charpentier, Benito M.; Bermúdez, Moises

    2015-01-01

    Objectives In this paper we present an age-structured epidemiological model for Chagas disease. This model includes the interactions between human and vector populations that transmit Chagas disease. Methods The human population is divided into age groups since the proportion of infected individuals in this population changes with age as shown by real prevalence data. Moreover, the age-structured model allows more accurate information regarding the prevalence, which can help to design more specific control programs. We apply this proposed model to data from the country of Venezuela for two periods, 1961–1971, and 1961–1991 taking into account real demographic data for these periods. Results Numerical computer simulations are presented to show the suitability of the age-structured model to explain the real data regarding prevalence of Chagas disease in each of the age groups. In addition, a numerical simulation varying the death rate of the vector is done to illustrate prevention and control strategies against Chagas disease. Conclusion The proposed model can be used to determine the effect of control strategies in different age groups. PMID:26929912

  6. 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

  7. Preliminary inventory of mammals from Yurubí National Park, Yaracuy, Venezuela with some comments on their natural history.

    PubMed

    García, Franger J; Delgado-Jaramillo, Mariana; Machado, Marjorie; Aular, Luis

    2012-03-01

    In Venezuela, mammals represent an important group of wildlife with high anthropogenic pressures that threaten their permanence. Focused on the need to generate baseline information that allows us to contribute to document and conserve the richness of local wildlife, we conducted a mammalogical inventory in Yurubí National Park, located in Yaracuy State in Venezuela. We carried out fieldworks in three selected vegetation types: an evergreen forest at 197m, a semi-deciduous forest ranging between 100-230m, and a cloud forest at 1 446m. We used Victor, Sherman, Havahart and pitfall traps for the capture of small non-volant mammals and mist nets for bats. In addition, we carried out interviews with local residents and direct-indirect observations for medium-large sized mammals. At least 79 species inhabit the area, representing 28% of the species recorded for the North side of the country. Chiroptera (39 spp.), Carnivora (13 spp.) and Rodentia (9 spp.) were the orders with the highest richness, as expected for the Neotropics. The evergreen forest had the greatest species richness (n=68), with a sampling effort of 128 net-hours, 32 bucket-days, 16 hours of observations, and three persons interviewed, followed by cloud forest (n=45) with 324 net-hours, 790 traps-night, 77 bucket-days, 10 hours of observations, and one person interviewed. The lowest richness value was in the semi-deciduous forest (n=41), with 591 traps-night, 15 net-hours, 10 hours of observations and three persons interviewed. Data and observations obtained in this inventory (e.g., endemism, species known as "surrogate species" threatened in Venezuela) give an important role at the Yurubí National Park in the maintenance and conservation of local ecosystems and wildlife, threatened by human pressures in the Cordillera de la Costa. PMID:22458239

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. Politics of oil in Venezuela: A decision-making analysis of PDVSA's internationalisation policy

    NASA Astrophysics Data System (ADS)

    Baena, Cesar E.

    The high degree of international vertical integration achieved by the Venezuelan state oil enterprise, Petroleos de Venezuela S.A. (PDVSA), has placed it among the most important oil multinationals (MNs). The policy of creating downstream outlets through the establishment of foreign direct investments (FDIs) in the form of refinery assets was given the term of 'internationalisation'. By analysing PDVSA's internationalisation policy, the thesis explores the difficulties encountered by a major state-owned enterprise (SOE) from a developing country in its efforts to grow beyond national borders. The study focuses on the impact of democratic bargaining on the process of oil policymaking in Venezuela, stressing the constraints posed by politics on PDVSA's efforts to expand its foreign operations. Specifically, the study examines the intricate policymaking process that shaped the origins and the development of PDVSA's internationalisation policy, underlying the events and factors that influenced each one of its three distinguishable phases: adoption, formulation, and implementation. The tensions between politics and corporate strategy are highlighted at the core of the policymaking process. The study also looks at the relationship between the oil industry and the other two key decision-making centres involved in the oil policymaking process: the executive and Congress. In exploring the ways in which each one of them sought to influence policy outcome, the study attempts to gain insight into the main factors that prompted the tensions among the policy actors involved. Three environments, or pressure-generating centres, constantly exert influence on the oil industry: the oil market, the political context and the government's financial situation. By seeking to determine the industry's response to their pervasive influence on policy formulation and implementation, this research ascertains the extent to which these variables influenced the decision-making process that characterised PDVSA's internationalisation policy. Being too powerful a company in a developing country context where the executive and the legislature find it increasingly difficult to exert their means of control over it had the effect of minimising some of PDVSA's characteristics as SOE: accountability to Congress and subordination to the executive. The thesis argues that as a result of its role as oil MN PDVSA has minimised some of its attributes as SOE. In turn, the more PDVSA has diminished its status as SOE, the more the government has increased its dependence over it. The successful accomplishment of PDVSA's internationalisation policy has stressed this equation, highlighting the contentious interaction between an excessively dependent govemment and a company struggling to reconcile its roles as both a SOE and a MN. By examining the policy process that brought about the international expansion of a large SOE from a developing country, the findings of the thesis contribute significantly to the political science and public administration literatures and suggests new paths for further research in the area of public policymaking processes. (Abstract shortened by UMI.).

  14. The role of seismic microzoning within the disaster prevention in Venezuela

    NASA Astrophysics Data System (ADS)

    Malave, G.

    2007-05-01

    Due to the experience of the strong rainfalls which experienced great parts of Venezuela in early 2005, a national commission for risk management (CNGR) was created, that is composed by representatives from the Ministry of Interior and Justice, the Ministry of Environment, Defense Ministry, Infrastructure Ministry, Habitát and Housing Ministry and Science and Tecnology Ministry. The participation of the different ministries, which are represented by institutions related to hidrometeorological research and slope stability, amongst others, enables to focuss the risk management from anintegrated point of view. Within this commission, FUNVISIS, the official agency for seismological investigations, represents the Science and Tecnology Ministry and is responsible for the actions to be taken to reduce the seismic risk. A plan to reduce the seismic hazard and vulnerability, presented by FUNVISIS, was approved by the commission, in order to establish state policies to minimize the impact to the comunities in case of the ocurrence of an earthquake. Therein, seismic microzoning studies are addressed as the methodology to follow in order to reduce the seismic risk, which includes the evaluation of regional conditions (fault ocurrences, source characteristics, attenuation) as well as the knowledge of the local conditions (wave propagation, geological conditions, site effects). The interdisciplinary methods used within the microzoning studies (joint work done by geologists, geophysicists, civil engineers, arquitects, teachers) enable to address the results of the studies in away that they can be assimilated by the communities that live in the respective urban areas as well as by the local governments. Recommendations to local buiding codes as well as training of the communities take an important part within the projects.

  15. 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.

  16. 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.

  17. 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.

  18. [Nutritional status in preschoolers attending a public day-care center in Valencia, Venezuela].

    PubMed

    Real, Sara Irene del; Jaeger, Armando Sánchez; Barón, María Adela; Díaz, Nayka; Solano, Liseti; Velásquez, Emma; López, Jesús

    2007-09-01

    With the purpose of evaluating nutritional status in a group of preschoolers attending a public day care center in Valencia, Venezuela (2002), a research was made for social stratus, anthropometric variables; weight, height and arm circumference, hemoglobin, seric retinol, presence of parasitosis and food consumption, as well as the mother's educational level. The program SPSS 11.0 and the t Student, ANOVA Post Hoc from Bonferroni and Fisher (p < 0.05) were used. A predominance of the female sex was presented (52%). According to the social stratus, 23.3% was located in the middleclass, and 76.8% on some level of poverty. 60% of the middleclass mothers had finished their high school education, while only 9.8% of the mothers in poverty had reached that level. According to the Z values (H/A, W/H and AC/H), high percentages under -1.00 were observed (27.3%, 25.6% and 24.5%, respectively). The W/H and AC/H of children of mothers studying in a university presented discrepancies when compared with children of mothers with a primary educational level. A 25.9% of anemia was presented, and there were differences between anemic and non-anemic groups for H/A and AC/H. Protozoaries were observed in 61.0%, helmintos in 16.9% and both in 22.1%. There was a 2.6 times higher risk of presenting nutritional deficiency for AC/H in the group found with parasites. An adequate consumption of energy and iron was found, with an excessive consumption of proteins and vitamin A. It is concluded that there exists a nutritional risk evaluated through hematologic parameters, the presence of parasitosis and social stratus. PMID:18271403

  19. Microbiological quality of the bivalve Pinctada imbricata commercialized in Cumaná, Venezuela.

    PubMed

    Villalobos de Bastardo, L B; Elguezabal Aristizabal, L

    2001-01-01

    The habitual consumption of oysters in the city of Cumaná, Venezuela, is made in poor sanitary conditions, therefore a study was carried out to determine the sanitary quality of the product. For this, 120 samples of oyster Pinctada imbricata were collected directly from: a) Fishing boats (unhandled samples) and b) after being shucked by the salesman (handled samples). Unhandled samples showed the following MPN/g: Faecal coliforms < 3 - 2.2 x 10, Aeromonas sp. < 3 - 1.1 x 10(3), Staphylococcus aureus < 3 - 7.5 x 10; Clostridium perfringens < 3 - 9.3 x 10); cfu/g Enterobacteriaceae 3 - 4.1 x 10(2); total aerobes 2.9 x 10(2) - 6.9 x 10(5); 6% of S. aureus were coagulase positive. Values of MPN/g of handled samples were higher: Faecal coliforms 4 - 4.6 x 10(2); E. coli 9 - 2.1 x 10(2), Aeromonas 3 - 4.6 x 10(2), S. aureus 2.3 x 10 - 4.6 x 10(2), C. perfringens < 3 - 2.8 x 10(2), and cfu/g counts of Enterobacteriaceae 5.4 x 10 - 6.5 x 10(6), total aerobes 30 - 2.8 x 10(5); 25% of S. aureus were coagulase positive. Salmonella sp. was detected in two of the handled samples. These results suggest contamination in growth areas of bivalve and during the collecting operation, which is increased by handling of the product by the salesman. PMID:11510429

  20. [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

  1. Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela

    USGS Publications Warehouse

    Garcia-Cruz, Marco A.; Lampo, Margarita; Penaloza, Claudia L.; Kendall, William; Solé, Genaro; Rodriguez-Clark, Kathryn M.

    2015-01-01

    Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.

  2. Massive bleaching of coral reefs induced by the 2010 ENSO, Puerto Cabello, Venezuela.

    PubMed

    del Mónaco, Carlos; Haiek, Gerard; Narciso, Samuel; Galindo, Miguel

    2012-06-01

    El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this work was to evaluate the massive bleaching of coral reefs in Puerto Cabello, Venezuela derived from ENSO 2010. We evaluated the bleaching of reefs at five localities both at three and five meter depth. The coral cover and densities of colonies were estimated. We recorded living coral cover, number and diameter of bleached and non-bleached colonies of each coral species. The colonies were classified according to the proportion of bleached area. Satellite images (Modis Scar) were analyzed for chlorophyll-a concentration and temperature in August, September, October and November from 2008-2010. Precipitation, wind speed and air temperature information was evaluated in meteorological data for 2009 and 2010. A total of 58.3% of colonies, belonging to 11 hexacoral species, were affected and the greatest responses were observed in Colpophyllia natans, Montastraea annularis and Montastraeafaveolata. The most affected localities were closer to the mainland and had a bleached proportion up to 62.73+/-36.55%, with the highest proportion of affected colonies, whereas the farthest locality showed 20.25+/-14.00% bleached and the smallest proportion. The salinity in situ varied between 30 and 33ppm and high levels of turbidity were observed. According to the satellite images, in 2010 the surface water temperature reached 31 degree C in August, September and October, and resulted higher than those registered in 2008 and 2009. Regionally, chlorophyll values were higher in 2010 than in 2008 and 2009. The meteorological data indicated that precipitation in November 2010 was three times higher than in November 2009. Massive coral bleaching occurred due to a three month period of high temperatures followed by one month of intense ENSO-associated precipitation. However, this latter factor was likely the trigger because of the bleaching gradient observed. PMID:23894926

  3. 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.

  4. [Imposex in Voluta musica (Caenogastropoda: Volutidae) from Northeastern Peninsula de Araya, Venezuela].

    PubMed

    Peralta, Ana Carolina; Miloslavich, Patricia; Bigatti, Gregorio

    2014-06-01

    Voluta musica is a dioecious marine gastropod endemic of the South Caribbean. Tributyltin (TBT) and copper (Cu) are potential inducers of imposex, an endocrine disorder by which females develop a penis and/or vas deferens. The goal of this work was to determine the imposex incidence in V. musica populations from Northeastern Peninsula de Araya. For this, we selected three sites (Isla Caribe, Isla Lobos and Bajo Cuspe) and made monthly samplings of 15 snails in each site, during one year, and determined: (1) sizes; (2) sex and imposex incidence and (3) the Relative Penis Length Index (RPLI). We also performed histological analysis of the gonads, and measured TBT and Cu concentrations in sediments from the studied localities. Our results showed that the total number of sampled females affected by imposex was 24.5% at Isla Caribe, 12% at Isla Lobos, and none at Bajo Cuspe. In sediments, Cu was detected mostly in Isla Lobos. The female gonads with imposex did not show any development of male cells in any of the sampled sites. The higher percentage of females with imposex matched with the higher boat traffic locality, and higher TBT level (Isla Caribe). No esterilization was evident in this work, nevertheless, the presence of TBT and Cu in the sediments and females with imposex were considered as a potential threat to V. musica populations in this region. In Venezuela there is no control over this particular issue, possibly because of the lack of information and research in this topic, but certainly, this information will be useful in biodiversity conservation policies. PMID:25102636

  5. The Boscan Field-Venezuela's giant stratigraphic trap with a complex history

    SciTech Connect

    Swanson, D.C. ); Jaimes, J.; Valdez, C.; Pirela, B.; Puche, F.; Rojas, D.; Moya, E. )

    1993-02-01

    The Boscan Field lies in the northwest quadrant of the Maracaibo Basin, Venezuela. It is a large stratigraphic trap that has produced more than 800 million barrels of heavy oil since 1946, principally from Eocene fluvial-deltaic clastic reservoirs. These are faulted, folded, and are truncated by a pre-Oligocene unconformity. The geochronology of the Boscan Field has been interpreted as follows: (1) Eocene fluvial-deltaic deposits prograded east and southeast across the Boscan Field Area. A subsiding area northeast towards the State of Falcon received tremendous quantities of Eocene fine grained organic-rich deposits in pro-delta and deep water environments. (2) The Eocene shales in the deep basin began to generate hydrocarbons which migrated towards the west and southwest. (3) In the Boscan Area, Eocene deposits were folded, faulted, and tilted towards the east and southeast and an active fluvial flood-plain truncated the deposits resulting in subcrop bands that form the pre-Oligocene unconformity topographic surface. (4) Hydrocarbon generation and migration continues in the deep basin. (5) Oligocene fluvial sandstones deposited on the underlying unconformity often cut into and are in direct contact with truncated Eocene sandstones. This allowed some oil to leak up into the Oligocene deposits. (6) By the end of the Oligocene, migration of oil into the gross Boscan trap was well underway. The east-west and northwest southeast trending fluvial conduits carried the oil out of the Eocene basin northwestward until it was blocked by reservoir truncation on the west and northwest sides of the Boscan Field. (7) Regional subsidence of the Maracaibo Basin has caused the Boscan reservoirs to dip towards the southwest resulting in realignment of fluids. The present-day Boscan Field is a composite of stacked, linear, faulted, and truncated reservoir segments. They may be isolated or interactive with other segments and form a complex [open quotes]plumbing[close quotes] tangle.

  6. White plague disease outbreak in a coral reef at Los Roques National Park, Venezuela.

    PubMed

    Croquer, Aldo; Pauls, Sheila M; Zubillaga, Ainhoa L

    2003-06-01

    Coral diseases have been reported as a major problem affecting Caribbean coral reefs. During August 2000, a coral mortality event of White Plague Disease-II (WPD-II) was observed at Madrizqui Reef in Los Roques National Park, Venezuela. This disease was identified as the major cause of coral mortality, affecting 24% of all colonies surveyed (n = 1 439). Other diseases such as Black Band Disease (BBD), Yellow Blotch Disease (YBD), Dark Spots Disease (DSD) and White Band Disease (WBD) were also recorded, but showed a lower incidence (0.14-0.97%). Two depth intervals, D1 (5.5-6.5 m) and D2 (9-9.5 m) were surveyed with two sets of three band transects 50 x 2 m long, placed parallel to the long axis of the reef. All healthy and injured corals, along each band transect, were counted and identified to species level. Additionally, all diseases and recent mortality that were still identifiable on each colony also were recorded. The incidence of colonies affected by WPD-II ranged from 12.8 to 33% among transects, where thirteen species of scleractinian corals showed several degrees of mortality. The species most affected were Montastraea annularis (39.13%), M. faveolata (26.67%), M. franksi (9.86%), Stephanocoenia intersepta (7.25%), Colpophyllia natans (6.96%), Diploria labyrinthiformis (2.99%), Mycetophyllia aliciae (2.03%), M. cavernosa (1.74%), and D. strigosa (1.45%). WPD-II was more common in the deeper strata (9-9.5 m), where 63% of the surveyed colonies were affected, although the disease was present along the entire reef. Presently, it is imperative to determine how fast the disease is spreading across the reef, how the disease spreads across the affected colonies and what the long-term effects on the reef will be. PMID:15264552

  7. [Bats (Chiroptera: Mammalia) from Yurubí National Park, Venezuela: taxonomic list and community study].

    PubMed

    Delgado-Jaramillo, Mariana; Machado, Marjorie; García, Franger J; Ochoa, José

    2011-12-01

    Bats represent a key component in the dynamics of many terrestrial ecosystems, and one of the groups of mammals with the highest levels of diversification in the Neotropics. Here we describe the results of a study of the bat fauna from Yurubí National Park (mountain area in Northern Venezuela), that includes a taxonomic list and the characterization of some community attributes in forested areas. Data was collected from zoological collections and diversified sampling methods from February to July of 2009 in an altitudinal gradient (100-1 500m), with three principal ecological units: semideciduous, evergreen and cloud forests. We recorded 64 species grouped in five families (63% of the bats known from La Cordillera de la Costa), of which Phyllostomidae was the dominant taxa (42 species; 66% of total), followed by Vespertilionidae, Molossidae, Emballonuridae and Mormoopidae. The community with the highest taxonomic diversification was found in the lowest elevation range, while the lowest number of species was found at the highest range. Eleven trophic guilds were identified; the insectivorous guild was the richest, whereas the frugivorous was the most abundant. Our results allow us to indicate these forest ecosystems have an appropriate conservation status, taking into account the presence of a relatively high proportion of species from the subfamily Phyllostominae, as well as the presence of other species with conservation priorities. All these aspects, and the fact that this represents a reservoir of the biological diversity of the forest ecosystems of La Cordillera de la Costa, make this protected area of an essential conservation value, in a highly endangered bioregion by neighboring socio-economic growth. PMID:22208091

  8. 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

  9. 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

  10. [Biovolume of some centric diatoms from the northeastern continental shelf of Venezuela].

    PubMed

    Lugo-Vizcaino, Balbina M; Díaz-Ramos, José R; Sánchez-Suárez, Isaac G

    2003-01-01

    Biovolume variation of twelve centric diatom species from eight natural habitats of the northeastem continental shelf of Venezuela were analyzed. Also, the morphometric variable that exerts the greatest influence on the biovolume was determined. Samples were collected with a net (mesh 36 microns), or with a Niskin bottle (5 l) and fixed with neutralized formaldehyde (4%). Water temperature and salinity were measured. The species studied were: Detonula sp., Skeletonema costatum, Lauderia annulata, Pseudoguinardia recta, Cerataulina pelagica, Helicotheca tamesis, Rhizosolenia styliformis, Proboscia alata, Guinardia flaccida, G. striata, Dactyliosolen fragilissimus y Leptocylindrus danicus. Forty individuals of each species from each locality were isolated and measured with a Leitz Wetzlar binocular microscope with an ocular micrometer, magnified 400X. A one-way ANOVA showed the existence of highly significant differences (p < 0.001) in the biovolume of the species regarded with its locality. These differences could be due to: (a) temporal differences in sample collection: (b) the existence of populations in different phases of their vital cycles; (c) genetic differences; (d) and differences in the physical-chemical environment at each locality. The diameter was the morphometric variable exhibiting the largest positive correlation (r > or = 0.77, p < 0.001) with biovolume for all species, except for H. tamesis. In the latter, the apical axis (or side) exhibited the best correlation with biovolume (r = 0.94, p < 0.001). The high correlation between the diameter and/or the apical axis with the biovolumen suggests that the latter could be predicted from these morphometric variables with great reliability in these species. PMID:14976780

  11. Lessons in posttraumatic stress disorder from the past: Venezuela floods and Nairobi bombing.

    PubMed

    Carlos Otero, Juan; Njenga, Frank G

    2006-01-01

    Identification and treatment of posttraumatic stress disorder (PTSD) are important following a disaster. Insights into how these aims can be achieved may be obtained from previous disasters. This article describes mental health initiatives following the 1999 flooding in Vargas State, Venezuela, and the 1998 U.S. Embassy bombing in Nairobi, Kenya. Following the Vargas State floods, a specialist mental health center devoted to the diagnosis, treatment, and follow-up of PTSD was established. Awareness and acceptance of the clinic was promoted by media campaigns and community-based activities. After 18 months, approximately 5000 people had been screened, of whom 62% were diagnosed with PTSD and treated. Moreover, the clinic's activities had expanded to include treatment of other medical conditions and assistance with nonmedical needs. Following the Nairobi bombing, a mass media campaign was initiated to create awareness of PTSD symptoms and help victims come to terms with their experience. This campaign was found to be well received and helpful. In addition, counselors were trained to support people living or working close to the blast. These examples show that mental health initiatives are feasible after a disaster and highlight a number of issues: (1) The intervention should be tailored to the needs of the target population; (2) Communication should be simple and appropriate; (3) Community-based activities are valuable in promoting awareness and acceptance of mental health initiatives; (4) Reducing the stigma often associated with mental health problems is important; and (5) The mass media can be helpful in promoting awareness of mental health issues following major trauma. PMID:16602817

  12. 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 Tovar, and last but not least, my son Johann Puerta. Without their generous help and great effort, it would have been impossible for me to organize, reach all the goals and finally, successfully realize the workshop. We are also grateful for the financial support of CLAF (Centro Latino American de Fisica), Fonacit (Fondo Nacional de Ciencia Investigacion y Tecnología), IVIC (Instituto Venezolano de Investigaciones Cientificos), Fundacion Banco Mercantil, whose sponsorship and finnacial support were vital to the realization of the event. We would like to thank La Universidad del Zulia, Universidad Central de Venezuela, Instituto Universitario de Tecnología, IDEA (Instituto de Estudios Avanzados), and Asociación de Amigos de la Universidad Simón Bolivar for their help and support in different ways for the good results we achieved in most of the meetings and the participation of their students who attend the Workshops. Finally we appreciate very much the Ministry for Science and Technology (Ministerio del Poder Popular para la Ciencia y la Tecnología) for their contribution to the workshops and to the publication process. We are under the impression that our meeting was successful, as we expected, and we are thankful for the collaboration of our Institution, and the close relation we had with all the physics researchers of Latin America and abroad (Europe, USA, Australia and Russia). Lastly, many thanks to the invited speakers for their lectures presented which have given a whole overview of the state of the art in different areas of the Physics of Plasma.

  13. 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

  14. 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

  15. Development, antibiotic production, and ribosome assembly in Streptomyces venezuelae are impacted by RNase J and RNase III deletion.

    PubMed

    Jones, Stephanie E; Leong, Vivian; Ortega, Joaquin; Elliot, Marie A

    2014-12-01

    RNA metabolism is a critical but frequently overlooked control element affecting virtually every cellular process in bacteria. RNA processing and degradation is mediated by a suite of ribonucleases having distinct cleavage and substrate specificity. Here, we probe the role of two ribonucleases (RNase III and RNase J) in the emerging 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 of this bacterium. We demonstrate a connection between the action of these ribonucleases and translation, with both enzymes being required for the formation of functional ribosomes. RNase III mutants in particular fail to properly process 23S rRNA, form fewer 70S ribosomes, and show reduced translational processivity. The loss of either RNase III or RNase J additionally led to the appearance of a new ribosomal species (the 100S ribosome dimer) during exponential growth and dramatically sensitized these mutants to a range of antibiotics. PMID:25266378

  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 β-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. [Community structure of bivalves and gastropods in roots of red mangrove Rhizophora mangle (Rhizophoraceae) in isla Larga, Mochima Bay, Venezuela].

    PubMed

    Acosta Balbas, Vanessa; Betancourt Tineo, Rafael; Prieto Arcas, Antulio

    2014-06-01

    The Rhizophora mangle roots form a complex ecosystem where a wide range of organisms are permanently established, reproduce, and find refuge. In this study, we assessed the diversity of bivalves and gastropods that inhabit red mangrove roots, in isla Larga, Mochima, Venezuela Sucre state. Bimonthly collections were made from January 2007 to May 2008, in four study areas denominated: South, North, East and West. In each area, five mangrove roots were sampled, and the specimens were obtained. We analyzed a total of 180 roots and a total of 35 bivalve species and 25 gastropod species were found. The most abundant bivalves were: Isognomon alatus, Isognomon bicolor, Ostrea equestris, Crassostrea rhizophorae and Brachidontes exustus; among gastropods, the most common where: Littorina angulifera, (Cymatium pileare and Diodora cayenensis. The months with the highest abundances and number of individuals for both groups were January and July 2007, and March 2008. The mangrove ecosystem in isla Larga, presented a number of individuals and species higher than those reported for other regions in Venezuela and the Caribbean. PMID:25102639

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

    PubMed Central

    Jones, Stephanie E.; Leong, Vivian; Ortega, Joaquin

    2014-01-01

    RNA metabolism is a critical but frequently overlooked control element affecting virtually every cellular process in bacteria. RNA processing and degradation is mediated by a suite of ribonucleases having distinct cleavage and substrate specificity. Here, we probe the role of two ribonucleases (RNase III and RNase J) in the emerging 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 of this bacterium. We demonstrate a connection between the action of these ribonucleases and translation, with both enzymes being required for the formation of functional ribosomes. RNase III mutants in particular fail to properly process 23S rRNA, form fewer 70S ribosomes, and show reduced translational processivity. The loss of either RNase III or RNase J additionally led to the appearance of a new ribosomal species (the 100S ribosome dimer) during exponential growth and dramatically sensitized these mutants to a range of antibiotics. PMID:25266378

  19. Factors associated with distribution of Anopheles aquasalis and Anopheles oswaldoi (Diptera: Culicidae) in a malarious area, northeastern Venezuela.

    PubMed

    Grillet, M E

    2000-03-01

    Spatial and temporal abundance patterns of anopheline larvae and their relationships with wetland conditions were studied in an endemic malaria area in northeastern Venezuela, where Anopheles aquasalis Curry is the main vector. Larvae were sampled over a 2-yr period in 7 wetland types (brackish and freshwater herbaceous swamps, mangrove swamps, freshwater ponds, clear-cut marsh forests, small irrigation canals, and swamp forests), covering 3 environmental gradients (salinity, aquatic vegetation, and habitat permanence). Twelve variable were quantified to describe each habitat. Two species of anophelines were collected. An. aquasalis was the species with the widest distribution, and its highest abundance was in the seasonal brackish mangrove habitat during the rainy season. An. oswaldoi Peryassu was rarely encountered, but was mainly associated with the dry season and with the permanent fresh water wetlands (such as ponds). Principal components and correlation analyses revealed that the physicochemical (salinity, dissolved oxygen) variables of the wetland were associated most strongly with the spatial distribution of both species. Variations in salinity were strongly associated with the abundance of An. aquasalis. Both the occurrence and abundance of An. oswaldoi were most closely correlated with dissolved oxygen. Changes in seasonal abundance of both species were associated with rainfall. The relevance of these results to vector control in northern Venezuela is discussed. PMID:10730493

  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. Diseases and injuries associated with travel among students, employees and teachers of the Central University of Venezuela during the national summer vacations.

    PubMed

    Risquez, Alejandro; Marrero, Aiskel; Naranjo, Niurka; Palacios, Yanine; Rossomando, Maria T; Rodriguez-Morales, Alfonso J

    2010-01-01

    The objective of this study was to describe the incidence of disease and injuries associated with travel, etiology, risk factors and medical management in a cross-sectional evaluation of university students, employees and teachers of the Central University of Venezuela, Caracas, Venezuela, who returned from domestic travel. A questionnaire completed by 500 individuals was used to evaluate the incidence of disease and injuries associated with travel, the etiology, risk factors and medical management in university students, employees and teachers of Caracas, Venezuela. From the total who accepted and responded to the interview (460, 92%), 50.8% were females. Almost half of them had some vaccination before travel for: measles 78%, rubella 73.6%, hepatitis B 57%, Yellow fever 53.7%. After travel, 53.9% of the individuals reported disease or injury related with travel, including insect bites (22%), which was reported most commonly. Occurrence of disease and injuries was higher for those who traveled to the jungle (OR=5.23, 95% CI 0.62-43.80), followed by those who travel to two areas (OR=1.82, 95% CI 1.06-3.13). Drinking alcohol during travel was identified in 73.8%, was significantly higher in men (p<0.01), and was associated with car accidents. Finally, 14.8% required medical attention during travel. The results indicated the importance of education and training in travel medicine, a relatively new medical discipline in Venezuela. Venezuela has a significant number of people visiting areas at risk for the acquisition of tropical and non-tropical conditions. Occasionally, travelers were without adequate preventive measures and pre-travel advice which is considered of utmost importance. PMID:20188305

  2. 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.

  3. [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

  4. 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

  5. Is Acropora palmata recovering? A case study in Los Roques National Park, Venezuela.

    PubMed

    Croquer, Aldo; Cavada-Blanco, Francoise; Zubillaga, Ainhoa L; Agudo-Adriani, Esteban A; Sweet, Michael

    2016-01-01

    Eight years ago (2007), the distribution and status of Acropora palmata was quantified throughout Los Roques archipelago in Venezuela. The aim was to produce a baseline study for this species which combined population genetics with demographic data. The results highlighted that A. palmata had the potential to recover in at least 6 out of 10 sites surveyed. Recovery potential was assumed to be high at sites with a relatively high abundance of the coral, low disease prevalence, high genetic diversity, and high rates of sexual reproduction. However, as noted, Zubillaga et al. (2008) realized recovery was still strongly dependent on local and regional stressors. In 2014 (this study), the status of A. palmata was re-evaluated at Los Roques. We increased the number of sites from 10 in the original baseline study to 106. This allowed us to assess the population status throughout the entirety of the MPA. Furthermore, we also identified local threats that may have hindered population recovery. Here, we show that A. palmata now has a relatively restricted distribution throughout the park, only occurring in 15% of the sites surveyed. Large stands of old dead colonies were common throughout the archipelago; a result which demonstrates that this species has lost almost 50% of its original distribution over the past decades. The majority of corals recorded were large adults (∼2 m height), suggesting that these older colonies might be less susceptible or more resilient to local and global threats. However, 45% of these surviving colonies showed evidence of partial mortality and degradation of living tissues. Interestingly, the greatest increase in partial mortality occurred at sites with the lowest levels of protection ([Formula: see text]; df = 4, p < 0.05). This may suggest there is a positive role of small scale marine management in assisting reef recovery. We also recorded a significant reduction ([Formula: see text]; df = 8; p < 0.05) in the density of A. palmata in sites that had previously been categorized as having a high potential for recovery. One explanation for this continued decline may be due to the fact that over the past 10 years, two massive bleaching events have occurred throughout the Caribbean with records showing that Los Roques has experienced unprecedented declines in overall coral cover. We therefore conclude that although local protection could promote recovery, the impacts from global threats such as ocean warming may hamper the recovery of this threatened species. PMID:26839742

  6. 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.

  7. [Dynamics of soil properties in forests of Rhizophora mangle L. (Rhizophoraceae) in Margarita Island, Venezuela].

    PubMed

    Sánchez-Arias, Luz Esther; Paolini, Jorge; Rodríguez, Jon Paul

    2010-06-01

    Biochemical and microbiological properties of soils can provide information related to ecosystems environmental status. With the aim to determine the response of microbial biomass, and enzymatic and microbial activity in hypersaline (IS > or = 55 ups) and saline (IS<55 ups) mangrove soils exposed to interstitial salinities (IS) greater than 36 ups, these properties were measured in mono-specific forests of Rhizophora mangle at Laguna de la Restinga National Park (Margarita Island, Venezuela). During three seasons (dry, wet and transition), a total of 120 soil samples were collected from ten (5 hypersaline and 5 saline) randomly-selected sites of 1000 m2 each. Four soil samples (400-500 g) per plot were randomly collected with a corer at a depth of 10 cm using a 1 m2 quadrat; each sample consisted in the combination of 8 sub-samples (50-60 g ea.). Physical, chemical, enzymatic, biochemical and microbiological properties of soil samples were determined using standard laboratory protocols. The response of microbial biomass and microbial and enzymatic activity was analyzed taking into account spatial and climatic factors and interstitial salinity. Microbial biomass was linked to each locality conditions, and was not sensitive to seasonal or salinity differences. Microbial activity remained functionally active during the study period and presented variable responses. Dehydrogenase activity proved to be a good indicator for flooded and anoxic environments, and arginine ammonification resulted to be the more sensitive microbial activity to changes in salinity. Regarding enzyme activities, spatial variability was the most widespread response. We did not find a unique general pattern between enzymatic activities and spatio-temporal variation; and only the enzyme phosphatase was negatively affected by salinity. We conclude that microbial populations of mangrove soils and their activities have functional adaptations to flooded and highly-saline environments typical of a negative estuary, subjected to drastic changes due to weather and water dynamics. Future studies are needed to determine the relation between the "health" of mangrove forest and microbial populations, and their activities in mangroves soils. PMID:20527458

  8. Shear-wave splitting in northeast Venezuela, Trinidad, and the eastern Caribbean

    NASA Astrophysics Data System (ADS)

    Russo, R. M.; Silver, P. G.; Franke, M.; Ambeh, W. B.; James, D. E.

    1996-06-01

    We present new measurements of splitting of core shear-wave phases (SKS, SKKS, PKS) recorded at seven stations in the eastern Caribbean region. Six stations in northeastern Venezuela and Trinidad constituted the SECaSA92 temporary broadband array. The seventh station, SJG, is installed on Puerto Rico. We also attempted to measure source-side splitting of S waves from earthquakes in the Lesser Antilles subducted slab, but with little success. Mean splitting parameters, fast polarization direction, ?, and delay time, ?t, at the stations are consistently east-west trending and over 1 s, respectively. Delay times at the SECaSA92 array are amongst the highest yet measured, reaching 2.1 s and generally over 1.5 s. We note an approximately linear decrease in delay times here from maxima at the northernmost stations to a minimum at the southernmost. The SECaSA92 array is situated in the wide South America-Caribbean (SA-Ca) plate boundary zone, and SJG is within the North America-Caribbean (NA-Ca) plate boundary zone. In both cases, ? trends are parallel to the plate boundary zones, locally. We interpret these results to indicate that the SA-Ca plate boundary deformation extends to depths of at least 200 km, and that South American crust, lithospheric mantle, and asthenosphere are coherently deformed. The extreme delay times we measure are probably the result of transpression in the SA-Ca plate boundary and overriding of the Lesser Antilles slab by South America: compressional flattening results in extremes of foliation development, and dextral shearing yields a strong lineation in upper-mantle olivine. By contrast, the delay time at SJG, 1.2 s, is near the global average and reflects the fact that the NA-Ca plate boundary zone is purely sinistral or includes minor transtension. We note that recent counterclockwise rotation of Puerto Rico does not apparently affect upper-mantle deformation beneath the island. We suggest that this rotation is crustal, driven by far-field sinistral shear, and partly decoupled from the mantle shear. Our results are consistent with the trench-parallel mantle flow hypothesis (Russo and Silver, 1994, Science, 263: 1105-1111) and indicate that asthenospheric mantle flow beneath the Caribbean plate is eastward, and probably drives the plate's eastward motion.

  9. 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.

  10. [Genetic structure of the population of Guarico, Venezuela, studied through isonymy].

    PubMed

    Rodríguez Larralde, A; Barrai, I

    1997-01-01

    The genetic structure of the State of Guárico, Venezuela, was studied through the distribution of surnames from individuals above 40 years of age, obtained from the register of electors. The sample studied consisted in 109,200 individuals and 14,138 different surnames. For each of the 32 counties of the State, the following estimators were calculated: percentage of the population included in surnames which appear only once (estimator A), percentage of the population included in the seven most frequent surnames (estimator B), the coefficient of consanguinity due to random isonymy (n phi ii), and Karlin and McGregors ni nu, an estimator of migration. The correlation between n phi ii and B was 0.97, indicating that 94% of the variation observed in the coefficient of consanguinity due to random isonymy is due to the seven most frequent surnames. The correlation between A and ni was 0.93, so that 86% of the variation observed in ni, is due to surnames which appear only once. On the other hand, correlations between A and B, and between n phi ii and nu were non significant (0.25 and 0.01 respectively), meaning that they are measuring different features of population structure: B and n phi ii, and v were non significant (0.25 and 0.01 respectively), meaning that they are measuring different features of population structure: B and n phi ii, isolation, and A and nu, migration. The most isolated counties of Guárico, according to n phi ii and B, are Santa Rita, Espino, El Calvario, Ortiz and Santa María de Ipire. Microdifferentiation of the State was studied through the estimation of RST, which gave a value of 0.0008. Comparing this value with those obtained in other Venezuelan States, it is found that Guárico, with Aragua and Yaracuy, are among the least differentiated States, probably because of the absence of important geographical barriers and the nearness to the Capital City of our country. PMID:9640675

  11. 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.

  12. 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

  13. Large-scale shrimp farming in coastal wetlands of Venezuela, South America: Causes and consequences of land-use conflicts

    NASA Astrophysics Data System (ADS)

    Sebastiani, Mirady; González, Sara Elena; Castillo, María Mercedes; Alvizu, Pablo; Oliveira, María Albertina; Pérez, Jorge; Quilici, Antonio; Rada, Martín; Yáber, María Carolina; Lentino, Miguel

    1994-09-01

    In Venezuela, large-scale shrimp farming began in the 1980s. By 1987, the Ministry of Environment and Natural Resources (MARNR) had received 14 proposals for approval. A developer illegally started the construction of ponds at the Píritu Lagoon in the State of Anzoátegui before the authorization process was completed. This action triggered a land-use conflict. This study identifies the causes for public protest and determines the consequences of this conflict for land-use management. The results show that public protest was based on the impacts of the partial construction of ponds. These impacts were related to direct removal of wetlands, interruption of natural patterns of surface flows, and alteration of feeding grounds of some bird species with migratory status. Consequences were identified in relation to the role that nongovernmental organizations (NGOs) play in land-use conflicts and the actions that MARNR could take in the future to prevent and solve similar situations.

  14. 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.

  15. 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

  16. 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.

  17. [Factors of virulence associated with enteropathogenicity in strains of Aeromonas spp. isolated from children with diarrhea in Mérida, Venezuela].

    PubMed

    Longa, Aurora; Vizcaya, Luisa; Nieves, Beatriz; Bravo, Laura; Morier, Luis; Pérez-Schael, Irene; Enrique Cabrera, Luis

    2005-01-01

    The feces of 397 patients with acute diarrheal disease (ADD) and of other 121 patients without diarrea (control group) were studied in the state of Mérida, Venezuela, from June 1993 to December 1994. The genus Aeromonas was identified in patients with ADD in 11.83% and in 5.78% of the patients from the control group. On studying the virulence factors described for Aeromonas (enterotoxin, cytotoxin, hemaglutinins, cellular hydrofibrosity, and hemolytic activity) in the isolated strains, it was detected that all presented at least one of the factors investigated associated with enteropathogenicity. Of the isolated species, Aeromonas caviae was the most frequently identified. All these results suggest that the Aeromonas species are potential enteric pathogens in this population. PMID:17966577

  18. 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.

  19. 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.

  20. 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.

  1. El Furrial oil field, Northeastern Venezuela: First giant in foreland fold and thrust belts of Western Hemisphere

    SciTech Connect

    Not Available

    1988-01-01

    The El Furrial giant oil field lies on the northern flank of the prolific Eastern Venezuela basin. Major tectonic elements of the region consist of a fold and thrust belt and a deep foreland basin, whose deformation is a product of right-oblique arc-continent collision. This mountain-front oil province displays parallel bands of thrusts and associated folds that extend over 150 mi and have relay trend patterns. The El Furrial structure is a long, doubly plunging anticline, flanked by imbricated, blind thrusts. Seismic data indicate vertical closure of about 3,000 ft over an area of 17,300 ac. The prospective section, of middle Tertiary to Late Cretaceous age, is mainly clastic, with an oil column of 1,800 ft. The interval of greater hydrocarbon potential is equated with shallow marine platform sandstones. Production tests reach sustained daily flow rates exceeding 9,500 bbl of 28/sup 0/API oil and 9,100 mcf of gas. Analysis of the oil suggests a marine Cretaceous source. Although in an early stage of development, the field is estimated to contain approximately 2 billion bbl of recoverable oil reserves. This places El Furrial in the forefront of the giant oil fields in the foreland fold and thrust belt provinces of the Western Hemisphere, second only to the supergiant accumulations of the Zagros zone in the Persian Gulf. The eastern Venezuela basin probably contains on the order of 2 trillion bbl of oil in place, making it the largest oil-bearing basin in the world. An ultimate recovery of 500 billion bbl is estimated. Therefore, the basin offers significant geologic scope for exploration for other giant fields.

  2. Is Acropora palmata recovering? A case study in Los Roques National Park, Venezuela

    PubMed Central

    Cavada-Blanco, Francoise; Zubillaga, Ainhoa L.; Agudo-Adriani, Esteban A.; Sweet, Michael

    2016-01-01

    Eight years ago (2007), the distribution and status of Acropora palmata was quantified throughout Los Roques archipelago in Venezuela. The aim was to produce a baseline study for this species which combined population genetics with demographic data. The results highlighted that A. palmata had the potential to recover in at least 6 out of 10 sites surveyed. Recovery potential was assumed to be high at sites with a relatively high abundance of the coral, low disease prevalence, high genetic diversity, and high rates of sexual reproduction. However, as noted, Zubillaga et al. (2008) realized recovery was still strongly dependent on local and regional stressors. In 2014 (this study), the status of A. palmata was re-evaluated at Los Roques. We increased the number of sites from 10 in the original baseline study to 106. This allowed us to assess the population status throughout the entirety of the MPA. Furthermore, we also identified local threats that may have hindered population recovery. Here, we show that A. palmata now has a relatively restricted distribution throughout the park, only occurring in 15% of the sites surveyed. Large stands of old dead colonies were common throughout the archipelago; a result which demonstrates that this species has lost almost 50% of its original distribution over the past decades. The majority of corals recorded were large adults (∼2 m height), suggesting that these older colonies might be less susceptible or more resilient to local and global threats. However, 45% of these surviving colonies showed evidence of partial mortality and degradation of living tissues. Interestingly, the greatest increase in partial mortality occurred at sites with the lowest levels of protection (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${X}_{o}^{2}=5.4> {X}_{c}^{2}=4.5$\\end{document}Xo2=5.4>Xc2=4.5; df = 4, p < 0.05). This may suggest there is a positive role of small scale marine management in assisting reef recovery. We also recorded a significant reduction (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${X}_{\\mathrm{exp}}^{2}=126.8> {X}_{\\mathrm{cri}}^{2}=15.5$\\end{document}Xexp2=126.8>Xcri2=15.5; df = 8; p < 0.05) in the density of A. palmata in sites that had previously been categorized as having a high potential for recovery. One explanation for this continued decline may be due to the fact that over the past 10 years, two massive bleaching events have occurred throughout the Caribbean with records showing that Los Roques has experienced unprecedented declines in overall coral cover. We therefore conclude that although local protection could promote recovery, the impacts from global threats such as ocean warming may hamper the recovery of this threatened species. PMID:26839742

  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. 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

  5. Integrated seismic, flexural and gravimetric modelling of the Coastal Cordillera Thrust Belt and the Guárico Basin, North-Central Region, Venezuela

    NASA Astrophysics Data System (ADS)

    Jácome, María I.; Rondón, Kenny; Schmitz, Michael; Izarra, Carlos; Viera, Ernesto

    2008-11-01

    We constructed two integrated geodynamic transects for the eastern and western areas of the Coastal Cordillera Thrust Belt and the Guárico Basin (North-Central region of Venezuela), based on information from depth-converted reflection seismic cross-sections, surface geology, Bouguer anomaly and deep refraction seismic profiling. These geodynamic transects were modelled in order to: (1) understand the geodynamic processes responsible for the formation of the Guárico Basin, (2) quantitatively determine the contribution of the Coastal Cordillera thrust sheet loading in the generation of the basin fill (i.e. the effective elastic thickness of the northern part of the South American lithosphere, the total shortening of the thrust belt and the maximum subsidence of the basin) and (3) characterize the crustal structure and Moho depth in North-Central Venezuela. We used flexural modelling to obtain important quantitative information related to the total Middle Eocene to Recent shortening of the Coastal Cordillera, the total subsidence observed in the Guárico Basin and the effective elastic thickness of the South American lithosphere in northern Venezuela. We conclude that the load of the Coastal Cordillera on the South American lithosphere is sufficient to generate the subsidence observed in the Guárico Basin. The total shortening and subsidence obtained in the western transect are 44 km and 5 km, whereas they are 10 km and 7 km, in the eastern transect, respectively. The effective elastic thickness of the South American lithosphere obtained from the modelling is 25 km. The seismically-constrained deep structure of North-Central Venezuela indicates that Moho reaches a maximum depth of 45 km under the Guayana Shield and shallows to the north, to 35 km beneath the Guárico Basin. According to the gravity models, Moho is deeper under the Coastal Cordillera Thrust Belt than expected from flexural modelling, pointing to the existence of a crustal root more than 35 km deep. The Moho gets shallower (30 km) towards the Caribbean Sea.

  6. 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

  7. 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

  8. [Vitamin A deficiency and the anthropometric nutritional status of urban and rural marginalized children in the state of Zulia, Venezuela].

    PubMed

    Amaya-Castellanos, Daisy; Viloria-Castejón, Haydée; Ortega, Pablo; Gómez, Gisela; Urrieta, Jesús R; Lobo, Pablo; Estévez, Jesús

    2002-06-01

    The present transversal study was carried out to estimate the prevalence of both vitamin A deficiency (VAD) and protein-energy malnutrition among children (24 to 85 months) from three urban slums (n = 173) in Maracaibo city, Zulia State, Venezuela and a rural slum area (n = 34), vieinal to Maracaibo, by measuring serum retinol and z score of anthropometric indices Height//Age (H//AZ); Weight//Age (W//AZ) and Weight//Height (W//HZ), compared to NCHS-WHO reference values. The Graffar's methodology adapted to Venezuela by Méndez Castellano (1986) confirmed the underprivileged socio-economic condition of the children population. For serum retinol analysis, peripheral venous blood was drawn and serum was treated according to the Bieri et al. (1979) technique and HPLC procedure. Values were recorded in microgram/dL. Statistical analysis was done by using Epi Info 2000, release 1.0 and SAS release 6.0 (1996) computer programs. The prevalence of VAD (serum retinol < 20 micrograms/dL) in the total children population (n = 207) was 22.2%, being higher in urban children than in rural children (22.5% vs 20.5%). No clinical signs of VAD were detected in the children. The nutritional status analysed by Z score of anthropometric indices revealed that 27.4% of children suffered from undernutrition (Z score = -2 to > -3 SD), being 15.4% stunted, 9.6% wasted and 2.6% with acute protein-energy malnutrition. Neither severe malnutrition nor overweight were detected. According with the H//AZ index, 54.6% of children had adequate nutrition. However 23% of them suffered from VAD. In children at risk of developing undernutrition (Z score = -1 to > -2 SD), 20.9% had VAD and of the stunted children, 21.9% presented VAD. With W//AZ, 60.3%, 29.9% and 9.1% of children were with adequate nutrition, at risk, or wasted respectively; of each group, 25.6%, 17.7% and 15%, respectively had serum retinol values below 20 micrograms/dL. The Z score of W//HZ indicator revealed that 87.4%, 10.4% and 2.4% of children were in good nutrition, at risk, or with acute protein-energy malnutrition, respectively. In the three groups 22.1%, 23.8% and 20%, respectively were affected by VAD. These results indicate that VAD coexists indistinctly in healthy, adequately nourished children, as in those malnourished ones. Our VAD prevalence results and others from Venezuela, are higher than the criteria laid down by WHO and PAHO which warrant wide community intervention. This public health problem becomes more significant because children are apparently healthy and, if timely vitamin A supplementation is not given, any intercurrent infection is likely to worsen the vitamin A status, increasing the widely known consequences. PMID:12108030

  9. 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

  10. 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

  11. Intermediate-depth seismicity in northern Colombia and western Venezuela and its relationship to Caribbean plate subduction

    NASA Astrophysics Data System (ADS)

    Malavé, Gustavo; SuáRez, Gerardo

    1995-06-01

    The recent intermediate-depth seismicity in northern Colombia and western Venezuela was analyzed to understand its origin and its presumed relationship to a subducted lithospheric slab in northwestern South America. The area included in this study is located to the north and east of the Bucaramanga nest, which is a particular region beneath Bucaramanga, northern Colombia, that presents a high concentration of intermediate-depth earthquakes. To the north of the nest, the seismicity of the area is sparse, and most of the events are of low magnitude (mb?5.l). Thus only 23 earthquakes were large enough to be investigated using teleseismic data. The focal parameters of the two largest events (mb?5.4) were obtained from the formal inversion of long-period body waves recorded at teleseismic distances. The focal mechanisms of 10 more events were determined from first-motion data. In total, the focal mechanisms of 12 events were determined from both the inversion of P and S H waveforms and the polarities of first arrivals. For the smaller earthquakes, the focal depths were calculated by measuring the observed pP-P interval, time and comparing it to the theoretical travel time tables. The isodepth curves reflect a slab striking in a NNE-SSW direction and dipping approximately at 25°-32° to the southeast. This observation is corroborated by the direction and plunge of the T axes of the focal mechanisms, which are generally parallel to the gradient of the slab defined by the spatial distribution of hypocenters. These results indicate that the intermediate-depth earthquakes in western Venezuela and northern Colombia are apparently related to the presence of a continuous lithospheric slab subducted near the northern coast of Colombia. The two largest earthquakes, located at a significant distance from the Bucaramanga nest, present similar fault plane solutions. Moreover, they also agree with those of the two largest earthquakes reported inside the nest. This similarity suggests that the Bucaramanga nest lies on the same subducted slab where the other earthquakes occur. There is not enough shallow seismicity to define the location where the Caribbean lithosphere subducted beneath the South American plate. However, the extension of the slab toward the surface, inferred from the intermediate-depth seismicity, suggests that the subducted lithosphere may still be attached to the Caribbean plate.

  12. 15. Como gatehouse (outlet tower) and access bridge, looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Como gatehouse (outlet tower) and access bridge, looking west from dam crest (Trash rack visible in reservoir pool behind and right of tower) - Bitter Root Irrigation Project, Como Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. N2O and NO emissions from soils of the Northern Part of the Guayana Shield, Venezuela

    NASA Astrophysics Data System (ADS)

    Sanhueza, Eugenio; Hao, Wei Min; Scharffe, Dieter; Donoso, Loreto; Crutzen, Paul J.

    1990-12-01

    Soil fluxes of N2O and NO were measured in a scrub grass savanna and a nearby semideciduous forest in the savanna climatic region of Venezuela, during October 1988. The forest soil produces significantly larger emissions of N2O (ranging from 5.7 to 25.0×109 molecules cm-2 s-1) than the savanna soil (-3.6 to 14.0×109 molecules cm-2 s-1). This suggests that "long-term" deforestation could produce a reduction of the N2O emissions to the atmosphere. In comparison with previous results from another site in the Venezuelan savanna region, very low emissions of NO, of the order of 1 to 2×109 molecules cm-2 s-1, were recorded. Considering that the NO/N2O emission ratio was much lower than 1, that practically no changes in the emission were observed after the fertilization with NH4Cl, and that very low concentration of NO3- is found in the natural soil, it is likely that under undisturbed conditions N2O and NO are mainly produced by denitrification and that there is a lack of nitrifying bacteria in these soils. Both N2O and NO emissions increased after application of NaNO3. Since the emission of NO remained larger than the N2O emission (with a ratio of ˜4/1), a significant change in the production pattern must have occured after fertilization with nitrate.

  19. Paleomagnetic core-orientation for characterizing reservoir anisotropy: Case histories from fractured reservoirs in Abu Dhabi and Venezuela

    SciTech Connect

    Alstine, D.R. van; Butterworth, J.E. ); Willemse, E.J.M.; Graaff, W.J.E. van de )

    1991-03-01

    Over the past decade, the authors have tested and refined the paleomagnetic core-orientation technique, they first applied on the U.S. Department of Energy's Multiwell Experiment in the early 1980s. Paleomagnetic orientation accuracy within 5{degree} is routinely achievable, as demonstrated in over 100 tests against dipmeter, seismic, borehole televiewer, and mechanical core-orientation (conventional multishot and MWD) techniques. These tests reveal that mechanical core-orientations commonly suffer from torques acting on downhole equipment and on the core. In contrast, the paleomagnetic core-orientation technique is not prone to downhole mechanical problems, uses no rigtime, is cost-effective, and can selectively orient individual core pieces, including ASR and DSCA samples. Accurate paleomagnetic orientations can be obtained even from cores drilled decades ago. In Abu Dhabi, paleomagnetically-oriented 10-year-old slabbed cores from Habshan and Dukhan carbonates yield fracture patterns consistent with the geologic structure in the Asab and Sahil fields. In Venezuela, paleomagnetic orientation of fresh and decade-old archived cores of Cogollo limestones and La Luna black shales yield fracture and bedding directions consistent with dipmeter data and outcrop observations around Lake Maracaibo. Paleomagnetic core-orientation permits access to the vast resource of reservoir-anisotropy data in previously unoriented cores in storage throughout the world. Paleomagnetic core-orientation is a versatile technique with proven accuracy, not only in vertical wells, but also in slant holes and horizontal wells.

  20. Dynamics of Black Band Disease in a Diploria strigosa population subjected to annual upwelling on the northeastern coast of Venezuela

    NASA Astrophysics Data System (ADS)

    Rodríguez, S.; Cróquer, A.

    2008-06-01

    Temporal variability of Black Band Disease (BBD) prevalence, incidence, recurrence, recovery and virulence was estimated in a Diploria strigosa population from an upwelling zone of Venezuela, for 1 year between August 2004 and August 2005. The sampling spanned both upwelling and non-upwelling seasons, and included three samplings, roughly 60 days apart, within each season. The negative effects of BBD epizootiology in the sampling population (El Mercado reef) were positively correlated with sea surface temperature (taken as an upwelling estimator). Disease prevalence, incidence and recurrence decreased significantly during upwelling, and the recovery rate increased. Contrary to expectations, tissue mortality did not decrease significantly during the upwelling season, remaining at 1.2 ± 0.7 mm day-1. BBD prevalence, and the ensuing rates of tissue mortality were higher than values previously reported for other Caribbean reefs, even during upwelling episodes, suggesting that nutrient enrichment of the local waters by upwelling counteracts the expected reductions of the disease prevalence and virulence due to the lower temperature. Colonies which had previously been infected with BBD were up to six times more susceptible to new infections than those which were not infected during the preceding 7 months, suggesting that the infected colonies never healed completely. The high variability between tissue mortality values among coral colonies also suggests that overall host health-status may alter susceptibility to BBD infections.

  1. 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.

  2. Could the Chagas disease elimination programme in Venezuela be compromised by reinvasion of houses by sylvatic Rhodnius prolixus bug populations?

    PubMed

    Sanchez-Martin, Maria J; Feliciangeli, M Dora; Campbell-Lendrum, Diarmid; Davies, Clive R

    2006-10-01

    The Andean Pact Initiative (1997) committed Andean countries to eliminate vectorial transmission of Chagas disease by 2010 via widespread residual insecticide spraying. In Venezuela, this aim could be compromised by reinvasion of houses by palm tree populations of the major vector Rhodnius prolixus. To test this hypothesis, a multivariate logistic regression was undertaken of risk factors for triatomine infestation and colonization in 552 houses and 1068 peri-domestic outbuildings in Barinas State. After adjusting for other risk factors, including palm roofs, R. prolixus infestation and colonization of outbuildings (and, to some extent, houses) was significantly associated with proximity to high densities of Attalea butyracea palm trees. House infestation and/or colonization was also positively associated with bug density in peri-domestic outbuildings, the presence of pigsties and nests. Hence, R. prolixus populations in ineffectively sprayed outbuildings could also provide an important source of house re-infestations. The secondary vector Triatoma maculata was mainly found associated with the presence of hens nesting both indoors and outdoors. PMID:17002733

  3. Evaluating oil quality and monitoring production from heavy oil reservoirs using geochemical methods: Application to the Boscan Field, Venezuela

    SciTech Connect

    Kaufman, R.L.; Noguera, V.H.; Bantz, D.M.; Rodriguez, R.

    1996-08-01

    Many oil fields worldwide contain heavy oil in one or more reservoir units. The low gravity of these oils is most frequently due to biodegradation and/or low maturity. The challenge is to find ways to economically recover this oil. Methods which reduce the operating costs of producing heavy oil add significant value to such projects. Geochemical techniques which use the composition of the reservoir fluids as natural tracers offer cost effective methods to assist with reservoir management. The low viscosity and gravity of heavy oil, combined with frequent high water cuts, low flow rates, and the presence of downhole artificial lift equipment, make many conventional production logging methods difficult to apply. Therefore, monitoring production, especially if the produced oil is commingled from multiple reservoirs, can be difficult. Geochemical methods can be used to identify oil/water contacts, tubing string leaks and to allocate production to individual zones from commingled production. An example of a giant heavy oil field where geochemical methods may be applicable is the Boscan Field in Venezuela. Low maturity oil, averaging 10{degrees} API gravity, is produced from the Eocene Upper and Lower Boscan (Miosa) Sands. Geochemical, stratigraphic and engineering data have helped to better define the controls on oil quality within the field, identified new reservoir compartments and defined unique characteristics of the Upper and Lower Boscan oils. This information can be used to identify existing wells in need of workovers due to mechanical problems and to monitor production from new infill wells.

  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. 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.

  6. 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.

  7. 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.

  8. 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

  9. [Risk indicators of vitamin A deficiency in children younger than 15-years old from a slum area of Valencia, Venezuela].

    PubMed

    Páez Valery, María Concepción; Solano, Liseti; Del Real, Sara

    2002-03-01

    Subclinical vitamin A (VA) deficiency is difficult to assess since there is not a single suitable indicator for every situation. With the objective of assessing VA status in a vulnerable group, 590 healthy children (< 15 years of age) from a low-income community of Valencia, Venezuela, were studied. VA intake was assessed through 24 hour dietary recalls, risk of VA intake deficiency was assessed following the IVACG methodology, VA status was assessed through serum retinol levels (HPLCr) and Conjunctival Impression Cytology (CIC) according to ICEPO methodology. The sample was characterized by age (less than 7 years old, from 7 to 10 years old, and 11 years old or older). Descriptive statistics and non-parametric tests (Mann Whitney, X2) were performed. According to IVACG, 0.6% were at high risk of deficiency, 8.8% had moderate risk and 90.6% had low risk. Results from serum retinol showed 0.7% of deficiency (< 20 micrograms/dl), and 25.1% of low levels (20-30 micrograms/dl); according to CIC, 11.1% of the sample was deficient. No relationship was found by age or sex. These prevalences identify the VA deficiency as a mild public health problem. Although there was no deficiency per se (< 10 micrograms/dl), this group has a higher vulnerability to infectious diseases since 25% of the sample showed low levels of serum retinol and 11.1% showed abnormalities in its epithelial cells. PMID:12214541

  10. 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.

  11. [Changes in tobacco use and related factors in Junior High School students, Lara State, Venezuela, 2000-2003].

    PubMed

    Granero, Ricardo; Sánchez, Magda

    2006-09-01

    The Global Youth Tobacco Survey (GYTS) is a school-based surveillance system. In Lara State, Venezuela, it was conducted by a coalition of organizations. The instrument includes: attitudes, knowledge, behaviors, exposure to environmental tobacco smoke, mass media, and marketing. Participation was 85.7% in 2000 and 79.3% in 2003. Comparing prevalence (%) from 2000 to 2003: "first contact": unchanged (22.8%); "males having first cigarette before the age of 10": decreased (21.5% to 16.7%); "current cigarette smoker": unchanged (8.4% to 8.3%); "male smokers wanted to quit": increased (62.6% to 84.7%); "exposure to environmental tobacco smoke": increased (43.9% a 50.7%), "support ban on smoking in public places": unchanged (> 80%), "received free promotional cigarettes": increased (9.5% a 13.4%), and "no problem buying cigarettes": decreased in males (97% to 74.3%) and in females (95.9% to 90.3%). Tobacco use has remained unchanged, a situation attributed in part to marketing, including free cigarettes, and lack of law enforcement. GYTS provides evidence to support the design, implementation, and monitoring of policies and programs aimed at the prevention and control of tobacco use among adolescents. PMID:16917586

  12. 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.

  13. [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

  14. 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.

  15. 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.

  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. 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

  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. Effect of environmental disturbance on the population of sandflies and leishmania transmission in an endemic area of Venezuela.

    PubMed

    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

  20. [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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius) at the El Frío Biological Station, Venezuela

    PubMed Central

    Alda, Fernando; Mårtensson, Dick; Hailer, Frank; Castroviejo-Fisher, Santiago; Ginsberg, Joshua R.; Castroviejo, Javier; Doadrio, Ignacio; Vilá, Carles; Amato, George

    2016-01-01

    The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius) has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El Frío Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El Frío Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%), leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El Frío Biological Station, Venezuela. PMID:26982578

  6. Prevalence and risk factors associated with the metabolic syndrome and dyslipidemia in White, Black, Amerindian and Mixed Hispanics in Zulia State, Venezuela.

    PubMed

    Florez, Hermes; Silva, Eglé; Fernández, Virginia; Ryder, Elena; Sulbarán, Tulio; Campos, Gilberto; Calmón, Gustavo; Clavel, Emilio; Castillo-Florez, Sumaya; Goldberg, Ronald

    2005-07-01

    Studies have highlighted the association between insulin resistance (IR) and several cardiovascular (CV) risk factors, including hypertension (HTN), obesity, dyslipidemia (i.e. high triglyceride and low HDL-cholesterol) and glucose intolerance, in a cluster known as the metabolic syndrome (MS). There are few data on the frequency of the MS and dyslipidemia in developing countries, and none in South America. To estimate the prevalence of the MS and its components in Zulia State, Venezuela, and to establish associated demographic and clinical factors, we evaluated 3108 Hispanic men and women aged 20 years or older from a cross-sectional survey of a random representative sample from each health district in Zulia State, Venezuela (1999-2001). Prevalence of the MS and dyslipidemia was defined according to the National Cholesterol Education Program (NCEP)/Adult Treatment Panel III (ATP III) criteria. The age-adjusted prevalence of MS and dyslipidemia was 31.2% and 24.1%, respectively, with higher rates in men than in women. Prevalence rates increased with age and with the degree of obesity. MS prevalence was lower in Amerindian (17.%) compared to Black (27.2%), White (33.3%) and Mixed (37.4%) men, but no differences were found among women. Overall, low HDL-cholesterol (65.3%), abdominal obesity (42.9%) and HTN (38.1%) were the most frequent MS components. After adjusting for age, sex and race groups, family history of diabetes, obesity and HTN were associated with the MS. Sedentary lifestyle also increased the risk of MS, event after adjusting for the same covariates, obesity and the degree of IR. These results suggest that MS is found in approximately one-third of the Venezuelan adult population in Zulia State, with higher prevalence in men related to the presence of dyslipidemia. Lifestyle interventions in MS subjects are needed in Venezuela to halt the burden of CV disease and diabetes. PMID:15955388

  7. Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius) at the El Frío Biological Station, Venezuela.

    PubMed

    Rossi Lafferriere, Natalia A; Antelo, Rafael; Alda, Fernando; Mårtensson, Dick; Hailer, Frank; Castroviejo-Fisher, Santiago; Ayarzagüena, José; Ginsberg, Joshua R; Castroviejo, Javier; Doadrio, Ignacio; Vilá, Carles; Amato, George

    2016-01-01

    The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius) has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El Frío Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El Frío Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%), leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El Frío Biological Station, Venezuela. PMID:26982578

  8. Estimation Of Evapotranspiration From Satellite-Based Surface Energy Balance Models For Water Management In The Rio Guarico Irrigation System, Venezuela

    NASA Astrophysics Data System (ADS)

    Trezza, R.

    2006-08-01

    This paper explores the feasibility of the use of two energy balance models for the estimation of evapotranspiration from satellite data in a large irrigated area. The Rio Guarico irrigation system is located in the State of Guarico in Venezuela. A large water reservoir stores the water coming from the Guarico River and provides water for irrigation to an area of near 60,000 hectares. Rice is the main crop grown in the area. One of the models used in this study was SEBAL (Surface Energy Balance Algorithm for Land), which is an image-processing model for calculating evapotranspiration (ET) as a residual of the surface energy balance. SEBAL was developed in the Netherlands by Bastiaanssen and has been applied in many developing countries. SEBAL uses satellite data collected by the LANDSAT Thematic Mapper (TM) or other satellite sensors collecting visible, near-infrared and thermal infrared radiation. The main advantage of SEBAL is the need of a minimum amount of ground data. The second model applied was METRIC (Mapping Evapotranspiration at high Resolution and with Internalized Calibration) developed by the University of Idaho in the United States. METRIC has its foundation on SEBAL. A unique feature of METRIC is that an internal calibration is performed within every satellite image using the alfalfa reference evapotranspiration as an indicator of evaporative behavior of suspected well-irrigated full cover agricultural pixels. The results suggest that both models can be considered as operational and feasible methods to predict actual ET and improve water management on irrigated lands in Venezuela. However, limited and poorly-distributed weather information might represent a major constraint for the use of the METRIC model in Venezuela, and a source of error for the SEBAL model when data needs to be extrapolated in time.

  9. [Description of an acidic peptidase, insensitive to classical inhibitors, in protein extracts of Trypanosoma cruzi, from a rural area of Venezuela, where Chagas disease is endemic].

    PubMed

    Zambrano, Edgar Armando; de la Cruz, Henry Samuel; Coita, Blanca Elena

    2013-09-01

    Through two peptidase assay methods, one in liquid-phase and another, in gel-phase (gel zymography), an acid peptidase was detected in protein crude extracts of epimastigotes of Trypanosoma cruzi, from a rural area of Venezuela where Chagas disease is endemic. The peptidase shows activity at a pH range between 2.0 and 2.9. Under the experimental conditions described, the acid peptidase was insensitive to usual concentrations of peptidase inhibitors of the types: serine, cysteine, aspartic and metallopeptidases. Nevertheless, like porcine pepsin at pH 2.9, the peptidase was inhibited in the presence of 5mM DTT. PMID:24354241

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. [Epidemiologic and molecular study of Entamoeba histolytica and Entamoeba dispar strains in pacients with diarrhea in Cumana, Sucre state, Venezuela].

    PubMed

    Mora, Leonor; García, Ana; De Donato, Marcos; Urdaneta, Haideé

    2008-06-01

    An epidemiological and molecular study on E. histolytica and E. dispar was carried out in 428 patients with gastrointestinal symptomatology of diarrhea from different health centers in Cumana, Sucre state. The samples were processed through: direct examination with 0.85% physiological saline solution, temporal lugol staining, trichromic staining and the Ritchie method of concentration; a sucrose gradient was used for cyst isolation. The small subunit of the 16S RNA was amplified by nested, multiplex PCR for the molecular detection. The E. histolytica/E. dispar prevalences according to the direct, Ritchie and trichromic staining methods were 20.09, 13.79 and 12.15%, respectively; while prevalences according to PCR for E. histolytica and E. dispar were 6.31% and 4.44%, respectively, also detecting four cases of mixed infection. Sequencing of the amplified fragments of E. histolytica showed 100% homology with the sequences with strains from Merida (Venezuela), USA, Brazil, Mexico and GenBank. The infections by E. histolytica and E. dispar were statistically associated with age but not with sex. The presence of mucus, blood and abdominal pain were only associated to E. histolytica infection. The moderate prevalence of E. histolytica shows the endemic status of this population and warns about the potential problem as a morbidity and mortality in Sucre state. The frequency of E. dispar in this population suggests the existence of an overestimation problem in the diagnosis of amoebiasis with its clinical and epidemiological implications, and shows the poor knowledge about the true prevalences of this protozoan. The PCR allowed for the differential identification of E. histolytica and E. dispar, as well as the presence of mixed infections, making a great tool for epidemiological amoebiasis studies. PMID:18717268

  17. 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

  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. 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.

  20. Revised seismic history of the El Pilar fault, Northeastern Venezuela, from the Cariaco 1997 earthquake and recent preliminary paleoseismic results

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A.

    2007-07-01

    In light of the July 9, 1997, Cariaco earthquake, it is clearly understood now that damage in the city of Cumaná located in northeastern Venezuela and frequently destroyed by the largest earthquakes since the first recorded event in 1530 is strongly enhanced by poor soil conditions that, in turn, are responsible for site amplification and widespread earthquake-induced effects. Therefore, most previous macroseismic studies of historical earthquakes must be revaluated because those localized high-intensity values at Cumaná surely led to the misestimation of past epicenters. Preliminary paleoseismic results, gathered at three exploratory trenches dug across the surface break of the Cariaco 1997 earthquake in 1998, allow us to associate the 1684 earthquake with this recently ruptured fault segment that extends between the towns of San Antonio del Golfo and Río Casanay (roughly between the two gulfs of Cariaco and Paria, state of Sucre). Other major results from the reassessment of the seismic history of this fault are: (a) the 1766 event seems to have generated in a different source to the El Pilar fault because the size of the felt area suggests that it is an intermediate-depth earthquake; (b) damage to Cumaná produced by the 1797 event suggests that this was a local earthquake, perhaps equivalent to the 1929 earthquake, which ruptured for some 30 km just east of Cumaná into the Gulf of Cariaco; and (c) seismogenic association of the 1530 and 1853 earthquakes still remains unclear but it is very likely that these ruptures occurred offshore, as suggested by the rather large tsunami waves that both events have generated, placing their hypocenters west of Cumaná in the Cariaco Trough. This reassessment also sheds light into the El Pilar fault segmentation and the behavior of its seismogenic barriers through time.

  1. 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

  2. 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

  3. 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.

  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. 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

  6. 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).

  7. [Disease in scleractinian corals: a new problem in the reef at Cayo Sombrero, Morrocoy National Park, Venezuela?].

    PubMed

    Cróquer, Aldo; Bone, David

    2003-06-01

    At the beginning of 1996 coral reefs in Morrocoy National Park, Venezuela, suffered an unprecedented mass mortality event. As a consequence, live coral cover dropped to 2-10%. One of the few reefs that kept live coral cover over 35% was Cayo Sombrero; nonetheless, the presence of some coral diseases has been detected within the past 2 years, representing a new source of coral mortality. Due to this situation, this study started a monitoring program on the incidence of coral diseases and syndromes in the reef of Cayo Sombrero. The CARICOMP protocol was used in order to evaluate reef health. Ten parallel band-transects (20 x 2m) where established at two depth intervals: Five between 3-8 m and five between 8-12 m, and the frequency of both, healthy and unhealthy colonies of each coral species was recorded along each band transect. In addition to other sources of coral damage (predation, siltation, etc), significant differences in disease incidence between the two depths intervals were tested with a Kruskall-Wallis test. The main problems observed were coral diseases such as yellow band (4.2%), dark spots (1.61%) and white plague-II (1.4%), mainly affecting Montastraea faveolata, M. annularis and Siderastrea siderea. Siltation, affecting massive colonies, such as Colpophyllia natans and Diploria strigosa; algae overgrowth, predation, anchor damage, and bleaching. Significant differences were found in the incidence of unhealthy (Kruskall-Wallis, p < 0.05) bleached (Kruskall-Wallis, p < 0.05) and colonies affected by siltation (Kruskall-Wallis, p < 0.05). More than 60% of the 585 coral colonies surveyed at both depths were found to be healthy, indicating that the Cayo Sombrero reef is still in good conditions compared to other localities in the Park. This study stresses the need to conduct early monitoring programs that survey coral disease incidence as a source of mortality for this coral reef. PMID:15264568

  8. [Genetic diversity of rotavirus group a: correlation between G3 type and severity of the infection. Valencia, Venezuela].

    PubMed

    González, Rosabel; Rivero, Lisbeth

    2013-03-01

    Genetic and antigenic rotavirus (RV) variabilities may have implications in the severity of the infection caused by these agents; however the studies are not conclusive. For that purpose, the mean severity scores of diarrhea episodes caused by RV types G1 and G3 were compared, at Ciudad Hospitalaria "Dr. Enrique Tejera" in Valencia, Venezuela, between 2001-2005. RV were identified by ELISA, G and P types by RT-PCR. The severity of infection was determined using the Ruuska-Vesikari system and the mean severity values were compared using the Student's t-test (two-tailed, 95% CI). RV were detected in 24.5% of patients (3193/13026), being G3 the most common (50.3%), followed by G1 (39.2%), G9 (6.2%), G2 (0.6%), G4 (0.6%) and of mixed infection 3.1% (G1 + G3). Type P[8] was present in 87.3% of samples, 10.9% P[4] and 1.8% P[6]. There were not statistically significant differences (P > or = 0.05) observed between the episodes caused by G1 and G3 when age, breast feeding, and degrees of malnutrition and dehydration were considered. Nevertheless, in the G3 positive group, fever, episodes of more than 6 days, 6 or more evacuations in 24 hours and 3 or more days with vomit, were observed. The mean severity score for the G3 episodes (11.1) was significantly higher (P < 0.05) than for G1 (7.8). These results show that G3 was associated with severe diarrhea, supporting the hypothesis that the knowledge of the variability and frequency of viral types is essential to measure the impact of an anti-rotavirus vaccine. PMID:23781711

  9. 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

  10. 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

  11. 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?

  12. 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.

  13. [Bioecological characteristics of earthworm populations (Oligochaeta: Glossoscolecidae) in a natural and a protected savanna in the central Llanos of Venezuela].

    PubMed

    Hernández, Luis; Ojeda, Alonso; López-Hernández, Danilo

    2012-09-01

    In tropical savannas, the earthworm communities have a predominant role since they regulate the soil structure and dynamics of the organic matter. To study the effect on earthworm populations in two differently managed savannas, we compared the general aspects of the biology and ecology of earthworm populations from a 40 years protected savanna (SP) with no fire or cattle raising at the Estaci6n Biol6gica de los Llanos, Venezuela (EBLL), and a natural savanna (SNI), under normal burning and cattle raising management conditions. Sampling was carried out at the end of the dry season (April), and at the peak of the wet season (July-August). The main physical properties of soils per system were estimated. In each system, in plots of 90x90m, five fixed sampling units were selected at random; and at each sampling point one soil monolith of 25x25x30cm was collected per unit. Earthworms were extracted using the hand sorting extraction method; and the flotation method was used to estimate the density of cocoons. The earthworms were classified in different ecological categories considering their pigmentation, size and depth profile distribution. As a result of the savanna protection, physical parameters were modified in relation to SNI. The SP soils had higher soil moisture when compared to SNI. Soil moisture varied with depth during the dry season since, after the start of the rainy season, the soil was saturated. Field capacity in the SP was greater than that in the SNI. The surface apparent bulk density of soil was lower in the SP respect SNI, reflecting a lower soil compaction. Total average for the density and biomass of earthworms differed greatly, showing higher values in the SP. The earthworm density average in SP ranged between 25.6-85 individuals/m2 and the average biomass between 6.92-23.23g/m2. While in SNI, earthworms were only found in August, with a mean density of 22.40individuals/m2 and a mean biomass of 5.17g/m2. The vertical distribution pattern was only analyzed for the SP, and as in the SNI, no earthworms were found during the dry season; in the SP, a migration of earthworms to deeper layers during the dry season was observed; while in the rainy season they moved to upper soil layers to feed. The systems were characterized by abundance in juvenile Glossoscolecidae family earthworms which might be included in the endo-anecic ecological category. Results suggest that savanna agricultural management can modify an important fraction of pedofauna, particularly their earthworm communities, by modification of soil properties. PMID:23025092

  14. 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.

  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. 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.

  17. [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

  18. 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

    Caballer, Manuel; Ortea, Jesus; Narciso, Samuel

    2011-01-01

    Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensissp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicolasp. n.Rissoella morrocoyensissp. 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 venezolanicolasp. 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

  19. 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.

  20. Sighting frequency and relative abundance of bottlenose dolphins (Tursiops truncatus) along the northeast coast of Margarita Island and Los Frailes Archipelago, Venezuela.

    PubMed

    Oviedo, Lenin; Silva, Noemi

    2005-01-01

    The study of local cetaceans in Venezuela has a very recent history, and few efforts have been made in the assessment of coastal populations based on field research. The occurrence of whales and dolphins along the northeast coast of Venezuela has been documented through sightings and stranding records. Given the underwater topographical features and the influence of upwelling processes, this area is considered a very productive coastal ecosystem. Our objective was to establish the sighting frequency and relative abundance of bottlenose dolphins in the area. Sighting records were gathered on bottlenose dolphins and other cetacean species occurring along the northeast coast of Margarita Island and Los Frailes Archipelago through direct observation during land-based (6 surveys, 48 hours of observation) and boat-based surveys (24 surveys, 121 hours of observation, 1295 km covered). A sighting frequency was calculated using two methodologies and then compared, considering: 1) a mean effective observation time (4.27 hours), and 2) distance covered with cetacean sightings (1108 kin). A third method is proposed relating a mean effective distance covered with cetacean sightings and expressed as a percentage. The abundance index was calculated using the mean effective observation time. The sighting frequency of Tursiops truncattus in the study area was 3 - 4 sightings per day of 4.27 observation hours, or by 185 kilometers covered. The relative abundance was calculated as 35 dolphins in the study area, so a total population of less than 60 dolphins could inhabit the proposed range. Tursiops truncatus is the dominant species in the northeast coast of Margarita Island and Los Frailes Archipelago with 70% of all the sightings, so this locality could be termed as the distribution range of a possible local population of bottlenose dolphins. PMID:17354467

  1. Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

    PubMed Central

    Bush, Matthew J.; Bibb, Maureen J.; Chandra, Govind; Findlay, Kim C.; Buttner, Mark J.

    2013-01-01

    ABSTRACT WhiA is a highly unusual transcriptional regulator related to a family of eukaryotic homing endonucleases. WhiA is required for sporulation in the filamentous bacterium Streptomyces, but WhiA homologues of unknown function are also found throughout the Gram-positive bacteria. To better understand the role of WhiA in Streptomyces development and its function as a transcription factor, we identified the WhiA regulon through a combination of chromatin immunoprecipitation-sequencing (ChIP-seq) and microarray transcriptional profiling, exploiting a new model organism for the genus, Streptomyces venezuelae, which sporulates in liquid culture. The regulon encompasses ~240 transcription units, and WhiA appears to function almost equally as an activator and as a repressor. Bioinformatic analysis of the upstream regions of the complete regulon, combined with DNase I footprinting, identified a short but highly conserved asymmetric sequence, GACAC, associated with the majority of WhiA targets. Construction of a null mutant showed that whiA is required for the initiation of sporulation septation and chromosome segregation in S. venezuelae, and several genes encoding key proteins of the Streptomyces cell division machinery, such as ftsZ, ftsW, and ftsK, were found to be directly activated by WhiA during development. Several other genes encoding proteins with important roles in development were also identified as WhiA targets, including the sporulation-specific sigma factor ?WhiG and the diguanylate cyclase CdgB. Cell division is tightly coordinated with the orderly arrest of apical growth in the sporogenic cell, and filP, encoding a key component of the polarisome that directs apical growth, is a direct target for WhiA-mediated repression during sporulation. PMID:24065632

  2. 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

  3. Recent DDT and PCB contamination in the sediment and biota of the Como Bay (Lake Como, Italy).

    PubMed

    Bettinetti, R; Quadroni, S; Boggio, E; Galassi, S

    2016-01-15

    Due to its peculiar geographical and morphological characteristics, Lake Como (Northern Italy) represents an interesting study-case for investigating the sub-basin scale circulation of persistent organic pollutants (POPs) that, despite being banned since the 1970s, have reached surprisingly high concentrations in some southern alpine lakes as a consequence of their release from melting glaciers in recent years. In particular, the Como Bay, which is located in the city of Como, seems noteworthy because its waters have a longer residence time than the other areas of the lake. The analyses of the historical concentration of PCBs, pp′DDT and its metabolites in a sediment core sampled from the Como Bay covering a time-period from their ban to recent times, showed that the DDTs have never experienced a significant (p < 0.05) decrease over time, with concentrations of the most abundant homologue, pp′DDE, ranging from 27 to 75 ng g(-1) d.w. Conversely PCBs significantly (p < 0.05) decreased towards recent times, reaching concentrations around 80 ng g(-1) d.w. The contribution of high altitude and local sources was recorded also in the food web: both zooplankton and the zooplanktivorous fish agone were mainly contaminated by pp′DDE (81.4 ng g(-1) w.w. and 534.6 ng g(-1) w.w. respectively) and by the PCB metabolite hexa-CB (449.7 ng g(-1) w.w. and 1672.1 ng g(-1) w.w. respectively). The DDT concentrations in the agone (sampled during the years 2006–2009) never exceeded the limits for human consumption in Italy, while concentrations of six selected PCBs exceeded human health advisory recommendations in one of the fish samples analysed, when it was approximately two times higher than the recommended value of 125 ng g(-1) w.w. PMID:26520265

  4. Exhumation of high-pressure Metamorphic rocks along the coast of Venezuela: Insights from BOLIVAR Seismic Reflection and Refraction Data

    NASA Astrophysics Data System (ADS)

    Magnani, M.; Mann, P.; Zelt, C. A.; Levander, A.; Ave Lallemant, H.

    2006-12-01

    A 120-km-wide belt of metamorphic rocks called the Cordillera de la Costa belt extends as a steep-sided, 2- 2.5-km-high range for 700 km along the northern coast of South America from the Bocono fault to the northeastern tip of Trinidad. This belt has been subdivided into two sub-belts of Mesozoic and early Tertiary rocks: the Coastal Range/Margarita belt consisting of rocks of oceanic affinity locally at blueschist metamorphic grade and the Cordillera de la Costa belt sensu strictu consisting of continentally-derived rocks at HP/LT metamorphic grade locally containing eclogite bearing assemblages. These two metamorphic belts are inferred to have sutured together and to the South American craton to the south by oblique collision of the Caribbean arc in Eocene to Miocene time. This oblique collision culminated in the present-day, right-lateral, continental strike-slip plate boundary (Moron-El Pilar fault zone) that defines the linear topographic and lithologic boundaries of the Coastal Range/Margarita belt. In order to better understand the obduction and topographic uplift of these metamorphic terranes, the BOLIVAR seismic experiment acquired four wide-angle offshore-onland transects across the Cordillera de la Costa belt separated by 100-250 km. The offshore segment of the transects in the Bonaire basin north of Venezuela include coincident, deep-penetration seismic reflection lines. The offshore data shows that the Bonaire basin is a rift structure of Paleogene age; the main grain of normal faults is roughly NW-SE with a minor E-W trend, parallel to the present-day. Normal faults 30-70 km from the coast were inverted in late Neogene time and show large overlying fold structures. Refraction profiles crossing the Coastal Range/Margarita belt show discrete, high-velocity (>6.5 km/s) bodies at upper and mid-crustal depths (3-15 km) that are correlated to high-density serpentinized peridotites and other oceanic-derived rocks mapped at the surface. We propose that these rocks form the footwall of a strike-slip inverted normal fault similar to those imaged offshore in the Bonaire basin. The main suture zone of the metamorphic rocks with the back-arc basin rocks to the north and the continental margin rocks to the south therefore appears to be a steep, ~30 degree dipping fault presently characterized by right-lateral strike-slip motion. This fault is transpressional since its trend is about 5-10 degrees oblique to the GPS-derived direction of South America-Caribbean motion. This component of transpression, perhaps acting on preexisting normal faults appears to be the mechanism for the narrow elongate uplift of metamorphic rocks of the Cordillera de la Costa belt. We suggest that the exhumation of the HP/LT complexes occurred in two stages: 1) arc parallel extension resulting from oblique collision uplifted the metamorphosed units from deep in the subduction zone to mid crustal depths; 2) obduction and emplacement from the midcrust to the surface was accommodated by transpression, possibly along preexisting normal faults. This last mechanism appears to play an important role in the final exhumation of the complexes as the seismic data image the velocity anomalies only in those portions of the strike-slip boundary which are presently under compression.

  5. 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 μg/m3 whereas in urban areas the range was 0.21 to 1.09 μg/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.

  6. [Environmental evaluation near a fuel vendor within Parque Nacional Morrocoy, Venezuela. II: Water quality, sediments and biota].

    PubMed

    Rada, M; Losada, F

    2000-12-01

    This paper is the second part of a base line study carried out in the coastal region near a marine service station located in Morrocoy National Park, Venezuela. Results from a physical and chemical characterization of the water and sediments of four sites located around the service station are presented. The physical and chemical factors measured in water included: temperature, salinity, specific conductance, dissolved oxygen, saturation percentage of dissolved oxygen, pH, total suspended solids, transparency, oil and grease, total residual petroleum hydrocarbon, vanadium and lead, total coliform bacteria, and the presence of coliform bacteria. The factors measured in sediments include: granulometry, organic material, total carbonates, vanadium, lead, oil and grease, and total hydrocarbons. In addition, the amount of vanadium and lead in sample tissue from three species which are abundant and widely distributed in each site was measured in order to evaluate the potential of these species as bio-indicators. The water in the area where this study was conducted is shallow, warm, and thermally homogeneous, with high salinity and normal pH and dissolved oxygen, and supersaturated with oxygen in certain hours in sites adjacent to abundant underwater vegetation. The water is moderately turbid with a tendency towards less dissolved oxygen with increased depth. The estimated values of NMP/100 ml of the coliform fecal organisms is within legal limits even though the total number of water coliforms measured in Site 2 was ten times higher than in Site 1. This increase is associated with the proximity of Site 2 to an outflow of pre-treated sewage. The values of TRPH in the water collected from each site were low and very close to the detection limit (0.8/ml). Vanadium was not found, while lead was detected in 11 of the 12 samples. Compared to the values measured for Site 1, which was the local reference, only one sample had a concentration of three times the maximum baseline. The amount of lead found in all analyzed samples was acceptable, according to the standards set by the State of Washington (maximum value: 292 mg/kg), while the concentration of lead in the sediments around the supply dock were 1.5 to 3.4 times greater than the Dutch norm. It can be concluded that there is no evidence of an accumulation of Va or Pb in the species selected as bioindicators. An observation program is proposed in which variables similar to those measured for this characterization will be studied with some modifications. A more intense sampling of some variables is recommended (lead in water and sediments, total coliform and fecal matter in consecutive samples and in days following a high concentration of visitors) as is the elimination or minimization of other variables. PMID:15266791

  7. 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

  8. 78 FR 36163 - Bitterroot National Forest, Darby Ranger District, Como Forest Health Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ...The USDA Forest Service, Bitterroot National Forest will prepare an environmental impact statement (EIS) to document and disclose the effects analysis of the proposed Como Forest Health Project (Como FHP). The Como FHP covers approximately 5,640 acres of national forest land between Lake Como and Lost Horse Roads, about XX miles northwest of Darby in Ravalli County, Montana. The purpose of the......

  9. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

    ... the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit ... x 225 kilometers and use data from blocks 81 to 83 within World Reference System-2 path 8. MISR was built and is managed by NASA's ...

  10. 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)

  11. Morphological investigation of nanostructured CoMo catalysts

    NASA Astrophysics Data System (ADS)

    Pawelec, B.; Castaño, P.; Zepeda, T. A.

    2008-04-01

    This work reports the morphological investigation of nanostructured sulfided CoMo catalysts by means of high-resolution transmission electron microscopy (HRTEM). The catalysts were supported on Ti-modified hexagonal mesoporous silica (HMS-Ti) and P-modified HMS-Ti (P/HMS-Ti) materials. The oxide precursors were characterized by specific surface area (S BET), temperature-programmed reduction (TPR), diffuse reflectance infrared Fourier transform spectroscopy in the OH region (DRIFTS-OH) and X-ray photoelectron spectroscopy (XPS) in order to elucidate the influence of the impregnation sequence (successive vs. simultaneous) and the effect of P-incorporation into HMS-Ti material on the morphology of calcined CoMo catalysts. Both TPR and XPS measurements indicate that the catalysts prepared by successive impregnation possess well-dispersed MoO 3 and CoO phases, whereas their counterparts prepared by simultaneous impregnation additionally possess the CoMoO 4 phase. For all sulfided catalysts, the presence of MoS 2 phase with particle size in the range 3.3-4.4 nm was confirmed by HRTEM. Catalytic activity was evaluated in the reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT) carried out in a flow reactor at 593 K and hydrogen pressure of 5.5 MPa. P-incorporation into the HMS-Ti material led to an overall increase in HDS activity and the hydrogenation ability of the sulfided catalysts. All catalysts proved to be stable during 10 h time-on-stream (TOS) operation. The activity of sulfide catalysts in the target reaction depends linearly on the surface exposure of Co species in the oxide precursors, as determined by XPS, and on the morphology of the sulfide form of catalysts (surface density of MoS 2 particles and their sizes) as determined by HRTEM.

  12. Thermophysical properties of undercooled liquid Co-Mo alloys

    NASA Astrophysics Data System (ADS)

    Han, X. J.; Wei, B.

    2003-05-01

    Using electromagnetic levitation in combination with the oscillating drop technique and drop calorimeter method, the surface tensions and specific heats of undercooled liquid Co-10 wt% Mo, Co-26.3 wt% Mo, and Co-37.6 wt% Mo alloys were measured. The containerless state during levitation produces substantial undercoolings up to 223 K (0.13TL), 213 K (0.13TL) and 110 K (0.07TL) respectively for these three alloys. In their respective undercooling ranges, the surface tensions were determined to be 1895 m 0.31(T m 1744), 1932 m 0.33(T m 1682), and 1989 m 0.34(T m 1607) mN mу. According to the Butler equation, the surface tensions of these three Co-Mo alloys were also calculated, and the results agree well with the experimental data. The specific heats of these three alloys are determined to be 41.85, 43.75 and 44.92 J molу Kу. Based on the determined surface tensions and specific heats, the changes in thermodynamics functions such as enthalpy, entropy and Gibbs free energy are predicted. Furthermore, the crystal nucleation, dendrite growth and Marangoni convection of undercooled Co-Mo alloys are investigated in the light of these measured thermophysical properties.

  13. 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

  14. Desulfurization of benzenethiol on Co?Mo(110) phases

    NASA Astrophysics Data System (ADS)

    Chen, D. A.; Friend, C. M.; Xu, H.

    1998-01-01

    The desulfurization of benzenethiol on Co-covered Mo(110) ( ?Co = 0.25-1.3 ML) produces benzene, H 2 and adsorbed carbon and sulfur. Benzene is formed via adsorbed phenyl thiolate, which is identified by X-ray photoelectron and electron energy loss spectroscopies. Benzene production is attributed to reaction on Co, since it is evolved at a temperature well below that required for sulfur-induced aggregation of Co. The reaction products and mechanisms are qualitatively similar on Co-covered Mo(110) and a range of other transition metal surfaces. The selectivity for benzene production on the 1.3 ML Co overlayer, ˜ 65%, is higher than on many surfaces. Furthermore, benzene evolution occurs at a very low temperature, 125 K, on the 1.3 ML Co film. Notably, we did not observe any new products or a dramatic change in reaction temperature or selectivity as a result of Co?Mo interactions or of structural changes in the Co layer. Comparison of the benzene evolution temperature for benzenethiol reaction with that of methane from methanethiol reaction on the close-packed Co overlays indicates that homolytic C?S bond scissions do not control the hydrogenolysis rate, in contrast to reaction on Mo(110) but similar to Ni(111). This difference may be due to hydrogen-induced structural transformations of the Co layer or to hydrogen-assisted C?S bond breaking.

  15. [Approaches to determine priorities and to analyze problems of health with a look from the equity: experience in the local level in Venezuela].

    PubMed

    Heredia, Henny; Artmann, Elizabeth; López, Nora; Useche, Julio

    2011-03-01

    This article analyzes the application of the explanatory moment of the Strategic Situational Planning (SSP) and the Analysis of the Situation of Health (ASIS), as approaches that together, allow to prioritize with a look from the equity problems of health in the local level feasible of intervention. By using the case study developed in the parish Zuata of Aragua State, Venezuela, it can be observed the application of both approaches The main actors of the above mentioned parish prioritized the low coverage of drinkable water, like a health problem. On having analyzed the problem, the following causes were selected to prepare the proposed action: scarce community participation, weakness of governmental plans, absence of political town-planning, inadequate administration of the public resources and lack of conscience in the rational use of water. At the end one concludes that the joint PES-ASIS allows to generate inputs that concretized for the actors in an action plan, they can contribute in the reduction of inequities. Also, the active participation of the actors allows to demonstrate the real problems of the population and to construct a plan of demands. PMID:21519677

  16. 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

  17. 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.

  18. [Abundance and richness of mollusks and crustaceans associated to the submerged roots of red mangrove (Rhizophora mangle) at Bocaripo Lagoon, Sucre, Venezuela].

    PubMed

    Cedeño, Jennellis; Jiménez Prieto, Mayré; Pereda, Luisana; Allen, Thays

    2010-10-01

    Mangrove roots are important habitats for many species. The abundance and richness of mollusks and crustaceans associated with the roots demerged of Rhizophora mangle was studied. The samples were gathered between February 2005 and January 2006, in Bocaripo lagoon, north coast of Sucre state, Venezuela. Five stations were established inside the lagoon; on every station two roots were chosen at random, put in plastic bags and scraped. The associated organisms were separated by taxa and fixed in 10% formaldehyde. One thousand ninety two specimens of mollusks, distributed in two classes: Bivalve and Gastropod were collected. Bivalve was the most abundant with 943 individuals. The most representative family was Mytilidae with 6 species, being Musculus lateralis the dominant species. The crustaceans were represented by 372 organisms, belonging to the class Malacostraca, where Panopeus herbstii (169 ind.) was the most abundant species. The families Panopeidae, Porcellanidae and Majidae had the highest number of species. Maximum abundance was in February (224 ind.), with a richness of 25 species and the minimums in November (45 ind.) and a richness of 12 species. The stations 1 and 5 presented the major abundance and richness of organisms, which could be related to environmental conditions favorable, as the major availability of microhabitats and nourishing offer; on the contrary the station 4, presented a more inhospitable environment, due to the high values in the salinity and temperature, which contributes with the minor abundance and richness of the present species. PMID:21302531

  19. 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.

  20. Burning, fire prevention and landscape productions among the Pemon, Gran Sabana, Venezuela: toward an intercultural approach to wildland fire management in Neotropical Savannas.

    PubMed

    Sletto, Bjørn; Rodriguez, Iokiñe

    2013-01-30

    Wildland fire management in savanna landscapes increasingly incorporates indigenous knowledge to pursue strategies of controlled, prescriptive burning to control fuel loads. However, such participatory approaches are fraught with challenges because of contrasting views on the role of fire and the practices of prescribed burning between indigenous and state fire managers. Also, indigenous and state systems of knowledge and meanings associated with fire are not monolithic but instead characterized by conflicts and inconsistencies, which require new, communicative strategies in order to develop successful, intercultural approaches to fire management. This paper is based on long-term research on indigenous Pemon social constructs, rules and regulations regarding fire use, and traditional system of prescribed burning in the Gran Sabana, Venezuela. The authors review factors that act as constraints against successful intercultural fire management in the Gran Sabana, including conflicting perspectives on fire use within state agencies and in indigenous communities, and propose strategies for research and communicative planning to guide future efforts for more participatory and effective fire management. PMID:23246908

  1. 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

  2. Last millennium sedimentation in the Gulf of Cariaco (NE Venezuela): Evidence for morphological changes of gulf entrance and possible relations with large earthquakes

    NASA Astrophysics Data System (ADS)

    Aguilar, Iliana; Beck, Christian; Audemard, Franck; Develle, Anne-Lise; Boussafir, Mohammed; Campos, Corina; Crouzet, Christian

    2016-01-01

    The Cariaco Basin and the Gulf of Cariaco in Venezuela are two major basins along the seismogenic El Pilar right lateral fault, among which the Cariaco Basin is a pull-apart. Both basins are sites of anoxia and organic-rich deposits. To examine whether the sediments in the Gulf of Cariaco have recorded traces of historical or prehistorical earthquakes, we extracted and analyzed twelve 1 m-long gravity cores, sampling the last millennium sedimentation. We focused on analyzing the sediment sources with different techniques (particle size analysis, XRF, loss on ignition tests, magnetic properties, Rock-Eval pyrolysis, 14C dating). The results confirm that major upwelling occurs at the western gulf entrance and makes deep water flowing from the Cariaco Basin into the Gulf of Cariaco. These flows carry an organic-rich suspended load. Furthermore, we found evidence of a particular, widespread fine-grained siliciclastic deposit (named SiCL3) within the gulf, whose age suggests that it likely formed during the large 1853 AD earthquake that stroke the Cumaná city. We suggest that the earthquake-induced large submarine landslides that modified the topography of the gulf's entrance, which in turn promoted upwelling and open marine water flows from the Cariaco Basin. The layer SiCL3 would be the sediment load remobilized during this chain of events.

  3. 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.

  4. 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.

  5. 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.

  6. Children live, feel, and respond to experiences of food insecurity that compromise their development and weight status in peri-urban Venezuela.

    PubMed

    Bernal, Jennifer; Frongillo, Edward A; Herrera, Héctor; Rivera, Juan

    2012-07-01

    Children's experiences of food insecurity (FI) may be conceptually distinct and different from those of adults. Previous study of children's experiences of FI has relied primarily on their parents' perspective. This study explored, described, and conceptualized experiences of FI in children attending 5 public schools in peri-urban areas of the Miranda State, Venezuela, South America using a naturalistic approach. Children aged 10-17 y were studied through focus groups (n = 42) and individual interviews (n = 13). Interviews were recorded, transcribed, and analyzed using grounded theory. Children were cognitively aware of FI, worry in their parents, and causes both external and internal to their households. Children were also emotionally aware of FI, with feelings of concern, anguish, and sadness, and manifestations such as crying. Children reported being physically hungry, experiencing reduced quantity and quality of food intake, having smaller meals, and recognizing thinness and fainting as consequences. Children's responses to FI included reduction of quality and quantity of food, child labor, sacrifice in food consumption, food from waste, support from extended family members, and strategies for purchasing, acquiring, preparing, and cooking food. Children were not always protected, especially when the head of the family was unemployed, had drug-alcohol problems, or was extremely poor. Protection could come from parents to children and from older children to parents and younger children. Children should have certain access to food that is dignified, timely, efficient, and adequate in harmonious social conditions to prevent and resolve situations that compromise their physical, cognitive, and socio-emotional well-being. PMID:22623397

  7. 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 β-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 β-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

  8. Horizonal and Vertical Spatial Patterns of Radon and Other Soil-gases Across the El Pilar Fault Trace at Guaraphiche, Edo. Surce (Venezuela)

    NASA Astrophysics Data System (ADS)

    LaBrecque, J. J.

    2002-05-01

    Soil-gases (radon, thoron, carbon dioxide and hydrogen) were measured at 63-cm depths along a transect perpendicular to the rupture (fault trace) from the 1997 Caricao earthquake (Mw=6.9) at Guarapiche, state of Sucre (Venezuela). The transect was about 40 meters long with ten sampling points with the spacings was smaller near the rupture. The shapes of the horizontal spatial patterns for radon (Rn-222), thoron (Rn-220) and total radon (Rn-222+Rn-220) were similar; the gas concentrations increased from both ends of the transect toward the rupture where a dip (valley) occurred. Both carbon dioxide and hydrogen gases showed anomalous values at the same sampling points. Twin peaks (anomalies) had been previously reported and suggested that they were due to blockage in the rupture. We have also determined soil-gases from 25-cm to 155-cm depths near the rupture and at the ends of the transect. The results showed that the soil-gas concentrations were not only higher in the upper levels (less than 65-cm) near the fault trace but were similar or greater than the lower levels. Thus, producing the twin peaks when soil-gas sampling was performed at the 65-cm depth. When the sampling was performed at only 45-cm depth the dip over the rupture was much less and the patterns looked more like a broad doublet peak. In conclusion, one can clearly see that not only positive soil-gas anomalies can occur over a fault trace but also negative ones too. 1) This work was partially funded by a research contract from the Venezuelan National Science Foundation (CONICIT Proyecto S1-95000448). 2) Mailing Address: Centro de Quimica, 8424 NW 56th Street, Suite 00204,Miami, Fl 33166 (USA). E-mail jjlabrec@ivic.ve FAX: +58-212-504-1214

  9. 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

  10. The Structural Basis for Substrate Anchoring, Active Site Selectivity, and Product Formation by P450 PikC from Streptomyces venezuelae

    PubMed Central

    Sherman, David H.; Li, Shengying; Yermalitskaya, Liudmila V.; Kim, Youngchang; Smith, Jarrod A.; Waterman, Michael R.; Podust, Larissa M.

    2010-01-01

    The pikromycin (Pik)/methymycin biosynthetic pathway of Streptomyces venezuelae represents a valuable system for dissecting the fundamental mechanisms of modular polyketide biosynthesis, aminodeoxysugar assembly, glycosyltransfer, and hydroxylation leading to the production of a series of macrolide antibiotics, including the natural ketolides narbomycin and pikromycin. In this study, we describe four x-ray crystal structures and allied functional studies for PikC, the remarkable P450 monooxygenase responsible for production of a number of related macrolide products from the Pik pathway. The results provide important new insights into the structural basis for the C10/C12, and C12/C14 hydroxylation patterns for the 12- (YC-17) and 14-membered ring (narbomycin) macrolides, respectively. This includes two different ligand-free structures in an asymmetric unit (resolution 2.1 Å) and two co-crystal structures with bound endogenous substrates YC-17 (resolution 2.35 Å) or narbomycin (resolution 1.7 Å). A central feature of the enzyme-substrate interaction involves anchoring of the desosamine residue in two alternative binding pockets based on a series of distinct amino acid residues that form a salt bridge and a hydrogen bonding network with the deoxysugar C3? dimethylamino group. Functional significance of the salt bridge was corroborated by site-directed mutagenesis that revealed a key role for E94 in YC-17 binding, and E85 for narbomycin binding. Taken together, the x-ray structure analysis, site-directed mutagenesis and corresponding product distribution studies reveal that PikC substrate tolerance, and product diversity result from a combination of alternative anchoring modes, rather than an induced fit mechanism. PMID:16825192

  11. Three-Dimensional Structure of DesVI from Streptomyces venezuelae: A Sugar N,N-Dimethyltransferase Required for dTDP-Desosamine Biosynthesis

    SciTech Connect

    Burgie, E. Sethe; Holden, Hazel M.

    2008-07-28

    d-Desosamine, or 3-(dimethylamino)-3,4,6-trideoxyglucose, is an unusual sugar found on the macrolide antibiotic erythromycin, and it has been shown to play a critical role in the biological activity of the drug. Desosamine is added to the parent aglycone via the action of a glycosyltransferase that utilizes dTDP-desosamine as its substrate. Six enzymes are required for the biosynthesis of dTDP-desosamine in Streptomyces venezuelae, with the last step catalyzed by DesVI, an N,N-dimethyltransferase. Here we describe the X-ray crystal structure determined to 2.0 {angstrom} resolution of DesVI complexed with S-adenosylmethionine (SAM) and the substrate analogue UDP-benzene. Each subunit of the DesVI dimer contains a seven-stranded mixed {beta}-sheet flanked on either side by {alpha}-helices. In addition to this major tertiary structural element, there is a four-stranded antiparallel {beta}-sheet that provides the platform necessary for subunit-subunit assembly. On the basis of the UDP-benzene binding mode, the DesVI substrate, dTDP-3-(methylamino)-3,4,6-trideoxyglucose, has been modeled into the active site. This model places the C-6' methyl group of the sugar into a hydrophobic patch that is well-conserved among putative nucleotide-linked sugar dimethyltransferases. It is formed by Trp 140, Met 178, and Ile 200. The sugar C-2' hydroxyl sits near Tyr 14, and its C-3' amino group is properly positioned for direct in-line attack of the cofactor's reactive methyl group. While methyltransferases that catalyze single alkylations at carbons, oxygens, sulfurs, and nitrogens have been well characterized, little is known regarding enzymes capable of N,N-dimethylation reactions. As such, the ternary structure of DesVI reported here serves as a structural paradigm for a new family of dimethyltransferases that function on nucleotide-linked sugars.

  12. Oral transmission of Chagas disease: typing of Trypanosoma cruzi from five outbreaks occurred in Venezuela shows multiclonal and common infections in patients, vectors and reservoirs.

    PubMed

    Muñoz-Calderón, A; Díaz-Bello, Z; Valladares, B; Noya, O; López, M C; Alarcón de Noya, B; Thomas, M C

    2013-07-01

    In Venezuela six episodes of oral transmission of Chagas disease (OChD) have been described, being the one reported in 2007 with a total of 103 people infected the largest worldwide. This work shows the use of three molecular markers (mini-exon gene and domains 24S? and 18S of the ribosomal RNA) to characterize the infecting Trypanosoma cruzi strain of patients, reservoirs and vectors involved in five of the six OChD outbreaks. For this, 28 T. cruzi isolates were characterized by PCR, and the products of these reactions cloned and sequenced to reveal the existence of different TcI SL-IR genotypes. We also describe a new PCR assay able to discriminate between TcIb and TcId parasite populations. In summary, we have identified mostly parasites with the TcId haplotype and multiclonal populations with predominance of haplotype TcId (65.2%). Additionally, populations of haplotypes TcIb, TcIa and mixtures (TcId+TcIb, TcId+TcIa, TcIb+TcIa) are recurrent in samples obtained from children. The analysis of the SL-IR motif showed two clones depicting a different motif that could be an evidence for a possible hybrid haplotype between TcIa and TcIb (haplotype TcIa/Ib). Interestingly, in a single patient haplotype differences between T.cruzi isolates obtained pre and post-treatment were found. In conclusion, our findings show that in order to understand the pathogenic mechanisms involved in the orally acquired Chagas disease there is a need to join efforts to study T. cruzi haplotypes, their tissue tropisms and their susceptibility to chemoteraphy. PMID:23567816

  13. 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.

  14. [Present state of diseases and other signs of reef deterioration at seven coral reefs at Los Roques Archipelago National Park, Venezuela].

    PubMed

    García, Adriana; Cróquer, Aldo; Pauls, Sheila M

    2003-06-01

    This work was aimed to determine the incidence of coral diseases in six different reef sites at the Parque Nacional Archipiélago de Los Roques, Venezuela: Arrecife de herradura, Arrecife costanero, both at Dos Mosquises Sur Key, Boca de Cote, Carenero, Crasquí and Pelona de Rabusquí. Each reef was surveyed by using ten 10 m2-band transects (10 x 1 m), placed parallel to the long axis of the reef within a depth gradient ranging from 1 to 9 m depth. All healthy and injured corals, along each band transect, were counted and identified to species level. Additionally, all diseases and recent mortality that were still identifiable on each colony were also recorded. The occurrence of diseased colonies and other signs of reef decline between localities were compared by means of a Chi2 test. The absolute, relative and mean incidence was estimated for each disease and other signs of damage observed for all coral species surveyed at each site. The overall incidence of coral diseases was low for all the localities surveyed, only 6.04% of the 3 344 colonies observed, showed signs of diseases. The most important diseases recorded were the Yellow-Blotch Disease (YBD) and Dark Spots Disease (DSD) with 2.1% +/- 1.52 y 2.1% +/- 2.54, respectively. Significant differences were found in the incidence of coral diseases between reef sites (Chi2 p < 0.05). Finally, the occurrence of colonies injured by parrotfish bites and pomacentrids was higher compared with the incidence of coral diseases for all the reefs surveyed. In conclusion, currently the proportion of healthy colonies at Los Roques coral reefs is higher than the percentage of both diseased and injured colonies. PMID:15264569

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. [Growth and survival of the green mussel P. viridis (Bivalvia: Mytilidae) in bottom culture conditions in Turpialito, Golfo de Cariaco, Venezuela].

    PubMed

    Acosta, Vanessa; Montes, Marbelis; Cortez, Roraysi; Guevara, Miguel; Lodeiros, César

    2012-12-01

    Mussels represent one of the most important mollusk species for culture activities around the world, and their growth may depend on the culture system used and locality. In this study, we evaluated the growth of Perna viridis in bottom culture to test its performance when using natural food, and to decide its use as a culture species in the Gulf of Cariaco. For this, mussel seeds (35.81 +/- 1.41 mm in length) were obtained in the locality of Guaca (North coast of Sucre state) and transferred to the Hydrobiological Station of Turpialito, Gulf of Cariaco, Sucre state, Venezuela, where they were planted in "Spanish baskets" to evaluate their growth between July 2007 and February 2008. Monthly survival was determined and the maximum shell length, dry mass of muscle and remains tissues of the gonad. The environmental parameters (water temperature, salinity, dissolved oxygen, chlorophyll a, total seston and organic fraction), in the cultivation area were determined every 15 days. Monthly measurements were made of proteins, lipids and carbohydrates to seston. During the entire study the mussels showed continued growth, ultimately reaching a maximum length of 78.7 +/- 4.43 mm. However, the growth rate of the dry mass of somatic (muscle, other tissue) and reproductive tissues showed variability throughout the study, and observed a significant increase by the end of the experiment. The observed variations in the growth rate of the reproductive tissue mass depended on the reserves accumulated and food offered by the environment. The organic seston throughout the experience showed an independence of temperature and chlorophyll a values; this one maintained values above 1 mg/L, thus forming the main food resource for mussels. The high content of proteins, lipids and carbohydrates observed in the seston at the end of the study, might be mainly associated with coastal upwelling, which provides a great food contribution of phytoplankton and organic type. The high survival rate (>80%), increase in the length of the shell and the high gonad production, suggests an excellent physiological condition of P. viridis, related to the availability and quality of food particularly the organic type present in the medium. We concluded that the bottom culture can provide an alternative aquaculture production in the Gulf of Cariaco. PMID:23342526

  1. Snake venomics and antivenomics of Bothrops colombiensis, a medically important pitviper of the Bothrops atrox-asper complex endemic to Venezuela: Contributing to its taxonomy and snakebite management.

    PubMed

    Calvete, Juan J; Borges, Adolfo; Segura, Alvaro; Flores-Díaz, Marietta; Alape-Girón, Alberto; Gutiérrez, José María; Diez, Nardy; De Sousa, Leonardo; Kiriakos, Demetrio; Sánchez, Eladio; Faks, José G; Escolano, José; Sanz, Libia

    2009-03-01

    The taxonomic status of the medically important pitviper of the Bothrops atrox-asper complex endemic to Venezuela, which has been classified as Bothrops colombiensis, remains incertae cedis. To help resolving this question, the venom proteome of B. colombiensis was characterized by reverse-phase HPLC fractionation followed by analysis of each chromatographic fraction by SDS-PAGE, N-terminal sequencing, MALDI-TOF mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of tryptic peptides. The venom contained proteins belonging to 8 types of families. PI Zn(2+)-metalloproteinases and K49 PLA(2) molecules comprise over 65% of the venom proteins. Other venom protein families comprised PIII Zn(2+)-metalloproteinases (11.3%), D49 PLA(2)s (10.2%), l-amino acid oxidase (5.7%), the medium-sized disintegrin colombistatin (5.6%), serine proteinases (1%), bradykinin-potentiating peptides (0.8%), a DC-fragment (0.5%), and a CRISP protein (0.1%). A comparison of the venom proteomes of B. colombiensis and B. atrox did not support the suggested synonymy between these two species. The closest homologues to B. colombiensis venom proteins appeared to be toxins from B. asper. A rough estimation of the similarity between the venoms of B. colombiensis and B. asper indicated that these species share approximately 65-70% of their venom proteomes. The close kinship of B. colombiensis and B. asper points at the ancestor of B. colombiensis as the founding Central American B. asper ancestor. This finding may be relevant for reconstructing the natural history and cladogenesis of Bothrops. Further, the virtually indistinguishable immunological crossreactivity of a Venezuelan ABC antiserum (raised against a mixture of B. colombiensis and Crotalus durissus cumanensis venoms) and the Costa Rican ICP polyvalent antivenom (generated against a mixture of B. asper, Crotalus simus, and Lachesis stenophrys venoms) towards the venoms of B. colombiensis and B. asper, supports this view and suggests the possibility of indistinctly using these antivenoms for the management of snakebites by any of these Bothrops species. However, our analyses also evidenced the limited recognition capability or avidity of these antivenoms towards a number of B. colombiensis and B. asper venom components, most notably medium-size disintegrins, bradykinin-potentiating peptides, PLA(2) proteins, and PI Zn(2+)-metalloproteinases. PMID:19457355

  2. 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

  3. 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

  4. 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

  5. Tectonic and thermal history of the western Serrania del Interior foreland fold and thrust belt and Guarico Basin, north central Venezuela: Implications of new apatite fission track analysis and seismic interpretation

    NASA Astrophysics Data System (ADS)

    Perez de Armas, Jaime Gonzalo

    Structural analysis, interpretation of seismic reflection lines, and apatite fission-track analysis in the Western Serrania del Interior fold and thrust belt and in the Guarico basin of north-central Venezuela indicate that the area underwent Mesozoic and Tertiary-to-Recent deformation. Mesozoic deformation, related to the breakup of Pangea, resulted in the formation of the Espino graben in the southernmost portion of the Guarico basin and in the formation of the Proto-Caribbean lithosphere between the diverging North and South American plates. The northern margin of Venezuela became a northward facing passive margin. Minor normal faults formed in the Guarico basin. The most intense deformation took place in the Neogene when the Leeward Antilles volcanic island arc collided obliquely with South America. The inception of the basal foredeep unconformity in the Late Eocene-Early Oligocene marks the formation of a perisutural basin on top of a buried graben system. It is coeval with minor extension and possible reactivation of Cretaceous normal faults in the Guarico basin. It marks the deepening of the foredeep. Cooling ages derived from apatite fission-tracks suggest that the obduction of the fold and thrust belt in the study area occurred in the Late Oligocene through the Middle Miocene. Field data and seismic interpretations suggest also that contractional deformation began during the Neogene, and specifically during the Miocene. The most surprising results of the detrital apatite fission-track study are the ages acquired in the sedimentary rocks of the easternmost part of the study area in the foreland fold and thrust belt. They indicate an Eocene thermal event. This event may be related to the Eocene NW-SE convergence of the North and South American plates that must have caused the Proto-Caribbean lithosphere to be shortened. This event is not related to the collision of the arc with South America, as the arc was far to the west during the Eocene.

  6. 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)

  7. Cúmulos globulares como trazadores de bimodalidad estelar en galaxias cD

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se muestra que tanto la forma de los perfiles de brillo como de color observados en dos galaxias arquetípicas de tipo cD (NGC 1399 y NGC 4486) son compatibles con la presencia de poblaciones estelares bi-modales que comparten la misma distribución espacial y composición química de las familias dominantes de cúmulos globulares asociadas con ellas. El modelo resultante también predice una variación de la frecuencia específica de los cúmulos como función del radio galactocéntrico. Se discute este resultado en el contexto de una variedad de escenarios astrofísicos que intentan describir la formación de galaxias cD.

  8. Interface observation of heat-treated Co/Mo2C multilayers

    NASA Astrophysics Data System (ADS)

    Yuan, Yanyan; Le Guen, Karine; André, Jean-Michel; Mény, Christian; Ulhaq, Corinne; Galtayries, Anouk; Zhu, Jingtao; Wang, Zhanshan; Jonnard, Philippe

    2015-03-01

    We study the interface evolution of a series of periodic Co/Mo2C multilayers as a function of the annealing temperature up to 600 °C. Different complementary techniques are implemented to get information on the phenomenon taking place at the interfaces of the stack. The periodical structure of Co/Mo2C multilayer is proven by time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiles which demonstrate the formation of an oxide layer at both air/stack and stack/substrate interfaces. From Nuclear magnetic resonance (NMR) spectra, we observed the intermixing phenomenon of Co and C atoms for the as-deposited sample, and then at annealing temperature above 300 °C Co and C atoms separate from their mixed regions. Comparison of NMR results between Co/Mo2C and Co/C references confirms this phenomenon. This is in agreement with X-ray emission spectroscopy (XES) measurements. Furthermore the calculation of the Co-C, Co-Mo and Mo-C mixing enthalpy using Miedema's model gives a proof of the demixing of Co and C atoms present within the stacks above 300 °C. From the transmission electron microscopy (TEM) analysis, we found the presence of some crystallites within the as-deposited sample as well as the mainly amorphous nature of all layers. This is confirmed using X-ray diffraction (XRD) patterns which also demonstrate the growth of crystallites induced upon annealing.

  9. 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.

  10. 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.

  11. 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%.

  12. Telescópio de pequeno porte como suporte ao ensino em cidades com intensa poluição luminosa II

    NASA Astrophysics Data System (ADS)

    Pereira, P. C. R.; Santos-Júnior, J. M.; Cruz, W. S.

    2003-08-01

    Para a maioria dos estudantes, sua passagem pelo ensino formal fundamental envolve a transmissão de fatos que devem ser guardados para um exame, a habilidade para lembrar fórmulas e, eventualmente, a repetição de experimentos que devem produzir resultados exigidos pelo professor. O resultado deste modelo de ensino, ao longo dos anos, é conhecido por todos: desconhecimento e descontentamento, por parte dos estudantes, de temas relativos ao papel e aos processos da ciência. Acreditamos que a Astronomia, pelo seu caráter observacional, é uma das áreas do conhecimento que pode contribuir neste cenário. A Fundação Planetário da Cidade do Rio de Janeiro possui um telescópio Meade LX-200 (25cm) que, juntamente com as câmeras CCD ST-7E e ST8E, tem sido utilizado em projetos voltados aos estudantes do ensino médio desde o ano 2000. Tais projetos envolvem a condução de um projeto de pesquisa observacional num nível apropriado, e possibilitam o contato com técnicas e novas tecnologias: computador, software para manipulação de dados e gráficos, programas de tratamento e redução de dados, uso de equipamentos óptico-eletrônicos (telescópio e CCD), bem como o processo de aquisição de conhecimento. Dentro da proposta dos anos anteriores, priorizamos projetos de uma noite, ou seja, procuramos trabalhar com fenômenos que apresentem variabilidade com intervalo de recorrência relativamente curto. Em todos os casos, optamos pela fotometria diferencial, que tem se mostrado bastante eficiente para o céu luminoso como o da cidade do Rio de Janeiro. Neste painel, apresentamos alguns dos projetos desenvolvidos no último ano, com 25 estudantes. Apresentamos os resultados da observação da variável pulsante AI Vel (V = 6,6) e da variável cataclísmica FO Aqr (V = 13,5), e do monitoramento do trânsito da lua de Júpiter, Europa, ocorrido em 30 de abril de 2003. As curvas de luz produzidas para as primeiras estão concordantes com as da literatura, assim como os respectivos períodos encontrados (1h20min e 4h48min). No caso do FO Aqr, ficou evidente, também, a modulação decorrente da rotação da anã branca receptora (21min). O erro estimado é de 0,01 magnitude. Propomos uma maior utilização de telescópios de pequeno porte, como suporte ao ensino (médio e superior) em cidades com poluição luminosa. Escolas e Planetários seriam ambientes propícios para a localização do telescópio. Os critérios adotados na escolha dos objetos e o método observacional empregado são também apresentados.

  13. A Utilização da Astronomia como Tema Interdisciplinar e Aplicações de Objetos de Aprendizagem

    NASA Astrophysics Data System (ADS)

    da Silva, L. A.; Voelzke, M. R.

    2008-09-01

    Este trabalho visa analisar a possibilidade de relacionar conteúdos aplicados no ensino fundamental e médio de forma interdisciplinar por intermédio da astronomia, com a intervenção de objetos de aprendizagem que possam integrar as disciplinas e a utilização de recursos tecnológicos. Em uma pesquisa prévia com 20 professores de uma escola estadual situada na cidade de Guarulhos foi observado que apenas 25% dos professores utilizam algum recurso tecnológico para o desenvolvimento de conteúdos pertinentes à sua disciplina, tais como sites e softwares educativos, sendo que a maioria absoluta continua ensinando apenas com livros didáticos. A maior parte dos professores apresenta dificuldades em trabalhar sua disciplina de forma interdisciplinar, ou seja, 75% dos professores preferem aplicar os conteúdos seguindo uma hierarquia linear de tópicos, evitando a discussão de temas que de alguma forma estão relacionados. A astronomia pode vir à fascinar o ser humano e despertar sua curiosidade promovendo um maior interesse no aprendizado, podendo favorecer análises interdisciplinares de forma lógica e objetiva, desta forma colocar a astronomia como tema motivador interdisciplinar, pode ser relevante no que se refere ao distanciamento da fragmentação dos conteúdos. No Estado de São Paulo, a implantação da proposta curricular no ensino fundamental e médio mostra claramente a inserção da astronomia na maior parte das séries, principalmente na 6ª série em que todo o bimestre se fala de astronomia.

  14. 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

  15. 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.

  16. 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

  17. Cryptococcus neoformans, Cryptococcus gattii: serotypes in Venezuela.

    PubMed

    Pérez, C; Dolande, M; Moya, M; Roselló, A; de Capriles, Claudia R Hartung; Landaeta, M E; Mata-Essayag, S

    2008-09-01

    Cryptococcus neoformans is one of the medically important yeast-like fungi. C. neoformans var. gatti has been made a species: C. gatti. In our country, there are few studies about these two species and their serotypes. The aim of this study was to determine the distribution of C. neoformans and C. gattii, and their serotypes in Venezuelan clinical isolates. One hundred and twenty C. neoformans and 12 C. gattii clinical isolates were identified by L-canavanine, glycine, and bromothymol blue agar media (CGB). These were investigated by agglutination and adsorption studies with anticryptococcal sera, which were produced by rabbit immunization. Of the 132 isolates 59.8% were typed serotype A (C. neoformans), followed by 25.8% serotype D (C. neoformans), 5.3% serotype AD (C. neoformans), and 5.3% were typed serotype C (var. gattii). Additionally 3.8% were serotype B (C. gattii). PMID:18512129

  18. Education in Venezuela. Bulletin, 1948, No. 14

    ERIC Educational Resources Information Center

    Goetz, Delia

    1948-01-01

    The Office of Education has undertaken the preparation of a series of basic studies on education in a number of Central and South American countries under the sponsorship of the Interdepartmental Committee on Cultural and Scientific Cooperation. This series of studies is part of a program to promote understanding of educational conditions in the…

  19. 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)

  20. 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

  1. 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).

  2. 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…

  3. 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

  4. 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 ...

  5. 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

  6. [Occupational exposure to lead in production units in Maracaibo, Venezuela].

    PubMed

    Corzo, G; Naveda, R

    1998-09-01

    A medical occupational study was performed in 40 workers belonging to productive units in telecommunication works, 22 to car radiator mechanics and 11 to battery repairs. A practical medical and occupational study was applied to the group and also were determined their blood lead and air lead exposure levels. Seventy-three individuals, without risk of laboral exposure to lead, without familiar, pathological and occupational antecedents, and healthy at the time of the test, to whom the blood lead levels were determined served as control group. The mean values of plumbemia in exposure workers to inorganic lead exceed the level threshold of the COVENIN 2277-85 norm (30 micrograms/dl) (Telecommunication work, 40.10 micrograms/dl, radiators mechanics, 37.40 micrograms/dl and battery repairs, 45.77 micrograms/dl), values that were significantly higher (p < 0.0001) compared with the ones obtained in the non-exposed population. The factors that can influence the variability of the results were analyzed and it was established a correlation between the plumbemia of the radiator mechanics and battery repairmen and the length of occupational period and air lead levels (p < 0.0001). The inherent factors to the climatic, occupational and personal conditions of technicians in telecommunications, are presented as elements able to explain the lack of correlation between blood lead levels and length of occupational period and air lead. The clinical findings in exposed workers were unspecific. The workers do not practice or follow the basic sanitary regulations, personal protection and industrial security. This work will contribute to establish a basic description, to further and more complex observational prospective studies in order to determine the occurrence of alterations that are derived from occupational lead exposure. PMID:9780551

  7. [Primary amebic meningoencephalitis: two new cases report from Venezuela].

    PubMed

    Petit, Fátima; Vilchez, Varinka; Torres, Gustavo; Molina, Omaira; Dorfman, Saúl; Mora, Eduardo; Cardozo, José

    2006-12-01

    Primary amebic menigoencephalitis (PAM) is rare. Two cases of PAM in Venezuelan patients are described. Case 1, a 10 year-old male with headache, fever, vomiting. The patient swam in a water reservoir before the onset of his disease. He died during his third hospital day. Case 2, a 23 year-old male with a history of headache, fever, vomiting, drowsiness, and behavioral disturbances. The patient died on his second hospital day. The diagnosis in both cases was PAM due to Naegleria fowleri. Central nervous system infection by free-living amebas should be considered in meningoencephalitides with bacterial-free cerebro-spinal fluid. PMID:17221024

  8. 78 FR 55096 - Ferrosilicon from Russia and Venezuela

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... reasonable indication that an industry in the United States is materially injured by reason of imports from... International Union (``USW''); and the International Union, United Automobile, Aerospace and Agricultural Implement Workers of America (``UAW''), alleging that an industry in the United States is materially...

  9. 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…

  10. 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.

  11. 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…

  12. 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…

  13. 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.

  14. 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.

  15. 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.

  16. 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…

  17. 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.

  18. 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.

  19. 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

  20. 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.