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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. 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.

  3. 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

  4. [Yellow fever in Venezuela].

    PubMed

    Valero, Nereida

    2003-12-01

    In Venezuela the yellow fever has been presented in three wild focuses: San Camilo in the Tachira State, South of the Lake in the Zulia and Guayana. The last human case registered of urban yellow fever happened in 1918 in the city of Coro, Falcon State. Nevertheless, according to the epidemic registration of the Ministry of Health and Social Development corresponding to the epidemiological week no. 38 of the year 2003, 318 cases of wild yellow fever had been investigated (173 of the Zulia and 145 of Tachira), of which were confirmed 31, with a mortality of 58.0%. Previous to the appearance of this outbreak, it was notified an epizooty in monkeys with high mortality in November of 2002 in the Jesus Maria Semprum municipality of the Zulia State, persisting until September of 2003, extended to the Tachira State. Possible reasons of the reemergency of this illness are analyzed based on the high mobilization of displaced population, remote areas and of difficult access, high concentration of indigenous population (Bari, Yuepa, Wayúu) and border conflict. PMID:14727380

  5. English Teaching Profile (Provisional): Venezuela.

    ERIC Educational Resources Information Center

    British Council, London (England). English Language and Literature Div.

    This profile of the English language teaching situation in Venezuela discusses the status of English in society and in the educational system. It also gives an account of Venezuelan political, economic, and social life. A description is given of the education system and reforms that have been proposed for nursery school through higher education.…

  6. Media and Consumerism in Venezuela.

    ERIC Educational Resources Information Center

    Martin, Richard; And Others

    1979-01-01

    Outlines opposing theories of the role of the commercial mass media in national economic development; reports on a survey of the attitudes of 636 adult residents of Barquisimeto, Venezuela, with respect to consumption, advertising, and national development, and shows how the results relate to the theory proposed by Daniel Lerner. (GT)

  7. 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,…

  8. 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.

  9. Republic of Venezuela. Country profile.

    PubMed

    Hakkert, R

    1985-06-01

    Venezuela's current economic and demographic situation is described. Venezuela is a major oil country, and the oil industry accounts for 90% of the country's foreign exchange, 70% of the government's revenues, and 15% of the gross domestic product. The economy experienced a sudden and high rate of economic growth in the mid-1970s as a result of high oil prices; however, in recent years, declining oil prices have had a negative effect on the economy. The country is now faced with a serious trade deficit, and the government recently imposed restrictions on imports. Imports in recently years had increased markedly. The emphasis on the oil industry weakened the agricultural sector and, as a result, food imports increased. In addition, the rapid economic growth experienced during the 1970s greatly increased the demand for imported consumer goods. Venezuela has the 4th highest foreign debt in the world (US$35 billion). Despite these problems Venezuela has a relatively high per capita income (US$4,140) and living standard, compared to other countries in the region. Venezuela's total population is 14.6 million, and the population is unevenly distributed. 86% of the population lives in cities of 2500 or more. 37.4% of the population and 70% of the industry is concentrated in the Federal District which contains Caracas, and in the surrounding states of Aragua, Miranda, and Carabobo. This area constitutes only 2.36% of the country's territory. Most of the oil fields are located in the state of Zulia which also contains the country's 2nd largest city (Maracaibo). The country's coastal area contains most of the agricultural lands, and the prairies just south of the coastal mountain ranges are devoted primarily to cattle raising. The remaining 58.2% of the country's territory is essentially jungle and contains only 6.9% of the country's population. The annual population growth rate is 3.11%. Although the rate declined in recent years it is higher than in most of the other countries in the region. In 1981, 1 million of the countrys, residents were foreign born. The oil industry attracted many immigrants, and illegal immigration is a serious problem. 41% of the population is under 15 years of age, the birth rate is 33-37, the death rate is 5, the infant mortality rate is 39, and life expectancy is 69 years. Average household size is 5.28. Family life is highly unstable. 32% of the couples are in informal unions, and these couples account for 52% of all births. 20% of the households are headed by low income women. The total fertility rate was 6.7 in 1961 and is currently 4.3. There are 3.2 million housing units, and 800,000 of these are classified as inadequate. 65% of the population is mestizo, 20% is European, and the remaining 15% are from various other countries or members of indigenous groups. The population is predominantly Catholic. The literacy rate is 83%; however, 71% of the males and 84% of the females in rural areas are illiterate. 31.5% of the population is in the labor force, and 27.5% of the labor force is female. 20% of the labor force is in the service sector and many of these work in the overgrown government bureaucracy. Only 15% of the labor force is engaged in the primary sector. 37% of the residents of Caracas and 80% of the country's rural residents live below the poverty level. PMID:12313690

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

    USGS Publications Warehouse

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

    2006-01-01

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

  11. Mastery: A Lesson from Maria in Venezuela

    ERIC Educational Resources Information Center

    Powell, Sandra Anez; Powell, Norman W.

    2012-01-01

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

  12. 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.

  13. Implementing Pre-Vocational Studies in Venezuela.

    ERIC Educational Resources Information Center

    Kim, Young Mi

    This paper describes prevocational education in Venezuela on each educational level. First, it sets a historical context by identifying aspects of technical education that emerged at different times in its development; then it identifies certain strategies created to support the implementation of prevocationalization, and finally it concludes by…

  14. The Development of Education in Venezuela.

    ERIC Educational Resources Information Center

    Sanchez, George I.

    The present study aims to bring to the reader an understanding of Venezuela's educational patterns, needs, and development within the framework of the country's economic and social situation. Much of this report is devoted to historical backgrounds --to cultural development, politics, immigration, economics, and international attitudes-- to give…

  15. Heavy and extra heavy hydrocarbons in Venezuela

    SciTech Connect

    Zamora, L.G.; Gallango, O.E. )

    1993-02-01

    Most of Venezuela's giant accumulations of heavier thatn 22[degrees] API hydrocarbons, are located in the more stable flanks of the Maracaibo and Eastern Venezuela basins, at depths shallower than 2400 meters. The reservoir rocks are unconsolidated fluviodeltaic Neogene sands, transgressive over large regional Oligocene unconformities. There are also large volumes accumulated along the mountainous and more active flanks, either in Neogene alluvial sediments or in Cretaceous and older fractured rocks. These accumulations, located near present day erosion surfaces, are subjected to meteoric water influx. Extensive research carried out by the affiliates of Petroleos de Venezuela, S.A., and other institutions during the past ten years, has shown tha the main cause of degradation is the action of microorganisms brought in by meteoric water influx and, to less extent, the washing of lighter hydrocarbon fractions by either connate or meteric water. These studies have also shown that most of the heavy and extra-heavy hydrocarbons are the result of biodegradation of low maturity crudes generated from Cretaceous rocks, rich in marine organic matter, which started its generation during the Paleogene. The heavy and extra-heavy hydrocarbons, bitumen included, so far discovered in Venezuela, add up to 1.5 [times] 10[sup 12] bbl in place. This figure includes proved, probable and possible volumes, and the expectancy of additional hydrocarbons of this kind to be discovered yet is of 0.1 [times] 10[sup 12] bbl in place.

  16. 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

  17. 78 FR 55096 - Ferrosilicon from Russia and Venezuela

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

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

  18. 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…

  19. 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)

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

    ERIC Educational Resources Information Center

    Nieto, Ruben D.; Henderson, Janet L.

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

  1. 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,…

  2. Trypanosoma evansi in capybara from Venezuela.

    PubMed

    Arias, J F; García, F; Rivera, M; López, R

    1997-04-01

    During the slaughtering season of February and March 1991, 559 capybaras (Hydrochoerus hydrochaeris) were tested for Trypanosoma evansi in two areas in Venezuela: El Frio Ranch and El Cedral Ranch. Blood and serum samples were evaluated for T. evansi. Forty-eight (9%) of 559 capybaras had T. evansi using the microcentrifugation technique. Further, 279 (50%) of the 559 capybaras had antibodies against T. evansi immunofluorescence test in both ranches. Thus, capybaras may be important in the epizootiology of T. evansi in this enzootic area. PMID:9131577

  3. [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

  4. Occurrence of methylmercury in Lake Valencia, Venezuela

    SciTech Connect

    Jaffe, R.; Cai, Y.; West-Thomas, J.

    1997-12-31

    The presence of mercury in the environment has received renewed attention during recent years. This is in part due to the known human health and ecological effects of the highly toxic organomercury compounds, and to the fact that novel and improved analytical techniques such as atomic fluorescence spectroscopy (AFS) and capillary chromatography with AFS detection, have enhanced significantly the detection of trace amounts of mercury and organo mercurials in environmental samples. Such techniques have allowed for a better understanding of the biogeochemical cycle of mercury in the aquatic environment. This paper reports on the presence of methylmercury in the water column and sediments of a hyper-eutrophic lake. Lake Valencia is a freshwater lake located in North-Central Venezuela`s Aragua Valley. The lake`s surface area covers approximately 350 km{sup 2}, with a mean depth of 19 m and a maximum depth of 41 m. Due to the discharge of waste waters from the cities of Maracay and Valencia, as well as from other smaller villages and agricultural areas in its watershed, Lake Valencia has become hyper-eutrophic. The population of phytoplankton, particularly of blue-green algae, has increased dramatically during the last two decades resulting in anoxic conditions in the lower part of the water column during most of the year. In addition, concentrations of anthropogenic chemicals, including heavy metals, have increased in the Lake during the last four decades. 15 refs., 2 figs.

  5. 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

  6. [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

  7. 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

  8. 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

  9. 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.

  10. 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)

  11. 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…

  12. 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.

  13. [Increasing difficulties for scientific publication in Venezuela].

    PubMed

    Ryder, Elena

    2014-03-01

    A very important increase in the costs of the edition of scientific journals has taken place in Venezuela, due to difficulties in obtaining imported free acid paper and other materials used for handling documents. Like other journals, Investigaci6n Clinica has been considering switching completely to a digital publication format; however there are several reasons that prevent us to doing it at this time: the journal is distributed in printed form to many national institutions, which do not have immediate access to digital information. In addition, there exists a commitment of shipment of printed issues for some international indices and in exchange with other national and foreign journals, whose printed format we receive. Another important aspect is that our University maintains a weak technological platform that makes difficult the immediacy required for the interchange with authors and consulted referees of received papers; and there is a latent danger of limitations in the use of digital technologies, due to current national politic problems. Consequently, we need to continue with the printed format, but must reduce the amount of printed issues, so as not to limit the number of papers published in each edition. Nevertheless, there is an ever increasing number of contributions from foreign researches and Investigaci6n Clinica has been recently included in two new international indices, the SEIIC from Argentina and the Infobase Index from India, reasons that obligate us to maintain our levels of excellence and commitment to our authors and readers. PMID:24758096

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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).

  1. 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

  2. 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

  3. 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…

  4. 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.

  5. [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

  6. 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

  7. Education and the Labor Market in Venezuela, 1975-1984.

    ERIC Educational Resources Information Center

    Psacharopoulos, George; Steier, Francis

    1988-01-01

    Examines various education-related aspects of Venezuela's labor market for 1975-1984, using a sample of 40,000 workers. Education returns have declined only two percent during a rapid educational expansion period. The increased supply of educated persons influenced the narrowing of earnings differentials and led to more equitable income…

  8. Diversity of avian haemosporidians in arid zones of northern Venezuela.

    PubMed

    Belo, Nayara O; Rodríguez-Ferraro, Adriana; Braga, Erika M; Ricklefs, Robert E

    2012-07-01

    Arid zones of northern Venezuela are represented by isolated areas, important from an ornithological and ecological perspective due to the occurrence of restricted-range species of birds. We analysed the prevalence and molecular diversity of haemosporidian parasites of wild birds in this region by screening 527 individuals (11 families and 20 species) for parasite mitochondrial DNA. The overall prevalence of parasites was 41%, representing 17 mitochondrial lineages: 7 of Plasmodium and 10 of Haemoproteus. Two parasite lineages occurred in both the eastern and western regions infecting a single host species, Mimus gilvus. These lineages are also present throughout northern and central Venezuela in a variety of arid and mesic habitats. Some lineages found in this study in northern Venezuela have also been observed in different localities in the Americas, including the West Indies. In spite of the widespread distributions of some of the parasite lineages found in northern Venezuela, several, including some that are relatively common (e.g. Ven05 and Ven06), have not been reported from elsewhere. Additional studies are needed to characterize the host and geographical distribution of avian malaria parasite lineages, which will provide a better understanding of the influence of landscape, vector abundance and diversity, and host identity on haemosporidian parasite diversity and prevalence. PMID:22405405

  9. 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...

  10. 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

  11. 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

  12. 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.   

  13. 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.

  14. Two new Larainae species from Guayana region, Venezuela (Coleoptera: Elmidae).

    PubMed

    Laššová, Kristína; Ciampor, Fedor; Ciamporová-Zaťovičová, Zuzana

    2014-01-01

    Two new species of the subfamily Larainae (Insecta: Coleoptera: Elmidae), Hexanchorus angeli n. sp. and Hypsilara autanai n. sp., are described from Guyana region in Venezuela. We provide habitus photographs, detail drawings of both male and female genitalia, and description of morphological features important for discrimination of the new species. Molecular differences within genera were measured using 816bp fragment of mtDNA gene for cytochrome oxidase c subunit I. Sequence divergences among species are discussed. PMID:24872290

  15. 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

  16. 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.

  17. 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).

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Socio-Economic Aspects of National Communication Systems: III. Radio Broadcasting in Venezuela. Communication and Society, 12.

    ERIC Educational Resources Information Center

    Capriles, Oswaldo; And Others

    The third in a series that examines the role of radio broadcasting in the process of socioeconomic and cultural change in three countries with different types of broadcasting organization--Austria, Czechoslovakia, and Venezuela--this volume focuses on Venezuela. An overview of radio broadcasting in Venezuela describes various aspects and provides…

  3. 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... amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this request for information is required if a..., and Venezuela (67 FR 36149). Following the five-year reviews by Commerce and the Commission,...

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... Venezuela, pursuant to section 751(c) of the Tariff Act of 1930, as amended (the ``Act'').\\1\\ As a result of... revoked.\\2\\ On September 24, 2013, the ITC published its determination, pursuant to section 751(c) of the... FR 59897 (October 1, 2012). \\2\\ See Silicomanganese From India, Kazakhstan, and Venezuela:...

  5. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    PubMed

    Diazgranados, Mauricio; Morillo, Gilberto

    2013-01-01

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

  8. 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

  9. 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.

  10. Venezuela No. 1 oil import source in S. America

    SciTech Connect

    Not Available

    1992-08-10

    This paper reports that with the exception of Venezuela, the U.S. is likely to import much oil from South American countries through 2010, the General Accounting Office reports. GAO, a congressional watchdog agency, noted the U.S. imports about 4% of its oil from Colombia, Ecuador, and Trinidad and Tobago and possibly could import from Argentina, Bolivia, Brazil, Chile, and Peru in the future. It the the eight countries' crude oil reserves are expected to increase about 30% by 2000, then slide about 2% by 2010. Their oil production is expected to climb about 21% over 1990 by 2000, then level off until 2010.

  11. [Interpopulation reproductive synchrony of Agave cocui (Agavaceae) in Venezuela].

    PubMed

    Figueredo, Carmen J; Villegas, José Luis; Nassar, Jafet M

    2011-09-01

    Agave cocui (Agavaceae) is a species with broad distribution in arid and semiarid areas of Venezuela and Colombia. Despite of its ecological importance as a source of food for wildlife, and its economic value for production of a spirit drink, studies on the reproductive ecology of the species are relatively rare. In this study, we conducted a one-year evaluation of the flowering and fruiting phenology of A. cocui in the eight representative localities of the species' distribution in Venezuela. Within each study site, we chose an area with a minimum of 50 reproductive individuals and followed their reproductive phenophases with the help of binoculars, using six qualitative cathegories (emerging reproductive stalk, flowers, inmature fruits, mature fruits, bulbils and dry stalk) every two months. Emergence of the reproductive stalk in most of the examined populations began in September (rainy season), although this event delayed two months in a few populations. We detected significant negative correlations between precipitation and the percentage of flowering occurrence in four of the eight populations. Floral resources are available for flower visitors during approximately five months of the year (January-May). In most populations production of flowers initiated in January (dry season), and for Western Venezuela and Andean regions, the flowering main peak occurred in January. Localities from the Central and Eastern Coast exhibited the flowering peak in March, showing a delay of approximately two months with respect to other populations. Beginning of fruit set varied among localities from January to May; however, peak production of mature fruits concentrated in May, and fruit occurrence varied broadly between 5.2 and 85%. Bulbil production was detected in all populations and varied greatly among them (maximum percentage per population: 26.19-92.10%). High flowering synchronicity (Phenophase Overlapping Index: 0.756 and 0.999) was observed among all populations monitored in Western Venezuela, including the Andean localities. This condition might facilitate the existence of a nectar corridor from the Western Coast and nearby islands, to the Andean arid patches, which could be potentially used by nectar-feeding bats and birds dependent on agave flowers during part of the year. PMID:22017138

  12. [Gabriel Trompiz and the institutionalization of science in Venezuela].

    PubMed

    Osuna, A

    1991-01-01

    A testimonial to Dr. Trompiz, owing to the first lustrum of his death (August 23th, 1895). He was born in Falcon State (1907), graduated as medical doctor at UCV (1932) and postgraduated in Germany and Spain. Several analyses are made in order to consider D'Trompiz' position on the poor situation of science in Venezuela: 1) The historical comparison of science between Europe and Latin America; 2) The work presented by Garcia Gallo in the UNESCO Conference (Chile, 1965); 3) The H. Jaguaribe's work in CORDIPLAN (1974); 4) The Santis' evaluation on scientific investigation in our country. PMID:11633693

  13. Genetic variation of papaya ringspot virus in Venezuela.

    PubMed

    Fernández-Rodríguez, T; Rubio, L; Carballo, O; Marys, E

    2008-01-01

    The genetic variation of papaya ringspot virus (PRSV) in Venezuela was estimated by single strand conformation and nucleotide sequence analyses of two genomic regions of twenty-six isolates. These analyses showed that mutation, virus movement, selection, mixed infections and recombination contributed to shape the genetic variation observed. Phylogenetic analysis indicated that Venezuelan isolates were within a clade composed of isolates from the Americas and Australia. The genetic diversity of these isolates was sufficiently large that it must be taken into account when designing control strategies such as transgenic resistance and cross-protection. PMID:18030545

  14. 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

  15. 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

  16. AMINOGLYCOSIDE RESISTANCE GENES IN Pseudomonas aeruginosa ISOLATES FROM CUMANA, VENEZUELA

    PubMed Central

    TEIXEIRA, Bertinellys; RODULFO, Hectorina; CARREÑO, Numirin; GUZMÁN, Militza; SALAZAR, Elsa; DONATO, Marcos DE

    2016-01-01

    The enzymatic modification of aminoglycosides by aminoglycoside-acetyltransferases (AAC), aminoglycoside-adenyltransferases (AAD), and aminoglycoside-phosphotransferases (APH), is the most common resistance mechanism in P. aeruginosa and these enzymes can be coded on mobile genetic elements that contribute to their dispersion. One hundred and thirty seven P. aeruginosa isolates from the University Hospital, Cumana, Venezuela (HUAPA) were evaluated. Antimicrobial susceptibility was determined by the disk diffusion method and theaac, aadB and aph genes were detected by PCR. Most of the P. aeruginosa isolates (33/137) were identified from the Intensive Care Unit (ICU), mainly from discharges (96/137). The frequency of resistant P. aeruginosaisolates was found to be higher for the aminoglycosides tobramycin and amikacin (30.7 and 29.9%, respectively). Phenotype VI, resistant to these antibiotics, was the most frequent (14/49), followed by phenotype I, resistant to all the aminoglycosides tested (12/49). The aac(6´)-Ib,aphA1 and aadB genes were the most frequently detected, and the simultaneous presence of several resistance genes in the same isolate was demonstrated. Aminoglycoside resistance in isolates ofP. aeruginosa at the HUAPA is partly due to the presence of the aac(6´)-Ib, aphA1 andaadB genes, but the high rates of antimicrobial resistance suggest the existence of several mechanisms acting together. This is the first report of aminoglycoside resistance genes in Venezuela and one of the few in Latin America. PMID:27007556

  17. Intestinal helminths of capybaras, Hydrochoerus hydrochaeris, from Venezuela.

    PubMed

    Salas, Viviana; Herrera, Emilio A

    2004-10-01

    Quantitative parameters of intestinal helminth species and their potential relations to host characteristics in a population of capybaras (Hydrochoerus hydrochaeris) from Venezuela are reported for the first time. The intestines of 40 capybaras were collected during the 1992-annual harvest at Hato El Cedral. Six helminth species were found: 2 cestodes (Monoecocestus macrobursatum, M. hagmanni), 2 nematodes (Viannella hydrochoeri, Protozoophaga obesa), and 2 trematodes (Hippocrepis hippocrepis, Taxorchis schistocotyle). This is the first report for M. macrobursatum in Venezuela. Helminth abundance did not differ between sexes or age classes. Although patterns of distribution for all helminth species were overdispersed, the high prevalence found for all species (over 70%) and the high abundance observed for nematodes made it difficult to assess the effect that these helminths may produce on capybaras. Nevertheless, the negative associations found between the body condition of capybaras and helminth intensity for M. macrobursatum and V. hydrochoeri, might be pointing out potential host population regulatory role for these parasites which require further research. PMID:15558163

  18. Tectonic significance of paleomagnetic data from northern Venezuela

    NASA Astrophysics Data System (ADS)

    Skerlec, G. M.; Hargraves, R. B.

    1980-10-01

    A paleomagnetic study, mostly of basic intrusive rocks of Cretaceous and Tertiary age from northern Venezuela, includes 153 samples from 31 sites, of which only 6 sites failed to give consistent results. Fifteen sites within the Caribbean Mountains have easterly declinations with shallow, mixed positive and negative inclinations. These anomalous vectors are interpreted to be the result of tectonic rotation about vertical axes rather than to reflect anomalous magnetic field orientations associated with a polarity transition. Although these sample sites are within igneous intrusive bodies with no control on the original attitude during acquisition of the natural remanent magnetization, the relative conformity of data from numerous separate intrusions requires an average 90° megatectonic rotation of both the Villa de Cura and Tinaco tectonic belts of the Caribbean Mountains. On the other hand, seven sites from the Paraguana Peninsula (and two sites from the younger Tertiary Falcon basin) have southerly declination and positive inclination. These vectors can be explained by rotation about horizontal east-west axes during Cenozoic folding. A compilation of available paleomagnetic data from rocks of Cretaceous age in the Caribbean indicates that anomalous declinations are widespread in both the Greater Antilles and Caribbean Mountains. We interpret these data to support previous suggestions of megatectonic rotations of a more linear, north-south trending Mesozoic island arc system that included portions of the Greater Antilles and Caribbean Mountains of Venezuela.

  19. 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...

  20. 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.

  1. 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... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination To...

  2. 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

  3. 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

  4. Venezuela to develop second largest coal mine in South America

    SciTech Connect

    Ridley, R.S.

    1982-09-01

    Venezuela has plans to develop its coal resources in the state of Zulia. The Mino Paso Diablo project includes not only the coal mine but a steel complex and thermal power station. Design by Fluor is expected to be complete by mid-1983; first production is scheduled for 1986. Full production of 6 million tonnes/year will not be reached until the mid-1990s. The entire output is planned for domestic industrial use. At full production the mine will be the second largest coal mine in South America. The coal, which is similar to that of El Cerrejon, Columbia, 250 km away, has a calorific value of 13000 Btu/lb, ash 3%, sulphur 0.5% and free swelling index 5.

  5. Antiinflammatory activity of some medicinal plant extracts form Venezuela.

    PubMed

    Abad, M J; Bermejo, P; Carretero, E; Martínez-Acitores, C; Noguera, B; Villar, A

    1996-12-01

    Six medicinal plant extracts from Venezuela, used in traditional medicine, were investigated for their anti-inflammatory potential against adjuvant-carrageenan-induced inflammation (ACII). All doses expressed here are equivalents of dried starting plant materials (1.50 g dry plant/kg body wt.). The most interesting plant extracts were Synedrella nodiflora, and the hexane leaf extract of Bursera simaruba. In ACII, orally administered extracts (at doses 40 and 80 mg/kg, respectively), inhibited both the acute and chronic phases of this experimental model of inflammation, mainly the chronic phase. These extracts exhibited potent anti-inflammatory activity daily throughout the experiment, and were as effective as reference drugs, phenylbutazone (80 mg/kg) and indomethacin (3 mg/kg). PMID:9121169

  6. Simuliidae and their relation to human onchocerciasis in northern Venezuela

    PubMed Central

    Lewis, D. J.; de Aldecoa, R. Ibáñez

    1962-01-01

    A study of the vectors of onchocerciasis was carried out in 1961 in northern Venezuela at the request of the Venezuelan Government. This article, based on the report submitted, records various observations made—mainly during the dry season—on the identification and biology of the Simuliidae and on the possibilities of controlling them. Twelve Simulium forms were encountered; special attention was paid to the two common man-biting species; S. exiguum, which was abundant but of uncertain relation to onchocerciasis, and S. metallicum. The authors conclude that S. metallicum is the main or only vector in the area studied, but that S. exiguum might possibly also transmit onchocerciasis in certain places near large streams where it is found in great numbers. PMID:20604129

  7. 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.

  8. Low occurrence of Helicobacter DNA in tropical wild birds, Venezuela.

    PubMed

    García-Amado, María Alexandra; Sanz, Virginia; Martinez, Leoncia Margarita; Contreras, Mónica; Lentino, Miguel; Michelangeli, Fabian

    2013-10-01

    Enteric Helicobacter species (Helicobacter pullorum, Helicobacter pametensis, Helicobacter canadensis, Helicobacter anseris, and Helicobacter brantae) have been found in birds from temperate latitudes. We evaluated the occurrence of Helicobacter spp. in terrestrial wild birds from Venezuela. A fragment of 16S rRNA gene was amplified by PCR with Helicobacter genus-specific primers. Helicobacter spp. were detected in four of 80 fecal and in three of 42 intestinal tissue samples. Analyses of 16S and 23S rRNA gene sequences confirm for the first time the presence of Helicobacter in tropical terrestrial wild birds. However, the occurrence of Helicobacter was low, suggesting these bacteria may be uncommon in the populations we studied. PMID:24502727

  9. 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.

  10. 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 (φ) of the faster S wave and delay time (δt) 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 (φ,δt) were estimated when the summed eigenvalue ratio ∑(SNRi[λ2i(φ,δt)/λ1i(φ,δt)]) 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.

  11. 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.

  12. 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).

  13. 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.

  14. Surname frequency and the isonymy structure of Venezuela.

    PubMed

    Rodríguez-Larralde, Alvaro; Morales, Jorge; Barrai, Italo

    2000-05-01

    Isonymy in Venezuela was studied analyzing the surnames of 3.9 million adults 40 years and older, selected from the register of electors updated in 1991. The electors were not differentiated by sex and represented all 22 states of Venezuela and its Federal District. The states of Nueva Esparta, an island, and Mérida, in the Venezuelan Andes, have the highest coefficients of microdifferentiation (R(ST)) and of inbreeding due to random isonymy. The states of Miranda, Aragua, Carabobo, and the Federal District, which includes the capital, Caracas, or are very close to it, had the lowest R(ST) values. The weighted averages of Fisher's alpha, a measure of surname abundance, varied by state from 43 in Nueva Esparta to 226 in Miranda, with a value of 210 for the entire country, much smaller than those observed in Switzerland, Germany, or Italy (2,396, 2,855, and 5,855, respectively). The fact that 32% of the total Venezuelan sample has only 40 surnames easily accounts for this small alpha. The correlation between the Euclidean distance and the log of geographic distance between the capital cities of states in km is high and significant (r = 0.78). The dendrogram built with the Euclidean distance matrix indicates the presence of three main clusters. One is formed by 10 states located in the western-central part of the country. The states of Zulia and Falcón join this cluster at a distance of 0.54 Euclidean units. A second cluster is formed by Barinas and the three Andean states. After combining these two, a third cluster joins them, formed by six Eastern states. Finally, the state of Amazonas enters the dendrogram at a distance of 0.66 units. Am. J. Hum. Biol. 12:352-362, 2000. Copyright 2000 Wiley-Liss, Inc. PMID:11534025

  15. 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.

  16. 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…

  17. 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

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

    PubMed Central

    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

  19. 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

  20. 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

  1. 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

  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. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Montoya, Encarni; Rull, Valentí

    2011-11-01

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

  9. [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

  10. 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.

  11. International migration data: their problems and usefulness in Venezuela.

    PubMed

    Torrealba, R

    1987-01-01

    During the 1940s and 1950s Venezuela was an important destination for migrants from Southern Europe, a flow that disappeared almost entirely during the 1960s, to be replaced by border movements and the largely illegal migration of Colombians. The oil boom of the 1970s saw an increase of the latter, which may have subsided during the 1980s due to the more difficult economic conditions that have also led to significant emigration levels of Venezuelans and former immigrants. Methods of data collection systems that provide information on migrants include the National Population and Housing Census, the National Household Survey, migration surveys, arrival and departure statistics, registration systems operated by the Direccion General Sectorial de identificacion y Control de Extranjeros, the 1980 regularization drive, statistics gathered by the Ministry of Labor, and vital and civil registration statistics. The lack of effective coordination among the different government agencies gathering information and the administrative nature of the data collected give rise to problems of comparability. Mechanisms to publish and disseminate the data available are not well developed, so that researchers often have no access to potentially useful sources of information. Problems of timeliness in the publication of the most widely used information are also present, as is the large gap existing in data pertaining to emigration, be it of Venezuelan nationals or of immigrants leaving the country. PMID:12280916

  12. 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.

  13. Chemostratigraphy: Applications in the Tachira depression, Tachira State, Venezuela

    SciTech Connect

    Briceno, H.; Ostos, M.; Yoris, F.

    1996-08-01

    Rock analyses (40 chemical parameters) from densely sampled Cretaceous sections from La Luna, Navay, Aguardiente and Escandalosa formations in southwestern Venezuela, combined with multivariate statistical analysis, allowed statistical characterization of formations, environmentally meaningful clustering of correlated geochemical variables, as well as calculation of chemical accumulation rates. Chemofacies, defined from accumulation rates, were used for correlation and depositional environment definition. Organic matter maturity does not affect NiN ratios, but causes homogenization in Ca/Sr ratios. Th/V ratios clearly separate shelf vs. oceanic fades, closely matching those from biofacies analysis. Cycles in Th/V repeat every 60 in (Navay) to 20 in (La Luna), corresponding to Milankovitch climatic cycles. Shales (high Th/V) represent cooler-shallower sedimentation periods, and lodestones (low Th/V) represent warmer-deeper ones. Differences in accumulation rates were used for establishing changes in: source rock (La-Ce), either due to tectonism or variations in marine current pattern; redox conditions (Ni-V); clay mineralogy (Al-K); energy level (Al-Si); and salinity (Mg-Na). Finally, chemostratigraphy, combined with reliable structural and stratigraphical field data, has proven to be a powerful tool for unravelling tectono-stratigraphical histories.

  14. [Chromomycosis by Rhinocladiella aquaspera: The first case in Venezuela.].

    PubMed

    Pérez-Blanco, M; Fernández-Zeppenfeldt, G; Hernández, R; Yegres, F; Borelli, D

    1998-03-01

    A case of chromomycosis induced by Rhinocladiella aquaspersa is decribed in Falcon State, which is considered as the first case in Venezuela, and the fifth one in the whole world of this species of Rhinocladiella. The case was observed in a five year-old child from the south part of Falcon State. The child presented wounds of two years of duration, in his upper left limb. These wounds were characterized by queloide cicatrices, and contiguous nodules, with a scalyo-scab surface. The disease was diagnosed through direct observation of cells extracted from the wounds and cleared with potassium hydroxide at 10%. The identification of R. aquaspersa was made by 1) The isolation in culture, using Lactritmel, Sabouraud-agar and Sablac as culture media; and 2) By observation, in slide culture, of dissemination structures characterized by erect conidiophores which were either simple or branched. The thermo-tolerance test applied indicate an optimum development temperature of 28 degrees C. It was not possible to reproduce the illness in Balb/c mice. The patient showed an unsatisfactory response to Itraconazol medication and improvement to an external local application therapy. Up to the present time, 370 cases of chromomycosis have been studied in Falcon State, with 21 cases in children. The suggests the existence of a susceptibility to this kind of mycosis from childhood. PMID:17655407

  15. 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

  16. 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

  17. 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.

  18. Encounters with Science at ULA, Venezuela: An Incentive for Learning

    NASA Astrophysics Data System (ADS)

    Rosenzweig, P.

    2006-08-01

    In the School of Science of the Universidad de Los Andes (ULA), in Mérida, Venezuela, a very successful event focused on high school students and primary school students, was founded in 2000. The name of this event is "Encounters with Physics, Chemistry, Mathematics, and Biology" (hereinafter "Encounters with Science"), and it integrates these disciplines as well as Astronomy. Its main purpose is that young minds can become familiar with the methods of science inquiry and reasoning, and can understand the concepts and processes of the sciences through thoroughly prepared experiences. This flourishing program is continuing to grow and to become strong. As a matter of fact, in its sixth edition (2005), the number of high and elementary school students coming from all over the country, has reached the outstanding number of nine thousand. Among all the experiences that the students could be engaged in were many involving Astronomy. These experiences were prepared by professors, together with graduate and undergraduate students, who are pursuing their degrees in all branches of science including astronomy. Although there is this incredible team of faculties and graduate and undergraduate students working together; the target is the students of the high and elementary schools. We certainly focus on the engaging and encouraging of students to experience scientific work first hand. Additionally, our professors have prepared an excellent didactic material that can, together with the hour/class teaching, prepare high school and elementary school students for a better understanding of science; particularly, helping in this way for a better education in Astronomy. The main event of the Encounters lasts five days in the School of Science of ULA, but subsidiary events are spread all over the year and around the country. As a successful program, it can be interesting to see if other countries can adopt this method to recruit or to trigger the interest of students to pursue their studies in the Sciences.

  19. 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.

  20. A 75 ka Stalagmite Paleoclimate Record from Northern Venezuela

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    A stalagmite collected from Cueva Zarraga in the northern Venezuelan Andes was analyzed to determine local paleoclimatic history and help examine climate change in the Caribbean. Ages were determined by U/Th disequilibrium and the stalagmite shows a nearly complete record for ~ 75 ka. Two significant periods of non-deposition have been identified. The first period ranges between the Last Glacial Maximum at 19,820 ± 149 cal yr BP and a brief resumption of stalagmite growth at 15,409 ± 747 cal yr BP, likely representing the Bølling-Allerød interstadial. After the brief period of deposition, growth does not resume unil the Holocene at 10,408 ± 78 cal yr BP. Carbon and oxygen isotopes show a major depletion shift from the last glacial period to the Holocene, suggesting warmer and wetter conditions during the Holocene. The oxygen isotope depletion shift is also seen in the Cariaco Basin foraminifera record off the northern coast of Venezuela. While tempting to attribute δ13C depletion to decrease of the C4 plant contribution, there is no evidence that the area experience major vegetation changes. We attribute the δ13C depletion to enhanced recycling of soil CO2 resulting from canopy effects. Today, Cueva Zarraga is at the northern extent of the Inter-Tropical Convergence Zone (ITCZ). The cooler and drier conditions of the last glacial period suggest a southern displacement of the ITCZ. The close proximity of Cueva Zarraga to Cariaco Basin may allow for a high resolution tropical terrestrial and oceanic climatic response comparison.

  1. 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.

  2. 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 Jos Antonio

  3. 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…

  4. 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…

  5. 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,…

  6. 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…

  7. 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...: December 23, 2013. FOR FURTHER INFORMATION CONTACT: Irene Gorelik (Russia) or Kabir Archuletta...

  8. 78 FR 44969 - Ferrosilicon From Russia and Venezuela; Institution of Antidumping Duty Investigations and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

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

  9. An Innovative Project in Educational Technology: The Panama-Venezuela Project.

    ERIC Educational Resources Information Center

    Rojas, Alicia Mabel

    1980-01-01

    Describes a project which is being implemented in the field of educational technology in Panama and Venezuela. The project emphasizes inservice training of a cadre of professionals who will direct efforts to identify and resolve significant problems in education. (Author/CHC)

  10. 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…

  11. 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…

  12. The Cost Analysis of Learning at a Distance: Venezuela's Universidad Nacional Abierta.

    ERIC Educational Resources Information Center

    Rumble, Greville

    1982-01-01

    Examines the cost structure and future system costs of Venezuela's Universidad Nacional Abierta, compares them with the costs of other distance universities, and discusses the cost implications of media choice, size of program, and number of students. The usefulness of cost analysis and projection for decision making is also discussed. (EAO)

  13. 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.

  14. Universities, Public Policy and Economic Development in Latin America: The Cases of Mexico and Venezuela.

    ERIC Educational Resources Information Center

    Lorey, David E.

    1992-01-01

    Since establishment of national university systems in Mexico and Venezuela, three principal demands have dominated policy formation: government ideological demand; economic demand for expertise; and political and social demand for upward mobility through education. Tensions between these demands have stemmed from economic inability to sustain…

  15. Decentralization and Regionalization in Educational Administration: Comparisons of Venezuela, Colombia and Spain.

    ERIC Educational Resources Information Center

    Hanson, E. Mark

    A nation's transition from dictatorship to democracy generally involves institutional reform attempts with new priorities serving a wider range of people and goals. This study describes and compares the goals, means, and outcomes of administrative reforms in the public educational systems of three Hispanic nations (Venezuela, Colombia, and Spain).…

  16. 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…

  17. Spionidae (Annelida: Polychaeta) from the Parque Nacional Morrocoy, Falcón, Venezuela.

    PubMed

    Bone, D; Viéitez, J M

    2002-03-01

    Five species of polychaetes (Spionidae) were found associated to Thalassia testudinum meadows in Parque Nacional Morrocoy, Venezuela. We included a guide for their identification and present range extensions for the Venezuelan coasts and Southern Caribbean Sea. The species are: Dipolydora socialis, Prionospio (Minuspio) cirrifera, P. (Prionospio) fallax, P. (P.) steenstrupi, and Spio pettiboneae. PMID:12298268

  18. 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

  19. [Mycetoma: report of 3 cases in Falcón State, Venezuela].

    PubMed

    Pérez-Blanco, M; Hernández-Valles, R; Fernández-Zeppenfeldt, G; Yegres, F

    1996-03-01

    This is a report of three cases of mycetome studied in our laboratory during the last four years. We also informed about the evolution of the first case produced by Pyrenochaeta romeroi nova species reported by Borelli in 1959. All the patients were farmer men, 18, 42 and 54 years old, from the semiarid and subhumid zones of Falcon State, located on the northwest region of Venezuela. Clinically, all patients presented the mycetome syndrome (subcutaneous edema, sinus tract and "granules"), with a evolution of six months to three years. The lesions were localized in the inferior limbs in two of the patients and in the thorax in one of them. The clinical diagnose was confirmed by microbiological and mycological studies, isolating Nocardia brasiliensis in two cases and Madurella grisea in one. Two patients treated with Sulfas showed remission of the disease in a two years follow up. Including this report, 15 cases of mycetome have been reported in the Falcon State (Venezuela) in a period of thirty five years, representing only 9, 14% of the national casuistic. Actinomadura madurae and N. brasiliensis have been the most frequently isolated agents in this region. In order to determine the real endemicity of the mycetome in Venezuela, multidisciplinary clinical, inmunological, microbiological and epidemiological studies are recommended. According to the reported casuistic (15 cases), the mycetome should be a low frequency disease in Falcon State, Venezuela. We confirm that early diagnosis favors an efficient therapy. PMID:8920032

  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. 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......

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

    PubMed

    Reverón, Rafael Romero

    2014-03-01

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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Population differentiation of the Chagas disease vector Triatoma maculata (Erichson, 1848) from Colombia and Venezuela.

    PubMed

    Monsalve, Yoman; Panzera, Francisco; Herrera, Leidi; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-06-01

    The emerging vector of Chagas disease, Triatoma maculata (Hemiptera, Reduviidae), is one of the most widely distributed Triatoma species in northern South America. Despite its increasing relevance as a vector, no consistent picture of the magnitude of genetic and phenetic diversity has yet been developed. Here, several populations of T. maculata from eleven Colombia and Venezuela localities were analyzed based on the morphometry of wings and the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene sequences. Our results showed clear morphometric and genetic differences among Colombian and Venezuelan populations, indicating high intraspecific diversity. Inter-population divergence is suggested related to East Cordillera in Colombia. Analyses of other populations from Colombia, Venezuela, and Brazil from distinct eco-geographic regions are still needed to understand its systematics and phylogeography as well as its actual role as a vector of Chagas disease. PMID:27232127

  8. Barrio Adentro and the reduction of health inequalities in Venezuela: an appraisal of the first years.

    PubMed

    Armada, Francisco; Muntaner, Caries; Chung, Haejoo; Williams-Brennan, Leslie; Benach, Joan

    2009-01-01

    This article presents an update on the characteristics and performance of Venezuela's Bolivarian health care system, Barrio Adentro (Inside the Neighborhood). During its first five years of existence, Barrio Adentro has improved access and utilization of health services by reaching approximately 17 million impoverished and middle-class citizens all over Venezuela. This was achieved in approximately two years and provides an example of an immense "South-South" cooperation and participatory democracy in health care. Popular participation was achieved with the Comités de Salud (health committees) and more recently with the Consejos Comunales (community councils), while mostly Cuban physicians provided medical care. Examination of a few epidemiological indicators for the years 2004 and 2005 of Barrio Adentro reveals the positive impact of this health care program, in particular its primary care component, Barrio Adentro I. Continued political commitment and realistic evaluations are needed to sustain and improve Barrio Adentro, especially its primary care services. PMID:19326784

  9. Heavy metals in green mussel (Perna viridis) and oysters (Crassostrea sp.) from Trinidad and Venezuela.

    PubMed

    Rojas de Astudillo, L; Chang Yen, I; Agard, J; Bekele, I; Hubbard, R

    2002-05-01

    Heavy metal concentrations were monitored in edible soft tissues of shellfish from Trinidad and Venezuela. Oysters (Crassostrea sp.) and the green mussel (Perna viridis), which is a recently transplanted species to the Caribbean from the Far East, were collected at six locations in Venezuela and five in Trinidad, the latter along the coast line of the Gulf of Paria. Simple and low-cost methods of analysis were optimized and validated using standard reference materials. Cadmium, copper, lead, nickel, and zinc were analyzed by flame atomic absorption spectrometry. Mercury was determined by cold-vapor atomic absorption spectrometry. The present study has confirmed that oysters have a much greater capacity for accumulation of copper and zinc than does green mussel. In addition, concentrations of copper and zinc in oysters (Crassostrea sp.) at many of the sites in the Gulf of Paria exceeded local and international standards, whereas green mussel P. viridis contained generally acceptable levels for human consumption. PMID:11994781

  10. 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

  11. 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.

  12. Opportunities and constraints to biotechnological applications in the Caribbean: transgenic papayas in Jamaica and Venezuela.

    PubMed

    Fermin, Gustavo; Tennant, Paula

    2011-05-01

    In this opinion article, we briefly review the status of crop biotechnology research-with emphasis on the development of GM crops-in Jamaica and Venezuela. We focus on the transgenic papayas developed for both countries, and examine the factors hindering not only the development and application of this biotechnological commodity for the improvement of agricultural productivity, but also on the challenges influencing societal acceptance of the technology. PMID:21212960

  13. Hydrocarbon Magnetic Authigenesis Mechanisms in Well and Soil Samples: Review of Studies in Venezuela

    NASA Astrophysics Data System (ADS)

    Aldana, M.; Diaz, M.; Costanzo, V.

    2008-05-01

    In recent studies we have tried to establish the correlation between shallow micromagnetic anomalies from oil wells and soil samples, with the underlying reservoir. We have combined rock magnetic experiments with Electronic Paramagnetic Resonance (EPR) studies. Logs of Magnetic Susceptibility (MS), Extractable Organic Matter Concentration (EOMC) and Organic Matter Free Radical Concentration (OMFRC) have been compared. Additionally, rock magnetic and EPR experiments were carried out to identify the magnetic phases responsible for these anomalies. In wells from oil fields located in western Venezuela, MS and EOMC anomalies coincide at the same depth levels, and OMFRC anomalies lie close to them. These anomalies are associated to framboids of authigenic magnetite. In samples from eastern Venezuela oil fields, MS anomalies seem to be caused mainly by the presence of Fe sulphides (i.e. greigite). EOMC peaks do not coincide at the same depth levels of their MS counterparts. These results lead us to the conclusion that two different authigenic processes could operate. In western Venezuela, secondary magnetic minerals could be produced by the achievement of proper themochemical conditions, reached at shallow depth levels, combined with the presence of organic matter. The hydrocarbon gas leakage alters the organic matter, and a net electron transfer from this degraded matter to Fe(III) should occur, precipitating Fe(II) magnetic minerals (e.g. magnetite). Results from soil samples at a nearby prospective area suggest a similar process. In this case the alteration of organic matter has been observed via remote sensors. On the other hand, in eastern Venezuela oil fields, high concentrations of H2S at shallow depth levels, might allow the formation of secondary Fe-sulphides without the presence of organic matter. Different results for these two areas could be linked to their inherent distinct structural complexities and chemical properties of their hydrocarbons.

  14. 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

  15. 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…

  16. 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 Anzotegui, Gurico, and Sucre states. Just months later, Apure was also affected. Mrida and Tchira 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

  17. 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.

  18. Potential influence of climate variability on dengue incidence registered in a western pediatric Hospital of Venezuela.

    PubMed

    Herrera-Martinez, Aura D; Rodríguez-Morales, Alfonso J

    2010-08-01

    Climate change and variability is affecting human health and disease direct or indirectly through many mechanisms. Dengue is one those diseases that is strongly influenced by climate variability. In this study we assess potential associations between macroclimatic variation and dengue cases in a western pediatric hospital of Venezuela in an eight-year period. Between 2001 and 2008, 7,523 cases of dengue were reported in the Hospital Agustin Zubillaga, Barquisimeto, Venezuela. Climatic periods marked a difference of 23.15% in the mean incidence of cases, from El Niño weeks (-14.16% of cases below the mean incidence) to La Niña months (+8.99% of cases above it) (p=0.0001). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (ONI) (El Niño periods) and lower dengue incidence with higher values of ONI (La Niña periods) (p=0.0002). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in Venezuela. However, it is necessary to extend these studies in this and other countries in the region, because these models can be applied for surveillance as well for prediction of dengue. PMID:20962726

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

    NASA Astrophysics Data System (ADS)

    Niu, Fenglin; Bravo, Tammy; Pavlis, Gary; Vernon, Frank; Rendon, Herbert; Bezada, Maximiliano; Levander, Alan

    2007-11-01

    We have investigated crustal thickness and composition across the southeastern Caribbean plate boundary with the receiver function technique. We used teleseismic data recorded by a temporary broadband array deployed under the BOLIVAR project and the permanent national seismic network of Venezuela. We used the primary P-to-S conversion and crustal reverberations to estimate crustal thickness and average crustal VP/VS ratio over the region. We observe large variations in crustal thickness and Poisson's ratio. Estimated Moho depth ranges from ˜16 km beneath the southeastern Caribbean Sea to ˜52 km beneath northeastern Venezuela and the Venezuelan Andes. There is a good correlation between crustal structure and tectonic terranes. Data from the Precambrian Guayana Shield suggest that the underlying crustal structure is relatively uniform with a moderate thickness (˜37 km) and an intermediate composition. A thick crust is found below the foreland basins. The two mountain systems in northern Venezuela, the Serrania del Interior and the Serrania del Falcon, have a thin crust with arc composition and are likely dynamically supported by elastic rebound or underthrusting of the oceanic plateau that characterizes the southern Caribbean. On the other hand, the Venezuelan Andes and Perija Range on the western side of the country are probably isostatically balanced by thick crustal roots.

  20. [Genetic and demographic structure of the State of Aragua, Venezuela, estimated through the surnames].

    PubMed

    Rodríguez Larralde, A; Casique, J

    1993-01-01

    The genetic structure of the State of Aragua, Venezuela, has been studied through the analysis of surnames obtained from the register of electors. The analysis covered 23 counties and included a total of 99,593 individuals and 6,338 different surnames. Estimators of isolation, consanguinity, microdifferentiation and four measures of genetic distance, were studied. When our results were compared with those obtained in other States of Venezuela studied previously (Falcón, Lara, Mérida, Nueva Esparta and Yaracuy), Aragua appears as the State most open to new migrants, probably due to its nearness to Caracas, Venezuela's capital city. Within Aragua, the counties most isolated are Choronií, Ocumare de la Costa and Tovar, while those less isolated are El Limón, Turmero, La Victoria, San Mateo and Cagua. The correlations between the logarithmic transformations of genetic and geographic distances were all significant, revealing surname differentiation by distance. The dendrogram built with the Euclidean distance matrix shows a first group of counties formed by those localized towards the central portion of the State, to which southern counties are added. Choroní and Ocumare de la Costa form a group which enters the dendrogram just before Tovar, the last county to be included in the analysis. Seven surnames with a focal distribution within the State were identified: Ayala and Calanche in Choroní; Kanzler, Misle and Ruh in Tovar; Lira in San Mateo and Santaella in Barbacoas. PMID:7483965

  1. Combined Rock Magnetic and Dielectric studies applied to stratigraphic and archeological problems in Venezuela

    NASA Astrophysics Data System (ADS)

    Costanzo-Alvarez, V.; Aldana, M.; Suarez, N.

    2007-05-01

    In the last few years the paleomagnetism research group, at the Universidad Simon Bolivar in Caracas (Venezuela), has undertaken combined studies of rock magnetism (e.g. natural magnetic remanence, magnetic susceptibility, hysteresis parameters etc.) and dielectric properties (maximum current depolarization temperatures and average activation energies) in Cretaceous and Paleogene sedimentary sequences from eastern and western Venezuela. Our main goal has been to find new ways of defining physical markers, in fossil- poor sedimentary rocks, for stratigraphic correlations. Magneto/dielectric characterizations of these rocks have proved also useful identifying lithological discontinuities and paleoenvironmental changes. More recently these two-fold technique have been extended to archeological materials (potsherds) from a series of Venezuelan islands, in order to track down clay sources and find out about different stages of pottery craftsmanship. Magneto/Dielectric characterization of archeological potsherds seems to allow the tracing of their provenance from various mainland prehistoric settlements of distinct Venezuelan amerindian groups. In this paper we present a comprehensive review of this research applied to a contact between two sedimentary formations in eastern Venezuela (Cretaceous Chimana/Querecual) and a number of pottery samples with diverse stylistic features excavated in a single archeological site from Los Roques islands.

  2. Comparative development and impact of transgenic papayas in Hawaii, Jamaica, and Venezuela.

    PubMed

    Fermín, Gustavo; Tennant, Paula; Gonsalves, Carol; Lee, David; Gonsalves, Dennis

    2005-01-01

    We present data concerning the creation of transgenic papayas resistant to Papaya ringspot virus (PRSV) and their adoption by three different countries: the United States (e.g., Hawaii), Jamaica, and Venezuela. Although the three sets of transgenic papayas showed effective resistance to PRSV, the adoption rate in each country has varied from full utilization in Hawaii to aggressive testing but delay in deregulating of the product in Jamaica to rejection at an early stage in Venezuela. Factors that contributed to the rapid adoption in Hawaii include a timely development of the transgenic product, PRSV causing severe damage to the papaya industry, close collaboration between researchers and the industry, and the existence of procedures for deregulating a transgenic product. In Jamaica, the technology for developing the initial field-testing of the product progressed rather rapidly, but the process of deregulation has been slowed down owing to the lack of sustained governmental efforts to complete the regulatory procedures for transgenic crops. In Venezuela, the technology to develop and greenhouse test the transgenic papaya has moved abreast with the Jamaica project, but the field testing of the transgenic papaya within the country was stopped very early on by actions by people opposed to transgenic products. The three cases are discussed in an effort to provide information on factors, other than technology, that can influence the adoption of a transgenic product. PMID:15310936

  3. 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

  4. 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.

  5. Characterization and engineering of the ethylmalonyl-CoA pathway towards the improved heterologous production of polyketides in Streptomyces venezuelae.

    PubMed

    Jung, Won Seok; Kim, Eunji; Yoo, Young Ji; Ban, Yeon Hee; Kim, Eun Ji; Yoon, Yeo Joon

    2014-04-01

    Streptomyces venezuelae has an inherent advantage as a heterologous host for polyketide production due to its fast rate of growth that cannot be endowed easily through metabolic engineering. However, the utility of S. venezuelae as a host has been limited thus far due to its inadequate intracellular reserves of the (2S)-ethylmalonyl-CoA building block needed to support the biosynthesis of polyketides preventing the efficient production of the desired metabolite, such as tylactone. Here, via precursor supply engineering, we demonstrated that S. venezuelae can be developed into a more efficient general heterologous host for the quick production of polyketides. We first identified and functionally characterized the ethylmalonyl-CoA pathway which plays a major role in supplying the (2S)-ethylmalonyl-CoA extender unit in S. venezuelae. Next, S. venezuelae was successfully engineered to increase the intracellular ethylmalonyl-CoA concentration by the deletion of the meaA gene encoding coenzyme B₁₂-dependent ethylmalonyl-CoA mutase in combination with ethylmalonate supplementation and was engineered to upregulate the expression of the heterologous tylosin PKS by overexpression of the pathway specific regulatory gene pikD. Thus, a dramatic increase (∼10-fold) in tylactone production was achieved. In addition, the detailed insights into the role of the ethylmalonyl-CoA pathway, which is present in most streptomycetes, provides a general strategy to increase the ethylmalonyl-CoA supply for polyketide biosynthesis in the most prolific family of polyketide-producing bacteria. PMID:24413979

  6. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  8. Current status of the New World screwworm Cochliomyia hominivorax in Venezuela.

    PubMed

    Coronado, A; Kowalski, A

    2009-06-01

    The geographical distribution and seasonality of the New World screwworm (NWS), Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae), were monitored through the use of sentinel animals as part of a co-ordinated programme involving veterinarians and farmers, as well as undergraduate students and teachers from veterinary colleges in Venezuela. This surveillance activity made it possible to collect NWS egg masses or larvae from all 23 states in the country and to determine that the rainy season has a strong positive influence on the number of cases of myiasis caused by C. hominivorax in dogs. In addition, efforts were made to obtain the co-operation of the public health service in order to document the extent of human myiasis in the western-central region of Venezuela. Preliminary results revealed 241 cases over a 7-year period, with cases reported in infants as well as in elderly people. Larvae causing myiasis, other than C. hominivorax, were collected from primary myiasis in rabbit (Lucilia eximia [Wiedemann]), dog (an unidentified sarcophagid species), birds (Philornis sp.) and wild mice (Cuterebra sp.). The economic impact of NWS in Venezuela has not been calculated in terms of loss of milk and meat production, damage to hides or death of animals. Control costs (e.g. cost of larvicides) have been estimated at US$ 2 m per year. Control of myiasis in animals is achieved through the use of chemical compounds, mainly organophosphorus (OP) compounds, macrocyclic lactones and, more recently, a foamy spray based on spinosad. Concerns about insecticide resistance to OP compounds have been raised. PMID:19335837

  9. 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.

  10. 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.

  11. [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

  12. [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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. [A new species of amphipod crustacean of the genus Amphilochus (Crustacea, Amphipoda, Amphilochidae) from Venezuela].

    PubMed

    Martín, A; Ortiz, M; Atienza, D

    2001-01-01

    A new species of amphipod Crustacea (Gammaridea, Amphilochidae) of the genus Amphilochus Bate, 1862, is described. The species was collected in Phallusia nigra (Savigny, 1816) at depths between 0 and 2 m, in the pier piles of the Marina El Ancla and Los Manglares gas station in Morrocoy National Park (Falcón State, Venezuela), during the months of June and July 1998. The main differences between A. ascidicola new species and all others species of the genus recorded from the Gulf of Mexico and the Caribbean Sea, are given. PMID:11510426

  19. 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,…

  20. Short report: socioeconomic and seasonal variations of Helicobacter pylori infection in patients in Venezuela.

    PubMed

    Domínguez-Bello, María G; Beker, Bernardo; Guelrud, Moisés; Vivas, Jorge; Peraza, Simón; Pérez, María E; Pericchi, Luis R

    2002-01-01

    Infection by Helicobacter pylori is recognized as a risk factor for gastric cancer and peptic ulcer disease. Venezuela has regions with different gastric cancer risks; the Andean region has the highest gastric cancer mortality in the country. We performed a cross-sectional study on 357 patients who underwent endoscopy attending 2 private (n = 76) and one public hospital in Caracas, Venezuela (n = 215), and one public hospital in the Andes (n = 66) to determine H. pylori infection (by a rapid biopsy urease test and histology). The proportion of infected patients in Caracas was significantly higher in public hospitals (72%) than in private hospitals (46%; P = 0.00001), and there was no significant variation the Andes and Caracas (P = 0.7001). When analyzing the data from the public hospital in Caracas, we found that the frequency of infected patients was significantly higher during the rain (96%) than during the dry months (70%, P = 0.00000001). Differences in prevalence of infection in symptomatic patients was not related to the risk of gastric cancer but to socioeconomic differences. Rain-dependent factors that may be exacerbating the clinical activity of nonulcer dyspepsia in people infected with H. pylori deserve further study. PMID:12135267

  1. 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.

  2. Spinocerebellar ataxias in Venezuela: genetic epidemiology and their most likely ethnic descent.

    PubMed

    Paradisi, Irene; Ikonomu, Vassiliki; Arias, Sergio

    2016-03-01

    Dominantly inherited ataxias (spinocerebellar ataxias, SCAs) are a genetically heterogeneous group of neurologic diseases characterized by progressive cerebellar and spinal tract degeneration with ataxia and other signs, common to all known subtypes. Several types are relatively frequent worldwide, but in several countries, one specific SCA may show a higher prevalence owing to founder phenomena. In Venezuela, genetic epidemiological features of SCAs have been assessed during the last 30 years; mutations in ATXN1 (SCA1), ATXN2 (SCA2), ATXN3 (SCA3), CACNA1A (SCA6), ATXN7 (SCA7), ATXN8 (SCA8), ATXN10 (SCA10), TBP (SCA17) and ATN1 (dentatorubral pallidoluysian atrophy, DRPLA) loci were searched among 115 independent families. SCA7 was the most frequent subtype (26.6%), followed by SCA3 (25.0%), SCA2 (21.9%), SCA1 (17.2%), SCA10 (4.7%) and DRPLA (3.1%); in 43% of the families, the subtype remained unidentified. SCA7 mutations displayed strong geographic aggregation in two independent founder foci, and SCA1 showed a very remote founder effect for a subset of families. SCA10 families were scattered across the country, but all had an identical in-phase haplotype carried also by Mexican, Brazilian and Sioux patients, supporting a very old common Amerindian origin. Prevalence for dominant SCAs in Venezuela was estimated as 1:25 000 nuclear families, provenances of which are either Caucasoid, African or Amerindian. PMID:26538302

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Comparative federal health care policy: evidence of collaborative federalism in Pakistan and Venezuela.

    PubMed

    Baracskay, Daniel

    2013-01-01

    Collaborative federalism has provided an effective analytical foundation for understanding how complex public policies are implemented in federal systems through intergovernmental and intersectoral alignments. This has particularly been the case in issue areas like public health policy where diseases are detected and treated at the local level. While past studies on collaborative federalism and health care policy have focused on federal systems that are largely democratic, little research has been conducted to examine the extent of collaboration in authoritarian structures. This article applies the collaborative federalism approach to the Islamic Republic of Pakistan and the Bolivarian Republic of Venezuela. Evidence suggests that while both nations have exhibited authoritarian governing structures, there have been discernible policy areas where collaborative federalism is embraced to facilitate the implementation process. Further, while not an innate aspect of their federal structures, Pakistan and Venezuela can potentially expand their use of the collaborative approach to successfully implement health care policy and the epidemiological surveillance and intervention functions. Yet, as argued, this would necessitate further development of their structures on a sustained basis to create an environment conducive for collaborative federalism to flourish, and possibly expand to other policy areas as well. PMID:24350551

  8. [Seasonality of rotavirus infection in Venezuela: relationship between monthly rotavirus incidence and rainfall rates].

    PubMed

    González Chávez, Rosabel

    2015-09-01

    In general, it has been reported that rotavirus infection was detected year round in tropical countries. However, studies in Venezuela and Brazil suggest a seasonal behavior of the infection. On the other hand, some studies link infection with climatic variables such as rainfall. This study analyzes the pattern of behavior of the rotavirus infection in Carabobo-Venezuela (2001-2005), associates the seasonality of the infection with rainfall, and according to the seasonal pattern, estimates the age of greatest risk for infection. The analysis of the rotavirus temporal series and accumulated precipitation was performed with the software SPSS. The infection showed two periods: high incidence (November-April) and low incidence (May-October). Accumulated precipitation presents an opposite behavior. The highest frequency of events (73.8% 573/779) for those born in the period with a low incidence of the virus was recorded at an earlier age (mean age 6.5 +/- 2.0 months) when compared with those born in the station of high incidence (63.5% 568/870, mean age 11.7 +/- 2.2 months). Seasonality of the infection and the inverse relationship between virus incidence and rainfall was demonstrated. In addition, it was found that the period of birth determines the age and risk of infection. This information generated during the preaccine period will be helpful to measure the impact of the vaccine against the rotavirus. PMID:26710540

  9. 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

  10. [Molecular and serological diagnosis of a dengue outbreak in Coro, Falcón state, Venezuela].

    PubMed

    Moros, Zoila Caridad; Abad, María Jesús; Arsenak, Miriam; Martínez, Dilia; Cierco, Maria Magdalena; Costagliola, Asunta; Urbina, Leyda; Taylor, Peter; Liprandi, Ferdinando; Pujol, Flor Helene

    2003-09-01

    Dengue virus (DV) is responsible for a spectrum of diseases, from a self-limited fever disease (DF, dengue fever) to the more severe forms of hemorrhagic fever/dengue shock syndrome (DHF/DSS). The aim of this study was the serological and molecular confirmation of an outbreak of dengue in Falcon state, Venezuela. A total of 54 sera from patients with clinical diagnosis of DV infection were analyzed by an enzyme immunoassays developed in Venezuela (ELISA -IgM e -IgG) and by PCR. From them, 78% exhibited DV infection (PCR+ y/o IgM+), 48% exhibited viremia by PCR and 57% were positive to IgM. An interesting observation was the high percent (76%) of patients with past or secondary infection (IgG positive), which included all the patients exhibiting clinical symptoms of DHF (n = 8). From the PCR positive sera, serotype 1 was found in 27%, serotype 2 in 54% and serotype 4 in 19%. No serotype 3 was found circulating in this population, although this serotype was already circulating in the nearby island of Aruba. The combination of serological and molecular methods allow us to obtain a fairly precise information of this outbreak. PMID:14552060

  11. 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

  12. 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.

  13. Situation Report--Burma, Chile, German Democratic Republic, Indonesia, Jamaica, Poland, Singapore, St. Christopher/Nevis, Trinidad & Tobago, Venezuela.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in ten foreign countries are presented in these situation reports. Countries included are Burma, Chile, German Democratic Republic, Indonesia, Jamaica, Poland, Singapore, St. Christopher/Nevis, Trinidad and Tobago, and Venezuela. Information is provided, where appropriate and available, under two…

  14. 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,…

  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. 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

  17. Molecular and Antigenic Comparison of Ehrlichia canis Isolates from Dogs, Ticks, and a Human in Venezuela

    PubMed Central

    Unver, Ahmet; Perez, Miriam; Orellana, Nelson; Huang, Haibin; Rikihisa, Yasuko

    2001-01-01

    We previously culture isolated a strain of Ehrlichia canis, the causative agent of canine ehrlichiosis, from a human in Venezuela. In the present study, we examined whether dogs and ticks are infected with E. canis in Venezuela and, if so, whether this is the same strain as the human isolate. PCR analysis using E. canis-specific primers revealed that 17 of the 55 dog blood samples (31%) and all three pools of four Rhipicephalus sanguineus ticks each were positive. An ehrlichial agent (Venezuelan dog Ehrlichia [VDE]) was isolated and propagated in cell culture from one dog sample and was further analyzed to determine its molecular and antigenic characteristics. The 16S rRNA 1,408-bp sequence of the new VDE isolate was identical to that of the previously reported Venezuelan human Ehrlichia isolate (VHE) and was closely related (99.9%) to that of E. canis Oklahoma. The 5′ (333-bp) and 3′ (653-bp) sequences of the variable regions of the 16S rRNA genes from six additional E. canis-positive dog blood specimens and from three pooled-tick specimens were also identical to those of VHE. Western blot analysis of serum samples from three dogs infected with VDE by using several ehrlichial antigens revealed that the antigenic profile of the VDE was similar to the profiles of VHE and E. canis Oklahoma. Identical 16S rRNA gene sequences among ehrlichial organisms from dogs, ticks, and a human in the same geographic region in Venezuela and similar antigenic profiles between the dog and human isolates suggest that dogs serve as a reservoir of human E. canis infection and that R. sanguineus, which occasionally bites humans residing or traveling in this region, serves as a vector. This is the first report of culture isolation and antigenic characterization of an ehrlichial agent from a dog in South America, as well as the first molecular characterization of E. canis directly from naturally infected ticks. PMID:11473993

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

    PubMed

    Herrera, Leidi

    2014-01-01

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

  19. 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.

  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. 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.

  2. CTX-M-14 β-lactamase-producing Citrobacter freundii isolated in Venezuela

    PubMed Central

    2011-01-01

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

  3. 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

  4. Petroleum-processing projects in Venezuela: Definitional-Mission report. Export trade information

    SciTech Connect

    Grady, R.B.; Shrivastava, V.K.

    1992-02-01

    The U.S. Trade and Development Program (TDP) contracted a Definitional Mission to evaluate the prospects of TDP funding feasibility studies of three petroleum refining projects for Maraven, an integrated oil subsidiary of Petroleos de Venezuela, S.A. (PDVSA). Maraven has requested TDP support for feasibility studies of the following projects: Zuata (Orinoco Belt) Extra Heavy Crude Upgrading, Boscan Heavy Crude Gasification Complex, and High Quality Lube Oil Base Manufacting Project. The ratio of U.S. export potential to the cost of the feasibility studies is very high (350:1 for the lube project to 1600:1 for the heavy crude projects). Even assuming relatively low probabilities of timely implementation, the projects meet TDP potential export benefit/cost requirements. Therefore, the study recommends that TDP support all three projects at a level of 50 percent of the estimated cost.

  5. [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

  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. 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.

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

    PubMed

    Maier, Crystal A

    2013-01-01

    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

  9. [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

  10. [Morphometry of Sanguinolaria cruenta (Bivalvia: Psammobidae) in Tucacas Beach, Falcón, Venezuela)].

    PubMed

    Martín, A; Díaz Díaz, Y J; Paredes, C

    2001-01-01

    Three hundred and twelve shells of Sanguinolaria cruenta were collected in May 1999 in a sandy beach in Tucacas, Falcón, Venezuela. For each shell, antero-posterior length (Lap), overall height (Al), wide (An), weight (Pe), valves area (Arv), anterior length (La) and dorsal height (Ad) were measured. The descriptive statistic of the studied individuals, allows to appreciate that the variables that are good as parameters for the taxonomic description of S. cruenta are: Lap, Al, An, La y Ad, given their little variability. The maximum class frequencies is 41-70 mm for Lap (91% of the population). Analysis of data determined relationships of Lap to An, Lap to La were isometric (Lap = 0.98078 An + 1.50456 and Lap = 0.98052 La + 5.25840, respectively), whereas the other relationships indicate allometric growth. PMID:12189817

  11. 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

  12. First report of metallo-β-lactamases producing Enterobacter spp. strains from Venezuela.

    PubMed

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

    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 blaVIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacae showed blaTEM-1, but only one showed blaCTX-M-15 gene, while no blaSHV was detected. PMID:24553611

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

    PubMed

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

    2014-12-01

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

  14. Access to and coverage of renal replacement therapy in minorities and ethnic groups in Venezuela.

    PubMed

    Bellorin-Font, Ezequiel; Pernalete, Nidia; Meza, Josefina; Milanes, Carmen Luisa; Carlini, Raul G

    2005-08-01

    Access to and coverage of renal replacement therapy in minorities and ethnic groups in Venezuela. Numerous studies have documented the presence of racial and minority disparities regarding the impact of renal disease and access to renal replacement therapy (RRT). This problem is less well documented in Latin America. Venezuela, like most countries in the region, is subject to severe constraints in the allocation of resources for high-cost chronic diseases, which limits the access of patients with chronic kidney disease to RRT. Although access to health care is universal, there is both a deficit in coverage and disparity in the access to RRT, largely as a result of socioeconomic limitations and budget constrains. With current rising trends of the incidence of end-stage renal disease (ESRD) and costs of medical technology, the long-term goal of complete RRT coverage will become increasingly out of reach. Current evidence suggests that prevention of progression of renal disease is possible at relatively low cost and broad coverage. Based on this evidence, the Ministry of Health has redesigned its policy with respect to renal disease based on 4 elements: 1. Prevention by means of early detection and referral to multidisciplinary health teams, as well as promotion of health habits in the community. 2. Prevention of progression of renal disease by pharmacologic and nonpharmacologic means. 3. An increase in the rate of coverage and reduction of disparities in the access to dialysis. 4. An increase in the rates of renal transplantation through better organ procurement programs and reinforcement of transplant centers. However, the projected increase in the number of patients with ESKD receiving RRT will represent a serious burden to the health care system. Therefore, implementation of these policies will require the involvement of international agencies as well as an adequate partnership between nephrologists and health care planners, so that meeting the increasing demands of ESKD programs may be balanced with other priorities of our national health system. PMID:16014094

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

    SciTech Connect

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

    1993-02-01

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

  16. 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.

  17. [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

  18. [Distribution and density of two holothurian species in Cubagua Island, Venezuela].

    PubMed

    Tagliafico, Alejandro; Rangel, María Salomé; Rago, Néstor

    2011-06-01

    Holothurian populations in the Caribbean have been significantly depleted in some areas, and others are still in danger to satisfy international markets. In Venezuela, this marine resource has been illegally exploited since the early 1990s. To contribute with their management and protection, this work analyzed the distribution, abundance and population structure of two commercial holothurians Isostichopus badionotus and Holothuria mexicana in Cubagua Island shores. A total of 52 stations were studied around the island during the year 2008. Surveys included visits to each station, for which a band transect of 50 m2 with four replicates were carried out. The results show that I. badionotus has a higher distribution on the East coast of the island, and is found over Thalassia testudinum beds or bivalve molluscs aggregations, with an average density of 0.011 ind/m2, C.I. 95% = 0.005-0.017, n = 122, and a general abundance estimated in 117 ind/ha. H. mexicana has been practically depleted (0.001 ind/m2 C.I. 95% = 0.0002-0.0013, 7.7 ind/ha, n = 8). We recommend the maintenance of the total ban adopted in 1997 to assure the protection of these species, mainly because no previous data supported the start of the fishery, and also, because the current densities are still very low when compared to other areas in Venezuela and the Caribbean. These are animals easy to catch, susceptible to overfishing, and with a very low recovery rate; thus, more control is required from the local authorities. PMID:21721242

  19. Molecular epidemiology of enteric viruses in children with sporadic gastroenteritis in Valencia, Venezuela.

    PubMed

    González, Germán G; Liprandi, Ferdinando; Ludert, Juan E

    2011-11-01

    The epidemiology and clinical symptoms in infants and young children with acute sporadic viral gastroenteritis due to viral etiologies other than rotaviruses have not been studied thoroughly in developing countries. Fecal specimens from 480 children <5 years of age who were admitted to a large children's hospital in the city of Valencia, Venezuela, with acute diarrhea during January to December 2003 were collected and screened by ELISA and RT-PCR for rotavirus, adenovirus, norovirus, sapovirus, and astrovirus. Viral isolates were partially characterized by phylogenetic analysis. Norovirus viral load was determined by qRT-PCR. Viruses were identified in 205 (43%) of the 480 stool samples collected. Rotavirus was the virus detected most frequently (21%), followed by norovirus (13%), adenovirus (5%), sapovirus (3%), and astrovirus (2%). Viral infection rates were highest in the 6- to 11-month-old group (49%) and lowest in children >24 months old. Norovirus GII was more prevalent (90%) than GI (10%). Enteric adenovirus (serotypes 40/41) was present in 43% of the adenovirus-positive samples. Rotavirus infection caused more severe clinical symptoms than the other viruses detected, with more vomiting (84%) and dehydration (11%) that led to hospital admission of 20% of the children with acute gastroenteritis. Rotavirus and norovirus showed marked and opposite seasonal patterns. No association was observed between disease severity and viral load in children infected with norovirus. These results not only confirm the impact of rotavirus infection in Venezuela but also indicate that other enteric viruses, especially noroviruses, contribute significantly to sporadic acute gastroenteritis and to the burden of disease. PMID:21915873

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. A new species of Hypocristata (Nematoda, Trichostrongyuna, Heligmosomoidea) a parasite of Sigmodon hispidus (Cricetidae, Sigmodontinae) from Venezuela.

    PubMed

    Durette-Desset, M C; Guerrero, R A

    2006-09-01

    Description of Hypocristata tercera n. sp. (Heligmonellidae, Nippostrongylinae) a parasite of the small intestine of Sigmodon hispidus (Rodent, Sigmodontinae) from Venezuela. Two other species were described in the genus, both from Colombia and parasitic in Sigmodontinae. H. thomosomysi Durette-Desset, 1970, a parasite of Thomasomys sp. has about the same number of cuticular ridges at mid-body but differs by ridges having chitinoid struts, a caudal bursa pattern of type 2-2-1 (vs 1-3-1). H. anguillula Durette-Desset, 1970, a parasite of Sigmodontomys alfari (= Nectomys alfari) has the same caudal bursa pattern (type 1-3-1) but differs by the presence of ridges at mid-body in both sexes (absent at that level in H. tercera) and by ridges having chitinoid struts in female. This is the first report of the genus Hypocristata Durette-Desset, 1971 in Venezuela and in the genus Sigmodon (Sigmodontinae). PMID:17007211

  6. Varying genetic diversity of Papaya ringspot virus isolates from two time-separated outbreaks in Jamaica and Venezuela.

    PubMed

    Chin, M; Rojas, Y; Moret, J; Fermin, G; Tennant, P; Gonsalves, D

    2007-01-01

    Coat protein sequences of 22 Papaya ringspot virus isolates collected from different locations in Jamaica and Venezuela in 1999 and 2004, respectively, were determined and compared with sequences of isolates from earlier epidemics in 1990 and 1993. Jamaican isolates collected in 1999 exhibited nucleotide sequence identities between 98 and 100% but shared lower identities of 92.2% with an isolate collected in 1990. Isolates from the 2004 epidemic in Venezuela exhibited more heterogeneity, with identities between 88.7 and 98.8%. However, isolates collected in 1993 were more closely related (97.7%). The viral populations of the two countries are genetically different and appear to be changing at different rates; presumably driven by introductions, movement of plant materials, geographical isolation, and disease management practices. PMID:17668274

  7. 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

  8. 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

  9. 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

  10. 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

  11. Seasonal prediction of lightning activity in North Western Venezuela: Large-scale versus local drivers

    NASA Astrophysics Data System (ADS)

    Muñoz, Á. G.; Díaz-Lobatón, J.; Chourio, X.; Stock, M. J.

    2016-05-01

    The Lake Maracaibo Basin in North Western Venezuela has the highest annual lightning rate of any place in the world (~ 200 fl km- 2 yr- 1), whose electrical discharges occasionally impact human and animal lives (e.g., cattle) and frequently affect economic activities like oil and natural gas exploitation. Lightning activity is so common in this region that it has a proper name: Catatumbo Lightning (plural). Although short-term lightning forecasts are now common in different parts of the world, to the best of the authors' knowledge, seasonal prediction of lightning activity is still non-existent. This research discusses the relative role of both large-scale and local climate drivers as modulators of lightning activity in the region, and presents a formal predictability study at seasonal scale. Analysis of the Catatumbo Lightning Regional Mode, defined in terms of the second Empirical Orthogonal Function of monthly Lightning Imaging Sensor (LIS-TRMM) and Optical Transient Detector (OTD) satellite data for North Western South America, permits the identification of potential predictors at seasonal scale via a Canonical Correlation Analysis. Lightning activity in North Western Venezuela responds to well defined sea-surface temperature patterns (e.g., El Niño-Southern Oscillation, Atlantic Meridional Mode) and changes in the low-level meridional wind field that are associated with the Inter-Tropical Convergence Zone migrations, the Caribbean Low Level Jet and tropical cyclone activity, but it is also linked to local drivers like convection triggered by the topographic configuration and the effect of the Maracaibo Basin Nocturnal Low Level Jet. The analysis indicates that at seasonal scale the relative contribution of the large-scale drivers is more important than the local (basin-wide) ones, due to the synoptic control imposed by the former. Furthermore, meridional CAPE transport at 925 mb is identified as the best potential predictor for lightning activity in the Lake Maracaibo Basin. It is found that the predictive skill is slightly higher for the minimum lightning season (Jan-Feb) than for the maximum one (Sep-Oct), but that in general the skill is high enough to be useful for decision-making processes related to human safety, oil and natural gas exploitation, energy and food security.

  12. Characterization of enzootic foci of Venezuelan equine encephalitis virus in western Venezuela.

    PubMed

    Barrera, R; Torres, N; Freier, J E; Navarro, J C; García, C Z; Salas, R; Vasquez, C; Weaver, S C

    2001-01-01

    The distribution of the sylvatic subtype ID Venezuelan equine encephalitis (VEE) viruses in the lowland tropical forests of western Venezuela was investigated using remote sensing and geographic information system technologies. Landsat 5 Thematic Mapper satellite imagery was used to study the reflectance patterns of VEE endemic foci and to identify other locations with similar reflectance patterns. Enzootic VEE virus variants isolated during this study are the closest genetic relatives of the epizootic viruses that emerged in western Venezuela during 1992-1993. VEE virus surveillance was conducted by exposing sentinel hamsters to mosquito bites and trapping wild vertebrates in seven forests identified and located by means of the satellite image. We isolated VEE viruses from 48 of a total of 1,363 sentinel hamsters in two of the forests on six occasions, in both dry and wet seasons. None of the 12 small vertebrates captured in 8,190 trap-nights showed signs of previous VEE virus infection. The satellite image was classified into 13 validated classes of land use/vegetation using unsupervised and supervised techniques. Data derived from the image consisted of the raw digital values of near- and mid-infrared bands 4, 5, and 7, derived Tasseled Cap indices of wetness, greenness, and brightness, and the Normalized Difference Vegetation Index. Digitized maps provided ancillary data of elevation and soil geomorphology. Image enhancement was applied using Principal Component Analysis. A digital layer of roads together with georeferenced images was used to locate the study sites. A cluster analysis using the above data revealed two main groups of dense forests separated by spectral properties, altitude, and soil geomorphology. Virus was isolated more frequently from the forest type identified on flat flood plains of main rivers rather than the forest type found on the rolling hills of the study area. The spatial analysis suggests that mosquitoes carrying the enzootic viruses would reach 82-97% of the total land area by flying only 1-3 km from forests. We hypothesize that humans within that area are at risk of severe disease caused by enzootic ID VEE viruses. By contrast, equines could actually become naturally vaccinated, thus preventing the local emergence of epizootic IC VEE virus strains and protecting humans indirectly. PMID:12653150

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

    PubMed

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

    2014-06-01

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

  14. Reality of delusion: migrant perception of levels of living and opportunity in Venezuela, 1961-1971.

    PubMed

    Eastwood, D A

    1983-07-01

    To facilitate comparison of how well migrant perceptions may have accorded with reality and of the effects of that migration between 1961-71 may have had on relative regional development in Venezuela, a composite index based on state census data must be constructed by which the country's overall levels of living and social well being can be examined. The index constructed was loosely based on a range of variables suggested by Knox, but with the specific selected variables restricted by those data available in the Venezuelan censuses and other institutional reports. 20 variables were selected. Using these variables, a composite index of levels of living and social well being was constructed. The resultant index (S scores) for each state in 1971 appear in a table and a figure. These S scores demonstrated the relatively higher levels of living in the northern core area around Caracas, with S scores of over 200 in the Federal District and Miranda State. Ripple effects from the northern core also produced high scores in Aragua and Caraboba states. Secondary centers of relative prosperity were Zulia in the west and Bolivar in the east. The traditional Andean population centers in Tachira and Merida also scored positively. In contrast low S scores were found in a central belt of rural states. Lowest scores of all were in the states of Apure and Barinas, isolated on the southern margins of the central belt. Overall, the 1971 S scores decreased as distance from Caracas increased and clearly illustrated Venezuela's acute core/periphery imbalance. Despite the very substantial migration throughout the 1961-71 period, with only minor exceptions, the level of living pattern was essentially static, as a comparison of 1961 and 1971 reveals. Only the states of Bolivar (because of Guayanese industrial growth) and Nueva Esparata (because of its designation as a free port) showed significant 1961-71 improvement in state rankings; only Cojedes and Falcon (for unknown reasons) had significant decline. S scores clearly remained higher in the less rural states. In general, the majority of migration was toward those states with the higher S scores, and the high S scores correlated strongly and positively with net 1961-71 migration. The broad migrant perception of where potentially better overall conditions were likely to be found appeared to be largely accurate. When this overall picture was reduced to specific variables, the reality of migrant perception became less clear. Migrants tended to move not only to where wages were higher but also to where unemployment was higher. PMID:12313175

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

    SciTech Connect

    Karl, T.L.

    1982-01-01

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

  16. [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

  17. 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.

  18. Household social determinants of ascariasis and trichuriasis in North Central Venezuela.

    PubMed

    Quintero, Karen; Durán, Carmen; Duri, Deborah; Medina, Flor; Garcia, Josmar; Hidalgo, Glida; Nakal, Syndy; Echeverria-Ortega, Maria; Albano, Carlos; Incani, Renzo Nino; Cortez, Jackeline; Jiménez, Sara; Díaz, Marietta; Maldonado, Cecilio; Matute, Franklin; Rodriguez-Morales, Alfonso J

    2012-06-01

    Ascariasis and trichuriasis are highly prevalent parasitoses in tropical countries caused by Ascaris lumbricoides and Trichuris trichiura, respectively. Their prevalence is associated with poor sanitation and hygiene, among other biological and social factors. In this study, the associations of household social determinants with these soil-transmitted helminthiases in North Central Venezuela was assessed in the context of a National Study on Human Growth and Development (SENACREDH). This was a probabilistic, stratified, cross-sectional survey with a sample of 3388 individuals that weighted represents 4 675 433 inhabitants from the region. The prevalence of ascariasis and trichuriasis was 3.73% and 1.13%, respectively. In the univariate and multivariate analyses, these prevalences were significantly higher in those living in vulnerable houses [adjusted OR (AOR) = 1.479, 95% CI 1.428-1.532; and AOR = 10.519, 95% CI 9.971-11.097, respectively], houses located in rural areas (AOR = 2.067, 95% CI 2.035-2.101; and AOR = 1.918, 95% CI 1.868-1.970, respectively) and houses with a soil floor (AOR = 5.027, 95% CI 4.895-5.162; and AOR = 5.190, 95% CI 4.944-5.448, respectively), among other factors. People living in rural households with inappropriate building materials, insufficient basic public services such as water and waste disposal, and surrounding disease-prone environments are at higher risk of acquiring A. lumbricoides and T. trichiura infections. PMID:24029148

  19. 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

  20. 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

  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. Determinants of plasma pepsinogen levels in a population at high risk for stomach cancer in Venezuela.

    PubMed

    Kato, I; Miki, K; Muñoz, N; Vivas, J H; Lopez, G; Peraza, S; Carillo, E; Castro, D; Andrade, O; Sanchez, V

    1995-09-01

    Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre-cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG-I and PG-II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre-cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (< 2.0) was inversely associated with tobacco consumption. This may be due to a pharmacological effect of nicotine. The severe reduction of I/II ratio was also inversely associated with fresh fruit consumption. In addition, a decreased I/II ratio was positively associated with rice/pasta and arepas (tortilla made from corn) consumption and inversely associated with plantain consumption. Possible effects of vitamins and starchy food on the development of atrophic gastritis need to be studied further. PMID:7665219

  3. 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.

  4. Biostratigraphic sequence analysis of two Lower Miocene to Pliocene sections, Eastern Falcon, Northwestern Venezuela

    SciTech Connect

    Diaz De Gamero, M.L. ); Giffuni, G.; Castro Mora, M. )

    1993-02-01

    The eastern region of the Falcon Basin in northwestern Venezuela comprises a thick sedimentary sequence deposited from a deep marine bathyal to neritic environment, ranging in age from the Middle Eocene to the Pliocene. A detailed biostratigraphic study (foraminifera and calcareous nannoplankton) was carried out in two sedimentary sequences outcropping in Cumarebo and Piritu, adjacent areas of eastern Falcon, representing: platform, slope and basinal settings. The Cumarebo section is continuous in the studied interval, from the Middle Miocene to the Pliocene. The Piritu section is continuous from the Lower to the lower Upper Miocene, terminating unconformably beneath a thin interval of middle Pliocene platform sediments, indicating tectonism during the latest Miocene. The sequence stratigraphical interpretation was based on the biostratigraphic analysis of the benthic and planktonic fossils, facies distribution and sedimentological data. Systems tracts, sequence boundaries and maximum flooding surfaces from cycles TB2.4 to TB3.5 of the cycle chart were identified. In the Cumarebo section, the upper Middle and Upper Miocene is mostly composed of shales, with some turbiditic sands belonging to a LSW system tract. The upper most Miocene contains a thick carbonate buildup (HST), and it is overlain by a Pliocene section that shallows upward from upper slope to outer shelf depositional environments. In the basinal (Piritu) section, most of the sediments are deep-water shales belonging to a LSW system tract, with some turbiditic sands in the upper Lower Miocene. TST and HST sediments, with scattered carbonate buildups in the upper Middle Miocene were also identified.

  5. [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

  6. 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

  7. Levels, chemical fractionation, and solubility of lead in roadside soils of Caracas, Venezuela

    SciTech Connect

    Garcia-Miragaya, J.

    1984-08-01

    The author investigated the level, chemical fractions, and solubility of Pb in several roadside soils of heavily traveled areas of Caracas, Venezuela. Using 1 N HNO/sub 3/ extraction, he studied the levels of lead in 25 roadside soil samples and found a very high level of Pb (average enrichment factor 21.0), indicating a strong lead pollution of Caracas roadside soils by heavy traffic of motor vehicles. Lead accumulation was most localized in the top soil layer (0 to 5 cm) and in soils located within 1 m from the roadside. Chemical fractionation and solubility experiments on three surface soil samples containing high Pb levels showed that less than 0.7% Pb was in exchangeable form in these soils. The nonexchangeable Pb was found to be associated mainly with the organic and residual fractions in two of the three soils, and predominantly bound specifically to inorganic sites in the third soil. The amount occluded in iron oxides was low in the three studied soils. Solubility studies showed Pb to be less soluble at higher pH values and pointed to a direct relationship between total and exchangeable Pb content and solubility. In the soils studied Pb seems to be associated with several soil components by different sorption mechanisms acting concurrently, the predominant mechanism or mechanisms being stronger than normal ion exchange. This behavior was considered to have practical implications, such as low Pb mobility in the soil profile, as well as low availability to plant roots and soil biota.

  8. Influence of Mesozoic age structure on Miocene tectonic development in NE Anzoategui, Eastern Venezuela Basin

    SciTech Connect

    Sadler, P.; White, S.

    1996-08-01

    Structure within and surrounding the Quiamare-La Ceiba region, Eastern Venezuela Basin, is dominated by two major thrust fault systems. They were generated during Early-Middle Miocene time in response to oblique convergence of the Caribbean and South American plates. They are. respectively, the SE vergent NE-SW oriented Anaco fault system, and the SSE vergent ENE-WSW oriented Pirital fault system. The major structural feature associated with each fault system is a basement cored ramp anticline. New seismic data provides evidence that contributes to a better understanding of the sequence of tectonic development within and surrounding the Quiamare-La Ceiba region. Compressional structures in both the hanging wall and the footwall of the Pirital fault system appear to be inverted normal faults, that were previously active during Mesozoic time along the northern South America passive margin. A conjugate set of strike-slip faults is also present. They are oriented NNW-SSE, parallel to the Urica lineation, and SSW-NNE, respectively. A Mesozoic origin for these faults is suggested. Post-compressional relaxation during Plio-Pleistocene time resulted in the development of shallow, small scale normal faults. These normal faults appear to be localized by structural adjustments along the strike-slip fault sets. Existing oil and gas production within the Quiamare-La Ceiba region is from localized structural closures. Strike-slip faults dissect the prevailing structural grain, and may provide an additional hydrocarbon trapping mechanism.

  9. 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.

  10. 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.

  11. 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.

  12. [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.

  13. 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.

  14. 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.

  15. [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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

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

    PubMed

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

    2013-09-01

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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

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

  11. Modern climate forcing of terrigenous deposition in the tropics (Cariaco Basin, Venezuela)

    NASA Astrophysics Data System (ADS)

    Martinez, Nahysa C.; Murray, R. W.; Thunell, Robert C.; Peterson, Larry C.; Muller-Karger, Frank; Astor, Yrene; Varela, Ramon

    2007-12-01

    One approach to deciphering tropical Quaternary paleoclimate records has been to study the composition of terrigenous material in order to infer past changes in hydrologic and atmospheric conditions. Here we present the inorganic geochemistry (major and trace elements) of modern sediment traps and shelf sediments in the tropical Cariaco Basin, Venezuela, in order to characterize seasonal variation in deposition of the terrigenous component and to document linkages within the ocean-atmosphere-climate system. We show that variation in the chemistry of terrigenous input to the Basin is a sensitive monitor of the annual meridional migration of the Intertropical Convergence Zone (ITCZ). Additionally, seasonal terrigenous relative abundances are decoupled from terrigenous absolute fluxes, showing that abundances are not directly related to terrigenous delivery. Changes in mixing between local fluvial sediments, fluvial and/or eolian mafic material, and Saharan dust explains the observed seasonality. The modern seasonal variations are significantly smaller than those observed in the glacial-interglacial paleorecord, indicating that climate sensitivity at the two time scales is very different. A striking contrast in the behavior of Ti/Al between the longer glacial-interglacial time scale and the modern seasonality also suggests that long-term terrigenous deposition is not linked simply to 100-kyr shifting of the ITCZ. The modern data can be reconciled with the glacial-interglacial record by invoking generally drier conditions during glacial periods over tropical latitudes, combined with intermittent wet conditions caused by precessional forcing.

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

    PubMed

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

    2013-03-01

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

  13. 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

  14. [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

  15. Comparative study of the chemical composition of essential oils of five Tagetes species collected in Venezuela.

    PubMed

    Armas, Kaylin; Rojas, Janne; Rojas, Luis; Morales, Antonio

    2012-09-01

    The leaves and inflorescences of five species of Tagetes, family Asteraceae, were collected from different locations in Mérida state, Venezuela, and their essential oils analyzed by GC and GC/MS. Several differences were observed in the composition of these oils, mainly regarding the major components, which for T. caracasana were trans-ocimenone (64.3%) and cis-tagetone (13.7%), and for T. erecta, piperitone (35.9%) and terpinolene (22.2%). High amounts of trans-anethole (87.5%) and estragole (10.7%) were observed in T. filifolia, while T. subulata essential oil contained terpinolene (26.0%), piperitenone (13.1%) and limonene (10.8%). For T. patula, two different oil samples were analyzed, leaves (TPL) and inflorescences (TPI). The TPL oil showed terpinolene (20.9%) and piperitenone (14.0%) as main components, while the TPI sample was composed mainly of beta-caryophyllene (23.7%), terpinolene (15.6%) and cis-beta-ocimene (15.5%). PMID:23074915

  16. 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

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

    PubMed

    Contreras, Monica; Fernndez-Delgado, Milagro; Reyes, Nelson; Garca-Amado, Mara Alexandra; Rojas, Hctor; 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

  18. 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

  19. [Reef community structure at Falcón, Venezuela, before and after a mass mortality].

    PubMed

    Villamizar, E

    2000-12-01

    Morrocoy National Park used to be considered the most important continental coral reef of Venezuela. However, in January of 1996, there was a massive mortality of the benthic organisms for unknown reasons. The coral reef community was monitored since 1995, the year before the event, and yearly after that, until June 1999, by sampling linear transects and quadrats. A total of 26 hard corals were recorded in the study site (Playa Mero) in 1995 (36.56% cover), which already had some deterioration because 90.86% of the living coral cover was represented basically by four species, M. annularis with 51.36%, Colpophyllia natans with 18.22%, Agaricia agaricites with 11.58% and Porites porites with 9.70%. Three months after the event, living coral cover was only 4.84% and algae, particularly Dyctiota spp. covered most of the surface (81.89%). Benthic organisms suffered massive mortality over the whole depth gradient and in most park reefs. Even after three years the reef community shows highly perturbed conditions, with 85% of the total cover represented by the categories: dead coral, dead coral overgrowth by algae and sand. From the initial coral richness of the area (26 species) only nine species were observed although in very low cover (<1%), except for M. annularis and M. franksi, which presented lightly higher percentages. PMID:15266789

  20. [Breeding systems of the Paraguaná coastal plain plants, Venezuela. ].

    PubMed

    Lemus-Jiménez, Luis José; Ramírez, Nelson

    2005-01-01

    Breeding systems were evaluated for 51 plant species according to life form, pollination system, vegetation type, and phenology, in the coastal plain of Paraguaná Peninsula, Venezuela. Sexual systems were no associated to life form, pollination system, vegetation type, and phenology. The frequency distribution of sexual system was 82.3% hermaphroditism, 15.6% monoecy, and 1.9% dioecy. All sexual systems had a peak during the lowest rainfall. Genetic system distribution was 64.8% self-compatibility (including partially self-compatibility) and 35.2% self-incompatibility. Among self-compatible species, 45.1% were autogamous (19.6% not autogamous). The genetic systems were associated significantly to: (1) plant life form: self-compatible species tend to be herbaceous and self-incompatible plants tend to be woody species; (2) vegetation type: self-compatible species were predominant in the three vegetation types, but in the mangrove the frequency of self-compatible and self-incompatibles was similar; and (3) pollination system: most of the self-compatible species were polyphilous. Mating systems: xenogamous and autogamous species were associated only with plant life forms. Xenogamous plants were mostly woody species and autogamous plants were mostly herbaceous species. The high incidence of hermaphroditism, self-compatibility, and autogamy are related to herbaceous life form, polyphilous pollination system, and climatic conditions, together the insularity of the Paraguaná peninsula. PMID:17354451

  1. 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

  2. Infected dogs as a risk factor in the transmission of human Trypanosoma cruzi infection in western Venezuela.

    PubMed

    Crisante, Gladys; Rojas, Agustina; Teixeira, Marta M G; Añez, Nestor

    2006-07-01

    A total of 565 mongrel dogs from rural localities of Venezuela were examined by serological (DAT, IFAT and ELISA) and parasitological tests to address the status of Trypanosoma cruzi infection and to evaluate their role in the transmission of the infection to human population. The overall percentage of sero-positive infected dogs shown to be 67.6% (382/565):253 (61.7%) from 47 villages belonging to 8 states located at 4 different geographical regions of western Venezuela and 129 (33.5%) dogs from 48 households located in areas where Chagas disease is endemic. From 101 sampled dogs living in close proximity to 30 acute chagasic patients, 84% expressed specific anti-T. cruzi antibodies (Ab) with 12 of them (14%) showing blood circulating parasites (BCP). In these houses a high proportion of sero-positive people (20%) and frequent indoor infestation by triatomine-bugs (70%) was also recorded. The analysis revealed that from the 47 rural villages sampled during the study, 91.5% had the presence of T. cruzi sero-positive dogs, ranging from 62% positive localities at the states of Falcon and Cojedes to 100% in the other six studied Venezuelan states. This demonstrates that T. cruzi-infected dogs are found throughout all the geographical regions of western Venezuela irrespective of their ecological differences. Molecular typing of T. cruzi isolates from infected dogs using ribosomal and mini-exon gene markers, revealed the presence of both T. cruzi I and T. cruzi II lineages. The coincidence in the circulation of T. cruzi II in dog and human populations at the same locality and at the same time is reported and its significance is discussed. The combined serological, parasitological, epidemiological and molecular data is gathered here to call the attention on the presence of infected dogs as a risk factor in the maintenance of T. cruzi as a source for infection to humans. PMID:16797466

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. [Profile of antifungal susceptibility of species of Candida isolated from hemocultures in a university hospital, Maracaibo, Venezuela].

    PubMed

    Arcaya, Noris Margarita; Mesa, Luz Mila; Pineda, Maritza Rebeca; Beltrán-Luengo, Haydee; Milagros Calvo, Belinda

    2006-06-01

    The aim of this study was to determine the in vitro susceptibility of amphotericin B, fluconazole and itraconazole, to several Candida spp recovered from blood cultures on hospitalized patients at the University Hospital of Maracaibo, Venezuela. The determination of the antifungal susceptibility was carried out according to the microdilution method in broth developed by The European Committee for Antimicrobial Susceptibility Testing (EUCAST). The profile of susceptibility of the 74 isolates showed that all the studied species were susceptible to amphotericin B, and 97.2% and 89.2% to fluconazole and itraconazole, respectively. PMID:16854186

  8. 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.).

  9. 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

  10. 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.

  11. 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.

  12. Sedimentary and tectonic controls on oil occurrences in the traditional producing area, Barinas Subbasin, Western Venezuela

    SciTech Connect

    Daal, J.; Martinez, G.; Salas, J.

    1996-12-31

    A Stratigraphic and Tectonic model explains the oil-field locations in the Traditional Producing Area of the Barinas Subbasin, Western Venezuela. The database for the model includes a 585-km{sup 2} 3-D seismic survey, as well as petrophysical, lithologic and biostratigraphic data from Cretaceous and Tertiary sediments. A long-term relative sea level rise from Albian through Campanian (Cretaceous) time, coincident with passive-margin basin subsidence, resulted in onlap of marginal marine sands and marine-shelf limestones and shales over crystalline metamorphic rocks of the Guayana Shield Basement. Facies changes in the Cretaceous Aguardiente, Escandalosa, and Navay Formations are related mainly to eustatic sea level changes. A tectonic pulse deformed these sediments in Late Maastrichtian to Paleocene time. An erosional unconformity that developed atop this deformed Cretaceous section relates to tectonic uplift and not to sea-level change. Onlap of Middle Eocene marine transgressive Gobernador Fm. sands and Masparrito Fm. limestones over this unconformity was driven by increased tectonic subsidence. Accelerated tectonic subsidence drowned the Masparrito carbonate platform and led to deposition of a condensed section within the lower Paguey Formation; this condensed section marks a tectonic Maximum Flooding Surface not related to eustatic sea level change. After deposition of the Eocene Paguey, and just prior to deposition of the Oligo-Miocene Parangula Formation, a second tectonic event reactivated older faults and led to growth of structural traps for Cretaceous and Eocene reservoirs. Both tectonic and eustatic events have combined to control oil occurrence in the Barinas Subbasin.

  13. Sedimentary and tectonic controls on oil occurrences in the traditional producing area, Barinas Subbasin, Western Venezuela

    SciTech Connect

    Daal, J.; Martinez, G.; Salas, J. )

    1996-01-01

    A Stratigraphic and Tectonic model explains the oil-field locations in the Traditional Producing Area of the Barinas Subbasin, Western Venezuela. The database for the model includes a 585-km[sup 2] 3-D seismic survey, as well as petrophysical, lithologic and biostratigraphic data from Cretaceous and Tertiary sediments. A long-term relative sea level rise from Albian through Campanian (Cretaceous) time, coincident with passive-margin basin subsidence, resulted in onlap of marginal marine sands and marine-shelf limestones and shales over crystalline metamorphic rocks of the Guayana Shield Basement. Facies changes in the Cretaceous Aguardiente, Escandalosa, and Navay Formations are related mainly to eustatic sea level changes. A tectonic pulse deformed these sediments in Late Maastrichtian to Paleocene time. An erosional unconformity that developed atop this deformed Cretaceous section relates to tectonic uplift and not to sea-level change. Onlap of Middle Eocene marine transgressive Gobernador Fm. sands and Masparrito Fm. limestones over this unconformity was driven by increased tectonic subsidence. Accelerated tectonic subsidence drowned the Masparrito carbonate platform and led to deposition of a condensed section within the lower Paguey Formation; this condensed section marks a tectonic Maximum Flooding Surface not related to eustatic sea level change. After deposition of the Eocene Paguey, and just prior to deposition of the Oligo-Miocene Parangula Formation, a second tectonic event reactivated older faults and led to growth of structural traps for Cretaceous and Eocene reservoirs. Both tectonic and eustatic events have combined to control oil occurrence in the Barinas Subbasin.

  14. 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

  15. Study of the antibody response against Mycobacterium tuberculosis antigens in Warao Amerindian children in Venezuela.

    PubMed

    Araujo, Z; Waard, J H de; Fernández de Larrea, C; López, D; Fandiño, C; Maldonado, A; Hernández, E; Ocaña, Y; Ortega, R; Singh, M; Ottenhoff, Tom H M; Arend, S M; Convit, J

    2004-08-01

    This study was aimed at investigating alternate methods for serodiagnosis of tuberculosis (TB), which are needed because bacteriologic diagnosis of childhood TB is difficult. A selection of 80 serum and saliva samples were tested from Warao indigenous children under 15 years of age; 34 high TB suspects (28 positive and 6 negative for the tuberculin skin test, TST) and 46 healthy contact children (32 positive and 14 negative for the TST). Several enzyme-linked immunosorbent assay (ELISA) serological tests were developed to test for Mycobacterium tuberculosis-specific antibodies, including serum IgA, IgG, IgE, and secretory IgA (sIgA) in saliva against 3 specific antigens (PPD, HSP60, 38 kDa). Of these, 2 antigens, PPD and 38 kDa, showed significantly higher reactivity. The sensitivity and specificity of these tests for diagnosis remained limited, between 26.5% and 38.2%, and 77.4% and 97%, respectively. Of all the samples studied and combinations realized between all isotypes and antigens combined with 3 isotypes (anti-PPD IgG, IgE, and anti-38kDa sIgA) managed to detect the largest number of patients, showing an improved sensitivity level of 64.7%, although specificity levels dropped to 81.8%. These results were compared with the Omega diagnostics commercial kit results. The commercial kits showed significantly lower reactivity (sensitivity of 20% and 13.33% to Myco G and Complex Plus, respectively) and a specificity of 100%. This study shows that in indigenous populations of Venezuela, where invasive procedures cannot be used to select samples but evaluation with a chest X-ray for radiological studies is available, the combination of 3 specific isotypes may be a useful tool to increase diagnostic accuracy with pulmonary TB in this population, when used together with clinical and epidemiological criteria. PMID:15543417

  16. 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

  17. 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

  18. [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

  19. Spectral analysis of gravity anomalies and the architecture of tectonic wedging, NE Venezuela and Trinidad

    NASA Astrophysics Data System (ADS)

    Russo, R. M.; Speed, R. C.

    1994-06-01

    We have analyzed the spectral content of free air gravity anomalies in the Caribbean-South American plate boundary zone in order to determine better the near-surface (0-120 km) distribution of crustal and upper mantle elements which give rise to the unusual gravity field of this region. The plate boundary zone in northeastern Venezuela and Trinidad is the site of the world's sea level continental minimum of Bouguer gravity anomalies, yet the region is also one of mild topography (mean value 43 m, maximum 1200 m). We find the mean depths to interfaces of significant density contrast at a variety of depths for portions of the plate boundary zone. We interpret interfaces at 30-35 km and 32 km beneath the Guyana Shield and the Aves Ridge, respectively, to be the Moho. Other shallow interfaces (5-14 km) are most likely sediment cover-basement contacts in the Maturin foreland basin and southern Grenada Basin. Deeper interfaces (54-63 km) we associate with loaded and downwarped continental and oceanic South American lithosphere. The deepest boundaries, at depths of 89-120 km, may be related to detached or detaching oceanic lithosphere overridden by continental South America. We use our results to test the tectonic wedging model of the plate boundary zone recently published by Russo and Speed (1992). We find that the tectonic wedging model adequately describes many of the structural boundaries inferable from our analysis of gravity anomalies but that the model must be modified to include a thinner Guyana Shield crust.

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  1. [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

  2. 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.

  3. 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.

  4. Politics, class actors, and health sector reform in Brazil and Venezuela.

    PubMed

    Mahmood, Qamar; Muntaner, Carles

    2013-03-01

    Universal access to healthcare has assumed renewed importance in global health discourse, along with a focus on strengthening health systems. These developments are taking place in the backdrop of concerted efforts to advocate moving away from vertical, disease-based approaches to tackling health problems. While this approach to addressing public health problems is a step in the right direction, there is still insufficient emphasis on understanding the socio-political context of health systems. Reforms to strengthen health systems and achieve universal access to healthcare should be cognizant of the importance of the socio-political context, especially state-society relations. That context determines the nature and trajectory of reforms promoting universality or any pro-equity change. Brazil and Venezuela in recent years have made progress in developing healthcare systems that aim to achieve universal access. These achievements are noteworthy given that, historically, both countries had a long tradition of healthcare systems which were highly privatized and geared towards access to healthcare for a small segment of the population while the majority was excluded. These achievements are also remarkable since they took place in an era of neoliberalism when many states, even those with universally-based healthcare systems, were moving in the opposite direction. We analyze the socio-political context in each of these countries and look specifically at how the changing state-society relations resulted in health being constitutionally recognized as a social right. We describe the challenges that each faced in developing and implementing healthcare systems embracing universality. Our contention is that achieving the principle of universality in healthcare systems is less of a technical matter and more a political project. It involves opposition from the socially conservative elements in the society. Navigation to achieve this goal requires a political strategy that involves various actors within the state, the political society and civil society. PMID:23563780

  5. 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.

  6. Importance of the horse and financial impact of equine trypanosomiasis on cattle raising in Venezuela.

    PubMed

    Moreno, S Andrea; Concepción, Juan Luis; Nava, Mayerly; Molinari, Jesús

    2013-11-01

    In Venezuela, horses are indispensable for extensive cattle raising, and extensive cattle raising prevails in all regions. This determines the numerical relationship between horses and cattle (r = 0.93) to be relatively constant nationwide. At regional level, the average extension of cattle ranches varies greatly. However, in relation to the area covered by pastures, the numbers of horses (r = 0.95) and cattle (r = 0.93) are relatively uniform nationwide. Water buffalo occupy small fractions of the territory; therefore, their numbers are related to the area of pastures less strongly (r = 0.56). There is no information on the numerical relationship between the numbers of horses and water buffalo. In the Llanos region of the country, equine trypanosomiasis is responsible for a high mortality in horses, causing considerable financial losses to cattle ranches. So far, such losses have not been assessed. For this region, in 2008, it can be calculated that: (1) with no treatment, losses owing to horse mortality caused by this hemoparasitosis would have amounted to US$7,486,000; (2) the diagnosis and treatment of affected horses would have required an investment of US$805,000; and (3) in terms of horses saved, this investment would have resulted in benefit of US$6,232,000. Therefore, for every monetary unit invested, there would be a benefit 7.75 times greater, this ratio being applicable to any year and all regions of the country. It follows that the profitability of investing in the diagnosis and treatment of equine trypanosomiasis is guaranteed. PMID:23666515

  7. [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

  8. 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

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

    PubMed

    Urdaneta-Morales, Servio

    2014-01-01

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

  10. [Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008)].

    PubMed

    Vera, Vicente; Buitrago, Joaquín

    2012-06-01

    The second major nesting-site for green turtles in the Caribbean is Isla de Aves, an island protected as a wildlife refuge since 1972, located at 650km Northeast from La Guaira, Venezuela. In this island, the nesting population monitoring started in 1972 and in a more continuous way after 1978, when a Scientific-Naval Station was established and scientific observations started. Since historical data show that female captures had severely affected population levels in this island before 1978, this study aim to describe recent reproductive activities. For this, during the nesting seasons of 2001-2002 and 2005-2008, nesting females were measured and tagged using metal flipper tags. A total of 458 nights were sampled observing 5 154 female emergences, with a maximum of 53 in a single night. Non-observed emergences were calculated fitting the temporal distribution of observed emergences to a normal curve. Total emergences estimated varied from X=637.1+/-106.6 in 2001 to X =2 853+/-42.5 in 2008 (ANOVA F(6.5df)=60.37, p<0.0001). Internesting interval in the same season was estimated in X=10.71+/-1.32 days. Clutch frequency in a nesting season was calculated as X=1.71+/-1.6 times per female and season. Estimated number of nesting females per year varied from X=373+/-12.5 females in 2001 to X=l 669+/-56.1 females in 2008 (ANOVA F 55.6df)=89.42, p<0.0001); with a positive and significant trend (r=0.842, p=0.036). Results show that nesting females numbers are increasing. We suggest that the protection of the nesting area for more than 30 years, has contributed with this population increase. PMID:23894943

  11. Modern Climate Forcing of Terrigenous Deposition in the Tropics (Cariaco Basin, Venezuela)

    NASA Astrophysics Data System (ADS)

    Martinez, N. C.; Murray, R. W.; Thunell, R. C.; Peterson, L. C.; Muller-Karger, F.; Astor, Y.; Varela, R.

    2007-12-01

    One approach to deciphering tropical Quaternary paleoclimate records has been to study the composition of terrigenous material in order to infer past changes in hydrologic and atmospheric conditions. We have analyzed the inorganic geochemistry (major and trace elements) of modern sediment traps and shelf sediments in the Cariaco Basin, Venezuela, in order to characterize seasonal variation in deposition of the terrigenous component and to document linkages within the ocean-atmosphere-climate system. Our results show that variation in the chemistry of terrigenous input to the Basin is a sensitive monitor of the annual meridional migration of the Intertropical Convergence Zone (ITCZ). Additionally, terrigenous relative abundances are decoupled from terrigenous absolute fluxes, showing that abundances are not directly related to terrigenous delivery. Changes in mixing between local fluvial sediments, fluvial and/or eolian mafic material, and Saharan dust explains the observed seasonality. The modern seasonal variations are significantly smaller than those observed in the glacial-interglacial paleorecord, indicating that climate sensitivity at the two time scales is very different. Significant contrast in the behavior of Ti/Al between the longer glacial-interglacial time scale and the modern seasonality also suggests that long-term terrigenous deposition is not linked simply to 100-kyr shifting of the ITCZ. The modern data can be reconciled with the glacial-interglacial record by invoking generally drier conditions during glacial periods, combined with intermittent wet conditions caused by precessional forcing. Results from three additional years of time-series data as well as from the continental margin surrounding the basin, will also be discussed.

  12. 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

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

    PubMed

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

    2015-03-01

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

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

    PubMed

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

    2013-12-01

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

  15. Bearded saki feeding strategies on an island in Lago Guri, Venezuela.

    PubMed

    Norconk, Marilyn A; Conklin-Brittain, Nancy L

    2016-05-01

    Free-ranging bearded sakis (Chiropotes spp.) live in relatively large social groups (22-65+), inhabit very large home ranges (200-1,000 ha), and travel long distances (1.8 to >7 km) each day. While these characteristics would seem to reduce their ability to occupy habitat fragments, several studies suggest otherwise. The key to their success may lie in their dietary adaptations. Bearded sakis are strongly frugivorous, but are primarily seed eaters, and are able to ingest both young and mature fruit. We examined feeding activities of a group of bearded sakis over a 19-month period on a 180 ha island in Lago Guri, Venezuela. Given their feeding adaptations, we predicted that they would minimize peaks and troughs in plant species used for food, limit seasonal variation in the mechanical properties of foods ingested, and balance ingestion of energy-rich foods (e.g. lipids, nonstructural carbohydrates (TNC), and/or free simple sugars). We found that bearded sakis on Danto Manchado had a diverse (plant-based) diet, but two resources (Pradosia caracasana, Sapotaceae, and Oryctanthus alveolatus, Loranthaceae) provided a stable dietary base and were present in the diet almost every month. Second, we found little variation in the mechanical-resistance properties of fruits opened seasonally. Third, they alternated months ingesting foods with high TNC content and months of high lipid content. This may be an attempt to balance energy intake from available foods. Finally, their social propensity to split up into subgroups may predispose them to reduce group sizes to accommodate smaller available areas. We suggest that bearded sakis use both ecological and behavioral mechanisms to survive in smaller-than-typical areas. Longer-term studies (beyond a few generations) of bearded sakis in habitat fragments would allow us to estimate minimum survival area and identify critical resources or resource combinations. Am. J. Primatol. 78:507-522, 2016. © 2015 Wiley Periodicals, Inc. PMID:25809825

  16. [Clinical and epidemiological study of pediculosis capitis in schoolchildren from Coro, Venezuela].

    PubMed

    Cazorla, Dalmiro; Ruiz, Aixa; Acosta, María

    2007-12-01

    Between March-July 2003, a cross-sectional survey was conducted to investigate clinical and epidemiological data on Pediculus capitis infestation among 327 (175 males and 152 females) primary school age children of an urban sector of Coro city, from the semiarid region of Falcon state, north-western Venezuela. Children were evaluated ectoparasitologically by visual inspections of heads. Overall prevalence was 28.8% (94/327). Pediculosis capitis infestation rates were significantly higher in girls (84.0 vs. 15. 9%) [Odds Ratio (OR) = 11.4; p = 0.0001] and schoolchildren with hair length > 3 cm (OR = 11.0; p = 0.0001), nevertheless these were not significantly different among age groups, races, colour and type of hair (P > 0.05). Among the clinical findings, only head pruritus (18 vs 9.5%), especially at night (19.2% cases), and lymphadenopathy (7.3 vs. 5.5%) mostly located at the cervical region (14.9%), showed significantly higher percentages in infested children than in uninfested ones. Of interest was that lower socioeconomic levels (OR = 2.4; p = 0.02), high levels of overcrowding conditions (> or = 2 persons/bed: OR, 18.4; p = 0. 00001), sharing of combs and brushes (OR = 3.8; p = 0.0001), living with infested people (OR = 2.8; p = 0.0001), and showing previous infestation (OR = 9.5; p = 0.0001), also appeared to be significant factors associated with transmission and maintenance of pediculosis capitis among school children. PMID:18271390

  17. [Reproductive phenology of three vegetation types from a coastal plain of Paraguana Penninsula, Venezuela].

    PubMed

    Lemus-Jiménez, Luis José; Ramírez, Nelson

    2002-01-01

    Reproductive phenology of 51 plant species was evaluated according to life form and vegetation types in a coastal plain of the Paraguaná Peninsula, Estado Falcón, Venezuela. Plant species distribution according to three vegetation types (herbaceous littoral, herbaceous psamophil, and mangrove area) was determined. Life form frequency was different according to vegetation type. Herbaceous littoral and herbaceous psamophil vegetation were dominated by herbaceous species; woody species were mostly frequent in the mangrove vegetation. Phenological data revealed that 14 (27.5%) plant species flower and fruit year-round; 23 (45.1%) plant species flower and fruit at the beginning of the wet season; seven (13.7%) plant species flower at the end of wet season, and seven (13.7%) more flower at the beginning of the dry season. Flowsring and fruiting phenology showed similar frequency distribution during the year; reproductive phenology was independent of life forms. Flowering and fruiting peaks occurred during the rainy season and the beginning of the dry season for trees and perennial herbs, and from one to three months later for shrubs and annual herbs. The lowest proportion of flowering and fruiting occurred before rain increase for all life forms. Flowering and fruiting phenologies were similar for the three vegetation types evaluated: flowering peak occurred during the lowest value of precipitation, three to four months after precipitation peak, and fruiting peak occurred four months later from the precipitation peak. These results suggest that flowering and fruiting phenology were not affected by life form and vegetation types. The peaks of flowering and fruiting during the lowest values of precipitation may be considered as a slow and late response to the precipitation maximum, and to the proximity between maximum and minimum of precipitation. PMID:12945492

  18. 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.

  19. Luxación inveterada de la articulación de chopart. La importancia de reconocer las lesiones mediotarsianas.

    PubMed

    Sancho González, I; Menéndez García, M

    2016-01-01

                Las luxaciones de la articulación de Chopart (mediotarsiana) son relativamente raras pero potencialmente graves. Su baja prevalencia y la posible ausencia de signos radiológicos obvios no pueden justificar que pasen desapercibidas, puesto que el correcto diagnóstico y tratamiento de estas lesiones es necesario para obtener un buen resultado clínico.             Se presenta el caso de una luxación mediotarsiana en una mujer de 19 años de edad que fue diagnosticada a las ocho semanas de evolución. Se realizó una reducción abierta a través de un doble abordaje (medial y lateral) y una  estabilización de las articulaciones con agujas de Kirschner. Al año de la intervención, no se observó pérdida de reducción y la paciente no presentó dolor, pero si limitaciones funcionales para realizar deportes de carrera.             Además de describir el tratamiento de esta lesión tan particular, el presente trabajo pretende aumentar el nivel de sospecha para evitar errores diagnósticos como el ocurrido en nuestro caso.             Palabras clave. Fractura, Luxación. Mediotarsiana. Retraso diagnóstico. Reducción abierta. PMID:27125611

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  2. 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

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

    PubMed

    Labrador, Indira; Araque, María

    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 bla KPC-2, bla CTX-M-8, and bla TEM-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

  4. 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

  5. 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.

  6. [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

  7. [Fishery and biology of Rhinobatospercellens (Rajiformes: Rhinobatidae) caught by the artisanal fishery at La Pared beach, Venezuela].

    PubMed

    Tagliafico, Alejandro; Rago, Néstor; Rangel, Maria Salomé

    2013-03-01

    R. percellens is incidentally caught in Venezuela by the artisanal fishery using bottom gillnets. This species was classified by the IUCN as being "near threatened", and there is poor knowledge about its biology and fishery in Venezuela. For this reason, we analyzed the specimens caught by the artisanal fleet in playa La Pared, once a week, from January to December 2007. We determined total length, sex and maturity for each captured specimen. A total of 210 specimens were analyzed, 159 females and 51 males. The 81% of all specimens caught were adults, but within this group 27% were pregnant. The average size of sexual maturity was found between 51 and 52cm for females and males, respectively. Adult females were found all year round, and pregnant females in seven of the months sampled; highest numbers were found between February-March and September. The analyzed females had a total of 96 embryos with a size range between 2 and 19cm, with a maximum fertility of four embryos per litter. February and June-July showed the maximum breeding time, and considering the broad range of embryos sizes and the frequency of pregnant females along the different months, allow us to believe that they reproduce throughout the year. Fishing regulation including minimum catch size in relation to maturity length and release of pregnant females in water is recommended. PMID:23894969

  8. 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

  9. [Inventory of reptiles in 2 semi-arid zones from Northeastern of the Peninsula de Araya, Sucre State, Venezuela].

    PubMed

    Pablo Cornejo, E; Antulio Prieto, A

    2001-01-01

    The fauna of reptiles in two localities from Northeastern Peninsula de Araya (Guayacán and El Morahal), Sucre State, Venezuela, was evaluated. Both zones are characterized by a vegetation of thorny tropical mount type, and semiarid climate of scarce precipitations (less than 700 mm). Field trips were made between june 1997 and june 1998. The samples were collected both during day and night, with the aid of conventional accessories. The information was complemented with visual registrations and bibliography revision. A total of 21 species were captured and/or observed, distributed in 10 families belonging to 2 of the 3 orders present in Venezuela. The most important families from the point of view of the diversity of species, were the Gekkonidae (2.00 bits/species) for the lizards and the Colubridae (2.33 bits/species) among the snakes. It was also reported one species of tortoises and three of cinegetic interest, being Cnemidophorus lemniscatus, Ameiva bifrontata y Tropidurus hispidus the only species of constant presence during the study. PMID:11915444

  10. 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.

  11. Complete Genome Sequence of Streptomyces venezuelae ATCC 15439, Producer of the Methymycin/Pikromycin Family of Macrolide Antibiotics, Using PacBio Technology

    PubMed Central

    He, Jingxuan; Sundararajan, Anitha; Devitt, Nicholas P.; Schilkey, Faye D.; Ramaraj, Thiruvarangan

    2016-01-01

    Here, we report the complete genome sequence of Streptomyces venezuelae ATCC 15439, a producer of the methymycin/pikromycin family of macrolide antibiotics and a model host for natural product studies, obtained exclusively using PacBio sequencing technology. The 9.03-Mbp genome harbors 8,775 genes and 11 polyketide and nonribosomal peptide natural product gene clusters. PMID:27151802

  12. 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

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

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A. M.

    1996-06-01

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

  14. 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.

  15. 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.

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

  18. [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

  19. 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.

  20. 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.

  1. [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

  2. Neotectonic and paleoseismicity studies on the Urumaco Fault, northern Falcón Basin, northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A.; Bousquet, Jean-Claude; Rodríguez, José A.

    1999-07-01

    The northern Falcón Basin in northwestern Venezuela is affected by several small active faults, subordinated to the major right-lateral east-west-trending Oca-Ancón Fault System. A set of prominent NW-SE right-lateral faults — synthetic shears — such as the Urumaco, Rı´o Seco, Lagarto and La Soledad faults, stands out among those. The Urumaco Fault, located between the Lagarto and Mitare rivers (in the Urumaco Trough, west of Coro), presents a rather complex active fault trace that comprises two NW-SE fault segments linked by an ENE-WSW reverse echelon, all showing a restraining stepover geometry. Its western segment seems to continue to the north at sea. Conversely, the eastern one dies out on land and its northern tip ends in a transtensive horse-tail structure, that disrupts an Early Pleistocene conglomerate. This same unit is flexed and upheaved some 30 m at the restraining overlap. The kinematics and present stress tensor, the latest activity and the seismogenic potential of the eastern segment of the Urumaco Fault, have been assessed at a set of three river cuts of an ephemeral tributary stream of the Urumaco River, 3 km north of the Urumaco village, where the Urumaco Formation is truncated by a Late Pleistocene terrace ( 14C date of 20,700±950 yr BP at the base) of the Urumaco River. On the one hand, one of these outcrops features the Urumaco Fault affecting the Late Miocene Urumaco Formation, which comprises two prominent fault planes disposed as a wedge. The southwestern bounding plane juxtaposes two different sequences whereas the northeastern one does not, implying different slip behavior. In fact, the northeastern plane shows oblique-slip striations (29°N, normal-dextral), whereas the other one shows perfectly horizontal striations (right-lateral). On the other hand, both updip plane prolongations in the overlying alluvial unit are not so sharp, if the 17-cm throw of the erosive bottom of such terrace measured at the lowermost part of the southwestern plane is regarded as an artifact. However, a mudflat deposit within this unit is bent with a 14-cm throw right above the northeastern fault plane clearly affecting the underlying Miocene unit. The estimated total offset per event allows to infer the occurrence of two individual events of magnitude ranging between Ms 5.8 and 6.4 on this strand of the eastern segment of the Urumaco Fault in the last 20,000 yr.

  3. Surface Reservoir Characterization and Stratigraphic Studies Using Rock Magnetism and EPR in Venezuela: A Review

    NASA Astrophysics Data System (ADS)

    Aldana, M.; Diaz, M.; Costanzo-Alvarez, V.

    2007-05-01

    During the last years, the Paleomagnetic and Rock Magnetic Laboratory at the Simon Bolivar University has incorporated studies of rock magnetism and non conventional techniques in geophysics (as Electronic Paramagnetic Resonance or EPR) to solve diverse problems at the Venezuelan oil industry. Particularly, surface reservoir characterization and EPR-Magnetostratigraphic studies have been performed. At some Venezuelan oil fields (Guafita, La Victoria and Furrial) rock magnetic properties studies (e.g. Magnetic Susceptibility (MS)), extractable organic matter (EOM) and organic matter free radical concentration (OMFRC obtained via EPR) analysis have been applied trying to identified, at shallow levels, the "oil magnetic signature" of subjacent reservoirs. The results obtained in non consolidated samples from the first 1500 m of producers and non producers wells, show the existence of MS, EOM and OMFRC anomalies at shallow levels that are associated with an underlying reservoir and/or oil migration. Authigenic spherical aggregates of submicronic FE-rich magnetic crystals, observed by Scanning Electron Microscopy (SEM), are responsible for the detected MS anomalies. These studies allowed to establish a set of criteria (i.e. EPR, EOM and SEM) in order to link, with a minimum uncertainty, near-surface MS anomalies with the underlying reservoir. We have also explored the application of EPR, combined with petrographic, MS analysis, Qn and S-ratios, to characterize stratigraphic facies and identifying depositional environments at various sections in southwestern Venezuela. The different paramagnetic species that have been identified (e.g. manganese, free radicals and different Fe forms) together with the rock magnetic parameters, seem to give valuable information regarding the lithological characteristics of the studied sections. According to our results, as manganese content is related with the redox conditions, it can be used as a paleoenvironmental change index in stratigraphic columns with large lithological contrasts. For stratigraphic sections that present similar lithologies, the presence and concentration of distinct Fe species could be useful to characterize different depositional environments. The results obtained indicates that this kind of integrated analysis can be used as powerful tool for stratigraphic and environmental studies.

  4. 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 μm 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.

  5. Fraction of the CoMoS phases accessible to NO in Co-Mo hydrodesulfurization catalysts.

    PubMed

    Okamoto, Yasuaki; Kawano, Masatoshi; Kubota, Takeshi

    2003-05-01

    It is established by using Co-Mo model sulfide catalysts, XAFS and FTIR that Co atoms constituting CoMoS phases are not oxidized by NO adsorption and that only 55% of the CoMoS phases is susceptible to NO adsorption even at the maximum coordinative unsaturation attainable under usual HDS reaction conditions (623-673 K). PMID:12772915

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. The path to modernity: a personal testimony to the restructuring of the Department of Dermatology, Vargas Hospital, Caracas, Venezuela.

    PubMed

    Kerdel-Vegas, Francisco

    2014-01-01

    In the late 1950s and early1960s, there was a concerted effort to modernize teaching, training, and patient care in the Vargas Hospital of Caracas, Venezuela. The above included the development of research in the frame of postgraduate training. This effort was to be helped by USA funds and institutions but could only be achieved by the work of Venezuelans, sharing a vision of progress. Dermatology spearheaded this initiative, and the fruit of this was the exponential development of Venezuelan Dermatology and the creation of the National Institute of Dermatology on the grounds of the Vargas Hospital. The purpose of this contribution is to review these events that happened more than half a century ago from my own perspective. I sincerely hope that these lines could serve as an inspiration to the younger generations that toil today under less-than-favorable conditions. PMID:24559570

  11. [Population status of insects of Plecoptera order in Sierra Nevada National Park in Venezuela and its implications for conservation planning].

    PubMed

    Gamboa, Maribet

    2010-12-01

    Longitudinal distribution of Plecoptera species were examined along the Sierra Nevada National Park in the Andean region of Merida State, Venezuela. PNSN is one of the largest protected areas and consists of two major sub-basins. Quantitative samples were collected in 7 river tributaries along the PNSN from February to May of 2009, and a total of 135 individuals and 4 species of the genus Anacroneuria were collected. Only three rivers (Nuestra Señora, La Picón y Corcovada) found the presence of stoneflies, the principal component analysis show that the characterization of habitat, current velocity, dissolved oxygen and the absence of human disturbance sources of influence in a suitable habitat for populations. Stoneflies are endangered or have become extinct throughout much of its range due to human activities. Conservation plans must be implemented urgently, in order to avoid recreational areas and/or economic in vicinity thereof. PMID:21250479

  12. 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

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

    PubMed

    Longa, Aurora; Vizcaya, Luisa; Nieves, Beatriz; Bravo, Laura; Morier, Luis; Prez-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 Mrida, 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

  14. 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.

  15. [Clinical and epidemiological study of intestinal coccidioses in a rural population of a semiarid region from Falcon state, Venezuela].

    PubMed

    Cazorla, Dalmiro; Acosta, María Eleonora; Acosta, María Eugenia; Morales, Pedro

    2012-09-01

    Although intestinal coccidioses caused by Cryptosporidium sp., Cystoisospora belli and Cyclospora cayetanensis are parasitic diseases of major clinical importance in Public Health, several clinical and epidemiological aspects of these diseases still remain unknown in Falcon state, Venezuela. A cross-sectional survey was conducted between June and October 2011, to investigate clinical and epidemiological data in 157 people (X +/- S.D. = 21.28 +/- 17 years-old) from Sabaneta, Falcón state, Venezuela. Symptoms associated with intestinal coccidioses were determined by means of anamnesis and clinical examination. Direct smear and Kinyoun staining were used to perform the parasitological diagnosis. The overall prevalence of intestinal parasites was 61.78% (97/157) and Blastocystis sp. was the most prevalent intestinal parasite (56.68%). Coccidioses prevalence was 26.11% (41/157) and among these, cyclosporiasis was the most prevalent with 24.2%. There were no statistically significant differences in the prevalence between sexes or ages (X2 = 0.20; p = 0.70 and X2 = 10.06; p = 0.44, respectively). Diarrhea and epigastralgia were the most common clinical findings, and the only ones significantly associated with intestinal coccidioses (p < 0.05). In the light of these results, it can be concluded that hand washing (OR = 1.93), bathing (OR = 2.78), keeping domestic animals (OR = 10.1) and their feeding with waste (OR = 6.58), are potential risk factors that appeared to be significantly related to the transmission and endemic maintenance of intestinal coccidioses. PMID:23248971

  16. [Floristic and physiognomic characteristics of disturbed thorny xerophytic scrubland in Punta de Piedras, Miranda Municipality, Zulia State, Venezuela].

    PubMed

    Vera, Antonio; Martínez, Maritza; Ayala, Yin; Montes, Sadieth; González, Anderson

    2009-01-01

    We determined the floristic and physiognomic aspects of disturbed thorny xerophytic scrubland in Punta de Piedras, Miranda Municipality, Zulia State, Venezuela. Botanical sampling was done twice monthly (November 2005-June 2006), in both rainy and dry seasons, for a total of 16 samples. The sampling was done in 10 vegetation patches, in an average area of 718,2 +/- 706,24 m2, and adjacent graminoid floristic components were identified using three 400 m2 (20 x 20 m) plots, divided into 4 subplots (20 x 5 m2) and in these, were delimited 12 subplots (1 x 1 m2). In addition, human paths were carried out in order to identify other species plant. Thorny xerophytic scrubland showed human disturbances e.g. periodic fires, solid wastes, roads and human settlements and coastal semiarid thorny scrubland characteristics, similar to another Venezuelan localities. Forty-five species, in 22 families were identified, and the Poaceae (6), Mimosaceae (4), Boraginaceae (3), Cactaceae (3), Caesalpinaceae (3), Euphorbiaceae (3) and Fabaceae (3) presented the highest number of species. Human disturbances probably favor the appearance of vegetation patches and secondary grassland formations. In the last, Aristida venesuelae, Aristida pittieri y Portulaca pilosa showed the highest relative abundances and frequencies values with a summatory of 49,38% and 46,86%, respectively, while in the patches there were observed two layer: an herbaceous layer (less than 1 m high) as well as a bush-tree layer (2.63 +/- 1.37 m high), comprised mostly of Opuntia wentiana, Piptadenia flava and Jatropha gossypifolia with relative abundances of 32,82, 15,60 and 15,14%, respectively. The thorny xerophytic scrubland in Punta de Piedras presents a low number of species; however, the physiognomic characteristics are similar to other undisturbed thorny xerophytic scrublands in Venezuela. PMID:19637706

  17. 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.

  18. 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

  19. 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

  20. 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

  1. Hypsilara breweri n.sp. from Venezuela: description of new species with notes on the morphology and phylogenetic relationships of the genus (Coleoptera: Elmidae: Larainae).

    PubMed

    Ciampor, Fedor; Laššová, Kristína; Ciamporová-Zatovičová, Zuzana

    2013-01-01

    A new species of the genus Hypsilara Maier & Spangler, 2011, collected in the Eastern Venezuela, is described and illustrated. We provide habitus photographs, detail drawings of both male and female genitalia, and description of some morphological features, which were omitted in the description of the genus. Included are also remarks on the distribution and genetic distance of the Hypsilara species and possible relations to other South American Larainae. PMID:26097972

  2. 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

  3. Oncoplastic breast surgery: initial experience at the Centro Clinico de EstereotaxiaCECLINES, 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: 30512 g) in the OPS group versus 60.4 g (range: 20135 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 45 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 45 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 45 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 45 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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  5. [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

  6. Reconstruction of Sea/Lake-Level Changes in an Active Strike-Slip Basin (Gulf of Cariaco, NE Venezuela)

    NASA Astrophysics Data System (ADS)

    van Daele, M.; Audemard, F.; Beck, C.; de Batist, M.; van Welden, A.; Moernaut, J.; 2006 Shipboard Party, G.

    2008-05-01

    In January 2006, 76 high-resolution reflection seismic profiles were acquired in the Gulf of Cariaco, Northeast Venezuela. In the upper 100 m of sedimentary infill, 17 unconformity-bounded sequences were identified and mapped throughout the basin. Up to now, no core or borehole information is available to provide age constraints on these units. The sedimentary infill is cut by several faults, Riedel faults in the central part and the El Pilar fault (one of the main faults of the South American-Caribbean plate boundary) in the southern part of the gulf. The connection of the Gulf of Cariaco with the adjacent Cariaco Basin occurs at a present-day water depth of ~ 55 m. This implies that the gulf was disconnected from the world ocean and functioned as a lake during a large part of the last glacial. The main rivers entering the gulf drain the coastal mountain ranges and tend to form pronounced deltas at their inlet. During times when the gulf was a lake, periods with a dry climate resulted in dramatic lake-level lowstands and even complete desiccation/evaporation. The present-day depths of delta offlap breaks and the presence of lowstand/evaporite deposits can thus be used to estimate sea/lake level at the time of their formation. Detailed analysis of these stratigraphic sea/lake-level indicators allowed reconstructing the sea/lake-level history for the period encompassed by the 17 identified sequences. This sea/lake-level reconstruction also needed to be corrected for tectonic subsidence, affecting different parts of the gulf with different intensity. The reconstructed sea/lake-level curve of the Gulf of Cariaco was compared with the eustatic sea-level curve and with results of previous paleoclimate studies in Venezuela. The striking coherence between the eustatic curve and the amplitudes and absolute heights of successive reconstructed lowstands and highstands compelled us to tune our record to the eustatic curve in order to achieve a rough age estimate for our units. According to this age model, our seismic stratigraphy reaches back to MIS6, and the average sedimentation rate in the central parts of the gulf since MIS5e is 0.92 mm/y. Our data show that reconstructed lake levels in the Gulf of Cariaco, which represent a proxy for climate in NE- Venezuela, are very strongly coupled to the global stadials and interstadials of the last glacial period. Also the Younger Dryas is recognised in the sedimentary record of the Gulf of Cariaco as lowstand deposit resulting from an (almost) complete desiccation. Our data reveal that the stratigraphy of the Gulf of Cariaco holds a very accurate, complete and promising record of eustasy and climate change, at least since the penultimate glacial maximum. The quality of this record and the vicinity to the iconic Cariaco Basin make the Gulf of Cariaco an ideal target for future ocean drilling (or long coring).

  7. 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

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

    NASA Astrophysics Data System (ADS)

    Malav, Gustavo; SuRez, 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.

  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. 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

  12. Potential of vetiver (vetiveria zizanioides (L.) Nash) for phytoremediation of petroleum hydrocarbon-contaminated soils in Venezuela.

    PubMed

    Brandt, Regine; Merkl, Nicole; Schultze-Kraft, Rainer; Infante, Carmen; Broll, Gabriele

    2006-01-01

    Venezuela is one of the largest oil producers in the world. For the rehabilitation of oil-contaminated sites, phytoremediation represents a promising technology whereby plants are used to enhance biodegradation processes in soil. A greenhouse study was conducted to determine the tolerance of vetiver (Vetiveria zizanioides (L.) Nash) to a Venezuelan heavy crude oil in soil. Additionally, the plant's potential for stimulating the biodegradation processes of petroleum hydrocarbons was tested under the application of two fertilizer levels. In the presence of contaminants, biomass and plant height were significantly reduced. As for fertilization, the lower fertilizer level led to higher biomass production. The specific root surface area was reduced under the effects of petroleum. However, vetiver was found to tolerate crude-oil contamination in a concentration of 5% (w/w). Concerning total oil and grease content in soil, no significant decrease under the influence of vetiver was detected when compared to the unplanted control. Thus, there was no evidence of vetiver enhancing the biodegradation of crude oil in soil under the conditions of this trial. However, uses of vetiver grass in relation to petroleum-contaminated soils are promising for amelioration of slightly polluted sites, to allow other species to get established and for erosion control. PMID:17305302

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. [Availabilty of juveniles from natural sources of the oyster Pteria colymbus (Bivalvia: Mytilidae), in the Gulf of Cariaco, Venezuela].

    PubMed

    Marquez, B; Lodeiros, C; Jimenez, M; Himmelman, J H

    2000-12-01

    We examined the spat availability the oyster Pteria colymbus at 6-8 and 19-21 m depths for 15 months (March 1993-June 1994) in Turpialito, Golfo de Cariaco, Venezuela. Spats were trapped using artificial collectors (plastic filaments in bags, 30 x 60 mm), suspended from a long line. Each collector was replaced by a replica monthly to analyse abundance, shell dimension and mass of P. colymbus. Intraweekly, the temperature, salinity, oxygen and food availability (Chlorophyll a, total seston, organic and inorganic seston) were determinated. There is juvenile recruitment all year, suggesting continuous reproduction. Spat counts were higher at 6-8 m (generally 50-230 juveniles per collector) with peaks in August and December 1993 (April and June 93 at 19-21 m). The length-weigh mass relation was higher at 19-21 m, suggesting greater food availability because of lower organism density (including P. colymbus) and a greater water flux. Phytoplanktonic abundance and temperature were correlated (r2=0.38) with juvenile abundanc; this relationship and the association of juvenile abundance with higher temperature and Chlorophyll a levels, suggest that spat abundance was higher at the beginning of the water stratification period, when phytoplankton biomass is high. PMID:15266803

  20. Planktonic foraminiferal shell weight as a proxy for changing carbonate ion concentration in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Marshall, B. J.; McConnell, M. C.; Thunell, R.

    2010-12-01

    Ocean acidification, due to increased atmospheric CO2, has diverse implications for marine calcifiers. In this study we use biweekly sediment trap samples and concurrent hydrographic measurements collected between January 2003 and May 2007 in the Cariaco Basin, Venezuela (10°30’ N, 65°31 W) to assess the relationship between shell weight and carbonate ion concentration [CO32-] of two planktonic foraminiferal species, Globigerinoides ruber and Orbulina universa.. Measured salinity, pH, sea surface temperature (SST) and total alkalinity (TA) were used to estimate pCO2 and [CO32-]. Shells of both G. ruber (300-355 µm) and O. universa (425 - 700 µm) species were picked (10-20 per sample) and weighed. Globigerinoides ruber shell weights varied from 7 µg to 19 µg from 2003 to 2007, with an average value of 11 ± 0.86 µg while surface water [CO32-] ranged from ~225-290 µmol/kg and averaged 250 µmol/kg. The data reveal a strong positive linear relationship between foraminiferal shell weight and [CO32-] for G. ruber and we expect to observe a similar relationship for O. universa. The initial results suggest the use of foraminiferal shell weight as a proxy for past changes in ocean pH.

  1. 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.

  2. Arbuscular mycorrhizal fungi communities in a coral cay system (Morrocoy, Venezuela) and their relationships with environmental variables.

    PubMed

    Alguacil, M M; Torrecillas, E; Lozano, Z; Roldán, A

    2015-02-01

    Knowledge of the natural diversity of arbuscular mycorrhizal fungi (AMF) and understanding of their biogeographical patterns and what drive them might help to the maintenance and preservation of ecosystems under a changing environment. The objective of this study was to evaluate the contribution of different environmental factors to the determination of the composition of AMF assemblages in representative sites within the Morrocoy National Park (Venezuela). The community structure of the AMF under the canopy of Coccoloba uvifera was investigated in four cays (Borracho, Muerto, Peraza, and Paiclás) and one mainland location (Las Luisas). Based on partial sequences of the nuclear small subunit ribosomal DNA gene, the AM fungi in soil samples were divided into 31 operational taxonomic units, grouped in eight families. The canonical correspondence analysis showed that environmental factors related to insularity (the mean annual rainfall, the distance to the mainland coast, and the cay land area) and a soil property related to biological activity (the total carbohydrate content) were significantly related to the distribution of the AMF communities. PMID:25461083

  3. 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

  4. 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

  5. [Larvae-pupae parasitoids of Hylesia metabus Cramer (Lepidoptera: Saturniidae) in northeastern Venezuela: a case of natural biological control].

    PubMed

    Hernández, José V; Osborn, Frances; Herrera, Beatriz; Liendo-Barandiaran, Carmen V; Perozo, José; Velásquez, Diony

    2009-01-01

    The moth Hylesia metabus Cramer is considered a public health pest due to the release of urticating hairs by adult females during periodic invasions of towns and villages, producing dermatits in humans. We reported natural parasitism levels for this moth during six life cycles in two localities in northeastern Venezuela. Pupae were collected in the field and maintained under laboratory conditions (27 masculineC, 65% RH, 12L:12D photoperiod) until eclosion. In Mapire, parasitism increased from 33.0% to 91.1% in the three cycles studied, with the dipterans Belvosia spp. (Tachinidae) and Sarcodexia lambens Wiedemann (Sarcophagidae) and species from Ichneumonidae, Chalcidae, Perilampidae and Eulophidae being the most common. In Pedernales, parasitism decreased from 29.5% to 16.1%, and Belvosia spp. was the most abundant parasitoids, reaching parasitization levels between 70.7% and 96.2%. A significative parasitization by Neotheronia sp. (Hymenoptera: Ichneumonidae) (27.1%) occurred only in third life cycle. All natural enemies observed were koinobionts, larval-pupa parasitoids. The variations in the populations of H. metabus and its parasitoids in the areas studied are discussed. Belvosia spp. and S. lambens may have potential for use in integrated management program of H. metabus. PMID:19488514

  6. [Risk factors associated with the diagnosis of chronic Chagasic miocardiopathy in seropositive individuals from Barinas state, Venezuela].

    PubMed

    González, Beatriz; Silva, Martha; Al-Atrache, Yusra; Delgado, Yelitze; Serrano, José Luis; Doccimo, Angelina; Hernández, Huber; Verde, Juan; Morillo, Daniela; Marín, Jaime; Concepción, Juan Luis; Bonfante-Cabarcas, Rafael; Rodríguez-Bonfante, Claudina

    2014-06-01

    This study evaluates the risk factors associated with the diagnosis of chronic chagasic miocardiopathy (CChM) in 115 seropositive individuals to anti-Trypanosoma cruzi antibodies, in Barinas state, Venezuela. Serology was performed with ELISA and MABA; while the CChM diagnosis was established by electrocardiography and echocardiography. A complete clinical history including epidemiological, personal/familiar antecedents and psychobiological habits, plus socioeconomic, psychosocial and alimentary habits interviews were performed for each individual. Risk factors were determined through binary logistic regression. Results showed that 81 patients (70,4%; CI 95% = 66.4-74.4) had criteria for CChM, of which 74 (64.4%; IC 95% = 60.2-68.6) were in phase II; while 34 (29.6%; IC 95% = 25.5-33.5) were in phase I of the disease and 7 (6.1%; IC 95% = 4.0-8.2) in phase III. In a one year period, two patients in phase III died of heart failure. The diagnosis of CChM was associated with hunting practice, maternal history of cardiopathies, chewing chimó, medical history of hypertension and apex beat visible; it was negatively associated with canned and preserved foods ingest. In conclusion the CChM diagnosis has high frequency in seropositive individuals in Barinas and heart failure prevention must be based on an early medical attention and educative strategies in order to control risk factors. PMID:24974628

  7. Enhanced production of thrombinase by Streptomyces venezuelae: kinetic studies on growth and enzyme production of mutant strain.

    PubMed

    Naveena, Balakrishnan; Gopinath, Kannapan Panchamoorthy; Sakthiselvan, Punniavan; Partha, Nagarajan

    2012-05-01

    This investigation provides the enhanced production of thrombinase, a fibrinolytic enzyme using mutant Streptomyces venezuelae. Initially the mutagenesis of the marine isolate was done by UV and Ethyl methane sulfonate (EMS) and their mutational efficiencies were compared. The mutants were selected based on their high thrombinase activity and used for further studies. The mutant was found to be more halo and thermo tolerant comparing to wild. The effect of Dissolved oxygen level was also determined and the mutant offered the maximum specific growth rate as 0.2404 (h(-1)). The mutant showed high resistance to higher initial lactose concentration and the inhibition concentration was found to be 155.1mg/mL. The effect of S(0)/X(0) ratio on specific substrate consumption and production rate were also investigated. Both mutant and wild showed increase in specific substrate consumption and production rate at higher S(0)/X(0) ratio but the mutant showed better values than the wild strain. PMID:22401714

  8. 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.

  9. Epidemiology of Cyclospora cayetanensis infection in San Carlos Island, Venezuela: strong association between socio-economic status and infection.

    PubMed

    Chacín-Bonilla, Leonor; Barrios, Fernando; Sanchez, Yulaicy

    2007-10-01

    The epidemiology of Cyclospora cayetanensis is not well understood. Few community-based studies have addressed this issue. A study was conducted to determine the prevalence and risk factors for cyclosporiasis in San Carlos Island, Venezuela. A sample of 515 subjects (mean+/-SD: 21.4+/-17.8 years) was surveyed. For identification of the parasite, stools were examined with modified Ziehl-Neelsen carbolfuchsin staining of formalin-ether concentrates. Infections with Cyclospora (43 of 515, 8.3%) were common. There were differences in prevalence of the parasite among sectors of the community: 30 out of 43 (69.8%) cases of cyclosporiasis clustered in two sectors with extreme poverty. Living in these sectors versus the remainder, living in a hut or small residence versus a concrete or larger house, using an area of backyard rather than a toilet or latrine for defecation, and having contact with soil contaminated with human feces were factors strongly associated with the infection (P<0.01). Contact with soil contaminated with human feces might be an important mode of transmission, and poverty a predisposing factor, for the infection. PMID:17655898

  10. 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.

  11. 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

  12. Solution weathering rate and origin of karst landforms and caves in the quartzite of Auyan-tepui (Gran Sabana, Venezuela)

    NASA Astrophysics Data System (ADS)

    Piccini, Leonardo; Mecchia, Marco

    2009-05-01

    The paper reports the results of SiO 2 analyses in the Aonda Cave system, located on the Auyán-tepui, one of the widest table-mountains of the Gran Sabana (South Venezuela), characterised by karst landforms developed in siliceous rock. Chemical analyses underline the very low concentration of SiO 2 of the surface water. Percolation and cave drip waters have a SiO 2 concentration of about 1 mg/l. The mean silica load of the cave stream is 184 mg/s, mainly derived from surface solution removal in the allogenic recharge area. In the Aonda Cave system, the mean SiO 2 dissolved load is 40 mg/s, in part from surface solution (15%) and mainly from underground processes (85%). The low solubility of SiO 2 in slightly acidic water implies the importance of the time factor in the formation of cave systems. With the present dissolution rate, about 10 Ma would be necessary to form the known karst system. This estimation can be significant only if we assume that climate has been stable in the last few tens of millions of years. Furthermore, this age can be taken as a minimum estimate, while, according to the geomorphic evolution of the area, the origin of the Aonda Cave system could be reasonably dated back to at least 20-30 Ma, that is, to the Oligocene.

  13. 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.

  14. [Nitrogen, phosphorus and the C/N ratio in superficial sediments of the lagoon of Chacopata, Sucre, Venezuela].

    PubMed

    Fuentes Hernández, M V

    2000-12-01

    The basal behaviour and relationship with organic carbon (Corg) content and prevailing granulometric fractions, of organic nitrogen (Norg), total phosphorus (P-total) and C/N ratio in surface sediments of Chacopata lagoon, Sucre State, Venezuela, were studied. Concentrations and spatial gradients were determined in sixteen stations following a common method for marine sediments. Norg concentrations varied between 0.102 and 0.510% (x = 0.237%), total phosphorus between 0.012 and 0.094% (x = 0.058%) and C/N ratio between 9.27 and 44.47 (x = 20.53). The higher contents of Norg and total phosphorus are from sections with an abundance of mangroves, marine phanerogams, macroalgae, benthonic biomass and migratory birds shelters. The C/N ratio shows the typical values for carbonated sediments, indicating that the nitrogenous compounds are rapidly degraded and the organic matter presents itself as humic substances. This parameter was moderately associated with silt and clay, and showed antagonism with sand, whereas Norg and phosphorus showed no correlation with them. The organic contribution is purely autochthonous: no anthropogenous contributions were found. PMID:15266816

  15. 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.

  16. Tomato chlorotic leaf distortion virus, a new bipartite begomovirus infecting Solanum lycopersicum and Capsicum chinense in Venezuela.

    PubMed

    Zambrano, Karla; Geraud-Pouey, Francis; Chirinos, Doris; Romay, Gustavo; Marys, Edgloris

    2011-12-01

    Virus isolate T217L was obtained from a diseased tomato (Solanum lycopersicum) plant showing leaf deformation and chlorotic mottle symptoms near Maracaibo in the state of Zulia, Venezuela. Full-length DNA-A and DNA-B molecules of T217L were cloned and sequenced. The genome organization of T217L was identical to the bipartite genomes of other begomoviruses described from the Americas. Characteristic disease symptoms were reproduced in S. lycopersicum and Capsicum annum plants inoculated using the cloned viral DNA-A and DNA-B components, confirming disease aetiology. A sequence analysis of DNA-A showed that the T217L isolate has the highest sequence identity (84%) with sida yellow mosaic Yucatan virus (SiYMYuV), sida golden mosaic Honduras virus (SiGMHV) and bean dwarf mosaic virus (BDMV) isolates. This is less than the 89% identity in the DNA-A component that has been defined as the threshold value for the demarcation of species in the genus Begomovirus. The molecular data show that isolate T217L belongs to a novel tentative begomovirus species, for which the name tomato chlorotic leaf distortion virus is proposed. TCLDV was also detected in symptomatic C. chinense plants growing near the T217L-infected plant. PMID:21853328

  17. 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.

  18. Crustal structure in the Falcón Basin area, northwestern Venezuela, from seismic and gravimetric evidence

    NASA Astrophysics Data System (ADS)

    Bezada, Maximiliano J.; Schmitz, Michael; Jácome, María Inés; Rodríguez, Josmat; Audemard, Franck; Izarra, Carlos; The Bolivar Active Seismic Working Group

    2008-05-01

    The Falcón Basin in northwestern Venezuela has a complex geological history driven by the interactions between the South American and Caribbean plates. Igneous intrusive bodies that outcrop along the axis of the basin have been associated with crustal thinning, and gravity modeling has shown evidence for a significantly thinned crust beneath the basin. In this study, crustal scale seismic refraction/wide-angle reflection data derived from onshore/offshore active seismic experiments are interpreted and forward-modeled to generate a P-wave velocity model for a ˜450 km long profile. The final model shows thinning of the crust beneath the Falcón Basin where depth to Moho decreases to 27 km from a value of 40 km about 100 km to the south. A deeper reflected phase on the offshore section is interpreted to be derived from the downgoing Caribbean slab. Velocity values were converted to density and the resulting gravimetric response was shown to be consistent with the regional gravity anomaly. The crustal thinning proposed here supports a rift origin for the Falcón Basin.

  19. Epidemiology of the Cnidarian Physalia physalis stings attended at a health care center in beaches of Adicora, Venezuela.

    PubMed

    Cazorla-Perfetti, Dalmiro J; Loyo, Jesus; Lugo, Lusneida; Acosta, María E; Morales, Pedro; Haddad, Vidal; Rodriguez-Morales, Alfonso J

    2012-09-01

    Stings caused by jellyfish and jellyfish-like colonies are common all around the world, with serious manifestations and occasional deaths reported in some countries. Between December 2006 and 2007, epidemiological, clinical and treatment aspects of stings caused by the Portuguese man-of-war (Physalia physalis) in 59 patients consulting the ambulatory emergency in Adicora, Falcon State, Venezuela, were studied. Most of the stings occurred in males (59%) preschool and school-aged children (49%), visitors from other areas of the country (92%) during holidays when bathing or diving at the beach (97%). Injuries presented linear erythematous plaques at the point of contact with the animal, located in several anatomical sites. Most clinical manifestations observed were: intense burning pain, urticaria, erythema and inflammation (100%), as well dyspnea with laryngeal edema and fever (19%). Patients were treated with topical drugs, including antihistamine and antipyretic drugs, but also with systemic hydrocortisone. P. physalis stings in Adicora appeared to have a seasonal pattern, with systemic complications potentially life-threatening. Thus, epidemiological surveillance program is recommended, particularly in travelers. PMID:23067562

  20. 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

  1. [Clinical-epidemiological aspects of pityriasis versicolor (PV) in a fishing community of the semiarid region in Falcon State, Venezuela].

    PubMed

    Acosta Quintero, María Eugenia; Cazorla Perfetti, Dalmiro José

    2004-12-01

    Between August 2001 and May 2002, the prevalence and several epidemiological and clinical characteristics of pityriasis versicolor (PV) were studied in 902 individuals aged two months- 60 years, 426 females and 476 males, from a fishery community of Río Seco, a semiarid region in the state of Falcon, north-western Venezuela. The overall prevalence of the disease was 15.52% (140/902). The frequency of infection was higher in females (65.7% vs. 34.3%), children under one year of age and adolescents (27.9% y 32.1%, respectively), and dark skin (67.9%). The most commonly affected anatomical areas were the face (57.9%) and thorax (27.1%). The most important clinical features of the disease were: hypochromic (91.4%), multicentric (73.6%), pruritic (92.9%), fine scaled (80.7%) and irregularly shaped borders (91.4%). On the basis of these results, the possible risk factors on transmission dynamic and maintenance of the disease endemically is discussed. PMID:15709799

  2. Characterization of resistance to organophosphate, carbamate, and pyrethroid insecticides in field populations of Aedes aegypti from Venezuela.

    PubMed

    Mazzarri, M B; Georghiou, G P

    1995-09-01

    Resistance to the organophosphates (OP) temephos, malathion, and pirimiphos methyl, and the carbamate propoxur was found to be low (< 5-fold) in 3 Aedes aegypti populations collected from Falcon and Aragua states of Venezuela. Resistance to chlorpyrifos (OP), permethrin, and lambda-cyhalothrin (pyrethroids) was moderate (7-fold) in both populations. Mechanisms of resistance were investigated with the synergists piperonyl butoxide (mixed function oxidase inhibitor) and S, S, S-tributyl phosphorothioate (DEF, an esterase inhibitor). Nonspecific esterase and oxidase enzymes played a significant role in OP and carbamate resistance, respectively. Resistance to pyrethroid insecticides was not affected by DEF or piperonyl butoxide. This suggested the presence of another mechanism such as altered target site sensitivity (kdr). Biochemical tests showed significantly greater amounts of esterase activity in field strains, whereas insensitive acetylcholinesterase was not involved in either OP or carbamate resistance. These results must be considered in future control programs for Ae. aegypti, because OPs and pyrethroids are currently used in vector control in most countries of Central and South America. PMID:8551300

  3. [Enterobiasis among schoolchildren in a rural population from Estado Falcón, Venezuela, and its relation with socioeconomic level].

    PubMed

    Acosta, María; Cazorla, Dalmiro; Garvett, María

    2002-09-01

    Between may and july 2001, a survey was conducted in order to investigate the prevalence and symptoms of Enterobius vermicularis infection and its relationship with the socio-economic status and household crowding of 154 schoolchildren aged 6-12 years from a rural village in Falcon State, Venezuela. The Graham technique (perianal swabs with an adhesive cellulose tape) was used to perform the parasitological diagnosis. The overall prevalence was high (57.79%). There was no difference in the prevalence between sexes (X2 = 0.005; d.f. = 1) or ages (X2 = 3.63; d.f. = 6) (p > 0.05), suggesting similar risk conditions for all individuals. Anal pruritus was the most common clinical finding (53.9%). Other less frequent manifestations were the following: perianal lesions (34.8%) and vulvovaginitis (32.6%). Graffar analysis revealed that the majority of schoolchildren belong to the poorer socioeconomic strata: IV (55.9%) and V (29.87%), with overcrowded living conditions. The correlation between E. vermicularis infection and crowding rates was found to be statistically significant (r = 0.98; p < 0.001). In the light on these results, it can be concluded that poverty, overcrowding, anal pruritus, scarcity of water, inadequate personal and community hygiene play a relevant role on the transmission dynamics and endemic maintenance of enterobiasis among schoolchildren from Sabaneta. PMID:12229279

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. [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

  13. [Impact of artificial light on nesting in the leatherback turtle Dermochelys coriacea (Testudines: Dermochelyidae) at Cipara beach, Venezuela].

    PubMed

    Rondón Médicci, María; Buitrago, Joaquín; Mccoy, Michael

    2009-09-01

    The number of Leatherback turtle nests and their spatial distribution was compared between years with and without artificial light, and between dark and lighted beach segments, in Cipara Beach, Paria Peninsula, Venezuela. Residents were interviewed to identify their perceptions about the impact of artificial light on sea turtles. Mean volume of sand per meter of beach was larger at La Peña, Cipara and La Remate and smaller at Varadero (p<0.001), increasing from April to June and later decreasing until August (p<0.05). Mean percentage of gravel was higher at Varadero and La Peña, and lower at La Remate and Cipara. Most interviewed people said that artificial light does not affect sea turtles. Between 2000 and 2005, 1,217 leatherback landings and 1,056 nests were observed. Successful nests increased with the years (p=0.035) as well as total nest number (p=0.015). From 2000 through 2003 there were 743 landings, 661 nests and 374 clutches. During the two years with electric light (2004-2005), there were 474 landings, 395 nests and 232 clutches. Proportion of landings with nest building decreased significantly during the years with electric light (p=0.005), but nesting success did not vary (p=0.402). No significant difference was found between landings per beach meter in dark and lighted sectors (p=0.244), between nests built (p=0.379) and in the rate of successful nesting (p=0.516). Dark and lighted sectors did not differ in the proportion of landings with nest building (p=0.067) and success rate (p=0.833). PMID:19928451

  14. [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

  15. 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

  16. 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

  17. Detection and Characterization of Waterborne Gastroenteritis Viruses in Urban Sewage and Sewage-Polluted River Waters in Caracas, Venezuela

    PubMed Central

    Rodríguez-Díaz, J.; Querales, L.; Caraballo, L.; Vizzi, E.; Liprandi, F.; Takiff, H.; Betancourt, W. Q.

    2009-01-01

    The detection and molecular characterization of pathogenic human viruses in urban sewage have been used extensively to derive information on circulating viruses in given populations throughout the world. In this study, a similar approach was applied to provide an overview of the epidemiology of waterborne gastroenteritis viruses circulating in urban areas of Caracas, the capital city of Venezuela in South America. Dry season sampling was conducted in sewers and in a major river severely polluted with urban sewage discharges. Nested PCR was used for detection of human adenoviruses (HAds), while reverse transcription plus nested or seminested PCR was used for detection of enteroviruses (HuEVs), rotaviruses (HRVs), noroviruses (HuNoVs), and astroviruses (HAstVs). HRVs were fully characterized with genotype-specific primers for VP4 (genotype P), VP7 (genotype G), and the rotavirus nonstructural protein 4 (NSP4). HuNoVs and HAstVs were characterized by sequencing and phylogenetic analysis. The detection rates of all viruses were ≥50%, and all sampling events were positive for at least one of the pathogenic viruses studied. The predominant HRV types found were G1, P[8], P[4], and NSP4A and -B. Genogroup II of HuNoVs and HAstV type 8 were frequently detected in sewage and sewage-polluted river waters. This study reveals relevant epidemiological data on the distribution and persistence of human pathogenic viruses in sewage-polluted waters and addresses the potential health risks associated with transmission of these viruses through water-related environmental routes. PMID:19028907

  18. The southern margin of the Caribbean Plate in Venezuela: tectono-magmatic setting of the ophiolitic units and kinematic evolution

    NASA Astrophysics Data System (ADS)

    Giunta, Giuseppe; Beccaluva, Luigi; Coltorti, Massimo; Siena, Franca; Vaccaro, Carmela

    2002-07-01

    The southern Caribbean Plate margin in Venezuela consists of a W-E elongated deformed belt, composed of several tectonic units dismembered along the northern part of the South America continental Plate since the Late Cretaceous. The present review, based on petrology and tectono-magmatic significance of each unit, makes it possible to define the main geotectonic elements and to reconstruct the paleogeographic domains from Late Jurassic to Tertiary: (a) Mid-Ocean Ridge Basalt (MORB) proto-Caribbean oceanic basin (Loma de Hierro Unit); (b) oceanic plateau (Dutch and Venezuelan Islands basement); (c) rifted continental margin (Cordillera de La Costa and Caucagua-El Tinaco Units) with Within Plate Tholeiitic (WPTh) magmatism; (d) an intra-oceanic subduction zone represented by Island Arc Tholeiitic (IAT) magmatism (Villa de Cura and Dos Hermanas Units) of Early Cretaceous age; (e) an Early Cretaceous ocean-continent subduction trench filled by melange (Franja Costera); (f) a new intra-oceanic subduction zone, represented by the tonalitic arc magmatism of Late Cretaceous age (Dutch and Venezuelan Islands). Regional tectonic constraints and coherent kinematic reconstruction suggest an original "near-Mid America" location of the Jurassic-Cretaceous "proto-Caribbean" oceanic realm. From Early to Late Cretaceous one sub-continental subduction with melanges (Franja Costera Unit) and two main stages of intra-oceanic arc magmatism are recorded in the so-called "eo-Caribbean" phases. The first consists of generally metamorphosed and deformed volcano-plutonic sequences with IAT affinity (Villa de Cura and Dos Hermanas Units), probably in relation to a southeastward-dipping subduction. The second is mainly represented by generally unmetamorphosed tonalitic intrusives cutting the oceanic plateau in the Dutch and Venezuelan Islands, and related to the new intra-oceanic subduction with reverse lithospheric sinking. The latter probably marked the onset of the Aves/Lesser Antilles arc system in the Late Cretaceous.

  19. 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

  20. 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.

  1. Tidal currents in the Gulf of Paria (Venezuela) and their effects on the morphology of the bottom

    SciTech Connect

    Marcucci, E.; Soto, R.E.; Font, J.B.

    1996-12-01

    The Gulf of Paria, situated between the northeastern coast of Venezuela and the island of Trinidad, covers an area of about 7,200 square kilometers with shallow depths, normally inferior to 25 meters. The noticeable exception is the Gueiria trough with maximum depths exceeding 45 meters. The resulting tidal currents reach maximum velocities well above 1.5 m/s, capable of eroding the fine silty sediments if estuarine or deltaic origin present in the upper portions of the sub-bottom strata. The existing seismic and tectonic data of the Gulf of Paria suggest the presence of a fault pattern in an east-west direction, related to the dextral relative movement between the Caribbean and South American tectonic plates, so that the Gueiria trough origin has been related to this fault pattern. However, recent shallow geophysical data show absence of fault races in the upper sub-bottom strata of the Gueiria trough area, so that this must have been excavated by the tidal currents, which flow in alternating east-west directions with maximum surface velocities exceeding 1.4 m/s. The presence of strata of gravel controlled the erosion and resulted in the final morphology of the trough. This estuarine circulation pattern of the Gulf of Paria dictates particular requirements for pipeline laying, especially in the trough area and where the bottom is made of coarse gravely material, since the currents are strong, have alternating directions, but will probably not cause natural burial of the pipeline, because of the coarse sediment of the bottom.

  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. A multidisciplinary study of the complex Santa Barbara-Furrial oilfields, Northern Monagas area, Eastern Venezuela Basin

    SciTech Connect

    Bojas, B.; Salazar, A.; Robinson, A.; Meunier, M.; Oviedo, P.; Swallow, J.; Diamond, L. )

    1993-02-01

    A multidisciplinary study has been conducted on the giant oilfields located in the northern Monagas area of the eastern Venezuela basin. The oilfields occur in a lower tertiary and Cretaceous sequence which has been heavily tectonized as a consequence of recent transpression along the Caribbean south American plate boundary. This structurally complex area was initially mapped by using 3000 km. Of 2D seismic data. Experience has shown these data to be inadequate and a 150 sq Km 3D survey was acquired over the Santa Barbara area. These data have been interpreted and several new structural features have been identified. As a consequence of this work the structural model has been modified and applied throughout the area. The Cretaceous to late Oligocene sediments, including the Naricual formation which is the main producing horizon, has been studied systematically. These sediments were deposited initially in a fluvial environment which was gradually inundated by successive marine incursions. Approximately 7000 ft of core has been logged and the sedimentary facies and sequence boundaries recognized were then used to calibrate electric logs which allowed facies extrapolation across the whole area. The final parasequence analysis has provided a detailed and reliable reservoir correlation. Original pressure data and subsequent production histories, together with different known oil-water contacts implies separate producing areas. Complex fluid segregations, from condensates to heavy oil had also to be explained. The integration of the geophysical, geological, fluid and production data has allowed each discipline to refine their field models by removing conflicts between these data, thereby producing a better overall description of the reservoir.

  4. [Larval seasonality of the mosquito Anopheles aquasalis (Diptera: Culicidae) and other insects associated to its habitat in Sucre, Venezuela].

    PubMed

    Berti, Jesús; González, Julio; Navarro-Bueno, Edith; Zoppi, Evelin; Gordon, Elizabeth; Delgado, Laura

    2010-06-01

    Anopheles aquasalis Curry is considered the main vector of human malaria in Northern Venezuela. A longitudinal study was carried out in the coastal areas of the Paria Peninsula, Sucre state. The larval habitats of A. aquasalis were classified as: 1--Brackish mangrove, and 2--Freshwater herbaceous swamp. Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding sites over a one-year period, between January and December 1999. At each site, 30 samples of Anopheles larvae and aquatic insects were taken monthly. Simultaneously with mosquito larvae sampling, five selected variables of water were measured: conductivity, salinity, dissolved oxygen, temperature and pH. Seasonal and temporal variations of A. aquasalis larvae and aquatic insects were determined in the two larval habitats. For the entire study period, the abundance of larvae was higher in the mangrove. Correspondence analysis showed a strong relation between some chemical factors of water and larval abundance. The abundance of A. aquasalis larvae in both seasons, was positively correlated with water salinity, pH and conductivity, and negatively and with dissolved oxygen in the dry season. The presence of larvae was positively correlated with the presence of Avicenia germinans. In the mangrove there was a positive association between larvae abundance and Scirtidae family abundance and a negative correlation between larvae abundance and monthly precipitation (Spearman), as well as a significant negative correlation between Gerridae abundance and monthly precipitation. In the herbaceous swamp, there were not significant associations between A. aquasalis larvae abundance and abundance of others aquatic insects associated to habitat. PMID:20527475

  5. 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.

  6. [Gradients, stability and conservation status of fishes in the Andean mountain streams of the Orinoco versant, Venezuela].

    PubMed

    Rodríguez-Olarte, Douglas; Barrios Gómez, Margenny

    2014-09-01

    Most Andean mountain streams of the Orinoco Basin in Venezuela, had been suffering various disturbances. In spite of this, fish communities have been poorly evaluated in terms of spatial and temporal gradients. Thus, the generation of information about these communities is a priority, since it may support conservation of regional hydrobiological resources. For this, six sites were monthly evaluated in tributaries of upper Turbio River in Sierra de Portuguesa (770-1,305 msnm), during the dry season and the beginning of the rainy season (January-April 2012); we characterized stream dimensions, substrate and water physicochemical variables. Electrofishing was used to determine the number and abundance of fish species. The fish communities and their stability were evaluated by exploring the changes in richness and abundance, coefficients of variation, hierarchical classification and non-metrical multidimensional scaling analysis. The sites conservation status was estimated with a habitat integrity index. Our results showed that richness of the 12 species found varied accord- ing to the mountain elevation, the tributaries and the conservation status of the sites. Chaetostoma dorsale, Creagrutus taphorni and Chaetostoma milesi comprised 90.8% of the relative abundance, and maintained the first ranks during the study period. The communities had little spatio-temporal variation which was associated with a gradient signed principally by the amount of shadow, rocks and gravel cover, water temperature and conductivity. Stability was moderate but varied with elevation and according to site conservation status. The tributaries in upper Turbio River were found to be under severe impacts and their fishes were found impoverished and at risk. PMID:25412531

  7. A High-Resolution Oxygen Isotope Record for the Cariaco Basin, Venezuela Over the Last 6000 Years

    NASA Astrophysics Data System (ADS)

    Tedesco, K.; Thunell, R.; Tappa, E.

    2001-12-01

    Oxygen isotope records of three species of planktonic foraminifera (Globigerinoides ruber (pink), Globigerina bulloides and Neogloboquadrina dutertrei) from the Cariaco Basin, Venezuela were used to construct a high-resolution climate record for the Caribbean region for the mid to late Holocene. Our results indicate decreases in sea surface temperatures and/or increases in salinity in the basin at least four times over the last 4000 years (at ~3800-3200, 2800-2500, 2200-2000, and after 650 cal. yrs. B.P.). These events are coincident with high stands of Lake Titicaca, Bolivia/Peru suggesting a similar forcing mechanism. Paleoclimate records from the circum-Caribbean indicate arid conditions commenced in this region between about 3600-3200 cal. yrs. B.P.. This corresponds to a decrease in the δ 18O of G. ruber (pink) and decreases in the δ 18O differences between G. bulloides - G. ruber (pink) and N. dutertrei - G. ruber (pink). In addition, the deep dwelling planktonic foraminifera species Globorotalia crassaformis migrates into Cariaco Basin at about 3500 cal. yrs. B.P.. Taken together these data indicate colder sea surface temperatures and a shallow thermocline, possibly due to increased upwelling. Increased evaporation at this site would also result in higher G. ruber (pink) δ 18O values. Dry conditions in the circum-Caribbean tropics and wetter conditions in the Altiplano of Bolivia and Peru and the Amazon basin during the mid to late Holocene are consistent with a southward displacement of the Inter-Tropical Convergence Zone (ITCZ) resulting in decreased precipitation and increased trade wind intensity in the Cariaco Basin.

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

    PubMed

    Mora, Leonor; Garca, Ana; De Donato, Marcos; Urdaneta, Haide

    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

  9. Chromoblastomycosis in children and adolescents in the endemic area of the Falcón State, Venezuela.

    PubMed

    Pérez-Blanco, M; Hernández Valles, R; García-Humbría, L; Yegres, F

    2006-08-01

    The present paper describes 22 cases of chromoblastomycosis (CBM) caused by Cladophialophora carrionii in children and adolescents (2-19 years old). The patients were seen between 1992 and 2004 and all resided in a CBM endemic area in the semi-arid zone of the Falcón state, Venezuela. Twelve of the 22 patients (54.55%) had close relatives who also had CBM and 19 (86.36%) were male. Lesions consisted of erythematous papules with desquamation or squamous plaques (0.12-14.19 cm in diameter), located primarily on the upper limbs (77.27% of patients). Thirteen of the patients were treated with topical 5-fluorouracil (5-FU; 1% cream), seven with topical ajoene (0.5% gel) and two had electrodesiccation and/or fulguration. Two patients who did not respond to 5-FU were treated with oral itraconazole (100 mg/day for 1 month). Complete clinical and mycological remission was achieved in 17/20 (85%) of the patients treated with 5-FC, ajoene and electrodesiccation and/or fulguration. In addition, similar results were obtained with the two patients who received itraconazole therapy. These cases emphasize the importance of early diagnosis in difficult-to-treat mycotic diseases such as CBM. By early intervention we were able to employ topical treatment with a minimum of adverse effects to achieve a high percentage of favorable therapeutic responses. The patients were thus able to avoid the evolution of the chronic, deforming and incapacitation clinical manifestations associated with CBM. PMID:16882614

  10. [Pollination and pollinators in the vegetation of the coastal plain of Paraguaná, Falcón State, Venezuela].

    PubMed

    Lemus-Jiménez, Luis José; Ramírez, Nelson

    2003-01-01

    Pollination systems and plant-pollinator dynamics were studied for 51 plant species according to life form, vegetation type, and flowering phenology in the Paraguaná peninsula, Venezuela. A total of 43 species of floral visitors were recorded from which only 33 (76.7%) were effective pollinators and ten only visitors. Pollinator fauna consisted only of insects. Six pollinating agent classes were identified in the area of study. Pollinating bees were the most important class (35.1%), followed by butterflies (24.3%) and flies (13.5%). This trend was similar for the psamophilous and mangrove vegetation, but pollinating wasps were the third in importance in the littoral vegetation. Temporal distribution of pollinating agent classes showed a peak during the flowering peak, and during the lowest level of rainfall in the locality. Pollination systems were mostly polyphilous (62.7%) followed by monophilous (27.4%), and oligophilous species (7.8%). This trend was found to be similar for the different vegetation types and life forms. In a similar way, pollinator agents were mainly polytropic (60.4%), followed by monotropic (24.6%) and oligotropic species (14.8%). Plant species/pollinator species ratio was close to one for all vegetation types in the Paraguaná peninsula. Besides, the average number of pollinator species per plant species was 2.2, and the average number of plant species pollinated per insect species was 2.7. Plant species/pollinator species ratio and the average values of pollinator and plant species indicate a diffuse and symmetric relation between pollinator and plant species. These results are discussed in the context of the dynamics of pollination. PMID:14976781

  11. 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

  12. Molecular phylogenetics of the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae): evidence for Pliocene connections between mainland Venezuela and the island of Tobago.

    PubMed

    Jowers, Michael J; Lehtinen, Richard M; Downie, Roger J; Georgiadis, Andrew P; Murphy, John C

    2015-08-01

    The presence of Hyalinobatrachium orientale in Tobago and in northeastern Venezuela is puzzling as this species is unknown from the island of Trinidad, an island often hypothesized to be a stepping-stone for the mainland fauna to colonize Tobago. A period of extended isolation on Tobago could result in the Hyalinobatrachium population becoming distinct from the mainland H. orientale. Here, we use 12S and 16S rDNA gene fragments from nine H. orientale specimens from Tobago and the mainland to assess their relationship and taxonomy, as well as the tempo and mode of speciation. The results suggest H. orientale from Venezuela and Tobago are monophyletic and the two populations diverged about 3 million years ago. This estimate corresponds with the drier climate and lower sea levels of the Pliocene glaciation periods. We hypothesize that lower sea levels resulted in land-bridge formations connecting the mainland and Tobago, with a corridor of habitat allowing H. orientale to colonize Tobago to the west of Trinidad. PMID:24491102

  13. 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

  14. [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

  15. Miocene stratigraphy and depositional framework of northeastern Maracaibo Basin, Venezuela: Implications for reservoir heterogeneity prediction in tectonically-active settings

    NASA Astrophysics Data System (ADS)

    Guzman Espinal, Jose Ignacio

    1999-11-01

    Lateral and vertical changes in regime variables have a direct impact on the nature and distribution of macroscopic reservoir heterogeneity in tectonically-active basins. This relationship was tested in a clastic Miocene interval of the northeastern region of the Maracaibo Basin, Venezuela, by the integration and analysis of a comprehensive subsurface dataset. Four unconformity-bounded sequences record changes in accommodation, sediment supply, and sediment dispersal directions. These shifts were controlled by the uplift of the Sierra de Perija and by the marine connection between the Maracaibo and Falcon basins. The oldest sequence corresponds to the Early Miocene La Rosa Formation, which represents the episode of greatest increase in the regime ratio. After experiencing the maximum flooding event of the Neogene, accommodation space was filled by a mixed wave- and tide-influenced system of deltas and prograding shorelines that were fed from the west. Waterflooding in these reservoirs has been successful despite the compartmentalization and increased heterogeneity produced by rapid marine flooding of the deltaic pulses. Increased uplift and erosion of the sediment source areas shifted the regime ratio to supply dominated, causing a major fall in relative sea level and the development of a network of southwest- to northeast-oriented fluvially incised valleys. This event separates the La Rosa Formation from a younger sequence of highly heterogeneous tide-dominated estuarine deposits, overlain by tidal flats and tide-dominated deltaic sediments, that characterize the Lagunillas Inferior member of the Lagunillas Formation. The stratigraphic relationships and sedimentary fill of these incised valleys explain the complex nature of the LL-03/LL-05 reservoir boundary to the southeast of the study area. Continuing tectonic activity resulted in yet another significant drop in relative sea level, recorded by the abrupt onset of southeasterly flowing, mixed-load rivers, in the upper section of the Lagunillas Inferior Member. These deposits form the shelf-equivalent lowstand systems tract of the next younger sequence, which also includes the Laguna Member. A significant potential for targeting uncontacted and bypassed hydrocarbons exists in these reservoirs. Waterflooding has been relatively successful, but differences in directional permeability may be encountered across the fluvial entrenchment surfaces.

  16. 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

  17. 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.

  18. Sensitivity of Hydrologic Partitioning to Snowpack Dynamics, Como Creek, CO

    NASA Astrophysics Data System (ADS)

    Barnhart, T. B.; Molotch, N. P.; Harpold, A. A.; Knowles, J. F.; Anderson, S. P.

    2014-12-01

    Snowmelt is the primary source of surface water in the western United States and many other regions on Earth. Climate warming is forecast to impact the amount of precipitation that falls as snow and forms the mountain snowpack. Climate change induced alterations to snowpack translate to changes in snowpack magnitude, the timing of snowmelt, and changes in snowmelt rate. We ask how these perturbations may impact how snowmelt is partitioned between evapotranspiration (ET) and runoff (R) at Como Creek, a snowmelt dominated catchment on the Colorado Front Range. Como Creek is a 4.5 km2 headwater catchment spanning 2900-3560 m and is part of the Niwot Ridge Long Term Ecological Research Station and the Boulder Creek Critical Zone Observatory. We use observations of snow water equivalent (SWE), ET, and precipitation (P) from Niwot Ridge, CO, and discharge from Como Creek to explore relationships between snowpack dynamics and snowmelt partitioning. Measurements of ET are collected adjacent to Como Creek at the Niwot Ridge Ameriflux site and are assumed representative of the hydrologic fluxes in Como Creek. Analyses from point data show that years with higher peak SWE/P ratios partition proportionally more snowmelt to ET (pValue: 0.045). For example, water year (WY) 2005 has a peak SWE/P ratio of 0.49 and a growing season ET normalized by WY precipitation (ET/P) ratio of 0.48 while WY 2008 has a peak SWE/P ratio of 0.83 and an ET/P ratio of 0.82. Observations also show that years that experience later peak SWE (DOY=142) partition proportionally less snowmelt into ET (ET/P=0.42) compared to years that experience earlier peak SWE (DOY=86) and partition proportionally more snowmelt to ET (ET/P=0.56). Further point analyses also suggest that more rapid snowmelt results in proportionally less snowmelt partitioned to ET and more partitioned to runoff. To explore the underlying processes responsible for these relationships at the catchment scale we use the Regional Hydro-Ecologic Simulation System (RHESSys) to model how snowmelt is partitioned between ET and R under observed conditions and under a variety of climate change induced snowmelt timing, magnitude, and rate scenarios.

  19. 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

  20. Description of two new species of Rissoella Gray, 1847 (Mollusca, Gastropoda, Heterobranchia) from Venezuela, with a key to the Caribbean species known for the genus

    PubMed Central

    Caballer, Manuel; Ortea, Jesus; Narciso, Samuel

    2011-01-01

    Abstract Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensis sp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicola sp. n. Rissoella morrocoyensis sp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon and it lives on the leaves of the seagrass Thalassia testudinum Banks & König, 1805. Rissoella venezolanicola sp. n. has an angled preumbilical cord which extends to the columella delimiting a trapezoid, a hypobranchial gland marked by a yellow quaver-shaped ribbon and protoconch with fuchsia highlights. It lives on the brown alga Dictyota spp. The records of Rissoella in the Caribbean are revised and illustrations, a comparative table and a key to the Caribbean species known for the genus are provided. PMID:21976997

  1. [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

  2. Climate-correlated variations in seawater 187Os/ 188Os over the past 200,000 yr: Evidence from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Oxburgh, Rachel; Pierson-Wickmann, Anne-Catherine; Reisberg, Laurie; Hemming, Sidney

    2007-11-01

    A high resolution record of seawater osmium isotopic composition (35 samples over the past 191,000 yr) has been obtained from sediments from Ocean Drilling Program (ODP) Leg 165 Site 1002 in the Cariaco Basin, Venezuela. Strong correlations are observed between 187Os/ 188Os and both the local and global oxygen isotopic records, with less radiogenic values observed during glacial intervals. In conjunction with previous analyses of sediments from the East Pacific Rise, the Santa Barbara Basin, and the Japan Sea, the data demonstrate conclusively that there have been ocean-wide changes in seawater 187Os/ 188Os over the Pleistocene. Global seawater excursions to relatively unradiogenic 187Os/ 188Os, indicating decreased continental inputs, occur during cold intervals, times of increased aridity and increased ice cover of old (radiogenic) continental masses. The data thus indicate a direct climatic control on chemical weathering rates and/or composition of weathering products on a glacial-interglacial timescale.

  3. Revision of the plant bug genus Cylapocoris Carvalho (Hemiptera: Heteroptera: Miridae: Cylapinae), with descriptions of seven new species from Costa Rica, Brazil, Ecuador, and Venezuela.

    PubMed

    Wolski, Andrzej

    2013-01-01

    The plant bug genus Cylapocoris Carvalho, 1954 is revised. Seven new species: Cylapocoris costaricaensis sp. nov., C. cucullatus sp. nov., C. fulvus sp. nov., C. laevigatus sp. nov., C. marmoreus sp. nov., C. plectipennis sp. nov., and C. simplex sp. nov. are described from Costa Rica, Brazil, Ecuador, and Venezuela. The genus Adcylapocoris Carvalho, 1989 is synonymized with Cylapocoris. Five species: C. castaneus (Carvalho, 1989), C. funebris (Distant, 1883), C. pilosus Carvalho, 1954, C. sulinus Carvalho & Gomes 1971, and C. tiquiensis Carvalho, 1954 are redescribed. Illustrations of the male genitalia, color photographs of dorsal and lateral views of the adult of most species, scanning electron micrographs of selected structures of C. simplex, and keys to species of the genus Cylapocoris are provided. PMID:26120690

  4. Optical Response of the Atmosphere During the Caribbean Total Solar Eclipses of 26 February 1998 and of 3 February 1916 at Falcón state, Venezuela

    NASA Astrophysics Data System (ADS)

    Peñaloza-Murillo, Marcos A.

    2002-11-01

    An investigation of the optical response of the atmosphere before, during, and after the total solar eclipse of 26 February 1998 at the Caribbean Peninsula of Paraguaná (Falcón State) in Venezuela, was made by measuring photometrically the intensity of the sky brightness in three strategic directions: zenith, horizon anti-parallel or opposite the umbra path, and horizon perpendicular to this path. From these measurements, and by applying in an inverse way an empirical photometric model, very rough estimations of the extinction coefficient, and also of the average optical depth, were obtained in one of these particular directions. However based on meteorological measurements such as those of relative humidity and temperature, and applying a different model, a better estimation in the visual of the total global extinction coefficient of the sky (except the horizon), were made considering the contribution of each component: atmospheric aerosol, water vapour, ozone and Rayleigh scattering. It is shown that this global coefficient is mostly dependent upon aerosol extinction. In spite of the strong reduction of sky brightness photometrically observed during the totality, the results show that the sky was not dark. This is confirmed by the results obtained for the total global extinction coefficient. Additionally it is estimated that the total solar eclipse that took place also in Falcón State, Venezuela, at the beginning of the last century on 3 February 1916, was ~30% darker that the 1998 eclipse, and that atmospheric aerosol played a relevant and similar role in the scattering of sunlight during the totality as it was for 1998's. Visual observations made during each event, which show that at length only one or two bright stars could be seen in the sky, support the results obtained for both eclipses.

  5. 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

  6. 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

  7. [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

  8. 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.

  9. Seasonal variability in multi-elemental ratios and δ18O in planktonic foraminifera from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Wejnert, K. E.; Thunell, R.; Bizimis, M.; Astor, Y.

    2010-12-01

    Multi-elemental ratios (Mg/Ca, Mg/Li, Li/Ca, B/Ca, U/Ca, P/Ca, Cd/Ca, and Zn/Ca) of four planktonic foraminiferal species (Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) have been measure on a Thermo Element 2 inductively coupled plasma mass spectrometer (ICP-MS) and δ18O measurements have been taken on a GV ISOPRIME stable isotope ratio mass spectrometer. The material is from biweekly sediment trap samples collected in the Cariaco Basin, Venezuela (10o30’ N, 65o31’ W) between May 2003 and May 2004. The data are compared to local hydrography and water column chemistry to evaluate each proxy’s applicability in reconstructing past ocean conditions. The oxygen isotope results are consistent with known depth habitats for all five species. The surface dwelling G. ruber displays the lowest values of -0.84 and -1.76‰. G. sacculifer which lives in the upper 50m, displays slightly higher δ18O (-0.55 - -1.39‰) and the deeper dwelling O. universa and G. menardii have the highest δ18O, predominately ranging from 0.0 to -1.0‰. The G. ruber δ18O range equates to a temperature range of approximately 4.5 oC, which is equivalent to seasonal SST range (24.5-29 oC). Temperature estimates derived from species specific equations indicate that G. ruber most accurately tracks SST throughout the year. The temperature proxies, Mg/Ca (mmol/mol) and Mg/Li (mol/mmol), also reflect these different depth habitats (G. ruber: 4.1 - 6.9, 0.3 - 0.5; G. sacculifer: 2.9 - 4.3, 0.2 - 0.4; G. menardii: 1.9 - 4.3, 0.1 - 0.3) except that O. universa has a relatively high concentration of magnesium (7.1 - 13.1, 0.8 - 1.6). With these proxies, G. sacculifer most accurately reflects SST for both Mg/Ca and Mg/Li. For Li/Ca (µmol/mol) G. ruber has the highest ratios (13.2 - 18.5) and O. universa has the lowest (7.1 - 11.6). All of the species show an inverse relationship between temperature and Li/Ca with G. ruber most accurately recording SST. The pH proxy, B/Ca (µmol/mol), displays clear depth stratification with G. ruber having the highest B/Ca (246 - 360) and G. menardii and O. universa the lowest (102 - 230), consistent with a decrease in pH with depth. However, the other pH proxy, U/Ca shows no inter-species variation with all species having U/Ca values between 8 and 27 nmol/mol, which suggests that U incorporation is controlled by additional factors. All of the species display higher average values of the nutrient proxies P/Ca (mmol/mol), Cd/Ca (µmol/mol), and Zn/Ca (µmol/mol) during the winter upwelling than during non-upwelling, which is consistent with the nutrient distributions in the water column. None of the proxies show a significant relationship with measured phosphate concentrations; however this may be a result of uniformly low phosphate concentrations in the mixed layer.

  10. Valorisation of Como Historical Cadastral Maps Through Modern Web Geoservices

    NASA Astrophysics Data System (ADS)

    Brovelli, M. A.; Minghini, M.; Zamboni, G.

    2012-07-01

    Cartographic cultural heritage preserved in worldwide archives is often stored in the original paper version only, thus restricting both the chances of utilization and the range of possible users. The Web C.A.R.T.E. system addressed this issue with regard to the precious cadastral maps preserved at the State Archive of Como. Aim of the project was to improve the visibility and accessibility of this heritage using the latest free and open source tools for processing, cataloguing and web publishing the maps. The resulting architecture should therefore assist the State Archive of Como in managing its cartographic contents. After a pre-processing consisting of digitization and georeferencing steps, maps were provided with metadata, compiled according to the current Italian standards and managed through an ad hoc version of the GeoNetwork Opensource geocatalog software. A dedicated MapFish-based webGIS client, with an optimized version also for mobile platforms, was built for maps publication and 2D navigation. A module for 3D visualization of cadastral maps was finally developed using the NASA World Wind Virtual Globe. Thanks to a temporal slidebar, time was also included in the system producing a 4D Graphical User Interface. The overall architecture was totally built with free and open source software and allows a direct and intuitive consultation of historical maps. Besides the notable advantage of keeping original paper maps intact, the system greatly simplifies the work of the State Archive of Como common users and together widens the same range of users thanks to the modernization of map consultation tools.

  11. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

    ... 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide ... System-2 path 8. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission ...

  12. Area Handbook for Venezuela.

    ERIC Educational Resources Information Center

    Weil, Thomas E.; And Others

    This book provides a compact and objective exposition and analysis of the dominant social, political, and economic characteristics of Venezuelan society. Additionally, a major unit is devoted to national security. The study is designed to give readers both within and outside the United States government an understanding of the dynamics of the…

  13. 78 FR 36163 - Bitterroot National Forest, Darby Ranger District, Como Forest Health Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... FHP covers approximately 5,640 acres of national forest land between Lake Como and Lost Horse Roads... project area lies between Lake Como Road and Lost Horse Road, about three miles northwest of...

  14. 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.

  15. 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

  16. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    PubMed

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low concentrations for Chacopata and high concentration for La Restinga; the polyunsaturated fatty acids were between 4.66 and 35.55% with lower values for Chacopata and higher values for Chaguaramas samples. P. viridis is recommended for human being consumption, according to the high content of unsaturated fatty acids found for this species. PMID:21516644

  17. 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.; Matisāns, 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 μm3 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 μm3 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.

  18. Long term in-situ observations of biomass burning aerosol at a high altitude station in Venezuela - sources, impacts and inter annual variability

    NASA Astrophysics Data System (ADS)

    Hamburger, T.; Matisāns, M.; Tunved, P.; Ström, J.; Calderon, S.; Hoffmann, P.; Hochschild, G.; Gross, J.; Schmeissner, T.; Krejci, R.

    2013-05-01

    First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron aerosol volume, number concentrations of primary particles and particle absorption were observed. Orographic lifting and shallow convection leads to a distinct diurnal cycle at the station. It enables measurements within the lower free troposphere during night time and observations of boundary layer air masses during day time and at their transitional regions. The seasonal cycle is defined by a wet rainy season and a dry biomass burning season. The particle load of biomass burning aerosol is dominated by fires in the Venezuelan savannah. Increases of aerosol concentrations could not be linked to long-range transport of biomass burning plumes from the Amazon basin or Africa due to effective wet scavenging of particles. Highest particle concentrations were observed within boundary layer air masses during the dry season. Ambient sub-micron aerosol volume reached 1.4 ± 1.3 μm3 cm-3, heated (300 °C) particle number concentrations 510 ± 420 cm-3 and the absorption coefficient 0.91 ± 1.2 Mm-1. The respective concentrations were lowest within the lower free troposphere during the wet season and averaged at 0.19 ± 0.25 μm3 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.

  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. Association of Transferable Quinolone Resistance Determinant qnrB19 with Extended-Spectrum β-Lactamases in Salmonella Give and Salmonella Heidelberg in Venezuela

    PubMed Central

    González, Fanny

    2013-01-01

    Four nontyphoidal Salmonella strains with resistance to extended-spectrum cephalosporins and nonclassical quinolone resistance phenotype were studied. Two S. Give were isolated from pediatric patients with acute gastroenteritis, and two S. Heidelberg were recovered from raw chicken meat. Phenotypic characterization included antimicrobial susceptibility testing and detection of extended-spectrum β-lactamases (ESBLs) by the double-disc synergy method. The detection of quinolone resistance-determining regions (QRDR) of gyrA, gyrB, and gyrC genes, blaESBLs genes, and plasmid-mediated quinolone resistance (PMQR) determinants was carried out by molecular methods. Plasmid analysis included Southern blot and restriction patterns. Transferability of resistance genes was examined by transformation. blaTEM-1 + blaSHV-12 genes were detected in S. Give SG9611 and blaTEM-1 + blaCTX-M-2 in the other three strains: S. Give SG9811, S. Heidelberg SH7511, and SH7911. Regardless of origin and serovars, the qnrB19 gene was detected in the 4 strains studied. All determinants of resistance were localized in plasmids and successfully transferred by transformation. This study highlights the circulation of qnrB19 associated with blaTEM-1, blaSHV-12, and blaCTX-M-2 in S. Give and S. Heidelberg in Venezuela. The recognition of factors associated with increasing resistance and the study of the molecular mechanisms involved can lead to a more focused use of antimicrobial agents. PMID:24187555

  1. 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

  2. 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.

  3. Effects of land use change and seasonality of precipitation on soil nitrogen in a dry tropical forest area in the Western Llanos of Venezuela.

    PubMed

    González-Pedraza, Ana Francisca; Dezzeo, Nelda

    2014-01-01

    We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen. PMID:25610907

  4. [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

  5. Forest-savanna- morichal dynamics in relation to fire and human occupation in the southern Gran Sabana (SE Venezuela) during the last millennia

    NASA Astrophysics Data System (ADS)

    Montoya, Encarni; Rull, Valentí; Stansell, Nathan D.; Abbott, Mark B.; Nogué, Sandra; Bird, Broxton W.; Díaz, Wilmer A.

    2011-11-01

    The southern Gran Sabana (SE Venezuela) holds a particular type of neotropical savanna characterized by the local occurrence of morichales ( Mauritia palm swamps) , in a climate apparently more suitable for rain forests. We present a paleoecological analysis of the last millennia of Lake Chonita (4°39'N-61°0'W, 884 m elevation), based on biological and physico-chemical proxies. Savannas dominated the region during the last millennia, but a significant vegetation replacement occurred in recent times. The site was covered by a treeless savanna with nearby rainforests from 3640 to 2180 cal yr BP. Water levels were higher than today until about 2800 cal yr BP. Forests retreated since about 2180 cal yr BP onwards, likely influenced by a higher fire incidence that facilitated a dramatic expansion of morichales. The simultaneous appearance of charcoal particles and Mauritia pollen around 2000 cal yr BP supports the potential pyrophilous nature of this palm and the importance of fire for its recent expansion. The whole picture suggests human settlements similar to today - in which fire is an essential element - since around 2000 yr ago. Therefore, present-day southern Gran Sabana landscapes seem to have been the result of the synergy between biogeographical, climatic and anthropogenic factors, mostly fire.

  6. 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.

  7. Analysis of the El Niño/La Niña-Southern Oscillation variability and malaria in the Estado Sucre, Venezuela.

    PubMed

    Delgado-Petrocelli, Laura; Córdova, Karenia; Camardiel, Alberto; Aguilar, Víctor H; Hernández, Denise; Ramos, Santiago

    2012-09-01

    The last decade has seen an unprecedented, worldwide acceleration of environmental and climate changes. These processes impact the dynamics of natural systems, which include components associated with human communities such as vector-borne diseases. The dynamics of environmental and climate variables, altered by global change as reported by the Intergovernmental Panel on Climate Change, affect the distribution of many tropical diseases. Complex systems, e.g. the El Niño/La Niña-Southern Oscillation (ENSO), in which environmental variables operate synergistically, can provoke the reemergence and emergence of vector-borne diseases at new sites. This research investigated the influence of ENSO events on malaria incidence by determining the relationship between climate variations, expressed as warm, cold and neutral phases, and their relation to the number of malaria cases in some north-eastern municipalities of Venezuela (Estado Sucre) during the period 1990-2000. Significant differences in malaria incidence were found, particularly in the La Niña ENSO phases (cold) of moderate intensity. These findings should be taken into account for surveillance and control in the future as they shed light on important indicators that can lead to reduced vulnerability to malaria. PMID:23032283

  8. 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.

  9. 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

  10. 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

  11. Climatically sensitive eolian and hemipelagic deposition in the Cariaco Basin, Venezuela, over the past 578,000 years: Results from Al/Ti and K/Al

    NASA Astrophysics Data System (ADS)

    Yarincik, K. M.; Murray, R. W.; Peterson, L. C.

    2000-04-01

    Al/Ti and K/Al ratios in bulk sediment are used to interpret wind-blown and hemipelagic sources of deposition to a 578 kyr record in the Cariaco Basin, Venezuela (Ocean Drilling Program site 1002). Graphical and cross-spectral analyses indicate that these ratios vary extremely closely with planktonic foraminiferal δ18O, with both ratios being significantly higher during interglacials and lower during glacials. K/Al indicates that during glacials the lower sea level that results in relative basin isolation increases the relative proportion of kaolinite derived from local rivers draining the relatively humid Venezuelan margin. Al/Ti decreases during glacials, suggesting greater proportions of eolian rutile sourced from the northern Sahara (due to increased wind strength and/or aridity). This interpretation is consistent with previous studies of the chemistry and mineralogy of Saharan-derived eolian matter in the Caribbean and with a mass balance determining the effect of changes in eolian rutile accumulation on the bulk sedimentary Al/Ti ratio.

  12. 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.

  13. 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.

  14. 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.

  15. 24-locus MIRU-VNTR genotyping is a useful tool to study the molecular epidemiology of tuberculosis among Warao Amerindians in Venezuela.

    PubMed

    Maes, Mailis; Kremer, Kristin; van Soolingen, Dick; Takiff, Howard; de Waard, Jacobus H

    2008-09-01

    While the gold standard for molecular epidemiological studies on tuberculosis is changing towards MIRU-VNTR typing because this technique generates easily analyzed numerical results, it is less labor intensive and has a discriminative power comparable to that of IS6110-based RFLP, especially when 24 loci are analyzed; more extensive and representative validation studies are needed to confirm this. In this study we genotyped 41 Mycobacterium tuberculosis isolates, about 40% of the total case load of the study year, from the Warao people, an indigenous population who live in a geographically isolated area in Venezuela and have a high TB incidence of 450/100,000. IS6110-based RFLP analysis on these isolates indicates that 78% of the strains are in clusters, suggesting a very high transmission rate. We show that both the 15-locus MIRU-VNTR combined with spoligotyping, as well as the 24-locus MIRU-VNTR typing have sufficient discrimination power (an HGI of 0.93 and 0.95, respectively) to replace IS6110-based RFLP (HGI=0.93) and thus are useful tools to study the molecular epidemiology of tuberculosis in this high TB incidence population. PMID:18514577

  16. 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.

  17. Light and desiccation responses of some Hymenophyllaceae (filmy ferns) from Trinidad, Venezuela and New Zealand: poikilohydry in a light-limited but low evaporation ecological niche

    PubMed Central

    Proctor, Michael C. F.

    2012-01-01

    Background and Aims Hymenophyllaceae (filmy ferns) are typically plants of shady, constantly moist habitats. They attain greatest species diversity and biomass in humid tropical montane forests and temperate hyperoceanic climates. This paper presents ecophysiological data bearing on their worldwide ecological niche space and its limits. Methods Chlorophyll fluorescence was used to monitor recovery in desiccation experiments, and for measurements of 95 % saturating irradiance [photosynthetic photon flux density (PPFD95 %)] of photosynthetic electron flow and other parameters, in the New Zealand Hymenophyllum sanguinolentum, and three species each of Hymenophyllum and Trichomanes from forests in Trinidad and Venezuela. Key Results Hymenophyllum sanguinolentum was comparable in desiccation tolerance and light responses with the European species. The more common species in the two tropical forests showed PPFD95 % >100 µmol m−2 s−1, and withstood moderate desiccation (–40 MPa) for several days. The four most shade-adapted species had PPFD95 % ≤51 µmol m−2 s−1, and were sensitive to even mild and brief desiccation (–22 MPa for 3 d). Conclusions Light and desiccation responses of filmy ferns can be seen as an integrated package. At low light and windspeed in humid forests, net radiation and saturation deficit are low, and diffusion resistance high. Water loss is slow and can be supported by modest conduction from the sub-stratum. With higher irradiance, selection pressure for desiccation tolerance increases progressively. With low light and high humidity, the filmy fern pattern of adaptation is probably optimal, and the vascular plant leaf with mesophyll and stomata offers no advantage in light capture, water economy or CO2 uptake. Trade-offs between light adaptation and desiccation tolerance, and between stem conduction and water absorption through the leaf surface, underlie adaptive radiation and niche differentiation of species within the family. Hymenophyllaceae are a rare example of an evolutionary shift of adaptive strategy from typical vascular plant adaptation to the poikilohydry most typical of bryophytes. PMID:22334496

  18. [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

  19. 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

  20. 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 ) and two co-crystal structures with bound endogenous substrates YC-17 (resolution 2.35 ) or narbomycin (resolution 1.7 ). 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

  1. 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.

  2. Export of dissolved organic and inorganic nitrogen and total suspended sediments across an urbanization gradient in four tropical rivers of Venezuela

    NASA Astrophysics Data System (ADS)

    Rasse, R. J.; Perez, T.; Giuliante, A.; Donoso, L.

    2012-12-01

    We determined monthly concentrations of total dissolved nitrogen (TDN), dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON) and total suspended sediment (TSS) from 4 Venezuelan watersheds from August 2008 to September 2009. Three of these watersheds are mountainous rivers (Tuy, Neverí and Manzanares) and one is flat (Unare River). The three mountainous rivers vary in the degree of urbanization, with the Tuy hosting Caracas, the largest city in Venezuela. We found an order of magnitude larger TDN concentrations in the Tuy, which is impacted mainly by untreated point sources derived from Caracas metropolitan area. The largest TSS values were observed in the three mountainous rivers (Tuy, Neveri and Manzanares). TDN and TSS concentrations varied seasonally with larger TDN and lower TSS values during the dry season for all rivers. Most of the annual discharge of TDN (92%) and TSS (97%) takes place during the rainy season. Our results suggest that urbanization is the largest contributor affecting the composition and magnitude of TDN, whereas orography and local hydrology control the discharge of both TSS and TDN. We calculated the Water Pollution Level (WPL) for DIN and DON to determine the degree of contamination of these species in the evaluated watersheds. WPL values less than 1 indicate that there is in average enough dilution capacity in the river to assimilate the pollutant, whereas WPL larger than 1 indicate that the pollution assimilation capacity has been surpassed. All our evaluated rivers but the Tuy River show WPL-DIN and WPL-DON values between 0.1 and 0.96. The Tuy River had a WPL-DIN=6.3 and WPL-DON= 7.5. We attribute the Tuy River's large DIN and DON contamination to untreated urban point sources due to the strong correlation between population density and DIN and DON concentration from the evaluated watersheds. Our results suggest that urgent water treatment is required for this watershed to diminish the impact in coastal ecosystems.

  3. 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

  4. 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

  5. Atmospheric deposition of SO 4-S and (NH 4+NO 3)-N at two rural sites in the Western Maracaibo Lake Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Morales, Jose Agustin; Bifano, Claudio; Escalona, Andres

    Rain samples were collected by events from November 1988 to November 1989 at La Esperanza and Catatumbo sites. Dry deposition was collected only at La Esperanza. Volume weighted average pH values of the rainfall samples were between 4.23 and 4.64, individual samples reaching as low as pH 3.0. An excess of sulfate greater than 96% was obtained at both sites. The wet deposition of hydronium and sulfate showed the same seasonal cycle. The highest inputs were obtained in April during the early rainy season, and November which is the second peak rainfall period. The amounts of (NH 4+NO 3)-N ha -1 yr -1 added by wet deposition ranged from 5.2 kg at La Esperanza to 11.4 kg at Catatumbo (ammonium accounts for about 67% of these amounts), and the corresponding amounts of SO 4-S deposited ranged from 10.5 to 12.5 kg, respectively. These amounts of S and N annually deposited by precipitation are substantially higher than those found in eastern Venezuelan sites, and slightly lower than the values reported for rural areas of Europe and North America. In La Esperanza it was estimated that wet deposition accounts for about 93% of the inorganic-N and for about 80% of the SO 4-S annually added by dry and wet deposition. It is envisaged that in Lake Maracaibo Basin large argricultural and uncultivated land areas downwind of the El Tablazo Petrochemical Complex, Cardon-Amuay and, probably, the Aruba-Curacao refineries and urban Maracaibo might already be affected by anthropogenic air pollution as evidenced by the higher level of H +, SO -24, NO -3 and NH +4 wet deposition found at the La Esperanza and Catatumbo sites in comparison with other rural sites in Venezuela.

  6. Fluvial geochemistry of the eastern slope of the northeastern Andes and its foredeep in the drainage of the Orinoco in Colombia and Venezuela

    NASA Astrophysics Data System (ADS)

    Edmond, J. M.; Palmer, M. R.; Measures, C. I.; Brown, E. T.; Huh, Y.

    1996-08-01

    The fluvial geochemistry of the tributaries of the Orinoco draining the eastern branch of the northern Andes in Colombia and Venezuela is determined by lithology and ranges from rivers dominated by aluminosilicate weathering, mainly of shales and mafic rocks, to those bearing the signatures of dissolution of marine limestones and evaporites and of continental playa deposits. These left bank tributaries of the Orinoco provide the overwhelming proportion of the suspended and dissolved loads transported by the main stem although feeding only half the discharge. However, due to the extreme severity of weathering on the Guayana Shield, the right bank tributaries supply about half the silica and 40% of the K carried by the Orinoco. There is a similar partitioning between the Andes and the lowlands in the Amazon drainage. In contrast the Mackenzie, which drains the northern extremity of the continental arc of the Western Americas, is completely dominated by the weathering of limestones and evaporites and transports very little silica. This, again, appears to be a reflection of lithology since the Yukon, in similar latitudes and terrain, has silica concentrations comparable to the Tropical systems. In addition, a conservative deconvolution of the data gives estimates of the net consumption of atmospheric CO 2 by aluminosilicate weathering that follows the same pattern. Thus, the available evidence from the Western Americas indicates that exposure and lithology, rather than the climatic variables, temperature, and runoff, dominate the weathering yields in active orogenic belts. These observations contradict the conventional view of weathering processes and their controls and are at complete variance with the assumptions parameterised in most models of the geochemical cycle.

  7. 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.

  8. 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

  9. Deep-seated gravitational slope deformations along the active Boconó Fault in the central portion of the Mérida Andes, western Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A.; Beck, Christian; Carrillo, Eduardo

    2010-12-01

    Two very large deep-seated gravitational slope deformations in the highlands of the Mérida Andes, Venezuela, are herein described: the Mucubají Pass and Cerro La Camacha. These slope movements have slid in post-Last Glacial Maximum times. In addition, both landslides are in very close association with the active Boconó Fault trace. The Cerro La Camacha (Camacha Range) landslide is fault bounded along its northwest flank, whereas the Mucubají pass mass movement is even cut by the active fault trace. The almost 10 km long Mucubají slide mobilizes LGM moraine deposits along the unconformable basement contact. La Camacha slope movement is a sackung-type landslide, involving two huge masses that affect the entire northwestern slope of the La Camacha Range. This sackung is at least 20 km long, paralleling the active Boconó Fault trace. Combination of high relief energy (gravitational forces) and seismic shaking related to an on-site active fault could be responsible for the destabilization of the slopes or massif in both cases. Although the seismically-induced (re-)activation of the La Camacha landslide is very likely, there is no proof for that yet. Conversely, the Mucubají slide shows geomorphic, geodetic and sedimentary evidence of episodic activity in recent times, which could be ascribed to seismic triggering. In the particular case of the La Camacha sackung, the combination of dextral slip along the Boconó Fault and a SE-dipping fault plane could additionally favor the destabilization of the NW slope of the La Camacha Range.

  10. Geochemistry of surface and subsurface water