Sample records for venezuela interpretacion sismica

  1. Venezuela.

    PubMed

    1987-04-01

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

  2. Venezuela.

    PubMed

    1982-02-01

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

  3. Venezuela loses its forests

    Microsoft Academic Search

    Julio César Centeno

    2001-01-01

    Venezuela has one of the highest deforestation rates in Latin America. Most is due to the conversion of forests into cropland and pastures. Venezuela is also among the eight richest countries in the world in biodiversity (W.C.M.C. et al 1992). As forests disappear, the country loses one of the main supports for effective models of sustainable development.

  4. 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.

  5. THE PEARL FISHERY OF VENEZUELA

    E-print Network

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

  6. Enzootic transmission of yellow fever virus, Venezuela.

    PubMed

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

    2015-01-01

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

  7. [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

  8. Venezuela: World Oil Report 1991

    SciTech Connect

    Not Available

    1991-08-01

    This paper reports on Venezuela's expansion by state oil company PDVSA has gone from a mere concept a year ago to a well-defined plan. The five-year project that began this year and runs through 1995 received a $4-billion upgrading last fall to $25 billion. Money will be spent in increments of $5 billion/year, and all sectors are involved. Largest share, about $10.5 billion, will go to upstream projects, with $6 billion to be invested in refining, $6 billion in petrochemicals, $1.5 billion in coal and $800 million in domestic marketing. PDVSA intends to finance most of the spending directly from its cash flow. The upstream spending will go toward boosting oil production to more than 3.6 MMbpd by the beginning of 1996, with capacity topping at 4.2 MMbopd. Such heavy spending should prove a boon to the Venezuelan economy. The oil industry constitutes 23% of Venezuela's GNP, accounts for 75% of governmental revenues and produces 70% of the nation's annual foreign exchange earnings. The Ministry of Planning already is forecasting a 7% leap in real growth of the GNP this year.

  9. An Example of Educational Transformation: Venezuela.

    ERIC Educational Resources Information Center

    Cirigliano, Gustavo F. J.

    1979-01-01

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

  10. 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.

  11. Venezuela: A Study of the Educational System of Venezuela and a Guide to the Academic Placement of Students from Venezuela in Educational Institutions of the United States.

    ERIC Educational Resources Information Center

    Hoover, Gary

    Written as a guide to be used in the admission and placement of Venezuelan students in U.S. institutions of higher education, this study discusses the education system of Venezuela. The role of education in modern Venezuela and the educational structure are summarized. Information is provided on preschool and primary education, intermediate…

  12. 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)

  13. 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…

  14. Rotación de presidentes ejecutivos y directores en Venezuela

    Microsoft Academic Search

    Urbi Garay; Maximiliano González

    2005-01-01

    (Disponible en idioma inglés únicamente) El propósito de este estudio es propiciar una mejor comprensión de las estructuras y los mecanismos de conducción empresarial fuera de Estados Unidos, observando una economía emergente específica: Venezuela. Primero formulamos un índice de prácticas de conducción empresarial de las compañías inscritas en bolsa, cuyos resultados generales indican que Venezuela exhibe puntajes de gestión empresarial

  15. 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

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

    SciTech Connect

    Wood, A.

    1995-07-26

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

  17. 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.

  18. Oil Slicks on Lake Maracaibo, Venezuela

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002.

    In unpolluted areas, the water surface is 'ruffled' by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven 'capillary' waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging.

    An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26o-forward-viewing camera (center) and the 46o-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46o views, but brighter than the surrounding waters at the 26o view. Of the three images, only the 26o camera observes close to specular reflection angle.

    Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers, and utilize data from blocks 81 to 83 within World Reference System-2 path 8.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  19. 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.

  20. 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 ?M 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.

  1. 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

  2. Events affecting gold exploration in Venezuela since 1999

    USGS Publications Warehouse

    Wilburn, David R.

    2014-01-01

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

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

    PubMed

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

    2013-01-01

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

  4. The Bocono Fault Zone, Western Venezuela

    SciTech Connect

    Schubert, C. (I.V.I.C., Caracas (Venezuela)); Estevez, R. (Universidad de los Andes, Merida (Venezuela)); Henneberg, H.G. (Universidad del Zulia, Maracaibo (Venezuela))

    1993-02-01

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

  5. Original article Honey production in Venezuela: effects of feeding

    E-print Network

    Paris-Sud XI, Université de

    Original article Honey production in Venezuela: effects of feeding sugar syrup on colony weight Honey Bee Breeding, Genetics, and Physiology Laboratory, USDA, ARS, 1157 Ben Hur Road, Baton Rouge, LA, 70820; 3 Honey Bee Research, USDA, ARS, 2413 E Hwy 83, Bldg 205, Weslaco, TX 78596; 4J Whitten Research

  6. Genetic Characterization of Rabies Field Isolates from Venezuela

    Microsoft Academic Search

    CARLOS A. DEMATTOS; CECILIA C. DEMATTOS; JEAN S. SMITH; EDITH T. MILLER; SARA PAPO; ANTONIO UTRERA; ANDBENNIE I. OSBURN

    Twenty samples from cases of rabies in humans and domestic animals diagnosed in Venezuela between 1990 and 1994 and one sample from a vampire bat collected in 1976 were characterized by reactivity to monoclonal antibodiesagainsttheviralnucleoproteinandbypatternsofnucleotidesubstitutioninthenucleoproteingene. Three antigenic variants were found: 1, 3, and 5. Antigenic variant 1 included all samples from dogs and humans infected by contact with rabid dogs.

  7. Setting priorities for the conservation of Venezuela's threatened birds

    Microsoft Academic Search

    Jon Paul Rodríguez; Franklin Rojas-Suárez; Christopher J. Sharpe

    2004-01-01

    We develop and apply a four-dimensional priority-setting process for the conservation of threat- ened birds in Venezuela. The axes that we consider are extinction risk, degree of endemicity, taxonomic unique- ness and public appeal. Alhough the first three are relatively objective measures of biological attributes, the last one is a subjective judgement of the likelihood that conservation actions in favour

  8. A new species of Microphallus (Trematoda: Microphallidae) from Venezuela

    Microsoft Academic Search

    M. T. Díaz; A. K. Bashirullah; L. E. Hernández

    During 1997-1999, a total of 94 crabs, Uca rapax were collected from La Sabana, La Ceiba and El Paujil, Sucre State, Venezuela. Of these 36 were infected with metacercariae. Two parasites were located in the abdominal muscles and one under the tissue of carapace and gonad. These metacercariae grew to adults in the following genera: Levinseniella, Microphallus and Maritrema, in

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

    PubMed Central

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

    2013-01-01

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

  10. [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

  11. Epidemiologic aspects of arterial hypertension in Maracaibo, Venezuela

    Microsoft Academic Search

    T Sulbarán; E Silva; G Calmón; A Vegas

    2000-01-01

    The purpose of this study was to determine the prevalence of arterial hypertension (HT) awareness and the influence of age, sex and body mass index on the degree of control of HT in the population of Maracaibo, State of Zulia, Venezuela. It included 7424 subjects, 3640 males (M) and 3784 females (F). Information was collected through domiciliary visits with a

  12. MODIS detects oil spills in Lake Maracaibo, Venezuela

    Microsoft Academic Search

    Chuanmin Hu; Frank E. Müller-Karger; Douglas Myhre; Brock Murch; Ana L. Odriozola; Gonzalo Godoy

    2003-01-01

    Starting December 2002, the oil industry operating in and around Lake Maracaibo in Venezuela suffered a series of accidents (Figure 1). Fires, the sinking of two barges, rupture of oil pipelines, spills from floating oil storage and transfer stations, and malfunctioning of oil extraction platforms led to extensive oil spills. Local and federal Venezuelan government oil industry experts directly observed

  13. Sandfly fauna of endemic leishmaniasis foci in Anzoátegui State, Venezuela.

    PubMed

    González, R; Jorquera, A; De Sousa, L; Ledezma, E; Devera, R

    2002-01-01

    A census of the sandfly fauna was undertaken in 1993-98 in 5 endemic leishmaniasis foci situated at different altitudes in Anzoátegui State, Venezuela. From the 17 species of Lutzomyia identified, we believe that Lu. ovallesi, Lu. panamensis and Lu. gomezi are the probable vectors of cutaneous leishmaniasis, while Lu. evansi might transmit visceral leishmaniasis. PMID:11925994

  14. Anthropogenically induced fish diversity reduction in Lake Valencia Basin, Venezuela

    Microsoft Academic Search

    Héctor López-Rojas; Ana L. Bonilla-Rivero

    2000-01-01

    Lake Valencia in north central Venezuela, one of the largest natural inland bodies of water north of the equator, is undergoing a very rapid deterioration process as a consequence of anthropogenically induced changes. At the Ichthyology Laboratory of Instituto de Zoología Tropical, we have been studying the fishes of the northern tributaries of Lake Valencia since the early 1990's. As

  15. Crustal thickness variations in Venezuela from deep seismic observations

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

  16. NUEVOS REGISTROS DE Guzmania (BROMELIACEAE) PARA ALGUNOS ESTADOS DE VENEZUELA New Records of Guzmania (Bromeliaceae) from some States of Venezuela

    Microsoft Academic Search

    Yuribia Vivas; Bruce Holst

    Approximately 200 species and 17 varieties of Guzmania are known from Florida to Peru. There are recognized 28 species in Venezuela, mostly epyphytics of cloudy forests, constituting an important component in the physiognomy of these vegetable formations. Based on a survey of 751 herbarium specimens of Guzmania, nine new state records (Barinas, Falcón, Lara, Portuguesa, Trujillo y Zulia) are presented

  17. Seismological Parameters in the Northern Andes, Venezuela

    NASA Astrophysics Data System (ADS)

    Sobiesiak, M.; Palme de Osechas, C.; Choy, J. E.; Morandi S., M. T.; Campo, M.; Granado Ruiz, C.

    2001-12-01

    Venezuelas tectonic setting as part of the plate boundary between the Caribbean and the South American plate causes two major seismologically active fault systems: the roughly west - east trending strike slip fault system along the coast with numerous sub-parallel faults and the Bocono fault system, which dominates the Venezuelan southwest - northeast striking Andes. The main Bocono fault reaches a total length of about 500 km and has a width of approximately 100 km between the southern and northern baseline of the mountain slopes which are marked by inverse faults. This is believed to be due to strain partitioning, a concept which seems to apply as well to the Bocono fault system. The whole fault system is characterized by a high seismicity rate of small scale and intermediate event magnitudes ranging from 1.5 to 6.3 in the last fifty years. In this study we would like to present an investigation on 39 focal mechanism solutions and a b-value mapping of the Andean region with the main goal to throw light on the stess and strain situation. For recompiling the focal memchanisms calculated from first motion polarities, various sources had to been used: seismograms from stations of the local and regional networks of the Seismological Center of ULA, the national seismic network operated by FUNVISIS, the seismic network Lago Maracaibo of PDVSA and the local seismic network of DESURCA. For the b-value mapping we used the two catalogues of ULA and DESURCA of which the last one registered more than 6500 events from 1994 to 1999. The set of focal mechanism solutions studied showed normal, strike slip, and reverse faulting mechanisms concentrated in distinct areas of the Bocono fault system and thus resulting in a zonation also supported by the determinations of the azimuths of the maximum horizontal stress SHmax. This hypothesis of the zonation of the Andes region is strongly supported by the results of the b-value mapping. The zonation as seen in the varying major stress and strain axes is also exhilbited in the spacial distribution of the b-values. Remarkable is especially a zone in the north - eastern part of the study area with a cluster of normal fault events which is congruent with the maximum b-values observed in the b-value map.

  18. Record of source-generated overpressures, Venezuela

    SciTech Connect

    Vrolijk, P.J.; Pottorf, R.J.; Maze, W.B. [Exxon Production Research Co., Houston, TX (United States)

    1996-12-31

    Fluid pressures affect migration of oil, gas, and water in continental margins. Burial and thermal history models describe the degree to which indercompaction or thermal expansion of fluids contribute to fluid pressure histories, but it is more difficult to evaluate how source-terms, such as oil yield or mineral dehydration reactions, impact paleo-fluid pressures. In this study, we document how a thick, maturing source rock helped create near-lithostatic fluid pressures that generated overpressures in reservoir rocks. We analyzed abundant oil-filled and rare aqueous fluid inclusions in calcite-filled fractures in the La Luna Fm. source rock and in the underlying Cogollo Gp. carbonate reservoir in the W. Maracaibo Basin, Venezuela. Homogenization temperatures (Th) of oil-filled inclusions range from 25-42{degrees}C in the La Luna Fm. and from 25-105{degrees}C in the Cogollo Gp., and associated gravities (determined from fluorescence properties) range from 28-43{degrees}API and 17-45{degrees}API, respectively. Integration of Th with the burial and thermal history of the sampled horizons leads to the conclusion that fractures in the La Luna Fm. formed under near-lithostatic fluid pressure conditions in the presence of a gas-charged oil. The values from fractures in the Cogollo Gp. are higher than in the La Luna Fm and become more variable with increasing depth below La Luna. We interpret those fractures to have formed under lower fluid pressure conditions and/or with a less gas-charged oil than for La Luna. This interpretation of the distribution of paleo-fluid pressures is supported by the observation of modern inverted fluid pressure gradients between upper and lower Cogollo Gp. reservoirs. Thus late expulsion of a gas-charged oil created near-lithostatic fluid pressures in the La Luna Fm. source rock, and those fluid pressures bled downward through fractures into the adjoining reservoir rocks, contributing to the overpressures we observe today.

  19. Sediment distribution in El Tablazo Bay, Maracaibo system, Venezuela

    Microsoft Academic Search

    Felix E. Morales; Gonzalo Godoy

    1996-01-01

    The Bay of El Tablazo has an area about 640 km2, a trapezoidal form and average dimensions of 27 km (east-west) and 24 km (north-south) and serves as communication between the Gulf of Venezuela and the Lake of Maracaibo. It is a shallow body of water with small natural channels and an artificial main navigation canal, which is constantly dredged

  20. Use of molluscicides in the control of bilharziasis in Venezuela*

    PubMed Central

    Jove, José Antonio

    1956-01-01

    The application of molluscicides to the breeding-places of Australorbis glabratus—the intermediate host of Schistosoma mansoni in Venezuela—is discussed, with special reference to the equipment required and the techniques employed. The characteristics of the three molluscicides in use—copper sulfate, sodium pentachlorophenate, and copper pentachlorophenate—are outlined, and the treatment both of running waters (irrigation canals and streams) and of still waters (ponds and marshes) is described in detail. PMID:13356139

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

    PubMed Central

    Diazgranados, Mauricio; Morillo, Gilberto

    2013-01-01

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

  2. Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela

    SciTech Connect

    Salas, A. Rangel; Viloria, T. [La Universidad del Zulia (Venezuela); Sajo-Bohus, L.; Barros, H.; Greaves, E. D.; Palacios, D. [Universidad Simon Bolivar (Venezuela)

    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.

  3. Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela

    NASA Astrophysics Data System (ADS)

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

    2007-10-01

    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.

  4. 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

  5. An investigation of rainfall variability and distribution in Venezuela 

    E-print Network

    Gibson, Donald Reid

    1968-01-01

    Showing the Change of Monthly Precipitation Expressed as a Percentage of the Annual Total 41 APPENDIX H Series of Maps Showing the Change of Monthly Precipitation in Millimeters. . . . . . . . . . . . . 54 LIST OF FIGURES Page Figure 1. Map... of Venezuela. 2. Map of South America land forms. . . . . . . . . . . . . . . . . 3. Mean Isobars. 4. Mean Streamlines and ITCZ (Garbelll. . . 5. Change in monthly precipitation between Septem- ber and Gctober expressed as a percentage of the annual total...

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

    PubMed

    Laššová, Kristína; Ciampor, Fedor; Ciamporová-Za?ovi?ová, 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

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

    E-print Network

    Espinel Diaz, Arnaldo Leopoldo

    1998-01-01

    , heptane plus mole percentage and oil formation volume value for black or volatile oils, retrograde gas condensate, and wet and dry gas are presented and discussed. Representative fluid samples must be analyzed in the laboratory, but "rules of thumb..., with different fluid properties, and well completion problems, the reservoir management teain faces even a more difficult challenge than normal. In this research, we have developed a reservoir management strategy for a field located in eastern Venezuela...

  8. 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).

  9. 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…

  10. 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.

  11. 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

  12. 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…

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

    ERIC Educational Resources Information Center

    Sunal, Cynthia Szymanski; Christensen, Lois

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

  14. MARINE PALEOENVIRONMENTS OF MIOCENEPLIOCENE FORMATIONS OF NORTH-CENTRAL FALCO N STATE, VENEZUELA

    E-print Network

    Bermingham, Eldredge

    MARINE PALEOENVIRONMENTS OF MIOCENE­PLIOCENE FORMATIONS OF NORTH-CENTRAL FALCO´ N STATE, VENEZUELA Venezuela, were used in determinations of the marine paleoenvironments of the Urumaco, Codore, Caujarao, La paleoenvironments. INTRODUCTION The Cenozoic tectonic history of the northern margin of South America is complex

  15. Identificación microscópica y molecular de ehrlichias en perros del estado Aragua Venezuela

    Microsoft Academic Search

    Clara Nancy; Gutiérrez Gil; María del Carmen; Martínez Aguilera

    Microscopic and molecular identification of Ehrlicheae in dogs from Aragua-State Venezuela Bacteria of the genus Ehrlichia are obligatory intracellular microorganisms able to infect mammals, like dogs or humans. The current diagnosis method for these bacteria in Venezuela is the Buffy Coat Smear

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

    E-print Network

    Martin, Thomas E.

    BREEDING BIOLOGY AND NATURAL HISTORY OF THE SLATE-THROATED WHITESTART IN VENEZUELA ROMA´ N A. RUGGERA1,2,3 AND THOMAS E. MARTIN1 ABSTRACT.--We provide details on the breeding biology of the Slate is the most common race in the Andes of Venezuela, Colombia, and part of Ecuador. Genetic information for our

  17. PROCUREMENT SUPPORT TOOL FOR A BAR SOAP MANUFACTURING FACILITY IN VENEZUELA

    Microsoft Academic Search

    MIGUEL ANGEL MARCANO DIAZ

    2008-01-01

    ABSTRACT Laundry bar soap has been produced commercially in Venezuela for over a century and is one of the most important products for beauty and personal carethroughout the Venezuela. More than 10 Venezuelan companies produce and sell it, but two companies hold almost 85 percent of the market share, with the Las Llaves brand, alone, holding nearly 70 percent. Management,for

  18. Venezuela positioning itself to take key market role in wake of Gulf War

    SciTech Connect

    Not Available

    1991-08-19

    This paper reports on Venezuela which continues efforts to position itself in world markets to capitalize on fallout from the Persian Gulf war. The central government and state oil company Petroleos de Venezuela SA have accelerated already ambitious plans to expand activities in upstream and downstream oil and gas sectors. Pvdsa has sharply increased its 1991-96 investment program from the level planned at the end of last year. The goal is to put Venezuela on a par with major Persian Gulf oil exporters in terms of productive capacity. Linchpin of those efforts could well be further steps toward privatization of Venezuela's oil sector. For the first time since nationalization in 1976, private foreign and domestic companies are being permitted to participate in Venezuelan exploration and development. In addition, the government is trimming the onerous tax burden the oil sector has carried in Venezuela, as well as its heavy subsidy of domestic petroleum products.

  19. 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.

  20. 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.

  1. [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

  2. Escuelas e interpretaciones del pensamiento administrativo

    Microsoft Academic Search

    Francisco Velásquez Vasquez

    2002-01-01

    El artículo siguiente presenta el proceso evolutivo que ha tenido el pensamiento administrativo a lo largo del siglo XX. Se distinguen tres etapas y en cada etapa se identifica una escuela de pensamiento. Esas escuelas son: la escuela Clásica, que tuvo su desarrollo durante el período comprendido entre 1900-1930, en el mundo occidental y en los contextos culturales de los

  3. Genetic characterization of rabies field isolates from Venezuela.

    PubMed

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

    1996-06-01

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

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

    USGS Publications Warehouse

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

    2005-01-01

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

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

    ERIC Educational Resources Information Center

    Schwartzman, Karen

    1993-01-01

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

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

    ERIC Educational Resources Information Center

    Hanson, Mark

    1976-01-01

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

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

    SciTech Connect

    Algar, S. [Enterprise Oil, London (United Kingdom); Erikson, J.P. [Univ. of California, Davis, CA (United States)

    1995-04-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    E-print Network

    McGuire, Tamara Lee

    1995-01-01

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

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

    E-print Network

    Deghirmandjian, Odilia

    2001-01-01

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

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

    PubMed

    Gulbas, Lauren E

    2013-03-01

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

  12. A new species of Microphallus (Trematoda: Microphallidae) from Venezuela.

    PubMed

    Díaz, M T; Bashirullah, A K; Hernández, L E

    2004-06-01

    During 1997-1999, a total of 94 crabs, Uca rapax were collected from La Sabana, La Ceiba and El Paujil, Sucre State, Venezuela. Of these 36 were infected with metacercariae. Two parasites were located in the abdominal muscles and one under the tissue of carapace and gonad. These metacercariae grew to adults in the following genera: Levinseniella, Microphallus and Maritrema, in the period of 2-5 days after feeding experimentally to the rat Rattus norvegicus, mice Mus musculus and duck Cairinia moschata. Specimens of the genus Microphallus were described herein as a new species M. sabanensis. The life cycle of M. sabanensis sp.nov. were studied experimentally using rat, mice and duck. All developmental stages and the adult are described. In addition, M. sabanensis was collected from wild birds Anas discors, Pluvialis squatarola, Butorides striatus, Egretta caerulea and Nycticorax violaceus from the same localities. PMID:17354386

  13. Postepizootic persistence of Venezuelan equine encephalitis virus, Venezuela.

    PubMed

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

    2005-12-01

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

  14. 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.

  15. 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.

  16. Ciudadanos sin polis: democracia dual, antipolítica y sociedad civil en Venezuela Citizens without polis: dual democracy, anti-politics and civil society in Venezuela

    Microsoft Academic Search

    Colette Capriles

    In the political game taking place amidst the debris of puntofijismo (name given to the system of represen- tative democracy developed between 1958 and 1998 in Venezuela), a significant place is occupied by myths intended to explain the rise and fall of the political coordinates of the period. Among such myths, one na- rrative stands out: a certain 'epiphany of

  17. Cross sector partnership results in increased marine biodiversity information, awareness, and an initial biodiversity action plan in the Gulf of Paria, Venezuela

    Microsoft Academic Search

    F. D. Rodriguez; A. S. Carter; A. D. Rawa

    2005-01-01

    This paper describes how a pro-active cross sector partnership between organizations has successfully contributed to a better understanding of marine biodiversity and consensus among stakeholders on conservation priorities in the Gulf of Paria, Venezuela. ConocoPhillips Venezuela and its partners discovered offshore oil resources in the Gulf of Paria, northeastern Venezuela in 1999, and have since been making progress on their

  18. 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

  19. 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.

  20. PATÓGENOS DEL SUELO EN EL CULTIVO DE PIMENTÓN EN LA ZONA BAJA DEL MUNICIPIO JIMÉNEZ, ESTADO LARA, VENEZUELA

    Microsoft Academic Search

    Yoleidy Escalona; Dorian Rodríguez; Nancy Contreras; Nixon Jiménez

    2006-01-01

    Soil pathogens in bell pepper grown at the low basin of the Jimenez county of Lara State, Venezuela Bell pepper (Capsicum annuum L.) is the fourth most cultivated vegetable in Venezuela. It is affected by several diseases being, the most important those caused by soil pathogens, such as wilt, yellowing and\\/or poor development, which are found in the basin of

  1. Impacto de la luz artificial sobre la anidación de la tortuga marina Dermochelys coriacea (Testudines: Dermochelyidae), en playa Cipara, Venezuela

    Microsoft Academic Search

    María Rondón Médicci; Joaquín Buitrago; Michael Mccoy

    Impact of artificial light on nesting in the leatherback turtle Dermochelys coriacea (Testudines: Dermochelyidae) at Cipara beach, Venezuela. The number of Leatherback turtle nests and their spatial dis- tribution 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

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

    SciTech Connect

    Lugo, J. (Univ. of Texas, Austin (United States))

    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.

  3. Pros and cons of power combined cycle in Venezuela

    SciTech Connect

    Alvarez, C.; Hernandez, S. [Tecnoconsult/Tecnofluor, Caracas (Venezuela)

    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.

  4. New insights into chloramphenicol biosynthesis in Streptomyces venezuelae ATCC 10712.

    PubMed

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

    2014-12-01

    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

  5. Late quaternary environmental history of Lake Valencia, Venezuela

    USGS Publications Warehouse

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

    1981-01-01

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

  6. Cretaceous to Eocene passive margin sedimentation in Northeastern Venezuela

    SciTech Connect

    Erikson, J.P. (Dartmouth College, Hanover, NH (United States))

    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.

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

    PubMed Central

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

    2014-01-01

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

  8. 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

  9. MODIS detects oil spills in Lake Maracaibo, Venezuela

    NASA Astrophysics Data System (ADS)

    Hu, Chuanmin; Müller-Karger, Frank E.; Taylor, Charles (Judd); Myhre, Douglas; Murch, Brock; Odriozola, Ana L.; Godoy, Gonzalo

    Starting December 2002, the oil industry operating in and around Lake Maracaibo in Venezuela suffered a series of accidents (Figure 1). Fires, the sinking of two barges, rupture of oil pipelines, spills from floating oil storage and transfer stations, and malfunctioning of oil extraction platforms led to extensive oil spills. Local and federal Venezuelan government oil industry experts directly observed the series of spills from aircraft, helicopter, and various surface vessels. The spills were recorded in December by official photography and video of leaking infrastructure, and unofficial recordings continued in January and February 2003 (http://wwwcomlago.com.ve/fotosvideos. html).These surveys did not provide sufficient spatial or temporal coverage to assess the magnitude, area covered, or duration of the spills. Clear images of the spill were captured with NASAs Moderate Resolution Imaging Spectroradiometer (MODIS), however. MODIS is effectively a sophisticated digital camera launched aboard the Terra satellite in December 1999, and aboard the Aqua satellite in April 2002 [Esaias et al., 1998; http://modis.gsfc.nasa.gov]. Its medium-resolution bands (250 and 500 m resolution) are available to the public, and have great potential in coastal monitoring. This article demonstrates how MODIS can provide basic and critical assessments of oil spills.

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

    SciTech Connect

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

    1984-07-01

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

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

    SciTech Connect

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

    1989-03-01

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

  12. Energy demand management and pricing in oil-exporting countries: Venezuela and Mexico

    SciTech Connect

    Randall, L.

    1986-01-01

    The demand for energy in oil-exporting nations is important for its effects on both oil-exporting and oil-importing nations. Energy demand management takes place in the context of energy policy and national development plans, because the demand for energy is derived from the demand for other products, and because national goals are more important than those of a single sector. The energy demand management policies of Venezuela and Mexico are chosen for study because of Venezuela's historic importance as a world exporter, stable supplier of oil, and creator of OPEC, and because of Mexico's extensive oil reserves and special relationship with the United States.

  13. 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.

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

    SciTech Connect

    Vasquez-Herrera, A.R. [VVA Consultores, Caracas (Venezuela); Bereskin, S.R.; McLennan, J.D. [TerraTek, Inc., Salt Lake City, UT (United States)

    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.

  15. 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…

  16. 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)

  17. 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. [Centro Diagnostico Docente, Las Mercedes, Caracas (Venezuela); Sajo-Bohus, L.; Liendo, J. A.; Greaves, E. D.; Barros, H. [Universidad Simon Bolivar, Seccion de Fisica Nuclear, Caracas (Venezuela); Castillo, J. [University of Applied Science of Aachen (Germany)

    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.

  18. 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)

  19. 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).…

  20. 3D seismic interpretation-Norte de Paria, offshore Eastern Venezuela

    Microsoft Academic Search

    R. Ramirez de Arellano; L. van Bommel; F. Riart; J. Gil

    1993-01-01

    During 1991 a 1600 km[sup 2] 3D seismic survey was acquired for the Cristobal Colon Project, a joint venture of Lagoven (33%), Shell (30%), Exxon (29%) and Mitsubishi (8%). The objective is to evaluate the volumes of gas in the Mejillones, Patao, Dragon, and Rio Caribe gas fields, located north of the Paria Peninsula in offshore eastern Venezuela, in order

  1. Agricultural Education Needs of Farmers in Santa Barbara County, Venezuela. Summary of Research 59.

    ERIC Educational Resources Information Center

    Rodriguez, Juan F.; Henderson, Janet L.

    A study identified the perceived agricultural education needs of farmers in Santa Barbara County, Venezuela and determined the extension teaching techniques most preferred by the farmers as well as the most suitable time of the year and preferred location for receiving technical training. Data were collected from 276 farmers through face-to-face…

  2. Canales de mercadeo y comercialización del producto cárnico ovino ( Ovis aries ) en el estado Lara, Venezuela

    Microsoft Academic Search

    Ramón D'Aubeterre; Aleyda Delgado; Wilmer J. Armas; Mónica Rueda

    The main objective of this paper is to identify the different channels of commercialization of the she ep meat product in Lara state, Venezuela. Twelve years of s ystematic information is presented. This informatio n was taken among sheep farmers, intermediaries, industri als, retailers, consumers, and government agencies. Surveys were applied to the different actors related to the commercialization and

  3. Changes in soil properties and vegetation characteristics along a forest-savanna gradient in southern Venezuela

    Microsoft Academic Search

    Nelda Dezzeo; Noemí Chacón; Elio Sanoja; Gabriel Picón

    2004-01-01

    Vegetation cover in the Gran Sabana highlands (southern Venezuela) appears as a complex mosaic of tall to low forests, bush vegetation and savannas. In this study we described the changes in structure and floristic composition along a forest-savanna gradient consisted of tall forest (TF), medium forest (MF), low forest (LF) and open savanna (S), and analyse the possible reasons for

  4. Floristic composition, plant species abundance, and soil properties of montane savannas in the Gran Sabana, Venezuela

    Microsoft Academic Search

    Nelson Ramírez; Nelda Dezzeo; Noemí Chacón

    2007-01-01

    Floristic composition, species abundance, and soil properties were studied in slope, flat and disturbed savannas in the northern part of the Gran Sabana, Venezuela. All savannas presented shallow soils (<30cm depth) with high content of sand and low content of clay. In general, the soils were poor in nutrients and strongly acidified. The major difference between the soils was the

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

    E-print Network

    Garcia, Ivette

    1998-01-01

    of Block V in Lake Maracaibo, Venezuela. The VLE-1 96 area has production from the B, C2, C3, C4 and C5 reservoirs. The data from logs, cores, well tests and production are plentiful, but these data have never been correlated in an effort to compute...

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

    E-print Network

    Robock, Alan

    , induced by an enhanced green- house effect and by Amazoniandeforestation, on the phenology and yieldPOTENTIAL EFFECTS OF GLOBAL CLIMATIC CHANGE ON THE PHENOLOGY AND YIELD OF MAIZE IN VENEZUELA and another with lower than average rainfall. Scenarios associated with the greenhouse effect cause a decrease

  7. Mansonella ozzardi infections in Indians of the Southwestern part of the state of Bolivar, Venezuela.

    PubMed

    Godoy, G A; Volcan, G; Medrano, C; Teixeira, A; Matheus, L

    1980-05-01

    Mansonella ozzardi infections were found in 80/139 (58%) of Indians living in the forest of the upper Caura River Basin located in the southwestern part of Bolivar State, Venezuela. In four (3%) of the blood samples a second type of microfilaria which could not be identified was also found. PMID:6992608

  8. Population genetic structure of the dengue mosquito Aedes aegypti in Venezuela

    Microsoft Academic Search

    Flor Herrera; Ludmel Urdaneta; José Rivero; Normig Zoghbi; Johanny Ruiz; Gabriela Carrasquel; José Antonio Martínez; Martha Pernalete; Patricia Villegas; Ana Montoya; Yasmin Rubio-Palis; Elina Rojas

    2006-01-01

    The mosquito Aedes aegypti is the main vector of dengue in Venezuela. The genetic structure of this vector was investigated in 24 samples collected from eight geographic regions separated by up to 1160 km. We examined the distribution of a 359-basepair region of the NADH dehydrogenase subunit 4 mitochondrial gene among 1144 Ae. aegypti from eight collections. This gene was

  9. POPULISMO E IDENTIDADES SOCIALES EN VENEZUELA: LA CONSTRUCCION DEL ORDEN POLITICO

    Microsoft Academic Search

    Luis Ricardo Dávila

    The article seeks to outline the main elements through which a populist political order was built in Venezuela (1945-1948). It will be argued that the constitution of populist politics meant a very important form to articulate new social identities. Then it will turn to the latter Pérez and Caldera showing the basic schemes to reconstitute politics and reshape collective identities

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

    Microsoft Academic Search

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

    2011-01-01

    The main objective of this study was to demonstrate the occurrence of equine piroplasmosis (EP) in horses of Lara State, Venezuela, and to correlate it with the factors host's sex and age in order to know the epidemiology of this disease at the Venezuelan Centroccidental Region. Antibody levels to Babesia caballi and Theileria equi were assessed in 360 equine serum

  11. LA PESQUERÍA DEL CANGREJO Callinectes sapidus (DECAPODA: BRACHYURA) EN EL LAGO DE MARACAIBO, VENEZUELA

    Microsoft Academic Search

    Leonidas Villasmil; Jeremy Mendoza

    2001-01-01

    SUMMARY The blue crab Callinectes sapidus fishery in Maracaibo Lake, Venezuela is described and the stock is assessed by biom- ass dynamic models. This fishery is regionally important due to the number of jobs created in resource extraction and process- ing and export earnings obtained. Catch in metric tons and catch per unit of effort (CPUE) in kg\\/trap cover the

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

    Microsoft Academic Search

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

    2007-01-01

    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

  13. 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,…

  14. Seismic hazard analysis of western Venezuela methodology and data collection process

    Microsoft Academic Search

    Jean Savy

    1988-01-01

    This project, initiated by INTEVEP, develops a seismic hazard characterization for the region of the Lake Maracaibo basin in Western Venezuela (WV) with an emphasis at the sites of dikes built on the eastern side of the lake. One task of the project was to assess the seismicity of this region and to describe it in a form which can

  15. Accelerated Publications Three-Dimensional Structure of DesVI from Streptomyces Venezuelae: A Sugar

    E-print Network

    Holden, Hazel

    Accelerated Publications Three-Dimensional Structure of DesVI from Streptomyces Venezuelae: A Sugar,4,6-trideoxyglucose, is an unusual sugar found on the macrolide antibiotic erythromycin, and it has been shown to play, has been modeled into the active site. This model places the C-6 methyl group of the sugar

  16. Micrometeorological conditions and canopy energy exchanges of a neotropical rain forest (Surumoni-Crane Project, Venezuela)

    Microsoft Academic Search

    Jörg Szarzynski; Dieter Anhuf

    2001-01-01

    Vertical profiles of air temperature, humidity, wind speed and photosynthetically active radiation were examined systematically within and above a primary Amazonian rain forest in Southern Venezuela. During daylight hours the observed gradients of temperature and humidity suggest that turbulent mixing between vegetation and the atmosphere is reasonably efficient in the top two-thirds of the forest, whereas the understorey remains partially

  17. Ecology of the coporo, Prochilodus mariae (Characiformes, Prochilodontidae), and status of annual migrations in western Venezuela

    Microsoft Academic Search

    Aniello Barbarino Duque; Donald C. Taphorn; Kirk O. Winemiller

    1998-01-01

    Deforestation, overfishing, pollution, and construction of dams have severely impacted migratory fishes of western Venezuela. The coporo, Prochilodus mariae (Prochilodontidae), has supported the largest commercial fishery among the species that have seasonal long-distance migrations between rivers of the Andean piedmont and the llanos floodplains. During the period July 1988 to November 1990, coporo ecology was studied in the Río Boconó

  18. [Cities and oil. Historical and prospective aspects of the urban population of Venezuela].

    PubMed

    Papail, J; Picquet, M

    1989-01-01

    The authors present a historical overview of urbanization in Venezuela. The impact of the oil economy on population change and spatial distribution is emphasized. A typology of cities based on socioeconomic function and on a demographic classification of urban centers is devised. Future trends in urbanization are also considered. (SUMMARY IN ENG) PMID:12342497

  19. 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.

  20. 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.

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

    ERIC Educational Resources Information Center

    Lynch, Patrick D.

    1988-01-01

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

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

    E-print Network

    Parisca-Blanco, Sonia

    2005-01-01

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

  3. NOTA TÉCNICA REPRODUCCIÓN DE PECES Y CONSIDERACIÓN DE AMBIENTES EN EVENTOS DE CRECIDAS EN EL RÍO PORTUGUESA, VENEZUELA

    Microsoft Academic Search

    Douglas Rodríguez-Olarte; Christophe Kossowski

    2004-01-01

    Reproduction of fishes in flooding events of Portuguesa River, Venezuela The reproduction of fishes in flooding events in the Portuguesa River, Venezuela, is reported. In the high plainlands (about 100 meter above sea level) and only at specific water speeds (higher than 0.59 m\\/s) eggs presenting embryonic stages between the four-cell-embryo and the phase of independent movement of the embryo

  4. Behaviour of the red howler monkey ( Alouatta seniculus ) in the Llanos of Venezuela

    Microsoft Academic Search

    F. Braza; F. Alvarez; T. Azcarate

    1981-01-01

    The behaviour of the red howler monkey (Alouatta seniculus) in the Llanos of Venezuela was studied from May 1975 to May 1976. The average size of the social groups was 6.32.1 individuals.\\u000a The groups were heterosexual, comprising individuals of all ages, with an average of 40% adult females, 26% adult males, 16%\\u000a juveniles and 18% infants. The daily rhythm of

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  6. Heterologous expression of tylosin polyketide synthase and production of a hybrid bioactive macrolide in Streptomyces venezuelae

    Microsoft Academic Search

    Won Seok Jung; Sang Kil Lee; Jay Sung Joong Hong; Sung Ryeol Park; Soon Jeong Jeong; Ah Reum Han; Jae Kyung Sohng; Byung Gee Kim; Cha Yong Choi; David H. Sherman; Yeo Joon Yoon

    2006-01-01

    Tylosin polyketide synthase (Tyl PKS) was heterologously expressed in an engineered strain of Streptomyces venezuelae bearing a deletion of pikromycin PKS gene cluster using two compatible low-copy plasmids, each under the control of a pikAI promoter. The mutant strain produced 0.5 mg\\/l of the 16-membered ring macrolactone, tylactone, after a 4-day culture, which is a considerably reduced culture period to reach

  7. A social learning approach to the study of intrastate political violence: the case of Venezuela

    E-print Network

    Roberts, Sherman Douglas

    1971-01-01

    Operations Research Off ioe, The American Uni- versity, U. S. Arm Handbook for Venezuela (Washington, D. C. s . . Governmen r n ing ce, 1964 ), p. 321 of Ind. ependence was primarily an internal war. He also provides considerable support... for the contention that most of' tne armed. combat that took place stemmed from preexist- ing social animosities concerning race, personal grudges, family feuds, and simple exploitation of the opportunity for gain, rather than d. eep-seated. ideological loyalty...

  8. Oxygen Isotope Composition of Eclogitic and Peridotitic Garnet Xenocrysts from the La Ceniza Kimberlite, Guaniamo, Venezuela

    Microsoft Academic Search

    Daniel J. Schulze; John W. Valley; Michael J. Spicuzza; Dominic M. De R. Channer

    2003-01-01

    Although diamonds from kimberlites in the Guaniamo region of Venezuela overwhelmingly belong to the eclogite suite, the mantle xenocryst suite is dominated by peridotitic garnets, with a significant harzburgite component. In the 0.5 to 1.0 mm size fraction of heavy mineral concentrate from the La Ceniza kimberlite, approximately 23% of the garnet xenocrysts are classified as G10 (harzburgitic), 75% are

  9. 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

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

    Microsoft Academic Search

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

    2009-01-01

    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

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

    SciTech Connect

    Radford, S. [Department of Geology, Imperial College of Science, Technology and Medicine, London (United Kingdom)

    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. 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.

  13. 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

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

    PubMed

    Melandri, José Luis; de Pernía, Narcisana Espinoza

    2009-01-01

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

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

    PubMed

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

    2015-05-01

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

  16. [Control, elimination and eradication of viral immuno preventable diseases in Venezuela].

    PubMed

    Valero, Nereida; Maldonado, Mery

    2005-09-01

    Vaccination has demonstrated the capacity for the drastic decrease of the prevalence and incidence of several diseases of viral etiology and it has allowed their eradication. Among these human immuno preventable diseases are included poliomyelitis, measles, mumps, chicken pox, rubella, hepatitis A and B, influenza A and yellow fever. In residents, travelers to endemic areas and personal at risk, the vaccines to Japanese and equine encephalitis, rabies and adenovirus can be applied. Venezuela has not escaped from the positive impact in the epidemiology of these illnesses as a consequence of the organization and implementation of big national vaccination campaigns; however, and in spite of these efforts, important outbreaks of measles, yellow fever, chicken pox and hepatitis have occurred in the last few years. The tools to eliminate the majority of these viral diseases exist in Venezuela as well as in other countries, and are readily available, effective and relatively not expensive, but require on the whole of an effort of authorities and communities. The implementation of these strategies should have the support of the World Health Organization and the Panamerican Health Organization. This is a priority for the next few years if our aim is the eradication of these illnesses from Venezuela, the continent and the world. PMID:16152776

  17. 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.

  18. 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

  19. 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.

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

    USGS Publications Warehouse

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

    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.

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

    PubMed Central

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

    2012-01-01

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

  2. A novel Streptomyces spp. integration vector derived from the S. venezuelae phage, SV1

    PubMed Central

    2014-01-01

    Background Integrating vectors based on the int/attP loci of temperate phages are convenient and used widely, particularly for cloning genes in Streptomyces spp. Results We have constructed and tested a novel integrating vector based on g27, encoding integrase, and attP site from the phage, SV1. This plasmid, pBF3 integrates efficiently in S. coelicolor and S. lividans but surprisingly fails to generate stable integrants in S. venezuelae, the natural host for phage SV1. Conclusion pBF3 promises to be a useful addition to the range of integrating vectors currently available for Streptomyces molecular genetics. PMID:24885867

  3. Microfilaria bolivarensis: a new species of filaria from man in Venezuela.

    PubMed

    Godoy, G A; Orihel, T C; Volcan, G S

    1980-07-01

    An unsheathed microfilaria, unlike any other already described from man, was found in thick blood smears and Knott samples taken from Amerinds living along the upper Caura River in Bolivar State, Venezuela. The mirofilaria, which measures 256 x 7-8 micrometers in thick blood smears and 300 x 8 micrometers in Knott samples, is easily differentiated morphologically from Mansonella ozzardi with which it often occurs concomitantly. It is readily differentiated, on morphological criteria, from all other species of filariae which infect man, as well. The parasite has been named Microfilaria bolivarensis after the geographical locality in which it was discovered. PMID:7406105

  4. Biological control of Diatraea spp. (Lepidoptera: Pyralidae) in sugarcane crops in Central Venezuela.

    PubMed

    Weir, Enrique H L; Contreras, Williams; de Weir, Karine Gil

    2007-06-01

    In 1990-1996, we evaluated the relative importance of the Amazonian fly (Metagonystilum minense) and the wasp (Cotesiaflavipes), in sugarcane crops, in Central Venezuela. We observed a significant decrease in relative abundance of Diatraea spp. when the Amazon fly abundance increased but not with the wasp abundance. Diatraea spp. abundance in presence of both parasitoids was similar to its abundance throughout the last 45 years, when only inundations of M. minense occurred. However a net effect by using both parasitoids was not evident. M. minense is probably the stronger pest control, because its more efficient in its host searching than C. flavipes and is better as competitor than the wasp. PMID:19069775

  5. APTITUD FÍSICA DE TRES CLASES DE SUELOS A TRES PASTOS, EN LA PLANICIE DEL RÍO MOTATÁN, ESTADO TRUJILLO, VENEZUELA Physical suitability of the three soil class to three grass of the River Motatan lowlands, Trujillo State, Venezuela

    Microsoft Academic Search

    Neida Pineda; Edgar Jaimes; Graciano Elizalde; Guido Ochoa

    2002-01-01

    Physical suitability of three soil classes previously identified in groups and characterized through a methodology, that enables agricultural technicians and experienced farmers to define group of soils in a more understandable way, was determined. The study area covered 30,365 hectares of an alluvial sector in the Motatan River lowlands, Trujillo state, Venezuela. Land Evaluation was made using the maximum limitation

  6. VALORES BIOQUÍMICOS EN SANGRE DE LA TORTUGA VERDE (Chelonia mydas) PRESENTES EN LA ALTA GUAJIRA, VENEZUELA Blood Biochemistry Values of Green Turtle (Chelonia mydas) Present in the Alta Guajira, Venezuela

    Microsoft Academic Search

    Jim L. Hernández; Alfonso R. Bravo; Vicente J. Vera; Johan F. Mesa

    2008-01-01

    Sea turtles have been widely investigated and reviewed over the last decades. Blood biochemistry represents a valuable di- agnostic tool for monitoring the health condition of wildlife. The aim of this study was to determine the blood biochemistry val- ues of green turtles (Chelonia mydas) present in the Alta Gua- jira, Venezuela. Blood samples were collected of the dorsal cervical

  7. Importancia de las plantas medicinales en el autocuidado de la salud en tres caseríos de Santa Ana Trujillo, Venezuela. The importance of medicinal plants in health care in three small villages of the Santa Ana county at Trujillo state, Venezuela

    Microsoft Academic Search

    TEOLINDA CARRILLO-ROSARIO Y GLENDA

    In order to gather some information about the importance of medicinal plants in the primary health care, the use of plants in three small villages of the Santa Ana county, Pampán municipality at Trujillo State, Venezuela, was quantitatively analyzed. To do this, a local epidemiology diagnosis was carried out and the etnopharmacological information obtained was recorded using the TRAMIL survey.

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

    SciTech Connect

    Goodman, E.D.; Koch, P.S.; Summa, L.L. [Exxon Production Research Company, Houston, TX (United States)] [and others

    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.

  9. Is Rhodnius robustus (Hemiptera: Reduviidae) responsible for Chagas disease transmission in Western Venezuela?

    PubMed

    Feliciangeli, M Dora; Dujardin, Jean-Pierre; Bastrenta, Brigitte; Mazzarri, Milena; Villegas, Judith; Flores, Maria; Muñoz, Maruska

    2002-03-01

    We present evidence for the putative role of Rhodnius robustus as extradomestic vector of Chagas disease in Western Venezuela. First, we assessed the validity of this triatomine species by genetic characterization in relation with some other species of the prolixus group. Random amplified polymorphic DNA data showed a clear separation between this species and R. prolixus and indicated a probable genetic heterogeneity within R. robustus. Faeces and gut contents were microscopically examined in 54 of 137 R. robustus collected in palm trees. According to this morphological examination, 18% were positive for Trypanosoma cruzi, 11% harboured T. rangeli and 11% showed mixed infection. Five of the seven samples examined gave a polymerase chain reaction major band of 270 bp specific of T. cruzi. The hybridization probes showed that R. robustus may transmit clones 20 and 39 (or genetically related ones) in Venezuela. Such a transmission might occur when, in absence of domestic R. prolixus and attracted by artificial light, R. robustus enters houses and feeds on humans, or when people are bitten outdoors. The lack of bugs inside houses could mean that the insects leave houses after feeding, or die without reproducing there. PMID:11903991

  10. 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

  11. [Mollusc diversity in an Arca zebra (Mollusca: Bivalvia) community, Chacopata, Sucre, Venezuela].

    PubMed

    Prieto, A S; Ruiz, L J; García, N; Alvarez, M

    2001-06-01

    The diversity of a subtidal epifaunal mollusk community was studied from September, 1990 to September, 1991 in Chacopata, Sucre State, Venezuela. There were 40 species (24 bivalves and 16 gastropods). The diversity indexes (H' = 2.087, J' = 0.392, 1/D = 0.528) were low when compared with other tropical zones. Monthly diversity reached its maximum in September, 1990 (1.63 bits/ind.) and July, 1991 (1.60 bits/ind.); minimum diversity occurred in June, 1991 (0.52 bits/ind.). A Log series model applied to species abundance data showed a straight line with a diversity index alpha of 5.56. Of 40 species identified, the turkeywing Arca zebra was dominant (69% in number of individuals and 72% of biomass) followed by Pinctada imbricata, Modiolus squamosus, Chama macerophyla and Anadara notabilis. The predatory snails Phyllonotus pomum, Chicoreus brevifrons and Murex recurvirostris seemed to have trophic relationships with A. zebra. The total mean biomass in wet weight (469.20 +/- 263 g m-2, shell included) was high which indicates that A. zebra, a species with a rapid growth rate, occupies a central role in the assemblage as an efficient filter feeder that converts planktonic food into available biomass, supporting one of the most important fisheries in Venezuela. PMID:11935909

  12. 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.

  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. 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. (Dartmouth College, Hanover, NH (United States)); Pitman, W.C. (Lamont-Doherty Geological Observatory, Palisades, NY (United States))

    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.

  15. Seismic Anisotropy and Mantle flow beneath Western Venezuela Jeniffer Masy,1 Fenglin Niu1 and Alan Levander1

    E-print Network

    Alvarez, Pedro J.

    Seismic Anisotropy and Mantle flow beneath Western Venezuela Jeniffer Masy,1 Fenglin Niu1 and Alan are large and can be interpreted as eastward mantle flow beneath the Caribbean plate. 2. Along. Seismic anisotropy has been widely used to measure upper mantle deformation from past and present orogenic

  16. Oil in Venezuela: Triggering Violence or Ensuring Stability? A Context-sensitive Analysis of the Ambivalent Impact of Resource Abundance

    Microsoft Academic Search

    Annegret Mähler

    2009-01-01

    This paper studies the causal factors that make the oil-state Venezuela, which is generally characterized by a low level of violence, an outlier among the oil countries as a whole. It applies a newly elaborated “context approach” that systematically considers domestic and international contextual factors. To test the results of the systematic analysis, two periods with a moderate increase in

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

    Microsoft Academic Search

    J. Rodriguez-Diaz; L. Querales; L. Caraballo; E. Vizzi; F. Liprandi; H. Takiff; W. Q. Betancourt

    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

  18. Molecular characterisation of Mycobacterium tuberculosis isolates in the First National Survey of Antituberculosis Drug Resistance from Venezuela

    Microsoft Academic Search

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

    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

  19. Population, Land Use and Deforestation in the Pan Amazon Basin: a Comparison of Brazil, Bolivia, Colombia, Ecuador, Perú and Venezuela

    Microsoft Academic Search

    Stephen G. Perz; Carlos Aramburú; Jason Bremner

    2005-01-01

    This paper discusses the linkages between population change, land use, and deforestation in the Amazon regions of Brazil, Bolivia, Colombia, Ecuador, Perú, and Venezuela. We begin with a brief discussion of theories of population–environment linkages, and then focus on the case of deforestation in the PanAmazon. The core of the paper reviews available data on deforestation, population growth, migration and

  20. Biocomplexity of deforestation in the Caparo tropical forest reserve in Venezuela: An integrated multi-agent and cellular automata model

    Microsoft Academic Search

    Niandry Moreno; Raquel Quintero; Magdiel Ablan; Rodrigo Barros; Jacinto A. Dávila; Hirma Ramírez; Giorgio Tonella; Miguel F. Acevedo

    2007-01-01

    A multi-agent model of social and environmental complexity of deforestation was developed for the Caparo Forest Reserve, Venezuela. It includes three types of agents: settlers, government, and lumber concessionaires. Settlers represent people of limited economic resources that deforest and occupy reserve land to grow crops and eventually claim property rights of this land. Their agricultural practices generate unintended environmental problems.

  1. Interpretacion: The Lived Experience of Interpretation in the Bilingual Psychotherapist

    ERIC Educational Resources Information Center

    Melchor, Rosemary Laura

    2008-01-01

    To enhance the effectiveness of therapy for Spanish-speaking individuals and families requires an understanding of the subtleties of language use and interpretive processing. The purpose of this phenomenological study was to describe the interpretive process in bilingual psychotherapists as they reflected upon their lived experiences of providing…

  2. Un Modelo Cinematico para la Interpretacion Tridimensional de Proyecciones Poliedricas.

    E-print Network

    Ros, Lluís

    Federico Thomas Institut de Robotica i Informatica Industrial Gran Capita 2-4 08034 Barcelona e-mail: llros realizacion espacial del dibujo. En este trabajo abordamos un problema clasico de Robotica e Inteligencia Arti

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

    E-print Network

    Rodriguez Navas, Humberto José

    1983-01-01

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

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

    E-print Network

    Hurtado, Nuri; Torres, Julio

    2014-01-01

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

  5. [Communicative approach of Situational Strategic Planning at the local level: health and equity in Venezuela].

    PubMed

    Heredia-Martínez, Henny Luz; Artmann, Elizabeth; Porto, Silvia Marta

    2010-06-01

    The article discusses the results of operationalizing Situational Strategic Planning adapted to the local level in health, considering the communicative approach and equity in a parish in Venezuela. Two innovative criteria were used: estimated health needs and analysis of the actors' potential for participation. The problems identified were compared to the corresponding article on rights in the Venezuelan Constitution. The study measured inequalities using health indicators associated with the selected problems; equity criteria were incorporated into the action proposals and communicative elements. Priority was assigned to the problem of "low case-resolving capacity in the health services network", and five critical points were selected for the action plan, which finally consisted of 6 operations and 21 actions. The article concludes that the combination of epidemiology and planning expands the situational explanation. Incorporation of the communicative approach and the equity dimension into Situational Strategic Planning allows empowering health management and helps decrease the gaps from inequality. PMID:20657984

  6. [Characteristics of canopy plant substratum in a low land humid tropical forest (Upper Orinoco, Venezuela)].

    PubMed

    Hernández-Rosas, José Ibrahin

    2004-01-01

    By international agreement (Austria-Venezuela) a tower crane was installed near Surumoni river, Upper Orinoco, for canopy research in a tropical rain forest. From the 1.5 ha crane-accessible area of the forest, an experimental plot was selected for assessment of the canopy plants' aerial substrates and to determine their relationship with spatial distribution, presence or absence of vascular plants, and some of the strategies used in their ecological space. In the middle and lower canopy strata myrmecophytic associations appear, where the conformation of the aerial substrates determines the establishment and maintenance of these associations. The high content of nutrients of these aerial substrata represents a reservoir for the forest, where the mirmecophytic activity is determining. A higher fertility of aerial substrates of the ants gardens can be related to a higher number of vascular epiphytes present in these gardens. PMID:15916163

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

    SciTech Connect

    Paredes, I.; Fasola, A. (Intevep, S.A., Caracas (Venezuela))

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

    PubMed

    Miller, Kelly B

    2014-01-01

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

  9. 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

  10. 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.

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

    NASA Technical Reports Server (NTRS)

    Albrizzio, C.; Andressen, A.

    1974-01-01

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

  12. [Protection of mangroves in Venezuela and its impact on environment management: retrospective].

    PubMed

    Sebastiani, M; Villamizar, A; Olivo, M L

    1996-01-01

    In Venezuela, the law protects mangroves specifically. This paper is a retrospective review of the existing regulations on mangrove to find out: how has it been protected?; which have been the results of different approaches followed to do so?; which could be the problems for its protection in the near future? The result from the analysis indicates that regulations should not protect a specific mangrove species. The focal point on the regulation should be the protection of mangrove, as well as the vital relationships between this landscape unit and the existing others. Therefore, decisions of mangrove should be proposed as part of a plan for the basin where it belongs. Intervention on mangrove must be based on expert judgement, due to high uncertainty about the success of corrective or mitigative actions. PMID:9433824

  13. 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.

  14. Allele and haplotype frequencies at human leukocyte antigen class I and II genes in Venezuela's population.

    PubMed

    Del Pilar Fortes, María; Gill, Gisselle; Paredes, María Elena; Gamez, Ligia Elena; Palacios, Marina; Blanca, Isaac; Tassinari, Paolo

    2012-01-01

    Population studies represent an integral part and link in understanding the complex chain of host-pathogen interactions, disease pathogenesis, and MHC gene polymorphisms. Genes of Mongoloid, Caucasoid, and Negroid populations have created a distinctive HLA genetic profile in the Venezuelan population. Our objective was to determine the predominant HLA class I and II alleles and haplotype frequencies in the hybrid population of Venezuela. The study population consisted of 486 healthy unrelated native Venezuelans and 180 families. We examined the frequency of HLA A-B-C, HLA-DQ and HLA-DR genes by polymerase chain reaction and subsequent hybridization with sequence-specific oligonucleotide probes. Phenotypic, allelic and haplotype frequencies were estimated by direct counting and using the maximum-likelihood method. The predominant HLA class I alleles were A*02, A*24, A*68, B*35, B*44, B*51, B*07, B*15 and Cw*07. Regarding HLA class II, the most frequent alleles were DQB1*03 and DRB1*04, DRB1*15, DRB1*13, DRB1*07. The prevailing haplotype was HLA-A*02B*35 DQB1*03 DRB1*04. Some of these alleles and haplotype frequencies were predominantly present in Amerindians (A*02, A*24, B*35, Cw*07, DRB1*04, A*24 B*35). Previous reports have shown high incidence of A*02, B*44, B*51, DRB1*15, DRB1*13, DRB1*07 alleles in several European populations and A*68, B*07, B*15 alleles in African Americans, which could have contributed to the ethnic admixture of the Venezuelan population. We conclude that our results provide strong evidence that Venezuela's population represents an admixture of the primitive Mongoloid Aborigines, Caucasoid Europeans and Western African Negroid migrants. PMID:22484528

  15. 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.

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

    SciTech Connect

    George, R.P. Jr. (EGEP Consultores, Caracas (Venezuela)); Sams, R.H. (Sams Exploration Inc., Canyon Lake, TX (United States))

    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. Effects of Sucrose, Phosphate, and Calcium Carbonate on the Production of Pikromycin from Streptomyces venezuelae.

    PubMed

    Yi, Jeong Sang; Kim, Min-Suk; Kim, Sung-Jin; Kim, Byung-Gee

    2015-04-28

    Polyketide secondary metabolites share common precursor pools, acyl-CoA. Thus, the effects of engineering strategies for heterologous and native secondary metabolite production are often determined by the measurement of pikromycin in Streptomyces venezuelae. It is hard to compare the effectiveness of engineering targets among published data owing to the different pikromycin production media used from one study to the other. To determine the most important nutritional factor and establish optimal culture conditions, medium optimization of pikromycin from Streptomyces venezuelae ATCC 15439 was studied with a statistical method, Plackett-Burman design. Nine variables (glucose, sucrose, peptone, (NH4)2SO4, K2HPO4, KH2PO4, NaCl, MgSO4·7H2O, and CaCO3) were analyzed for their effects on a response, pikromycin. Glucose, K2HPO4, and CaCO3 were determined to be the most significant factors. The path of the steepest ascent and response surface methodology about the three selected components were performed to study interactions among the three factors, and the fine-tune concentrations for maximized product yields. The significant variables and optimal concentrations were 139 g/1 sucrose, 5.29 g/l K2HPO4, and 0.081 g/l CaCO3, with the maximal pikromycin yield of 35.5 mg/l. Increases of the antibiotics production by 1.45-fold, 1.3-fold, and 1.98-fold, compared with unoptimized medium and two other pikromycin production media SCM and SGGP, respectively, were achieved. PMID:25341465

  18. Venezuela kimberlites

    NASA Astrophysics Data System (ADS)

    Nixon, Peter H.; Davies, Gareth R.; Rex, David C.; Gray, Alan

    1992-04-01

    Recently discovered kimberlitic dykes and sills in the Guaniamo area of Bolivar Province (Guyana Craton) are the source of nearby extensive alluvial diamonds occurring in Recent gravels and in the Roraima sedimentary group (ca. 1.7 Ga) to the south. The intrusives are altered to nontronite and saponite but texturally are identified as Group I macrocrystic olivine rich kimberlites with identifiable monticellite and phlogopite. The REE show steep patterns and high (La/Yb) n up to 480; Cr, Ni and Nb are enriched, but LILE and Ti, Zr depleted with respect to average kimberlite, partly as a result of weathering. Leached samples yield a Rb-Sr isochron age of 1732 ± 82 Ma making them the oldest kimberlites on record. Sr and Nd isotope data are more consistent with a Group II, rather than a Group I kimberlite paragenesis. Discrete nodules (megacrysts) which typify Group I kimberlites have not been identified. There are no mantle xenoliths but mantle xenocrysts of chromium-rich pyropes and spinels, similar to those from cratonic harzburgite xenoliths of diamond facies, are abundant. The spinels show metasomatic alteration to yimengite. The kimberlites are intruded by micaceous dykes enriched in K, Ba, Sr, Zr and F indicative of a second phase of alkaline igneous activity. These igneous and metasomatic events are discussed in the context of the evolution of the Guyana Craton. Archaean metamorphism associated with the Imataca Complex spans the harzburgite chromium pyrope model Nd age (2.6 Ga). The widespread Trans-Amazonian metamorphic event (ca. 2.1 Ga) was possibly contemporaneous with mantle metasomatism indicated by yimengite formation. The kimberlites were emplaced thereafter (1.7 Ga). The micaceous dykes (0.85 Ga, {39}/{40}Ar) were generated in a mantle enriched in elements similar to those found in the earlier formed yimengite (K, Ba, Sr).

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

    Microsoft Academic Search

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

    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\\u000a DNA-A and DNA-B molecules of T217L were cloned and sequenced. The genome organization of T217L was identical to the bipartite\\u000a genomes of other begomoviruses described from the Americas. Characteristic disease symptoms were

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

    Microsoft Academic Search

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

    2010-01-01

    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

  1. Biomarker-based paleo-record of environmental change for an eutrophic, tropical freshwater lake, Lake Valencia, Venezuela

    Microsoft Academic Search

    Yunping Xu; Rudolf Jaffé

    2008-01-01

    The lipids in a sediment core from Lake Valencia, a hypereutrophic freshwater lake in Venezuela, are examined to understand\\u000a environmental changes over the last ?13,000 years. From the latest Pleistocene to the earliest Holocene, total organic carbon\\u000a (TOC) substantially increased from 2.2 to 10%, while total organic carbon over total nitrogen (TOC\\/TN) decreased from as high\\u000a as 34 to as low

  2. COMMON TIMBER NATURAL DURABILITY STUDY IN THE BAJO APURE IN VENEZUELA II: Congrio (Swartzia sericea) y salado (Vochysia lehmanii)

    Microsoft Academic Search

    Otón Holmquist; Aurora Cadenas; Pietro Pietrantonio; Andrea Piña; Alfredo Maggiorani; Lilian Bracamonte

    Following the standars of the American Society for Testing and Materials (A.S.T.M.) D: 2017-81, the natural durability of two important timbers from Bajo Apure, Venezuela, Swartzia sericea Vogel, Papilonaceae (Congrio) and Vochysia lehmanii Hieron., Vochysiaceae (Salado) were determined. Besides the two decay fungi specified by the international method Gloeophyllum trabeum and Trametes versicolor, two common wood rotters of the area

  3. Feeding ecology and postural behaviour of the three-toed sloth ( Bradypus variegatus flaccidus) in northern Venezuela

    Microsoft Academic Search

    B. Urbani; C. Bosque

    2007-01-01

    We studied the diet, activity budget, vertical ranging, and postural behaviour in relation to weather of the three-toed sloth (Bradypus variegatus flaccidus) in disturbed montane forest remnants (1150m asl) in northern Venezuela. Sloths spent most (72.9%) of their time resting and had a nearly exclusive (99.4%) leaf diet. While resting they assumed a sitting – not hanging – posture mostly

  4. 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

  5. Genetically engineered biosynthesis of macrolide derivatives including 4-amino-4,6-dideoxy-L-glucose from Streptomyces venezuelae YJ003-OTBP3.

    PubMed

    Pageni, Binod Babu; Oh, Tae-Jin; Liou, Kwangkyoung; Yoon, Yeo Joon; Sohng, Jae Kyung

    2008-01-01

    Two sugar biosynthetic cassette plasmids were used to direct the biosynthesis of a deoxyaminosugar. The pOTBP1 plasmid containing TDP-glucose synthase (desIII), TDP-glucose-4,6-dehydratase (desIV), and glycosyltransferase (desVII/desVIII) was constructed and transformed into S. venezuelae YJ003, a strain in which the entire gene cluster of desosamine biosynthesis is deleted. The expression plasmid pOTBP3 containing 4-aminotransferase (gerB) and 3,5-epimerase (orf9) was transformed again into S. venezuelae YJ003- OTBP1 to obtain S. venezuelae YJ003-OTBP3 for the production of 4-amino-4,6-dideoxy-L-glucose derivatives. The crude extracts obtained from S. venezuelae ATCC 15439, S. venezuelae YJ003, and S. venezuelae YJ003-OTBP3 were further analyzed by TLC, bioassay, HPLC, ESI/MS, LC/MS, and MS/MS. The results of our study clearly shows that S. venezuelae YJ003-OTBP3 constructs other new hybrid macrolide derivatives including 4-amino-4,6-dideoxy-L-glycosylated YC-17 (3, [M+ Na+] m/z=464.5), methymycin (4, m/z=480.5), novamethymycin (6, m/z=496.5), and pikromycin (5, m/z=536.5) from a 12- membered ring aglycon (10-deoxymethynolide, 1) and 14-membered ring aglycon (narbonolide, 2). These results suggest a successful engineering of a deoxysugar pathway to generate novel hybrid macrolide derivatives, including deoxyaminosugar. PMID:18239422

  6. Venezuela: from doctrine to dialogue to participation in the processes of regional development.

    PubMed

    Allor, D J

    1984-01-01

    The growing toward decentralization and democratization of development planning in Venezuela was discussed. Venezuela has a long tradition of rule by a strong centralized authority. Currently, the Office of the President is vested with considerable power, despite the existence of an elected legislator and an independent judiciary. The president rules by decree. State legislatures are elected, but governors of the states are appointed by the president. There are also elected municipal councils. Both state and municipal governments are almost fully dependent on the federal government for both their operating and capital investment budgets. Development programs are administered through 2 systems. Specific programs are administered by almost 100 different institutes and enterprises. The activities of these various programs are coordinated by administrative bodies at the state and federal level. The 2nd administrative system operates at the regional and federal levels. The administrative body at the federal level is the Central Office for Coordination and Planning and was established by Presidential Decree in 1958. This body prepares and coordinates all national development plans. The administrative bodies at the regional level are the Regional Organizations for Development. These bodies were created in specific regions through a series of legislative acts commencing in 1969 and continuing into the present. The development of these regional bodies represented a 1st step toward decentralization. Decree 478, promulgated in 1980, further promoted the decentalization of developmental planning. The decree established a series of assemblies and councils at various levels. A National Council of Regional Development was created at the federal level, and a Regional Council of Development was established at the regional level. At the state level an Assembly of Participation was organized, and at the municipal level a Committee of Citizen Participation was established. Neighborhood associations were mentioned in the decree, but their role was not formalized. This series of newly established bodies plays a role in both advisory and administrative processes. The advisory process begins at the lowest level, and local concerns are expressed upward through the hierarchy. The administrative process flows in the opposite direction. Participation remains highly formalized and is restricted to the participation of recognized leaders and organizations. For example, members of the Assembly of Participation include the state governor, representatives of municipal councils, and representatives of various industrial and commercial organizations. Despite the formal nature of the participation, the 1980 Decree clearly exhibited the trend toward decentralization predicted by John Freeman in his analysis of Venezuelan political structure and published in a book entitled "venezuela: From doctrine to Dialogue." Increased pressure will now be exerted for broader community participation in the development process, and eventually development planning will focus on the equitable distribution of development benefits rather than on the maximization of economic growth. PMID:12339658

  7. Geophysical studies for the identification of basin effects in urban areas in Venezuela

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Rocabado, V.; Sánchez, J.; Reinoza, C.; Amaris, E.; Cornou, C.

    2007-05-01

    Urban areas in northern Venezuela are subject to a moderate seismic hazard due to the interactions between the Caribbean and south American plates, which has been evidenced by historical damaging earthquakes as for example the 1812 and the 1967 earthquakes with a magnitude of 7.2 and 6.5, respectively. Strong damages in Caracas during the 1967 earthquake have been asociated to site effects produced by the sediment filled basin. This situation can be observed in most of the big cities in northern Venezuela, which initially developped on plain areas with quaternary basin fills of up to 500 m within mountainous areas, as for example Caracas, Maracay and Barquisimeto. In the mid- 1990ies FUNVISIS started to promote geophysical studies to investigate the shape and the properties of the basin fills in order to contribute to the earthquake disaster reduction. Methods applied for the investigations are gravimetry, microtremor measurements, seismic refraction, among others. In Caracas, a total of 350 m of cuaternary sediments with an average S-wave velocity of about 850 m/s have been derived by seismic investigations. The corresponding predominant periods from microtremor measurements amount up to 2.2 s. Integrating drilling information and 3D gravimetric modeling a detailed picture of the bedrock - sediment interface could be obtained. Results from numerical modelling as well as from experimental transfer function indicate amplifications point to amplifications of a factor of more than 10 related to the deep basin area. In Barquisimeto Metropolitan Area, sediment thickness reaches up to 500 m in the fast growing Cabudare area. Actually, modelling of a recent seismic refraction campaign is in progress, but predominant periods up to 3.0 s in the deepest part of the valley and gravity modelling point to the same order of cuaternary sediments. In other cities, as for example Carora and Mérida, geophysical studies are in progress, first with gravimetric and microtremor measurements which point to sediment with more than 150 m thickness. The subsoil information from geophysical studies will be used to define the distribution of microzones of equal seismic response in order to determine PSHA spectra. Contribution to projects FONACIT 200400738 and FONACIT-ECOS Nord 2004000347.

  8. 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

  9. Arbuscular mycorrhizas in coastal sand dunes of the Paraguaná Peninsula, Venezuela.

    PubMed

    Alarcón, C; Cuenca, G

    2005-12-01

    Arbuscular mycorrhizal colonization was measured in the most abundant plant species of the Paraguaná Peninsula, northwestern Venezuela. These plant species included: Acacia tortuosa, Argusia gnaphalodes, Croton punctatus, Croton rhamnifolius, Egletes prostrata, Melochia tomentosa, Panicum vaginatum, Scaevola plumieri, Sporobolus virginicus, Suriana maritima, Leptothrium rigidum, and Fimbristylis cymosa. Mycorrhizal colonization was assessed using the Trouvelot et al. (1986) method that allows for simultaneous evaluation of frequency of colonization (%F), intensity of colonization (%M), and the proportion of arbuscules (%A) and vesicles (%V) present in the roots. Average frequency of colonization was 69%. The highest frequency of colonization was around 92% in C. rhamnifolius and A. tortuosa; in the other species, it varied from 49 to 86%. L. rigidum and F. cymosa were considered nonmycorrhizal because its colonization was very scarce and at all times appeared without arbuscules. Average intensity of colonization was 7%. The highest intensity of colonization was 18% in C. rhamnifolius. In the other species, it varied from 3 to 15%. Paspalum vaginatum, A. gnaphalodes, M. tomentosa, and S. maritima had their fungal structures tightly packed in modified little ovoid roots. In general, frequency of AM colonization was high and similar to those reported for other tropical ecosystems, whereas the intensity of AM colonization was low and similar to values obtained in analogous studies in disturbed ecosystems. PMID:16007471

  10. Epidemiological study of paracoccidioidomycosis and histoplasmosis in a suburb of San Félix city, Bolívar state, Venezuela.

    PubMed

    Cermeño, Julman; Cermeño, Julmery; Godoy, Gerardo; Hernández, Isabel; Orellán, Yida; Blanco, Ytalia; Penna, Salvador; García, Luily; Mender, Thamara; Gonsálvez, Marisa; López, César; Hernández, Neudys; Longa, Isabel; Gottberg, Esther; Basanta, Amarilys; Castro, Milagros; Millán, Iraida; León, Walesca; Plaz, Flor; Jahouhari, Caroline; Cabello, Ismery

    2009-06-01

    Epidemiologic studies of deep mycosis have been scarce in Bolivar state, where paracoccidioidomycosis and histoplasmosis are considered as endemic diseases. The aim of this study was to determine paracoccidioidomycosis and histoplasmosis prevalences in people from a suburb of San Féix, Bolívar state, Venezuela. Three-hundred volunteers agreed to participate in this study and they were inoculated with paracoccidioidine and histoplasmine. Identification and epidemiologic data were registered. Reading of skin tests after 24 hours was performed in 275 persons. Paracoccidioidine test was positive in 10.2% (n=28). A higher percentage of positive reactions in the age group of 40-50 years old (n=10; 35.7%) was observed. Bricklayers, farmers and miners were positive in 27.3% (3 out of 11), a higher percentage than in people with other occupations. Histoplasmine test was positive in 7.6% of cases (n=21). The higher percentage of reactivity was observed in the age group of 40-50 years old (n=9; 42.9%). There was a direct proportional relationship between staying time in the locality and H. capsulatum infection mainly in persons staying in the area for more than 30 years (p < 0.05). These results showed low prevalences of P. brasiliensis and H. capsulatum infection in this area. PMID:19662816

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

    SciTech Connect

    James, K.H. [Conoco, Inc., Houston, TX (United States)

    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.

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

    SciTech Connect

    Fuentes, J. (Corpoven, Puerta La Cruz (Venezuela)); Oum, S. (TOTAL-CFP, Paris (France)); Lander, R. (Corpoven, Puerta La Cruz (Venezeula))

    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.

  13. 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

  14. Evidence for high seroprevalence of Taenia solium cysticercosis in individuals from three rural communities in Venezuela.

    PubMed

    Ferrer, Elizabeth; Cabrera, Zully; Rojas, Glenda; Lares, Maria; Vera, Andez; de Noya, Belkis Alarcon; Fernandez, Iris; Romero, Haidee Urdaneta; Harrison, Leslie J S; Parkhouse, R Michael E; Cortez, Milagros M

    2003-01-01

    A serological study was undertaken in 1998 to evaluate levels of Taenia solium cysticercosis in 3 rural Venezuelan communities. Infection with viable metacestodes was diagnosed with a trapping enzyme-linked immunosorbent assay (ELISA) that detects a secreted product of viable parasites. Anti-metacestode antibodies were assayed by ELISA using T. solium vesicular fluid as antigen. A total of 1254 sera was collected from 3 communities (Canoabo, Sanare, and Rio Tocuyo) where previous studies had suggested the presence of T. solium. Our results demonstrate an unusually high seroprevalence of cysticercosis, indicating an attendant risk of transmitting the disease to other areas. The seroprevalence of infection with viable cysts, as indicated by detection of circulating parasite antigen, was 9.1% in Canoabo, 6.1% in Sanare, and 5.7% in Rio Tocuyo. The corresponding frequency of antibodies to T. solium cyst antigens was 36.5% in Canoabo, 36.5% in Sanare, and 4% in Rio Tocuyo. As these communities are probably representative of many others in Venezuela, T. solium cysticercosis may be a significant public health problem and more work is certainly indicated. An important finding was that local knowledge of the disease and its transmission do not necessarily guarantee diminished disease prevalence, indicating a lack of appropriate vigilance towards disease control. PMID:15307416

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

    PubMed

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

    1994-01-01

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

  17. 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

  18. 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

  19. 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.

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

    USGS Publications Warehouse

    Cox, D.P.

    1993-01-01

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

  1. 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.

  2. 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.

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

    SciTech Connect

    Diaz De Gamero, M.L. (Universidad Central de Venezuela, Caracus (Venezuela)); Giffuni, G.; Castro Mora, M. (Lagoven S.A., Caracus (Venezuela))

    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.

  4. [Epidemiology of Chagas disease in Andrés Eloy Blanco, Lara, Venezuela: triatomine infestation and human seroprevalence].

    PubMed

    Rodríguez-Bonfante, Claudina; Amaro, Aned; García, María; Mejías Wohlert, Ligia Elena; Guillen, Pamela; Antonio García, Rafael; Alvarez, Naysan; Díaz, Marialejandra; Cárdenas, Elsys; Castillo, Silvia; Bonfante-Garrido, Rafael; Bonfante-Cabarcas, Rafael

    2007-05-01

    A seroepidemiological survey and vector captures were performed in four rural communities in Andrés Eloy Blanco, Lara State, Venezuela. Systematic random sampling was based on family clusters, with samples drawn from 869 individuals to determine anti-Trypanosoma cruzi and anti-Leishmania sp. antibodies by indirect immunofluorescence. Positive individuals were defined as > or = 1:32 for anti-T. cruzi antibody and non-reactive to Leishmania sp. antigen, revealing an antibody frequency of 6.9% (n = 60), of whom 46.66% were females and 53.33% males and 60% were over 39 years of age. Some 5 (8.33%) seropositive individuals were under 10 years of age and 10 (16.66%) under 20 years. Rhodnius prolixus and Panstrongylus geniculatus were the triatomines captured, with infestation rates of 1.9% and 10.54%, colonization index of 0% and 18.18% in infested houses, and a T. cruzi infection index of 20% and 5.07%, respectively. The results suggest active Chagas disease transmission in Andrés Eloy Blanco in the last two decades and that P. geniculatus is replacing R. prolixus as the Chagas disease vector. PMID:17486235

  5. 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.

  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. 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. [Lawrence Livermore National Lab., CA (United States)] [and others

    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.

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

    SciTech Connect

    Aquado, B.; Ghosh, S.; Isea, A. (Intevep, S.A., Caracas (Venezeula))

    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.

  9. The fused anthranilate synthase from Streptomyces venezuelae functions as a monomer.

    PubMed

    Ashenafi, Meseret; Reddy, Prasad T; Parsons, James F; Byrnes, W Malcolm

    2015-02-01

    Recently, we showed that the fused chorismate-utilizing enzyme from the antibiotic-producing soil bacterium Streptomyces venezuelae is an anthranilate synthase (designated SvAS), not a 2-amino-2-deoxyisochorismate (ADIC) synthase, as was predicted based on its amino acid sequence similarity to the phenazine biosynthetic enzyme PhzE (an ADIC synthase). Here, we report the characterization of SvAS using steady-state kinetics, gel filtration chromatography, and laser light scattering. The recombinant His-tagged enzyme has Michaelis constants Km with respect to substrates chorismate and glutamine of 8.2 ± 0.2 ?M and 0.84 ± 0.05 mM, respectively, and a catalytic rate constant k cat of 0.57 ± 0.02 s(-1) at 30 °C. Unlike most other anthranilate synthases, SvAS does not utilize ammonia as a substrate. The enzyme is competitively but non-cooperatively inhibited by tryptophan (K i = 11.1 ± 0.1 ?M) and is active as a monomer. The finding that SvAS is a monomer jibes with the variety of association modes that have been observed for anthranilate synthases from different microorganisms, and it identifies the enzyme's minimal functional unit as a single TrpE-TrpG pair. PMID:25355158

  10. 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.

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

    SciTech Connect

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

    1986-11-01

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

  12. 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.

  13. [Seroprevalence for Trypanosoma cruzi infection and associated factors in an endemic area of Venezuela].

    PubMed

    Bonfante-Cabarcas, Rafael; Rodríguez-Bonfante, Claudina; Vielma, Belkys Oviol; García, Douglas; Saldivia, Alexander Mogollón; Aldana, Elis; Curvelo, Juan Luis Concepción

    2011-10-01

    This study investigated risk factors associated with positive serological status for Trypanosoma cruzi antibodies in 26 rural communities including 905 households, 2,156 humans, and 333 dogs in Lara State, Venezuela. Serology was performed with ELISA and MABA. Data were obtained from entomological, demographic, and clinical surveys. Risk factors were determined through binary logistic regression. Seroprevalence was 7.24% in humans and 6.9% in canines. Positive serological status was positively associated with the Rhodnius prolixus vector, age, maternal history of Chagas disease, tobacco chewing, presence of mammals and birds in the household, household disarray, mud-and-wattle outbuildings, and animal nests and burrows in the peridomicile, and negatively associated with tobacco and alcohol consumption, history of cancer, and storage deposits in the peridomile. In conclusion, Chagas disease in this rural area is an old phenomenon transmitted by R. prolixus or by the transplacental route, associated with socio-cultural habits related to poverty, sylvatic surroundings, and the host's medical history. PMID:22031196

  14. 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

  15. Didelphis marsupialis: a primary reservoir of Trypanosoma cruzi in urban areas of Caracas, Venezuela.

    PubMed

    Herrera, L; Urdaneta-Morales, S

    1992-12-01

    Direct blood examination and xenodiagnosis of 45 sylvatic, peridomestic or domestic mammals from the Caracas valley, Venezuela, revealed trypanosome infection in six of the 24 opossums, Didelphis marsupialis, collected in urban areas. Isolates were successfully made of trypanosomes from four of the opossums, using the parasites which developed in Rhodnius prolixus fed on the infected opossums to infect NMRI mice. The prepatent period, course of parasitaemia, morphology of bloodstream trypomastigotes, tissue tropism of parasites in the opossums and/or mice, host mortality, morphology of parasites in the bugs, and infectivity to mice of parasites in the faeces of infected bugs, were all characteristic of Trypanosoma (Schizotrypanum) cruzi. In mice, the parasites showed marked myotropism; the heart, skeletal muscle and the smooth muscle of the urinary bladder, penis, prostate, seminal vesicle, lung, stomach, jejunum and colon were frequently invaded, and pseudocyts were also occasionally found in the liver, brain and pancreas. The significance of the invasion of the genito-urinary structures as a possible alternative parasite transmission route is discussed. The possible role of D. marsupialis, as a primary reservoir of T. cruzi, in the establishment of foci of Chagas' disease in Caracas and other Latin American cities, is emphasized. PMID:1304702

  16. [High prevalence of Cyclospora cayetanensis among indigenous people in Bolivar State, Venezuela].

    PubMed

    Devera, Rodolfo; Blanco, Ytalia; Cabello, Eva

    2005-01-01

    The intestinal coccidioses caused by Cryptosporidium parvum, Isospora belli, and Cyclospora cayetanensis are parasitoses of major medical importance, but many epidemiological aspects of these infections are still unknown in Bolívar State, Venezuela. To determine the prevalence of intestinal parasites and especially of intestinal coccidiosis, an indigenous population in San Antonio de Morichal was evaluated from July 2003 to April 2004. Stool samples obtained by spontaneous evacuation were preserved in potassium dichromate 2.5% and examined by the formalin-ether concentration method and Kinyoun staining. Of the 160 indigenous people examined, 92.5% (148 cases) were infected. Entamoeba coli (58.8%), Ascaris lumbricoides (38.8%), and Giardia lamblia (18.8%) were the most prevalent intestinal parasites. Coccidiosis prevalence was 13.1%, and cyclosporiasis was the most prevalent with 11.9% (19 cases). One subject with C. parvum oocysts and another with I. belli oocysts were diagnosed. There was no difference according to sex (p > 0.05) and age (chi2 = 5.6; f.g. = 6) among individuals infected with C. cayetanensis. Of these, two cases had only diarrhea. In conclusion, a high prevalence of intestinal coccidiosis infection was found among indigenous people from this community, with C. cayetanensis as the most prevalent infection. PMID:16410862

  17. [Morphogeometry of fishes in the genus Hyphessobrycon (Characiformes: Characidae), heterorhabdus group, from Venezuela].

    PubMed

    García-Alzate, Carlos A; Román-Valencia, César; González, Melissa I

    2010-09-01

    Hyphessobrycon is the most numerous and morphologically complex genus of Characidae, that includes 122 valid species, 17 of which are present in Venezuela. Different methods have been proposed for species identification within this genus. We present a morphometric analysis for the species Hyphessobrycon, heterorhabdus group. A total number of 310 individuals were photographed and analyzed by means of Box Truss method. The combination of 16 homologous landmarks and the design of Box Truss yielded 28 measurements. The Principal Components Analysis (PCA) indicated that the differences between the species are related to the distance between snout and the supraoccipital (81.7%), and between the supraoccipital and the base of the pectoral fin (11.87%). All species showed allometric growth except for Hyphessobrycon tuyensis, which resulted isometric in the Box Truss I. The partial deformations describe the form differences related to the cephalic region and the body depth. The great body form similarity is related to the phylogeny and biogeography of these species. PMID:20737839

  18. The Fused Anthranilate Synthase from Streptomyces venezuelae Functions as a Monomer

    PubMed Central

    Ashenafi, Meseret; Reddy, Prasad T.; Parsons, James F.; Byrnes, W. Malcolm

    2015-01-01

    Recently we showed that the fused chorismate-utilizing enzyme from the antibiotic-producing soil bacterium Streptomyces venezuelae is an anthranilate synthase (designated SvAS), not a 2-amino-2-deoxyisochorismate (ADIC) synthase, as was predicted based on its amino acid sequence similarity to the phenazine biosynthetic enzyme PhzE (an ADIC synthase). Here we report the characterization of SvAS using steady-state kinetics, gel filtration chromatography and laser light scattering. The recombinant His-tagged enzyme has Michaelis constants Km with respect to substrates chorismate and glutamine of 8.2 ± 0.2 ?M and 0.84 ± 0.05 mM, respectively, and a catalytic rate constant kcat of 0.57 ± 0.02 s?1 at 30°C. Unlike most other anthranilate synthases, SvAS does not utilize ammonia as a substrate. The enzyme is competitively but noncooperatively inhibited by tryptophan (Ki = 11.1 ± 0.1 ?M) and is active as a monomer. The finding that SvAS is a monomer jibes with the variety of association modes that have been observed for anthranilate synthases from different microorganisms, and it identifies the enzyme’s minimal functional unit as a single TrpE-TrpG pair. PMID:25355158

  19. 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

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

    SciTech Connect

    Lugo, J. (Lagoven S.A., Caracas (Venezuela)); Mann, P. (Univ. of Texas, Austin (United States))

    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.

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

    SciTech Connect

    Giffuni, G.; Castro-Mora, M. [Departamento de Geologia, Lagoven, S.A., Caracas (Venezuela)

    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.

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

    PubMed

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

    2012-03-01

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

  3. 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.

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

    E-print Network

    Urdaneta Anez, Jackeline C

    2001-01-01

    0305 area is a huge accumulation of Misoa formation and Eocene age, located at the South of Block V Lamar in Lake Maracaibo in Venezuela (Fig. l). The OOIP was initially estimated to be 1. 527 billion barrels of 35'API oil. Initial pressure was 5... flow rate in July 1965 of 77. 9 MSTB/D (Fig. 2). Current production is 13. 1 MSTB/D (September 1999). Approximately 539. 9 MMSTB have been produced, representing about 35. 3% of the official OOIP, which is quite low considering that this reservoir...

  5. 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

  6. [Seed morphology and anatomy of the seed coat in five species of Calliandra (Leguminosae-Mimosoideae) from Venezuela].

    PubMed

    Leython, Sirli; Jáuregui, Damelis

    2008-09-01

    Calliandra is an exclusively Neotropoical genus with 135 described species. There are 30 species in Venezuela. We studied seed morphology and the seed coat anatomy of five species: Calliandra riparia Pittier, Calliandra glomerulata Karsten var. glomerulata, Calliandra magdalenae (DC.) Bentk var. magdalenae, Calliandra surinamensis Benth and Calliandra falcata Benth., to establish simililarities and differences amongst taxa for taxonomic characterization. Of the evaluated characters, 10 quantitative characters and 3 qualitative characters were selected as the most informative for the separation of species. Seed morphological characters of taxonomic value are form and size. Thickness of the light line, number of layers and space between the osteosclereids constitute distinctive characters. PMID:19419029

  7. 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.

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

    SciTech Connect

    Pindell, J.L. (Dartmouth College, Hanover, NH (United States)); Dewey, J.F. (Oxford Univ. (United Kingdom))

    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.

  10. 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.

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

    PubMed

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

    2011-12-01

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

  12. [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

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  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. 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

  17. 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.

  18. 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.

  19. [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

  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. 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

  3. The prevalence, correlates and impact of anaemia among older people in Cuba, Dominican Republic, Mexico, Puerto Rico and Venezuela.

    PubMed

    Bryce, Renata M; Salas, Aquiles; Acosta, Daisy; Jimenez-Velazquez, Ivonne Z; Llibre-Rodriguez, Juan J; Sosa, Ana Luisa; Teruel, Beatriz Marcheco; Valhuerdi, Adolfo; Ferri, Cleusa P; McKeigue, Paul; Prince, Martin J

    2013-02-01

    Anaemia among older people is increasingly recognized as a matter of public health concern. Data from low- and middle-income countries are sparse. We surveyed 10915 people aged 65 years and over (8423 with blood tests) in catchment areas in Cuba, Dominican Republic, Puerto Rico, Venezuela and Mexico, to assess prevalence and correlates of anaemia and impact on disability. Prevalence varied widely between sites, from 6·4% in rural Mexico to 9·2% in urban Mexico, 9·8% in Venezuela, 19·2% in Cuba, 32·1% in Puerto Rico and 37·3% in Dominican Republic. Prevalence was higher in men and increased with age, but sociodemographic composition did not account for prevalence differences between sites. Standardized morbidity ratios indicated a much higher prevalence in Cuba (173), Puerto Rico (280) and Dominican Republic (332) compared with USA National Health and National Examination Surveys. Anaemia was associated with undernutrition, physical impairments, and serum creatinine. There was an association with greater African admixture in Dominican Republic but not in Cuba. African admixture is therefore unlikely to fully explain the high prevalence in the Caribbean islands, which may also arise from environmental, possibly dietary factors. Given an important independent contribution of anaemia to disability, more research is needed to identify preventable and treatable causes. PMID:23228064

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

    E-print Network

    Ramachandran, Kumar

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

  5. Marcadores biológicos de estrés oxidativo. Distribución por edad y sexo de las concentraciones basales de MDA, NO y ácido úrico en niños y adolescentes de Maracaibo-Venezuela

    Microsoft Academic Search

    Souki A; Cano C; Mengual E; García D; Torres D; Almarza J; León L; Chávez Z; Molero E; Medina M; Félix Gómez

    2007-01-01

    Despite recognition of the detrimental effects of malondial- dehyde (MDA), nitric oxide (NO) and uric acid on oxidative stress, this hypothesis has not yet been tested in healthy chil- dren and adolescents. The objective of the present study was to describe the behavior of these parameters, in a sample of healthy children and adolescents from Maracaibo, Zulia State, Venezuela. After

  6. UTLIZACIÓN DE UN SISTEMA DE INFORMACIÓN GEOGRÁFICA PARA LA SELECCIÓN Y PRIORIZACIÓN DE ÁREAS A REFORESTAR EN LOS ALREDEDORES DE LA CIUDAD DE MÉRIDA, VENEZUELA

    Microsoft Academic Search

    Ennio Pozzobon; Julián Gutiérrez

    The integration of multi-criteria evaluation (MCE) techniques with GIS and remote sensing images was used to design a model for the selection and ranking of areas to be reforested, in the surroundings of the City of Mérida, Venezuela. The information required was gathered and automated to structure the model using digital techniques; among the coverings are: a digital elevation model

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

    E-print Network

    Padron Cabral, Ricardo Javier

    1994-01-01

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

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

    Microsoft Academic Search

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

    1996-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2009-11-01

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

  10. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    USGS Publications Warehouse

    Goulding, W.; Martin, T.E.

    2010-01-01

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

  13. Regional tectonics, sequence stratigraphy and reservoir properties of Eocene clastic sedimentation, Maracaibo Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Escalona, Alejandro

    The Maracaibo basin of Venezuela is one of the most prolific hydrocarbon basins in the world. During the Paleogene, oblique collision between the Caribbean and South American plates produced a 4-km-thick wedge of clastic sediments, where over 40 billion barrels of hydrocarbons have been produced. Previous studies in the Eocene interval are focused either at a large regional scale or a field-size reservoir scale. Integration between both scales of observation has not been previously done, and, as a consequence, the effect of regional tectonics is not considered in the small-scale stratigraphic record. The aim of this dissertation is to study the interplay of tectonic and stratigraphic variables that controlled the Eocene sedimentation in the Maracaibo basin, and to establish a geologic model that incorporates data from a regional to reservoir scale. Interpretation of 2-D and 3-D seismic data in the central and eastern Maracaibo basin reveals two major tectonic features formed during Paleogene collision between the Caribbean and the South American plates: (1) a late Paleocene-early Eocene foreland basin; and (2) a middle-late Eocene lateral ramp fault. The lateral ramp fault forms a paleogeographic facies boundary separating a less faulted and folded shelf area to the west from a fold-thrust belt to the east. In the Eocene Maracaibo shelf area, intraplate deformation occurs by NNE-striking left-lateral faulting with pull-apart basins localized at fault stepovers. Three-dimensional seismic time slice interpretation of more than 2000 km2 of 3-D seismic data allows mapping of the Icotea pull-apart basin. Extension of the Icotea pull-apart basin is localized on pre-existing NW-SE-striking normal faults, formed by Paleocene-Eocene plate flexure during the foreland basin period. Detailed sequence stratigraphic interpretation of the central Maracaibo basin was carried out using 330 wells and 3-D visualization methods that combined well and 3-D seismic data techniques providing greater vertical and lateral resolution (pseudo-seismic). These data reveal that Eocene clastic sedimentation is controlled by tectonic subsidence and to a lesser degree by changes in sediment supply and eustasy. Hydrocarbon reservoirs of the central Maracaibo basin are concentrated in distributary channels and tidal sand bar facies on structural highs produced by strike-slip motion of N-NE-striking faults. Depositional environments and fluid content of Eocene reservoirs are inferred from cross sections based on closely spaced well logs.

  14. Heavy metals and organic carbon in sediments from the Tuy River basin, Venezuela.

    PubMed

    Mogollón, J L; Ramirez, A J; Guillén, R B; Bifano, C

    1990-12-01

    The Tuy River basin, located in north-central Venezuela with an annual average temperature of 27°C and precipitation of 140 cm, was selected to conduct a geochemical study of bottom sediments, with the object of establishing the natural and human influences in the abundance and distribution of Fe, Mn, Cr, Co, Cu, Ni, Pb, Zn and organic carbon. The basin is lithologically divided into two sub-basins, north and south. The north sub-basin drains a iow-grade metasedimentary terrain with a population density of 800 persons km(-2) and approximateiy 600 industrial sites, while the south sub-basin in underlain by metavolcanic and ultramafic rocks, with a population density of less than 10 persons km(-2).Stream bottom sediment samples (150) were collected during the years of 1979-1986 in 16 unpolluted sites and 13 polluted sites. The sediments were air dried at room temperature and sieved through a 120 stainless steel mesh (125 ?m). Samples of grain size smaller than 125 ?m were analysed, the heavy metals being determined by atomic absorption spectrometry and the organic carbon (Corg) by dry combustion.The higher concentrations of heavy metals and organic carbon found in the pristine areas were in the south sub-basin, especially in those areas with higher annual precipitation and tropical forest. This indicated that the metavolcanic and ultramafic rocks yield higher concentrations of heavy metals than the metasedimentary rocks. It was also noted that the higher concentrations of Cr and Ni are associated with the ultramafic rocks. The results obtained from the sediment samples collected in the polluted sites showed that the elements Pb, Zn and Corg are enriched up to 4 times as a result of ail the human activities taking place in the basin. Organic carbon is an excellent indicator of domestic wastewater, Pb and Zn are good indicators of the automotive traffic and industrial effluents. The concentrations of each heavy metal did not show any significant correlation with grain size fractions; however, the concentration of organic carbon did show a negative correlation with grain size. The lithological, climatic and vegetation influence in the abundance of heavy metals and organic carbon in stream sediments clearly indicates the necessity of establishing background levels for the area under study when carrying out studies in environmental geochemistry. PMID:24202659

  15. 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.

  16. 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.

  17. 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.

  18. Acid-fast bacterial infection and its control in guppies (Lebistes reticulatus) reared on an ornamental fish farm in Venezuela.

    PubMed

    Conroy, G; Conroy, D A

    1999-02-13

    There was a spontaneous outbreak of mycobacteriosis in fancy veiltail guppies, Lebistes reticulatus, raised on an ornamental fish farm in Venezuela. The clinical signs included listlessness, emaciation, spinal curvature, sunken eyes and loss of colour. Numerous acid-fast bacteria, identified as Mycobacterium species, were detected in smears from the kidneys, liver, mesentery and spleen of the fish, from fresh faecal material, and from the unborn embryos of infected gravid females. The bacteria were eradicated by the addition of kanamycin sulphate to the water at a concentration of 50 ppm, the dose being repeated on four occasions with 48 hours between each dose. Fifteen days after the treatment, none of the clinical signs described were detected in any of the treated fish. The offspring born to treated females were healthy and normal, and did not harbour acid-fast bacteria. PMID:10097326

  19. [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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  1. Elective surgery in patients with congenital coagulopathies and inhibitors: experience of the National Haemophilia Centre of Venezuela.

    PubMed

    Boadas, A; Fernández-Palazzi, F; De Bosch, N B; Cedeño, M; Ruiz-Sáez, A

    2011-05-01

    Elective surgery in patients with congenital haemophilia with inhibitors carries a high risk of bleeding. However, inhibitor patients also have a high risk of haemarthroses and other orthopaedic complications, and surgery could improve their quality of life. Successful elective surgery has been reported in inhibitor patients under haemostatic cover with plasma-derived activated prothrombin complex concentrate (pd-aPCC) or recombinant activated factor VII (rFVIIa). Recombinant FVIIa has recently become available in Venezuela and, unlike pd-aPCC, has not been associated with an anamnestic response. The aim of this study was to assess our experience using rFVIIa as a first-line and sustained treatment in elective invasive surgical procedures at the National Haemophilia Centre in Venezuela. Surgical procedures were classified as major or minor, under haemostatic cover with rFVIIa. A total of 13 patients (12 with haemophilia A with high-responding inhibitors and one with von Willebrand's disease type 3) underwent a total of 19 surgical procedures under rFVIIa cover. Thirteen procedures were classified as major surgeries. Intraoperative haemostasis was achieved in the majority of patients. Only two patients required an additional dose of rFVIIa, at 30 min and 75 min, respectively, with good results. Postoperative haemostasis was considered effective in 16 of 18 (89%) of the procedures in haemophilia A patients. Treatment was considered to be ineffective in two patients because of excessive postoperative bleeding. Data from the study provide no safety concerns, and demonstrate that rFVIIa provides effective haemostatic cover in elective surgery in patients with inhibitors; research is ongoing to determine the optimal dose for such procedures. PMID:21118333

  2. Relationships between carbon and hydrogen isotope ratios and nitrogen levels in leaves of Clusia species and two other Clusiaceae genera at various sites and different altitudes in Venezuela

    Microsoft Academic Search

    M. Diaz; A. Haag-Kerwer; R. Wingfield; E. Ball; E. Olivares; T. E. E. Grams; H. Ziegler; U. Lüttge

    1996-01-01

    Samples of the Clusiaceae generaClusia, Oedematopus andDystovomita were collected at various sites and different altitudes in northern and south-western Venezuela. Analyses of stable isotopes of carbon and hydrogen and of leaf-nitrogen levels were performed on the dried samples. Correlations among these variables, i.e. carbon isotope discrimination (?), hydrogen isotope ratio (?D) and N-levels, and with altitude were assessed. In the

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

  4. Anomalously high activities of 137 Cs in soils and vegetation on and near a diabase outcrop in La Sierra de Lema, Venezuela

    Microsoft Academic Search

    J. J. LaBrecque; J. A. Alfonso; P. R. Cordoves

    2008-01-01

    As a result of routine soil sampling to determine the 137Cs background activities country-wide in Venezuela, it was decided to further investigate El Mirador (Lookout) area at the\\u000a base of the Sierra de Lema mountain range. In April 2003 (A), soil samples were collected at eight sites on and around the\\u000a edge of the diabase outcrop to confirm that this

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    2009-01-01

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

  7. 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.

  8. Breeding biology of the Three-striped warbler in Venezuela: A contrast between tropical and temperate parulids

    USGS Publications Warehouse

    Cox, W.A.; Martin, T.E.

    2009-01-01

    We document reproductive life history traits of the Three-striped Warbler (Basileuterus tristriatus) from 146 nests in Venezuela and compare our results to data from the literature for other tropical and temperate parulid species. Mean (?? SE) clutch size was 1.96 ?? 0.03 eggs (n = 96) and fresh egg mass was 2.09 ?? 0.02 g. The incubation period was 15.8 ?? 0.2 days (n = 23) and the nestling period was 10.5 ?? 0.3 days (n = 12). Males did not incubate and rarely provided food for females during incubation. Females had 57 ?? 2% (n = 49) nest attentiveness (% of time on the nest incubating), which caused egg temperature to commonly become cold relative to development. Both adults fed nestlings and feeding rates increased with nestling age. The growth rate constant for nestlings based on mass was K 0.490, which is slower than for north temperate warblers. Predation was the primary source of nest failure and only 22% of nests were successful based on a Mayfield daily predation rate of 0.048 ?? 0.006. Our literature review indicates parulids differ strongly in life histories between temperate and tropical/subtropical sites with species in the tropics having, on average, smaller clutches, longer incubation periods, lower nest attentiveness, longer off-bouts, and longer nestling periods. ?? 2009 by the Wilson Ornithological Society.

  9. 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.

  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. 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.

  12. 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

  13. [Association of sardine fishery, Sardinella aurita (Teleostei: Clupeidae) and environmental variability of the coastal upwelling ecosystem of Nueva Esparta, Venezuela].

    PubMed

    Gonz?lez, Leo W; Euán, Jorge; Eslava, Nora; Suniaga, Jesús

    2007-03-01

    The present research is an analysis of Spanish sardine fishing (Sardinella aurita) associated with some climatic and meteorologic parameters of the ecosystem from El Morro Nueva Esparta, Venezuela. The catch and environmental data from the area were taken in the period 1996-2000. Catch data as a function of wind speed, sea surface temperature, air temperature and rain were analyzed by means of simple lineal regression and multiple models. We found a positive correlation of catch with wind speed, and a negative correlation with sea surface temperature, air temperature, and rain. The multiple regression model with intercept had a poor fit, therefore, we made a model without intercept, which improve greatly the fit. A selection of the variables using the forward procedure verified that the independent variables "wind speed" and "air temperature" have a significant relation with catch (p < 0.001) at real time. This method suggests that sea surface temperature and rain have little influence on the catch, and suggests a major availability of resources in the months with low air temperature and the highest wind speed (January-June). Rev. PMID:18457137

  14. 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

  15. Survey of trace metals in drinking water supplied to rural populations in the eastern Llanos of Venezuela.

    PubMed

    Mora, Abrahan; Mac-Quhae, César; Calzadilla, Malvis; Sánchez, Luzmila

    2009-02-01

    To ascertain the water quality for human consumption, chemical parameters such as pH, conductivity and total dissolved calcium, magnesium, iron, aluminum, zinc, copper and manganese were measured during four sampling periods (November 2002; March, May and July 2003) in drinking water wells which supply several forest camps and rural populations located in the eastern Llanos of Venezuela. Copper levels in drinking water in November 2002 were found to be significantly higher (P<0.05) than the other assessed periods. Temporal variations of the other parameters considered were not statistically significant. Calcium and magnesium concentrations were found to be extremely low (mean concentration+/-S.D. of 0.27+/-0.25mg/l for Ca and 0.219+/-0.118 for Mg) during the four sampling periods, probably because of the carbonate bearing scarcity in the soils lithic component. The rest of the metals complied with the Venezuelan and International guidelines of quality criteria for drinking water. PMID:18313200

  16. Structure of the Cordillera de la Costa Belt, North-Central Venezuela: Implications for plate tectronic models

    SciTech Connect

    Ave Lallemant, H.G.; Sisson, V.B.; Wright, J.E. (Rice Univ., Houston, TX (United States))

    1993-02-01

    Preliminary results of an on-going study of the Cordillera de la Costa belt between Puerto Cabello and Choroni, north-central Venezuela, indicate that the deformational history is far more complicated than expected from simple plate-tectonic models. The Cordillera de la Costa belt consists of oceanic rocks (e.g., serpentinites, amphibilites, with lenses of eclogite and blueschist) intimately intermixed with metamorphosed continental margin deposits (e.g., mica and graphite schist, quartzite, marble). Locally, large granitic (basement ) complexes of Lower Paleozoic age are included as well. In late Cretaceous time, the entire belt was involved in four synmetamorphic deformations phases (D[sub 1a] to D[sub 1d]); the first (D[sub 1a]) occurred at depths of at 35-40 km and the later ones at successively shallower depths. This deformation occurred in a subduction zone, related to right-oblique convergence of the Farallon and Atlantic plates. The most penetrative structures resulted from (all in present coordinates) north-south contraction and east-west dextral simple shear (D[sub 1b]). During an Early Tertiary ( ) event (D[sub 2]), the belt was emplaced southward onto the South American continental margin. Subsequent deformational structures (D[sub 3]) resulted in cross folds and faults (with small pull-apart basins) which are consistent with the eastward passage of the Caribbean past the South American plate.

  17. Debris-flow and flooding deposits in coastal Venezuela associated with the storm of December 14-16, 1999

    USGS Publications Warehouse

    Wieczorek, Gerald F.; Larsen, Matthew C.; Eaton, L. Scott; Morgan, Benjamin A.; Blair, J. Luke

    2002-01-01

    Heavy rainfall from the storm of December 14?16, 1999, triggered thousands of shallow landslides on steep slopes of the Sierra de Avila north of Caracas, Venezuela, and caused flooding and massive debris flows in the channels of major drainages that severely damaged coastal communities along the Caribbean Sea. Within this region we characterized geologic conditions where landslides initiated on hillsides and examined the texture of debris-flow deposits in the channels of nine drainages. In one of the most severely damaged areas on a highly developed alluvial fan at Caraballeda, we measured debris-flow deposits that ranged up to 5 meters (m) in thickness, inundating structures and roads over a large portion of the fan. Boulders up to 5 m long were carried along by the flows, impacted structures causing serious damage, and were deposited on the fan. Using field measurements and comparing pre-event and post-event topography from aerial photographs, we determined the volume of debris-flow and flood deposition on the fan to be about 2 million cubic meters. The total volume of material transported and deposited by landslides throughout the Vargas region ranks this as one of the most severe historical erosional events worldwide.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  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. [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

  7. New Neotropical Sebacinales Species from a Pakaraimaea dipterocarpacea Forest in the Guayana Region, Southern Venezuela: Structural Diversity and Phylogeography

    PubMed Central

    Moyersoen, Bernard; Weiß, Michael

    2014-01-01

    Pakaraimaea dipterocarpacea, a member of the Dipterocarpaceae endemic in the Guayana region, is associated with a diverse community of ectomycorrhizal (ECM) fungi. Amongst the 41 ECM fungal species detected in a 400 m2 P. dipterocarpacea ssp. nitida plot in Southern Venezuela, three species belonged to the Sebacinales. We tested whether ECM anatomotype characterization can be used as a feasible element in an integrative taxonomy in this diverse fungal group, where the relevance of fruitbody morphology for species delimitation seems limited. Using a combination of ECM morpho-anatomical characterizations and phylogenetic analyses based on nuclear ITS and LSU sequences, we report three new species. The main distinguishing features of Sebacina guayanensis are the yellowish cell walls together with conspicuous undifferentiated, uniform compact (type B) rhizomorphs. Staghorn-like hyphae are characteristic of S. tomentosa. The combination of clusters of thick-walled emanating hyphae, including hyphae similar to awl-shaped cystidia with basal dichotomous or trichotomous ramifications, and the presence of type B rhizomorphs were characteristic of a third, yet unnamed species. The three species belong to three different, possibly specifically tropical clades in Sebacinales Group A. The geographic distribution of phylogenetically related strains was wide, including a Dicymbe forest in Guyana and an Ecuadorian rainforest with Coccoloba species. We show that ECM morpho-anatomy can be used, in combination with other analyses, to delineate species within Sebacinales Group A. In addition to phylogenetic information, type B rhizomorphs observed in different Sebacinales clades have important ecological implications for this fungal group. The phylogeography of Sebacinales suggests that dispersion and host jump are important radiation mechanisms that shaped P. dipterocarpacea ECM fungal community. This study emphasizes the need for more sequence data to evaluate the hypothesis that phylogeographic relationships between neo- and paleotropical ECM fungal species could be attributed to the vicariance of cross-continental hosts such as the Dipterocarpacae. PMID:25072467

  8. Present-day deformation along the El Pilar Fault in eastern Venezuela: Evidence of creep along a major transform boundary

    NASA Astrophysics Data System (ADS)

    Jouanne, François; Audemard, Franck A.; Beck, Christian; Van Welden, Aurélien; Ollarves, Reinaldo; Reinoza, Carlos

    2011-05-01

    The right-lateral strike-slip El Pilar Fault is one of the major structures that accommodate the relative displacement between the Caribbean and South-America Plates. This fault, which trends East-West along the northeastern Venezuela margin, is a seismogenic source, and shows numerous evidence for active tectonics, including deformation of the Quaternary sediments filling the Cariaco Gulf. Because the main El Pilar Fault strand belongs to a set of strike-slip faults and thrusts between the stable Guyana shield (South) and the Caribbean oceanic floor (North), a GPS network was designed and installed to measure the relative motion of the El Pilar Fault and other faults. The results obtained from the comparison of 2003 and 2005 surveys indicate: (i) a lack of significant displacement (especially shortening) in the Serrania del Interior (Neogene cordillera overthrusted above the Guyana craton), (ii) an eastward displacement (relative to fixed south America plate) up to 22 mm/year of benchmarks located north of the El Pilar Fault. Velocities simulations using dislocations in an elastic half-space show: (1) the concentration along the El Pilar Fault of the whole Caribbean-South America relative displacement, (2) the existence of an important component of aseismic displacement along the upper part of the El Pilar Fault. Between 12 km depth and the surface, only 40% of displacement is locked for the western segment and 50% for the eastern segment. This last phenomenon may be related to the existence of serpentinite lenses along the fault zone as observed for segments of San Andreas and North Anatolian faults.

  9. New neotropical sebacinales species from a Pakaraimaea dipterocarpacea forest in the Guayana Region, Southern Venezuela: structural diversity and phylogeography.

    PubMed

    Moyersoen, Bernard; Wei?, Michael

    2014-01-01

    Pakaraimaea dipterocarpacea, a member of the Dipterocarpaceae endemic in the Guayana region, is associated with a diverse community of ectomycorrhizal (ECM) fungi. Amongst the 41 ECM fungal species detected in a 400 m2 P. dipterocarpacea ssp. nitida plot in Southern Venezuela, three species belonged to the Sebacinales. We tested whether ECM anatomotype characterization can be used as a feasible element in an integrative taxonomy in this diverse fungal group, where the relevance of fruitbody morphology for species delimitation seems limited. Using a combination of ECM morpho-anatomical characterizations and phylogenetic analyses based on nuclear ITS and LSU sequences, we report three new species. The main distinguishing features of Sebacina guayanensis are the yellowish cell walls together with conspicuous undifferentiated, uniform compact (type B) rhizomorphs. Staghorn-like hyphae are characteristic of S. tomentosa. The combination of clusters of thick-walled emanating hyphae, including hyphae similar to awl-shaped cystidia with basal dichotomous or trichotomous ramifications, and the presence of type B rhizomorphs were characteristic of a third, yet unnamed species. The three species belong to three different, possibly specifically tropical clades in Sebacinales Group A. The geographic distribution of phylogenetically related strains was wide, including a Dicymbe forest in Guyana and an Ecuadorian rainforest with Coccoloba species. We show that ECM morpho-anatomy can be used, in combination with other analyses, to delineate species within Sebacinales Group A. In addition to phylogenetic information, type B rhizomorphs observed in different Sebacinales clades have important ecological implications for this fungal group. The phylogeography of Sebacinales suggests that dispersion and host jump are important radiation mechanisms that shaped P. dipterocarpacea ECM fungal community. This study emphasizes the need for more sequence data to evaluate the hypothesis that phylogeographic relationships between neo- and paleotropical ECM fungal species could be attributed to the vicariance of cross-continental hosts such as the Dipterocarpacae. PMID:25072467

  10. 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

  11. Cenozoic oblique collision of South American and Caribbean plates: New evidence in the Coastal Cordillera of Venezuela and Trinidad

    SciTech Connect

    Speed, R.C. (Northwestern Univ., Evanston, IL (United States)); Russo, R.M. (Carnegie Institute of Washington (United States)); Foland, K.A. (Ohio State Univ., Columbus (United States))

    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.

  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. Seasonal variability in B speciation and B/Ca in planktonic foraminifera from the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    We determined B/Ca on four planktonic foraminiferal species (Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) on a Thermo Element 2 high resolution ICP-MS. The material is from biweekly sediment trap samples collected in Cariaco Basin, Venezuela (10o30' N, 65o31' W) over a three year period between May 2003 and May 2006. The data are compared to local hydrography and water column chemistry to evaluate environmental controls on B incorporation into foraminiferal calcite. In addition, seasonal variability of B speciation in the foraminiferal calcite is assessed using 11B magic angle spinning (MAS) nuclear magnetic resonance (NMR) on samples of O. universa from January, February, and April 2007 and of G. menardii from December 2006. The B/Ca (?mol/mol) data displays clear depth stratification with the surface dwelling G. ruber having the highest B/Ca (202 - 455), followed by G. sacculifer (137 - 335) and the deeper dwelling G. menardii and O. universa having the lowest (102 - 281; 109 - 222 respectively), consistent with a decrease in pH with depth. The data also show a repeatable seasonal pattern with the highest values occurring when the water column is stratified in June and July and the lowest occurring during upwelling in December and January. However, none of the environmental variables have a strong correlation with B/Ca. The 11B MAS NMR O. universa data show a seasonal change in the speciation of B within the foraminiferal calcite. During January the boron is almost entirely incorporated (~ 90%) in a previously unrecognized trigonal form. However, in April only ~75% of the boron is in this trigonal form, whereas the rest of the boron is divided evenly between borate and boric acid. The observed trigonal form has a Cq of 3.0, which is similar to the theoretical value of 3.15 for the corner-sharing borate carbonate complex, B(OH2)CO3-. It is hypothesized that during calcification boron is converted to a borate carbonate complex, which is ultimately converted to either borate or boric acid with each equally likely. Our results support this hypothesis except that most of the boron does not complete this reaction, but remains in the intermediate borate carbonate complex form. The December G. menardii sample matches the January O. universa sample indicating there is no species difference with respect to the form of boron incorporated into the foraminiferal test.

  14. Prevalence of musculoskeletal disorders and rheumatic diseases in an urban community in Monagas State, Venezuela: a COPCORD study.

    PubMed

    Granados, Ysabel; Cedeño, Ligia; Rosillo, Celenia; Berbin, Sol; Azocar, Miriam; Molina, María Elena; Lara, Onelia; Sanchez, Gloris; Peláez-Ballestas, Ingris

    2015-05-01

    The aim of the study was to determine the prevalence of musculoskeletal disorders and rheumatic diseases in an urban community in Venezuela. We conducted a cross-sectional, community-based study using the COPCORD (Community Oriented Program for Control of Rheumatic Diseases) methodology in subjects older than 18 years. Positive cases were evaluated by rheumatologists. We surveyed 3,973 individuals (1,606 males and 2,367 females), with a mean age of 43.7 years (standard deviation (SD) 17.6). Mean duration of education was 8.9 years (SD 3.7), 79.2 % had a monthly income of?

  15. Soil fluxes and atmospheric concentration of CO and CH4 in the Northern Part of the Guayana Shield, Venezuela

    NASA Astrophysics Data System (ADS)

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

    1990-12-01

    Soil fluxes and atmospheric concentrations of CH4 and CO were measured in a scrub grass savanna in Venezuela, during October 1988. Soil flux measurements were also made in a nearby semideciduous forest. Emission of CH4 was observed from the "dry " savanna soils; emissions do not show any significant trend with the time of day and have an average of 3.5±5.0×1010 molecules cm-2 s-1. CO fluxes show a strong diurnal variation, with net emission during daytime and consumption during nighttime. Twenty-four-hour integrated soil fluxes give a small net emission of CO of 5.6×109 molecules cm-2 s-1 this result contrasts with previous net sink estimates given in the literature. Forest soils consume both CH4 and CO at rates of -5.0×1010 and -2.4×1011 molecules cm-2 s-1 respectively. Therefore, long-range forest degradation should produce an increase in the emission of CO and CH4 from these tropical soils. At the savanna site, higher atmospheric concentrations of CH4 and CO were observed during nighttime. Minimum concentrations, representative of boundary layer conditions, were observed during hours of high solar irradiation with values of 1.78±0.04 ppm and 224±61 ppb for CH4 and CO, respectively. Using the methane concentration increase inside the nocturnal mixing height, a total methane source of 4.9×1011 molecules cm-2 s-1 from the surface was calculated, showing that a significant dispersed source, likely from termites and/or small tracts of flooded soils, is present in the tropical savanna region. Extrapolating this value to the world savanna regions, an emission of 61 Tg CH4 is estimated, this is about 10% of the global source of methane. From chamber measurements a distinct nighttime soil consumption of CO was observed; however, the concentration remained fairly constant during the night, indicating a surface source of CO of the order of 5×1010 molecules cm-2 s-1. Even though anthropogenic sources cannot be ruled out completely, termites and vegetation emission are, most likely, the dispersed sources of CO in the savanna region.

  16. La interpretacion consecutiva: metodologia y tecnicas (Consecutive Interpretation: Methodology and Techniques).

    ERIC Educational Resources Information Center

    Drallny, Ines

    1987-01-01

    Describes the purpose and appropriate methodology for various levels of interpreter training, for both consecutive and simultaneous interpretation. The importance of relating the intent of the text to the explicit language forms through which that intent is realized is discussed, and appropriate criteria for evaluation of student interpreters are…

  17. Interpretacion y Biomecanica. Hoja de consejos de PEPNet (Interpreting and Biomechanics. PEPNet Tipsheet)

    ERIC Educational Resources Information Center

    DeGroote, Bill; Morrison, Carolyn

    2010-01-01

    This publication, written in Spanish, describes cumulative trauma disorder (CTD), which refers to a collection of disorders associated with nerves, muscles, tendons, bones, and the neurovascular (nerves and related blood vessels) system. CTD symptoms may involve the neck, back, shoulders, arms, wrists, or hands. Interpreters with CTD may…

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Hamburger, T.; Matis?ns, M.; Tunved, P.; Ström, J.; Calderon, S.; Hoffmann, P.; Hochschild, G.; Gross, J.; Schmeissner, T.; Wiedensohler, A.; Krejci, R.

    2013-10-01

    First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron particle volume, number concentrations of primary particles and particle absorption were observed. Orographic lifting and shallow convection leads to a distinct diurnal cycle at the station. It enables measurements within the lower free troposphere during night-time and observations of boundary layer air masses during daytime and at their transitional regions. The seasonal cycle is defined by a wet rainy season and a dry biomass burning season. The particle load of biomass burning aerosol is dominated by fires in the Venezuelan savannah. Increases of aerosol concentrations could not be linked to long-range transport of biomass burning plumes from the Amazon basin or Africa due to effective wet scavenging of particles. Highest particle concentrations were observed within boundary layer air masses during the dry season. Ambient sub-micron particle volume reached 1.4±1.3 ?m3 cm-3, refractory particle number concentrations (at 300 °C) 510±420 cm-3 and the absorption coefficient 0.91±1.2 Mm-1. The respective concentrations were lowest within the lower free troposphere during the wet season and averaged at 0.19±0.25 ?m3 cm-3, 150±94 cm-3 and 0.15±0.26 Mm-1. A decrease of particle concentrations during the dry seasons from 2007-2009 could be connected to a decrease in fire activity in the wider region of Venezuela using MODIS satellite observations. The variability of biomass burning is most likely linked to the El Niño-Southern Oscillation (ENSO). Low biomass burning activity in the Venezuelan savannah was observed to follow La Niña conditions, high biomass burning activity followed El Niño conditions.

  20. Long-term effect of mass chemotherapy, transmission and risk factors for Schistosoma mansoni infection in very low endemic communities of Venezuela.

    PubMed

    Hofstede, Stefanie N; Tami, Adriana; van Liere, Genevieve A F S; Ballén, Diana; Incani, Renzo N

    2014-12-01

    The prevalence of Schistosoma mansoni infection in Venezuela has changed from high to low due mostly to successful control activities, including mass chemotherapy and molluscicide applications. This study examined the impact of mass chemotherapy on S. mansoni transmission and risk factors for infection 12 years after administration of praziquantel in Venezuela. Two relatively isolated rural communities were studied, one with snail control (Manuare) and the second without (Los Naranjos). A cross-sectional survey of randomly selected households included 226 (Manuare) and 192 (Los Naranjos) consenting participants. S. mansoni prevalence was determined using a combination of coprological (Kato-Katz) and serological (circumoval precipitin test, alkaline phosphatase immunoassay and Western blot) tests. Data on epidemiological and socioeconomic risk factors were obtained through individual structured interviews. Univariate analysis and multivariate logistic regression models identified independent risk factors for infection. Water sites were examined for the presence of Biomphalaria glabrata snails. Only one participant was positive by coprology. The overall prevalences according to the combined tests were 32.7% in Manuare and 26.6% in Los Naranjos. Lower prevalences (12.7% in Manuare and 13.2% in Los Naranjos) were found in children <12 years of age representing those born after mass chemotherapy. Social demographic variables associated with infection in both communities were older age (>25 years), contact with specific water sites, and being a farmer/non-specialised worker. Mass treatment with praziquantel applied once to endemic communities led to an important and long-lasting sustained reduction of S. mansoni infections independent of the application of snail control. A degree of low active transmission of S. mansoni persisted in the treated areas which was associated with similar factors in both communities. PMID:25128702

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

  2. Biosynthesis of the dideoxysugar component of jadomycin B: genes in the jad cluster of Streptomyces venezuelae ISP5230 for L-digitoxose assembly and transfer to the angucycline aglycone

    Microsoft Academic Search

    Liru Wang; Robert L. White; Leo C. Vining

    Eight additional genes, jadX, O, P, Q, S, T, U and V, in the jad cluster of Streptomyces venezuelae ISP5230, were located immediately downstream of jadN by chromosome walking. Sequence analyses and comparisons implicated them in biosynthesis of the 2,6-dideoxysugar in jadomycin B. The genes were cloned in Escherichia coli, inactivated by inserting an apramycin resistance cassette with a promoter

  3. 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

  4. [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

  5. [Chemical composition and bioactive compounds of flour of orange (Citrus sinensis), tangerine (Citrus reticulata) and grapefruit (Citrus paradisi) peels cultivated in Venezuela].

    PubMed

    Rincón, Alicia M; Vásquez, A Marina; Padilla, Fanny C

    2005-09-01

    The purpose of this research was to evaluate the chemical composition and some bioactive compounds in the peel's flour of some of the most consumed citrus fruits cultivated in Venezuela. Chemical composition as well as some trace elements, ascorbic acid, carotenoids dietary fiber, total polyphenols and their antiradical efficiency, using the 2,2-diphenyl-1-picrylhidracyl (DPPH) were assessed in the dried peels of orange (Citrus sinensis), tangerine (Citrus reticulata) and white grapefruit (Citrus paradisi). Moisture, fat, protein and ash content for all samples showed statistical differences (p < 0.05). Tangerine's peel showed the highest magnesium and carotenoid content, while highest ascorbic acid and carotenoid content was found in the grapefruit's peel. Dietary fiber content presented significant high value in the tangerine peel. All samples presented high content of extractable polyphenols (4.33; 7.6 and 5.1 g/100g). The highest antiradical efficiency was shown by the tangerine's peel, value which correlates with the polyphenol content. These results suggest that tangerine peel should be the most suitable, to reduce risk of some diseases such as cardiovascular and some associated to lipid oxidation. Studied samples are good sources of dietary fiber and phenolic compounds, whose use could be useful in the formulation of functional foods, taking advantage of the presence of dietary fiber and antioxidant compounds in only one ingredient. PMID:16454058

  6. 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

  7. 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

  8. 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. [Corpoven, S.A., La Cruz (Venezuela); Maguregui, J. [Intevep, Los Teques (Venezuela)

    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.

  9. Ecological characterization of the aquatic habitats of mosquitoes (Diptera: Culicidae) in enzootic foci of Venezuelan equine encephalitis virus in western Venezuela.

    PubMed

    Alfonzo, Dayaleth; Grillet, Maria E; Liria, Jonathan; Navarro, Juan-Carlos; Weaver, Scott C; Barrera, Roberto

    2005-05-01

    We studied the aquatic mosquito habitats in and around enzootic foci of Venezuelan Equine Encephalitis virus (VEE) in western Venezuela. Specimens were sampled for 5 mo in three types of vegetation: tall lowland tropical forests, short inundated/secondary growth forests, and pastures/herbaceous vegetation around forests. Ground pools, flooded pastures, swamps, ponds, and canals predominated. We used a multivariate statistical approach to quantitatively assess the relationships of mosquito species with broad categories of the landscape, and with environmental variables within each aquatic habitat. Twenty-four mosquito species in the genera Aedes, Psorophora, Culex, Mansonia, and Uranotaenia were collected. Species richness was higher in the tall forests than in other types of vegetation. Discriminant Function Analysis showed a strong association between landscape category and mosquito species assemblage and identified Culex erraticus Dyar & Knab and Mansonia titillans Walker as indicator species of open areas, and Aedes serratus Theobald as an indicator of tall forests. M. titillans, Uranotaenia geometrica Theobald, Cx. erraticus, and Culex dunni Dyar were associated with unshaded, warm, vegetated waters in flooded pastures and swamps, whereas Ae. serratus, Aedes fulvus (Wiedemann), Psorophora albipes Theobald, Psorophora ferox (Humboldt), Culex caudelli Dyar & Knab, and Culex pedroi Sirivanakarn & Belkin were associated with small, shaded ground pools within the tall forests. Culex coronator Dyar & Knab was associated with partially exposed sites within short forests. These results allowed us to interpret better our previous studies on mosquito adult spread in the study area and their possible role as VEEV disseminators. PMID:15962775

  10. 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.

  11. 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.

  12. Geochemistry of surface and subsurface waters in quartz-sandstones: significance for the geomorphic evolution of tepui table mountains (Gran Sabana, Venezuela)

    NASA Astrophysics Data System (ADS)

    Mecchia, Marco; Sauro, Francesco; Piccini, Leonardo; De Waele, Jo; Sanna, Laura; Tisato, Nicola; Lira, Jesus; Vergara, Freddy

    2014-04-01

    In situ measurements of discharge, pH, electric conductivity (EC), temperature, and SiO2 content have been carried out during five expeditions in the last 20 years on the summit plateaus, inside caves and along the rivers of the surrounding lowlands of three tepui massifs in Venezuela (Auyan, Roraima, and Chimanta). Additionally, detailed chemical analyses were performed on waters sampled in a newly discovered extensive quartz-sandstone cave system on the Auyan Tepui. Rock samples of the quartz-sandstone bedrock from different locations have been analysed to obtain their chemical composition with a wavelength dispersive X-ray fluorescence spectrometer. These data show that the majority of silica present in surface and subsurface water comes from dissolution of quartz and only in minor amount from hydrolysis of other silicate minerals. Probably the presence of a hardened crust of iron hydroxides limits the dissolution of silica on the top surface of tepuis. Dissolution in the subsurface, instead, is more significant and causes, in the long term, the “arenisation” of the quartz-sandstone and its subsequent removal by mechanical erosion. On the other hand, waters flowing on the arkosic rock outcropping on the lowland below the tepuis obtain their high dissolved silica content mainly from hydrolysis of silicates. The morphological evolution of these table mountains appears thus to be controlled mainly by the underground weathering of the quartz-sandstone, with the opening of deep fractures (grietas) and the collapse of large underground horizontal cave systems. Scarp retreat, instead, seems to be related to the higher weathering rate of the more arkosic formations underlying the quartz-sandstones.

  13. 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

  14. 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

  15. Varying results using the shell weights of different planktonic foraminiferal species as a proxy for changing carbonate ion concentrations in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Ocean acidification, due in part to increased atmospheric CO2, is thought to reduce calcification rates of planktonic foraminifera. A positive linear relationship has been found between foraminiferal shell weight and the carbonate ion concentrations [CO32-] of the waters in which they calcify (Barker and Elderfield, 2002). Such a relationship provides a useful proxy for determining past changes in ocean carbonate chemistry. The Cariaco Basin, Venezuela (10°30' N, 65°31 W) is an ideal study area to determine the relationship between seawater [CO32-] and planktonic foraminiferal shell weight as the region is characterized by the seasonal upwelling of low pH, low temperature, and low carbonate ion concentrated waters. In this study we use biweekly sediment trap samples and concurrent hydrographic measurements collected between January 2005 and May 2010 in the Cariaco Basin to assess the relationship between [CO32-] and shell weight of three planktonic foraminiferal species, Globigerinoides ruber, Orbulina universa and Globigerinoides sacculifer. Measured salinity, pH, sea surface temperature (SST) and total alkalinity (TA) were used to estimate pCO2 and [CO32-]. Size-normalized shells of G. ruber, O. universa and G. sacculifer were picked (> 10 per sample), photographed for size analysis and weighed. Globigerinoides ruber shell weights varied from 10.4 ?g to 17.7 ?g, with an average weight of 14.62 ?g from 2005 to 2007, with concurrent surface water [CO32-] ranging from ~220-280 ?mol/kg. Orbulina universa shell weights ranged from 35.4 ?g to 67.8 ?g with an average shell weight of 50.1 ?g. Preliminary data reveal a strong positive linear relationship between foraminiferal shell weight and [CO32-] for G. ruber (R2 = 0.52, 99% confidence level; p = 0.007) but no significant relationship for O. universa (R2 = 0.05, ; p = 0.4). The initial results suggest that the foraminiferal shell weight changes of certain planktonic foraminiferal species may reflect changes in the carbonate system better than others.

  16. A High-Resolution Stalagmite Holocene Paleoclimate Record from Northern Venezuela with Insights into the Timing and Duration of the 8.2 ka Event

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The dearth of studies and data in the tropics hinders our understanding of atmospheric and oceanic interactions between the low latitudes and the rest of the globe. To understand better the interactions, specifically between the Caribbean and the North Atlantic, three stalagmites were collected from Cueva Zarraga in the Falcón Mountains of northwestern Venezuela and analyzed to determine local paleoclimatic history. Stalagmites ages were determined by U/Th disequilibrium and show a nearly complete Holocene record. The stalagmites have an average temporal resolution of 10.8 years/mm and ranges from 2.1 to 62.7 years. Both the carbon and oxygen isotope records preserve quasi-millennial oscillations and show a major depletion shift from the last glacial period into the Holocene, suggesting warmer and wetter conditions during the Holocene. The preservation of quasi-millennial oscillations and of high frequency multi-decadal changes by the ?13C indicates that the soil-vegetation-stalagmite system is acting as an amplifier of the climatic signal produced by climatic events and changes. In the early Holocene, the ?18O record shows a depletion trend from ~ 11,000 to 8,000 cal yr BP before reaching the Holocene Thermal Maximum. A prominent ?18O enrichment event is recorded in all the stalagmites that correspond to the 8.2 ka event. The 8.2 ka event is represented by a double peak with duration of ~ 180 years. Other short-term ?18O enrichment events likely correspond to Bond events 1, 2, 5, and 6. The late Holocene record, like other Caribbean records, indicates that the climate system diverges from insolation and may represent an atmospheric rearrangement that resulted in ENSO increase instability or in reduced seasonal movement of the Inter-Tropical Convergence Zone (ITCZ). Today, Cueva Zarraga is at the northern extent of the ITCZ and has two rainy seasons. The ?18O enrichment events during the Holocene suggest drier conditions southern displacement of the ITCZ, also suggested by Brazilian speleothem records that show trends that anti-correlate with Cueva Zarraga. The Cariaco Basin and Cueva Zarraga records show similar trends. The close proximity of Cueva Zarraga to Cariaco Basin may allow for a high-resolution tropical terrestrial and oceanic climatic response comparison.

  17. New vanadium compounds in Venezuela heavy crude oil detected by positive-ion electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Zhao, Xu; Shi, Quan; Gray, Murray R; Xu, Chunming

    2014-01-01

    Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of C(n)H(2n-40)N(4)V(1)O(1) (36 ? n ? 58),C(n)H(2n-42)N(4)V(1)O(1) (37 ? n ? 57),C(n)H(2n-44)N(4)V(1)O(1) (38 ? n ? 59),C(n)H(2n-46)N(4)V(1)O(1) (43 ? n ? 54),C(n)H(2n-48)N(4)V(1)O(1) (45 ? n ? 55),C(n)H(2n-38)N(4)V(1)S(1)O(1) (36 ? n ? 41),C(n)H(2n-40)N(4)V(1)S(1)O(1) (35 ? n ? 51),C(n)H(2n-42)N(4)V(1)S(1)O(1) (36 ? n ? 54),C(n)H(2n-44)N(4)V(1)S(1)O(1) (41 ? n ? 55),C(n)H(2n-46)N(4)V(1)S(1)O(1) (39 ? n ? 55),C(n)H(2n-27)N(5)V(1)O(1) (29 ? n ? 40),C(n)H(2n-29)N(5)V(1)O(1) (34 ? n ? 42),C(n)H(2n-33)N(5)V(1)O(1) (31 ? n ? 38),C(n)H(2n-35)N(5)V(1)O(1) (32 ? n ? 41),C(n)H(2n-27)N(5)V(1)O(2) (32 ? n ? 41) and C(n)H(2n-29)N(5)V(1)O(2) (33 ? n ? 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils. PMID:24948028

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

    PubMed

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

    2009-03-01

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

  19. Biology Curriculum Reform in Venezuela.

    ERIC Educational Resources Information Center

    Rondon, Leonor Mariasole

    2001-01-01

    Describes science in the Venezuelan school system which reflects on the process of development followed to design and validate the Biology Study Programs (BSP) with the emphasis on the relevance of curricular changes proposed in biological science for secondary education. (Contains 19 references.) (ASK)

  20. Cephalopod Resources of Venezuela Introduction

    E-print Network

    . Octopus, Octopus vulgaris, is abundant in the catches from June until October, with a peak in August for Octopus vulgaris. Later, Arocha (1986) studied several aspects of the biology of Dory teuthis plei, Loligo shorttin squid Pota Ommas/rephes pteropus Orange-back squid Calamar Octopods Octopus vulgaris Octopus Pulpo

  1. La enseñanza teatral en Venezuela

    E-print Network

    Rodrí guez, Orlando

    1988-04-01

    Educación incorporó en los nueve años de la Educa ción Primaria, las artes escénicas en el plan de estudios. La formación del escolar, junto a la que recibía de artes plásticas y artes auditivas, le permitiría un conocimiento desde los primeros años que..., Argentina y Chile entre 1945 y 1950 hizo posible que la formación de los actores en las nuevas generacio nes fuera hecha con estudios sistemáticos. La presencia de Alberto de Paz y Mateos, Jesús Gómez Obregón, Juana Sujo, Horacio Peterson y Francisco...

  2. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario;ÍNDICE DE CONTENIDO GLOSARIO PROCESOS SUSTANTIVOS................................................................................ Proceso de Admisión Matrícula Estudiantil 1 Estudios Profesionales

  3. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario Consejo Directivo de fecha: #12;ÍNDICE DE CONTENIDO GLOSARIO PROCESOS SUSTANTIVOS................................................................................ Proceso de Admisión Comisión Técnica para el examen de admisión Matrícula Estudiantil 1 Estudios

  4. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario Conocido en sesión de Consejo Directivo de fecha: #12;ÍNDICE DE CONTENIDO PROCESOS SUSTANTIVOS................................................................................ Proceso de Admisión Comisión Técnica para el examen de admisión Matrícula Estudiantil 1 Estudios

  5. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario febrero de 2007 #12;ÍNDICE DE CONTENIDO PROCESOS SUSTANTIVOS................................................................................ Información Académica Admisión y Control de Estudios Proceso de Admisión Matrícula Estudiantil 1 Estudios

  6. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario noviembre de 2007 #12;ÍNDICE DE CONTENIDO GLOSARIO PROCESOS SUSTANTIVOS................................................................................ Información Académica Proceso de Admisión Matrícula Estudiantil 1 Estudios Profesionales

  7. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario noviembre de 2006 #12;ÍNDICE DE CONTENIDO PROCESOS SUSTANTIVOS................................................................................ Información Académica Admisión y Control de Estudios Proceso de Admisión Matrícula Estudiantil Egresados

  8. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario enero de 2007 #12;ÍNDICE DE CONTENIDO PROCESOS SUSTANTIVOS................................................................................ Información Académica Departamento de Admisión y Control de Estudios Proceso de Admisión Matrícula

  9. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario PROCESOS SUSTANTIVOS............................................................................ 1 DOCENCIA................................................................................ Proceso de Admisión Matrícula Estudiantil 1 Estudios Profesionales

  10. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario Conocido en sesión de Consejo Directivo de fecha: #12;ÍNDICE DE CONTENIDO GLOSARIO PROCESOS SUSTANTIVOS................................................................................ Proceso de Admisión Comisión Técnica para el examen de admisión Matrícula Estudiantil 1 Estudios

  11. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    Aura López Vicerrector Académico José Ferrer Vicerrector Administrativo Alejandro Teruel Secretario Conocido en sesión de Consejo Directivo de fecha: #12;ÍNDICE DE CONTENIDO PROCESOS SUSTANTIVOS...................................................................................................... 1 Estudios Tecnológicos Proceso de Admisión Matrícula Estudiantil 1 Estudios Profesionales

  12. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    DESARROLLO DEL CAPITAL HUMANO.............................................................. Desarrollo Académico.............................................. Desarrollo Profesoral 35 Gestión del Capital Humano

  13. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    DESARROLLO DEL CAPITAL HUMANO.............................................................. Desarrollo. Administración Desarrollo de Personal. Recursos Humanos ­ Sede del Litoral. 37 RECURSOS DE APOYO ACADÉMICO

  14. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    .................................................................................... 36 DESARROLLO DEL CAPITAL HUMANO.............................................. Desarrollo Profesoral Encuesta de Opinión Estudiantil 43 Gestión del Capital Humano

  15. UNIVERSIDAD SIMN BOLVAR Caracas -Venezuela

    E-print Network

    Vásquez, Carlos

    .................................................................................... 32 DESARROLLO DEL CAPITAL HUMANO Desarrollo del Personal Administrativo, Técnico y Obrero............. Recursos Humanos Administración Proyecto de creación Manual de Cargos Administración de Personal Recursos Humanos ­ Sede del Litoral 40

  16. Use of geostatistic techniques to describe a reservoir to be submitted into a secondary recovery process field case: {open_quotes}Eocene B-Inferior/VLG-3659, Ceuta, Venezuela{close_quotes}

    SciTech Connect

    Hernandez, T.; Poquioma, W. [Maraven, S.A., Caracas (Venezuela)

    1997-08-01

    This study presents the results of an integrated reservoir study of the Eocene B-Inferior/VLG-3659, Area 7, Ceuta filed. This field located in the Maracaibo Lake in the western side of Venezuela. The objective was to evaluating the feasibility to implement a secondary recovery project by means of water flooding. Core information was used for this study (194 ft), PVT analysis, RFI, build-up and statistic`s pressure analysis, modem logs and production history data. Using geostatistical techniques (Kriging) it was defined a low uncertainty geological model that was validated by means of a black oil simulator (Eclipse). The results showed a good comparison of historical pressure of the reservoir against those obtained from the model, without the need of {open_quotes}history matching{close_quotes}. It means without modifying neither the initial rock properties nor reservoir fluids. The results of this study recommended drilling in two new locations, also the reactivation of four producing wells and water flooding under peripherical array by means of four injection wells, with the recovery of an additional 30.2 MMSTB. The economical evaluation shows an internal return rate of 31.4%.

  17. Most frequent mutation c.3402delC (p.Ala1135GlnfsX13) among Wilson disease patients in Venezuela has a wide distribution and two old origins.

    PubMed

    Paradisi, Irene; De Freitas, Laura; Arias, Sergio

    2015-02-01

    Wilson disease is an infrequent autosomal recessive disorder caused by mutations in the ATP7B gene (13q14.3) producing pathologic phenotypes due to copper accumulation in critical tissues. The aim of the research was to probe Wilson disease genetic epidemiology in Venezuela, through the identification in diagnosed index cases, of ATP7B locus mutations, their geographic distribution, frequency, in-phase haplotypes and probable ethnic ancestry. During the last three decades 33 independent Wilson disease families from the country at large were ascertained and diagnosed through severely reduced ceruloplasmin activity, higher urinary copper excretion, and specific clinical signs. Molecular studies of the ATP7B gene were accomplished in 26 of the families. Disease prevalence was estimated as 1:94,000 families between 1985 and 2013, showing geographic aggregation in the state of Zulia with 1:27,000 families in it. DNA analysis in 26 families revealed 13 different mutations. The c.3402delC was the most frequent one (26.9%), presenting two independent in-phase haplotypes, both of likely European descent; which is followed by the not previously reported p.G691V (9.6%) and by the frequent European H1069Q (7.7%). Known mutations c.51 + 4A > T, c.1285 + 5G > T, M645R, T788I, V845SfsX28, T977M, L1088X, T1220M, R1319X and a novel P767L showed frequencies between 5.8 and 1.9%. Despite the ample mutation heterogeneity for Wilson disease in the country, the findings provide a diagnostic algorithm to ease mutation assessment in new patients; the predominant c.3402delC displayed wide geographic distribution and two genetic origins. PMID:25497208

  18. El mundo rural medieval en la historiografa en alemn desde 1930. Compromiso poltico, permanencia de las interpretaciones y dispersin de las

    E-print Network

    Boyer, Edmond

    El mundo rural medieval en la historiografía en alemán desde 1930. Compromiso político, permanencia Neither the achievements nor shortcomings of German-language historiography of medieval rural history. Consequently rural history today has only a rather marginal position, reinforced by its difficulty, not so much

  19. REPUBLICA BOLIVARIANA DE VENEZUELA LEY DE UNIVERSIDADES

    E-print Network

    Vásquez, Carlos

    espíritu de democracia, de justicia social y de solidaridad humana, y estará abierta a todas las corrientes inviolable. Su vigilancia y el mantenimiento del orden son de la competencia y responsabilidad de las

  20. El teatro de corte histórico en Venezuela

    E-print Network

    Herrera, Carlos E.

    1988-04-01

    Emilio Segura, La Guerra Civil de Lios Monasterios, Cosme II de Mediéis de Heraclio Martín de la Guardia, Lucrecia Borgia de Reinaldo Hahn Echenagucia, y El Tirano Aguirre, Guaicaipuro, Ambrosio de Alfinger de Adolfo Briceño Picón. SPRING 1988 19 A... acontecimientos. El teatro de los años cincuenta sintió el paso de una generación notable y trascendente. Nombres como Arturo Uslar Pietri, Alejandro Lasser y César Rengifo entre otros, dan dinamismo y profundidad a la dramaturgia de corte histórico. Son...

  1. UNIVERSIDAD SIMN BOLVAR Caracas-Venezuela

    E-print Network

    Vásquez, Carlos

    Administrativo José Manuel Aller Secretario Niurka Ramos Directora Sede del Litoral Elaboración y Edición.................................................................................................................vii PROCESOS SUSTANTIVOS..................................................................................................................... 1 Proceso de Admisión

  2. UNIVERSIDAD SIMN BOLVAR Caracas-Venezuela

    E-print Network

    Vásquez, Carlos

    Vicerrector Académico Benjamín Scharifker Vicerrector Administrativo José Manuel Aller Secretario Niurka Ramos ......................................................................................................vii PROCESOS SUSTANTIVOS..........................................................................1 I.....................................................................................................................1 Proceso de Admisión

  3. Snubdrilling a new well in Venezuela

    SciTech Connect

    Aasen, J.

    1995-12-01

    A new well was successfully drilled using a snubbing jack. The drill bit was rotated using a rotary table, downhole motors and combination of the two. Expected high-pressure zones prompted this use of ``snubdrilling.`` The primary objective was to drill a vertical well through underlying sands and gain information about formation pressures. This data would aid in the drilling of a relief well using a conventional drilling rig. The secondary objective was to relieve pressure by putting this new well on production. In addition to special high-pressure drilling jobs, there are other drilling applications where snubbing jacks are a feasible alternative to conventional rotary drilling rigs or coiled tubing units. Slimhole, underbalanced and flow drilling, and sidetracking of existing wells are excellent applications for snubdrilling. Advantages of snubdrilling vs. coiled tubing drilling, include ability to rotate drillstrings, use high-torque downhole motors, pump at high rates and pressures, apply significant overpull in case of stuck pipe, and run casing and liners without rigging down. Shortcomings of drilling with snubbing jacks compared to coiled tubing are the need to stop circulation while making new connections and inability to run continuous cable inside workstrings.

  4. Study Abroad in Venezuela ON-SITE GUIDE 201415

    E-print Network

    Minnesota, University of

    Names & Addresses In the United States Learning Abroad Center Study, Work, Intern, Volunteer, & Travel.626.9000 Toll Free: 888.700.UOFM Fax: 612.626.8009 Email: UMabroad@umn.edu Website: UMabroad.umn.edu Molly Micheels, Associate Program Director Email: mollym@umn.edu Phone: 612.624.3949 Holly Zimmerman Le

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

    E-print Network

    Espinel Diaz, Arnaldo Leopoldo

    1998-01-01

    must be performed to reduce the damage on the sand face. Lower formations (Cretaceous) have a lower permeability value, but high OOIP that justify performing fracture treatments and completing this zone. Economics were developed to support...

  6. Measuring political polarization: Twitter shows the two sides of Venezuela

    NASA Astrophysics Data System (ADS)

    Morales, A. J.; Borondo, J.; Losada, J. C.; Benito, R. M.

    2015-03-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Chávez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  7. Overpressure history of fractures, West Maracaibo Basin, Venezuela

    SciTech Connect

    Vrolijk, P.J.; Pottorf, R.J.; Maze, W.B. [Exxon Production Research Co., Houston, TX (United States)

    1996-08-01

    Prediction of density of natural fractures in reservoir rocks requires evaluation of many factors, including the effective stress and thus fluid pressure conditions through time. In this study we use analyses of fluid inclusions in calcite-filled fractures with burial and thermal history models to assess the fluid pressure history and the causes of overpressure in the West Maracaibo Basin. We analyzed abundant oil-filled and rare aqueous fluid inclusions in calcite-filled fractures in the La Luna Formation source rock and in the underlying Cogollo Gp. carbonate reservoir. Our analyses of fluid inclusion homogenization temperatures and fluorescence properties lead us to the interpretation of near-lithostatic paleo-fluid pressures in La Luna Formation and near-lithostatic to hydrostatic fluid pressures in the Cogollo, Gp. fractures. Maturation and expulsion of oil from the La Luna Formation source rock is required to generate the large inferred excess pressures as compaction disequilibrium and thermal expansion of pore fluids from rapid Miocene burial are insufficient to achieve near-lithostatic conditions. This hypothesis is supported by the observation of decreasing paleo- and modern fluid pressures with depth beneath the La Luna Formation. Thus based on the wide occurrence of oil-filled inclusions in calcite-filled fractures and the high fluid pressures associated with trapped oils, we infer extensive rock fracture under overpressured conditions near maximum Miocene burial, during inferred late source rock yield, and during Miocene growth of structural traps.

  8. Geology and geomorphology of the Roraima group, southeastern Venezuela

    NASA Astrophysics Data System (ADS)

    Yanezpintado, G.

    A moderately detailed, accurate geologic geomorphologic map of the Roraima region at a 1:250,000 scale was prepared. This provides a suitable base for future, more detailed studies. It is recommended that the Roraima Formation be raised to Group status and include three apparently conformable but lithogically separable Formations from the base upwards, these are the Canaima, Gualaquinima, and Auyantepui formation. Two composite stratigraphic sections are established and formational thicknesses determined near Santa Elena de U. and Canaima. Radar imagery and aerial photo interpretation allows improved mapping of regional and local structures. Broad, gentle, postdepositional folding of the Roraima into anteclises and syneclises apparently was followed by intrusion of basic dikes and sills; the principal host is the Canaima Formation. Diamond bearing places in the present alluvial valleys are the result of continuous deposition, reworking and redeposition of older, more geographically disjunct floodplain and deltaic sediments.

  9. Sur Lago area, Venezuela: Three dimensional integrated seismic interpretation

    Microsoft Academic Search

    A. Growcott; A. McIan; R. Ramirez

    1993-01-01

    In 1988, 550 square km of 3D seismic data were acquired in the Sur Del Lago area. The aims of the survey were (1) To better define structures already identified from the existing 1 [times] 1 km 2D seismic grid at the level of potential Cretaceous limestone reservoirs and (2) To further study the prospectivity of potential structural and stratigraphic

  10. Ceuta area, Lake Maracaibo, Venezuela. 3D integrates seismic interpretation

    Microsoft Academic Search

    E. Ramirez; A. McIan

    1993-01-01

    Maraven S.A. is currently carrying out an aggressive 3D acquisition campaign in the Lake Maracaibo area. Data will be and has been recorded to totally cover the Maraven exploration and production acreage. To further understand the complex tectonics of the Ceuta area a new 3D seismic interpretation has led to a revision of the structural model. The current model envisages

  11. LA ASAMBLEA NACIONAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA

    E-print Network

    Vásquez, Carlos

    como principios de la educación, la democracia participativa y protagónica, la responsabilidad social constitucionales y orientada por valores éticos humanistas para la transformación social, así como las bases formación en una cultura para la paz, la justicia social, el respeto a los derechos humanos, la práctica de

  12. Measuring Political Polarization: Twitter shows the two sides of Venezuela

    E-print Network

    Morales, A J; Losada, J C; Benito, R M

    2015-01-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Ch\\'avez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  13. The Resource Relationship: The Institutional Legacies of Oil in Venezuela

    NASA Astrophysics Data System (ADS)

    Bridgewater, Elliot

    This thesis problematizes the concept of the 'Resource Curse', addressing the arguments of several theorists that resource dependence results in state monopolization of natural resource production, and causes poor development outcomes in resource dependent states. A single case study of the Venezuelan experience is used in order to take a longer-run historical approach that considers economic and political determinants of oil-dependent development starting with the impressive growth and emerging democracy of the post war period, economic stagnation of the 1980's and 1990's, and the divisive contemporary era of 'Chavismo'. To deconstruct the thesis that oil and development do not mix, each chapter explores the dynamic connections between the fiscal structure of the Venezuelan state, institutionalized patterns of political conflict and compromise, and their socio-economic consequences. It is argued that such a multi-faceted approach moves beyond static interpretations of the resource curse to grasp more firmly the ever-changing resource relationship.

  14. Onchocerciasis endemic in the State of Bolivar, Venezuela.

    PubMed

    Godoy, G A; Volcan, G S; Medrano, C; Guevara, R

    1989-08-01

    Microfilariae of Onchocerca volvulus were demonstrated by single shoulder-skin biopsy in 42.8% of inhabitants of seven Amerindian villages in an area of approximately 10,000 km2, near the Brasilian Roraima Territory. The highest prevalence was found among the Yanomama Indians of Chajuraña (84.6%, with a mean of 61.3 microfilariae per mg of skin). The six other communities were affected, but with lower prevalence and microfilaria skin densities. The absence of lymphoedema and the few subcutaneous nodules and eye lesions found among the infected individuals suggest a relatively recent introduction of the disease to the region. Mansonella ozzardi infections were also detected in the area. PMID:2604478

  15. Lagochilascaris minor infection in Venezuela. Report of a case.

    PubMed

    Volcan, G S; Ochoa, F R; Medrano, C E; de Valera, Y

    1982-11-01

    A Lagochilascaris minor infection in a 6-year-old Venezuelan girl with a 4-year history of nasal obstruction is reported. Treatment with levamisole resulted in clinical and radiological cure. Eggs of L. minor were observed in the patient's feces; these were cultured to second stage larvae. PMID:6890772

  16. version 25Apr11b From Saudi Arabia to Venezuela

    E-print Network

    O'Donnell, Tom

    Plan/Grading Rubric ­ Readings presentations and participation, 50 points - - 50% Research paper/Science/Economics | Class #28147 | 5 Undergrad credit hours | Spring Quarter 2011 Friday 12:00 ­ 2:48 | Room 125 Mendenhall Laboratory Instructor: Thomas W. O'Donnell ­ twod@umich.edu URL: http://TomOD.com Student Research Group

  17. Mud volcanoes of the Orinoco Delta, Eastern Venezuela

    USGS Publications Warehouse

    Aslan, A.; Warne, A.G.; White, W.A.; Guevara, E.H.; Smyth, R.C.; Raney, J.A.; Gibeaut, J.C.

    2001-01-01

    Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins. ?? 2001 Elsevier Science B.V. All rights reserved.

  18. Late quaternary evolution of the Orinoco Delta, Venezuela

    USGS Publications Warehouse

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

    2002-01-01

    The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel from incising as deeply as many other major river systems. Shallow seismic data indicate that the late Pleistocene Orinoco incised into the present continental shelf, where it formed a braided-river complex that transported sediment to a series of shelf-edge deltas. As sea level rose from 16,000 to 9,500 yrs BP, the Orinoco shoreline shifted rapidly landward, causing shallow-marine waves and currents to form a widespread transgressive sand unit. Decelerating sea-level rise and a warmer, wetter climate during the early Holocene (9,500 to 6,000 yrs BP) induced delta development within the relatively quiet-water environment of the EVB embayment. Sea level approached its present stand in the middle Holocene (6,000 to 3,000 yrs BP), and the Orinoco coast prograded, broadening the delta plain and infilling the EVB embayment. Significant quantities of Amazon sediment began to be transported to the Orinoco coast by littoral currents. Continued progradation in the late Holocene caused the constriction at Boca de Serpientes to alter nearshore and shelf hydrodynamics and subdivide the submarine delta into two distinct areas: the Atlantic shelf and the Gulf of Paria. The increased influence of littoral currents along the coast promoted mudcape development. Because most of the water and sediment were transported across the delta plain through the Rio Grande distributary in the southern delta, much of the central and northwestern delta plain became sediment starved, promoting widespread accumulation of peat deposits. Human impacts on the delta are mostly associated with the Volca??n Dam on Can??o Manamo. However, human activities have had relatively little effect on the delta processes and environments.

  19. An investigation of rainfall variability and distribution in Venezuela

    E-print Network

    Gibson, Donald Reid

    1968-01-01

    possible causes of rainfall in these regions. The rainfall regime f' or each month was dif'ferent and the synoptic cause of rai. nfall in each area seemed to differ. The rainfall regime in the Interior Grasslands occurred in the spring and summer... amounts. In Year 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 10 20 TOCUYO DH LA COSTA (Method I) Pentad Number 30 40 50 60 70 75 Avera e 17. 7 rai~n entads er...

  20. Study of the seismic attenuation generated by the mud layer in Lake Maracaibo, Venezuela 

    E-print Network

    Perez Arredondo, Javier Antonio

    2004-09-30

    39a14a18a35a42a17a43a26a33a40a44a23a34a45a28a14a46a20a21a23a47a35a34a23a47a22a48a23a47a17a49a36a50a9a39a51a53a52a39a14a27a26a28a14a29a54a55a3a34a14a27a40a44a23 a56a21a57a59a58a61a60a43a62a64a63a65a62 a66a68a67 a69 a56a53a70a18a71a73a72a55a74a75a56a18a...76a77a57a77a78a25a76a77a71a79a78a11a80a55a72a55a74a81a72a44a82a83a56a84a74a81a74a77a72a55a85a25a78a27a76a84a85a25a78 a86a88a87 a66a61a89 a63a91a90a64a90a92a60a43a93a34a90a95a94a8a90a95a58a61a60a4a78a84a96a50a97a49a60a25a94a99a98a101a100a27a102a92a103a...

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

    E-print Network

    Williams, John David

    1995-01-01

    to 70 cin total length, they are found throughout the Guyanas, and the Amazon, Orinoco, and Paraguay river basins (Gdry 1977). Little in-depth study has been conducted on the ecology and life history of this species. Plagioscion squamosissimus from.... 1986). For example, dams have been shown to block the migratory paths of large catfishes in the Amazon basin, and their population densities have declined (Barthem et al. 1991). In Oklahoma, the building of the Altus Dam on the Red River caused...

  2. Structural synthesis and tectonic evolution of the Maracaibo and Barinas-Apure basins, Western Venezuela

    SciTech Connect

    De Toni, B.; Loureiro, D. [Intevep, S.A., Caracas (Venezuela); Colletta, B.; Rourke, F. [I.F.P., Paris (France)

    1996-08-01

    Seismic profiles have imaged the complex and multiphase geometry of major structures in the Maracaibo and Barinas-Apure basins and foothills of the adjacent orogens. Pre-Mesozoic structuring can be documented in subsurface as a peneplaned south-southeast vergent fold-thrust-belt of Hercynian or Caledonian age. In Jurassic times, rifting developed in connection with the opening of western Tethys and thick continental red beds were deposited in the rift grabens. In Late Cretaceous times, postrift thermal subsidence was subsequently recorded. From Maastrichtian through Eocene times, the obduction of the Tethyan ophiolites and the coeval tectonic accretion of the Caribbean allocthon loaded the South American foreland lithosphere, inducing the development of a flexural basin in the northeastern part of the Maracaibo basin. In Late Eocene and Oligocene times, a major extensional event took place in the East Zulia and Falcon area soon after the Caribbean compressional deformation ceased. Since the Neogene, structuring was related to the Andean orogeny, and the deformation was partially superimposed onto older Paleogene and Jurassic structures. These results, integrated with geochemical and chronostratigraphic models, have been used to understand the evolution of the petroleum system and to improve the play fairway risk assessment for exploration.

  3. Microbial activity in surface sediments of Chacopata-Bocaripo lagoon axis, Sucre State, Venezuela.

    PubMed

    Segnini de B, Mary Isabel; Gómez, Irma; Brito, Leonor; Acosta, Vanessa; Troccoli, Luis

    2015-02-28

    The aim of this work was to evaluate the microbial activity of the surface sediments (0-10 cm) of the Chacopata-Bocaripo lagoon axis (Ch-BLA) through microbiological parameters: microbial biomass (Cmic) dehydrogenase activity (DHS), fluorescein diacetate hydrolysis (HFDA), arginine ammonification (AA) and biochemical parameters: phosphatase (PHa) and urease (URa) activity. They were determined during transition (July 2010) and upwelling (March 2011) periods. Total organic carbon (TOC) did not vary significantly (p?0.05) between climatic periods. All the parameters studied were higher in upwelling season: Cmic (191.79 mg Cmic kg(-1)), DHS (228.70 ?g TFF g(-1) 24 h(-1)), HFDA (204.09 ?g fluorescein g(-1) 24 h(-1)), AA (13.09 ?g NH4-N g(-1) h(-1)), PHa (132.31 ?g pNF g(-1) h(-1)), URa (12.90 ?g NH4-N g(-1) h(-1)). They appear to be controlled by the availability and quality of nutrients in each climatic period, and were useful tools for evaluating changes in microbial activity in marine sediments. PMID:25455789

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

    E-print Network

    random amplified polymorphic DNA (RAPD) primers. Thir- teen P. falciparum stocks from Kenya and four evidence: (i) sex is an obligatory event for the life cycle of the parasite to be completed, (ii) genetic

  5. Blood metabolites and their relationship with production variables in dual-purpose cows in Venezuela.

    PubMed

    Parra, O; Ojeda, A; Combellas, J; Gabaldon, L; Escobar, A; Martinez, N; Benezra, M

    1999-01-27

    A survey was carried out on 79 lactating Bos taurus/indicus cross-bred cows on three dual-purpose cattle farms to measure the blood concentration of metabolites and to evaluate possible relationships with nutritional status and productive variables. A rotational grazing system on Star grass and other tropical pastures (10-12% CP in leaves) was used and 2-3 kg/cow/day of concentrate were fed on two farms. Restricted calf suckling was used in two herds. Average milk yield sold per farm was 6 kg/day/cow and body condition scores (BCS) were between 3.0 and 3.8 on a scale of one-to-five. On two farms, the average interval from calving to conception (ICC) was more than 145 days. Mean blood concentrations of albumin, globulin, urea, beta-hydroxybutyrate and phosphorus were generally within reference values, but a significant group of cows had low levels of albumin and urea and high levels of globulin. Packed cell volume (PCV) was below normal values, with anemia in 63% of cows during the second trimester of lactation, which was negatively correlated to milk yield. The high incidence of anemia could be related to factors such as hematophagic parasites, not evaluated in this study. ICC values were negatively related to albumin level and could be associated with protein deficiency in the diet or with disease, as globulin values were high in many cows. Based on these diagnoses, an experiment was carried out on one of the farms to evaluate the influence of supplementation with 0.5 kg/cow/day of fish meal. Total milk yield was not influenced by the fish meal and reproductive efficiency was high in the two supplemental treatments. It was shown that supplementation with undergraded protein is not required in these cows. PMID:10081793

  6. Regional controls on geomorphology, hydrology, and ecosystem integrity in the Orinoco Delta, Venezuela

    Microsoft Academic Search

    Andrew G. Warne; Robert H. Meade; William A. White; Edgar H. Guevara; James Gibeaut; Rebecca C. Smyth; Andres Aslan; Thomas Tremblay

    2002-01-01

    Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km2 Orinoco delta plain support diverse fresh and brackish water ecosystems. To develop environmental baseline information for this largely unpopulated region, we evaluate major coastal plain, shallow marine, and river systems of northeastern South America, which serves to identify principal sources and controls of water and sediment flow into,

  7. Spaceborne radar (ERS-1 and RADARSAT-1) tests for hydrocarbon exploration in Venezuela

    SciTech Connect

    Chigne, N.; Dekker, F. [Dekker Remote Sensing Corp., Calgary (Canada); Nazarenko, D.; Duncan, R.G.; Welgan, P. [Radarsat International, Inc., Vancouver (Canada)] [and others

    1996-08-01

    Satellite radar images were analyzed in conjunction with various complementary data sets to evaluate their potential in the hydrocarbon exploration process. The first phase of the project took place in 1994 within the Barinas-Apure Basin where ERS-1 data was integrated with Landsat TM, airborne radar, geophysical and geological data. Since its launch in 1995, additional RADARSAT data has been acquired to compare image characteristics of the European and Canadian satellites. In addition, a second phase involving the detailed evaluation of various RADARSAT imaging modes has been conducted in a more southern Merida Andes test site. Both study areas have been actively explored for hydrocarbons throughout the last half century. However, geological interpretation has been hampered by cloud cover, abundant vegetation and inhospitable terrain. The satellite radar imagery provided the first continuous view of these study areas and revealed geologic structures not clearly identified before. Although satellite radar is subject to geometric distortion, the imagery can reveal the relative position of geological features as it relates to geography and topography. This was proven as the true geographic position of the Bocono fault was clearly defined within the radar imagery of the first test site, disproving the previously accepted positions. The position of this fault had traditionally been erroneously defined due to the noncontinuous data sets which were relied upon.

  8. EPIDEMIOLOGY OF BOVINE LEUKEMIA IN VENEZUELA C. MARN NANCY M. DE LPEZ LUISA ALVAREZ O. LOZANO

    E-print Network

    Paris-Sud XI, Université de

    -diffusion en gel d'agar (I.D.1, en utilisant un antig6ne GP60, dans le but de determiner 1'extension de I in agar test (AID) with GP 60 antigen (7), serologic assays where made on 18,000 animals grouped), cytomorphological evaluation of blood and lymph node smears. Results and discussion. The investigations that were

  9. Study of the seismic attenuation generated by the mud layer in Lake Maracaibo, Venezuela

    E-print Network

    Perez Arredondo, Javier Antonio

    2004-09-30

    67 a62a95a60a49a93a61a63 a89 a60a43a114a68a90a140a148a217a197a29a197 a182 a177 a107a88a63 a40a55a17a19a0a2a1a192a9a31a10a181a10a124a17a30a32a34a3a34a35a47a14a4a0 a131a158a71a79a100a25a112a84a74a77a72 a80a158a103a104a129a117a60 a133 a148 a176 a132 a94...a0a2a1a4a3a6a5a8a7 a9a8a10a11a1a13a12a6a14a15a0a16a14a18a17a19a0a16a20a21a17a19a22a24a23a25a1a4a1a4a14a27a26a28a3a6a23a25a1a29a17a30a9a31a26a33a32a34a14a27a26a6a14a18a35a34a23a25a1a4a14a18a5a37a36a13a7a38a1a4a12a28a14 a20a21a3a39a5a38a40a41a23a18a7a...

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

    E-print Network

    Maier, Crystal A.

    2013-09-05

    –91 (2013) doi: 10.3897/zookeys.329.4961 www.zookeys.org Copyright Crystal A. Maier. This is an open access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC-BY), which permits unrestricted use, distribution... in pen and ink using a camera lucida attached to the compound microscope and scanned into the computer. Images were edited in Adobe® Illustrator® and Adobe® Photoshop®. Label information in the material examined is quoted exactly from the original...

  11. New species of Metatrichia Coquillett (Diptera: Scenopinidae) from Australia and Venezuela

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new species of the cosmopolitan genus Metatrichia Coquillett are described. Metatrichia dhimurru sp. nov. is described from Arnhem Land (Northern Territory), Australia and represents the third species of the genus to be described from the Australian-Papuan region. Metatrichia venezuelensis sp. n...

  12. Trench investigation along the Merida section of the Bocono fault (central Venezuelan Andes), Venezuela

    USGS Publications Warehouse

    Audemard, F.; Pantosti, D.; Machette, M.; Costa, C.; Okumura, K.; Cowan, H.; Diederix, H.; Ferrer, C.

    1999-01-01

    The Bocono fault is a major NE-SW-trending, dextral fault that extends for about 500 km along the backbone of the Venezuelan Andes. Several large historical earthquakes in this region have been attributed to the Bocono fault, and some of these have been recently associated with specific parts through paleoseismologic investigations. A new trench study has been performed, 60 km to the northeast of Merida in the central Venezuelan Andes, where the fault forms a releasing bend, comprising two conspicuous late Holocene fault strands that are about 1 km apart. The southern and northern strands carry about 70% and 30% (respectively) of the 7-10 mm/yr net slip rate measured in this sector, which is based on a 40 vs. 85-100 m right-lateral offset of the Late Pleistocene Los Zerpa moraines. A trench excavated on the northern strand of the fault (near Morros de los Hoyos, slightly northeast of Apartaderos) across a twin shutter ridge and related sag pond exposed two main fault zones cutting Late Pleistocene alluvial and Holocene peat deposits. Each zone forms a shutter ridge with peat deposits ponded against the uplifted block. The paleoearthquake reconstruction derived from this trench allow us to propose the occurrence of at least 6-8 earthquakes in the past 9000 yr, yielding a maximum average recurrence interval of about 1100-1500 yr. Based on the northern strands average slip rate (2.6 mm/yr), such as earthquake sequence should have accommodated about 23 m of slip since 9 ka, suggesting that the maximum slip per event ranges between 3 and 4 m. No direct evidence for the large 1812 earthquake has been found in the trench, although this earthquake may have ruptured this section of the fault. Further paleoseismic studies will investigate the possibility that this event occurred in the Bocono fault, but ruptured mainly its southern strand in this region.

  13. Chemical composition of the essential oil of Gynoxys meridana from Mérida, Venezuela.

    PubMed

    Hernández, Johanna; Rojas-Fermin, Luis B; Amaro-Luis, Juan; Pouységu, Laurent; Quideau, Stéphane; Usubillaga, Alfredo

    2015-04-01

    The volatile components from the fresh leaves of Gynoxys meridana Cuatrec. were obtained by hydrodistillation and analyzed by GC/MS. A total of 25 compounds, representing 99.3% of the oil, were identified. The dominant compounds were ?-curcumene (31.9%), fukinanolide (22.3%), ?-pinene (9.5%), ?-phellandrene (7.1%) and ?-pinene (5.7%). PMID:25973501

  14. An applied sequence stratigraphic approach in reservoirs characterization, Eastern Venezuela: El Carito-El Furrial Fields

    SciTech Connect

    Sifontes de, R.; Hernandez, E. (Intevep S.A., Caracas (Venezuela))

    1993-02-01

    Integration of biostratigraphic, sedimentologic and petrophysic data from cores and well logs in reservoirs in El Carito-El Furrial Fields, Northern Monagas, Eastern Venezuelan Basin, allows to differentiate two sedimentary sequences ranging between the Upper Cretaceous and the Oligocene. The Maastrichtian-Paleocene sequence is divided into two sedimentary units (C and 1) both representing a south to north progradation from shallow marine to fluvial environments, within a large regressive cycle. The Middle Eocene to Middle-Late Oligocene sequence includes sedimentary units II and III. Unit II represents a large transgressive cycle of mostly inner neritic deposits with a condensed section at the base which changes laterally from glauconitic to lutitic facies to the south. Unit III grades transitionally from the inner neritic deposits of unit II to shallow marine deposits, and changes to inner neritic deposits again to the top. Unit III is interpreted as a large regressive -transgressive cycle. In all these sedimentary units, lithofacies association, paleoenvironments variation and definition of large cycles helped to define the parasequence stacking sets. The petrographic analysis points out that sandstones in unit C are basically subarcosic, while in units I, I and III are quartzitic. Additionally, sandstones in units C and II are very cemented by quartz and carbonates respectively, showing chemical compaction, in contrast to units I and III where quartz dissolution is a porosity enhancing process. This indicates that sandstones in these units have the best porosity and permeability values, resulting in the best producing intervals in the study area.

  15. Late Cretaceous and Mid-Tertiary palynology assemblages from the 'El Furrial' area wells, Venezuela

    SciTech Connect

    Fasola, A.; Paredes, I. (INTEVEP, S.A., Caracas (Venezuela))

    1991-03-01

    The Maturin subbasin, located within the Eastern Venezuelan basin and where the 'El Furrial' field was discovered, has been the subject of great exploration interest, since large amounts of oil were found in the last decade. This paper is part of a multidisciplinary effort to better understand the geology of the area. From the late part of the Paleogene onward, this subbasin developed as a foreland type basin, flanked to the north by a mountain belt: the Serrania del Interior. The stratigraphic nomenclature previously established in the Serrania del Interior was used in subsurface studies, but sometimes with unsuccessful results. An attempt is made in this paper to clarify in part the nomenclature since the biostratigraphic point of view sees the ages determined in subsurface not completely agreeing with those established for the surface formations. The palynological studies carried out on well samples from the 'El Furrial' field have shown the presence of a Late Cretaceous sequence with terrestrial pollen and spores assemblages, and marine microplankton, through which the sequence was dated as Early to Middle Maastrichtian. Toward the top, the sequence contains paleosols, and the palynomorphs are scarce and nondeterminant. The paleoenvironments vary from marine nearshore to subaereal in the Cretaceous. Immediately after a glauconitic section was deposited the first Tertiary (Oligocene) palynomorphs and foraminifers appear, thus showing an important time gap not completely determined as yet. The paleoenvironments suggested for this Tertiary sequence are marine, probably of the shelf of the neritic zone.

  16. Tectono-stratigraphic evolution of the Eastern Maturin Foreland basin (Eastern Venezuela)

    SciTech Connect

    Azavache, A.; Flinch, J.; Giffuni, G.; Martinez, R. [Eastern Maturin Team, Caracas (Venezuela)] [and others

    1996-08-01

    The Eastern Venezuelan Basin is a classical foreland basin related to the loading of the Serrania del Interior thrust-sheets. The flexure of the basin started during Upper Oligocene-Lower Miocene time and is evidenced by a major unconformity between the Cretaceous and the Lower Miocene Oficina Formation (Basal Foredeep Unconformity). The sedimentary-filling of the Basin commences with coastal transgressive sandstones of the Oficina Formation (Lower Miocene) that constitute the main reservoir of this petroleum province. The overlying deposits of the basin can be subdivided into: (1) Deep-water stage represented by the upper Oficina shales and the Freites Formation in the south and the Carapita Formation in the north (Middle Miocene). This shale interval constitutes the main seal of the region. This stage is characterized by major onlap and a major flooding surface. (2) Progradational stage characterized by shelf-slope deposits of the Lower-Middle La Pica Formation (Upper Miocene). Siliciclastic shelf wedges consisting of deltaic facies. (3) Aggradational stage fluvial-alluvial delta plain deposits represented by the Upper La Pica, Mesa and Las Piedras Formations (Pliocene-Pleistocene). In the northern part of the basin, southward-vergent thrusting deformed the basement and its thin Cretaceous-Lower Miocene cover. South of the Rio Tigre area compressional structures are combined with normal faults related to flexural extension. The boundary between basement-involved thrusting and flexural extension controls the type of structural traps within the basin.

  17. Geochemical modelling of the principal source rocks of the Barinas and Maracaibo basins, western Venezuela

    SciTech Connect

    Tocco, R.; Gallango, O. [Intevep, Caracas (Venezuela); Parnaud, F. [Beicip Franlab, Rueil Malmaison (France)

    1996-08-01

    This study presents a geochemical modelling of the principal source rocks in the western Venezuelan Basins. The area covers more than 100,000 km{sup 2}, and includes Lake Maracaibo and Barinas Basins. The geochemical modelling recognizes three source rocks: (1) A principal, K3-K4-K5 Cretaceous sequences, represented by La Luna, Capacho and Navay formations, (2) a secondary, corresponding to the T4 Oligocene sequence, represent by the Carbonera Formation, and (3) an accessory source rock, K7-K8 Paleocene sequences, represented by the carbonaceous shales and coals of the Orocue Group and Marcelina Formation. Three periods of hydrocarbon expulsion were defined for La Luna Formation (Early Eocene-Late Eocene, Middle Miocene-Early Miocene and Early Miocene-Holocene) and a principal period of hydrocarbon expulsion for Orocue Group and Carbonera Formation (Plio-Pleistocene and Middle Miocene Plio-Pleistocene). The 90% of hydrocarbons generated correspond to the principal source rock La Luna Formation, and the 10% to Tertiary source rocks (Carbonera Formation and Orocue Group). Five petroleum systems were identified: Lake Maracaibo, southwest of the Lake Maracaibo Basin, the Lara nappes, the extensive basins of eastern Zulia and the Barinas subbasin.

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

    E-print Network

    Medina Tarrazzi, Trina Mercedes

    2003-01-01

    3. 30 3. 31 3. 32 3. 33 3. 34 3. 35 3. 36 3. 37 4. 1 Page Log-log Plot of Shut-in Pseudopressure Functions versus Shut-in Pseudotime- Santa Barbara Field, Well TM-32L, Shut-in 3 [Test Date: 01... Nor(cub( formation. The analyses for the other wells can be found in Appendix A. Well: TM-1E Wea Tn-15/porusay nlslrlbuaon with Depth (Upper Narlcual) Well Tost Wpenneebaay nlstrlbuaon ?0th Depth (Upper Nancual) 15100 ~ d4 ~ ~ ss ~ ~ ~ ae...

  19. Aluminum accumulation and its relationship with mineral plant nutrients in 12 pteridophytes from Venezuela

    Microsoft Academic Search

    Elizabeth Olivares; Eder Peña; Eunice Marcano; Julián Mostacero; Guillermina Aguiar; Malfy Benítez; Elizabeth Rengifo

    2009-01-01

    The purpose of this study was to investigate the aluminum (Al) concentration in Lycopodium clavatum, Dicranopteris flexuosa, Sticherus nudus, Anemia villosa, Cyathea gibbosa, Pteridium arachnoideum, Pteris vittata, Thelypteris dentata, Blechnum occidentale, Elaphoglossum sporadolepis, Nephrolepis cordifolia and Polypodium pseudoaureum, species from 11 families with different phylogenetic position, found on soils with a high concentration of Al (up to 13gkg?1dry mass (DM)).

  20. Data from sediment studies of the Rio Orinoco, Venezuela, August 15-25, 1982

    USGS Publications Warehouse

    Nordin, Carl F.; Meade, R.H.; Curtis, C.C.

    1983-01-01

    Water and suspended-sediment discharges were measured and bed-material samples were collected during August, 1982, at 9 cross sections along a 800-kilometer reach of the Rio Orinoco. Flows varied from approximately 31,000 to 72,000 cubic meters per second, and sediment discharge varied from approximately 1,600 to 8,000 kilograms per second. The bed material is mostly fine to medium sand and almost one-third of the suspended sediment is sand.

  1. Do Domestic Firms Benefit from Direct Foreign Investment? Evidence from Venezuela

    Microsoft Academic Search

    Brian J. Aitken; Ann E. Harrison

    1999-01-01

    Governments often promote inward foreign investment to encourage technology 'spillovers' from foreign to domestic firms. Using panel data on Venezuelan plants, the authors find that foreign equity participation is positively correlated with plant productivity (the 'own-plant' effect), but this relationship is only robust for small enterprises. They then test for spillovers from joint ventures to plants with no foreign investment.

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

    E-print Network

    Niu, Fenglin

    ). The Moho-discontinuity is extremely flat and sharp with a large velocity and density contrast which's ratio. Estimated Moho depth ranges from $16 km beneath the southeastern Caribbean Sea to $52 km beneath

  3. Decentralisation and Regionalisation in Educational Administration: Comparisons of Venezuela, Colombia and Spain.

    ERIC Educational Resources Information Center

    Hanson, E. Mark

    1989-01-01

    Compares administrative reforms and decentralization in the public educational systems of 3 Hispanic countries 10 years after transition to democracy. Discusses the effects of collaboration and compromise among political parties, incremental approaches to change, continuity of policies, costs and resource management, and formalization of…

  4. Characterization of Habitat for Hawksbill Turtle (Eretmochelys imbricata) in Los Roques Archipelago National Park, Venezuela 

    E-print Network

    Hunt, Luciana E.

    2010-10-12

    , primarily for its carapace scutes (tortoiseshell or bekko), the hawksbill turtle, Eretmochelys imbricata, is considered critically endangered throughout its range (Baillie & Groombridge 1996, Hilton-Taylor & Mittermeier 2000, Mortimer & Donnelly 2008... endangered ecosystems on the planet (Wilkinson 2000), successful conservation and management of hawksbills may be an important contributor to coral reef ecosystem restoration (Spotila 2004, Mortimer et al. 2007). Studies of sea turtle population trends...

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

    E-print Network

    McGuire, Tamara Lee

    1995-01-01

    The Cinaruco Fishing Club Aniello Barbarino-Duque The Marzuola Family Hector Gonzalez Fernando Rosales of Toucan Lodge Dr. Donald Taphom Dr. Kirk Winemiller Aseomuseol UNELLEZ The Garcia family Marie and Tex Chandler For field assistance: David... Winemiller Dr. Donald Taphorn Anielo Barbarino-Duque For constant encouragement, enthusiasm, and patience: David Jepsen Dr. Kirk Winemiller Alphonse Adite Dr. Mary Silver (University of California at Santa Cruz) last but not least, my family- the Mc...

  6. Facies control on oil producing, naturally fractured reservoirs, a cast study: Block I, Lake Maracaibo, Venezuela

    SciTech Connect

    Rodriguez, A.; Marquez, X.

    1988-02-01

    In Block I, Lake Maracaibo, oil producing intervals in the Cretaceous have been found to be facies controlled. Detailed studies of the cored sections in various wells have shown that facies Ls2, characterized by an oolitic grainstone, is the main producing reservoir. This facies has been interpreted as deposited as an oolitic shoal in a shallowing-upward sequence. Other facies such as Ls1, represented by a bioclastic rudstone, and Ls, composed of a mudstone, are also present but do not show significant oil production. The presence of subvertical, open, hairline fractures and centimeter-scaled wide, bridged fractures in facies Ls2 can explain its great producing capacity, while the presence of calcite mineralized fractures in Ls1 and absence of fractures in Ls account for the poor producing capability of these facies. In contrast to what has been reported in other case studies, the grainstone facies shows the most fracture density and open fractures. A facies model which predicts the lateral continuity of the facies present in Block I is proposed as a tool for oil exploration and exploitation for this area and other areas with similar sedimentological characteristics.

  7. Eocene tectonic controls on reservoir distribution in VLE 196, Block V, Lamar Field, Maracaibo Basin, Venezuela 

    E-print Network

    Choi, Byeonggoo

    2006-10-30

    of the Maracaibo basin The Eocene sediments in the Maracaibo basin were deposited in the foreland basin, according to the deposit of wedge shape geomorphology and orogenic belts. DeCelles and Giles (1996) suggested a new term of a foreland basin system... peripheral or retroarc fold-thrust belt.? This definition implies an accommodation of three types of tectonic loads, such as; 1) orogenic load by continent-continent collision (e.g., Himalaya); 2) subduction load by continental and oceanic collision...

  8. [Soil-vegetation relationships in a toposequence of the Guayana Shield, Venezuela].

    PubMed

    Lozada, José Rafael; Soriano, Pilar; Costa, Manuel

    2014-03-01

    The Guayana Shield is one of the oldest territories in the planet and has millions of years subjected to leaching and erosion processes that produce oligotrophic soils. This scarcity of nutrients has not avoided the development of high, diverse and magnificent forests, where plants have adaptations to survive these difficult conditions. The aim of this work was to characterize the physical and chemical parameters of the soils in different forest communities of the Imataca Forest Reserve (IFR), to establish some interpretations on their origin, and some relationships between the edaphic components and the inhabitant species. Terrestrial journeys were carried out and two pathways were traced for the interpretation of forest communities. In each community, three plots (100m x 100m) for the ecological survey were established. In each plot, all trees, palms, and lianas were measured (dbh> or =10cm; dbh: diameter at breast height); four 10m x 10m understory sub-plots were evaluated, and a census of all the spermatophyta species (dbh< 10cm) was made. Soils were evaluated by means of a trial pit in each community, and a bore in each one understory sub-plot. The obtained data were analyzed by both a detrended and a canonical correspondence analysis. Results from a total of 15 plots allowed us to identify three communities: a forest dominated by Mora excelsa located in a narrow valley with high content of silt; a swamp forest dominated by Catostemma commune in a sandy broad valley, and a forest in clay hills dominated by Alexa imperatricis. Most of the soils had a pH between 3.1 and 4.5. Nutrients were in very low concentrations (N: 0-0.2%; P: 0-14ppm; K: 0-0.3 Cmol/kg) and A1 in toxicity quantities. We observed that Ca/A1 relationship greater than 1 meant a neutralization of the toxic effect of Al. Besides, basal area ranged from 20.4 to 32.3m2/ha; the highest level (top local forest development) corresponded with the C. commune community with a Ca/A1 value of 2.5. This research found an adequate relationship between soil and vegetation, as it was able to identify three communities into three distinct soil conditions. Nevertheless, edaphic constraints indicated that high forest cover must be maintained as an essential element for the conservation of these communities. PMID:24912367

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

    E-print Network

    Williams, John David

    1995-01-01

    species: Hemi g rammus mt cropterus =80. 2%, Curl matella i mmaculata =3. 5%, Bryconops caudamaculatus=2. 1%, Hemigrammus rodwayi=1. 6%, Hemlodopsis gracilis=1. 4%, and Mesonauta festivus=1. 2%) (Figure 4). In Itaipu Reservoir, Brazil, a similar fish... fasciatus Leporinus fasciatus Leporinus friderici Leporinus maculatus Hemi odopsis semi teniatus Hemiodopsis goeldii Hemiodopsis gracilis Hemiodopsis quadrimaculatus Hemiodus unimaculatus Curimatella immaculate Curimatopsis macrolepis Prochilodus...

  10. Sedimentary structures and textures of Rio Orinoco channel sands, Venezuela and Colombia

    USGS Publications Warehouse

    McKee, Edwin Dinwiddie

    1989-01-01

    Most sedimentary structures represented in sand bodies of the Rio Orinoco are tabular-planar cross-strata which, together with some wedge-planar cross-strata, are the products of sand-wave deposition. Locally, in areas of river meander where point bars characteristically form, trough structures forming festoon patterns are numerous. At a few localities, sets of nearly horizontal strata occur between tabular-planar sets and are interpreted to be the deposits of very fast currents of the upper flow regime; elsewhere, uncommon lenses and beds of silt, clay, or organic matter consisting of leaves and twigs, seem to be the result of quiet-water settling through gravity. By far the most common grain size represented in the tabular-planar and wedge-planar cross-strata of the sandwave deposits is medium sand (? - ? millimeter) as determined by screen analyses. Many samples, however, also contain moderate quantities of coarse or very coarse sand. Eolian dunes on top of the sand-wave deposits are dominantly fine grained. The river channel sands were determined to be largely moderately well sorted, although in some places they were mostly well sorted, and in others, mostly moderately sorted.

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

    E-print Network

    Vásquez, Carlos

    ­ administrativo, que inciden en forma determinante en los procesos y actividades que contempla el Reglamento constitucional, a los fines de consagrar en el citado Reglamento, la garantía al debido proceso y el derecho a la

  12. Lipid composition and vertical distribution of bacteria in aerobic sediments of the Venezuela Basin

    NASA Astrophysics Data System (ADS)

    Harvey, H. Rodger; Richardson, Michael D.; Patton, John S.

    1984-04-01

    Box cores of surface (0 to 30-cm) sediments from carbonate, hemipelagic, and turbidite sediment types of the deep (3493 to 5039-m) Venezuelan Basin were analyzed to investigate the relationship between the vertical distribution of bacteria, lipids, lipid phosphate, and grain size. The polar lipid fraction was isolated chromatographically and quantified by flame-ionization detection using the Iatroscan TH-10 analyzer. Total bacterial abundance was measured by epifluorescence microscopy in sediments (0 to 20-cm) from the carbonate and turbidite sediments. In all three sediment types investigated, both total and polar lipid concentrations decreased with increasing depth in the sediment. The highest total and polar lipid concentrations were at the sediment-water interface (0 to 2-cm) of hemipelagic sediments (62.0 and 25.7 ?g g -1 dry sediment, respectively) followed by the carbonate and turbidite sediments. A similar decline in lipid phosphate was also observed. Bacterial abundance was > 5 × 10 8 bacteria (per gram dry sediment) at the sediment surface in both sediments examined and over 1 × 10 7 bacteria 20 cm below the sediment-water interface. Polar lipid and lipid phosphate concentrations did not appear to correlate with estimates of bacterial biomass, even in regions where bacteria were apparently the only organisms present.

  13. LA ASAMBLEA NACIONAL DE LA REPBLICA BOLIVARIANA DE VENEZUELA la siguiente,

    E-print Network

    Vásquez, Carlos

    organismos del sector privado, empresas, proveedores de servicios, insumos y bienes de capital, redes de promover los programas de formación de talento humano necesarios para el desarrollo científico y

  14. Drivers of internationalisation of companies from emerging economies: comparing Petrobras (Brazil) and PDVSA (Venezuela)

    Microsoft Academic Search

    Andrea Goldstein; Cesar Baena

    2010-01-01

    The history of the global oil industry is essential to understand the rise of multinational enterprises. Petrobras, in particular, has started to exploit in international markets the world-class technology it developed to exploit deepwater oil fields. PDVSA, on the other hand, has focused its international expansion strategy in building a network of refineries in key consuming markets. This paper examines

  15. Hydrocarbon generation potential of the Cretaceous section from Well ALP-6, Perija Region, Venezuela

    SciTech Connect

    Pratt, L. (Indiana Univ., Bloomington, IN (United States)); Mompart, L.; Murat, B. (Maraven S.A., Caracas (Venezuela))

    1993-02-01

    Geochemistry and sedimentology have been integrated in order to provide a better understanding of the source rock potential and depositional environments of the La Luna Formation and Machiques Member in Well ALP-6 (Perija region). These two units, the dominant source rocks in the Maracaibo Basin, are mainly shales with high to very high organic content, while thin interbeds of limestones are poor in organic matter. A detailed sedimentological study and sequence analysis indicates that both shaly units represent a period of platform infilling subsequent to drowning. Periods of progressive back stepping culminating in the deposition of organic-rich condensed intervals are recognized, based on sedimentology of cores and wireline log analysis. A succession of fining-upward sequences, 1' to 5' thick, with distinct sedimentological and geochemical signatures have been identified in the La Luna Formation. Phenomena of early diagenesis (intrashale calcite growth due to organic matter degradation; sulfur precipitated in local paleolows) to late diagenesis (pressure-solution effects with development of laterally correlatable cone-in-cone layers) are all indicators that the hydrocarbon generation potential of La Luna is not uniform and can only be assessed by detailed geological, sedimentological and geochemical investigations. Two geochemically distinct facies can be identified in both La Luna and Machiques. A sulfur-rich facies is characterized by Corg/AVSul ratios averaging 1.9 and by exceptionally high concentrations of sulfur-bearing aromatic compounds. A sulfur-poor facies is characterized by Corg/AVSul ratios averaging 9.2 and by trace concentrations or absence of sulfur-bearing aromatic compounds.

  16. Estimation of oil recovery by in-situ combustion in the Jobo Field of Eastern Venezuela

    SciTech Connect

    Luengo-C, J.R.; Sanyal, S.K.

    1981-03-01

    A laboratory combustion experiment using samples from Jobo Field was completed. The data obtained by this experiment could be used for an approximate estimation of recovery for a pilot project in this field. An isolated pilot test would give enough information to determine the behavior of the combustion process for field applications. Aplication of recovery correlations indicate that a pilot test in an inverted 5-spot pattern (10 to 20 acres spacing) appears adequate for these field conditions. Air injection rates should be calculated and compared with injectivity tests, the ability of the producing wells to handle the oil, and the maximum pressure the reservoir can handle without fracturing.

  17. Inauguracin del portal "Venezuela" de la Biblioteca Virtual Alicante, 15 de noviembre de 2001

    E-print Network

    Escolano, Francisco

    necesidades". Sus maestros de Caracas, y luego compañeros en sus viajes europeos, Simón Rodríguez y Andrés uso de técnicas de tiempo compartido, redes de comunicaciones, junto con la alta capacidad de menos del tiempo de una generación humana, los computadores se han convertido en máquinas versátiles y

  18. Au-del de la Revolucin ! Un regard critique sur le Venezuela contemporain

    E-print Network

    Paris-Sud XI, Université de

    profundos que transforman el país en el marco de la explotación petrolera, dando origen a muchas de las and two decades of crisis which sharpen inequalities. Nevertheless, both the socio political order: Bolivarian Revolution, Oil-State, socio-political order, Punto-fijism, distribution of power Le président

  19. expansion of Ciudad Guayana in Venezuela, Apple-yard interviewed hundreds of inhabitants of that

    E-print Network

    Rensink, Ronald A.

    studies in human spatial cognition and development (Piaget & Inhelder, 1969; Hart & Moore, 1973; Siegel long been dominated by the so-called stage theory, i.e. the notion that there are three distinct types learning and development. Based on the results of a route learning experiment in a driving simulator

  20. A social learning approach to the study of intrastate political violence: the case of Venezuela 

    E-print Network

    Roberts, Sherman Douglas

    1971-01-01

    parties, two new political parties were organized during the period of provisional government. The Comi. te para la Organizacion Polit1ca y Electoral . Independiente (C. O. P. E. I. ) led by Rafael Caldera drew 1n church support and the support of many...

  1. [Sampling optimization for tropical invertebrates: an example using dung beetles (Coleoptera: Scarabaeinae) in Venezuela].

    PubMed

    Ferrer-Paris, José Rafael; Sánchez-Mercado, Ada; Rodríguez, Jon Paul

    2013-03-01

    The development of efficient sampling protocols is an essential prerequisite to evaluate and identify priority conservation areas. There are f ew protocols for fauna inventory and monitoring in wide geographical scales for the tropics, where the complexity of communities and high biodiversity levels, make the implementation of efficient protocols more difficult. We proposed here a simple strategy to optimize the capture of dung beetles, applied to sampling with baited traps and generalizable to other sampling methods. We analyzed data from eight transects sampled between 2006-2008 withthe aim to develop an uniform sampling design, that allows to confidently estimate species richness, abundance and composition at wide geographical scales. We examined four characteristics of any sampling design that affect the effectiveness of the sampling effort: the number of traps, sampling duration, type and proportion of bait, and spatial arrangement of the traps along transects. We used species accumulation curves, rank-abundance plots, indicator species analysis, and multivariate correlograms. We captured 40 337 individuals (115 species/morphospecies of 23 genera). Most species were attracted by both dung and carrion, but two thirds had greater relative abundance in traps baited with human dung. Different aspects of the sampling design influenced each diversity attribute in different ways. To obtain reliable richness estimates, the number of traps was the most important aspect. Accurate abundance estimates were obtained when the sampling period was increased, while the spatial arrangement of traps was determinant to capture the species composition pattern. An optimum sampling strategy for accurate estimates of richness, abundance and diversity should: (1) set 50-70 traps to maximize the number of species detected, (2) get samples during 48-72 hours and set trap groups along the transect to reliably estimate species abundance, (3) set traps in groups of at least 10 traps to suitably record the local species composition, and (4) separate trap groups by a distance greater than 5-10km to avoid spatial autocorrelation. For the evaluation of other sampling protocols we recommend to, first, identify the elements of sampling design that could affect the sampled effort (the number of traps, sampling duration, type and proportion of bait) and their spatial distribution (spatial arrangement of the traps) and then, to evaluate how they affect richness, abundance and species composition estimates. PMID:23894965

  2. Treading & threading memories: a personal encounter with forest and people in Southern Venezuela

    PubMed Central

    2013-01-01

    This brief essay, which represents the third editorial of the series "Recollections, Reflections, and Revelations: Ethnobiologists and their First Time in the Field", captures a few memories of the author's first fieldwork in the Venezuelan rainforest. It is a collage of objects, subjects, feelings, spaces, and events that pendulate in spheres of meaning straddling between the author's identities as both a student and a woman. The author's evocations of fifteen years ago are diluted in lasting reflections about what could be ethnoecology embraced by spaces of interactions and associations between organisms and their surroundings. PMID:23915266

  3. Sand waves, bars, and wind-blown sands of the Rio Orinoco, Venezuela and Colombia

    USGS Publications Warehouse

    Nordin, Carl F.; Perez-Hernandez, David

    1989-01-01

    During March 1982, a reconnaissance study was carried out along a reach of the Rio Orinoco between Puerto Ayacucho and Ciudad Bolivar. This was the low-flow season. Samples of bed material and suspended sediments were collected, sonic records of the bed were obtained at several locations, and the exposed bars and sand waves were studied at four locations. Sounding records were obtained at two of these locations during June and November when flow covered the bars, and additional studies were made on the ground at some of these same sites during March 1983. The bed of the river is mostly sand with small quantities, about 5 percent by weight on average, of gravel. Suspended- sediment concentrations were low, ranging between 20 milligrams per liter above Rio Apure to almost 40 milligrams per liter below its confluence with the Rio Orinoco. The annual sediment load is estimated to be 240x10 6 megagrams per year. During the dry season, 35 percent or more of the bed is exposed in the form of large bars composed of many sand waves. Trade winds blow upriver and there is substantial upriver transport of river sediments by the wind. If the bars contain very coarse sands and fine gravel, deflation forms a lag deposit that armors the bar surface and prevents further erosion. Theoretical calculations show that the lower limit for the fraction of the bed that needs to be covered with nonmoving particles to prevent further erosion and the smallest size of the armor particles depend only on wind speed. Calculations of bed-material transport were made for a typical wide and narrow section of the river; the annual load, excluding the wash load, is about 30 x 10 6 megagrams per year. A new definition for wash load is proposed; it is material that can be suspended as soon as its motion is initiated. For the Rio Orinoco, this is material finer than 0.1 millimeters.

  4. The fluvial geochemistry and denudation rate of the Guayana Shield in Venezuela, Colombia, and Brazil

    Microsoft Academic Search

    J. M. Edmond; M. R. Palmer; C. I. Measures; B. Grant; R. F. Stallard

    1995-01-01

    The Guayana Shield is composed of Early to Mid-Precambrian igneous and metamorphic basement rocks with a quartzitic platform cover. The complete absence of limestones and evaporites allows a clear chemical expression in the stream data of the primary weathering of the basement in a humid tropical environment. Total erosion rates are extremely slow, ?10 m\\/m.y., with equal contributions from the

  5. Knowledge Partnerships: Rapid Rural Appraisal's Role in Catalyzing Community-Based Management in Venezuela

    Microsoft Academic Search

    Brooke Ann Zanetell; Barbara A. Knuth

    2002-01-01

    In addition to political partnerships. less-explored components of community-based management (CBM) are knowledge partnerships that blend expert opinion and local ecological wisdom into a comprehensive wellspring for environmental decision making. The exclusion through omission of local input in knowledge construction is a consequence of widespread application of positivist methods that are ill-equipped to engage and empower local knowledge. These gaps

  6. Tropical floodplain agroforestry systems in mid-Orinoco River basin, Venezuela

    Microsoft Academic Search

    E. Barrios; R. Herrera; J. L. Valles

    1994-01-01

    Agricultural studies in seasonally flooded areas in the tropics have been limited. Orinoco alluvial soils are more fertile than adjacent non-flooded soils, and have been considered as potential areas for further agricultural development. Traditional agroforestry practices offer some possibilities to overcome the most limiting factors of floodplain cultivation. Indigenous knowledge of these traditional agroforestry practices was assessed and some indicators

  7. Rainfall partitioning by a semideciduous forest grove in the savannas of the Orinoco Llanos, Venezuela

    NASA Astrophysics Data System (ADS)

    San Jose, J. J.; Montes, R.

    1992-03-01

    A study of rainfall partitioning into throughfall, stem flow and interception loss was conducted during five annual cycles in a patch of semideciduous forest within the Trachypogon savanna in the Orinoco Llanos. Annual seasonal rainfall (April-November) was 1238 mm, 1228 mm, 1531 mm, 1345 mm and 1398 mm for 1981, 1982, 1983, 1984 and 1985, respectively. During the years analyzed (1981-1984), the throughfall measured using a roving gauge technique was 75.7% (±1.2%), 81.8% (±1.2%), 74.1% (±1.1%) and 77.4% (±0.2%), respectively, of the gross precipitation. The rain required to initiate average throughfall in the grove ranged from 0.6 to 1.0 mm. Of the rainfall reaching the grove canopy, 1.0% (±0.2%), 1.1% (±0.2%) and 0.4% (±0.00%) flowed down the trunks as stem flow in 1983, 1984 and 1985, respectively. Consequently, interception loss accounted for 19% and 12% of gross rainfall for 1983 and 1984, respectively. Regression analysis indicated that throughfall, stem flow and interception loss as a function of gross rainfall followed similar linear patterns. Volume of stem flow was related to tree diameter but it decreased at the highest diameter class.

  8. Diurnal cycles of formic and acetic acids in the northern part of the Guayana Shield, Venezuela

    NASA Astrophysics Data System (ADS)

    Hartmann, W. R.; Andreae, M. O.; Santana, M.; Hermoso, M.; Sanhueza, E.

    1991-07-01

    Formic and acetic acids were measured in a scrub-grass savanna and in a nearby semideciduous forest. Gaseous HCOOH and CH3COOH were collected using the mist-scrubber technique, and were determined using ion chromatography. A strong diurnal cycle was observed at both sites, with higher mixing ratios during daytime. Concentrations in the savanna were always higher than in the forest. Most of the time HCOOH/CH3COOH ratios greater than one were recorded at the savanna site, and ratios less than one at the forest site. Boundary-layer mixing ratios in the savanna region, derived from measurements during midday, are 1.3 +/- 0.4 ppbv and 0.7 +/- 0.3 ppbv for HCOOH and dCH3COOH. Dry depositions velocities between 0.5 and 1 cm sq were estimated for the savanna region. Atmospheric residence times of less than 3 days and greater than 5 days were estimated for the rainy and dry season, respectively.

  9. Evaluation of prospective modelling methods: fuzzy logics and cellular automaton applied to deforestation in Venezuela

    Microsoft Academic Search

    G Selleron; T Mezzadri-Centeno

    Spatial evolutions of anthropized ecosystems and the progressive transformation of spaces through the course of time emerge\\u000a more and more as a special interest issue in research about the environment. This evolution constitutes one of the major concerns\\u000a in the domain of environmental space management. The landscape evolution of a regional area and the perspectives for a future\\u000a state raise

  10. A palynological record of a secondary succession after fire in the Gran Sabana, Venezuela

    NASA Astrophysics Data System (ADS)

    Rull, Valentí

    1999-03-01

    Fire has been considered one of the most important factors in the expansion of savannas in the Gran Sabana region. In Urué, an important fire event that occurred before 1.6 kyr BP led to the replacement of primary forests by savannas and morichales (monospecific communities of the palm Mauritia). In the present work, the secondary succession after fire is reconstructed by palynological analysis of a previously dated clay core, and the results are compared with those from studies based on present-day ecosystems. Charcoal analysis is used to infer fire incidence and surface samples are used as modern analogues. The secondary succession is subdivided into seven seral stages: open secondary forests, helechal or dense fern community, transitional savanna, wet savanna with morichales, treeless savanna, wet savanna with morichales, and treeless savanna. Fires were common at the beginning, but climate constituted the main successional control from the transitional savanna stage onwards. The process is characterised by a continuous impoverishment of taxa, but there was a steady increase in Mauritia, due to its ability to colonise new habitats created by disturbances. The conclusions of this palynological reconstruction show good correspondence with present-day studies on fire ecology.

  11. Eocene tectonic controls on reservoir distribution in VLE 196, Block V, Lamar Field, Maracaibo Basin, Venezuela

    E-print Network

    Choi, Byeonggoo

    2006-10-30

    .2.5. Retrogradational Geometry by Stacking of Aggradation Strata...........................................................................................135 4.3. Discussion... .....................................................................................100 xiv FIGURE Page 3-35. Conceptual cross-section showing stacked aggradational components display retrogradational geometries...

  12. Percepcin Activa para la Identificacin y Localizacin de Patrones 2D.

    E-print Network

    Ros, Lluís

    sistema se decida mas fácilmente por alguna de las interpretaciones posibles. Los modelos utilizados se proyectos "Razonamiento espacial automático basado en restricciones"(TIC 88-0197) y "Sistema de percepción interpretaciones. Una inter- pretación consiste en un emparejamiento entre informaciones y elementos del modelo que

  13. A preliminary analysis of geographic variation in the neotropical teiid lizard, Cnemidophorus lemniscatus (Sauria: Teiidae), from Mainland Central and South America 

    E-print Network

    McCrystal, Hugh Kreyer

    1984-01-01

    localities together. The samples were taken throughout most of the known range of the mainland population of C. lemniscatus, north of the Bio Amazonas, Brazil, with particular emphasis on Colombia and Venezuela. Specimens from the Amazon Basin were... = Puerto Cortes, Honduras; g4 = Surinam; T";5 = i~laturin, Venezuela; 66 Falcon, Venezuela; g7 = Bolivar, Venezuela; g8 = Camatagua, Venezuela; P9 = Guyana; $1G Baranquilla, Colombia; $11 = Yaviza, Panama; 514 = Apure, Venezuela; f16 = Villavicencio...

  14. Vinculacion Entre La Educacion Y El Mundo Del Trabajo: Informe Final. (Coloquio Regional Caracas, Venezuela, Septiembre 2-6, 1985) = The Linkage Between Education and Employment: Final Report of the Regional Colloquium (Caracas, Venezuela, September 2-6, 1985).

    ERIC Educational Resources Information Center

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

    At this regional colloquium 13 papers were presented concerning the relationship between education and employment. Themes addressed were: (1) the transformation of the workplace by technology and science; (2) the future of the disadvantaged population as a consequence of the technological revolution; and (3) the resulting changes in the education…

  15. ANATOMÍA DE COMMELINACEAE PRESENTES EN UN CULTIVO DE PAPAS (SOLANUM TUBEROSUM L.) EN MÉRIDA, VENEZUELA Anatomy of Commelinaceae present in a culture of potatoes (Solanum tuberosum L.) in Merida, Venezuela

    Microsoft Academic Search

    Rebeca LUQUE ARIAS; Javier ESTRADA SÁNCHEZ

    2005-01-01

    Commelinaceae is, after Poaceae and Cyperaceae, the family of monocotiledons with the greatest number of weeds associated to cultures; among them, some species of Commeli- na and Tinantia are host for acarus, rust and virus, like the Potato Y potyvirus that affects Solanum tuberosum. In the Andes of Mérida, Commelina obliqua and Tinantia erecta grow like weeds in cultivation of

  16. Percepciones de los estudiantes de education en Venezuela sobre su preparacion e intervencion en violencia domestica. [Perceptions of Education Students in Venezuela about Their Preparation and Intervention in Domestic Violence].

    ERIC Educational Resources Information Center

    McArthur, Anna P.; Cellitti, Anarella; Perez de Linares, Sonia

    1999-01-01

    This study investigated Venezuelan university students' perceptions regarding domestic violence and possible encounters with domestic violence in programs for young children. Students indicated that they expected to encounter only those situations they were prepared to confront, indicating needs for curriculum changes in teacher-training programs.…

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

    E-print Network

    Rodriguez, Manuel Gregorio

    1999-01-01

    cyclic steam injection and steamflooding. The Cartesian model dimensions of the three horizontal welts were 11x22x4, 11x27x5, and 12x20x5. In the steamflooding scheme investigated, the existing horizontal welts were used as injectors while existing (and...

  18. Geology of the reservoirs from interval I of the Oficina formation, Greater Oficina area, eastern Venezuela Basin

    SciTech Connect

    Rivero, C.A.; Scherer, W. [Intevep, S.A., Los Teques (Venezuela)

    1996-08-01

    In order to determine the geologic features of the reservoirs and their areal statistical distribution and geometry, a study was made of a selected interval where the sands present less coalescence and the reservoirs are clearly defined. The study area comprises 1900 km{sup 2} of the Greater Oficina area; core samples, logs and reservoir maps were used. It was found that interval I consists of interbedded sandstones, shales, some siltstone, and occasionally lignites. Based upon lithologic mesoscopic features, eight (8) characteristic lithofacies could be defined. Rocks classified as sub-litharenites, sub-arkoses, arkoses lithic sandstones and graywackes could be inferred as belonging to a fluvio-deltaic system sourced on the Pre-Cambrian Guayana shield. The diagenetic level reached by the sequence corresponds to the intermediate stage, where significant processes of cementation by oxides, carbonates and silica are of equal intensity and magnitude to the lixiviation of feldspars and other detritic particles, giving these rooks good potential reservoir qualities. Descriptive statistical evaluation was performed on 140 reservoirs representing all lithofacies populations in this interval. Based on this analysis reservoirs were statistically grouped in classes which are a function of their geometry, spatial location and type of hydrocarbon content.

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

    E-print Network

    Meyers, Steven D.

    Clay mineralogy of surface sediments as a tool for deciphering river contributions to the Cariaco the Cariaco Basin continental shelf and Orinoco delta was investigated in order to constrain the clay was studied using a geo-statistical approach that allows drawing representative clay-mineral distribution maps

  20. 15,000-yr pollen record of vegetation change in the high altitude tropical Andes at Laguna Verde Alta, Venezuela

    Microsoft Academic Search

    Valentí Rull; Mark B. Abbott; Pratigya J. Polissar; Alexander P. Wolfe; Maximiliano Bezada; Raymond S. Bradley

    2005-01-01

    Pollen analysis of sediments from a high-altitude (4215 m), Neotropical (9°N) Andean lake was conducted in order to reconstruct local and regional vegetation dynamics since deglaciation. Although deglaciation commenced ?15,500 cal yr B.P., the area around the Laguna Verde Alta (LVA) remained a periglacial desert, practically unvegetated, until about 11,000 cal yr B.P. At this time, a lycopod assemblage bearing

  1. [Composition and structure of the macrofauna associated with beds of two bivalve species in Cubagua Island, Venezuela].

    PubMed

    Hernández-Avila, Iván; Tagliafico, Alejandro; Rago, Nestor

    2013-06-01

    Bivalve aggregations constitute a microhabitat for a wide variety of organisms in intertidal, subtidal and deep-water marine benthic habitats. Increase in density of bivalve beds could offer more crevices and substratum for the associated fauna, affecting community composition. Beds of the Atlantic Pearl Oyster (Pinctada imbricata) and the Turkey Wing (Arca zebra) of contrasting population densities were evaluated to determine the composition and structure of the associated macrofauna of three taxa (Crustacea Decapoda, Mollusca and Echinodermata). We evaluated plots of three levels of bed density in both species, the associated fauna were identified and counted. Other species were collected by qualitative samples. Univariate and multivariate descriptors were tested comparing the associated fauna between the beds of two species at three levels of density. In these beds a total of 104 species belonging to 58 families were recorded. Mithraculus forceps (Majidae), Crucibulum auricula (Calyptraeidae) and Ophiotrix angulata (Ophiothrichidae) were the most common species found in these assemblages. The medium and high-density bivalve beds exhibited greater species number, abundance, Shannon diversity, evenness, taxonomic diversity, and taxonomic distinctness of associated fauna, than low-density bivalve beds. Moreover, multivariate analysis detected different assemblages of associated fauna between beds with different densities. Additionally, similarities were found in the communities of macrofauna in both beds of P imbricata and Area zebra. Our results suggest that bivalve aggregations at Cubagua Island provide additional habitat for macrofauna living in other shallow habitats such as Thalassia beds, corals and rocky environments. Bed density, associated with topographic complexity, represents an important factor for the composition and complexity of the associated fauna. PMID:23885582

  2. THE QUANTITY AND TURNOVER OF DEAD WOOD IN PERMANENT FOREST PLOTS IN SIX LIFE ZONES OF VENEZUELA

    EPA Science Inventory

    Dead wood can be an important component of the carbon pool in many forests, but few measurements have been made of this pool in tropical forests. To fill this gap, we determined the quantity of dead wood (downed and standing dead) in 25 long-term (up to 30 yr) permanent forest pl...

  3. Seasonal variability of total dissolved fluxes and origin of major dissolved elements within a large tropical river: The Orinoco, Venezuela

    NASA Astrophysics Data System (ADS)

    Laraque, Alain; Moquet, Jean-Sébastien; Alkattan, Rana; Steiger, Johannes; Mora, Abrahan; Adèle, Georges; Castellanos, Bartolo; Lagane, Christèle; Lopez, José Luis; Perez, Jesus; Rodriguez, Militza; Rosales, Judith

    2013-07-01

    Seasonal variations of total dissolved fluxes of the lower Orinoco River were calculated taking into account four complete hydrological cycles during a five-year period (2005-2010). The modern concentrations of total dissolved solids (TDS) of the Orinoco surface waters were compared with data collected during the second half of the last century published in the literature. This comparison leads to the conclusion that chemical composition did not evolve significantly at least over the last thirty to forty years. Surface waters of the Orinoco at Ciudad Bolivar are between bicarbonated calcic and bicarbonated mixed. In comparison to mean values of concentrations of total dissolved solids (TDS) of world river surface waters (89.2 mg l-1), the Orinoco River at Ciudad Bolivar presents mainly low mineralized surface waters (2005-10: TDS 30 mg l-1). The TDS fluxes passing at this station in direction to the Atlantic Ocean between 2005 and 2010 were estimated at 30 × 106 t yr-1, i.e. 36 t km-2 yr-1. It was observed that the seasonal variations (dry season vs wet season) of total dissolved fluxes (TDS and dissolved organic carbon (DOC)) are mainly controlled by discharge variations. Two groups of elements have been defined from dilution curves and molar ratio diagrams. Ca2+, Mg2+, HCO3-, Cl- and Na+ mainly come from the same geographic and lithologic area, the Andes. K+ and SiO2 essentially come from the Llanos and the Guayana Shield. These findings are important for understanding fundamental geochemical processes within the Orinoco River basin, but also as a baseline study in the perspective of the development of numerous mining activities related with aluminum and steel industries; and the plans of the Venezuelan government to construct new fluvial ports on the lower Orinoco for the transport of hydrocarbons.

  4. Temporal variation and fluxes of dissolved and particulate organic carbon in the Apure, Caura and Orinoco rivers, Venezuela

    NASA Astrophysics Data System (ADS)

    Mora, Abrahan; Laraque, Alain; Moreira-Turcq, Patricia; Alfonso, Juan A.

    2014-10-01

    The concentrations of total suspended sediments (TSS), dissolved organic carbon (DOC) and particulate organic carbon (POC) were measured in water samples taken monthly in the Apure, Caura and Orinoco rivers during a hydrological cycle (between Sept. 2007 and Aug. 2008). The DOC concentration values ranged between 1.5 and 6.8 mgC l-1 in the Apure River; 2.07 and 4.9 mgC l-1 in the Caura River and 1.66 and 5.35 mgC l-1 in the Orinoco River. The mean concentration of DOC was 3.9 mgC l-1 in the Apure River, 3.24 mgC l-1 in the Caura River and 2.92 mgC l-1 in the Orinoco River at Puerto Ordaz. The three rivers showed a similar temporal pattern in the concentrations of DOC, with higher DOC values during the increasing branch of the hydrograph due to wash-out processes of the organic material stored in soils. The mean concentration values of POC were 1.33 mgC l-1; 0.77 mgC l-1 and 0.91 mgC l-1 in the Apure, Caura and Orinoco rivers, respectively. The inverse relationship found between the percentage in weight of the POC and the concentrations of TSS in the three rivers fits a logarithmic model, as it has been previously reported for other worldwide rivers. The POC concentrations in the Orinoco River showed a positive relationship with the TSS, suggesting that the POC in the Orinoco is the result of terrestrially organic matter. Although the fluxes of organic carbon (OC) in the three studied rivers are dependent on the values of water discharge, the fluxes of DOC during the increasing branch of the hydrograph are higher than those found during the decreasing stage, due to the yield of organic material accumulated in soils during the preceding dry season. The mean annual flux of total organic carbon (TOC) of the Orinoco River at Puerto Ordaz was about 4.27 × 106 TonC yr-1. Of this, 3.28 × 106 TonC yr-1 (77%) represents the flux of DOC and about 0.99 TonC yr-1 (23%) represents the flux of POC. The mean annual input of TOC from the Apure River to the Orinoco River was about 4.92 × 105 TonC yr-1 (11.5%), while the contribution of TOC from the Caura River to the Orinoco River was estimated at 3.05 × 105 TonC yr-1 (7.1%). The values of annual transport of TOC calculated for the Apure, Caura and Orinoco rivers were lower than those reported twenty years ago. This could be related to interannual variations of precipitation in the Orinoco Basin, due to runoff variations can have a strong effect on the fluxes of OC from land to rivers.

  5. FORAGING ECOLOGY OF SEVEN SPECIES OF NEOTROPICAL IBISES (THRESKIORNITHIDAE) DURING THE DRY SEASON IN THE LLANOS OF VENEZUELA

    Microsoft Academic Search

    PETER C. FREDERICK; KEITH L. BILDSTEIN

    we describe the relative abundance, foraging habitat, and feeding behavior of seven sympatric species of ibises (Threskiomithidae) in the Venezuelan llanos during the dry season of 1989. Scarlet (Eudocimus ruber), Glossy (Plegadis falcinellus), and Bare-faced (Phimosus infiscatus) ibises were the most common species. White (E. albus), Green (Me- sembrinibis cayennensis), Sharp-tailed (Cercibis oxycerca), and Buff-necked (Theristicus cau- datus) ibises together

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

    NASA Astrophysics Data System (ADS)

    Bout-Roumazeilles, V.; Riboulleau, A.; ChâTelet, E. Armynot; Lorenzoni, L.; Tribovillard, N.; Murray, R. W.; Müller-Karger, F.; Astor, Y. M.

    2013-02-01

    The mineralogical composition of 95 surface sediment samples from the Cariaco Basin continental shelf and Orinoco delta was investigated in order to constrain the clay-mineral main provenance and distribution within the Cariaco Basin. The spatial variability of the data set was studied using a geo-statistical approach that allows drawing representative clay-mineral distribution maps. These maps are used to identify present-day dominant sources for each clay-mineral species in agreement with the geological characteristics of the main river watersheds emptying into the basin. This approach allows (1) identifying the most distinctive clay-mineral species/ratios that determine particle provenance, (2) evaluating the respective contribution of local rivers, and (3) confirming the minimal present-day influence of the Orinoco plume on the Cariaco Basin sedimentation. The Tuy, Unare, and Neveri Rivers are the main sources of clay particles to the Cariaco Basin sedimentation. At present, the Tuy River is the main contributor of illite to the western part of the southern Cariaco Basin continental shelf. The Unare River plume, carrying smectite and kaolinite, has a wide westward propagation, whereas the Neveri River contribution is less extended, providing kaolinite and illite toward the eastern Cariaco Basin. The Manzanares, Araya, Tortuga, and Margarita areas are secondary sources of local influence. These insights shed light on the origin of present-day terrigenous sediments of the Cariaco Basin and help to propose alternative explanations for the temporal variability of clay mineralogy observed in previously published studies.

  7. Miocene biostratigraphy of Northern Monagas, Eastern Venezuela: Biological signals of sea level and Paleoceanographic changes in a foreland basin

    SciTech Connect

    Crespo de Cabrera, S. (Corpoven S.A., Puerto La Cruz (Venezuela)); Radford, S. (Imperial College London (United Kingdom))

    1993-02-01

    Foraminiferal studies in the Carapita and La Pica formations have provided interesting patterns which could be correlated with paleoceanographic changes brought about by relative sea level changes, among other causes. By their effects on physicochemical parameters, relative sea level changes will affect the character, composition and distribution of marine biofacies. Patterns of foraminiferal abundance and diversity and the appearances and extinctions of species have been used to attempt a characterization of system tracts. This is a part of sequence stratigraphy very poorly understood, especially in deep water environments, where abundance peaks occur at several condensed sections within lowstand system tracts in addition to maximum flooding surfaces. The Carapita Formation is of Early to Middle Miocene age, zones N4 to N14 and correspond to the upper part of the TB1 and TB2 second order cycles of the Hag et al. chart. It was deposited predominantly in bathyal paleoenvironments, though neritic conditions have been determined at the base and summit of this formation. It is unconformably overlain by intercalations of sandstones and shales known as La Pica Formation, of Late Miocene age, deposited on environments ranging from inner neritic to continental. This probably correlates with the lower part of the TB3 super cycle. Both formations were deposited in a foreland basin, formed at the beginning of the Neogene by the southeastward thrusting of the Caribbean plate over the South American continent.

  8. Species co-occurrence and feeding behavior in sand fly transmission of American cutaneous leishmaniasis in western Venezuela

    Microsoft Academic Search

    Luis Fernando Chaves; Nestor Añez

    2004-01-01

    The structure of the Phlebotomine sand fly community from the Venezuelan Andes was studied using null-model tests. The analyses, at the living zones and altitudes scales, revealed C-scores larger than those expected by random, independently of the collection technique (P < 0.05). These results imply that sand fly species are non-aggregated at both scales. Random results for the variance of

  9. "What's wrong with me?": cervical cancer in Venezuela--living in the borderlands of health, disease, and illness.

    PubMed

    Martínez, Rebecca G

    2005-08-01

    Social scientists concerned with studying the social and cultural meaning of illness problematize the relationship between disease and illness, noting that illness can exist without disease-abnormal physical changes in the body. What has received less attention is the existence of disease-made visible through technological advances-in the absence of illness. Cervical cancer (or the more ambiguous cervical abnormalities) is an example of a disease that is largely symptomless in its early stages and can occur in the absence of illness. In this paper I explore how women seek to understand and negotiate cervical cancer in the context of their everyday lives, as they are confronted with seemingly disparate and contradictory physical and psychological states of well-being, sickness, and disease. This experience is what I call living on the borderlands of health, disease, and illness, where all of these states are experienced concurrently and boundaries between them blur. Through observations of patient-doctor interactions, ethnographic interviews with doctors and women seeking treatment for cervical cancer and pre-cancerous abnormalities, I analyze how women try to understand their medical experience. And they do so with the added challenge of little information being shared with them by the doctors who treat them. While patients do not ask many questions of their doctors, this does not mean that women are disinterested in their health. In fact, they develop strategies for eliciting clinical information about their medical conditions and actively seek to make sense of their experiences. By problematizing the concepts of health, disease, and illness, and avoiding the tendency to see these as distinct and contradictory phenomenon, we can gain a better understanding of their interrelatedness, and how people negotiate this borderland. PMID:15950092

  10. The study of the accumulation of hydrocarbons in VLE 196, Block V, Lamar field, Lake Maracaibo, Venezuela 

    E-print Network

    Leveque, Soazig

    2001-01-01

    to better anticipate production behavior and to explore new areas that are more complex. Five reflectors were picked: the overlying unconformity, C4 reservoir layer, C5 reservoir layer, the Guasare Formation and the La Luna Formation (the source rock...

  11. [Reproduction of the Spanish sardine, Sardinella aurita (Clupeiformes: Clupeidae) from the south-eastern area of Margarita Island, Venezuela].

    PubMed

    Gassman, Juan; Eslava, Nora; González, Leo W

    2008-12-01

    Sex ratio, sexual maturity, fecundity and time of spawning of the Spanish sardine (Sardinella aurita) from the south-eastern area of Margarita Island were determined through monthly samplings of commercial fisheries, from January 2004 to April 2005. A total of 3 736 individuals were examined. Sex ratio was 55.47% females and 44.53% males, with a 1:1.25 sexual proportion (chi2 = 44.454, p < 0.05). Length at first sexual maturity (L50) was 20 cm. Spawning of the species was confirmed to be partial and continuous throughout the year, with two peaks of intensity during the first and last quarters. Absolute fecundity ranged from 10,530 to 83,779 oocytes and it was proportional to body length (F = -100,900 + 6696.2 * L) and to body weight (F = 13,327 + 5666.3 * P). Relative fecundity ranged from 149 to 1020 oocytes/g and also was proportional to body length and weight. We concluded that the Spanish sardine exhibits two peaks of spawning activity per year with a very fluctuating partial fecundity which could possibly be explained by environmental variability. PMID:19419083

  12. THE DISTRIBUTION OF ORGANIC CARBON IN MAJOR COMPONENTS OF FORESTS LOCATED IN FIVE LIFE ZONES OF VENEZUELA

    EPA Science Inventory

    One of the major uncertainties concerning the role of tropical forests in the global carbon cycle is the lack of adequate data on the carbon content of all their components. The goal of this study was to contribute to filling this data gap by estimating the quantity of carbon in ...

  13. Reservoir characterization of the upper Merecure and lower Oficina Formations sands in the Leona Este Field, Eastern Venezuela Basin 

    E-print Network

    Flores Millan, Maria Carolina

    2001-01-01

    interval presents one or more reservoir zones composed by sandy deposits that fill belts of stacked tidal-fluvial channels in a SSE-NNW trending tide-dominated estuarine system. In most intervals, these contemporaneous-in-deposition reservoir zones...

  14. VARYING GENETIC DIVERSITY OF PAPAYA RINGSPOT VIRUS ISOLATES FROM TWO TIME-SEPARATED OUTBREAKS IN JAMAICA AND VENEZUELA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The coat protein (CP) genes of eleven Jamaican Papaya ringspot virus type-p (PRSV) isolates that were collected in 1999 were cloned and sequenced. The nucleotide and amino acid sequences of these isolates were compared to each other, with a sequence of another Jamaican isolate collected after the f...

  15. MODELO DE UTILIZACIÓN CEREAL-PASTO EN SISTEMAS DE PRODUCCIÓN DE SABANAS BIEN DRENADAS CON SUELOS ÁCIDOS EN VENEZUELA

    Microsoft Academic Search

    José L. Berroterán

    SUMMARY This paper proposes a management model for acid-soil savannas applicable to mixed farm systems, to make efficient use of the available forage throughout the year. The area of low- fertility soils in the Venezuelan savannas covers a surface of about 130,000 km 2. They have a mesoclimate with a pronounced rainy season and a dry season with hydric deficit,

  16. Phytogeography of the vascular páramo flora of Ramal de Guaramacal (Andes, Venezuela) and its ties to other páramo floras

    Microsoft Academic Search

    N. L. Cuello; A. M. Cleef; G. Aymard

    2010-01-01

    Ramal de Guaramacal is an outlier and lower elevation mountain range located at the northeastern end of the Venezuelan Andes. Phytogeographical patterns and affinities of the low altitude and wet vascular páramo flora of Ramal de Guaramacal, have been studied with emphasis in to the analysis of the floristic connections of the Guaramacal páramo flora with the neighboring dry páramos

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

    E-print Network

    Urdaneta Anez, Jackeline C

    2001-01-01

    S.A. (PDVSA). This research provides a full-field numerical simulation that predicts performance and aids in planning future development with infill wells for a reservoir located at the south of Block V, Lamar in Lake Maracaibo. The simulation...

  18. Petrographic and Vitrinite Reflectance Analyses of a Suite of High Volatile Bituminous Coal Samples from the United States and Venezuela

    USGS Publications Warehouse

    Hackley, Paul C.; Kolak, Jonathan J.

    2008-01-01

    This report presents vitrinite reflectance and detailed organic composition data for nine high volatile bituminous coal samples. These samples were selected to provide a single, internally consistent set of reflectance and composition analyses to facilitate the study of linkages among coal composition, bitumen generation during thermal maturation, and geochemical characteristics of generated hydrocarbons. Understanding these linkages is important for addressing several issues, including: the role of coal as a source rock within a petroleum system, the potential for conversion of coal resources to liquid hydrocarbon fuels, and the interactions between coal and carbon dioxide during enhanced coalbed methane recovery and(or) carbon dioxide sequestration in coal beds.

  19. Unusual presentation of hepatitis B serological markers in an Amerindian community of Venezuela with a majority of occult cases

    PubMed Central

    2011-01-01

    Background Occult hepatitis B infection (OBI) is characterized by the presence of hepatitis B virus (HBV) DNA in the absence of HBsAg in the serum of patients. The aim of this study was to characterize HBV infection among a Piaroa community, an Amerindian group which exhibits significant evidence of exposure to HBV but relatively low presence of HBsAg, and to explore the presence of OBI in this population. Results Of 150 sera, with 17% anti-HBc and 1.3% HBsAg prevalence, 70 were tested for the presence of HBV DNA. From these, 25 (36%) were found positive for HBV DNA by PCR in the core region. Two of these 25 sera were HBsAg positive, indicating an overt infection. Of the remaining 68 sera tested, 23 exhibited OBI. Of these, 13 were HBV DNA out of 25 anti-HBc positive (52%) and 10 HBV DNA positive, out of 43 anti-HBc negative (23%), with a statistical significance of p = 0.03. Viral DNA and HBsAg were present intermittently in follow up sera of 13 individuals. Sequence analysis in the core region of the amplified DNA products showed that all the strains belonged to HBV genotype F3. The OBI isolates displayed 96-100% nucleotide identity between them. One isolate exhibited the co-circulation of a wild type variant with a variant with a premature stop codon at the core protein, and a variant exhibiting a deletion of 28 amino acids. Conclusions The frequency of OBI found in this Amerindian group warrants further studies in other communities exhibiting different degrees of HBV exposure. PMID:22152023

  20. Chronology of mercury enrichment factors in reef corals from western Venezuela Ruth Ramos a,*, Roberto Cipriani b

    E-print Network

    Bermingham, Eldredge

    industries during the 1950s, and the constant weathering of natural deposits of cinabrium (HgS) have made environment via natural pro- cesses. Cinabrium (HgS), a mineral commonly present in the Earth's cortex

  1. [Prevalence of Listeria monocytogenes in fresh tomatoes (Lycopersicum esculentum) and coriander (Coriandrum sativum) in three markets of Valencia, Venezuela].

    PubMed

    Ramírez Mérida, Luis Guillermo; Morón de Salim, Alba; Alfieri Graterol, Ana Yudith; Gamboa, Orlando

    2009-09-01

    The incidence of L. monocytogenes in tomatoes and coriander obtained from three different markets, during eight weeks were determined. 192 samples were evaluated: 96 of tomatoes, and 96 of coriander. The isolation of L. monocytogenes was performed using COVENIN 3718:2001. The data were analyzed by SPSS version 12.0. Kolmogorov Smirnov, Mann Whitney U, Kruskal Wallis U test; Spearman's correlation were applied, and p<0.05 significance level was aplied. It was not found significant differences between the medias values and standard deviations of Most Probable Number (MPN) of Listeria spp to tomatoes and coriander during the eight weeks of recollection in the markets; neither between the distributions of MPN of tomatoes and coriander from the markets (Chi2=5,233 p<0,073; Chi2=1,624 p<0,444 respectively) neither the samples per weeks (Chi2=6,547 p<0,477; Chi2=2,667 p<0,914 respectively). In the number of MPN between tomatoes and coriander both distributions were significant different according to test U Mann Whitney U=3040,5 (Z=-4,216 p<0,0001). It was found statistical significance (p<0,001) between the number of MPN of tomatoes and coriander. The presence of Listeria spp in tomatoe was 41,66% (25,0% L. monocytogenes and 16,7% L. ivanovii); in coriander 77,08% (36,5% L. monocytogenes, 33,3% L. ivanovii and 7,3% L. seelige). We concluded that the high level of L. monocytogenes in tomatoes and coriander is independent of the markets store; we see the necessity of a microbiological control on the irrigation system, collection and distribution to ensure the quality of the product. PMID:19886518

  2. [Prevalence of no alcohol fatty liver disease (NAFLD) in a population of obese children in Valencia, Venezuela].

    PubMed

    Pontiles de Sánchez, Milagros; Morón de Salim, Alba; Rodríguez de Perdomo, Henny; Perdomo Oramas, Germán

    2014-06-01

    No Alcoholic Fatty Liver Disease (NAFLD) is characterized by an abnormal accumulation of fat in hepatocytes, without alcohol, where overweight and obesity are determinants. Ecosonografia evaluated the prevalence of fatty liver in obese pediatric patients and its relation to nutritional assessment. The sample consisted of 85 children (51 females, 34 males), age 3-17. The abdominal ecosonography, BMI, waist circumference were performed; Godard Test for physical activity, history of diabetes, dyslipidemia, obesity and cardiovascular disease were questioned. Lipid profile, glucose and insulin resistance were determined. Data analyzed from descriptive and comparative tables. We obtained: mean age 9.8 ± 2.7 females and males 9.6 ± 2.7 years. The ecosonography indicated 50% and 50% fatty liver-pancreas fatty liver in children aged 3-6 years; 7-11 years 39.7% fatty liver-pancreas; 12-17yrs 31.6% fatty liver-pancreas (p > 0.05); BMI > 26 kg/m2 42.9% fatty liver-pancreas; 21 to 25 kg/m2 44.7% fatty liver; 15 to 20 kg/m2 60%fatty liver-pancreas (p> 0.05). 97.6% with high CC; 68.2% with inadequate physical activity; high frequency of history of chronic non-communicable diseases. We concluded that this population had predominantly fatty liver fatty replacement of the pancreas (HG-RGP) in the groups with higher BMI, CC and high male unrelated insulin resistance, altered lipid profile and diagnosis HG. We inferred that the anthropometric assessment of waist circumference and abdominal ecosonography indicate the presence of visceral obesity, a condition that predisposes to hepatic steatosis, pancreas and/or liver-pancreas. PMID:25799683

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

    E-print Network

    Rodriguez, Manuel Gregorio

    1999-01-01

    cyclic steam injection and steamflooding. The Cartesian model dimensions of the three horizontal welts were 11x22x4, 11x27x5, and 12x20x5. In the steamflooding scheme investigated, the existing horizontal welts were used as injectors while existing (and...

  4. Sedimentology and diagenesis of misoa C-2 reservoir, VLE-305/326 area, block V, Lamar Field, Maracaibe Lake, Venezuela

    SciTech Connect

    Cabrera de Casas, L.; Chacartegui, F. (Maraven S.A., Caracas (Venezuela))

    1993-02-01

    The main purpose of this study was to characterize the Upper Eocene C-2 reservoir using sedimentological, petrophysical and biostratigraphic parameters. The reservoir quality was evaluated by defining its physical attributes, geometry, areal distribution and orientation, from facies analysis of sedimentary units identified in core samples. In evaluating the sedimentary features of the Misoa C-2 reservoir in VLE 305/326 area, Block V, Lamar Field, Maracaibo Lake, 2,000' of cores from five wells (named VLe-339, VLE-720, VLE -723, VLe-754, LPG-1211) were analyzed. The sedimentary sequence studied represents upper-middle deltaic plain deposits with no marine influence. These deposits were identified as interdistributary channels, crevasse splays and interdistributary bays deposited in a northward prograding system. Seven sedimentary facies were defined from the physical, chemical and biological features observed in all cores. These facies were petrophysically and petrographically characterized then grouped in six sedimentary units which were then correlated over the entire area. One hundred well logs were correlated using sedimentological criteria. Finally, four flow units were identified in the reservoir using the sedimentological parameters, petrophysical data and production behavior. A surface trend analysis program utilizing thickness values resulted in contours, trends, residuals and isometry maps of each unit with a generalized southwest-northeast trend orientation. It was determined that facies distribution in the units controls the reservoir quality. These results are the main input into reservoir simulation. An accurate reservoir modeling is needed to prepare for optimizing secondary oil recovery.

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

    E-print Network

    sequence data Sari MOHALIy, Bernard SLIPPERS*, Michael J. WINGFIELD Department of Microbiology and Plant of woody plants, and they also include some serious pathogens of Eucalyptus and Acacia species. Numerous occur on a wide range of monocotyledonous, dicotyledonous, and gymnosperm hosts. Botryosphaeria spp

  6. Reservoir characterization of the upper Merecure and lower Oficina Formations sands in the Leona Este Field, Eastern Venezuela Basin

    E-print Network

    Flores Millan, Maria Carolina

    2001-01-01

    data (Figure 1. 6); 2) analysis of stacking patterns on well logs; 3) sedimentological analysis that determines rock types and fabrics to infer depositional settings; and 4) biostratigraphical analysis that reveals paleobathymetry and age... system 2 (F. S. 2): early passive margin-involved normal faults. 2. 1. 3 Fault system 3 (F. S. 3): late passive margin-involved normal faults. 2. 1. 4 Fault system 4 (F. S. 4): syndepositional normal faults of lower Middle-Miocene age ?. . 14...

  7. The study of the accumulation of hydrocarbons in VLE 196, Block V, Lamar field, Lake Maracaibo, Venezuela

    E-print Network

    Leveque, Soazig

    2001-01-01

    The Lake Maracaibo basin is a prolific basin. Its study is not straightforward due to complex tectonic history. At this time, most of the reservoirs have been found and our aim is to better understand the reservoirs and their characteristics...

  8. Weathering processes and the composition of inorganic material transported through the orinoco river system, Venezuela and Colombia

    USGS Publications Warehouse

    Stallard, R.F.; Koehnken, L.; Johnsson, M.J.

    1991-01-01

    The composition of river-borne material in the Orinoco River system is related primarily to erosion regime, which in turn is related to tectonic setting; especially notable is the contrast between material derived from tectonically active mountain belts and that from stable cratonic regions. For a particular morpho-tectonic region, the compositional suites of suspended sediment, bed material, overback deposits, and dissolved phases are fairly uniform are are typically distinct from whose of other regions. For each region, a consistent set of chemical weathering reactions can be formulated to explain the composition of dissolved and solid loads. In developing these formulations, erosion on slopes and storage of solids in soils and alluvial sediments are important considerations. Compositionally verymature sediment is derived from areas of thick soils where erosion is transport limited and from areas where sediments are stored for extended periods of time in alluvial deposits. Compositionally immature sediments are derived from tectonically active mountain belts where erosion is weathering limited. Weathering-limited erosion also is important in the elevated parts of the Guayana Shield within areas of sleep topography. Compared to the mountain belts, sediments derived from elevated parts of the Shield are more mature. A greater degree of chemical weathering seems to be needed to erode the rock types typical of the Shield. The major-element chemistry and mineral composition of sediment delivered by the Orinoco River to the ocean are controlled by rivers that have their headwaters in mountain belts and cross the Llanos, a region of alluvial plains within the foreland basin. The composition of sediments in rivers that drain the Shield seems to be established primarily at the site of soil formation, whereas for rivers that drain the mountain belts, additional weathering occurs during s episodes of storage on alluvial plains as sediments are transported across the Llanos to the main stem of the Orinoco. After mixing into the main stem, there seems to be little subsequent alteration of sediment. ?? 1991.

  9. IMPACTS OF LAND USE AND CULTURAL CHANGE IN A FRAGILE ENVIRONMENT: INDIGENOUS ACCULTURATION AND DEFORESTATION IN KAVANAYÉN, GRAN SABANA, VENEZUELA

    Microsoft Academic Search

    NANCY D. KINGSBURY

    2001-01-01

    o even the most casual observer, it appears that wide-scale deforestation has recently occurred in the Gran Sabana. For the Pemón Amerindians, who have oc- cupied the Gran Sabana for at least sev- eral centuries, the forests are the primary natural resource. They are the location of their conucos (shifting cultivation fields) and the source of game animals. Given the

  10. [Community structure of sponges (Porifera) in three reefs at Morrocoy National Park, Venezuela and its correspondence with some environmental variables].

    PubMed

    Romero, Marco A; Villamizar, Estrella; Malaver, Nora

    2013-09-01

    Sponges have an important ecological role in coral reef ecosystems. However, when compared to other benthic Phyla, it has been little researched. This research was focused in the variability of the community structure of sponges in three locations at Morrocoy National Park (Cayo Sombrero, Playa Mero and Punta Brava) exposed to different environmental conditions (transparency and currents intensity) and affected in different degree of severity by a mass mortality event in 1996. A total of 15 transects (10 m long and 1 m wide) were evaluated in three strata (between 3 and 15 m depth) in each site, where all the individuals were counted by species. Relative abundance by species, diversity and evenness were calculated. Locations showed differences respect turbidity, wave and current intensity. 27 species were found in Morrocoy; Cayo Sombrero (23), Playa Mero (18) and Punta Brava (15). Agelas sceptrum, Amphimedon erina and Niphates erecta were the most common in first location; Niphates erecta and Dysidea etheria in Playa Mero and Dysidea etheria, Niphates erecta and Amphimedon erina in Punta Brava. The species composition showed statistical differences between all three locations; Cayo Sombrero resulted the most diverse and even, followed by Playa Mero and Punta Brava. According to Sorensen Similarity Index results, Cayo Sombrero and Playa Mero were more similar, while Punta Brava resulted the most different. The variability in environmental conditions and the differential mass mortality effects of 1996 in all three reefs, were probably the main causes of the differences between their sponge communities. Nevertheless, we cannot conclude about the weight of these factors. PMID:24027920

  11. 15,000-yr pollen record of vegetation change in the high altitude tropical Andes at Laguna Verde Alta, Venezuela

    NASA Astrophysics Data System (ADS)

    Rull, Valentí; Abbott, Mark B.; Polissar, Pratigya J.; Wolfe, Alexander P.; Bezada, Maximiliano; Bradley, Raymond S.

    2005-11-01

    Pollen analysis of sediments from a high-altitude (4215 m), Neotropical (9°N) Andean lake was conducted in order to reconstruct local and regional vegetation dynamics since deglaciation. Although deglaciation commenced ˜15,500 cal yr B.P., the area around the Laguna Verde Alta (LVA) remained a periglacial desert, practically unvegetated, until about 11,000 cal yr B.P. At this time, a lycopod assemblage bearing no modern analog colonized the superpáramo. Although this community persisted until ˜6000 cal yr B.P., it began to decline somewhat earlier, in synchrony with cooling following the Holocene thermal maximum of the Northern Hemisphere. At this time, the pioneer assemblage was replaced by a low-diversity superpáramo community that became established ˜9000 cal yr B.P. This replacement coincides with regional declines in temperature and/or available moisture. Modern, more diverse superpáramo assemblages were not established until ˜4600 cal yr B.P., and were accompanied by a dramatic decline in Alnus, probably the result of factors associated with climate, humans, or both. Pollen influx from upper Andean forests is remarkably higher than expected during the Late Glacial and early to middle Holocene, especially between 14,000 and 12,600 cal yr B.P., when unparalleled high values are recorded. We propose that intensification of upslope orographic winds transported lower elevation forest pollen to the superpáramo, causing the apparent increase in tree pollen at high altitude. The association between increased forest pollen and summer insolation at this time suggests a causal link; however, further work is needed to clarify this relationship.

  12. TEORIA ECONOMICA I~nigo Iturbe-Ormaetxe

    E-print Network

    Escolano, Francisco

    TEORIA ECONOMICA I~nigo Iturbe-Ormaetxe Examen nal, 05/07/2011, curso 2010/11 Universidad de interpretacion a su valor usando el concepto de coste de oportunidad. 2. Una empresa fabrica un producto usando

  13. Latin American Theatre Review, Volume 29, Number 2: Book Reviews

    E-print Network

    1996-04-01

    en la comprensión de la estructura cíclica, ritualista, atemporal, en que la imaginación del lector es licitada y compelida a ofrecer interpretaciones simultáneas. En los cuatro dramas, en vez de leerse historias de amor, de celos, de incestos o de...

  14. Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Cintron Aponte, Rommel

    La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

  15. Seasonal inundation patterns in two large savanna floodplains of South America: the Llanos de Moxos(Bolivia) and the Llanos del Orinoco(Venezuela and Colombia)

    Microsoft Academic Search

    Stephen K. Hamilton; Suzanne J. Sippel; John M. Melack

    2004-01-01

    Inundation patterns in two of the largest savanna floodplains of South America were studied by analysis of the 37-GHz polarization difference observed by the Scanning Multichannel Microwave Radiometer (Nimbus-7 satellite). Flooded area was estimated at monthly intervals for January 1979 through to August 1987 using mixing models that account for the major landscape units with distinctive microwave emission characteristics. Results

  16. Development of techniques to simplify the process of investigation and estimate of natural resources in remote and relatively unexplored areas, Venezuela

    NASA Technical Reports Server (NTRS)

    Romero, A. C. (principal investigator)

    1976-01-01

    The author has identified the following significant results. Based upon the results obtained by both interpretations, radar and satellite, highly fractured zones were outlined and checked against geologic rock samples. Most of the rock samples were collected along the Ventuari River that crosses most of the project area from NE to SE. The structural orientation and fracture patterns were taken into consideration during the planning of flight lines, also the magnetic declination of the area. Most of the flight lines were oriented N 30 deg W across known structural trends; the altitude above ground was 450 feet, and the distance between lines was 3000 feet. The ERTS image permits the obtention of a panoramic vision of the area, and facilitates the exact delineation of major drainages. Topographic changes are easily observed. Rocky outcrops are easily distinguishable on band 5 and 7. Shrub vegetation zones are distinguishable on both bands, without possible separation of forest types, this is possible only when the physiographic conditions of small textural differences are taken into account.

  17. Chronostratigraphy and biofacies of the middle Eocene Paguey Formation: An invaluable tool for hydrocarbon exploration in the Barinas basin, western Venezuela

    SciTech Connect

    Crespo De Cabrera, S.; Di Gianni, N.; Arnstein, R. [Laboratorio Geologico, Corpoven, S.A., Puerto La Cruz (Venezuela)] [and others

    1996-08-01

    Paleoenvironmental changes within the Paguey Formation gave rise to foraminiferal assemblages which can be used for reservoir depth prognosis and subsurface correlation. The chronostratigraphic framework is provided by the integration of palynological, foraminiferal and calcareous nannoplankton data. The interval spans approximately from 43.0 Ma to 39.4 Ma. A transgressive-regressive second order cycle can be interpreted, since a very rapid deepening takes place at the base, where paleoenvironments vary from middle neritic in the south, to bathyal in the north. Within the lower half of the unit, a gradual filling of the basin begins, with paleoenvironments becoming progressively shallower toward the top of the unit. This formation is a 660-m-thick stratigraphic unit, composed mainly of dark gray mudstones, with fine grained glauconitic sandstones toward the base. It conformably overlies the middle Eocene Gobemador Formation and unconformably underlies the Parangula Formation. The characteristic biofacies are constituted by: Planktic zone (T robri/Globigerina sp.), Nummulites sp., Eggerella/Textularia, Quinqueloculina seminula, Ammobaculites/pteropods. The Nummulites sp. biofacies constitutes the most useful marker, since it extends across the whole basin. From the top of this zone to the top of the reservoir, a thickness of about 50 m in the south to 170 m in the north is observed. The precise prognosis of the reservoir depth is essential during the course of the drilling phase, in order to get the maximum geological information from cores at the lowest economic cost.

  18. Optimal oil recovery strategies in Miocene transgressive-barrier, coastal-plain, and mixed-load fluvial systems in the Mioceno Norte Area, Lake Maracaibo, Venezuela

    SciTech Connect

    Ambrose, W.A.; Wang, F.P.; Akhter, M.S.; Skolnakorn, J. [Univ. of Texas, Austin, TX (United States)] [and others

    1996-08-01

    Miocene oil reservoirs in the 30-km{sup 2} Mioceno Norte area are estimated to have a recovery efficiency of only 27 percent at the end of primary recovery operations at the current 40-acre well spacing. Although this area has produced oil since the 1930s, appreciable volumes of oil remain in multiple, poorly contacted reservoir compartments. Strategic development of these compartments could improve ultimate recovery up to an additional 15 to 20 percent of the original oil in place. Multiple Miocene regressive-transgressive episodes in the Maracaibo Basin resulted in a complex reservoir architecture. Basal Miocene fluvial deposits, deposited during a forced regression, are overlain by shelf and transgressive barrier-island deposits of a highstand systems tract. Episodes of upper Miocene fluvial and lacustrine-fill deposits, bounded by continuous paleosol marker beds, record climate changes or intermittent tectonic activity resulting in reorganization of dip-dispersal systems. We used an integrated reservoir-characterization program incorporating structural, stratigraphic, seismic, palynological, petrophysical, petrographic, petroleum-engineering, and volumetric analyses to target areas for strategic oil recovery. Remaining oil is inferred to occur mainly in narrow (less than 2000 in wide), uncontacted or poorly contacted fluvial-and distributary-channel sandstones commonly projected between existing well spacing. Additional remaining oil exists in tidal-channel and backbarrier areas where washover-fan sandstones pinch out into muddy lagoonal-fill deposits.

  19. Chemistry and mineralogy of natural bitumens and heavy oils and their reservoir rocks from the United States, Canada, Trinidad and Tobago, and Venezuela

    USGS Publications Warehouse

    Hosterman, John W.; Meyer, R.F.; Palmer, C.A.; Doughten, M.W.; Anders, D.E.

    1990-01-01

    Twenty-one samples from natural bitumen and heavy oil deposits in seven States of the United States and six samples from outside the United States form the basis of this initial study. This Circular gives the mineral content of the reservoir rock, the trace-element distribution in the reservoir rock and hydrocarbons, and the composition of the heavy oil and natural bitumen. The reservoir rock and sediment residues from California contain more trace-element maximum amounts than any of the other rock samples. These relatively high concentrations of trace elements may be due, in part, to the low quartz content of the rock and to the presence of heulandite, cristobalite, siderite, and pyrite. The reservoir rock and sediment residues from Oklahoma contain more minimum amounts of trace elements than any of the other rock samples. This pattern probably results from the large amount of quartz in four of the samples and a large amount of calcite in the other sample. The maximum and minimum amounts of trace elements in the bitumen and heavy oil do not correlate with those in the reservoir rocks. The bitumen from Utah contains the greatest number of trace-element maxima, whereas there is no trend in the trace-element minima in the bitumen and heavy oil.

  20. The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela

    PubMed Central

    Gutiérrez, Eliécer E.; Maldonado, Jesús E.; Radosavljevic, Aleksandar; Molinari, Jesús; Patterson, Bruce D.; Martínez-C., Juan M.; Rutter, Amy R.; Hawkins, Melissa T. R.; Garcia, Franger J.; Helgen, Kristofer M.

    2015-01-01

    We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics. PMID:26121688

  1. 3-D structural and seismic stratigraphic interpretation of the Guasare-Misoa Interval, VLE 196 Area, Block V, Lamar Field, Lake Maracaibo, Venezuela 

    E-print Network

    Arzuman, Sadun

    2004-09-30

    In this study, the structure, depositional system, and the seismic stratigraphy of the VLE 196 area, Block V in Lamar Field were interpreted using 3-D seismic data and well logs to characterize structural and depositional settings of the Guasare...

  2. Annual tree rings revealed by radiocarbon dating in seasonally flooded forest of the Mapire River, a tributary of the lower Orinoco River, Venezuela

    Microsoft Academic Search

    Nelda Dezzeo; Martin Worbes; Iria Ishii; Rafael Herrera

    2003-01-01

    The occurrence of seasonal growth rings in the wood of Campsiandra laurifolia, Acosmiun nitens, Pouteria orinocoensis and Psidium ovatifolium, common species growing in the flooding forest of the Mapire river, was analyzed using wood anatomy and ring- width analysis. The test of the annual ring formation was performed using radiocarbon analysis based on the nuclear weapon effect. All species showed

  3. 3-D structural and seismic stratigraphic interpretation of the Guasare-Misoa Interval, VLE 196 Area, Block V, Lamar Field, Lake Maracaibo, Venezuela

    E-print Network

    Arzuman, Sadun

    2004-09-30

    In this study, the structure, depositional system, and the seismic stratigraphy of the VLE 196 area, Block V in Lamar Field were interpreted using 3-D seismic data and well logs to characterize structural and depositional settings of the Guasare...

  4. Variations in organic facies and sedimentary environments of the La Luna Formation and Machiques Member in the Perija Mountain Range, Venezuela

    SciTech Connect

    Escandon, M.; Vallejos, C. (Intevep S.A., Los Teques (Venezuela)); Pratt, L. (Indiana Univ., Bloomington (United States)); Gambino, F.Y. (Intevep, Los Teques (Venezuela))

    1993-02-01

    In a detailed geochemical study of core samples from four oil wells and outcrop samples from four sections, the vertical and areal variations of organic facies within the main source rocks in the western part of the Maracaibo Basin have been performed. In addition, oils and oil seeps of the basin have been geochemically correlated to each one of these facies. Based on geochemical and micropaleontological data, two organic facies related to variations in sedimentary environment are recognized in the La Luna Formation (Cenomanian-Santonian). The sulphur richer organic facies includes the Cenomanian intermiddle shales and the shales from the Cenomanian-Turonian boundary, both characterized by higher values of total organic carbon, bitumen, hydrogen index and benzotiophenes content. This facies probably is an earlier generation source rock than the rest of the La Luna Formation and its correlation with crude-oils indicates that most of the crudes display a distribution of hopane and sulphur aromatic compounds typical of these more anoxic facies. Within the Machiques Member of the Apon Formation (Aptian), two organic/lithological facies have been identified. These are transgressive basal shales and the overlying regressive mudstones with an upward decrease in hydrocarbon potential, anoxia and paleobathymetry. This member presents no benzotiophenes and differences in the relationships between terpanes and aromatic hydrocarbons which allow us distinguish it from La Luna Formation extracts. This is a powerful technique to recognize the genesis of crude oils derived from a particular marine source rock interval in the Maracaibo Basin.

  5. Deposition of sediments during a flood event on seasonally flooded forests of the lower Orinoco River and two of its black-water tributaries, Venezuela

    Microsoft Academic Search

    N. Dezzeo; R. Herrera; G. Escalante; N. Chacón

    2000-01-01

    Deposition of suspended sediments andtheir associated nutrients were estimated during theflood event of 1995 in the seasonally flooded forestsof the Mapire and Caura Rivers, two black-watertributaries of lower Orinoco, and on two islands ofthis white-water river. The deposition spanned a widerange from 0.07 kg m-2 in the depositional barforests of the Mapire River to 73.60 kg m-2 onthe flooded forests

  6. Spanish-Hispanic Culture from A to V (Actualidades to Venezuela): 72 Spanish-Language Interdisciplinary Cultural Themes with Suggested Resource Materials and Activities.

    ERIC Educational Resources Information Center

    Moore, Merriam M.

    This guidebook is intended for use by teachers of Spanish (FLES through college level) and by teachers in Spanish bilingual programs. It lists all of the Spanish-speaking countries and 72 Spanish-language cultural themes, such as "Actualidades" (Current Events), "Carreras y espanol comercial" (Careers and Commercial Spanish), "Deportes" (Sports),…

  7. [Helicobacter pylori infection (13C-UBT), and its relationship with nutritional and socioeconomic factors in low income school children from Valencia, Venezuela].

    PubMed

    Páez Valery, M C; Barón, M A; Solano, L; Nadaff, G; Boccio, J; Barrado, A

    2006-12-01

    Helicobacter pylori infection (Hp) is widely spread around the world, and it is considered one of the main causes of chronic gastritis, peptic and duodenal ulcers, and gastric cancer. Recent research has shown that it can be associated with nutritional disorders, mainly with iron and other micronutrient deficiencies. The objective of this study was to assess the prevalence of Hp infection, and infection pattern according to age, sex, nutritional status, and socioeconomic conditions in children who attended the Unidad Educativa "Valentin Espinal" in the city of Valencia. 170 children, between 3 and 14 years of age were studied to assess Hpylori infection (13C-urea breath test), age, nutritional status according to BMI and Height for age, hemoglobin (cianometahemoglobin), serum ferritin (ELISA), socioeconomic status (Graffar-Méndez-Castellano), housing conditions, number of families and of people cohabitating in the same household, and quality of services. 78.8% of the children were infected with Hp, witch was significantly correlated with age but not gender. 25.9% of the sample had undernutrition, and 46.5% were stunted. 98.1% of the families lived in poverty, and 98% of the households showed sanitary deficiencies. A mean of 6.0 +/- 2.4 persons lived in each household (range: 2-15), and an average of 3.2 person shared bedrooms. The odds of being infected were higher in those children who were stunted. Also, socioeconomic status, mother's education level, and poor hosing conditions were significantly associated to being infected. Hpylori is highly prevalent among socially and economically deprived children, and age, overcrowding, and a low education level of the mother increases the risk of being infected. PMID:17425179

  8. The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela.

    PubMed

    Gutiérrez, Eliécer E; Maldonado, Jesús E; Radosavljevic, Aleksandar; Molinari, Jesús; Patterson, Bruce D; Martínez-C, Juan M; Rutter, Amy R; Hawkins, Melissa T R; Garcia, Franger J; Helgen, Kristofer M

    2015-01-01

    We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics. PMID:26121688

  9. Using shell middens to assess effects of fishing on queen conch ( Strombus gigas ) populations in Los Roques Archipelago National Park, Venezuela

    Microsoft Academic Search

    Diego Schapira; Irene A. Montaño; Andrzej Antczak; Juan M. Posada

    2009-01-01

    Queen conch, Strombus gigas, is a commercially important gastropod that has been exploited throughout the Caribbean islands for thousands of years. Shell\\u000a middens in the region are the physical record of a long-term fishery and their study can provide valuable information on selectivity\\u000a patterns followed by fishermen and on resulting morphological shifts reflected by shells. In this study, we surveyed

  10. Trench investigation on the main strand of the Boconó fault in its central section, at Mesa del Caballo, Mérida Andes, Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard M., Franck A.; Ollarves, Reinaldo; Bechtold, Michel; Díaz, Gustavo; Beck, Christian; Carrillo, Eduardo; Pantosti, Daniela; Diederix, Hans

    2008-11-01

    The Mesa del Caballo trench assessment confirms the Holocene activity of the main strand of the Boconó fault at the Apartaderos pull-apart basin. Fifteen earthquakes, of which fourteen have been radiocarbon dated, have been recognized, spanning the last 20,500 yr. Recurrence intervals of these ? 7 magnitude events are variable. The dominant mode of recurrence is 400-450 yr, and the second one is 900 yr. Eventually some events are 1400-1800 yr apart. We suspect that our seismic record may be incomplete. This could be easily justified by several conditions: most of the earthquake recognitions is based on open-crack filling and they superpose spatially (eventually masking or destroying older fills), trenching may miss some events because the fault is made of en echelon Riedel shears, and a short return period may lead to faint differences between paleosoils few hundreds years of age apart. This trench also images an older activity of the fault, as evidenced by plentiful earthquake-triggered liquefaction features, as well as slumping and rotational sliding. By comparing paleoseismic results between the Morro de Los Hoyos and Mesa del Caballo trenches, it appears that both fault strands bounding the Apartaderos pull-apart basin move simultaneously. Besides, the main strand also coseismically slips twice in between those common events. In other words, the seismic scenario could be that the northern strand recurs every 1200-1350 yr while the southern does every 400-450 yr. This is also in agreement with a respective slip share of 25 and 75% of the 9-10 mm/yr average slip of the Boconó fault in the Mérida Andes central sector.

  11. XXII CONGRESO LATINOAMERICANO DE HIDRÁULICA CIUDAD GUAYANA, VENEZUELA, OCTUBRE 2006 SISTEMA DE AYUDA A LA TOMA DE DECISIONES PARA EVALUACIÓN Y GESTIÓN DEL RIESGO DE INUNDACIÓN

    Microsoft Academic Search

    Javier Piazzese; Georgina Corestein; Eugenio Oñate

    A new decision support system (DSS) for the risk assessment and management of emergency scenarios due to severe floods was created. The DSS combines environmental and geo- physical data from earth observation, with advanced computer simulation, graphical visualization methods and artificial intelligence techniques, for generating useful knowledge contributing to the flood risk prevention. The aim of the RAMFLOOD project is

  12. La gestión de riesgo en Venezuela y América Latina, su representación cartográfica y la potencial proyección de una geografía con alcance social

    Microsoft Academic Search

    Scarleth Coromoto Mujica

    2010-01-01

    Actualmente, son muchas las investigaciones en geografía que inclinan su interés hacia la producción de mapas de riesgo, teniendo como soporte el registro de sucesos y episodios ocurridos, para proyectar modelos de susceptibilidad y amenaza. Se considera interesante el desarrollo de estas investigaciones, pero aún no se logra un nivel deseado ya que el riesgo ambiental es un problema no

  13. LA PARTICIPACIÓN CIUDADANA: ACCIÓN LOCAL NECESARIA PARA LA GESTIÓN DE RIESGO EN UN MUNICIPIO PERTENECIENTE AL ÁREA METROPOLITANA DE CARACAS, VENEZUELA

    Microsoft Academic Search

    Yenny Del Carmen Jiménez Vallenilla

    2011-01-01

    La vulnerabilidad, específicamente en el ámbito social, se ha constituido en un aspecto importante para América Latina, debido a la gran preocupación mostrada tanto de gobiernos y organismos internacionales como de organizaciones políticas, sociales, religiosas y educativas, en torno a las amenazas ambientales. Estas instituciones proponen, diseñan, investigan, ejecutan y aportan recursos y estrategias que contribuyan a la reducción de

  14. Effect of Tillage and Non-tillage Agricultural Practice on Nitrogen Losses as NO and N2O in Tropical Corn Fields at Guarico State, Venezuela.

    NASA Astrophysics Data System (ADS)

    Marquina, S.; Rojas, A.; Donoso, L.; Rasse, R.; Giuliante, A.; Corona, O.; Perez, T.

    2007-12-01

    We evaluated the effect of agricultural practices on NO and N2O emissions from corn fields at Northern Guárico, one of Venezuelan largest cereal production regions. Historically, the most common agricultural practice in these regions has been mono cropping. Tillage (T) and non-tillage (NT) of soils represent approximately 30 and 70% of the planted area, respectively. Comparative studies of the nitrogen losses associated with these agricultural practices are not available for these regions. This study was conducted at the farm "Tierra Nueva", Guárico State (9° 23' 33'' N, 66° 38' 30'' W) in two corn fields under tillage and non-tillage agricultural practice during the growing season (June-August 2006). A dry tropical forest, the primary ecosystem of the region, was evaluated for the same period of time. The corn and the forest fields were adjacent; therefore, they were exposed to the same meteorological conditions. The mean annual precipitation of the area is 622±97.3 mm (last 5 years). The soils are Vertisols (Typic Haplusterts). Nutrient soil concentrations (as nitrate and ammonium), water soil content and pH soil were measured in the fields for the same period of time. Soils were fertilized and planted simultaneously by a planting machine provided with a furrow opener where the fertilizer and seeds are incorporated between 0-10 cm depths. Tillage soils were fertilized on June 1st 2006 with 65 kgN/ha of NPK (13:18:16/3MgO, 3S; N as NH4Cl), whereas non-tillage soils were fertilized the next day with 56 kgN/ha of NPK (12:25:12/3MgO, 3S; N as NH4Cl). Second fertilization of both fields was done thirty-seven days later by broadcast adding 58 kgN/ha approximately, using nitrophosphate as fertilizer (NP 33-3: 33% N total; 16.7% N- NO3- and 16.6% N- NH4+). In general, NO and N2O soil emissions from both corn fields increased after fertilization events, and depend on water soil content and nutrient soil concentration. N2O soil emissions were 11 and 9 times larger in comparison to the forest values for the 60-day evaluation period for NT and T, respectively. On the other hand, NO soil emissions were 1.5 and 5 times larger in NT and T fields, respectively, in comparison to forest values. The fertilizer-induced emissions factors (FEI) for NO and N2O show that the nitrogen gaseous losses are mostly in the form of N2O for NT (NO-FEI = 0.2% and N2O-FEI=3.6%) and T (NO-FEI=1.7% and N2O- FEI=2.8%) practices. However, NO losses are higher in T than NT soils, probably due to the higher porosity in the former that promotes NO production under aerobic conditions. These results imply that tillage agricultural practice leads to a higher stimulation of these nitrogen gaseous emissions than non-tillage agricultural practice. Our N2O-FEI values for direct emissions are higher than the proposed by the IPPC national guidelines 2006 (FEI = 1%, Volume 4, Chapter 11). This implies that tropical agroecosystems are more susceptible to increase emissions after fertilization than temperate regions. Our results will be used to produce better estimates of direct N2O emissions from tropical agriculture and improve the current Venezuelan national greenhouse gas inventory.

  15. Biochemical genetics of chromosome forms of Venezuelan spiny rats of the proechimys guairae and proechimys trinitatis superspecies

    Microsoft Academic Search

    M. Benado; M. Aguilera; O. A. Reig; F. J. Ayala

    1979-01-01

    Spiny rats from Venezuela show an extensive karyotypic diversification (2n=24 to 2n=62) and little morphological differentiation. This study reports genetic distance, heterozygosity and polymorphism based upon 22 loci in semispecies and allospecies of the Proechimys guairae superspecies from N Central Venezuela, as compared with Proechimys urichi, a member of the Proechimys trinitatis superspecies from eastern Venezuela. Four chromosome forms of

  16. LA PRODUCCIÓN AGROPECUARIA COLOMBIANA 1915-1950

    Microsoft Academic Search

    Salomón Kalmanovitz; Enrique López E; Carmen Astrid Romero B

    1999-01-01

    Son escasos los estudios sobre el desarrollo económico colombiano que abarquen la primera mitad del siglo XX . A excepción de los trabajos sobre la economía del café y el surgimiento del proceso de industrialización durante los años veinte y treinta, casi todas las interpretaciones sobre el desempeño de la economía real parten de 1950. En el caso del sector

  17. Esbs de soluci a l'examen d'IAT (01.02.03) 1. [un punt per frase, puntuada sobre 8

    E-print Network

    Forcada, Mikel L.

    /verb), "droga" (nom/verb)". De les setze interpretacions, n'hi ha dues sintàcticament vàlides: 1: det n pron v 2: pron v det n g) Ambigüitat lèxica per anàfora: el pronom relatiu "que" pot tenir dos antecedents: el SN

  18. Los testigos de Jehová y el consentimiento informado

    Microsoft Academic Search

    Pimentel Pérez; Hospital General de Zona; Calzada Benito Juárez

    RESUMEN Los testigos de Jehová son una joven asocia- ción religiosa mundial dirigida por Watchtower Society de Nueva York, cuyos preceptos es- tán fundamentados ad pedem literae en la Bi- blia, pero con interpretaciones originales y connotaciones sectarias. La prohibición a ser transfundidos es una norma propia, actualmente vigente y que los distingue, condicionando anta- gonismos con el área médica.

  19. Erasmus Mundus Action 2 Strand 1 PROJECT SUMMARY SHEET

    E-print Network

    Schenato, Luca

    de Chiriquí Panama Associate 29 Universidad Especializada de las Américas Panama Associate 30, Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Mexico, Panama, Uruguay, Venezuela Project duration

  20. NETHERLANDS SWITZERLAND

    E-print Network

    ANTILLES SAINT KITTS & NEVIS SAINT LUCIA BARBADOS SAINT VINCENT TRINIDAD & TOBAGO URUGUAY ECUADOR VENEZUELA GRENADA LESSER ANTILLES SAINT KITTS & NEVIS SAINT LUCIA BARBADOS SAINT VINCENT TRINIDAD & TOBAGO URUGUAY

  1. International Enrollment: Fall 2010 and South Middle North

    E-print Network

    , Mauritius, Morocco, Namibia, Rwanda, Senegal, Sierra Leone, Sudan, Swaziland, Tanzania, Tunisia, Uganda, Venezuela. Middle East Other: Afghanistan, Bahrain, Iraq, Jordan, Kuwait, Syria, United Arab Emirates West

  2. Drilling optimization using drilling simulator software 

    E-print Network

    Salas Safe, Jose Gregorio

    2004-09-30

    Simulation control sheet shows numerical simulation results ....................................35 18 Geographical location of the Bosque field, Venezuela...............................................36 19 Genesis of the Pirital?s landslide, Bosque field...

  3. Strategic Global Alliances in Vaccine Development and Disease Control

    E-print Network

    Maizels, Rick

    , Colombia, Venezuela and Bolivia) and regional organisations. Asia and Austral-Asia Regional Network, communication and dissemination WP2: Sharing information on existing research programmes WP3:Analysis

  4. Mercury levels in coral reefs along the Caribbean coast of Central America

    E-print Network

    Bermingham, Eldredge

    Departamento de Biologiia de Organismos, Universidad Simoon Boliivar, Apdo. 89000, Caracas 1080-A, Venezuela is affected by trace metals released into the environment from extensive deforestation, agricul- tural

  5. SmallholderSmallholder CarbonCarbon AgroforestryAgroforestry && Carbon for Poverty ReductionCarbon for Poverty Reduction

    E-print Network

    Founding Institutions (2004) 6 NARIs (INIAs) Inia (Brasil) (Colombia) (Peru) (Bolivia) (Ecuador) (Venezuela #12;Sustainable smallholderSustainable smallholder production on deforested /production on deforested

  6. La comunicación en la construcción teórica de la realidad educativa carcelaria de la mujer wayuu. Caso: Anexo Femenino de la Cárcel Nacional de Maracaibo-Zulia-Venezuela (AF-CNM)

    Microsoft Academic Search

    Javier Castillo Briceño

    Resumen La generación de una aproximación teórica de una realidad observada se justifica, en una instancia particular de los investigadores, cuando a partir de una metametodología se intenta reorganizar a los sujetos de estudio situados en un contexto que, desde disímiles ángulos, es complejo de entender. En esta ponencia, de una investigación cualitativa-fenomenológica con un componente etnográfico y un criterio

  7. Trace-element deposition in the Cariaco Basin, Venezuela Shelf, under sulfate-reducing conditions: a history of the local hydrography and global climate, 20 ka to the present

    USGS Publications Warehouse

    Piper, David Z.; Dean, Walter E.

    2002-01-01

    A sediment core from the Cariaco Basin on the Venezuelan continental shelf, which recovered sediment that has been dated back to 20 ka (thousand years ago), was examined for its major-element-oxide and trace-element composition. Cadmium (Cd), chromium (Cr), copper (Cu), molybdenum (Mo), nickel (Ni), vanadium (V), and zinc (Zn) can be partitioned between a siliciclastic, terrigenous-derived fraction and two seawater-derived fractions. The two marine fractions are (1) a biogenic fraction represented by nutrient trace elements taken up mostly in the photic zone by phytoplankton, and (2) a hydrogenous fraction that has been derived from bottom water via adsorption and precipitation reactions. This suite of trace elements contrasts with a second suite of trace elements—barium (Ba), cobalt (Co), gallium (Ga), lithium (Li), the rare-earth elements, thorium (Th), yttrium (Y), and several of the major-element oxides—that has had solely a terrigenous source. The partitioning scheme, coupled with bulk sediment accumulation rates measured by others, allows us to determine the accumulation rate of trace elements in each of the three sediment fractions and of the fractions themselves. The current export of organic matter from the photic zone, redox conditions and advection of bottom water, and flux of terrigenous debris into the basin can be used to calculate independently trace-element depositional rates. The calculated rates show excellent agreement with the measured rates of the surface sediment. This agreement supports a model of trace-element accumulation rates in the subsurface sediment that gives a 20-kyr history of upwelling into the photic zone (that is, primary productivity), bottom-water advection and redox, and provenance. Correspondence of extrema in the geochemical signals with global changes in sea level and climate demonstrates the high degree to which the basin hydrography and provenance have responded to the paleoceanographic and paleoclimatic regimes of the last 20 kyr. The accumulation rate of the marine fraction of Mo increased abruptly at about 14.8 ka (calendar years), from less than 0.5 µg cm-2 yr-1 to greater than 4 µg cm-2 yr-1. Its accumulation rate remained high but variable until 8.6 ka, when it decreased sharply to 1 µg cm-2 yr-1. It continued to decrease to 4.0 ka, to its lowest value for the past 15 kyr, before gradually increasing to the present. Between 14.8 ka and 8.6 ka, its accumulation rate exhibited strong maxima at 14.4, 13.0, and 9.9 ka. The oldest maximum corresponds to melt-water pulse IA into the Gulf of Mexico. A relative minimum, centered at about 11.1 ka, corresponds to melt-water pulse IB; a strong maximum occurs in the immediately overlying sediment. The maximum at 13.0 ka corresponds to onset of the Younger Dryas cold event. This pattern to the accumulation rate of Mo (and V) can be interpreted in terms of its deposition from bottom water of the basin, the hydrogenous fraction, under SO42- -reducing conditions, during times of intense bottom-water advection 14.8 ka to 11.1 ka and significantly less intense bottom-water advection 11 ka to the present. The accumulation rate of Cd shows a pattern that is only slightly different from that of Mo, although its deposition was determined largely by the rain rate of organic matter into the bottom water, a biogenic fraction whose deposition was driven by upwelling of nutrient-enriched water into the photic zone. Its accumulation exhibits only moderately high rates, on average, during both melt-water pulses. Its highest rate, and that of upwelling, occurred during the Younger Dryas, and again following melt-water pulse IB. The marine fractions of Cu, Ni, and Zn also have a strong biogenic signal. The siliciclastic terrigenous debris, however, represents the dominant source, and host, of Cu, Ni, and Zn. All four trace elements have a consid-erably weaker hydrogenous signal than biogenic signal. Accumulation rates of the terrigenous fraction, as reflected by accumulation rates of Th and Ga, show strong maxima at 16.2 and 12.7 ka and minima a

  8. Conference of Ministers of Education and Those Responsible for the Promotion of Science and Technology in Relation to Development in Latin America and the Caribbean Convened in Cooperation with ECLA and OAS, Venezuela, December 1971, Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    Summarized in this report are commission reports, resolutions, and recommendations offered to a 1971 UNESCO conference dealing with education, science, technology, and development in Latin America and the Caribbean. The narrative material serves to illuminate the Conference objectives to: (1) review the progress made in education since a 1966…

  9. Seminario Tecnico Regional Sobre Alternativas de Educacion Basica de Adultos en el Marco de la REDALF del Proyecto Principal de Educacion en America Latina y el Caribe (Colonia Tovar, Venezuela, 29 de Septiembre al 3 de Octubre, 1986). Documento Final. (Regional Seminar on Alternatives for Basic Adult Education in the REDALF Project for Education in Latin America and the Caribbean (Colonia Tovar, Venezuela, September 29-October 3, 1986). Final Document.)

    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 final report of a conference concerning adult basic education de Adultos en el Marco de la REDALF del related to innovative projects in adult education in nine countries. A wide spectrum of issues related to adult basic education, curriculum, methodology, evaluation, and research are analyzed in the context of educational planning. Among the…

  10. Neotype designation and a diagnostic account for the centipede, Scolopendra gigantea L. 1758, with an account of S. galapagoensis Bollman 1889 (Chilopoda Scolopendromorpha Scolopendridae)

    Microsoft Academic Search

    R. M. Shelley; S. B. Kiser

    2000-01-01

    The oldest species-group name in the chilopod order Scolopendromorpha and family Scolopendridae, Scolopendra gigantea Linnaeus 1758, is stabilized in accordance with the current concept by designating a neotype specimen from northern Venezuela. The species occurs in northern Colombia and Venezuela, and on Trinidad, Isla Margarita, Curaçao, and Aruba; records from the US Virgin islands, Haiti, Mexico, and Honduras are deemed

  11. The Yanomami in the Face of Ethnocide. IWGIA Document 22.

    ERIC Educational Resources Information Center

    Lizot, Jacques

    Spread between Brazil and Venezuela, the Yanomami occupy a dense forest region on the borders of Guyana, the northern parts divided up by grassy savanna. The Parima plain which forms the frontier between Brazil and Venezuela constitutes both the geographic centre and the place of origin of today's communities. The linguistic affiliation of these…

  12. LA INESTABILIDAD DEMOCRTICA EN LA AMRICA DEL SIGLO XXI: LOS CASOS DE ARGENTINA Y Joo Carlos AMOROSO BOTELHO

    E-print Network

    Paris-Sud XI, Université de

    Venezuela, consideradas en el pasado reciente naciones con modelos de sistemas bipartidistas, entraron en Argentina y Venezuela, consideradas en el pasado reciente naciones latinoamericanas con modelos de sistemas hipótesis es que multipartidismo y gobierno de coalición, que diferencian el sistema político brasileño del

  13. NOAA Technical Report NMFS 151 A Technical Report of the Fishery Bulletin

    E-print Network

    NOAA Technical Report NMFS 151 A Technical Report of the Fishery Bulletin Cetaceans of Venezuela.­Sighting, stranding, and cap ture records of whales and dolphins for Venezuela were assembled and analyzed to document global and local distribu tion, conservation status and threats, and the common names used, along

  14. State of the Modern Information Professional, 1992-1993. An International View of the State of the Information Professional and the Information Profession in 1992-1993. FID Occasional Paper 4.

    ERIC Educational Resources Information Center

    International Federation for Information and Documentation, The Hague (Netherlands).

    The following 14 papers are provided: (1) "Perfil del profesional de la informacion en Venezuela" with a synopsis in English: "Profile of the Information Professional in Venezuela" (A. D. Anton and M. S. de Arenas); (2) "The Modern Information Professional in the Caribbean Setting" (D. Douglas); (3) "Development of Information Professionals and…

  15. Original article Sugar profiles and conductivity of stingless bee

    E-print Network

    Boyer, Edmond

    Original article Sugar profiles and conductivity of stingless bee honeys from Venezuela S Bogdanov, Venezuela (Received 12 March 1996; accepted 27 July 1996) Summary — The HPLC sugar profiles sugars of the Melipona honeys were fructose and glucose, with an average of 36.7 g/100 g. The Trigona

  16. PROCEEDINGS OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA 158: 183-192 APRIL 2009 INTRODUCTION

    E-print Network

    Hopkins, Carl D.

    produce weak electric impulses for the purposes of electro- location and communication. Hypopomids of Colombia and Venezuela and the rio Negro basin of Brazil and Guyana. Brachyhypopomus is one of seven genera of Colombia and Venezuela as well as the Takutu River/rio Branco-rio Negro basin of Guyana and Brazil. Among

  17. 1. Background What is the fate of the Amazon under climate change?

    E-print Network

    Saleska, Scott

    -induced drought (Markewitz et al., 2010; Brando et al., 2008) Venezuela 1 0 ° 1 0 ° Amazon forests Mean annual $ $ $$$ $ $ $ JAV K34 K77 RJA FNS K67 K83 CAX Colombia Venezuela Guyana Surinam French Guyana Brasil Peru Ecuador 1" of the Amazon forest:forest: p p y driver of current tropical deforestation) 2 Climate change drought Evapo

  18. The Establishment of an Operational Earthquake Forecasting System in Italy

    NASA Astrophysics Data System (ADS)

    Marzocchi, Warner; Lombardi, Anna Maria; Casarotti, Emanuele

    2014-05-01

    Just after the Mw 6.2 earthquake that hit L'Aquila, on April 6 2009, the Civil Protection nominated an International Commission on Earthquake Forecasting (ICEF) that paved the way to the development of the Operational Earthquake Forecasting (OEF), defined as the "procedures for gathering and disseminating authoritative information about the time dependence of seismic hazards to help communities prepare for potentially destructive earthquakes". In this paper we introduce the first official OEF system in Italy that has been developed by the new-born Centro di Pericolosità Sismica at the Istituto Nazionale di Geofisica e Vulcanologia. The system provides every day an update of the weekly probabilities of ground shaking over the whole Italian territory. In this presentation, we describe in detail the philosophy behind the system, the scientific details, and the output format that has been preliminary defined in agreement with Civil Protection. To our knowledge, this is the first operational system that fully satisfies the ICEF guidelines. Probably, the most sensitive issue is related to the communication of such a kind of message to the population. Acknowledging this inherent difficulty, in agreement with Civil Protection we are planning pilot tests to be carried out in few selected areas in Italy; the purpose of such tests is to check the effectiveness of the message and to receive feedbacks.

  19. Efficiency as Applied to Cotton Ginning Business. 

    E-print Network

    Paulson, W. E. (William E.)

    1944-01-01

    Recent political trends in Latin America have led to the election of a number of leftist presidents throughout the region. Some, such as Venezuela's Hugo Chavez and Ecuador's Rafael Correa, profess goals centered to varying ...

  20. U.S. Department of the Interior U.S. Geological Survey

    E-print Network

    Laughlin, Robert B.

    of the Orinoco Oil Belt Assessment Unit (blue line); the La Luna­Quercual Total Petroleum System and East PACIFIC OCEAN ATLANTIC OCEAN SOUTH AMERICA East Venezuela Basin Province EXPLANATION Orinoco Oil Belt