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Astronomy in Venezuela  

Microsoft Academic Search

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

Patricia Rosenzweig



[Immigration to Venezuela].  


Immigration to Venezuela is examined using census data with the focus on the period 1971-1981. A brief overview of trends since the beginning of the twentieth century is first presented. The analysis indicates that "immigration to Venezuela is clearly of a short-term nature. Flows follow job opportunities and adjust to the labour market and to the financial capacity of the exchange market. The large increase of migratory movements to Venezuela in the 1970's is characterized by a diversification of their places of origin and by a greater instability. To a large extent, the migrants are illegal, especially those coming from Colombia and the Caribbean islands. Because of the crisis of the early 1980's, which is now worsened by the down trend of both oil prices and the U.S. dollar, Venezuela has become less attractive to immigrants, particularly from neighbouring countries." The authors observe that migrants in Venezuela are not well integrated and may depart, disrupting the labor supply in certain technical and specialized occupations (SUMMARY IN ENG AND SPA) PMID:12341015

Picouet, M; Pellegrino, A; Papail, J



Venezuela`s gas industry poised for long term growth  

SciTech Connect

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

Croft, G.D. [Pantera Petroleum Inc., San Leandro, CA (United States)



Histoplasmosis en Venezuela  

Microsoft Academic Search

Resumen  Se hace un recuento de los principales trabajos que se han llevado a cabo en Venezuela sobre Histoplasmosis desde 1950 cuando\\u000a se comprobó la infección, siguiéndose comunicaciones que conducen a la organización de la Comisión Coordinadora para el Estudio\\u000a Nacional de las Micosis con el objeto de facilitar y standardizar los métodos de investigación en el campo.\\u000a \\u000a Se presenta una

J. I. Baldó; H. Campins; Carlos Ayala Páez



Criptococosis en Venezuela  

Microsoft Academic Search

Resumen  En Venezuela se han diagnosticado 24 casos de Criptococosis de los cuales 21 han muerto por Meningo-encefalitis; los tres\\u000a restantes presentaron formas circunscritas pulmonares que fueron tratadas por lobectomía (2 viven en aparente buen estado\\u000a de salud después de varios años de la resección y el tercero murió por causas differentes a esta enfermedad).\\u000a \\u000a Entre esta estadística hay dos niños

Alberto Angulo-Ortega; César Rodríguez; Gustavo García Galindo



Some Crustacea Copepoda from Venezuela  

Microsoft Academic Search

The study of 38 samples of aquatic fauna from Venezuela increased the number of known species here from 28 to 66. Fifteen new species for science are described. A list of Copepoda known from the other regions of South America is presented. From this list, it can be said that only 50% of the inland water Copepoda living actually in

B. H. Dussart



Purposeful Play in Rural Venezuela  

ERIC Educational Resources Information Center

Describes how children in rural Venezuela are trained in agricultural skills by the extended family. The highly organized training encourages play and exploration as important elements in familiarzing children with implements and methods of food production. It is suggested that rural school planners draw ideas from the rural family's educative…

Chesterfield, Ray



Media and Consumerism in Venezuela.  

ERIC Educational Resources Information Center

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

Martin, Richard; And Others



Venezuela. America = Las Americas [Series].  

ERIC Educational Resources Information Center

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

Toro, Leonor; Avery, Robert S.


Geothermal reconnaissance of northeastern Venezuela  

SciTech Connect

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

Urbani, F. (Universidad Central de Venezuela, Departamento Geologia, Centro de Documentacion de Informacion, Geotermica Nacional, Apartado 47028, Caracas 1041A (VE))



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

Federal Register 2010, 2011, 2012, 2013

...Review)] Silicomanganese From India, Kazakhstan, and Venezuela Determination On the...imports of silicomanganese from India, Kazakhstan, and Venezuela would be likely to lead...entitled Silicomanganese from India, Kazakhstan, and Venezuela: Investigation...



Hydrocarbon potential of Central Monagas, Eastern Venezuela Basin, Venezuela  

SciTech Connect

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

Barrios, F.; Daza, J.; Iusco, G. [Departamento de Geologia, Lagoven, S.A., Caracas (Venezuela)



Family Cluster of Mayaro Fever, Venezuela  

PubMed Central

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

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



An Energy Overview of Venezuela  

SciTech Connect

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




Heavy Water. A Production Alternative for Venezuela.  

National Technical Information Service (NTIS)

A survey of heavy water production methods is made. Main facts about isotopic and distillation methods, reforming and coupling to a Hydrogen distillation plant are presented. A feasibility study on heavy water production in Venezuela is suggested. (Atomin...



History of Aeronautical Medicine in Venezuela.  

National Technical Information Service (NTIS)

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 an...

D. R. Iriarte



An Example of Educational Transformation: Venezuela.  

ERIC Educational Resources Information Center

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)

Cirigliano, Gustavo F. J.



On the Weather of Venezuela: A Summary Report on the Venezuela Experiments of 1969 and 1972. (Sobre el Estado del Tiempo en Venezuela: Resumen del Estudio de los Experimentos Realizados en Venezuela en 1969 y 1972).  

National Technical Information Service (NTIS)

In the bilingual (Spanish and English) Technical Memo, On the Weather of Venezuela, the methodology and execution of the Venezuela meteorological and hydrological experiments of 1969 and 1972 are discussed first. Then the radiation balance and water balan...

H. Riehl



Venezuela slates second oil field revival round  

SciTech Connect

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

Not Available



The history of aeronautical medicine in Venezuela  

NASA Technical Reports Server (NTRS)

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.

Iriarte, D. R.



A Library Toy Project in Venezuela.  

ERIC Educational Resources Information Center

Describes a six-month experimental library program carried out in Venezuela that sought to develop a home alternative to regular preschool education by providing parents and other adults in the family with the means of teaching children academic and problem-solving skills required by school. (Author/JD)

deDearden, Carmen Diana



Promoting Vetiver Grass Technology in Venezuela  

Microsoft Academic Search

A two year project (1997-99) was conducted by the Sociedad Conservacionista Aragua (Sca) with financial and technical support of The Vetiver Network (TVN), and sponsored by other local institutions like the Aragua's State Secretary of the Environment and the Central University of Venezuela. Twelve workshops were organized and more than three hundred participants received training on vetiver grass technology (VGT).

Oscar S. Rodríguez


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

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…

Hoover, Gary


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


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

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



Plans to revive oil fields in Venezuela on track  

SciTech Connect

This paper reports on the three operating units of Venezuela's state owned oil company Petroleos de Venezuela SA which will begin receiving bids Feb. 28 from companies interested in operating 55 inactive oil fields in nine producing areas of Venezuela. Francisco Pradas, Pdvsa executive in charge of the program, the the company expects 88 companies or combines of foreign and domestic private companies to participate in the bidding. The program, announced last year, aims to reactivate production in marginal oil fields. It will involve the first direct participation by private companies in Venezuela's oil production since nationalization in 1976.

Not Available



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

Federal Register 2010, 2011, 2012, 2013

...Ferrosilicon From the Russian Federation and Venezuela: Postponement...on ferrosilicon from the Russian Federation (``Russia'') and Venezuela.\\1\\ The Initiation...See Ferrosilicon From the Russian Federation and Venezuela:...



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

Federal Register 2010, 2011, 2012, 2013

...Review)] Silicomanganese From India, Kazakhstan, and Venezuela; Institution of Five-Year...Orders on Silicomanganese From India, Kazakhstan, and Venezuela AGENCY: United States...orders on silicomanganese from India, Kazakhstan, and Venezuela would be likely to...



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

Federal Register 2010, 2011, 2012, 2013

...Review)] Silicomanganese From India, Kazakhstan, and Venezuela; Scheduling of Full...Orders on Silicomanganese From India, Kazakhstan, and Venezuela AGENCY: United States...orders on silicomanganese from India, Kazakhstan, and Venezuela would be likely to...



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

ERIC Educational Resources Information Center

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…

Nieto, Ruben D.; Henderson, Janet L.



Microsoft Academic Search

Potential areas for collecting the Vasconcellea Badillo genus in Venezuela In Venezuela the following wild species of Caricaceae have been reported: V. cundinamarcensis Badillo, V. cauliflora (Jacq.) A. DC., V. microcarpa subsp microcarpa (Jacq.) A. DC and V. microcarpa subsp pilifera (V.M. Badillo) V.M. Badillo (endemic of the Andean of Mérida and Lara States). V. cundinamarcensis represents a promissory material

Dilia Rodríguez; Carlos Marín; Hernando Quecan; Rafael Ortiz



Critical Pedagogy and Empowering in Teacher Education in Venezuela.  

ERIC Educational Resources Information Center

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

Chacon, Carmen T.; Alvarez, Luisa Cristina


Language Planning for Venezuela: The Role of English.  

ERIC Educational Resources Information Center

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

Kelsey, Irving; Serrano, Jose


Using the Five Themes of Geography to Teach about Venezuela.  

ERIC Educational Resources Information Center

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)

Sunal, Cynthia Szymanski; And Others



Venezuela in the caribbean: expanding its sphere of influence  

Microsoft Academic Search

In the wake of deteriorating relations between the government of Hugo Chavez in Venezuela and the administration of George W. Bush in the USA, Venezuela has sought to expand its influence into Commonwealth Caribbean countries by offering a loan scheme for oil payments. Caricom countries account for almost half the votes in the Organization of American states and the Latin

Ronald Sanders



Some nematodes of freshwater fishes in Venezuela.  


The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults; Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyanema sp., Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb. n., P.(S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spirocamallanus) sp., Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimulticaecum sp., Contracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticaecum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom.nov. is proposed for T. caballeroi Díaz-Ungría, 1968 (a junior homonym of T. caballeroi Barus et Coy Otero, 1966). PMID:9188173

Moravec, F; Prouza, A; Royero, R



Occurrence of methylmercury in Lake Valencia, Venezuela  

SciTech Connect

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

Jaffe, R.; Cai, Y.; West-Thomas, J. [Florida International Univ., Miami, FL (United States)] [and others



Cetaceans of Venezuela: Their Distribution and Conservation Status.  

National Technical Information Service (NTIS)

Sighting, stranding, and capture records of whales and dolphins for Venezuela were assembled and analyzed to document the Venezuelan cetacean fauna and its distribution in the eastern Caribbean. An attempt was made to confirm species identification for ea...

A. Romero A. I. Agudo S. M. Green G. N. diSciara



El Fenomeno Chavez: Hugo Chavez of Venezuela, Modern Day Bolivar.  

National Technical Information Service (NTIS)

Hugo Chavez, the charismatic and controversial President of Venezuela, reached the ultimate seat of political power with his election as head of state in 1998. Carefully cultivating the image of an impoverished Venezuelan youth reaching the highest politi...

J. M. Post



Venezuela's Contribution to the Contemporary Law of the Sea.  

National Technical Information Service (NTIS)

Venezuela's contribution to the contemporary law of the sea is of special interest since that country will host the 1974 conference. The author reviews the development of the continental shelf doctrine and the concept of the patrimonial sea, with emphasis...

K. G. Nweihed



Hydrogen: BOC-FW venture secures major Venezuela project  

SciTech Connect

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.

Wood, A.



[Increasing difficulties for scientific publication in Venezuela].  


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

Ryder, Elena



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

Federal Register 2010, 2011, 2012, 2013

...Review)] Silicomanganese From India, Kazakhstan, Venezuela: Notice of Commission Determination...orders on silicomanganese from India, Kazakhstan, and Venezuela would be likely to on subject imports from India and Kazakhstan were inadequate. Notwithstanding...



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

ERIC Educational Resources Information Center

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

Sanchez-Vegas, Saadia



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

PubMed Central

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.

Linero-Arana, Ildefonso; Diaz Diaz, Oscarn



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


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

Liñero-Arana, Ildefonso; Díaz Díaz, Oscarn



U.S. Exports to Venezuela: A State-by-State Overview, 1987-1991.  

National Technical Information Service (NTIS)

Contents: Introductory Note; Statistical Regions Used in the Report; Top State Exporters to Venezuela; States with Greatest Dollar Growth in Exports to Venezuela, 1987-91; State and Regional Exports to Venezuela: 1987-91 (organized by region); State and R...



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

ERIC Educational Resources Information Center

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

Schwartzman, Karen



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

PubMed Central

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

Contreras-Ramos, Atilano; von der Dunk, Klaus



Complete genome sequences of two begomoviruses infecting weeds in Venezuela.  


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

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



Record of source-generated overpressures, Venezuela  

SciTech Connect

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.

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



Seismological Parameters in the Northern Andes, Venezuela  

NASA Astrophysics Data System (ADS)

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.

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



Genetic Characterization of Rabies Field Isolates from Venezuela  

Microsoft Academic Search

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.



Characterization of phosphorus in sinking particles in Cariaco Basin, Venezuela  

Microsoft Academic Search

Phosphorus (P) is an essential nutrient utilized by all organisms for biological productivity, yet little is known about its cycling within the marine realm. In this study, we used a five-step sequential sediment extraction method (SEDEX) to examine the composition of P in sinking particles obtained from one of the world's largest anoxic basins, Cariaco Basin, Venezuela. This method, which

M. L. Ranhofer; C. Benitez-Nelson; R. Thunell



Late Pleistocene carbonate dissolution in the Venezuela Basin, Caribbean Sea  

SciTech Connect

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

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



Temperature, heat, and mixing in Lake Valencia, Venezuela  

Microsoft Academic Search

Abstract Water temperature profiles, weather data, and lake level data spanning a 2-year period for Lake Valencia, Venezuela (10”N, 67”W), are used in an analysis of thermal regime, mixing, ancl heat flux, The lake, which has an arca of 350 km2 and mean depth of 19 m, is warm monomictic; it becomes isothermal annually near the end of November, at




Pedernales oilfield, eastern Venezuela: The first 100 years  

SciTech Connect

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

Gluyas, J.; Oliver, J.; Wilson, W. [BP Las Mercedes Caracas (Venezuela)



The Market for Building Products and Construction Equipment in Venezuela.  

National Technical Information Service (NTIS)

The market research was undertaken to study the present and potential US share of the market in Venezuela for building products and construction equipment; to examine growth trends in Venezuelan end-user industries over the next few years; to identify spe...



Venezuela Market Survey for Construction and Mining Machinery.  

National Technical Information Service (NTIS)

The market research was undertaken to study the present and potential US share of the market in Venezuela for construction and mining machinery; to examine growth trends in Venezuelan end-user industries over the next few years; to identify specific produ...



Market Study of Printing and Graphic Arts Equipment in Venezuela.  

National Technical Information Service (NTIS)

The market research was undertaken to study the present and potential US share of the market in Venezuela for printing and graphic arts equipment; to examine growth trends in Venezuelan end-user industries over the next few years; to identify specific pro...



Food Transfers Among Hiwi Foragers of Venezuela: Tests of Reciprocity  

Microsoft Academic Search

Although food sharing has been observed in many traditional societies, we still do not have a deep understanding of how various ecological conditions produce variation in who gives and who receives specific resources. To understand better the behavioral ecology of food sharing, we present data collected with the Hiwi of Venezuela and focus on two questions: (a) How do characteristics

Michael Gurven; Kim Hill; Hillard Kaplan; Ana Hurtado; Richard Lyles



[Epidemiology of ophidism in Venezuela (1996-2004)].  


The data of accidents caused by snakebites in Venezuela, registered at the morbidity statistics of the Direction of Epidemiology and Strategic Analysis of the Ministry of Health and Social Development were analyzed. During the years of 1996-2004, 53,792 snakebites were registered in Venezuela (5,976 cases average per year), with a higher incidence during the year 2004 (7,486 incidents). Zulia reported the highest frequency of all the states (5,975 cases); meanwhile the Midwestern region, constituted by Lara, Portuguesa, Falc6n and Yaracuy states, had a higher morbidity for snake bites. The highest incidence, distributed per states was registered in Cojedes, during the year 2001, with 228.72 cases per 100,000 inhabitants. When it was determined by regions, the highest incidence occurred during the year 2004 at los Llanos with 63.81 per 100,000 inhabitants. The median of the incidence rate for Venezuela during the period was of 21.46 accidents per 100,000 inhabitants. The classification of the endemic areas for ophidism, according to the percentiles 23, 50, 75 and 90, organized the country in: (a) states and regions of very high endemicity, (b) high endemicity, (c) middle, (d) low and (e) very low endemicity. These epidemiological data indicated that the accidents caused by snakes constitute a collective health problem in Venezuela. PMID:23947002

De Sousa, Leonardo; Bastouri-Carrasco, Jessica; Matos, Mercedes; Borges, Adolfo; Bónoli, Stefano; Vásquez-Suárez, Aleikar; Guerrero, Belsy; Rodríguez-Acosta, Alexis



Gross alpha radioactivity of drinking water in Venezuela  

Microsoft Academic Search

Bottled mineral water is consumed by a large population in Venezuela. The alpha emitters concentration was measured in samples of bottled water and water springs collected near the surface. Approximately 30% of the total mineral water suppliers was monitored. A database on natural and artificial radioactivity in drinking water was produced. Results indicate that 54% of the waters sampled contain

L. Sajo-Bohus; J. Gómez; T. Capote; E. D. Greaves; O. Herrera; V. Salazar; A. Smith



Venezuela, Survey of World Markets for Medical Equipment.  

National Technical Information Service (NTIS)

The market for medical equipment in Venezuela has been one of the most dynamic markets in the country over the past two to three years. Although drastic growth may not continue over the next few years, the market for this equipment will sustain excellent ...



Renal diseases in children in Venezuela, South America  

Microsoft Academic Search

The present study reports epidemiological data on renal disorders in children in Venezuela. Information was obtained from 14 centers for the period January through December 1998. A total of 3,624 patients were evaluated as either a first outpatient consultation or as a first hospital admission. Nearly 70% of the patients could be grouped in one of the following categories: (1)

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



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


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

Lessmann, Janeth; Arrivillaga, Jazzmín; Aguilera, Marisol



Primary amoebic meningoencephalitis: a new case from Venezuela.  


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

Caruzo, Giusseppe; Cardozo, José



Petroleum Resources of Venezuela and Trinidad and Tobago.  

National Technical Information Service (NTIS)

The status of known and ultimately recoverable crude oil and natural gas resources of the Federal Republics of Venezuela, and Trinidad and Tobago (hereafter referred to as Trinidad) is set forth in this report. The rates that oil resources may be availabl...



Evaluate past and ongoing enhanced oil-recovery projects in the United States and Venezuela, annex III. Venezuela-MEM\\/USA-DOE fossil-energy report III-1  

Microsoft Academic Search

The Agreement between the United States and Venezuela was designed to further energy research and development in six areas. This report focuses on Annex III - Evaluate Past and Ongoing Enhanced Oil Recovery Projects in the United States and Venezuela. Annex III has separated this portion of the coopertive energy research and development effort into four tasks for study. Energy

D. C. Ward; J. Garcia



A biostratigraphic sequence analysis in Cretaceous sediments from Eastern Venezuela  

SciTech Connect

This paper presents the results of a high resolution biostratigraphic study integrated with petrophysic analyses, of the Late Cretaceous sequence in several wells from the Maturin Sub-Basin, Eastern Venezuela. The main objective of this study is to integrate the different faunal and floral assemblages to the sedimentological evolution of the basin using sequential analysis techniques. This technique was applied using mainly terrestrial and marine palynomorphs which were relatively abundant and diverse as compared to the scarcity of foraminifera and nonnofossils. Based on the percentages of abundance and the diversity of the different groups of microfoss it was possible to establish the maximum flooding surfaces and condensation levels which allowed the definition of the possible candidates for the sequence boundaries. On the other hand, the identified bioevents made possible the definition of the chronostratigraphic datums of the sequence under study. The results obtained will contribute to optimize the exploration and development programs of the oil fields in Eastern Venezuela.

Paredes, I.; Carillo, M.; Fasola, A.; Luna, F. (Intevep S.A., Caracas (Venezuela))



Consideration of regulations of baby foods containing soybeans in Venezuela  

Microsoft Academic Search

Quality standards for industrially processed food products are being prepared by a joint committee composed of the private\\u000a sector, government and universities. These standards include specific dispositions which, if necessary, allow utilization\\u000a of different ingredients-soya protein derivatives among them- to improve the quality and quantity of the protein or to balance\\u000a the amino acid profile. Despite these efforts, in Venezuela,

J. F. Chavez



Update on Chagas disease in Venezuela: a review  

Microsoft Academic Search

The present article reviews the status of Chagas disease in Venezuela based on the detection of Trypanosoma cruzi infections both in referred patients with clinical presumptive diagnosis (1988-2002) and in individuals sampled from rural localities representative of the different geographical regions of the country (1995-2002). In the former group from 306 individuals examined, 174 (56.8%) were seropositive to T. cruzi;

Néstor Añez; Gladys Crisante; Agustina Rojas



Risk factors for dialysis-associated hepatitis C in Venezuela  

Microsoft Academic Search

Risk factors for dialysis-associated hepatitis C in Venezuela. Utilizing the first and second generation of enzyme immunoassays which detect antibodies to the C virus we investigated the frequency of anti-HCV antibodies in 315 patients undergoing hemodialysis. Other subpopulations at risk were used as reference groups. One hundred and twenty-three samples (39%) from the hemodialysis group repeatedly showed anti-HCV positive antibodies

Grete Y Muller; Mercedes E Zabaleta; Anabella Arminio; Carmen J Colmenares; Freya I Capriles; Nicolás E Bianco; Irma V Machado



Breeding systems in a montane tropical cloud forest in Venezuela  

Microsoft Academic Search

The breeding systems, reproductive efficacies and population densities of 75 species of trees, shrubs, perennial herbs and\\u000a vines in a montane tropical cloud forest in Venezuela are investigated. 56.96% and 44.32% of the trees, versus the other life\\u000a forms considered, respectively possess obligate outbreeding mechanisms. Two shrubs are non-pseudogamous apomicts. The percentage\\u000a of dioecy among tree species (31%) is among

Claudia Sobrevila; Mary T. Kalin Arroyo



Use of molluscicides in the control of bilharziasis in Venezuela*  

PubMed Central

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.

Jove, Jose Antonio



Curie point depth in Venezuela and the Eastern Caribbean  

NASA Astrophysics Data System (ADS)

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

Arnaiz-Rodríguez, Mariano S.; Orihuela, Nuris



Radon concentrations in hot spring waters in northern Venezuela  

Microsoft Academic Search

Concentrations of 222Rn were determined in selected thermal water samples of the northern region of Venezuela. Concentrations in the range of 1–560Bq\\/l were found. Soil radon concentrations and air radon concentrations related to the high values of radon concentration in water were investigated in El Castaño and at a spa in Las Trincheras. An outstandingly high radon efflux was found

Á. Horváth; L. O. Bohus; F. Urbani; G. Marx; A. Piróth; E. D. Greaves



Atmospheric mercury emissions from polluted gold mining areas (Venezuela)  

Microsoft Academic Search

Soil, waste rock and mud from mercury-gold amalgamation mining areas of El Callao (Venezuela) are highly enriched in Hg (0.5–500 µg g?1) relative to natural background concentrations (?1). Mercury fluxes to the atmosphere from twelve polluted sites of this area were measured in situ (6 a.m. to 8 p.m.) using\\u000a a Plexiglas flux chamber connected to a portable mercury analyzer (model RA-915+; Lumex, St.

A. García-Sánchez; F. Contreras; M. Adams; F. Santos



Venezuela recasts itself as a new frontier in the Americas  

SciTech Connect

In January of this year, Venezuela captured the attention of the international energy community by welcoming back the foreign oil companies that, 20 years earlier, it had shut out of the country by nationalizing the hydrocarbon sector. The tool used to attract that attention, a new exploration bidding round, is the most publicized event staged to date in the country`s aperture process. However, it is only the latest in a series of steps taken by officials to bring international oil and gas companies back to Caracas. Venezuela`s physical attraction is easily understood. The country possesses roughly one-half of Latin America`s (including Mexico) 125 billion bbl of established, conventional crude oil reserves, plus an estimated 300 billion bbl of additional, nonconventional reserves in the ultra-heavy crude belt of the Orinoco basin. Averaging 2.8 million bpd in 1996, Venezuelan crude production represents over 35% of regional oil output. Natural gas reserves total 138 Tcf, or just over one-half of the region`s total reserves of 274 Tcfg. Annual gas output averages just under 5 Tcf, of which roughly 30% is reinjected as part of tertiary oil recovery schemes. This paper reviews the incentives, deregulation, and government policies to restore the oil and gas industry to the country.

Reinsch, A.E. [Canadian Energy Research Inst., Calgary, Alberta (Canada)



Egalitarian policies and social determinants of health in Bolivarian Venezuela.  


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

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



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

USGS Publications Warehouse

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).

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



Regional structure and tectonic history of the obliquely colliding Columbus foreland basin, offshore Trinidad and Venezuela  

Microsoft Academic Search

Cenozoic eastward migration of the Caribbean plate relative to the South American plate is recorded by an 1100-km-long Venezuela-Trinidad foreland basin which is oldest in western Venezuela (65–55Ma), of intermediate age in eastern Venezuela (34–20Ma) and youngest beneath the shelf and slope area of eastern offshore Trinidad (submarine Columbus basin, 15.0Ma-Recent). In this study of the regional structure, fault families,

Emilio Garciacaro; Paul Mann; Alejandro Escalona



Radioactive source materials in Los Estados Unidos de Venezuela  

USGS Publications Warehouse

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.

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



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

Federal Register 2010, 2011, 2012, 2013

...INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1224-1225 (Preliminary...Venezuela; Institution of Antidumping Duty Investigations and Scheduling of Preliminary Phase Investigations. AGENCY: United States...



A new approach to the oil business in Venezuela  

SciTech Connect

Petroleos de Venezuela S.A. (PDVSA) has been meeting during the past two years with a considerable number of companies (groups) with a view to possible associations for the reactivation of known fields, joint activities in barely explored areas and the exploitation, refining, upgrading and marketing of crudes from the Orinoco Belt holder of immense reserves of extra-heavy crudes and bitumens. In Venezuela, a new approach to the oil business is under way. On January 1976, the law nationalizing the Venezuelan oil industry became effective establishing that the government retains the sole rights to the country's petroleum industry. However, Article 5 of the law made provision for associations in cases considered to be of [open quotes]National Interest.[close quotes] PDVSA became the wholly government-owned holding entity, encompassing 26 subsidiaries and affiliates. Other energy segments, particularly coal and petrochemicals, were not included in the law and since 1984 several associations with non-governmental entities have been established in Venezuela and very valuable experience has been garnered. Similarly, partnerships and acquisitions have been made in Europe and USA, mostly in refining, through PDVSA. The international petroleum industry foresees a modest, but steady increase in production during the coming decade, particularly in the second half of the nineties. This effect, added to the globalization concept, is making the traditional vertically integrated oil companies look for diverse [open quotes]lateral[close quotes] associations between groups, private and/or state owned with common interests, that will give greater security to sources of supply and market share.

Pradas, F.; Valdes, G. (Petroleos de Venezuela, Caracas (Venezuela))



Present Status of Historical Seismicity Studies in Colombia and Venezuela  

NASA Astrophysics Data System (ADS)

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: 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: 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.

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



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


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

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



Natural Host Relationships of Hantaviruses Native to Western Venezuela  

PubMed Central

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

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



Genetic variation of papaya ringspot virus in Venezuela.  


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

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



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

Microsoft Academic Search

This document presents the final report of a study of residential energy use in Caracas, the capital of Venezuela. It contains the findings of a household energy-use survey held in Caracas in 1988 and examines options for introducing energy conservation measures in the Venezuelan residential sector. Oil exports form the backbone of the Venezuelan economy. Improving energy efficiency in Venezuela

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




Microsoft Academic Search

Aloe (Aloe barbadensis L.) farmer characterization in Falcon State, Venezuela The aloe represents a crop from which annually primary goods are generated for a value of US $ 67 millions and final goods for more than US $105 thousand of millions. The attractiveness of this market contrasts with the marginal character that exhibits the exploitation in Falcon State, Venezuela, so

Henri Piña Zambrano; Rhode Azócar; Zunilde Lugo; Carlos Romero



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

Microsoft Academic Search

In the last few years the paleomagnetism research group, at the Universidad Simon Bolivar in Caracas (Venezuela), has undertaken combined studies of rock magnetism (e.g. natural magnetic remanence, magnetic susceptibility, hysteresis parameters etc.) and dielectric properties (maximum current depolarization temperatures and average activation energies) in Cretaceous and Paleogene sedimentary sequences from eastern and western Venezuela. Our main goal has been

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



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

Microsoft Academic Search

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




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

ERIC Educational Resources Information Center

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…

Psacharopoulos, George; Alam, Asad



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

ERIC Educational Resources Information Center

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…

Sunal, Cynthia Szymanski; Christensen, Lois


Wages and Foreign Ownership: A Comparative Study of Mexico, Venezuela and the United States  

Microsoft Academic Search

This paper explores the relationship between wages and foreign investment in Mexico, Venezuela, and the United States. Despite very different economic conditions and levels of development, we find one fact which is robust across all three countries: higher levels of foreign investment are associated with higher wages. In Mexico and Venezuela, foreign investment was associated with higher wages only for

Brian Aitken; Ann Harrison; Robert E. Lipsey



Fenología y ciclo de vida del alga Gracilariopsis tenuifrons (Gracilariaceae) en Sucre, Venezuela  

Microsoft Academic Search

Fenology and life cylce of Gracilariopsis tenuifrons (Gracilariaceae) at Sucre, Venezuela. The aim of this work was to determine the frequency of different reproductive phases and to induce the germination of spores from tetrasporic and cystocarpic Gracilariopsis tenuifrons from Chacopata and La Peña, Venezuela, under controlled laboratory conditions (temperature 22 ± 1ºC, 12L:12D photoperiod, salinity of 36 ± 1 PSU

Soraida Silva



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

SciTech Connect

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.

Not Available



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

ERIC Educational Resources Information Center

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…

Capriles, Oswaldo; And Others


The periodicity of Plasmodium vivax and Plasmodium falciparum in Venezuela.  


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

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



Raptor abundance and distribution in the Llanos wetlands of Venezuela  

USGS Publications Warehouse

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.

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



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


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

Reverón, Rafael Romero



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


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

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



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

SciTech Connect

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

Not Available



Swarms in Venezuela: characterization of the involved seismicity  

NASA Astrophysics Data System (ADS)

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

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



Postepizootic Persistence of Venezuelan Equine Encephalitis Virus, Venezuela  

PubMed Central

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.

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



Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela  

PubMed Central

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

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



Potential for Great Thrust Earthquakes in NE Colombia & NW Venezuela  

NASA Astrophysics Data System (ADS)

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.

Bilham, R. G.; Mencin, D.



Forecasting the Anomalous Discharge of the Caroní River, Venezuela.  

NASA Astrophysics Data System (ADS)

This study develops methods for the extended-range forecasting of the February-March minimum of water discharge of the Caroní River in eastern Venezuela, a watershed providing more than 70% of the hydroelectric power for the country. The predictors are the Tahiti minus Darwin pressure index and the Caroní discharge, both in the preceding July-August, and serve as input to stepwise multiple regression and neural networking. For regression the training period is 1950-79 and the verification period 1980-98. For neural networking the training period is 1950-75 plus 1976-85, and the verification period is 1986-98. The regression model captures more than a third of the variance of the February-March discharge and of the neural method more than half. The predictors are readily available, and application in real time is being initiated.

Hastenrath, Stefan; Greischar, Lawrence; Colón, Esperanza; Gil, Alfredo



Phytomass structure of natural plant communities on spodosols in southern Venezuela: the Bana woodland  

Microsoft Academic Search

Bana, or Low Amazon Caatinga is an evergreen sclerophyllous woodland. It occurs on bleached quartz sands in the lowlands of SW Venezuela, where it occupies relatively small ‘islands’ amidst Tall Amazon Caatinga which is exclusively developed on tropaquods.

F. Bongers; D. Engelen; H. Klinge



Doing Business in Venezuela: Country Commercial Guide for U.S. Companies.  

National Technical Information Service (NTIS)

The document serves as a guide to doing business in Venezuela. It contains key economic indicators for the country. In addition, it outlines trade regulations, the general tax system, market research, foreign investment, and tips for the business traveler...



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

ERIC Educational Resources Information Center

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)

Hanson, Mark



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

ERIC Educational Resources Information Center

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)

Schwartzman, Karen



Venezuela: Agricultural Situation. Official Control of Agriculture, 2008. GAIN Report Number VE8061.  

National Technical Information Service (NTIS)

Via new decrees announced by the President effective 1 August, Venezuelas agriculture and food sector, already heavily regulated, will be subject to further government control. Post reports on the most significant of the five new decrees affecting agricul...

C. Nunez



Faced with too many names, Venezuela makes a modest proposal  

NSDL National Science Digital Library

Inspirations: No more little sun kings names-are they 4real? baby names the Name and hidden meanings of Britain's brilliant place names from Ordnance Survey are a common feature of the human experience and have been with us for millennia. People have been named after products, geographic features, and just about everything else imaginable. The practice of naming children has been the subject of thousands of books, hundreds of weblogs, and informal conversations between soon-to-be mothers and fathers. This week, electoral officials in Venezuela introduced a bill that would effectively allow parents to select their baby's name from a list of a mere 100 approved by the central government. The stated purpose of the bill is "to preserve the equilibrium and integral development of the child." Interestingly enough, another intent of the bill is to prevent names that "generate doubts" about the gender of the child. Certain groups would receive exemptions, including Indians and foreigners, but there are still many who find this proposed measure quite offensive. One new mother in Venezuela remarked, "It's a question of taste", after she told a reporter that her daughter's name was Mariangela, which effectively combined Maria and Angela.The first link leads to a fine news article by Simon Romero on this proposal which appeared in this Wednesday's New York Times. The second link will take visitors to another piece on the subject offered by The Sydney Morning Herald. Moving on, the third link leads to an important piece from the Irish Independent which explores the influence of pop culture on baby names. The fourth link leads to the Social Security Administration's very fun and engaging site on popular baby names, past and present. The fifth link will take users to the "Behind the Name" site, which takes visitors through the etymology of thousands of names. The last link explores the world of British place names, courtesy of the Ordnance Survey. Important facts are revealed through this exploration of toponymy, including the history of Welsh place names such as Caerdydd, Tresaith, and Maesbanadlog.

Grinnell, Max



Mapa Geologico de Venezuela a Escala 1:750,000  

USGS Publications Warehouse

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.

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



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

SciTech Connect

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

Briceno, H.; Ostos, M.; Yoris, F. [Caracas (Venezuela)] [and others



Clockwise block rotations in the Perija Mountains, Venezuela  

SciTech Connect

Paleomagnetic analyses of Mesozoic sedimentary rocks (8 sites, 115 samples) from the Perija Mountains, Venezuela, yield well-grouped directions of both polarities. Fold tests imply that the magnetization of the Jurassic La Quinta Formation is pre-mid-Cretaceous in age and that the Lower Cretaceous Cogollo Group acquired its magnetization prior to its mid-Tertiary deformation. These data as well as the results from the Cretaceous Apon and La Luna Formations yield consistent northeast or southwest declinations and inclinations corresponding to the present latitude of the sampling area. The clockwise rotations indicated by these data are interpreted to be the result of rotation of fault-bounded blocks in a left-lateral strike-slip zone. Faults such as the Cogollo, La Ge, and Totumo faults which intersect the Perija-Tigre fault at low angles, had initially a north-northwest strike. The Late Oligocene northwest-southeast compression which initiated the uplift of the Perija Mountains rotated these faults to their present north-northeast orientation imparting the observed left-lateral slip. Our paleomagnetic data measure the corresponding rotation of the fault-bounded blocks. Model calculations suggest that a displacement on these faults of less than ten kilometers would be sufficient to cause the observed approximately 45[degrees] clockwise rotations.

Gose, W.A. (Univ. of Texas, Austin (United States)); Perarnau, A. (Intevep, Los Teques (Venezuela)); Castillo, J. (Universidad Simon Bolivar, Caracas (Venezuela))



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


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

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



Intestinal Parasitic Infections among Pregnant Women in Venezuela  

PubMed Central

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

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



Sedimentary sequence evolution in a Foredeep basin: Eastern Venezuela  

SciTech Connect

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

Bejarano, C.; Funes, D. [Corpoven S.A., Puerto La Cruz (Venezuela); Sarzalho, S.; Audemard, F.; Flores, G. [Caracas (Venezuela)



Diel variation of nitrogen fixation in Lake Valencia, Venezuela  

SciTech Connect

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.

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



Gran Sabana fires (SE Venezuela): a paleoecological perspective  

NASA Astrophysics Data System (ADS)

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

Montoya, Encarni; Rull, Valentí



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

SciTech Connect

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

Gonzales, G.; Mata, S.; Santiago, N. [Departamento de Geologia, Lagoven, S.A., Caracas (Venezuela)



[Lipid profile from low socioeconomic level preschool children. Valencia, Venezuela].  


Overweight and obesity are a public health problem worldwide affecting adults and children as well. The aim of this study was to assess overweight, lipid profile and cardiovascular risk ratios in 390 preschool children from low socio-economic level from Valencia, Venezuela. Nutritional anthropometric evaluation measured by body dimensions, and serum determination of cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol and cardiovascular risk factors, were determined. 95% of the children were in relative and critical poverty. 14.3% of undernutrition and 20.8% of overweight was found. Lipid profile was in normal range, with no significant differences by sex, but higher values for HDL-cholesterol and risk ratios were found in children aged 1 to 3.99 years. Even though no differences were found by nutritional status, overweight children had higher values for lipids, except HDL-cholesterol. 6.3% of overweight children had cholesterol > or =170 mg/dL, 16.5% LDL-cholesterol > or =110 mg/dL, 40.5% triglycerides > or =75mg/dL and 100% HDL-cholesterol <45 mg/dL. Overweight and lipid profile alterations were present in an important group of the children, which increase their risk of obesity and chronic non-transmissible diseases. Nutritional and educational intervention should be addressed. PMID:15916180

Solano, Liseti; Velásquez, Emma; Naddaf, Gloria; Páez, María



[Characterization of flaxseed (Linum usitatissimum L.) grown in Venezuela].  


In recent years, the consumption of flaxseed (Linum usitatissimum L.) has been promoted as a functional food for its health benefits, mainly attributable to its content of omega-3 fatty acids, lignans and dietary fiber. This study evaluated the microbiological quality, chemical composition and antioxidant properties of flaxseed grown in Venezuela and compared them to the values of a Canadian variety widely sold in the country. Total coliforms, molds and yeasts, S. aureus and sporulated of the genera Bacillus (aerobic) and Clostridium (anaerobic), moisture, fat, protein, total dietary fiber, soluble and insoluble, mucilage, minerals, fatty acid profile, equivalent HCN content, aw, color, polyphenols and antioxidant properties, like antiradical efficiency (AE), concentration of antioxidant needed to decrease the initial concentration by 50 %EC50) and the time required to reach the EC50 (TEC50) were evaluated. Significant differences in seed composition were determined, where its high content of fat, protein, alfa-linolenic acid and dietary fiber stand out. Differences were observed in the mucilage content, but not in soluble, insoluble and total fiber content. Equivalent HCN concentration in both seeds is in the order of 40 mg/100 g, which poses no health risks, considering their consumption patterns. Venezuelan flaxseed contains higher content of polyphenols than the Canadian does, but the antioxidant capacity of the latter is higher; both have an EA rated as average and a slow reaction time (TEC50 > 30 min). PMID:23610908

Cuevas, Zoitza Ostojich; Sangronis, Elba



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


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

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



STSHV a teleinformatic system for historic seismology in Venezuela  

NASA Astrophysics Data System (ADS)

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, ). 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.

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



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

NASA Astrophysics Data System (ADS)

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

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



Pyrethroid-impregnated curtains for Chagas' disease control in Venezuela.  


The use of insecticide treated materials for the control of Chagas' disease transmission is potentially a cost-effective and sustainable option where vectors are sylvatic. A study was undertaken in two rural Chagas' disease endemic communities (96 households) of Trujillo State, Venezuela. After a baseline study (including a short questionnaire survey, assessment of housing conditions, vector behaviour and preferences in vector protection), 37 households were chosen at random for protection by impregnated or non-impregnated curtains. During the 30-day entomological study vector collection of triatomine bugs were conducted in the early morning. The protective efficacy of curtains was determined by the number of vectors found dead or alive in control and experimental houses. It was found that house infestation of Chagas' disease vectors was high (60% of houses) in spite of good-quality houses due to a re-housing programme. The vectors were sylvatic (mainly Rhodnius robustus) and entered the houses at night. More than half the population (52%) preferred curtains to bednets for Chagas' disease protection. Users of pyrethroid-impregnated curtains were well protected as no living triatomines were found in bedrooms of houses with impregnated curtains compared to houses with non-impregnated curtains where an average of 4/7 vectors were found alive in bedrooms. In houses with impregnated curtains 21/30 triatomines died within 72 h; the triatomines which survived were found exclusively in rooms where no impregnated curtains had been placed. In houses with non-impregnated curtains 20% (6/30) of vectors died, probably due to rough handling. It is concluded that pyrethroid-impregnated curtains represent an important option for the reduction or even elimination of man-vector contact and thus of Chagas' disease transmission in areas where species of small triatomine bugs such as Rhodnius prolixus and R. robustus are the main vectors. PMID:12943974

Herber, Oliver; Kroeger, Axel



Atmospheric mercury emissions from polluted gold mining areas (Venezuela).  


Soil, waste rock and mud from mercury-gold amalgamation mining areas of El Callao (Venezuela) are highly enriched in Hg (0.5-500 microg g(-1)) relative to natural background concentrations (<0.1 microg g(-1)). Mercury fluxes to the atmosphere from twelve polluted sites of this area were measured in situ (6 a.m. to 8 p.m.) using a Plexiglas flux chamber connected to a portable mercury analyzer (model RA-915+; Lumex, St. Petersburg, Russia). Mercury fluxes ranged between 0.65 and 420.1 microg m(-2) h(-1), and the average flux range during the diurnal hours was 9.1-239.2 microg m(-2) h(-1). These flux values are five orders of magnitude higher than both reported world background Hg fluxes (1-69 ng m(-2) h(-1)) and the regional values, which are in the range 2-10 ng m(-2) h(-1). The flux results obtained in this study are, however, similar to those measured at Hg polluted sites such as chloro-alkali plants or polymetallic ore mining districts (>100,000 ng m(-2) h(-1)). The results from this study also show that Hg emissions from the soil are influenced by solar radiation, soil temperature and soil Hg concentration. Our data suggest that solar radiation may be the dominant factor affecting Hg degrees emission since the major species of mercury in polluted soil is Hg degrees (85-97% of total Hg). The simple release of Hg degrees vapor is probably the dominant process occurring with incident light in the field. The apparent activation energy for mercury emission indicates that the volatilization of mercury mainly occurred as a result of the vaporization of elemental mercury in soil. The degree of Hg emission differed significantly among the soil sites studied, which may be due to variations in soil texture, organic matter content and soil compaction. PMID:17120104

García-Sánchez, A; Contreras, F; Adams, M; Santos, F



Neogene history of the Carapita Formation, Eastern Venezuela basin  

NASA Astrophysics Data System (ADS)

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

Sanchez Zambrano, Dennis Alberto



Microsoft Academic Search

Effect of applications of organic residues on maize performance in two soils of Yaracuy State, Venezuela The intense land cultivation for maize cropping on the last 50 years in Yaracuy State, Venezuela, caused an accelerated soil degradation expressed by loss of soil organic matter and crop productivity. With the objective of improving those parameters, the use of organic residues were

Isabel Arrieche; Orlando Mora



Innovative security assessment during the facility design stage: protecting people, assets and the marine environment in the Gulf of Paria, Venezuela  

Microsoft Academic Search

This paper explains how ConocoPhillips Venezuela adapted existing methodology to respond Venezuelan and international security regulations by completing an innovative security vulnerability assessment (SVA) of planned offshore facilities and activities in the Gulf of Paria, northeastern Venezuela. Following the discovery of offshore oil resources in the Gulf of Paria, northeastern Venezuela in 1999, ConocoPhillips and its partners began planning operations

F. D. Rodriguez; J. Betancourt; W. Perry



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

PubMed Central

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

Brito, Miriam; Fernandez-Rodriguez, Thaly; Garrido, Mario Jose; Mejias, Alexander; Romano, Mirtha; Marys, Edgloris



Characterization of phosphorus in sinking particles in Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Phosphorus (P) is an essential nutrient utilized by all organisms for biological productivity, yet little is known about its cycling within the marine realm. In this study, we used a five-step sequential sediment extraction method (SEDEX) to examine the composition of P in sinking particles obtained from one of the world's largest anoxic basins, Cariaco Basin, Venezuela. This method, which is usually applied to sediments, chemically separates particulate P into 5 phases: loosely bound or exchangeable (PEx), iron-bound (PFe), authigenic (PAut), detrital (PDet), and organic (POrg). Samples were collected from November 2000 to April 2002 using four automated sediment traps moored at depths of 275, 455, 930 and 1250 m, with the 275 m trap located just above the oxic/anoxic interface. Our results indicate that the composition of particulate P changes dramatically as the material sinks through the water column. The 275 m trap was comprised of a mixture of PEx (57 %), POrg (23 %) and PFe (15 %), whereas the deepest trap was dominated by POrg (55 %) and PEx (26 %). Total P fluxes decreased by a factor of four between 275 and 1250 m (85.7 versus 18.5 \\mu mol m-2 d-1), with much of this decrease due to the > 75 % loss of PEx (49.2 to 4.9 \\mu mol m-2 d-1) and PFe (12.6 to 1.8 \\mu mol m-2 d-1). POrg decreased by only 50 % between these two depths (19.9 versus 10.2 \\mu mol m-2 d-1). Our results are consistent with the expectation that PEx is the most labile fraction of P and PFe is rapidly reduced in the anoxic bottom waters of Cariaco Basin. PEx correlates well with organic C (COrg) only in samples from the shallowest trap (r2 = 0.6), while in the deeper traps there is a strong correlation with terrigenous material (r2 = 0.6). This implies a change in the major source, and hence lability of this material as it sinks to the sea floor. POrg was very well correlated to COrg at all depths (r2 > 0.9), implying little to no preferential remineralization below 275 m. Additional strong relationships between Porg and opal and CaCO3 became apparent when upwelling versus non-upwelling time periods were separated, implying different mechanisms of Porg production throughout the year. Our results imply that water column P transformations are complex and need to be considered when studying the cycling of P in marine systems.

Ranhofer, M. L.; Benitez-Nelson, C.; Thunell, R.



Holocene evolution of the western Orinoco Delta, Venezuela  

USGS Publications Warehouse

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.

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



Seismic microzoning projects and their implementation in Venezuela  

NASA Astrophysics Data System (ADS)

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.

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



Exposición ocupacional a solventes orgánicos en una fábrica de calzado en Valencia, Venezuela, 2001  

Microsoft Academic Search

SUMMARY Potential health effects of organic solvents exposure were assessed. Thirty six workers of shoe manufacturer located in Valencia, Venezuela, were studied. They had a medical exam, and an occupational history. Biological indicators of exposure (toluene in blood; methylethy- ketone, methylisobuthylketone, acetone and hippuric acid in urine) and effect (creatinine in urine, hematologic analyses, bilirubin, transaminases and alkaline phoshatase-AP) were

Maritza Rodríguez; Guido Squillante; Maritza Rojas; TRABAJOS ORIGINALES


Bacteriosis en Cilantro (Coriandrum sativum L.) Causada por Xanthomonas campestris (Pammel) Dowson en Venezuela  

Microsoft Academic Search

In coriander (Coriandrum sativum) plants from commercial fields in the area of San Vicente, Aragua state, Venezuela, water-soaked, dark-brown angular spots were observed on leaf surface and distributed along the veins; as symptoms progressed, they caused leaf blight. Isolates obtained from diseased tissue on nutrient agar persistently produced light yellow colonies. Pathogenicity tests were performed by spray inoculation of a

Yolanda Guevara; Anna Maselli


Climatic risk for potato late blight in the Andes region of Venezuela  

Microsoft Academic Search

Potato is an important crop for Venezuelan agriculture. However, its production is highly affected by late blight (Phytophtora infestans), since weather is commonly favorable for this disease. The aim of this study was to determine the sowing dates of low climatic risk for potato late blight in the Andes region of Venezuela, with an agrometeorological disease model and geographical information

Beatriz Ibet Lozada Garcia; Paulo Cesar Sentelhas; Luciano Roberto Tapia; Gerd Sparovek



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

PubMed Central

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

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



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

ERIC Educational Resources Information Center

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

Ortega, Daniel E.



Analysis of avian communities in Lake Guri, Venezuela, using multiple assembly rule models  

Microsoft Academic Search

This study analyzed the distribution of resident, forest-interior bird species nesting on islands in Lake Guri, Venezuela using several different community assembly rule models. The models that were tested included Diamond's Assembly Rules, Size Structure, Guild Proportionality, Favored States, and Nestedness. It was determined that the species composition of the study communities was only weakly influenced by competition, but that

Kenneth Feeley




Microsoft Academic Search

A clinical, parasitologic, and serologic study carried out between 1988 and 1996 on 59 acute-phase patients in areas of western Venezuela where Chagas' disease is endemic showed 19 symptomatic patterns or groups of symptoms appearing in combination with different frequencies. The symptomatic pattern with the highest frequency was that showing simultaneously fever, myalgia, headache, and Romana's sign, which was detected



The nitrogen cycle in a ‘Terra Firme’ rainforest on oxisol in the Amazon territory of Venezuela  

Microsoft Academic Search

Standing stocks and fluxes of nitrogen, including nitrogen fixation and denitrification, were measured in a tropical rainforest on Oxisol in the Amazon Territory of Venezuela. The standing stock of nitrogen was comparable to that of temperate forests, but was higher than that in an adjacent forest on Spodosol. Fluxes were higher than in forests in the temperate zone, but lower

C. Jordan; W. Caskey; G. Escalante; R. Herrera; F. Montagnini; R. Todd; C. Uhl



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

Microsoft Academic Search

The author investigated the level, chemical fractions, and solubility of Pb in several roadside soils of heavily traveled areas of Caracas, Venezuela. Using 1 N HNOâ extraction, he studied the levels of lead in 25 roadside soil samples and found a very high level of Pb (average enrichment factor 21.0), indicating a strong lead pollution of Caracas roadside soils by




The Population Structure of Red Howler Monkeys (Alouatta seniculus) in Trinidad and Venezuela  

Microsoft Academic Search

The small troops and roughly even adult sexual ratio of Alouatta seniculus, studied in Bush Bush Forest in Trinidad and on the ranch Hato Masaguaral in the llanos of Venezuela, are more similar to A. caraya than to A. palliata. Other aspects of the troop composition are discussed. Though the red howler prefers certain types of habitat including tall trees,

M. K. Neville



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

ERIC Educational Resources Information Center

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)

Rojas, Alicia Mabel



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


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

Vásquez, Carlos; de Moraes, Gilberto J



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

ERIC Educational Resources Information Center

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

Chacon, C.T.



Distribution and mobility of mercury in soils of a gold mining region, Cuyuni river basin, Venezuela  

Microsoft Academic Search

An extensive and remote gold mining region located in the East of Venezuela has been studied with the aim of assessing the distribution and mobility of mercury in soil and the level of Hg pollution at artisanal gold mining sites. To do so, soils and pond sediments were sampled at sites not subject to anthropological influence, as well as in

F. Santos-Francés; A. García-Sánchez; P. Alonso-Rojo; F. Contreras; M. Adams



A new species of Pseudancistrus from the Río Caroní, Venezuela (Siluriformes: Loricariidae)  

Microsoft Academic Search

Pseudancistrus reus is a new species from the Río Caroní (Río Orinoco drainage) of Venezuela known from two individ- uals. It differs from all other Pseudancistrus by having a color pattern consisting of alternating dark and light bars. In addition, it differs from all except P. genisetiger and P. papariae by having an incomplete mid-dorsal plate row and from P.



Phytomass structure of natural plant communities on spodosols in southern Venezuela: The tall Amazon Caatinga forest  

Microsoft Academic Search

The phytomass structure of the evergreen lowland forest vegetation (Tall Amazon Caatinga) supported by tropaquods near San Carlos de Rio Negro, Federal Amazon Territory of Venezuela was studied in 13 10 m× 10 m plots. The plots were laid out subjectively to cover a low topographical gradient along which the forest on tropaquod is grading into a low woodland (Bana,

H. Klinge; R. Herrera



Prey composition in the carnivorous plants Utricularia inflata and U. gibba (Lentibulariaceae) from Paria Peninsula, Venezuela  

Microsoft Academic Search

Carnivorous aquatic plants, genus Utricularia (Lentibulariaceae), capture small aquatic organisms, such as rotifers, copepods, and cladocerans, by means of anatomical structures named bladders. The present study aimed to determine prey size and composition in U. gibba and U. inflata, which were collected from a small lake and an herbaceous wetland, respectively, located in Paria Peninsula (Sucre State, Venezuela). Water pH,

Elizabeth Gordon; Sergio Pacheco


Identification and Type Distribution of Astroviruses among Children with Gastroenteritis in Colombia and Venezuela  

PubMed Central

Astrovirus infections were detected by enzyme immunoassay in 12 (5%) of 251 stool samples from children with gastroenteritis from Bogota, Colombia. In addition, astroviruses were detected by reverse transcription-PCR in 3 (10%) of 29 stool samples negative for other enteric pathogens collected in Caracas, Venezuela, from children with gastroenteritis. Astrovirus type 1 was the most frequently detected virus.

Medina, Sandra M.; Gutierrez, Maria F.; Liprandi, Ferdinando; Ludert, Juan E.



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

ERIC Educational Resources Information Center

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

Ivancheva, Mariya



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


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

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



habitat de Nocardia asteroides, Phialophora pedrosoi y Cryptococcus neoformans en Venezuela  

Microsoft Academic Search

Resumen Se estudiaron 336 muestras de tierra, madera y plantas provenientes de diferentes zonas del Edo. Mérida\\/Venezuela y Estados vecinos. Fueron inoculados cobayos y hamsters intratesticularmente y ratones por via endovenosa. Testículos y pulmones respectivamente fueron examinados por medio de cultivos e histológicamente.

K. Salfelder; J. Schwarz; A. Romero; T. R. de Liscano; Z. P. Zambrano; I. P. Diaz




Microsoft Academic Search

Overweight and obesity are a public health problem worldwide affecting adults and children as well. The aim of this study was to assess overweight, lipid profile and cardiovascular risk ratios in 390 preschool children from low socio-economic level from Valencia, Venezuela. Nutritional anthropometric evaluation measured by body dimensions, and serum determination of cholesterol, triglycerides, HDL- cholesterol, LDL-cholesterol and cardiovascular risk

Liseti Solano; Emma Velásquez; Gloria Naddaf; María Páez


[Prevalence of human infections by Trypanosoma cruzi in blood banks in Venezuela].  


Primary investigations carried out in blood banks in Venezuela during the 1950s, indicated that overall seroprevalence for Trypanosoma cruzi infection was 12% amongst blood donors. In Venezuela, blood donation is free. All public and private blood banks are controlled by the Ministry of Health. As from 1988 the ELISA technique was uniformly used in blood banks for the detection of T. cruzi infections. Annual median seroprevalence, between 1988 to 1992, was 1.20% (1.09-1.94%), with geographical variations between localities in several States. States with higher prevalence rates are located in the western and central part of Venezuela: Portuguesa, Lara, Trujillo, Cojedes and Carabobo. Due to difficulties in obtaining incidence rates for Chagas disease, it seems proper to use prevalence rates due to its greater stability; and in the specific case of Venezuela, due to a lesser severity and a higher survival of this disease at present. Considering that there is little to be offered to the seropositive individual, repeatability is avowed for serological diagnosis. Specificity should be strived for in the light of lower prevalence rates at present. PMID:8115813

Aché, A




Microsoft Academic Search

PROAGRO is the leading firm in the broiler business in Venezuela. It is integrated through hatchery, grow-out, processing and distribution activities. As a consequence of strict price regulation policies enforced by the government in the poultry products, PROAGRO experienced serious injury to its profitability over the last few years. The most severe regulations were applied to PROAGRO's chief product (whole,

Jose E. Gomez




Microsoft Academic Search

SUMMARY This paper describes the activities carried out in the Enhanced Research Program on Billfish in Venezuela (PIIMV) for the period from January 2006 to July 2007. During the period indicated 16 trips were carried out in 2006 and four in 2007, monitored by PIIMV observers, which represented a coverage rate in 2006 of 7% for all the trips made

Luís A. Marcano; Freddy Arocha; José Alío; Jesús Marcano; A. Lárez; X. Gutiérrez; G. Vizcaino


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

Federal Register 2010, 2011, 2012, 2013 order to more accurately report the costs of production, as...132 F. Supp. 2d 1, 8 (CIT 2001) (citing Algoma Steel...accompanied by a market research report for 75 percent ferrosilicon...and III-4; Foreign Research Report; Supplement to Venezuela...



Factors Affecting Student Success at the National Open University of Venezuela.  

ERIC Educational Resources Information Center

Findings of this analysis of the effect of selected variables on attrition in the introductory course of the National Open University of Venezuela suggest that noninstitutional variables accounted for the largest proportion of variance of student completion. Counseling and course redesign are recommended to enhance student motivation to complete…

de Freitas, Katia Siqueira; Lynch, Patrick



A Gene Cluster for Macrolide Antibiotic Biosynthesis in Streptomyces venezuelae: Architecture of Metabolic Diversity  

Microsoft Academic Search

In a survey of microbial systems capable of generating unusual metabolite structural variability, Streptomyces venezuelae ATCC 15439 is notable in its ability to produce two distinct groups of macrolide antibiotics. Methymycin and neomethymycin are derived from the 12-membered ring macrolactone 10-deoxymethynolide, whereas narbomycin and pikromycin are derived from the 14-membered ring macrolactone, narbonolide. This report describes the cloning and characterization

Yongquan Xue; Lishan Zhao; Hung-Wen Liu; David H. Sherman



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

ERIC Educational Resources Information Center

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,…

Anderson, Teresa, Comp.; And Others


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

SciTech Connect

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

Daly, M. (BP Exploracion de Venezuela, Stockley Park, Middlesex (United Kingdom)); Audemard, F. (Intevep, Miranda (Venezuela)); Valdes, G. (Petroleos de Venezuela, Caracas (Venezuela))



Neotropical genera of Naucoridae (Hemiptera: Heteroptera: Nepomorpha): new species of Placomerus and Procryphocricos from Guyana and Venezuela.  


The Neotropical fauna of saucer bugs (Naucoridae) currently includes four monotypic genera. Recent extensive collecting in Venezuela has produced three new species in two of these genera. In addition, undetermined Guyanan specimens of one of the new species were found in the United States National Museum of Natural History. Thus, described here are Placomerus obscuratus n. sp. from Guyana and Venezuela with brachypterous and macropterous hindwing forms, and two species of Procryphocricos from Venezuela. Procryphocricos quiu n. sp. is described from the brachypterous forewing form and Procryphocricos macoita n. sp. from both brachypterous and macropterous forms. Previously described species also are discussed. PMID:24869509

Sites, Robert W; Camacho, Jesús



[Blastocystosis: a high prevalence of cases found in patients from Health Center of Soledad, Anzoategui State, Venezuela].  


The parasitological examination of fecal samples from 98 patients from an Ambulatory Health Center of Soledad, Anzoategui, Venezuela revealed a rather high proportion of results positive for Blastocystis hominis (46.9%). PMID:16082488

Velásquez, Virma; Caldera, Rixcia; Wong, Wladimir; Cermeño, Gloria; Fuentes, Maximo; Blanco, Ytalia; Aponte, Maria; Devera, Rodolfo



Location of the genes for anthranilate synthase in Streptomyces venezuelae ISP5230: genetic mapping after integration of the cloned genes.  


The anthranilate synthase (trpEG) genes in Streptomyces venezuelae ISP5230 were located by allowing a segregationally unstable plasmid carrying cloned S. venezuelae trpEG DNA and a thiostrepton resistance (tsr) marker to integrate into the chromosome. The integrated tsr was mapped by conjugation and transduction to a location close to tyr-2, between arg-6 and trpA13. A genomic DNA fragment containing trpC from S. venezuelae ISP5230 was cloned by complementation of a trpC mutation in Streptomyces lividans. Evidence from restriction enzyme analysis of the cloned DNA fragments, from Southern hybridization using the cloned trp DNA as probes, and from cotransduction frequencies, placed trpEG at a distance of 12-45 kb from the trpCBA cluster. The overall arrangement of tryptophan biosynthesis genes in the S. venezuelae chromosome differs from that in other bacteria examined so far. PMID:8515229

Paradkar, A S; Stuttard, C; Vining, L C



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

ERIC Educational Resources Information Center

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)

Lynch, Patrick D.



Interpretacion: The Lived Experience of Interpretation in the Bilingual Psychotherapist  

ERIC Educational Resources Information Center

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…

Melchor, Rosemary Laura



Cloning and functional analysis of a phosphopantetheinyl transferase superfamily gene associated with jadomycin biosynthesis in Streptomyces venezuelae ISP5230  

Microsoft Academic Search

Sequence analysis of a XhoI\\/SacI fragment of chromosomal DNA downstream of jadL in the Streptomyces venezuelae ISP5230 gene cluster for jadomycin biosynthesis detected a partial ORF similar in its deduced amino acid sequence to the hetI product involved in synthesizing a regulator of heterocyst spacing in Anabaena. By probing a phage library of S. venezuelae DNA with the XhoI\\/SacI fragment,

Liru Wang; Jennifer McVeyã; Leo C. Vining


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

SciTech Connect

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

Figueroa, M.J.; Sathaye, J.



Molecular characterization of a new begomovirus that infects Euphorbia heterophylla and Solanum lycopersicum in Venezuela.  


We report the complete nucleotide sequence of a begomovirus isolate infecting Euphorbia heterophylla and tomato (Solanum lycopersicum) in central Venezuela. Based on the current taxonomic criteria for the genus Begomovirus, the isolate was shown to represent a novel species, tentatively named Euphorbia mosaic Venezuela virus (EuMVV). Its DNA-A is most closely related to those of Euphorbia-infecting begomoviruses from the Caribbean and Central America. The DNA B component forms a phylogenetic cluster with Euphorbia and Sida-infecting begomoviruses from the squash leaf curl virus (SLCV) cluster. EuMVV is transmissible to S. lycopersicum and Capsicum annuum by biolistics of infectious cloned DNA-A and DNA-B components and induces characteristic leaf downward curling and yellowing in S. lycopersicum and and yellowing and leaf distortion in Capsicum annuum. PMID:22052541

Zambrano, Karla; Fernández-Rodríguez, Thaly; Marys, Edgloris



Zornia decussata (Leguminosae: Papilionoideae: Dalbergieae), a new species from the Amazon region of Venezuela  

Microsoft Academic Search

Summary  \\u000a Zornia decussata, a new species from Venezuela, is described and illustrated. It belongs to sect. Anisophylla of subgen. Zornia and occurs in the Federal Territory of Amazonas, in the region of Rincones de Chacorro. The species is characterised mainly\\u000a by its decussate bracteoles which lack an auricle, by the presence of a cataphyll between the stipules and by the

Ana Paula Fortuna-Perez; Gwilym P. Lewis; Ana Maria Goulart de Azevedo Tozzi



Plant collecting along the lower Orinoco, Venezuela: H. H. Rusby and R. W. Squires (1896)  

Microsoft Academic Search

The plant collecting trip by H. H. Rusby and R. W. Squires in early 1896 to the lower Río Orinoco, Venezuela, was sponsored\\u000a by The Orinoco Company Limited, which was promoted by many residents of Faribault, Rice Co., Minnesota, U.S.A. In February\\u000a 1896, the company formed an exploring party in order to map a large concession of approximately 10,000,000 acres

Laurence J. Dorr



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

Microsoft Academic Search

We present new measurements of splitting of core shear-wave phases (SKS, SKKS, PKS) recorded at seven stations in the eastern Caribbean region. Six stations in northeastern Venezuela and Trinidad constituted the SECaSA92 temporary broadband array. The seventh station, SJG, is installed on Puerto Rico. We also attempted to measure source-side splitting of S waves from earthquakes in the Lesser Antilles

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



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

SciTech Connect

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.

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



Determination of genotypes of hepatitis C virus in Venezuela by restriction fragment length polymorphism.  

PubMed Central

Hepatitis C virus genotypes in Venezuela were analyzed by restriction fragment length polymorphism in the 5' noncoding region. The absence of BstUI digestion was found to be a useful marker for genotype 2 specimens. From 122 serum samples, 66, 20, and 2.5% were classified as genotypes 1, 2, and 3, respectively; 0.8% were classified as genotype 4; and 10% appeared to be mixed infections.

Pujol, F H; Loureiro, C L; Devesa, M; Blitz, L; Parra, K; Beker, S; Liprandi, F



Unexpected reproductive strategy of Sardinella aurita off the coast of Venezuela  

Microsoft Academic Search

Biological sampling of Spanish sardine (Sardinella aurita Valenciennes, 1847) off the coast of Venezuela from 1956 to 1989 was used to study the reproductive strategy and migration\\u000a pattern of the population. Whereas in many pelagic fishes the energy re-allocation necessary for reproduction usually occurs\\u000a optimally at the end of the upwelling season when planktonic production reaches a maximum, in the

P. Fréon; M. El Khattabi; J. Mendoza; R. Guzmán



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

NASA Astrophysics Data System (ADS)

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.

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



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

ERIC Educational Resources Information Center

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

Warring, Douglas F.; Huber-Warring, Tonya



Evaluation of the Effects of Soil Depth on Microbial Activity in Three Agroecosystems in Venezuela  

Microsoft Academic Search

The objective of this study was to determine the total organic carbon (TOC), basal respiration (BR), microbial biomass carbon (MBC), the metabolic quotient (qCO2), and ratio of microbial biomass carbon to total organic carbon (MBC\\/TOC) at different soil depths in three agroecosystems in Fundo Zamorano Independencia, Cojedes State, Venezuela. The types of agroecosystems studied were short-cycle corn and bean cropland,

N. Cañizales-Paredes; A. Tolón-Becerra; X. B. Lastra-Bravo; F. M. Ruiz-Dager



Chloramphenicol resistance in Streptomyces: cloning and characterization of a chloramphenicol hydrolase gene from Streptomyces venezuelae.  


A 6.5 kb DNA fragment containing a chloramphenicol-resistance gene of Streptomyces venezuelae ISP5230 was cloned in Streptomyces lividans M252 using the high-copy-number plasmid vector pIJ702. The gene was located within a 2.4 kb KpnI-SstI fragment of the cloned DNA and encoded an enzyme (chloramphenicol hydrolase) that catalysed removal of the dichloroacetyl moiety from the antibiotic. The deacylated product, p-nitrophenylserinol, was metabolized to p-nitrobenzyl alcohol and other compounds by enzymes present in S. lividans M252. Examination of the genomic DNA from several sources using the cloned 6.5 kb SstI fragment from S. venezuelae ISP5230 as a probe showed a hybridizing region in the DNA from S. venezuelae 13s but none in the DNA from another chloramphenicol producer, Streptomyces phaeochromogenes NRRLB 3559. The resistance phenotype was not expressed when the 6.5 kb SstI fragment or a subfragment was subcloned behind the lac-promoter of plasmid pTZ18R in Escherichia coli. PMID:2324705

Mosher, R H; Ranade, N P; Schrempf, H; Vining, L C



Venezuela near doubles proven reserves. 2. US protectionism and the geopolitics of petro-geology  

SciTech Connect

This issue honors the late Dan Lundberg, founder and former publisher of Energy Detente (ED). Mr. Lundberg founded ED a few months after his first visit to Venezuela in December 1979 and attending his first OPEC meeting. His acute awareness of factors affecting crises in oil markets was combined permanently in the publication founded in 1980, and it was designed from the very first to illuminate Western hemisphere and especially still-undeveloped hydrocarbon resources. Two unrelated events are treated as very much related in this issue: (A) The USA National Petroleum Council released Factors Affecting US Oil and Gas Outlook. (B) Almost simultaneously Petroleos de Venezuela, the national oil company of Venezuela released its new proven oil figures, close to 90% higher, at 55.5 billion barrels. The possible importance to US foreign policy is discussed. This issue of ED also contains: (1) ED refining netback data for the US Gulf and West Coasts, Rotterdam, and Singapore for mid March 1987; and (2) the ED fuel price/tax series March 1987 edition for countries of the Western Hemisphere. 8 figures, 6 tables.

Not Available



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


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

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



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


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

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



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

NASA Astrophysics Data System (ADS)

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

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



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


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

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



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

PubMed Central

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



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

NASA Astrophysics Data System (ADS)

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.

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



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

SciTech Connect

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

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



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

NASA Astrophysics Data System (ADS)

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

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



Pneumococcal carriage among indigenous Warao children in Venezuela: serotypes, susceptibility patterns, and molecular epidemiology.  


Little attention has been paid to pneumococcal carriage and disease in Amerindians from Latin America. The Warao people, an indigenous population from Venezuela, live in the delta of the Orinoco River in geographically isolated communities with difficult access to medical care. To obtain insight into pneumococcal carriage and the theoretical coverage of pneumococcal vaccines in this population, we investigated pneumococcal colonization, serotype, and genotype distribution among Warao children in 9 distinct, geographically isolated communities in the Delta Amacuro area in the northeast of Venezuela. From April 2004 through January 2005, a total of 161 Streptococcus pneumoniae isolates were recovered from single nasopharyngeal swab samples obtained from 356 children aged 0-72 months. The overall pneumococcal carriage rate was 49%, ranging from 13% to 76%, depending on the community investigated and the age of the children (50% among children aged <2 years and 25% among children aged >2 years). The most frequent serotypes were 23F (19.5% of isolates), 6A (19.5%), 15B (10.4%), 6B (9.1%), and 19F (7.2%). The theoretical coverage of the 7-valent pneumococcal conjugate vaccine, including the cross-reactive nonvaccine serotype 6A, was 65%. A total of 26% of the isolates were resistant to first-line antibiotics, with 70% of these strains being covered by the 7-valent pneumococcal conjugate vaccine. Restriction fragment end labelling analysis revealed 65 different genotypes, with 125 (80%) of the isolates belonging to 27 different genetic clusters, suggesting a high degree of horizontal spread of pneumococcal strains in and between the villages. The high colonization rates and high (registered) acute respiratory tract infection morbidity and mortality in this part of Venezuela suggest that Warao children are at increased risk for pneumococcal disease and, therefore, benefit from vaccination. PMID:17990224

Rivera-Olivero, Ismar A; Bogaert, Debby; Bello, Teresita; del Nogal, Berenice; Sluijter, Marcel; Hermans, Peter W M; de Waard, Jacobus H



A new strain, Streptomyces venezuelae GY1, producing a poly(vinyl alcohol)-degrading enzyme  

Microsoft Academic Search

Summary  An actinomycete strain, which could produce an extracellular poly(vinyl alcohol) (PVA)-degrading enzyme, was isolated from\\u000a a PVA-contaminated soil sample using PVA as the sole carbon source. The strain was identified as Streptomyces venezuelae according to the whole-nucleotide-sequence analysis of 16S rDNA, the morphological and the physiological characteristics.\\u000a The strain produced 120 U\\/l extracellular PVA-degrading enzyme when PVA was used as the

Ying Zhang; Yin Li; Wei Shen; Dengru Liu; Jian Chen



Lepidopterism due to exposure to the moth Hylesia metabus in northeastern Venezuela.  


Lepidopterism refers to a spectrum of medical conditions in humans that usually involves the skin and results from contact with the adult or larval forms of certain butterflies and moths. We analyzed the epidemiologic and clinical features associated with exposure to the moth Hylesia metabus between 1970 and 2002 in the Cajigal district, Sucre, Venezuela. Fifty cases of lepidopterism mostly affecting individuals under 18 years of age were identified during this period and manifested as pruritic dermatitis with or without associated respiratory symptoms. With increased travel to endemic areas of lepidopterism, travel and tropical medicine practitioners should be aware of the clinical spectrum of this condition. PMID:16282317

Rodriguez-Morales, Alfonso J; Arria, Melissa; Rojas-Mirabal, Jose; Borges, Eduardo; Benitez, Jesus A; Herrera, Melfran; Villalobos, Carlos; Maldonado, Andrea; Rubio, Nestor; Franco-Paredes, Carlos



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

PubMed Central

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.

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.



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

PubMed Central

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.



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

USGS Publications Warehouse

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.

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



Mercury Levels in Mole Crabs Hippa cubensis, Emerita brasiliensis, E. portoricensis, and Lepidopa richmondi (Crustacea: Decapoda: Hippidae) from a Sandy Beach at Venezuela  

Microsoft Academic Search

Mercury pollution in Venezuela’s coastal area has been demonstrated for several years, especially at the Golfo Triste region (10° N, 68° W), which was subjected for several years to the discharges of mercury from a chlorine-alkal i plant that used an electrolytic process involving mercury electrodes. From 1987 to 1989 a base line study along the entire coast of Golfo

D. Pérez




Microsoft Academic Search

Effect of NPK fertilization on yield of a commercial cocoa plantation at the Southeast of Táchira State, Venezuela The low cocoa yields in Venezuela are associated with lack of fertilization. Two experiments were performed in a commercial plantation in the Southeast of Táchira State to determine the plant response to several doses of fertilization. The treatments were established based on

Dercy Parra; Erbert Gamboa; José Rincón



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

SciTech Connect

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.

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



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

SciTech Connect

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

Stronach, N.J.; Kerr, H.M.; Scotchmer, J. [Robertson Research International Ltd., Llandudno, Gwynedd (United Kingdom); Hunter, V. [Consultores Geostrat CA, Puerto La Cruz (Venezuela)



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

USGS Publications Warehouse

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

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



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

ERIC Educational Resources Information Center

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

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


Molecular epidemiology of dengue type 2 virus in Venezuela: evidence for in situ virus evolution and recombination  

Microsoft Academic Search

Epidemic outbreaks of dengue fever (DF) were first recorded in Venezuela in 1978 and were followed by the emergence of dengue haemorrhagic fever (DHF) outbreaks in 1989. To gain a better understanding of the nature of these epidemics, the complete envelope (E) gene sequence of 34 Venezuelan dengue type 2 (DEN-2) viruses, isolated between 1997 and 2000 was determined. Of

N. Y. Uzcategui; D. Camacho; G. Comach; R. Cuello de Uzcategui; E. C. Holmes; E. A. Gould



Identification of factors affecting growth and survival of the tropical scallop Euvola (Pecten) ziczac in the Golfo de Cariaco, Venezuela  

Microsoft Academic Search

We examined the effect of environmental variables on the growth and survival of the tropical scallop, Euvola ziczac (L.), in suspended culture at Turpialito in the Golfo de Cariaco, northeastern Venezuela. Four growth trials were run, three using 10-mm spat produced from hatchery spawnings in August 1992, which were grown at 8, 21 and 34 m in depth, and a

César J. M Lodeiros; John H Himmelman




Microsoft Academic Search

The artisanal fishery at Playa Verde, located in the central coast of Venezuela, is base port of the largest fishery targeting billfish in the country. Historical data on billfish landings are used to describe the trends in abundance of sailfish, Istiophorus albicans, blue marlin, Makaira nigricans, and white marlin, Tetrapturus albidus, in the southern Caribbean Sea. Fishermen in Playa Verde

L. A. Marcano; J. J. Alió; F. Arocha; X. Gutiérrez


Morphological and taxonomic studies on some little-known species of Gracilaria (Gracilariales: Rhodophyta) from Venezuela. 1. G. damaecornis  

Microsoft Academic Search

The morphology, anatomy and reproduction (tetrasporic, male and female) of a poorly known species of Gracilaria i.e. G. damaecornis J. Agardh was studied, using material collected in eastern Venezuela. Spermatangia are produced in well-defined and deeply immersed multicavitied conceptacles (‘m’ type). Nutritive filaments are present both at the floor and top (outer pericarp) of the cystocarp. The lectotype of G.

E. K. Ganesan




Microsoft Academic Search

For crude oils (from the South-Central part of the Eastern Venezuela Basin, EVB) three oil seeps (two of them located in The Paría Península region, and the other one towards the north-western side of the Orinoco river) and three reservoir rocks with oil impregnations (Junin Field, Orinoco Heavy Oil Belt) from the EVB, were analysed in this study in order

Carolina C. OLIVARES


An extraordinary example of photokarren in a sandstone cave, Cueva Charles Brewer, Chimantá Plateau, Venezuela: Biogeomorphology on a small scale  

Microsoft Academic Search

A distinctive suite of small-scale erosional forms that are oriented towards the light occur close to the entrance of Cueva Charles Brewer, a large cave in a sandstone tepui, in SE Venezuela. These are the third example of photokarren ever studied in the world, the other two being from Borneo and Ireland. They are the only photokarren ever described from

J. Lundberg; D. A. McFarlane; C. Brewer-Carias



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


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

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




PubMed Central

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

Martinez, Dianny; Rodulfo, Hectorina E.; Rodriguez, Lucy; Cana, Luisa E.; Medina, Belkis; Guzman, Militza; Carreno, Numirin; Marcano, Daniel; Donato, Marcos De



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


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

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



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

SciTech Connect

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

Pinto, N.; Mengual, R.; Anz, J.; Rodney, C. [Lagoven, S.A., Maturin (Venezuela)



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

SciTech Connect

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

Sebastiani, M.; Llambi, L.D.; Marquez, E. [Univ. Simon Bolivar (Venezuela)] [and others] [Univ. Simon Bolivar (Venezuela); and others



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

SciTech Connect

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

Regueiro, J. [Univ. Simon Bolivar, Sartenejas (Venezuela)] [Univ. Simon Bolivar, Sartenejas (Venezuela); Pena, A. [Lagoven S.A., Caracas (Venezuela)] [Lagoven S.A., Caracas (Venezuela)



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

SciTech Connect

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

Fonseca, A.; Navarro, A. [Maraven, S.A., Caracas (Venezuela); Osorio, R.; Corvo, F.; Arismendi, J. [Instituto de Ingenieria, Caracas (Venezuela)



A plasmid involved in chloramphenicol production in Streptomyces venezuelae: evidence from genetic mapping.  


To test the hypothesis that chloramphenicol production in Streptomyces venezuelae depends on the presence of a plasmid, mapping analysis was carried out by using eight markers in addition to chloramphenicol production and melanoid pigment formation. The sequence of the eight markers was determined on a circular linkage map as follows: -his-ade-str-leu-lys-met-ilv-pro-(his-). This sequence resulted in the frequency of quadruple crossover (q.c.o.) recombinants having the lowest value, 3-2 to 4-9%. However, the character of chloramphenicol non-production, which was obtained by incubating mycelia with acriflavin, was not required to explain the results. From these results and other tests, it is concluded that chloramphenicol production is controlled by a plasmid. This plasmid appeared to be non-transferable in conjugation. PMID:1194895

Akagawa, H; Okanishi, M; Umezawa, H



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


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

Liñero Arana, Ildefonso; Díaz Díaz, Oscar



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

NASA Astrophysics Data System (ADS)

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.

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



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

PubMed Central

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.

Maier, Crystal A.



[Prevalence of Encephalitozoon intestinalis and Enterocytozoon bieneusi in HIV positive patients to Maracaibo, Venezuela].  


Microsporidioses are considered emerging and opportunistic infections in immunocompromised individuals worldwide. The purpose of this study was to identify the species of intestinal microsporidia in patients with HIV-AIDS from the Servicio Autónomo Hospital Universitario de Maracaibo, Venezuela (SAHUM). Fecal samples were collected from 50 patients with confirmed diagnosis of HIV, during the years 2007 and 2008; the CD4 values were obtained from 42 patients. The samples were analyzed by separate PCRs to identify Encephalitozoon intestinalis and Enterocytozoon bieneusi. Microsporidia species showed a 36% prevalence: ten patients had Encephalitozoon intestinalis, four Enterocytozoon bieneusi and four both species. An inverse and statistically significant relationship between the CD4 count and the presence of microsporidia in the fecal sample was also found. It is remarkable the high prevalence of microsporidia species observed in the HIV patients studied, with a predominance of E. intestinalis. PMID:23781713

Rivero-Rodríguez, Zulbey; Hernández Sierra, Amparo; Arráiz, Nailet; Bracho Mora, Angela; Villalobos Perozo, Rafael



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

PubMed Central

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

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



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

PubMed Central

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

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



Placental transfer of lead in mother/newborn pairs of Maracaibo City (Venezuela).  


The placental transfer of lead (Pb) from mother to newborn in seventeen pregnant women receiving medical care at Adolfo Pons Hospital, Maracaibo (Venezuela), is presented. Maternal blood was collected by venipuncture during the first stage of labor, while neonatal blood was taken from the umbilical cord vein; placental blood samples were obtained at the time of delivery. Lead determination was carried out by graphite furnace atomic absorption spectrometry. Blood Pb levels (mean +/- SD, microgram/L) of 53.2 +/- 31.8, 46.3 +/- 24.5 and 66.3 +/- 33.3 were found for newborns, placentas and mothers, respectively. Significant blood Pb correlations were observed. Results indicated that even when the mother had a low blood lead level the placenta did not have a restrictive barrier-type effect to protect against Pb transfer from mother to newborn. Neonates' blood Pb concentrations were much lower than the accepted upper limit of 250 micrograms/L Pb. PMID:2136289

Romero, R A; Granadillo, V A; Navarro, J A; Rodríguez-Iturbe, B; Pappaterra, J; Pirela, H



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


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

Nava, A; Londoño, A; Polston, J E



Genotyping of human rotaviruses circulating among children with diarrhea in Valencia, Venezuela.  


Rotavirus infection is the most common cause of severe gastroenteritis during childhood worldwide, especially in developing countries. Two rotavirus vaccines are available for childhood immunization programs. Evaluation of the vaccine performance will benefit from knowledge of the epidemiological features of rotavirus infection in regional settings. Limited information on the molecular characteristics of the rotavirus types circulating in Venezuela is available. Eighty seven (89.7%) of the 97 ELISA rotavirus positive stool samples collected from children with diarrhea aged <5 years during 2003 in Valencia (Carabobo State), were G-, P- and NSP4-genotyped by RT-PCR and/or automated sequencing. Four common combinations, G3P[8]/NSP4-E1, G2P[4]/NSP4-E2, G9P[8]/NSP4-E1, and G1P[8]/NSP4-E1 were responsible for 50.6%, 35.6%, 5.7%, and 1.1%, respectively of cases of rotavirus diarrhea, most of them (66%) in children ?12 months. One uncommon G8P[14]/NSP4-E2 strain was also detected. Temporal fluctuation of genotype distribution occurred, but no differences by age, diarrhea severity score, sex, treatment type or patient medical attention were observed, except for the G3P[8]/NSP4-E1, associated with a more severe dehydration than any other type (P?Venezuela prior to vaccine implementation, showing the predominance of G3, significant proportion of G2 and moderate circulation of G9 strains. Epidemiological surveillance is needed to detect the emergence of new genotypes that could escape protection induced by vaccination. PMID:22012733

Vizzi, Esmeralda; Piñeros, Oscar; González, Germán Gabriel; Zambrano, José L; Ludert, Juan E; Liprandi, Ferdinando



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

USGS Publications Warehouse

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.

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



Common Distribution Patterns of Marsupials Related to Physiographical Diversity in Venezuela  

PubMed Central

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

Ventura, Jacint; Bagaria, Guillem; Sans-Fuentes, Maria Assumpcio; Perez-Hernandez, Roger



BRCA1 and BRCA2 mutations in breast cancer patients from Venezuela.  


A sample of 58 familial breast cancer patients from Venezuela were screened for germline mutations in the coding sequences and exon-intron boundaries of BRCA1 (MIM no. 113705) and BRCA2 (MIM no. 600185) genes by using conformation-sensitive gel electrophoresis. Ashkenazi Jewish founder mutations were not found in any of the samples. We identified 6 (10.3%) and 4 (6.9%) patients carrying germline mutations in BRCA1 and BRCA2, respectively. Four pathogenic mutations were found in BRCA1, one is a novel mutation (c.951_952insA), while the other three had been previously reported (c.1129_1135insA, c.4603G>T and IVS20+1G>A). We also found 4 pathogenic mutations in BRCA2, two novel mutations (c.2732_2733insA and c.3870_3873delG) and two that have been already reported (c.3036_3039delACAA and c.6024_6025_delTA). In addition, 17 variants of unknown significance (6 BRCA1 variants and 11 BRCA2 variants), 5 BRCA2 variants with no clinical importance and 22 polymorphisms (12 in BRCA1 and 10 in BRCA2) were also identified. This is the first genetic study on BRCA gene mutations conducted in breast cancer patients from Venezuela. The ethnicity of our population, as well as the heterogeneous and broad spectrum of BRCA genes mutations, must be considered to optimize genetic counseling and disease prevention in affected families. PMID:23096355

Lara, Karlena; Consigliere, Nigmet; Pérez, Jorge; Porco, Antonietta



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


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

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



The structure of DesR from Streptomyces venezuelae, a ?-glucosidase involved in macrolide activation  

PubMed Central

Antibiotics have, indeed, altered the course of human history as is evidenced by the increase in human life expectancy since the 1940s. Many of these natural compounds are produced by bacteria that, by necessity, must have efficient self-resistance mechanisms. The methymycin/pikromycin producing species Streptomyces venezuelae, for example, utilizes ?-glucosylation of its macrolide products to neutralize their effects within the confines of the cell. Once released into the environment, these compounds are activated by the removal of the glucose moiety. In S. venezuelae, the enzyme responsible for removal of the sugar from the parent compound is encoded by the desR gene and referred to as DesR. It is a secreted enzyme containing 828 amino acid residues, and it is known to be a retaining glycosidase. Here, we describe the structure of the DesR/d-glucose complex determined to 1.4-Å resolution. The overall architecture of the enzyme can be envisioned in terms of three regions: a catalytic core and two auxiliary domains. The catalytic core harbors the binding platform for the glucose ligand. The first auxiliary domain adopts a “PA14 fold,” whereas the second auxiliary domain contains an immunoglobulin-like fold. Asp 273 and Glu 578 are in the proper orientation to function as the catalytic base and proton donor, respectively, required for catalysis. The overall fold of the core region places DesR into the GH3 glycoside hydrolase family of enzymes. Comparison of the DesR structure with the ?-glucosidase from Kluyveromyces marxianus shows that their PA14 domains assume remarkably different orientations.

Zmudka, Matthew W; Thoden, James B; Holden, Hazel M



Biosynthesis of sulfur-containing amino acids in Streptomyces venezuelae ISP5230: roles for cystathionine beta-synthase and transsulfuration.  


A 0.5 kb fragment of Streptomyces venezuelae ISP5230 genomic DNA was amplified by PCR using primers based on consensus sequences of cysteine synthase isozyme A from bacteria. The deduced amino acid sequence of the PCR product resembled not only cysteine synthase sequences from prokaryotes and eukaryotes but also eukaryotic cystathionine beta-synthase sequences. Probing an Str. venezuelae genomic library with the PCR product located a hybridizing colony from which pJV207 was isolated. Sequencing and analysis of the Str. venezuelae DNA insert in pJV207 detected two ORFs. The deduced amino acid sequence of ORF1 matched both cysteine synthase and cystathionine beta-synthase sequences in GenBank, but its size favoured assignment as a cystathionine beta-synthase. ORF2 in the pJV207 insert was unrelated in function to ORF1; in its sequence the deduced product resembled acetyl-CoA transferases, but disruption of the ORF did not cause a detectable phenotypic change. Disruption of ORF1 failed to elicit cysteine auxotrophy in wild-type Str. venezuelae, but in the cys-28 auxotroph VS263 it prevented restoration of prototrophy with homocysteine or methionine supplements. The change in phenotype implicated loss of the transsulfuration activity that in the wild-type converts these supplements to cysteine. This study concludes that disruption of ORF1 inactivates a cbs gene, the product of which participates in cysteine synthesis by transsulfuration. Enzyme assays of Str. venezuelae mycelial extracts confirmed the formation of cysteine by thiolation of O-acetylserine, providing the first unambiguous detection of this activity in a streptomycete. Enzyme assays also detected cystathionine gamma-synthase, cystathionine beta-lyase and cystathionine gamma-lyase activity in the extracts and showed that the substrate for cystathionine gamma-synthase was O-succinyl-homoserine. Based on assay results, the cys-28 mutation in Str. venezuelae VS263 does not inactivate the cysteine synthase gene but impairs expression in cultures grown in minimal medium. PMID:12101301

Chang, Z; Vining, L C



Factor V Leiden and the risk of venous thrombosis, myocardial infarction, and stroke: a case-control study in Venezuela.  


The most common genetic defect associated with deep vein thrombosis (DVT) is a mutation in the Factor V gene (G1691A), known as Factor V Leiden (FVL). We investigated the genotypes for FVL in 571 individuals in Venezuela: 208 patients with DVT, 175 patients with acute myocardial infarction, 54 patients with stroke, and 134 control subjects. Our results showed in the population analyzed here that the FVL was associated with a fourfold increase in the risk for DVT (odds ratio, 4.24; 95% confidence interval, 1.35-14.79); particularly, women carriers showed a 6.5-fold increase in the risk for DVT. No relation was observed between the presence of FVL and the risk for acute myocardial infarction or stroke. In conclusion, a clear association between the FVL mutation and DVT was observed in the population analyzed in Venezuela. These results are in agreement with those found in other populations with different ethnic backgrounds. PMID:19604111

Pestana, Carolina I; Torres, Argimiro; Blanco, Susana; Rojas, María J; Méndez, Carlos; López, José L; de Bosch, Norma B; Porco, Antonietta



Soil gases ( 222 Rn, 220 Rn and total radon) and 214 Bi measurements across El Avila fault near Caracas, Venezuela  

Microsoft Academic Search

Summary  Radon measurements were performed across two sections of the Avila fault near Caracas, Venezuela. The radon concentrations\\u000a clearly showed the different tectonic features and lithology at the Tacamahaca and Spanish Trail sites. 214Bi (U-cps) measurements also were related to the lithology. The passive radon method employed laboratory-made dosimeters with\\u000a LR 115, type 2 celulose nitrate films as detectors. They were

F. Urbani; J. J. LaBrecque; N. Flores; P. R. Cordoves



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

Microsoft Academic Search

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''

Eugenio Sanhueza; Dieter Scharffe; Loreto Donoso; Paul J. Crutzen



Physical and chemical characteristics of ephemeral pond habitats in the Maracaibo basin and Llanos region of Venezuela  

Microsoft Academic Search

Physical and chemical variables of ephemeral rainwaterpond habitats in the Maracaibo basin and Llanos regionof Venezuela were\\u000a investigated to assess environmentalfeatures important for future studies of thephysiological ecology and bioenergetics of\\u000a annualkillifish. Dissolved oxygen, temperature, pH, Eh, andconductivity measurements were made in the field ateach collection\\u000a site. Water and filter samples werecollected and analyzed for trace metals, cations,anions, and osmolality.

Jason E. Podrabsky; Tomas Hrbek; Steven C. Hand



The organic geochemistry of oil seeps from the Sierra de Perijá eastern foothills, Lake Maracaibo Basin, Venezuela  

Microsoft Academic Search

The organic geochemistry of samples from 11 oil seeps was studied. The samples were collected from the Cachirí area, Carboniferous Region of Tulé (Lake Maracaibo Basin, Venezuela), associated with the Tigre Fault. Biomarkers (hopanes, steranes, n-alkanes, acyclic isoprenoids, and aromatic steroids) were analyzed using gas chromatography-mass spectrometry (GC-MS). These hydrocarbon rich fluids have undergone biodegradation (2–6 on the Peters and

M. Escobar; G. Márquez; S. Inciarte; J. Rojas; I. Esteves; G. Malandrino



Contextualized Qualitative Research in Venezuela: Coercive Isomorphic Pressures of the Socioeconomic and Political Environments on Public Relations Practices  

Microsoft Academic Search

This contextualized qualitative research, conducted in Venezuela in July 2004, tests and introduces the concept of coercive isomorphism to Sriramesh and Ver[cbreve]i[cbreve]'s (2003) global public relations theory. It does so by analyzing professional opinions and experiences concerning the status of the profession and how the country's socioeconomic and political environments impact the practice. Twenty-one top-level public relations professionals were interviewed

Juan-Carlos Molleda



Balancing Public Relations with Socioeconomic and Political Environments in Transition: Comparative, Contextualized Research in Colombia, Mexico, and Venezuela  

Microsoft Academic Search

This comparative, contextualized research conducted between 2003 and 2004 summarizes and discusses the impact of the socioeconomic and political environments on the practice of public relations in Colombia, Mexico, and Venezuela. Sixty-one in-depth, semi-structured interviews were conducted with top-level professionals in the capital and main commercial cities in these three countries where the profession thrives but is also challenged. The

Juan-Carlos Molleda; Ángeles Moreno



Regulation of Jadomycin B Production inStreptomyces venezuelae ISP5230: Involvement of a Repressor Gene,jadR2  

Microsoft Academic Search

The nucleotide sequence of a region upstream of the type II polyketide synthase genes in the cluster for biosynthesis of the polyketide antibiotic jadomycin B in Streptomyces venezuelae contained an open reading frame encoding a sequence of 196 amino acids that resembled sequences deduced for a group of repressor proteins.ThestrongestsimilaritywastoEnvRofEscherichiacoli,butthesequencealsoresembledMtrR,AcrR, TetC, and TcmR, all of which are involved in regulating




Physical and chemical properties of fruit and seeds eaten by Pithecia and Chiropotes in Surinam and Venezuela  

Microsoft Academic Search

Pithecia pithecia andChiropotes satanas are seed predators that eat fruits with hard pericarps. We measured resistance to puncturing and crushing of fruit and seeds eaten by these two pitheciins at two localities: in evergreen rain forest at Raleighvallen-Voltzberg, Surinam, and in tropical dry\\/transitional moist forest on islands in Guri Lake, Venezuela. Average measurements of pericarp hardness were similar at both

Warren G. Kinzey; Marilyn A. Norconk



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

PubMed Central

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

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



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


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

Eastwood, D A



Evidence for a chromosomal location of the genes coding for chloramphenicol production in Streptomyces venezuelae.  

PubMed Central

Of seven chloramphenicol-producing actinomycetes examined, only Streptomyces venezuelae strain 13s contained extrachromosomal DNA detectable by agarose gel electrophoresis and cesium chloride-ethidium bromide density gradient centrifugation. The single 17-megadalton plasmid present in this strain was indistinguishable from plasmid pUC3 previously isolated from mutagenized cultures. Strains selected for their inability to produce chloramphenicol after treatment with acriflavine or ethidium bromide still contained a plasmid that had the same electrophoretic mobility as plasmid pUC3 and yielded similar fragments when digested with restriction endonucleases. By regenerating protoplasts of strain 13s and screening for isolates lacking extrachromosomal DNA, strain PC51-5 was obtained. The absence of plasmid pUC3 sequences in this strain was confirmed by Southern hybridization using 32P-labeled plasmid as a probe. Since the plasmidless strain produced as much chloramphenicol as did the parent strain, pUC3 contains neither structural nor regulatory genes for antibiotic production. Evidence from electrophoretic analysis of BamHI digests of total cellular DNA from wild-type and dye-treated nonproducing progeny indicated that acriflavine caused structural changes in the chromosome. Images

Ahmed, Z U; Vining, L C



Epidemiologic characterization of American cutaneous leishmaniasis in an endemic region of eastern Venezuela.  


The status of American cutaneous leishmaniasis was investigated from 1985 to 1991 to provide an epidemiologic characterization of the disease in Bergantin, a rural community in the northeastern part of Anzoátegui State, Venezuela. The study revealed the presence of the infection during the period analyzed, with an average incidence of 50.2 cases per 10,000 inhabitants and this number has increased 1.5 times during the last two years. Three villages where clinical cases had been recorded were selected for a comparison of their prevalence data. These villages comprise the human population in the high and low altitude limits of Bergantin. Immunologic assessment of the inhabitants used two different antigen preparations to examine responses to parasites associated with the cutaneous and visceral forms of the disease. The leishmanin skin test (LST) was used in a sample of 276 individuals (46.3% of the inhabitants) and resulted in an overall positivity of 16.7%. The percentage of LST positivity varied with age and sex, yet analysis of this response and the prevalence for each village reflected the specific characteristics of these localities. La Montaña, situated at 800 meters above sea level, had the highest prevalence (800 cases per 10,000 inhabitants) and the most positive LST response (21.2%) in comparison with the two other villages situated at a lower altitude (300 meters above sea level). PMID:9598446

Jorquera, A; Ledezma, E; De Sousa, L; Garcia, A; Sanchez, J; Zerpa, J; Gonzalez, R; O'Daly, J A



Epidemiological survey of histoplasmine and paracoccidioidine skin reactivity in an agricultural area in Bolívar state, Venezuela.  


Paracoccidiodomycosis and histoplasmosis are endemic diseases in the south of Venezuela, representing a public health problem. Prevalence of Paracoccidiodes brasiliensis and Histoplasma capsulatum infections were estimated in Monte Ralo, a rural community area of Bolivar state using paracoccidiodine and histoplasmine skin tests. Paracoccidiodine was intradermically injected to 173 persons and readings were made at 24 and 48 h afterwards to 167 persons (97.85%). Reaction was positive in 8.5% (n = 14) at 24 h post-injection and 13.2% (n = 20) at 48 h. Farmers showed the higher percentage of positivity at 24 and 48 h. One hundred-seventy five persons were intradermically injected with histoplasmine but 167 and 157 of them attended for reading of the dermal reaction at 24 and 48 h post-injection respectively. Tests were positive in 25.7% (n = 43) at 24 h and 42.7% (n = 67) at 48 h. Further studies are needed in surrounding places to delimit the endemic area of these mycosis in the Bolivar state. However, epidemiological vigilance of PCM and H should be considered by local health authorities. PMID:15074575

Cermeño, Julman Rosiris; Hernández, Isabel; Cermeño, Julmery Jesús; Godoy, Gerardo; Cermeño, July Josefina; Orellán, Yida; Blanco, Ytalia; Cabello, Ismery; Guzmán, Yesenia; Alcalá, Frannelly; García, Teófilo; Penna, Salvador



[Tuberculosis in subjects under 15 years of age in the population of Warao in Venezuela].  


It is difficult to establish a definitive diagnosis of tuberculosis in rural areas where there is no access to a large hospital. The Warao people of the Delta Amacuro State in Venezuela, have a very high prevalence of adult TB, and we suspected that the Warao children would also have a high prevalence of the disease, almost entirely undiagnosed. We applied a simple methodology to select children suspicious for tuberculosis that is based on a rating system using clinical criteria, reactivity to tuberculin and intradomicilliary contacts. Of the 502 children under the age of 15 that were evaluated with this rating system, 27 were determined to be suspicious of TB and were further evaluated by a chest X-ray. Radiologic confirmation of TB was found in 16 (60%) of the 27 suspicious children. Of these 16 patients, 13 (81%) were PPD positive and 3 were PPD negative. Additionally, 7 of the 16 children with pathologic x-ray changes had one or more confirmatory findings: 3 were positive by culture or smear examination and 5 had a positive serologic B diagnostic test. In conclusion this methodology proved to be highly efficient in diagnosing childhood tuberculosis in this population, and should also be useful in other rural populations with a high prevalence of adult TB. PMID:11921746

Fernández de Larrea, Carlos; Fandiño, Cecil; López, Diana; del Nogal, Berenice; Rodríguez, Nilia; Convit, Jacinto; Araujo, Zaida; de Waard, Jacobus H



Cutaneous leishmaniasis in western Venezuela caused by infection with Leishmania venezuelensis and L. braziliensis variants.  


Between 1975 and 1987, epidemiological studies were carried out in several rural and urban communities in the central part of western Venezuela, especially in the state of Lara. 115 positive cultures were obtained from human cases and identified by their reactivity patterns to a cross-panel of specific monoclonal antibodies using a radioimmune binding assay; 53 were Leishmania venezuelensis and 62 were L. braziliensis. Most of these stocks were also characterized by isoenzyme electrophoresis, which confirmed the identification of the L. venezuelensis isolates. The enzyme electrophoretic profiles of the L. braziliensis isolates, however, revealed two populations with distinct electromorphs, one related to the World Health Organization L. braziliensis reference strain while the other population appeared to be a hybrid between L. braziliensis and L. guyanensis. L. braziliensis variants showed the widest geographical distribution, and were found in 7 states: Districto Federal (Caracas); Lara (Barquisimeto, Crespo, Iribarren, Jimenez, Morán, Palavecino, Torres, Urdaneta); Nueva Esparta (Margarita); Portuguesa (Las Cruces, Rio Amarillo); Trujillo (Cuicas); Yaracuy (Agua Fria, Cambural, Guaremal); and Zulia (Zipa-Yare). L. venezuelensis was found in the following endemic regions: Lara (Barquisimeto, Iribarren, Jimenez, Morán); Merida (Zéa); and Yaracuy (Campos Elias), showing that this parasite has a much wider geographical distribution than was initially recognized and that both these species can occur simultaneously within the same endemic region. Five isolates of L. braziliensis were made from infected donkeys (Equus asinus) in Urdaneta, Lara State, suggesting a possible domestic reservoir of L. braziliensis. PMID:1440772

Bonfante-Garrido, R; Meléndez, E; Barroeta, S; de Alejos, M A; Momen, H; Cupolillo, E; McMahon-Pratt, D; Grimaldi, G



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


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

Gómez, Yrma; Paolini, Jorge



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

NASA Astrophysics Data System (ADS)

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

Vranes, Kevin; Czuchlewski, Kristina R.


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

SciTech Connect

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

Garban, G.; Lopez, L.; Lo Monaco, S.; Lira, A. [Universidad Central de Venezuela, Caracas (Venezuela)



Ages and depositional environments of Paleogene rocks in the southern Maracaibo Basin, Venezuela  

SciTech Connect

Detailed studies of Paleogene rocks exposed in road cuts and rivers along the north flank of the Merida Andes in Venezuela provide a means of assisting the interpretation of subsurface data and therefore assessment of the hydrocarbon potential of the Southern Maracaibo Basin. Thick sections at Rio Chama, Rio Lora and Rio Lobaterita, together with many smaller outcrop localities, were measured and sampled to determine the ages and depositional environments of Paleogene formations. Observations and measurements taken at the outcrop include gamma ray signature, bed thickness, mineralogy, and associated sedimentary structures. Extensive sets of samples were taken for paleontological (especially palynology) analyses. This paper highlights the significant geological characteristics of the Barco, Los Cuervos, Mirador, and Carbonera formations, illustrated with measured sections showing gamma ray, geochemical, and palynological abundance logs. These observations together with proprietary subsurface data have made it possible to construct maps of Paleogene paleogeography of the Southern Maracaibo Basin, providing an understanding of the depositional environments and regional extent of potential hydrocarbon reservoirs and seals.

Pocknall, D.T. [Amoco, Exploration & Production Technology Group, Houston, TX (United States); Erlich, R.N. [Amoco, Worldwide Exploration Business Group, Houston, TX (United States)



Isolation and characterization of iridoviruses from the giant toad Bufo marinus in Venezuela.  


In this communication we describe for the first time the isolation of 7 iridoviruses from the toad Bufo marinus and an unknown species of frog Leptodactylus in Venezuela, South America. The viruses are icosahedral with electron-dense cores, each of which is surrounded by an inner membrane, capsid and a cell-derived envelope. The virus(es) have an average vertex to vertex diameter of 160 nm and replicate in the cytoplasm of a range of cell lines. Within the cytoplasm of infected cells, rarefied areas could be observed; structures lacked cellular organelles and contained complete, empty and developing viruses. Results from antigen-capture enzyme-linked immunosorbent assays (ELISA) with polyclonal antibody raised against epizootic haematopoietic necrosis virus (EHNV) indicated cross-reactivity between these isolates, Bohle iridovirus (BIV) and frog virus 3 (FV3). Comparison of polypeptide and genomic profiles indicated that the Venezuelan viruses shared many polypeptides of equivalent molecular weight with type species FV3. There were, however, differences between the group of Venezuelan viruses and FV3 and BIV. The viruses belongs to the family Iridoviridae and the genus Ranavirus. PMID:9653454

Zupanovic, Z; Musso, C; Lopez, G; Louriero, C L; Hyatt, A D; Hengstberger, S; Robinson, A J



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


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

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



Physiological age in Lutzomyia youngi (Diptera: Psychodidae) populations from an endemic area for cutaneous leishmaniasis, Venezuela.  


Batches of sylvatic females of Lutzomyia youngi (Phlebotominae) captured in a Shannon trap on twelve occasions over one year in a locality where subcutaneous leishmaniasis is endemic, near the city of Trujillo, Venezuela, were used to study: 1) the percentages of parous females according to previously established criteria and 2) the average number of eggs laid spontaneously by isolated females during 7 days after feeding on hamsters. The data on the batches of females captured on nights previous to the rainy period (prepluvial) were compared with those on females captured after the rains (postpluvial). Significant differences were detected by variation analysis for two variables and different number of N, as also were consistent groupings by Duncan's Test for pre- and postpluvial lots of females. The females captured on nights prior to the rainy periods (January-March and August-September) presented higher rates of nulliparity (86-72%) and contained or laid a greater number of eggs (71-67) than those captured after the rains (March-June and November-December) which presented lower rates of nulliparity (60-24%) and a smaller number of eggs (50-30). The rainfall peaks occurred in April and September-October, respectively. It is considered that these differences can be used by epidemiological studies as a means of estimating the physiological age of female populations of L. youngy. PMID:7660044

Scorza, J V; Oviedo, M



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

NASA Astrophysics Data System (ADS)

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

Rocabado, V.; Schmitz, M.



[Reproductive cycle of Lytechinus variegatus (Echinoidea: Toxopneustidae) in the south of Margarita Island, Venezuela].  


The sea urchin Lytechinus variegatus is of some commercial importance on the Southern coast of Margarita Island (Venezuela), where artisan women fishers process and sell the roe. The reproduction cycle of this species had not been fully studied. We collected these sea urchins in two stations from November 1997 through October 1998. The samples were transported fresh to the laboratory to determine weight, diameter and height. The sexual stage was established with a macroscopic scale and the gonadosomatic index (GI). Maturity is achieved when the animals reaches a diameter of 22 mm, although 50% of the population reaches sexual development at diameters of 43 mm (males) and 45 mm (females) at Station 1, and 35 mm for both sexes at Station 2. Mature individuals, in a sexual proportion of 1:1 were collected every month. According to the monthly GI variation and frequency (%) of the development stages, on the southern beaches the main reproductive period begins in April and continues through October, and it is most intensive from May to July, when gonads reach the greatest growth. PMID:17469260

Montealegre Quijano, Santiago; Gómez Gaspar, Alfredo



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

SciTech Connect

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.

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



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

USGS Publications Warehouse

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.

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



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


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

Rodríguez-Quintal, José G



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

USGS Publications Warehouse

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.

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



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

SciTech Connect

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.

Sweeney, J.J.; Braun, R.L.; Burnham, A.K. [Lawrence Livermore National Lab., CA (United States)] [and others



Study of an outbreak of cutaneous leishmaniasis in Venezuela. The role of domestic animals.  


During an outbreak of cutaneous leishmaniasis in a locality (Las Rosas, Cojedes State, Venezuela) previously non-endemic, 12.9% of humans, 7% of dogs and 21.4% of donkeys (Equus asinus) had lesions with parasites. The agent in the three hosts was identified as Leishmania braziliensis, subspecies braziliensis at least in man and donkey. The probable vector was Lutzomyia panamensis. No infection was found in a small sample of wild mammals examined. The outbreak was apparently linked with the importation of donkeys with ulcers, from endemic areas. The authors call attention to the fact that not only in the foci of "uta", but also in areas of the other forms of American cutaneous leishmaniasis, dogs are frequently found infected. They emphasize the necessity of searching for the infection in donkeys and of performing hemocultures and xenodiagnosis with sandflies in human, canine and equine cases, to verify their possible role as sources of infection, and not merely as dead ends in the epidemiological chain of the disease. PMID:6535915

Aguilar, C M; Fernández, E; de Fernández, R; Deane, L M



[Ichthyc biodiversity of seagrass meadows from the Northwest coast of Cariaco Gulf, Venezuela].  


Seagrasses are highly productive coastal ecosystems with a high diversity and abundance of fishes, very important to support artisanal fisheries. We analyzed the fish community structure of Thalassia testudinum in the communities of Manzanillo (M) and La Brea (LB), Northwest coast of Cariaco Gulf, Venezuela. Samples were taken monthly (Nov. 2006-Oct. 2007) from each place, using a beach net. A total of 34 810 fishes were captured, grouped into 13 orders, 36 families and 83 species. In both areas (M and LB), the number of species was similar, but a variation in their abundance was found: a total of 55 species and 13 210 organisms for M, and 58 species and 21 600 organisms for LB. The most abundant species and those with the highest biomasses in both areas were: Nicholsina usta, Haemulon boschmae, H. steindachneri, Harengula jaguana, Halichoeres bivittatus and Hemiramphus brasiliensis. The occasional visitors were the most frequent community components with a 59%, the cyclical and permanent residents were represented by the 22% and 19%, respectively. The H'n average for M was of 1.71+/-0.64bits/ind., while for LB was of 1.95+/-0.51bits/ind. The diversity values were directly related to the evenness and inversely related to the dominance. The low values of similarity indexes among localities allow us to assert that these fish communities are dissimilar, because of the structure of each Thalassia meadow and their connectivity with other systems. PMID:23894935

Ariza A, Luis Alejandro; Núñez P, José Gregorio; Ruiz, Lilia; de E Méndez, E Elizabeth



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

PubMed Central

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.

Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cardenas, Lya; Sanchez, Victor; Estrada, Yarys; Anaya, William; Martinez, Angela



Environmental risk factors for Cryptosporidium infection in an island from Western Venezuela.  


Few investigations have been conducted on risk factors for Cryptosporidium infection in communities from developing countries. A study was conducted to determine the prevalence and risk factors for cryptosporidiosis in San Carlos island, Venezuela. A sample of 515 subjects (mean age +/- SD: 21.4 +/- 17.8 years) was surveyed. Single fecal specimens were collected and modified Ziehl-Neelsen carbolfuchsin staining of formalin-ether concentrate stools were examined for identification of the parasite. Infections with Cryptosporidium (67 of 515, 13%) were common. Prevalence of the parasite varied among sectors of the community; 34 of 67(50.7%) cases of cryptosporidiosis clustered in two sectors with extreme poverty. Variables strongly associated with a higher risk for the infection (p < 0.01) were residing in these sectors versus the remainder, living in a hut or small residence versus a brick 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. Crowding was also a risk (p < 0.05). Contact with human feces contaminated-soil may be an important mode of transmission and poverty a predisposing factor for the infection. PMID:18345459

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



[Distribution and taxonomy of Pyrgophorus platyrachis (Caenogastropoda: Hydrobiidae) in the Sistema de Maracaibo, Venezuela].  


The presence of a microgastropod identified as Potamopyrgus sp. was detected previously in the Maracaibo System; nevertheless, a detailed morphological analysis identified this snail in other genera. The objective of this work is to update the distribution and taxonomy of Pyrgophorus platyrachis in the Maracaibo System, Venezuela in samples obtained between 2001 and 2009. The presence of hundreds of individuals of P. platyrachis were observed in the estuary, indeed in the localities of the Gran Eneal lagoon (4 111 snails), Peonías lagoon (229 snails), Punta Capitán Chico (758 snails), San Francisco (2 517 snails), Curarire (240 snails), Apon River mouth (173 snails), Ojeda City (240 snails), Bachaquero (128 snails) and Tomoporo de Agua (385 snails). We performed a taxonomical analysis, and emphasized in ecological aspects, such as the distribution of the species and habitat features, as near vegetation and type of associated sediment. We found three morphotypes of the species, one smooth, another with spiral striations and the other with spines. Smooth morphotype was exclusive of the Gran Eneal lagoon, Peonías lagoon, Punta Capitan Chico and Apon River mouth localities, whereas the other two morphotypes were found together in the remaining localities. According to our detailed anatomical and taxonomical analysis we propose a synonymy between P. platyrachis and the other species described like Pyrgophorus parvulus and Pyrgophorus spinosus. PMID:22017122

Nava, Mario; Severeyn, Héctor; Machado, Nakary



[Geometric wing morphometrics for Chrysomya albiceps and C. megacephala identification (Diptera: Calliphoridae) from Venezuela].  


Calliphoridae is one of the families with the greatest number of species with forensic importance, which immature stages feed and develop on decaying material. In Venezuela, there are few studies on this taxon reporting the dominance of Chrysomya over other carrion flies. The goal of this study was to analyze the variations on wing morphometrics, to support the identification of two forensic flies. For this we photographed a total of 168 wings from C. albiceps (n=111) and C. megacephala (n=57). Landmark coordinate (x, y) configurations were registered and aligned by Generalized Procrustes Analysis. Principal Component Analysis and shape significance test based on Procrustes distance were implemented. Statistical analysis of variance found significant differences in wing isometric size (Kruskal-Wallis). The PCA showed the separation between species, and shape test showed significant differences (F Goodall's). The main differences between both species were localized on subcosta rupture, join of R(2+3) with wing border, join of dm-cu, and join of Cu with bm-cu, suggesting that wing morphometrics is a suitable tool in the discrimination of blowfly species. PMID:23025095

Vásquez, Marianela; Liria, Jonathan



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


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

Cazorla, Dalmiro; Ruiz, Aixa; Acosta, María



The Buen Pastor cemetery in Trujillo, Venezuela: measuring dengue vector output from a public area.  


As vector control of dengue typically targets individual households to eliminate breeding sites or control adult mosquitoes during epidemics, public spaces are frequently neglected. To investigate the importance of such places as sources of dengue vectors, a study of Aedes aegypti productivity in a cemetery in northern Venezuela, using standard entomological indices for assessing dengue vector infestations, was carried out in the wet season in May 2003. Containers were found on 72.8% of graves; 44% of the containers held water and in 46.9% of these we found A. aegypti larvae and/or pupae. The average density of Aedes-infested containers was 39 per hectare. There were no significant differences in infestation rates between container types (vases, planters or others) or materials (cement, plastic, glass, etc.). Containers with 1-5 l of water held the greatest proportion of the pupae found in the cemetery (46.7%); containers with <100 ml of water contained no pupae. The mean number of pupae produced in the cemetery was estimated at 4185 pupae/ha per 48 h and the daily output of potential vector mosquitoes from the entire cemetery was calculated at approximately 3000 females per day. These mosquitoes presumably left the cemetery to feed in the nearby communities, thus thwarting the environmental management and health education programmes that had reduced household dengue vector infestations. The study shows the importance of public places as sources of dengue vectors in urban areas, and the need to include such areas in vector control programmes. PMID:15941424

Abe, Mayumi; McCall, P J; Lenhart, Audrey; Villegas, Elci; Kroeger, Axel



Developing a marginal field using new techniques-South Monagas Unit, Venezuela  

SciTech Connect

In 1992 the Venezuelan national oil company, PDVSA, awarded operating service agreements to foreign oil companies for reactivation of marginal oil fields. The South Monagas Unit contains three oil and gas fields, Uracoa, Bombal, and Tucupita, that were not producing prior to the award of the contract As of October 1995, production from Uraroa had exceeded 20 MBbls/day of heavy oil from 26 vertical and 11 horizontal wells. Initial uncertainties about heavy oil treatment capability, water and gas production, oil flow rates, and ultimate recoverable reserves led to a phased development plan that has incrementally reduced the risk of financial exposure over time. The first phase of development utilized conventional geologic techniques and vertical wells to test treatment facilities, mud and gravel-pack technologies, and flow rates. Positive results led to the next phase of development which focused on reservoir performance and well optimization. A horizontal well drilling program was implemented in December 1993. A milestone in this program was the first gravel-pack horizontal well in Venezuela, completed in February, 1995. A pilot 2-D seismic program in late 1994 confined that high-quality seismic could be acquired to significantly enhance the development of Uracoa. A 175 W 3-D survey was shot and processed in mid-1995. Concurrently, borehole imaging logs were acquired in vertical wells to determine internal reservoir heterogeneity and sand depositional models. The sequence stratigraphic model that evolved, based on outcrop field analogs, 3-D seismic stratigraphy, and regional well control, is being used to optimize field development. In addition, new exploration concepts are being tested without risk using strategically located water injection wells as test wells.

Skirvin, T.M.; Sven Hagen, E.; McGee, R.A.; Hinrichs, P.D. (Benton Oil and Gas Co., Carpineteria, CA (United States)); Medina, P.A. (Benton Vinccler, C.A., Maturin (Venezuela))



The role of seismic microzoning within the disaster prevention in Venezuela  

NASA Astrophysics Data System (ADS)

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.

Malave, G.



Distribution and mobility of mercury in soils of a gold mining region, Cuyuni river basin, Venezuela.  


An extensive and remote gold mining region located in the East of Venezuela has been studied with the aim of assessing the distribution and mobility of mercury in soil and the level of Hg pollution at artisanal gold mining sites. To do so, soils and pond sediments were sampled at sites not subject to anthropological influence, as well as in areas affected by gold mining activities. Total Hg in regionally distributed soils ranged between 0.02 mg kg(-1) and 0.40 mg kg(-1), with a median value of 0.11 mg kg(-1), which is slightly higher than soil Hg worldwide, possibly indicating long-term atmospheric input or more recent local atmospheric input, in addition to minor lithogenic sources. A reference Hg concentration of 0.33 mg kg(-1) is proposed for the detection of mining affected soils in this region. Critical total Hg concentrations were found in the surrounding soils of pollutant sources, such as milling-amalgamation sites, where soil Hg contents ranged from 0.16 mg kg(-1) to 542 mg kg(-1) with an average of 26.89 mg kg(-1), which also showed high levels of elemental Hg, but quite low soluble+exchangeable Hg fraction (0.02-4.90 mg kg(-1)), suggesting low Hg soil mobility and bioavailability, as confirmed by soil column leaching tests. The vertical distribution of Hg through the soil profiles, as well as variations in soil Hg contents with distance from the pollution source, and Hg in pond mining sediments were also analysed. PMID:21215510

Santos-Francés, F; García-Sánchez, A; Alonso-Rojo, P; Contreras, F; Adams, M



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

NASA Astrophysics Data System (ADS)

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.

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



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

NASA Astrophysics Data System (ADS)

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.

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



Uranium and thorium series isotopes as indicators of geochemical processes in recent Venezuela Basin sediments  

SciTech Connect

Several uranium and thorium series isotopes are important indicators of abyssal geochemical and physical processes: sedimentation, bioturbation, compaction, dissolution and precipitation. This research was designed to investigate the relative importance of each of these on early sediment diagenesis in different abyssal environments. Sediment samples were collected from three different sedimentary environments from the Venezuela Basin. Samples were designated as pelagic carbonate, hemipelagic and turbidite-rich, based on bulk sediment characteristics. Selected members of the U and Th radioisotope series ({sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Pb, and {sup 232}Th), {sup 14}C, and anthropogenic {sup 239,240}Pu were determined on selected intervals. Other sedimentary parameters, including porosity, calcium carbonate content, stable isotopes, macrofaunal abundances, organic carbon and grain size, were measured or available from the literature. A model, based on the constancy of {sup 230}Th production in sea water, was developed to determine fine-scale sedimentation rates for the last 14 ky, 6 ky, and 2 ky for sediments from pelagic carbonate, hemipelagic and turbidite-rich environments, respectively. Nannofossil {delta}{sup 13}C values correlated well with carbonate accumulation rates. {sup 226}Ra fluxes across the sediment/sea water interface were estimated from losses in the expected {sup 226}Ra activities. {sup 226}Ra fluxes across the interface were low due to low {sup 230}Th activities. A multi-layer explicit finite difference model was developed to simulate the effects of diffusive and advective bioturbation on the distributions of {sup 210}Pb and {sup 239,240}Pu in abyssal sediments.

Cole, K.P.H.



Sub-B? layering in the Southern Caribbean: The Aruba Gap and Venezuela Basin  

NASA Astrophysics Data System (ADS)

Multichannel seismic data in the Aruba Gap region near JOIDES/DSDP Site 153 verify the presence of a deep sub-B? reflection. One multichannel seismic line trends NE-SW on and along the edge of Beata Ridge and passes within 1 km of Site 153, and another line runs N-S across the entire Aruba Gap with the drill site 4 km east from its northern end. Closely spaced velocity analyses indicate the presence of deep primary reflection events and enable calculation of interval velocities between the A?-B? marker horizons. Deconvolved, true amplitude, normal incidence profiles sharply delineate the A?-B? marker horizons and indicate the presence of the sub-B? reflection event. On the NE-SW line, this deep reflector is best described as a "diffuse" discontinuous zone, relatively horizontal, lying about 0.8 seconds of two-way travel time below the B? reflector, with an interval velocity of approximately 5.0 km/s between Horizon B? and this reflection. The N-S line is more complex since the sub-B'' reflection event is masked by a strong internal multiple from the A?-B? interval. In the central and western Venezuela Basin, deep primary reflections beneath Horizon B? are also observed on the northern and western sides of what appears to be a major fault zone. This fault zone separates the smooth B? and sub-B? reflectors on the northern and western sides of this fault zone from what appears to be typical oceanic basement. The widespread presence of sub-B? reflections yielding high interval velocities for the section between these events and Horizon B? suggest that this material is probably igneous in origin.

Stoffa, Paul L.; Mauffret, A.; Truchan, M.; Buhl, Peter



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

SciTech Connect

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.

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



Inactivation of chloramphenicol by O-phosphorylation. A novel resistance mechanism in Streptomyces venezuelae ISP5230, a chloramphenicol producer.  


Plasmid pJV4, containing a 2.4-kilobase pair insert of genomic DNA from the chloramphenicol (Cm) producer Streptomyces venezuelae ISP5230, confers resistance when introduced by transformation into the Cm-sensitive host Streptomyces lividans M252 (Mosher, R. H. Ranade, N. P., Schrempf, H., and Vining, L. C. (1990) J. Gen. Microbiol. 136, 293-301). Transformants rapidly metabolized Cm to one major product, which was isolated and purified by reversed phase chromatography. The metabolite was identified by nuclear magnetic resonance spectroscopy and mass spectrometry as 3'-O-phospho-Cm, and was shown to have negligible inhibitory activity against Cm-sensitive Micrococcus luteus. The nucleotide sequence of the S. venezuelae DNA insert in pJV4 contains an open reading frame (ORF) that encodes a polypeptide (19 kDa) with a consensus motif at its NH2 terminus corresponding to a nucleotide-binding amino acid sequence (motif A or P-loop; Walker, J. E., Saraste, M., Runswick, M. J., and Gay, N. J. (1982) EMBO J. 1, 945-951). When a recombinant vector containing this ORF as a 1.6-kilobase pair SmaI-SmaI fragment was used to transform S. lividans M252, uniformly Cm-resistant transformants were obtained. A strain of S. lividans transformed by a vector in which the ORF had been disrupted by an internal deletion yielded clones that were unable to phosphorylate Cm, and exhibited normal susceptibility to the antibiotic. The results implicate the product of the ORF from S. venezuelae as an enzymic effector of Cm resistance in the producing organism by 3'-O-phosphorylation. We suggest the trivial name chloramphenicol 3'-O-phosphotransferase for the enzyme. PMID:7592948

Mosher, R H; Camp, D J; Yang, K; Brown, M P; Shaw, W V; Vining, L C



Characterization and Analysis of the PikD Regulatory Factor in the Pikromycin Biosynthetic Pathway of Streptomyces venezuelae  

PubMed Central

The Streptomyces venezuelae pikD gene from the pikromycin biosynthetic cluster was analyzed, and its deduced product (PikD) was found to have amino acid sequence homology with a small family of bacterial regulatory proteins. Database comparisons revealed two hypothetical domains, including an N-terminal triphosphate-binding domain and a C-terminal helix-turn-helix DNA-binding motif. Analysis of PikD was initiated by deletion of the corresponding gene (pikD) from the chromosome of S. venezuelae, resulting in complete loss of antibiotic production. Complementation by a plasmid carrying pikD restored macrolide biosynthesis, demonstrating that PikD is a positive regulator. Mutations were made in the predicted nucleotide triphosphate-binding domain, confirming the active-site amino acid residues of the Walker A and B motifs. Feeding of macrolide intermediates was carried out to gauge the points of operon control by PikD. Although the pikD mutant strain was unable to convert macrolactones (10-deoxymethynolide and narbonolide) to glycosylated products, macrolide intermediates (YC-17 and narbomycin) were hydroxylated with high efficiency. To study further the control of biosynthesis, presumed promoter regions from pik cluster loci were linked to the xylE reporter and placed in S. venezuelae wild-type and pikD mutant strains. This analysis demonstrated that PikD-mediated transcriptional regulation occurs at promoters controlling expression of pikRII, pikAI, and desI but not those controlling pikRI or pikC.

Wilson, Daniel J.; Xue, Yongquan; Reynolds, Kevin A.; Sherman, David H.



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


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

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



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

PubMed Central

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

Suarez-Morales, Eduardo; Camisotti, Humberto; Martin, Alberto



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


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

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



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

USGS Publications Warehouse

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.

Goulding, W.; Martin, T. E.



Association between apoliprotein E gene polymorphism and hypercholesterolemic phenotype in Maracaibo, Zulia state, Venezuela.  


Apoliprotein (Apo) E gene polymorphisms have been associated with high plasma lipids levels and cardiovascular disease. The aim of this study was to determine allelic and genotypic frequencies and to evaluate the associations of polymorphisms with hypercholesterolemic phenotypes in a patient population in Maracaibo, Zulia State. Two hundred and twenty-one patients with ages between 9 and 78 years old attending the Endocrine-Metabolic Center at the University of Zulia, Zulia, Venezuela, were recruited. The lipid profile was determined by enzymatic methods. ApoE polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism. One hundred and thirty-three dyslipidemic and 88 patients with normal lipids profile were evaluated. The higher proportion of patients corresponded to hypercholesterolemia isolated (46.61%), followed by hypercholesterolemia combined with hypertriglyceridemia and low levels of high-density lipoprotein (21.8%). ApoE epsilon3 allele was the most frequent in the evaluated population (0.80), both in the control group (0.78) and in the dyslipidemic group (0.82), followed by the epsilon4 allele (0.12) for both groups and the epsilon2 allele with values of 0.10 and 0.06, for control and dyslipidemic group, respectively. The epsilon3epsilon3 and epsilon3epsilon4 genotypes were the most frequent in the population, with values of 62.89% and 22.17%, respectively. The genotype frequencies were 57.95% and 66.17% for epsilon3epsilon3; 23.86% and 21.05% for epsilon3epsilon4 in nondyslipidémicos and dyslipidemic patient groups, respectively. The epsilon4epsilon4 genotype was observed only in hypercholesterolemic patients. The homozygote epsilon2epsilon2 and heterozygote epsilon2epsilon3 genotypes were more frequent at the normal lipids profile group, consistent with diverse reports that indicate the association of the epsilon4 allele with elevated cholesterol levels and low cholesterol levels when the epsilon2 allele is present. ApoE polymorphism seems to be associated with variance in serum lipids levels in the population evaluated. PMID:20019593

Arráiz, Nailet; Bermúdez, Valmore; Prieto, Carem; Sánchez, Maria Patricia; Escalona, Carolina; Sanz, Eileen; Rondón, Netxibeth; Reyes, Francia; Velasco, Manuel



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

NASA Astrophysics Data System (ADS)

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

Audemard, Franck A.; Bousquet, Jean-Claude; Rodr?´guez, José A.



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

NASA Astrophysics Data System (ADS)

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

Kammesheidt, Ludwig



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

NASA Astrophysics Data System (ADS)

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

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



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

NASA Astrophysics Data System (ADS)

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

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



Regulation of jadomycin B production in Streptomyces venezuelae ISP5230: involvement of a repressor gene, jadR2.  


The nucleotide sequence of a region upstream of the type II polyketide synthase genes in the cluster for biosynthesis of the polyketide antibiotic jadomycin B in Streptomyces venezuelae contained an open reading frame encoding a sequence of 196 amino acids that resembeled sequences deduced for a group of repressor proteins. The strongest similarity was to EnvR of Escherichia coli, but the sequence also resembled MtrR, AcrR, TetC, and TcmR, all of which are involved in regulating resistance to antibiotics or toxic hydrophobic substances in the environment. Disruption of the nucleotide sequence of this putative S. venezuelae repressor gene (jadR2), by insertion of an apramycin resistance gene at an internal MluI site, and replacement of the chromosomal gene generated mutants that produced jadomycin B without the stress treatments (exposure to heat shock or to toxic concentrations of ethanol) required for jadomycin B production by the wild type. When cultures of the disruption mutants were ethanol stressed, they overproduced the antibiotic. From these results it was concluded that expression of the jadomycin B biosynthesis genes are negatively regulated by jadR2. PMID:7592375

Yang, K; Han, L; Vining, L C



Carriage and invasive isolates of Streptococcus pneumoniae in Caracas, Venezuela: the relative invasiveness of serotypes and vaccine coverage.  


The introduction of a pneumococcal conjugate vaccine in Venezuela needs previous studies to assess vaccine efficiency. We conducted a survey of nasopharyngeal pneumococcal carriage in urban children in Caracas and studied the distribution of serotypes. We compared these data with survey data available for invasive strains isolated in the same area and in the same time period. An overall pneumococcal carriage rate of 27% was observed. The most predominant capsular serotypes among carriage isolates were 6B (29%), 19A (13.8%), 23F (10%), 14 (8.3%), 6A (8.3%) and 15B/C (3.3%) and among invasive isolates 6B (25%), 14 (15%), and 19A, 6A, 7F, and 18 (7.5% each). The serotypes/groups 1, 5, 7F and 18, jointly covering 30% of the invasive strains, represented less than 0.7% of the carrier strains. The theoretical coverage of the pneumococcal conjugate vaccine PCV13 for carriage and invasive strains was calculated to be 74% and 90%, respectively. Our study demonstrates important differences for the serotype distribution in disease and carriage isolates and provides a key baseline for future studies addressing the prevalence and replacement of invasive and carriage serotypes after the introduction of the PCV 13 vaccine in Venezuela in the year 2010. PMID:21499972

Rivera-Olivero, I A; del Nogal, B; Sisco, M C; Bogaert, D; Hermans, P W M; de Waard, J H



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

NASA Astrophysics Data System (ADS)

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

Puerta, Julio



Feasibility Study for the Modernization of the Public Health Care System in Venezuela. Audit and Evaluation of Equipment and Installations Component. Volume 3. Technical Specifications. Final Report.  

National Technical Information Service (NTIS)

The report, conducted by Booz-Allen, was funded by the U.S. Trade and Development Agency. This report concerns the modernization of Venezuela's health care system, Proyecto Salud. The main objectives of Proyecto Salud are: to modernize the health care del...



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

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

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



Diurnal changes in photochemical efficiency, the reduction state of Q, radiationless energy dissipation, and non-photochemical fluorescence quenching in cacti exposed to natural sunlight in northern Venezuela  

Microsoft Academic Search

Diurnal measurements of chlorophyll a fluorescence from cacti (Nopalea cochenillifera, Opuntia ficus-indica, and Opuntia wentiana) growing in northern Venezuela were used to determine photochemical fluorescence quenching related to the reduction state of the primary electron acceptor of PS II as well as non-photochemical fluorescence quenching which reflects the fraction of energy going primarily into radiationless deexcitation. The cladodes used in

W. W. Adams; M. Díaz; K. Winter



A test for the adequacy of bioindicator taxa: Are tiger beetles (Coleoptera: Cicindelidae) appropriate indicators for monitoring the degradation of tropical forests in Venezuela?  

Microsoft Academic Search

Indicator species can be a valuable tool for conservation research. Their use has been divided in two categories: inventory studies and monitoring studies. Tiger beetles (Coleoptera: Cicindelidae) have been identified as appropriate indicators for inventory studies. Here we test their value as potential bioindicators for monitoring habitat degradation in Venezuela. We analyze the general habitat associations of 47 of the

Jon Paul Rodríguez; David L. Pearson; Roberto R. Barrera



Variability in the mean latitude of the Atlantic Intertropical Convergence Zone as recorded by riverine input of sediments to the Cariaco Basin (Venezuela)  

Microsoft Academic Search

Changes in the strength and position of the Intertropical Convergence Zone (ITCZ) are an important component of climate variability in the tropical Atlantic. The Cariaco Basin, located on the northern margin of Venezuela, is sensitive to tropical Atlantic climate change and its sediments provide a record of past ITCZ behavior. Today, the Cariaco Basin experiences two distinct seasons that reflect

Larry C. Peterson; Gerald H. Haug




Microsoft Academic Search

SUMMARY Catch rates from 1991 to 2004 for white marlin (Tetrapturus albidus) and blue marlin (Makaira nigricans) from the small scale fishery off La Guaira, Venezuela (a billfish hot-spot) were standardized by Generalized Liner Model techniques. The index of weight of fish per number of sets was estimated from dressed weight of marlins caught and reported by port sampling in

Freddy Arocha; Luis A. Marcano; Mónica Valle; Kristin Kleisner; David Die



A Single-Use Site Selection Technique, Using GIS, for Aquaculture Planning: Choosing Locations for Mangrove Oyster Raft Culture in Margarita Island, Venezuela  

Microsoft Academic Search

Oyster culture has a potential to generate income for coastal communities and to lessen pressure on natural overexploited populations. A project to transfer mangrove oyster Crassostrea rhizophorae raft culture technology to selected coastal communities in Margarita Island, Venezuela is being developed, and an optimum location selection technique was devised. To pick the variables or factors that determine site suitability, a

Joaquín Buitrago; Martín Rada; Hernando Hernández; Esperanza Buitrago



Feasibility Study for the Modernization of the Public Health Care System in Venezuela. Audit and Evaluation of Equipment and Installations Component. Volume 1. Final Report.  

National Technical Information Service (NTIS)

The report, conducted by Booz-Allen, was funded by the U.S. Trade and Development Agency. This report concerns the modernization of Venezuela's health care system, Proyecto Salud. The main objectives of Proyecto Salud are: to modernize the health care del...



Phosphorus fractions and sorption processes in soil samples taken in a forest-savanna sequence of the Gran Sabana in southern Venezuela  

Microsoft Academic Search

P fractions and sorption processes were studied in samples taken from the organic surface layer and in the underlying mineral soil of a forest-savanna sequence consisting of: (1) tall primary forest (TPF), (2) tall secondary forest (MSF), (3) low secondary forest (LSF), and (4) open savanna (S) in la Gran Sabana, South Venezuela. The organic surface layer in the TPF

Noemí Chacón; Nelda Dezzeo



Implications of soil organic carbon and the biogeochemistry of iron and aluminum on soil phosphorus distribution in flooded forests of the lower Orinoco River, Venezuela  

Microsoft Academic Search

Relationships among soil phosphorus distribution, soil organic carbon and biogeochemistry of iron and aluminum were studied along a flooded forest gradient of the Mapire river, Venezuela. Soil samples were collected during the dry season in three zones subjected to different flooding intensity: MAX inundated 8 months per year, MED inundated 5 months per year, and MIN inundated 2 months per year. Total labile




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

PubMed Central

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

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



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


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

Kerdel-Vegas, Francisco



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

USGS Publications Warehouse

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.

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



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

NASA Technical Reports Server (NTRS)

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

Vincent, R. K.



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


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

Conroy, G; Conroy, D A



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

PubMed Central

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



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


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

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



Site-specific integration of bacteriophage VWB genome into Streptomyces venezuelae and construction of a VWB-based integrative vector.  


The temperate bacteriophage VWB integrates into the chromosome of Streptomyces venezuelae ETH14630 via site-specific integration. Following recombination of the VWB attP region with the chromosomal attB sequence, the host-phage junctions attL and attR are formed. Nucleotide sequence analysis of attP, attB, attL and attR revealed a 45 bp common core sequence. In attB this 45 bp sequence consists of the 3' end of a putative tRNA Arg(AGG) gene with a 3'-terminal CCA sequence which is typical for prokaryotic tRNAs. Phage DNA integration restores the putative tRNA Arg(AGG) gene in attL. However, following recombination the CCA sequence is missing as is the case for most Streptomyces tRNA genes described so far. Adjacent to VWB attP, an ORF encoding a 427 aa protein was detected. The C-terminal region of this protein shows high similarity to the conserved C-terminal domain of site-specific recombinases belonging to the integrase family. To prove the functionality of this putative integrase gene (int), an integrative vector pKT02 was constructed. This vector consists of a 2.3 kb HindIII-SphI restriction fragment of VWB DNA containing attP and int cloned in a non-replicative Escherichia coli vector carrying a thiostrepton-resistance (tsr) gene. Integration of pKT02 was obtained after transformation of Streptomyces venezuelae ETH14630 and Streptomyces lividans TK24 protoplasts. This vector will thus be useful for a number of additional Streptomyces species in which a suitable tRNA gene can be functional as integration site. PMID:9884227

Van Mellaert, L; Mei, L; Lammertyn, E; Schacht, S; Anné, J



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

NASA Astrophysics Data System (ADS)

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.

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



Identification of factor VIII gene mutations in patients with severe haemophilia A in Venezuela: identification of seven novel mutations.  


Haemophilia A is caused by mutations in the gene encoding coagulation factor VIII (FVIII). In severe Haemophilia A (sHA), two inversions are responsible for approximately 50% of the genetic alterations (intron 22 and intron 1 inversions). The other mutations are extremely diverse and each affected family generally has its own mutation. Our aim was to detect the genetic alterations present in the FVIII gene (F8) in 54 unrelated male patients with sHA in Venezuela. We initially detected the presence of the intron 22 inversion by performing inverse PCR, and the negative patients for this inversion were analysed for the intron 1 inversion by PCR. Patients negative for both inversions were analysed using Conformation Sensitive Gel Electrophoresis for mutations in all exons, promoter region and 3'-UTR. sHA causative mutations were identified in 49 patients. Intron-22 and -1 inversions were detected in 41% and 0% of patients respectively. Besides these two mutations, 25 different mutations were identified, including nine nonsense, four small deletions, two small insertions, four missense, three splicing mutations and three large deletions. Seven novel mutations were identified, including two nonsense mutations, two small deletions, one small insertion, one missense mutation and one splicing mutation. Thirty one percent of the patients with identified mutations developed inhibitors against exogenous FVIII. This is the first report of F8 mutations in patients with sHA in Venezuela; the data from this study suggests that the spectrum of gene defects found in these patients is as heterogeneous as reported previously for other populations. PMID:21371196

Albánez, S; Ruiz-Sáez, A; Boadas, A; de Bosch, N; Porco, A



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


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

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



Project for the Institutional Development and Rehabilitation of the Water Supply and Sanitation Systems in the State of Barinas, Venezuela. Executive Summary and Final Report (Proyecto para el Desarrollo Institucional y la Rehabilitacion de los Sisstemas del Sector Agua Potable y Saneamiento del Estado Barinas, Venezuela. Informe Final).  

National Technical Information Service (NTIS)

The study, conducted by ICF Kaiser, was funded by the U.S. Trade and Development Agency on behalf of Venezuela's Ministry of Environment and Renewable Resources. The main objective of the study was to evaluate the existing conditions of the water supply a...



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


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

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



Trypanosoma cruzi genotyping supports a common source of infection in a school-related oral outbreak of acute Chagas disease in Venezuela.  


Trypanosoma cruzi I, a discrete typing unit (DTU) found in human infections in Venezuela and other countries of the northern region of South America and in Central America, has been recently classified into five intra-DTU genotypes (Ia, Ib, Ic, Id, Ie) based on sequence polymorphisms found in the spliced leader intergenic region. In this paper we report the genotype identification of T. cruzi human isolates from one outbreak of acute orally acquired Chagas disease that occurred in a non-endemic region of Venezuela and from T. cruzi triatomine and rat isolates captured at a guava juice preparation site which was identified as the presumptive source of infection. The genotyping of all these isolates as TcId supports the view of a common source of infection in this oral Chagas disease outbreak through the ingestion of guava juice. Implications for clinical manifestations and dynamics of transmission cycles are discussed. PMID:23544849

Díaz-Bello, Z; Thomas, M C; López, M C; Zavala-Jaspe, R; Noya, O; DE Noya, B Alarcón; Abate, T



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

NASA Astrophysics Data System (ADS)

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

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



The Streptomyces venezuelae pikAV gene contains a transcription unit essential for expression of enzymes involved in glycosylation of narbonolide and 10-deoxymethynolide  

Microsoft Academic Search

In Streptomyces venezuelae, four polyketide synthase (PKS) polypeptides encoded by pikAI-pikAIV are used to generate 10 and 12-membered macrocyclic structures, narbonolide and 10-deoxymethynolide. Sequence analysis suggests these genes are translationally coupled with downstream genes, pikAV (encoding a type II thioesterase), desVIII-desVI (encoding enzymes responsible for production of the final glycosylated products pikromycin, narbomycin, methymycin and neomethymycin) and desR (a resistance

Shuo Chen; Jeffrey B. Roberts; Yongquan Xue; David H. Sherman; Kevin A. Reynolds



Genome-wide analysis of the role of GlnR in Streptomyces venezuelae provides new insights into global nitrogen regulation in actinomycetes  

PubMed Central

Background GlnR is an atypical response regulator found in actinomycetes that modulates the transcription of genes in response to changes in nitrogen availability. We applied a global in vivo approach to identify the GlnR regulon of Streptomyces venezuelae, which, unlike many actinomycetes, grows in a diffuse manner that is suitable for physiological studies. Conditions were defined that facilitated analysis of GlnR-dependent induction of gene expression in response to rapid nitrogen starvation. Microarray analysis identified global transcriptional differences between glnR+ and glnR mutant strains under varying nitrogen conditions. To differentiate between direct and indirect regulatory effects of GlnR, chromatin immuno-precipitation (ChIP) using antibodies specific to a FLAG-tagged GlnR protein, coupled with microarray analysis (ChIP-chip), was used to identify GlnR binding sites throughout the S. venezuelae genome. Results GlnR bound to its target sites in both transcriptionally active and apparently inactive forms. Thirty-six GlnR binding sites were identified by ChIP-chip analysis allowing derivation of a consensus GlnR-binding site for S. venezuelae. GlnR-binding regions were associated with genes involved in primary nitrogen metabolism, secondary metabolism, the synthesis of catabolic enzymes and a number of transport-related functions. Conclusions The GlnR regulon of S. venezuelae is extensive and impacts on many facets of the organism's biology. GlnR can apparently bind to its target sites in both transcriptionally active and inactive forms.



Photosynthetic light-use by three bromeliads originating from shaded sites ( Ananas ananassoides, Ananas comosus cv. Panare) and exposed sites ( Pitcairnia pruinosa ) in the medium Orinoco basin, Venezuela  

Microsoft Academic Search

Three Bromeliaceae species of the medium Orinoco basin, Venezuela, were compared in their light-use characteristics. The bromeliads studied were two species of pineapple, i.e. the wild species Ananas ananassoides originating from the floor of covered moist forest, and the primitive cultivar Panare of Ananas comosus mostly cultivated in semi-shaded palm swamps, and Pitcairnia pruinosa, a species abundant in highly sun

P. Keller; U. Lüttge



Macrofauna Associated with Echiuran Burrows: A Review with New Observations of the Innkeeper Worm, Ochetostoma erythrogrammon Leuckart and Rüppel, in Venezuela  

Microsoft Academic Search

Arthur Anker, Galena-Vantsetti Murina, Carlos Lira, Jonathan A. Vera Caripe, A. Richard Palmer, and Ming-Shiou Jeng (2005) Macrofauna Associated with Echiuran burrows: a review with new observations of the innkeeper worm, Ochetostoma erythrogrammon Leuckart and Rüppel, in Venezuela. Zoological Studies 44(2): 157-190. Because of their size and semipermanent nature, burrows of larger echiuran worms (phylum Echiura: Urechidae, Echiuridae, Bonelliidae, and

Arthur Anker; Galena-Vantsetti Murina; Carlos Lira; Jonathan A. Vera Caripe; A. Richard Palmer; Ming-Shiou Jeng



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

ERIC Educational Resources Information Center

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…

DeGroote, Bill; Morrison, Carolyn



Age, growth and fecundity of the silver mullet, Mugil curema (Pisces: Mugilidae), in coastal areas of northeastern Venezuela.  


We studied fecundity and growth in populations of the silver mullet, Mugilcurema, in coastal areas of northeastern Venezuela between March 1992 and July 1993. The average number of oocytes in gonads of 23-42 cm adults was 54 x 10(4), and the relative fecundity was 1,311 oocytes g-1 of fish. The size of mature oocytes did not vary in different portions of the same gonad (p > 0.05) or among the adults in three populations studied. The average egg diameter for adults was 426 microns (CI = 4.34). Age of juveniles, collected from the La Restinga Lagoon at about monthly intervals, from counts of growth lines on the otoliths ranged from 50 to 240 days. The relation of age (number of growth lines) to standard length follows an exponential growth curve. The growth of juveniles varied seasonally and was greatest during the rainy season (April to August), when temperatures were highest. The time of spawning has probably been adapted so that peak recruitment into the lagoons occurs just prior to the rainy season when conditions for growth are most favorable. PMID:11354946

Marin, B J; Dodson, J J



Effect of Environmental Disturbance on the Population of Sandflies and Leishmania Transmission in an Endemic Area of Venezuela  

PubMed Central

The exploitation of new wilderness areas with crops is increasing and traditional crop substitution has been modified by new more productive crops. The results show the anthropogenic disturbance effect on the sandflies population and Leishmania transmission in endemic areas of Venezuela. Three agroecosystems with variable degrees of ecological disturbance, forest (conserved), cacao (fragmented), and orangery (disturbed), were selected. Four methods to sandfly capture were used; the specimens were identified and infected with Leishmania. Diversity, population structure, ANOVA, Tukey test, and simple correlation analysis were carried out. Shannon traps were able to capture 94.7% of the total sandflies, while CDC light traps, Sticky traps, and direct suction just captured 2.2%, 1.2%, and 0.9%, respectively. The results showed the effect of ecological disturbance degree on the composition of sandflies and population structure, revealing a dominance level increased but decreased on the diversity and richness of sandflies species in the greatest ecological disturbance area in relation to areas with less organic disturbance. Environments more disturbed cause adaptability of certain species such as Lutzomyia gomezi and Lutzomyia walkeri. These changes on the composition of sandflies population and structure emerging species could cause increasing of leishmaniasis transmission.

Nieves, Elsa; Oraa, Luzmary; Rondon, Yorfer; Sanchez, Mireya; Sanchez, Yetsenia; Rojas, Masyelly; Rondon, Maritza; Rujano, Maria; Gonzalez, Nestor; Cazorla, Dalmiro



Organic geochemical investigation and coal-bed methane characteristics of the Guasare coals (Paso Diablo mine, western Venezuela)  

USGS Publications Warehouse

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.

Quintero, K.; Martinez, M.; Hackley, P.; Marquez, G.; Garban, G.; Esteves, I.; Escobar, M.



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


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

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



Evaluation of the Seismic Hazard in Venezuela with a revised seismic catalog that seeks for harmonization along the country borders  

NASA Astrophysics Data System (ADS)

Probabilistic Seismic Hazard Assessment is a complex endeavor that relies on the quality of the information that comes from different sources: the seismic catalog, active faults parameters, strain rates, etc. Having this in mind, during the last several months, the FUNVISIS seismic hazard group has been working on a review and update of the local data base that form the basis for a reliable PSHA calculation. In particular, the seismic catalog, which provides the necessary information that allows the evaluation of the critical b-value, which controls how seismic occurrence distributes with magnitude, has received particular attention. The seismic catalog is the result of the effort of several generations of researchers along the years; therefore, the catalog necessarily suffers from the lack of consistency, homogeneity and completeness for all ranges of magnitude over any seismic study area. Merging the FUNVISIS instrumental catalog with the ones obtained from international agencies, we present the work that we have been doing to produce a consistent seismic catalog that covers Venezuela entirely, with seismic events starting from 1910 until 2012, and report the magnitude of completeness for the different periods. Also, we present preliminary results on the Seismic Hazard evaluation that takes into account such instrumental catalog, the historical catalog, updated known fault geometries and its correspondent parameters, and the new seismic sources that have been defined accordingly. Within the spirit of the Global Earthquake Model (GEM), all these efforts look for possible bridges with neighboring countries to establish consistent hazard maps across the borders.

Rendon, H.; Alvarado, L.; Paolini, M.; Olbrich, F.; González, J.; Ascanio, W.



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


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

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



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

USGS Publications Warehouse

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.

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



The relationship between mud volcanoes, petroleum migration and accretionary prisms: Lessons from the Caucasus, the Australian margin and Venezuela  

SciTech Connect

Mud volcanoes have been widely documented in areas of overpressure where explosive expansion of trapped methane has occurred during argillokinesis. In an area with high sedimentation rate, such as the Gulf of Mexico, there may be no time for fine-grained sediment to de-water before being covered by impermeable material. In an accretionary wedge this process is complicated by overthrusting of off-scraped material which increases the overburden pressure and provides many more avenues for the migration of fluids through the system. In some cases, such as is seen in the Caribbean, the fluids may escape directly to the surface (or seabottom) through high permeability beds. When this happens there may be no diapirism. In other cases, such as in Venezuela, the forearc may be the site of rapid, laterally-derived, sedimentation, and fluids from the overthrusted rocks may be forced to escape through several kilometers of recent deltaic sediments. Since these fluids may include petroleum, this has obvious exploration potential. If there are no suitable reservoir rocks, such as in Timor, there may be no commercial accumulations. However, many giant fields are associated, world-wide, with mud volcanoes, such as those in Azerbaijan.

Ware, P. [Unocal, Sugar Land, TX (United States)



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


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

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



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

USGS Publications Warehouse

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.

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



[Detection and differentiation of Entamoeba histolytica and Entamoeba dispar by polymerase chain reaction in a community in Zulia State, Venezuela].  


Differential identification of Entamoeba histolytica and Entamoeba dispar is essential for both appropriate patient treatment and epidemiological purposes. To determine the prevalence of these amoeba infections in Santa Rosa de Agua (Maracaibo, Zulia State, Venezuela), a PCR assay using specific primers for each species was standardized and applied. 204 stool samples were analyzed through direct microscopic examination with SSF (0.85%) and lugol, formol-ether concentration, and PCR. Under direct microscopy, 42 individuals (20.58%) presented the E. histolytica/E. dispar complex. Meanwhile PCR showed 47 positive cases for these amoebas: 22 E. histolytica (10.78%), 16 E. dispar (7.84%), and 9 (4.41%) mixed infections. There was no significant difference in the presence of E. histolytica and/or E. dispar according to either gender or age. There were no cases of these amoebas in children under 2 years of age. Observed frequency of E. histolytica (31/204) shows the endemic nature of amoeba infection in this community. PMID:19180297

Rivero, Zulbey; Bracho, Angela; Calchi, Marinella; Díaz, Iris; Acurero, Ellen; Maldonado, Adriana; Chourio, Glenis; Arráiz, Nailet; Corzo, Gilbert



[Risk markers in subjects with high loads of Ascaris lumbricoides in a rural community of the Cojedes State , Venezuela].  


A total of 337 individuals from a rural community of Venezuela (Mapurite, Estado Cojedes) was studied. Stoll faecal examination was carried out and the total number of A. lumbricoides was recovered after the treatment of the individuals sampled with Pyrantel pamoate at a dose of 10 mg/kg body weight in children and 15 mg/kg in adults. A relationship between the high worm burden condition (individuals excreting more than 10,000 epg of A. lumbricoides) and the age of the hosts was found. Resulting with the major values of relative risk index (Rr) the 5-9 years old class (Rr = 3.2 t = 3.4). This relationship was not found between high worm burden condition (HWB) and the sex of the hosts. The following individuals have the the highest possibilities to become HWB: with blood group A (Rr = 3.05 t = 4.08), with haemoglobin type HbA HbS (Rr = 1.86 t = 2.13), individuals with the combinations A HbA HbF (Rr = 3.46 t = 2.31) and A HbA HbS (Rr = 3.11 t = 2.78). It was estimated that the selective treatment of the total HWB detected (72) with an effective product, determined a reduction of 95.4% of the environmental contamination with de eggs and 72.3% of the worm burden. PMID:10883496

Morales, G; Loaiza, L; Pino, L A



Density estimates of the domestic vector of Chagas disease, Rhodnius prolixus Stål (Hemiptera: Reduviidae), in rural houses in Venezuela.  


We reported the use of the timed manual method, routinely employed as an indicator to the relative abundance of domestic triatomine bugs, to estimate their absolute density in houses. A team of six people collected Rhodnius prolixus Stål bugs from the walls and roofs of 14 typical palm-leaf rural houses located in Cojedes, Venezuela, spending 40 minutes searching in each house. One day after these manual collections, all the houses were demolished and the number of triatomine bugs were identified by instar and counted. Linear regression analyses of the number of R. prolixus collected over 4 man-hours and the census counts obtained by house demolition indicated that the fit of the data by instar (stage II--adult) and place of capture (roof versus palm walls versus mud walls) was satisfactory. The slopes of the regressions were interpreted as a measure of "catchability" (probability of capture). Catchability increased with developmental stage (ranging from 11.2% in stage II to 38.7% in adults), probably reflecting the increasing size and visibility of bugs as they evolved. The catchability on palm wall was higher than that for roofs or mud walls, increasing form 1.3% and 3.0% in stage II to 13.4% and 14.0% in adults, respectively. We reported, also, regression equations for converting field estimates of timed manual collections of R. prolixus into absolute density estimates. PMID:7614667

Rabinovich, J E; Gürtler, R E; Leal, J A; Feliciangeli, D



Domiciliary biting frequency and blood ingestion of the Chagas's disease vector Rhodnius prolixus Ståhl (Hemiptera: Reduviidae), in Venezuela.  


Demolition of a rural house in the State of Cojedes, Venezuela, provided a collection of 7.934 Rhodnius prolixus of which a random sample of 1,415 was weighed within 48 hours. The field weights, coupled with laboratory information of weight loss (in %) with time, average blood ingestion and meal size sufficient to promote moulting, were used to estimate biting rate under domiciliary conditions. The results show that in this particularly highly infested house, the R. prolixus population bites, on the average, at a rate of 58 times/person/day, draining blood at a rate of about 100 cm3/person/month; this meant a total of 1.2 litres/month from the 11 people inhabiting the house. It was found that the more advanced R. prolixus is in its development, the more aggressive it is in securing its meal: 15, 25, 30, 59 and 77% of fed insects of instar 1 through 5, respectively, were able to achieve moulting with only one meal. Applying the estimated biting rate to R. prolixus collections of other 13 demolished houses, with more typical insect population densities, an average biting rate of 9 bites/person/day was obtained; this value was, however, extremely variable, ranging from 0.2 bites/person/day (once every five days) to 33 bites/person/day. PMID:112731

Rabinovich, J E; Leal, J A; Feliciangeli de Piñero, D



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

NASA Astrophysics Data System (ADS)

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.

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



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

SciTech Connect

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.

James, K.H.; Rigby, S.M.



Reproductive biology of the violet-chested hummingbird in Venezuela and comparisons with other tropical and temperate hummingbirds  

USGS Publications Warehouse

We provide details on the breeding biology of the Violet-chested Hummingbird (Sternoclyta cyanopectus) based on 67 nests studied in Yacambu?? National Park, Venezuela, from 2002 through 2006. Clutch size was two white eggs, usually laid every other day. Fresh egg mass (0.95 ?? 0.14 g) was 15% of female mass. Incubation and nestling periods were 20.4 ?? 0.3 and 26.0 ?? 0.4 days, respectively. Nest attentiveness increased from 60% in early incubation to 68% in late incubation. The female spent 50% of her time brooding young nestlings, but ceased brooding by 13 days of age. Only the female fed the young, with a low rate of nest visitation (3.3 trips per hour) that did not increase with age of the young. Growth rate based on nestling mass (K = 0.28) was slow. Daily predation rates decreased across stages and were 0.064 ?? 0.044, 0.033 ?? 0.008, and 0.020 ?? 0.006 during the egg-laying, incubation, and nestling periods, respectively. Most, but not all, life history traits of the Violet-chested Hummingbird were similar to those reported for other tropical and temperate hummingbirds, providing further evidence that this family shows a relatively narrow range of life history variation. ?? The Cooper Ornithological Society 2007.

Fierro-Calderon, K.; Martin, T. E.



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


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

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



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


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

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



The Fused TrpEG from Streptomyces Venezuelae is an Anthranilate Synthase, Not a 2-Amino-2-deoxyisochorismate (ADIC) Synthase  

PubMed Central

The chloramphenicol producer Streptomyces venezuelae contains an enzyme, SvTrpEG, that has a high degree of amino acid sequence similarity to the phenazine biosynthetic enzyme PhzE of certain species of Pseudomonas. PhzE has the sequence signature of an anthranilate synthase, but recent evidence indicates that it catalyzes the production of 2-amino-2-deoxyisochorismate (ADIC), an intermediate in the two-step anthranilate synthase reaction, not anthranilate. In order to determine if SvTrpEG is likewise an ADIC synthase, we have cloned the gene for SvTrpEG, expressed the recombinant enzyme in Escherichia coli, and purified the enzyme. Analysis of the SvTrpEG-catalyzed reaction mixture using UV-visible spectrophotometry, fluorescence spectrometry, and high-performance liquid chromatography shows that the product of the reaction is anthranilate, not ADIC. Our results therefore reveal that, despite its sequence similarity to PhzE, SvTrpEG is an anthranilate synthase, not an ADIC synthase.

Ashenafi, Meseret; Carrington, Renee; Collins, Alvin C.; Byrnes, W. Malcolm



Organic petrology of Paleocene Marcelina Formation coals, Paso Diablo mine, western Venezuela: Tectonic controls on coal type  

USGS Publications Warehouse

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.

Hackley, P. C.; Martinez, M.



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

SciTech Connect

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.

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))



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

NASA Astrophysics Data System (ADS)

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

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



Late-life depression in Peru, Mexico and Venezuela: the 10/66 population-based study  

PubMed Central

Background The proportion of the global population aged 60 and over is increasing, more so in Latin America than any other region. Depression is common among elderly people and an important cause of disability worldwide. Aims To estimate the prevalence and correlates of late-life depression, associated disability and access to treatment in five locations in Latin America. Method A one-phase cross-sectional survey of 5886 people aged 65 and over from urban and rural locations in Peru and Mexico and an urban site in Venezuela. Depression was identified according to DSM–IV and ICD–10 criteria, Geriatric Mental State–Automated Geriatric Examination for Computer Assisted Taxonomy (GMS–AGECAT) algorithm and EURO–D cut-off point. Poisson regression was used to estimate the independent associations of sociodemographic characteristics, economic circumstances and health status with ICD–10 depression. Results For DSM–IV major depression overall prevalence varied between 1.3% and 2.8% by site, for ICD–10 depressive episode between 4.5% and 5.1%, for GMS–AGECAT depression between 30.0% and 35.9% and for EURO–D depression between 26.1% and 31.2%; therefore, there was a considerable prevalence of clinically significant depression beyond that identified by ICD–10 and DSM–IV diagnostic criteria. Most older people with depression had never received treatment. Limiting physical impairments and a past history of depression were the two most consistent correlates of the ICD–10 depressive episode. Conclusions The treatment gap poses a significant challenge for Latin American health systems, with their relatively weak primary care services and reliance on private specialists; local treatment trials could establish the cost-effectiveness of mental health investment in the government sector.

Guerra, Mariella; Ferri, Cleusa P.; Sosa, Ana Luisa; Salas, Aquiles; Gaona, Ciro; Gonzales, Victor; de la Torre, Gabriela Rojas; Prince, Martin



[Abundance of sea urchin Lytechinus variegatus (Lamarck) on North, East and West coasts of Margarita Island (Venezuela) ].  


The sea urchin roe reach a very high price in the international fish product market favoring the increase in the catches of this resource and overfishing in some countries. In the Island of Margarita (Venezuela) some species, Lytechinus variegatus (Lamarck) among others, are consumed as food but studies to determine abundance of the resource are unknown. Nine sample stations (depth less than 2 m) on the North, East and West coast of Margarita Island were visited in six different occasions between February/1998 and February/1999 to study the population density (urchins/m2) of L. variegatus. Using a quadrat (0.25 m2) thrown 8 times over seagrasses (Thalassia testudinum) beds and over submerged rocks and the urchins removed by dive. The diameter of each specimen was measured and returned to the sea. The water temperature, salinity and dissolved oxygen of each site was measured. Were collected a total of 2,073 urchins with a diameter ranging from 11.0 to 84.5 mm and population density between 1 to 52 urchins/m2. The mean size of specimens collected in the stations was between 30.44 and 55.09 mm and average density fluctuated between 3.2 to 43.2 urchins/m2. The station where sea urchins were found to be most abundant was the North coast (Manzanillo fishing villae) where they live on rocks with a density (38 a 52/m2) far over the values previously cited for the Caribbean sea and Florida. PMID:12216495

Gómez Gaspar, Alfredo



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

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



Prediction and verification of possible reef-fish spawning aggregation sites in Los Roques Archipelago National Park, Venezuela.  


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

Boomhower, J; Romero, M; Posada, J; Kobara, S; Heyman, W



[Some attributes of community structure of fishes in Laguna Grande de Obispo, Golfo Cariaco, Sucre State, Venezuela].  


Species composition, relative abundance, diversity and community structure of fishes were studied from monthly sampling during December 1995 to November 1996 in the Laguna Grande de Obispo, Gulf of Cariaco, Sucre State, Venezuela. Sampling were realised in 3 stations inside the lagoon with a small beach seine and the other 4 stations with a large beach seine. Seventy four species belonging to 33 families and 68 genera were identified of which 8 species dominated, constituting 90.43% of total catch. Mugil curema, Xenomelaniris brasiliensis, Opistonema oglinum, Atherinomorus stipes and Anchoa hepsetus were present in high abundance in the biomass. M. curema dominated the catch with large seine while X. brasiliensis, M. curema and Eucinostomus argenteus dominated the catch with small seine. Species diversity (H') ranged from 2.968-4.607 bits/ind and species richness of Margalef from 2.752-7.464. An inverse analysis realized on catches by small seine and based on nodal constancy and fidelity allowed to define a pattern of spatial distribution of 9 groups containing 1 to 11 species on the basis their abundance, frequency of appearance and ecological characteristics of each area. An analysis of correlation showed that the salinity, dissolved O2 and precipitation did not show any significant correlation with the ecological parameters studied but existed significant correlation with average surface water temperature (p < 0.05), number of species (S), individuals (N), diversity (H') and species richness (D). The positive correlation was found with surface temperature but no relationship with relative dominance (D1 and D2). The CPUE in biomass did not show any significant association with temperature. PMID:11510425

De Grado, A A; Bashirullah, A



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

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.



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


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

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



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

NASA Astrophysics Data System (ADS)

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.

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



Geomorphological signature of the Pleistocene thin-skinned tectonics in the northern Maturín Foreland Basin, Eastern Venezuela  

NASA Astrophysics Data System (ADS)

The Eastern Venezuela foreland basin and the Serranía del Interior fold-thrust-belt were formed as a consequence of the oblique collision between Caribbean and South American plates. The foreland basin is divided into the Guárico sub-basin in the west and the Maturín sub-basin in the east. The Maturín sub-basin is geologically well known due to geological survey and structural-stratigraphic modeling motived by the hydrocarbon exploration. We focus here on Plio-Pleistocene deformations of the area that remain poorly understood. The study area stands on the northern edge of the Maturín sub-basin, in an area limited by the foothills of the Serranía del Interior to the north, and by the right lateral crustal Urica and San Francisco Faults to the west and east respectively. Between them, from the mountain to the deformation front, the thin-skinned tectonic wedge is mainly structured above the Pirital and Furrial thrust faults. The Pirital thrust fault involves a thick lithographic section that includes presumably pre-Cretaceous rocks whereas the Furrial Thrust is shallower and is associated with fault-bend-folds structures. We support that the Maturín sub-basin remains an area of active continental shortening in which a post-Pliocene peneplain surface has been deformed by folds, which are developed above buried reverse faults. We use the drainage patterns in this region to show active deformations that would be difficult to identify by other means. In particular we show how uplifts and tilts associated to fault activity alter the drainage pattern and the geometry of remnant terraces near Tarragona, San Felix, Punta de Mata, El Tejero and Jusepín zones. Given age, dip angles of the faults, and the vertical throw determined from the offset of the terrace and peneplain surfaces across the surface fault traces, we aim to estimate the cumulative shortening along the direction of tectonic transport and slip rates. Industrial seismic lines show that superficial deformations are not systematically connected to fault in depth. This raise the question (1) of the origin of the ongoing shortening in the tectonic wedge and (2) of the potentiality of a strain partitioning between thick-skinned and thin-skinned active deformations.

Fajardo, Atiria; Nivière, Bertrand; Aubourg, Charles; Hervouët, Yves; Wagner, Roberto; Regard, Vincent; Callot, Jean-Paul



Refuerzo de la Vivienda Economica en Zonas Sismicas: Estudios Experimentales (Strengthening of Low Houses in Seismic Areas: Experimental Studies).  

National Technical Information Service (NTIS)

In order to evaluate the efficiency of several strengthening methods for adobe houses, nine 1:2.5 scale models were tested in a shaking table under the effect of the accelerograms of three major actual earthquakes; mechanical properties of adobe masonry a...

O. Hernandez R. Meli M. Padilla E. Valencia



Venezuela: Lake Maracaibo  

... Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image credit: NASA/GSFC/LaRC/JPL, MISR Team. Text ... (Acro Service Corporation/Jet Propulsion Laboratory), David J. Diner (Jet Propulsion Laboratory), John V. Martonchik (Jet Propulsion ...



Major and trace elements in river-borne materials from the Cuyuni basin (southern Venezuela): evidence for organo-colloidal control on the dissolved load and element redistribution between the suspended and dissolved load  

Microsoft Academic Search

The Cuyuni basin is a metallogenic-rich area located in southern Venezuela in the Precambrian Guyana shield. It comprises two geologically distinct zones, one with granite domes and intercalated greenstone belts in the northern and western part of the basin and the other with stratified arenaceous deposits in the south. The suspended, dissolved and total load of the rivers draining these

T. Tosiani; M. Loubet; J. Viers; M. Valladon; J. Tapia; S. Marrero; C. Yanes; A. Ramirez; B. Dupre



Comparative amino acid sequence analysis of the major outer capsid protein (VP7) of porcine rotaviruses with G3 and G5 serotype specificities isolated in Venezuela and Argentina  

Microsoft Academic Search

Summary Seven porcine group A rotavirus strains isolated in Venezuela were shown to be antigenically related to serotype G3 (five strains) or to serotype G5 (two strains), whereas two strains isolated in Argentina were classified as serotype G5. The serological classification of eight of these strains was confirmed by sequence analysis of the gene encoding the VP7 glycoprotein. A high

M. Ciarlet; J. E. Ludert; F. Liprandi



Earthquake source imaging by high-resolution array analysis at regional distances: the 2010 M7 Haiti earthquake as seen by the Venezuela National Seismic Network  

NASA Astrophysics Data System (ADS)

Back projection of teleseismic waves based on array processing has become a popular technique for earthquake source imaging,in particular to track the areas of the source that generate the strongest high frequency radiation. The technique has been previously applied to study the rupture process of the Sumatra earthquake and the supershear rupture of the Kunlun earthquakes. Here we attempt to image the Haiti earthquake using the data recorded by Venezuela National Seismic Network (VNSN). The network is composed of 22 broad-band stations with an East-West oriented geometry, and is located approximately 10 degrees away from Haiti in the perpendicular direction to the Enriquillo fault strike. This is the first opportunity to exploit the privileged position of the VNSN to study large earthquake ruptures in the Caribbean region. This is also a great opportunity to explore the back projection scheme of the crustal Pn phase at regional distances,which provides unique complementary insights to the teleseismic source inversions. The challenge in the analysis of the 2010 M7.0 Haiti earthquake is its very compact source region, possibly shorter than 30km, which is below the resolution limit of standard back projection techniques based on beamforming. Results of back projection analysis using the teleseismic USarray data reveal little details of the rupture process. To overcome the classical resolution limit we explored the Multiple Signal Classification method (MUSIC), a high-resolution array processing technique based on the signal-noise orthognality in the eigen space of the data covariance, which achieves both enhanced resolution and better ability to resolve closely spaced sources. We experiment with various synthetic earthquake scenarios to test the resolution. We find that MUSIC provides at least 3 times higher resolution than beamforming. We also study the inherent bias due to the interferences of coherent Green’s functions, which leads to a potential quantification of biased uncertainty of the back projection. Preliminary results from the Venezuela data set shows an East to West rupture propagation along the fault with sub-Rayleigh rupture speed, consistent with a compact source with two significant asperities which are confirmed by source time function obtained from Green’s function deconvolution and other source inversion results. These efforts could lead the Venezuela National Seismic Network to play a prominent role in the timely characterization of the rupture process of large earthquakes in the Caribbean, including the future ruptures along the yet unbroken segments of the Enriquillo fault system.

Meng, L.; Ampuero, J. P.; Rendon, H.



Seasonal variability in multi-elemental ratios and ?18O in planktonic foraminifera from the Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Multi-elemental ratios (Mg/Ca, Mg/Li, Li/Ca, B/Ca, U/Ca, P/Ca, Cd/Ca, and Zn/Ca) of four planktonic foraminiferal species (Globigerinoides ruber, Globigerinoides sacculifer, Orbulina universa, and Globorotalia menardii) have been measure on a Thermo Element 2 inductively coupled plasma mass spectrometer (ICP-MS) and ?18O measurements have been taken on a GV ISOPRIME stable isotope ratio mass spectrometer. The material is from biweekly sediment trap samples collected in the Cariaco Basin, Venezuela (10o30’ N, 65o31’ W) between May 2003 and May 2004. The data are compared to local hydrography and water column chemistry to evaluate each proxy’s applicability in reconstructing past ocean conditions. The oxygen isotope results are consistent with known depth habitats for all five species. The surface dwelling G. ruber displays the lowest values of -0.84 and -1.76‰. G. sacculifer which lives in the upper 50m, displays slightly higher ?18O (-0.55 - -1.39‰) and the deeper dwelling O. universa and G. menardii have the highest ?18O, predominately ranging from 0.0 to -1.0‰. The G. ruber ?18O range equates to a temperature range of approximately 4.5 oC, which is equivalent to seasonal SST range (24.5-29 oC). Temperature estimates derived from species specific equations indicate that G. ruber most accurately tracks SST throughout the year. The temperature proxies, Mg/Ca (mmol/mol) and Mg/Li (mol/mmol), also reflect these different depth habitats (G. ruber: 4.1 - 6.9, 0.3 - 0.5; G. sacculifer: 2.9 - 4.3, 0.2 - 0.4; G. menardii: 1.9 - 4.3, 0.1 - 0.3) except that O. universa has a relatively high concentration of magnesium (7.1 - 13.1, 0.8 - 1.6). With these proxies, G. sacculifer most accurately reflects SST for both Mg/Ca and Mg/Li. For Li/Ca (µmol/mol) G. ruber has the highest ratios (13.2 - 18.5) and O. universa has the lowest (7.1 - 11.6). All of the species show an inverse relationship between temperature and Li/Ca with G. ruber most accurately recording SST. The pH proxy, B/Ca (µmol/mol), displays clear depth stratification with G. ruber having the highest B/Ca (246 - 360) and G. menardii and O. universa the lowest (102 - 230), consistent with a decrease in pH with depth. However, the other pH proxy, U/Ca shows no inter-species variation with all species having U/Ca values between 8 and 27 nmol/mol, which suggests that U incorporation is controlled by additional factors. All of the species display higher average values of the nutrient proxies P/Ca (mmol/mol), Cd/Ca (µmol/mol), and Zn/Ca (µmol/mol) during the winter upwelling than during non-upwelling, which is consistent with the nutrient distributions in the water column. None of the proxies show a significant relationship with measured phosphate concentrations; however this may be a result of uniformly low phosphate concentrations in the mixed layer.

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



Reproductive phenology of 233 species from four herbaceous-shrubby communities in the Gran Sabana Plateau of Venezuela  

PubMed Central

Background and aims Herbaceous–shrubby communities in the Gran Sabana (Great Savanna) Plateau of Venezuela grow under non-zonal conditions. We speculated that this would produce specific patterns of reproductive phenology within these different soil–climate–vegetation associations. Specifically, we tested the hypothesis that the reproductive phenology patterns of four herbaceous–shrubby communities are determined by climate, plant life-forms and soil properties. Methodology The reproductive phenology of 233 plant species of the Gran Sabana Plateau of the Venezuelan Guayana Highlands was studied taking into account their life-forms (i.e. trees, shrubs, climbers, annual herbs, perennial herbs, epiphytes and parasites/hemiparasites) in four herbaceous–shrubby communities: (i) shrubland, (ii) secondary bush, (iii) savanna and (iv) broad-leaved meadow. Patterns of flowering, and occurrence of unripe fruit and ripe fruit were studied at two levels of intensity for 24 months within a 5-year span. Two phenological records for each month of the year and between two and four replicates for each community type were made. Randomly selected 2–3 ha plots were used. General phenological patterns were established using <25% of the plants of each species in each plot to give the total duration of each phenological phase. High-intensity phenological patterns were established using >25% of individuals in each plot to establish times of high abundance of flowers, and presence of unripe fruit and/or ripe fruit on individual plants. This generated phenological peaks for each species. Principal results Non-seasonality of general flowering and unripe fruiting in each of the four communities was related to non-seasonal flowering and unripe fruiting patterns in the plant life-forms studied and to low variation in precipitation throughout the year. Flowering activity in the shrubland and broad-leaved meadow peaked twice. The bush community had only one flowering peak while the savanna gave a non-seasonal flowering peak. The peak unripe fruiting pattern was not clearly related to unripe fruit phenological patterns of the most abundant life-forms. Unripe fruit patterns and precipitation were only correlated for shrubs, climbers and trees in the shrubland. Ripe fruiting patterns peaked during the short-dry season in the bush and shrubland, and were negatively correlated with precipitation in the shrubland. General and peak ripe fruiting patterns were non-seasonal in the savanna and broad-leaved meadow and related to the dominance of herbaceous species with prolonged ripe fruiting times, low climate seasonality, high plant species richness and diversity, and dispersal syndromes. Conclusions The reproductive phenology of the herbaceous–shrubby communities is mainly influenced by the composition of the life-forms, the precipitation regime and soil type.

Ramirez, Nelson; Briceno, Herbert



Complete genome sequence of Jacquemontia yellow mosaic virus, a novel begomovirus from Venezuela related to other New World bipartite begomoviruses infecting Convolvulaceae.  


The complete genome of a bipartite begomovirus (genus Begomovirus, family Geminiviridae) infecting Jacquemontia sp. (Convolvulaceae) in Venezuela has been cloned and sequenced. Sequence comparison and phylogenetic analysis have shown that it represents an isolate of a novel species with closest relatives being two New World bipartite begomoviruses that infect Convolvulaceae, Jacquemontia mosaic Yucatan virus and Merremia mosaic virus. The DNA-As of these begomoviruses, however, share only 77.0-78.4 % nucleotide sequence identity with the DNA-A of the isolate described here, for which a recombinant origin is suggested. Based on the symptoms observed in the field, the name Jacquemontia yellow mosaic virus (JacYMV) is proposed for this novel bipartite begomovirus. PMID:24463954

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



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

PubMed Central

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

Caballer, Manuel; Ortea, Jesus; Narciso, Samuel



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

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.

Chacon, Jose



[Prevalence of beta-lactamase CTX-M-15 in phylogenetic groups of uropathogenic Escherichia coli isolated from patients in the community of Merida, Venezuela].  


In this study we determined the prevalence of extended-spectrum beta-lactamases (ESBLs) in phylogenetic groups of uropathogenic E. coli (UPEC) isolated from patients in the community. Twenty one UPEC strains with reduced susceptibility to broad-spectrum cephalosporins were collected between January 2009 and July 2010, from patients with urinary tract infection who attended the Public Health Laboratory in Mérida, Venezuela. Genotypic characterization determined that all UPEC strains harbored blaBLEEs genes: 76.2% of the strains showed the presence of a single ESBL-producer gene, represented by blaCTX-M-15, whereas 23.8% of UPEC showed various combinations of bla genes (blacCTX-M-15 + blaTEM-1, blaCTX-M-15 + blaSHV and blaSHV + blaTEM-1). In this study, 61.9% of the isolates were placed in phylogroup A and the remaining strains were assigned to group B2 (38.1%). There was no evidence of spread of a particular UPEC clone; only seven strains belonged to a clonal group with an index of similarity greater than 85%. To our knowledge, this is the first description of blxCTX-M-15 in UPEC from patients with community-acquired urinary tract infections, which shows that Venezuela is also part of the so-called CTX-M-15 pandemic. The findings in this study, as well as its clinical and epidemiological implications, lead to the need for monitoring and controlling the spread of CTX-M-15 producing UPECs, not only regionally, but also nationwide. PMID:24758100

Hernández, Erick; Araque, María; Millán, Ysheth; Millán, Beatriz; Vielma, Silvana



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)

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.

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



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

NASA Astrophysics Data System (ADS)

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

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



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.  


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

Chacón, Jose



Sedimentary evolution of the upper Cretaceous and late Oligocene sequences, and its relation to oil production, North Monagas area, Eastern Venezuela  

SciTech Connect

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.

Sambrano, J.; Rojas, B.; Rendon, J.; Chigne, R. [Corpoven, S.A., La Cruz (Venezuela); Maguregui, J. [Intevep, Los Teques (Venezuela)



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


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

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



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


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

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



[Detection of Entamoeba histolytica and Entamoeba dispar by PCR in children, less than five years of age with diarrhea, in Maracaibo, Venezuela. A preliminary study].  


To determine the prevalence of Entamoeba histolytica as a producer of diarrhea, a study was conducted in children, less than five years of age, with diarrhea who attended several out patient clinics of the Servicio Aut6nomo Hospital Universitario, Maracaibo, Venezuela. A macroscopic and microscopic examination with physiological saline, lugol and Kinyoun staining were performed to the stool samples obtained. The remainder of the sample was frozen until DNA extraction, and PCR amplification was performed separately for E. histolytica and E. dispar. Microscopic examination showed no trophozoites and/or cysts of Entamoeba histolytica/dispar/moshkovskii, or intestinal coccidians in any of the 50 samples analyzed. Parasites detected were Giardia lamblia (6%), Blastocystis sp. (4%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) and Trichuris trichiura (2%). By PCR, six samples (12%) had DNA of E. dispar and two (4%) had DNA from E. histolytica; no child showed association of both amoebae. The two children who had E. histolytica were one-year-old. E. dispar was detected in younger children. We suggest that the prevalence of E. histolytica in children under five years is really low. PMID:24502179

Bracho Mora, Angela; Rivero de Rodríguez, Zulbey; Arraiz, Nailet; Villalobos, Rafael; Urdaneta, Haydee



Density estimates of the domestic vector of Chagas disease, Rhodnius prolixus St?l (Hemiptera: Reduviidae), in rural houses in Venezuela.  

PubMed Central

We reported the use of the timed manual method, routinely employed as an indicator to the relative abundance of domestic triatomine bugs, to estimate their absolute density in houses. A team of six people collected Rhodnius prolixus Stål bugs from the walls and roofs of 14 typical palm-leaf rural houses located in Cojedes, Venezuela, spending 40 minutes searching in each house. One day after these manual collections, all the houses were demolished and the number of triatomine bugs were identified by instar and counted. Linear regression analyses of the number of R. prolixus collected over 4 man-hours and the census counts obtained by house demolition indicated that the fit of the data by instar (stage II--adult) and place of capture (roof versus palm walls versus mud walls) was satisfactory. The slopes of the regressions were interpreted as a measure of "catchability" (probability of capture). Catchability increased with developmental stage (ranging from 11.2% in stage II to 38.7% in adults), probably reflecting the increasing size and visibility of bugs as they evolved. The catchability on palm wall was higher than that for roofs or mud walls, increasing form 1.3% and 3.0% in stage II to 13.4% and 14.0% in adults, respectively. We reported, also, regression equations for converting field estimates of timed manual collections of R. prolixus into absolute density estimates. Images Fig. 1

Rabinovich, J. E.; Gurtler, R. E.; Leal, J. A.; Feliciangeli, D.



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


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

Sletto, Bjørn; Rodriguez, Iokiñe



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

PubMed Central

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

Gonzalez, Fanny



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)

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.

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



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

NASA Astrophysics Data System (ADS)

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

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



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

SciTech Connect

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

Burgie, E. Sethe; Holden, Hazel M. (UW)



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


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

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



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

NASA Astrophysics Data System (ADS)

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

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


Trends of violence among 7th, 8th and 9th grade students in the state of Lara, Venezuela: The Global School Health Survey 2004 and 2008  

PubMed Central

Background Violence by young people is one of the most visible forms of violence and contributes greatly to the global burden of premature death, injury and disability. Methods The Global School-based Student Health Survey (GSHS), State of Lara, Venezuela (GSHS-Lara) is a school-based surveillance system. It comprises a repeated, cross-sectional, self-administered survey drawn from a representative sample of 7th to 9th grade students, performed in the school years 2003-2004 (GSHS-Lara 2004) and 2007-2008 (GSHS-Lara 2008). It explores, among other things, a general violence indicator such as school absenteeism due to feeling unsafe at school or on the way to or from school for any reason; and more specific indicators of violence such as robbery, bullying, physical fights and use of weapons, as well as exposure to lectures on how to prevent violence. Results are given in terms of prevalence percentage. Results Absenteeism doubled between the two study periods (10.8% to 20.8%). The number of students that were a victim of robbery remained high and without change both outside (14.2% and 14.8%) and inside school (21.7% and 22.0%). The number of victims of bullying was high and increasing (33.4% and 43.6%). Bullying associated with being physically attacked decreased (18.5% to 14.3%). Physical attacks without active participation and not associated with bullying were frequent (21.5%). Physical fighting with active participation prevalence remained high and without change (27.5% and 28.2%). Carrying a weapon almost doubled (4.3% to 7.1%). Less than 65% reported classes for violence prevention. Conclusions The GSHS-Lara shows that violence is an important public health problem that needs to be addressed by the community and its authorities.



New Vanadium Compounds in Venezuela Heavy Crude Oil Detected by Positive-ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.  


Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of CnH2n-40N4V1O1 (36 ? n ? 58),CnH2n-42N4V1O1 (37 ? n ? 57),CnH2n-44N4V1O1 (38 ? n ? 59),CnH2n-46N4V1O1 (43 ? n ? 54),CnH2n-48N4V1O1 (45 ? n ? 55),CnH2n-38N4V1S1O1 (36 ? n ? 41),CnH2n-40N4V1S1O1 (35 ? n ? 51),CnH2n-42N4V1S1O1 (36 ? n ? 54),CnH2n-44N4V1S1O1 (41 ? n ? 55),CnH2n-46N4V1S1O1 (39 ? n ? 55),CnH2n-27N5V1O1 (29 ? n ? 40),CnH2n-29N5V1O1 (34 ? n ? 42),CnH2n-33N5V1O1 (31 ? n ? 38),CnH2n-35N5V1O1 (32 ? n ? 41),CnH2n-27N5V1O2 (32 ? n ? 41) and CnH2n-29N5V1O2 (33 ? n ? 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils. PMID:24948028

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



New Vanadium Compounds in Venezuela Heavy Crude Oil Detected by Positive-ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

PubMed Central

Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of CnH2n-40N4V1O1 (36 ? n ? 58),CnH2n-42N4V1O1 (37 ? n ? 57),CnH2n-44N4V1O1 (38 ? n ? 59),CnH2n-46N4V1O1 (43 ? n ? 54),CnH2n-48N4V1O1 (45 ? n ? 55),CnH2n-38N4V1S1O1 (36 ? n ? 41),CnH2n-40N4V1S1O1 (35 ? n ? 51),CnH2n-42N4V1S1O1 (36 ? n ? 54),CnH2n-44N4V1S1O1 (41 ? n ? 55),CnH2n-46N4V1S1O1 (39 ? n ? 55),CnH2n-27N5V1O1 (29 ? n ? 40),CnH2n-29N5V1O1 (34 ? n ? 42),CnH2n-33N5V1O1 (31 ? n ? 38),CnH2n-35N5V1O1 (32 ? n ? 41),CnH2n-27N5V1O2 (32 ? n ? 41) and CnH2n-29N5V1O2 (33 ? n ? 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils.

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



Corpus luteum activity, fertility, and adrenal cortex response in lactating Carora cows during rainy and dry seasons in the tropics of Venezuela.  


The effect of the rainy (RS) and the dry season (DS) on fertility, corpus luteum activity, and adrenal cortex response relationships were evaluated after first service (49 +/- 6 d postpartum) in Carora cows, a dairy cattle of Venezuela raised in tropical conditions. Cows (n = 84 in RS and n = 98 in DS) were kept semistabled, had two or three calvings, body condition score 3.5 on a 5-point scale and similar milk yield (2450 +/- 560 kg of milk during the previous lactation). Cows were grouped retrospectively according to pregnancy status. A split-plot model with repeated measures over Days 5, 7, 10, 14, and 15 after insemination was used to analyze the effects of season, pregnancy status, and their interaction involving the day on: 1) serum concentration of progesterone in four treatments: RS pregnant (n = 26), RS nonpregnant (n = 24), DS pregnant (n = 24), and DS nonpregnant (n = 20) cows; 2) serum concentration of cortisol at Days 0, 10, 14, 15, and 16 postservice in the previous treatments (n = 9, 7, 6, and 8, respectively); and 3) concentrations of cortisol after 0.1 mg of adrenocorticotropin in these last four groups of cows at Day 14 postinsemination. Breeding during the DS decreased (P < 0.05) conception rate to first service and increased (P < 0.01) days in service. In addition, the DS decreased (P < 0.05) the percentages of cows with normal interestrous interval (20-22 d), expression of estrus, and (P < 0.01) luteal phase progesterone; but DS increased (P < 0.05) percentages of short and long estrous cycles, anovulatory estrus, and repeat breeding rate. Mean serum concentration of progesterone was lower (P < 0.05) at Days 10, 14, and 15 in DS nonpregnant than in DS pregnant cows, and lower during luteal phase (P < 0.05) in DS nonpregnant than RS nonpregnant cows. Serum cortisol concentration was greater (P < 0.05) at Days 10, 14, and 16 in DS nonpregnant than DS pregnant cows. A significant (P < 0.05) negative correlation (r = -0.78) between serum concentrations of progesterone and cortisol was found within DS nonpregnant cows. Concentrations of cortisol after adrenocorticotropin were greater (P < 0.05) in DS nonpregnant cows than in other groups. These results indicate that elevated concentrations of cortisol associated with the DS may decrease progesterone secreted by the corpus luteum and therefore mediate the negative effect of the DS on fertility. PMID:8839624

Leyva-Ocariz, H; Querales, G; Saavedra, J; Hernández, A



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)

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.

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



Aluminum Smelter (Venezuela). Feasibility Study.  

National Technical Information Service (NTIS)

The document presents the findings of a study conducted for Aleaciones Ligeras ALISA S.A. The study assessed the feasibility of building an aluminum smelter, utilizing AP-30 technology, to supply the Asian markets with 25 Kg ingots. The report of the stud...



Meiofauna of the Venezuela Basin.  

National Technical Information Service (NTIS)

Study efforts were focused on quantitative determinations of meiofauna (herein defined as benthic metazoans that pass through a sieve with a mesh opening of 0.500 mm and which are retained on a sieve with a mesh opening of 0.044 mm) that occur in three di...

J. H. Tietjen



Biology Curriculum Reform in Venezuela.  

ERIC Educational Resources Information Center

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)

Rondon, Leonor Mariasole



Modellazione del legame costitutivo di isolatori in gomma armata e studio delle conseguenze sulla risposta sismica di strutture isolate. (Reinforced rubber bearing behaviour modeling; isolated structure seismic response).  

National Technical Information Service (NTIS)

In this analysis of simplified constitutive models suitable for the simulation of high damping rubber bearings (for use in nuclear and industrial plants), the well-known equivalent elastic and bilinear models are compared with the Davidenkov-Martin model ...

T. Sano' G. Di Pasquale



The diffuse seismicity of the Sierra Nevada of Santa Marta, the Perijá Range, and south of the La Guajira peninsula, Colombia and Venezuela: Result of the convergence between Caribbean plate and the South American margin during the Late Neogene?  

NASA Astrophysics Data System (ADS)

A diffuse low deep microseismicity located overall between the Guajira peninsula and the Sierra Nevada de Santa Marta (SNSM) was registered with the recent installation (2008 to Present) of three seismological stations in northeastern Colombia by the Colombian Seismological Network (RSNC), but mainly with the Uribia station in (the) central region of La Guajira peninsula, The microseismicity is characterized by a great population of events with 1.2 < Ml < 3.0. and few events of 3.0 < Ml < 4.0 that sporadically occur. The poor number of seismological stations in this region of Colombia impedes to locate the origin of the local seismicity; however, this seismic activity is associated to the tectonic activity of the Oca fault because with the GPS displacement analysis, neotectonics evidence found in faults traces associated to the Oca fault and the historical earthquake that affected the Colombian city of Santa Marta in 1834, lead us to conclude this. This is a big cortical fault that sets the limit between La Guajira peninsula and the SNSM. Its cortical characteristics were verified from geological data together with gravimetric and seismic exploration. The SNSM limits toward the southeast with the Cesar - Ranchería basin, and this basin in turn limits with the Perijá Range that is localized in the Colombia - Venezuela border. The SNSM, Cesar - Ranchería basin and Perijá Range limit toward the southwest with the Bucaramanga - Santa Marta fault (BSMF), the Oca fault toward the north, and Perijá - El Tigre fault toward the southeast defining a pyramidal orogenic complex. Using remote sensing images data with geological and regional geophysical information, we proposed that this orogenic complex was originated as a result of the Panama arc with the northwestern South America accretion. The final adjustment of the Caribbean plate (CP) between North America and South America during the Late Neogene produced the big cortical faults systems activation like Oca - Moron - El Pilar in Colombia and Venezuela toward the south of the Caribbean Plate (CP), and Motegua - Walton - Enriquillo - Plantain Garden toward the north of the CP. This situation was originated of a new subduction development of the Nazca - Cocos plates toward the south and the west of the Panama arc; when this happened, the evolution of the Present - day configuration of the Nazca plate and Galapagos Spreading Center started. From the Early Pliocene, the BSMF and the Oca fault were reactivated: the BSMF, with a left lateral movement, and the Oca fault with a right lateral movement. This last mobility produces the cortical diffuse seismicity that we are showing here.

Chicangana, G.; Pedraza, P.; Mora-paez, H.; Ordonez Aristizabal, C. O.; Vargas-Jimenez, C. A.; Kammer, A.



Seasonal and nocturnal domiciliary human landing/biting behaviour of Lutzomyia (Lutzomyia) evansi and Lutzomyia (Psychodopygus) panamensis (Diptera; Psychodidae) in a periurban area of a city on the Caribbean coast of eastern Venezuela (Barcelona; Anzoátegui State).  


In recent years, in addition to American cutaneous leishmaniasis (ACL), a significant number of cases of American visceral leishmaniasis (AVL) have been reported in periurban areas of Barcelona city (Anzoátegui State, Venezuela). We studied the bionomics of Lutzomyia (Lutzomyia) evansi and Lutzomyia (Psychodopygus) panamensis, possible vectors of AVL and ACL, respectively, in El Rincón, a periurban village of that city. To evaluate the seasonal domiciliary landing/biting activity of sandflies on human bait, a house was chosen in El Rincón. Landing catches were carried out between 18:00 and 06:00, once a month for a year. The results show the presence of 2 species, Lu. (Lu.) evansi (89.9%) and Lu. (Psy.) panamensis (10.1%). Lu. evansi was most abundant in the months of October and July, associated with the bimodal cycle of annual rainfall in the area. Maximum landing/biting activity of Lu. evansi was observed at 24:00 and 03:00. These findings suggest that at this time of the year and at these hours there is heightened risk of the transmission of AVL. Lu. panamensis monthly abundance also shows a direct association with rainfall and maximum landing/biting activity was observed between 02:00 and 03:00. The lower domiciliary abundance of Lu. panamensis suggests its greater importance in the extradomiciliary transmission of ACL. PMID:10674076

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



Interpretacion de Fotografias Aereas para la Clasificacion y Elaboracion de Cartas Geograficas del Suelo (Interpretation of Photographs for the Classification and Production of Geographic Soil Maps).  

National Technical Information Service (NTIS)

Since 1929, aerial photography has been a boon to soil mapping, both as a check on field studies, and as a temporary and partial substitute for them when necessary. When the latter situation is the case, the proper photographs and interpretation of them i...



Snubdrilling a new well in Venezuela  

SciTech Connect

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.

Aasen, J.



Cryptococcus neoformans, Cryptococcus gattii: serotypes in Venezuela.  


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

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



Industry Sector Analysis - Business Equipment, (Venezuela).  

National Technical Information Service (NTIS)

The Industry Sector Analyses (I.S.A) for business equipment contains statistical and narrative information on projected market demand, end-users, receptivity of Venezuelan consumers to U.S. products, the competitive situation - Venezuelan production, tota...



Sub-Program Vulcanismo: Interpretacion Vulcanologica de la Parte Seprentrional de la Cordillera Occidental de Bolivia, Utilizando Imagenes ERTS. (Volcanism Subprogram: Volcanological Interpretation of the Northern Part of the Occidental Cordillera of Boliva, Utilizing ERTS Imagery).  

National Technical Information Service (NTIS)

The author has identified the following significant results. In the present study, 6 ERTS-1 images have been interpreted on a 1:1 million scale (black and white) with the respective field reconnaissance. The area studied is located in the region bordering...

C. E. Brockmann S. Kussmaul



La Migracion Como Una Transicion Critica para la Persona en Su Ambiente. Una Interpretacion Organismico Evolutiva. (Migration as a Critical Person-in-Environment Transition: An Organismic-Developmental Interpretation.)  

ERIC Educational Resources Information Center

In order to explore some of the changes and stresses connected with migration and return migration, a study was conducted among migrants returning from the United States mainland to Puerto Rico. The sample consisted of 75 adolescents participating in a Bilingual Education program in Puerto Rico. Data were collected using Psychological Distance…

Pacheco, Angel M.; And Others


Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela  

Microsoft Academic Search

Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation

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



Mass Schooling for Socialist Transformation in Cuba and Venezuela  

ERIC Educational Resources Information Center

In contemporary contexts of Education for All and emphases on national educational performance, mass education globally continues to be strongly informed by human capital thinking, and by notions of developing future world citizens and workers for the international economy. In this paper, our central focus is on the ongoing educational project of…

Griffiths, Tom G.; Williams, Jo



Characteristics of Tropical Squall-Lines Over Venezuela.  

National Technical Information Service (NTIS)

The characteristics of fifteen mesoscale storm systems observed during the 1972 Venezuelan International Meteorological and Hydrological Experiment were compared with the predictions of a dynamic cumulonimbus and squall-line model proposed by Moncrieff (1...

R. W. Grover



Industry Subsector Analysis, Venezuela: Plastic Machinery and Equipment.  

National Technical Information Service (NTIS)

Machinery imports by the Venezuelan plastics industry, although reduced compared to previous years, appear to have stabilized and to be making a modest comeback. Since the market opened to imports of finished plastic products in 1989, the industry has bee...

E. P. Simai



Studies in neotropical polypores 10. New polypores from Venezuela.  


Antrodiella dentipora, Ceriporia albobrunnea, C. cystidiata, Diplomitoporus allantosporus, D. stramineus, D. venezuelicus, Flabellophora fasciculata, Navisporus perennis, Nigroporus macroporus, Polyporus albostipes, Rigidoporus aurantiacus, Skeletocutis microcarpa, Tinctoporellus isabellinus, Trametes olivaceopora, T. supermodesta, Trichaptum variabilis, Tyromyces neostrigosus, T. polyporoides and Wrightoporia roseocontexta are described as new. Keys to all, except Trametes, the new neotropical species in their respective genera are included. The combinations Trichaptum griseofuscens (Mont.) Ryvarden & Iturriaga, and Tyromyces americanus (D. Reid) Ryvarden & Iturriaga are proposed. PMID:21149014

Ryvarden, Leif; Iturriaga, Teresa



78 FR 55096 - Ferrosilicon from Russia and Venezuela  

Federal Register 2010, 2011, 2012, 2013

...Background On July 19, 2013, a petition was filed with the Commission and Commerce by Globe Specialty Metals, Inc. (``GSM''), New York, New York; CC Metals and Alloys, LLC (``CCMA''), Calvert City, Kentucky; the United Steel,...



Peasants in primitive accumulation: Western Europe and Venezuela compared  

Microsoft Academic Search

The basic point of this comparison has already been implied. I noted above that primitive accumulation consists of two processes: (1) capital accumulation, and (2) proletarianization. These are, in turn, part of a more general process: the creation of an “internal market” for capitalism, i. e., a market for means of production and a market for labor power. Yet what

William Roseberry



Structural interpretation along the Icotea Fault, Lake Maracaibo, Venezuela  

SciTech Connect

This structural interpretation, performed on an interactive workstation, corresponds to an area covered by three 3D seismic surveys in Lake Maracaibo. These surveys (Block I, Northern and Southern Lama) focus on the Icotea fault trend, which is one of the major structural features in the Maracaibo Basin. The present study is centered on the interpretation of the origin and evolution of this fault trend. The Maracaibo Basin evolved from an initial phase dominated by extensional tectonism to a later compressional phase. The Icotea fault is interpreted as the border of a Triassic-Jurassic half graben. Subsequent to the deposition of shelf sediments, the fault became reactivated during the Paleocene and Lower to Middle Eocene. During the change to compressional tectonics within the upper Eocene, the half graben became inverted. As an associated event during the structural inversion, a sinistral strike slip deformation took place along the fault. The latest stage of faulting developed during Miocene, and resulted in lateral offsets along the Icotea fault system.

Bueno, E.; Zubizarreta, J.; Pinto, J.; Taylor, C.; Prieto, E. (Maraven, S.A., Caracus (Venezuela))



Schooling for Twenty-First-Century Socialism: Venezuela's Bolivarian Project  

ERIC Educational Resources Information Center

The global dominance of neoliberal policy prescriptions in recent decades has been well documented, with particular implications for educational systems. These include reduced public expenditure and provision, the promotion of individual (parental) choice, competition, increased user-pays and the privatisation of education. Against this…

Griffiths, Tom G.



Late quaternary evolution of the Orinoco Delta, Venezuela  

USGS Publications Warehouse

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.

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



Mud volcanoes of the Orinoco Delta, Eastern Venezuela  

USGS Publications Warehouse

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.

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



[Aschersonia basicystis on scale insects (Homoptera: Coccidae) in Venezuela].  


The fungus Aschersonia basicystison scale insects (Homoptera: Coccidae) is described and illustrated on the basis of the examination of Venezuelan collections, using transmitted light and differential interference contrast optical microscopy. PMID:15762808

Rojas, T




Microsoft Academic Search

L'approccio comunemente utilizzato per il calcolo teorico del campo di deformazione indotto da una sorgente sismica in un mezzo elastico è basato sull'equivalenza fra una dislocazione di taglio elementare e una doppia coppia di forze puntiformi. Il campo prodotto da una sorgente di dimensioni finite viene poi ottenuto tramite sovrapposizione lineare dei campi generati da una distribuzione di doppie coppie

S. Tinti; A. Armigliato; A. Manucci


77 FR 58912 - Additional Designations, Foreign Narcotics Kingpin Designation Act  

Federal Register 2010, 2011, 2012, 2013

...Kingpin Act. Individual: 1. LOPEZ PERDIGON, Roberto Manuel; DOB 09 Sep 1971; POB Caracas, Venezuela; nationality Venezuela; citizen Venezuela; Passport C1771508 (Venezuela); alt. Passport 037325626 (Venezuela); National ID...



Evidence for a Younger Dryas glacial advance in the Andes of northwestern Venezuela  

Microsoft Academic Search

Deposits of push moraine, outwash and glaciolacustrine sediments, recovered from two areas in the northwestern Venezuelan Andes document the latest Pleistocene advance of Mérida ice. Underlying peats provide maximum ages on till and outwash evidently emplaced during the Younger Dryas (YD) climatic event. One example recovered from the Humboldt Massif, where the farthest extent of YD ice buried peat in

William C. Mahaney; M. W. Milner; Volli Kalm; Randy W. Dirszowsky; R. G. V. Hancock; Roelf P. Beukens



Mercury determination by cold vapour atomic absorption spectrometry in several biological indicators from Lake Maracaibo, Venezuela.  


Two sampling sessions were carried out in Lake Maracaibo and eight sites selected in four pairs one in front of the other (El Moján-Ancón de iturre, Santa Cruz de Mara-Punta de Palmas, Maracaibo-Punta de Leiva and San Francisco-La Rita). Specimens of Cynosción acoupa Maracaiboencis (curvina, n = 5), Oligoplites palometa (palometa, n = 5), Penaeus schmitti (shrimp, n = 20), and Polymesoda arctata (mussels, n = 20) were collected. For the curvina and palometa, muscle, brain, kidney, gill, liver and heart were analysed. Shrimp and mussels were analysed whole, without the shells. Samples were lyophilized and cold digested in a mixture of sulfuric, nitric and perchloric acids, potassium permanganate and hydrogen peroxide. Spectrometric determination was carried out using cold vapour atomic absorption spectrometry and sodium borohydride as reducing agent. Accuracy was tested with a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) RM50 Albacore Tuna, and against another method. The detection limit for Hg was 53 ng l-1. Good agreement was found between results for the analysis of SRM RM50 (Hg = 0.95 +/- 0.14 mg kg-1) and the assigned value furnished by NIST (Hg = 0.95 +/- 0.10 mg kg-1). Precision and the interference were also evaluated. Mercury concentrations in brain, kidney and heart tissues of the curvina and palometa were found to be higher than those in the muscle tissue. PMID:1580413

Colina de Vargas, M; Romero, R A



Paradoja de la desobediencia civil en Venezuela: la frustración de la acción colectiva  

Microsoft Academic Search

The purpose of this paper is to analyze civil disobedience and their collateral implications for the Venezuelan opposition. More precisely, rational choice will be the approach to explain the failure of civil disobedience as collective action. We attempt to disentangle how individual interest has helped the whole group's action (voluntarism), producing mistrust among the sectors organizing the protest as well

Marian Pierina Pérez


Feasibility Study for Vinccler Gas Production and Processing Facility Project, East Falcon, Venezuela.  

National Technical Information Service (NTIS)

This is a study to determine the feasibility of developing a gas production and processing facility project by Vinccler Oil and Gas, C.A. (Vinccler) for the La Vela Field Onshore Reserves located in the state of Falcon (East). In order to be viable, the p...



Sequential evolution of Lower Cretaceous carbonate platforms in the Maracaibo Basin, Venezuela  

Microsoft Academic Search

The sequence stratigraphic framework of the Upper Barremian to the Upper Cenomanian series was carried out in detail on cored material and well logs from Perija region and central part of Lake Maracaibo. Sediments are predominantly shallow marine carbonates (muddy lagoons, grainstone bars, pelecypod biostroms, intrabars), with an occasional siliciclastic input (nearshore sand bars, mixed tidal flats). Three second order

T. Jacquin; I. Azpiritxaga; B. Murat; M. F. Roberto



Microsatellites reveal widespread predominance of an invasive over an indigenous Bemisia tabaci in Venezuela  

Microsoft Academic Search

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest due to its capacity for producing strong infestations and transmitting\\u000a plant viruses. The New World putative species of B. tabaci complex (NW) is the indigenous whitefly of the Americas, but only the invasive Middle East-Asia Minor 1 putative species\\u000a of B. tabaci complex (MEAM1), commonly referred to as the

G. Romay; F. Geraud-Pouey; D. T. Chirinos; M. A. Santana; I. Galindo-Castro; L. M. Márquez


Assessment of shallow landslide susceptibility using artificial neural networks in Jabonosa River Basin, Venezuela  

Microsoft Academic Search

Landslides represent one of the most morphodynamic processes that affect the steep lands, and may destroy croplands as well as urban and industrial development. Landslide risk analysis can help government agencies to select suitable locations for development schemes and plan mitigation measures in unstable landslide-prone areas. This study describes an approach for assessing the landslide risk potential, mainly for shallow

H. Gómez; T. Kavzoglu



A Plasmid Involved in Chloramphenicol Production in Streptomyces venezuelae: Evidence from Genetic Mapping  

Microsoft Academic Search

SUMMARY To test the hypothesis that chloramphenicol production in Streptomyces vene- zuelae depends on the presence of a plasmid, mapping analysis was carried out by using eight markers in addition to chloramphenicol production and melanoid pig- ment formation. The sequence of the eight markers was determined on a circular linkage map as follows : -his-ude-str-leu-lys-met-iiv-pro-(his-). This sequence resulted in the




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

SciTech Connect

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.

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



Causes of seasonality in the chemistry ofa lake on the Orinoco River floodplain, Venezuela  

Microsoft Academic Search

Lake Tinco, which lies on the Orinoco floodplain, passes through four seasonal phases (filling, through-flow, drainage, and isolation), during which the lake volume changes 20-fold. During filling and through-flow, when the lake is inundated by river water, floating grasses (Paspalum repens) and phytoplankton grow rapidly, causing depletion of inorganic N and P between inflow and outflow, although phytoplankton biomass does




Presence of an emerging pathogen of amphibians in introduced bullfrogs Rana catesbeiana in Venezuela  

Microsoft Academic Search

Chytridiomycosis is an emerging fungal disease of amphibians responsible for mass mortalities and population declines globally. One hypothesis for its recent emergence is anthropogenic introduction of the causative agent Batrachochytrium dendrobatidis through trade in amphibians for pets, food and biocontrol. In this