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1

Venezuela: Lake Maracaibo  

article title:  Oil Slicks on Lake Maracaibo, Venezuela     View Larger Image Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between ... wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting ...

2013-04-18

2

Venezuela takes responsabilidad  

SciTech Connect

No federal government officials showed up at the Oct. 29 ceremony to lauch the Responsabilidad Integral program of Asoquim, the Venezuelan chemical industry association. But that did not discourage industry representatives. Industry has tried to keep the Ministry of Environment Affairs involved as much as possible, says Danay Zoppi de Perez, corporate v.p. with Grupo Quimico. But industry was proud to be doing it anyway, despite the absence of government. It's a private, proactive initiative. Asoquim's program is based on the six Responsible Care codes. At the ceremony, 56 companies from Asoquim's membership of 150, which represents 90% of chemicals production in the country, signed on. Signatories include stateowned Petroquimica de Venezuela (Pequiven), domestic private-sector firms, and most of the multinationls operating in Venezuela. The ceremony drew officials from the fire service and civil defense authorities who have to deal with spills and accidents.

Hunter, D.

1992-12-09

3

Astronomy in Venezuela  

NASA Astrophysics Data System (ADS)

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

Rosenzweig, Patricia

4

[Demographic profile of Venezuela].  

PubMed

Sources of demographic data for Venezuela include 11 population censuses conducted between 1873-1981, birth and death registration statistics, and the household sample survey. The average annual rate of population growth increase from 2.8% between 1920-40 to 3-4% thereafter. The population at the 1961 census was 7.52 million. According to preliminary data from the 1981 census, the population of 14.57 million is growing at an annual rate of 2.8%. 41.2% of the population is under 15 years old, implying a huge demand for educational and health services, housing and employment. The dependency rate in 1980 was 81.3% for the country as a whole, 100.4% in rural areas, and 76.0% in urban areas. The young age structure means that the population will continue to grow even if natality rates decline. The crude natality rate was estimated at 47.3/1000 for 1950-55, 36.0 for 1970-75, and 32.9 for 1980-85. Some rural areas still have natality rates of over 47/1000. The total fertility rate declined from 6.5 in 1950-55 to 4.1 in 1980-85. The decline in the natality rate reflects improving quality of life, availability of family planning services, urbanization, and access of women to productive activities and educational centers. The mortality rate was 12.3/1000 in 1950-55, 9.1 in 1960-65, in 1970-75, and has been estimated at 5.5 for 1980-85. Some rural areas have mortality rates of 8.1. The infant mortality rate was 50.2/1000 in 1971 and 34.3 in 1980. Life expectancy at birth is about 69 years. During the 1920s, Venezuela unerwent expansion in infrastructure and technological utilization, generating rapid urbanization. 39.2% of the population was urban in 1941, compared to 78.8% in 1980. The significance of urbanization in Venezuela is due to the rapidity as well as the diffusion of the process. The household sample survey for the 2nd half of 1980 indicated a total of 8.16 million employed and an activity rate of 32.1% overall, 46.4% for males and 17.7% for females. The demographic situation of Venezuela does not appear alarming if viewed in isolation, but the deficit of some 500,000 housing units, the million unemployed, the importation of about 75% of the country's food, the stagnation of agriculture, the lower than subsistence level of about 40% of incomes, and the lack of population policies suggest that the 24.7 million inhabitants projected for 2000 will pose a considerable challenge to the nation. PMID:12266336

Quintero, I

1984-04-01

5

ALBA: A Political Tool for Venezuela’s Foreign Policy  

Microsoft Academic Search

Despite its founding by Hugo Chávez on the heels of the failed Free Trade Area for the Americas (FTAA) negotiations which took place November 2003, the Bolivarian Alliance for the Americas (ALBA, as it is known for its Spanish acronym) has evolved into a political tool that uses “social power” to facilitate Venezuela?s positioning as the leader of the anti-U.S.

Erich de la Fuente

2011-01-01

6

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.

7

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)

1996-08-01

8

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.

anon.

2003-10-20

9

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...

1985-01-01

10

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

1986-01-01

11

The new emergency structure of the Istituto Nazionale di Geofisica e Vulcanologia during the L’Aquila 2009 seismic sequence: the contribution of the COES (Seismological Emergency Operation Center - Centro Operativo Emergenza Sismica)  

NASA Astrophysics Data System (ADS)

The Centro Nazionale Terremoti (CNT - National Earthquake Center), departement of Istituto Nazionale di Geofisica e Vulcanologia (INGV), has designed and setup a rapid response emergency structure to face the occurrence of strong earthquakes. This structure is composed by a real time satellite telemetered temporary seismic network (see Abruzzese et al., 2009 Fall AGU) used to improve the hypocentral locations of the INGV National Seismic Network, a stand alone temporary seismic network whose goal is primarily the high dynamic/high resolution data acquisition in the epicentral area and a mobile operational center, the COES (Centro Operativo Emergenza Sismica, Seismological Emergency Operational Center). The COES structure is a sort of mobile office equipped with satellite internet communication that can be rapidly installed in the disaster area to support all the INGV staff operative needs and to cooperate with the Civil Protection department (DPC) aggregating all the scientific information available on the seismic sequence and providing updated information to Civil Protection for the decision making stage during the emergency. The structure is equipped with a heavy load trolley that carries a 6x6 inflatable tent, a satellite router, an UPS, computers, monitors and furniture. The facility can be installed in a couple of hours in the epicentral area and provides a full featured office with dedicated internet connection and VPN access to the INGV data management center in Rome. Just after the April 6 2009 Mw 6.3 earthquake in L’Aquila (Central Italy) the COES has been installed upon request of the Italian Civil Protection (DPC) in the DICOMAC (Directorate of Command and Control - which is the central structure of the DPC that coordinates the emergency activities in the areas affected by the earthquake) located in the Guardia di Finanza headquarters in Coppito nearby L'Aquila (the same location that hosted the G8 meeting). The COES produces real time reports on the seismic sequence evolution constituted by a detailed sequence map, histograms showing the evolution of the magnitude and the number of earthquakes in time and a daily event list. Moreover, it is possible to see the real time hypocentral locations using “SISMAP” (Doumaz et al., 2008), the same tool used in the Seismic Monitoring Center in Rome. During the emergency the COES has been also a reference information point for all people involved in the crisis management and has provided also psychological support to the rescuers and to the earthquake affected population. This education and outreach activity has proved to be extremely effective. References Abruzzese L. et al., AGU Fall Meeting 2009. Doumaz F. et al., Geomedia, speciale geologia, pp. 10-13, 2008.

Moretti, M.; Govoni, A.; Nostro, C.; La Longa, F.; Crescimbene, M.; Pignone, M.; Selvaggi, G.; Working Group, C.

2009-12-01

12

State and Power after Neoliberalism in Bolivarian Venezuela.  

E-print Network

??ABSTRACTState and Power after Neoliberalism in Bolivarian VenezuelaDonald V. KingsburyState and Power after Neoliberalism in Bolivarian Venezuela examines the limits and possibilities of collective subject… (more)

Kingsbury, Donald V.

2012-01-01

13

Investigation into the hydrocarbon sector in Venezuela  

Microsoft Academic Search

Technological dependence constitutes a fundamental difficulty which confronts developing countries. The Venezuelan economy depends almost exclusively on the hydrocarbon industry, being characterized so that its efficiency rests above the bases of technological advances. The fundamental aspects, priorities, resources, and the actions which should be taken because Venezuela may be confronted with a decision on technological dependence of the National Petroleum

Ferrer

2009-01-01

14

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.

1986-01-01

15

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

16

New Maracaibo plant called most advanced. [Venezuela  

Microsoft Academic Search

A new gas-injection plant, recently put on stream, raises to 10 the number of oil-field-repressuring facilities in Lake Maracaibo, Venezuela. The combined capacity of these installations is 2,015 MMcfd. The new plant is Menegas I, the most advanced ever built. The 45 MMcfd unit is owned and operated by Mene Grande Oil Co.; it is located in the Ceuta field

1970-01-01

17

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:...

2013-12-23

18

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

Federal Register 2010, 2011, 2012, 2013

...Silicomanganese From India, Kazakhstan, and Venezuela...silicomanganese from India, Kazakhstan, and Venezuela...currently valid Office of Management and Budget (OMB) number...silicomanganese from India, Kazakhstan, and Venezuela...reasonably foreseeable time. It will assess...

2012-10-01

19

International Marketing Information Service: Country Market Survey. Venezuela.  

National Technical Information Service (NTIS)

Venezuela, with its high gross national product, sound economy, stable government, and orientation twoard U.S. suppliers, must be regarded as one of the best U.S. overseas markets. Among Latin American countries, in 1968, Venezuela ranked second as a purc...

H. J. Mueller

1969-01-01

20

New species and records of Hydroptilidae (Trichoptera) from Venezuela  

PubMed Central

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

Thomson, Robin E.; Holzenthal, Ralph W.

2012-01-01

21

[Increasing difficulties for scientific publication in Venezuela].  

PubMed

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

2014-03-01

22

Malaria Control and Elimination,1 Venezuela, 1800s-1970s  

PubMed Central

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

Villegas, Leopoldo; Udhayakumar, Venkatachalam

2014-01-01

23

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

PubMed

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

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

2014-10-01

24

Current Space Projects of the Bolivarian Republic of Venezuela  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

25

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. PMID:21998503

Linero-Arana, Ildefonso; Diaz Diaz, Oscarn

2011-01-01

26

MODIS detects oil spills in Lake Maracaibo, Venezuela  

Microsoft Academic Search

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

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

2003-01-01

27

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

Microsoft Academic Search

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

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

28

Anthropogenically induced fish diversity reduction in Lake Valencia Basin, Venezuela  

Microsoft Academic Search

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

Héctor López-Rojas; Ana L. Bonilla-Rivero

2000-01-01

29

TEMPORAL AND SPATIAL PATTERNS OF MALARIA REINFECTION IN NORTHEASTERN VENEZUELA  

Microsoft Academic Search

We stratified the risk of malaria transmission (Plasmodium vivax) in 35 villages along a coastal range in northeastern Venezuela (51 km2) where the main vector is the mosquito Anopheles aquasalis. After 20 years without local malaria transmission, reinfection of the entire area occurred from May to December 1985 by local (continuous) and jump (discontinuous) dispersal. Epidemiologic, environmental, and vector variables

ROBERTO BARRERA; MARIA E. GRILLET; YADIRA RANGEL; JESUS BERTI

1999-01-01

30

Molecular Epidemiologic Source Tracking of Orally Transmitted Chagas Disease, Venezuela  

PubMed Central

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

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

2013-01-01

31

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

PubMed

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

2013-06-01

32

Explaining left-wing electoral success in Brazil and Venezuela  

Microsoft Academic Search

While the electoral victories of the Brazil's Partido dos Trabahaldores (PT) and Venezuela's Movimiento Quinta Republica (MVR) represent a strengthening of democratic electoral mechanisms as a vehicle for both the expression of popular opinion, and socially egalitarian policy, it may equally represent a continuation of political instability, in which frequent shifts in political preferences contribute to both countries' difficulties in

Stephanie Stern

2004-01-01

33

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

Microsoft Academic Search

The privileged location of Venezuela along an active interplate deformation belt, despite of being a ``so-called'' developing country, has led to a long paleoseismic tradition as attested by 45 trench assessments since 1968. Since then, a first 2-trench study was carried out by the American Woodward Clyde company across the Oca fault at Sinamaica. Since 1980, all further paleoseismic studies

Franck A. Audemard M

2005-01-01

34

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.

1985-01-01

35

Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela  

SciTech Connect

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

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

2007-10-26

36

CR Mission ORENOQUE Venezuela 07 25 mars 2000  

E-print Network

CR Mission ORENOQUE Venezuela 07 ­ 25 mars 2000 Jean GUILLARD Cette mission est la première de l des zones estuariennes du delta de l'Orénoque ». Une mission exploratoire a été réalisée en octobre 99 afin de préciser les conditions d'échantillonnage (cf. CR Mission oct. 99). Ce programme est une

Guillard, Jean

37

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

PubMed

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

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

2014-01-01

38

CYCLIC STEAM INJECTION IN THE QUIRIQUIRE FIELD OF VENEZUELA  

Microsoft Academic Search

For the past 4 yr, Creole Petroleum Corp. has been actively testing the use of steam as a production stimulant in the Quiriquire Field of Eastern Venezuela. The method being tested is the so-called ''huff-and-puff'' method where steam is injected into the formation and the well later returned to production. This method of stimulation has been used for 8 wells

R. W. Payne; Gabaniel Zambrano

1965-01-01

39

Notomicrus josiahi, a new species of Noteridae (Coleoptera) from Venezuela.  

PubMed

Notomicrus josiahi sp. n. is described from a stream in southern Venezuela. The species differs from others in the genus in 1) large size for the genus (1.48-1.53mm), 2) smooth, shiny dorsal surface with indistinct punctation and mircroretic-ulation, 3) distinct coloration with head and pronotum yellow and elytron bicolored with basal portion black and apical portion brown, and 4) distinctive male genitalia. A checklist of the valid, known species of Notomicrus is given. PMID:24699587

Miller, Kelly B

2013-01-01

40

Seroepidemiology of bovine anaplasmosis and babesiosis in Venezuela  

Microsoft Academic Search

The serological prevalence of bovine anaplasmosis and babesiosis in the Centro-Occidental region of Venezuela was determined using the indirect fluorescent antibody (IFA) and latex agglutination (LAT) tests.Anaplasma marginale IFA and LAT prevalence rates were 57·7 and 48·6% respectively for cattle of all ages and breeds. The respective prevalence of IFA activity toB. bigemina andB. bovis was 78·2 and 38·8%. The

M. A. James; A. Coronado; W. Lopez; R. Melendez; M. Ristic

1985-01-01

41

Venezuela bets on heavy crude for long term  

Microsoft Academic Search

In the heart of eastern Venezuela lies the Orinoco Belt, a vast reserve of heavy crudes and bitumen that equate to only 8° to 10° API. At the beginning of the 1920s, a number of foreign companies explored this area. However, they realized that this crude was too heavy to be produced commercially and abandoned their exploratory sites. In 1978--1980,

1997-01-01

42

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

PubMed Central

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

Diazgranados, Mauricio; Morillo, Gilberto

2013-01-01

43

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

Microsoft Academic Search

The privileged location of Venezuela along an active interplate deformation belt, despite of being a “so-called” developing country, has led to a long paleoseismic tradition as attested by 45 trench assessments since 1968. Since then, a first 2-trench study was carried out by the American Woodward–Clyde company across the Oca fault at Sinamaica. Since 1980, all further paleoseismic studies have

2005-01-01

44

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.

1994-01-01

45

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

NASA Astrophysics Data System (ADS)

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

Audemard M., Franck A.

2005-10-01

46

Interruption of Onchocerca volvulus transmission in Northern Venezuela  

PubMed Central

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

2013-01-01

47

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: http://sismicidad.ciens.ula.ve. As well, the "Historia Sísmica de Colombia 1550-1830" (Seismic History in Colombia 1550-1830) data base, in CD-ROM, by Espinosa Baquero (2003) and the historic seismicity information system of Colombia (Servicio Geológico Colombiano-Universidad Nacional de Colombia), published on the internet in 2012: http://agata.ingeominas.gov.co:9090/SismicidadHistorica/. c) Macroseismic studies for the development of intensity attenuation equations and the quantification and revaluation of basic historic earthquake parameters using isoseismal maps (Rengifo et al., Palme et al., Salcedo et al., among others) and procedures such as Boxer and Bakun & Wentworth (Palme et al., Dimaté, among others), which have produced significant changes in the parameters of some of the large earthquakes. d) Symposiums of researchers to promote interest and development in the discipline, including Jornadas Venezolanas de Sismología Histórica (Venezuelan Congress of Historical Seismology), held periodically between 1997 and 2012, the year of the sixth edition. As well, national and international research groups have been formed to work actively on global projects, such as the Geophysics Laboratory of Universidad de Los Andes in Venezuela. In the future, international groups will be formed to jointly treat issues including localization and size of destructive events along borders, common scales for the evaluation of intensities, integrated data bases, etc. Additionally the methods employed will be validated by paleoseismology, neotectonics and instrumental seismicity, among others.

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

2013-05-01

48

An investigation of rainfall variability and distribution in Venezuela  

E-print Network

monthly rainfall for selected stations along the coast of Venezuela. 34 20. Change in monthly precipitation bet~san January and February expressed as a percentage of the annual tc tal. 42 21. Change in monthly precipitation bet~san February and March... expressed as a percentage of the annual total. 43 22. Change in monthly precipitation between March and April expressed as a percenmage of the annual total. Change in monthly precipitation bet~san April and !May expressed as a percentage of the annual...

Gibson, Donald Reid

2012-06-07

49

Venezuela No. 1 oil import source in S. America  

SciTech Connect

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

Not Available

1992-08-10

50

Paralytic shellfish poisoning (PSP) in Margarita Island, Venezuela.  

PubMed

A severe outbreak of Paralytic Shellfish Poisoning (PSP) occurred in Manzanillo and Guayacán, northwestern coast of Margarita Island, Venezuela, between August and October 1991. A bloom of dinoflagellates including Prorocentrum gracile, Gymnodinium catenatum and Alexandrium tamarense seemed to be responsible for this outbreak. Levels of PSP toxins in mussels (Perna perna) exceeded the international safety limit of saxitoxin, 80 microg STX/100 microg meat. PSP toxin values varied between 2548 and 115 microg STX/100 g meat in Manzanillo, and between 1422 and 86 microg STX/100 g meat in Guayacán. At both locations, the highest levels were detected in August, when 24 patients exhibited typical symptoms of PSP toxicity after consuming cooked mussels (16 required hospitalization). A high pressure liquid chromatographic (HPLC) procedure was recently used on the 1991 samples. The major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcSTX), but low concentrations of saxitoxin were also found in Manzanillo samples. Gonyautoxins GTX1, GTX2 and GTX3 were detected only at Guayacán, while in both locations, decarbamoylgonyatouxin (dcGTX2,3) toxins were detected. These findings represent the first time that causative toxins of PSP in Venezuela have been chemically identified, and confirm the presence of dcSTX and dcGTX in mussels from the Caribbean Sea. The presence of dcSTX and dcGTX in shellfish is indicative that Gymnodinium catenatum was a causative organism for outbreak of PSP. PMID:17465121

La Barbera-Sánchez, Amelia; Franco Soler, Jose; Rojas de Astudillo, Luisa; Chang-Yen, Ivan

2004-09-01

51

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

E-print Network

Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1 Daniel M. Sigman,2: Cariaco Basin, denitrification, nitrogen isotopes Citation: Thunell, R. C., D. M. Sigman, F. Muller-Karger, Y. Astor, and R. Varela (2004), Nitrogen isotope dynamics of the Cariaco Basin, Venezuela, Global

Sigman, Daniel M.

52

Estado nutricional en niños preescolares que asisten a un jardín de infancia público en Valencia, Venezuela  

Microsoft Academic Search

SUMMARY. Nutritional status in preschoolers attending a public day-care center in Valencia, Venezuela. With the purpose of evaluating nutritional status in a group of preschoolers attending a public day care center in Valencia, Venezuela (2002), a research was made for social stratus, anthropometric variables; weight, height and arm circumference, hemoglobin, seric retinol, presence of parasitosis and food consumption, as well

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

53

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

AHMET UNVER; MIRIAM PEREZ; NELSON ORELLANA; HAIBIN HUANG; YASUKO RIKIHISA; Departmento de Medicina Cirugia

2001-01-01

54

The Mexican Sistema de Alerta Sismica (SAS) Experience  

Microsoft Academic Search

The Mexico City's SAS is an Early Warning System developed in accordance with recommendations of foreign and national seismology experts, after the disaster generated in 1985 by the M8.1 Michoacan earthquake. The SAS aim is to help mitigate future seismic disasters in Mexico City (MC), mainly if the big forecast \\

J. Espinosa-Aranda; F. Rodriguez

2003-01-01

55

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. PMID:16485478

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

2005-01-01

56

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

PubMed

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

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

2004-06-01

57

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

PubMed

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

Gulbas, Lauren E

2013-03-01

58

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

1999-08-01

59

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.

2013-05-01

60

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

E-print Network

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

Oliva, Adriana; Short, Andrew E. Z.

2012-07-06

61

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

E-print Network

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

Deghirmandjian, Odilia

2012-06-07

62

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

SciTech Connect

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

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

1995-04-01

63

Huntington disease mutation in Venezuela: age of onset, haplotype analyses and geographic aggregation  

Microsoft Academic Search

The aggregation of patients with Huntington's disease (HD) around Lake Maracaibo, Zulia State, Venezuela, is widely recognized,\\u000a but the epidemiology of HD in the whole country is relatively unstudied. We have examined 279 individuals from 60 unrelated\\u000a affected families residing in various areas of Venezuela for the presence of CAG repeats and other features associated with\\u000a HD. The number of

Irene Paradisi; Alba Hernández; Sergio Arias

2008-01-01

64

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

PubMed Central

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

Dorr, Laurence J.; Stergios, Basil

2014-01-01

65

Confronting Health Disparities: Latin American Social Medicine in Venezuela  

PubMed Central

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

Mantini-Briggs, Clara

2009-01-01

66

New Insights into Chloramphenicol Biosynthesis in Streptomyces venezuelae ATCC 10712.  

PubMed

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

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

2014-12-01

67

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

PubMed

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

2012-06-01

68

Caribbean basin framework, 4: Maracaibo basin, northwestern Venezuela  

SciTech Connect

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

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

1991-03-01

69

EVALUACIÓN MICROBIOLÓGICA DE PESCADOS CONGELADOS PRODUCIDOS EN CUMANÁ, ESTADO SUCRE, VENEZUELA Microbiological Evaluation of Frozen Fish Produced in Cumana, Sucre State, Venezuela  

Microsoft Academic Search

The purpose of this research was to evaluate the frequency of bacteria and fungi, in samples of slices of congealed mountain range (Scomberomorus spp) and merluza (Merluccius spp.), produced in Cumaná, Sucre state, Venezuela. 60 samples, 30 from mountain range (Scomberomorus spp) and 30 from mer- luza (Merluccius spp.), sold in three supermarkets were col- lected forming units colony per

Sara Centeno; Rossianny Rodríguez

2005-01-01

70

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

71

Tectonothermal modeling of hydrocarbon maturation, Central Maracaibo Basin, Venezuela  

SciTech Connect

The petroliferous Maracaibo Basin of northwestern Venezuela and extreme eastern Colombia has evolved through a complex geologic history. Deciphering the tectonic and thermal evolution is essential in the prediction of hydrocarbon maturation (timing) within the basin. Individual wells in two areas of the central basin, Blocks III and V, have been modeled to predict timing of hydrocarbon generation within the source Upper Cretaceous La Luna Formation, as well as within interbedded shales of the Lower-Middle Eocene Misoa Formation reservoir sandstones. Tectonic evolution, including burial and uplift (erosional) history, has been constrained with available well data. The initial extensional thermal regime of the basin has been approximated with a Mackenzie-type thermal model, and the following compressional stage of basin development by applying a foreland basin model. Corrected Bottom Hole Temperature (BHT) measurements; from wells in the central basin, along with thermal conductivity measurements of rock samples from the entire sedimentary sequence, resulted in the estimation of present day heat flow. An understanding of the basin`s heat flow, then, allowed extrapolation of geothermal gradients through time. The relation of geothermal gradients and overpressure within the Upper Cretaceous hydrocarbon-generating La Luna Formation and thick Colon Formation shales was also taken into account. Maturation modeling by both the conventional Time-Temperature Index (TTI) and kinetic Transformation Ratio (TR) methods predicts the timing of hydrocarbon maturation in the potential source units of these two wells. These modeling results are constrained by vitrinite reflectance and illite/smectite clay dehydration data, and show general agreement. These results also have importance regarding the timing of structural formation and hydrocarbon migration into Misoa reservoirs.

Manske, M.C. [OMNI Laboratories, Inc., Maracaibo (Venezuela)

1996-08-01

72

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.

2013-05-01

73

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

NASA Astrophysics Data System (ADS)

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

Rosenzweig, P.

2006-08-01

74

A study of beef cattle marketing in Venezuela and the marketing margins between the farm and retail levels of prices  

E-print Network

. . . . . Organization of the Venezuela Beef Marketing System. 36 43 Cattle collection. Transportation. Storage. F" nancing. Standarization. Pricinc. Geograptiy of beef cattle slaughter, . Need for decentralizarz. on. . '. . . . . . . . . 45 47 48 49 49...'on, 1937, 1950 and 196B. Beef cattle numbe s illecally ;, tr oduced in Venezuela, 1960-1972 21 Slaughter cattle, production of beef, and dre sed weight per head in Venezuela, 1950- 1973. . . . 24 Price elastici ty of demand at retail; per- centage...

Acosta, Sady Ines Borjas-Paez

2012-06-07

75

EFECTO DE LA APLICACIÓN DE RESIDUOS ORGÁNICOS SOBRE EL CULTIVO DEL MAÍZ EN SUELOS DEGRADADOS DEL ESTADO YARACUY, VENEZUELA  

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

2005-01-01

76

Francisco de Miranda and the Problem of Slavery in Venezuela: New Ideas and Concerns  

Microsoft Academic Search

This works examines the historic antecedents of the abolition of slavery in Venezuela in two parts: 1) The impact of Haiti's independence on Latin American and Caribbean colonies. 2) Francisco de Miranda's trajectory as Precursor of our emancipation; his opinions with regard to the Haitian revolution, and the help its leaders offered him in 1806. It underlines the contradiction between

José Marcial Ramos Guédez

2007-01-01

77

Rejuvenation of a giant oil field-Quiriquire Field, Venezuela: A team approach  

Microsoft Academic Search

Quiriquire field is located in the Maturin basin of eastern Venezuela, at the southeastern corner of the Serrania del Interior mountain range. Since its discovery in 1928, the field has produced over 750 MMBO from a stratigraphically trapped, shallow, Pliocene alluvial fan (Quiriquire Formation). A deep oil zone, the Los Jabillos sand of Oligocene age, was discovered in 1952 on

H. Friestad; R. Hull; D. Miller

1996-01-01

78

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

E-print Network

Urdaneta* , Altaf Lal , Christian Barnabe´ , Bruno Oury , Ira Goldman , Francisco J. Ayala§ , and Michel in the African sample. These results support the hypothesis that the population structure of P. falciparum in Venezuela, but not in Africa, is predominantly clonal. However, the impact of genetic recombina- tion

79

EL PRODUCTOR COMERCIAL DE CERDOS Y SU PERCEPCION CON RESPECTO A NUEVOS PARADIGMAS TECNOLOGICOS: CASO VENEZUELA  

Microsoft Academic Search

The modern pork sector in Venezuela practically born in 1958, basically sustained in the governmental strategy founded on the policy of imports substitution like development model for developing countries including the Latin American. Particularly the industrialist sector of pig meat it is developed to under this scheme. The production system of pigs (the farms) is enough similar to the one

Francisca A Viloria

80

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

Microsoft Academic Search

The aim of this research work is a geochemical, mineralogical, and textural characterization of spontaneously smouldered coal-derived products in northwestern Venezuela (Cerro Pelado Formation, some 10km from Pedregal city). Several solid samples were collected from this formation, six of unweathering coal, an other six of resulting unmelted rocks forming on a surface coal bed, and the last four of mineralizations

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

2009-01-01

81

Actividad microbiana en suelos de sabanas de los Llanos Orientales de Venezuela convertidas en pasturas  

Microsoft Academic Search

Micr obial activity in Eastern Venezuelan savannas turned into grasslands. We studied the effects of season and management practices on chemical properties and biochemical parameters in a typical Ultisol soil of native and introduced pastures of the Eastern savannas of Venezuela. Sseason, soil management, and their interaction, significantly affected chemical properties and biochemical parameters. The total carbon and the water

Y. Gómez; J. Paolini

2006-01-01

82

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

PubMed

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

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

1980-05-01

83

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

84

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

E-print Network

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

Garcia, Ivette

2012-06-07

85

PATRON DE LIPIDOS EN PREESCOLARES DE BAJOS RECURSOS SOCIOECONOMICOS (VALENCIA, VENEZUELA)  

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

86

Ariid sea catfishes from the coeval Pirabas (Northeastern Brazil), Cantaure, Castillo (Northwestern Venezuela), and Castilletes  

E-print Network

), and the corresponding fossil records are the product of evolutionary events in the Proto- Caribbean. The objective of this paper was to describe a fossil ariid skull from the early Miocene Pirabas Formation (Brazil Venezuela), and Castilletes (North Colombia) formations (early Miocene), with description of three new

Bermingham, Eldredge

87

Valores y estética del paisajismo japonés: Su historia y aporte para Venezuela  

Microsoft Academic Search

On the occasion of a plan to construct the first Japanese garden in Venezuela, this paper discusses the purpose, essentials, main classes and history of traditional Japanese landscape design, with an eye on the construction of the garden in question and its contribution to intercultural dialogue. The philosophical values and main parameters of beauty of Japanese aesthetics are analyzed; guidelines

Ignacio Aristimuño

88

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

E-print Network

distinct tectonic blocks that move independently of the surrounding plates. For example, the triangular­slip Oca­Ancon (OA) Fault to the north, is moving northeastward relative to the SA plate regional tectonics in western Venezuela. Using the method proposed by Wolfe and Silver (1998), SKS

Niu, Fenglin

89

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

ERIC Educational Resources Information Center

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

Cole, Mike

2014-01-01

90

Tectonic inheritance, crustal architecture, and contrasting structural styles in the Venezuela Andes  

Microsoft Academic Search

Surface and subsurface data image contrasting structural styles for the two flanks of the Venezuela Andes. In the north, a flexural basin developed in Neogene times between the Andes and the Lake Maracaibo. North verging thrusts are mainly detached in the pre-Cretaceous substratum and form a deeply buried antiformal stack. Secondary décollement levels occur both in the Upper Cretaceous and

Bernard Colleta; François Roure; Bruno De Toni; Daniel Loureiro; Herminio Passalacqua; Yves Gou

1997-01-01

91

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

92

Democracy and state bias in Latin America: Some lessons from Mexico, Peru and Venezuela  

Microsoft Academic Search

This discussion considers why democracy has not so far led to the creation of impartial, honest and effective state institutions in Mexico, Venezuela and Peru. The explanation offered is essentially historical?institutional. Non?impartial (that is, biased) types of governance have a tendency to reproduce themselves over time due to the advantages that they offer to the powerful. However this observation, while

George Philip

1999-01-01

93

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

1980-01-01

94

ACTITUD DE MÉDICOS Y ESTUDIANTES DE MEDICINA FRENTE A LA EUTANASIA. MÉRIDA. VENEZUELA  

Microsoft Academic Search

Attitudes of physicians and medicine students towards euthanasia. Mérida. Venezuela. Euthanasia creates a dilemma for medical personnel, and creates controversy between those who argue on its favour and those who argue against it. The object of this paper is to know the attitudes on this subject held by physicians and last year medical students in the Autonomous Institute University Hospital

Rossana Mazzari; Sulin Wong; Magali López; Fernando Rivas

95

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

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

96

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

ERIC Educational Resources Information Center

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

Muhr, Thomas

2010-01-01

97

Volatile compounds from Tagetes pusilla (Asteraceae) collected from the Venezuela Andes.  

PubMed

The essential oil from the leaves of Tagetes pusilla Kunth (Asteraceae) collected from Mérida, Venezuela, was analyzed by GC/MS. A yield of 0.38% oil was obtained by hydrodistillation. Only two components, trans-anethole and 4-allylanisole were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base. PMID:20839636

Buitrago, Diolimar; Rojas, Luis B; Rojas, Janne; Morales, Antonio

2010-08-01

98

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

PubMed

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

2014-01-01

99

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

2008-01-01

100

Un Modelo Cinematico para la Interpretacion Tridimensional de Proyecciones Poliedricas.  

E-print Network

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

Ros, Lluís

101

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

E-print Network

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

Fischer-Hoffman, Cory

2008-08-20

102

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

E-print Network

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

Parisca-Blanco, Sonia

2005-01-01

103

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

104

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)

1996-08-01

105

Potential effects of global climatic change on the phenology and yield of maize in venezuela  

Microsoft Academic Search

Simulated impacts of global and regional climate change, induced by an enhanced greenhouse effect and by Amazonian deforestation, on the phenology and yield of two grain corn cultivars in Venezuela (CENIAP PB-8 and OBREGON) are reported. Three sites were selected:Turén, Barinas andYaritagua, representing two important agricultural regions in the country. The CERES-Maize model, a mechanistic process-based model, in theDecision Support

Carlos E. Maytín; Miguel F. Acevedo; Ramón Jaimez; Rigoberto Andressen; Mark A. Harwell; Alan Robock; Aura Azócar

1995-01-01

106

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

2006-01-01

107

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

Microsoft Academic Search

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

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

1999-01-01

108

Social change, population policies, and fertility decline in Colombia and Venezuela  

Microsoft Academic Search

This paper takes a comparative case-study approach to examine the social and policy correlates of fertility decline. The analysis compares fertility behavior across a mature and young cohort of women in Colombia and Venezuela, two countries that experienced rapid demographic change under dissimilar socioeconomic and population policy conditions. Based on the distinction between birth-spacing and birth-stopping behavior the analysis tests

Emilio A. Parrado

2000-01-01

109

The Cuba-Venezuela Alliance: “Emancipatory Neo-Bolivarismo” Or Totalitarian Expansion?  

Microsoft Academic Search

This study examines the background as well as the ideological foundations underpinning the Cuba-Venezuela alliance. Castro and Chavez are now trying to consolidate a new political axis in Latin America, funded by Chavez’ oil diplomacy. Similarities with the Cuban experiment are highlighted, as well as Castro’s collaboration with the leadership of the Movimiento Revolucionario Bolivariano-MBR 200. The various dimensions of

Hernán Yánez

2005-01-01

110

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

PubMed

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

Cermeño Zambrano, Fernando G De J

2002-01-01

111

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

USGS Publications Warehouse

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

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

1988-01-01

112

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.

1993-08-01

113

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

PubMed

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

Martin Frechilla, J J

1996-01-01

114

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.

1992-10-01

115

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

PubMed

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

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

1980-07-01

116

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. PMID:22984519

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

2012-01-01

117

Paleosols and Andean uplift in Venezuela: assessing competing hypotheses of relict tropical soils versus paleohydrogeochemical variations  

NASA Astrophysics Data System (ADS)

Paleosols in northern Venezuela, which have formed in residual regoliths of metaargillite rock complexes, have been considered to have developed in tropical, humid climates at low elevation. Their reddish colors and clay-enriched horizons have been used to support the hypothesis of significant recent uplift of the Andes Mountains in Late Quaternary time. We suggest an alternative hypothesis of long-term (+5 Myr) pedogenesis in a paleohydrogeochemical regime, characterized by fluctuating redox conditions at high elevation (2000-2500 m a.s.l.); the evidence for this redox history is the presence of Mn-Fe nodules in the surface epipedon. The sites, though relatively dry now, are interpreted to have been much wetter in the past, with soil moisture levels capable of translocating clay to form argillic horizons. The presence of thick Ah horizons, complete with large (1-2 mm) Mn-Fe nodules and approximately 30 cm thick argillic horizons, suggests long-term pedogenesis. The previous classification of these paleosols as Oxisols is untenable because of the presence of a mollic epipedon and the concentration of Mn-Fe nodules in the epipedon. The paleosols bear some resemblance to Placosols of the Canadian taxonomy, previously described for the maritime cool, moist climates of the Pacific and North Atlantic areas of Canada, but in Venezuela they occur without an impermeable subsurface Fe oxide layer. In the US taxonomy, they are classified as Typic or Aridic Argiustolls.

Mahaney, W. C.; Milner, M. W.; Bezada, M.; Kalm, V.; Hancock, R. G. V.

2002-10-01

118

Evaluación física de tierras para cuatro sistemas agroforestales en los sectores Piedra Azul y la Ciénaga, estado Trujillo-Venezuela Land physical evaluation for four agroforestry systems in Piedra Azul and the Cienaga sectors, Trujillo State-Venezuela  

Microsoft Academic Search

An evaluation of soil components was carried out in two pilot areas of 1.5 ha each, located in Piedra Azul and La Ciénaga sectors, pertaining to the Motatán River watershed, State of Trujillo, Venezuela. The purpose of the study was to determine the adaptability of some fruit and forestry species, sorted out by agro-forestry land use types (LUT). In order

Edgar Jaimes; José G. Mendoza; Rafael Rangel

2004-01-01

119

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

Microsoft Academic Search

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

TEOLINDA CARRILLO-ROSARIO Y GLENDA

120

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

SciTech Connect

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

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

1991-03-01

121

DESCRIPTION OF A NEW TROPICAL SUBSPECIES OF THE BLACK SWALLOWTAIL BUTTERFLY, PAPILIO POLYXENES (LEPIDOPTERA: PAPILIONIDAE) FROM VENEZUELA  

Microsoft Academic Search

This paper aims to describe Papilio polyxenes costarum, a new subspecies, whose populations come from the Cordillera de la Costa Central of northern Venezuela. The populations of this country have traditionally been identified as belonging to the subspecies americus Kollar, 1850, which flies in Colombia and integrates to the new subspecies in the Andes of the Cordillera de Merida in

Andrés M. Orellana-B

122

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

Microsoft Academic Search

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

Stephen G. Perz; Carlos Aramburú; Jason Bremner

2005-01-01

123

Envenomation by neotropical opisthoglyphous colubrid Thamnodynastes cf. pallidus Linne, 1758 (Serpentes:Colubridae) in Venezuela.  

PubMed

This is a case report of a "non-venomous" snake bite in a herpetologist observed at the Sciences Faculty of the Universidad de los Andes (Mérida, Venezuela). The patient was bitten on the middle finger of the left hand, and shows signs of pronounced local manifestations of envenomation such as bleeding from the tooth imprint, swelling and warmth. He was treated with local care, analgesics, and steroids. He was dismissed from the hospital and observed at home during five days with marked improvement of envenomation. The snake was brought to the medical consult and identified as a Thamnodynastes cf. pallidus specimen. This report represents the first T. pallidus accident described in a human. PMID:15517037

Diaz, Fresnel; Navarrete, Luis F; Pefaur, Jaime; Rodriguez-Acosta, Alexis

2004-01-01

124

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

PubMed

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

Hernández-Rosas, José Ibrahin

2004-01-01

125

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

PubMed

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

2014-01-01

126

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

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. PMID:24553611

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

2014-01-01

127

Molecular basis of phenylketonuria in Venezuela: presence of two novel null mutations.  

PubMed

This report describes the mutational spectrum and linked haplotypes of the phenylalanine hydroxylase gene in Venezuela. In this study, we have detected European mutations such as IVS10nt-11, R243Q, and R408W on the same haplotype background (6.7, 1.8, and 2.3, respectively) as in Europe. In this sample, we have found two novel mutations: S349L detected in two homozygous siblings on the background of haplotype 6.7, and a small deletion, P314fsdelC, that results in a frameshift and a premature stop codon detected on the background of haplotype 4.3. The definite demonstration that mutation S349L results in a nonfunctional protein was shown by expression analysis in prokaryotic and eukaryotic systems. This mutation results in an unstable phenylalanine hydroxylase (PAH) protein completely devoid of enzymatic activity well correlated with the severe form of the disease exhibited by the homozygous patients. PMID:9600453

De Lucca, M; Pérez, B; Desviat, L R; Ugarte, M

1998-01-01

128

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

PubMed

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

2013-03-01

129

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

E-print Network

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

Hurtado, Nuri; Torres, Julio

2014-01-01

130

New advances in molecular epizootiology of canine hematic protozoa from Venezuela, Thailand and Spain.  

PubMed

The prevalence of hematozoan infections (Hepatozoon canis and Babesia sp., particularly Babesia canis vogeli) in canids from Venezuela, Thailand and Spain was studied by amplification and sequencing of the 18S rRNA gene. H. canis infections caused simultaneously by two different isolates were confirmed by RFLP analysis in samples from all the geographic regions studied. In Venezuela, blood samples from 134 dogs were surveyed. Babesia infections were found in 2.24% of the dogs. Comparison of sequences of the 18S rRNA gene indicated that protozoan isolates were genetically identical to B. canis vogeli from Japan and Brazil. H. canis infected 44.77 per cent of the dogs. A representative sample of Venezuelan H. canis isolates (21.6% of PCR-positives) was sequenced. Many of them showed 18S rRNA gene sequences identical to H. canis Spain 2, albeit two less frequent genotypes were found in the sample studied. In Thailand, 20 dogs were analyzed. No infections caused by Babesia were diagnosed, whereas 30 per cent of the dogs were positive to hematozoan infection. Two protozoa isolates showing 99.7-100% identity to H. canis Spain 2 were found. In Spain, 250 dogs were studied. B. canis vogeli infected 0.01% of the animals. The sequence of the 18S rRNA gene in Spanish isolates of this protozoa was closely related to those previously deposited in GenBank (> 99% identity). Finally, 20 red foxes were screened for hematozoans employing semi-nested PCR and primers designed to detect Babesia/Theileria. Fifty percent of the foxes were positive to Theileria annae. In addition, it was found that the PCR assay was able as well to detect Hepatozoon infections. Thirty five percent of the foxes were infected with two different H. canis isolates showing 99.8-100% identity to Curupira 1 from Brazil. PMID:17088022

Criado-Fornelio, A; Rey-Valeiron, C; Buling, A; Barba-Carretero, J C; Jefferies, R; Irwin, P

2007-03-31

131

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. PMID:24806452

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

2014-01-01

132

Toxoplasma gondii infections in chickens from Venezuela: isolation, tissue distribution, and molecular characterization.  

PubMed

The prevalence of Toxoplasma gondii, in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 46 free-range chickens (Gallus domesticus) from Venezuela was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 16 (32%) chickens with titers of 1:5 in 1, 1:10 in 2, 1:40 in 2, 1:80 in 2, 1:160 in 2, 1:320 in 3, 1: 640 in 2, and 1:1,280 or higher in 2. Hearts, pectoral muscles, and brains of 13 chickens with MAT titers of 1:40 or more were bioassayed individually in mice. Tissues of each of 3 chickens with titers of 1:5 or 1:10 were pooled and bioassayed in mice. Tissues from the remaining 30 seronegative chickens were pooled and fed to 1 T. gondii-free cat. Feces of the cat were examined for oocysts; it did not shed oocysts. Toxoplasma gondii was isolated from 12 of 13 chickens with MAT titers of 1:40 or more. Toxoplasma gondii was isolated from pooled tissues of 1 of 2 chickens with titers of 1:10. Eight of these 13 isolates were virulent for mice. Genotyping of 13 of these isolates using the SAG2 locus indicated that 10 were type III, and 3 were type II. Phenotypically and genetically these isolates were different from T. gondii isolates from North America and Brazil. This is the first report of isolation of T. gondii from chickens from Venezuela. PMID:16539013

Dubey, J P; Lenhart, A; Castillo, C E; Alvarez, L; Marcet, P; Sreekumar, C; Lehmann, T

2005-12-01

133

[Homocysteinemia and its relationship with the methylentetrahydrofolate reductase polymorphism in various ethnic groups from western Venezuela].  

PubMed

The prevalence of hyperhomocysteinemia and C677T MTHFR polymorphism was studied in various ethnic groups from Western Venezuela (60 Wayuu Indians, 42 italian immigrants and 77 Venezuelan mestizos) in relation with the prevalence of hyperhomocysteinemia and the C677T MTHFR polymorphism. Homocysteinemia was determined by polarized fluorescence immunoassay in an IMX system, serum folate was measured by radioimmunoanalysis and the MTHFR genotype was determined by PCR and restriction analysis. Hyperhomocysteinemia was defined as a value over 2 SD above the mean value for normal MTHFR (CC677) in each group. The prevalence of MTHFR variants (C677T and 677TT) was elevated in all ethnic groups (78% among the wayuu, 76% among Italians and 63% among mestizos) with a significant association between the concentrations of homocysteine and the levels of serum folate among the wayuu (p < 0.0001) and the mestizos (p < 0.001) only. Hyperhomocysteinemia was associated with MTHFR variants in 23% of the wayuu (OR: 6.17, CI 95: 0.74-51.36), 9.5% of the Italians (OR: 0.93, CI 95: 0.085-10.10) and 20.7 of the Venezuelans mestizos (OR: 5.2, CI 95: 1.08-24.90, p > 0.03). There was no relationship between hyperhomocysteinemia and folate deficiency in any of the groups studied. In conclusion, despite a high prevalence of C677T MTHFR variants in these ethnic groups of western Venezuela, the lack of no evidence of hyperhomocysteinemia combined with folate deficiency may imply that the nutritional status of these groups plays an important role in the control of hyperhomocysteinemia as a risk factor for cardiovascular disease. PMID:16353542

Vizcaíno, Gilberto; Diez-Ewald, María; Herrmann, Falko H; Schuster, Gudrun; Torres-Guerra, Enrique; Arteaga-Vizcaíno, Melvis

2005-12-01

134

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

SciTech Connect

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

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

1993-02-01

135

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

PubMed

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

Allor, D J

1984-01-01

136

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

PubMed

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

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

2014-06-01

137

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

PubMed

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

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

2001-01-01

138

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

E-print Network

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

Rodriguez Navas, Humberto José

1983-01-01

139

REDES DE VIGILANCIA SISMICA Y VIGILANCIA DE TSUNAMIS Seismic and tsunami monitoring networks  

Microsoft Academic Search

The impact of the natural phenomena on the world-wide population is every more important due to the growth of the population; in addition this one is concentrated in coastal zones, so the tsunami risk in- creases. In the Pacific ring of fire they operate international, national and regional tsunami alert sys- tems. In this chapter the evolution and the operation

Sara Figueras Vila

140

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

PubMed

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

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

2005-10-01

141

Changes Associated with Field-Scale Demonstration in a Steam-Stimulated Crude Oil from the Lagunillas Oilfield (Lake Maracaibo, Venezuela)  

Microsoft Academic Search

Cyclic steam injection with alkali is currently very commonly used to improve heavy-crude oil production in Venezuela. This work is an analysis of oil-associated water and crude samples from LL-2670 well in the Lagunillas oilfield at Lake Maracaibo (northwestern Venezuela). The aim of this research is to analyze the organic acids thus generated and evaluate chemistry changes in the saturated

M. E. Hernández; E. Manrique; M. Martínez; G. Márquez

2010-01-01

142

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

2007-01-01

143

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

2008-01-01

144

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

Microsoft Academic Search

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

Yunping Xu; Rudolf Jaffé

2008-01-01

145

COMPARACIÓN DE MÉTODOS PARA EL ANÁLISIS DE MERCURIO EN SUELOS PROCEDENTES DE EL CALLAO, ESTADO BOLÍVAR, VENEZUELA  

Microsoft Academic Search

SUMMARY Mercury levels in soil samples from El Callao, Bolívar State, Venezuela, were determined by mineralization in aqua regia followed by cold vapor-atomic absorption spectrometry (CVAAS), and by direct determination on solid matrix by pyrolisis and preconcentration using an automatic mercury analyzer AMA-254 (AMA). Hg concentration in samples were in the range of 0.05 to 17.31mg\\/kg for CVAAS and of

Armando Carrasquero Durán; Melitón Adams

146

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

Microsoft Academic Search

Temporal variability of Black Band Disease (BBD) prevalence, incidence, recurrence, recovery and virulence was estimated in\\u000a a Diploria strigosa population from an upwelling zone of Venezuela, for 1 year between August 2004 and August 2005. The sampling spanned both\\u000a upwelling and non-upwelling seasons, and included three samplings, roughly 60 days apart, within each season. The negative\\u000a effects of BBD epizootiology in the

S. Rodríguez; A. Cróquer

2008-01-01

147

First occurrence of Paleoproterozoic oceanic plateau in the Guiana Shield: The gold-bearing El Callao Formation, Venezuela  

Microsoft Academic Search

The El Callao Formation is part of the Guasipati-El Callao Greenstone Belt, located in the northernmost part of the Guiana Shield, Venezuela. It consists of volcanic rocks, which have been analyzed for major and trace elements, REE concentrations and Sr–Nd isotopic composition. Based on these data, they have been characterized as Fe-rich tholeiitic basalts. On a primitive mantle-normalized diagram, all

Germán Velásquez; Didier Béziat; Stefano Salvi; Tommaso Tosiani; Pierre Debat

2011-01-01

148

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

USGS Publications Warehouse

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

Mendoza, C.

2000-01-01

149

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)

1996-08-01

150

[Epidemiology of sexually transmitted diseases in the mine area of Las Claritas, Bolivar State, Venezuela].  

PubMed

The primordial objective of this study was to carry out an epidemiological analysis of sexually transmitted diseases (STD) in terms of sensed morbidity and real morbidity in the mining region of "Las Claritas", Bolivar State, Venezuela, during the third trimester of 1998. The epidemiological characteristics of time, people and place are interlaced, giving a relationship included within the Epidemiological Triad, that represents this work's conceptual framework; defining both, the determinant and the conditioning factors of the presence of STDs in the zone. The clinical interrogatory was partially steered towards the participant's sensed morbidity. A mostly feminine population is described (65%), with a low scholarly level in the general population and a high index of foreigners among the evaluated patients; with 48.72% of stable unions in the interviewees. From 166 evaluated patients, 27.70% referred to have had some STD episode, being syphilis and blenorrhagia the most frequently reported. In the survey, there was a general hush concerning the presence of STDs; but, key informants such as the medicine retailers, revealed a higher presence of these diseases, which are wrongly treated by automedication. These are important results, since they let opened a space for the epidemiological evaluation in the zone, in the various health, sanitary, environmental and social aspects and mainly, by the individual's quality of life expectations. PMID:10961044

González-O, N; Rodríguez-Acosta, A

2000-06-01

151

Seismic hazard analysis of Western Venezuela methodology and data collection process  

SciTech Connect

The purpose of this project, initiated by INTEVEP is to develop a seismic hazard characterization for the region of the Lake Maracaibo basin in Western Venezuela (WV) with an emphasis at the sites of dikes built on the eastern side of the lake. One task of the project was to assess the seismicity of this region and to describe it in a form which can be used as input to a seismic hazard analysis. The seismic parameters of interests were seismo-tectonic zonation, distribution of earthquake magnitudes, and the largest earthquake, i.e., upper magnitude cutoff. Because it is difficult, or perhaps impossible, to precisely quantify such seismic parameters using only the sparse historical record, expert judgment is crucial. Thus two panels of experts were assembled, to supplement the lack of opinions in the possible models of zonation, seismicity, (S-panel) and ground motion attenuation (G-panel). In addition to the ground motion models described in the ground motion questionnaire handed to the G-panel experts, we performed some analysis, at LLNL, to develop a new breed of models where the parameter of interest is now the number of cycles of a given fraction of the peak ground acceleration, as a function of magnitude and distance from the source of an earthquake, rather than the peak ground acceleration (PGA) as a function of magnitude and distance. 20 refs.

Savy, J.

1988-06-01

152

Structural framework evolution and timing of oil accumulations, traditional areas, Barinas Subbasin, western Venezuela  

SciTech Connect

A 3D seismic survey is used in the definition of the tectonic and stratigraphic evolution, and timing of oil generation and migration in the traditional producing areas of the Barinas Subbasin of western Venezuela. The database consisted of an 885-km{sup 2} seismic survey, calibrated with core, sidewall and ditch sample analyses from Cretaceous and Tertiary sequences. Seismic to well data calibration was achieved through time-depth conversions, based on synthetic seismograms. Two approaches were followed in the construction of the synthetic seismograms. For wells with available sonic and density curves, synthetic seismograms were constructed directly through a commercial software. For wells with no sonic or density curves available, the Barinas-adapted versions of Faust`s and Gardner`s equations were used to construct synthetic seismograms from the deep resistivity curves. In both cases, excellent seismic-well log correlations were achieved, even in the more complex structures. Flattenings at different seismic reflectors were used to determine the evolution of stratigraphic and tectonic features. Onlaps, downlaps and toplaps are described in the seismic, and their relations with the tectonic and stratigraphic evolution were interpreted. Two major tectonic regimes were identified. The first regime is that of a Cretaceous marine shelf passive margin. The second one corresponds to the formation and filling of two Tertiary foreland basins. Present structures were already formed when the main episodes of oil generation and migration occurred.

Daal, J.; Salas, J.; Lopez, M.; Martinez, G.; Marquez, A. [Corpoven, Pto. La Cruz (Venezuela); Dunham, J.B. [Unocal Co., Sugar Land, TX (United States)

1996-08-01

153

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

USGS Publications Warehouse

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

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

1998-01-01

154

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.

2006-01-01

155

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. PMID:23579803

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

2013-01-01

156

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

PubMed

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

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

2007-01-01

157

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

PubMed

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

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

2012-09-01

158

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

SciTech Connect

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

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

1993-02-01

159

A new rabbit species (Sylvilagus, Mammalia: Leporidae) from the lowlands of Venezuela.  

PubMed

A new species of Venezuelan rabbit of the genus Sylvilagus from Fundo Millano (08 degrees 46'N and 69 degrees 56'W) and Chorrosco Bajo (08 degrees 05'N and 69 degrees 18'W), between 190 and 120 masl, state of Barinas, is described based on: 1. Body and skull measurements. 2. Coloration patterns of the pelage. 3. Arrangement and length of the color hair bands of dorsal, lateral, ventral nuchal, and gular patches. Body and cranial measurements, and some color patterns of the new species, Sylvilagus varynaensis, were compared with those of the closest relative groups such as S. brasiliensis (from Venezuela and Brazil), S. b. meridensis from the Venezuelan paramos, and three of the most representative groups of S. floridanus (S. f. continentis, S. f. orinoci, and S. f. valenciae). Most of the values recorded for these parameters were significantly higher for the new species (P < 0.005; Student "t" test). Cluster and principal components analysis of the data recorded for cranial characteristics indicated that S. varynaensis is the largest and darkest of the known Venezuelan rabbits, with a broader elongated skull and a different arrangement of the color hair bands. PMID:11795167

Durant, P; Guevara, M A

2001-03-01

160

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

PubMed

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

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

2013-03-01

161

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

PubMed

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

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

2009-02-01

162

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

PubMed

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

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

2005-09-01

163

Huntington disease-like 2 (HDL2) in Venezuela: frequency and ethnic origin.  

PubMed

Huntington disease (HD) phenotypes without a HTT mutation are known as HD-like (HDL) syndromes and are caused by mutations in other loci. HDL2, almost indistinguishable from HD, is due to expansions in the Junctophilin 3 locus (JPH3) with a worldwide Sub-Saharan ethnic origin. Sixteen independent patients with involuntary movements, psychiatric disturbances and ataxia not having a HTT mutation were searched for loci PRNP (prion protein, HDL1), JPH3 (HDL2), ATN1 (dentatorubral-pallidoluysian atrophy), ATX2 (spinocerebellar ataxia 2) ATXN3 (spinocerebellar ataxia 3), and TBP (spinocerebellar ataxia 17=HDL4). Markers Duffy, Kell, Diego, D9S1120, plus six JPH3 intragenic single-nucleotide polymorphisms were tested to ascertain ethnic origin. Four unrelated choreic patients had an expanded allele at JPH3. Three of them carried the African marker Duffy null. All four families carried with the mutation the same haplotype most frequent in African populations; Amerindian alleles D9D1120*9 and Diego A; or Kell allele K were absent. HDL2 in Venezuela had a low, but higher relative frequency (2.6%) than that in other Caucasoid populations. It should be searched first in choreic patients not having HTT mutations. The most likely remote ethnic origin for all detected families was African. PMID:22971727

Paradisi, Irene; Ikonomu, Vassiliki; Arias, Sergio

2013-01-01

164

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

SciTech Connect

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

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

1993-02-01

165

Paleogeographic considerations of the Barbacoas Platform western border during Paleocene-Middle Eocene, Trujillo State, Venezuela  

SciTech Connect

Stratigraphic and sedimentological field information of the Chejende-Cuicas area, and subsurface well data (Butaque-1S) have been integrated to analyze the paleogeographic evolution of Barbacoas Platform. Both localities are in the Trujillo state, western Venezuela and they are 18 km apart. A relatively narrow continental platform during Paleocene times can be inferred from the existence of Paleocene rocks of the Rancheria Formation, deposited in outer and middle neritic environments. This formation probably grades laterally towards the east and northeast, into the Trujillo Formation (Paleocene-early Eocene), which was deposited in a middle to upper bathyal environment in turbiditic conditions. Paleocene units grade upwards into the Misoa Formation, deposited in deltaic to coastal marine environments. This suggests a regressive progradation over slope and platform during early to early middle Eocene times. Eocene sedimentation ends with the transgressive Caus and Pauji formations, typical of upper bathyal to outer neritic conditions. Low sedimentation and subsidence rates in the platform in the Chejende area is inferred by the marked difference between Rancheria and Misoa formation thicknesses in this area (95 m and 40 m) and the Butaque-S well (520 and 175 m).

Muller, K. (Maraven S.A., Caracas (Venezuela)); Falcon, R. (Universidad Central de Venezuela, Caracas (Venezuela))

1993-02-01

166

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

SciTech Connect

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

Giffuni, G. (INTEVEP, S.A., Caracas (Venezuela))

1991-03-01

167

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

PubMed

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

2011-09-01

168

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

NASA Technical Reports Server (NTRS)

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

Albrizzio, C.

1974-01-01

169

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

PubMed

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

Mahmood, Qamar; Muntaner, Carles

2013-03-01

170

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

SciTech Connect

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

Daal, J.; Martinez, G.; Salas, J. (Unocal Corp., Sugar Land, TX (United States)) (and others)

1996-01-01

171

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.

2007-05-01

172

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

PubMed Central

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

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

2006-01-01

173

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

2013-09-01

174

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

PubMed

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

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

2011-12-01

175

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))

1991-03-01

176

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

PubMed Central

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

2012-01-01

177

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. PMID:11344155

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

2001-01-01

178

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

PubMed

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

Leython, Sirli; Jáuregui, Damelis

2008-09-01

179

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

USGS Publications Warehouse

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

Woodman, N.

2002-01-01

180

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

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

181

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.

2007-05-01

182

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

183

New insights into the tectonic evolution of the Boconó Fault, Mérida Andes, Venezuela  

NASA Astrophysics Data System (ADS)

The Boconó fault is a major right-lateral strike-slip fault that cuts along strike the Mérida Andes in Venezuela. The uplift of this mountain range started in the Miocene as a consequence of the relative oblique convergence between two lithospheric units named the Maracaibo block to the northwest and the Guyana shield to the southeast. Deformation in the Mérida Andes is partitioned between a strike-slip component along the Boconó fault and shortening perpendicular to the belt. Distinctive features define the Boconó fault: it is shifted southward relative to the chain axis and it does not have a continuous and linear trace but is composed of several fault segments of different orientations striking N35°E to N65°E. Quaternary fault strike-slip motion has been evidenced by various independent studies. However, onset of the strike-slip motion, fault offset and geometry at depth remains a matter of debate. Our work, based on morphostructural analyses of satellite and digital elevation model imagery, provides new data on both the geometry and the tectonic evolution of this major structure. We argue that the Boconó fault affects only the upper crust and connects at depth to a décollement. Consequently, it can not be considered as a plate boundary. The Boconó fault does however form the boundary between two different tectonic areas in the central part of the Mérida Andes as revealed by the earthquake focal mechanisms. South of the Boconó fault, the focal mechanisms are mainly compressional and reverse oblique-slip in agreement with NW SE shortening in the foothills. North of the Boconó fault, extensional and strike-slip deformation dominates. Microtectonic measurements collected in the central part of the Boconó fault are characterized by polyphased tectonics. The dextral shearing along the fault is superimposed to reverse oblique-slip to reverse motion, showing that initiation of transcurrent movement is more likely to have occurred after a certain amount of shortening. The present day strain partitioning along the Mérida Andes seems to be younger than the rise of the chain and coeval with the initiation of right-lateral shearing along the Boconó fault, which would have then initiated in the Pliocene. The Mérida Andes can be therefore considered as a case study of the kinematic evolution of a major strike-slip fault.

Backé, G.

2006-12-01

184

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

2000-01-01

185

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

PubMed

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

2010-06-01

186

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

NASA Astrophysics Data System (ADS)

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

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

2009-11-01

187

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.

1992-02-01

188

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

189

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

PubMed

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

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

2014-11-01

190

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

PubMed

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

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

2014-12-15

191

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

PubMed Central

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

Labrador, Indira

2014-01-01

192

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. PMID:22768004

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

2012-01-01

193

VIABILITY AND ACTIVIVITY OF THE LACTIC BACTERIA (Streptococcus salivarius ssp thermophilus and Lactobacillus delbrueckii ssp bulgaricus) OF YOGURT MADE IN VENEZUELA  

Microsoft Academic Search

National and international legislations have agreed that the population of lactic bacteria in yogurt must be viable and not less than 10 ufc\\/g. In Venezuela, during last years, observations indicate that the number of viable cells in some commercial samples show high variations, as low levels. This research attempted to find the origin of this problem in the local industry.

Ana Graciela Briceño; Raúl Martínez; Karely García

194

Phractocephalus hemiliopterus (Pimelodidae, Siluriformes) from the upper Miocene Urumaco Formation, Venezuela: a further case of evolutionary stasis and local extinction among South American fishes  

Microsoft Academic Search

A fossil catfish skull from the upper Miocene Urumaco Formation of Falcon State, Venezuela is identified as Phractocephalus hemiliopterus (Pimelodidae), a living species of the large, lowland rivers east of the Andes. This fossil provides another example, in a growing list of cases, of a long and conservative evolutionary history for an advanced South American riverine fish. The phylogenetic position

John G. Lundberg; Omar J. Linares; Maria Esther Antonio; Pedro Nass

1988-01-01

195

Cylindrocarpon destructans VAR. destructans AND Neonectria discophora VAR. rubi ASSOCIATED WITH BLACK FOOT ROT ON BLACKBERRY (Rubus glaucus BENTH.) IN MÉRIDA, VENEZUELA  

Microsoft Academic Search

SUMMARY In a commercial blackberry (Rubus glaucus Benth.) field located at El Valle, Municipality Libertador, Mérida State, Venezuela, a black foot rot disease was detected in 1999. The causal agent was identified as Cylindrocarpon destructans var. destructans (teleo- morph=Neonectria radicicola var. radicicola). This pathogen attacks the roots and the crown, inducing die-back in canes. Symptoms simi- lar to those observed

Luis Cedeño; Chrystian Carrero; Kleyra Quintero; Henry Pino; Wilmer Espinoza

2004-01-01

196

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

2006-01-01

197

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

Microsoft Academic Search

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

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

2007-01-01

198

Estimación de la profundidad de trabajo de anzuelos de un palangre atunero prototipo de la flota de altura de Isla de Margarita (Venezuela)  

Microsoft Academic Search

Based on two fishing trips carried out in the Caribbean Sea in May 1997 and in June 1998, on board of deep sea tuna longline fishing boat, from Chacachacare, Margarita Island, Venezuela, the shape and tension of the longline were determined under working conditions, and the operational depth of hooks were estimated by mechanical simulation method. Lineal scale factor for

Ernesto Trujillo; Guillermo Martínez

2003-01-01

199

[Comparative analysis between the circumoval precipitin test and ELISA with raw antigens for the diagnosis of schistosomiasis in Venezuela].  

PubMed

Schistosomiasis has special characteristics in Venezuela, since the majority of the infected population is asymptomatic and the elimination of eggs is very low, difficulting in this way parasitologic diagnosis. It is thus necessary to develop sensitive and specific immunologic methods to be applied in field surveys. The present study compares two serologic tests for Schistosomiasis, the enzyme linked immunosorbent assay (ELISA) with eggs (SEA) and adult (AWA) antigens and the traditional circumoval precipitation test (COPT). Sensitivity and specificity of the test were performed being 100% and 92% in COPT, 79% and 71% in ELISA-SEA and 71% and 91% in ELISA-AWA respectively. Advantages and disadvantages of each test are discussed. PMID:1843941

Spencer, L; Alarcón de Noya, B; Noya, O; Masroua, G

1991-01-01

200

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.

1980-01-01

201

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

PubMed

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

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

2009-01-01

202

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

SciTech Connect

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

Olmore, S.D. (S.D. Olmore Associates Inc., Golden, CO (United States)); Garcia, A. (CVG-Tecnica Minera C.A., Puerto Ordaz (Venezuela)); Antonia, S.C. (Lagoven S.A., Caracas (Venezuela))

1993-02-01

203

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. PMID:24885094

2014-01-01

204

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

2014-07-01

205

Importance of Bottom Nephelolid Layers on the Transport and Delivery of Ssediment to the Eastern Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Due to their high topographic relief and susceptibility to erosion, mountainous coastal rivers may potentially deliver high sediment and organic matter loads to continental margins. Three small mountainous rivers (Manzanares, Neveri and Unare) that empty onto the shelf of the eastern Cariaco Basin (Venezuela) were examined during the rainy season in September 2003 and 2006 under the framework of the CARIACO (CArbon Retention In A Colored Ocean) Time-Series Project. Optical transmissometer measurements were coupled with particulate organic matter (POM) samples collected in the water column and near the bottom. Suspended sediments entering the basin sink rapidly to the bottom close to the mouth of the rivers (< 10 km). Over the shelf, river sediments dispersed via bottom nepheloid layers (BNL) up to 50 km from the source, reaching the 100m isobath. BNL were observed near the mouths of the three rivers, varying in thickness from 2 to 20 m, with the thickest and most extended BNL observed off the Unare River. BNL particle concentrations were 2-60% higher than water column values. Most of the BNL were lower in particulate organic carbon (POC), nitrogen (PON) and phosphate (POP) (~85 mg C m-3, ~9.6 mg N m-3, ~ 0.8 mg P m-3, respectively), compared to measurements in the overlying water column (~100 mg C m-3, ~10.7 mg N m-3, ~ 0.92 mg P m-3, respectively), suggesting that BNL are not a primary mechanism for delivering terrigenous POM to the deeper anoxic waters of the Cariaco Basin during the rainy season. Nonetheless, terrigenous sediments originating in the Cordillera de la Costa (Coastal Mountain Range) of Venezuela are found in the deep sediments of Cariaco Basin, and thus may serve as important components of mineral ballast that acts to transport POC from surface waters to depth. BNL also represent a potential, transitory source of iron to the suboxic zone of the Cariaco Basin.

Lorenzoni, L.; Muller-Karger, F. E.; Thunell, R. C.; Tappa, E.; Benitez-Nelson, C.; Hollander, D.; Varela, R.; Astor, Y.; Hu, C.

2007-12-01

206

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

PubMed Central

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

2014-01-01

207

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

PubMed Central

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

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

2014-01-01

208

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

NASA Astrophysics Data System (ADS)

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

Malavé, Gustavo; SuáRez, Gerardo

1995-06-01

209

Especiación de metales pesados en la fracción disuelta de las aguas superficiales de la cuenca baja y la pluma del Río Manzanares, Estado Sucre, Venezuela Heavy metal speciation in the surface water dissolved fraction of the low watershed and plume of the Manzanares River, Sucre State, Venezuela  

Microsoft Academic Search

This paper reports on the speciation of heavy metals (Cd, Pb, Cr, Cu, Ni, Mn, Fe, and Zn) in the surface water dissolved fraction of the low basin and plume of the Manzanares River, in the state of Sucre, Venezuela, based on data taken at 22 stations from July 1996 to June 1997. The total metal concentrations in the dissolved

G Martínez; W Senior; A Márquez; Estado Sucre

2006-01-01

210

A nested model of the Cariaco Basin (Venezuela): description of the basin’s interior hydrography and interactions with the open ocean  

Microsoft Academic Search

A high-resolution (1\\/60°), three-dimensional numerical circulation model of the Cariaco Basin (Venezuela) is constructed by\\u000a nesting the Regional Ocean Modeling System (ROMS) in the 1\\/12° global Hybrid Coordinate Ocean Model (HYCOM). A new bathymetry,\\u000a computed by merging DBDB2 data and in situ depth measurements using optimal interpolation, is described. This new bathymetry\\u000a corrects the depth of the channels that connect

Aida Alvera-Azcárate; Alexander Barth; Robert H. Weisberg

2009-01-01

211

Hypsilara royi gen. n. and sp. n. (Coleoptera, Elmidae, Larainae) from Southern Venezuela, with a revised key to Larainae of the Western Hemisphere  

E-print Network

and ink using a camera lucida attached to a Olympus SZX7 microscope. Images were edited in Adobe Illustrator and Adobe Photoshop. Specimens were depos- ited in the following collections: MIZA Museo del Instituto de Zoología Agrícola Maracay, Venezuela... promi- nent and without teeth (Figs 15, 16). Hind wing lightly pigmented. Radial bar strong; radio-medial loop and radial cross vein r4 distinct; radial cell incomplete; medial fleck absent; media posterior MP 1+2 strong, distinct; medial spur long...

Maier, Crystal A.; Spangler, Paul J.

2011-07-07

212

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

2010-01-01

213

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

ERIC Educational Resources Information Center

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

Drallny, Ines

1987-01-01

214

La Interpretacion Consecutiva y la Ensenanza Avanzada de Idiomas (Delayed Interpretation and Advanced Language Teaching)  

ERIC Educational Resources Information Center

Discusses the teaching of interpretation. The importance of delayed interpretation, as opposed to simultaneous interpretation, is stressed, because of the emphasis on semantic meaning. (Text is in Spanish.) (NCR)

Bradley, D.

1977-01-01

215

Approaches to identifying reservoir heterogeneity and reserve growth opportunities from subsurface data: The Oficina Formation, Budare field, Venezuela  

SciTech Connect

We applied an integrated geologic, geophysical, and engineering approach devised to identify heterogeneities in the subsurface that might lead to reserve growth opportunities in our analysis of the Oficina Formation at Budare field, Venezuela. The approach involves 4 key steps: (1) Determine geologic reservoir architecture; (2) Investigate trends in reservoir fluid flow; (3) Integrate fluid flow trends with reservoir architecture; and (4) Estimate original oil-in-place, residual oil saturation, and remaining mobile oil, to identify opportunities for reserve growth. There are three main oil-producing reservoirs in the Oficina Formation that were deposited in a bed-load fluvial system, an incised valley-fill, and a barrier-strandplain system. Reservoir continuity is complex because, in addition to lateral facies variability, the major Oficina depositional systems were internally subdivided by high-frequency stratigraphic surfaces. These surfaces define times of intermittent lacustrine and marine flooding events that punctuated the fluvial and marginal marine sedimentation, respectively. Syn and post depositional faulting further disrupted reservoir continuity. Trends in fluid flow established from initial fluid levels, response to recompletion workovers, and pressure depletion data demonstrated barriers to lateral and vertical fluid flow caused by a combination of reservoir facies pinchout, flooding shale markers, and the faults. Considerable reserve growth potential exists at Budare field because the reservoir units are highly compartment by the depositional heterogeneity and structural complexity. Numerous reserve growth opportunities were identified in attics updip of existing production, in untapped or incompletely drained compartments, and in field extensions.

Hamilton, D.S.; Raeuchle, S.K.; Holtz, M.H. [Bureau of Economic Geology, Austin, TX (United States)] [and others

1997-08-01

216

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

PubMed

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

2014-06-01

217

New insights in the global cycle of acetonitrile: release from theocean and dry deposition in the tropical savanna of Venezuela  

NASA Astrophysics Data System (ADS)

Using the proton transfer reaction mass spectrometry (PTR-MS) technique, acetonitrile was measured during the wet season in a Venezuelan woodland savanna. The site was located downwind of the Caribbean Sea and no biomass burning events were observed in the region. High boundary layer concentrations of 211±36pmol/mol (median, ±standard deviation) were observed during daytime in the well mixed boundary layer, which is about 60pmol/mol above background concentrations recently measured over the Mediterranean Sea and the Pacific Ocean. Most likely acetonitrile is released from the warm waters of the Caribbean Sea thereby enhancing mixing ratios over Venezuela. Acetonitrile concentrations will probably still be much higher in biomass burning plumes, however, the general suitability of acetonitrile as a biomass burning marker should be treated with care. During nights, acetonitrile dropped to levels typically around 120pmol/mol, which is consistent with a dry deposition velocity of {sim}0.14cm/s when a nocturnal boundary layer height of 100m is assumed.

Sanhueza, E.; Holzinger, R.; Kleiss, B.; Donoso, L.; Crutzen, P. J.

2004-02-01

218

[The phorophyte occupation patterns by vascular epiphyte species in the High Orinoco tropical humid forest, Amazonas State, Venezuela].  

PubMed

By international agreement (Austria-Venezuela), an experimental area was selected for canopy ecology studies. A tower crane was installed that allows direct access to the canopy of 1.5 ha area of the forest. This is a quantitative study of the phorophyte occupation patterns by vascular epiphyte species in an Amazon tropical humid forest. The forest of Surumoni consists roughly of four arboreal strata, i.e., emergent (conspicuous), superior, middle and lower. The largest proportion of trees occurs in the lower diametric classes (smaller DBH), and the total distribution approaches an "inverted J" curve. The most abundant tree species in the three strata is Goupia glabra (Celastraceae); making this forest a case where a single arboreal species dominants. Mean of epiphyte individuals per occupied phorophyte is too variable, depending on phorophyte species and showing no correlation with occupied tree percentage. The species Eschweleira parviflora (Lecythidaceae) represented in the study area by a single individual of the superior stratum with high density of vascular epiphytes, indicates that this support species is particularly favorable for the establishment epiphytic flora. PMID:11915448

Hernández-Rosas, J

2001-01-01

219

First description of the breeding biology and natural history of the ochre-breasted brush finch atlapetes semirufus in venezuela  

USGS Publications Warehouse

We provide the first description of the eggs, breeding biology, and natural history of the Ochre-breasted Brush Finch (Atlapetes semirufus). We found 37 nests over four breeding seasons (2004-2007) in Yacamb?? National Park, Venezuela. Nesting activity started in late April and continued until early June suggesting single-brooded behavior despite a typical tropical clutch size of two eggs (x?? = 1.89) that were laid on consecutive days. Egg mass averaged 3.38 g and 11.6% of adult female mass. The incubation and nestling periods averaged 14.9 and 10.5 days, respectively. Only females incubated and the percent time they spent incubating did not change between early and late incubation. Females brooded 42.7% of the time when nestlings were 2 days of age and 20.5% when 9 days of age. Both parents provisioned young at a low rate (3.9 trips/hr) and nestling growth rate (k = 0.45) was also slow. Nest predation rates were relatively high with daily mortality rates of 0.058 and 0.067 during incubation and nestling stages, respectively.

Biancucci, L.; Martin, T. E.

2008-01-01

220

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.

2013-05-01

221

[Viability and activity of the lactic bacteria (Streptococcus salivarius ssp thermophilus y Lactobacillus delbrueckii ssp bulgaricus) del yogurt en Venezuela].  

PubMed

National and international legislations have agreed that the population of lactic bacteria in yogurt must be viable and not less than 10(6) ufc/g. In Venezuela, during last years, observations indicate that the number of viable cells in some commercial samples show high variations, as low levels. This research attempted to find the origin of this problem in the local industry. For this purpose 105 commercial samples were analyzed during their shelf life and 32 samples of yogurt prepared in the laboratory following the flow diagram of the local industry. The different conditions of freeze dried lactic culture, were also analyzed. These samples were evaluated for viable cell count of lactic bacteria and possible variations of pH and acidity. The absence or low number of lactic bacteria detected in some commercial samples is due to the use of inadequate working cultures that show imbalanced proportions of the two microorganisms, besides a low count below 106 ufc/g. The succesive propagation and storage time of mother culture, and the overacidification of the product, produce subletal injury to the microbial cells of the yogurt starter culture. The data indicate that manufacturing practices significantly affect the survival of the lactic flora. PMID:11510428

Briceño, A G; Martínez, R; García, K

2001-01-01

222

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

2002-01-01

223

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)

1996-08-01

224

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

PubMed

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

2006-01-01

225

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. PMID:18646313

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

2012-01-01

226

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.

1993-02-01

227

Seroprevalence to bovine virus diarrhoea virus and other viruses of the bovine respiratory complex in Venezuela (Apure State).  

PubMed

Six hundred and fifteen serum samples obtained from cows in five districts of Apure State, Venezuela, were tested by ELISA for antibodies to bovine virus diarrhoea virus (BVDV). The same samples were also ELISA-tested for antibodies to bovine herpesvirus type 1 (BHV-1) and bovine respiratory syncytial virus (BRSV). Additionally, the haemagglutination-inhibition (HI) test was used for detecting antibodies to parainfluenza virus type 3 (PIV-3). Overall, seroprevalence to BVDV was 36+/-7% (SE); seroprevalence varied by district (19-42%). BHV-1 seroprevalence was 67+/-4%; variation by district was similar to that of BVDV. However, the first 80 serum samples tested by BHV-1 ELISA all had a strong background reaction with the control antigen. Therefore, these sera were adsorbed to a homogenate of non-infected bovine kidney cell line (MDBK) and retested by ELISA. The non-specific reactivity was significantly reduced (p<0.001 by Wilcoxon's signed-rank test). Compared to the virus-neutralisation (VN) test, the adsorbed BHV-1 ELISA showed 94% agreement and gave a kappa value of 0.84, indicating that the adsorption did not interfere with test accuracy. Seroprevalence against BRSV was 85+/-3%, and showed differences across districts. Most of the cows (94+/-2%) were seropositive to PIV-3, and there were no significant differences among districts. PMID:10530426

Obando, R C; Hidalgo, M; Merza, M; Montoya, A; Klingeborn, B; Moreno-López, J

1999-08-23

228

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

PubMed

The exploitation of new wilderness areas with crops is increasing and traditional crop substitution has been modified by new more productive crops. The results show the anthropogenic disturbance effect on the sandflies population and Leishmania transmission in endemic areas of Venezuela. Three agroecosystems with variable degrees of ecological disturbance, forest (conserved), cacao (fragmented), and orangery (disturbed), were selected. Four methods to sandfly capture were used; the specimens were identified and infected with Leishmania. Diversity, population structure, ANOVA, Tukey test, and simple correlation analysis were carried out. Shannon traps were able to capture 94.7% of the total sandflies, while CDC light traps, Sticky traps, and direct suction just captured 2.2%, 1.2%, and 0.9%, respectively. The results showed the effect of ecological disturbance degree on the composition of sandflies and population structure, revealing a dominance level increased but decreased on the diversity and richness of sandflies species in the greatest ecological disturbance area in relation to areas with less organic disturbance. Environments more disturbed cause adaptability of certain species such as Lutzomyia gomezi and Lutzomyia walkeri. These changes on the composition of sandflies population and structure emerging species could cause increasing of leishmaniasis transmission. PMID:24949018

Nieves, Elsa; Oraá, Luzmary; Rondón, Yorfer; Sánchez, Mireya; Sánchez, Yetsenia; Rojas, Masyelly; Rondón, Maritza; Rujano, Maria; González, Nestor; Cazorla, Dalmiro

2014-01-01

229

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

SciTech Connect

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

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

1993-02-01

230

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

PubMed

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

1999-01-01

231

Petrography and U-Pb Zircon Geochronology of Geological Units of the Mesa de Cocodite, Península de Paraguaná, Venezuela  

NASA Astrophysics Data System (ADS)

Several continental crust units crop out in The Mesa de Cocodite, central Paraguaná Peninsula, Northwestern Venezuela, including a newly mapped quartz-feldspar gneiss that intruded the El Amparo Pluton, a major low-graded metamorphic unit of Permian age. It is unconformably overlying by Late Jurassic phyllites of the Pueblo Nuevo Formation. All these units are cross-cut by narrow dykes. This contribution focuses on the petrography and LA-ICP-MS U-Pb zircon dating of the igneous units, with the aim of constraining magmatism and its tectonic significance in the area. The quartz-feldspar gneiss consists of albite, bluish-smoked quartz, muscovite-chlorite, epidote and zircon. The enclosing El Amparo Pluton is typically a coarse-grained and thick-banded metagranodiorite, containing andesine, quartz, hornblende, epidote, K-feldspar, biotite, chlorite, titanite and zircon. The younger dykes consist of fine-grained, porphyritic hornblende diorites that contain numerous hornblende phenocrysts. The main minerals are andesine, hornblende, quartz, and chlorite. Accessory minerals include zircon, epidote and opaques. A felsic gneiss xenolith collected from the dykes contain quartz, K-feldspar, chlorite, epidote, albite and zircon. Zircon population in the quartz-feldspar gneiss displays a discordia trend, ranging in age from 1050-750 Ma but mostly around 950-900 Ma, which may represent a peak high-grade metamorphism in the area. The El Amparo Pluton provides a concordant Permian age (271.3±6.5 Ma), which is comparable with previous reported U-Pb ages in titanite. Because the porphyry dykes cross-cut all the units in the area, they should be post-Late Jurassic in Age; however, all dated zircons from the dykes are in the range of 1200-750 Ma. The absence of younger ages can be attributed to either formation during a relatively low temperature magmatic event, which generated very narrow younger zircon rims only and thus undetectable with the technique used, or a completely lack of newly generated outer zones due to quick cooling. The emplacement age for the dykes may be early Cenozoic, as for similar basement rocks from the Gulf of Venezuela and the Guajira Peninsula. A felsic-gneiss xenolith enclosed in the dykes contains inherited Proterozoic zircons (1200-950 Ma) with rims of Permian age (270.2±4.1 Ma). Thus, the inherited older ages detected in the feldspar-gneiss unit, the later dykes, and the xenolith indicate the occurrence of Grenvillian crust in Northwestern South America. The Permian ages obtained in the Paraguaná Peninsula are similar to ages reported for the Mérida Andes, Santa Marta Massif, Perijá Range, Orchila Island, northern part of the Maracaibo Basin (Toas Island), northwestern Falcon Basin. Therefore, the Permian magmatic event may have been related to an active margin during the construction of Pangaea, caused by the subduction of oceanic crust under the northwestern corner of South America.

Mendi, D.; Baquero, M. L.; Oliveira, E. P.; Urbani, F.; Pinto, J.; Grande, S.; Valencia, V.

2013-05-01

232

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

SciTech Connect

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

Marcucci, E.; Soto, R.E.; Font, J.B. [Incostas, Caracas (Venezuela)

1996-12-01

233

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

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

234

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

PubMed Central

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

Moyersoen, Bernard; Weiss, Michael

2014-01-01

235

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

PubMed

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

Moyersoen, Bernard; Wei?, Michael

2014-01-01

236

Coupling of Sinking Biogenic Particulate Fluxes and Primary Production in the Euphotic Zone of the Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Only 1% of the organic matter produced in the upper ocean by photosynthesis reaches depths below 1500 m due to dissolution and microbial degradation. Recent work shows that the vertical flux of particulate organic carbon (POC) is strongly correlated with the settling flux of minerals like calcium carbonate, opal and lithogenic material. These act as ballast and also provide physical protection against degradation of POC. Results from the CARIACO (Carbon Retention in a Colored Ocean) time series program support this hypothesis. For over ten years, CARIACO has been studying the connections between primary production (PP) and the biogeochemical features of sinking particles in the Cariaco Basin, Venezuela, with moored sediment traps that collect settling matter at five depths between 125 and 1300 m on a bi-weekly basis. The geomorphology of the basin restricts deep water ventilation, leading to anoxia below 250 m. Although the Cariaco Basin exhibits strong seasonal production cycles related to wind-driven upwelling, the flux of biogenic matter at all depths below the oxic-anoxic interface is not significantly correlated to primary production. In order to understand the flux of particles in the upper 100 m of the water column, deployments of drifting sediment traps in the Cariaco Basin were carried out from March to July 2007, collecting settling material at 50 and 100 m. The hypothesis is that the flux of sinking material through the euphotic zone may be less affected by decomposition and dissolution than material reaching the deep moored traps. Initial results show significant differences in POC, PON and carbonate flux rates between 50 and 100 m. They also exhibit significant differences in the flux rates of these components between upwelling vs. relaxation periods, suggesting potential connections among seasonal changes in surface chlorophyll a concentrations, plankton community structure, and the vertical export of biogenic materials. We describe results from this research, including comparisons between shallow and deep sediment trap data.

Montes-Herrera, E.; Muller-Karger, F. E.; Thunell, R.; Hollander, D.; Astor, Y.; Varela, R.; Soto, I.; Lorenzoni, L.

2007-12-01

237

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

PubMed

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

Rodríguez-Olarte, Douglas; Barrios Gómez, Margenny

2014-09-01

238

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

PubMed

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

2009-09-01

239

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.

2001-12-01

240

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

PubMed

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

2010-09-01

241

An investigation of the probability of occurrence of dry periods during the rainy season in the grassy highlands of Western Venezuela  

E-print Network

of this thes1s. To Ing. R. Mart1nez of the "Vicerrectorado de Produccion Agricola, Un1versidad Nacional Experimental de los Llanos Occidentales, Ezequiel Zamora, " Guanare, Venezuela, for prov1ding me with the climatological data used in this invest1gation...- out my graduate plan; also for his friendship. To the Vice-President of the "Vicerrectorado de Produccion Agricola de la Universidad Nacional Experimental de los Llanos Occidentales, Ezequiel Zamora" in the State of Portuguesa, Dr. P. J. Urriola M...

Quintana Gomez, Ramon Alfonso

2012-06-07

242

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. PMID:21999170

2011-01-01

243

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

NASA Astrophysics Data System (ADS)

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

Guzman Espinal, Jose Ignacio

1999-11-01

244

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.

2011-12-01

245

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

PubMed

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

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

2012-09-01

246

Serological and molecular diagnosis of bovine viral diarrhoea virus and evidence of other viral infections in dairy calves with respiratory disease in Venezuela.  

PubMed

An investigation based on 2 studies was carried out to assess the involvement of bovine virus diarrhoea virus (BVDV), bovine herpesvirus type 1 (BHV-1), and bovine respiratory syncytial virus (BRSV) in calf respiratory disease in dairy farms in Venezuela. In the first study, 8 farms were selected and paired serum samples from 42 calves with respiratory disease were tested by ELISA for antibodies to the 3 viruses. Seroconversion to BVDV, BHV-1, and BRSV was found to 5, 2, and 6 farms out of the 8, respectively. The proportion of calves that showed seroconversion to BVDV, BHV-1, and BRSV were 19%, 14%, and 26%, respectively. In the second study, another farm having previous serological evidence of BVDV infection was selected. The decline of maternal antibodies against BVDV was monitored in 20 calves and the half-life of maternal antibodies was 34 +/- 12 days presumably indicating an early natural infection with BVDV. Furthermore, sera free of BVDV antibodies that were collected in studies 1 and 2 and were assayed for the presence of BVDV by nested RT-PCR. Two BVDV strains were detected and compared to those of ruminant and porcine pestiviruses. Both strains were assigned to subgroup Ib of type I BVDV. This investigation provides information on BVDV genotypes circulating in Venezuela and may contribute to the establishment of official control programmes against the viruses studied. PMID:10605142

Obando, C; Baule, C; Pedrique, C; Veracierta, C; Belák, S; Merza, M; Moreno-Lopez, J

1999-01-01

247

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. PMID:22476484

Ramirez, Nelson; Briceno, Herbert

2011-01-01

248

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.

2010-12-01

249

Plasma corticosterone levels of semipalmated sandpiper Calidris pusilla overwintering in a tropical coastal lagoon of northeastern Venezuela: effect of capture and handling.  

PubMed

Semipalmated sandpiper Calidris pusilla arrives on the coasts of Venezuela between the middle of August and early September, staying there until May when birds prepare for vernal migration. To investigate possible relationships between corticosterone levels and body mass changes during preparation for migration, we sampled birds during wintering (January) and vernal premigration (May) over 2 years. Body mass and fat increased significantly from wintering to vernal premigration in both years. Capture stress levels of corticosterone varied between 30 and 150 ng mL(-1), the highest being during wintering. These results strongly suggest that increase in body mass of C. pusilla during preparation for vernal migration in a tropical environment was promoted by a decreased corticosterone secretion response to stress. PMID:19456387

Mata, Astolfo; Marín, Gedio; Rodríguez, Jon Paul; Yuraí Guerrero, Hilda; Cardillo, Elizabeth

2009-04-01

250

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.

2013-10-01

251

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.

2013-05-01

252

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. PMID:20668711

Chacon, Jose

2010-01-01

253

CO{sub 2} emissions from developing countries: Better understanding the role of Energy in the long term. Volume 2, Argentina, Brazil, Mexico, and Venezuela  

SciTech Connect

Recent years have witnessed a growing recognition of the link between emissions of carbon dioxide (CO{sub 2}) and changes in the global climate. Of all anthropogenic activities, energy production and use generate the single largest portion of these greenhouse gases. Although developing countries currently account for a small share of global carbon emissions, their contribution is increasing rapidly. Due to the rapid expansion of energy demand in these nations, the developing world`s share in global modern energy use rose from 16 to 27 percent between 1970 and 1990. If the growth rates observed over the past 20 years persist energy demand in developing will surpass that in the countries of the Organization for Economic Cooperation and Development (OECD) early in the 21st century. The study seeks to examine the forces that galvanize the growth of energy use and carbon emissions, to assess the likely future levels of energy and CO{sub 2} in selected developing nations and to identify opportunities for restraining this growth. The purpose of this report is to provide the quantitative information needed to develop effective policy options, not to identify the options themselves. These individual studies were conducted fro Argentina, Brazil, Mexico and Venezuela in Latin America.

Ketoff, A.; Sathaye, J.; Goldman, N. [eds.

1991-07-01

254

New insights in the global cycle of acetonitrile: release from the ocean and dry deposition in the tropical savanna of Venezuela  

NASA Astrophysics Data System (ADS)

CUsing the proton transfer reaction mass spectrometry (PTR-MS) technique, acetonitrile was measured during the wet season in a Venezuelan woodland savanna. The site was located downwind of the Caribbean Sea and no biomass burning events were observed in the region. High boundary layer concentrations of 211 ±36 pmol/mol (median, ± standard deviation) were observed during daytime in the well mixed boundary layer, which is about 60 pmol/mol above background concentrations recently measured over the Mediterranean Sea and the Pacific Ocean. Most likely acetonitrile is released from the warm waters of the Caribbean Sea thereby enhancing mixing ratios over Venezuela. Acetonitrile concentrations will probably still be much higher in biomass burning plumes, however, the general suitability of acetonitrile as a biomass burning marker should be treated with care. During nights, acetonitrile dropped to levels typically around 120 pmol/mol, which is consistent with a dry deposition velocity of ~0.14 cm/s when a nocturnal boundary layer height of 100 m is assumed.

Sanhueza, E.; Holzinger, R.; Kleiss, B.; Donosos, L.; Crutzen, P. J.

2003-10-01

255

Analysis of the El Nin?o/La Nin?a-Southern Oscillation variability and malaria in the Estado Sucre, Venezuela.  

PubMed

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

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

2012-09-01

256

Coinfection with Three Ehrlichia Species in Dogs from Thailand and Venezuela with Emphasis on Consideration of 16S Ribosomal DNA Secondary Structure  

PubMed Central

As part of a larger study to investigate tick-borne infections in dogs from Thailand and Venezuela, documentation of coinfection with three Ehrlichia species in two dogs, one from each country, became the focus of the present study. Although neither dog had clinical signs attributable to ehrlichiosis, both dogs were anemic and neutropenic and the Thai dog was thrombocytopenic. Genus- and species-specific PCR targeting the 16S rRNA genes indicated that both dogs were coinfected with Ehrlichia canis, E. platys, and E. equi. To our knowledge, these results provide the first molecular documentation for the presence of E. equi in dogs from these countries. Using universal bacterial PCR primers, one nearly full-length 16S rRNA gene could be amplified from each dog. The sequences were identical to each other and almost identical to that of E. platys (AF156784), providing the first E. platys 16S ribosomal DNA (rDNA) sequences reported from these two geographically divergent countries. To determine whether these sequence differences allow differentiation between these two strains and other published 16S rDNA E. platys sequences, we performed a phylogenetic analysis of the rRNA, incorporating the consideration of secondary structure. PMID:11136754

Suksawat, Jiraporn; Pitulle, Christian; Arraga-Alvarado, Cruz; Madrigal, Karina; Hancock, Susan I.; Breitschwerdt, Edward B.

2001-01-01

257

Molecular architecture of DesV from Streptomyces venezuelae: a PLP-dependent transaminase involved in the biosynthesis of the unusual sugar desosamine.  

PubMed

Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found in certain macrolide antibiotics such as the commonly prescribed erythromycin. Six enzymes are required for its biosynthesis in Streptomyces venezuelae. The focus of this article is DesV, which catalyzes the PLP-dependent replacement of a 3-keto group with an amino functionality in the fifth step of the pathway. For this study the three-dimensional structures of both the internal aldimine and the ketimine intermediate with glutamate were determined to 2.05 A resolution. DesV is a homodimer with each subunit containing 12 alpha-helical regions and 12 beta-strands that together form three layers of sheet. The structure of the internal aldimine demonstrates that the PLP-cofactor is held in place by residues contributed from both subunits (Asp 164 and Gln 167 from Subunit I and Tyr 221 and Asn 235 from Subunit II). When the ketimine intermediate is present in the active site, the loop defined by Gln 225 to Ser 228 from Subunit II closes down upon the active site. The structure of DesV is similar to another sugar-modifying enzyme referred to as PseC. This enzyme is involved in the biosynthesis of pseudaminic acid, which is a sialic acid-like nonulosonate found in the flagellin of Helicobacter pylori. In the case of PseC, however, the amino group is transferred to the C-4 rather than the C-3 position. Details concerning the structural analysis of DesV and a comparison of its molecular architecture to that of PseC are presented. PMID:17456741

Burgie, E Sethe; Thoden, James B; Holden, Hazel M

2007-05-01

258

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. PMID:22958602

2011-01-01

259

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

260

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)

2008-07-28

261

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

PubMed

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

2012-07-01

262

Triatoma maculata, the Vector of Trypanosoma cruzi, in Venezuela. Phenotypic and Genotypic Variability as Potential Indicator of Vector Displacement into the Domestic Habitat  

PubMed Central

Triatoma maculata is a wild vector of Trypanosoma cruzi, the causative agent of Chagas disease; its incursion in the domestic habitat is scant. In order to establish the possible domestic habitat of T. maculata, we evaluated wing variability and polymorphism of genotypic markers in subpopulations of T. maculata that live in different habitats in Venezuela. As markers, we used the mtCyt b gene, previously apply to evaluate population genetic structure in triatomine species, and the ?-tubulin gene region, a marker employed to study genetic variability in Leishmania subgenera. Adults of T. maculata were captured in the period 2012–2013 at domestic, peridomestic (PD), and wild areas of towns in the Venezuelan states of Anzoátegui, Bolívar, Portuguesa, Monagas, Nueva Esparta, and Sucre. The phenotypic analysis was conducted through the determination of the isometric size and conformation of the left wing of each insect (492 individuals), using the MorphoJ program. Results reveal that insects of the domestic habitat showed significant reductions in wing size and variations in anatomical characteristics associated with flying, in relation to the PD and wild habitats. The largest variability was found in Anzoátegui and Monagas. The genotypic variability was assessed by in silico sequence comparison of the molecular markers and PCR-RFLP assays, demonstrating a marked polymorphism for the markers in insects of the domestic habitat in comparison with the other habitats. The highest polymorphism was found for the ?-tubulin marker with enzymes BamHI and KpnI. Additionally, the infection rate by T. cruzi was higher in Monagas and Sucre (26.8 and 37.0%, respectively), while in domestic habitats the infestation rate was highest in Anzoátegui (22.3%). Results suggest domestic habitat colonization by T. maculata that in epidemiological terms, coupled with the presence in this habitat of nymphs of the vector, represents a high risk of transmission of Chagas disease. PMID:25325053

García-Alzate, Roberto; Lozano-Arias, Daisy; Reyes-Lugo, Rafael Matías; Morocoima, Antonio; Herrera, Leidi; Mendoza-León, Alexis

2014-01-01

263

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

NASA Astrophysics Data System (ADS)

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

2014-06-01

264

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

265

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

PubMed

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

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

2009-03-01

266

High prevalence of asthma symptoms in Warao Amerindian children in Venezuela is significantly associated with open-fire cooking: a cross-sectional observational study  

PubMed Central

Background The International Study on Asthma and Allergies in Childhood (ISAAC) reported a prevalence of asthma symptoms in 17 centers in nine Latin American countries that was similar to prevalence rates reported in non-tropical countries. It has been proposed that the continuous exposure to infectious diseases in rural populations residing in tropical areas leads to a relatively low prevalence of asthma symptoms. As almost a quarter of Latin American people live in rural tropical areas, the encountered high prevalence of asthma symptoms is remarkable. Wood smoke exposure and environmental tobacco smoke have been identified as possible risk factors for having asthma symptoms. Methods We performed a cross-sectional observational study from June 1, 2012 to September 30, 2012 in which we interviewed parents and guardians of Warao Amerindian children from Venezuela. Asthma symptoms were defined according to the ISAAC definition as self-reported wheezing in the last 12 months. The associations between wood smoke exposure and environmental tobacco smoke and the prevalence of asthma symptoms were calculated by means of univariate and multivariable logistic regression analyses. Results We included 630 children between two and ten years of age. Asthma symptoms were recorded in 164 of these children (26%). The prevalence of asthma symptoms was associated with the cooking method. Children exposed to the smoke produced by cooking on open wood fires were at higher risk of having asthma symptoms compared to children exposed to cooking with gas (AOR 2.12, 95% CI 1.18 - 3.84). Four percent of the children lived in a household where more than ten cigarettes were smoked per day and they had a higher risk of having asthma symptoms compared to children who were not exposed to cigarette smoke (AOR 2.69, 95% CI 1.11 - 6.48). Conclusion Our findings suggest that children living in rural settings in a household where wood is used for cooking or where more than ten cigarettes are smoked daily have a higher risk of having asthma symptoms. PMID:23870058

2013-01-01

267

[The health system of Venezuela].  

PubMed

This paper describes the Venezuelan health system, including its structure and coverage, financial sources, human and material resources and its stewardship functions. This system comprises a public and a private sector. The public sector includes the Ministry of Popular Power for Health (MS) and several social security institutions, salient among them the Venezuelan Institute for Social Security (IVSS). The MH is financed with federal, state and county contributions. The IVSS is financed with employer, employee and government contributions. These two agencies provide services in their own facilities. The private sector includes providers offering services on an out-of-pocket basis and private insurance companies. The Venezuelan health system is undergoing a process of reform since the adoption of the 1999 Constitution which calls for the establishment of a national public health system. The reform process is now headed by the Barrio Adentro program. PMID:21877092

Bonvecchio, Anabelle; Becerril-Montekio, Victor; Carriedo-Lutzenkirchen, Angela; Landaeta-Jiménez, Maritza

2011-01-01

268

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

2001-01-01

269

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

SciTech Connect

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

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

1997-08-01

270

Servicio de Informacion para la Orientacion Educativa. Guia para su Interpretacion y Uso. (Information Service for Educational Counseling. Guide for Its Interpretation and Use.)  

ERIC Educational Resources Information Center

In 1974, the College Board in Puerto Rico initiated a program on educational counseling for high school-bound students. The program was designed to help students define their educational goals and career interests before entering the ninth grade where they would be required to make specific curriculum choices. The program calls for the…

College Entrance Examination Board, Hato Rey, PR. Puerto Rico Office.

271

Determinants of Corn Import Demand: Venezuela.  

National Technical Information Service (NTIS)

Venezuelan feed manufacturers and livestock producers rely on imported feed grains because domestic feed supplies, mainly sorghum, are available only for a few months of the year. The United States is the traditional supplier of yellow corn to the Venezue...

E. Dusch, P. Setia

1994-01-01

272

Universidad Central de Venezuela Facultad de Ciencias  

E-print Network

tóxicos sin posibilidad de reciclaje) Green Computing o Computación Verde(informática ecológicamente mayores desperdicios ambientales Desarrollo de productos informáticos ecológicos y promueve el reciclaje

Cardinale Villarreal, Yudith C.

273

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.

1995-12-01

274

Los Maestros en Venezuela: Carreras e Incentivos  

Microsoft Academic Search

El estudio comparativo del que este papel de trabajo forma parte (Los Maestros en América Latina: Carreras e Incentivos) fue emprendido para intentar avanzar en el conocimiento de los incentivos y factores institucionales que determinan la composición del cuerpo docente y que influencian el desempeño profesional del mismo, en un grupo de países de la región. Cada uno de los

Olga Ramos; Milko González; Josefina Bruni Celli

2001-01-01

275

Hearing-Impaired Children in Venezuela: 1985.  

ERIC Educational Resources Information Center

The 1984-85 Venezuelan Survey of Deaf Children collected information on 804 deaf students between ages 3 and 14. Among findings were that 29% of the cases were caused by maternal rubella, that 36% had additional handicaps, and that meningitis was the most frequently reported after-birth cause of hearing losses. (Author/DB)

Schildroth, Arthur; And Others

1987-01-01

276

Universidad Central de Venezuela Facultad de Ciencias  

E-print Network

básicos de estructuras de datos dinámicas y de teoría de grafos. Palabras Claves: Grafos. Algoritmia. Algoritmos de Grafos. Procesamiento de Grafos. Estructuras de Datos para Grafos. Febrero, 2003 #12;CONTENIDO un conjunto de líneas o flechas. Por lo general, los nodos son entes de procesamiento o estructuras

Coto, Ernesto

277

Universidad Central de Venezuela Facultad de Ciencias  

E-print Network

método de modelado de objetos difusos como fuego, nubes y agua. Los sistemas de partículas modelan un, agua y fuego es bastante difícil con las técnicas existentes de síntesis de imágenes. Estos objetos

Coto, Ernesto

278

Venezuela at a Crossroads: Will the re-election of Chvez be a victory for Venezuela?  

E-print Network

An exploration of current events and controversial topics in Latin America. Hot Topics A Latin American Research and Department of French, Italian & Spanish. Monique has recently worked in the non-profit sector of the most recognizable and controver- sial political leaders in the Americas, due in part to his belligerent

Habib, Ayman

279

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

E-print Network

to a standstill and so is now earmarked for `major restructuring' by the Ministry of Energy and Mining. Our asteroid impact Sir -- An important, technically valid analysis of meteoric fireball data (P. Brown et al burn up harmlessly high in the Earth's atmosphere. Thus they constitute no direct danger. Only objects

Chapman, Clark R.

280

Lagochilascaris minor infection in Venezuela. Report of a case.  

PubMed

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

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

1982-11-01

281

Onchocerciasis endemic in the State of Bolivar, Venezuela.  

PubMed

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

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

1989-08-01

282

A reservoir management strategy for multilayered reservoirs in eastern Venezuela  

E-print Network

. Iscander Diyashev and Dr. Dwane McVay from Holditch and Associates, for his help and advice. I would like to thank Fr. Michael Sis, Fr. Dean Wilhelm, Fr. David Konder}a, and all the Saint Mary's Catholic Church Community for their support, spiritual... . 4. 8 Permeability vs. Porosity Correlation for N-1 . 4. 9 Fracture Length in N-5 Formation. Well P-1 49 . 66 4. 10 Reservoir Grid Block . 69 4. 11 Cretaceous Cumulative Production - Well P-4. . 69 4. 12 Pressures Comparison - N-3. 70 5. 1 Core...

Espinel Diaz, Arnaldo Leopoldo

2012-06-07

283

State and Power after Neoliberalism in Bolivarian Venezuela  

E-print Network

War of Gods: Religion and Politics in Latin America. Verso.critique of religion and politics in Latin America has comereligion are conceptually distinct, the position of historical materialism to them in Latin America

Kingsbury, Donald V.

2012-01-01

284

The gravity field and plate boundaries in Venezuela  

E-print Network

Free-air and simple Bouguer anomaly maps of the Venezuelan continental margin (from 60°W to 72°W and from 7°N to 13°N) are presented. The major features of the free-air map are: the large lows associated with the deep ...

Folinsbee, Robert Allin

1972-01-01

285

Communication processes and consumerism: The case of Venezuela  

Microsoft Academic Search

This study investigates the influence of various television content types on different dimensions of consumerism. We hypothesize that exposure to different content on television (entertainment programming, telenovelas, and news) influences ideas on consumerism differentially. Interpersonal discussion of societal issues is assumed to have a positive impact on consumerism. Finally, we predict that several indicators of location within the social structure

Richard L. Allen

1992-01-01

286

Late Quaternary deglacial history of the Mérida Andes, Venezuela  

NASA Astrophysics Data System (ADS)

Radiocarbon-dated sediment cores from seven lakes and two bogs spanning the Cordillera de Mérida in the Venezuelan Andes were used to identify and date the regional history of late Pleistocene and Holocene glacial activity. Coring sites were selected at different elevations across a pronounced rain shadow from southeast (wet) to northwest (dry). Sediment lithostratigraphy and magnetic susceptibility, in conjunction with AMS radiocarbon dates on macrofossils and charcoal, were used to constrain deglaciation. The local expression of the Last Glacial Maximum occurred between 22 750 and 19 960 cal. yr BP. On the wetter southeastern side of the Cordillera de Mérida, glaciers had significantly retreated by 15 700 cal. yr BP, followed by several minor glacial advances and retreats between 14 850 and 13 830 cal. yr BP. At least one major glacial readvance occurred between 13 830 and 10 000 cal. yrBP in the wetter southeastern sector of the region. The drier northwest side of the Cordillera de Mérida records initial glacial retreat by 14240cal.yrBP. Multiple sites on both sides of the Mérida Andes record a further phase of extensive deglaciation approximately 10000cal.yrBP. However, the north-northwest facing Mucubají catchment remained partially glaciated until ca. 6000cal.yrBP. Deglacial ages from the Venezuelan Andes are consistently younger than those reported from the Southern Hemisphere Andes, suggesting an inter-hemispheric deglacial lag in the northern tropics of the order of two thousand years.

Stansell, Nathan D.; Abbott, Mark B.; Polissar, Pratigya J.; Wolfe, Alexander P.; Bezada, Maximiliano; Rull, Valentí

2005-10-01

287

Andean Indigenous Movements and Constitutional Transformation: Venezuela in Comparative Perspective  

Microsoft Academic Search

Political scientists and U.S. policy makers concerned about recent set- backs in the consolidation of democracy in the Andes and their potential to delay or reverse democratic progress throughout the region are paying a lot of attention to the Andean countries. Political party systems are in turmoil or have collapsed, authoritarian political leaders are enjoying significant popu- lar support, and

Donna Lee Van Cott

2003-01-01

288

Venezuela--The Teaching of Reading in Rural Schools.  

ERIC Educational Resources Information Center

Direct interviews with 17 teachers and observation in 31 rural and urban Venezuelan classrooms (pre-school through grade 6 in nine schools) across 3 states revealed serious reading difficulties among Venezuelan students. Small rooms and multi-grade class situations were common and school supplies and equipment were scarce. Even more scarce were…

Ramirez, Rhoda L.

289

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.

2010-01-01

290

RELACIÓN COMERCIAL SUPERMERCADO - PRODUCTOR DE FRUTAS FRESCAS Y HORTALIZAS EN EL ESTADO FALCÓN, VENEZUELA Commercial relation supermarket - producers of fresh fruit and vegetable of the Falcon State, Venezuela  

Microsoft Academic Search

Resumen Se caracterizaron las relaciones comerciales existentes entre los productores de frutas fres- cas y hortalizas y los supermercados en el estado Falcón, con el propósito de determinar el nivel y naturaleza de participación del productor agrícola falconiano dentro del nuevo es- quema de distribución agroalimentaria existente en el país y, conocer así los mecanismos de acción de estas relaciones

Henri Piña Zambrano

291

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

E-print Network

2069. 2 578 I 31. 3 61 3 tmver Naricoal 47. 8 344. 3 63. 4 2. 0 312. 5 306 0 61. 6 33. 3 208. 8 543. 8 38. 9 175. 7 427. 6 103. 3 16. 7 loskdg~md 1. 3204 I 8210 1. 8780 1. 3729 1. 8256 2. 1442 1. 661 1. 5963 1. 7697 2. 2753... 2069. 2 578 I 31. 3 61 3 tmver Naricoal 47. 8 344. 3 63. 4 2. 0 312. 5 306 0 61. 6 33. 3 208. 8 543. 8 38. 9 175. 7 427. 6 103. 3 16. 7 loskdg~md 1. 3204 I 8210 1. 8780 1. 3729 1. 8256 2. 1442 1. 661 1. 5963 1. 7697 2. 2753...

Medina Tarrazzi, Trina Mercedes

2012-06-07

292

Evidence for a Younger Dryas glacial advance in the Andes of northwestern Venezuela  

NASA Astrophysics Data System (ADS)

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 the surface of Late Glacial till, provides a within-glacier advance age of 12.4 ka cal BP. The peat lies on moraine deposited during a stillstand event when the Humboldt Glacier retreated to the area of Lago Verde at ˜ 4000 m a.s.l. Approximately 0.5 km upvalley, toward Lago Suero, YD till buries peat deposited in glaciolacustrine sediments of presumed Late Glacial age. Farther north, in the Mucuñuque-Mucubají Catchment of the eastern cordillera, a push moraine of possible YD age buries older till of Late Glacial age; ˜ 0.2 km upvalley, outwash of YD age buries glaciolacustrine peat and organic-rich alluvial sediment dated to 13.7 and 13.3 ka cal BP. The latest Mérida advance documented here is approximately synchronous with the YD cold event of Europe and the North Atlantic Region (ca. 11.6-12.7 ka cal BP). The YD event in both areas of the northwestern Venezuelan Andes nearly reestablished earlier Late Glacial ice positions, and termination appears to have been abrupt; the valleys in both areas were evacuated of YD ice without emplacement of recessional moraines as during the main deglaciation. At the Humboldt site, equilibrium line altitudes (ELA's) for the Late Glacial were about 50 m lower than during the inferred YD; in the Mucuñuque-Mucubají catchment, ELA's for the Late Glacial (~ 3900 m a.s.l.) are difficult to establish given the absence of lateral moraines.

Mahaney, William C.; Milner, M. W.; Kalm, Volli; Dirszowsky, Randy W.; Hancock, R. G. V.; Beukens, Roelf P.

2008-04-01

293

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

E-print Network

and the consequences of behavior by means of observa- tion and 1mitation accounts for fluctuations in the con- tent and incidence of violent political acts performed within the limits of a colonial cr national political sys- tem. It is held that acts of politioal... stimuli represent1ng rewards and. oppor- tunities to avoid punishment associated wiCh the perform- ance of violent political acts. Efforts designed to empirically test hypotheses in- spired. by social learning theory entailed the collection of date...

Roberts, Sherman Douglas

2012-06-07

294

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

E-print Network

). There exist significant threats to the survival of the species in Asia, Central America and the Caribbean region (Fleming 2001, Chac?n 2004, Campbell 2007, Buitrago et al. 2008). Serious threats to the hawksbill turtle include illegal take in large part... environments (Green et al. 2000, Schweizer et al. 2005, Mishra et al. 2006, Wright & Heyman 2008). The spatial resolution of these systems ranges from 30 m for the Landsat Thematic Mapper (TM), to 4 m for the IKONOS multispectral data, and down to 2.44 m...

Hunt, Luciana E.

2010-10-12

295

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

E-print Network

, Pume girls reach menarche at age 12.9, and give birth to their first child at age 15 the human mean age at first birth between 17.3 and 19.7 (Hawkes et al., 1998; Blurton Jones et al., 1999 is considered, mean ages at first birth vary from 16.2 to 25.7 (Walker et al., 2006). This article uses

Kramer, Karen L.

296

Mediating regional development : how metalworking firms forged lasting linkages with steel in Ciudad, Guayana, Venezuela  

E-print Network

Ever since the late 1950s, planners have lured large firms to lagging regions with the expectation that they will trigger local industrial activity. According to the literatures on unbalanced growth, growth poles, foreign ...

Döhnert, Sylvia, 1970-

2003-01-01

297

Self-aware sex education: a theoretical and practical approach in Venezuela.  

PubMed

Even a few decades ago, it was considered normal and even desirable in Latin America for young women to become pregnant before they were 20--provided they were married; while young men were expected to become sexually active as soon as they entered adolescence, without much concern about potential risks or with whom they did so--as long as it was a woman. This view is now changing. There seems to be a general consensus that 'education' is necessary to prevent adolescent pregnancy, abortion, STI/HIV and sexual abuse. Attempts to reach agreement as to what kind of education and where, and how and when to provide it often fail, however, because of the conflicting views of sexuality upon which they are based. This article discusses conflicting concepts of sexuality and describes the theory of critical pedagogy followed by AVESA, a Venezuelan NGO whose work focuses on sexuality, problems of sexuality and alternative sex education. It describes AVESA's practical experience in training youth promoters and running on ongoing youth education programme in sexual and reproductive health. AVESA advocates an educational alternative that builds self-awareness and a critical understanding of social reality. We encourage individuals to engage with their own history and circumstances in order to be able to experience their sexuality in a full, responsible, pleasurable and just manner. PMID:11468830

Muñoz, M

2001-05-01

298

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

Microsoft Academic Search

of the parasite's genome. The P. falciparum isolates are a mono- phyletic clade, significantly different from the other Plasmodium species. We identify three RAPD characters that could be useful as ''tags'' for rapid species identification. The Venezuelan genotypes fall into two discrete genetic subdivisions associated with either the dry or the rainy season; the isolates collected in the rainy seasonexhibitgreatergeneticdiversity.Thereissignificantlinkage

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

2001-01-01

299

The Impact of Load Behavior on Voltage Stability, an Application Case in ENELVEN \\/ VENEZUELA  

Microsoft Academic Search

Economical system expansion strategies and reliable system operation, requires comprehensive system simulation studies. If computer models fail to describe the real system behavior a risk to degrade operation performance is introduced. Consideration of typical models according to IEEE for prime mover and AVR's are often used. Improved load models accurately representing the steady state and dynamic behavior are seldom available

Emil Kermendey; Nervis Villalobos; Martin Schmieg

300

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

E-print Network

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

Williams, John David

2012-06-07

301

A reservoir characterization for a complex multilayered system in Eastern Venezuela  

E-print Network

simultaneously acquired pressure and flow rate transient data for several layers during the course of one well test. Ehlig- Economides found that the layer flow rate transient is sensitive in early times to skin effect and the layer permeability, while... in the late time, to the formation crossflow efFects Raghavan", wrote an important paper in 1989, on the analysis of layered reservoirs. Raghavan examined the performance and productivity of a well producing from a commingled reservoir and extended his...

Avila, Carmen Esther

2012-06-07

302

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

SciTech Connect

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

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

1993-02-01

303

Scratching Behind the Walls; Graffiti and Symbolic Political Imagination at Cuartel San Carlos (Caracas, Venezuela)  

Microsoft Academic Search

\\u000a Rock art is as old as human history. South American rock carvings and paintings provide invaluable evidence of our aboriginal\\u000a past. As a matter of fact, spontaneous artistic interventions on buildings and walls (equivalent to modern graffiti) appear\\u000a for the first time in Ancient Egypt and Greece. But urban graffiti is definitely a modern phenomenon. It is typical of late

Rodrigo Navarrete Sánchez; Ana María López

304

[The professional title of urbanist in Venezuela: the experience of the Universidad Simon Bolivar].  

PubMed

The principles and concepts of the profession of urbanism are presented, and the experience of the University Simon Bolivar in the field is summarized. The perspective of urbanism is that the chaos and poor quality of life in many Latin American metropolitan areas are problems that can be solved through creation of an urban authority that would reconcile urban growth with quality of space and rationality of process. The field of urbanism was dominated for its first century by architects, engineers, and hygienists. In the 1960s, undergraduate programs were designed in town planning, city planning, and urban planning in Great Britain and the US to offer interdisciplinary training, with greater emphasis on the social sciences, mathematical methods of modeling, and distinctness from architecture. The university Simon Bolivar created an urbanism program in 1975, which like other Latin American programs gave somewhat greater emphasis to training in spatial design than did the US and British programs. The program has continued to be based on a systemic focus and the union of design and management in urban planning practice. The object of study has been redefined to encompass not just the city but the general environment. The program in its first 20 years has had internal problems such as the tendency of some professors to over-emphasize their own disciplines and insufficient training in management techniques, and external problems such as the negative societal image of urbanism and urbanization. Reinforcement of the computer capabilities and faculty should enable the program to meet future challenges. PMID:12348997

Gonzalez Tellez, S

1996-01-01

305

Geoquímica orgánica de los carbones de fila maestra, estado anzoátegui, Venezuela  

NASA Astrophysics Data System (ADS)

The vertical and lateral variability of organic geochemical parameters was established for the Seam 4 of the Fila Maestra coal deposit (Quebradon Formation, Oligocene-Early Miocene age) through the study of coals and carbonaceous shales collected in different outcrops of the coal seam. Chemical and physical analysis included moisture and ash contents, maceral groups, vitrinite reflectance, total carbon, bitumen and its fractions, as well as characterization of saturated hydrocarbons by gas chromatography ( n-alkane distributions and {pristane}/{phytane} ratios). A production sample, representative of the Seam 4, was further analyzed for S, Cl, C, H, O and its calorific value determined. The data collected allowed us to classify these samples as high-volatile bituminous coals, types B and C, according to ASTM classification. The results of the analysis showed little vertical or lateral variation in the properties studied. A gradual increase in ash content in the westward direction, together with a thinning of the coal seam, suggest a greater proximity of the basin border in this direction. High values in {pristane}/{phytane} ratio (4-7), predominance of heavy alkanes and high contents in vitrinites clearly indicates that primigenic organic matter was essentially continental in character. However, the bimodal n-alkane distribution, together with a nigh sulfur (2.7%) and chlorine (0.12%) contents suggest a marine-influenced environment. In consequence, it is proposed that these coals were formed in a transitional environment, as salt-marshs in coastal lagoons or in low deltaic plains. These results are in agreement with the stratigraphic analysis of the sedimentary unit.

Moreno, O.; Martinezy, M.; Escobar, M.

1995-04-01

306

Prevalencia de deficiencia subclínica de vitamina A y desnutrición en niños marginales de Maracaibo - Venezuela  

Microsoft Academic Search

RESUMEN. El presente estudio fue realizado para estimar la prevalencia de deficiencia de vitamina A en niños, mediante examen clínico, oftalmológico y por citología de impresión conjuntival (CIC); y el estado nutricional, analizando los indicadores antropométricos T\\/\\/E, P\\/\\/E y P\\/\\/T. La población de estudio incluyó 157 niños, 2-6 años de edad, provenientes de barrios marginales urbanos y rurales de Maracaibo,

Haydée V. Castejón; Pablo Ortega; María E. Díaz; Daisy Amaya; Gisela Gómez; María Ramos; María V. Alvarado; Jesús R. Urrieta

307

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

E-print Network

by the gassy sediment in the mud layer, and the high attenuation of the compressional and shear waves. This mud layer sediment is heavy and is not suspended in the water. Furthermore, it is compacted enough to support shear stresses and, therefore, has a...

Perez Arredondo, Javier Antonio

2004-09-30

308

The inverted Lamar sub-basin, Lake Maracaibo, Venezuela: Tectonic evolution and hydrocarbon habitat  

SciTech Connect

In the central part of the Maracaibo basin, integration of recently acquired 3-D seismic and existing geological data has led to the definition of the Lamar sub-basin as an array of partially inverted half grabens which formed during Late Cretaceous and Early to Middle Eocene times as a result of transtensional episodes along older rift structures. This integration exercise has also led to the addition of new reserves in a mature oil province. Six major tectonic phases can be distinguished: (a.) Extension of the existing Paleozoic substrate during Jurassic rifting; (b.) Passive margin tectonic quiescence from Middle to Late Cretaceous; (c.) Paleocene uplift and erosion; (d.) Eocene transtension along reactivated Jurassic lineaments; (e.) Late Eocene to Mid Miocene inversion; (f.) Late Miocene to Recent post inversion and regional tilt. Distinctive tectonically induced unconformities within the Eocene sedimentary fill imply tectonic overprint rather than eustatic controls. The Eocene extensional structures were inverted in a selective manner depending upon their orientation relative to the dominant compressional vector. This in turn resulted in significant hydrocarbon re-migration and a rather complex fluid distribution throughout the area.

Arminio, J.F. [Maraven S.A., Caracas (Venezuela); Growcott, A.M. [Intera Information Technologies, Henley-Upon-Thames, Oxfordshire, (United Kingdom)

1996-08-01

309

ALGUNAS CONSIDERACIONES PARA LA IMPLEMENTACIÓN DE POLÍTICAS EDUCATIVAS PARA PERSONAS SORDAS EN VENEZUELA  

Microsoft Academic Search

This article, presented as an essay, develops an analysis of education as a government policy and how it can be transferred to a situation particular to deaf people as a linguistic minority, due to the fact that the use of a language different to the official tongue creates a variety of conflicts. The study is based on documentary research which

Ana Maria Morales García

310

Fertility and rate of growth in a beef cattle herd in the 0rient of Venezuela  

E-print Network

of cow (3, 4 and 5 or more years), lactation status (dry and wet), year of calving and breed of sire within year. Interactions considered were not significant. Cows showed higher calving percentage than heifers, although means showed a depression... in the fertility of 4-year-old cows as a result of difficulty in breeding the first calf heifers. Lactation was the most important factor affecting calving percentage. Calving percentages for lactating and nonlactating cows were 37. 07 and 60. 22, respectively...

Gonzalez Crespo, Justo Nicolas

2012-06-07

311

Estado nutricional de hierro y parasitosis intestinal en niños de Valencia, Estado Carabobo, Venezuela  

Microsoft Academic Search

Abstract: Abstract: Abstract: Abstract: Iron deficiency is worldwide spread and ferropenic anemia is its most severe manifestation. Age, poverty and parasitic infestations are some associated factors. This study was aimed to evaluate iron nutritional status and to establish relationship with age, gender and intestinal parasitic infestations in 264 children (aged 3 to14 years) attending to a school at Valencia, Carabobo.

María Adela Barón; María Concepción Páez

312

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

Federal Register 2010, 2011, 2012, 2013

[Federal Register Volume 78, Number 143 (Thursday, July 25...Investigations and Scheduling of Preliminary Phase Investigations. AGENCY: United States...investigations and commencement of preliminary phase antidumping investigation Nos....

2013-07-25

313

IMF conditionality and rule of law: exceptional powers and banking in Malaysia and Venezuela  

Microsoft Academic Search

The 1990s was a decade marked by the implementation of market reforms worldwide. Countries in Latin America and Asia experimented with neoliberal programs sponsored by international financial institutions (IFIs) in order to adopt the arrangements required for the functioning of a market economy. The International Monetary Fund (IMF) joined in these efforts and incorporated structural requirements in its programs as

Gabriel Garcia

2009-01-01

314

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

E-print Network

June 1994. . Stomach contents of one Inia geoffrensis. 10 10 32 47 50 52 52 52 53 60 62 INTRODUCTION River dolphins of the species Inia geoffiensis inhabit the massive Amazon and Orinoco River basins of South America (Best and da Silva... 1993). Throughout its range, fnia is known by many common names, including tonina and bufeo in Spanish, and bofo in Portuguese. In the English speaking world, inia is often referred to as the Amazon dolphin or the pink dolphin. The species...

McGuire, Tamara Lee

2012-06-07

315

Chemical composition and biological activity of Conyza bonariensis essential oil collected in Mérida, Venezuela.  

PubMed

The essential oil from aerial parts of Conyza bonariensis (L) Cronquist collected in Mérida was obtained by hydrodistillation and analysed by GC/MS. The major components were trans-beta-farnesene (37.8%), trans-ocimene (20.7%) and beta-sesquiphellandrene (9.8%). Cytotoxicity assay was also performed with the essential oil against HeLa (cervix carcinoma), A-459 (lung carcinoma) and MCF-7 (breast adenocarcinoma) human cell lines and against normal Vero cells (African green monkey kidney) with IC50 values ranging from 1.4 to 45.8 microg/mL. Additionally, the essential oil presented a significant bactericidal effect against Bacillus cereus, while a moderate activity was observed against Staphylococcus epidermidis and Candida albicans. PMID:24079198

Araujo, Liliana; Moujir, Laila M; Rojas, Janne; Rojas, Luis; Carmona, Juan; Rondón, María

2013-08-01

316

The differential impact of real interest rates and credit availability on private investment: evidence from Venezuela  

Microsoft Academic Search

In the 1970's, some economists, led by McKinnon (1973) and Shaw (1973), began to argue in favor of financial liberalization as a medium of promoting saving, investment, and growth. This was based on the argument that real interest rates are frequently negative in developing countries due to administrative controls on the nominal interest rates and heavy regulation in the financial

Omar A Mendoza Lugo

317

Biological monitoring of mercury exposure in individuals referred to a toxicological center in Venezuela  

Microsoft Academic Search

People in developing countries are often considered at greater risk of mercury (Hg) poisoning due to a variety of factors including a lack of awareness regarding their occupational risks. Individuals requiring urine mercury (U-Hg) analysis at the Center for Toxicological Investigations of the University of Carabobo (CITUC), between 1998 and 2002 were studied to identify demographic characteristics associated to U-Hg

Maritza Rojas; David Seijas; Olga Agreda; Maritza Rodríguez

2006-01-01

318

[Heavy metal distribution in superficial sedimenta ta Saco, Gulf of Cariaco, Sucre, Venezuela].  

PubMed

The Gulf of Cariaco is a marine ecosystem with high primary productivity, which gives it an ecological and socioeconomic importance. Nevertheless, anthropogenic activities around the Gulf produce wastes that are deposited directly or by runoff into the sediments, and consequently, increases concentrations of metals in this ecosystem. The objective of this study was to determine the distribution of cadmium, copper, lead, manganese, nickel and zinc in geochemical fractions of surface sediments, using modified BCR sequential extraction procedure. The concentrations were measured using flame atomic absorption spectroscopy. In addition, the contents of soluble and exchangeable metals associated to carbonate fractions, determined by BCR, were compared with those determined by the method of Campanella. Samples were collected in 12 stations during June 2007. The applied methodologies were evaluated with a certified reference material of marine sediments (HISS-1) and the results indicated that these methods provide adequate accuracy and precision for the extraction of metals. The total metal concentrations (microg g(-1)) were, Cd: < limit of detection (LD)-5.0; Pb: 1.79-60.41; Cu: no detected (ND)-42.18; Zn: 25.13-104.57; Mn: 66.31-80.29 and Ni: 3.29-24.58. Cd, Cu, Ni and Pb at several stations, exceeded the Canadian Sediment Quality Guidelines of the Lowest Effect Levels (LEL). Cadmium was identified as being the most mobile of the elements, having the highest concentrations in soluble and exchangeable cations and carbonates. However, Pb, Cu, Mn and Zn levels were found highly associated to organic matter and sulfide fractions. The methods did not show significant statistical differences for the extraction of soluble and exchangeable cations and the metals associated to carbonate fraction. There are several significant correlations between heavy metals, which suggest their common origin. PMID:21302528

Valentina Fuentes, María; Rojas de Astudillo, Luisa; Diaz, Alfredo; Martínez, Gregorio

2010-10-01

319

[Dana swimming crab growth Callinectes danae (Decapoda: Portunidae) from Margarita Island, Venezuela].  

PubMed

Callinectes danae is a common species captured with crab traps in nearby areas of coastal lagoons in Margarita Island. Although its considerable economic importance as a fishery resource, few studies have been done on population dynamics and its fishery potential in local coastal environments to support decision making in fishery administration. We present growth pattern details of Callinectes danae to better estimate its population size and exploitation feasibility. For this, we analyzed a total of 3 623 specimens that were monthly captured in crab pots by artisanal fishermen in Las Marites lagoon, from October 2007 to September 2008. The length-weight ratio was determined, and growth parameters estimated from both length and weight curves of the von Bertalanffy model. The general sex ratio showed no significant difference between males and females (chi2 = 0.04, p > 0.05). However, values of slopes b between males and females were significantly different (t(s) = 2.75, p < 0.05), as well as intercepts a (t(s) = 2.44, p < 0.05). Thus, the length-weight ratio was determined separately: W = 7.48e(-5)*L(2.98) for males and W = 1.21e(-4)*L(2.87) for females, indicating a negative allometric growth in both sexes. Growth parameters were established as: L(infinity) =134.80mm, W(infinity) = 166.04g and k = 0.86/yr for males; L(infinity) = 122.35mm, W(infinity) = 118.45g and k = 0.63/yr for females. Lifespan was estimated at 3.05 years for males and 4.24 years for females. We concluded that Callinectes danae is a species with short lifespan and moderately rapid growth. The coefficient of variation values (CV), of the phi-prime growth performance index (Ø'), showed a different growth pattern compared to those obtained in other regions. We propose that a management strategy will be the periodical review of the minimum capture size for fishing area, after the great variability found in growth parameters. PMID:22208071

Castillo, Jesylén; Eslava, Nora; González, Leo Walter

2011-12-01

320

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

Microsoft Academic Search

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

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

2009-01-01

321

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

E-print Network

an accessory stria (Fig. 18). Distribution. Members of this genus occur in Central and South America, as far north as Costa Rica and as far south as Cuzco, Peru (Spangler and Santiago-Fragoso 1987). Habitat. Disersus species can be found in fast...

Maier, Crystal A.

2013-09-05

322

New ideas about displacement and history of El Pilar fault, Eastern Venezuela  

SciTech Connect

El Pilar fault system has been subject to much controversy concerning its geodynamic significance and cinematic characteristics assigned it by various authors. One of the most widespread ideas is that this fault system is a segment of the boundary between Caribbean and South American plates, and exhibits a predominantly dextral displacement that could have attained 1000 km since beginning of the Tertiary. A dextral displacement is suggested of some 150 km during the last 15 ma at a rate of 1 cm/a, based on tectono-stratigraphic relationships across the fault system. If we admitted that El Pilar system constitutes the principal boundary between Caribbean and South American Plates, movement would have begun at beginning of Middle Miocene when the compressive phase began that was responsible for uplift and southeastward overthrusting of the Interior and Coastal Ranges.

Giraldo, C. (Corpoven S.A., Caracas (Venezuela))

1993-02-01

323

Leadership for Social Justice: Authentic Participation in the Case of a Community Center in Caracas, Venezuela.  

ERIC Educational Resources Information Center

Describes the leadership conditions that encouraged authentic participation of community members in a Venezuelan community center to advance social justice. Argues that urban educational transformation might succeed in terms of practicing social justice, if leadership facilitates and creates urban sanctuaries and creates a trusting environment…

Goldfarb, Katia Paz; Grinberg, Jaime

2002-01-01

324

Quantifying the seasonal variations in fluvial and eolian sources of terrigenous material to Cariaco Basin, Venezuela  

Microsoft Academic Search

The varved sediments that accumulate in the Cariaco Basin provide a detailed archive of the region’s climatic history, including a record of the quantity of fluvial and wind-transported material. In this study, we examine the sedimentological characteristics (clay mineralogy and grain size) of both surface sediments and sinking lithogenic material collected from sediment trap samples over a three-year period from

Aurora C. Elmore; Robert C. Thunell; Richard Styles; David Black; Richard W. Murray; Nahysa Martinez; Yrene Astor

2009-01-01

325

Who Votes for chavismo?: Class Voting in Hugo Chávez's Venezuela  

Microsoft Academic Search

The conventional wisdom about contemporary Venezuelan politics is that class voting has become commonplace, with the poor doggedly supporting Hugo Chávez while the rich oppose him. This class voting is considered both a new feature of Venezuelan politics and a puzzle given the multiclass bases of prior populist leaders in Latin America. I clarify the concept of class voting by

Noam Lupu

2010-01-01

326

Who Votes for chavismo? Class Voting in Hugo Chávez's Venezuela1  

Microsoft Academic Search

The conventional wisdom about contemporary Venezuelan politics is that class voting has become commonplace, with the poor doggedly supporting Hugo Chávez while the rich oppose him. This class voting is considered both a new feature of Venezuelan politics and a puzzle given the multiclass bases of prior populist leaders in Latin America. I clarify the concept of class voting by

Noam Lupu

327

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

E-print Network

- grabens trending northnortheast during the Jurassic period. The basin began to subside below sea level in the early stages of the Cretaceous (Lugo and Mann, 1995). Extensional tectonics continued through the early Late Cretaceous. A marine...- grabens trending northnortheast during the Jurassic period. The basin began to subside below sea level in the early stages of the Cretaceous (Lugo and Mann, 1995). Extensional tectonics continued through the early Late Cretaceous. A marine...

Choi, Byeonggoo

2006-10-30

328

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

USGS Publications Warehouse

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

Nordin, Carl F.; Perez-Hernandez, David

1989-01-01

329

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)

1996-08-01

330

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

USGS Publications Warehouse

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

McKee, Edwin Dinwiddie

1989-01-01

331

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

Microsoft Academic Search

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

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

1995-01-01

332

Subsidence Due to Oil Production in Western Venezuela: Engineering Problems and Solutions  

Microsoft Academic Search

Ground subsidence associated with oil pro­ duction in the east coast of Lake Maracaibo (Western Vene­ zuela) was detected as early as 1929. Maximum cummulative subsidence as of April 1990 is 5.03 m. Typical subsidence rates range from 5 cm\\/year along the coast to 20 cm\\/yr in inland areas subjected to intensive oil production. The geomorphology of the area (low,

JUAN MURRIA

333

Essential oil composition and antibacteral activity of Vismia baccifera fruits collected from Mérida, Venezuela.  

PubMed

The essential oil from the fruits of Vismia baccifera Triana & Planch. (Gutttiferae), collected in June 2009, was analyzed by GC/MS. A yield of 0.6% oil was obtained by hydrodistillation. Twenty-seven components were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base. The major components were trans-cadin-l1,4-diene (36.6%), cis-cadin-1,4-diene (18.8%) and beta-caryophyllene (11.9%). The essential oil showed a broad spectrum of antibacterial activity against the important human pathogenic Gram-positive and Gram-negative bacteria Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25992), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 23357) with MIC values ranging from 9 to 37 microg/mL. PMID:21615035

Rojas, Janne; Buitrago, Alexis; Rojas, Luis; Morales, Antonio; Lucena, María; Baldovino, Shirley

2011-05-01

334

Seismic hazard assessment in the Catania and Siracusa urban areas (Italy) through different approaches  

NASA Astrophysics Data System (ADS)

The seismic hazard assessment (SHA) can be performed using either Deterministic or Probabilistic approaches. In present study a probabilistic analysis was carried out for the Catania and Siracusa towns using two different procedures: the 'site' (Albarello and Mucciarelli, 2002) and the 'seismotectonic' (Cornell 1968; Esteva, 1967) methodologies. The SASHA code (D'Amico and Albarello, 2007) was used to calculate seismic hazard through the 'site' approach, whereas the CRISIS2007 code (Ordaz et al., 2007) was adopted in the Esteva-Cornell procedure. According to current international conventions for PSHA (SSHAC, 1997), a logic tree approach was followed to consider and reduce the epistemic uncertainties, for both seismotectonic and site methods. The code SASHA handles the intensity data taking into account the macroseismic information of past earthquakes. CRISIS2007 code needs, as input elements, a seismic catalogue tested for completeness, a seismogenetic zonation and ground motion predicting equations. Data concerning the characterization of regional seismic sources and ground motion attenuation properties were taken from the literature. Special care was devoted to define source zone models, taking into account the most recent studies on regional seismotectonic features and, in particular, the possibility of considering the Malta escarpment as a potential source. The combined use of the above mentioned approaches allowed us to obtain useful elements to define the site seismic hazard in Catania and Siracusa. The results point out that the choice of the probabilistic model plays a fundamental role. It is indeed observed that when the site intensity data are used, the town of Catania shows hazard values higher than the ones found for Siracusa, for each considered return period. On the contrary, when the Esteva-Cornell method is used, Siracusa urban area shows higher hazard than Catania, for return periods greater than one hundred years. The higher hazard observed, through the site approach, for Catania area can be interpreted in terms of greater damage historically observed at this town and its smaller distance from the seismogenic structures. On the other hand, the higher level of hazard found for Siracusa, throughout the Esteva-Cornell approach, could be a consequence of the features of such method which spreads out the intensities over a wide area. However, in SHA the use of a combined approach is recommended for a mutual validation of obtained results and any choice between the two approaches is strictly linked to the knowledge of the local seismotectonic features. References Albarello D. and Mucciarelli M.; 2002: Seismic hazard estimates using ill?defined macroseismic data at site. Pure Appl. Geophys., 159, 1289?1304. Cornell C.A.; 1968: Engineering seismic risk analysis. Bull. Seism. Soc. Am., 58(5), 1583-1606. D'Amico V. and Albarello D.; 2007: Codice per il calcolo della pericolosità sismica da dati di sito (freeware). Progetto DPC-INGV S1, http://esse1.mi.ingv.it/d12.html Esteva L.; 1967: Criterios para la construcción de espectros para diseño sísmico. Proceedings of XII Jornadas Sudamericanas de Ingeniería Estructural y III Simposio Panamericano de Estructuras, Caracas, 1967. Published later in Boletín del Instituto de Materiales y Modelos Estructurales, Universidad Central de Venezuela, No. 19. Ordaz M., Aguilar A. and Arboleda J.; 2007: CRISIS2007, Program for computing seismic hazard. Version 5.4, Mexico City: UNAM. SSHAC (Senior Seismic Hazard Analysis Committee); 1997: Recommendations for probabilistic seismic hazard analysis: guidance on uncertainty and use of experts. NUREG/CR-6372.

Panzera, Francesco; Lombardo, Giuseppe; Rigano, Rosaria

2010-05-01

335

Análisis clínico y epidemiológico de los accidentes por mordeduras de serpientes del género Bothrops en Venezuela [A clinical and epidemiological analysis of accidental bites by snakes of the genus Bothrops in Venezuela].  

PubMed

Clinical register of 60 patients bitten by Bothrops snake who assisted at Leopoldo Manrique Hospital and the Institute of Tropical Medicine (HLM-IMT) in Caracas during 1996-1997 were analysed. The accident was more frequent in males (45/75%). In 32 cases (53.3%) the snake was classified and 26 were Bothrops lanceolatus, 4 Bothrops venezuelensis and 2 Bothrops atrox. Anatomic regions more frequent bitten were superior members (40/66.6%): hands (36/60%), forearm (2/3.3%), elbow (1/1.6%) and arm (1/1.6%). On inferior members (20/33.3%): legs (6/10%), feet (10/16.7%), ankle (2/3.3%), and the hip (2:3.3%). The most frequent clinical manifestations in moderate and severe cases (33 patient) were pain (100%), oedema (98%), ecchymosis (76%), blisters (20%), necrosis (12%), abscess (6%) bleeding (19%), heart failure (1/1.6%), renal failure (1/1.6%). The blood clotting was evaluated in 60 (100%) cases and it was altered in 33 (55%) patients. No deaths were recorded. PMID:11107900

Rodríguez Acosta, A; Uzcategui, W; Azuaje, R; Aguilar, I; Girón, M E

2000-01-01

336

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

ERIC Educational Resources Information Center

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

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

337

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

ERIC Educational Resources Information Center

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

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

1999-01-01

338

Plasma physics. Proceedings. 7th Latin American Workshop on Plasma Physics (VII LAWPP 97), Caracas (Venezuela), 20 - 31 Jan 1997  

Microsoft Academic Search

The following topics were dealt with: general plasma theory, plasma confinement, shock waves and instabilities in plasma, plasma spectroscopy, astrophysical and space plasmas, pulse power experiments, plasma processing.

P. Martín; J. Puerta

1997-01-01

339

[Eating behavior disorders. Prevalence and clinical features in adolescents in the city of Maracaibo, Zulia State, Venezuela].  

PubMed

The purpose of this study was to identify the prevalence and clinical characterization related to eating disorders in adolescents from both sexes. In order to do so, the diagnostic criteria and psychological symptoms described by the DSM-IV were used. The sample for this study was constituted by 1,363 adolescents, taken from a population of 23,831 students, who were randomly selected. The sample was stratified taking into account whether they came from a public or a private school and the school levels (middle and high school). The A.B.A checklist was administered to the subjects. This checklist was designed to identify the symptoms that characterize each of the disorders that are the main focus of this study, using DSM-IV criteria. Results from this study show a prevalence of 0% for anorexia nervosa, 1.58% for bulimia nervosa, and .66% for binge eating disorder. Clinical characterization and psychological symptoms related to these disorders show distinguishing features that give distinctive traits to the subjects of this study. PMID:14552057

Quintero-Párraga, Evelyn; Pérez-Montiel, Ana Cristina; Montiel-Nava, Cecilia; Pirela, Dexy; Acosta, María Fernanda; Pineda, Ninoska

2003-09-01

340

From the model of El Sistema in Venezuela to current applications: learning and integration through collective music education.  

PubMed

Over the last years, El Sistema--the Venezuelan project started in 1975 and now acknowledged worldwide as the most significant example of collective music education--has inspired a profusion of remarkable initiatives on all continents. From the original impulse by founder José Antonio Abreu, strong social principles of integration are combined with specific musical approaches to achieve individual empowerment as a large-scale alternative to endemic juvenile crime, counteracting the risk factors of social unease, serving as a stimulating example toward emancipation, and providing professional opportunities to the talented. Such a network, in turn, proves to be a powerful instrument of cultural progress: the tenets of "Sistema" become shared values able to foster development, reaching into issues of disability and rehabilitation. This paper presents continuities and contrasts in various ramifications of such a successful trend and outlines perspectives for further impact of this powerful transformational agent. PMID:22524340

Majno, Maria

2012-04-01

341

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

E-print Network

identification of three different tendencies that correspond to the three regions identified in the reservoir; western, eastern and southwestern (Fig. 11). This probably reflects the extent of the field (8, 700 acres) and the faults inside the reservoir... amalgamation, and the connection transmissibility factor will bc calculated accordingly. This option was used to run three different cases: Case 1: The original grid model with 94, 500 cells. Case 2: Amalgamation of the western and southwestern regions...

Urdaneta Anez, Jackeline C

2012-06-07

342

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

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 3. 15 Time-isopach map of the interval comprised between the horizons Marker 0 and BFU in the Leona Area. . 120 3. 16 Seismic amplitude extraction map of the horizon Marker 0, which corresponds to T=O msec for the horizon slices constructed.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 3. 15 Time-isopach map of the interval comprised between the horizons Marker 0 and BFU in the Leona Area. . 120 3. 16 Seismic amplitude extraction map of the horizon Marker 0, which corresponds to T=O msec for the horizon slices constructed...

Flores Millan, Maria Carolina

2012-06-07

343

[Protozoans in superficial waters and faecal samples of individuals of rural populations of the Montes municipality, Sucre state, Venezuela].  

PubMed

In Sucre state, the Manzanares river is threatened by domestic, agricultural and industrial activities, becoming an environmental risk factor for its inhabitants. In this sense, the presence of protozoans in superficial waters of tributaries of the Manzanares river (Orinoco river, Quebrada Seca, San Juan river), Montes municipality, Sucre state, as well as the analysis of faecal samples from inhabitants of towns bordering these tributaries were evaluated. We collected faecal and water samples from may 2006 through april 2007. The superficial water samples were processed after centrifugation by the direct examination and floculation, using lugol, modified Kinyoun and trichromic colorations. Fecal samples where analyzed by direct examination with physiological saline solution and the modified Ritchie concentration method and using the other colorations techniques above mentioned. The most frequently observed protozoans in superficial waters in the three tributaries were: Amoebas, Blastocystis sp, Endolimax sp., Chilomastix sp. and Giardia sp. Whereas in faecal samples, Blastocystis hominis, Endolimax nana and Entaomeba coli had the greatest frequencies in the three communities. The inhabitants of Orinoco La Peña turned out to be most susceptible to these parasitic infections (77.60%), followed by San Juan River (46.63%) and Quebrada Seca (39.49%). The presence of pathogenic and nonpathogenic protozoans in superficial waters demonstrates the faecal contamination of the tributaries, representing a constant focus of infection for their inhabitants, inferred by the observation of the same species in both types of samples. PMID:21365874

Mora, Leonor; Martínez, Indira; Figuera, Lourdes; Segura, Merlyn; Del Valle, Guilarte

2010-12-01

344

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

SciTech Connect

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

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

1993-02-01

345

Vertical fluxes of particulate biogenic material through the euphotic and twilight zones in the Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Surface-tethered particle interceptor traps (PITs) were deployed at 50 and 100 m (1-3 days) on ten occasions in the Cariaco Basin between March 2007 and November 2009 to measure the settling fluxes of biogenic particles at 50 m (the base of the euphotic zone—Ez) and 100 m. Fluxes at these two depths were compared to concurrent fluxes estimated with moored sediment traps at 150, 225 and 410 m from the CARIACO Ocean Time-Series program. We measured particulate organic carbon (POC), particulate organic nitrogen (PON), calcium carbonate, biogenic silica and terrigenous material concentrations in samples collected with both the drifting and moored traps. We also estimated the fluxes of foraminifera shells and coccolithophore cells at 50 and 100 m using drifting traps samples. Surface chlorophyll a and primary production observations during each sampling period were examined to quantify the relationship between the magnitude and geochemical composition of the vertical flux and overlying production. Surface chlorophyll a concentrations and primary production rates were highest during months of upwelling (2.58-1.35 mg m-3 and 3.6-1.4 g C m-2 d-1, respectively). The fluxes of POC, PON, calcite and silica measured during the upwelling season (December-May) were typically higher than during the period of non-upwelling (August-November), when surface waters are more strongly stratified. POC fluxes measured with the drifting traps (50 and 100 m) varied between 0.95 (upwelling) and 0.14 g m-2 d-1 (non-upwelling), compared with those from the moored traps (150, 225 and 410 m) which ranged from 0.21 to 0.01 g m-2 d-1. Similarly, the fluxes of biogenic opal in the upper 100 m ranged from 1.12 and 0.18 g m-2 d-1, and those at greater depths varied from 0.27 g m-2 d-1 during upwelling to values near zero during stratification periods. The fluxes of POC, PON, calcite and silica in the upper 100 m decreased by an order of magnitude at the depth of the oxic-anoxic interface (>200 m). The sinking organic matter collected with the floating traps within the upper 100 m was significantly correlated with surface chlorophyll a concentrations (r=0.68, p<0.05) as a result of close coupling between the flux of biogenic particles and primary production. In contrast, there was no clear relationship between surface chlorophyll/primary production and fluxes measured below 150 m depth.

Montes, Enrique; Muller-Karger, Frank; Thunell, Robert; Hollander, David; Astor, Yrene; Varela, Ramón; Soto, Inia; Lorenzoni, Laura

2012-09-01

346

XXII CONGRESO LATINOAMERICANO DE HIDRÁULICA CIUDAD GUAYANA, VENEZUELA, OCTUBRE 2006 PREVISÃO AUTOMATIZADA DE ONDAS EM LAGOS DE BARRAGENS  

Microsoft Academic Search

From a software developed by the team of the College of Engineering of Ilha Solteira FEIS\\/UNESP, the purpose of this work is to processing of wind velocity and fetch, in order to estimate wave height in lakes of dams produced by winds. The software, named OndisaCAD, works inside of CADs environments, AutoCAD of the Autodesk for example, thus making possible

Geraldo de Freitas Maciel; Milton Dall; Aglio Sobrinho; Caio Nilo Marcon; Marcelo Marques

347

Pollen distribution in sub-Recent sedimentary environments of the Orinoco Delta (Venezuela) – an actuo-palaeobotanical study  

Microsoft Academic Search

A reinvestigation of the palynology of Recent and sub-Recent Orinoco Delta sediments complements the work by Jan Muller concerning the taxonomy and diversity of pollen grains. Surficial sediment samples and samples from shallow drill cores taken from three different deltaic environments (Cano Guaneira, mangrove forest, and palm-swamp) were studied with light microscopy and SEM. The standing vegetational types of the

Christa-Charlotte Hofmann

2002-01-01

348

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

E-print Network

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

Leveque, Soazig

2012-06-07

349

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

350

[Secondary metabolites, lethality and antimicrobial activity of extracts from three corals and three marine mollusks from Sucre, Venezuela].  

PubMed

The study of biochemical activity of extracts obtained from marine organisms is gaining interest as some have proved to have efficient health or industrial applications. To evaluate lethality and antimicrobial activities, some chemical tests were performed on crude extracts of the octocorals Eunicea sp., Muricea sp. and Pseudopterogorgia acerosa and the mollusks Pteria colymbus, Phyllonotus pomum and Chicoreus brevifrons, collected in Venezuelan waters. The presence of secondary metabolites like alkaloids, unsaturated sterols and pentacyclic triterpenes in all invertebrates, was evidenced. Additionally, sesquiterpenlactones, saponins, tannins, cyanogenic and cardiotonic glycosides were also detected in some octocoral extracts, suggesting that biosynthesis of these metabolites is typical in this group. From the lethality bioassays, all extracts resulted lethal to Artemia salina (LC50<1000 microg/ml) with an increased of lethal activity with exposition time. P. pomum extract showed the highest lethality rate (LC50=46.8 microg/ml). Compared to the octocorals, mollusks extracts displayed more activity and a greater action spectrum against different bacterial strains, whereas octocorals also inhibited some fungi strains growth. Staphylococcus aureus was the most susceptible to the antimicrobial power of the extracts (66.7%), whereas Pseudomonas aeruginosa, Candida albicans and Aspergillus niger were not affected. The antibiosis shown by marine organisms extracts indicates that some of their biosynthesized metabolites are physiologically active, and may have possible cytotoxic potential or as a source of antibiotic components. PMID:20527468

Ordaz, Gabriel; D'Armas, Haydelba; Yáñez, Dayanis; Hernández, Juan; Camacho, Angel

2010-06-01

351

Deglacial and Holocene Records of Climate Change in the Tropics from Lake Sediments, Cordillera de Merida, Venezuela  

NASA Astrophysics Data System (ADS)

Tropical regions, covering 50% of the globe (30N-30S), are a substantial component of the climate system. They are an influential factor in both the global energy balance and hydrologic cycle, therefore climatic changes in the tropics can have global climate effects. Here we present results from a project which aims to reconstruct the Holocene climate history of the Venezuelan Andes on century to millennial timescales using multi-proxy analyses of lake sediment cores. Sediment records from four lakes in the Cordillera de Merida, Venezuelan Andes, record changing moisture balance and glacial activity from ~15,000 years BP to the present. Sediments from Laguna Mucubaji a lake with no glaciers presently in the watershed and maximum watershed elevations approximately 500m below the modern glaciation limit (5200m), show variations in clastic input which appear to be caused by the establishment and fluctuations of glaciers in the watershed. Biogenic opal oxygen isotope records from Laguna Verdes Alta and Baja, small lakes 4200m a.s.l., reflect changing regional moisture balance and possibly shifts in the isotopic composition of precipitation during the Holocene. The lakes are situated 0.5km from each other but have different hydrologic balances, thus viewing the records in tandem may give a better understanding of hydrologic change in the region. Diatom species abundance records from these lakes constrains the magnitude and timing of lake-level change associated with hydrologic change. The fourth lake, Laguna Blanca, is a small bog located 1800m a.s.l. The sediments from this lake alternate between organic rich and organic poor facies, apparently as a result of changing hydrologic balance. Lower lake levels result in greater organic sedimentation dominated by plant macrofossils while higher lake levels produce clayey organic poor sediments. Following deglaciation (~15,000 calibrated years BP) generally drier and/or cooler conditions prevailed in this region. Sediments from Laguna Mucubaji record significant glacial activity in the early Holocene. Relatively quiescent conditions prevailed during the middle- and late- Holocene punctuated by a distinct climate shift coeval with the Little Ice Age. Sediments from Mucubaji indicate glacial activity in the watershed while Lagunas Blanca and Verdes Baja record wetter conditions during this interval.

Polissar, P. J.; Abbott, M. B.; Shemesh, A.; Finney, B. P.; Wolfe, A. P.; Rull, V.; Bezada, M.; Bradley, R. S.

2002-12-01

352

The Knowledge that Counts: Institutional Identities, Policy Science, and the Conflict Over Fire Management in the Gran Sabana, Venezuela  

Microsoft Academic Search

Summary. — The cultures of environmental planning agencies shape institutional identities and management interventions. Central to such institutional cultures is knowledge production, which is shaped by political-economic processes, dominant narratives and institutional desires to produce ''conservation'' landscapes. Through knowledge production, certain scientific knowledge and data are appropriated, while others are excluded. In the case of fire management in the Gran

Bjørn Sletto

2008-01-01

353

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

NASA Astrophysics Data System (ADS)

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

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

2005-11-01

354

The importance of subsurface nepheloid layers in transport and delivery of sediments to the eastern Cariaco Basin, Venezuela  

E-print Network

The importance of subsurface nepheloid layers in transport and delivery of sediments to the eastern: Nepheloid layers Cariaco Basin Particulate organic matter Sediment transport a b s t r a c t Optical of September 2003 and 2006. Our results suggest that nepheloid layers originating at the mouth of small

Benitez-Nelson, Claudia

355

The importance of subsurface nepheloid layers in transport and delivery of sediments to the eastern Cariaco Basin, Venezuela  

NASA Astrophysics Data System (ADS)

Optical transmissometer measurements were coupled with particulate organic matter (POM) observations to understand suspended sediment composition and distribution in the eastern Cariaco Basin during the rainy seasons of September 2003 and 2006. Our results suggest that nepheloid layers originating at the mouth of small mountainous rivers discharging into the eastern Basin are a major delivery mechanism of terrigenous sediments to the Basin interior. Intermediate nepheloid layers (INL) were observed near the shelf break (˜100 m) and appear to effectively transport terrigenous material laterally from the shelf to deep waters, thereby providing a plausible supply mechanism of the terrestrial material observed in sediment traps. These findings highlight the importance of small, local rivers in the Cariaco Basin as sources of terrestrial material. In contrast, these nepheloid layers contained only limited POM. When this information is combined with published sediment trap POM data, it suggests that nepheloid layers may not be a primary mechanism for delivering terrigenous POM to the deeper waters of the basin during the rainy season. Rather, BNL may redistribute marine-derived POM from shallow waters to the Basin's interior by providing ballast materials, particularly during episodic events driven by wind and precipitation. Though we have determined that nepheloid layers play an important role in the seaward transport of particulate material in the Cariaco Basin, their composition and temporal variability have not been fully characterized. This is critical to understand lateral particle transport, since nepheloid layers constitute a significant source of sediment to the deep Cariaco Basin.

Lorenzoni, Laura; Thunell, Robert C.; Benitez-Nelson, Claudia R.; Hollander, David; Martinez, Nahysa; Tappa, Eric; Varela, Ramón; Astor, Yrene; Muller-Karger, Frank E.

2009-12-01

356

The importance of subsurface nepheloid layers in transport and delivery of sediments to the eastern Cariaco Basin, Venezuela  

Microsoft Academic Search

Optical transmissometer measurements were coupled with particulate organic matter (POM) observations to understand suspended sediment composition and distribution in the eastern Cariaco Basin during the rainy seasons of September 2003 and 2006. Our results suggest that nepheloid layers originating at the mouth of small mountainous rivers discharging into the eastern Basin are a major delivery mechanism of terrigenous sediments to

Laura Lorenzoni; Robert C Thunell; Claudia R. Benitez-Nelson; David Hollander; Nahysa Martinez; Eric Tappa; Ramón Varela; Yrene Astor; Frank E. Muller-Karger

2009-01-01

357

GPS estimate of relative motion between the Caribbean and South American plates, and geologic implications for Trinidad and Venezuela  

Microsoft Academic Search

Global Positioning System (GPS) data from eight sites on the Caribbean plate and five sites on the South American plate were inverted to derive an angular velocity vector describing present-day relative plate motion. Both the Caribbean and South American velocity data fit rigid-plate models to within ±1 2 mm\\/yr, the GPS velocity uncertainty. The Caribbean plate moves approximately due east

John C. Weber; Timothy H. Dixon; Charles Demets; William B. Ambeh; Pamela Jansma; Glen Mattioli; Jarir Saleh; Giovanni Sella; Roger Bilham; Omar Pérez

2001-01-01

358

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

USGS Publications Warehouse

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

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

1991-01-01

359

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

E-print Network

. 10 Sub-interval AP-1: core porosity versus log porosity. . . 3. 11 Sub-interval AP-2: core porosity versus log porosity. . . 30 3. 12 Sub-interval AP-3: core porosity versus log porosity. . 30 3. 13 Interval HH: core porosity versus log porosity... and completion intervals. 81 4. 27 Area LL3487: reservoir pressure history match. . . 83 4. 28 Area LL3487: oil production rate history match. . . . . . . 4. 29 Area LL3487: water production rate history match. . . . 83 84 4. 30 Area LL3487: gas production...

Rodriguez, Manuel Gregorio

2012-06-07

360

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

PubMed

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

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

2013-09-01

361

Assessing water salinity along River Limón and Caño San Miguel irrigation paleochannel (Maracaibo, Venezuela) as affected by the balance of soluble salts in alluvium soils  

NASA Astrophysics Data System (ADS)

The saline degradation of soils that are irrigated with brackish water is worrisome increasing worldwide, and it may further affect the salinity of fresh water in those streams flowing across. The problem that is caused by an increasing concentration of salts that are more soluble than gypsum depends on the quality of irrigation water, climatic aridity, and drainage limitations. All these conditions meet in the alluvium soils of River Limón basin that are crossed by Caño San Miguel irrigation paleochannel. River Limón's regulation by closing Manuelote and Tulé artificial reservoirs has diminished the input of water and sediments from flooding events, which exerted dilutive effects in the past. In addition, the balance of soluble salts in these soils has also registered further net accumulation during those extremely dry years happened before 2006, because the great dilution contribution of ombrogenic dammed water coming from rain has not been enough to compensate salts concentration generated by water evapotranspiration in those irrigated soils of the middle basin, particularly in the absence of superficial runoff and deep drainage. Considering those semi-arid climate conditions prevailing in the area (annual precipitation = 710 mm; potential evapotransporation = 2361 mm), it resulted that water analyses in River Limón showed a ten-fold increased maximum annual salinity concentration (March) along the stream; that is, an electric conductivity (Ce) of 0.37 dS•m-1 (at 25 °C) at Puente Carrasquero pumping station, where water for crop irrigation is subtracted, turns to 34.60 dS•m-1 (at 25 °C) at its base level in Puerto Mara, where it discharges to Lake Maracaibo. In addition, the quality of irrigation water from Caño San Miguel, which aggregates to those coming from River Limón at the pumping station located in Carrasquero just before running through the alluvium of this water stream, resulted pretty irregular. In short, it spanned form C1 to C4 soil salinization risk classes depending on the sampling location and time of the year. In short, the farther away the sampling point from the initial pumping location, the higher the concentration of salts is measured; and these are even ten-fold higher in March, that is, after the end of the dry season, just before new rain dissolves the generated salt efflorescence on the surrounding soil (maximum Ce=9740 dS/m at 25 °C). In conclusion, a balance of salts should be attached to the balance of water required to compensate crop evapotranspiration aiming to achieve a sustainable use of the agrosystem. This salts balance is assessed in terms of the quantity of water that is required to drain soil so that productivity would be retained.

Rodriguez, Raquel; Moreno, Juan; Hermosilla, Daphne; Gascó, Antonio

2013-04-01

362

Giant-toothed White Sharks and Wide-toothed Mako (Lamnidae) from the Venezuela Neogene: Their Role in the Caribbean, Shallow-water Fish Assemblage  

Microsoft Academic Search

The role of Neogene giant-toothed lamnid sharks in the Caribbean neritic fish assemblage is discussed based on predator-prey relationships in three different tropical paleoenvironments from the Lower Miocene to Lower Pliocene. New records of extinct giant-toothed white sharks Carcharodon megalodon (Agassiz), Carcharodon subarticulatus (Agassiz), and wide-toothed mako Isurus xiphodon (Agassiz) from coastal shallow waters, coastal upwelling, swampy, coastal lagoon, and

ORANGEL AGUILERA; DIONE RODRIGUES DE AGUILERA

363

A comparative analysis of the clotting and fibrinolytic activities of the snake venom (Bothrops atrox) from different geographical areas in Venezuela.  

PubMed

Venom constitution within the same snake species can present considerable geographical variations. Bothrops atrox venoms were obtained from adult snakes captured at different geographical locations: Parguasa (Bolívar state); Puerto Ayacucho 1, Serranía del Cuao and Puerto Ayacucho 2 (Amazon state). The coagulant and fibrinolytic activities of these venoms were compared. Amidolytic activity of crude snake venom was measured by a micromethod designed in our laboratory. Coagulant activity on plasma and fibrinogen due to thrombin-like activity in venoms was also determined. Crude snake venom fibrinolytic activity by the fibrin plate method was assayed. Chromatographic studies were developed on Protein-Pack 300 column. Polyacrylamide gel electrophoresis was carried out under reduced conditions. After SDS-PAGE of samples, the fibrin-zymography was tested on agarose-fibrin plates. The results demonstrated several differences among B. atrox venoms from different geographical areas. Chromatograms and SDS-PAGE profiles indicated that venoms from the same species presented differences in the molecular mass of their components. The procoagulant activity depended on the utilized method (amidolytic versus clotting). Parguasa and Puerto Ayacucho 2 venoms presented procoagulant activity for both methods. Furthermore, Parguasa venom had also the highest hemorrhagic activity and the lowest LD50. In relation to the fibrinolytic activity, Puerto Ayacucho 1 venom was the most active, equally for fibrin plates as for the amidolytic method (t-PA like). This venom had the lowest coagulant activity, which induced us to think that probably its procoagulant activity was interfered by its fibrinolytic activity. PMID:17045631

Salazar, Ana Maria; Rodriguez-Acosta, Alexis; Girón, Maria E; Aguilar, Irma; Guerrero, Belsy

2007-01-01

364

Si cycle in the Cariaco Basin, Venezuela: Seasonal variability in silicate availability and the Si:C:N composition of sinking particles  

NASA Astrophysics Data System (ADS)

A 9-year time series of water column and sediment trap measurements was used to examine silicon cycling within the anoxic Cariaco Basin. The dynamic hydrographic regime within Cariaco Basin results in strong seasonal changes in nutrient availability and the Si:C:N of sinking particles. Upwelling in early winter injects silicic acid (Si(OH)4= ) and nitrate (NO3-) rich waters into the photic zone which stimulates primary production and results in opal fluxes in excess of 4 mmol Si m-2 d-1. However, even during upwelling, surface waters tend to be depleted (<1 ?M) in both Si(OH)4= and NO3- as a result of rapid utilization. In most years, the upper water column during winter and spring is marked by Si(OH)4= :NO3- and Si* values of less than 1. This indicates that silicate limitation in Cariaco Basin is most severe during upwelling and may restrict diatom production. Conversely, during the summer and fall when upwelling is reduced, Si(OH)4= :NO3- ratios in the upper 50 m of the water column exceed 10, implying that nitrate rather than silicate is acting to limit production during this time of year. On average, sinking particles collected at 150-m depth in the Cariaco Basin have Si:C and Si:N values of 0.17 ± 0.01 and 1.14 ± 0.10, respectively. These ratios increase with depth to 400 m and then remain relatively constant, suggesting minimal selective removal of elements with remineralization in the anoxic portion of the water column. Similar depth-dependent changes in these ratios are seen in surface sediments from the basin. Seasonally, particulate Si:C and Si:N are highest during the early part of the year when upwelling is most intense, while both ratios decrease to their lowest values during summer and fall. The observed seasonal variability in these ratios is due to changes in both nutrient utilization by diatoms and the contribution of diatoms to the total phytoplankton. The high ratios during upwelling suggest enhanced export of Si relative to C and N during this time of year.

Thunell, Robert; Benitez-Nelson, Claudia; Muller-Karger, Frank; Lorenzoni, Laura; Fanning, Kent; Scranton, Mary; Varela, Ramon; Astor, Yrene

2008-12-01

365

3-D structural and seismic stratigraphic interpretation of the Guasare-Misoa Interval, VLE 196 Area, Block V, Lamar Field, Lake Maracaibo, Venezuela  

E-print Network

is the VLE 400 Fault which was interpreted as a left-lateral strike-slip reverse fault due to its behaviors as a reverse fault in cross sections and as a strike-slip fault in strike sections. The VLE 400 Fault subdivides the VLE 196 area into two main...

Arzuman, Sadun

2004-09-30

366

The common MTHFR C677T and A1298C variants are not associated with the risk of non-syndromic cleft lip\\/palate in northern Venezuela  

Microsoft Academic Search

Non-syndromic cleft lip with or without cleft palate (nsCL\\/P) is among the most common major birth defects, with complex inheritance involving multiple genes and environmental factors. Numerous studies of MTHFR, encoding methylenetetrahydrofolate reductase, which catalyzes the rate-limiting step of folic acid biosynthesis, have shown inconsistent association of two common hypomorphic allelic variants, C677T and A1298C, in nsCL\\/P patients and, in

Mehmet A. Sözen; Marie M. Tolarova; Richard A. Spritz

2009-01-01

367

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

E-print Network

Well VLE-708 Well VLE-720 Well VLE-743 Well VLE-768 Well VLE-1067 Well VLE-1069 Well VLE-1093 Page 140 144 152 157 163 173 187 APPENDIX B - CORE ANALYSIS (WELL VLE-720 AND VLE-339) Well VLE-720 Well VLE-339 197 197 205 APPENDIX C... Member Detailed Stratigraphic Column of Lamar Field Porosity Distribution Histogram (Well VLE-339) Porosity Distribution Histogram (Well VLE-720) Log Permeability Distribution Histogram (Well VLE-339) Log Permeability Distribution Histogram (Well VLE...

Padron Cabral, Ricardo Javier

2012-06-07

368

Controls on the composition of fluvial sands from a tropical weathering environment: sands of the Orinoco River drainage basin, Venezuela and Colombia  

USGS Publications Warehouse

On the alluvial plains of the western Llanos, storage of orogenically derived sediment allows time for substantial chemical weathering. Through reworking of the alluvial sequences, freshly eroded sediment is exchanged for older, compositionally more mature material. The chemically weathered component increases as rivers cross the Llanos, resulting in an increase in overall compositional maturity of bed-load sand away from the orogenic terranes. -from Authors

Johnsson, M.J.; Stallard, R.F.; Lundberg, N.

1991-01-01

369

Review of the genus popilius and preliminary phylogeny of Passalidae (Coleoptera)  

E-print Network

......................................................................... 102 Popilius sp. 3 Bolivia .............................................................................. 103 Popilius sp.4 Venezuela .......................................................................... 104 Popilius gibbosus... ......................................................................... 102 Popilius sp. 3 Bolivia .............................................................................. 103 Popilius sp.4 Venezuela .......................................................................... 104 Popilius gibbosus...

Gillogly, Alan Roy

2006-08-16

370

MONITOREO EPIDEMIOLÓGICO PARA Brucella abortus EN FINCAS DOBLE PROPÓSITO DEL MUNICIPIO MACHIQUES DE PERIJÁ, VENEZUELA. PARTE II: VALIDEZ Y SEGURIDAD DE LAS PRUEBAS ANILLO DE LA LECHE Y ROSA DE BENGALA Epidemiologic Surveillance System for Brucella abortus in Dual Purpose Farms from Machiques de Perijá County, Venezuela. Part Two: Validity and Accuracy of Ring Test and Rose Bengal Test  

Microsoft Academic Search

The performance of the following diagnostic tests: Milk Ring Test (MRT), Indirect Enzyme-linked Immunosorbent Assay (iELISA), Rose Bengal Test (RBT) and Competitive ELISA (cE- LISA) used for 5 years (2003-2007) in the epidemiological sur- veillance system for bovine brucellosis (Brucella abortus )i n Ma- chiques de Perijá County was evaluated. For this purpose, milk and sera samples previously assessed through

Alfredo Sánchez-Villalobos; Regino Villarroel-Neri; Ana Oviedo-Bustos; Gilberto Sandrea; Julio Boscán-Ocando; Roymi Pinto-Patiño; Francisco Pirela-Larrazábal; Luís Becerra-Ramírez; Edgar López

2009-01-01

371

Evaluation of antibacterial activity on different solvent extracts of Euphorbia caracasana Boiss and Euphorbia cotinifolia L. (Euphorbiaceae) collected in Venezuela (Evaluación de la actividad antibacteriana en extractos de diferentes solventes de Euphorbia caracasana Boiss y Euphorbia cotinifolia L. (Euphorbiaceae) recolectadas en Venezuela)  

Microsoft Academic Search

In the present investigation the evaluation of the antibacterial activity of Euphorbia caracasana Boiss and Euphorbia cotinifolia L. has been evaluated against Gram positive and Gram negative bacteria using the disc diffusion agar method. E. caracasana and E. cotinifolia leaves were extracted with isopropyl alcohol. These extracts, after concentration, were fractionated by column chromatography and selected fractions, based on their

Janne ROJAS; Judith VELASCO; Antonio MORALES; Tulia DÍAZ; Gina MECCIA

2008-01-01

372

The representation of the «other-woman» in the screens: filmic contents in television and co-education  

Microsoft Academic Search

RESUMEN La importancia de los Medios Audiovisuales en la educación de sus espectadores, entendida ésta como la influyente contribución que las representaciones del mundo de los primeros hacen a la construcción de las cosmovisiones e identidades de los segundos, es indudable en las sociedades actuales. Los omnipresentes «Mass Media» representan «la realidad», funcionando como fuentes de interpretaciones de todo lo

Jorge Belmonte Arocha; Silvia Guillamón Carrasco

373

La globalización y su relación con la contabilidad  

Microsoft Academic Search

Resumen En este artículo se presentan unos acercamientos iniciales sobre algunas de las tendencias argumentativas que se vienen desarrollando en torno de la globalización. Por razones metodológicas, las mismas se encuentran agrupadas en cuatro apartes, considerados como necesarios para el abordaje de este tipo de estudios; estos son: la necesidad de entender la globalización, a propósito de las interpretaciones históricas

Aída Patricia Calvo Villada

2007-01-01

374

Los testigos de Jehová y el consentimiento informado  

Microsoft Academic Search

RESUMEN Los testigos de Jehová son una joven asocia- ción religiosa mundial dirigida por Watchtower Society de Nueva York, cuyos preceptos es- tán fundamentados ad pedem literae en la Bi- blia, pero con interpretaciones originales y connotaciones sectarias. La prohibición a ser transfundidos es una norma propia, actualmente vigente y que los distingue, condicionando anta- gonismos con el área médica.

Pimentel Pérez; Hospital General de Zona; Calzada Benito Juárez

375

XXII CONGRESO LATINOAMERICANO DE HIDRÁULICA CIUDAD GUAYANA, VENEZUELA, OCTUBRE 2006 ESTIMACIÓN DEL COSTE MARGINAL DE OPORTUNIDAD DEL RECURSO MEDIANTE MODELOS HIDRO-ECONÓMICOS A ESCALA DE CUENCA. APLICACIÓN AL SISTEMA DEL RÍO MIJARES EN ESPAÑA  

Microsoft Academic Search

The European Water Framework Directive establishes a common water policy framework, emphasizing the aspects of water quality and economics. The WFD requires the recovery of the costs of water services, including environmental and resource costs. Resource cost is often related to the opportunity cost of an economically inefficient water allocation. This paper shows the application of a methodology and hydro-economic

Eduardo Álvarez Mendiola; Manuel Pulido Velázquez; Joaquín Andreu

376

Coastal Ecosystems of Latin America and the Caribbean. Objectives, Priorities and Activities of Unesco's COMAR Project for the Latin American and Caribbean Region, Caracas, Venezuela, 15-19 November 1982. Unesco Reports in Marine Science 24.  

ERIC Educational Resources Information Center

To further the knowledge of the resources of coastal ecosystems and the general lines along which they function, Unesco implemented a "Major Interregional Project on Research and Training Leading to the Integrated Management of Coastal Systems" (COMAR). In addition, a proposed regional cooperative program called the "Regional Project for Research…

United Nations Educational, Scientific, and Cultural Organization, Paris (France).

377

C. A. La Electricidad de Caracas: Feasibility-study definitional report. Arreciffs Units 1 through 5 repowering project, electric power generation expansion Venezuela thermal power plant. Export trade information  

SciTech Connect

C.A. La Electricidad de Caracas (E.de C.) is a private company which in 1991 served some 830,000 customers in an area of 4,160 square kilometers surrounding Caracas. A program is underway by E.de C. for upgrading equipment and expanding the capacity of several of its existing generating facilities. The Arrecifes repowering project will involve the addition of about 330 MW of new natural gas fired gas turbine generators and heat recovery steam generators (HRSGs) to five existing thermal power units built 30 to 40 years ago which have steam turbine generator sets of 26 to 41 MW each. The existing steam boilers will be removed. The limited but seemingly sufficient space available is to be a primary focus of the feasibility study.

Not Available

1991-05-01

378

Biochemical genetics of chromosome forms of Venezuelan spiny rats of the proechimys guairae and proechimys trinitatis superspecies  

Microsoft Academic Search

Spiny rats from Venezuela show an extensive karyotypic diversification (2n=24 to 2n=62) and little morphological differentiation. This study reports genetic distance, heterozygosity and polymorphism based upon 22 loci in semispecies and allospecies of the Proechimys guairae superspecies from N Central Venezuela, as compared with Proechimys urichi, a member of the Proechimys trinitatis superspecies from eastern Venezuela. Four chromosome forms of

M. Benado; M. Aguilera; O. A. Reig; F. J. Ayala

1979-01-01

379

The Establishment of an Operational Earthquake Forecasting System in Italy  

NASA Astrophysics Data System (ADS)

Just after the Mw 6.2 earthquake that hit L'Aquila, on April 6 2009, the Civil Protection nominated an International Commission on Earthquake Forecasting (ICEF) that paved the way to the development of the Operational Earthquake Forecasting (OEF), defined as the "procedures for gathering and disseminating authoritative information about the time dependence of seismic hazards to help communities prepare for potentially destructive earthquakes". In this paper we introduce the first official OEF system in Italy that has been developed by the new-born Centro di Pericolosità Sismica at the Istituto Nazionale di Geofisica e Vulcanologia. The system provides every day an update of the weekly probabilities of ground shaking over the whole Italian territory. In this presentation, we describe in detail the philosophy behind the system, the scientific details, and the output format that has been preliminary defined in agreement with Civil Protection. To our knowledge, this is the first operational system that fully satisfies the ICEF guidelines. Probably, the most sensitive issue is related to the communication of such a kind of message to the population. Acknowledging this inherent difficulty, in agreement with Civil Protection we are planning pilot tests to be carried out in few selected areas in Italy; the purpose of such tests is to check the effectiveness of the message and to receive feedbacks.

Marzocchi, Warner; Lombardi, Anna Maria; Casarotti, Emanuele

2014-05-01

380

Near-regional CMT and multiple-point source solution of the September 5, 2012, Nicoya, Costa Rica Mw 7.6 (GCMT) earthquake  

NASA Astrophysics Data System (ADS)

We use acceleration data from the Observatorio Vulcanologico y Sismologico, Universidad Nacional de Costa Rica (OVSICORI-UNA) and Laboratorio de Ingenieria Sismica, Universidad de Costa Rica (LIS-UCR) seismic network for the relocation and moment-tensor solution of the September 5, 2012, 14:42:03.35 UTC, Nicoya, Costa Rica earthquake (Mw 7.6 GCMT). Using different relocation methods we found a stable earthquake hypocenter, near the original OVSICORI-UNA location in the Nicoya Peninsula, NW Costa Rica at Lat 9.6943°N, Lon 85.5689°W, depth 15.3 km, associated with the subduction of the Cocos plate under Caribbean plate. Acceleration records at OVSICORI-UNA and LIS-UCR stations (94-171 km), at 0.03 < f < 0.06 Hz were used in the waveform inversion for a single-point centroid moment tensor (CMT). Using spatial grid search the centroid position was found at the depth of 30 km, situated at Lat 10.0559°N, Lon 85.4778°W, i.e. of about 41 km NNE from the epicenter. The centroid time is 14:42:18.89 UTC, i.e. 15.54 s later relative to the location-based origin time. The nodal plane (strike 318°, dip 27° and rake 115°) is the fault plane that agrees with the geometry of the subducted slab at Nicoya, NNW Costa Rica. Increasing the maximum studied frequency from 0.06 to 0.15 Hz, the multiple point source inversion model leads to two subevents. The first one was located near the centroid and the second subevent was situated 20 km along strike and 10 km down dip from the first subevent and 6 s later. The uncertainty of the source model was carefully examined using complementary inversion methods, viz the iterative deconvolution and non-negative least squares.

Quintero, Ronnie; Zahradník, Jiri; Sokos, Efthimios

2014-11-01

381

Jose Antonio Ramos Sucre y la modernidad poetica  

E-print Network

JOSE ANTONIO RAMOS SUCRE Y LA MODERNIDAD POETICA Tesis por WILLIAM SHELL WATSON Presentado a la Of icina de Estudios Graduados de Texas A&M University en cumplimiento parcial de los requisitos para obtener el grado de MAESTRIA EN ARTES... esteticas descritas en los manifiestos de Andre Bret6n y enumerados por criticos posteriores. La poesia de Ramos Sucre responde a la 6poca moderna con una expresi6n que todavia cuestiona el valor de las interpretaciones tradicionales de la realidad...

Watson, William Shell

2012-06-07

382

State of the Modern Information Professional, 1992-1993. An International View of the State of the Information Professional and the Information Profession in 1992-1993. FID Occasional Paper 4.  

ERIC Educational Resources Information Center

The following 14 papers are provided: (1) "Perfil del profesional de la informacion en Venezuela" with a synopsis in English: "Profile of the Information Professional in Venezuela" (A. D. Anton and M. S. de Arenas); (2) "The Modern Information Professional in the Caribbean Setting" (D. Douglas); (3) "Development of Information Professionals and…

International Federation for Information and Documentation, The Hague (Netherlands).

383

The politics of joint sovereign borrowing: The Venezuelan\\/Argentine Bono del Sur  

Microsoft Academic Search

This article investigates how credible commitment evolves when sovereign states borrow jointly. In 2006, Venezuela and Argentina issued a package of ‘joint’ sovereign bonds, which were later tradable separately. Despite the fact that Venezuela did not explicitly guarantee the Argentine component of the bond, this paper shows through a series of GARCH models that the financial markets have traded the

Lauren M. Phillips

2012-01-01

384

Sources of d15 N variability in sinking particulate nitrogen in the Cariaco  

E-print Network

Sources of d15 N variability in sinking particulate nitrogen in the Cariaco Basin, Venezuela, Venezuela a r t i c l e i n f o Keywords: Cariaco Basin Sinking particulate organic matter Nitrogen isotopes Nitrogen fixation Sediment traps Climate variability a b s t r a c t Ten years of monthly observations

Meyers, Steven D.

385

The Yanomami in the Face of Ethnocide. IWGIA Document 22.  

ERIC Educational Resources Information Center

Spread between Brazil and Venezuela, the Yanomami occupy a dense forest region on the borders of Guyana, the northern parts divided up by grassy savanna. The Parima plain which forms the frontier between Brazil and Venezuela constitutes both the geographic centre and the place of origin of today's communities. The linguistic affiliation of these…

Lizot, Jacques

386

Original article Sugar profiles and conductivity of stingless bee  

E-print Network

Original article Sugar profiles and conductivity of stingless bee honeys from Venezuela S Bogdanov and the conductivity of 42 stingless bee honey samples from Venezuela were determined. Three of the honey types were composition of stingless bee honeys has been studied occasionally. Nogueira-Neto (1953), Maurizio (1964

Boyer, Edmond

387

Structural resistance of reinforced concrete buildings under pyroclastic flows: a study of the Vesuvian area  

NASA Astrophysics Data System (ADS)

The analysis of the effects of pyroclastic flows on humans and on buildings represents the main tool to define the boundary of the most hazardous area around an active volcano such as Somma-Vesuvius. Estimation of the lateral pressure on buildings derived from analogies with the damages observed after a nuclear explosion [Valentine (1998) J. Volcanol. Geotherm. Res. 87, 117-140] lead to pressure values and/or structural resistance which are not realistic (too high). Recent evidence [Baxter (2000) Human and Structural Vulnerability Assessment for Emergency Planning in a Future Eruption of Vesuvius. Final Report EC Project ENV4-CT98-0699; Young et al. (1997) EOS, Trans. Am. Geophys. Union, 78, 401] have shown that beyond 2-3 km from the vent, even after a great eruption, resistance to collapse of buildings affected by a pyroclastic flow is still possible. Neri et al. [(2000) Numerical simulation of pyroclastic flows. In: Human and Human and Structural Vulnerability Assessment for Emergency Planning in a Future Eruption of Vesuvius. Final Report EC Project ENV4-CT98-0699], by means of a numerical model of a collapsing column, show that the peak overpressures of the pyroclastic flows range from 1 to 2 kPa at a distance from the vent of about 4-5 km, where important historical centres of the Vesuvian area are located. A detailed analysis of urban settlement of the area [Cherubini et al. (2001) Vulnerabilita' Sismica dell'Area Vesuviana. Gruppo Nazionale per la Difesa dai Terremoti, CNR, Roma] has shown that most of the people live in reinforced concrete (r.c.) structures, not designed to resist horizontal seismic actions. The present work is aimed at analyzing the collapse limit load of r.c. structures to horizontal pressure for different structural design typologies (strong aseismic, weak aseismic, strong non-aseismic, weak non-aseismic). The simulations performed have also taken into account the specific features of the r.c. structures of the area (local building practice). The limits of resistance for each typology, in case of regular and irregular buildings, are provided. Such limits of resistance are in good agreement with the literature data coming from collapse simulation of buildings under seismic actions.

Petrazzuoli, S. M.; Zuccaro, G.

2004-05-01

388

Macroseismic survey of the April 6, 2009 L’Aquila earthquake (central Italy)  

NASA Astrophysics Data System (ADS)

On April 6, 2009, at 01:33 GMT, central Italy has been hit by a strong earthquake (Ml 5.8, Mw 6.3) representing the mainshock of a seismic sequence of over 20.000 aftershocks recorded in about five months. The event, located in the inner of the Abruzzi region just a few kilometres SW of the town of L’Aquila, has produced destructions and heavy damage in a 30 km wide area and was felt in almost Italy, as far as the coasts of Slovenia, Croatia and Albania. In all, 308 people lost their lives. A macroseismic survey was carried out soon after the earthquake by the QUEST group (QUick Earthquake Survey Team) with the aim to define, for Civil Protection purposes, the damage scenario over a territory which is densely urbanised. Damage generally depended on the high vulnerability of the buildings both for problems related to the old age of the buildings - it is the case of the historical centre of l’Aquila - and to site effects, as in some quarters of the town and in the nearby villages. Rubble-stone and masonry buildings suffered heaviest damage - a lot of old small villages almost entirely collapsed - while reinforced concrete (RC) frame buildings generally experienced moderate structural damage except in particular condition. The macroseismic effects reached intensity IX-X MCS (Mercalli-Cancani-Sieberg scale) at Onna and Castelnuovo, while many others villages reached VIII-IX MCS, amongst which the historical centre of L’Aquila. This town was investigated in detail due to the striking difference of damage between the historical centre and the more recent surrounding areas. In all, more than 300 localities have been investigated (Galli and Camassi, 2009). The earthquake has also provoked effects on natural surroundings (EMERGEO WG, 2009). Two types of phenomena have been detected: (i) surface cracks mainly observed along previously mapped faults and (ii) slope instability processes, such as landslides and secondary fractures. The pattern of macroseismic effects looks like that of the 1461 event, which produced heavy damages in L’Aquila and destructions in the surrounding south-eastern areas. Historical sources report, also in this case, many aftershocks, some of them very strong. References EMERGEO Working Group. (2009): Rilievi geologici nell’area epicentrale della sequenza sismica dell’Aquilano del 6 aprile 2009. Quaderni di Geofisica, 70, pp. 1-55. Galli P. and Camassi R. (eds.), (2009): Rapporto sugli effetti del terremoto aquilano del 6 aprile 2009, Rapporto congiunto DPC-INGV, 12 pp. available on the web at http://portale.ingv.it/real-time-monitoring/quest/macrodef_sito.pdf

Camassi, R.; Azzaro, R.; Bernardini, F.; D'Amico, S.; Ercolani, E.; Rossi, A.; Tertulliani, A.; Vecchi, M.; Galli, P.

2009-12-01

389

Course title: Sustainable Development and Macroeconomics Lecturer: Dina Barbian, University of Erlangen-Nuremberg  

E-print Network

1 Course title: Sustainable Development and Macroeconomics Lecturer: Dina Barbian, University, Venezuela, Niger, Sudan, or Ethiopia) in consideration of sustainability principles. The student: 9-11.30 Introduction to the topic and the case studies Sustainable Development ­ Definition

390

Last update / Dernire mise jour: 7/07/2005 EU Member States Other countries (continued)  

E-print Network

Singapore 192 Vanuatu 188 Solomon Islands 86 Venezuela 177 Somalia 56 Viet Nam 96 South Africa 150 Virgin 204 Malawi 122 Dominica 169 Malaysia 109 Dominican Republic 144 Maldives 93 Ecuador 136 Mali 236 Egypt

De Cindio, Fiorella

391

19 CFR 12.105 - Definitions.  

Code of Federal Regulations, 2011 CFR

...listed in paragraph (b) of this section which is the product of a pre-Columbian Indian culture of Belize, Bolivia, Columbia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Panama, Peru, or Venezuela. (b)...

2011-04-01

392

19 CFR 12.105 - Definitions.  

Code of Federal Regulations, 2010 CFR

...listed in paragraph (b) of this section which is the product of a pre-Columbian Indian culture of Belize, Bolivia, Columbia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Panama, Peru, or Venezuela. (b)...

2010-04-01

393

Development Challenges in the Caribbean and Central America  

E-print Network

HONDURAS NICARAGUA PANAMACOSTA RICA CUBA HAITI DOMINICAN REPUBLIC BRAZILECUADOR VENEZUELA M E X I C OM E XAtlantic and Pacific oceans, as well as by its political and social complexity (see Chapter 27 in the present volume

Richner, Heinz

394

A new organization comprised of students and members of the Latin American community. VISIONS provides a forum for elaborating ideas and concepts relevant to Latin America through a  

E-print Network

are welcome to be part of VISIONS! We are seeking an array of arti- cles concerned with politics, economics Cuba Through the Eyes of 6 Upcoming Events 7 Venezuela...A Good Neighbor? Hugo Chavez and Mohammad

Machery, Edouard

395

76 FR 41957 - Proposed Revisions to the Export Administration Regulations (EAR): Control of Items the President...  

Federal Register 2010, 2011, 2012, 2013

...North Korea, Sierra Leone, Somalia, Sudan, Sri Lanka, Syria, Venezuela, Vietnam...North Korea, Sierra Leone, Somalia, or Sudan, except 0A606.y...North Korea, Sierra Leone, Somalia, or Sudan, except...

2011-07-15

396

BREAKDOWN OR BREAKTHROUGH? The Copenhagen Accord  

E-print Network

by consensus, despite the objections of Venezuela, Sudan, Cuba, Nicaragua and Bolivia. All other countries critical credibility to the commitments to curb emissions made by China, India, Brazil, South Africa, Korea

397

CURRICULUM VITAE VLADIMIR V. KISIL  

E-print Network

and Operator Theory, Caracas (Venezuela) 1994 Symposium on Computer Simulation and Artificial Intelligence, M Conference on Computer Simulation, Universidad Panameri- cano (Mexico) 1996 Special Section Moments analysis, physics, and combi- natorics; mathematical simulation of natural and social processes. EMPLOYMENT

Haase, Markus

398

(Happy 300th Birthday Ben Franklin!)  

E-print Network

of aridity are complex but 2 major ones Trade winds from SE blocked by Andes Cold water coast due to S grasses in Ecuador and Venezuela) and puna (short grasses mostly in Peru and Bolivia) · Soils ­ many

Lopez-Carr, David

399

PANTONE 295 PANTONE black tiro Universidad  

E-print Network

://www.postgrado.usb.ve Apartado 89000. Caracas 1080 - Venezuela Perfil del egresado El egresado de este Programa estará en docente o autoridades de una Universidad de reconocido prestigio. Comprobante de pago del arancel de

Vásquez, Carlos

400

Experimental study of Morichal heavy oil recovery using combined steam and propane injection  

E-print Network

with steam (for the purpose of increasing steam recovery efficiency) are being evaluated. An experimental study has been performed to investigate the effect of combined steam and propane injection on recovery of heavy oil from the Morichal field, Venezuela...

Goite Marcano, Jose Gregorio

2012-06-07

401

Experimental study of enhancement of injectivity and in-situ oil upgrading by steam-propane injection for the Hamaca heavy oil field  

E-print Network

Experiments were conducted to study the feasibility of using propane as a steam additive to accelerate oil production and improve steam injectivity in the Hamaca field, Venezuela. The experiments utilized a vertical injection cell into which a...

Rivero Diaz, Jose Antonio

2012-06-07

402

Strategies of Educational Decentralization: Key Questions and Core Issues.  

ERIC Educational Resources Information Center

Explains key issues and forces that shape organization and management strategies of educational decentralization, using examples from Colombia, Venezuela, Argentina, Nicaragua, and Spain. Core decentralization issues include national and regional goals, planning, political stress, resource distribution, infrastructure development, and job…

Hanson, E. Mark

1998-01-01

403

Latin America: Translations No. 13.  

National Technical Information Service (NTIS)

Contents: Inter-American Affairs- Communist parties of Ecuador and Venezuela hold meeting; Peruvian view of Latin American revolution. Bolivia- Bolivian guerrilla situation analyzed. Brazil- A railroad policy for Northeastern Brazil; Ferryboat hastens rai...

1968-01-01

404

Synchronous interhemispheric Holocene climate trends in the tropical Andes  

E-print Network

Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA 15260; c Department. Venezuela | Bolivia | Caribbean | El Niño-Southern Oscillation | Milankovitch Variations in solar insolation

Vuille, Mathias

405

PRESS RELEASE I PARIS I 24 AOUT 2014 Tropical glaciers have responded to episodes of cooling in Greenland and the Antarctic  

E-print Network

to retreat, the frontal moraines are no longer protected by the ice, and a sort of 'geological chronometer cosmic rays (2). Around twenty glaciers in Venezuela, Peru, Bolivia and northern Argentina had already

van Tiggelen, Bart

406

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. 12, PAGES 30,82130,835, DECEMBER 10, 2001 Upper-mantle S-velocity structure of central and western South  

E-print Network

to be correlated with tectonic and geologic domains. SA99 shows high lithospheric S-velocities for the PrecambrianAmericanPrecambrianshieldsarefoundinBrazil, Venezuela, Guyana, Surinam and French Guiana, with edges in Bolivia and Colombia. The shield regions

van der Lee, Suzan

407

Gomatriaux / Geomaterials (Mtallognie / Ore deposits)  

E-print Network

-bearing quartz veins from the El Callao district (Guyana Shield, Venezuela) are filled with several comb quartz), sur- rounded by sedimentary (El Callao formation) and volcano-sedimentary units (Cicapra and Yuruari

Paris-Sud XI, Université de

408

19 CFR 12.105 - Definitions.  

...paragraph (b) of this section which is the product of a pre-Columbian Indian culture of Belize, Bolivia, Columbia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Panama, Peru, or Venezuela....

2014-04-01

409

19 CFR 12.105 - Definitions.  

Code of Federal Regulations, 2013 CFR

...paragraph (b) of this section which is the product of a pre-Columbian Indian culture of Belize, Bolivia, Columbia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Panama, Peru, or Venezuela....

2013-04-01

410

19 CFR 12.105 - Definitions.  

Code of Federal Regulations, 2012 CFR

...paragraph (b) of this section which is the product of a pre-Columbian Indian culture of Belize, Bolivia, Columbia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Panama, Peru, or Venezuela....

2012-04-01

411

Molecular and Biochemical Parasitology, 42 (1990) 175-188 175 MOLBIO 01383  

E-print Network

, Venezuela, Colombia and Costa Rica. Comparison of the patterns of digested kDNA on acrylamide gels led in insects, culture or animals may result in artificial selection of parasites from the original population

Simpson, Larry

412

Blue Spring State Park Immunization  

E-print Network

: Argentina Bangladesh Bolivia Brazil Burkina Faso Chile China Colombia Costa Rica Ecuador France Honduras September 23, 2013 #12;Korea Venezuela Manners and Culture Q: Why doesn't UF have more parking lots? A

Pilyugin, Sergei S.

413

The role of piscivores in a species-rich tropical river  

E-print Network

to anthropogenic impacts. In this dissertation, I endeavored to broaden our understanding of complex ecosystems through research conducted on the Cinaruco River, a floodplain river in Venezuela, with specific emphasis on how a human-induced perturbation...

Layman, Craig Anthony

2004-11-15

414

772 -XIV Encuentro de Latinoamericanistas Espaoles JUAN VICENTE GMEZ Y LA  

E-print Network

TIEMPO: APORTACI�N DE VENEZUELA AL LENGUAJE NEOCOLONIAL Alberto Darias Príncipe Universidad de La Laguna no poseemos, como si el desarrollo material de los pueblos se alcanzara por saltos y no estuviera sujeto a las

Paris-Sud XI, Université de

415

Productive Aging: A Question of Role.  

ERIC Educational Resources Information Center

Includes "The Paradox of Productive Aging" (Sicker); "Beyond Productive Aging" (Riley, Riley); "Changing Concepts; Visionary or Short-Sighted" (Holstein); "Making Aging Meaningful" (Glanz, Neikrug); and "Perspectives on Productive Aging from Austria, Bolivia, Denmark, Finland, Japan, Venezuela." (JOW)

Sicker, Martin; And Others

1994-01-01

416

Undergraduate Research Opportunities Program A Unit of the University System of Georgia An Equal Education and Employment Opportunity Institution  

E-print Network

of Congenital Bicuspid Aortic Valve Fluid Dynamics Mentor: Dr. Ajit Yoganathan, BME Ivan Allen College Naihobe Gonzalez, EIA University Education Expansion in Venezuela and Labor Market Outcomes: What Can We Learn from

Gaucher, Eric

417

17 CFR 240.3a12-8 - Exemption for designated foreign government securities for purposes of futures trading.  

Code of Federal Regulations, 2010 CFR

...of Spain; (xvi) The United Mexican States; (xvii) The Federative Republic of Brazil; (xviii) The Republic of Argentina; (xix) The Republic of Venezuela; (xx) The Kingdom of Belgium; or (xxi) The Kingdom of Sweden. (2)...

2010-04-01

418

17 CFR 240.3a12-8 - Exemption for designated foreign government securities for purposes of futures trading.  

Code of Federal Regulations, 2011 CFR

...of Spain; (xvi) The United Mexican States; (xvii) The Federative Republic of Brazil; (xviii) The Republic of Argentina; (xix) The Republic of Venezuela; (xx) The Kingdom of Belgium; or (xxi) The Kingdom of Sweden. (2)...

2011-04-01

419

1 Revised September 21, 2013 School of Education  

E-print Network

and Venezuela." Pp. 181-212 in Economic Development Strategies and the Evolution of Violence in Latin America Baby Books to Change New Mothers' Attitudes About Corporal Punishment." Child Abuse & Neglect, 36

Loudon, Catherine

420

7 CFR 319.56-21 - Okra from certain countries.  

Code of Federal Regulations, 2013 CFR

...AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-21 Okra from certain countries. Okra from Brazil, Colombia, Ecuador, Guyana, Mexico, Peru, Suriname, Venezuela, and the West Indies may be imported into the...

2013-01-01

421

7 CFR 319.56-21 - Okra from certain countries.  

Code of Federal Regulations, 2012 CFR

...AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-21 Okra from certain countries. Okra from Brazil, Colombia, Ecuador, Guyana, Mexico, Peru, Suriname, Venezuela, and the West Indies may be imported into the...

2012-01-01

422

7 CFR 319.56-21 - Okra from certain countries.  

...AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-21 Okra from certain countries. Okra from Brazil, Colombia, Ecuador, Guyana, Mexico, Peru, Suriname, Venezuela, and the West Indies may be imported into the...

2014-01-01

423

7 CFR 319.56-21 - Okra from certain countries.  

Code of Federal Regulations, 2011 CFR

...AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-21 Okra from certain countries. Okra from Brazil, Colombia, Ecuador, Guyana, Mexico, Peru, Suriname, Venezuela, and the West Indies may be imported into the...

2011-01-01

424

CAB International 2008. Ecohydrology: Processes, Models and Case Studies (eds Harper et al.) 207  

E-print Network

- tunately, large portions of Earth's major tropical river basins retain more or less natural hydrological)b Countries traverseda Amazon 6144 6300 Brazil, Peru, Bolivia, Colombia, Ecuador, Venezuela, Guyana Congo 3807

McClain, Michael

425

User's guide to the Venezuelan macrofinancial model  

E-print Network

This paper presents a user's guide and documentation for a macrofinancial model of Venezuela. This model was developed under a DOE International Affairs Division grant (contract no. EX-76-A-01-2295) for the project, "A ...

Aliana, Simon

1981-01-01

426

75 FR 20656 - Bureau of Educational and Cultural Affairs (ECA) Request for Grant Proposals: smART Power: Visual...  

Federal Register 2010, 2011, 2012, 2013

...State Department regional experts and ECA program officers in attendance. In the event a personal briefing session is not possible...projects may take place include Egypt, Venezuela, Indonesia, Malaysia, Thailand, Syria and Russia. These are examples for...

2010-04-20

427

NECESIDAD DE DESINFESTAR LA SEMILLA CORTADA DE PAPA EN LA ZONA ALTA DEL ESTADO TRUJILLO  

Microsoft Academic Search

Effect of cut potato seed decontamination in the highlands region of Trujillo State, Venezuela The efficiency of potato seed, cv. Granola, was evaluated in the highland of Trujillo State (2.400 m above sea level), Venezuela. Complete and cut tubers of 30-50 mm diameter and 50-70 g weight were decontaminated or not using cooper oxychloride and Zined fungicides, a week before

NOTA TÉCNICA; Héctor M. Coraspe-León; Freddy Montero; Carlos Alvarado; Eduardo Ortega

2002-01-01

428

NOTA TÉCNICA NECESIDAD DE DESINFESTAR LA SEMILLA CORTADA DE PAPA EN LA ZONA ALTA DEL ESTADO TRUJILLO  

Microsoft Academic Search

Effect of cut potato seed decontamination in the highlands region of Trujillo State, Venezuela The efficiency of potato seed, cv. Granola, was evaluated in the highland of Trujillo State (2.400 m above sea level), Venezuela. Complete and cut tubers of 30-50 mm diameter and 50-70 g weight were decontaminated or not using cooper oxychloride and Zined fungicides, a week before

Héctor M. Coraspe-León; Freddy Montero; Carlos Alvarado; Eduardo Ortega

429

The Influence of Breed and Temperament on Circulating Concentrations of Insulin-like Growth Factor-I (IGF-I) and Its Relationship to Feed Efficiency in Beef Cattle  

E-print Network

by Riley et al., (2007). Romosinuano cattle were imported as embryos from the Centro Agronomico Tropical de Investigacion y Ensenanza (CATIE) in Turrialba, Costa Rica, and from purebred breeders in Venezuela during the 1990s. The STARS Brahman herd... by Riley et al., (2007). Romosinuano cattle were imported as embryos from the Centro Agronomico Tropical de Investigacion y Ensenanza (CATIE) in Turrialba, Costa Rica, and from purebred breeders in Venezuela during the 1990s. The STARS Brahman herd...

Caldwell, Lisa

2010-07-14

430

Organochlorine Pesticide Contamination and its Potential Effects on Eggshell Characteristics of Dickcissels (Spiza americana)  

Microsoft Academic Search

Dickcissels (Spiza americana) are small, sparrow-like songbirds that nest in grasslands in the U.S. and winter in Venezuela. Fanners in Venezuela intentionally spray dickcissel flocks with organochlorine (DC) and other illegal pesticides in an attempt to kill them when they feed in both rice and sorghum fields. Previous studies have shown that organochlorine (DC) pesticide' contaminants (e.g., DDT) have significantly

BridgetWall

2008-01-01

431

Venezuelan Dam tests builder's skills  

SciTech Connect

Given half a chance, Venezuela's Macagua II hydroelectric project would have been finished by now. Handed less than half a chance by the cash-strapped owner, the builder of this nearly $1-billion, 2,540-Mw power development has pushed the project to the 80% complete mark anyway. This article summarizes the status of their project in terms of construction progress, financing, and socio-economic factors in Venezuela.

Stussman, H.B.

1994-01-03

432

IMPORT AND EXPORT REQUIREMENTS AND PROCEDURES____________  

E-print Network

main objective of this paper is to present a general information on the issues involved in exporting and importing fresh vegetables from Venezuela to United States or vice versa. This paper provides an easy manual to be used for understanding the procedures and regulations established in both countries for importing and exporting vegetables. Also, it offers an economic study of the export of green pepper from Venezuela to United States. The Venezuelan population is 23.9 million and a growing population of 1.56 % (CIA, 2001). Venezuela is located in South America continent. Its extraordinary geographic location and closeness to Miami Beach, a United States port, lets Venezuela keep an important market opportunity for exportingiii and importing products from United States, as well as with European and African markets. The Venezuelan tropical climate permits Venezuela to grow fresh vegetables without inconvenient temperatures. The United States population is 278.05 million people and a growing population of 0.9 % (CIA, 2001). The United States is located in the entire

Venezuela-united States; Jose I. Lanz P; Lanz Jose I_________

433

New Neotropical species of Chimarra (Trichoptera, Philopotamidae)  

PubMed Central

Abstract Ten new Neotropical species of Chimarra are described in the subgenera Chimarra, Chimarrita, and Otarrha. New species in the subgenus Chimarra include, in the Chimarra ortiziana group: Chimarra calori sp. n. (southeastern Brazil) and Chimarra onchyrhina sp. n. (Venezuela); in the Chimarra picea group: Chimarra inchoata sp. n. (Venezuela), Chimarra nicehuh sp. n. (Venezuela), and Chimarra sunima sp. n. (Colombia); and in the Chimarra poolei group: Chimarra cauca sp. n. (Colombia) and Chimarra desirae sp. n. (Bolivia). New species in the subgenus Chimarrita include, in the Chimarra simpliciforma group: Chimarra curvipenis sp. n. (SE Brazil) and Chimarra latiforceps sp. n. (SE Brazil). A single new species in the subgenus Otarrha is also described: Chimarra soroa sp. n. (Cuba). Males and females for all of the new species are illustrated, except for Chimarra desirae, for which female specimens were unavailable. Additionally, the female of Chimarra (Chimarrita) camella, which was previously unknown, is illustrated. PMID:22573949

Blahnik, Roger J.; Holzenthal, Ralph W.

2012-01-01

434

New Constraints On The Caribbean-South America Plate Boundary From S Wave Receiver Functions  

NASA Astrophysics Data System (ADS)

BOLIVAR (Broadband Ocean-Land Investigation of Venezuela and the Antilles arc Region) was aimed at investigating the interplay between the lithospheric and asthenospheric mantle of the Caribbean and South America plates. We estimate lithospheric thickness from application of the S wave receiver function technique. This reveals lithospheric thinning from 95-105 km depth underneath the Guyana Shield in southern Venezuela to 60-75 km underneath the Caribbean Sea. We observe a comparable thinning on the passive margin transition in eastern Venezuela. Towards the west, the lithosphere-asthenosphere boundary (LAB) shallows to 80 km depth along a NE-SW trending structure bordering the Venezuelan Andes. In addition, the base of the lithosphere beneath the Maracaibo block in NW Venezuela is seen gently dipping towards the southwest. The observed lithospheric structure is consistent with established strike-slip tectonics along the northern boundary of South America. However, we find no evidence for southward subduction of the Caribbean plate as previously suggested. Instead, the boundary is better viewed as the combined motion of three lithospheric blocks: (1) the Caribbean and associated subduction in the Antilles, (2) South America, and (3) the Maracaibo block. The relatively sharp discontinuity in LAB beneath northern Venezuela leads to the conclusion that the Caribbean-South America plate boundary is (1) a structure of lithospheric scale, and (2) a continuous strike-slip plate boundary extending from NE Colombia to Trinidad in NE Venezuela along the Oca-San Sebastian-El Pilar fault zone. This boundary is overprinted in the west by northward translation of the Maracaibo block over the Caribbean.

Landes, M.; Pavlis, G. L.

2008-12-01

435

New species and new records of the hygropetric water beetle genus Oocyclus Sharp from South America (Coleoptera: Hydrophilidae).  

PubMed

Three new species of Oocyclus Sharp, 1882 are described from tropical South America: O. maluz sp. n. (Venezuela), O. miza sp. n. (Venezuela), and O. brunneus sp. n. (Bolivia). New distributional records are provided for O. andinus Short & García, O. coromoto Short & García (newly recorded from Suriname), O. floccus Short & García (newly recorded from Guyana and Suriname), O. iguazu (Oliva), O. meridensis Short & García, O. petra Short & García (newly recorded from Guyana and Suriname), O. trio Short & Kadosoe (newly recorded from Guyana), O. trujillo Short & García, and O. yubai Clarkson & Short (newly recorded from Paraguay). Updates to the keys of the Brazilian and Venezuelan Oocyclus species are provided. PMID:25112994

Short, Andrew Edward Z; Greene, Luke; Garcia, Mauricio

2013-01-01

436

Operational changes hike propane recovery  

SciTech Connect

By optimizing operational conditions, the Corpoven cryogenic turboexpander plant in eastern Venezuela increased its propane recovery to 95.2% from a design rate of 90% without freezing problems. Its monthly average has been 94%. This increase represents a benefit of approximately 1,000 b/d or $4 million/year of additional propane sales. The plant was designed to recover up to 90% of propane in the inlet gas stream with provisions for future expansion for recovery of 70% of the ethane. This future expansion for ethane recovery will depend primarily on the development of the eastern Venezuela petrochemical project.

Jimenez, G.H.

1989-01-16

437

Taking the pulse of the Ecuador subduction zone near a locked patch  

NASA Astrophysics Data System (ADS)

In Central Ecuador the Nazca Plate, with a major topographic feature, the Carnegie Ridge, is subducting beneath the North Andean Margin at a rate of about 5 cm/yr along a ~N80°E direction. Intense seismic swarms have been regularly observed in 1977, 1998, 2002, and 2005 but no large megathrust earthquake is known in this segment of the margin, south of the rupture zone of the great 1906 Mag 8.8 Ecuador-Colombia earthquake. In 2010, a week-long slow slip event (SSE) was documented beneath La Plata Island, located 40 km east of the trench, at about 8 km depth within a locked patch of the subduction interface. The equivalent moment magnitude (Mw) released during this SSE was in the range of 6.0-6.3. This event unleashed an intense microseismic activity along the plate interface located beneath La Plata Island. The focal mechanisms and the space-time occurrence of these earthquakes suggest that the stress perturbations related to the slow slip event trigger the seismicity (Vallée et al., 2013). This study suggests a posteriori that recurrent seismic swarms, like the 2005 sequence may have been triggered by large-magnitude slow slip events with equivalent magnitude up to 7.5. In order to better observe this microseismic activity associated with SSE we deployed a temporary seismic network (OSISEC for Observación SISmica en ECuador) for a 2 years period (from November 2011 to October 2013). Six broadband land seismometers equipped with Trillium compact sensors and 5 Ocean Bottom Seismometers (3 components Guralp CMG-40T and 1 High-Tech Inc. wideband hydrophone) complement the 3 permanent seismological stations of the national seismic network with an average distance between stations of about 25 km. Automatic and manual analyses of continuous data of the first year yielded 2800 earthquake locations. Hypocentral determinations were computed with the complete network including readings from OBS data. Specific velocity models for the OBS stations were derived from vertical seismic profiles to account for the sea bottom anomalous structures. The seismicity distribution shows an intense activity inland, mostly beneath the land stations where ancient faults have been identified, whereas offshore, the seismicity appears to be sparse in time and space. This distribution is partly due to a much lower detection magnitude threshold inland (about mag. 2) than offshore (about mag. 3.5). Hence we observe a seismic quiescence near the trench, which is probably related to the presence of a strong coupled interplate patch. Hypocenters clusters outlined major crustal faults on-land and active deformation within the subducting slab. Both interplate and intraslab seismic activities show strong lateral variations indicating changes in stress pattern over short wavelengths. This ongoing work will present a better-resolved shape of the shallower part of the plate interface through accurate location of interplate events.

Segovia, M.; Font, Y.; Regnier, M. M.; Charvis, P.; Galve, A.; Hello, Y. M.; Jarrín, P.; Oge, A.; Pazmiño, A.; Ruiz, M. C.

2013-12-01

438

Directrices para la Creacion del Centro Nacional de Informacion y Documentacion (Guidelines for the Creation of a National Information and Documentation Center).  

ERIC Educational Resources Information Center

This document discusses background information and guidelines for the creation of a national information and documentation center for the dissemination of scientific and technological information. The study first reports on information services in several other countries and the need for an information center in Venezuela; included are…

Menda Behrens, Eduardo

439

The Weekly Newsletter of the English Language Institute Volume 101, Issue 2  

E-print Network

Portugal Republic of Korea Russia Saudi Arabia South Korea Spain Sudan Taiwan Thailand Turkey USA Venezuela, you can raise your hand slightly so they see you and say, "Miss" for a young woman, "Ma'am," for an older woman, "Sir" for a man, or simply "Excuse me". In other dining norms, there's no rule about who

Pilyugin, Sergei S.

440

SPATIAL COMPETITION AND THE NEW GOVERNANCE FRAMEWORK IN MABIBI (MAPUTALAND)  

E-print Network

in South Africa, Benin, Mali, Brazil, Venezuela. Acknowledgements I would like to thank Prof. Mark Jury;ABSTRACT The evolution of the demarcation of the political territories in South Africa has resulted, MAPUTALAND, SOUTH AFRICA INTRODUCTION The aim of this paper is to discuss the link between spatial

Boyer, Edmond

441

Exponential increase of publications related to soil water repellency  

Microsoft Academic Search

Soil water repellency is much more wide-spread than formerly thought. During the last decades, it has been a topic of study for soil scientists and hydrologists in at least 21 States of the USA, in Canada, Australia, New Zealand, Mexico, Colombia, Chile, Congo, Nepal, India, Hong Kong, Taiwan, China, Ecuador, Venezuela, Brazil, Mali, Japan, Israel, Turkey, Egypt, South Africa, Germany,

Louis W. Dekker; Klaas Oostindie; Coen J. Ritsema

2005-01-01

442

Natural and anthropogenic C2 to C6 hydrocarbons in the central-eastern Venezuelan atmosphere during the rainy season  

Microsoft Academic Search

The levels of low molecular weight hydrocarbons were measured at pristine sites and rural locations affected by hydrocarbon emissions from oil and gas producing fields in Venezuela. At the clean sites, lower concentrations of C2 to C6 alkanes were observed, whereas, in comparison with remotes sites, very much higher levels were measured at the polluted sites. Alkenes present relatively high

Loreto Donoso; Rodrigo Romero; Alberto Rondón; Emmanuel Fernandez; Pedro Oyola; Eugenio Sanhueza

1996-01-01

443

New Discoveries of Devonian Vertebrates from South America, and implications for Gondwana–Euramerica contact  

Microsoft Academic Search

A new fossil fish fauna from western Venezuela provides the first South American Devonian record of antiarch and phyllolepid placoderms, and sarcopterygians including lungfishes, groups widely distributed on other continents. Endemic elements in the fish fauna indicate Gondwana affinities, and the age of the phyllolepid placoderm occurrence is consistent with a model of biotic dispersal between Gondwana and Euramerica near

Gavin C Young; John M Moody; Jhonny E Casas

2000-01-01

444

Lichenotheca Latinoamericana a museo botanico berolinensi edita, fasciculum tertium  

Microsoft Academic Search

Sipman, H. J. M.: Lichenotheca Latinoamericana a museo botanico berolinensi edita, fasciculum tertium (Lichenot