Falcon State Research Articles

Caracterización geomorfológica de las dunas longitudinales del Istmo de Médanos, estado Falcón, Venezuela

El trabajo analiza la geomorfología de dunas costeras longitudinales del Istmo de Médanos, costa noroccidental de Venezuela. La metodología consistió en consultas bibliográficas, cartográficas, fotogramétricas y satelitales, trabajos de campo y análisis sedimentológico. Los resultados indican que estas dunas están compuestas por arenas de grano fino en un 84.6%, muy bien seleccionadas en más del 60%, principalmente subangulares, con asimetría negativa predominante, distribución leptocurtica, y bajo contenido de carbonato de calcio cercano al 10%. Los datos sugieren que los sedimentos son de origen terrígeno y escasa distancia de transporte hasta el lugar de acumulación. Los vientos predominantes actuales son del noreste, con componentes direccionales secundarios que retrabajan los sedimentos generando dunas transversales, barcanas y longitudinales; las dunas longitudinales son paralelas a la dirección del viento y se presentan colonizadas por vegetación xerofítica favorecida por la inactividad de las mismas. Estas dunas se originaron probablemente por una conjunción de factores como: disponibilidad de sedimentos en una amplia llanura costera relacionada con un nivel marino regresivo, vientos fuertes y persistentes, orientación oblicua de la costa respecto a la dirección del viento, una topografía continental favorable adyacente a la playa, bajo condiciones climáticas distintas a las actuales.

Tourism from the perspective of the demand. Place of study: Paraguana peninsula - Venezuela

This article focuses on the analysis of the characteristics of touristic demand, which selects the peninsula of Paraguana Falcon State, Venezuela, as a destination. For this purpose, a descriptive study was performed, which methodology relied on the use of quantitative approach, from which some indicators associated with demand were measured. The data collection strategy corresponds to that used in the fieldwork design, as it was applied in a real empirical context, while analyzing the information appealed to the method of logical deductive reasoning from which conceptualizations and other characteristic features of the system under study were argued. The nature of the research design is at the same time transectional non-experimental being discarded the control or deliberate handling of the variable to consider at any stage of the research. The results of the analysis lead to the conclusion that there exist two distinct groups of tourists with similar characteristics (a recreation-oriented group and a shopping and business-oriented group). Additionally, a significant level of tourist satisfaction is evidenced, especially with regard to the natural attractions that the destination has.

Aloe en Venezuela: de la cadena de valor al distrito industrial

Desde la perspectiva del estudio de los conglomerados, se contrastaron las aportaciones teóricas acerca de los conglomerados y el funcionamiento y desempeño de la cadena del aloe en el Estado Falcón (Venezuela), partiendo de la hipótesis de que esta cadena ha seguido un patrón evolutivo sustentado en el legado histórico de recursos que han favorecido la siembra y explotación del aloe en el estado. Sin embargo, se considera un escaso aprovechamiento de este patrimonio como estrategia para conformar un eficiente y competitivo conglomerado agroindustrial. La investigación se sustenta en estudios realizados entre 2003 y 2007 en las zonas productoras del aloe. Se identifican en la cadena los elementos típicos de un conglomerado (proximidad geográfica, redes, innovación e institucionalidad) bajo un patrón organizativo que no promueve la consolidación del conglomerado. En la cadena del aloe no termina de crearse la atmósfera industrial necesaria para iniciar la districtualización de esta actividad productiva.

Stylosanthes falconensis (Leguminosae, Papilionoideae, Dalbergieae), a new species endemic to Venezuela

During a revision of Venezuelan species of Stylosanthes Sw., two quite distinct specimens were found. After a detailed survey of the literature and herbarium material, it was concluded that they belong to an undescribed species. The new species Stylosanthes falconensis Calles & Schultze-Kr. (belonging to section Styposanthes Vogel), endemic to the Sierra San Luis in the State of Falcon, is here described. An illustration is provided and the differences between the new taxon and Stylosanthes hamata (L.) Taub., a closely related species, are presented.

Nueva especie de <i>Mastigoproctus</i> Pocock, 1894 (Thelyphonida, Thelyphonidae) de Venezuela noroccidental

Una nueva especie del genero Mastigoproctus Pocock, 1894 es descrita para el estado Falcon, en el tramo occidental de la Cordillera de la Costa, Venezuela. Es la tercera especie del genero registrada para el pais, siendo el registro mas al norte del genero en el continente suramericano y el primero del orden para el estado Falcon.

Diagnosis of caseous lymphadenitis by ELISA in naturally infected goats from Venezuela

Due to the absence of previous reports, the goal of this work was to detect caseous lymphadenitis (CLA) in goat flocks from Venezuela using an indirect immunoenzymatic assay (ELISA). Eighteen farms were randomly selected in Falcon State, North-Western Venezuela. Blood samples were taken from 259 goats, 65 of them with abscesses. Experimental inoculations were made to healthy kids with 0.5 mL inocula containing 4.7 × 10 5 of Corynebacterium pseudotuberculosis to observe the kinetics of antibody response. Immunoenzymatic assays were carried out using exotoxin of C. pseudotuberculosis as antigen. Antibody response in experimentally inoculated animals was detected 2 weeks after infection. Of 259 field goat sera, 55.98% were positive by ELISA. Of 65 goats with abscesses, 67.69% had CLA demonstrated by bacteriological methods; from these, 72.73% showed antibodies by ELISA. Of the remaining goats negative to CLA, 47.62% had antibodies by ELISA. Sensitivity was calculated in 72.73% and specificity in 67.74%. The immunoenzymatic assay applied in this research could be useful to detect CLA in naturally infected goat flocks from Venezuela.

Nuevo Rowlandius Reddell & Cokendolpher, 1995 (Schizomida: Hubbardiidae) de la Sierra San Luis, Venezuela noroccidental

Se describe un nuevo esquizómido del género Rowlandius Reddell & Cokendolpher, 1995, proveniente de la Sierra de San Luis, Estado Falcón, en Venezuela noroccidental. Rowlandius arduus sp. n. se caracteriza por el dedo móvil del quelícero con un diminuto diente subdistal, una débil eminencia dorsoposterior en el segmento abdominal XII del macho y espermatecas constituidas por dos pares de lóbulos largos y sinuosos, tenuemente quitinizados, sin bulbo terminal notable. Su asignación al género Rowlandius es tentativa, pues posee varios caracteres que no concuerdan plenamente con el mismo, sin embargo la carencia de caracteres sinapomórficos limita su asignación a otro género. Este es el primer registro del género para Venezuela y la tercera especie suramericana conocida.

North American Glyptodontines (Xenarthra, Mammalia) in the Upper Pleistocene of northern South America

The Glyptodontidae is one of the most conspicuous groups in the Pleistocene megafauna of the Americas. The Glyptodontinae were involved in the Great American Biotic Interchange (GABI) and their earliest records in North America are about 3.9 Ma, suggesting an earlier formation of the Panamanian landbridge. Taxonomically it is possible to recognize two Pleistocene genera of Glyptodontinae:Glyptodon (ca. 1.8 – 0.008 Ma), restricted to South America, andGlyptotherium (ca. 2.6 – 0.009 Ma), including records in both North and Central America. Here we present the first report of the genusGlyptotherium in South America, from the Late Pleistocene of several fossil localities in Falcon State, northwestern Venezuela. A comparative analysis of the material, represented by cranial and postcranial parts, including the dorsal carapace and caudal rings, suggests a close affinity withGlyptotherium cylindricum (Late Pleistocene of Central Mexico). This occurrence in the latest Pleistocene of the northernmost region of South America Supports the bidirectional faunal migration during the GABI and the repeated re-immigration from North America of South American clades, as has been reported in other members of the Cingulata (e.g., Pampatheriidae).

Cetacean remains from the Neogene of northwestern Venezuela

Cetacean remains from two different stratigraphic units exposed in Falcon State, northwestern Venezuela, are described. The first record is derived from the Lower Miocene Cantaure Formation and the second from the Lower Pliocene Punta Gavilan Formation, The two specimens are identified as an indeterminate species of a platanistoid Squalodelphinidae, and an indeterminate cetothere or balaenopterid, respectively.

Micro-heterogeneity and molecular assembly of the haemagglutinins from the red algae Bryothamnion seaforthii and B. triquetrum from the Caribbean Sea

Haemagglutinins have been isolated from two red marine algae Bryothamnion seaforthii and B. triquetrum, which were harvested from the Caribbean Sea, Falcon State, Venezuela. The mass spectra of the haemagglutinins isolated from B. seaforthii showed five monomer peaks (9057.4–9088.8 Da) and those from B. triquetrum showed three peaks (8981.5–8990.2 Da). Isoelectric focusing, under denaturing conditions, gave rise to multiple bands for the haemagglutinins of both species but only one band was observed under native conditions. Gel permeation experiments suggest that the monomer haemagglutinins can readily associate to form dimers, trimers and tetramers. The haemagglutinins agglutinate papainized human A, B and O erythrocytes; the activity is inhibited by glycoconjugates, but not by simple sugars, and is maintained after heating to temperatures up to 90°C. The amino acid sequence of the haemagglutinin from B. seaforthii has been determined together with a partial sequence for that from B. triquetrum. The isolation, and some characterization, of haemagglutinins from B. seaforthii and B. triquetrum, collected from the Ceara coast of Brazil, have previously been reported. Some differences and similarities of these macromolecules obtained from the two different locations are discussed.

Human leukocyte antigen class I and MICA haplotypes in a multicase family withCladophialophora carrioniichromoblastomycosis

Previous studies carried out in an endemic semiarid region northwest of Venezuela at Falcon State have shown a prevalence of 15.4/1000 of chromoblastomycosis following traumatisms with xenophile vegetation infected with Cladophialophora carrionii. We performed high-resolution DNA typing of human leukocyte antigen (HLA)-A, -B and -C and major histocompatibility complex class I chain related gene A (MICA) alleles and segregation analysis in 49 members of one extended family with 12 affected individuals, who have lived for approximately 70 years in this endemic zone. None of the alleles, haplotypes or genotypes is shared by all the patients. No deviation from the expected HLA haplotype distribution or association of chromoblastomycosis with HLA-A, -B and -C haplotypes was observed. Further, a haplotype-sharing transmission/disequilibria testing of 11 nuclear families did not give enough evidence to claim linkage (P = 0.398), suggesting that genes located in the short arm of chromosome 6 may not be relevant in the immune response toward infection with C. carrionii in this Venezuelan endemic zone. Deleted MICA alleles on HLA-B*4802 haplotypes were present among several members of the extended family, but only two of them were affected.

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

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

Enterobius vermicularis infection in preschool and schoolchildren of six rural communities from a semiarid region of Venezuela: A clinical and epidemiological study

Abstract Between August 2001 and July 2002, a cross-sectional survey was conducted to investigate clinical and epidemiological data on pinworm infection among 427 preschool and primary school age children of six rural communities from the semiarid region of Falcon state, northwestern Venezuela. Children were evaluated clinically and parasitologically by the Graham method. Overall prevalence was high (63.23 %). Pinworm infection rates were not significantly different between sex or age, suggesting similar transmission pattern and risk conditions for all individuals. Among the clinical findings and children’s habits, only perianal itching, enuresis, bruxism, and finger sucking showed significant higher percentages in infected children than in uninfected. Of interest was that anal pruritus (odds ratio [OR], 2.441), finger sucking (OR, 1.901), lower socioeconomic levels (OR, 4.358) and high levels of overcrowding conditions (≥ 3 persons/room: OR, 1.878; ≥ 2 persons/bed: OR, 11.833) appeared to be significant factors associated with transmission and endemic maintenance of enterobiasis among student children in this semi-arid Venezuelan region.

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

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 levels. The studied population included individuals with a history of exposure (or related exposures) to Hg processes, and was comprised of 1159 individuals (65 children, 1094 adults) ages 0.58–79 years old, mean 36.63±12.4. Children's geometric mean U-Hg levels were 2.73 μg/g Creatinine (Ct) and in adults 2.55 μg/g Ct. The highest frequency of adults' occupations were shipyard workers (35.47%), dentists (23.5%), lab technicians (11.43%), dental employees 10.42% and miners (10.2%). Chemical laboratory technicians had the highest mean U-Hg (4.46 μg/g Ct). Mean U-Hg levels in female adults (3.45 μg/g Ct) were statistically superior to levels in male adults (2.15 μg/g Ct). Two of the 172 women in reproductive age, had U-Hg levels higher than 78 μg/g Ct. Individuals from Falcon State were found to have the highest mean U-Hg (4.53 μg/g Ct). U-Hg levels higher than permissible limits were found in only 2 states (Carabobo and Bolivar) with a total of 24 cases. Although the results of this investigation were highly variable, the findings can be used to examine circumstances which influence mercury toxicity trends, and possibly used in future studies working to identify Hg exposures.

FORAGING MODE OF THE RETICULATE COLLARED LIZARD, CROTAPHYTUS RETICULATUS

Abstract The reticulate collared lizard (Crotaphytus reticulatus) is a large, crotaphytid lizard restricted to the lower Rio Grande Valley of southern Texas and northern Mexico. Our objectives were to determine the foraging mode of this species and test predictions made by other investigators about foraging behavior. We conducted focal observations on 10 male and 10 female lizards in Falcon State Park, Starr County, Texas, to quantify the number of movements per minute (MPM), the proportion of time spent moving (PTM), and the proportion of attacks made on prey items while moving (PAM). We removed foraging movements followed by social displays from the data and recalculated and reanalyzed foraging activity values. With “display” movements removed, there was a significant difference between MPM values and PTM values for males and for the sexes combined, but there was no significant difference in MPM values or PTM values for females. The foraging measures calculated for C. reticulatus, with and without “disp...

Renovation for more reliability [oil refinery power system upgrade

Paraguana Refining Center (CRP) in Petroleos de Venezuela (PDVSA) is the largest oil-refining complex in the world, with a distillation capacity of 900000 bbl/d. It is located in the Paraguana Peninsula, Falcon State, Venezuela. CRP services two large refineries: Amuay and Cardon. The problem with the Amuay refinery's electricity supply is outlined. The construction of an IPP plant in the Peninsula offered a solution to the problem. The purpose and scope of the project is outlined. The upgrading project restored the reliability, operational flexibility, and equipment maintainability of the Amuay refinery power system, allowing a reasonable load growth for mid-term projects. Increasing the reliability of industrial services through upgrading also increased the reliability of the process plants associated. Automation of the control rooms has permitted efficient, secure, and reliable operation of the generation units, optimizing the power import from the IPP. Adequate planning of the work and detailed risk analyses are necessary to perform a project with an industrial facility in operation and no impact to the process plants involved.

Ocorrência de Batrachedra nuciferae Hodges (Lepidoptera: Coleophoridae) no Estado de São Paulo

Batrachedra nuciferae Hodges, uma praga do coqueiro, foi descrita originalmente em 1966 de exemplares coletados na Bahia. Em 1998, a espécie foi constatada nos estados de Anzoategui, Aragua e Falcón, na Venezuela. Neste trabalho é registrada pela primeira vez a ocorrência da espécie no estado de São Paulo. As lagartas abundam durante a estação seca podendo destruir a totalidade das flores masculinas dos cachos atacados.

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

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

Una nueva especie de rana arborícola (Amphibia: Hylidae: Hyla) de un bosque nublado del oeste de Venezuela

It is described a new species of treefrog of the genus Hyla, H. amicorum, from the Cerro Socopo, state of Falcon, western Venezuela. This new taxon can be differentiated from the congeners reported from Venezuela by the combination of characteristics as follow: small size (22.6 mm, in male), vestigial webbing between toes II and III, belly strongly areolated, skin dorsally smooth, vent covered totally by a skin fold, no pattern on dorsum, dentigerous processes of the vomer arranged forming a wide U, located slightly behind and between the choanae. Intrageneric relationships of this new species are obscure, but a close relationships with those groups of H. minuta or H. microcephala groups would not be discarded, nevertheless as long as show unique combination of morphological characteristics, suggesting probably a different phylogenetic origin.

Late quaternary marine deposits of the Paraguana Peninsula, state of falcon, northwestern Venezuela: Preliminary geological observations and neotectonic implications

Abstract Four marine terraces are identified on Paraguana at +80 m, +40–50 m, +15–20 m and +6 m, skirting the ‘inselberg’ of cerro Santa Ana. Besides the Holocene marine deposits, patches of correlative sediments are only associated with the two youngest terraces within a narrow strip along the seashore because older Quaternary marine terraces are mainly erosional surfaces that truncate the uppermost limestone of the Pliocene Paraguana formation. Diverse marine deposits are observed between seashore and +5–6 m: sand barriers, mud flats, salt flats, stromatolites mats, coquinas and coral reefs in living position. Some of these facies are undoubtfully Holocene, but some others proved to be older than the 14 C dating limit. Therefore, the latter ones should be ascribed to isotope-stage 5, but further sampling and dating are required to confirm their chronology. It is worth mentioning that probable stage-5 facies of Paraguana are as high as its worldwide undeformed equivalents, implying a certain tectonic stability during late Pleistocene. However, the assumption of a stable Paraguana block has to be modified since the existence of staircased marine terraces implies a certain amount of uplift, even if it is rather slow (≤ 0.8 mm/year).