Martinez Mendez D.,Francisco de Miranda National Experimental University |
Hernandez Valles R.,Francisco de Miranda National Experimental University |
Alvarado P.,Institute Biomedicina |
Mendoza M.,Institute Biomedicina
Revista Iberoamericana de Micologia | Year: 2013
Background: In 1984 the Venezuelan Work Groups in Mycology (VWGM) were created introducing an innovative approach to the study of the mycoses in Venezuela. Aim: To study the occurrence of the mycoses in Venezuela. Methods: Review the reported cases of mycoses by the newsletter Boletín Informativo Las Micosis en Venezuela (VWGM) from 1984 to 2010. Results: The data collected showed 36,968 reported cases of superficial mycoses, 1,989 of deep systemic cases, and 822 of localized mycoses. Pityriasis dermatophytosis was the most common superficial infection, and paracoccidioidomycosis and histoplasmosis the most frequent deep systemic infection. Chromoblastomycosis was the most frequently diagnosed subcutaneous infection. The data provided showed the distribution by geographical area for each of the fungal infections studied, which may help to establish the endemic areas. Discussion: Superficial mycosis is a public health problem due to its high morbidity and is probably responsible for some of the outbreaks in high-risk groups. Paracoccidioidomycosis and histoplasmosis were reported more often, which agrees with earlier reports prior to the formation of the VWGM. Cases of sporotrichosis and chromoblastomycosis in Venezuela can be considered unique due to the high number of cases. This study highlights the contribution of the VWGM to the behavior of the mycoses in Venezuela, its incidence, prevalence, and the recognition of these infections as a problem of public health importance. The VWGM should keep working in this endeavor, not only reporting new cases, but also unifying the clinical and epidemiological criteria, in order to properly monitor the evolving epidemiological changes reported in these types of infections. © 2012 Revista Iberoamericana de Micología.
Vucetich M.G.,Museo de La Plata |
Carlini A.A.,Museo de La Plata |
Aguilera O.,Francisco de Miranda National Experimental University |
Sanchez-Villagra M.R.,University of Zürich
Journal of Mammalian Evolution | Year: 2010
We report a new vertebrate assemblage from the Pliocene Vergel Member of the San Gregorio Formation in northwestern Venezuela, which includes Crocodylia and Testudines indet., toxodonts, at least four species of xenarthrans of the Dasypodidae, Pampatheriidae, Glyptodontidae and Megatheriidae, and rodents. The last are Cardiatherium, cf. Caviodon (Hydrochoeridae), Neoepiblema (Neoepiblemidae), and what is here described as a new genus of a low-crowned octodontoid. cf. Caviodon is the first cardiomyine for northern South America. The rodent assemblage resembles in its ecological composition those of the late Miocene (Huayquerian) from the "Mesopotamian" of Argentina and the Acre region in Brazil, with partially overlapping systematic composition. The stratigraphic position of the San Gregorio Formation and mammals other than caviomorphs suggest a late Pliocene age for these sediments, implying the endurance of rodent taxa beyond their biochron in southern South America. © 2010 Springer Science+Business Media, LLC.
Smith D.,Francisco de Miranda National Experimental University |
Graciano C.,National University of Colombia |
Martinez G.,Simon Bolivar University of Venezuela
Thin-Walled Structures | Year: 2014
Previous studies have demonstrated that the failure mechanism and energy absorption capacity of expanded metal tubes strongly depends on the orientation of the cells. This paper presents an experimental investigation on the collapse of concentric expanded metal tubes subjected to quasi-static axial compression. Square tubes with two different cell orientations are tested to failure, and the energy absorption characteristics are calculated. The results show that the combination of cell geometries lead to a complex buckling mode interaction, which enhances the energy absorption capacity of expanded metal tubes. © 2014 Elsevier Ltd.
Corzo O.,University of the East Venezuela |
Bracho N.,University of the East Venezuela |
Rodriguez J.,Francisco de Miranda National Experimental University
LWT - Food Science and Technology | Year: 2012
Application of the Peleg and Azuara etal. models for describing mass transfer during pile salting of goat sheets using different mixtures of NaCl, KCl, CaCl 2 and MgCl 2 was investigated The high coefficient of determination (R 2>0.97 and R 2>0.95 for Peleg and Azuara etal. models, respectively) and the modulus of mean relative errors (MRE<10% for both models) indicated the acceptability of both Peleg and Azuara etal. models for predicting both moisture loss and salt uptake. The equilibrium moisture and salt contents were estimated using Peleg rate constants and Azuara etal. model parameters. Equilibrium moisture (x w) and salt contents (x s) varied from 0.522 to 0.860g water/g db and from 0.311 to 0.352g NaCl/g db respectively. Multiple comparison of means showed that x w and x s predicted by the Peleg model were lower than those estimated by the Azuara etal. model. The values differed by 1.86-13.6% for x w and by 1.13-10.57% for x s. © 2011 Elsevier Ltd.
Soil compaction processes in a Vertisol under four handling conditions in Coro Plain, Falcón State, Venezuela [Procesos de compactación en un suelo Vertisol bajo cuatro condiciones de manejo en la llanura de Coro, Estado Falcón, Venezuela]
Reyes R. W.J.,Francisco de Miranda National Experimental University
Bioagro | Year: 2014
The study was conducted on soils classified as Vertisol, belonging to the Academic Support Unit "Ingeniero José Landaeta", Academic Unit of the Francisco de Miranda University, under four management conditions: fallow condition (C1), semi-permanent crop condition (C2), previous pasture conditions (C3), and intensely intervened areas (C4). Under each condition the soil compaction process was evaluated at 0-15 and 15-30 cm using physical, chemical and biological indicators. It was found no differences in the first layer for the management conditions, while in the second layer bulk density significantly increased for conditions of increased mechanical intervention. Likewise, principal component analysis discriminated two groups of soils: one under conditions of increased antropic disturbance (C2 and C4), and the other consisting of resting or less disturbed soils (C1 and C3); the first group was associated to greater variation in bulk density due to higher mechanical manipulation, while the second group was associated to improvements of organic matter content, attributed to the natural vegetation contributions.
Intestinal parasites of zoonotic importance in domiciliary canines of a rural village from Falcón state, Venezuela [Parásitos intestinales de importancia zoonótica en caninos domiciliarios de una población rural del estado Falcón, Venezuela]
Perfetti D.C.,Francisco de Miranda National Experimental University |
Moreno P.M.,Francisco de Miranda National Experimental University
Boletin de Malariologia y Salud Ambiental | Year: 2013
During September and December 2007, a total of 98 dogs (67 males and 31 females) with owner were surveyed in the rural community of La Peña, Falcon State, Venezuela. Parasitological examination was made by employing direct smear, Willis-Molloy (NaCl) and Faust (zinc sulphate) flotation methods, and Kinyoun staining. One or more parasitic species were found in 87 (88.78%) of the examined dogs. Monoparasitism was observed in 50.58% of the dogs, and multiparasitism with up to 2-3 parasitic species. Ancylostomids (45.92%), Toxocara sp. (35.76%) and Giardia sp. (14.29%) were the most prevalent intestinal parasites. There was no significant association between the prevalence of any intestinal parasites and canine age groups nor between sexes (P>0.05). The familys socioeconomic levels (Odds ratio [OR]= 1.02) and number of dogs per house (OR=1.16), and reasons for keeping dogs (OR=1,48) appeared to be significant factors associated with transmission and endemic maintenance of Ancylostomids and Toxocara sp., respectively, among canines in this Venezuelan region. Improvement of sociosanitary conditions and health promotion education are recommended in order to control these zoonotic parasites.
Clinical and epidemiological study of intestinal coccidioses in a rural population of a semiarid region from Falcon state, Venezuela [Estudio clínico-epidemiológico de coccidiosis intestinales en una población rural de región semiárida del estado Falcón, Venezuela]
Cazorla D.,Francisco de Miranda National Experimental University |
Acosta M.E.,Francisco de Miranda National Experimental University |
Morales P.,Francisco de Miranda National Experimental University
Investigacion Clinica (Venezuela) | Year: 2012
Although intestinal coccidioses caused by Cryptosporidium sp., Cystoisospora belli and Cyclospora cayetanensis are parasitic diseases of major clinical importance in Public Health, several clinical and epidemiological aspects of these diseases still remain unknown in Falcon state, Venezuela. A cross-sectional survey was conducted between June and October 2011, to investigate clinical and epidemiological data in 157 people (X ± S.D. = 21.28 ± 17 years-old) from Sabaneta, Falcón state, Venezuela. Symptoms associated with intestinal coccidioses were determined by means of anamnesis and clinical examination. Direct smear and Kinyoun staining were used to perform the parasitological diagnosis. The overall prevalence of intestinal parasites was 61.78% (97/157) and Blastocystis sp. was the most prevalent intestinal parasite (56.68%). Coccidioses prevalence was 26.11% (41/157) and among these, cyclosporiasis was the most prevalent with 24.2%. There were no statistically significant differences in the prevalence between sexes or ages (X2= 0.20; p=0.70 and X2=10.06; p= 0.44, respectively). Diarrhea and epigastralgia were the most common clinical findings, and the only ones significantly associated with intestinal coccidioses (p< 0.05). In the light of these results, it can be concluded that hand washing (OR= 1.93), bathing (OR= 2.78), keeping domestic animals (OR= 10.1) and their feeding with waste (OR= 6.58), are potential risk factors that appeared to be significantly related to the transmission and endemic maintenance of intestinal coccidioses.
Corona Lisboa J.L.,Francisco de Miranda National Experimental University
Revista Cubana de Investigaciones Biomedicas | Year: 2015
Determination of genetic sex takes place at the time of fecundation whereas differentiation of gonadal and genital sexes occurs during critical periods of embrionary life. The factors that modify the mechanisms of sex differentiation are varied and their anatomical and pathological, genetic and molecular study have attracted many researchers interested in this topic. The objective of the present article was to describe the genetic anomalies related to the development in sexual morphophysiology of mammals, starting from a deductive approach on the basis of reported research works on this topic. According to the information, it was concluded that anomalies of the chromosomal, gonadal and genital sex respond to a series of genetic alterations that involve a set of enzymatic cascades affecting the normal course of the sexual morphophysiological development of the animal. © 2015, Editorial Ciencias Medicas. All rights reserved.
Perez Gonzalez E.L.,Francisco de Miranda National Experimental University
Advances in Unsaturated Soils - Proceedings of the 1st Pan-American Conference on Unsaturated Soils, PanAmUNSAT 2013 | Year: 2013
Soil modeling process requires a large amount of high quality experimental data. However, products of these processes fail to be satisfactory in most cases. This is due primarily to nonlinear behavior that correlates different variables to be considered. This article presents a methodology to train surrogate models based on Support Vector Machines (SVM) using limited experimental data. Polynomial, Gaussian, and exponential radial basis function kernels were used for modeling. It has been proved that assembling the best models in a new one can surpass some of these individually. Several indicators were used to measure the model performance. An absolute relative error of 16% was reported during the use of the best ones. SVM offers a simple and reliable way in modeling the behavior of soils and can greatly enhance the capacity in soil mechanics laboratories in Latin America. © 2013 Taylor & Francis Group, London.
Cazorla Perfetti D.J.,Francisco de Miranda National Experimental University
Boletin de Malariologia y Salud Ambiental | Year: 2012
A revised and updated checklist of the centipedes (Myriapoda, Chilopoda) registered from Venezuela is shown. Up untill now, 90 centipede species and two subspecies have been recorded, grouped into 22 genus forming 11 families and four orders (Scutigeromorpha, Lithobiomorpha, Scolopendromorpha, Geophilomorpha). Of these, 68 (73,91%) species/subspecies appear to be considered as endemic. Medical relevance and research needs on the Venezuelan class Chilopoda, is discussed.