University of the East of Cuba

Santiago de Cuba, Cuba

University of the East of Cuba

Santiago de Cuba, Cuba

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Adrian T.-Q.,University of the East of Cuba | Rodolfo N.-G.,Institute Ecologia
Zootaxa | Year: 2012

The final stadium larva of Erythrodiplax bromeliicola Westfall is formally described and illustrated. The light brown scape and pedicel and creamy pale flagellum of the antenna, plus the abundant short, reddish, spiniform setae on the integument of the body surface and epiproct, comprise an exclusive combination of characters in the larva of E. bromeliicola. Information on larval habitat and a key for the larvae of the five Erythrodiplax species occurring in Cuba are provided. Details on morphological variation of an adult population from Cuba are also provided. Copyright © 2012 · Magnolia Press.

Martinez J.D.,Federal University of Itajubá | Martinez J.D.,Pontifical Bolivarian University | Silva Lora E.E.,Federal University of Itajubá | Andrade R.V.,Federal University of Itajubá | Jaen R.L.,University of the East of Cuba
Biomass and Bioenergy | Year: 2011

This work presents an experimental study of the gasification of a wood biomass in a moving bed downdraft reactor with two-air supply stages. This configuration is considered as primary method to improve the quality of the producer gas, regarding its tar reduction. By varying the air flow fed to the gasifier and the distribution of gasification air between stages (AR), being the controllable and measurable variables for this type of gasifiers, measuring the CO, CH4 and H2 gas concentrations and through a mass and energy balance, the gas yield and its power, the cold efficiency of the process and the equivalence ratio (ER), as well as other performance variables were calculated. The gasifier produces a combustible gas with a CO, CH4 and H2 concentrations of 19.04, 0.89 and 16.78% v respectively, at a total flow of air of 20 Nm3 h-1 and an AR of 80%. For these conditions, the low heating value of the gas was 4539 kJ Nm-3. Results from the calculation model show a useful gas power and cold efficiency around 40 kW and 68%, respectively. The resulting ER under the referred operation condition is around 0.40. The results suggested a considerable effect of the secondary stage over the reduction of the CH4 concentration which is associated with the decreases of the tar content in the produced gas. Under these conditions the biomass devolatilization in the pyrolysis zone gives much lighter compounds which are more easily cracked when the gas stream passes through the combustion zone. © 2011 Elsevier Ltd.

Mockey Coureaux I.O.,University of the East of Cuba | Manzano E.,National University of Tucuman
Energy for Sustainable Development | Year: 2013

Road lighting facilities operate for over half of a year but they are permanently subjected to adverse weather conditions and environmental pollution. The major cause of the loss of light is generally the accumulation of dirt on the luminaires (lamps and lighting fixtures).The severity of the loss (depreciation) depends on the nature and density of environmental pollution and the degree of protection of the luminaires against dust and water. This depreciation is compensated, beginning from the design stage, by over-sizing facilities and, throughout its lifetime, by maintenance programs. There are several ways of estimating depreciation. This paper is a review of the different sources of information and findings of major investigations conducted in recent times. There is strong evidence which indicates that luminaire depreciation could be based on the level of sealing of the luminaires and on environment pollution categories. Luminaires with IP6X degree protection are only slightly influenced by environment pollution. New generations of LED luminaires are built to conform to IP6 and this will probably soon be the standard for road and urban lighting luminaires. Even if these luminaires have a higher rate of lamp survival, an exterior cleaning operation is still necessary and the luminaire depreciation behaviour model will still be useful. It is important to select a convenient maintenance factor to compensate for depreciation and to reduce the number of installed fixtures or the amount of over sizing of lamp power, which significantly transcends the energy and environmental impact. © 2013 International Energy Initiative.

Speck-Planche A.,University of the East of Cuba | Kleandrova V.V.,Moscow State University of Food Production
Molecular Diversity | Year: 2012

Rational design of entry inhibitors is an active area for the discovery of new and effective anti-HIV agents. C-C Chemokine receptors represent key targets for the HIV entry process. Several of these proteins with features to be HIV co-receptors have not been sufficiently studied or used for the design of novel entry inhibitors. With the purpose to overcome this problem, we develop here a fragment-based approach for the design of multi-target inhibitors against four C-C chemokine receptors. This approach was focused on the construction of a multi-target QSAR discriminant model using a large and heterogeneous database of compounds and substructural descriptors for the classification and prediction of inhibitors for C-C chemokine receptors. The model correctly classified more than 89% of active and inactive compounds in both: training and prediction series. As principal advantage, this model permitted the automatic and fast extraction of fragments responsible for the inhibitory activity against the different C-C chemokine receptors under study and new molecular entities were suggested as possible versatile inhibitors for these proteins. © 2011 Springer Science+Business Media B.V.

Reyes J.B.,University of the East of Cuba | Shapiro M.,Escuela Superior de Fisica y Matematicas
Mathematical Methods in the Applied Sciences | Year: 2010

For a positive integer n let Cl0,n be the universal Clifford algebra with the signature (0,n). The name Clifford analysis is usually referred to the function theories for functions in the kernels of the two operators: the (Cliffordian) Cauchy- Riemann operator and the Dirac operator. For n = 2, Cl0,2 becomes the skew-field of Hamilton's quaternions for which the two operators are widely known: the Moisil-Théodoresco and the Fueter operators. We establish the precise relations between the Moisil-Théodoresco operator and the Dirac operator for Cl0,3. It turns out that the case of the Cauchy- Riemann operator for Cl0,3 and the Fueter operator is more sophisticated, and we describe the peculiarities emerging here. © 2009 John Wiley & Sons, Ltd.

Anaya-Sanchez H.,Jaume I University | Pons-Porrata A.,University of the East of Cuba | Berlanga-Llavori R.,Jaume I University
Pattern Recognition Letters | Year: 2010

In this paper, we introduce a new clustering algorithm for discovering and describing the topics comprised in a text collection. Our proposal relies on both the most probable term pairs generated from the collection and the estimation of the topic homogeneity associated to these pairs. Topics and their descriptions are generated from those term pairs whose support sets are homogeneous enough for representing collection topics. Experimental results obtained over three benchmark text collections demonstrate the effectiveness and utility of this new approach. © 2009.

Speck-Planche A.,University of the East of Cuba | Kleandrova V.V.,Moscow State University of Food Production | Rojas-Vargas J.A.,University of the East of Cuba
Molecular Diversity | Year: 2011

The increasing resistance of several phytopathogenic fungal species to the existing agrochemical fungicides has alarmed to the worldwide scientific community. There is no available methodology to predict in an efficient way if a new fungicide will have resistance risk due to fungal species which cause considerable crop losses. In an attempt to overcome this problem, a multi-resistance risk QSAR model, based on substructural descriptors was developed from a heterogeneous database of compounds. The purpose of this model is the classification, design, and prediction of agrochemical fungicides according to resistance risk categories. The QSAR model classified correctly 85.11% of the fungicides and the 85.07% of the inactive compounds in the training series, for an accuracy of 85.08%. In the prediction series, the percentages of correct classification were 85.71 and 86.55% for fungicides and inactive compounds, respectively, with an accuracy of 86.39%. Some fragments were extracted and their quantitative contributions to the fungicidal activity were calculated taking into consideration the different resistance risk categories for agrochemical fungicides. In the same way, some fragments present in molecules with fungicidal activity and with negative contributions were analyzed like structural alerts responsible of resistance risk. © 2011 Springer Science+Business Media B.V.

Portuondo I.P.,University of the East of Cuba
Revista Cubana de Salud Publica | Year: 2012

Introduction: Gram positive bacterium Bacillus cereus is widely distributed in the environment. This bacterium is responsible for two food poisoning syndromes (emetic and diarrheal) and also it has been related to other diseases such as endocarditis and endophthalmitis; therefore it is recognized as opportunist pathogen. Objective: to review the information about Bacillus cereus toxins and its connection with food poisoning, as well as to address others factors influencing this bacterium's virulence. Data sources: for collecting this information, search engines such as Google and Scirus. Reviewed articles included research articles, systematic reviews on this topic and free accessed book chapters, or requested from the authors. Data synthesis: the review delved into Knowledge on diarrheal and emetic toxins, clinical symptomatology and time of occurrence, as soon as foodstuffs involved in each syndrome. This helps the clinician to look for the causes of toxin infections. A general overview of Bacillus cereus microbiology and others factors that explain its virulence and other implications in the human health was given. Conclusions: the acquired knowledge shows that Bacillus cereus is one bacterium with clinical importance rather than a mere environmental pollutant.

Kleandrova V.V.,Moscow State University of Food Production | Speck-Planche A.,University of the East of Cuba
Frontiers in Bioscience - Elite | Year: 2013

The chemical risk assessment is determinant for the approval of any kind of chemical. Each aspect of chemical is taken into consideration for the new chemical legislation registration, evaluation, and authorization of chemicals (REACH). However, some improvements can be made in order to select and authorize a chemical. QSAR techniques have been used for the study of several kind of toxicological properties in order to realize a deeper study concerning to risk assessment. For this reason, this work is focused into present a review of chemical legislation policies in the European Union (EU) and in Russia, and changes in chemicals regulations to meet the requirement of REACH. Also, we reported the used of several approaches and chemo-bioinformatics tools applied to QSAR methodologies for the several parameters relative to toxicity and how they can be used for regulatory purposes in risk assessment.

Gil-Garcia R.,University of the East of Cuba | Pons-Porrata A.,University of the East of Cuba
Pattern Recognition Letters | Year: 2010

In this paper, two clustering algorithms called dynamic hierarchical compact and dynamic hierarchical star are presented. Both methods aim to construct a cluster hierarchy, dealing with dynamic data sets. The first creates disjoint hierarchies of clusters, while the second obtains overlapped hierarchies. The experimental results on several benchmark text collections show that these methods not only are suitable for producing hierarchical clustering solutions in dynamic environments effectively and efficiently, but also offer hierarchies easier to browse than traditional algorithms. Therefore, we advocate its use for tasks that require dynamic clustering, such as information organization, creation of document taxonomies and hierarchical topic detection. © 2009 Elsevier B.V. All rights reserved.

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