Volumen 5 No. 2 (2014)
Permanent URI for this collectionhttps://dspace-test.ucuenca.edu.ec/handle/123456789/20966
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Item Simplificación del proceso complejo de reducción de escala de los modelos climáticos globales por medio de la aplicación web SDW(Universidad de Cuenca, 2014-12) Gualán, Ronald; Sánchez, Esteban; Campozano, Lenin; Samaniego, Esteban; Vázquez, Angel; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca; DIUCThe generation of climate change scenarios is based on the results of global climate models (GCM), which because of their low resolution require the use of downscaling techniques to assess the impact at local scale. Of the downscaling techniques, based either on the use of regional climate models or statistical methods defining the statistical relationship between synoptic climate variables and observations, previous studies revealed that statistical approaches most accurately predict future climate variables in mountainous areas, such as the Andes mountain range. To standardize and facilitate the assessment of the uncertainty between GCM models of future climate, greenhouse gas scenarios, and downscaling techniques, a versatile tool would be most appropriate and helpful. This paper presents the development, implementation and use of a web application that integrates all the steps in downscaling, it is from the search, analysis and storage of data, the selection, calibration and validation of models, up to downscaled outputs. The presented tool could easily be linked to a decision support system for climate change adaptation.Item El desarrollo del sistema energético solar-hidrógeno en América Latina: potencialidades, oportunidades y barreras(Universidad de Cuenca, 2014-12) Posso Rivera, Fausto René; Sánchez Quezada, Johanna Patricia; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca; DIUCSolar-Hydrogen Energy Systems (SHES) are systems whose primary energy source is solar energy, directly or indirectly, and the secondary is hydrogen. Those systems are currently considered as the best option to complement and replace mid-term the energy systems based on fossil fuels. The main objective of the work presented herein is the identification and analysis of the factors involved in the development of SHES in Latin America. The study is a documentary research based on an extensive review of literature. Latin American countries possess an enormous potential of exploitable renewable energy; among them hydropower and biomass are often seen as the most suitable contributors to the energy mix, however SHES might evolve with time to an economic attractive alternative. Studies indicate that rural electrification and urban transport are niche opportunities that will enhance the development of SHES. The barriers hindering in Latin America the development and application of hydrogen energy are discussed: among them Latin American countries invest little in hydrogen energy research, and the few research is concentrated in a limited number of countries; the availability of poor trained and skilled human talent to further develop, adopt and operate this technology, with the consequence of an overall weak formative offer; a non competitive cost structure with respect to the fossil fuel based energy systems; and the lack of an institutional framework that encourages the development of this system. It is concluded that only the concerted action of research centers, universities and the private sector, guided by the government, will make it possible that this unique chemical element via sustainable applications shall contribute to the human development in Latin America.Item Uso de suero de leche líquido en la alimentación de cuyes (Cavia porcellus) en la etapa de crecimiento y engorde(Universidad de Cuenca, 2014-12) Rosales Jaramillo, Cornelio Alejandro; León Calle, Natalia Fabiola; Fajardo Fajardo, María Fernanda; Jara García, Xavier Geovanny; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca; DIUCA ration of 25%, 50%, 75% and 100% liquid whey in the feeding of male and female guinea pigs was tested versus a control of 0% liquid whey in the daily diet during the period of growth and fattening. The population consisted of 150 animals, distributed in a random block design with three replications. The daily diet consisted of different levels of liquid whey on top of a weekly budgeted food package of commercial concentrate and alfalfa. Results revealed a positive correlation between the dosage of liquid whey in the diet and the weight of male and female guinea pigs, with the most positive and significant effect (p < 0,5) in treatment 100% for males and 75% for females. The benefit/cost ratio was highest in the treatments 75 and 100%; 1,37 versus 1,10 in the control. Degustation, based on the variables color, smell and tenderness, scored best for a liquid whey supplement of 50%; flavor scored highest for a 100% supplement of liquid whey; and the presentation and acceptance variables scored best at a 75 and 100% supplement.Item Remoción de la hemoglobina por adsorción sobre nanopartículas magnéticas de Fe3O4/TiO2(2014) Vanegas Peña, María Eulalia; García Alvear, Nancy Beatriz; Vazquez Freire, Veronica Eulalia; Moscoso, DinaThe removal of Hemoglobin (Hb) by protein adsorption on magnetic nanoparticles (Nps) of Fe3O4/TiO2 (core/shell), applying an external magnetic field, was investigated using ultraviolet spectroscopy in the ultraviolet and visible range (UV-VIS). The Nps concentration and temperature was varied during the contact step between Nps and Hb. Complementary, the intensity of the external magnetic field was varied during the removal of the Fe3O4/TiO2-Hb complex. With an initial Nps concentration of 8 mg ml-1, the absorbance of the supernatant solution showed a decrease of 11% with respect to the initial Hb solution (0,8 g l-1), and a decrease of 17% when the Nps concentration was increased with 50%. A reduction of the absorbtion of Hb was observed by increasing the temperature from 25 to 35ºC, but no evidence of denaturalization was found. During the Fe3O4/TiO2-Hb complex removal step, the absorption intensity nearly decreased 30% by increasing the strength of the magnetic field. Finally, the biochemical oxygen demand (BOD5) of the initial Hb solution and supernatant was determinated. The value of the initial Hb solution was 100 mg ml-1 and the results for all treated solutions were lower (< 62 mg ml-1) reflecting the impact of magnetic Nps in the removal of HbItem Inducción de la brotación in vitro de microplántulas de nogal (Juglans neotropica) tratadas con Thidiazuron (TDZ) y 6-Bencilaminnopurina (BAP)(Universidad de Cuenca, 2014-12) Peña Tapia, Denisse Fabiola; Rocano Curillo, Melida Noemi; Salazar, Jazmin M.; Torres, Carlos S.; Universidad de Cuenca; Dirección de Investigación de la Universidad de CuencaThe walnut (Juglans neotropica) is a species of great potential for conservation projects and eco-agro-production in the Andean region. However, low germination capacity limits its spread for reforestation. The aim of this study was to determine the effect of treatment with Thidiazuron (TDZ) and 6-Benzylaminopurine (BAP) on in vitro shoot induction of J. neotropica. The micro plantlets treated with BAP produced more shoots than those treated with TDZ. The micro plantlets treated with BAP and TDZ in turn generated more shoots than the non-treated micro plantlets. In the test, the effect of concentration of BAP and TDZ in the medium was also evaluated; however not statistically significant differences between the tested concentrations were detected. In summary, findings indicate that the treatment with cytokines, BAP specifically, increases the number of shoots produced by micro plantlets J. neotropica. It is believed that this treatment can be applied on projects of mass propagation of this species within the frame of reforestation programs.Item Diagnóstico de la relación entre el uso excesivo de las TICs y síntomas depresivos y ansiedad en estudiantes de medicina, Universidad de Cuenca, Ecuador(Universidad de Cuenca, 2014-12) Ortiz Segarra, José Ignacio; Morocho Malla, Manuel Ismael; Tenezaca Tacuri, Ángel Hipólito; Torres Ordóñez, María Gabriela; Ugalde T., Diana P.A descriptive cross-sectional study among students of the Faculty of Medicine of the University of Cuenca was conducted to assess the magnitude of the excessive use of Information and Communication Technology (ICT), the variation in terms of age, sex, marital status and career, and its association with depressive and anxiety symptoms. The validated questionnaire submitted to a random cluster of 333 students, included in addition to the gathering of demographic information, questions probing the use of ICT and depressive and anxiety symptoms. The concept of Relative Risk associated with a Confidence Interval of 95% was used in the statistical analysis. Results revealed that the average age of the sample population was 22 years, 37,2% use ICT excessive, and 18,3% show depressive symptoms and 39,8% signs of anxiety. Variables significantly associated with the excessive use of ICT are students younger than 19 years (RR 2,04; CI 95% 1,31-3,20), male gender (RR 1,36; CI 95% 1,03-1,80) and the Medical Technology field of study (RR 1,83; CI 95% 1,28-2,63). Excessive use of ICT is not associated with the marital status. However, the statistical analysis revealed the existence of a significant positive correlation between problematic ICT use and the frequency of students with depressive symptoms (RR 1,88; CI 95% 1,45-2,44) and anxiety (RR 2,61; CI 95% 1,64-4,15).Item Estimulación de los centros cerebrales del habla y el lenguaje en adquisición de lectoescritura en niños de 4 a 6 año(Universidad de Cuenca, 2014-12) Montalvo Bernal, José Heriberto; Universidad de Cuenca, DIUC; Dirección de Investigación de la Universidad de CuencaThe objective of the study was to validate a model of stimulation procedures of the brain centers of speech and language, aiming the acceleration of read-write teaching in 4 to 6 years old children in two schools of Cuenca city. It was a prospective analytical study, with quasi-experimental design. The cluster type sample included 39 children in the intervention group and 60 in the control group. The experimental intervention lasted five months comprising educational activities, the rehabilitation of individual functions, and clinical group consulting and individual control. The composition of the sample groups was based on the average psycholinguistics age (PLA) of the children. The association between variables was measured using ANOVA to compare group behavior before and after; the t-Test for comparing means between groups. Previously, the homogeneity of the sample groups was determined using the Levene test. Kendal’s tau-b and tau-c were used to measure the association between the ordinal variables. A 95% confidence level was applied for the estimation of the confidence interval of the variables. The study showed an increase in the PLA average, from 4,78 to 6,11, similar to its parameters (p < 0,05), except for visual understanding (p > 0,05). However, the increase was greater in the intervention group, which benefited from the implementation of the brain center stimulation procedures (p < 0,05). The study clearly revealed that these procedures reduce the risk of reading difficulties in children (p < 0,05).Item Influence of international institutions on the development of Ecuador’s education system during neoliberalism(Universidad de Cuenca, 2014-12) Oviedo O., Alexis; Universidad de Cuenca, DIUC; Dirección de Investigación de la Universidad de CuencaThe article analyses the Ecuadorian system of basic education during the years of neoliberalism, and relates curricular discourses of this period with global trends determined by international institutions, particularly the World Bank. Through a rigorous analysis of institutional documents, documentary sources and semi-structured interviews with Ecuadorian educational system actors, the research evaluates to what extent public policies developed in the nineties, were determined by the agenda of international cooperation.