Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

In this paper we present an estimate of the posterior error of finite element-constructed finite element meshes and finite element discontinuous over time for the transport equation of CO2 in the bags Alveolar cells of the human lung, using the dual weighted residual method (DWR).

In this work, we present the dynamics of biological control through a mathematical model using a simple food chain of three trophic levels. This mathematical model is based on a ratio-dependent predator-prey model with Holling type II functional response, adding a top predator so this model is a system of three ordinary differential equations. We study the existence and uniqueness, invariance and boundary of solutions. The information given in this work could also be useful for the design of development plans that meet the needs of the agricultural sector to guide the non-pollution of the environment in the country through the use of biological control to control pests.

In this work, we present explicit parameterizations of hypersurfaces parameterized by lines of curvature with prescribed Gauss map and we characterize the hypersurfaces with planar curvature lines. As an applicationwe obtain a classification of isothermic surfaces with respect to the third fundamental form with two planar curvature lines. Also, we present a class of surfaces with one family of planar curvature lines and generalize these results to present classes of hypersurfaces with families of planar curvature lines.

This article consider the classical problem of linear non-homogeneous second order Initial Value Problems with analytic coefficients. It classifies the possible kinds of analytic solutions, giving criteria for the nonexistenceof analytical solutions and for the existence of multiple analytic solutions. An alternative proof for the convergence of the power series method is given and it applies for some singular irregular points.

This research was carried out with the objective of characterizing the growth of rainbow trout (Oncorhynchus mykiss) in Lake Titicaca using nonlinear models, from which points of biological and economic interest were identified, as well as predictions of food requirements to improve the productive and economic performance. The information used corresponds to the company Perú Pacífico located in the district of Capachica, province of Puno. The models analyzed were Logistic, Gompertz and Richards that were estimated using SAS ® NLIN and the Marquardt algorithm. The Richards model showed a higher coefficient of determination (R2). That is, it adequately describes and predicts trout growth in Lake Titicaca, under specific management conditions. The Logistic and Gompertz models showed lower predictive capacity when overestimating and underestimating the weight in the initial phase of growth, while in the final phase, they underestimate and overestimate, respectively. The growth profile shows slow weight increases in the adaptation phase to the environment, accelerated to the point of inflection, tends toward an asymptotic value as it approaches adulthood, and has a sigmoid shape, typical in trout. Finally, it has been determined the period of adaptation to the environment, the point of inflection, the time in which they would reach commercial weight (200, 250, 330 and 500 gr), and the requirement of food at certain times of a productive cycle of 269 days.

The purpose of this study was to determine the factors that have an effect on the deterioration of the quality of the credits portfolio and to estimate the incidence of the quality of the credit portfolio in the financial solvency of the savings and credit cooperatives of the Puno region, period 2012 - 2014; the problem that credit and savings cooperatives are facing is the high delinquency of more than 10%, which affects the quality of the credit portfolio and puts financial solvency in risk. For the achievement of the proposed objectives, the non-experimental research design, descriptive and explanatory type, was applied; inductive and deductive method, non-probabilistic sampling was used selecting six cooperatives from a population of ten. The result for the first objective is obtained from the processing of the survey by which it is confirmed, in the deterioration of the quality of the credits portfolio, internal factors and external factors affect, the internal factor of greater relevance is the poor credit evaluation carried out by the analysts and for the second specific objective the result is obtained from the regression of the econometric model, where the evidence is shown that the delinquency rate has a negative impact on the financial solvency of the savings and credit cooperatives of the Puno region, in the period 2012 - 2014.

The aim of this study is to estimate the potential economic benefits of an integral improvement in the provision of basic sanitation services (water, sewage and treatment) through the choice experiment (EE) with multinomial logit models and mixed logit. 392 surveys were conducted on users of basic sanitation services in the city of Puno. Using the mixed logit model-dummy codes, an aggregate marginal willingness to pay (MWTP) of S/9.95/month/household was estimated. Based on the logit multinomial model-effect codes, it was possible to estimate the compensatory variation (CV) in S/9.11/month/household. When comparing both results, it is concluded that there are no significant differences, therefore, any of these monetary welfare measures, when aggregated in terms of the population potentially benefiting from the change, could be used as a measure of economic benefit if a Cost-Benefit Analysis were done. It has also been shown that the attribute "treatment" is more valued than the attributes "water" and "sewerage", therefore, any policy aimed at improving basic sanitation services in the city of Puno should be primarily focused on solving the wastewater treatment. The choice of alternatives for improvement in basic sanitation services is conditioned by the educational level and the monthly monetary income of the users.

The objective of the investigation of hospital effectiveness measurement in the Puno region, using Data Envelopment Analysis (DEA), all the time determines the change in total factor productivity during the period 2011-2013. The results show that the efficiency of hospitals in the Puno region of category II-1 was 0.96; While all hospitals (categories II-1 and category II-2) were 0.88 in the period 2011-2013. Regarding productivity, the results suggest that changes in productivity at a hospital level occur mainly because of changes in technical efficiency rather than a change in technological progress. Finally, through the Mann - Whitney test, it was found that there is insufficient evidence to argue that the size or complexities of the hospitals are variables that determine the difference in the level of efficiency obtained

The main objective of this research was to analyze the impact of public investment on the economic growth of the regions of Peru, during the period 2001-2013. Public investment is approached through the execution of public expenditure on Public Investment Projects, which were disaggregated into four sectors: social, productive, infrastructure and others. As a source of information, the database of the National Institute of Statistics and Information and the Portal of Economic Transparency of the Ministry of Economy and Finance were used. For data analysis, an econometric methodological dynamic panel data approach proposed by Arellano and Bond (1991) was used. The results achieved suggest that public investment social has a positive and statistically significant impact on economic growth; In addition, the evidence indicates the sectors infrastructure and productive have generated a positive impact on growth, but were not statistically significant at a level of significance of 5%; investment in other sectors presented a negative impact on economic growth because it is statistically significant. The conclusions point to demonstrate that good programming and execution of spending on Public Investment Projects can help increase economic growth.

The objective of this study is to estimate the impact of the JUNTOS program on the income of the beneficiary household by analyzing its effect on the different quantiles of the income distribution of the beneficiary households, and on their labor income. For this, the panel database of the National Household Survey (ENAHO) is used between 2013 and 2015, applying techniques for studies with quasi-experimental design such as Propensity Score Matching (PSM), the estimate with double differences (DD) and the quantile regression (QR). From the estimates made, it is concluded that the JUNTOS program had a positive impact on the total income of the beneficiary household, increasing its income by 20% more than a non-beneficiary household; In addition, the impact is differentiated for households located in the lowest quantile, who increased their income by 31% more than a non-beneficiary household located in the same quantile, with respect to labor income a negative impact is shown, but not significant.