The role of the family, media advertising and school influence on the eating habits of children was reviewed. The exposure of children to these behavioral factors has modified the consumption patterns in children, resulting in an increase in the prevalence of obesity. This underlines the importance of health education as a preventive and promotional tool in the change of behaviors related to the adoption of healthy eating habits, emphasizing the development of nutritional programs applied in schools with the cooperation of parents and teachers to modify unhealthy behaviors and to acquire healthy life styles.

Se realizó una revisión teórica acerca del papel de la familia, los anuncios publicitarios y la escuela, en la adopción, o bien modificación de los hábitos alimentarios de los niños. Debido a que las nuevas dinámicas familiares y la gran exposición de los niños a los comerciales alimentarios han modificado los patrones de consumo de los niños originando con ello el aumento de la obesidad infantil, motivo por el que se enfatiza la importancia de la educación para la salud como herramienta preventiva y promocional en el cambio de conductas relacionadas con la adopción de hábitos alimentarios saludables, destacando el desarrollo de programas nutricionales aplicados en escuelas con el objetivo de buscar el trabajo conjunto entre los padres de familia y los profesores, para lograr modificar conductas no saludables y lograr estilos de vida saludables.

The evolution of the nutrition concept is described until arriving to the concept of three-dimensionality, analyzing it from at the world level, in Latin America and México. Nutrition used to be considered an exclusively biological process; nevertheless, now it involves social and ecological aspects. The convergence between the health concept and nutrition from the biosocial conception of the individual is analyzed, emphasizing the importance of education as a promotional tool, which includes not only includes the informative aspect but also the modification of behavior to change the individual's lifestyle.

Se describe la evolución del concepto de nutrición hasta llegar a la concepción de la tridimensionalidad del mismo. Analizándolo desde el nivel mundial, América Latina y México. Se consideraba a la nutrición como un proceso exclusivamente biológico, sin embargo actualmente involucra aspectos sociales y ecológicos. Se destaca la convergencia entre el concepto de salud y nutrición, a partir de la concepción biopsicosocial del individuo, motivo por el que se enfatiza la importancia de la educación para la salud como herramienta preventiva y promocional que no solo incluye el aspecto informativo sino también la modificación de conductas con el objetivo de que el individuo adquiera estilos de vida saludables. Se concluye con la manera como la educación para la salud se articula con las tres dimensiones de la nutrición.

An Integral equation formulation for steady flow of a viscous fluid is presented based on the boundary element method. The continuity, Navier-Stokes and energy equations are used for calculation of the flow field. The governing differential equations, in terms of primitive variables, are derived using velocity-pressure-temperature. The calculation of fundamental solutions and solutions tensor is showed. Applications to simple flow cases, such as the driven cavity, step, deep cavity and channel of multiple obstacles are presented. Convergence difficulties are indicated, which have limited the applications to flows of low Reynolds numbers.

This work presents a computational model for the viscous flow through rectilinear cascades of axial turbomachinery. The model is based on modifications of the classical Hess & Smith panel method. The viscous effect of the attached flow portion is introduced by means of normal transpiration velocities obtained from the boundary layer calculations on the airfoil contour. At the separated flow portion, fictitious velocities semi-empirical normal velocities are introduced assuming a constant pressure in the wake. When the separation is not detected, it is possible to simulate the effect of the small wake near the trailing edge by using an injected flow on a distance based on the Gostelow (1974) fairing-in procedure. The numerical model presents two iteration cycles: the first one to find the separation point, and the second one to accomplish the viscous-inviscid interaction, in which the transpiration velocities and the flow injection are submitted to a relaxation process in order to guarantee the convergence of the method. Results for the pressure distributions, flow turning angles and lift coefficients are compared with experimental data for the model validation.

El cultivo del guayabo tiene un gran potencial en el estado Zulia; sin embargo, el manejo que se le da al cultivo parece ser una de las principales causas de los bajos rendimientos. En este estudio se evaluó una forma integrada de prácticas agronómicas y culturales con la finalidad de controlar los principales patógenos causantes de la pudrición apical del fruto y secamiento del árbol, comparándose con el sistema tradicionalmente utilizado por el productor. El manejo integrado involucró el control químico de patógenos junto a prácticas culturales complementarias. El ensayo se realizó en 52 árboles de 8 años de edad, sembrados a una distancia de 8 x 8 m, los cuales presentaban alta incidencia de nemátodos y pudrición apical El manejo integral se aplicó a 26 árboles, dejando los otros 26 como testigos (manejo tradicional). Se evaluaron las variables de incidencia de pudrición apical (PA), índice de agallamiento (IA) de las raíces, población del nemátodos (j2/cm³ de suelo) y rendimiento (número y peso de frutos) por planta. Se aplicó la prueba de t para la comparación de medias. Los resultados mostraron que en los árboles que recibieron el manejo integrado se redujo la frecuencia de Botryodiplodia y Dothiorella, así como la población de juveniles de nemátodos (j2/cm³ de suelo); no así la frecuencia de aparición de los mismos. En cuanto a los rendimientos, con el manejo integral se logró obtener los mayores valores para los dos años evaluados. Es recomendable la aplicación de un sistema integrado de prácticas para el control de patógenos, orientando el uso de productos químicos en aquellos casos donde la ocurrencia de patógenos es alta.

The guava is an important crop in Zulia State, Venezuela: However, its low yields may be attributed to management reasons. In this paper, an integrated management was evaluated to control nematodes and pathogens causing stylar end rot as compared to the traditional farm management. The integrated management involved chemical control of pathogens along with complementary cultural practices. The experiment was conducted in 52 eight-year old trees planted at 8 x 8 m. Such trees showed high nematode and high stylar end rot incidence. Integrated management was applied to 26 trees, leaving 26 with traditional management (control). Stylar-end rot incidence, galls nematode index, nematode population (j2/cm³ of soil) and yield (number and weight of fruits) were evaluated and statistical t test was applied. Results showed that integrated management decreased Botryodiplodia and Dothiorella frequency, as well as young nematode population (j2/cm³ soil). However nematode frequency remained. Higher yields were obtained under integrated management in the two evaluation years. It is advisable to apply an integrated management system for pathogen control, and chemical control where pathogen incidence is high.

O feijoeiro (Phaseolus vulgaris L. cv. Carioca) foi cultivado em solução nutritiva na presença das seguintes concentrações de N, P e K, respectivamente em milimoles por litro: 16-2-6; 4-2-6; 1,6-2-6; 16-0,5-6; 16-0-6; 16-2-3; 16-2-0,6. Os outros macronutrientes e os micronutrientes foram fornecidos em doses iguais a todas as plantas. O estado nutricional foi avaliado através das seguintes técnicas: diagnose foliar (determinação dos teores totais de N, P e K e da concentração de nitrato e fosfato solúvel), atividade da redutase do nitrato (RNO3). Todos os métodos utilizados refletiram bem o estado nutricional do feijoeiro, exceto para P, .sendo que para a atividade da RNO3, os teores totais de N e K e de N-nitrato foram os que apresentaram a melhor correlação positiva com a produção das vagens.

Bean plants (Phaseolus vulgaris L., cv. Carioca) were grown in nutrient solution in the presence of the following concentrations of N, P and K, respectively, in milimoles per liter: 16-2-6; 4-2-6; 1,6-2-6; 16-0,5-6; 16-0-6; 16-2-3 and 16-2-0,6. The remaining macro and all micronutrients were supplied at the same rates to all plants. The nutritional status was assessed by the following techniques: foliar diagnosis (determination of total N, P and K and of the nitrate-N and soluble phosphate concentration) and nitrate reductase activity (RNO3). All methods proved to be suitable, except in the case of P. Higher correlations with bean production, however, were obtaind for total concentration of N and K, nitrate-N, and RNO3 activity.