Resumen El auge de la televisión por cable, el advenimiento de Internet y la expansión de las redes sociales han contribuido a que se difundan profusamente mensajes que están afectando en gran manera el sistema agroalimentario al difundir imprecisiones y generar, en algunas esferas, pánico hacia el consumo de productos de origen animal. El imaginario colectivo ha estado cargado de creencias que, en la mayoría de los casos, no tienen suficientes fundamentos y, en muchos otros, tienen un sentido político o intenciones sin sustento técnico ni científico. El objetivo de este documento es presentar elementos de juicio para examinar algunos mitos relacionados con los sistemas de producción bovina con el fin de aportar al debate sobre el consumo de este tipo de carne, que ha tomado fuerza alrededor del mundo.

Abstract The rise of cable television, the Internet, and the importance of social networks have contributed to the widespread dissemination of messages that are seriously affecting the agri-food system, mainly due to the dissemination of inaccuracies that create panic in some regions about the consumption of animal origin products. The collective imaginary is loaded with beliefs that, in most cases, do not have enough foundations and, in many others, it has a political sense or intentions without technical and scientific support. The aim of this document is to present evidence to support some myths related to bovine production systems to favor the debate on the consumption of beef, which is gaining strength around the world.

ABSTRACT The objective of this research was to evaluate the effect of three different intensive silvopastoral systems (ISPS) on cattle animal welfare (AW) in Colombia. The three ISPS differed in area, plant composition, and grazing periods as follows: ISPS1 - low plant diversity in paddocks of 1200 m2, with grazing period of 24 h; ISPS2 - middle plant diversity in paddocks of 600 m2, with grazing period of 12 h; and ISPS3 - high plant diversity in paddocks of 600 m2, with grazing period of 24 h. Animal welfare was assessed using a wide range of criteria, which were integrated using L-spline functions and Choquet integrals to generate overall values. It was found that AW was good in all ISPS; the highest scoring criteria was for food and water, with 99, 97, and 100 points from a maximum of 100 for ISPSs 1, 2, and 3, respectively. Comfort showed values of 100 for all three systems, but good health was the most problematic criteria of the AW features with scores of 25, 40, and 36 for ISPSs 1, 2, and 3, respectively. All three ISPS showed excellent scores for appropriate behavior (82, 88, and 89). The welfare problems shown here were not specific to the individual ISPS, but were common to all livestock systems in the region. Despite the differences in diversity of plants, size of paddocks, and grazing period among the three ISPSs tested, all of them provide cattle with sufficient resources and a diverse environment, ensuring a good state of welfare to them.

ABSTRACT Interesting properties of metal foams such as light weight, good energy absorption and low thermal conductivity, have promoted the development of new processes to improve properties without sacrificing productivity. This study aims to verify the uniformity pore distribution in an aluminum alloy foam obtained by Casting - Dissolution Process, using a nondestructive analysis. In order to evaluate mechanical properties of a metal foam using computational numerical models, the use of a small reconstructed section of the sample representing an entire volume of metal foam, was validated. In conclusion, it was possible to determine that all parts of the sample have the equivalent superficial area and volume.

Resumen Los sistemas silvopastoriles intensivos (SSPi) se han presentado en los últimos años como una modalidad de agroforestería pecuaria que pretende intensificar naturalmente la ganadería y convertirla en una actividad responsable ambiental y socialmente. Sin embargo, aún son muchas las incógnitas de carácter técnico y científico que deben resolverse para tratar de entender cómo funcionan estos sistemas. Una de ellas tiene que ver con la eficiencia en el uso de la energía. El objetivo del presente estudio fue realizar una aproximación a la partición de la energía de bovinos en pastoreo en SSPi y sus implicaciones en el desempeño productivo, haciendo una comparación con sistemas ganaderos convencionales. Se caracterizó el tiempo invertido por los animales en las principales actividades de comportamiento y se comparó con reportes en sistemas convencionales. Adicionalmente, se proyectó la ganancia de peso para diferentes rangos de peso vivo, encontrando mejoras económicas y productivas durante el pastoreo en SSPi. Según las observaciones y cálculos realizados se sugiere que los bovinos que pastorean en SSPi utilizan mejor la energía al gastar menos en desplazarse, pudiendo invertir más en ganancia de peso.

Abstract Intensive silvopastoral systems (ISS) have been presented in recent years as a form of agroforestry that aims to intensify livestock farming in a natural way and make it an environmentally and socially responsible activity. However, there are still many unsolved technical and scientific issues to understand how these systems work. One of those questions has to do with the efficient use of energy. The aim of this study was to make an approach to energy partition in cattle grazing under ISS and its implications on productive performance, comparing with conventional farming systems. Time spent by the animals in their main behavioral activities was characterized and compared with reports on conventional systems. Additionally, weight gain was projected for different body weight ranges, finding economic and productive improvements for ISS grazing. According to the observations and calculations of this study, it is suggested that cattle grazing under ISS use energy better because they spend less on walking and more energy can be saved for weight gain.

Resumo Os sistemas silvopastoris intensivos (SSPi) tem se apresentado nos últimos anos como uma modalidade de agroforesteria pecuária que pretende intensificar naturalmente a produção de gado e transformá-lo em uma atividade responsável ambiental e socialmente. Embora, ainda são muitas as incógnitas de caráter técnico e cientifico que devem ser resolvidas, e assim, deste jeito tentar entender adequadamente como funcionam esses sistemas. Uma delas, ainda não resolvida, tem que ver com o uso e a eficiência no uso da energia. O objetivo do presente estudo foi realizar uma aproximação à partição da energia em bovinos que pastejam em SSPi e avaliar suas implicações no desempenho produtivo, fazendo uma comparação com sistemas de produção de gado convencional. Desenvolveu-se um trabalho para caracterizar o tempo investido pelos animais nas principais atividades comportamentais em SSPi e comparou-se com reportes em sistemas convencionais. Adicionalmente, realizou-se uma projeção do ganho de peso de bovinos com diferentes amplitudes entre os pesos, evidenciando melhoras econômicas e produtivas quando os animais se encontram pastejando SSPi. Segundo as observações e cálculos realizados, é possível sugerir que os bovinos que pastejam SSPi utilizam melhor a energia ao gastar menos em se deslocar e ao contrario, investir mais no ganho de peso.

Se presenta un algoritmo en Matlab 2010a basado en un modelo matemático para predecir los momentos y las fuerzas de reacción en un punto particular del socket vinculado al miembro inferior de un amputado transfemoral. El modelo tiene en cuenta las inercias desarrolladas durante el ciclo de la marcha. Se realiza una validación del modelo comparando los resultados con los datos obtenidos en un laboratorio de análisis de la marcha y se encuentra una buena correspondencia con los datos experimentales en las fases de apoyo y balanceo.

Based on a mathematical model of the human gait, a Matlab 2010a algorithm is presented to predict the reaction forces and moments in a particular point along the socket linked to the lower limb of a transfemoral amputee. The model takes the inertia developed due the swing of the limb during the gait into consideration. A validation of the results is made with the data obtained in a gait lab, and the model results are consistent with those obtained in the gait lab.

INTRODUCCIÓN: a pesar de que la implementación de la ley 100 de 1993 ha desencadenado profundos cambios en la prestación de servicios de atención médica y en las condiciones laborales del personal asistencial, hay pocos estudios en nuestro medio que exploren este último impacto. El presente trabajo tiene como propósito describir la situación actual de los pediatras generales y subespecialistas en Antioquia en el período 2004-2005, con énfasis en los factores sociales, laborales y económicos. MATERIALES Y MÉTODOS: del cruce de las bases de datos de la Sociedad de Pediatría de Antioquia y de algunas casas farmacéuticas se obtuvo un universo de 321 pediatras de los cuales se encuestaron en forma aleatoria 220. RESULTADOS Y CONCLUSIONES: el perfil resultante muestra un hombre (53,2%) o una mujer (46,8%) de 44,6 años, egresado predominantemente de la universidad pública local (70,2%) que trabaja en el área metropolitana (94%), en una institución de carácter privado (56,8%) y en un segundo o tercer nivel de atención. Labora 8,62 horas al día, 5,51 días a la semana y realiza turnos nocturnos en el 55,8% de los casos. El 43% devenga mensualmente menos de 4.000.000,oo pesos por su actividad como pediatra y se siente satisfecho con su profesión pero no con el pago que recibe ni con la carga horaria. Su familia le reclama mayor presencia en el hogar, es sedentario y accede en forma irregular a la educación médica continuada. Este estudio constituye un acercamiento a las condiciones específicas de la pediatría en Antioquia y convendría reproducirlo en otras especialidades y regiones del país.

BACKGROUND : Even though the implementation of the Law 100 of 1993 has given rise to profound changes in the medical attention services and working conditions of health service personnel, there are few studies that explore the impact on the latter. The purpose of the present study was to describe the current situation of pediatricians and pediatric Antioquia during the 2004-2005 period , with emphasis on social, workrelated and economic factors. MATERIALS AND METHODS: Crossing the data bases of the Pediatrics Society of Antioquia and some pharmaceutical companies, a universe of 321 pediatricians was obtained, from which 220 were randomly interviewed. RESULTS AND CONCLUSIONS: The resulting profile yielded a man (53.2%) or a woman (46.8%) aged 44.6 years, who graduated from the public local university (70.2%), works in the metropolitan area (94%), in a private institution (56.8%) on a second or third level health service. He/she has a work load of 8 ,62 hours a day, 5.51 days a week and works night shifts in 58.8% of cases. 43% earn less than 4.000.000,oo pesos (Colombian pesos) for their activity as pediatricians and they feel satisfied with their professional activity, but not with the salary received or the hourly work load intensity. Families demand that more time is spent at home. These pediatricians are sedentary and regularly take part in continued medical education activities. This study constitutes an approach to the specific conditions of pediatrics in Antioquia and should be reproduced in other specialties and places throughout the country.