El supuesto de normalidad multivariante es exigido por muchos métodos estadísticos multivariantes; no obstante, muchos investigadores no comprueban este supuesto. Existen más de 50 pruebas de normalidad multivariante, pero se conoce poco sobre su desempeño. El objetivo de esta tesis es clasificar 15 pruebas de normalidad multivariante en diversos escenarios (combinación de tamaño de la muestra, número de variables y variabilidad generalizada). Se usaron simulaciones de Montecarlo para generar conjuntos de datos con distribuciones multivariantes, se incluyeron la distribución normal multivariante, la distribución multivariada de t y de Cauchy. Se calculó el estadístico de prueba para cada una de las 15 pruebas; el número de rechazos obtenidos se presentaron en cada situación. La contribución de cada prueba estuvo determinada por el error tipo I y la potencia de la prueba del...

The seroprevalence of bovine viral diarrhoea (DVB) in dairy herds and the presence of persistently infected animals in the four provinces of the Mantaro Valley, Peru were determined using the ELISA technique. A total of 425 blood samples were taken from animals of 37 herds and an epizootic survey was applied in parallel. The prevalence of DVB of the four provinces was 66.3% and the prevalence/herd of 64.8%. The province of Concepción showed the highest sample and herd prevalence (75.2 and 75.5%, respectively, and Huancayo had the lowest (48.3 and 52.3%, respectively). The prevalence of PI animals with DVB in the four provinces was 5.8%. Risk factors for the presentation of DVB were the intensive breeding system (OR: 6.545), open herd type (OR: 6.33), use of artificial insemination (OR: 7.895) and massive presence of rats (OR: 5.714). There was a positive association between high prevale...

Se determinó la seroprevalencia de la diarrea viral bovina (DVB) en hatos lecheros de las cuatro provincias que conforman el Valle del Mantaro, Región Junín, Perú, así como la presencia de animales persistentemente infectados, mediante la técnica de ELISA. Se tomaron 425 muestras de sangre de animales de 37 hatos y se aplicó paralelamente una encuesta epizootiológica. La prevalencia muestral de DVB para las cuatro provincias fue 66.3% y la prevalencia/hato de 64.8%. La provincia de Concepción registró la prevalencia muestral y por hato más altas (75.2 y 75.5%, respectivamente) y Huancayo presentó las más bajas (48.3 y 52.3%, respectivamente). La prevalencia de animales PI con DVB en las cuatro provincias fue de 5.8%. Los factores de riesgo para la presentación de DVB fueron el sistema intensivo de crianza (OR: 6.545), tipo de hato abierto (OR: 6.33), inseminación artificia...

Introduction: There is oversupply in pre-graduate formation of human resources for health care. The average number of newly formed physicians went from 27 in the 1917-1926 period to 1026 per year during 1990-1995, and a further increase has been reported, e.g., from 1287 in 1998 to 2183 in 2003. The Peruvian College of Physicians is concerned about a risk for reduced quality in the deliverance of health care services to the community and to the individuals because of an oversupply of health care professionals with heterogeneous schooling standards, and another contributing factor is an inadequate distribution and a quite variable professional competence of physicians in Peru.Objective: To identify the number and distribution of physicians in Peru, their working status, and the relationship between general practitioners and specialized physicians, describing all the aspects of s...

Introduction: There is oversupply in pre-graduate formation of human resources for health care. The average number of newly formed physicians went from 27 in the 1917-1926 period to 1026 per year during 1990-1995, and a further increase has been reported, e.g., from 1287 in 1998 to 2183 in 2003. The Peruvian College of Physicians is concerned about a risk for reduced quality in the deliverance of health care services to the community and to the individuals because of an oversupply of health care professionals with heterogeneous schooling standards, and another contributing factor is an inadequate distribution and a quite variable professional competence of physicians in Peru.Objective: To identify the number and distribution of physicians in Peru, their working status, and the relationship between general practitioners and specialized physicians, describing all the aspects of s...