Chagas disease is the leading cause of nonischemic cardiomyopathy in Latin America. Timely access to diagnosis and trypanocidal treatment and preventive tools for millions of infected people continues to be a challenge. The purpose of this study was to identify potential barriers for the diagnosis of Chagas disease in Colombia from the perspective of healthcare providers. Using a simultaneous mixed-methods study design, we analyzed trends in access to screening and diagnosis for Chagas disease in Colombia and assessed the national barriers to access. The main barriers to access at the national level included a limited governmental public health infrastructure for the diagnosis of Chagas disease and limited physician awareness and knowledge of the disease. Data indicate that 1.5% of total expected cases based on national prevalence estimates were reported. Few public health laboratories have the capacity to perform complementary tests for the diagnosis of Chagas disease and almost 6 months elapse between the requests of the tests and the confirmation of the disease. This study shows that infected people must overcome a number of barriers to achieve diagnosis. Reducing barriers to early diagnosis of Chagas disease is an important goal in the fight against the disease.

A stochastic theory of fluvial landsurfaces is developed for transport-limited erosion, using well-established models for the water and sediment fluxes. The mathematical models and analysis is developed showing that some aspects of landsurface evolution can be described by Markovian stochastic processes. The landsurfaces are described by nondeterministic stochastic processes, characterized by a statistical quantity the variogram, that exhibits characteristic scalings. Thus the landsurfaces are shown to be SOC (Selforganized-critical) systems, possessing both an initial transient state and a stationary state, characterized by respectively temporal and spatial scalings. The mathematical theory of SOC systems is developed and used to identify three stochastic processes that shape the * and the University of Iceland, 107 Reykjavík 1 surface. The SOC theory of landsurfaces reproduces established numerical results and measurements from DEMs (digital elevation models).

El artículo tiene como propósito caracterizar las principales barreras que sufre la población colombiana al intentar acceder a los servicios de salud. Es un observacional descriptivo exploratorio que emplea técnicas tanto cuantitativas como cualitativas; se basó en los registros de Peticiones, Quejas, Reclamos y Sugerencias que llegaron a la Superintendencia Nacional de Salud de Colombia entre enero-2102 y Junio-2013; además, empleó entrevistas a profundidad a usuarios de los servicios de salud, a funcionarios de las Empresas Promotoras de Salud de Bogotá y de Puntos por el Derecho a la Salud de la Secretaría de Salud de Bogotá. Los usuarios de este estudio evidenciaron limitaciones desde la entrada y búsqueda de la atención por fallas en la comunicación para acceder a los Servicios de Salud; en la continuidad del servicio, se encuentran con barreras derivadas por las autorizaciones, falta de oportunidad para citas médicas especializadas, procedimientos quirúrgicos y entrega de medicamentos. Con base a los hallazgos se puede concluir que las barreras que perciben los usuarios generan percepciones negativas y efectos perjudiciales tanto para éstos, como para sus familias.

ABSTRACT. Despite their importance as freshwater reservoirs for downstream river systems, few glaciers in central Chile have been comprehensively surveyed. This study presents ground-penetrating radar (GPR) and field-based observations for characterizing the englacial and basal conditions of Glaciar Olivares Alfa (33°11 0 S, 70°13 0 W), central Chilean Andes. Using a 50 MHz radar mounted onto a helicopter platform, data were collected covering large portions of the glacier accumulation and ablation zones. The radar data revealed boundaries of a temperate-ice layer at the base of the eastern body of Glaciar Olivares Alfa which appears to be covered by colder ice that extends throughout large parts of the glacier. The thickness of the temperate ice layer is highly variable across the glacier, being on average 40% of the total ice thickness. Radar data analyses reveal regions of cold ice at the bottom/ base of the glacier and also patterns of highly saturated sediments beneath the glacier. Using GPR data, this study represents the most exhaustive analysis of glacier ice structure performed in the central Chilean Andes. The results will enable improved estimations of the glacier's mass balance and ice dynamics, helping us to understand its further development and its impact on water availability.

Resumen El objetivo de este estudio fue identificar la prevalencia y algunas características asociadas al uso de casco en dos ciudades en Colombia; se usaron tanto técnicas cuantitativas como cualitativas. La prevalencia de uso de casco en conductores de motocicleta fue mayor en Ibagué (98,1%) que en Valledupar (82,4%); en pasajeros de Valledupar no fue superior a 2%. Los hombres tuvieron 2.1 veces más posibilidad de usar el casco que las mujeres (IC 95: 1,6-2,7). Con las técnicas cualitativas se identificaron factores que explicaron los motivos de uso/no uso del casco (higiénicas, climáticas, estéticas y de seguridad) en Valledupar. El casco es una medida que protege ante un siniestro vial; no obstante, la prevalencia de uso no es la ideal. Es importante que las autoridades de tránsito, salud y la sociedad civil se organicen para diseñar y aplicar medidas orientadas para fortalecer el uso de este elemento de protección personal.