National Autonomous University of Nicaragua

About: National Autonomous University of Nicaragua is a education organization based out in Managua, Nicaragua. It is known for research contribution in the topics: Population & Public health. The organization has 775 authors who have published 715 publications receiving 9791 citations.

Interpretación de las relaciones intragrupales de riesgos y de lesiones mediante análisis cluster jerárquico

Abstract: A partir de los analisis cluster jerarquico de riesgos y de lesiones, se obtiene la secuencia del proceso de conglomeracion, basado en este caso en el metodo de Ward. El interes de dicho proceso de conglomeracion, para el caso de las variables riesgo y lesion,componentes del accidente laboral, se centra en que permite interpretar las relaciones entre dichas variables paso a paso, es decir, permite interpretar las afinidades existentes entre dichas variables a escala intragrupal. De esta manera se pueden explicar las relaciones que los diversos clusters van describiendo. Para el caso de los accidentes laborales, esta informacion interpretativa es de vital importancia al posibilitar asociar un significado a las relaciones entre variables obtenidas matematicamente, base conceptual de cualquier sistema inteligente.

Análisis proximal de granos de arroz, frijol, maíz y café comercializados en el mercado Roberto Huembes de Managua

Abstract: RESUMEN Se realizo el analisis proximal de los granos basicos: arroz, frijol, maiz, asi como del producto primario: cafe, comercializados en el mercado Roberto Huembes de Managua durante epoca de verano, a fin de obtener informacion sobre su composicion nutricional. Las pruebas realizadas fueron: porcentaje de humedad, cenizas, proteinas y grasas. Los resultados mostraron diferencias entre los valores obtenidos y los valores de referencias a nivel de Centro America. El frijol distribuido presenta un alto contenido de proteinas (23.87%), al igual que el maiz (8.80%) y el cafe (14.55%), sin embargo el porcentaje de grasa es variante para cada grano aunque en el maiz y el cafe los valores son inferiores a las referencias internacionales (6.58% y 10.03%, respectivamente). En el caso particular del arroz se determino que la variedad estudiada presenta una composicion inferior a los parametros establecidos

Investigation of seasonal river–aquifer interactions in a tropical coastal area controlled by tidal sand ridges

Abstract: Water exchanges between streams and aquifers influence the quantity and quality of water in both domains. Seasonal river–aquifer interactions were investigated in a tropical coastal area where tidal sand ridges control river discharge to the sea. The study site is located in southwestern Nicaragua, dominated by humid tropical hydro-climatic conditions. The aquifer provides water to the rural town of Ostional. Connectivity between the river and the aquifer influences water quality and water availability for humans and for the downstream estuarine ecosystem. The effect of stream stage fluctuations on river–aquifer flows and pressure propagation in the adjacent aquifer was investigated analyzing high temporal resolution hydraulic head data and applying a numerical model (HYDRUS 2-D). Tidal sand ridges at the river outlet control the flow direction between the river and the aquifer. Surface water accumulation caused by these features induces aquifer recharge from the river. Simulations show groundwater recharge up to 0.2 m 3 h −1 per unit length of river cross section. Rupture of the sand ridges due to overtopping river flows causes a sudden shift in the direction of flow between the river and the aquifer. Groundwater exfiltration reached 0.08 m 3 h −1 immediately after the rupture of the sand ridges. Simulated bank storage flows are between 0.004–0.06 m 3 h −1 . These estimates are also supported by the narrow hysteresis loops between hydraulic heads and river stage. The aquifer behaves as confined, rapidly transmitting pressure changes caused by the river stage fluctuations. However, the pressure wave is attenuated with increasing distance from the river. Therefore, we concluded that a dynamic pressure wave is the mechanism responsible for the observed aquifer responses. Pressure variation observations and numerical groundwater modeling are useful to examine river–aquifer interactions and should be coupled in the future with chemical data to improve process understanding.

Teorías motivacionales desde la perspectiva de comportamiento del consumidor

Abstract: Documento HTML en formato PDF, cuenta con 15 paginas en texto a blanco y negro. Tiene ademas diagramas y esquemas a color, datos a pie de pagina como complemento e indice bibliografico.

Assessing intraspecific trait variability during seedling establishment to improve restoration of tropical dry forests

Abstract: Forest restoration is an effective tool to mitigate climate change, but its implementation in highly diverse and threatened tropical dry forests (TDFs) is particularly challenging due to the hostile environment. Intraspecific trait variability (ITV) in response to these constraints may be very informative for predicting the potential for species acclimation and therefore for improving trait-based species screenings that best match each particular scenario of forest restoration. We analyzed ITV during seedling establishment of three widely distributed and ecologically contrasting TDF species in a greenhouse multifactorial experiment crossing levels of resource availability (nutrients and water) and herbivory to assess the capacity of ITV to discern strategies of seedling establishment and to predict species’ growth rates and acclimation potential. The three species studied had contrasting responses to the experimental treatments, suggesting different strategies of seedling establishment. The species with the most plastic pattern of growth performed the best, especially due to its ability to modulate the trade-off of root-to-shoot allocation of biomass depending on nutrient availability. Almost 50% of the variation in the root mass ratio was within species, half of which was a direct response of the treatments, indicating a strong acclimation potential. Individual-level trait measurements, however, were poor predictors of seedling growth rates. ITV, particularly the ability to adapt the pattern of biomass allocation, can be critical during seedling establishment. We propose incorporating information about ITV and the ability of species to modulate their phenotypic expression to cope with environmental variability into programs of forest restoration. Easily implemented and standardized greenhouse experiments are an inexpensive way to obtain high-quality data on the plasticity of forest species, which can be very valuable for predicting the potential of species acclimation and thus improving the selection of species that better match each particular scenario of restoration.