Presencia y distribución espacial de Simulium sp. (Díptera: Simuliidae) en dos provincias de Angola / Presence and spatial distribution of Simuliumsp.(Diptera: Simuliidae) in two provinces of Angola

En el oeste de África los miembros del complejo Simulium damnosum son los vectores de la oncocercosis. El objetivo es obtener datos sobre la presencia y distribución de simúlidos en dos provincias de Angola. El trabajo se realizó en las provincias de Huambo y Bié donde se muestrearon 24 cuerpos de agua entre julio y agosto, 2015. Todos los sitios se localizaron por encima de una altitud de 1 000 m y solo tres resultaron negativos a la presencia de simúlidos. Estos resultados constituyen los primeros que se obtienen sobre la presencia y distribución espacial de Simulium sp. en Angola de gran importancia, pues la superposición de los mapas de distribución de la infección humana y los vectores permiten localizar áreas con peligro de transmisión(AU)

In West Africa Simuliumdamnosum complex members are the main vectors of onchocerciasis. The objective of this paper was to collect data on the presence and spatial distribution of black flies in two provinces of Angola. The research work was conducted in Huambo and Bié provinces where 24 water bodies were sampled between July and August 2015. All the studied sites were located above 1 000 m of altitude and only three of them were found to be negative for the presence of black flies. These were the first results obtained on the presence and spatial distribution of Simulium sp. in Angola and are of great importance because overlapping the distribution maps of human infection and of vectors allows finding the areas at risk of transmission(AU)

Displaced amacrine cells in the ganglion cell layer of the ground squirrel retina

In some mammals a large portion of the retinal neurons of the ganglion cell layer are not ganglion cells. These neurons, lacking axons which pass to the brain via the optic nerve, are termed displaced amacrine cells. The present study assessed the number of displaced amacrine cells in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). We compared the number of labeled cells in the ganglion cell layer after HRP injection of optic tracts and target nuclei with the total number of neurons in the ganglion cell layer. We conclude that approximately one half of the neurons in the ganglion cell layer are displaced amacrine cells, the other one half are ganglion cells. The displaced amacrine cells are on the average smaller than the ganglion cells. Our results provide a rationale for renewed study of relation of ganglion cell morphology and physiological functional type in this species