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Mem. Inst. Oswaldo Cruz ; 92(3): 323-8, May-Jun. 1997. mapas, tab, graf
Artigo em Inglês | LILACS | ID: lil-189301


This study was carried out in five sites along a small perennial river system in south-central Tanzania, which had been identified as the focus for transmission of intestinal schistosomiasis in the area. Malacological surveys preceding the study showed a focal distribution of Biomphalaria pfeifferi, intermediate host snail of Schistosoma mansoni, the snail being present in three sites but absent from the other two sites. The objective of this study was to evaluate to what extent chemical and/or physical-morphological factors determine the distribution of B. pfeifferi between these five sites. It was found that none of the chemical constituents in the waters examined were outside the tolerance range of B. pfeifferi snails. Moreover, the composition of water from B. pfeifferi-free sites was not different from that in those sites where snails occurred. Furthermore, none of the physical-morphological constituents seemed likely to be determinant for the absence of B. pfeifferi. In view of these findings, and those of previous studies, it is concluded that the focal distribuition of B. pfeifferi cannot be associated with a single environmental factor and is rather the result of more complex interactions of habitat factors.

Animais , Biomphalaria/química , Esquistossomose/epidemiologia , Tanzânia , Química da Água
Ciênc. cult. (Säo Paulo) ; 49(1/2): 25-33, jan.-abr. 1997. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-198295


The relatively large number of scientific publications on natural and constructed wetlands around the world is due to the importance these areas have as critical sites where biogeochemical cycling of elements is extensive on a global scale. The understanding of ecological functions and community structure is highly dependent on the knowledge of those cycles and their interactions. These studies are also relevant because natural or constructed wetlands are sites used worldwide to treat industrial and domestic effluents. This paper reports on a series of studies performed and in progress at the Jataí Ecological Station (Moji-Guaçu river, Luiz Antonio, SP, Brazil) with emphasis on the main biogeochemical properties of aquatic systems found there (lacustrine and riverine). Results obtained during the last 10 years within the scope of the Jataí Project with its various subprojects is just beginning to permit understanding the high complexity of these ecosystems.

Bioquímica , Ecossistema , Química da Água , Sistemas Ecológicos Fechados
Lima; CEPIS; 1987. 332 p.
Monografia em Espanhol | LILACS | ID: lil-146621


Enfoca generalidades del control de la calidad del agua y muestra criterios, guías y normas sobre agua potable. Analiza detalladamente las características físicas y químicas del agua, y los parámetros físico-químicos en su tratamiento. Trata de las pruebas de control en plantas de tratamiento. Presenta parámetros de calidad, métodos analíticos y equipos necesarios, criterios para selección de métodos, programa de control de calidad para un laboratorio de análisis de aguas, aspectos prácticos de la observación de parámetros. Señala los manuales de métodos para análisis químicos

Laboratórios , Microbiologia da Água , Características da Água , Química da Água , Qualidade da Água