622 research outputs found
Implications of water hardness in ecotoxicological assessments for water quality regulatory purposes: a case study with the aquatic snail Biomphalaria glabrata (Say, 1818)
Mulheres para a Marinha do Brasil: recrutamento e seleção das primeiras oficiais enfermeiras (1980-1981)
Doses of Crotalaria juncea: Residual effect on zucchini and maize crop in sequence to broccoli
Microfossils in micrites from Serra da Bodoquena (MS), Brazil: taxonomy and paleoenvironmental implications
Evapotranspiração e coeficientes de cultivo da beterraba orgĂąnica sob cobertura morta de leguminosa e gramĂnea.
As prĂĄticas agrĂcolas que maximizam a produtividade e o uso da ĂĄgua sĂŁo de vital importĂąncia para a agricultura. Assim, foram testados trĂȘs tipos de manejo do solo com objetivo de determinar a evapotranspiração (ETc) e os coeficientes de cultivo (kc) da beterraba. Os tipos de manejo foram a utilização de coberturas mortas vegetais, denominadas capim cameroon (Pennisetum purpureum), gliricĂdia (Gliricidia sepium) e solo sem cobertura morta em ĂĄrea experimental do SIPA (Sistema Integrado de Produção OrgĂąnica) localizado em SeropĂ©dica, Brasil. A lĂąmina de irrigação foi estimada com base no balanço de ĂĄgua no solo, cujo monitoramento foi realizado com a tĂ©cnica da TDR. As ETc acumuladas para a cultura da beterraba foram 59,41; 55,31 e 119,62 mm, respectivamente, para capim cameroon, gliricĂdia e solo sem cobertura morta. A evapotranspiração de referĂȘncia (ETo) foi obtida por meio do modelo de Penamn-Monteith. Os valores mĂ©dios de kc obtidos para as fases inicial, mĂ©dia e final de desenvolvimento foram de 0,39; 0,42 e 1,02; 0,79; 0,76 e 1,18; e 0,56; 0,61 e 0,84, respectivamente, para capim cameroon, gliricĂdia e solo sem cobertura morta. O uso da cobertura do solo com gramĂnea ou leguminosa minimizou de forma expressiva a demanda hĂdrica da cultura da beterraba (Beta vulgaris)
Benznidazole therapy for Chagas disease in asymptomatic Trypanosoma cruzi -seropositive former blood donors: evaluation of the efficacy of different treatment regimens
Are ant assemblages of Brazilian veredas characterised by location or habitat type?
Wetland areas in the Brazilian Cerrado, known as âveredasâ, represent ecosystems formed on sandy soils with high concentrations of peat, and are responsible for the recharge of aquiferous reservoirs. They are currently under threat by various human activities, most notably the clearing of vegetation for Eucalyptus plantations. Despite their ecological importance and high conservation value, little is known about the actual effects of human disturbance on the animal community. To assess how habitat within different veredas, and plantations surrounding them affect ant assemblages, we selected four independent vereda locations, two being impacted by Eucalyptus monoculture (one younger and one mature plantation) and two controls, where the wetland was surrounded by cerrado vegetation. Ant sampling was conducted in May 2010 (dry season) using three complementary methods, namely baits, pitfall traps, and hand collection, in the wetland and in the surrounding habitats. A total of 7,575 ants were sampled, belonging to seven subfamilies, 32 genera and 124 species.Ant species richness and abundance did not differ between vereda locations, but did between the habitats. When impacted by the monoculture, ant species richness and abundance decreased in wetlands, but were less affected in the cerrado habitat. Ant species composition differed between the three habitats and between vereda locations. Eucalyptus plantations had an ant species composition defined by high dominance of Pheidole sp. and Solenopsis invicta, while natural habitats were defined by Camponotus and Crematogaster species. Atta sexdens was strictly confined to native habitats of non-impacted âveredasâ. Eucalyptus monocultures require high quantities of water in the early stages, which may have caused a decrease in groundwater level in the wetland, allowing hypogeic ants such as Labidus praedator to colonise this habitat
Molluscicidal effect of Euphorbia umbellata (Pax) Bruyns latex on Biomphalaria glabrata, Schistosoma mansoni host snail
Testing arbitrary classes of light in a physiognomically heterogeneous area of "campo rupestre" vegetation
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