No abstract

This study aims to evaluate the effects of maghemite nanoparticles (γ-Fe2O3) coated with meso-2, 3-dimercaptosuccinic acid (DMSA) stabilizer on the survival and reproduction of the aquatic snail Biomphalaria glabrata. The cumulative means of egg masses and eggs per individual in the control group at the end of 4 weeks were 18.8 and 326.7, respectively. These values at the concentration of 1 mg/L were 17.2 and 291.6; at 10 mg/L, they were 19.6 and 334.4 ,and at 100 mg/L, they were 14.3 and 311.1. Results showed no significant differences between the tested and the control groups at the level of p < 0.05. Exposure of embryos for 10 days showed absence of mortality, malformation, or hatching delay. X-ray microtomography confirmed the presence of nanoparticles in exposed individuals and showed the complete elimination of the nanoparticles after 30 days in clean water. In the studied conditions, it is clear that γ-Fe2O3 coated with stabilizing DMSA did not alter the fecundity or the fertility of the snail B. glabrata after 4 weeks of exposure, and accumulation was not present after 30 days in clean water.

No abstract

Este artigo descreve uma proposta de desenvolvimento de sistema de irrigação do cultivo de palmeiras de açaí (Euterpe oleracea Mart.) por microaspersão voltado para pequenos e médios agricultores, especialmente da região do Baixo Tocantins. Os resultados desta pesquisa abrangem, neste primeiro momento, um levantamento e pré-projeto dos principais componentes e módulos do sistema proposto.