8,995 research outputs found
Resposta do arroz à adubação nitrogenada em latossolo amarelo sob pastagem degradada de Paragominas - Pará.
Resposta de milho e soja à adubação fosfatada em latossolo amarelo muito argiloso de Paragominas - Pará.
FERTBIO 2006
Seletividade de herbicidas para a cultura do tomate para processamento industrial híbrido BRS Sena.
Objetivou-se com este trabalho avaliar a seletividade de herbicidas para a cultura do tomate para processamentoindustrial híbrido BRS Sena.Trabalho 1
Testing nitrogen fertilizer sources to increase N-Use efficiency of common beans in the Brazilian savanna.
Rural-urban migration in d-dimensional lattices
The rural-urban migration phenomenon is analyzed by using an agent-based
computational model. Agents are placed on lattices which dimensions varying
from d=2 up to d=7. The localization of the agents in the lattice define their
social neighborhood (rural or urban) not being related to their spatial
distribution. The effect of the dimension of lattice is studied by analyzing
the variation of the main parameters that characterizes the migratory process.
The dynamics displays strong effects even for around one million of sites, in
higher dimensions (d=6, 7).Comment: 9 pages, 7 figures, to be published in International Journal of
Modern Physics C 1
Salinity dependence of the distribution of multicellular magnetotactic prokaryotes in a hypersaline lagoon
Candidatus Magnetoglobus multicellularis is an unusual magnetotactic multicellular microorganism composed of a highly organized assemblage of gram-negative bacterial cells. In this work, the salinity dependence of Ca. M. multicellularis and its abundance in the hypersaline Araruama Lagoon, Brazil were studied. Viability experiments showed that Ca. M. multicellularis died in salinities >55‰ and < 40‰. Low salinities were also observed to modify the cellular assemblage. In microcosms prepared with different salinities, the microorganism grew better at intermediate salinities whereas in high or low salinities, the size of the population did not increase over time. The concentrations of Ca. M. multicellularis in the lagoon were related to salinity; sites with lower and higher salinities than the lagoon average contained less Ca. M. multicellularis. These results demonstrate the influence of salinity on the survival and distribution of Ca. M. multicellularis in the environment. In sediments, the abundance of Ca. M. multicellularis ranged from 0 to 103 microorganisms/ml, which represented 0.001% of the counts of total bacteria. The ability of Ca. M. multicellularis to accumulate iron and sulfur in high numbers of magnetosomes (up to 905 per microorganism) suggests that its impact on the sequestration of these elements (0.1% for biogenic bacterial iron) is not proportional to its abundance in the lagoon. [Int Microbiol 2009; 12(3):193-201
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