Navegando por Autor "MARCELIANO, Maria Luiza Videira"

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Acesso aberto (Open Access)
A first evaluation on the use of Ardea albus feathers as bioindicators of mercury burden in Amazonian ecosystems
(Instituto Nacional de Pesquisas da Amazônia, 2009) GOMES, Andreza de Lourdes Souza; VIEIRA, José Luiz Fernandes; PINHEIRO, Maria da Conceição Nascimento; MARCELIANO, Maria Luiza Videira
We evaluated in this study the total mercury concentration in feathers of Ardea albus collected in a colony located in the city of Belem-PA, Brazil in a prospective trial for its use as bioindicators of mercury burden in Amazonia ecosystems. An Atomic absorption spectrophotometry with gold amalgamation was used for the metal determination. The total mercury average concentration in body feathers was 2.2 ± 1.5 µg.g-1 and 1.3 ± 0.9 µg.g-1 in wing feathers. No correlation was observed between total mercury concentration and the length of body or wing feathers. Total mercury concentration was above 5 µg.g-1 dry weight in only one body feather sample.
Acesso aberto (Open Access)
Natural gaps associated with oxidative stress in Willisornis poecilinotus (Aves: Thamnophilidae) in a tropical forest
(Instituto Nacional de Pesquisas da Amazônia, 2014-06) GOMES, Andreza de Lourdes Souza; GONÇALVES, Andrey Felipe Gomes; VIEIRA, José Luiz Fernandes; MARCELIANO, Maria Luiza Videira; SILVA, José Maria Cardoso da
Natural disturbances in tropical forests modify the availability and quality of resources and alter the patterns of bird distribution. These environmental changes increase the metabolic rate and disrupt the redox balance promoting oxidative stress. This study aimed to compare the abundance of Willisornis poecilinotus between gaps and the understory of a forest with undisturbed canopy at Caxiuanã National Forest. The abundance was correlated with vegetation heights. The oxidative stress and the stress promoting factors were determined in both sites of sampling. We captured 81 specimens of W. poecilinotus. The number of captures was high in gaps. The specimens sampled at gaps showed high levels of oxidative stress. The biomarkers of oxidative stress were significantly correlated in gaps. The variability of oxidative stress and oxidative damage were explained only by site of sampling. These results suggest that gaps are stressors sites to W. poecilinotus, which probably can be due to an increase of metabolic rate to deal with new flight strategies of foraging and avoid predation.