824 resultados para dredge-and-fill activity
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Ecological processes in tropical forests are being affected at unprecedented rates by human activities. Yet, the continuity of ecological functions like seed dispersal is crucial for forest regeneration. It thus becomes increasingly urgent to be able to rapidly assess the health status of these processes in order to take appropriate management measures. We tested a method to rapidly evaluate seed removal rates on two animal-dispersed tree species, Virola kwatae and V.michelii (Myristicaceae), at three sites in French Guiana with increasing levels of anthropogenic disturbance. We counted fallen fruits, fruit valves, and seeds of each focal fruiting tree in a single 1m2 quadrat, and calculated two indices: the proportion of seeds removed and the proportion of fruits opened by mammals. They both provide an indirect and rapid assessment of frugivore activity. Our results showed a significant decrease in the proportion of removed seeds (16%) and fruits opened (19%) at the most impacted site in comparison with the other two sites (79% for seeds, 60% and 35% for fruits). This testifies to an increased impoverishment of the primate and toucan communities at the disturbed sites. This standardized protocol provides fast information about the health status of the community of seed dispersers and predators and of their seed removal services. It is time- and cost-effective and is not species-specific, allowing comparisons among sites or over time. We suggest using it with the pantropical Myristicaceae and any other capsule-producing family to rapidly assess the health status of seed removal processes across the tropics.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This study was addressed to investigate the composition and antifungal activity of essential oils from leaves of Piperaceae species (Piper aduncum, Piper amalago, Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper gaudichaudianum, Piper solmsianum, Piper regnellii, Piper tuberculatum, Piper umbelata and Peperomia obtusifolia) against Candida albicans, C. parapsilosis, C. krusei and Cryptococcus neoformans. The essential oils from P. aduncum, P. gaudichaudianum and P. solmsianum showed the highest antifungal activity against Cryptococcus neoformans with the MIC of 62.5, 62.5 and 3.9 mg.mL-1, respectively. The oil from P. gaudichaudianum showed activity against C. krusei with MIC of 31.25 mg.mL-1.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study aimed to investigate the antitumor and cytotoxicity activities of Kielmeyera coriacea and Pyrostegia venusta extracts. Therefore, the hydroalcoholic extracts of P. venusta flowers and K. coriacea leaves were prepared. The extracts were evaporated and the dry extracts were diluted at concentrations of 1.0, 0.1, 0.01 and 0.001 mg/ml for carrying out the bioassays. Artemia salina eggs were incubated in saline solution at 28°C for 24 h. The larvae were treated with different extracts concentrations and the mortality was evaluated after 24 and 48 h. Five discs of potato were placed in Petri dishes and 50 μl of inoculum of Agrobacterium tumefaciens were added to it at 28°C for 24 h incubation. So, 50 μl of the extracts in different concentrations were added. Positive and negative controls were made. The P. venusta and K. coriacea extracts did not show statistically significant acute toxicity. K. coriacea extract showed (mean% of tumor ± standard deviation) 15.30 ± 3.24, 6.34 ± 3.82, 7.57 ± 2.92 and 5.77 ± 2.85 and P. venusta showed 25.82 ± 5.15, 38.40 ± 8.28, 15.75 ± 4.44 and 13.38 ± 7.92, with their concentrations for the antitumor bioassay, and the positive control showed 25.80 ± 6.14. According to the obtained results it was established that the K. coriacea and P. venusta extracts showed antitumor activity but did not show significant cytotoxic activity in A. salina test.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)