Encontrados 32 documentos, a visualizar página 1 de 4
Tolerance to Copper and to Salinity in Daphnia longispina: Implications within ...
Leitão, João; Ribeiro, R.; Soares, Amadeu M. V. M; Lopes, I.Considering IPPC climate change scenarios, it is pertinent to predict situations where coastal ecosystems already impacted with chemical contamination became exposed to an additional stressor under a future scenario of seawater intrusion. Accordingly, the present study aimed at evaluating if a negative association between tolerance to a metal and to saltwater exists among genotypes of a freshwater organism. For...
Contaminant driven genetic erosion and associated hypotheses on alleles loss, r...
Ribeiro, R.; Lopes, I.Microevolution due to pollution can occur mainly through genetic drift bottlenecks, especially of small sized populations facing intense lethal pulses of contaminants, through mutations, increasing allelic diversity, and through natural selection, with the disappearance of the most sensitive genotypes. This loss of genotypes can lead to serious effects if coupled to specific hypothetical scenarios. These may be...
Effects of cyclic fluctuations in meridional circulation using a low-order dyna...
Lopes, I; Passos, DWe develop and subsequently explore the solution space of a simple flux transport dynamo model that incorporates a time-dependent large-scale meridional circulation. Based on recent observations, we prescribed an analytical form for the amplitude of this circulation and study its impact in the evolution of the magnetic field. We find that cyclic variations in the amplitude and frequency of the meridional flow a...
Impact of a Realistic Density Stratification on a Simple Solar Dynamo Calculation
Lopes, I; Cardoso, EIn our Sun, the magnetic cycle is driven by the dynamo action occurring inside the convection zone, beneath the surface. Rotation couples with plasma turbulent motions to produce organized magnetic fields that erupt at the surface and undergo relatively regular cycles of polarity reversal. Among others, the axisymmetric dynamo models have been proved to be a quite useful tool to understand the dynamical process...
Developing a site-conditions map for seismic hazard Assessment in Portugal
Narciso, J.; Vilanova, S.; Lopes, I.; Oliveira, C. S.; Carvalho, J.; Pinto, C.; Borges, J. F.; Nemser, EThe evaluation of site effects on a broad scale is a critical issue for seismic hazard and risk assessment, land use planning and emergency planning. As characterization of site conditions based on the shear-wave velocity has become increasingly important, several methods have been proposed in the literature to estimate its average over the first thirty meters (Vs30) from more extensively available data. These ...
Eficiência de fungicidas para controle da ferrugem asiática da soja, Phakopsora...
GODOY, C. V.; SILVA, L. H. C. P. da; UTIAMADA, C. M.; SIQUERI, F. V.; LOPES, I. de O. N.; ROESE, A. D.; MACHADO, A. Q.; FORCELINI, C. A.; PIMENTA, C. B.2009
Solar Variability Induced in a Dynamo Code by Realistic Meridional Circulation ...
Lopes, I; Passos, DIn this work we use an already-published method to infer a variation profile for the solar meridional circulation over the last 250 years. We feed this variation profile into a numerical dynamo code, and we reconstruct a sunspot time series that acts as a proxy for solar cycle activity. We perform three simulations with slightly different parameters, and the results are compared with the observational data. The...
Development and Sensitivity of a 12-h Laboratory Test with Daphnia magna Strau...
Rosa, R.; Moreira-Santos, M.; Lopes, I.; Picado, A.; Mendonça, E.; Ribeiro, R.Abstract Studies on avoidance of contaminants by aquatic organisms verified that such behavior may have crucial ecological implications. Yet, avoidance tests have not been considered in ecological risk assessments. This study aimed at developing a short-term test with Daphnia magna Straus based on avoidance of pulp mill effluents and at comparing its sensitivity to the standard 21 d D. magna reproduction test....
A Low-Order Solar Dynamo Model: Inferred Meridional Circulation Variations Sinc...
Passos, D; Lopes, iIn this work we present the possible variations that the meridional circulation of the Sun might have undergone during the last 250 years. In order to do this, we reduce an α-Ω dynamo to a low-order system that focuses on the time evolution of one of the solar magnetic field components. Afterward we used a method based on the analysis of phase space of the superficial toroidal magnetic field to infer changes in...
Instalação da lavoura de soja: época, cultivares, espaçamento e população de pl...
GARCIA, A.; PÍPOLO, A. E.; LOPES, I. de O. N.; PORTUGAL, F. A. F.2007
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||