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1.
Environ Sci Pollut Res Int ; 30(27): 70937-70949, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37160855

RESUMO

This study focused on the determination of natural (238U, 232Th, and 40K) and artificial (137Cs) radionuclide concentrations both in 55 sediment samples collected from various depths in the Bosphorus and 5 soil samples from the coastline of the Bosphorus, Istanbul, using gamma-ray spectrometry with an HPGe detector. The mean activity concentrations of natural 238U, 232Th, and 40K and anthropogenic 137Cs were determined to be 11.41 ± 0.21 Bq kg-1, 6.87 ± 0.16 Bq kg-1, 369.61 ± 3.41 Bq kg-1, and 6.54 ± 0.11 Bq kg-1, respectively, in the sediment samples. The average activity concentrations of 238U, 232Th, 40K, and 137Cs radionuclides in the soil samples were also measured to be 11.65 ± 0.18 Bq kg-1, 9.55 ± 0.15 Bq kg-1, 369.43 ± 3.09 Bq kg-1, and 4.57 ± 0.09 Bq kg-1, respectively. Radiological contour maps based on the activity concentrations of natural and artificial radionuclides in the sediment samples for the Bosphorus, Istanbul, were created. The total annual effective doses due to soil samples were calculated to be 34.58 µSv y-1.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , Espectrometria gama/métodos , Solo
2.
Ecol Evol ; 3(16): 5237-53, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24455152

RESUMO

In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entocytheridae (Ostracoda) found in Europe as model organisms. We carried out an extensive survey to evaluate the distribution of entocytherids hosted by crayfish in Europe by checking 94 European localities and 12 crayfish species. Both exotic entocytherid species found, Ankylocythere sinuosa and Uncinocythere occidentalis, were widely distributed in W Europe living on the exotic crayfish species Procambarus clarkii and Pacifastacus leniusculus, respectively. No entocytherids were observed in the remaining crayfish species. The suitable area for A. sinuosa was mainly restricted by its own limitations to minimum temperatures in W and N Europe and precipitation seasonality in circum-Mediterranean areas. Uncinocythere occidentalis was mostly restricted by host availability in circum-Mediterranean regions due to limitations of P. leniusculus to higher precipitation seasonality and maximum temperatures. The combination of ENMs with set theory allows studying the invasive biology of symbionts and provides clues about biogeographic barriers due to abiotic or biotic factors limiting the expansion of the symbiont in different regions of the invasive range. The relative importance of abiotic and biotic factors on geographical space can then be assessed and applied in conservation plans. This approach can also be implemented in other systems where the target species is closely interacting with other taxa.

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