Spatio-temporal stochastic modelling of alluvium soils contaminated by heavy metals

A significant industrial development, associated with a demographic expansion, occurred during the last decades of the XX century, in Loures valley, a region located in the vicinities of Lisbon, the capital city of Portugal. This was accompanied with an important modification of land use and occupation patterns, mainly the decrease of the agricultural land (Silva et al, 2008). The input of heavy metals in soils of alluvium environment shows high variability in both space and time domains, hence the estimation of the measured elements (Co, Cr, Cu, Ni, V e Zn) should account for either dimension. Furthermore, it is also a non-stationary process, because spatial variability depends strongly on the distance to pollution sources and the amount of precipitation. The variability in time is dependent on the amount of rainfall recorded. Indeed it is a topographically flat area with altitude near zero causing thus a concentration of pollutants, not its leaching. Thus the soils pollution is more pronounced during the wet seasons than during the dry seasons. The methodology presented herein deals with the application of kriging with external drift as an interpolation procedure (Wackernagel, H., 1995) for the measured heavy metals elements, in a generalised space-time domain. The definition of an auxiliary variable is based on the description of the processes involved (R.Figueira et al, 2000). Kriging with such an external drift yields better estimates of metals concentration at ground level than ordinary kriging does, and such an enhanced performance can be checked out from the cross-validation results as well as from an observation of the corresponding, estimated maps

Use of water quality index to evaluate the influence of anthropogenic contamination on groundwater chemistry of a shallow aquifer, Loures valley, Lisbon, Portugal

A significant industrial development, associated with a demographic expansion, occurred during the last decades of the XX century, in Loures valley, a region located in the vicinities of Lisbon, the capital city of Portugal. This was accompanied with an important modification of land use and occupation patterns, mainly the decrease of the agricultural land. One of the main consequences was the deterioration of the groundwater chemistry observed in the shallow aquifer associated to Trancão river, a subsidiary of Tagus river. Factorial Correspondence Analysis has been used to build a water quality index, for evaluating the impact of the anthropogenic factors on groundwater of the shallow aquifer. By analysing the kriged maps of the values of the index, it was possible to identify the areas more sensitive to the anthropogenic impact

Spirulina does not decrease muscle damage nor oxdidative stress in cycling athletes with adequate nutritional status

The objective of this study was to assess the effect of Spirulina maxima on oxidative stress and muscle damage in cycling athletes subjected to high volume and intensity of training. Eighteen male athletes were randomly divided into an experimental group (n=11) with age 27.8±3.5 and placebo (n=7) with age 34.3±2.3 in a double-blind fashion. They carried out a protocol of Spirulina dietary supplementation (7.5 g/day) of placebo for four weeks and maintained their trainings during this period. A nutritional anamnesis was performed and blood tests were done to determine pre and post levels of creatine kinase (CK), lactic dehydrogenase (LHD), superoxide dismutase (SOD) and malondialdehyde (MDA). The supplemented and placebo groups performed the same volume training, has adequate macronutrients and antioxidant vitamins ingestion before study, as well as initial CK, LDH, SOD and MDA levels. Supplementation did not promote a significant alteration in CK levels on supplemented group (158.4±16.3 for 140.0±16.6 U/l, p>0.05), LDH (420±13.2 for 394.9±27.9 UI/l, p>0.05), MDA (2.8±0.2 for 2.9±0.4 nmol/ml, p>0.05), nor an increase in the SOD (7.3±0.6 for 7.0±0.6 U/mg Hb, p>0.05). We conclude that administration of Spirulina does not interfere in the magnitude of muscle damage nor in antioxidant status of cycling athletes that practice intense training