Mccollumkamp9192

Both species of pinnipeds have been differentially exposed to trace elements depending on their feeding area. A pelagic diet, possibly based on squid, increased the concentration of Cd in A. australis, while O. byronia has been more exposed to anthropogenic Pb and Cu associated to a costal and more benthic diet. Our results highlight dentin as a reliable matrix for historic studies on the exposure to trace elements. In light of our results, the O. byronia's declining population could be the result of the synergistic effects of trace elements together with other ecological pressures faced in their environment.Compared to homogeneous soils, soil heterogeneity is thought to promote plant species diversity through niche differentiation. The number of patch types within the heterogeneous soil (i.e. the difference in soil configurational heterogeneity) may also play a key role in regulating plant diversity. However, most empirical studies examining heterogeneity-diversity relationships involved only two contrasting types of patches. Moreover, the shape of heterogeneity-diversity relationships may also be changed by background soil fertility. To test how soil heterogeneity and number of patch types within the heterogeneous soil influence plant community evenness and their potential dependence on background soil fertility, we constructed plant communities consisting of four plant species in low- and high-nutrient soils, and manipulated the soils in heterogeneous configurations consisting of two or four types of soil patches and in a homogeneous condition where these soil patches were homogenized. Neither evenness of the plant community nor the difference in competitive ability between plants within the community was significantly different between the homogeneous soil and the heterogeneous soils, suggesting that soil heterogeneity overall had no effect on community evenness. However, evenness was higher and the difference in competitive ability between plants was lower in the heterogeneous soils with four types of soil patches than in the heterogeneous soils with two types of soil patches and also in the low-nutrient soils than in the high-nutrient soils. These results suggest that lowering soil fertility and increasing soil configurational heterogeneity can promote plant community evenness through reducing the difference in competitive ability between plant species within the community.To meet the continuous growth of urbanised areas with the ever-increasing demand for safe water supplies, the implementation of new scientifically based methodologies can represent a key support for preventing groundwater quality deterioration. In this study, a new combined approach based on the application of the Weights of Evidence and the Null-Space Monte Carlo particle back-tracking methods was set up to assess tetrachloroethylene (PCE) contamination due to Point Sources in the densely urbanised north-eastern sector of the Milano FUA (Functional Urban Area). This combined approach offers the advantage of further enhancing the power of each individual technique by integrating both the advective transport mechanism, neglected by the Weights of Evidence, and the influence of specific factors, such as the land use variation, not considered by the Null-Space Monte Carlo particle tracking. To accurately test and explore the performance of this new approach, the analysis was carried out based on the simulation of synthetic PCE plumes using a groundwater numerical model already implemented in a previous study. The Weights of Evidence method revealed that the areas characterised by a groundwater depth lower than 17 m, a groundwater velocity higher than 2.6 × 10-6 m/s, a recharge higher than 0.26 m/y and a significant variation of the industrial activities extent are the most susceptible to groundwater pollution. The Null-Space Monte Carlo particle back-tracking has proved to be effective in delineating the potential source zones and contaminant travel path. The proposed approach can offer additional insights for the protection of groundwater resource. The end-product provides crucial information on the zones that require to be prioritised for investigations and can be easily understood by non-expert decision-makers constituting an advanced tool for enhancing groundwater protection strategies.The quantification and comparison of NOX emission from in-situ car fleets, and identification of the highest emitters is an ongoing challenge. This challenge will become more important as new and increasingly complex emissions removal systems penetrate the market. We combine real-world data with new-to-the-field statistical methods to describe fleet-scale emissions behaviours and identify candidate gross-emitter vehicles. 19,605 passenger cars were observed using a Remote Sensing Device across Aberdeen in 2015. Of these, 736 were Euro 6 Passenger Cars. The distribution of observed pollutant per unit of fuel burnt ratios for most fuel type and Euro standards followed an asymmetrical shape best characterised by the Gumbel distribution. The Gumbel distribution approach was not able to fully replicate the distribution of measurements of petrol or Euro 6 diesel cars due to the presence of a subset of high-emitting outliers, ranging from the 13th percentile for Euro 3 petrol to the 2nd percentile for Euro 6 petrol, with Euro 6 diesel having a 5th percentile outlier value. No outlier fraction was observed for pre-Euro 6 diesels. The off-model fractions resembled Gumbel distributed data and in some cases could be modelled as a separate distribution with the fleet behaving as a superposition of them. It is shown that VSP was not directly linked to this behaviour and it is hypothesised that it is caused by the emissions control systems operating sub-optimally. The reasons for sub-optimal operation are beyond the scope of this paper but may be linked to air-fuel mixture sensors, cold-start running and deterioration of the catalytic converter. Tofacitinib manufacturer Larger data-sets with more Euro 6 passenger cars are required to fully test this. Application of this methodology to larger data sets from more widely deployed remote sensing devices will allow observers to identify potentially problematic vehicles for further investigation into their emission control systems.