Lundberg Fleming (curlerwork5)

Secondly, the most tolerant lineages, though being more tolerant to a second exposure, exhibited the lowest survival recovery capacity after exposure to a first pulse of Cu. However, differences in the survival recovery capacity of the six clonal lineages after the exposure to the two pulses of Cu were not observed. Increasing the duration of the recovery period from 24h to 72h did not significantly alter mortality rates, except for the most sensitive and most tolerant clonal lineages. The results here obtained suggests that standard lethality assays may sub-estimate the toxicity of chemicals under realistic exposure scenarios, since sequential pulses are not infrequent in natural conditions.Superhydrophilic membranes with simultaneous underwater superoleophobicity are highly desirable and worth exploring for separation of emulsified oil from water. In this work, combining the strong negative charges of phytic acid (PA) and the high cationic charge density of polyethyleneimine (PEI), an eco-friendly PA@PEI polyelectrolyte complex was synthetized in aqueous solution. And then the polyelectrolyte complex was deposited onto hydrophobic PVDF membranes through a one-step assembly approach with high convenience, endowing the membranes with superhydrophilic and underwater superoleophobic property. The as-prepared PA@PEI/PVDF membrane shows outstanding static and dynamic water stability, and was successfully used to separate multiple oil-in-water emulsions, with an average rejection rate exceeding 98.5% and a water flux up to 12203.6 L m-2∙h-1∙bar-1. Furthermore, the water flux can be recovered to a high level after four separation-washing cycles, showing excellent antifouling performance and recovery capability. Together with its natural raw materials and environmentally friendly preparation strategy, the PA@PEI/PVDF membrane shows great potential in practical treatment of emulsified oily wastewater.Mass Nile crocodile (Crocodylus niloticus) deaths in Africa's premier conservation area, the Kruger National Park (KNP), prompted numerous studies to determine possible causes of the sudden die-offs. The majority highlighted the involvement of the anthropocene to crocodile mass mortalities. One of the potential causative agents was identified as legacy compounds such as organochlorine pesticides (OCPs) present in the various aquatic ecosystems of the KNP. Thus, this study aimed to quantify OCP levels in wild crocodiles from the aquatic systems associated with the KNP. As part of a larger study, muscle tissue samples were collected from tails of 12 wild crocodiles. check details Results indicated that eight of the 19 OCPs analysed for were quantifiable. These included DDTs (2130-167968 ng/g lw), chlordanes (BD - 7583 ng/g lw) and cyclodeines (BD - 872 ng/g lw). Measured concentrations indicated spatial- and sex-related differences in accumulation patterns. DDT and its metabolites, paricularly p,p'-DDE accumulated to the highest concentrations of the OCP groups. Levels of the different groups of OCPs were the highest recorded in recent history from any crocodilian tissue. The different measured OCP residues were between 2.5 and 120 times higher than levels reported in literature, depending on the compound. These results are of ecotoxicological significance and have several management implications. In view of individuals being sampled from a conservation area it emphasizes the fact that pollutants know no boundaries and that premier conservation areas such as the world renowned KNP may be some of the most contaminated areas of the world.As contamination of rice plants has aroused worldwide concern because of the threats posed to human health through its accumulation in the food chain. However, no data are currently available on the effect of Se nanoparticles (SeNPs) on the fate of As in higher plants, and previously reported relationships between As and Se are inconsistent. Therefore, in this study, the possible mediating roles of SeNPs