78 resultados para Orthogonal polynomials on the real line


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Wastewater-based epidemiology (WBE) applies advanced analytical methods to quantify drug residues in wastewater with the aim to estimate illicit drug use at the population level. Transformation processes during transport in sewers (chemical and biological reactors) and storage of wastewater samples before analysis are expected to change concentrations of different drugs to varying degrees. Ignoring transformation for drugs with low to medium stability will lead to an unknown degree of systematic under- or overestimation of drug use, which should be avoided. This review aims to summarize the current knowledge related to the stability of commonly investigated drugs and, furthermore, suggest a more effective approach to future experiments. From over 100 WBE studies, around 50 mentioned the importance of stability and 24 included tests in wastewater. Most focused on in-sample stability (i.e., sample preparation, preservation and storage) and some extrapolated to in-sewer stability (i.e., during transport in real sewers). While consistent results were reported for rather stable compounds (e.g., MDMA and methamphetamine), a varying range of stability under different or similar conditions was observed for other compounds (e.g., cocaine, amphetamine and morphine). Wastewater composition can vary considerably over time, and different conditions prevail in different sewer systems. In summary, this indicates that more systematic studies are needed to: i) cover the range of possible conditions in sewers and ii) compare results more objectively. To facilitate the latter, we propose a set of parameters that should be reported for in-sewer stability experiments. Finally, a best practice of sample collection, preservation, and preparation before analysis is suggested in order to minimize transformation during these steps.

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In Atlanta, the trade ministers of a dozen countries across the Pacific Rim announced that they had successfully reached a concluded agreement upon the Trans-Pacific Partnership. The debate over the TPP will now play out in legislatures across the Pacific Rim, where sentiment towards the deal is much more mixed. The ministers insisted: “After more than five years of intensive negotiations, we have come to an agreement that will support jobs, drive sustainable growth, foster inclusive development, and promote innovation across the Asia-Pacific regionThe agreement achieves the goal we set forth of an ambitious, comprehensive, high standard and balanced agreement that will benefit our nation’s citizens … We expect this historic agreement to promote economic growth, support higher-paying jobs; enhance innovation, productivity and competitiveness; raise living standards; reduce poverty in our countries; and to promote transparency, good governance, and strong labor and environmental protections.” But there has been fierce criticism of the Trans-Pacific Partnership, because of both its secrecy and its substance. Nobel Laureate Professor Joseph Stiglitz has warned that the agreement is not about free trade, but about the protection of corporate monopolies. The intellectual property chapter provides for longer and stronger protection of intellectual property rights. The investment chapter provides foreign investors with the power to challenge governments under an investor-state dispute settlement (ISDS) regime. The environment chapter is weak and toothless, and seems to be little more than an exercise in greenwashing. The health annex — and many other parts of the agreement — strengthen the power of pharmaceutical companies and biotechnology developers. The text on state-owned enterprises raises concerns about public ownership of postal services, broadcasters and national broadband services.

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In the context of increasing threats to the sensitive marine ecosystem by toxic metals, this study investigated the metal build-up on impervious surfaces specific to commercial seaports. The knowledge generated in this study will contribute to managing toxic metal pollution of the marine ecosystem. The study found that inter-modal operations and main access roadway had the highest loads followed by container storage and vehicle marshalling sites, while the quay line and short term storage areas had the lowest. Additionally, it was found that Cr, Al, Pb, Cu and Zn were predominantly attached to solids, while significant amount of Cu, Pb and Zn were found as nutrient complexes. As such, treatment options based on solids retention can be effective for some metal species, while ineffective for other species. Furthermore, Cu and Zn are more likely to become bioavailable in seawater due to their strong association with nutrients. Mathematical models to replicate the metal build-up process were also developed using experimental design approach and partial least square regression. The models for Cr and Pb were found to be reliable, while those for Al, Zn and Cu were relatively less reliable, but could be employed for preliminary investigations.