Statistical Analysis of Tropospheric Ozone Concentration

This paper analyzes ozone monitoring data obtained from 50 European stations operated by the Co-operative Programme for Monitoring and Evaluation of the Long Range Transmission of Air Pollutants in Europe (EMEP) and two stations maintained by the Austrian Environmental Agency. Data used in the analyses covered the summer period of the year 1990. The analysis explores first time series of ozone concentration and establishes simple statistical parameters such as maximum, average, daily variation and exceedance indices. It is shown that different indices rank high at different locations in Europe, stressing the importance of well-based information when establishing relationships to environmental impacts. Different characteristic exposure patterns are identified for Northern Europe, Central Europe and the UK. The analysis shows that at some stations also night time ozone concentration has a remarkable effect on cumulated excess ozone. Thus, caution should be exerted when excluding the nighttime values until more detailed data on the biological effects of nighttime high concentrations are obtained

Cost-Effective Sulphur Reduction Under Uncertainty

The problem of reducing SO2 emissions in Europe is considered. The costs of reduction are assumed to be uncertain and are modeled by a set of possible scenarios. A mean-variance model of the problem is formulated and a specialized computational procedure is developed. The approach is applied to the transboundary air pollution model with real-world data

Direct Effects of Sulfur on Forests in Europe - A Regional Model of Risk

A simple dynamic model for the sensitivity and risk in forests under long-term exposure to airborne sulfur is presented. The model is an interpretation of results from long-term forest damage and sulfur dioxide measurements in Czechoslovakia, and it focuses on damage caused by direct, foliar impacts. The input to the model is the annual average SO2 concentration, and the accumulation of impact over time is incorporated. In a regional application of the model, sensitivity is defined as a function of the effective temperature sum. Sensitivity and risk maps of Europe in relation to direct impacts of sulfur are presented

The reduction in air quality impacts and associated economic benefits of mitigation policy: Summary of results from the EC RTD ClimateCost Project

The objective of the ClimateCost project is to advance knowledge on the economics of climate change, focusing on three key areas: the economic costs of climate change (the costs of inaction), the costs and benefits of adaptation, and the costs and benefits of long-term targets and mitigation. The project has assessed the impacts and economic costs of climate change in Europe and globally. This included a bottom-up sectoral impact assessment and analysis of adaptation for Europe, as well as a global economic modelling analysis with sector-based impact models, computable general equilibrium models and global economic integrated assessment models. This technical policy briefing note (TPBN) provides an overview of the air quality benefits work undertaken in the project, which has assessed the avoided impacts and economic ancillary benefits of mitigation policy, focusing on Europe (EU27), though with discussion of the benefits for China and India

A Framework to Estimate the Potential and Costs for the Control of Fine Particulate Emissions in Europe

This paper presents a methodology for estimating primary PM emissions in Europe and the costs involved to reduce these emissions from the various sources in the European countries. The framework developed is compatible with existing approaches to estimate emissions and costs for SO2, NOx, NH3 and VOC in the RAINS model. Emissions of PM are released from a large variety of sources with significant technical and economic differences. The emission characteristic of the sources is also strongly influenced by country-specific conditions. The method applied considers the crucial parameters and allows sectoral and regional variation. The emissions of particulate matter (PM) in the RAINS model are calculated for three different size classes (i) fine fraction (PM2.5), (ii) coarse fraction (PM10 - PM2.5) and (iii) large particles (PM_>10 mu m). A methodology has been developed to estimate emission control costs of standard technologies under the specific conditions characteristic for the various European countries. Based on the assumption of the general availability of control technologies with equal technical properties and costs, a number of country-specific circumstances (level of technological advancement, installation size distribution, labor costs, etc.) are used to estimate the costs for the actual operation of pollution control equipment. Based on the developed methodology, a first estimate of the PM emissions in Europe was derived for the years 1990, 1995 and 2010. This estimate must be considered as preliminary, since many of the emission factors need revision and update with additional information. The projections for the year 2010 assume full implementation of the current legislation on emission controls, e.g., the EURO-IV emission standards resulting from the Auto Oil process for mobile sources, and regulations relating to the large combustion plant directive of the European Union. Major reductions in PM emissions occurred between 1990 and 1995, mainly because of the economic restructuring in Eastern Europe where many old coal power stations were retired. Between 1990 and 1995, TSP emissions declined by 41 percent; for 2010 a decline of 58 percent is projected. Emission reductions are most efficient for larger particles; for 2010, PM10 is calculated to decline by 56 percent, and PM2.5 by 48 percent. Consequently, fine fraction (PM2.5) will be relatively more important in the future (38 percent of TSP in 2010) compared to 31 percent of TSP in 1990. In 1990, combustion in energy industries, small non-industrial combustion sources, production processes and road transport contributed about 20 percent each to total TSP emissions in the EU-15. In the non-EU countries, small sources and power plants were responsible for more than 30 percent each, while road transport contributed only three percent of TSP. In those countries, small sources (domestic coal and wood combustion) are expected to increase their share to 45 percent in 2010, while in the EU-15 mobile sources will become the most important source category for TSP emissions (45 percent). For PM2.5, mobile sources were the largest contributor in 1990 in the EU-15 countries (31 percent). This share is expected to decline slightly by 2010 (28 percent) due to the strict regulations that were recently introduced. In the non-EU countries, industrial production processes were the largest source of PM2.5 emissions (36 percent), while in 2010 small combustion sources in the domestic sector will dominate (38 percent). The present implementation (version 1.03) of the RAINS PM module on the Internet (www.iiasa.ac.at/~rains/PM/pm-home.html) provides free access to the input data and results to facilitate interaction with national experts

The Extension of the RAINS Model to Greenhouse Gases

Many of the traditional air pollutants and greenhouse gases have common sources, offering a cost-effective potential for simultaneous improvements for both traditional air pollution problems as well as climate change. A methodology has been developed to extend the RAINS integrated assessment model to explore synergies and trade-offs between the control of greenhouse gases and air pollution. With this extension, the RAINS model allows now the assessment of emission control costs for the six greenhouse gases covered under the Kyoto Protocol (CO2, CH4, N2O and the three F-gases) together with the emissions of air pollutants SO2, NOX, VOC, NH3 AND PM. In the first phase of the study, emissions, costs and control potentials for the six greenhouse gases covered in the Kyoto Protocol have been estimated and implemented in the RAINS model. Emission estimates are based on methodologies and emission factors proposed by the IPCC emission reporting guidelines. The large number of control options for greenhouse gases have been grouped into approximately 150 packages of measures and implemented in the RAINS model for the European countries. These control options span a wide range of cost-effectiveness. There a re certain advanced technical measures with moderate costs, and certain measures exist for which the economic assessment suggests even negative costs, if major side impacts (cost savings) are calculated. Illustrative example calculations clearly demonstrate that conclusions on the cost-effectiveness of emission reduction strategies are crucially depending on the boundaries of the analysis. The net cost of greenhouse gas control strategies are significantly lower if the immediate cost-savings from avoided air pollution control costs are taken into consideration. For a 15 percent reduction of the CO2 emissions from the power sector in the EU, avoided pollution control costs could compensate two third of the CO2 control costs. Depending on the design of the control strategy, net costs of greenhouse gas mitigation could even be negative, which is in stark contrast to conclusions for a CO2 only strategy. However, there are certain greenhouse gas mitigation measures, such as increased use of biomass that could deteriorate the negative impacts of air pollution, while yielding very little economic synergies. A combined approach towards greenhouse gas mitigation and air pollution control would not only reveal economic synergies, but also harness additional environmental benefits. Even in a situation with stringent emission control requirements for air pollution as it is required by the EU legislation, modifications in fuel use geared towards reductions of greenhouse gases could lead as a side impact to significant reductions in the residual emissions of air pollutants. The economic benefits of such "windfall emission reductions" could be substantial. The extended RAINS model framework will offer a tool to systematically investigate such economic and environmental synergies between greenhouse gas mitigation and air pollution control while avoiding negative side impacts

Uncoupling GP1 and GP2 expression in the Lassa virus glycoprotein complex: implications for GP1 ectodomain shedding

<p>Abstract</p> <p>Background</p> <p>Sera from convalescent Lassa fever patients often contains antibodies to Lassa virus (LASV) glycoprotein 1 (GP1), and glycoprotein 2 (GP2); Immunization of non-human primates with viral vectors expressing the arenaviral glycoprotein complex (GPC) confers full protective immunity against a lethal challenge with LASV. Thus, the development of native or quasi native recombinant LASV GP1 and GP2 as soluble, uncoupled proteins will improve current diagnostics, treatment, and prevention of Lassa fever. To this end, mammalian expression systems were engineered for production and purification of secreted forms of soluble LASV GP1 and GP2 proteins.</p> <p>Results</p> <p>Determinants for mammalian cell expression of secreted uncoupled Lassa virus (LASV) glycoprotein 1 (GP1) and glycoprotein 2 (GP2) were established. Soluble GP1 was generated using either the native glycoprotein precursor (GPC) signal peptide (SP) or human IgG signal sequences (s.s.). GP2 was secreted from cells only when (1) the transmembrane (TM) domain was deleted, the intracellular domain (IC) was fused to the ectodomain, and the gene was co-expressed with a complete GP1 gene in <it>cis</it>; (2) the TM and IC domains were deleted and GP1 was co-expressed in <it>cis</it>; (3) expression of GP1 was driven by the native GPC SP. These data implicate GP1 as a chaperone for processing and shuttling GP2 to the cell surface. The soluble forms of GP1 and GP2 generated through these studies were secreted as homogeneously glycosylated proteins that contained high mannose glycans. Furthermore, observation of GP1 ectodomain shedding from cells expressing wild type LASV GPC represents a novel aspect of arenaviral glycoprotein expression.</p> <p>Conclusion</p> <p>These results implicate GP1 as a chaperone for the correct processing and shuttling of GP2 to the cell surface, and suggest that native GPC SP plays a role in this process. In the absence of GP1 and GPC SP the GP2 protein may be processed by an alternate pathway that produces heterogeneously glycosylated protein, or the polypeptide may not fully mature in the secretory cascade in mammalian cells. The expression constructs developed in these studies resulted in the generation and purification of soluble, uncoupled GP1 and GP2 proteins from mammalian cells with quasi-native properties. The observation of GP1 ectodomain shedding from cells expressing wild type LASV GPC establishes new correlates of disease progression and highlights potential opportunities for development of diagnostics targeting the early stages of Lassa fever.</p

Resource-Bound Quantification for Graph Transformation

Graph transformation has been used to model concurrent systems in software engineering, as well as in biochemistry and life sciences. The application of a transformation rule can be characterised algebraically as construction of a double-pushout (DPO) diagram in the category of graphs. We show how intuitionistic linear logic can be extended with resource-bound quantification, allowing for an implicit handling of the DPO conditions, and how resource logic can be used to reason about graph transformation systems

Contribution of Cystine-Glutamate Antiporters to the Psychotomimetic Effects of Phencyclidine

Altered glutamate signaling contributes to a myriad of neural disorders, including schizophrenia. While synaptic levels are intensely studied, nonvesicular release mechanisms, including cystine–glutamate exchange, maintain high steady-state glutamate levels in the extrasynaptic space. The existence of extrasynaptic receptors, including metabotropic group II glutamate receptors (mGluR), pose nonvesicular release mechanisms as unrecognized targets capable of contributing to pathological glutamate signaling. We tested the hypothesis that activation of cystine–glutamate antiporters using the cysteine prodrug N-acetylcysteine would blunt psychotomimetic effects in the rodent phencyclidine (PCP) model of schizophrenia. First, we demonstrate that PCP elevates extracellular glutamate in the prefrontal cortex, an effect that is blocked by N-acetylcysteine pretreatment. To determine the relevance of the above finding, we assessed social interaction and found that N-acetylcysteine reverses social withdrawal produced by repeated PCP. In a separate paradigm, acute PCP resulted in working memory deficits assessed using a discrete trial t-maze task, and this effect was also reversed by N-acetylcysteine pretreatment. The capacity of N-acetylcysteine to restore working memory was blocked by infusion of the cystine–glutamate antiporter inhibitor (S)-4-carboxyphenylglycine into the prefrontal cortex or systemic administration of the group II mGluR antagonist LY341495 indicating that the effects of N-acetylcysteine requires cystine–glutamate exchange and group II mGluR activation. Finally, protein levels from postmortem tissue obtained from schizophrenic patients revealed significant changes in the level of xCT, the active subunit for cystine–glutamate exchange, in the dorsolateral prefrontal cortex. These data advance cystine–glutamate antiporters as novel targets capable of reversing the psychotomimetic effects of PCP