On Linear Transmission Systems

This thesis is divided into two parts. Part I analyzes the information rate of single antenna, single carrier linear modulation systems. The information rate of a system is the maximum number of bits that can be transmitted during a channel usage, and is achieved by Gaussian symbols. It depends on the underlying pulse shape in a linear modulated signal and also the signaling rate, the rate at which the Gaussian symbols are transmitted. The object in Part I is to study the impact of both the signaling rate and the pulse shape on the information rate. Part II of the thesis is devoted to multiple antenna systems (MIMO), and more specifically to linear precoders for MIMO channels. Linear precoding is a practical scheme for improving the performance of a MIMO system, and has been studied intensively during the last four decades. In practical applications, the symbols to be transmitted are taken from a discrete alphabet, such as quadrature amplitude modulation (QAM), and it is of interest to find the optimal linear precoder for a certain performance measure of the MIMO channel. The design problem depends on the particular performance measure and the receiver structure. The main difficulty in finding the optimal precoders is the discrete nature of the problem, and mostly suboptimal solutions are proposed. The problem has been well investigated when linear receivers are employed, for which optimal precoders were found for many different performance measures. However, in the case of the optimal maximum likelihood (ML) receiver, only suboptimal constructions have been possible so far. Part II starts by proposing new novel, low complexity, suboptimal precoders, which provide a low bit error rate (BER) at the receiver. Later, an iterative optimization method is developed, which produces precoders improving upon the best known ones in the literature. The resulting precoders turn out to exhibit a certain structure, which is then analyzed and proved to be optimal for large alphabets

Convergence and Inequality of income: the case of Western Balkan countries

This paper analyses the convergence process of inequality in income among five Balkan countries in the 1989-2008 period. This study is carried out in comparison with the situation in the European Union of 27 countries. The originality of our approach is to consider the convergence of countries' contributions to the international income inequality. The model allows simultaneously to test the convergence process of income and inequality. The results indicate a real convergence process between Balkan countries, while persistence is detected between European Union countries. However, the thorough investigations stress that there are differences in the pace of convergence across sub-periods. Thus, income and inequality convergence are higher during the 2000s for the EU-27, while the majority of convergence took place during the second half of the 1990s for Balkan countries. Accordingly, the development gap between Balkans and European Union remains important.Convergence, Inequality, Panel Data, Balkan countries, European Union

Human Well-being, Ecosystem Services And Watershed Management In The Credit River Valley: Web-distributed Mechanisms And Indicators For Communication And Awareness

This project is one section of a larger project undertaken between researchers at York University and the Credit Valley Conservation Authority (CVC). The ultimate goal of the project is to identify links between human health and natural ecosystems, and incorporate these connections into a web-based decision making tool that can be used by planners, ecologists and policy makers at CVC. The following paper provides background information about the project as well as the concept of ecosystem approaches to health or ‘ecohealth’. The larger project uses the framework and vocabulary of ecosystem services as defined by the Millennium Ecosystem Assessment in order to define and describe the connections that exist between natural ecosystems and human health. This framework is described and critiqued in the paper. Finally, three toolkits are presented that specifically describe the relationship between a proposed intervention upon the landscape and the consequences it would have for human health in the surrounding area. Each toolkit contains a completed matrix based upon the cascade model of ecosystem services that shows the progression from intervention to human health benefit

Treatment of arthritis with tumour necrosis factor antagonists. Clinical, immunological and biochemical aspects

Abstract The treatment of arthritis has undergone a dramatic change since biological agents targeting specific mediators of the disease process have been introduced. Tumour necrosis factor (TNF) antagonists have been shown to reduce signs and symptoms of disease and to retard the development of tissue damage in the majority of patients. This thesis focuses on clinical, immunological and biochemical aspects of treatment with TNF antagonists in patients with arthritis. In particular, the studies examine: (i) the feasibility of a structured protocol with central data handling for the prospective monitoring treatment efficacy and tolerability of new treatments in clinical practice, (ii) whether serum levels of cartilage oligomeric matrix protein (COMP) change during treatment with TNF antagonists in a way that corroborates a tissue protective effects of these agents in rheumatoid arthritis (RA), (iii) how different anti-rheumatic treatments modulate the immune response induced by polysaccharide or polypeptide vaccines in patients with RA and (iv) potential predictors of infusion reactions during treatment with infliximab. All the patients who participated in the studies were monitored according to a standardised clinical protocol of the South Swedish Arthritis Treatment Group (SSATG) developed at the Department of Rheumatology in Lund. We found that such a protocol could be used for monitoring newly introduced anti-rheumatic treatments both at a university department and at other rheumatology units. The performance of TNF antagonists regarding efficacy and safety complied with results of previously published clinical trials. Serum levels of COMP were measured in RA patients treated with infliximab and etanercept during the initial 6 months of treatment. Serum COMP levels decreased in patients with and without a clinical response, suggesting a damage retarding effect of TNF antagonist treatment. Altogether, 149 patients with RA participated in studies of the immune response to pneumococcal or influenza vaccination. Patients treated with TNF antagonists and controls showed similar responses to pneumococcal vaccine, whereas methotrexate treated patients showed reduced response to this vaccine regardless of concomitant treatment with TNF antagonists. In contrast, RA patients treated with methotrexate without TNF antagonists had significantly better immune response to influenza vaccination than those receiving TNF antagonists alone or in combination with methotrexate and/or other disease modifying antirheumatic drugs. Possible predictors of infliximab related infusion reactions were studied in a cohort of 213 patients with RA and 76 patients with spondylarthropaties. Infliximab without methotrexate and positive baseline ANA (antinuclear antibodies) were independent risk factors for developing infusion reactions in RA but not in spondylarthropaties. In conclusion, a structured protocol with central data handling is feasible in clinical practice for documenting the efficacy of and adverse events associated with drugs used for the treatment of arthritis. Serum COMP has the potential to be a useful marker for evaluating tissue effects of novel treatment modalities in RA. Methotrexate treatment in RA reduces antibody response to pneumococcal vaccine, suggesting that RA patients should be vaccinated before the initiation of his treatment. The immune response to influenza vaccination is sufficiently good to warrant vaccination of all RA patients, regardless of treatment. Positive ANA at initiation of infliximab treatment and the use of infliximab as monotherapy is associated with increased risk of infusion reactions in RA