19 resultados para Distortions


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Long-term electrocardiogram (ECG) often suffers from relevant noise. Baseline wander in particular is pronounced in ECG recordings using dry or esophageal electrodes, which are dedicated for prolonged registration. While analog high-pass filters introduce phase distortions, reliable offline filtering of the baseline wander implies a computational burden that has to be put in relation to the increase in signal-to-baseline ratio (SBR). Here we present a graphics processor unit (GPU) based parallelization method to speed up offline baseline wander filter algorithms, namely the wavelet, finite, and infinite impulse response, moving mean, and moving median filter. Individual filter parameters were optimized with respect to the SBR increase based on ECGs from the Physionet database superimposed to auto-regressive modeled, real baseline wander. A Monte-Carlo simulation showed that for low input SBR the moving median filter outperforms any other method but negatively affects ECG wave detection. In contrast, the infinite impulse response filter is preferred in case of high input SBR. However, the parallelized wavelet filter is processed 500 and 4 times faster than these two algorithms on the GPU, respectively, and offers superior baseline wander suppression in low SBR situations. Using a signal segment of 64 mega samples that is filtered as entire unit, wavelet filtering of a 7-day high-resolution ECG is computed within less than 3 seconds. Taking the high filtering speed into account, the GPU wavelet filter is the most efficient method to remove baseline wander present in long-term ECGs, with which computational burden can be strongly reduced.

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To say that regionalism is gaining momentum has become an understatement. To mourn the lack of progress in multilateral trade rule-making is a commonplace in the discourse of politicians regretting the WTO negotiation standstill, and of “know-what-to-do” academics. The real problem is the uneven level-playing field resulting from increasing differences of rules and obligations. The Transatlantic Trade and Investment Partnership Agreement (TTIP) is a very ambitious project. WTI studies in 2014 have shown that the implications for Switzerland could be enormous. But even the combined market power of the two TTIP participants – the EU and the USA – will not level the playing field impairing the regulatory framework, and the market access barriers for trade in agriculture. Such differences will remain in three areas which, incidentally, are also vital for a global response to the food security challenge to feed 9 billion people before the year 2050: market access, non-tariff barriers, and trade-distorting domestic support programmes. This means that without multilateral progress the TTIP and other so-called mega-regionals, if successfully concluded, will exacerbate rather than lessen trade distortions. While this makes farmers in rich countries safer from competition, competitive production in all countries will be hampered. Consequently, and notwithstanding the many affirmations to the contrary, farm policies worldwide will continue to only address farmer security without increasing global food security. What are the implications of the TTIP for Swiss agriculture? This article, commissioned by Waseda University in Tokyo, finds that the failure to achieve further reforms – including a number of areas where earlier reforms have been reversed – is presenting Switzerland and Swiss agriculture with a terrible dilemma in the eventuality of a successful conclusion of the TTIP. If Swiss farm production is to survive for more than another generation, continuous reform efforts are required, and over-reliance on the traditional instruments of border protection and product support is to be avoided. Without a substantial TTIP obliging Switzerland to follow suit, autonomous reforms will remain extremely fragile.

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Water-containing biological material cannot withstand the vacuum of the transmission electron microscope. The classical solution to this problem has been to dehydrate chemically fixed biological samples and then embed them in resin. During such treatment, the bacterial nucleoid is especially prone to aggregation, which affects its global shape and fine structure. Initial attempts to deal with aggregation by optimizing chemical fixation yielded contradictory results. Two decades ago, the situation improved with the introduction of freeze-substitution. This method is based on dehydration of unfixed cryo-immobilized samples at low temperature, which substantially reduces aggregation. As a result, the global shape of the nucleoid can be fairly well defined. Overall, in actively growing bacteria, the nucleoids are dispersed and "coralline" but become more confined when growth ceases. However, it is usually impossible to determine the molecular arrangement of DNA in the nucleoids of freeze-substituted bacteria because crystallization and the subsequent removal of water during substitution result in unavoidable distortions at the ultrastructural level. Recently, cryo-electron microscopy of vitreous sections has enabled the fully hydrated bacterial nucleoid to be studied close to the native state. Such studies have revealed aspects of bacterial nucleoid organization that are not preserved by freeze-substitution, including locally parallel or twisted bundles of DNA filaments, which are more frequently observed once bacterial growth has stopped, whereas in actively growing bacteria, the DNA is seen to be in a mostly disordered pattern.

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Estimates show that fossil fuel subsidies average USD 400–600 billion annually worldwide while renewable energy (RE) subsidies amounted to USD 66 billion in 2010 and are predicted to rise to USD 250 billion annually by 2035. Domestic political rationales for energy subsidies include promoting innovation, job creation and economic growth, energy security, and independence. Energy subsidies may also serve social and environmental goals. Whether and to what extent subsidies are effective to achieve these goals or instead lead to market distortions is a matter of much debate and the trade effects of energy subsidies are complex. This paper offers an overview of the types of energy subsidies that are used in the conventional and renewable energy sectors, and their relationship with climate change, in particular greenhouse gas emissions. While the WTO’s Agreement on Subsidies and Countervailing Measures (ASCM) is mostly concerned with harm to competitors, this paper considers the extent to which the Agreement could also discipline subsidies that cause harm to the environment as a global common. Beyond the existing legal framework, this paper surveys a number of alternatives for improving the ability of subsidies disciplines to internalize climate change costs of energy production and consumption. One option is a new multilateral agreement on subsidies or trade remedies (with an appropriate carve-out in the WTO regime to allow for it if such an agreement is concluded outside it). Alternatively, climate change-related subsidies could be included as part of another multilateral regime or as part of regional agreements. A third approach would be to incorporate rules on energy subsidies in sectorial agreements, including a Sustainable Energy Trade Agreement such as has been proposed in other ICTSD studies.