473 research outputs found

    World Trade Organization Economic Research and Statistics Division More Stringent BITs, Less Ambiguous Effects on FDI? Not a Bit!

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    Disclaimer: This is a working paper, and hence it represents research in progress. This paper represents the opinions of the authors, and is the product of professional research. It is not meant to represent the position or opinions of the WTO or its Members, nor the official position of any staff members. Any errors are the fault of the author. Copies of working papers can be requested from the divisional secretariat by writing to: Economic Research an

    Coordinated optimization of visual cortical maps (I) Symmetry-based analysis

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    In the primary visual cortex of primates and carnivores, functional architecture can be characterized by maps of various stimulus features such as orientation preference (OP), ocular dominance (OD), and spatial frequency. It is a long-standing question in theoretical neuroscience whether the observed maps should be interpreted as optima of a specific energy functional that summarizes the design principles of cortical functional architecture. A rigorous evaluation of this optimization hypothesis is particularly demanded by recent evidence that the functional architecture of OP columns precisely follows species invariant quantitative laws. Because it would be desirable to infer the form of such an optimization principle from the biological data, the optimization approach to explain cortical functional architecture raises the following questions: i) What are the genuine ground states of candidate energy functionals and how can they be calculated with precision and rigor? ii) How do differences in candidate optimization principles impact on the predicted map structure and conversely what can be learned about an hypothetical underlying optimization principle from observations on map structure? iii) Is there a way to analyze the coordinated organization of cortical maps predicted by optimization principles in general? To answer these questions we developed a general dynamical systems approach to the combined optimization of visual cortical maps of OP and another scalar feature such as OD or spatial frequency preference.Comment: 90 pages, 16 figure

    Coordinated optimization of visual cortical maps (II) Numerical studies

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    It is an attractive hypothesis that the spatial structure of visual cortical architecture can be explained by the coordinated optimization of multiple visual cortical maps representing orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we defined a class of analytically tractable coordinated optimization models and solved representative examples in which a spatially complex organization of the orientation preference map is induced by inter-map interactions. We found that attractor solutions near symmetry breaking threshold predict a highly ordered map layout and require a substantial OD bias for OP pinwheel stabilization. Here we examine in numerical simulations whether such models exhibit biologically more realistic spatially irregular solutions at a finite distance from threshold and when transients towards attractor states are considered. We also examine whether model behavior qualitatively changes when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. Our numerical results support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the spatially irregular architecture of the visual cortex. We discuss several alternative scenarios and additional factors that may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with arXiv:1102.335

    Prenatal exposures and exposomics of asthma

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    This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental medi

    The Characteristics and Determinants of FDI in Ghana

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    Foreign Direct Investment (FDI) can be a valuable tool for development. However, not all forms of FDI are equally beneficial for the host country. The paper analyses the characteristics and determinants of FDI in a typical developing country: Ghana. Moreover, key policy areas are indicated, in order to enable Ghana both to attract more FDI and to increase the benefits from these capital inflows. The analysis combines qualitative and quantitative methods and is partly based on data retrieved from the World Bank's 2007 Enterprise Survey, and partly on our own survey of 54 multinational enterprises operating in Ghana

    Consequences of Economic Partnership Agreements between East and Southern African Countries and the EU for Inter- and Intra-regional Integration

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    The European Union is currently negotiating Economic Partnership Agreements (EPAs) with six African, Caribbean and Pacific country groupings, aiming at establishing mutual free trade. This paper empirically assesses the impact of the EPAs on trade flows and government revenues for 22 East and Southern African countries and discusses implications for intra-regional integration. The results indicate that while moderate trade effects can be expected, relatively large budget effects are likely to occur in a number of these countries, exposing them to considerable structural and financial adjustment requirements. Also, EPAs would strengthen the need to consolidate overlapping intra-regional integration schemes

    Global quantification of mammalian gene expression control

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    Gene expression is a multistep process that involves the transcription, translation and turnover of messenger RNAs and proteins. Although it is one of the most fundamental processes of life, the entire cascade has never been quantified on a genome-wide scale. Here we simultaneously measured absolute mRNA and protein abundance and turnover by parallel metabolic pulse labelling for more than 5,000 genes in mammalian cells. Whereas mRNA and protein levels correlated better than previously thought, corresponding half-lives showed no correlation. Using a quantitative model we have obtained the first genome-scale prediction of synthesis rates of mRNAs and proteins. We find that the cellular abundance of proteins is predominantly controlled at the level of translation. Genes with similar combinations of mRNA and protein stability shared functional properties, indicating that half-lives evolved under energetic and dynamic constraints. Quantitative information about all stages of gene expression provides a rich resource and helps to provide a greater understanding of the underlying design principles

    Globalization, Economic Freedom and Human Rights

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    Using the KOF Index of Globalization and two indices of economic freedom, we empirically analyze whether globalization and economic liberalization affect governments' respect for human rights using a panel of 106 countries over the 1981-2004 period. According to our results, physical integrity rights significantly and robustly increase with globalization and economic freedom, while empowerment rights are not robustly affected. Due to the lack of consensus about the appropriate level of empowerment rights as compared to the outright rejection of any violation of physical integrity rights, the global community is presumably less effective in promoting empowerment rights

    Trade and Economic Growth: A Re-Examination of the Empirical Evidence

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    While trade integration is often regarded as a principal determinant of economic growth, the empirical evidence for a causal linkage between trade and growth is ambiguous. This paper argues that the effect of trade in dynamic panel estimations depends crucially on the specification of trade. Both from a theoretical as well as an empirical point of view one specification is preferred: the volume of exports and imports as a share of lagged total GDP. For this trade measure, a positive and highly significant impact on economic growth can be found
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