10,584 research outputs found

    The Modernization of EC Antitrust Policy. A Legal Cultural Revolution

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    regulation; competition policy; Treaty on European Union

    Population genetics of translational robustness

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    Recent work has shown that expression level is the main predictor of a gene’s evolutionary rate, and that more highly expressed genes evolve slower. A possible explanation for this observation is selection for proteins which fold properly despite mistranslation, in short selection for translational robustness. Translational robustness leads to the somewhat paradoxical prediction that highly expressed genes are extremely tolerant to missense substitutions but nevertheless evolve very slowly. Here, we study a simple theoretical model of translational robustness that allows us to gain analytic insight into how this paradoxical behavior arises.Comment: 32 pages, 4 figures, Genetics in pres

    Thermodynamics of Neutral Protein Evolution

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    Naturally evolving proteins gradually accumulate mutations while continuing to fold to thermodynamically stable native structures. This process of neutral protein evolution is an important mode of genetic change, and forms the basis for the molecular clock. Here we present a mathematical theory that predicts the number of accumulated mutations, the index of dispersion, and the distribution of stabilities in an evolving protein population from knowledge of the stability effects (ddG values) for single mutations. Our theory quantitatively describes how neutral evolution leads to marginally stable proteins, and provides formulae for calculating how fluctuations in stability cause an overdispersion of the molecular clock. It also shows that the structural influences on the rate of sequence evolution that have been observed in earlier simulations can be calculated using only the single-mutation ddG values. We consider both the case when the product of the population size and mutation rate is small and the case when this product is large, and show that in the latter case proteins evolve excess mutational robustness that is manifested by extra stability and increases the rate of sequence evolution. Our basic method is to treat protein evolution as a Markov process constrained by a minimal requirement for stable folding, enabling an evolutionary description of the proteins solely in terms of the experimentally measureable ddG values. All of our theoretical predictions are confirmed by simulations with model lattice proteins. Our work provides a mathematical foundation for understanding how protein biophysics helps shape the process of evolution

    Hawking radiation from decoherence

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    It is argued that the thermal nature of Hawking radiation arises solely due to decoherence. Thereby any information-loss paradox is avoided because for closed systems pure states remain pure. The discussion is performed for a massless scalar field in the background of a Schwarzschild black hole, but the arguments should hold in general. The result is also compared to and contrasted with the situation in inflationary cosmology.Comment: 6 pages, to appear in Class. Quantum Gra

    Gender differences in place attachment and residential mobility

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    Dual Labour Markets and Menu Costs: Explaining the Cyclicality of Productivity and Wage Differentials

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    The conventional menu cost framework performs poorly with realistic labour supply elasticities; the menu costs required for price rigidity are very high and the welfare consequences of monetary disturbances are negligible. We show that the presence of dual labour markets greatly improves the performance of the framework both by reducing menu cost requirements and by boosting the welfare consequences. In addition, the introduction of dual labour markets provides an explanation of procyclical productivity and the shrinking of wage differentials during booms, in line with stylized facts on business cycles.
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