72 research outputs found

    International Emission Policy with Lobbying and Technological Change

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    I examine the implementation of emission policy in a union of countries. Production in any country incurs emissions that pollute all over the union, but efficiency in production can be improved by research and development (R&D). I compare four cases: laissez-faire, Pareto optimal policy, lobbying with centrally-determined emission quotas and lobbying with emission trade. The main findings are as follows. With emission quotas, the growth rate is socially optimal, but welfare sub-optimal. Emission trade speeds up growth from the initial position of laissez-faire, but slows down from the initial position of centrally-determined emission quotas

    Population density and group size effects on reproductive behavior in a simultaneous hermaphrodite

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    <p>Abstract</p> <p>Background</p> <p>Despite growing evidence that population dynamic processes can have substantial effects on mating system evolution, little is known about their effect on mating rates in simultaneous hermaphrodites. According to theory, mating rate is expected to increase with mate availability because mating activity is primarily controlled by the male sexual function. A different scenario appears plausible in the hermaphroditic opisthobranch <it>Chelidonura sandrana</it>. Here, field mating rates are close to the female fitness optimum, suggesting that mating activity remains unresponsive to variation in mate availability.</p> <p>Results</p> <p>Applying an experimental design that aims at independent experimental manipulation of density and social group size, we find substantial increases in mate encounter rate with both factors, but no statistically detectable effects on mating rate in <it>C. sandrana</it>. Instead, mating rate remained close to the earlier determined female fitness optimum.</p> <p>Conclusions</p> <p>We demonstrate that mating rate in <it>C. sandrana </it>is largely unresponsive to variation in mate availability and is maintained close to the female fitness optimum. These findings challenge the prevailing notion of male driven mating rates in simultaneous hermaphrodites and call for complementary investigations of mating rate effects on fitness through the male sexual function.</p

    Dynamic Systems, Economic Growth, and the Environment

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    The book focuses on the sustainability of economic growth in a changing environment, under the effect of global warming, dwindling energy resources, and technological change. It also provides explanations for significant fluctuations in countries' growth rates. The results are derived from historical evidence on economic growth in relation to environmental policy, technological change, development of transport infrastructure, population issue, and environmental mortality. The rigorous analysis of theoretical and applied aspects reveals important policy implications for optimal investment, optimal timing of abatement activities, and for an optimal balancing of economic growth with environmental concerns

    Green Growth and Sustainable Development

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    The book examines problems associated with green growth and sustainable development on the basis of recent contributions in economics, natural sciences and applied mathematics, especially optimal control theory. Its main topics include pollution, biodiversity, exhaustible resources and climate change. The integrating framework of the book is dynamic systems theory which offers a common basis for multidisciplinatory research and mathematical tools for solving complicated models, leading to new insights in environmental issues

    Direct bonding of oxidized cavity wafers

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