27 research outputs found

    A Case Study of the Effects of CO2-Induced Climatic Warming on Forest Growth and the Forest Sector : A. Productivity Reactions of Northern Boreal Forests.

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    The purpose of this section is to evaluate the effects of changes in climate under the GISS 2 × CO2 scenario (considered in Section 3) on the productivity of boreal forests. Some of the results reported here will be used as inputs to a further set of experiments concerned with the effect of productivity changes on forestry as an economic activity (see Section 6). Together Sections 5 and 6 provide a case study (at a hemispheric scale) of the advantages and limitations of linking biophysical and economic models in attempts to assess the effects of climatic change

    Global urban environmental change drives adaptation in white clover.

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    Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

    Present state and future perspectives of using pluripotent stem cells in toxicology research

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    The use of novel drugs and chemicals requires reliable data on their potential toxic effects on humans. Current test systems are mainly based on animals or in vitro–cultured animal-derived cells and do not or not sufficiently mirror the situation in humans. Therefore, in vitro models based on human pluripotent stem cells (hPSCs) have become an attractive alternative. The article summarizes the characteristics of pluripotent stem cells, including embryonic carcinoma and embryonic germ cells, and discusses the potential of pluripotent stem cells for safety pharmacology and toxicology. Special attention is directed to the potential application of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) for the assessment of developmental toxicology as well as cardio- and hepatotoxicology. With respect to embryotoxicology, recent achievements of the embryonic stem cell test (EST) are described and current limitations as well as prospects of embryotoxicity studies using pluripotent stem cells are discussed. Furthermore, recent efforts to establish hPSC-based cell models for testing cardio- and hepatotoxicity are presented. In this context, methods for differentiation and selection of cardiac and hepatic cells from hPSCs are summarized, requirements and implications with respect to the use of these cells in safety pharmacology and toxicology are presented, and future challenges and perspectives of using hPSCs are discussed

    RESPONSE OF 2 ATMOSPHERIC GENERAL-CIRCULATION MODELS TO SEA-SURFACE TEMPERATURE ANOMALIES IN THE TROPICAL EAST AND WEST PACIFIC

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    We present several atmospheric general circulation experiments which model the atmospheric response to SST anomalies in the tropical East and West Pacific. We have found that the extratropical response to a relatively small West Pacific anomaly can be stronger than, and qualitatively different from the response to a much larger East Pacific anomaly. These experiments suggest a possible explanation for the difference in mid-latitude response during the 1976-77 El Nino winter and the El Nino winters of 1972-73 and 1982-83.-from Author

    How best to link poverty reduction and debt sustainability in IMF-World Bank models?

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    This paper attempts to provide an economic model in the context of developing countries to address the policy strategies related to poverty reduction. With a view to deal with the shortcomings of the existing approaches as regards poverty reduction, this paper develops a model on the basis of the policy framework of the IMF and the World Bank to show how demand growth can be a crucial mechanism in determining the potential rate of growth, and then to suggest ways in which poverty—conceptualised officially in absolute terms with a subjective cut-off point (e.g. US 1/1/2 a day), and a new objective measure in terms of consumption deprivation—can be linked with the key policy variables contained in the adjustment programmes. A strategy of investment in infrastructure and in human development, and improving access to credit markets, particularly in rural areas to encourage or 'crowd in' private investment is a precondition for growth and poverty alleviation. Debt relief can only provide a temporary, not a sustainable, solution to the problem of reducing poverty.Stabilisation, growth, poverty reduction, debt sustainability,
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