Furthermore, as a recent Institute of Medicine report makes clear, it will be difficult to gauge the magnitude of any effect and the mechanism responsible.

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They were then able to give the mice higher doses of radiation therapy with no ill effect by blocking a mechanism by which endothelial cells communicate with each other.

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However, Professor Grant said the molecular mechanism behind the effect was not known.

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If, as seems likely, the CWC has the effect of vitiating the Australia Group mechanism, CW-relevant exports may be permitted even to dubious customers -- but it will be hard to contend that the effect on curbing proliferation of chemical weapons will be a positive one.

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If that confounding variable can be taken care of, though, and the effect persists, the next obvious step is to determine what mechanism within the mother's body causes the discrepancy.

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Countries will make an additional 200 billion euros available to the International Monetary Fund so it has resources to deal with the crisis, and the European Stability Mechanism, a new bailout fund, will go into effect sooner than previously planned.

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It has been suggested in previous studies that there could be a link between impaired lung function and a negative effect on the thinking processes, but it is not clear what the mechanism for that might be.

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The other main mechanism through which falling equity prices affect the real economy is the wealth effect on consumers.

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They note that it hits only one unproven mechanism behind stroke and that it may be necessary to hit multiple biological pathways to get a significant effect.

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