The plug is the physical and economic link that makes it possible, for the first time, to connect two nearly independent parts of our energy economy--the oil and the non-oil domains.

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It is thus early days for technologies that link the physical and virtual worlds.

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But should the link between physical expression and emotional experience bear out, it could develop into a marketing challenge for Botox marketers such as Allergan.

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Leaders should emulate this model, and pay heed to the link between mental and physical performance.

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They argued for a currency based entirely on tokens, with no link to an underlying physical commodity.

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Though a specialist in electronic notarization, he mourns the gradual disappearance of the physical signature, which he said is deliberate and easy to link to the person who made it.

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Dr Stuart Biddle, professor of physical activity and health at Loughborough University, said there was long-standing evidence to support a link between walking and mental health benefits.

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