It is, however, a plausible hypothesis, and there is some evidence that their autonomic nervous systems (which control basic bodily functions such as heartbeat and body temperature) have not been working properly.

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Rafa regains control but looks nervous and two poor drop volleys prevent him from seeing out the game.

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In recent years, he also suffered from Shy-Drager, a condition similar to Parkinson's disease that attacks the nervous system and affects muscle control.

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Be aware of your nervous habits and try to control them.

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Any time there's a new technology that empowers the consumer, some people in the industry get nervous because it's all about control, and there are a lot of people in the industry who don't want to see the consumer have control.

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Heart-rate variability, says Dr Stein, is a good index of the degree of control an individual has over his autonomic nervous system (which controls many of the internal organs).

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Applying an electric current and getting a muscle to jump is easy. (Alessandro Volta jolted a frog's legs 218 years ago.) Peckham is harvesting the body's own electrical signals to control muscles that have been cut off from the nervous system, a process called functional electrical stimulation, or FES. Peckham runs a group called the Cleveland FES Center, a collaboration among Case Western Reserve and two Cleveland hospitals.

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When seat belts were introduced, when airbags were introduced, cruise control, there were a lot of people who were nervous about it.

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