Even missing an hour or two of sleep is enough to set vulnerable people off into an episode.

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"I never felt like something, or even more the father figure, was missing, " he said.

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It could be defects due to missing atoms, thermal vibrations of the crystal lattice, or even the boundaries between small, imperfectly formed crystals that make up the material.

ECONOMIST: MONITOR

So even if they didn't notice that she was missing meals or skipping meals, they could see the stress that this was bringing upon the family, just having to worry about food.

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Still, no Rothkos on my walls, like missing a great stock over the past five years, say Apple or Google or even IBM.

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For example, people can easily locate a missing phone by triggering the handset to ring loudly, even if it is set to silent, or to flag its location on a map.

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