Bartfield said other factors include a person's hydration, sleep duration, sleep patterns and emotions.

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Sleep duration did not significantly affect cancer risk for women of any age in the lower physical activity bracket.

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Segmenting the data industry by industry, workers reported anywhere from 24.1% (other services, except public administration) to 41.6% (mining) incidence of short sleep duration.

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Researcher Dr Michelle Miller said the findings added to the growing body of evidence suggesting that sleep duration played a key role in heart health.

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With its built-in accelerometer and microphone, the smartphone can detect the state of the user's sleep and provide detailed information about the user's sleeping habits, including the duration of sleep, the number of times the user rolls over during the night, and snoring-related information.

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To account for the sleep variable, researchers in this study kept close tabs on the duration and quality of sleep of the participants.

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