Figure 5 From: Real-time phase-contrast x-ray imaging: a new technique for the study of animal form and function R 2 min as a function of incident beam power density. R2 min is the ratio of mean CO2 emission rate during the 2 minutes after 'beam on' divided by the mean CO2 emission rate during the 2 minutes before 'beam on'. Error bars denote standard deviation; numbers below each data point correspond to sample sizes. The 25 keV x-ray beam was incident on the head.Back to article page