Another challenge with in vivo measurements is the difficulty of measuring enzyme and intermediate enzyme complex concentrations [ 7, 8], so these are typically unknown.
In conclusion, this comparison suggests confidence in the 5S measurements, but also illustrates the difficulty of measuring the repeats.
Because of the difficulty of measuring the brain, psychiatric diagnoses are still mainly based on symptoms.
Much of the variance is due to the great difficulty of measuring cosmic distances.
And unlike a tape measure, they eliminate the difficulty of measuring tall walls and hard-to-reach areas.
The difficulty of measuring the success of dropout prevention programs is not unique to Texas.
Yes, of course: the difficulty of measuring productivity in services, now most of the economy, is well-known.
The relative price effect is somewhat subjective, however, because of the difficulty of measuring the quality of goods and services.
One of the barriers to sustainability in global value chains is the sheer scale of them, and the difficulty of measuring and standardising within such a broad concept.
Part of corporate resistance to experimenting with hands-on activities comes from the difficulty of measuring the value of paying employees to, say, build a go-cart or a radio set while in the office.
But if China and India are 40% smaller than previously thought, world growth would be trimmed to 4.5%.The difficulty of measuring PPP is one reason why some economists prefer to compare the sizes of economies using market exchange rates.
