Taking account of difficulty of collection, the Confederate Congress passed a "Tax in Kind" in April 1863, which was set at one tenth of all agricultural product by state.
Compared with genetic study of T2D, the progress of genetic study of DN has been slowed down mainly due to the difficulty of collection and characterization of subjects [ 31].
The lack of prior reports on the activity of AP in NS is likely to be due to the difficulty of collection of sufficient volumes of this fluid from animals such as laboratory rodents and reluctance of human volunteers to undertake NS collection.
Most importantly, information about the chemical composition and microbial community structure of the floating layer is lacking due to the difficulties of sample collection in full-scale digesters.
Apart from the difficulties of data collection in conflict zones should be added the fear, often justifiable, of providing information which could be misused in the future.
However, this has long been a challenging endeavour, as insurgency imposes specific limitations on the data that could speak to these interactions: quantitative data is limited by the difficulties of systematic collection in war, while qualitative data may include vague or conflicting insights from direct observers.
Tropical infectious diseases diagnosis and surveillance are often hampered by difficulties of sample collection and transportation.
We are not aware of any studies that provided such comprehensive evaluation for assessing dispersion model predictions due partially to the difficulties of data collection.
Because of the technical difficulties of urine collection over a 24-h period, the urinary clearance of creatinine has been reported to be less reproducible, even in comparison with eGFR [ 1, 32].
