GAPDH proved to be a valid control as GAPDH and cell proliferation were linearly correlated (supplemental data).
The flaw in this grazing experiment is that the control treatment, a pasture not treated with sewage sludge, is not a valid control.
Together the findings in those studies clearly indicate that associating subjects with one of the proposed archetypes of distributional concerns has explanatory value and that the proposed test is indeed a valid control instrument in experimental economics.
The results demonstrate that the method proposed in this paper is a valid and efficient design tool for controlling smoke in UTLTs.
In another one [39], the appliance was not used exclusively in patients with anterior open bite and there was not a valid control group.
Test-negative ILIs are therefore a valid control group (the source population of cases).
This study was designed to determine whether digital intubation is a valid option for definitive airway control by emergency physicians.
The treadmill is a valid and reliable instrument for controlling different levels PA that is widely used in calibration studies [ 12- 14].
Our findings support the view that the nested case-control study is a valid and efficient design for diagnostic studies.
'Damage control' and packing is a valid concept in the treatment of severely injured patients with hemorrhage [ 4].
