Second, the VAP prevention measures were not reported in most trials, and it is difficult to ascertain if they were applied, especially that most included trials were conducted prior to recent advances in VAP prevention.
While it can be argued that behavior at the neuronal level may propagate to the voxel level, the most appropriate scale has been difficult to ascertain [40], [41].
From our dataset, it is difficult to ascertain most of these conditions, but when eliminating all patients who had received inhalative corticosteroids or beta mimetics, the percentage of BB users increased slightly to 75.4% from 74.0% in the overall population.
Other, more subtle differences were observed in multiple marks across different conditions; however, given the ECL amplification approach used in most standard immunoblotting approaches, along with the performance of most commercial polyclonal antibodies, it is difficult to ascertain whether such differences are biologically significant.
The degree to which this hampers or slows down research is difficult to ascertain, but most certainly this has a role.
The risk for disease transmission is difficult to ascertain because most studies, including this one, have not measured viability of the parasites recovered from water or filter backwash.
The incidence of A. variabilis in humans is unknown and difficult to ascertain because most cases had isolates that were not properly preserved.
Presently it is still difficult to ascertain the most ancient class of cGSTs, with theta and omega being the best candidates.
The variability of levels of pesticide in household dust according to season and spraying activity has not been well established and would be difficult to ascertain in most agricultural communities because field-specific information on product name, amount applied at each location, and the crop type are not available.
Although Lincoln's storytelling is well known, it is more difficult to ascertain which stories he most likely told, as opposed to the many ascribed to him.
