The phrase "ascertained since" is not correct and does not convey a clear meaning in written English.
It may be intended to indicate that something has been determined or established from a certain point in time, but the phrasing is awkward.
Example: "The results have been ascertained since the beginning of the study."
Alternatives: "determined since" or "established since".
Failure modes could not be ascertained, since the experiments were stopped due to limitations in test set-up.
The specific duration of illness for participants in these studies was unable to be ascertained, since reporting on this detail was insufficient, but most report chronic patients.
The contribution of ultrafiltration to the overall clearance of vancomycin and gentamicin was unable to be ascertained since the ultrafiltration rate of 300 mL/hr was held constant.
However, the outcome from severe muscle toxicity could not be ascertained since there is no information of death record in the database.
Examination of the TIGR Plant Transcript assemblies [ 73] indicates that these genes are also present throughout angiosperms, although exact copy number cannot be ascertained since EST assemblies are not an accurate estimate of copy number.
The precise degree to which public opinion influences decision-making cannot be ascertained, since there is no method to separate this source of influence from many other sources of influence (eg, lobbying, scientific evidence and Government white papers).
But even if the Solomons had taken the case to small claims court, they would have had to file the claim in the municipality where the chimney company was located, which was not easy to ascertain since the business used a toll-free phone number and is outside of Westchester County.
The accuracy of the forecastle has been more difficult to ascertain since none of it remains; conflicting interpretations of what it looked like have been suggested.
The PRC type is interesting to ascertain since it can provide insights into the neuron's synchronization behavior.
And to ascertain since when it is established, powerful epidemiological studies in human and canine population must be done.
This question is experimentally difficult to ascertain, since the two reactions are catalyzed by the same enzyme.
