The phrase "ascertain at" is not correct and does not convey a clear meaning in written English.
It is unclear what context you are trying to use it in, as "ascertain" typically requires a direct object to indicate what is being determined.
Example: "We need to ascertain the facts before making a decision."
Alternatives: "determine" or "find out".
Michael Mansfield Very difficult to ascertain at the moment the extent to which the media has truly changed its spots.
A secondary goal was to ascertain at what timepoint the DPP assay line reverted to negative after treatment.
"I don't know how anyone could ascertain at this point whether this is good or bad for the American citizenry," the Tennessee senator said on Fox News.
In an unsuccessful effort to ascertain at least which propositions are unsolvable, the English mathematician and logician Alan Turing rigorously defined the loosely understood concept of an algorithm.
Exactly how that is going to be achieved was rather more difficult to ascertain at a club who run football's most perfunctory media operation, Mourinho stopping long enough only to attack as "lies" reports that he is at odds with his players.
Its manifest purpose is to require every person dealing in drugs to ascertain at his peril whether that which he sells comes within the inhibition of the statute, and if he sells the inhibited drug in ignorance of its character, to penalize him.
The study cohort comprised diffuse large B-cell lymphomas (173 cases) consecutively ascertained at the Memorial Sloan-Kettering Cancer Center between 1989 and 2008.
The number of lives lost so far as can be ascertained at present is 16.
The latter were classified as "long-term" if they were ascertained at least 6 months after birth.
Appetite assessment and dietary energy and protein intakes using a 2-day diet diary assisted recall are ascertained at baseline and on a yearly basis.
From October 1 , 1995to September 30 , 1996all injury-related ED visits among District of Columbia residents <3 years of age were ascertained at the 10 hospitals where city children routinely sought care.
