The phrase "ascertained by determining" is correct and usable in written English.
It can be used in contexts where you are explaining how something has been established or confirmed through a process of evaluation or analysis.
Example: "The results of the experiment were ascertained by determining the variables involved and their effects on the outcome."
Alternatives: "established through analysis" or "confirmed by evaluating".
Exercise pace was ascertained by determining the number of steps taken within a quarter mile in a time duration as ascertained by the cardiac rehabilitation program.
The patient was asked about prior foot ulceration and intermittent claudication was ascertained by determining whether pain in the calves came on during walking, caused the patient to slow down or stop, and resolved with rest.
With the identification of many Cor/Lea genes, researchers concluded that a better understanding of the role of such genes in freeze resistance could be ascertained by determining how these genes are regulated at the transcriptional level.
Depletion of alveolar macrophages (AM) was ascertained by determining the cell content of bronchoalveolar lavage (BAL) isolated 72 h after liposome administration under anesthesia with an intraperitoneal injection of avertin (2.5% in PBS).
A new measure based on PRIME theory, called the risk acceptance ladder (RAL) 56 (Cattaruzza and West, 2014, in preparation) proposes that the blocks to effective behaviour change can be ascertained by determining the individual level of risk acceptance and at what stage motivation has been stalled.
The quality of the DNA sample was ascertained by electrophoresis and determined to be of high quality (size >23 kb) with no visible degradation.
Intra-rater reliability was ascertained by re-reading randomly determined subsets of 10 MRI and 10 FDG-PET scans at a separate sitting, blinded to prior rating.
The correlation between frequency of the +139 SNP in genomic rRNA (ascertained by cloning) vs that in rRNA (determined by RT-PCR and pyrosequencing) is significant (P = 0.0073), suggesting that both alleles were equally expressed.
The SPARC expression levels in tumour tissue, as determined by immunohistochemistry, was comparable to that ascertained by real-time Q-RT PCR (Pearson's correlation coefficient=0.421; P=0.008).
Thus, for the φ50 mm hydrocyclone used in this study, the lower limit (15 L/min) can be determined by the flow field stability and the upper limit (55 L/min) is largely ascertained by energy consumption.
Peripheral neuropathy was ascertained by clinical examination (knee and ankle reflex activities and feet sensation determined by Semmes-Weinstein monofilament and vibration examination with a 128-Hz tuning fork).
