"extent at which" is correct and usable in written English.
You can use it to refer to the degree, scope, or measure of something. Example: Researchers are exploring the extent at which climate change is affecting ecosystems.
We assess the extent at which each signature group is facing exposure from multiple pollution types.
We developed a new model of habitat selection to detect the extent at which organisms respond to habitat.
Fallows represent important source habitat for the bug and the spatial extent at which bug abundance was affected indicates the mobility of these insects.
Then, it is fundamental to assess the appropriate extent at which landscape factors affect plant species richness at the local scale.
Our results demonstrated that only 61% of the papers identified both the grain and extent at which the research was conducted.
It is shown that the particle size and Reynolds number are preponderant factors that affect the extent at which migration occurs in the short-dwell coater.
In particular, it is important to clarify to which extent and at which price the aging process can be limited or reversed.
Studies are needed to determine to what extent and at which locations Acinetobacter genomospecies 15TU and A. radioresistens might co-reside and therefore where the blaOXA-23 gene exchange might have occurred.
Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place.
The state of mixing in a continuous flow vessel is shown to affect the extent of aggregation and the extent of aggregation at which mathematical gelation occurs.
To a large extent the speed at which enlargement will take place and the extent to which the huge problems will be overcome will depend on the preparatory work of the Dutch presidency.
