The phrase "a very small activity" is correct and usable in written English.
You can use it to describe an action or task that is minor in scale or significance.
Example: "The team decided to focus on a very small activity to kick off the project before tackling the larger tasks."
Alternatives: "a tiny task" or "a minor activity".
It was suggested that very small activity of cathepsin C would be enough for being protected from periodontal infections [ 39].
In ITLC, saline was used as solvent; very small activity remained at origin corresponding to reduced 99mTc.
So it's not somebody from the outside that imposes on them to do something, but they know how to do a good job with the local resources, knowing what the local population needs, getting this money and opening very small activities, like sari-making or tailoring or even growing crops.
The prepared photocatalyst is recyclable and showed a very small change in activity after three consecutive cycles.
Of course my time there offered me only a very small snapshot of activity [a more comprehensive report can be found here ] but one encounter in particular stuck with me.
Neglect is determined in this model by a very small difference in activity in the PP module.
Only a very small boost in activity centered at Ecat2 is observed under these conditions.
All four dNTPs, as well as DNA strand breaks and, to a very small degree, APE1 activity, had higher levels with advanced age in the control group; these trends were blunted within the AD group.
Additional terms or reconfiguration of the model could obviously fix this, but we have not pursued this minor deficiency because spontaneous activity is typically a very small component of neuronal activity so it has little effect on the model's overall performance.
For K+ and NH4+ the activity profiles were bell-shaped, similar to those reported previously, whereas addition of choline had only a very small effect on HDAC8 activity.
