The phrase "activity at the beginning" is correct and usable in written English.
It can be used to refer to an action or event that occurs at the start of a process or timeline.
Example: "The activity at the beginning of the project was crucial for setting the right tone and direction."
Alternatives: "initial activity" or "beginning task".
Stability of GadB was evaluated by the ratio (relative activity) of the residual GadB activity at different time points to the activity at the beginning.
We measured the level of AT activity at the beginning (basal AT), daily, and at the moment of circuit coagulation.
He had to limit his activity at the beginning of camp, receiving extensive treatment and taking anti-inflammatory drugs.
Meatpacking was a major industrial activity at the beginning of the 20th century, but aircraft manufacturing, begun in the 1920s, soon dominated Wichita's economy.
An effective activity at the beginning of the lesson reminded students of what they knew so far about the homes and lifestyle of the Sioux Indians, especially in relation to buffalo hunting.
Mr Draghi, speaking in Cyprus where the ECB held this month's meeting, said: "The latest economic data... point to some further improvements in economic activity at the beginning of this year.
The reasons might be that autoclaved poplars (detrital organic matter) were susceptible to the growth of microorganisms during the experiment, even though there were few microorganisms (very low activity) present at the beginning.
In fact, very few of the activities at the beginning of October are credible except upon the assumption that the French and British governments knew that something was going to happen in Egypt.
Thereby, we tested two MCCP variants with different initial mineralization activities at the beginning of the soil inoculation experiment.
Students are typically assigned these activities at the beginning of the summer and are typically graded (for completion) at the start of the next school year.
