The phrase "activity is over" is correct and usable in written English.
It can be used to indicate that a particular event or task has been completed or concluded.
Example: "After a long day of workshops and discussions, I can finally say that the activity is over."
Alternatives: "the event has concluded" or "the task is finished".
The commander of the hospital, Col. Rhonda L. Cornum, said routine medical care had been deferred "until this surge of activity is over".
To be sure, school-age children may take class trips to the New Jersey State Aquarium and the adjacent Children's Garden, or teenagers might catch a concert at the Tweeter Center, but as soon as the activity is over, visitors flee the city.
When this activity is over, the main window is shown to the user.
The catalysts containing 10 and 20 wt.% CeO2 show the best performance, i.e., peak potentials of SO2 electrooxidation are 0.06 and 0.09 V lower than Pt/C, respectively, ORR mass activity is over twofold greater, and area-specific activity is one fourth higher than Pt/C.
His personal surgical activity is over 8000 operations in general and hernia surgery.
When the concentration of Dox is increased to 1 µg/ml, the luciferase activity is over 80 times higher than that in the absence of Tet and Dox (P<0.001).
If a known enzymatic activity is over-expressed the safety of a new enzyme preparation is covered by the results of the safety studies performed for other strains from this specific Aspergillus niger strain lineage.
The GO term heat shock binding activity is over-represented in the broad without peak promoters.
Comparison of Gene Ontology (GO) terms between highly conserved, less-conserved and the divergent group of orthologs showed that "binding activity" is over-represented in all 3 groups.
Furthermore, GO-category enrichment analysis revealed that electron carrier activity is over-represented, involving only genes belonging to the cytochrome P450.
For 2 mM H2O2 addition, GO categories for RNA processing and ribosomal biogenesis are over-represented in the up-regulated genes set and oxidoreductase activity is over-represented in the down regulation set.
