The phrase "activity can be observed" is correct and usable in written English.
It can be used in contexts where you want to indicate that a particular action or behavior is visible or detectable.
Example: "In this experiment, the activity can be observed through the changes in temperature."
Alternatives: "activity is noticeable" or "activity is detectable."
In fact, upon activation, elevated CD39 activity can be observed also in CD4+Foxp3(GFP)− cells activated by plate-bound anti-CD3/CD28 (data not shown), but these cells do not produce adenosine as they do not express CD73.
We have previously reported that a gradient of aPKC activity can be observed in the P6 retinal vasculature, with the highest activity of aPKC observed in the vascular plexus17.
This situation has changed dramatically in recent years with the advent of novel tools for targeting genetically distinct interneuron types so their activity can be observed and manipulated.
This formulation widened the realm of sexuality beyond reproduction, by proposing that genital activity does not encompass all of sexuality, because sexual activity can be observed long before biological maturity and can occur without leading to reproduction.
At pH > 3 a transition from the reversible to irreversible behaviour and a decreasing electrochemical activity can be observed, as well as the anion exchange is replaced by cation exchange during the electrochemical transformations.
New funding has allowed the project to undertake a large survey of the Cothi and Gwenffrwd valleys to assess where squirrel activity can be observed and to engage landowners and other interested individuals in red squirrel conservation.
When not connecting sexually frustrated people, John whiles away his hours pining over a pretty woman whose activities can be observed 24 hours a day on her own Webcam site.
Thus, high activities can be observed for β-amino acids with small side groups, e.g. β-amino-n-butyric acid, but not for large side chains like the aromatic ring of β-phenylalanine.
While the absence of any street life can have various reasons, such as security concerns or introverted lifestyles rooted in cultural particularities, the actual activities can be observed and evaluated to gather in-depth insights if public urban spaces are perceived as attractive or repulsive surroundings.
Greater coherence between UK and local risk perceptions and DRM activities can be observed from 2001 onwards with the development of a strategy to sustain the on-island community and promote long-term investment in the north of the island (Clay et al. 1999: 13).
