The phrase "are occasionally not" is correct and usable in written English.
It can be used to indicate that something does not happen at certain times or under certain conditions.
Example: "The results of the experiment are occasionally not what we expected, leading to further investigation."
Alternatives: "are sometimes not" or "are infrequently not".
Importantly, splice donor 1 is present in all sequences, even if some are occasionally not processed.
Bone mineral density measurements provide the single best method for predicting fracture risk [ 5] but densitometers are occasionally not available and since the pathogenesis of fragility fractures is multifactorial, bone mass is not the only factor that determines risk.
However, it is generally recognized that there are relatively few clinical differences among the different spotted fever diseases, and these differences are occasionally not taken into account by clinicians when reporting clinical data of patients (12 ).
In addition, it appears that systemic therapies are occasionally not applied in situations where they are needed due to the increased effort involved in monitoring the patients for unwanted side effects and possible interactions with other drugs.
The truth is, I'm not even sure what she's apologising for, except that I'm occasionally not that chatty.
However, preliminary analyses indicated that ϕ can be difficult to calculate for some crown architectures and it is occasionally not calculable for others due to its asymptotic form.
However, immediate removal is occasionally not possible because of the patient's condition or the dentist's lack of technical experience.
The graphics were occasionally not up to the screen's capabilities; the 3.5G indicator especially was a bit fuzzy, and I learned to recognize it by its indistinctness.
IL-1β and TNF-α mRNA was constitutively expressed whereas IL-6, IL-10 and IL-12 p40 mRNA was generally expressed at a lower level and was occasionally not detected.
However, the equation used by Duursma and Mäkelä ([2007]) was developed for a single k H and while the equation used by Forrester ([2014]) included a range of k H, it approached an asymptote and preliminary analyses showed that it could not provide adequate estimates of ϕ for some crown architectures and was occasionally not calculable for others due to its asymptotic form.
