The phrase "are often uncertainties" is correct and usable in written English.
It can be used when discussing situations or topics that typically involve doubt or lack of clarity.
Example: "In scientific research, there are often uncertainties regarding the results and their implications."
Alternatives: "frequently involve doubts" or "often present ambiguities".
However, there is often uncertainties in the choice of recognizable splice signals, resulting in a process termed alternative splicing [ 17], which enables the origination of multiple mRNA transcript variants from a single gene locus [ 67- 69].
Predicting the vibration response of complex nonlinear structures is a significant challenge: the response may involve many modes of the structure; nonlinearity precludes the use of efficient techniques developed for linear systems; and there is often uncertainty associated with the nonlinear law, even to the extent that its functional form is not always known.
There's often uncertainty around alleged hacks, with some in the crypto community claiming an inside job for most incidents.
At least in the Australian context, there is often uncertainty about the date of release from custody, which complicates transitional planning and adds an extra element of stress to the release experience.
There's often uncertainty around the use of the term terrorism, which has distinct legal and colloquial definitions, and many read Sessions' comments as an indication that a terrorism charge was a possibility.
Tonkin-Crine et al. [ 6] found that there was often uncertainty around RTI diagnosis and management in primary care, which was also identified in LTCFs.
There is often uncertainty of whether patients with poor PS would benefit from the treatment to the same extent to patients with better PS.
As there is often uncertainty about a child's illness trajectory, children's palliative care may combine palliative care with cure oriented treatment.
