### Summary Using uncompressed nifti, nibabel opens up the images as ```memmap``` objects ### Actual behavior A trait error is raised because the value is not purely float ### Expected behavior The trait successfully accepts a float ### How to replicate the behavior Calling ComputeDVARS with an uncompressed nifti ### Platform details: Only happens with nipype<1.12.0 ~~Any platform~~ Please see https://github.com/poldracklab/mriqc/issues/356