Assume that we have a $1$ dimensional foliation of $\mathbb{R}^2$. Is there a global diffeomorphism of the plane which maps all leaves of the foliation to curves with non zero curvature? One can consider the same question for a $1$ dimensional foliation of $\mathbb{R}^n$ requiring that all leaves to be transform ed to Frenet curves. A motivation for this question: When I was thinking to the following question, I was thinking to the orthonormal frame $\{\gamma',\gamma'' \}$ as a possible resolution to find a metric compatible to our vector field: https://mathoverflow.net/questions/160945/limit-cycles-as-closed-geodesicsin-negatively-or-positively-curved-space