Detecting the orientation of long links by finite type invariants
  We prove the existence of a degree 7 Vassiliev invariant of long (or string) two-component links which is not preserved under the simultaneous change of orientation of both components. The non-invertibility of this invariant can be detected by the standard weight system with values in the tensor square of the universal enveloping algebra for $\gl(n)$. 
S.V.Duzhin, M.V.Karev