  This paper presents $v_{4}/v_{2}^2$ ratio as a function of transverse
momentum ($p_{t}$), pseudorapidity ($\eta$) and collision centrality in Au+Au
collisions at $\sqrt{s_{NN}} = 200$ GeV using the STAR detector at the
Relativistic Heavy Ion Collider (RHIC). It is found that $v_{4}/v_{2}^2$ is
larger than Hydrodynamic calculations, the centrality and transverse dependence
of this ratio can not be fully described by Hydrodynamics, and the
pseudorapidity dependence is opposite to what one expects from Hydrodynamics.
The $p_{t}$ dependence of $v_{1}$ is also presented. It is found that
$v_{1}(p_{t})$ for $|\eta|<1.3$ changes sign, and two possible explanations of
the sign change are discussed.
