The effect of screening on the $x$ and $Q^2$ bhaviour of $F_2$ slopes
  A systematic study of $\frac{\partial F_2(x,Q^2)}{\partial \ln Q^2}$ and $\frac{\partial \ln F_2(x,Q^2)}{\partial \ln (1/x)}$ is carried out in pQCD taking screening corrections into account. The result of calculations, which are different from the non screened DGLAP prediction, are compared and shown to agree with the available experimental data as well as a pseudo data base generated from the ALLM'97 parameterization. This pseudo data base allows us to study in detail our predictions over a wider kinematic region than is available experimentally, and allows us to make suggestions for future experiments. Our results are compared with the GRV'94 parameterization (which is used as an input for our calculations) as well as the recently proposed MRST structure functions. 
E.Gotsman (Tel Aviv Un.), E.Levin (Tel Aviv Un./DESY), U. Maor (Tel   Aviv Un.) and E.Naftali (Tel Aviv Un.)