On the Determination of the Mean Cosmic Matter Density and the Amplitude   of Density Fluctuations
  The cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density and the amplitude of mass density fluctuations currently do not appear unreasonable observationally. 
Thomas H. Reiprich (UVa)