Retrieval of the particle size distribution function from the data of lidar sensing under the assumption of known refractive index.

This paper presents a method to retrieve the particle size distribution function from the data of vertical lidar sensing. We have used 462 data models obtained at the Zvenigorod AERONET site obtained in 2011-2012. For each laser shot, we considered both fine (with particle sizes in a range from 0.05 to 0.6 µm) and coarse aerosol fractions (from 0.6 to 10 µm), with emphasize on the coarse fraction. Our suggested method is a modification of the Tikhonov method. The Tikhonov method is not optimal for coarse particles because its stabilizer does not and cannot account for the presence of the coarse mode, i.e., existence of more than one maximum of the size distribution function. The components of the matrix Wu-1 located in quadrants II and IV are sensitive to the change of these parameters. Neglecting this fact will lead again to arbitrary estimates of the contribution of the coarse particles even for exact values on the main diagonal and the two diagonals adjacent to it. Our method allows the coarse fraction up to 2.5 µm to be determined unambiguously. For larger particles (>2.5 µm) we recommend using the available sets of the coefficients, but with the level of values to be determined.

Special report on reimbursement. HCFA enacts new enforcement remedies covering nursing facilities.

While the regulations are revolutionary in their use of "substantial compliance," the interpretation and application of HCFA's new remedial scheme are still uncertain, as states are given broad discretion in defining important terms and in applying and interpreting the criteria to select remedies. Further complicating the issue is the fact that some states, including California, intend to seek waivers from HCFA to substitute their own state enforcement systems for most, if not all, of the new federal system. Based upon these uncertainties, the enforcement of nursing facility standards will likely be in a state of flux for some time to come.

Federal court's decisions will clarify the Health Care Quality Improvement Act.

Peer reviewers are anxiously awaiting the decision of the U.S. Court of Appeals for the Ninth Circuit in two antitrust cases. Both cases, Smith v. Ricks and Fobbs v. Holy Cross Health System Corp., were fully briefed and argued on the same day earlier this year, and the decisions are expected sometime this summer. In both matters, the court is expected to flesh out the meaning of the Health Care Quality Improvement Act of 1986, commonly known as "HCQIA." Based on contemporary press accounts of the parties' oral arguments before the court, however, it is uncertain whether the decisions will strengthen or weaken medical staff peer review.