We investigate a class of triangular UHF algebras which have the special property that there exists a sequence of unital multiplicative contractive finite-rank conditional expectations of the algebra into itself, which converges strongly to the identity, whose ranges form an increasing chain with dense union. A partial classification is given in terms of a local finiteness property, and a delimiting counterexample is obtained. Associated inverse limit algebras are considered, and a characterization of residually finite dimensional triangular AF algebras is obtained.

1991 Mathematics Subject Classification: 47D25, 46J35.

We prospectively studied 190 patients undergoing tonsillectomy or nasal surgery to assess the value of two structured interview techniques. There were four groups: Group A did not have a consent interview during the study period. Group B had an informal interview. Group C had a structured interview and Group D had a structured interview and were given an information sheet. Anxiety assessments were made and patients' recall of the operation name, details of the operation and its complications was assessed.

Patients had higher than normal anxiety levels when admitted, but several hours after the interview anxiety was normal for Groups B, C and D. Group A maintained a higher anxiety level.

Only 37 per cent correctly recalled the operation name, where as 87 per cent of all groups recalled the explanation of the operation. However, Groups C and D recalled a higher mean number of complications per patient.

A structured interview when obtaining informed consent increases the number of complications recalled without increasing pre-operative anxiety.