Tests of the efficiency of an augmented distorted planewave basis in electronic structure calculations.

An augmented distorted planewave plus local orbital basis set has been developed and implemented in a simple fashion in order to test its efficiency for electronic structure calculations. It is based on the idea of using distorted planewaves (Gygi 1993 Phys. Rev. B 48 11692) as basis functions in the interstitial region instead of ordinary planewaves, as in the usual linearized augmented planewave and augmented planewave plus local orbitals methods. This is shown to lead to a significantly more rapid convergence for open structures as well as a modestly improved convergence for close packed structures.

Effective dose in Albanian direct chest fluoroscopy.

In the absence of reliable supplies of X-ray film, direct fluoroscopy is still extensively used in Albania, with chest radiology a particularly common application. This paper aims to quantify both patient skin dose and the risk-related quantity effective dose for direct fluoroscopy units based in seven different Albanian X-ray departments. A standard Quality Assurance (QA) protocol was used to assess tube potential accuracy, half value layer and X-ray tube output of these units. Three groups of X-ray beam parameters were defined from the QA results, covering the range of chest posteroanterior (PA) fluoroscopy technique factors seen during the study. Organ-equivalent doses were then measured for a nominal PA chest fluoroscopy examination using a Rando anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosimeter chips. Normalised organ dose factors are listed for the three groups of beam conditions simulated. Using these factors, effective dose for the seven systems surveyed was found to be between 0.06 and 0.42 mSv for a 20 s PA chest fluoroscopy examination. Mean effective dose for this group of systems was 0.22 mSv which is a factor of 13 greater than mean effective dose for film/screen PA chest radiography in the UK, whereas entrance surface dose was a factor of 50 greater than the current EU reference level.

The syndrome of Capgras.

Three new cases of the syndrome of Capgras are presented. An unusual variant of the syndrome is recorded. It is contended that the definition of the syndrome should be widened to include impersonators who exhibit slight differences from the prototype, and that ambivalence and projection cannot explain all cases. The syndrome is critically reviewed.

A family with syndactyly type II (synpolydactyly).

Syndactyly Type II is reported in eight members of a family in four generations. Affected individuals show two distinctive patterns of variation in the expression of the gene. Distortion of dermatoglyphic patterns is associated with the severe but not the mild manifestation of the malformation. The diagnostic significance of minimal features of the condition is discussed. Linkage data suggest that loci for Syndactyly II and for blood-group antigens ABO, MNSs, P, Rh and Kell are not closely linked.