Towards a unified description of the AMOB2O5 (A=K, Rb, Cs, Tl; M=Nb, Ta) family of compounds.

Single-crystal X-ray diffraction data (Mo Kalpha radiation) are used to re-refine the structure of RbNbOB2O5, rubidium niobium oxo pyroborate. The structure is refined as an incommensurate modulated structure with superspace group symmetry Pmn2(1)(0,0.4,0)s and lattice parameters a = 7.406 (2), b = 3.939 (2) and c = 9.475 (2) A. Refinement on 3242 unique reflections converged to R = 0.031, while a previous conventional superstructure refinement led to R = 0.090. This lowering of the R factor goes hand-in-hand with a substantial reduction in the number of refined parameters. The refinement strongly suggests that the structure is effectively incommensurately modulated, despite an apparently rational magnitude of the primary modulation wave-vector and overlap of satellite reflections.

The response of two contrasting limestone grasslands to simulated climate change.

Two different UK limestone grasslands were exposed to simulated climate change with the use of nonintrusive techniques to manipulate local climate over 5 years. Resistance to climate change, defined as the ability of a community to maintain its composition and biomass in response to environmental stress, could be explained by reference to the functional composition and successional status of the grasslands. The more fertile, early-successional grassland was much more responsive to climate change. Resistance could not be explained by the particular climates experienced by the two grasslands. Productive, disturbed landscapes created by modern human activity may prove more vulnerable to climate change than older, traditional landscapes.

Involuntary disclosure of private medical records to the defence in criminal proceedings.

This article concerns the law and procedure governing the production and disclosure to an accused of medical and therapeutic records in the hands of third parties, not part of the Crown's case against the accused. Following a brief analysis of the medico-legal issues involved, this article examines recent statutory changes regarding involuntary disclosure to an accused by third parties of private records in their possession.