Just When You Thought the Euthanasia Debate Had Died

The death by assisted suicide in Switzerland of Australian Dr. John Elliott, in early 2007 has highlighted the inadequacy of the law pertaining to medical decisions at end-of-life, both from a legal as well as ethical perspective. Despite being illegal in most jurisdictions around the world, physician-assisted death is a reality, in part because of the flexibility, inconsistent application and, at times, invisibility, of laws surrounding it. The appropriate response to this should be greater transparency by a reform of the law.     

Conformational changes in sensory rhodopsin I: similarities and differences with bacteriorhodopsin, halorhodopsin, and rhodopsin

FTIR difference spectra have been obtained for the sR587----S373 phototransition of sensory rhodopsin I (sR-I), a signal-transducing protein of Halobacterium halobium. The vibrational modes of the sR587 chromophore have frequencies close to those of the bacteriorhodopsin bR568 chromophore, confirming that the two chromophores have very similar structures and environments. However, the sR-I Schiff base C = N stretch frequency is downshifted relative to bR, consistent with weaker hydrogen bonding with its counterion(s). The carboxyl (COOH) stretch modes of sR-I and halorhodopsin (hR) are at the same frequencies. On the basis of sequence homologies, these bands can be assigned to Asp-106 in helix D and/or Asp-201 in helix G. In contrast, no band was found that could be assigned to the protonation of Asp-76. In bR, the homologous residue Asp-85 serves as the acceptor group for the Schiff base proton. Bands appear in the amide I and II regions at similar frequencies in sR-I, hR, and bR, indicating that despite their different functions they all undergo closely related structural changes. Bands are also detected in the C-H stretch region, possibly due to alterations in the membrane lipids. Similar spectral features are also observed in the lipids of rhodopsin-containing photoreceptor membrane upon light activation.     

Convergence of the age structure: Applications of the projective metric

This paper states necessary and sufficient conditions for the convergence of the age structure (in a discrete time, one-sex model of population growth); it also contains a new and simple proof of the weak ergodic theorem of stable population theory. The main tool used to attain these results is Hilbert's notion of the projective metric. This metric provides a way of defining the distance between positive vectors in $\text{R}$ⁿ which has two important features: First, the distance between any two positive vectors depends only on the rays on which the vectors lie; and, second, positive matrices act as contractions in this metric.     

Mapping of calpastatin and three microsatellites to porcine chromosome 2q2·1-q2·4

Three polymorphisms were identified in a 1·6-kb fragment of the porcine calpastatin (CAST) gene and these polymorphisms were used for genetic linkage mapping. Linkage analysis revealed significant linkage of CAST to five microsatellites previously mapped to porcine chromosome 2; these microsatellites were S0010, S0226, Sw14, Sw395 and Sw776. A somatic cell hybrid panel was used to determine the chromosomal localization of CAST and the microsatellites S0091, S0226 and Sw395. All of these were localized to the region 2q2·1–q2·4.