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Several letters to the editor are presented in response to various reports published in previous issues of the journal including monogamy, making disappointing deals in property purchase, and junk music in public building.

A series of high surface area nanocrystalline copper manganese oxide catalysts have been prepared by supercritical anti-solvent (SAS) precipitation using CO2and tested for the ambient temperature oxidation of CO. The catalysts were prepared by precipitation from an ethanol/metal acetate solution and the addition of small quantities of water was found to result in a mixed acetate precursor with surface areas >200 m2g−1, considerably higher than those prepared by conventional precipitation methods. The surface area of the final calcined mixed oxide was found to be dependent upon the initial water concentration. XRD and FT-IR analysis indicated that the addition of water promoted the formation of carbonate species in the amorphous acetate precursor, with high resolution TEM and STEM showing the material to consist of spherical agglomerations of fibrous strings of ca.30 nm length. This is in contrast to the material prepared in the absence of water, using the same SAS methodology, which typically yields quasi-spherical particles of 100 nm size.

The aim of this study was to characterize foot-and-mouth disease (FMD) viruses collected between 2004 and 2008 from Sudan, a country where FMD is endemic. Using virus isolation and antigen ELISA, three FMD virus serotypes (O, A and SAT2) were detected in 24 samples that were submitted to the FAO World Reference Laboratory for FMD. Pan-serotypic real-time RT-PCR assays targeting the 5' untranslated region (5'UTR) and 3D genes of FMD virus were also used to contribute to the laboratory diagnosis of these cases. The lack of concordant results between the real-time RT-PCR assays for three serotype O viruses was attributed to four nucleotide mismatches in the 5'UTR PCR primer and probe sites (three substitutions for the sense-primer and one in the TaqMan®probe region). Taken together, the laboratory results showed that recent FMD outbreaks that occurred during 2008 in northern and central Sudan were caused by serotypes O and SAT2, while serotype A was last detected in 2006. Phylogenetic analyses of VP1 sequences from these viruses were used to determine the relationships with 23 older viruses from Sudan and other viruses from West and East Africa. For serotype O, closest genetic identities were between concurrent and historical Sudanese isolates, indicating that within-country circulation is an important mechanism by which FMD is maintained year-on-year in Sudan. A similar pattern was also evident for serotype A and SAT2 viruses; however, these lineages also contained recent representative FMD viral isolates from other countries in the region suggesting that long-distance animal movement can also contribute to FMD dispersal across sub-Saharan Africa. These findings provide the first molecular description of FMD viruses that are circulating in Sudan, and highlight that further sampling of representative viruses from the region is required before the complex epidemiology of FMD in sub-Saharan Africa can be fully understood.

In 2007, serological evidence for foot-and-mouth disease (FMD) infection was found as a result of differential diagnostic testing of Cypriot sheep suspected to be infected with bluetongue or contagious ecthyma. Seropositive sheep and goats were subsequently uncovered on ten geographically clustered flocks, while cattle and pigs in neighbouring herds were all seronegative. These antibodies were specific for serotype-O FMD virus, reacting with both structural and non-structural (NS) FMD viral proteins. However, no FMD virus could be recovered from the seropositive flocks. FMD had not been recorded in Cyprus since 1964 and there has been no vaccination programme since 1984. Since all the seropositive animals were at least 3?years old and home-bred, it was concluded that infection had occurred approximately 3?years previously had passed un-noticed and died out spontaneously. It therefore appears that antibodies to FMD virus NS proteins can still be detected around 3?years after infection of small ruminants, but that virus carriers cannot be detected at this time. This unusual situation of finding evidence of historical infection in a FMD-free country caused considerable disruption and alarm and posed questions about the definition of what constitutes a FMD outbreak.

This report describes the characterization of a new genotype of foot-and-mouth disease virus (FMDV) type A responsible for recent FMD outbreaks in the Middle East. Initially identified in samples collected in 2003 from Iran, during 2005 and 2006 this FMDV lineage (proposed to be named A-Iran-05) spread into Saudi Arabia and Jordan and then further west into Turkey reaching European Thrace in January 2007. Most recently A-Iran-05 has been found in Bahrain. To the east of Iran, it has been recognized in Afghanistan (2004-07) and Pakistan (2006-07). Throughout the region, this lineage is now the predominant genotype of FMDV serotype A sampled, and has appeared to have replaced the A-Iran-96 and A-Iran-99 strains which were previously encountered. In August 2007, a new A-Iran-05 sub-lineage (which we have called A-Iran-05ARD-07) was identified in Ardahan, Turkey, close to the border with Georgia. This new sub-lineage appeared to predominate in Turkey in 2008, but has, so far, not been identified in any other country. Vaccine matching tests revealed that the A-Iran-05 viruses are antigenically different to A-Iran-96 and more like A22. These findings emphasize the importance of undertaking continued surveillance in the Middle East and Central Asia in order to detect and monitor the emergence and spread of new FMDV strains.

A novel method for the preparation of vanadyl hydrogen phosphite hydrates is described. The reaction of V2O5, H3PO3, and 1-propanol in the absence of water at 150 °C led to the formation of VOHPO3·1.5H2O with high surface area (ca. 50 m²/g), whereas in the presence of water VOHPO3·H2O was the unique product. The materials were characterized using a combination of techniques including elemental analysis, thermogravimetric analysis, powder X-ray diffraction, laser Raman spectroscopy, and infrared spectroscopy. On heating the sample in flowing nitrogen at 750 °C, it was found that the vanadyl(IV) hydrogen phosphite(III) hydrates transformed into vanadium(III) phosphate(V), VPO4, via an internal oxidation−reduction process between V(IV) and P(III), wherein V(IV) was reduced to V(III) and P(III) was oxidized to P(V). Whereas, heating the vanadyl hydrogen phosphite hydrates in flowing hydrogen can inhibit the phase transformation from vanadyl hydrogen phosphite to VPO4. The catalytic performance for the selective oxidation of n-butane to maleic anhydride using the final catalysts prepared by in situ activation under the reaction conditions was contrasted. It was found that the catalyst derived from the VOHPO3·H2O precursor shows a higher intrinsic activity for the production of maleic anhydride than that derived from VOHPO3·1.5H2O.

The microstructure of an iron oxide based high temperature water-gas shift (WGS) catalyst has been studied by X-ray diffraction (XRD), high resolution electron microscopy (HREM), high spatial resolution energy dispersive X-ray analysis (STEM-EDX) and X-ray photoelectron spectroscopy (XPS). The iron oxide contains a chromia additive that structurally stabilises the catalyst. Chemical microanalysis indicates that the chromia forms a solid solution within the magnetite Fe₃O₄ lattice and that no discrete chromia phases are formed. The level of Cr dissolution varies greatly at the intergranular level. XPS and STEM-EDX studies suggest that the activated catalyst is surface enriched in chromia. On the basis of these results a model for the stabilising effect is proposed in which the enriched surface ‘shell’ encapsulates each catalyst grain and, being more thermodynamically stable than the iron-rich core, reduces ion diffusion and sintering effects. A Cu dopant is often added to the Fe₃O₄/Cr₂O₃ catalyst to promote its activity. Chemical microanalysis shows that this dopant also exists in solid solution. Furthermore, STEM-EDX and XPS analyses indicate that the catalyst grains also exhibit a strong surface enrichment in the Cu species. Analysis of aged ex-reactor specimens suggest that deactivation occurs as a result of eventual sintering, with a substantial increase in grain-size relative to the fresh catalyst. The Cu dopant is also demonstrated to have a propensity to segregate as CuO on the surface of the catalyst grains in aged specimens.

We present gradient corrected density function theory calculations on the adsorption and thermally activated diffusion pathways of hydrogen on the {111} surfaces of Ni, Pd, and Pt. We find that the variation of the adsorption energy as a function of adsorption site shows considerable differences between the three metals. For Ni and Pd, the adsorption energies vary as a function of hydrogen coordination with the 3-fold hollow sites the most stable and the 1-fold atop site considerably less stable. On Pt the adsorption energies for all the sites are similar indicating that diffusion across the surface will be faster on Pt than on Ni or Pd. The activation energies for diffusion have been calculated with that for Pt (2−3 kJ mol^-1) considerably smaller than for Ni or Pd (13 kJ mol^-1). The calculated adsorption and activation energies are in good agreement with experimental investigations of the structure, energetics, and diffusion properties.

We have performed density functional theory calculations on the adsorption of ethene onto the {111} surface of platinum. We find that the adsorption energy is sensitive to the k-point sampling used, with low k-point sampling giving rise to overestimated adsorption energies, close to the values predicted from small cluster calculations. Six adsorption modes (bridge, fcc hollow, hcp hollow, atop bridge, atop hollow, and cross bridge) were investigated on a rigid Pt {111} surface. The most stable site was the bridge site (di-σ type adsorption) with an adsorption energy of 108.7 kJ mol^-1 and C−C bond length of to 1.483 Å, which is significantly longer than the calculated gas-phase ethene bond length of 1.334 Å. The recently proposed fcc hollow site adsorption was found to be significantly less stable (63.6 kJ mol^-1) although slightly more favorable than the atop (π adsorbed) modes. The effect of surface relaxation on the adsorption energy and structure was investigated by allowing the entire Pt {111} slab to relax, giving rise to large changes in the positions of the coordinating Pt atoms. The bridge site shows displacements of 0.235 Å out of the surface for the two Pt atoms directly coordinated to the ethene C atoms with an increase in the adsorption energy of 18.6 kJ mol^-1 compared to the rigid surface case from 108.7 to 127.3 kJ mol^-1. The effect of Pt relaxation was greatest on the atop sites with the single Pt atoms coordinated to the ethene moving 0.356 Å out of the surface for both adsorption modes. This was accompanied by an increase of the adsorption energy of 26 kJ mol^-1 with the atop bridge (85.8 kJ mol^-1) slightly more stable than the atop hollow (84.8 kJ mol^-1). The hollow sites were affected by surface relaxation so much so that the energetic order of the atop and hollow sites is reversed when surface relaxation is included, indicating that the latter are unlikely to be observed. We conclude that the large effect of both the k-point sampling and surface relaxation on the adsorption energy is based on a compromise between the extended electronic states and localized bonding. The effect of periodic calculations with converged k-point sampling is to accurately treat the repulsion between the extended electronic states and the molecule. The effect of surface relaxation is to allow the atoms involved in localized bonding to move out of the surface, reducing the repulsion due to the extended electronic states and so increasing the adsorption energy. As such, the use of cluster calculations, especially for molecules with weak interactions with the surface, would be expected to result in significant overestimation of the adsorption energies.

Interactive learning by computer is adopting an increasingly important role in medical education in many countries. Traditional methods of medical education can be enhanced and augmented by the addition of self-directed computer-assisted learning. While it is desirable for specialists in a medical content to create their own computer-based teaching programmes, authoring with hypertext and multimedia can pose significant difficulties for non-computer programmes. This paper describes how the authors approached the design and creation of a medical education programme on sexually transmitted diseases using StackMaker, a new hypermedia authoring environment.

Acetylene hydrochlorination catalysts consisting of activated carbon impregnated with a solution of HAuCl4·xH2O in aqua regia have been studied by197Au Mössbauer spectroscopy. The relative amounts of AuCl4−, of Au(0), and of an Au(J) species formed under certain process conditions were determined quantitatively. Deactivation of the catalyst at low and high temperatures was shown to be due to different mechanisms, and the reactivation of the catalyst by Cl2gas was studied.

The origination, development and application of a hypermedia system for use in the life sciences is described. Implemented in the Apple Macintosh Hypercard environment, the project has been designed to make use of commercially produced laser discs as visual archives and has included the production of authoring and navigational tools. We report here on our experience in authoring stacks for undergraduate teaching, monitoring of student use and assessment of effectiveness as a self-teaching resource. Future developments and applications within the biomedical sciences are discussed.