Search

Universities are the main provider of medical student education in the UK; however, its delivery, especially the clinical years but increasingly also the pre-clinical years, often takes place in National Health Service hospitals. Trusts are paid for this privilege through service increment for teaching (SIFT). Developments in clinical governance structures have meant that there is now increased scrutiny and transparency in the funding of clinical services. Lack of similarly robust educational governance structures has led to the risk of educational funds being used to deliver clinical services. This paper examines the current role of SIFT funding and the possible ways forward, using a case study.

Defect Eu^3+ sites in EuVO_4 have been studied with the high-resolution techniques of spectral hole burning and optically detected nuclear quadrupole resonance. A number of EuVO_4 crystals prepared from fluxes with various compositions have been used to show that some point defects are associated with specific chemical impurities but that other defects seem to be present even in the purest crystals. Site-dependent nuclear quadrupole parameters P and η have been determined for both ^7F_0 and ^5D_0 states at two defect sites, and the nuclear Zeeman effect has permitted the local defect site principal axes to be determined.

Optical dephasing measurements are reported for Tm^3+:Y_2Si_2O_7 as a function of temperature and laser excitation intensity. By use of photon echoes, a coherence time of T_2 = 23 μs was measured at 1.24 K for the ^3H_6(1) ? ^3H_4(1) transition at 790.427 nm, corresponding to a homogeneous linewidth of 14 kHz. The relatively broad inhomogeneous linewidth of 100 GHz gives an inhomogeneous-to-homogeneous linewidth ratio of Γ_inh/Γh = 7 × 10^6. This large ratio, a transition wavelength suitable for GaAlAs semiconductor lasers, and the absence of hyperfine structure hole burning make this material a good candidate for time-domain signal processing and transient optically addressed data storage.

MIGRATORY birds and homing pigeons can apparently obtain directional information from the Earth's magnetic field. The effect is difficult to detect, and discussion of the possible process of magnetic field detection by birds seems so far to have foundered on the simple fact that the orientational effect of the Earth's magnetic field on a single electron spin associated with a molecule of animal tissue would be of the order 10−8eV—almost certainly too small to be detectable biologically. Here I direct attention to a process which would overcome this basic problem, and which also seems to provide an explanation of all the main features of published data. It is a mechanism in principle only, however, and is discussed here in no more detail than is necessary to clarify the basic ideas and to provide a basis for further investigation.

DURING recent years there has been an increasing number of reports in the literature of the ability of magnetic fields to affect biological systems. Gerencser and Barnothy1noted differences from control of cultures exposed to 15,000 gauss, while Butler and Dean2found growth inhibition in tissue culture of KB cells exposed to 4,000-gauss magnetic fields. Maclean3, using intense and ‘mild’ magnetic fields of unspecified strengths, reported various effects on tumour-bearing mice, but since only 12 animals were used for the entire investigation and these were divided into 3 groups, the results can have no statistical significance. Negative reports have appeared too, and in the most recent of these Halpern and Greene4reported that the growth rate of HeLa cells cultured in a 1,200-gauss magnetic field was not significantly different from controls. This communication extends this negative finding to much higher magnetic field strengths. Three separate experiments were performed, using HeLa cells cultured in vitro.

The morphology of features on the floor of the Mangala Valles suggests that the channel system was not bank‐full for most of the duration of its formation by water being released from its source, the Mangala Fossa graben. For an estimated typical 50 m water depth, local slopes of sin α= ∼0.002 imply a discharge of ∼1 × 107m3s−1, a water flow speed of ∼9 m s−1, and a subcritical Froude number of ∼0.7–0.8. For a range of published estimates of the volume of material eroded from the channel system this implies a duration of ∼17 days if the sediment carrying capacity of the ∼15,000 km3of water involved had been 40% by volume. If the sediment load had been 20% by volume, the duration would have been ∼46 days and the water volume required would have been ∼40,000 km3. Implied bed erosion rates lie in the range ∼1 to ∼12 m/day. If the system had been bank‐full during the early stages of channel development the discharge could have been up to ∼108m3s−1, with flow speeds of ∼15 m s−1and a subcritical Froude number of ∼0.4–0.5.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.