Spin dynamics of the ferromagnetic superconductor UGe2_{2}

Inelastic neutron scattering was used to study the low energy magnetic excitations of the ferromagnetic superconductor UGe$_{2}$. The ferromagnetic fluctuations are of Ising nature with a non-conserved magnetization and have an intermediate behavior between localized and itinerant magnetism.Comment: European Conference on Neutron Scattering, Montpellier 2003 (to appear in Physica B

What is the "Q" for?

This paper is based on the Law Teacher of the Year keynote speech delivered at the Association of Law Teachers’ Annual Conference in April 2011 in Cardiff, Wales. Some refinement of the ideas expressed then took place and a further presentation formed my inaugural Readership seminar at Nottingham Law School in June 2011. The essence of the speeches was to seek to address the fitness for purpose of the Qualifying Law Degree (QLD) in the context of contemporary legal education, but more recently has focused the need for the requirements of the QLD better to reflect and promote what is best about law and legal education. Thus, rather than skills being incidental to academic legal study, I suggest that certain discipline-specific cognitive professional skills should replace the foundation subjects in the QLD. This paper concludes with some sample programmes designed to meet legal intellectual professional skills that meet the needs of the law student in the early 21st century whilst respecting institutional autonomy in legal curriculum design

Instabilities in the transient response of muscle

We investigate the isometric transient response of muscle using a quantitative stochastic model of the actomyosin cycle based on the swinging lever-arm hypothesis. We first consider a single pair of filaments, and show that when values of parameters such as the lever-arm displacement and the crossbridge elasticity are chosen to provide effective energy transduction, the T2 curve (the tension recovered immediately after a step displacement) displays a region of negative slope. If filament compliance and the discrete nature of the binding sites are taken into account, the negative slope is diminished, but not eliminated. This implies that there is an instability in the dynamics of individual half-sarcomeres. However, when the symmetric nature of whole sarcomeres is taken into account, filament rearrangement becomes important during the transient: as tension is recovered, some half-sarcomeres lengthen while others shorten. This leads to a flat T2 curve, as observed experimentally. In addition, we investigate the isotonic transient response and show that for a range of parameter values the model displays damped oscillations, as recently observed in experiments on single muscle fibers. We conclude that it is essential to consider the collective dynamics of many sarcomeres, rather than the dynamics of a single pair of filaments, when interpreting the transient response of muscle.Comment: 11 pages, 11 figures, Submitted to Biophysical Journa

Heat Capacity of the Pressure-induced Superconductivity in Itinerant Ferromagnet UGe2_2

Recently co-existence of the ferromagnetism and superconductivity was reported in the high-pressure region (1.0-1.6 GPa) in UGe$_2$. We performed the heat capacity measurement on UGe$_2$ under high pressure. At 1.13 GPa, we found a peak corresponding to the superconducting transition. The superconducting temperature $T_{SC}$ and ${\it\Delta} C/(\gamma T_{SC})$ are 0.6 K and 0.25, respectively. The superconducting transition was also confirmed by the appearance of the Meissner effect in the {\it ac} susceptibility. From these results, we confirm a bulk nature of the superconductivity in UGe$_2$. The value of $C/T$ ($\sim$ 95 mJ/moleK$^2$) just above $T_{SC}$ at 1.15 GPa is as much as 3 times larger than that at ambient pressure, which indicates a large mass enhancement of quasiparticles under high pressure.Comment: submitted to the International Conference on Strongly Correlated Electron Systems 200