Microscopic models for dielectric relaxation in disordered systems

It is shown how the Debye rotational diffusion model of dielectric relaxation of polar molecules (which may be described in microscopic fashion as the diffusion limit of a discrete time random walk on the surface of the unit sphere) may be extended to yield the empirical Havriliak-Negami (HN) equation of anomalous dielectric relaxation from a microscopic model based on a kinetic equation just as in the Debye model. This kinetic equation is obtained by means of a generalization of the noninertial Fokker-Planck equation of conventional Brownian motion (generally known as the Smoluchowski equation) to fractional kinetics governed by the HN relaxation mechanism. For the simple case of noninteracting dipoles it may be solved by Fourier transform techniques to yield the Green function and the complex dielectric susceptibility corresponding to the HN anomalous relaxation mechanism.

Non-linear conductance of disordered quantum wires

The self-consistent electron potential in a current-carrying disordered quantum wire is spatially inhomogeneous due to the formation of resistivity dipoles across scattering centres. In this paper it is argued that these inhomogeneities in the potential result in a suppression of the differential conductance of such a wire at finite applied voltage. A semi-classical argument allows this suppression, quadratic in the voltage, to be related directly to the amount of intrinsic defect scattering in the wire. This result is then tested against numerical calculations.

Mentally disordered offenders and the European Court of Human Rights

This article presents the findings from a study of cases taken to the European Court of Human Rights by mentally disordered offenders. The issues raised include the problems raised by indeterminate sentences, the use of detention for preventive purposes, and debates about treatment. The countries represented are Belgium, Norway, Poland, the Netherlands, Russia and the United Kingdom.

The control and learning of patterns of interlimb coordination: past and present issues in normal and disordered control

The present paper provides a historical note on the evolution of the behavioral study of interlimb coordination and the reasons for its success as a field of investigation in the past decades. Whereas the original foundations for this field of science were laid down back in the seventies, it has steadily grown in the past decades and has attracted the attention of various scientific disciplines. A diversity of topics is currently being addressed and this is also expressed in the present contributions to the special issue. The main theme is centered on the brain basis of interlimb coordination. On the one hand, this pertains to the study of the control and learning of patterns of interlimb coordination in clinical groups. On the other hand, basic neural approaches are being merged together with behavioral approaches to reveal the neural basis of interlimb coordination. (C) 2002 Elsevier Science B.V. All rights reserved.

Factors influencing eating a varied diet in old age

OBJECTIVE:
To investigate the influences of resources and food-related goals on the variety of food choice among older people.
DESIGN:
A questionnaire-based survey in eight European countries: Poland, Portugal, United Kingdom, Germany, Sweden, Denmark, Italy and Spain.
SUBJECTS:
Participants (n 3200) were above 65 years of age and living in their own homes. The samples were quota samples, eight groups of fifty in each country, based on gender, age and living circumstances, reflecting the diversity of each of the national populations based on education, income and urbanization of living environment.
RESULTS:
Hierarchical multiple regression analysis showed that income, health status, access to a car and living arrangement affected the level of dietary variety. The perceived level of different food-related resources impacted the consumption of a varied diet over and above actual resource levels. Food-related goals contributed to variety of food intake that was not accounted for by the amount of material resources possessed or the social and other resources perceived to be possessed.
CONCLUSIONS:
Older people's variety of food intake depended on material resources (e.g. monthly income, access to a car, living arrangement, physical and mental health). However, in addition to these variables, the way older people perceived other resources, such as their level of appetite, their food knowledge, their perception of the distance to the shops, access to high-quality products, having better kitchen facilities, access to good service providers and support from friends and neighbours, all contributed to how varied a diet they ate.