Energy versus information based estimations of dissipation using a pair of magnetic colloidal particles.

Using the framework of stochastic thermodynamics, we present an experimental study of a doublet of magnetic colloidal particles that is manipulated by a time-dependent magnetic field. Because of hydrodynamic interactions, each bead experiences a state-dependent friction, which we characterize using a hydrodynamic model. In this work, we compare two estimates of the dissipation in this system: the first one is energy based since it relies on the measured interaction potential, while the second one is information based since it uses only the information content of the trajectories. While the latter only offers a lower bound of the former, we find it to be simple to implement and of general applicability to more complex systems.

An investigation of the RWPE prostate derived family of cell lines using FTIR spectroscopy.

Interest in developing robust, quicker and easier diagnostic tests for cancer has lead to an increased use of Fourier transform infrared (FTIR) spectroscopy to meet that need. In this study we present the use of different experimental modes of infrared spectroscopy to investigate the RWPE human prostate epithelial cell line family which are derived from the same source but differ in their mode of transformation and their mode of invasive phenotype. Importantly, analysis of the infrared spectra obtained using different experimental modes of infrared spectroscopy produces similar results. The RWPE family of cell lines can be separated into groups based upon the method of cell transformation rather than the resulting invasiveness/aggressiveness of the cell line. The study also demonstrates the possibility of using a genetic algorithm as a possible standardised pre-processing step and raises the important question of the usefulness of cell lines to create a biochemical model of prostate cancer progression.

A multifactorial health risk questionnaire.

OBJECTIVE: to assess the relations between cardiovascular risk factors and psychological or socio-economic status. METHODS: We used a self-questionnaire including data upon usual risk factors, anxiety, depression, behavioural pattern, somatic manifestations, life style, incomes and work-related stress. We gathered 955 people, mainly attending an occupational health examination, filling anonymously the same restricted questionnaire (83 questions). RESULTS: Non-working people represented only 4.4 per cent of the study group and included mainly retired people. They differed significantly from wage earners by a higher level of cardiovascular risk and depression, respectively 15.8 (s.d. 11.3) versus 7.8 (6.7) and 5.6 (3.5) versus 3.9 (2.8). These differences can be related to older age of this group. Among working people, 30 per cent felt job-insecurity; they differed significantly from working people by a higher level of anxiety, 8.9 (3.7) versus 7.5 (3.3). There was no difference concerning the absolute cardiovascular risk or the behavioural pattern. A comprehensive self questionnaire is proposed.