Quantitative analysis of single muscle fibre action potentials recorded at known distances

In vivo records of single fibre action potentials (SFAPs) have always been obtained at unknown distance from the active muscle fibre.\ud \ud A new experimental method has been developed enabling the derivation of the recording distance in animal experiments. A single fibre is stimulated with an intracellular micropipette electrode. The same electrode is used thereafter for labelling with an auto-fluorescent dye, Lucifer Yellow. In this method there is no use of chemical fixation. The tissue structure is kept as well as possible. In cross-sections the fluorescent fibre is seen and its position is quantitized with respect to the tip of one or more recording wire electrodes.\ud \ud Morphometric data, such as the recording distance and the fibre cross-sectional area, are used for the interpretation of parameters of the SFAPs (peak-peak amplitude, time between the first positive and negative peaks). The present results show that within 300 μm recording distance is not as dominant for the SFAP shape as expected.\ud \ud The method offers also a direct check of the relation between the muscle fibre; diameter and the conduction velocity of the action potential. In the present small set of data there is no simple linear relationship

Organic layers on silicon result in a unique hybrid fet

A Field-Effect Transistor (FET) is presented that combines the conventional lay-out of the silicon substrate (channel and source and drain connections) with a Si-C linked organic gate insulator contacted via an organic, conducting polymer. It is shown that this hybrid device combines the excellent electrical behavior of the silicon substrate and the ease of use and good properties of organic insulators and contacting materials.\ud Keywords: organic monolayer, FET, conducting polyme

New Pseudo-Phase Structure for α\alpha-Pu

In this paper we propose a new pseudo-phase crystal structure, based on an orthorhombic distortion of the diamond structure, for the ground-state $\alpha$-phase of plutonium. Electronic-structure calculations in the generalized-gradient approximation give approximately the same total energy for the two structures. Interestingly, our new pseudo-phase structure is the same as the Pu $\gamma$-phase structure except with very different b/a and c/a ratios. We show how the contraction relative to the $\gamma$ phase, principally in the $z$ direction, leads to an $\alpha$-like structure in the [0,1,1] plane. This is an important link between two complex structures of plutonium and opens new possibilities for exploring the very rich phase diagram of Pu through theoretical calculations

Perceived fit in activity-based work environments and its impact on satisfaction and performance

Activity-based work environments are widely adopted; however, research shows mixed findings regarding privacy issues, satisfaction with the work environment, and task performance. To further our understanding, two complementary studies drawing on Person-Environment fit theory were conducted: (1) A field study using experience sampling, and (2) A lab study in a virtual reality studio. The results from both studies confirm that perceived fit is a function of activity, work setting, and personal need for privacy, with indirect effects on satisfaction with the work environment (Studies 1 and 2) and task performance (Study 2). Across both studies, a misfit was perceived particularly among workers high in personal need for privacy when performing high-complexity tasks in an open office work setting. Hence, we recommend that organizations facilitate and stimulate their workers to create better fits between activities, work settings, and personal characteristics

An analytical stability theory for Faraday waves and the observation of the harmonic surface response

We present an analytical stability theory for the onset of the Faraday instability, applying over a wide frequency range between shallow water gravity and deep water capillary waves. For sufficiently thin fluid layers the surface is predicted to occur in harmonic rather than subharmonic resonance with the forcing. An experimental confirmation of this result is given. PACS: 47.20.Ma, 47.20.Gv, 47.15.CbComment: 10 pages (LaTeX-file), 3 figures (Postscript) Submitted for publicatio