Five orders of equatorial reflection were recorded from both relaxed and fully activated intact frog sartorius muscle using synchrotron x-ray radiation. Electron density maps of the myofilament lattice in axial projection were calculated from the integrated intensities by Fourier synthesis, using all possible phase combinations. These maps were evaluated systematically in terms of their compatibility with electron microscopically and biochemically derived properties of the lattice structure and with the minimum wavelength principle. For the relaxed state, one phase combination emerged as most consistent with these constraints: it shows a thick filament with a compact core surrounded by an annular shell of density. The distribution of mass suggests that the S-2 moiety of the myosin molecule is an integral part of the thick-filament backbone and the S-1 moiety makes up the shell and is tilted or slewed around the backbone. For the active state, there are two feasible maps, which differ according to whether or not the activation process is associated with phase inversion in two of the reflections. Both maps represent patterns of redistribution of mass upon activation in which the thick-filament backbone is practically unaffected and there is movement of density from the annular shell towards the thin filaments. In addition to this outward radial flux of density from the thick-filament periphery, the pattern of net mass transfer involves a pronounced azimuthal component in both cases. The total net mass transfer is equivalent to approximately 20% (no phase change) or approximately 40% (with phase change) of the S-1 mass. From the observed systematic increase in peak widths of the higher orders, the size of the crystalline domain in the myofilament lattice in the relaxed sartorius is estimated to be greater than 650 nm and the variations in myofilament lattice spacing among different myofibrils to be about +/- 3%. Furthermore, in the activated state, the equilibrium positions of the myofilaments are no longer well ordered, but are distributed statistically about the lattice points with a standard deviation of approximately 3 nm.

Collins and Edwards (1971, Am. J. Physiol., 221:1130-1133) have shown that a tissue potential can be measured with microelectrodes in glycerinated muscle and that this potential is consistent with a Donnan equilibrium of small ions due to the concentration of net fixed electric charge on the contractile proteins. This approach has been combined with x-ray and light diffraction measurements of the muscle lattice dimensions, and the data are used to determine the thick filament charge and thin filament charge under a variety of different conditions. The thick filament charge is a function of the bathing solution, in particular its pH and ionic composition. These parameters are important in determining the volume of the equilibrium lattice and possibly are involved in the contraction mechanism itself.

An important role of garments is to provide adequate comfort. A study was undertaken of the sensory scores for perceived comfort of wool base layer long sleeve knitted T shirts. This paper, the first in a series, describes and evaluates the wearer trial protocol in which untrained female wearers scored tactile, thermal, and moisture-based sensations during a controlled series of activities in a range of controlled climatic environments. Wearer scores were sufficiently consistent, that significant differences in aggregate scores between garments were detected that reflected changes in the fiber type (wool, cashmere, and cotton) and fiber specifications. Prickle and discomfort scores responded to different factors. The importance of choosing appropriate test conditions when assessing garments for particular end uses was highlighted as both the environment and activity affected wearer's perception of garment performance. A novel test feature was the use of a ‘link’ garment common to separate trials. This, combined with the observed absence of an effect due to garment washing, enabled the testing to be expanded so that 38 garments were successfully compared over 30 months in nine trials. Finally while the first trial used 43 wearers to obtain good estimates of absolute comfort levels, it was demonstrated that a reduction to 25 wearers was adequate for later trials with minimal loss in sensitivity.

A simple subjective test method is described to evaluate the prickliness of fabric samples, and its reproducibility and consistency are assessed. The test is used to evaluate the prickliness of a set of wool knitted samples covering a range of fiber diameters. The finer (19 micron) wool samples are nonprickly, and prickle increases as the mean fiber diameter increases. Reducing fiber/fiber friction with silicones reduces prickle, suggesting that a reduction of fiber/fiber friction is an important mechanism in antiprickle treatments.

No satisfactory technology has emerged for routine rapid measurement of fiber linear density at commercial speed for the cotton industry. This paper introduces the CottonscanTM instrument, a new technology designed to undertake this task. An inter-laboratory trial of the Cottonscan TM system to ascertain the performance of the technology is described. Overall, the 95% confidence limit for a single measurement was estimated to be ±10.4 mtex. Further, spinning trial results have confirmed that unlike the Micronaire value, average fiber linear density obtained from the CottonscanTM correlate well with measured yarn properties. These data indicate that the CottonscanTM instrument can be usefully employed to determine average fiber linear density, an important fiber quality parameter which can be a useful additional tool for the spinner in predicting yarn properties.