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Siberian hamsters (Phodopus sungorus) adapt to seasonal environmental conditions with marked changes in body mass, primarily in the form of adiposity. Winter-like conditions (e.g. short days) are sufficient to decrease body mass by approximately 30% in part via reductions in food intake. The neuroendocrine mechanisms responsible for these changes are not well understood, and homeostatic orexigenic/anorexigenic systems of the hypothalamus provide little explanation. We investigated the potential role of endocannabinoids, which are known modulators of appetite and metabolism, in mediating seasonal changes in energy balance. Specifically, we housed hamsters in long or short days for 0, 3, or 9 weeks and measured endocannabinoid levels in the hypothalamus, brainstem, liver and retroperitoneal white adipose tissue (RWAT). An additional group of males housed in short days for 25 weeks were also compared with long-day controls. Following 9 weeks in short days, levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) were significantly elevated in RWAT and reduced in brainstem, although they returned to long-day levels by week 25 in short-day males that had cycled back to summer-like energy balance. Endocannabinoid levels in these tissues correlated significantly with adiposity and change in body mass. No photoperiodic changes were observed in the hypothalamus or liver; however, sex differences in 2-AG levels were found in the liver (males > females). We further tested the effects of CB(1) receptor signalling on ingestive behaviour. Five daily injections of CB(1) antagonist SR141716 significantly reduced food intake and body mass but not food hoarding. Although the CB(1) agonist arachidonyl-2-chloroethylamide did not appreciably affect either ingestive behaviour, body mass was significantly elevated following 2 days of injections. Taken altogether, these findings demonstrate that endocannabinoid levels vary with sex and photoperiod in a site-specific manner, and that altered signalling at CB(1) receptors affects energy balance in Siberian hamsters.

A novel 'crossed bevel' technique has been used for the investigation of the evolution of the altered layer that forms in a SiGe alloy under 8 keV O 2 + ion bombardment. Auger microscopy (MULSAM instrument) and low-energy ion beam bevelling (500 eV O 2 + ) were used to composition-depth profile a high-energy (8 keV O 2 + ) bevel that contained the complete history of the altered layer. The sample was transferred in vacuo from the bevelling instrument to the Auger microscope. The formation of a Ge-rich layer 15 nm below the altered layer surface, with an associated near-surface Ge depletion, was observed, consistent with previous measurements. The growth of a surface oxygen implant was also seen. The importance of the development of this technique is that it will enable the powerful multispectral chemometric capability of the MULSAM instrument to be applied to altered layer redistribution in the future.

Colorcurve (D65/1964) and Coloroid (C/1931) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the Colorcurve and Coloroid notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples. Colorcurve notations are derived from the OSA-UCS aim points, and Coloroid notations are derived from colorimetric data of the OSA-UCS samples contained in MacAdam's copy of the OSA-UCS colour atlas.

This article presents an evaluation of the deviation of the Colorcurve atlas samples from their designated aim points. Sample deviations are evaluated in terms of hue, chroma, and lightness. In addition, the deviation of the Colorcurve samples from their respective aim points are graphically represented for eighteen lightness levels, Comparison is provided with NCS, DIN, and OSA-UCS atlas sample deviation.

Details of an expanded and improved computer program for the interconversion of colour notations are presented. This article describes the inclusion of the Colorcurve, SCA 2541, and HunterLab systems, expansion of the DIN and RAL implements, extension of the NCS aim point database, improvements to the OSA-UCS and Coloroid conversion algorithms, a direct spectral curve input facility, and the inclusion of CIELAB, CIELUV, HunterLab, CMC[1:1], FMC-1, and FMC-2 colourdifference formulas. © 1992 John Wiley & Sons, Inc.

NCS (C/1931) and DIN (C/1931 and D65/1964) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the NCS and DIN notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples.

This article describes a further investigation into the accuracy of the samples that comprise the NCS colour atlas. Earlier research has demonstrated that the NCS atlas samples are, on average, more inaccurate than the samples that comprise other comparable colour atlases. The present work identifies areas of the NCS colour atlas containing coloured samples that significantly deviate from their intended aim points.

A computer program has been developed that converts between the notations of the Munsell, OSA-UCS, NCS, DIN, and Coloroid colour order systems and the CIE, CIELAB, and CIELUV colour specification systems. The intention of this article is to outline the development of this program and its structure. Particular attention is given to the accuracy of the program and its associated databases.

In 1985 a research program was instigated to determine the feasibility and desirability of developing a computer based colour notation conversion program. Results indicated that the development of such a program covering the Munsel, NCS, DIN, OSA-UCS, Coloroid, CIELAB and CIELUV colour specification systems for use as a research tool was both feasible and desirable. The program was completed early in 1989 and this is the first of a number of articles that uses this program as a research tool. The colour notation conversion program has been used to evaluate the accuracy of the samples which comprise the NCS, DIN and OSA-UCS colour atlases.