Members of the New World primate genera Callithrix and Cebuella have specialisations for eating plant exudates. Exudates are also an important component of the diets of many other callitrichid species in the wild, especially at times of nutritional stress. Gum arabic is fed daily to all marmosets and to some tamarins in Jersey Zoo's collection. This study investigated species differences in liking for gum and the effects of the concentration of gum solutions on palatability. As predicted from field data, Callithrix species consumed more gum than other species; Saguinus also showed quite a strong liking for gum. In parallel with data from the wild, lion tamarins (Leontopithecus spp.) consumed the least, and Callimico also took relatively little. The two marmoset species tended to like stronger solutions of gum more than weak solutions and, therefore, the provision of smaller amounts of stronger concentrations is likely to be the most cost-effective way of incorporating gum into the diet. Providing gum to callitrichids on a regular basis can have significant welfare benefits.

The Guide to the expression of uncertainty in measurement (GUM) requires, “that the results of a measurement have been corrected for all recognised significant systematic effects and that every effort has been made to identify such effects”, before the issue of evaluating their uncertainty is tackled. In addition, the GUM also requires that a model is used, expressing the functional dependence of the measurand on identified input quantities. The paper discusses the inter-relations between the so-defined two sets of influence quantities and proposes to unify their treatment.

A common measurement model for a gas operated piston-cylinder based pressure standardeffective area is the well known integral equation formulation originally developed byDadson of the NPL. However a problem with directly applying this exact mathematical modelis that it cannot be easily cast into a functional form suitable for application of theGuide to the expression of Uncertainty in Measurement (GUM) which is reliant on theconcept of sensitivity coefficients without various simplifications. In this paper, weexamine the standard approximations that are currently necessary in order to directlyapply the GUM for a pressure standard effective area uncertainty determination. We alsocompare and contrast this to the exact effective area uncertainty results obtained throughthe direct application of the Monte Carlo Method (MCM) which has recently been publishedas Supplement 1 to the GUM. Based on these investigations we also draw some preliminaryconclusions on the relative merits on the extent to which the shape of the piston andcylinder radii and whose uncertainties may vary along the engagement length of thepiston-cylinder may be modeled and incorporated into a piston-cylinder’s effective areauncertainty calculation.

The effect of high- (hePE) and low- (lePE) esterification pectin and high- (hvGG) and low-(lvGG) viscosity guar gum on plasma, hepatic and biliary lipids and on prevention of cholesterol gallstones was investigated in male golden Syrian hamsters (Mesocricetus auratus). Hamsters were fed on cholesterol-rich (4g/kg), gallstone-inducing diets for 6 weeks. The diets were supplemented with 80g hePE, lePE, hvGG or lvGG/kg or 80g additional cellulose/kg. No significant differences in plasma total cholesterol and triacylglycerol concentrations between hvGG and lvGG and the gallstone-inducing or cellulose-enriched diets were observed. The hePE diet produced a 16% (non-significant) reduction in total plasma cholesterol but significantly decreased the plasma triacylglycerol level by 45%. The lePE diet caused only minor changes in plasma lipids. Hepatic cholesterol concentrations were significantly higher in hamsters fed on hvGG, lvGG, hePE or lePE primarily due to the accumulation of esterified cholesterol. Supersaturated bile samples, with lithogenic indices ranging from 1.6 to 2.0, were determined with all diets. The hePE and lePE diets slightly altered the bile acid profile by increasing glycocholic acid and decreasing taurochenodeoxycholic acid concentrations resulting in a higher cholic: chenodeoxycholic acid ratio. Cholesterol gallstone formation was not substantially inhibited by the two varieties of pectin and guar gum. The hvGG, lvGG, hePE and lePE diets did not alter faecal weight and caused only minor increases in faecal bile acid excretion. In general, the present findings demonstrate that dietary pectins and guar gums had only minor effects on cholesterol metabolism and did not prevent cholesterol gallstone formation in this hamster model. Possible explanations for this lack of a distinct response to pectin and guar gum are discussed.