Feral Brown rats, Rattus norvegicus, in South Georgia (South Atlantic Ocean)

Brown rats were introduced to the sub-antarctic island of South Georgia probably around 1800. They are now widespread and abundant, particularly on the north coast. The population is divided into discrete units by the rugged topography of the island, particularly the many glaciers. Rats are found mostly in dense stands of coastal tussock grass which provides both shelter and food. They dig burrows in the tussock stools and make nest chambers in the leaf canopy. Tussock, which is rich in carbohydrate, forms the main part of their diet throughout the year. Perimylopid beetles are regularly eaten, and the rats forage on the sea-shore. Carrion is eaten where available and the rats prey on ground-nesting birds. Breeding is probably seasonal, as litters were found only from December to February. The rats have adapted successfully to the rigorous South Georgia climate, but are dependent on tussock grass for their survival. They have made rather little impact on the vegetation. Dove prions, diving petrels and some large petrels are preyed on but breeding colonies of these birds can coexist with rats. The Antarctic pipit rarely if ever nests in rat-infested areas. No management procedures would be possible.     

Identification of the optical isomers of the amino acids in Polysphondylium violaceum acrasin

Using optically specific enzymes on the hydrolysate of glorin, we show the structure of natural glorin to be: N-propionyl-γ-L-glutamyl-L-ornithine-δ-lactam ethyl ester     

Social insects and social amoebae

The evolution of social groupings in insects, especially wasps, is compared to that of social amoebae (cellular slime moulds). They both show a gamut of colony sizes, from solitary forms to complex colonies with a division of labour. The various ideas as to how there might have been an evolution of complexity within insect societies, such as the role of genetic relatedness, the role of mutualism, the origin of sterility, the manipulation and exploitation of some individuals by others within a colony, are discussed, and then applied to social amoebae. The result is both interesting and instructive: despite some differences, there are many striking parallels, which suggests that there are some common denominators in the formation and evolution of a social existence among organisms.     

Acid-catalysed formation of diacetals from butyraldehyde and certain D-glucitol derivatives

Acid-catalysed dibutyiidenation of 1-deoxy-D-glucitol and 3-O-methyl-D-glucitol yields the 2,4:5,6-diacetals as the main, thermodynamically controlled products, and 2-deoxy-D-arabino-hexitol (i.e., 2-deoxy-D-glucitol) yields the 1,3:4,6-diacetal as the main, thermodynamically controlled product.     

Alterations In Metaphase Durations In Cells Derived From Human Tumours

With the use of time-lapse cinemicrography, we previously found that metaphase durations were significantly prolonged in SV40-transformed human fibroblasts when compared to untransformed controls. This was consistent with some earlier reports and suggested that prolonged metaphases could account for high metaphase/prophase ratios and possibly, in part, for increased mitotic indices seen in advanced tumours. However, there are inconsistencies in the literature and no comparable data available from malignant carcinomas. Presented in this paper are data from two cervical dysplasias, two cases of carcinoma in situ, nine malignant carcinomas and several other types of human cells. the results show that mean metaphase durations were prolonged in cells derived from most of the carcinomas but not from the other cell types. On the other hand, cytokinesis appears to progress more rapidly than normal in most of the tumour-derived cells. These and other findings indicate that the changes are a result of some metabolic alteration common to many but not all tumour cells. For reasons presented, we suggest as a working hypothesis that the alterations may be due to changes in calcium regulation, possibly resulting from alterations in mitochondrial metabolism.