Sporadic salmonellosis has been reported in mature lactating dairy cattle in the southwestern United States and is an intriguing problem in that Salmonella can be cultured from faecal samples of these cattle throughout the year. However, it is pathogenic only during late summer/early autumn and in certain years. We sampled apparently healthy (n=10) and diarrhoeic (n=10) cattle during an outbreak on a 2000 head dairy in 2003. The following year, monthly faecal (from the same 30 head), total mixed ration, water, and pen soil samples were collected for Salmonella culture. No serogroup, serotype, genetic, or antimicrobial susceptibility differences were observed in comparison of isolates from healthy and sick cattle. During year 2 of the study, Salmonella was routinely cultured (although highly variable from month to month) from the cattle and the environment, although no outbreak of salmonellosis was observed.

The primary cilium is a ubiquitous cytoplasmic organelle of unknown function. Ultrastructural evidence of primary cilia in chondrocytes, and their colocalisation with the Golgi apparatus, has led to speculation that these structures are functionally linked. To investigate the relationship between these organelles, we examined the molecular anatomy of the microtubular cytoskeleton in the chondrocytes of chick embryo sterna. Thick cryosections were immunolabelled with antibodies directed against acetylated α-tubulin (C3B9), detyrosinated α-tubulin (ID5) and total α-tubulin (TAT), and imaged at high magnification using confocal laser scanning microscopy. Transmission electron microscopy confirmed the ultrastructure of the chondrocyte primary cilium and its structural relationship to the Golgi apparatus. Detyrosinated and acetylated α-tubulins were concentrated in the centrioles, centrosome and microtubule organising centre adjacent to the nucleus, with total α-tubulin distributed throughout the cytoplasm. ID5 stained the primary cilium at an incidence of 1 per cell, its colocalisation with C3B9 identifying the primary cilium as one of the most stable features of the microtubular cytoskeleton. Primary cilia varied from 1 to 4 μm in length, and 3 patterns of projection into the extracellular matrix were identified; (1) full extension and matrix contact, with minor undulations along the length; (2) partial extension and matrix contact, with a range of bending deflections; (3) cilium reclined against the cell surface with minimal matrix contact. Ultrastructural studies identified direct connections between extracellular collagen fibres and the proteins which decorate ciliary microtubules, suggesting a matrix–cilium–Golgi continuum in hyaline chondrocytes. These results strengthen the hypothesis that the primary cilium acts as a ‘cellular cybernetic probe' capable of transducing environmental information from the extracellular matrix, communicating this information to the centrosome, and regulating the exocytosis of Golgi-derived secretory vesicles.

My main concern in this paper will be with questions of national identity, multiculturalism, and aboriginal rights as they have emerged in Australia, especially over the past twenty or so years. The issues are not, of course, unique to Australia: similar questions have arisen in other places, including Canada, New Zealand, and the United States. However, each place has specific problems, and while I hope that much of what I say has relevance to these countries, I will not try to establish this here.

The paper falls into two parts. In the first, I argue for certain limits on the practice of multiculturalism. The basis of this argument is a concern for national identity – especially for what I will call ‘national sovereignty.’ This is a familiar conservative position; however, I hope to show that it is one which liberals and those on the left should take seriously. In the second part of the paper, I distinguish the issue of Aboriginal (or indigenous) rights from multiculturalism, and try to establish that the basis of these rights is a principle very similar to the notion of national sovereignty.