Inheritance of molecular markers and sex in the Australian freshwater crayfish, Cherax destructor Clark

Inheritance of three kinds of molecular genetic markers (mtDNA, random-amplified polymorphic DNAs (RAPDs) and allozymes) and sex were investigated in crossbreeding experiments between three populations of the Australian freshwater crayfish Cherax destructor. Crossbreeding did not disrupt the ively maternally inherited, and allozyme and RAPD markers were transmitted following expected Mendelian principles for co-dominant and dominant traits respectively. Unlike these three markers, sex ratios were found to be distorted by crossbreeding in some families. Two crossbred families produced only females. The implications of these findings for freshwater crayfish population genetics, taxonomy and aquaculture are discussed.

The 'Australian settlement' and Australian political thought

Arguments for reshaping political agendas invariably begin from an appraisal of past errors and achievements. Paul Kelly's notion of the 'Australian Settlement' attempts such a task. Kelly identifies a particular ideological and institutional tradition in Australian politics that dominated much of the twentieth century and that is now deemed to have broken down. This article accepts that the notion of a Settlement provides certain insights into the evolution of Australian political thought. Nonetheless, the paper takes issue with the specific content of Kelly's version of the 'Australian Settlement' and indicates how it may be reformulated. It argues that, to the extent that we can speak of a 'Settlement' in Australia, it was one reached on a wider range of key conflicts or cleavages than those to which Kelly refers.

Nitric oxide control of the dorsal aorta and the intestinal vein of the Australian short-finned eel Anguilla australis

This study investigated the mechanisms by which nitric oxide (NO) regulates the dorsal aorta and the intestinal vein of the Australian short-finned eel Anguilla australis. NADPH diaphorase histochemistry and immunohistochemistry using a mammalian endothelial nitric oxide synthase (NOS) antibody could not demonstrate NOS in the endothelium of either blood vessel; however, NOS could be readily demonstrated in the endothelium of the rat aorta that was used as a control. Both blood vessels contained NADPH diaphorase positive nerve fibres and nerve bundles, and immunohistochemistry using a neural NOS antibody showed a similar distribution of neural NOS immunoreactivity in the perivascular nerves. In vitro organ bath physiology showed that a NO/soluble guanylyl cyclase (GC) system is present in the dorsal aorta and the intestinal vein, since the soluble GC inhibitor oxadiazole quinoxalin^-1 (ODQ; 10^–5 mol l^–1) completely abolished the vasodilatory effect of the NO donor, sodium nitroprusside (SNP; 10^–4 mol l^–1). In addition, nicotine (3x10^–4 mol l^–1) mediated a vasodilation that was not affected by removal of the endothelium. The nicotine-mediated dilation was blocked by the NOS inhibitor, Nω-nitro-arginine (L-NNA; 10^–4 mol l^–1), and ODQ (10^–5 mol l^–1). More specifically, the neural NOS inhibitor, Nω-propyl-L-arginine (10^–5 mol l^–1), significantly decreased the dilation induced by nicotine (3x10^–4 mol l^–1). Furthermore, indomethacin (10^–5 mol l^–1) did not affect the nicotine-mediated dilation, suggesting that prostaglandins are not involved in the response. Finally, the calcium ionophore A23187 (3x10^–6 mol l^–1) caused an endothelium-dependent dilation that was abolished in the presence of indomethacin. We propose the absence of an endothelial NO system in eel vasculature and suggest that neurally derived NO contributes to the maintenance of vascular tone in this species. In addition, we suggest that prostaglandins may act as endothelially derived relaxing factors in A. australis.

The eradication of compulsory retirement and age discrimination in the Australian workplace : A cause for celebration and concern

Earlier this year the Age Discrimination Act 2004 was passed by the Commonwealth government. This paper provides an overview of the Age Discrimination Act 2004 and critically examines whether it is likely to be successful in eradicating compulsory retirement and age discrimination within the workforce. Empirical studies suggesting that law reform alone is insufficient to eliminate ageist employer behaviour are discussed as is the need for public awareness campaigns. Given that compliance with the law is closely linked with normative belief, this paper also considers whether a moral duty to refrain from age discrimination can be grounded within the natural law ethic.

Control of the Australian life insurance industry: an example of regulatory externalities within the Australian financial sector 1870-1945

The regulatory environment in which the Australian life insurance industry operates has its antecedents in two major periods of legislative intervention. The first established the principle of ‘freedom with disclosure’ in the 1870s, which has since formed the basis of the regulatory approach. In the 1940s, the second refined the concept in the context of a general recognition of an interventionist approach to financial markets. It is suggested that regulation of the life insurance market in Australia came about not in response to problems associated with market failure but in reaction to external influences not directly related to conditions in the Australian life insurance industry. This was impacted not only on the timing of intervention but on the approach taken as well.

Is the treatment of economic loss by the Australian courts in torts cases anomalous?

The well developed economic theory of tort liability has never been able to comfortably accommodate negligence cases causing pure economic loss as opposed to physical damage or injury. In fact, contrary to received opinion, Australian Courts at least, are increasingly allocating pure economic losses to achieve predominantly an efficiency objective, with corrective justice notions relegated into the background. Consequently, it is difficult to classify these cases as anomalous in the sense of falling outside the efficiency paradigm.

The protection of political communication under the Australian constitution

Compatibility of a law with implied freedom of political communication - application of test of constitutionality outlined in Lange case - argues that two-tier approach be abandoned - if a law regulates the content of a political communication, not its mode, more rigorous judicial scrutiny will follow - should be a single test for constitutionality where application is through the proportionality framework and informed by the rationale of the implied freedom - application to Australian racial vilification laws.

Validation of the use of input-output data for embodied energy analysis of the Australian construction industry

This paper evaluates a recently developed hybrid method for the embodied energy analysis of the Australian construction industry. It was found that the truncation associated with process analysis can be up to 80%, whilst the use of input-output analysis alone does not always provide a perfect model for replacing process data. There is also a considerable lack in the quantity and possibly quality of process data currently available. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependant upon data quality and availability. The hybrid method evaluated can be used for the optimisation of embodied energy and for identifying opportunities for improvements in energy efficiency.

Competitive interactions between the Australian native fish Galaxiasmaculatus and the exotic mosquitofish Gambusiaholbrooki,in a series of laboratory experiments

Competitive interactions between Galaxias maculatus, native to southeastern Australia, and Gambusia holbrooki, an exotic pest, were examined in relation to two types of artificial cover and a food source. Experiments were performed in an 800 l tank using photographic techniques. The relative distance of G. maculatus from cover or food source before and after the introduction of G. holbrooki were compared. Also, the proportions of the species were altered to examine the effects of unequal numbers on dominance behaviour. It was found that G. holbrooki was unable to out compete G. maculatus for either cover or food. The distance of G. maculatus from a food source was seen to increase following the introduction of G. holbrooki, when they outnumbered G. maculatus by 3 to 1. Although the distance from the food of G.maculatus increased following the introduction of G. holbrooki, in all cases the mean distance of G.␣maculatus from cover or food was less than that of G. holbrooki. Significant intra-species competition appeared to occur between G. maculatus and it may be that this competition had a greater effect than the competitive pressure G. holbrooki was able to place on the natives. This study revealed that the exotic pest species, G. holbrooki, could not out compete a small native Australian fish species.

Mitochondrial DNA sequence and gene organization in the Australian Blacklip Abalone Haliotis rubra (Leach)

The complete mitochondrial DNA of the blacklip abalone Haliotis rubra (Gastropoda: Mollusca) was cloned and 16,907 base pairs were sequenced. The sequence represents an estimated 99.85% of the mitochondrial genome, and contains 2 ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes found in other metazoan mtDNA. An AT tandem repeat and a possible C-rich domain within the putative control region could not be fully sequenced. The H. rubra mtDNA gene order is novel for mollusks, separated from the black chiton Katharina tunicata by the individual translocations of 3 tRNAs. Compared with other mtDNA regions, sequences from the ATP8, NAD2, NAD4L, NAD6, and 12S rRNA genes, as well as the control region, are the most variable among representatives from Mollusca, Arthropoda, and Rhynchonelliformea, with similar mtDNA arrangements to H. rubra. These sequences are being evaluated as genetic markers within commercially important Haliotis species, and some applications and considerations for their use are discussed.

Moving personal tax online: the Australian Taxation Office's E-Tax initiative

In exploiting the capabilities of online technologies, governments have developed policies and launched projects to conduct transactions and deliver their services through the Internet. The motivations for this include cost cutting, efficiency improvements, service enhancements, and leadership in business transformation. However, these diverse goals are not necessarily consistent, especially in the early stages of implementation. The e-government initiative discussed in this case study (E-Tax) provided an additional service to individual Australian taxpayers by enabling them to file their tax returns online. This case study provides an analysis of the E-Tax implementation in the first three years of its operation. Data on E-Tax use compared to other filing methods show that the package worked well technically, was favorably received by users, and was consistent with policy on e-government. However, adoption levels in the early stages did not meet government targets. The analysis suggests that impediments to a greater level of E-Tax use included entrenched patterns of filing, the nature of the taxation system, and political sensitivities. The E-Tax case demonstrates how complex e-government projects can be and the need to take contextual factors into account in planning and evaluating e-government implementation.

Phylogeny of the Australian freshwater crayfish Cherax destructor-complex (Decapoda:Parastacidae) inferred from four mitochondrial gene regions

The phylogenetic relationships among 32 individuals of Australian freshwater crayfish belonging to the Cherax destructor-complex were investigated using a dataset comprising sequences from four mitochondrial gene regions: the large subunit rRNA (16S rRNA), cytochrome oxidase I (COI), adenosine triphosphatase 6 (ATPase 6), and cytochrome oxidase III (COIII). A total of 1602 bp was obtained, and a combined analysis of the data produced a tree with strong support (bootstrap values 94–100%) for three divergent lineages, verifying the phylogenetic hypotheses of relationships within the C. destructor species-complex suggested in previous studies. Overall, sequences from the 16S rRNA gene showed the least variation compared to those generated from protein coding genes, which presented considerably greater levels of divergence. The level of divergence within C. destructor was found to be greater than that observed in other species of freshwater crayfish, but interspecific variation among species examined in the present study was similar to that reported previously.

Economic performance analysis of the Australian property sector using input-output tables

The property sector has played an important role with its growing contribution in the national income and employment in the Australian economy. There is an increasing research need in measuring and analysing the economic performance of the Australian property sector at a country level and input-output tables are considered as an appropriate tool. This paper aims to analyse and measure the performance and sectoral linkages of the Australian property sector using the five latest input-output tables compiled by the Australian Bureau of Statistics. Findings suggested that the Australian residential property sector had played a more important role than the commercial sector in the economy. The backward linkage of the residential property sector showed a decreasing economic pull, while that of commercial property presented an upward pattern. Moreover. the Australian property sector showed a medium economic push to the national economy over the examined period. Findings can aid policy makers, the property sector and researchers in evaluating the competitive ability of the property sector in Australia.