Comparative phylogeography of alpine invertebrates indicates deep lineage diversification and historical refugia in the Australian Alps

Aim: Comparative phylogeographic analyses of alpine biota from the Northern Hemisphere have linked patterns of genetic diversification to glacial expansion and contraction events in the Pliocene and Pleistocene. Furthermore, the extent of diversification across species groups appears to be associated with vagility. In this study we test whether these patterns apply to a geologically stable system from eastern Australia with comparatively shallow elevational gradients and minimal influence from historical glacial activity. Location: The Australian Alps, Victoria, eastern Australia. Methods: We considered phylogeographic patterns across five alpine invertebrate species based on mitochondrial and nuclear DNA sequence data. Bayesian inference methods were used to estimate species phylogenies and divergence times among lineages. GIS tools were used to map interpopulation genetic divergence and intrapopulation genetic diversity estimates and to visualize spatial patterns across species, providing insights into patterns of endemism and demographic history. Results: Phylogeographic patterns and the timing of lineage diversification were consistent across taxonomic groups. Mountain summits harbour highly differentiated haplogroups, including summits connected by high-elevational plateaus, pointing to diversifications being maintained since the early to mid-Pleistocene. These findings are consistent with previous studies of alpine mammals and reptiles, demonstrating a high degree of endemism in this region, regardless of species vagility. Main conclusions: The fine spatial scales at which deep genetic differentiation among alpine communities was observed in this study are unprecedented. This suggests that glacial periods have had less of an impact on species distributions and genetic diversity than they have in alpine systems in the Northern Hemisphere. Historical gene flow among sky-island populations has been limited despite connecting snowlines during glacial periods, suggesting that factors other than snow cover have influenced patterns of gene flow in this region. These findings emphasize the unique phylogeographic history affecting Victorian alpine biodiversity, and the importance of conserving biodiversity from multiple mountain summits in this region of high endemism.

Concordance in phylogeography and ecological niche modelling identify dispersal corridors for reptiles in arid Australia

Aim: Using the rock-specialist agamid Ctenophorus caudicinctus as a model, we test hypothesized biogeographical dispersal corridors for lizards in the Australian arid zone (across the western sand deserts), and assess how these dispersal routes have shaped phylogeographical structuring. Location: Arid and semi-arid Australia. Methods: We sequenced a c. 1400 bp fragment of mtDNA (ND2) for 134 individuals of C. caudicinctus as well as a subset of each of the mtDNA clades for five nuclear loci (BDNF, BACH1, GAPD, NTF3, and PRLR). We used phylogenetic methods to assess biogeographical patterns within C. caudicinctus, including relaxed molecular clock analyses to estimate divergence times. Ecological niche modelling (Maxent) was employed to estimate the current distribution of suitable climatic envelopes for each lineage. Results: Phylogenetic analyses identified two deeply divergent mtDNA clades within C. caudicinctus - an eastern and western clade - separated by the Western Australian sand deserts. However, divergences pre-date the Pleistocene sand deserts. Phylogenetic analyses of the nuclear DNA data sets generally support major mtDNA clades, suggesting past connections between the western C. c. caudicinctus populations in far eastern Pilbara (EP) and the lineages to the east of the sand deserts. Ecological niche modelling supports the continued suitability of climatic conditions between the Central Ranges and the far EP for C. c. graafi. Main conclusions: Estimates of lineage ages provide evidence of divergence between eastern and western clades during the Miocene with subsequent secondary contact during the Pliocene. Our results suggest that this secondary contact occurred via dispersal between the Central Ranges and the far EP, rather than the more southerly Giles Corridor. These events precede the origins of the western sand deserts and divergence patterns instead appear associated with Miocene and Pliocene climate change.

Expression of Na+/H+ exchanger mRNA in the gills of the Atlantic hagfish (Myxine glutinosa) in response to metabolic acidosis

Sodium/proton exchangers (NHE) are transmembrane proteins that facilitate the exchange of a Na⁺ ion for a H⁺ ion across cellular membranes. The NHE are present in the gills of fishes and are believed to function in acid-base regulation by driving the extrusion of protons across the branchial epithelium in exchange for Na⁺ in the water. In this study, we have used reverse transcriptase-polymerase chain reaction (RT-PCR) to detect the presence of a branchial NHE in the gills of the Atlantic hagfish, Myxine glutinosa. The subsequent partial cDNA sequence shares homology with other vertebrate and invertebrate NHE isoforms. In addition, using semi-quantitative, multiplex RT-PCR we demonstrate that mRNA expression of hagfish gill NHE is upregulated following an induced metabolic acidosis. Expression was increased to 4.4 times basal levels at 2-h post-infusion and had decreased to 1.6 times basal by 6 h. Expression had returned to basal levels by 24-h post-infusion. The inference from this study is that a gill NHE which is potentially important in acid-base regulation has been present in the vertebrate lineage since before the divergence of the hagfishes from the main vertebrate line.

Leadership for socially just schooling: more substance and less style in high-risk, low-trust times?

This article argues that radical shifts in school governance arising from wider social, political, and economic relations toward what are described as high-risk and low-trust societies challenge past notions of leadership. I explore the tensions between the pluralism of postmodernist thinking and modernist notions of social justice that produce "predicaments" for school leaders through a series of paradoxes of educational management around centralized decentralization, markets and management, new educational professionalism, parental choice and community participation, and between the substance and style of leadership. The values underpinning the corporatization of public and private life most evident in education do not provide a satisfactory grounding for effective school leadership.

Lack of genetic divergence found with microsatellite DNA markers in the tarakihi Nemadactylus macropterus

Three classes of molecular markers are commonly employed during population genetic studies of marine taxa: allozymes, mitochondrial DNA (mtDNA), and microsatellite DNA. These markers differ in their levels of polymorphism, and the ease and cost of their application. Nemadactylus macropterus is a commercially important marine fish from New Zealand and southern Australia that has been the subject of genetic (allozyme, mtDNA) and non-genetic (otolith microchemistry, larval advection) studies of stock structure. We collected microsatellite DNA data from this species to compare the utility of these molecular markers with those genetic methods previously applied to N. macropterus. Microsatellites did not indicate significant divergence among Australian samples, or between Australian and New Zealand samples. The latter is incongruent with the allozyme and mtDNA studies, and it is suggested that allelic homoplasy has hindered the resolution of population structure when using microsatellites.

The times are they a-changin'? Can the Commonwealth parliament legislate for same sex marriages?

This article considers whether the marriage power contained in the Australian Constitution could support a Commonwealth law that recognised same sex marriages. To this end and after outlining the current constitutional meaning according to the High Court, three methods used for interpreting constitutional terms (connotation/denotation, moderate originalism, non-originalism) are examined to ascertain whether they could source such a law to the marriage power. It is submitted that none can do so without betraying their own core interpretative principle or the text and structure of the Constitution. However an alternative method for interpreting [*2] constitutional terms is proffered which may be able to establish a sufficient connection between a law that recognises same sex marriages and the marriage power. It involves recognising 'marriage' as a constitutionalised legal term of art whose meaning can be informed by developments since federation in common law and statute.

Macleod and the offence of defrauding the company in one-person businesses: the divergence between legal principle and logic widens

The recent High Court decision in Macleod v R establishes that a director and sole shareholder may be convicted of fraudulently applying a company's property even though the person has consented to the personal use of the company's property. It is contended that while this decision is consistent with the weight of precedent, it is wrong in principle. The decision implies that corporations are not only separate legal entities, but that they are highly virtuous legal entities -- incapable of being imbued with the dishonest intentions and activities of the individuals controlling the company.

The presence of an-other: the prescience of racism in post-modern times

In this paper, I explore conversations with teachers and parents at one Melbourne secondary school, as the modern definition of identity,defined at the end of the 1980s, took on the fluidity of post-modern definition a decade later. Even as identification seemed contingent and negotiated, and difference seemed to disappear, teachers and parents continued to understand their identity in relation to the ambivalent definition of others. This became increasingly frightening as notions of otherness, and therefore of self, became increasingly fluid and unclear. That which seemed other and outside, now appears as part-of-us and inside-us-all. Even as descriptions of difference, and thereforeidentity, become more fluid, conceptions of otherness – and therefore – self, do not disappear. Prescient manifestations of exclusion and racism are contiguous with, yet in juxtaposition to, older forms.

Conservation, duplication and divergence of the zebrafish stat5 genes

There are seven mammalian signal transducer and activator of transcription (Stat) proteins that act downstream of cytokine and growth factor receptors to mediate rapid changes in gene expression. The mammalian Stat5a and Stat5b genes show high sequence identity and lie adjacent in a head-to-head configuration next to the Stat3 gene, apparently the result of a relatively recent mammal-specific gene duplication event. We have identified and characterized two stat5 homologues that are expressed in zebrafish, named stat5.1 and stat5.2. The stat5.1 gene shows a high level of conservation with the single stat5 gene found in other teleosts and lies next to the stat3 gene, in the same relative orientation as the mammalian Stat5b gene. In contrast, the stat5.2 gene lies on a different chromosome to stat5.1 and stat3, and has diverged from the stat5 genes of other teleosts, with no apparent orthologue. Together, these data suggest that the ancestral Stat5 gene has undergone two independent gene duplication events to generate a stat5.2 paralogue in zebrafish and a Stat5a paralogue in mammals.

Perspectives of another: conceiving of ourselves in critical times

This article takes as its focus newspaper articles chosen from a Melbourne newspaper published annually on a particular day, between 1988 and 2003. The resultant bricolage provides a backdrop through which contemporary conversations about race and ethnic relations in Australian contexts can be examined. Australian educational institutions, particularly those in major cities such as Melbourne and Sydney have long been implicated in the provision of immigrant education. Over the last decade Australia follows the United States and Britain as major suppliers of international education. Under explanation here are the changed ways that race and ethnic relations can be understood and the implications of these changes for the ways that these new directions in education can be spoken about.

Leading as emotional management work in high risk times: the counterintuitive impulses of performativity and passion

This paper explores, through a case study of educational restructuring in Victoria, Australia, how school leaders in a public education system in Australia mediate reform discourses emphasizing managerial and market accountability and the emotional and messy work of teaching and leading. These accountability exercises were often seen by teachers and principals to be distractions; more about reporting and recording, rather than addressing substantive educational issues. They simultaneously distanced teachers and leaders from the 'real' and 'passionate' work of education while appropriating and commodifying teachers' and leaders' emotions and desires to do well. School leaders were expected to manage the emotional performances of their students, parents and colleagues as well as themselves. They also managed the emotions arising from the dissonance between teachers' professional and personal commitment to making a difference for all students based on principles of equity and the performativity requirements based on efficiency and narrowly defined and predetermined criteria of effectiveness and success that often undermined improvement for many students. In that sense performativity ('being seen to be good') and passion (for 'doing good') often produced counterintuitive impulses.

On purely gravito-magnetic vacuum space-times

It is shown that there are no purely magnetic, vacuum, spacetime metrics where any one of the following conditions holds: (a) the ratio of any two eigenvalues of the Weyl tensor is constant, (b) both of the Riemann principal null directions, defining the time-like blade, are nonrotating, (c) the shear tensor possesses an eigenvector v^a which is defined by one of the space-like Riemann principal directions, (d) the vorticity is parallel to v^a, where v^a is defined by one of the space-like Riemann principal directions.