Spatial and temporal variation in algal-assemblage structure in isolated dryland river waterholes, Cooper Creek and Warrego River, Australia

The scale at which algal biodiversity is partitioned across the landscape, and the biophysical processes and biotic interactions which shape these communities in dryland river refugia was studied on two occasions from 30 sites in two Australian dryland rivers. Despite the waterholes studied having characteristically high levels of abiogenic turbidity, a total of 186 planktonic microalgae, 253 benthic diatom and 62 macroalgal species were recorded. The phytoplankton communities were dominated by flagellated cryptophytes, euglenophytes and chlorophytes, the diatom communities by cosmopolitan taxa known to tolerate wide environmental conditions, and the macroalgal communities by filamentous cyanobacteria. All algal communities showed significant differences between catchments and sampling times, with a suite of between 5 and 12 taxa responsible for similar to 50% of the observed change. In general, algal assemblage patterns were poorly correlated with the measured environmental variables. Phytoplankton and diatom assemblage patterns were weakly correlated with several waterhole geomorphic measures, whereas macroalgal assemblage patterns showed some association with variability in ionic concentration.

Genetic structure and male-mediated gene flow in the ghost bat (Macroderma gigas)

The Australian ghost bat is a large, opportunistic carnivorous species that has undergone a marked range contraction toward more mesic, tropical sites over the past century. Comparison of mitochondrial DNA (mtDNA) control region sequences and six nuclear microsatellite loci in 217 ghost bats from nine populations across subtropical and tropical Australia revealed strong population subdivision (mtDNA phi(ST) = 0.80; microsatellites URST = 0.337). Low-latitude (tropical) populations had higher heterozygosity and less marked phylogeographic structure and lower subdivision among sites within regions (within Northern Territory [NT] and within North Queensland [NQ]) than did populations at higher latitudes (subtropical sites; central Queensland [CQ]), although sampling of geographically proximal breeding sites is unavoidably restricted for the latter. Gene flow among populations within each of the northern regions appears to be male biased in that the difference in population subdivision for mtDNA and microsatellites (NT phi(ST) = 0.39, URST = 0.02; NQ phi(ST) = 0.60, URST = -0.03) is greater than expected from differences in the effective population size of haploid versus diploid loci. The high level of population subdivision across the range of the ghost bat contrasts with evidence for high gene flow in other chiropteran species and may be due to narrow physiological tolerances and consequent limited availability of roosts for ghost bats, particularly across the subtropical and relatively arid regions. This observation is consistent with the hypothesis that the contraction of the species' range is associated with late Holocene climate change. The extreme isolation among higher-latitude populations may predispose them to additional local extinctions if the processes responsible for the range contraction continue to operate.

Trust and psychological strain experienced by employees during organisational change

Most modern models of personality are hierarchical, perhaps as a result of their development by means of exploratory factor analysis. Based on new ideas about the structure of personality and how it divides into biologically based and sociocognitively based components (as proposed by Carver, Cloninger, EUiot and Thrash, and ReveUe), I develop a series of rules that show how scales of personality may be linked from those that are most distal to those which are most proximal. I use SEM to confirm the proposed structure in scales of the Temperament Character Inventory (TCI) and the Eysenck Personality Profiler. Good fit is achieved and all proposed paths are significant. The model is then used to predict work performance, deviance and job satisfacdon.

Voices of lay principals: Promoting a Catholic character and culture in schools in an era of change

This paper reports a qualitative study of the practice of leadership in Catholic schools to ascertain the perceptions of lay principals, who as positional leaders play a critical role in embracing and creatively rebuilding the Catholic vision of life within the reality that the Catholic school principalship is now a ministry of the laity. The methodology included semi-structured interviews, field notes, reflexive journals, direct observation, and document nalysis. The study examined both individual human behaviour and the structure of the social order in Catholic schools. The findings point towards successful leadership in Catholic schools being highly influenced by the cultural and spiritual capital that a principal brings to a school signifying a fundamental importance of appointing principals who are not only professionally competent but spiritually as well. In an era of unprecedented social, educational and ecclesial change, and with an ever widening role description, lay principals are challenged to redefine and re-articulate their Catholic character and identity, and will need to look for new ways to make this explicit. Embracing a new leadership paradigm of shared leadership, the preparation and on-going formation of lay principals were identified as critical for the continuance of the Catholic school’s distinctive mission in the future.