Using network mesures to test evolved NK-landscapes

In this paper we empirically investigate which are the structural characteristics that can help to predict the complexity of NK-landscape instances for estimation of distribution algorithms. To this end, we evolve instances that maximize the estimation of distribution algorithm complexity in terms of its success rate. Similarly, instances that minimize the algorithm complexity are evolved. We then identify network measures, computed from the structures of the NK-landscape instances, that have a statistically significant difference between the set of easy and hard instances. The features identified are consistently significant for different values of N and K.

Climbing Combinatorial Fitness Landscapes

International audience

Reflection on the 'Landscapes of Rights' Conference, Adelaide, 2009

This article presents a reflective view of three teaching colleagues from Queensland University of Technology, Brisbane who had attended and participated in the 'Landscapes of Rights' Conference in Adelaide, July 2009. The conference is a biennial event run by the Reggio Emilia-Australia Information Exchange. The authors explore and reflect on the provocations posed throughout this conference and consider these in light of their ongoing work in the field of teacher education, of early childhood teaching and as active supporters of children's rights.

Media scepticism, media diets and media landscapes: A consideration of US versus Australian political information environments

The range of political information sources available to modern Australians is greater and more varied today than at any point in the nation’s history, incorporating print, broadcast, Internet, mainstream and non-mainstream media. In such a competitive media environment, the factors which influence the selection of some information sources above others are of interest to political agents, media institutions and communications researchers alike. A key factor in information source selection is credibility. At the same time that the range of political information sources is increasing rapidly, due to the development of new information and communication technologies, audience research suggests that trust in mainstream media organisations in many countries is declining. So if people distrust the mainstream media, but have a vast array of alternative political information sources available to them, what do their personal media consumption patterns look like? How can we analyse such media consumption patterns in a meaningful way? In this paper I will briefly map the development of media credibility research in the US and Australia, leading to a discussion of one of the most recent media credibility constructs to be shown to influence political information consumption, media scepticism. Looking at the consequences of media scepticism, I will then consider the associated media consumption construct, media diet, and evaluate its usefulness in an Australian, as opposed to US, context. Finally, I will suggest alternative conceptualisations of media diets which may be more suited to Australian political communications research.

The intention to notice : the collection, the tour and ordinary landscapes

The Intention to Notice: the collection, the tour and ordinary landscapes is concerned with how ordinary landscapes and places are enabled and conserved through making itineraries that are framed around the ephemera encountered by chance, and the practices that make possible the endurance of these material traces. Through observing and then examining the material and temporal aspects of a variety of sites/places, the museum and the expanded garden are identified as spaces where the expression of contemporary political, ecological and social attitudes to cultural landscapes can be realised through a curatorial approach to design, to effect minimal intervention. Three notions are proposed to encourage investigation into contemporary cultural landscapes: To traverse slowly to allow space for speculations framed by the topographies and artefacts encountered; to [re]make/[re]write cultural landscapes as discursive landscapes that provoke the intention to notice; and to reveal and conserve the fabric of everyday places. A series of walking, recording and making projects undertaken across a variety of cultural landscapes in remote South Australia, Melbourne, Sydney, London, Los Angeles, Chandigarh, Padova and Istanbul, investigate how communities of practice are facilitated through the invitation to notice and intervene in ordinary landscapes, informed by the theory and practice of postproduction and the reticent auteur. This community of practice approach draws upon chance encounters and it seeks to encourage creative investigation into places. The Intention to Notice is a practice of facilitating that also leads to recording traces and events; large and small, material and immaterial, that encourages both conjecture and archive. Most importantly, there is an open-ended invitation to commit and exchange through design interaction.

‘You can interview me, but I don’t have a story’: Local Accounts of Wandering Women, Rewondering Queensland Landscapes.

This paper investigates how contemporary works of women’s travel writing are reworking canonical formations of environmental literature by presenting imaginative accounts of travel writing that are both literal and metaphorical. In this context, the paper considers how women who travel/write may intersect the spatial hybridities of travel writing and nature writing, and in doing so, create a new genre of environmental literature that is not only ecologically sensitive but gendered. As the role of female travel writers in generating this knowledge is immense but largely unexamined, this paper will investigate how a feminist geography can be applied, both critically and creatively, to local accounts of travel. It will draw on my own travels around Queensland in an attempt to explore how many female storytellers situate themselves, in and against, various discourses of mobility and morality.

Influence of historical landscapes, drainage evolution and ecological traits on patterns of genetic diversity in Southeast Asian freshwater snakehead fishes

Snakehead fishes in the family Channidae are obligate freshwater fishes represented by two extant genera, the African Parachannna and the Asian Channa. These species prefer still or slow flowing water bodies, where they are top predators that exercise high levels of parental care, have the ability to breathe air, can tolerate poor water quality, and interestingly, can aestivate or traverse terrestrial habitat in response to seasonal changes in freshwater habitat availability. These attributes suggest that snakehead fishes may possess high dispersal potential, irrespective of the terrestrial barriers that would otherwise constrain the distribution of most freshwater fishes. A number of biogeographical hypotheses have been developed to account for the modern distributions of snakehead fishes across two continents, including ancient vicariance during Gondwanan break-up, or recent colonisation tracking the formation of suitable climatic conditions. Taxonomic uncertainty also surrounds some members of the Channa genus, as geographical distributions for some taxa across southern and Southeast (SE) Asia are very large, and in one case is highly disjunct. The current study adopted a molecular genetics approach to gain an understanding of the evolution of this group of fishes, and in particular how the phylogeography of two Asian species may have been influenced by contemporary versus historical levels of dispersal and vicariance. First, a molecular phylogeny was constructed based on multiple DNA loci and calibrated with fossil evidence to provide a dated chronology of divergence events among extant species, and also within species with widespread geographical distributions. The data provide strong evidence that trans-continental distribution of the Channidae arose as a result of dispersal out of Asia and into Africa in the mid–Eocene. Among Asian Channa, deep divergence among lineages indicates that the Oligocene-Miocene boundary was a time of significant species radiation, potentially associated with historical changes in climate and drainage geomorphology. Mid-Miocene divergence among lineages suggests that a taxonomic revision is warranted for two taxa. Deep intra-specific divergence (~8Mya) was also detected between C. striata lineages that occur sympatrically in the Mekong River Basin. The study then examined the phylogeography and population structure of two major taxa, Channa striata (the chevron snakehead) and the C. micropeltes (the giant snakehead), across SE Asia. Species specific microsatellite loci were developed and used in addition to a mitochondrial DNA marker (Cyt b) to screen neutral genetic variation within and among wild populations. C. striata individuals were sampled across SE Asia (n=988), with the major focus being the Mekong Basin, which is the largest drainage basin in the region. The distributions of two divergent lineages were identified and admixture analysis showed that where they co-occur they are interbreeding, indicating that after long periods of evolution in isolation, divergence has not resulted in reproductive isolation. One lineage is predominantly confined to upland areas of northern Lao PDR to the north of the Khorat Plateau, while the other, which is more closely related to individuals from southern India, has a widespread distribution across mainland SE Asian and Sumatra. The phylogeographical pattern recovered is associated with past river networks, and high diversity and divergence among all populations sampled reveal that contemporary dispersal is very low for this taxon, even where populations occur in contiguous freshwater habitats. C. micropeltes (n=280) were also sampled from across the Mekong River Basin, focusing on the lower basin where it constitutes an important wild fishery resource. In comparison with C. striata, allelic diversity and genetic divergence among populations were extremely low, suggesting very recent colonisation of the greater Mekong region. Populations were significantly structured into at least three discrete populations in the lower Mekong. Results of this study have implications for establishing effective conservation plans for managing both species, that represent economically important wild fishery resources for the region. For C. micropeltes, it is likely that a single fisheries stock in the Tonle Sap Great Lake is being exploited by multiple fisheries operations, and future management initiatives for this species in this region will need to account for this. For C. striata, conservation of natural levels of genetic variation will require management initiatives designed to promote population persistence at very localised spatial scales, as the high level of population structuring uncovered for this species indicates that significant unique diversity is present at this fine spatial scale.