Cell migration and proliferation on homogeneous and non-homogeneous domains : modelling on the scale of individuals and populations

Cell migration is a behaviour critical to many key biological effects, including wound healing, cancerous cell invasion and morphogenesis, the development of an organism from an embryo. However, given that each of these situations is distinctly different and cells are extremely complicated biological objects, interest lies in more basic experiments which seek to remove conflating factors and present a less complex environment within which cell migration can be experimentally examined. These include in vitro studies like the scratch assay or circle migration assay, and ex vivo studies like the colonisation of the hindgut by neural crest cells. The reduced complexity of these experiments also makes them much more enticing as problems to mathematically model, like done here. The primary goal of the mathematical models used in this thesis is to shed light on which cellular behaviours work to generate the travelling waves of invasion observed in these experiments, and to explore how variations in these behaviours can potentially predict differences in this invasive pattern which are experimentally observed when cell types or chemical environment are changed. Relevant literature has already identified the difficulty of distinguishing between these behaviours when using traditional mathematical biology techniques operating on a macroscopic scale, and so here a sophisticated individual-cell-level model, an extension of the Cellular Potts Model (CPM), is been constructed and used to model a scratch assay experiment. This model includes a novel mechanism for dealing with cell proliferations that allowed for the differing properties of quiescent and proliferative cells to be implemented into their behaviour. This model is considered both for its predictive power and used to make comparisons with the travelling waves which result in more traditional macroscopic simulations. These comparisons demonstrate a surprising amount of agreement between the two modelling frameworks, and suggest further novel modifications to the CPM that would allow it to better model cell migration. Considerations of the model’s behaviour are used to argue that the dominant effect governing cell migration (random motility or signal-driven taxis) likely depends on the sort of invasion demonstrated by cells, as easily seen by microscopic photography. Additionally, a scratch assay simulated on a non-homogeneous domain consisting of a ’fast’ and ’slow’ region is also used to further differentiate between these different potential cell motility behaviours. A heterogeneous domain is a novel situation which has not been considered mathematically in this context, nor has it been constructed experimentally to the best of the candidate’s knowledge. Thus this problem serves as a thought experiment used to test the conclusions arising from the simulations on homogeneous domains, and to suggest what might be observed should this non-homogeneous assay situation be experimentally realised. Non-intuitive cell invasion patterns are predicted for diffusely-invading cells which respond to a cell-consumed signal or nutrient, contrasted with rather expected behaviour in the case of random-motility-driven invasion. The potential experimental observation of these behaviours is demonstrated by the individual-cell-level model used in this thesis, which does agree with the PDE model in predicting these unexpected invasion patterns. In the interest of examining such a case of a non-homogeneous domain experimentally, some brief suggestion is made as to how this could be achieved.

Fractional models for the migration of biological cells in complex spatial domains

Travelling wave phenomena are observed in many biological applications. Mathematical theory of standard reaction-diffusion problems shows that simple partial differential equations exhibit travelling wave solutions with constant wavespeed and such models are used to describe, for example, waves of chemical concentrations, electrical signals, cell migration, waves of epidemics and population dynamics. However, as in the study of cell motion in complex spatial geometries, experimental data are often not consistent with constant wavespeed. Non-local spatial models have successfully been used to model anomalous diffusion and spatial heterogeneity in different physical contexts. In this paper, we develop a fractional model based on the Fisher-Kolmogoroff equation and analyse it for its wavespeed properties, attempting to relate the numerical results obtained from our simulations to experimental data describing enteric neural crest-derived cells migrating along the intact gut of mouse embryos. The model proposed essentially combines fractional and standard diffusion in different regions of the spatial domain and qualitatively reproduces the behaviour of neural crest-derived cells observed in the caecum and the hindgut of mouse embryos during in vivo experiments.

Enterprise policy and the metagovernance of firm capabilities

The underlying logic of enterprise policy is that there are impediments to change in economic systems that can be traced to the path-dependent behaviors of economic actors that prevent them from exploring new knowledge and new ways of doing things. Enterprise policy involves firm-level interventions delivered by distributed networks of business advisors coordinated by knowledge intermediaries. These metagovernance arrangements are able to disrupt the path-dependent behaviors of organizations. The logic and benefits of enterprise policy are explored through reference to public administration, strategic management and evolutionary theory, and three case studies.

Revisiting educational equity and quality in China through confucianism, policy, research, and practice

The promotion of educational equity and improvement of educational quality in China are contextualised in tenets of Confucianism and policy directives, inspiring educational research and practice. In this paper, we first explore the historical and cultural roots of educational equity and quality through Confucianism and elaborate on the current policy priority that aims to address educational equity and quality. We then present an overview of research on equity and quality in Chinese education. Informed by Confucianism, policy, and research, we pose a framework to structure our investigation and analysis of three illustrative examples, namely the Special Post Teacher Plan, amalgamation of rural schools, and schooling of floating children. Drawing insights from Confucianism, policy, research, and practice, we conclude that the promotion of educational equity through high quality provision of education for disadvantaged groups can help to narrow the gap in educational quality currently existing in China.

Vietnamese in Australia

Vietnamese-Australians live in Australia, a large island continent. The physical contrast between Vietnam and Australia is remarked upon by many Vietnamese in their migration stories. Whereas Vietnam is remembered as an interlinked sensual and social world, Australia is often viewed as a harsh, spacious, empty, dry continent. Australia is located in a regional Asian context, but this location has always been culturally and politically problematic, as it historically attempted to define itself as a "white" European nation in the Southern Hemisphere(Ang, 2000, p. xiii; McNamara & Coughlan, 1997, p. 1). During the Gold Rush period in the late 1800s, when there was widespread opposition to Chinese labor, Australia implemented a "White Australia" policy, although there were historically a significant number of Australians of Asian background. This exclusionary immigration policy was effectively overturned in the 1970s with the acceptance of a large number of refugees from Vietnam, Cambodia, and Laos in 1975. Vietnamese-Australians live predominantly in urban areas with over three quarters living in Sydney and Melbourne, the two largest cities. Within these two cities they are also highly concentrated in ethnically diverse suburbs, most living in areas with more than 1,000 residents born in Vietnam (Viviani, 1996, p. 49). However, Jupp (Jupp et al., 1990; Jupp, 1993) has argued that these areas are also zones of transition, with much movement in and out...

National cultural policy is bold, but vulnerable

The first major national cultural policy in 19 years was unveiled by Minister for the Arts Simon Crean on 13 March 2013. Minister Crean has called it “a national cultural policy for the decade.” Uncharitable souls might ask “which decade?”, given that it was first promised soon after the election of the Rudd government in 2007. It is, however, a bold and forward-looking statement. In marked contrast to the limited detail provided by Communications Minister Stephen Conroy in support of the media reforms he recently announced, more than 150 pages Creative Australia outlines a comprehensive set of proposals for immediate action, and some aspirations for the longer term. Like the media reforms, however, it may not survive if there is a change in government in September.

A socially just rationale for an Australian curriculum? : a critical thematic policy analysis of political speeches in education (2007-2010)

In late 2007, newly elected Prime Minister Kevin Rudd placed education reform on centre stage as a key policy in the Labor Party's agenda for social reform in Australia. A major policy strategy within this 'Education Revolution' was the development of a national curriculum, the Australian Curriculum Within this political context, this study is an investigation into how social justice and equity have been used in political speeches to justify the need for, and the nature of, Australia's first official national curriculum. The aim is to provide understandings into what is said or not said; who is included or excluded, represented or misrepresented; for what purpose; and for whose benefit. The study investigates political speeches made by Education Ministers between 2008 and 201 0; that is, from the inception of the Australian Curriculum to the release of the Phase 1 F - 10 draft curriculum documents in English, mathematics, science and history. Curriculum development is defined here as an ongoing process of complex conversations. To contextualise the process of curriculum development within Australia, the thesis commences with an initial review of curriculum development in this nation over the past three decades. It then frames this review within contemporary curriculum theory; in particular it calls upon the work of William Pinar and the key notions of currere and reconceptualised curriculum. This contextualisation work is then used as a foundation to examine how social justice and equity have been represented in political speeches delivered by the respective Education Ministers Julia Gillard and Peter Garrett at key junctures of Australian Curriculum document releases. A critical thematic policy analysis is the approach used to examine selected official speech transcripts released by the ministerial media centre through the DEEWR website. This approach provides a way to enable insights and understandings of representations of social justice and equity issues in the policy agenda. Broader social implications are also discussed. The project develops an analytic framework that enables an investigation into the framing of social justice and equity issues such as inclusion, equality, quality education, sharing of resources and access to learning opportunities in political speeches aligned with the development of the Australian Curriculum Through this analysis, the study adopts a focus on constructions of educationally disadvantaged students and how the solutions of 'fixing' teachers and providing the 'right' curriculum are presented as resolutions to the perceived problem. In this way, it aims to work towards offering insights into political justifications for a national curriculum in Australia from a social justice perspective.

Academics and activists in the policy process : engagement with Australian media inquiries 2011-13

After its narrow re-election in June 2010, the Australian Labor government undertook a series of public inquiries into reform of Australian media, communications and copyright laws. One important driver of policy reform was the government’s commitment to building a National Broadband Network (NBN), and the implications this had for existing broadcasting and telecommunications policy, as it would constitute a major driver of convergence of media and communications access devices and content platforms. These inquiries included: the Convergence Review of media and communications legislation; the Australian Law Reform Commission (ALRC) review of the National Classification Scheme; the Independent Media Inquiry (Finkelstein Review) into Media and Media Regulation; and the ALRC review of Copyright and the Digital Economy. One unusual feature of this review process, discussed in the paper, was the degree to which academics were involved in the process, not simply as providers of expert opinion, but as review chairs seconded from their universities. This paper considers the role played by activist groups in all of these inquiries and their relationship to the various participants in the inquiries, as well as the implications of academics being engaged in such inquiries, not simply as activist-scholars, but as those primarily responsible for delivering policy review outcomes. The latter brings to the forefront issues arising in from direct engagement with governments and state agencies themselves, which challenges traditional understandings of the academic community as “critical outsiders” towards such policy processes.

Re-orientations : East Asian popular cultures in contemporary Vietnam

Vietnamese-Australians live in Australia, a large island continent. The physical contrast between Vietnam and Australia is remarked upon by many Vietnamese in their migration stories. Whereas Vietnam is remembered as an interlinked sensual and social world, Australia is often viewed as a harsh, spacious, empty, dry continent. Australia is located in a regional Asian context, but this location has always been culturally and politically problematic, as it historically attempted to define itself as a "white" European nation in the Southern Hemisphere (Ang, 2000, p. xiii; McNamara & Coughlan, 1997, p. 1). During the Gold Rush period in the late 1800s, when there was widespread opposition to Chinese labor, Australia implemented a "White Australia" policy, although there were historically a significant number of Australians of Asian background. This exclusionary immigration policy was effectively overturned in the 1970s with the acceptance of a large number of refugees from Vietnam, Cambodia, and Laos in 1975. Vietnamese-Australians live predominantly in urban areas with over three quarters living in Sydney and Melbourne, the two largest cities. Within these two cities they are also highly concentrated in ethnically diverse suburbs, most living in areas with more than 1,000 residents born in Vietnam (Viviani, 1996, p. 49). However, Jupp (Jupp et al., 1990; Jupp, 1993) has argued that these areas are also zones of transition, with much movement in and out.

Introduction : the anthropology of migration

This introduction to the volume places the study of migration within the wider processes of social change and the complex actions of class, gender and ethnicity that are integrated into the experience of displacement. It argues that the articles in this volume contribute important new ethnographic and theoretical analyses to our knowledge and understanding of the constraints and the opportunities provided by cultural diversity in several societies by elaborating upon recent advances made in conceptualisations of migrancy. It places particular emphasis on developing phenomenological approaches to migration studies which incorporate the lived experience of migrants into any analysis. It also suggests that redressing the neglect of this area of study in Australia has the possibility of generating informed interruptions into the current political shift towards divisive public debates on immigration and cultural pluralism.

Generate : Youth Culture and Migration Heritage in Western Sydney

Executive Summary This report is the first in-depth exploration of identity and popular culture among Middle Eastern and Asian youth. It documents preliminary research findings on the contribution of Middle Eastern and Asian youth to Sydney’s cultural life and migration heritage. While young people from these communities, the largest migrant communities in NSW, are often negatively portrayed, this research has focused on their social practices of cultural invention, opening up new and creative means of mobilising cultural difference. These young people’s cultural negotiations between migrant family background and the wider society require real engagement with difference and provide rich resources for invigorating the multicultural fabric of the nation. Their repertoire of cultural skills and their involvement in different cultural worlds are often viewed as evidence of not ‘belonging’ to the mainstream or dominant culture. However, the results of our research reveal that the ‘in-betweenness’ of these young people often enables them to move easily between different social and cultural groupings, embracing cultural diversity as inherent and integral to their everyday experience, that is, ‘normal’ to urban life. In this report, we document the changing nature of friendship networks and family relations, the particular meanings and uses of different languages and expressions, and the patterns of consumption of Middle Eastern and Asian youth. In these everyday activities these young people contribute to a changing migration heritage and are redefining what it means to be Australian.

Revisiting the trajectories of special teacher education in China through policy and practice

The preparation, recruitment, work, and career of teachers are important in education. This is no exemption for special education. However, the shortage of qualified teachers serving students with disabilities has long been an international problem. In China, both the quantity and the quality of special education teachers are of concern. This places unrelenting pressure on special teacher education. Given its growing size and challenges, special teacher education has received increasing attention from research, policy, and practice. However, there is a dearth of scholarship published in English to address these issues. To the best of our belief and knowledge, there is no systematic, comprehensive, and contextualised examination of special teacher education in China to date. This paper aims to make a contribution in this regard. First, we present the complexities of the Chinese context in which special teacher education is situated. Second, we synthesise recent literature on special teacher education in China through an extensive review of the relevant studies scattered in English publications. Third, we provide insights into special teacher education in China, regarding its trajectory of policy making, its history of development, and its strategies and challenges. Finally, we conclude our paper with some practical recommendations to aid the future development of special teacher education.