Cell density alters matrix accumulation in two distinct fractions and the mechanical integrity of alginate-chondrocyte constructs

Chondrocyte density in articular cartilage is known to change with the development and growth of the tissue and may play an important role in the formation of a functional extracellular matrix (ECM). The objective of this study was to determine how initial chondrocyte density in an alginate hydrogel affects the matrix composition, its distribution between the cell-associated (CM) and further removed matrix (FRM) fractions, and the tensile mechanical properties of the developing engineered cartilage. Alginate constructs containing primary bovine chondrocytes at densities of 0, 4, 16, and 64 million cells/ml were fabricated and cultured for 1 or 2 weeks, at which time structural, biochemical, and mechanical properties were analyzed. Both matrix content and distribution varied with the initial cell density. Increasing cell density resulted in an increasing content of collagen and sulfated-glycosaminoglycan (GAG) and an increasing proportion of these molecules localized in the CM. While the equilibrium tensile modulus of cell-free alginate did not change with time in culture, the constructs with highest cell density were 116% stiffer than cell-free controls after 2 weeks of culture. The equilibrium tensile modulus was positively correlated with total collagen (r2 = 0.47, p < 0.001) and GAG content (r2 = 0.68, p < 0.001), and these relationships were enhanced when analyzing only those matrix molecules in the CM fraction (r2 = 0.60 and 0.72 for collagen and GAG, respectively, each p < 0.001). Overall, the results of this study indicate that initial cell density has a considerable effect on the developing composition, structure, and function of alginate–chondrocyte constructs.

Modulation of depth-dependent properties in tissue-engineered cartilage with a semi-permeable membrane and perfusion : a continuum model of matrix metabolism and transport

The functional properties of cartilaginous tissues are determined predominantly by the content, distribution, and organization of proteoglycan and collagen in the extracellular matrix. Extracellular matrix accumulates in tissue-engineered cartilage constructs by metabolism and transport of matrix molecules, processes that are modulated by physical and chemical factors. Constructs incubated under free-swelling conditions with freely permeable or highly permeable membranes exhibit symmetric surface regions of soft tissue. The variation in tissue properties with depth from the surfaces suggests the hypothesis that the transport processes mediated by the boundary conditions govern the distribution of proteoglycan in such constructs. A continuum model (DiMicco and Sah in Transport Porus Med 50:57-73, 2003) was extended to test the effects of membrane permeability and perfusion on proteoglycan accumulation in tissue-engineered cartilage. The concentrations of soluble, bound, and degraded proteoglycan were analyzed as functions of time, space, and non-dimensional parameters for several experimental configurations. The results of the model suggest that the boundary condition at the membrane surface and the rate of perfusion, described by non-dimensional parameters, are important determinants of the pattern of proteoglycan accumulation. With perfusion, the proteoglycan profile is skewed, and decreases or increases in magnitude depending on the level of flow-based stimulation. Utilization of a semi-permeable membrane with or without unidirectional flow may lead to tissues with depth-increasing proteoglycan content, resembling native articular cartilage.

Indigenous Australians and Islam : spiritual, cultural, and political alliances

This thesis examines why and how Indigenous Australians convert to Islam in the New South Wales suburbs of Redfern and Lakemba. It is argued that conventional religious conversion theories inadequately account for religious change in the circumstances outlined in this study. The aim of the thesis is to apply a sociological-historical methodology to document and analyse both Indigenous and Islamic pathways eventuating in Indigenous Islamic alliances. All of the Indigenous men interviewed for this research have had contact with Islam either while incarcerated or involved with the criminal justice system. The consequences of these alliances for the Indigenous men constitute the contribution the study makes to new knowledge. The study employs a socio-historical and sociological focus to account for the underlying issues by a literature review followed by an ethnographic participant observation methodology. In-depth open-ended interviews with key informants provided the rich qualitative data to compliment literature review findings. For the Indigenous people involved in this study, Islamic religious identity combined with resistance politics formed a significant empowering framework. For them it is a symbolic representation of anti-colonialism and the enduring scourge of social dysfunction in some Indigenous communities.

How to tell the difference between a positive image and a stereotype: reading Priscilla, Queen of the Desert

This paper intervenes in critical discussions about the representation of homosexuality. Rejecting the ‘manifest content’ of films, it turns to cultural history to map those public discourses which close down the ways in which films can be discussed. With relation to The Adventures of Priscilla, Queen of the Desert, it examines discussions of the film in Australian newspapers (both queer and mainstream) and finds that while there is disagreement about the interpretation to be made of the film, the terms within which those interpretations can be made are quite rigid. A matrix based on similarity, difference and value provides a series of positions and a vocabulary (transgression, assimilation, positive images and stereotypes) through which to make sense of this film. The article suggests that this matrix, and the idea that similarity and difference provide a suitable axis for making sense of homosexual identity, are problematic in discussing homosexual representation.

Local and global : cultural globalization, consumerism, and children's fiction

According to Zygmunt Bauman in Liquid Modernity (2000), the formerly solid and stable institutions of social life that characterised earlier stages of modernity have become fluid. He sees this as an outcome of the modernist project of progress itself, which in seeking to dismantle oppressive structures failed to reconstruct new roles for society, community and the individual. The un-tethering of social life from tradition in the latter stages of the twentieth century has produced unprecedented freedoms and unparalleled uncertainties, at least in the West. Although Bauman’s elaboration of some of the features and drivers of liquid modernity – increased mobility, rapid communications technologies, individualism – suggests it to be a neologism for globalisation, it is arguably also the context which has allowed this phenomenon to flourish. The qualities of fluidity, leakage, and flow that distinguish uncontained liquids also characterise globalisation, which encompasses a range of global trends and processes no longer confined to, or controlled by, the ‘container’ of the nation or state. The concept of liquid modernity helps to explain the conditions under which globalisation discourses have found a purchase and, by extension, the world in which contemporary children’s literature, media, and culture are produced. Perhaps more significantly, it points to the fluid conceptions of self and other that inform the ‘liquid’ worldview of the current generation of consumers of texts for children and young adults. This generation is growing up under the phase of globalisation we describe in this chapter.

Youth theatre and the articulation of cultural capital : refocusing Bourdieu through ethnography

This study of working-class and middle-class youth theatre workshops examines the processes through which this cultural form is appropriated by different class groups. Whereas the middle-class workshop proceeded efficiently and harmoniously, the working-class group resisted a number of institutional constraints traditionally associated with play rehearsal and performance. The processes of such symbolic struggle in the working-class group appeared to differ from Bourdieu's account of cultural domination. The article explores the explanatory contribution of the ethnographic case study to the analysis of the class basis of cultural tastes and practices and suggest that Bourdieu's account of class relations would gain from inclusion of this level of analysis. The situated study of the youth theatre workshops suggests that at this level, there is possibly more scope for symbolic struggle between the classes than was found by Bourdieu.

Re-Presenting/Representing Melbourne: A literary and cultural analysis of Melbourne’s inner city and outer suburbs in contemporary fiction

This article provides an overview of a research project investigating contemporary literary representations of Melbourne’s inner and outer suburban spaces. It will argue that the city represented by local writers is an often more complex way of envisioning the city than the one presented in public policy and cultural discourses. In this view, the writer’s vision of a city does not necessarily override or provide a “truer’ account but it is in the fictional city where the complexity of the everyday life of a city is most accurately portrayed. The article will also provide an overview of the theoretical framework for reading the fictional texts in this way, examining how Soja’s concept of Thirdspace (2006) provides a place to engage “critically with theoretical issues, while simultaneously being that space where the debate occurs” (Mole 2008: 3).

An evaluation of alternative media for pebble matrix filtration using clay balls and recycled crushed glass

Protecting slow sand filters (SSFs) from high-turbidity waters by pretreatment using pebble matrix filtration (PMF) has previously been studied in the laboratory at University College London, followed by pilot field trials in Papua New Guinea and Serbia. The first full-scale PMF plant was completed at a water-treatment plant in Sri Lanka in 2008, and during its construction, problems were encountered in sourcing the required size of pebbles and sand as filter media. Because sourcing of uniform-sized pebbles may be problematic in many countries, the performance of alternative media has been investigated for the sustainability of the PMF system. Hand-formed clay balls made at a 100-yearold brick factory in the United Kingdom appear to have satisfied the role of pebbles, and a laboratory filter column was operated by using these clay balls together with recycled crushed glass as an alternative to sand media in the PMF. Results showed that in countries where uniform-sized pebbles are difficult to obtain, clay balls are an effective and feasible alternative to natural pebbles. Also, recycled crushed glass performed as well as or better than silica sand as an alternative fine media in the clarification process, although cleaning by drainage was more effective with sand media. In the tested filtration velocity range of ð0:72–1:33Þ m=h and inlet turbidity range of (78–589) NTU, both sand and glass produced above 95% removal efficiencies. The head loss development during clogging was about 30% higher in sand than in glass media.

The cultural and creative industries

A critical and Historical account of the cultural and creative industries as a policy discourse. It argues that the emergence of a cultural policy discourse was part of a progressive democratic politics from the 1960s onwards, taking cognizance of the emergence of new kinds of commercial popular culture. It suggests that this period saw the merging of aesthetics and culture in particular ways. The creative industries come from a different source which combined innovation theory, embedded economics and entrepreneurialism in ways that resulted in a much less progressive politics. The chapter ends by suggesting the the idea of the creative industries is now at an end.

The cultural and creative industries : a literature review [2nd ed.]

This is a short book which gives an introduction and overview of the literature on the cultural and creative industries. This is a revised version of the 2007 edition, with a new conclusion.