pH-detachable polymer brushes formed using titanium−diol coordination chemistry and living radical polymerization (RAFT)

pH-detachable poly(styrene) brushes formed on indium−tin oxide (ITO) glass substrates using metal complex chemistry and reversible addition−fragmentation chain transfer (RAFT) polymerization was described. These pH-detachable polymeric brushes were generated using both “graft-from” and “graft-to” methodologies. The methodologies involved either the surface self-assembly of catechol-functional RAFT agents (graft-from) or catechol-terminal polymer chains (graft-to) onto the ITO substrate via titanium−diol coordination. The stepwise functionalization of the ITO glass surfaces was characterized successfully using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Poly(styrene) brushes generated using the “graft-from” method were denser than those generated using the “graft-to” method, as exemplified by atom force microscopy (AFM) and quantified using cyclic voltammetry. Poly(styrene) brushes assembled using both methods could be detached easily by manipulating the pH of the brush environment. Cyclic voltammetry was utilized to calculate precisely the surface coverage of the RAFT functionality and polymeric brush density.

The raft-promoting property of virion-associated cholesterol, but not the presence of virion-associated brij 98 rafts, is a determinant of human immunodeficiency virus type 1 infectivity

Lipid rafts are enriched in cholesterol and sphingomyelin and are isolated on the basis of insolubility in detergents, such as Brij 98 and Triton X-100. Recent work by Holm et al. has shown that rafts insoluble in Brig 98 can be found in human immunodeficiency virus type 1 (HIV-1) virus-like particles, although it is not known whether raft-like structures are present in authentic HIV-1 and it is unclear whether a virion-associated raft-like structure is required for HIV replication. Independently, it was previously reported that virion-associated cholesterol is critical for HIV-1 infectivity, although the specific requirement of virion cholesterol in HIV-1 was not examined. In the present study, we have demonstrated that infectious wild-type HIV-1 contains Brij 98 rafts but only minimal amounts of Triton X-100 rafts. To directly assess the functional requirement of virion-associated rafts and various features of cholesterol on HIV-1 replication, we replaced virion cholesterol with exogenous cholesterol analogues that have demonstrated either raft-promoting or -inhibiting capacity in model membranes. We observed that variable concentrations of exogenous analogues are required to replace a defined amount of virion-associated cholesterol, showing that structurally diverse cholesterol analogues have various affinities toward HIV-1. We found that replacement of 50% of virion cholesterol with these exogenous cholesterol analogues did not eliminate the presence of Brij 98 rafts in HIV-1. However, the infectivity levels of the lipid-modified HIV-1s directly correlate with the raft-promoting capacities of these cholesterol analogues. Our data provide the first direct assessment of virion-associated Brij 98 rafts in retroviral replication and illustrate the importance of the raft-promoting property of virion-associated cholesterol in HIV-1 replication.

RAFT controlled synthesis of graphene/polymer hydrogel with enhanced mechanical property for pH-controlled drug release

A pH-sensitive, mechanically strong and thermally stable graphene/poly (acrylic acid) (graphene/PAA) hydrogel was prepared via reversible addition fragmentation transfer (RAFT) polymerizations in the presence of a cross-linking agent. The RAFT agent was covalently coupled onto graphene basal planes via an esterification reaction, with benzoic acid functionalities pre-attached on graphene with its aryl diazonium salt precursor. AFM and SEM analysis revealed the successful preparation of single layered graphene sheets and graphene/polymer hydrogels with pH controlled porous structures. Attenuated total reflection infrared (ATR-IR) and thermogravimetric analyzer (TGA) verified the successful stepwise preparation of graphene/PAA hydrogel. This graphene/PAA hydrogel was pH-sensitive and more mechanically elastic than the PAA hydrogel prepared without graphene. The pH sensitivity of the hydrogel was further utilized for controlled drug release. Doxorubicin was chosen as a model drug and loaded into the hydrogels. The drug loading and release experiment indicated that this hydrogel can be used to efficiently control drug release in the intestine environment (pH = 7.4), better than release in a more acidic environment.© 2013 Elsevier Ltd. All rights reserved.

Graphene/tri-block copolymer composites prepared via RAFT polymerizations for dual controlled drug delivery via pH stimulation and biodegradation

A novel tri-block copolymer poly(oxopentanoate ethyl methacrylate)-block-poly(pyridyl disulfide ethyl acrylate)-block-poly(ethylene glycol acrylate) [poly(OEMA-b-PDEA-b-PEGA)], retaining active keto groups and pyridyl disulfide (PDS) side functionalities, was synthesized as a drug delivery vehicle using reversible addition-fragmentation chain transfer (RAFT) polymerization method. One mimic drug pyridine-2-thione (PT) was introduced into the monomer, PDEA for copolymerization. The other mimic drug O-benzylhydroxylamine (BHA) was conjugated with tri-block copolymer via efficient oxime coupling chemistry, followed by the attachment onto graphene via π-π stacking interaction to obtain a graphene/tri-block copolymer composite. 1H NMR, UV-vis absorption spectroscopy, fluorescence spectroscopy, gel permeation chromatography (GPC), atomic force microscope (AFM) and transmission electron microscope (TEM) were used to verify the successful step-wise preparation of the tri-block copolymer and drug loaded composite. In vitro release behaviors of BHA and PT from graphene/tri-block copolymer composite via dual drug release mechanisms were investigated. BHA can be released under acid environment, while PT will be released in the presence of reducing agents, such as dithiothreitol (DTT) or glutathione (GSH). It can be envisioned that this novel composite could be exploited as a novel intracellular drug delivery system via dual release mechanisms.

Properties of HIV-1 associated cholesterol in addition to raft formation are important for virus infection

The overall HIV-1 membrane lipid contents resemble lipid rafts, and we have previously demonstrated that raft-promoting properties of virus-associated cholesterol (with modifications in either the 3β-OH group or AB rings) are important for HIV-1 infectivity. As cholesterol is present in both rafts and non-rafts domains of HIV-1 membrane, we question whether the interpretation of rafts property of virus-associated cholesterol being an absolute requirement for HIV-1 function is too simplistic. The carbon side chain of cholesterol is the third component of cholesterol that can affect the fluidity of membrane depending on its context within the lipid membrane bilayers. In this work, we have used synthetic cholesterol analogues that have different lengths of carbon side chain for our investigation. In contrast to our previous report, we have found that cholesterol side chain analogues that lack in vitro defined raft promoting-property is able to support HIV-1 replication. More specifically, cholesterol analogues with side chains of intermediate length have greater capacity to support HIV-1 infection, suggesting HIV-1 is able to maintain function using cholesterol variants that promote a range of non-rafts- to rafts-properties. Our data demonstrate cholesterol properties other than raft-promoting function also contribute to the infectivity of HIV-1.

Growing Up as Risky Business? Risks, Surveillance and the Institutionalized Mistrust of Youth

This paper will argue that a major problem for young people today is that they increasingly cause adults anxiety. This anxiety translates into a raft of interventions and strategies and programmes that target young people. These imaginings reflect and constitute a range of anxieties about the dangers posed by some young people, or to some young people, and how these risks might be economically and prudently managed. These institutionalized relationships of mistrust can have a range of often negative consequences (intended or otherwise) for individuals and populations of young people. I argue that Foucault's work on disciplinary, sovereign and governmental forms of power provides a generative framework for analysing what I refer to as the institutionalized mistrust, surveillance and regulation of contemporary populations of young people.

The use of codes of ethics in the marketplace in corporate Australia : a longitudinal study

The stock market crash of 1987 was a defining moment in Australian corporate life. As a nation, we became acutely aware of the ‘moral bankruptcy’ that had come to permeate our corporate world. The focus on business ethics or the lack of it, in corporate Australia in the late 1980s, prompted this research.

The research for this paper that was first conducted in 1995 and replicated in 2001 focussed on the top 500 companies in Australia. These companies were surveyed on a raft of issues, one of which was their use of their codes of ethics in the marketplace. This paper examines the data sets from 1995 and 2001 and concludes that many of Australia’s largest enterprises have recognised the need for business ethics. As perceived by them, they can and do use their codes of ethics in a positive manner in the marketplace and attribute benefits to this interaction.

Sulfatide-tenascin interaction mediates binding to the extracellular matrix and endocytic uptake of liposomes in glioma cells

Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery. We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future.

Characterization of a distinct plasma membrane macrodomain in differentiated adipocytes.

Caveolae are small invaginations of the cell surface that are abundant in mature adipocytes. A recent study (Kanzaki, M., and Pessin, J. E. (2002) J. Biol. Chem. 277, 25867-25869) described novel caveolin- and actin-containing structures associated with the adipocyte cell surface that contain specific signaling proteins. We have characterized these structures, here termed "caves," using light and electron microscopy and observe that they represent surface-connected wide invaginations of the basal plasma membrane that are sometimes many micrometers in diameter. Rather than simply a caveolar domain, these structures contain all elements of the plasma membrane including clathrin-coated pits, lipid raft markers, and non-raft markers. GLUT4 is recruited to caves in response to insulin stimulation. Caves can occupy a significant proportion of the plasma membrane area and are surrounded by cortical actin. Caveolae density in caves is similar to that on the bulk plasma membrane, but because these structures protrude much deeper into the plane of focus of the light microscope molecules such as caveolin and other plasma membrane proteins appear more concentrated in caves. We conclude that the adipocyte surface membrane contains numerous wide invaginations that do not represent novel caveolar structures but rather large surface caves.

Health promotion and evaluation - a programmatic approach

Health promotion has evolved significantly in the past twenty years. Its emphasis has shifted from relatively simple monocausal models focused on behavioural risk factors to a greater emphasis on broader social determinants of health. Single method, single risk factor interventions have increasingly been replaced with multiformat, multiple risk factor interventions and extended campaigns, with whole-of-govemment implications. Health promotion structures have developed from ad hoc single shot activity to large dedicated agencies with continuing responsibilities and a wide ambit.

The development of health promotion research and evaluation has followed these trends. The early epidemiology studies linked behavioural risks such as smoking, diet and physical activity with systemic conditions such as cancer and cardiovascular disease. A raft of small and large scale intervention studies aimed at demonstrating that these behavioural risk factors could be modified and that modification would lead to improved health outcomes followed with mixed results.

More recent evidence suggests that behavioural risks are not the onIy social factors that influence health outcomes. There is now strong evidence that social determinants such as income, education and employment have highly significant direct effects on health outcomes, which are not mediated by behavioural risks, and that behavioural risks are also correlated with these broader determinants.

Health promotion now operates in a variety of ways at different scales and different levels of the health system (and the wider social system). The goals of health promotion, and the measures that assess whether a project, campaign, or general strategy has met its goals, differ accordingly.

Arguably, where local, state and federal governments begin to coordinate their efforts systematically across settings, intervention strategies, health action areas and population groups, health promotion becomes more
programmatic, sustainable and effective. A programmatic approach also integrates knowledge generation, the development of health promotion capacity, practice and evaluation together.

However, programmatic approaches to health promotion are comparatively new. Only recently have governments begun to develop and resource
comprehensive and sustained health promotion programs that address a range of health issues using multiple intervention strategies. The scope of a more programmatic approach and its functions and purposes is still developing.

Although evaluation has a key role to play in this respect, the development of programmatic strategies for health promotion has generally outpaced evaluation theory and practice. While we now have reasonable technologies for measurement of behavioural risks and individual attitudinal and cognitive influences on them, strategies to evaluate organisational and community interventions are still emerging.

Similarly, while new approaches to evaluate small scale community and organisational interventions have been developed, comprehensive models to monitor and evaluate health promotion programs and strategies across multiple intervention sites over extended periods have not yet emerged. Nor have we resolved the methodological problems of teasing out the relative contribution of different intervention strategies to observed change in health outcomes.

More programmatic approaches to health promotion require a more programmatic approach to health promotion evaluation. This paper represents an issues based examination of the evidence base for a more programmatic health promotion and the evaluation issues that arise

Rogue men and predatory women : female fan's perception of Australian footballers' sexual conduct

The 2004 Australian Football League and National Rugby League seasons started amidst claims made by women about players behaving inappropriately towards them. A raft of allegations surfaced in the media, prompting nationwide debate on the issue of sportsmen and violence. While sport sociologists have made important inroads toward understanding sexual misconduct by male athletes, much of this research appears to focus on the socio-cultural factors informing the perpetrators' actions. This study takes a different approach, analysing the perspectives of female Australian rules football fans to consider gendered narratives of sexual misconduct. Our findings demonstrate that discourses of individualism, along with a mix of socio-cultural and biological arguments, are used by women to reconcile players' misconduct with continuing support of their sport.

Constructing inclusive education in a neo-liberal context : promoting inclusion of Arab-Australian students in an Australian context

School systems are a major social change agent capable of challenging social inequalities and economic disadvantages. Yet, while schools in Australia are being confronted with increasingly culturally diverse populations as well as an increasing focus on student retention, this transformative role is increasingly being played out in a broader educational context that has been found to replicate rather than challenge patterns of social inequality. Successive governments in Australia have responded to this context with a raft of policy initiatives. This paper, based on three-year longitudinal research undertaken in the city of Melbourne, outlines this policy context and introduces the theoretical approach that underpins its innovative approach to managing cultural diversity in educational institutions. It argues for, and presents, a multidimensional model for managing cultural diversity in schools, one that provides the tools for transformative practices to be undertaken to effect positive change in school environments for the benefit of all students.

Re-framing the riot : journalism, creative non-fiction and telling the story of Australia's black history

On 19 November 2004, an Aboriginal man was arrested on Palm Island, off the coast of Townsville in northern Queensland. He was taken to the local watch house on a drunk and disorderly charge. An hour later, he lay dead on a cell floor. His liver, an autopsy showed, had been split in half and his spleen ruptured. But when that autopsy report also found that Mulrunji Doomadgee’s severe injuries were not caused by force, the Palm Island Indigenous community, enraged and grief-stricken, went looking for payback.

The Palm Island “riots” ensured that this Aboriginal death in custody made international news headlines where others barely got a mention, if at all (Hollinsworth, 2005). The ensuing Coronial Inquest and criminal prosecution of the arresting Queensland police officer, Chris Hurley, also were covered consistently by the news media. Senior Sergeant Hurley has, however, so far escaped punishment and the Queensland media’s most recent report of the case was to tell how the Qld Police Union now funds a legal bid to clear his name. Meanwhile, little is heard in the news media of the Doomadgee family, the Palm Island community, or of other deaths in custody occurring steadily through the 18 years since the Royal Commission that was supposed to implement a raft of preventative recommendations.

While the news media’s framing of these issues has most often followed historically predictable and ultimately racist lines, a work of creative non-fiction tells the story with warranted complexity and power. Chloe Hooper’s The Tall Man: Death and Life on Palm Island documents Cameron Doomadgee’s death, the riots, and the ensuing legal farce from the front row. Hooper, in the tradition of Truman Capote, arrived at Palm Island as a white writer from a big city. But by “walking the talk” – being with the Doomadgee family and their community through the hearings and after, Hooper was given extraordinary access to community, history, and significant cultural nuance barely identified by, let alone understood by, non-Indigenous readers.

By focussing on Hooper’s experience with sources and court reporting, compared with some print media coverage, this paper will consider the comparative roles of journalism and creative non-fiction in re-framing the Palm Island “riot”. It will suggest that Hooper’s work subverts some dominant (and racist) news media representations of Australian Indigenous peoples through its use of source relationships in an extended narrative structure.