Effects of the architecture of tissue engineering scaffolds on cell seeding and culturing

The advance of rapid prototyping techniques has significantly improved control over the pore network architecture of tissue engineering scaffolds. In this work we assessed the influence of scaffold pore architecture on cell seeding and static culturing, by comparing a computer‐designed gyroid architecture fabricated by stereolithography to a random‐pore architecture resulting from salt‐leaching. The scaffold types showed comparable porosity and pore size values, but the gyroid type showed a more than tenfold higher permeability due to the absence of size‐limiting pore interconnections. The higher permeability significantly improved the wetting properties of the hydrophobic scaffolds, and increased the settling speed of cells upon static seeding of immortalised mesenchymal stem cells. After dynamic seeding followed by 5 days of static culture, gyroid scaffolds showed large cell populations in the centre of the scaffold, while salt‐leached scaffolds were covered with a cell‐sheet on the outside and no cells were found in the scaffold centre. It was shown that interconnectivity of the pores and permeability of the scaffold prolongs the time of static culture before overgrowth of cells at the scaffold periphery occurs. Furthermore, novel scaffold designs are proposed to further improve the transport of oxygen and nutrients throughout the scaffolds, and to create tissue engineering grafts with designed, pre‐fabricated vasculature.

Immobilised anatase on clay mineral particles as a photocatalyst for herbicides degradation

Materials consisting of anatase linked to Laponite particles were synthesized by the reaction of TiOSO4 with Laponite, and were used for the degradation of pesticides. All these materials were characterized by XRD, FTIR, Raman, TEM, specific surface area and porosity determinations. Based on the amount of photoactive phase per unit mass of the clay mineral, not based on the total weight of the catalysts, these porous catalysts were displaying a high degradation rate than commercial P25. The TiO2 immobilized clay mineral catalysts can sediment in few minutes and could be readily separated out from a slurry system after the photocatalytic reaction. Settling properties of these catalysts are enormously high in aqueous media in contrast to P25.

Insights to the Clarification of Sugar Cane Juice Expressed from Sugar Cane Stalk and Trash

Processing of juice expressed from green sugar cane containing all the trash (i.e., tops and leaves, the nonstalk component) of the sugar cane plant during sugar manufacture has been reported to lead to poor clarified juice (CJ) quality. Studies of different liming techniques have been conducted to identify which liming technique gives the best clarification performance from juice expressed from green cane containing half of all trash extracted (GE). Results have shown that lime saccharate addition to juice at 76 °C either continuous or batchwise gives satisfactory settling rates of calcium phosphate flocs(50−70 cm/min) and CJ with low turbidity and minimal amounts of mineral constituents. Surprisingly, the addition of phosphoric acid (≤300 mg/kg as P2O5), prior to liming to reduce juice turbidity (≤80%), increased the Mg (≤101%) and Si(≤148%) contents particularly for clarified GE juices. The increase was not proportional with increasing phosphoric acid dose. The nature of the flocs formed, including the zeta potential of the particles by the different liming techniques, has been used to account for the differences in clarification performance. Differences between the qualities of the CJ obtained with GE juice and that of burnt cane juices with all trash extracted (BE) have been discussed to provide further insights into GE processing.

The Waitangi Tribunal and the regulation of Maori protest

Much of the current academic and political discourse related the development and operations of the Waitangi Tribunal over its first twenty years portray it as a forum that provided Māori with a meaningful avenue for settling Treaty grievances compared to the formal legal systems performance in the preceding 100 years. In contrast, we argue that from its inception and throughout much of the 1980s, the Waitangi Tribunal functioned primarily as an informal justice forum that assisted the New Zealand state’s regulation of Māori Treaty activism during the transition from a Fordist to a Post-Fordist mode of capital accumulation.

Anatomy of a submarine pyroclastic flow and associated turbidity current : July 2003 dome collapse, Soufrière Hills volcano, Montserrat, West Indies

The 12 to 13 July 2003 andesite lava dome collapse at the Soufrière Hills volcano, Montserrat, provides the first opportunity to document comprehensively both the sub-aerial and submarine sequence of events for an eruption. Numerous pyroclastic flows entered the ocean during the collapse, depositing approximately 90% of the total material into the submarine environment. During peak collapse conditions, as the main flow penetrated the air–ocean interface, phreatic explosions were observed and a surge cloud decoupled from the main flow body to travel 2 to 3 km over the ocean surface before settling. The bulk of the flow was submerged and rapidly mixed with sea water forming a water-saturated mass flow. Efficient sorting and physical differentiation occurred within the flow before initial deposition at 500 m water depth. The coarsest components (∼60% of the total volume) were deposited proximally from a dense granular flow, while the finer components (∼40%) were efficiently elutriated into the overlying part of the flow, which evolved into a far-reaching turbidity current.

Unpacking the micro-macro nexus: narratives of suffering and hope among refugees from Burma recently settled in Australia

Narratives of forced migration are open to a variety of interpretations. In mental health, refugee narratives of arduous journeys in the face of systemic macro socio-political forces are often transformed from this context into a medicalized micro context of inner individual worlds. Both the dominant pathogenic lens of trauma studies and the growing salutogenic lens embodied in resilience research, often reflect a western cultural idiom of focusing on the individualized nature of these phenomena. Using qualitative data collected from refugees from Burma now settling in Australia, the article emphasizes the need for a more reflexive and expansive account of both suffering and hope within refugee narratives. It recounts these narratives within a conceptual framework which acknowledges the importance of the connections between the micro individual experience and the macro, socio-political context. This is not only a question of political principle, but also a matter of listening to the voice of those who know most about the relationship between macro forces of human rights violations and their impact on individual, family and community trajectories.

Producing solidarity : a settlement strategy of the Karen refugee community in Brisbane, Australia

This paper explores the link between experience and context. It places the lived experiences of Karen refugees during settlement in Brisbane, Australia within the socio-political context of Burma, or particularly the historical context of persecution. Two key events – the Wrist-tying Ceremony and the Karen New Year – provide a link between experience and context. The findings of this study show a community strategically at work in a new and ongoing settlement process. This process pays respect to the complexities of cultural integrity whilst also engaging with the challenges of integration. The complexities are local (in terms of cultural, linguistic and religious diversity), national (maintaining a broader sense of community that includes linkages across Australia, as well as an engagement with the Australian socio-political context), and transnational (participating in a global Karen community). This transnational community encompasses Karen settling elsewhere in the world, Karen in refugee camps neighbouring Burma, and Karen living inside Burma. This paper argues that substantial “identity work” is involved in Karen settlement. The two key community events are useful vignettes of this identity work. Both events demonstrate how Karen cultural practices can meaningfully negotiate deeply historical ideas of Karen identity with contemporary challenges of settlement. In addition, they set out a version of settlement that departs from traditional settlement constructs; they show how the lived experience of settlement is messy, complex and dynamic, and not reflective of the neat, idealistic models that immigration policy and settlement theory project.

Understanding treatment characteristics of constructed stormwater wetlands

Constructed wetlands are a common structural treatment measure employed to remove stormwater pollutants and forms an important part of the Water Sensitive Urban Design (WSUD) treatment suite. In a constructed wetland, a range of processes such as settling, filtration, adsorption, and biological uptake play a role in stormwater treatment. Occurrence and effectiveness of these processes are variable and influenced by hydraulic, chemical and biological factors. The influence of hydraulic factors on treatment processes are of particular concern. This paper presents outcomes of a comprehensive study undertaken to define the treatment performance of a constructed wetland highlighting the influence of hydraulic factors. The study included field monitoring of a well established constructed wetland for quantity and quality factors, development of a conceptual hydraulic model to simulate water movement within the wetland and multivariate analysis of quantity and quality data to investigate correlations and to define linkages between treatment performance and influential hydraulic factors. Total Suspended Solids (TSS), Total Nitrogen (TN) and Total Phosphorus (TP) concentrations formed the primary pollutant parameters investigated in the data analysis. The outcomes of the analysis revealed significant reduction in event mean concentrations of all three pollutants species. Treatment performance of the wetland was significantly different for storm events above and below the prescribed design event. For events below design event, TSS and TN load reduction was comparatively high and strongly influenced by high retention time. For events above design event, TP load reduction was comparatively high and was found to be influenced by the characteristics of TP wash-off from catchment surfaces.

Surface sulfur measurements on stratospheric particles

The surface chemistries of three particulate samples collected from the lower stratosphere have been determined using a Scanning Auger Microprobe (SAM). These samples are typical of the most abundant natural and anthropogenic particles observed within the stratosphere in the >2µm diameter size fraction. Successive sputtering and analysis below the first few adsorbed monolayers of all particles shows the presence of a thin <150A) sulphur layer. These sulphur regions probably formed by surface reaction of sulphur-rich aerosols with each particle within the stratosphere. Settling rate calculations show that a typical sphere (10µm diameter) may reside within the aerosol layer for ~20 days and thus, provide a qualitative guide to surface sulphur reaction rates.

A pilot study exploring Australian general practice nurses roles, responsibilities and professional development needs in well and sick child care

Aim Explore practice nurses' (PNs) role in child health and development, and advising parents about child health issues. Background Introduction of the four-year-old child health check into general practice in 2008 placed additional responsibilities on PNs in child health and wellness. This study explores their readiness to expand their practice into this area. Design Integrated mixed method design, self-report survey. Method A purpose-developed questionnaire explored demographics, child health roles and responsibilities, difficulties encountered, professional development needs, barriers and facilitators, and professional development activities undertaken in the past year. Surveys were posted to 218 PNs in one rural Division of General Practice (DGP) in Queensland, Australia; 29 responded. Results PNs reported a significant role in well and sick child care (93.1%) though few had a paediatric/child health background (14.3%). Roles included immunisations (92.3%), child health checks (65.4%), general child health and development (26.9%), asthma (23.1%), feeding (15.4%), fever (11.5%), settling/sleeping (11.5%). PNs were interested in learning more about (81.5%) and incorporating more child health into their practice (81.5%). Professional development in childhood growth and development (80.0%), health and illness (60.0%) and advising new mothers (20.0%) was needed. Conclusions PNs play a substantial role in child health, are unprepared for the complexities of this role and have preferred methods for undertaking professional development to address knowledge deficits. Implications for practice PNs are unprepared for an advanced role in child health and wellness. Significant gaps in their knowledge to support this role were identified. This ever-expanding role requires close monitoring to ensure knowledge precedes expectations to practice.

Good Starts for recently arrived youth with refugee backgrounds : promoting wellbeing in the first three years of settlement in Melbourne, Australia

This report describes the key findings of a longitudinal study (2004—2008) investigating the experiences of settlement among a group of 120 recently arrived young people with refugee backgrounds settling in Melbourne, Australia. Each year, less than one per cent of the world’s refugees are offered resettlement in one of 18 countries participating in The Office of the United Nations High Commissioner for Refugees (UNHCR) resettlement programme. Australia offers places to around 13,500 people per year, of whom about 26 per cent are between the ages of 10 and 19. What are the experiences of these young people in their early settlement years? How do they negotiate the transition from childhood to adulthood given the traumas of their past and the challenges of their present and future in Australia? What are the key social determinants of wellbeing and good settlement and what can we learn from these young people about what social policies and services will most effectively support them to make successful lives in their new home? This study explores these questions, the overall aim being to identify the key social determinants of wellbeing and settlement and to describe the lived experiences of these young people as they shape their lives in Australia.

Analysis of construction dispute review boards

The construction industry has long been burdened with inherent adversarial relationships among the parties and the resulting disputes. Dispute review boards (DRBs) have emerged as alternatives to settle construction-related disputes outside courts. Although DRBs have found support in some quarters of the construction industry, the quantitative assessment of the impact of DRBs has not been adequately addressed. This paper presents the results of a research project undertaken to assess the impact of DRBs on the construction program of a large-scale highway agency. Three dimensions of DRB impact were assessed: (1) influence on project cost and schedule performance, (2) effectiveness of DRBs in preventing and resolving construction disputes, and (3) costs of DRB implementation. The analyses encompass data from approximately 3,000 projects extending over a 10-year period (2000–2009). Quantitative measures of performance were developed and analyzed for each category. Projects that used DRBs faced reduced costs and schedule growth (6.88 and 12.92%, respectively) when compared to non-DRB projects (11.53 and 28.96%). DRBs were also found to be effective in avoiding and settling disputes; the number of arbitration cases reduced consistently after DRB implementation, and DRBs have a success rate of 97% in settling disputes for which DRBs were used. Moreover, costs of DRBs were found to comprise a relatively small fraction (i.e., approximately 0.3%) of total project budgets. It was concluded that DRBs were effective dispute prevention and resolution alternatives with no significant adverse effects on project performance.

Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis

Background Person-to-person transmission of respiratory pathogens, including Pseudomonas aeruginosa, is a challenge facing many cystic fibrosis (CF) centres. Viable P aeruginosa are contained in aerosols produced during coughing, raising the possibility of airborne transmission. Methods Using purpose-built equipment, we measured viable P aeruginosa in cough aerosols at 1, 2 and 4 m from the subject (distance) and after allowing aerosols to age for 5, 15 and 45 min in a slowly rotating drum to minimise gravitational settling and inertial impaction (duration). Aerosol particles were captured and sized employing an Anderson Impactor and cultured using conventional microbiology. Sputum was also cultured and lung function and respiratory muscle strength measured. Results Nineteen patients with CF, mean age 25.8 (SD 9.2) years, chronically infected with P aeruginosa, and 10 healthy controls, 26.5 (8.7) years, participated. Viable P aeruginosa were detected in cough aerosols from all patients with CF, but not from controls; travelling 4 m in 17/18 (94%) and persisting for 45 min in 14/18 (78%) of the CF group. Marked inter-subject heterogeneity of P aeruginosa aerosol colony counts was seen and correlated strongly (r=0.73–0.90) with sputum bacterial loads. Modelling decay of viable P aeruginosa in a clinic room suggested that at the recommended ventilation rate of two air changes per hour almost 50 min were required for 90% to be removed after an infected patient left the room. Conclusions Viable P aeruginosa in cough aerosols travel further and last longer than recognised previously, providing additional evidence of airborne transmission between patients with CF.

Vagueness and software engineering

We do not commonly associate software engineering with philosophical debate. Indeed, software engineers ought to be concerned with building software systems and not settling philosophical questions. I attempt to show that software engineers do, in fact, take philosophical sides when designing software applications. In particular, I look at how the problem of vagueness arises in software engineering and argue that when software engineers solve it, they commit to philosophical views that they are seldom aware of. In the second part of the paper, I suggest a way of dealing with vague predicates without having to confront the problem of vagueness itself. The purpose of my paper is to highlight the currently prevalent disconnect between philosophy and software engineering. I claim that a better knowledge of the philosophical debate is important as it can have ramifications for crucial software design decisions. Better awareness of philosophical issues not only produces better software engineers, it also produces better engineered products.

Migrants, refugees and mobility : how useful are information communication technologies in the first phase of resettlement?

The rate at which people move and resettle around the world is unprecedented. Mobility and resettlement is now greatly assisted by the use of inexpensive internet communication technologies (ICTs) for a wide variety of functions: to communicate locally and across territories, for localised information seeking, geo – locational mapping and for forging new social connections in host countries and cities. This article is based on a qualitative study of newly arrived migrants and mobile people from non English speaking backgrounds (NESB) to the city of Brisbane, Australia and investigates how the internet is used to assist the initial period of settling into the city. As increasing amounts of essential information is placed online, the study asks how people from NESB communities manage to negotiate the types of information they require during the early stages of resettlement, given varying levels of access to ICTs, digital and language literacy. The study finds that the internet is widely used for specific location information seeking (such as accommodation and job-seeking), but this is often supplemented with other non-mediated sources of information. The study identified implications for social policy in regard to the resourcing and access of information. While findings are specific to the study location, it is feasible that the patterns of internet use for resettlement have relevance in a broader context.