Polycaprolactone scaffold and reduced rhBMP-7 dose for the regeneration of critical-sized defects in sheep tibiae

The transplantation of autologous bone graft as a treatment for large bone defects has the limitation of harvesting co-morbidity and limited availability. This drives the orthopaedic research community to develop bone graft substitutes. Routinely, supra-physiological doses of bone morphogenetic proteins (BMPs) are applied perpetuating concerns over undesired side effects and cost of BMPs. We therefore aimed to design a composite scaffold that allows maintenance of protein bioactivity and enhances growth factor retention at the implantation site. Critical-sized defects in sheep tibiae were treated with the autograft and with two dosages of rhBMP-7, 3.5 mg and 1.75 mg, embedded in a slowly degradable medical grade poly(ε-caprolactone) (PCL) scaffold with β-tricalcium phosphate microparticles (mPCL-TCP). Specimens were characterised by biomechanical testing, microcomputed tomography and histology. Bridging was observed within 3 months for the autograft and both rhBMP-7 treatments. No significant difference was observed between the low and high rhBMP-7 dosages or between any of the rhBMP-7 groups and autograft implantation. Scaffolds alone did not induce comparable levels of bone formation compared to the autograft and rhBMP-7 groups. In summary, the mPCL-TCP scaffold with the lower rhBMP-7 dose led to equivalent results to autograft transplantation or the high BMP dosage. Our data suggest a promising clinical future for BMP application in scaffold-based bone tissue engineering, lowering and optimising the amount of required BMP.

Elemental composition and potential toxicity of airborne particles at some urban schools

Although both the size and chemical composition of ambient particles are important parameters in determining their toxicities, their relative contributions are unclear (Heal et al., 2012). Children are particularly at risk to the detrimental health effects that have been linked to long term exposure to airborne particles (See e.g. Ruckerl et al., 2011). However, there is currently limited understanding of the health effects in children due to long term exposure to airborne particles. Schools are locations within an urban environment where children experience significant exposure to vehicle emissions, and to date there is limited information assessing children’s exposure at school. This study is a part of a large project aimed at gaining a holistic picture of the exposure of children to traffic related pollutants. In the current paper, results from the investigation of the elemental composition of airborne particle at urban schools are presented.

Revascularization and tissue regeneration of an empty root canal space is enhanced by a direct blood supply and stem cells

Background Regenerative endodontics is an innovative treatment concept aiming to regenerate pulp, dentin and root structures. In the diseased or necrotic tooth, the limitation in vascular supply renders successful tissue regeneration/generation in a whole tooth challenging. The aim of this study is to evaluate the ability of vascularized tissue to develop within a pulpless tooth using tissue engineering techniques. Materials and methods A pulpless tooth chamber, filled with collagen I gel containing isolated rat dental pulp cells (DPC) and angiogenic growth factors, was placed into a hole created in the femoral cortex or into its own tooth socket, respectively. The gross, histological and biochemical characteristics of the de novo tissue were evaluated at 4 and 8weeks post-transplantation. Results Tooth revascularization and tissue generation was observed only in the femur group, confirming the important role of vascular supply in tissue regeneration. The addition of cells and growth factors significantly promoted connective tissue production in the tooth chamber. Conclusion Successful revascularization and tissue regeneration in this model demonstrate the importance of a direct vascular supply and the advantages of a stem cell approach. © 2012 John Wiley & Sons A/S.

Using communicative ecology theory to scope the emerging role of social media in the evolution of urban food systems

Urban agriculture plays an increasingly vital role in supplying food to urban populations. Changes in Information and Communications Technology (ICT) are already driving widespread change in diverse food-related industries such as retail, hospitality and marketing. It is reasonable to suspect that the fields of ubiquitous technology, urban informatics and social media equally have a lot to offer the evolution of core urban food systems. We use communicative ecology theory to describe emerging innovations in urban food systems according to their technical, discursive and social components. We conclude that social media in particular accentuate fundamental social interconnections normally effaced by conventional industrialised approaches to food production and consumption.

Personal media and wireless cities : towards an urban spatial analysis

For the past decade, at least, varieties of small, hand held networked instruments have appeared on the global scene, selling in record numbers, and being utilized by all manner of persons from the old to the young; children, women, men, the wealthy and the poor and in all countries. Their presences bespeak a radical shift in telecommunications infrastructure and the future of communications. They are particularly visible in urban areas where mobile transmission network infrastructure (3G, 4G, cellular and Wi-Fi) is more established and substantial, options more plentiful, and density of populations more dramatic. These end user products—I phones, cell phones, Blackberries, DSi, DS, IPads, Zooms, and others – of the mobile communications industry are the latest, hottest globalized commodities. At the same time, wirelessness, or the state of being wireless, and therefore capable of taking along one's networks, communicating from unlikely spaces, and navigating with GPS, is a complex social, political and economic communications phenomenon of early 21st century life. This thesis examines the specter of being wireless in cities. It lends the entire idea an experimentally envisioned, historical and planned context wherein personalization of media tools is seen both as a design development of corporate, artistic, and military imagination, as well as a profound social phenomenon enabling new forms of sharing, belonging, and urban community. In doing that it asserts the parameters of a new mobile space which, aside from clear benefits to humankind by way of mobility, has reinscribed numerous categories including gender. Moreover, it posits the recognition of other, more nuanced theoretical spaces for complex readings of gender and gendered use, including some instantiation of the notion of 'network' itself as a cyborgian and gendered social form. Additionally, cities are studied as places where technology is not only quickly popularized, but is connected to larger political interests, such as the reading of data, tracking of information, and the new security culture. In so doing the work has been undertaken as an urban spatial analysis and experimental ethnography, utilizing architectural, feminist, techno-utopian, industrial and theoretical literatures as discursive underpinnings from whence understandings and interpretations of mobile space, the mobile office, networked mobility, and personal media have come, linking the space of cities to specific, pioneering urban public art projects in which voice, texting and MMS have been utilized in expressions of ubiquitous networks and urban history. Through numerous examples of techno art, the thesis discusses the 'wireless city' as an emerging cultural, socially constructed economic and spatial entity, both conceived and formed through historic processes of urbanization.

Innovating urban policymaking and planning mechanisms to deliver knowledge-based agendas : a methodological approach

This paper aims to develop a comprehensive approach to innovate urban policymaking and planning to successfully deliver the knowledge-based agenda. The paper, first, examines the concept of knowledge-based urban development, which has become a popular urban development policy and strategy in recent years, through a comprehensive review of the literature. It, then, introduces and discusses a novel methodological approach for effective policymaking and planning mechanism to deliver the knowledge-based agenda of cities. The paper, with the proposed methodology, brings together urban policymaking and planning approaches, and introduces a novel way to assess knowledge-based urban development achievements and potentials of emerging and prosperous knowledge cities. The paper, thus, provides an invaluable instrument to inform local and regional decision and plan making mechanisms to deliver their knowledge-based agendas and help them in moving towards building their sustainable knowledge cities.

Partitioning of dioxins (PCDDs/Fs) in ambient air at urban residential locations

In this work, 17-polychlorinated dibenzo-pdioxin/furan (PCDD/Fs) isomers were measured in ambient air at four urban sites in Seoul, Korea (from February to June 2009). The concentrations of their summed values RPCDD/Fs) across all four sites ranged from 1,947 (271 WHO05 TEQ) (Jong Ro) to 2,600 (349 WHO05 TEQ) fg/m3 (Yang Jae) with a mean of 2,125 ± 317) fg/m3 (292 WHO05 TEQ fg/m3). The sum values for the two isomer groups of RPCDD and RPCDF were 527 (30 WHO05 TEQ) and 1,598 (263 WHO05 TEQ) fg/m3, respectively. The concentration profile of individual species was dominated by the 2,3,4,7,8-PeCDF isomer, which contributed approximately 36 % of the RPCDD/Fs value. The observed temporal trends in PCDD/F concentrations were characterized by relative enhancement in the winter and spring. The relative contribution of different sources, when assessed by principal component analysis, is explained by the dominance of vehicular emissions along with coal (or gas) burning as the key source of ambient PCDD/Fs in the residential areas studied.

Differences in physical activity between black and white girls living in rural and urban areas

This study examined the relationship of race and rural/urban setting to physical, behavioral, psychosocial, and environmental factors associated with physical activity. Subjects included 1,668 eighth-grade girls from 31 middle schools: 933 from urban settings, and 735 from rural settings. Forty-six percent of urban girls and 59% of rural girls were Black. One-way and two-way ANOVAs with school as a covariate were used to analyze the data. Results indicated that most differences were associated with race rather than setting. Black girls were less active than White girls, reporting significantly fewer 30-minute blocks of both vigorous and moderate-to-vigorous physical activity. Black girls also spent more time watching television, and had higher BMIs and greater prevalence of overweight than White girls. However, enjoyment of physical education and family involvement in physical activity were greater among Black girls titan White girls. Rural White girls and urban Black girls had more favorable attitudes toward physical activity. Access to sports equipment, perceived safety of neighborhood, and physical activity self-efficacy were higher in White girls than Black girls.

Risk mitigation of post-earthquake fire in urban buildings

Post-earthquake fire (PEF) is considered one of the most high risk and complicated problems affecting buildings in urban areas and can cause even more damage than the earthquake itself. However, most standards and codes ignore the implications of PEF and so buildings are not normally designed with PEF in mind. What is needed is for PEF factors to be routinely scrutinized and codified as part of the design process. A systematic application is presented as a means of mitigating the risk of PEF in urban buildings. This covers both existing buildings, in terms of retrofit solutions, and those yet to be designed, where a PEF factor is proposed. To ensure the mitigation strategy meets the defined criteria, a minimum time is defined – the safety guaranteed time target – where the safety of the inhabitants in a building is guaranteed.

Urban knowledge and innovation spaces : concepts, conditions, and contexts

Innovation is one of the key determinants of growth in the globalised knowledge economy, and ‘urban knowledge and innovation spaces’ form the spatial foci for sustained innovation. This paper aims to explore concepts, conditions and contexts that substantiate the development of these spaces of innovation. The paper seeks to identify the foundational elements of knowledge- based urban development to outline the concept of urban knowledge and innovation spaces, and justify its meaning, unique characteristics and growing influence in the contemporary cities. It rationalises the relevance of the three underlying conditions—namely policy, place, and people— to better understand their contribution in the development of such spaces. This paper sheds light over the varied contexts shaping each urban knowledge and innovation space uniquely. The paper reveals the interplay between design and policies that is required for the creation of spaces of innovation that are economically strong, socially connected, spatially stimulating, and environmentally sustainable.

Knowledge Based Urban Development

The changing and challenging conditions of the 21st century have been significantly impacting our economy, society and built and natural environments. Today generation of knowledge—mostly in the form of technology and innovation—is seen as a panacea for the adaptation to changes and management of challenges (Yigitcanlar, 2010a). Making space and place that concentrate on knowledge generation, thus, has become a priority for many nations (van Winden, 2010). Along with this movement, concepts like knowledge cities and knowledge precincts are coined as places where citizenship undertakes a deliberate and systematic initiative for founding its development on the identification and sustainable balance of its shared value system, and bases its ability to create wealth on its capacity to generate and leverage its knowledge capabilities (Carrillo, 2006; Yigitcanlar, 2008a). In recent years, the term knowledge precinct (Hu & Chang, 2005) in its most contemporary interpretation evolved into knowledge community precinct (KCP). KCP is a mixed-use post-modern urban setting—e.g., flexible, decontextualized, enclaved, fragmented—including a critical mass of knowledge enterprises and advanced networked infrastructures, developed with the aim of collecting the benefits of blurring the boundaries of living, shopping, recreation and working facilities of knowledge workers and their families. KCPs are the critical building blocks of knowledge cities, and thus, building successful KCPs significantly contributes to the formation of prosperous knowledge cities. In the literature this type of development—a place containing economic prosperity, environmental sustainability, just socio‐spatial order and good governance—is referred as knowledge-based urban development (KBUD). This chapter aims to provide a conceptual understanding on KBUD and its contribution to the building of KCPs that supports the formation of prosperous knowledge cities.

Contemporary public spaces in urban knowledge precincts : observations from Brisbane, Australia

The advanced era of knowledge-based urban development has led to an unprecedented increase in mobility of people and the subsequent growth in the new typology of agglomerated enclaves of knowledge such as urban knowledge precincts. A new role has been assigned to contemporary public spaces of these precincts to attract and retain the mobile knowledge workforce for long by creating a sense of place for them. This paper sheds light over the place making in the globalised knowledge economy world which develops a sense of permanence spatio-temporally to knowledge workers displaying a set of particular characteristics and simultaneously is process-dependent getting developed by the internal and external flows and contributing substantially in the development of the broader context it stands in relation with. The paper highlights the observations from Australia’s new world city Brisbane to outline the application of urban design as a tool to create and sustain this bipartite place making in urban knowledge precincts, which caters diverse range of social, cultural and democratic needs. It seeks to analyse the modified permeable typology of public spaces that makes it more viable and adaptive as per the changing needs of the contemporary globalised or in other words knowledge society. This research has taken an overall process-based approach reflecting how urban design is an assemblage of the encompassing processes that underlay the resultant place making. It explores how the permeable design typology of these contemporary precincts in Brisbane develops a progressive sense of place that makes them stimulating, effervescent and vibrant.

Observations on the formation, growth and chemical composition of aerosols in an urban environment

The charge and chemical composition of ambient particles in an urban environment were determined using a Neutral Particle and Air Ion Spectrometer and an Aerodyne compact Time-Of-Flight Aerosol Mass Spectrometer. Particle formation and growth events were observed on 20 of the 36 days of sampling, with eight of these events classified as strong. During these events, peaks in the concentration of intermediate and large ions were followed by peaks in the concentration of ammonium and sulphate, which were not observed in the organic fraction. Comparison of days with and without particle formation events revealed that ammonium and sulphate were the dominant species on particle formation days while high concentrations of biomass burning OA inhibited particle growth. Analyses of the degree of particle neutralisation lead us to conclude that an excess of ammonium enabled particle formation and growth. In addition, the large ion concentration increased sharply during particle growth, suggesting that during nucleation the neutral gaseous species ammonia and sulphuric acid react to form ammonium and sulphate ions. Overall, we conclude that the mechanism of particle formation and growth involved ammonia and sulphuric acid, with limited input from organics.

Relating urban airborne particle concentrations to shipping using carbon based elemental emission ratios

This study demonstrates a novel method for testing the hypothesis that variations in primary and secondary particle number concentration (PNC) in urban air are related to residual fuel oil combustion at a coastal port lying 30 km upwind, by examining the correlation between PNC and airborne particle composition signatures chosen for their sensitivity to the elemental contaminants present in residual fuel oil. Residual fuel oil combustion indicators were chosen by comparing the sensitivity of a range of concentration ratios to airborne emissions originating from the port. The most responsive were combinations of vanadium and sulfur concentration ([S], [V]) expressed as ratios with respect to black carbon concentration ([BC]). These correlated significantly with ship activity at the port and with the fraction of time during which the wind blew from the port. The average [V] when the wind was predominantly from the port was 0.52 ng.m-3 (87%) higher than the average for all wind directions and 0.83 ng.m-3 (280%) higher than that for the lowest vanadium yielding wind direction considered to approximate the natural background. Shipping was found to be the main source of V impacting urban air quality in Brisbane. However, contrary to the stated hypothesis, increases in PNC related measures did not correlate with ship emission indicators or ship traffic. Hence at this site ship emissions were not found to be a major contributor to PNC compared to other fossil fuel combustion sources such as road traffic, airport and refinery emissions.

Urban Informatics and Public Transport

The holistic urban experience we perceive when immersed in an urban context is at the heart of urban informatics. This experience encompasses all urban elements such as architecture, people, and culture. Urban informatics explores the possibilities and opportunities created by new technologies and information for enhancing the urban experience. Public transport is an essential urban experience. Everyday, urban dwellers takes public transport to commute and move between different parts of the city. Public transport serves people from all over the city and moves them through different places in the city, using different means of transportation. The nature of public transport—involving people, places, and technologies, makes it a fitting context for urban informatics interventions. There are three main aspects of the public transport experience that can readily benefit from urban informatics interventions the: pragmatic aspect, hedonistic aspect, and social aspect. From the pragmatic perspective, these interventions can help people to be more efficient and effective in taking public transport. Hedonistic-related interventions aim to bring enjoyment and fun to our mundane commute. Finally, urban informatics can strengthen the sense of community in a socially-passive context like public transport environments through adopting socially focused interventions.