A multicast routing scheme for efficient safety message dissemination in VANET

Vehicular ad hoc network (VANET) is a wireless ad hoc network that operates in a vehicular environment to provide communication between vehicles. VANET can be used by a diverse range of applications to improve road safety. Cooperative collision warning system (CCWS) is one of the safety applications that can provide situational awareness and warning to drivers by exchanging safety messages between cooperative vehicles. Currently, the routing strategies for safety message dissemination in CCWS are scoped broadcast. However, the broadcast schemes are not efficient as a warning message is sent to a large number of vehicles in the area, rather than only the endangered vehicles. They also cannot prioritize the receivers based on their critical time to avoid collision. This paper presents a more efficient multicast routing scheme that can reduce unnecessary transmissions and also use adaptive transmission range. The multicast scheme involves methods to identify an abnormal vehicle, the vehicles that may be endangered by the abnormal vehicle, and the latest time for each endangered vehicle to receive the warning message in order to avoid the danger. We transform this multicast routing problem into a delay-constrained minimum Steiner tree problem. Therefore, we can use existing algorithms to solve the problem. The advantages of our multicast routing scheme are mainly its potential to support various road traffic scenarios, to optimize the wireless channel utilization, and to prioritize the receivers.

Community engagement for sustainable urban futures : editorial preface

This special issue of Futures is concerned with community engagement strategies that help to inform medium and long-term futures studies in order to foster sustainable urban environments. Recent special issues of Futures, such as Human Extinction (41:10) and Utopian Thought (41:4), reflect the increasing significance of sustainability issues, which is why we present another crucial component of sustainability, community engagement. Responding to futurists’ long term concerns about climate change outlined in Futures 41(9) [1], Stevenson concluded that we can no longer support infinite growth, and that our goal should be to reshape the economy to let us live within our means. In the face of the continued and accelerated crisis in environmental, economic and social sustainability, a number of trends informed our call for papers on the possible role of community engagement in contributing to enhanced urban sustainability: • Changes in the public sphere in terms of participation, online deliberation systems, polity of urban futures; • The possible use of user-generated content for urban planning (paralleling the rise of user generated content elsewhere); • The related role of social networking, collective and civic intelligence, and crowd- sourcing in urban futures; • The rise of technologies such as wireless Internet and mobile applications, and the impact of neogeography, simulations and 3D virtual environments that reproduce and analyse complex social phenomena and city systems in urban futures, design and planning.

PIPP #1 - Pedestrian Interaction Patch Project

The Pedestrian Interaction Patch Project (PIPP) seeks to exert influence over and encourage abnormal pedestrian behavior. By placing an unadvertised (and non recording) interactive video manipulation system and projection source in a high traffic public area, the PIPP allows pedestrians to privately (and publically) re-engage with a previously inactive physical environment, like a commonly used walkway or corridor. This system, the results of which are projected in real time on the architectural surface, inadvertently provides pedestrians with questions around preconceived notions of self and space. In an attempt to re-activate our relationship with the physical surrounds we occupy each day the PIPP creates a new set of memories to be recalled as we re-enter known environments once PIPP has moved on and as such re-enlivens our relationship with the everyday architecture we stroll past everyday. The PIPP environment is controlled using the software program Isadora, devised by Mark Coniglio at Troika Ranch, and contains a series of video manipulation patches that are designed to not only grab the pedestrians attention but to also encourage a sense of play and interaction between the architecture, the digital environment, the initially unsuspecting participant(s) and the pedestrian audience. The PIPP was included as part of the planned walking tour for the “Playing in Urban Spaces” seminar day, and was an installation that ran for the length of the symposium in a reclaimed pedestrian space that was encountered by both the participants and general public during the course of the day long event. Ideally once discovered PIPP encouraged pedestrians to return through the course of the seminar day to see if the environmental patches had changed or altered, and changed their standard route to include the PIPP installation or to avoid it, either way, encouraging an active response to the pathways normally traveled or newly discovered each day.

Disturbed appetite and nutrient intake in peritoneal dialysis patients

OBJECTIVE Malnutrition is common among peritoneal dialysis (PD) patients. Reduced nutrient intake contributes to this. It has long been assumed that this reflects disturbed appetite. We set out to define the appetite profiles of a group of PD patients using a novel technique. DESIGN Prospective, cross-sectional comparison of PD patients versus controls. SETTING Teaching hospital dialysis unit. PATIENTS 39 PD patients and 42 healthy controls. INTERVENTION Visual analog ratings were recorded at hourly intervals to generate daily profiles for hunger and fullness. Summary statistics were generated to compare the groups. Food intake was measured using 3-day dietary records. MAIN OUTCOME MEASURES Hunger and fullness profiles. Derived hunger and fullness scores. RESULTS Controls demonstrated peaks of hunger before mealtimes, with fullness scores peaking after meals. The PD profiles had much reduced premeal hunger peaks. A postmeal reduction in hunger was evident, but the rest of the trace was flat. The PD fullness profile was also flatter than in the controls. Mean scores were similar despite the marked discrepancy in the profiles. The PD group had lower peak hunger and less diurnal variability in their hunger scores. They also demonstrated much less change in fullness rating around mealtimes, while the mean and peak fullness scores were little different. The reported nutrient intake was significantly lower for PD. CONCLUSION The data suggest that PD patients normalize their mean appetite perception at a lower level of nutrient intake than controls, suggesting that patient-reported appetite may be misleading in clinical practice. There is a loss of the usual daily variation for the PD group, which may contribute to their reduced food intake. The technique described here could be used to assess the impact of interventions upon the abnormal PD appetite profile.

Disability, deinstitutionalisation and discourse : an analysis of institutional reform policies in Queensland, 1994-1996

The closure of large institutions for people with intellectual disability and the subsequent shift to community living has been a feature of social policies in most western democracies for more than two decades. While the move from congregated settings to homes in the community has been heralded as a positive and desirable strategy, deinstitutionalisation has continued to be a controversial policy and practice. This research critically analyses the implementation of a deinstitutionalisation policy called Institutional Reform in the state of Queensland from May 1994 until it was dismantled under a new government in the middle of 1996. A trajectory study of the policy from early conceptualisation through its development, implementation and final extinction was undertaken. Several methods were utilised in the research including the textual analyis of policy documents, discussion papers and newspaper articles, interviews with stakeholders and participant observation. The research draws on theories of discourse and focuses on how discourses of disability shape policy and practice. The thesis outlines a number of implications for policy implementation more generally as well as for disability services. In particular, the theoretical framework builds on Fulcher's (1989) disabling discourses - medical, charity, lay and rights - and identifies two additional discourses of economics and inclusion. The thesis argues that competing disability discourses operated in powerful ways to shape the implementation of the policy and illustrates how older discourses based on fear and prejudice were promoted to positions of dominance and power.

Swept frequency biompedance analysis for the determination of body water compartments

Bioelectrical impedance analysis, (BIA), is a method of body composition analysis first investigated in 1962 which has recently received much attention by a number of research groups. The reasons for this recent interest are its advantages, (viz: inexpensive, non-invasive and portable) and also the increasing interest in the diagnostic value of body composition analysis. The concept utilised by BIA to predict body water volumes is the proportional relationship for a simple cylindrical conductor, (volume oc length2/resistance), which allows the volume to be predicted from the measured resistance and length. Most of the research to date has measured the body's resistance to the passage of a 50· kHz AC current to predict total body water, (TBW). Several research groups have investigated the application of AC currents at lower frequencies, (eg 5 kHz), to predict extracellular water, (ECW). However all research to date using BIA to predict body water volumes has used the impedance measured at a discrete frequency or frequencies. This thesis investigates the variation of impedance and phase of biological systems over a range of frequencies and describes the development of a swept frequency bioimpedance meter which measures impedance and phase at 496 frequencies ranging from 4 kHz to 1 MHz. The impedance of any biological system varies with the frequency of the applied current. The graph of reactance vs resistance yields a circular arc with the resistance decreasing with increasing frequency and reactance increasing from zero to a maximum then decreasing to zero. Computer programs were written to analyse the measured impedance spectrum and determine the impedance, Zc, at the characteristic frequency, (the frequency at which the reactance is a maximum). The fitted locus of the measured data was extrapolated to determine the resistance, Ro, at zero frequency; a value that cannot be measured directly using surface electrodes. The explanation of the theoretical basis for selecting these impedance values (Zc and Ro), to predict TBW and ECW is presented. Studies were conducted on a group of normal healthy animals, (n=42), in which TBW and ECW were determined by the gold standard of isotope dilution. The prediction quotients L2/Zc and L2/Ro, (L=length), yielded standard errors of 4.2% and 3.2% respectively, and were found to be significantly better than previously reported, empirically determined prediction quotients derived from measurements at a single frequency. The prediction equations established in this group of normal healthy animals were applied to a group of animals with abnormally low fluid levels, (n=20), and also to a group with an abnormal balance of extra-cellular to intracellular fluids, (n=20). In both cases the equations using L2/Zc and L2/Ro accurately and precisely predicted TBW and ECW. This demonstrated that the technique developed using multiple frequency bioelectrical impedance analysis, (MFBIA), can accurately predict both TBW and ECW in both normal and abnormal animals, (with standard errors of the estimate of 6% and 3% for TBW and ECW respectively). Isotope dilution techniques were used to determine TBW and ECW in a group of 60 healthy human subjects, (male. and female, aged between 18 and 45). Whole body impedance measurements were recorded on each subject using the MFBIA technique and the correlations between body water volumes, (TBW and ECW), and heighe/impedance, (for all measured frequencies), were compared. The prediction quotients H2/Zc and H2/Ro, (H=height), again yielded the highest correlation with TBW and ECW respectively with corresponding standard errors of 5.2% and 10%. The values of the correlation coefficients obtained in this study were very similar to those recently reported by others. It was also observed that in healthy human subjects the impedance measured at virtually any frequency yielded correlations not significantly different from those obtained from the MFBIA quotients. This phenomenon has been reported by other research groups and emphasises the need to validate the technique by investigating its application in one or more groups with abnormalities in fluid levels. The clinical application of MFBIA was trialled and its capability of detecting lymphoedema, (an excess of extracellular fluid), was investigated. The MFBIA technique was demonstrated to be significantly more sensitive, (P<.05), in detecting lymphoedema than the current technique of circumferential measurements. MFBIA was also shown to provide valuable information describing the changes in the quantity of muscle mass of the patient during the course of the treatment. The determination of body composition, (viz TBW and ECW), by MFBIA has been shown to be a significant improvement on previous bioelectrical impedance techniques. The merit of the MFBIA technique is evidenced in its accurate, precise and valid application in animal groups with a wide variation in body fluid volumes and balances. The multiple frequency bioelectrical impedance analysis technique developed in this study provides accurate and precise estimates of body composition, (viz TBW and ECW), regardless of the individual's state of health.

Development and synthesis of innovative approaches to the surgical assessment of articular cartilage degeneration

This research has established, through ultrasound, near infrared spectroscopy and biomechanics experiments, parameters and parametric relationships that can form the framework for quantifying the integrity of the articular cartilage-on-bone laminate, and objectively distinguish between normal/healthy and abnormal/degenerated joint tissue, with a focus on articular cartilage. This has been achieved by: 1. using traditional experimental methods to produce new parameters for cartilage assessment; 2. using novel methodologies to develop new parameters; and 3. investigating the interrelationships between mechanical, structural and molec- ular properties to identify and select those parameters and methodologies that can be used in a future arthroscopic probe based on points 1 and 2. By combining the molecular, micro- and macro-structural characteristics of the tissue with its mechanical properties, we arrive at a set of critical benchmarking parameters for viable and early-stage non-viable cartilage. The interrelationships between these characteristics, examined using a multivariate analysis based on principal components analysis, multiple linear regression and general linear modeling, could then to deter- mine those parameters and relationships which have the potential to be developed into a future clinical device. Specifically, this research has found that the ultrasound and near infrared techniques can subsume the mechanical parameters and combine to characterise the tissue at the molecular, structural and mechanical levels over the full depth of the cartilage matrix. It is the opinion in this thesis that by enabling the determination of the precise area of in uence of a focal defect or disease in the joint, demarcating the boundaries of articular cartilage with dierent levels of degeneration around a focal defect, better surgical decisions that will advance the processes of joint management and treatment will be achieved. Providing the basis for a surgical tool, this research will contribute to the enhancement and quanti�cation of arthroscopic procedures, extending to post- treatment monitoring and as a research tool, will enable a robust method for evaluating developing (particularly focalised) treatments.

The role of the audit committee and institutional investors in constraining earnings management : evidence from Chinese firms listed in Hong Kong

Using data from 2004 to 2008, we find that an audit committee is an important monitoring mechanism as audit committee independence, expertise and size are associated with reduced levels of abnormal accruals, our measure of earnings management. This study also attempts to discern when the monitoring role of the audit committee is more salient for the firm. We find that ownership concentration and the presence of government officials on the audit committee are important determinants of the negative association between audit committee characteristics and earnings management. In contrast, we find no significant associations between the audit committee and abnormal accruals for Chinese firms listed only on the Chinese domestic Stock Exchanges. The paper contributes to the corporate governance literature in a transitional economy. Identifying the role of audit committees of firms listed on markets other than the domicile market demonstrates the importance of considering the institutional setting in governance research.

Can an effective audit committee help to mitigate earnings management in Chinese firms listed in Hong Kong?

This paper attempts to determine whether the adoption of recommended corporate governance practices by Chinese firms is associated with less earnings management proxied by abnormal accruals. We examine the role of the audit committee and ownership concentration in preventing earnings management using Chinese firms listed in Hong Kong. The results of this preliminary analysis show that the frequency of audit committee meetings is associated with reduced levels of abnormal accruals, our measure of earnings management. We conclude that audit committee activity is an important factor in constraining the propensity of managers to engage in earnings management. In contrast, we find that the size of the audit committee is associated with increased levels of abnormal accruals and suggest that increasing the size of the audit committee creates information asymmetry between the audit committee and management that reduces the monitoring capacity of the audit committee. We do not find any association between audit committee independence, financial and industry experience, or ownership concentration and abnormal accruals.

Cross-talk of subchondral bone osteoblasts and articular cartilage chondrocytes : a new insight in understanding osteoarthritis pathogenesis

Osteoarthritis (OA) is the most common musculoskeletal disorder and represents a major health burden to society. In the course of the pathological development of OA, articular cartilage chondrocytes (ACCs) undergo atypical phenotype changes characterized by the expression of hypertrophic differentiation markers. Also, the adjacent subchondral bone shows signs of abnormal mineral density and enhanced production of bone turnover markers, indicative of osteoblast dysfunction. Collectively these findings indicate that the pathological changes typical of OA, involve alterations of the phenotypic properties of cells in both the subchondral bone and articular cartilage. However, the mechanism(s) by which these changes occur during OA development are not completely understood. The purpose of this project was to address the question of how subchondral bone osteoblasts (SBOs) and ACCs interact with each other with respect to regulation of respective cells’ phenotypic properties and in particular the involvement of mitogen activated protein kinase (MAPK) signalling pathways under normal and OA joint condition. We also endeavoured to test the influence of cross-talk between SBOs and ACCs isolated from normal and OA joint on matrix metalloproteinase (MMP) expression. For this purpose tissues from the knees of OA patients and normal controls were collected to isolate SBOs and ACCs. The cellular cross-talk of SBOs and ACCs were studied by means of both direct and indirect co-culture systems, which made it possible to identify the role of both membrane bound and soluble factors. Histology, immunohistochemistry, qRT-PCR, zymography, ELISA and western blotting were some of the techniques applied to distinguish the changes in the co-cultured vs. non co-cultured cells. The MAPK signalling pathways were probed by using targeted MAPK inhibitors, and their activity monitored by western blot analysis using phospho MAPK specific antibodies. Our co-culture studies demonstrated that OA ACCs enhanced the SBOs differentiation compared to normal ACCs. We demonstrated that OA ACCs induced these phenotypic changes in the SBOs via activating an ERK1/2 signalling pathway. The findings from this study thus provided clear evidence that OA ACCs play an integral role in altering the SBO phenotype. In the second study, we tested the influence of normal SBOs and OA SBOs on ACCs phenotype changes. The results showed that OA SBOs increased the hypertrophic gene expression in co-cultured ACCs compared to normal SBOs, a phenotype which is considered as pathological to the health and integrity of articular cartilage. It was demonstrated that these phenotype changes occurred via de-activation of p38 and activation of ERK1/2 signaling pathways. These findings suggest that the pathological interaction of OA SBOs with ACCs is mediated by cross-talking between ERK1/2 and p38 pathways, resulting in ACCs undergoing hypertrophic differentiation. Subsequent experiments to determine the effect on MMP regulation, of SBOs and ACCs cross-talk, revealed that co-culturing OA SBOs with ACCs significantly enhanced the proteolytic activity and expression of MMP-2 and MMP-9. In turn, co-culture of OA ACCs with SBOs led to abundant MMP-2 expression in SBOs. Furthermore, we showed that the addition of ERK1/2 and JNK inhibitors reversed the elevated MMP-2 and MMP-9 production which otherwise resulted from the interactions of OA SBOs-ACCs. Thus, this study has demonstrated that the altered interactions between OA SBOs-ACCs are capable of triggering the pathological pathways leading to degenerative changes seen in the osteoarthritic joint. In conclusion, the body of work presented in this dissertation has given clear in vitro evidence that the altered bi-directional communication of SBOs and ACCs may play a role in OA development and that this process was mediated by MAPK signalling pathways. Targeting these altered interactions by the use of MAPK inhibitors may provide the scientific rationale for the development of novel therapeutic strategies in the treatment and management of OA.

Contracting bubbles in Hele-Shaw cells with a power-law fluid

The problem of bubble contraction in a Hele-Shaw cell is studied for the case in which the surrounding fluid is of power-law type. A small perturbation of the radially symmetric problem is first considered, focussing on the behaviour just before the bubble vanishes, it being found that for shear-thinning fluids the radially symmetric solution is stable, while for shear-thickening fluids the aspect ratio of the bubble boundary increases. The borderline (Newtonian) case considered previously is neutrally stable, the bubble boundary becoming elliptic in shape with the eccentricity of the ellipse depending on the initial data. Further light is shed on the bubble contraction problem by considering a long thin Hele-Shaw cell: for early times the leading-order behaviour is one-dimensional in this limit; however, as the bubble contracts its evolution is ultimately determined by the solution of a Wiener-Hopf problem, the transition between the long-thin limit and the extinction limit in which the bubble vanishes being described by what is in effect a similarity solution of the second kind. This same solution describes the generic (slit-like) extinction behaviour for shear-thickening fluids, the interface profiles that generalise the ellipses that characterise the Newtonian case being constructed by the Wiener-Hopf calculation.

Sustainability : driver for decision making in infrastructure

With the growing importance of sustainability assessment in the construction industry, many green building rating schemes have been adopted in the building sector of Australia. However, there is an abnormal delay in the similar adoption in the infrastructure sector. This prolonged delay in practice poses a challenge in mapping the project objectives with sustainability outcomes. Responding to the challenge of sustainable development in infrastructure, it is critical to create a set of decision indicators for sustainability in infrastructure, which to be used in conjunction with the emerging infrastructure sustainability assessment framework of the Australian Green Infrastructure Council. The various literature sources confirm the lack of correlation between sustainability and infrastructure. This theoretical missing link signifies the crucial validation of the interrelationship and interdependency in sustainability, decision making and infrastructure. This validation is vital for the development of decision indicators for sustainability in infrastructure. Admittedly, underpinned by the serious socio-environmental vulnerability, the traditional focus on economic emphasis in infrastructure development needs to be drifted towards the appropriate decisions for sustainability enhancing the positive social and environmental outcomes. Moreover, the research findings suggest sustainability being observed as powerful socio-political and influential socio-environmental driver in deciding the infrastructure needs and its development. These newly developed sustainability decision indicators create the impetus for change leading to sustainability in infrastructure by integrating the societal cares, environmental concerns into the holistic financial consideration. Radically, this development seeks to transform principles into actions for infrastructure sustainability. Lastly, the thesis concludes with knowledge contribution in five significant areas and future research opportunities. The consolidated research outcomes suggest that the development of decision indicators has demonstrated sustainability as a pivotal driver for decision making in infrastructure.

Subchondral bone osteoblasts can induce chondrocyte mineralization during osteoarthritis and this process is relevant to cartilage degradation

Pathological mineralization of articular cartilage is a characteristic feature of osteoarthritis (OA); however, the underlying mechanisms, and their relevance to cartilage degeneration, are not clear. The involvement of subchondral bone changes in OA have been reported previously with the characterization of abnormal subchondral bone mineral density (BMD), osteiod volume, altered bone mechanical parameters and an increase in bone turnover markers. A number of osteoarthritic animal models have demonstrated that subchondral bone changes often precede cartilage degeneration. In this study site specific localization of mineralization markers were detected in the OA cartilage. Chondrocytes and osteoblasts derived from OA cartilage and subchondral bone showed a significant increase in the mRNA expressions of mineralization markers. Interestingly, osteoblasts from OA subchondral bone could significantly decrease cartilage matrix expression; whereas, increase mineralization of chondrocytes (Figure 1). Osteogenic factors, such as CBFA1, ALP, and type X collagen (Col-X), were detected in chondrocytes under mineralization conditions (Figure 2). Furthermore, chondrocyte mineralization was followed by increased mRNA and protein levels of MMP-2, MMP-9 and MMP-13, all of which are detrimental to cartilage integrity in vivo. The data reported here suggests that the upregulation of subchondral bone-mineralization, typical of OA progression, causes cartilage mineralization, and that the mineralization of chondrocytes induce increased MMP levels with a subsequent degradation of the articular cartilage.

Altered cell interactions of subchondral bone osteoblasts and articular chondrocytes in osteoarthritis is through the mediation of ERK1/2 phosphorylation

Introduction: Osteoarthritis (OA) is the most common musculoskeletal disorder and represents a major health burden to society. In the course of the pathological development of OA, articular cartilage chondrocytes (ACCs) undergo a typical phenotype changes characterized by the expression of hypertrophic differentiation markers. Also, the adjacent subchondral bone shows signs of abnormal mineral density and enhanced production of bone turnover markers, indicative of osteoblast dysfunction. However, the mechanism(s) by which these changes occur during the OA development are not completely understood. Materials and Methods: ACCs and subchondral bone osteoblasts (SBOs) were harvested from OA and healthy patients for the cross-talk studies between normal and OA ACCs and SBOs. The involvement of mitogen activated protein kinase (MAPK) signalling pathway during the cell-cell interactions was analysed by zymography, ELISA and western blotting methods. Results: The direct and in-direct co-culture studies showed that OA (ACCs and SBOs) cells induced osteoarthritic changes of normal (ACC and SBOs) cells. This altered cell interaction induced by OA cells significantly aggravated the proteolytic activity, which resulted cartilage degeneration. The altered cell interaction appeared to significantly activate ERK 1/2 phosphorylation and inhibition of MAPK-ERK 1/2 pathway reversed the osteoarthrtitic phenotypic changes. Discussion and Conclusion: Our study has demonstrated that the altered bi-directional communication of SBOs and ACCs are critical for initiation and progression of OA related changes and that this process is mediated by MAPK signalling pathways. Targeting these altered interactions by the use of MAPK inhibitors may provide the scientific rationale for the development of novel therapeutic strategies in the treatment and management of OA related disorders.

Immunohistochemical analysis of structural changes in collagen for the assessment of osteoarthritis

Collagen fibrillation within articular cartilage (AC) plays a key role in joint osteoarthritis (OA) progression and, therefore, studying collagen synthesis changes could be an indicator for use in the assessment of OA. Various staining techniques have been developed and used to determine the collagen network transformation under microscopy. However, because collagen and proteoglycan coexist and have the same index of refraction, conventional methods for specific visualization of collagen tissue is difficult. This study aimed to develop an advanced staining technique to distinguish collagen from proteoglycan and to determine its evolution in relation to OA progression using optical and laser scanning confocal microscopy (LSCM). A number of AC samples were obtained from sheep joints, including both healthy and abnormal joints with OA grades 1 to 3. The samples were stained using two different trichrome methods and immunohistochemistry (IHC) to stain both colourimetrically and with fluorescence. Using optical microscopy and LSCM, the present authors demonstrated that the IHC technique stains collagens only, allowing the collagen network to be separated and directly investigated. Fluorescently-stained IHC samples were also subjected to LSCM to obtain three-dimensional images of the collagen fibres. Changes in the collagen fibres were then correlated with the grade of OA in tissue. This study is the first to successfully utilize the IHC staining technique in conjunction with laser scanning confocal microscopy. This is a valuable tool for assessing changes to articular cartilage in OA.