Health monitoring of short-and medium-spen bridges using an improved modal strain energy method

Increasing the importance and use of infrastructures such as bridges, demands more effective structural health monitoring (SHM) systems. SHM has well addressed the damage detection issues through several methods such as modal strain energy (MSE). Many of the available MSE methods either have been validated for limited type of structures such as beams or their performance is not satisfactory. Therefore, it requires a further improvement and validation of them for different types of structures. In this study, an MSE method was mathematically improved to precisely quantify the structural damage at an early stage of formation. Initially, the MSE equation was accurately formulated considering the damaged stiffness and then it was used for derivation of a more accurate sensitivity matrix. Verification of the improved method was done through two plane structures: a steel truss bridge and a concrete frame bridge models that demonstrate the framework of a short- and medium-span of bridge samples. Two damage scenarios including single- and multiple-damage were considered to occur in each structure. Then, for each structure, both intact and damaged, modal analysis was performed using STRAND7. Effects of up to 5 per cent noise were also comprised. The simulated mode shapes and natural frequencies derived were then imported to a MATLAB code. The results indicate that the improved method converges fast and performs well in agreement with numerical assumptions with few computational cycles. In presence of some noise level, it performs quite well too. The findings of this study can be numerically extended to 2D infrastructures particularly short- and medium-span bridges to detect the damage and quantify it more accurately. The method is capable of providing a proper SHM that facilitates timely maintenance of bridges to minimise the possible loss of lives and properties.

Biophilic urbanism : harnessing natural elements to enhance the performance of constructed assets

Creating climate resilient, low-carbon urban environments and assets is a policy goal of many governments and city planners today, and an important issue for constructed asset owners. Stakeholders and decision makers in urban environments are also responding to growing evidence that cities need to increase their densities to reduce their footprint in the face of growing urban populations. Meanwhile, research is highlighting the importance of balancing such density with urban nature, to provide a range of health and wellbeing benefits to residents as well as to mitigate the environmental and economic impacts of heavily built up, impervious urban areas. Concurrently achieving this suite of objectives requires the coordination and cooperation of multiple stakeholder groups, with urban development and investment increasingly involving many private and public actors. Strategies are needed that can provide ‘win-win’ outcomes to benefit these multiple stakeholders, and provide immediate benefits while also addressing the emerging challenges of climate change, resource shortages and urban population growth. Within this context, ‘biophilic urbanism’ is emerging as an important design principle for buildings and urban areas. Through the use of a suite of natural design elements, biophilic urbanism has the potential to address multiple pressures related to climate change, increasing urban populations, finite resources and human’s inherent need for contact with nature. The principle directs the creation of urban environments that are conducive to life, delivering a range of benefits to stakeholders including building owners, occupiers and the surrounding community. This paper introduces the principle of biophilic urbanism and discusses opportunities for improved building occupant experience and performance of constructed assets, as well as addressing other sustainability objectives including climate change mitigation and adaptation. The paper presents an emerging process for considering biophilic design opportunities at different scales and highlights implications for the built environment industry. This process draws on findings of a study of leading cities internationally and learnings related to economic and policy considerations. This included literature review, two stakeholder workshops, and extensive industry consultation, funded by the Sustainable Built Environment National Research Centre through core project partners Western Australian Department of Finance, Parsons Brinckerhoff, Townsville City Council CitySolar Program, Green Roofs Australasia, and PlantUp.

Considering a whole-of-community approach to integrating nature in cities, an international case study of Vauban, Germany

Globally, cities face a convergence of complex and rapidly evolving challenges, including climate change, resource shortages, population growth and urbanization, and financial pressures. Biophilic urbanism is an emerging design principle capable of considering the multidimensional and interdependent complexities of urban systems and infrastructure, which through the use of natural design features, can meet society’s inherent need for contact with nature, and assist efforts to respond to these growing challenges. Considering the imperative for addressing these challenges, this paper proposes that significant lessons can be learned from existing examples of biophilic urbanism, avoiding ‘re-invention of the wheel’ and facilitating accelerated innovation in other areas. Vauban is a 38-hectare brownfield development located 3 kilometers from the centre of Germany’s ‘ecological capital’ of Freiburg city. It was developed using an innovative process with strong community participation and reinterpreted developer roles to produce an example of integrated sustainability. Innovation in transport, energy, housing, development and water treatment has enabled a relatively high-density, mixed-use development that integrates a considerable amount of nature. This paper discusses Vauban in light of research undertaken over the last two years through the Sustainable Built Environment National Research Centre in Australia, to investigate emerging elements of ‘biophilic urbanism’ (nature-loving cities), and their potential to be mainstreamed within urban environments. The paper considers the interplay between the policies, community dynamics and innovations in Vauban, within the context of the culture, history and practice of sustainability in Germany, and how these have enabled nature to be integrated into the urban environment of Vauban while achieving other desirable goals for urban areas. It highlights potential applications from Vauban for Australian cities.

Output feedback optimal control with contraints

In Chapters 1 through 9 of the book (with the exception of a brief discussion on observers and integral action in Section 5.5 of Chapter 5) we considered constrained optimal control problems for systems without uncertainty, that is, with no unmodelled dynamics or disturbances, and where the full state was available for measurement. More realistically, however, it is necessary to consider control problems for systems with uncertainty. This chapter addresses some of the issues that arise in this situation. As in Chapter 9, we adopt a stochastic description of uncertainty, which associates probability distributions to the uncertain elements, that is, disturbances and initial conditions. (See Section 12.6 for references to alternative approaches to model uncertainty.) When incomplete state information exists, a popular observer-based control strategy in the presence of stochastic disturbances is to use the certainty equivalence [CE] principle, introduced in Section 5.5 of Chapter 5 for deterministic systems. In the stochastic framework, CE consists of estimating the state and then using these estimates as if they were the true state in the control law that results if the problem were formulated as a deterministic problem (that is, without uncertainty). This strategy is motivated by the unconstrained problem with a quadratic objective function, for which CE is indeed the optimal solution (˚Astr¨om 1970, Bertsekas 1976). One of the aims of this chapter is to explore the issues that arise from the use of CE in RHC in the presence of constraints. We then turn to the obvious question about the optimality of the CE principle. We show that CE is, indeed, not optimal in general. We also analyse the possibility of obtaining truly optimal solutions for single input linear systems with input constraints and uncertainty related to output feedback and stochastic disturbances.We first find the optimal solution for the case of horizon N = 1, and then we indicate the complications that arise in the case of horizon N = 2. Our conclusion is that, for the case of linear constrained systems, the extra effort involved in the optimal feedback policy is probably not justified in practice. Indeed, we show by example that CE can give near optimal performance. We thus advocate this approach in real applications.

Validation tool for traction force microscopy

Traction force microscopy (TFM) is commonly used to estimate cells’ traction forces from the deformation that they cause on their substrate. The accuracy of TFM highly depends on the computational methods used to measure the deformation of the substrate and estimate the forces, and also on the specifics of the experimental set-up. Computer simulations can be used to evaluate the effect of both the computational methods and the experimental set-up without the need to perform numerous experiments. Here, we present one such TFM simulator that addresses several limitations of the existing ones. As a proof of principle, we recreate a TFM experimental set-up, and apply a classic 2D TFM algorithm to recover the forces. In summary, our simulator provides a valuable tool to study the performance, refine experimentally, and guide the extraction of biological conclusions from TFM experiments.

Pandemic planning as risk management : how fared the Australian Federation?

The role of law in managing public health challenges such as influenza pandemics poses special challenges. This article reviews Australian plans in the context of the H1N1 09 experience to assess whether risk management was facilitated or inhibited by the "number" of levels or phases of management, the degree of prescriptive detail for particular phases, the number of plans, the clarity of the relationship between them, and the role of the media. Despite differences in the content and form of the plans at the time of the H1N1 09 emerging pandemic, the article argues that in practice, the plans proved to be responsive and robust bases for managing pandemic risks. It is suggested that this was because the plans proved to be frameworks for coordination rather than prescriptive straitjackets, to be only one component of the regulatory response, and to offer the varied tool box of possible responses, as called for by the theory of responsive regulation. Consistent with the principle of subsidiarity, it is argued that the plans did not inhibit localised responses such as selective school closures or rapid responses to selected populations such as cruise ship passengers.

Non-linear refined finite element elastic analysis of steel frames with generalized transverse member loads

In the finite element modelling of steel frames, external loads usually act along the members rather than at the nodes only. Conventionally, when a member is subjected to these transverse loads, they are converted to nodal forces which act at the ends of the elements into which the member is discretised by either lumping or consistent nodal load approaches. For a contemporary geometrically non-linear analysis in which the axial force in the member is large, accurate solutions are achieved by discretising the member into many elements, which can produce unfavourable consequences on the efficacy of the method for analysing large steel frames. Herein, a numerical technique to include the transverse loading in the non-linear stiffness formulation for a single element is proposed, and which is able to predict the structural responses of steel frames involving the effects of first-order member loads as well as the second-order coupling effect between the transverse load and the axial force in the member. This allows for a minimal discretisation of a frame for second-order analysis. For those conventional analyses which do include transverse member loading, prescribed stiffness matrices must be used for the plethora of specific loading patterns encountered. This paper shows, however, that the principle of superposition can be applied to the equilibrium condition, so that the form of the stiffness matrix remains unchanged with only the magnitude of the loading being needed to be changed in the stiffness formulation. This novelty allows for a very useful generalised stiffness formulation for a single higher-order element with arbitrary transverse loading patterns to be formulated. The results are verified using analytical stability function studies, as well as with numerical results reported by independent researchers on several simple structural frames.

Lumbar epidural steroids are not cost effective in sciatica

Background Lumbar Epidural Steroids Injections (ESI’s) have previously been shown to provide some degree of pain relief in sciatica. Number Needed To Treat (NNT) to achieve 50% pain relief has been estimated at 7 from the results of randomised controlled trials. Pain relief is temporary. They remain one of the most commonly provided procedures in the UK. It is unknown whether this pain relief represents good value for money. Methods 228 patients were randomised into a multi-centre Double Blind Randomised Controlled Trial. Subjects received up to 3 ESI’s or intra-spinous saline depending on response and fall off with the first injection. All other treatments were permitted. All received a review of analgesia, education and physical therapy. Quality of life was assessed using the SF36 at 6 points and compared using independent sample t-tests. Follow up was up to 1 yr. Missing data was imputed using last observation carried forward (LOCF). QALY’s (Quality of Life Years) were derived from preference based heath values (summary health utility score). SF-6D health state classification was derived from SF-36 raw score data. Standard gambles (SG) were calculated using Model 10. SG scores were calculated on trial results. LOCF was not used for this. Instead average SG were derived for a subset of patients with observations for all visits up to week 12. Incremental QALY’s were derived as the difference in the area between the SG curve for the active group and placebo group. Results SF36 domains showed a significant improvement in pain at week 3 but this was not sustained (mean 54 Active vs 61 Placebo P<0.05). Other domains did not show any significant gains compared with placebo. For derivation of SG the number in the sample in each period differed. In week 12, average SG scores for active and placebo converged. In other words, the health gain for the active group as measured by SG was achieved by the placebo group by week 12. The incremental QALY gained for a patient under the trial protocol compared with the standard care package was 0.0059350. This is equivalent to an additional 2.2 days of full health. The cost per QALY gained to the provider from a patient management strategy administering one epidural as suggested by results was £25 745.68. This result was derived assuming that the gain in QALY data calculated for patients under the trial protocol would approximate that under a patient management strategy based on the trial results (one ESI). This is above the threshold suggested by some as a cost effective treatment. Conclusions The transient benefit in pain relief afforded by ESI’s does not appear to be cost-effective. Further work is needed to develop more cost-effective conservative treatments for sciatica.

Neutral and charged boron-doped fullerenes for CO2 adsorption

Recently, the capture and storage of CO2 have attracted research interest as a strategy to reduce the global emissions of greenhouse gases. It is crucial to find suitable materials to achieve an efficient CO2 capture. Here we report our study of CO2 adsorption on boron-doped C60 fullerene in the neutral state and in the 1e−-charged state. We use first principle density functional calculations to simulate the CO2 adsorption. The results show that CO2 can form weak interactions with the BC59 cage in its neutral state and the interactions can be enhanced significantly by introducing an extra electron to the system.

Community media production : access, institutions, and ethics

In policy terms, community media are known as the “third sector” of the media. The description reflects the historical expectation that community media can fulfill a need not met by the commercial and public service broadcasters. A defining element of this “need” has been the means to production for nonprofessionals, particularly groups not represented in the mainstream media. The historical construction of community media reveals production to be a guiding principle; both a means and an end in itself. This chapter examines the various rationales underpinning community media production, including empowerment, media diversity, and the independent producer movement. Using case studies from youth media, the chapter critiques producer-centric models of community media. In the contemporary media environment, production alone cannot meet the social needs that community media were established to address. Instead, I propose a rationale that combines both production and consumption ethics.

The LCC15-MB human breast cancer cell line expresses osteopontin and exhibits an invasive and metastatic phenotype

We have characterized the LCC15-MB cell line which was recently derived from a breast carcinoma metastasis resected from the femur of a 29-year-old woman. LCC15-MB cells are vimentin (VIM) positive, exhibit a stellate morphology in routine cell culture, and form penetrating colonies when embedded in three-dimensional gels of Matrigel or fibrillar collagen. They show high levels of activity in the Boyden chamber chemomigration and chemoinvasion assays, and like other invasive human breast cancer (HBC) cell lines, LCC15-MB cells activate matrix-metalloproteinase-2 in response to treatment with concanavalin A. In addition, these cells are tumorigenic when implanted subcutaneously in nude mice and recolonize bone after arterial injection. Interestingly, both the primary lesion and the bone metastasis from which LCC15-MB were derived, as well as the resultant cell line, abundantly express the bone matrix protein osteopontin (OPN). OPN is also expressed by the highly metastatic MDA-MB-435 cells, but not other invasive or noninvasive HBC cell lines. Expression of OPN is retained in the subcutaneous xenograft and intraosseous metastases of LCC15-MB as detected by immunohistochemistry. Both VIM and OPN expression have been associated with breast cancer invasion and metastasis, and their expression by the LCC15-MB cell line is consistent with its derivation from a highly aggressive breast cancer. These cells provide a useful model for studying molecular mechanisms important for breast cancer metastasis to bone and, in particular, the implication(s) of OPN and VIM expression in this process.

An analysis of ranking principles and retrieval strategies

The assumptions underlying the Probability Ranking Principle (PRP) have led to a number of alternative approaches that cater or compensate for the PRP’s limitations. All alternatives deviate from the PRP by incorporating dependencies. This results in a re-ranking that promotes or demotes documents depending upon their relationship with the documents that have been already ranked. In this paper, we compare and contrast the behaviour of state-of-the-art ranking strategies and principles. To do so, we tease out analytical relationships between the ranking approaches and we investigate the document kinematics to visualise the effects of the different approaches on document ranking.

Acquisition of estrogen independence and antiestrogen resistance in breast cancer : association with the invasive and metastatic phenotype

A significant percentage of human breast cancer (HBC) is dependent upon the ovarian hormone estrogen for its onset and progression. The presence or lack of estrogen receptors (ERs) in human breast cancer is an important determinant both of prognosis and of choice of treatment - a poorer prognosis being associated with ER–ve disease. Cell lines established from human breast cancer provide models for breast cancer in various stages of progression (Engel & Young 1978). When grown as tumors in athymic nude mice, these lines represent the major in vivo experimental model for HBC studies (Brünner et al 1987). The ease of both in vitro and in vivo maintenance, the human derivation of the tissue, and the similarities in plasma estrogen levels between ovariectomized nude mice and postmenopausal women (Seibert et al. 1983, Brünner et al. 1986), make the growth of human breast cancer cell lines in nude mice an attractive...

University of Glasgow at ImageCLEFPhoto 2009 : optimising similarity and diversity in image retrieval

In this paper we describe the approaches adopted to generate the runs submitted to ImageCLEFPhoto 2009 with an aim to promote document diversity in the rankings. Four of our runs are text based approaches that employ textual statistics extracted from the captions of images, i.e. MMR [1] as a state of the art method for result diversification, two approaches that combine relevance information and clustering techniques, and an instantiation of Quantum Probability Ranking Principle. The fifth run exploits visual features of the provided images to re-rank the initial results by means of Factor Analysis. The results reveal that our methods based on only text captions consistently improve the performance of the respective baselines, while the approach that combines visual features with textual statistics shows lower levels of improvements.

Label-free SERS for natural product provenance

Introduction Natural product provenance is important in the food, beverage and pharmaceutical industries, for consumer confidence and with health implications. Raman spectroscopy has powerful molecular fingerprint abilities. Surface Enhanced Raman Spectroscopy’s (SERS) sharp peaks allow distinction between minimally different molecules, so it should be suitable for this purpose. Methods Naturally caffeinated beverages with Guarana extract, coffee and Red Bull energy drink as a synthetic caffeinated beverage for comparison (20 µL ea.) were reacted 1:1 with Gold nanoparticles functionalised with anti-caffeine antibody (ab15221) (10 minutes), air dried and analysed in a micro-Raman instrument. The spectral data was processed using Principle Component Analysis (PCA). Results The PCA showed Guarana sourced caffeine varied significantly from synthetic caffeine (Red Bull) on component 1 (containing 76.4% of the variance in the data). See figure 1. The coffee containing beverages, and in particular Robert Timms (instant coffee) were very similar on component 1, but the barista espresso showed minor variance on component 1. Both coffee sourced caffeine samples varied with red Bull on component 2, (20% of variance). ************************************************************ Figure 1 PCA comparing a naturally caffeinated beverage containing Guarana with coffee. ************************************************************ Discussion PCA is an unsupervised multivariate statistical method that determines patterns within data. Figure 1 shows Caffeine in Guarana is notably different to synthetic caffeine. Other researchers have revealed that caffeine in Guarana plants is complexed with tannins. Naturally sourced/ lightly processed caffeine (Monster Energy, Espresso) are more inherently different than synthetic (Red Bull) /highly processed (Robert Timms) caffeine, in figure 1, which is consistent with this finding and demonstrates this technique’s applicability. Guarana provenance is important because it is still largely hand produced and its demand is escalating with recognition of its benefits. This could be a powerful technique for Guarana provenance, and may extend to other industries where provenance / authentication are required, e.g. the wine or natural pharmaceuticals industries.