Using systems thinking to assess the functioning of an "Age-Friendly City" governance network in Australia.

Age-Friendly Cities (AFC) is a framework for promoting healthy ageing through local actions. We use systems thinking to assess potential outcomes of actions to support older people's mobility, undertaken within an AFC commitment in Greater Sydney. Interviews with 20 informants involved in providing space, infrastructure, or services that affect how older people get around were analysed using causal loop diagrams (CLDs). Four approaches to support older people's mobility were identified and situated to the Multiple Governance Framework: land use, open and public space, supplementary transport, and community transport. Analysis revealed potential for unwanted consequences associated with each, which can be generalised into three generic potential outcomes for other jurisdictions to consider. A recommendation from this research is for policy actors to examine feedback interactions between actions so that they can foresee a wider range of outcomes and take defensive action against those unwanted. By situating CLDs within the Multiple Governance Framework, this research not only identifies what to look for, in terms of potential outcomes, but also where to look, in terms of the level of decision-making. This research offers a new way to assess the functioning of AFC governance networks by their collective outcomes and challenges the standards for the evaluation of AFC.

This study uses systems thinking to assess policy actions for supporting older people's transportation mobility in Greater Sydney. These policy actions pertain to land use, open and public space, supplementary transport, and community transport. Analysis revealed the potential for unwanted consequences, which result from different actions undermining one another, systemic constraints, and failure to account for small, but important, details.

Cool Communities-Urban Density, Trees, and Health.

A move towards more compact and climate-resilient cities is being encouraged around the world. As part of these plans, there is a need to manage the potential conflict between increasing urban densities and the extent of tree canopy in cities. Reductions in tree canopy are a major contributor to the urban heat island (UHI) effect, which will act to reduce rather than increase climate resilience in many cities. A systems thinking approach called Collaborative Conceptual Modelling was used to study the interaction between urban infill, tree canopy, and human health in Perth, Australia. The results indicated that under current planning policies and development practices, the behaviour of the system is dominated by the drive towards higher housing densities. While this may result in the attainment of urban infill targets, it is likely to lead to a reduction in tree canopy, higher temperatures, and a decrease in a range of other benefits provided by trees. Recommended actions to overcome this behaviour were determined by the identification of leverage points in the system. These included a shift to a sustainable development paradigm that places greater value on the environmental and social benefits provided by trees and a greater emphasis on a climate-resilient future. Market and legislative mechanisms should be integrated into the city's greening strategy and development plans to ensure the protection of existing trees and the inclusion of new trees on public and private land.

A role for low-order system dynamics models in urban health policy making.

Cities are complex adaptive systems whose responses to policy initiatives emerge from feedback interactions between their parts. Urban policy makers must routinely deal with both detail and dynamic complexity, coupled with high levels of diversity, uncertainty and contingency. In such circumstances, it is difficult to generate reliable predictions of health-policy outcomes. In this paper we explore the potential for low-order system dynamics (LOSD) models to make a contribution towards meeting this challenge. By definition, LOSD models have few state variables (≤5), illustrate the non-linear effects caused by feedback and accumulation, and focus on endogenous dynamics generated within well-defined boundaries. We suggest that experience with LOSD models can help practitioners to develop an understanding of basic principles of system dynamics, giving them the ability to 'see with new eyes'. Because efforts to build a set of LOSD models can help a transdisciplinary group to develop a shared, coherent view of the problems that they seek to tackle, such models can also become the foundations of 'powerful ideas'. Powerful ideas are conceptual metaphors that provide the members of a policy-making group with the a priori shared context required for effective communication, the co-production of knowledge, and the collaborative development of effective public health policies.

Urbanization, Extreme Events, and Health: The Case for Systems Approaches in Mitigation, Management, and Response.

Extreme events, both natural and anthropogenic, increasingly affect cities in terms of economic losses and impacts on health and well-being. Most people now live in cities, and Asian cities, in particular, are experiencing growth on unprecedented scales. Meanwhile, the economic and health consequences of climate-related events are worsening, a trend projected to continue. Urbanization, climate change and other geophysical and social forces interact with urban systems in ways that give rise to complex and in many cases synergistic relationships. Such effects may be mediated by location, scale, density, or connectivity, and also involve feedbacks and cascading outcomes. In this context, traditional, siloed, reductionist approaches to understanding and dealing with extreme events are unlikely to be adequate. Systems approaches to mitigation, management and response for extreme events offer a more effective way forward. Well-managed urban systems can decrease risk and increase resilience in the face of such events.

Human health and climate change: leverage points for adaptation in urban environments.

The design of adaptation strategies that promote urban health and well-being in the face of climate change requires an understanding of the feedback interactions that take place between the dynamical state of a city, the health of its people, and the state of the planet. Complexity, contingency and uncertainty combine to impede the growth of such systemic understandings. In this paper we suggest that the collaborative development of conceptual models can help a group to identify potential leverage points for effective adaptation. We describe a three-step procedure that leads from the development of a high-level system template, through the selection of a problem space that contains one or more of the group's adaptive challenges, to a specific conceptual model of a sub-system of importance to the group. This procedure is illustrated by a case study of urban dwellers' maladaptive dependence on private motor vehicles. We conclude that a system dynamics approach, revolving around the collaborative construction of a set of conceptual models, can help communities to improve their adaptive capacity, and so better meet the challenge of maintaining, and even improving, urban health in the face of climate change.

Seeing obesity as a systems problem.

Obesity has reached epidemic proportions in many countries and persists despite continuing efforts to find solutions. Such 'stubborn problems' often signal the influence of 'feedback systems'. In the case of the obesity epidemic, this possibility can be investigated using available system analysis tools. The investigation must begin with a study of the interplay between the full range of human and environmental factors. This paper outlines the nature of feedback and briefly discusses some of its management implications. A practical way to initiate a 'systems approach' to the obesity problem is suggested and four principles to guide the management of complex human- environment systems are presented.

Mind the sustainability gap.

Despite increasing efforts to reach sustainability, key global biophysical indicators such as climate change and biodiversity loss continue to deteriorate rather than improve. Ongoing failure to move towards sustainability calls into question the focus of current research and policy. We recommend two strategies for progress. First, sustainability must be conceptualized as a hierarchy of considerations, with the biophysical limits of the Earth setting the ultimate boundaries within which social and economic goals must be achieved. Second, transdisciplinary research programs must confront key normative questions facing modern consumer societies. The humanities should have a key role in such programs. Assisted by these strategies, ambitious targets that realistically reflect the biophysical limits of the life-support system of the Earth must be set and relentlessly worked towards.

In vivo determination of tumor oxygenation during growth and in response to carbogen breathing using 15C5-loaded alginate capsules as fluorine-19 magnetic resonance imaging oxygen sensors.

PURPOSE: The objective was to present a method for the repeated noninvasive measurement of tumor oxygenation (Po(2)) over the whole period of tumor growth. METHODS AND MATERIALS: A mixture of tumor homogenate (GH3 prolactinoma) and alginate capsules loaded with perfluoro-15-crown-5-ether (15C5) was injected into the flanks of Wistar Furth rats. The temporal behavior of tumor Po(2) was monitored between Day 1 and 26 after injection using fluorine-19 ((19)F) magnetic resonance imaging (MRI). In addition, the response of tumor Po(2) to modifiers of the tumor microenvironment (carbogen [95% O(2)/5% CO(2)], nicotinamide, and hydralazine) was investigated. RESULTS: An initial increase of tumor Po(2), probably reflecting neovascularization, followed by a decrease after Week 2, probably indicating tumor hypoxia or necrosis, were observed. The minimum and maximum average Po(2) +/- SEM observed were 3.3 +/- 2.0 mm Hg on Day 2 and 25.7 +/- 3.8 mm Hg on Day 13, respectively. Carbogen increased the tumor Po(2), whereas nicotinamide caused no significant change and hydralazine induced a significant decrease in tumor oxygenation. CONCLUSIONS: A preclinical method for the repeated noninvasive determination of tumor Po(2) was presented. It might help to investigate tumor physiology and the mechanisms of modifiers of the tumor microenvironment and their role in different therapeutic approaches.