Integrated sub-regional planning informed by weighted spatial network models: The case of Jeddah sub-regional system

Existing Space Syntax methodologies provide the tools to measure the impact of proposed spatial changes, but are strongly dependant on the quality and availability of the spatial data. This becomes particularly more complex when major land use changes or development projects are proposed in a large region and there is no or vey little spatial layout data available for them. To counter this problem it is suggested that an 'integrated urban model' can be developed by using land use and demographic data to supplement the lack of spatial layout data and create a more realistic model for evaluating planning decisions. This paper explores the use of a 'weighted space syntax' model to contribute to the process of integrated urban planning for a large urban region in a major planning exercise in Jeddah, Saudi Arabia. The study aims at identifying the growth pattern and development potentials of the Jeddah Sub-regional system along with testing planning proposals for its growth over the next twenty years. The method for allocating the weighting to the segments of spatial networks by dividing the city into 'superblocks', identified by the foreground network and morphological similarities or spatial conditions such as existing municipal districts and major development boundaries. The weighting is then applied to the segments per unit length since longer segments have a higher probability of having a higher number of plots. The output is a spatial analysis impacted by the land use distribution, which adds the attraction or repulsion to movement generated by certain land uses to the spatial configuration and provides an accurate depiction of the functioning of the city. With this methodology we are able to estimate the impact of any number of projects of varying scales, at different time periods. This model has been integrated into the planning process through working with the lead planners in Jeddah at different stages of the project in both informative and evaluative modes. The result is an iterative, evidence-based approach and a collaborative framework for the planning and decision making, which could be adopted in future planning for Jeddah or elsewhere

Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse)

The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations

Using an analytical process to contextualise architectural prototypes for metro stations

In order to meet the pressures of a growing population and employment base, a developing city in the Middle East is planning a new public transport system to allow its sustainable growth. Introducing a new mode of public transport to a city that has a complex urban structure and a dependency on car use necessitates specific design responses to inform the station design process. This paper focuses on a study at the micro scale level that addresses the impact of evidence-based design on contextualised architectural station prototypes. Furthermore, it addresses the processes of working with an architectural design office in creating dynamic design iterations. The research here is presented from a perspective of the process of iterative analytical study to real time projects, reflecting on the balance between academia and practice. In order to construct a set of design principles to station locations, three layers of potential movement patterns are analysed using agents based modelling: movement from station exits; movement towards station entrances and background movement generated through the spatial accessibility values of the surrounding context. In that respect, each prototype station has been contextualised to its unique site. Design proposals developed by architectural teams are informed through fine grain analysis of urban features such as pavement widths and signage locations. The analyses also inform the landscape design process through the positioning of street furniture in relation to potential movement patterns as well as the effect of shading and public realm quality through option testing. To integrate stations within their contexts they must have simple entrances and clear orientation from the points of exit. Overall, the dynamic nature of agent based modelling allows for rapid design feedback to occur permitting an iterative process of design development and optimisation

City planning using integrated urban modeling Jeddah structure plan

This paper explores the use of weighted space syntax models to contribute to the process of integrated urban planning for Jeddah as part of a major planning project in the Saudi Arabia. The Municipality of Jeddah commissioned the production of an integrated suite of planning documents. These plans coordinate Strategic, Sub-Regional, Structural and Local plans across a citywide region and aim to provide a framework for sustainable urban growth and development over the next 20 years. This paper focuses on the space syntax methodologies used to aid urban planners to develop the Structure Plan and builds on the research used to develop the Sub-Regional Plan (Karimi et al, 2015). The Structure Plan studied how the urban structure of the city could accommodate the growth of population by about three million over the next 20 years. This included developing and testing a centres strategy to distribute population, employment and supporting facilities along with a public transport strategy for the city. For analysing the potential and requirements of the city, an Integrated Urban Model (IUM) was constructed to combine the spatial network with land use, population, employment and public transport. The aim of this model was to test the impact of changes in the distribution of population and employment. It also allowed the assessment of public transport alignments. The IUM is a key design tool for planning and optimising the relationships between population, employment and public transport. It was also used to provide a benchmarking methodology to compare options. Because the model links people to employment using the spatial network and public transport, the performance of options can be expressed in terms of benefits to the city's population

An evidence informed approach to developing an adaptable regeneration programme for declining informal settlements

This paper introduces a new approach to creating a regeneration framework for deteriorating unplanned settlements, or areas that often are regarded as ‘slums’. These areas are often in an irreversible cycle of deterioration, or ‘a vicious circle of decline’, which pushes the areas to worsen all the time. The main argument of this paper is how this process of decline could be stopped and reversed to create a positive cycle of change, or a ‘virtuous circle of improvement’. The guiding idea behind this transformation is that by understanding how a settlement grows, evolves and functions, we can identify an urban structure which shapes the internal functionality and external interactions of the settlement. This structure, which is strongly associated with movement, use, density, social interaction and other urban attributes, often suffers from multiple failures, which pushes the area into a descending cycle of decline. Fixing these fundamental problems will reverse the process of change, but it is a huge task and needs great resources that could not be provided in the beginning of the regeneration process. The paper argues that a highly adaptable regeneration programme, based on the most fundamental concepts of growth, could provide the basis for an incremental and sustainable process of regeneration for declining informal settlements. This entire methodology has been built on extensive research into the regeneration of the informal settlements of the city of Jeddah, in Saudi Arabia. By developing a series of analysis based on space syntax methods (Hillier & Hanson, 1989; Hillier, 1996), the essential spatial structures of the areas are established. A design process attempts to resolve the fundamental problems of these areas by improving the internal and external spatial structures. This is followed by an evidence‐informed distribution of land uses, densities, facilities and urban centres. In order to create flexibility and adaptability, a number of interchangeable regeneration scenarios are created that offer a range of variable solutions. A total redevelopment scenario, which is sometimes desired by some authorities, is complemented by at least four other scenarios, which seek different levels of intervention and physical change. The last of these scenarios is an improvement plan to only introduce the most efficient way of distributing and prioritising the regeneration efforts and external funding to optimise/enhance the living conditions and urban performance of the area. The product of this approach is not only a versatile and flexible plan for authorities, but it is intended to become a guide for residents, NGOs, charities, and everybody else, who is concerned with the well‐being of the people who live or work in declining informal settlements

Modelling Anopheles gambiae s.s. Population Dynamics with Temperature- and Age-Dependent Survival

Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical models of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and age dependent. We compared the performance of these models to that of a “standard” model ignoring age dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between models that incorporate age dependence and one that does not, and observe that age-dependent models consistently fitted the data better than the reference model. This highlights that including age dependence in the vector component of mosquito-borne disease models may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative model predictions for the An. gambiae malaria vector as well as for other disease vectors

A large-scale stochastic spatiotemporal model for Aedes albopictus-borne chikungunya epidemiology

Chikungunya is a viral disease transmitted to humans primarily via the bites of infected Aedes mosquitoes. The virus caused a major epidemic in the Indian Ocean in 2004, affecting millions of inhabitants, while cases have also been observed in Europe since 2007. We developed a stochastic spatiotemporal model of Aedes albopictus-borne chikungunya transmission based on our recently developed environmentally-driven vector population dynamics model. We designed an integrated modelling framework incorporating large-scale gridded climate datasets to investigate disease outbreaks on Reunion Island and in Italy. We performed Bayesian parameter inference on the surveillance data, and investigated the validity and applicability of the underlying biological assumptions. The model successfully represents the outbreak and measures of containment in Italy, suggesting wider applicability in Europe. In its current configuration, the model implies two different viral strains, thus two different outbreaks, for the two-stage Reunion Island epidemic. Characterisation of the posterior distributions indicates a possible relationship between the second larger outbreak on Reunion Island and the Italian outbreak. The model suggests that vector control measures, with different modes of operation, are most effective when applied in combination: adult vector intervention has a high impact but is short-lived, larval intervention has a low impact but is long-lasting, and quarantining infected territories, if applied strictly, is effective in preventing large epidemics. We present a novel approach in analysing chikungunya outbreaks globally using a single environmentally-driven mathematical model. Our study represents a significant step towards developing a globally applicable Ae. albopictus-borne chikungunya transmission model, and introduces a guideline for extending such models to other vector-borne diseases

Interleukin-3 greatly expands non-adherent endothelial forming cells with pro-angiogenic properties

Circulating endothelial progenitor cells (EPCs) provide revascularisation for cardiovascular disease and the expansion of these cells opens up the possibility of their use as a cell therapy. Herein we show that interleukin-3 (IL3) strongly expands a population of human non-adherent endothelial forming cells (EXnaEFCs) with low immunogenicity as well as pro-angiogenic capabilities in vivo, making their therapeutic utilisation a realistic option. Non-adherent CD133⁺ EFCs isolated from human umbilical cord blood and cultured under different conditions were maximally expanded by day 12 in the presence of IL3 at which time a 350-fold increase in cell number was obtained. Cell surfacemarker phenotyping confirmed expression of the hematopoietic progenitor cellmarkers CD133, CD117 and CD34, vascular cell markers VEGFR2 and CD31, dim expression of CD45 and absence of myeloid markers CD14 and CD11b. Functional experiments revealed that EXnaEFCs exhibited classical properties of endothelial cells (ECs), namely binding of Ulex europaeus lectin, up-take of acetylated-low density lipoprotein and contribution to EC tube formation in vitro. These EXnaEFCs demonstrated a pro-angiogenic phenotype within two independent in vivo rodent models. Firstly, a Matrigel plug assay showed increased vascularisation in mice. Secondly, a rat model of acute myocardial infarction demonstrated reduced heart damage as determined by lower levels of serum creatinine and a modest increase in heart functionality. Taken together, these studies show IL3 as a potent growth factor for human CD133⁺ cell expansion with clear pro-angiogenic properties (in vitro and in vivo) and thusmay provide clinical utility for humans in the future.Lachlan M. Moldenhauer, Michaelia P. Cockshell, Lachlan Frost, Kate A. Parham, Denis Tvorogov, Lih Y. Tan, Lisa M. Ebert, Katie Tooley, Stephen Worthley, Angel F. Lopez, Claudine S. Bonde

Heterogeneity of time delays determines synchronization of coupled oscillators

Network couplings of oscillatory large-scale systems, such as the brain, have a space-time structure composed of connection strengths and signal transmission delays. We provide a theoretical framework, which allows treating the spatial distribution of time delays with regard to synchronization, by decomposing it into patterns and therefore reducing the stability analysis into the tractable problem of a finite set of delay-coupled differential equations. We analyze delay-structured networks of phase oscillators and we find that, depending on the heterogeneity of the delays, the oscillators group in phase-shifted, anti-phase, steady, and non-stationary clusters, and analytically compute their stability boundaries. These results find direct application in the study of brain oscillations