Nickel Mining and the BWCA: A Question of Priorities

A conflict in potential land use of the Boundary Waters Canoe Area (BWCA) exists between those who wish to see the area open to mining and those who want it retained as a natural wilderness. A review of information available to the public which relates to possible nickel mining within the BWCA suggests that the BWCA itself in its natural state is a more valuable resource to the people of the United States than it is as a source for nickel. The high U.S. rate of consumption of nickel, our use of nickel in products in which it is non-essential, and the low nickel content of the rocks in the BWCA point to nickel mining in the BWCA as only a short-term, stopgap effort to maintain a steady supply of this metal for U.S. needs

The impact of mutation and gene conversion on the local diversification of antigen genes in African trypanosomes

Patterns of genetic diversity in parasite antigen gene families hold important information about their potential to generate antigenic variation within and between hosts. The evolution of such gene families is typically driven by gene duplication, followed by point mutation and gene conversion. There is great interest in estimating the rates of these processes from molecular sequences for understanding the evolution of the pathogen and its significance for infection processes. In this study, a series of models are constructed to investigate hypotheses about the nucleotide diversity patterns between closely related gene sequences from the antigen gene archive of the African trypanosome, the protozoan parasite causative of human sleeping sickness in Equatorial Africa. We use a hidden Markov model approach to identify two scales of diversification: clustering of sequence mismatches, a putative indicator of gene conversion events with other lower-identity donor genes in the archive, and at a sparser scale, isolated mismatches, likely arising from independent point mutations. In addition to quantifying the respective probabilities of occurrence of these two processes, our approach yields estimates for the gene conversion tract length distribution and the average diversity contributed locally by conversion events. Model fitting is conducted using a Bayesian framework. We find that diversifying gene conversion events with lower-identity partners occur at least five times less frequently than point mutations on variant surface glycoprotein (VSG) pairs, and the average imported conversion tract is between 14 and 25 nucleotides long. However, because of the high diversity introduced by gene conversion, the two processes have almost equal impact on the per-nucleotide rate of sequence diversification between VSG subfamily members. We are able to disentangle the most likely locations of point mutations and conversions on each aligned gene pair

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

National scale modelling to test UK population growth and infrastructure scenarios

This paper describes an exploratory methodology used to study the national scale issues of population growth and infrastructure implementation across the UK. The project was carried out for the Government Office for Science in 2015, focussing on two key questions: how could a “spatially driven” scenario provoke new thinking on accommodating forecast growth, and; what would be the impact of transport infrastructure investments within this context. Addressing these questions required the construction of a national scale spatial model that also needed to integrate datasets on population and employment. Models were analysed and profiled initially to identify existing relationships between the distribution of population and employment against the spatial network. Based on these profiles, an experimental methodology was used to firstly identify cities with the potential to accommodate growth, then secondly to allocate additional population proportionally. This raises important questions for discussion around which cities provide the benchmark for growth and why, as well as what the optimal spatial conditions for population growth may be, and how this growth should be accommodated locally. Later the model was used to study the impact of High Speed Rail. As these proposed infrastructure changes improve service (capacity, frequency, journey time), rather than creating new topological connections, the model was adapted to be able to produce time based catchments as an output. These catchments could then be expressed in terms of the workforce population within an hour of every city (a potential travel to work area), as well as the number of employment opportunities within an hour of every household

Modelling biodiversity trends in the montado (wood pasture) landscapes of the Alentejo, Portugal

Abstract Context Montados are dynamic agroforestry systems of southern Portugal, with high economic and ecological values. Changes in land use and cover have important implications for landscape-level biodiversity and its conservation. Objectives Our objectives were to evaluate the biodiversity values and trends in a montado system in the Alentejo, Portugal so as to inform landscape level conservation approaches. In doing so, we aimed to develop a replicable and robust approach drawing together field observation, expert opinion, and remote sensing to produce predictions relevant to land management planning. Methods Field sampling and subsequent analysis of data on the birds, butterflies and plants in eight distinct land covers allowed the identification of two principal habitat groupings of importance: ‘montado mosaic’ and ‘shrubland’. Morphological spatial pattern analysis was performed on Landsat-derived GIS habitat layers for 1984 and 2009, generating maps and statistics for change in the different landscape functional classes. In addition, we demonstrated how the modelling of ecotones between open and closed biomes can identify the preferred hunting grounds of the threatened Iberian lynx and black vulture, flagship species whose conservation provides benefits to the area’s wider biodiversity values. Results Total and core area of montado mosaics and shrubland increased over the 25 year period, whilst the amount of habitat connectivity declined in the case of shrubland. Considerable local variation in these trends highlighted targetable areas for conservation action (e.g. through agri-environment spending). Conclusions A rapid and robust approach was demonstrated, with potentially wider utility for biodiversity assessment and planning

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