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Co-becoming Bawaka : towards a relational understanding of place/space
No full textWe invite readers to dig for ganguri (yams) at and with Bawaka, an Indigenous Homeland in northern Australia, and, in doing so, consider an Indigenous-led understanding of relational space/place. We draw on the concept of gurrutu to illustrate the limits of western ontologies, open up possibilities for other ways of thinking and theorizing, and give detail and depth to the notion of space/place as emergent co-becoming. With Bawaka as lead author, we look to Country for what it can teach us about how all views of space are situated, and for the insights it offers about co-becoming in a relational world.21 page(s
Radio planetary nebulae in the Small Magellanic Cloud
No full textWe present ten new radio continuum (RC) detections at catalogued planetary nebula (PN) positions in the Small Magellanic Cloud (SMC): SMP S6, LIN 41, LIN 142, SMP S13, SMP S14, SMP S16, J 18, SMP S18, SMP S19 and SMP S22. Additionally, six SMC radio PNe previously detected, LIN 45, SMP S11, SMP S17, LIN 321, LIN 339 and SMP S24 are also investigated (re-observed) here making up a population of 16 radio detections of catalogued PNe in the SMC. These 16 radio detections represent ∼15 % of the total catalogued PN population in the SMC. We show that six of these objects have characteristics that suggest that they are PN mimics: LIN 41, LIN 45, SMP S11, LIN 142, LIN 321 and LIN 339. We also present our results for the surface brightness—PN radius relation (Σ−D) of the SMC radio PN population. These are consistent with previous SMC and LMC PN measurements of the (Σ−D) relation.13 page(s
Optimal investment-consumption-insurance with random parameters
No full textThis paper discusses an optimal investment, consumption, and life insurance purchase problem for a wage earner in a complete market with Brownian information. Specifically, we assume that the parameters governing the market model and the wage earner, including the interest rate, appreciation rate, volatility, force of mortality, premium-insurance ratio, income and discount rate, are all random processes adapted to the Brownian motion filtration. Our modeling framework is very general, which allows these random parameters to be unbounded, non-Markovian functionals of the underlying Brownian motion. Suppose that the wage earner’s preference is described by a power utility. The wage earner’s problem is then to choose an optimal investment-consumption-insurance strategy so as to maximize the expected, discounted utilities from intertemporal consumption, legacy and terminal wealth over an uncertain lifetime horizon. We use a novel approach, which combines the Hamilton–Jacobi–Bellman equation and backward stochastic differential equation (BSDE) to solve this problem. In general, we give explicit expressions for the optimal investment-consumption-insurance strategy and the value function in terms of the solutions to two BSDEs. To illustrate our results, we provide closed-form solutions to the problem with stochastic income, stochastic mortality, and stochastic appreciation rate, respectively.26 page(s
Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi
No full textLead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead concentrations were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the period of leaded petrol use in Australian automobiles from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in ²⁰⁶Pb/²⁰⁷Pb ratios from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi ²⁰⁶Pb/²⁰⁷Pb ratios increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.10 page(s
Tuberculosis prevention must integrate technological and basic care innovation [letter to the editor]
No full text3 page(s
Terrestrial biosphere changes over the last 120 kyr
No full textA new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in ¹³C.23 page(s
Complexity of in-situ zircon U–Pb–Hf isotope systematics during arc magma genesis at the roots of a Cretaceous arc, Fiordland, New Zealand
No full textZircons from seventeen samples of Western Fiordland Orthogneiss (WFO) diorites and three samples of country rock (two schists and one Darran Suite diorite) from the lowermost exposed sections of the Median Batholith, Fiordland, New Zealand, were analysed for in-situ U–Pb and Hf-isotopes. The WFO represents the deeper levels of Early Cretaceous continental arc magmatism on the Pacific margin of Gondwana, marking the final stage of long-lived arc magmatism on the margin spanning the Palaeozoic. The WFO plutons were emplaced at high-P (mid to deep crust at c. 8–12 kbar) between 124 and 114 Ma. Minor very high-P (c. 18 kbar) WFO eclogite and omphacite granulite facies orthogneiss (Breaksea Orthogneiss) are inferred to have crystallised in the base of thickened crust at c. 124 Ma. Zircons from the Breaksea Orthogneiss are considered to be variably affected by Pb-loss due to emplacement of the adjacent (Malaspina) Pluton at c. 114 Ma. By identifying Pb-loss, magmatic ages were able to be inferred in respect to apparent Pb-loss ages. Hf isotope data for the WFO define an excursion to less radiogenic Hf isotope ratios with time, reflecting increased recycling of an old source component. Peaks at c. 555, 770 and 2480 Ma, determine the age spectra of inherited populations of zircons within the WFO. This contrasts with detrital zircon patterns in country rocks of the Takaka terrane, which include peaks at c. 465 Ma, and 1250–900 Ma that are absent in the WFO inheritance pattern. These results indicate a previously unrecognised Precambrian lower crustal component of New Zealand. Recycling of this lower crust became increasingly important as a source for the final stage or Mesozoic arc magmatism along this segment of the palaeo-Pacific margin of Gondwana.19 page(s
Regionalism, sub-regionalism and the politics of identity in Oceania
No full textRegional organization in Oceania has a history dating to the early post-war period while the rise of regional identities occurred somewhat later in the context of independence. This paper analyzes regionalization processes and accompanying discourses of regionalism relating to both pan-Pacific and more recent sub-regional developments. It pays particular attention to the dynamics of identity politics in the post-independence period and how these have played out in tensions within and between the varying exercises in regionalization.23 page(s
A Lagrangian-Eulerian finite element algorithm for advection-diffusion-reaction problems with phase change
No full textThis paper presents a particle-based Lagrangian–Eulerian algorithm for the solution of the unsteady advection–diffusion–reaction heat transfer equation with phase change. The algorithm combines a Lagrangian formulation for the advection + reaction problem with the Eulerian-based heat source method for the diffusion + phase change problem. The coupling between the Lagrangian and Eulerian subproblems is achieved with a phase change detector scheme based on a local latent heat balance and a consistent/conservative interpolation technique between Lagrangian particles and the Eulerian grid. This technique makes use of an auxiliary (finer) Eulerian grid that provides a simple and efficient method of tracking internal heterogeneities (e.g. phase boundaries), allows the use of higher order integration quadratures, and facilitates the implementation of multiscale techniques. The performance of the proposed algorithm is compared against one- and two-dimensional benchmark problems, i.e. pure rigid-body advection, isothermal and non-isothermal phase change, two-phase advective heat transfer and chemical reactions coupled with diffusion and advection. The numerical results confirm that the proposed solution method is accurate, oscillation-free and useful for and applicable to a wide range of fully coupled problems in science and engineering.27 page(s
Investment in urban heritage conservation in developing countries : concepts, methods and data
No full textMany towns and cities in countries of the developing world contain a historic centre comprising streets, buildings and traditional activities that have resisted the forces of modernisation. However, the inexorable pressures of population growth and urban expansion often pose a serious threat to these heritage assets which are seen as standing in the way of progress. This paper considers the application of the principles and methods of heritage economics to the evaluation of investment in the conservation of urban heritage in towns and cities in developing countries. The characteristics of cultural heritage in this environment are considered and the choices facing urban planners are discussed. The paper outlines the methodology of investment appraisal of projects aimed at adaptive re-use of urban heritage assets, with specific reference to the scarcity of appropriate data in the typical developing country situation. To illustrate the application of ex post investment appraisal methods to urban heritage conservation projects in Third World cities, two examples from studies in Macedonia and Jordan are discussed.6 page(s