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Biological toxicity of lanthanide elements on algae

- Tai, Pei Dong, Zhao, Qing, Su, Dan, Li, Peijun, Stagnitti, Frank

  • Authors: Tai, Pei Dong , Zhao, Qing , Su, Dan , Li, Peijun , Stagnitti, Frank
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Chemosphere Vol. 80, no. 9 (2010), p. 1031-1035
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  • Description: The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04 ± 0.61

Efficient prediction of deterministic size effects using the scaled boundary finite element method

- Ooi, Ean Tat, Yang, Zhenjun

  • Authors: Ooi, Ean Tat , Yang, Zhenjun
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Engineering Fracture Mechanics Vol. 77, no. 6 (2010), p. 985-1000
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  • Description: This paper develops an efficient numerical approach to predict deterministic size effects in structures made of quasi-brittle materials using the scaled boundary finite element method (SBFEM). Depending on the structure's size, two different SBFEM-based crack propagation modelling methodologies are used for fracture analyses. When the length of the fracture process zone (FPZ) in a structure is of the order of its characteristic dimension, nonlinear fracture analyses are carried out using the finite element-SBFEM coupled method. In large-sized structures, a linear elastic fracture mechanics (LEFM)-based SBFEM is used to reduce computing time due to small crack propagation length required to represent the FPZ in an equivalent nonlinear analysis. Remeshing is used in both methods to model crack propagation with crack paths unknown a priori. The resulting peak loads are used to establish the size effect laws. Three concrete structures were modelled to validate the approach. The predicted size effect is in good agreement with experimental data. The developed approach was found more efficient than the finite element method, at least in modelling LEFM problems and is thus an attractive tool for predicting size effect. © 2010 Elsevier Ltd.

How would global trade liberalization affect rural and regional incomes in Australia?

- Anderson, Kym, Giesecke, James, Valenzuela, Ernesto

  • Authors: Anderson, Kym , Giesecke, James , Valenzuela, Ernesto
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Australian Journal Of Agricultural And Resource Economics Vol. 54, no. 4 (2010), p. 389-406
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  • Description: For decades rural Australia has been discriminated against by industrial policies at home and agricultural protectionism abroad. While agricultural export taxation in poor countries had the opposite impact, recent reforms there mean that that offsetting effect on Australia has diminished. There has also been some re-instrumentation of rich-country farm policies away from trade measures. This paper draws on new evidence to examine whether Australian farmers and rural regions are still adversely affected by farm price-distortive policies abroad, using a global and a national economy-wide model. The results vindicate the continuing push by Australia's rural communities for multilateral agricultural trade liberalization.

Monosulfidic black ooze accumulations in sediments of the Geographe Bay area, Western Australia

- Ward, Nicholas, Bush, Richard, Burton, Edward, Appleyard, Steve, Wong, Stephen, Sullivan, Leigh, Cheeseman, Paul

  • Authors: Ward, Nicholas , Bush, Richard , Burton, Edward , Appleyard, Steve , Wong, Stephen , Sullivan, Leigh , Cheeseman, Paul
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Marine Pollution Bulletin Vol. 60, no. 11 (2010), p. 2130-2136
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  • Description: Mobilisation of sedimentary monosulfidic black ooze (MBO) may result in rapid deoxygenation and acidification of surface waters, and release of potentially toxic metals. This study examines the extent and nature of MBO accumulation in the Geographe Bay area, Western Australia. MBO accumulations were found to be widespread in benthic sediments of the Geographe Bay area with acid-volatile sulfide (AVS) contents as high as 320μmolg-1. The MBO materials often had unusually high dissolved sulfide (S-II) concentrations in their pore-waters (up to 610mgL-1) and elevated elemental sulfur (S0) contents (up to 51μmolg-1). Dissolved S-II is able to accumulate due to limited iron availability and S0 is largely its partial oxidation product. The availability of organic carbon and Fe limited MBO accumulation at many sites. A comparison of AVS and simultaneously extracted metal (SEM) concentrations has shown that metals are likely to be bound in sulfide complexes. © 2010 Elsevier Ltd.

Reactive trace element enrichment in a highly modified, tidally inundated acid sulfate soil wetland : East Trinity, Australia

- Keene, Annabelle, Johnston, Scott, Bush, Richard, Burton, Edward, Sullivan, Leigh

  • Authors: Keene, Annabelle , Johnston, Scott , Bush, Richard , Burton, Edward , Sullivan, Leigh
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Marine Pollution Bulletin Vol. 60, no. 4 (2010), p. 620-626
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  • Description: This study examines the abundance of trace elements in surface sediments of a former acid sulfate soil (ASS) wetland subjected to marine tidal inundation. Sediment properties of this highly modified study site are compared with those of an adjacent unmodified, intertidal mangrove forest. Whilst some trace elements (Al, Cd, Mn, Ni and Zn) were clearly depleted due to mobilisation and leaching in the previous oxic-acidic phase, other trace elements (As and Cr) displayed significant enrichment in the tidally inundated ASS. Many trace elements were strongly associated with the reactive Fe and acid volatile sulfide (AVS) fractions, suggesting that trace elements may be adsorbed to abundant reactive Fe phases or sequestered as sulfide minerals. These findings provide an important understanding of the fate and mobility of reactive iron, AVS and trace elements during tidal remediation of a formerly acidified Great Barrier Reef (GBR) catchment. © 2010 Elsevier Ltd.

Spatial differentiation of landscape values in the Murray River region of Victoria, Australia

- Zhu, Xuan, Pfueller, Sharron, Whitelaw, Paul, Winter, Caroline

  • Authors: Zhu, Xuan , Pfueller, Sharron , Whitelaw, Paul , Winter, Caroline
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Environmental Management Vol. 45, no. 5 (2010), p. 896-911
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  • Description: This research advances the understanding of the location of perceived landscape values through a statistically based approach to spatial analysis of value densities. Survey data were obtained from a sample of people living in and using the Murray River region, Australia, where declining environmental quality prompted a reevaluation of its conservation status. When densities of 12 perceived landscape values were mapped using geographic information systems (GIS), valued places clustered along the entire river bank and in associated National/State Parks and reserves. While simple density mapping revealed high value densities in various locations, it did not indicate what density of a landscape value could be regarded as a statistically significant hotspot or distinguish whether overlapping areas of high density for different values indicate identical or adjacent locations. A spatial statistic Getis-Ord Gi* was used to indicate statistically significant spatial clusters of high ! value densities or "hotspots". Of 251 hotspots, 40% were for single non-use values, primarily spiritual, therapeutic or intrinsic. Four hotspots had 11 landscape values. Two, lacking economic value, were located in ecologically important river red gum forests and two, lacking wilderness value, were near the major towns of Echuca-Moama and Albury-Wodonga. Hotspots for eight values showed statistically significant associations with another value. There were high associations between learning and heritage values while economic and biological diversity values showed moderate associations with several other direct and indirect use values. This approach may improve confidence in the interpretation of spatial analysis of landscape values by enhancing understanding of value relationships.

Household water use behavior: An integrated model

- Jorgensen, Bradley, Graymore, Michelle, O'Toole, Kevin

  • Authors: Jorgensen, Bradley , Graymore, Michelle , O'Toole, Kevin
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Journal of Environmental Management Vol. 91, no. 1 (2009), p. 227-236
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  • Description: Water authorities are dealing with the challenge of ensuring that there is enough water to meet demand in the face of drought, population growth and predictions of reduced supply due to climate change. In order to develop effective household demand management programs, water managers need to understand the factors that influence household water use. Following an examination and re-analysis of current water consumption behavioral models we propose a new model for understanding household water consumption. We argue that trust plays a role in household water consumption, since people will not save water if they feel others are not minimizing their water use (inter-personal trust). Furthermore, people are less likely to save water if they do not trust the water authority (institutional trust). This paper proposes that to fully understand the factors involved in determining household water use the impact of trust on water consumption needs investigation.

How do consumers define retail centre convenience?

- Clulow, Val, Reimers, Vaughan

  • Authors: Clulow, Val , Reimers, Vaughan
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Australasian Marketing Journal Vol. 17, no. 3 (2009), p. 125-132
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  • Description: The 1980s and 1990s have been labelled the ‘decades of convenience’. In spite of this, retail research has often indicated that when compared with other shopping motives, consumers assign relatively less importance to the convenience of a retail centre when deciding where to shop. Such counter-intuitive findings could be due to the way in which academics have defined retail centre convenience. This study develops and tests an alternative definition. Comprising 16 attributes, it represents a fourfold increase over any existing definition. Subsequent empirical analysis provides strong support for the alternative definition, with respondents indicating that 14 of the test attributes serve as convenience attributes. The failure of existing definitions to incorporate so many of these attributes is a likely explanation behind the counter-intuitive proposition that convenience often serves as a less-than-salient determinant of retail centre patronage.

Iron-monosulfide oxidation in natural sediments : Resolving microbially mediated S transformations using XANES, electron microscopy, and selective extractions

- Burton, Edward, Bush, Richard, Sullivan, Leigh, Hocking, Rosalie, Mitchell, David, Johnston, Scott, Fitzpatrick, Rob W., Raven, Mark, McClure, Stuart, Jang, Lingyun

  • Authors: Burton, Edward , Bush, Richard , Sullivan, Leigh , Hocking, Rosalie , Mitchell, David , Johnston, Scott , Fitzpatrick, Rob W. , Raven, Mark , McClure, Stuart , Jang, Lingyun
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Environmental Science and Technology Vol. 43, no. 9 (2009), p. 3128-3134
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  • Description: Iron-monosulfide oxidation and associated S transformations in a natural sediment were examined by combining selective extractions, electron microscopy and S K-edge X-ray absorption near-edge structure (XANES) spectroscopy. The sediment examined in this study was collected from a waterway receiving acid-sulfate soil drainage. It contained a high acid-volatile sulfide content (1031 μ mol g-1), reflecting an abundance of iron-monosulfide. The iron-monosulfide speciation in the initial sediment sample was dominated by nanocrystalline mackinawite (tetragonal FeS). At near-neutral pH and an O 2 partial pressure of ∼0.2 atm, the mackinawite was found to oxidize rapidly, with a half-time of 29 ± 2 min. This oxidation rate did not differ significantly (P < 0.05) between abiotic versus biotic conditions, demonstrating that oxidation of nanocrystalline mackinawite was not microbially mediated. The extraction results suggested that elemental S (S0 8) was a key intermediate S oxidation product. Transmission electron microscopy showed the S0 8 to be amorphous nanoglobules, 100-200 nm in diameter. The quantitative importance of S0 8 was confirmed by linear combination XANES spectroscopy, after accounting for the inherent effect of the nanoscale S0 8 particle-size on the corresponding XANES spectrum. Both the selective extraction and XANES data showed that oxidation of S0 8 SO4 2- was madiated by microbial activity. In addition to directly revealing important S transformations, the XANES results support the accuracy of the selective extraction scheme employed here. © 2009 American Chemical Society.

Nights at the airport

- Mills, Alice

  • Authors: Mills, Alice
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Nebula Vol. 6, no. 2 p. 174-176
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  • Description: A personal narrative is presented in which the author explains her experiences while waiting for a plane at the airport at night.
  • Description: 2003008013

Sorption of Arsenic(V) and Arsenic(III) to schwertmannite

- Burton, Edward, Bush, Richard, Johnston, Scott, Watling, Kym, Hocking, Rosalie, Sullivan, Leigh, Parker, Gretel

  • Authors: Burton, Edward , Bush, Richard , Johnston, Scott , Watling, Kym , Hocking, Rosalie , Sullivan, Leigh , Parker, Gretel
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Environmental Science and Technology Vol. 43, no. 24 (2009), p. 9202-9207
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  • Description: This study describes the sorption of As(V) and As(III) to schwertmannite as a function of pH and arsenic loading. In general, sorption of As(V) was greatest at low pH, whereas high pH favored the sorption of As(III). The actual pH of equivalent As(V) and As(III) sorption was strongly loading dependent, decreasing from pH ∼ 8.0 at loadings <120 mmolAs mol Fe -1 to pH ∼ 4.6 at a loading of 380 mmolAs molFe -1. Sorption isotherms for As(V) were characterized by strong partitioning to the schwertmannite solid-phase at low loadings and sorption capacities of 225-330 mmolAs(V) molFe -1 at high loadings. In contrast, the As(III) isotherms revealed a weak affinity for sorption of As(III) versus As(V) at low loadings yet a greater affinity for As(III) sorption compared with As(V) at high loadings (when pH > 4.6). Sorption of As(V) and As(III) caused significant release of SO 4 2- from within the schwertmannite solid-phase, without major degradation of the schwertmannite structure (as evident by X-ray diffraction and Raman spectroscopy). This can be interpreted as arsenic sorption via incorporation into the schwertmannite structure, rather than merely surface complexation at the mineral-water interface. The results of this study have important implications for arsenic mobility in the presence of schwertmannite, such as in areas affected by acidmine drainage and acid-sulfate soils. In particular, arsenic speciation, arsenic loading, and pH should be considered when predicting and managing arsenic mobility in schwertmanniterich systems. © 2009 American Chemical Society.

Verification of a numerical model for the prediction of low slope vertical slot fishway hydraulics.

- Barton, Andrew, Keller, Robert, Katopodis, Christos

  • Authors: Barton, Andrew , Keller, Robert , Katopodis, Christos
  • Date: 2009
  • Type: Text , Journal article
  • Relation: Australian Journal of Water Resources Vol. 13, no. 1 (2009), p. 53-60
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  • Description: A numerical model has been developed to predict the three-dimensional flow character within low scope vertical slot fishways (VSFs). The modek solves the three dimensional Reynolds averaged Navier-Stokes equations, closed with the renormalised k-e turbulence formulations. The model employs the volume of fluid method to deal with the free surface. Results are presented for velocities and surface elevations utilising two fishway designs from prototype and laboratory studies. The respective data from the studies are direct compared to the numerical model predictions forming the basis of verification. The model is shown to predict critical design velocities, slot flow characteristics, flow recirculation and water surface elevations well enough to be useful in low slope VSF design.

Diverse cytokine production by NKT cell subsets and identification of an IL-17-producing CD4-NK1.1- NKT cell population

- Coquet, Jonathan, Chakravarti, Sumone, Kyparissoudis, Konstantinos, McNab, Finlay, Pitt, Lauren, McKenzie, Brent, Berzins, Stuart, Smyth, Mark, Godfrey, Dale

HIV/AIDS in Vietnam : a gender analysis

- Nguyen, Huy, Saikia, Udoy

  • Authors: Nguyen, Huy , Saikia, Udoy
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Asian Social Science Vol. 4, no. 1 (2008), p. 89-123
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  • Description: Global statistics of HIV/AIDS infection reveals the disastrous effects of discrimination against women in the area of human health. Women’s vulnerability to HIV/AIDS reflects their wider social, economic and sexual disadvantages compared to their male counterpart. Although the gender context of HIV/AIDS has received a considerable attention recently, however, in case of Vietnam gender aspects of the epidemic have still been a neglected area of research. Little is known about how gender affects the epidemic as well as how the epidemic affects the life of women. This paper reveals that the gender context of HIV/AIDS epidemic in Vietnam has a much complex reality. Institutions, social norms and opportunity structures, of which “Doi Moi” [Renovation] has become an integral part, combine to create new norms and conditions put women more vulnerable to HIV/AIDS. A gendered strategy is crucial in order to successfully fight against the growing HIV/AIDS epidemic

Iron-sulfide and trace element behaviour in sediments of Coombabah Lake, southern Moreton Bay (Australia)

- Burton, Edward, Sullivan, Leigh, Bush, Richard, Powell, Bernard

  • Authors: Burton, Edward , Sullivan, Leigh , Bush, Richard , Powell, Bernard
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Marine Pollution Bulletin Vol. 56, no. 7 (2008), p. 1353-1358
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  • Description: Iron-sulfide minerals in benthic sediments may sequester potentially toxic trace elements that are introduced to estuaries from natural and anthropogenic sources (Chapman et al., 1998, Morse and Luther, 1999, Simpson et al., 2002 and Teasdale et al., 2003). Understanding iron-sulfide formation in benthic sediments is therefore central to assessing the risk posed by sedimentary trace elements (Machado et al., 2004, Burton et al., 2005a and Burton et al., 2006a). This report provides a baseline description of sedimentary iron-sulfide and trace element behaviour in Coombabah Lake – a sub-tropical estuarine lake in southern Moreton Bay, Australia (Fig. 1).

Using the student perceptions of assessment questionnaire (SPAQ) to develop an assessment typology for science classes

- Dorman, Jeffrey, Waldrip, Bruce, Fisher, Darrell

  • Authors: Dorman, Jeffrey , Waldrip, Bruce , Fisher, Darrell
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Foundation Journal of Science Education Vol. 9, no. 1 (2008), p. 13-17
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  • Description: This article reports research conducted on students’ perceptions of assessment in science classes in Queensland and Western Australia. A specially developed instrument, the Student Perceptions of Assessment Questionnaire (SPAQ) which assesses Congruence with Planned Learning, Authenticity, Student Consultation, Transparency, and Diversity was used to collect data from 3,055 students. Hierarchical cluster analysis resulted in a four cluster solution being accepted. While one cluster of 799 students held positive perceptions of assessment, another cluster of 640 students held negative views. The SPAQ allows for a greater focus on classroom-based perceptions of assessment rather than crude external accountability measures that decontextualise classroom assessment.