Development and testing of allometric equations for estimating above-ground biomass of mixed-species environmental plantings

To quantify the impact that planting indigenous trees and shrubs in mixed communities (environmental plantings) have on net sequestration of carbon and other environmental or commercial benefits, precise and non-biased estimates of biomass are required. Because these plantings consist of several species, estimation of their biomass through allometric relationships is a challenging task. We explored methods to accurately estimate biomass through harvesting 3139 trees and shrubs from 22 plantings, and collating similar datasets from earlier studies, in non-arid (>300mm rainfallyear-1) regions of southern and eastern Australia. Site-and-species specific allometric equations were developed, as were three types of generalised, multi-site, allometric equations based on categories of species and growth-habits: (i) species-specific, (ii) genus and growth-habit, and (iii) universal growth-habit irrespective of genus. Biomass was measured at plot level at eight contrasting sites to test the accuracy of prediction of tonnes dry matter of above-ground biomass per hectare using different classes of allometric equations. A finer-scale analysis tested performance of these at an individual-tree level across a wider range of sites. Although the percentage error in prediction could be high at a given site (up to 45%), it was relatively low (<11%) when generalised allometry-predictions of biomass was used to make regional- or estate-level estimates across a range of sites. Precision, and thus accuracy, increased slightly with the level of specificity of allometry. Inclusion of site-specific factors in generic equations increased efficiency of prediction of above-ground biomass by as much as 8%. Site-and-species-specific equations are the most accurate for site-based predictions. Generic allometric equations developed here, particularly the generic species-specific equations, can be confidently applied to provide regional- or estate-level estimates of above-ground biomass and carbon. © 2013 Elsevier B.V.

Susceptibility of Coconut Wood to Damage by Subterranean Termites (Isoptera: Mastotermitidae, Rhinotermitidae)

Two field trials were conducted with untreated coconut wood (“cocowood”) of varying densities against the subterranean termites Coptotermes acinaciformis (Froggatt) and Mastotermes darwiniensis Froggatt in northern Queensland, Australia. Both trials ran for 16 weeks during the summer months. Cocowood densities ranged from 256 kg/m3 to 1003 kg/m3, and the test specimens were equally divided between the two termite trial sites. Termite pressure was high at both sites where mean mass losses in the Scots pine sapwood feeder specimens were: 100% for C. acinaciformis and 74.7% for M. darwiniensis. Termite species and cocowood density effects were significant. Container and position effects were not significant. Mastotermes darwiniensis fed more on the cocowood than did C. acinaciformis despite consuming less of the Scots pine than did C. acinaciformis. Overall the susceptibility of cocowood to C. acinaciformis and M. darwiniensis decreases with increasing density, but all densities (apart from a few at the high end of the density range) could be considered susceptible, particularly to M. darwiniensis. Some deviations from this general trend are discussed as well as implications for the utilisation of cocowood as a building resource.

Grazing impacts on the susceptibility of rangelands to wind erosion: The effects of stocking rate, stocking strategy and land condition

An estimated 110 Mt of dust is eroded by wind from the Australian land surface each year, most of which originates from the arid and semi-arid rangelands. Livestock production is thought to increase the susceptibility of the rangelands to wind erosion by reducing vegetation cover and modifying surface soil stability. However, research is yet to quantify the impacts of grazing land management on the erodibility of the Australian rangelands, or determine how these impacts vary among land types and over time. We present a simulation analysis that links a pasture growth and animal production model (GRASP) to the Australian Land Erodibility Model (AUSLEM) to evaluate the impacts of stocking rate, stocking strategy and land condition on the erodibility of four land types in western Queensland, Australia. Our results show that declining land condition, over stocking, and using inflexible stocking strategies have potential to increase land erodibility and amplify accelerated soil erosion. However, land erodibility responses to grazing are complex and influenced by land type sensitivities to different grazing strategies and local climate characteristics. Our simulations show that land types which are more resilient to livestock grazing tend to be least susceptible to accelerated wind erosion. Increases in land erodibility are found to occur most often during climatic transitions when vegetation cover is most sensitive to grazing pressure. However, grazing effects are limited during extreme wet and dry periods when the influence of climate on vegetation cover is strongest. Our research provides the opportunity to estimate the effects of different land management practices across a range of land types, and provides a better understanding of the mechanisms of accelerated erosion resulting from pastoral activities. The approach could help further assessment of land erodibility at a broader scale notably if combined with wind erosion models.

Shock tunnel testing of a Mach 6 hypersonic waverider

A waverider is a lifting body configuration whose upper surface is parallel to the free stream, and the lower surface aerodynamically so designed, that the resulting shock at the design Mach number, is always attached with the leading edge of the vehicle. This prevents spillage from high pressure (lower) surface to the low pressure (upper) surface.In the present study a conical waverider has been designed, fabricated and tested at Mach 6 in the IISc hypersonic shock tunnel HST2. The measurements show that the waverider has a lift to drag ratio of 4.28 at the designed Mach number. Exhaustive FEM and CFD studies are also carried out to complement the force measurements in the tunnel.

A randomized controlled trial protocol testing a decision support intervention for older patients with advanced kidney disease

Aim To assess the effectiveness of a decision support intervention using a pragmatic single blind Randomized Controlled Trial. Background Worldwide the proportion of older people (aged 65 years and over) is rising. This population is known to have a higher prevalence of chronic diseases including chronic kidney disease. The resultant effect of the changing health landscape is seen in the increase in older patients (aged ≥65 years) commencing on dialysis. Emerging evidence suggests that for some older patients dialysis may provide minimal benefit. In a majority of renal units non-dialysis management is offered as an alternative to undertaking dialysis. Research regarding decision-making support that is required to assist this population in choosing between dialysis or non-dialysis management is limited. Design. A multisite single blinded pragmatic randomized controlled trial is proposed. Methods Patients will be recruited from four Queensland public hospitals and randomizd into either the control or intervention group. The decision support intervention is multimodal and includes counselling provided by a trained nurse. The comparator is standard decision-making support. The primary outcomes are decisional regret and decisional conflict. Secondary outcomes are improved knowledge and quality of life. Ethics approval obtained November 2014. Conclusion This is one of the first randomized controlled trials assessing a decision support intervention in older people with advance chronic kidney disease. The results may provide guidance for clinicians in future approaches to assist this population in decision-making to ensure reduced decisional regret and decisional conflict.

Susceptibility to sulfuryl fluoride and lack of cross-resistance to phosphine in developmental stages of the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)

BACKGROUND Our aim was to ascertain the potential of sulfuryl fluoride (SF) as an alternative fumigant to manage phosphine-resistant pests. We tested the susceptibility of all life stages of red flour beetle, Tribolium castaneum (Herbst), to SF and assessed the presence of cross-resistance to this fumigant in phosphine-resistant strains of this species. RESULTS Analysis of dose–response data indicated that the egg was the stage most tolerant to SF under a 48 h exposure period. At LC50, eggs were 29 times more tolerant than other immature stages and adults, and required a relatively high concentration of 48.2 mg L−1 for complete mortality. No significant differences in tolerance to SF were observed among the three larval instars, pupae and adults, and all of these stages were controlled at a low concentration of 1.32 mg L−1. Phosphine-resistant strains did not show cross-resistance to SF. CONCLUSION Our research concluded that the current maximum registered rate of SF, 1500 gh m−3, is adequate to control all the post-embryonic life stages of T. castaneum over a 48 h fumigation period, but it will fail to achieve complete mortality of eggs, indicating the risk of some survival of eggs under this short exposure period. As there is no cross-resistance to SF in phosphine-resistant insects, it will play a key role in managing phosphine resistance in stored-grain insect pests. © 2014 Commonwealth of Australia. Pest Management Science © 2014 Society of Chemical Industry

Variation in the antimicrobial susceptibility of actinobacillus pleuropneumoniae isolates in a pig, within a batch of pigs, and among batches of pigs from one farm

Antimicrobial resistance in bacterial porcine respiratory pathogens has been shown to exist in many countries. However, little is known about the variability in antimicrobial susceptibility within a population of a single bacterial respiratory pathogen on a pig farm. This study examined the antimicrobial susceptibility of Actinobacillus pleuropneumoniae using multiple isolates within a pig and across the pigs in three different slaughter batches. Initially, the isolates from the three batches were identified, serotyped, and subsample genotyped. All the 367 isolates were identified as A. pleuropneumoniae serovar 1, and only a single genetic profile was detected in the 74 examined isolates. The susceptibility of the 367 isolates of A. pleuropneumoniae to ampicillin, tetracycline and tilmicosin was determined by a disc diffusion technique. For tilmicosin, the three batches were found to consist of a mix of susceptible and resistant isolates. The zone diameters of the three antimicrobials varied considerably among isolates in the second sampling. In addition, the second sampling provided statistically significant evidence of bimodal populations in terms of zone diameters for both tilmicosin and ampicillin. The results support the hypothesis that the antimicrobial susceptibility of one population of a porcine respiratory pathogen can vary within a batch of pigs on a farm.

High-pressure magnetic susceptibility of the intermediate valence system EuPd2Si2

The pressure dependence (0-7 kbar) of the magnetic susceptibility is reported for the intermediate valence system EuPd2Si2 in the temperature interval 77-300K. It is found that the thermally induced valence transition becomes more gradual on application of pressure The characteristic fluctuation temperature Tf, also seems to be pressure dependent.

Principals of audit: Testing, data and ‘implicated advocacy’

Historically, school leaders have occupied a somewhat ambiguous position within networks of power. On the one hand, they appear to be celebrated as what Ball (2003) has termed the ‘new hero of educational reform'; on the other, they are often ‘held to account’ through those same performative processes and technologies. These have become compelling in schools and principals are ‘doubly bound’ through this. Adopting a Foucauldian notion of discursive production, this paper addresses the ways that the discursive ‘field’ of ‘principal’ (within larger regimes of truth such as schools, leadership, quality and efficiency) is produced. It explores how individual principals understand their roles and ethics within those practices of audit emerging in school governance, and how their self-regulation is constituted through NAPLAN – the National Assessment Program, Literacy and Numeracy. A key effect of NAPLAN has been the rise of auditing practices that change how education is valued. Open-ended interviews with 13 primary and secondary school principals from Western Australia, South Australia and New South Wales asked how they perceived NAPLAN's impact on their work, their relationships within their school community and their ethical practice.