Water conservation in Brisbane's residential landscapes : towards the optimisation of water in front garden design

One of the most critical issues that the world faces as it enters the new millennium is the provision of a continued supply of fresh water – the source of all life. The depletion problem of this resource through uneducated use is world-wide as well as being specific to Australia. This study centres on this issue in the Australian context with particular reference to gardening practices in Brisbane, the capital city of Queensland. The study examines methods by which fresh water can be saved through innovative garden design options. The cultural philosophies which underpin Brisbane’s suburban residential front gardens were investigated through an examination of literature, painting, and letters of the early settlement days in Australia and, in particular in Queensland. The findings were used to establish the theoretical framework for a qualitative study of seventy two Brisbane gardeners and their gardens. These gardens were selected from sites in a corridor of seven suburbs occupying a south-east segment of the city. The corridor included these components – an outward historical growth pattern, a range of socio-economic and cultural issues, varying soil types, topographical forms and a variety of residential forms and styles with a range of compass frontages. Each selected gardener was encouraged to ‘talk’ about the garden and its design and ‘making’ and the comments were analysed in the light of the author’s theoretical investigations. The results of this investigation provided an understanding of current gardening practices which also involve the use of 50-60 per cent of Brisbane’s domestic water on the garden. The findings suggest that Brisbane’s, and indeed, Australian gardens are based on philosophical notions that have Eurocentric foundations. Alternative and innovative water saving practices were explored and these techniques were modified to suit the design and construction of Brisbane gardens, whilst still satisfying the cultural values behind existing garden practices. The conclusions suggest that if gardeners are to be convinced about adopting water saving techniques, future garden designs must meet existing norms in terms of form and function as well as being able to conserve water

Can you hear what’s coming? Failure to replicate ERP evidence for phonological prediction

Prediction-based theories of language comprehension assume that listeners predict both the meaning and phonological form of likely upcoming words. In alleged event-related potential (ERP) demonstrations of phonological prediction, prediction-mismatching words elicit a phonological mismatch negativity (PMN), a frontocentral negativity that precedes the centroparietal N400 component. However, classification and replicability of the PMN has proven controversial, with ongoing debate on whether the PMN is a distinct component or merely an early part of the N400. In this electroencephalography (EEG) study, we therefore attempted to replicate the PMN effect and its separability from the N400, using a participant sample size (N = 48) that was more than double that of previous studies. Participants listened to sentences containing either a predictable word or an unpredictable word with/without phonological overlap with the predictable word. Preregistered analyses revealed a widely distributed negative-going ERP in response to unpredictable words in both the early (150–250 ms) and the N400 (300–500 ms) time windows. Bayes factor analysis yielded moderate evidence against a different scalp distribution of the effects in the two time windows. Although our findings do not speak against phonological prediction during sentence comprehension, they do speak against the PMN effect specifically as a marker of phonological prediction mismatch. Instead of an PMN effect, our results demonstrate the early onset of the auditory N400 effect associated with unpredictable words. Our failure to replicate further highlights the risk associated with commonly employed data-contingent analyses (e.g., analyses involving time windows or electrodes that were selected based on visual inspection) and small sample sizes in the cognitive neuroscience of language

Virtual patients designed for training against medical error: Exploring the impact of decision-making on learner motivation.

OBJECTIVES: Medical error is a significant cause of patient harms in clinical practice, but education and training are recognised as having a key role in minimising their incidence. The use of virtual patient (VP) activities targeting training in medical error allows learners to practice patient management in a safe environment. The inclusion of branched decision-making elements in the activities has the potential to drive additional generative cognitive processing and improved learning outcomes, but the increased cognitive load on learning risks negatively affecting learner motivation. The aim of this study is to better understand the impact that the inclusion of decision-making and inducing errors within the VP activities has on learner motivation. METHODS: Using a repeated study design, over a period of six weeks we provided undergraduate medical students at six institutions in three countries with a series of six VPs written around errors in paediatric practice. Participants were divided into two groups and received either linearly structured VPs or ones that incorporated branched decision-making elements. Having completed all the VPs, each participant was asked to complete a survey designed to assess their motivation and learning strategies. RESULTS: Our analysis showed that in general, there was no significant difference in learner motivation between those receiving the linear VPs and those who received branched decision-making VPs. The same results were generally reflected across all six institutions. CONCLUSIONS: The findings demonstrated that the inclusion of decision-making elements did not make a significant difference to undergraduate medical students' motivation, perceived self-efficacy or adopted learning strategies. The length of the intervention was sufficient for learners to overcome any increased cognitive load associated with branched decision-making elements being included in VPs. Further work is required to establish any immediate impact within periods shorter than the length of our study or upon achieved learning outcomes

Effect of pressure on the quantum spin ladder material IPA-CuCl3

Inelastic neutron scattering and bulk magnetic susceptibility studies of the quantum S=1/2 spin ladder system IPA-CuCl3 are performed under hydrostatic pressure. The pressure dependence of the spin gap $\Delta$ is determined. At $P=1.5$ GPa it is reduced to $\Delta=0.79$ meV from $\Delta=1.17$ meV at ambient pressure. The results allow us to predict a soft-mode quantum phase transition in this system at P$_\mathrm{c}\sim 4$ GPa. The measurements are complicated by a proximity of a structural phase transition that leads to a deterioration of the sample.Comment: 5 pages, 4 figure

High-frequency homogenization for periodic media

This article is available open access through the publisher’s website at the link below. Copyright @ 2010 The Royal Society.An asymptotic procedure based upon a two-scale approach is developed for wave propagation in a doubly periodic inhomogeneous medium with a characteristic length scale of microstructure far less than that of the macrostructure. In periodic media, there are frequencies for which standing waves, periodic with the period or double period of the cell, on the microscale emerge. These frequencies do not belong to the low-frequency range of validity covered by the classical homogenization theory, which motivates our use of the term ‘high-frequency homogenization’ when perturbing about these standing waves. The resulting long-wave equations are deduced only explicitly dependent upon the macroscale, with the microscale represented by integral quantities. These equations accurately reproduce the behaviour of the Bloch mode spectrum near the edges of the Brillouin zone, hence yielding an explicit way for homogenizing periodic media in the vicinity of ‘cell resonances’. The similarity of such model equations to high-frequency long wavelength asymptotics, for homogeneous acoustic and elastic waveguides, valid in the vicinities of thickness resonances is emphasized. Several illustrative examples are considered and show the efficacy of the developed techniques.NSERC (Canada) and the EPSRC

Late Ediacaran Redox Stability and Metazoan Evolution

The Neoproterozoic arrival of animals fundamentally changed Earth's biological and geochemical trajectory. Since the early description of Ediacaran and Cambrian animal fossils, a vigorous debate has emerged about the drivers underpinning their seemingly rapid radiation. Some argue for predation and ecology as central to diversification, whereas others point to a changing chemical environment as the trigger. In both cases, questions of timing and feedbacks remain unresolved. Through these debates, the last fifty years of work has largely converged on the concept that a change in atmospheric oxygen levels, perhaps manifested indirectly as an oxygenation of the deep ocean, was causally linked to the initial diversification of large animals. What has largely been absent, but is provided in this study, is a multi-proxy stratigraphic test of this hypothesis. Here, we describe a coupled geochemical and paleontological investigation of Neoproterozoic sedimentary rocks from northern Russia. In detail, we provide iron speciation data, carbon and sulfur isotope compositions, and major element abundances from a predominantly siliciclastic succession (spanning>1000 m) sampled by the Kel'tminskaya-1 drillcore. Our interpretation of these data is consistent with the hypothesis that the $pO_2$ threshold required for diversification of animals with high metabolic oxygen demands was crossed prior to or during the Ediacaran Period. Redox stabilization of shallow marine environments was, however, also critical and only occurred about 560 million years ago (Ma), when large motile bilaterians first enter the regional stratigraphic record. In contrast, neither fossils nor geochemistry lend support to the hypothesis that ecological interactions altered the course of evolution in the absence of environmental change. Together, the geochemical and paleontological records suggest a coordinated transition from low oxygen oceans sometime before the Marinoan (~635 Ma) ice age, through better oxygenated but still redox-unstable shelves of the early Ediacaran Period, to the fully and persistently oxygenated marine environments characteristic of later Ediacaran successions that preserve the first bilaterian macrofossils and trace fossils.Earth and Planetary SciencesOrganismic and Evolutionary Biolog

CD1d-restricted NKT cells: an interstrain comparison

CD1d-restricted Va14-Ja281 invariant abTCR1 (NKT) cells are well defined in the C57BL/6 mouse strain, but they remain poorly characterized in non-NK1.1-expressing strains. Surrogate markers for NKT cells such as abTCR1CD42CD82 and DX51CD31 have been used in many studies, although their effectiveness in defining this lineage remains to be verified. Here, we compare NKT cells among C57BL/6, NK1.1-congenic BALB/c, and NK1.1-congenic nonobese diabetic mice. NKT cells were identified and compared using a range of approaches: NK1.1 expression, surrogate phenotypes used in previous studies, labeling with CD1d/a-galactosylceramide tetramers, and cytokine production. Our results demonstrate that NKT cells and their CD4/CD8-defined subsets are present in all three strains, and confirm that nonobese diabetic mice have a numerical and functional deficiency in these cells. We also highlight the hazards of using surrogate phenotypes, none of which accurately identify NKT cells,and one in particular (DX51CD31) actually excludes these cells. Finally, our results support the concept that NK1.1 expression may not be an ideal marker for CD1d-restricted NKT cells, many of which are NK1.1-negative, especially within the CD41 subset and particularly in NK1.1-congenic BALB/c mice