University of the Sunshine Coast
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Stochastic strength rating of flexible airport pavements using construction data
No full textAirport pavements are designed to accommodate a broad range of aircraft loads, necessitating an airport-specific strength rating. Strength rating for a particular pavement is usually calculated deterministically, based on assumed pavement layer thicknesses and conservative values of stiffness for each layer of material. This research demonstrates a stochastic approach to flexible airport pavement strength determination via a case study on the Whitsunday Coast Airport. Construction records are statistically analysed and construction-based deterministic and stochastic strength ratings are compared to the design-based strength. The stochastic strength rating was generated by Monte Carlo simulation. The strength rating is found to vary greater with only slight differences in the probability of encountering understrength areas of pavement, and this case study is recommended as a template for the application to other airports. Also, 10,000 simulations were found to produce stable results and truncation of the distribution of construction factors had little impact on the resulting pavement strength distribution. Further research is recommended to better understand the distribution of asphalt modulus, as well as the direct engagement of design software for Monte Carlo simulation, in order to avoid the need for a pavement-specific prediction model
Long-Term Fire Regime Modifies Carbon and Nutrient Dynamics in Decomposing Eucalyptus pilularis Leaf Litter
No full textThe changes in fire regimes expected under climate change are likely to disrupt the biogeochemical cycling of carbon (C) and nutrients in forest ecosystems. Plant litter decomposition is a critical step in the terrestrial biogeochemical cycle, and is an important determinant of fire fuel load and forest C balance. We conducted a 277-day leaf litter decomposition experiment in an Australian eucalypt forest to test whether three contrasting, long-term fire regimes (no burning [NB], 4-yearly burning, and 2-yearly burning) were associated with different C and nutrient dynamics during litter decomposition. Fire regime had strong effects on many litter properties, including overall rates of decomposition and C loss, which were greatest in the NB treatment, suggesting that fire regime can modify the rate at which C is returned from litter to soil or the atmosphere. This has potentially important implications for soil C storage and atmospheric CO2 concentrations under a changing climate. High-frequency fire was associated with litter nutrient depletion and high microbial nutrient demand, but did not affect nutrient loss rates from decomposing litter, suggesting conservative use and retention of nutrients by the litter microbial biomass. These effects differed qualitatively between 2- and 4-yearly burning regimes, and they show how decadal-scale increases in fire frequency might contribute to soil nutrient depletion by disrupting decomposition. Many effects of fire regime on litter properties throughout decomposition were sensitive to litter bag re-collection date, suggesting that seasonal factors moderate the effects of fire regime, and that the role of fire regime-altered litter chemistry in shaping decomposition may be secondary to that of fire regime-altered environmental variables. Together, our findings highlight the potential consequences of long-term increases in prescribed fire frequency for litter decomposition and the storage and cycling of C and nutrients in eucalypt forests, and reveal the specific importance of average burn frequency in this context
Propaganda and Public Pedagogy
No full textPropaganda and public pedagogy are brought together here to demonstrate how the two terms are related and what they mean for the future of critical education research once considered together. The two terms describe educational processes on a mass scale, with the suggestion that they are in fact describing “the same thing” to some large degree. The focus here is upon the United States context, especially between the turn of the 20th century and the present day. The context is important because it was central to how propaganda and public pedagogy have developed their contemporary evaluative semantics, with propaganda being “bad” and public pedagogy being “good”. Propaganda and education are rarely mentioned together, other than by propagandists, or in cases where propaganda is typically treated as a kind of cultural “swear word”. I conclude here some understanding of the techniques of propaganda, and more importantly an organised normative program, are required for public pedagogy to reach its stated aims
The effect of overwood competition on the long-term survival, growth and stocking of underplanted tree species in logged tropical rainforest in north Queensland, Australia
No full textEnrichment of selectively logged rainforest by planting seedlings of commercially valuable species is often recommended to improve productivity, ecological functioning, and biodiversity. However, the survival and subsequent growth of enrichment plantings depend on how they respond to competition from neighbours. For successful forest restoration or commercial forest management, the challenge is to determine appropriate frequencies and intensities of silvicultural interventions, principally competition reduction. In this study, we use long-term data (49–60 years) from four enrichment planting experiments established after selective logging and girdling of non-commercial trees in a tropical rainforest in north Queensland, Australia, to assess the effects of competition on the survival and growth of enrichment plantings. We found that residual overwood development severely reduced the survival, diameter and volume growth of two widely planted rainforest species - Flindersia brayleyana (Rutaceae) and Agathis robusta (Araucariaceae). Both species responded well to overstory removal, either as an initial treatment or thereafter. Use of Hegyi’s competition index confirmed the strong suppressive effect of neighbours. The most abundant competitor was the fast-growing, early-secondary species Acacia aulacocarpa, which only became apparent after cessation of silvicultural treatments, 7 years after planting. Our results reaffirm the importance of an initial or early-age removal of the competing overstory for the success of enrichment planting. Further silvicultural treatments may be required for extended periods to control excessively increased overwood basal area and to remove late emerging pioneer or early secondary species
Camera traps are an effective method for identifying individuals and determining the sex of spotted-tailed quolls (Dasyurus maculatus gracilis)
No full textWe compared two bait station techniques for determining the sex and identifying individual spotted-tailed quolls (Dasyurus maculatus gracilis) using images taken by camera traps. One method used bait in a plastic mesh bag and the other was a new method using a raised bait canister to entice the quolls to stand on their hind legs and present their ventral surface to the camera. Individuals were identified from multiple images of their unique spot pattern, and sex was determined from ventral images. The bait bag method was better for detecting quolls and both methods performed similarly in allowing observers to identify individuals from images. However, the bait canister method was superior for determining sex of individuals. Using this new bait canister method, individual identification was possible in 202 out of 206 detection events and the sex of 81% (47 of 58) of identified individuals was confidently assigned from multiple detections. This bait station design can therefore provide additional data on individual quolls and reduces the need for more invasive live-trapping techniques. This methodology could be adapted for other mammals in Australia and worldwide
Digital technology and outdoor experiential learning
No full textAny use or non-use of digital technology in outdoor experiential learning requires critical examination. Digital technology can undermine the aim of being outdoors, but it can also create opportunities to enhance outdoor learning experiences. This paper presents a conceptual framework, based on a systematic review of the literature, that facilitators can use to think critically about their use (or non-use), of digital technology in outdoor experiential learning. The three key parts of the framework are pedagogical considerations, affordances of digital technology and consequences of decisions. The framework is designed to help facilitators of outdoor experiential learning make informed decisions or retrospectively review the decisions they made about the use (or non-use) of digital technology. The strength of the framework is that it encourages facilitators to engage in the critical evaluation of the intended and unintended consequences of digital technology use (or non-use) in outdoor experiential learning
Brain GABA levels are reduced in alcoholic liver disease: A proton magnetic resonance spectroscopy study
No full textBackground and aims: Baclofen, a selective γ-aminobutyric acid (GABA) B receptor agonist, has emerged as a potential treatment for alcohol use disorder with much unexplained variation in response to treatment efficacy and dose regimen. Several positive studies include patients with alcoholic liver disease (ALD) and/or history of heavy drinking. The aim of this paper was to examine the association of cortical GABA+ concentration with severity of liver disease (including markers of liver injury) and other clinical characteristics in alcohol patients. Methods: Proton magnetic resonance spectroscopy ( 1 H-MRS), from the parietal lobe, was analyzed to yield absolute concentration of GABA in 24 alcohol-dependent individuals. Diagnosis of ALD, markers of liver injury, severity of liver disease (Model for End-Stage Liver Disease [MELD]), and alcohol history were assessed. Covariates included concurrent medication, age, and recent alcohol consumption. Results: Multiple linear regression revealed that GABA+ concentration was significantly predicted by MELD scores (F = 5.02, R 2 = 0.59, P = 0.01; MELD: B = −0.63, P = 0.02), when controlling for covariates concurrent medication, age, and recent alcohol consumption. Conclusion: Severity of ALD is associated with lower cortical concentrations of GABA+. These results may explain variations in response to the GABA B agonist, baclofen, in the alcohol-dependent population
Prediction of macronutrients in plant leaves using chemometric analysis and wavelength selection
No full textPurpose:
Fast and real-time prediction of leaf nutrient concentrations can facilitate decision-making for fertilisation regimes on farms and address issues raised with over-fertilisation. Cacao (Theobroma cacao L.) is an important cash crop and requires nutrient supply to maintain yield. This project aimed to use chemometric analysis and wavelength selection to improve the accuracy of foliar nutrient prediction.
Materials and methods:
We used a visible-near infrared (400–1000 nm) hyperspectral imaging (HSI) system to predict foliar calcium (Ca), potassium (K), phosphorus (P) and nitrogen (N) of cacao trees. Images were captured from 95 leaf samples. Partial least square regression (PLSR) models were developed to predict leaf nutrient concentrations and wavelength selection was undertaken.
Results and discussion:
Using all wavelengths, Ca (R2CV = 0.76, RMSECV = 0.28), K (R2CV = 0.35, RMSECV = 0.46), P (R2CV = 0.75, RMSECV = 0.019) and N (R2CV = 0.73, RMSECV = 0.17) were predicted. Wavelength selection increased the prediction accuracy of Ca (R2CV = 0.79, RMSECV = 0.27) and N (R2CV = 0.74, RMSECV = 0.16), while did not affect prediction accuracy of foliar K (R2CV = 0.35, RMSECV = 0.46) and P (R2CV = 0.75, RMSECV = 0.019).
Conclusions:
Visible-near infrared HSI has a good potential to predict Ca, P and N concentrations in cacao leaf samples, but K concentrations could not be predicted reliably. Wavelength selection increased the prediction accuracy of foliar Ca and N leading to a reduced number of wavelengths involved in developed models
Health care professionals talking: Are services for young adults with type 1 diabetes fit for purpose?
No full textIntroduction:
The challenges of becoming a mature adult may distract young adults with type 1 diabetes from disease self‐management, increasing risks for premature morbidity and mortality. Despite the importance of young adults with type 1 diabetes engaging with preventative diabetes‐related health care services, few studies report health care professionals' experiences and perceptions of the support that is available, including during the period of transition. This study sought to determine these factors across diverse contexts in one health jurisdiction.
Methods:
This qualitative study was undertaken in New South Wales, Australia. Recruitment was based on a snowball sampling technique, which began with members of an established diabetes service group. Data were collected by individual semistructured interviews with 16 health care professionals, most of whom were registered nurses (75%), working at differing levels of expertise and responsibility across metropolitan and regional/rural areas. Data were analysed using thematic analyses.
Results:
Participants overwhelmingly recognized the time and care needed to support young adults with type 1 diabetes to prepare them for adult self‐management and to work with adult diabetes services, and the importance of youth‐friendly services. They reported shortfalls and inequitous distribution in services for these young adults. Two themes, addressing the present and future possibilities, expressed their perceptions of services for this population: working with what is available and mapping a route to better services.
Conclusion:
Findings identify opportunities for development in the planning and provision of specialist multidisciplinary health care support for this population. New ideas are needed for policy and practice innovation and for the infrastructure to facilitate this, to ensure that young adults with type 1 diabetes have access to consistent and coordinated diabetes health care services, particularly in nonmetropolitan settings
The reproducibility and responsiveness of subjective assessment of upper limb associated reactions in people with acquired brain injury during walking
No full textObjective:
The aim of this study is to determine inter-rater, test–retest and intra-rater reproducibility and responsiveness of subjective assessment of upper limb associated reactions in people with acquired brain injury using (1) the ‘Qualifiers Scale’ of the International Classification of Functioning, Disability and Health Framework, and (2) visually estimated elbow flexion angle during walking.
Design:
Observational study.
Setting:
A brain injury rehabilitation centre, Melbourne, Australia.
Subjects:
People with acquired brain injury and upper limb associated reactions and experienced neurological physiotherapists.
Main measures:
The Qualifiers Scale applied to individual upper limb joints and global associated reaction on a 5-point scale (0–4), a summed upper limb severity score and visually estimated elbow flexion angle.
Results:
A total of 42 people with acquired brain injury (mean age: 48.4 ± 16.5 years) were videoed walking at self-selected and fast speeds. A subset of 30 chronic brain injury participants (mean time post injury: 8.2 ± 9.3 years) were reassessed one week later for retest reproducibility. Three experienced neurological physiotherapists (mean experience: 22.7 ± 9.1 years) viewed these videos and subjectively rated the upper limb associated reactions. Strong-to-very strong test–retest, intra- and inter-rater reproducibility was found for elbow flexion angle (ICC > 0.86) and the Qualifiers Scale applied to global and individual upper limb joints (ICC > 0.60). Responsiveness of change from self-selected to fast walking speed (mean increase 0.46 m/s) was highest for elbow flexion angle (effect size = 0.83) and low-to-moderate for the Qualifiers Scale.
Conclusion:
Subjectively rated associated reactions during walking demonstrated strong reproducibility and moderate responsiveness to speed change. The Qualifiers Scale and elbow flexion angle can both subjectively quantify associated reactions during walking in a clinical setting