ORCID Profile
0000-0002-4956-6895
Current Organisation
James Cook University Cairns Campus
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Surface Processes | Soil Sciences | Carbon Sequestration Science | Isotope Geochemistry
Sparseland, Permanent Grassland and Arid Zone Soils | Forest and Woodlands Soils | Forest and Woodlands Land Management |
Publisher: SAGE Publications
Date: 16-03-2021
Abstract: The volumes of various brain regions can be rapidly quantified using automated magnetic resonance imaging tools. While these appear to be useful at face value, their formal clinical utility is not yet understood, particularly for non-neuroradiologists and in patients presenting with suspected dementia. This study investigated the utility of an automated normative morphometry tool on determinations of brain atrophy by psychiatrists and radiologists in a tertiary hospital. Consecutive magnetic resonance scans ( n = 110) of patients referred with suspected neurodegenerative disorders were obtained retrospectively and rated by two neuroradiologists, two general radiologists and four psychiatrists over two sessions. First, conventional magnetic resonance sequences were shown. Then, morphometry colour-coded maps, which segmented T1-weighted magnetisation prepared rapid gradient echo images into brain regions and visualised these regions in colour according to their volumetric standard deviation from a normative population, were added to the second reading which occurred ⩾6 weeks later. Presence and laterality of atrophy in frontal, parietal and temporal lobes and hippoc al regions were measured using a digital checklist. The primary outcome of inter-rater agreement on atrophy was measured with Fleiss’ Kappa (κ). We also evaluated the accuracy of the atrophy ratings for differentiating post hoc diagnosis of subjective cognitive impairment, mild cognitive impairment and dementia. Agreement among all raters was fair in frontal lobe and moderate in other regions with conventional method (κ = 0.362–0.555). With morphometry, higher agreement was seen in all regions (κ = 0.551–0.654), reaching significant improvement in the frontal and temporal lobes. No significant improvement was seen within the various disciplines, except in frontal lobes rated by psychiatrists. Accuracy of atrophy ratings on determining post hoc diagnosis was significantly improved for distinguishing subjective cognitive impairment versus dementia. In routine clinical assessment, automated normative morphometry complements the determination of regional atrophy and improves inter-rater agreement regardless of neuroradiology experience.
Publisher: Springer Science and Business Media LLC
Date: 31-10-2014
Publisher: MDPI AG
Date: 25-11-2019
DOI: 10.3390/RS11232777
Abstract: This study builds on fundamental knowledge of granular failure dynamics to develop a statistical and machine learning approach for characterization of a landslide. We demonstrate our approach for a rockslide using surface displacement data from a ground based radar monitoring system. The algorithm has three key components: (i) identification of a regime change point t 0 marking the departure from statistical invariance of the global velocity field, (ii) characterization of the clustering pattern formed by the velocity time series at t 0 , and (iii) classification of velocity patterns for t t 0 to deliver a measure of risk of failure from t 0 and estimates of the time of emergent and imminent risk of failure. Unlike the prevailing approach of analysing time series data from one or a few chosen locations, we make full use of data from all monitored points on the slope (here 1803). We do not make a priori assumptions on the monitored domain and base our characterization of the complex spatial patterns and associated dynamics only from the data. Our approach is informed by recent developments in the physics and micromechanics of failure in granular media and is configured to accommodate additional data on landslide triggers and other determinants of landslide risk readily.
Publisher: Wiley
Date: 28-03-2014
DOI: 10.1111/JTSA.12069
Publisher: Wiley
Date: 02-02-2022
DOI: 10.1111/AVJ.13142
Abstract: To investigate if modification of a gonadotrophin‐releasing hormone (GnRH) based protocol to synchronise oestrus in Bos indicus cattle will improve response rates to the first administration of GnRH and improve pregnancy rates to artificial insemination (AI). Randomised control study. Bos indicus heifers, nonlactating and lactating cows allocated to a GnRH‐18 treatment (n = 237) were treated with an intravaginal device (IVD) and cloprostenol (0.5 mg IM) on day −11 and on day 0 remaining animals in the GnRH‐7 treatment (n = 222) were administered an IVD and every animal was treated with GnRH (100 μg IM). On day 7, equine chorionic gonadotrophin (400 IU IM) and cloprostenol were administered and IVD's were removed. Animals detected in oestrus on day 9 were artificially inseminated while those not detected in oestrus were administered GnRH (100 μg IM) at 1700 hours and inseminated on day 10. Bulls were inserted 2 weeks after completion of AI and remained until day 65. The GnRH‐18 protocol increased the diameter of the largest follicle in the ovary on day 0, increased the percentage of new CL's induced after day 0 (46.3% vs 36.1%, for GnRH‐18 and GnRH‐7 P = 0.022), decreased circulating concentrations of progesterone on day 7 and increased odds of pregnancy to AI in heifers but not in nonlactating and lactating cows. Treatment with the GnRH‐18 compared to the GnRH‐7 protocol increased pregnancy rates to AI in heifers but not in nonlactating or lactating cows.
Publisher: Wiley
Date: 23-03-2023
Abstract: In Queensland, where a person experiences a major disturbance in their mental capacity, and is at risk of serious harm to self and others, an emergency examination authority (EEA) authorises Queensland Police Service (QPS) and Queensland Ambulance Service (QAS) to detain and transport the person to an ED. In the ED, further detention for up to 12 h is authorised to allow the examination to be completed. Little published information describes these critical patient encounters. Queensland's Public Health Act (2005) , amended in 2017, mandates the use of the approved EEA form. Data were extracted from a convenience s le of 942 EEAs including: (i) patient age, sex, address (ii) free text descriptions by QPS and QAS officers of the person's behaviour and any serious risk of harm requiring urgent care (iii) time examination period commenced and (iv) outcome upon examination. Of 942 EEA forms, 640 (68%) were retrieved at three ‘larger central’ hospitals and 302 (32%) at two ‘smaller regional’ hospitals in non‐metropolitan Queensland. QPS initiated 342 (36%) and QAS 600 (64%) EEAs for 486 (52%) males, 453 (48%) females and two intersexes ( %), aged from 9 to 85 years (median 29 years, 17% aged years). EEAs commonly occurred on weekends (32%) and between 2300 and midnight (8%), characterised by ‘drug and/or alcohol issues’ (53%), ‘self‐harm’ (40%), ‘patient aggression’ (25%) and multiple prior EEAs (23%). Although information was incomplete, most patients (78%, n = 419/534) required no inpatient admission. EEAs furnish unique records for evaluating the impacts of Queensland's novel legislative reforms.
Publisher: Wiley
Date: 28-02-2021
DOI: 10.1111/JTSA.12584
Abstract: The periodogram is a widely used tool to analyze second order stationary time series. An attractive feature of the periodogram is that the expectation of the periodogram is approximately equal to the underlying spectral density of the time series. However, this is only an approximation, and it is well known that the periodogram has a finite s le bias, which can be severe in small s les. In this article, we show that the bias arises because of the finite boundary of observation in one of the discrete Fourier transforms which is used in the construction of the periodogram. Moreover, we show that by using the best linear predictors of the time series over the boundary of observation we can obtain a ‘complete periodogram’ that is an unbiased estimator of the spectral density. In practice, the ‘complete periodogram’ cannot be evaluated as the best linear predictors are unknown. We propose a method for estimating the best linear predictors and prove that the resulting ‘estimated complete periodogram’ has a smaller bias than the regular periodogram. The estimated complete periodogram and a tapered version of it are used to estimate parameters, which can be represented in terms of the integrated spectral density. We prove that the resulting estimators have a smaller bias than their regular periodogram counterparts. The proposed method is illustrated with simulations and real data.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2017
DOI: 10.1038/S41598-017-00081-3
Abstract: Singapore is a high-income country in a region with a high prevalence of tuberculosis. The Singapore Tuberculosis (TB) Elimination Program (STEP) was set up in 1997, and the better surveillance and clinical management practices initiated under STEP led to a decade-long decline in the incidence levels. However, incidence rates started to rise again since 2008. The reasons for this rise are unclear. This study involved a spatial analysis of the epidemiology of TB among Singapore residents. More than 30 000 cases reported during 1995–2011 and their residential addresses were analysed for spatial risk and spatial clustering, using spatial point pattern methodology. The principal factor responsible for the increasing resident TB incidence in Singapore is the changing age profile of the population. In particular the burgeoning population aged above 65 years accounts for the increase in reported cases. Singapore’s population has one of the world’s lowest fertility and mortality rates, and the elderly population is projected to grow substantially over the next few decades. Tuberculosis rates may therefore continue to rise even with static or improving case management and surveillance.
Publisher: Informa UK Limited
Date: 10-11-2018
Publisher: Wiley
Date: 2016
DOI: 10.1002/STA4.125
Publisher: Springer Science and Business Media LLC
Date: 15-10-2018
DOI: 10.1038/S41598-018-33666-7
Abstract: In chronic obstructive pulmonary disease (COPD), loss of computed tomography (CT)-measured intercostal mass correlates with spirometric severity. Intercostal muscle ultrasound offers a repeatable and radiation-free alternative, however requires validation. We aimed to determine the reliability of parasternal intercostal muscle ultrasound, and the concurrent validity of parasternal ultrasound with clinicometric parameters. Twenty stable COPD patients underwent ultrasound measurement of thickness and echogenicity of 2 nd and 3 rd parasternal intercostal muscles, dominant pectoralis major and quadriceps, and diaphragm thickness spirometry and chest CT. Intra-rater intraclass correlation (ICC) for ultrasound intercostal thickness was 0.87–0.97 depending on site, with echogenicity ICC 0.63–0.91. Inter-rater ICC was fair to excellent. Ultrasound intercostal thickness moderately correlated with FEV 1 % predicted (r = 0.33) and quadriceps thickness (r = 0.31). Echogenicity correlated negatively with FEV 1 % predicted (r = −0.32). CT-measured lateral intercostal mass correlate negatively with parasternal ultrasound intercostal thickness. These data confirm ultrasound of parasternal intercostal musculature is reproducible. Lower intercostal muscle quantity and quality reflects greater COPD spirometric severity. This novel tool may have biomarker potential for both the systemic effects of COPD on muscle as well as local disruption of respiratory mechanics. The negative correlation between CT and ultrasound measurements may reflect complex site-dependent interactions between respiratory muscles and the chest wall.
Publisher: Elsevier BV
Date: 04-2022
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2021
End Date: 12-2023
Amount: $401,000.00
Funder: Australian Research Council
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