ORCID Profile
0000-0002-1512-4255
Current Organisations
Baker Heart and Diabetes Institute
,
Monash University
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Publisher: American Physical Society (APS)
Date: 07-12-2020
Publisher: American Physical Society (APS)
Date: 17-12-2020
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.IJCARD.2012.12.093
Abstract: Atrial fibrillation (AF) represents an increasing public health challenge with profound social and economic implications. A comprehensive synthesis and review of the AF literature was performed. Overall, key findings from 182 studies were used to describe the indicative scope and impact of AF from an in idual to population perspective. There are many pathways to AF including advancing age, cardiovascular disease and increased levels of obesity/metabolic disorders. The reported population prevalence of AF ranges from 2.3%-3.4% and historical trends reflect increased AF incidence. Estimated life-time risk of AF is around 1 in 4. Primary care contacts reflect whole population trends: AF-related case-presentations increase from less than 0.5% in those aged 40 years or less to 6-12% for those aged 85 years or more. Globally, AF-related hospitalisations (primary or secondary diagnosis) showed an upward trend (from ~35 to over 100 admissions/10,000 persons) during 1996 to 2006. The estimated cost of AF is greater than 1% of health care expenditure and rising with hospitalisations the largest contributor. For affected in iduals, quality of life indices are poor and AF confers an independent 1.5 to 2.0-fold probability of death in the longer-term. AF is also closely linked to ischaemic stroke (3- to 5-fold risk), chronic heart failure (up to 50% develop AF) and acute coronary syndromes (up to 25% develop AF) with consistently worse outcomes reported with concurrent AF. Future projections predict at least a doubling of AF cases by 2050. AF represents an evolving, global epidemic providing considerable challenges to minimise its impact from an in idual to whole society perspective.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Springer Science and Business Media LLC
Date: 10-2020
DOI: 10.1140/EPJC/S10052-020-8223-0
Abstract: Inclusive and differential fiducial cross sections of the Higgs boson are measured in the $$H \\rightarrow ZZ^{*} \\rightarrow 4\\ell $$ H → Z Z ∗ → 4 ℓ ( $$\\ell = e,\\mu $$ ℓ = e , μ ) decay channel. The results are based on proton-proton collision data produced at the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector from 2015 to 2018, equivalent to an integrated luminosity of 139 $$\\hbox {fb}^{-1}$$ fb - 1 . The inclusive fiducial cross section for the $$H \\rightarrow ZZ^{*} \\rightarrow 4\\ell $$ H → Z Z ∗ → 4 ℓ process is measured to be $$\\sigma _\\mathrm {fid} = 3.28 \\,{\\pm }\\, 0.32$$ σ fid = 3.28 ± 0.32 fb, in agreement with the Standard Model prediction of $$\\sigma _\\mathrm {fid, SM} = 3.41 \\pm 0.18 $$ σ fid , SM = 3.41 ± 0.18 fb. Differential fiducial cross sections are measured for a variety of observables which are sensitive to the production and decay of the Higgs boson. All measurements are in agreement with the Standard Model predictions. The results are used to constrain anomalous Higgs boson interactions with Standard Model particles.
Publisher: IOP Publishing
Date: 08-2021
DOI: 10.1088/1748-0221/16/08/P08025
Abstract: Non-ionizing energy loss causes bulk damage to the silicon sensors of the ATLAS pixel and strip detectors. This damage has important implications for data-taking operations, charged-particle track reconstruction, detector simulations, and physics analysis. This paper presents simulations and measurements of the leakage current in the ATLAS pixel detector and semiconductor tracker as a function of location in the detector and time, using data collected in Run 1 (2010–2012) and Run 2 (2015–2018) of the Large Hadron Collider. The extracted fluence shows a much stronger | z |-dependence in the innermost layers than is seen in simulation. Furthermore, the overall fluence on the second innermost layer is significantly higher than in simulation, with better agreement in layers at higher radii. These measurements are important for validating the simulation models and can be used in part to justify safety factors for future detector designs and interventions.
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Abstract: Fiducial and differential cross-section measurements of W + W − production in association with at least one hadronic jet are presented. These measurements are sensitive to the properties of electroweak-boson self-interactions and provide a test of perturbative quantum chromodynamics and the electroweak theory. The analysis is performed using proton-proton collision data collected at $$ \sqrt{s} $$ s = 13 TeV with the ATLAS experiment, corresponding to an integrated luminosity of 139 fb − 1 . Events are selected with exactly one oppositely charged electron-muon pair and at least one hadronic jet with a transverse momentum of p T 30 GeV and a pseudorapidity of | η | 4 . 5. After subtracting the background contributions and correcting for detector effects, the jet-inclusive W + W − + ≥ 1 jet fiducial cross-section and W + W − + jets differential cross-sections with respect to several kinematic variables are measured. These measurements include leptonic quantities, such as the lepton transverse momenta and the transverse mass of the W + W − system, as well as jet-related observables such as the leading jet transverse momentum and the jet multiplicity. Limits on anomalous triple-gauge-boson couplings are obtained in a phase space where interference between the Standard Model litude and the anomalous litude is enhanced.
Publisher: American Physical Society (APS)
Date: 18-12-2020
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 11-2020
Publisher: Springer Science and Business Media LLC
Date: 10-2020
DOI: 10.1140/EPJC/S10052-020-8227-9
Abstract: Higgs boson properties are studied in the four-lepton decay channel (where lepton = e , $$\\mu $$ μ ) using 139 $$\\hbox {fb}^{-1}$$ fb - 1 of proton–proton collision data recorded at $$\\sqrt{s}=$$ s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio for $$H\\rightarrow ZZ^*$$ H → Z Z ∗ decay is measured to be $$1.34 \\pm 0.12$$ 1.34 ± 0.12 pb for a Higgs boson with absolute rapidity below 2.5, in good agreement with the Standard Model prediction of $$1.33 \\pm 0.08$$ 1.33 ± 0.08 pb. Cross-sections times branching ratio are measured for the main Higgs boson production modes in several exclusive phase-space regions. The measurements are interpreted in terms of coupling modifiers and of the tensor structure of Higgs boson interactions using an effective field theory approach. Exclusion limits are set on the CP-even and CP-odd ‘beyond the Standard Model’ couplings of the Higgs boson to vector bosons, gluons and top quarks.
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.IJCARD.2011.10.065
Abstract: Health outcomes associated with atrial fibrillation (AF) continue to be poor and standard management often does not provide clinical stability. The Standard versus Atrial Fibrillation spEcific managemenT studY (SAFETY) compares the efficacy of a post-discharge, nurse-led, multi-disciplinary programme to optimise AF management with usual care. SAFETY is a prospective, multi-centre, randomised controlled trial with blinded-endpoint adjudication. A target of 320 hospitalised patients with a chronic form of AF will be randomised (stratified by "rate" versus "rhythm" control) to usual post-discharge care or the SAFETY Intervention (SI). The SI involves home-based assessment, extensive clinical profiling and the application of optimal gold-standard pharmacology which is in idually tailored according to a "traffic light" framework based on clinical stability, risk profile and therapeutic management. The primary endpoint is event-free survival from all-cause death or unplanned readmission during 18-36 months follow-up. Secondary endpoints include rate of recurrent hospital stay, treatment success (i.e. maintenance of rhythm or rate control and/or application of anti-thrombotic therapy without a bleeding event) and cost-efficacy. With study recruitment to be completed in early 2012, the results of this study will be available in early 2014. If positive, SAFETY will represent a potentially cost-effective and readily applicable strategy to improve health outcomes in high risk in iduals discharged from hospital with chronic AF.
Publisher: American Physical Society (APS)
Date: 23-12-2020
Publisher: Springer Science and Business Media LLC
Date: 11-2020
Abstract: A search for new physics with non-resonant signals in dielectron and dimuon final states in the mass range above 2 TeV is presented. This is the first search for non-resonant signals in dilepton final states at the LHC to use a background estimate from the data. The data, corresponding to an integrated luminosity of 139 fb − 1 , were recorded by the ATLAS experiment in proton-proton collisions at a center-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV during Run 2 of the Large Hadron Collider. The benchmark signal signature is a two-quark and two-lepton contact interaction, which would enhance the dilepton event rate at the TeV mass scale. To model the contribution from background processes a functional form is fit to the dilepton invariant-mass spectra in data in a mass region below the region of interest. It is then extrapolated to a high-mass signal region to obtain the expected background there. No significant deviation from the expected background is observed in the data. Upper limits at 95% CL on the number of events and the visible cross-section times branching fraction for processes involving new physics are provided. Observed (expected) 95% CL lower limits on the contact interaction energy scale reach 35.8 (37.6) TeV.
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 05-2021
Publisher: Informa UK Limited
Date: 2021
Publisher: IOP Publishing
Date: 07-2021
DOI: 10.1088/1748-0221/16/07/P07006
Abstract: The ATLAS Fast TracKer (FTK) was designed to provide full tracking for the ATLAS high-level trigger by using pattern recognition based on Associative Memory (AM) chips and fitting in high-speed field programmable gate arrays. The tracks found by the FTK are based on inputs from all modules of the pixel and silicon microstrip trackers. The as-built FTK system and components are described, as is the online software used to control them while running in the ATLAS data acquisition system. Also described is the simulation of the FTK hardware and the optimization of the AM pattern banks. An optimization for long-lived particles with large impact parameter values is included. A test of the FTK system with the data playback facility that allowed the FTK to be commissioned during the shutdown between Run 2 and Run 3 of the LHC is reported. The resulting tracks from part of the FTK system covering a limited η–ϕ region of the detector are compared with the output from the FTK simulation. It is shown that FTK performance is in good agreement with the simulation.
Publisher: Elsevier BV
Date: 06-2021
DOI: 10.51893/2021.2.OA7
Abstract: OBJECTIVE: We sought to examine the incidence of low litude ventricular fibrillation and its impact on successful cardioversion, duration of resuscitation, and survival to hospital discharge in patients with out-of-hospital cardiac arrest (OHCA). DESIGN: Retrospective analysis from a statewide registry. SETTING: Victoria, Australia. PARTICIPANTS: Consecutive initial ventricular fibrillation arrests with an emergency medical service (EMS)-attempted resuscitation between 1 February 2019 and 30 January 2020. MAIN OUTCOME MEASURES: Survival to hospital discharge, successful cardioversion, and duration of resuscitation. RESULTS: Of the 471 initial ventricular fibrillation arrests, 429 (91.1%) had sufficient electrocardiogram data for review. The median initial and final ventricular fibrillation litude did not differ (0.3 mV interquartile range [IQR], 0.2–0.5 mV). The final pre-shock litude was ≤ 0.1 mV (very fine) and ≤ 0.2 mV (fine) in 22.8% and 37.5% of cases respectively. In a multivariable analysis, only the time between emergency call and first defibrillation was associated with a low initial ventricular fibrillation litude ≤ 0.2 mV (adjusted odds ratio [aOR], 1.07 95% CI, 1.02–1.13 P = 0.004). After adjustment for arrest factors, every 0.1 mV increase in final litude was independently associated with survival to hospital discharge (aOR, 1.26 95% CI, 1.14–1.39 P 0.001) and initial cardioversion success (aOR, 1.19 95% CI, 1.07–1.32 P = 0.001). The duration of resuscitation also increased by 1.7 minutes (95% CI, 1.03–2.36 P 0.001) for every 0.1 mV increase in final litude. CONCLUSION: More than one-third of initial ventricular fibrillation OHCA cases were low in litude. Comparative international data are needed to better understand how low litude ventricular fibrillation rhythms confound the measurement of OHCA interventions and international benchmarks for survival outcomes.
Publisher: BMJ
Date: 12-01-2013
DOI: 10.1136/HEARTJNL-2012-303182
Abstract: We examined cognitive function in older hospitalised patients with chronic atrial fibrillation (AF). A prospective substudy of a multicentre randomised trial of an AF-specific disease management intervention (the Standard versus Atrial Fibrillation spEcific managemenT studY SAFETY). Three tertiary referral hospitals within Australia. A total of 260 patients with chronic AF: mean age 72±11 years, 53% men, mean CHA2DS2-VASc score 4±2. Cognitive function was assessed at baseline (during inpatient stay) using the Montreal Cognitive Assessment (MoCA). The extent of mild cognitive impairment (MCI-defined as a MoCA score <26) in AF patients and identification of independent predictors of MCI. Overall, 169 patients (65%, 95% CI 59% to 71%) were found to have MCI at baseline (mean MoCA score 21±3). Multiple deficits in cognitive domains were identified, most notably in executive functioning, visuospatial abilities and short-term memory. Predictors of MCI (age and sex-adjusted) were lower education level (technical/trade school level OR 6.00, 95% CI 2.07 to 17.42 <8 years school education OR 5.29, 95% CI 1.95 to 14.36 vs 8-13 years), higher CHA2DS2-VASc score (OR 1.46, 95% CI 1.23 to 1.74) and prescribed digoxin (OR 2.19, 95% CI 1.17 to 4.10). MCI is highly prevalent amongst typically older high-risk patients hospitalised with AF. Routine assessment of cognitive function with adjustment of clinical management is indicated for this patient group.
Publisher: MDPI AG
Date: 24-06-2021
DOI: 10.3390/AGRICULTURE11070584
Abstract: Among the waste by-products generated by the fruit industry (peels, seeds, and skins), fruit peel constitutes the major component. It is estimated that fruit peel accounts for at least 20% of the fresh fruit weight. Fruit peels are considered as major sources of dietary fiber and anticipated to be successfully utilized as prebiotics. This study examined the chemical composition, functional properties and the prebiotic effects of three major tropical fruit peels (apple, banana and mango). The prebiotic effect was tested using three commercial probiotic strains (Lactobacillus rhamnosus, L. casei and Bifidobacterium lactis) in idually and in combination. Each probiotic culture was fortified with different concentration (0%, 2% and 4%) of selected fruit peel powder (FPP). Results revealed that all tested FPP significantly (p 0.05) enhanced the probiotics viable counts, which reached logs after 24 h of incubation. However, the concentration of 2% and 4% FPP showed no significant differences (p 0.05) on the probiotic viable counts. Additionally, the prebiotic effects of FPP were the same when applied to in idual and mixed cultures. This investigation demonstrated that small amount (2%) of apple, banana and mango peel powder could be successfully utilized as prebiotics to enhance the growth of lactic acid bacteria (LAB). Additionally, the studied physical and chemical characteristics of FPP demonstrated their potential applications in the food and pharmaceutical industries as functional ingredients.
Publisher: Springer Science and Business Media LLC
Date: 12-2020
DOI: 10.1140/EPJC/S10052-020-08554-Y
Abstract: This paper reports on a search for heavy resonances decaying into WW , ZZ or WZ using proton–proton collision data at a centre-of-mass energy of $$\\sqrt{s}=13$$ s = 13 TeV. The data, corresponding to an integrated luminosity of 139 $$\\mathrm{fb}^{1}$$ fb 1 , were recorded with the ATLAS detector from 2015 to 2018 at the Large Hadron Collider. The search is performed for final states in which one W or Z boson decays leptonically, and the other W boson or Z boson decays hadronically. The data are found to be described well by expected backgrounds. Upper bounds on the production cross sections of heavy scalar, vector or tensor resonances are derived in the mass range 300–5000 GeV within the context of Standard Model extensions with warped extra dimensions or including a heavy vector triplet. Production through gluon–gluon fusion, Drell–Yan or vector-boson fusion are considered, depending on the assumed model.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 05-2021
Publisher: BMJ
Date: 02-2018
Publisher: Public Library of Science (PLoS)
Date: 29-05-2013
Publisher: BMJ
Date: 09-11-2010
Abstract: Little is known about the incidence and clinical characteristics of newly diagnosed atrial fibrillation/flutter (AF) in urban Africans in epidemiological transition. This observational cohort study was carried out in the Chris Hani Baragwanath Hospital in Soweto South Africa. A clinical registry captured detailed clinical data on all de novo cases of AF presenting to the Cardiology Unit during the period 2006-2008. Overall, 246 of 5328 cardiac cases (4.6%) presented with AF (estimated 5.6 cases/100 000 population/annum). Mean age was 59±18 years and the majority were of African descent (n=211, 86%) and/or female (n=150, 61%). Men were more than twice as likely to smoke (OR 2.88, 95% CI 1.92 to 4.04) than women, but women were twice as likely to be obese (OR 1.80, 95% CI 1.28 to 2.52) than men. Lone AF occurred in 22 (8.9%) cases, while concurrent valve disease and/or functional valvular abnormality occurred in 107 cases (44%). Overall, 171 cases (70%) presented with uncontrolled AF (ventricular rate >90 beats/min) with no sex-based differences. Common co-morbidities were any form of heart failure (56%) and rheumatic heart disease (21%). Women with AF were more likely to present with hypertensive heart failure (OR 2.37, 95% CI 1.24 to 4.54) but less likely to present with a dilated cardiomyopathy (OR 0.42, 95% CI 0.23 to 0.76) or coronary artery disease (OR 0.38, 95% CI 0.14 to 1.02) than men. Mean overall CHADS(2) score (in 195 non-rheumatic cases) was 1.51±0.91 and, despite a similar age profile, women had higher scores than men (1.73±0.94 vs 1.24±0.78 p<0.0001). These unique data suggest that urban Africans in Soweto develop AF at a relatively young age. Conventional strategies used to manage and treat AF need to be carefully evaluated in this setting.
Publisher: IOP Publishing
Date: 10-11-2020
Publisher: MDPI AG
Date: 05-04-2021
DOI: 10.3390/JCM10071514
Abstract: The aim of this study was to explore sex-specific associations between systolic blood pressure (SBP), hypertension, and the risk of incident atrial fibrillation (AF) subtypes, including paroxysmal, persistent, and permanent AF, in a general population. A total of 13,137 women and 11,667 men who participated in the fourth survey of the Tromsø Study (1994–1995) were followed up for incident AF until the end of 2016. Cox proportional hazards regression analysis was conducted using fractional polynomials for SBP to provide sex- and AF-subtype-specific hazard ratios (HRs) for SBP. An SBP of 120 mmHg was used as the reference. Models were adjusted for other cardiovascular risk factors. Over a mean follow-up of 17.6 ± 6.6 years, incident AF occurred in 914 (7.0%) women (501 with paroxysmal ersistent AF and 413 with permanent AF) and 1104 (9.5%) men (606 with paroxysmal ersistent AF and 498 with permanent AF). In women, an SBP of 180 mmHg was associated with an HR of 2.10 (95% confidence interval [CI] 1.60–2.76) for paroxysmal ersistent AF and an HR of 1.80 (95% CI 1.33–2.44) for permanent AF. In men, an SBP of 180 mmHg was associated with an HR of 1.90 (95% CI 1.46–2.46) for paroxysmal ersistent AF, while there was no association with the risk of permanent AF. In conclusion, increasing SBP was associated with an increased risk of both paroxysmal ersistent AF and permanent AF in women, but only paroxysmal ersistent AF in men. Our findings highlight the importance of sex-specific risk stratification and optimizing blood pressure management for the prevention of AF subtypes in clinical practice.
Location: Australia
Start Date: 2016
End Date: 2020
Funder: National Heart Foundation of Australia
View Funded ActivityStart Date: 2016
End Date: 2020
Funder: National Health and Medical Research Council
View Funded Activity