2,055 research outputs found
Development and validation of computational fluid dynamics models for the coupled simulation of heat transfer and fluid flow in the coral microenvironments
This thesis explored the temperature deviations between coral surface temperature and ambient seawater temperature that likely determines the microscale processes involved in coral bleaching. The work presented here applied Computational Fluid Dynamics (CFD) technique coupled with hydrodynamic modelling and ray-tracing to predict coral surface warming due to the effects of stressors. This thesis demonstrates that modelling microscale temperature could yield important insights into thermoregulation in corals, which may lead to a more effective reef management
The language of suffering: Media discourse and public attitudes towards the MH17 air tragedy in Malaysia and the UK
āIf it bleeds, it leadsā, events characterised by fatalities, are likely to attract high levels of media coverage. This study adopts a multidisciplinary approach to investigate public discourses on the MH17 tragedy in Malaysia and the United Kingdom. First, corpus-based discourse analysis was employed to explore the construction of the Malaysian Airlines tragedy MH17 in four selected Malaysian and British newspapers. In addition, an attitudinal study examining 50 Malaysian and 50 UK nationalsā perceptions of the tragedy was conducted. Keywords analysis revealed an overall tendency for the news media to construct the air tragedy through classifications between āusā and āothersā. Specifically, important āUsā (Malaysian elites) and non-important āOtherā (non-Malaysian) in the Malaysian newspapers, versus good āUsā (the West) and evil āOthersā (Russia) in the British newspapers. The attitudinal analysis shows, for both the Malaysian and the UK respondents, the most salient associations with the MH17 tragedy related to āconflictsā
Learning the kernel with hyperkernels
This paper addresses the problem of choosing a kernel suitable for estimation with a support
vector machine, hence further automating machine learning. This goal is achieved by defining
a reproducing kernel Hilbert space on the space of kernels itself. Such a formulation leads to a
statistical estimation problem similar to the problem of minimizing a regularized risk functional.
We state the equivalent representer theorem for the choice of kernels and present a semidefinite
programming formulation of the resulting optimization problem. Several recipes for constructing
hyperkernels are provided, as well as the details of common machine learning problems. Experimental
results for classification, regression and novelty detection on UCI data show the feasibility
of our approach
Weak-field induced nonmagnetic state in a Co-based honeycomb
Layered honeycomb magnets are of interest as potential realizations of the
Kitaev quantum spin liquid (KQSL), a quantum state with long-range spin
entanglement and an exactly solvable Hamiltonian. Conventional magnetically
ordered states are present for all currently known candidate materials,
however, because non-Kitaev terms in the Hamiltonians obscure the Kitaev
physics. Current experimental studies of the KQSL are focused on 4d- or
5d-transition-metal-based honeycombs, in which strong spin-orbit coupling can
be expected, yielding Kitaev interaction that dominate in an applied magnetic
field. In contrast, for 3d-based layered honeycomb magnets, spin orbit coupling
is weak and thus Kitaev-physics should be substantially less accessible. Here
we report our studies on BaCo2(AsO4)2, for which we find that the magnetic
order associated with the non-Kitaev interactions can be fully suppressed by a
relatively low magnetic field, yielding a non-magnetic material and implying
the presence of strong magnetic frustration and weak non-Kitaev interactions
Pulmonary deposition of radionucleotide-labeled palivizumab : proof-of-concept study
Objective: Current prevention and/or treatment options for respiratory syncytial virus (RSV) infections are limited as no vaccine is available. Prophylaxis with palivizumab is very expensive and requires multiple intramuscular injections over the RSV season. Here we present proof-of-concept data using nebulized palivizumab delivery as a promising new approach for the prevention or treatment of severe RSV infections, documenting both aerosol characteristics and pulmonary deposition patterns in the lungs of lambs. Design: Prospective animal study. Setting: Biosecurity Control Level 2-designated large animal research facility at the Murdoch Childrenās Research Institute, Melbourne, Australia. Subjects: Four weaned Border-Leicester/Suffolk lambs at 5 months of age. Interventions: Four lambs were administered aerosolized palivizumab conjugated to Tc-99m, under gaseous anesthesia, using either the commercially available AeroNeb GoĀ® or the investigational HYDRA device, placed in-line with the inspiratory limb of a breathing circuit. Lambs were scanned in a single-photon emission computed tomography (SPECT/CT) scanner in the supine position during the administration procedure. Measurements and Main Results: Both the HYDRA and AeroNeb GoĀ® produced palivizumab aerosols in the 1ā5 Āµm range with similar median (geometric standard deviation and range) aerosol droplet diameters for the HYDRA device (1.84 Ā± 1.40 Ī¼m, range = 0.54ā5.41Ī¼m) and the AeroNeb GoĀ® (3.07 Ā± 1.56 Ī¼m, range = 0.86ā10 Ī¼m). Aerosolized palivizumab was delivered to the lungs at 88.79ā94.13% of the total aerosolized amount for all lambs, with a small proportion localized to either the trachea or stomach. No difference between devices were found. Pulmonary deposition ranged from 6.57 to 9.25% of the total dose of palivizumab loaded in the devices, mostly in the central right lung. Conclusions: Aerosolized palivizumab deposition patterns were similar in all lambs, suggesting a promising approach in the control of severe RSV lung infections. Ā© Copyright Ā© 2020 Rajapaksa, Do, Suryawijaya Ong, Sourial, Veysey, Beare, Hughes, Yang, Bischof, McDonnell, Eu, Yeo, Licciardi and Mulholland. ***Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate āRobert Bishofā is provided in this record***Ā The authors thank Rebecca Sutton for her technical assistance on lamb management, and Kera Pethybridge and Ellie Wright for her technical assistance on nuclear imaging. This study is?supported by a Jack Brockhoff Foundation Early Career Research Grant and a National Health and Medical Research Council (NHMRC) Early Career Fellowship (GNT1123030) awarded to AR, and the Victorian Government?s Operational Infrastructure Support Program. PL is supported by an NHMRC Career Development Fellowship (GNT1165084)
Psychological correlates of quality of life in atrial fibrillation
Objective:
Atrial fibrillation (AF) is associated with significant health-related quality of life (QoL) impairments. Markers of heart disease severity have explained little variance in QoL and it is unclear what other factors will better account for the observed differences in adjustment. We examined whether specific personality traits and illness management styles would help explain the severity of QoL impairments reported in this population.
Methods:
Patients with AF (N = 93) completed validated questionnaires measuring disease burden (dependent variables: physical and mental QoL, symptom severity, psychological distress), personality (independent variables: anxiety sensitivity, optimism), and illness management style (mediating variable: symptom preoccupation). Hypothesized relationships were evaluated using mediation models.
Results:
Anxiety sensitivity was associated with poorer physical and mental QoL, greater symptom severity, and higher distress. Optimism was correlated with better mental QoL and lower distress, but unrelated to physical QoL and symptom severity. Symptom preoccupation significantly mediated the relationships between anxiety sensitivity and each of the QoL measures, as well as the relationships between optimism and mental well-being.
Conclusions:
Personality traits and illness management styles are important to consider when assessing the impact of AF on QoL. The data support a cognitive-behavioral model that explains the direct and indirect relationships between psychological predictors and multiple indices of QoL.Social Sciences and Humanities Research Counci
Gender differences and quality of life in atrial fibrillation: The mediating role of depression
Objective
This study investigated gender differences, depression, and health-related quality of life (QoL) in a cross-sectional sample of patients with atrial fibrillation (AF).
Methods
This cross-sectional study involved a convenience sample of AF patients from two tertiary-care clinics in Toronto, Canada. Ninety-three AF patients completed psychometrically validated measures of generic QoL and depression. Mediation analyses evaluated the relationship between gender and QoL using depression as mediating variable.
Results
Relative to male patients, female patients reported lower physical, but not mental, QoL. Gender was associated with both depression and physical QoL, while depression was correlated with poorer physical QoL. Path analyses demonstrated that depression significantly mediated the relationship between gender and physical QoL.
Conclusion
Among AF patients, female patients report lower physical QoL relative to male patients, and this relationship may be mediated by self-reported symptoms of depression. Albeit correlational, the findings underscore the need to develop a better understanding of the role of depression in physical QoL, especially when considering the burden of AF in women.Social Sciences and Humanities Research Counci
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