26 research outputs found

    A case study on application of the theory of planned behaviour: predicting physical activity of adolescents in Hong Kong

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    Objective: The aim of this case study was to predict the physical activity intention and behaviour of secondary school students in Hong Kong by applying the Ajzen’s Theory of Planned Behaviour (TPB) and past physical activity behaviour. Methods: 486 students (250 male and 236 female), ranging in age from 11 to 18 years, were enrolled in this study. By means of self-administrated questionnaire, demographic data, past physical activity and variables of theory of planned behaviour, such as attitude, subjective norm and perceived behavioural control were measured. Results: About 75% of students did not meet the standard of the physical activity recommended by government. Male had significantly higher behavioural intention than female. The variables of theory of planned behaviour explained 53.1% of physical activity intention with significant factors of subjective norm and perceived behavioural control (PBC), increasing to 56.2% with the addition of past physical activity behaviour. When predicting physical activity behaviour, theory of planned behaviour accounted for 26.6% of the variance. The prediction was further improved by including past physical activity behaviour. Conclusions: Results of this study give evidence that the theory of planned behaviour is a useful framework for prediction of physical activity intention of adolescents in Hong Kong. Among the variables, perceived behavioural control and past behaviour played a significant role in modelling the physical activity intention and behaviour of secondary school students

    Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

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    We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10-11 to 5.0 × 10-21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10-6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation

    Harmonizing brain magnetic resonance imaging methods for vascular contributions to neurodegeneration

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    Introduction Many consequences of cerebrovascular disease are identifiable by magnetic resonance imaging (MRI), but variation in methods limits multicenter studies and pooling of data. The European Union Joint Program on Neurodegenerative Diseases (EU JPND) funded the HARmoNizing Brain Imaging MEthodS for VaScular Contributions to Neurodegeneration (HARNESS) initiative, with a focus on cerebral small vessel disease. Methods Surveys, teleconferences, and an in-person workshop were used to identify gaps in knowledge and to develop tools for harmonizing imaging and analysis. Results A framework for neuroimaging biomarker development was developed based on validating repeatability and reproducibility, biological principles, and feasibility of implementation. The status of current MRI biomarkers was reviewed. A website was created at www.harness-neuroimaging.org with acquisition protocols, a software database, rating scales and case report forms, and a deidentified MRI repository. Conclusions The HARNESS initiative provides resources to reduce variability in measurement in MRI studies of cerebral small vessel disease

    Knowledge discovery for adaptive negotiation agents in e-marketplaces

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    Intelligent software agents are promising in improving the effectiveness of e-marketplaces for e-commerce. Although a large amount of research has been conducted to develop negotiation protocols and mechanisms for e-marketplaces, existing negotiation mechanisms are weak in dealing with complex and dynamic negotiation spaces often found in e-commerce. This paper illustrates a novel knowledge discovery method and a probabilistic negotiation decision making mechanism to improve the performance of negotiation agents. Our preliminary experiments show that the probabilistic negotiation agents empowered by knowledge discovery mechanisms are more effective and efficient than the Pareto optimal negotiation agents in simulated e-marketplaces

    Strong antiferromagnetic proximity coupling in the heterostructure superconductor Sr2VO3-δFeAs

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    © 2022 American Physical Society.We report the observation of strong magnetic proximity coupling in the heterostructure superconductor Sr2VO3-δFeAs, determined by upper critical field Hc2(T) measurements up to 65 T. Using the resistivity and the radio-frequency measurements for both H∥ab and H∥c, we found a strong upward curvature of Hc2c(T), together with a steep increase in Hc2ab(T) near Tc, yielding an anisotropic factor γH=Hc2ab/Hc2c up to ∼20, much higher than those of other iron-based superconductors. These are attributed to the Jaccarino-Peter effect, rather than to the multiband effect, due to strong exchange interaction between itinerant Fe spins of the FeAs layers and localized V spins of Mott-insulating SrVO3-δ layers. These findings provide evidence for strong antiferromagnetic proximity coupling that is comparable to the intralayer superexchange interaction of the SrVO3-δ layer and sufficient to induce magnetic frustration in Sr2VO3-δFeAs.11Nsciescopu
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