Tilings of the Sphere by Edge Congruent Pentagons

We study edge-to-edge tilings of the sphere by edge congruent pentagons, under the assumption that there are tiles with all vertices having degree 3. We develop the technique of neighborhood tilings and apply the technique to completely classify edge congruent earth map tilings.Comment: 36 pages, 34 figure

Argument omission in Cantonese preschool children: a discourse-pragmatics perspective

Thesis (B.Sc)--University of Hong Kong, 2006."A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2006."Also available in print.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Diagnosis of 3D magnetic field and modes composition in MHD turbulence with Y-parameter

Magnetic fields are crucial in numerous astrophysical processes within the interstellar medium. However, the detailed determination of magnetic field geometry is notoriously challenging. Based on the modern magnetohydrodynamic (MHD) turbulence theory, we introduce a novel statistical technique, the "Y-parameter", to decipher the magnetic field inclination in the ISM and identify dominant turbulence modes. The Y-parameter, calculated as the ratio of anisotropies of different Stokes parameter combinations, displays contrasting trends with the mean-field inclination angle in Alfv\'enic and compressible turbulence modes. A Y-parameter value around $1.5\pm0.5$ provide a statistical boundary to determine the dominant MHD turbulence modes. We have discovered specific correlations between the Y-parameter value and the inclination angle that unveil the dominant turbulence mode. This methodology, when applied to future radio polarisation surveys such as LOFAR and SKA, promises to significantly enhance our knowledge of 3D magnetic field in the ISM and improve our understanding of interstellar turbulence.Comment: 13 pages, 10 figures, 1 table, Accepted for publication in MNRA

Temporal Properties of the Compressible Magnetohydrodynamic Turbulence

The temporal property of the compressible magneto-hydrodynamic (MHD) turbulence remains a fundamental unsolved question. Recent studies based on the spatial-temporal analysis in the global frame of reference suggest that the majority of fluctuation power in turbulence does not follow any of the MHD wave dispersion relations but has very low temporal frequency with finite wavenumbers. Here, we demonstrate that the Lorentzian broadening of the dispersion relations of the three MHD modes where the nonlinear effects act like the damping of a harmonic oscillator can explain many salient features of frequency spectra for all MHD modes. The low frequency fluctuations are dominated by modes with the low parallel wavenumbers that have been broadened by the nonlinear processes. The Lorentzian broadening widths of the three MHD modes exhibit scaling relations to the global frame wavenumbers and are intrinsically related to energy cascade of each mode. Our results provide a new window to investigate the temporal properties of turbulence which offers insights for building a comprehensive understanding of the compressible MHD turbulence.Comment: 15 pages, 4 figures, submitte

Psychometric properties of the Chinese version of the fatigue scale-adolescent

© 2015 Ho et al. Background: The availability of a valid and reliable instrument that accurately assesses the level of fatigue among adolescent cancer survivors is crucial before any appropriate interventions to reduce their fatigue can be appropriately planned and evaluated. The study aimed to test the psychometric properties of the Chinese version of the Fatigue Scale for Adolescents. In particular, confirmatory factor analysis was conducted to examine its factorial structure. Methods: A cross-sectional study was employed. Adolescents (13- to 18-year-olds) who had survived cancer and attended medical follow-up at the outpatient clinic in Hong Kong were invited to participate. The internal consistency, content validity and construct validity and test-retest reliability of the Chinese version of the Fatigue Scale for Adolescents were assessed. Results: The content validity index was 0.92. There was a strong positive correlation between adolescents' levels of fatigue and depressive symptoms (r=0.53) and a strong negative correlation between adolescents' levels of fatigue and quality of life (r=-0.58). The mean levels of fatigue of the survivors group was significantly lower than that of those still receiving treatment in hospital, but significantly higher than that of their healthy counterparts. Confirmatory factor analysis indicated that there were 4 factors underlying the Chinese version of the Cancer Module. Conclusions: The findings of the study add further evidence that the Chinese version of the Fatigue Scale for Adolescents (12-item) can be used as a reliable and valid tool in assessing cancer-related fatigue among Hong Kong Chinese adolescents who have survived cancer.published_or_final_versio

Perceptions, behaviours and attitudes towards smoking held by the male partners of Chinese pregnant women:a qualitative study

Abstract Background Direct associations of tobacco exposure during pregnancy with pregnancy complications and adverse birth outcomes have been proven. Previous studies suggest that expecting a child provides a valuable opportunity to promote behavioural changes, such as smoking cessation, among the male partners of pregnant women. Thorough understandings of Chinese expectant fathers’ smoking behaviour during the transition to fatherhood is a prerequisite to the development of appropriate interventions to facilitate smoking cessation. This study aimed to explore the perceptions, behaviours and attitudes related to smoking among male partners of pregnant women in China. Methods A descriptive phenomenological approach was adopted. A purposive sample of expectant fathers aged 18 years or older who had a tobacco use history within the past year were recruited at obstetrics and gynaecology clinics and invited to participate in one-to-one, 20–30-min semi-structured interviews. The data analysis followed Colaizzi’s descriptive phenomenological method. Results Twenty-five expectant fathers were interviewed. Four themes were generated: 1) the benefits of smoking and respondents’ misperceptions of the impact of smoking and SHS and neglectful attitude of the impact of smoking, which were given as the major reasons for continuing to smoke; 2) factors contributing to smoking cessation, including concern for the potential health impact of continued smoking on the pregnant partner and baby, the role of being father, and the encouragement to quit from family members; and 3) perceived barriers to smoking cessation, including withdrawal symptoms or cigarette cravings, absence of smoking cessation support, and increasing stress. Conclusion This study provides a comprehensive understanding of the perception, behaviours, and attitudes related to smoking among Chinese expectant fathers. The findings of this study can guide healthcare professionals and policymakers in combining the distribution of educational information about the hazards of SHS for maternal and neonatal health with smoking cessation assistance for expectant fathers through policy initiatives and other types of incentives and programmes targeted to enhance smoking cessation among this population. Trial registration Prospectively registered at clinicaltrial.org ( NCT03401021 ) on 8 Jan 2018

Associations between child maltreatment and adolescents’ health-related quality of life and emotional and social problems in low-income families, and the moderating role of social support

This study aimed to examine the associations between different types of child maltreatment and health-related quality of life (HRQoL) and emotional and social problems in adolescents, and to examine the moderating effect of social support on those associations. A cross-sectional survey was conducted between January and June 2016 in Hong Kong. The sample comprised 351 parent and adolescent dyads from low-income families. The parents reported on child maltreatment (physical abuse, psychological aggression, and neglect), and the adolescents reported on their HRQoL, emotional problems, and social problems. The adolescents’ perceived social support was included as a potential moderator. Results of the study show that child physical abuse was strongly associated with emotional and social problems (B = 0.91-1.45, p < .05). Lower overall HRQoL was associated with psychological aggression (B = −3.96, p < .05) and neglect (B = −4.14, p < .05). Physical functioning was affected by psychological aggression (B = −3.16, p < .05), and emotional functioning was affected by neglect (B = −4.82, p < .05). Social functioning was impacted by all three types of maltreatment (B = −9.16 to −5.26, p < .05). This study extends previous literature by showing the varying effects of different types of child maltreatment on children’s health in the context of low-income families. The findings of this study also support that peer social support may buffer the effects of child physical abuse on adolescents’ emotional and social problems