A Parallel Branch and Bound Algorithm for the Maximum Labelled Clique Problem

The maximum labelled clique problem is a variant of the maximum clique problem where edges in the graph are given labels, and we are not allowed to use more than a certain number of distinct labels in a solution. We introduce a new branch-and-bound algorithm for the problem, and explain how it may be parallelised. We evaluate an implementation on a set of benchmark instances, and show that it is consistently faster than previously published results, sometimes by four or five orders of magnitude.Comment: Author-final version. Accepted to Optimization Letter

Amelioration of soils contaminated with radionuclides:Exploiting biodiversity to minimise or maximise soilto plant transfer

Objective: Computed Tomography (CT) is the leading contributor to medical exposure to ionizing radiation. Although the use of CT brain scans for patients with head injuries and convulsions has shown a tremendous growth, it has raised substantial concerns in the general public because of the risk of radiation-induced cataracts: the current available strategies to reduce the radiation dose to the eye lens region are limited. Therefore, the present research project was initiated with the aim of evaluating the potential benefit of the combined use of bolus and a bismuth shield on reducing the radiation dose to the eye lens region during CT brain examination.Materials and methods: We conducted a series of phantom studies to measure the entrance surface dose (ESD) that is delivered to the eye lens region during CT brain examination under the effect of different scanning and shielding setups.Results: Our results indicated, during CT brain examination: (1) a drastic reduction of 92.5% in the ESD to the eye lens region was found when the CT gantry was tilted from 0 degrees (overall ESD = 30.7 mGy) to 30 degrees cranially (overall ESD = 2.4 mGy), and (2) when the CT gantry was positioned at 0 degrees (the common practice in the clinical setting), the setups with the application of a) a bismuth shield, b) a bismuth shield with a face shield (air gap), c) a bismuth shield with bolus, and d) a bismuth shield with bolus and an air gap can result in an acceptable level of image quality with a smaller overall ESD delivered to the eye lens region (overall ESD = 23.2 mGy, 24 mGy, 21 mGy and 19.9 mGy, respectively) than the setup without the bismuth shield applied (overall ESD = 30.7 mGy).Conclusion: When the primary beam scanning through the eye lens region is unavoidable during CT brain examination, the combined use of a bismuth shield with bolus and a face shield is an easy-to-use and inexpensive shielding setup to reduce the radiation dose delivered to the eye lens region while maintaining the correct CT number and a low degree of image noise in the resultant image.Department of Health Technology and Informatic

Development and evaluation of a training workshop for lay health promoters to implement a community-based intervention program in a public low rent housing estate: The Learning Families Project in Hong Kong

published_or_final_versio

Cross-sectional difference in BMI between senior and junior students predicts prospective change in BMI at the school level

Poster Presentation: abstract no. 1196The Conference abstracts's website is located at http://www2.kenes.com/apccn/scientific/Pages/ListofAbstracts.aspxOBJECTIVES: To examine whether cross-sectional BMI difference between senior and junior secondary school students was correlated with prospective changes in BMI at the school level. BACKGROUND: Schools are known to exert prospective influences on adolescent BMI. The school effects may also be reflected in cross-sectional BMI differences between senior and junior students in each school. Schools could quickly be identified for weight-control interventions if such cross-sectional differences could predict prospective changes in BMI. METHODS: In the Hong Kong Student …postprin

Alcohol consumption and sleep problems in Hong Kong adolescents

postprin

Translating tobacco related research into public health actions

Abstract and powerpoint presentation under Country Experience on Smoking CessationpostprintThe International Symposium on Management of Tobacco Dependence: From East to West, North to South, Hong Kong, 12-13 February 2009

Risk factors and outcomes of childhood obesity in Hong Kong: a retrospective cohort study

published_or_final_versio

Awareness and perceived harmfulness of e-cigarettes and their associations with smokers: intention to quit in Hong Kong

Poster Discussion 28. E-cigarettes: Evidence and Analysis: no. PD-925-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: There is an ongoing debate on using Electronic cigarettes (E-cig) as an alternative to reduce harms or assist in smoking cessation. Currently, the use of E-cig in Hong Kong adults is extremely low because sale of nicotine-loaded E-cig is restricted by law. We investigated the prevalence of awareness, perceived harmfulness of E-cig and their associations with smokers’ intention to quit. DESIGN/METHODS: A population-based computer-assisted telephone survey was conducted in 2013 in 2401 randomly selected Chinese respondents aged 15 to 65. Information …published_or_final_versio

Electrophysiological Mechanisms of Gastrointestinal Arrhythmogenesis: Lessons from the Heart.

This is the final published version. It first appeared at http://journal.frontiersin.org/article/10.3389/fphys.2016.00230/full.Disruptions in the orderly activation and recovery of electrical excitation traveling through the heart and the gastrointestinal (GI) tract can lead to arrhythmogenesis. For example, cardiac arrhythmias predispose to thromboembolic events resulting in cerebrovascular accidents and myocardial infarction, and to sudden cardiac death. By contrast, arrhythmias in the GI tract are usually not life-threatening and much less well characterized. However, they have been implicated in the pathogenesis of a number of GI motility disorders, including gastroparesis, dyspepsia, irritable bowel syndrome, mesenteric ischaemia, Hirschsprung disease, slow transit constipation, all of which are associated with significant morbidity. Both cardiac and gastrointestinal arrhythmias can broadly be divided into non-reentrant and reentrant activity. The aim of this paper is to compare and contrast the mechanisms underlying arrhythmogenesis in both systems to provide insight into the pathogenesis of GI motility disorders and potential molecular targets for future therapy