Bi-level decisions of vacant taxi drivers traveling towards taxi stands in customer-search: Modeling methodology and policy implications

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A patient with non-Q wave acute inferior myocardial infarction

The occurrences of atrioventricular (AV) nodal blockade or right ventricular (RV) infarction in acute inferior myocardial infarction (MI) had been well recognised and signified a proximal right coronary artery (RCA) occlusion. However, they did not point out the extent of the RCA territory involved. We recently managed a patient with incomplete inferior MI in which ECG on presentation already showed (he infarct-related RCA as the dominant vessel having proximal occlusion. Various aggressive treatments have been taken subsequently.published_or_final_versio

Routing algorithm for provisioning symmetric virtual private networks in the hose model

A virtual private network (VPN) is a private data network where remote sites are connected over a shared provider network. In order to provide secure communications between customer sites, predetermined paths are used to forward data packets. To support quality of service (QoS), bandwidth has to be reserved on these paths. Then, finding appropriate paths in order to optimize the bandwidth used becomes an important problem. In this paper, we study the routing problem of VPNs under the hose model, where VPN endpoints specify the maximum bandwidth they need in sending and receiving data. Some previous works considered the problem under the assumption that all links have infinite capacities. We remove this constraint in our studies and develop enhancement to existing algorithms. Our simulation results show that our algorithm works very well in networks where link capacities are tight. © 2005 IEEE.published_or_final_versio

A postgraduate diploma course in community geriatrics for primary care doctors: Experience of first three years

This paper describes the setting up of a postgraduate diploma course in Community Geriatrics for primary care physicians and the experience gained in its first three years of running. This study programme was set up in response to the rapidly rising elderly population in Hong Kong and the fact that most of the primary care doctors practising today had an inadequate undergraduate curriculum in the health care issues that are relevant to older people. The objectives of the Course are to improve the knowledge, skills and confidence of primary care physicians in the care of elderly people. It also emphasises the aspects of care that are unique to elderly people. The Course is delivered by different modes of learning: distance learning, face-to-face problem-orientated seminars and small group clinical teaching. Learning centres are established in different regional hospitals in Hong Kong in order to allow small group clinical teaching while, at the same time, reducing travelling time for the students. Information technology is also used to facilitate teaching and learning, as well as to encourage communication among teachers and students. The Course was oversubscribed for all its intakes in the first three years of running. Some graduates have taken on visiting medical officer positions at elderly homes.published_or_final_versio

Effects of smoking on healing response to non-surgical periodontal therapy: A multilevel modelling analysis

Wan CP, Leung WK, Wong MCM, Wong RMS, Wan P, Lo ECM, Corbet EF. Effects of smoking on healing response to non-surgical periodontal therapy: a multilevel modelling analysis. J Clin Periodontol 2009; 36: 229-239. doi: 10.1111/j.1600-051X.2008.01371.x. Abstract Aim: To investigate the factors predicting non-surgical periodontal treatment responses using multilevel multiple regression. Material and Methods: Forty men (mean 45.6 years) were recruited; 20 were smokers. A 12-month reduction in probing pocket depth (PPD) and gain in probing attachment level (PAL) of 5814 sites were analysed, with 594 being initially diseased sites (initial PPD≥5 mm). Results: Variance Component models showed that site-level variations contributed about 70-90% of the total variance. About a 10% reduction of the total variations of PPD reduction in initially diseased sites was achieved with the inclusion of the 10 predictors in the multilevel multiple regression. Multilevel multiple regression showed that three predictors, subject level: non-smokers; tooth-level: anterior teeth; and site level: sites without plaque at baseline, were significantly associated with a greater reduction in PPD in initially diseased sites over the 12-month study period (p<0.05). No consistent predictor was found for PAL gain. Conclusion: Multilevel analysis was applied on periodontal treatment response data. Smokers showed less favourable PPD reduction at deep sites after non-surgical periodontal therapy. © 2009 John Wiley & Sons A/S.postprin

Status of six non-native marine species in the coastal environment of Hong Kong, 30 years after their first record

This is the first systematic assessment conducted on fouling communities to determine the current status of six non-native marine invertebrates that were first recorded in Hong Kong three decades ago. They include the solitary ascidian, Ciona intestinalis; the slipper limpet, Crepidula onyx; the bryozoan, Bugula californica; the Caribbean bivalve, Mytilopsis sallei; the Mediterranean mussel, Mytilus galloprovincialis; and the boring isopod, Sphaeroma walkeri. Field surveys were conducted at 31 locations during wet (2011) and dry (2012) seasons and included fouling communities on piers and mariculture zones from estuarine to oceanic zones. The sampling was conducted by using photo-quadrats, destructive quadrats and field observations. To detect temporal changes in the abundance and recruitment of the sedentary non-native species, three piers were monitored with permanent photo-quadrats and recruitment panels for a one year period. We examined the relationship between seawater quality data available for Hong Kong and the abundances of fouling and non-native species. Only four of the six target non-native species were recorded in this survey. The isopod Sphaeroma walkeri was common and widely distributed in fouling communities in Hong Kong, while Ciona intestinalis, Crepidula onyx, and Mytilopsis sallei were uncommon and mainly restricted to areas with intensive human activities and poor seawater quality. These findings suggest that near shore human activities and poor water quality could increase the risk of establishment of non-native species in Hong Kong’s marine fouling communities.published_or_final_versio

Urotensin II in hypertension

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Resumption of sexual activity in patients with myocardial infarction after cardiac rehabilitation

The Medical Research Conference'99, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, 30-31 January 1999published_or_final_versio

Myocardial fiber length mapping with MR diffusion tensor imaging

Diffusion tensor MRI is emerging as a rapid, nondestructive method to map myocardial fiber organization. A precise biological description of myocardial fiber performance requires knowledge of four variables: length, force, velocity and time. However, study of quantification of myocardial fiber length is lacking. The current study aims to show myocardial fiber length maps of formalin-fixed heats. Diffusion tensor MRI with medium diffusion resolution (15 directions) was performed in one isolated pig heart. Fiber length maps were investigated in multiple short-axis slices. The results provide supplementary information of myocardial fiber organization. To our knowledge, the present study is the first report of the myocardial fiber length mapping. © 2005 IEEE.published_or_final_versio