On a region-of-interest based approach to robust wireless video transmission

This paper presents a scheme aiming at transmitting real-time video to wireless channel with vigorously varying quality, which is in practice the norm rather than the exception. Region of Interest (ROI) is an efficient approach to making the video more adaptive to the wireless channel because ROI is the region that human eyes tend to put more attention to than the Remainder Region (RM). In our proposed scheme, we will adopt this feature. The real-time source video stream is divided into two regions, the ROI and the RM regions. The two regions will be encoded using H.263 standard codec such that the video transmission is adaptive to the current channel state, which is characterized by the effective data rate that varies from tens of kilobits per second to hundreds of kilobits per second. Channel state parameters are fed back to the source coder to adjust the compression ratio as well as the intra/inter options of the encoders. Results including frame loss probability, compression characteristics, Peak Signal the Noise Ratio (PSNR) against channel states are given, indicating that the resulting adaptive video codec can respond judiciously to time-varying channel quality. Our scheme is evaluated together with a ROI-enabled moving picture coding standard JPEG2000. Using the features provided in JPEG2000, we have made the JPEG2000 codec adaptive to the vigorously varying wireless channel and then compared it with the H.263 scheme. Our technique is suitable for a broad area of applications including real-time news reporting and video conferencing.published_or_final_versio

Comparison of green roof performance in stormwater mitigation

Paper no. 81365The impervious surfaces in urban areas often increase overland flow and river discharge leading to flooding issues. Green roof, being one low impact development technique, can potentially facilitate stormwater management and advert flooding problems. Although there are a number of studies examining the hydrologic behaviour of green roof, they are often limited to the monitoring periods which may not involve extreme rainfall events. They are also specific to the rainfall conditions of the study areas, making it difficult to transfer the knowledge to other countries. This study uses numerical models to quantify the hydrological behaviour of green roof and to examine the effectiveness of green roof in stormwater management. In particularly, it compares its performance in extreme rainfall events of different countries. A one-dimensional variably-saturated flow model is used. The calibrated model is subjected to the rainfall conditions of a few cities (i.e., Hong Kong, Singapore, Nagoya and London) of two-year return period. The reduction and the delay of the peak discharge, and the fraction of water retained are compared. The green roof performances (e.g., peak reduction, rainfall retained) vary due to the differences in rainfall characteristics (e.g., temporal pattern, total rainfall volume). The modeling results from different countries allow a consistent comparison, generating insights that might facilitate the transfer of results across countries. Overall, this study improves our understanding of hydrological behaviour of green roofs for stormwater management, in particularly benefiting the interpretation of green roof hydrological studies performed at rainfall conditions different from the area of interests.published_or_final_versio

Unilateral epistaxis after swimming in a stream

A 55-year-old Chinese woman presented with a 3-week history of unilateral left-sided epistaxis and nasal obstruction. She had swum in a freshwater stream 1 month prior to the onset of symptoms. Endoscopic examination revealed a live leech at the left middle meatus with a large part of its body inside the left maxillary antrum. Local anaesthetic was applied to anaesthetise the leech and facilitate removal. Magnetic resonance imaging performed following removal confirmed that no other leeches were present in the sinonasal area. The endoparasitism might have persisted because of the inconspicuous site of infestation and the absence of pain. This form of leech infestation has not been previously reported.published_or_final_versio

香港977位慢性鼻炎患者的過敏原皮膚點刺測試結果

OBJECTIVES: To evaluate the prevalence of aetiological allergens identifiable by skin prick test alone in patients suffering from chronic rhinitis in Hong Kong, and also compare the clinical history and symptoms of skin prick test-positive versus skin prick test-negative patients. DESIGN: Prospective study. SETTING: Otorhinolaryngology clinic in Queen Mary Hospital of Hong Kong. PATIENTS: A total of 977 patients suffering from chronic rhinitis were recruited into the study. Skin prick test was performed with a panel of allergens including house dust mites, cockroach, cat, dog, moulds, and pollens. MAIN OUTCOME MEASURES: Skin prick test results and their correlation with symptoms. RESULTS: Of the 977 patients, 651 (67%) had positive skin prick test reactions. The commonest allergen was house dust mite which was positive in 63% of the 977 patients and 95% of those 651 skin prick test-positive patients. The other allergens were in order of cockroach (23%), cat (14%), dog (5%), pollen (4%), and mould (3%). Compared with skin prick test-negative patients, skin prick test-positive patients were more likely to have earlier age of onset of the chronic rhinitis, association with asthma, more severe symptom in the morning, more severe symptoms of itchy nose, sneezing, nasal discharge, itchy eye, and watery eye. CONCLUSIONS: Identifiable aeroallergens could be detected in 67% chronic rhinitis patients by skin prick test alone. House dust mites were the most prevalent causative allergen. There were significant differences of patterns of clinical history and symptoms severity between skin prick test-positive and skin prick test-negative patients.published_or_final_versio

Early single-centre comparative results on non-thermal ablation of symptomatic incompetent great saphenous veins (GSV): cyanoacrylate glue (VenaSeal) versus mechanicochemical ablation (ClariVein)

Speakers' corner: Selected original research abstracts - supraaortic and venouspublished_or_final_versio

Soft eSkin:distributed touch sensing with harmonized energy and computing

Inspired by biology, significant advances have been made in the field of electronic skin (eSkin) or tactile skin. Many of these advances have come through mimicking the morphology of human skin and by distributing few touch sensors in an area. However, the complexity of human skin goes beyond mimicking few morphological features or using few sensors. For example, embedded computing (e.g. processing of tactile data at the point of contact) is centric to the human skin as some neuroscience studies show. Likewise, distributed cell or molecular energy is a key feature of human skin. The eSkin with such features, along with distributed and embedded sensors/electronics on soft substrates, is an interesting topic to explore. These features also make eSkin significantly different from conventional computing. For example, unlike conventional centralized computing enabled by miniaturized chips, the eSkin could be seen as a flexible and wearable large area computer with distributed sensors and harmonized energy. This paper discusses these advanced features in eSkin, particularly the distributed sensing harmoniously integrated with energy harvesters, storage devices and distributed computing to read and locally process the tactile sensory data. Rapid advances in neuromorphic hardware, flexible energy generation, energy-conscious electronics, flexible and printed electronics are also discussed. This article is part of the theme issue ‘Harmonizing energy-autonomous computing and intelligence’

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

A New Definition of Intelligent Buildings for Asia

Intelligent building (IB) is the future of our building industry. All new commercial buildings and probably luxurious domestic buildings are designed with a common goal – to become intelligent buildings. However, the official definition of IB has not yet been standardised around the world. In the USA, an IB is categorised by four basic elements, namely building structure, building systems, building services and building management. In Europe, the emphasis is on information technology and the genuine need of the user. In Singapore and China, it appears that the term “automation” has been dominating with a great emphasis on high technology. It is our view that a proper definition of IB should be based on users’ needs instead of the image of the building itself. We have therefore developed a new method for defining and specifying IBs. The requirements of users are categorised into eight key modules. All building systems and features are summarised in terms of tens of elements. Selected elements are assigned to a particular key area, i.e. module. Each type of building is then allocated certain key areas for detailed design. Once the areas have been chosen, the elements will automatically be assigned for the consultants to carry out detailed design works. This concept of definition has both advantages of comprehensiveness and flexibility, hoping that it will be useful for the developments of IBs not merely in Asia but also the whole world

Leaking thoraco-abdominal aortic aneurysm in Marfan syndrome

Marfan syndrome is a congenital disorder of the connective tissue involving the ocular, skeletal and cardiovascular systems. Cardiovascular complications account mainly for the reduced life expectancy of patients with Marfan syndrome. Thoracic aortic aneurysms usually occur as a result of proximal aortic dissection but aneurysms of the descending aorta are infrequent. We report on a patient with rupture of an extensive thoraco-abdominal aortic aneurysm (Crawford type III) with a concomitant chronic thoracic aortic dissection (Stanford type A), treated successfully with aneurysmectomy and visceral artery reconstruction. Subsequent surgical intervention for the concomitant chronic thoracic aortic dissection was also performed. The importance of life-long surveillance of the cardiovascular system is highlighted