可譯與不可譯悼劉殿爵教授

踏莎行 送殿兒赴英倫 絕崤分携,危樓獨佇.萋萋草綠王孫去. 老來别易見應難,臨歧忍作傷心語.病掩孤檠,夢回疏杵.千山萬水愁風雨.東西南北總天涯,離魂隨汝知何處! 這是香港詞人番禺劉景堂(1887-1963)一九六○年所作,時年七十四歲.     

Migration and vascular lumen formation of endothelial cells in cancer cell spheroids of various sizes

We developed a microfluidic device to culture cellular spheroids of controlled sizes and suitable for live cell imaging by selective plane illumination microscopy (SPIM). We cocultured human umbilical vein endothelial cells (HUVECs) within the spheroids formed by hepatocellular carcinoma cells, and studied the distributions of the HUVECs over time. We observed that the migration of HUVECs depended on the size of spheroids. In the spheroids of ∼200 μm diameters, HUVECs migrated outwards to the edges within 48 h; while in the spheroids of ∼250 μm diameters, there was no outward migration of the HUVECs up to 72 h. In addition, we studied the effects of pro-angiogenic factors, namely, vascular endothelial growth factor (VEGF) and fibroblast growth factor (β-FGF), on the migration of HUVECs in the carcinoma cell spheroid. The outward migration of HUVECs in 200 μm spheroids was hindered by the treatment with VEGF and β-FGF. Moreover, some of the HUVECs formed hollow lumen within 72 h under VEGF and β-FGF treatment. The combination of SPIM and microfluidic devices gives high resolution in both spatial and temporal domains. The observation of HUVECs in spheroids provides us insight on tumor vascularization, an ideal disease model for drug screening and fundamental studies.     

Reproducing kernel resolution space and its applications—II

This paper extends the concept of a reproducing kernel resolution space to a Banach space setting. The resultant reproducing kernel resolution space, however, remains a Hilbert space thereby permitting a number of problems in mathematical system theory to be transformed from Banach space to Hilbert space. Particular emphasis is given to the study of Banach space valued random variables and the scattering operator formalism for an electric network.     

香港高职高专教育内容及课程体系改革

踏入21世纪香港制造及服务行业的产品及服务现况有如下特点：顾客主导；高度多元化；产品周期短；设计上须创新、具弹性及快速；存货量低。香港高职高专教学内容的改革将循以下方向发展：与工商企业更密切的联系；发展核心技能及重要的资历；确保职业教育的地位同样重要；推广持续及终生学习。     

Orientations to Enrolment of Part-time Students: A classification system based upon students' perceived lifelong learning needs

This article develops a classification system for the orientations to enrolment of part-time students based upon their practical lifelong learning needs. Orientation to enrolment is seen as a complex construct embodying all the reasons, purposes, expectations and motivations that cause students to pick a particular course and elect to study by the part-time mode. Virtually all of the interviewed students had a vocational orientation so some previously used categorisation schemes were not suitable. Instead seven categories relating to lifelong learning needs provided a scheme which covered the cases and related well to explanations given by interviewees for enrolling in the courses. These were re-training or further development for those who need to make a career shift; education for professionals who need to undertake continuing professional development through their careers; an opportunity for a tertiary education for those who did not previously have the chance; an education at the tertiary level for those who did not do sufficiently well at school to qualify for direct entry to university; an alternative to mainstream education; education for adults; and learning for pleasure throughout the lifetime.     

P2P searching trends: 2002–2004

This paper presents the trends of searching queries by users from peer-to-peer (P2P) networks over an 18-month period from July 2002 to January 2004. Four data sets of search queries collected from Gnutella were studied to describe the searching trends. Major findings include (1) the percentage of duplicate queries ranging from 34% to 68% of total queries; (2) an increase in non-English queries; (3) an approximately half of searching queries specified for video or audio file types; (4) the stop word “the” accounting for one-third of total stop words; (5) the shift of queries from audio to video; and (6) P2P users demanding for timely entertainment and porn materials. Based on the findings, it is worthwhile for P2P developers to consider (1) system design that allows effective searching using multiple languages; and (2) techniques that eliminate stop words for faster searching.     

Indexing response to intervention: a longitudinal study of reading risk from kindergarten through third grade

In this study, response to intervention and stability of reading performance of 41 kindergarten children identified as at risk of reading difficulty were evaluated from kindergarten through third grade. All students were assessed in the fall of each academic year to evaluate need for intervention, and students who fell below the 30th percentile on criterion measures received small-group supplemental intervention. Measures included a combination of commercial normative referenced measures and specific skill and construct measures to assess growth or change in reading risk status relative to 30th percentile benchmarks. Results indicated that consistent with the findings of prior research involving students with comparable entry-level performance, the majority of children identified as at risk in the beginning of kindergarten responded early and positively to intervention. On average, absolute performance levels at the end of kindergarten positioned students for trajectories of later reading performance that exceeded the 50th percentile on the majority of measures. Moreover, changes in risk status that occurred early were generally sustained over time. Only oral reading fluency performance failed to exceed the 30th percentile for the majority of students.     

Teachers as Disempowered and Demoralised Moral Agents: School Board Management and Teachers in Hong Kong

This study argues that teachers are disempowered and demoralised moral agents. Specifically, it uses a qualitative study of Hong Kong teachers to show that teachers’ agency in the pursuit of the moral goal of education is socially disempowered. The study shows that although teachers are committed to the moral goal of education, the obstacles to attaining this goal result in demoralisation. The difficulties consist of technical disempowerment (deprivation of power over one’s labour) and cognitive disempowerment (deprivation of power to identify the instructional value of teachers’ work), which are induced by managerialist educational reforms and school administration.     

Statistical extremes and peak factors in wind-induced vibration of tall buildings

In the structural design of tall buildings, peak factors have been widely used to predict mean extreme responses of tall buildings under wind excitations. Vanmarcke’s peak factor is directly related to an explicit measure of structural reliability against a Gaussian response process. We review the use of this factor for time-variant reliability design by comparing it to the conventional Davenport’s peak factor. Based on the asymptotic theory of statistical extremes, a new closed-form peak factor, the so-called Gamma peak factor, can be obtained for a non-Gaussian resultant response characterized by a Rayleigh distribution process. Using the Gamma peak factor, a combined peak factor method was developed for predicting the expected maximum resultant responses of a building undergoing lateral-torsional vibration. The effects of the standard deviation ratio of two sway components and the inter-component correlation on the evaluation of peak resultant response were also investigated. Utilizing wind tunnel data derived from synchronous multi-pressure measurements, we carried out a wind-induced time history response analysis of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building to validate the applicability of the Gamma peak factor to the prediction of the peak resultant acceleration. Results from the building example indicated that the use of the Gamma peak factor enables accurate predictions to be made of the mean extreme resultant acceleration responses for dynamic serviceability performance design of modern tall buildings.