Showing papers by "The Chinese University of Hong Kong published in 1994"

Cantonese: A Comprehensive Grammar

Abstract: Matthews and Yip present a fresh and accessible description of the contemporary language. The book is organised by both syntactic categories and language functions, providing comprehensive treatment of grammatical structures and paying special attention to idiom and speech registers. Grammatical points are illustrated by authentic examples from films, advertising and conversation in Hong Kong. An extensive index, numbered paragraphs and generous use of cross references provide readers with easy access to the information they require. This grammar will be the standard reference for years to come.

The effects of management accounting systems, perceived environmental uncertainty and decentralization on managerial performance: A test of three-way interaction

Abstract: This study investigated the interaction effects of perceived environmental uncertainty (PEU), decentralization and management accounting systems (MAS) design on managerial performance. MAS design was defined in terms of perceived availability of two characteristics of information, which were scope and level of aggregation. The responses of 48 managers, drawn from a cross-section of Singapore companies, to a questionnaire survey were analysed by examining the regression equations for the three-way interaction model and the partial derivatives of the equations. The results indicated that decentralization and the availability of MAS information characteristics of broad scope and aggregation were associated with higher managerial performance under conditions of high PEU. Under conditions of low PEU, decentralization and the availability of MAS broad scope and aggregated information were associated with lower managerial performance.

Earnings Management and the Long-Term Market Performance of Initial Public Offerings

Abstract: We examine empirically whether earnings management as measured by discretionary accounting accruals explain post-issue stock return underperformance for IPO firms. We find that high discretionary accounting accruals are related to negative abnormal stock returns with high statistical significance. For example, a trading strategy of a short position in IPO firms with high discretionary accruals and a long position in IPOs with low discretionary accruals result in a mean (median) excess return of 102% (83.5%) in the 36-month period beginning after the first fiscal year end of the IPO. The evidence is consistent with Ritter's [1991] conjecture that investors are systematically overoptimistic about the growth prospects of IPO firms. The high discretionary accounting accruals seem to be associated with initial overoptimism of investors with subsequent revelations about the appropriateness of the accruals causing a subsequent downward revision in stock prices.

A prospective randomized trial comparing R1 subtotal gastrectomy with R3 total gastrectomy for antral cancer.

Abstract: OBJECTIVE: The authors determined if more radical surgery with extended lymphadenectomy improves the results of gastrectomy in patients with adenocarcinoma of the gastric antrum. SUMMARY BACKGROUND DATA: The overall survival in patients with gastric cancer is disappointing. Improved survival has been reported by Japanese authors. Whether this is because of a higher number of early gastric cancers in the Japanese series, different biologic behavior in Asians, or the adoption of radical surgery with lymphadenectomy remains unclear. METHODS: R1 subtotal gastrectomy with omentectomy and R3 total gastrectomy (omentectomy, splenectomy, distal pancreatectomy, lymphatic clearance of the celiac axis, and skeletonization of vessels in the porta hepatis) were evaluated in a prospective, randomized comparison. RESULTS: Fifty-five patients were randomized--25 to the R1 group and 30 to the R3 group. The two groups were comparable for age, sex, tumor size, TNM stage, and length of follow-up. The R3 group had a longer operating time (140 vs. 260 min; p < 0.05), a greater transfusion requirement (0 vs. 2 units, p < 0.05) and a longer hospital stay (8 vs. 16 days; p < 0.05) (medians; Mann-Whitney U test). The only postoperative death was in the R3 group and was caused by intra-abdominal sepsis. Fourteen patients in the R3 group developed left subphrenic abscesses. There were no major complications in the R1 group. Overall survival was significantly better in the R1 group (median survival estimated by Kaplan-Meier method, 1511 vs. 922 days, p < 0.05, log-rank test). CONCLUSIONS: R3 total gastrectomy can be performed with a low mortality, but it has a high morbidity because of intra-abdominal sepsis. The data do not support the routine use of R3 total gastrectomy for treatment of patients with antral cancer.

An Alternative Model for Mixtures of Experts

Abstract: We propose an alternative model for mixtures of experts which uses a different parametric form for the gating network. The modified model is trained by the EM algorithm. In comparison with earlier models--trained by either EM or gradient ascent--there is no need to select a learning stepsize. We report simulation experiments which show that the new architecture yields faster convergence. We also apply the new model to two problem domains: piecewise nonlinear function approximation and the combination of multiple previously trained classifiers.

Drawing and animation using skeletal strokes

Abstract: The use of skeletal strokes is a new vector graphics realization of the brush and stroke metaphor using arbitrary pictures as “ink” It is based on an idealized 2D deformation model defined by an arbitrary path Its expressiveness as a general brush stroke replacement and efficiency for interactive use make it suitable as a basic drawing primitive in drawing programs as well as windowing and page description systems This paper presents our drawing and animation system, “Skeletal Draw”, based on skeletal strokes The effectiveness of the system in stylish picture creation is illustrated with various pictures made with it Decisions made in the handling of sub-strokes in a higher order stroke and recursive strokes are discussed The general anchoring mechanism in the skeletal stroke framework allows any arbitrary picture deformation to be abstracted into a single stroke Its extension to piecewise continuous anchoring and the anchoring of shear angle and stroke width are explained We demonstrated how this mechanism allows us to build up powerful pseudo-3D models which are particularly useful in the production of 2 1/2 D cartoon drawings and animation Animation sequences have been made to illustrate the ideas, including a vector graphics based motion blurring technique

Treatment of inoperable hepatocellular carcinoma with intrahepatic arterial yttrium-90 microspheres: a phase I and II study

Abstract: Eighteen patients with inoperable hepatocellular carcinoma (HCC) were treated with intrahepatic arterial yttrium-90 microspheres. All these patients showed a lung shunting below 15% and a tumour-to-normal ratio higher than 2 as determined by diagnostic technetium-99m macroaggregated albumin (Tc-MAA) gamma scintigraphy. The treatment was given through an arterial port placed during laparotomy. The radiation doses to the liver and tumour were determined intraoperatively with a beta probe and liquid scintillation counting of multiple liver biopsies. The treatment was well tolerated without major complications. In all patients the tumour marker fell to a level which ranged from 41% to 0.2% of the pretreatment level. Tumour regression was found to be dose related. Progressive or static disease occurred in a higher proportion of patients whose tumours received 120 Gy (median survival = 55.9 weeks) than those whose tumours received lower doses (median survival = 26.2 weeks). This difference is statistically significant with P = 0.005. We conclude that yttrium-90 microsphere therapy is safe and that tumour response is dose related. A tumour dose of > 120 Gy is recommended.

Completeness and orthogonality of quasinormal modes in leaky optical cavities.

Abstract: It is shown that for the scalar analog of electrodynamics in one dimension, the quasinormal modes of a leaky cavity form a complete set inside the cavity, provided the cavity is defined by a discontinuity in the refractive index. This condition is sufficiently general to apply to a number of interesting examples. The quasinormal modes are also orthogonal under a modified definition of the inner product. The completeness and orthogonality hold even though the cavity is not a Hermitian system by itself. These properties allow the discrete quasinormal modes to be used as the basis for dynamics of the scalar wave in the cavity.

The prevalence of depressive symptoms and predisposing factors in an elderly Chinese population.

Abstract: In a survey of elderly Chinese aged 70 years and over living in Hong Kong selected by stratified random sampling, the prevalence of depression was determined using the 15-item Geriatric Depression Scale using a cut-off point of 8 (sensitivity 96.3% and specificity 87.5% for this population). Subjects with moderate to severe cognitive impairment (CAPE I/O score < or = 7) were excluded. There were 877 men and 734 women. The adjusted overall prevalence for this population was 29.2% for men and 41.1% for women. The prevalence increased with age in men and was higher in women than in men. Univariate analysis identified many factors in the following areas that were associated with depression: socioeconomic characteristics, functional ability, physical health and social support. Stepwise logistic regression identified 16 factors predictive of depression: socioeconomic characteristics, such as borderline living expenses and dissatisfaction with living arrangement; poor social support, such as absence of an informal carer when ill, few relatives to turn to, and infrequent contact with neighbours and friends; functional disability, as indicated by a Barthel Index < 15, urinary incontinence and inability to do housework; and poor physical health--poor self perceived health, poor vision, difficulty with chewing, history of mental illness, frequent hospital admissions and increased level of symptoms such as poor memory, constipation and dizziness. Some of these factors may be amenable to intervention, and such measures may be important in reducing the high prevalence of depression in elderly people.

Infantile torticollis: a review of 624 cases.

Abstract: We reviewed 624 cases of infantile torticollis in one centre over a period of 7 years. The incidence of torticollis was found to be 1.3% in Chinese children. Boy-to-girl ratio was 3:2. Obstetric histories of the mothers showed a total of 62.2% with difficult labour, breech deliveries, or caesarean section, and 6.04% had associated congenital anomalies. Of all the cases, 27.88% were found to be postural, 35.4% had torticollis that presented with sternomastoid tumor, and 36.7% presented with muscular torticollis alone. When limitation of neck range was considered, 36.7% had a passive rotation deficit > 15 degrees. In patients presenting in the early stages, 97% of all infantile torticollis cases resolved with conservative treatment, active stimulation, and a passive stretching program. For those responding to treatment, the mean treatment period was 30 degrees were more likely to need surgery. Presence of sternomastoid tumor alone was not found to increase the likelihood of surgery. Musculoskeletal sequelae after torticollis had resolved included intermittent head tilt and persistence of mild craniofacial asymmetry. We recommend continuous follow-up in cases of infantile torticollis, particularly in patients with progression of sternomastoid tumor to muscular torticollis.

A comparative analysis of ethical beliefs: A four country study

Abstract: This study examines the extent to which business students from Canada, Japan, Hong Kong, and Taiwan react differently to ethical dilemmas involving employees, supervisors, customers, suppliers, and business rivals. The empirical results show that the national origin of the students does have an impact on their reactions to particular ethical dilemmas. In addition, the results indicate that controlling for the problem of social desirability response bias is important to ensure the validity of the empirical findings.

Principal's Leadership as a Critical Factor for School Performance: Evidence from Multi‐Levels of Primary Schools 1

Abstract: This study aims to investigate how principal's leadership is related to school performance in terms of multi‐level indicators such as school's organizational characteristics, teachers’ gro...

Analysis of least congested path routing in WDM lightwave networks

Abstract: Analyzes an adaptive routing rule in a WDM lightwave network. Each switching node in the network may have a number of wavelength converters which can be used to resolve wavelength conflicts in multi-hop paths. The authors found that without any wavelength converters, the wavelength conflict possesses an inherent blocking to alternate route traffic and that the use of wavelength converter to resolve wavelength conflicts does not give any significant reduction of blocking probability. >

Benzodiazepines in the treatment of catatonic syndrome

Abstract: During a 5-month period, 18 (8%) of 212 patients admitted to a psychiatric unit affiliated to a teaching hospital were found to have a catatonic syndrome associated with various nonorganic mental disorders. Signs and symptoms of motor retardation predominated the clinical presentations. In the course of a prospective, open study, all 18 patients were challenged by a small dose of oral lorazepam or intramuscular diazepam. Catatonic signs and symptoms in 2 patients showed an immediate, complete, and sustained response to the medication. The remaining 16 patients were maintained on 1 of the 2 benzodiazepines for the next 48 h when their motor status was re-evaluated. Significant clinical improvement was detected in all but 2 patients. However, 9 patients needed electroconvulsive treatment to achieve further improvement. Short-term benzodiazepine administration proved to be a safe and effective treatment of the catatonic syndrome.

A prospective study of the prevalence of clear‐cut endocrine disorders and polycystic ovaries in 350 patients presenting with hirsutism or androgenic alopecia

Abstract: Objective To determine the frequency of polycystic ovaries (PCO) on ultrasound and the incidence of clearcut endocrine disorders leading to virilization in patients complaining of hirsutism or androgenic alopecia. The major purpose was to determine a coherent policy for the routine biochemical assessment of such women. Design A prospective study of women attending a joint skin/endocrine clinic complaining of these problems. Patients Three hundred and fifty consecutive women with hirsutism and/or androgenic alopecia were assessed. Measurements Baseline endocrine screens were conducted on two occasions and included measurement of serum testosterone, androstenedione, dehydroepiandrosterone sulphate, sex hormone binding globulin, LH, FSH, 17-hydroxyprogesterone and PRL. The ovaries were visualized by high-resolution pelvic ultrasound scanning. Results Eight women were identified with relevant endocrine disorders; of these, one was acromegalic and one had a microprolactinoma--in both cases the association may have been fortuitous. Three had clear-cut 21-hydroxylase deficiency, one a rare hepatic enzyme deficiency (11-reductase), one a virilizing adrenal carcinoma and one a Leydig cell tumour. The latter six cases all had persistently elevated levels of serum testosterone (> 5 nmol/l). In all, 13 women had baseline testosterone levels in excess of 5 nmol/l. Polycystic ovaries were present in 81% of the cases who had erratic cycles and 52% of those with regular cycles; PCO were present in two of the women with 21-hydroxylase deficiency and in the woman with 11-oxoreductase deficiency. The Leydig cell tumour (1.2 cm diameter) was not detected on ultrasound or CT scan. Conclusions For the exclusion of enzyme deficiencies and virilizing tumours clinical assessment and a single serum testosterone measurement will suffice.

An Antimatter spectrometer in space

Abstract: We discuss a simple magnetic spectrometer to be installed on a satellite or space station. The purpose of this spectrometer is to search for primordial antimatter to the level of antimatter/matter ≈10 −9 , improving the existing limits obtained with balloon flights by a factor of 10 4 to 10 5 . The design of the spectrometer is based on an iron-free, NdFeB permanent magnet, scintillation counters, drift tubes, and silicon or time projection chambers. Different design options are discussed. Typically, the spectrometer has a weight of about 2 tons and an acceptance of about 1.0 m 2 sr. The availability of the new NdFeB material makes it possible for the first time to put a magnet into space economically and reliably.

Impact of sequence-dependent setup time on job shop scheduling performance

Abstract: In a production system using multi-purpose and flexible machines, reducing setup time is an important task for better shop performance. Numerous cases were reported about successful reduction of setup times by standardization of setup procedures. However, setup times have not been eliminated and remain an important element of real production problems for production systems such as commercial printing, plastics manufacturing, metal processing, etc. It is especially critical when the setup time is sequence dependent. In this situation, shop performance cannot be effectively improved without the aid of an appropriate scheduling procedure. Review of the past studies shows that there has not been a significant amount of research done on the scheduling procedure for a dynamic job shop with sequence dependent setup times. This paper investigates the job shop scheduling problems that are complicated by sequence-dependent setup times. The study classifies and tests scheduling rules by considering whether setup tim...

A new algorithm for explicit adaptation of time delay

Abstract: By using an adaptive technique similar to the one developed by Etter and Stearns (1981), a novel constrained algorithm for explicit time delay estimation (TDE) is derived. The adaptive process provides an unbiased delay estimate and its respective performance surface, learning characteristics and delay variance will be given. The mean-square error surface, though a function of the estimated delay only, is multimodal and proper initialization is required to guarantee global convergence. Simulation results are included to validate the convergence behavior of the TDE system. >

A Region of Homozygous Deletion on Chromosome 9p21–22 in Primary Nasopharyngeal Carcinoma

Abstract: Using 21 microsatellite polymorphic markers spanning both p and q arms, we have performed detailed deletion mapping on chromosome 9 in 18 primary nasopharyngeal carcinomas. All 18 tumors were informative at multiple loci. Eleven of the 18 cases (61%) demonstrated allelic deletion of chromosome 9. Among these 11, 6 cases are likely to be tumors with monosomy of chromosome 9. The other 5 cases demonstrated partial deletion by showing multiple areas of allelic loss. In one of the 5 cases, a homozygous deletion region was identified which includes D9S126, D9S171, and IFNA loci at 9p21-22, situated between loci D9S161 (9p21) and D9S162 (9p21-22). The presence of a homozygous deletion strongly suggests the presence of tumor suppressor gene(s) involved in the tumorigenesis of nasopharyngeal carcinoma. The same region has been reported to include some potential tumor suppressor gene loci in other cancers. This is the first reported finding of frequent genetic loss observed on chromosome 9 in nasopharyngeal carcinomas in addition to allelic loss on chromosome 3p at specific regions. Our results suggest that tumorigenesis and progression of nasopharyngeal carcinomas, like other solid tumors, involves multiple genetic changes associated with the inactivation of tumor suppressor genes.

Decreased Minimum Alveolar Concentration of Isoflurane in Pregnant Humans

Abstract: BACKGROUND Minimum alveolar concentration (MAC) is decreased in pregnant animals, but this change has not been demonstrated in humans, probably because of ethical considerations. It is less problematic to determine MAC in pregnant women undergoing termination of pregnancy, however, and therefore we compared the MAC of isoflurane in these women with the MAC in matched nonpregnant women. METHODS Patients underwent inhalational induction of anesthesia with isoflurane and tracheal intubation. MAC was determined in each patient by testing the response to a 10-s, 50-Hz, 80-mA transcutaneous tetanic electrical stimulus to the ulnar nerve at varying concentrations of isoflurane. The end-tidal concentration of isoflurane was kept constant for 10 min before each stimulus and the concentration of isoflurane ultimately varied in steps of 0.05% until we obtained a sequence of three alternate responses (move, not move, move) or (not move, move, not move). MAC for each patient was taken as the mean of the two concentrations just permitting and just preventing movement. MAC for the group was taken as the median of the individual MAC values. A blood sample was taken immediately before induction of anesthesia for measurement of progesterone concentrations. Data were compared between groups by the Mann-Whitney test. RESULTS The median (range) MAC for isoflurane in the pregnant group, 0.775% (0.675-0.825), was less than that in the nonpregnant group, 1.075% (1.025-1.175) (P < 0.001). The median (range) plasma progesterone concentration in the pregnant group, 63.4 (0.8-106) nM, was greater than that in the nonpregnant group, 8.4 (0.7-66) nM (P < 0.02). CONCLUSIONS The MAC of isoflurane was reduced by 28% in pregnant women at 8-12 weeks' gestation compared with that of nonpregnant controls.

Customers′ Risk Perceptions of Electronic Payment Systems

Abstract: One reason for the slow adoption rate of Electronic Fund Transfer at Point‐of‐Sale (EFTPoS) is that consumers perceive that EFTPoS has a higher level of risk than other traditional payment methods. Makes use of a concept in consumer behaviour and perceived risk to study the differences of consumers′ risk perceptions among alternative payment methods and whether these perceptions will be affected by the size of purchase and EFTPoS usage experience. The major findings are: (1) EFTPoS has the lowest physical risk and highest financial risk, the credit card has the lowest psychological risk and highest time loss risk, while cash has the highest physical risk and lowest performance risk; (2) Physical risk, financial risk and time loss risk for cash payment are significantly higher when the purchase is large, while performance risk for EFTPoS and credit card payment is significantly higher when the purchase is small; and (3) users of EFTPoS have a significantly higher level of perceived financial and time loss ...

Aconitine poisoning due to chinese herbal medicines : a review

Abstract: Both "chuanwu", the main root of Aconitum carmichaeli, and "caowu", the root of A kusnezoffii, are believed to possess anti-inflammatory, analgesic and cardiotonic effects and have been used in Chinese materia medica mainly for the treatment of musculoskeletal disorders. They contain the highly toxic C19 diterpenoid alkaloids of aconitine, mesaconitine and hypaconitine. After ingestion, patients may present with signs and symptoms that are typical of aconitine poisoning. Death may occur from ventricular arrhythmias, which are most likely to occur within the first 24 h. Management of aconitine poisoning is essentially supportive. There are no adequate studies in humans to indicate the most effective treatment of the ventricular arrhythmias. All clinicians should be alerted to the potential toxicity of "chuanwu" and "caowu".

Nutritional Status of Elderly Patients during Recovery from Chest Infection and the Role of Nutritional Supplementation Assessed by a Prospective Randomized Single-blind Trial

Abstract: We examined changes in the nutritional status of elderly patients with chest infection for a period of 3 months after discharge from hospital, including the effects of nutritional supplementation on well-being and functional status as well as on nutritional indices. Eighty-one subjects admitted to an acute medical ward aged 65 years and over with chest infection were recruited consecutively, and randomized to receive supplement (500 ml of Ensure liquid daily) for 1 month, or no supplement, on discharge. Assessment at baseline, 1, 2 and 3 months included a questionnaire to determine health, mental and functional status, and anthropometric measurements. Biochemical nutritional status was assessed at baseline, 1 and 3 months, and dietary intake (24 h recall method) at 1 and 3 months. During recovery, both supplement and non-supplement groups showed improvement in various measures of well-being and biochemical status. In addition, the former group showed improvement in more anthropometric measurements, in thiamine and pyridoxine status, while the non-supplement group showed a lower level of functional ability after 3 months. Various measures of well-being and biochemical status of the water-soluble vitamins were better in the supplement groups. We conclude that nutritional supplementation may have a role in helping elderly patients to recover from chest infections.

Immunomodulatory and Anti-Tumour Polysaccharides from Medicinal Plants

Abstract: Many Chinese medicinal plants have immunomodulatory and anti-tumour activities. Most of the anti-tumour activities of these Chinese herbs are probably due to their immunostimulating polysaccharide components. A general scheme for the isolation and purification of the bioactive polysaccharides from naturally occurring medicinal plants is described. Hot-water extraction followed by various chromatographic methods are usually used to purify the bioactive polysaccharides. The different fractions separated from Chinese medicinal plants show a range of immunomodulatory and anti-tumour activities. The analytical methods used for monosaccharide sequence determination and structural elucidation of the bioactive polysaccharides are described, as are the tests used to evaluate their immunopharmacological activities, both in vitro and in vivo. The purification, characterization and structural elucidation of immunomodulatory polysaccharides from medicinal plants may have important implications in the immunotherapy of cancer and in the treatment of various other diseases.