Showing papers by "The Chinese University of Hong Kong published in 1989"
TL;DR: It is shown in a simple Hubbard model that through a mechanism calleduremath{\eta} pairing one can construct many eigenstates of the Hamiltonian possessing off-diagonal long-range order that are metastable and possess an energy gap.
Abstract: It is shown in a simple Hubbard model that through a mechanism called \ensuremath{\eta} pairing one can construct many eigenstates of the Hamiltonian possessing off-diagonal long-range order. The intrapair distance is small. It is shown that these eigenstates are metastable and possess an energy gap.
445 citations
TL;DR: In this paper, a new procedure, based on a within-culture standardization procedure, is introduced for this purpose, and a case study of the differences in the results produced by the cross-cultural and the new analyses is then used as a springboard for a further discussion of Shweder's between-within issue.
Abstract: In cross-cultural psychology a major goal is to identify dimensions of culture. For this purpose, the cross-cultural analysis (referred to as ecological analysis by Hofstede, 1980) is often used. Two methodological difficulties associated with this method are discussed, and their solution is proposed. A method intended to identify universal dimensions of individual difference, the pancultural analysis, is likely to produce results similar to those obtained in a cross-cultural analysis and hence is unable to achieve its purpose of identifying individual dimensions. A new procedure, based on a within-culture standardization procedure, is introduced for this purpose. A case study of the differences in the results produced by the cross-cultural and the new analyses is then used as a springboard for a further discussion of Shweder's(1973) between-within issue. The theoretical meaning of cultural and individual dimensions is also discussed.
438 citations
TL;DR: In this article, two novel channel assignment strategies are proposed: the locally optimized dynamic assignment (LODA) strategy and the borrowing with directional channel-locking (BDCL) strategy.
Abstract: Two novel channel-assignment strategies are proposed: the locally optimized dynamic assignment (LODA) strategy and the borrowing with directional channel-locking (BDCL) strategy. Their performance is compared with the fixed-assignment (FA) strategy (currently used on certain systems) and the borrowing with channel ordering (BCO) strategy (the strategy that has given the lowest blocking probability in previous research). Computer simulations on a 49-cell network for both uniform and nonuniform traffic showed that the average call-blocking probability of the BDCL strategy is always the lowest. The LODA performance is comparable with that of BCO under nonuniform traffic conditions but is inferior under uniform traffic conditions. >
401 citations
TL;DR: This paper used the Rochester Interaction Record (RIR) to investigate the effects of individualism-collectivism on everyday social interaction and found that individuals in the United States, an individualistic country, and in Hong Kong, which is highly collectivistic, maintained the RIR for 2 weeks.
Abstract: Used the Rochester Interaction Record (RIR) to investigate the effects of individualism-collectivism on everyday social interaction. Triandis (in press) defined collectivism as placing great emphasis on (a) the views, needs, and goals of the in-group rather than of oneself, (b) social norms and duty defined by the in-group rather than behavior to get pleasure, (c) beliefs shared with the in-group rather than beliefs that distinguish oneself from in-group, (d) great readiness to cooperate with ingroup members, and (e) intense emotional attachment to the in-group. University students in the United States, an individualistic country, and in Hong Kong, which is highly collectivistic, maintained the RIR for 2 weeks. Consistent with predictions, the Hoog Kong students had longer but fewer interactions (half as many) with fewer people, had a higher percentage of group and task interactions, and indicated greater self- and other-disclosure.
310 citations
TL;DR: It is concluded that in patients with perforated peptic ulcer, an initial period of nonoperative treatment with careful observation may be safely allowed except in patients over 70 years old, and that the use of such an observation period can obviate the need for emergency surgery in more than 70 percent of patients.
Abstract: To determine whether surgery could be avoided in some patients with perforated peptic ulcer, we conducted a prospective randomized trial comparing the outcome of nonoperative treatment with that of emergency surgery in patients with a clinical diagnosis of perforated peptic ulcer. Of the 83 patients entered in the study over a 13-month period, 40 were randomly assigned to conservative treatment, which consisted of resuscitation with intravenous fluids, institution of nasogastric suction, and intravenous administration of antibiotics (cefuroxime, ampicillin, and metronidazole) and ranitidine. Eleven of these patients (28 percent) had no clinical improvement after 12 hours and required an operation. Two of the 11 had a perforated gastric carcinoma, and 1 had a perforated sigmoid carcinoma. The other 43 patients were assigned to immediate laparotomy and repair of the perforation. One of these patients was found to have a perforated gastric carcinoma. The overall mortality rates in the two groups were similar (two deaths in each, 5 percent), and did not differ significantly in the morbidity (infection, cardiac failure, or renal failure) rates (40 percent in the surgical group and 50 percent in the nonsurgical group). The hospital stay was 35 percent longer in the group treated conservatively. Patients over 70 years old were less likely to respond to conservative treatment than younger patients (P less than 0.05). We conclude that in patients with perforated peptic ulcer, an initial period of nonoperative treatment with careful observation may be safely allowed except in patients over 70 years old, and that the use of such an observation period can obviate the need for emergency surgery in more than 70 percent of patients.
272 citations
TL;DR: Sodium fluoride takes effect slowly but effectively in preserving glucose in blood for at least three days, and its use is unnecessary if the concentration of glucose is to be measured within the first hour after sampling.
Abstract: How effective is sodium fluoride as a preservative of blood glucose? We compared changes in glucose concentration in fluoride-treated blood specimens with those of heparin-treated specimens. The former declined rapidly during the first hour; thereafter the rate of decrease was slower, and after 4 h the glucose concentration in the blood samples remained stable for up to three days. In contrast, the glucose concentration in the heparin-containing samples declined continuously. During the first hour, however, the rates of decline in the two types of samples were similar. Evidently sodium fluoride takes effect slowly but effectively in preserving glucose in blood for at least three days. Its use, however, is unnecessary if the concentration of glucose is to be measured within the first hour after sampling.
270 citations
11 Jun 1989
TL;DR: The locally optimized dynamic assignment (LODA) strategy and the borrowing with directional channel locking (BDCL) strategy are proposed and computer simulations show that the average call-blocking probability of the BDCL strategy is always the lowest.
Abstract: Two new channel assignment strategies are proposed. They are the locally optimized dynamic assignment (LODA) strategy and the borrowing with directional channel locking (BDCL) strategy. Their performance is compared with the fixed assignment (FA) strategy (currently used on certain systems) and the borrowing with channel ordering (BCO) strategy (the stability that has given the lowest blocking probability in previous research). Computer simulations on a 49-cell network for both uniform and nonuniform traffic show that the average call-blocking probability of the BDCL strategy is always the lowest. The LODA performance is comparable with BCO under nonuniform traffic conditions but is inferior under uniform traffic conditions. >
205 citations
TL;DR: 105 patients with acute calculous cholangitis who did not respond to conservative management underwent urgent endoscopic drainage of the biliary system at a mean of 1.5 days after admission, and there were no deaths in the group without shock irrespective of the timing of drainage.
190 citations
TL;DR: It is found that subjects with residence of long duration in rural areas, with engagement in farming, with previous use of herbicides and pesticides, and with habitual consumption of raw vegetables had a statistically significantly increased risk of PD.
Abstract: In our cross-sectional survey of the residents of homes for the elderly in 2 Hong Kong districts--Shatin and Tai Po--we found that 3.4% of the subjects had Parkinson's disease (PD). There was no sex difference in the disease rate. We also conducted a case-control study to determine the associated factors of PD. We found that subjects with residence of long duration in rural areas, with engagement in farming, with previous use of herbicides and pesticides, and with habitual consumption of raw vegetables had a statistically significantly increased risk of PD. This study tends to support the hypothesis that environmental factors directly or indirectly related to agricultural activities are associated with the development of PD.
186 citations
TL;DR: In this paper, a cross-cultural study of leadership style has been conducted to distinguish adequately between global characterizations of style and the specific behaviours which leaders need to use in a given culture if a particular style is to be attributed to them.
Abstract: It is proposed that cross-cultural studies of leadership style have failed to distinguish adequately between global characterizations of style and the specific behaviours which leaders need to use in a given culture if a particular style is to be attributed to them. A study is reported of perceptions of electronics plant supervisors in Britain, the USA, Japan and Hong Kong, derived from Misumi's PM leadership theory. The findings indicate that characterizations of P(Performance) and M(Maintenance) leader style have a similar factor structure in each culture. However, the specific behaviours associated with those styles differ markedly, in ways which are comprehensible within the cultural norms of each setting. The study illustrates how a series of emic correlations within each culture sample may be used to test the validity of etic models of leader style.
184 citations
TL;DR: It is found that pictorial, between-language, and within-language primes produced comparable effects of semantic facilitation, in line with the hypothesis that lexical items in different languages and pictures are processed by means of an amodal conceptual system.
Abstract: In two experiments, semantic facilitation and translation priming effects in Chinese-English bilingual speakers were demonstrated with a lexical decision task. A 300-msec stimulus-onset asynchrony (SOA) was used between display of the prime and the target item. Experiment 1 showed that subjects' lexical decision responses were facilitated to a greater extent when primed by a translation equivalent than a semantically related between-language word. In Experiment 2, we found that pictorial, between-language, and within-language primes produced comparable effects of semantic facilitation. These results are in line with the hypothesis that lexical items in different languages and pictures are processed by means of an amodal conceptual system.
01 Aug 1989
TL;DR: In this paper, the authors show how to convert the order-8 cosine transforms into a family of integer cosine transform (ICTs) using the theory of dyadic symmetry.
Abstract: The paper shows how to convert the order-8 cosine transforms into a family of integer cosine transforms (ICTs) using the theory of dyadic symmetry. The new transforms can be implemented using simple integer arithmetic. It was found that performance close to that of the DCT can be achieved with an ICT that requires only 4 bits for representation of its kernel com- ponent magnitude. Better performance can be achieved by some ICTs whose kernel components require longer bit lengths for representation. ICTs that require 3 bits or less for representation of their component magnitude are available but with degraded performance. The availability of many ICTs provides an engineer the freedom to tradeoff performance for simple implementation in design- ing a transform codec.
TL;DR: In this paper, an analysis of a thin cylindrical-rectangular microstrip patch antenna is presented, where the electric field under the curved patch and the resonant frequencies using the cavity model are obtained by considering the equivalent magnetic current radiating in the presence of a cylinrical surface.
Abstract: An analysis is presented of a thin cylindrical-rectangular microstrip patch antenna. After obtaining the electric field under the curved patch and the resonant frequencies using the cavity model, the far-field is found by considering the equivalent magnetic current radiating in the presence of a cylindrical surface. The input impedance and the total Q-factor are then calculated. Numerical and graphical results are presented to illustrate the effect of curvature on the characteristics of the TM/sub 10/ and TM/sub 01/ modes. >
10 Jul 1989
Journal Article•
TL;DR: The regionalisation of cell fate in the embryonic ectoderm was studied by analyzing the distribution of graft-derived cells in the chimaeric embryo following grafting of wheat germ agglutinin--gold-labelled cells and culturing primitive-streak-stage mouse embryos.
Abstract: The regionalisation of cell fate in the embryonic ectoderm was studied by analyzing the distribution of graft-derived cells in the chimaeric embryo following grafting of wheat germ agglutinin—gold-labelled cells and culturing primitive-streak-stage mouse embryos. Embryonic ectoderm in the anterior region of the egg cylinder contributes to the neuroectoderm of the prosencephalon and mesencephalon. Cells in the distal lateral region give rise to the neuroectoderm of the rhombencephalon and the spinal cord. Embryonic ectoderm at the archenteron and adjacent to the middle region of the primitive streak contributes to the neuroepithelium of the spinal cord. The proximal-lateral ectoderm and the ectodermal cells adjacent to the posterior region of the primitive streak produce the surface ectoderm, the epidermal placodes and the cranial neural crest cells. Some labelled cells grafted to the anterior midline are found in the oral ectodermal lining, whereas cells from the archenteron are found in the notochord. With respect to mesodermal tissues, ectoderm at the archenteron and the distal-lateral region of the egg cylinder gives rise to rhombencephalic somitomeres, and the embryonic ectoderm adjacent to the primitive streak contributes to the somitic mesoderm and the lateral mesoderm. Based upon results of this and other grafting studies, a map of prospective ectodermal tissues in the embryonic ectoderm of the full-streak-stage mouse embryo is constructed.
TL;DR: Le diagnostic de «syndrome de mort subite du nourrisson» est fait pour 9 garcons et 12 filles, tous de race chinoise, le syndrome est moins frequent a Hong Kong que dans d'other pays.
Abstract: 51 nourrissons morts sans cause evidente sont autopsies. Le diagnostic de «syndrome de mort subite du nourrisson» est fait pour 9 garcons et 12 filles, tous de race chinoise. Le syndrome est moins frequent a Hong Kong que dans d'autres pays. Les entretiens avec les parents et l'entourage permettent d'envisager certains facteurs de risque dans le mode de vie
TL;DR: In this paper, two approaches to the interpretation of and theorizing about cross-cultural differences are identified: the individual-level approach, where cultural differences are assumed to be consistent with individual differences within each of the cultures included in the cross-culture comparison, and the culture level approach, the culture is the unit of analysis and there is no assumption regarding the correspondence between culture-and individual level relationships.
Abstract: Two approaches to the interpretation of and theorizing about cross-cultural differences are identified. In the individual-level approach, cultural differences are assumed to be consistent with individual differences within each of the cultures included in the cross-cultural comparison. The use of antecedent variables to eliminate alternative explanations based on biases is reviewed and some problems noted. It is suggested that explicit theories be used to guide the selection of antecedent variables to minimize the impact of cultural biases. In the second approach, the culture-level approach, culture is the unit of analysis and there is no assumption regarding the correspondence between culture- and individual-level relationships. Two examples are given to illustrate the potential usefulness of this approach to developing concepts and theories that are very different from those derived from the individual-level approach. The problems of bias in this level of analysis are also discussed. Finally, i...
TL;DR: The rarity of the disorder in the East could be related to protective biological and sociocultural factors specific to the Chinese, and while it may become more common, anorexia nervosa is unlikely to reach Western proportions.
Abstract: Anorexia nervosa is a geographically distinct psychiatric disorder; it is rapidly increasing in incidence in Western countries, while being virtually unreported in China, or in the Chinese community of Hong Kong. This is surprising when the Chinese preoccupation with food and their reported readiness to somatise dysphoria are considered. Three Chinese anorectics born and living in Hong Kong and exhibiting mostly typical clinical features are reported. The rarity of the disorder in the East could be related to protective biological and socio-cultural factors specific to the Chinese, and while it may become more common, anorexia nervosa is unlikely to reach Western proportions.
TL;DR: In a 1400-bedded teaching hospital single-day prevalence surveys of hospital infection, infection control policies can have substantial impact on the prevalence of hospital-acquired infection, and their effectiveness can readily be measured by repeated prevalence surveys.
TL;DR: In this article, a prospective study using the principle of ligamentotoxis and primary cancellous bone grafting as the uniform method of treatment of comminuted fractures in the distal radius has been made.
Abstract: The conventional treatment of comminuted fractures in the distal radius has been unsatisfactory. We therefore made a prospective study using the principle of ligamentotoxis and primary cancellous bone grafting as the uniform method of treatment. Ligamentotaxis was maintained by using an external fixator for three weeks only, after which a carefully monitored programme of rehabilitation was given. We have reviewed 72 consecutive distal radial fractures after a follow-up of 7 to 40 months (average 11 months). Reduction had been maintained during healing and over 80% of patients regained full range of movement in hands, wrists and forearms with strong and pain-free wrist function. Complications were infrequent and gave no real problems. We conclude that distraction, external fixation and bone grafting appears to be an excellent method of treating comminuted fractures of the distal radius.
TL;DR: Three undifferentiated nasopharyngeal carcinoma (NPC) tumour lines were successfully established from fresh biopsy material injected s.c. into athymic mice and passaged for many generations, and three xenografts were found to be free of infiltrating lymphoid cells and remained und differentiated up to passage 30.
Abstract: Three undifferentiated nasopharyngeal carcinoma (NPC) tumour lines were successfully established from fresh biopsy material injected s.c. into athymic mice and passaged for many generations. These xenografts were found to be free of infiltrating lymphoid cells and remained undifferentiated up to passage 30. They were designated NPC/HK2117 (Xeno-1), NPC/HK1915 (Xeno-2) and NPC/HK1530 (Xeno-3), respectively. Passage 16 from Xeno-1, passage 1 from Xeno-2 and passage 14 from Xeno-3 were studied cytogenetically using G-banding with the trypsin-Giemsa method. Two xenografts were hyperdiploid with chromosome modal numbers ranging from 49 to 76, and one was hypodiploid with modal numbers ranging from 28 to 38. Five marker chromosomes have been identified with involvement of chromosomes 1, 3, 11, 12 and 17. Marker chromosomes derived from chromosomes 12q, 1q and 3q were consistent in one of the 2 xenografts successfully G-banded, and chromosomes 12, 11 and 17 were consistent in another. Three out of the 6 markers involve 12q13----qter. An abnormal chromosome 3 with most of the p arm deleted was also observed.
TL;DR: The findings generally suggest that the Chinese GHQ-30 is a valid instrument that assesses "general" psychological health, and the data provide support for the validity of some of the factorial dimensions of this scale.
Abstract: The Chinese version of the General Health Questionnaire-30 was administered to 2,150 Chinese secondary school students, along with several other scales that measure somatic and psychological symptoms. GHQ scores were found to correlate significantly with all other measures of psychopathology for the various samples. Further analyses indicated that while the GHQ correlated more strongly with scales that assess acute symptoms than with scales that measure chronic problems, GHQ correlations were higher with measures of state as well as trait anxiety relative to indices that primarily reflect non-anxiety-related symptoms. Correlations between the various factor scores of the GHQ and other indices of psychopathology also were found to be mostly significant. These findings generally suggest that the Chinese GHQ-30 is a valid instrument that assesses "general" psychological health, and the data provide support for the validity of some of the factorial dimensions of this scale.
TL;DR: There was an overall improvement of the actuarial survival rate and disease-free survival rate over the historical control, and its significance is discussed.
Abstract: Four hundred and seven cases of nasopharyngeal carcinoma were analyzed retrospectively; 403/407 were evaluable for recurrence and survival. Parapharyngeal boost significantly decreased local recurrences in parapharyngeal diseases without base of skull involvement (T2p), but not with base of skull involvement (T3p). Enhanced local control of T2p with boost was significant without neoadjuvant chemotherapy. Tumors localized within the nasopharynx (T1) and tumors with nasal involvement (T2n) suffering from local persistences after external radiation therapy were treated with an intracavitary afterloading method. They had survival and recurrence rates comparable to complete responders to external radiation therapy. Patients with bulky cervical nodes (maximal diameter ≥ 4 cm, N1–N3), treated with neoadjuvant chemotherapy with cis-diamminedichloroplatinum 11 and 5-fluorouracil, had a regional failure rate, distant metastasis rate, actuarial survival rate, and disease-free survival rate comparable to those with smaller nodes treated with external radiation therapy alone. A simple modification of the Ho's classification by regrouping the T-stages into `early T-stages' and `advanced T-stages' and by combining the N1 and the N2 has greatly increased the power of the system in predicting local recurrence and distant metastasis, respectively. There was an overall improvement of the actuarial survival rate and disease-free survival rate over the historical control, and its significance is discussed.
TL;DR: The soil amendment effects of fly ash, a byproduct of coal-powered energy production, were examined during germination tests of two vegetable species in this article, and the results indicated that low ash amendment at 3% improved young seedling growth of both crops, but high ash amendment (12 and 30%) produced adverse effects on growth.
TL;DR: Wang et al. as mentioned in this paper showed that recombinant alpha 2 interferon (rIFN) is superior to doxorubicin in causing more tumour regression, less serious marrow suppression and less fatal complications.
Abstract: In a prospective trial of 75 Chinese patients with histologically proven inoperable hepatocellular carcinoma (HCC), 25 patients were randomised to receive doxorubicin 60-75 mg m-2 intravenously once every 3 weeks, 25 to receive recombinant alpha 2 interferon (rIFN) (Roferon) 9-18 x 10(6) IU m-2 intramuscularly (i.m.) daily and 25 to receive rIFN 25-50 x 10(6) IU m-2 i.m. three times weekly. Patients were switched to the other drug if: (a) there was progressive disease after 12 weeks, (b) unacceptable toxicity developed and (c) they had received a total of 500 mg m-2 of doxorubicin. Six patients had switching over of therapy, three on doxorubicin and three on rIFN. In the remaining 69 patients on single drug therapy, the median survival rate of patients on doxorubicin and rIFN was 4.8 and 8.3 weeks respectively (P = ns.). rIFN induced tumour regression of 25-50% in 12% of patients and of over 50% in 10% of patients. When compared with doxorubicin, rIFN was associated with more tumour regression (P = 0.00199) and less progressive tumours (P = 0.00017). It caused less prolonged and less severe marrow suppression (P = 0.01217), and had significantly less fatal complications than doxorubicin (P = 0.01383). Doxorubicin caused fatal complications due to cardiotoxicity and neutropenia in 25% of patients. rIFN was associated with fatal complications due to dementia and renal failure in 3.8% of patients. In the treatment of inoperable HCC, rIFN is superior to doxorubicin in causing more tumour regression, less serious marrow suppression and less fatal complications.
TL;DR: Results of the bacteriological and morphological studies confirmed the close relationship between the presence of bacteria and the development of brown pigment stones.
Abstract: Bacteriological and morphological studies of 38 brown pigment common duct stones were performed. Stone cultures were positive for bacteria in 80.5% of those studied. Enterococci were the most common organisms that were isolated. Scanning electron microscopy showed the presence of bacteria in 84.2% of the stones. The bacteria were seen embedded within an amorphous matrix in alternating layers of flakelike crystals. Transmission electron microscopy showed the presence of gram-positive and gram-negative bacteria surrounded by a ruthenium red-stained exopolysaccharide material. Results of the bacteriological and morphological studies confirmed the close relationship between the presence of bacteria and the development of brown pigment stones.
TL;DR: In this article, the authors examined the municipal peak and kilowatt-hour demand for electricity in Ontario, and explored the issue of homogeneity across geographic regions, and proposed various procedures which deal with this heterogeneity and yet reduce the multicollinearity problems associated with regional specific demand formulations.
TL;DR: In this article, a systematic approach is adopted to extract an effective low-energy Hamiltonian for crystals with a slowly varying inhomogeneity, resolving several controversies, and it is shown that the effective mass m(R) is, in general, position dependent, and enters the kinetic energy operator as -
Abstract: A systematic approach is adopted to extract an effective low-energy Hamiltonian for crystals with a slowly varying inhomogeneity, resolving several controversies. It is shown that the effective mass m(R) is, in general, position dependent, and enters the kinetic energy operator as -\ensuremath{
abla}[m${(\mathrm{R})}^{\mathrm{\ensuremath{-}}1}$]\ensuremath{
abla}/2. The advantage of using a basis set that exactly diagonalizes the Hamiltonian in the homogeneous limit is emphasized.
TL;DR: The authors studied optimal birth control policies for an age-structured population of McKendrick type which is a distributed parameter system involving 1st order partial differential equations with nonlocal bilinear boundary control.