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Post-secondary educational pathways of young people in Hong Kong: the influence of cultural capital
No full textAn earlier research project, conducted during 2008 to 2010, investigated the influence of cultural capital on post-secondary educational pathways of young people in Hong Kong, using the perspective of education, cultural and social reproduction of Pierre Bourdieu, the French sociologist of education, as the main theoretical framework. The research was conducted within Hong Kong\u27s political, social, cultural and educational contexts, which have been undergoing changes since Britain ended its colonial rule and China resumed sovereignty on 1st July 1997. Pierre Bourdieu\u27s concepts of cultural capital were used to study the extent of the influence of these changes on the post-secondary educational pathways of teenage girls in Hong Kong.
This article reflects on the local educational landscape and issues arisen, in relation to the government\u27s policy initiatives and the vastly fast expansion of the self-financed post-secondary education sectors since the completion of this research in 2010. Some issues and challenges include access and equity concerns; privatization of secondary education; entitlement versus perpetuation of social inequalities;neoliberal massification of higher education; and the growth of professional vocational education. In conclusion, noting the global powerful impact of information technologies and the social media, the article shares a need to review concepts of knowledge and learning, which may include citizenship education especially for young people in Hong Kong in the midst of political and social unrest in recent months. A novel definition of cultural capital (and social capital), and thus its affected influence on the post-secondary educational pathways of young people will be an interesting topic for future research in Hong Kong
Effects of an extra Trp113Tyr substitution on yeast D-amino acid oxidase variant
No full textBackground: β-Lactam antibiotics (cephalosporins and penicillins) are used in clinical practice to combat microbial infections. Commercial cephalosporins are all semi-synthetic and chemically derived from 7-aminocephalosporanic acid (7-ACA), a cephem nucleus that is traditionally produced by multi-step chemical reactions from cephalosporin C (CPC). However, the procedures are environmentally damaging, costly, and low yield [1]. The increasing annual demand for semi-synthetic cephalosporins and the concept of environmental sustainability have created a dire need to develop a \u27greener\u27 production of 7-ACA. 7-ACA can be enzymatically produced from CPC by a two-step process that involves D-amino acid oxidase (DAAO) and glutaryl-7-aminocephalosporanic acid (GL-7-ACA) acylase. Recently, we characterised the highly active and thermostable Trigonopsis variabilis DAAO (TvDAAO) variant F54Y for oxidative deamination of CPC. A single amino acid substitution at the 54th position of TvDAAO from phenylalanine (F) to tyrosine (Y) resulted in a 6-fold improvement in catalytic activity towards CPC and in thermostability after heat treatment at 55°C [2]. The potential application of the TvDAAO F54Y variant in the antibiotics industry as a simple and efficient biocatalyst was evaluated [3]. To further elucidate the structural basis of the catalytic activity and thermostability of TvDAAO F54Y, we investigated the role of the 113th amino acid residue (tryptophan, W113) that locates near the substrate binding cleft.
Methods: The W113 (tryptophan) residue of the TvDAAO F54Y variant was converted to tyrosine by the overlapping polymerase chain reaction using mutagenic primers. The mutations in the resultant TvDAAO variant, TvDAAO F54Y/W113Y, were confirmed by automated DNA sequencing. The variant was expressed in Escherichia coli BL21(DE3)pLysS. E. coli cells were harvested by centrifugation (2,400 g, 15 min) at 4°C and lysed in ice-cold 20 mM sodium phosphate (pH 7.0) supplemented with 1 mM phenylmethylsulphonyl fluoride by sonication (ten cycles, 15 sec each, at 15 sec intervals). The cell-free extract was clarified by centrifugation (13,000 g, 30 min) at 4°C, filtered through a 0.20 μm nylon membrane, and purified by a diethylaminoethyl-cellulose column and a HiLoad 16/60 Superdex 200 prep grade gel filtration column. Purity of the enzyme was analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and its concentration was determined by Bradford assay. The catalytic activity of the purified enzyme was determined by measuring the formation of GL-7-ACA at 22°C with agitation [3]. One mL of the reaction mixture contained 20 μg TvDAAO F54Y/W113Y variant, 5 mM cephalosporin C, and 50 mM sodium phosphate (pH 7.5). The amount of GL-7-ACA liberated was quantified by high performance liquid chromatography equipped with a C-18 reverse phase column, using 6% acetonitrile in 50 mM potassium phosphate (pH 7.5) as the mobile phase. Thermostability of the purified enzyme was evaluated by measuring the residual catalytic activity after heat treatment at 55°C for 30 min.
Results: The TvDAAO F54Y/W113Y variant was prepared and purified to homogeneity. Catalytic activity was increased by ~10% with respect to the original TvDAAO F54Y variant, but was deactivated by heat treatment.
Conclusions: The W113 of TvDAAO plays a pivotal role in thermal deactivation. W113Y substitution may alter the local spatial arrangement of the substrate binding cleft, and hence increase the vulnerability of the nearby oxidative-sensitive C108 [4], promoting deactivation of the enzyme at elevated temperatures
Innovative Self-Organization Wireless Sensor Networks for Electrical Power Systems
Get PDFWireless Sensor Networks (WSNs) gather information for electrical power systems and help to manage demand Response and demand side strategies. Optimization of WSNs depends on their physical deployment, and it will bring to the fore a very focused number of parameters to be optimized. Selforganization of WSNs is an important issue to be considered, and it requires the nodes to form a network by collaboration with each other without using manual intervention. Moreover, the WSNs implemented in electrical power systems should be secured and energy efficient in order to provide highly reliable data for monitoring and control.
In this paper, we will propose Self-Organization WSNs with Security and Energy-efficient Clustering algorithms (SOSEC) including cluster formation, data encryption keys establishment and management, and an energy efficient routing protocol. SOSEC can optimize the energy efficiency of the whole network and ensure a secured channel for data transmissions in WSNs for electrical power systems
Materialistic consumers who seek unique products: How does their need for status and their affective response facilitate the repurchase intention of luxury goods?”
No full textIt is generally known that status consumption fulfils the hedonic needs of luxury goods consumers; affective response generated from the purchase behavior of luxury goods is linked to the display of wealth and symbolic meanings obtained from social standing. However, there is a paucity of studies on how the affective response of consumers influences their repurchase intention of luxury goods. Therefore, in this paper, the repurchase intention of luxury goods consumers is investigated, their motivations are examined, and how status consumption affects their affective response will be demonstrated. The sample in this study comprises 568 survey respondents. The findings show that affective response has the strongest direct impact on repurchase intention. The need for uniqueness and materialism have indirect effects on repurchase intention through status consumption. Consequently, the results will enrich the existing literature on consumer behavior and provide theoretical and practical implications
Facilitating students\u27 project work with online collaborative support: A case from Business Administration Discipline at Hong Kong Institute of Vocational Education (Lee Wai Lee)
Get PDFMeasuring building performance for sustainable built heritage, surveying and built environment
No full textDespite a number of currently available building assessment methods, relatively little has been done on the assessment for sustainability of heritage buildings. It is important to measure the performance of a heritage building in achieving sustainability. The grading process often focuses on historical interest, architectural merits and social merits; and generally ignores the significance of environmental and economic impacts. There are also building assessment methods which focus on environmental sustainability only. This paper aims to develop a hierarchy to measure building performance of the built heritage from the three pillars of sustainability. A Heritage Building Sustainability Index (HBSI) would be described which incorporated a total of 19 indicators to benchmark performance in sustainability. Building owners, managers, government, and policymakers should make reference to these measurement metrics in order to move towards sustainability. These indicators will be useful for formulation of strategies for building restoration or adaptive re-use of heritage buildings
TaskRec: A task recommendation framework in crowdsourcing systems
No full textCrowdsourcing is evolving as a distributed problem-solving and business production model in recent years. In crowdsourcing paradigm, tasks are distributed to networked people to complete such that a company’s production cost can be greatly reduced. In crowdsourcing systems, task recommendation can help workers to find their right tasks faster as well as help requesters to receive good quality output quicker. However, previously proposed classification based task recommendation approach, which is the only one in the literature, does not consider the dynamic scenarios of new workers and new tasks in the crowdsourcing system. In this paper, we propose a Task Recommendation (TaskRec) framework based on a unified probabilistic matrix factorization, aiming to recommend tasks to workers in dynamic scenarios. Unlike traditional recommendation systems, workers do not provide their ratings on tasks in crowdsourcing systems, thus we infer user ratings from their interacting behaviors. This conversion helps task recommendation in crowdsourcing systems. Complexity analysis shows that our framework is efficient and is scalable to large datasets. Finally, we conduct experiments on real-world datasets for performance evaluation. Experimental results show that TaskRec outperforms the state-of-the-art approach
Meta-analysis of association between ALDH2 rs671 polymorphism and essential hypertension in Asian populations
No full textBackground: Mitochondrial aldehyde dehydrogenase-2 (ALDH2) is an enzyme that oxidizes acetaldehyde into acetic acid during alcohol metabolism. Many studies indicate that the rs671 GG genotype in the ALDH2 gene may play a critical role in increasing the risk of essential hypertension (EH) associated with alcohol consumption, which predominantly occurs in men. However, the literature is inconclusive in this regard. This meta-analysis aims to derive a more precise estimation of the relationship between the rs671 polymorphism and EH for both male and female drinkers and nondrinkers.
Methods: Ten cohort and case-control studies were included in the analysis with a total of 12,161 subjects; 7,062 patients and 5,099 healthy controls.
Results: Our results show that the rs671 GG genotype was associated with an increased risk of EH compared with the AG+AA genotype (OR = 1.27, 95 % CI = 1.17–1.37, p \u3c 0.00001). When comparing male and female subjects, only among male individuals was a higher risk of EH found in the GG genotype compared with the AG+ AA genotype (OR = 1.59, 95 % CI = 1.40–1.80, p \u3c 0.00001). By contrast, among female subjects, the risk of EH in the rs671 GG genotype did not differ from that detected in the AA + GG genotype. The proportion of patients with EH was significantly higher for the GG genotype carriers than for the AG+AA genotype carriers, both in the subset of drinkers (OR = 1.51, 95 % CI = 1.23–1.86, p \u3c 0.0001) and in that of nondrinkers (OR = 1.22, 95 % CI = 1.01–1.47, p = 0.03). In addition, among carriers of the GG genotype, the risk of EH among the drinkers was similar to that found in the nondrinkers’ subset (OR = 1.12, 95 %CI = 0.89–1.41, p = 0.34).
Conclusions: Our meta-analysis demonstrates that the rs671 GG genotype increases the risks of EH, especially in men, and is independent of alcohol consumption