818 research outputs found
Beyond public health : the cultural politics of tobacco control in Hong Kong
This work provides cultural and political explanations on how and why cigarette smoking has increasingly become an object of intolerance and control in Hong Kong. Since the 1980s, the smoking population has been falling. Smoking behavior, sales and promotion of cigarette products have been under close surveillance by the government, medical experts and society at large. Cigarette smoking, as well as smokers, has increasingly been rejected and demonized in the public discourse. What are the conditions that make the growing intolerant discourses and practices against cigarette smoking possible and dominant? Why and how has the tobacco control campaign become prevalent as a governmentalist project, which is strong enough to tear down the alliance of tobacco industry giants? Why is tobacco singled out from other legal but harmful substances, such as alcohol, as an imperative object of intolerance and control? This work tackles these questions by adopting a Foucauldian discursive approach and the theory of articulation developed in cultural studies. By considering tobacco control as a historical and contextual practice, it traces the specific trajectory of tobacco control in Hong Kong, maps the cultural and political contexts that make it possible, and considers its consequence regarding the complex relationship among control, construction of risk, identity and freedom in society
Genome assembly and metabolic pathway reconstruction of Pantoea ananatis LMG 20103
Next generation of sequencing (NGS) technologies have taken life science research into a new era. With the rapid advances in these technologies and the associated reduction in overall costs, the sequencing and assembly of genomes have come within reach of most laboratories. Studies related to the evolution, ecology and biology of an organism now rely heavily on genomic data and obtaining a genome sequence has become an essential resource for the rapid progress and success of these studies. Pantoea ananatis is recognised as an emerging but rather unconventional pathogen capable of infecting a wide range of different hosts. Numerous plants of agricultural and economic importance including maize, rice, onion, pineapple, melon, sudan grass and Eucalyptus trees have been affected. With the outbreak of P. ananatis in a South African Eucalyptus nursery in 1998, it was realised that very little is known about this pathogen. A better understanding of the pathogenicity, metabolism and ecology of the bacterium is required to develop strategies for the control of the disease. During this study, the genome sequence of P. ananatis strain LMG 20103 was obtained using the Roche 454 technology. To aid in the assembly of this Eucalyptus pathogen’s genome sequence, the type strain of P. ananatis LMG 2665 was also sequenced using Illinima’s Genome Analyzer (GA). A draft assembly of P. ananatis LMG 20103, consisting of 117 contigs, was generated after optimization of the Newbler assembly parameters and comparison with other genome assemblies and genomes. This study demonstrated that the assembly could be completed using both in-vitro, and in-silico approaches such as contig scaffolding, gap closure with conventional PCR reactions and sequencing, manual curation and automated genome annotation. The final complete genome consisted of a 4 386 227 bp chromosome and a 317 146 bp mega-plasmid. With the complete genome sequence available, the reconstruction of metabolic network of P. ananatis LMG 20103 was attempted using two pathways reconstruction pipelines namely, Pathway Tools and Model SEED. It was found that missing metabolic reactions and incomplete pathways in the draft metabolic networks were mainly caused by incorrect gene annotations or bioinformatic errors during the automated network reconstruction. These two pipelines differed substantially in the way network reconstruction is undertaken. Performing a comparison between the two proposed networks, annotation errors could be detected and corrected. Although some improvement could be made to the predicted network further experimental data is still required to improve the accuracy of the draft metabolic network. Despite the amount of effort and cost, it is believed that the complete genome and a draft metabolic network of P. ananatis LMG 20103 will be a valuable resource for many subsequent studies to investigate the evolution and biology of this emerging plant pathogen. This information will be essential for the development of strategies to predict and control future disease outbreaks associated with this pathogen.Dissertation (MSc)--University of Pretoria, 2012.Microbiology and Plant Pathologyunrestricte
Insights of biosurfactant producing Serratia marcescens strain W2.3 isolated from diseased tilapia fish: a draft genome analysis
Background
Serratia marcescens is an opportunistic bacterial pathogen with broad range of host ranging from vertebrates, invertebrates and plants. S. marcescens strain W2.3 was isolated from a diseased tilapia fish and it was suspected to be the causal agent for the fish disease as virulence genes were found within its genome. In this study, for the first time, the genome sequences of S. marcescens strain W2.3 were sequenced using the Illumina MiSeq platform.
Result
Several virulent factors of S. marcescens such as serrawettin, a biosurfactant, has been reported to be regulated by N-acyl homoserine lactone (AHL)-based quorum sensing (QS). In our previous studies, an unusual AHL with long acyl side chain was detected from this isolate suggesting the possibility of novel virulence factors regulation. This evokes our interest in the genome of this bacterial strain and hereby we present the draft genome of S. marcescens W2.3, which carries the serrawettin production gene, swrA and the AHL-based QS transcriptional regulator gene, luxR which is an orphan luxR.
Conclusion
With the availability of the whole genome sequences of S. marcescens W2.3, this will pave the way for the study of the QS-mediated genes expression in this bacterium
Desire for experiential travel, avoidance of rituality and social esteem: An empirical study of consumer response to tourism innovation
AbstractThis study investigates tourist consumption responses toward tourism innovation. To measure tourist responses, this study posits three key consumption drivers, namely social esteem, desire for experiential travel, and avoidance against rituality of tourism settings (a subscale of need for uniqueness) and models consumers’ affective response within the context of tourism innovation. It involves 295 respondents in an empirical survey. The findings affirm the three drivers toward tourist consumption behavior. Avoidance of rituality reflects tourist preference toward tourism product and service innovation. Desire for experiential travel and the pursuit of social esteem signify tourism management and marketing innovation. Social esteem, need for status and creative choice have significant influence on tourists’ affective responses. Acquiring unique tourist products, desire for experiential travel and seeking social esteem are important motivations for tourist consumption. The implications of the study enrich the existing literature of consumer behavior and tourist consumption in response to tourism innovation
Development of an Energy-Efficient Rapid Microalgal Cell-Harvesting Method Using Synthesized Magnetic Nanocomposites
Due to high consumption and non-renewable nature of fossil fuels, rapid development of potential renewable energies such as biofuel derived from microalgae is necessary for achieving the goals of sustainable growth and carbon neutrality. However, the high energy consumption required for microalgal biomass harvesting is regarded as a major obstacle for large-scale microalgal biofuel production. In the present study, the marine green microalgae Tetraselmis sp. was used to investigate a rapid and energy-efficient biomass collection method among different methods such as gravity sedimentation, auto-flocculation (at target pH), flocculation by polymers followed by magnetic separation, and centrifugation. The results showed that sufficient high cell densities of microalgae were obtained under the optimized growth conditions after 21 days of cultivation, and the microalgae could be easily flocculated and collected by magnetic separation using synthesized magnetic nanocomposites. The results also showed that among the different methods, magnetic separation was more efficient for biomass harvesting because of its simple and fast processing steps as well as low energy consumption. However, further investigation on different target microalgal species and their cultivation conditions, such as salinity and medium pH, will be required before application for large-scale biofuel production in the future
Adaptive Uncertainty Estimation via High-Dimensional Testing on Latent Representations
Uncertainty estimation aims to evaluate the confidence of a trained deep
neural network. However, existing uncertainty estimation approaches rely on
low-dimensional distributional assumptions and thus suffer from the high
dimensionality of latent features. Existing approaches tend to focus on
uncertainty on discrete classification probabilities, which leads to poor
generalizability to uncertainty estimation for other tasks. Moreover, most of
the literature requires seeing the out-of-distribution (OOD) data in the
training for better estimation of uncertainty, which limits the uncertainty
estimation performance in practice because the OOD data are typically unseen.
To overcome these limitations, we propose a new framework using data-adaptive
high-dimensional hypothesis testing for uncertainty estimation, which leverages
the statistical properties of the feature representations. Our method directly
operates on latent representations and thus does not require retraining the
feature encoder under a modified objective. The test statistic relaxes the
feature distribution assumptions to high dimensionality, and it is more
discriminative to uncertainties in the latent representations. We demonstrate
that encoding features with Bayesian neural networks can enhance testing
performance and lead to more accurate uncertainty estimation. We further
introduce a family-wise testing procedure to determine the optimal threshold of
OOD detection, which minimizes the false discovery rate (FDR). Extensive
experiments validate the satisfactory performance of our framework on
uncertainty estimation and task-specific prediction over a variety of
competitors. The experiments on the OOD detection task also show satisfactory
performance of our method when the OOD data are unseen in the training. Codes
are available at https://github.com/HKU-MedAI/bnn_uncertainty.Comment: NeurIPS 202
Lexicon-phonology relationships in Cantonese-speaking children a cross-sectional and longitudinal investigation
"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, April 30, 2003."Thesis (B.Sc.)--University of Hong Kong, 2003.Also available in print.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science
Unravelling the genome of long chain N-acylhomoserine lactone-producing Acinetobacter sp. strain GG2 and identification of its quorum sensing synthase gene
Myriad proteobacteria use N-acyl homoserine lactone (AHL) molecules as quorum-sensing (QS) signals to regulate different physiological functions, including virulence, antibiotic production and biofilm formation. Many of these proteobacteria possess LuxI/LuxR system as the QS mechanism. Recently, we reported the 3.89 Mb genome of Acinetobacter sp. strain GG2. In this work, the genome of this long chain AHL-producing bacterium was unravelled which led to the molecular characterization of luxI homlogue, designated as aciI. This 552 bp gene was cloned and overexpressed in Escherichia coli BL21(DE3). The purified protein was approximately 20.5 kDa and is highly similar to several autoinducer proteins of LuxI family among Acinetobacter species. To verify the AHL synthesis activity of this protein, high resolution liquid chromatography-mass spectrometry analysis revealed the production of 3-oxo-dodecanoyl homoserine lactone and 3-hydroxy dodecanoyl homoserine lactone from induced E.coli harboring the recombinant AciI. Our data show for the first time, the cloning and characterization of the luxI homologue from Acinetobacter sp. strain GG2, and confirmation of its AHLs production. These data are of great significance as the annotated genome of strain GG2 has provided a valuable insight in the study of autoinducer molecules and its roles in QS mechanism of the bacterium
A PILOT STUDY OF MASTERY OF FUNDAMENTAL MOTOR SKILLS OF PRIMARY SCHOOL STUDENTS IN HONG KONG
The purpose of this study was to evaluate the current proficiency level of fundamental motor skills among primary students in Hong Kong. Three male and three female grade three students participated in this pilot study. The Test of Gross Motor Development Second Edition (TGMD-2) was employed. Four out of six students displayed an average mastery of the overall fundamental motor skills while two were rated as below average in their proficiency. The performance of the Locomotor subtests outweighed the performance of the Object Control subtests. Further studies with larger sample size and with subjects in different age groups will be conducted in order to have a better understanding of the mastery level of the whole school students and to suggest and implement appropriate intervention programs to improve their fundamental motor skills
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