297 research outputs found

    Vertical micro-injection machine

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    US7258543; US7258543 B2; US7258543B2; US7,258,543; US 7,258,543 B2; 7258543; Application No. 10/929,445Inventor name used in this publication: Kai Leung YungUS2007-2008 > Other Outputs > Patents grantedVersion of Recor

    Setting the stage for developing pre-service teachers' conceptions of good science teaching: The role of classroom videos

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    This paper reports findings about a curriculum innovation conducted at The University of Hong Kong. A CD-ROM consisting of videos of two lessons by different teachers demonstrating exemplary science teaching was used to elicit conceptions of good science teaching of student-teachers enrolled for the 1-year Postgraduate Diploma in Education at several stages during the programme. It was found that the videos elicited student-teachers' conceptions and had impact on those conceptions prior to the commencement of formal instruction. It has extended student-teachers' awareness of alternative teaching methods and approaches not experienced in their own schooling, broadened their awareness of different classroom situations, provided proof of existence of good practices, and prompted them to reflect on their current preconceptions of good science teaching. In several ways, the videos acted as a catalyst in socializing the transition of student-teachers from the role of student to the role of teacher. © 2006 Taylor & Francis.postprin

    Selection of solar energy for green building using superiority and inferiority multi-criteria

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    Author name used in this publication: K. M. YuVersion of RecordPublishe

    A hybrid model for molecular-dynamics simulations of semiflexible main-chain liquid-crystalline polymer melts

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    2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Virulence determinants, drug resistance and mobile genetic elements of Laribacter hongkongensis: a genome-wide analysis

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    <p>Abstract</p> <p>Background</p> <p><it>Laribacter hongkongensis </it>is associated with community-acquired gastroenteritis and traveler's diarrhea. In this study, we performed an in-depth annotation of the genes in its genome related to the various steps in the infective process, drug resistance and mobile genetic elements.</p> <p>Results</p> <p>For acid and bile resistance, <it>L. hongkongensis </it>possessed a urease gene cassette, two <it>arc </it>gene clusters and bile salt efflux systems. For intestinal colonization, it possessed a putative adhesin of the autotransporter family homologous to those of diffusely adherent <it>Escherichia coli </it>(<it>E. coli</it>) and enterotoxigenic <it>E. coli</it>. To evade from host defense, it possessed superoxide dismutase and catalases. For lipopolysaccharide biosynthesis, it possessed the same set of genes that encode enzymes for synthesizing lipid A, two Kdo units and heptose units as <it>E. coli</it>, but different genes for its symmetrical acylation pattern, and nine genes for polysaccharide side chains biosynthesis. It contained a number of CDSs that encode putative cell surface acting (RTX toxin and hemolysins) and intracellular cytotoxins (patatin-like proteins) and enzymes for invasion (outer membrane phospholipase A). It contained a broad variety of antibiotic resistance-related genes, including genes related to β-lactam (n = 10) and multidrug efflux (n = 54). It also contained eight prophages, 17 other phage-related CDSs and 26 CDSs for transposases.</p> <p>Conclusions</p> <p>The <it>L. hongkongensis </it>genome possessed genes for acid and bile resistance, intestinal mucosa colonization, evasion of host defense and cytotoxicity and invasion. A broad variety of antibiotic resistance or multidrug resistance genes, a high number of prophages, other phage-related CDSs and CDSs for transposases, were also identified.</p

    Environmental adaptability and stress tolerance of Laribacter hongkongensis: a genome-wide analysis

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    <p>Abstract</p> <p>Background</p> <p><it>Laribacter hongkongensis </it>is associated with community-acquired gastroenteritis and traveler's diarrhea and it can reside in human, fish, frogs and water. In this study, we performed an in-depth annotation of the genes in its genome related to adaptation to the various environmental niches.</p> <p>Results</p> <p><it>L. hongkongensis </it>possessed genes for DNA repair and recombination, basal transcription, alternative σ-factors and 109 putative transcription factors, allowing DNA repair and global changes in gene expression in response to different environmental stresses. For acid stress, it possessed a urease gene cassette and two <it>arc </it>gene clusters. For alkaline stress, it possessed six CDSs for transporters of the monovalent cation/proton antiporter-2 and NhaC Na<sup>+</sup>:H<sup>+ </sup>antiporter families. For heavy metals acquisition and tolerance, it possessed CDSs for iron and nickel transport and efflux pumps for other metals. For temperature stress, it possessed genes related to chaperones and chaperonins, heat shock proteins and cold shock proteins. For osmotic stress, 25 CDSs were observed, mostly related to regulators for potassium ion, proline and glutamate transport. For oxidative and UV light stress, genes for oxidant-resistant dehydratase, superoxide scavenging, hydrogen peroxide scavenging, exclusion and export of redox-cycling antibiotics, redox balancing, DNA repair, reduction of disulfide bonds, limitation of iron availability and reduction of iron-sulfur clusters are present. For starvation, it possessed phosphorus and, despite being asaccharolytic, carbon starvation-related CDSs.</p> <p>Conclusions</p> <p>The <it>L. hongkongensis </it>genome possessed a high variety of genes for adaptation to acid, alkaline, temperature, osmotic, oxidative, UV light and starvation stresses and acquisition of and tolerance to heavy metals.</p

    Environmental adaptability and stress tolerance of Laribacter hongkongensis: a genome-wide analysis

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    <p>Abstract</p> <p>Background</p> <p><it>Laribacter hongkongensis </it>is associated with community-acquired gastroenteritis and traveler's diarrhea and it can reside in human, fish, frogs and water. In this study, we performed an in-depth annotation of the genes in its genome related to adaptation to the various environmental niches.</p> <p>Results</p> <p><it>L. hongkongensis </it>possessed genes for DNA repair and recombination, basal transcription, alternative σ-factors and 109 putative transcription factors, allowing DNA repair and global changes in gene expression in response to different environmental stresses. For acid stress, it possessed a urease gene cassette and two <it>arc </it>gene clusters. For alkaline stress, it possessed six CDSs for transporters of the monovalent cation/proton antiporter-2 and NhaC Na<sup>+</sup>:H<sup>+ </sup>antiporter families. For heavy metals acquisition and tolerance, it possessed CDSs for iron and nickel transport and efflux pumps for other metals. For temperature stress, it possessed genes related to chaperones and chaperonins, heat shock proteins and cold shock proteins. For osmotic stress, 25 CDSs were observed, mostly related to regulators for potassium ion, proline and glutamate transport. For oxidative and UV light stress, genes for oxidant-resistant dehydratase, superoxide scavenging, hydrogen peroxide scavenging, exclusion and export of redox-cycling antibiotics, redox balancing, DNA repair, reduction of disulfide bonds, limitation of iron availability and reduction of iron-sulfur clusters are present. For starvation, it possessed phosphorus and, despite being asaccharolytic, carbon starvation-related CDSs.</p> <p>Conclusions</p> <p>The <it>L. hongkongensis </it>genome possessed a high variety of genes for adaptation to acid, alkaline, temperature, osmotic, oxidative, UV light and starvation stresses and acquisition of and tolerance to heavy metals.</p

    Development of a multi-locus sequence typing scheme for Laribacter hongkongensis, a novel bacterium associated with freshwater fish-borne gastroenteritis and traveler's diarrhea

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    <p>Abstract</p> <p>Background</p> <p>Laribacter hongkongensis is a newly discovered, facultative anaerobic, Gram-negative, motile, sea gull-shaped rod associated with freshwater fish borne gastroenteritis and traveler's diarrhea. A highly reproducible and discriminative typing system is essential for better understanding of the epidemiology of <it>L. hongkongensis</it>. In this study, a multilocus sequence typing (MLST) system was developed for <it>L. hongkongensis</it>. The system was used to characterize 146 <it>L. hongkongensis </it>isolates, including 39 from humans and 107 from fish.</p> <p>Results</p> <p>Fragments (362 to 504 bp) of seven housekeeping genes were amplified and sequenced. Among the 3068 bp of the seven loci, 332 polymorphic sites were observed. The median number of alleles at each locus was 34 [range 22 (<it>ilvC</it>) to 45 (<it>thiC</it>)]. All seven genes showed very low <it>d</it><sub><it>n</it></sub>/<it>d</it><sub><it>s </it></sub>ratios of < 0.04, indicating that no strong positive selective pressure is present. A total of 97 different sequence types (STs) were assigned to the 146 isolates, with 80 STs identified only once. The overall discriminatory power was 0.9861. eBURST grouped the isolates into 12 lineages, with six groups containing only isolates from fish and three groups only isolates from humans. Standardized index of association (<it>I</it><sup><it>S</it></sup><sub><it>A</it></sub>) measurement showed significant linkage disequilibrium in isolates from both humans and fish. The <it>I</it><sup><it>S</it></sup><sub><it>A </it></sub>for the isolates from humans and fish were 0.270 and 0.636, indicating the isolates from fish were more clonal than the isolates from humans. Only one interconnected network (<it>acnB</it>) was detected in the split graphs. The P-value (P = 0) of sum of the squares of condensed fragments in Sawyer's test showed evidence of intragenic recombination in the <it>rho, acnB </it>and <it>thiC </it>loci, but the P-value (P = 1) of maximum condensed fragment in these gene loci did not show evidence of intragenic recombination. Congruence analysis showed that all the pairwise comparisons of the 7 MLST loci were incongruent, indicating that recombination played a substantial role in the evolution of <it>L. hongkongensis</it>. A website for <it>L. hongkongensis </it>MLST was set up and can be accessed at <url>http://mlstdb.hku.hk:14206/MLST_index.html</url>.</p> <p>Conclusion</p> <p>A highly reproducible and discriminative MLST system was developed for <it>L. hongkongensis</it>.</p
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