830 research outputs found
Multilocus sequence analysis of phylogroup 1 and 2 oral treponeme strains
More than 75 ‘species-level' phylotypes of spirochete bacteria belonging to the genus Treponema reside within the human oral cavity. The majority of these oral treponeme phylotypes correspond to as-yet uncultivated taxa, or strains of uncertain standing in taxonomy. Here, we analyze phylogenetic and taxonomic relationships between oral treponeme strains using a multilocus sequence analysis (MLSA) scheme based on the highly-conserved 16S rRNA, pyrH, recA and flaA genes. We utilize this MLSA scheme to analyze genetic data from a curated collection of oral treponeme strains (n=71) of diverse geographical origins. This comprises phylogroup 1 (n=23) and phylogroup 2 (n=48) treponeme strains; including all relevant ATCC reference strains. The taxonomy of all strains was confirmed or inferred via the analysis of ca. 1,450 bp 16S rRNA gene sequences using a combination of bioinformatic and phylogenetic approaches. Taxonomic and phylogenetic relationships between the respective treponeme strains were further investigated by analyzing individual and concatenated flaA (1,074 nt), recA (1,377 nt) and pyrH (696 nt) gene sequence datasets. Our data confirmed the species differentiation between Treponema denticola (n=41) and Treponema putidum (n=7) strains. Notably, our results clearly supported the differentiation of the 23 phylogroup 1 treponeme strains into 5 distinct ‘species-level' phylotypes. These respectively corresponded to ‘Treponema vincentii' (n=11), Treponema medium (n=1); ‘Treponema sinensis' (T. sp. IA; n=4); Treponema sp. IB (n=3); and Treponema sp. IC (n=4). In conclusion, our MLSA-based approach can be used to effectively discriminate oral treponeme taxa, confirm taxonomic assignment, and enable the delineation of species boundaries with high confidence.published_or_final_versio
Factors influencing school connectedness: Chinese adolescents' perspectives
This study explored the concept of school connectedness and the factors that may influence its development with a sample of Chinese adolescents. Six focus groups involving 52 high school students were conducted using a set of predetermined discussion topics. Results indicated that the students fully understood the notion of school connectedness and could identify a number of key influences affecting its development. These factors could be grouped under several domains including teacher care, peer relations, broader school relationships, school disciplinary policies and practices, activities within the school's guidance and counseling program, and opportunities for talent development. The students were also able to suggest practical strategies that schools might introduce to enhance and strengthen students' acquisition of connectedness to school. The implications from the findings are discussed with particular reference to implementing comprehensive school guidance and counseling program in Hong Kong. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201
Enhancing life skills development: Chinese adolescents' perceptions
This study explored Chinese adolescents' perceptions of their own life skills development and the importance they place on such skills. The study also investigated the within-school and outsideschool influences that may help develop and enhance life skills development. Six focus groups involving 52 high school students were conducted, using a set of predetermined discussion topics. Results revealed students' awareness of many salient life skills, including those related directly to academic development, 'learning to learn', personal and social growth, and future career planning. The students were also able to suggest practical strategies that schools might use to further enhance students' life skills development. Contextual factors influencing the development of life skills appear to include not only experiences within the school curriculum and the guidance and counseling program, but also talent development opportunities, and family and peer relationships. The implications of the findings are discussed with particular reference to implementing comprehensive school guidance and counseling programs in Hong Kong. © 2010 NAPCE.postprin
Hospital Authority audit of the outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong
published_or_final_versio
Wall roughness induces asymptotic ultimate turbulence
Turbulence is omnipresent in Nature and technology, governing the transport
of heat, mass, and momentum on multiple scales. For real-world applications of
wall-bounded turbulence, the underlying surfaces are virtually always rough;
yet characterizing and understanding the effects of wall roughness for
turbulence remains a challenge, especially for rotating and thermally driven
turbulence. By combining extensive experiments and numerical simulations, here,
taking as example the paradigmatic Taylor-Couette system (the closed flow
between two independently rotating coaxial cylinders), we show how wall
roughness greatly enhances the overall transport properties and the
corresponding scaling exponents. If only one of the walls is rough, we reveal
that the bulk velocity is slaved to the rough side, due to the much stronger
coupling to that wall by the detaching flow structures. If both walls are
rough, the viscosity dependence is thoroughly eliminated in the boundary layers
and we thus achieve asymptotic ultimate turbulence, i.e. the upper limit of
transport, whose existence had been predicted by Robert Kraichnan in 1962
(Phys. Fluids {\bf 5}, 1374 (1962)) and in which the scalings laws can be
extrapolated to arbitrarily large Reynolds numbers
Copy number variation analysis based on AluScan sequences
BACKGROUND: AluScan combines inter-Alu PCR using multiple Alu-based primers with opposite orientations and next-generation sequencing to capture a huge number of Alu-proximal genomic sequences for investigation. Its requirement of only sub-microgram quantities of DNA facilitates the examination of large numbers of samples. However, the special features of AluScan data rendered difficult the calling of copy number variation (CNV) directly using the calling algorithms designed for whole genome sequencing (WGS) or exome sequencing. RESULTS: In this study, an AluScanCNV package has been assembled for efficient CNV calling from AluScan sequencing data employing a Geary-Hinkley transformation (GHT) of read-depth ratios between either paired test-control samples, or between test samples and a reference template constructed from reference samples, to call the localized CNVs, followed by use of a GISTIC-like algorithm to identify recurrent CNVs and circular binary segmentation (CBS) to reveal large extended CNVs. To evaluate the utility of CNVs called from AluScan data, the AluScans from 23 non-cancer and 38 cancer genomes were analyzed in this study. The glioma samples analyzed yielded the familiar extended copy-number losses on chromosomes 1p and 9. Also, the recurrent somatic CNVs identified from liver cancer samples were similar to those reported for liver cancer WGS with respect to a striking enrichment of copy-number gains in chromosomes 1q and 8q. When localized or recurrent CNV-features capable of distinguishing between liver and non-liver cancer samples were selected by correlation-based machine learning, a highly accurate separation of the liver and non-liver cancer classes was attained. CONCLUSIONS: The results obtained from non-cancer and cancerous tissues indicated that the AluScanCNV package can be employed to call localized, recurrent and extended CNVs from AluScan sequences. Moreover, both the localized and recurrent CNVs identified by this method could be subjected to machine-learning selection to yield distinguishing CNV-features that were capable of separating between liver cancers and other types of cancers. Since the method is applicable to any human DNA sample with or without the availability of a paired control, it can also be employed to analyze the constitutional CNVs of individuals.published_or_final_versio
Structure of hadron resonances with a nearby zero of the amplitude
We discuss the relation between the analytic structure of the scattering
amplitude and the origin of an eigenstate represented by a pole of the
amplitude.If the eigenstate is not dynamically generated by the interaction in
the channel of interest, the residue of the pole vanishes in the zero coupling
limit. Based on the topological nature of the phase of the scattering
amplitude, we show that the pole must encounter with the
Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the
dynamical component of the eigenstate is small if a CDD zero exists near the
eigenstate pole. We show that the line shape of the resonance is distorted from
the Breit-Wigner form as an observable consequence of the nearby CDD zero.
Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma
amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.Comment: 7 pages, 3 figures, v2: published versio
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Measurement of cosmic-ray muons and muon-induced neutrons in the Aberdeen Tunnel Underground Laboratory
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Decision Support System for the Response to Infectious Disease Emergencies Based on WebGIS and Mobile Services in China
Background: For years, emerging infectious diseases have appeared worldwide and threatened the health of people. The emergence and spread of an infectious-disease outbreak are usually unforeseen, and have the features of suddenness and uncertainty. Timely understanding of basic information in the field, and the collection and analysis of epidemiological information, is helpful in making rapid decisions and responding to an infectious-disease emergency. Therefore, it is necessary to have an unobstructed channel and convenient tool for the collection and analysis of epidemiologic information in the field. Methodology/Principal Findings: Baseline information for each county in mainland China was collected and a database was established by geo-coding information on a digital map of county boundaries throughout the country. Google Maps was used to display geographic information and to conduct calculations related to maps, and the 3G wireless network was used to transmit information collected in the field to the server. This study established a decision support system for the response to infectious-disease emergencies based on WebGIS and mobile services (DSSRIDE). The DSSRIDE provides functions including data collection, communication and analyses in real time, epidemiological detection, the provision of customized epidemiological questionnaires and guides for handling infectious disease emergencies, and the querying of professional knowledge in the field. These functions of the DSSRIDE could be helpful for epidemiological investigations in the field and the handling of infectious-disease emergencies. Conclusions/Significance: The DSSRIDE provides a geographic information platform based on the Google Maps application programming interface to display information of infectious disease emergencies, and transfers information between workers in the field and decision makers through wireless transmission based on personal computers, mobile phones and personal digital assistants. After a 2-year practice and application in infectious disease emergencies, the DSSRIDE is becoming a useful platform and is a useful tool for investigations in the field carried out by response sections and individuals. The system is suitable for use in developing countries and low-income districts
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
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