Dermatitis flammeus - an emerging infection-related complication of atopic dermatitis

This journal suppl. contain abstracts of the 16th Medical Research Conference 2011OBJECTIVE: To investigate the clinical, microbiological, immunological and pathological features of a proposed novel complication of atopic dermatitis (AD) related to infection. DESIGN: Case series and retrospective analysis. SETTING: A tertiary university hospital and a private specialist dermatology clinic in Hong Kong. PATIENTS: Twenty patients were included between January 2008 and September 2010. MAIN OUTCOME MEASURES: Clinical characteristics, microbiological findings, therapeutic strategy and prognosis of the …published_or_final_versio

Effective E-Learning: Perspective of Adult Learners in Hong Kong

This article examines what constitute effective online learning from the perspective of students in web-enhanced programmes offered in Hong Kong. To investigate the success factors of e-Learning, as well as the role of Internet-based technologies in adult learning in Hong Kong, survey of students studying web-enhanced programmes was conducted in 2005. This survey is designed to 1) investigate students’ perception on how e-Learning technologies, student and teacher affect the learning process and 2) the enhancement to learning effectiveness brought by e-Learning. The implications for effective online adult learning in Hong Kong will be discussed. Technology should be used primarily as a tool and a communication device to enable human relationship and enhance interactiveness among learners. Even though student respondents perceived teacher as the imparter of wisdom, and demanded for teacher’s presence and heavy participation in the online environment, the new facilitating role of teachers should be promoted. Students should switch from a dependent role to a self-directed role and actively engage in the knowledge construction process in the online environment. The findings will provide useful reference for educators to enhance learning in adult education.published_or_final_versionCentre of Information Technology in Education, University of Hong Kong and Education and Manpower Bureau, the Government of the Hong Kong SA

Effective E-Learning: Perspective of Adult Learners in Hong Kong

This article examines what constitute effective online learning from the perspective of students in web-enhanced programmes offered in Hong Kong. To investigate the success factors of e-Learning, as well as the role of Internet-based technologies in adult learning in Hong Kong, survey of students studying web-enhanced programmes was conducted in 2005. This survey is designed to 1) investigate students’ perception on how e-Learning technologies, student and teacher affect the learning process and 2) the enhancement to learning effectiveness brought by e-Learning. The implications for effective online adult learning in Hong Kong will be discussed. Technology should be used primarily as a tool and a communication device to enable human relationship and enhance interactiveness among learners. Even though student respondents perceived teacher as the imparter of wisdom, and demanded for teacher’s presence and heavy participation in the online environment, the new facilitating role of teachers should be promoted. Students should switch from a dependent role to a self-directed role and actively engage in the knowledge construction process in the online environment. The findings will provide useful reference for educators to enhance learning in adult education.published_or_final_versionCentre of Information Technology in Education, University of Hong Kong and Education and Manpower Bureau, the Government of the Hong Kong SA

Phosphogenesis in the 2460 and 2728 million-year-old banded iron formations as evidence for biological cycling of phosphate in the early biosphere

The banded iron formation deposited during the first 2 billion years of Earth's history holds the key to understanding the interplay between the geosphere and the early biosphere at large geological timescales. The earliest ore-scale phosphorite depositions formed almost at approximately 2.0-2.2 billion years ago bear evidence for the earliest bloom of aerobic life. The cycling of nutrient phosphorus and how it constrained primary productivity in the anaerobic world of Archean-Palaeoproterozoic eons are still open questions. The controversy centers about whether the precipitation of ultrafine ferric oxyhydroxide due to the microbial Fe(II) oxidation in oceans earlier than 1.9 billion years substantially sequestrated phosphate, and whether this process significantly limited the primary productivity of the early biosphere. In this study, we report apatite radial flowers of a few micrometers in the 2728 million-year-old Abitibi banded iron formation and the 2460 million-year-old Kuruman banded iron formation and their similarities to those in the 535 million-year-old Lower Cambrian phosphorite. The lithology of the 535 Million-year-old phosphorite as a biosignature bears abundant biomarkers that reveal the possible similar biogeochemical cycling of phosphorus in the Later Archean and Palaeoproterozoic oceans. These apatite radial flowers represent the primary precipitation of phosphate derived from the phytoplankton blooms in the euphotic zones of Neoarchean and Palaoeproterozoic oceans. The unbiased distributions of the apatite radial flowers within sub-millimeter bands do not support the idea of an Archean Crisis of Phosphate. This is the first report of the microbial mediated mineralization of phosphorus before the Great Oxidation Event when the whole biosphere was still dominated by anaerobic microorganisms.published_or_final_versio

A method for estimating the instantaneous frequency of non-stationary heart sound signals

Practical signals such as speech, biomedical measurement and communications turn out to be extremely non-stationary and nonlinear time series. Traditional FFT-based power spectral analysis fails to deal with these transient signals. To provide more efficient way for investigating non-stationary and nonlinear signals with high time-frequency resolution and extract more information regarding the transient frequency features involved in the signals, a novel method based on the instantaneous frequency distribution is developed in this paper to provide the time-frequency distribution of the practical signals. The aim of this contribution is to explore the role that both empirical mode decomposition and Hilbert transform can be used to play in such practical signals. Both simulation and experimental results were presented and analyzed to demonstrate the power and effectiveness of the proposed new time-frequency distribution.published_or_final_versio

Compression-extension transition of continental crust in a subduction zone: A parametric numerical modeling study with implications on Mesozoic-Cenozoic tectonic evolution of the Cathaysia Block

The Cathaysia Block is located in southeastern part of South China, which situates in the west Pacific subduction zone. It is thought to have undergone a compression-extension transition of the continental crust during Mesozoic-Cenozoic during the subduction of Pacific Plate beneath Eurasia-Pacific Plate, resulting in extensive magmatism, extensional basins and reactivation of fault systems. Although some mechanisms such as the trench roll-back have been generally proposed for the compression-extension transition, the timing and progress of the transition under a convergence setting remain ambiguous due to lack of suit- able geological records and overprinting by later tectonic events. In this study, a numerical thermo-dynamical program was employed to evaluate how variable slab angles, thermal gradients of the lithospheres and convergence velocities would give rise to the change of crustal stress in a convergent subduction zone. Model results show that higher slab dip angle, lower convergence velocity and higher lithospheric thermal gradient facilitate the sub- duction process. The modeling results reveal the continental crust stress is dominated by horizontal compression during the early stage of the subduction, which could revert to a hori- zontal extension in the back-arc region, combing with the roll-back of the subducting slab and development of mantle upwelling. The parameters facilitating the subduction process also favor the compression-extension transition in the upper plate of the subduction zone. Such results corroborate the geology of the Cathaysia Block: the initiation of the extensional regime in the Cathaysia Block occurring was probably triggered by roll-back of the slowly subducting slab.published_or_final_versio

Effects of test conditions on shear behaviour of composite soil

Test conditions, such as shearing rate and normal stress, have been long recognised as influencing the measured shear strength of clays and sands. However, their influence on composite soils, which have a wide range of particle sizes, has attracted much less attention from researchers. In this study, a total of 35 direct shear tests at different shearing rates under different normal stresses were conducted on specimens prepared by mixing different proportions of kaolin and glass beads. The changes in volume and water content of sheared specimens and the mesostructure of shear surfaces were studied. The results reveal a positive correlation between volume change and deviation of water content between the shear zone and outer zones, suggesting that the shear-induced volume change occurred primarily in the shear zones. Moreover, high normal stress and low shearing rate produced a relatively small void ratio in the shear zones, facilitating volumetric contraction of the specimen and the development of polished and evenly slickensided shear surfaces. In addition, the residual friction angle of the specimens tested was found to decrease with the increase in normal stress. The high shearing rate caused an increase in residual strength in specimens with low fines fraction, and reduced it in specimens with high fines fraction.published_or_final_versio

Utility of infrared thermography for screening febrile subjects

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Detection of body temperature with infrared thermography: accuracy in detection of fever

Key Messages 1. Infrared thermography (IRT) for detecting body temperature is less accurate in women, elderly people, and those with fever. 2. The core temperature significantly but weakly correlates to the IRT temperatures obtained from frontal and lateral of the face, and the forehead. 3. Among the three areas, the forehead IRT temperature showed the largest discrepancy and poorest correlation with the core temperature. 4. If IRT is used, the lateral maximum temperature of the face should be used. A cut-off temperature of 36ºC gives 77% sensitivity and 74% specificity. 5. Owing to its weak correlation with the core temperature, IRT should not replace direct body temperature measurement in clinical situations.published_or_final_versio

Can non-interactive language input benefit young second-language learners?

To fully acquire a language, especially its phonology, children need linguistic input from native speakers early on. When interaction with native speakers is not always possible – e.g. for children learning a second language that is not the societal language – audios are commonly used as an affordable substitute. But does such non-interactive input work? Two experiments evaluated the usefulness of audio storybooks in acquiring a more native-like second-language accent. Young children, first- and second-graders in Hong Kong whose native language was Cantonese Chinese, were given take-home listening assignments in a second language, either English or Putonghua Chinese. Accent ratings of the children's story reading revealed measurable benefits of non-interactive input from native speakers. The benefits were far more robust for Putonghua than English. Implications for second-language accent acquisition are discussed.postprin