Spatial Dynamics of the Severe Acute Respiratory Syndrome (SARS) Epidemic in Hong Kong in 2003

The Severe Acute Respiratory Syndrome (SARS) epidemic in 2003 was the first infectious disease outbreak caused by a novel pathogen in the twenty-first century. The outbreak in Hong Kong was the second largest worldwide and was characterised by a large proportion of hospital infections and a super-spreading event caused by environmental factors in residential buildings. Hospitals treating SARS cases were at high risk for transmission. I found that hospital outbreaks triggered community transmission as well as the formation of spatial clusters of community cases. The size of the community outbreak in an area increased with the size of the outbreak in the nearest hospital treating SARS, and an area was more likely to have no community-infected cases if it was far from hospitals treating SARS, or had less hospital-infected cases within the area. To quantify the transmission between hospital and community, I developed a spatial epidemic-tree-reconstruction method that uses gravity models to spatially define the probability of contact between individuals in the community. From the reconstructed probabilistic infection tree, I estimated that 24% of community transmission was likely to be infected by cases infected in hospitals, with infected patients discharged during their incubation period and hospital visitors the most important drivers of transmission from healthcare settings to the community. Healthcare workers were key drivers of hospital transmission, with the hospital-to-hospital reproduction number, excluding a single hospital super-spreading event, estimated to be 0.8. A typical community-acquired case was estimated to generate 0.6 cases in the community and 0.2 cases in the hospital in which they were subsequently hospitalised. My findings suggest that hospital infection control could be improved. Restricted hospital visitor policies could have been imposed for longer time during the outbreak and quarantine could be considered for those who recently visited or have been discharged from hospitals treating SARS cases

Characteristics of biofilm formation from mixed microflora at mesophilic and thermophilic fermentative hydrogen production / Lam Wai Fung

Biofilm-based systems have been extensively used as immobilized cell systems as they enhance the reaction rates and population dynamics. Therefore, this study was done to characterize the biofilm formation from anaerobic sludge for fermentative hydrogen (H2) production at mesophilic and thermophilic conditions. This study has been focusing on the development of mixed microflora biofilms whereby the physical and chemical characteristics of the biofilm will be studied. Several tests were done to characterize the biofilm formation, which included the Fourier transform infrared spectroscopy (FTIR) to test the functional group present in the immobilized cell, analysis on the gas produced by the immobilised cells using a gas analyser, and lastly analysis on the chemical compositions presence in the extracellular polymeric substances (EPS) of biofilm. This study had identified that the highest amount of gas collected which representing hydrogen is 470 ppm with the condition of 60 °C with GAC. From the FTIR analysis, the functional group exist in two peak 3308.3cm-1 and 1637.12cm-1 are the hydroxyl (O-H) group and the combination of C–N + N–H groups in proteins respectively. The transmission of each peak from the FTIR result, and the concentration of the carbohydrate and protein in the extracted EPS had increased with the increasing of the fermentation day, indicates that the physical and chemical properties of the EPS may change more than expected during biofilm growth and alteration

Immunopanning purification and long-term culture of human retinal ganglion cells

Purpose: To establish a robust method to isolate primary retinal ganglion cells (RGCs) from human fetal retina for long-term culture while maintaining neuronal morphology and marker protein expression. Methods: A total of six human retinas were obtained from aborted fetuses at 10 to 12 weeks of gestation with informed consent from mothers. RGCs were isolated and purified by a modified two-step immunopanning procedure. The cells were maintained in a serum-free defined medium supplemented with brain-derived neurotrophic factor, ciliary neutrophic factor, and forskolin. The viable RGCs and the extent of neurite outgrowth were examined by calcein-acetoxymethylester assay. Expression of RGC markers was studied by immunocytochemistry. Results: Primary RGCs from human fetal retinas were isolated and maintained in vitro for one month with substantial neurite elongation. In cell culture, almost 70% of the isolated cells attached, spread, and displayed numerous dendrites. They were immunoreactive to RGC-specific markers (Thy-1, TUJ-1, and Brn3a) and negative for glial fibrillary acidic protein and amacrine cells marker HPC-1. Conclusions: Human RGCs were successfully isolated and maintained in long-term culture. This can serve as an ideal model for biologic, toxicological, and genomic assays of human RGCs in vitr

Cross-disciplinary collaboration through WuZhiQiao Project to foster cultural exchange and community engagement

In 2013, students of the Technological and Higher Education Institute of Hong Kong (THEi), with the support of WuZhiQiao (WZQ) Charitable Foundation, formed a core team of 11 students to organize and participate in social service projects to help the underprivileged in the Chinese mainland. WuZhiQiao (WZQ) projects, the first cross-region social service engagement by THEi students, bring together students from Hong Kong and the Mainland. WZQ Charitable Foundation aims to help the Chinese traditional village in building Pedestrian Bridge and organizing community projects. Since there are Chinese villages facing flooding during rainy seasons, the local villagers will be trapped inside the village without the chance to go outside or wade outside the village. There are hundreds of such villages and they highly need our help. Each project mainly involves two or three institutes from Hong Kong and the Mainland, and they organize the whole volunteer project including planning, investigation, design, promotion and operation. Through involvement in different states or provinces, WZQ projects provide good chance of communication and interaction between Hong Kong teams and the Mainland teams and advocate intercultural social services. The projects can foster the cultural exchange between Hong Kong and the Mainland. Moreover, the majority of WZQ project members are coming from the fields of engineering, architecture and health care. We can practice our learning from lectures through the project implementation. Different parties are involved in the engineering projects including clients, consultants, contractors, surveyors, engineers and workers. Engineering students can gain good understanding of the holistic picture of a real-life engineering project. We visited the location village for investigation to learn more about the local culture, geometry and the people’s needs and discussed with the Mainland Team through online chatting tools in order to propose the optimal pedestrian building design and other community projects. Having spent over six months in planning and preparation, THEi students will implement a bridge-building and community project in Chongqing in January 2015. Through engagement in this service-learning project, not only the undergraduates of THEi can benefit through personal development but the life quality of the disadvantaged can also be improved

Goal Question Metric as an Interdisciplinary Tool for Assessing Mobile Learning Application

Assessing the mobile learning application among interdisciplinary researchers is a non-trivial task. Mandarin Learning App is a Mandarin 3D game tailor-made for students who choose PBC1033 Mandarin Language Level 1 as an elective course. It is an interdisciplinary project which it involves researchers from software engineering, computational science/mathematics and the Faculty of Language studies. In the project, the software engineer focuses on producing a quality application mostly through usability studies; the language teacher focuses on students’ study performance upon using the Mandarin Learning App and the mathematician focuses on finding the statistical data dependency of collected data through the various statistical packages. Hence, we are facing issues like how to reach a consensus in working on assessing the Mandarin 3D games? How to enable the discussion among the researchers; how to consolidate the results so that we can understand? We introduce Goal Question Metric to tackle these issues. In this paper, we demonstrate how Goal Question Metric is used to form a holistic view of assessing requirements on mobile applications and guide the discussion and reach consensus in analyzing the results of the evaluation. The contribution of this paper is to introduce Goal Question Metric as an interdisciplinary tool while assessing the mobile learning application. With Goal Question Metric, we demonstrate how it can structure the assessment from a different viewpoint in a comprehensive and systematic manner; 1) better structure of the experiments, 2) able to reach consensus among researchers from different disciplines, 3) able to analyze the dependencies among various experiments and 4) able to find hidden results

Oil palm waste: An abundant and promising feedstock for microwave pyrolysis conversion into good quality biochar with potential multi-applications

Oil palm waste (OPW), comprising mainly of empty fruit bunch, mesocarp fiber, frond, trunk, and palm kernel shell generated from palm oil industry, was collected, characterized, and then pyrolyzed to evaluate their potential to be converted into biochar with desirable properties for use in multi-applications. The OPW was detected to have considerable amounts of carbon (43–51 wt%) and fixed carbon (30–39 wt%), showing potential to be converted into carbon-rich biochar. Microwave pyrolysis of palm kernel shell as the selected OPW produced a biochar with zero sulphur content and high heating value (23–26 MJ/kg) that is nearly comparable to conventional coal, thus indicating its potential as an eco-friendly solid fuel. The biochar obtained was also showed low moisture (<3 wt%) and ash (3 wt%), and a highly porous structure with high BET surface area (210 m2/g), indicating the presence of many adsorption sites and thus showing desirable characteristics for potential use as pollutant adsorbent in wastewater treatment, or bio-fertilizer to absorb nutrient and promote plant growth. Our results demonstrate that OPW is a biowaste that shows exceptional promise to be transformed into high-grade biochar rather than simply disposed by landfilling or burned as low-grade fuel in boiler

Age-Specific Associations of Usual Blood Pressure Variability With Cardiovascular Disease and Mortality: 10-Year Diabetes Mellitus Cohort Study.

Background The detrimental effects of increased variability in systolic blood pressure (SBP) on cardiovascular disease (CVD) and mortality risk in patients with diabetes mellitus remains unclear. This study evaluated age-specific association of usual SBP visit-to-visit variability with CVD and mortality in patients with type 2 diabetes mellitus. Methods and Results A retrospective cohort study investigated 155 982 patients with diabetes mellitus aged 45 to 84 years without CVD at baseline (2008-2010). Usual SBP variability was estimated using SBP SD obtained from a mixed-effects model. Age-specific associations (45-54, 55-64, 65-74, 75-84 years) between usual SBP variability, CVD, and mortality risk were assessed by Cox regression adjusted for patient characteristics. After a median follow-up of 9.7 years, 49 816 events (including 34 039 CVD events and 29 211 mortalities) were identified. Elevated SBP variability was independently, positively, and log-linearly associated with higher CVD and mortality risk among all age groups, with no evidence of any threshold effects. The excess CVD and mortality risk per 5 mm Hg increase in SBP variability within the 45 to 54 age group is >3 times higher than the 70 to 79 age group (hazard ratio, 1.66; 95% CI, 1.49-1.85 versus hazard ratio, 1.19; 95% CI, 1.15-1.23). The significant associations remained consistent among all subgroups. Patients with younger age had a higher association of SBP variability with event outcomes. Conclusions The findings suggest that SBP visit-to-visit variability was strongly associated with CVD and mortality with no evidence of a threshold effect in a population with diabetes mellitus. As well as controlling overall blood pressure levels, SBP visit-to-visit variability should be monitored and evaluated in routine practice, in particular for younger patients

AC and AG Dinucleotide Repeats in the PAX6 P1 Promoter are Associated with High Myopia

Purpose: The PAX6 gene, located at the reported myopia locus MYP7 on chromosome 11p13, was postulated to be associated with myopia development. This study investigated the association of PAX6 with high myopia in 379 high myopia patients and 349 controls. Methods: High myopia patients had refractive errors of –6.00 diopters or greater and axial length longer than 26 mm. Control subjects had refractive errors less than –1.00 diopter and axial length shorter than 24 mm. The P1 promoter, all coding sequences, and adjacent splice-site regions of the PAX6 gene were screened in all study subjects by polymerase chain reaction and direct sequencing. PAX6 P1 promoter-luciferase constructs with variable AC and AG repeat lengths were prepared and transfected into human ARPE-19 cells prior to assaying for their transcriptional activities. Results: No sequence alterations in the coding or splicing regions showed an association with high myopia. Two dinucleotide repeats, (AC)m and (AG)n, in the P1 promoter region were found to be highly polymorphic and significantly associated with high myopia. Higher repeat numbers were observed in high myopia patients for both (AC)m (empirical p = 0.013) and (AG)n (empirical p = 0.012) dinucleotide polymorphisms, with a 1.327-fold increased risk associated with the (AG)n repeat (empirical p = 0.016; 95% confidence interval: 1.059–1.663). Luciferase-reporter analysis showed elevated transcription activity with increasing individual (AC)m and (AG)n and combined (AC)m(AG)n repeat lengths. Conclusions: Our results revealed an association between high myopia and AC and AG dinucleotide repeat lengths in the PAX6 P1 promoter, indicating the involvement of PAX6 in the pathogenesis of high myopia

Isolation and characterization of a human heart cDNA encoding a new member of the small heat shock protein family — HSPL27

AbstractA novel cDNA clone was isolated from a human adult heart cDNA library. This cDNA clone is similar to the small heat shock protein (smhsp) in both DNA and amino acid sequences, especially in the conserved region. Sequence analysis has shown that the putative novel smhsp, named 27 kDa heat-shock-protein-like protein (HSPL27) is a protein of 241 amino acids with a deduced molecular mass of 26.7 kDa and a deduced pI of 8.0. We have expressed the HSPL27 in E. coli and the expressed protein was found to be present in the soluble fraction of the bacterial cell lysate. Chromosomal mapping data shows that the HSPL27 gene is located at human chromosome 5q11.2