Relationship between the molecular composition, visible light absorption, and health-related properties of smoldering woodsmoke aerosols

Organic aerosols generated from the smoldering combustion of wood critically impact air quality and health for billions of people worldwide; yet, the links between the chemical components and the optical or biological effects of woodsmoke aerosol (WSA) are still poorly understood. In this work, an untargeted analysis of the molecular composition of smoldering WSA, generated in a controlled environment from nine types of heartwood fuels (African mahogany, birch, cherry, maple, pine, poplar, red oak, redwood, and walnut), identified several hundred compounds using gas chromatography mass spectrometry (GCMS) and nano-electrospray high-resolution mass spectrometry (HRMS) with tandem multistage mass spectrometry (MSn). The effects of WSA on cell toxicity as well as gene expression dependent on the aryl hydrocarbon receptor (AhR) and estrogen receptor (ER) were characterized with cellular assays, and the visible mass absorption coefficients (MACvis) of WSA were measured with ultraviolet-visible spectroscopy. The WSAs studied in this work have significant levels of biological and toxicological activity, with exposure levels in both an outdoor and indoor environment similar to or greater than those of other toxicants. A correlation between the HRMS molecular composition and aerosol properties found that phenolic compounds from the oxidative decomposition of lignin are the main drivers of aerosol effects, while the cellulose decomposition products play a secondary role; e.g., levoglucosan is anticorrelated with multiple effects. Polycyclic aromatic hydrocarbons (PAHs) are not expected to form at the combustion temperature in this work, nor were they observed above the detection limit; thus, biological and optical properties of the smoldering WSA are not attributed to PAHs. Syringyl compounds tend to correlate with cell toxicity, while the more conjugated molecules (including several compounds assigned to dimers) have higher AhR activity and MACvis. The negative correlation between cell toxicity and AhR activity suggests that the toxicity of smoldering WSA to cells is not mediated by the AhR. Both mass-normalized biological outcomes have a statistically significant dependence on the degree of combustion of the wood. In addition, our observations support the fact that the visible light absorption of WSA is at least partially due to charge transfer effects in aerosols, as previously suggested. Finally, MACvis has no correlation with toxicity or receptor signaling, suggesting that key chromophores in this work are not biologically active on the endpoints tested

A simulation-driven performance testing method for Web applications

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Tests of scaling assumptions and construct validity of the Chinese (HK) version of the SF-36 Health Survey

Few health-related quality of life (HRQOL) survey instruments are available to the Chinese, although many have been developed for Western populations. This article describes the testing of the acceptability, conceptual equivalence, scaling assumptions and construct validity of a Chinese (HK [Hong Kong]) version of the MOS SF-36 Health Survey. A Chinese (HK) SF-36 survey form was developed by an iterative translation process. It was administered to 236 Chinese subjects who also rated the understanding, difficulty, relevance, and acceptability of each question. The scores were tested against the original scaling assumptions. The SF-36 profile of our subjects was compared to U.S. results for conceptual equivalence. Most subjects did not have any problem in understanding and answering the SF-36. Item means were generally clustered as hypothesized. All but a few items satisfied all scaling assumptions. The shape of the eight-scale SF-36 profile was similar to that of American patients, suggesting conceptual equivalence. We conclude that the Chinese (HK) version of the SF-36 Health Survey has achieved conceptual equivalence and satisfied the psychometric scaling assumptions well enough to warrant further use and testing, using the standard scoring algorithms.postprin

Hereditary Colorectal Cancer Syndromes in Hong Kong: a Registry's Perspective

Established in 1995, the Hereditary Gastrointestinal Cancer Registry aimed at cancer prevention due to hereditary colorectal cancer syndromes in Hong Kong through early detection, timely treatment, education and ongoing research. This article details the history, structure and work of the Registry. A summary is also provided on the results of various research work conducted by the Registry which facilitates the clinical management of hereditary colorectal cancer syndromes in Hong Kong Chinese families

Detection of known haemophilia B mutations and carrier testing by microarray

The molecular basis of haemophilia B is heterogeneous and many mutations of the Factor IX (FIX) gene have been characterised. Using the allele-specific arrayed primer extension (AS-APEX) technology, we have designed a FIX array to simultaneously analyse 69 mutations found in British, Thai and Chinese patients. This technology overcomes the problem of multiple reverse dot-blot analysis and has a 100% accuracy in the detection of both affected subjects and carriers in families with known mutations. In seven unknown mutations from Thailand, the array could detect the specific mutation in five and in the remainders the normal primer at specific spots failed to extend due to a mutation a few nucleotides upstream, thus allowing their identification. Hence this FIX array can detect 53% of the 2891 mutation entries in the FIX database. Each of the microarray slide can be used for three different test samples and would be useful for carrier testing for common mutations and prenatal diagnosis. It is simpler and more cost effective than genome sequencing and would be particularly useful in laboratories with limited technical capabilities. © 2005 Schattauer GmbH, Stuttgart.published_or_final_versio

Observed Reductions in Schistosoma mansoni Transmission from Large-Scale Administration of Praziquantel in Uganda: A Mathematical Modelling Study

To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA) with praziquantel in Uganda over four years (2003-2006). In doing this we aim to elucidate the benefits of MDA in reducing community transmission.Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764). Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI), i.e., the rate of parasite acquisition by hosts.MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment.This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general

In-lecture learning motivation predicts students’ motivation, intention, and behaviour for after-lecture learning: Examining the trans-contextual model across universities from UK, China, and Pakistan

This paper presents a cross-cultural examination of the trans-contextual model in University education setting. The purpose of the study was to test the effect of students’ perceived autonomy support and in-lecture learning motivation on motivation, intention, and behaviour with respect to after-lecture learning via the mediation of the social cognitive variables: attitude, subjective norm, and perceived behavioural control. University students from UK, China, and Pakistan completed the questionnaires of the study variables. Results revealed that in-lecture perceived autonomy support and autonomous motivation were positively associated with autonomous motivation and intention to engage in after-lecture learning activities via the mediation of the social cognitive variables in all samples. After controlling for the effect of past behaviour, relations between intention and behaviour were only observed in the Chinese sample. In conclusion, the trans-contextual model can be applied to University education, but cultural differences appear to moderate the predictive power of the model, particularly for the intention-behaviour relationship

A genetic locus for adolescent idiopathic scoliosis linked to chromosome 19p13.3

Adolescent idiopathic scoliosis (ALS) is one of the most common orthopedic disorders, affecting up to 4% of schoolchildren worldwide. We studied seven unrelated multiplex families of southern Chinese descent with AIS, consisting of 25 affected members. A genomewide scan with >400 fluorescent microsatellite markers was performed. Multipoint linkage analysis by GENEHUNTER revealed significant linkage of the abnormal phenotype to the distal short arm of chromosome 19, with both a maximum multipoint LOD score and a nonparametric LOD score of 4.93. Two-point linkage analysis by MLINK gave a LOD score of 3.63 (recombination fraction θ [m=f] = 0.00) at D19S216. Further high-density mapping and informative recombinations defined the AIS critical region in the vicinity of D19S216, flanked by D19S894 and D19S1034, spanning 5.2 cM on the sex-averaged genetic map on chromosome 19p13.3.published_or_final_versio

COORDINATIVE PATTERNS BETWEEN CARVING TURN AND SKIDDING TURN DURING ALPINE SKIING

The purpose of this study was to investigate the coordinative patterns between segments and ski using the continuous relative phase (CRP) on anteroposterior and vertical axis during carving and skidding turn. Fourteen alpine ski instructors were participated in this study. Eight inertial measurement units were used to collect segment kinematic data. Each skier was asked to perform ten carving turns and ten skidding turns on the groomed 15° slope, respectively. CRP angles between all segments and ski were significantly increased during carving turn on the vertical axis. On the other hand, CRP angles between all segments and ski were significantly increased during skidding turn on anteroposterior axis. Therefore, skiers should perform the anti-phase movements of the lower spine-ski, pelvis-ski, thigh-ski and shank-ski on the vertical axis during the carving turn and the in-phase movements of the lower spine-ski, pelvis-ski, thigh-ski and shank-ski on the anteroposterior axis during skidding turn