http://repository.lib.polyu.edu.hk/jspui Search the Channel search http://repository.lib.polyu.edu.hk/jspui/simple-search http://hdl.handle.net/10397/5806 Title: Linkage and association of myocilin (MYOC) polymorphisms with high myopia in a Chinese population<br/><br/>Authors: Tang, Wing Chun; Yip, Shea-ping; Lo, Ka Kin; Ng, Po Wah; Choi, Pik Shan; Lee, Sau Yin; Yap, Keng-hung Maurice<br/><br/>Abstract: Purpose: To test the association between myocilin gene (MYOC) polymorphisms and high myopia in Hong Kong Chinese by using family-based association study.; Methods: A total of 162 Chinese nuclear families, consisting of 557 members, were recruited from an optometry clinic. Each family had two parents and at least one offspring with high myopia (defined as -6.00D or less for both eyes). All offspring were healthy with no clinical evidence of syndromic disease and other ocular abnormality. Genotyping was performed for two MYOC microsatellites (NGA17 and NGA19) and five tag single nucleotide polymorphisms (SNPs) spreading across the gene. The genotype data were analyzed with Family-Based Association Test (FBAT) software to check linkage and association between the genetic markers and myopia, and with GenAssoc to generate case and pseudocontrol subjects for investigating main effects of genetic markers and calculating the genotype relative risks (GRR).; Results: FBAT analysis showed linkage and association with high myopia for two microsatellites and two SNPs under one to three genetic models after correction for multiple comparisons by false discovery rate. NGA17 at the promoter was significant under an additive model (p=0.0084), while NGA19 at the 3' flanking region showed significant results under both additive (p=0.0172) and dominant (p=0.0053) models. SNP rs2421853 (C>T) exhibited both linkage and association under additive (p=0.0009) and dominant/recessive (p=0.0041) models. SNP rs235858 (T>C) was also significant under additive (p=4.0E-6) and dominant/recessive (p=2.5E-5) models. Both SNPs were downstream of NGA19 at the 3' flanking region. Positive results for these SNPs were novel findings. A stepwise conditional logistic regression analysis of the case-pseudocontrol dataset generated by GenAssoc from the families showed that both SNPs could separately account for the association of NGA17 or NGA19, and that both SNPs contributed separate main effects to high myopia. For rs2421853 and with C/C as the reference genotype, the GRR increased from 1.678 for G/A to 2.738 for A/A (p=9.0E-4, global Wald test). For rs235858 and with G/G as the reference, the GRR increased 2.083 for G/A to 3.931 for A/A (p=2.0E-2, global Wald test). GRR estimates thus suggested an additive model for both SNPs, which was consistent with the finding that, of the three models tested, the additive model gave the lowest p values in FBAT analysis.; Conclusions: Linkage and association was shown between the MYOC polymorphisms and high myopia in our family-based association study. The SNP rs235858 at the 3' flanking region showed the highest degree of confidence for association. http://hdl.handle.net/10397/5805 Title: Lexicogrammar and collocation : a systemic functional exploration<br/><br/>Authors: Matthiessen, Christian<br/><br/>Abstract: In this paper I will explore the relationship between grammatical patterns and lexical collocations. By grammatical patterns I mean both grammatical types (paradigmatic patterns) and grammatical structures (syntagmatic patterns): I am interested both in what grammatical types engender collocational patterns and in what grammatical structural functions the lexical collocates serve. I will interpret collocation as a lexicogrammatical phenomenon - one that is at the same time both lexical and grammatical. I will also suggest that there is a cline between (i) collocations involving particular lexical items and (ii) more general constraints on the co-occurrence of lexicogrammatical types. In the course of the investigation I will suggest how collocational patterns might be explained by reference to semantic motifs.<br/><br/>Description: DOI: 10.4067/S0718-09342009000300003 http://hdl.handle.net/10397/5804 Title: Increasing surface ozone concentrations in the background atmosphere of southern China, 1994-2007<br/><br/>Authors: Wang, Tao; Wei, X. L.; Ding, A. J.; Poon, Steven C. N.; Lam, Ka-se; Li, Yok-sheung; Chan, L. Y.; Anson, Michael<br/><br/>Abstract: Tropospheric ozone is of great importance with regard to air quality, atmospheric chemistry, and climate change. In this paper we report the first continuous record of surface ozone in the background atmosphere of South China. The data were obtained from 1994 to 2007 at a coastal site in Hong Kong, which is strongly influenced by the outflow of Asian continental air during the winter and the inflow of maritime air from the subtropics in the summer. Three methods are used to derive the rate of change in ozone. A linear fit to the 14-year record shows that the ozone concentration increased by 0.58 ppbv/yr, whereas comparing means in years 1994-2000 and 2001-2007 gives an increase of 0.87 ppbv/yr for a 7-year period. The ozone changes in air masses from various source regions are also examined. Using local wind and carbon monoxide (CO) data to filter out local influence, we find that ozone increased by 0.94 ppbv/yr from 1994- 2000 to 2001-2007 in air masses from Eastern China, with similar changes in the other two continent-influenced airmass groups, but no statistically significant change in the marine air. An examination of the nitrogen dioxide (NO₂) column obtained from GOME and SCIAMACHY reveals an increase in atmospheric NO₂ in China's three fastest developing coastal regions, whereas NO₂in other parts of Asia decreased during the same period, and no obvious trend over the main shipping routes in the South China Sea was indicated. Thus the observed increase in background ozone in Hong Kong is most likely due to the increased emissions of NO₂(and possibly volatile organic compounds (VOCs) as well) in the upwind coastal regions of mainland China. The CO data at Hok Tsui showed less definitive changes com-pared to the satellite NO 2 column. The increase in background ozone likely made a strong contribution (81%) to the rate of increase in "total ozone" at an urban site in Hong Kong, suggesting the need to consider distant sources when developing long-term strategies to mitigate local ozone pollution.<br/><br/>Description: DOI: 10.5194/acp-9-6217-2009 http://hdl.handle.net/10397/5803 Title: Tropospheric ozone climatology over Beijing : analysis of aircraft data from the MOZAIC program<br/><br/>Authors: Ding, A. J.; Wang, Tao; Thouret, V.; Cammas, J.-P.; Nédélec, P.<br/><br/>Abstract: Ozone (O₃) profiles recorded over Beijing from 1995 to 2005 by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program were analyzed to provide a first climatology of tropospheric O₃over Beijing and the North China Plains (NCPs), one of the most populated and polluted regions in China. A pooled method was adopted in the data analysis to reduce the influence of irregular sampling frequency. The tropospheric O₃over Beijing shows a seasonal and vertical distribution typical of mid-latitude locations in the Northern Hemisphere, but has higher daytime concentrations in the lower troposphere, when compared to New York City, Tokyo, and Paris at similar latitude. The tropospheric O₃over Beijing exhibits a common summer maximum and a winter minimum, with a broad summer maximum in the middle troposphere and a narrower early summer (June) peak in the lower troposphere. Examination of meteorological and satellite data suggests that the lower tropospheric O₃maximum in June is a result of strong photochemical production, transport of regional pollution, and possibly also more intense burnings of biomass in Central-Eastern China. Trajectory analysis indicates that in summer the regional pollution from the NCPs, maybe mixed with urban plumes from Beijing, played important roles on the high O₃concentrations in the boundary layer, but had limited impact on the O₃concentrations in the middle troposphere. A comparison of the data recorded before and after 2000 reveals that O₃in the lower troposphere over Beijing had a strong positive trend (approximately 2% per year from 1995 to 2005) in contrast to a flat or a decreasing trend over Tokyo, New York City, and Paris, indicating worsening photochemical pollution in Beijing and the NCPs.<br/><br/>Description: DOI: 10.5194/acp-8-1-2008