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Full- and half-Gilbert tessellations with rectangular cells
We investigate the ray-length distributions for two different rectangular versions of Gilbert\u27s tessellation (see Gilbert (1967)). In the full rectangular version, lines extend either horizontally (east- and west-growing rays) or vertically (north- and south-growing rays) from seed points which form a Poisson point process, each ray stopping when another ray is met. In the half rectangular version, east- and south-growing rays do not interact with west and north rays. For the half rectangular tessellation, we compute analytically, via recursion, a series expansion for the ray-length distribution, whilst, for the full rectangular version, we develop an accurate simulation technique, based in part on the stopping-set theory for Poisson processes (see Zuyev (1999)), to accomplish the same. We demonstrate the remarkable fact that plots of the two distributions appear to be identical when the intensity of seeds in the half model is twice that in the full model. In this paper we explore this coincidence, mindful of the fact that, for one model, our results are from a simulation (with inherent sampling error). We go on to develop further analytic theory for the half-Gilbert model using stopping-set ideas once again, with some novel features. Using our theory, we obtain exact expressions for the first and second moments of the ray length in the half-Gilbert model. For all practical purposes, these results can be applied to the full-Gilbert model—as much better approximations than those provided by Mackisack and Miles (1996)
Genoprotective effect of the Chinese herbal decoction xiao jian zhong tang
The Chinese herbal decoction formula Xiao Jian Zhong Tang (XJZT) is one of the classic formulas from the classic traditional Chinese medicine (TCM). Previous studies on XJZT found that it is effective for treating peptic ulcer, irritable bowel syndrome, functional gastroenteritis and similar psychosomatic disorders of the digestive organs. It has also been shown that all the herbs used in XJZT contain antioxidants. In this study, we investigated the in vitro DNA protection effect of the individual herb extracts and the whole formula. Water extract of the herbs and XJZT were used to pre-treat human lymphocytes. The lymphocytes were then exposed to hydrogen peroxide. The in vitro DNA protection effect of the herbs was investigated by comet assay. No DNA protective effect (P \u3c 0.05) was found for individual herb extracts, but XJZT showed protection of human lymphocytic DNA upon oxidative stress (P \u3c 0.05). The in vitro DNA protection effect of XJZT was conferred by the synergistic effect of the herbs, while the individual herbs had no such effect
A phosphorescent rhenium(I) tricarbonyl polypyridine complex appended with a fructose pendant that exhibits photocytotoxicity and enhanced uptake by breast cancer cells
We demonstrated that the cytotoxicity of a phosphorescent rhenium(I) polypyridine complex with a fructose pendant was enhanced upon irradiation and the cellular uptake of the complex was mediated by fructose transporters and inhibited by unmodified fructose but was independent of glucose-specific transporters. This complex has been used to image breast cancer cells, where fructose transporters are overexpressed
Hong Kong industrial history: brief account of the accompanying role played by technical education and training: part two
The microbiological quality of ready-to-eat food in Siu Mei and Lo Mei shops in Hong Kong
The safety of ready-to-eat food is an important issue. Improper handling of ready-to-eat food items may result in foodborne outbreaks. In this study, Chinese barbecued pork (Char Siu in Chinese) was selected as the target ready-to-eat food item for a microbial survey. The aim of this study was to evaluate the microbiological quality of Chinese barbecued pork sold in licensed Siu Mei and Lo Mei shops in Hong Kong. A total of 115 samples were collected from supermarkets or wet markets in the 18 districts. They were tested for aerobic plate counts (APC), Escherichia coli and Staphylococcus aureus counts, and the presence of Salmonella spp. for assessing their safety level. Results showed APC ranging from 1.97 to 6.84 log CFU/g, with a mean of 5.05 log CFU/g; E. coli counts ranging from none detected to 3.10 log CFU/g, with a mean of 1.78 log CFU/g; and S. aureus counts ranging from none detected to 1.42 log CFU/g, with a mean of 0.15 log CFU/g. The mean APC and E. coli counts of samples from supermarkets were found to be significantly lower than those from wet markets (p \u3c 0.05) indicating that supermarkets had better microbiological quality than wet markets. Salmonella spp. were isolated from 39% of the samples analyzed, indicating that cross-contamination was quite a serious problem in Siu Mei and Lo Mei shops in Hong Kong. Based on these results, recommendations such as routine inspections and training of vendors were suggested to improve the microbiological quality of products sold in licensed Siu Mei and Lo Mei shops in Hong Kong so as to minimize risks of foodborne outbreaks
Suppression of diet-induced hypercholesterolaemia by saponins from panax notoginseng in rats
Panax notoginseng saponins (PNS) are major active constituents of P. notoginseng. This study investigated the mechanisms of the hypocholesterolaemic and atheroscleroprotective effects of PNS. It was found that treatment of PNS (30 or 100 mg/kg/day, p.o.) could significantly reduce elevated serum total cholesterol, triacylglycerol, low-density lipoprotein cholesterol and atherogenic index induced by feeding rats with high cholesterol diet for 28 days. High-density lipoprotein cholesterol could also be increased by PNS treatment. Additionally, PNS significantly enhanced the hypercholesterolaemia-induced reduction of superoxide dismutase activity in the liver. In hypercholesterolaemic rats, PNS significantly improved the endothelium-dependent vasodilatation, acetylcholine-induced nitric oxide production and endothelial nitric oxide synthase mRNA expression in a dose-dependent manner. It also significantly reversed the hypercholesterolaemia-induced changes in mRNA expressions of cholesterol 7α-hydroxylase and peroxisome proliferator-activated receptor α but not HMG-CoA reductase. The findings provided evidence for using PNS to prevent the development of hypercholesterolaemia and atherosclerosis. The hypocholesterolaemic activity of PNS is likely to be resulted from inducing the biosynthesis of bile acids from cholesterol and promoting the β-oxidation of fatty acids in the liver. The vasoprotective function of PNS may be brought about by increasing the gene expression of eNOS in endothelial cells, its antioxidative activity, or both
Modeling your college library after a commercial bookstore? the Hong Kong Design Institute Library experience
The Hong Kong Design Institute (HKDI) is a leading design education institute in Hong Kong under the Vocational Training Council (VTC) group. Opened in September 2010, the HKDI Learning Resources Centre is a specialist library for the study of art and design. The mission of the HKDI Library is to support and promote the academic goals of the Institute, i.e., to prepare the students for professional careers; emphasize learning through a creative and interactive environment; meanwhile uphold a positively relaxing, and yet inviting environment that is very much similar to a commercial bookstore. In order to accomplish this, the HKDI Library aims to serve as a user-centered library for creative learning--by providing an important place for both students and faculty to actively engage in study, research, as well as socializing. Through a series of small focus group interviews with both students and faculty staff at the HKDI, the study investigates how influential the library environment could be in fostering students\u27 learning and other social activities under a creative environment