Hong Kong Baptist University

About: Hong Kong Baptist University is a education organization based out in Hong Kong, China. It is known for research contribution in the topics: China & Population. The organization has 7811 authors who have published 18919 publications receiving 555274 citations. The organization is also known as: Hong Kong Baptist College & HKBU.

Arsenic accumulation and speciation in rice are affected by root aeration and variation of genotypes

Abstract: Root aeration, arsenic (As) accumulation, and speciation in rice of 20 different genotypes with regular irrigation of water containing 0.4 mg As l(-1) were investigated. Different genotypes had different root anatomy demonstrated by entire root porosity (ranging from 12.43% to 33.21%), which was significantly correlated with radial oxygen loss (ROL) (R=0.64, P<0.01). Arsenic accumulation differed between genotypes, but there were no significant differences between Indica and Japonica subspecies, as well as paddy and upland rice. Total ROL from entire roots was correlated with metal tolerance (expressed as percentage mean of control straw biomass, R=0.69, P<0.01) among the 20 genotypes; total As concentration (R=-0.67, P<0.01) and inorganic As concentration (R=-0.47, P<0.05) in rice grains of different genotypes were negatively correlated with ROL. There were also significant genotype effects in percentage inorganic As (F=15.8, P<0.001) and percentage cacodylic acid (F=22.1, P<0.001), respectively. Root aeration of different genotypes and variation of genotypes on As accumulation and speciation would be useful for selecting genotypes to grow in areas contaminated by As.

How social influence affects we-intention to use instant messaging: The moderating effect of usage experience

Abstract: With the advent of Web 2.0, the business world is fast changing its way of communicating and collaborating. In this study, we regarded the use of instant messaging in team collaboration as a social behavior and examined the changing roles of social influence processes in the formation of usage we-intention (i.e. social intention). Building on the belief-desire-intention model and the social influence theory, an integrated model was developed and empirically tested using survey data collected from 482 students. The results demonstrated that desire partially mediates the effects of group norm and social identity on we-intention to use. In addition, the effect of group norm is more significant for users with lower usage experience, whereas the effect of social identity is more significant for users with higher usage experience. We believe this study provides several important implications for both research and practice.

Risk Assessment of Human Exposure to Bioaccessible Phthalate Esters via Indoor Dust around the Pearl River Delta

Abstract: There is limited information on the bioaccessible fractions of phthalate esters in indoor dust in order to estimate human exposure. In the present study, workplace dust and settled house dust samples from Hong Kong, Shenzhen, and Guangzhou, the three major cities scattered around the Pearl River Delta (PRD) were collected. Chemical analyses showed that the phthalates in workplace dust ranged from 144 to 1810 μg/g, with dust from shopping malls containing the highest level, and in home dust ranged from 181 to 9240 μg/g. The most abundant phthalate ester found was bis(2-ethylhexyl) phthalate (DEHP) in both workplace dust and home dust, followed by di-n-butyl phthalate (DBP) and di-iso-butyl phthalate (DIBP). Principal Components Analysis (PCA) indicated that indoor dust around PRD showed similar phthalate esters patterns of composition. A significant correlation was observed between total phthalate esters concentrations in home dust and the number of year of house construction (p < 0.05). The oral bioaccessibility of phthalate esters in indoor dust ranged from 10.2% (DEHP) to 32% (DMP). Risk assessment indicated that the dominant exposure routes varied in different phthalate esters exposure profiles and the dermal contact exposure pathway was identified as an important route for indoor DEHP exposure.

Soil water distribution, uniformity and water-use efficiency under alternate furrow irrigation in arid areas

Abstract: Soil water distribution, irrigation water advance and uniformity, yield production and water-use efficiency (WUE) were tested with a new irrigation method for irrigated maize in an arid area with seasonal rainfall of 77.5–88.0 mm for 2 years (1997 and 1998). Irrigation was applied through furrows in three ways: alternate furrow irrigation (AFI), fixed furrow irrigation (FFI) and conventional furrow irrigation (CFI). AFI means that one of the two neighboring furrows was alternately irrigated during consecutive watering. FFI means that irrigation was fixed to one of the two neighboring furrows. CFI was the conventional method where every furrow was irrigated during each watering. Each irrigation method was further divided into three treatments using different irrigation amounts: i.e. 45, 30, and 22.5 mm water for each watering. Results showed that the soil water contents in the two neighboring furrows of AFI remained different until the next irrigation with a higher water content in the previously irrigated furrow. Infiltration in CFI was deeper than that in AFI and FFI. The time of water advance did not differ between AFI, FFI and CFI at all distances monitored, and water advanced at a similar rate in all the treatments. The Christiansen uniformity coefficient of water content in the soil (CUs) was used to evaluate the uniformity of irrigated water distribution and showed no decrease in AFI and FFI, although irrigation water use was smaller than in CFI. Root development was significantly enhanced by AFI treatment. Primary root numbers, total root dry weight and root density were all higher in AFI than in the FFI and CFI treatments. Less irrigation significantly reduced the total root dry weight and plant height in both the FFI and CFI treatments but this was less substantial with AFI treatments. The most surprising result was that AFI maintained high grain yield with up to a 50% reduction in irrigation amount, while the FFI and CFI treatments all showed a substantial decrease of yield with reduced irrigation. As a result, WUE for irrigated water was substantially increased. We conclude that AFI is an effective water-saving irrigation method in arid areas where maize production relies heavily on repeated irrigation.