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A floristic survey was conducted in turf-dominated fields on some waste landfills in South Korea, to quantify the degree of plant invasion in those degraded lands. The dominant species, except turf (Zoysia japonica), were Conyza canadensis, Setaria viridis, Digitaria sanguinalis and Aster tripolium. Mean species number declined linearly with distance from the edge of the turf stands. Biomass of each species ranged between 0.1 g and 122.6 g, decreasing linearly with distance from the edge of the stand and declining exponentially with turf coverage. Mean soil moisture storage and organic matter content were 12.59 per cent and 5.81 per cent, respectively. Sum of relative cover, frequency and biomass of all species with environmental variables (distance from the stand edge, turf cover, soil moisture storage, soil organic matter content and the ratio of species number of exotic plants to that of native plants) were ordinated by DCA (detrended correspondence analysis). The first axis of the DCA was positively correlated with distance from the stand edge and turf cover and the second axis of the DCA was negatively correlated with soil organic matter content. Highly and lowly invasive species were indicated from DCA results. From analysis of dispersal type, barochore and anemochore were the most widespread of other dispersal types but it was suggested that anthropochore played an important role in plant invasion in these degraded wastelands. Establishment of an edge transition zone, enhancement of turf cover and reduction in traffic is recommended as management options for turf fields. Copyright © 2002 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objectives: The infant mortality rate is a sensitive and commonly used indicator of the socio-economic status of a population. Generally, studies investigating the relationship between infant mortality and socio-economic status have focused on full-term infants in Western populations. This study examined the effects of education level and employment status on full-term and preterm infant mortality in Korea. Data were collected from the National Birth Registration Database and merged with data from the National Death Certification Database. Study design: Prospective cohort study. Methods: In total, 1,316,184 singleton births registered in Korea's National Birth Registration Database between January 2004 and December 2006 were included in the study. Multivariate logistic regression analysis was performed. Results: Paternal and maternal education levels were inversely related to infant mortality in preterm and full-term infants following multivariate adjusted logistic models. Parental employment status was not associated with infant mortality in full-term infants, but was associated with infant mortality in preterm infants, after adjusting for place of birth, gender, marital status, paternal age, maternal age and parity. Conclusions: Low paternal and maternal education levels were found to be associated with infant mortality in both full-term and preterm infants. Low parental employment status was found to be associated with infant mortality in preterm infants but not in full-term infants. In order to reduce inequalities in infant mortality, public health interventions should focus on providing equal access to education. [ABSTRACT FROM AUTHOR]