This experiment was conducted to compare forage production and grass intakes of warm season grasses for grazing horses in Jeju. The experimental field located at 450m altitude(Jeju Horse Training Center of Korea Racing Association) was divided into 3different treatment plots(3replications) without a fence between treatments, and sown by three treatments(bermudagrass, bahiagrass, bermudagrass+bahiagrass mixture). Three castrated adult horse a were kept on pasture from the 1 of October to the end of October without supplementary concentrates. 'Bahiagrass' cultivar showed the highest dry matter (DM) yield with 8,887㎏/㏊ than those in other treatments (bermudagrass 8,699, bermudagrass+bahiagrass mixture 8,385㎏/㏊). The percentage of grass intakes was higher in the treatment of bahiagrass(92%) than those in other treatments(bermudagrass+bahiagrass mixture 89, bermudagrass78%). The results indicate that the warm season grasses of bermudagrass, bahiagrass, bermudagrass+bahiagrass mixture can be used for grazing pasture of horses in the Jeju.

The root zone applications of a systemic insecticide, carbofuran, were evaluated for their impacts on the brown planthopper, Nilaparvata lugens (Stål), and spider populations in the greenhouse and rice paddy fields. In the green house experiments, no BPH nymphs were hatched at root zone treated on 40 to 50 day-old rice, while around 20 to 54 nymphs per pot were emerged in broadcasting and foliar spray treatments. This indicates that the root zone treatment can kill the eggs of BPH effectively. This is the first study ever demonstrated the high egg mortality of BPH due to the root-zone application. In the field experiments, the density of BPH in root zone treated plots were four to six times lower than in broadcasting and foliar spray plots at the 21 days after application. The BPH outbreaks and hopper-burns were observed at all treatments except the root zone treated plot at the 28 days after application. The root-zone application did not impact on the spider population, while foliar spray killed most of all spiders just one day after application. The densities of spider in foliar spray plots were always lower than in root-zone treated and control plots. The results indicated that the root-zone application of carbofuran can control BPH effectively without adverse effects to the spiders inhabited on the paddy field.

Root zone application of several systemic insecticides was tested for control of the brown planthopper, Nilaparvata lugens (Stål), in Vietnam and Korea. In Vietnam, the results indicated that carbofuran showed the highest nymphal mortality in all experiments, followed by imidacloprid and carbosulfan. When the insecticides were applied on 10-day old rice, carbofuran was shown almost 100% N. lugens mortality at six days after treatment and the efficacy was extended to twelve days after application. In Korea, various root-zone application methods were tested with carbofuran and carbosulfan. The results showed that carbofuran was the most active in reducing the egg hatching rates. When root-zone treated on 40-50 day-old rice in a greenhouse, no nymphs were hatched in carbofuran treated pots, while average of 20 nymphs were emerged in carbofuran broadcasting pots. Especially the number of nymphs emerged in carbosulfan foliar spray was 54 nymphs per pot even at the eight day after application, which was higher than in control pots. This is the first study ever demonstrated the high egg mortality of N. lugens on rice due to the root-zone application of insecticides.

Bioaerosols become a more noticed and important problem in indoor air quality (IAQ) control. In this study, we investigated antibacterial effects of silver nano-particles on Escherichia coli, the common Gram negative bacteria and Staphylococcus aureus, the well-mown Gram positive bacteria under aerosol conditions. The bioaerosols containing each bacterial culture were contacted with silver nano-particles sprayed in a closed chamber. Experimental results showed that the silver nano-particles had strong antibacterial activity against E. coli and S. aureus, respectively. As anticipated, high antibacterial activity was found at a high silver concentration and a long the contact time. It was also found that the bactericidal rate decreased with time due to the aggregation of silver nano-particles. Overall, the experimental finding suggested that silver nano-particles could be successfully applied to improve indoor air quality.

Thrombospondins (TSP-1, TSP-2) are secretory extracellular glycoproteins that are involved in a variety of physiological processes such as tumor cell adhesion, invasion, and metastasis. The present study was undertaken to elucidate the involvement of thrombospondins in the adhesion of osteoblast-like cells using the TSP-1 or TSP-2 antisense MG63 and MC3T3-E1 cell lines. For downregulation of TSPs expression, we prepared antisense constructs for TSP-1 and TSP-2 using the pREP4 an episomal mammalian expression vector, which be able to produce the specific antisense oligonucleotides around chromosome. MG63 and MC3T3-E1 osteoblast-like cells were transfected with the antisense constructs and nonliposomal Fugene 6, and then selected under hygromycin B (50 μM/mℓ) treatment for 2 weeks. Western blot analysis revealed that expression of the TSP proteins was downregulated in the antisense cell lines. The cell adhesion assay showed that adhesive properties of TSP-1 and TSP-2 antisense MG63 cells on the polystyrene culture plate were reduced to 17% and 21% of the control cells, respectively, and those of the TSP-1 and TSP-2 antisense MC3T3-E1 cells also decreased to 19% and 27% of control, respectively. Adhesion of TSP-1 and TSP-2 antisense MC3T3-E1 cells on Type I collagen-coated culture plate decreased to 27% and 76%, respectively. These results indicate that TSP-1 and TSP-2 proteins may have an important role in adhesion of osteoblast-like cells to extracellular matrix.