Pyrethroid resistance in cockroach populations has been a public health challenge since the 1950s. The pyrethroid resistance in the German cockroach, Blattella germanica, is primarily attributed to knockdown resistance (kdr) mutations (E434K, C764R, and L993F) in the voltage-sensitive sodium channel gene (vssc). In this study, the pyrethroid resistance state of the German cockroach in the Republic of Korea (ROK) was assessed by analyzing the frequencies of kdr mutations using one-step PCR with total RNA. The results revealed that among the 25 populations examined, 14 populations exhibited the L993F kdr mutation, while no other mutations were detected. Since other cockroach species are also commonly found in human dwellings in ROK, the vssc genes were cloned from four other species, including Blattella nipponica, Periplaneta americana, Periplaneta japonica, and Periplaneta fuliginosa. Based on the genomic DNA (gDNA) sequences obtained from the vssc cloning, primer sets were designed to amplify the vssc fragment spanning the L993F mutation for each species and used to monitor the development of pyrethroid resistance in cockroach populations in the ROK. The study will facilitate the implementation of a nationwide monitoring program to assess cockroach resistance and select suitable alternatives.

The consumption of pre-treated vegetables (including fresh-cut vegetables) has been significantly increased because of their ease of use for cooking. Vegetable cutting machine has been widely utilized for producing fresh-cut vegetables or agricultural products with different sizes; however, its design standard is not specifically established depending on types of agricultural products. Therefore, this study was conducted to determine mechanical properties (compressive and shear force) of targeted agricultural products (radish, carrot, squash, cucumber, shiitake mushroom and sweet potato) for developing multipurpose vegetable cutting machine. According to ASAE standard (s368.3), compressive and shear force of targeted agricultural products were measured by using custom built UTM (universal testing machine). Shape type of samples and speed ranges (5~15 mm/min) of loading rate on bioyield and shear points were varied by targeted agricultural products. The range of averaged bioyield points of targeted agricultural products were between 7.89 and 146.98 N. On the other hands, their averaged shear points were from 22.50 to 53.47 N. Results clearly showed that the bioyield and shear points of targeted agricultural products were thoroughly affected by their components. As accumulating compressive and shear points of agricultural products, it can be technical feasible to establish the design standard and control mechanism of multipurpose vegetable cutting machine.

Density of malaria vector mosquito was monitored at 24 sites in Korea to estimate malaria epidemic from 2004 to 2009. Twenty four locations include six in Gwangwon province and nine in Kyonggi province and nine in Incheon metropolitan city. Mosquitoes collected by public health centers in 24 sites were sent to each RIPHE(Research Institute of Public Health & Environment) then the RIPHE identified the malaria vector mosquitoes. KCDC analysed the results. Number of malaria vector mosquito collected in 2009 shapely decreased over 33 % when compared with number of mosquito collected from 2004 to 2009. In 2009, malaria vector mosquitoes firstly were collected at Injegun on 2nd week of April (6-13, April) and the highest peak of collected mosquito was demonstrated on 3rd week of August. Number of collected mosquito sharply decreased below 10 at 3rd week of september and None of mosquito was collected 2nd week October. Decrease of number of malaria vector mosquito collected in 2009 seem to be related with lowest temperature around midnight and precipitation days per month.

We suggest a possible scenario of an astrophysical black hole with non-vanishing electric charge and magnetic flux. The equilibrium charge on a rotating black hole in a force-free magnetosphere is calculated to be Q ~ BJ with a horizon flux of ~ BM2, which is not large enough to disturb the background Kerr geometry. Being similar to the electric charge of a magnetar, in sign and order of magnitude, both electric charge and magnetic flux are supposed to be continuous onto a black hole.

Background : This study was carried out to survey the effect of IBA (indole-3-butric acid) concentration on root development characteristics in Viburnum dilatatum cuttings. Methods and Results : The cuttings were collected on July 28, 2016 from plants growing in Korea National Arboretum. Cuttings were treated with different IBA concentrations [0 (control), 10, 100, 1000, 2000 ㎎⋅L-¹] for 10 seconds. Rooting parameters (root number, the longest root length, root fresh weight, root dry weight, rooting percentage, and survival rate) were observed at 8 weeks after cuttings. Rooting percentage was 43, 33, 17, 47, and 40 % at 0, 10, 100, 1000, and 2000 ㎎⋅L-¹ of IBA, respectively. Root number (13.4) was highest under 1000 ㎎⋅L-¹ IBA. Root length (9.4 ㎝) and Root weight (fresh and dry) were highest under 1000 ㎎⋅L-¹ IBA. Conclusion : According to the results, 1000 ㎎⋅L-¹ IBA was the best treatment for increasing percentage rooting percentage and other root development characteristics of V. dilatatum cuttings.

Background : Clematis trichotoma is a deciduous climber belonging to the family Ranunculaceae. This study was carried out to survey the effect of shading levels on growth characteristics in Clematis trichotoma seedling. Methods and Results : Seeds were collected from plants growing in the Mt. Kariwang Jeongseon, Gangwon-do in October 2013, and they were sown to 96 cell plug tray filled with Peatmoss (TKS-2) soil at March, 2015. The experiment was performed with four different shading levels (0, 30, 60, 90%) at July, 2015. According to the experiment, plant height was the highest under 90% of shading. It was found that fresh weight and dry weight of clematis trichotoma were the highest under 90% of shading. The leaf number was the highest under 30% of shading. The leaf number decreased as the shading level increased. Root number and length were the highest under 90% of shading. Conclusion : According to the results, Clematis trichotoma seedling showed the highest growth under 90% shading.

Background : Scrophularia koraiensis is a herbaceous perennials belonging to the family Scrophulariaceae. This study was carried out to survey the effect of LED on root develop characteristics in Scrophularia koraiensis seedling. Methods and Results : Seeds were collected from plants growing in the Mt. Kariwang Jeongseon, Gangwon-do in September 2014, and they were sown to 128 cell plug tray filled with Peatmoss (TKS-2) soil at March, 2015. The experiment was performed with three different LED (Blue, Red, Blue + Red) at July, 2015. Morphological characteristics of root (total root length, root projet area, root surface area, root diameter and root volume) were analyzed with WinRHIZO software. Seedling root growth of scrophularia koraiensis was surveyed to be the highest at the Blue + Red LED in all measuring. Total root length was measured high in the order of Blue + Red, Red, Blue LED. Conclusion : According to the results, Scrophularia koraiensis seedling showed the highest root growth in Blue + Red LED.

This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource. As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of CODMn runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.