• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.253-259
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• 1985

This paper presents a natural enemy complex of plant and leafhoppers in rice plants and a relationship between the host insects and their natural enemies. Feeding preference of major paddy spiders have been tested. To date, 32 species of natural enemies of plant and leafhoppers have been recorded, including 30 species of parasites and predators (15 parasitoids, 14 predators and nematode) and 2 species of insect pathogens. Some of species have shown great potential for controlling plant-leafhoppers populations; parasites, Anagrus nr. flaveolus, Gonatocerus sp., Haplogonatopus atratus and paddy spiders. Pirata subpiraticus and Gnathonarium dentatum. Plant and leafhoppers-natural enemy relationship have been observed in different developmental stages of the host insects. Pirata sub-piraticus is the most active to searching the host insects and also prefered nymphs to adults.

• Korean journal of applied entomology
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• v.4
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• pp.51-54
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• 1965

The study was initiated to investigate the nature of varietal resistance to the rice stem borer (Chilo suppressalis WALKER), specially the rotation of the resistance to the silica and nitrogen content of the host Plants. 1. The body freight of the larvae, reared on the stem of the various varieties of rice plants, when weighed at the age of 25 days old, showed great variation, and ranged from 21.24 mgrs. to 45.77 mgrs. depending on the used varieties of tile rice plants. And generally the varieties of Indica types were showed greater body weight than that of Japonica types in this experiments. 2. The positive correlation coefficients of percent survivals to body weight, developement, oviposition preference and rate of damage to host plants were significant, and consequently the percent survival could be used as a criteria of resistance. 3. The content of silica in the host plants was significantly correlated with both the degree of boring on the leaf and attractovemess of larvae, and the total nitrogen content of plants showed significant positive correlation coefficient with larval attractivenes, but not significant with the degree of boring on the leaf. 4. Since the attractiveness and boring manner were significantyly correlated to resistance criteria of rice plant to the pest, it could be considered that the resistance is the results of chain reaction of the factors mentioned above.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.134-138
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• 1999

This study investigated the relationship between attachment site preference of the skin parasite, Entobdella hippoglossi and mucous cell density, moucus cell size and epidermis thickness on the surface of the Atlantic halibut Hippoglossus hippoglossus. Parasites occupying the ventral surface of their host were significantly longer and wider than those found on the other zones of the fish (P<0.05). The mean size of the mucous cells on the front region was significantly greater than the other regions on the dorsal and ventral surface (P<0.05). The average numbers of mucous cells and the epidermal thickness in the skin of the halibut were shown that the front region had significantly higher numbers of mucous cells and thicker layer than the rear region on the dorsal and ventral surface of the halibut, respectively (P<0.05).

• Korean Journal of Veterinary Service
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• v.21 no.4
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• pp.413-429
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• 1998

Escherichia coli is recovered from a wide variety of infections in many animals species. It may be a primary or secondary agent. Nursing and young animals are particularly susceptible, and urinary tract infections are frequent. The various serotypes of E coli are intestinal inhabitants of animals including humans and probably infect most mammals and birds : therefore, they have a cosmopolitan distribution. Colibacillosis refers to any totalized or systemic infection caused entirely or partly by E coli. Collibacillosis in mammals is most often a primary enteric disease, whereas collibacillosis in poultry is typically a secondary located or systemic disease occurring when host defenses have been impaired or overwhelmed. Other opportunistic bacteria, which can be identified by culture, may play a similar role to that of I coli in secondary infections. Collectively, infections caused by E coli are responsible for significant economic losses to the animal performance. From the standpoint of pathogenic mechanisms and diseases, four major categories of E coli are recognized : enterotoxigenic(ETEC), enteropathogenic (EPEC), enteroinvasive(EIEC), and enterohemorrhagic(EHEC). In addition, two less-well-defined E coli categories are recognized in animals and humans : enteroaggregative and cytotoxin necrotizing factor-positive. The aforementioned categories are represented by different serotypes. Certain serotypes show a host preference and are encountered more frequently in some disease syndromes. Of the four major categories, ETEC is the most common cause of diarrhea in calves, lambs, and pigs. Strains in the other categories cause the less-common diarrhea and other disease syndromes. Enterotoxins and pilus antigens are the two most prominent virulence factors thus far identified for ETEC. Two enterotoxins, one heat-stable(ST) and one heat-labile(LT), are produced by enterotoxigenic strains of E coli : not all culture produce both of these plasmid-based enterotoxins.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.346-352
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• 2016

To investigate the oviposition preference and development of azuki bean weevil (Callosobruchus chinensis L.), the following six different leguminous seeds were used in this study: red bean (Vigna angularis (Willd.) Ohwi & Ohashi), black soybean (Glycine max (L.) Merr.), soybean (Glycine max (L.) Merr.), seoritae (Glycine max (L.) Merr.), small black bean (Rhynchosia nulubilis) and kidney bean (Phaseolus vulgaris var. humilis Alef.). In the study of oviposition preference, the numbers of eggs per leguminous seed on red bean, black soybean, soybean, seoritae and small black bean were 1.23, 0.61, 0.69, 1.05 and 1.13, respectively. The maximum daily number of eggs was observed at 48 hours and the minimum was at 96 hours. According to each host leguminous seed, developmental time for each host seed was different. The shortest adult emergence time was on red bean (25.27 days). The other five leguminous seeds increased or doubled the adult emergence time. Adult emergence rates feeding on red bean, seoritae, black soybean, soybean, small black bean were 83.33%, 28.23%, 27.87%, 20.44%, and 11.59%, respectively. Emergence rate on red bean was four times higher than the rate on other seeds. The longevity of emerged female adults was almost all longer than that of males. The male adults weighed the lowest of feeding on small black bean. Female adults weighed the lowest of feeding on soybean. Adult weights were the heaviest for both males and females feeding on red bean. As a result, hosts of azuki bean weevil could decrease oviposition rate, emergence rate, adult longevity, and adult weight but increase emergence time. Especially in kidney bean, adult was not completely emerged. No eggs were laid. These results suggest that there might be emergence inhibitors in kidney bean. These imformation might be used to control damages caused by azuki bean weevils.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.769-775
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• 2005

An efficiency of Monte Carlo (MC) docking simulations was examined for the prediction of chiral discrimination by cyclodextrins. Docking simulations were performed with various computational parameters for the chiral discrimination of a series of 17 enantiomers by $\beta$-cyclodextrin ($\beta$-CD) or by 6-amino-6-deoxy-$\beta$-cyclodextrin (am-$\beta$-CD). A total of 30 sets of enantiomeric complexes were tested to find the optimal simulation parameters for accurate predictions. Rigid-body MC docking simulations gave more accurate predictions than flexible docking simulations. The accuracy was also affected by both the simulation temperature and the kind of force field. The prediction rate of chiral preference was improved by as much as 76.7% when rigid-body MC docking simulations were performed at low-temperatures (100 K) with a sugar22 parameter set in the CHARMM force field. Our approach for MC docking simulations suggested that the conformational rigidity of both the host and guest molecule, due to either the low-temperature or rigid-body docking condition, contributed greatly to the prediction of chiral discrimination.

• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.37-47
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• 2006

Recently, due to the growing concern of the public in rural amenities and hobby farming works, much more urbanites, especially near-retirees, have been interested in rural life style than before. However, in spite of popular preference to ruralities, little has been known about their demand on retired rural life. Therefore, this study examined urbanites' attitude to preparatory works for out-migration, preferred residential site conditions and life style in the countryside. For this purpose, data were collected from a survey with the sample of 386 urban residents aged 40 to 65 rho hoped moving into the countryside after retirement, through structured questionnaires. Descriptive statistical works were performed using SPSS/PC windows program. The major findings of this study were as follows; (1) Host of urbanites, who answered in this study, planned to prepare ex-urban movement in their fifties and to put into practice in their sixties. (2) Key factors of location decision on movement were proximity/accessibility to centre city, medical service level, and distance to their family or friends. And about a half of respondents wanted second home in the countryside. (3) Most favoured rural life styles were nature-friendly well-being and hobby/healthy firming. Generally, the respondents of this survey had the positive attitude to do works in their later life, especially preferred to farming and volunteering in their communities.

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.113-124
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• 1999

This study was carried out to know the oviposition preference site of chestnut brown chafer ( CBC ), Adoretus tenuimaculatus and its temporal activity and spatial distribution in green. Larval distribution was also investigated in golf courses for the control of CBC. CBC collected from Yongwon Golf Club in Chinhae, Tongdo Golf Club in Yangsan, Gyeongsan Province, Daegu Golf Club in Gyeongsan, Kyeongbuk Province, Dongrae Golf Club laid more eggs on broableaf of Zoysia matrella than Z. japonica, broadleaf+middleleaf of Z. matrella, Poa pratensis, and P. annua. The number of CBC egg was $19.7\pm$6.7 in Z. japonica,$ 1.7\pm$1.5 in P. pratensis, $1.3\pm$1.5 in sandy loam and $5.7\pm$2.9 in sand. Acitivity time of CBC in a day was the peak at 20:00 and continued to 24:00. CBCs adults were more collected from outside of golf courses whichhad many host plants than roadside courses. Density of white grubs was significantly different in fairway only. CBCs were more collected at tee and fairway than green. Density of white grubs was $54.6\pm$100 in broadleaf of Z. matellia and $37.7\pm$33.8 in P. pratensis at the back tee of the 7th hole in Dongrae Golf Club.

• Journal of Korean Elementary Science Education
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• v.35 no.1
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• pp.89-97
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• 2016

Science contest is one of the important programs of extracurricular school science activities which give various experience for science learning. In order to understand teachers' perceptions on science contests in elementary school, this study investigated teachers' awareness of science contests, perceptions and difficulties in carrying out science contests in each school, their perceptions on the preparing process of statewide science contest, and the preference of the types of preliminary science contests. 196 teachers were responded to survey, and 8 teachers were interviewed. The results showed that elementary teachers were aware of various science contests through their in-school experiences. The main difficulties of teacher on science contests was lack of professionalism on science and science contests. While teachers preferred the preliminary round of contest by contest's host to the preliminaries of science contest in each school. They also worried about the intimidation of science month's festival in schools. Based on the understanding of the teachers' perceptions on science contests, educational implications were discussed.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.467-477
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• 2009

Host preference was tested on the 7 species plants against ggot-mae-mi, Lycorma delicatula (Hemiptera: Fulgoridae). This insect highly preferred Ailanthus altissima and Vitis vinifera however, didn't choose the other plants preferentially. Both nymphs and adults lived longest in A. altissima and V. vinifera but lived in short and low ecdysis rate against other plants and 3 species fruits. By analyzing the phloem-feeding behavior using EPG, L. delicatula was showed the short time in non-probing phase and it also exhibit the longest feeding time in A. altissima and V. vinifera, but other plants did not feed the phloem at all. In sugar contents analysis, A. altissima existed high sucrose proportion and followed by fructose>glucose, V. vinifera was analyzed by an order of glucose> fructose>maltose>sucrose>rhamnose, Malus pumila was as glucose> fructose, Pyrus calleryana was as glucose>unkown>fructose, Hibiscus syriacus was as sucrose>glucose. Nymphs and adults of L. delicatula lived longest in 5% sucrose solution, and next is in 5% fructose solution. However, they lived short in other sugar solutions. L. delicatula nymph and adult according to the combination of sugar proportion found in original plants lived longer in sugar combination solution of A. altissima and those of V. vinifera was next. Analyzed original sugar proportion from M. pumila, P. calleryana, H. syriacus respectively, L. delicatula lived short period comparing to the A. altissima, V. vinifera. This result was judged that sugar contents affected on choosing the host plants.