• Journal of the Korean Geosynthetics Society
• /
• v.12 no.1
• /
• pp.21-28
• /
• 2013

This study proposed optimum lime contents for clayey soils consisting of representative clay minerals, Kaolinite and Na-Bentonite, according to optimum lime content method (ASTM C 977-22) by means of ground improvement method of clayey soils. As geotechnical properties, the variations of atterberg limits and unconfined compressive strength were analyzed and Ca-ion and micro-structure along elapsed time were observed for lime-added clayey specimens. The test results show that optimum lime content method provides an appropriate methodology for ground improvement of clayey soils and the variation of $Ca^{2+}$ might be a good index to predict the rate of ground improvement for clayey soils with lime addition.

• Korean journal of applied entomology
• /
• v.22 no.1 s.54
• /
• pp.26-30
• /
• 1983

Soybean mosaic virus (SMV) infection in seeds wits investigated by an immunochemical method Seven soybean cultivars or lines Bughae No.1, KAS 662-7, Chungbugbaeg, Gwanggyo Clark, Bongeui, and Gangrim were tested using hypocotyls of germinated seeds and presence of SMV was detected in six soybean cultivars but Gangrim. The level of SMV infection in the assayed cultivars varied from 2.1 to $12.5\%$. It seemed that seed coat mottling had no correlation with seeds. SMV infection of the seeds since virus has not always been detected from the mot tled seeds SMV has not been detected in the seeds of variety Gwanggyo which showed necrotic symptoms.

• Journal of Apiculture
• /
• v.34 no.1
• /
• pp.15-26
• /
• 2019

Tracheal mite (Acarapis woodi) is an internal parasite that is parasitic on the bronchus of adult bees and sucks fluid from the trachea. Since its first report by Rennie, it has been spread throughout Europe and in some Asian regions, with adjacent Japan and China reported in 2011 and 2012, respectively. Korea detected specific genes of A. woodi in 2015, but only one of 99 samples has been identified and the being of A. woodi has not been confirmed. In this study, we established a specific nested PCR method to confirm for detecting low-copy number of A. woodi-specific gene in bee samples. As a result, A. woodi-specific COI gene was amplified in 15 of 23 samples, and they were judged positive by melting point analysis and sequencing analysis. Although we could not observe the existence of the mites in bees, our results suggest that tracheal mit might exist in nature.

• Journal of Mushroom
• /
• v.5 no.3_4
• /
• pp.98-102
• /
• 2007

Tricholoma gigantium, an edible mushroom, belongs to Tricholomataceae of Tricholoma and is distributed at Jeju-Do in Korea. It is also well-known as the medicinal mushroom in Taiwan. The cultivation method using the compost was developed in Korea in 1995. To develop a mass cultivation method and a superior strain, four strains were collected and tested. To establish the optimal cultivation conditions, various examinations were accomplished. Bag cultivation was more effective than box cultivation and the optimal relative humidity was more than 80%. Although the mycelial growth was tested in the substrate supplemented with different additives, such as rice bran and wheat bran, there's no significant difference between them. It suggested that the environmental conditions were more important than the substrate additives for cultivation.

• Parasites, Hosts and Diseases
• /
• v.30 no.4
• /
• pp.341-348
• /
• 1992

Because no reference on trombiculid mites (Acarina: Trombiculidae) in Cheju Island where tsutsugamushi disease is highly endemic had been available, studies on trombiculid mites in Cheju Island were implemented during the period of August 1991-Apil 1992, and the results obtained are summarized as follows: (1) The species and numbers of the field rodents collected were 143 Apodemus agrarius chejuensis (92.3%), 11 Crocidura lasiura (7. l%) and 1 Micromys minutus (0.6%) From total 12,075 chiggers harvested, 9 species of 4 genera in Trombiculidae were identified. (2) The predominant species through all seasons was 1. setum (43.3%), followed by 1. orientale (27.4%) and 1. scutellare (26.6%). However, in autumn when the most cases of tsutsugamushi disease occur, 1. scutellere was prominently predominant, having 79.8% of the collected chiggers. (3) Among 1,1421. scutellare examined for Rickettsia tsutsugpmushi by means of IFA test, 6 individuals were found positive showing 0.5% of infection rate. This is the first finding that 1. scutellere is the second vector species of tsutsugamushi disease in Korea. (4) Antibody positive rate of A. agrarius chejuensis sera were 31.2% (44/139), and 1 M. minutes serum was also found positive. The seropositive rates by season were not so significantly different. Key words: Tsutsugamushi disease, epidemiology, vector species, Cheju Island, Korea.

• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 1997.06b
• /
• pp.13-14
• /
• 1997

영지의 약리효과는 triterpenoid계의 저분자와 polysaccharide인 고분자로 대별할 수 있다. 저분자 물질은 항염증작용, 항알러지작용, 간암세포 성장 억제작용, 혈압 강하작용, 혈소판 응집저해작용 등이 있으며, 고분자 물질은 혈압강하작용, 정혈작용, 고지혈증 개선작용, 혈당 강하작용, 면역 증강작용 및 항종양작용 등이 있는 것으로 알려졌다. 현재까지의 영지에 관한 연구는 주로 자실체에 대한 연구가 주류를 이루고 있으며 이들의 산지, 환경조건, 채집시기 및 실험자들에 따라 약리 효과 등에 많은 차이가 있다. 이들에 대한 효과가 영지의 대표적 약리효과라고 언급하기엔 부족한 점이 많으므로 약리효과가 우수하고 일관성이 있는 영지 유래 다당류를 얻기 위한 방법으로서는 균사체의 대량배양법 및 분리방법이 확립 되어야만 한다. 본 연구에서는 새로운 항암활성 다당류의 개발을 위해 국내 자생 영지를 채집하여 검색 및 계통적 분류를 행하였으며 분리된 균주의 최적 액체배양 조건, 다당류 분리 조건, 다당류의 물리화학적 특성 및 약리활성 등에 관한 연구를 실시하였다. 그 중 약리활성이 우수한 G- lucidum IY009 균주를 선발 하였다. 구조적 특징과 종양 면역 활성과의 관계 규명을 위해, G- lucidum IY009 배양균사체로부터 다당류를 T-AS, U-AS, M-AS, S 및 H로 분획 하였다. 추출조건에 따른 다당류 GLG의 수율은 열수 추출 분획이 2.98g/l로 가장 높았으며, U-AS및 T-AS에서 각각 2.32g/l, 2.07g/l이었다. GLG의 특성을 조사하기 위하여 수용성과 비수용성으로 분리한 결과 수용성 분획은 비수용성 분획보다 높은 당 함량을 나타냈으며, T-AS는 70.3%의 당과 7.8%의 단백질로 구성 되었다. GLG 대부분의 분획들은 60~93%의 glucose로 구성된 다당류 이었으며, 주로 $\beta$-glucose로 구성된 다당류 이었다. 아미노산은 Asp 및 Glu의 산성 아미노산과 Ala, Leu 등의 함량이 높게 나타났으며, 비알칼리 추출물에서 Ser과 Thr의 함량이 높게 나타났다. 다당류 T-AS는 평균 분자량이 2,000 kD와 12kD에서 주 peak를 나타냈으며, 수용성 분획의 평균 분자량은 12kD이고 비수용성 분획은 36~2,000 kD의 평균 분자량 분포를 갖는 것으로 나타났다. IR과 NMR 분석 결과 890 cm-1에서 흡수 peak를 나타내어 $\beta$-(1,3)0glucan과 $\beta$-(1,6)-glucan의 구조를 갖는 다당류로 확인 되었다. T-AS 분획은 C:H:O:N의 함량비가 38.9:5.7:49.6:1.84%이며, 이 물질의 융점은 163 $^{\circ}C$로 연한 갈색을 나타낸다. 분리된 GLG의 항암활성 기전 규명을 위해, in vivo 항암실험, 항보체 활성능, 항체 생성능, serum protein 분비능, 대식세포의 탐식능과 활성능 및 세포간 물질 분비 등의 상관관계를 조사하였다. 다당류 GLG 분획물들 가운데 항보체의 활성이 높았던 분획은 sarcome 180에 대한 항암 활성이 높게 나타났다. 다당류 T-AS의 보체 활성화 기작은 classical과 alternative complement pathway의 양 경로를 통해 활성화 되었다. T-AS 분획은 mouse내의 특정 혈청단백을 증가시켰으며, 항체 생성능의 증가가 관찰되어 effect T 세포의 활성화가 나타나고 있음을 알 수 있었다. T-AS는 생체내 투여시에 대식세포의 탐식능이 증진되었으며, 대식세포 기능 저해제에 의한 대식세포의 기능 저해 현상이 회복되었다. 이와 같은 결과들로부터, T-AS의 항암 활성은 활성화된 보체 성분 및 당 수용체들이 존재하는 대식세포의 개입을 시사한다.

• Korean journal of applied entomology
• /
• v.56 no.1
• /
• pp.29-39
• /
• 2017

To compare the features of ground-dwelling invertebrates according agroecosystems, we selected paddy fields, dry fields, orchards in the Eastern region of Korea. The surveys were performed by using pit-fall traps twice per year from 2013 to 2015. Total 6,420 individuals of 172 species belonging to 13 orders, 58 families were investigated in the Eastern region, the species of Hymenoptera (38.26%), Orthoptera (16.28%) accounted large portion of the communities. In the geographical observation, invertebrates were caught was 2,983 individuals in Gyeongsangnam-do, the diversity index of Gyeongsangbuk-do community was higher than of the others and abundance and species richness of paddy field were higher than from dry field or orchard. To understand the relation between taxonomic groups and environmental factors, we carried out the canonical correspondence analysis and hierarchical clustering. As a result, Homoptera, Blattaria, Isoptera, and Coleoptera were positively related to soil pH, soil temperature, and moisture contents, and negatively related to the others. Invertebrate community also were patterned dependently by type of ecosystems. This results were shown that distribution of invertebrates is a few influenced the relationship of the space habituated invertebrates and environmental factors.

• Parasites, Hosts and Diseases
• /
• v.36 no.2
• /
• pp.91-98
• /
• 1998

The present study was performed to observe characteristics of the lifE history of Echinoparvphium recunpatum under both natural and laboratory conditions in Korea. A batch of Rcnix aunculnria corecna was collected from Sunamchon, one of the stream of West Naktonggang (River), in Kangso-gu, Pusan during August and September 1992. Out of 106 snails examined by crushing,52 (49.0%) were infected with larval E. recurvaum i.e. rediae, cercariae and metacercariae. Cercariae naturally shed from snails encysted in the snails of same species and loaches, but not in mud-snails. Adult worms were detected from chicks and ducks experimentally infected with metacercariae, but not from rats and mice. The average recovery rate of adults from chicks was 13.1%. Rediae were sac-like, $2.437{\;}{\times}{\;}0.317{\;}mm$ in average size, with a muscular pharynx and a brownish cecum which reached the anterior half of the body. Cercariae consisted of a spindle-shaped body ($0.262{\;}{\times}{\;}0.129{\;}mm$ in average) and a rod-like tail ($0.528{\;}{\times}{\;}0.056{\;}mm$ in average). In the cercarial body, 45 collar spines were observed on the head crown, and double rows of excretory ducts with fine granules were laterally arranged between the pharynnx and the ventral sucker. Metacercariae were spherical, $0.144{\;}{\times}{\;}0.142{\;}mm in average size, with thick hyaline outer and thin elastic inner walls, and many excretory granules. Adults were slender and more attenuated in the anterior end, $0.2760{\;}{\times}{\;}0.550{\;}mm$ in average size, and had 45 collar spines including four end group spines on both ventral corners. From the above results, it was confirmed that R. auriculnna corennc plays a pivotal role in the life cycle of 5. recuwatum as the first and/or second intermediate hosts in Korea.

• Korean Journal of Ecology and Environment
• /
• v.44 no.2
• /
• pp.136-143
• /
• 2011

Early life history of the endangered species Gobiobotia brevibarba was investigated to provide baseline data for biological characteristics and restoration. Adult fish were sampled by spoon net capture at Hongcheon-gun, Gangwon-do, Korea, in April 2010. Eggs were obtained after injection of Ovarprim and were artificially fertilized by the dry method in the laboratory. The mature eggs were slightly adhesive and transparent with greyish and average $1.24{\pm}0.07$ mm in diameter. The hatching of the embryos took place about 120 h after fertilization at a water temperature of $23^{\circ}C$. The newly-hatched larva averaged $5.5{\pm}0.29$ mm in total length. Four days after hatching, they averaged $7.4{\pm}0.26$ mm in total length and their yolk sacs were completely absorbed. From 15 days after hatching, they entered the juvenile stage and reached $9.9{\pm}0.72$ mm in total length. One hundred days after hatching, their band patterns and external form were similar to those of adults, and they averaged $36.0{\pm}3.11$ mm in total length.

• Korean journal of applied entomology
• /
• v.59 no.3
• /
• pp.209-215
• /
• 2020

Debates over the ecological and public health impacts of aerial pesticide sprays are increasing. This is particularly true for controlling Monochamus beetles, which are vector insects of pinewood nematodes. In 2017, adult female orb-web spiders, Trichonephila clavata, were sampled from pine forests in Yangsan-si, Gyeongsangnam-do, Korea, where the aerial pesticide spray, fenitrothion or thiacloprid, was used for several decades. The biological traits of the spiders (body weight, body length, carapace width, and total hind leg length) were compared among treatment sites (no-spray, sprayed three times, and sprayed five times), and differences were observed. The body length, carapace width, and total hind leg length of the spiders in the sprayed areas were significantly shorter than in the no-spray area, but there were no differences between the area sprayed three or five times. These results indicate that repeated exposures to an aerial pesticide spray can alter morphological parameters, which influences population-level fitness. Future studies should monitor the spider long-term responses to pesticides (a direct effect) and prey availability (an indirect effect).