• Parasites, Hosts and Diseases
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• 제53권3호
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• pp.315-320
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• 2015

Acarapis mites, including Acarapis woodi, Acarapis externus, and Acarapis dorsalis, are parasites of bees which can cause severe damage to the bee industry by destroying colonies and decreasing honey production. All 3 species are prevalent throughout many countries including UK, USA, Iran, Turkey, China, and Japan. Based on previous reports of Acarapis mites occurring in northeast Asia, including China and Japan, we investigated a survey of Acarapis mite infestations in honey bees in Korean apiaries. A total of 99 colonies of Apis mellifera were sampled from 5 provinces. The head and thorax of 20 bees from each colony were removed for DNA extraction. PCR assays were performed with 3 primer sets, including T, A, and K primers. Results indicated that 42.4% (42/99) of samples were Acarapis-positive by PCR assay which were sequenced to identify species. Each sequence showed 92.6-99.3% homology with reference sequences. Based on the homology, the number of colonies infected with A. dorsalis was 32 which showed the highest infection rate among the 3 species, while the number of colonies infected with A. externus and A. woodi was 9 and 1, respectively. However, none of the Acarapis mites were morphologically detected. This result could be explained that all apiaries in the survey used acaricides against bee mites such as Varroa destructor and Tropilaelaps clareae which also affect against Acarapis mites. Based on this study, it is highly probable that Acarapis mites as well as Varroa and Tropilaelaps could be prevalent in Korean apiaries.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.16-16
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• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• 셀메드
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• 제4권1호
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• pp.4.1-4.4
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• 2014

Gynura segetum, family Asteraceae is a cultivated species and can be found growing in the tropical regions of Indonesia and Malaysia. The plant is known for its use for the treatment of cancer, inflammation, diabetes, hypertension and skin afflictions. In the current study, anti-inflammatory effect of Gynura segetum leaf has been investigated. The present study investigated the in vivo anti-inflammatory effect of Gynura segetum leaf by using hen's egg test-chorioallantoic membrane (HET-CAM) assay. Different solvent extract of Gynura segetum leaf were tested, the most active methanol extract was further fractionated and tested. Among the extracts tested, the methanol extract showed a significant good anti-inflammatory effect (76.8% inhibition at 50 ${\mu}g/disc$) on the HET-CAM assay as compared with the anti-inflammatory drug indomethacin (82.1% inhibition). However, the fractionated sample exhibited a significantly lower activity in comparison to crude methanol extract. The results demonstrated that Gynura segetum leaf displayed remarkable anti-inflammatory effects, which support the folkloric uses of this plant for treatment of inflammation.

• 신재생에너지
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• 제6권3호
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• pp.22-29
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• 2010

The concept of Ocean Thermal Energy Conversion (OTEC) is simple and various types of OTEC have been proposed and tried. However the location of OTEC is limited because OTEC requires $20^{\circ}C$ of temperature difference as a minimum, so most of OTEC plants were constructed and experimented in tropical oceans. To solve this we proposed the modified OTEC which uses condenser discharged thermal energy of existing fossil or nuclear power plants. We call this system CTEC (Condenser Thermal Energy Conversion) as this system directly uses $32^{\circ}C$ partially saturated steam in condenser instead of $20{\sim}25^{\circ}C$ surface sea water as heat source. Increased temperature difference can improve thermal efficiency of Rankine cycle, but CTEC should be located near existing plant condenser and the length of cold water pipe between CTEC and deep cold sea water also increase. So friction loss also increases. Calculated result shows the change of efficiency, pumping power, net power and other parameters of modeled 7.9 MW CTEC at given condition. The calculated efficiency of CTEC is little larger than that of typical OTEC as expected. By proper location and optimization, CTEC could be considered another competitive renewable energy system.

• 식물분류학회지
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• 제46권3호
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• pp.283-287
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• 2016

미얀마 친주에 위치하는 나트마타웅 국립공원에 분포하는 석송류와 양치류의 식물상 목록을 완성하기 위하여 2015년도에 채집을 수행하였으며, 그 결과 4종의 미얀마 미기록 양치류를 발견하였다. 이들은 이웃하는 동남아국가를 비롯한 열대지역에도 동시에 분포하고 있는 것으로 나타났으며 그 목록은 다음과 같다. Adiantum monochlamys (Adiantaceae), Ctenitis decurrentipinnata (Dryopteridaceae), Pteris tripartita 및 Paragymnopteris vestita (Pteridaceae). 이러한 결과는 앞으로 미얀마 양치류의 목록을 새롭게 작성하는 데 이용될 것이다.

• 한국작물학회지
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• 제49권4호
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• pp.316-324
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• 2004

Sinorhizobium sp. strain MUS10 forms nitrogen-fixing stem nodules on Sesbania rostrata, a tropical green manure crop. In this study, the ultrastructural events associated with the formation of stem nodules were investigated. Sinorhizobium sp. strain MUS10 entered the host tissue through cracks created by the emerging adventitious root primordia and multiplied within the intercellular spaces. During early phases of infection, host cells adjacent to invading bacteria revealed cellular damage that is typical of hypersensitive reactions, while the cells at the inner cortex exhibited meristematic activity. Infection threads were numerous in S-day-old nodules and often were associated with the host cell wall. In several cases, more than one infection thread was found in individual cells. The junction at which the host cell walls converged was often enlarged due to fusion of intracellular branches of infection threads resulting in large infection pockets. The infection threads were made up of a homogeneous, amorphous matrix that enclosed the bacteria. Several finger-like projections were seen radiating from these enlarged infection threads and were delineated from the host cytoplasm by the plasma membrane. As in Azorhizobium caulinodans induced root nodules, the release of Sinorhizobia from the infection threads into the plant cells appears to be mediated by 'infection droplets'. A 15-day­old Sesbania stem nodule revealed typical ultrastructure features of a determinate nodule, containing several bacterioids within symbiosomes.

• 셀메드
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• 제2권1호
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• pp.3.1-3.5
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• 2012

Ocimum basilicum belongs to the family Lamiaceae and can be found in tropical Asia, Africa, Central America and South America. It is widely cultivated commercially as a condiment or for the production of essential oil. In this review, this plant is accredited with important effects on health, in addition to being a condiment. In folk medicine it is used to treat vomiting, intestinal colic and diarrhea, menstrual pains and to improve kidney function. Some studies have demonstrated that it can be used for the treatment of hyperlipidemia and also that it has antioxidant, neuroprotective, anti-inflammatory and vasodilator properties as well as hepatoprotective effects. In view of its broad range of effects, further studies should be conducted to ascertain the possible use of this plant in clinical trials, not only for prevention but also as an adjuvant in the treatment of different diseases.

• The Plant Pathology Journal
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• 제30권3호
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• pp.310-315
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• 2014

Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, is responsible for one of the most devastating viral diseases in tomato-growing countries and is becoming a serious problem in many subtropical and tropical countries. The climate in Korea is getting warmer and developing subtropical features in response to global warming. These changes are being accompanied by TYLCV, which is now becoming a large problem in the Korean tomato industry. The most effective way to reduce damage caused by TYLCV is to breed resistant varieties of tomatoes. To accomplish this, it is necessary to establish a simple inoculation technique for the efficient evaluation of resistance to TYLCV. Here, we present the rolling circle amplification (RCA) method, which employs a bacteriophage using phi-29 DNA polymerase for construction of infectious TYLCV clones. The RCA method is simple, does not require sequence information for cloning, and is less expensive and time consuming than conventional PCR based-methods. Furthermore, RCA-based construction of an infectious clone can be very useful to other emerging and unknown geminiviruses in Korea.

• Parasites, Hosts and Diseases
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• 제44권1호
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• pp.67-72
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• 2006

Anthropophilic Culicoides were investigated in a rural community endemic for Mansonella perstans in Ijebu North area of western Nigeria between December 2003 and October 2004. Three hundred and fifty-nine adults of Culicoides fulvithorax collected by human bait in the morning were dissected for Mansonella perstans larvae, and $1.95\%$of infection rate was found. Seasonal abundance of C. fulvithorax was investigated by monthly biting rates, and showed that higher prevalence was observed in rainy season, with peak in September. Culicoides prevalence was positively correlated with rainfall and relative humidity, but not temperature. Human perceptions on the behavior of these biting midges were determined by interviewing 854 self-selected villagers, of which $86.5\%$ of the interviewees confessed having experienced Culicoides bites. Between 76.5 and $99.1\%$ of the various age groups complained body reactions to Culicoides bites. Itching was the most frequent body reaction. No interviewees associated Culicoides with transmission of any parasitic infections. The results showed need to adequately control Culicoides in the community.

• 원예과학기술지
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• 제29권3호
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• pp.260-266
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• 2011

An efficient protocol was established for high frequency somatic embryogenesis through a callus culture of Coelogyne cristata. The best frequency of callusing was obtained from a PLB segment (3-5 mm) cultured on MS medium supplemented with coconut water (CW) and a combination of both 3 $mg{\cdot}L^{-1}$ of 2,4-D and BA. When the calli were sub-cultured on the MS medium without any PGRs, the average number of somatic embryos were higher than those with PGRs treatment. NAA is the most critical factor among PGRs, which dramatically hindered for the formation of a somatic embryo. The efficacy of the addition of coconut powder (CP) for somatic embryogenesis was almost the same in all treatments. However, the number of somatic embryos formed distinctly depended on age of the callus. The somatic embryos converted into healthy plants with well-developed shoots on the same medium. Plantlets showed the best responses of root and shoot growth when transferred to $\frac{1}{2}$ MS medium containing 1.5 $g{\cdot}L^{-1}$ of activated charcoal. All plants with above 3.0-cm-high were successfully acclimatized in the greenhouse.