• Animal cells and systems
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• 제3권3호
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• pp.243-246
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• 1999

A type of symbiosis was previously described from nature in which the gametophytes of Laminariales were endophytic in filamentous red algae. Here we reconstruct this symbiosis for the first time in laboratory culture using zoospores of the kelp, Undaria pinnatifida, and the red alga, Aglaothamnion oosumiense. Zoospores of U. pinnatifida readily attached to A. oosumiense. In 48 h these spores germinated and the initial germ tube penetrated into the host cell wall leaving only an empty zoospore wall outside the host. Within ten days, four to five-celled endophytic gametophytes were present. Zoospores of Laminaria religiosa which were also inoculated into cultures of A. oosumiense rarely attached to the red alga and never became endophytic. Within ten days the free-living gametophytes of L. religiosa on cover slips became fertile and produced young sporophytes. These observations demonstrate the ability of U. pinnatifida to become endophytic, and show differences in host specificity among kelp species.

• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1931-1937
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• 2019

The heterologous expression of the Streptomyces natural product (NP) biosynthetic gene cluster (BGC) has become an attractive strategy for the activation, titer improvement, and refactoring of valuable and cryptic NP BGCs. Previously, a Streptomyces artificial chromosomal vector system, pSBAC, was applied successfully to the precise cloning of large-sized polyketide BGCs, including immunosuppressant tautomycetin and antibiotic pikromycin, which led to stable and comparable production in several heterologous hosts. To further validate the pSBAC system as a generally applicable heterologous expression system, the daptomycin BGC of S. roseosporus was cloned and expressed heterologously in a model Streptomyces cell factory. A 65-kb daptomycin BGC, which belongs to a non-ribosomal polypeptide synthetase (NRPS) family, was cloned precisely into the pSBAC which resulted in 28.9 mg/l of daptomycin and its derivatives in S. coelicolor M511(a daptomycin non-producing heterologous host). These results suggest that a pSBAC-driven heterologous expression strategy is an ideal approach for producing low and inconsistent Streptomyces NRPS-family NPs, such as daptomycin, which are produced low and inconsistent in native host.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.150.2-150
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• 1999

To investigate the weathering soil buffering capacities of the artificial acidic precipitation, the weathering soils and their leachate solutions were sampled from the host rocks(granite;GR, rhyolite;RH, gabbro;GA, basalt;BA, two serpentinite;SE1, SE2 and limestone;LI) and analyzed for pH and chemical properties. 1n the soil pH of the GR and RH ,the acidic rocks, were 5.02 and 5.95, respectively. And the GA and BA, basic rocks, were 6.52 and 7.57. The SE1 and SE2 were 8.90 and 8.89. While the LI was 7.84. These results means the typical soil pH properties by host rocks. After the artificial acidic precipitation input 5OOml, the average changes of soil leachate solutions treated by pH levels(pH 5.0, 4.0 and 3.0), were pH 5.73, 5.00 and 4.40. in GR soil, and pH 6.19, 5.99 and 5.57 in RH. GA were pH 6.31, 6.04 and 5.86, BA were pH 7.05, 6.85 and 6.56 and SE1 were pH 8.31, 8.26 and 7.71. SE2 were pH 8.29, 8.24 and 7.96. LI were pH 7.55, 7.46 and 6.79. The soil leachate pHs from volcanic rocks were higher than those from the plutonic rocks and GR soils showed greater response than other soils. With increasing 100ml input-solution, the soil leachate pHs were mainly decreased. Cation concentrations, CEC, EC and total nitrogen concentrations of RH and BA soils, the volcanic rocks, were higher than those of GR and GA soil, the plutonic rocks. On the contrary, Al concentrations of the GR and GA soils were higher than those of RH and BA soils, partly because of high quartz content in GR and Al content in the biotite and plagioclase in GA.

• 한국응용곤충학회지
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• 제36권2호
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• pp.156-165
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• 1997

다식성 산림해충인 주동무늬차색풍뎅이(Adoretus tenuimaculatus Waterhouse)의 기주식물과 기주선호도를 조사한 결과, 야외조사에서는 25과 66종류의 식물을 가해하는 것으로 밝혀졌고, 먹이공급 실험을 통하여는 5과 14종의 식물을 식해하는 것으로 나타나 문헌상에 있는 32과 136종류의 기주식물을 합하면 주둥무늬차색풍뎅이의 기주식물은 총 42과 186종류가 되었다. 이들 중 새로 밝혀진 기주식물은 19과 50종이었다. 한편, 15과 39종의 식물을 대상으로 기주선호도를 조사한 결과, 가장 많이 유인된 것은 호두나무(Juglans sinensis)였으며, 가장 많이 식해한 식물은 밤나무(Castanea crenata)였다. 유인율과 피해도가 높은 수종들은 밤나무, 아까시나무(Robinia pseudoacasia), 아그배나무(Malus sieboldii), 호두나무, 신갈나무(Quercus mongolica), 갈참나무(Q. aliena)였다. 그러나 고욤나무(Diospyros lotus), 혹호도(Juglans nigra), 들메나무(Fraxinus mandshurica), 물푸레나무(F. rhynchophylla), 파란칸타(Pyracantha angustifolia), 오동나무(Paulownia Coreana), 팽나무(Celtis sinensis)등에는 전혀 유인되지 않았다. 동일 종류의 식물일지라도 지역에 따라 주둥무늬차색풍뎅이가 가해하였던 것과 가해하지 않았던 경우가 있었으며, 피해 정도도 지역과 시기에 따라 차이가 있었다.

• 생명과학회지
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• 제26권6호
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• pp.646-650
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• 2016

본 연구는 염색체 가공기술(chromosome manipulation technique)을 이용하여 다양한 개수의 염색체를 가진 균주들의 세포 성장속도 및 life span을 비교하여 염색체 수의 증가가 세포 생리에 미치는 영향을 조사하였다. 16개의 염색체를 가지는 숙주세포 FY833 균주와 18개의 염색체를 가지는 YKY18 및 YKY18R 균주, 24개의 염색체를 가지는 YKY24 균주와 30개의 염색체를 가지는 YKY30 균주를 사용하여 specific growth rate를 비교해 본 결과, YKY18 균주와 YKY24 균주는 세포성장의 변화가 거의 없었으나, YKY18R 균주와 YKY30 균주에서는 숙주세포에 비해 각각 25%와 40% 이상 성장이 감소됨을 확인 할 수 있었다. 또한 염색체 수와 노화의 관계를 알아보기 위해 replicative life span을 조사해 본 결과, YKY24균주와 YKY30 균주에서 숙주세포에 비해 약 14%와 45% 정도로 life span이 감소했음을 알 수 있었다. 노화인자로 알려져 있는 telomere의 길이도 인공염색체의 수가 증가될수록 점점 다양해지고 길이가 짧아짐을 확인 할 수 있었다. 따라서 염색체 수의 증가도 새로운 노화원인이 될 수 있다는 가능성을 제시하였고, 본 연구 결과가 다양한 인공염색체를 가진 산업용 균주의 안정적인 개량을 위한 기초 자료로 활용될 수 있을 것이라 기대한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.670-675
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• 1994

Yhis paper describes a fault diagnosis simulation of the Real-Time Multiple Fault Dignosis System (RTMFDS) for forcasting faults in a system and deciding current machine state from signal information. Comparing with other diagnosis system for single fault,the system developed deals with multiple fault diagnosis,comprising two main parts. One is a remotesignal generating and transimission terminal and the other is a host system for fault diagnosis. Signal generator generate the random fault signal and the image information, and send this information to host. Host consists of various modules and agents such as Signal Processing Module(SPM) for sinal preprocessing, Performence Monotoring Module(PMM) for subsystem performance monitoring, Trigger Module(TM) for multi-triggering subsystem fault diagnosis, Subsystem Fault Diagnosis Agent(SFDA) for receiving trigger signal, formulating subsystem fault D\ulcornerB and initiating diagnosis, Fault Diagnosis Module(FDM) for simulating component fault with Hierarchical Artificial Neural Network (HANN), numerical models and Hofield network,Result Agent(RA) for receiving simulation result and sending to Treatment solver and Graphic Agent(GA). Each agent represents a separate process in UNIX operating system, information exchange and cooperation between agents was doen by IPC(Inter Process Communication : message queue, semaphore, signal, pipe). Numerical models are used to deseribe structure, function and behavior of total system, subsystems and their components. Hierarchical data structure for diagnosing the fault system is implemented by HANN. Signal generation and transmittion was performed on PC. As a host, SUN workstation with X-Windows(Motif)is used for graphic representation.

• 한국토양환경학회지
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• 제2권1호
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• pp.35-44
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• 1997

토양층과 모암층에서의 산성우에 대한 중화능력을 평가하기 위하여 인공강우를 이용한 컬럼실험을 실시하였으며 토양을 이루고 있는 모암 특성의 차이에 의한 산성강하물의 완충효과를 비교하기 위하여 연구지역내의 모암의 조성광물에 차이가 있는 두 개의 골짜기를 선정하고 골짜기에 흐르는 지표수의 pH를 1996년 5월부터 1996년 10월까지 측정하였다. 컬럼실험에서 사용한 인공강우는 증류수에 황산과 질산을 적절히 첨가하여 pH를 각각 3, 4, 및 5로 조절하였으며 컬럼유출수의 주요 양이온과 음이온을 측정하였다. A층위와 B층위의 양이온 교환용량(CEC)은 각각 9.68 meq/100g과 6.16 meq/100g 이었으며 인공강우의 살포시 컬럼유출수의 pH는 중간층토양에서보다 양이온 교환용량이 큰 표층토양에서 더 크게 나타났다. 컬럼유출수에서의 $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$의 합이 점차로 감소하여 지속적인 산성우는 토양의 양이온 교환용량을 감소시키는 것으로 나타났다. 현장조사결과에 따르면 골짜기의 하류로 내려옴에 따라 지표수의 pH는 계속 증가하여 하류로 흐르는 과정에서의 완충효과를 나타내었다. 이러한 완충효과는 모암의 조성광물중 kaolinite와 illite 이외에도 smectite를 함유하고 있는 골짜기에서 더 크게 나타나는 것이 특징적이었다. 이 결과는 토양충 뿐만 아니라 모암이 산성우의 완충용량을 가지고 있음을 나타내었다.

• 한국식물병리학회지
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• 제14권5호
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• pp.413-417
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• 1998

Magnaporthe grisea, the casual agent of rice blast, requires formation of an appressorium, a dome-shaped and well melanized infection structure, to penetrate its host. Environmental cues that induce appressorium formation include hydrophobicity and hardness of contact surface and chemicals from its host. Artificial surfaces are widely used to induce appressorium formation, but frequencies of appressorium induction are not always consistent. To understand variable induction of appressorium formation in M. grisea, several factors were tested on GelBond. High levels of appressorium formation were induced over a wide range of temperature (20~3$0^{\circ}C$) and pH (4~7). spore age up to 3-week-old did not significantly affect appressorium formation, but only a few apressoria on GelBond. However, adenosine specifically inhibited appressorium formation. Adenosine inhibition of appressorium formation was restored by exogenous addition of cAMP. Germ tube tips of M. grisea maintained the ability to differentiate appressoria by chemical inducers on GelBond at least up to 16 h after conidia germination. These results suggest that environmental factors have little effect on the variable induction of appressorium formation on the artificial surface in M. grisea.

• 한국응용곤충학회지
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• 제42권2호
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• pp.133-138
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• 2003

광대노련재의 계대사육법을 확립하기 위해 $25\pm1^{\circ}C$, 60$\pm$5% R.H., 16L.8D광주기조건 의 실내 사육환경하에서 대체먹이인 생땅콩을 급여하여 사육하면서 발육 특성과 기주 및 산란선 호성을 조사하였다. 광대노련재의 1세대 소요일수는 평균 48일이었다. 알은 유백색의 구형이고 1 난괴당 산란수는 14개가 대부분이었다. 알.약충의 발육기간을 조사한 결과 알기간은 8.2$\pm$0.4일 이었고 각 령별 약충기간은 1령 5.4$\pm$0.2일,2령 8.4$\pm$0.5일, 3령 6.4$\pm$0.4일,4령 7.4$\pm$0.3일,5령 12.6$\pm$0.8일이였다. 성충의 생존일수는 수컷이 평균 30.8일, 암컷은 35.4일 정도였다. 성충화율은 5 57.1%였는데 암수비융은 47: 53으로 수컷의 비율이 약간 높았다. 산란전기간은 평균 22.5일이었 고 펑균산란회수는 4.4회였다. 산란선호성은 기주식물이 있을 경우에는 기주에 산란하지만 기주식 물을 제외시킨 경우에는 아크릴 사육상자, 철망보다는 인조잎에 더 많이 산란하였다. 광대노린재 성충의 기주선호성을 조사한 결과 대상식물 18종 중 황벽나무, 산초나무, 산수유, 충층나무 등의 줄기 및 과실을 가장 잘 흡즙하는 것으로 나타났다.

• 전자공학회논문지S
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• 제35S권4호
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• pp.67-75
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• 1998

In general, Evoluationary Algorithm(EAs) are refered to as methods of population-based optimization. And EAs are considered as very efficient methods of optimal sytem design because they can provice much opportunity for obtaining the global optimal solution. This paper presents a co-evolution scheme of artifical neural networks, which has two different, still cooperatively working, populations, called as a host popuation and a parasite population, respectively. Using the conventional generatic algorithm the host population is evolved in the given environment, and the parastie population composed of schemata is evolved to find useful schema for the host population. the structure of artificial neural network is a diagonal recurrent neural netork which has self-feedback loops only in its hidden nodes. To find optimal neural networks we should take into account the structure of the neural network as well as the adaptive parameters, weight of neurons. So we use the genetic algorithm that searches the structure of the neural network by the co-evolution mechanism, and for the weights learning we adopted the evolutionary stategies. As a results of co-evolution we will find the optimal structure of the neural network in a short time with a small population. The validity and effectiveness of the proposed method are inspected by applying it to the stabilization and position control of the invered-pendulum system. And we will show that the result of co-evolution is better than that of the conventioal genetic algorithm.