• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.221-225
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• 2002

The first laboratory culture of host-parasite system of Prorocentrum minimum- Amoebophrya sp. was established by single cell isolation method. Here, we report the life cycle stages of the parasitic dinoflagellate. Amoebophrya sp. of the red tide dinoflagellate P. minimum as observed by light and epifluorescence microscopy. Infections developed inside the nucleus of P. minimum. The trophont developed to occupy almost all the intracellular space of the host at its late stage. The fully developed trophont finally ruptured through the host cell. “Vermiform stage”, the free-swimming extracellular lift cycle stage is followed by another stage for the sudden release of many individual dinospores. Our laboratory strain of the host-parasite system for P. minimum, a causative species fur the huge red tides in spring and summer in Korean coastal waters, could be a useful living material for the in situ biological control of harmful algal blooms.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.23-28
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• 2022

The conversion of rice-fields to uplands is increased in last 8 years due to the government's policy. To obtain basic informations on plant-parasitic nematodes in converted uplands, we surveyed nematodes associated with crops cultured on the ridge of the rice-fields. The crops mostly cultivated at the ridge of rice-field were soybean (66%), red bean (21%), and perilla (13%). Ten important plant-parasitic nematodes species were identified: Helicotylenchus sp., Heterodera glycines, Meloidogyne arenaria, M. javanica, M. hapla, Paratylenchus projectus, Pratylenchus coffeae, P. neglectus, Rotylenchus incultus, Trichodorus sp. Tylenchorhynchus crassicaudatus, and T. claytoni. Among them, Rotylenchus incultus was the most common plant-parasitic nematode in all three crops. The ridge is a border of rice field, thus plant-parasitic nematodes infested on ridges should be cautioned for future cropping.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.237-243
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• 1983

A biological study was done on primary parasites and hyperparasites of cow-pea aphid, Aphis craccivora Koch, collected from Mt. Gyeryong and Daejeon area during the period from April to September 1983 was. The results of mummification of primary parasites, host selectivity between primary parasites and hyperparasites and ratio of mummification, no. of ar chegonia and longevity of important species were obtained as follows; Eight species of Aphidiidae were identified and listed and four of them, Binodoxys nearactaphidis Mackauer, Lipolexis scutellaris Mackauer, Lysiphlebus salicaphis(Fitch)and Trioxys hokkaidensis Takada found for the first time in Korea. Among the 509 mummies collected in the field, adult Aphidiid and adult hyperparasites were $44.8\%,\;and\;43.8\%$, respectively. Lysiphlebus ambiguus, Lysiphlebus salicaphis, Lysiphlebia japonica and Lipolexis scutellaris were a few of important species attacking cow-pea aphid and the rate of their occurrences were $31.6\%,\;18.8\%,\;16.7\%\;and\;11.4\%$, respectively. All the hyperparasites collected from cow-pea aphid were recorded for the first time in Korea; those were Lygocerus testaceimonus Kieffer, Protaphelinus nikolskajae (Jasnosh), Eucoila sp., Gastranscistrus sp., Ardilea convexa(Walker), Asaphes vulgaris Walker. Among the collected hyperparasites, Eucoila sp., A. vulgaris and A. Convexa were dominant species and their occurence rate was $39.9\%,\;34.1\%\;and\;19.7\%$, respectively. As a results of analysis on parasite-hyperparasite interrelationship in cow-pea aphid, Lipolexis scutellaris was attacked from 3 out of 6 hyperparasites and the others was attacked from almost all the hyperparasites. Lysiphlebus ambiguus was higher than Lysiphlebia japonica in the ability of parasitism. There was no difference between Lysiphlebus ambiguus(272) and Lysiphlebia japonica(279) in number of archegonia, but L. ambiguus$(66.9\%)$ was higher than L. japonica$(43.0\%)$ in the rate of mummification to archegonia. The longevity of Aphidiidae and hyperparasites was investigated by feeding honey. The results showed that hyperparasites had lived 15.8 to 21. 5 days, while Aphiidiidae lived only 2 to 3 days.

• Animal Systematics, Evolution and Diversity
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• v.20 no.2
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• pp.141-154
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• 2004

Six new species of the genus Enalcyonium are described as parasites of octocorals of New Caledonia. They are Enalcyonium lobophyti, E. humesi, E. caledonensis, and E. auriculatum from the alcyonacean Lobophyton schoedei Moser, E. capillatum from the gorgonacean Rumphella antipathes (L.), and E. bullatum from the gorgonacean Siphonogorgia variabilis (Hickson). This is the first record on the species of Enalcyonium from the South Pacific.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.899-903
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• 2003

In this paper, a wide band helical antenna for mobile handset using parasitic element effect has been investigated. To obtain the effect of parasitic element, we utilized the cylindrical conductor which is not feed. As thickness of cylindrical conductor is increasing, second and third resonance frequency become abruptly variable. In case of that 4.5mm diameter parasitic element cylindrical conductor is inserted, normal mode helical antenna obtained bandwidth of around 900 MHz on the limit of R. L., - 5 dB.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.403-406
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• 1991

A 32-year old housewife, living in Seoul, recognized incidentally a painless mass at the left chest wall. During later 3 months, she experienced spontaneous swelling and regression of the mass repeatedly for 4 times. Surgical resection showed a granuloma at anterior serratus muscle containing a nearly matured adult of Fasciola species without vitellaria and uterus. This is the l1th human fascioliasis and the first extra-abdominal infection reported in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.485-490
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• 2010

We propose the equivalent circuit model including all parasitic components in input gate of sense amplifier of DDI DRAM with butting contact structure. We analysed the effect of parasitic schottky diode by using the proposed model in the operation of sense amplifier. The cause of single side fail and the temperature dependence of fail rate in DDI DRAM are due to creation of the parasitic schottky diode in input gate of sense amplifier. The parasitic schottky diode cause the voltage drop in input gate, and result in decreasing noise margin of sense amplifier. therefore single side fail rate increase.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.483-491
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• 2015

This paper describes the design optimization of parasitic elements used for TACAN broadband antenna. We deployed parasitic elements arranged in a circular array to electronically rotate the antenna instead of employing a mechanically rotated antenna to generate the composite radiation pattern of 15 Hz and 135 Hz including bearing information and to meet the harmonic contents specification of MIL-STD-291C. We performed the simulation for optimization of the parasitic elements and fabricated the antenna composed of 16 parasitic elements of 15 Hz and 63 parasitic elements of 135 Hz. With harmonics magnitude reduction by increasing the number of steps using vector composition of the reflectors, the measured result meets the specification of MIL-STD-291C.

• Korean journal of applied entomology
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• v.28 no.1
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• pp.1-3
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• 1989

Parasitylenchus orthotomici sp. n. is described as a nematode parasite of Orthotomicus an¬gulatus in Korea. In a sample of 170 beetles randomly collected from Pinus densiflora S. et. Z, 51. 8% were parasitized by nematodes. The number of nematodes per bark beetle was ranged from 1 to 97. The parasitisms of F, generation were ranged from 43.2% to 52%. There was no positive tendency in nematode parasitism between sun-side and shade-side.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.48-52
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• 1987

The fauna and the distribution of plant parasitic namatodes were investigated by smapling about five hundred grams of soil around roots of mulberry trees from 929 mulberry fields in Korea. Of fourteen genera detected on mulberry fields, Paratylenchus aciculus, P. projectus, P. morius, Helicotylenchus dihystera, Meloidogyne arenaria were found to be parasitic to mulberry. Among them Paratylenchus species were the most abundant in mulberry fields, but Tylenchorhynchus sp., Aphelenchus sp., Helicotylenchus sp., and Meloidogyne sp. were also observed in high frequency. Meloidogyne species were observed in high frequency in Jeonbuk, Gyeonggi and Jeonnam, Helicotylenchus sp., in Gyeongnam and Gyeonggi, Xiphinema sp., in Jeonbuk and Jeonnam, and Paratylenchus sp., in Gyeonggi, Gyeongbuk, Gyeongnam, and Jeonnam. The growth of mulberry was poor as the increase of density of Paratylenchus sp.