• Title/Summary/Keyword: Jeju culture

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Spawning Behavior, Egg and Larvae Developments of Maroon Clownfish, Premnas biaculeatus (Maroon Clownfish, Premnas biaculeatus의 산란습성과 난 발생 및 자치어의 외부형태발달)

  • Kim, Jong-Su;Choi, Young-Ung;Rho, Sum;Yoon, Young-Seock;Jung, Min-Min;Song, Young-Bo;Lee, Chi-Hoon;Lee, Young-Don
    • Journal of Aquaculture
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    • v.20 no.2
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    • pp.96-105
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    • 2007
  • A pair of maroon clownfishes with an indonesian native, reared in recirculation culture system to develope its aquaculture techniques. Courtship, spawning behavior, egg developments and rearing of the maroon clownfish larvae were documented. The larval development were described with illustrative figures. The spawning was occurred 8 times between Feburary and August 2004. The gravid female spawned during 15:00-20:00. The male mainly took care of the eggs supplying oxygen by water currents using their pectoral fins, anal fin and mouth. The fertilized eggs were separative-adhesive and oval in shape, and $1.99{\pm}0.03\;mm$ in longer diameter and $0.88{\pm}0.03\;mm$ in shorter diameter. The fertilized eggs were in deep-orange color. Cleavage occurred in 30 minutes after fertilization, and the egg reached 2 cells stage in 1 hour 10 minutes after fertilization at $27.0^{\circ}{\pm}0.5^{\circ}C$. The embryo was formed in 23 hours 40 minutes after fertilization. Hatching began in between $120{\pm}2$ hours and $150{\pm}12$ hours after fertilization at $27.0^{\circ}C$ in the incubator. Total length (TL) of the newly hatched larvae was 3.22 mm with mouth and anus opened. Ten days after hatching, mean TL of the larvae were 6.21 mm with 28 dorsal fin rays, 17 anal fin rays and 28 caudal fin rays. Nineteen days after hatching, mean TL of the larvae were 9.34 mm. At this stage the larva had three white bands on the body, and they began to feed on commercial diet.

Effects of Apex Removal on the Growth and Yield of Artichoke by Planting Times (정식시기별 생장점 제거가 아티초크(Cynara scolymus L.)의 생육 및 수량에 미치는 영향)

  • Seong, Ki-Cheol;Kim, Chun Hwan;Son, Danial;Lim, Chan Gyu;Cheon, Sung Jong
    • Journal of Bio-Environment Control
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    • v.23 no.1
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    • pp.56-59
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    • 2014
  • Apex removal is a common practice in artichoke cultivation to harvest heads of lateral shoots. This experiment was carried out to investigate the effect of apex removal by different planting times on the growth and yield of Artichoke (Cynara scolymus L.) in open field. Two treatments (apex removal and no apex removal) at three different planting times ($1^{st}$: Sep. 27, 2011, $2^{nd}$: March 29, 2012, and $3^{rd}$: Sep. 21, 2012) were tested using 'Green Globe' variety. There was no difference in the head characteristics and the number of harvested head between the treatments. The head weight was heavier in no apex removal of 242.7 g than the apex removal of 170.8 g. The yield also increased in no apex removal by 25% (1,249 kg/10a) compared to the apex removal of 997 kg/10a at the first planting time. At the second planting time, there was no difference in the head weights between the treatments. But the number of the harvested head was higher in no apex removal with 10.8 than 8.2 of the apex removal. The yield of no apex removal was 2,660 kg/10a, which was higher than 1,848 kg/10a of apex removal. At the third planting time, the head weight increased in no apex removal with 253.5 g compared to the apex removal with 218.7 g. The yield of no apex removal was 1,405 kg/10a, which was higher than 1,148 kg/10a of the apex removal. All the tests at 3 different planting times showed that the artichoke yields were higher in no apex removal than in apex removal. Therefore, it is desirable to cultivate artichoke without removing the apex for the higher yield and labor saving in open-field cultivation in Jeju island.

Characteristics of $Malassezia$ $pachydermatis$ Isolated from Dogs and Antifungal Effect of Essential Oils (개에서 분리된 $Malassezia$ $pachydermatis$의 특성과 Essential Oil의 항진균 효과)

  • Kim, Joo-Yeon;Olivry, Thierry;Son, Won-Geun
    • Journal of Veterinary Clinics
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    • v.29 no.2
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    • pp.141-147
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    • 2012
  • This work describes the characteristics of $Malassezia$ $pachydermatis$ isolated from dog ear canals and the effect of essential oils on the growth of this organism. Sterile cotton swabs were used to collect specimens from the external ear canal and culture tests were performed to detect the population size of $Malassezia$ yeast. Using three different isolation media, included Sabouraud dextrose agar (SDA) to isolate common $M.$ $pachydermatis$, and SDA supplemented with olive oil (SDAO) and Leeming's medium (LM) to detect lipophilic yeast, $Malassezia$ spp were isolated from 14 of 18 dogs (77.8%); isolation rates were 33.3% in SDA, 72.2% in SDAO and 66.7% in LM media. All $Malassezia$ spp isolates were identified as $M.$ $pachydermatis$ according to results of PCR amplification, but gross colony morphology and SDA growth rates suggested four different subtypes. Large (LC) and medium colony (MC) types respectively describe large colony (diameter > 3 mm) and medium colony (around 2 mm) after 72 hour incubation, and small (SC) type refers to smaller colony (< 1 mm) even after 5 days incubation; lipid dependent colonies did not grow onto SDA. Large Colony type strains were isolated from 4, 11, and 11 samples, MC type strains from 2, 3 and 1 and SC type strains from 1, 2 and 1 in SDA, SDAO and LM, respectively. Lipid-dependent $M.$ $pachydermatis$ (Lipo) were isolated from 3 samples each in SDAO and LM. Anti-$M.$ $pachydermatis$ activity testing was done using disc-diffusion assays and well diffusion tests. Most essential oils inhibited the growth of $M.$ $pachydermatis$ in a range from 0.5% to 1.0% of essential oils. MIC90 and MIC50 were variable depending upon the nature of essential oils. Thyme oil was found to be highly effective in inhibiting the growth of $M.$ $pachydermatis$ in a range from 0.125% to 0.0625% while marjoram and then tea tree oil exhibited lower inhibitory capacity.

Effect of an Offshore Fish Culture System on the Benthic Polychaete Community (외해가두리 양식이 저서다모류군집에 미치는 영향)

  • Jung, Rae-Hong;Yoon, Sang-Pil;Kim, Youn-Jung;Lee, Won-Chan;Hong, Sok Jin;Park, Sung-Eun;Oh, Hyung Taik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.4
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    • pp.195-205
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    • 2013
  • Excessive input of organic matters from fish cage farming has been considered as one of the major factors disturbing benthic ecosystem, especially in semi-enclosed coastal waters. Recently offshore aquaculture in the vicinity of Jeju-do has been introduced to minimize that kind of negative impact. This study was conducted to investigate the ecological impacts of offshore aquaculture on the macrobenthic polychaete communities. A total of ten sampling works were carried out for 28 months, spanning from 10 days after starting giving feed to 3 months after stopping giving feed. During the study period, mean current velocity was quite strong with the range of 50 cm/s to 70 cm/s. TOC of surface sediment was constantly low. Significant changes in polychaete community were detected just three months after starting giving feed, which were the increase of the number of species and density at all stations. Up to 18 months after the start of farming, the amount of feed provided played an important role in the fluctuation of the number of species and density, especially at 0 m and 10 m stations. After reducing the amount of feed provided, dominance of some opportunistic species within 10 m distance from fish cages still lasted to the end of aquaculture. However, opportunistic species disappeared 3 months after the end of farming, which indicated the sign of recovery from the disturbance. From these results, the amount of food input and the period of cultivation were critical factors disturbing polychaete community and ensuing changes in this offshore and oligotrophic waters as well. In addition, study on the changes of polychaete community structure before and after fish farming showed more detailed changes in benthic ecological state than geochemical approach did.

Literature Review and Analysis on Research Trends of Sociology in the Journal of Korean Gerontological Society (한국노년학의 사회학 분야 연구동향)

  • Kim, Ju-Hyun;Yeom, Jihye;Kim, Tae-il
    • 한국노년학
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    • v.38 no.3
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    • pp.745-766
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    • 2018
  • The purpose of this study is to examine the research trends regarding the published articles in the Journal of Korean Gerongological Society within the past 10 years. This study is based on the article written by Won and Mo (2008). This article classified previously published studies into themes, methods, and application of theory. Out of the total of 187 articles published in the past 10 years, 11 articles were about social change and institution, 94 articles were about social issues, 12 articles were about social problems and deviation, 42 articles were about social culture, 14 papers were about gerontological theory and 13 papers were about residence/architecture. In the last 10 years, the most popular topic was around the various ways aging. New topic that emerged was the effect of IT and technology on the quality of life among the older adults. Other topics that gained interest were age discrimination and prejudice on aging. Trends in research methods showed increased use of qualitative methods. In the future, more research needs to be completed to theorize the results of quantitative research. Furthermore, the use of qualitative research methods needs to be increased in order to understand the lives of older adults in depth. Through more meta analysis, the results of past research articles should be synthesized to get a bigger picture of the Korean older adults.

The Growth of Ginseng Industry and the Activities of Ginseng Cultivators in the 1930s: Focusing on Non-Government-Contract Cultivation Areas (1930년대 인삼업의 성장과 삼포민의 활동 -특별경작구역 이외 지역을 중심으로-)

  • Jeongpil Yang
    • Journal of Ginseng Culture
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    • v.5
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    • pp.52-76
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    • 2023
  • This article focuses on changes in the ginseng industry in the 1930s in areas other than the Government Contract Cultivation (GCC) zones. A major characteristic of the ginseng industry in the 1930s was the rapid increase in the area covered by ginseng gardens: the area was about 212 ha in 1929 and 252 ha in 1930 and 1931 but soared to around 441 ha in 1938. This occurred because the non-GCC areas increased significantly during this period. Until the early 1930s, the ratio of GCC to non-GCC areas was 70:30. By the late 1930s, however, the ratio had changed to 53:47. The reason for this change was that the area of the newly established ginseng gardens in the GCC zones had decreased, while that of the non-GCC ginseng gardens had steadily increased. Due to the Japanese invasion of China, China boycotted red ginseng, and exports were sluggish, so the GCC areas were reduced. On the other hand, the non-GCC ginseng gardens were not affected, and the area they covered steadily increased. As a result, in the 1930s, the ginseng industry outside of the GCC areas grew rapidly. The region that led the growth of the ginseng industry outside of the GCC zone was Jeonbuk. By the late 1930s, Jeonbuk dominated the other provinces and accounted for more than 50% of the non-GCC farming zone. Gyeongbuk and Gangwon-do followed Jeonbuk in terms of ginseng cultivation areas. While Gyeonggi-do, Gyeongnam, and Chungbuk were also active in ginseng cultivation, Jeonnam and Chungnam were not active. In the 1930s, the growth of the ginseng industry outside of the GCC zones was driven by the efforts of ginseng farmers and the support of local governments. An examination of Yecheon-gun in Gyeongbuk, Ganghwa-gun in Gyeonggi, and Jecheon-gun in Chungcheongbuk-do showed that ginseng farmers organized cooperatives as the ginseng industry steadily developed in these regions, and these cooperatives worked systematically to cultivate and sell ginseng. In the case of Ganghwa-gun, activities were carried out to incorporate the GCC zone. The Deoksan Ginseng Association in Jecheon-gun determined that financing for cultivation was key and requested subsidies from the provincial government. Administrative authorities also supported the activities of the ginseng farmers. The activities of the farmers and the support of the administrative authorities together led to the growth of the ginseng industry during this period.