• 수산해양교육연구
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• 제25권6호
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• pp.1285-1293
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• 2013

This study was conducted to investigate the effects of dietary inclusion of various additives Solid sulfur, fucoidan, and glucan on growth performance and immune responses in Juvenile olive flounder paralichthys olivaceus. Six experimental diets supplemented with : no additives (CON); 0.5 and 1.0% solid sulfur (S); 0.2 and 0.4% fucoidan (F); 0.1% glucan (G) of these additives diet on a dry-matter basis. Fish averaging $8.2{\pm}0.17g$ were fed one of six experimental diets in triplicate groups for 6 weeks. By the end of the feeding trial, weight gain, feed efficiency, specific growth rate, protein efficiency ratio, hepatosomatic index and condition factor of fish fed diet CON were significantly lower then those of fish fed the all additives diets (P < 0.05). In challenge test, fish were infected by intraperitonel injection of 0.1 ml bacterial suspension with Edwardsiella tarda per fish after the feeding trial. As a result fish fed All additive diet showed a lower cumulative mortality then did fish fed CON diet throughout the challenge test. In conclusion, these results indicated that solid sulfur, fucoidan and glucan enhanced the growth, feed efficiency and non-specific immune activity of juvenile flounder and protect the fish against microbial infections.

• 한국수산과학회지
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• 제46권3호
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• pp.310-314
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• 2013

This study investigated the utilization of beef tallow and dextrin as non-protein energy sources in the diet of juvenile far eastern catfish Silurus asotus. Three replicated groups of juveniles (initial mean weight of 3.6 g) were fed diets containing high levels of beef tallow or dextrin for six weeks. The final mean weight of fish fed on a 17% lipid diet with a high level of beef tallow was significantly higher than that of fish fed on a 9% lipid diet with a high level of dextrin (P=0.04). No significant differences were observed in the feed efficiency and protein efficiency ratio of fish fed on the experimental diets. Crude lipid content and the C18:0, C18:1n-9 and C18:2n-6 contents of whole-body fish were significantly affected by diet (P<0.05). The results of this study suggest that beef tallow is better than dextrin as a non-protein energy source for improving the growth of juvenile far eastern catfish, and that beef tallow could be economically used as an ingredient in practical feed.

• 한국발생생물학회지:발생과생식
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• 제21권4호
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• pp.399-406
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• 2017

This study was conducted to investigate egg development and larvae morphological development of catfish and to provide basic data to clarify the genetic relationship with Siluriformes fish. The mother fish that was used in this study was caught in the stream of Nakdong River in Uiseong-gun, Gyeongbuk. The temperature range of the breeding was $23.0-25.0^{\circ}C$ (mean $24.0{\pm}1.0^{\circ}C$) and egg size was 1.62-1.70 mm (mean $1.66{\pm}0.05$, n=30). Eggs of catfish began hatching at 54 hours and 40 minutes after fertilization. Immediately after hatching, the total length of larvae was 3.60-3.65 mm (mean $3.62{\pm}0.03$, n=5) and had an egg yolk without swimming ability. On the third day after hatching, the larvae at the medium stage was 8.00-8.65 mm (mean $8.32{\pm}0.45$) in total length, and two pairs of whiskers formed around the mouth were elongated. On the 12th day after hatching, the larvae at the juvenile stage was 16.5-17.0 mm (mean $16.7{\pm}0.35$) in total length, and the stem of each fin was in the range, and the juvenile at this period was morphologically similar to the mother fish.

• 한국발생생물학회지:발생과생식
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• 제23권2호
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• pp.171-181
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• 2019

To produce healthy and stable seed production, we need to obtain information and understand vision that affects behavior of red spotted grouper. We examined their expression and retinal development during the juvenile development. Short-wavelength sensitive opsin (SWS2), a cone photoreceptor, began to be expressed from lens and ear vesicle formation stage and its expression increased until 10 days after hatching (dah). In case of middle-wavelength sensitive opsin (MWS), its expression was detected at 3 dah and reached the highest level at 21 dah. The expression of long-wavelength sensitive opsin (LWS) was first observed from 3 dah and their expression decreased thereafter. Rhodopsin, a rod photoreceptor, was found to be expressed from 2 dah and its expression reached the highest level at 50 dah. The outer nuclear layer (ONL), inner nuclear layer (INL) and ganglion cell layer began to differentiate at 2 dah, while choroid first appeared at 4 dah so that the eyes became black. These results indicate that the development of retina mostly completes around 4 dah. It seems that the development of the retina and the expression of the opsin genes are closely related to the behavior such as hunting prey, considering that the timing of the completion of the development of the retina, the timing of gene expression, and the timing of completion of yolk absorption are similar.

• 수산해양교육연구
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• 제27권5호
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• pp.1229-1235
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• 2015

Juvenile banded catfish(Pseudobagurus fulvidraco, mean length $10.7{\pm}0.42cm$ and mean weight $15.0{\pm}0.23g$) were exposed to varies TAN(total ammonia) concentrations at pH levels of $6.12{\pm}0.51$, $7.00{\pm}0.26$ and $8.04{\pm}0.07$ for 96hrs to check the level of acute toxicity on biofloc technology aquaculture system(BFT). The result showed that cumulative mortalities for juvenile banded catfish at TAN levels 48.95, 55.96, 66.47, and 78.88 mg/L at pH $6.12{\pm}0.51$ were 0, 30, 30, and 50%, respectively. At pH $7.00{\pm}0.26$, its mortalities to TAN 5.20, 11.68, 15.31, and 18.31 mg/L were 0, 10, 20, and 70%, respectively and at pH $8.04{\pm}0.07$, the mortalities to TAN 0.96, 1.49, 2.13, and 3.62 mg/L were 10, 20, 40, and 100%, respectively. Its $96h-LC_{50}$ (median lethal concentration, $LC_{50}$) at pH $6.12{\pm}0.51$, $7.00{\pm}0.26$, and $8.04{\pm}0.07$ were 78.12, 15.87, and 2.21 mg/L for TAN, and 0.05, 0.10, and 0.14 mg/L for $NH_3$, respectively, and the acute toxicity for ammonia to juvenile banded catfish increased exponentially with increase of pH.

• Fisheries and Aquatic Sciences
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• 제17권4호
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• pp.391-401
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• 2014

Ten feeding trials were conducted to determine and to make the guideline for the optimum feeding rates in olive flounder Paralichthys olivaceus fed extruded pellets at various growth stages at the optimum rearing water temperature. The entire trials were grouped into four growth stages, namely the first stage of juvenile (5 and 9 g), the second stage of juvenile (20, 30, 40 and 50 g), growing (240 and 317 g) and sub-adult (384 and 525 g) stages with 2, 4, 2 and 2 feeding trials, respectively. In the first and second experiments, results indicated that the optimum feeding rates for the first stage of juvenile olive flounder weighing 5 and 9 g could be >5.17 but <5.52% and >4.44 but <4.64% body weight (BW)/day, respectively. In the third, fourth, fifth and sixth experiments, results suggested that the optimum feeding rates for the second stage of juvenile olive flounder weighing 20, 30, 40 and 50 g could be >3.47 but <3.50, >2.85 but <3.53, >2.58 but <3.04 and >2.36 but <2.50% BW/day, respectively. In the seventh and eighth experiments, results showed the optimum feeding rates for growing olive flounder weighing 240 and 317 g to be >1.03 but <1.25 and >0.85 but <1.0 % BW/day, respectively. In the ninth and tenth experiments, the optimum feeding rates in sub-adult olive flounder weighing 384 and 525 g were shown to be >0.69 but <0.7 and >0.55 but <0.8% BW/day, respectively. We will compare these results with the previous studies done by other research groups.

• 한국수산과학회지
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• 제49권5호
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• pp.635-641
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• 2016

The feeding habits of juvenile and young Seriola quinqueradiata, which were collected by a hand net and set net in coastal waters of the South Sea during the period from June to August 2014 and 2015, were analyzed. The size range of juveniles was 4.9-10.9 cm FL, and that of young S. quinqueradiata was 11.0-20.4 cm FL. Important prey items in the diets of juveniles were euphausiacea and copepoda, dominated by the Euphausia sp., Paracalanus sp. and Calanus sinicus while the diets of the young consisted mainly of pisces, dominated by Engraulis japonicus, Trachurus japonicus. Stomach content compositions differed significantly among body size levels in both the juveniles and young (ANOSIM, P<0.05). With increasing size, the mN/ST constantly decreased while the mW/ST constantly increased (one-way ANOVA). Graphical analysis of the diet composition showed that juvenile S. quinqueradiata are generalized feeders, young is a specialized feeders characterized by strong individual feeding specialization.

• 한국응용곤충학회지
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• 제30권4호
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• pp.258-264
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• 1991

본연구는 오리나무잎벌레(Agelastica coerulea Baly)성충의 유면 유기에 미치는 온도와 광주기 영향 및 유약호르몬(juvenile hormome III)과 탈피호르몬(20-hydroxyecdysone)이 휴면중인 성충에 미치는 영향을 조사하기 위하여 수행되었다. 오리나무잎벌레는 일년에 일회 발생하며 난, 유충, 용 성충기간은 가각 7~10일, 19~21일, 14~15일, 약 10개월로 조사되었다. 오리나무잎벌레의 알과 유충을 $25^{\circ}C$와 $20^{\circ}C$의 조건에서 광주기를 각각 16L/8L, 12L/12D, 8L/16D로 달？여 사육하여도 모든 성충이 휴면에 들어가 이들은 필수성충휴면을 하는 것으로 생각되었다. 휴면기간동안 난소는 거의 발육되지 않았으며 유면말기의 개체를 $25^{\circ}C$, 16L/8D에 노출시키면, 난소소관이 급속하게 발달되었다. 휴면중인 성충에 유약호르몬을 처리하면 일시적으로 휴면이 타파되고 산란이 이루어졌으나 탈피호르몬은 아무런 영향도 미치지 못했다.

• 사물인터넷융복합논문지
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• 제7권4호
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• pp.59-68
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• 2021

본 연구는 소년원생들의 재비행 방지와 사회적응을 효과적으로 향상시키기 위하여 인성교육 차문화치료 프로그램을 개발하고자 한다. 사회적 개입을 통한 차문화치료 프로그램의 효과성을 검증하기 위하여 프로그램에 참여하기 전과 후 소년원생들의 자기효능감, 자기통제력, 대인관계 등의 사회적 특성 점수에 유의미한 차이가 나타났는지 분석하였다. B시 소재 소년원에서 수용생활을 하는 14세에서 17세 사이 소년원생들 10명을 연구대상의 실험집단으로 선정하였다. 소년원생 사회적 개입 인성교육을 위한 차문화치료 프로그램을 10회기 진행하였고, 그 결과 자기효능감은 사전 평균 2.37(SD 0.33), 사후 평균 2.49(SD 0.31)로 나타나 유의미한 차이를 보였으며(Z=-5.874, P=.000), 자기통제력은 사전 평균 2.06(SD 0.20), 사후 평균 2.16(SD 0.19)으로 나타나 유의미한 차이를 보였다(Z=-4.743, P=.001). 대인관계는 사전 평균 1.90(SD 0.32), 사후 평균 2.15(SD 0.21)로 나타나 유의미한 차이가 나는 것으로 확인되었다(Z=-5.892, P=.000). 이상의 결과들은 본 프로그램이 소년원생들의 자기효능감, 자기통제력, 대인관계 등의 사회적 특성 향상에 유의미한 효과가 있음을 보여주고 있다. 따라서 본 연구에서 개발된 소년원생 인성교육을 위한 차문화치료 프로그램은 향후 교정복지 현장뿐 아니라 다양한 유형의 청소년들을 위한 인성교육 프로그램으로 활용될 수 있을 것이다.

• 한국응용곤충학회지
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• 제61권1호
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• pp.101-108
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• 2022

곤충생장조절제(IGR)은 대상 해충에 대한 특이성이 높고 환경에 대한 독성이 상대적으로 낮다는 장점으로 유기합성 살충제를 효과적으로 대체할 수 있는 유망한 수단으로 여겨진다. 현재 시판되는 곤충생장조절제는 작용 기작에 따라 유충호르몬 작용제(JHA), 탈피호르몬 작용제(EA) 및 키틴 합성 저해제(CSI)의 세 가지로 구분된다. 최근 들어, 이집트숲모기의 Met과 FISC/CYC 유전자를 yeast two-hybrid system에 도입하여 유충호르몬에 의해 매개되는 Met과 FISC/CYC의 결합을 in vitro에서 구현하였으며, yeast two-hybrid β-galactosidase assay를 통하여 식물과 미생물 및 화합물 library로부터 다양한 유충호르몬 길항제(JHAN)가 분리되고 있다. 유충호르몬은 곤충의 발달, 생식, 휴면 등을 포함한 다양한 생리 작용을 조절하기 때문에, 유충호르몬 길항제는 대상 해충의 내분비 신호 전달을 방해하여 비정상적인 발달 및 유충 단계에서의 치사를 초래하며, 이는 유충호르몬 길항제가 넓은 기주 범위를 가진 살충제 개발에 효과적으로 이용될 수 있다는 것을 시사하였다. 따라서 본 논문에서는 유충호르몬 길항제의 작용점인 Met에 의해 매개되는 유충호르몬의 신호 전달 체계와 친환경 살충제로서의 유충호르몬 길항제의 전망에 대해 알아보고자 하였다.