• 한국식물학회:학술대회논문집
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• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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• pp.191-211
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• 1987

Common usage of the concept of juvenility implies that there is one physiological phase, the juvenile phase, which manifests itself in the various morphological and physiological phenomena observed in juvenile higher plants. The juvenile phase is often defined as that time from seed germination until the plant attains the ability to flower regulating such behaviour. This definition precludes plants from flowering in the juvenile phase. It is of major interest, therefore, to identify the physiological controls(Bluehreife) regulating such behavior. The length of the juvenile period in higher plants ranges from one year to over 60 years in different species. The long juvenile period of seedling is the main cause of the long duration of the breeding process. I determined the length of the juvenile period in various plants and its control of phase changes in natural system in relation to factors such as plant size and age, shoot morphology, apex size, root system and phytohormonal and nutritional status is reviewed. From the own experimental and observational evidence available it appears that both hormonal and nutritional factors can be involved in control of juvenility but that a specific juvenile or flowering hormone is not involved. Grafting, ringing, scoring, root pruning and fertilization have been used to accelerate flowering, but in most cases these cultured treatments are only successful on plants that were passed the juvenile phase. It is suggested that there are intrinsic difference between the meristematic cells of the apieces of juvenile and adult shoot, which are thus determined with respect to there development potentialities. The problems associated with the maintenance of the determined state through mitosis are discussed. The properties of transitional forms of Ribes nigrum L. intermediate between the juvenile and adult phase, are descrived and there implications discussed. Analogies are drawn between juvenile phenomena in woody perennials and in herbaceous species.

• 생태와환경
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• 제34권4호통권96호
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• pp.310-318
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• 2001

낙동강에서 치어섭식이 동물플랑크톤에 미치는 영향을 채집된 치어의 소화관조사를 통해 고찰하였다. 조사지역인 낙동강 하류 물금에서는 유량이 감소하고 수체가 정체되는 5월에서 6월사이 5종류의 치어가 높은 밀도를 나타내었다 같은 시기, 동물플랑크톤 군집내에서는 대형윤충류인 Asplanchna spp.와 Brachionus spp., 지각류인 Moina micrura 및 Bosminopsis deitersi의 밀도가 큰 폭으로 감소하였다. 반면, Polyarthra속의 소형윤충류는 최대 밀도를 나타내었다. 채집된 치어의소화관 조사 결과, 15 mm이하의 치어는 대형윤충류 및 지각류를, 15mm 이상의 치어인 경우 지각류를 선택적으로 섭식하는 것으로 나타났다. 큰입배스의 치어의 경우, 같은 시기 채집된 치어에 비해 대형이었으며 동물플랑크톤 뿐 아니라 다른 치어를 포식하는 것으로 조사되었다. 조사 결과, 이시기의 낙동강 동물플랑크톤 군집내의 대형 윤충류와 지각류의 급격한 밀도 감소는 치어의 섭식으로 인한 것으로 사료된다. 반면, 이러한 밀도감소는 치어의 수가 감소함에 따라 회복되는 경향을 보였다. 부영양화된 낙동강의 경우 배스치어의 섭식으로 인한 치어밀도의 급속한 감소, 풍부한 먹이농도 등이 감소한 지각류의 밀도회복을 유도하는 것으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제17권4호
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• pp.441-448
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• 2014

We examined the effects of dietary nutrient content, feeding period, and feed allowance on compensatory growth, food use, chemical composition, and serum chemistry of juvenile olive flounder Paralichthys olivaceus. We placed 720 juvenile fish into 24 400-L flow-through round tanks (30 fish per tank).A $2{\time}2{\time}2$ factorial design (diet: control (C) and high protein and lipid (HPL) ${\time}$ feeding period: 8 and 6 weeks ${\time}$ feed allowance: 100% and 90% of satiation) was applied. Fish were hand-fed twice daily, based on the designated feeding schedule. Weight gain and food consumption were affected by both the feeding period and feed allowance, but not by diet. The food efficiency ratio was not affected by diet, feeding period, or feed allowance, but the protein efficiency ratio and protein retention were affected by diet and feeding period, respectively. We found that the full compensatory growth of fish was not achieved at a restricted feeding allowance.

• Fisheries and Aquatic Sciences
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• 제18권3호
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• pp.325-332
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• 2015

An active stimulating method for juvenile fishes to drive escaping from mesh of the codend was examined by shaking canvas in the bottom trawl followed by shrimp beam trawl. Field fishing trials by a bottom trawl were carried out between the Geomoondo and Jejudo in west of South sea, Korea by conver-net methods to examine the effect on the reduction of juvenile fish as a discard catch by generating a shaking movement of the codend using two pieces of asymmetrical semi-circular canvas. The mean period of the shaking motion with the round canvas was 10-15 s, and the range of amplitude as a vertical depth change was up to 0.4-0.6 m when towing speed 3.4-4.3 k't as estimated by peak event analysis. The escape rate of juvenile fish in conver-net by total juvenile bycatch (codend and cover-net) in 14 trials increased from 20% in a steady codend to 34% using a shaking codend in the bottom trawl, while the marketing catch or total bycatch was similar between steady and shaking cod ends. There was no difference in the body size of the fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction actually up to 18% using an active stimulating device, although further experiments are needed to increase an effective shaking motion of the codend in amplitude and period for more bycatch reduction.

• 대한가정학회지
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• 제31권3호
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• pp.143-155
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• 1993

In recent years, behavioral disorders of young people and juvenile delinquency tend to increase remarkably in number, and closed up highly as a social and educational problems in Korea. It goes without saying that parents generally play important roles in children's development of personality, and the home is mostly responsible for juvenile delinquency. Therefore, first this paper describes a relation between broken family and juvenile delinquents. Burt, Shideler, Neumayer, and Glueck maintain that broken family is a cause of delinquency, on the other hand, Healy and Sutherland assume a critical attitude toward their contentions. Second, Breckinridge, Merril, and Glueck maintain that poor family is as cause of delinquency, while Sullenger, Neumayer, and Dirksen make a considerable point which poverty has no direct connection with delinquency. Third, abnormal family relationships namely, discord family, abnormal parent-child relationship, and immoral family exert a bad influence upon formation of personality, esepecialy during the period of preschool childhood. These results give some empirical support to the theory that children's conduct disorders and juvenile delinquency are caused by defective family relationships. It is necessary that a community has a supporting structure of children's wholesome development and the prevention of juvenile delinquency.

• 한국콘텐츠학회논문지
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• 제20권11호
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• pp.323-332
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• 2020

소년이 보호받아야 하는 이유는 다양하지만, 그중에서도 가장 핵심적인 이유는 소년범죄자들이 성인범죄와는 달리 그들의 개선 가능성에 있다고 할 수 있다. 현행 소년법은 다음과 같은 점에서 개선할 부분이 있다고 생각한다. 첫째, 형사처분과 보호처분으로 구분되는 과정상의 명백하고 객관적인 근거가 없다. 둘째, 소년을 두텁게 보호하고자 하는 입법정신은 이해할 수 있으나 실제 소년범죄에 대한 소년법의 적용과정을 검토해 보면, 이러한 정신은 발견하기가 어려워 보인다. 셋째, 소년보호사건을 처리함에 있어 처분결과 뿐만 아니라 처분과정에 대하여도 소년의 보호와 복지적 관점이 반영되어야 할 것이다. 마지막으로, 사건의 처리기간 단축을 비롯해 강력범의 소년원 송치 지양 그리고 제1호 처분의 후단과 제6호 처분의 통합 문제에 대해서는 좀 더 적극적인 개선의 노력을 해야 할 것이다.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.

• Animal cells and systems
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• 제7권4호
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• pp.345-348
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• 2003

The effects of acute acid stress on hatching success and hatching period of laboratory-reared hermaphroditic fish Rivulus marmoratus were examined. The effects of acute acid toxicity on mortality was also determined in three life stages of this fish. There was a significant negative effect of acid stress on hatching performance in the R. marmoratus embryos. The hatching success was only 5% at pH 3.5 compared to over 78% at pH higher than 4.0. The hatching period was also delayed by low pH treatments. The larval and juvenile stages were more sensitive to acid toxicity on mortality than the adult stage, but larvae and juveniles showed similar sensitivity. The 96-h LC50 value was pH 3.8 in larval and juvenile stages and pH 3.3 in adult stage.

• 한국컴퓨터정보학회논문지
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• 제25권8호
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• pp.151-157
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• 2020

소년 범죄를 예방 하는 방안으로는 범죄자를 처벌하는 방안을 우선 고려할 수 있다. 그러나 범죄자 처벌이 능사는 아니다. 더구나 판단력이 부족한 특성이 있는 소년기의 특성을 고려하면 처벌 위주 보다는 개선 교육을 제공함으로써 당사자로 하여금 범죄자에게 사회가 가하는 낙인을 피할 수 있게 할 수 있으며 사회 복귀를 통해서 사회적 기술도 터득할 수 있을 뿐만 아니라 사회 발전에 기여할 수 있는 직업 능력을 계발할 수 있는 기회를 상실하지 않을 수 있을 것이다. 소년범죄예방을 위한 해외사례를 종합해보면 미국의 종합전략프로그램 중 배치 매트릭스를 통해서 소년의 요보호성 정도와 위험 노출 정도를 종합적으로 평가하고 범죄 경력의 진행을 고려하여 그에 상응하는 제재를 가하고 그 제재의 정도를 세분화해서 적용하고 있다. 청소년 범죄 예방의 주체로는 사법기관의 독자적인 업무로 보기보다는 가정·학교·지역사회·사법기관 공동으로 청소년 범죄 예방의 주체가 되어야 할 것이다.

• 한국수산과학회지
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• 제54권4호
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• pp.426-433
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• 2021

This study aimed to determine the appropriate salinity condition for optimal cultivation of the juvenile hybrid grouper Epinephleus akaara♀×E. lanceolatus♂ in conditions of decreasing salinity. The survival, growth, metabolic rate, stress, and histological response were investigated in juvenile hybrid grouper exposed to different salinities for 30 days. At 0 psu, the survival rate of the juvenile hybrid grouper was 60% on the 2nd day of exposure and all individuals died on the 3rd day of exposure. At salinities above 3 psu, all animals survived throughout the exposure period. Growth rate for body weight of the juvenile hybrid grouper was the highest in the control and the lowest at 10 psu. Plasma osmolality of the juvenile hybrid grouper exposed to different salinities was 313-355 mg Osmol/kg at salinities above 10 psu, and then decreased to 225-264 mg Osmol/kg at salinities below 5 psu. The oxygen consumption rate tended to decrease as the salinity decreased. Stress responses of the juvenile hybrid grouper were analyzed with decreasing salinity. Therefore, it is considered that a salinity of more than 20 psu is suitable for the culture of the juvenile hybrid grouper.