• 제목/요약/키워드: Life-cycle stage

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Ultrastructure of Germ Cell during Spermatogenesis and the Reproductive Cycle of the Hanging Cultured Male Scallop Patinopecten yessoensis (Pelecypoda:Pectinidae) on the East Coast of Korea

  • Park, Young-Je;Chung, Ee-Yung;Lee, Jeong-Yong;Park, Kwang-Jae
    • 한국패류학회지
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    • 제22권1호
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    • pp.39-49
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    • 2006
  • Ultrastructure of germ cell differentiation during supermatogenesis and the reproductive cycle in male Patinopecten yessoensis was studied by histological and cytological observations. The gonadosomatic index (GSI) in males rapidly increased and reached a maximum in April when seawater temperature gradually increased. Then the GSI gradually decreased from May through July when spawning occurred. Accordingly, monthly changes in the GSI in males coincided with testicular maturation and spawning periods. The sperm morphology of P. yessoensis belongs to the primitive type and showed general characteristics of external fertilization species. The head of the spermatozoon is approximately $3.50{\mu}m$ in length: the sperm nucleus and acrosome are approximately $2.90{\mu}m\;and\;0.60{\mu}m$ in length, respectively. The nuclear type of the spermatozoon is vase in shape, and the acrosome is cone type. The axoneme of the tail flagellum consists of nine pairs of microtubules at the periphery and a pair of central microtubules in the center The satellite body (which is formed by the centriole) and four mitochondria appear in the middle piece of the spermatozoon. The spawning period was from April through July and the main spawning occurred from May to June when seawater temperatures gradually increased. The reproductive cycle of this species can be classified into five successive stages; early active stage (September to November), late active stage (October to March), ripe stage (February to August), spawning stage (April to July), and spent/inactive stage (July to November).

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한국산 둥근전복, Haliotis discus discus의 생식주기 (Reproductive Cycle of the Abalone, Haliotis discus discus Collected from Jeju Island of Korea)

  • 김재원;이병욱;강주찬;민은영;원승환;임한규;강승완;전미애;이정식
    • 한국패류학회지
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    • 제31권1호
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    • pp.21-26
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    • 2015
  • 본 연구에서는 한국 제주도에 서식하는 둥근전복의 생식소 발달과 생식주기를 조직학적으로 기재하였다. 생식소는 조직학적으로 계절적인 변화를 보였다. 암컷의 비율은 59% (n = 182/309) 로 조사되었다. 생식소지수는 암, 수 모두 9월에 최고값 (3.2, 3.3) 을 보였으며, 1월과 2월에 최저값 (1.7, 1.4) 을 보여주었다. 난경 조성 변화는 3월의 초기성장기부터 점차 증가하기 시작하여 완숙기인 8월에 $180{\mu}m$ 전후의 난경을 나타냈다. 비만도는 암,수 모두 7월에 최고값 (0.0748, 0.0760) 을 보였으며, 5월에 최저값 (0.0268, 0.0278) 을 나타냈다. 생식소지수, 난경 및 비만도는 생식소조직의 계절적 변화와 유사한 양상을 나타냈다. 생식주기는 비활성기 (11월-12월), 초기활성기 (1월-3월), 후기활성기 (3월-4월), 완숙기 (5월-6월), 방출 및 퇴화기 (7월-10월) 로 구분할 수 있다. 2014년 제주도에서 둥근전복의 주산란기는 8월-10월 이었다.

클로렐라의 동조배양법에 의한 세포분열의 생리학적 연구 2 (Physiological studies on cell division by the technique of synchronous culture of chlorella (II))

  • 이영녹;심웅섭
    • 미생물학회지
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    • 제7권1호
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    • pp.10-21
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    • 1969
  • The effect of glucose and 2-thiobarbituric acid on the biosynthesis of cell constituents such as protein, carbohydrate, DNA, RNA, phospholipid and PCA-soluble phosphate compounds in Chlorella duing the life cycle was measured, and the changes in the content of these main cellular components of the algal cell were analyzed in connection with the nuclear and cytoplasmic divison. In the normal autotrophic synchronous culture the contents of protein, RNA, and DNA in the cell showed a chracteristic changes according to the progress of cell development, increasing more or less throughout all the life cycle. The synthesis of protein is more prominent in the division period nad that of DNA is more active in the ripening period, while the synthesis of RNA is more rapid in the growing and ripening periods than other developmental stages. The period of division cycle was little affected by glucose in the medium, although the synchrony of the growth and cellular division was disturbed and the n value increased. The cotents of protein, carbohydrate, RNA nad DNA of the cell were increased by the glucose treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment. The synthesis of protein, carbohydrate, DNA, RNA and phospholipid of the cell was also retarded by 2-thiobarbituric acid. In the autotrophic, mixotrophic and 2-thiobarbituric acid-treated cultures, each having different mode cytoplasmic division, a common general schema occurring in the cell during the life cycle may be drawn as follows. The ratio of RNA to protein attains maximum value in the $L_1$-cell stage prior to the nuclear division and thereafter decreases during the periods of ripening and division. The ratio of PCA-soluble phosphate compounds to protein increased from the begining of the culture to $L_4$-cell stage successively and thereafter decreased gradually during the division period, while the ratio of protein to DNA kept almost constant up to the division period and thereafter increased during the division period. Therefore, it is presumed that the increase in the ratio of RNA to protein is to be an inducer of nuclear division and that the cytoplasmic division is induced by the increase in the ratio of protein to DNA.

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Function of the pentose phosphate pathway and its key enzyme, transketolase, in the regulation of the meiotic cell cycle in oocytes

  • Kim, Yunna;Kim, Eun-Young;Seo, You-Mi;Yoon, Tae Ki;Lee, Woo-Sik;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
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    • 제39권2호
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    • pp.58-67
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    • 2012
  • Objective: Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). Methods: We evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi). Results: Despite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process. Conclusion: We concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.

확산단계에 따른 경쟁요인 변화 연구:Tablet과 노트북 사례를 중심으로 (A Study on the Change of Competition Factors According to Diffusion Stage - Focusing on the Case of Tablet and Notebook PCs)

  • 서영일;장준규;이준기
    • 한국콘텐츠학회논문지
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    • 제15권7호
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    • pp.128-137
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    • 2015
  • 정보통신(IT) 분야는 변화가 빠르게 진행되었다. 많은 혁신제품이 출시되고, 일부는 안정적으로 시장을 형성하여 확산되지만, 일부는 사라져 버린다. 본 연구에서는 스마트기기 간 시간의 경과에 따른 경쟁요인을 도출하였다. 혁신확산이론(IDT)의 혁신채택단계를 산업수명주기이론(ILC)의 산업수명주기에 적용하여 도입기, 성장기, 성숙기의 3단계로 구분하여 시간의 흐름에 따른 시장특성 모형을 정의하였다. 노트북 컴퓨터와 태블릿 사례의 경쟁관계를 분석하여 제안된 이론적 모형의 적합도를 확인하였다. 시간의 흐름에 따라 5가지의 경쟁요인은 다르게 작용하며 도입기에는 기능성과 유희성이 중요한 경쟁요인이 되고, 성장기에는 기능성과 유희성 외에도 적합성이 추가적으로 작용함을 알 수 있었다. 마지막의 성숙기에는 적합성과 복잡성, 그리고 비용수준이 중요한 경쟁요인이었다.

상한위치분석을 통한 농촌체험관광마을의 생애주기별 발전방안 -합전마을을 중심으로- (Development Plans by Life-Cycle of Rural Experience Tourism Village using Positioning Analysis - Focused on Hapjeon-village -)

  • 최애순;정남수;정다영;송이;엄성준;최세현;리신호
    • 농촌계획
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    • 제20권2호
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    • pp.11-22
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    • 2014
  • In this study, the objectives are to provide rural experience tourism village business courses and development direction in between individual farmers and the village in base on rural development business of Hapjeon-village. The developmental process of a farm-stay village can be categorized into the period of six stages: 1) a conception stage 2) an adoption stage 3) a growth stage 4) an expansion stage 5) a stagnation stage 6) a recovery stage. Farm Stay Villages, Individual Farmhouses or Producer Groups can be placed in four different quadrant areas of a graph, depending on the pursuing direction and results of core values by having the X-axis for economic factors (public profits, individual profits) and by having the Y-axis for emotional factors (self-actualization, conflicts). The first quadrant area is designated for ideal individual farmhouses and producer groups for having achieved the status of economic self-reliant and high emotional satisfaction. The second quadrant is for ideal self-actualized communal villages having achieved the independent public interest and public profitable status. The third quadrant is reserved for villages experiencing communal conflicts and no economic self-reliant stagnant status. The fourth guardant area is allocated for individual farmhouses and producer groups having achieved self-reliant economic status, yet having communal conflicts. Using the aforementioned concept, the government shall design village development projects and prepare realistic and achievable goals and place them in as a systematic device in future projects.

부부의 갈등과 생활만족도에 관한 연구 -형성기 가정과 확대기 가정을 중심으로- (A Study on Marital Conflict and Life Satisfaction -As Related to Establishment Family and Expanding Family-)

  • 김재경;문숙재
    • 가정과삶의질연구
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    • 제10권1호통권19호
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    • pp.53-74
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    • 1992
  • The purpose of this study was to analyse the factors that influence marital conflicts and family life statisfaction, and to predict the future stage of establishment family and extending family, bsed on the theretical model by system approach. For this pourpose, 336 couples of urban households in Seoul were selected. The data were analysed through statistical methods such as, Frequency, percentile, T-test, F-test, ANOVA, Pearson's correlation analysis. The results were as follow : The Martial Conflict and family life satisfaction of surveyed couples were above middle level. It had significantly differences according to family life cycle, husband and wife's educationed levels, husband and wife's occupations, and family income. And Family life satisfaction had significantly differences according to marital conflict. The marital conflict is higher, life satisfaction is lower. In this study, it were appeared that the amount of marital conflict and life satisfaction had differences according to life cycle stages, husband and wife's educational level, husband and wife occupations, and family income, and so that the conflict of phsycho-social system was more affected on family life satisfaction that of managerial system. Such results were indicated that the birth of children was the critical family event affecting on family life satisfaction on and the marital conflict. But the conflict by family's given resources and situational differences also as an environment affection on the family system.

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Life Cycle of the Perilla Leaf Pyralid Moth, Pyrausta panopealis (Lepidoptera: Pyralidae) and Test of Larvicidal Effect of Some Commercial Natural Products

  • Oh, Hyung-Keun;Kim, Won-Kee;Kang, Ah-Rang;Kim, In-Seon;Lee, Hyang-Burm;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제21권1호
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    • pp.133-137
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    • 2010
  • The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage was investigated under five temperature regimes ($20^{\circ}C{\sim}30^{\circ}C$). The larval period of P. panopealis was longest as 26.8 days at $20^{\circ}C$ and shortened as temperature goes up to $30^{\circ}C$ as 11.3 days. Survivorship of the larval P. panopealis was the highest at $27.5^{\circ}C$ as 82.5%, whereas that of other temperatures ranged from 40% ($20^{\circ}C$) to 60.0% ($30^{\circ}C$), indicating that the P. panopealis appears to favor somewhat higher temperature. In addition to larval period, the duration of egg, prepupal, and pupal period also were shortened sharply as temperature goes up, whereas the duration of adult stage shortened a maximum of only two days as temperature goes up. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of ten on-the-market environmentfriendly agricultural materials (EFAMs) that were previously selected from the result of other moth species was tested. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

생태효율성(Eco-efficiency)지표 개발을 통한 KTX와 새마을호 열차의 사용단계 환경성 평가에 관한 연구 (A Study on the Environmental Evaluation in Use Stage of KTX and Samaul Train : the Development of Eco-efficiency Indicator)

  • 최용신;천윤영;이건모;김용기
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1313-1320
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    • 2011
  • World Business Council for Sustainable Development(WBCSD) is effort to achieve sustainable development in economic growth, environmental preservation and social development. Being this way, it is essential for developing evaluation tool which quantify to fulfill sustainable development. Eco-efficiency is one of the quantitative tools to evaluate environmental impact and economic aspect. Eco-efficiency, in general term, means creating more value of product or services with less impact to environment. It indicates as environmental impact in denominator and value of product or services in numerator. Eco-efficiency shows how much economic value reveals to unit environmental impact caused by product or service as an indicator. This study aims at developing eco-efficiency indicator of railway industry considering use stage among the entire life cycle stage of KTX and Saemaul train and also, figure out eco-efficiency value through indicator. Therethrough, it is enables to evaluate created value per environmental aspects. Since rail vehicles demands a lot of energy to transport people during use stage, the environmental impact is more significant than other lkfe cycle stages. Therefore, it quantified environmental indicator as CO2 emission and economic indicator as transportation record per a year with an annual income. This study contributes to be used as a tool for quantifying indicator of comparison evaluation in respect of rail vehicle in use stage.

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Life Cycle Impacts of Flexible-fiber Deep-bed Filter Compared to Sand-Filter including Coagulation and Sedimentation in Water Treatment Plant

  • Uh, Soo-Gap;Kim, Ji-Won;Han, Ki-Back;Kim, Chang-Won
    • Environmental Engineering Research
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    • 제13권1호
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    • pp.1-7
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    • 2008
  • Recently a new technology called the flexible-fiber deep-bed filter (FDF) claimed to replace the conventional sand filter including coagulation and sedimentation filter (CSF) processes in the water treatment plant. Therefore the life cycle assessment (LCA) approach was applied for evaluating the life cycle impacts of FDF compared with those of CSF. The used LCA softwares were the Simapro 6 and PASS and their life cycle impact assessment (LCIA) methodologies were the Eco-indicator 99 and the Korean Eco-indicator, respectively. The goal of this LCA was to identify environmental loads of CSF and FDF from raw material to disposal stages. The scopes of the systems have been determined based on the experiences of existing CSF and FDF. The function was to remove suspended solids by filtration and the functional unit was $1\;m^3$/day. Both systems showed that most environmental impacts were occurred during the operation stage. To reduce the environmental impacts the coagulants and electricity consumptions need to be cut down. If the CSF was replaced with the FDF, the environmental impacts would be reduced in most of the impact categories. The LCA results of Korean Eco-indicator and Eco- indicator99 were quite different from each other due to the indwelling differences such as category indicators, impact categories, characterization factors, normalization values and weighting factors. This study showed that the life cycle assessment could be a valuable tool for evaluating the environmental impact of the new technology which was introduced in water treatment process.