• 한국패류학회지
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• 제30권4호
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• pp.333-342
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• 2014

Ultrastructural studies of oogenesis in oocytes, oocyte degeneration associated with the follicle cells in female Coecella chinensis were investigated for clams collected from Namhae, Geongsangnam-do, Korea. In this study, vitellogenesis during oogenesis in the oocytes occured by way of endogenous autosynthesis and exogenous heterosynthesis. Of two processes of vitellogenesis during oogenesis, the process of endogenous autosynthesis involved the combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum. whereas the process of exogenous heterosynthesis involved endocytotic incorporation of extraovarian precursors at the basal region of the oolema of the early vitellogenic oocytes prior to the formation of the vitelline coat. It is assumed that the follicle cells were involved in the development of previtellogenic and early vitellogenic oocytes and appear to play an integral role in vitellogenesis in the early and late vitellogenic oocytes by endocytosis of yolk precursors, and also they were involved in oocyte degeneration by assimilating products originating from the degenerated oocytes, thus allowed the transfer of york precursors needed for vitellogenesis (through phagocytosis by phagolysosomes after spawning). Follicle cells presumably have a lysosomal system for breakdown products of oocyte degeneration. and for reabsorption of various phagosomes (phagolysosomes) in the cytoplasm for nutrient storage during the period of oocyte degeneration.

• KDI Journal of Economic Policy
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• 제40권1호
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• pp.31-43
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• 2018

There is a large amount of empirical literature reporting that people who regularly attend religious services tend to have better health outcomes. However, it remains an unanswered question as to whether the observed correlation reflects any causality. Exploiting exogenous changes in church attendance driven by law changes in 21 states of the U.S., I find tentative but suggestive evidence that the observed strong correlation between religious participation and health is likely to be driven by endogenous selection.

• 한국조경학회지
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• 제23권4호
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• pp.50-60
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• 1996

The purpose of this study is to investigate the prime factors that affect user satisfaction of area and facilities in urban forests, to classify those factors, to find out factorial structure of user satisfaction about them, and then to suggest important indicators in the urban forest planning, design, and development. The survey research was done using the self-administered questionnaire method by the people in the city of the Pusan who participated in recreational activities in the Mt. Keumjung. Factor analysis was used to extract the prime factors related to the recreational satisfaction concerning the area and facilities of the urban forest by the SPSS program, and then prime factors were used to investigate the factorial structure of user recreational satisfaction in the urban forest by the LInear Structure RELation program. According to the factor analysis concerning the 13 variables, 4 prime factors by the statistical values were considered as effective, indicating, 'health and recreational facilities', 'convenience and management facilities','facilities for the physical and psychological training' and 'historical and cultural areas'. The results of the causal structure analysis were identified as having significant effects mutually on endogenous variables, 'overall recreational satisfaction of the areas and facilities in the Mt. Keumjung','health and recreational facilities','convenience and management facilities','facilities for the psychological training', and 'historical and cultural areas'. But exogenous variables which have significant effects on endogenous variables were also indentified. Overall fits of both causal model were very good. The hypothetical causal structural equation models based on the results found partially significant correlation between dndogenous variables and between envogenous and exogenous variables. These significant relationships indiate important factors and variables that should be considered in planning, design, and development of the urban forests. Therefore, development direction of the Mt. Keumjung has to be analyzed as significant factors concerning user recreational satisfaction in a systematic was, recognized as important variables for planning process. The plan for development and management also should reflect the natural conservation policy from the environmental conservation movement like natural conservation advertisement and environmental education.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.33-33
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• 2017

Water stress obstructs rice growth mainly by oxidative damage in biological cells to cause a reduction of leaf photosynthesis and evapotranspiration processes. In this study, exogenous application of vanillic acid (VA) and p-hydroxybenzoic acid (PHBA) to improve drought tolerance of two Oryza sativa cultivars, Q2 and Q8 was tested. The drought evaluation based on leaf phenotypes to show that both Q2 and Q8 resulted in remarkable water-stress tolerance induced by leaf spraying pretreatment of mixed solution of $50{\mu}M\;VA+50{\mu}M\;PHBA$. The mixtures of $25{\mu}M\;VA+25{\mu}M\;PHBA$ and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treated on Q2 and Q8 in water deficit condition also indicated that total phenols, total flavonoids, and DPPH radical scavenging activity were significantly greater their controls. In general, the accumulation of individual phenolic acids was increased in exogenous phenolic treatments, as compared with controls. Particularly, Q2 obtained a considerable amount of endogenous PHBA after application of $50{\mu}M\;VA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ (0.18 mg/g DW, 0.71 mg/g DW, and 1.41 mg/g DW, respectively); and a negligible content of VA (0.003 mg/g DW) appeared uniquely in the treatment of $50{\mu}M\;VA$. Similarly, Q8 also absorbed a significant quantity of PHBA in $50{\mu}M\;PHBA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treatments (0.15 mg/g DW, 0.15 mg/g DW, and 0.22 mg/g DW, respectively). In addition, the spraying $50{\mu}M\;PHBA$ and $25{\mu}M\;VA+25{\mu}M\;PHBA$ on Q8 leaves induced similar amount of VA (0.04 mg/g DW). Meanwhile, there were no trace of VA and PHBA found in controls. The levels of drought tolerance of Q2 and Q8 were improved, paralleled with the increased amounts of endogenous phenolics revealed that VA and PHBA played an important role to enhance drought tolerance in rice.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.38-38
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• 2017

Water stress obstructs rice growth mainly by oxidative damage in biological cells to cause a reduction of leaf photosynthesis and evapotranspiration processes. In this study, exogenous application of vanillic acid (VA) and p-hydroxybenzoic acid (PHBA) to improve drought tolerance of two Oryza sativa cultivars, Q2 and Q8 was tested. The drought evaluation based on leaf phenotypes to show that both Q2 and Q8 resulted in remarkable water-stress tolerance induced by leaf spraying pretreatment of mixed solution of $50{\mu}M\;VA+50{\mu}M\;PHBA$. The mixtures of $25{\mu}M\;VA+25{\mu}M\;PHBA$ and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treated on Q2 and Q8 in water deficit condition also indicated that total phenols, total flavonoids, and DPPH radical scavenging activity were significantly greater their controls. In general, the accumulation of individual phenolic acids was increased in exogenous phenolic treatments, as compared with controls. Particularly, Q2 obtained a considerable amount of endogenous PHBA after application of $50{\mu}M\;VA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ (0.18 mg/g DW, 0.71 mg/g DW, and 1.41 mg/g DW, respectively); and a negligible content of VA (0.003 mg/g DW) appeared uniquely in the treatment of $50{\mu}M\;VA$. Similarly, Q8 also absorbed a significant quantity of PHBA in $50{\mu}M\;PHBA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treatments (0.15 mg/g DW, 0.15 mg/g DW, and 0.22 mg/g DW, respectively). In addition, the spraying $50{\mu}M\;PHBA$ and $25{\mu}M\;VA+25{\mu}M\;PHBA$ on Q8 leaves induced similar amount of drought tolerance of Q2 and Q8 were improved, paralleled with the increased amounts of endogenous phenolics revealed that VA and PHBA played an important role to enhance drought tolerance in rice.

• BMB Reports
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• 제56권6호
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• pp.321-325
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• 2023

RNAs are pivotal molecules acting as messengers of genetic information and regulatory molecules for cellular development and survival. From birth to death, RNAs face constant cellular decision for the precise control of cellular function and activity. Most eukaryotic cells employ conserved machineries for RNA decay including RNA silencing and RNA quality control (RQC). In plants, RQC monitors endogenous RNAs and degrades aberrant and dysfunctional species, whereas RNA silencing promotes RNA degradation to repress the expression of selected endogenous RNAs or exogenous RNA derived from transgenes and virus. Interestingly, emerging evidences have indicated that RQC and RNA silencing interact with each by sharing target RNAs and regulatory components. Such interaction should be tightly organized for proper cellular survival. However, it is still elusive that how each machinery specifically recognizes target RNAs. In this review, we summarize recent advances on RNA silencing and RQC pathway and discuss potential mechanisms underlying the interaction between the two machineries.

• 한국패류학회지
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• 제32권1호
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• pp.17-23
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• 2016

암컷 떡조개, Phacosoma japonicus의 난모세포 발달과 보조세포들과 관련된 난황형성과정의 미세구조적 연구를 위해 전자현미경적 관찰에 의해서 조사를 하였다. 난모세포들 내에서의 난황형성과정은 내인성 자율합성과정과 외인성 타가합성에 의해 일어나고 있다. 내인성 자율합성과정을 통해 일어나는 난황형성은 난모세포질 내의 골지복합체, 조면소포체 그리고 미토콘드리아가 결합된 작용에 의해서 일어난다. 그러나 외인성 타가합성과정은 초기난황형성난모세포들의 기저부로 들어오는 난소외부의 난황전구체물질들의 내포작용 (endocytosis)의 결합이 관여하고 있다. 본 연구에서 전난황형성난모세포들과 난황형성난모세포들에 부착된 보조세포들이 용이하게 관찰되었다. 특히, 보조세포들은 영양공급에 의해 전난황형성 난모세포들의 발달에 관여하며, 난황전구체의 엔도시토시스에 의해 초기 및 후기 난황형성 난모세포들 내에서 난황형성에 관여한다. 성숙난모세포에 부착된 보조세포들의 기능은 보조세포들의 세포질 내에서 난황형성을 위해 지질과립들과 글리코겐입자들을 축적한다.

• 한국가축번식학회지
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• 제22권1호
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• pp.81-87
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• 1998

This experiment was carried out with 12 Korean native heifers(8~12month old, body weight, 160~240kg) raised at a farm of Chang-Soo Livestock Cooperatives to evaluate the effects of rGH(recombinant growth hormone) on serum concentrations of growth hormone, estrogen, and IGF-I, weight gain, teat volume gain and processing enzyme activity of IGF-I, binding protein III at 28 day intervals. Animals used were injected with 250mg rGH at 14 day intervals from December to Ferbruary in 1994. The significant difference was found in the group of treatment on the 4th week in the endogenous GH(p<.01) and 8th week in estrogen and IGF-I(p<.05) after injectin of rGH in Korean native heifers. There were significant differences between control group and treatment group in weight and teat volume on 8th week after treatment(p<.05). Processing enzyme activity before injection of rGH were low. However, heifers injected with 250mg of rGH showed that processing enzyme activity of IGF binding protein was highly increased throughout the experiment. Present results suggest that injection of exogenous rGH to heifers can increase the growth performance and udder development of Korean native heifers by the endogenous hormonal changes.

• 한국발생생물학회지:발생과생식
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• 제2권2호
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• pp.149-155
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• 1998

폴리시알린산 (polysialic acid)은 미생물로부터 인간에 이르기까지 다양한 세포의 세포 표면 복합당사슬에 공유 결합하는 당사슬의 일종이다. 최근 성게 난자의 젤리층과 성게 난자의 표면에서 폴리시알린산이 연결된 당단백질이 발견됨으로써 폴리시알린산의 생합성과 그 기능에 대한 의문이 제기되었다. 둥근성게의 난자와 배에서 추출한 효소액과 CMP-[$^{14}$ C]Neu5Ac를 기질로 사용하여 Neu5Ac를 endogenous acceptor에 전달하는 CMP-Neu5Ac:poly-$\alpha$2, 8 sialosyl sialyltransferase (polyST)를 발견하였다. polyST는 20mM MOPS (pH 7.0), 2$0^{\circ}C$에서 최적 활성을 나타냈다. 10 mM $Mg^2$$^{+}$를 효소 반응액에 첨가하면 polyST의 황성은 2.7배 증가하였다. poiyST는 또한 포유류의 gang1ioside인 GD3에 폴리시알린산을 합성할 수 있었다. 이와 같은 폴리시알린산이 존재하는 ganglioside가 현재까지 자연계에서 알려진 바가 없다는 사실은 하나의 polyST가 endogenous acceptor와 ganglioside에 폴리시알린산을 합성했다고 결론지을 수 있다. 과량의 GD3를 exogenous acceptor로 사용하여 둥근성게에 존재하는 polyST의 활성을 조사한 결과 mesenchyme 포배기 때부터 그 활성이 급격히 증가하고 낭배기 때에 최고에 도달했다. 성게의 배발생 때에 polyST의 활성이 조절된다는 것은 낭배기 때에 일어나는 세포나 조직 사이에 일어나는 변화와 초기 단계 spicule 형성에 어떤 중요한 기능을 담당하고 있을 가능성이 있다.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.27-34
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• 2010

A fertilized oocyte can get the competence for implantation through cleavage and stage-specific gene expression. These are under the control of autonomous and exogenous regulators including physiological culture condition. Endogenous and exogenous growth factors are considered as critical regulators of cleaving embryos during travel the oviduct and uterus. In this study, an effort was made to evaluate comprehensively the quality of embryos for implantation, grown in media enriched with EGF and PAF. The study evaluated developmental rates on given time, blastulation and hatching rates, and adhesion rates. Developmental rates of blastocyst to the hatching stage were significantly high in PAF treated group compared to the control in a dose-dependent manner but not in EGF group. Implantation rates were significantly high both PAF and EGF in a dose-dependent manner. H7, a PKC inhibitor, blocked the process of hatching of the blastocysts but combined treatment of EGF and PAF enhanced the hatching and implantation of blastocsyts. Based on these results it is suggested that EGF and PAF support acquirement of implantation competence at blastocyst stage through a PKC pathway.