• Weed & Turfgrass Science
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• v.7 no.3
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• pp.275-282
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• 2018

Miscanthus species are known as a genus of eco-friendly and low-maintenance cost ornamental grasses. Plug and cutting methods were tested for multi-propagation of most promising ornamental Miscanthus species in greenhouse and field plot. The plug formation period with three different cell sizes with four cultivars (M. sinensis 'Andersson', 'Strictus', 'Gracillimus', 'Variegatus') were evaluated the seedling development stages with two irrigation types of the over-head and the bottom watering in greenhouse and field plot afterward during 2015-2016 season. In seedling plug test, the size of tray cell affected the plug formation. Bottom irrigation resulted positively on plant height, weight, root and tiller development compared with the over-head irrigation. Plug cell size affected the plant growth in the field after transplanting. All of the 3 Miscanthus species showed higher rates of successful propagation at the lower nodes before inflorescence formation (vegetative growth stage). To analyze the survival factors of M. xgiganteus cutting, the cutting time, node part, and culm diameter were tested as independent variables with the binary logistic model. The survival probability was influenced by node part and culm diameter significantly. The third and fifth node parts showed 0.12 (8X higher failure probability) and 0.02 (50X higher failure probability) times less survival probability. It means the survival probability will be increased by using older and lower part of cuttings during a vegetative growth stage before inflorescences of M. xgiganteus.

• Korean Journal of Plant Taxonomy
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• v.46 no.2
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• pp.256-266
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• 2016

A total of 13,000 individuals of Dendrobium moniliforme (L.) Sw. artificially propagated in laboratories and greenhouses were restored in their natural habitat of Bogildo Island, Wandogun, in the southern part of Korea in June of 2013. The growing conditions of the individuals were monitored for two years. The parental individuals for the restoration were obtained from a wild population in southern Korea, from which seeds were produced via artificial crossings. These seeds were germinated and cultivated in growing media and two-year-old plants were then grown in greenhouse beds. The genetic diversity among the propagated individuals was confirmed by examining DNA sequences of five regions of the chloroplast genome and the nuclear ITS region. The diversity values were as high as the average values of natural populations. All propagated individuals were transplanted into two different sites on Bogildo by research teams with local residents and national park rangers. After restoration, we counted and measured the surviving individuals, vegetative propagated stems, and growth rates in June of both 2014 and 2015. There was no human interference, and 97% of the individuals survived. The number of propagules increased by 227% in two years. In contrast, the average length of the stems decreased during the period. In addition, different survival and propagation rates were recorded depending on the host plants and the restored sites. The shaded sides of rock cliffs and the bark of Quercus salicina showed the best propagation rates, followed by the bark of Camellia japonica. A few individuals of D. moniliforme successfully flowered, pollinated, and fruited after restoration. Overall, our monitoring data over two years indicate that the restored individuals were well adapted and vigorously propagated at the restored sites. In order to prevent human disturbance of the restored sites, a CCTV monitoring system powered by a solar panel was installed after the restoration. In addition, a human surveillance system is operated by national park rangers with local residents.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.141-150
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• 1994

Morphological features of the interaction between the hatching blastocyst and implantation in pig were studied by electron microscopy. The observations extended from late blastocyst stage to the completion of trophoblastic erosion of the epithelium and early decidual transformation of the epithelium and early decidual transformation of the stromal cells. Between day 7 and 17 of pregnancy, blastocysts from 0.3 to 12 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. On the 7th of development in the pig blastocyst, the blastocyst shedded of the zona pellucida established the tips of microvilli and with bleb-like cytoplasmic protrusions of the epithelial cells. From day 11 on in pig embryo, the bilayered trophoblast undergoes a dramatic phase of elongation so that the initially spherical expanded blastocyst becomes tubular. In pig, close apposition to the uterine wall beg-ins at about 12 $^1$/$_2$ days and then attachment occurred during the afternoon of the 16th or 18th day post coitum. At this stage, embryonic loss compared with corpus luteum number is up to 40% of ovulated oocytes. Therefore, the implantation failture of these embryos may be mainly caused by morphological abnormality and failture of zona shedding.

• Korean Journal of Animal Reproduction
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• v.15 no.1
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• pp.49-57
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• 1991

This study was carried out to investigate the effect of equilibration time, precooling and straw loading method on the post-thaw survival rates of mouse embryos cryopreserved by vitrification method. The effect of the vitrification procedure on the damage of the embryos was also examined by the straining of nuclei using Hoechst 33342. The results obtained were summarized as follows; 1. The equilibration in Medium-1 for 10 minutes was considered to be the optimum equilibration time. Embryos equilibrated in Medium-1 for 10 minutes(81.0%) showed significantly(P<0.05) higher survival rates than those equilibrated for 5 minutes(40.0%) or 15 minutes(74.1%). 2. The survival rate of embryos cryopreserved using the double Medium-2 column(81.0%) was significantly(P<0.01) higher than that using the single Medium-2 column, whish was considered to be due to the double Medium-2 column method being more reliable for preventing contamination of diluent solution of 1M sucrose. 3. The survival rate of compacted morula stage embryos cryopreserved with the precooled and non-precooled Medium-2 was not significantly(P<0.05) different. 4. The number of blastomeres of embryos at late blastocyst stage after culture of mouse morulae for 24 to 28hours was significantly(P<0.05) decreased by freezing embryos using vitrification(53.3${\pm}$1.6 vs 41.4${\pm}$1.5), which was considered to be due to the damage of embryos during vitrification and the delay of embryo development by handling in vitro. 5. The vitrification procedure is considered to be a very simple and efficient method for cryopreservation of embryos at early developmental stage.

• The Korean Journal of Applied Statistics
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• v.8 no.2
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• pp.147-161
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• 1995

The primary objective of this paper is to review parametric models and test statistics related to overdspersion of count data. Poisson or binomial assumption often fails to explain overdispersion. We reviewed real examples of overdispersion in count data that occurred in toxicological or teratological experiments. We also reviewed several models that were suggested for implementing experiments. We also reviewed several models that were suggested for implementing the extra-binomial variation or hyper-Poisson variability, and we noted how these models were generalized and further developed. The approaches that have been suggested for the overdispersion fall into two broad categories. The one is to develop a parametric model for it, and the other is to assume a particular relationship between the variance and the mean of the response variable and to derive a score test staistics for detecting the overdispersion. Recently, Dean(1992) derived a general score test statistics for detecting overdispersion from the exponential family.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.146-147
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• 2015

현재 선박이나 교각 해양플랜트는 많은 철판으로 구성이 되어 있다. 특히 해양플랜트와 선박에는 오랜시간 바다에 있으므로 각종 해양생물들이 붙어 번식을 한다. 이러한 해양생물은 선박의 속도 및 연료 소모에 상당한 영향을 미친다. 그러므로 선박이나 해양플랜트 구조물은 정기적으로 벽면에 서식하는 해양생물을 제거하고 있으며 이러한 제거과정과 도장을 다시하는 과정에서 작업자들에게 위험이 따른다. 본 연구는 선박이나 해양플랜트와 같은 철로된 구조물의 위험한 작업을 대신할 로봇의 기반인 철판 벽면을 이동하는 로봇을 연구하였다. 현재 많은 벽면 로봇들이 연구되고 있다. 영구자석 또는 전자석 휠을 사용하거나 공압을 이용하여 수직벽면에서 작업을 한다. 특히 공압 방식을 많이 사용하였는데 수직벽면에 로봇이 밀착될 만큼 강한 공압이 필요하게 되기 때문에 부가적인 장치가 많이 필요하다. 본 논문에서는 부가적인 장치를 최소화하고 효과적인 동작을 하기위해 전자석 방식을 선택 하였으며 간편하게 선박의 수직벽면을 작업할 수 있는 전자석 방식의 4 륜 로봇을 개발하고자 한다. 선박의 수직벽면 작업용 4 륜구동 로봇을 전자석을 이용하여 수직벽면에 부착할 수 있도록 설계하였으며 자력의 세기와 방향을 제어하여 로봇이 선박의 수직면에 밀착되어 자유롭게 이동이 가능하도록 개발 하고자 한다.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.94-103
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• 2002

To suggest basic research data for a plan raising naturalness of urban park forest, the structure of forest vegetation and bird community were analyzed in four urban parks of Gwangju city. And also, their relationships were discussed. Some of the structural characteristics in the two communities were closely related to each other. Species and individual densities of birds were relatively high in Songjong and Sangmu park showing the vigorous successional progress, but were low in Anchong park with simple vegetation. The bird group that nest and feed in canopy or dead wood held occupy the highest percent in Sajik park with well developed upper layer of forest, the bird group that nest and feed in shrub did in Sangmu park with developed middle layer, and the bird group that feed in ground did in Songjong park with developed low layer. Relationship between the species diversities of forest and birds was not significant. Nevertheless, bird diversity was relatively high in Sajik and Sangmu park with the high proportion of broad-leaved trees in upper and middle layers.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.385-393
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• 1997

다세포 생물에서 몸의 효율적 생존을 위한 각 기관의 homeostasis는 세포 증식과 사망에 의해 조절된다. 따라서, apoptosis라 명명된 세포사망은 정교한 기전에 의한 능동적이고 자발적인 사망기전으로써 몸의 정상적 유지를 위한 필수적인 현상이다. 발생기 세포나 신경세포 또는 흉선세포 분화 동안 과다한 세포의 제거가 apoptosis의 대표적인 예이며, 각종 호르몬에 의해 그 기능이 조절되는 난소세포에서도 apoptosis가 활발히 일어난다. Rat난소에는 태어날 때 수십 만개의 난포를 지니고 있는데, 이 중 단지 1%만이 배란에 사용되어질 뿐이고 나머지는 모두 사망하게 된다. 이러한 난포사망은 난소의 적절한 세포 수를 유지하기 위한 필수적 과정이며, 인위적으로 apoptosis를 억제하는 유전자인 bcl-2를 과다 발현시키면 난소암이 발생하는 연구결과가 이를 입증해주고 있다. 이처럼 중요한 난포 사망기전은 apoptosis라는 개념이 정립되면서 최근 들어 점차 그 연구가 활발해지고 있다. Apoptosis의 특징 중 뚜렷한 점은 DNA가 일정한 간격으로(180∼200 bp)잘려지는 DNA fragmentation현상으로, 이를 이용하여 DNA3'-end 부위에 방사선동위원소를 label한 후 이를 전기영동으로 분리하면 apoptosis를 손쉽게 측정할 수 있다. 난소의 기능은 시상하부호르몬인 LH와 FSH 뿐만 아니라 난소에서 분비되는 각종 난소국부호르몬들에 의해 조절된다. 특정한 발육단계의 난포는 특정한 호르몬에 의해 그 기능을 조절 받는데, 이러한 난소기능 조절기작은 매우 복잡한 경로를 지니고 있다. 이러한 복잡한 기작으로 인해 초기 연구에서첨 생체 내에서 밝히려는 연구 시도는 어려움에 부딪치게 되었다. 생체내 실험은 난소가 다양한 발육단계의 난포를 동시에 지니고 있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.413-421
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• 1997

In vitro culture has provided new information on the mechanisms involved in fertilization how sperm and oocyte fuse together. At the same time, results obtained in vitro have led to new questions. Techniques for In vitro maturation of porcine oocytes have progressed such that the problem of the low rate of pronucleus formation with in vitro matured oocytes after in vitro fertilization has been nearly improved. On the other hand, porcine spermatozoa have been shown to be capacitated if the fertilization medium contains caffeine and Ca$^2+$, but the incidence of polyspermy in IVM-IVF oocytes is still high. To prevent polyspermy, co-culture with oviductal cells, sperm preincubation with porcine follicular fluid or control of sperm concentration, have been examined with significant effects but still remarkably high rates of polyspermy. The under standing of these influences is a prerequisite to enhancing in vitro production of porcine em bryos.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.197-206
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• 2003

hFSH (human follicle stimulating hormone) is heterodimer consisting of $\alpha$ and $\beta$ subunits. Since assembly of the both subunits in the cell is often the rate-limiting step in production of functional hormone, single-chain hormones have been engineered by genetically linking two different cDNA fragments with a linker sequence. Using retrovirus vector system, the resulting recombinant hFSH gene was transferred in CHO cells and chicken embryos, and the expression of the gene was investigated. In CHO cells, protein synthesis from the single-chain FSH gene was 17 fold higher than that from the heterodimeric counterpart. In the study of transgenic chickens, ten of the eleven chicks hatched from 62 embryos manupulated with recombinant retrovirus stock was determined to carry transgenic genes. RT-PCR analyses confirmed transcription of the single-chain FSH gene, however, no recombinant FSH was detected from the blood samples.