• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.33 no.3
• /
• pp.110-121
• /
• 2021

The importance of tidal flats lost due to industrialization has recently received attention, and attention is being paid to the creation of artificial tidal flats and maintenance of natural tidal flats. However, there is still a lack of understanding about the behavioral characteristics of mud, mud, and sand that form tidal flats. Although research on the movement characteristics of mixed soils such as tidal flats has been conducted through field investigations and hydraulic experiments, interest in developing a numerical model based on these results has not yet reached. In this paper, the purpose of this paper is to establish a mixed soil model that can efficiently manage the low quality of the tidal flats. In constructing a model for reproducing the surface movement of mixed soil, the numerical stability of the reproduction and movement of sand and mud constituting the mixed soil in the numerical model should be considered first, so first, the volume of sand and mud constituting the mixed soil A mixed soil model representing the relationship was proposed based on a topographical diagram representing the geometric structure of the mixed soil. In order to consider the dry bulk density of the mixed soil, it was possible to consider the dry bulk density of the mud by introducing the water content of the mud containing water. In addition, it was confirmed that the mud and sand movement calculation according to the slope collapse of the mixed soil was stably performed through the calculation of the slope collapse of the mixed soil through the numerical analysis model to which the proposed mixed soil model was applied.

• Development and Reproduction
• /
• v.12 no.3
• /
• pp.267-274
• /
• 2008

Differentiation of blastocyst is critical step for implantation and is under the control of regulation factors originated from embryo or reproductive tracts. The sequential communication with those factors is suspected as critical events for differentiation. It has been suggested that intracellular signaling pathways activated by calcium is essential in differentiation of blastocyst. Previously, it was known that concanavalin A (Con A) increase the levels of free calcium in blastocyst stage. However, Con A can not accelerate the hatching, although heparin-binding epidermal growth factor-like growth factor (HB-EGF), a modulator of calcium level, accelerate the hatching of blastocyst. In this study, it was investigated whether Con A or prostaglandin $E_2$ ($PGE_2$) can modulate the differentiation of blastocyst. Con A accelerated the expansion of blastocyst in both 1 hr pulse treatment group and continuous treatment group. However, Con A significantly suppressed the hatching in both groups. The inhibition was significantly strong in continuous treatment group compared with 1 hr pulse treatment group. On the other hand, $PGE_2$ induced the increase the free calcium level, but did not accelerate the expansion. In addition $10{\mu}m\;PGE_2$ inhibited hatching. However, $PGE_2$ could accelerate hatching in Con A pretreated blastocyst. $PGE_2$ also caused the increase of free calcium level in Con A pretreated blastocyst. From these results, it is suggested that changes of the free calcium level induce a different calcium-mediated signaling pathways. In addition, sequential stimulation by signal molecules may triggers the cellular mechanisms for the differentiation of blastocyst.

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

• Development and Reproduction
• /
• v.14 no.2
• /
• pp.143-154
• /
• 2010

This article analyzes two leading Korean cases which led to opposite conclusions: the Boramae Hospital Case (Korean Supreme Court 2002 Do 995) and the Shinchon Severance Hospital Case (Korean Supreme Court 2009 Da 17471). In doing so, it pays particular attention to the acceptance, modification, and rejection of paternalism, specifically 'physician paternalism' and 'familial paternalism', both of which have long and strongly influenced the Korean medical environment. In Boramae Hospital, the Court emphasized the obligation of the physician in terms of the life of the patient (eg: protecting and preserving the life and welfare of the patient). Its position seemed to be based on the traditional physician paternalism which presupposes the ability of physicians to identify right and wrong choices according to natural laws. However, the Court saw itself as the final arbiter of who identifies and determines the real world content and consequences of that natural law. In short, the Court elevated itself to the supreme guardian of the patient, and held that its decision cannot be overruled by that of the patient's family. So without specifically referring to the importance of the family and the role of familial decisions, both long-observed traditions in medical decision-making in Korea, the Court shifted away from familial paternalism. In Shinchon Severance Hospital, the Court explained the meaning of the patient's powers of self-rulemore concretely, explaining its scope and substance in greater detail. The Court held that one can exercise the right of self-rule, even over issues such as death, in the form of 'previous medical directions'. However, this case does not represent a wholesale acceptance of medical autonomy (ie: it does not accept self-rule unconditionally). Rather, the Court accepted the importance of the opinions and decision of physicians and of the Hospital Ethics Commission, and the Court still retained to itself the authority to review and make alterations to 'material' decision. The Court did not overlook the importance of the decision of the patient's family, but it also did not relinquish its status as supreme guardian, emphasizing the 'objective' nature of a decision from the court.

• Development and Reproduction
• /
• v.14 no.4
• /
• pp.243-251
• /
• 2010

ESRRB (Estrogen related receptor $\beta$) is an orphan receptor, and have a role on maintaining the undifferentiated state and self-renewal of pluripotent stem cell as a transcription factor which regulates the expression of OCT4 and NANOG genes. Also, Feng et al. (2009) reported that Esrrb, Oct4 and Sox2 could induce pluripotent stem cell from somatic cells. The aim of the present study was to develop the direct delivery system of human ESRRB protein into human amniotic fluid-derived stem cells (AFSCs) and to analyze the effect of ESRRB on the regulation of pluripotency-related genes. Human ESRRB has three isoforms arisen by alternative splicing. We cloned short-form ESRRB and made a fusion protein of ESRRB and R7 for an efficient protein transfer to cell. R7 as cell-penetrating peptide(CPP) can help to transfer ESRRB into cells. R7-ESRRB-His6 protein was observed in the cytoplasm and nuclei within 5 hours after treatment. Also, we could observe R7-ESRRB-His6 protein only in the nuclei within 24 hours. Realtime PCR showed that ESRRB increased expression of OCT4 and NANOG as well as SOX2 gene. Therefore, we demonstrated that R7-ESRRB-His6 proteins were efficiently transferred into the nuclei of AFSCs and work well as a possible transcription factor.

• Development and Reproduction
• /
• v.13 no.4
• /
• pp.329-339
• /
• 2009

Cortisol is present in high concentration in the ovary and its receptor is expressed in the ovarian cells. Moreover, cortisol is known to have a role in steroid synthesis and cell metabolism in human granulosa and lutein cells. However, little is known of the role of cortisol presenting in high concentration in the follicles after LH surge on the granulosa-lutein cells. Therefore, the this study we evaluated the apoptosis and the production of progesterone $(P_4)$ and estradiol $(E_2)$ in the granulosa-lutein cells that are obtained during oocyte-retrieval after treatment with 5, 50, and $500{\mu}g/m\ell$ cortisol and 1 IU/$m\ell$ FSH. Results of DNA fragment analysis and TUNEL assay demonstrated that DNA fragmentation and the rate of apoptotic cells were increased in a dose-dependent manner showing a significant increase in 50 and $500{\mu}g/m\ell$ cortisol treated cells. We found, however, that FSH did not suppress the apoptosis of the cells induced by cortisol. In the results of chemiluminescence assay for $P_4$ and $E_2$, $P_4$ production was decreased by cortisol treatment, whereas $E_2$ was not changed. We also demonstrated that FSH did not inhibit the suppressive effect of GnRH on $P_4$ production as the result of apoptosis. The present study suggests that cortisol of high concentration could cause the apoptosis of human granulosa-lutein cells by suppressing the production of $P_4$. However, we need more studies to elucidate the mechanism by which cortisol induces apoptosis in human granulosa-lutein cells in view of the fact that our results are inconsistent with previous reported data.

• Korean Journal of Environmental Biology
• /
• v.32 no.2
• /
• pp.138-152
• /
• 2014

The objective of the study survey was to determine the effect of marine sand extraction on community composition and rate of recolonization of the meiobenthos following cessation of mining activities. Because of meiobenthic distribution in nature, high abundance, intimate association with sediments, fast reproduction, benthic larva period, sensitivity to pollution and rapid life histories, meiobenthos are widely regarded as ideal organisms to study the potential ecological indicator of natural and anthropogenic stresses. The community structure of meiobenthos was studied at seven stations within sandy tidal and sub tidal zones in Jangbongdo in the Yellow Sea, Korea from Aug. 2006 to Dec. 2007. Meiobenthic samples were collected by three core samples, with a 3.6 cm in diameter, from each sediment sample taken with a Smith-McIntyre Grab. It was found that sand mining often causes complete removal of the sediment and the damage to the habitats of meiobenthos. This study in the effect showed that sand mining resulted in a reduction in total abundance and biomass of meiobenthos in mining area. The finding of this study further showed that initial restoration of abundance and biomass within one year of the cessation of sand mining.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.1
• /
• pp.55-66
• /
• 2018

The cactus habitat in Jeju Island has a phytogeographically specific distribution in the East Asian region, and forms a unique landscape as the only native cactus (Opuntia ficus-indica (L.) Mill.) habitat in Korea. However, there has been no detailed investigation on the distribution of cacti in the habitat and no investigation on the diversity of the mixed composition of plants in the habitats and their correlation with the distribution of cactus populations. This study attempted to investigate the diversity of vascular plants in the Wollyeong-ri cactus habitat and record the actual distribution and trends of cactus distribution. In addition to the distribution characteristics of cacti, we also discuss the characteristics of species reflecting the characteristics of the habitat among the mixed population of plant species, as well as the biological and environmental factors that threaten the maintenance of cactus populations or require management for preservation of cacti. Considering the phenological character, we conducted the field surveys for flora identification six times between June 2015 and September 2017. The Engler classification system was used for the arrangement sequence and names of plants, and the Korean Plant Names Index was adopted for the Korean name of the species. The study results showed that the Wolryung-ri cactus habitat in Jeju Island has the characteristic physiognomy of an area dominated by cactus. For the vascular plants, a total of 125 taxa were identified, including 53 families, 104 genera, 109 species, 15 varieties and 1 forma. Endangered plants specified by the Ministry of Environment were not found. Two species, Cyrtomium falcatum and Asplenium incisum, were identified as the ferns, and no gymnosperms were found. In addition, 123 taxa of angiosperms, 91 taxa of dicotyledones and 32 taxa of monocotyledons were identified. The distributions of cacti were confirmed in 289 meshes corresponding to 59.3% of the total 487 meshes in the cactus protected area, which showed various coverage distributions ranging from 5% to 95%. Most of the meshes where no cacti were found are coastal areas with exposed basalt rocks where the soil depth has not developed or extremely restricted due to repeated waves, or areas where artificial facilities, grasslands, and observation paths have been constructed. On the other hand, there were 71 lattice points in 14.5% of the total area where the cactus showed 70% or higher dominance. Cacti are randomly distributed in these areas. They have adapted to the microhabitat environment and are found to be opportunistically distributed along the growable locations. Considering that the reproduction of cacti in the habitat is mostly dependent on parthenogenesis, the present distribution seems to reflect the potentially distributable regions of cacti in the habitat. Based on the results of field surveys, a management plan for conservation and protection of the protected areas has been proposed.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.4
• /
• pp.94-104
• /
• 2018

This study examined photogrammetric reconstruction techniques that can measure the original form of a cultural property utilizing photographs taken in the past. During the research process, photographs taken in the past as well as photograph on the internet of Soswaewon Garden in Damyang(scenic site 40) were collected and utilized. The landscaping structures of Maedae, Aiyangdan, Ogokmun Wall, and Yakjak and natural scenery Gwangseok, of which photographs can be taken from any 360 degree direction from a close distance or a far distance without any barriers in the way, were selected and tested for the possibility of reproducing three-dimensional shapes. The photography method of 151 landscape photographs (58.6%) from internet portal sites for the aforementioned five landscape subjects containing information on the date the photograph was taken, focal length, and exposure were analyzed. As a result of the analysis, it was revealed that the majority of the photographs tend to focus on important parts of each subject. In addition, we discovered that there are two or three photography methods that internet users preferred in regards to each landscape subject. For the purposes of the experiment, photographs in which a single scene consistently appears for each landscape subject and it was determined that there was a high level of preference related to the photography method were analyzed, and three-dimensional mesh shape model was produced with a photoscan program to analyze the reproducibility of three-dimensional shapes. Based on the results of the reproduction, it was relatively possible to reproduce three-dimensional shapes for artifacts such as Ogukmun wall, Maedae, and Aeyangdan, but it was impossible to reproduce three-dimensional images for natural scenery or an object that has similar texture such as Yakjak and Gwangseok. As a result of experimentation related to the reconstruction of three-dimensional shapes with the photographs taken on site using a photography method similar to that of the photographs selected as previously mentioned, there was success related to reproducing the three-dimensional shapes of Yakjak and Gwangseok, of which it was not possible to do so through the photographs that had been collected previously. In addition, through comparison of past and present images, it was possible to measure the exact sizes as well as discover any changes that have taken place. If past photographs taken by tourists or landscape architects of cultural properties can be obtained, the three-dimensional shapes from a particular period of time can be reproduced. If this technology becomes widespread, it will increase the level of accuracy and reliability in regards to measuring the past shapes of cultural landscape properties and examining any changes to the properties.

• Development and Reproduction
• /
• v.12 no.3
• /
• pp.251-259
• /
• 2008

The plasticizer di(2-ethylhexyl)phthalate(DEHP) is one of the most well known endocrine disrupting chemicals (EDCs) because of its strong anti-androgenic effects on the reproductive and developmental process in male rodents and human. The present study was performed to examine whether prepubertal exposure to DEHP can make any alteration during the maturation of accessory sex organs in male rats. As a result, there was no significant change in body weights, serum T levels and tissue weights except of seminal vesicle and ventral prostate in DEHP-treated animals compared to vehicle-treated ones. The seminal vesicle weights in high-dose group (200 mg/kg) were significantly lower than those from the control group (p<0.05), and ventral prostate weights were significantly lower than those from the control group (p<0.05) in both low-dose (20 mg/kg) and high-dose group. Histological studies revealed that the seminal vesicles from DEHP-treated groups showed reduced areas of mucosal folds. Pseudostratified columnar epithelia were observed in the ventral prostates of DEHP-treated samples while cuboidal epithelia were found in the control group. The transcriptional activities of ER-$\alpha$ in seminal vesicle from high-dose group (p<0.05) were significantly higher than those from the control group, and ER-$\beta$ expression was significantly decreased in low-dose group (p<0.05) compared to the control. In ventral prostate, ER-$\beta$ mRNA levels from low-dose group (p<0.05) were significantly lower than those from the control group, and significantly increased in high-dose group (p<0.01). AR expressions, however, were not significantly different in all experimental groups of both seminal vesicle and ventral prostate. In conclusion, the present study demonstrated that (i) adverse effect (s) of DEHP on sexual maturation during prepubertal period could be limited, (ii) seminal vesicle and prostate gland were sensitive targets to DEHP in prepubertal rats and (iii) the deleterious effects of DEHP might be mediated through ER-associated mechanism.