• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.144-150
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• 2003

Reproductive biology and population dynamics of Latreutes planirostris were investigated on the south western waters of Korea from June 2001 to May 2002. This paper describes sex ratio, population growth, and reproductive aspects of Latreutes planirostris. Brood size was an isometric function of female carapace length. Based on dry weight, reproduction effort (mass of eggs/mass of female) averaged 0.23. Ovarian examination showed that there was significantly higher gonadosomatic index from May to September, with a peak in June. Statistical analysis revealed that the ovarian dry weight of females with eyed eggs was significantly higher than that of those with non-eyed eggs. This suggests that females were potentially consecutive breeders. Sex ratio showed that female is more numerous than male. Growth parameters mortality and recruitment were estimated by monthly length-frequency data. Growth parameters were estimated, using the seasonalized von Bertalanffy growth function model $(L\infty\;=\;12.70\;mm\;CL,\;K\;=\;0.87yr^{-1},\;C\;=\;0.96,\;WP\;=\;0.59)$. The recruitment pattern was twice a year.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.1
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• pp.24-30
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• 2007

We developed an ecosystem indicator (EI) for the coastal and offshore areas of Korean waters. One of the major scientific challenges of this undertaking was to translate broad policy statements for ecosystem-based fisheries management (EBFM) into practical terms. Fish reproduction potential (FRP) was defined as an EI to describe the reproductive probability of adult fisheries resources in Korean waters. The FRP was estimated as the ratio of adult fish composition to total catch, catches (in metric tons) by species and by ecosystem, and fishery effort (in horse power per metric ton). The FRP indices of the East/japan Sea Ecosystem (EJSE), Yellow Sea Ecosystem (YSE), and East China Sea Ecosystem (ECSE) began to decrease after the mid-1980s, and the current indices have decreased further, at 0.63 (EJSE), 1.22 (YSE), and 0.68 (ECSE) index points compared to the indices of 1975, when similar catch amounts were recorded. Lower FRPs in the Korean marine ecosystems were the result of higher proportion of immature fisheries resources in the total catch. Because this kind of ecosystem-level indicator is thought to reflect scientific approaches to EBFM and to provide an important tool for assessing the current status of marine ecosystems with respect to both quantity and quality, more EIs should be developed for Korean waters.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.1-14
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• 2013

A species restoration plan requires a process where the first is to thoroughly study the target species, second is to provide them with an onsite reproduction and adaptation period, and finally, third is to release them to their natural habitat. This study focuses on the space planning for target species' successful onsite reproduction and adaptation. For the study, a site planning near Sobaeksan National Park was implemented with Red Fox's behavior and habitat characteristics in mind for its recovery, reproduction, and natural adaptation. During site selection and planning, the basic aim was to incorporate the existing site as much as possible thus reducing the impact on the environment from the recovery plan. In addition, for a stable recovery of the Red Fox population, the site was classified into three different areas : core area, buffer zone, and transition area. Then, the facilities that help Red Fox's reproduction and adaptation such as reproduction center, foraging site, adaptation training center were planned. Under the condition that the site will be off limit to the public, a limited number of paths for monitoring was provided. For the site's vegetation, the existing species were planted as much as possible with the addition of plants that the Red Fox consume. The facilities included as Red Fox's habitat were fox burrows for hiding and ecological ponds for drinking. From this study, the recovery of the endangered fox species is expected as well as the contribution to an effort to increase of awareness toward the biological resources in Korea through Nagoya protocol. Furthermore, it has the potential to change the public's attitude toward endangered species recovery projects through publicizing and providing experience to the national park visitors.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.258-264
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• 2000

Production systems for cloned pigs are very important not only for an increase in production of superior animals but also for the production of knockout animals with organs that do not contain antigens for xenotransplantation or to analyze functions of isolated human genes. At present, however, effective systems have not been developed. We have tried to produce cloned pigs by transfering cultured cells into enucleated oocytes and obtained some cloned embryos. To develop a production system for cloned pigs, the basic technologies needed to support such an effort must be improved.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.85-85
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• 2002

As an effort to direct differentiation of human embryonic stem cells (hES, MB03) to dopamine-producing neuronal cells, we expressed Nurr-l in hES and examined the expression of tyrosine hydroxylase (TH) after bFGF induction. To introduce Nurr-l, hES cells were maintained in humidified chamber with 5% CO₂ and 95% air in DMEM/Fl2 supplemented with FBS (10%), penicillin (100U/㎖), and streptomycin (100㎍/㎖). (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.964-969
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• 2006

The soundscape is a novel attempt to offer comfortable sound environments at the urban public spaces by adding pleasant sounds and removing unagreeable ones. Most important factors to be considered therein are to determine what kind of sounds to offer and how to adjust them to the changing circumstances. But nowadays, the audio system provided in the almost every urban public spaces is just only a PA system with CD player or radio broadcasting music, the provided sound is only intended by the operator. Furthermore, providing the soundscape which fits to the situation and the atmospheric conditions needs enormous effort and time, it is almost impossible with the existing PA systems which installed in the public spaces nowadays. Thus, the new sounds cape reproduction system was developed on the basis of the prior VAFSS(Virtual Acoustic Field Simulation System) systems, which has the artificial intelligence to read out the mood of the field and select the appropriate soundscape to reproduce. In this new system, various environmental sensors with standard voltage, current or resistance output are available simultaneously, and the monitoring with video and sound became available via the TCP/IP communication protocol. The update and control of this system can be very convenient, so the money, time and the effort of maintaining and providing soundscape on the public spaces can be enormously saved. This new soundscape reproducing system was named as Virtual Acoustic Field Simulation System II (V AFSS II).

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.355-362
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• 1997

This study was undertaken in an effort to product embryos through in vitro maturation(IVM), in vitro fertilization(IVF) and in vitro culture(IVC) after cryopreservation of immature and mature porcine oocytes. The experiments were conducted to investigate IVM rate of oocytes frozen with 3 different cryoprotectants and to examine IVF and IVC of frozen-thawed oocytes. The CEI(cumulus cells expansion index) after IVM of frozen-thawed immature oocytes was higher in oocytes frozen with PG＋PEG(propylene glycol plus polyethylene glycol) than those frozen with single cryoprotectant and this index was almost 90% of unfrozen oocyte's index(2.39 vs. 2.66). The IVF rate of all frozen oocytes was very low(68% of unfrozen oocytes) and the IVF rate of frozen immature oocytes was slightly higher than that of frozen mature oocytes(39.0% vs. 34.4%), but polyspermic penetration was higher in frozen immature oocytes(21.9% vs. 19.1%). The cleavage rate after IVF of frozen-thawed oocytes was 9.3% for frozen mature oocytes and 11.3% for frozen immature oocytes and this rate was significantly lower(P<0.05) than that of control(60.7%). The development to 8-cell stage was greatly lower in frozen mature oocytes than in frozen immature oocytes. The results indicate that the use of PG plus PEG as cryoprotectant may be very effective for vitrification of porcine oocytes and the frozen-thawed immature porcine oocytes can be used fro in vitro embryo production based on IVM, IVF and IVC system.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.9-15
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• 2008

Growth and reproduction of Palaemon serrifer were described and analyzed in a population inhabiting tide pools in warm temperate waters in Korea. The water temperature varied greatly in the tide pools, ranging from 8$^{\circ}C$ to 27.8$^{\circ}C$ Population structure and growth were investigated using size frequency distribution data collected from January to December 2003. Sex ratios fluctuated, but were almost equal during the breeding period. Growth was continuous and size increased gradually throughout the year. Adult females were larger and grew faster than males. von Bertalanffy growth parameters for a one-year sample of females and males were estimated as $L_{i\ddot{A}}$ = 11.32, K = 0.311, $t_0$ = -0.4115 and $L_{i\ddot{A}}$ = 8.36, K = 0.228, $t_0$ = -0.9693 respectively. Breeding was seasonal, starting in May, peaking in August, and finishing by the end of August. The species showed continuous production of successive broods. Laboratory observation showed that females with embryos near hatching had ovaries filled with vitellogenic oocytes ready for spawning. The reproductive output (effort) of each female (mean number of eggs: $552{\sim}1355$) was not high. The mean embryo volume, $0.078mm^3$, is relatively small, indicative of low energy allocation to each embryo. Recruitment of juveniles was closely linked to the breeding period, beginning in September.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.1-6
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• 2006

Abstract - Global decline in wildlife mammals has been accelerated during past decades. Especially the conservation the wild life mammals in polar areas, is urgent. In an effort to understand the reproduction of the seals dwelling in the polar area, spermatogenesis in the seals was reviewed. Seals breed seasonally and in most of the seal species, delayed implantation is frequently observed. To date, histological and endocrinological evaluation revealed highly cyclic nature in supermatogenesis and steroidogenesis in testis. Seasonal changes in blood testosterone level together with melatonin is closely related with changes in light cycle between summer and winter. In adult testis at breeding seasons, spermatogenesis is manifested by consecutive 18 stages of germ cell development. Three kinds of Leydig cells different in steroidogenic activity as well as cellular morphology appear during the testis development. During non-breeding season, spermatogenic arrest and Leydig cell hypoplasia are frequently found. Interestingly, blood circulation through the anastomoses of pelvic veins cooled the testes and thus guarantees spermatogenesis within the body trunk. Endocrine disruptors and heavy metals have been found in the body tissues of several seals species and alter steroidogenesis in seals, suggesting environmental pollutants together with decrease in habitats are potentially threatening the reproductive success in seal species.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.272-272
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• 2004

The objective of this study is to test whether human embryonic stem cells expressing Nurr1 (Nurr1-transfected hES cells) could be expressed TH according to neuronal differentiation. As an effort to direct differentiation of hES (MB03 registered in NIH) cells to dopamine-producing neuronal cells, Nurr1 was transfected using conventional transfection protocol into MB03 cell and examined the expression of tyrosine hydroxylase (TH) after differentiation induced by retinoic acid (RA) and ascorbic acid (AA). (omitted)