• Journal of Aquaculture
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• v.20 no.3
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• pp.199-202
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• 2007

We isolated a 317 bp of partial cDNA for doublesex-and mab-3-related transcription factor-1 (DMRT-1) from the testis of olive flounder, Paralichthys olivaceus using RT-PCR. Based on the multiple sequence alignment, olive flounder DMRT-1 shared relatively high sequence homology (82 to 94%) with orthologues from other teleost species such as Atlantic halibut, Hippoglossus hippoglossus, black porgy, Acanthopagrus schlegeli and rainbow trout, Oncorhynchus mykiss. DMRT-1 mRNA was predominantly expressed in the testis of olive flounder. In our investigation for the effect of testosterone treatment in vivo on induced expression of ovarian DMRT-1 transcript, mRNA levels of DMRT-1 in ovary were significantly up-regulated by testosterone treatments (0.3 or $3.0{\mu}g$ testosterone/g body weight for 12 to 36 hours) as judged by RT-PCR analysis. In overall, transcriptional stimulation of DMRT-1 during treatments was more affected by doses of testosterone than treatment durations. This result strongly suggests that the regulation of DMRT-1 be tissue- and gender-specific in olive flounder, and also provides useful baseline knowledge on the testosterone-mediated regulation in the reproductive physiology of this species.

• Journal of Aquaculture
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• v.21 no.2
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• pp.63-69
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• 2008

We isolated complementary DNA(cDNA) encoding prolactin receptor(PRLR) from gill of black porgy Acanthopagrus schlegeli. Its PRLR cDNA consists of 1,611 base pairs and encodes the protein of 536 amino acids. To investigate the osmoregulatory abilities of black porgy in different salinities(35, 10 and 0 psu), we examined the expression of PRLR mRNA in osmoregulatory organs(gill, kidney and intestine) using reverse transcription(RT)-PCR. In gill and intestine, PRLR mRNA levels were high in 10 psu, and then decreased in 0 psu, but there is no changes in kidney. Also, plasma osmolality, $Na^+\;and\;Cl^-$ levels decreased during the experimental period. These results suggest that PRLR plays an important role in hormonal regulation in osmoregulatory organs during freshwater acclimation, thereby improving the hyper-osmoregulatory ability of black porgy in hypoosmotic environments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.2
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• pp.67-73
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• 2007

A respiration rate analysed by enzyme kinetics-based respiration model and gas permeability data of LDPE film were applied to design the optical modified atmosphere (MA) packaging condition of persimmon (Diospyros kaki cv. Fuyu) fruits. The fruit quality rapidly decreases due to physiology disorder such as softening and peel blackening. $O_2$ permeance ($Q_{O2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) and $CO_2$ performance ($Q_{CO2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) of low density polyethylene (LDPE) film samples were measured at $0^{\circ}C$ and described as function of thickness (L in ${\mu}m$) as $Q_{O2}=(2540{\times}1/L)-16$, and $Q_{CO2}=(13742{\times}1/L)-70$, respectively. MA package containing single persimmon fruit of 225g was designed and tested experimentally at $0^{\circ}C$ by using LDPE films. Package atmospheres predicted from the relationship of $O_2$, $CO_2$ and $N_2$ balances on the packages was in good agreement with those obtained experimentally. Physiology disorder occurrence was the lowest at 52 ${\mu}m$ package that attained optimum gas condition ($O_2$ 2.8% and $CO_2$ 5.4%). The computer simulation was found to be effective to help to design the optimum MA packaging condition of individual persimmon fruit.

• Korean Journal of Ichthyology
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• v.22 no.1
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• pp.1-8
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• 2010

We determined oxidative stress caused by thermal stress in olive flounder Paralichthys olivaceus based on the altered-mRNA expression and enzymatic activity of two key antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), along with monitoring of several other biomarkers. When the fish were exposed to acute thermal change (from $20^{\circ}C$ to $25^{\circ}C$ and $30^{\circ}C$), the expression and activity of both enzymes were significantly higher at elevated temperatures ($25^{\circ}C$ and $30^{\circ}C$) than at $20^{\circ}C$. Lipid peroxidation (LPO) was also higher at $25^{\circ}C$ and $30^{\circ}C$ than at $20^{\circ}C$. In addition, the plasma $H_2O_2$ concentration was significantly increased by thermal stress. Furthermore, we investigated changes due to thermal stress by measuring levels of plasma alanine aminotransferase (AlaAT) and aspartate aminotrasferase (AspAT). Both were significantly increased by thermal stress. As an immune indicator, the lysozyme concentration was lower at $30^{\circ}C$ than at $20^{\circ}C$, indicating that thermal stress decreases immune function. Therefore, thermal stress could induce oxidative stress and suppress immune function and can cause physiological stress.

• Korean Journal of Ichthyology
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• v.22 no.1
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• pp.17-24
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• 2010

The present study investigated the expression of glucocorticoid receptor (GR) mRNA as a stress response during salinity changes (35, 10, and 0 psu) and water temperature changes (from $20^{\circ}C$ to $30^{\circ}C$, $1^{\circ}C$/day) in black porgy. We cloned the full-length GR cDNA from the kidney and examined its expression in the gill, kidney, and intestine by quantitative real-time PCR (QPCR) during salinity and water temperature changes. During salinity changes, the levels of GR mRNA in the gill, kidney, and intestine were highest at 0 psu, and the levels of plasma cortisol and glucose were elevated, but triiodothyronine ($T_3$) decreased. Also, during water temperature changes, the levels of GR mRNA in the gill, kidney, and intestine increased at $30^{\circ}C$. Plasma parameters also increased with an increase in water temperature. Therefore, this upregulation of GR mRNA was a good indicator of stress, such as those resulting from changes in salinity and water temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.16 no.2_3
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• pp.53-58
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• 2010

Internal gas composition of single unit persimmon package was evaluated at $-1^{\circ}C$ as function of package film area and fruit weight in order to find packaging conditions to achieve the optimal modified atmosphere beneficial for keeping the freshness. With large fruit size(${\approx}230\;g$), low permeable films (LLDPE/PP in 35 or $40\;{\mu}m$ thickness and $30\;{\mu}m$ OPP) with an exact fitness to the fruit (surface area of $0.040\;m^2$) resulted in anaerobic atmosphere with occurrence of browning in long term storage. With medium (${\approx}210\;g$) and medium small (${\approx}190g$) sizes, larger surface area of low permeable $35\;{\mu}m$ LLDPE/PP film provided higher $O_2$ and lower $CO_2$ concentrations causing higher occurrence of softening and blackening discoloration. On the other hand, smaller surface area of lower $O_2$ and higher $CO_2$ concentrations had a high risk of browning. Wise combination of fruit size, packaging film and surface area is required for attaining the beneficial modified atmosphere to prevent the physiological injuries.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.192-202
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• 2007

Objectives: The objectives of this research are to examine the missions, organization, and programs of the environmental, health and safety(EHS) offices of the major research universities in the U.S.A., particularly the case of Massachusetts Institute of Technology(MIT) EHS Office, and to suggest ways to address the EHS issues of the universities and research institutes in South Korea. Methods: The top 30 research universities in the U.S.A. were selected by the total amounts of research funds they annually received. The web sites of the 30 universities were searched to identify the names of the departments that address environment, health, and/or safety related issues, the missions of those departments, the major programs of those departments, and the number of staff in those departments. Also, a case study was conducted for the Environment Health and Safety Management System and the Environment, Health and Safety Office of the MIT, using literature and web searches and a meeting with the Director of the MIT Environment, Health and Safety Office. Results: All the top 30 research universities in the U.S.A. had designated departments that dealt with EHS issues. Most of them were by the name of or similar to environmental, health and safety. The mission statements of those departments were mostly about improving the safety and health of their community members, improving the environment, and complying to EHS regulations. Most of those departments had an environmental management program, industrial hygiene program, radiation protection program, safety program, and biosafety program as their major programs. The components of the environment, health and safety management system(EHS-MS) of the MIT were examined in detail. In contrast, not many universities in South Korea had designated departments that dealt specifically with EHS issues. Also, the number of fulltime staff for EHS was only 1-2 in most of the Korean universities and their work duties included only general safety, while neglecting other health/environment related issues. Conclusions: Well organized and functioning environmental, health and safety offices were present in all of the top 30 research universities in the U.S.A., whereas similar organizations of the universities in South Korea were virtually non-existent and/or had very limited EHS activities. Therefore, in order to reduce potential risks of accidents and health problems in the Korean universities and research institutions, well established and functioning EHS-MSs and EHS offices are warranted. The case of the EHS-MS and EHS Office in the MIT demonstrate a successful case to follow.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.15 no.2
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• pp.43-47
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• 2009

Respiration and quality of persimmon fruits were monitored through the storage at 0, 5, 15 and $25^{\circ}C$. Respiration rate data at different temperatures were used for determining the $O_2$ and $CO_2$ permeabilities required to maintain the optimal package atmosphere (1~3% $O_2$, 4~7% $CO_2$). The estimated gas permeabilities were then compared to those of available plastic films for examining their potential application at various temperature conditions. $O_2$ consumption and $CO_2$ production were at similar order and leveled at stable value after initial time span with higher rates measured at higher temperatures. Major quality indexes during storage were observed to be ascorbic acid content change and firmness destruction with the most significant changes at $25^{\circ}C$ Higher $O_2$ and $CO_2$ permeabilites were required at higher temperatures, and common plastic films were shown to be unable to satisfy those requirements. Films or devices of high permeation property such as silicone rubber or microporous film may be combined to increase the permeation properties satisfying the required high gas permeabilities.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.757-767
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• 2006

Biological assessments are the primary tool for evaluating the biological condition of a water body and makes it possible to understand accumulative and long-term effect of stressors. They also provide reliable biological information for which disturbed systems are to be restored. Sustainable water environment is not enough with attaining only the clean water, but it should sustain healthy and diverse aquatic life. Aquatic organisms are affected by various factors, including not only water quality but also habitat condition and stressors, and thus good condition of both physical and chemical water quality is prerequisite for sustaining healthy organisms. Therefore, biological assessment, along with other physical and chemical assessments, are crucial for evaluating the health of a water body. Overall, sustainability of water environment demands the attainment and maintenance of ecological integrity, which is resulted from the combination of physical, chemical and biological integrity. The biological criteria will play very important role in the water resource management and policy issues, and thus bioassessment program should be fully implemented and supported eventually by the law. To keep ecosystem health of water environment safely from the toxic pollutants and other stressors, the following suggestions need to be considered in environmental quality standards in Korea. For the first step, the biological indicators need to be introduced in evaluating river quality condition; they provide a qualitative description of biological condition of water body. Secondly, the biological water quality standards using biotic indices should be developed and implemented under the consideration of characteristics of Korean river systems. Lastly, the ecological status classification regime (ESCR) should be developed and introduced; it could be used in quality assessment of the water environment in general. In developing ESCR, integration of physico-chemical, biological, and habitat parameters should be taken into account.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.217-227
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• 2007

The western cherry fruit fly, Rhagoletis indifferens Curran (Diptera:Tephritidae), is the most important pest of cultivated cherries in the Pacific Northwest area of the United States, being widely distributed throughout Oregon, Washington, Montana, Utah, Idaho, Colorado and parts of Nevada. The control of R. indifferens has been based on calendar sprays after its first emergence because of their zero tolerance for quarantine. Therefore, a good prediction model is needed for the spray timing. This study was conducted to obtain the empirical population dynamic information of R. indifferens after overwintering in the major cherry growing area of the Pacific Northwest of the United States, where the information is critically needed to develop and validate the prediction model of the fruit fly. Adult fly populations were monitored by using yellow sticky and emergence traps. Larvae growth and density in fruits were observed by fruit sampling and the pupal growth and density were monitored by pupal collection traps. The first adult was emerged around mid May and a large number of adults were caught in early June. A fruit had more than one larva from mid June to early July. A large number of pupae were caught in early July. The pupae were collected in various period of time to determine the effect of pupation timing and the soil moisture content during the winter. A series of population density data collected in each of the developmental stage were analyzed and organized to provide more reliable validation information for the population dynamic models.