• Journal of Life Science
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• v.34 no.2
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• pp.122-127
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• 2024

This study investigated the reproductive ecology and spawning of Hoplobrotula armata on the coast of Jejudo Island. Samples were collected from February to December 2019 and February to December 2020, with a total of 2,634 samples. The results of the investigation showed that total length (TL) ranged from 22.0 cm to 68.8 cm, and the body weight (BW) ranged from 66.5 g to 3,553.9 g. According to the development process of gonads and the gonadosomatic index (GSI), the spawning period of H. armata was from July to October. The relationship between TL and BW was BW = 0.0024TL^3.3278 in females and BW = 0.0035TL^3.2162 in males. The sex ratios of surveyed female to male H. armata was 1:0.71, with more females. At 50%, 75%, and 97.5%, the group maturities of H. armata were as follows: Females, 39.9 cm, 42.7 cm, and 49.4 cm; males, 37.6 cm, 40.4 cm, and 46.9 cm, respectively. According to monthly GSI and gametocyte (ovarian, testis) development stage observations of H. armata on the coast of Jejudo Island, they spawn once a year and are presumed to be summer spawners.

• Journal of Korean Society of Forest Science
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• v.29 no.1
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• pp.20-53
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• 1976

For the purpose of detecting the capability of the trees to resist air pollution and of determining the tree species best suited for purification of polluted air, particularly with regard to $SO_2$ contamination, six following ornamental tree species were selected as experimental materials: i.e., Hibiscus syriacus L., Ginkgo biloba L., Forsythia koreana Nak., Syringa dilatata Nak., Larix leptolepis Gordon, and Pinus rigida Miller. The susceptiblities of the trees were observed and analyzed on the basis of area ratio of smoke injury spots to the total leaf area. The results of the experiments are as follows: I. The Susceptibilities to Sulfur Dioxide. (1) The decreasing order of tolerance to $SO_2$ by species was as follows: 1. Hibiscus syriacus 2. Ginkgo biloba, 3. Forsythia koreana, 4. Syringa dilatata, 5. Larix leptolepis, and 6. Pinus rigida. In general, Hibiscus syriacus and Ginkgo biloba can be grouped as the most resistant and Larix leptolepis and Pinus rigida as the least resistant and Forsythia koreana and Syringa dilatata as of intermediate resistance. (2) The sulfur content of the leaves treated by $SO_2$ increased in proportion to the increase of the concentration of the fumigation. The content in the coniferous species proved to be less than that of the broad-leaved species, but Ginkgo biloba proved to contain as much sulfur as broad-leaved species. (3) The earlier-stage leaves fumigated in June with the $SO_2$ concentration up-to-l-ppm showed that sulfur content increases in proportion to the increase of the concentration of the fumigation, but the difference between concentration was not so significant. (4) The later-stage leaves fumigated in October showed higher sulfur content than the earlier stage leaves, and a wider range of difference in sulfur content was detected among different concentrations. The limit of fumigation resulting in culmination of sulfur absoption in broad-leaved species, such as Syringa dilatata, Hibiscus syriacus, and Forsythia koreana proved to be around 0.6 ppm. (5) Due to the sprouting ability and the adventitious bud formation, the recovery from $SO_2$ fumigation was prominent in Hibiscus syriacus, Syringa dilatata, and Forsythia koreana. (6) The differences in the smoke spot color were recognized by species: namely, dirt-brown in Syringa dilatata, brilliant yellowish-brown in Pinus rigida and Ginkgo biloba, whitish-yellow in Hibiscus syriacus and reddish-brown in Forsythia koreana. (7) The leaf margins proved to be most susceptible, and the leaf bases of the mid-rib most tolerant. In both Ginkgo biloba and Larix leptolepis, the younger leaves were more resistant to $SO_2$ than the older ones. II. The ulfur Content of the Leaves of the Ornamental Trees Growing in the City of Seoul. (1) The sulfur contents in the leaves of the Seoul City ornamental trees showed a remarkably higher value than those of the leaves in the non-polluted areas. The sulfur content of the leaves in the non-polluted area proved to be in the following descending order: Salix pseudo-lasiogyne Leveille, Ginkgo biloba L., Alianthus altissima swingle, Platanus orientalis L., and Populus deltoides Marsh. (2) In respect to the sulfur contents in the leaves of the ornamental trees in the city of Seoul, the air pollution proved to be the worst in the areas of Seoul Railroad Station, the Ahyun Pass, and the Entrance to Ewha Womans University. The areas of Deogsu Palace, Gyeongbog Palace, Changdeog Palace, Changgyeong Park and the Hyehwa Intersection were least polluted, and the areas of the East Gate, the Ulchi Intersection and the Seodaemun Intersection are in the intermediate state.

• Tuberculosis and Respiratory Diseases
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• v.63 no.3
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• pp.242-250
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• 2007

Background: Abnormal angiogenesis can induce hypoxia within a highly proliferating tumor mass, and these hypoxic conditions can in turn create clinical problems, such as resistance to chemotherapy. However, the mechanism by which hypoxia induces these changes has not yet been determined. Therefore, this study was conducted to determine how hypoxia induces changes in cell viability and extracellular microenvironments in an in vitro culture system using non-small cell lung cancer cells. Methods: The non-small cell lung cancer cell line, A549 was cultured in DMEM or RPMI-1640 media that contained fetal bovine serum. A decrease in the oxygen tension of the media that contained the culture was then induced in a hypoxia microchamber using a $CO_2-N_2$ gas mixture. A gas analysis and an MTT assay were then conducted. Results: (1) The decrease in oxygen tension was checked the anaerobic gas mixture for 30 min and then reoxygenation was induced by adding a 5% $CO_2-room$ air gas mixture to the chamber. (2) Purging with the anaerobic gas mixture was found to decrease the further oxygen tension of cell culture media. (3) The low oxygen tension resulted in a low pH, lactic acidosis and a decreased glucose concentration in the media. (4) The decrease in glucose concentration that was observed as a result of hypoxia was markedly different when different types of media were evaluated. (5) The decrease in oxygen tension inhibited proliferation of A549 cells. Conclusion: These data suggests that tumor hypoxia is associated with acidosis and hypoglycemia, which have been implicated in the development of resistance to chemotherapy and radiotherapy.

• Atmosphere
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• v.20 no.4
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• pp.467-482
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• 2010

In this study, characteristics of various stability indexes (SI) and environmental parameters (EP) for the lightning are analysed by using 5 upper air observatories (Osan, Gwangju, Jeju, Pohang, and Baengnyeongdo) for the years 2002-2006 over South Korea. The analysed SI and EP are the lifted index, K-index, Showalter stability index, total precipitable water, mixing ratio, wind shear and temperature of lifting condensation level. The lightning data occurred on the range of -2 hr~+1 hr and within 100 km based on the launch time of rawinsonde and observing location are selected. In general, summer averaged temperature and mixing ratio of lower troposphere for the lightning cases are higher about 1 K and $1{\sim}2gkg^{-1}$ than no lightning cases, respectively. The Box-Whisker plot shows that the range of various SI and EP values for lightning and no lightning cases are well separated but overlapping of SI and EP values between lightning and no lightning are not a little. The optimized threshold values for the detection of lightning are determined objectively based on the highest Heidke skill socre (HSS), which is the most favorable validation parameter for the rare event, such as lightning, by using the simulation of SI and EP threshold values. Although the HSS is not high (0.15~0.30) and the number and values of selected SI and EP are dependent on geographic location, the new threshold values can be used as a supplementary tool for the detection or forecast of lightning over South Korea.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.206-211
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• 2006

This study was performed to examine antitumor activities of Rubus coreanus Miquel and Angelica gigas Nakai extracts against sarcoma-180 and anti-stress activities in ICR mice. The variation of body weights of the 20 days of Rubus coreanus extracts-administrated mice group was very low. The survival rate (T/C %) of Rubus coreanus extract administrated group was 161% after 50 days from the inoculation of sarcoma-180 and the increment of their body weights was suppressed. Anti-stress effect of the extracts of R. coreanus and A. gigas were estimated by maeasuring blood chemical value and internal organs weight in ICR mice. The extracts of R. coreanus reduced the cholesterol and glucose to the normal level in the all stress animal models. The extracts of R. coreanus reduced the hypertrophy of the internal organs such as adrenal, spleen and liver to the regular level.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.318-327
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• 2012

BACKGROUND: For Non-Point Source(NPS) loads reduction, pollutant loads need to be quantified for major farming methods. The objective of this study was to evaluate impacts of farming methods on NPS pollutant loads from a paddy rice field during the growing season. METHODS AND RESULTS: The height of drainage outlet, amount of fertilizer, irrigation water quality were considered as farming factors for scenarios development. The control was derived from conventional farming methods and four different scenarios were developed based combination of farming factors. A field scale model, CREAMS-PADDY(Chemicals, Runoff, and Erosion from Agricultural Management Systems for PADDY), was used to calculate pollutant nutrient loads. The data collected from an experimental plot located downstream of the Idong reservoir were used for model calibration and validation. The simulation results agreed well with observed values during the calibration and validation periods. The calibrated model was used to evaluate farming scenarios in terms of NPS loads. Pollutant loads for T-N, T-P were reduced by 5~62%, 8~37% with increasing the height of drainage outlet from 100 mm of 100 mm, respectively. When amount of fertilizer was changed from standard to conventional, T-N, T-P pollutant loads were reduced by 0~22%, 0~24%. Irrigation water quality below water criteria IV of reservoir increased T-N of 9~65%, T-P of 9~47% in comparison with conventional. CONCLUSION(S): The results indicated that applying increased the height of drainage after midsummer drainage, standard fertilization level during non-rainy seasons, irrigation water quality below water criteria IV of reservoir were effective farming methods to reduce NPS pollutant loads from paddy in Korea.

• The Transactions of the Korea Information Processing Society
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• v.1 no.3
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• pp.367-379
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• 1994

This paper describes scheduling algorithms of the UNIX operating system and shows an analytical approach to approximate the average conditional response time for a process in the UNIX operating system. The average conditional response time is the average time between the submittal of a process requiring a certain amount of the CPU time and the completion of the process. The process scheduling algorithms in thr UNIX system are based on the priority service disciplines. That is, the behavior of a process is governed by the UNIX process schuduling algorithms that (ⅰ) the time-shared computer usage is obtained by allotting each request a quantum until it completes its required CPU time, (ⅱ) the nonpreemptive switching in system mode and the preemptive switching in user mode are applied to determine the quantum, (ⅲ) the first-come-first-serve discipline is applied within the same priority level, and (ⅳ) after completing an allotted quantum the process is placed at the end of either the runnable queue corresponding to its priority or the disk queue where it sleeps. These process scheduling algorithms create the round-robin effect in user mode. Using the round-robin effect and the preemptive switching, we approximate a process delay in user mode. Using the nonpreemptive switching, we approximate a process delay in system mode. We also consider a process delay due to the disk input and output operations. The average conditional response time is then obtained by approximating the total process delay. The results show an excellent response time for the processes requiring system time at the expense of the processes requiring user time.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.21-33
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• 2021

The purpose of this study is to determine the order of priority for the use of amendments, matching the optimal amendment to the specific site in Korea. This decision-making process must prioritize the stabilization and economic efficiency of amendment for heavy metals and metalloid based on domestic site contamination scenarios. For this study, total 5 domestic heavy metal contaminated sites were selected based on different pollution scenarios and 13 amendments, which were previously studied as the soil stabilizer. Batch extraction experiments were performed to quantify the stabilization efficiency for 8 heavy metals (including As and Hg) for 5 soil samples, representing 5 different pollution scenarios. For each amendment, the analyses using XRD and XRF to identify their properties, the toxicity characteristics leaching procedure (TCLP) test, and the synthetic precipitation leaching procedure (SPLP) test were also conducted to evaluate the leaching safety in applied site. From results of batch experiments, the amendments showing > 20% extraction lowering efficiency for each heavy metal (metalloid) was selected and the top 5 ranked amendments were determined at different amount of amendment and on different extraction time conditions. For each amendment, the total number of times ranked in the top 5 was counted, prioritizing the feasible amendment for specific domestic contaminated sites in Korea. Mine drainage treatment sludge, iron oxide, calcium oxide, calcium hydroxide, calcite, iron sulfide, biochar showed high extraction decreasing efficiency for heavy metals in descending order. When the economic efficiency for these amendments was analyzed, mine drainage treatment sludge, limestone, steel making slag, calcium oxide, calcium hydroxide were determined as the priority amendment for the Korean field application in descending order.

• Korean journal of food and cookery science
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• v.30 no.6
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• pp.774-784
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• 2014

The purpose of this study was to present management guidelines for critical control points by analyzing microbiological hazardous elements through screening Potentially Hazardous Foods (PHF) menus in an effort improve the microbiological quality of foods prepared by restaurant operations. Steamed spinach with seasoning left at room temperature presents a range of risk temperatures which microorganisms could flourish, and it exceeded all microbiological safety limits in our study. On the other hand, steamed spinach with seasoning stored in a refrigerator had Aerobic Plate Counts of $2.86{\pm}0.5{\log}\;CFU/g$ and all other microbiological tests showed that their levels were below the limit. The standard plate counts of raw materials of lettuce and tomato were $4.66{\pm}0.4{\log}\;CFU/g$ and $3.08{\pm}0.4{\log}\;CFU/g$, respectively. Upon washing, the standard plate counts were $3.12{\pm}0.6{\log}\;CFU/g$ and $2.10{\pm}0.3{\log}\;CFU/g$, respectively, but upon washing after chlorination, those were $2.23{\pm}0.3{\log}\;CFU/g$ and $0.72{\pm}0.7{\log}\;CFU/g$, respectively. The standard plate counts of baby greens, radicchio and leek were $6.02{\pm}0.5{\log}\;CFU/g$, $5.76{\pm}0.1{\log}\;CFU/g$ and $6.83{\pm}0.5{\log}\;CFU/g$, respectively. After 5 minutes of chlorination, the standard plate counts were $4.10{\pm}0.6{\log}\;CFU/g$, $5.14{\pm}0.1{\log}\;CFU/g$ and $5.30{\pm}0.3{\log}\;CFU/g$, respectively. After 10 minutes of chlorination treatment, the standard plate counts were $2.58{\pm}0.3{\log}\;CFU/g$, $4.27{\pm}0.6{\log}\;CFU/g$, and $4.18{\pm}0.5{\log}\;CFU/g$, respectively. The microbial levels decreased as the time of chlorination increased. This study showed that the microbiological quality of foods was improved with the proper practices of time-temperature control, sanitization control, seasoning control, and personal and surface sanitization control. It also presents management guidelines for the control of potentially hazardous foods at the critical control points in the process of restaurant operations.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.355-358
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• 2013

BACKGROUND: Water-born pollution loads by agricultural non-point source (NPS) pollution are expected to become intensified due to ongoing precipitation change. Therefore, it is essential to develop a best management practice (BMP) that is suitable to agricultural environments in Korea. This study aimed to develop an environmental-friendly BMP to reduce NPS pollution load by agricultural activities. An eco-friendly way, small drainage pond, was suggested in this study to avoid direct drainage of agricultural runoffs and eventually reduce the amount of pollutants discharged into the surrounding aqua-environment. METHODS AND RESULTS: A small pond ($12m^2$) was constructed at the corner of a rice paddy field ($1,715m^2$) located in Suwon, Korea. Water was allowed to drain only via a small drainage pond. Sampling was repeatedly made at two locations, one from an entrance and the other from an exit of a pond, during the rice cultivation period (May to October, 2012). Generally, sampling was made only when runoff water drained through a pond, such as during and/or after rain (irrigation). The water quality analysis showed that all quality parameters (SS, $COD_{Mn}$, T-N, and T-P) were improved as water passed through the pond. The amount of runoff water was reduced by 96~100%. Suspended solids and COD concentrations was reduced by 79.3% and 45.6%, respectively. In case of T-N and T-P concentrations, the reduction rates were 52.2% and 60.5%, respectively and the amount of T-N and T-P were reduced by 16.3~73.0% and 15.4~70.1%, respectively. CONCLUSION(S): Our data implies that agricultural NPS pollution from rice paddy fields can be effectively managed when an appropriate drainage water management practice is imposed. In this paper, it was suggested that an installation of a small drainage pond can be effective to prevent not only the nutrient loss from rice fields but also pollutant discharge to surrounding water environments.