• Journal of Wetlands Research
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• v.16 no.4
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• pp.363-370
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• 2014

We grew seedlings of Saechucheongbyeo and Odaebyeo of rice cultivars that are cultivated dominantly in the northern and middle regions of Korea under control(ambient condition), ambient $CO_2$ concentration+elevated temperature, and elevated $CO_2$ concentration+elevated temperature in order to study how growth responses and crop yield of major rice of Korea change as the global warming proceeds and compared the results. Aboveground biomass, belowground biomass, total biomass, and panicles weight per individual and ripended grain rate of cv. Saechucheongbyeo were the highest under control, but those of cv. Odaebyeo were the highest under elevated $CO_2$ concentration+elevated temperature. There was no difference in the number of panicles per individual of cv. Saechucheongbyeo and cv. Odaebyeo in these experiments. There was no difference in the number of grains per panicle of cv. Saechucheongbyeo among three environmental gradients, but that of cv. Odaebyeo was the highest under elevated $CO_2$ concentration+elevated temperature. Weight of a grain of cv. Saechucheongbyeo was highest under elevated $CO_2$ concentration+elevated temperature, but that of cv. Odaebyeo was the higher under ambient $CO_2$ concentration+elevated temperature and elevated $CO_2$ concentration+elevated temperature. Thus, if global warming continues in Korea, selection of rice cultivation varieties must be chosen carefully for commendation.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.15-29
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• 2021

The purpose of this study is to establish an ecosystem model that can predict ecosystem fluctuations in the Nakdong estuary, and use this model to calculate total primary production and respiration. AQUATOX model was used as the ecosystem model, and the model was calibrated and verified using the measured data. For the calibration of the model, chlorophyll-a data measured at the Nakdong estuary were used, and the model verification was performed using DO, TN, and TP data. In general, the total primary production and respiration volume vary greatly depending on the season, but the total primary production and respiration in the Nakdong estuary were greatly influenced by the amount of water discharged from Nakdong estuary bank. When the amount of effluent increased, photosynthesis could not be performed due to the loss of phytoplankton living in the lower area, and the total primary production amounted to zero, whereas the respiration increased sharply due to the inflow of organic substances contained in the effluent. The increase in the inflow water means the inflow of organic substances contained in the inflow water, and the organic substances are decomposed by oxidation, reducing dissolved oxygen. Compared with other countries' estuaries, the Nakdong estuary shows the lowest total primary production and because the respiration is larger than the total primary production, the dissolved oxygen is depleted by the oxidation of organic matter.

• KSBB Journal
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• v.15 no.4
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• pp.398-401
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• 2000

Taxiods inclusive paclitaxel were produced isolated and purified from plant cell cultures of Taxus chinensis in large-scale process. their structures were elucidated by spectroscopic analyses. These compounds were exactly identical as those in previous studies from the other biomasses of Taxus chinensis and also other species. Also the concentrations of these compounds were compared with the concentration of the paclitaxel in various batches of plant cell cultures. As paclitaxel concentration increased at the end of cell cultures. the concentrations of the other paclitaxel derivatives decreased. The profile of these taxoids production can provide information for better understanding of structure-activity relationships and biosynthesis Importantly it can be utilized as an useful parameter for the quality control of paclitaxel production.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.958-964
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• 2005

Experiment was conducted to investigate the amount of hydrogen gas and the characteristics of organic acids production from various carbohydrates by anaerobic bacteria. The variation characteristics of organic acids and hydrogen gas production at the fermentative culture were also studied in the presence of heavy metals such as cadmium or lopper. 3.43 mole hydrogen per mole of hexose was produced when sucrose was used as a carbon source. Acetic acid and butyric acid were main products by the anaerobic fermentation. Hydrogen production rate was decreased and formation of acetic acid was increased as the concentration of heavy metals was increased in the medium. The inhibition of hydrogen production by the copper was more serious than the cadmium.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2014.10a
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• pp.1-24
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• 2014

This study uses geo-spatial crop modeling to quantify the biophysical impact of weather extremes. More specifically, the study analyzes the weather extreme which affected maize production in the USA in 2012; it also estimates the effect of a similar weather extreme in 2050, using future climate scenarios. The secondary impact of the weather extreme on food security in the developing world is also assessed using trend analysis. Many studies have reported on the significant reduction in maize production in the USA due to the extreme weather event (combined heat wave and drought) that occurred in 2012. However, most of these studies focused on yield and did not assess the potential effect of weather extremes on food prices and security. The overall goal of this study was to use geo-spatial crop modeling and trend analysis to quantify the impact of weather extremes on both yield and, followed food security in the developing world. We used historical weather data for severe extreme events that have occurred in the USA. The data were obtained from the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA). In addition we used five climate scenarios: the baseline climate which is typical of the late 20th century (2000s) and four future climate scenarios which involve a combination of two emission scenarios (A1B and B1) and two global circulation models (CSIRO-Mk3.0 and MIROC 3.2). DSSAT 4.5 was combined with GRASS GIS for geo-spatial crop modeling. Simulated maize grain yield across all affected regions in the USA indicates that average grain yield across the USA Corn Belt would decrease by 29% when the weather extremes occur using the baseline climate. If the weather extreme were to occur under the A1B emission scenario in the 2050s, average grain yields would decrease by 38% and 57%, under the CSIRO-Mk3.0 and MIROC 3.2 global climate models, respectively. The weather extremes that occurred in the USA in 2012 resulted in a sharp increase in the world maize price. In addition, it likely played a role in the reduction in world maize consumption and trade in 2012/13, compared to 2011/12. The most vulnerable countries to the weather extremes are poor countries with high maize import dependency ratios including those countries in the Caribbean, northern Africa and western Asia. Other vulnerable countries include low-income countries with low import dependency ratios but which cannot afford highly-priced maize. The study also highlighted the pathways through which a weather extreme would affect food security, were it to occur in 2050 under climate change. Some of the policies which could help vulnerable countries counter the negative effects of weather extremes consist of social protection and safety net programs. Medium- to long-term adaptation strategies include increasing world food reserves to a level where they can be used to cover the production losses brought by weather extremes.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.237-243
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• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.134-136
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• 2003

강원도의 연도별 수산물생산실적을 조사한 표1에서 1995년도 어패류의 총 생산량이 88,030 백만톤이었으나 2000년도의 총생산량은 60,687백만톤으로 32 ％가 감소하였다. 이렇게 어획량이 감소하게된 주요원인은 해역의 환경변화가 크다고할 수 있는데, 수면을 육지화 하므로써 그 주위에서 어떠한 환경변화가 일어날 수 있으며 환경변화에 어떻게 대처할 것인가 하는 대책도 마련하여 개발에 따른 피해영향을 최소한으로 줄이고, 손상된 환경을 복원하고, 또한 이러한 것들이 불충분한 경우에는 새로운 환경을 재생, 창조하는 방법으로서 주문진 연안의 해안선과 기상, 해상 해저 등 물리적인 조건과 생물조건을 고려하여 주문진 해역에 적합한 인공어초를 제시하여야한다. (중략)

• KSBB Journal
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• v.14 no.1
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• pp.36-44
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• 1999

The biosynthesis of Lovastatin, a cholesterol lowering agent formed by the filamentous fungus Aspergillus terreus, was investigated in shaking flask. The effects of essential elements in the experimental medium such as carbon, nitrogen, phosphate sources, and amino acids were examined to increase Lovastatin productivity. Lovastatin production in shaking flasks was 68 mg/L in the used medium. Effect of carbon source on Lovastatin production was performed. As a carbon source in the medium, 45 mL/L of glycerol increased the Lovastatin production up to 256 mg/L, which was found to be improved almost 3.5 times in comparison with that in common medium. The optimum concventration of peptonized milk as nitrogen source was obtained 30g/L on Lovastatin production. The severe inhibition of the cell growth and the Lovastatin production were observed in shaking flasks conducted at the medium contained ammonium carbonate as a nitrogen source. Lovastatin production various concentrations of several phosphate compounds was also examined. The addition of either potassium phosphate diabsic or sodium phosphate dibasic increased the Lovastatin production and the optimal level of potassium phosphate dibasic was 6 g/L. Even though Lovastatin contain methionine-derived methyl group, L-methionine and DL-methionine tend to diminish the Lovastatin production. Among the amino acids, L-histidine and L-tryptophan had a remarkable enhancing effect on the Lovastatin production. The optimal concentration of L-histidine and L-tryptophan was 6g/L.

• KSBB Journal
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• v.21 no.2
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• pp.79-84
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• 2006

In order to minimize the reduction of lysine productivity by accumulation of lysine and byproducts in the end of fed-batch fermentations, a salt-tolerant mutant C14-49-3-15-7-3-20, which could grow at high concentrations of NaCl was isolated through mutagenesis from the Corynebacterium glutamicum mother strain I. In the evaluation of L-lysine productivity by fed-batch fermentations using a 5 L jar fermenter, the salt-tolerant mutant strain C14-49-3-15-7-3-20 produced 130.6 g/L of L-lysine with a 48.6% of yield. The mother strain I produced L-lysine concentration only 104.9 g/L with a yield 41.8%, implying the improvement of L-lysine productivity by introduction of salt-tolerance character.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.25-30
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• 2007

In order to estimate the ecological parameters of the population, short-necked clams, Ruditapes philippinarum, were collected from Jindu coast at Hansan Island, from April to December in 2005. The growth of the clam was estimated by von Bertalanffy growth model and each parameters were obtained from a nonlinear regression as $L_{\infty}\;=\;48.8\;mm$, k = 0.28 and $t_0\;=\;-0.88\;(R^2\;=\;0.994)$. Instantaneous coefficient of total mortality (Z) and fishing mortality (F) was calculated to be 0.8614/yr. and 0.6122/yr, respectively. The age at the first capture was estimated to be 2.88 year. Using the present parameter for clam fishing, the yield-per recruit (Y/R) was estimated to be 3.44g. Although the maximum Y/R was obtained under the parameters ($t_c\;=\;3.48\;yr$. and F = 0.9295/yr), it is favorable to maintain the current fishing effort considering the annual fluctuation of the parameters.