• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.59-59
• /
• 2017

Rice (Oryza sativa L.) is the most important crop and its yield must be improved to feed the increasing global population. Recently developed high-yielding varieties with extra-large sink capacity often have a problem in unstable grain-filling. Therefore, understanding limiting factors for improving grain-filling and controlling them are essential for further improvement of rice grain yield. However, since grain-filling rate was determined by complex sink-source balance, the ability of grain-filling was very difficult to evaluate. Source ability for 'grain' was not only determined by the ability of carbon assimilation in leaves, but also that of carbon translocation from leaves to panicles. Sink strength was determined by the complex carbon metabolism from sucrose degradation to starch synthesis. Hence, to evaluate the grain-filling ability and determine its regulatory steps, the whole picture of carbon flow from photosynthesis at leaves to starch synthesis at grains must be revealed in a metabolite level. In this study, the yield and grain growth rate of three high-yielding varieties, which show high sink capacity commonly, were compared. Momiroman showed lower grain filling rate and slower grain growth rate than the other varieties, Hokuriku 193 and Tequing. To clarify the limiting point in the carbon flow of Momiroman, $CO_2$ labeled by stable isotope ($^{13}C$) was fed to three varieties during ripening period. The ratio of $^{13}C$ left in the stem was higher in Momiroman 24 hours after feeding, suggesting inefficient carbon translocation of Momiroman. More interestingly, $^{13}C$ translocation from soluble fraction to insoluble one in the grain seemed to be slower in Momiroman. To get the further insight in a metabolite level, we are now trying the $^{13}C$ labeling metabolome analysis in the developing grains.

• Journal of Food Hygiene and Safety
• /
• v.26 no.4
• /
• pp.289-295
• /
• 2011

Produce, including leafy vegetables, has been implicated in several outbreaks of food illness. To evaluate microbiological safety of lettuce and it's cultivation area, a total of 147 samples were collected from lettuce farms and post harvest facility at Icheon, Gyeonggi province. The collected samples were assessed for presence of sanitary indicator microorganisms (Aerobic plate count, coliform count, Escherichia coli) and foodborne pathogens (Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus). The population of APC was over 4.0 log CFU from most of the samples. While the numbers of APC, and coliform of lettuce at 62 days after transplanting were 4.18 log CFU/g, and 1.00 log CFU/g, respectively, those of 10 days after transplanting were 5.37 log CFU/g, and 2.87 log CFU/g, respectively. B. cereus was highly detected from soil and balance which were contaminated with 3.5 log CFU/g, and 2.6 log CFU/100 $cm^2$, respectively. The number of E. coli recovered from gloves was 3.5 log CFU/hand. However, E. coli O157:H7, Salmonella spp., and L. monocytogenes were not detected. These data suggested that risk management system should be introduced to lettuce farms to enhance safety of lettuce.

• Journal of the Korean Geographical Society
• /
• v.43 no.4
• /
• pp.561-579
• /
• 2008

The population concentration in Seoul has caused the chronic housing shortage. Accordingly the new towns in the Capital region were developed to alleviate overcrowding conditions in Seoul. The purpose of this study is to analyze changes of migration and commuting patterns according to new town development in the Capital region for the period of $1995{\sim}2005$. Further this study examines the changes of self-sufficiency level for new towns using jobs to housing ratio. During the last 10 years, the migration pattern in the Capital region has been pretty much followed the new town development. Such a migration pattern has influenced the commuting patterns, expanding the Seoul Metropolitan Area into northeastern par of the Capital region. The result reveals that self-sufficiency levels of new towns have become higher over the period of $1995{\sim}2005$, indicating that new towns are gradually strengthening their economic functions and have potential to become new business centers in the future. Therefore, the policy focusing on the increase of the job-housing balance ratio and self-sufficient level in new towns will be a desirable policy alternative to solve the transportation problems in the Capital region.

• Journal of Gastric Cancer
• /
• v.3 no.4
• /
• pp.186-190
• /
• 2003

Purpose: The balance between cell proliferation and apoptosis is crucial for homeostatic maintenance in a cell population. Decreased apoptosis or uncontrolled proliferation can lead to cancer. The Fas receptor signal through a cytoplasmic death domain is very important in the apoptotic pathway. To identify the effect of the death domain of the Fas gene in the development and/or progression of gastric cancer, we examined the apoptotic potential of five known Fas mutants detected in gastric cancers. Materials and Methods: A wild-type Fas gene was cloned with cDNA from normal liver tissue and full length Fas was sequenced. Mutants of the gene were generated with sitedirected mutagenesis by using the wild-type gene and specific primers. Wild- and mutant-type genes were transfected to HEK293 cells. Forty-eight hours after transfection the cells were stained with DAPI and cell death was counted under fluorescent microscopy. Results: In wild-type Fas-transfected cells, the percentage of apoptotic cells was $85.9\pm3.6\%$, and significant cell death and classic morphologic signs of apoptosis were observed. However, the percentages of apoptotic cells transfected with N239D, E240G, D244V, and R263H of tumor-derived mutant Fas were $29.5\pm2.08\%,\;28.5\pm3.34\%,\;25.225\pm2.06\%,\;and\;36.625\pm4.49\%$, respectively. Conclusion: These results suggest that inactivation of Fas caused by mutations in the death domain of the Fas gene may be one of the possible escape mechanisms against Fas-mediated apoptosis and that inactivating mutation of the Fas may contribute to the development or progression of gastric cancers.

• Korean Journal of Community Nutrition
• /
• v.3 no.5
• /
• pp.748-758
• /
• 1998

The Recommended Dietary Allowances(RDAs, Nutrient standards), dietary guidelines, and food guides, each define aspects for a healthy diet in different ways. The RDA and food guide for Koreans were first established in 1962 by the Food and Nutrition Committee of the Korea FAO Association. The committee released the RDA and suggested ways to intake the recommended nutrients. Every five years, the committee has added more data and released revisions. The latest edition of the RDA is the 6th revision. In the beginning, the concept of basic food groups was emphasized as basic data for planning means based on RDA. In the 5th revision, the basic food groups and dietary guideline for public health from the Ministry of Health and Welfairs(December, 1990) suggests that, 1) Eat a variety of foods with a recommended fat intake equaling or less than 20% of total calories ; 2) Maintain ideal body weight and prevent obesity ; 3) Eat foods low in salt. Salt intake should not exceed 10g ; 4) Do not drink too much ; 5) Eat regularly and enjoy meals. After these guidelines were established, the first nutritonal education efforts guidelines were developed in 1984. Despite broad possibilities for application, they had limited use, mainly as a nutritional assessment and food balance sheet preparation. They were not well utilized in public nutritional education and nutritonal policy through the media because of the weakness of the government's food and nutriton policy. Also a lack of administrative support and dietitians in the health department and administrative organizations was partly to blame. In regard to public health and nutrition status, life expectancy has increased 10 years since the 70's and the elderly population increased threefold in 1995 compared to 1960. The common causes of death in 1996 by 19 Chapters classification, were first disease of the circulatory system ; the second, neoplasms ; the third, external causes fo mortality ; the forth, diseases of the digestive system ; and the fifth, respiratory system diseases, In food intake, grain and complex starch intake has decreased while fruit and animal foods have considerably increased. Therefore, energy from carbohydrates has decreased while energy from protein and fat has increased. Energy intakes from protein, fat and carbohydrates were respectively 12.5, 7.2 and 80.3% in 1969 but 16.1, 19.1 and 64.8% in 1995. 62.9% of the householes had the fat energy less than 20%, while 37.1% had the fat energy above 20%. The only intakes of vitamin A and calcium were below RDA levles. Therefore, nationwide attention should be focused on public nutriton education and public activities with supplementation of the RDAs, according to the food guide and the dietary guideline.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.286-293
• /
• 2005

An interpretation on the solid circulation characteristics in a fluidized-bed process has been carried out as a first step to simulate the dry entrained-bed absorption and bubbling-bed regeneration system for $CO_2$ removal from flue gas. A particle population balance has been developed to determine the solid flow rates and particle size distributions in the process. Effects of principal process parameters have been discussed in a laboratory scale process (absorption column: 25 mm i.d., 6 m in height; regeneration column: 0.1 m i.d., 1.2 m in height). The particle size distributions in absorption and regeneration columns were nearly the same. As gas velocity or static bed height in the absorption column increased, soild circulation rate and feed rate of fresh sorbent increased, however, mean particle diameter decreased in the absorption column. As cut diameter of the cyclone of the absorption column increased, solid circulation rate decreased, whereas feed rate of fresh sorbent and mean particle diameter in the absorption column increased. As attrition coefficient of sorbent particle increased, solid circulation rate and feed rate of fresh sorbent increased but mean particle diameter in the absorption column decreased.

• Journal of Korea Water Resources Association
• /
• v.53 no.9
• /
• pp.691-699
• /
• 2020

South Korea's available water resources per capita is very small compared to global average as there is a high population on small land. Thus, it is imperative to secure water resources for the safe livelihood of the citizens. As an advanced, industrialized country, South Korean economic dependence on agricultural has greatly lowered. Unless South Korea utilizes foreign water resources, it is impossible to provide agricultural and livestock products the same as current levels. However, virtual water-related research in South Korea is still inadequate. When establishing the water resources plan, it does not consider the international trade of virtual water. This research aims to solve this issue by analyzing the international virtual water trends focusing on South Korea. Consequently, the export and import of virtual water trade was identified according to country and item for 248 countries and South Korea. According to the results, South Korea's agricultural and livestock virtual water has much higher imports than exports, which outputs with agricultural by-products being the main import. In 2018, South Korea imported 72.2 billion ㎥, which is 29 times the exported amount of 2.5 billion ㎥. The research results can be used as baseline data for establishing the national water resources plan in the future.

• Journal of Environmental Science International
• /
• v.3 no.2
• /
• pp.165-175
• /
• 1994

An emergy analysis of the main energy flows driving the economy of humans and life support systems was made including environmental energies, fuels, and imports, all expressed as solar emjoules. The total emergy use (4, 373 E20 sej/yr) is 90 per cent from imported sources, fuels and goods and services. The emergy flows from the environment are modest, because the share of global inputs such as ruin and geological uplift flux is modest. Consequently, the ratio of outside investment to attracting natural resources is already large, like other industrialized countries. The population level is already in excess of carrying capacity. The emergy use per person in Korea indicates a moderate emergy standard of living, even though the indigenous resource is very poor. If the present economy were running entirely on stored reserves of fuels, soils, woods, etc., it would last about 2 years. Its carrying capacity for steady state on its renewable sources is only 3.3 million people, compared to 43.3 million in 1991. Continued availability of foreign oil at a favorable balance of emergy trade, currently about 7 to 1 net emergy, is the basis for present economic activity and must decrease as the net emergy of foreign oil purchased goes down. Close economic integration with Middle East may determine how long this is possible in the future.

• The Korean Nurse
• /
• v.33 no.2
• /
• pp.45-58
• /
• 1994

This study was conducted for the purpose of identifying the trends of nursing research and to suggest the direction of future research in the graduate levels of the study. The data was collected from 469 abstracts of master's and doctoral rapers from three graduate schools, one in Nursing, another in Education, and the other in Public Health Graduate College. The results of the study are as follows: The number of research was increased from 102 to 286 between the 1970 s and 1980's. The most frequently employed research design was descriptive studies in the master's level, but there was some balance between descriptive and experimental studies along with some qualitative approaches in the doctoral thesis. Patients were the most often studied sample group reaching 42% of the cases, though it Was noted that there was steady shift: toward the non-ratient population. With this shifting of the study sample, the places of the study also have showed some changes moving toward community. The most widely studied area was in clinical practice. Chronic illness, preventive, and health promoting areas of studies also increased in numbers. However, most of them were at the descriptive level of phenomena and only a few were concerned with cost/effective measures of nursing intervention. The number of variables studied repeatedly more than five times was 43. They were not only physical but also psychosocial aspects which imply the efforts to incorporate the whole person in nursing discipline. However, most researches with repeated studies showed little relation to previous studies, and thus little accumulation in knowledge. There was also little evidence of linkage to nursing theory in most studies of master's level. For the doctoral rapers, 17 out of 51 rapers showed specific theories related to the researches. Based on the above findings, the following suggestions were made. Various research design should be employed including case studies, historical studies, as well as qualitative approaches. There should be more effort to establish linkage between theory and research. The areas needing more attention are Korean Nursing History, Ethics in our Culture, Cost/Effective Measures of Nursing Intervention, Concept and Thory Development, and the Strategies for the Implication of the Research Results in clinical practice.

• Experimental and Molecular Medicine
• /
• v.50 no.12
• /
• pp.12.1-12.14
• /
• 2018

Osteoporosis develops with high prevalence in both postmenopausal women and hypogonadal men. Osteoporosis results in significant morbidity, but no cure has been established. Mesenchymal stem cells (MSCs) critically contribute to bone homeostasis and possess potent immunomodulatory/anti-inflammatory capability. Here, we investigated the therapeutic efficacy of using an infusion of MSCs to treat sex hormone-deficient bone loss and its underlying mechanisms. In particular, we compared the impacts of MSC cytotherapy in the two genders with the aim of examining potential gender differences. Using the gonadectomy (GNX) model, we confirmed that the osteoporotic phenotypes were substantially consistent between female and male mice. Importantly, systemic MSC transplantation (MSCT) not only rescued trabecular bone loss in GNX mice but also restored cortical bone mass and bone quality. Unexpectedly, no differences were detected between the genders. Furthermore, MSCT demonstrated an equal efficiency in rectifying the bone remodeling balance in both genders of GNX animals, as proven by the comparable recovery of bone formation and parallel normalization of bone resorption. Mechanistically, using green fluorescent protein (GFP)-based cell-tracing, we demonstrated rapid engraftment but poor inhabitation of donor MSCs in the GNX recipient bone marrow of each gender. Alternatively, MSCT uniformly reduced the $CD3^+T$-cell population and suppressed the serum levels of inflammatory cytokines in reversing female and male GNX osteoporosis, which was attributed to the ability of the MSC to induce T-cell apoptosis. Immunosuppression in the microenvironment eventually led to functional recovery of endogenous MSCs, which resulted in restored osteogenesis and normalized behavior to modulate osteoclastogenesis. Collectively, these data revealed recipient sexually monomorphic responses to MSC therapy in gonadal steroid deficiency-induced osteoporosis via immunosuppression/anti-inflammation and resident stem cell recovery.