• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.8-9
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• 2017

Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.240-240
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• 2017

Quinoa (Chenopodium quinoa Willd.) is one of the ancient crops cultivated in the Andes region at an altitude of 3,500-4000m in Chile and Bolivia from 5000 BC. It contains a large amount of protein, minerals and vitamins in comparison with other crops. The cultivation area has been increasing worldwide because of its excellent resistance to various abiotic stress such as salinity, drought and low temperature. ${\gamma}$-Ray radiation of high dose is often used as a tool to induce mutations in plant breeding, but it has a deleterious effect on organisms. However, the radiation may have a positive stimulatory effect of 'hormesis' in the low dose range. This experiment was carried out to investigate the optimum dose range for creating the quinoa genetic resources and to investigate the hormesis effect at low dose on the quinoa. This experiment was performed for 120 days from November, 2016 to February, 2017 in the greenhouse of Gyeongsang National University. ${\gamma}$-Ray radiation was irradiated to seeds at 0 Gy, 50 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 600 Gy, 800 Gy and 1000 Gy for 8 hours. (50 Gy) using the low level radiation facility ($Co^{60}$) of Cooperative Research Institute of Radiation Research Institute, KAERI. Fifty seeds were placed on each petri dish lined with wet filter paper and germination rate was measured at a time interval of 2 hours for 40 hrs. The length of the root length was measured one week after germination. Each treatment was carried out in 3 replicates. The growth of seedlings were investigated for 10 days after transplanting of 30 day-old seedlings. The plant height, NDVI, SPAD, Fv/Fm, and panicle weight were measured. The germination rate was highest at 50Gy and 0Gy and the rate of seeds treated with 400Gy or higher rate decreased to 25% of the seeds treated with 50Gy. The emergence rate of seedling in pot experiment was higher at the dose of 200 Gy, 300 Gy and 400 Gy than at 0 and 50Gy. However, the rate was lower at strong radiation higher than 600Gy at which $1^{st}$ leaf was not expanded fully and dead due to extreme overgrowth at 44 days after treatment (DAT). The highest value of panicle weight was observed at 50Gy (6.15g) and 100Gy (5.57g). On the other hand, the weight at high irradiated dose of 300Gy and 400Gy was decreased by about 55% compared to low dose (50 Gy). NDVI measurement also showed the highest value at 50 Gy as the growth progressed. SPAD was the highest at 400 Gy and showed positive correlation with irradiation dose except 0 Gy. Fv/Fm was high at 50 Gy up to 30 DAT and no difference between treatments was observed except for 400 Gy from 44 DAT. The plant height was the highest in 50Gy during the growing period and was higher in the order of 50Dy, 100Gy, 0Gy, 200Gy, 300Gy and 400Gy in 88 DAT. In this experiment, the optimal radiation dose for hormesis was 50Gy and 100Gy, and the optimal radiation dose for mutagenesis seems to be 400 Gy.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.13-23
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• 2001

Bentonite layers are intercalated within the basal conglomerates in the Tertiary sedimentary basins of Kampo, Janggi and Pohang, southeastern Korea. Eighteen samples of the bentonites went through X-ray diffraction, scanning electron microscopy, heavy mineral analyses, chemical analyses and oxygen, hydrogen stable isotope analyses to define the mineralogical characters of the bentonites. Heavy minerals such as zircons, apatites, amphiboles and biotites separated from bentonites show clean and euhedral surfaces, which are the characteristic features of volcanic origin. But biotites from the Chunbook Conglomerate are found as altered and heavily broken flakes which implies longer transportation of these bentonites. $TiO_{2}/Al_{2}O_{3} ratios of <2 $\mu$m particle fractions (the Chunbook Conglomerate 0.031; Janggi 0.029; Kampo 0.025) suggest that those are originated from volcanic tuffs. That is, the higher the value is, the more mafic in chemical compositions of the original tuffs. Authigenic montmorillonite and zeolite minerals were observed by SEM, which indicates diagenesis origin of bentonites. But the samples from the Chunbook Conglomerate showed only chaotically packed clay flakes in the matrix of sands or conglomerates, which implies detrital influence, not authigenic origin. The structural formulae of montmorillonite from these basins reflects their environment of formation. Fe (Ⅵ) can show the redox condition of its past environment and much lower $Fe^{2+}(Ⅵ)/Fe^{3+}(Ⅵ)$ ratios in montmorillonite of the Chunbook Conglomerate imply the greater oxidizing influence. Calculated burial depths from oxygen stable isotope data of the samples from the Chunbook Conglomerate generally fall to the range of 929~963 m whereas the real burial depth of this area is only 530~580 m. This could be explained as the bentonites of the Chunbook conglomerate had not been formed in situ. Discriminant analyses with the data from chemical analyses and structural formulae of montmorillonites show that bentonites from three different basins could definitely be distinguished with each other. This result arises from the different chemical compositions of original volcanic ashes and the difference of sedimentary environments.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.435-444
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• 1999

The antimony deposits of the Hyundong mine, located in the northeastern part of the Sobaegsan massif, occur as hydrothermal quartz+carbonate veins and stockworks which fill the fault fractures developed in Precambrian metamOlphic rocks (mainly, granitic gneiss). Hydrothermal alteration occurs commonly in the vicinity of mineralized veins and is characterized by sericitization and silicification. A K-Ar age of alteration sericite is 139.2$\pm$ 4.4 Ma, implying the early Cretaceous age of mineralization, possibly in association with intrusion of nearby acidic dikes (mainly, quartz porphyry). The hydrothermal mineralization occurred in five mineralization stages. These are: (I) stage I, characterized by deposition of chalcedonic quartz; (2) stage II, deposition of quartz with base-metal sulfides and stibnite; (3) stage III, deposition of quartz and carbonates (calcite, dolomite, ankerite, rhodochrosite) with various antimony-bearing minerals such as stibnite, polybasite, berthierite, native antimony, gudmundite and ullmannite; (4) stage IV, deposition of calcite with stibnite; and (5) stage V, deposition of barren calcite. Antimony occurs mostly as stibnite within stages II to IV veins, which has various habits including disseminated, veinlets and euhedral coarse crystals. Fluid inclusion studies indicate that hydrothermal mineralization at Hyundong occurred from the fluids with temperature and salinity of $330^{\circ}$C to 120 and 5.3 wI. % equiv. NaCI. The temperature and salinity of ore fluids systematically decreased with elapsed time in the course of mineralization, possibly due to the influx of larger amounts of meteoric groundwater. The deposition of antimony-bearing minerals occurred at low temperatures «$250^{\circ}$C), mainly due to the cooling and dilution of fluids. Based on the evidence of fluid boiling during the early stage II mineralization, the mineralization occurred under low pressure conditions (about 80 bars, corresponding to depths of about 350 m under hydrostatic pressure regime). Thermodynamic considerations of ore . mineral assemblages indicate that antimony deposition also occurred as the results of decreases in temperature and sulfur fugacity of hydrothermal fluids. Calculated sulfur isotope composition of ore fluids ($\delta^{34}S_{\Sigma s}$=5.4 to 7.8$\textperthousand$) indicates an igneous source of sulfur.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.337-350
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• 1995

The Hwacheon-ri mineralized area is located within the Cretaceous Gyeongsang Basin of the Korean peninsula. The mineralized area includes the Hwacheon, Daeweon, Kuryong and Cheongryong mines. Each of these mines occurs along copper-bearing hydrothermal quartz veins that crosscut late Cretaceous volcanic rocks, although some disseminated ores in host rocks also exist locally. Mineralization can be separated into three distinct stages (I, II, and III) which developed along preexisting fracture zones. Stage I is ore-bearing, whereas stages II and III are barren. The main phase of ore mineralization, stage I, can be classified into three substages (Ia, Ib and Ic) based on ore mineral assemblages and textures. Substage Ia is characterized by pyrite-arsenopyrite-molybdenite-pyrrhotite assemblage and is most common at the Hwacheon deposit. Substage Ib is represented by main precipitation of Cu, Zn, and Pb minerals. Substage Ic is characteristic of hematite occurrence and is shown only at the Kuryong and Cheongryong deposits. Some differences in the ore mineralization at each mine in the area suggest that the evolution of hydrothermal fluids in the area varied in space (both vertically and horizontally) with respect to igneous rocks relating the ore mineralization. Fluid inclusion data show that stage I ore mineralization mainly occurred at temperatures between ${\approx}350^{\circ}$ and ${\approx}200^{\circ}C$ from fluids with salinities between 9.2 and 0.5 wt.% eq. NaCl. In the waning period of substage Ia, the high temperature and salinity fluid gave way to progressively cooler, more dilute fluids of later substage Ib and Ic (down to $200^{\circ}C$, 0 wt.% NaCl). There is a systematic decrease in the calculated ${\delta}^{18}O_{H2O}$ values with paragenetic time in the Hwacheon-ri hydrothermal system from values of ${\approx}2.7$‰ for substage Ia, through ${\approx}-2.8$‰ for substage Ib, to ${\approx}-9.9$‰ for substage Ic. The ${\delta}D$ values of fluid inclusion water also decrease with decreasing temperature (except for the Daeweon deposit) from -62‰ (substage Ia) to -80‰ (substage Ic and stage III). These trends are interpreted to indicate the progressive cooler, more oxidizing unexchanged meteoric water inundation of an initial hydrothermal system which is composed of highly exchanged meteoric water. Equilibrium thermodynamic interpretation of the mineral assemblages with the variation in amounts of chalcopyrite through the paragenetic time, and the evolution of the Hwacheon-ri hydrothermal fluids indicate that the solubility of copper chloride complexes in the hydrothermal system was mainly controlled by the variation of temperature and $fo_2$ conditions.

• Journal of Korean society of Dental Hygiene
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• v.3 no.2
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• pp.127-141
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• 2003

The present study conducted a survey on the correlation between job satisfaction of dental hygienists and their workplace satisfaction and quality of life. A total of 249 surveys eligible among all the collected surveys were used in the analysis. The survey consisted of 61 items; 35 items were about self-evaluations of their satisfaction with their tasks, occupation, and workplace, as well as the degree of self-affirmation and their family-related satisfaction; the rests were 26 WHOQOL-BREF items investigating the quality of life. Collected data were processed using the SPSS Ver. 10.0 calculating the reliability with the frequency, percentage, and Cronbach's ${\alpha}$. Besides, one-way ANOVA and linear regression analysis examined the correlation between the variables. The conclusion is as follows: 1. By Age: Job satisfaction and family-related satisfaction were highest in the subjects aged 30 or older($3.5377{\pm}0.6891$ at pF0.05 and $4.1789{\pm}0.5431$ at pF0.05, respectively), though the differences were not statistically significant). Workplace satisfaction and self-affirmation were also highest in those aged 30 or order($3.5753{\pm}0.4210$ at pE0.05 and $3.9695{\pm}0.4616$ at pE0.05, respectively). The differences were statistically significant. Quality of life was also highest in those aged 30 or older($3.4095{\pm}0.3529$, pF0.05). 2. By Types of Dental Institutions: Job satisfaction and workplace satisfaction were highest in the subjects who worked at the dental department in a general hospital($3.7431{\pm}0.5940$ at pF0.05 and $3.6615{\pm}0.4602$ at pF0.05. respectively), though without statistical significance. Self-affirmation was highest in those working in university hospitals($3.773{\pm}0.7151$, pF0.05), while family-related satisfaction was highest, though without statistical significance, in those working at the dental department in general hospitals($4.2500{\pm}0.5528$, pF0.05), who also showed highest quality of life with statistical significance($3.4046{\pm}0.4155$, pE0.05). 3. By Years at Work: The subjects who had worked as a dental hygienist for 12 years or more showed highest satisfaction or scores in all the variables investigated: job satisfaction($3.9326{\pm}0.6673$, pE0.05): workplace satisfaction($3.8316{\pm}0.4342$, pE0.05): self-affirmation($4.2000{\pm}0.4551$, pE0.05); family-related satisfaction($4.3778{\pm}0.4692$, pF0.5): and quality of life($3.5235{\pm}0.4323$, pF0.05). All but quality of life showed a difference with statistical significance. 4. Correlation between Quality of Life and Overall Job Satisfaction: Quality of life doesn't have a correlation with the subjects' satisfaction with their occupation or with their self-affirmation, while it does have a correlation with workplace satisfaction and family-related satisfaction(F=15.983, Sig=0.000, $R^2$=0.209). Besides, workplace satisfaction has a significant correlation with all the variables: job satisfaction, self-affirmation, family-related satisfaction, and quality of life(F=38.563, Sig=0.000, $R^2$=0.389). The above result shows that workplace satisfaction has a high correlation with job satisfaction, self-affirmation, family-related satisfaction and with quality of life. Consequently, to enhance satisfaction of dental hygienists with their workplace, it would be important to promote their autonomy and make desirable wokplace environments so that they can work efficiently with pride for their job.

• Journal of Korean society of Dental Hygiene
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• v.9 no.4
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• pp.753-767
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• 2009

Objectives : The study is to gain some basic material for the improvement of dental clinics' homepages through a survey investigation, in which college students of three Dental Hygienic departments participated in Kwangju and Cheollanamdo Province. Methods : In the investigation three factors were analyzed : the degree of knowledge on dental clinics' homepages, the degree of recognition on them, and whether they have paid a visit on them or not. A total of 509(96.8%) respondents are valid except 17sheets of responses. Results : 1. When asked about the degrees of knowledge on the formation of the homepages by students' years, the correct rate on Information Service was higher in a row of the second year, the first year, and the third year. And it shows statistically significant difference(p<0.05). In the part of Counseling Service, the rate of correct answers was highest in the second year, and then the first year and the third year. It also shows significant difference(p<0.05). In case of Visual Service, the second year got the highest rate of correct answers, and then the first year and the third year. Here is significant difference by the school years<0.01) 2. It was asked whether they have visited the dental clinics' homepages. The results are like this: 145 sophomores(28.5%) have visited them, and 115 juniors(22.6%) and 85 freshmen(16.7%), and it show significant difference (p<0.001). 3. It was asked how many sites they have visited. Among the freshmen, not a few students visited two sites (34, 9.9%), among sophomores 48 students visited five sites(13.9%), and among juniors the highest answers were two sites (41, 11.9%). It shows signigicant difference(p<0.01). 4. It was asked what is the purpose of the visits. At this 27 freshmen answered for having counseling(7.8%), and 80 sophomores(23.3%) and 43 juniors(12.5%) answered they visited them for the purpose of gaining some materials about their major. It shows significant difference(p<0.001). 5. It was asked with what opportunity they have visited them. They answered through searching activities like this : freshmen (68, 19.8%), sophomores (130, 37.9%), and juniors (98, 28.6%). It shows significant difference(p<0.05). 6. In regard with the recognition of the homepages, all the participants said that the management of the homepages are closely related with the images of the clinics($3.96{\pm}0.781$). But it is found that they do not think that the effective management of dental clinics' homepages is the task of dental hygienic workers as a part of dental hygienic($3.12{\pm}0.971$). 7. There is some difference concerned with the homepages among each group of students; sophomores have highest recognition on them and then juniors and freshmen, and it shows significant difference(p<0.01). In addition, those who have visited them show higher recognition than those who have never visited them(p<0.001). Conclusions : There are some differences among each group of students in regard with the formation service, the purpose of visiting them and such experiences, and the opportunities. Whereases they think that the management of the homepages are closely related with the images of the clinics, they do not think that the effective management of dental clinics' homepages is the task of dental hygienic workers as a part of dental hygienic. Therefore it is necessary to study actively for the qualitative improvement of the dental clinics' homepages, which will result in the higher recognition on the homepages by the dental hygienic students and the workers.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.35-46
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• 2015

Recently, much attention has been paid to the development of a value-added food category containing probiotics so as to improve human health and prevent diseases. Among various foods, the health benefits of milk and dairy products are known to humanity, and could be attributed to the bioactive components present in milk. In fermented milk products, the health benefits could be due to suitable modulation activities produced by the action of probiotic bacteria. Besides the modification of various milk components, probiotics might also act directly as preventive and therapeutic agents against some severe diseases. Probiotics promote health via their positive effects on the immune response, stimulation of natural immunity, and modulation of the production of antimicrobial peptides, cytokines, and so on. Whey proteins, a byproduct of cheese production could also have anticarcinogenic, immunostimulatory, antimicrobial, and health-promoting activities such as improving insulin sensitivity and reducing fat deposition. Therefore, milk and dairy products containing probiotics could provide various opportunities in the field of functional foods. Additionally, these functional foods may be important in the human diet and may help improve human health and prevent diseases.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.47-57
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• 2015

Sodium is an essential nutrient with very important functions, including regulation of the extracellular fluid volume and active transport of molecules across the cell membranes. Since high levels of dietary sodium are associated with a high prevalence of hypertension, prehypertension, and other adverse effects on health, many national and international health organizations (WHO, FAO, etc.) recommend that sodium intake should be significantly decreased. In developed nations, cheese products, from among many processed foods, can cause high salt intake. Hence, there is an urgent need to reduce the content of salt in cheese processing, using various substitutes of sodium chloride (NaCl). In general, salt (NaCl) has been used as a food preservative to limit and (or) kill the growth of foodborne pathogens and spoilage organisms by decreasing the water activity, and to improve texture and flavor. To maintain public health, the salt content in cheese should be decreased without influencing the physicochemical properties of cheese. Therefore, the objective of this review is to outline the upcoming technologies used to reduce the salt content in different types of cheese using various substitutes.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.133-141
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• 2013

This study was performed to identify the cheese starter potential of antifungal lactic acid bacteria isolated from Kimchi. Eight fungi were isolated from cheese or the cheese ripening room, and identified as Penicillium and Cladosporium by ITS-5.8S rDNA analysis. Twenty-two lactic acid bacteria species with antifungal activity were isolated from Kimchi, and identified as Lactobacillus and Pediococcus by 16S rRNA sequence analysis. Six lactic acid bacteria species were selected (L. sakei subsp. ALJ011, L. sakei subsp. ALI033, L. sakei subsp. ALGy039, P. pentosaceus ALJ015, P. pentosaceus ALJ024, and P. pentosaceus ALJ026) based on higher antifungal activity from the initial 22 species. Out of the six identified species, L. sakei subsp. ALI033 had the highest antifungal activity. For growth of the six lactic acid bacteria, optimal temperature and pH were $30{\sim}37^{\circ}C$ and 7.0, respectively. Proteolytic activities of the six lactic acid bacteria were almost as strong as the commercial strain Str. thermophilus Body-1. Coagulative activities of L. sakei subsp. ALI033, P. pentosaceus ALJ015, and P. pentosaceus ALJ024 were higher than those of L. sakei subsp. ALJ011, L. sakei subsp. ALGy039, and P. pentosaceus ALJ026. The acid resistance of L. sakei subsp. was higher than that of P. pentosaceus. The major organic acid component of the lactic acid bacteria culture medium was lactic acid.