• Journal of Life Science
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• v.27 no.1
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• pp.100-121
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• 2017

The sexual reproduction of the unicellular green alga Chlamydomonas is reviewed for a comprehensive understanding of the complex processes. The sexual life cycle of C. reinhardtii is distinguished into five main stages: gametogenesis, gamete activation, cell fusion, zygote maturation, and meiosis and germination. Gametogenesis is induced by nitrogen starvation in the environment. C. reinhardtii has two mating types: mating type plus ($mt^+$) and mating type minus ($mt^-$), controlled by a single complex mating type locus ($MT^+$ or $MT^-$) on linkage group VI. In the early gametogenesis agglutinins are synthesized. The $mt^+$ and $mt^-$ agglutinins are encoded by the autosomal genes SAG1 (Sexual AGglutination1) and SAD1 (Sexual ADhesion1), respectively. The agglutinins are responsible for the flagellar adhesion of the two mating type of gametes. The flagellar adhesion initiates a cAMP mediated signal transduction pathways and activates the flagellar tips. In response to the cAMP signal, mating structures between two flagella are activated. The $mt^+$ and $mt^-$ gamete-specific fusion proteins, Fus1 and Hap2/Gcs1, are present on the plasma membrane of the two mating structures. Contact of the two mating structures leads to develop a fertilization tubule forming a cytoplasmic bridge between the two gametes. Upon fusion of nuclei and chloroplasts of $mt^+$ and $mt^-$ cells, the zygotes become zygospores. It is notable that the young zygote shows uniparental inheritance of chloroplast DNA from the $mt^+$ parent and mitochondrial DNA from the $mt^-$ parent. Under the favorable conditions, the zygospores divide meiotically and germinate and then new haploid progenies, vegetative cells, are released.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1093-1124
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• 2014

Studies on the role of agricultural science colleges are mostly divided into agricultural production, which is the primary function of agriculture, and other functions, which have recently begun to be emphasized as a result of social needs. With the green revolution and the aging of the farming population, there is a strong view that the role of agricultural science colleges should remain as it is. However, agriculture is expanding in terms of concept and content by converging with other industries not traditionally associated with agricultural production. Thus, the fields that now need to form part of agricultural science knowledge are becoming more detailed and expansive. The government's perception remains at the level of merely fostering farmers. This was evident in a survey on the employment rate, a factor used to evaluate colleges, in which the role of agricultural science colleges was limited to fostering farmers. Agro- industry fields, other than agriculturalists, include general industries in which the academic fields of agricultural science are combined with other academic fields. Thus, even when someone is employed in an industry that requires background knowledge of agricultural science, there is often a perception that he or she is employed in a field that is irrelevant to the major. This study examines the role of agricultural science colleges in agriculture and farm villages by focusing on the employment of graduates of these colleges within agro-industry. We categorize academic research on agricultural science into 16 fields, based on the medium level of the National Standard Science and Technology Classification Codes. Then, we categorize the employment fields into 168 fields, based on the small classification level of the inter-industry relations classification. Thus, we investigate 220 departments of 37 colleges, nationwide. Our findings show that the average employment rate of graduates of agricultural science colleges is 69.0%. Furthermore, 33.0% of all employees work in agro-industry fields that require background knowledge in agricultural science, which is one out of three job seekers. Then, 3.6% of employees work in business startups in agro-industry. The aforementioned government survey showed that only 0.1% of all college graduates in Korea were employed as agriculturalists in 2013. However, our results showed that 13.3% of graduates were working as agriculturalists, which is significantly different to the results of the government survey. These results confirm that agricultural science colleges contribute greatly to the employment of graduates, including farmers, agro-industry, and business startups in agro-industry fields.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.461-469
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• 2001

The combinatorial approach has been applied to discover and optimize the composition of the novel or enhanced materials. In this study, we screened the optimum composition of the system SrO-Gd$_2$O$_3$-Al$_2$O$_3$ doped with $Tb^{3+}$ by a polymerized-complex combinatorial chemistry method. Mixtures with compositions of Sr, Gd and Al component that is in the range from 0 to 1 in about 0.05 increments could be tested. The sample powders were synthesized by a polymerized complex method. To prepare appropriately polymeric precursors, we used the metallic nitrates, citric acid and ethylene glycol. The luminescence properties of the synthesized powders are investigated using the UV and VUV (Vacuum-UV: 147 nm) photoluminescence spectrometer. In addition, the crystallinity and morphology of powder were monitored by X-ray diffraction spectrometer and scanning electron microscopy. In result of VUV PL works, there are good luminescent samples with the composition of 0.595 < x < 0.733 and 0.016 < y < 0.017 in Gd1-x-yAlxTbyO$\delta$ and 0.049 < x < 0.064 and 0.02 < y < 0.039 in $Sr_xAl_{1-x-y}Tb_yO_$\delta$$, their materials can be applicable to plasma display panels as the green phosphor.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.56-61
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• 1997

This research was conducted to investigate morpological and growth characteristics of 358 Coix lacryma-jopbi mayuen STAF collected in Korea. The test collections contained 76% medium wide-type leaf, 59% medium size-type seed, 34% large size-type seed, 70% elliptical-type shell, 50% brown shell color, 92% low stem color and hardness of seed coat averaged $3.4kg/cm^2$ with the range of $1.1{\sim}18.7kg/cm^2$. 24% adaptable plant height ranged from 156cm to 170cm, days to heading after seeding averaged 83.2% with the range of $74{\sim}94$ days, early maturating varietes was 24.9% below 80 days. Rate to leaf blight 48.5% with the range of $9{\sim}92%$ and rate to stem borer averaged 8% with the range of $0{\sim}17%$. The weight of 1000 seeds showed positive correlation with days to flowering and plant height and number of seeds per plant showed positive corrleation with percentage of ripness, but weight of 1000 seeds showed negative correlation with occurrence of leaf blight and stem borer plant. Therefore we are expecting useful germplasm and selectable index for effective breeding.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.954-958
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• 2010

The study was conducted to investigate the relationship between berry set density per bearing shoot and fruit quality in 'Kyoho' grape. Fruit quality was evaluated by soluble solids content (SSC), titratable acidity (TA), skin color, and total anthocyanin content (TAC). There was a sharp increase in SSC of fruit juice from veraison initiation to 30 days after veraison. The SSC level increased with the lower berry set per bearing shoot. The rapid accumulation of SSC 4 weeks after veraison in the cluster of low berry set (10-20) was observed, while that of high berry set (40-50) showed delayed and low SSC accumulation which reached only $15.0^{\circ}Bx$ at harvest. TA of fruit juice in all treatments reduced rapidly from veraison initiation to 30 days after veraison, and then reduced gradually. TA in all treatments except 50 berries set reached to 0.4-0.6% which was optimal TA in 'Kyoho' at fruit harvest. During fruit maturing after veraison, fruit skin color changed from green to purple-black, L and b value decreased, and a value increased. TAC in 10 and 20 berries set was gradually increased to 2 weeks after veraison, sharply increased until 6 weeks after veraison, and then finally decreased, while TAC in content in 30, 40, and 50 berries set per annual shoot remained at low level. The results indicated that the number of berry set for good quality seemed to be 20 per bearing shoot in 'Kyoho' grape.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.68-79
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• 2017

The objective of study was to find the relationship in hilly pasture landscape expectancy and tourist's satisfaction on grassland facility. It was followed by literature reviews and visitors' survey in Daegwallyeong Yangtte Farm on 31, July, 2014. 367 respondents were analyzed by F-test, t-test, Chi-square and Fisher's Exact Test at 0.05 level after data screening process. Computing factors were sex, marital status, age, academic career and occupation. The results was as followed; First, major respondents group of survey were in oder of woman, forty years old group, married office worker, and university graduate. Second, the expectancy for grassland was significant difference in age, but pasture color expectancy was not significant difference in gender, age, educational background, marital status, and there was significant difference in favorite grassland type with age, marital status. Third, favorite fence type was not significant difference along with all group of participants. However, color and material of fence was significant difference in marital status. Fourth, preferred ranch road was significant difference with occupation and marital status. There was significant difference in favorite grassland type near ranch road along with age and occupation type. Fifth, the mean satisfaction was 3.6 point in 5.0. Therefore, all respondents were generally satisfaction in visited. Tourists were more interested in ranch landscape than experience or contacts to animal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.267-273
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• 2013

We evaluated the morphological characteristics of 79 popcorn inbred lines, which were developed to breeding popcorn variety at Maize Experiment Station, Gangwon Agricultural Research and Extension Services, by examining ten quantitative and three qualitative characteristics. In the survey of 3 qualitative traits for 79 popcorn inbred lines, most inbred lines respectively showed purple (46 inbred lines) at tassel color (QL1), green (55inbred lines) at silk color (QL2) and green (75 inbred lines) at stem color (QL3). While, on the survey of 10 quantitative traits among 79 popcorn inbred lines, they showed the morphological variation in plant height (QN1, $174.2{\pm}34.9$ cm), ear height (QN2, $103.4{\pm}24.7$ cm), ear length (QN3, $9.4{\pm}3.0$ cm), kernel setting length (QN4, $8.4{\pm}2.6$ cm), ear thickness (QN5, $24.9{\pm}7.7$ mm), ear row number (QN6, $14.0{\pm}2.3$ number), ear weight (QN7, $36.5{\pm}26.0$ g), kernel weight (QN8, $30.9{\pm}19.3$ g), 100 kernel weight (QN9, $10.4{\pm}3.8$ g) and germination rate (QN10, $95.3{\pm}8.1%$), respectively. As a result, 5 inbred lines (PS0-001, PS0-003, PS1-002, PS1-003, PS2-009) in the 79 popcorn inbred lines have showed comparatively high values for the five quantitative traits. On the principal component analysis, silk color (QL2), ear length (QN3), kernel setting length (QN4), ear thickness (QN5), ear weight (QN7), kernel weight (QN8) and 100 kernel weight (QN9) greatly contributed in positive direction on the first principal components, whereas tassel color (QL1), stem color (QL3), ear height (QN2) and ear row number (QN6) contributed in negative direction on the first principal component. In addition, plant height (QN1), ear height (QN2), and kernel weight (QN8) contributed in positive direction on the second principal component, and also tassel color (QL1), silk color (QL2), ear length (QN3), ear row number (QN6) and 100 kernel weight (QN9) contributed in negative direction on the second principal component.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.333-340
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• 2010

Wastewater treatment using algal communities and biodiesel production from wastewater-cultivated algal biomass is a promising green growth technology. In literature, there are many studies providing information on algal species producing high content of lipid. However, very little is known about adaptability and wastewater treatability of such high-lipid algal species. In this study, we attempted to characterize algal biomass production and wastewater treatability of high-lipid algal species under municipal wastewater condition. For this, four known high-lipid algal strains including Chlorella vulgaris AG 10032, Ankistrodesmus gracilis SAG 278-2, Scenedesmus quadricauda, and Botryococcus braunii UTEX 572 were individually inoculated into municipal wastewater where its indigenuous algal populations were removed prior to the inoculation, and the algae-inoculated wastewater was incubated in the presence of light source (80${\mu}E$) for 9 days in laboratory batch reactors. During the incubations, algal biomass production (dry weight) and the removals of dissolved organics (COD), nitrogen and phosphorous were measured in laboratory batch reactors. According to algal growth results, C. vulgaris, A. gracilis and S. quadricauda exhibited faster growth than indigenuous wastewater algal populations while B. braunii did not. The wastewater-growing strains exhibited efficient removals of total-N, ${NH_4}^+$-N, Total-P and ${PO_4}^{3-}$-P which satisfy the Korea water quality standards for effluent from municipal wastewater treatment plants. A. gracilis and S. quadricauda exhibited efficient and stable treatability of COD but C. vulgaris showed unstable treatability. Taken together with the results, A. gracilis and S. quadricauda were found to be suitable species for biomass production and wastewater treatment under municipal wastewater condition.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.687-696
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• 2015

Black mini tomato 'Hei-G' fruits were harvested at different stages of maturity (immature-mature green and mature-black red) and stored at different temperatures (8, 12, and $20^{\circ}C$) to investigate the quality and lycopene content during storage. Weight loss increased dramatically at higher temperature for both harvesting stages without significant differences. Firmness of immature fruits decreased below the initial level of mature fruit (8.1N) after 5, 8, and 19 days storage, when they were stored at 20, 12, and $8^{\circ}C$, respectively. Soluble solid contents of mature fruit increased at initial storage, and were higher as compared to immature fruits before deterioration at each storage temperature. Decrease in titratable acid of mature fruits depended on storage time and temperature. However, titratable acid of immature fruits showed little change during storage, and so it did not affect flavor. Hunter a value changed greatly in immature fruit stored at high temperature. Unlike ripe tomatoes, there was no significant difference in black tomato Hunter b values of immature and mature fruit at initial and 12 days storage. However, immature fruits stored at $8^{\circ}C$ did not reach full maturity and color development and ripening. High storage temperature increased lycopene production while low storage temperature blocked lycopene development. Shelf life of the immature fruits, which was evaluated by elapsed days to conventional mature stage, was 12 and 15 days when they were stored at 20 and $12^{\circ}C$, respectively. The optimum storage temperature to maintain the quality and lycopene content of mature fruits was $12^{\circ}C$. Moreover, the shelf life of mature fruits stored at $20^{\circ}C$ could reach up to 5 days.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.625-629
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• 2009

"Olgreen" (Scale cereal L.), a new rye variety was developed by National Institute of Crop Science(NICS), RDA. It was released in 2008 because of its high biomass yield potential and early maturity. It was developed from an open pollination within 10 rye varieties or lines including "Chochun" in 1995. The line 'SR95POP-S1-1072-1-2-4' was selected for its early maturity and excellent agronomic appearance, and placed in yield trials for two years from 2004 to 2005. It was designated "Homil 38" and placed in regional yield trials at the four locations around Korea from 2006 to 2008, from which the name "Olgreen" was given. Over three years, "Olgreen" averaged 8.88 ton ha-1 of forage yield (based on dry matter) harvested at late April and superior to other varieties with an increase of 10% more than the check variety "Olhomil", and 9% more than the introduced rye "Koolgrazer". Heading date of "Olgreen" was April 20 which was 3 days earlier than that of "Olhomil". It would be recommended as an early rye variety for forage or green manure in South Korea.