• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.48-57
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• 1991

Changes of the activities of the hepatic cells of female mud skipper, Boleophthalmus pectinirostris were investigated under transmission electron microscopy. Monthly changes of gonadosomatic index(GSI) and hepatosomatic index(HSI), variations of protein and nucleic acid contents(total RNA and DNA) of the liver tissues with the gonadal development phase were also studied. GSI began to increase from May(the growing stage), reaching the maximum value in late June(the mature stage), and then it began to decrease from late July(the degenerative stage), reaching the lowest value in late September. Monthly variations of HSI were negatively related to GSI. HSI decreased in the summer season when the ovary was getting mature and reached the maximum in mid October when the ovary was degenerating. In June(the mature stage), the female hepatic cells of the liver tissues became large and nuclei were hypertrophic. The amounts of glycogen particles and lipid droplets in the cells gradually decreased, while a number of granular endoplasmic reticulum increased. It was assumed that well-developed granular endoplasmic reticulum binding ribosomes are supposed to play the leading role in protein synthesis and deposition for vitellogenin in the cytoplasm. In July(the spawning period), glycogen particles and lipid droplets gradually increased, and then these substances were still observed in large quantity in August(the degenerative stage). The protein contents of the liver tissues with the gonadal phases of the ovaries were shown the maximum value($4.720{\pm}0.103\;mg/g$) in June, and afterwards gradually decreased being the minimum($3.640{\pm}0.130\;mg/g$) in July, and then gradually increased in August. The mean total RNA contents per gram of the liver tissues appeared the maximum($0.523{\pm}0.040\;mg/g$) in June, and afterwards gradually decreased to the minimum($0.158{\pm}0.006\;mg/g$) in July and slightly increased in August again. From these results, it could be assumed that protein contents were closely related to RNA contents. The mean total DNA contents per weight (gr) of the liver tissues appeared to be similar although there were some monthly fluctuations. The ratio of the mean total RNA/DNA were 0.745 in June, 0.262 in July, 0.341 in August respectively.

• Journal of Mushroom
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• v.7 no.4
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• pp.173-181
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• 2009

These studies were investigated for effect of concentration of sodium chloride on occurrence and growth of fruitbody in oyster mushroom, Pleurotus ostreatus. When the mycelia were inoculated and cultured on the PDA plate added with the different concentrations of sodium chloride, the growth of them were not affected at the concentration of 0.5%, started to decrease at 1.0% as compared with the PDA plate without sodium chloride, and they did not grow at 5.0%. When tested at the column filled with sawdust, the tendency was similar, but the decreasing rate of mycelial growth was gentle. In sawdust bottle cultivation sprinkled with the different concentration of sodium chloride solution at the different stage, the productivity and quality of fruitbody started to decrease at 3.0% of the solution and the yield at the treatment of 10.0% solution was only 47% of that in non-treated bottles. Treated at the different stages of mushroom development, treatment just after mushroom sprout did not show any different from that just after scraping spawn from the complete grown bottles. The sprinkle treatment at this stage looked better than that of the soaking with the solution before mushroom sprout. The yield at this treatment with 10% solution showed little damage with that of 90% of non-treated bottle. Sprinkle treatment during mushroom growth stage did not affect and showed almost same to non-treated bottle except the treatment with 10.0% solution. The treatment of this stage showed better results of growing characters than the treatment after and before mushroom sprouting even 10% solution. Morphological characteristics of oyster mushroom do not distinguish to treatment of different stage and concentration of sodium chloride solution. The analyzing data of quality on underwater usually used for oyster mushroom in Inchon, Yeongjong and Kanghwa area showed over-concentration to the standard for edible water and agricultural water. But it was not confirmed whether this water quality could affect to mushroom cultivation.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.665-676
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• 2016

As high temperature during citrus growing season has caused a serious problems including inferior coloration in production of mandarins in Korea, we were to investigate the expression pattern of several genes related with coloration during the ripening in high temperature condition of citrus fruits. The expression of genes related with sugar metabolism, cell wall degradation, and flavonoid synthesis in high temperature conditions was investigated in fruits of 'Haryejosaeng' (Citrus unshiu) and 'Shiranuhi' mandarin (C. reticulata). While the expression of beta-amylase (BMY), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and flavanone 3-hydroxylase (F3H) was differently induced, expression of polygalacturonase (PG) decreased dependently on temperature conditions. In 'Haryejosaeng' mandarin, while the expression of genes related to the skin coloration, such as CHS and F3H genes increased at $25^{\circ}C$, the expression of PAL and stilbene synthase (STS) genes were induced at $30-35^{\circ}C$ in all ripening stages. In 'Shiranuhi' mandarin, the expression of the BMY gene decreased at early time point in all temperature condition and then increased at $30-35^{\circ}C$ than at $25^{\circ}C$ in the ripening stage 2 to 3 of fruits. F3H and STS genes also showed the tendency to decrease at $30-35^{\circ}C$. Although the expression levels of genes in ripening stage 1 and stage 2 of fruits showed similar patterns in both 'Haryejosaeng' and 'Shiranuhi', the expression levels of genes were down-regulated in late ripening stage of 'Shiranuhi' fruits compared to 'Haryejosaeng'. In general, the mRNA levels of seven tested genes were higher in 'Haryejosaeng' than in 'Shiranuhi' mandarin, and expression of genes by high temperature was regulated sensitively in 'Haryejosaeng' compared to 'Shiranuhi' mandarin. Further investigations of expression of various genes based on transcriptome analysis in early ripening stage can provide valuable information about the responses to climatic changes in ripening citrus fruits.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.182-191
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• 1999

A study was conducted for the determination of application rate of pig-dung composted with sawdust (referred as pig manure hereafter) for wetland rice. The study involved the field experiments with the cultivation of rice under different rates of application of pig manure in combination of different rates of chemical fertilizers, in a wetland rice soil. The field experiment involved following treatments : (I) Without fertilizer, (II) Standard rate of chemical fertilizers based on soil testing($98-73-71kg\;ha^{-1}$ as $N-P_2O_5-K_2O$), (III) $2.1Mg\;ha^{-1}$ of pig manure $>+80-37kg\;ha^{-1}$ of $N- K_2O$ as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (IV) $4.2Mg\;ha^{-1}$ of pig manure+ $62-3kg\;ha^{-1}$ of $N-K_2O$as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (V) $10Mg\;ha^{-1}$ of pig manure+ Treatment(II), (VI) $20Mg\;ha^{-1}$ of pig manure +Treatment(II). Number of tillers in treatment (I) were higher than other treatments in tillering and panicle formation stage. After heading stage, treatments (V) and (VI) have higher number of tillers, but treatment (III) and (IV) have fewer number of tillers during all growing stage. Uptake of NPK in rice plants was higher in treatment (VI), but the efficiency of N, P and K was higher in treatment (I), (III) and (IV). The yield of unhulled rice were in order of tretments (VI)>(V)>(IV)>(II)>(III), although the difference was not statistically significant. Inorganic nitrogen, available P and exchangable K contents in soil were highest at tillering stage in all treatments and became low from panicle formation to harvest stage. Available P in soil was increased by the application of pig manure upto 20 cm depth. Exchangeable cation contents in 40 to 60 cm soil depth was much higher in treatment (VI) than in other treatments. Treatment (V) and (VI) showed much higher losses of N. $P_2O_5 $ and $K_2O$ than other treatment. Though treatment (VI) tended yield higher than in other treatments, showed lodging and occurrence of leaf and neck blast in this treatment. Yield of unhulled rice in treatment (IV) was not significant statistically and reduced nutritional losses. It is conclude that treatment (IV) seems to be the most reasonable one for the application of pig manure in combination of chemical fertilizers.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.3
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• pp.193-202
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• 2003

Objective: To evaluate the difference of implantation rate (IR) and clinical pregnancy rate (CPR) between two protocols of endometrial preperation in women undergoing frozen-thawed embryo transfer (FET) cycles. Methods: This study was performed during the different time periods: A retrospective study from January 2000 to June 2001 (phase I) and a prospective study from July 2001 to March 2002 (phase II). All the patients received estradiol valerate (6 mg p.o. daily) starting from day 1 or 2 of the menstrual cycle without pituitary down regulation. Progesterone was administered around day 14 after sonographic confirmation of endometrial thickness $\geq$7 mm and no growing follicle. In Group A (n=88, 99 cycles) of phase I, progesterone was administered i.m. at a dose of 50 mg daily from one day prior to thawing of pronuclear (PN) stage frozen embryo or three days prior to thawing of 6-8 cell stage frozen embryo and then each stage embryos were trasnsferred 2 days or 1 day later after thawing. In Group B (n=246, 299 cycles) of phase I, patients recieved progesterone 100 mg i.m. from one day earlier than group A; two days prior to PN embryo thawing, four days prior to of 6-8 cell embryo thawing. During the phase II, to exclude any differences in embryo transfer procedures, in Group 1 (n=23, 28 cycles) of phase II embryo was transfered by one who have used the progesterone protocol since the phase I. In Group 2 (n=122, 139 cycles) of phase II embryo was transfered by one who use the progesterone protocol from the phase II. Results: When compared across the phase and group, there were no significant differences in the characteristics. During the phase I, there were significant increase in IR (14.4% vs 5.9%, p=0.001) and CPR (28.3% vs 14.5%, p=0.000) in group A. During the phases II, IR (11.8% vs 10.6%) and CPR (27.6% vs 27.3%) show no differences between two groups. Conclusions: In FET cycles, IR and CPR are increased significantly by the change of dosage and timing of progesterone administraton. And the timing is considered to be more important factor because the dosage of progesterone did not affect implantation window in previous studies. Therefore, we suggest that progesterone administration in FET cycle should begin from one day prior to PN stage embryo thawing and three days prior to 6-8 cell stage embryo thawing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.266-280
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• 1989

Gonadal maturation of the Korean pomfrets, Pampus echinogaster (Basilewsky) and Pampus argenteus (Euphrasen) were histologically investigated based on the samples captured in the East China Sea from January 1987 to December 1988. Gonadosomatic index (GSI) of P. echinogaster began to increase from March, and reached maximum between May and July. It began to decrease from July and reached mini-mum between August and February. P. argenteus had a similar cycle, however, P. argenteus has higher values in April than P. echinogaster. Hepatosomatic index (HSI) were positively related to GSI. HIS of P. echinogaster and P. argenteus reached maximum in $April\~July$ and $April\~August$, respectively, Fatness coefficient of two Pampus species were low in the summer, and high in the winter. Ovary is of saccular structure, and testis is of lobular structure. From February, the early oocyte (ca. $100\mu$ in diameter grows) rapidly at the germinal epithelium of ovarian sacs. From March to April the oocytes grew up to cu $400\~500\mu$ in diameter. At this stage, the yolk globules are accumulated rapidly in the cytoplasmic layer. From May, the oocytes roached ca. $650\~850\mu$ in diameter, and they are spawned in $May\~July$. After spawning the residual follicles and remained ripe eggs degenerate. From February, spermatogonia grows into spermatocyte on the epithelium of the testicular lobuli. From May, spermatozoa appeared and spawning occurs. After spawning, the epithelium is thickened and the remained spermatozoa degenerate. Annual reproductive cycle of two Pampus species could be divided into four successive stages: Growing stage ($March\~April$), Mature stage ($April\~May$), Ripe and spent stage ($June\~July$) and Recovery and resting stage ($August\~January$). Absolute fecundity of P. echinogaster was $9,441\~135,294$, and that of P. argenteus was $50,678\~221,894$. Absolute fecundity of two Pampus species were positively related to body length and total weight. Relative fecundity was positively related to body length, while it was reversely related to total weight. The increasing rate of absolute fecundity of P. echinogaster was lower than P. argenteus. In P. echinogaster half of female and male reached first maturity at body length of $15.0\~$17.9cm and $12.0\~14.9cm$, respectively. All of females and males reached first maturity at body length of $18.0\~20.9cm$ and $21.0\~23.9cm, respectively. In P. argenteus all of females and males reached first maturity at body length of 18.6cm and 16.7cm$, respectively.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.149-154
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• 2005

It is very important to make shorter and healthier pot plants with increased numbers of branch at a growing stage before short-day exposure. Especially light and nutrient conditions directly affect the growth and quality of the plants as described above. In this study, the effects of nutrient strength and light intensity on the nutrient uptake and growth of young Kalanchoe plants (Kalanchoe blossfeldiana 'Marlene') during this growth stage were investigated. The plants were grown under two radiation integral (15.8 and 7.9 $mol{\cdot}m^{-2}{\cdot}d^{-1}$, PPF) and three EC (0.8, 1.6 and 2.4 $dS{\cdot}m^{-1}$) conditions. Leaf area, fresh weight, dry weight and number of branch were higher at a higher PPF, and this tendency was more evident at an EC above 1.6$dS{\cdot}m^{-1}$. The plants became higher at a lower PPF. When the EC was at 0.8 $dS{\cdot}m^{-1}$, the plants did not grow so healthy regardless of PPF conditions. EC decrement in the nutrient solution was increased with increase of nutrient strength. With growth stage, the nutrient uptake was increased with increases of nutrient strength and PPF. At a higher PPF, $NO_3-N,\;K^{+}\;and\;Ca^{2+}$ were much more absorbed, and especially the uptake of $K^{+}$ was 1.1 to 1.5 times greater than that or $NO_3-N$. From the results, the EC needed above 1.6 $dS{\cdot}m^{-1}$ during the seedling stage in order to make more healthy Kalanchoe plants having more leaf area, fresh weight, dry weight and number of branches under adequate light conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.205-216
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• 2010

Few spring sowing have been conducted on winter cereal crops for whole-crop silage use. Experiments were conducted during 2007 and 2008 at the Chungnam Agricultural Research & Extension Services. The objectives of this study were compared the spring sowing with the optimum season's sowing on growth, yield and feed quality in five winter cereal crops. The treatments consisted of 5 winter cereal crops, Youngyang (Barley, Spring habit I), Keumkang (Wheat, Spring habit II), Gogu(Rye, Spring habit estimated III), Shinyoung (Triticale, Spring habit estimated III), Samhan(Oat, Spring habit estimated II), and 3 planting dates, 18 October (optimum season's sowing), 23 February and 10 March in spring. Heading days as affected by spring sowing compared to optimum season sowing were delayed by 16~20 days in barley, wheat, rye and triticale, and 9 days in oat. The clipping dates at the optimal harvesting stage of each crop for round-baled silage in spring sowing was 8 June (yellow ripe stage) in barley, 25 May (10 days after heading) in rye, and 17 June in wheat (yellow ripe stage), triticale (milky stage) and oat (milky stage). The accumulative temperature from emergence to heading was significantly decreased as affected by spring sowing compared to optimum season's sowing, but that of sowing to emergence and that of heading to maturing was similar. The rate of spikes per tillering surveyed at each clipping date was 62.0-73.1 percent in barley, wheat, triticale and oat, and 56.0 percent in rye compared to that of optimum season sowing. The dry matter yield in spring sowing compared to 18 October was obtained about 71.7 percent in barley, 60.6 percent in wheat, 46.2 percent in rye, 70.2 percent in triticale and 110.9 percent in oat. It were increased in acid detergent fiber (ADF), neutral detergent fiber (NDF) and crude protein content, but decreased in digestible dry matter content(DDM) and relative feed value (RFV). The yield of DDM by spring sowing was decreased in barley, wheat, rye and triticale, but increased in oat. The yield of dry matter and DDM were higher in oat and triticale than that of barley, wheat and oat. So, regardless to clipping dates and cropping system, the appropriated crop for spring sowing was oat, and subsequently triticale and barley. It was not adopted for spring sowing in rye because of low rate of no. of spikes per tillers and yield. It was necessary eliminated winter growing nature by earlier sowing at the late of February after overwinter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.145-150
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• 1986

The experiments were conducted to study the influence of growth location and cutting microelements macro-and on managements in temperate grasses in Korea and West Germany from 1975 to 1979. The field trials were designed as split plot with three grass species of Dactylis glomerata L., Lolium perenne L. and Festuca pratensis Huds under three cutting regimes at grazing stage, silage stage and hay stage. The results obtained are summarized as follows: 1. Concentrations of macro-and microelements in temperate grasses showed a different response to growth location and growing season. P concentration in the plants was decreased under hot stress in summer, whereas Mg and Na tended to be increased. The seasonal changes in K and Zn were not significant. 2. Morphological growth stage was to be found as an important factors influenced to mineral components. P and K contents in temperate grasses tended to be decreased as morphological development especially under high temperature in Suweon and Cheju. Ca and Mg were less affected by morphological stage and cutting managements. 3. Mean value of Ca/P ratio in the plants were 1.58, 1.33 and 1.21 for meadow fescue, perennial ryegrass and orchardgrass, respectively. Ca/P ratio in grasses tended to be increased as morphological development. 4. Zn deficiency in the plants occured in all grass species and experimental sites. Mean Zn concentration of the plant were 34.2%, 31.2% and 37.8% for Suweon, Cheju and Taekwalyong, respectivelly. Na deficiency occured in orchardgrass and meadow fescue, especially in taekwalyong. Cool temperature resulted in a decrease of Na absorption and accumulation.

• 대한공업교육학회지
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• v.44 no.2
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• pp.104-122
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• 2019

In the era of the fourth industrial revolution, maker education is drawing attention as a method of student-led education. At a time when interest in maker education is also growing in technology education, figuring out what stage of concern(SoC) a middle school technology teacher is critical to effective implementation. This study analyzed SoC in maker education by layer sampling among 400 middle school technology teachers using Concerns-based adoption model. SoC was then obtained by measuring the origin using the SoCQ and then presenting it as a SOCQ profile. Gender, training experience with two lower variables were analyzed using t verification, working cities, teaching experience with more than three lower variables were analyzed using one-way ANOVA. Studies showed that SoC in maker education of middle school technology teachers showed the most similar characteristics to that of non-users. The difference in concern depending on gender was that male teachers were more concerned in maker education than female teachers. The difference in concern depending on the working city was that teachers working in the township were more concerned in the maker education than teachers working in the large city, and the difference in concern depending on the teaching career was higher among teachers with middle experience than those with low and high experience. There was also a higher stage of concern in maker education than in teachers without training experience. Therefore, it is necessary to provide middle school technology teachers with an introduction to the maker education and various information, teaching, learning and evaluation data to enhance overall concern and to support the use and evaluation of the maker education in the classroom by providing various teacher training and consulting on the maker education in the future. Further, through further study, we should conduct study that analyzes both Stage of Concern, Level of Use and Innovation Configuration, to put in the effort for effective settlement of maker education.