• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.463-468
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• 2013

The level of nitrous oxide ($N_2O$), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic source, especially application of nitrogen fertilizers. Quantifying $N_2O$ emission from agricultural field is essential to develop national inventories of greenhouse gases (GHGs) emission. The objective of the study was to develop emission factor to estimate direct $N_2O$ emission from agricultural field in Gangwon-do, Korea by measuring $N_2O$ emissions from potato (Solanum tuberosum), red pepper (Capsicum annum L.), and Chinese cabbage (Brassica campestris L.) cultivation lands from 2009 to 2012. Accumulated $N_2O$ emission was $1.48{\pm}0.25kg$ $N_2O-N\;ha^{-1}$ for red pepper, $1.27{\pm}0.27kg$ $N_2O-N\;ha^{-1}$ for potato, $1.49{\pm}0.06kg$ $N_2O-N\;ha^{-1}$ for Chinese cabbage cultivated in spring, and $1.14{\pm}0.22kg$ $N_2O-N\;ha^{-1}$ for fall Chinese cabbage. Emission factor of $N_2O$ calculated from accumulated $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0051{\pm}0.0016kg$ $N_2O-N\;ha^{-1}$ N for cropland in Gangwon province. More extensive study is deserved to be conducted to develop $N_2O$ emission factor for upland crops in Korea through examining the emission factors from various regions and crops because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.127-135
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• 2002

Water quality samples were taken for every two hours whenever runoff occurred by rainfall to investigate concentration variations of T-N, T-P and SS during runoff process from a paddy field. The difference between the highest concentration in a runoff event and flow weighted mean concentration for T-N, T-P, SS placed between 3.07∼40.16%, 11.44∼60.80%, and 15.11∼64.5%, respectively. The difference between the lowest concentration in event and event mean concentration for T-N, T-P, SS ranged between -7.24∼-31.84%, -11.59∼-47.86%, and -5.21∼-36.20%, respectively. The relationship between runoff and mass load was derived for each storm event using observed data. The relationship between runoff and mass load showed linear relationship regardless of water quality constituents and rainfall amount. The results suggested that relationship between T-N and T-P loads and runoff should be prepared separately in considering of fertilization effect and seasonal conditions. The relationship between SS and runoff should be made to reflect seasonal conditions and tillage effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.676-683
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• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.30-34
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• 2006

The effect of N-fertilization on yield, milling characteristics and quality of Samcheonbyeo, an early maturing rice variety, was investigated in 2002 to 2004. The study was carried out in the southern alpine area of Un-bong Sub-Station, Honam Agricultural Research Institute. Higher nitrogen levels increased number of panicle and grain per unit area, but lowed ripening rate and decreased 1,000-grain weight. Higher nitrogen levels of up to 90 kg/ha also increased head rice yield. A nitrogen level of 90 kg/ha was found optimal for increasing ripening rate and head rice yield, and rice palatability.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1661-1669
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• 2013

This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource. As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of $COD_{Mn}$ runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.186-192
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• 2011

Objective: Since IVF program was first established, various types of media and culture systems have been developed either in-house or commercially. The aim of this study was to compare the efficacy of in-house Maria Research Center (MRC) media to that of commercially available Sydney IVF media in human day 3 embryo transfer cycles. Methods: Three hundred sixty nine couples were included in this prospective, randomized, and comparative study. All couples undergoing IVF treatment at the Maria Fertility Hospital were randomly assigned to either Sydney IVF (n=178) or MRC (n=191) media. Results: No difference was observed between the MRC media and Sydney IVF media groups with respect to fertilization rate (74.4% vs. 75.5%). The clinical pregnancy and implantation rates of MRC media (47.1% and 20.0%, respectively) were also similar to those of Sydney IVF media (44.4% and 19.4%, respectively). However, the proportion of embryos with good quality on day 3 was significantly higher in the MRC media group than the Sydney IVF media group (50.2% vs. 43.2%) ($p$ <0.05). Conclusion: MRC media were as effective as Sydney IVF media for sustaining embryo development and pregnancy rates. The present study implies that MRC media can be a suitable alternative to commercially available media for human IVF-ET program.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.136-142
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• 2015

Objective: Smoking has been reported to harm nearly every organ of the body, but conflicting results have been reported regarding the effects of smoking on assisted conception. In this prospective cohort study, we aimed to investigate the prevalence of positive urinary cotinine tests in infertile couples and whether cotinine positivity was associated with infertility treatment outcomes. Methods: A qualitative urinary cotinine test was administered to 127 couples who underwent in vitro fertilization (IVF, n=92) or intrauterine insemination (IUI, n=35). Results: The overall prevalence of positive urinary cotinine test was 43.3% (55/127) in the male partners and 10.2% (13/127) in the female partners with similar prevalence rates in both genders in the IUI and IVF groups. Semen characteristics, serum markers of ovarian reserve, and number of retrieved oocytes were comparable among cotinine-positive and cotinine-negative men or women (with the exception of sperm count, which was higher among cotinine-positive men). The results of urinary cotinine tests in infertile couples were not associated with IVF and IUI outcomes. Conclusion: The presence of cotinine in the system, as indicated by a positive urinary cotinine test, was not associated with poorer outcomes of infertility treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1747-1755
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• 2018

Objective: Common reed (Phragmites communis Trin.) could potentially provide an alternative resource for silage; however, its silage quality is poor. The aim of this study was to investigate the factors in reed that contribute to poor quality and determine how the use of additives at ensiling could improve fermentation quality. Methods: In Experiment 1, we determined the chemical composition and the presence of indigenous lactic acid bacteria (LAB) in reed. We further examined fermentation quality of reed silage under conditions without additives (NA) and treated glucose (G), lactic acid bacteria (L), and their combination (G+L). In Experiment 2, silage of NA, and with an addition of cellulase and lactic acid bacteria (CL) were prepared from harvested reed. The harvested reeds were fertilized at nitrogen concentrations of 0, 4, 8, and $12g\;N/m^2$ and were harvested thrice within one year. Results: The indigenous LAB and fermentable carbohydrates are at extremely low concentrations in reed. Reed silage, to which we added G+L, provided the highest quality silage among treatments in Experiment 1. In Experiment 2, N fertilization had no negative effect on silage quality of reed. The harvest times decreased fermentable carbohydrate content in reed. The CL treatment provided a higher lactic acid content compared to the NA treatment. However, the quality of CL treated silage at the second and third harvests was significantly lower than at the first harvest, due to a reduction in carbohydrates caused by frequent harvesting. Conclusion: The causes of poor quality in reed silage are its lack of indigenous LAB and fermentable carbohydrates and its high moisture content. In addition, reed managed by frequent harvesting reduces carbohydrate content. Although the silage quality could be improved by adding CL, higher-quality silage could be prepared by adding fermentable carbohydrates, such as glucose (rather than adding cellulases).

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.53-59
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• 2006

This study was carried out to obtain the biological studies on aquaculture fundamental data for the resources annexation of Miichthys miiuy in terms of the characteristics of the spawning and effect of salinity. The adults spawners in 5 years were TL $72.3\sim89.6\;cm$, BW $3,736\sim8,818\;g$ in female (n=39), TL $47.1\sim81.2\;cm$, BW $716.6\sim6,853\;g$ in male (n=24). The adults size which were suitable for a stable egg collection were $97.9\sim110.2\;cm$ in total length, $9,657\sim13,200\;g$ in body weight. Each egg contained $1\sim5$ oil globules. Also, the highest hatching rate was 96.7% at the one having an oil globules. The highest hatching rate was 87.0% at 30.0 ppt. The fastest time required from fertilization to hatching was 17 hours 24 minutes at 28.0 ppt.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.4
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• pp.240-246
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• 2016

Objective: The study aimed to investigate the efficacy of intrauterine instillation of granulocyte colony-stimulating factor (G-CSF) on the day of ovulation triggering or oocyte retrieval in infertile women with a thin endometrium. Methods: Fifty women whose endometrial thickness (EMT) was ${\leq}8mm$ at the time of triggering during at least one previous in vitro fertilization (IVF) cycle and an index IVF cycle were selected. On the day of triggering (n = 12) or oocyte retrieval (n = 38), $300{\mu}g$ of G-CSF was instilled into the uterine cavity. Results: In the 50 index IVF cycles, the mean EMT was $7.2{\pm}0.6mm$ on the triggering day and increased to $8.5{\pm}1.5mm$ on the embryo transfer day (p< 0.001). The overall clinical pregnancy rate was 22.0%, the implantation rate was 15.9%, and the ongoing pregnancy rate was 20%. The clinical pregnancy rate (41.7% vs. 15.8%), the implantation rate (26.7% vs. 11.7%), and the ongoing pregnancy rate (41.7% vs. 13.2%) were higher when G-CSF was instilled on the triggering day than when it was instilled on the retrieval day, although this tendency was likewise not statistically significant. Aspects of the stimulation process and mean changes in EMT were similar in women who became pregnant and women who did not. Conclusion: Intrauterine instillation of G-CSF enhanced endometrial development and resulted in an acceptable pregnancy rate. Instillation of G-CSF on the triggering day showed better outcomes. G-CSF instillation should be considered as a strategy for inducing endometrial growth and good pregnancy results in infertile women with a thin endometrium.