• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.117-123
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• 1968

A simplest and best method to find out lime requirement for Korean soils is described. Twenty six top soil samples were collected from various localities and chemical characteristics were dertermined. Three different buffer curve methods were employed as the standard to find out the most reliable test for lime requirement. In addition, the lime requirement test by the Shoemaker's and Woodruff's as well as the O.R.D. kit method were compared with the most reliable buffer curve method. The results may be summarized as follows. 1. The regression equation of the most reliable lime requirement by buffer curve method, y, on percent base saturation of various soils, X, was y=9.69-0.106 X and the negative correlation coefficient r=-0.84 was statistically significant at 5% level. 2. Lime requirement test by the best, buffer curve, method was more well correlated with the sum of exchangeable hydrogen and exchangeable aluminum contents of the soil samples than the exchangeable hydrogen content only. 3. The ordinary buffer curve method for lime requirement is more reasonable than the lime requirement test by the buffer curve prepared after addition of 1 normal potassium chloride or calcium chloride solutions. 4. The lime requirement tests by the most reasonable buffer curve method, X, and by the Woodruff's, the Shoemaker's and O.R.D. kit were compared. The best method for laboratory lime requirement test was the Shoemaker's method and the O.R.D. kit method also was good enough for the field test and these two method are recommended as the unified method of lime requirement test in each soil testing laboratories throughout Korea.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.73-78
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• 2018

BACKGROUND: Soil salinity of reclaimed tidal land in Korea is highly important factor. High salinity is harmful to crop productivity. Jerusalem artichoke (Helianthus tuberosus L.) is known to be salt-tolerant and has high adaptability to diverse pedo-climatic conditions. The objective of this study was to assess the changes of soil properties and crop productivity according to salt concentration in the reclaimed tidal lands. METHODS AND RESULTS: Experimental sites were selected at Saemangeum ($35^{\circ}46^{\prime}N$, $126^{\circ}37^{\prime}E$) reclaimed tidal land, and their dominant soil series were Munpo (coarse loamy, mixed, non-acid, mesic, typic Fluvaquents). H. tuberosus L were collected from 12 locations across Korea. Tubers were planted at $75{\times}25cm$ with EC 2 to $7dS\;m^{-1}$. Soil samples were periodically collected from both 0~20 cm and 20~40 cm depths of each site. Soil salinity and soil moisture contents were varied depending on weather conditions. Soil electrical conductivity varied from 1.0 to $5.9dS\;m^{-1}$, and soil moisture contents varied from 9.2 to 28.7%. The white-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' exhibited the highest height (207 cm), followed by the white-colored tubers of H. tuberosus L. collected from 'Iksan-si'(202 cm). The white-colored tubers of H. tuberosus L. collected from 'GyeongJu-si' showed the highest yield (549 kg/10a). The purple-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' showed the highest yield (615 kg/10a). CONCLUSION: Our results indicate that the plant height and tuber yield did not appear to be correlated. Considering yield and inulin content, the GyeongJu-si seemed to be suitable as the white-colored tubers of H. tuberosus L. and the Yeongwol-gun seemed to be suitable as the purple-colored tubers of H. tuberosus L. in the reclaimed tidal lands. However, it is necessary to consider the relationship between the inulin content and the yield.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1447-1456
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• 2015

Olive flounder (Paralichthys olivaceus) including red seabream (Pagrus major) and jacopever (Sebastes schlegeli) were known to be suitable characteristics for preparing a processed food because of white meat fish containing low fat in muscle. In this study, the physicochemical properties of olive flounder (46-50 cm of length, 950-1,050 g of weight), red seabream (30-33 cm of length, 1,250-1,350 g of weight) and jacopever (20-23 cm of length, 550-650 g of weight) were studied to obtain a basic data for the development of a new processed food. Head, scale, bone and viscera of each samples were removed, and then grinding with homogenizer before experiment. Moisture content of red seabream is lower than that of olive flounder and jacopever, therefore, crude protein and crude lipid are higher content. Red seabream showed higher redness, yellowess and color difference value than those of olive flounder and jacopever except lightness. The major total amino acid in olive flounder, seabream and jacopever were glutamic acid, lysine and aspartic acid in order. Especially, the highest content of free amino acid was lysine for olive flounder and jacopever and alanine for red seabream. The highest content of mineral in olive flounder, seabream and jacopever was potassium (K) and then phosphorous (P) and sodium (Na) in order. The highest amount of fatty acid in olive flounder, red seabream and jacopever was polyenoic acid in which especially contained 6.8, 7.1 and 6.7% for EPA, and 15.2, 15.2 and 17.1% for DHA, respectively. From the result of sensory evaluation, there was no significant difference in color and odor, but not in taste and texture.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.66-75
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• 2008

This study examined the influence of the apical sizes on the sealing ability of a root canal filling. Thirty-six single rooted teeth with a single canal were divided into 3 groups (n = 12) and instrumented with either the $Profile^{(R)}$ or $LightSpeed^{(R)}$ system to achieve three different apical sizes (master apical file [MAF] of #25, #40, or #60). The teeth were filled with gutta perch a using a modified continuous wave technique. The level of microleakage was determined by immersing ten teeth from each group into India ink for 1 week followed by clearing with nitric acid, ethyl-alcohol, and methylsalicylate. The microleakage was measured using vernier calipers. The data was analyzed statistically using Kruskal-Wallis one-way ANOVA and a Student-Newman-Keuls Method. Two teeth from each group were sectioned horizontally at 1, 2, 3 and 4 mm from the apex in order to observe a cross section. The apical size was significantly (p < .05) influenced the level of microleakage. In the Student-Newman-Deuls Method, MAF sizes of #25 and #40; and MAF sizes of #25 and #60, respectively showed a statistically significant difference. There was no significant difference between #40 and #60. In most cross sections, oval-shaped canals were observed, and the irregularity of the internal surface increased with decreasing apical size. There was also an increase in the area of recess, which is the area where the canal space is not filled with either gutta-percha or sealer. When the root canals are filled using a modified continuous wave technique, canal filling with more consistent and predictable outcome may be expected as the apical preparation size is increased.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.77-81
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• 2008

Introduction: REM sleep which shows characteristic muscle atonia and increased resistance of upper respiratory track is known to be vulnerable to sleep apnea. Previous studies reported that REM sleep-dependent (or related) obstructive sleep apnea syndrome (REM-dependent OSA) could be one of sleep disordered breathing. The present study aimed to investigate clinical findings and polysomnographic variables of REM-dependent OSA. Methods: Fifty-six patients diagnosed with mild to moderate obstructive sleep apnea by overnight polysomnography (5$53.7{\pm}16.7$ years, 42 males). REM-dependent OSA was defined as AHI-REM/AHI-NREM ratio>2. We compared clinical and polysomnographic findings between REM-dependent OSA and No REM-dependent OSA patients. Results: Among 56 patients, 37.5% (n=21, average age of $52.3{\pm}19.7$ years, 14 males) met the REM-dependent OSA criteria. There were no significant differences in age, sex and body mass index between two groups. After controlling for age, sex, body mass index and periodic leg movements index, REM-dependent OSA patients showed significantly lower AHI, lower number of oxygen desaturation events and higher stage 2 sleep proportion compared to No REM-dependent OSA patients (p=0.010, p=0.006, p=0.031, respectively). After controlling for age, sex, body mass index and periodic legs movements index, AHI-REM was positively correlated with the number of oxygen desaturation events in REM-dependent OSA group (p=0.002). Conclusion: Current results suggested that 37.5% of patients with mild to moderate severity of obstructive sleep apnea could be classified into REM-dependent OSA. REM-dependent OSA was more common in mild severity of OSA, equally prevalent in both sexes and accompanied with sleep architecture changes, i.e. increased proportion of stage 2. In addition, apneic events during REM sleep in REM-dependent OSA were related to oxygen desaturation.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.1-7
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• 2009

This study was performed to evaluate the effect of the level of stocking density of housing with or without window on chicken meat quality. The incidence of $1^+$ grade of whole chicken housed with window significantly influenced by stocking density. The incidence of $1^+$ grade chicken at high stocking density ($0.050\;m^2$/head), standard stocking density ($0.066\;m^2$/head), and low stocking density ($0.083\;m^2$/head) was 26, 52, and 66%, respectively. Breast muscle of chicken housed with window and with low stocking density showed higher incidence of $1^+$ grade than high stocking density. Also minor and severe PSE (pale, soft, extractive) incidence of chicken meat were showed 4% each, while the $1^+$ grade chicken was not appeared at low density. In chicken thigh, the incidence rate was not affected by stocking density. In chicken housed without window, the incidence of $1^+$ grade chicken in high, standard, and low stocking density was 18, 8, and 46%, respectively. Also, the incidence of $1^+$ grade chicken breast was 2.6 times higher than the chicken in low stocking density. However, incidence of $1^+$ grade thigh was not affected by the stocking density. These results suggest that high stocking density significantly reduced the incidence of $1^+$ grade chicken meat regardless of housing with or without window.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.464-474
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• 2006

The paleoceanography since 14 ka was reconstructed based on the planktic foraminiferal assemblages of core sediments from the outer shelf of the Korea Strait. Planktic foraminifera in the core sediments can be divided into four assemblages: A, B, C, and D. Assemblage A consists mainly of Globigerinoides ruber group and Globigerinoides conglobatus with low abundance (less than 10%), indicating the tropical-subtropical water mass. Assemblage B is composed of Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, the indicator of Kuroshio Current, and shows the aspect of the inflow of the Tsushima Current into the Korea Strait. Assemblage C yields polar-subpolar species, mainly Neogloboquadrina incompta and N. pachyderma. It decreases upward of the core. Assemblage D contains coastal water species such as Globigerina bulloides and G. quinqueloba. It is abundant in the lower to middle region of the core. From the analysis of distributions of each assemblage and the result of age datings in the core, it is suggested that the Korea Strait played a role of channelling the East China Sea and the East Sea after the LGM (ca. 14 ka). During this time, the coastal water, affected by fresh waters originated from the river systems of China and/ or the Korean Peninsula, flourished around the Korea Strait and theses coastal water might entered to the East Sea. Around 8.5 ka, the effect of the Tsushima Current started to strengthen in this region, and the present current system seems to be formed at about $7{\sim}6ka$.

• Journal of Nutrition and Health
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• v.35 no.3
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• pp.296-302
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• 2002

This study was designed to investigate the effects of a butanol extract of pine needles (Pinus densiflora Sieb et Zucc) on lipid metabolism and oxidative stress in rats. Twenty-eight male Sprague-Dawley (SD) rats were divided into four groups over a 45 days study period: the control group on a basic diet, and three experimental groups on three different dietary levels of the butanol fraction, specifically 25 mg (BuOH-25), 50 mg (BuOH-50), and 100 mg (BuOH-100) butanol fraction/kg body weight/day, thereby 0.025%, 0.05%, 0.1% of butanol extract of pine needles was added to basic diet respectively. At the end of the experimental period, body weights and food intakes were food intakes were not different among the four groups. Total and LDL-cholesterol levels were markedly decreased in the BuOH-25, BuOH-50, and BuOH-100 groups, respectively, as follows: 12.8%, 19.1% and 21.6% reductions in total cholesterol; and 10.2%, 15.6% and 23.7% reductions in LDL-cholesterol. However, HDL-cholesterol levels were significantly increased (by approximately 20%) in the serum of the BuOH-100 group only, compared with the control and other experimental groups. Atherogenic indices were also markedly decreased in the three experimental groups, by 24.8%, 30.4% and 36.2%, for each of the BuOH-25, BuOH-50, and BuOH-100 groups, respectively, compared with the control group. The levels of the hydroxyl radical (·OH) and of lipid peroxide (LPO) in the serum of the three experimental groups were significantly reduced, by 9.8%, 19.7% and 21.2%; and by 13.3%, 13.3% and 16.7%, for the BuOH-25, BuOH-50, and BuOH-100 groups, respectively Significant increases in serum superoxide dismutase (SOD) were observed in the BuOH-50 and BuOH-100 groups; specifically, 12.1% in the BuOH-50 group and 23.3% in the BuOH-100 group, compared with the control group. Significant increases in catalase (CAT) avtivities, of 24.7% in the BuOH-50 group and 29.2% in the BuOH-100 group, were also observed, compared to the control group. These results suggest that a butanol extract of pine needles could inhibit chronic degenerative disease through improving lipid metabolism, and could also effectively modulate the aging process attenuating oxidative stress.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.215-221
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• 2002

Antioxidants(N-acetyl-1-cysteine, ebselen and glutathione) and growth factors(EGF, PDGF) were studied as a mean of increasing the development of porcine embryos produced by in vitro maturation (IVM) and in vitro fertilization(IVF). Porcine embryos developed to the 2~8 cell stage after IVF were cultured fer 6 to 7 days at 38.5$^{\circ}C$ in NCSU 23 medium containing antioxidants plus growth factors. Cell numbers of blastocysts were counted by fluorescence staining method. The developmental rate beyond morula stages in NCSU 23 containing NAC(1nm) or NAC(1nm) plus EGF(100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 28.1, 32.3 and 35.3%, respectively. NAC plus PDGF group was slightly higher than control group(P>0.05). The developmental capacity in NCSU 23 containing ebselen(10 $\mu$M) or ebselen(10 $\mu$M) plus EGF(100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 17.8, 36.9 and 40.3%, respectively Ebselen plus growth factor groups were significantly higher than control group(P<0.05). The developmental capacity in NCSU 23 containing glutathione(100 $\mu$M) or glutathione(100 $\mu$M) plus EGF (100ng/$m\ell$) or PDGF(5ng/$m\ell$) were 24.1, 30.5 and 27.7%, respectively. There were not difference in all experimental groups(P>0.05). In all experimental groups, there was no significantly differences on the cell number of blastocysts, but ebselen plus growth factor groups were significantly higher than control group. These studies indicate that antioxidants plus growth factors can increase the proportion of embryos that developed beyond morulae stage.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.8-8
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• 1987

This paper describes on the distribution of the vibration and the noise produced on a skipjack pole and line training ship M/S Pusan 403 (243GT, 1,000ps) under the cruising or drifting condition. The vibration and the noise level were measured by use of protable vibration analyzer (B and K 3513) and sound level meter (B and K 2205), and so the vibration level was converted into dB unit. The check points were set through every decks and around important places of the ship. The results obtained can be summarized as follows: 1. The vibration and the noise level 1) On the main deck, both the vibration and the noise level were highest at the vertically above the main engine, whereas the vibration level was the lowest in the bow store and the noise level beneath the bridge. 2) Under cruising condition, the vibration level around the cylinder head of main engine, port side of the engine room, on the shaft tunnel was 80, 67, 65 dB and the noise level 104, 87, 86 dB, respectively. 3) The vibration level on the vertical line passing through the bridge was the highest at the orlop deck with 60 dB and the lowest on the bridge deck with 55 dB, whereas the noise level the highest at the compass deck with 75 dB and the lowest at the orlop deck with 53 dB. 4) The vibration and the noise level on the open decks were the highest with 65 dB and 84 dB on the boat deck, whereas the vibration level was the lowest at the lecture room with 51 dB and the noise level the lowest at the fore castle deck with 57 dB. 5) On the orlop decks, both the vibration and the noise level were the highest at the engine room with 65 dB and 85 dB, and the lowest at bow store with 54 dB and 52 dB, respectively. Comparing with the vibration level and the noise level, the vibration level was higher than the noise level in the bow part and it was contrary in the stern part of the ship. 2. Vibration analysis 1) The vibration displacement and the vibration velocity were the greatest at the cylinder head of main engine with 100μm and 11mm/sec, and were the smallest at the compass deck with 3μm and 0.07mm/sec. They were also attenuated rapidly around the frequency of 100Hz and over. 2) The vibration acceleration was the greatest at the cylinder head with the main frequency of 1KHz and the acceleration of 1.1mm/sec super(2), and the smallest at the compass deck with 30KHz and 0.05mm/sec super(2).