• Korean Journal of Weed Science
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• v.10 no.2
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• pp.83-92
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• 1990

Experiment was conducted to establish the weed control system on the paddy fields by investigating species, period and amount of weeds in Gangwon province. Four locations were selected for these experiments : West plain area, Chunchon(74m above the sea level), mid-mountainous area, Hongchon(300 m), high alpine area, Hoengsong(450m), and east sea area, Myungju(14m). Weed emergence was investigated 6 times from 10 days after transplanting to 60 days with 10 days interval. From the experiments stated above, the results were summarized as follows ; The identity of weed species was small in grass family, but broad-leaf family was numerous. Also the dominant weed species was generally the perenial weeds. The weed emergence was initiated from 10 days after translanting. The amounts of weed counted the most in Chunchon. A large number of weeds were emerged between 30-60 days after transplanting in Chunchon and between 40-60 days after transplanting in Hongchon and Hoengsong. Among agronomic characteristics affected by weed emergence during rice development, plant height was decreased by 2~4cm, panicle number by 1.3~2.9, spikelet by 3.7~7.5, ripening rates 3.3~6.5%, and milled yield by 12~17%, respectively.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.815-821
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• 2006

Background: Carotid endarterectomy is an effective treatment modality in patients with severe carotid artery stenosis, but it may result in serious postoperative complications, We analyzed the results of the carotid endarterectomy performed in our institution to reduce the complications related to the card endarterectomy. Material and Method: We analyzed retrospectively the medical records of 74 patients(76 cases) who underwent carotid endarterectomy for carotid artery stenosis by a single surgeon from February 1996 to July 2004. Result: There were 64 men and 10 women. The mean age of the patients was 63.6 years old. Carotid endarterectomy only was performed in 63 cases, carotid endarterectomy with patch angioplasty in 8 cases, and carotid endarterectomy with segmental resection of internal carotid artery and end to end anastomosis in 5 cases. Intra-arterial shunt was used in 29 cases. The mean back pressures of internal carotid arteries checked after clamping common carotid arteries and external carotid arteries were $23.48{\pm}10.04$ mmHg in 25 cases with changes in electroencephalography(group A) and $47.16{\pm}16.04$ mmHg in 51 cases without changes in electroencephalography(group B). There was no statistical difference in the mean back pressure of internal carotid arteries between two groups(p=0.095), but the back pressures of internal carotid arteries of all patients with changes in electroencephalography were under 40 mmHg. When there was no ischemic change of electroencephalography after clamping common carotid artery and external carotid artery, we did not make use of intra-arterial shunt regardless of the back pressure of internal carotid artery. Operative complications were transient hypoglossal nerve palsy in four cases, cerebral hemorrhage occurred at previous cerebral infarction site in two cases, mild cerebral infarction in one case, hematoma due to anastomosis site bleeding in one case, and upper airway obstruction due to laryngeal edema probably caused by excessive retraction during operation in two cases. One patient expired due to cerebral hemorrhage occurring at previous cerebral infarction site. Conclusion: Carotid endarterectomy is a safe operative procedure showing low operative mortality. We suggest that intra-arterial shunt usage should be decided according to the ischemic change of electroercephalography regardless of the back pressure of internal carotid artery. Excessive retraction during operation should be avoided to prevent upper alway obstruction due to laryngeal edema and if upper airway obstruction is suspected, prompt management is essential.

• Journal of Fisheries and Marine Sciences Education
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• v.8 no.1
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• pp.92-107
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• 1996

Based on the act.ivity report for the coastal fisheries resources conducted from 1982 to 1989 by West, East Research Institute of Fisheries, some other reports from Korea Rural Economics Institute and etc., and the questionnaire results for the senses of fishermen, the fishing efficiency and conditions of by - catch of small fish in winged stow net were analized, and then some ways to prevent from by - catch of small fishes were suggested in this paper. The nationwide conditions of Permission and Disposal in winged stow net fishery arc that number of cases of coastal winged stow net fishery has dropped to 757 by 1994 while it was 961 in 1991 and that the number of cases of a sectional winged stow net fishery on the contrary has increased to 302 by 1994 while it was 11 in 1991. Regardless of region, catch per net by year in general has been on gradual increase in 1982 through 1989, but that showed decrease in 1994. From the view of region, the proportion of by - catch of shrimps and blenny is higher in Kyonggi, Chungnam with West Sea and that of anchovy and blenny is higher in Chonbuk, Chonnam, Kyongnam with South Sea. The average proportions of by - catch of small fish for 5 years from 1985 to 1989 are 86.9% for sand lance, 69% for anchovy, 63% for big eyed herring, 51% for blenny, 22% for Southern rough shrimp and 19% for akiami paste shrimp, hence sand lance and anchovy are highly by - catch effective while shrimps is not. Ways to prevent the over fishing of small fish in winged stow net fishery includes reduction of fishing frequency during April and August through November, the very season for small fish, use of meshes large enough for small fish to go through and assignment of fishing area to other than habitats of stationary fish.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.263-268
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• 2016

Metallothionein (MT) family of metal-binding proteins are involved in maintaining homeostasis and heavy metal poisoning. Recently, MT has been considered as a biomarker that can identify a particular species, very similar to the use of cytochrome oxidase I (COI) gene. Satsuma myomphala species of land snails have been reported from North-East Asia, including South Korea and Japan. In particular, the land snail species have been known from only a limited area of Geoje Island, Gyeongsangnam-do province of South Korea. Genetic studies of S. myomphala has been limited with only 6 nucleotide, 2 protein registered on the NCBI server. For elucidating the genetic information of S. myomphala, we conducted RNA sequencing analysis using Illumina HiSeq 2500 next-generation platform. We screened the MT gene from the RNA-Seq database to confirm the molecular phylogenetic relationship. After sequencing, the de novo analysis and clustering generated 103,774 unigenes. After annotation against PANM database using BLAST program, we obtained MT sequence of 74 amino acid residues containing the coding region of 222 bp. Based on this sequence, we found about 53 sequences using the BLAST program in NCBI nr database. Using ClustalX alignment, Maximum-Likehood Tree of MEGA program, we confirmed the molecular phylogenetic relationships that showed similarity with mollusks such as Helix pomatia and H. aspersa, Megathura crenulata.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.1-6
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• 2009

The effect of water temperature on fasting and post-prandial total ammonia excretion (TAN) of the starry flounder Platichthys stellatus (mean body weigh : $42.4{\pm}3.4g$) was studied. The fasting and post-prandial TAN excretions were measured under three different water temperatures (10, 15 and $20^{\circ}C$) for 24 hours using a recirculating system. In each treatment three replicates were set up and total 45 fish were used. Fish were taken to the indoor aquarium, acclimated over 10 days at three temperatures, and transferred to TAN measuring system for measurements of TAN excretion at the same temperatures. After 3 days of starvation, fasting TAN excretion was measured at each temperature. To investigate post-prandial TAN excretion, fish were hand-fed to satiation level with a commercial diet containing 50.2% crude protein for 7 days, two times daily 08 : 00 and 16 : 00 h. The fasting and postprandial TAN excretion increased with increased water temperature (p<0.05). Mean fasting TAN excretion rates at 10, 15 and $20^{\circ}C$ were 10.9, 11.2 and $12.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. The value at $20^{\circ}C$ was higher than those at 10 and $15^{\circ}C$ (p<0.05), but there was no significant difference between $10^{\circ}C$ and $15^{\circ}C$. Mean post-prandial TAN excretion rates at 10, 15 and $20^{\circ}C$ were 33.0, 43.4 and $55.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. Two peaks of post-prandial TAN excretions were observed, and the second peak was always greater than the first. The post-prandial TAN excretion rate reached to the maximum after 10 hours from the first feeding at $10^{\circ}C$($45.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), $15^{\circ}C$ ($64.5mg\;TAN\;kg\;fish^{-1}\;h^{-1}$) and $20^{\circ}C$ ($83.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), respectively. The TAN loss for ingested nitrogen at $20^{\circ}C$ (48.8%) was higher than that for $10^{\circ}C$ (43.0%) and $15^{\circ}C$ (45.7%). This study provides empirical data for estimating ammonia excretion and managing culture management of starry flounder under given temperatures.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.121-129
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• 2014

Marine algal flora and community structure were seasonally investigated at four sites in the vicinity of the Igidae on the southern east coast of Korea from May 2010 to February 2011. A total of 66 species including 9 of Chlorophyta, 14 of Phaeophyta, 43 of Rhodophyta were found during the survey period. Among these species, 16 species were found throughout the year. Seasonal mean biomass in wet weight was 123.6 (spring), 2,061.6 (summer), 412.0 (autumn), 678.9 (winter) $g{\cdot}m^{-2}$. Maximum biomass was recorded in summer($2,061.6g{\cdot}m^{-2}$), and minimum was recorded in spring($123.6g{\cdot}m^{-2}$). Spatial maximum and minimum species number were recorded at station 3 and 4(50 species) and at station 1(47 species). At station 1, 2 directly exposure on Yongho and Daeyeon cheon (stream) run off, and discharge from Nambu sewage treatment plants near coastal area, species diversity was relatively low and dominant species were similar throughout four seasons. The R/P, C/P and (R+C)/P value reflecting flora characteristics were 3.07, 0.64 and 3.71, respectively. The flora investigated could be classified into six functional groups such as coarsely branch form 39.39 %, sheet form 30.30 %, thick leather form 13.64 %, filamentous form 12.12 %, crustose form 3.03% and jointed calcareous form 1.52 % during survey period. The number of marine algae species in Igidea were 96 species at 1996 to 1997 and 66 species at 2010 to 2011, respectively. The change of seaweed species is due to the pollution loaded from sewage treatment plant and stream. We thus recommend that the positive maintenance control method like sewage treatment, for the protection of seaweed bed should be proceeded to near coastal area.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.35-48
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• 2021

In this study, the assessment of field applicability of in-situ remediation of nitrate-contaminated groundwater located in Yesan-gun was performed. Zero-valent iron/bio composite media injected PRB (Permeable Reactive Barrier) and monitoring well were installed in the contaminated groundwater site and monitored main remediation indicators during the PRB operation. Nitrate, nitrite, ammonia, Fe ion, TOC, and turbidity were analyzed and the diversity and population of microorganism in the PRB installed site were investigated for the verification of effect of injected PRB. In the study site where is an agricultural area, a river flows from west to east that forms a river boundary and the southern area has an impermeable sector. It was found that nitrate flows into the river, which is similar as groundwater flow. Simulation result for the fate of nitrate in groundwater showed steady state of nitrate arrived after 3~5 years passed. However, it is just to consider current conditions with no additional input of contaminant source, if additional input of contaminant source occurs contamination dispersion and time for steady state are expected to be increased. The monitoring results showed that Fe ion, TOC and turbidity in groundwater were not clearly changed in concentration after PRB installation, which indicates adaptability of the injected PRB for remediation of groundwater with no additional harmful effect to water quality. The concentration of nitrate maintained less than 5mg/L until 42 days after PRB installation and recovered its initial concentration after 84 days passed and showed termination of reactivity of injected zero-valent iron/bio composite media for removal nitrate. Nitrite and ammonia ions found after installation of PRB indicates reductive removal of nitrate. And the outstanding increase of microorganism diversity and population of Betaproteobacteria Class which includes denitrification microorganism explains biologically reductive removal of nitrate in injected PRB.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.528-534
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• 2009

Styan's Grasshopper Warblers (Locustella pleskei) are vulnerable species distributed in East-Asia only. Its known breeding sites in Korea are remote islets including Hongdo Islet, Chilbal Islet, Mara Islet, and Chuja Islets, and, therefore, the breeding biology of this species is still poorly known. This study was conducted on Mara Islet (N $33^{\circ}$ 06', E $126^{\circ}$ 16') from May to September 2008 to investigate the breeding status and breeding site characteristics of the grasshopper warblers. A total of 11 breeding pairs and their nests were found on trees and shrubs at artificially planted forests and hedges of Pinus thunbergii. The grasshopper warblers preferentially utilized the shrub trees for nesting places, and major nesting trees were Camellia japonica, Pittosporum tobira and Pinus thunbergii as nesting trees. Average heights of nesting trees and nests were $2.77{\pm}1.10m$ and $1.75{\pm}0.56m$, respectively. The grasshopper warblers selected lower shrubs and trees for nesting than randomly selected ones around them, probably to avoid strong and prevailed winds in flat and un vegetated environments on Mara Islet. The shape of nests was a round bowl-type, and measurements of nests were $11.9{\pm}0.5cm$ in exterior nest diameter, $11.1{\pm}1.1cm$ in height of exterior nest, $5.8{\pm}0.4cm$ in interior nest depth, and 6.0cm in interior nest diameter. It incubated eggs until the early August on Mara islet, and incubation periods of Mara Islet was possibly later than that of other areas. Furthermore, the clutch size in the study area was three, and they laid smaller number of eggs than normal clutch size (4~5 eggs) reported in other areas. Although we could not observe any nest predator on this species in the study area, selective cutting and pruning of trees will diminish dense shrub layer of forests. Therefore, it may affect the breeding of this threatened species which prefers dense shrubs of artificially planted forest of Pinus thunbergii. This study suggests that detailed and consistent further research on breeding biology and habitats of the grasshopper warblers are needed to conserve and manage of Pinus thunbergii forests on Mara Islet as an important breeding site of Styan's Grasshopper Warblers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.608-613
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• 1997

This study was designed to investigate the biochemical pollutant marker for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Pleuronichthys cornutus) in the Yellow Sea of Korea Protein contents in brain and muscle of wild flounders in the Yellow Sea were remarkably lower $(15\~45\%,\;and\;35\~45\%,\;respectively)$ than those of wild flounder in Pohang (control) of the East Sea. Lipid peroxide (LPO) levels in serum of wild flounders in the Yellow Sea were Significantly higher $(30\~70\%)$ than those of wild flounder in Pohang. Hydroxyl radical formations in serum of wild flounders in the Yellow Sea were significantly high $(15\~90\%)$ than those of wild flounders in Pohang. Superoxide dismutase (SOD) activities in serum of wild flounders in the yellow Sea were significantly lower $(20\~40\%)$ than those of wild flounders in Pohang, and glutathione peroxidase (GSHPx) activities in brain of wild flounders in the Yellow Sea were also significanlty lower $(10\~60\%)$ than those of wild flounders in Pohang. These results suggest that significantly decreases of protein contents in brain and muscle, remarkable in creases of malondialdehyde (LPD) in serum and decreases of SOD and GSHPx activities in serum and brain of wild flounders of the Yellow Sea may be used as a biochemical pollutant markers for diagnosis of marine pollutions.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.241-247
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• 2012

Purpose: This study was conducted to assess the association of metabolic syndrome and its components with glaucoma. Methods: We investigated the associations of metabolic syndrome and its components (abdominal obesity, impaired fasting glucose, high blood pressure, and dyslipidemia) with glaucoma using data from 19,162 adults aged 40 or above among the Korean National Health and Nutrition Examination Survey III (2005), IV (2007-9), V (2010). The logistic regression analysis was used for assessing those associations after adjusting demographic, lifestyle, and social economic status and for assessing the association of metabolic medication intakes with glaucoma risks. Results: After adjusting for age and sex, the risk of glaucoma was significantly higher in the subjects with impaired fasting glucose(Odds Ratio (95% confidence interval): 1.78 (1.25, 2.53)) and metabolic syndrome (1.45 (1.01, 2.08)) than subjects without those. These associations increased when additional adjusting for smoking, alcohol use, regular physical activity, income, education status(impaired fasting glucose: 1.89 (1.29, 2.77), metabolic syndrome: 1.52 (1.03, 2.25)). Glaucoma prevalence was borderline significantly increased according to the number of metabolic abnormalities(age and sex adjusted p for trend = 0.055). Use of antihypertensive medication was significantly associated with the risk of glaucoma. Conclusions: Metabolic syndrome and impaired fasting glucose were significantly associated with the increased glaucoma risk. Use of antihypertensive medication was also significantly associated with the increased glaucoma risk.