• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.694-706
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• 2012

The purpose of this study was to offer the raw data for conservation and restoration of aquatic ecosystem by surveying and analysing a water quality, sediment, benthic macroinvertebrate, fish and hydrophyte in Junam reservoir. In the result of analysing the water quality, pH was 8.2~8.4, 6.0~7.5mg/${\ell}$ in COD, 10.0~10.3mg/${\ell}$ in SS, 8.3~11.5mg/${\ell}$ in DO, 0.1mg/${\ell}$ in T-P and 1.2~1.3mg/${\ell}$ in T-N. In case of the sediments, Cd was 0.47~0.52mg/kg, 7.08~7.43mg/kg in Cu, 0.22~0.32mg/kg in As, 0.02~0.03mg/kg in Hg, 6.20~7.45mg/kg in Pb, 32.80~39.70mg/kg in Ni, 513.0~543.0mg/kg in F and 137.0~140.0mg/kg in Zn. $Cr^{6+}$ was not detected. The benthic macroinvertebrates were 432 individuals including 3 phyla, 5 classes, 9 orders, 26 families, 33 genera and 39 species, and the ecological score of benthic macroinvertebrate community(ESB) was 25. The fishes were 8 families and 14 species, and the invasive alien species were 2 taxa including Micropterus salmoids and Lepomis macrochirus. The hydrophytes were 63 taxa including 28 families, 42 genera, 56 species, 1 subspecies and 6 varieties. The emergent plants were 38 taxa(60.3%), 5 taxa(7.9%) in floating-leaved plants and each 10 taxa(15.9%) in free-floating plants and submerged plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.375-383
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• 2009

This study was carried out to develop transgenic rice cultivars with the CAX1 (accession no. U57411) gene. We successfully selected the transgenic rice plants over-expressing the Arabidopsis H+/$Ca^{2+}$ antiporter CAX1 (accession no. U57411) gene in T6 generation. The brown rice of the CAX1 expressing rice contained 13.4~68.0 % more calcium $(Ca^{2+})$ than that of the wild type and 5 lines were selected based on the phenotypes compared to the control cultivar at the GMO field. The CAX1 expressing transgenic rice plants were similar in phenotype to the wild type during the whole growth period. Also these selected 4 lines appeared to be resistant to blast, cold and water solution compared with the wild type. Difference in 1,000 grain weight of brown rice was observed among each line but grain shape did not show any morphological alternations. These results suggest the enhanced Ca-substrate specificity of CAX1 exchanger in donor plant. Therefore, intact CAX1 exchanger can be functionally useful for $Ca^{2+}$ nutrient enrichment of rice with reduced accumulation of undesirable cation.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.185-192
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• 2009

Fatty acid synthase (FASN) is a multi-functional enzyme with a central role in the synthesis of long-chain fatty acid and has been considered as a positional candidate gene for BTA 19 quantitative trait loci (QTL) affecting milk-fat content and fatty acid composition. In this study, we sequenced the FASN gene in several cattle breeds including Hanwoo and imported beef cattle, and identified novel DNA polymorphisms and their linkage relationship in Hanwoo. We found a significant frequency difference of the FASN (AF285607) g.17924 A$\rightarrow$G polymorphism between Hanwoo (70%) and other breeds and this polymorphism has been known for an association with fatty acid composition in Angus. Furthermore, by direct DNA sequencing in 18 unrelated Hanwoo, we identified 27 SNPs including nine novel variations in the FASN gene. Among 27 SNPs identified in the FASN gene, four SNPs were further genotyped in 100 Hanwoo and 96 imported beef cattle, and analyzed for haplotype construction and association with beef quality traits. We performed haplotype block and linkage disequilibrium studies using four selected SNPs. Two different haplotype blocks (block A: g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$ A; block B: g.13125 C$\rightarrow$T and g.17924 G$\rightarrow$A) were constructed and the block A in particular had a very high r2 (0.936), which indicated a nearly complete linkage disequilibrium existed between the g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$A polymorphisms. A total of four major haplotypes (frequency > 0.05) were identified with the four polymorphisms including TATG (0.36), CGCG (0.31), CGTA (0.19) and TACG (0.06). Statistical association analysis revealed that the g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$A polymorphisms in the FASN were significantly associated with meat color (P=0.004) and texture (P=0.0114). The g.13125 C$\rightarrow$T and g.17924 G$\rightarrow$A polymorphisms in the FASN were also significantly associated with back-fat thickness and quantity index (P=0.0179 and 0.0495, respectively). Our findings suggested that the FASN gene polymorphisms may be used for determining the (unsaturated) fatty acid contents and carcass trait in the Hanwoo beef.

• Korean Journal of Poultry Science
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• v.40 no.2
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• pp.115-120
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• 2013

Thyroid hormone (TH) plays a role in growth of the poultry. Thyroid-stimulating hormone (TSH) stimulates production and distribution of TH, and is a heterodimer which is formed by ${\alpha}$- and ${\beta}$-subunits. Most of TSH activity is known to rely on ${\beta}$-subunit. TSH-${\beta}$ gene is located on chicken chromosome 26 and associated with growth performances. Therefore, this study aimed to investigate the association of TSH- ${\beta}$ SNP (G1031C) with economic traits (layday, layw, layno, bw150, bw270, layw270) in Korean Native Black chicken, Rhode Island Red and Cornish. Allele frequency of GG genotype in Rhode Island Red (RIR) was found to be 1.00 in this study. A significant effect was only observed on body weight at day 150 in Cornish. In Cornish, body weights of chicken with the CC genotype ($302.15{\pm}6.336$) were significantly higher than that of the GG genotype ($294.56{\pm}4.537$) (p<0.05). These findings suggest that the G1031C SNP of TSH-${\beta}$ gene can be used for improvement of growth-related traits in Cornish.

• Biomedical Science Letters
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• v.2 no.1
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• pp.91-108
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• 1996

The present study was designed to examine effect of short term treadmill and weight-training on aging arophy in the rat skeletal muscle. Male rats of 24 months old were used. Each groups included control, treadmill and weight-training for 4 weeks by using treadmill apparatus and body press apparatus. The histo and cytochemical, ultrastructural and stereological changes in senile skeletal muscles of the rat were observed in the present study. During the training period the body weight and muscular weight in all groups remained constant. The volume density of muscle fiber type IIC and IIB were increased, that of type IIA was decreased, but type I remained constant in treadmill-training group. In weight-training rat, the density of type IIA and IIB were increased, both those of type IIC was decreased. But, all changes of muscle fiber type is not significant. Senile control group some usual formation of mild contraction band, liposuscin pigment and muscular splitting were observed. After treadmill-training, histological and ultrastructural changes occurred in the muscle fiber, such as irregularity of the sarcolemma, interfibrillar vacuolization, longitudinal splitting, and widened I-bond. After weight-training, the changes occurred in the trained muscle fiber, such as appearances of many lysosomes and autophagic vacuoles, severe contraction band, and breakup of myofibrils. Histo and cytochemical studies showed that the activities of succinic dehydrogenase and acid phosphatase remained constant, activities of $Mg^{++}$-ATPase decrease with training. Stereological changes were not observed in the volume and numerical density of all subject component, but the surface density of mitochondrial inner membrane was increased with treadmill-training. These experimental results suggested that endurance training during short-term may result in the adaptible response in senile skeletal muscles. On the other side, weight-training is bad for senile skeletal muscle.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.188-194
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• 2007

The relationships between pine mushroom emergence and meteorological factors were analyzed with three years (from 2003 to 2005) of measurement data at Yangyang site, in order to evaluate the effect of micrometeorological environment on pine mushroom production. fine mushroom was daily monitored and collected in the survey area during the its producing period (approximately one month). Pine mushroom production was highest in 2005 with the meteorological conditions of high temperature and frequent rainfalls in October. The production was lowest in 2004 due to dry conditions from mid September to late October, The meterological factors related to humidity (i.e., relative humidity, soil water content, and precipitation) were better correlated than those related to temperature (i.e., air and soil temperature, soil heat flux and solar radiation) with pine mushroom production. However, all of the correlation coefficients were statistically insignificant with values ranging from 0.15 to 0.46. Such poor correlations may be attributed to various other environmental conditions (e.g., topography, soil, vegetation, other fungi, the relationship between pine mushroom and pine forest) affecting pine mushroom production. We found that a mycelium requires a stimulation of low temperature (of three-day moving average) below $19.5^{\circ}C$, in order to farm a mushroom primordium which grows to pine mushroom after 16 days from the stimulation. We also found that the pine mushroom production ended when the soil temperature (of three-day moving average) fell below $14.0^{\circ}C$.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.654-663
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• 2019

Pollinators, which are important organisms in pollination ecology, have been highly valued for their economic contributions to crop production in the agricultural and biotechnology industries. As the production of over 70% of farm products, such as fruits, are mediated by pollinators, bees are important and useful insects to humans. However, pollinators are now seriously threatened with their numbers decreasing annually and their biodiversity being negatively affected by ongoing climate change, misuse of land, change of geographical features, and use of pesticides to increase agricultural production. Thus, surveys and analyses of the emergence and distribution of wild bees are important for conservation and management practices designed to help them continue to play their ecological and agricultural roles despite negative pressures, such as climate and topography changes. We surveyed pollinators, especially wild bees, at 51 research sites in South Korea every two to four weeks for two years from 2017 to 2018 using ez-Malaise traps and analyzed the temporal and spatial distribution of wild bees. The bees showed a normal temporal distribution that peaked between July and August. The bees' working period lasted until November. The spatial distribution of wild bees showed a significant correlation with latitude, and different bees were identified depending on the local habitat. No significant correlation was found for longitudinal distribution with regression analysis (p > 0.05), but this study identified locally specific wild bees. Although we could not predict significant distribution according to longitude, Further studies should be able to analyze the difference in the distribution of wild bees according to the climate, topography, and land-use patterns by humans. The results of this study provide basic information on pollinator distribution, which can be useful in agriculture and for the conservation and management of biodiversity in South Korean pollination ecology.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.334-344
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• 2020

A total of 24 families, 44 species, and 658 benthic macroinvertebrates were identified, and Ecdyonurus dracon Kluge (13%) was the dominant species in forested streams within the Yeonyeopsan (Mt.). A total of four habit categories (i.e., clingers (56%), burrowers (19%), swimmers (14%), and sprawlers (56%)) were identified, and clingers were the dominant habit at all survey points except point one (UP1). Habitat characteristics were depended on the hydraulic factors (e.g., flow velocity, depth, and substrates), water quality (e.g., DO and water temperature), and the habitat characteristics were differed in the riffle, which has a faster the flow velocity, compared by in the stagnant pool. In other words, in riffles, the clingers dominated in high flow velocity with the large maximum and median grain size for substrates in the habitats regardless of depth, but the burrowers and sprawlers were dominant in low flow velocity with the small maximum and median grain size for substrates in the habitats. Moreover, DO and flow velocity were in positive correlation (y = 0.6666x - 0.659, R² = 0.0851), and the habitat for burrowers was wider than that for sprawlers or clingers. The water depth was negatively correlated with water temperature (y = -26.397x + 283.87, R² = 0.1802) since the water temperature is more sensitive to insolation in shallow depth. pH was positively correlated with water temperature. The investigation of the habitat characteristics by separating the relations between pH and DO in upstream and downstream showed the low pH and high DO in the upstream with a high crown density of 68%, regardless of community composition. On the other hand, high pH and low DO in the downstream with a relatively low crown density of 51%. It was considered that the riparian forest played a role in suppressing the growth of attached algae and the controlling water temperature in headwater streams. Our findings identified the habitat characteristics of benthic macroinvertebrates in a headwater stream. We expected that the finding can provide reference data for suggesting conservation and management plans in a headwater stream and increasing academic value.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.153-165
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• 2001

We evaluated the health condition of Pyong-Chang river, the tributary of Han- River, using the Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) during September 1999${\sim}$August 2000. The annual mean of IBI,　which was estimated using eleven metrics, was 49 (range: $45{\sim}51$) and the mean of QHEI, which was estimated using seven parameters, was 88 (range: $76{\sim}94$) during　the study. The river health, based on the IBI criteria of Karr (1981), ranged from "excellent" to "good" conditions, while based on the habitat criteria of Plafkin et al. (1989), it ranged from "pristine" (comparable to reference) to "supporting" conditions. Values of IBI showed slight differences between upstream and downstream sites and QHEI values varied weakly depending on characteristics of variables. Regression analyses showed that annual values of QHEI had no functional relations with stream order (p = 1.82; n = 8) but showed some decreases near slight point-sources. This result indicates that conditions of physical habitat did not change highly with increases of the stream order. According to analyses of feed guilds, relative abundance of insectivores, omnivores and carnivores was 85.1%, 3.5% 0.3%, respectively. Also, relative abundance of sensitive and tolerant species was 75% and 4.6%, respectively, while exotic and morphological anomalies were not found in the river. These outcomes indicate that health condition of fish, based on the trophic conditions of U.S. EPA (1993), was excellent in the river. Regression analyses of IBI values against the QHEI showed that the variation of habitat conditions accounted 57% for the variation of the Index of Biological Integrity (p<0.05; $R^2\;=\;0.57$; n = 7).Overall data of IBI and QHEI suggest that the river health in the present is in optimal conditions but may be degradated by acceleration of chemical inputs and physical-habitat disturbance.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.215-225
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• 2013

To assess the efficacy of nematicides for the control of plant-parasitic nematodes in fruit and vegetables fields, soil samples were collected from a cucumber field at Gongju; from strawberry fields at Buyeo, Nonsan, and Jinju; and from a melon field at Gocksung in Jeonnam Province, Korea. Plant-parasitic nematodes were separated from each soil sample and identified. The susceptibilities of the nematodes to abamectin 1.68% SC, cadusafos 3% GR, dazomet 98% GR, fosthiazate 30% SL and BA12011 SL were examined under laboratory and field conditions. The average population density of plant-parasitic nematodes was generally reduced after the treatment with nematicides; however, there was increase in the population of Pratylenchus spp. in soil after treatment with fosthiazate at Buyeo and Gocksung. Furthermore, there were increased populations following treatment with abamectin, cadusafos, and dazomet at Gocksung. The control effects of BA12011 treatment on plant-parasitic nematodes were confirmed to be similar to those of the other 4 nematicides evaluated, although its control effect was higher than that of fosthiazate in cucumber-growing soil at Gongju. The effects of nematicide treatment on egg mass formation in each of the collected soils differed according to the region of soil origin. Abamectin was effective in reducing the degree of egg mass formation in Buyeo and Jinju soil, whereas BA12011 was effective in Nonsan and Gocksung soil. Dazomet was found to inhibit egg mass formation in Gongju soil. To evaluate the effect of the newly developed nematicide, BA12011, experiments were conducted in a cucumber-growing greenhouse. The average population densities of Meloidogyne spp., Pratylenchus spp., and Helicotylenchus spp. after the first treatment were reduced to a greater extent than after the second treatment. It is thus suggested that early nematicide treatment is important for effective control of plant-parasitic nematodes.