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        검색결과 11

        1.
        2018.12 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to determine the effects of vibration on primary (e.g. plasma cortisol), secondary (e.g. plasma glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), Na+, K+ and Cl- and tertiary (e.g. mortality) stress responses in cultured eel, Anguilla japonica. For this purpose, three groups (including one control group and two stress groups) were set up. The control group was made exposed to vibration corresponding to 48 decibel (dB, V) (produced using electric vibrators) for 15 minutes per hour every day, and the two stress groups was made exposed to vibration corresponding to 58 and 68 dB (V) (produced using the same electric vibrators), equally, for 15 minutes per hour every day. Blood was sampled at day 0 (before starting vibration stress tests, BS), and days 1, 3, 5, 7, 9 and 11 (after starting vibration stress tests). As a result, plasma cortisol showed trend to continuously rise by consecutive stress from 4.1±0.1 ng/ml in BS. In 48 dB group (control), cortisol showed the highest level with 7.6±0.9 ng/ml after 7 days (p <0.05), but at 9 and 11 days was not significantly compared with BS level. In 58 dB group, the cortisol showed the highest level with 43.1±4.8 ng/ml after 1st day. Cortisol of 68 dB group increased significantly during the experimental period (14.4±2.3~32.0± 5.7 ng/ml) (p<0.05). In 58, and 68 dB groups during the experimental period differed significantly compared to 48 group (p <0.05). Glucose in 48 dB were increased from 42.0 ±5.7 (BS) to 52.5±2.1 (1 day), the level was not significantly from 1 to 11 days. Glucose in 58 and 68 dB groups was increased significantly than BS during experimental period (p <0.05). K+ in 68 dB increased significantly (p <0.05) from 2.3±0.2 mE/ql (BS) to 3.3± 0.5 mE/ql at 5 days. In 48 and 58 dB groups during the experimental period differed significantly (p <0.05). Na+ and Cl- levels were not differed significantly during the experimental period. AST and ALT in 58 and 68 dB groups showed trend to continuously rise by consecutive stress. At 7 and 9 days in AST, between 48, 58 and 68 dB groups differed significantly (p <0.05). In 48, 58 and 68 dB groups at 1 day, blood hematocrit increased significantly higher than BS. The 11 days after vibration stress, the mortality in 48, 58 and 68 dB groups was 1.1, 5.1 and 5.8%, respectively. The present results have shown that A. japonica exhibited ''typical'' physiological responses when exposed to chronic vibration stress. These data suggested that chronic vibration stress caused substantial stress in the fish; especially the persisting elevated plasma AST and ALT levels observed would be expected to adverse effect. In conclusion, chronic vibration stress could greatly affects the hematological characteristics in A. japonica.
        4,000원
        2.
        2016.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Assuming that implicit and explicit knowledge are two different constructs, the current study takes unpaired English unaccusatives as its target grammar feature to investigate these two types of knowledge among Korean EFL learners. In line with the growing body of research utilizing a battery of tests, this study adopts a combination of validated tests to assess implicit and explicit knowledge. In doing so, this study lends support to previous studies, in that the L2 learners’ two types of knowledge are not on par. The findings indicate that proficiency was not correlated with the learners’ explicit knowledge, while it was highly correlated with their implicit knowledge. Moreover, regardless of the grammaticality of the unaccsuative sentences, the role of subject animacy varied depending on the learners’ different type of knowledge in relation to proficiency. Finally, a critical discussion on the importance of separating the two constructs of knowledge and implications for future research are provided.
        6,300원
        4.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To evaluate the biological response of sea squirt Halocynthia roretzi with different body size to heavy metals and its suitability for ecotoxicity assays, the effects of Cr, Cu and Zn on its clearance and oxygen consumption rates were investigated. Clearance and oxygen consumption rates of H. roretzi with various body sizes were calculated at different metal concentrations. Both clearance and oxygen consumption rate were negatively correlated with body sizes. Clearance rate of H. roretzi decreased gradually with increasing concentration of heavy metal, the decreasing rate was in an order of Cr¤Cu¤Zn. The oxygen consumption rate first increased at low metal concentration (below 100 μg L-1) and then decreased rapidly with increasing metal concentrations. The decreasing rate was in an order of Cu¤Cr=Zn. There was a trend that the clearance rate and oxygen consumption rate decreased drastically under a concentration of 400 μg L-1, and then decreased smoothly when the metal ion concentration increased continually. So the oxygen consumption and clearance rate at a concentration of 400 μg L-1 Cu could be thought as a suitable biological tool for exotoxicology analysis.
        4,000원
        6.
        2016.10 서비스 종료(열람 제한)
        Background : This text was conducted to compare the difference of fatty acid by part and ha bitat of Glehnia littoralis in Korea Midwest. Methods and Results : In Glehnia littoralis, Saturated fatty acid consisted of palmitic acid, ste aric acid, and unsaturated fatty acid was oleic acid, linoleic acid, linolenic acid. Content of w hole fatty acid was the most as 42.8% linoleic acid, and stearic acid was less best as 2.9%. Other fatty acid were oleic acid 27.1%, palmitic acid 15.3%, linolenic acid 11.9%. Fatty acid by plant part it was the most in leaf that linoleic acid (31.4%), and it was the most in root t hat linoleic acid (68.3%), and it was the most in breed that oleic acid (65.5%). Fatty acid by natural habitat contained in Incheon area located in high latitude more than Taean area. Conclusions : In Glehnia littoralis of Korea Midwest, The collection and cultivation of medici nal scope was broader, because difference of fatty acid content by natural habitat was light.
        7.
        2013.07 서비스 종료(열람 제한)
        NGS costs are decreasing rapidly, and beneficial application of the technology to plant genomics seems inevitable. Trying to interpret the agriculturally important traits like yield is actively in progress all across the globe. However, the current stage of bio-informatic technology as applied to the interpretation of agricultural trait appears not yet at a level of maturity to justify widespread plant genome sequencing for user-friendly molecular breeding. It is necessary to construct dense mutation block (DMB) based molecular breeding system for selecting plants with optimal agricultural performance; as well as for identifying useful quantitative trait loci (QTLs). Firstly, we screened and selected DMBs-specific INDEL markers obtained from SNV density profiles using 42 genome sequences of Korean cultivar and public sequences of 24 japonica rice cultivars. Secondly, we analyzed the genetic similarity between 288 Korean cultivars using 113 DMB-specific INDEL markers, which could differentiate on agarose gel by PCR. And we are going to integrate 360 INDEL markers up to 30 per each chromosome. Finally, we selected 40 founder lines considering the importance of the breeding, the purpose of use, and plant ecotype. To construct rice nested association mapping population we crossed each founder lines with the pollen of Hwayoungbyeo which was most commonly used in korean rice breeding program. F2 seed multiplication and generation iteration are ongoing.
        8.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        Regarding carotenoids content, the genetic basis, heritability and combining ability in six red pepper inbred lines were investigated using full diallel crosses. Both additive and non-additive gene actions govern inheritance of carotenoids content. The mean square of array through variance and covariance analysis (Wr-Vr) was insignificant, which suggest that inbred lines involved in diallel cross may have no epistatic effects. The Vr/Wr graph revealed the influence of partial dominant gene action towards low carotenoids content and the absence of non-allelic interaction. The H2 component was smaller than the H1 and the [H2/4H1] component was 0.187 less than 0.25, indicating unequal proportion of positive and negative alleles in the parents. The estimates of broad and narrow sense heritability for carotenoids content were 0.956 and 0.832, respectively. The variance of general combining ability (GCA) was relatively higher than that of specific combining ability (SCA), which implied that the additive gene effects were predominant as compared to both dominant and epistatic effects for the accumulation of carotenoids in this genetic population. The values of GCA of ‘62024L1’ and ‘62067L2’ were higher than those of the other parents. These 2 inbred lines, therefore, can be considered as useful breeding materials to enhance fruit carotenoids content in other red pepper varieties.
        9.
        2012.07 서비스 종료(열람 제한)
        Rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5㎎/ℓ L-cysteine, 1mM sodium thiosulfate, 1mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5㎎/ℓ silver nitrate). Co-cultivation temperature (23. 5℃ for 1 day, 26.5℃ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.
        10.
        2012.07 서비스 종료(열람 제한)
        Rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5㎎/ℓ L-cysteine, 1mM sodium thiosulfate, 1mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5㎎/ℓ silver nitrate). Co-cultivation temperature (23. 5℃ for 1 day, 26.5℃ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.
        11.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        The Korean native rice collection consists of landrace and weedy strains. The weedy strains are represented by two dis-tinctive populations, Share and red rice. The 242 representative accessions of Korean native rice collection were selected basedon the p