• Molecules and Cells
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• 제23권1호
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• pp.72-79
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• 2007

Demand for low-input sustainable crop cultivation is increasing to meet the need for environment-friendly agriculture. Consequently, developing genotypes with high nutrient use efficiency is one of the major objectives of crop breeding programs. This study was conducted to identify QTLs for traits associated with physiological nitrogen use efficiency (PNUE). A recombinant inbred population (DT-RILs) between Dasanbyeo (a tongil type rice, derived from an indica ${\times}$ japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) consisting of 166 $F_8$ lines was developed and used for mapping. A frame map of 1,409 cM containing 113 SSR and 103 STS markers with an average interval of 6.5 cM between adjacent marker loci was constructed using the DT-RILs. The RILs were cultivated in ordinary-N ($N-P_2O_5-K_2O=100-80-80kg/ha$) and low-N ($N-P_2O_5-K_2O=50-80-80kg/ha$) (100 kg/ha) conditions. PNUE was positively correlated with the harvest index and grain yield in both conditions. Twenty single QTLs (S-QTLs) and 58 pairs of epistatic loci (E-QTLs) were identified for the nitrogen concentration of grain, nitrogen concentration of straw, nitrogen content of shoot, harvest index, grain yield, straw yield and PNUE in both conditions. The phenotypic variance explained by these S-QTLs and E-QTLs ranged from 11.1 to 44.3% and from 16.0% to 63.6%, respectively. The total phenotypic variance explained by all the QTLs for each trait ranged from 35.8% to 71.3%, showing that the expression of PNUE and related characters depends signify- cantly upon genetic factors. Both S-QTLs and E-QTLs may be useful for marker-assisted selection (MAS) to develop higher PNUE genotypes.

• 한국작물학회지
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• 제37권3호
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• pp.288-298
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• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.79-81
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• 2001

A study was conducted to establish the degree of genetic divergence between different hybrid forms and rearing conditions through estimation of the minimum number of genes (allelic pairs) differentiating parents in terms of specific quantitative traits. It was established that the minimum gene numbers differentiating parental lines in the inheritance of cocoon was 1, of cocoon shell weight- between 1 and 2, and of silk filament length- between 2 and 3. The variability in the specific genetic parameter could be explained by the reliability of the statistical-and-genetic method used and the expression of genes affecting the formation of each of the characters tested. Gene expression, in its turns is conditioned both by the gene interaction within the genotypes and the different genotype response to environmental change. To go deep in the problem, experiments should be conducted under strictly controlled conditions, reducing the mathematical-and-genetic analysis to a physiological levels and hence to analyse the genetic nature of the specific quantitative character formation and its genetic control.

• 환경생물
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• 제22권4호
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• pp.532-536
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• 2004

Due to the fourth-instar larvae of C. riparius have a sensitive to ecdysteroidal molting hormones for the life cycle developments, accordingly the emerged adult affected corresponding to larval phase's environments. The emerged female from larval phase exposure to DEHP observed a fact body and clumsy fling behavior in females. The body volume of treated female groups was clearly larger than that of control fe- males. In the 2D/E gel 1108 protein spots were identified. The visualized protein spots allowed extraction of 27 protein spots differed more than 3 fold in DEHP treated animals, which was approximately 2.4％ of the total protein spots. In this view, the body volume (or morphological characters) was well observed and detected faster than physiological detection for various EDCs. In this study, the body volume as a detecting po-int for EDCs suggested a bio-marker in individual levels.

• 미생물학회지
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• 제1권1호
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• pp.30-37
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• 1963

Ten(10) strains of aerobic bacteria and two(2) strains of microaerobic bacteria were isolated out of soysauce which was brewed by the conventional process. The following bacteria were identified by studying their morphorogies and physiological characters. Bacillus pumillus-R-2; Bacillus subtilis var., aterimus-S-1; Bacillus licheriformis var-S-2; Bacillus subtilis-T-1; Sarcina maxima-T-2; Pediococcus acidi lactici-Z-2; Bacillus citreus var, . soyaB-Z-5. T-2 and Z-5 of the isolated bacteria were found good in growth even in the 24%-salted density, and Z-5 was more vigorous than T-2 though stinking. S-1 produced black-brown pigment from the medium containing various kinds of carbohydrate and the medium of soysauce which are available to S-1.

• 미생물학회지
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• 제25권2호
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• pp.137-143
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• 1987

Dominant genera of heterotrophic bacteria were investigated seasonally in Kum River estuarine sediments. Numerical taxonomy on the isolated heterotrophic bacteria were carried out according to their morphological, physiological, nutritional and biochemical characters. Heterotrophic bacteria in the depths of 0 to 10 cm of sampled sediments were almost facultative anaerobes, and 77.9% to 86.9% of them were Gram negative rods. Kominant genera among the isolates were Pseudomonas, Flavobacterium, Micrococcus, Cnterobacteria and Vibrio during sampling periods. According to their character analyses by similarity index(S), the isolates were clustered in fourteen groups at clay type sediments (Site 1) and four groups at sand type sediments (Site 2).

• 미생물학회지
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• 제11권2호
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• pp.63-68
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• 1973

Thirtythree strains of the Aspergillus spp. isolated from foodstuffs were observed through some physiological characteristics for detection of identification key of Aspergillus spp. 1) Each strain of Aspergillus spp. had their specific characteristics and could be used for identification of species. 2) Excellent amylase-producing fungi were observed among the isolated strains of Aspergillus spp. 3) Amylase activities increased for one week incubation period. 4) In the tests of common characters of aflatoxin-producing fungi among the 33 strains of Aspergillus spp., for example, conidial size, presence of sclerotia, kojic acid, and pigment production, coloration of phenol, reduction of methylene blue, etc.

• Toxicological Research
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• 제30권1호
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• pp.1-5
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• 2014

Xenograft models of human cancer play an important role in the screening and evaluation of candidates for new anticancer agents. The models, which are derived from human tumor cell lines and are classified according to the transplant site, such as ectopic xenograft and orthotopic xenograft, are still utilized to evaluate therapeutic efficacy and toxicity. The metastasis model is modified for the evaluation and prediction of cancer progression. Recently, animal models are made from patient-derived tumor tissue. The patient-derived tumor xenograft models with physiological characters similar to those of patients have been established for personalized medicine. In the discovery of anticancer drugs, standard animal models save time and money and provide evidence to support clinical trials. The current strategy for using xenograft models as an informative tool is introduced.

• 미생물과산업
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• 제26권1호
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• pp.8-17
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• 2000

Aspergillus을 이용하여 생리적 제 성질을 조사하였던 바 다음과 같은 결론을 얻었다. 1)각 균주들은 각각 그들의 특성을 가지고 있었으며 이로서 균동정의 가능성을 나타내었다. 2)Amylase측정결과에서 보면 비교적 역가가 높은 균주들이 관찰되었으며, 이는 일주간의 배양시간의 경과에 따라 역가가 증가하였으나 protease의 역가는 우수한 균주를 발견키가 어려웠다. Iodine의 착색대와 비착색대의 비율에 의한 역가의 정성적인 측정이 가능하였다.

• 동의생리병리학회지
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• 제25권2호
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• pp.334-338
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• 2011

Personality is an important factor in diagnosing Sasang constitutions, and has been studied by researchers with various statistical methods. Using these statistical methods, we obtain several clinical factors including significant p-value. In this paper, we applied a graph for analyzing personality questionnaires. The graph can well represent pairwise relations among items from the collected clinical information. In our analysis, we can find several meaningful personality patterns according to Sasang constitutions.