• Korean Journal of Heritage: History & Science
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• v.40
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• pp.387-411
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• 2007

The analysis of ancient DNA (aDNA) has become increasingly considerable anthropological, archaeological, biological and public interest. Although this approach is complicated by the natural damage and exogenous contamination of a DNA, archaeologists and biologists have attempted to understand issues such as human evolutionary history, migration and social organization, funeral custom and disease, and even evolutionary phylogeny of extinct animals. Polymerase chain reaction(PCR) is powerful technique that analyzes DNA sequences from a little extract of an ancient specimen. However, deamination and fragmentation are common molecular damages of aDNA and cause enzymatic inhibition in PCR for DNA amplification. Besides, the deamination of a cytosine residue yielded an uracil residue in the ancient template, and results in the misincorporation of an adenine residue in PCR. This promotes a consistent substitution (cytosine thymine, guanine adenine) to original nucleotide sequences. Contamination with exogenous DNA is a major problem in aDNA analysis, and causes oversight as erroneous conclusion. This report represents serious problems that DNA modification and contamination are the main issues in result validation of aDNA analysis. Now, we introduce several criterions suggested to authenticate reliance of aDNA analysis by many researchers in this field.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.53-59
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• 2010

The spatial variability in the food chain structure of an estuarine environment(Nanakita estuarine, Japan) was investigated using stable carbon and nitrogen isotope. Potential organic matter sources(TP:Terrstrial Plant, MPOM:Marine particulate organic matter, BMA:Benthic microalgae, EPOM:Estuarine particulate organic matter), sedimentary organic matter and benthic invertebrates(Nuttallia olivacea and Nereidae) were sampled at four locations with different tidal flat types(e.g. sanddy, sanddy-muddy and muddy). The main objective of the present study was to determine food sources of Nuttallia olivacea and Nereidae along with small-scale spatial variability within the community of benthic invertebrates. TP(${\delta}^{13}C=-26.6{\pm}0.76$ and ${\delta}^{15}N=2.7{\pm}0.31$) and EPOM(${\delta}^{13}C=-25.5{\pm}0.13$ and ${\delta}^{15}N=5.2{\pm}0.46$) were isotopically distinct from BMA(${\delta}^{13}C=-16.3$ and ${\delta}^{15}N=6.2$) and MPOM(${\delta}^{13}C=-19.6{\pm}0.08$ and ${\delta}^{15}N=8.9{\pm}1.70$). ${\delta}^{13}C$ values of sedimentary organic matter showed a distinct gradient in the range of -27.4 to -22.8‰ with a declining trend from the upstream to the downstream stations. The stable carbon and nitrogen isotope values of benthic invertebrates in the study site was -22.8 to -18.4‰ for ${\delta}^{16}C$ and 8.1 to 11.9‰ or ${\delta}^{15}N$, respectively. Mixing model(Isosource) calculations based on stable isotope measurements showed that benthic invertebrates of Nuttallia olivacea and Nereidae were found to be dominated by MPOM and BMA in stations. Whereas, TP and EPOM showed little influence to benthic invertebrates. The current result suggests that the different contribution for benthic invertebrates should be affected by both seasonal variation and physical factor among stations.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.1
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• pp.61-61
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• 2006

Objectives : This study was performed to understand the influence of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) genotypes on the spontaneously aborted embryos. Methods : DNA was extracted from tissue samples of 95 spontaneously aborted embryos and 100 samples of normal children randomly and 449 samples of normal adults were selected as the controls. MTHFR genotypes were determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Results : The aborted embryo group had higher frequency of MTHFR 677CC type (p=0.014) and lower 677CT type (p=0.063) than the controlled child group. The frequency of MTHFR 677CT type was drastically lower than that of controlled adult group (p=0.032). In the MTHFR C677T/A1298C combination, 677CC/1298AC genotype of the aborted embryo was significantly higher (p=0.034) than that of controlled child group, but it was not statistically significant in controlled adult group (p=0.063). Conclusion : MTHFR 677CC and MTHFR 677CC/1298AC genotypes may represent genetic markers for the risk of spontaneously aborted embryos at least in Koreans.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1161-1169
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• 2008

The removals of TCE and PCE vapor with or without a supply of toluene as a primary substrate were compared in a biofiltration process, and the variations of microbial communities associated with the removal were also investigated. As a result of investigations on the removals of TCE/PCE in a biofilter B within which TCE/PCE-acclimated sludge was attached on the surface of media without a supply of primary substrate, and those in another biofilter A where toluene-acclimated sludge was attached with a supply of toluene as a primary substrate, followings were found: (i) parts of microbes responsible to the decomposition of toluene vapor participate in the removal of chlorinated VOCs such as TCE and PCE, and (ii) effective biological removals of TCE and PCE vapor do not necessarily need cometabolism. Sequencing of 16S rDNA obtained from the band profile of DGGE (Denaturating Gradient Gel Electrophoresis), it was confirmed that: (i) uncultured alpha proteobacterium, uncultured Desulfitobacterium, uncultured Rhodobacteraceae bacterium, Cupriavidus necator, and Pseudomonas putida were found to be toluene-decomposing microbes, (ii) alpha proteobacterium HTCC396 is a TCE-removing microbe, (iii) Desulfitobacterium sp. is a PCE-decomposing microbe, and (iv) particularly, uncultured Desulfitobacterium sp. is probably a microbe decomposable not only toluene but also various chlorinated VOC vapor including TCE and PCE.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.235-240
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• 2002

Streptomycetes is a group of Gram-positive soil bacteria that growas a branching vegetative mycelium leading to the formation of spores, and display a physiological differenti-ation related to the synthesis of many secondary metabolites including antibiotics. Their complex life cycle and multicellular differentiation require various levels of regulation and types of signal transduction systems including eukaryotic-type serine/threonine protein kinases and prokaryotic-type histidine/aspartic acid protein kinases. Akt kinase that was found in cells is a sorine/threonine kinase controlling signal pathway for multi-tude of important cellular events. The activation or inactivation of Akt kinase in the cell is one of the critical regulatory points to deliver cell proliferation, differentiation, survival or apoptosis signal. To find the regula-tory protein homologous to Akt in Streptomyces, the fluorescien-labeled synthetic peptide (FITC-TRRSR-TESIT) was designed from the consensus sequence of target proteins for Akt kinase. From the difference of the mobility between the nonphosphorylated and phosphorylated synthetic peptides on Agarose gel electro-phoresis, the Akt-phosphorylating activity was monitored. The cell-free extract prepared from Streptomyces griseus IFO 13350 and the Akt homologous protein was purified by ammonium sulfate fractionation and many steps of column chromatographies such as, DEAE-Sepharose, Mono Q, Resource Phenyl-Soporose and Gel permeation column chromatographies. As a result, the protein phosphorylating the fluorescien-labeled Akt substrate was identified and it's molecular weight was estimated as 39 kDa on SDS-PAGE.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.108-108
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• 2002

고분자전해질들은 제지공정에서 건조지력제, 습윤지력제, 정착제, 보류제 등으로 널리 사 용되어지고 있으며, 이러한 고분자전해질들이 보유하고 있는 관능기의 종류와 분자량에 따라 각각의 다른 특성을 발현하게 된다. 이중 관능기의 종류와 비율에 따라 결정되는 중요한 특성 중 한가지가 전하밀도이며, 이러한 전하밀도는 제지공정에 사용할 때 습부공정에서 매우 중요 한 인자라 할 수 있다. 전하밀도는 고분자전해질의 분자구조와 단량체의 종류에 따라 다르며, 적용 pH의 조건에 따라 변화하게 된다. 3급 아민과 4급 암모늄을 관능기로 가진 고분자전해질 의 경우 pH에 따른 전하밀도의 변화는 이미 잘 알려져 있는 바,3급 아민을 작용기로 가진 양이 온성 고분자전해질은 pH 9에 도달하면 양전하를 완전히 상실하고,4급 암모늄을 작용기로 가진 양이온성 고분자전해질은 pH의 변화에 상관없이 양전하가 변하지 않는다고 보고되어 있다. 본 연구에서는 양이온성과, 양쪽이온성 고분자전해질들 중 Cationic PAM, Amphoteric P PAM, PolyDADMAC, Epoxide polyamide resin, Epi-DMA copolymer 등을 시 료로 사용하였 으며, 양이온성 관능기의 종류가 다른 고분자 전해질을 이용하여 pH 변화에 따른 전하밀도의 변화를 검토하였다. 또한 일반적으로 중성 초지공정의 pH 조건은 7.0 - 8.0이며, 이 pH 조건에 서 고분자전해질의 거동은 매우 중요하다고 할 수 있다. 따라서 양이온 관능기의 종류에 따른 고분자전해질들을 pH 7.8에서 보관시간에 따른 전하밀도의 변화를 조사하였으며, 전하밀도가 변화하는 양상에 따라 양이온성 관능기의 분자구조의 변화를 검토하였다. p pH 변화에 따른 전하밀도의 변화 결과로부터 3급 아민을 포함한 양이온성 고분자전해질 뿐만 아니라,4급 암모늄을 포함한 일부의 양이온성 고분자전해질 또한 알카리 조건에서 전하 밀도가 감소하며, 강한 얄차리 조건에서는 음이온성 고분자전해질로 변화하는 현상을 관찰할 수 있었다. 이상의 결과들로부터 약 알카리(pH 7.5 - 8.0) 조건 하에서도 시간의 변화에 따라 4 급 암모늄을 포함하는 고분자전해질의 전하밀도가 변화할 것이라 예측하였으며, 실험을 통해 그 사실을 확인하였다. 알카리 조건에서 전하밀도가 변하지 않는 4급 암모늄 고분자전해질과, 전하밀도가 변하는 4급 암모늄 고분자전해질의 분자구조를 비교해 볼 때, 그 원인은 4급 암모늄 의 관능기가 고분자 연쇄로부터 가수분해 되어 나타나는 현상으로 판단된다.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.299-309
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• 2014

HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.222-233
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• 2010

This paper aims at predicting the BDI from Jan. to Dec. 2010 using such econometric techniues of the univariate time series as stochastic ARIMA-type models and Hodrick-Prescott filtering technique. The multivariate cause-effect econometric model is not employed for not assuring a higher degree of forecasting accuracy than the univariate variable model. Such a cause-effect econometric model also fails in adjusting itself for the post-sample. This article introduces the two ARIMA models and five Intervention-ARIMA models. The monthly data cover the period January 2000 through December 2009. The out-of-sample forecasting performance is compared between the ARIMA-type models and the random walk model. Forecasting performance is measured by three summary statistics: root mean squared error (RMSE), mean absolute error (MAE) and mean error (ME). The RMSE and MAE indicate that the ARIMA-type models outperform the random walk model And the mean errors for all models are small in magnitude relative to the MAE's, indicating that all models don't have a tendency of overpredicting or underpredicting systematically in forecasting. The pessimistic ex-ante forecasts are expected to be 2,820 at the end of 2010 compared with the optimistic forecasts of 4,230.

• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.285-291
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• 2008

Background: We conducted a case-control study to evaluate the potential association between SERPINA1 genotypes ($M1_{Val}$, $M1_{Ala}$, S, and Z) and the risk COPD. Methods: The study population consisted of 93 patients with COPD and 112 healthy controls. The polymerase chain reaction and restriction fragment length polymorphism for detecting the SERPINA1 variants. Results: The M2 allele of the SERPINA1 gene was significantly associated with the risk of COPD in Koreans. The effect of the M2 allele on the risk of COPD was more pronounced in the subgroup<64 years. Conclusion: These results suggest that SERPINA1 polymorphisms may contribute to a genetic predisposition for COPD. However, additional studies with larger sample sizes are required to confirm our findings.

• Journal of Life Science
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• v.27 no.9
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• pp.1003-1010
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• 2017

An open reading frame coding for mannanase predicted from the partial genomic sequence of Paenibacillus woosongensis was cloned into Escherichia coli by polymerase chain reaction amplification, and completely sequenced. This mannanase gene, designated man26AT, consisted of 3,162 nucleotides encoding a polypeptide of 1,053 amino acid residues. Based on the deduced amino acid sequence, Man26AT was identified as a modular enzyme, which included a catalytic domain belonging to the glycosyl hydrolase family 26 and two carbohydrate-binding modules, CBM27 and CBM11. The amino acid sequence of Man26AT was homologous to that of several putative mannanases, with identity of 81% for P. ihumii and identity of less than 57% for other strains of Paenibacillus. A cell-free extract of recombinant E. coli carrying the man26AT gene showed maximal mannanase activity at $55^{\circ}C$ and pH 5.5. The enzyme retained above 80% of maximal activity after preincubation for 1 h at $50^{\circ}C$. Man26AT was comparably active on locust bean gum (LBG), galactomanan, and kojac glucomannan, whereas it did not exhibit activity on carboxymethylcellulose, xylan, or para-nitrophenyl-${\beta}$-mannopyranoside. The common end products liberated from mannooligosaccharides, including mannotriose, mannotetraose, mannopentaose, and mannohexaose, or LBG by Man26AT were mannose, mannobiose, and mannotriose. Mannooligosacchrides larger than mannotriose were found in enzymatic hydrolyzates of LBG and guar gum, respectively. However, Man26AT was unable to hydrolyze mannobiose. Man26AT was intracellularly degraded into at least three active proteins with different molecular masses by zymogram.