식물플랑크톤 생장이 소양호 수층의유기물 분포에 미치는 영향

조영근,이동훈,김상종 ( Young gun Jo,Dong Hun Lee,Sang Jong Kim ) 한국하천호수학회 1995 생태와 환경 Vol.28 No.2

In oder to estimate the influence of primary production on the distribution pattern of organic matter in Lake Soyang, general physico-chemical factors, primary productivity, concentration of POC and DOC, sedimentation rate of POC and the decomposition rate of phytoplankton biomass were measured from Feb. to Oct., 1993. From Feb. to Apr. the productivity by phytoplankton was low, but the resuspension of sediment materials brought high level of organic carbon into the watercolumns. Afterward primary production played major role in the supply of organic carbon. The productivity was highest in Sep. and summed upto 154. 1g-C·m^-2 during the term from May to Sep. From the value, 15.8g-C·m^-2 of exudate and the decomposition product(16.6∼33.2g-C ·m^-2) was added to the epilimnetic DOC pool, and 7.2g-C ·m^-2 of phytoplankton biomass to epilimnetic POC pool. But 86.3∼102.9g-C·m^-2 of it sinked into meta- and hypo-limnetic zone, and 11.6g-C·m^-2 settled down to sediment layer. Thus 79.5 g-C·m^-2 which corresponds to 52% of the amount of the produced, remained in the watercolumn.

수경시설 물놀이에 따른 대장균 감염의 위해도 분석

조영근,Zo, Young-Gun 한국환경보건학회 2012 한국환경보건학회지 Vol.38 No.1

Objectives: With the goal of quantifying the risk of children contracting gastroenteritis while playing at interactive waterscape facilities and evaluating the adequacy of current water quality regulations, risk assessment was performed with Escherichia coli as pathogen. Methods: Abundances of E. coli in the waters of interactive water features in South Korea were acquired from survey reports. A gamma distribution describing the volume of water swallowed by children during swimming activities was adopted. Exposure rate and risk were calculated by Monte Carlo simulation and dose-response models for various pathogenic E. coli. Results: E. coli was detected in 25 out of 40 facilities, with range of ~1,600 CFU/100 ml. The abundance fitted an exponential distribution. Simulated exposures ranged ${\sim}1.9{\times}10^{10}$ CFU, varying greater along E. coli abundance than the volume of water. Risk of children being infected by enterohemorrhagic E. coli was high, with range of ~0.85. When E. coli abundance was <200 CFU/100 ml, which is the current government threshold, the risk decreased to <0.43. Although the guideline successfully reduced the risk of adults being infected by a less virulent E. coli strains (<0.03), the risk for children could not be quantified due to lack of dose-response models for those pathogens for children. Conclusions: Under the current guideline, children are at risk of being infected if water is contaminated with by enterohemorrhagic E. coli. For other E. coli strains, the risk appears to be considerably less. The result warrants need for developing dose-response models for children for each pathogenic E. coli strain.

Effect of Stool Height on Slumped Posture During Push-and-Pull Weeding Motion

조영근,명성식,조승관,김한성 대한의용생체공학회 2015 Biomedical Engineering Letters (BMEL) Vol.5 No.2

Purpose The excessive accumulation of work burden is one of the main factors underlying musculoskeletal disorders in the farming population. The present study was carried out to determine the joint torques and muscle contractions of the lower body in relation to slumped postures with or without a stool during push-and-pull weeding motions. Methods Using data from a 3D motion analysis system, a 3D virtual human body model was created consisting of 19 segments and 59 muscles. Among these, the lower body joints (ankle, knee, hip, and lumbar) and muscles (tibialis anterior, gastrocnemius, biceps femoris, and erector spinae) were analyzed for four cases of slumped postures: without a stool and with stools of various heights (10, 15, and 20 cm). Results The flexion of the lumbar joint was presented during push-and-pull weeding motions without a stool. However, the extension of the lumbar joint was presented during pushand- pull weeding motions with a stool. The ranges of the joint torques did not change in a meaningful way between the results for the cases without a stool and with a stool. In addition, the results according to the stool height did not present meaningful outcomes associated with the angle change in the joints. Conclusions Irrespective of the height, a stool may provide support for slumped postures involving the lumbar joint and erector spinae.

Reductive Divergence of Enterobacterial Repetitive Intergenic Consensus Sequences among Gammaproteobacteria Genomes

조영근 한국미생물학회 2011 The journal of microbiology Vol.49 No.1

Enterobacterial repetitive intergenic consensus (ERIC) sequence is a transcription-modulating, nonautonomous,miniature inverted-repeat transposable element. Its origin and the mechanism of highly varying incidences,limited to Enterobacteriaceae and Vibrionaceae, have not been identified. In this study, distribution and divergence of ERICs along bacterial taxonomic units were analyzed. ERICs were found among five families of gammaproteobacteria, with the copy numbers varying with exponential increments. The variability was explained by genus (45%) and species (36%) affiliations, indicating that copy numbers are specific to subfamily taxa. ERICs were interspersed in genomes with considerable divergences. Locations of ERICs in a genome appeared to be strongly conserved in a strain, moderately in a species or a genus, and weakly in a family. ERICs in different species of a genus were from the identical population of sequences while ERICs in different genera of a family were nearly identical. However, ERICs in different families formed distinct monophylectic groups, implying vertical transmission of diverging population of sequences. In spite of large difference in copy numbers, overall intra-genome evolutionary distances among ERICs were similar among different species, except for a few genomes. The exceptions substantiated hypotheses of genetic drifts and horizontal gene transfers of mobility capacity. Therefore, the confined, variable distribution of ERIC could be explained as a two-step evolution: introduction and proliferation of ERIC in one of the progenitors of gammaproteobacteria, followed by vertical transmission under negative selection. Deterioration of sequences and reduction in copy number were concluded to be the predominant patterns in the evolution of ERIC loci.

환경수계 레지오넬라균 오염 지표의 메타분석

조영근,Zo, Young-Gun 한국미생물학회 2013 미생물학회지 Vol.49 No.4

레지오넬라균에 의한 자연환경의 수체 및 각종 시설 용수의 오염도를 조사하는데 적용할 수 있는 오염도 지표를 통상적으로 측정되는 수질항목 중에서 선정하려는 목적으로, 다양한 수체에 적용된 수질항목들이 레지오넬라균 오염도와 어느 정도 유의한 상관관계를 맺는 지에 관한 메타분석을 실시하였다. 환경부의 수질관리 지침에서 레지오넬라균 오염도의 위험지수로 사용되고 있는 대장균의 경우, 총대장균군 항목과 레지오넬라균 검출여부의 교차비(odds ratio; OR)로 분석하였는데, 교차비는 1.05(0.36-3.12, 95% CI)로, 오즈의 차이가 없을 확률이 0.92에 달하였다. 또한, 총대장균군 자료는 유의한 수준의 자료간 이질성을 보였으며(P=0.008), 무작위적인 자료간 이질성이 전체 교차비 변량의 63%를 차지하였다. 종속영양세균수(HPC)의 교차비가 2.72(2.04-3.63)로 1 보다 매우 유의하게 높았고(P<0.0001), 자료간 이질성이 없었다($Q_{df=8}$=12.7, P=0.12). 탁도와 염소농도, 철과 구리 이온의 농도 등이 레지오넬라균 검출여부와 함께 조사되는 통상적 수질항목이었으나, 자료수의 부족과 정량 자료의 통일성 부족으로 적절한 메타분석이 수행 될 수 없었다. 결론적으로, 분변균의 오염도 보다, 수중 레지오넬라균 서식지(아메바와 생물막)의 양을 표현하는 종속영양세균수가 레지오넬라균의 오염도 지표로 활용될 수 있을 것으로 사료되며, 실험 방법의 표준화와 경계값을 판단하는 후속 연구가 필요하다. To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

사전정보가 없는 도시환경 영상에서 강건하고 빠른 클러스터링 기반의 RANSAC

조영근,김아영 제어로봇시스템학회 2015 제어로봇시스템학회 국내학술대회 논문집 Vol.2015 No.5

ICRA 2017 SLAM 연구동향

조영근,정진용,김아영 한국로봇학회 2017 로봇과 인간 Vol.14 No.3

Characterization of Phylogenetic Incongruence among Protein Coding Genes of Vibrio Strains Pathogenic to Humans

조영근,Zo, Young-Gun The Microbiological Society of Korea 2013 미생물학회지 Vol.49 No.4

Vibrio cholerae균은 자연적으로 외부 유전자를 받아들이는 능력이 있으므로, 종간 수평적 유전자 전달 작용(LGT)을 받을 것으로 예상된다. 본 연구는 인체에 질병을 일으키는 3종의 비브리오균 사이에서 일어나는 LGT 현상의 정량적 측면들을 분석하였다. V. cholerae N16961, V. parahaemolyticus RIMD2210633, V. vulnificus CMCP6, Escherichia coli K12 substrain MG1655의 유전체 염기서열을 분석하여 4개의 유전체에 모두 존재하는 단백질 발현 유전자들의 4개 일조를 결정하였다. 각 조의 4개 유전자의 계통수를 작성하는 분석을 통하여, 다른 조들 간의 계통성의 일치성과 불일치성을 결정하고, 수직적 계통성과 수평적 계통성을 구분하였다. 약 70%의 조에서 계통수가 확정될 수 있었으며, 그 중 75%는 서로 일치하는 계통성을 보였고, 25%는 LGT 계통수를 보였다. 이 결과에 따르면, 비브리오균의 LGT는 다른 세균 분류균의 속보다는 과단위에서 발생하는 빈도의 LGT계통수를 보였다. 염색체별로 관찰하였을 때, 유전자 제공자별로 LGT가 집중되는 현상이 일부 관찰되었고, V. cholerae 균주의 작은 염색체에서는 염색체의 약 절반 길이에 해당하는 부분에서 제공자별 LGT 위치들이 집중되는 현상을 보였다. 이런 결과는 유전자 제공자에 따라 선택성이 반복적으로 작용하거나, 대규모의 LGT가 있다는 가설을 수립하게 하였으며, 유전자 제공자별로 LGT 유전형질이 선택성을 띄게 되는 원인과 그 현상이 비브리오균의 진화에 미치는 영향에 대한 연구의 필요성을 제시하였다. Lateral gene transfer (LGT) of genes from other bacteria into Vibrio cholerae is expectable because of the pronounced natural competence of the bacterium. In this study, quantitative aspects of LGT among the three species of Vibrio pathogenic to humans were characterized. Genome sequences of V. cholerae N16961, V. parahaemolyticus RIMD2210633, V. vulnificus CMCP6, and Escherichia coli K12 substrain MG1655 were analyzed to determine orthologous quartets of protein coding genes present in all four genomes. Phylogenetic analyses on the quartets were conducted to resolve vertical versus lateral patterns of gene polymorphisms based on congruence versus incongruence of phylogenetic trees. About 70% of the quartets could be resolved as either cohesive topology (75%) or LGT tree topologies (25%). The amount of LGT genes in Vibrio spp. appeared to be abnormally high for a genus and comparable to those of families. Patched distributions of LGT from different donors were observed on a chromosome. In the small chromosome of V. cholerae, physical linkages among LGT loci spanned half the length of the chromosome. Either accumulative selection for the donor alleles in LGT or presence of large-scale LGT events was hypothesized. These findings warrant further studies on the nature of donor-specificity of LGT alleles and its influence on evolution of Vibrio virulence to humans.

설비의 예지보전을 위한 고장진단 전문가 시스템

조영근,박용인,김상조 ( Y . K . Cho,Y . I . Park,S . J . Kim ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

대학 구내 시설물과 급식소 집기의 접촉에 의한 미생물학적 위해성의 정량비교

조영근,Zo, Young-Gun 한국미생물학회 2013 미생물학회지 Vol.49 No.1

대학 구내 학습시설과 집기들은 다중에 의해 이용되기 때문에 그 표면들은 감염성 병원체의 교차감염의 경로로 작용할 수 있다. 그러나 구내 집단급식소 등의 주요 위생관리 시설과 달리 정기적 위생관리의 대상이 아니며, 위생상태 현황이 잘 파악되지 않고 있다. 본 연구는 한 대학 단과대학 1,500여 명의 학생들이 강의실, 도서관 등 학습시설을 이용하면서 병원체에 노출될 수 있는 미생물학적 위해도를 구내급식소에서 집기 접촉을 통해 위해도와 정량적으로 비교하였다. 총대장균군을 병원성의 미생물의 대리모델로 간주하고, 학생들이 공통적으로 이용하는 대학구내 집기별로, 표면의 세균농도에 접촉률, 전이율 등을 적용한 노출알고리즘을 설정하여 결정론적 방법에 의한 노출량을 산정하였다. 급식소 집기의 세균에 대한 노출량은 약 1.0 CFU/day이었으며, 학습시설의 세균에 대한 노출량은 0.5 CFU/day로 급식소에서 노출량의 절반에 해당하였다. 그러나, 개인별 급식소 이용 정도가 달라, 약 70%의 학생들은 급식시설보다 학습시설의 인체접촉면에서 교차감염에 더 많이 노출되는 것으로 나타났다. 결론적으로, 승강기버턴을 비롯한 일부 학습 시설의 인체접촉면은 급식소와 마찬가지로 주기적 위생관리를 필요로 하는 것으로 판단되며, 학생들의 개인위생 관리 이외에, 계절적으로 변동하는 교차감염 가능 병원체의 종류에 부합하도록 인체접촉면 위생관리를 효율적으로 실시하는 것이 권고된다. As facilities and equipments for learning activities in college campuses are handled by mass public, their contact surfaces may function as major routes of cross-infection of microbial pathogens. However, unlike items in cafeteria which is the typical target for campus hygiene, those surfaces are not under regular surveillance or sanitary maintenance. In this study, I made a quantitative comparison of the risk of being exposed to microbial pathogens from use of learning facilities such as classrooms and library to the risk from use of cafeteria, for about 1,500 students in a college. Regarding total coliforms as surrogate model of bacterial pathogens, exposure rates were estimated for each item in learning facilities and cafeterias by devising deterministic exposure algorithms based on bacterial abundance, contract rates and transfer rates. The exposure rate in cafeterias was 1.0 CFU/day while learning facilities imposed the rate of 0.5 CFU/day, which reaches a half of the exposure rate in cafeterias. However, 70% of students were exposed more in learning facilities than cafeteria because individuals had different frequencies in using cafeteria. Based on the results, some human-contact surfaces of learning facilities, including elevator buttons, may require regular sanitary maintenance. An efficient sanitary maintenance considering seasonality in diversity of pathogens involved with cross-infections is suggested besides improvement of personal hygiene among students.