• 해양환경안전학회지
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• 제29권2호
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• pp.87-97
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• 2023

본 연구에서는 울진군 대형산불 발생이 연안해역에 미치는 영향을 파악하기 위하여 울진군 나곡(F-1), 후정(F-2), 봉평(F-3), 공세항(F-C)에서 수질과 함께 해조류의 종조성, 우점종 및 군집 특성을 분기별로 조사하였다. 수질 분석 결과, 산불에 대한 영향을 판단하기 위한 수소이온농도(pH)는 표·저층에서 각각 8.07~8.30과 8.12~8.48 이었다. 본 연구의 pH 값은 동해의 연안 해수에 있는 일반적인 농도 범위에 포함된 값으로 산불로 인한 직접적인 영향으로 볼 수 없었다. 연안 조하대에서 조사한 해조류의 분석 결과, 전 시기에 대한 해조류의 종조성 비율은 홍조류(58.1%) > 대롱편모조류(갈조류, 25.8%) > 녹조류(14.5%) > 현화식물(1.6%) 순이었다. 시기별 해조류의 우점종은 3월과 6월에 나곡(F-1)과 후정(F-2) 해역에서 대롱편모조류(Ochrophyta, 갈조류)의 미역(Undaria pinnatifida)이 가장 우점하였다. 9월과 11월은 봉평(F-3) 해역과 공세항(F-C)에서 각각 홍조류(Rhodophyta)인 우뭇가사리(Gelidium elegans)와 혹돌잎류(Lithophyllum sp.)가 가장 우점하였다. 군집분석에서는 그룹이 계절에 따른 특정 해조류의 출현 유무에 따라 2개(A, B)로 나누어졌다. 우점종은 그룹 A에서 미역, 우뭇가사리, 미끈뼈대그물말, 그룹 B는 주로 혹돌잎류가 출현하였다. 따라서, 연구지역의 해조류 종조성과 군집구조는 전형적인 수온에 따른 계절변화와 함께 대조구와의 유의미한 차이도 보이지 않아서 산불에 의한 영향은 나타나지 않았다.

• 한국환경생태학회지
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• 제31권6호
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• pp.520-528
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• 2017

외래생물인 아메리카동애등에는 뛰어난 유기물분해능으로 주목받아왔다. 이에 우리는 한국내 분포상과 유전적 다양성을 알아보기 위해 전국적으로 채집하여 미토콘드리아의 사이토크롬 C 산화효소 1 (CO1) 유전자를 이용해 집단유전학분석을 실시하였다. 그 결과 이 곤충은 한국에 성공적으로 정착한 것으로 보이며 10개의 미토콘드리아 유전자형이 있었고 개체군 간 분화가 뚜렷했다. 이 결과는 국내정착한 아메리카동애등에가 특정 유전자형의 모계만이 도입된 후 지역 간 분산이 제한적임을 나타내는 것으로, 이는 이들의 단거리 비행 경향에 기인한 것으로 추정된다.

• The Korean Journal of Ecology
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• 제24권6호
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• pp.385-394
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• 2001

An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.315-324
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• 2011

본 연구는 칡소와 한우 그리고 젖소의 각 군을 통하여 RAPD-PCR방법과 RFLP방법을 응용하여 칡소에서 특이적으로 발현되는 유전자의 검출과 발현빈도에 따른 표지유전자를 분석하여 칡소 특이적인 표지인자를 탐색하고자 실시하였다. 연구결과, RAPD분석을 통하여 칡소에서 특이적으로 표현되는 유전자들을 발견할 수 있었으며, 검출 유전자의 다양성이 모색과 종간의 차이가 있음을 알 수 있었다. 특이적으로 표현된 유전자들 중 칡소에서 특이적으로 표현되는 R9B 유전자를 발견할 수 있었고, 이 유전자는 한우와 젖소의 일부 DNA 염기서열상의 차이점이 있음을 확인할 수 있었으며, 추후 칡소의 표지유전자로 적용할 수 있을 것이라 사료되었다.

• Environmental Engineering Research
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• 제21권4호
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• pp.373-383
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• 2016

Cheonsu Bay, one of the most important in Korea as a coastal fishery is a semi-enclosed bay that is surrounded by large farmlands and industrial areas. This coastal environment has been affected by anthropogenic pollutants, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). The objectives of this study were to investigate the distribution of PCBs and OCPs in sediment, Manila clams, and mussels from Cheonsu Bay; the accumulation pattern of these chemicals in these bivalves in relation to seasonal changes; and the ecological risk from sediments and the risk to the Korean population from the consumption of these bivalves. The levels of ${\Sigma}PCBs$, ${\Sigma}DDT$, and ${\Sigma}HCHs$ were 69.3-109, 40.3-49.3 and 6.25-17.8 ng/g lipid in Manila clams, and 70.6-159, 38.6-102 and 9.00-13.5 ng/g lipid in Mussels. Significant seasonal variations in PCBs and OCPs concentrations were observed in the two bivalves, suggesting that the accumulation of PCBs and OCPs in these species is related to their spawning times. The dietary intake of these two bivalves and the resulting lifetime cancer risk (LCR) and non-cancer risk were calculated for the human population. The consumption of these bivalves seemed to be safe in relation to human health with negligible LCR and non-cancer risk.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.333-339
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• 2008

We investigated death rates, growth rates and recruitment of culms in two neighboring bamboo (Phyllostachys bamboosoides) stands nested in by two different bird species to analyze stand structure and to design conservation strategies. A third bamboo grove not used by birds, the Taewha stand, was included as a control stand. The bamboo stand occupied by birds in the family Ardeidae (the Ardeidae stand) had an approximately 1.5 times higher culm density than the stand occupied by birds in the family Corvidae (the Corvidae stand). The crude death rate and the number of newly emerged shoots were also higher in the Ardeidae stand than the Corvidae stand. The death rate for bamboo in the Ardeidae stand was not dependent on diameter at breast height (DBH) and was almost 40% for culms of all sizes, whereas most dead culms in the Corvidae stand were < 4 cm DBH. Consequently, we conclude that in the Ardeidae stand, density-independent causes of death are operating, while density-dependent factor are more important in the Corvidae site. The results of soil analysis in these stands suggest that the density-independent death pattern observed in the Ardeidae stand may be due to soil acidification resulting from wastes produced by the birds during breeding. On the other hand, the culm distribution and death patterns in the Corvidae stand suggest that the stand characteristics were not affected by the nesting birds. These results suggest that different conservation strategies must be applied to conserve bamboo groves used by ardeids and corvids for nesting.

• International Journal of Fluid Machinery and Systems
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• 제5권3호
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• pp.134-142
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• 2012

The competition to deliver ultra-low emitting vehicles at a reasonable cost is driving the automotive industry to invest significant manpower and test laboratory resources in the design optimization of increasingly complex exhaust after-treatment systems. Optimization can no longer be based on traditional approaches, which are intensive in hardware use and laboratory testing. The CFD is in high demand for the analysis and design in order to reduce developing cost and time consuming in experiments. This paper describes the development of a comprehensive practical model based on experiments for simulating the performance of automotive three-way catalytic converters, which are employed to reduce engine exhaust emissions. An experiment is conducted to measure species concentrations before and after catalytic converter for different loads on engine. The model simulates the emission system behavior by using an exhaust system heat conservation and catalyst chemical kinetic sub-model. CFD simulation is used to study the performance of automotive catalytic converter. The substrate is modeled as a porous media in FLUENT and the standard k-e model is used for turbulence. The flow pattern is changed from axial to radial by changing the substrate model inside the catalytic converter and the flow distribution and the conversion efficiency of CO, HC and NOx are achieved first, and the predictions are in good agreement with the experimental measurements. It is found that the conversion from axial to radial flow makes the catalytic converter more efficient. These studies help to understand better the performance of the catalytic converter in order to optimize the converter design.

• Asian-Australasian Journal of Animal Sciences
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• 제28권5호
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• pp.686-690
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• 2015

The adrenergic receptor beta 2 (ADRB2) plays a role in various physiological responses of the muscle to exercise, such as contraction and relaxation. Given its important role in muscle function, we investigated the structure of the horse ADRB2 gene and its expression pattern after exercise to determine if it can serve as a putative biomarker for recovery. Evolutionary analyses using synonymous and non-synonymous mutation ratios, were compared with other species (human, chimpanzee, mouse, rat, cow, pig, chicken, dog, and cat), and revealed the occurrence of positive selection in the horse ADRB2 gene. In addition, expression analyses by quantitative polymerase chain reaction exhibited ubiquitous distribution of horse ADRB2 in various tissues including lung, skeletal muscle, kidney, thyroid, appendix, colon, spinal cord and heart, with the highest expression observed in the lung. The expression of ADRB2 in skeletal muscle was significantly up-regulated about four folds 30 minutes post-exercise compared to pre-exercise. The expression level of ADRB2 in leukocytes, which could be collected with convenience compared with other tissues in horse, increased until 60 min after exercise but decreased afterward until 120 min, suggesting the ADRB2 expression levels in leukocytes could be a useful biomarker to check the early recovery status of horse after exercise. In conclusion, we identified horse ADRB2 gene and analyzed expression profiles in various tissues. Additionally, analysis of ADBR2 gene expression in leukocytes could be a useful biomarker useful for evaluation of early recovery status after exercise in racing horses.

• 한국발생생물학회지:발생과생식
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• 제17권1호
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• pp.45-53
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• 2013

The action of melatonin within the body of animals is known to be mediated by melatonin receptors. Three different types of melatonin receptors have been identified so far in fish. However, which of these are specifically involved in puberty onset is not known in fish. We cloned and analyzed the sequence of melatonin receptor 1a (mel 1a) gene in Nile tilapia Oreochromis niloticus. In addition, we examined the tissue distribution of gene expressions for three types of receptors, mel 1a, 1b and lc and investigated which of them is involved in the onset of puberty by comparing their expression with that of gonadotropin-releasing hormone receptor I (GnRHr I) gene using quantitative real-time PCR from 1 week post hatch (wph) to 24 wph. The mel 1a gene of Nile tilapia consisted of two exons and one bulky intron between them. Mel 1a gene was found to be highly conserved gene showing high homology with the corresponding genes from different teleost. All three types of melatonin receptor genes were expressed in the brain, eyes and ovary in common. Expression of mel 1a gene was the most abundant and ubiquitous among 3 receptors in the brain, liver, gill, ovary, muscle, eye, heart, intestine, spleen and kidney. Mel 1b and mel 1c genes were, however, expressed in fewer tissues at low level. During the development post hatch, expressions of both mel 1a and GnRHr I genes significantly increased at 13 wph which was close to the putative timing of puberty onset in this species. These results suggest that among three types of receptors mel 1a is most likely associated with the action of melatonin in the onset of puberty in Nile tilapia.

• 생태와환경
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• 제50권1호
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• pp.70-78
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• 2017

화산습지는 경북 군위와 영천 경계의 산정 분지 (표고 644~780 m)에 위치한다. Z.-M. 학파의 식물사회학적 방법으로 현장 식생조사가 이루어졌고, 현존식생도가 제작되었다. 단위식생의 출현종의 행동양식은 피도와 상대기여도를 이용하여 분석하였다. 버드나무하위군락, 전형하위군락, 산돌배하위군락으로 이루어진 오리나무-백당나무군락이 처음으로 기재되었다. 오리나무 우점림에 대한 선행 기재단위식생 (오리나무-진퍼리새군락, 오리나무-일본갈매나무군집, 버드나무-신나무군집 등)과의 군락분류학적, 군락동태학적 대응성이 논의되었다. 본 군락은 오리나무군강(Alnetea japonicae)에 귀속되고 산간 계류 선상지에서의 분지상(分地狀) 범람원 습생림으로 규정되었다. 화산습지의 잠재자연식생이고 증거 식생형으로서 식생보존등급 [I]의 자연식생으로 평가되었다. 입지의 수리수문 환경조건의 극적인 변화(건생화 및 부영양화)로부터 국가적 보호 전략이 요구되었다.