• Animal cells and systems
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• 제16권2호
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• pp.162-171
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• 2012

We investigated food webs of a $Salix$ $subfragilis$-dominated wetland in the Janghang wetland in the Hangang estuary, which is very close to the Demilitarized Zone, along the west coast of Korea. Our study focused on understanding sesarmine crab ($Sesarma$ $dehaani$)-related food webs in a $S.$ $subfragilis$ forest. For our study, we used carbon and nitrogen stable isotopes and fatty acid biomarkers. We collected samples of plants, animals, and detrital sediment from four quadrats ($5{\times}5m^2$) set in the $S.$ $subfragilis$ community. Samples were collected from September 2006 to June 2009, except during the winter hibernation period of $S.$ $dehaani$. In the wet season, the sediment showed relatively high ${\delta}^{13}C$ and low ${\delta}^{15}N$ signatures compared with relatively low ${\delta}13C$ and high ${\delta}15N$ signatures in the dry season. Mature $S.$ $dehaani$ appeared to feed on fresh leaves and other carbon sources, such as immature individuals or fish, in addition to detrital sediment, which appeared to be the main carbon source for immature crabs. Principal component analysis of fatty acid biomarkers of $S.$ $dehaani$ showed a clear difference between immature individuals (10-30 mm) and mature ones (larger than 30 mm), indicating that the main food source for immature crabs was detrital sediment, whereas mature crabs foraged plants in addition to consuming detrital sediment. On the basis of our results from stable isotope and fatty acid analyses, mature $S.$ $dehaani$ appeared to feed on detrital sediment and fresh leaves of $S.$ $subfragilis$ in summer in addition to engaging in cannibalism of immature individuals.

• 식물분류학회지
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• 제43권2호
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• pp.128-138
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• 2013

특산식물 금강초롱꽃의 국제단위 IUCN 적색목록의 평가를 시도하기 위해, GIS를 이용하여 분포도를 작성하고 분포면적과 점유면적을 계산하였다. 2011년과 2012년, 2년간 현장조사를 한 결과 성숙개체는 4개 지역에서 269개체(2011년), 3개 지역에서 216개체(2012)를 확인하였는데, 기존 알려진 20여개의 서식지를 고려한다면 전체 성숙개체는 1,000개체 이상으로 추정된다. 분포면적은 12,742 $km^2$, 점유면적은 76 $km^2$이고 추정되는 성숙개체 수에 근거한 평가 결과, 금강초롱꽃은 위기종(EN)으로 판정되었다. 국내 희귀식물의 보전지위 평가에 있어 IUCN 국제평가기준을 적용시키기 어려웠던 이유는 국내의 생물학적 정보 확보 노력의 부족과, IUCN 범주 및 기준의 낮은 이해도 때문인 것으로 판단한다. 개별 종의 정확한 보전지위 평가를 위해서는 개체군 생태학적 정보를 축적해야 하며, IUCN 평가 절차를 준수해야 한다.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.493-503
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• 2015

This study analyzed how spatial distribution of Himantormia lugubris is affected by the microenvironment in the Antarctic Specially Protected Area (ASPA) No. 171 located in the Barton Peninsula of King George Island that belongs to the maritime Antarctic. In order to determine the population structure of H. lugubris growing in Baekje Hill within ASPA No. 171, we counted the individuals of different size groups after dividing the population into 5 growth stages according to mean diameter as follows: ≤ 1 cm, 1-3 cm, 3-5 cm, 5-10 cm, and ≥ 10 cm. The count of H. lugubris individuals in each growth stage was converted into its percentage with respect to the entire population, which yielded the finding that stages 1 through 5 accounted for 32.8%, 25.3%, 15.9%, 22.5%, and 3.5%, respectively. This suggests that the population of H. lugubris in ASPA No. 171 has a stable reverse J-shaped population structure, with the younger individuals outnumbering mature ones. The mean density of H. lugubris was 17.6/0.25 m², mean canopy cover 13.3%, and the mean dry weight 37.8 g/0.25 m². It began to produce spore in the sizes over 3 cm, and most individuals measuring 5-10 cm were adults with sexually mature apothecia. The spatial distribution of H. lugubris was highly heterogeneous. The major factors influencing its distribution and performance were found to be the period covered by snow, wind direction, moisture, size of the substrate, and canopy cover of Usnea spp. Based on these factors, we constructed a prediction model for estimating the spatial distribution of H. lugubris. Conclusively, the major factors for the spatial distribution of H. lugubris were snow, wind, substrate and the competition with Usnea spp. These results are important for understanding of the distribution in the maritime Antarctic and evolution of H. lugubris that claims a unique life history and ecological niche.

• 한국어류학회지
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• 제22권3호
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• pp.162-167
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• 2010

대륙종개는(Orthrias nudus)의 생태적 특성을 연구하기 위해 2009년 1월부터 12월까지 어론천에서 조사하였다. 본 종은 하천 중 상류에서 상류역 여울에 걸쳐 분포하며 하상구조는 주로 큰 돌과 작은 돌로 이루어져 있었다. 서식지 수심은 15~46 cm 이었고 유속은 0.42~1.34 m/sec 상태를 유지하고 있었다. 성비는 1:0.98이었고 산란시기는 4~6월이며 산란기 수온은 $15{\sim}19.2^{\circ}C$이였다. 만 1년생 이상부터 성적 성숙이 이루어지기 시작하였다. 전장이 58~99mm의 집단은 만 1년생, 100 mm의 이상은 만 2년생으로 추정된다. 포란수는 평균 4,119개 이었고 먹이생물은 수서곤충인 하루살이목(Ephemeroptera), 날도래목(Trichoptera), 파리목(Diptera) 등이 있다.

• 미국학
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• 제43권1호
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• pp.83-97
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• 2020

"Behind a Mask" (1866) marks the new direction of Louisa May Alcott's artistic and personal life. Her European trip solidified her identity as a mature woman, most importantly as a mature American woman, one whose independence from Victorian stereotypes would, from now on, make her fortune and fame. Her sensational stories, especially "Behind a Mask," would tell truths that readers recognized but had rarely seen written. These truths would free them, and the author herself, to explore their talents as individuals. Henceforth, Alcott would embody the successful American artistic entrepreneur as one who shed the European domination of false titles and inherited wealth. These motifs of the transnational connection pervade the story, in the form of images and likenesses. Just as Alcott would soon, in two years, reach astonishing financial success with the publication of Little Women, her meteoric ascent parallels America's rise to power in the world's economy, which came about with almost alarming speed after the conclusion of the American Civil War.

• 한국수산과학회지
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• 제38권4호
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• pp.245-250
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• 2005

The maturity and spawning of Pacific cod, Gadus macrocephalus, was studied using samples caught by gillnets in the East Sea from January to December 2003. Monthly changes of maturity observed with the naked eyes for females showed that maturing Pacific cod appeared from August, and their numbers increased to $83\%\;and\;100\%$ in November and December, respectively. In January, mature and spawning Pacific cod were observed for the first time and composed over $40\%$ of the population. In February, the proportion of spawning individuals increased to over $50\%$, however, the mature individuals decreased to less than $10\%$. In March, mature fish were not found, and all were in an immature (spent) or spawning state. From April to July all fish remained in immature condition. The males maintained this trend with the females, whereas, mature males appeared from November to March. Monthly changes in the gonadosomatic index (GSI) of females and males showed higher values both in January and February and declined sharply in March. The lower value remained until October and then began to increase from November for the female population. For the males, however, this value remained lower until August, and then began to increase from September, and showed higher values in October through December than in January and February. These results indicated that the spawning season of Pacific cod was from December to March, and the main spawning season was from January to February, and the period of the spawning season was longer for males than the females. The diameter of the matured oocytes was 0.80-1.10 mm with a single mode of 0.95 mm. Fecundity was 1,300,000-9,400,000 in total length of 65-95 cm and the relationship between the total length (TL, cm) and fecundity (Fc) was Fc= $180,248\timesTL-10,883,638$. The total length at first maturity was observed at 57 cm for females and 47 cm for males. The size at $50\%$ group maturity was estimated to be 63.9 cm for females and 56.0 cm for males.

• The Korean Journal of Ecology
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• 제18권1호
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• pp.189-201
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• 1995

In order to clarify regeneration processes and mechanisms of the disturbed Pinus densiflora forest, responses of Pinus densiflora to gap formed by disturbance were analysed by growth of saplings and mature and growth equations were obtained from branch growth of mature trees and height growth of saplings, and age distribution of saplings and young trees recruited within gap was analysed in relation to gap age. Height growth of saplings within gaps was accelerated after gap formation. Such abrupt increases of growth of saplings after the gap formation might be resulted in the difference of growth of saplings between gap and non-gap areas. In fact, height and diameter of saplings in the central part of gap were larger than those of saplings in marginal parts of gap and non-gap area. However, density of saplings was not different in both parts. In addition, growth of annual rings of mature trees bordering on gap also increased after gap formation. Branch growth of mature trees bodering on gap was 6.3 - 6.5 cm /year and the mean radius of gaps created by death of only one canopy tree was about 3 m. Therefore, for those gaps to be closed by branch growth it will take 46 years. Growth of saplings within gap showed exponential equation. Fifty years will be required for the saplings to enter the forest canopy by the exponential growth equation. Therefore, gap created by only one tree might be closed by branch growth of surrounding canopy trees in advance of being done by height growth of saplings. But gaps created by death of trees more than 2 will be closed by the growth of saplings. Among the regenerating saplings and young trees within gaps, individuals established in advance of gap formation were more than those established after the gap formation. From these results, it was assumed that the disturbed Pinus densiflora forests in these sites were regenerated by height growth of saplings recruited in advance of gap formation.

• 한국수산과학회지
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• 제39권5호
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• pp.410-418
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• 2006

Sexual maturity and growth characteristics of Octopus minor were investigated in 796 individuals from mud flats in Goorori, Muan-Goon, Korea. Gonadosomatic index (GSI) peaked between June and July in females and between November and January in males. The discrepancy in the index peaks between females and males might result from the earlier sexual maturation of males. The sex ratio was biased toward females (68%) in April and toward males (78%) in September, although the differences were not significant (p>0.05). In females, about 50% of individuals with a mantle length of 70.6 mm were sexually mature versus 100% of individuals with mantle lengths over 80 mm. In females, fecundity was also related to size, ranging from 44 eggs in individuals with a mantle length of 54 mm to 179 eggs in the female with a mantle length of 100.5 mm. The relationship between mantle length (ML) an body weight (BW) was BW=0.008 ML$^{2.2797}$ (n=389, r$^2$=0.83, p<0.01) in males and BW=0.029 ML$^{2.2797}$ (n=407, r$^2$=0.74, p<0.01) in females. Analysis of co-variation showed that the difference in the slopes of the two regression lines was significant (p<0.01). Analysis of mantle length-frequency for each month revealed 1 to 3 normal distribution modes. The growth parameters obtained by fitting the modal progression to the seasonalized von Bertalanffy growth function (VBGF) were ML$\infty$= 112.38 mm, K=1.9, C=0.90, and WP=0.1. The results indicate that the seasonal growth oscillation of the stock is very strong and winter is the season when growth is the slowest.

• 한국어류학회지
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• 제30권2호
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• pp.84-91
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• 2018

본 논문은 소양호에 서식하는 내수면어업의 주요 수산자원 중 하나인 쏘가리(Siniperca scherzeri)의 성숙과 산란에 관하여 연구하였다. 본 논문에 사용된 쏘가리는 2014년 4월부터 11월까지 정치망과 자망을 통해 채집하였고, 암컷이 204개체로 전장범위는 113~365 mm이었고, 수컷은 197개체로 전장 범위가 140~342 mm이었다. 산란기가 시작되는 5월의 수온은 $15^{\circ}C$를 나타냈으며, 점진적으로 높아져 7월에 $26^{\circ}C$를 나타내었다. 암컷의 생식소 숙도지수(GSI)는 5월에서 7월까지 각각 2.3%, 4.6%, 3.1%로 나타났고, 수컷의 경우 8.0%, 6.6%, 4.5%로 나타났다. 난소 조직은 5월에 많은 수의 샘플이 중숙으로 관찰되었으며 6월에는 대다수가 성숙, 7월에는 완숙 및 방란으로 관찰되었다. 정소 조직의 경우에도 마찬가지로 5월에는 대다수가 중숙, 6월에는 성숙, 7월에는 방중으로 관찰되었다. 월별 성숙도와 생식소 숙도지수 (GSI), 생식소의 조직관찰을 통한 분석결과, 소양호에 서식하는 쏘가리의 산란기는 5월에서 6월로 추정되었다. 또한 군성숙도를 분석한 결과, 암컷 쏘가리의 50% 성숙체장은 245.16 mm로 나타났다.

• 한국수산과학회지
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• 제30권1호
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• pp.132-138
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• 1997

동해안 한해성 조개인 북방대합의 자원 증대를 위한 기초 자료를 얻기 위하여 1994년 3월부터 1995년 5월까지 주로 조직학적 방법에 의해 생식소의 발달과정과 생식주기를 조사하였다. 북방대합은 자웅이체로서, 생식소는 해부학적으로 소화맹낭과 족부 근육 사이에 위치하였다. 비만도는 1994년 6월에 0.19로 가장 높았으며 11월에 최소값을 보였다. 생물학적 최소형은 각장 50.0mm였으며, 80.0mm 이상의 대형개체에서도 $10\%$ 미만의 성적으로 미분화한 개체가 관찰되었다. 성숙한 난모세포의 크기는 $50\~60{\mu}m$였으며, 성숙기의 정소에서 정소란이 관찰되었다. 북방대합의 생식주기는 분열증식기 ($10\~1$월), 성장기 ($2\~4$월), 성숙기 ($4\~6$월), 산란기 ($6\~7$월) 및 휴지기 ($8\~9$월)의 연속적인 5단계로 구분되었다.