• Korean Journal of Plant Taxonomy
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• v.40 no.3
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• pp.157-162
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• 2010

Sequences of the trnL/F intergenic spacer of chloroplast DNA were used to investigate the intraspecific evoution and phylogeography of Sedum takesimense (Crassulaceae). The trnL/F intergeneric spacer sequences from 32 individuals of S. takesimense were either 291 bp (17 samples "without indel" in the following) or 297 bp (15samples "with indel 1") in length due to an indel of 6 bp. Two main cpDNA haplotypes were detected within S. takesimense. The haplotype with indel was found on Ulleung Island and without indel on Ulleung Island and Dok Island. This confirmed the existence of two cpDNA lineages with different geographical distributions. The cpDNA sequence analysis also suggested a putative long-distance dispersal event between Ulleung Island and Dok Island.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.400-401
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• 2001

새조개(Fulvia mutica)는 우리 나라, 동중국해, 홍콩 일본 등에 분포하며, 수심 10∼50m의 사니질에 서식한다. 패각이 얇고, 패각내면은 분홍색을 띄고 있으며, 육질부의 발은 길고 검은 색이며, 맛이 매우 좋아 식용 패류로서의 가치가 매우 높다. 본 종은 일본의 경우 성장(Tain and Makoto, 1997; 1998), 자원량 평가(Tain and Makoto, 1997), 어획량과 개체군 구조(Tain and Makoto, 1997) 등 여러 분야에서 많은 연구가 이루어지고 있다. (중략)

• 한국해양학회지
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• v.24 no.4
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• pp.172-183
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• 1989

Acoustical estimation of vertical distributions of zooplankton was carried out by using the backscattered signals of ADCP which was deployed in the Korea Strait in September, 1978. the backscattered signals of ADCP represents the total backward sound intensity caused by the scatters existing within the insonified water column of 8m deep. Based on these backscattered intensities, the estimated number of individual zooplankton (namely, Copepods) varies with depth such that in the surface layer above the thermocline, the numbers are exceedingly larger than the lower layer. It is also shown that a relatively larger number of individuals exists in the bottom cold water layer in the centeral part of the Strait. The horizontal distribution of the zooplankton in the surface layer across the west channel of the Strait shows that the number is higher in the coastal zone of the Korea and it decreases toward the central and then remains constant up to the vicinity of the Tsushima Island where it increases again. This type of distributions is well fitted to the one obtained at several stations by the conventional method at least in qualitative way. Therefore, it is quite plausible to use the ADCP data for monitoring the spatial and temporal distributions of zooplankton.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.127-136
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• 2020

This study was conducted to investigate the population characteristics of Nile tilapia (Oreochromis niloticus) in the Daegu Metropolitan City thermal effluent stream (Dalseo Stream) from January to November 2019. The collected fish were identified as 4,247 individuals of 20 species from a total of eight families. The dominant species was O. niloticus with 1,306 individuals and a high relative abundance (30.75%). The water temperature of Dalseo Stream was maintained above 10℃ throughout the year, which means that O. niloticus could inhabit it even in winter. The length-weight analysis showed a regression coefficient b of 3.1496, and a condition factor (k) of 0.0025 with a positive slope. Comparing the water temperature of Dalseo Stream and the total length of O. niloticus per investigation period, the 0-age individuals appeared May 29 when the water temperature was maintained above 22℃. In conclusion, the thermal effluent of Dalseo Stream allowed O. niloticus to survive in winter and maintain stable growth conditions and life cycles. The results of this study will inform ecological information on O. niloticus, which suggests that river management efforts should consider the management of O. niloticus populations for the conservation of fish species diversity.

• Korean Journal of Plant Taxonomy
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• v.43 no.1
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• pp.34-45
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• 2013

The Polygonum amphibium complex (Poygonaceae) is a highly polymorphic taxon that can grow in aquatic environments as well as in moist terrestrial habitats. Aquatic and terrestrial plants of the P. amphibium complex vary significantly in morphology and exhibit very complicated patterns of morphological variation, resulting in the description of numerous infra-specific taxa. Principal components analysis of 107 individuals of the P. amphibium complex from Asia and North America using 11 morphological characters showed that the aquatic plants can be discerned from the terrestrial plants by leaf size, shape, and petiole length. In contrast, both aquatic and terrestrial plants collected from the same population or locality shared identical sequences in the matK, psbA-trnH IGS, rbcL-accD IGS and trnL-trnF regions of the chloroplast DNA (cpDNA), suggesting that aquatic and terrestrial forms of the P. amphibium complex are not genetically diverged; morphological differences between the two forms are probably due to the differences in environmental conditions of the habitats. In addition, results from the morphological analysis and the maximum parsimony analysis of the cpDNA data set revealed that the plants from Asia including Korea, Japan, China, Mongolia and Russia Far East are diverged from those in North America and Europe, suggesting that the Asian populations should be recognized as a distinct variety, P. amphibium var. amurense Korsh.

• Journal of the Korean Data and Information Science Society
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• v.20 no.5
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• pp.787-796
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• 2009

A random coefficient model is applied when times of the repeated measurements are not fixed in experiments with respect to the subjects. The procedures of the inference of a random coefficient model are same as those of a mixed model. Diet experimental data was used for applying the random coefficient model. Various random coefficient models are investigated for the experimental data, and are compared each other. Finally, optimal random coefficient model would be selected. It resulted from the analysis that for the fixed effect factor, the baseline, treatment, height, and time effect were very significant. The treatment effect of the diet foods and exercises were more effective in losing weight than the effect of the diet foods only. The fixed cubic time effect was very significant. The variance components corresponding to the subject effect, linear time effect, quadratic time effect, and cubic time effect of the random coefficients are all positive. When quartic time effect was added as random coefficients the model did not converge. Thus random coefficients up to the cubic terms was considered as the optimal model.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.55-59
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• 2009

The mushroom takes in charge of decomposer in ecosystem and its production is important indicator for sounded ecosystem function. To determine standing crop of basidiocarps(fruit body of mushroom), a weight must be measured by harvesting mushroom individual in the field. But this method has profound affection on the basidiocarps population or its surrounding condition due to habitat destruction. Thus, in this study, without harvesting any mushroom in the field, we developed allometric equation using some morphological parameters to estimate standing crop biomass of basidiocarps. Lentinula edodes, Pleurotus ostreatus, Flammulina velutipes and Conocybe tenera were used for allometry. Morphological variables of the mushroom were pileus diameter, pileus area, stipe length and stipe thickness. Consequently, all the experimental mushrooms species showed significantly correlation in biomass estimation of basidiocarps from allometric equation (p<0.05). As a result of this research, the standing biomass of the basidiocarps could be indirectly estimated with proportional expression, allometric equation drived from morphological characters.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.161-171
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• 2023

The medium-large cladoceran species Simocephalus spp. predominantly occur in habitats with developed aquatic vegetation. Accordingly, due to Simocephalus' high contribution to zooplankton community biomass in the lake's littoral zone and wetland habitats, estimating their biomass is important to understand the matter cycling based on biological interactions within the aquatic food web. In this study, we reviewed the length-weight regression equations used previously to estimate Simocephalus biomass, directly measured S. serrulatus' body specification (length, width and area) and their biomass(dry weight) using instruments such as a microscopic digital camera and a microscale, and performed regression analysis between each other. When S. serrulatus biomass was estimated using the equation (Kawabata and Urabe, 1998) presented in 『Biomonitoring Survey and Assessment Manual』, Korea, errors between estimates and measures were relatively large compared to the S. serrulatus species-specific biomass estimate equation developed by Lemke and Benke (2003). In addition, both equations showed not only increasing trends in error (estimate-measure) with increasing S. serrulatus' body length, but also in error variance among similar-sized individuals. The results of regression analysis with dry weight by body specifications indicated that the most appropriate equation for estimating the biomass of S. serrulatus was derived from the width-dry weight exponential regression equation (R²=0.9555). The review and development study of such species-specific biomass estimation equations for zooplankton can be used as a tool to understand their role and function in aquatic ecosystem food webs.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.81-87
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• 2010

To estimate the genetic characteristics and cumulative power of discrimination (CPD) Korean Native Chicken. We used a total of 195 genomic DNAs from four breeds population (Korean Native Red chicken: R, Korean Native Yellow chicken: Y, Korean Native Black chicken: L, Ogal chicken: S). Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The lowest distance (0.05) was observed between the R and L strains and the highest distance (0.158) between the L and S strains. Korean native chicken strains (R, Y, K) have each other comparatively near genetic distance. Cumulative power of discriminate (CPD) was 99.999% by including the 10 microsatellites loci individual identification system. And then matching probability in that two different individuals incidentally have same genotype was estimated to $0.36{\times}10^{-7}$. The system employing the 10 markers therefore provided to be applicable to individual identification in Korea native chicken.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.140-145
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• 1994

B. falcatum plants were classified into six groups from group I to grop VI by the complete linkage cluster method depending on 8 charactenstics such as plant height. number of nodes, number of branches, position of the first branching node root diameter, root length, number of lateral root, dry weight of root. These groups are divided into two plants types, such as multi-branching and non multi-branching type by the number of branches, group II and group VI were the multi-branching types and the other groups were nonmulti-branching ones, Dry weight of root had highly positive correlation with the number of branches and negative correlation with the position of first branching nodes.