• The Korean Journal of Ecology
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• v.12 no.3
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• pp.133-144
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• 1989

The morphology and flowering time of two Suaeda japonica populations from different habitats, the creek and the bank of the mudflat in Sorae, were surveyed. And standard transplantation and reciprocal transplantation were carried out to determine whether their characteristics were genetically fixed or not. Also soil sample of these habitats were analyzed. The amounts of loss on ignition, maximum field capacity, total nitrogen, exchangeable calcium and potassium, and soluble phosphorus were found to be significantly different between two habitats. Leaf thickness, leaf width, leaf length, stem height number of branches, and number of seeds were significantly different between plants of two populations. And flowering times of two populations did not overlap. According to the results of transplantation, leaf width, leaf thickness, and flowering times were the same as those at their original habitat. But the stem lenght, leaf lenght, number of branches and unmber of seeds were not. Therefore, the differences in the leaf length, leaf thickness, and flowering time seemed to bo genetically fixed. It were suggested that the creek bank populations of Suaeda japoinica were to be considered as different ecotypes.

• The Korean Journal of Ecology
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• v.15 no.4
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• pp.377-386
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• 1992

Seasonal changes of symbiotic nitrogen-fixation activity and growth characteristics of four different natural populations of kummerowia striata were quantitatively analyzed during the growing period. the nitrogen-fixation activity of root nodules attained the maximum rates of 148, 132, 102 and 100$\muM\;C_2H_4\;\cdot\;g\;fw\;nodule^{-1}\;\cdot\;hr^{-1}$, respectively for sunny, multibranched, shade and unibranched populations at the optimum growth conditions. and the seasonal changes showed fluctuations by environmental conditions such as light, temperature, nutrient contents, water stress and plant ages, etc. The multibranched plant showed the greater amount of leaf and root nodule biomass, and the higher nitrogenase activity than the unibranched plant. the optimum conditions of leaf chloropht11 and water content of each organ indicated the active growth and the maximum fresh biomass of 4 different populations were 1.92, 1.85, 0.97 and 0.56 g $fw\cdotplant^{-1}$ for shade multibranched, sunny and unibranched populations, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2325-2327
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• 2016

Gall bladder cancer is generally fatal. The high morbidity and mortality due to gall bladder cancer exerts a significant impact on efforts towards cancer control in high risk populations of the World and a rationale program for control of gall bladder cancer mortality has remained as an unmet need in these populations. Currently there are no effective strategies for controlling gall bladder cancer mortality. This mini review is to highlight the need and feasibility for secondary prevention of gall bladder cancer by screening in high risk populations. A way forward is to assess the role of secondary prevention of gall bladder cancers by conducting randomized-controlled screening trials in high risk populations.

• Plant Resources
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• v.5 no.1
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• pp.86-94
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• 2002

This study characterized the genetic variations of 13 populations of Asplenium antiquum and its relative species using randomly amplified polymorphic DNA (RAPD) markers. A total 88 scorable RAPD bands were generated by the 12 random oligo primers and were analyzed by Nei and Li's genetic distance. High genetic variability was detected between A. antiquum and A. nidus, with the range from 0.568 to 0.682. And slightly low genetic variations showed within the populations of same species. Seven populations of A. antiquum showed slight differences (0.000-0.216), and five populations of A. nidus showed similar low genetic variations (0.114 to 0.171). Two individuals from Sup-seom Island which are growing in might be the regenerated one from abroad. A. antiquum were clustered as two groups (Group I, Group II) by UPGMA phenogram. And five populations of A. nidus were clustered as two groups correlated with geographical distribution. The RAPD data was very useful to define the genetic variations and to discuss the phylogenetic relationships among A. antiquum and the related species..

• The Korean Journal of Zoology
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• v.30 no.3
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• pp.211-221
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• 1987

Starch gel electrophoresis was used to estimate the degree of genic variation and genetic relatedness among twelve populations of the Cat-Sanke(Elaphe diene) in Korea. Out of the 17 loci examined 9 loci (Mdh-2, Ldh-1, Ldh-2, Idh-1, Idh-2, Adh, Aco-3, ep, Got-1) were monomorphic with identical mobility in all populations, 4 loci (Pgm, Mpi, Pept-1, Got-2) were nearly identical with minor allele frequency differences, and 4 loci (Mdh-1, Fgi, Est-2, 6psd) showed moderate variation. Levels of genic variation were similar to those found for other reptilian species. The mean genetic similarity value(S) among twelve populations is 0.966. Chechu population was slightly remote genetically from the mainland populations.

• Animal cells and systems
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• v.1 no.4
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• pp.535-538
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• 1997

Allozyme variation of seven enzyme systems was analyzed from 202 individuals from four Korean populations of Atractomorpha lata. These populations exhibit higher levels of values of in most other insects with a mean 64% of polymorphic loci and a mean 0.384 of expected heterozygosity within populations. Fixation indices indicated considerable substructuring within populations sampled (mean $F_{is}=0.403)$, indicating probable inbreeding or assortative mating coupled with restricted migration between subpopulations. This was supported by the field observation that the species exists as small, discrete colonies in meadow habitats and females carry males. In addition, significant differences in allere frequencies between males and females at polymorphic loci examined (70%, 16 of 23 cases) could account for the observed heterozygote deficiencies.

• Development and Reproduction
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• v.21 no.4
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• pp.435-440
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• 2017

The author performed PCR-based genetic platform to measure the hierarchical dendrogram of Euclidean genetic distances of Korean scallop populations (KSP), particularly for Chlamys farreri, which was further compared with those of the Chinese scallop populations (CSP), by employing the with specifically designed oligonucleotide primer sets. The scallop is economically and ecologically very important bivalves in South Korea. Relatively, individuals of KSP population were fairly distantly related to that of CSP population, as shown in the hierarchical dendrogram of Euclidean genetic distances. Comparatively, individuals of KSP population were fairly distantly related to that of CSP population. Thus analysis of genetic difference between scallop populations could provide important statistics for fishery and aquaculture. Overall the results showed specific and/or conserved genetic loci between scallop populations. Information on the genetic distance of the bivalve would be helpful to understand scallop expansion or conservation in the coastal regions of South Korea. Specific markers developed by the author will be useful for the analysis of scallop population genetics and distribution in coastal region.

• Korean Journal of Microbiology
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• v.22 no.4
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• pp.243-247
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• 1984

The effect of the heavy metals copper and cadmium on the natural populations of surface microlayer and subsurface water was investigated. Two microbiological parameters, number of colony-forming bacteria and $^{14}C-glucose$ uptake rate, were evalated. The two natural bacterial populations showed different tolerances of the heavy metals. The ingibition of bacterial growth and activity occurred more strongly in the 1m-depth samples than in neuston populations. The results support the existence of autochthonous bacterioneuston populations in marine environment.

• Journal of Plant Biology
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• v.20 no.3
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• pp.119-126
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• 1977

The maximum relative growth rate of algae treated with Zinc was shown as follows: 15, 8, 6, 3 and -5% per day for the rather sensitive Chlorella sp. populations, or 14, 7, 5 and 4% per day for the Pleurococcus sp. populations, and 22, 20, 13, 9 and 7% per day for the more resistant Scenedesmus spinosus populations, respectively for the culture medium with 0, 1, 5, 10 and 20 ppm of Zinc treatment. With mixed cultures of Chlorella sp. and Scenedesmus spinosus populations, the growth of the Chlorella sp. population overcame that of the S. spinomsus population from the cultures treated with relatively low concentration of Zinc. On the contrary, the population growth of the latter resistant species overcame that of the former sensitive species when the concentration of Zinc was above 5 ppm Zn of the medium. This paper describes the results of further investigations of the effects evaluated by direct cell counts method, optical density comparisons, oxygen production and consumption determinations and the measurements of the fate of Zinc treated in the solutions.

• Development and Reproduction
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• v.25 no.2
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• pp.105-111
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• 2021

A PCR-founded genetic analysis aim and principle was used to foster a hierarchical polar dendrogram of the Euclidean genetic distances (GDs) for two arkshell populations, Scapharca broughtonii (YEOSU, Yeosu population and JINHAE, Jinhae population). Five oligonucleotides primers were make use of to craft 354 and 390 scorable bands in the Yeosu and Jinhae populations, respectively, outspreading in DNA fragment size from 100 bp to 1,600 bp. The bandsharing (BS) results disclosed that the Jinhae population had a higher average BS value (0.700) than that for the Yeosu population (0.692). The GD between individuals supported an adjacent association in grouping II (JINHAE 12 - JINHAE 22). The observation of a noteworthy GD between the two Scapharca populations verified that this PCR-generated technique could be a profitable attempt for within- and between-population-grounded biological DNA scrutiny. The potential of PCR inquiry will be favorable in the selection of individuals and/or populations for several reproductive- and/or quarantine-connected characters in aquafarming manufacture.