• Korean Journal of Environment and Ecology
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• v.19 no.3
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• pp.269-278
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• 2005

The dynamics and distribution characteristics of Coryjopsis coreana popujation at Cheongsogol, Sunchon, Cholanam-do, Korea, were investigated. The Coryiopsis coreana pop ulation was distributed along the forest edge and it showed characteristics which were distributed on only directional slopes of the north, northeast or northwest. The Coryjopsis coreana constituted subtree or shrub layer in the forest, and its floristic composition was basically similar to those of adjacent areas where the species does not exist. The number of stump was 6.25 per $25\;m^2$, and each stump had 3 sproutings in average. The density of the Corylopsis coreana population in the study area was lower than that in other area, which suggests the population is declining in the study area.

• Ocean and Polar Research
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• v.36 no.1
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• pp.49-57
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• 2014

The seabird plays an important role as one of the indicator species for the status of and changes within marine ecosystems. Therefore, the conservation of seabirds and their habitats is important for maintaining the structure and function of marine ecosystems. Biological invasions affect most ecosystems on oceanic islands. In particular, Rattus spp. is the invasive species with the greatest impact on the seabird population. Introduced predators, like rats, severely affect seabirds and endanger them worldwide. The breeding population of Streaked Shearwaters Calonectris leucomelas in Sasu Island is one of biggest seabird colonies in Korea, and the Norway Rat Rattus norvegicus is known as an alien predator in this island. In this study we investigated rates of burrow occupancy and breeding success of Streaked Shearwaters for 7 years, and the impact of Norway Rats on the breeding success of Streaked Shearwaters breeding in Sasu Island for 4 years. Our results show that the percentage of breeding burrows decreased according to breeding stage during several years in the monitoring period, and that predation by the Norway Rat was the main cause in hatching failures. Consequently, although our results indicate that their breeding population is not likely to decline, Norway Rats have been affecting the breeding status of Streaked Shearwaters on Sasu Island during the last decade.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.153-161
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• 2008

Agriculture and forest are basis for livelihood in Nepal while both sectors constitute around 40 percent of the national product and over two-thirds of the economically active population is dependent on agriculture. However, radical changes in land use, depletion in crops production and food availability are major threats due to loss of soil fertilityand severe environmental degradation. In this study, we used time series data from 1986/87 to 2005/06 about food crop production and population published by Government of Nepal, Ministry of Agriculture and Cooperatives and Central Bureau of Statistics. Descriptive statistics and ArcGIS were used to assess and map the food security status of Nepalese Terai based on the local food demand and supply system. Food supply to demand ratio(FSDR) was the main idea of assessment. Our results showed that out of 20 districts, only 8 districts were categorised under secured food districts whereas 5 districts were still under food unsecured situation. The analysis further revealed that 7 districts had faced food deficit more than 8-16 times during the last 20 year periods. Data further showed that there was surplus food supply relative to the requirements dictated by FSDR. However, the average FSDR was less than 1.2(less than 20% surplus) exploring fact that most of the districts were not producing sufficient food to cope up the food shock and after 1995 it was relatively stagnant. Our prediction reveals that food supply in Terai even in the future would remain at almost the same level as now, and there will not more than 16-17% surplus by 2021 considering medium vibrant population growth. The findings thus, indicate that Terai may not be a food secure region in the future, even though the region is considered as a food storage house of Nepal. In addition, this paper suggests ways to make future comprehensive case studies more widely comparable in Terai, Nepal.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.156-162
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• 2008

Five microsatellite DNA markers were used to investigate genetic diversity and population structure of olive flounder Paralichthys olivaceus collected from four locations (YD, SC, GJ, WD) where hatchery-based seeds of the flounder have been released. The average of observed (Ho) and expected heterozygosity (He) ranged from 0.833 to 0.871, and from 0.842 to 0.876, respectively. The average number of alleles per locus ranged from 12.4 to 17.8. The proportion of stocked flounder ranged from 20.0% to 95.8% for wild-caught populations with a decreasing tendency of alleles per locus following a higher proportion of stocked flounder. There is need to implement a more careful stock-enhancement program of hatchery-based seeds and to monitor its genetic effects on wild populations to ensure conservation of natural flounder resources.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.311-315
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• 2012

The increasing demand for Korean native chicken meat indicates that the discovery of haplotypes is very important from both economic and conservation points of view. In this study, mtDNA D-loop sequences from two crossbred Korean native chicken populations of 138 individuals were investigated. Twenty six nucleotide substitutions were identified from sequence analysis and were classified into 12 haplotypes. The haplotype H_8 represents 73.47% of Woorimatdag (chicken population) sequences, which were identified in all five Woorimatdag chicken populations investigated. The H_7 haplotype (Dhap1) for D population covers 45% sequences, which indicate maternal inheritance from black Korean native chicken. On the other hand, Chap3 and Chap4 for C population are specific haplotypes, as H_5 and H_2, respectively. Based on the network profiles, six SNPs (C199T, A239G, G242A, A291G, T330C and C391A) of the D-loop region are effective markers for discrimination between Woorimatdag and Hanhyup chicken populations. Also, the phylogenetic analyses of Woorimatdag and Hanhyup chicken populations were used to identify the genetic relationships among the haplotypes. The results presented here can be used for developing molecular markers to discriminate between two commercial Korean native chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.314-319
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• 2008

Duck (Anas platyrhynchos) is one of the most important domestic avian species in the world. In the present research, fifteen polymorphic microsatellite markers were used to evaluate the diversity and population structure of 26 Chinese indigenous duck breeds across the country. The Chinese breeds showed high variation with the observed heterozygosity (Ho) ranging from 0.401 (Jinding) to 0.615 (Enshi), and the expected heterozygosity (He) ranging from 0.498 (Jinding) to 0.707 (Jingjiang). In all of the breeds, the values of Ho were significantly lower than those of He, suggesting high selection pressure on these local breeds. AMOVA and Bayesian clustering analysis showed that some breeds had mixed together. The FST value for all breeds was 0.155, indicating medium differentiation of the Chinese indigenous breeds. The FST value also indicated the short domestication history of most of Chinese indigenous ducks and the admixture of these breeds after domestication. Understanding the genetic relationship and structure of these breeds will provide valuable information for further conservation and utilization of the genetic resources in ducks.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3911-3916
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• 2012

Background: The objective of this study WAS to describe cancer incidence rates and trends among THE Hong Kong population for the period 1983-2008. Methods: Incident cases and population data from 1983 to 2008 were obtained from the Hong Kong Cancer Registry and the Census and Statistics Department, respectively. Agestandardized incidence rates (ASIR) were estimated and joinpoint regression was applied to detect significant changes in cancer morbidity. Results: For all cancers combined, the ASIR showed declining trends (1.37% in men, 0.94% in women), this also being the case for cancers of lung, liver, nasopharynx, stomach, bladder, oesophagus for both genders and cervix cancer for women. With cancer of thyroid, prostate, male colorectal, corpus uteri, ovary and female breast cancer an increase was evident throughout the period. The incidence for leukemia showed a stable trend since early 1990s, following an earlier decrease. Conclusion: Although overall cancer incidence rates and certain cancers showed declining trends, incidence trends for colorectal, thyroid and sex-related cancers continue to rise. These trends in cancer morbidity can be used as an important resource to plan and develop effective programs aimed at the control and prevention of the spread of cancer amongst the Hong Kong population. It is particularly useful in allowing projection of future burdens on the society with the increase in certain cancer incidences.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.35-42
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• 2004

To examine the species composition and population fluctuation of butterflies at Mt. Yudal, Mokpo, we collected butterflies from May, 2001 to April, 2002 by dividing the study site into four subyegions. As a result, seven families comprising 40 species were identified. The patterns of population fluctuations at the four subregions showed that the lower the elevation the higher the number of species and individuals. Monthly fluctuations of buttefly species produced an M-shaped curve, whereas those of individuals produced a monotonic curve with a maximum peak during August. To see effectively the changes of numbers of species and individuals, we calculated the indices of species richness and evenness by subregions and months. As a result, both indices fulfilled the primary criterion of independence and showed more or less negative association: when heterogeneity is higher, evenness is lower. Examination of butterfly populations over long-term periods might provide an evidence of global warming and a guideline to conserve and manage habitats.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.75-81
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• 2017

A total of 340 individuals from seven duck populations were studied using 24 polymorphic microsatellite (MS) markers to identify plumage colors with genetic diversity. The estimated average number of alleles (Na), polymorphic information content (PIC) value, and expected heterozygosity (He) per locus of all populations were 11.5, 0.602, and 0.635, respectively. The calculated population genetic distance (Fst), inbreeding coefficient of individuals within duck populations (Fis), and total inbreeding among populations (Fit) were 0.135, 0.105, and 0.229, respectively. Statistical analyses for each population using 24 marker combinations, revealed that the estimated average number of effective alleles (Ne), observed heterozygosity (Ho), and fixation index of inbreeding within populations (F) were 3.129, 0.505, and 0.104, respectively. The results of genetic distance and phylogenetic analysis revealed that Korean native duck populations were clearly separated from all Bangladeshi duck populations. Moreover, all populations clustered well according to their genetic distance, but could not be clearly separated according to black and white plumage colors or plumage color pattern. The combination of these 24 MS markers can be used for discrimination and determination of the genetic diversity of native duck breeds in further investigations for conservation and special development purposes.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.82-87
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• 2008

Marine fisheries are important natural resources and must be maintained, especially fish species that are important sources of food. Despite the increase in stocking programs to maintain fisheries with artificially raised fish, the genetic impact stocking has on the wild fry population has not been addressed. Genetic variation in rock bream, Oplegnathus fasciatus, within and between wild-caught parents and the $F_1$ generation produced by them in 1 day was assayed using nine highly variable micro satellite markers. The nine micro satellite loci used in this study displayed diverse polymorphisms, and in total, 98 different alleles were observed over all loci. Differences in genetic variability of the $F_1$ offspring compared to their wild-caught parents (brood stock) were observed in terms of allele frequency, gene diversity, and heterozygosity. Although the $F_1$ generation of rock bream was missing 16% of the micro satellite alleles, no significant reduction was found in mean heterozygosity of the $F_1$ population compared to the brood stock. Eight of nine loci showed significant Hardy-Weinberg equilibrium (HWE) deviations in the $F_1$ population, while the brood stock deviated from HWE at three micro satellite loci (KOF85, KOF360 and KOF374). These deviations showed mostly a deficit of heterozygotes. Our results provide evidence for genetic differences in the $F_1$ hatchery offspring compared to their wild-caught parents and reinforce the need for a series of consecutive egg collections to avoid the loss of genetic variability. This also further underscores the importance of monitoring genetic variability of hatchery populations for the conservation of natural rock bream resources.