• Animal Bioscience
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• 제34권4호
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• pp.525-532
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• 2021

Objective: Old World camels are a valuable genetic resource for many countries around the world due to their adaptation to the desert environment. At present, Old World camels have encountered the challenge of unprecedented loss of genetic resources. Through our research, we would reveal the population structure and genetic variation in Old World camel populations, which provides a theoretical basis for understanding the germplasm resources and origin and evolution of different Old World camel populations. Methods: In the present study, we assessed mtDNA control region sequences of 182 individuals from Old World camels to unravel genetic diversity, phylogeography, and demographic dynamics. Results: Thirty-two haplotypes confirmed by 54 polymorphic sites were identified in the 156 sequences, which included 129 domestic and 27 wild Bactrian camels. Meanwhile, 14 haplotypes were defined by 47 polymorphic sites from 26 sequences in the dromedaries. The wild Bactrian camel population showed the lowest haplotype and nucleotide diversity, while the dromedaries investigated had the highest. The phylogenetic analysis suggests that there are several shared haplotypes in different Bactrian camel populations, and that there has been genetic introgression between domestic Bactrian camels and dromedaries. In addition, positive values of Tajima's D and Fu's Fs test demonstrated a decrease in population size and/or balancing selection in the wild Bactrian camel population. In contrast, the negative values of Tajima's D and Fu's Fs test in East Asian Bactrian camel populations explained the demographic expansion and/or positive selection. Conclusion: In summary, we report novel information regarding the genetic diversity, population structure and demographic dynamics of Old World camels. The findings obtained from the present study reveal that abundant genetic diversity occurs in domestic Bactrian camel populations and dromedaries, while there are low levels of haplotype and nucleotide diversity in the wild Bactrian camel population.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.45-51
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• 2011

A low acid phosphatase 3 (lap3) mutant was identified and characterized from an Arabidopsis activation-tagged (Weigel) population. The roots of the lap3 plants showed lower acid phosphatase (APase) activity compared to wild-type ones under low-Pi conditions ($10{\mu}M\;Pi$). Plasmid rescue experiments revealed that the activation-tagging vector was inserted into the intergenic region between At4g31540 and At4g31550 in the Arabidopsis genome. The genotypic segregation of the lap3 mutation was tightly linked with the phenotypic segregation of root APase activity in the prgeny of lap3. The transcript level of the At4g31520 (SDA1: SEVERE DEPOLYMERIZATION OF ACTIN 1), located 7.4 kb from the CaMV 35S enhancers in the lap3 mutant, was significantly reduced compared to that in the wild type. It was speculated that cellular actin polymerization may be involved in Pi acquisition in higher plants.

• 한국작물학회지
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• 제63권1호
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• pp.1-7
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• 2018

Information on the patterns of genetic diversity and population structure is essential for the rational use and efficient management of germplasms; accurate information aids in monitoring germplasms, and can also be used to predict potential genetic gains. In this study, we assessed genetic diversity, focusing on Korean rice accessions for theand their sustainable conserved diversity. Using DNA profiling with 12 simple sequence repeat (SSR) markers, we detected a total of 333 alleles among 2,016 accessions. The number of alleles ranged from 21 to 53, with an average of 27.8. Average polymorphism information content was 0.797, with the lowest being 0.667 and the highest 0.940. CA cluster analysis and the model-based population structure revealed two main groups that could be subdivided into five subgroups. Analysis of the molecular variance study based on the SSR profile data showed 5% variance among the profiles, whereas we recorded 93% variance among individuals and 2% variance within individuals. Specifically, the utilized diversity for of the breeding program is restricted in that cultivars were located in limited clades. These results revealed that preserving the diversity of Korean landraces could be useful sources for breeding new rice cultivars, and cwould be the basis for the sustainable conservation and utilization of a Korean rice germplasm.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2020년도 춘계학술대회
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• pp.155-155
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• 2020

• 한국작물학회:학술대회논문집
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• 한국작물학회 2020년도 춘계학술대회
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• pp.154-154
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• 2020

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.121.1-121
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• 2003

Dispersal of Xanthomonas axonopodis pv. citri, causing citrus bacterial canker disease on Unshiu orange was investigated at previously infested plots at Seogwipo in Jeju island of Korea. The bacterial pathogen overwintered in lesions started to multiply at tate May, and disease firstly observed one month after detection of phage from lesions. The disease gradually increased, however, it dispersed non-directionally to nearby plants from inoculum sources. Diseased plants were aggregated to form a cluster throughout the experiment. Population dynamics of phage on symtomless leaf surface and the disease severity were compared in the nursery, Increase of phage population on symptomless leaf surface preceded one month to that of the disease severity Population of phage increased constantly from late July to October, however, the disease severity decreased from late August to late October. It was assumed that the decrease of disease severity might be due to disease-induced defoliation.

• 농촌계획
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• 제9권4호
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• pp.9-18
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• 2003

The objectives of the study are to improve techniques for social impact assessment and to suggest their measuring methods to apply in small scale rural development projects. Population, residence, industries, and traffic volumes were selected to measure the social and economic impact assessment of Seongeup agricultural water development project in Jeju Province. Existing data gathering methods were used to estimate the changes of population and traffic volumes. Interview schedule for villagers was applied to estimate the residents' satisfaction to living environments. Interview schedule for experts was applied to estimate agricultural productivity and land price. The results of social and economic impact assessment show that there will be considerable changes in living environments, agricultural productivity, and land price. On the contrary, the project will make little impacts on the changes of population, em-ployment, and traffic volumes.

• 한국농공학회논문집
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• 제62권5호
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• pp.1-13
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• 2020

The empty houses' problem is important in the local revitalization and local sustainability, and these phenomenon caused by various factors of the region. The population and housing census data are the most effective data available to study this phenomenon by small regions. In this study, logistic regression and multiple regression analysis were performed to understand the effects of population, household, and housing characteristics on empty houses using population and housing census data. Also, the scale and direction of the effect of each characteristic in large cities, small cities, and rural areas were compared. As results, there was a slight difference between cities and province regions in the district and housing characteristic variables. In the comparison of Eup-Myeon-Dong, the affected variables were different in the Dong and Myeon areas. The significance of this study is to examine the effect of the characteristics of population and housing on the vacant houses and to confirm that the factors affecting different regions.

• 대한인간공학회지
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• 제30권4호
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• pp.525-534
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• 2011

This paper describes the current status of musculoskeletal disorders(MSDs) and its ergonomic risk factors, including the preventive intervention in terms of the working conditions and health promotion among agricultural workers. Korean agricultural workers have been exposed to the poor working condition. They have suffered from a variety of work-related injury and diseases more than the general population or the other occupational group. MSDs are one of the most prevalent problems threatening the agricultural worker's health and quality of life. Low back pain, osteoarthritis of hip and knee joint and carpal tunnel syndrome are well known MSDs that was found easily and frequently among agricultural workers. MSDs are worsened by poor ergonomic working conditions such as heavy weight lifting, repetitive movement and awkward posture which involves squatting with long sitting work on the ground, long working hours and heavy workload which are inherent in the greater part of agricultural works. Even though Korean agricultural workers are very weak population in terms of occupational safety and health, no many studies were conducted in the past and no many social and institutional supports were provided sufficiently. We need more interests and efforts in agricultural fields to improve its working condition and to promote health status of agricultural workers.

• 농촌계획
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• 제22권3호
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• pp.119-129
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• 2016

The aim of this study is to suggest the quantitative standard of a marginal village. For the purpose, the study selected 43 villages with the population of 50 or less, the classification of a marginal village in accordance with advanced research and 47 villages with the population over 50 in Buyeo-gun region. The common reason of occurrence of a marginal village suggested by advanced research is a characteristic of a village or decline and extinction of a village rather than a simple index of population or aging rate. Therefore, the study assumed that decline of functions of the village would be caused by decline a function of communities consisting of the villagers. The study then assumed that the relatively low or 0 number or rate of participants would result in community functions. The study conducted t-test on basis of population and aging rate and an analysis to find the range with relatively large differences in the number of communities, participants and the rate of the participants, etc. The result showed that the community function began to decline when the population was less than 60~70 and the aging rate over 75%~85%. As the decline of functions of communities began in population of 70, the critical point was met when the population was 40 or less. With population of 40 or less, the young and the old group communities became extinct or showed rapid decrease in the number of participants. The study assumed that decline of functions of a village, a reason of occurrence of a marginal village would be decline of functions of communities, but there was no further analysis on decline or extinction of a village with population of 40 or less. There shall be further studies about whether a village of population of 40 or less is led to decline of a function or extinction of village communities.