• Molecules and Cells
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• 제45권5호
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• pp.273-283
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• 2022

During meiosis, homologous chromosomes (homologs) pair and undergo genetic recombination via assembly and disassembly of the synaptonemal complex. Meiotic recombination is initiated by excess formation of DNA double-strand breaks (DSBs), among which a subset are repaired by reciprocal genetic exchange, called crossovers (COs). COs generate genetic variations across generations, profoundly affecting genetic diversity and breeding. At least one CO between homologs is essential for the first meiotic chromosome segregation, but generally only one and fewer than three inter-homolog COs occur in plants. CO frequency and distribution are biased along chromosomes, suppressed in centromeres, and controlled by pro-CO, anti-CO, and epigenetic factors. Accurate and high-throughput detection of COs is important for our understanding of CO formation and chromosome behavior. Here, we review advanced approaches that enable precise measurement of the location, frequency, and genomic landscapes of COs in plants, with a focus on Arabidopsis thaliana.

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.283-294
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• 2007

Conventional culture-based methods of enumerating rumen microorganisms (bacteria, archaea, protozoa, and fungi) are being rapidly replaced by nucleic acid-based techniques which can be used to characterise complex microbial communities without incubation. The foundation of these techniques is 16S/18S rDNA sequence analysis which has provided a phylogenetically based classification scheme for enumeration and identification of microbial community members. While these analyses are very informative for determining the composition of the microbial community and monitoring changes in population size, they can only infer function based on these observations. The next step in functional analysis of the ecosystem is to measure how specific and, or, predominant members of the ecosystem are operating and interacting with other groups. It is also apparent that techniques which optimise the analysis of complex microbial communities rather than the detection of single organisms will need to address the issues of high throughput analysis using many primers/probes in a single sample. Nearly all the molecular ecological techniques are dependant upon the efficient extraction of high quality DNA/RNA representing the diversity of ruminal microbial communities. Recent reviews and technical manuals written on the subject of molecular microbial ecology of animals provide a broad perspective of the variety of techniques available and their potential application in the field of animal science which is beyond the scope of this treatise. This paper will focus on nucleic acid based molecular methods which have recently been developed for studying major functional groups (cellulolytic bacteria, protozoa, fungi and methanogens) of microorganisms that are important in nutritional studies, as well as, novel methods for studying microbial diversity and function from a genomics perspective.

• 대한지역사회영양학회지
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• 제21권1호
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• pp.1-11
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• 2016

Objectives: This study was conducted to evaluate the nutrition quotient (NQ) by gender and understand which factors influence NQ in preschool children. Methods: Subjects were 245 children (110 boys, 135 girls) aged 4-6 years and their parents. The questionnaire composed of demographic characteristics, eating behavior factors and the NQ questions. The NQ consisted of 19 food behavior checklist items and all items were grouped into 5 factors: balance, diversity, moderation, regularity, and practice. Inbody J05, a measurement device that measures individual's body composition was used to measure children's anthropometric data. All data were statistically analyzed by SPSS program (Ver. 20) and the statistical differences in variables were evaluated by Student t-test, ${\chi}^2-test$, One-way ANOVA and Duncan's multiple range test. Results: The total NQ score of the subjects was 65.3. The NQ score of girls (67.0) was significantly higher than that of the boys (63.2) (p<0.01). The girls' average scores of NQ factors including diversity (p<0.01) and practice (p<0.05) were higher than those of the boys. The analysis of related-factors influencing NQ scores showed that there was a significant difference among the groups according to feeding methods during infancy (p<0.05), breast feeding group being the highest. Furthermore, the NQ score showed a significant difference depending on how to correct children's unbalanced diet as well as parents' nutrition knowledge. The NQ score of obesity group tended to be lower than that of underweight group although there was no significant difference. Conclusions: Overall results indicated that the girls had better quality of diet and eating habits than the boys. Children and their parents need proper nutrition education and counseling to correct children's eating habits and to improve diet quality in kindergartens and in children care centers.

• 한국해양바이오학회지
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• 제12권1호
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• pp.59-65
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• 2020

Fish, caught by bottom trawling in the middle of the Yellow sea (east of Korea), in the spring and summer of 2016 were assessed for species composition and fluctuation in their abundance. The fish were studied at four research stations (St.) and were found to be composed of 46 species, 31 families, and 14 orders. The dominant species caught were Engraulis japonicus, Larimichthys polyactis, Johnius grypotus, Liparis tanakae, and Larimicthys crocea. All the species were assessed for their numbers, richness, diversity, and dominance to gain a measure of the biodiversity. The highest number of individuals was recorded at St. 4 (50,053 individuals), while the lowest number of individuals was recorded at St. 1 (44,090 individuals). The evenness index was the highest at St. 2 (E = 0.65) and lowest at St. 3 (E = 0.62). The diversity index was the highest at St. 4 (H' = 2.31) and lowest at St. 3 (H' = 2.23). Furthermore, the dominance index was the highest at St. 3 (D = 54.9%) and lowest at St. 2 (D = 47.7%).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권11호
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• pp.2866-2879
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• 2012

Among the various security threats in online games, the use of game bots is the most serious problem. Previous studies on game bot detection have proposed many methods to find out discriminable behaviors of bots from humans based on the fact that a bot's playing pattern is different from that of a human. In this paper, we look at the chatting data that reflects gamers' communication patterns and propose a communication pattern analysis framework for online game bot detection. In massive multi-user online role playing games (MMORPGs), game bots use chatting message in a different way from normal users. We derive four features; a network feature, a descriptive feature, a diversity feature and a text feature. To measure the diversity of communication patterns, we propose lightly summarized indices, which are computationally inexpensive and intuitive. For text features, we derive lexical, syntactic and semantic features from chatting contents using text mining techniques. To build the learning model for game bot detection, we test and compare three classification models: the random forest, logistic regression and lazy learning. We apply the proposed framework to AION operated by NCsoft, a leading online game company in Korea. As a result of our experiments, we found that the random forest outperforms the logistic regression and lazy learning. The model that employs the entire feature sets gives the highest performance with a precision value of 0.893 and a recall value of 0.965.

• Asian-Australasian Journal of Animal Sciences
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• 제33권4호
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• pp.539-546
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• 2020

Objective: The Jeju native pig (JNP) found on the Jeju Island of Korea is a unique black pig known for high-quality meat. To investigate the genetic uniqueness of JNP, we analyzed the selection signature of the JNP in comparison to commercial pigs such as Berkshire and Yorkshire pigs. Methods: We surveyed the genetic diversity to identify the genetic stability of the JNP, using the linkage disequilibrium method. A selective sweep of the JNP was performed to identify the selection signatures. To do so, the population differentiation measure, Weir-Cockerham's F_st was utilized. This statistic directly measures the population differentiation at the variant level. Additionally, we investigated the gene ontologies (GOs) and genetic features. Results: Compared to the Berkshire and Yorkshire pigs, the JNP had lower genetic diversity in terms of linkage disequilibrium decays. We summarized the selection signatures of the JNP as GO. In the JNP and Berkshire pigs, the most enriched GO terms were epithelium development and neuron-related. Considering the JNP and Yorkshire pigs, cellular response to oxygen-containing compound and generation of neurons were the most enriched GO. Conclusion: The selection signatures of the JNP were identified through the population differentiation statistic. The genes with possible selection signatures are expected to play a role in JNP's unique pork quality.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.445-452
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• 2004

Genetic diversity of sub-Saharan African goats was assessed using 19 microsatellite markers. Breeds were sampled from eastern Africa (Maasai, Kigezi, Mubende, North West Highland, Arsi-Bale), southern Africa (Ndebele, Pafuri) and West Africa (West African Dwarf, Maure, Djallonke). European breeds (Grisons Striped, Toggenburg), Asian breeds (Mongolian Cashmere, Bandipur) and a Middle East breed (Arab) were also included. The mean number of alleles per locus and average gene diversity ranged from 5.26$\pm$0.464 (Djallonke) to 7.05$\pm$0.516 (Mubende) and from 0.542$\pm$0.036 (Pafuri) to 0.672$\pm$0.031 (Ndebele), respectively. The between breeds variation evaluated using $$G_{ST}$$ and $\theta$ were found to account for 14.6% ($\theta$) and 15.7% ($$G_{ST}$$) of the total genetic variation. The $D_{A}$ measure of genetic distance between pairs of breeds indicated that the largest genetic distance was between Pafuri and Djallonke while the lowest genetic distance was between Arsi-Bale and North West Highland. A neighbour-joining tree of breed relationships revealed that the breeds were grouped according to their geographic origins. Principal component analysis supported the grouping of the breeds according to their geographic origins. It was concluded that the relationships of sub-Saharan African goat breeds were according to their geographical locations implying that the goats of eastern Africa, West Africa and southern Africa are genetically distinct. Within each sub-region, goat populations could be differentiated according to morphological characteristics.

• 환경생물
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• 제25권4호
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• pp.319-325
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• 2007

We monitored the butterfly community dynamics from March to October for the three years (2002, 2003, 2004). The study areas were consisted of the five sectors with pine forest (Pinus rigida) and mixed oak forests at Mt. Midong in Chungwongun, Chungchungbukdo, Korea. We found that the total numbers of butterfly species were 59 species and the total individuals were 1,513. There was no change the number of species (44 species) during the study period but the composition of species and the number of individuals were different such as 414, 561, and 538, respectively. The most abundant species were Minois dryas (25%) in 2002, Polygonia c-aureum (24%) in 2003, and P. c-aureum (22%) in 2004. On the contrary, the number of singleton species was 20 species in 2002, 15 species in 2003, and 15 species in 2004. We found that there was the seasonal difference in species composition of butterfly community. The species diversity of butterfly community was the highest at sector 4 and sector 5 and lowest at sector 2. Main reason of the butterfly dynamics was strongly supposed to the human activity. We could suggest that the butterfly monitoring study must be a good way to measure the change of butterfly habitats including anthropogenic activity and the natural disturbances.

• Journal of Nutrition and Health
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• 제41권2호
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• pp.174-183
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• 2008

제3기 (2005년) 국민건강영양조사 자료를 이용하여 분석한 결과 연구 대상자의 과반수에서 식품확보가 불안정하였으며, 식품안정성은 식사섭취와 관련이 있어 식품확보가 불안정한 군에서 영양소 섭취량이 낮고 섭취 식품의 다양성이 적었다. 본 연구는 우리 국민의 식품안정성과 식사섭취의 관련성에 대한 거의 초기 연구로 식품확보에 대한 안정성의 문제 크기를 파악하고 식품확보 여부에 따른 식사섭취의 양적${\cdot}$질적 측면을 다루었다. 이와 함께 식생활은 건강과 밀접한 관련이 있으므로 식품안정성과 건강 및 질병에 관한 후속 연구가 필요하며, 이러한 연구 결과에 근거하여 향후에는 저소득층의 안정적인 식품확보를 지원하는 정책을 마련하고 시행중인 정책의 효과 평가와 개선 방안을 모색할 필요가 있겠다.

• 국제초고층학회논문집
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• 제6권2호
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• pp.165-175
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• 2017

The importance of designing urban building complexes so that they obtain 'urban' power, rather than become isolated from the surrounding urban context, has been well recognized by both researchers and practitioners. Nevertheless, most current discussions are made from architects' personal experiences and intuition, and lack a quantitative understanding, to which obstacles include an in-depth exploration of the 'urban' power between building complexes and the urban environment. This paper attempts to measure this feature of 'urban', i.e., 'urbanity,' through a new analytical approach derived from the opendata environment. Three measurements that can be easily collected though the Google Maps API and Open Street Map are applied herein to evaluate high or low values of urbanity. Specifically, these are 'metric depth', i.e., the scale of extended public space, 'development density', i.e., density and distribution of point of interests (POIs), and 'type diversity', i.e., diversity of different commercial types. Six cases located in Japan, China and Hong Kong respectively are ranked based on this analytical approach and compared with each other. It shows that Japanese cases, i.e., Osaka Station City and Namba Parks, Osaka, obtained clearly higher values than cases in Shanghai and Hong Kong. On one hand, the insight generated from measuring and explaining 'urban' power would help to assist better implementation of this feature in the design of urban building complexes. On the other hand, this analytical approach can be easily extended to achieve a large-scale measurement and comparison among different urban building complexes, which is also helpful for design practitioners.