• Animal cells and systems
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• 제3권1호
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• pp.29-39
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• 1999

Current data on reproductive characters of endemic and native species are essential to provide a strategy for the conservation of these species. Red pine (Pinus densiflora Sieb. & Zucc.) is one of the dominant, native tree species in Korea, but its reproductive ecology is not well-known. In 1997, the pattern of variation in cone and seed yields contributing to the conservation of declining populations of red pines was examined. Plant height and dbh were measured, and several new cones were collected from each tagged tree after counting the number of cones on each tree. For a subset of cones sampled, the number of fertile scales, the number of seeds at three development stages (early/late aborted, and filled seed), seed wing size, wing color, and individual filled seed mass were measured. The three sites which differed significantly in mean plant size also differed in mean cone and seed production per plant. However further analyses showed that most variation in characters examined occurred among plants within sites, but not among sites. An average of 90% of the potential seeds on the cones aborted at an early developmental stage, demonstrating that early abortion is a major factor affecting the number of filled seeds per cone. Individual seed mass was the only character which exhibited significant variations among sites as well as among trees within sites. Individual seed mass was overall negatively correlated with both the percentage of late abortion and the number of old cones per plant, suggesting that both the past and current years' reproductive activities have caused variations in seed mass. The potential dispersal distance of red pine seeds is quite large. However, wing loading was correlated with seed mass and number in a complex pattern across the sites. Distribution of seeds with varied colored wings differed among sites and among trees within sites. These results suggest that red pines at different sites might possess different strategies to cope with selection pressures acting during the final phase of reproduction, from seed dispersal to establishment. Then the ‘fitted’ red pine trees at each site should be identified and managed to conserve or restore populations.

• 한국초등과학교육학회지:초등과학교육
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• 제24권2호
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• pp.145-159
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• 2005

Students' alternative concepts of evolution are similar to misconcepts and disputes which scientists had in science history. The aims of this study are to analyze the elementary children's concept in evolution based on science history. Lee (2004)'s two tests were applied to 6th grade to investigate the children's evolution concepts and genetic concepts related to the historical development of the evolution concepts. The test results were analyzed in accordance with 4 stages of science history based on Lee (2004)'s method. These stages are divided to stage 1 (Before Lamarck), stage 2 (Lamarck), stage 3 (Darwin), stage 4 (After Darwin). The major results are as follows. Most of elementary school children are fixed to the stage 2. They usually do not show the consistency of evolution concepts in the three dimensional aspects such as mechanism, time, and subjects. Many children do not have concrete meaning of gene, inheritance, sexual reproduction, mutation and could not connect these concetps and process of evolution. Also, they believe the inheritance of acquired traits and spontaneous generation. Therefore it is confirmed that they still have similar misconcepts and disputes which scientists had in transition time between stage 2 and 3 and most of children already have strong Lamarckian thought acquired from daily life experience before learning about natural selection and evolution.

• 생태와환경
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• 제35권3호통권99호
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• pp.232-236
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• 2002

한국산 꺽지 번식에 대한 연구의 일환으로 정소 및 정자의 형태적 특징을 조사하였다. 2001년 5월부터 10월에 걸쳐 북한강 지류인 수입천 지역에 서식하는 꺽지(Corecperca　herzi)를 채집하여 분석하였다. 정소는 흰색을 띄며 쐐기모양을 하고 복강의 등쪽에 좌우 균등하게 발달하였다. 동일한 정자형성 단계에 있는 생식세포들이소낭세포에 싸여 발달하며 여러 개가 모여 소엽구조를　형성한다. 각 소엽은 여러 개의 소낭들로 구성되며 소낭들은 각각 속에 들어 있는 생식세포의 정자형성 단계가　상이하였다. 정자는 길이는 43 ${\mu}$m로 둥근 형태의 두부는 2.2 ${\mu}$m 길이이며 0.5 ${\mu}$m길이의 중편이 두부 밑에 발달한다. 미부의 길이는 40 ${\mu}$m이다. omassie brilliant blue염색 결과 정자의 두부 선단에 강한 염색을 확인하였는데 첨체를 발달시키는 것으로 사료된다.

• 한국발생생물학회지:발생과생식
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• 제23권1호
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• pp.35-42
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• 2019

Fish shows great difference in growth rate between individuals during larval development and early growth. This difference seriously reduces the production efficiency in fish culture. Growth hormone (GH)/Insulin-like growth factor 1 (IGF1) system is said to play some pivotal roles in fish growth. In this study, we investigated differences of GH, IGF1 and GHR gene expressions in juvenile red spotted grouper (Epinephelus akaara) with different growth performance. Red spotted groupers were reared under the same environmental condition (water temperature $24{\pm}1^{\circ}C$, natural light) for 96 days after hatching. They were divided into 3 groups by size (fast growing, middle growing and slow growing groups: FGG, MGG, and SGG, respectively). RNA was extracted from the brain, liver and muscle tissues from each group, and target gene expression was examined by real-time PCR. In the brain with pituitary gland, expression of GH gene in FGG was significantly higher than the expression in SGG, but the expression of IGF1 and GHR genes in the muscle was highest in SGG. Difference of GHR and IGF1 mRNA in the liver between groups with different growth performance was less clear than that in other tissues, although level of IGF1 mRNA was higher in SGG than in MGG. These results suggest that hormonal governing of growth is not the same in fast growing and slow growing fish, and size grading could cause a shift of hormonal state and growth pattern in this species.

• 한국발생생물학회지:발생과생식
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• 제23권2호
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• pp.129-138
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• 2019

In many cases, obesity is associated with metabolic disorders. Recently, natural compounds that may be beneficial for improving obesity have received increasing attention. Bitter melon has received attention as a diabetes treatment. $NAD^+$-dependent deacetylase (Sirtuin 1, SIRT1) has emerged as a novel therapeutic target for metabolic diseases. In this study, ethanol extract of bitter melon (BME) suppressed adipocyte differentiation and significantly increased the expression of SIRT1 in fully differentiated 3T3-L1 cells. Moreover, it enhanced the activation of AMP-activated protein kinase (AMPK). In high-fat diet (HFD)-fed induced-obesity mice, BME suppressed HFD-induced increases in body weight and white adipose tissue (WAT) weight. BME also increased the expression of SIRT1 and suppressed peroxisome proliferator-activated receptor and sterol regulatory element binding protein 1 expressions of WAT from HFD-fed mice. These findings suggest that BME prevents obesity by activating the SIRT1 and AMPK pathway and that it may be a useful dietary supplement for preventing obesity.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1491-1500
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• 2019

Objective: European pigs have been imported to improve the economically important traits of Thai pigs by crossbreeding and was finally completely replaced. Currently Thai indigenous pigs are particularly kept in a small population. Therefore, indigenous pigs risk losing their genetic diversity and identity. Thus, this study was conducted to perform large-scale genetic diversity and phylogenetic analyses on the many pig breeds available in Thailand. Methods: Genetic diversity and phylogenetics analyses of 222 pigs belonging to Thai native pigs (TNP), Thai wild boars (TWB), European commercial pigs, commercial crossbred pigs, and Chinese indigenous pigs were investigated by genotyping using 26 microsatellite markers. Results: The results showed that Thai pig populations had a high genetic diversity with mean total and effective ($N_e$) number of alleles of 14.59 and 3.71, respectively, and expected heterozygosity ($H_e$) across loci (0.710). The polymorphic information content per locus ranged between 0.651 and 0.914 leading to an average value above all loci of 0.789, and private alleles were found in six populations. The higher $H_e$ compared to observed heterozygosity ($H_o$) in TNP, TWB, and the commercial pigs indicated some inbreeding within a population. The Nei's genetic distance, mean $F_{ST}$ estimates, neighbour-joining tree of populations and individual, as well as multidimensional analysis indicated close genetic relationship between Thai indigenous pigs and some Chinese pigs, and they are distinctly different from European pigs. Conclusion: Our study reveals a close genetic relationship between TNP and Chinese pigs. The genetic introgression from European breeds is found in some TNP populations, and signs of genetic erosion are shown. Private alleles found in this study should be taken into consideration for the breeding program. The genetic information from this study will be a benefit for both conservation and utilization of Thai pig genetic resources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1765-1794
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• 2019

Genetic Programming (GP) is an intelligence technique whereby computer programs are encoded as a set of genes which are evolved utilizing a Genetic Algorithm (GA). In other words, the GP employs novel optimization techniques to modify computer programs; imitating the way humans develop programs by progressively re-writing them for solving problems automatically. Trial programs are frequently altered in the search for obtaining superior solutions due to the base is GA. These are evolutionary search techniques inspired by biological evolution such as mutation, reproduction, natural selection, recombination, and survival of the fittest. The power of GAs is being represented by an advancing range of applications; vector processing, quantum computing, VLSI circuit layout, and so on. But one of the most significant uses of GAs is the automatic generation of programs. Technically, the GP solves problems automatically without having to tell the computer specifically how to process it. To meet this requirement, the GP utilizes GAs to a "population" of trial programs, traditionally encoded in memory as tree-structures. Trial programs are estimated using a "fitness function" and the suited solutions picked for re-evaluation and modification such that this sequence is replicated until a "correct" program is generated. GP has represented its power by modifying a simple program for categorizing news stories, executing optical character recognition, medical signal filters, and for target identification, etc. This paper reviews existing literature regarding the GPs and their applications in different scientific fields and aims to provide an easy understanding of various types of GPs for beginners.

• 한국양봉학회지
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• 제33권4호
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• pp.261-268
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• 2018

Queen honey bees (Apis cerana) can be reared artificially on demand by the use of grafting technique. The technique consists of grafting young worker larvae into queen cell cups and raising in a queenless strong colony. As the age of grafted larvae for queen rearing exhibited several aspects related to quality and reproductive potential of queen, this study were conducted to investigate the influence of age of grafted larva on morphological characteristics and lifespan of queen, and the growth of colony she headed. Our results demonstrated that queens reared from young worker larvae (i.e., less than 1-day old larvae) were significantly larger in size (i.e., body weight and thorax width) than that of queens reared from 2-day old worker larvae. Moreover, queens reared from younger worker larvae initiated egg-laying earlier, stored more spermatozoa in spermatheca and had a longer lifespan compared to queens raised from older worker larvae. We also found a significant positive effect of queen grafting age on the production of worker and drone brood, adult worker population in colonies headed by queens reared from younger larvae. These findings suggested that rearing queens from brood grafted at the earliest possible age could increase the reproductive potential of queen as well as fitness of colony she head.

• 문화기술의 융합
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• 제4권4호
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• pp.331-335
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• 2018

천남성과에 속하는 Z antedeschia spp. 칼라는 절화로서 매우 인기가 높다. 다양한 색상을 지닌 유색칼라는 자연번식률이 낮고 고온에 취약하다는 문제로 식물 조직배양을 통한 대량 증식 체계를 확립하는 것이 매우 중요하다. 본 연구에서는 칼라 기내 식물체의 생육을 향상시키고자 타우린을 첨가하여 실험을 수행하였다. 식물 생장 효과로 타우린을 20 mg/L 첨가했을 때 다신초는 54.0 %의 발생을 보였고, 생체중은 17.2배가 증가하여 가장 높은 효율을 보였다. 식물 생장에 악영향을 주는 갈변화에서는 타우린 20 mg/L 처리구가 16.0 %로 무처리구의 39.2 %보다 약 2배 이상의 갈변이 억제된 것을 보였다. 타우린은 전반적인 칼라 식물 생장을 촉진시켜 칼라 경정의 대량 증식체계 확립에 긍정적인 영향을 줌으로써 우량품종의 효율적인 대량증식 및 농가 소득 향상에 도움이 될 것으로 판단된다.

• 한국재난정보학회 논문집
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• 제15권1호
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• pp.12-19
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• 2019

연구목적: 촛불화재는 매년 같은 유형으로 반복되어 사상자가 발생하고 있기에 화재조사결과를 바탕으로 주로 발생되는 형태를 재현실험을 통해 분석하여 동종의 화재를 줄이는데 목적이 있다. 연구방법: 촛불화재 분석을 위해 아크릴 재연실험, 포멕스(FOMEX) 아크릴 재연실험, 일반가연물 재연실험, 촛불의 자연소화 재연실험 등 4가지 방법으로 실시하였다. 연구결과: 주변에 가연물의 접촉이 없으면 지속적인 연소가 이루어지기가 힘들다는 것을 확인하였다. 결론: 촛불화재를 예방하기 위해서는 주변 안전확인이 무엇보다 중요하며 초 말단에 은박지와 같은 불연 재료로 마감 처리하는 등 안전규정을 도입하는 것도 하나의 방법이라고 생각한다.