• Horticultural Science & Technology
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• v.16 no.2
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• pp.247-250
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• 1998

This study was carried out to investigate the effects of changes of ionic strength according to growth stage on growth and flowering of Dendranthema grandiflorum (Ramat.) Kitamura 'Seiun' grown hydroponically in perlite. The stage I, II, and III covered early vegetative growth (27-40 days after planting), latter vegetative growth (41-54 days), and reproductive growth (55-80 days), respectively. The 2 strength (1S and 2S) of nutrient solution were treated in stage I, whereas 3 strengths (1S, 1-2S, and 2S) were treated in stage II. Then, total 9 treatments in stage III were designated by 3 treatments (tap water, 1S, and 2S) for each 3 strengths in stage II. Each nutrient solution was applied 8 times per day. At vegetative growth stage (54 days after planting), stem length was highest when irrigated 8 times a day with 1S nutrient solution. Both photosynthesis and transpiration rate were higher in 1S than those in other treatments (1-2S, 2S), whereas leaf chlorophyll content was highest in 2S treatment. Ion content of plant treated with 2S was higher than other treatments. Growth (plant height, leaf area, stem length), fresh weight, and dry weight of each plant organ after flower bud formation were better in tap water treatment (1-1-0) than other 1S treatments (1-1-1, 1-1-2). Regarding the number of days to flowering, tap water treatment was the most effective. Thus, after flower bud formation supplying tap water or lower concentration of nutrient solution than those used during the vegetative growth stage was economical in saving chemical fertilizers, shortening the number of days to flowering, reducing salt accumulation in media, saving efforts of leaching, and reducing ground water contamination.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.114-123
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• 2015

Plants can respond and adapt to cold stress through regulation of gene expression in various biochemical and physiological processes. Cold stress triggers decreased rates of metabolism, modification of cell walls, and loss of membrane function. Hence, this study was conducted to construct coexpression networks for time-based expression pattern analysis of genes related to cold stress in Chinese cabbage (Brassica rapa ssp. pekinensis). B. rapa cold stress networks were constructed with 2,030 nodes, 20,235 edges, and 34 connected components. The analysis suggests that similar genes responding to cold stress may also regulate development of Chinese cabbage. Using this network model, it is surmised that cold tolerance is strongly related to activation of chitinase antifreeze proteins by WRKY transcription factors and salicylic acid signaling, and to regulation of stomatal movement and starch metabolic processes for systemic acquired resistance in Chinese cabbage. Moreover, within 48 h, cold stress triggered transition from vegetative to reproductive phase and meristematic phase transition. In this study, we demonstrated that this network model could be used to precisely predict the functions of cold resistance genes in Chinese cabbage.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.197-203
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• 2006

Parabens are most wildly used in food, cosmetics and pharmaceutic products as preservatives caused of safety and cheap. we had examined that paraben had estrogenic activity through the in vivo and in vitro experiments in last year. We demonstrated that most of parabens(ethyl, butyl, propyl, isobutyl, isopropyl) increased significantly uterus weight as well as induced proliferation of MCF-7 cell and binding of estrogen receptor as endocrine disrupter compounds. In this study, we evaluated that whether parabens have effect on male reproductive system or not. the male rats were administrated parabens by oral injection then examined separation of preputial day for $PND23\simPND52$. As the results, most parabens delayed pubertal development compare to control group. The separation of preputial day of Butyl and Propyl parabens at high concentration were PND 44 days and PND 45days compared to control group as PND 40 days. Even though, parabens as endocrine disrupter wildly spread in food, cosmetics and pharmaceutic products, we didn't have the safe guideline. In abroad, they are re-evaluating safety assessment for parabens. In conclusion, parabens delayed pubertal development in juvenile parabens are consider as endocrine disrupter chemicals.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.179-185
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• 2010

This study was carried out to investigate the optimal culture conditions for gametophytes growth and sporophytes regeneration of Pyrrosia linearifolia in order to provide for the masspropagation system foundation of Pyrrosia linearifolia using their life cycle. Among many different media, 2MS medium was most effective in prothallus proliferation. Prothallus growth was promoted as the total concentration of nitrogen sources increased, and the best result was observed on 120 mM nitrogen. The best concentration of sucrose was 3%. The addition of 5~20 mM IAA, NAA, BA and kinetin promoted the propagation of prothallus. But 2iP demonstrated the most inhibitory effect on prothallus proliferation. Gametophytes shaking-cultured with liquid medium showed similar growth with solid medium and normal formation of reproductive organs. Shoot regeneration was most effective on 1/8MS medium, but growth was promoted on 1/2MS medium. For promotion of shoot regeneration and growth, the suitable concentrations of sucrose and $NaH_2PO_4$ were 1% and $50{\sim}100mg{\cdot}mL^{-1}$ in 1/8MS medium, respectively.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.344-354
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• 2019

In seven species of Korean Asarum, 44 qualitative and 28 quantitative characters were reviewed taxonomically. Among 44 qualitative characters observed in vegetative and reproductive organs, the states of 27 characters were common in all the seven species. Among 28 quantitative characters, five characters have the same values in all the seven species; the number of cataphyll (2-4), leaf (2), calyx lobe (5), stamen (12) and pistil (6). White spots on adaxial surface of leaf (effectively) distinguished A. maculatum and A. versicolor from the other species. Many long soft hairs on abaxial surface of leaf distinguished A. mandshuricum from other species with short hairs. The glandular hairs on inner surface of calyx tube were divided into 2 types, reflecting the taxonomic relationships between the species: Type 1 has non-stalked glandular hairs (A. maculatum, A. sieboldii and A. sp.), and Type 2 has stalked glandular hairs (A. patens, A. versicolor, A. mandshuricum and A. misandrum). The length, shape, colour of calyx lobe and the extent to which the calyx lobe recurves, as well as the diameter and colour of calyx tube throat, were confirmed to be taxonomically valuable. In the case of glandular hair density on the surface of calyx lobe, A. patens with low density and A. sp. with high density were clearly distinct from all the other species with intermediate hair density. Meanwhile, the stylar protuberance length of A. patens (2.9-3.3 mm) was strikingly different from other species (1.4-2.5 mm). Additionally, further examination of the identities of A. yeonbyeonense and A. yeonbyeonense var. viridiluteolum is required.

• Animal cells and systems
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• v.4 no.4
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• pp.329-336
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• 2000

Life table experiments were performed in order to examine the effects of food quality on Moina macrocopa fed with four kinds of algal foods, Botryococcus sp., Scenedesmus subspicatus, Selenastrum capricornutum, and Chlorella sp., at $20^{\circ}C$ . The temperature effects on M. macrocopa were also assessed, feeding Chlorella at $17^{\circ}C$,$20^{\circ}C$,$25^{\circ}C$, and a combination of $28^{\circ}C$ (light) and $25^{\circ}C$ (dark). The cartilaginous Botryococcs cells were Inappropriate food for Moina. Among the foods tested, Chlorella was the food of the best quality in all accounts of life history traits. Moina grown on Chlorella showed higher net reproductive rate ($R_0$), longer mean and maximum longevities, earlier mean age at maturity, longer mean carapace length at maturity, larger mean clutch size, and shorter mean time interval between clutch productions than those grown on Selenastrum and Scenedesmus. An optimal temperature for Moina was $20^{\circ}C$ . When Moina were grown on Chlorella at $20^{\circ}C$, they showed the highest r, the highest $R_0$, the shortest T, the longest mean longevity, the earliest mean age at maturity, the longest mean carapace length at maturity, and the largest mean clutch size. The results of life table experiments showed that the individual and population growth patterns were much more affected by low temperature $17^{\circ}C$, than by high temperature ($\geq 20^{\circ}C$). In the optimal condition, the r value was very high, 5.1 in $d^{-1}$. In conclusion, the food quality and the temperature are the most important factors to govern the size and continuity of Moina population, by which the individual growth rates and reproductivity of members in the population can be controlled to survive in their environment such as small and temporary water bodies in nature.

• The Journal of Korean Society for School & Community Health Education
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• v.21 no.1
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• pp.47-60
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• 2020

서론: 청소년기는 여러 생물학적 변화 및 사고방식의 발전과 함께 성행위가 나타나기 시작하는 인간성장의 단계이다. 쿠바를 포함한 많은 라틴아메리카 국가들은 청소년들의 성관계 조기 시작과 같은 위험한 성행동을 보고해 왔다. 이 연구의 목적은 사회 인구 통계학적 요소, 정보 수단 및 쿠바의 십대 학생의 성적 행동에 영향을 미치는 행동 요소 사이의 관계를 확립하는 것이다. 방법: 본 연구를 위해 쿠바 십대들의 생식 및 성적 행동 경향 파악을 위해 설문조사를 실시했다. 전체 260명 중 성경험 여부에 응답한 232명에 대해 인구사회학적 특성의 파악과 성 관련 정보수집수단, 행동적 요인과 성행동 사이의 연관성분석을 위해 회귀분석을 실시했다. 결과: 대상자들의 평균 연령은 16.9세이고 대다수는 여성(64.2%)이었다. 232명 중에 45.3%는 무신론자, 31.2%는 유신론자이었다. 종교의 중요도에 대한 생각은 39.2%가 종교가 중요하지 않다고 응답했고 34.0%는 중요하다고, 14.0%는 종교가 매우 중요하다고 응답했다. 응답자 232명 중 80.5%의 십대들이 성관계 경험이 있다고 하였으며 첫 성관계 평균 연령은 14.65세였다. 피임약을 사용한 비율은 63.8%이었다. 인구사회학적 특성 중에 성별은 성관계와 통계적으로 유의미한 연관성을 나타냈으며, 남성은 여성보다 성관계를 가질 가능성이 3.8 배 더 높았다. 또한, 종교는 성관계와 관련이 없었다. 그러나 나이는 통계적으로 유의미한 것으로 나타났으며, 나이가 한 살 많아질수록 성관계 가능성은 2.29배 증가함을 알 수 있었다. 성 관련 정보수집수단과 관련하여 친구와 학교의 성교육 커리큘럼이 청소년들의 성행동을 결정하는 중요한 요인이었다. 결론: 쿠바 십대들의 연령과 성별은 성행동의 중요한 결정요인으로 나타났다. 또한, 쿠바의 십대들은 친구와 학교로부터 성에 대한 정보를 수집하고 있으므로 학교에서 보다 종합적인 성교육 프로그램을 만드는 등의 십대들의 성행동 문제를 다룰 때 영향요인들을 고려해야 할 것이다.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.684-689
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• 2021

In this paper, we develop a cost effective and disposable voltammetric sensing platform involving screen-printed carbon electrode (SPCE) modified with the nanocomposites composed of multi-walled carbon nanotubes, polyelectrolyte, and tyrosinase for bisphenol A. This is known as an endocrine disruptor which is also related to chronic diseases such as obesity, diabetes, cardiovascular and female reproductive diseases, precocious puberty, and infertility. A negatively charged oxidized multi-walled carbon nanotubes (MWCNTs) wrapped with a positively charged polyelectrolyte, e.g., polydiallyldimethylammonium, was first wrapped with a negatively charged tyrosinae layer via electrostatic interaction and assembled onto oxygen plasma treated SPCE. The nanocomposite modified SPCE was then immersed into different concentrations of bisphenol A for a given time where the tyrosinase reacted with OH group in the bisphenol A to produce the product, 4,4'-isopropylidenebis(1,2-benzoquinone). Cyclic and differential pulse voltammetries at the potential of -0.08 V vs. Ag/AgCl was employed and peak current changes responsible to the reduction of 4,4'-isopropylidenebis(1,2-benzoquinone) were measured which linearly increased with respect to the bisphenol A concentration. In addition, the SPCE based sensor showed excellent selectivity toward an interferent agent, bisphenol S, which has a very similar structure. Finally, the sensor was applied to the analysis of bisphenol A present in an environmental sample solution prepared in our laboratory.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.503-524
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• 2021

A largemouth bass (Micropterus salmoides) is an ecosystem disturbance fish species at the highest rank in the aquatic ecosystem, causing a serious imbalance in freshwater ecosystems. Although various attempts have been made to eradicate and control largemouth bass, no effective measures were found. Therefore, it is necessary to find an approach to maximize the effective population reduction based on the unique characteristics of largemouth bass. This study used the transcriptome analysis to derive 182,887 unigene contigs and select 12 types of final target sequences for applying the CRISPR/Cas9 system in the genes of IZUMO1 and Zona pellucida sperm-binding protein, which are proteins involved in sperm-egg recognition. After synthesizing 12 types of sgRNA capable of recognizing each target sequence, 12 types of Cas9-sgRNA ribonucleoprotein (RNP) complexes to be used in subsequent studies were prepared. This study searched the protein-coding gene of sperm-egg through the Next Generation Sequencing (NGS) and edited genes through the CRISPR/Cas9 system to induce infertile individuals that produced reproductive cells but could not form fertilized eggs. Through such a series of processes, it successfully established a composition development process for largemouth bass. It is judged that this study contributed to securing the valuable basic data for follow-up studies to verify its effect for the management of ecological disturbances without affecting the habitat of other endemic species in the same water system with the largemouth bass.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.177-183
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• 2021

Distribution aspects and extinction threat evaluation of the endangered species, Rhynchocypris semotilus were investigated in Goseong-gun, Gangwon-do, Korea, June 2020. Among the 12 sampling sites investigated during the study period, samples of R. semotilus were collected 268 individuals at 6 sites. The streams inhabited of R. semotilus were Songhyeoncheon (3 stations), Gojindong (2 stations) and Osodong (1 station). The main habitats of R. semotilus were uppermost and upper stream (Aa type) with 3~15 m water flow width, 0.3~1.3 m depth and high ratio boulder and cobble bottoms. The estimated age of the R. semotilus (June) based on their total length distribution indicated that 0-, 1-, 2-, 3- and more than 4-year-old were 6~27 mm, 38~59 mm, 60~75 mm, 78~93 mm and 96~125 mm, respectively, and their has matured reproductive organs over two years old. R. semotilus investigation results of the threat of extinction showed no tendency to decrease in population size, but estimated to be less than 1,000 mature individuals, with a small range of extend of occurrence (39.668 km²), area of occupancy (16 km²), and number of disconnected locations (3 locations). Therefore, R. semotilus is now considered vulnerable (VU D2) based on the IUCN Red List categories and criteria.