• Title/Summary/Keyword: Basic Reproduction Number

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The needs for sex knowledge in the late schooler (후기 학령기 아동의 성지식 요구)

  • Lee Eun Joo
    • Child Health Nursing Research
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    • v.6 no.2
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    • pp.167-185
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    • 2000
  • The goal of this research was to provide the basic data of sexual education for late schooler by finding out what they want to know about sex, or to see, if any, its relevancy between female and male students and between each grade. The sample for this research was a total of 453 students in 4th, 5th and 6th grade from 12 different classes at two elementary schools which were located in C city and in B province. The children were requested to write down three points on what they want to know or to learn most about sex, and their answers were put through two analytical stages in order to classify and to examine. The followings are the conclusions from the data. 1. The female cluster took 44.2% out of the whole sample, and there were 151 students per each grade. The specific girl ratios for each grade were 42.4%, 50.3% and 39.7% respectively. 2. It was noted that a total of 1,195 questions were gathered from the students writings, 45% of the questions was raised by the female students. The 4th grade students raised 432questions (43.8% by the girl) while the 5th. and the 6th grade students raised 387 (53.2% by the girl) and 376 questions (42.3% by the girl) respectively. The average number of questions per students was 2.6 while the female students raised 2.8 questions which was more than the average 2.5 questions by male students. It was the 4th grade female student cluster, which raised the most question (3.0) while the 6th grade male students raised the least question (2.4) in average. 3. The questions raised by the children could be divided into seven categories of the knowledge need on sex. They were Reproduction (310 questions, 25.9%), Sexual Culture (230, 19.2%), Concept of sex (125, 18.0%), Changes of Puberty (172, 14.4%), Sexual Health (119, 10.0%), Anatomy and Physiology of Reproductive System (78, 6.5%) and Sexual Tendency and behavior (71, 5.9%). 4. 'Reproduction' was the most frequently raised questions not only by both sex groups but also by the 5th grade students. Both sexes in the 4th grade showed the highest interest in Sexual Culture while it was Changes in Puberty for the both sexes in the 6th grade. The knowledge need on sex of the children indicated what they understand sexuality. They apprehended sex as sex, gender and sexuality in an inclusive way. They showed a major interest in the biological sex and the sexual activities. It seems that the children managed to understand clearly the meaning of gender, furthermore, they even pointed out that the streotyped sex role, patrimonial system and the sexual discrimination were unreasonable. The students possessed not only the least but also the most negative understanding in regard of sexuality. Two suggestions were made from the above conclusions for the practical sex education as well as its research. 1. For the practice: The sex education for the elementary upper grade school student should be relevant with their cognitive characteristics, also it should be more specific on the reproductive organs of both sexes, the actual scenes of the pregnancy and child delivery procedures. The gender concept should be added to the biological sex education, which will lead them to understand the unreasonableness of today's male-superior phenomenon and correct them. It is also necessary to develop educational programs for this age group so as to help them to understand sex in the sense of sexuality as well. 2. For the research: It is not easy to draw out a through conclusion since this study was carried out as one-time data collection. Yet it is undeniably helpful for the sex education if we can understand what the children want to know about sex, how much they know about it by conducting deep-interview researches through a small number of sample.

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Reproduction of the Dyeing Technique Used for the Small Flower Pattern Clamp Resist Dyed Fine Tabby in Amitabha of 1302 (1302년 아미타불복장 소화문협힐견(小花紋��纈絹) 염색기법 재현)

  • Choi, jungim;Sim, Yeon-ok
    • Korean Journal of Heritage: History & Science
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    • v.52 no.2
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    • pp.254-267
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    • 2019
  • Clamp resist dyeing is a resist dyeing technique in which a fabric is sandwiched between two or more pieces of woodcarving and then a pattern is expressed by dyeing. Records from nine years of King Heungdeok's reign during the Unified Silla dynasty show that the use of the clamp resist dyeing technique was banned for different garments. This was only for garments of YOOKDUPUMNYEO (六頭品女) or OHDUPUMNYEO (五頭品女). Given this, it can be assumed that clamp resisted fabrics were widely used, and the technique had been established during the Unified Silla dynasty or before. However, only the term can be found in the records. Neither its definition nor how this technique was used is explained. Also, it is difficult to assume the types and features of clamp resist dyeing due to a lack of materials. A small number of relics from the Goryeo dynasty still remain, though. Craft techniques have developed through international exchanges and have changed according to respective nations' circumstances including politics, economics, society, and culture. Hence, this research analyzed documents and relics from China and Japan, two countries neighboring the Republic of Korea, and studied the different types and features of clamp resist dyeing techniques. Clamp resist dyeing techniques were divided into monochromatic or multichromatic according to the number of colors that represented patterns, rather than according to the respective nations' features. They were also classified into mono, bilateral symmetry, or vertical-bilateral symmetry according to the structure of the patterns. Through the study of examples of inherited or reproduced dyeing techniques in China and Japan, it was confirmed that different engraving techniques, including relief, openwork, intaglio fit for the feature of a pattern and the number of colors, were applied in order to vividly represent patterns on fabric. Using small flower pattern clamp resist dyed fine tabby in Amitabha of 1302, the only relic showing its patterns and colors in Korea, as the experiment subject, this research successfully reproduced a clamp resist dyeing technique through a successful experiment based on the basic materials from the dyeing technique case study. Due to the significance of the experiment on a clamp resist dyeing technique that stopped its transmission and shows the features of the technique, this study is expected to be a basic resource that can be used for future reproductions of multichromatic clamp resist dyeing techniques. Also, it is expected to be helpful in widening and recreating the world of Korean pattern dyeing with modern dyeing techniques.

Seasonal Changes in the Basic Reproductive Physiology of the Endangered Reeves' Turtle (Mauremys reevesii) Based on Hibernation or Nonhibernation (멸종위기 종인 남생이(Mauremys reevesii)의 동면 여부에 따른 기초 번식생리의 계절적 변동)

  • Jung, Yu-Jeong;Kim, Il-Hun;Koo, Kyo-Soung;Song, Jae-Young;Kang, Shin-Geun;Park, Daesik
    • Korean Journal of Environment and Ecology
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    • v.30 no.6
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    • pp.977-985
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    • 2016
  • The captive breeding program of the Reeve's turtle (Mauremys reevesii), which is designated as an endangered category II species by the Korean Ministry of Environment, has developed, but the reproductive physiology of the species is still not fully understood. In this study, we investigated seasonal changes in the sex steroid levels, the number and size of follicles and eggs and male-female interactive behaviors of hibernated and non-hibernated turtles between November 2014 and October 2015. Plasma estradiol level in females increased from July and peaked in the period from August to October. Plasma testosterone level in males peaked between August and September and was the lowest in March, although there were some variations depending on the patterns of hibernation. Hibernated females had fully developed eggs between early May and middle July and laid eggs between early June and late July, but non-hibernated females had eggs between early April and early June and also between middle August and late November, and laid eggs in early June, mid-October, and early February. These results suggest that hibernation could be essential for normal follicular and egg developments. Male-female interactive behaviors including courtship intensified from late August and peaked in October and November. Our findings suggest that mating period of this species is directly related to increased steroid hormone levels, but follicular and egg developments in females are not. Our results could be very useful to the successful operation of captive rearing programs of the endangered Reeve' sturtles.

Effects of Manganese Exposure on the Testis Function and Serum Prolactin Concentration in Rat (망간 노출이 흰쥐의 정소기능과 혈청 프로락틴 농도에 미치는 영향)

  • Lee, Chae-Kwan
    • Development and Reproduction
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    • v.13 no.4
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    • pp.321-327
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    • 2009
  • This study aimed to examine the testis toxicities of metal compound, manganese (Mn), which may be generated as mist or fume in the industrial sites. As well as serum prolactin (PRL) concentration was analyzed because Mn accumulation in basal ganglia up-regulates serum PRL and hyperprolactinemia consecutively induces the testis toxicity. Male F344 rats were divided into the 4 groups (2 controls and 2 Mn treated groups, n=10) on the basis of the test condition (inhalation, Mn $1.5mg/m^3$ or not) and treatment period (for 4-weeks and 13-weeks). The treatment time was 6 hr. a day, 5 days a week for the whole body. Basic tests including changes in body weight, feed rate were observed. Blood and testis Mn concentration, and testis toxicity test such as the number and deformity test of sperm were also observed. Serum PRL level was analyzed by ELISA to certify the relationship between the Mn induced increase of the serum PRL level and sperm production. Blood and testis Mn concentrations were significantly and dose-dependently increased. Sperm count was decreased in Mn-treatment groups than control in a treatment time dependent manner. Morphological analysis of cauda epidydimal sperm showed that the frequencies of morphologically abnormal sperms such as bent tail and small head were increased in the both Mn-treatment groups than control. A significant increase in serum PRL levels was found in response to Mn treatment but it was not hyperprolactinemia range. These results suggest that treatment of Mn up-regulates the serum PRL concentration and induces the testis toxicity. The No Aversed Effect Level (NOAEL) of inhaled Mn on the male rat testis may be under the $1.5mg/m^3$.

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Effects of Temperature on the Development and Reproduction of Ostrinia scapulalis (Lepidoptera: Crambidae) (콩줄기명나방(Ostrinia scapulalis) (나비목: 포충나방과)의 발육과 산란에 미치는 온도의 영향)

  • Jeong Joon, Ahn;Eun Young, Kim;Bo Yoon, Seo;Jin Kyo, Jung
    • Korean journal of applied entomology
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    • v.61 no.4
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    • pp.577-590
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    • 2022
  • Ostrinia scapulalis is one of important pests in leguminous crops, especially red bean. In order to understand the biological characteristics of the insect, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of O. scapulalis at eleven constant temperatures of 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, and 36℃. Eggs and larvae successfully developed next life stage at most temperature subjected except 7, 10 and 13℃. The developmental period of egg, larva and pupa decreased as temperature increased. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of O. scapulalis were estimated by linear regression as 13.5℃ and 384.5DD, respectively. TL and TH from egg hatching to adult emergence using SSI model were 19.4℃ and 39.8℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of O. scapulalis was 20.4℃. Adults produced viable eggs at the temperature range between 16℃ and 34℃, and showed a maximum number, ca. 416 offsprings, at 25℃. Adult models including aging rate, age-specific survival rate, age-specific cumulative oviposition, and temperature-dependent fecundity were constructed, using the temperature-dependent adult traits. Temperature-dependent development models and adult oviposition models will be useful components to understand the population dynamics of O. scapulalis and will be expected using a basic data for establishing the strategy of integrated pest management in leguminous crops.

Neural and Cholinergic Differentiation of Mesenchymal Stem Cells Derived from the Human Umbilical Cord Blood (인간 제대혈액에서 유래된 중간엽 줄기세포의 신경 및 콜린성 분화)

  • Kam, Kyung-Yoon;Kang, Ji-Hye;Do, Byung-Rok;Kim, Hea-Kwon;Kang, Sung-Goo
    • Development and Reproduction
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    • v.11 no.3
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    • pp.235-243
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    • 2007
  • Human umbilical cord blood(HUCB) contains a rich source of hematopoietic stem cells, mesenchymal stem cells and endothelial cell precursors. Mesenchymal stem cells(MSCs) in HUCB are multipotent stem cells, differ from hematopoietic stem cells and can be differentiated into neural cells. We studied on transdifferentiation-promoting conditions in neural cells and cholinergic neuron induction of HUCB-derived MSCs. Neural differentiation was induced by addingdimethyl sulphoxide(DMSO) and butylated hydroxyanisole(BHA) in Dulbeco's Modified Essential Medium(DMEM) and fetal bovine serum(FBS). Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor(bFGF), retinoic acid(RA) and sonic hedgehog(Shh). MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including $\beta$-tubulin III, GFAP and MBP, was markedly elevated during this acute differentiation. The differentiation rate was about $32.3{\pm}2.9%$ for $\beta$-tubulin III-positive cells, $11.0{\pm}0.9%$ for GFAP, and $9.4{\pm}1.0%$ for Gal-C. HUCB-MSCs treated combinatorially with bFGF, RA and Shh were differentiated into cholinergic neurons. After cholinergic neuronal differentiation, the $\beta$-tubulin III-positive cell population of total cells was $31.3{\pm}3.2%$ and of differentiated neuronal population, $70.0{\pm}7.8%$ was ChAT-positive showing 3 folds higher in cholinergic population than neural induction. Conclusively, HUCB-derived MSCs can be differentiated into neural and cholinergic neurons and these findings suggest that HUCB are alternative cell source of treatment for neurodegenerative diseases such as Alzheimer's disease.

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Differentiation of Dopaminergic and Cholinergic Neurons from Mesenchymal-like Stem Cells Derived from the Adipose Tissue (사람 지방 유래 중간엽 줄기세포의 도파민성 및 콜린성 신경세포분화)

  • Hong, In-Kyung;Jeong, Na-Hee;Kim, Ju-Ran;Do, Byung-Rok;Kim, Hea-Kwon;Kang, Sung-Goo
    • Development and Reproduction
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    • v.12 no.1
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    • pp.31-39
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    • 2008
  • Neural tissue has limited intrinsic capacity of repair after injury, and the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesechymal-like stem cells from human adipose tissues (AT-MSCs), and studied on transdifferentiation-promoting conditions in neural cells. Dopaminergic and cholinergic neuron induction of AT-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulphoxide (DMSO) and butylated hydroxyanisole(BHA) in N2 Medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. AT-MSCs treated with bFGF, SHH and FGF8 were differentiatied into dopaminergic neurons that were immunopositive for TH antibody. Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor (bFGF), retinoic acid (RA) and sonic hedgehog (Shh). AT-MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including neuro D1, $\beta$-tubulin III, GFAP and nestinwas markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after preinduction medium culture, we confirmed the differentiation of dopaminergic and cholinergic neurons by TH/$\beta$-tubulin III or ChAT/ $\beta$-tubulin III positive cells. Conclusively, AT-MSCs can be differentiated into dopaminergic and cholinergic neuronsand these findings suggest that AT-MSCs are alternative cell source of treatment for neurodegenerative diseases.

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Characteristics of Seed and Germination of Rhododendron mucronulatum by Collection Dates and Germination Temperatures (채취 시기와 발아 온도에 따른 진달래의 종자 및 발아 특성)

  • Choi, Kyu Seong;Song, Ki Seon;Koo, Da Eun;Lee, Ha Na;Sung, Hwan In;Kim, Jong Jin
    • Journal of Korean Society of Forest Science
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    • v.107 no.3
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    • pp.237-244
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    • 2018
  • This study was carried out in order to secure basic data of seedling mass propagation technique of Rhododendron mucronulatum which is the native tree species of Korea by surveying the characteristics of its fruit and seed. The fruits were collected at Mt. Goryeo in Ganghwa-gun on different dates in 2013; August 26th, September 5th, September 12th, October 4th. The seed germination test was carried out at 5, 10, 15, 20, 25 and $30^{\circ}C$. Moisture content of the fruit was highest (54.5%) in the fruit collected on September 5th. Number of the seeds in a fruit was 91.3 to 116.3, regardless of the collection date. Seed length was highest ($1947.4{\mu}m$) in the seeds collected on October 4th and seed width was highest ($727.3{\mu}m$) in the seeds collected on September 12th. Germination rate of the seeds was highest at $25^{\circ}C$ regardless of the seed collection date, which showed the highest value(27.3%) in the seeds collected September 12th. Meanwhile, the seeds were not germinated not at all at 5, 10 and $30^{\circ}C$. $T_{50}$ and mean germination time of the seeds got shorter at the higher temperature. Germination uniformity got lower when the collection date got later. Germination speed of the seeds was fastest at $25^{\circ}C$. According to the results of this study, it seems that the appropriate time to collect fruit and seed is between September 12th and October 4th, and the appropriate temperature for the seed germination is $25^{\circ}C$.