• Animal cells and systems
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• v.6 no.1
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• pp.75-80
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• 2002

A study on the effects of bisphenol A (BPA) on sex differentiation and gonadal development in medaka, Oryzias latipes, was investigated by histological examination. The fish were exposed to aqueous solutions of BPA at nominal concentrations of 50, 100, and 200 $\mu\textrm{g}$/L from newly-hatched larvae stage to 70 d. The ovaries of female fish were composed of oocytes at the chromatin nucleolus and peri-nucleolus stages at 20 d after the exposure. The testes contained a number of spermatogonia and spermatocytes at 30 d. In the process of sex differentiation. gonadal development was not different in all experimental groups until 30 d after the exposure. At 70 d after the exposure, however, advanced development of oocytes in the ovary and inhibition of spermatogenesis in the testis were observed in the BPA-treated groups compared to the non-treated controls. More females than males were identified in the 50 and 100 $\mu\textrm{g}$/L BPA-treated groups, in comparison to the 200 $\mu\textrm{g}$/L BPA-treated group and non-treated controls. Medaka exposed to 200 $\mu\textrm{g}$/L BPA were bigger compared to other experimental groups. The present study suggests that BPA may lead to problems in either mating or sexual behavior due to the difference in growth and disparity of sexual maturation between male and female fish.

• Journal of Aquaculture
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• v.20 no.4
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• pp.212-218
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• 2007

Reproductive biology (sexual maturity and reproductive cycle) of starry flounder Platichthys stellatus were examined by histological methods. From March 2004 to February 2005, 144 females and males were sampled. Gonadosomatic index (GSI) of female and male were peaked in May and February, respectively. Monthly changes of hepatosomotic index (HSI) showed a negative correlationwith those of the GSI. Changes of condition factor (CF) in female were correlated with gonad maturation, while that of male were no difference all the year round. Based on monthly GSI and gonadal development the reproductive cycle of starry flounder could be divided into four stages: growing stage (September to November), maturation stage (September to February), ripe and spent stage (March to May), and recovery and resting stage (June to August). Biological minimum size of female was 1,074 g. The relationship between fecundity (F) and body weight (BW) of the fish was expressed as $F\;=\;455.86BW^{1.2006}$.

• Journal of the Korean Home Economics Association
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• v.42 no.5
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• pp.53-76
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• 2004

This study conducted a survey on sexuality for the purpose of substantial verification, focusing on literature reviews of premarital sexuality. The Literature reviews included relevant studies of our society and its cultures such as premarital sexuality and behaviors, expressions of love or intimacy, contraception, abortion, sex education and sexuality in family contexts. The survey was conducted to 355 university students and 200 working premarital adults in Seoul, Gyeonggi and Gangwon areas. It has 21 questions to measure sexuality by sexual altitude sentence completion Scale (composed of 4 categories and options of the other items)which has been widely used by professional counsel institutes. Male and female students complete the sentence of this scale, then similar contents were classified. Love type test was developed by Hendrick & Hendrick (1986) was used to measure love and intimacy. Results from the sentence completion for sexuality attitudes are generally as follows: First of all, there was clear difference in male md female responses about each categories. For example, With regard to the questions on premarital sex with opposite sex friends of long time relationship, more than half of male students said it is all right, whereas more than half of female students answered to the same questions that it can never be possible, with many answering 'I don't know', or leaving them unanswered. The survey result, masturbation answered that Female is needed however many Females actually don't it. But Male is almost necessary and conduct himself. On questions regarding, Homosexuality is both male and Female answered opposed. These results of the study show that premarital adults clearly open to issues on sexuality compared with the past, but they have not established their own sexual identity, which can be seen with big gap between male and female perspectives, due to experiencing confusion under the changing environment of the society.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.256-264
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• 2017

Background: The aim of this study was to clarify the relationship between the sexual reproduction and the resource allocation in a natural Polygonatum humile population grown in a temperate mixed forest gap. For this aim, the plant size, the node which flower was formed, the fruiting rate, and the dry weight of each organ were monitored from June 2014 to August 2015. Results: Firstly, in 3-13-leaf plants, plants with leaves ${\leq}8$ did not have flowers and in plants with over 9 leaves the flowering rate increased with the number of leaves. Among plants with the same number of leaves, the total leaf area and dry weight of flowering plants were larger than those of non-flowering plants. The minimum leaf area and dry weight of flowering plants were $100cm^2$ and 200 mg, respectively. Secondary, the flowers were formed at the 3rd~8th nodes, and the flowering rate was highest at the 5th node. Thirdly, cumulative values of leaf properties from the last leaf (the top leaf on a stem) to the same leaf rank were greater in a plant with a reproductive organ than in a plant without a reproductive organ. Fourthly, fruit set was 6.1% and faithful fruit was 2.6% of total flowers. Biomasses of new rhizomes produced per milligram dry weight of leaf were $0.397{\pm}190mg$ in plants that set fruit and $0.520{\pm}0.263mg$ in plants that did not, and the difference between the 2 plant groups was significant at the 0.1% level. Conclusions: P. humile showed that the 1st flower formed on the 3rd node from the shoot's base. And P. humile showed the minimum plant size needed in fruiting, and fruiting restricted the growth of new rhizomes. However, the fruiting rate was very low. Thus, it was thought that the low fruiting rate caused more energy to invest in the rhizomes, leading to a longer rhizome. A longer rhizome was thought to be more advantageous than a short one to avoid the shading.

• Journal of Korean Home Economics Education Association
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• v.21 no.4
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• pp.127-144
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• 2009

The purpose of this study was to develop and to examine the effect on sex education program to middle school student. The subjects were 8 grade students and to examine 10 session education. Collected data was analyzed by SPSS WIN 12.0 program. The major results of this study were as follow ; First sex education program was developed into four areas : human and sex psychology, physical development and sex healthy, sex social environment and equality, marriage and healthy family. Included program contents were human dignit communication, sex curiosity, difference of sex, genital organs, pregnancy and birth, family violence, sexual violence, equality, parent-children relationships, family role. Second, sex education program was effective to improve degree of sex knowledge and to change sex attitude. Finally, sex education program needs to be continuously offered even to lower grades in elementary school.

• Korean Journal of Health Education and Promotion
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• v.22 no.3
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• pp.65-81
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• 2005

Objectives: This study was conducted to describe child perceived health knowledge, health education needs, and health behaviors by sex as a representative general characteristic and examined their associations for students' better health behavior changes. Methods: The survey participants were 410 fourth to sixth grade students in two elementary schools in Seoul, Korea. A total of 12 classes in two elementary schools were randomly selected and all students of the selected classes participated in the self-administered survey. The questionnaire contained the items of perceived health knowledge, health education needs (health topics which they want to know more), health behavior, and general characteristics. Results: Perceived health knowledge, health education needs, and health behaviors were, generally, better among girls than boys. Sexual differences were not large in perceived health knowledge, health education needs, health behaviors. Perceived health knowledge had significant positive correlation with health behaviors both in boys and girls(p <.01). The correlation between perceived health knowledge and health behaviors(r =.36) was two fold greater than correlation between health education needs and health behaviors(r =.18) among boys; where as the two correlations were similar to each other among girls. The significant factors were perceived health knowledge, sex, grade, and health education needs in order, and the four factors described health behaviors in 21.0%. The higher perceived health knowledge, girls, lower grade, and more health education needs was associated with the better health behaviors. Conclusions: There was significant sexual difference of the relationship between health knowledge, health education needs, and health behaviors among children. Perceived health knowledge was more important factor to improve health behaviors among boys while perceived health knowledge and health education needs had equal importance on health behaviors among girls. Therefore, knowledge building should be an essential part of health education class goals for building better health behaviors.

• Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.12-19
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• 2022

In the present study, we investigated the effects of recombinant eel gonadotropins (rec-GTHs) on maturation induction in immature ovarian culture in vitro and sex steroid hormones in vivo in the Japanese eel Anguilla japonica. To study the in vitro effects of rec-GTHs on estradiol-17β (E2) production in immature ovarian tissues, ovarian tissues were incubated with different doses of rec-follicle-stimulating hormone (rec-FSH) or rec-luteinizing hormone (rec-LH). The results revealed that the E2 levels in the rec-FSH (0.1, 0.5, or 1 ㎍/mL)- and rec-LH (0.1 or 0.5 ㎍/mL)-treated groups were significantly higher than those in the female eels from the control group. Furthermore, to investigate the in vivo effects of rec-GTHs on the gonadosomatic index (GSI) and plasma sex steroid hormone levels, the eels were injected intraperitoneally with eel's ringer (control), salmon pituitary extract (SPE; for female eels), human chorionic gonadotropin (hCG; for male eels), rec-FSH, rec-LH, and rec-FSH + rec-LH once a week. The results revealed that except for the SPE and the hCG groups, none of the groups exhibited a significant difference in GSI values. However, in vivo plasma E2 levels increased at the end of 4 weeks after rec-FSH treatment in female eels. Based on these results, it is suggested that rec-GTHs may have a positive effect on sexual maturation in female eels; however, further studies on complementary rec-protein production systems and additional glycosylation of rec-hormones are needed to elucidate hormone bioactivity in vivo and in vitro.

• Physical Therapy Korea
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• v.12 no.4
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• pp.48-57
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• 2005

The purpose of this study was to evaluate the general characteristics, complications and level of social adaptation of spinal cord injured patients. The subjects were one hundred forty five members who were inpatients or outpatients from October 1, 2004 to April 30, 2005 in general hospitals and municipal welfare centers for the handicapped located in the metropolitan city of Gwangju. The following results were obtained using Modified Barthel Index (MBI). 1) Gender distribution was 77.9% male and 22.1% female. The mean age at the time of injury was 35.4 and the mean age during the study was 44.2. 2) The degree of paralysis among the subjects was as follows: 49.0% had complete paralysis and 51.0% suffered incomplete paralysis. The most frequently injured lesion among the subjects was cervical (49.0%), followed by thoracic (35.9%), and lumbar (15.2%). 3) The mean MBI score was 63.5. There was statistically significant difference in the MBI score in the relation between complete and incomplete paralysis, the relation between cervical, thoracic, and lumbar injury, and the relation between a recovery period of less than three years and more than three years according to the characteristics of injury (p<.05). 4) There was statistically significant difference in the MBI score of subjects who had complications concerning spasticity, deformity, urinary tract infection, and sexual dysfunction (p<.05). 5) The most serious emotional pain after spinal cord injury resulted from economic issues, which affected 35.2% of the subjects. The group having a shorter recovery period after spinal cord injury complained of psychological matters, the group having a longer recovery period complained about the surrounding environment (lack of convenient facilities), suggesting statistically significant difference (p<.05). 6) The most common activities of the group with injuries more than ten years old included meeting schoolmates and working, while most common activities of the group with injuries less than three years old included attending religious functions and miscellaneous others (watching TV, spending time with family), suggesting statistically significant difference (p<.05).

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.179-189
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• 2000

The purpose of this research is to complement the existing researches on landfill bottom liners behavior during the periods of freeze and thaw. Landfill-related researches have been typically focused on small-scale soil samples that are often compacted under conditions different from those used in the field. Although these tests have been invaluable in clarifying the problem of freeze and thaw, extending the results of such experimental studies to prototype landfills are questionable. In this investigation, the author utilized a large scale laboratory simulation allowing inclusion of the field depth of the cover systems, layered soil profiles, rainfall simulation, a cold climate and boundary conditions similar to those encountered in the landfill. The soil materials were stabilized soils (mixed clays, cements, and minerals) instead of clays. The bottom liners are made up of drainage layer (30 cm), stabilized layer (75 cm), and leach collection layer (60 cm). The stabilized layers are made up of supporting layer (45 cm) and low permeable layer (30 cm) - consisting of $P_A\; and\; P_B$ layer. As a results, depths of penetration increased by about 2~5 more centimeters at rainfall simulated designs than those at no rainfall simulated designs (that is design 3, design 5 and design 7) - it increased by about 20mm/day in the bottom liners and frost heaves also increased it by a few millimeters. Also, a few cracks appeared partly. According to these results, we can surmise that the compacted stabilized soil is more reliable than the compacted clay liners for construction of the landfill liners.

• Journal of Families and Better Life
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• v.19 no.1
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• pp.1-16
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• 2001

This study examined the level of experienced problem and related variables of farming women as a part of study on problem diagnosis and status enhancement of rural women. The subjects were 980 married farming women living in rural area. Data were analyzed by frequencies, percentages, mean, standard deviation, factor analysis, t-test, ANOVA, Duncan-test, and multiple regression. The major findings were as follows : 1) Rural women experienced five categorized problems(farming work & health problem, institution & facilities problem, personality differences & communication problem with husband, child & in-law relatives problem, and husbands violence & sexual problem. 2) The significant variables that influenced on experienced problems were conflict coping behaviors, husbands housework participation, farming work time, age, the level of health, and income etc. Additionally socio-demographic factors, their vocational consciousness, housework sharing, and couples difference of sex-role attitude as related variables of the level of experienced problem of farming women were exmained and discussed the implication.