• Journal of the Korean Dietetic Association
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• v.12 no.3
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• pp.225-234
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• 2006

The purpose of this study was to identify the factors that related to obesity among 6th grade elementary school girls. The study subjects were 337 girls residing in Seoul. Not only variables of nutritional environment such as eating habits, health related behavioral variables, nutritional feeding methods during infancy, and genetic factors but also sexual maturity had been included as a obesity related factors. Association between obesity and related variables were analyzed by $x^2$(Chi-square) test. The obesity prevalence of the study subjects were 16% based on Röhrer Index(RI). Fifty-three percent of the study subjects experienced menarche at the time of data collection. Result of analysis showed that not only the nutritional enviromental variables such as eating habits, specific food preferences, and habit of exercise but also genetic factors did not show any statistically significant association with obesity. Above finding may imply that more variables other than the variables included in this study might have influenced on the obesity of the children. However sexual maturity in term of breast development showed significant association with obesity.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.65-76
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• 2013

We investigated the gametogenic cycle and spawning seasons of the male Chlamys (Azumapecten) farreri nipponensis by qualitative and quantitative analyses, and also the size at 50% of group sexual maturity was calculated by the data of first sexual maturity. In this study, the male gametogenic cycle of this species by qualitative analysis was divided into five successive stages: early active stage (January to March), late active stage (March to April), ripe stage (April to August), partially spawned stage (July to September), and spent/inactive stage (August to January). The male gametogenic cycle showed similar patterns with monthly changes in the gonadosomatic index and condition index. Particularly, spawning in male scallop occurred once a year from July to September, unlike the spawning period of this species (from June to August) reported by the previous researchers. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by spermatogenic stages to the testis areas in males showed a maximum in June, and then sharply dropped from July to September, 2006. From these data, it is apparent that the spawning season of C. (A.) farreri nipponensis occurred once per year from July to early September, indicating a unimodal gametogenic cycle during the year. Shell heights at 50% of group sexual maturity (RM50) fitted to an exponential equation were estimated to be 49.90 mm in males (considered to be one year old), and it was 100% for male scallops over 61.0 mm (considered to be two years old).

• Child Health Nursing Research
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• v.23 no.3
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• pp.329-339
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• 2017

Purpose: This study was conducted to identify the sexual maturation, parenting attitude, maturity fear and emotional and behavioral problems of girls in elementary school, and to examine the relation between these variables and factors that influence emotional and behavioral problems. Methods: Participants were 128 second, third and fourth year students from 3 elementary schools. Data were analyzed using t-test, ANOVA and $Scheff{\acute{e}}$ test, Pearson correlation coefficients, and stepwise multiple regression with SPSS/WIN 21.0. Results: Emotional and behavioral problems were related to eating rate, eating breakfast, frequency of late-night snacks and main communicator on pubertal development. Emotional and behavioral problems showed a positive correlation with maturity fear and father's parenting attitude (strictness) and a negative correlation with parenting attitude and father's parenting attitude (intimacy). Maturity fear, father's parenting attitude, eating breakfast, and main communicator on pubertal development had significant influence on emotional and behavioral problems of girls in elementary school. Conclusion: Findings show that for effective management of emotional and behavioral problems in elementary school girls, programs including coping with maturity fear, supportive parenting of father, diet education, and functional communication with mother on pubertal development should be developed.

• Child Health Nursing Research
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• v.22 no.2
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• pp.137-144
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• 2016

Purpose: The purpose of this study was to investigate factors that influence maturity fears in elementary school girls. Methods: The participants were 118 3rd and 4th grade students from 3 elementary schools in 3 cities in Korea. Data were collected using questionnaires which included measurement scales for the relative variables and demographic data. Data were analyzed using t-test, ANOVA, Pearson correlation coefficients, and hierarchial regression analysis with SPSS/WIN 21.0. Results: The significant predictors of maturity fears were weight, father-child communication, frequency of maturity communication with father, and close relation with mother. Conclusion: For effective management of maturity fears in elementary school girls, programs including weight control, functional communication with father and supportive nurturance of mother should be developed.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.97-104
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• 2008

The gonad index, reproductive cycle and first sexual maturity of Sinonovacula constricta collected from Simpo, Kimje-gun, Korea were investigated by histological analysis. The gonad index(GI) in both sexes of S. constricta increased from April and reached a maximum in July when the water temperature rapidly increased. And then, the GI values gradually decreased by spawning from August through October. Monthly variations in the GI showed a close relationship with ovarian development. The reproductive cycle in females and males can be classified into five successive stages: early active stage(March to June), late active stage(May to July), ripe stage(July to September), partially spawned stage(August to October), spent/inactive stage(October to March). The percentage of first sexual maturations in female and male clams of 50.1-60.0 mm in shell length was over 50%, and for clams over 70.1 mm in shell length, it was 100%. Because harvesting clams < 50.1 mm in shell length could potentially cause a drastic reduction in recruitment, a measure including a prohibitory fishing size should be taken for adequate improved fisheries resource management.

• Journal of Korean Home Economics Education Association
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• v.23 no.3
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• pp.185-200
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• 2011

The purpose of this study was to investigate if these factors affect the correlation between the female adolescent interest in appearance and appearance management behavior with self-concept and sexual maturity. To achieve this, a survey was conducted for the female students in elementary and middle school in the Seoul area. The results of this study were as follows. 1. The comparison of students' interest in appearance and appearance management behavior showed that the middle school students showed higher scores in both matters. 2. Elementary students generally held more positive self-concept, with domestic self value shown statistically high 3. Tanner Stage 2.3. the early puberty stage, for elementary school students, and Tanner Stage 3.4. the growth and development stage, for middle school students. The percentage of students who had already entered menstruating turned out to be only 33% for elementary students but 90% for middle school students. Their subjective views of sexual maturity were also different as elementary students had negative feeling when they thought their sexual maturity were maturity were earlier than their peers' while middle school students were just the opposite. 4. The study on the impact of self-concept and sexual maturity on the interest in appearance of female students in elementary and middle school showed that elementary students had a higher interest in appearance that corresponded to the lower domestic self-concept and a higher social self-concept. On the other hand, middle school students showed higher interest in appearance, corresponding to their higher social self-concept, lower domestic self-concept, more negative feeling of sexual maturity, and higher feeling of physical self-concept. The study on the impact of interest in appearance, self-concept, and sexual maturity on the appearance management behavior of elementary and middle school female students revealed that elementary students with a higher interest in appearance were more enthusiastic about appearance management. Middle school students' appearance management behavior turned out to be higher, corresponding to their higher interest in appearance, lower domestic self-concept, and higher social self-concept.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.2
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• pp.19-35
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• 2008

Objectives : As obese children have been increased, the interest in the impact of obesity on growth also have been increased. This study is to examine relations between obesity and skeletal maturity by analyzing body compositions and bone age. Methods : Subjects were composed of 233 children from 6 years to 17 years of age, without any other diseases related to growth, who visited the department of pediatrics, OO oriental medicine hospital and measured their body composition (body mass index, body fat ratio, fitness score) and bone age. Results : 1. As body mass index was increased, the skeletal maturity significantly was also increased. 2. As the mean of bone maturity was increased, the BMI was increased from the underweight type to the normal type to the overweight type; the bone maturity was increased as the fat ratio was increased from the normal type to the obese type to the excessively obese type; and the bone maturity was higher in the weak, obese type than the normal type when classified according to the Fitness Score. 3. The bone maturity of the overweight group in the BMI classification and excessively obese group in the fat ratio classification significantly were increased. 4. Skeletal maturity significantly was increased in children who developed secondary sexual character. 5. The significance of obesity causing increase of the skeletal maturity was higher in boys than in girls. 6. Only in the case of children without development of secondary sexual character, obesity caused an significant increases in the skeletal maturity. Conclusions : Obesity could cause the increase of skeletal maturity, and the obesity could affect more to the boys than girls and more to the children than teenagers.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.449-458
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• 2013

This study investigated purplish Washington clam, Saxidomus purpuratus on its gonadal development, reproductive cycle and shell length (age) at 50% female group maturity from January to December 2011 in Jinhae Bay, Korea. This species is dioecious. The gonad index (GI) began to increase in January, reached the maximum value in May and to decrease in June, reached the minimum value in September then to increase slowly in October again. The reproductive cycle of the clams can be divided into five successive stages: the early active stage (Ea, from February to March), the late active stage (La, from January to March and October to December), the ripe stage (R, from January to May), the spawning stage (S, from June to December) and the degenerative and inactive stage (Ia, from January to February and November to December). The spawning periods were from June to December and the main spawning periods were from July to October. The shell length at 50% female group maturity (SL50) was estimated to be 63.6 mm, which can be converted as sexual maturity age of 2.2 year.

• The Journal of Pediatrics of Korean Medicine
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• v.24 no.2
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• pp.147-158
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• 2010

Objectives The study was designed to find out the relationships between low weight and growth, skeletal maturity among children by analyzing body composition and bone age. Methods Subjects were composed of 336 children from six years to seventeen years of age, without any other diseases related to growth, who visited the department of oriental pediatrics East West Neo Medical Center at Kyung Hee University and were measured their body composition and bone age. Results There were significant correlations between decreasing of RH-MPH(%) and low weight. 1. As obesity index decreased, the RH-MPH was also decreased. 2. The RH-MPH(%) of the low weight group according to the obesity index classification was significantly decreased than that of the normal weight group. 3. The skeletal maturity was more decreased in the low weight group. However, the differences between the two group was not significant. 4. The RH-MPH(%) was increased in children who developed secondary sexual character. Skeletal maturity was decreased in children who developed secondary sexual character. 5. The RH-MPH(%), and skeletal maturity was not significantly different between males and females. 6. Only in the case of children without development of secondary sexual character, low weight caused significant RH-MPH(%) decrease. Conclusions Low weight children might be smaller than what it supposed to be. Also, low weight could affect body development more to the children than to the teenager.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.455-459
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• 1996

The genetic parameters for various economic traits were estimated in a White Leghorn population selected for part period egg production over 16 generations. In early part of selection, egg number had moderate to high heritability (0.26 to 0.51) while age at sexual maturity, egg weight and body weight at 20 and 40 weeks of age had high heritability (0.54 to 0.83). The sire component heritability for all the traits except 20 week body weight declined in later periods of selection. Sex linked gene effects for egg number and age at sexual maturity were more important in early periods of selection in comparison to the later periods, while maternal effects remained important for 20 week body weight in all the periods. Egg number was negatively correlated with egg weight ($r_{G(S)}=-0.36$), age at sexual maturity ($r_{G(S)}=-0.84$) and 40 week body weight ($r_{G(S)}=-0.84$), while it was positively correlated with 20 week body weight ($r_{G(S)}=-0.34$) in base generation. The genetic association between egg number and 40 week body weight changed not only in magnitude but also in direction in later periods. The genetic correlation of egg number with egg weight as well as with age at sexual maturity also decreased in magnitude in later periods of selection.