• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.257-265
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• 2000

Harderian glands are the unique organs in several mammals, which human and non-human primates do not have. We report the ultrastructural changes in the postnatal developmental periods of Harderian glands in Mongolian gerbil(Meriones unguiculatus). Male and female Mongolian gerbils were sacrificed on days 3, 10, 30 and 60 after birth and their Harderian glands were observed by transmission electron microscope. The obtained results were summarized as follows; 1. In 3-day-old Mongolian gerbils, Harderian gland was composed of one excretory duct and immature tubules which have two type cells, dark and light cells, identified electron-dense and electron-lucent respectively. 2. In 10-day-old Mongolian gerbils, small lipid vacuoles began to be found in the cytoplasm of the secretory cells of the Harderian gland. Mitochondria, Golgi apparatus, polysomes and slash were more abundant in the cytoplasm of dark cells than those of light cells. The arrangement of tubules in the gland was much more condensed than that of 3-day-old Mongolian gerbils. 3. In 30-day-old Mongolian gerbils, the secretory cells of the tubule were typically columnar in shape and there was one type cell in the tubule. Most of the columnar secretory cells contained various size vacuoles. 4. In 60-day-old Mongolian gerbils, the Harderian gland possessed the typical structural characteristics of adults. The mature glandular structures were more significant than those of 30-day-old animals.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.15-19
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• 2004

The expression of a chimeric transgene (nos-npt II) has been examined in 9 years old transgenic poplars (Populus koreana x P. nigra) growing in a nursery. The expression of the gene in twenty six independentely transformed plants were examined by 1) enzyme (NPT II) assay, 2) RT-PCR, and 3) resistance to kanamycin. High NPT II activities in young leaves of all the transformed plants were found even without a selection pressure for antibiotics for 9 years. However, the activity varied with the positions of leaves in the stem in that young leaves showed higher activity than did mature tissues. When leaf segments were cultured in the presence of 150 mg/l kanamycin, only those from young leaves produced vigorously growing callus. However, as in the case of NPTII assay, the leaf segments from mature leaves did not form callus well on the media. RT-PCR with nptII specific primers also showed that amplification products were observed only when RNAs from young tissues were used. The total RNA gel showed that while RNA in young leaves are relatively stable and in a large quantity, those in old leaves were mostly degraded. All the above results suggest that the gene is transcriptionally active only in young tissue even though it is attached to a constituitive promoter. Therefore, the expression of foreign gene in poplar plants seemed to be affected by the metabolic state of the cells and thus vary greatly with the developmental stages and the age of tissue.

• Korean Journal of Child Studies
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• v.12 no.1
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• pp.78-90
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• 1991

This study investigated the relation between oral counting and numerical abilities of young children. The subjects were 33 four-year-old children and 47 five-year-old children from 2 preschools and 2 kindergartens in Kwangju. The test was individually administered in an empty classroom or a hallway by using counting buttons and number cards. The data were analyzed by t-test, Pearsons correlation and multiple regression analysis. The results indicated that (1) older children did better than younger children in oral counting. (2) but the older children did not do better than the younger children in the numerical abilities, (3) the numerical abilities of young children differed according to the degree of oral counting, and (4) the oral counting of young children was one significant predictor of numerical abilities. Findings support the inclusion of activities for oral counting in kindergartens.

• Journal of the Korean Home Economics Association
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• v.45 no.7
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• pp.49-60
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• 2007

The purpose of this study was to analyze the weight measurement tasks according to children's ages and whether 4-to 6-year-old children use proper measurement equipment to measure weight. The study subjects were 105 preschool children: 37,38, and 30 4-, 5-, and 6-year-old children, respectively. The results showed that young children use 3 to 4 strategies. They used a strategy to estimate objects visually on the first step in measurement by direct comparison. On the second step, in measurement by nonstandard unit, they held up objects with one hand or two hands. That is, two strategies were shown in measuring objects with hands in this second step. On the third step, which is measured by standard unit, they used a strategy to choose the equal arm balance out of suggested measurement equipment.

• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.1037-1046
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• 2004

Age-dependent changes in body fat can often be observed in normal population. A series of indirect body fat estimates, such as hydrodensitometry, Bioelectrical Impedance Analysis(BIA), and anthropometry equation for body fat, have been developed. The BIA made it possible to analyze body fat mass more related to hydrodensitometry than anthropometry. This study is to compare the body composition analysis between bioelectrical impedance analysis(BIA) and anthropometric measurements of women. The subjects were a group of Daejeon residents including 32 young-aged women($21.50{\pm}1.44$), 30 middle-aged women($50.33{\pm}5.27$), and 40 old-aged women($69.22{\pm}5.74$). We used BIA(inbody 3.0, Biospace Korea) to determine body fat and other body composition. We also measured weight, height, circumference for 12 parts, and skinfold thickness for 9 parts of all subjects' body. The results are as follows: The subjects' height by the age group were $161.74{\pm}0.94cm$ in the young-aged women, $154.16{\pm}1.09cm$ in the middle-aged, and $148.60{\pm}0.78cm$ in the old-aged respectively. BMI were, in order, $21.68{\pm}0.49,\;22.87{\pm}0.89,\;and\;23.85{\pm}0.55$. Relative body fat determined by BIA was, also in order, $29.06{\pm}0.92%,\;26.35{\pm}1.02%,and\;29.35{\pm}1.07%$. Circumference and skinfold that showed the highest correlation with body fat by BIA was waist in the young-aged(r=0.738) and bast in the middle- and old-aged(r=0.844, r=0.804), and triceps in the young-and old-aged(r=0.538, r=0.798), and subcostal in the middle-aged(r=0.872). Body fat Estimations by BIA were the highest correlation with Caucasian women's equation(r=0.588) in young-aged women, Siri's equation with Durnin & Womesley's body density measurement(r=0.875) in middle aged women and Caucasian women' equation(r=0.872) in old aged women. We need to develop specific anthropometric equations based on sex and age to determine body fat.

• Journal of Soil and Groundwater Environment
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• v.20 no.5
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• pp.34-40
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• 2015

It is reported that the intensity of rainfall will likely increase, on average, over the world on 2000. For water resources security, many studies for flow paths from rainfall or snowmelt to subsurface have been conducted. In Korea, few isotopic studies for characterizations of flow path have been undertaken. For a better understanding of how water derived from atmosphere moves to subsurface and from subsurface to stream, an analysis of precipitation and stream water using oxygen-18 and deuterium isotopes in a small watershed, Dorim-cheon, Seoul, was conducted with high resolution data. Variations of oxygen-18 in precipitation greater than 10‰ (δ¹⁸O_max = −1.21‰, δ¹⁸O_min = −11.23) were observed. Isotopic compositions of old water (groundwater) assumed as the stream water collected in advance were −8.98‰ and −61.85‰ for oxygen and hydrogen, respectively. Using a two-component mixing model, hydrograph separation of the stream water in Dorim-cheon was conducted based on weighted mean value of δ¹⁸O. As a result, except of instant dominance of rainfall, contribution of old water was dominant during the study period. On average, 71.3% of the old water and 28.7% of rainfall contributed to the stream water. The results show that even in the small watershed, which is covered with thin soil layer in granite mountain region, the stream water is considerably influenced by old water inflow rather than rainfall.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.659-667
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• 2009

The primary object of this study was to examine both preferences in a variety of foods and snacks and the eating habits among young children (aged 13 months through 50 months old). In addition, this study examined whether there would be significant differences in the preferences and eating habits by of young children of different ages and gender of young children. This study included 193 infants (85 boys, 108 girls) of aged 13 through 50 months of old who were enrolled in early childhood education and care settings in Seoul and Gyunggi Province. The information regarding food and snack preferences among young children were gathered through surveys filled out by their mothers and the children's overall eating habits were assessed by their teachers. The main results of this study were as follows. Overall, there were some patterns in eating bere asss and food preferences in foods and snacks among young children. There were no significant differences in both eating bere asss and food preferences by gender of young children. But, however, there were significant differences in food (p<0.001) and snack preferences (p<0.001) by of children of different ages of young children.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.680-685
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• 2015

The purpose for this study is to research the perception of happiness among the kindergarten young children. The subjects were kindergarten young children of 6, 7 years old in Kwangju. The finding of this study were as follows : 1. kindergarten young children of 6, 7 years old considered that the most important elements of happiness to have a positive mind, to be loved. And kindergarten young children of 7 years old perceived spend time with family as happiness. 2. 'the most moment when you feel happy" perceived that the most important elements of happiness were to be loved, play with children and to spend time with children. 3. 'To be happy' perceived that the most important elements of happiness were the relationship of parents and friends. Especially, seven years old children perceived to be able to do self-development. Therefore, I suggested it is necessary to study a program of young children's happiness, a program of parent's participation for young children's happiness in kindergarten, and a program of young children' career education.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.54.3-55
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• 2018

We present the physical and environmental properties of nearby dwarf elliptical-like galaxies. The present sample consists of ~ 1,100 dwarf elliptical-like galaxies within redshifts 0.01. The morphological types of the present study were determined by Ann, Seo, and Ha (2015) who classified the dwarf elliptical-like galaxies by the five subtypes of dS0, dE, dSph, dEbc, and dEblue. We examine their star formation history using STARLIGHT. The star formation history of dwarf elliptical-like galaxies depends on their subtypes. The luminosities of dS0, dE, and dSph galaxies are dominated by the extremely old stars (${\geq}10^{10}yr$) with $z{\approx}0.0004$ while those of dEbc and dEblue galaxies are mainly due to the young (${\sim}10^7yr$) stars together with the nearly equal contribution by extremely young stars (${\sim}10^6yr$) and old (${\sim}10^9yr$) stars. Young populations have a variety of metallicity, from z=0.0001 to z = 0.04, while old populations have metallicity of z = 0.0001 and z = 0.0004. While the formation history of stars older than ~1010yr depends mainly on the luminosity of galaxies, the formation history of stars younger than ~108yr is mainly affected by their environment. However, luminosity and environment are equally important for the star formation history if there is no star formation at the early phase of galaxy formation.

• Korean Journal of Child Studies
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• v.33 no.5
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• pp.117-137
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• 2012

The purpose of this study was to analyze 5'year' old children's responses in the process of reading picturebooks on sexual abuse and to explore the educational implications of the results. 42'five year' old children and 2 of their teachers participated as subjects in the study. Data was collected by means of observation, a diary record of the teacher's class, and an interview with teachers about children's responses in the process of reading picturebooks on sexual abuse during the free choice activities, and group activities in J and K daycare centers in Busan, Korea from July to September. The results were as follows : the analysis identified three patterns of responses; consistent responses, awkward responses, and confused and frightened responses. These result imply that selecting picturebooks for sexual abuse preventive education programs for young children needs to be given careful consideration. The importance of the teacher's reading skills and sociocultural cognition regarding sexuality in general were also discussed.