• The Journal of Korean Academy of Sensory Integration
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• v.3 no.1
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• pp.1-11
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• 2005

Objective : The purpose of this study was to get the mean of duration of post-rotatory nystagmus test in normal children and to differentiate the duration of post-rotatory nystagmus test between normal children and children with pervasive developmental disorder. Method : 84 subjects were between 3 and 5 years of age and consisted of 64 normal children and 20 children with the pervasive developmental disorder. Analysis of the data was done by using t-test and ANOVA. Results : The results were as follows: 1. Range of duration of post-rotatory nyatagmus test in normal children was $5{\sim}22$second on left and $7{\sim}21$ second on right and the mean was 12.63 second on left and 12.59 second on right. 2. Range of duration of post-rotatory nystagmus test in children with the pervasive developmental disorder was $3{\sim}11$ second on both and the mean was 5.65 second on left and 5.60 second on right. 3. There was no significant difference between males and females with normal children in duration of post-rotatory nystagmus test. However, there was a significant difference of the mean duration between 3 and 5 years old normal group. 4. Children with pervasive developmental disorder significantly have relatively lower duration than the duration of post-rotatory nystagmus test of normal children. Conclusions : The results of the study showed significant difference between normal children and children with pervasive developmental disorder in duration of post-rotatory nystagmus test and suggest that they could be applied to the baseline of clinical therapy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.149-153
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• 1999

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.

• Journal of Life Science
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• v.10 no.2
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• pp.164-168
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• 2000

To understand the biological characteristics of Corythucha ciliata occurring in Korea, developmental periods and its susceptibility to several insecticides were examined under growth chamber condition at $25^{\circ}C$. It took 11.1 day from egg to hatch. And duration of each stage up to the 5th nymph after hatching was 4.0, 2.1, 2.0, 2.9, and 4.0 days, respectively. Total duration from egg to adult was 26.1 days, preoviposition period was 12.2 days, and average number of eggs laid by a female was 83.0. Sex ratio of female was 51.6% and lifespan of female adult was 43.2% days. LC50 value of deltamethrin and esfenvalerate were 0.8 and 0.9 ppm, respectively. Insecticidal effects were better in pyrethroids than organophosphates and carbamates.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.291-300
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• 2019

The purpose of this study was to investigate the effects of a tactile-oriented sensory-motor developmental program on the visual attention and stereotypical behavior of an adolescent with intellectual disability. The subject was an adolescent with intellectual disability attending a special school located in B-gun, A-province of South Korea, with whom an A-B-A' design individual target study was conducted between August 27 and December 12, 2018. The intervention consisted of twelve 40-minute sessions, which were provided twice a week. For every session, two types of evaluation were conducted: a test that required staring at objects for visual attention, as well as an observation record for identifying the frequency and duration of stereotypical behavior. The results of this study showed that the tactile-oriented sensory-motor developmental program had positive effects on the duration of the participant's ability to stare at objects and the frequency and duration of stereotypical behavior. As this study confirmed and usefulness of this tactile-oriented sensory-motor developmental program as an intervention for improving the visual attention, and stereotypical behavior of adolescent with intellectual disabilities, the program may be employed to help members of this groups who have problems with sensory processing.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.153-161
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• 2014

The aim of this study is to investigate the effects of ambient thermal environments on the development of swallowtail butterflies (Sericinus montela Gray). Developmental durations and survival rates of S. montela were examined at two crucial developmental stages, embryonic and larval development, at varying temperatures ranging from $15^{\circ}C$ to $35^{\circ}C$. As expected, our results indicated that increasing temperatures decreased the developmental duration and survival rate of the eggs. However, the larvae and pupae showed maximum survival rates at $20.0^{\circ}C$ and $25.0^{\circ}C$, and the represented durations were similar to those of the eggs. Larval development was stage-specific, revealing that the fourth and fifth instars at the later stages were more susceptible to temperature variation. When considering both parameters, the optimal development of S. montela occurred within the temperature range of $20.0-25.0^{\circ}C$. The lower threshold for the complete development of S. montela from eggs to eclosion of adults was calculated at $10.6^{\circ}C$ by linear regression analysis. The estimated value is similar to that of other endemic insects distributed in temperate climate zones, which indicates that S. montela belongs to a small group of swallowtails adjusted to low ambient temperatures. From the results, we predict that the full development of S. montela could be achieved within the temperature range of $17.5-30.0^{\circ}C$. Embryonic development ceased at both test temperature extremes, and no further larval development proceeded after the third instar at $35.0^{\circ}C$. These results suggest that embryogenesis can be significantly influenced by slight variations in the ambient thermal environment that fall below the optimal range.

• Korean Journal of Child Studies
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• v.34 no.5
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• pp.1-16
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• 2013

This study examined the effects of paternal smoking on the developmental levels of children younger than 3 years of age. For this purpose, the paper made use of data from the Panel Study on Korean Children which has been released in 3 waves - 2008, 2009, and 2010. The main findings are as follows. First, the smoking characteristics of parents (e.g., the amount of smoking in the morning, the time starting the first cigarette of the day) rather than the duration of smoking or whether the father smoked or not revealed significant relationships with developmental levels. Second, children whose fathers preferred smoking in the morning exhibited lower activity levels or more areas with developmental delays than did their counterparts. Third, children whose fathers smoked more than 11 cigarettes a day were more likely to show problematic developmental levels, especially among those whose fathers responded so only for 1 year out of 3 years. Based on these findings, this study suggests that future research may be conducted, relating to the mechanisms through which morning smoking affects children and possible interventions for such morning smokers.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.221-226
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• 2004

The present study was performed to investigate the effects of in vitro maturation (IVM) and in vitro fertilization (IVF) duration on the development of Korean Native Cattle embryos. The time of blastocyst formation and the quality of blastocysts based on cell numbers were examined. The cleavage rate increased with the length of IVF duration in the groups of 18-hr IVM, but was constant in the groups of 24-hr IVM. The development rate to the 8-cell stage was significantly higher in the IVM 18: IVF 20 group than in the IVM 24: IVF 24 group. The development rate to the blastocyst stage was highest in the IVM 18: IVF 20 group, significantly different from that of the IVM 18: IVF 16, IVM 24: IVF 20 and IVM 24: IVF 24 group. The time of blastocysts formation tended to be shorter when IVM and IVF duration were decreased. The number of inner cell mass, trophoblast and the total cells were significantly higher in the IVM 18: IVF 16 group than in the IVM 24: IVF 24 group (P<0.05). These results demonstrated that the IVM and IVF duration should be adequate for the efficient production of bovine embryos, and it might particularly be essential to determine the proper combination of IVM and IVF duration.

• Korean Journal of Child Studies
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• v.37 no.3
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• pp.13-26
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• 2016

Objective: The purpose of this study was to investigate the relationship between sleep duration and school adjustment of elementary-, middle-, high-school youth and to verify the mediating effects of parenting behavior. Methods: We analyzed the data from Wave 4 of the first-grade panel of elementary school and Waves 1 and 4 of the first-grade panel of middle school in Korean Children and Youth Panel Survey (KCYPS), including 1,703 fourth graders, 2,119 seventh graders, and 2,108 tenth graders. Multiple regression was used for the data analyses. Results: The results of this study were as follows. First, longer sleep duration was associated with a higher level of school adjustment in fourth grade. In contrast, longer sleep duration was associated with a lower level of school adjustment in seventh and tenth grades. Second, longer sleep duration was related to a higher level of discipline through reasoning in fourth grade. However, longer sleep duration was related to a lower level of parental monitoring in seventh and tenth grades. Third, the relationship between sleep duration and school adjustment was mediated by parenting behavior. Discipline through reasoning had a mediating effect in fourth grade, but the mediating effect of parental monitoring was found in seventh and tenth grades. Conclusion: These results suggest a differentiated approach on sleep duration in accordance with developmental stage and the need for parent education.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.192-204
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• 2023

This study aimed to determine the criteria for quantifying developmental defects of enamel in primary teeth in premature babies and to investigate the severity of developmental defects according to the gestational age, birth weight, systemic complications, and treatments received after preterm birth. Birth information, a history of complications, the duration of parenteral nutrition, and endotracheal intubation were investigated by retrospectively reviewing the admission and discharge records of premature babies in the neonatal intensive care unit. The Preterm Developmental Defects of Enamel (PDDE) index was designed by modifying the existing developmental defects of enamel index. Based on PDDE index, the evaluator scored developmental defects of enamel by classifying them as enamel hypomineralization and hypoplasia. The PDDE scores in the extremely preterm and extremely low birth weight groups were significantly higher than those in other groups. Furthermore, PDDE scores of premature babies with bronchopulmonary dysplasia, rickets, intraventricular hemorrhage, or necrotizing colitis were significantly higher than those in the control group. In addition, more than 50 days of endotracheal intubation and more than 20 days of parenteral nutrition were associated with significantly higher PDDE scores than those in the control group and were risk factors for developmental defects of enamel. This study provides basic information for identifying risk factors for developmental defects of enamel in premature babies.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.449-455
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• 1991

The water striders, gerris paludum insularis larvae which were fed with the drosophila melanogaster cultured on the appli diet and artificial diet, were reared in the growth cabinet controlled as the two constant temperature regimes of 25 c and 30 c under the condition of photoperiod 16l : 8d, light intensity 510 240 lux, relative humidity 65 3%, and in the natural state. The effects of temperature and diet on the devolopment of g. paludum insularis were analyzed and the results were summarized as follows. 1. The total developmental period of the water strider larvae fed with the d. melanogaster reared on the apple diet at the natural stste was the longest 40 days, and the total devopmental periods at 25 c and 30 c were 35 days and 27 days respectively. The tolal developmental period of larvae fed with d. melanogaster reared on the artifical diet at 25 c was the longest 42 dats, and the total developmental periods at natural stste and 30 c were 32 days and 27 days, respectively. 2. In the larval developmental stages, the fifth stage was longer than that of any stage. The duration of egg stage which was not influenced by diet at 25 c was the longest. 3. The water strider larvae fed which the d. melanogaster reared on the artificial diet at 25 c did not complete their devolopment. 4. No significant difference was odserved in the developmentperiod for diet at 30 c. but, there were significant differences in developmental periods for diet at 25 c and natural state. 5. The rate of adult emergence on the apple diet was higher than that of the artificial diet was higher than of the artificial diet. 6. The shapes of the survivorship curve were convex-curve. 7. The development periods of the larval stages of water striders might be affected to temperature and diet dependently.