• Applied Microscopy
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• v.32 no.2
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• pp.107-119
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• 2002

Early spermatocytes of U. unicinctus are found in cluster floating in the coelomic fluid. The spermatocytes in a cluster form a syncytium or cytoplasmic mass, but there are no indications that the cytoplasmic mass is a component of a somatic cell. This work suggested that this type of spermatogenesis can be subordinated to solitary spermatogenesis in the sense excluding structural and functional support of a somatic cell for sperm developments. The solitary spermatogenesis in U. unicinctus is different in appearances and developmental details of sperm organelles and stage distributions from that of localized spermatogenesis. The acrosomal rudiments and centrioles can be observed in the early single cells of spermatogonia and clearly disclosed in the primary spermatocyte. In the stage of secondary spermatocyte, the acrosomal precursor and the centrioles begin to move to each cytoplasmic poles. The polarities of the organelles are attained at stage of spermatids. The spermatocytes and spermatids are arranged circumferentially along the cytoplasmic mass in which some amorphological cytoplasmic components are included. The spermatids reveal to be detached from the cytoplasmic mass into coelomic fluid. It suggests that the spermatogenesis are progressed in support of coelomic fluid, and the fact take into consideration that the spermatogenic cells can be in vitro cultured without somatic cells and with supplements of coelomic fluid.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.81-87
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• 2011

The study was conducted to select and optimize microsatellite (MS) markers for evaluate Korean Native Chicken (KNC) breeds in order to provide standard for the classification and breed definition of the indigenous breeds. The study also aimed to characterize and classify each KNC populations for inventory and management of avian genetic resources. A total of 462 chickens from 11 populations of chicken breeds including eight KNC breeds and three commercial chicken breeds were analyzed with 19 MS markers. KNC breeds, especially Long-Tail Chicken breeds, formed separate cluster from those commercial chicken breeds. Genetic distances between KNC populations (0.11~0.18) were relatively shorter. Genetic uniformity of KNC (except KNCR breed) (0.86~0.88) were higher than that of commercial breeds (except Cornish) (0.95~0.97). On the other hand, genetic uniformity of KNC Long Tail (KNCLT) were relatively higher (0.91~0.97). The result can be used to evaluate and manage animal genetic resources at national scale.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.323-332
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• 2018

The Purpose of this study was conducted to identify the effects of self growth group counseling program on the self-esteem and adaptation to school life of middle-school girls. The data were collected between November 2 and December 28, 2017. A total 24 middle-school girls at K city were participated. The collected data were analyzed using frequency, mean and standard deviation, t-test. Main results of this study were the experimental group showed significantly(p<.01) better score in the self-esteem test than the control group after taking program. And, the experimental group showed significantly better score in the teacher-student relation test(p<.05) and school classes test(p<.05) than the control group after taking program. This results suggest that there is a significance in presenting scientific evidence of self growth group counseling program. In addition, this study suggests the necessity that the self growth group counseling program for a variety of teenagers develops.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.249-265
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• 2013

The purpose of this study was to examine the influence of reading framework on writing for reflection when applied to inquiry-based Science Writing Heuristic approach. This study was conducted with 67 3rd grade middle school students. Thirty-two out of 67 students were assigned to R-SWH (Reading framework-Science Writing Heuristic) group while the other 35 students were assigned to SWH (Science Writing Heuristic) group. The R-SWH group has consistently used reading framework which the SWH group has not used when the inquiry-based science writing heuristic approach were carried out. The result of this study indicated that the R-SWH group showed a higher proportion of students who made writing for reflection by learning from reading materials than the SWH group. The R-SWH group used reading materials in order to understand the idea comprehensively and concept related to the topic the most, while the SWH group also used them for the same purpose as the R-SWH group but the ratio was less than the R-SWH group. In addition, as the learning activity has progressed, the R-SWH group showed that the proportion of students who transferred the science concept from reading materials into writing for reflection and the number of transferred concepts were higher than those of the SWH group. Therefore, the reading framework applied to inquiry-based science writing heuristic approach can facilitate a meaningful activity on reading and writing as a scaffolding to develop conceptual understanding.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.82-89
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• 1985

Morphological characteristics of leaves of 10 natural populations of Quercus mongolica and 9 natural populations of Q. serrata were investigated to study inter-population and intra-population variability as well as interspecies variability. Five leaf form indices, blade length/max. blade width, blade length/petiole length, blade length/vein number, upper 1/3 blade width/max.blade width, upper 1/3 blade width/lower 1/3 blade width, as well as petiole length and vein number were included in the present study of Leaf variabilities of the Quercus population. All of the investigated leaf variabilities except for the case of blade length/petiole length, in Q. serrata indicated highly significant differences among the populations and among the individual trees within population. Both of Q. mongolica and Q. serrata represented different leaf forms between southern populations and northern populations in the indices of blade length/max. blade width, blade length/petiole length and blade length/vein number, and so the leaf forms of northern populations were more similar to the unique characters of Q. mongolica and those of southern populations were more similar to the unique characters of Q. serrata. The variability among individual trees within population was more notable in blade length/petiole length, and petiole length than in other leaf form indices, and also it was more obvious for Mt. Kyeryrong population located in middle part of the country than for other population.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.26-34
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• 2015

This study was conducted to examine the morphological characteristics and variations of the 6 populations of Pourthiaea. villosa (Thunb.) Decne. var. villosa in Korea. The ANOVA results showed that the populations were significantly different in 18 of the 21 quantitative characteristics that were analyzed. In the results of principal component analysis, 6 principal components (PC) represented 68.28% for the total variations. 'Petiole length' (0.764), 'Leaf shape' (0.834), 'Leaf length' (0.753), 'Crown diameter' (0.663), 'Inflorescence width' (0.492), and 'Leaf base shape' (0.721) showed the highest contribution to PC1, PC2, PC3, PC4, PC5, and PC6, respectively. According to the results of cluster analysis, one cluster comprised only 'Goesan-gun Ssanggok Valley' population. 'Namhae-gun Mijori Evergreen Forest' population was grouped with 'Hamyang-gun Sang Forest' population, which was the nearest subgroup. Further, 'Namhae-gun Geum Mountain' population, 'Jindo-gun Cheomchal Mountain' population, and 'Jeju-si Barimae Parasitic volcano' population were placed in the same cluster.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.95-105
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• 2011

To explain the origin of the Korean mandarin fish (Siniperca scherzeri), phylogenetic relationships and DNA polymorphism among Siniperca fishes have been investigated based on mitochondrial cytochrome b DNA sequences. As a result, S. roulei were firstly differentiated early in the evolution of Siniperca fishes and the other six species (S. schezeri, S. undulata, S. fortis, S. obscura, S. knerii and S. chuatsi) were evolved slightly later. However, the order of species differentiation among six species was not clear because the nodes of their phylogeny were poorly resolved. The constructed molecular phylogeny revealed three genetically distinct groups of local populations of S. scherzeri. The first group (group 1) is the local populations of Korean peninsula and northern China including Lioaning and Henan. The second one (group 2) is the local populations of Anhui, Fujian and Guangxi. The third one (group 3) is the local population of Zhejiang. The number of nucleotide differences in base pairs were 31~43 between group 1 and 2; 37~44 between group 2 and 3; 27~29 between group 1 and 3; and 1~5 within group 1. Thus, the Korean mandarin fish was likely to be originated from the northern China local population which was isolated from the middle or southern China local populations during the Cenozoic Pliocene. Low level of sequence divergence between Korean mandarin fish populations and northern China population indicated a recent expansion of distribution ranges from northern China to Korean peninsula.

• Korean Journal of Childcare and Education
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• v.10 no.6
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• pp.347-368
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• 2014

The purpose of this study was to examine whether there was a difference in the recognition and teaching strategies for the young child's behavioral problems according to teachers' socio-demographic variables and ego-resiliency level by analyzing survey responses from 238 teachers of 3, 4, and 5-year-old children. This study found that the group of teachers with the education level of junior college graduation or higher showed higher degree of recognition of children's behavioral problems than the group of teachers with a lower level of education. And the group of teachers at kindergartens showed a higher degree of recognition of children's behavioral problems than the group of teachers at day care centers. Regarding the difference according to the level of ego-resiliency, the group of higher ego-resiliency showed higher degree of recognition of children's behavioral problems than the group of lower ego-resiliency. In terms of teachers' teaching strategies for the behavioral problems, differences were recognized at sub-categories. To explain, differences were recognized in accordance with the teachers' age and career as well as their education level and work place; the higher the teachers' age, career, and education the more often they used the positive prevention strategy I. And teachers at kindergartens resorted to the negative response strategies more often than those at day care centers. Finally, the teaching strategies for the behavioral problems according to the teachers' ego-resiliency, group differences were seen in all the sub categories. The result of this study suggested that the need to develop and apply such programs for pre-service teachers and for teacher reeducation reflect those variables.

• Journal of The Korean Association For Science Education
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• v.32 no.7
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• pp.1099-1108
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• 2012

The purpose of this study was to examine the effects of argument structure on students' writing in implementation of argument-based inquiry using the Science Writing Heuristic (SWH) approach. Participants of this study were 108 8th grade students (three classes). Two classes (68 students) were assigned to an experimental group, and the other class (35 students) was assigned to a comparative group. The experimental group was taught argument-based inquiry using the Science Writing Heuristic (SWH) approach, while the comparative group was taught with the traditional teaching strategy. After implementing this program, the two groups were asked to write summaries using structured argumentation in their writing. The result of this study showed that the experimental group used better argument structure and multimodal representation such as pictures, graphs and examples in evidence than the comparative group. The quality of evidence used in the students' writing was different between two groups. Students of the comparative group only listed fragments of science concepts for evidence to support their claims, but students of the experimental group explained science concepts by giving specific examples. The findings show that argument-based inquiry using the SWH approach was effective on argument structure in students' writing.

• Journal of Gifted/Talented Education
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• v.19 no.2
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• pp.279-302
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• 2009

This paper was to examine the effects of university-based science gifted education program on scientifically gifted students' science problem finding ability and cognitive-affective factors. For this study, 69 scientifically gifted students with previous Silted education experiences at the university-based science gifted education centers and 91 scientifically gifted students without any previous gifted education experiences were compared. Both groups of students were currently enrolled at a specialized science high school. To compare both groups, scientific problem finding ability, science anxiety, science related attitude, self-efficacy, intrinsic motivation, test anxiety, cognitive strategies, and self-regulation were measured. The results indicate that there was no significant difference on scientific problem finding ability between these two groups. The comparison between the past and now in the aspects of variables observed in the study showed that both groups of students were decreased in the science anxiety and self-efficacy. But the test anxiety was significantly increased compared to the past in both groups. Implications of the study were discussed in depth.