• Journal of the Korean earth science society
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• v.29 no.4
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• pp.352-362
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• 2008

This study explored pre-service teachers' mental models about eclipse phenomena to investigate their understandings on the earth science concept needed f3r an integrated approach. We conducted in-depth interviews with two different contexts on 30 secondary and 36 primary pre-service teachers participants, and analyzed phenomenological primitives (p-prims) and facets of causal explanations about eclipses. Based on this study, we identified four different levels of mental models about eclipses. Four mental models were categorized as (1) Screening model, (2) Orbital plane model, (3) Hybrid model, and (4) Shadow cast model. Screening model is a flawed mental model, orbital plane model is an incomplete correct mental model, and shadow cast model is a scientifically correct mental model. Hybrid model, composite of two or more mental models, use multiple mental models simultaneously. Orbital plane model was the most widespread mental model in secondary pre-service teachers group, whereas screening model was used frequently in primary group. It was found that the level of mental model could be determined by the level of facet and p-prims. We confirmed context sensitivity of the mental models and perceived the necessity of integrated approaches to promote progression of mental models. Implications of our findings for enhancing pre-service science teachers' topic-specific pedagogical content knowledge (PCK) associated with eclipse phenomena are also discussed here.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.431-440
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• 2018

The purpose of this study is to investigate the characteristics of the K Teachers' Community, which brought about changes in the perception of SSI education by teachers with experience in SSI, and to explore its relevance to the development of SSI professions. This is a case study that describes in depth the characteristics of the K teachers' community. The study conducted semi-structured as well as in-depth interviews with six teachers who have more experience in SSI education activities for over 20 years. The K teachers' community has three characteristics. First, the K teachers' community formed identity by discussing the nature of science and technology, which allowed teachers to share a common orientation toward the goals of science education. Second, the teachers who participated in the K teachers' community formed professionalism and confidence in SSI teaching in the course of producing, sharing, and spreading SSI through its various practices. Third, the K teachers' community is continuously growing by opening themselves to external communities and co-evolution through solidarity. The success of K Teachers' Community may inform other teachers how the community of teaching practices can develop and maintain, and in turn can help the members of the community develop their professional identity as teachers.

• Journal of The Korean Association For Science Education
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• v.34 no.5
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• pp.449-457
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• 2014

Recent studies have shown that teachers should have be aware of and understand students' misconceptions, which is one of the major components of PCK. However, teachers often have difficulties in understanding misconceptions and in applying appropriate instructional strategies to change misconceptions. Thus, we designed a method course for pre-service teachers (PSTs) adapting the concept of "teacher as researcher". In the course, PSTs conducted research to investigate students' misconceptions in physics. Twenty-five female PSTs participated in the study. They went through the research process including creating question items, administering items to their target populations, collecting and analyzing student responses, and writing a research paper. Data source included individual interviews with the PSTs, field notes during classroom observation and PSTs' research papers. The results were as follows. First, the PSTs confirmed students' misconceptions and learning difficulties in physics. They experienced discrepancies between their conjecture and research findings. Second, PSTs developed the sophisticated understanding of students' misconceptions and appropriate teaching strategies. Third, the research experience provided the PSTs opportunities to reexamine their physics content knowledge while creating items and explaining scientific concepts. They realized that physics teachers should develop sound understanding of physics concepts for guiding students to have less misconception. Lastly, they realized the necessity of being a teacher as a researcher.

• BMB Reports
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• v.32 no.4
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• pp.339-344
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• 1999

We studied the effects of ginsenosides in immature rats based upon the previous results that ginseng has a suppressive or anticonvulsive activity. To examine the suppressive effect of ginsenosides on kainic acid-induced seizures, the severities and frequencies were observed for 4 h after injection of kainic acid (KA; i.p., 2 mg/kg b.w.) using 10-day-old male Sprague-Dawley rats ($22{\pm}2\;g$). Protopanaxadiol saponins such as ginsenoside-Rb1 (Rb1), ginsenoside-Rb2 (Rb2), ginsenoside-Rc (Rc), and ginsenoside-Rd(Rd) generally reduced the seizure activities while protopanaxatriol saponins such as ginsenoside-Rg1 (Rg1) and ginsenoside-Re (Re) rather increased stereotypic "paddling-like" movements. When vinyl-GABA (v-G) was injected together with Rb1 or Rc, KA-induced seizure severities were additionally reduced only by the injection of Rc, but not by Rb1. The level of gamma isozyme of protein kinase C (PKC-${\gamma}$) in the hippocampus increased about three times as much as that of normal rats at 4 h after KA injection. The increased level of PCK-${\gamma}$ by KA was significantly reduced to about 35% by the coinjection with v-G alone, but it was not changed by v-G together with Rb1 or Rc. The increased level of PKC-${\gamma}$ at 4 h after injection of KA was not consistent with the reduction of seizure severities between Rb1 and Rc. These results suggest that Rc and Rb1 may reduce seizure severity independent of PKC-${\gamma}$ levels, and Rc may additionally act with v-G regarding the GABA metabolism during the stage of KA-induced seizures in the immature rats.