• Journal of Korean Elementary Science Education
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• v.25 no.3
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• pp.281-295
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• 2006

The purpose of this study was to analyze laboratory instructions used in elementary school science lessons by utilizing an analysis instrument for science laboratory instruction(AISLI). This analysis instrument was comprised of 3 elements; the aim of the laboratory activity, the interaction generated, and the inquiry process. There were also a total of 20 sub-categories and its validity was identified at 0.89 by four science educators. For the purposes of this study, 90 laboratory instructions were video-recorded, then transcribed. Laboratory instructions were analyzed by three analyst teams, and the inter-rater reliability within teams was checked through Pearson correlation, with a score of 0.91. The results of this study were as follows: the two principle aims of laboratory activity, namely, to acquire declarative knowledge and to increase attitudes toward science, were observed to be in evidence in 98.9% and 92.2% in laboratory instructions, and the levels of categories of the interaction and inquiry processes were situated at level-1. The implications of these results are that laboratory instructions currently in use do not place sufficient demands upon students' scientific thinking and are not at all conducive to student-centered activities. Therefore in order to remedy this situation, the usefulness of current science laboratory instructions need to be re-evaluated.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.325-333
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• 2011

This study focused on the green peach aphid, Myzus persicae, as an indicator pest in Chinese cabbage cultivation to develop a genetic marker. We hypothesized that M. persicae gene flow is related to climate change. Genetic variation was analyzed using five local populations collected at different altitudes (157 m, 296 m, 560 m, 756 m and 932 m above sea level) in Hoengseong, Pyeongchang, and Gangneung areas, plus a laboratory strain used as an outgroup. There were no differences in ecological characteristics among strains. Esterase isozyme pattern and inter-simple sequence repeat (ISSR) PCR results showed significantly different bands between laboratory and wild, local populations. However, there was no difference among local populations. Partial fragments of ribosomal RNA (rRNA) and mitochondrial cytochrome oxidase I (mtCO I) were amplified and their nucleotide sequence was analyzed. Single nucleotide polymorphisms (SNPs) were detected in internal transcribed spacer-2 (ITS-2) and mtCO I regions among the five local populations. These SNPs can be use to discriminate different populations of M. persicae to monitor gene flow.

• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.209-213
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• 2012

Members of the ciliate group of protozoans are often observed in mass cultures of rotifers. In particular, Euplotes and Vorticella are common contaminating species. In this study, I examined the effect of the ciliates Euplotes sp. and Vorticella sp. on the growth of the rotifer Brachionus rotundiformis by conducting inter-specific and tripartite-specific mixed-culture experiments. The growth of rotifers was suppressed in co-existence with Euplotes sp. compared with monocultures of rotifers. However, Vorticella sp. promoted rotifer growth. Moreover, Vorticella sp. improved the growth of rotifers suppressed by Euplotes sp. contaminants. In 5-L semi-mass cultures of rotifers, growth of the contaminating protozoan Euplotes sp. was heavily suppressed by Vorticella sp. The stable maintenance of the rotifer culture ecosystem can be achieved by manipulating the types of contaminating protozoan species.

• Analytical Science and Technology
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• v.34 no.4
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• pp.180-190
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• 2021

This study compared the efficacy of chiral GC and chiral HPLC for the analysis of nicotine. To develop a suitable dispersive liquid-liquid microextraction (DLLME) method, the following parameters were optimized: pH, extraction solvent, dispersive solvent, type and quantity of salt, and laboratory temperature. The validation of the method was carried out by the established HPLC method. The LODs were 0.11 ㎍/mL and 0.17 ㎍/mL for the (S)- and (R)- enantiomers, respectively. The LOQs were 0.30 ㎍/mL and 0.44 ㎍/mL, respectively. The optimal calibration range was between 0.30-18 ㎍/mL and 0.44-4.40 ㎍/mL, respectively, and the correlation coefficient (r²) was 0.9978-0.9996. The intra-day accuracy was 79.9-110.6 %, and the intra-day precision was 1.3-12.0 %. The inter-day accuracy was 87.8-108.0 %, and the inter-day precision was 4.0-12.8 %. E-liquid and biological fluids (urine and saliva) were analyzed using the established method.

• Korean Journal of Transplantation
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• v.31 no.4
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• pp.170-176
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• 2017

We need to establish an informative guideline to increase inter-institutional and inter-observer reproducibility of renal transplant diagnosis, and to improve the diagnostic ability of pathologists in Korea. A first nation-wide survey for renal transplant pathology was conducted by Renal Pathology Study Group of the Korean Society of Pathologists in 2016, to provide the continued excellence in the transplantation pathology laboratory, and to improve the diagnostic ability for the best treatment of transplant patients. This survey revealed the significant variations in scale, work load and biopsy indications for the renal transplant pathology in various institutions in Korea. The Banff classification were used by all institutions for the diagnosis of renal transplant pathology, but different formats were used: most institutions (70%) used the "2013 Banff classification" while the others were using "2007 Banff classification" (20%) or even older formats. In daily diagnostic practice of the renal allografts, difficulties that pathologists encounter were quite diverse due to different environments they work in. Most respondents agreed that standardized diagnostic practice guidelines, regular education on renal transplant pathology and convenient ways of consultation are further needed. We are currently working toward the enhancement of the expertise of renal pathologists and to increase inter-institutional and inter-observer reproducibility by 1) development of a set of virtual slides of renal allograft biopsies for the training, 2) validation and gathering expert's consensus on the core variables of rejection diagnosis by using virtual slides, and 3) continued education by the developed virtual slide atlas.

• Journal of Communications and Networks
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• v.15 no.3
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• pp.312-320
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• 2013

Home evolved Node-B (HeNB), also called a femtocell or a femto base station, is introduced to provide high data rate to indoor users. However, two main problems arise in femtocell networks: (1) Small coverage area of HeNB, which results in limited cell-splitting gain and ping-pong handover (HO) problems and (2) high inter-femtocell interference because HeNBs may be densely deployed in a small region. In this study, an efficient cooperation mechanism called an HeNB-aided virtual-HO (HaVHO) scheme is proposed to expand the coverage area of femtocells and to reduce inter-femtocell interference. The cooperation among neighbor HeNBs is exploited in HaVHO by enabling an HeNB to relay the data of its neighbor HeNB without an HO. The HaVHO procedure is compatible with the existing long term evolution specification, and the information exchange overhead in HaVHO is relatively low. To estimate the signal to interference plus noise ratio improvement, the area average channel state metric is proposed, and the amount of user throughput enhancement by HaVHO is derived. System-level simulation shows that HaVHO has a better performance than the other four schemes, such as lesser radio link failure, lesser ping-pong handover, lesser short-stay handover, and higher user throughput.

• Journal of The Korean Association For Science Education
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• v.27 no.3
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• pp.235-241
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• 2007

The purpose of this study was to identify the main laboratory instruction types with Classification Scheme of Laboratory Instruction (CSLI) in elementary and secondary schools science. For the purpose, the validity of the instrument CSLI was 4.23 and laboratory instructions were collected in 100 elementary schools and 30 secondary schools. Before analyzing the collected laboratory instructions, the inter-rater reliability about the analysis results was identified as 0.91. The results of this study were found that in elementary school, the main laboratory instruction types were verification type and discovery type and in secondary school were discovery type and verification type. In the category of the procedure, a large part of the procedures of laboratory activity in both elementary and secondary schools was given to students by worksheets or teachers themselves. In the category of approach, inductive approach was the main in elementary and deductive approach in secondary.

• Journal of the Korean earth science society
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• v.30 no.5
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• pp.660-670
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• 2009

This study examines the changes of an interdecadal circulation over the Asian continent to find cause of the surface warming in Siberia from 1958 to 2004. According to our study, there is a coherency between a long-term change of sea surface temperature in the Indian Ocean and the rapid increase of air temperature in Siberia since 1976/1977. In this study, we suggest that mean wind field changes induced by the positive sea surface temperature anomalies of the Indian Ocean since 1976/1977 are caused of inter-decadal variations in a large-scale circulation over the Asian continent. It also indicates that the inter-decadal circulation over the Asian continent is accompanied with warm southerly winds near surface, which have significantly contributed to the increase of surface temperature in Siberia. These southerly winds have been one of the most dominant interdecadal variations over the Asian continent since 1976/1977. In addition, we investigated the long-term trend mode of 850 hPa geopotential height data over the Asian continent from the Empirical Orthogonal Function (EOF) analysis for 1958-2004. In result, we found that there was an anomalously high pressure pattern over the Asian continent, it is called 'the Asian High mode'. It is thus suggested that the Asian High mode is another response of interdecadal changes of large-scale circulations over the Asian continent.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.105-112
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• 2005

Buffer soluble protein and five isozymes were analyzed to assess the inter specific relationship among 25 species of the genus Mammillaria Haw. A total of 102 types of proteins were resolved, out of which eighty-six types were found to be polymorphic and only two were unique. A total of 248 bands (isoforms) were detected for 5 isozymes, among them only 4 were found to be monomorphic and 35 were exclusive. Mantel 'Z' statistics revealed wide variations in the correlation among different enzymes. The correlation value 'r' was the highest in case of esterase with pooled data of all the five enzymes. The dendrogram constructed on the basis of pooled data (protein and allozyme) divided the species into two major clusters containing 14 and 11 members respectively. The species M. matudae and M. bella were found to be the most closely related while M. decipience and M. camptroticha were distantly apart. The present study gave an indication of usefulness of the isozyme and protein markers for genetic discrimination between different species of Mammillaria.