• Animal cells and systems
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• v.7 no.1
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• pp.49-55
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• 2003

The fiber projection from the prefrontal cortex to the locus coeruleus (LC) in the periventricular region was analyzed in rat using anterograde and retrograde tracing methods. Following injection of an anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHA-L), into prelimbic and infralimbic regions of the medial prefrontal cortex, labeled axonal fibers with varicosities were observed bilaterally within the LC, with ipsilateral predominance. Terminal labeling was also observed in the region medial to the nucleus at rostral to middle levels of the LC, whereas axonal labeling in the caudal LC was minimal. Anterogradely-labeled axonal fibers were not found in the subcoerulear region. A retrograde tracer, gold-conjugated and inactivated wheatgerm-agglutinin horseradish-peroxidase (WGA-apo-HRP-gold), was injected into several rostro-caudal levels of the LC. Majority of retrogradely-labeled cells were observed in the prelimbic or infralimbic regions of the medial prefrontal cortex when the injections were made into rostral to middle levels of the LC. Only a few cells were observed in cingulate, dorsal peduncular, orbital, or insular cortices. The present findings suggest that the nucleus LC receives restricted, excitatory inputs from cognitive, emotional, and autonomic centers of the cerebral cortex and might secondarily have influences on widespread brain regions via its diversified monoaminergic innervation.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.287-299
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• 2020

Cystic echinococcosis (CE) is a zoonotic infection caused by Echinococcus granulosus larvae. It seriously affects the development of animal husbandry and endangers human health. Due to a poor understanding of the cystic fluid formation pathway, there is currently a lack of innovative methods for the prevention and treatment of CE. In this study, the protoscoleces (PSCs) in the encystation process were analyzed by high-throughput RNA sequencing. A total of 32,401 transcripts and 14,903 cDNAs revealed numbers of new genes and transcripts, stage-specific genes, and differently expressed genes. Genes encoding proteins involved in signaling pathways, such as putative G-protein coupled receptor, tyrosine kinases, and serine/threonine protein kinase, were predominantly up-regulated during the encystation process. Antioxidant enzymes included cytochrome c oxidase, thioredoxin glutathione, and glutathione peroxidase were a high expression level. Intriguingly, KEGG enrichment suggested that differentially up-regulated genes involved in the vasopressin-regulated water reabsorption metabolic pathway may play important roles in the transport of proteins, carbohydrates, and other substances. These results provide valuable information on the mechanism of cystic fluid production during the encystation process, and provide a basis for further studies on the molecular mechanisms of growth and development of PSCs.

• Journal of The Korean Association For Science Education
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• v.11 no.1
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• pp.73-81
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• 1991

The condensed results of the analytical study on 361 doctoral dissertations in science education recorded in Dissertation Abstracts International during the years of 1985-1989 are as follows: About eighty to hundred dissertations were produced annually, but a slight decline in number was noted currently. About 94.4% of dissertations were produced by the universities in the USA The research data of 361 dissertations were collected from 25 countries. Over 40% of total dissertations had been focused on high school(senior middle school) and college students as the source of research. Disciplines of science constituting the background of dissertations were biology(l9.l%), physics(l2.7%), chemistry(12.0%) and earth science(2.5%). Concerning the research branches, the number of dissertations belonging to complex research(composed of experimental and theoretical research) was 118(32.7%) and those belonging to experimental and theoretical research were 88(24.4%) and 74(20.5%) respectively. Also that belonging to computer-aided research was 45(12.5%). The general methods of data collection were examination & test(34.9%), questionaire(22.2%) and complexmethod(9.1%). The main areas of dissertations were academic achievement(31.8%), teaching assessment(20.2%) and pedagogy(l8.8%).

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.235-245
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• 1993

The symbiotic properties of arbuscular mycorrhizal fungi(AMF) such as the absence and/or presence of symbiosis, spore density, and six factors of phycochemical properties of soil were investigated in the rhizosphere of seven sand dune plants and three control plants around Kum river. The infection of AMF was confirmed in all plants. Three genera, nine species of the AMF spores were identified in the sand dune; Ac. scrobiculata, G. aggregatum, G. convolutum, G. diaphanum, G. dimophicum, G. geosporum, G. vesiculiferum, G. tortuosum, S. pachycaulis. All of them were also found in the control, but S. pachycaulis were only separated in the sand dune. In the control, three genera, four species were identified; G. flavisporum, Gi. margarita, Sc. gregaria. Sc. persica. The species specificity was not found between the sand dune plant and AMF. However, the AMF was thought to be correlated with the soil factors. The spore density was stimulated with increase of the organic matter and the nitrogen content, but inhibited with the water content and the phosphorus content. In respect of the seasonal factor, the spore density was increased in the late growth period of plants.

• Journal of environmental and Sanitary engineering
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• v.3 no.1 s.4
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• pp.19-26
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• 1988

This Study was performed from Feb. 4th Feb. 15th. 1985 in order to investigate if the rate of the contamination of students' hands were affected by sexes and grades of middle school. The sampled 29 students were selected from the 1st. and 2nd. grades of the middle school. The hands-washed salines were cultured for the isolation of microorganisms. The results were as follows: 1. It was found to be contaminated by 17 Genera of bacteria such as Staphylococcus, Streptococcus, Micrococcus, Bacillus, Neisseria, Branhamella, Acinetobacter, Moraxella, Ozromobacterium, Alcaligenes, Flavobacterium, Pseudomonas, Actinobacillus, Pasteurella, Vibrio, Enterobacteria and Plesiomonas. 2. The strains from 30 isolates were identified as 9 species, Staphylococcus aureus, Staphylococcus epidemidis, Micrococcus varians, Branhamella catarrhalis, Acinetobacter anitratus, Moraxella bovis, Moraxella urethralis, Pseudomonas aeruginosa and plesiomonas shigeiloid. 3. The frequency rates on 17 Genera appearances on Students' hands were Staphylococcus $(96.6\%)$, Enterobacteria $(41.4\%)$, Bacillus $(20.7\%)$, Branhamella $(17.2\%)$ et. 4. There was significant difference in cell number between hans of boys & girls. The rate of contamination of girls' hands, especially 2nd grade girls, was lower than boys' hands. This result showed that girls' hands were more clean.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.162-172
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• 2002

Schizosaccharomyces pombe is suited for the study of cytokinesis as it divides by forming a septum in the middle of the cell at the end of mitosis. To enhance our understanding of the cytokinesis, we have carried out a genetic screen for temperature-sensitive S. pombe mutants that show defects in septum formation and cell division. Here we present the isolation and characterization of a new temperature-sensitive mutant, sun1(septum uncontrolled), which undergoes uncontrolled septation during cell division cycle at restrictive temperature $(37^{\circ}C)$. In sun1 mutant, actin ring and septum are positioned at random locations and angles, and nuclear division cycle continues. These observations suggest that the sun] gene product is required for the proper placement of the actin ring as well as precise septation. The sun] mutant is monogenic recessive mutation unlinked to previously known various cdc genes of S. pombe. In a screen for $sunl^+$ gene to complement the sun] mutant, we have cloned a gene, $susl^+$(suppressor of sun1 mutant), that encodes a protein of 689 amino acids. The predicted amino acid sequence of $susl^+$ gene is similar to the human hMadlp and Saccharomyces cerevisiae Mad1p, a component of the spindle checkpoint in eukaryotic cells. The null mutant of $susl^+$ gene grows normally at various temperatures and has the increased sensitivity to anti-microtubule drug, while $susl^+$ mutant shows no sensitivity to microtubule destabilizing drugs. The putative S. pombe Sus1p directly interacts with S. pombe Mad2p in yeast two-hybrid assays. These data suggest that the newly isolated susr gene encodes S. pombe Mad1p and suppresses sun] mutant defective in controlled septation in a cell division cycle.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.469-478
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• 2006

The composition changes of litters were investigated to figure out the effects of the decomposition of Humulus japonicus on nutrient circulation and decomposition process in the riverine wetlands: Tan stream and Amsa-dong. Litterbags (mesh size 1 mm and 5 mm) were installed to monitor mass and nutrient changes of 5 types of litters: H. japanicus only, Miscanthus sacchariflarus only, Phragmites communis only, mixed litters including H. japonicus, and mixed litters without H. japonicus for 7 months. It was shown that k (decay rate) of the H. japanicus ($2.68{\sim}3.12$) was higher than that of M. sacchariflorus ($1.83{\sim}2.16$) and P. communis ($0.02{\sim}1.18$). The mass and organic remainings of the mixed litters including H. japonicus at Tan stream were $47.0{\sim}55.1%\;and\;47.0{\sim}54.9%$ and those of the litterbags without H. japanicus were $49.2{\sim}65.4%\;and\;47.1{\sim}57.5%$, respectively. This result indicated that the nutrient circulation was faster at H. japanicus community than others. Ca, Na, Mg, K, P, C, N and H contents reduced to around $40{\sim}80%$ of original. However, Na concentration increased up to $407{\sim}584%$ at 100 days and decreased to $248{\sim}498%$ at the end of the experiment. Decomposition rates were similar between 1 mm and 5mm mesh size litterbags and this implies that plant litters in studied areas decomposed mainly by microbes rather than small animals. This study revealed that the fast growth of H. japonicus was resulted from fast decomposition in part: positive feedback of nutrient cycling.

• Journal of The Korean Association For Science Education
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• v.27 no.2
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• pp.144-152
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• 2007

In this study, high school science teachers' and students' various conceptions related to osmosis phenomena were compared with and analyzed in relation to the content of science textbooks used in high school science classrooms and college science courses. The questionnaires developed by the researchers were administered to science teachers and students. Differences can be found between the explanations of science textbooks on osmotic pressure and semi-permeable membranes. Many science teachers and students thought of osmotic pressure as 'membrane pressure occurred by the movement of a solvent'. Moreover, the types of teachers of semi-permeable membranes were similar regardless of their academic majors. Many of the teachers thought of a semi-permeable membrane as a membrane that 'passes small-size particles'; however, many students thought of this type of membrane as being 'selectively permeable'. Also, the salt-pickling cabbage phenomenon seemed to cause significant confusion to science teachers and students. These study results show that teachers and students possess various conceptions related to the osmosis phenomena. These different conceptions related to osmosis phenomena might cause confusion and diverse conceptions including misconceptions among teachers and students.

• Journal of The Korean Association For Science Education
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• v.17 no.4
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• pp.405-413
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• 1997

High school common science is introduced by the sixth national curriculum. It consists of physics, chemistry, biology and earth science like the secondary school science. In this paper, textbooks are analyzed by the science teachers and the status of the present teaching and learning methods is reported. The detailed results are as follows; 1. Almost high school teachers choose textbook that included little the STS material. More than two teachers are teaching the high school common science and when they are chosen, they are independent with their major. 2. According to the national curriculum, they evaluated the textbooks as it is below the middle level. This evaluations are not dependent on teachers' comparement and textbook's class except the several matters based on STS (science-technology-society). 3. The teacher teaching the high school common science thought that teaching the textbook in school is worse than analysizing it. they must have emphasised on learning of inquire method than system of knowledge, introduction to material connected with real life and STS in the high school common science.

• Plant Resources
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• v.3 no.2
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• pp.152-162
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• 2000

This study was performed to investigate the resources flora of Mt. ManRoi(611.7m; 37$^{\circ}$51'N, 127$^{\circ}$ 20'E), during April 1995 to September 1998. The vascular plants, which were collected from the mountain were composed of all 382 taxa including cultivated species, and classified into 1 phylum, 4 classes, 34 orders, 87 families, 254 genera, 323 species, 1 subspecies,55 varieties and 4 forms. There were not rare and endangered species, while 7 taxa of Korean endemic plants, that is, Tricyitis dilatata, Clematis trichotoma, Deutzia coreana, Spiraea prunifolia var, simpliciflora, Forsythia koreana, Weigela subsessilis and Patrinia sanicalaefalia were distributed in this mountain. The vegetation of this investigated area is regarded as the boundary of the temperate middle part and temperate southern part in floral zone of the Korean Peninsula.