• Korean Journal of Weed Science
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• v.16 no.1
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• pp.21-27
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• 1996

This experiment was conducted to find out an effective propagation method for reed(Phragmites communis Trin.), ensuring a continuous herbicide screening for reed control. Reed propagation methods were compared under a greenhouse condition using tour different materials; seeds, rhizomes, depressed stolons of P. japonica Steud., and stem cuttings. Although reed seeds were easy to harvest and store, their germination rate(${\leq}$5%) was very low and seedling growth from the seeds was slow. Rhizomes were difficult to harvest and their harvest time was limited from November to March. Furthermore, reed propagation using rhizomes had problems of a relatively low germination rate(46%), no uniformity in size and shape, individual differences at the early stage of growth, and difficulties in material storage. Rate of reed growth from rhizomes was higher in commercial soil mix(Boo Nong soil) than in sand or in sand+upland soil(1:1). Depressed stolons of P. japonica had a moderate germination rate(65%) and were relatively easy to harvest. However, their harvest time was limited only from August to September. Propagation method using stem cuttings had several advantages over the above methods using other materials. Reed plants could uniformly be propagated from the stem cuttings with a relatively high germination rate(75%). Stem cuttings of central nodes showed a higher germination rate compared to those of upper or lower nodes. Stem cuttings from the field should be used immediately after harvest, since their germination rate decreased rapidly when they were stored under a wet- or a dry-refrigerated condition. Furthermore, the germination of stem cuttings tended to decrease when they were collected from the field after August. This indicates that there is a limitation of harvest time for stem cuttings. However, a year-round propagation of reed using stem cuttings is possible if parent plants are grown in a greenhouse, and thus herbicide screening for reed control could continuously be performed.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.2
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• pp.95-106
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• 2007

Objective: We previously identified differentially expressed genes (DEGs) between germinal vesicle (GV) and metaphase II (MII) mouse oocyte. The present study was accomplished as a preliminary study to elucidate the role of ribose 5-phosphate isomerase A (Rpia), the essential enzyme of the pentose phosphate pathway (PPP), in oocyte maturation. We observed expression of Rpia in the mouse and porcine oocytes. Methods: Expression pattern of the 11 MII-selective DEGs in various tissues was evaluated using RT-PCR and selected 4 genes highly expressed in the ovary. According to the oocyte-selective expression profile, we selected Rpia as a target for this study. We identified the porcine Rpia sequence using EST clustering technique, since it is not yet registered in public databases. Results: The extended porcine Rpia nucleotide sequence was submitted and registered to GenBank (accession number EF213106). We prepared primers for porcine Rpia according to this sequence. In contrast to the oocyte-specific expression in the mouse, Rpia was expressed in porcine cumulus and granulosa cells as well as in oocytes. Conclusion: This is the first report on the characterization of the Rpia gene in the mouse and porcine ovarian cells. Results of the present study suggest that the mouse and porcine COCs employ different mechanism of glucose metabolism. Therefore, the different metabolic pathways during in vitro oocyte maturation (IVM) in different species may lead different maturation rates. It is required to study further regarding the role of Rpia in glucose metabolism of oocytes and follicular cell fore exploring the regulatory mechanism of oocyte maturation as well as for finding the finest culture conditions for in vitro maturation.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.33-39
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• 2006

Purpose : Neonatal hydronephrosis is diagnosed with an incidence of 4.5-7% of pregnancies. Recently, early detection of neonatal hydroneprosis with antenatal ultrasonography has be-come possible. But consensus about its management has not been reached, especially concerning surgical intervention. The purpose of this study is to analyze the natural course of neonatal hydronephrosis and to determine the guideline of surgical intervention and follow up study. Methods : Sixty nine hydronephrotic kidneys were confirmed from April 2001 to April 2005. All cases were rechecked by ultrasonography once at least and had a minimum follow-up of 6 months. We classified the patients into 4 groups according to the anterior posterior pelvic diameter(APPD) on perinatal ultrasonography. Ultrasonography to measure the APPD diameter and Society for Fetal Urology(SFU) grade, $^{99m}Tc-MAG3$ scan were done to a set protocol. Pyeloplasty was peformed according to the protocol. Results : Pyeloplasty was not needed in most cases where the APPD was below 10 mm and where the SFU grade were less than grade 3. Many cases with APPD 10 mm above or SFU grade III above had undergone pyeloplasty. We found a correlation between obstruction grade on MAG3 scan and whether surgery was performed or not. Conclusion : If APPD is above 10 mm, SFU grade is above grade 3 or urinary tract obstruction is suspected by MAG3 scan, pyeloplasty must be considered. In cases where APPD is below 10mm and SFU grade is less than grade 3, we can observe the natural course of neonatal hydronephrosis with consecutive follow-up. (J Korean Soc Pediatr Nephrol 2006;10:33-39)

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.559-567
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• 2012

The storage quality of ready-to-eat Campbell table grapes which were packaged under modified atmospheres was investigated in order to examine the effect of high $O_2$ and $CO_2$ on the fruit. Fresh table grapes with 10-15 berries were packed into polypropylene (PP) trays and were top-sealed with polythylene terephthalate/PP film. The initial gas compositions inside the packages were air, 20% $O_2$/10% $CO_2$/70% $N_2$, and 40% $O_2$/60% $N_2$. Sealed packages with low density polyethylene film bags and perforated PP trays were also used as a further treatment and control, respectively. The quality attributes were assessed during storage at $5^{\circ}C$ for 28 days. Fruit packaged in high $CO_2$ concentration showed the lowest viable cell counts of inherent microorganisms among all samples, although they suffered from severe off-flavors. High levels of $O_2$ significantly lowered flesh weight loss and maintained the flavor of grape. In an overall sensory aspect, the high $O_2$ and $CO_2$ packages exhibited greater scores than the air and control at the end of the storage period. Other quality attributes showed no significant differences among treatments. Results suggest that packaging with an appropriate combination of high $O_2$ and $CO_2$ can be used as an effective processing treatment for improvement of the storability of ready-to-eat table grapes.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.825-830
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• 2009

Pharmaceutical compounds enter the water environment through the diverse pathways. Because their concentration in the water environment was frequently detected in the level of ppt to ppb, the monitoring system should be optimized as much as possible for finding appropriate management policies and technical solutions. One Factor At a Time (OFAT) approach approximating the response with a single variable has been preferred for the optimization of LC-MS/MS operational conditions. However, it is common that variables in analytical instruments are interdependent. Therefore, the best condition could be found by using the statistical optimization method changing multiple variables at a time. In this research, response surface analysis (RSA) was applied to the LC-MS/MS analysis of emerging antibiotic compound, sulfamethoxazole, for the best sensitivity. In the screening test, fragmentation energy and collision voltage were selected as independent variables. They were changed simultaneously for the statistical optimization and a polynomial equation was fit to the data set. The correlation coefficient, $R^2$ valuerepresented 0.9947 and the error between the predicted and observed value showed only 3.41% at the random condition, fragmentation energy of 60 and collision voltage of 17 eV. Therefore, it was concluded that the model derived by RSA successfully predict the response. The optimal conditions identified by the model were fragmentation energy of 116.6 and collision voltage of 10.9 eV. This RSA can be extensively utilized for optimizing conditions of solid-phase extraction and liquid chromatography.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.261-271
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• 2015

Toxicity results of metals, nanoparticles (NPs), and soils contaminated with metals were introduced on this review. Following methods were used: seed germination, bioluminescence, enzyme activity, and mutation. In general, different sensitivities were observed, depending on types of bioassays and pollutants. Among tested seeds, sensitivities of Lactucus and Raphanus were greater than others. Of single metal exposure, effect by As(III) was greater than others, and high revertant mutation ratio (5.1) was observed at 1 mg/L arsenite, indicating high mutagenicity. No general pattern was observed on the effect of metal mixture, but synergistic effect was observed with seeds. In case of soils, no correlation was observed between total metal contents and toxicity. Toxicity of NPs was observed as follows: CuO > ZnO > NiO > $TiO_2$, $Fe_2O_3$, $Co_3O_4$. Especially, no considerable effects were observed by $TiO_2$, $Fe_2O_3$, and $Co_3O_4$ under tested concentration (max. 1,000 mg/L). The evaluation results of interactive toxic effects using various bioassays may comprise a useful tool for the bioassessment of various environmental pollutants.

• Journal of Wetlands Research
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• v.15 no.2
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• pp.251-264
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• 2013

There are some factors affecting the shorebirds in selecting a coastal inland roost site where they have to stay during the high tide when the entire intertidal zone is covered with water. We investigated eight species (Eastern Curlews Numenius madagascariensis, Green Shanks Tringa nebularia, Bar-tailed Godwits Limosa lapponica, Grey Plovers Pluvialis squatarola, Dunlins Calidris alpine, Whimbrels Numenius phaeopus, Eurasian Curlews Numenius arquata and Terek Sandpipers Xenus cinereus) to identify the spatial and temporal variability in coastal inland roost use in the area and the factors influencing the use. We considered the area and length of the standing water in the roost site, temperature, wind speed, the time of migration and the intensity of disturbance. As a result, number of individuals and type of species using the roost site varied across spatial and temporal scales. And the factors affecting the roost use was species-specific. The roost site of the study area was a closed shrimp farm however, it has been converted to a Salicornia herbacea, a salt marsh plant, farm recently. In a situation where coastal inland roost site is needed, we hereby describe a resolution for the juxtaposition of shorebirds and farming.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.17 no.1
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• pp.13-17
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• 2011

There is a need in food industry to store minimally processed garlic for long time to have it be used just at the time of demand for final product processing. Optimal modified atmosphere packaging is expected to slow down the quality change extending its storage life. In order to find optimal packaging conditions, plastic films of different gas permeability properties (low density polyethylene (LDPE) $30{\mu}m$, polyolefin $50{\mu}m$ (PD 900), polyolefin $20{\mu}m$ (PD 941)) were used for packaging 400 g of minimally processed garlic. Perforated LDPE packages were prepared as control. The packaged products were stored at $1{\pm}1^{\circ}C$ for 52 days. Package treatments were compared in weight loss, decay, surface color, hardness and soluble solid content. While control package had normal atmosphere of air, LDPE, PD 900 and PD 941 packages attained internal concentration of $O_2$ 4.6% / $CO_2$ 12%, $O_2$ 0.9% / $CO_2$ 21% and $O_2$ 0.5% / $CO_2$ 13% after 45 days, respectively. Control packaging had rapid weight loss with high mold decay and great surface color change in 45 days. In PD 900 film packages of lowest gas permeability, the fresh-cut garlic could be stored without mold decay for 52 days. Except control packaging, there were no significant differences in surface color, hardness and soluble solid content among package treatments.

• Journal of the Korean Society for information Management
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• v.31 no.3
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• pp.271-291
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• 2014

The purpose of this study is to analyze undergraduate nursing students' electronic document use and reading behavior. To do this, a survey questionnaire was collected from 509 respondents who experienced reading behavior for the last semester. The results of this study show that nursing students' preference of electronic documents is higher than that of printed documents in general. They also prefer electronic documents to printed documents when they want to keep documents. Of respondents, about 94% or higher spent 30mins or more to find information and the main source to find information is 'Naver' search engine as the highest information source, and the place to access information is 'Home' as their highest information access location. In particular, the preference of the document 'on the move' is electronic documents and the main reason includes convenience and easiness to access and move the documents. The findings of this study expect to facilitate the understanding of undergraduate nursing students electronic document use and reading behavior so that it can be used to design and develop medical digital library services and tools more effectively and efficiently in medical area in the future. Furthermore, it expects to provide useful data in promoting user services in digital library in a whole.

• Journal of the Korean earth science society
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• v.25 no.4
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• pp.205-213
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• 2004

The purpose of this study was to design the coaching strategies for the problem based learning and examine 'the problem situation' to analyze the process of learning as it applies to the students' perception on problem based learning. The steps of this model were as follows: 1) presentation of the problem situation 2) confrontation of the problem 3) know/ need to know 4) definition of the problem statement 5) collection and sharing of information 6)generation of possible solutions 7) assessment of the best fit of solutions 8) presentation of the solution. Problem-based learning steps and coaching strategies were designed and implemented to 2nd grade high school students for the environment teaching unit. The results demonstrated that group discussion in the know/need to know step was most helpful for students to review what they know and generate solutions. At first students tend to state problems widely but through repeated group discussions they gradually clarified the problems. In the students' personal reflection notes and perception questionnaire of problem-based learning, many students especially showed difficulties in defining the problem statement. In contrast they participated actively in the learning process and express their opinions enthusiastically. Therefore, this study suggests that developing problem situation based on real context is of great importance for implementing a problem based teaming model continuously.