• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.701-710
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• 2002

Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method To establish vitrification method for bovine oocytes, mature bovine oocytes were vitrified by microdrop (MD) or straw (Straw) method and the viability of vitrified oocytes with or without cumulus cells (CC) were examined by several methods; a) parthenogenetic activation; b) pronuclear formation after in vitro fertilization (IVF); and c) embryonic development after IVF. The survival rate of vitrified oocytes by MD was significantly higher than by Straw (92.50 vs. 74.19%, p<0.05). Most of the oocytes survived from vitrification using the MD methods. Cleavage and blastocyst development of parthenogenetically activated oocytes were higher in MD (45.05% and 10.81%, respectively; p<0.05)) than those in Straw method (27.17% and 6.52%, respectively; p<0.05). Male and female pronuclear formation of vitrified-thawed oocytes with or without cumulus cells (CC) after IVF were examined, respectively. The survival rate of vitrified oocytes by MD without CC was no difference between MD and Straw (80.368.14% vs. 67.31%). Normal fertilization (2PN) rates were not different among groups (Fresh; 54.55% vs. MD; 42.22% vs. Straw; 37.14%, p>0.05). While no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 32.47% vs. MD; 57.78% and Straw 62.86%, p<0.05). The polyspermy (3PN) was appeared in the fresh (12.99%), but no appeared in the vitrified-thawed groups. In the without CC, normal fertilization (2PN) rates were significantly different between fresh and vitrified-thawed oocytes (Fresh; 59.38% vs. MD; 17.31% and Straw; 30.43%, p<0.05). Moreover, no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 23.44% vs. MD; 73.08% and Straw 58.70%, p<0.05). The polyspermy (3PN, >4PN) was appeared not only fresh but vitrified-thawed groups. After IVF, two-cell developmental rates of vitrified oocytes with CC by MD and Straw were significantly low compared to fresh oocytes (Fresh; 81.76% vs. MD; 22.22% and Straw; 11.36%, p<0.05). Blastocyst developmental rates of vitrified oocytes also were significantly low compared to fresh oocytes (Fresh; 28.38 vs. MD; 1.71% and Straw 0%, p<0.05). In the without CC, two-cell developmental rates were no difference between Fresh and MD (27.59% vs. 19.25%, p<0.05), while blastocyst rates were difference between Fresh and MD or Straw (4.31% vs. 0.62% and 0%, respectively; p<0.05). In conclusion, the results indicate that the vitrified bovine oocytes have the ability to develop to the blastocyst stage after IVF.

• Journal of Korean Society of Forest Science
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• v.51 no.1
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• pp.22-35
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• 1981

This study was designed to know difference in degree of dehardening and rehardening respectively by artificial high and low temperature treatments among different clonal seedlings and seedlings from different seed sources of Cryptomeria japonica which have been grown under the cold areas in Japan and Korea. High temperature treatment was done with 15 to $20^{\circ}C$ under 100% relative humidity for one to nine days and low temperature treatment was carried with $-7^{\circ}C$ for one to three days. Occasionaly, high temperature treatment was combined and followed by low temperature treatment. The ability of stem section to delay dehardening by high temperature treatment and/or to hasten rehardening by low temperature treatment was used as an indicator of adaptability under extreme temperature fluctuation in nature. Clones and seedlings from different seed sources which showed greater freezing resistance than others after artificial high and/or low temperature treatments were selected over two to three time periods: early winter, mid winter and early spring in 1977 to 1980. These were Seoul #7, and #9, Namboo #3, and #4, Sung-Kang #11, Chung-Sam #8 and Huek-Suk #9. These selected seedlings might have survival advantage to withstand early and late frost damage, especially the critical frost damage of the basal stem, since it was known to be induced by lowering freezing resistance of the basal part when exposed to the high temperature near the ground during the day. Large variation in freezing resistance and degree of dehardening and rehardening was found among clonal or seed sources and among individuals within a seed source, but was not related to the difference in climatic conditions where the parent trees was selected. These indicated the possibility of future breeding work for more cold resistant family of Cryptomeria japonica.

• Journal of fish pathology
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• v.23 no.1
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• pp.69-83
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• 2010

This study was aimed to investigate the effects of injection of garlic, Allium sativum, extract and immersion in garlic juice on the nonspecific immunity and the resistance against the artificial infection of Streptococcus iniae and Edwardsiella tarda of the olive flounder, Paralichthys olivaceus. The nonspecific immune mechanisms were assessed in terms of lysozyme activity, nitroblue-tetrazolium (NBT) assay and superoxide dismutase (SOD) activity etc. Relative percent survival (RPS) was assessed by the challenge with S. iniae BS10 or E. tarda KE-1. Almost of the garlic extract injected groups showed the enhanced level of the tested nonspecific immune factors. In the challenge test with S. iniae and E. tarda, RPS of 5% garlic extract pre-injected group was much higher than that of any other tested groups, respectively. Almost of the garlic juice immersion tested groups exhibited strengthened nonspecific immune defence factors, lysozyme activity, the number of lymphocytes and neutrophils, NBT reduction and SOD activity in kidney. In the challenge with S. iniae and E. tarda, RPS in the 0.25 g/L of garlic juice immersed group was much higher than any other tested groups, respectively. The results suggest that the garlic extract and juice would be effective to enhance the nonspecific immunity and protective ability of olive flounder against fish disease such as S. iniae and E. tarda.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.95-106
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• 1988

Specific or non-specific cytolytic processes of free-living amoebae causing meningoencephalitls have been emphasized and the cytolytic ability related to hydrolases in Entantoeba sp. and Naegleria sp. has also been reported since the latter half of 1970's. However, no information on hydrolase activities in Acanthamoeba sp. is available. Hydrolases in Acanthamoeba culbertsoni, a pathogenic species of free-living amoebae, were assayed and compared with those in a non-pathogenic species, A. royreba. Pathogenicity of these two species was confirmed through experimental infection to BALB/c mice. Hydrolase activities and cytotoxic effects between pathogenic and non.pathogenic species were compared in the trophozoites cultured in CGV media and in CHO cell line, respectively. The results are summarized as follows: 1. The mice infected with A. culbertseni were all dead 15 days after nasal inoculation, and the mean survival time was 8.5 days. Also the mice infected with this pathogenic species manifested typical meningoencephalitis, whereas the mice infected with A. royreba did not. 2. Hydrolases detected both in the cell extracts and culture media were acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$, neutral proteinase and acid proteinase, all of which were detected with remarkably higher rate in A. culbertsoni than in A. royreba. 3. A. cuzbertsoni revealed strong cytotoxicity for the target CHO cells, whereas A. royreba did not show any specific cytotoxicity. About 80% of the target cells mixed with A. culbertsoni were dead 48 hours after cultivation, and more than 95% of the target cells were dead 72 hours after cultivation. 4. Hydrolase activities in A. culbertsoni cultured with the target cell line were assayed according to the culture time. The activities of acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$ and acid proteinase in this pathogenic amoeba were detected higher in amoeba extracts than in culture media up to 120 hours after cultivation, but after 120 hours of cultivation those activities were detected higher in culture media than in the amoeba Iysates. Neutral proteinase activity in A. culbertsoni increased more in EBSS medium than in the Iysate specimens although the activity in the extracts was generally steady according to the cultivation time. Summarizing the above results, it is concluded that there were differences in hydrolase activities between Pathogenic A. culbertsoni and non-pathogenic A. royreba, and that some hydrolase activities were detected remarkably higher in A. culbertsoni which revealed strong cytotoxicity to the target CHO cell line.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.121-139
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• 2014

Predicting corporate failure has been an important topic in accounting and finance. The costs associated with bankruptcy are high, so the accuracy of bankruptcy prediction is greatly important for financial institutions. Lots of researchers have dealt with the topic associated with bankruptcy prediction in the past three decades. The current research attempts to use ensemble models for improving the performance of bankruptcy prediction. Ensemble classification is to combine individually trained classifiers in order to gain more accurate prediction than individual models. Ensemble techniques are shown to be very useful for improving the generalization ability of the classifier. Bagging is the most commonly used methods for constructing ensemble classifiers. In bagging, the different training data subsets are randomly drawn with replacement from the original training dataset. Base classifiers are trained on the different bootstrap samples. Instance selection is to select critical instances while deleting and removing irrelevant and harmful instances from the original set. Instance selection and bagging are quite well known in data mining. However, few studies have dealt with the integration of instance selection and bagging. This study proposes an improved bagging ensemble based on instance selection using genetic algorithms (GA) for improving the performance of SVM. GA is an efficient optimization procedure based on the theory of natural selection and evolution. GA uses the idea of survival of the fittest by progressively accepting better solutions to the problems. GA searches by maintaining a population of solutions from which better solutions are created rather than making incremental changes to a single solution to the problem. The initial solution population is generated randomly and evolves into the next generation by genetic operators such as selection, crossover and mutation. The solutions coded by strings are evaluated by the fitness function. The proposed model consists of two phases: GA based Instance Selection and Instance based Bagging. In the first phase, GA is used to select optimal instance subset that is used as input data of bagging model. In this study, the chromosome is encoded as a form of binary string for the instance subset. In this phase, the population size was set to 100 while maximum number of generations was set to 150. We set the crossover rate and mutation rate to 0.7 and 0.1 respectively. We used the prediction accuracy of model as the fitness function of GA. SVM model is trained on training data set using the selected instance subset. The prediction accuracy of SVM model over test data set is used as fitness value in order to avoid overfitting. In the second phase, we used the optimal instance subset selected in the first phase as input data of bagging model. We used SVM model as base classifier for bagging ensemble. The majority voting scheme was used as a combining method in this study. This study applies the proposed model to the bankruptcy prediction problem using a real data set from Korean companies. The research data used in this study contains 1832 externally non-audited firms which filed for bankruptcy (916 cases) and non-bankruptcy (916 cases). Financial ratios categorized as stability, profitability, growth, activity and cash flow were investigated through literature review and basic statistical methods and we selected 8 financial ratios as the final input variables. We separated the whole data into three subsets as training, test and validation data set. In this study, we compared the proposed model with several comparative models including the simple individual SVM model, the simple bagging model and the instance selection based SVM model. The McNemar tests were used to examine whether the proposed model significantly outperforms the other models. The experimental results show that the proposed model outperforms the other models.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.120-128
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• 2009

Purpose: Early detection of recurrence is an important factor for long term survival of patients with colorectal cancer. Measurement of serum levels of CEA, CA 19-9, CT and PET/CT has been commonly used in the postoperative surveillance of colorectal cancer. The purpose of this study was to compare the diagnostic ability of PET/CT, tumor marker and CT for recurrence in colorectal cancer patients after treatment. Materials and Methods: F-18 FDG PET/CT imaging was performed in 189 colorectal cancer patients who underwent curative surgical resection and/or chemotherapy. Measurement of serum levels of CEA, CA 19-9 and CT imaging were performed within 2 months of PET/CT examination. Final diagnosis of recurrence was made by biopsy, radiologic studies or clinical follow-up for 6 months after each study. Results: Overall sensitivity, specificity of PET/CT was 94.7%, 91.1%, while those of serum CEA were 44.7% and 97.3%, respectively. Sensitivity and specificity were 94.2%, 90.4% for PET/CT and better than those of combined CEA and CA 19-9 measurement(52.1%, 88.5%) in 174 patients measured available both CEA and CA 19-9 data. In 115 patients with both tumor markers and CT images available, PET/CT showed similar sensitivity but higher specificity(92.9%, 91.3%) compared to combination of tumor markers and CT images(92.9%, 74.1%). Conclusion: PET/CT was superior for detection of recurred colorectal cancer patients compared with both CEA, CA 19-9, and even with combination of both tumor markers and CT. Therefore PET/CT could be used as a routine surveillance examination to detect recurrence or metastasis of colorectal cancer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.181-194
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• 2002

Parasitism is a one-sided relationship between two organisms in which one benefits at the expense of the other. Parasitic dinoflagellates, particularly species of Amoebophrya, have long been thought to be a potential biological agent for controlling harmful algal bloom(HAB). Amoebophrya infections have been reported for over 40 species representing more than 24 dinoflagellate genera including a few toxic species. Parasitic dinoflagellates Amoebophrya spp. have a relatively simple life cycle consisting of an infective dispersal stage (dinospore), an intracellular growth stage(trophont), and an extracellular reproductive stage(vermiform). Biology of dinospores such as infectivity, survival, and ability to successfully infect host cells differs among dinoflagellate host-parasite systems. There are growing reports that Amoebophrya spp.(previously, collectively known as Amoebophrya ceratii) exhibit the strong host specificity and would be a species complex composed of several host-specific taxa, based on the marked differences in host-parasite biology, cross infection, and molecular genetic data. Dinoflagellates become reproductively incompetent and are eventually killed by the parasite once infected. During the infection cycle of the parasite, the infected host exhibits ecophysiologically different patterns from those of uninfected host in various ways. Photosynthetic performance in autotrophic dinoflagellates can be significantly altered following infection by parasitic dinoflagellate Amoebophrya, with the magnitude of the effects over the infection cycle of the parasite depending on the site of infection. Parasitism by the parasitic dinoflagellate Amoebophrya could have significant impacts on host behavior such as diel vertical migration. Parasitic dinoflagellates may not only stimulate rapid cycling of dissolved organic materials and/or trace metals but also would repackage the relatively large sized host biomass into a number of smaller dinospores, thereby leading to better retention of host's material and energy within the microbial loop. To better understand the roles of parasites in plankton ecology and harmful algal dynamics, further research on a variety of dinoflagellate host-parasite systems is needed.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1158-1164
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• 2008

Purpose : To investigate the discriminative ability of pediatric index of mortality 2 (PIM2) and pediatric risk of mortality III (PRISM III) in predicting mortality in children admitted into the intensive care unit (ICU). Methods : We retrospectively analyzed variables of PIM2 and PRISM III based on medical records with children cared for in a single hospital ICU from January 2003 to December 2007. Exclusions were children who died within 2 h of admission into ICU or hopeless discharge. We used Students t test and ANOVA for general characteristics and for correlation between survivors and non-survivors for variables of PIM2 and PRISM III. In addition, we performed multiple logistic regression analysis for Hosmer-Lemeshow goodness-of-fit, receiver operating characteristic curve (ROC) for discrimination, and calculated standardized mortality ratio (SMR) for estimation of prediction. Results : We collected 193 medical records but analyzed 190 events because three children died within 2 h of ICU admission. The variables of PIM2 correlated with survival, except for the presence of post-procedure and low risk. In PRISM III, there was a significant correlation for cardiovascular/neurologic signs, arterial blood gas analysis but not for biochemical and hematologic data. Discriminatory performance by ROC showed an area under the curve 0.858 (95% confidence interval; 0.779-0.938) for PIM2, 0.798 (95% CI; 0.686-0.891) for PRISM III, respectively. Further, SMR was calculated approximately as 1 for the 2 systems, and multiple logistic regression analysis showed ${\chi}^2(13)=14.986$, P=0.308 for PIM2, ${\chi}^2(13)=12.899$, P=0.456 for PRISM III in Hosmer-Lemeshow goodness-of-fit. However, PIM2 was significant for PRISM III in the likelihood ratio test (${\chi}^2(4)=55.3$, P<0.01). Conclusion : We identified two acceptable scoring systems (PRISM III, PIM2) for the prediction of mortality in children admitted into the ICU. PIM2 was more accurate and had a better fit than PRISM III on the model tested.

• Journal of fish pathology
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• v.22 no.1
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• pp.35-44
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• 2009

The potential pathogenicity of Vibrio splendidus biovar II, which was isolated from triploid larvae of pacific oyster with bacillary necrosis and fish pathogenic V. anguillarum were investigated. The 5-day-old larvae infected with V. splendidus biovar II at the dose of $1.81{\times}10^{4}$ CFU/$m\ell$ started to die within 8 hours after exposure and the mortality were reached to 100% in 16 hours. However, $1.13{\times}10^{4-5}$ CFU/$m\ell$ of V. anguillarum caused 5.5-20% mortality of the larvae after 24 hours. The 10-day-old larvae infected with V. splendidus biovar II at the dose of $5.0{\times}10^{5}$ CFU/$m\ell$ showed mortality from 8 hours after challenge and led to a marked mortality of 90.47% after 24 hours. But V. anguillarum at doses of $5.08{\times}10^{3-6}$ CFU/$m\ell$ did not show mortality in the 10-day-old larvae. Therefore V. splendidus biovar II exhibited stronger virulence in 5-day-old larvae than 10-day-old and young oyster. Changes in the concentration of Vibrio in sea water showed that V. anguillarum decreased from $1.13{\times}10^{5}$ CFU/$m\ell$ to 1.7${\times}$105 CFU/$m\ell$ and V. splendidus biovar II increased from $1.81{\times}10^{4}$ CFU/$m\ell$ to $1.7{\times}10^{7}$ CFU/$m\ell$. This strong survival ability of V. splendidus biovar II in seawater was thought as one of the virulence factors against oyster larvae. The mortalities of 5-day-old and 10-day-old oyster larvae were decreased by addition of 30 $\mu{g}/m\ell$ of antibacterial agent(oxytetracycline or streptomycin). These results suggest that bacillary necrosis by V. splendidus biovar II can be occurred in oyster larvae in Korea. And virulence of V. splendidus biovar II is stronger than that of V. anguillarum in oyster larvae causing significant mortality at the density of $10^{4}$ CFU/$m\ell$.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.111-119
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• 2010

Salmonella spp. are one of major pathogens for zoonosis in worldwide, and can replicate within host cells and generally cause enterocolitis and foodborne poisoning which represents a considerable public health burden. The present study was designated to investigate the safty for host cells, antibacterial effects of Saururus chinensis Baill water extract (SCWE) on pure culture and infection with Salmonella enterica serovar Typhimurium (S. typhimurium) in murine derived macrophage RAW 264.7 cells. The different treatment of SCWE concentration (1, 10 or $100{\mu}g/ml$) did not show any cytotoxic effect to RAW 264.7 cells for 24 h incubation. In determination of antibacterial activity of SCWE against S. typhimurium, bacterial viability was markedly decreased compared to SCWE-untreated control. In RAW 264.7 cells, SCWE significantly induced morphological change (p<0.05). In infection assay of S. typhimurium in RAW 264.7 cells pretreated with $100{\mu}g/ml$ of SCWE, which are non-cytotoxic concentration, bacterial uptake ability of macrophage was increased corresponding with morphological change, whereas bacterial survival rates within macrophage was markedly reduced comparing to that of SCWE-untreated control. Furthermore, nitric oxide (NO) production in SCWE-treated cells was slightly decreased until 24 h post infection. Taken together, these findings demonstrated that SCWE have the antibacterial activity for S. typhimurium and the protective effects against S. typhimurium infection through activating murine macrophage independent on NO, suggesting that SCWE were beneficial on the disease caused by intracellularly replicating pathogens as a safe alternatives of conventional chemotherapies.