• The Korean Journal of Physiology and Pharmacology
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• v.19 no.5
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• pp.451-460
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• 2015

Sirtuin 1 (SIRT1) is a mammalian $NAD^+$-dependent protein deacetylase that regulates cellular metabolism and inflammatory response. The organ-specific deletion of SIRT1 induces local inflammation and insulin resistance in dietary and genetic obesity. Macrophage-mediated inflammation contributes to insulin resistance and metabolic syndrome, however, the macrophage-specific SIRT1 function in the context of obesity is largely unknown. C57/BL6 wild type (WT) or myeloid-specific SIRT1 knockout (KO) mice were fed a high-fat diet (HFD) or normal diet (ND) for 12 weeks. Metabolic parameters and markers of hepatic steatosis and inflammation in liver were compared in WT and KO mice. SIRT1 deletion enhanced HFD-induced changes on body and liver weight gain, and increased glucose and insulin resistance. In liver, SIRT1 deletion increased the acetylation, and enhanced HFD-induced nuclear translocation of nuclear factor kappa B (NF-${\kappa}B$), hepatic inflammation and macrophage infiltration. HFD-fed KO mice showed severe hepatic steatosis by activating lipogenic pathway through sterol regulatory element-binding protein 1 (SREBP-1), and hepatic fibrogenesis, as indicated by induction of connective tissue growth factor (CTGF), alpha-smooth muscle actin (${\alpha}$-SMA), and collagen secretion. Myeloid-specific deletion of SIRT1 stimulates obesity-induced inflammation and increases the risk of hepatic fibrosis. Targeted induction of macrophage SIRT1 may be a good therapy for alleviating inflammation-associated metabolic syndrome.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.83-89
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• 2006

Cellular functions are carried out by a concerted action of biochemical pathways whose components have genetic interactions. Abnormalities in the activity of the genes that constitute or modulate these pathways frequently have oncogenic implications. Therefore, identifying the upstream regulatory genes for major biochemical pathways and defining their roles in carcinogenesis can have important consequences in establishing an effective target-oriented antitumor strategy We have analyzed the gene expression profiles of human liver cancer samples using cDNA microarray chips enriched in liver and/or stomach-expressed cDNA elements, and identified groups of genes that can tell tumors from non-tumors or normal liver, or classify tumors according to clinical parameters such as tumor grade, age, and inflammation grade. We also set up a high-throughput cell-based assay system (cell chip) that can monitor the activity of major biochemical pathways through a reporter assay. Then, we applied the cell chip platform for the analysis of the HCC-associated genes discovered from transcriptome profiling, and found a number of cancer marker genes having a potential of modulating the activity of cancer-related biochemical pathways such as E2F, TCF, p53, Stat, Smad, AP-1, c-Myc, HIF and NF-kB. Some of these marker genes were previously blown to modulate these pathways, while most of the others not. Upon a fast-track phenotype analysis, a subset of the genes showed increased colony forming abilities in soft agar and altered cell morphology or adherence characteristics in the presence of purified matrix proteins. We are currently analyzing these selected marker genes in more detail for their effects on various biological Processes and for Possible clinical roles in liver cancer development.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.28-44
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• 1998

This study was conducted to suggest the ecological restoration strategies for the disturbed landscapes by theoretical study. Especially, it is aimed to suggest three objectives for restoration by using native plants ; (1) prevention or reduction of wind and water erosion, (2) provision of food and cover for variety of animal species, (3) improvement of the visual or aesthetic quality of disturbed sites. The main results were summarized as follows. 1. Cooperation between restoration ecologists and restoration practitioners is needed to delineate a scientific approach to restoration ; (1) Being aware of published literature that describes similar work and/or establish general principles. (2) Preparedness to carry out proper experiments to test ideas. (3) Preparedness to monitor fundamental parameters in a restoration scheme. (4) Providing information about the behavior of species. (5) Publish results. 2. There are three models of succession in theories of plant succession. The tolerance and facilitation models were recommended to ecological restoration. The inhibition model applies in most secondary succession, but the actual species which are introduced first may inhibit the germination and growth of slower-growing species, or they may prevent the growth of other species whose propagules arrive later. 3. The objectives of erosion control, wildlife habitat provision, and visual quality improvement are not mutually exclusive. However, many revegetation practices in the past have emphasized one of these aspects at the expense of the others. 4. A native plant community can be the model of ecological restoration. By stylization/abstraction of native plant community, trying to learn the most essential characteristics of community types - environmental factors ; dominant, prevalent, and "visual essence" species composition - in order to use such information in restoration. 5. After developing mass/spaces plan, match plant communities to the mass/space plan. In utilizing community grouping, there needs aesthetic ability to understand design elements. 6. Several hydrophytes such as Pennisetum saccharifluous, Themeda triandra, Cirsium pendulum show relatively good germination rates. In case of mesophytes and xerophytes, Arundinella hina, Artemisia princeps, Oenothera odorata and legumes seem to have quick-germinating abilities at barren sites. Pinus thunbergii, Rhus chinensis, Evodia daniellii, Alnus firma and Albizzia julibrissin can be considered as "late succession" woody plants because they show low germinating rates and slow growing habitat. 7. The seeds used for restoration should be collected within a certain radius of where it will be planted. Consideration in genetic issues in the collection and use of germplasm can increase the odds for successful restoration efforts. 8. The useful model in the "drift" pattern occurs so abundantly in naturally evolving landscapes. As one species diminishes in density, a second or third species are increased. Thus, dynamic interactions between species are created. Careful using of "drift phenomenon" in planting was recommended. 9. Virtually no stand of vegetation today is immune from the introduction and/or spreading of exotic species. Therefore, the perpetuation of a restored sites requires conscious monitoring and management. Thus, management would be the most important process in ecological restoration. 10. In order to keep the sites "natural", alternative management strategies would be applied in management ; Atenative management strategies are decelerating successional process, accelerating successional processes or modifying species composition. As management tools, mechanical, chemical, biological or environmental factor manipulation, e.g., fire could be used.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.253-261
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• 2007

Molecular and cultivation techniques were used to characterize the bacterial communities of biobead reactor biofilms in a sewage treatment plant to which an Aerated Up-Flow Biobead process was applied. With this biobead process, the monthly average values of various chemical parameters in the effluent were generally kept under the regulation limits of the effluent quality of the sewage treatment plant during the operation period. Most probable number (MPN) analysis revealed that the population of denitrifying bacteria was abundant in the biobead #1 reactor, denitrifying and nitrifying bacteria coexisted in the biobead #2 reactor, and nitrifying bacteria prevailed over denitrifying bacteria in the biobead #3 reactor. The results of the MPN test suggested that the biobead #2 reactor was a transition zone leading to acclimated nitrifying biofilms in the biobead #3 reactor. Phylogenetic analysis of 16S rDNA sequences cloned from biofilms showed that the biobead #1 reactor, which received a high organic loading rate, had much diverse microorganisms, whereas the biobead #2 and #3 reactors were dominated by the members of Proteobacteria. DGGE analysis with the ammonia monooxygenase (amoA) gene supported the observation from the MPN test that the biofilms of September were fully developed and specialized for nitrification in the biobead reactor #3. All of the DNA sequences of the amoA DGGE bands were very similar to the sequence of the amoA gene of Nitrosomonas species, the presence of which is typical in the biological aerated filters. The results of this study showed that organic and inorganic nutrients were efficiently removed by both denitrifying microbial populations in the anaerobic tank and heterotrophic and nitrifying bacterial biofilms well-formed in the three functional biobead reactors in the Aerated Up-Flow Biobead process.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.137-144
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• 2004

Algorithms for estimating breeding values on several categorical data by using latent variables with threshold conception were developed and showed. Thresholds on each categorical trait were estimated by Newton’s method via gradients and Hessian matrix. This algorithm was developed by way of expansion of bivariate analysis provided by Quaas(2001). Breeding values on latent variables of categorical traits and observations on linear traits were estimated by preconditioned conjugate gradient(PCG) method, which was known having a property of fast convergence. Example was shown by simulated data with two linear traits and a categorical trait with four categories(CE=calving ease) and a dichotomous trait(SB=Still Birth) in threshold animal mixed model(TAMM). Breeding value estimates in TAMM were compared to those in linear animal mixed model (LAMM). As results, correlation estimates of breeding values to parameters were 0.91${\sim}$0.92 on CE and 0.87${\sim}$0.89 on SB in TAMM and 0.72~0.84 on CE and 0.59~0.70 on SB in LAMM. As conclusion, PCG method for estimating breeding values on several categorical traits with linear traits were feasible in TAMM.

• Journal of Navigation and Port Research
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• v.39 no.6
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• pp.457-463
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• 2015

A gas turbine engine plays an important role as a prime mover that is used in the marine transportation field as well as the space/aviation and power plant fields. However, it has a complicated structure and there is a time delay element in the combustion process. Therefore, an elaborate mathematical model needs to be developed to control a gas turbine engine. In this study, a modeling technique for a gas generator, a PLA actuator, and a metering valve, which are major components of a gas turbine engine, is explained. In addition, sub-models are obtained at several operating points in a steady state based on the trial running data of a gas turbine engine, and a method for controlling the engine speed is proposed by designing an NPID controller for each sub-model. The proposed NPID controller uses three kinds of gains that are implemented with a nonlinear function. The parameters of the NPID controller are tuned using real-coded genetic algorithms in terms of minimizing the objective function. The validity of the proposed method is examined by applying to a gas turbine engine and by conducting a simulation.

• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.459-464
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• 2008

In this paper, we present the model-based fuzzy controller for container cranes which effectively performs set-point tracking control of trolley and anti-swaying control under system parameter and disturbance changes. The first part of this paper focuses on the development of Takagi-Sugeno (T-S) fuzzy modeling in a nonlinear container crane system. Parameters of the membership functions are adjusted by a RCGA to have same dynamic characteristics with nonlinear model of a container crane. In the second part, we present a design methodology of the model-based fuzzy controller. Sub-controllers are designed using LQ control theory for each subsystem in fuzzy model and then the proposed controller is performed with the combination of these sub-controllers by fuzzy IF-THEN rules. In the results of simulation, the fuzzy model showed almost similar dynamic characteristics compared to the outputs of the nonlinear container crane model. Also, the model-based fuzzy controller showed not only the fast settling time for the change in parameter and disturbance, but also stable and robust control performances without any steady-state error.

• Animal Bioscience
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• v.34 no.12
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• pp.1886-1894
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• 2021

Objective: Growth hormone (GH) and insulin-like growth factor I (IGF-I) play a critical role in animal growth rates. We aimed to investigate the effect of GH and IGF-I genotypes on body weight (BW), dominance, and gene expression in slow-growing chickens at different ages. Methods: A total of 613 Korat chickens (KRs) were bred and divided into three groups by genotype - A1A1, A1A3, and A3A3 for GH and AA, AC, and CC for IGF-I. Chickens were weighed every two weeks, and liver and breast muscle tissues were collected at 10 weeks of age. Genetic parameters of KRs were estimated using ASReml software. The GH and IGF-I mRNA levels were measured by quantitative polymerase chain reaction. Significant differences between traits were analyzed using the generalized linear model. Results: A significant effect of GH genotypes on BW was found at most ages, and the A1A1 genotype had the highest value of BW. Compared with the A3A3 genotype, the A1A1 and A1A3 genotypes showed a higher dominance effect at 0 and 2 weeks, and genotype A1A1 had the highest value of dominance at 8 weeks of age. A difference in GH mRNA levels between genotypes was detected in breast muscle at 6 weeks and in the liver tissue at 2 weeks. In the case of IGF-I gene, the AA genotype had the highest BW at the beginning of life. Significant differences in BW dominance were found at 2 weeks. However, IGF-I mRNA levels were not different among genotypes in both breast muscles and liver tissues. Conclusion: Our results revealed that GH and IGF-I influence growth, but may not be involved in heterosis. GH can be used as a marker gene in selection programs for growth because the homozygous genotype (A1A1) had the highest BW at all ages. The IGF-I is not a useful marker gene for selection programs.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1349-1354
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• 2019

Objective: The objective of this study was to determine the best approach for handling missing records of first to successful insemination (FS) in Japanese Black heifers. Methods: Of a total of 2,367 records of heifers born between 2003 and 2015 used, 206 (8.7%) of open heifers were missing. Four penalty methods based on the number of inseminations were set as follows: C1, FS average according to the number of inseminations; C2, constant number of days, 359; C3, maximum number of FS days to each insemination; and C4, average of FS at the last insemination and FS of C2. C5 was generated by adding a constant number (21 d) to the highest number of FS days in each contemporary group. The bootstrap method was used to compare among the 5 methods in terms of bias, mean squared error (MSE) and coefficient of correlation between estimated breeding value (EBV) of non-censored data and censored data. Three percentages (5%, 10%, and 15%) were investigated using the random censoring scheme. The univariate animal model was used to conduct genetic analysis. Results: Heritability of FS in non-censored data was $0.012{\pm}0.016$, slightly lower than the average estimate from the five penalty methods. C1, C2, and C3 showed lower standard errors of estimated heritability but demonstrated inconsistent results for different percentages of missing records. C4 showed moderate standard errors but more stable ones for all percentages of the missing records, whereas C5 showed the highest standard errors compared with noncensored data. The MSE in C4 heritability was $0.633{\times}10^{-4}$, $0.879{\times}10^{-4}$, $0.876{\times}10^{-4}$ and $0.866{\times}10^{-4}$ for 5%, 8.7%, 10%, and 15%, respectively, of the missing records. Thus, C4 showed the lowest and the most stable MSE of heritability; the coefficient of correlation for EBV was 0.88; 0.93 and 0.90 for heifer, sire and dam, respectively. Conclusion: C4 demonstrated the highest positive correlation with the non-censored data set and was consistent within different percentages of the missing records. We concluded that C4 was the best penalty method for missing records due to the stable value of estimated parameters and the highest coefficient of correlation.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.585-591
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• 2019

Objective: This study investigated carcass characteristics and meat quality of purebred Pakchong 5, crossbred pigs sired by Pakchong 5, and crossbred pigs sired by Duroc. Methods: Forty-eight pigs (average body weight of 22.25 kg) were composed of three groups as purebred Pakchong 5 (PP), Large $White{\times}Landrace$ pigs sired by Pakchong 5 (LWLRP), and Large $White{\times}Landrace$ pigs sired by Duroc (LWLRD). Each group consisted of eight gilts and eight barrows. At 109-day-raising period, pigs were slaughtered, and carcass characteristics were evaluated. Longissimus thoracis (LT) muscles from left side of carcasses were evaluated for meat quality and chemical composition. Data were analyzed using general linear model procedure, where group, sex, and their interaction were included in the model. Results: The PP had greater carcass, total lean, and ham percentages than crossbred pigs (p<0.05). LWLRP had thicker backfat and more carcass fat percentage than LWLRD (p<0.05). There were no differences (p>0.05) on cutting percentages from tender loin, loin, boston butt, and picnic shoulder among groups. The PP and LWLRP had larger loin eye area (LEA) than LWLRD (p<0.05). Gilts had more loin percentage and lower $L^*$ value than barrows (p<0.05). No meat color parameters ($L^*$, $a^*$, and $b^*$) were affected by groups (p>0.05). PP and LWLRP had larger muscle fiber diameters than LWLRD (p<0.05). However, water holding capacity, Warner-Bratzler shear force values, and chemical composition of LT were not affected by group or sex (p>0.05). Conclusion: Pakchong 5 purebred has good carcass and lean percentages. Compared to Duroc crossbred pigs, Pakchong 5 crossbreds have similar carcass and lean percentages, larger LEA, and slightly more carcass fat, with comparable meat quality and chemical composition. Pakchong 5 boars are more affordable for very small- to medium-scale pig producers.