• Food Science of Animal Resources
• /
• v.38 no.3
• /
• pp.580-592
• /
• 2018

The formulation of an oil/water (o/w) emulsion made up of a mixture of perilla oil and canola oil (30/70 w/w) was optimized using a response surface methodology to find a replacement for animal fat in an emulsion-type meat product. A 12 run Plackett-Burman design (PBD) was applied to screen the effect of potential ingredients in the (o/w) emulsion, including polyglycerol polyricinoleate (PGPR), fish gelatin, soy protein isolate (SPI), sodium caseinate, carrageenan (CR), inulin (IN) and sodium tripolyphosphate. The PBD showed that SPI, CR and IN showed promise but required further optimization, and other ingredients did not affect the technological properties of the (o/w) emulsion. The PBD also showed that PGPR played a critical role in inhibiting an emulsion break. The level of PGPR was then fixed at 3.2% (w/w total emulsion) for an optimization study. A central composite design (CCD) was applied to optimize the addition levels of SPI, CR or IN in an (o/w) emulsion and to observe their effects on emulsion stability, cooking loss and the textural properties of a cooked meat emulsion. Significant interactions between SPI and CR increased the cooking loss in the meat emulsion. In contrast, IN showed interactions with SPI leading to a reduction in cooking loss. Thus, CR was also removed from the formulation. After optimization, the level of SPI (4.48% w/w) and IN (14% w/w) was validated, leading to a perilla-canola oil (o/w) emulsion with the ability to replace animal fat in an emulsion-type meat products.

• Journal of Aquaculture
• /
• v.19 no.1
• /
• pp.57-63
• /
• 2006

This study was conducted to investigate the effects of dietary supplementation of spirulina (SPI) and asthaxanthin (AST) on growth performance and antioxidant activity in juvenile olive flounder (Paralichthys olivaceus) in low temperature season. Total 180 fish ($27.8{\pm}0.3g$, average weight ${\pm}S.D.$) were randomly divided into 12 groups, and 3 groups were fed one of four isonitrogenous (52% CP) and isocaloric $(18.3\;MJ\;kg^{-1})$ diets containing no SPI and AST, 0.5% SPI, 0.5% AST, and 0.5% each SPI and AST (designated by diets Control, SPI, AST and SPI+AST, respectively). After 6 weeks of feeding trial, the growth performance, feed utilization, whole body composition and survival of fish were not significantly affected by the experimental diets. There were no significant differences in hematocrit, hemoglobin, alanine aminotransferase and aspartate aminotransferase of fish fed all the experimental diets. The DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay indicated numerically increased antioxidant activity in liver of fish fed the SPI diet compared to that of fish fed the control diet, even though it was not significant. The present study shows that a low level (0.5%) of dietary supplementation of SPI and/or AST does not affect growth and feed utilization and intake of juvenile olive flounder in low temperature season.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.11
• /
• pp.314-321
• /
• 2016

Adapting the maintenance criteria of Seoul City pavement is not applicable for borough pavement due to differences between the pavement of Seoul city and the borough, such as priority of maintenance, traffic volume, thickness of pavement, and pavement deterioration rate by distresses. To develop an efficient and reasonable evaluation method of the Seocho borough pavement condition within a limited budget, this study suggested the borough pavement condition evaluation model based on the PMS (Pavement Management System) of Seoul Metropolitan SPI (Seoul Pavement Index). The SPI was modified to predict the remaining life and determine the proper maintenance method for the pavement in Seocho borough. This was suggested to reflect the rate of the designed performance life and field performance life of pavement as well as the pavement condition at the stage of the completion of construction. Primary variables, such as crack, rutting and IRI in the final model affect the overall performance life due to their even composition. Therefore, the suggested model considering the lowered criteria, design performance factor, and construction factor can be used for the more efficient maintenance of Seocho borough pavement.

• Journal of Korea Water Resources Association
• /
• v.56 no.8
• /
• pp.509-520
• /
• 2023

Various drought indices are widely used for assessing drought conditions which are affected by many factors such as precipitation, soil moisture, and runoff. The values of drought indices varies depending on hydro-meteorological data and calculation formulas, and the judgment of the drought condition may also vary. This study selected four calculation components such as precipitation data length, accumulation period, probability distribution function, and parameter estimation method as the sources of uncertainty in the calculation of standardized precipitation index (SPI), and evaluated their contributions to the uncertainty using root mean square error (RMSE) and linear mixed model (LMM). The RMSE estimated the overall errors in the SPI calculation, and the LMM was used to quantify the uncertainty contribution of each factor. The results showed that as the accumulation period increased and the data period extended, the RMSEs decreased. The comparison of relative uncertainty using LMM indicated that the sample size had the greatest impact on the SPI calculation. In addition, as sample size increased, the relative uncertainty related to the sample size used for SPI calculation decreased and the relative uncertainty associated with accumulation period and parameter estimation increased. In conclusion, to reduce the uncertainty in the SPI calculation, it is essential to collect long-term data first, followed by the appropriate selection of probability distribution models and parameter estimation methods that represent well the data characteristics.

• Clinical and Experimental Reproductive Medicine
• /
• v.20 no.1
• /
• pp.19-29
• /
• 1993

Plasminogen activator (PA)-plasmin system in follicular fluid is involved in the process leading to follicular rupture at ovulation. It is well known that PA is closely associated with cellular differentiation and tissue remodeling on evidences from the study of normal and malignant tissues. This study was designed to ascertain a potential role of PA in the ovarian folliculogenesis. Immature Sprague-Dawley rats were injected with pregnant mare serum gonadotropin, followed by injection of serine protease inhibitor (SPI; mixture of 1 mol/L benzamidine and 1 mol/L amino-caproic acid) into the unilateral ovarian bursa. In the control study, mechanical effect of bursal injection and contralateral ovarian effect SPI were ruled out. Total antral follicular areas relative to total ovarian cross-sectional areas was siginificantly lower in SPI-injected ovary than in saline-injected ovary. SPI injection decreased the relative antral follicular area by 33 % respectively. Electron microscopic finding of granulosa cell in the atretic follicle showed the presence of pyknotic nucleus, blurring of neucleolemma, degeneration of mitochondria and dilation of endoplasmic reticulum. After induction of ovulation with hCG, the number of oocytes released was significantly decreased in SPI-injected oviduct than in saline-injected oviduct. From above results, author discussed that PA may play a role not only in ovulation but also in some processes of folliculogenesis.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.6
• /
• pp.617-626
• /
• 2011

Transglutaminase from Streptomyces mobaraensis is an enzyme of unknown function that cross-links proteins to high molecular weight aggregates. Previously, we characterized two intrinsic transglutaminase substrates with inactivating activities against subtilisin and dispase. This report now describes a novel substrate that inhibits papain, bromelain, and trypsin. Papain was the most sensitive protease; thus, the protein was designated Streptomyces papain inhibitor (SPI). To avoid transglutaminase-mediated glutamine deamidation during culture, SPI was produced by Streptomyces mobaraensis at various growth temperatures. The best results were achieved by culturing for 30-50 h at $42^{\circ}C$, which yielded high SPI concentrations and negligibly small amounts of mature transglutaminase. Transglutaminasespecific biotinylation displayed largely unmodified glutamine and lysine residues. In contrast, purified SPI from the $28^{\circ}C$ culture lost the potential to be cross-linked, but exhibited higher inhibitory activity as indicated by a significantly lower $K_i$ (60 nM vs. 140 nM). Despite similarities in molecular mass (12 kDa) and high thermostability, SPI exhibits clear differences in comparison with all members of the wellknown family of Streptomyces subtilisin inhibitors. The neutral protein (pI of 7.3) shares sequence homology with a putative protein from Streptomyces lavendulae, whose conformation is most likely stabilized by two disulfide bridges. However, cysteine residues are not localized in the typical regions of subtilisin inhibitors. SPI and the formerly characterized dispase-inactivating substrate are unique proteins of distinct Streptomycetes such as Streptomyces mobaraensis. Along with the subtilisin inhibitory protein, they could play a crucial role in the defense of vulnerable protein layers that are solidified by transglutaminase.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
• /
• 2001.12a
• /
• pp.61-68
• /
• 2001

Soybean, rice and nuts are the staple foods in South East Asia. In order to clarify the function of these foods in relation to coronary heart diseases, we have done a series of experiments using animals and humans. Soybean protein preparations (SPI) in comparison with an animal protein, casein (CAS), resulted in reducing atherosclerotic lesion development in apolipoprotein (apo) E deficient mice that develop an advanced lesion similar to that in humans. This action was attributed to the protein, since the ethanol-extracted SPI (EE-SPI), from which isoflavones and saponins removed, lowered the lesion development in apo E-deficient mice. However, The EE-SPI, compared to the SPI, resulted in a decrease of mRNA for key proteins of cholesterol metabolism (low density lipoprotein receptor and cholesterol 7$\alpha$-hydroxylase) in hypercholesterolemic rats, followed by an elevation of the serum cholesterol level, indicating a contribution of isoflavones to the serum cholesterol level. Rice protein (RPI) was also effective to lower the lesion development in apo E deficient mice. Both the SPI and RPI led to an increased level of the serum NOiN03, metabolites of NO. This effect appeared to be attributed to their high content of arginine. Besides, C57BL/6J mice fed a diet containing whole grain rice had an elevation of the serum high-density lipoprotein cholesterol. Furthermore, rice bran oil and the unsaponifiable fraction that is rich in plant sterols were effective to lower serum cholesterol levels in hypercholeserolemic rats. Finally, we tested if walnuts consumption would be hypocholesterolemic for Japanese. A diet containing walnuts effectively lowered the serum total and low density lipoprotein cholesterol in Japanese men and women. These animal and human experiments would be relevant to advocate publics to keep consuming diets including soybean, rice and nuts for their healthful life.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.225-225
• /
• 2015

Drought events usually evolve slowly in time and their impacts generally span a long period of time. This indicates that the sequence of drought is not completely random. The Hidden Markov Model (HMM) is a probabilistic model used to represent dependences between invisible hidden states which finally result in observations. Drought characteristics are dependent on the underlying generating mechanism, which can be well modelled by the HMM. This study employed a HMM with Gaussian emissions to fit the Standardized Precipitation Index (SPI) series and make multi-step prediction to check the drought characteristics in the future. To estimate the parameters of the HMM, we employed a Bayesian model computed via Markov Chain Monte Carlo (MCMC). Since the true number of hidden states is unknown, we fit the model with varying number of hidden states and used reversible jump to allow for transdimensional moves between models with different numbers of states. We applied the HMM to several stations SPI data in South Korea. The monthly SPI data from January 1973 to December 2012 was divided into two parts, the first 30-year SPI data (January 1973 to December 2002) was used for model calibration and the last 10-year SPI data (January 2003 to December 2012) for model validation. All the SPI data was preprocessed through the wavelet denoising and applied as the visible output in the HMM. Different lead time (T= 1, 3, 6, 12 months) forecasting performances were compared with conventional forecasting techniques (e.g., ANN and ARMA). Based on statistical evaluation performance, the HMM exhibited significant preferable results compared to conventional models with much larger forecasting skill score (about 0.3-0.6) and lower Root Mean Square Error (RMSE) values (about 0.5-0.9).

• Applied Chemistry for Engineering
• /
• v.2 no.4
• /
• pp.340-347
• /
• 1991

Siloxane containing copolyimide (SPI) was synthesized from 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride(BTDA), 4, 4'-methylene dianiline(MDA), 4, 4'-oxydianiline(ODA) and amine-terminated polydimethyl-siloxane(PDMS). Homopolyamic acid(HPAA) in tetrahydrofuran(THF) was reacted with PDMS to obtain siloxane containing polyamic acid(SPAA) followed by the thermal curing to manufacture SPI. SPAA and HPAA exhibited inherent viscosity value of 0.35~0.48dl/g. Glass transition temperature of SPI ranged in $258^{\circ}C{\sim}264^{\circ}C$. SPI had a lower $T_g$ than that of HPI. ODA based HPI and SPI showed slightly higher $T_g$ values, thermal stability, and water content.

• Journal of Korea Water Resources Association
• /
• v.46 no.8
• /
• pp.795-805
• /
• 2013

Drought is one of the severe natural disasters and it can profoundly affect our society and ecosystem. Also, it is a very important variable for water resources planning and management. Therefore, the drought is analyzed in this study to understand the drought distribution and trend. The Standard Precipitation Index (SPI) is estimated using precipitation data obtained from 55 rain gauge stations in South Korea and the SPI based drought variables such as drought duration and drought severity were defined. Drought occurrence and joint probabilistic analysis for SPI based drought variables were performed with run theory and copula functions. And then the return period and spatial distribution of droughts on the South Korea was estimated. As the results, we have shown that Gongju and Chungju in Chungcheong-do and Wonju, Inje, Jeongseon, Taebeak in Gangwon-do have vulnerability to droughts.