• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.378-384
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• 2003

Mesophilically-grown granular sludge seeded in thermophilic UASB reactor was monitored to better understand the start-up process of the reactor. The reactor was fed with a synthetic wastewater containing glucose. As COD loading rate increased stepwise, methane production rate increased. Maximum values of COD removal efficiency (95%) and methane production rate (5.3 l/day) were achieved by approximately day-80 and remained constant afterward. However, physicochemical and microbial properties of granules kept changing even after day-80. Specific methanogenic activity (SMA) was initially negligible, and increased continuously until day-153 and remained constant afterward, showing the maximum value of $1.51{\pm}0.13\;g\;CH_4-COD/g$ VSS/day. Deteriorated settling ability of granules recovered the initial value by day-98 and was maintained afterward, as determined by sludge volume index. Initially reduced granule size increased until day-126, reaching a plateau of 1.1 mm. Combined use of fluorescence in situ hybridization and confocal laser scanning microscopy (CLSM) allowed to localize families of Methanosaetaceae and Merhanosarcinaceae in granules with time Quantitative analyses of CLSM images of granule sections showed abundance patterns of the methanogens and numerical dominance of Methanosaeta spp. throughout the start-up period. The trend of SMA agreed well with abundance patterns of the methanogens.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.343-349
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• 2009

This study was designed to simplify a cryopreservation program for embryonic stem cells (ESCs) by selection of cooling method and cryoprotectant. Commercially available mouse E14 embryonic stem cells (ESCs) were cryopreserved with various protocols, and morphology and viability of the frozen-thawed ESCs and their reactive oxygen species (ROS) production were subsequently monitored. Post-thaw colony-formation of ESCs was detected only after a slow freezing using dimethyl sulfoxide (DMSO) by stepwise placement of a freezing container into a $-80^{\circ}C$ deep freezer and subsequently into -$196^{\circ}C$ liquid nitrogen, while no proliferation was detected after vitrification. When the simplified protocol was employed, the replacement of DMSO with a mixture of DMSO and ethylene glycol (EG) further improved the post-thaw survival. ROS generation in ESCs frozen-thawed with the optimized protocol was not increased compared with non-frozen ESCs. The use of fresh mouse embryonic fibroblasts as feeder cells for post-thaw subculture did not further increase post-thaw cell viability. In conclusion, a simplified slow-freezing program without employing programmable freezer but using DMSO and EG was developed which maintains cell viability and colony-forming activity of ESCs during post-thaw subculture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.238-247
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• 2006

The purpose of this study was to evaluate school dieticians' performance of nutritional quality control, and further to establish effective and objective standards of nutritional quality control. Data for this study came from 200 school dieticians' responses in the Chungbuk area. The total quality management (TQM)-based questionnaire was structured. The questionnaire consisted of the following four fields (1) performance of nutritional quality control, (2) performance of stepwise food production to maximize nutrient preservation rate, (3) management of documents and records related to nutritional quality control, and (4) other relating matters. The items of the questionnaire were measured on a five-point Likert scale which ranged from 'strongly agree' to 'strongly disagree'. First, the analysis indicated that school dieticians performed 'least' on human resource management', 'mediocre' on nutritional quality control, and best on 'leadership'. Second, the analysis on performance of stepwise food production to maximize nutrient preservation rate showed that dieticians considerably endeavored to maximize nutrients of cooked food, but it was found out that the most of nutrient destruction can be caused by heating during cooking. Third, the result showed that the systematic use of documents and records for nutritional quality control was not sufficiently accomplished, especially in the production phase of food. In addition, the measure by the Pearson correlation coefficient indicated that there was a significant relationship between performance of nutritional quality control and performance of stepwise food production to maximize nutrient preservation rate, and between performance of nutritional quality control and management of documents and records related to nutritional quality control. Finally, the findings of this study suggest that more effort should be exerted to carefully establish TQM-based standards for the improvement of nutritionary quality.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.939-950
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• 2023

This study was conducted to assess the impact of growing condition variables on alfalfa (Medicago sativa L.) productivity. A total of 197 alfalfa yield results were acquired from the alfalfa field trials conducted by the South Korean National Agricultural Cooperative Federation or Rural Development Administration between 1983 and 2008. The corresponding climate and soil data were collected from the database of the Korean Meteorological Administration. Twenty-three growing condition variables were developed as explaining variables for alfalfa forage biomass production. Among them, twelve variables were chosen based on the significance of the partial-correlation coefficients or potential agricultural values. The selected partial correlation coefficients between the variables and alfalfa forage biomass ranged from -0.021 to 0.696. The influence of the selected twelve variables on yearly alfalfa production was summarized into three dominant factors through factor analysis. Along with the accumulated temperature variables, the loading scores of the daily mean temperature higher than 25℃ were over 0.88 in factor 1. The sunshine duration at temperature between 0℃-25℃ was 0.939 in factor 2. Precipitation days were 0.82, which was the greatest in factor 3. Stepwise regression applied with the three dominant factors resulted in the coefficients of factors 1, 2, and 3 for 0.633, 0.485, and 0.115, respectively, and the R-square of the model was 0.602. The environmental conditions limiting alfalfa growth, such as daily temperature higher than 25℃ or daily mean temperature affected annual alfalfa production most substantially among the growing condition variables. Therefore, future cultivar selection should consider the capability of alfalfa to be tolerant to extreme summer weather along with biomass production potential.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.412-418
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• 1985

Two fertilizer levels were treated to the nine barley varieties developed at different years to investigate the morphological and physiological traits related to grain yields. Recently developed varieties were higher in amounts of chlorophyll and nitrogen content of leaf, root activity, root weight and specipic leaf weight as compared with older varieties. Dry matter production was closely related to NAR rather than LAI in new varieties, but indicating the reverse results in older varieties. They showed higher NAR and light transmission rate in new varieties but higher LAI in older varieties. Leaves in new varieties were distributed uniformly according to its position on clum. However, leaves in older varieties arranged irregularly showing more distribution at the upper and middle positions on culm. The factors which showed high correlations with grain yield were chlorophyll content, root activity, NAR, and nitrogen content of leaf of which stepwise multiple regression with grain yield indicated that 90% of total variance was occupied by chlorophyll content, root activity and dry matter.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.441-448
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• 1994

Postweaning performance data were obtained on 187 group fed purebred Angus calves from 12 selected sires (six high and six low feed conversion sires) in 1985 and 1986. The objective of this portion of the study was to develop prediction equations for feed conversion from a stepwise regression analysis. Variables measured were on-test weight (ONTSTWT), on-test age (ONTSTAG), five weights by 28-d periods, seven linear body measurements: heart girth (HG), hip height (HH), head width (HDW), head length (HDL), muzzle circumference (MC), length between hooks and pins (HOPIN) and length between shoulder and hooks (SHHO), and backfat thickness (BF). Stepwise regressions for maintenance adjusted feed conversion (ADJFC) and unadjusted feed conversion (UNADFC) over the first 140 d of the test, and total feed conversion (FC) until progeny reached 8.89 mm of back fat were obtained separately by conversion groups and sexes and for combined feed conversion groups and sexes. In general, weights were more important than linear body measurements in prediction of feed utilization. To some extent this was expected as weight is related directly to gain which is a component of feed conversion. Weight at 112 d was the most important variable in prediction of feed conversion when data from both feed conversion groups and sexes were combined. Weights at 84 and 140 d were important variables in prediction of UNADFC and FC, respectively, of bulls. ONTSTWT and weight at 140 d had the highest standardized partial regression coefficients for UNADFC and ADJFC, respectively, of heifers. Results indicated that linear measurements, such as MC, HDL and HOPIN, are useful in prediction of feed conversion when feed in takes are unavailable.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.155-159
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• 2007

Ethanolysis of squid viscera oil with immobilized lipase was investigated for reducing the free fatty acid contents and enhancing the function of the oil by stepwise addition method of Shinmada[1]. Tendency of oil variation during Ethanolysis showed increased content of diglyceride, monoglyceride and fatty acid ethyl ester with reduced free fatty acid contents. The oil composition was analyzed using GC-FID and compared before and after ethanolysis. Structural analysis of the lipid was performed by HPLC-UV spectrophotometer during ethanolysis. The transformed oil was thought to has suitable properties for functional oil production.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.580-585
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• 1998

The study was conducted to determine if variation in protein yield can be explained by expressions of early lactation somatic cell score (SCS) and if prediction can be improved by including SCS among the predictors. A data set was prepared (n = 663,438) from Wisconsin Dairy Improvement Association (USA) records for protein yield with sample days near 20. Stepwise regression was used requiring F statistic (p < .01) for any variable to stay in the model. Separate analyses were run for 12 combinations of four seasons and first three parities. Selection of SCS variables was not consistent across seasons or lactations. Coefficients of detennination ($R^2$) ranged from 51 to 61% with higher values for earlier lactations. Including any expression of SCS in the prediction equations improved $R^2$ by < 1 %. SCS was associated with milk yield on the sample day, but the association was not strong enough to improve the prediction of future yield when other expressions of milk yield were in the model.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.735-738
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• 2001

Metabolically engineered Escherichia coli strains harboring a plasmid containing a novel artificial polyhydroxyalkanoate (PHA) operon consisting of the Aeromonas PHA biosynthesis related genes and Ralstonia eutropha reductase gene were developed for the production of poly(3-hydroxybutyrate-co-hydroxyhexanoate) [P(3HB-co-3HHx)] from dodecanoic acid. By applying stepwise reduction of dissolved oxygen concentration (DOC) during the fermentation, the final dry cell weight, PHA concentration, and PHA content of 79 g/L, 21.5 g/L, and 27.2 wt%, respectively, were obtained in 40.8 h, which resulted in the PHA productivity of 0.53 g/L/h. The 3HHx fraction slowly increased during the fed-batch culture to reach a final value of 10.8 mol%. The 3HHx fraction in the copolymer could be increased by three fold when the Aeromonas hydrophila orfl gene was co-expressed with the PHA biosynthesis genes.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.83-89
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• 1996

Multivariate statistical procedures were used to analyse data on the chemical composition and in vitro digestibility of four varienties of rice straw after treatment with 4% NaOH solution, 4% urea solution or distilled water (control) for 48 hours. For each treatment, stepwise discriminant analysis identified the variables which maximized differences between varieties and the eigenvectors from principal component analysis quantified the contribution of these criterion variables to varietal differences. The overall response of varieties to chemical treatment was demonstrated qualitatively, by cluster analysis, and quantitatively, from the magnitude of the principal component scores. The analysis revealed that the urea and control treatments elicited the same response whereas NaOH had the greatest effect on the poorest straw variety. Similar analyses conducted on the botanical fractions of the varieties showed that the relative response of the inflorescence, stem, leaf blade and leaf sheath fractions was not altered by chemical treatment.