• Journal of Microbiology and Biotechnology
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• 제13권3호
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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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• 제22권3호
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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.

• 한국식품영양과학회지
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• 제35권2호
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• pp.238-247
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• 2006

학교급식의 영양적 품질관리 기준을 설정하기 위한 자료를 얻고자 총체적 품질 경영(TQM)을 기초로 영양적 품질관리 수행도를 평가하였다. 충북지역 초${\cdot}$중 ${\cdot}$고등학교 급식 영양사 200명을 대상으로 질문지법을 이용하여 영양적 품질관리 수행도와 음식 생산단계별 수행도 및 영양적 품질관리 관련문서 및 서식 사용현황을 조사하였다. 총체적 품질경영을 기초로한 영양적 품질관리 영역에서 평균 3.12/5점의 수행도를 보였으며, 그 중 '리더십' 영역에서 높은 수행도(3.66)를 보였고, '인적자원 중시' 영역에서 가장 낮은 수행도(2.66)를 보였다. 학교유형과 급식 실시시기에 따라 전략계획, 고객 및 시장중시, 사업성과 영역에서 유의적인 차이를 보였다. (p<0.05). 영양사의 인구통계적 변인에 따라서는 연령, 근무경력, 고용상태에 의한 차이를 보였는데(p<0.05), $30\~40$대가 20대보다 리더쉽이 높고, 급식의 전략계획을 더 잘 수행하고 있었다. 리더쉽과 전략계획, 인적자원 중시 영역에서 10년 이상의 경력자가 이하보다 수행도가 더 높았다(p<0.05). 음식 생산단계별 수행도는 평균 3.72/5점의 수행도를 나타내었고, 학교 특성별로는 초등학교 영양사가 중${\cdot}$고등학교에 비해 건열조리법과 분산조리법 및 가열시 온도조절의 효과적 사용을 통해 가열처리 시간을 최소화하여 영양소보존을 더 잘 수행하고 있었다(p<0.05). 영양사의 경우 연령에 따라 차이를 나타내었는데, 30, 40대가 20대보다 구매 영역에서 더 높은 수행도를 보였다(p<0.05). 영양적 품질관리를 위한 관련문서 및 서식 사용현황 평가에서 평균 $60.6\%$의 보유율 을 보였으며, 급식섭취량 조사일지$(42.0\%)$와 직무기술서$(41.0\%)$는 $50.0\%$ 미만의 보유율 나타냈다. 학교 특성별로는 학교유형별로(p<0.05), 영양사의 경우에는 연령에 따라 유의적 차이를 나타내었다(p<0.05). 영양적 품질관리 수행도와 음식 생산단계별 수행도 및 관련문서${\cdot}$서식 사용현황 간에는 각각 0.55, 0.45의 상관관계를 나타내었다. 학교급식의 영 양적 품질관리(TQM) 수행도 평가 결과, 인적자원 중시에 대한 수행도가 낮으므로, 조리종사원의 영양적 품질관리 향상을 위한 교육 및 지도를 위한 교육프로그램 개발이 필요하다. 음식 생산단계별 영양 손실을 최소화하기 위해 가열조리 단계를 중요관리 점으로 설정하고 이를 관리 할 수 있는 관리기준의 개발이 시급하다. 결론적으로 TQM을 기반으로 한 영양적 품질향상을 위한 기준이 설정되어 실제적으로 적용되어야 한다.

• Journal of Animal Science and Technology
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• 제65권5호
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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.

• 한국작물학회지
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• 제30권4호
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• pp.412-418
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• 1985

육성연대가 다른 보리품종의 생리, 형태적 특성변화와 수량성과의 관계를 구명하여 육종 및 재배법개선의 기초자료로 삼고져 보리 9품종을 2시비수준에서 재배하여 조사, 분석한 결과는 다음과 같다. 1. 근년에 육성된 품종들은 과거에 육성된 품종들에 비하여 엽록소함량, 엽신질소함량, 근활력, 근중, 비엽중(SLW) 및 순동화율이 높은 반면 엽면적지수는 낮았다. 2. 근년에 육성된 품종의 건물생산은 NAR보다 LAI와 밀접한 관계가 있었으나 과거에 육성된 품종은 반대의 경향이었다. 3. 엽층의 분포가 신품종들은 상하부에 고르게 분포되어 있으나 과거에 육성된 품종은 중상부에 집중되어 있었다. 4. 수량과 상관이 높았던 요인들은 엽록소함량, 근활력, 순동화율, 엽신질소함량 등이었으며, Stepwise multiple regression분석에서 엽록소함량, 근활력, 지상부건물중이 회귀식에 들어갔을 때 분산의 90% 정도가 되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권3호
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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.

• 한국해양바이오학회지
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• 제2권3호
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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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• 제11권5호
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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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• 한국생물공학회 2001년도 추계학술발표대회
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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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• 제9권1호
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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.