• 한국토양비료학회지
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• 제43권2호
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• pp.174-179
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• 2010

본 연구에서는 사탕무의 시비반응을 합리적으로 해석하고 경제성 있는 최적 시비량 및 최대 수확량의 도출을 위한 방법을 검토하기 위하여 간척지 토양에서 수준별 질소비료와 돈분퇴비의 시용에 따른 사탕무의 시비반응을 조사하였다. 시비반응은 Quadratic model, Exponential model, Square root model 및 Linear response & plateau model을 이용하여 통계적으로 분석하였다. 토양 EC가 증가함에 따라 사탕무 지하부 생체중이 지수함수적으로 감소하였다. 질소비료 시비수준별 사탕무 지하부 생체량의 시비반응은 Linear response에서 결정계수 & plateau model ($R^2$)가 $0.92^{**}$로 고도의 통계적 유의성을 보였으며, Linear response & plateau model에서 최적 질소시비량 ($N_{opt}$)은 138 kg $ha^{-1}$으로 나타났다. 돈분퇴비의 시비반응은 Quadratic model에서 $0.99^{**}$의 유의성 있는 결정계수 ($R^2$)를 보였으며, 최적 퇴비시비량은 각각 9.17 tons $ha^{-1}$으로 나타났다. 상기 결과로 볼 때 사탕무에서 질소와 돈분퇴비의 시비반응을 적절히 평가하기 위해서는 각각 Linear response & plateau model과 Quadratic model을 이용하는 것이 합리적인 것으로 판단되었다.

• Journal of Animal Science and Technology
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• 제62권5호
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• pp.628-637
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• 2020

In poultry diets, a requirement of crude protein is one of the most important factors in poultry productivity. Besides, the Pekin duck requirement of crude protein is still not clear. This experiment was conducted to determine the crude protein requirement of Pekin duck on diet formulation by investigation of growth performance, carcass trait, and analysis of blood parameter for a hatch to 21-day (d) of age. A total of 432 male White Pekin ducks were randomly allocated to six levels of crude protein (i.e., 15%, 17%, 19%, 21%, 23%, and 25%) to give six replicate pens per treatment with 12 ducklings per each pen. Body weight and feed intake were measured weekly by calculating feed conversion ratio and protein intake. Two ducklings each pen was euthanized via cervical dislocation for analysis of carcass trait and plasma blood on 21-d of age. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. The level of crude protein requirements of Pekin ducks for 21 days after the hatch was estimated to be 20.63% and 23.25% diet for maximum daily gain, and minimum feed conversion ratio, respectively.

• 한국가금학회지
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• 제44권4호
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• pp.245-251
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• 2017

A dose-response experiment was conducted to determine the lysine requirement for broiler breeder hens during pre-peak production. Totally, one hundred and twenty-six flock 23-week-old Ross 308 broiler breeder hens with similar body weight were selected ($2,188{\pm}32g$) for a 6-week experiment. Hens were fed with a basal diet of corn-wheat-soybean meal formulated to achieve the Ross 308 breeder nutrient specifications (2016), except for lysine. The 7 graded, daily lysine intake levels used in this experiment were 732, 785, 838, 891, 944, 997, and 1,050 mg, and hens were restricted to 133 g of feed throughout this experiment. Pen based egg production were recorded once a day and all eggs were weighed daily. Age at sexual maturity was determined when the hens attained age at 25% production. Body weight at 23~29 weeks of age was not affected (P>0.05) by lysine levels. By fitting a linear-plateau model, the daily lysine requirements for feed conversion ratio, total produced egg weight, and age at sexual maturity at 23~29 weeks of age were estimated as 865, 907, and 891 mg, respectively. Using a quadratic-plateau model, the daily lysine requirement at 23~29 weeks of age were estimated as 974, 964, and 950 mg for feed conversion ratio, total produced egg weight, and age at sexual maturity, respectively. These results suggested that the daily lysine requirement for modern broiler breeder hens according to the National Research Council (1994) are insufficient for higher total produced egg weight, sexual maturity, and feed efficiency, and 120% of the NRC recommendation level would improve hen productivity when data are fitted under linear- and quadratic-plateau models.

• Radiation Oncology Journal
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• 제6권1호
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• pp.1-11
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• 1988

방사선 조사 후 발생한 잠재치사손상의 회복(PLDR)에 있어 조사선량 및 시간에 따른 환경변화가 회복의 동적양상에 미치는 영향을 Vero 세포계를 이용하여 실험하였다. 배양액을 교환시키지 않고 배양하여 평형기에 도달한 세포에 동물실험용 세시움 조사기로 $1Gy\~9Gy$의 감마선을 조사하고 각 조사조건에서 $O\~6$ 및 24시간동안 정치시킨 후 Agarose가 포함된 새로운 배양액에서 배양하였다. 16Gy를 조사한 동종의 세포를 feeder세포로 첨가하여 배양액내의 전 체세포수를 일정하게 한 조건에서 형성된 세포집락수에 따라 세포의 생존을 정하였다. 잠재치사손상의 회복은 $2\~4$시간 정치후에 포화수준에 도달한 빠른 회복이었다. 방사선량이 증가함에 따라 회복속도는 증가하였고, 포화수준의 회복량도 증가하였다. Linear-quadratic mode에 의한 "방사선량-생존분획" 분석 결과 잠채치사손상이 회복됨에 따라 일차 비활성계수 $\alpha$는 급속히 감소하여 $\beta$에 접근하였고 이차 비활성계수 $\beta$는 미미하게 증가하여 PLDR은 $\alpha$로 표시되는 손상에 주로 영향을 주었다. Multitarget model에 따라 분석한 결과 Do는 변화가 없고 Dq가 증가하였다. 세포 생존분획 이 높은 3Gy 이하의 저선량 영역에서 dose modifying factor가 높아 잠재 치사손상의 회복에 의한 영향이 저선량 영역에서 상대적으로 크게 나타났다.

• Radiation Oncology Journal
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• 제11권1호
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• pp.17-27
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• 1993

To investigate the relationship between radiosensitivity and postirradiation recovery in human cancer cells, a study was performed using human cancer cell lines-A549, CaSki, SNU-C5 and PCI-13. For the study of radiosensitivity, single doses of 2, 4, 6, 8, 10, 12, and 14 Gy were given and for postirradiation recovery, two fractions of 4 Gy were separated with a time interval of 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, or 6 hours. Surviving fraction was estimated using colony forming ability. Surviving fractions at 2 Gy (SF2) were 0.496 (0.570-0.412) for A549, 0.496 (0.660-0.332) for CaSki, 0.386 (0.576-0.216) for SNU-C5, and 0.185 (0.247-0.123) for PCI-13. By statistical analysis the SF2 of PCI-13 was lower significantly than those of others (p<0.05). This difference was also observed at 4, 6 and 8 Gy dose levels. At 6 and 8 Gy the surviving fractions of SNU-C5 were also lower significantly than A549 and CaSki (p<0.05). By the analysis with linear quadratic model, the values of ${\alpha}$ for A549, CaSki, SNU-C5 and PCI-13 were 0.3016, 0.3212, 0.4327 and 0.8423, respectively, and those of ${\beta}$ were 0.02429, 0.02009, 0.03349 and 0.00059, respectively. So, the value of ${\alpha}$ showed increasing tendency with decreasing SF2. By the multitarget single hit model the values of Do for A549, CaSki, SUN-C5 and PCI-13 were 1.97, 1.97, 1.46 and 0.81, respectively, and those of n were 1.53, 1.50, 1.56 and 2.28, respectively. So, the value of Do decreased with decreasing SF2. Post-irradiation recovery reached plateau at around 2 hours. Recovery ratio at plateau phase ranged from 1.2 to 4.2; the value were 1.2 for PCI-13, 3.2 for CaSki, 3.3 for SNU-C5, and 4.2 for A549. Recovery rate well correlated with SF2, and increased with increasing Do and decreasing ${\alpha}$. According to above results, the intrinsic radiosensitivity was quite different among the tested cell lines; PCI-13 was the most sensitive and A549 and CaSki was similar. This difference of radiosensitivity is thought to be partly due to the difference in amount of postirradiation recovery. By linear quadratic model the difference of ${\alpha}$ values was very high, and by multitarget single hit model the difference of Do value was significantly high among four cell lines.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.471-480
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• 2022

This experiment was conducted to determine the maximum dietary energy levels on growth performance and carcass characteristics of White Pekin duck. the Six dietary treatments were formulated based on their apparent metabolizable energy (AME) concentrations from 2,700 to 3,200 kcal/kg with a 100 kcal/kg gap to evaluate the accurate dietary AME requirement to address current knowledge and further issues for fulfilling the genetic potential of meat-type white Pekin ducklings. A total of 432 one-day-old male White Pekin ducklings were randomly allocated into one of six dietary treatments with six replicates (12 birds per pen). The diets were formulated as corn-soybean meal-based diets to meet or exceed the Nutrient Requirement of Poultry specification for meat-type ducks. Growth performance indices (i.e. average daily gain [ADG], average daily feed intake, feed conversion ratio) were measured weekly. Medium body weight (BW) ducklings from each pen were sacrificed to analyze the carcass traits and abdominal fat content on day 21. Obtained data were analyzed to estimate significant effect using the one-way ANOVA of IBM SPSS Statistics (Version, 25). If the p-value of the results were significant, differences in means among treatments were separated by Tukey's post hoc test. Significant differences were then analyzed with a linear and quadratic broken model to estimate the accurate concentration of AME. Ducklings fed higher dietary AME diets increased (p < 0.05) BW, ADG. Ducklings fed higher AME than 2,900 kcal/kg diets increased abdominal fat accumulation and leg meat portion. The estimated requirement by linear plateau method showed from 3,000.00 kcal/kg to 3,173.03 kcal/kg whereas the requirement by quadratic plateau method indicated from 3,100.00 kcal/kg to 3,306.26 kcal/kg. Collectively, estimated dietary requirements exhibit diverse results based on the measured traits and analysis methods. All the estimated requirements in this experiment present higher than previous research, the maximum requirement for the next diet formulation should be selected by the purpose of the diet.

• Radiation Oncology Journal
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• 제16권2호
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• pp.99-106
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• 1998

목적 : 임상에서 발생빈도가 높은 위선암, 폐선암, 망막세포종, 자궁경부 편평상피암의 4가지 인 체암세포주(MKN-45, PC-14, Y-79, HeL)를 이용하여 방사선조사후 세포생존분획 및 세포생존곡선의 모양을 결정하는 지표를 구하고 방사선조사후 손상 회복정도를 측정하여 이들 여러 지표간의 상관관계 여부를 구명하기 위하여 본실험을 시행하였다. 대상 및 방법 :각 세포주의 방사선감수성을 보기 위하여 1, 2, 3, 5, 7 및 10Gy의 방사선을 1 회 조사하였고 방사선조사후 준치사손상 회복정도를 보기 위하여 5Gy씩 2회의 방사선조사를 0, 1, 2, 3, 4, 6 및 24시간 간격으로 시행하였다. 세포의 생존분획은 $Sperman-K\"{a}rbor$ 방법으로 세포집락형성능력을 측정하여 산출하였으며 생존곡선의 수학적 분석은 linear-quadratic(LQ), multitarget-single hit(MS) 모형과 mean inactivation $dose(\v{D})$를 이용하였다. 결과 : 방사선조사후의 세포생존 실험결과 2Gy에서의 세포생존분획(SF2)은 0.174에서 0.85까지 다양하게 나타났으며 Y-79는 유의하게 낮은 SF2를, PC-14는 높은 SF2를 나타내었다(p<0.05, t-test). LQ model로 분석한 방사선 세포생존곡선의 분석결과 Y-79, MKN-45, HeLa, PC-14에서 ${\alpha}$가 각각 0.603, 0.355, 0.275, 0.102이었고 ${\beta}$는 각각 0.005, 0.016, 0.025, 0.027이었다. MS model로 분석한 결과는 Y-79, MKN-45, HeLa, PC-14에서 Do가 각각 1.59, 1.84, 1.88, 2.52였고 n은 0.97, 1.46, 1.52, 1.69를 보였다. 한편 Gauss-Laguerre방법으로 계산한 $\v{D}$는 Y-79, MKN-45, HeLa, PC-14에서 각각 1.62, 2.37, 2.61, 3.95였다. SF2가 감소함에 따라 ${\alpha}$값은 증가하였고 Do, $\v{D}$값은 감소하였으며 이들간의 Pearson 상관계수는 각각 0.953, 0.993, 0.999였다. (p<0.05). 분할조사에 의한 준치사손상 회복정도는 약 4시간 내외에 포화상태에 도달하였으며 포화상태의 recovery ratio(RR)는 2에서 3.79 사이였다. RR은 방사선감수성의 지표인 SF2, ${\alpha}$, ${\beta}$, Do, $\v{D}$과 통계학적으로 유의한 상관관계를 나타내지 않았다. 결론 : 본 연구의 결과 네가지 인체상피암세포주의 내재적 발사선감수성은 서로 상이하였으며 Y-79가 가장 민감하였고, MKN-45와 HeLa는 각각 중등도의 방사선감수성을 나타냈으며 PC-14는 방사선감수성이 가장 낮았다. 이와같은 감수성의 차이는 SF2, ${\alpha}$, Do와 $\v{D}$의 차이로 나타났으며 띠들간에는 밀접한 상관관계를 나타내었다. 방사선에 의한 준치사손상 회복력은 MKN-45와 HeLa에서 높게 나타났고 회복력과 방사선감수성과는 무관하였다. 각 암세포주에 따르는 이와같은 지표들은 향후 방사선치료 효과를 높이기 위한 방사선생물학 실험의 기초 자료로서 이용되어 질 수 있을 것이다.