• 한국작물학회지
• /
• 제55권3호
• /
• pp.259-267
• /
• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• 한국작물학회지
• /
• 제64권4호
• /
• pp.406-413
• /
• 2019

기후변화에 대응하여 중부지역에서 콩 생산성 향상을 위해 적합한 품종선발과 대재적기 결정에 필요한 등숙 및 개화생태형 기초자료를 확보하고자 본 시험을 수행하였다. 시험재료는 조생종으로 큰올콩, TI196944, 중생종으로 선유콩, 중만생종으로 대원콩, 대풍2호 등 총 5품종이 사용되었다. 파종기는 6월 1일, 6월 20일, 7월 10일, 7월 20일 총 4회 파종하였다. 개화에 필요한 최소한의 소요일수 즉 기본 영양생장기간(BVP)은 조생종인 큰올콩이 27일, 중생종인 선유콩은 31일, 중만생종인 재원콩과 대풍2호는 36일 정도이었고, 적산온도는 5개 품종 평균적으로 볼 때 950℃ 정도이었다. 등숙율은 대풍2호를 제외하고 6월 1일 파종구가 가장 저조하였고, 대풍2호는 모든 파종시기의 등숙율이 90% 이상으로 높았다. 등숙율과 수량성을 고려할 때 중만생종인 대원콩과 대풍2호의 등숙적온은 25℃ 정도이었다. 대풍 2호의 다수성은 등숙기간이 길어 일사량 흡수가 증가하고 마디수와 동화물질 전류량이 증가하여 결과적으로 수량이 증수하는데 기인하는 것으로 분석되었다. 파종시기별 수량성은 북한도입 유전자원인 TI196944를 제외하고 나머지 국내육성 4품종은 6월 20일 파종구가 가장 높았으며, 7월 20일 파종의 경우 6월 20일 파종과 비교할 때 85~92% 수준이었다. 따라서 최근 우리나라 기상여건 상 5~6월의 상습적인 가뭄으로 파종시기를 놓치거나 출현율이 극히 저조할 경우, 중부평야지에서는 7월 20일까지 파종을 해도 경제적인 수준의 콩 생산이 가능할 것으로 판단된다.

• Journal of Chest Surgery
• /
• 제22권6호
• /
• pp.980-989
• /
• 1989

The Hancock porcine xenograft valves had been used in Seoul National University Hospital, mainly because of their antithrombogenicity despite of the predicted failure, from March 1976 to April 1984, and a total and consecutive 163 patients were retrospectively studied for late results with the special stress on the structural failure. The hospital mortality rate [within 30 days] was 6.1 %, and the 153 early survivors were followed up for a total of 822.9 patient-years [p-y][Mean * SD 5.38 * 3.02 years]. The linealized late mortality was 1.823%/p-y. Four major complications related to the Hancock valve were: 1.822% thromboembolism/p-y; 0.729 % bleeding/p-y; 0.972% endocarditis/p-y; 3.646% overall valve failure/p-y and 2.187 % primary tissue failure [PTF]/p-y. The actuarial survival rates at 5 and 10 years were 94.90 * 1.89% and 80.58 * 5.21 %; and the probabilities of freedom from thromboembolism at 5 and 10 years were 90.93 * 2.63% and 83.35 * 7.64 9o respectively. The probabilities from PTF at 5, 10 and 12 years were 98.02 * 1.39%, 60.62 * 8.89% and 49.60 * 12.34 %. One hundred-eighteen patients [72.4%] had single MVR [age, 34.0 * 10.9 years] with the operative mortality rate of 4.2%; and 113 early survivors were followed up for a total 616.4 patient-years[5.46 * 2.96 years]. The late mortality rate was 1.460 %/p-y. The major complications were: 1.622 % thromboembolism /p-y; 0.487% bleeding/p-y; 0.649 % endocarditis/p-y; 2.920% primary valve failure/p y and 1.785% PTF/p-y. The actuarial survival rates were 97.08 * 1.67%[at 5 years] and 81.27 * 6.64%[at 10 years], and the probabilities of freedom from thromboembolism 92.44 * 2.76 %[at 5 years] and 80.89 * 11.08%[at 10 years]. The probabilities of freedom from PTF at 5 and 10 years were 98 70 * 1.29% and 65.59 * 9.78% respectively. The mean age of 11 patients of PTF was 25.7 * 8.8 years and the valve extraction period 7.16 * 1.45 years. Failure of bioprosthetic xenograft valves are reportedly known to occur earlier in young patients in an accelerated fashion. The study with two groups divided into the cumulative younger and the cumulative older patients according to the age limits of 5-year interval strongly suggested these tendency. Although PTF began to occur past postoperative 5 years and the probabilities of freedom from PTF increased as the age limits raised and the number of patients increased in the cumulative younger patients while they decreased as the age limits lowered and the number of patients increased in the cumulative older patients, the definite age limits from which the Hancock valve can be safely recommended could not be obtained. From the results, the Hancock valves are contraindicated in patients younger than 20 to 25 years and may be safely recommended in patients older than 45 years as a tentative conclusion. Further longitudinal study may define these age factors.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.19-19
• /
• 2017

The indica ${\times}$ japonica rice (Oryza sativa L.) cultivars released in Japan since 1980 are high-yielding. However, occasionally in these cultivars their high yield potentials cannot be realized, particularly depending on climate conditions. The objectives of this study were to identify the reason for yield instability and the critical yield component factor causing lower grain yield in these high-yielding cultivars. Standard-yield japonica, high-yielding japonica-dominant, and indica-dominant cultivars were grown in western Japan. Rough grain yield (RY) in these high-yielding cultivars ranged from 450 to $980g\;m^{-2}$, and was positively correlated with potential grain yield (PRY). By fluctuations of solar radiation, RY changed with spikelet number (SNO), and SNO was correlated with cumulative radiation during the panicle formation period of 30 days before heading. Even if higher SNO was achieved under higher radiant conditions, RY was lower than PRY. The lower grain-filling in plants bearing higher SNO resulted from a lower filling percentage of spikelets (%F, RY/PRY), and %F was strongly correlated with spikelet fertility (%S) across all cultivars. %S was highly influenced by cumulative radiation per PRY during pollen development and establishment around heading. Inhibition of assimilation by leaf removal lowered %S. Conversely, stem thinning and removal of upper panicles around heading increased %S in spikelets of the lower part of the panicle in which sterility was higher. These results suggest that limitation of assimilate-supply due to low irradiance at the spikelet-formation and flowering stages restrains the potential of the high-yielding cultivars, depending on reduction of SNO and %S, respectively.

• 한국임상수의학회지
• /
• 제25권2호
• /
• pp.85-89
• /
• 2008

This study assessed the incidence of embryo and fetal loss following early pregnancy diagnosis using ultrasonography in dairy cows. A positive pregnancy was a recognition of the vesicle, embryo or fetus by ultrasonography. Seven hundreds and two pregnancies determined by ultrasonography following artificial insemination were divided into three groups according to the number of days diagnosed pregnant: early A group (27 to 40 days, n = 143), early B group (41 to 50 days, n = 172), or standard group (51 to 70 days, n = 387). Following a positive pregnancy diagnosis, embryo or fetal loss included all cows with observed abortions and cows found open after the positive pregnancy diagnosis. The incidence rate of embryo or fetal loss within 7 days after pregnancy diagnosis was 1.4, 0.6 and 0.3% for the early A, early B, and standard groups, respectively (P>0.05). The incidence of the embryo or fetal loss during 8 to 30 days after pregnancy diagnosis did not differ (P>0.05) among the early A (0%), early B (1.2%), and standard groups (1.0%). Furthermore, the cumulative incidence of the embryo or fetal loss before calving did not differ (P>0.05) among the early A (9.8%), early B (9.3%), and standard groups (5.9%). These results indicate that early pregnancy diagnosis using ultrasonography does not increase the risk of embryo and fetal loss compared with that of routine pregnancy diagnosis in dairy cows.

• 한국수산과학회지
• /
• 제41권1호
• /
• pp.20-25
• /
• 2008

The susceptibility of five different marine fish to iridovirus IVS-1 infection was analyzed and found a higher the cumulative mortality in the order of rock bream (Oplegnathus fasciatus), red sea bream (Pagrus major), sea perch (Lateolabrax sp.), rockfish (Sebastes schlegeli) and black porgy (Acanthopagrus schlegeli). However, the concentrations of virus in the infected spleens of these species did not differ significantly. To determine the release of iridovirus from infected fish into culturing seawater, rock bream were challenged with iridovirus IVS-1 and the concentration of virus in the water was analyzed using PCR. Over the 10 days of the analysis, the linear relationship between the number of dead fish and viral DNA concentration found in culturing seawater should be considered direct evidence of horizontal iridovirus transmission.

• 한국대기환경학회지
• /
• 제12권4호
• /
• pp.473-478
• /
• 1996

Using data observed from 1966 to 1994, long-term trends of visibility at 15:00 in Seoul and Chunchon were analyzed. Annual average visibility in Seoul has been decreased continuously. In particular, annual number of days for visibility more than 15km was remarkably reduced since 1980. Also, the trend of the visibility in Chunchon was similar to that of Seoul. But the variations were small to compare with Seoul. Long-term trends of relative humidity (RH) and specific humidity (q) at 15:00 in Seoul have been slightly decreased. Cumulative frequency distributions of visibility for ranges of RH (0 $\sim 50%, 50 \sim 60%, 60 \sim 70%, 70 \sim 80%, 80 \sim 90%, 90 \sim 100%$) at 15:00 in Seoul and Chunchon were generally decreased during the second period (1984 $\sim$ 1994) as compared with the first period (1973 $\sim$ 1983), except for the range of 90 to 100% RH. Despite of decreasing phenomena of RH, characteristics of urban climates in Seoul, visibility degraded due to an increase of air pollution.

• 한국임상수의학회지
• /
• 제24권3호
• /
• pp.337-341
• /
• 2007

This study determined the effect of postpartum intrauterine infusion of povidone-iodine solution on the subsequent reproductive performance in dairy cows. Six hundred and fifty-eight dairy cows that were around week 4 postpartum were randomly divided into two groups: (1) Cows in treated group received an intrauterine infusion of 100 to 150 ml 2% povidone-iodine solution (treated group, n=269), or (2) Cows that received no treatment were served as the controls (control group, n=389). The cows were bred at observed estrus more than 50 days after calving. Artificial insemination (AI) was done according to the a.m.-p.m. rule. The conception to AI was determined per rectum 60 days after AI by both ultrasonographical observation and manual palpation. The intervals from calving to first service and conception ($94.2{\pm}2.7$ and $144.1{\pm}4.1$ days vs. $88.0{\pm,}2.1$ and $143.5{\pm}4.6$ days, respectively), number of services per conception ($2.0{\pm}0.1$ vs. $2.1{\pm}0.1$), and cumulative pregnancy rates within 90 and 150 days postpartum (31.9 and 61.7% vs. 29.7 and 62.1%) did not differ between the control and treated groups (P>0.05), while conception rate at first service was lower (P<0.05) in the treated group (40.5%) than in the control group (49.4%). Additionally, we could not find any effect of intrauterine infusion of povidone-iodine solution according to cow parity or calving season on the reproductive performance. These results indicate that intrauterine infusion of povidone-iodine solution at week 4 postpartum does not affect the subsequent reproductive performance in dairy cows.

• Animal cells and systems
• /
• 제2권2호
• /
• pp.217-222
• /
• 1998

Green peach aphid, Myzus persicae(Sulzer) (Homoptera: Aphididae), interacts with many predatory insects in potato fields during the summer. The concept of the predator complex associated with green peach aphids was applied to explain the interactions between the aphid and its predators. The predator power of the predator complex was determined by two factors: the number of predators and the relative feeding capacity. The dynamics of the green peach aphid population was expressed by the number of individuals while the predator power was used to characterize the predator complex. Cumulative degree-days for green peach aphids were used as a time scale to analyze phonology and dynamics patterns of the aphid and its predator complex. The patterns of population changes in aphids were similar during the period of study(1993-1995) although the highest density of aphids fluctuated significantly from year to year. However, the predator power appeared more stable than the green peach aphid population over the three year period. The results indicated that the predator complex plays an important role to suppress the aphid populations during the latter part of the season and that the applications of control measures for green peach aphids in between the initiation and the peak timing of aphid populations are critical to minimize the damage on potatoes.

• 한국수산과학회지
• /
• 제44권4호
• /
• pp.352-358
• /
• 2011

The presence of ISKNV-like viruses in various freshwater ornamental fish species imported from Asia was confirmed by polymerase chain reaction(PCR) amplification of the ATPase(adenosine triphosphatase) gene. Interestingly, molecular analyses of the Open Reading Frame 25(ORF25) region of these isolates based on the ISKNV(Infectious spleen and kidney necrosis virus) genome revealed the presence of various repetitive sequences. ORF25 repeat sequence length had no effect on cumulative mortality of rock bream Oplegnathus fasciatus challenged with tissue homogenates of infected pearl gourami, Trichogaster leeri; silver gourami, Trichogaster microlepis; blue gourami, or Trichogaster trichopterus. All isolates induce cumulative mortalities after 12 days of infection, confirming that ORF25 polymorphism did not affect the pathogenicity of ornamental fish megalocytiviruses that cross infect rock bream, a seawater fish. Also, no statistically significant differences in spleen index or viral copy number in infected tissues was detected between isolates with varying ORF25 repeat sequence lengths. However, further studies are necessary to fully characterize the functional characteristics of these polymorphisms in megalocytivirus disease in ornamental fishes.