• Journal of Preventive Medicine and Public Health
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• 제53권2호
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• pp.67-69
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• 2020

Controversy remains over whether the coronavirus disease 2019 (COVID-19) virus may have infectivity during the incubation period before the onset of symptoms. The author had the opportunity to examine the infectivity of COVID-19 during the incubation period by conducting an epidemiological survey on a confirmed patient who had visited Jeju Island during the incubation period. The epidemiological findings support the claim that the COVID-19 virus does not have infectivity during the incubation period.

• Ocean and Polar Research
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• 제30권1호
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• pp.11-19
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• 2008

Incubation routine and sex role of Streaked Shearwaters Calonectris leucomelas at Sasudo Island, in Jeju, South Korea, were studied during the incubation period, June to August in 2002. Incubation routine in Procellariiformes represents a sequence of alternating shifts taken in turn by female and male in a species-specific pattern. Hence, coordination of individual incubation rhythms between partners is crucial for successful breeding attempt. In Streaked Shearwaters, incubation routine represents a sequence of alternating shifts taken in turn by male and female. The first incubation shift was made by male after female had laid the egg. The mean incubation period was 50.8 days until hatching. Males had spent on average 26.5 days incubating and females 24.3 days accordingly. The mean duration of incubation shifts decreased progressively from 6th and 7th shift to hatching. Overall, males had spent more time incubating than females during the incubation period, but the mean duration of the incubation shift 5.6 days for males and 5.7 days for females did not differ between males and females. There were no effect of the body size of the breeding pair on incubation performance. For males the mean of body weight decreased during the incubation, whereas for females it remained approximately stable. In Streaked Shearwaters, the duration of incubation shift and subsequent foraging trip are related to loss of body weight during the period of fasting. In addition, coordination of individual incubation rhythms affects their incubation behaviour.

• 생태와환경
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• 제38권spc호
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• pp.22-26
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• 2005

Egg incubation periods of 14 species of plecoptera were examined at $10^{\circ}\;{\sim}\;11^{\circ}C$, $15^{\circ}\;{\sim}\;16^{\circ}C$, $20^{\circ}C$, and $23^{\circ}C$ under dark conditions. The total effective temperature (TET) was calculated by multiplying mean egg incubation days and water temperature of incubation periods. The relation between the TET and the incubation temperature was used to compare the life cycle of respective species. Perlodid species had higher TET values with a positive relation to incubation temperature than those of other species. Perlid species had low TET values in the 14 species with negative to variable relation, and Chloroperlid species showed variable to positive relations to incubation temperature. These results suggest that the relation between the TET and the water temperature reflected on their habitat of respective species.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.752-757
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• 1999

Studies were made of digestion of timothy (Pheleum pretense) hay, tall fescue (Festuca elatior) hay, and rice (Oryza sativa) straw in pure cultures of rumen anaerobic fungus, Neocallimastix frontails MCH3. The fungus was inoculated on ground forages (1%, w/v) in an anaerobic medium and incubated at $39^{\circ}C$. Incubation was continued for 24, 48, 72 and 96 h. The losses of dry matter, xylose and glucose of forage during incubation were determined at the end of these incubation periods. Xylose and glucose were considered to be released from xylan and cellulose, respectively. The digested xylan to digested cellulose (X/C) ratios of the substrate were calculated. Xylanase and carboxymethyl cellulose (CMCase) of culture supernatant and residual substrate was measured at the same time. The X/C ratios in the cultures on timothy hay and rice straw were greater than 0.5 in the first 24-h incubation period. The values were smaller than 0.3 in tall fesque. The ratio of xylanase activity to that of CMCase in the first 24-h incubation period correlated well with the traits in X/C ratio. However xylanase activity was still superior to CMCase in the following incubation period (48 to 96 h), although the glucose (designated as cellulose) was more intensively digested than xylose (designated as xylan). The production of these polysaccharidases appeared to correlate with substrate cell-wall sugar composition, xylose to glucose ratios, at the beginning of fast growing period.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.541-544
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• 1992

Duck eggs from Indigenous (desi), Khaki Campbell and Crossbred (Indian Runner $\times$ Khaki Campbell, $F_1$) were incubated to investigate fertility, hatchability and other related traits. The fertility was highest in crossbred followed by Khaki Campbell and Indigenous ducks respectively. The embryonic mortality was highest in Khaki Campbell followed by Indigenous and crossbred respectively. The embryonic mortality was higher in eggs of 7 days pre-incubation holding period and lower in eggs of 3 days pre-incubation holding period. A significant positive correlation was found between temperature and embryonic mortality as well as relative humidity and embryonic mortality. The hatchability on fertile eggs was highest in crossbred ducks and almost similar in both Khaki Campbell and Indigenous ducks. The hatchability was higher in eggs stored for 3 days in comparison with that of 7 days pre-incubation holding period. A negative correlation was found between temperature and hatchability as well as humidity and hatchability. The normal ducklings hatched out from the eggs of Khaki Campbell ducks was highest followed by Indigenous and crossbred respectively. There was a negative correlation between temperature and normal ducklings hatched as well as relative humidity and normal ducklings hatched. The preincubation holding temperature and relative humidity had positive correlation with dead-in-shell.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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• pp.237-241
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• 2004

In standard time-to-event or survival analysis, the occurrence times of the event of interest are observed exactly or are right-censored. However in certain situations such as the AIDS data, the incubation period which is the time between HIV infection time and the diagnosis of AIDS is usually doubly censored. That is the HIV infection time Is interval censored and also the time of the diagnosis of AIDS is right censored. In this paper, we Impute the Interval censored infection time using the conditional mean imputation and estimate the coefficient factor of the regression analysis for the incubation period using Gibbs sampler. We applied parametric and semi-parametric methods for the analysis of the Incubation period and compared the results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.471-475
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• 2000

P-type (100) Si wafer patterned with 1000$\AA$ SiO$_2$island was used as substrate and the Si films were deposited under low pressure using Si$_2$H$_{6}$-H$_2$gas mixture where the total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layer of the 350~1050$\AA$ thickness. In order to extend the incubation period, we kept high pressure H$_2$ environment without Si$_2$H$_{6}$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.iod.

• 한국버섯학회지
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• 제13권3호
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• pp.223-227
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• 2015

느타리버섯 '수한 1호'와 '곤지 7호'품종의 균사배양중 후배양 기간과 온도처리가 발이 균일도 및 생육에 미치는 영향을 조사한 결과는 다음과 같다. 배양중 전배양 $20^{\circ}C$, 20일 동안에는 두 품종 모두 11~15일에 $24{\sim}26^{\circ}C$까지 배지 내 온도가 상승되었다가 21일부터 후배양 온도처리와 동일한 수준으로 배지 내 온도가 유지되었다. 또한, 배지내 온도가 가장 높게 상승되는 시점에서 '수한 1호'의 $CO_2$는 6,500 ppm, '곤지 7호'는 5,800 ppm까지 발생되었으며 배양중인 균사생장에는 영향이 거의 없었다. '수한 1호'의 후배양 온도 $26^{\circ}C$에서 10일, 15일간 처리시 측발이율이 대조대비 40%, 비상품화율은 10.5% 감소 되었으며, '곤지 7호'는 후배양 온도 $26^{\circ}C$, 후배양 10일 처리에서만 측발이율은 19%, 비상품화율은 9.5% 감소되었다. 따라서, 느타리버섯 두 품종의 후배양 적합온도는 $26^{\circ}C$, 적합 후배양 처리기간은 '수한 1호'는 10일, 15일, '곤지 7호'는 10일이 발이 균일도가 높았다.

• Communications for Statistical Applications and Methods
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• 제21권6호
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• pp.487-500
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• 2014

A new method to calculate the transmittable prevalence of an epidemic disease is proposed based on a back-calculation formula. We calculated the probabilities of reactivation and of parasitemia as well as transmittable prevalence (the number of persons with parasitemia in the incubation period) of malaria in South Korea using incidence of 12 years(2001-2012). For this computation, a new probability function of transmittable condition is obtained. The probability of reactivation is estimated by the least squares method for the back-calculated longterm incubation period. The probability of parasitemia is calculated by a convolution of the survival function of the short-term incubation function and the probability of reactivation. Transmittable prevalence is computed by a convolution of the infected numbers and the probabilities of transmission. Confidence intervals are calculated using the parametric bootstrap method. The method proposed is applicable to other epidemic diseases in other countries where incidence and a long incubation period are available. We found the estimated transmittable prevalence in South Korea was concentrated in the summer with 276 cases on a peak at the $31^{st}$ week and with about a 60% reduction in the peak from the naive prevalence. The statistics of transmittable prevalence can be used for malaria prevention programs and to select blood transfusion donors.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1161-1170
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• 2000

Objective : The transverse hippocampal slice is one of the most commonly studied in vitro models of mammalian brain physiology. However, despite its broad usage, there has been no standardization of slice preparation techniques or recording condition. It is well known that variations in recording conditions can result in profound different effects to neuronal responses. Evoked field potentials, recorded extracellularly, were used to investigate the effects of variations in hippocampal slice preparation protocol on hypoxia responses of CA1 neurones. Material & Methods : Before hypoxic injury, hippocampal slices were incubated for 4 hours. During incubation period, the slices were placed in a incubation chamber($21^{\circ}C$) for recovery from preparation injury and then transferred to recording chamber($34^{\circ}C$) for more recovery and baseline electric recording with current stimulation(0.1Hz). Various time periods in incubation chamber and recording chamber were applied to each experimental group(group 1=60min : 180min, group 2=90min : 150min, group 3=180min : 60min, time in incubation chamber : time in recording chamber) before 10 min hypoxia produced by replacing 95% $O_2$+5% $CO_2$ mixed gas to 95% $N_2$+5% $CO_2$ gas. Calcium, Magnesium ions and several drugs effecting on glutamate receptor also were studied. Recoveries from hypoxic injury of hippocampal slices were estimated by percent recovery of population spike(PS). Statistic analysis of study were performed using paired t-test. Results : The percent recovery of PS after 10min hypoxia was considerably enhanced by increasing the period of current stimulation during incubation period before hypoxic injury. Temperature effect on the result of this experiment was also studied(group 4) but the result from this showed no statistic significance. Low magnesium ion concentration of artificial CSF(Mg-free aCSF) during incubation period enhanced the recovery of PS but low calcium (calcium-free) and high magnesium ion concentration(2mM) reduced it after hypoxic injury. L-glutamate($100{\mu}M$) and AP-5($50{\mu}M$) had no effect on the recovery of PS but CNQX($10{\mu}M$) in artificial CSF during incubation period markedly enhanced the recovery of PS. Co-treatment of AP-5($50{\mu}M$), CNQX($10{\mu}M$) and high magnesium concentration(2mM) enhanced recovery of PS in immediate following period of hypoxic injury but the effect of cotreatment after then decayed rapidly and lost statistic significance. Conclusions : Judging from above results, the condition of baseline recording is important in observing the recovery of population spike after hypoxia, and the time and the condition should be controled more strictly to obtain reliable results.