• Research in Plant Disease
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• v.25 no.4
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• pp.157-163
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• 2019

This study aimed to assess the incidence and distribution of toxigenic fungi in Korean oat. Toxigenic fungi were isolated from oat samples collected from 12 oat fields from heading to harvest in 2017 and 2018. A total of 745 fungal colonies were isolated based on morphology and identified using marker genes. About 92% of the fungal isolates were Fusarium spp. and others were Penicillium (5.9%) and Aspergillus (2.1%). Fusarium isolates comprised mostly of F. asiaticum (83.1%), followed by F. incarnatum (5.4%), F. proliferatum (3.5%), F. fujikuroi (2.8%), F. tricinctum species complex (FTSC) 11 (1.5%) and F. graminearum (1.0%). About 97% of F. asiaticum was nivalenol type, and 3-acetyl deoxynivalenol (3.2%) and 15-acetyl deoxynivalenol (0.4%) types also were found. Pathogenicity test of the selected Fusarium isolates revealed that F. asiaticum isolates have a wide range of virulence depending on the tested plants. F. graminearum and FTSC 11 isolates from blighted spikelets were the most virulent in naked oat. All Fusarium isolates (n=18) except one (FTSC 11) produced nivalenol (0.2-7.6 ㎍/g), deoxynivalenol (0.03-6.1 ㎍/g), and zearalenone (0.1-27.0 ㎍/g) on rice medium. This study is first report that F. asiaticum causes Fusarium head blight disease of oat in Korea. These findings demonstrate the dominance of F. asiaticum in oat agroecosystems as in rice, wheat and barley in Korea.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.18-26
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• 2013

This study suggested techniques to reduce burning rate and their effects for the AP thermoplastic composite propellant. Burning rate obtained through ground tests using a small size motor were analyzed to investigate the effects of AP particle size and LiF of 0.5~2.0% on the inhibition reaction for the PEBAX/AP thermoplastic propellant. The results showed that utilization of large size particle of AP and addition of LiF under 2.0% can reduce the burning rate sufficiently and their quantitative effects were suggested in this paper.

• Research in Plant Disease
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• v.25 no.4
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• pp.213-219
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• 2019

A total of 1,159 Fusarium strains were isolated from sorghum grown in Danyang and Youngwol in 2017 and 2018. The isolates were analyzed to reveal genetic, toxigenic and pathogenic characteristics. Phylogenetic analysis using TEF-1α and RPB2 genes showed that the samples were contaminated with at least 17 Fusarium species. Among them, F. graminearum, F. proliferatum, F. thapsinum, F. incarnatum, and F. asiaticum were dominant species. In F. graminearum and F. asiaticum, F. graminearum-15-acetyl deoxynivalenol chemotype and F. asiaticum-nivalenol chemotype were frequent. Six Fusarium species tested produced one or more mycotoxins, except F. thapsinum and FTSC 11. F. proliferatum and F. fujikuroi had FUM1 gene (76.0% and 81.6%, respectively) and some isolates produced high level of fumonisin (over 1,000 ㎍). F. proliferatum and F. thapsinum were more virulent than other species on sorghum. These results indicate that Fusarium species in sorghum might produce multiple mycotoxins.

• Phonetics and Speech Sciences
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• v.8 no.1
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• pp.25-36
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• 2016

Previous studies showed that the voice onset time (VOT) of aspirated and lenis stops has been merged, and post-stop fundamental frequency (F0) has emerged as a primary cue to distinguish the two stops in the younger generation and female speech. The purpose of this study is to demonstrate that VOT merger in aspirated and lenis stops occurs after an F0 difference between the two stops becomes stabilized. In other words, unless post-stop F0, which is a redundant feature, is fully developed, it is hard for VOT merger to happen. Females have got a stable F0 difference in stops earlier than males. Therefore, VOT merger could happen, and as a result, females could take the lead in changing from VOT to F0 in initial stops. This study also shows that speakers who acquired F0 as a primary cue use F0 to the full to distinguish lenis stops from two other stops (aspirated and fortis).

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.31-38
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• 2007

Population ecological parameters and stock biomass of the purplish washington clam, Saxidomus purpuratus (Sowerby), in the southern coastal areas of Korea were determined based on the fishery data from the Divers Fisheries Cooperative and other available biological data. Instantaneous coefficient of total mortality (Z) of purplish Washington clam was estimated to be 0.7479/year. The estimated instantaneous coefficient of natural mortality (M) was 0.2012/year. From the values of Z and M, the instantaneous coefficient of fishing mortality coefficient (F) for the recent years was calculated to be 0.4578/year. The age of purplish Washington clam at its first capture ($t_c$) was 2.7506 year. Yield-per-recruit and spawning biomass-per-recruit were estimated under harvest strategies that bases on $F_{max}$, $F_{0.1}$, $F_{35%}$ and $F_{40%}$ were shown as 81.60 g, 61.68 g, 115.07 g and 131.51 g, respectively. The acceptable biological catch (ABC) was estimated to be about 1,404 metric tons.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.9 s.339
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• pp.1-8
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• 2005

A $0.35\mu$m SiGe BiCMOS fabrication process has been timely developed, which is aiming at wireless RF ICs development and fast growing SiGe RF market. With non-selective SiGe epilayer, SiGe HBTs in this process used trapezoidal Ge base profile for the enhanced AC performance via Ge induced bandgap niuoin. The characteristics of hFE 100, $f_{T}\;45GHz,\;F_{max}\;50GHz,\;NF_{min}\;0.8dB$ have been obtained by optimizing not only SiGe base profile but also RTA condition after emitter polysilicon deposition, which enables the SiGe technology competition against the worldwide cutting edge SiGe BiCMOS technology. In addition, the process incorporates the CMOS logic, which is fully compatible with $0.35\mu$m pure logic technology. High Q passive elements are also provided for high precision analog circuit designs, and their quality factors of W(1pF) and inductor(2nH) are 80, 12.5, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.33-39
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• 1998

Survival, growth and reproduction of the cigarette beetle, Lasiodema sewicome F., were studied on flue-cured (NC82), air-cured (Br.21), aromatic (Izmir) tobacco and artificial diet (wheat feed 95% + yeast 5%). Cigarette beetle adults occurred from first generation in the flue-cured and aromatic tobacco, but no adults emerged in air-cured tobacco after the 2nd generations. The head capsule widths of larvae of the cigarette beetles L sewicome F.1 reared on different diets at 2$0^{\circ}C$, $25^{\circ}C$ and 3$0^{\circ}C$ were measured. The head capsule development was slower at 2$0^{\circ}C$ on the same diets than $25^{\circ}C$ and 3$0^{\circ}C$, and slower in the flue-cured and aromatic tobacco than the artificial diet at 2$0^{\circ}C$ and 2S$^{\circ}C$, At $25^{\circ}C$ the larval head capsule developed more rapidly in the aromatic tobacco than the flue-cured tobacco. However, no larval head development was noticed in the air-cured tobacco. The correlation between population densities of cigarette beetle,1 sewicome F., and sugar content of tobacco leaves was positive, but negative in nicotine contents. The regression between densities and sugar content was Y : 22.79 X + 57.29 (r=0.891**), and between nicotine content was Y : -141.31X + 321.40(r=-0.917**).

• BMB Reports
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• v.34 no.6
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• pp.573-577
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• 2001

The mammalian heart is known to undergo significant mechanical changes during fetal and neonatal development. The objective of this study was to define the ontogeny of the ryanodine receptor/$Ca^{2+}$ release channel and SERCA that play the major roles in excitation-contraction coupling. Whole ventricular homogenates of fetal (F) (19 and 22 days in gestation), postnatal (N) (1 and 7 days postnatal), and adult (A) (5 weeks postnatal) Sprague-Dawley rat hearts were used to study [$^3H$]ryanodine binding and oxalate-supported $^{45}Ca^{2+}$ uptake. For the ryanodine receptor, the major findings were: (1) The ryanodine receptor density, as determined by maximal [$^3H$]ryanodine binding ($B_{max}$), increased 3 fold between the F22 and A periods ($0.26{\pm}0.1$ vs. $0.73{\pm}0.07$ pmoles/mg protein, p<0.01), whereas there was no significant change during the F22 and N1 development phases ($0.26{\pm}0.1$ vs. $0.34{\pm}0.01$). (2) Affinity of the ryanodine receptor to ryanodine did not significantly change, as suggested by the lack of change in the $K_d$ during the development and maturation. For SERCA, changes started early with an increased rate of $Ca^{2+}$ uptake in the fetal periods (F19: $8.1{\pm}1.1$ vs. F22: $19.3{\pm}2.2$ nmoles/g protein/min; p<0.05) and peaked by 7 days (N7) of the postnatal age ($34.9{\pm}2.1$). Thus, we conclude that the quantitative changes occur in the ryanodine receptor during myocardial development. Also, the maturation of the $Ca^{2+}$ uptake appears to start earlier than that of the $Ca^{2+}$ release.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.248-256
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• 2018

O-2-$^{18}F$-fluoroethyl-l-tyrosine ($[^{18}F]FET$) has been widely used for glioblastomas (GBM) in clinical practice, although evaluation of its applicability in non-clinical research is still lacking. The objective of this study was to examine the value of $[^{18}F]FET$ for treatment evaluation and prognosis prediction of anti-angiogenic drug in an orthotopic mouse model of GBM. Human U87MG cells were implanted into nude mice and then bevacizumab, a representative anti-angiogenic drug, was administered. We monitored the effect of anti-angiogenic agents using multiple imaging modalities, including bioluminescence imaging (BLI), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT). Among these imaging methods analyzed, only $[^{18}F]FET$ uptake showed a statistically significant decrease in the treatment group compared to the control group (P=0.02 and P=0.03 at 5 and 20 mg/kg, respectively). This indicates that $[^{18}F]FET$ PET is a sensitive method to monitor the response of GBM bearing mice to anti-angiogenic drug. Moreover, $[^{18}F]FET$ uptake was confirmed to be a significant parameter for predicting the prognosis of anti-angiogenic drug (P=0.041 and P=0.007, on Days 7 and 12, respectively, on Pearson's correlation; P=0.048 and P=0.030, on Days 7 and 12, respectively, on Cox regression analysis). However, results of BLI or MRI were not significantly associated with survival time. In conclusion, this study suggests that $[^{18}F]FET$ PET imaging is a pertinent imaging modality for sensitive monitoring and accurate prediction of treatment response to anti-angiogenic agents in an orthotopic model of GBM.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.111-117
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• 1998

This study was conducted to examine the effect of culture supernatant of bovine oviductal epithelial cell(BOEC) on in vitro development of mouse embryos. To obtain the culture supernatant, ampullary epithelial cell, ithmic epithelial cell and ciliated eptithelial cell of bovine oviduct were cultured in Ham's F-10 su, pp.emented with 10% FCS. The development rates of mouse embryos to blastocyst stage were significantly(P<0.05) higher in BOEC-culture supernatant(72.3∼82.3%) than in Ham's F-10(50.7%). The proportions of embryonic development into hatched blastocysts were significantly(P<0.05) higher in ampullary cell supernatant(43.2%), ithmic cell supernatant(48.4%) and ciliated cell supernatant (27.7%) than in Ham's F-10(14.4%). On the other hand, the effect of ciliated cell supernatant was lower than those of other cell supernatants(P<0.05). And there was no difference between ampullary cell supernatant and ithmic cell supernatnat.