• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1C
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• pp.1-7
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• 2010

In this paper, the performance of the soft-decision-and-forward (SDF) protocol in the cooperative communication network with one source, one relay, and one destination, where each node has two transmit and receive antennas, is analyzed in terms of the bit error rate (BER) obtained from the pairwise error probability (PEP). For the slow-varying Rayleigh fading channel, the optimal and suboptimal power allocation ratios are determined without feedback. The optimal power allocation can be obtained by minimizing the average PEP. For the tractability, an alternative strategy of maximizing the product SNR of direct and relay links, which we call the suboptimal power allocation, is considered. Through the numerical analysis, we show that the performance gap between the suboptimal and the optimal power allocation is negligible in the high SNR region.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.285-293
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• 2013

Leaf samples of Solanum lycopersicum, Capsicum annuum, Cucurbita moschata, Cucurbita pepo, Sechium edule and Erythrina spp. were collected. All samples were positive for begomoviruses using polymerase chain reaction and degenerate primers. A sequence of ~1,100 bp was obtained from the genomic component DNA-A of 14 samples. In addition, one sequence of ~580 bp corresponding to the coat protein (AV1) was obtained from a chayote (S. edule) leaf sample. The presence of Squash yellow mild mottle virus (SYMMoV) and Pepper golden mosaic virus (PepGMV) were confirmed. The host range reported for SYMMoV includes species of the Cucurbitaceae, Caricaceae and Fabaceae families. This report extends the host range of SYMMoV to include the Solanaceae family, and extends the host range of PepGMV to include C. moschata, C. pepo and the Fabaceae Erythrina spp. This is the first report of a begomovirus (PepGMV) infecting chayote in the Western Hemisphere.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.131-136
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• 2016

Marine organisms are sources of many bioactive compounds, such as essential fatty acids, essential amino acids, vitamins, and minerals, making them useful candidates for the production of safe bioactive substances. They also synthesize glutamic acid, which can be used to produce γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system (CNS), via fermentation with Lactobacillus brevis BJ-20. This study investigated the degree to which fermented sea tangle (FST) inhibits enzymes such as acetylcholine esterase (AChE) and prolyl endopeptidase (PEP) and affects memory of normal mice using the T-maze test. FST inhibited more than 90% of AChE at 1 mg/mL and 50% of PEP at 8 mg/mL. Oral FST (100 mg/kg) significantly improved performance of normal mice on the T-maze. Therefore, sea tangle fermented with L. brevis BJ20 effectively contributes to memory improvement and might be a useful functional food ingredient.

• Research in Plant Disease
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• v.24 no.1
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• pp.66-74
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• 2018

Field surveys to investigate the incidence and occurrence pattern of viruses in red pepper were conducted during 2015-2016 in Korea. A total of 424 samples in 2015 and 368 samples in 2016 were collected based on selection of plants showing symptoms from farmer's field from every June to September. Reverse transcription-Polymerase chain reaction was used to test all samples for the presence of one or more of following viruses: Cucumber mosaic virus (CMV), Broad bean wilt virus 2 (BBWV2), Tomato spotted wilt virus (TSWV), Beet western yellows virus (BWYV), Pepper mottle virus (PepMoV), Potato virus Y (PVY) and Pepper mild mottle virus (PMMoV). The average disease incidence was 91.7% in 2015 and 98% in 2016 and the all seven viruses were found although there were different kinds of regions. The percent virus incidence in collected samples during 2015 was as follows: CMV, 73.8%; BBWV2, 68.3%; BWYV, 46.9%; PMMoV, 14.6%; TSWV, 12.7%; PepMoV, 6.6% and PVY, 3.3%. For 2016, incidence was as follows: CMV, 73.3%; BBWV2, 71.4%; BWYV, 34.7%; TSWV, 27.9%, PMMoV, 19.2%; PepMoV, 13.5% and PVY, 3.5%. Mixed infections were prevalent over single infections and infection rate was 83% and 86.7% in 2015 and 2016, respectively.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.123-131
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• 2015

In this study, viral disease samples were obtained between 2006 and 2010 from pepper fields in 11 major pepper-growing districts in Gangwon-do, and in 83 areas from other provinces, with the exception of Gyeongsangnam-do and Jeju island in Korea. In order to assess the type of infection, field surveys were conducted with regard to viral disease severity and virus type, based on typical symptoms on leaves. The means of single and mixed-virus infections were 46.6% and 48.0%, respectively, during those periods, suggesting that viruses are the agents that most severely decrease pepper production in field cultivation in Korea. In terms of single infection, Cucumber mosaic virus (CMV) was the most prevalent virus based on its disease severity ratings (34.8%). Next, Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) were shown to cause severe viral diseases in pepper, with disease severities of around 5-10%. On the other hand, Tomato spotted wilt virus (TSWV) occurs in a limited area in Chungcheongnam-do and Jeollanam-do. Thus, the viral disease caused by CMV, PMMoV, and PepMoV in pepper can be severe, and these virus types should remain considered critical reasons for decreased pepper production in field cultivation in Korea. In addition to single infection, mixed infections are frequently observed in collected pepper samples from all areas. The ratios of mixed infection were therefore studied to evaluate the disease severity of mixed infections and to define individual virus types. These data showed that different types of viruses were present, and CMV was the most abundant virus for mixed infection, as in the case of single infection. Among mixed infections, the highest disease severity was seen with CMV+Broad beam wilt virus 2 (BBWV2), followed by other types of mixed infection such as CMV+PepMoV and CMV+PMMoV. However, further work is needed to reduce the severe damage caused by viruses and to assess mixed infection types involving three or more viruses.

• The Korean Journal of Food And Nutrition
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• v.4 no.2
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• pp.161-166
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• 1991

The blocked N-terminus and N-terminal sequence of soybean B-amylase were aetermined by analyzing the acidic peptides derived on peptic digestion of the enzyme. The acidic peptides were separated from the digest on a Dowex 50$\times$2 column(1X5cm) and purified by reversed phase-high performance liquid chromatography(RP-HPLC). The major acidic peptide, PEP-1, was a heptapeptlde. The N-terminal 7 amino acid sequence of soybean B-amylase was deduced to be acetyl-Ala-Thf-Ser-Asp-Ser-Asn-Met- from the results of sequence analysis of PEP-1 and amino acid analysis of other acidic peptides.

• BMB Reports
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• v.42 no.3
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• pp.136-141
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• 2009

Familial Amyotrophic lateral sclerosis (FALS) is a progressive neurodegenetative disorder induced by mutations of the SOD1 gene. Heat shock protein 27 (HSP27) is well-defined as a stress-inducible protein, however the its role in ALS protection has not yet been established. To investigate the role HSP27 may have in SOD1 mutant-mediated apoptosis, human SOD1 or HSP27 genes were fused with a PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame fusion protein, which was then transduced into cells. We found the purified PEP-1-HSP27 fusion proteins can be transduced efficiently into neuronal cells and protect against cell death by enhancing mutant SOD1 activity. Moreover, transduced PEP-1-HSP27 efficiently prevents protein aggregation produced by oxidative stress. These results suggest that transduced HSP27 fusion protein may be explored as a potential therapeutic agent for FALS patients.

• Asian Journal of Turfgrass Science
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• v.8 no.1
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• pp.13-18
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• 1994

$CO_2$와 질소동화작용에 있어서의 잎과 줄기간의 세포간 관계가 잔디군락의 자연 환경 상태하에서 자라는 Portulaca oleracea 에서 조사되었다. 기공이 줄기에서는 관찰되지 않는 반면 잎에서는 $1cm^2$당 3,275개가 나타났다. 어린 쇠비름 잎의 기공의 조헝운 범에누누 높고 낮에는 낮다. 최고 활성을 갖는 마디의 순서는 위에서 아래로 떨어짐에 따라 변화한다.P.oleracea 의 줄기조직은 CMA의 최고 활성을 나타내었으나 잎에서는 CMA의 활성이 나타나지 않았다. 빠른 산의 성화는 새벽에 원줄기에서 보여지나 줄기는 서서히 증가하는 것 밖에 관찰되지 않는다. RuPB carboxy-lase의 활성은 거의 관찰 되지 않는다. 특히 잎새에서의 PEP carboxylase의 활성은 이른 아침에 줄기에서는 낮고 잎에서는 매우 높음을 보여준다. 이런 결과는 새벽에 열려진 기공을 통과할$CO_2$가 PEP carboxylase에 의해 잎에서 동화되고 $C_4$생산물이 줄기로 이동함을 나타낸다. Nitrate 축적과 nitrate reductase, nitrite reductase, glutamine symithetase, gluamate symthase, glutamade dehydrogenase의 농도는 잎보다 줄기에서 더 높았고 밤보다 낮에 더 높다. 이것은 뿌리를 통해 흡수된 nitrate의 상당한 양이 줄기에서 동화되고 줄기 조직을 통해 잎으로 이동되어 거기에서 감소된다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.9
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• pp.16-23
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• 2009

In this paper, we propose a new distributed Alamouti space-time block coding scheme using cooperative relay system composed of one source node, three relay nodes and one destination node. The source node is assumed to be equipped with two antennas which respectively use a 2-beam array to communicate with two nodes selected from the three relay nodes. During the first time slot, the two signals which respectively were transmitted by one antenna at the source, are selected by one relay node, added, amplified, and forwarded to the destination. During the second time slot, the other two relay nodes implement the conjugate and minusconjugate operations to the two received signals, respectively, each in turn is amplified and forwarded to the destination node. This transmission scheme represents a new distributed Alamouti space-time block code that can be constructed at the relay-destination channel. Through an equivalent matrix expression of symbols, we analyze the performance of this proposed space-time block code in terms of the chernoff upper bound pairwise error probability (PEP). In addition, we evaluate the effect of the coefficient $\alpha$ ($0{\leq}{\alpha}{\leq}1$) determined by power allocation between the two antennas at the source on the received signal performance. Through computer simulation, we show that the received signals at the three relays have same variance only when the value of $\alpha$ is equal to $\frac{2}{3}$, as a consequence, a better performance is obtained at the destination. These analysis results show that the proposed scheme outperforms conventional proposed schemes in terms of diversity gain, PEP and the complexity of relay nodes.

• Pediatric Infection and Vaccine
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• v.23 no.3
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• pp.180-187
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• 2016

Purpose: This study described the post-exposure prophylaxis (PEP) and secondary varicella infection in children inadvertently exposed to varicella zoster virus (VZV) in the hospital. Methods: We retrospectively analyzed data from patients with VZV infection who were initially not properly isolated, as well as children exposed to VZV at the Seoul National University Children's Hospital between January 2010 and December 2015. The PEP measures were determined by the presence of immunity to VZV and immunocompromising conditions. Patient clinical information was reviewed via medical records. Results: Among 147 children hospitalized between 2010 and 2015, 13 inadvertent exposures were notified due to VZV infection. Five index children had a history of VZV vaccination. Eighty-six children were exposed in multi-occupancy rooms and 62.8% (54/86) were immune to VZV. The PEP measures administered to 27 exposed patients included varicella zoster immunoglobulin and VZV vaccination. Four children developed secondary varicella, which was linked to a single index patient, including one child who did not receive PEP and three of the 27 children who received PEP. The rates of secondary varicella and prophylaxis failure were 4.7% (4/85) and 11.1% (3/27), respectively. The secondary varicella rates were 1.9% (1/54) and 9.7% (3/31) among immunocompetent and immunocompromised children, respectively. Conclusions: Delayed diagnosis of VZV infection can lead to unexpected exposure and place susceptible children and immunocompromised patients at risk for developing varicella. The appropriateness of the current PEP strategy based on VZV immunity may require re-evaluation.