• Parasites, Hosts and Diseases
• /
• v.40 no.3
• /
• pp.139-148
• /
• 2002

In order to study the range of flight and feeding activity of Anopheles sinensis, the dispersal experiment was conducted in Paju city, located in the northern part of Gyeonggi-do, Republic of Korea, during the period of 7th to 28th September 1998. Unfed females An. sinensis were collected in cowshed and released after being marked with fluorescent dye at 23:00 hours on the same day. Released female mosquitoes were recaptured everyday during 21 days using light traps, which were set at 10 sites in the cowsheds located 1, 3, 6, 9 and 12 km north-northwest and north-northeast and at 3 sites located 1, 6 and 9 km toward south-west from the release point. In addition, to study the longest flight distance in one night, we set the light traps at 16 and 20 km toward north-northeast from the release site. All the collected mosquitoes were placed on filter papers and observed on UV transilluminator after treatment with one drop of 100% ethanol. Out of 12,773 females of An. sinensis released, 194 marked females mosquitoes were recaptured, giving 1.52% recapture rate. Of 194, 72 mosquitoes (37 1%) were recaptured in light traps from three places set at 1 km from the release point, 57 mosquitoes (29.4%) from two places at 1-3 km, 41 mosquitoes (21.1%) from three places at 3-6 km, 20 mosquitoes (10.3%) from three places at 6-9 km, and 4 mosquitoes (2.1%) from two places at 9-12 km. Since 170 female mosquitoes (87.6%) out of 194 marked mosquitoes were captured within 6 km from the release point, this flight radius represents the main activity area. An. sinensis was found to be able to fly at least 12 km during one night.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2010.05a
• /
• pp.6-6
• /
• 2010

Bacteria of the Bacillus sp. are well known to possess antagonistic activity against numerous plant pathogens. In the present study, 11 Bacillus sp. were isolated from the brackish environment and assayed for antagonistic activity under in vitro and in vivo conditions. Among the 11 isolates tested, 9 isolates effectively inhibited the growth of various plant pathogens, namely Phytophthora capsici, Phytophthora citropthora, Phytophthora citricola, Phytophthora sojae, Colletotricum coccodes, Colletotricum gloeosporioides, Colletotricum acutatum, Rhizoctonia solani, Fusarium solani, Fusarium graminearum, Pyricularia sp. and Monilina sp. The effective isolates were further screened for Phytophthora blight suppression in Capsicum annuum L. under green house conditions. The isolate SB10 exhibited the maximum (72.2%) reduction in disease severity. The antifungal compounds from the isolate were isolated and characterized. The isolated compounds exhibited high thermo stability ($100^{\circ}C$ for 30 min). Matrix-Assisted Laser Desorption Ionization-Time of Flight investigation of the antifungal compounds revealed three lipopeptide complexes, the surfactins, the iturins, and the fengycins.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_4
• /
• pp.1545-1553
• /
• 2018

Recent eruptive activity at Kīlauea Volcano started on at the end of April in 2018 showed rapid ground deflation between May and June in 2018. On summit area Halema'uma'u lava lake continued to drop at high speed and Kīlauea's summit continued to deflate. GPS receivers and electronic tiltmeters detected the surface deformation greater than 2 meters. We explored the time-series surface deformation at Kīlauea Volcano, focusing on the early stage of eruptive activity, using multi-temporal COSMO-SkyMed SAR imagery. The observed maximum deformation in line-of-sight (LOS) direction was about -1.5 meter, and it indicates approximately -1.9 meter in subsiding direction by applying incidence angle. The results showed that summit began to deflate just after the event started and most of deformation occurred between early May and the end of June. Moreover, we confirmed that summit's deflation rarely happened since July 2018, which means volcanic activity entered a stable stage. The best-fit magma source model based on time-series surface deformation demonstrated that magma chambers were lying at depths between 2-3 km, and it showed a deepening trend in time. Along with the change of source depth, the center of each magma model moved toward the southwest according to the time. These results have a potential risk of including bias coming from single track observation. Therefore, to complement the initial results, we need to generate precise magma source model based on three-dimensional measurements in further research.

• Biomedical Science Letters
• /
• v.12 no.4
• /
• pp.419-425
• /
• 2006

Phospholipase $C-{\gamma}1\;(PLC-{\gamma}1)$ is an important signaling molecule for cell proliferation and differentiation. $PLC-{\gamma}1$ contains two pleckstrin homology (PH) domains, which are responsible for protein-protein interaction and protein-lipid interaction. $PLC-{\gamma}1$ also has two Src homology (SH)2 domains and a SH3 domain, which are responsible for protein- protein interaction. To identity proteins that specifically binds to PH domain of $PLC-{\gamma}1$, we prepared and incubated the glutathione S-transferase(GST)-fused PH domains of $PLC-{\gamma}1$ with COS7 cell lysate. We found that 90 kDa protein specifically binds to PH domain of $PLC-{\gamma}1$. By matrix-assisted laser desorption ionization time of flight-mass spectrometry, the 90 kDa protein revealed to be heat shock protein (Hsp) $90{\beta}$. Hsp $90{\beta}$ is a molecular chaperone that stabilizes and facilitates the folding of proteins that are involved in cell signaling, including receptors for steroids hormones and a variety of protein kinases. To know whether Hsp $90{\beta}$ affects on $PLC-{\gamma}1$ activity, we performed $PIP_2$ hydrolyzing activity of $PLC-{\gamma}1$ in the presence of purified Hsp $90{\beta}$ in vitro. Our results show that the Hsp $90{\beta}$ dose-dependently inhibits the enzymatic activity of $PLC-{\gamma}1$ and further suggest that Hsp $90{\beta}$ regulates cell growth and differentiation via regulation of $PLC-{\gamma}1$ activity.

• The Plant Pathology Journal
• /
• v.37 no.1
• /
• pp.24-35
• /
• 2021

Blue mold caused by Penicillium expansum is one of the most significant postharvest diseases of apples. Some microorganisms associated with the surface of ripening apples possess the ability to inhibit the growth of P. expansum. However, the existing literature about their colonization in the stages before ripening is not explored in depth. This study aims to characterize the antagonistic capacity of bacterial populations from five fruit development stages of 'Royal Gala' apples. The results have shown that the density of the bacterial populations decreases throughout the ripening stages of fruit (from 1.0 × 105 to 1.1 × 101 cfu/㎠). A total of 25 bacterial morphotypes (corresponding to five genera identified by 16S RNA) were differentiated in which Bacillus stood out as a predominant genus. In the in vitro antagonism tests, 10 Bacillus strains (40%) inhibited the mycelial growth of P. expansum from 30.1% to 60.1%, while in fruit bioassays, the same strains reduced the fruit rot ranging from 12% to 66%. Moreover, the bacterial strains with antagonistic activity increased in the ripening fruit stage. B. subtilis subsp. spiziennii M24 obtained the highest antagonistic activity (66.9% of rot reduction). The matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis revealed that bacteria with antagonistic activity produce anti-fungal lipopeptides from iturin and fengycin families.

• Microbiology and Biotechnology Letters
• /
• v.46 no.1
• /
• pp.45-50
• /
• 2018

The chitosanase gene (btbchito) of Bacillus thuringiensis BMB171 was cloned and heterologously expressed in the yeast Pichia pastoris. After purification, about 300 mg of recombinant chitosanase was obtained from the 1-1 culture medium with a specific activity of 240 units/mg. Results determined by the combined use of thin layer chromatography (TLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) showed that the chitooligosaccharides (COSs) obtained by chitosan (N-deacetylated by 70%, 80%, and 90%) hydrolysis by rBTBCHITO were comprised of oligomers, with degrees of polymerization (DP) mainly ranging from trimers to heptamers; high molecular weight chitopentaose, chitohexaose, and chitoheptaose were also produced. Hydrolysis products was also deduced using MS since the COSs (n) are complex oligosaccharides with various acetyl groups from one to two, so the non-acetyl COSs (GlcN)n and COSs with more acetyls (> 2) were not detected. The employment of this method in the production of high molecular weight COSs may be useful for various industrial and biological applications, and the activity of chitosanase has great significance in research and other applications.

• Journal of The Korean Astronomical Society
• /
• v.53 no.6
• /
• pp.139-147
• /
• 2020

The sunspot area is a critical physical quantity for assessing the solar activity level; forecasts of the sunspot area are of great importance for studies of the solar activity and space weather. We developed an innovative hybrid model prediction method by integrating the complementary ensemble empirical mode decomposition (CEEMD) and extreme learning machine (ELM). The time series is first decomposed into intrinsic mode functions (IMFs) with different frequencies by CEEMD; these IMFs can be divided into three groups, a high-frequency group, a low-frequency group, and a trend group. The ELM forecasting models are established to forecast the three groups separately. The final forecast results are obtained by summing up the forecast values of each group. The proposed hybrid model is applied to the smoothed monthly mean sunspot area archived at NASA's Marshall Space Flight Center (MSFC). We find a mean absolute percentage error (MAPE) and a root mean square error (RMSE) of 1.80% and 9.75, respectively, which indicates that: (1) for the CEEMD-ELM model, the predicted sunspot area is in good agreement with the observed one; (2) the proposed model outperforms previous approaches in terms of prediction accuracy and operational efficiency.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.184-194
• /
• 2023

Recently, interest in food-derived bioactive peptides as promising ingredients for the prevention and improvement of hypertension is increasing. The purpose of this study was to determine the structure and antihypertensive effect of an antioxidant peptide purified from velvet antler in a previous study and evaluate its potential as a various bioactive peptide. Molecular weight (MW) and amino acid sequences of the purified peptide were determined by quadrupole time-of-flight electrospray ionization mass spectroscopy. The angiotensin I-converting enzyme (ACE) inhibition activity of the purified peptide was assessed by enzyme reaction methods and in silico molecular docking analysis to determine the interaction between the purified peptide and ACE. Also, antihypertensive effect of the purified peptide in spontaneously hypertensive rats (SHRs) was investigated. The purified antioxidant peptide was identified to be a pentapeptide Asp-Asn-Arg-Tyr-Tyr with a MW of 730.31 Da. This pentapeptide showed potent inhibition activity against ACE (IC₅₀ value, 3.72 μM). Molecular docking studies revealed a good and stable binding affinity between purified peptide and ACE and indicated that the purified peptide could interact with HOH2570, ARG522, ARG124, GLU143, HIS387, TRP357, and GLU403 residues of ACE. Furthermore, oral administration of the pentapeptide significantly reduced blood pressure in SHRs. The pentapeptide derived from enzymatic hydrolysate of velvet antler is an excellent ACE inhibitor. It might be effectively applied as an animal-based functional food ingredient.

• Journal of Microbiology
• /
• v.45 no.5
• /
• pp.402-408
• /
• 2007

A strain producing a potent protease was isolated from turban shell. The strain was identified as Bacillus sp. S17110 based on phylogenetic analysis. The enzyme was purified from culture supernatant of Bacillus sp. S17110 to homogeneity by ammonium sulfate precipitation, SP-Sepharose, and DEAE-Sepharose anion exchange chromatography. Protease activity of the purified protein against casein was found to be stable at pH 7 to pH 10 and around $50^{\circ}C$. Approximately 70% of proteolytic activity of the enzyme was detected either in the presence of 100 mM SDS or Tween 20. The enzyme activity was enhanced in the presence of $Ca^{2+},\;Zn^{2+},\;Mg^{2+}$, but was inhibited by EDTA, indicating that it requires metal for its activity. The purified enzyme was found to be a monomeric protein with a molecular mass of 75 kDa, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography. The purified enzyme was analyzed through peptide fingerprint mass spectra generated from matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and a BLAST search, and identified as immune inhibitor A (inhA) deduced from nucleotide sequence of B. cereus G9241. Since InhA was identified as protease that cleave antibacterial proteins found in insect, inhA-like protease purified from Bacillus sp. S17110 might be pathogenic to sea invertebrates.

• The Korean Journal of Air & Space Law and Policy
• /
• v.26 no.1
• /
• pp.271-297
• /
• 2011

Recently, risk of space accident possibility increased in according to commercial space activity and space debris. It failed launch satellite second times in South Korea. Therefore was discussed on liability and insurance issue. Generally, discuss of space insurance be divided two type. Firstly, space insurance relevant to launching satellite and in-orbit. Satellite Launch Insurance and In-Orbit Insurance by the Satellite Operator Secondly, space insurance relevant to Third Party Liability. The former is to protect owner of satellite and operator. The latter is to liable and indemnify owner of satellite and operator's liability. US, UK, France, Russia, South Korea forced to buy space insurance following to domestic law. This is a brief overview of risk allocation and insurance practices in the commercial space transportation industry today. We begin with traditional space transportation, i.e., commercial satellite launches. This is a mature industry with known players. Industry practices have developed and legislation has been adopted in the U.S. and other countries over the past decades to address liability and insurance issues. The primary focus here is on U.S. law, but the discussion of industry practice applies more generally. We then move on to a more exotic form of space transportation: Commercial human space flight. Several private companies are now signing up space tourists for commercial suborbital human space flight, advertised to become available in the near future. The United States amended its launch legislation in 2004 to promote commercial human space flight. But questions remain as to how this new industry will respond to the risk allocation regime established by the U.S. legislation, which leaves both the space flight operator and space tourist exposed to risk and potential liability. As a general proposition, state statutes and contractual waivers alone cannot be relied upon to provide adequate liability protection, and insurance will be required. Federally mandated contractual waivers by space flight participants or liability caps would be helpful to complement insurance solutions. Eventually, as the industry matures, such practices could be extended to an international legal regime. For all the issues mentioned above, I have studied the existing international treaties and several country's domestic law to the space by referring U.S's Commercial Space Launch Amendment Act of 2004 and concluded that uniform legal regime to govern these insurance issues should be established domestically and internationally in the future.