• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.131-139
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• 2016

Detailed knowledge on maskelynite, a glassy phase of plagioclase found in shocked meteorites and impact craters, is essential to understand a shock metamorphism. Here, we explore an inhomogeneous shock metamorphism in the lunar meteorite Mount DeWitt (DEW) 12007 with an aim to understand the formation mechanism of maskelynite. Most plagioclase grains in the DEW 12007 partially amorphized into maskelynite with a unidirectional orientation. Back-scattered electron (BSE) images of maskelynite show a remnant of planar deformation fracture possibly indicating that the maskelynite would be formed by solid-state transformation(i.e., diaplectic glass). Plagioclase with flow texture is also observed along the rim of maskelynite, which would be a result of recrystallization of melted plagioclase. Results of Raman experiments suggest that shock pressure for plagioclase and maskelynite in the DEW 12007 is approximately 5-32 GPa and 26-45 GPa, respectively. The difference in shock pressures between plagioclase and maskelynite can be originated from 1) external factors such as inhomogeneous shock pressure and/or 2) internal factors such as chemical composition and porosity of rock. Unfortunately, Raman spectroscopy has a limitation in revealing the detailed atomic structure of maskelynite such as development of six- or five-coordinated aluminum atom upon various shock pressure. Further studies using nuclear magnetic resonance spectroscopy are necessary to understand the formation mechanism of maskelynite under high pressure.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.73-82
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• 2004

New photometric and spectroscopic solutions of W-type overcontact binary V 417 Aql were obtained by solving the UBV light curves of Samec et al. (1997) and radial-velocity ones of Lu ＆ Rucinski (1999) with the 2003 version of the Wilson-Devinney binary code. In the light curve synthesis the light of a third-body, which Qian (2003) proposed, was considered and obtained about 2.7%, 2.2%, and 0.4% for U, B, and V bandpasses, respectively. The model with third-light is better fitted to eclipse parts than that with no third-light. Absolute dimensions of V417 Aql are determined from our solution as $M_1$= 0.53 $M_{*}$, $M_2$= 1.45 $M_{*}$, $R_1$= 0.84 $R_{*}$, and $R_2$= 1.31 $M_{*}$, and the distance to it is deduced as about 216pc. Our distance is well consistent with that (204pc) derived from Rucinski ＆ Duerbeck's (1997) relation, $M_{v}$ = $M_{v}$(log P, B-V), but is more distant than that (131$\pm$40pc) determined by the Hipparcos trigonometric parallax. The difference may result from the relatively large error of Hipparcos parallax for V 417 Aql.l.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.41-46
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• 1989

This study was performed to observe the infection rate and infection intensity of fresh water fish such as pale chub (Z. platypus) and dark chub (Z. temminckii) with the metacercariae of C. armatus. The fish were caught in several rivers and streams from June to September, 1988 and examined by artificial digestion technique. Total 370 fish were caught at 19 rivers. The metacercarial (C. armatus) infection rate and average burden in Z. Platypus were 86.8% and 224, and those in Z. tsmminckii were 78.5% and 131. The infection rate and burden per fish were 73.4% and 32 in the fish caught from the Han river, and 88.0% and 44 from the Youngsan river. All fish caught from the Keum and the Tamjin river were infected and their mean metacercarial density was 45 and 59 respectively. The infection rate and density in fish caught from the Seomjin and Nagdong rivers were 100% and 119, and 81.0% and 348 respectively. From this study, it is confirmed that C. armatus is widely distributed along 5 major rivers in Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.3
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• pp.131-141
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• 2013

Stock identification of Todarodes pacificus collected in the East Sea, Yellow Sea and East China Sea during the period from September to December in 2011 was analyzed by morphometric characters and mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) gene nucleotide variations. Frequency distributions of mantle length was analyzed by morphological method with measuring size of T. pacificus. Then each stock was estimated to confirm their maturation for mean mantle length comparing with mean mature mantle length 20-22 cm. According to morphologic stock identification, it is estimated that the northern part of East Sea is categorized as summer stock and the rest parts, including mid /southern part of the East Sea, northern part of the East China Sea and northern part of the West Sea were autumn stock. For genetic analysis, a total 49 haplotypes were defined by 33 variable nucleotide sites. From the extensive haplotype diversity, limited nucleotide diversity and star-like shape of haplotype network, T. pacificus appears to have undergone rapid population expansion from an ancestral population with a small effective population size. Although pair-wise Fst estimates which represent genetic difference among groups were low, there are relatively remarkable difference of Fst between middle and southern part of the East Sea. Although middle part of the East Sea and southern part of the East Sea were situated at the East Sea, genetically separated groups were appeared.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.131-135
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• 2018

Plants produce extrafloral nectar (EFN), liquid of carbohydrates to protect themselves against various insect herbivores through attracting natural enemy, ants, wasp and parasitoids, so EFN production is well known as one of indirect defense mechanisms. In many plants, EFN production is increased or induced when plants are attacked and damaged by insect feeding, whereas there are some plants whose EFN production is not altered or even decreased upon insect attack. The feeding types (chewing or sap feeding) of insects attacking plants also affect EFN production. The objective of this study was to examine how insect herbivore alters production of extrafloral nectar of Impatiens balsamina. Two different types of herbivores, leaf chewing and sap feeding insects, Spodoptera litura and Impatientinum impatiens respectively, are utilized. Plants were mechanically damaged by making holes on leaves with Jasmonic acid (JA) and regurgitate of S. litura added on. Two different densities of aphids were confined on leaves. The results of the study was that mechanical damage and JA or regurgitate addition did not affect EFN production in I. balsamina. Aphid feeding, regardless of density treated, decreased EFN production. The results of the study suggest that production of extrafloral nectar of Impatiens balsamina can be changed by insect feeding, and the effects of insect feeding can depend on the type of insects.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.272-276
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• 2003

Sapgyo Lake is an artificial freshwater reservoir which is located to the midwest of Korea and is the main water reservoir for industry and agriculture of the region. In this study we investigated environmental factors and the change of bacterial community with the influence of surrounding inflow water and the seasonal variation using the molecular ecological approach. Water samples were collected at front of the dike in May and August, 2001. Bacterial genomic DNAs were extracted directly and purified for the amplification of bacterial 16S rDNA. Clone libraries of the 16S rDNA were constructed using pGEM-T easy vector and RFLP analysis was performed to make a group as OTUs with 4 base recognizing enzymes (MspI and HaeIII). The estimated values of richness in August sample was higher than in May. Thirty-three of 153 clones in May and thirty-eight of 131 clones in August were sequenced from forward region of bacterial 16S rDNA for about 600~800 bp. Proteobacteria, Cytophaga, gram positive bacteria and Verrucomicrobia were observed both months. Especially, Planctomyces, cyanobacteria and chloroplast appeared in August when algal bloom occurred. On the whole investigation, Sapgyo lake showed a typical community structure of estuarine and was influenced by heterochthonous organic matters from the surrounding stream.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.521-527
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• 1992

This study was conducted to obtain the fundamental information on the relationship between sugar content variation and other major characteristics in colored-soybean strains collected in Korea. Sugar content varied from 8.3% to 12.1%, and averaged to be 10.1% in collected colored-soybean strains. On the basis of maturity, soybean growth types were distributed 0.5%, 1%, 5.7%, 16%, 19%, 22%, 14%, and 19% in maturity group 0 (less then 115 days), group I(116 to 123 days), group II (124 to 131 days), group III (132 to 139 days), groupIV(140 to 147 days), group V (148 to 155 days), group Ⅵ(156 to 163 days), and group Ⅶ(over 164 days), respectively. Most of colored-soybean strains were in the middle and late maturity group(maturityIII group toⅦ). Sugar content was tended to be higher in soybean seeds of late than early maturity group. Difference in sugar content was not present according to the seed coat color, whereas strains with bloom seed was higher in sugar content than those with non-bloom seed. Higher seed sugar content was shown in green seed embryo than yellow one. Total sugar content was correlated negatively with protein content (-0.29$^{**}$), positively with oil content (0.21$^{**}$) and growth period(0.36$^{**}$) in all collected colored-soybean strains, and within respective maturity group except early maturity group strains, total sugar content was correlated significantly with protein, oil, ADV, and other characteristics.stics.

• Atmosphere
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• v.21 no.2
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• pp.131-142
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• 2011

Spectral solar irradiances were observed using a visible and UV Multi-Filter Rotating Shadowband Radiometer on the rooftop of the Science Building at Yonsei University, Seoul ($37.57^{\circ}N$, $126.98^{\circ}E$, 86 m) during one year period in 2006. 1-min measurements of global(total) and diffuse solar irradiances over the solar zenith angle (SZA) ranges from $20^{\circ}$ to $70^{\circ}$ were used to examine the effects of clouds and total optical depth (TOD) on enhancing four solar irradiance components (broadband 395-955 nm, UV channel 304.5 nm, visible channel 495.2 nm, and infrared channel 869.2 nm) together with the sky camera images for the assessment of cloud conditions at the time of each measurement. The obtained clear-sky irradiance measurements were used for empirical model of clear-sky irradiance with the cosine of the solar zenith angle (SZA) as an independent variable. These developed models produce continuous estimates of global and diffuse solar irradiances for clear sky. Then, the clear-sky irradiances are used to estimate the effects of clouds and TOD on the enhancement of surface solar irradiance as a difference between the measured and the estimated clear-sky values. It was found that the enhancements occur at TODs less than 1.0 (i.e. transmissivity greater than 37%) when solar disk was not obscured or obscured by optically thin clouds. Although the TOD is less than 1.0, the probability of the occurrence for the enhancements shows 50~65% depending on four different solar radiation components with the low UV irradiance. The cumulus types such as stratoculmus and altoculumus were found to produce localized enhancement of broadband global solar irradiance of up to 36.0% at TOD of 0.43 under overcast skies (cloud cover 90%) when direct solar beam was unobstructed through the broken clouds. However, those same type clouds were found to attenuate up to 80% of the incoming global solar irradiance at TOD of about 7.0. The maximum global UV enhancement was only 3.8% which is much lower than those of other three solar components because of the light scattering efficiency of cloud drops. It was shown that the most of the enhancements occurred under cloud cover from 40 to 90%. The broadband global enhancement greater than 20% occurred for SZAs ranging from 28 to $62^{\circ}$. The broadband diffuse irradiance has been increased up to 467.8% (TOD 0.34) by clouds. In the case of channel 869.0 nm, the maximum diffuse enhancement was 609.5%. Thus, it is required to measure irradiance for various cloud conditions in order to obtain climatological values, to trace the differences among cloud types, and to eventually estimate the influence on solar irradiance by cloud characteristics.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.131-139
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• 2015

This study investigated the quality properties of smoked breast meats produced by fresh and frozen-thawed duck meat. Each thirty breast meats from fresh and frozen-thawed duck carcass was used for this study. The yield of smoked breast meat was measured right after curing and smoking of raw duck breast meat. And, the number of total aerobic bacteria, color, texture, and sensory property of vacuum-packaged smoked breast meats were evaluated during storage at $4^{\circ}C$ for 28 days. No significant difference was found in yield between smoked breast meats produced by fresh and thawed duck meats (p>0.05). The number of total aerobic bacteria and color of smoked breast meat produced by thawed duck meat were not significantly different compared with those by fresh one throughout storage period (p>0.05). The all texture properties were not significantly different between smoked breast meats produced by fresh and thawed duck meats by 14 days of storage (p>0.05). However, on day 21 and 28, the hardness and gumminess of smoked breast meat produced by fresh duck meat were significantly higher than those by thawed one (p<0.05). In sensorial property, smoked breast meat produced by thawed duck meat received significantly high scores in color, juiciness, and tenderness on days 0, 14, and 28 and in flavor and overall acceptance on days 0 and 14 compared with those by fresh one (p<0.05). Therefore, we concluded that the use of thawed duck meat for producing smoked duck meat product may be not worse than the use of fresh duck meat in quality of smoked duck meat product. In addition, the use of thawed duck meat may be better in sensorial quality of smoked duck meat product than that of fresh one.

• Journal of Ginseng Research
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• v.29 no.3
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• pp.131-137
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• 2005

Acetaminophen(APAP) is one of the most extensively used analgesics and antipyreics worldwide. In order to investigate preventive effects of white and red ginseng extracts, male ICR mice pretreated with white or red ginseng extracts(50 or 250 mg/kg/day, for 5 days, orally) before treatment with acetaminophen(800mg/kg, i.p, single dose). In an attempt to elucidate the possible mechanism of hepatoprotective effect, superoxide dismutase(SOD), catalase(CAT), hydroperoxide, malondialdehyde(MDA) contents were studied. In pretreatment with red ginseng extract(250 mg/kg), the activities of SOD, CAT were generally highest and the hydrogen peroxide content was lowest. The levels of MDA were significantly lower in white and red ginseng extract groups than those in the APAP groups. By treatment with ginseng extract, high content of hydrogen peroxide and increased lipid peroxidatiion level caused by APAP could be lowered. Also, ginseng extracts were found to increase antioxidative enzyme activity. Finally, the results suggest that the antioxidant effects of (white and red) ginseng extracts prevent oxidative damage by direct antioxidant effects involving SOD, CAT and increasing the ability to synthesize endogenous antioxidants. It was concluded that ginseng can protect against APAP intoxication through its antioxidant properties.