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        검색결과 25

        1.
        2023.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the astronomical phenomenon records of Sukjong’s 𝐶ℎ𝑢𝑛𝑏𝑎𝑛𝑔-𝐼𝑙𝑔𝑖 made by 𝑆𝑖𝑔𝑎𝑛𝑔𝑤𝑜𝑛 (Royal Educational Office of the Crown Prince) at which King Sukjong was the crown prince (i.e., 1667 January 24–1674 September 22). From the daily records of 2,799 days, we extract the astronomical records of 1,443 days and classify them into 14 categories. Then, we group the records of each category into five phenomena (Atmosphere, Eclipse, Daylight Appearance, Apparition, and Appulse) and compare them with the results of modern astronomical computations wherever possible. Except for Atmosphere group comprising records of meteorological events, such as solar halo, lunar halo, and unusual clouds, the significant findings in every other group are as follows: In Eclipse group, the solar eclipse that occurred on 1673 August 12 was unobservable in Korea, which is in contrast to the record of 𝐽𝑜𝑠𝑒𝑜𝑛𝑤𝑎𝑛𝑔 𝑗𝑜-𝑆𝑖𝑙𝑙𝑜𝑘 (Annals of the Joseon Dynasty), which states that the sun was in eclipse around sunset time, as observed at 𝑁𝑎𝑚 mountain. From the lunar eclipse records, we verify that the Joseon court did not change the date of the events observed after midnight. In Daylight Appearance group, we confirm that this phenomenon was observed during the daytime and not during twilight. We further suggest that if observation conditions are met, a celestial body brighter than −2.3 mag could be seen during the daytime with the naked-eye. In Apparition group, we find the possibilities that the Orionid meteor shower had influence on the meteor records and the seasonality on the aurora records. We also find that the Korean records in which the coma of comet C/1668 E1 was located below the horizon were overlooked in previous studies. Finally, we find that the records of Appulse group generally agree with the results of modern calculations. The records of 𝐵𝑒𝑜𝑚 (trespass in literal) and 𝑆𝑖𝑘 (eating in literal) events show average angular separations of 1.2◦ and 1.0◦, respectively. In conclusion, we believe this work helps study the astronomical records of other logs of 𝑆𝑖𝑔𝑎𝑛𝑔𝑤𝑜𝑛, such as Sunjong’s 𝐶ℎ𝑢𝑛𝑏𝑎𝑛𝑔-𝐼𝑙𝑔𝑖.
        4,800원
        2.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fescues, which are widely cultivated as grasses and forages around the world, are often naturally infected with the endophyte, Epichloë. This fungus, transmitted through seeds, imparts resistance to drying and herbivorous insects in its host without causing any external damage, thereby contributing to the adaptation of the host to the environment and maintaining a symbiosis. However, some endophytes, such as E. coenophialum synthesize ergovaline or lolitrem B, which accumulate in the plant and impart anti-mammalian properties. For example, when livestock consume excessive amounts of grass containing toxic endophytes, problems associated with neuromuscular abnormalities, such as convulsions, paralysis, high fever, decreased milk production, reproductive disorders, and even death, can occur. Therefore, pre-inoculation with non-toxic endogenous fungi or management with endophyte-free grass is important in preventing damage to livestock and producing high-quality forage. To date, the diagnosis of endophytes has been mainly performed by observation under a microscope following staining, or by performing an immune blot assay using a monoclonal antibody. Recently, the polymerase chain reaction (PCR)-based molecular diagnostic method is gaining importance in the fields of agriculture, livestock, and healthcare given the method’s advantages. These include faster results, with greater accuracy and sensitivity than those obtained using conventional diagnostic methods. For the diagnosis of endophytes, the nested PCR method is the only available option developed; however, it is limited by the fact that the level of toxic alkaloid synthesis cannot be estimated. Therefore, in this study, we aimed to develop a triplex real-time PCR diagnostic method that can determine the presence or absence of endophyte infection using DNA extracted from seeds within 1 h, while simultaneously detecting easD and LtmC genes, which are related to toxic alkaloid synthesis. This new method was then also applied to real field samples.
        4,000원
        3.
        2018.09 구독 인증기관·개인회원 무료
        Glutathione S-transferase (GST) is a key gene involved in multiple stress tolerance in all living organisms, though it is still to be disclosed the gene function in teff grass [Eragrostis tef (Zucc.)Trotter].The objectives of this study were to clone and molecular characterization of GST gene in teff grass. We characterized GST1 from teff grass (EtGST1), it composed of a 645-bp open reading frame (ORF) that encoded 195 amino acid residue. Further, we transformed EtGST1 in E.coli BL21 (DE3) cells. This recombinant EtGST1 in E.coli BL21(DE3) induced at 37°C temperature. In addition, Growth of cells overexpressing EtGST1 rapidly increased in the presence of polyethylene glycol (5%), heat (46°C), NaCl (0.6%), and arsenic (1 mM) than that of cells harboring an empty vector. These results suggest that EtGST1 would be suitable candidate for improving tolerance in forages and/or grasses species against multiple abiotic stresses.
        4.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We analyze the time data recorded in Korean astronomical almanacs for the years from 1913 to 1945, which belong to the period in which Japan occupied Korea (1910--1945). These almanacs, published by Japanese scholars, differ from previous almanacs in terms of organization, content, and calendrical methods. In this study, we first extract twelve kinds of time data from the almanacs at the following times: solar terms, rising and setting of the Sun and Moon, transit of the Sun, phases of the Moon (i.e., new Moon, first quarter Moon, full Moon, and last quarter Moon), and eclipses of the Sun and Moon. Then, we compare the time data with that obtained from modern calculations. Even though all time data in the almanacs are tabulated in units of minutes, we calculate the data in units of seconds and determine the root mean square (RMS) deviation values for each kind of time data to estimate the accuracy of the data. Our findings are as follows: First, the kind and tabulation method of time data changes several times. For instance, solar transit time is listed only for six years from 1937 to 1942. Second, the times of two equinoxes and those of a new Moon are considerably close to midnight. Third, there are some typographical errors in the almanacs, particularly in the times of moonrise and moonset. Fourth, the contact times for lunar eclipses represent the times of the umbra and not of the penumbra, which is different from the times for solar eclipses. Finally, the RMS deviation values are approximately 0.5 min on average in all kinds of time data, even though they show slightly large differences in the times related to the Moon. In conclusion, we believe that this study is useful for investigating the time data in the almanacs of other East Asian countries that were published during the same period, such as China, Japan, and Manchuria.
        4,000원
        5.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) is an upstream signaling molecule that has been shown to induce stress tolerance in plants. In this study, the AtNDPK2 gene, under the control of a stress-inducible SWPA2 promoter, was introduced into the genome of tall fescue (Festuca arundinacea Schreb.) plants. The induction of the transgene expression mediated by methyl viologen (MV) and NaCl treatments were confirmed by RT-PCR and northern blot analysis, respectively. Under salt stress treatment, the transgenic tall fescue plants (SN) exhibited lower level of H2O2 and lipid peroxidation accumulations than the non-transgenic (NT) plants. The transgenic tall fescue plants also showed higher level of NDPK enzyme activity compared to NT plants. The SN plants were survived at 300 mM NaCl treatment, whereas the NT plants were severely affected. These results indicate that stress-inducible overexpression of AtNDPK2 might efficiently confer the salt stress tolerance in tall fescue plants.
        4,000원
        7.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present research investigated copper and cadmium stress-induced differentially expressed genes (DEGs) using annealing control primers (ACP) with the differential display reverse transcription polymerase chain reaction technique in alfalfa (Medicago sativa L. cv. Vernal) leaves. Alfalfa leaves were subjected to 250 μM of copper and cadmium treatment for a period of 6 h. A total of 120 ACPs was used. During copper and cadmium treatment, 6 DEGs were found to be up or down regulated. During copper stress treatment, 1 DEG was up-regulated, and 3 novel genes were discovered. Similarly, during cadmium stress treatment, 1 DEG was up-regulated and 5 novel genes were identified. Among all 6 DEGs, DEG-4 was identified as the gene for trans-2,3-enoyl-CoA reductase, DEG-5 was identified as the gene for senescence-associated protein DIN1 and DEG-6 was identified for caffeic acid O-methyltransferase. All the up-regulated genes may play a role in copper and cadmium stress tolerance in alfalfa.
        4,000원
        8.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the growth performance and field evaluation of the dual herbicide-resistant transgenic creeping bentgrass plants. The effect of glyphosate treatment on the herbicide resistance of the transgenic creeping bentgrass plants was determined, and the non-transgenic control plant withered at the concentration 11 μg/mL or higher whereas the transgenic creeping bentgrass plants survived the treatment at the concentration of 3,000 μg/mL, and the increase of the plant length was repressed as the glyphosate treatment concentration was increased. At field evaluation, glufosinate-ammonium and glyphosate were simultaneously treated to investigate the weed control effect. The results showed that more than 90% of the weeds withered four week after herbicide treatment, while the transgenic creeping bentgrass plants continued to grow normally. Therefore, the dual herbicideresistant creeping bentgrass plants may be able to greatly contribute to the efficiency of weed control and to the economic feasibility of mowing in places such as golf courses.
        3,000원
        9.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.
        4,000원
        10.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        티모시의 4가지 품종을 이용하여 성숙종자로 부터 캘러스 유도 및 식물체 재분화 효율을 조사하였다. 4주 동안 배양한 종자로부터 캘러스 유도율은 Colt, Chair, Richmond, Hokuo 순으로 캘러스 유도율을 보였고, 식물체로의 재분화 또한 캘러스 유도율과 같은 Colt > Chair > Richmond > Hokuo 순으로 나타났다. 기본 배지의 종류에 따른 배양 효율의 차이는 품종별 차이는 있으나 MS 배지가, 식물체 재분화는 N6 배지와
        4,000원
        12.
        2009.08 구독 인증기관·개인회원 무료
        Antibiotics marker-free with herbicide-resistant tall fescue plants were produced through Agrobacterium: mediated transformation system. Embryogenic calli derived calli were infected with Agrobacterium tumefaciens strain EHA105 harboring the pCAMBIA3300 vector containing the bar and the CP4-EPSPS genes. The PPT-resistant calli and plants were selected with 10 ㎎/L PPT, respectively. Soil-grown plants were obtained about 14-16 weeks after Agrobacterium-mediated transformation. Genetic transformation of the regenerated plants growing under selection was demonstrated by PCR, and Southern blot analysis revealed that one copies of the transgene were integrated into the plant genome of each transgenic plant. Expression of the bar and CP4-EPSPS genes in transgenic plants was confirmed by Northern blot analysis and CP4-EPSPS genes in transgenic plant ELISA uses antibody protein by ELISA Assays. Transgenic plants sprayed of two herbicides with glufosinate ammonium or glyphosate remained green and healthy. We therefore report here a successful and reliable Agrobacterium-mediated transformation of two herbicide-resistances and this method may be useful for routine transformation and has the potential to develop new varieties of tall fescue with several important genes.
        13.
        2009.08 구독 인증기관·개인회원 무료
        In the present study, we have developed a high-frequency plant regeneration system for Italian ryegrass via callus culture using mature seeds as explants. Optimal embryogenic callus induction was found to occur in MS medium containing 5 ㎎ 1?¹ 2,4-D, 0.5 ㎎ 1?¹ BA, 500 ㎎ 1?¹ L-proline, 1 g 1?¹ casein hydrolysate, 30 g 1?¹ sucrose, 7 ㎎ 1?¹ AgNO₃, 2 ㎎ 1?¹ CuSO₄ and solidified with 3 g 1?¹ Gelrite. The highest regeneration rate was obtained in MS medium containing 1 ㎎ 1?¹ 2,4-D, 5 ㎎ 1?¹ BA, 500 ㎎ 1?¹ L-proline, 1 g 1?¹ casein hydrolysate, 1 ㎎ 1?¹ thiamine-HCl, 30 g 1?¹ sucrose, 7 ㎎ 1?¹ AgNO₃, 2 ㎎ 1?¹ CuSO₄ and solidified with 3 g 1?¹ Gelrite. By using the most effective treatment determined for each parameter, the highest rates of embryogenic callus formation (48.9%) and regeneration (47.6%) were obtained with the Hwasan 101 cultivar. The overall plant regeneration rates of the examined cultivars ranged from 7.5% to 23.2%. Thus, optimization of regeneration frequency using mature seeds as explant material may offer a simple and efficient protocol for Italian ryegrass that may improve molecular breeding of this species.
        14.
        2009.08 구독 인증기관·개인회원 무료
        In the present study, genotypic variation of Agrobacterium-mediated transformation of Korean Italian ryegrass has been evaluated. Mature seed-derived calli of a total of seven cultivars were infected and co-cultured with Agrobacterium tumefaciens carrying the binary vector pCAMBIA1301, which contains a reporter gene (gus) and a plant selectable marker gene conferring resistance to hygromycin (hpt) in the T-DNA region. The effects of several factors such as callus type and callus age on transformation frequency and the expression of the GUS gene were investigated. The highest transformation frequency (6.7%) was obtained with the Hwasan 101 cultivar when 9-week-old calli (type-I) were inoculated with Agrobacterium. The overall transformation rates of the examined cultivars ranged from 0.4% to 6.7%. GUS histochemical assays, PCR, and southern analysis of transgenic plants demonstrated that transgenes were successfully integrated into the genome of Italian ryegrass. Thus, optimization of transformation frequency and selection of a suitable cultivar of Italian ryegrass may improve molecular breeding of this species.
        19.
        2019.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        We investigate solar and lunar motions in the Seonmyeong (SM) calendar that was compiled by Xu, Ang of the Tang dynasty (A.D. 618–907) in China and used for 71 years from 822 to 892. This calendar was also used in Korea during the Goryeo dynasty (A.D. 918–1392) and in Japan for 823 years from 862 to 1684, the longest time among the three countries. Referring to historical documents of China, Korea, and Japan, we analyze the calendrical methods of calculating the daily apparent movements of the Sun and Moon in the SM calendar, which were considered their unequal motions, and compare the movements with the results of modern calculations for three periods in the Goryeo dynasty: 919, 1155, and 1392 years (i.e., the beginning, middle, and ending of the dynasty, respectively). We find that a quadratic equation was employed to obtain the daily movement of the Sun using physical quantities on the instant of each solar term, which was tabulated in its calendar book such as the Goryeosa (History of the Goryeo Dynasty). For quantitative analysis, we compute the mean absolute difference (MAD) of the daily apparent movement between the SM calendar and modern calculations and obtain 0.33, 0.30, and 0.31 arcmin for the periods of 919, 1155, and 1392 years, respectively. Meanwhile, we find relatively large MAD values in the daily movement of the Moon: 0.217, 0.284, and 0.240 degrees for each corresponding year. An interesting point is that the MAD value in the lunar motion shows the maximum in 1155 years, and is the minimum in the solar motion. In conclusion, we believe that this study will facilitate in the understanding of the SM calendar further, particularly in the calendrical methods of calculating sunrise, sunset, and eclipse times.
        20.
        2017.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this paper, we investigate the observations of Venus in daytime that are recorded in the Goryeosa (History of the Goryeo Dynasty, A.D. 918-1392). There are a total of 167 accounts of such observations in this historical book, spanning a period of 378 yr (from 1014 to 1392). These include six accounts where the days of the observation are not specified and two accounts where the phase angles are outside the calculation range of the equation used in our study. We analyze the number distribution of 164 accounts in 16 yr intervals covering the period from 1023 to 1391. We find that this distribution shows its minimum at around 1232, when the Goryeo dynasty moved the capital to the Ganghwa Island because of the Mongol invasion, and its maximum at around 1390, about the time when the dynasty fell. In addition, we calculate the azimuth, altitude, solar elongation, and apparent magnitude of Venus at sunset for 159 observations, excluding the eight accounts mentioned above, using the DE 406 ephemeris and modern astronomical algorithms. We find that the average elongation and magnitude of Venus on the days of those accounts were ~40° and -4.5, respectively, whereas the minimum magnitude was -3.8. The results of this study are useful for estimating the practical conditions for observing Venus in daylight with the naked eye and they also provide additional insight into the corresponding historical accounts contained in the Goryeosa.
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