• Korean Journal of Weed Science
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• v.8 no.1
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• pp.9-14
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• 1988

Three varieties of Echinochloa crus-galli (L.) Beauv. and five collections different in gross morphology from the E. crus-galli species were obtained in a lowland rice field located in Jukjeol-Ri, Soyang-Myeon, Wanju-Kun, Jeonbug to compare the ecological and physiological characteristics. There were great variations in seed dormancy, relative growth rates, days required to panicle emergence and panicle morphology among the collections. On the basis of the cluster analysis using the different characteristics, the collections were divided into three groups; E. crus-galli var. frumentaceae and its two ecotypcs, E. crus-galli var. echinata and its two ecotypes, and E crus-galli var. crus-galli and its one ecotype. There were differential responses in percent germination and post-germination growth of the collections to butachlor (2-chloro-2', 6'-diethyl-N-butoxymethyl acetanilide).

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.52-61
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• 2022

Purpose: Most cases of oral and maxillofacial infections are usually easily treated by proper diagnosis, elimination of causative factors, and antibiotic therapy. However, the emergence and the increase of multidrug-resistant bacteria make treatment challenging. "ESKAPE" pathogens are the most common opportunistic organisms in nosocomial infections and have resistant to commonly used antibiotics. There are many medical reviews of ESKAPE pathogens, but few in dentistry. This study focuses on oral and maxillofacial infection especially with ESKAPE pathogens. The purpose of this study is to prepare feasible data about tracing and treatment of infection related to pathogens that may be beneficial to clinicians. Methods: A total of 154 patients with oral and maxillofacial infections were reviewed by analyzing retrospectively hospitalized data in the Department of Oral and Maxillofacial surgery, Chosun University Hospital, Korea, past 5 years from January 2014 to December 2018. Based on the medical records and microbiological tests, the results were divided into two groups: infections with ESKAPE pathogens and other bacteria. Results: A total of 22 species were isolated from 154 patients. The proportion of ESKAPE pathogens among all bacterial isolates collected from infected patients was 39.6%. Causative factors, especially in post-operative infection, showed a statistically significant correlation to ESKAPE infections (29 cases). And average of treatment period in ESKAPE group was longer than non-ESKAPE groups. Overall, Klebsiella pneumoniae (60.7%) was the most frequently isolated ESKAPE pathogen. And high antibiotic resistance rates had been detected in the ESKAPE during the five-year period. Conclusions: Infections with ESKAPE pathogens are now a problem that can no longer be overlooked in Dentistry. Based on results of this study, ESKAPE pathogens were highly associated with post-operative or opportunistic infections. Clinicians should be careful about these antibiotic resistant pathogens and use appropriate antibiotics to patients while having dental treatments.

• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.83-90
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• 2024

The emergence of coronavirus disease 2019 (COVID-19) vaccines has been a remarkable advancement. However, the efficacy, immunogenicity, and safety of these vaccines in individuals with liver cirrhosis require careful evaluation due to their compromised immune status and potential interactions with underlying liver disease. The present study aimed to evaluate the safety and efficacy of COVID-19 vaccines in liver cirrhosis patients. In the present study, we searched international databases, including Google Scholar, PubMed, Scopus, Embase, and Web of Science. The search strategy was carried out by using keywords and MeSH (Medical Subject Headings) terms. STATA ver. 15.0 (Stata Corp., USA) was used to analyze the data statistically. The analysis was performed using the randomeffects model. We also used the chi-square test and I² index to calculate heterogeneity among studies. For evaluating publication bias, Begg's funnel plots and Egger's tests were used. A total of 4,831 liver cirrhosis patients with COVID-19 were examined from 11 studies. The rate of hospitalization in the patients with liver cirrhosis was 17.6% (95% confidence interval [CI], 9%-44%). The rate of fever in the patients with liver cirrhosis was 4.5% (95% CI, 0.9%-8.1%). The rate of positive neutralizing antibodies in the patients with liver cirrhosis was 82.5% (95% CI, 69.8%-95.1%). Also, the rates of seroconversion after the second vaccination in patients with liver cirrhosis and the control group were 96.6% (95% CI, 92.0%-99.0%), and 99.7% (95% CI, 99.0%-100.0%), respectively. COVID-19 vaccines have demonstrated promising efficacy, immunogenicity, and safety profiles in individuals with liver cirrhosis, providing crucial protection against COVID-19-related complications.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.282-292
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• 2015

Seeds of colored rice generally have high anthocyanin and flavonoid content but some cultivars have low seed germination rate. This defect poses unstable seedling establishment in nursery bed. The seed gravity variations of 10 colored rice varieties and its effect on germination, seed soaking duration and their optimum seeding rates for seedling raising in machine transplanting were investigated in the experiment. Based on seed gravity distribution of the 7 black- and 3 red-colored rice varieties at three levels of seed gravity (1.0<, 1.0~1.06, 1.06>), the black colored seeds such as Josaengheugchal and Sinmyungheugchal had high amount of specific gravity of below 1.0 ranging from 86~ 96%, while they had only 3~13% of seeds in specific gravity above 1.06. Sintoheugmi, Heugjinju, Heugnam, Heugkwang had various mass of seeds, showing 29~44% for specific gravity of below 1.0, 24~39% for 1.0~1.06 and 25~45% for above 1.06. On the other hand, the red colored rice such as Hongjinju, Jeogjinju and Geonkanghongmi had high percentage of specific gravity of above 1.06 with 84~86% while they had only 9~12% of specific gravity below 1.0 similar to Ilmibyeo of noncolored rice. The black colored seed generally showed low germination percentage, slow germination speed and long mean germination time, and low water absorption rate as compared with seed of the red colored rice which was similar to those of Ilmibyeo used as a control cultivar. The black colored seeds took 2~4 days longer seed soaking duration than the red colored rice before germination. This was related to high seed amount of specific gravity below 1.0 in black colored rices. The high amount of seed gravity above 1.06 in the colored rice seeds was positively correlated with percentage of germination, germination speed and mean germination time, ripened grain ratio and water absorption. Seed gravity distribution effect were less pronounced between back- and red- colored seeds in seedling emergence. The black colored rice has slightly lower normal seedling emergence rate than the red colored rice and Ilmibyeo in the seedbed soil due to high percentage of ungerminated seed. Normal seedling emergence rate of the black colored rice in the seedbed was 75.2~82.2% for 10-day old seedling and 85.3~ 90.9% for 30-day old seedling which was lower by 4.5~ 8.0% and 0~3.3%, respectively, than the red colored rice. Based on the normal seedling number per tray of Ilmibyeo for seeding rate of 10-day and 30-day old seedlings, the recommended seeding rate of black colored rice is 200~ 220g seeds for the 10-day old seedling and 110~130g for the 30-day old seedling in transplanting rice while the seeding rate of the red colored rice was 220g seeds for the 10-day old seedling and 130g for the 30-day old seedling.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.203-209
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• 2001

Development and reproduction of the sweetpotato whitefly, Bemisia tabaci(B biotype) were investigated under different temperatures and host plants. Developmental periods from egg to pre-adult of whiteflies measured under four constant temperatures: they were 86.2 days at $15^{\circ}C$ and 17.0 days at $30^{\circ}C$. Lower threshold temperature and total effective temperature for the development of egg and nymph, and for the complete development (egg to emergence) were $10.1,\;11.6,\;11.1^{\circ}C$ and 110.3, 204.7, 317.3 degree days, respectively. The hatching and emergence rates were 87.0% at $25^{\circ}C$ and 76.7% at $20^{\circ}C$, which were higher than the results of other temperatures. The adult longevity was 23.6 and 14.0 days at $20^{\circ}C$ and $30^{\circ}C$, respectively. The highest average fecundity per female was 103.3 at $25^{\circ}C$. But there were no significant differences among the temperatures. The highest intrinsic rate of natural increase($r_{m}$) was 0.196 at $30^{\circ}C$ and the highest net reproduction rate ($R_{o}$) was 97.33 at $25^{\circ}C$. Developmental periods from egg to pre-adult of whiteflies were 21.2 on the tomato, 28.1 on red pepper, 22.2 on eggplant and 25.5 days on poinsetia. The hatching was highest (90.3%) on red paper and emergence rate was highest (89.6%) on eggplant. The longest longevity of adult female was 26.5 days on eggplant, and the average fecundity per female was greater on tomato and eggplant than on other host plants. The intrinsic rate of natural increase($r_{m}$) was the highest on tomato as 0.165 and the net reproduction rate ($R_{o}$) was the highest on eggplant as 106.1. As a result, the optimum range of temperature for the growth of B. tabaci was between $25^{\circ}C$ and $30^{\circ}C$, and the optimum host plant were tomato and eggplant among the plants tested.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.13-23
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• 1987

This study was conducted to know the effects of temperature conditions on the growth and oviposition of the brown planthopper(BPH), Nilaparvata lugens $St{\aa}l$. Results obtained were to predict the timing of the BPH control by measuring population dynamics of the BPH in response to temperature fluctuations upon migration of the insects in paddy fields. Developmental and ovipositional rates under constant and alternating temperature conditions were observed in a plant growth cabinet. Hatchabilities of eggs of the BPH were the highest at $25^{\circ}C$ and were decreased below or above the optimum temperature. Egg periods were the shortest at $27.5^{\circ}C$ and prolonged with decreasing temperature, but retarded at higher temperature above $30^{\circ}C$. Adult emergence rates were the highest at $27.5^{\circ}C$ and reduced with decreasing temperature, and no adult emerged at $32.5^{\circ}C$ and $35^{\circ}C$. Developmental period of nymph was the shortest at both $27.5^{\circ}C$ and $30^{\circ}C$, but extended with decreasing temperature. Female longevity was increased with decreasing temperature and the male longevity was the shortest at $27.5^{\circ}C$. Preoviposition period was the shortest at $32.5^{\circ}C$, but prolonged with decreasing temperature. It was about 6.5 times longer at $17.5^{\circ}C$ than that at $32.5^{\circ}C$. Number of eggs oviposited per female was the greatest at $25^{\circ}C$, but decreased at the temperature below or above the optimum. Under the same total effective day-degrees, hatchabilty at the alternating temperature was about 10% higher than that at the constant temperature but egg period at the alternating temperature was nearly identical as that at the constant. Under the $22^{\circ}C$ condition, emergence rate was about 8% higher at the alternating temperature than that at the constant, however, at the $28^{\circ}C$, the rate was about 8% higher at the constant than that at the alternating. Nymphal period was about $4{\sim}6$ days longer at the alternating temperature than that at the constant. Under the same total effective day-degrees in adult stage, both longevity and oviposition period were longer at alternating temperature than those at the constant. Number of eggs oviposited per female was also higher at the alternating. Longevities of females reared under $28^{\circ}C$ of constant temperature was the longest no matter what temperatures they were exposed after the emergence. This result seems to be indicating that female longevity is greatly influenced by the temperature to which they were exposed durings immature stages. Preoviposition period was affected by the temperature exposed during the nympal and adult stage whereas the number of eggs oviposited was affected by the temperature during the adult stage only. Based on the results from this study, the developmental threshold temperatures seem to be $14.12^{\circ}C$ for eggs, $14.76^{\circ}C$ for nymphs, $9.62^{\circ}C$ for adults, and $15.95^{\circ}C$ for preoviposition period. Estimated values of the total effective temperature for completing each stage were 141.25 day-degrees for eggs, 167.83 day-degrees for nymphs, 349.64 day-degrees for adults, and 58.60 day-degrees for preoviposition.

• Korean Journal of Medicinal Crop Science
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• v.12 no.4
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• pp.328-341
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• 2004

Presowing seed treatments used to enhance the rates of germination and afterward seedling emergence have not occasionally shown the same rate in indoor and field. The treatments considering germination mechanism and factors affecting germination must be totally included in indoor experiments so that the results drawn can be reproduced in the field. Seed germination is controlled by Phytochrome-mediated action changed with composition rates of red and far-red lights. Sunlight can penetrate soil into $6{\sim}9\;mm$ depth, which in turn means that seeds having $2{\sim}3\;mm$ in their width may receive the light if soil was covered 3 times over them. The penetrating light, moreover, turns to more far-red light than red light reverse to the sunlight. For germination tests after the artificial presowing seed treatments, therefore, seeds of smaller than 2 mm (< 2 mm), $2{\sim}3\;mm$, and larger than 3 mm (> 3 mm) must be done with incandescent lamp (IL) having more far-red light, with IL or in darkness, and in darkness, respectively. The 96 papers published in 13 Korean scientific journals up to the end of 2003 were analysed on the basis of the above explanation. 91 species were used 147 times as experimental materials; 101 times for < 2 mm seeds, 24 times for $2{\sim}3\;mm$ seeds and 22 times for > 3 mm seeds. If they were analysed as the light sources used for germination tests, correct applications reached more and less than 60% in both $2{\sim}3\;mm$ and > 3 mm seeds but 23% in < 2 mm seeds, conclusionally meaning that when the experimental results in the scientific papers were applied into farming practices, care was taken of their application because most of medicinal plant seeds were very small.

• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.81-94
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• 1990

Illegal transactions such as blackmarketing and smuggling allegedly result from too restrictive trade policies. A recent U.S. Senate hearing on the blackmarketing of American goods imported into Korea for the purpose of supporting United States troops and their dependents stationed in Korea concluded with the allegation that Korea's highly restrictive trade practices are responsible for the emergence of the black market. It has also suggested that the removal of such restrictive trade policies would eliminate black market activities. This study addresses the relationship between trade policy and blackmarketing by investigating whether trade liberalization results in the reduction of illegal transactions, and whether the eradication of blackmarketing indeed improves social welfare. When both legally imported goods and illegally exchanged items command the same price, trade liberalization, meaning a decrease in tariff rates or an increase in import quotas, will increase the quantity of legal imports at the expense of illegally transacted goods on the black market. But the price of legally imported goods usually differs from that of illegally sold ones. In this case, a change in the relative prices of these two groups of goods due to a change in trade policy will give rise to income, as well as substitution, effects. Initially, a decrease in the import price due to a decrease in import tax rates or an increase in the allotted quota will reduce illegal transactions, since the decrease in the import price will induce the substitution of legal imports for illegally exchanged, but otherwise, identical goods. On the other hand, the demand for the illegally transacted goods will rise, because of the income effect of the reduced import price. Thus, assuming the positive income effect overwhelms the negative substitution effect, the demand for illegal goods will increase, thwarting the reduction of blackmarketing through trade liberalization. Yet, stepping up the enforcement measures which are geared to preventing blackmarketing itself will drastically reduce the extent of illegal transactions, since it increases the cost of blackmarketing and hence the price of the illegally transacted goods. What this study suggests is that the emergence of the black market in Korea should be attributed more to the excessive supply of duty-free goods imported through U.S. commissaries and exchanges than to the excessive demand for foreign goods. On the other hand, blackmarketing, in most cases, improves economic welfare, since it constitutes an increase in the "actual" amount of imported goods. Suppressing blackmarketing through stepped-up enforcement methods is beneficial only when the substitution effect of the legally transacted goods resulting from the increase in the price of the illegal goods prevails, since the increase in the demand for legal imports must override the decrease in the demand for black market goods as well as the negative income effect.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.171-181
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• 2021

The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley, malting barley, and naked oat plants, and to measure chlorophyll content, photosynthetic efficiency, and secondary compounds (total phenol, total flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) in plants grown at 13℃ or 25℃). Various types of barley seeds were collected from areas with ideal conditions for barley cultivation, hereinafter referred to as IA, and also from areas where barley cultivation is more difficult due to lower temperatures, hereinafter referred to as LTA. Seeds were tested for seed vigor. While there were significant differences in the electrical conductivity values between seeds collected from certain specific areas, no significant differences were evident between IA and LTA seeds, regardless of the type of barley seed. When plants were grown at 25℃, there were no significant differences in germination rates, plant height, root length and shoot fresh weight between plants originating from IA and LTA. However, there were differences in the measured parameters of some specific seeds. Similarly, under the low temperature condition of 13℃, no differences in the emergence rate, plant height, and shoot fresh weight were evident between plants originating from IA or LTA, regardless of the type of barley. However, there were differences between some specific seeds. One parameter that did vary significantly was the emergence date. Hulled barley and malting barley emerged 5 days after sowing, whereas naked oats emerged 7 days after sowing. There were no differences in the chlorophyll content and photosynthetic efficacy, regardless of the type of barley. There were no significant differences in total phenol, total flavonoid content, and DPPH radical scavenging activity between plants originating from IA and LTA, regardless of the type of barley. However, there were differences between some specific seeds. In particular, for malting barley the total flavonoid content differed in the order of Gangjin > Changwon > Haenam = Jeonju > Naju. The results indicate that crop growth, yield and content of secondary compounds in various types of barley may be affected by climate change.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.13-24
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• 2008

This study was carried out to provide basic information for the breeding of zoysiagrass synthetic varieties. For estimation of flowering periods, genetic characteristics, and cross-pollination rate, 5 combinations of zoysiagrass breeding lines were compared. Days to stigma emergence and anther exertion were observed in the field to calculate overlapping dates for cross-fertilization. Harvested seed from cross breeding combinations were planted to compare genetic characteristics using morphological traits of progenies. These data were used for determination of 7 phenotypic inheritance types with 8 morphological traits. Cross-pollination rates in 3 combinations of zoysiagrasses were estimated by using lower part color of grass shoots. Cross-pollination rates of zoysiagrass ranged from 11.3$\sim$48.9%, which indicated that zoysiagrass is an allogamous plant. When zoysiagrass breeding lines are properly combined, they may result in valuable synthetic cultivars.