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Double Cropping Productivity of Main Whole-Crop Silage Rice and Winter Feed Crops in the Central Plains of Korea (중부 평야지에서 사료용 벼와 주요 동계사료작물 이모작 시 생산성)

  • Ahn, Eok-Keun;Jeong, Eung-Gi;Park, Hyang-Mi;Jung, Kuk-Hyun;Hyun, Ung-Jo;Ku, Ja-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.4
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    • pp.311-322
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    • 2019
  • In order to establish an optimal double cropping system to obtain the maximum annual quantity, we investigated the annual productivity of whole-crop silage (WCS) rice, Jowoo (Jw), Yeongwoo (Yw), and Mogwoo (Mw), and winter feed crops (WFC), Italian ryegrass (IRG), Greenfarm (GF), rye Gogu (GU), and triticale Joseong (JS), in paddy fields of the central plains of Korea. From 2016 to 2019, each crop was subjected to two standard cultivation methods: WCS rice and WFC optimal. Using the WCS optimal mode, the average dry matter yield (DMY) of WCS rice, early flowering Jw, was 15.8 tons/ha and 21.0 for the mid-late heading Yw; there was no significant difference compared to the 19.2 tons/ha late-flowering Mw (p<0.01). The WFC were not significantly different between GF (3.2 tons/ha) and GU (4.5) sown on September 23rd, while JS was the highest at 12.6 tons/ha (p<0.001). There was a significant difference in the order of JS (16.6 tons/ha) > GF (10.5) > GU (4.7)(p<0.001) sown on October 11th. For JS sown on October 31st, the DMY was 11.8 tons/ha, which was significantly higher than that of the other two crops (p<0.05). Except for rye GU, DMY was the highest when sown on October 11th. For WFC optimal mode, the average DMY of JS was the highest at 18.3 tons/ha, which was significantly different from that of GF (10.9) and GU (9.6) (p<0.001). The DMY of WCS rice transplanted on May 10th was the highest at 23.0 tons/ha in Mw, which was not significantly different from that of Yw (21.4) but significantly different from that of Jw (15.9) (p<0.05). On transplanting on May 25th, the DMY of Mw was the highest at 24.2 tons/ha; this was not significantly different from that of Yw (20.7), but it was significantly different from that of Jw (18.6) (p<0.05). When transplanted on June 11th, the DMY was 21.3 tons/ha in Yw, which was significantly higher than the DMY of other two cultivars, Jw and Mw (p<0.05). For the WCS rice-WFC double cropping, the total annual DMY was 33.6 tons/ha with the combination of the WCS rice, Yw, and the triticale JS for WCS optimal mode. Meanwhile, the total annual DMY was 39.6 tons/ha with the combination of the triticale JS and the WCS rice, Yw, for WFC optimal mode. In conclusion, the strategies for obtaining the maximum yield of high-quality forage for WCS rice-WFC, WFC-WCS rice double cropping are as follows: 1) cultivation centered on the optimal mode of WFC, and 2) sowing the WFC, triticale JS in mid-October, harvesting the crops around the end of May and transplanting the WCS rice, Yw, in early June to obtain the maximum DMY of 39.6 tons/ha.

A Review of Personal Radiation Dose per Radiological Technologists Working at General Hospitals (전국 종합병원 방사선사의 개인피폭선량에 대한 고찰)

  • Jung, Hong-Ryang;Lim, Cheong-Hwan;Lee, Man-Koo
    • Journal of radiological science and technology
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    • v.28 no.2
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    • pp.137-144
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    • 2005
  • To find the personal radiation dose of radiological technologists, a survey was conducted to 623 radiological technologists who had been working at 44 general hospitals in Korea's 16 cities and provinces from 1998 to 2002. A total of 2,624 cases about personal radiological dose that were collected were analyzed by region, year and hospital, the results of which look as follows : 1. The average radiation dose per capita by region and year for the 5 years was 1.61 mSv. By region, Daegu showed the highest amount 4.74 mSv, followed by Gangwon 4.65 mSv and Gyeonggi 2.15 mSv. The lowest amount was recorded in Chungbuk 0.91 mSv, Jeju 0.94 mSv and Busan 0.97 mSv in order. By year, 2000 appeared to be the year showing the highest amount of radiation dose 1.80 mSv, followed by 2002 1.77 mSv, 1999 1.55 mSv, 2001 1.50 mSv and 1998 1.36 mSv. 2. In 1998, Gangwon featured the highest amount of radiological dose per capita 3.28 mSv, followed by Gwangju 2.51 mSv and Daejeon 2.25 mSv, while Jeju 0.86mSv and Chungbuk 0.85 mSv belonged to the area where the radiation dose remained less than 1.0 mSv In 1999, Gangwon also topped the list with 5.67 mSv, followed by Daegu with 4.35 mSv and Gyeonggi with 2.48 mSv. In the same year, the radiation dose was kept below 1.0 mSv. in Ulsan 0.98 mSv, Gyeongbuk 0.95 mSv and Jeju 0.91 mSv. 3. In 2000, Gangwon was again at the top of the list with 5.73 mSv. Ulsan turned out to have less than 1.0 mSv of radiation dose in the years 1998 and 1999 consecutively, whereas the amount increased relatively high to 5.20 mSv. Chungbuk remained below the level of 1.0 mSv with 0.79 mSv. 4. In 2001, Daegu recorded the highest amount of radiation dose among those ever analyzed for 5 years with 9.05 mSv, followed by Gangwon with 4.01 mSv. The area with less than 1.0 mSv included Gyeongbuk 0.99 mSv and Jeonbuk 0.92 mSv. In 2002, Gangwon also led the list with 4.65 mSv while Incheon 0.88 mSv, Jeonbuk 0.96 mSv and Jeju 0.68 mSv belonged to the regions with less than 1.0 mSv of radiation dose. 5. By hospital, KMH in Daegu showed the record high amount of average radiation dose during the period of 5 years 6.82 mSv, followed by GAH 5.88 mSv in Gangwon and CAH 3.66 mSv in Seoul. YSH in Jeonnam 0.36 mSv comes first in the order of the hospitals with least amount of radiation dose, followed by GNH in Gyeongnam 0.39 mSv and DKH in Chungnam 0.51 mSv. There is a limit to the present study in that a focus is laid on the radiological technologists who are working at the 3rd referral hospitals which are regarded to be stable in terms of working conditions while radiological technologists who are working at small-sized hospitals are excluded from the survey. Besides, there are also cases in which hospitals with less than 5 years since establishment are included in the survey and the radiological technologists who have worked for less than 5 years at a hospital are also put to survey. We can't exclude the possibility, either, of assumption that the difference of personal average radiological dose by region, hospital and year might be ascribed to the different working conditions and facilities by medical institutions. It seems therefore desirable to develop standardized instruments to measure working environment objectively and to invent device to compare and analyze them by region and hospital more accurately in the future.

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Effects of Immunoactivity on Ascaris suum Infection in Mice (마우스에 있어서 멱역활성이 돼지회충의 감염에 미치는 영향)

  • Lee, Jae-Gu;Park, Bae-Geun;Seo, Yeong-Seok
    • Parasites, Hosts and Diseases
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    • v.29 no.3
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    • pp.279-292
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    • 1991
  • The immune response to sheep red blood cell (sRBC) was monitored in the mice infected with Ascaris strum or Trichinella spiralis. The effects of the infection with T. spiralis or the injection with cyclophosphamide (CY) as an immunosuppression agent prior to challenge infection with the embryonated eggs of A. suum were monitored in mice by means of the level of infection with A. strum and cellular and humoral immune response to sRBC. following the oral administration of 1, 000 eggs of A. suum to mice, delayed-type hypersensitivity (DTH) and rosette-forming rate were gradually decreased and reached to the lowest levels at the 5th week and 6th week postinfection, respectively, and then returned to normal at the loth week. The hemagglutinin (HA) and hemolysin (HE) titers were gradually elevated and reached to peak at the 3rd week postinfection, and then returned to normal level. The appearance ratios of the eosinophils and mast cells were in peak at the 4th week and the 2nd week postinfection, respectively. Meanwhile the harvest ratio of A. suum larvae from the liver and lungs was 21.97% at the 1st week postinfection. Following the oral administration of 300 T. spiralis infective larvae, DTH and rosette-forming rate were gradually decreased with the lapse of time and reached the lowest values in the 30th and 21st day of postinfection, and then slightly increased and transiently decreased in the 70th and 80th day of postinfection, respectively. HA and HE titers were the lowest in the 21st and 90th day, whereas the ratios of eosinophils and mast cells were the highest on the 40th and 14th day posti nfecti on, ruts petit i vela. Following the intraperitoneal injection of CY, the body weight, the spleen weight, DTH, rosette-orming ratio, HA and HE titers, the number of WBC and the ratio of the mast cell were predominantly decreased in the 5th day, and then returned to the same value of the 1st day postinjection. The ratio of eosinophils was gradually decreased following to advance of days. At the 1st, 5th and loth days after intraperitoneal injection of CY of 400 mg/kg, a dose with 1, 000 eggs of A. suum was administered orally to mice, and harvest rate of the larvae at the 7th day postadministration was 7.07% in the 1st day, 14.94% in the 5th day, 10.1% in the loth day, 8.02% in control group. The effect of prior infection with infective larvae of T. spiralis upon immunological sequelae of a challenge infection of mice with embryonated eggs of A. suum in 30 or 70 days interval was checked. On the 37th day of prior infection with T. spiralis, that was the 7th day with A. suum postinfection, DTH and rosette-forming rate were drastically decreased, but the ratio of mast cells was highly increased and the ratio of eosinophils, HA and HE titers were fairly increased. On the other hand, the rate of larvae harvest was 9.3% in experimental group in contrast with 22.18% in control group. Meanwhile the effect of immune response to sRBC was similar to that of the former, but DTH and rosettt-forming rate were greatly decreased in the 77th day after prior infection with the 7th day after challenge infection in compariton with control. At that time, Ascaris larvae were harvested 8.3% in experimental group in comparison with 10.5% in control group.

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Evaluating efficiency of application the skin flash for left breast IMRT. (왼쪽 유방암 세기변조방사선 치료시 Skin Flash 적용에 대한 유용성 평가)

  • Lim, Kyoung Dal;Seo, Seok Jin;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.30 no.1_2
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    • pp.49-63
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    • 2018
  • Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

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The Effects of Self-regulatory Resources and Construal Levels on the Choices of Zero-cost Products (자아조절자원 및 해석수준이 공짜대안 선택에 미치는 영향)

  • Lee, Jinyong;Im, Seoung Ah
    • Asia Marketing Journal
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    • v.13 no.4
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    • pp.55-76
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    • 2012
  • Most people prefer to choose zero-cost products they may get without paying any money. The 'zero-cost effect' can be explained with a 'zero-cost model' where consumers attach special values to zero-cost products in a different way from general economic models (Shampanier, Mazar and Ariely 2007). If 2 different products at the regular prices of ₩200 and ₩400 simultaneously offer ₩200 discounts, the prices will be changed to ₩0 and ₩200, respectively. In spite of the same price gap of the two products after the ₩200 discounts, people are much more likely to select the free alternative than the same product at the price of ₩200. Although prior studies have focused on the 'zero-cost effect' in isolation of other factors, this study investigates the moderating effects of a self-regulatory resource and a construal level on the selection of free products. Self-regulatory resources induce people to control or regulate their behavior. However, since self-regulatory resources are limited, they are to be easily depleted when exerted (Muraven, Tice, and Baumeister 1998). Without the resources, consumers tend to become less sensitive to price changes and to spend money more extravagantly (Vohs and Faber 2007). Under this condition, they are also likely to invest less effort on their information processing and to make more intuitive decisions (Pocheptsova, Amir, Dhar, and Baumeister 2009). Therefore, context effects such as price changes and zero cost effects are less likely in the circumstances of resource depletion. In addition, construal levels have profound effects on the ways of information processing (Trope and Liberman 2003, 2010). In a high construal level, people tend to attune their minds to core features and desirability aspects, whereas, in a low construal level, they are more likely to process information based on secondary features and feasibility aspects (Khan, Zhu, and Kalra 2010). A perceived value of a product is more related to desirability whereas a zero cost or a price level is more associated with feasibility. Thus, context effects or reliance on feasibility (for instance, the zero cost effect) will be diminished in a high level construal while those effects may remain in a low level construal. When people make decisions, these 2 factors can influence the magnitude of the 'zero-cost effect'. This study ran two experiments to investigate the effects of self-regulatory resources and construal levels on the selection of a free product. Kisses and Ferrero-Rocher, which were adopted in the prior study (Shampanier et al. 2007) were also used as alternatives in Experiments 1 and 2. We designed Experiment 1 in order to test whether self-regulatory resource depletion will moderate the zero-cost effect. The level of self-regulatory resources was manipulated with two different tasks, a Sudoku task in the depletion condition and a task of drawing diagrams in the non-depletion condition. Upon completion of the manipulation task, subjects were randomly assigned to one of a decision set with a zero-cost option (i.e., Kisses ₩0, and Ferrero-Rocher ₩200) or a set without a zero-cost option (i.e., Kisses ₩200, and Ferrero-Rocher ₩400). A pair of alternatives in the two decision sets have the same price gap of ₩200 between a low-priced Kisses and a high-priced Ferrero-Rocher. Subjects in the no-depletion condition selected Kisses more often (71.88%) over Ferrero-Rocher when Kisses was free than when it was priced at ₩200 (34.88%). However, the zero-cost effect disappeared when people do not have self-regulatory resources. Experiment 2 was conducted to investigate whether constual levels influence the magnitude of the 'zero-cost effect'. To manipulate construal levels, 4 different 'why (in the high construal level condition)' or 'how (in the low construal level condition)' questions about health management were asked. They were presented with 4 boxes connected with downward arrows. In a box at the top, there was one question, 'Why do I maintain good physical health?' or 'How do I maintain good physical health?' Subjects inserted a response to the question of why or how they would maintain good physical health. Similar tasks were repeated for the 2nd, 3rd, and 4th responses. After the manipulation task, subjects were randomly assigned either to a decision set with a zero-cost option, or to a set without it, as in Experiment 1. When a low construal level is primed with 'how', subjects chose free Kisses (60.66%) more often over Ferrero-Rocher than they chose ₩200 Kisses (42.19%) over ₩400 FerreroRocher. On contrast, the zero-cost effect could not be observed any longer when a high construal level is primed with 'why'.

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Studies on the Biological Effects of Chemosterilant, Hempa, on the Rice Weevil (Sitophilus oryzae 1.) and Transmission of Sterility (화학적 불임유기물질 Hempa가 쌀바구미(Sitophilus oryzae L.)에 미치는 생물학적 영향 및 불임성의 전달에 관한 연구)

  • Shim Jai Wook
    • Korean journal of applied entomology
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    • v.12 no.1
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    • pp.1-21
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    • 1973
  • Some experiments were conducted to investigate the effects of the chemosterilant, hempa, on the biology of the rice weevil, Sitophilus oryzae L., and the transmission of the lethal factors in the progeny. One to three days old adult males were fed on the wheat grains treated with concentrations of 0.0625, 0.125, 0.25, and $0.5\%$ of hempa water solution. The effects of the treatment on the mortality, longevity, and the performance of oviposition were examined for the Pl generation, and the hatchability and mortality in the postembryonic development were also tested in the $F_1,\;F_2,\;BC_1,\;F_3,\;and\;BC_2$ generations to analyze the inheritance of the lethal factors. The results obtained were summarized as follows. (1) The average longevity of the treated males were ranged from 26.6 to 30.4 days, and indicated no statistical differences. (2) The mortality of the treated males were ranged between $3.3\%\;and\;13.3\%$ and showed no statistical significance. (3) The overall mean number of eggs laid by a female mated to a treated male with concentrations of 0.0625, 0.125, 0.26 and $0.5\%$ were 3.78, 4.05, 3.75 and 3.61 for the respective treatments, and they were not differ significantly from those of control which were 3.60 per female per 3 day period. The unmated female laid 1.91 in the same period, and significantly differ from those in other experimental groups. (4) The overall mean hatchability of the eggs laid by the females mated with males that had been treated with various concentrations of hempa were 86.82, 64.77, 53.47, 40.33 and $24.78\%$ for the respective concentrations of 0, 0.0625, 0.125, 0.25 and $0.5\%$. The hatchability decreased with the increasing concentrations. (5) The minimum hatchabilities were obtained from the eggs laid in the period of 10-12 days after treatment, then the hatchability increased showing some recovery. The recovery seemed to be very much delayed for the males which had been treated with the greater concentrations. Such a difference in hatchability might be related with the sensitivity of the developmental stages of the sperms, and broader spectrum in the stages and severer effects seemed to be associated with the increased concentrations. (6) The overall mean of larval mortality in the $F_l$ generation were 6.55, 17.89, 27.40, 35.42 and $52.17\%$ for the respective concentrations of 0,0.0625, 0.125,0.25 and $0.5\%$. And there was a tendency to increase in the mortality with the increase of concentrations. (7) The correlation coefficients between per cent sterile eggs and larval mortality for the experimental plots of 0.125, 0.25 and $0.5\%$ treatments showed r=+0.83 and +0.85, respectively, and it seemed to be close correlation between the lethal effects on the embryonic and post-embryonic developments. (8) Since the $SC_{50}$ of the sterile eggs was $0.133\%$ and $SC_{50}$ of the larval mortality was $0.565\%$, it was considered that tile lethal factors expressed more in the egg stages than the larval stages. (9) The ratio of female to male in the $F_l$ adults showed 100 : 125, 100 : 108 and 100 : 124 for the plots of 0.125, 0.25 and $0.5\%$ treatments, respectively. And it n·as considered that the sex ratio distortions might occur with the higher concentrations. (10) When the F, males originated 1.on the eggs had been laid by p, in the period of 16-18 days after treatment, were crossed to normal females $(BC_1)$ and made sib matings $(F_2)$, the per cent sterile eggs of the $BC_1$ generation were 13.88 and $33.04\%$ , and were 31.01 and $38.73\%$ for the $F_2$generation with the plots of 0.0625 and $0.125\%$ treatment, respectively. And these seemed to be a results of the $F_1$ individuals are carrying some chromosomal aberrations (11) The larval mortality was the highest in the $F_2$ plot and followed the female backcross plot, and the least in the male backcrosses. (12) The proportions of 1st and 2nd instar larvae among the larval development at tile 17th day after oviposition were 10.98, 27.26, 32.98 and $15.73\%$ in the normal female $\times$ normal male, $F_1$ female$\times$normal male, normal $female \;\times F_1$ male and $female \;\times F_1$ male plots, respectively. It was considered that the larval development might be delayed by the treatment in the 2nd generation. (13) Per cent larval mortality and sterile eggs were greater in the $F_2$ sib mating plots $(F_3)$ than both of $F_2$ backcrosses. Therefore, it seemed that some of the recessive lethal mutations might affect in the further generations. (14) The sterility, induced by the treatment of chemosterilant, hempa, was considered as the result of the dominant lethal mutations due to chromosomal aberrations such as translocation and/or deletion. The effects of these lethal factors seemed to be inherited tip to 3rd generation after treatment.

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Multiplication of Infectious Flacherie and Densonucleosis Viruses in the Silkworm, Bombyx mori (가잠의 전염성 연화병 및 농핵병 바이러스 증식에 관한 연구)

  • 김근영;강석권
    • Journal of Sericultural and Entomological Science
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    • v.25 no.2
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    • pp.1-31
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    • 1984
  • Flacherie, as one of the most prevalent silkworm diseases, causes severe economic damage to sericultural industry and its pathogens have been proved to be flacherie virus (FV) and densonucleosis virus (DNV). Multiplications of the viruses in the larvae of the silkworm, Bombyx mori, were studied by the sucrose density gradient centrifugation and electron microscopy. The quantitative and qualitative changes of nucleic acids and proteins were investigated from the midgut and hemolymph in the silkworm larvae infected separately with FV and DNV. The histopathological changes of epithelial cells of infected midgut also were examined by an electron microscope. 1. Purified fractions of FV or DNV in a sucrose density gradient centrifugation yielded one homogenous and sharp peak without a shoulder, suggesting no heterogenous materials in the preparation. Electron microscopy also revealed that FV and DNV were spherical particles, 27nm and 21nm in diameter, respectively. 2. Silkworm larvae showed a decrease in body weight on the 6th day and in midgut weight on the 3rd day after inoculation with FV or DNV. 3. DNA content was higher in the midgut when infected with FV or DNV, but the hemolymph of the infected larvae showed no difference during first 6 days after inoculation, after which DNA concentration declined rapidly. 4. RNA synthesis of silkworm larvae infected separately with FV and DNV was stimulated in the midgut, but RNA content was reduced in the hemolymph at the early stage of virus multiplication. At the late stage of virus multiplication, however, it was extremely reduced in both midgut and hemolymph. 5. The concentration of protein in the midgut and hemolymph of silkworm larvae infected separately with FV and DNV showed no difference from that of the healthy larvae at the early stage of virus multiplication, but it was significantly reduced at the late stage of virus multiplication. 6. There was no difference in the electrophoretic patterns of RNAs extracted from the midgut of healthy or virus-infected larvae. 7. The electrophoresis of proteins extracted from the midgut infected with FV or DNV, when carried out on the 1st and 5th day after virus inoculation, showed no difference from that of the healthy larvae. But, there was an additional band with medium motility in the proteins on the 8th day after virus inoculation, while a band with low mobility shown in the proteins of healthy larvae disappeared in the infected larvae. However, a band with high mobility in the healthy larvae was separated into two fractions in the infected larvae. 8. The electrophoretic pattern of hemolymph proteins of the silkworm larvae infected separately with FV and DNV was similar to that of the healthy larvae, but the concentration of hemolymph proteins in the infected larvae was lower than that of the healthy larvae at the late stage. 9. Two types of inclusion bodies were shown by the double staining of pyronin-methyl green in the columnar cell of the midgut on the 8th day after FV inoculation. 10. Electron microscopy of the infected midgut revealed that the 'cytoplasmic wall' of the goblet cell thickened on the 5th day after FV inoculation and several types of the cytopathogenic structures, such as virus$.$specific vesicles, virus particles, linear structures, tubular structures, and high electron-dense matrices were observed in the cytoplasm of the goblet cell. The virus particles were also observed in the microvilli and the structures similar to spherical virus particles were observed around the virus-specific vesicles, suggesting the virus assembly in the cytoplasm. 11. Fluorescence micrograph of the infected midgut stained with acridine orange showed that the nucleus, the site of DNV multiplication in the columnar cell, enlarged on the 5th day after virus inoculation. 12. Electron microscopic examination of DNV infected midgut revealed that the nucleolus of the columnar cell was broken into granules and those granules dispersed into apical region of the nucleus on the 5th day after virus inoculation. On the 8th day after inoculation, it was also observed that the nucleus of the columnar cell was full with the high electron-dense virogenic stroma which were similar to virus particles. These facts suggest that the virogenic stroma were the sites of virus assembly in the process of DNV multiplication.

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Inflammatory Reponse of the Lung to Hypothermia and Fluid Therapy after Hemorrhagic Shock in Rats (흰쥐에서 출혈성 쇼크 후 회복 시 저체온법 및 수액 치료에 따른 폐장의 염증성 변화)

  • Jang, Won-Chae;Beom, Min-Sun;Jeong, In-Seok;Hong, Young-Ju;Oh, Bong-Suk
    • Journal of Chest Surgery
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    • v.39 no.12 s.269
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    • pp.879-890
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    • 2006
  • Background: The dysfunction of multiple organs is found to be caused by reactive oxygen species as a major modulator of microvascular injury after hemorrhagic shock. Hemorrhagic shock, one of many causes inducing acute lung injury, is associated with increase in alveolocapillary permeability and characterized by edema, neutrophil infiltration, and hemorrhage in the interstitial and alveolar space. Aggressive and rapid fluid resuscitation potentially might increased the risk of pulmonary dysfunction by the interstitial edema. Therefore, in order to improve the pulmonary dysfunction induced by hemorrhagic shock, the present study was attempted to investigate how to reduce the inflammatory responses and edema in lung. Material and Method: Male Sprague-Dawley rats, weight 300 to 350 gm were anesthetized with ketamine(7 mg/kg) intramuscular Hemorrhagic Shock(HS) was induced by withdrawal of 3 mL/100 g over 10 min. through right jugular vein. Mean arterial pressure was then maintained at $35{\sim}40$ mmHg by further blood withdrawal. At 60 min. after HS, the shed blood and Ringer's solution or 5% albumin was infused to restore mean carotid arterial pressure over 80 mmHg. Rats were divided into three groups according to rectal temperature level($37^{\circ}C$[normothermia] vs $33^{\circ}C$[mild hypothermia]) and resuscitation fluid(lactate Ringer's solution vs 5% albumin solution). Group I consisted of rats with the normothermia and lactate Ringer's solution infusion. Group II consisted of rats with the systemic hypothermia and lactate Ringer's solution infusion. Group III consisted of rats with the systemic hypothermia and 5% albumin solution infusion. Hemodynamic parameters(heart rate, mean carotid arterial pressure), metabolism, and pulmonary tissue damage were observed for 4 hours. Result: In all experimental groups including 6 rats in group I, totally 26 rats were alive in 3rd stage. However, bleeding volume of group I in first stage was $3.2{\pm}0.5$ mL/100 g less than those of group II($3.9{\pm}0.8$ mL/100 g) and group III($4.1{\pm}0.7$ mL/100 g). Fluid volume infused in 2nd stage was $28.6{\pm}6.0$ mL(group I), $20.6{\pm}4.0$ mL(group II) and $14.7{\pm}2.7$ mL(group III), retrospectively in which there was statistically a significance between all groups(p<0.05). Plasma potassium level was markedly elevated in comparison with other groups(II and III), whereas glucose level was obviously reduced in 2nd stage of group I. Level of interleukine-8 in group I was obviously higher than that of group II or III(p<0.05). They were $1.834{\pm}437$ pg/mL(group I), $1,006{\pm}532$ pg/mL(group II), and $764{\pm}302$ pg/mL(group III), retrospectively. In histologic score, the score of group III($1.6{\pm}0.6$) was significantly lower than that of group I($2.8{\pm}1.2$)(p<0.05). Conclusion: In pressure-controlled hemorrhagic shock model, it is suggested that hypothermia might inhibit the direct damage of ischemic tissue through reduction of basic metabolic rate in shock state compared to normothermia. It seems that hypothermia should be benefit to recovery pulmonary function by reducing replaced fluid volume, inhibiting anti-inflammatory agent(IL-8) and leukocyte infiltration in state of ischemia-reperfusion injury. However, if is considered that other changes in pulmonary damage and inflammatory responses might induce by not only kinds of fluid solutions but also hypothermia, and that the detailed evaluation should be study.

Seasonal Variations of Water Quality in the Lower Part of the Nagdong River (낙동강 하류수질의 계절적 변화)

  • KIM Yong-Gwan;SHIM Hye-Kung;CHO Hak-Rae;YOU Sun-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.6
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    • pp.511-522
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    • 1984
  • The Nagdong is one of the biggest rivers in Korea, which is very important water source not only for tap water of Pusan city but also for the industrial water. Therefore, authors tried to check the water quality year by year. In this experiment one hundred and twenty water samples collected from August 1983 to July 1984 were analyzed bacteriologically and physiologically. Fifteen sampling stations were established between near Samrangjin and estuary of the river. To evaluate the water quality, temperature, pH, chloride ion, salinity, chemical oxygen demand (COD), electrical conductivity, nutrients, total coliform, fecal coliform, fecal streptococcus, viable cell count and bacterial flora were observed. The variation of water temperature was ranged $-1.5{\sim}29.0^{\circ}C$ (Mean value $13.9{\sim}16.5^{\circ}C$), it in spring was higher as $10{\sim}15^{\circ}C$ about $10^{\circ}C$ than in winter and it in autumm was very stabilized as about $20^{\circ}C$ at each station. The pH variation of the samples was ranged $6.68{\sim}9.15$. The range of concentration of chloride ion and salinity varied $7.4{\sim}l,020.5$ mg/l and $1.05{\sim}33.0\%0$, respectively. Especially, salinity of the 3rd water war was the higher than others as $25.76{\sim}31.58\%0$. COD was ranged $1.45{\sim}14.94$ mg/l and the lower part of the Nagdong River was heavily contaminated by domesitc sewage and waste water from the adjacent factor area. The range of electrical conductivity was $1.360{\times}10^2{\sim}5.650{\times}10^4{\mu}{\mho}/cm$ and that was by far higher the estuary than the upper. Concentration of nutrients were $0.008{\sim}0.040$ mg/l (Mean value $0.019{\sim}0.068$ mg/l) for $NO_2-N,\;0.038{\sim}5.253$ mg/l ($0.351{\sim}2.347$ mg/l) for $NO_3-N,\;0.100{\sim}2.685$ mg/l($0.117{\sim}1.380$ mg/l) for $NH_4-N,\;0.003{\sim}0.084$ mg/l($0.014{\sim}0.065$ mg/l) for $PO_4-P$ and $0.154{\sim}6.123$ mg/l ($1.165{\sim}3.972$ mg/l) for $SiO_2-Si$, respectively. Usually nutrients contents of the water in the upper part(included station 1 to 5) were higher than those of the estuarine area. The bacterial density of the samples ranged 7.3 to 460,000/100 ml for total coliforms, 3.6 to 460,000/100 ml for fecal coliform, $0{\sim}46,000/100ml$ for fecal streptococcus and $<30{\sim}1.2{\times}10^5/ml$ for viable cell count. Composition of coliform was $28\%$ Escherichia coli group, $18\%$ Citrobacter freundii group, $31\%$ Enterobacter aerogenes group and $22\%$ others. Predominant species among the 659 strains isolated from the samples were Pseudomonas spp. ($42\%$), Flavobacterium spp. ($20\%$) and Moraxella spp. ($12\%$).

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Ecological Studies on the Transition of Sheath Blight of Rice in Korea (한국(韓國)에서의 벼 잎집무늬마름병 발생변동(發生變動)에 관(關)한 생태학적(生態學的) 연구(硏究))

  • Yu, Seung-hun
    • Korean Journal of Agricultural Science
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    • v.4 no.2
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    • pp.283-316
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    • 1977
  • In an attempt to obtain a basic information to develop an effective integrated system of controlling sheath blight of rice in Korea, the transition of this disease, the variation of cultural characters and pathogenicity of the pathogen, environmental conditions affecting the disease outbreak and varietal resistance have been investigated. 1. Rice sheath blight which has been minor disease in the past was widely spread, especially since 1971. This disease has promptly spread all over the country and infected 65.2% of total rice growing area in 1976. Various factors are considered to be related to such transition of this disease. Above all, increace of application of nitrogenous fertilizer, early season and earlier cultivation of rice, introduction of more susceptible "Tongil" varieties etc. must be important factors influencing the outbreak of this disease. 2. Great variations in cultural characteristics-such as mycelial growth rate, color of the medium, amount of the aerial mycelium, shape and color of the sclerotia- and in the pathogenicity of isolates of the pathogen, Thanatephorus cucumeris Dank were observed. The optimum temperature for mycelial growth also varied with isolates, from $25^{\circ}C$ to $30^{\circ}C$. There were not necessarily any correlation between curtural characteristics and pathogenicity of isolates of Thanatephorus cucumens. 3. Mycelial grow th of isolates of Thanatephorus cucumens on the PDA medium were correlated with the air temperatures of the region where the isolates were collected. The isolates from the regions with high temperature grew well on PDA medium at $35^{\circ}C$ than those from the region with low temperature, on the other hand, the isolates from the regions with the low temperature grew well on the same medium at $12^{\circ}C$ than those from the regions with high temperature. 4. Pectin polygalacturonase (PG) and cellulase (Cx) were most active on the 3rd day after inoculation on the leaves of rice plant with Thanatephorus cucumeris, whereas pectin methylestrase (PE) was most active on the 4th day after inoculation. Relationship between the activities of PE of isolates and the strength of pathogenicity of isolates was obtained, but PG and cellulase activities were not correlated with pathogenicity of isolates. 5. The tolerence of sclerotia from in-vitro culture to low temperature varied with their water content, the dried cultural sclerotia were more tolerent than wet ones, Dried cultural sclerotia maintained almost 100% germinability for 45 days at $-20^{\circ}C$, whereas wet sclerotia lost viability at $-5^{\circ}C$. The germination ratio of the sclerotia after overwintering changed from 18% to 70% according to the water content of the test paddy fields and the ratio was low in wet paddy condition. 6. To investigate the host range of this fungi in and near paddy field, 17 weeds were inoculated with fungi. The lesions of sheath blight disease was obserbed on Sagittaria trifolia L., Echinochloa crusgalli P. Beauv., Monochoria vaginal is Presl, Polygonum Hydropiper L., Eclipta prostrata L., Digitaria sanguinalis Scapoli. 7. When the level of nitrogen applied was doubled over standard level, total nitrogen content in rice sheath increased, ami when silicate was applied, starch content in rice sheath decreased, inducing the rice plants more susceptible to sheath blight disease. Increased dressing of potash ferilizer reduced the incidence of sheat blight disease. 8. The percentage of infected stems in the early period increased more in the narrow hill plot than in the wide hill plot, but in the late period this tendency was inversed; the percentage of infected stems as well as severity in the wide hill plot increased more compared to the narrow hill plot, and the disease severity in the one plant per hill plot was also low. The number of stems in the wide hill plot was more than the number of stems in the narrow hill plot. This indicates that the microclimate, such as the relative humidity, in the narrow hill plot was more favorable for the development of this disease. 9. There was a high negative correlation between the disease severity of varieties to the sheath blight and the maturity of the varieties, that is, the early varieties were more susceptible than the late ones, and much-tillering varieties usually showed more infection than less tillering varieties. 10. No relationship was obtained between the percentage of infected stems in the early period and the severity after heading, whereas a distinct relationship was obtained between former and latter after Aug. 10.

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