• Journal of Sericultural and Entomological Science
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• v.8
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• pp.41-50
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• 1968

In order to achieve efficiency of laying eggs of silkworms, it is very important to eliminate noncocooning silkworms. This study is written on the basis of observation and analysis of mechanism of silkworms physiologically and anatomically. It is hoped that given herein will contribute to the effecting elimination work. Outline of the study summarize as follows: 1. It is observed through microscope that the silkworms which are seen normal state in the silk gland but no ability of cocoon making have polyhedrosis in the nerve, trachea and muscle near the tissue of the spinneret. 2. Relatively high proportion of non-cocooning silkworms are caused by the grasserie of the silkworms. 3. As a result of inoculation with purulent discharges against silkworms from first fooding through 8th day of 5th instar, number of cocooning silkworms were increased when inoculation are applied at laterer day of the instar. In the case of non-cocooning silkworms, meanwhile, resulted not big varriation when it is apllied in the early and middle of the period, but number of non-cocooning silkworm was reduced when the inoculation are given at laterer of the instar. Number of death during rearing and mounting are increased when earliest application of inoculation are carried out. 4. Symptom of grasserie was appeared more or less three days after application of the inoculation. Some silkworms which were inoculated just before mounting has ability of cocooning making even taken grasserie, in this case the silkworm can make thin cocoon. since the silkworm fall sick during cocoon making and unable of spinning soon. when the worm was affected by grasserie slightly, it was observed that the silkworm can spinning. It is supposed to be the light paralysis of spinneret is not very much influenced to spinning. 5. As a result of observation of original stock and hybrid including other 44 kinds of silkworm, many non-cocooning silkworms were found in the original stock especially originated from japanese than in hybrid. 6. A number of undulations are found in the middle division of the silk gland of non-cocooning silkworms. 7. According to the observation of the sizes of the body and digestive organs, normal natured silkworms and non-cocooning silkworms are more or less same in length, but the width, circumference of bodies and digestive organs were more larger in the later. If silkworm which was in the period of active eating of 5th instar was given shock of dropping to the floor, the silkworm receives little more shock when hit to side of the body than to head, and concrete floor than ondol and wooden floor.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.237-244
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• 2012

Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV) cause severe diseases in winter barley in Europe and East Asia. We investigated the effect of different level of resistance to virus disease on the plant growth and yield in whole-crop barley. In the virus infection, BaYMV was detected all tested cultivars in first diagnosis at 30th March. BaYMV infection was identified only in the susceptible Sunwoobori in 6th April, but not in the Yuyeon (moderate, M) and Youngyang (moderate resistant, MR) cultivars. Plant height was restrained about 14.6~32.9% in overwintered plant regeneration stage depending on the resistance of each cultivar. The tiller numbers also reduced to 8.7~19.7% by BaYMV infection in overwintering season. We evaluated culm length, spike length, and spike number in the virus-infected field and non-infected field. For the culm length, Youngyang (MR) reduced only 14.5% by BaYMV. However Sunwoo (susceptible, S) and Yuyeon (M) cultivars were decreased to 24.8~42.7%. The spike length and spike number also affected to 8.9~21.3% and 24.3~31.0%, respectively, depending on the resistance. After harvesting, dry-matter yield of whole crop yield reduced by approximately 21.6~58.0% according to cultivar resistant degrees. For example, Sunwoobori (S) decreased 58.0% in comparing to non-infected field. The grain yield was also significantly reduced in virus infected cultivars. Sunwoobori (S) was severely decrease more than 60.0%. Yuyeonbori (M) and Youngyangbori (MR) also decreased 30.0~47.5% by the viral infection comparing to those in the non-infected field.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.251-260
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• 2011

This study was carried out to compare growth characteristics and yield of silage corn hybrids at four different regions (Hwaseong, Dangjin, Gochang and Pyeongchang). Two domestic corn hybrids, 'Kwangpyeongok' and 'Gangdaok', and two imported corn hybrids, 'P3394' and '32P75' were used in this study. Plant height and ear height ratio were not significantly different among corn hybrids. 'Kwangpyeongok' was the strongest of all corn hybrids for lodging. The others except 'Kwangpyeongok' were similar to lodging. All corn hybrids were excellent to stay-green. Incidence of southern corn leaf blight (Bipolaris maydis) was low at all corn hybrids. '32P75' was 10.1%, the most of all corn hybrids for incidence of BSDV (black streaked dwarf virus). 'Kwangpyeongok' and 'Gangdaok' were stronger than '32P75' for BSDV. Fresh yield of 'Kwangpyeongok' and 'Gangdaok' were the most of all corn hybrids as 74.85 and 76.68 ton/ha and 'P3394' was the least of all corn hybrids as 64.97 ton/ha. Dry matter yield as 18.83~21.92ton/ha and TDN yield as 12.73~14.52 ton/ha were not significantly different among corn hybrids.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.359-370
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• 2021

Purpose To analyze the findings and serial changes in chest CT lesions in 123 symptomatic patients with coronavirus disease 2019 (COVID-19). Materials and Methods From February 19 to April 7, 2020, a total of 123 confirmed COVID-19 patients (male, 44; female, 79; mean age, 59.2 ± 18.6) were enrolled in this retrospective study. A total of 234 CT scans were reviewed for the following patterns: acute alveolar insult (AAI) patterns: ground-glass opacity (GGO), crazy-paving appearance, mixed pattern, and consolidation; organizing pneumonia (OP) patterns: perilobular patterns, band opacity, curvilinear opacity, reversed halo opacity, and small nodular consolidation; resolving patterns: pure GGO, remnant curvilinear, small nodular consolidation, and serial changes of lung abnormalities. We compared the proportions of AAI pattern, OP pattern, or resolving pattern with time progression and analyzed the association between the patterns and disease severity using Pearson chi-square and Fisher's exact test. Results Predominant CT patterns were AAI pattern (87%) in the early hospital period group (0-10 days, after the onset of symptoms), OP pattern (45.7%) in the later hospital period group (after 10 days), and resolving pattern in discharge and follow-up group (47.2% and 84.8%, respectively). The difference in the proportions of predominant CT patterns with time progression was statistically significant (p < 0.001, Pearson's chi-square test). No statistically significant association was observed between the patterns and disease severity (p = 0.055, Fisher's exact test). No fibrous changes in the lesions were observed on follow-up CT scans. Conclusion The serial CT scans of COVID-19 patients showed the spectrum of COVID pneumonia CT manifestations as different phases of lung injury and repair.