• Title/Summary/Keyword: Dark spots

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First report of red bean brown leaf blight caused by Rhizopus arrhizus (syn. R. oryzae) (Rhizopus arrhizus (syn. R. oryzae)에 의한 팥 갈색잎마름병 첫 보고)

  • Seongkyun Lee;Jieun Yeon;Eunsol Yeon;Jongok Jeon;Hyunman Shin;Ju-Hyung Kim;Sangbeom Lee
    • Korean Journal of Environmental Biology
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    • v.41 no.4
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    • pp.677-682
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    • 2023
  • Milky white spots appeared on red bean leaves in a red bean cultivation area located in Jangyeon-myeon, Goesan-gun, Chungbuk Province. After culturing the pathogen in PDA medium, their morphology was observed, and their genes were BLAST-searched in the National Center for Biotechnology Information (NCBI). The pathogen was identified as a fungus called Rhizopus arrhizus. As a result of reinoculating the isolated pathogen on red beans, the same symptoms as those in the isolated leaves occurred. Characteristic colonies of R. arrhizuson PDA medium initially showed a bright color and then changed to dark gray over time, with mostly spherical sporangia. The sporangiospores were spherical or elliptical, mostly irregular, and small in size. Therefore, based on these results, this disease has not yet been reported in red beans and was called red bean brown leaf blight caused by Rhizopus arrhizus A. Fisch (syn. R. oryzae).

First Report of Anthracnose Caused by Colletotrichum sojae on Peanut in Korea (Colletotrichum sojae에 의한 땅콩 탄저병 발생 보고)

  • Shinhwa Kim;Soo Yeon Choi;Hyunjung Chung;Nak Jung Choi;Bo Yoon Seo;Sang-Min Kim
    • The Korean Journal of Mycology
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    • v.52 no.1
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    • pp.55-60
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    • 2024
  • In August 2023, leaf spot disease was observed in peanuts in Cheongju-si, Korea. Leaf spots occurred at the leaf margins and the lesions gradually expanded. Diseased leaf areas were light or dark brown and irregular in shape. A fungal isolate was obtained from symptomatic leaf and cultured on potato dextrose agar (PDA) medium at 25℃. An isolate was identified as Colletotrichum sojae based on morphological characteristics and sequences of the internal transcribed spacers, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase-1, actin, and 𝛽-tubulin genes. Pathogenicity tests were performed on peanut seedlings in a conidial suspension (1×106 conidia/mL). Lesions were observed on the peanut leaf 5 d after inoculation. The pathogen was re-isolated from the lesions of the inoculated leaves. To the best of our knowledge, this is the first report of anthracnose on peanut caused by C. sojae in Korea.

Analysis of the influence degree of each factor on the linkage affecting the lever actuating force in an implant transport device for the treatment of eye diseases (안과질환 처치를 위한 임플란트 수송장치에서 레버 작동력에 영향을 주는 연동장치에 대한 인자별 영향도 분석 )

  • Jeong-Won Lee;Joong-Seob Guk
    • Design & Manufacturing
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    • v.18 no.3
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    • pp.1-8
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    • 2024
  • Macular degeneration is a disease that damages the macula, the center of the retina, and is one of the three major eye diseases along with glaucoma and diabetic retinopathy. The optic nerve and most of the photoreceptor cells are located here, and since this is where images of objects are formed, it is the most important area for vision. The main symptom of macular degeneration is the inability to clearly distinguish the shape of objects or the inability to distinguish colors and light and dark. It is also a serious eye disease that causes black spots in the center of the field of vision. However, it is difficult to distinguish it from the form of vision loss due to presbyopia, so early diagnosis is often missed. The most common treatment for macular degeneration is antibody injection therapy. This treatment requires regular injections once every 1-2 months. When receiving antibody injection therapy, the fear of having to inject directly into the eye and the cost of long-term repeated procedures are a great burden to patients. To overcome these problems, special sustained-release formulations using drug delivery systems are being developed. Since the release speed and release time of the drug can be controlled, the number of times the drug is administered can be drastically reduced. However, the implant (Ø 0.46×6.0mm), which is a sustained-release agent, is manufactured by mixing biodegradable resin (PLGA) and therapeutic agent in a ratio of 4:6, so it is very brittle and there is a high risk of implant damage during handling. In order to safely insert the implant into the eye, a transport device that can be driven with controlled force is required. Therefore, in this study, the lever operating force was measured and analyzed to determine the influence of factors according to the cross-sectional thickness and shape of the linkage produced through injection molding as well as the post-process.

The Past, Present and Future of Imaging Enhanced Endoscopy in Colon Tumor (대장 종양에서의 영상 증강 내시경 이용의 과거와 현재, 미래)

  • Kyueng-Whan Min;One-Zoong Kim
    • Journal of Digestive Cancer Research
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    • v.12 no.2
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    • pp.90-101
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    • 2024
  • The incidence of colon cancer in South Korea has recently been the highest among gastrointestinal cancers. Early diagnosis is critical, and image-enhanced endoscopy (IEE) is a key diagnostic method. Colon tumors primarily include serrated polyps, adenomatous polyps, and colon cancer. Early endoscopic techniques relied on simple visual inspection for diagnosis, with tumor size and shape being the primary considerations. Low-resolution images made these methods ineffective for detecting small or early-stage lesions. IEE now enables detailed examination using high-resolution images and various color and structure analyses. Techniques like narrow band imaging (NBI) allow precise observation of vascular patterns and surface structures. Hyperplastic polyps often appear similar in color to the surrounding mucosa, with no visible vascular pattern. Sessile serrated lesions have a cloudy surface with distinct boundaries and irregular patterns, often with black spots in the crypts. Adenomatous polyps are darker brown, with a visible white epithelial network and various pit patterns. Magnified images help differentiate between low- and high-grade dysplasia, with low-grade showing regular patterns and high-grade showing increased irregularities. The NBI International Colorectal Endoscopic classification identifies malignant colon tumors as brown or dark brown with disorganized vascular patterns. The Japan NBI Expert Team classification includes loose vascular areas and disrupted thick vessels. The Workgroup serrAted polypS and Polyposis classification aids in differentiating between hyperplastic polyps and sessile serrated lesions/adenomas when deciding whether to resect polyps larger than 5 mm. Suspected high-grade dysplasia warrants endoscopic submucosal dissection and follow-up. Future advancements in IEE are expected to further enhance early detection and diagnostic accuracy.

Banana Blast Caused by Pyricularia angulata Hashioka (Pyricularia anguiata Hashioka에 의한 바나나 도열병 (가칭))

  • Kim Wan Gyu;Kim Chang Kyu;Lee Eun Jong
    • Korean Journal Plant Pathology
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    • v.3 no.2
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    • pp.114-119
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    • 1987
  • Banana blast was frequently encountered in greenhouses of Jeju province during a local survey of plan diseases from 1985 to 1986. The disease incidence on banana was very severe up to $100\%$ in a greenhouse. The causal fungus was identified as Pyricularia angulata Hashioka based on mycological characteristics and Path genicity of the fungus. The symptom of blast produced on leaves of banana was circular to oval, dark brow spots with yellow margins which measured 1-10mm in diameter, and the symptom on fruits was circular to oval reddish brown or dark brown, depressed spots which measured up to 20mm in diameter. The symptoms were scattered not only on leaves and fruits of banana but. also on petioles, leaf sheaths, bunch stalks and crowns The pathogen was characterized that conidia were hyaline, 2 septated, ovate to pyriform with a small hilum solitary at ends of den tides of conidiophores, and measured $16.0-34.0\times7.0-12.0{\mu}m$ (average $22.5\times9.0{\mu}m$) and conidiophores were mostly 2 septated, occasionally 2 or 3 branched, denticulate at the tips, and measured $7.5-100.0\times3.0-5.0{\mu}m$(average $90.0\times4.0{\mu}m$). The optimum temperature range for mycelial growth of the fungus on PDA was $26-28^{\circ}C$. The result of pathogenicity tests revealed that P. angulata had pathogenicity only on banana. On the other hand Pyricularia grisea (Cke.) Sacc. isolated from Digitaria sanguinalis(L.) Scopo. was not pathogenic to banana. It was revealed that the leaves were the most susceptible to P. angulata among several parts of banana in inoculation tests. Thirty-day-old fruits of banana were more susceptible to the fungus than 60-day-old fruits, and bunch stalks were more susceptible than the fruits.

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Soybean Sprout Rot Caused by Colletotrichum species (Colletotrichum species에 의한 콩나물 부패)

  • Kim, Yong-Ki;Ryu, Jae-Ki;Ryu, Jae-Dang;Lee, Sang-Yeop;Lee, Seong-Don
    • Research in Plant Disease
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    • v.8 no.3
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    • pp.175-178
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    • 2002
  • Two novel casual agents of soybean sprout rot occurred at soybean sprouts cultivated under structure in Suwon area in 1997 were isolated and their pathogenicity was tested in vivo. An isolate formed crowed, black acervuli which were oval to elongated with numerous black, needlelike, intermixed long and short setae, 65~110$\times$3.5~6.6 ${\mu}{\textrm}{m}$. Conidia were curved, lunate, unicellular and hyliane and measured 21.5~22.5$\times$3.5~4.0 ${\mu}{\textrm}{m}$. The other isolate produced conidia with straight and cylindrical, and measured 14.0~17.5$\times$3.5~4.5 ${\mu}{\textrm}{m}$. Apressorium size was measured 6.3~8.5$\times$4.5~5.0 ${\mu}{\textrm}{m}$. The agents were identified as Colletotrichum truncatum and C. gloeosporioides based on their morphological characteristics. There was a large difference in pathogenicity between two isolates. C. gloeosporioides caused dark brownish discoloration of whole plants. It showed high pathogenicity with severe disease development. Meanwhile C. gloeosporiodes caused light brown spots on cotyledon and its pathogenicity was not strong. The soybean sprout rot occurred by the two Colletotrichum species was firstly reported in soy-bean sprout in Korea, and we suggest it as “Colletotrichum rot of soybean sprout”.

Chinese Cabbage and Radish Performance and Soil Chemical Properties Affected by Simulated Acid Rain (인공산성(人工酸性)비 처리량(處理量)에 따른 배추와 무의 생육(生育)과 토양(土壤) 화학성(化學性) 변화)

  • Lee, Suk-Soon;Kim, Bok-Jin;Hong, Seung-Beom;Park, Suen-Do
    • Korean Journal of Environmental Agriculture
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    • v.15 no.4
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    • pp.419-424
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    • 1996
  • A green house experiment was conducted to investigate the performance of Chinese cabbage and radish and changes in soil chemical properties after application of different amounts of simulated acid rain (SAR). About 10mm of normal water (pH 6.0), 5mm of SAR followed by 5mm of normal water, and 10mm of SAR were applied 24 times at the two-day intervals. The results obtained are summarized as follows : 1. Visible symptoms were dark brown, red brown, or grey brown leaf spots, reduced leaf size, or some times wrinked leaves in both crops. The visible symptoms started after the third application of SAR. The degree of damages was greater as the amounts and the number of times of SAR application increased. 2. Chlorophyll contents of SAR applied leaves decreased as the amounts of SAR application increased. 3. As the amounts of SAR increased, length, diameter, and fresh weight of Chinese cabbage heads and radish roots decreased. 4. In both crops sulfur content increased, while calcium content decreased as the amounts of SAR increased. Contents of N, P, K, and Mg were not significnatly affected by the amounts of SAR. 5. SAR decreased soil pH and exchangeable cations (Ca, Mg, K), while increased soil sulfur content.

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Pink Rot of Palms Caused by Gliocladium vermoseni (Gliocladium vermoeseni에 의한 야자 분홍썩음병(가칭))

  • Han, Kyung-Sook;Park, Jong-Han;Lee, Jung-Sup;Seo, Sang-Tae;Jang, Han-Ik
    • Research in Plant Disease
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    • v.10 no.4
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    • pp.345-348
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    • 2004
  • Pink rot of Palm was occurred at Yeuju area in 2001 and 2003. Infected plants showed rotting at the leaf-stock bases and killing of the terminal bud. The first symptoms are dark brown necrotic areas on the stem. Bases of infected frond may be covered with pink spores and the spots produced oozing gum pockets. Oozing lesions occur on the stems, and leaves turn brown and droop. The causal agent were isolated from salmon-pink spores sporulating on the leaf sheaths and necrotic stem tissues. Pathogen were isolated from freshly infected tissues were identified as Gliocladium vermoseni based on mycological characteristics. Fungus were grown plenty on PDA culture. Temperature for mycelial grown was tested at 5 to $40^{\circ}C$ and optimal temperature was $25^{\circ}C$ and was not nearly grew at temperature above $35^{\circ}C$. Artificial pathogenicity were tested on 9 species of Palm family in the wound inoculation and symptoms showed similar to those observed in the field. This is the first report on pink rot of palm in Korea.

A New Species of Skate (Chondrichthyes : Rajidae), Okamejei mengae from the South China Sea (남중국해산 홍어과 (연골어강, 홍어과) 어류 신종, Okamejei mengae sp. nov.)

  • Jeong, Choong-Hoon;Nakabo, Tetsuji;Wu, Han Ling
    • Korean Journal of Ichthyology
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    • v.19 no.1
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    • pp.57-65
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    • 2007
  • A new species of the rajid genus Okamejei is described from a single specimen (295 mm TL) from off Shantou, Gwangdong in the South China Sea. The new species differs from all other congeners in the following combination of characters: snout pointed, dorsal head length 6.7 times interorbital width, tail moderately wide and long, its length 48.5% TL, interdorsal distance less than length of first dorsal fin base, postdorsal tail short as 5.8% TL, small evenly distributed dark brownish spots, without ocelli on dorsal surface of disc, pores of ampullae of Lorenzini on ventral surface distributed from snout tip to distal end of metapterygium, scapulocoracoid high, its height about 1.4 times rear corner height, trunk vertebrae 23, predorsal tail vertebrae 50 and pectoral fin radials 96.

A Review on the Interpretative Guidelines on EU Air Transport Passenger Rights Regulations in the Context of the Developing Situation with COVID-19 (항공여객보상에 관한 EC 261/2004 규칙의 COVID-19 관련 해석지침 검토)

  • Sur, Ji-Min
    • The Korean Journal of Air & Space Law and Policy
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    • v.35 no.3
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    • pp.39-63
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    • 2020
  • This paper reviews the Interpretative Guidelines on EU passenger rights regulations in the context of the developing situation with COVID-19 of EU commission. To enlighten the obscurity and to mitigate the economic impacts of the COVID-19, European Commission has published "Interpretative Guidelines on EU passenger rights regulations in the context of the developing situation with Covid-19" on March 18, 2020. The Guideline essentially aims to create a coherent system of rules to assist the passengers, industry and national authorities overall under the unprecedented circumstances across the European Union. To do so, the Guideline is drafted to cover the rights of passengers travelling by air, rail, ship or bus/coach, maritime and inland waterways, as well as the corresponding obligations for carriers. From an aviation industry focused perspective, by referencing the Regulation (EC) numbered 261/2004, the Guideline specifically applies to cancellation and delay in flights which are seen as the dark spots for the air carriers concerning potential burdens.