• Journal of Ecology and Environment
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• 제30권1호
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• pp.97-99
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• 2007

Waders inhabiting an area in which A. tyosenense is endemic were examined to determine if they serve as reservoir hosts for the parasite. Of the waders examined, 4 individuals from 2 species were found to be hosts for 18 to 1820 adult worms. Common and velvet scoters, which are known to be the final hosts of A. tyosenense, are rare in the infected areas, while waders are prevalent and prey on the bivalves known to be intermediate hosts of A. tyosenense. Thus, from the experimental results and circumstances presented herein, we conclude that waders are definitive and reservoir hosts of A. tyosenense in nature.

• Parasites, Hosts and Diseases
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• 제32권4호
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• pp.277-280
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• 1994

폐흡충의 피낭유충이 종숙주에 도입되면 십이지장에서 탈낭하여 장벽을 통과하고. 복강과 흉강을 돌아다닌 후 8주일이면 성충으로 발육한다. 이 연구에서는 종숙주에서 발육중인 폐흡충 발육단계의 어느 시기까지 종숙주에 대한 감염력을 유지하는지를 관찰하였다. 가재에서 분리한 폐흡충 피낭유충을 고양이에 경구감염(경구감염) 시키고 3일 7일, 10일, 14일, 21일 및 28일 후 각 발육단계의 충페론 얻었다. 그리고 각 단계를 고양이에 다시 경구감염시킨 다음 1-12주일 후 고양이를 해부하여 감염 여부를 조사하였다. 종숙주에서 3일간 발육한 충체와 7일간 발육한 충체를 경구감염시킨 고양이에서 각각 투여 충체수의 31.4% 및 22.6%를 검출하였다. 종숙주에서 10일, 14일, 21일, 28일간 성장 발육한 충체를 경구감염시킨 고양이에서는 감염충체를 발견할 수 없었다. 이상의 결과 종숙주에서 최소한 7일간 발육한 폐흡충의 유충은 다시 종숙주를 감염시킬 수 있는 능력을 지니고 있었다.

• 한국수산과학회지
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• 제34권6호
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• pp.720-728
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• 2001

1999년 3월부터 2000년 3월까지 서해안 만경강 하구역의 심포리 지선 간석지에서 채집한 갯우렁이 (Lunatia fortuni)와 큰구슬우 렁이 (Neverita didyma)에서 Cercaria yamagutii Ito,1957를 검출하고, 실험실에서 이매패류인 동죽 (Mactra venerifomis)에 감염 시켜 피낭유충이 형성됨을 확인하였고, 동 실험에서 형성된 피낭 유충을 괭이갈매기 (Larus crassiostris)에 경구 감염시켜 10일 후 성충을 얻어 Acanthoparyphium tyosenense Yamaguti, 1939임을 확인하여 지금까지 밝혀지지 않았던 이 충의 전 생활사를 밝혀냈다. 제1중간숙주는 해산 복족류인 갯우렁이, 큰구슬우렁이, Tympanotonus microptera와 Cerithidea (Cerithidea) largillierti, Cerithidea (Cerideopsilloa) cingulata이고, 제 2중간숙주는 이매패인 동죽, 개량조개, 맛조개, 바지락이며, 종숙주는 괭이갈매기와 물오리의 일종인 Melaniua fusca stejnegeri이다. 갯우렁이와 큰구슬우렁에서 검출한 Cercaria yamagutii를 실온 $25^{\circ}C$ 전후에서 동죽이 들어있는 수조에 넣은 후 30분 이내에 입수는 피낭의 크기 $300\sim360{\mu}m$, 탈낭유충$790\sim800\times300\sim310{\mu}m$크기로 활발히 신축 운동하는 성숙한 유충으로 발육되었다. 자연산 이매패에서 Acanthopayphium tyosenense의 피낭유충 기생율은 동죽 $99.5\%$, 맛조개 $76.3\%$, 바지락 $37\%$이었고, 피낭유 충의 부위별 기생율은 동죽의 경우 검출된 피낭유충 총 18,064개중 족부 근육 $62.9\%$ (11,368개), 아가미 $23.6\%$ (4,258개), 내장낭$13.5\%$ (2,435개)의 기생율을 나타냈다. 피낭유충은 숙주 종이나 크기와 관계없이 나타났다.

• Parasites, Hosts and Diseases
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• 제39권3호
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• pp.209-221
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• 2001

Examination of the original descriptions of genera placed within the family Oposthorchiidae has revealed that only 33 of the original 43 genera are valid members of this family Further study of these descriptions should also reveal that many of the subfamilies are also invalid. With reference to the original descriptions of these genera, and subsequent literature, a brief survey of the family has been compiled. Information on the spectrum of definitive hosts that these helminths parasitize is provided, as well as information on the life cycles, geographic distribution, and socioeconomic impacts of the family. More in-depth information is given on those species that are of particular medical importance; namely, Clonorchis sinensis, Opisthorchis viverrini and O. felineus. The final aims of this review are to provide information on the entire genera of the family Opisthorchiidae, which will aid understanding of the phylogenetic relationships not only within the family, but also within the Class Trematoda.

• Parasites, Hosts and Diseases
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• 제46권4호
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• pp.229-234
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• 2008

The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area.

• 한국동물위생학회지
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• 제41권4호
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• pp.239-244
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• 2018

Mycobacterium tuberculosis (M. tuberculosis) complex is the causative agent of tuberculosis (TB) in humans and bovine TB in mammalian hosts and grows very slowly. Selenium is a central molecule in nitrogen metabolism and an essential ingredient for all living cells and glutamic acid. The effects of selenium on the growth of M. tuberculosis, a representative slow-growing Mycobacterium species, were investigated and measured using the BacT Alert 3D System (MB/BacT System). Sodium selenate, at a final concentration of $10{\mu}g/mL$, reduced the average time-to detection (TTD) to 197.2 hours (95% confidence interval (CI), 179.6~214.8) from 225.1 hours (95% CI, 218~232.0) in the control culture media (P<0.05). The TTD did not increase with $\text\tiny{L}$-glutamate concentrations up to $10{\mu}g/mL$, but a significant reduction in the TTD was observed in the presence of $20{\mu}g/mL$ ${\text\tiny{L}}$-glutamate in culture media (P<0.05). In conclusion, selenate and ${\text\tiny{L}}$-glutamate enhance the growth of M. tuberculosis.

• Journal of Information Processing Systems
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• 제18권1호
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• pp.75-88
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• 2022

With the development of the sharing economy, existing recommender services are changing from user-item recommendations to user-user recommendations. The most important consideration is that all users should have the best possible satisfaction. To achieve this outcome, the matching service adds information between users and items necessary for the existing recommender service and information between users, so higher-level data mining is required. To this end, this paper proposes a user-to-user matching service (UTU-MS) employing the prediction of mutual satisfaction based on learning. Users were divided into consumers and suppliers, and the properties considered for recommendations were set by filtering and weighting. Based on this process, we implemented a convolutional neural network (CNN)-deep neural network (DNN)-based model that can predict each supplier's satisfaction from the consumer perspective and each consumer's satisfaction from the supplier perspective. After deriving the final mutual satisfaction using the predicted satisfaction, a top recommendation list is recommended to all users. The proposed model was applied to match guests with hosts using Airbnb data, which is a representative sharing economy platform. The proposed model is meaningful in that it has been optimized for the sharing economy and recommendations that reflect user-specific priorities.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.651-656
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• 2013

Human schistosomiasis caused by Schistosoma japonicum and Schistosoma mekongi is a chronic and debilitating helminthic disease still prevalent in several countries of Asia. Due to morphological similarities of cercariae and eggs of these 2 species, microscopic differentiation is difficult. High resolution melting (HRM) real-time PCR is developed as an alternative tool for the detection and differentiation of these 2 species. A primer pair was designed for targeting the 18S ribosomal RNA gene to generate PCR products of 156 base pairs for both species. The melting points of S. japonicum and S. mekongi PCR products were $84.5{\pm}0.07^{\circ}C$ and $85.7{\pm}0.07^{\circ}C$, respectively. The method permits amplification from a single cercaria or an egg. The HRM real-time PCR is a rapid and simple tool for differentiation of S. japonicum and S. mekongi in the intermediate and final hosts.

• 한국작물학회지
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• 제45권1호
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• pp.59-70
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• 2000

In nature, plant diseases, insects and parasites (hereafter called as "pest") must be co-survived. The most common expression of co-survival of a host crop to the pest can be tolerance. With tolerance, chemical uses can be minimized and it protects environment and sustains host productivity and the minimum pest survival. Tolerance can be applicable in all living organisms including crop plants, lifestocks and even human beings. Tolerant system controls pest about 90 to 95% (this pest control system often be called as horizontal or partial resistance), while the use of chemicals or selection of high resistance controls pest 100% (the most expression of this control system is vertical resistance or true resistance). Controlling or eliminating the pests by either chemicals or vertical resistance create new problems in nature and destroy the co-survial balance of pest and host. Controlling pests through tolerance can only permit co-survive of pests and hosts. Tolerance is durable and environmentally-friend. Crop cultivars based on tolerance system are different from those developed by genetically modified organism (GMO) system. The former stabilizes genetic balance of a pest and a host crop in nature while the latter destabilizes the genetic balance due to 100% control. For three decades, the author has implemented the tolerance system in breeding maize cultivars against various pests in both tropical and temperate environments. Parasitic weed Striga species known as the greatest biological problem in agriculture has even been controlled through this system. The final effect of the tolerance can be an integrated genetic pest management (IGPM) without any chemical uses and it makes co-survival of pests in nature.in nature.

• Parasites, Hosts and Diseases
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• 제48권3호
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• pp.271-274
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• 2010

Adult worms of Parvatrema spp. (Digenea: Gymnophallidae) were found in the intestines of 2 species of migratory birds, i.e., a great knot, Calidris tenuirostris, and 2 Mongolian plovers, Charadrius mongolus, in the coastal area of Gunsan-si, Jeollabuk-do in October 2009. The recovered Parvatrema worms were 79 in total number and composed of 2 species. The worms from a great knot were $289{\mu}m$ in length with the oral and ventral sucker ratio of 2:1. They had a single vitellarium, and their intrauterine eggs were $25.0{\times}17.5{\mu}m$ in size. These findings were compatible with P. duboisi (Dollfus, 1923) Bartoli, 1974 (syn. P. timondavidi Bartoli, 1963). The worms recovered from the Mongolian plovers were smaller in length than P. duboisi and had 2 vitellaria. The oral and ventral sucker ratio was 2.5 : 1, and the eggs were $17.5{\times}8.8{\mu}m$ in size. These worms were assigned to be P. homoeotecnum James, 1964. This is the first report on the natural final hosts of Parvatrema spp. in Korea.