• Journal of Ecology and Environment
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• v.30 no.1
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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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• v.32 no.4
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• pp.277-280
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• 1994

In the definitive hosts, metacercariae of Parofonimn westermani excyst in host duodenum, penetrate intestinal wall, migrate peritoneal and thoracic cavities, and develop to sexual maturity in 8 weeks. This study was undertaken to examine the age of the maturing p. westernnni when their infectivity to the other definitive hosts was retained. On 3, 7, 10, 14,21 and 28 days after feeding the metacercariae to cats through a gastric tube, the developing worms were harvested. The juveniles of different age were fed again to other experimental cats. One to 12 weeks after the oral-transfer infections, the experimental cats were examined for establishment of infections. In the cats to which 3- day and 7-day old juveniles (grown up to 1.4 mm long) were fed, 31.4% and 22.6% of the transferred worms were found infected. The worms of 10-28 days old were not infective. Early maturing stages grown up to 7 days maintained their infectivity to the other definitive hosts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.720-728
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• 2001

Cercaria yamagutii Ito, 1957 (C. yamagutii) was found in Lunatia fortuni (L. fortuni) and Neverita didyma (N. didyma) collected from the tideland of Sim-po located at the estuary of the Mankyong River, Chonbuk. It was finally confirmed that the parasite is Acanthoparyphium tyosenense Yamaguti, 1939 (A. tyosenense) and its life history was clarified in this study. Mactra veneriformis (M. veneriformis) was artificially infected with C. yamagutii isolated from L. fortuni and N. didyma. It began to intrude into M. veneriformis through the inhalent canal. Five hours after infection, the tails of the cercaria began to be separated from the main body and the cercaria started to form cysts. Mature cysts were formed 340 hours (14 days) after infection. The cysts were $300\sim360{\mu}m$ in diameter and the encysted metacercarias were $790\sim800\times300\sim310{\mu}m$ in size. The metacercarias were administered orally to Larus crassiostris (L. crassiostris), and adult worms of $84.5\sim112.5\times55\sim65{\mu}m$ were found full of eggs with $2.20\~3.70$ mm long and $0.40\~0.59$ mm wide after 10 days. In a field study, it was observed that the infection rate of A. tyosenense is $99.5\%$ in M. venerifomis, $76.3\%$ Solen strictus (S. strictus), and $37\%$ Ruditapes philippinarum (R. philippinarum), No difference was found among different host sizes, It was concluded that the first intermediate hosts of A. tyosenense Yamaguti were L. fortuni, N. didyma, Tympanotonus microptera, Cerithidea (Cerithidea) largillierti, Cerithidea (Cerideopsilloa) cingulata, the second intermediate hosts M. venerifomis, S. strictus and R. philippinamn, and the final hosts L. crassiostris and Melanitta fusca stejnegeri.

• Parasites, Hosts and Diseases
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• v.39 no.3
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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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• v.46 no.4
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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.

• Korean Journal of Veterinary Service
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• v.41 no.4
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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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• v.18 no.1
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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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• v.51 no.6
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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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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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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• v.48 no.3
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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.