• Korean journal of applied entomology
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• v.42 no.2
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• pp.125-132
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• 2003

Seasonal fluctuations in density of mosquito species were investigated at two cow sheds near to a large, reedy marsh with fairly polluted brackish water near the coast of Yongam-ri, Cheongryang-myon, Ulsan, Korea. Female mosquitoes were collected biweekly using Nozawa light traps from March to September, from 1999 to 2001. On average, 4,416.1, 5,505.9 and 6,863.8 females per trap night were collected from 10 species in 5 genera in 1999, 2000 and 2001, respectively. Among them, An. sinensis was most abundant (53.4% in species ratio), followed by Cx. tritaeniorhynchus (43.0%), Cx. inatomii (1.6%), Ochlerotatus dorsalis (1.3%) and Cx. pipiens pallens (0.5%). A malaria vector, An. sinensis and a Japanese encephalitis vector, Cx. tritaeniorhynchus were collected 3,663.3 females and 3,142.5 females per trap night from June to September for the years, respectively. According to the biweekly population changes at the area, Cx. inatomii which was dominant species in 1997, was the most abundant in the early July during 1999-2001.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.37-44
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• 1991

A shuttle promoter-probe vector, pEB203, was derived from pBR322, pPL703 and pUB110. Using the vector, a useful DNA fragment, 319 bp EcoRI fragment, having strong promoter activity has been cloned from Bacillus subtills chromosomal DNA. Selection was based on chloramphenicol resistance which is dependent upon the introduction of DNA fragments allowing expression of a chloramphenicol acetyl transferase gene. The nucleotide sequence of the 319 bp fragment has been determined and the putative -35 and -10 region, ribosome binding site, and ATG initiation codon were observed. This promoter was named EB promoter and the resultant plasmid which can be used as an expression vector was named pEBP313. The crystal protein gene from B. thuringiensis subsp. kurstaki HD-73 was cloned downstream from the EB promoter without its own promoter. When the resultant plasmid, pBT313, was introduced into Escherichia coli and B. subtilis, efficient synthesis of crystal protein was observed in both cells, and the cp gene expression in B. subtilis begins early in the vegetative phase. The cell extracts from both clones were toxic to Hyphantria cunea larvae.

• Korean Journal of Veterinary Service
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• v.41 no.4
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• pp.287-289
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• 2018

This study was conducted to investigate the detection of various vector-borne pathogens in such cats. A total of 48 stray cats collected in Daejeon were included in this study. The total positive rate of hemotropic mycoplasmas and Babesia spp. was 25% and 4%, respectively. It is recommended that species-level classification of hemotropic mycoplasmas and Babesia spp. is needed and that a large-scale prevalence study of infectious agents in all the regions of South Korea be conducted.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.381-392
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• 2018

The distribution of mosquitoes collected in the Cheongju area from 2016-2018 were compared. The collection sites were established at a residential area, migratory bird sanctuary, and cowshed using black light (BL) and BG sentinel traps. Culex pipiens was the most collected species in the residential area, and Aedes vexans was the most collected species in the migratory bird sanctuary and cowshed in all years. The BG trap collected more individuals than did the BL trap in the residential area and migratory bird sanctuary. In total, 22,679 (10 species) mosquitoes were collected in 2016, and 6,502 (8 species) and 6,803 (9 species) mosquitoes were collected in 2017 and 2018, accounting for 3.49- and 3.33-fold decreases, respectively. The relationship between meteorological conditions and mosquito density, according to various variables, was not significant different. The Chaoyang virus was found in Aedes vexans and Culex pipiens collected at the cowshed in 2016 and 2018, respectively. Based on the results of this study, it is considered that continuous surveillance of mosquitoes should be performed for controlling mosquito populations and mediating diseases spread by this vector.

• The Korean Journal of Zoology
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• v.2 no.1
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• pp.17-28
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• 1959

In Korea ,little attention was paid to chiggers until 1950 so only to reports on four species of chiggers were pulished before Korean War. Since 1950 (beginning of Korean War), a marked progress in the study of chiggers has been made in connection with investigations of Epidemic hemorrhagic fever occurring among the United Nations troops which was suspected as a chigger-borne infectious disease and the first report of tsutsugamushi disease in Korea called natives attention to chiggers as the vector mites of this newly known disease in Korea. This paper is mostly based on specimens of author's collections from 3269 Rodentia Insectivora, 9 Chiroptera, 24 Aves , 35 Amphibia and 3 Reptilia during the time from December 1955 to December 1956 but four species were introduced here from works of others . There are reported here five species of chiggers previously known only out of Korea and a new species also. This new species was collected by author but Lipovsky informed his colleague had collected the same one in Korea and they would publish it as new one in near future. This is the reason of describing the new species without specific name . Of course, this paper is incomplete in view of the geographic distribution, seosonal change and host relation etc, but will serve as a brief summary of the chiggers fauna of Korea up to the present. This species described here are as follows : Gahrliepia brennani var. ventralis Neoschongastia posekanyi Euschongastia kigtajimai Euschongastia miyagawai Euschongastia koreaensis Trombicula nagayoi Trombicula japonica Trombicula pomeranzevi Trombicula mitamurai Trombicula tamiyai Trombicula palpalis Trombicula orientalis Trombicula pallida Trombicula scutellaris Trobmicula miotis Trombicula hiranumai Trombicula sp. Trombicula hiranumai Trombicula sp. Trombicula subintermedius Shunsennia tarsalis . Euschongastia ikaoensis . Trombicula koomori Trombicul subakanushi

• Journal of Multimedia Information System
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• v.6 no.2
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• pp.49-60
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• 2019

Plants are very crucial for life on Earth. There is a wide variety of plant species available, and the number is increasing every year. Species knowledge is a necessity of various groups of society like foresters, farmers, environmentalists, educators for different work areas. This makes species identification an interdisciplinary interest. This, however, requires expert knowledge and becomes a tedious and challenging task for the non-experts who have very little or no knowledge of the typical botanical terms. However, the advancements in the fields of machine learning and computer vision can help make this task comparatively easier. There is still not a system so developed that can identify all the plant species, but some efforts have been made. In this study, we also have made such an attempt. Plant identification usually involves four steps, i.e. image acquisition, pre-processing, feature extraction, and classification. In this study, images from Swedish leaf dataset have been used, which contains 1,125 images of 15 different species. This is followed by pre-processing using Gaussian filtering mechanism and then texture and color features have been extracted. Finally, classification has been done using Multiclass-support vector machine, which achieved accuracy of nearly 93.26%, which we aim to enhance further.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1503-1509
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• 2014

With the purpose of facilitating the process of stable strain generation, a shuttle vector for integration of genes via a double recombination event into two ectopic sites on the Sulfolobus acidocaldarius chromosome was constructed. The novel chromosomal integration and expression vector pINEX contains a pyrE gene from S. solfataricus P2 ($pyrE_{sso}$) as an auxotrophic selection marker, a multiple cloning site with histidine tag, the internal sequences of malE and malG for homologous recombination, and the entire region of pGEM-T vector, except for the multiple cloning region, for propagation in E. coli. For stable expression of the target gene, an ${\alpha}$-glucosidase-producing strain of S. acidocaldarius was generated employing this vector. The malA gene (saci_1160) encoding an ${\alpha}$-glucosidase from S. acidocaldarius fused with the glutamate dehydrogenase ($gdhA_{saci}$) promoter and leader sequence was ligated to pINEX to generate pINEX_malA. Using the "pop-in" and "pop-out" method, the malA gene was inserted into the genome of MR31 and correct insertion was verified by colony PCR and sequencing. This strain was grown in YT medium without uracil and purified by His-tag affinity chromatography. The ${\alpha}$-glucosidase activity was confirmed by the hydrolysis of $pNP{\alpha}G$. The pINEX vector should be applicable in delineating gene functions in this organism.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.27-36
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• 1995

Comparative epidemiological studies on vector reservoir animals of tsutsugamushi disease were carried out in between south coast (the highest endemic) areas and east coast flow endemicl areas in October 1993. Fauna of field rodents and their population densities were not different between two areas. Antibody positive rate of Apodemus agrarius sera was higher in east coast (43.2% in south coast and 63.6% in east coast). High correlation (r = 0.87) was shown between antibody positive rate of A. osrwiur sera and population density of the vector mites (Leptotrombidium scutellare and 1. pnllidunl). L. scutellare was predominant in south coast, showing 110.6 chigger index (74.9% of the total chiggersl , whereas L. pcllidum was predominant in east coast, showing 126.3 chigger index (60.4% of the total). As higher population density of 1. scutellare was found in south coast where the prevalence rate of tsutsugamushi disease is the highest, it is believed that L. scutellare is more important vector species than L. pallidum which may result from more frequent vector-human contact.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.4
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• pp.259-275
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• 2021

This study explored the usefulness and implications of the Bayesian hyperparameter optimization in developing species distribution models (SDMs). A variety of machine learning (ML) algorithms, namely, support vector machine (SVM), random forest (RF), boosted regression tree (BRT), XGBoost (XGB), and Multilayer perceptron (MLP) were used for predicting the occurrence of four benthic macroinvertebrate species. The Bayesian optimization method successfully tuned model hyperparameters, with all ML models resulting an area under the curve (AUC) > 0.7. Also, hyperparameter search ranges that generally clustered around the optimal values suggest the efficiency of the Bayesian optimization in finding optimal sets of hyperparameters. Tree based ensemble algorithms (BRT, RF, and XGB) tended to show higher performances than SVM and MLP. Important hyperparameters and optimal values differed by species and ML model, indicating the necessity of hyperparameter tuning for improving individual model performances. The optimization results demonstrate that for all macroinvertebrate species SVM and RF required fewer numbers of trials until obtaining optimal hyperparameter sets, leading to reduced computational cost compared to other ML algorithms. The results of this study suggest that the Bayesian optimization is an efficient method for hyperparameter optimization of machine learning algorithms.

• Mycobiology
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• v.45 no.3
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• pp.160-171
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• 2017

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.