• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.9-17
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• 2020

Domestic cats (Felis catus) introduced to insular environments can be invasive predators that often threaten endemic species and cause biodiversity loss or local extinction on the island. This study was conducted from March to July 2018 to understand the population size, home range, and spatial use of cats introduced to Mara Islet (N 33° 07', E 126° 16') in Jeju Special Governing Province, the Republic of Korea. Observation records based on their natural marks revealed that there were 20 adult cats on Mara Islet. A capture-recapture method also estimated 20 adult individuals (95% confidence interval: 20-24 individuals). According to our telemetry study on ten adults deployed with GPS-based telemetry units, the home range size was 12.05±6.99 ha (95% KDE: kernel density estimation), and the core habitat size was 1.60±0.77 ha (50% KDE). There were no significant differences in the home range and core habitat sizes by sex. The home range of domestic cats overlapped with the human residential area, where they might secure easy foods. Five of ten tracked cats were active at potential breeding colonies for the Crested Murrlet (Synthliboramphus wumizusume), and six approached potential breeding areas of the Styan's Grasshopper Warbler (Locustella pleskei), suggesting the predation risk of the two endangered species by cats. This study provides novel information on the population size and home range of introduced cats on Mara Islet which is an important stopover site of migratory birds as well as a breeding habitat of the two endangered avian species. Reducing the potential negative impacts of the introduced cats on migratory birds and the endangered species on Mara Islet requires monitoring of the predation rate of birds by cats, the population trends of cats and endangered breeding birds as well as the effective cat population control and management.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.7-11
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• 1983

The purpose of this study was to prepare low methoxyl pectins (LMPs) by pectinesterase (PE) using waste tangerine peels and to compare the chemical, physical and gelling properties of the prepared pectins with the commercial LMP. The LMPs were prepared by treating albedo with 0.25M $Na_2CO_3$ to activate the PE. PE was then inactivated by heating. The sample was centrifuged and the supernatant was collected. LMP was obtained as precipitate by adding alcohol to the collected supernatant. The amounts of extractible pectins in albedo were 12.71~12.98% on a dry weight basis. Methoxyl contents of LMPs prepared by treating albedo with PE at pH 7.5 for 10min, at pH 8.5 for 10min, 20min and 30min were 5.12%, 4.27%, 3.08%, 1.85% respectively, demonstrating that the methoxyl contents of the preparations decreased as the degree of treatment albedo with PE increased. The acetyl contents of the preparations ranged from 0.09% to 0.12%, the values of which do not interfere with gel formation. The anhydrouronic acid contents of the prepared pectins were in the range of 94.2%~94.8%. The values of viscosity and molecular weights of the prepared LMPs tent to decrease as the degree of PE action on albedo increased. The textural value of the prepared LMP gels determined by Consistometer, Ridgelimeter and Instron denonstrated that the excess treatment of albedo with PE significantly impaired the gelling properties of the preparations.

• Journal of Life Science
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• v.9 no.2
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• pp.121-126
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• 1999

Some attempts were made to investigate the honeydew excretion of the brown planthopper(BPH), Nilaparvata lugens Stal, biotypes in terms of instal nymph, days after emergence, macropterous and brachypterous mated and unmated female, and macropterous female with different sources fed on 60-day-old rice cultivars with different resistance genes. The feeding amount of the BPH biotypes was measured by using the honeydew excretion test. The feeding amount of fifth instar on Miryang 23 with no resistance gene was higher than that of Cheon-gcheongbyeo with Bph-1 gene by two times. Macropterous and brachypterous females showed low feeding amount at first day after emergence, but they showed high feeding amount from second days after emergence. Also the feeding amount of brachypterous female was higher than that of macropterous female. In addition, the feeding amount of BPH was in the order of nymph

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.64-70
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• 2013

The greenhouse whitefly, Trialeurodes vaporariorum, is an economically important pest for greenhouse crops because they cause direct damage by feeding on plant nutrients and indirect damage as transmits many virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among greenhouse whitefly population. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of nymph greenhouse whitefly were investigated. Isolated fungus was identified as Isaria fumosorosea by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin, and EF1-${\alpha}$ regions. This fungus was named as I. fumosorosea SDTv and tested for the virulence against nymphs T. vaporariorum and the cold activity, the thermotolerance and the stability of UV-B irradiation on conidia. Mortality rate of greenhouse whitefly showed from 84 to 100% and the virulence increased with increasing conidial concentrations, $1{\times}10^5$ to $10^8$ conidia/ml. Conidia were stable at $35^{\circ}C$, 0.1 $J/cm^2$ of UV irradiation and germinated after 8 days at $4^{\circ}C$. Additionally, the activities of chitinases and proteases produced by I. fumosorosea SDTv were varied according to the medium. In conclusion, I. fumosorosea SDTv which showed high mortality rate against greenhouse whitefly will be used effectively in the integrated pest management programs against the greenhouse whitefly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.182-187
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• 2009

Physicochemical and organoleptic characteristics of omija wines made by traditional method, adding grape juice and sugar solution periodically, and with dry omija were compared. The pH values of all omija wines were ranged $2{\sim}3$ during fermentation. The acidity value of omija wine made by traditional method was 2.5%, that of omija wine made by adding grape juice and sugar solution periodically decreased from 3.3% to 0.8%, and that of omija wine made with dry omija increased from 0.2% to 3.9%. Sucrose and alcohol contents were $6.5{\sim}34.5^{\circ}Brix$ and 12% at the end of fermentation, respectively. The viable cell numbers of yeast decreased from $5.7{\sim}6.9\;\log\;CFU/mL$ to $4.3{\sim}4.6\;\log\;CFU/mL$. Omija wine made by adding grape juice and sugar solution periodically had the highest sensory scores for color, taste, flavor, swallowing, and overall acceptability, and was significantly different from the both omija wines made by traditional method and with dry omija. Because omija is rarely fermented due to the little fermentative sugar content, omija wine made by adding grape juice and sugar solution periodically was shown to be the most appropriate.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.11-19
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• 2009

This study was performed to investigate the seasonal occurrence, developmental characteristics of each nymphal stages with different temperatures (20, 25, $30^{\circ}C$), longevity and fecundity of ussur brown katydid, Paratlanticus ussuriensis, damaging by outbreaks in the orchard areas of Bitan-ri, Yeongdong, Chungbuk. Paratlanticus ussuriensis occurred from late-March to late-August with peak of mid-May. Newly emerged nymphs appeared from March and do damaged fruit orchards with peak of mid-May when P. ussuriensis existed as 4th and 5th nymphal stages. P. ussuriensis adult occurred from early-June to mid-Aug. with peak of mid-July. Total density of P. ussuriensis was showed highest in mid-May. Paratlanticus ussuriensis goes through nymphal stages to 7th nymph, the ovipositor began exposed to outside from the 4th instar and the body weight increased heavily from this stage and the wings were observed from 6th instar. Developmental period was longer as increased the nymphal stages. Sex ratio of collected insect was showed as 0.57; females more than males. As increased the temperature, developmental period was to be short. Preoviposition was also to be short as 5.0, 4.3, and 3.4 days at 20, 25, $30^{\circ}C$, respectively, and fecundity increased as 69.0, 87.1, and 104.3 at 20, 25, $30^{\circ}C$, respectively. Longevity of male and female at $25^{\circ}C$ was showed the longest with 35.7, and 32.9 days and showed the shortest with 30.1 and 28.1 days at $30^{\circ}C$, respectively. The difference of developmental period in male and female were showed longer in female without relation of temperature. The eggs laid were frequently distributed 3 to 4 cm from soil surface, and showed the behavior laying eggs intensively when early oviposition period.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.9 no.2
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• pp.138-147
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• 1998

Authors surveyed intrafamilial child sexual abuse in the children under 15years old in clinical. We sent the semi-structured child sexual abuse questionnaires to 7055 board certified pediatrics, obstetrics and gynecology, family medicine and emergency medicine. Total respondents were 1205. The results from these respondents were as follows. 1) The numbers of respondents who have had the experience of treating victims of intrafamilial child sexual abuses were 157(13.0% of total respondents). 2) Among the perpetrators, 58(36.9%) were siblings and 32(20.4%) 26(16.6%) were step-fathers, and respectively. The most common age bracket was 10s(39.5%), and the next was 40s and 50s (33.7%) Almost all(98.7%) of the perpetrators were male. 3) The mean age of victims was $12.1{\pm}3.3$ years old, and all of the victims were female, and the number of victims who had previous mental or physical handicaps and behavior problems were 5(3.2%) and 8(5.1%) respectively. 4) The ways by which intrafamilial child sexual abuses were found were abnormal behaviors 45(28.7%), victim's own report 40(25.5%), pregnancy 18(11.5%), pain complaint 13(8.3%), other person's report 13(8.3%), and detection during examination 12(7.6%). 5) Time lags between intrafamilial child sexual abuses and hospital visits were after 1 month 97(61.8%), from 1 day to 1 week 29(18.5%), within 1 day 21(13.4%), and from 1 week to 1 month 10(6.4%). 6) Physical complications were perineal wound 93(59.2%), hymen rupture 90(57.3%), pregnancy 68(43.3%), wound of other part of body 11(7.0%), and sexually transmitted disease 4(4.5%). 7) Treatment for victims were discharge 92(58.6%), admission, operation or transfer to a bigger hospital 25(15.9%), psychiatry consult 19(12.1%), report to police(10.9%) and social work consult 3(1.9%). These results suggest that considerable numbers of physicians have had the experience of treating victims of intrafamilial child sexual abuses, and intrafamilial child sexual abuses are the major medical as well as social issue in children in Korea.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.411-417
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• 2009

This research is intended to discover physiological and biochemical defense mechanisms against herbivores of 8 species of the genus Acerby examining the morphological characteristics of the leaf, the structure and number of leaf domatia, herbivores insects and mites feeding on leaves, which were collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Mt. Bangtae, Mt. Taebaek and Wonju City. This research was conducted from May through July, 2009, and the results are as follows. The domatia of A. pseudosieboldianum, A. pictum subsp. mono and A. mandshuricum belongs to tuft type; that of A. palmatum, A. triflorum and A. tschonoskii pocket+tuft type; and that of A. tegmentosum pocket type. The number of domatia per leaf turned out to be the highest in the case of A. tegmentosum(20.2), and the lowest in the case of A. ginnala (4.2). Leaf surface trichomes of A. palmatum, A. pseudosiebotdianum, A. ginnala and A. mandshuricum are covered with villi; those of A. pictum subsp. mono and A. triflorum with soft, pilose type of hair, and those of A. tschonoskii with stiff, strigose hair. The trichome density of lower leaf surface is found to be higher than that of the upper leaf surface. Only in the case of A. palmatum, A. pseudosieboldianum, A. tegmentosum and A. tschonoskii, a small amount of nectar is found to be secreted from the distal vein parts of the leaf margin. The number of mites on each leaf are found to be significantly different among tree species, and average mites number per leaf was the highest in the case of A. tschonoskii (9.2/leaf), and A. mandshuricum, A. pseudosieboldianum, and A. triflorum follow it in decreasing order. Minute insects attacking the leaf of Acer spp. include Periphyllus californiensis, P. viridis, Psylla spp, and gall mites, and the number of these insects are found in Periphyllus californiensis, Psylla spp, P. viridis, and Cicadellidae sp. in decreasing order. The natural enemies of these herbivores insects are predatory mites, such as Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi, Poecilocoris lewisi and its larva, and Poecilocoris lewisi. Lasius japonicus and Formica japonica are symbiotic with aphids, and supports herbivores. Finally, our research confirmed that predatory mites attack Periphyllus californiensis and suck the body fluid of their victim. This proves that mites form a symbiotic relationship with plants through the mediation of leaf domatia. This also indicates that a protective mutualism may be more conspicuous in temperate broad-leaved trees.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.39-45
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• 2012

To explore on the defense strategies against hervivory of 67 broadleaved tree species, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Taean-gun, Chuncheongnam-do were investigated. 46 broadleaved tree species(68.7%) had the domatia structures, and 21 species including Quercus salicina and Magnolia grandiflora did not. 31 species including Juglans mandshurica and Carpinus laxiflora reveals tuft type, 12 species including Quercus dentata and Corylus heterophylla reveals pocket+tuft type, and 2 species, Sorbus alnifolia and Prunus yedoensis does pocket type, and Viburnum odoratissimum var. awabuki does pouch type. Domatia number per leaf proves the highest figures, 23.4/leaf for Quercus dentata. Plant defense strategies using leaf lower-surface trichomes of Magnolia grandiflora reveals dense villous, those of Populus alba and Vitis vinifera reveals dense pilose, that of Elaeagnus umbellata does dense scaly hairs, that of Pueraria lobata does dense strigose. Plant defense strategies using extrafloral nectaries were adapted 23 tree species(34.3%). Observed examples are Prunus tomentosa, Ficus carica, Viburnum dilatatum and Carpinus laxiflora. Predatory mites were observed on the leaves of 40 tree species(59.7%), and mean values of predatory mites was highest values 23.4/leaf in Quercus dentata. Minute arthropods destroying the leaf of broadleaved trees. are such as Periphyllus californiensis, P. viridis, Diaspididae sp., gall mites, thrips, and total numbers observed were odered gall mites, Diaspididae sp., aphids and thrips. Natural enemies of these hervivores arthropods are such as predatory mites, Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi. These results indicate that defense strategies including protective mutualisms may be frequent in the temperate broadleave trees.

• Korean Journal of Heritage: History & Science
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• v.54 no.2
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• pp.194-215
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• 2021

Termites are important decomposers in the ecosystem. They are also economically significant structural pests. In this study, we reviewed the developments of termite control and recent research on termite management to provide information on the prevention and control of termites. In Korea, most of the damage to wooden historical buildings is caused by subterranean termites. Reticulitermes speratus kyushuensis is the main species, which is widely found throughout the country. In the early 1900s, inorganic insecticides, such as arsenic dust, were used for termite control. After the synthesis of chlorinated hydrocarbon pesticide in the 1940s, it was widely utilized and demonstrated high termite control efficacy. However, chlorinated hydrocarbon insecticides were later banned, disappearing from markets after reports emerged concerning environmental contamination and toxicity to humans. Therefore, the termite control industry sought a new termiticide; hence many pesticides were utilized for termite control. Organophosphate (1960s), carbamate (1970s), pyrethroid, and insect growth inhibitor (1980s) were newly synthesized and adopted. In the 1990s, the first commercial baits using chitin synthesis inhibitors (CSI) were developed, providing a means to eliminate an entire colony of subterranean termites around a structure. Many studies have been carried out on soil termiticides (liquid termiticides) and CSI baits to increase their efficacy, and different baits such as aboveground bait stations, fluid bait, and high-durability bait were also developed in the 2000s. In addition, the paradigm of termite control has shifted from localized treatments using soil termiticides to area-wide pest management using CSI baits to create termite-free zones and protect buildings over time. Termite infestations in wooden historical buildings in Korea have been reported since 1980, and considerable attention was drawn in the 1990s when several UNESCO world heritages such as the Jongmyo Shrine and the Janggyeong Panjeon Depositories of Haeinsa Temple were infested by subterranean termites. Since then, a survey of termite infestation in wooden architectural heritage has been conducted, and the National Research Institute of Cultural Heritage and Heritage Care Program regularly monitors those properties. Finally, we suggest termite management using primarily CSI baits, selective application of various soil treatments applied to the object, foundation soil treatment, research and development of durable termite baits, application of area-wide programs for wooden-building complexes, application of integrated termite management (ITM), and regular education for owners and managers to prevent and reduce termite damage.