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        검색결과 146

        61.
        2014.04 구독 인증기관·개인회원 무료
        The Riptortus-Burkholderia symbiosis is a newly emerging insect-bacterium symbiotic system. This symbiosis system has a good merit as an experimental model system to produce the non-symbiotic (apo) and symbiotic (sym) host insect. In recent reported papers, the symbionts play important biological roles for the host insects. Meanwhile, juvenile hormone (JH) is one of major hormone synthesized corpora allata(CA) to control many physiology of insect. However, the study for cross-talk mechanism between symbionts and host hormones to control important physiological phenomenon of insects is almost none. In this study, we found that Riptortus speed up adult emerging and increase egg laying on presence of symbiont Burkholderia. Also we found that hexamerin proteins, which were controlled the expression by JH, were accumulated in sym-Riptortus hemolymph compare with apo-Riptortus. According as combined results, we hypothesized that the gut symbiont Burkholderia can control JH titer to conclude out beneficial effects such as development and reproduction of R. pedestris. To verify this hypothesis, we examined measurement of JH titer, expression of hexamerins as JH response genes and RNAi for hexamerin protein during whole Riptortus life on presence or absence of symbiont Burkholderia. All results demonstrated that gut symbiont controlled JH titer of Riptortus. Controlled JH amount by symbiont Burkholderia in host midgut regulated hexamerin protein expression for speeding up adult emerging and increasing egg production.
        62.
        2014.04 구독 인증기관·개인회원 무료
        Beet armyworm, Spodoptera exigua is difficult to control using chemical insecticides because of the development of insecticide resistance. Various control agents may use for eco-friendly beet armyworm managements, Entomopathogenic fungus is one of the promising control agents as an alternative to chemical control agent. At previous study we isolated a number of entomopathogenic fungi from soil samples and selected three entomopathogenic fungi, Metarhizium anisopliae FT83, Paecilomyces fumosoroseus FG340 and Metarhizium anisopliae FG344 which had high virulence against larva of beet armyworm. To select an isolate having high virulence at high temperature against S. exigua, thermophilic pest, we conducted bioassay at five different temperatures(15, 20, 25, 30, 35℃). These three isolates showed the high mortality and low LT50 at 30℃. To select substrate for mass production these isolates were inoculated(5×10⁴/㎖, 20㎖) at barley, unpolished rice, wheat bran and rice bran and incubated for 14 days at 25℃. Wheat bran showed highest conidia production of M. anisopliae FT83 and P. funosoroseus FG340 and barley was suitable for M. anisopliae FG344.
        63.
        2014.04 구독 인증기관·개인회원 무료
        Various insect pests infest crops including vegetables and ornamentals during crop production. Chemical pesticides have generally used until recently to control pests. Many pests are very difficult to control using organic pesticides because of the development of insecticide resistance and their rapid population increase. Entomopathogens are the promising alternative control methods. Entomopathogenic fungi are good candidates to control sucking insects such as aphid, whitefly and mite because the fungi can infect without ingestion. Conidia or blastospores of fungal entomopathogens are sprayed onto target plant and/or insect, adhered on insect surfaces, and penetrated into hemocoel through insect cuticle. Then the fungus utilize insect nutrients and kill the host insect. During this process, fungus was influenced by environmental conditions such as temperature, relative humidity and UV light. These are causing slow mortality and preventing wider application and use of mycopescitide using entomopathogenic fungi. In addition, control efficacy with fungal entomopathogen differed fungal isolate and host insect. Therefore, we need to study selection of high virulence isolate, mass production, formulation and application techniques to develop mycopesticide.
        64.
        2013.10 구독 인증기관·개인회원 무료
        Beet armyworm, Spodoptera exigua are difficult to control using chemical insecticides because of the development of insecticide resistance. For eco-friendly beet armyworm managements, various control agents are required. Entomopathogenic fungus is one of promise control agents as an alternative to chemical control agent. We isolated entomopathogenic fungi from soil samples of suwon by insect-bait method using Galleria mellonella and conducted bioassay to larva of beet armyworm. As a result of bioassay isolate FG274, FG340, FG344 had high virulence as 100% against second instar larva of S. exigua. To identify the fungus isolates, their’s morphological characteristic was observed and ITS of 18srRNA was sequenced. ITS sequence of FT274, 340, 344 were highly matched (100%) to that of Beauveria bassiana, Paecilomyces fumosoroseus, Metarhizium anisopliae. To investigate the optimal concentration, three isolates were sprayed at three different concentration(1×106 ,107 and 108 conidia/㎖) in laboratory conditions. 나타내었다.
        65.
        2013.10 구독 인증기관·개인회원 무료
        Use of conidia or spores of entomopathogenic fungi are influenced by environmental conditions such as temperature and relative humidity and caused slow and fluctuation of mortality. In addition, although the fungi have the advantage of a restricted host range, this specificity is one of the limiting factors for their use. These factors are preventing wider application and use of these biocontrol agents. To mitigate such problems we selected an Beauveria bassiana Bb08 which kill green peach aphid with its liquid culture filtrate. In this study we conducted bioassay with the fungal culture filtrate and culture fluid to greenhouse pests such as cotton aphid, whitefly and thrips. Culture fluid showed high mortality against green peach aphid, as well as cotton aphid, sweet potato whitefly, and western flower thrips. However, control effect of culture filtrate varied with pests. Culture filtrate showed high mortality to cotton aphid. Mortality of western flower thrips with culture filtrate was slower than culture fluid including spores and sweet potato whitefly was much lower. These results indicated that the culture fluid of Beauveria bassiana Bb08 has potential to simultaneously control various greenhouse pests.
        67.
        2013.04 구독 인증기관·개인회원 무료
        Bemisia tabaci, sweetpotato whitefly, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We conducted a study of the influence of relative humidity, temperature and different developmental stages on the susceptibility of sweetpotato whitefly to conidia of Isaria javanica isolate, which had been reported high virulence against Q biotype of B. tabaci. The mortality of tobacco whitefly was low at low constant relative humidities, but was high when kept high humidity for first 24 hours and transferred to low humidity. The Isaria isolate had wide range of temperature (15℃ to 35℃) to control sweetpotato whitefly. The isolate has virulence to the egg and all developmental stages of nymph of B. tabaci. These results indicated that the isolate had good control effects at various environmental conditions and is an excellent candidate to develop a microbial pesticide to control sweetpotato whitefly.
        68.
        2013.04 구독 인증기관·개인회원 무료
        Sweetpotato whitefly (Bemisia tabaci), especially Q biotype, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the conidia production of entomopathogenic fungus Isaria javanica Pf04, which had been reported high virulence isolate against Q biotype of B. tabaci, using grain. Brown rice was most suitable for conidia mass production of the isolate of I. javanica. Conidia was produced high at 25 ~ 27.5℃. The isolate produced more spores when conidia suspension directly inoculated onto media than two-phase fermentation. When concentration of inoculum was high spore production was high, but increasing rate of conidia production was highest at low inoculum concentration (1×105 conidia/ml) as 6,700 times increase compared with 20 times increase at high inoculum concentration (1×108 conidia/ml). These results indicated that the isolate can produce more conidia with cheap agricultural product and can develop as a microbial pesticide to control sweetpotato whitefly.
        69.
        2013.04 구독 인증기관·개인회원 무료
        The physiology of parasitic wasp control of their lepidopteran hosts' not only includes injecting their egg but also various factors such as symbiotic virus. This study was focused on the investigation of sophisticated interaction between parasitoid (Diadegma fenestrale) and their host (Plutella xylostella) in P. xylostella larva at transcriptome level, to check whether it is parasitized or not. Short-read deep sequencing method (Hiseq2000) was used for the transcriptome analysis. De novo assembly of cDNA sequence data generated 196,081 contigs between 201bp and 15,853bp in length. Some detoxification enzymes such as cytochrome P450 and Immune-related genes such as antimicrobial peptides were up-regulated after parasitism. Expression of symbiotic ichnovirus genes was detected in parasitized larvae with 55 contigs identified from five ichnovirus gene families including vankyrin, viral innexin, repeat elements, a cysteine-rich motif, and polar residue rich protein. This investigation provides a detailed information on differential expression of P. xylostella larval genes and symbiotic ichnovirus genes following parasitization.
        70.
        2012.10 구독 인증기관·개인회원 무료
        To collect entomopathogenic fungi we sampled soils from two different cultural types of farm which are conducting conventional culture and organic culture, and non-crop land. Forty-seven soil samples were collected from 9 provinces. Among them, 7 samples were collected from non-crop land, 6 samples were from organic farm and 34 samples were from conventional culture farm. Insect-bait method using Galleria mellonella and agar plating method were conducted to collect entomopathogenic fungi. Collection of entomopathogenic fungi using insect-bait method was highest in non-crop land as 7.1 mycotic cadavers per soil sample followed by organic farm with 3.6 and conventional farm with 3.3. Result from agar plating method showed the highest colony forming unit (cfu) was in organic farm followed by non-crop land, but cfu in conventional cultivating farm was a half compared with the non-crop land.
        72.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to examine the effects of gait training using functional electrical stimulation on the improvement of hemiplegic patients' functions for balance and gait velocity. The subjects of the experiment were determined to be 10 each hemiplegic patients who had been diagnosed with stroke or brain damage six months or longer earlier assigned to an experimental group and a control group respectively. The subjects were evaluated before the experiment using Tetrax and 10M gait tests, received gait training five times a week for four weeks using functional electrical stimulation and were evaluated after the experiment in the same method as used in the evaluation before the experiment. In order to examine differences between the experimental group that received gait training using functional electrical stimulation and the control group that was treated by functional electrical stimulation and received gait training thereafter, differences between before and after the experiment were analyzed using paired sample t-tests and differences in changes after the experiment between the experimental group and the control group were analyzed using independent sample t-tests in order to compare the two groups with each other. Experimental results showed significant differences in weight bearing, balance and gait velocity between before and after the experiment in the experimental group(p<.05). In the control group, whereas weight bearing and gait velocity did not show any significant difference between before and after the experiment(p>.05), balance showed significant differences(p<.05). Weight bearing, balance and gait velocity change rates showed significant differences between the experimental group and the control group(p<.05). In conclusion, it was indicated that gait training using functional electrical stimulation is effective for enhancing stroke patients' weight bearing rates, balance abilities and gait velocity.
        4,000원
        73.
        2011.10 구독 인증기관·개인회원 무료
        Testes‐derived unipotent male germ‐line stem (GS) cells can acquire multipotency under appropriate culture conditions to become mGS cells which can contribute to all three germ‐layers. This study was designed to investigate the epigenetic characteristics of mGS cells derived from adult mouse testes (maGS cells). The GS cells were isolated from 4 6 week DBA mouse and were cultured in Dulbecco’s modified Eagle Medium supplemented with 15% (v/v) fetal bovine serum, 1,000 U/ml LIF, 4 ng/ml GDNF at 37℃ in an humidified atmosphere of 5% CO2 in air to derive the maGS cells. The multipotency of maGS cells were verified by morphological and gene expression analyses, teratoma formation upon transplantation into nude mouse and in vitro differentiation ability. Bisulfite genomic sequencing revealed that GS cells had androgenetic DNA methylation pattern at the Igf2‐H19, Gnas‐Nespas , and Dlk1‐Dio3 imprinted gene clusters which changed to hemi‐zygotic embryonic stem (ES)‐cell like pattern in the maGS cells. Western blot analysis, using modification‐ and residue‐specific antibodies, revealed that both maGS and ES cells had similar level of histone di‐methylation at 4th and 27th lysine residue of histone 3 (H3K4me2 and H3K27me2) which represent “bivalent domain” for regulating self‐renewal and differentiation of mouse ES cells. Both maGS and ES cells also shared similar hisone modification for H3K9me2, H3K79me2, H3K9ac and H3K18ac. However, maGS cells had higher level of H3K- 36me2 and H3S10p. These data suggest that maGS and ES cells share several epigenetic characteristics but they also have their own unique epigenetic marks that may be useful as a molecular marker for their identification.
        74.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a list of Korean fungivorous Tenebrionidae associated with higher fungi (Basidiomycetes). Most fungivorous tenebrionids are associated with the order Aphyllophorales. A total of31 Tenebrionid species (both adults and larvae) belonging to four tribes (Bolitophagini, Toxicini, Scaphidernini, and Diaperini) are presented in our checklist. Of these, 62 percent are obligate mycetobionts, In addition, 42 fungal hosts of fungivorous tenebrionids are presented. Both thetenebrionids and the fungal hosts reported here are found throughout Korea.
        4,000원
        77.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate and reveal the effects that the complex exercise training consisting of aerobic exercise and strength training(sit up, push up) that everyone can easily practice regardless of a time and a place in order to manage practically the physical strength of the aged affects the difference on their body composition and the change of physical fitness level. Looking into the change of body composition of an experimental group, the weight of 2.5kg was reduced after applying complex training for 12 weeks and the body fat mass of 2.65kg was reduced. Also, the abdominal fat of 0.13% was decreased and the muscle mass of 1.56kg was increased. For the change factors of physical fitness, cardiovascular endurance, muscular strength, muscular endurance, balance and flexibility excluding agility showed significant improvement after applying complex exercise training. The improvement of health fitness of the aged under this study was significantly effective to improve specified body functions which had been lowered by aging and insufficient physical activities. So, it is regarded that their health fitness is the important factor to improve the activity competence required for daily life and to lead healthy living by the improved activity competence. Henceforth, it needs to study more the complex composition of several sports, exercise intensity and the frequency based on the previous researches and studies. In addition, it needs to develop the complex exercise training in accordance with various characteristics such as a sex of the aged, an age, a physical fitness level, environment, a disease and the program in consideration of the efficacy and safety during training.
        4,000원
        78.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reveal how EA affects BAX and NF-kB involved in cell deaths from global ischemia, and to do this, observes the changes of BAX and NF-kB caused by EA application after transient global ischemia. The experimental method is to give rise to global ischemia and apply EA to 27 SD rats with the particulars of being six-week-old, male, around-300 gram-weighing, and adapted to laboratory environment for more than a week, and divide them into three groups, that is, GV20 EA group(n=9), L14 EA group(n=9), no-treatment GI group(n=9), and then observe their changes of BAX and NF-kB at the time lapse of 6 hours, 9 hours and 12 hours after ischemia, using western blotting. The numerical decrease of BAX expression at the time lapse of 9 hours after EA application, though not statistically significant, was observed in GV20 EA group and L14 EA group, and the NF-kB expression appeared statistically significant decrease in GV20 EA group and L14 EA group, but the expression was higher in the group with EA application. Therefore, EA application at the early phase of global ischemia is considered to affect BAX and NF-kB and play a positive role in decreasing apoptosis and cell deaths by inflammation.
        4,000원
        79.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to determine the effects of heat appli˗ cation on the immune activities of the human body. To exam, further˗ more, the immune effect from the healthy volunteer(male:15, female:15) by monitoring changes of immune substances such as various leukocytes[total white blood cell(WBC), eosinophil, neutrophil, basophil, monocyte, and lymphocyte], a comparative study with warm water immersion(40.8±0.3℃) and infrared(250W) was carried out. The plasma analysis showed that the count of white blood cell, eosinophil, and neutrophil were elevated in warm water immersion- or infrared˗ stimulated group compared with control group. However, the count of basophil was decreased in both warm water immersion- and infrared-stimulated group than control group. Therefore, these results suggest that the thermostimulation improved immune activity.
        4,000원
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