검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 169

        42.
        2019.04 구독 인증기관·개인회원 무료
        Here, we investigated antioxidant defense mechanism in the spermatheca of A. mellifera queens via RNA-seq analysis of spermathecae in both mated and virgin queens. We identified the genes encoding antioxidant proteins, which were differentially expressed in the spermatheca of mated queens. The concentrations of antioxidant proteins, such as superoxide dismutase 1 (SOD1), catalase, glutathione peroxidase (GTPX), and transferrin (Tf) together with the levels of ROS, H2O2, and iron were higher in the spermathecal fluid of mated queens as opposed to those in the spermathecal fluid of virgin queens; this indicated that increase in antioxidant protein concentration is an antioxidant defense mechanism occurring in the spermathecal fluid of mated queens against ROS; this mechanism involves conversion of ROS using antioxidant enzymes and Tf-mediated inhibition of the Fenton reaction occurring between Fe2+ and H2O2. Our data indicate that an increased expression of antioxidant proteins could facilitate prolonged storage and survival of sperms in the spermatheca of mated queens, suggesting the role of antioxidant proteins in antioxidative defense against ROS.
        43.
        2019.04 구독 인증기관·개인회원 무료
        The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pest species, because it devastates many horticultural and ornamental crops and fruit trees. The resistance ratios calculated for the LC50 value in acequinocyl- and pyridaben-resistant strain was 4,237- and 5,555-fold higher than that of the susceptible strain, respectively. The objective of this study was to evaluate the cross-resistance to several acaricides and to identify the mechanisms associated with acequinocyl- and pyridaben-resistant strain of T. urticae.
        44.
        2019.04 구독 인증기관·개인회원 무료
        A residual contact vial plus water (RCVpW) bioassay method was established to monitor insectiside resistance in field populations of the melon thrips, Thrips palmi. Resistance level against six major insecticides were evalutated in five regions to test applicability of RCVpW as an on-site resistance monitoring tool. Reduced mortality in response to six test insecticides were exhibited compared to the RDA susceptable strain showing 100 % mortality, indicating different degree of resistance. An apparently reduced mortality to emamectin benzoate and chlofenapyr was observed in some field populations, suggesting uneven distribution of resistance to these insecticides in field populations. In addition, spinosad resistance was high and widely distributed in the test regions. Synergistic bioassay revealed that cytochrome P450-mediated metabolic factor is involved in spinosad resistance in the Korean population.
        46.
        2018.11 구독 인증기관·개인회원 무료
        Recent transcriptome analyses have shown that long non-coding RNAs (ncRNAs) play prevalent roles in transcriptional regulation. We have reported that promoter-associated ncRNAs (pancRNAs) activate the partner gene expression via local epigenetic changes. Here, we identify thousands of genes under the pancRNA-mediated transcriptional regulation in five mammalian species in common. In the mouse, 1) pancRNA-partnered genes show tissue-specific expression pattern, 2) expression of pancRNAs significantly enriched H3K4me3 and H3K27ac marks towards the partner gene expression, 3) H3K4me1 marks the pancRNA-partnered genes regardless of their expression level, and 4) C- or G-skewed motifs were exclusively overrepresented between -200 and -1 bp relative to the transcription start sites of pancRNA-partnered genes. More importantly, the comparative transcriptome analysis among five different mammalian species using a total of 25 counterpart tissues showed that overall pancRNA expression profile exhibited extremely high species-specificity compared to that of mRNA, suggesting that a significant number of pancRNAs contributed to the enhancement of a set of partner genes' expression in a sequence-specific manner. We conclude that the gain and/or loss of gene-activation-associated pancRNA repertories, caused by formation or disorganization of the genomic GC-skewed structure, finely shapes tissue-specific pattern of gene expression according to a given species.
        47.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a food-borne bacterial pathogen that causes various diseases in both humans and animals such as hemorrhagic colitis and hemolytic uremic syndrome. Because cattle are the main reservoir of this microorganism, undercooked meat and meat byproducts contaminated with EHEC O157:H7 are most commonly associated with epidemic disease outbreaks. As an enteric pathogen, EHEC O157:H7 enters the body via a fecal-oral route and must survive passage through the gastric stomach at pH 1.5 to 3.5 to establish an infection within the gastrointestinal tracts. Therefore, the ability to resist such acidic environments is important to the pathogenesis of EHEC O157:H7 during a host infection. In this review, we will discuss on the acid resistance (AR) mechanisms induced by EHEC O157:H7 when E. coli encounters acidic environments.
        4,000원
        48.
        2018.10 구독 인증기관·개인회원 무료
        Phosphine (PH3) resistance in the stored-products insect pests has been reported throughout the world in various insect species, including Rhyzopertha dominica, Tribolium castaneum, and Cryptolestes ferrugineus, leading farmers and fumigators to identify new fumigation tools to control PH3-resistant insect pests in storage facilities. Understanding PH3-resistance mechanisms in insects might contribute to providing clues for the development of new chemicals, including fumigants, to control various PH3-resistant insects. A proteomic study has shown 15 decreased proteins in the PH3-resistant R. dominica (CRD343 strain) in comparison to the PH3-susceptible R. dominica, and among those 15 proteins, dihydrolipoamide dehydrogenase (DLD), a protein involved in the Krebs cycle, was identified (Park et al., 2008). The DLD polymorphisms responsible for genetic resistance have disulfide active sites for PH3 binding and are highly sensitive to arsenic exposure after mutagenesis in insects (R. dominica and T. castaneum) and Caenorhabditis elegans (Schlipalius et al., 2012). Here, two PH3- resistant S. oryzae strains were used to understand the development of PH3 resistance in these insects. Acute toxicity test by PH3 on the two PH3-resistant strains was undertaken followed by ethyl formate inhibition study on cytochrome c oxidase activity. The Lineweaver-Burk plots after inhibition studies showed there were significantly difference in inhibition mode between the resistant strains and the control. The RT-qPCR analysis and the next-generation sequencing of the mitochondrial DNA revealed significant changes in metabolism and energy production. Taken together, the PH3 resistance in S. oryzae was definitely acquired by the overall transformation of biochemical reactions to overcome PH3 toxicity.
        49.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Extreme temperatures and precipitations are expected to be more frequently occurring due to the ongoing global warming over the Korean Peninsula. However, few studies have analyzed the synoptic weather patterns associated with extreme events in a warming world. Here, the atmospheric patterns related to future extreme events are first analyzed using the HadGEM3-RA regional climate model. Simulations showed that the variability of temperature and precipitation will increase in the future (2051-2100) compared to the present (1981-2005), accompanying the more frequent occurrence of extreme events. Warm advection from East China and lower latitudes, a stagnant anticyclone, and local foehn wind are responsible for the extreme temperature (daily T>38 o C) episodes in Korea. The extreme precipitation cases (>500 mm day−1 ) were mainly caused by mid-latitude cyclones approaching the Korean Peninsula, along with the enhanced Changma front by supplying water vapor into the East China Sea. These future synoptic-scale features are similar to those of present extreme events. Therefore, our results suggest that, in order to accurately understand future extreme events, we should consider not only the effects of anthropogenic greenhouse gases or aerosol increases, but also small-scale topographic conditions and the internal variations of climate systems.
        4,800원
        50.
        2018.04 구독 인증기관·개인회원 무료
        Mosquitoes are transmit many dangerous disease such as malaria, yellow fever and dengue fever. So far, chemical insecticides such as DEET have been mainly used to control mosquitoes, but there are many side effects. This study used ultrasonic sounds as an alternative to chemical insecticides. We found that Culex pipiens, which are common in Korea, exhibit avoidance behavior in a specific ultrasonic frequency. Through electrophysiological recording, we have inferred that avoidance behavior is caused by different from each other mechanisms depending on the ultrasonic frequency. Using immunohistochemical staining, we analyzed the expression pattern of auditory related genes in the chordotonal organ. Quantitative real time-PCR was used to compare the expression levels of auditory related gene depending on the time of exposure to ultrasonic sounds.
        51.
        2018.04 구독 인증기관·개인회원 무료
        한반도에서의 기후 변화는 최근까지 해충이 아니던 토착 곤충이나 비례 곤충들이 해충화 될 수 있는 가능성을 높여주고 있다. 가장 중요한 예가 토착 곤충이던 풀무치의 대량 발생에 따른 해충화가 있다. 낮은 밀도에서는 식생에 위험을 주지 않는 단독형으로 존재를 하던 풀무치가 평균온도의 상승과 강우 패턴의 변화로 대량 발생을 하여 강력한 이동성을 가지고 식생을 파괴하는 군집형으로 변화된 예가 있다. 하지만, 아직까지, 단독형에서 군집형으 로의 변화에 대한 기전이해는 완성이 되지 않은 상태이다. 기후의 변화는 겨울철 평균기온의 상승을 가져와서 한반도에서 월동이 불가능했던 해충이나 약제 저항성 계통들이 급속도로 번식할 수 있는 가능성을 열어 놓았다. 그러므로, 이러한 약제 저항성과 기후변화와 관련성에 대한 유전자 수준에서의 변화에 대한 이해가 필요한 실정이다. 위의 목적을 달성하기 위하여 우리는 다중분석학을 이용하여 연구를 진행하여 왔고, 연구 결과를 바탕으로 종 특이적이면 환경 친화적인 방제방법의 개발 연구를 진행하여 와서 이에 대한 연구결과를 발표한다(RDA Grant No. PJ010821032018).
        52.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        홍합 족사 단백질은 수분이 있는 표면에서도 강한 접착력을 가진다. 홍합 연구에 대표가 되는 marine blue mussel을 통해 9가지 단백질의 구조와 기능이 보고되었으며, 이 단백질들은 홍합 족사를 구성하는 실(threads)과 플래크(plaques)를 형성한다. 알려진 바에 의하면, 히드록시기 2개가 포함된 카테콜 기 능기를 가진 DOPA 물질이 계면접착(adhesion)과 내부결합(cohesion) 과정에서 중요한 역할을 하는 것으로 알려져 있다. 본 논문에서는, 최근 10년간 활발히 연구된 계면접착과 내부응력 메카니즘에 대해 소개하고 평가하였다. 또한, 접착력을 갖는 기능기를 활용한 발전된 접착소재의 개발, 바이오접착제와 의료용 소재로 응용가능성에 대해 살펴보았다. 홍합 단백질이 다시 관심의 대상이 되면서, 바이오소재로 사용될 가능성이 커지고 있음이 주목된다.
        4,000원
        53.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        멤브레인 파울링은 지표수를 처리하는 저압 멤브레인 기술 적용의 확장에 있어 큰 장애가 된다. 따라서 파울링 제어를 위한 주기적인 수리학적 세정기술의 최적화는 매우 중요하다. 주기적인 수리학적 세정과 이와 연관된 파울링 현상에 관한 올바른 이해는 멤브레인 세정 전략을 최적화하기 위해 매우 유용할 수 있다. 실험적으로 측정한 투과도와 전통적인 Hermia 파울링 모델 예측 치의 비교를 통해, 본 연구에서는 합성 탁도유발 시료를 처리하는 가압식 멤브레인 공정에서 30분 여과와 정세정/역세정이 포함된 1분 세정조건을 바탕으로 6번의 운전사이클을 통해 발생하는 파울링 현상을 분석하고 이를 통해 지배적인 파울링 기작을 정량적으로 이해하고자 하였다. 단독 세정에서, 첫 번째 운전사이클에서 발생하는 파울링은 완 전공극막힘 현상에 의해 주로 지배되었고 마지막 운전 사이클에서는 케이크 형성이 지배적인 파울링 기작으로 관찰되었다. 정세정과 역세정이 혼합된 경우, 파울링 속도는 감소하였으나 전반적으로 케이크 형성이 주 파울링 기작으로 관찰되었다.
        4,000원
        54.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1996년에 창설된 타이페이 비엔날레(TB)의 기획 메커니즘은 타이완 출신 큐레이터들의 공동 기획 체제(1996)로부터 일본 출신의 단일 큐레이터 체제(1998), 그리고 해외 큐레이터와 국내 큐레이터가 협업하는 이원 큐레이터 체제(2000-2010)를 거쳐서 다시 단일 큐레이터 체제(2012-2016)으로 회귀하기까지 다양한 과정을 겪었다. 특히 최근 단계에서는 서구 출신의 큐레이터들이 주도권을 장악해 왔다. 본 논문에서는 타이페이 비엔날레의 창립 당시 목표와 후대의 전개 양상 사이의 괴리 현상을 분석한다. 연구자는 이 행사가 타이완의 복합적인 지역 담론과 쟁점들을 제대로 반영하지 못하고 단순히 동시대 국제 비엔날레의 추세를 수용하는데 머 물러 왔으며, 그 배경에 타이페이 비엔날레의 기획 메커니즘 뒤에 작용하고 있는 ‘자기 식민 지화’의 경향이 존재한다고 주장한다.
        6,000원
        55.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 다국적기업 본사의 해외 자회사에 대한 통제 방식 및 통제 방식들 간의 상호작용이 자회사 현지 직 원의 조직일체감에 미치는 영향을 살펴보는 것을 목적으로 하고 있다. 이를 위해 한국에서 경영활동을 수행하고 있는 11개국 출신의 47개 다국적기업 자회사에 근무 중인 447명의 현지 직원들로부터 수집한 자료를 바탕으로 위계적 선형모형 분석을 실시하였다. 실증분석 결과, 본사의 집권화는 자회사 현지 직원의 조직일체감에 부(-)의 영향을 미치고, 본사의 공식화와 사회화는 자회사 현지 직원의 조직일체감에 정(+)의 영향을 미치는 것으로 나 타났다. 그리고 본사의 집권화와 조직일체감 간의 부(-)의 관계는 공식화와 사회화 수준이 모두 높을수록 가장 약한 것으로 나타나, 자회사 현지 직원의 조직일체감에 영향을 미치는 통제 방식들 간의 3차 상호작용 효과가 존 재함을 확인하였다.
        7,700원
        57.
        2017.10 구독 인증기관·개인회원 무료
        Ethyl formate has been used for the control of insect pests by fumigation. However, there were not many reports toshow its target site of fumigant toxicity on insect pests since its first use in the agricultural industry. In the present study,we showed the presumable target sites of ethyl formate fumigation in insect pests using Myzus persicae nymphs. Afterethyl formate fumigation, the nymphs of this species were collected and the changes at the biochemical and molecularlevel were determined. The activity of cytochrome c oxidase (COX) was approximately two-fold higher after ethyl formatefumigation. In addition, the expression levels of acetylcholinesterase (AChE) decreased gradually with increasing ethylformate concentration. These two findings suggested that COX and AChE might be the major target sites of ethyl formatefumigation. In addition to these results, the analysis of lipid content using MALDI-TOF MS/MS identified 9 phospholipidsdifferently generated 2-fold higher in the ethyl formate-treated nymphs than that in the control nymphs, thereby leadingto changes in cell membrane composition in M. persicae nymphs. Therefore, the ethyl formate fumigation caused lethaleffects on M. persicae nymphs by changing COX activity, AChE gene expression, and phospholipid production.
        58.
        2017.10 구독 인증기관·개인회원 무료
        The mosquito is a dangerous disease vector, which transfers various diseases like dengue virus, Zika virus and malaria.This study used an alternative way of mosquito repellent agents rather than chemical repellents such as DEET. We haveemployed a novel emitters of ultra-sonic sounds, which showed repellent effects to mosquito behaviors that avoid ultra-sonicsounds. Using NGS analysis after ultrasonic treatment, we found that some subsets of sensory and other related geneswere affected, indicating that ultrasonic sounds affects gene expression associated with host finding behaviors in Aedesaegypti. Additionally, we performed electrophysiological recording and behavior assay testing repellency in a chamberin Culex pipiens, which is the most common species in Korea.
        59.
        2017.10 구독 인증기관·개인회원 무료
        Light is a necessary environmental factor for stroma formation and development of Cordyceps militaris, a well-known edible and medicinal fungus. In this study, photo morphogenesis and the blue-light receptor gene were studied using five representative strains of C. militaris. The results suggest that light was essential for colony pigmentation and could promote conidia production. Cmwc-1 gene inactivation results in thicker aerial hyphae, disordered fruit body development, a significant reduction in conidial formation, and carotenoid and cordycepin production. These characteristics were restored when the ΔCmwc-1 strains were hybridized with wild-type strains of the opposite mating type. A genomewide expression analysis revealed that there were 1042 light responsive genes in the wild-type strain and only 458 in the ΔCmwc-1 strain. Among five putative photoreceptors identified, Vivid, cryptochrome-1, and cyclobutane pyrimidine dimer photolyase are strongly induced by light in a Cmwc-1- dependent manner, while phytochrome and cryptochrome-2 were not induced. The transcription factors involved in the fungal light reaction were mainly of the Zn2Cys6 type. CmWC-1 regulates adenylosuccinate synthase, an important enzyme for adenosine de novo synthesis, which could explain the reduction in cordycepin production. Some G proteincoupled receptors that control fungal fruit body formation and the sexual cycle were regulated by CmWC-1, and the cAMP pathway involved in light signal transduction in N. crassa was not critical for the photoreaction in the fungus here. A transcriptional analysis indicated that steroid biosynthesis was more active in the ΔCmwc-1 strain, suggesting that CmWC-1 might switch the vegetative growth state to primordia differentiation by suppressing the expression of related genes.
        1 2 3 4 5