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        검색결과 11

        1.
        2016.10 구독 인증기관·개인회원 무료
        We investigated pollination and foraging activities of honeybee (Apis mellifera L.) and bumblebee (Bombus terrestris L.) during flowering season of the asian pear (Pyrus pyrifolia N.) under different weather conditions. There was no significant statistical difference about the pollination activities of two species. However, the pollination activities of bumblebee were more active than those of honeybee under low temperature and rainfall period. The activities of honeybee and bumblebee were more influenced by temperature than other factors (i.e. illumination and wind velocity). Honeybee was more sensitive to temperature and illumination than bumblebee. At low temperatures (<20℃) on cloudy days (<30,000 lux) with a certain wind velocity (>4.0 m/s), the pollination activity of the honeybee was lower twice than that of bumblebee.
        2.
        2015.10 구독 인증기관·개인회원 무료
        Bees of the genus Osmia are cavity-nesting solitary species that play important roles as pollinators. Nest traps are one of the most common methods to study Osmia bees. To elucidate the optimal environmental conditions of nesting sites, we investigated the effects of location, direction, altitude, and sites of nest traps on the rate of trap-nesting Osmia spp. During the collection period, the average rate of trap-nesting Osmia spp. collected within 90 days after the installation of traps was 17.0±20.0%. This percentage was 2.7-fold higher than that of trap-nesting bees in 30 days after the installation of traps. The Jeongseon location exhibited the highest rates of trap-nesting Osmia spp. collected in 30 and 90 days, representing 11.1 ±17.6% and 23.2±22.5%, respectively. The direction of the nest traps did not affect the rate of trap-nesting Osmia spp. The altitude ranges of the traps were 0-199 m, 200-399 m, 400-599 m, 600-799 m and over 800 m. Interestingly, the altitude range of 600-799 m showed the highest rate of trap-nesting bees, which was 40.4±3.9%. Higher altitudes seemed to correspond to higher rates of trap-nesting bees. With regards to the sites where the nests were placed, the rate of trap-nesting bees in a mud wall of an old house was 45.1±25.2%, which was 3-fold higher than that of a nest in an apple orchard. The flowering plants collected at different locations during the trap-nesting activity of Osmia bees belonged to 18 families and 34 species. In conclusion, the rates of trap nests colonized by Osmia spp. were affected by altitude, site, and plant diversity.
        3.
        2012.10 구독 인증기관·개인회원 무료
        Among hemipteran insects which is the most important insect vector of plant viruses, small brown planthopper, Laodelphax striatellus, transmits the rice stripe virus (RSV) causing rice stripe disease. For effective control of RSV, it is important to understand interaction between RSV and L. striatellus. Therefore, in this study, expressed sequence tag (EST) databases were generated based on 454 GS-FLX pyrosequencing for comparative transcriptome analysis between nonviruliferous and RSV-viruliferous L. striatellus. By comparing the two EST libraries, we showed that 108 host genes were significantly up-regulated and 28 host genes were significantly down-regulated in viruliferous insects. Interestingly, genes encoding ribosomal proteins were mainly up-regulated in viruliferous L. striatellus, whereas genes related to translation were concentrated in the downregulated cohort. These RSV-dependently regulated genes may have important function in the behavior of planthopper or the transmission of RSV.
        4.
        2012.06 구독 인증기관·개인회원 무료
        Pluripotent stem cells can be derived from both pre- and post-implantation embryos. Embryonic stem cells (ES cells), derived from inner cell mass (ICM) of blastocyst are naïve pluripotent and epiblast stem cells (EpiSCs) derived from post-implantation epiblast are primed pluripotent. The phenotypes and gene expression patterns of the two pluripotent stem cells are different each other and EpiSCs thought to be in a more advanced pluripotent (primed pluripotent state) than mouse ES cells (naïve pluripotent state). Therefore, we questioned whether EpiSCs are less potential to be differentiated into specialized cell types in vitro. EpiSCs were isolated from 5.5~6.5 day post coitum mouse embryos of the post-implantation epiblast. The EpiSCs could differentiate into all tree germ layers in vivo, and expressed pluripotency markers (Oct4, Nanog). Interestingly, EpiSCs also were able to efficiently differentiate into neural stem cells (NSCs). The NSCs differentiated from EpiSCs (EpiSC-NSCs) expressed NSC markers (Nestin, Sox2, and Musasi), self-renewed over passage 20, and could differentiate into two neural subtypes, neurons, astrocytes and oligodendrocytes. Next, we compared global gene expression patterns of EpiSC-NSCs with that of NSCs differentiated from ES cells and brain tissue. Gene expression pattern of brain tissue derived NSCs were closer to ES cell-derived NSCs than EpiSC-NSCs, indicating that the pluripotent stem cell-derived somatic cells could have different characteristics depending on the origin of pluripotent stem cell types. * This work was supported by the Next Generation Bio-Green 21 Program funded by the Rural Development Administration (Grant PJ 008009).
        5.
        2011.10 구독 인증기관·개인회원 무료
        Bee venom is a rich source of pharmacologically active substances. In this study, we identified a bumblebee (Bombus ignitus) venom Kunitz-type serine protease inhibitor (Bi-KTI) that acts as a plasmin inhibitor. Bi-KTI showed no detectable inhibitory effect on factor Xa, thrombin, or tPA. However, it strongly inhibited plasmin, although this inhibitory ability was two-fold weaker than that of aprotinin. The activities of B. ignitusvenom serine protease (Bi-VSP) and plasmin in the presence of Bi-KTI indicate that Bi-KTI targets plasmin more specifically than Bi-VSP. These findings demonstrate a novel mechanism for bee venom by which Bi-KTI acts as an antifibrinolytic agent, raising interest in Bi-KTI as a potential clinical agent.
        6.
        2010.10 구독 인증기관·개인회원 무료
        Bee venom contains a variety of peptides and enzymes, including serine proteases. While the presence of serine proteases in bee venom has been demonstrated, the role of these proteins in bee venom has not been elucidated. Furthermore, there is currently no information available regarding the melanization response or the fibrin(ogen)olytic activity of bee venom serine protease, and the molecular mechanism of its action remains unknown. Here we show that bee venom serine protease (Bi-VSP) is a multifunctional enzyme. In insects, Bi-VSP acts as an arthropod prophenoloxidase (proPO)-activating factor (PPAF), thereby triggering the phenoloxidase (PO) cascade. Bi-VSP injected through the stinger induces a lethal melanization response in target insects by modulating the innate immune response. In mammals, Bi-VSP acts similarly to snake venom serine protease, which exhibits fibrin(ogen)olytic activity. Bi-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, defining roles forBi-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings provide a novel view of the mechanism of bee venom in which the bee venom serine protease kills target insects via a melanization strategy and exhibits fibrin(ogen)olytic activity.
        7.
        2009.10 구독 인증기관·개인회원 무료
        Bee venom contains a variety of toxic enzymes and peptides. One of the major components of bumblebee venom is bombolitin, which is the most abundant venom constituent and biologically similar to melittin. Here, we first show the molecular cloning and antimicrobial activity of the venom bombolitin from the bumblebee Bombus ignitus. The B. ignitus venom bombolitin gene consists of 2 exons, encoding 56 amino acid residues. The bombolitin purified from B. ignitus venom was the 2104 Da mature peptide with 18 amino acid residues, which are created by cleavage of the probombolitin domain between Ala38 and Leu39. We examined the pattern of bombolitin expression to confirm that it is a component of bumblebee venom. B. igniutus venom bombolitin exhibits venom gland-specific expression. We also investigated the venom bombolitin for antimicrobial properties against bacteria and fungi. The venom bombolitin showed high antibacterial activity against both Gram-negative and Gram-positive bacteria. Most interestingly, the venom bombolitin showed high antifungal activity against Fulvia falva, a leaf mold, and Alternaria radicia, a black rot. These antimicrobial profiles of B. ignitus venom bombolitin reported herein will be useful in the application for potential antimicrobial agents.
        8.
        2014.08 KCI 등재 서비스 종료(열람 제한)
        본 연구는 장애전담 어린이집에 재원 중인 발달지체유아를 대상으로 요일별 신체리듬을 고려한 원예활동 프로그램이 유아의 적응행동에 미치는 영향에 대해 알아보고자 하였다. 원예활동 대상자는 S장애전담 어린이집에서 4세~6세 발달지체유아 대조군 8명, 실험군 8명이었다. 원예활동 프로그램은 2012년 10월 15일부터 2012년 11월 22일까지 주 3회 30분씩 총 18회 실시하였다. 전체 적응행동 평가 결과 대조군의 경우 실험 전 65.00점에서 실험 후 66.00점으로 1.00점이 향상되었고 실험군은 전체 적응행동 평가 결과 실험 전 66.00점에서 실험 후 85.50점으로 19.50점이 향상되었다. 실험군의 하위항목별 변화를 살펴보면 개념적 적응행동은 원예활동 실시 전 64.00점에서 실시 후 80.75점으로, 사회적 적응행동은 65.50점에서 80.63점으로, 실제적 적응행동은 74.38점에서 95.38점으로 모든 항목이 원예활동 실시 후 유의하게 향상되는 것을 볼 수 있었다. 이상의 연구결과로부터 요일별 신체리듬의 변화와 유아의 흥미와 참여도를 고려하여 설계한 원예활동프로그램이 장애전담 어린이집 내에 재원하고 있는 발달지체유아들의 적응행동 향상에 효과적인 것으로 나타났다.