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        검색결과 612

        185.
        2017.10 구독 인증기관·개인회원 무료
        Aphidius colemani has been used as commercially available natural enemies for the aphid control. However, some siblingspecies are difficult to distinguish their morphology even though they have different parasitic characteristics. Recentlywe identified overwintering parasitoids inside the aphid mummies at the pepper greenhouse in Yecheon. The nucleotidesequence analysis identified as A. transcaspicus which is morphologically similar with A. colemani. Those genetic differencesof COI and ITS2 sequences were 4.36-4.84% and 2.65-5.84%, respectively. While A. colemani is useful for the controlof Aphis gossypii and Myzus persicae, A. transcaspicus parasitize various species belongs to the genera Hyalopterus, Melanaphisand Rhopalosiphum. Thus, precise diagnosis of natural enemies is required for the successful pest control.
        186.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Effective estrus detection and artificial insemination (AI) are necessary for profitable management of dairy herd. In current study, 45 crossbred lactating cows have been selected with the complaint of unobserved oestrus for more than sixty days postpartum. All cows had functional corpus luteum as examined by transrectal ultrasonography. Cows were treated with PGF2α analogue and AI was performed with observed oestrus and then single dose of GnRH was administered. Similar synchronization protocol has been repeated after 14 days in cows that did not repose to first treatment. Remaining cows received additional PGF2α after 14 days of second treatment and timed AI was performed following GnRH administration. Among 45 cows, 28.89% showed estrus after first treatment and 78.79% responded to second hormonal intervention. A higher conception rate (88.89% vs 26.66 and 72.72%) was observed in cows after triple administration of PGF2α and timed AI. We noticed a significant differences in body condition score (BCS, 1~5 scale), postpartum period, and daily milk production between cows that either responded of non-responded following first and second hormonal treatment. In addition, there was a significant positive correlation between daily milk production and BCS, age and postpartum days, milk production and estrus/BCS, and milk production/BCS/estrus and conception rate. Depending upon the findings we conclude that hormonal intervention with PGF2α and GnRH enhances postpartum ovarian cyclicity and help decreasing the days open of dairy herd. Therefore, this finding might provide an excellent guideline for target breeding system for profitable dairy herd management.
        4,000원
        188.
        2017.04 구독 인증기관·개인회원 무료
        It has been proved that agroinfiltration-based temporary expression of coatomer subunit alpha (COPA) gene from Tetranychus urticae hairpin RNA induces RNA interference (RNAi) and lethality to T. urticae. To establish detailed protocols for agroinfiltration, the efficiency of agroinfiltration to the soybean and kidney bean was determined with respect to different Agrobacterium delivery methods (sea sand, carborundum and syringe) and the spacial expression patterns of hairpin RNA was investigated following Agrobacterium delivery. Sea sand and syringe showed the highest expression level in soybean and kidney bean, respectively. Considering the resulting tissue damage, syringe appeared the best choice for agroinfiltration in both soybean and kidney bean. The apical region of a leaf showed more relative expression levels in both soybean and kidney bean compared to the basal region. Following agroinfiltration, adjacent untreated leaves were determined to express hairpin RNA though the expression level was low, suggesting that hairpin RNA can be translocated to other leaves. In conclusion, Agrobacterium delivery by syringe and use of whole leaf were recommended for T. urticae bioassay following agroinfiltration.
        189.
        2017.04 구독 인증기관·개인회원 무료
        The toxicity of neem extracts that induce abnormality and lethality is strongly enhanced by the ingestion rather than surface contact. Oral toxicity of neem extracts was analyzed using a plant sapping pest Bemisia tabaci. When adults were allowed to ingest various doses (0, 5, 10, and 50 ppm) of azadirachtin diluted in 20% sugar solution in a double-layered parafilm chamber for 72 h, mortality was 12.5, 77.5, 97.5, 100%, respectively. When a cucumber leaf which has many nymphs were submerged into the solution of neem extract, adult eclosion was decreased to 87.0, 16.6, 16.1, and 6.6%, respectively. Further, when neem extracts were irrigated into the tomato cultivar the average number of nymphs per leaf was decreased to 60.3% in comparison with the untreated control. These result suggest that systemic treatment of neem extracts was effective for the control of whiteflies as well as other sucking insect pests.
        190.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the results of BV time-series photometry of the globular cluster NGC 288. Ob- servations were carried out to search for variable stars using the Korea Microlensing Telescope Network (KMTNet) 1.6-m telescopes and a 4k pre-science CCD camera during a test observation from August to December, 2014. We found a new SX Phe star and confirmed twelve previously known variable stars in NGC 288. For the semi-regular variable star V1, we newly determined a period of 37.3 days from light curves spanning 137 days. The light-curve solution of the eclipsing binary V10 indicates that the system is probably a detached system. The pulsation properties of nine SX Phe stars were examined by applying multiple frequency analysis to their light curves. We derived a new Period-Luminosity (P-L) relation, hMV i = −2.476(±0.300) logP − 0.354(±0.385), from six SX Phe stars showing the fundamental mode. Additionally, the period ratios of three SX Phe stars that probably have a double-radial mode were investigated; PFO/PF = 0.779 for V5, PTO/PFO = 0.685 for V9, PSO/PFO = 0.811 for V11. This paper is the first contribution in a series assessing the detections and properties of variable stars in six southern globular clusters with the KMTNet system.
        4,300원
        191.
        2016.12 구독 인증기관 무료, 개인회원 유료
        Inhibition of Rho-associated coiled coil-containing kinase (ROCK) has been reported to promote differentiation of neuronal cells. Here, we examined the effect of Y-27632, a ROCK inhibitor, on the outgrowth of neurites in PC12 cells. Y-27632 caused a rapid induction of neurite outgrowth in PC12 cells in a time-dependent manner. The neurite outgrowth, triggered by Y-27632, was accompanied by Rac1 activation, and was attenuated by Rac1 inhibitor NSC23766, in a concentration-dependent manner. Y-27632 also induced an increase in the production of reactive oxygen species (ROS). Pretreatment with N-acetylcysteine, an ROS scavenger, inhibited the ROS generation and neurite outgrowth in response to Y-27632. These results indicate that the activation of Rac1 and the generation of ROS contribute to the neurite outgrowth triggered by Y-27632 in PC12 cells.
        4,000원
        192.
        2016.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present photometric results of the  Sct star V1162 Ori, which is extensively monitored for a total of 49 nights from mid-December 2014 to early-March 2015. The observations are made with three KMTNet (Korea Microlensing Telescope Network) 1.6 m telescopes installed in Chile, South Africa, and Australia. Multiple frequency analysis is applied to the data and resulted in clear detection of seven frequencies without an alias problem: five known frequencies and two new ones with small amplitudes of 1.2-1.7 mmag. The amplitudes of all but one frequency are significantly different from previous results, confirming the existence of long-term amplitude changes. We examine the variations in pulsation timings of V1162 Ori for about 30 years by using the times of maximum light obtained from our data and collected from the literatures. The O − C (Observed minus Calculated) timing diagram shows a combination of a downward parabolic variation with a period decreasing rate of (1/P)dP/dt = −4.22 × 10−6 year−1 and a cyclic change with a period of about 2780 days. The most probable explanation for this cyclic variation is the light-travel-time effect caused by an unknown binary companion, which has a minimum mass of 0.69 M⊙. V1162 Ori is the first  Sct-type pulsating star of which the observed fast period decrease can be interpreted as an evolutionary effect of a pre-main sequence star, considering its membership of the Orion OB 1c association.
        4,000원