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        검색결과 1,328

        461.
        2018.11 구독 인증기관·개인회원 무료
        In this study, we examined sperm penetration and blastocyst developmental rate of oocytes to determine fertilizability of cauda epididymal spermatozoa in Hanwoo bull. One testicle with epididymides were castrated from one Hanwoo bull (14 months of age) and transported to laboratory. Spermatozoa recovered from cauda epididymis by mincing with semen extender (Optixcell, IMV, France) and cryporeserved in liquid nitrogen tank until use. As control, frozen Hanwoo semen was used. Cumulus oocyte complexes (COCs) were collected from follicles (2-8 mm) of slaughtered ovaries and 10 to15 COCs were matured in 50μl droplet with M-199 media supplemented with 10% fetal bovine serum, 10μg/ml FSH, 10μg/ml LH, 10μg/ml EGF for 22 to 24 hours in a humidified atmosphere of 5% CO2 in air. After maturation of COCs, matured COCs were co-incubated with cauda epididymal spermatozoa in 100μl droplet in modified Brackett and Oliphant media supplemented with 2.5 mM theophylline for 12 or 18 hours under 5% CO2 in air. Sperm concentration was adjusted to 5 × 106cells/ml. After IVF for 18 hours, presumptive zygotes were cultured in modified synthetic oviductal fluid with 1mM glutamine, 12 essential amino acids, 10 μg/ml insulin under 5% CO2, 5% O2 in air. In experiment 1, we examined sperm penetration rate at 12 hours of IVF of frozen-thawed epididymal sperm. Total penetration rate among cauda epididymis and control were not significantly different (mean±standard error, cauda epididymis and control vs. 49.7±11.3 and 54.4±12.8%) In experiment 2, cleavage and blastocyst development rate were evaluated at day 2 and day 8 after IVF for 18 hours. Cleavage rate among cauda epididymis and control was similar different (cauda epididymis and control vs. 81.2±3.4 and 82.7±2.5%). However, blastocyst developmental rate of cauda epididymis group was significantly higher than that of control group (cauda epididymis and control vs. 24.4±1.6 and 12.2±2.8%, p<0.05). In conclusion, cauda epididymal spermatozoa in Hanwoo bull has high fertilizability and embryo development. Cauda epididymal sperm can be used as an alternative to ejaculated frozen sperm in vitro.
        462.
        2018.11 구독 인증기관·개인회원 무료
        The transcription factor POU5F1, also known as OCT4 plays critical roles in maintaining pluripotency during early mammalian embryonic development and in embryonic stem cells. It is important to establish an OCT4 promoter region-based reporter system to study pluripotency. However, there is still a lack of information about the porcine OCT4 upstream region. To improve our understanding of the porcine OCT4 regulatory region, we identified conserved regions in the porcine OCT4 promoter upstream region by sequence-based comparative analysis using various mammalian genome sequences. The similarity of nucleotide sequences in the 5' upstream region was low among mammalian species. However, the OCT4 promoter and four regulatory regions, including distal and proximal enhancer elements, had high similarity. The putative transcription factor binding sites in the Oct4 5' upstream region nucleotide sequences from mice and pigs also differed. Some of these genes are related to pluripotency, and further research will allow us to better understand the differences in species-specific pluripotency. Next, a functional analysis of the porcine OCT4 promoter region was conducted. Luciferase reporter assay results indicated that the porcine OCT4 distal enhancer and proximal enhancer were highly activated in mouse embryonic stem cells and embryonic carcinoma cells, respectively. Similar to OCT4 upstream-based reporter systems derived from other species, the porcine OCT4 upstream region-based reporter constructs showed exclusive expression patterns depending on the state of pluripotency. This work provides basic information about the porcine OCT4 upstream region and various porcine OCT4 fluorescence reporter constructs, which can be applied to study species-specific pluripotency in early embryo development and the establishment of embryonic stem cells in pigs. This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03032256).
        463.
        2018.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the structural, morphological and magnetic properties of the Ni70Mn30 alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.
        4,000원
        465.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study conducted synoptic and mesoscale analyses to understand the cause of Japan Tsukuba tornado development, which occurred at 0340 UTC 6 May 2012. Prior to the tornado occurrence, there was a circular jet stream over Japan, and the surface was moist due to overnight precipitation. The circular jet stream brought cold and dry air to the upper-level atmosphere which let strong solar radiation heat the ground with clearing of sky cover. A tornadic supercell developed in the area of potentially unstable atmosphere. Sounding data at Tateno showed a capping inversion at 900 hPa at 0000 UTC 6 May. Strong insolation in early morning hours and removal of the inversion instigated vigorous updraft with rotation due to vertical shear in the upper-level atmosphere. This caused multiple tornadoes to occur from 0220 to 0340 UTC 6 May 2012. When comparing Tateno’s climatological temperature and dew-point temperature profile on the day of event, the mid-level atmosphere was moister than typical sounding in the region. This study showed that tornado development in Tsukuba was caused by a combination of (a) topography and potential vorticity anomaly, which increased vorticity over the Kanto Plain; (b) vertical shear, which produced horizontal vortex line; and c) thermal instability, which triggered supercell and tilted the vortex line in the vertical.
        4,900원
        467.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최 적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/ mL이 되도록 증균배지에 접종하고 30oC, 37oC, 42oC에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균 주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA 를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA 로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 42oC에서 증균된 샘플(5.4 ± 0.3 Log CFU/mL) 과 30oC에서 증균된 샘플(4.6 ± 0.6 Log CFU/mL) 간 유의 차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상 되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다.
        4,000원
        468.
        2018.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The DEEP-South (the Deep Ecliptic Patrol of the Southern Sky) photometric census of small Solar System bodies produces massive time-series data of variable, transient or moving objects as a by- product. To fully investigate unexplored variable phenomena, we present an application of multi-aperture photometry and FastBit indexing techniques for faster access to a portion of the DEEP-South year-one data. Our new pipeline is designed to perform automated point source detection, robust high-precision photometry and calibration of non-crowded fields which have overlap with previously surveyed areas. In this paper, we show some examples of catalog-based variability searches to find new variable stars and to recover targeted asteroids. We discover 21 new periodic variables with period ranging between 0.1 and 31 days, including four eclipsing binary systems (detached, over-contact, and ellipsoidal variables), one white dwarf/M dwarf pair candidate, and rotating variable stars. We also recover astrometry (< ±1–2 arcsec level accuracy) and photometry of two targeted near-earth asteroids, 2006 DZ169 and 1996 SK, along with the small- (0.12 mag) and relatively large-amplitude (0.5 mag) variations of their dominant rotational signals in R-band.
        4,600원
        473.
        2018.10 구독 인증기관·개인회원 무료
        Incursions of red imported fire ant (RIFA), Solenopsis invicta into Korea have been increasing. After a first interception of a colony of S. invicta on Gamman pier, Pusan port while intensive surveillance by Animal & Plant Quarantine Agency (APQA) in September 2017, three more RIFA colonies have been found in sea port piers of Pyeongtek, Incheon and Pusan cities. The social forms and mitochondrial DNA haplotypes of the intercepted RIFA colonies were analysed by allelic discrimination assay (peptide nucleic acid probe based RT-PCR) of Gp-9 gene and mt-DNA fragment of 768 bp, which is part of the Cytochrome oxidaseⅠ gene. The colony on Gamman pier, intercepted in Sep. 2017 was previously reported as a haplotype 5 (H5) of mitochondrial DNA and a social form of polygyne. The colony on Hutchison pier of Pusan port, intercepted in June 2018 were confirmed as a H22 haplotype and a monogyne. Those different social forms show different origins of each colonies. Those on piers of Pyeongtek and Incheon ports, also found in 2018 were confirmed samely as H22 and monogyne. However, it could be putatively assumed that those two colonies were differently introduced via different container cargoes, considering those colonies were found in container yards of distantly located different sea ports. More genetic variation analyses using diverse sets of molecular markers such as microsatellites, genome-wide single nucleotide polymorphisms, etc. in nuclear gens are being proceeded for more exact introduction routes (origins).
        474.
        2018.10 구독 인증기관·개인회원 무료
        농업용 무인멀티콥터를 활용한 방제면적은 수도작은 물론 밭작물에서도 방제 범위가 확대되고 있다. 밭작물은 작물의 형태가 다양하여 비행속도, 살포높이 등을 최적화하는 연구가 필요하다. 본 연구에서는 배추, 대파, 고추에서 발생하는 나방류에 대하여 무인멀티콥터의 살포 높이에 따른 방제효과를 확인하였다. 살포된 약제가 작물에 부착되는 정도를 조사한 결과, 배추는 2m, 대파는 3~4m, 고추는 모든 높이에서 비슷한 부착정도를 보였지만, 전체적으로 부착량이 적고 불균일 하였다. 살포 높이별 방제효과는 작물별로 각각 배추(9~10엽기)는 2m높이, 고추(약 1.2m)는 2~3m, 대파(약 60cm)는 2, 3, 4m 각각 비등한 방제효과를 보였다. 각각의 작물모두 경엽처리 대비 약효가 미흡하였으며, 고추는 4m높이 살포시 방제효과가 현저히 낮았다.
        475.
        2018.10 구독 인증기관·개인회원 무료
        멀티콥터(드론)을 이용한 약제 살포 효과 분석을 위해 배추의 파밤나방을 대상으로 살충제의 조건별 살포 실시 후 약효·약해를 조사하였다. 고정조건은 2M, 5M 고도 조건, 풍속 2m/s 이하이며, 오전 7~8시 경 파밤나방 1~2령을 대상으로 살충제 스피네토람 액상수화제를 기준량인 16배(1,250ml/20L)와 배량 8배(2,500ml/20L) 및 반량 32배(625ml/20L)를 살포한 결과 24시간 후 파밤나방 유충 100%가 사망하였다. 배추 잎에 외관상 나타나는 약해는 없었다.
        476.
        2018.10 구독 인증기관·개인회원 무료
        미국선녀벌레[Metcalfa pruinosa (Say, 1830)]는 북미 원산 해충으로 2009년 3개 시군에서 공식적으로 확인된 후, 2016년 60개 시군으로 급격히 분포지역이 확대된 침입 해충이다. 기주식물의 범위가 매우 넓고, 산림지역 방제의 어려움 등으로 발생밀도가 급격하게 증가하여 농작물 재배지에서 큰 피해를 주고 있다. 단감 포장내 30개 지점에 끈끈이트랩을 설치하여 시기별 발생 밀도와 포장주위에 약 15~20m 간격으로 끈끈이트랩을 설치하여 침입 및 이동을 조사하였다. 단감포장내에서 5월 중순부터 미국선녀벌레 약충이 발생하였고, 7월부터 성충이 발생하였으며 성충의 발생 최성기는 8월 중순이었다. 포장으로의 침입은 5월 하순에 가장 높았고, 8월 중순이후로는 포장에서 외부로 성충의 이동을 관찰할 수 있다.
        477.
        2018.10 구독 인증기관·개인회원 무료
        진딧물류의 기생성 천적인 쌍꼬리진디벌(Binozys communis)의 진딧물 밀도억제을 조사하기 위해 천적:진딧물을 1:15, 1:10, 1:5의 비율로 접종한 결과, 1:10으로 접종 시 5일차에 첫 머미가 발생하고, 진딧물의 총 개체수도 감소하기 시작하여 8일차부터 진딧물보다 머미의 수가 많아졌다. 쌍꼬리진디벌의 온도별 발육기간은 온도가 높아짐에 따라 알에서 머미까지의 발육기간은 짧아지며 20℃에서는 15.7, 25℃에서는 11.1일, 30℃에서는 10.0일이었고, 암컷 성충의 생육기간은 20℃에서는 3.1일, 25℃에서는 2.5일, 30℃에서는 1.5일이었다.
        478.
        2018.10 구독 인증기관·개인회원 무료
        The purpose of the present study was to evaluate if main domestic vector mosquitoes, Aedes albopictus as a diurnal species and Culex pipiens as a nocturnal species, have color preference for blood feeding activity. Laboratory evaluations were performed and compared to assess color attractiveness using seven fundamental colors including black, white, red, yellow, green, blue, and purple. The test bodies selected for these experiments were BioGents Sentinel traps (BG traps) with 20g dry ice in each falcon tube, which covered outside of the traps attached with each different color of vinyl sheets. In each experiment, a pair of BG traps was placed 0.6 m away from each other in a 1.8 m x 3.7 m x 1.8 m screened enclosure. The enclosure maintained at 26±2℃, 65±5% RH, and 100 lux illumination. Evaluations were performed for two hours between 10:00 and 16:00 for each 25 Ae. ablopictus females and 15 hours from 18:00 to 9:00 for each 25 Cx. pipiens females. The attraction rates were determined by a series of 42 simultaneous pairs of sample counts of the number of mosquitoes caught in the traps at every 30 minutes. As a result, black traps collected the largest number of Ae. albopictus as a mean 0.7 of 1.0 for Mosquito Preference Index (MPI), followed closely by red, blue, and purple (MPIs, 0.6) that were significantly higher (p<0.05) than those of green (MPI, 0.5), white (MPI, 0.3), and yellow (MPI, 0.2). Similarly, the MPIs for Cx. pipiens were significantly higher at black and red traps (MPIs, 0.7) but the MPIs (0.3) at white and yellow traps were significantly lower than those of the other colors.
        479.
        2018.10 구독 인증기관·개인회원 무료
        The purpose of the present study was to evaluate if main domestic vector mosquitoes, Aedes albopictus as a diurnal species and Culex pipiens as a nocturnal species, have correlation between reflecting luminous intensity of colors and preference for blood feeding activity. Laboratory evaluations were performed and the mosquito preferences were compared to three different color brightness such as light, primary, and dark for five fundamental color series including red, yellow, green, blue, and purple. The test bodies selected for these experiments were BioGents Sentinel traps (BG traps) with 20g dry ice in each falcon tube, which covered outside of the traps attached with three different luminous intensities such as light, primary, and dark for each different color of paper sheets. In each experiment, a pair of BG traps was placed 0.6 m away from each other in a 1.8 m x 3.7 m x 1.8 m screened enclosure. The enclosure maintained at 26±2℃, 65±5% RH, and 100 lux illumination. Evaluations were performed for two hours between 10:00 and 16:00 for each 25 Ae. ablopictus females and 15 hours from 18:00 to 9:00 for each 25 Cx. pipiens females. Each experiment was replicated four times. As a result, reflecting luminous intensity (L-value) affected and correlated negatively to the preference of the two mosquito species but the fundamental colors, green-red (a-value) and blue-yellow (b-value) were not correlated significantly to the preference (p=0.05). Aedes ablopictus females were preferred for feeding activity more to lower L-values of the colors and correlated negatively between color preference of the mosquitoes and the L-values such as r = -0.584 (p=0.003) for red, r = -0.606 (p=0.002) for yellow, r = -0.620 (p=0.001) for green, and r = -0.463 (p=0.023) for blue except purple (r = -0.129; p=0.549). Similarly, Cx. pipiens females were correlated negatively such as r = -0.590 (p=0.002) for red, r = -0.564 (p=0.005) for yellow, r = -0.687 (p=0.000) for green, r = -0.623 (p=0.001) for blue, and r = -0.689 (p=0.000). In conclusion, the color brightness were negatively correlated to the feeding activity of the two vector mosquito species but not the wavelength of visible ray. Also, the mosquito females preferred significantly darker ones in the same color series (p<0.05) except purple for Ae. ablopictus females.
        480.
        2018.10 구독 인증기관·개인회원 무료
        The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.