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        검색결과 216

        81.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present an ongoing study of the complete sample of supernova remnants (SNRs) and candidates in the Magellanic Clouds. 108 objects in both Clouds are considered to be either SNR or reliable candidates. This represents the most complete sample of all known SNRs in any galaxy. It therefore allows us to study SNR population properties such as the age-diameter (Age-D) relation. Here, we show that this Age-D relation is strongly dependant on the local environment in which SNRs are residing.
        4,000원
        82.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was carried out to assess the production performances of Japanese quail parent stock raised under open housing system and the study was conducted in a local farm with 2000 Japanese parent stock quail birds (Coturnix coturnix japonica). Observed body weight gain was recorded in each weekend up to 7 weeks of their age; birds gained weight 15.73, 31.45, 47.20, 90.80, 125.27, 153.14 and 175.20 grams, respectively. There have been observed sharp decline of fertility and hatchability of birds with increase of their age. Optimum fertility was recorded at third week and optimum hatchability at fifth week of their age. Average flock uniformity was found 83.68%. The hen day egg production of the flock was recorded 81, 83, 85, 86, 89, 89, 89, 89 and 88% in each weekend, respectively. It may therefore be concluded that Japanese quail parent stock performs well under open housing system in Bangladesh and future study can be taken to better understand their production performances.
        4,000원
        83.
        2015.06 구독 인증기관 무료, 개인회원 유료
        In the tanker industry, there are a lot of uncertain conditions that tanker companies have to deal with.For example, the global financial crisis and economic recession, the increase of bunker fuel prices and global climate change. Such conditions have forced tanker companies to change tankers speed from full speed to slow speed, extra slow speed and super slow speed. Due to such conditions, the objective of this paper is to present a methodology for determining vessel speeds of tankers that minimize the cost of the vessels under such conditions. The four levels of vessel speed in the tanker industry will be investigated and will incorporate a number of uncertain conditions. This will be done by developing a scientific model using a rule-based Bayesian reasoning method. The proposed model has produced 96 rules that can be used as guidance in the decision making process. Such results help tanker companies to determine the appropriate vessel speed to be used in a dynamic operational environmental.
        4,600원
        86.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 한국과 관련된 유교적 사상에 근거한 Fry (2003) 의 spiritual leadership**의 모델을 입증함과 동시에 한국의 금융 분야에서 직업의 불확실성에 직면한 고용인들과의 연관성 모델의 기반을 확립하기 위해 계획 되었다. Spiritual leadership은 leader, follower, 조직문화 및 직무성과의 관계를 요약한 새롭게 주목받는 전체론적 이론이다. 본 이론은 개인주의적인 문화와 연관된 서양에서 광범위하게 연구되어 져 온 반면, 한국과 같은 집단주의적 문화 안에서의 타당성은 최근 들어 연구되어 왔다. 게다가, spiritual leadership 과 관련된 기반산업 연구, 특히 직업 불확실성과 구조체계의 변화에 직면한 산업에 관한 연구 는 미미한 상태다. 본 연구는 spiritual leadership이라는 가치관의 출현과 더불어 구조 방정식 모델을 통해 소속감과 소명의식의 spiritual survival 변수에 의해 매개되어지는 조직몰입과 생산성과의 관계에 대해 살펴보았다. 통계자료는 한국의 강한 유교적 가치관을 지닌 한 금융회사에서 수집되었다. 본 연구의 결과는 참여자들이 높은 직업 불확실성에 직면있음에도 불구하고 Fry (2003)의 유교와 관련된 spiritual leadership 모델의 보편성을 잘 보여주었다. 신뢰도와 타당성지수는 적정수준 이상이었고 선행된 연구 결과의 범위 내에 있었다. 또한, NNFI와 CFI같은 부합지수는 1% 유의수준에서 모두 유의하였으며, 적정수준 (.95) 이상이었다. 따라서, 한국의 향후 금융분야의 조직연구의 기반이 될 것이다. 본 연구는 (a) spiritual leadership의 출현과 (b) spiritual leadership의 집단 차원의 분석과 관련된 유교의 긍정적인 면과 부정적인 면을 살펴봐야 할 필요성을 제안한다. 특히, 본 결과는 유교적 가치관이 공동 소속감을 통해 직무성과에 긍정적으로 기여되거나, leader와 follower들 간 상호 신뢰와 충성도에 따라 약한 권한부여를 통해 부정적으로 기여될 수 있음을 나타낸다. 더불어, 선행연구들과 비교하여 본연구의 spiritual leadership의 가치관의 낮은 평균 점수는 여러 다른 가능성들 중, 불확실성과 위기상황에서 leader와 follower의 잠재적인 관계 약화는 spiritual leadership의 강점을 뒤집을 수 있음을 제안한다. 또한, 향후 종단 연구을 통해 spiritual leadership에서 직무 불확실성의 관계를 보다 면밀히 살펴봐야 할 필요가 있다.
        6,100원
        87.
        2014.07 구독 인증기관·개인회원 무료
        This research examines the relationship between advertising expenditures and perceptions of popular brands by children and mothers in the United States. Findings how that magazine advertising has a positive and significant relationship with brand affinity scores to children and mothers while other advertising, such as electronic advertising and other print advertising, have negative or insignificant relationships with brand affinity scores. In addition, the correlation between exposure times through product/brand placement and brand affinity scores reveals a similar pattern. Product placement does not cause positive and significant relationships with brand affinity scores for either children or mothers.
        88.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Matrix Metalloproteinases (both MMP2 and -9) play a pivotal role of the embryos hatching and implantation. Therefore, the objective of this study was carried out to investigate the influence of MMP2 and MMP9 on embryo development potential and subsequent effect at molecular level. There was no significant difference of cleavage rate among the groups. The development competence of blastocyst was significantly higher (P<0.05) in MMP9 treatment (39.81±16.61) than that to the combined treatment of MMP2 and –9 (23.68±0.27), but there was no significant difference among the control vs. MMP2 vs. MMP9 (35.05±2.74 vs. 32.71±6.18 vs. 39.81±16.61, respectively). On the other hand, the hatching rate of blastocysts was significantly lower (P<0.05) in combined group of MMP2 and –9 (12.55±0.09) (Table1). The expression level of MMP2 and MMP9 was significantly lower (P<0.05) in the entire treatment groups than that in the control group. But the expression of MMP9 was significantly higher (P<0.05) when compared in the entire treatment groups. The relative expression embryonic developmental gene, IFNt expression level significantly lower (P < 0.05) in the MMP9 embryos. The placenta establishment genes, PLAC8 and SSLP1, expression were significantly higher (P < 0.05) in the MMP2 embryos compared to other groups. Transcription regulation gene, HNRNPA2B1, was higher (P < 0.05) in the combined group of MMP2+MMP9 than that in the other groups. In conclusion, our results suggest that MMPs to culture medium improves the blastocyst development rate and further impact on target gene expression analysis.
        4,000원
        89.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to know the in vitro effects of supplemental anthelmintic plant extracts on the inhibition of protozoa for reducing methane production in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The plant extracts (Lonicera japonica, Zanthoxylum piperitum, Pyrethrum, Torreya nucifera, Ruta graveolens) known to have anthelmintic effect were added to the in vitro fermentation bottles containing the rumen fluid and medium. The rumen protozoal population was depressed by the addition of Pyrethrum, Torreya nucifera and Ruta graveolens. The methane production was also significantly (p<0.05)reduced by addition of Pyrethrum (2.20 ml/g DM), Torreya nucifera (2.36 ml/g DM) and Ruta graveolens (2.20 ml/g DM). The microbial growth in the treatments of Ruta graveolens or anthoxylum piperitum was the greatest after 12 h and 24 h incubations, respectively. The results of this study indicated that anthelmintic plant extracts appeared to reduce methane production by inhibition of ruminal protozoa related with the methanogens living endosymbiotic in protozoal cells.
        4,000원
        90.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Matrix Metalloproteinases (MMP)-2 and -9 are participated in embryo development, implantation, remodeling of epithelial cell and ovulation. The objective of this study is to evaluate an impact of MMP2 and MMP9 on embryonic developmental competence as well as gene expression profiles of in vitro-produced bovine embryos. After in vitro fertilization, embryos of all groups were transferred into IVC-2 medium treated with MMP2 and MMP9 to check the optimum concentration on the basis of embryo development competence and cell numbers. The optimum concentrations for MMP2 and 9 were 1,200 ng/ml and 300 ng/ml. The blastocyst development competence was not different among 1,200 ng/ml of MMP2 vs. 300 ng/ml of MMP9 vs. combined MMP2 + 9 vs. control groups (41.46 ± 10.66 vs. 37.73 ± 8.92 vs. 45.11 ± 11.41% vs. 41.59 ± 11.88, respectively). Furthermore, the developmental competences to hatching and hatched blastocysts were not also different among the same groups (79.84 ± 12.63 vs. 83.3 ± 17.46 vs. 78.55 ± 14.48% vs. 72.02 ± 14.09). In addition, total cell number was significantly (p<0.05) greater in blastocyst treated with MMP9 300 ng/ml among all treatment groups. On the other hand, there was no significant difference of ICM vs. TE ratio in all groups. The expression of five out of six genes (i.e., MMP2, MMP9, IFNt, SSLP1 and HNRNPA2B1) was different among the groups. The expression of IFNt and HNRNPA2B1 genes was significantly greater in MMP9 (p<0.05), but there was no difference of MMP9 expression between MMP2 and MMP9 group (p>0.05). The normalized expression of MMP2 and SSLP1 was greater in MMP2 than other groups (p<0.05). In conclusion, MMPs treatment during IVC-2 medium was remarkably effected on blastocyst developmental competence and gene expression profiles that are related to embryo quality and implantation.
        4,000원
        91.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 양념 닭 가슴살의 양념 액에 귤 껍질 추출물(CPE, 2%), 양파 껍질 추출물(OPE, 2%), calcium lactate(2%), 난황 유래 phosvitin(0.1%)과 CPE, OPE 및 calcium lactate 복합처리를 첨가하였을 때 서로 다른 저장온도와 저장기간에 따른 항균 효과 및 품질 변화를 확인하고자 수행되었다. 모든 저장온도와 저장기간에서 CPE, OPE 및 복합 처리군의 총 호기성 세균 수는 대조구에 비해 유의적으로 낮게 확인되었으며, 가장 높은 미생물 생장 억제 효과가 있었던 처리군은 CPE 처리군이었다. 하지만, calcium lactate와 phosvitin 처리군의 미생물의 성장 억제 효과는 나타나지 않았다. pH의 경우, calcium lactate와 OPE 처리군은 모든 저장온도의 저장 0일차에서 대조구에 비해 유의적으로 낮은 값을 나타내었다. OPE 처리군은 모든 저장온도와 저장기간에서 다른 처리구들에 비해 유의적으로 높은 적색도를 나타내었고, CPE와 함께 저장온도에 따른 유의적 차이를 나타내지 않았다. 하지만 이러한 OPE 처리군은 풍미, 맛 및 종합적 기호도에서 다른 처리구들에 비해 유의적으로 낮은 값을 보였으며, calcium lactate와 phosvitin 처리군의 종합적 기호도는 대조구와 유의적 차이가 나타나지 않았다. 결론적으로, 양념 닭가슴살의 CPE, OPE 및 복합처리군에서 저장온도를 달리한 저장기간에 따른 미생물 억제 효과를 확인할 수 있었으나, 관능적 특성을 개선하는 방법의 개발이 필요하다고 판단된다.
        4,200원
        93.
        2014.04 구독 인증기관·개인회원 무료
        Teratocytes (TCs) are the cells derived from the embryonic serosal membrane of some parasitic hymenopteran insects. As a parasitic factor, TCs are multifunctional in host regulation by inducing nutritional, immune, and developmental alterations. However, little is understood about their genetic constituents. This study reveals a comprehensive view of the genes expressed by TCs through a transcriptome analysis based on RNAseq technology. More than 6.29 Gb sequences were used to assemble 34,686 contigs (>200 bp) and annotated into different functional categories. The TC transcriptome profile was clearly distinct from those of hemocytes and the fat body. The TC transcriptome contained components of insulin signaling and biosynthesis of juvenile hormone and 20-hydroxyecdysone. TCs also expressed various groups of digestive enzymes, supporting its nutritional role for the growing parasitoid larvae in parasitism. Furthermore, this transcriptome analysis annotated two kinds of immunosuppressive serine protease inhibitors (serpins) and Rho GTPase-activating proteins (RhoGAPs). To determine the biological functions of these factors, we devised ex vivo RNA interference (RNAi) by conducting knockdown of gene expression in in vitro cultured TCs followed by injection of the treated TCs to test insects. Ex vivo RNAi revealed that some serpins and RhoGAPs expressed in TCs inhibited host cellular immunity. This study reports a transcriptome of the unique TC animal cell, and its immunosuppressive genetic factors using ex vivo RNAi technology.
        96.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was attempted to new methods in mammalian embryos vitrification. This method was affected to increase of the embryo vitrification efficiency and it would be applied to the field of embryo transfer to recipient by modified loading method of embryo into 0.25 ml plastic straw. The frozen mouse embryos were carried out warmed from two different cell stages (8-cell and blastocyst, respectively) by attachment of an embryo in the vitrification straw (aV) method. All groups were cultured in M-16 medium to determine the development and survivability for 24 h, respectively. Results shown that, the survivability of two different groups were significantly different (94.8% vs. 70.9%). Total cell number was not significantly different the non-frozen blastocyst (99.7 ± 12.4) compared to the post-thaw blastocyst (94.8 ± 15.1). From the 8-cell embryo, total cell number of frozen blastocysts were significantly lower than others groups (74.7 ± 14.6, p<0.05). In the case of cell death analysis, the blastocysts from non-frozen and frozen-thawed 8-cell group were not different (0.0 ± 0.0 vs. 1.9 ± 3.1, p>0.05). However, the apoptotic nuclei of blastocyst were significantly observed the frozen-thawed group (5.4 ± 4.4) compared to non-frozen group (p<0.05). Therefore, this new method of embryos using in-straw dilution and direct transfer into other species would be more simple procedure of embryo transfer rather than step-wise dilution method and cryopreservation vessels, so we can be applied in animal as well as human embryo cryopreservation in further.
        4,000원
        97.
        2013.04 구독 인증기관·개인회원 무료
        Riptortus pedestris (F.) inflict losses on a wide range of crop plants. Biological control is an alternative approach to reduce the bean bug population. Scelionid Gryon japonicum (Ashmead) and Encyrtid Ooencyrtus nezarae Ishii are the major egg parasitoids of R. pedestris. The aggregation pheromone of R. pedestris serves as a kairomone to its egg parasitoids. A new tool was developed using aggregation pheromone in a trap which attracts both con-specific bugs and the parasitoids. Non viable host eggs were added with the trap so as to provide resource for the attracted parastioids to multiply. Several studies were conducted to develop this new tool for trapping of the bugs and enhancing parasitism simultaneously. Aggregation pheromone trap added with host eggs was found to increase temporal parasitism in field by 44% compared to the parasitism without host eggs. Higher parasitism (up to 91%) was found in the sites where aggregation pheromone trap added with host eggs was installed compared to control sites. In order to improve this tool, a new device with twelve sections to hold eggs and to be attached to the pheromone trap was designed to provide maximum exposure of the eggs to the parasitoids and to minimize the competition among the parasitoids. Parasitism and number of female R. pedestris trapped in new device attached trap were higher compared to the conventional. With better performance in trapping R. pedestris and enhancing parasitism, the tool would serve as an IPM technique that targets killing the pest and enhancing activity of the pest’s natural enemy simultaneously.
        99.
        2012.10 구독 인증기관·개인회원 무료
        An endoparasitoid wasp, Cotesia plutellae, parasitizes young larvae of the diamondback moth, Plutella xylostella, with its parasitic factors of polydnavirus, venom, ovarian proteins, and teratocytes (TC). TCs are originated from embryonic serosal membrane at hatch of C. plutellae eggs. TCs, after released in hemocoel of parasitized larvae, increased their average cell size from 20.6 μm to 77 μm during whole developmental period of the parasitoid larvae, but did not increase their cell number by maintaining about 150 cells per larvae. TCs of C. plutellae, are considered to be involved to extend the host larval development period and to arrest larval-pupal metamorphosis, were cultured in an insect cell culture medium for 21 days. Like TCs in parasitized larvae, in vitro cultured TCs showed increase in cell size, but did not show increase of cell number. Microinjection of in vitro cultured TCs significantly inhibited larva-to-pupa metamorphosis of nonparasitized P. xylostella, in which pupated host also showed extended larval period. Larvae injected with TCs exhibited alteration in expression of ecdysone receptor (EcR) and insulin receptor (InR) as well as in parasitized larvae. Teratocyte-secretory factors in culture medium showed this antimetamorphic effect on P. xylostella, while heat treated TC culture medium lost the effect. However, a successful parasitization of C. plutellae required both TCs and polydnavirus to alter host physiology.
        100.
        2012.10 구독 인증기관·개인회원 무료
        톱다리개미허리노린재(Riptortus pedestris [Fabricius] [Hemiptera: Alydidae])는 콩에서 특히 중요한 해충이다. 효과적 관리 전략 수립을 위해 톱다리개미허리노린재의 계절적 발생 패턴과 기주 식물의 먹이 적합성, 천적 기생벌들의 발생 소장과 상호관계에 대해 연구한 결과를 요약하였다. 톱다리개미허리노린재는 보리, 참께, 콩 등이 복합적으로 재배되는 전작지에서 모두 채집되었으나 콩에서 가장 밀도가 높았다. 콩 외의 작물은 실내 먹이실험에서 성충으로 발육하지 못하여 콩이 가장 주요한 먹이원임을 알 수 있었다. 한편 노린재검정알벌(Gryon japonicum [Ashmead] [Hymenoptera: Scelionidae])과 노린재깡충좀벌(Ooencyrtus nezarae Ishii [Hymenoptera: Encyrtidae])이 톱다리개미허리노린재의 주요 천적이며, 노린재검정알벌은 봄에서 초여름에 노린재깡충좀벌은 여름과 가을에 우점을 보인다. 이는 두 종이 경쟁적 배제를 통한 한 종의 멸종이 일어나지 않게 기주 자원을 시간적으로 분할한 결과로 보인다. 이러한 노린재와 기주식물(bottom-up) 그리고 천적(top-down)과의 상호관계의 이해를 통한 해충관리전략에 대해 고찰하였다.
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