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        검색결과 612

        221.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        There is much observational evidence that active star formation is taking place in the Hii regions Sh 2-255 – 257. We present a photometric study of this star forming region (SFR) using imaging data obtained in passbands from the optical to the mid-infrared, in order to study the star formation process. A total of 218 members were identified using various selection criteria based on their observational properties. The SFR is reddened by at least E(B −V ) = 0.8 mag, and the reddening law toward the region is normal (RV = 3.1). From the zero-age main sequence fitting method it is confirmed that the SFR is 2.1 ± 0.3 kpc from the Sun. The median age of the identified members is estimated to be about 1.3 Myr from a comparison of the Hertzsprung-Russell diagram (HRD) with stellar evolutionary models. The initial mass function (IMF) is derived from the HRD and the near-infrared (J, J −H) color-magnitude diagram. The slope of the IMF is about 􀀀 = −1.6 ± 0.1, which is slightly steeper than that of the Salpeter/Kroupa IMF. It implies that low-mass star formation is dominant in the SFR. The sum of the masses of all the identified members provides the lower limit of the cluster mass (169M⊙). We also analyzed the spectral energy distribution (SED) of pre-main sequence stars using the SED fitting tool of Robitaille et al., and confirm that there is a significant discrepancy between stellar mass and age obtained from two different methods based on the SED fitting tool and the HRD.
        4,500원
        222.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In Korea, yam with thermal treatment is widely used to produce tea and beverage, which appeals to all age groups. To better understand the antioxidative activity of thermal treatment yam (Dioscorea batatas DECNE.), n-butanol and ethyl acetate extracts were evaluated with different antioxidant testing system. Their antioxidant activities, including ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were assessed in vitro. Results showed ethyl acetate extract (51.63±2.51 mg CAE/g) possessed similar total phenol content compared with n-butanol extract (53.93±1.00 mg CAE/g). Ethyl acetate extract also exhibited similarly stronger antioxidant activity compared with n-butanol extract apart from ABTS radical scavenging activity assay.
        4,000원
        223.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas DECNE.) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Results showed ethyl acetate extract (111.88±0.66 mg CAE/g) possessed higher total phenol content than n-butanol extract (78.68±0.58 mg CAE/g). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.
        4,000원
        224.
        2015.12 구독 인증기관 무료, 개인회원 유료
        This study is aimed at analyzing social policy for unmarried single parents in Jeju Special Self- Governing Province, South Korea from 2005 to 2015 over 10 years by applying the policy analysis frame: dimensions of choice by Gilbert and Terrell(2013). The analysis result is as follows. First, the allocation dimension of who benefits has extended from selectivity of shelter-oriented service to universalism of community-based welfare services, which include not only unmarried mothers with their baby but also unmarried fathers with their baby. Second, social provisions have been enlarged and varied, ranging from simple shelter services to a multitude of services including shelter, voucher, cash, educational services, housing services and job training services etc. as shelter service changed into home-care service. Thirdly, the delivery system of social services for unmarried single parents has been changed from central governmental level through Jeju Special Provincial government to Jeju city government level. Research results found that all levels of government should reorganize and reform the service administration system for unmarried single parents, separated and specialized from family problems to meet the needs of a growing numberof single parents and various family types. Fourth, as financial resources of categorical grants from the central government to local government has been changed into block grants, financial deficit of local government can shake policy stability. That's why local communities should establish local ordinances to make all community social policy stable. Consequently, this policy analysis found that social welfare service for unmarried single parents has expanded but the financial resource limitation of local government can undermine the policy stability in the near future.
        5,400원
        225.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Iron is required for cell viability but is toxic in excess. While the iron-mediated malfunction of testicular cells is well appreciated, the underlying mechanism(s) of this effect and its relationship with fertility are poorly understood. Ferritin is a ubiquitous intracellular protein that controls iron storage, ferroxidase activity, immune response, and stress response in cells. Ferritin light chain protein (FTL) is the light subunit of the Ferritin. Previously, we had identified the FTL in bovine spermatozoa following capacitation. In present study, to investigate the role of Ferritin in sperm function, mice spermatozoa were incubated with multiple doses (1, 10 and 100 μM) of sodium nitroprusside (SNP), an iron donor. SNP was increased Ferritin levels in a dose-dependent manner. The Ferritin was detected on the acrosome in spermatozoa by immunocytochemistry. Short-term exposure of spermatozoa to SNP increased tyrosine phosphorylation and the acrosome reaction (AR). Finally, SNP affected a significant decrease in the rate of fertilization as well as blastocyst formation during early embryonic development. On the basis of these results, we propose that the effects of Ferritin on the AR may reduce overall sperm function leads to poor fertility in males and compromised embryonic development.
        4,000원
        226.
        2015.11 구독 인증기관·개인회원 무료
        The aim of this study was to analyze the genetic diversity of collected strains of Hypsizygus marmoreus based on their rDNA ITS sequences. The size of ITS rDNA regions of H. marmoreus strains, collected form various regions. A phylogenetic trees based on the ITS region revealed that the strains could be classified into 4 different groups including Villosiclava virens, Hypsizygus marmoreus, Lepista irina, Lyophyllum Decastes, Lyophyllum shimeji, Pleurotus floridanus.
        227.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report results of investigation of amplitude calibration for very long baseline interferome- try (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors are estimated based on comparison of KVN observations at 22 GHz correlated by Daejeon hardware correlator and DiFX software correlator in Korea Astronomy and Space Science Institute (KASI) with Very Long Base- line Array (VLBA) observations at 22 GHz by DiFX software correlator in National Radio Astronomy Observatory (NRAO). We used the observations for compact radio sources, 3C 454.3, NRAO 512, OJ 287, BL Lac, 3C 279, 1633+382, and 1510−089, which are almost unresolved for baselines in a range of 350-477 km. Visibility data of the sources obtained with similar baselines at KVN and VLBA are se- lected, fringe-fitted, calibrated, and compared for their amplitudes. We find that visibility amplitudes of KVN observations should be corrected by factors of 1.10 and 1.35 when correlated by DiFX and Daejeon correlators, respectively. These correction factors are attributed to the combination of two steps of 2-bit quantization in KVN observing systems and characteristics of Daejeon correlator.
        4,000원
        231.
        2015.10 구독 인증기관·개인회원 무료
        The Hawthorn spider mite Amphitetranychus viennensis is an important pest of various fruit trees as well as a variety of ornamental plants. Its presence has been reported in China, Japan, Korea, and middle east and European countries including Grorgia, Russia, Turkey, Ukraine. Thus, it is a quarantine species in American countries and Australia. Intra-specific variation of A. viennensis was investigated using 555 bp of ITS2 ribosomal DNA and 453 bp of the cytochrome oxidase I (COI) gene. Its variation of ITS2 and COI among China, Japan and Korea were 1.7-2.2% and 0.2-0.7%, respectively. In addition, we collected samples from 14 location in Korea. Intra-specific diversity of ITS2 and COI within Korean populations were ranged into 0.5-0.9% and 0.2-0.5%, respectively. Thus, A. viennensis is not much genetically diverse in different populations.
        232.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Milky Way did not form in isolation, but is the product of a complex evolution of generations of mergers, collapses, star formation, supernovae and collisional heating, radiative and collisional cooling, and ejected nucleosynthesis. Moreover, all of this occurs in the context of the cosmic expansion, the formation of cosmic laments, dark-matter haloes, spiral density waves, and emerging dark energy. This paper summarizes a review of recent attempts to reconstruct this complex evolution. We compare simulated properties with various observed properties of the Local Group. Among the generic features of simulated systems is the tendency for galactic halos to form within the dark matter filaments that define a super- galactic plane. Gravitational interaction along this structure leads to a streaming ow toward the two dominant galaxies in the cluster. We analyze this alignment and streaming flow and compare with the observed properties of Local-Group galaxies. Our comparison with Local Group properties suggests that some dwarf galaxies in the Local Group are part of a local streaming ow. These simulations also suggest that a significant fraction of the Galactic halo formed at large distances and arrived later along these streaming ows.
        3,000원
        233.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Total phenol contents, total flavonoid contents and antioxidant activity of 70% methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts from onion (Allium cepa L.) peels were studied. The IC50 values of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity in 70% ethanol extract were remained to be lowest followed by 70% methanol extract and CM extract. And the total phenol content (113.56±0.86 mg CAE/g), total flavonoid content (49.63 mg QE/g) and ferric reducing antioxidant power value were also found to be the highest. In contrast, 70% methanol extract possessed the strongest antioxidant activity by β-carotene bleaching assay. CM extract displayed the lowest antioxidant activity compared with other extracts. Onion peels exhibited strong antioxidant activity and abundant phytochemicals, which could be used in a various food products to add phytochemicals and promote good health.
        4,000원
        234.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas DECNE.) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity β-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.
        4,000원
        235.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bone fractures are most often seen in racetrack horses because of the high level of intensity in racing. These issues are the main cause of decreased performance in racehorses. Mesenchymal stem cells (MSCs) have been explored to improve intra-articular therapy in racehorses. MSCs are essential for the repair and regeneration of damaged tissues. In this study, the effect of intra-articular injection of MSCs in racehorses was investigated. Before accessing the MSC therapy, synovial fluids were obtained from the fracture site of racehorses, and adipose tissue was collected for MSC isolation. Using the MSC specific marker, adipose tissue-derived MSCs were identified. The racehorses received intra-articular injection of autologous MSCs (or allogeneic) (3 × 107 cells/3 mL). After 1 or 2 weeks, synovial fluids were collected from racehorses. To test the effect of MSC injection using ELISA, we analyzed inflammatory factors from the untreated samples compared to MSC-treated samples of racehorses. The level of pro-inflammatory factors (interleukin-1β and prostaglandin E2) was significantly decreased in synovial fluids of MSC-injected racehorses, compared to before accessing the MSC therapy, whereas, the level of anti-inflammatory factor (interleukin-10) was higher than prior to accessing the MSC therapy. Further studies are needed to investigate the anti-inflammatory mechanism of MSC in racehorses.
        4,000원
        239.
        2015.06 구독 인증기관·개인회원 무료
        Global depression has brought the Korean economy into the period of low growth. The notion of lifetime employment has long crumbled, while economic recession is gradually taking away quality jobs. Furthermore, the average lifespan for the population has neared 100, while baby-boomer retirement is swinging into high gear. The simultaneous inrush of social and economic problems is threatening our wellbeing. However, there has been insufficient amount of research conducted on the factors that influence the satisfaction with lectures in lifelong education designed to address the problems. If we look at the earlier studies, most of them are on the satisfaction with lectures in regular courses. Our society demands that jobs be created for retirees including the baby boomers and that quality jobs be provided for those who want to go back to work after they have withdrawn from previous employment. In this light, the current study aims to bring light on the causal relation between the influential factors and variables involved in the satisfaction of lectures of non-degree programs with a view to solving those problems, and suggests the need to draw up marketing strategy that uses it. Specifically, the purpose and method of this study are as follows. First, to develop variables to be used in this study through in-depth interviews with field staff in the industry and training staff. Second, to identify predisposing factors that influence the satisfaction with the lectures of non-degree programs. Third, to identify the variables mediating predisposing factors and satisfaction with lectures. Fourth, to propose marketing strategy for non-degree programs using the results of the study. As identified through this study, the influencing factors for satisfaction with lectures are physical environment, composition of contents, and instructor ability and attitude, while mediating variables are interaction and immersion in lectures. If these factors are reflected in education, a higher level of satisfaction with lectures will be ensured for business starting youths, retirees, and those who want to have some other job after withdrawing from their previous ones. Educational institutions will be able to use it in ensuring stabler recruiting of trainees and establish a more efficient guidance and marketing strategy. Reflecting the results of the study in education will contribute to heightening educational sustainability, social sustainability, and economic sustainability.
        240.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, n-butanol and ethyl acetate extracts were prepared from raw yam (Dioscorea batatas DECNE.). Their antioxidative potencies were investigated employing various in vitro methods, such as ferrous ion chelating, β-carotene bleaching assay, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging and nitrite scavenging activity. The n-butanol fraction was assayed to possess stronger antioxidant activity by β-carotene bleaching assay, lipid peroxidation inhibition and NO radical scavenging activity. However, ethyl acetate extract was more effective in chelating ferrous ion and scavenging nitrite. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.
        4,000원