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        검색결과 9,514

        7541.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        Purpose - Usage of E-services is critical for businesses to maximize work efficiency and gain competitive advantage. The aim of the study is to explore how awareness of technology and e-services usage in an emerging economy in Pakistan. The studies aimed to explore as to what extent these factors can potentially motivate transport employees towards e-services; who are generally not aware about technology and hence also not confident in using it also. Research design, data, and methodology - Employees from the three transport subsidiary units from a large private company in Pakistan were sampled for the study. Through using self-administered technique, the questionnaires were distributed during the month of April, 2016 to 189 employees. A total of 150 responses were taken further for analysis where the study found a positive link between awareness of technology and e-services usage. Results - This study found positive relationship between intention to use and e-service usage among the employees of three subsidiary units. The paper has reported 30 percent variance explained by the predicting variables in relation with e-services usage. Conclusions - Employees could be motivated to use e-services and latest technology through enhancing their awareness about their respective importance and viability. Accordingly, organizations can foster employees’ intentions to use to enhance e-service usage.
        7542.
        2016.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.
        7543.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        This study focused on the buildings, wharves, and parks of the coastal space of Chongqing based on the ten-year construction draft plan of the alternate capital. From an investigation of these three components according to their type, structure, terrain, function, spatial layer, and so on, the following conclusions were drawn: The coastal space of Chongqing is composed of three different layers. The first and second layers consisted of the two-river intersection basin with the transportation and commemorative space at the center, the Yangtze River basin with the commercial space at the center, and the Jialing River with the military and recreational space at the center. The third-layer is centered around the commemorative space. The coastal space of Chongqing manifested the limitations of the times, its traditionality, and an integrated development process.
        7544.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        Purpose - The aim of this article is to outline the concept of work engagement and the importance of job resources including supervisor support and coworker support pertaining to work engagement. Research Design, Data, and Methodology - The article discusses the concept of work engagement and what empirical evidences suggest about its relationship with job resources including supervisor and coworker support. Result - Critical review of the literature has indicated towards strengths and pitfalls of social support resources including supervisor and coworker at work, particularly with regards to work engagement thus, requiring further empirical attention. Accordingly, the article has also indicated towards the critical significance of meaningful work for fostering employee well-being at work. Conclusions - The article has highlighted noteworthy empirical gaps in the body of knowledge concerning to job resources including supervisor support and coworker support and their relationship with work engagement. The article has also underlined the lack of research and potential of ‘meaningful work’ towards enhancing work engagement as well as, acting as a moderator between supervisor support, coworker support and work engagement relationship.
        7545.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Understanding the genetic variation among landrace collections is important for crop improvement and utilization of valuable genetic resources. The present study was carried out to analyse the genetic diversity and associated population structure of 621 foxtail millet accessions of Korean landraces using 22 EST-SSR markers. A total of 121 alleles were detected from all accessions with an average of 5.5 alleles per microsatellite locus. The average values of gene diversity, polymorphism information content, and expected heterozygosity were 0.518, 0.594, and 0.034, respectively. Following the unweighted neighbor-joining method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 3 clusters, and population structure analysis also separated into 3 populations. Principal coordinate analysis (PCoA) explained a variation of 13.88% and 10.99% by first and second coordinates, respectively. However, in PCoA analysis, clear population-level clusters could not be found. This pattern of distribution might be the result of gene flow via germplasm exchanges in nearby regions. The results indicate that these Korean landraces of foxtail millet exhibit a moderate level of diversity. This study demonstrated that molecular marker strategies could contribute to a better understanding of the genetic structure in foxtail millet germplasm, and provides potentially useful information for developing conservation and breeding strategies.
        7546.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Sprouty (Spry) genes encode inhibitors of the receptor tyrosine kinase signaling cascade, which plays important roles in stem cells. However, the role of Spry4 in the stemness of embryonic stem cells has not been fully elucidated. Here, we used mouse embryonic stem cells (mESCs) as a model system to investigate the role of Spry4 in the stem cells. Suppression of Spry4 expression results in the decreases of cell proliferation, EB formation and stemness marker expression, suggesting that Spry4 activity is associated with stemness of mESCs. Teratoma assay showed that the cartilage maturation was facilitated in Spry4 knocked down mESCs. Our results suggest that Spry4 is an important regulator of the stemness and differentiation of mESCs.
        7547.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study describes results on sexual maturation and characteristics of natural spawned eggs to develop a method for the production of stable, healthy fertilized eggs from captive-reared yellowtail kingfish, Seriola lalandi. A total of 59 yellowtail kingfish were captured off the coast of Jeju Island, after which the broodstock was cultured in indoor culture tank (100 m3) until they were 6.1–14.9 kg in body weight. As part of the rearing management for induced sex maturation, the intensity of illumination was maintained at 130 lux. The photoperiod (light/dark; L/D) was set to a 12 L/12 D from October 2013 to January 2014, and 15 L/9 D from February 2014 to June 2014. Feeds comprised mainly EP (Extruded Pellets), with squid cuttlefish added for improvement of egg quality, and was given from April to June 2014. The first spawning of yellowtail kingfish occurred in May 3, 2014, at a water temperature of 17.0°C. Spawning continued until June 12, 2014, with the water temperature set at 20.5°C. Time of spawning was 26 times at this period. The total number of eggs that spawned during the spawning period was 4,449×103. The buoyant rate of spawning eggs and fertilization rate of buoyant eggs during the spawned period were 76.1% and 100%, respectively. The diameters of the egg and oil globule were 1.388 ± 0.041 mm and 0.378 ± 0.029 mm, respectively, which was higher in early eggs than in those from late during the spawned period.
        7548.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of 1.35 ± 0.04 mm and an oil globule diameter of 0.32 ± 0.02 mm. The fertilized eggs hatched 67–75 h after fertilization in water at 20 ± 0.5°C. The total length (TL) of the hatched larvae was 3.62 ± 0.16 mm. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was 4.72 ± 0.07 mm. At 40 DAH, the juveniles had grown to 30.44 ± 4.07 mm in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3–4 vertical stripes appeared. At 45 DAH, the juveniles were 38.67 ± 5.65 mm in TL and 10.10 ± 0.94 mm in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.
        7549.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Previously we observed that human adipose-derived stem cells (hADSCs) could form aggregation during culture in the presence of human serum (HS). In the present study, we have examined if the aggregation might result from the cell migration and analyzed the difference of cell adhesivity after culture in various conditions. When cells were cultured in fetal bovine serum (FBS) alone, there was no morphological change. Similarly, cells pretreated with FBS for 1 day or cultured in a mixture of FBS and HS showed little change. In contrast, cells cultured in HS alone exhibited formation of cell-free area (spacing) and/or cell aggregation. When cells cultured in FBS or pretreated with FBS were treated with 0.06% trypsin, almost cells remained attached to the dish surfaces. In contrast, when cells cultured in HS alone were examined, most cells detached from the dish by the same treatment. Treatment of cells with forskolin, isobutylmethyl xanthine (IBMX) or LY294002 inhibited the formation of spacing whereas H89 or Y27632 showed little effect. When these cells were treated with 0.06% trypsin after culture, most cells detached from the dishes as cells cultured in HS alone did. However, cells treated with IBMX exhibited weaker adhesivity than HS alone. Based on these observations, it is suggested that HS treatment might decrease the adhesivity and induce three-dimensional migration of hADSCs, in the latter of which cAMP signaling could be involved.
        7550.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.
        7551.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        The effect of sudden changes of water temperature (WT) on the survival rate and physiological responses of the red spotted grouper (Epinephelus akaara) were examined by manipulating WT control system for 9 days. Experimental condition was divided in two different regimes at low (from 10°C to 4°C, decreased 1℃/d) and high (from 28°C to 34°C, increased 1°C/d) WT. Survival rate of experimental fishes were observed, and determined the changes of hematological characteristics by analyzing plasma levels of cortisol, glucose, total protein, and electrolytes (Na+, Cl–, K+). No mortality was observed until low WT 6°C (144 h) and high WT 32°C (96 h), and 100% mortality was observed at low WT 4°C (216 h) and high WT 35°C (171 h). Plasma levels of cortisol and glucose increased rapidly as decreasing WT, and the loss of swimming ability and respiration response was observed at low WT 7°C and high WT 34°C conditions.
        7552.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was 23.0°C and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.
        7553.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        점토광물은 자연에서 쉽게 얻을 수 있고, 환경친화적이며 다양한 물리화학적 특성을 갖고 있어 인류 역사상 여러 분야에 활용되어 왔다. 최근에는 몬모릴로나이트, 카올리나이트, 세피올라이트, 금 속이중층수산화물과 같은 점토 화합물에 화학적 개질을 도입하여 산업분야에 활용하고자 하는 연구 가 활발히 진행되고 있다. 넓은 비표면적과 높은 측면비율, 나노수준의 입자 두께, 그리고 조절가능한 표면전하를 갖는 점토화합물에 화학적 개질을 적용하면, 고분자의 기계적 성질과 기체차단성을 개선 하고, 고분자 필름에 지속적 항균성을 부여하는 충전제로 사용할 수 있다. 또한, 개질된 점토화합물은 높은 흡착능과 화학적 선택성을 지니므로, 수질이나 토양을 오염시키는 화학적, 생물학적 오염원을 효 과적으로 제거하는 물질로도 활용 가능하다. 본 논평에서는 이러한 점토화합물들이 미래의 주요산업 군인 식품포장재 및 환경개선 분야에 활용될 가능성에 대해 최근 연구 결과를 소개하고자 한다.
        7554.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Purpose – The purpose of this paper is to review, analyze and identify the suitability of Kazakh gender policy for the changes taken place in the society with suggesting necessary changes. Research design, data, and methodology – After meticulous reviews of germane literature, the researchers applied an analytical approach which focuses on analyzing the Kazakh’s gender policy and its issuance guidelines based on the present requirement in the society. Even though the policy has introduced with astonishing prudence, present-day living trends in society require imperatively some notable modifications which protect the rights of women and minority sections of the society. Results – Through this gender policy, government has proffered required legal, financial and preferential support country’s women to participate in the management and legislation of the country. Kazakh gender policy requires upgradations which flawlessly support women in the lifestyles of the feminine community. Conclusions – In achieving gender equality in the economy as a priority area, Kazakh government monitoring persistently and closely the changing trends of women and their requirements which introduce necessary modifications to the existing gender policy of the country with the cooperation of international organization.
        7555.
        2016.06 서비스 종료(열람 제한)
        The definitions of international authorized probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The scientific basis for the prevention and treatment of bowel disease among the functions of probiotics has only recently been established. Probiotics, which are actively studied, are lactic acid bacteria, especially Lactobacillus and Bifidobacterium species. The C. difficile toxin is controlled by quorum sensing, which causes intestinal disease and other gastrointestinal disorders, leading to antibiotic-associated diarrhea. The use of probiotics for prevention and treatment has been discussed in this review.
        7556.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The correlation between meteorological data collected at the optical wide-field patrol network (OWL-Net) Station No. 1 and the seeing of satellite optical observation data was analyzed. Meteorological data and satellite optical observation data from June 2014 to November 2015 were analyzed. The analyzed meteorological data were the outdoor air temperature, relative humidity, wind speed, and cloud index data, and the analyzed satellite optical observation data were the seeing full-width at half-maximum (FWHM) data. The annual meteorological pattern for Mongolia was analyzed by collecting meteorological data over four seasons, with data collection beginning after the installation and initial set-up of the OWL-Net Station No. 1 in Mongolia. A comparison of the meteorological data and the seeing of the satellite optical observation data showed that the seeing degrades as the wind strength increases and as the cloud cover decreases. This finding is explained by the bias effect, which is caused by the fact that the number of images taken on the less cloudy days was relatively small. The seeing FWHM showed no clear correlation with either temperature or relative humidity.
        7557.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.
        7558.
        2016.05 서비스 종료(열람 제한)
        Background : The purpose of the present investigation is to enhance extracellular acidic protease production by subjecting a protease producing strain Cordyceps pruinosa DK-01 to random mutagenesis by UV irradiation after ethidium bromide treatment. Methods and Results : Mutants were screened as protease producers on the basis of zone of clearance and relative proteolytic activity (RPA) on skimmed milk agar plates. In addition, mutants showed strong pink-red color intensity and different RAPD profiling compared with wild type control. Four mutants were randomly selected and their extracellular enzyme activities were investigated. In liquid culture without casein, 2.2-, 2.9-, 5.2- and 4.4-fold higher acid protease activity was achieved from mutants DK-m9, -m11 and -m12, respectively, than that of wild type strain (11.13 ± 1.60 U/ml). In liquid culture with casein, 1.1-, 1.3-, 1.3 and 1.3-fold higher acid protease activity was achieved with those mutants were found to produce, respectively, than that of wild type strain (93.95 ± 12.84 U/ml). Maximum acid protease activity was noticed from a mutant DK-m11 in liquid culture with casein (121.18 U/ml) and without casein (57.65 U/ml). The extracellular acid protease produced from DJ-m11 that was active in the pH range 4.5-6.5 and optimum temperature for the activity was 37°C. Furthermore, we found a deformed, shorten structure of setae on the elytron surface of dynastid beetles treated with culture supernatant of the DK-m11. Conclusion : These findings have more impact on enzyme economy for biotechnological and insecticidal applications of fungal proteases.
        7559.
        2016.05 서비스 종료(열람 제한)
        Background : With the increasing demand of the mistletoe in larger quantities for cancer therapy, it has been depleted from its natural habitat in the Far East countries including Korea because of overharvesting for high-value products (e.g., lectins and viscotoxins). The rapid multiplication of mistletoe by tissue culture can help this problem and provide the benefits in the phamaceutical industry. Methods and Results : Mistletoe plants growing on oak trees were collected and their leaf and stem segments were inoculated on MS basal medium supplemented with various concentrations of growth regulators. Calli were induced only from stem explants on MS medium containing 2,4-D and transferred onto MS medium supplemented with various concentrations of 2,4-D, NAA and BAP, respectively, for their propagation. The best callus multiplication rate of more than 15 folds (759 mg) was obtained in treatment of 2,4-D (4 mg/L) that produced yellowish-green, white and friable callus on this medium. To compare biochemical characterization, lectins were partially purified from natural mistletoe plants (nML) and in vitro cultured mistletoe calli (cML), respectively. The former was purified by lactose-agarose affinity chromatography and the latter was done by ammonium sulfate precipitation followed Sephadex G-25 chromatography. Both nML and cML showed similar molecular weight on SDS-PAGE and Western blot analyses. In addition, they showed similar carbohydrate-binding specificities and hemagglutination activities. Conclusion : From the above results, we may suggest that nML and cML showed the similarity in biochemical characters.
        7560.
        2016.05 서비스 종료(열람 제한)
        Background : Lectins were individually isolated from natural Korean mistletoe (nML) and its in vitro cultured calli (cML). Both of the lectins showed the difference in bioactivities such as cytotoxicity and cytokine induction. Methods and Results : Target cells (1 x 104 cells/well) were seeded independently into each well of a 96-well culture plate and incubated with different concentrations of each lectin. Survivability of target cells was determined by CCK-8 kit (Sigma, USA) according to manufacturer’s directions. The nML showed 46, 34 and 5.5 times stronger than cML in cytotoxicity (IC50) to human melanoma cell line (SK-MEL-28), human carcinoma cell line (NCI-H1650) and murine macrophage (RAW 264.7), respectively. In addition, respective lectins directly stimulated macrophage RAW 264.7 but they showed the difference in enhanced productivity of some inflammatory cytokines. Compared with cML, the nML induced both TNF-α and IL-1β at its low concentration. Administration of two kinds of lectins (10-1000 μ g/kg body weight) to ICR mouse did not show any significant changes on the level of alanine transaminase (ALT), glutamate-oxaloacetic transaminase (GOT) and blood urea nitrogen (BUN) in sera. Conclusion : From the above results, we may suggest that nML and cML showed differences in cytotoxic effects and cytokine production due to the difference in amounts from sources.