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        검색결과 154

        101.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to compare the efficacy of cryopreservation methods for ex situ conservation of spermatozoa from far eastern catfish, Silurus asotus. The spermatozoa activity index (SAI) and hatching rates were higher in spermatozoa stored in Alserver’s solution than those of spermatozoa stored in glucose solution. The SAI and hatching rates in all experimental groups gradually decreased with increasing duration of storage. Additionally, the SAI and hatching rates gradually decreased with increasing thawing temperatures at all storage durations (P<0.05). Based on the SAI and hatching rates, our results suggest that the optimal cryopreservation conditions of catfish spermatozoa involve storage in Alserver’s so-lution with 15% ethylene glycol, and thawing at 25℃. Cryopreservation of spermatozoa is a useful and reliable technique for conserving gene resources and for artificial propagation of far eastern catfish.
        102.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were L∞=30.2 mm, K=3.22/year, and τ0=-0.05. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka.
        103.
        2016.10 서비스 종료(열람 제한)
        Background : Constipation is can refer to bowel movements that are rare or hard for pass. Constipation is common symptom in current people and the treatment of constipation focused on the use of medicines or physical intervention. The aim of this study are investigates the effects of modified-extracts of Salicornia herbacea (S. herbacea) L. on constipation model. Methods and Results : To investigate the effect of these extracts on constipation model with Sprague-Dawley rats by loperamide administration, we orally administered various dosage of modified-extracts of S. herbacea. L. Then, we checked constipation-related parameters such as fecal number, colon weight, colonic transmit length, colon length as compared to the controls and ameliorated in a dose dependent manner. The results indicated that modified-extracts of S. herbacea. L. was ameliorated constipation in SD rat model. Conclusion : Based on the results, modified-extracts of S. herbacea L. and its many ingredients were considered to have effects on constipation.
        104.
        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.
        105.
        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.
        106.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaara and the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred μg/kg of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder (2×2×2 m). Eggs were colorless transparent free pelagic eggs, 0.71–0.77 mm large (mean 0.74±0.02 mm, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02–2.17 mm in total length (mean 2.10±0.11 mm), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88–4.07 mm in total length (mean 3.98±0.13 mm), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9–35.2 mm in total length (mean 33.6±2.33 mm), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish.
        107.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Safflower (Carthamus tinctorius L.) seeds have long been clinically used in Korea to promote bone formation and prevent osteoporosis. In addition, the safflower buds (SB) were found to have more useful functional ingredients than safflower seed. Thus, we investigated the preventive effects of SB diet in ovariectomized (OVX) rats. The rats were divided into five groups; sham operated group, OVX alone group, OVX plus 17β-estradiol (E2 10 ㎍/㎏, i.p.) and OVX plus SB diet feeding group (0.3% or 1%). Feeding of SB diet (0.3% or 3%) to OVX rats markedly increased trabecular formation in femur compared to OVX rats. Feeding of SB diet (0.3% or 3%) to OVX rats also decreased TRAP activity compared to OVX rats. These results suggest that SB diets have bone sparing effects by the decrease of osteoclast activity. We also observed that OVX rats fed with SB diet (0.3% or 3%) exhibited the decrease of calcium and phosphorus in serum compared to OVX-induced rats. Therefore, SB may be beneficial for the patients of osteoporosis, especially in postmenopausal women.
        108.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Several optical monitoring strategies by a ground-based telescope to protect a Geostationary Earth Orbit (GEO) satellite from collisions with close approaching objects were investigated. Geostationary Transfer Orbit (GTO) objects, Inclined GeoSynchronous Orbit (IGSO) objects, and drifted GEO objects forced by natural perturbations are hazardous to operational GEO satellites regarding issues related to close approaches. The status of these objects was analyzed on the basis of their orbital characteristics in Two-Line Element (TLE) data from the Joint Space Operation Center (JSpOC). We confirmed the conjunction probability with all catalogued objects for the domestic operational GEO satellite, Communication, Ocean and Meteorological Satellite (COMS) using the Conjunction Analysis Tools by Analytical Graphics, Inc (AGI). The longitudinal drift rates of GeoSynchronous Orbit (GSO) objects were calculated, with an analytic method and they were confirmed using the Systems Tool Kit by AGI. The required monitoring area was determined from the expected drift duration and inclination of the simulated target. The optical monitoring strategy for the target area was analyzed through the orbit determination accuracy. For this purpose, the close approach of Russian satellite Raduga 1-7 to Korean COMS in 2011 was selected.
        109.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        As a governmentally approved domestic entity for Space Situational Awareness, Korea Astronomy and Space Science Institute (KASI) is developing and operating an optical telescopes system, Optical Wide-field PatroL (OWL) Network. During the test phase of this system, it is necessary to determine the range of brightness of the observable satellites. We have defined standard magnitude for Low Earth Orbit (LEO) satellites to calibrate their luminosity in terms of standard parameters such as distance, phase angle, and angular rate. In this work, we report the optical brightness range of five LEO Satellites using OWL-Net.
        110.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate effects of chopped and non-chopped rice straw on characteristics of silage-basedtotal mixed ration (TMR) according to the particle size, laceration, and in situ dry matter (DM) degradation. The threerice straw silages as low moisture unchopped (LMUC; 32.75% of moisture, unchopped), high moisture unchopped(HMUC; 42.05% of moisture, unchopped), and high moisture chopped (HMC; 44.71% of moisture, chopped to 30cmlengths) were tested. Samples were collected at every 5 minutes from 10 min of pre-mixing to 50 min. The percentageof >19mm in LMUC and HMC was decreased to 7.23% and 7.74% (p<0.05), respectively, and the percentage of 8mm>was increased to 5.81% and 5.24%, respectively. Furthermore, the laceration of forage by a TMR mixer showed that therewas little change in the reduction of 1.26% in HMC, but was reduced to 7.53% and 16.06% in LMUC and HMUC,respectively. The peNDF>8 was maintained 17~18.5% of the optimal requirement level for 15 to 45 min mixing in LMUCand for 30 to 50 min mixing in HMC, but it exceeded the level of peNDF>8 in the range of 21.49 to 22.53% for 50minmixing in HMUC. However, ruminal in situ DM degradation appeared as LMUC>HMUC>HMC. Therefore, theseresults suggest that the rice straw silage may be useful for high-yielding lactating cows, if it can be supplied with theadequate peNDF, and the limiting factor on DMI and DM degradation was reduced by crushing of the plant tissue, althoughthe rice straw silage was concerned to low quality forage.
        111.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        The influence of triploidization on cell and nucleus size characteristics of the same tissues of erythrocyte, retina, kidney, hepatocyte and midgut epithelium in marine medaka, Oryzias dancena has been determined histologically. Induced triploid fish are produced by cold shock treatments. Likewise, the size of horizontal cell nucleus in inner nuclear layer of retina, ganglion cell nucleus in ganglion cell layer of retina, proximal tubule cell of kidney, hepatocytes and nuclear height of midgut epithelium all appear to be significantly larger than diploid (P<0.05). On the other hand, retina thickness is larger in diploid than induced triploid (P<0.05). Induced triploid shows low density of cell number. Results of this study suggest that same characteristics in the induced triploid exhibiting larger cells and nucleus sizes with fewer number of cells than the diploid can be useful criteria for the distinction between diploid and induced triploid, and also the ploidy level in marine medaka.
        112.
        2015.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of “action”, and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.
        113.
        2015.07 서비스 종료(열람 제한)
        Soybean (Glycine max (L.) Merr) is a short day plant and has been adapted to various climates and environments during cultivation. However, the cultivation area is restricted to a very narrow range of latitudes. To date, nine major genes (E1 to E8 and J) have been reported to control the flowering time and maturity. Here, we evaluated the role of E2, E3, E4, and their paralogue genes in late flowering soybean cultivars under long day (LD) conditions using Soybean yellow common mosaic virus (SYCMV)-based virus-induced gene silencing (VIGS) system. A total of nine VIGS constructs were infiltrated into two fully expanded cotyledons and primary leaves. After inoculation with these VIGS constructs on Jangyeobkong, which is a late-flowering cultivar, phenotypic traits were evaluated for the first flowering dates (FFDs) and pod maturities under LD conditions. The FFDs of the silenced plants occurred 50-56 days after sowing (das), while the non-silenced plants bloomed on 60-61 days. We found that the E3 paralogue-silenced plants flowered the fastest and responsive genes were identified to be associated with the promotion of flowering time. As the knock-down of E3 paralogue, expression of E1 was up-regulated, E2 was no difference, E3 and E4 genes were down-regulated in the silenced plants. Expression of GmFT2a and GmFT5a is known to be controlled by E3 and E4. Interestingly, GmFT5a were highly expressed in SYCMV:E3 paralogue-silenced plants, whereas the expression of GmFT2a was not significant. These results support that GmFT5a is able to independently promote flowering under LD conditions.
        114.
        2014.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        A prototype of the GMT FSM has been developed to acquire and to enhance the key technology – mirror fabrication and tiptilt actuation. The ellipsoidal off-axis mirror has been designed, analyzed, and fabricated from light-weighting to grinding, polishing, and figuring of the mirror surface. The mirror was tested by using an interferometer together with CGHs, which revealed the surface error of 13.7 nm rms in the diameter of 1030 mm. The SCOTS test was employed to independently validate the test results. It measured the surface error to be 17.4 nm rms in the diameter of 1010 mm. Both tests show the optical surface of the FSMP mirror within the required value of 20 nm rms surface error.
        115.
        2014.09 서비스 종료(열람 제한)
        The histological changes in the Ussurian bullhead, Leiocassis ussuriensis, and the Korean bullhead, Pseudobagrus fulvidraco, were observed during the early period of growth. The retinas size of both species increased in the 9 days post-hatching (DPH) (P<0.05). In the just-hatched Ussurian bullhead, the retina already consisted of six layers: the epithelial layer, ganglion cell layer, inner nuclear layer, inner plexiform layer, outer limiting membrane layer, and rod and cone layer. The Korean bullhead had the same components. At 50 DPH, the thickness of the retina was 538.0±7.19 μm in the Ussurian bullhead and 558.9±9.44 μm in the Korean bullhead. The relative thickness of each layer of the retina did not differ significantly in the two species. Although the growth of the Korean bullhead’s retina was faster, the relative thickness of each layer in the retina did not change during early development. After hatching, some parts of the tissue gradually became denser. Immediately after hatching, the kidney and midgut epithelium of the Ussurian bullhead and Korean bullhead were already formed and grew gradually thereafter. From 0 DPH to 30 DPH, the nuclear height in the midgut epithelium did not differ significantly between the two species, but at 50 DPH, it was 11.4±2.45 μm in the Korean bullhead and 9.9±2.13 μm in the Ussurian bullhead. During the experimental period, the major axes, minor axes, surface areas, and volumes of the proximal tubule cells in the kidney did not differ significantly between the two species. Thus, the early histological development of the Ussurian bullhead is similar to that of the Korean bullhead.
        117.
        2014.07 서비스 종료(열람 제한)
        Anthocyanins are very important constituent of human diet. In recent years, they have gained much attention due to their antioxidative properties. As the radish (Raphanus sativus L) has rich content of anthocyanins, the study is aimed to develop increased functional radish from selected radish varieties. ‘Bordeux’ is a hybrid variety of breeding between one accession derived from ‘Oharu’ as a maternal variety and ‘Chungpihongsim’ as a paternal variety. In this study, we investigated the new varieties of radish commonly consumed in Republic of Korea for their total phenolic content (TPC) and antioxidant activities using three (DDPH, FRAP and CUPRAC) different assays. The selected radish varieties like ‘Bordeux’, ‘Chungbok’, ‘3209’, ‘Chungwoon’, ‘Oharu’, and ‘Chungpihongsim’ were procured from the company Syngenta Korea. Among the selected radish varieties, ‘Bordeux’ (289 μg/g FW) and ‘Chungpihongsim’ (276 μg/g FW) revealed maximum amount of phenolics; whereas ‘3209’ (103 μg/g FW) and ‘Chungwoon’ (166 μg/g FW) showed the lower amount of phenolics content, respectively. Extracts from these studied radishes showed good to moderate antioxidant activities. The varieties ‘Chungpihongsim’ and ‘Bordeux’ revealed maximum antioxidant activity for all assays as demonstrated. However, some varieties like ‘3209’ and ‘Oharu’ exhibited the lowest antioxidant activity in all the tested assays, viz; DPH, FRAP and CUPRAC in μg TE/g FW, respectively. The antioxidant activities may be attributed to the higher phenolic acid contents as a linear relation was observed between the two components and the antioxidant parameters.
        118.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        Recently, brand equity is paid much attention in various industries. However, container liner shipping companies are still unfamiliar with this concept, and also the brand equity model has not been tested yet in shipping context. This study, therefore, aims to measure the relative importance of brand equity factors of container liner shipping companies by employing AHP (Analytic Hierarchy Process). This study concludes that perceived quality, in particular cost-related service quality, is the most influential factor of brand equity, while weak support is found for brand association. In addition to this, group comparisons were conducted between shipping companies, freight forwarders and academics. The results will be useful as they firstly define brand equity and its role in shipping context, highlighting the significance of brand management to container liner shipping firms. This evaluation is not an end in itself, but will eventually be utilised as a tool to build competitive advantage which cannot be easily imitated by competitors.
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