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        검색결과 151

        81.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The recovery of epididymal sperm in animals is considered as one of the important tools to preserve high value or endangered species. However, there are no appropriate castrating indicators such as months of age in bull, sperm morphology, and motility, particularly in young Korean native bull (Hanwoo). Therefore, this study aimed to investigate sperm number, morphology, and motility of sperm in the epididymis tail of young Hanwoo bulls at 8 and 15 months of age. After castration, epididymal tails were collected and minced with blades to recover sperm. In experiments 1 and 2, sperm number, morphology, and motility were examined. Total number of sperm and percentage of normal sperm from bulls at 8 months of age was lower than that of bulls at 15 months of age after collection (P<0.05). Percentage of abnormal head, tail, proximal cytoplasmic droplet, dead and damaged acrosome of sperm from bulls at 8 months of age were higher than those of bulls at 15 months of age (P<0.05). In experiment 3, sperm motility from bulls at 8 and 15 months of age were examined before freezing and after thawing. Frozen-thawed sperm at 8 months of age showed low total motility and motile sperm with ≥ 25 μm/sec compared to those at 15 months of age and commercially-used sperm (P<0.05). In conclusion, sperm derived from the epididymal tail of bulls at 8 months of age showed high abnormal morphology and poor motility, which are not adequate for AI and IVF. On the other hand, sperm derived from the epididymal tail of bulls at 15 months of age showed high normal morphology and motility.
        4,000원
        82.
        2016.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a numerical experiment on a tidal turbine was performed based on a water wheel design using the commercial CFD code ANSYS-CFX to contribute to the development of water wheels. The water wheel type tidal turbine was studied with different numbers of rotor blades (including ten, twelve and twenty blades types) and with different blade shapes (Straight, Curved and Zuppinger types) for comparison at several values of tip speed ratio (TSR) ranging from 0.7 to 1.2. The numerical results indicated that the 10-bladed type and the Straight-bladed type turbines absorb the highest power efficiency, up to 43 % at TSR 0.9. In addition, the 20-bladed and the Curved-bladed types showed the lowest performances in all cases of TSRs comparing with the others. Besides that, it was found that this turbine operates much effectively at low range of TSR, especially at TSRs 0.9 and 1 for all cases of blade shapes and all numbers of blades.
        4,000원
        83.
        2016.04 구독 인증기관·개인회원 무료
        Western flower thrips, (Pergande) (Thysanoptera: Thripidae) have been recognized as serious pests worldwide. Commercially available chemical pesticides challenges against the resistance of the pest and safety to consumers. Herein we investigated the usability of soil-treatment of entomopathogenic Beauveria bassiana (Bb) ERL isolates in tomatoes. Bb-egfp was highly virulent to western flower thrips in laboratory conditions and colonized in soil, which provided a chance for western flower thrips larvae to contact the colonized fungal mass. In a glasshouse trial, Bb ERL836 and Bb ERL1578 granule (GR) were applied to soil surface and mixed well, and five females were infested to each pot of tomato 3 days after the application. The two treatments significantly reduced thrips population in tomatoes 20 and 40 days post applications, comparable to the control efficacy of clothianidin granule (GR) formulation. In the following field trial, the two ERL fungal treatments showed 69.2% and 61.5% of control efficacy, which were similar to that of clothianidin GR (76.9%). This work suggests that applied B. bassiana colonized in soil well and thrips larvae easily contacted the fungal mass, which possibly enabled the control strategy to be alternative way to the chemical control.
        84.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study investigated the effects of adding bovine plasma protein(PP) hydrolysates on the quality properties of cooked pork patties. Pork patties were prepared as follows: manufactured with pork back-fat(control); replacement of back-fat with 40% olive oil(T1), 40% olive oil and 2% PP hydrolysates(T2), and 40% olive oil and 4% PP hydrolysates(T3). The olive oil modified the fatty acid profiles of the pork patties by lowering the saturated fatty acids(SFAs) percentage. Olive oil and 4% PP hydrolysates addition reduced the level of 2-thiobarbituric acid-reactive substance(TBARS) values in pork patties, compared to the controls. Furthermore, the pork patties with added PP hydrolysates had higher pH values than the control. All samples containing olive oil and PP hydrolysates had increased levels of DPPH radical scavenging activity. In particular, added PP hydrolysates were more effective in increasing antioxidant activity than were the other treatments. Therefore, PP hydrolysates could be used as a natural antioxidative in cooked pork patties.
        4,200원
        87.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the interrelationship of weight and hormonal changes through the administration of vitamin A to first time pregnant heifers. A total of 28 Korean heifers was used for this study. The heifers were divided into two groups - with vitamin A (n=14) and without vitamin A (control) (n=14) in the feed. Body weight increased in vitamin A treated heifers starting 9 months until 15 months. After pregnancy, vitamin A treated heifers were found to maintain higher body weights than the control group. Pre-pregnancy and post pregnancy progesterone levels were not different between the two groups. Serum estradiol levels of heifers at different growth stages showed relatively higher E2 levels than the control. Also, the control during pregnancy may show higher serum E2 levels than the vitamin A treated heifers. The growth phase serum estradiol levels in heifers may be relatively higher than the control. During pregnancy it showed a similar trend. Serum levels of vitamin A treated heifers did not differ from pregnant heifers at 5 months of age. However, after 5 months from conception until 8 months of treatment it showed a high level. Serum cholesterol in pregnant cows was higher in the control group than the treatment from beginning until the end of pregnancy. This is considered to be related to fetus development during pregnancy, as well as the mother's health.
        4,000원
        88.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was performed on farm animals to test the effectiveness of progesterone-releasing intravaginal device (Cue-Mate® 1.56 g) and injection of prostaglandin F2α (PGF2α) for synchronization estrus in Hanwoo cattle. The cattle were at random stage of the estrus cycle. The cows were artificially inseminated at day 7 after Cue-Mate withdrawal, using commercial semen from Korean native bulls. There was a season effect on the estrus synchronization rate. It was higher in spring (94.3%) followed by winter (93.3%), autumn (90.4%) and summer (67.2%). In summary, The results of this study revealed that season has influences on estrus behavior of cattle with no significant effect on pregnancy rate. In summary, we suggest summer reproductive management to alleviate the effects of heat stress. It should be based on intensive cooling combined with hormonal treatment. Given that different subgroups of cows benefit differently from the treatments, selective hormonal administration should be considered.
        4,000원
        89.
        2014.09 구독 인증기관 무료, 개인회원 유료
        Pruritus is one of the most important symptoms of allergic inflammatory skin disease. Conjugated linoleic acid (CLA) has been reported to have preventive effects against allergic inflammation. The objective of this study was to determine whether or not oral administration of CLA suppresses pruritus induced by compound 48/80 (composed of N-methyl-p-methoxy phenethylamine with formaldehyde) in mice, and if so, whether or not this effect is associated with serum histamine and prostaglandin (PG) E2 levels. Liquid CLA mixture (36.25% 9c-11t CLA, 36.95% 10t-12c CLA, 1.12% 9c-11c, and 1.94% t9-t11 CLA) was emulsified in 0.5% carboxymethyl cellulose (CMC) sodium salt and orally administered to mice at doses of 200 mg/kg once per day for 3 days. Similarly, disodium chromoglycate (DSCG), an antipruritic substance, was administered orally at the same concentrations as the negative control. Compound 48/80, a pruritus-inducing reagent, was subcutaneously injected 30 minutes after final administration of CLA. Scratching behavior of mice was counted just after compound 48/80 injection. Serum histamine and PGE2 concentrations were evaluated individually. Mice administered with CLA showed reduced frequency of scratching behavior compared to those without CLA. Antipruritic activities in CLA-treated and DSCG-treated groups were 48.5% and 26.8%, respectively. CLA and DSCG also diminished serum concentrations of histamine and PGE2 compared to compound 48/80 alone, respectively. This result suggests that dietary CLA has an antipruritic effect by down-regulating serum histamine and PGE2 levels for relief of compound 48/80-induced scratching behavior in mice, which will be useful in allergic pruritus as a preventive medicine.
        4,000원
        90.
        2014.04 구독 인증기관 무료, 개인회원 유료
        Islanders have tried to find out real alternatives on how to keep sustainable Haenyeo communities through both developing traditional school system at community level (Hansupul Haenyeos School) and advanced school system at university level ( an educational certificate program for Interpreter of Haenyeos Culture and an advanced certificate program for Hanyeos Culture). In oder to share their wisdom of ordinary democratic life style around Bultuk, We created Global Peace Bultuk Assembly for younger generation to succeed in their tradition in July of 2010. It' s a time for us to find out Integrating Policy of the Sustainability of Jeju Haenyeo (Jamnyeo, Jamsu) Community facing their extinction into Jeju Village Conservation Model of Marine Resources Needed.
        5,400원
        91.
        2014.04 구독 인증기관·개인회원 무료
        Anatatus orientalis is an important natural enemy parasitizing eggs of lanternfly Lycorma delicatula White. In order to effectively utilize this parasitoid, the parasitism rates of lantern-fly and emergence of its parasitoid were surveyed in different areas. Results showed that the emergences of wasp Anatatus orientalis from different areas had significant differences. Those parasitoids emerged from lantern-fly eggs collected from Yangling of Shaanxi province, Qinhuangdao of Hebei province, and Dagang District of Tianjin City came out focus on May only, while wasps from Yantai of Shandong province showed 2 obvious emergence peaks in May and September respectively. Wasp populations with emergence asynchrony in Yantai area were analyzed by different periods. Results revealed that the emergence percentages in spring (May) were significantly lower than that in fall (September), but the sex ratios did not differ significantly between the two seasons. The emergence asynchrony of parasitoid may be induced by the diapause of species, which is a long-term coevolutional outcome of parasitoid with host for maintaining its population. These findings provided some scientific bases for the rational utilization of this parasitoid in practice.
        92.
        2013.09 구독 인증기관 무료, 개인회원 유료
        A-7-month-old, intact male Shih-Tzu dog was referred with facial dermatitis and stifle pain with 7 days duration. Erythema, hemorrhage, and crusted nodular lesions of the face, swollen eyelids, and otitis externa were observed. A painful response was noted on palpation of the right stifle joint. Impression smears and skin biopsies revealed pyogranulomatous inflammation consistent with canine juvenile cellulitis (CJC). Skin lesions and pain were greatly improved following immunosuppressive corticosteroid therapy. This report firstly describes clinical and histopatho- logical findings as well as treatment responses of CJC in a 7-month-old, domestic dog.
        3,000원
        93.
        2011.10 구독 인증기관·개인회원 무료
        Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinization to predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally.
        94.
        2011.10 구독 인증기관·개인회원 무료
        Sloan-Kettering virus gene product of a cellular protooncogene c-Ski is an unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. The aim of the present study was to locate Ski protein in rat ovaries in order to predict the possible involvement of Ski in follicular development and atresia. First, expression of c-Ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase- mediated dUTP nick end-labeling (TUNEL). Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the shape and size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in immature hypophysectomized rats having a single generation of developing and atretic follicles by treatment with equine chorionic gonadotropin (eCG). These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles, and suggest that Ski plays a role in apoptosis of granulosa cells during follicular atresia.
        95.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinization to predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally.
        4,000원
        96.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Sloan-Kettering virus gene product of a cellular protooncogene c-Ski is an unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. The aim of the present study was to locate Ski protein in rat ovaries in order to predict the possible involvement of Ski in follicular development and atresia. First, expression of c-Ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the shape and size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in immature hypophysectomized rats having a single generation of developing and atretic follicles by treatment with equine chorionic gonadotropin (eCG). These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles, and suggest that Ski plays a role in apoptosis of granulosa cells during follicular atresia.
        4,000원
        99.
        2010.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Magnetars are neutron stars possessing a magnetic field of about 1014-1015 G at the surface. Thermodynamic properties of neutron star matter, approximated by pure neutron matter, are considered at finite temperature in strong magnetic fields up to 1018 G which could be relevant for the inner regions of magnetars. In the model with the Skyrme effective interaction, it is shown that a thermodynamically stable branch of solutions for the spin polarization parameter corresponds to the case when the majority of neutron spins are oriented opposite to the direction of the magnetic field (i.e. negative spin polarization). Moreover, starting from some threshold density, the self-consistent equations have also two other branches of solutions, corresponding to positive spin polarization. The influence of finite temperatures on spin polarization remains moderate in the Skyrme model up to temperatures relevant for protoneutron stars. In particular, the scenario with the metastable state characterized by positive spin polarization, considered at zero temperature in Phys. Rev. C 80, 065801 (2009), is preserved at finite temperatures as well. It is shown that, above certain density, the entropy for various branches of spin polarization in neutron matter with the Skyrme interaction in a strong magnetic field shows the unusual behavior, being larger than that of the nonpolarized state. By providing the corresponding low-temperature analysis, we prove that this unexpected behavior should be related to the dependence of the entropy of a spin polarized state on the effective masses of neutrons with spin up and spin down, and to a certain constraint on them which is violated in the respective density range.
        4,000원
        100.
        2010.10 구독 인증기관·개인회원 무료
        Lettuce was a leaf vegetable with short growing term and cold-tolerant plant. We grew it the whole year. The price of lettuce is the most expensive from July to September. But damages by lots of insect pests appear to greenhouse grown lettuce in summer season. In this study, we observed biological controls of western flower thrips(Franklinella occidentalisi) by the predator mites, Amblyseius swirskii and Neoseiulus cucumeris in lettuce greenhouse from July 7 to September 10. Hypoaspis aculerfer larvae and adults were released 30 individuals per m2 at the first one time as lettuce was planted on the greenhouse. We checked the density of F. occidentalis every 10 days on the 30 lettuce leaves. When the population of F. occidentalis reached 1~5 individuals per a leaf, A. swirskii larvae and adults were released 35 individuals per m2 at 1~3 times and Neoseiulus cucumeris larvae and adults also were released 150 individuals per m2 at 2~3 times in each lettuce greenhouse. During the high temperature season, Amblyseius swirskii was more effective biological controls of F. occidentalis than Neoseiulus cucumeris.
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