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        검색결과 173

        41.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The identification of biomarkers of a living tissues is essentially required to understand specific functions of the cells. In previous study, we reported IGFBP 3 as one of the putative biomarkers, by showing specific expression at porcine spermatogonial stem cells (SSCs) of early stage of porcine testis. In this study, we analyzed the expression of seven members of IGFBP family (IGFBPs) in SSCs and histological expression pattern of pregnancy-associated plasma protein-A (PAPP-A), which plays a role on the growth promoting enzyme by cleavage of IGFBPs in testis of 5 days old pig. RT-PCR analysis showed that IGFBP 1, 2, 3, 4, and 6 were expressed at high level specifically in porcine SSCs compared with whole testis. We performed immunohisotochemical staining of testis sections with PAPP-A and protein gene product 9.5 (PGP9.5) which are the known biomarkers for SSCs. We were not able to find co-expression of PAPP-A and PGP9.5; PAPP-A was expressed only in Sertoli cells and PGP9.5 expression was confirmed in spermatogonium. Additionally, we were able to confirm the GATA4 expression in Sertoli and Leydig cells as a regulator of Sertoli cell function was not detected PGP9.5 expressing cells, indicating indirect evidence of that cytolocalization of PAPP-A expression is limited in Sertoli cells. These results suggested that the PAPP-A expressed in Sertoli cells may play role on regulation of development and differentiation of testicular cells through the IGF axis in neonatal porcine testis.
        4,000원
        42.
        2018.07 구독 인증기관·개인회원 무료
        Climate change is expected to become a considerable threat to life on earth and it already affects certain tourism destinations like mountain regions and costal destinations. For instance, Switzerland is regarded as one of the most popular ski destination worldwide, but today’s ski resorts in Switzerland is facing significant difficulties as weather condition has been particularly harsh for the ski industry in the last years. While ski resorts start to use various rate fences to implement differential pricing, there is relatively little research how their customers perceive these new pricing approaches. Therefore, this study tried to identify how various rate fences adopted in ski resorts, including the use of weather forecasts in differential pricing, are perceived by customers and consequently which of them could be successfully implemented to provide the industry with long-term benefits. In particular, this study focused on the effect of framing and gender on price perception. The study found that female are generally more sensitive to differential pricing and have the tendency to perceive it as less fair.
        43.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although atypical sensory processing is a core feature of autism spectrum disorder (ASD), there is considerable heterogeneity among ASD individuals in the modality and symptoms of atypical sensory processing. The present study examined visual processing of children with ASD, focusing on the complexity and orientation of visual information. Age- and -IQ-matched Korean children (14 ASD and 14 typically-developing (TD) children) received an orientation discrimination task involving static spatial gratings varied in complexity (simple versus complex) and orientation (horizontal versus vertical). The results revealed that ASD children had difficulty perceiving complex information regardless of orientation, whereas TD children had more difficulty with vertical gratings than horizontal gratings. Thus, group-level differences between ASD and TD children appeared greater when gratings were presented horizontally. Unlike ASD adult literature, however, ASD children did not show superior performance on simple gratings. Our findings on typical and atypical processing of ASD children have implications for both understanding the characteristics of ASD children and developing diagnostic tools for ASD.
        4,300원
        47.
        2017.07 구독 인증기관·개인회원 무료
        Individuals use material possessions such as clothes as a means to express their individual predispositions, values and position in their social environment (Kaiser et al., 2001). Evidence indicates that various individual differences such as hormone levels, body image perception and a cosmopolitan orientation influence clothing choices (Eisenbruch et al., 2015, Frith and Gleeson, 2004, Gonzalez-Jimenez, 2016). Moreover, body satisfaction, body mass index and trait self-objectification determine if individuals choose clothes for specific purposes such as fashion, comfort or camouflage (Tiggemann and Andrew, 2012). However, while these studies have made an important step towards understanding the influence of individual characteristics on clothing choices, there is a lack of studies that investigate the role of individuals’ materialist tendencies and propensity to engage in social comparison. We extend prior research on clothing choices by examining the associations between individuals’ materialist tendencies and social comparison propensity with sought clothing functions (i.e., fashion, comfort, etc.). Findings show that materialist individuals seek clothing for specific functions such as fashion, individuality and assurance, while avoiding clothes designed for comfort. Individuals’ propensity to engage in social comparison is linked with choosing clothes for fashion, individuality and assurance, but not for camouflage and comfort. Our study confirms that materialism and social comparison drive individuals to seek very specific clothing functions. Specifically, findings suggest that individuals use specific clothing types as a medium to establish their position in a social environment and to express their materialistic tendencies. Gender influences the tested relationships.
        48.
        2017.05 구독 인증기관·개인회원 무료
        Post-ejaculation of sperms into the female reproductive tract, acquisition of sperm capacitation is an essential step in the fertilization process. Accordingly, during in-vitro fertilization, the successful fertilization requires necessarily induction of capacitation in the retrieved sperms. To date, many candidate substances have been considered as capacitation inducers. However, there were no reports about the comparison of efficiency inducing sperm capacitation among diverse capacitation inducers. Therefore, we tried to determine an inducer showing the best capacitation performance in mouse sperms by comparing the preimplantation development of in-vitro-fertilized embryos using sperms experiencing capacitation by a variety of capacitation inducers. For these, calcium, progesterone, bovine serum albumin (BSA), heparin, lysophosphaticylcholine (Lyso-PC) were used as candidate capacitation inducers. Optimized concentration of each inducer were determined by accessing ratio of sperms experiencing acrosome reaction using coomassie G-250 blue staining. Subsequently, in vitro fertilization was performed using sperms incubated in each optimized concentration inducer. The ratio of fertilized oocytes was observed. As the results, Calcium at 2.7 mM and 0.3% (w/v) BSA showed the highest fertilization rates compared to 15 μM progesterone, 50 mM heparin, and 100 μM Lyso-PC. From these results, we found that 2.7 mM calcium and 0.3% (w/v) BSA were the most effective sperm capacitation inducers of mouse sperm for in vitro fertilization. From these results, we could identify that, among diverse sperm capacitation inducers, 2.7mM calcium and 0.3% (w/v) BSA were the most effective inducers for in vitro fertilization.
        49.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effect of dietary lysine and gamma-linolenic acid(GLA) levels on growth performance, carcass traits, and meat quality in finishing pigs. Pigs were provided with feed containing two different levels of lysine(0.45% and 0.75%) with three different levels of gamma-linolenic acid(0.0, 0.3, and 0.6%). Average daily gain(ADG) was significantly lower (p<0.01) in pigs provided with the lower level of lysine. In contrast, feed/gain(p<0.01), diet cost/gain(p<0.05), and intramuscular fat(p<0.01) were all significantly higher in pigs fed the lower level of lysine. Similarly, meat color scores(CIE L*, a*, and b*) and cooking loss were significantly higher(p<0.01) in pigs fed the lower level of lysine, whereas shear force(kg/2.5 inch2)was not affected by dietary lysine. The addition of GLA had no significant effect on any of the parameters measured. The results indicate that providing pigs with 0.45% lysine in their diet may help to increase intramuscular fat content, allowing the industry to produce pork products that meet consumer needs in Korea.
        4,000원
        50.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of strengthening and stretching exercises on forward head angle and static·dynamic balance ability. 21 adults with the forward head posture were participated in this study. Subjects were randomly assigned to strengthening exercise group I(n=11) and stretching exercise group II (n=10) respectively. Each group were underwent six intervention over the period of 2 weeks, each session lasting 30 minutes. During a preliminary examination, forward head angle and static∙dynamic balance were measured, and a post examination was conducted that involved same procedure as preliminary examination. There were significant differences in forward head angle after exercise in both groups. In the strengthening group, center of gravity total sway distances was significantly changed under all conditions. In the stretching group, center of gravity total sway distances was significantly changed when subjects had their eyes open while standing on an foam surface. There were significant changes in center of gravity sway velocities in the strengthening group under all conditions, and the same was true in the stretching group only when the subjects had their eyes open while standing on an foam surface. In the comparison between groups, eyes closed while standing on a firm surface was significantly different. There was a significant difference in dynamic balance of the stretching group when the subjects tilted their bodies forward, and there was a statistically significant difference between groups under the same condition. The results of this study suggest that forward head posture can be corrected through therapeutic exercise, and muscle strengthening exercise more effective in improving static balance of forward head posture more than stretching exercise.
        4,000원
        52.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated peer-to-peer interaction during collaborative, computer-mediated reading tasks. Fourteen university EFL students in Korea worked in pairs to complete three gapfill tasks. The transcript data from these tasks were analyzed to determine: (1) how often collaboration occurs during collaborative reading tasks, (2) the ways in which peers help each other, and (3) how successful peers are in resolving the problems they collaboratively pursue. The results showed that each of these aspects of interaction varied among sets of pairs. On average, however, the participants collaborated to jointly solve 75% of the problems they encountered. They also used a range of helping behaviors during collaboration. While the participants correctly resolved nearly half of the problems they attempted, half were incorrectly answered or unresolved. Based on these findings, pedagogical implications are offered, in addition to suggestions for future research into collaborative reading tasks.
        6,400원
        54.
        2015.12 구독 인증기관 무료, 개인회원 유료
        This study investigated the potential associations of dog characteristics with serum serotonin (5HT) concentration in dogs with degenerative mitral valve disease (DMVD). Client-owned dogs were prospectively recruited at the Veterinary Medical Teaching Hospital of Chungnam National University between 2010 and 2011. Forty-two dogs (22 females and 20 males) were enrolled in this study. DMVD dogs included Maltese (n=12), followed by Shih-tzu (n=10), mixed breed (n=5), Chihuahua (n=4), Miniature schnauzer (n=3), Miniature poodle (n=3), Miniature pinscher (n=1), Pomeranian (n=1), Yorkshire terrier (n=2), and Spitz (n=1). As inclusion criteria for the study, dogs had to show either direct or echocardiographic evidence of DMVD. Platelet count significantly differed among the three groups, as the moderate (P<0.05) and severe groups (P<0.05) showed significantly higher platelet counts than the mild DMVD group. Additionally, significantly higher LVIDd, LVIDs, fractional shortening (FS), and LA:Ao ratios were observed in dogs with moderate (P<0.05) and severe (P<0.05) DMVD compared to the mild group, respectively. Significant positive correlations between serum 5-hydroxytryptamine (5HT) concentration and platelet count (r=0.273, P=0.03), LA:Ao ratio (r=0.459, P=0.001), and LVIDd (r=0.319, P=0.013) were observed in DMVD dogs. Therefore, serum 5HT concentration may be a potential cause of DMVD progression.
        4,000원
        55.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.
        4,000원
        56.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Three growing wethers were used to investigate the differences in nitrogen (N) retention, blood plasma metabolite concentration and energy-yielding nutrient supply to muscle and adipose tissue. The wethers were fed one of three diets: timothy hay with concentrate (THD), Italian ryegrass with concentrate (IRD), and rice straw with concentrate (RSD) for 11 days. The experimental diets were adjusted to the animals to provide 100 g of daily gain. The triglyceride (TG) concentration of blood plasma in arterial and portal veins was higher with THD and IRD than with RSD. Conversely, the available amount of TG in tissues was higher with IRD. The daily amount of glucose and non-esterified fatty acids (NEFA) supplied to muscle tissue and adipose tissue was numerically higher with THD than IRD or RSD. Although N retention did not differ among the diets, it was numerically higher with THD than with IRD or RSD. The results suggest that the difference in the amount of glucose and NEFA delivered to muscle tissue may reflect the N retention in response to forage based diets.
        4,000원
        58.
        2015.02 구독 인증기관 무료, 개인회원 유료
        Benzene was oxidized by binary oxidants composed of nitric acid and hydrogen peroxide at 80℃. The product obtained was analyzed with gas chromatograph-mass spectrometer. Eight high value compounds, 2-nitrophenol, 2-chloro-6-nitrophenol, 4-chloro-2- nitrophenol, 2-chloro-4-nitrophenol, 2,4-dinitrophenol, 4-nitrophenol, 2,6-dinitrophenol and 2-chloro-4,6-dinitro-phenol were found, which they have high contents in the range from 4.28% to 32.52%. These compounds are very widely used in organic synthesis. e.g., synthesizing dye, medicines and chemical reagents, pesticide, explosive, polymer, etc.
        3,000원
        59.
        2013.10 구독 인증기관·개인회원 무료
        Proteinaceous insecticidal proteins, Cry proteins, from Bacillus thuringiensis (Bt) are insecticidal proteins that are highly active against several species of Lepidoptera. Thus, cry genes encoding these Cry proteins have been widely applied for construction of transgenic crops resistant to pest insects. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. We used site-directed mutagenesis to improve the insecticidal activity of Mod-Cry1Ac, resulted 31 mutant cry genes. These mutant cry genes encodes potent insecticidal proteins in the form of crystalline protoxins of 95 kDa. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella, S. exigua and O. furnacalis were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, Mutant-N16 is considered to have the potential for the efficacious biological insecticide since it showed the highest insecticidal activity.
        60.
        2013.04 구독 인증기관·개인회원 무료
        Crystals of proteinaceous insecticidal proteins, Cry proteins, produced by Bacillus thuringiensis (Bt) have been generally used to control insect pests. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with enhanced insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella and S. exigua were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, among them Mutant-N16 showed the highest insecticidal activity against to both of P. xylostella and S. exigua. Therefore, Mutant-N16 is considered to have the potential for the efficacious biological insecticide.
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