• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.176-181
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• 1999

The variations of gene expression and pituitary contents of GTH subunits during the ovarian development of masu salmon, Oncorhynchus masou, were investigated. The pituitary GTHs contents was measured by radioimmunoassays (RIAs) using purified GTH subunits and their antibodies. Pituitary contents of GTH $I\beta$ gradually increased from April through August, and reached the maximum in October. On the other hand, pituitary contents of GTH $II\beta$ remained low until August, but they rapidly increased in October. Total RNAs were prepared from pooled pituitaries and the GTH subunits mRNA in pituitaries was quantified by Northern blot hybridization using masu salmon cDNA probes for each GTH subunit. GTH $I\beta$ mRNA level increased with the progression of ovarian maturity. However, GTH $II\beta$ mRNA was detected only at a more advanced stage, and were extremly high at ovulation. A high levels for GTH a mRNA was detected only at ovulation stage. The synchronous increase in pituitary contents and mRNA levels suggested that ovarian maturity in masu salmon was regulated by both GTH I and GTH II.

• Korean Journal of Child Studies
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• v.32 no.5
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• pp.67-84
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• 2011

This study examined the effects of parental control and children's autonomy on self-esteem, using a sample of 415 school-age children (208 boys and 207 girls) recruited in Seoul. Ordinary Least Square regressions revealed a variety of gender-based differences in the associations among these three variables. Boys with high maternal behavioral control had high levels of self-esteem, whereas girls under low paternal psychological and high behavioral control reported high levels of self-esteem. Boys with high maternal behavioral control and girls with high paternal behavioral control also reported high levels of autonomy. Autonomy was found to exert a positive impact on self-esteem for both boy and girls. Autonomy played a mediating role in the relationships between maternal behavioral control and self-esteem for boys, and between paternal behavioral control and self-esteem for girls. These findings highlight the differential influences of psychological control and behavioral control on autonomy and self-esteem, as well as the relative impact of the opposite sex parent on the development of autonomy and self-esteem in late childhood.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.437-444
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• 2013

Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

• Journal of the korean society of oceanography
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• v.35 no.2
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• pp.89-97
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• 2000

The pyritization of heavy metals in Lake Shihwa sediments was investigated to determine sedimentary Pyrite-heavy metal associations influenced by various metal fractions, organic carbon, and total reduced sulfur. Parameters indicating the degree of heavy metal pyritization (DTMP) and degree of pyritization (DOP) were used to study the incorporation of heavy metals into the pyrite phase. The DOP levels ranged from 3.28-39.45%, showing wide differences among sampling stations. The levels were greater near the water gate and the center of the lake than near the industrial complex. The spatial pattern of the DOP levels was similar to the S/C ratio and also to the salinity. Based on the measured relationships between DOP and DTMP, heavy metals can be divided into three groups. In the first group was As, which showed a high affinity for pyrite. In the second group were Ni, Co and Cu, which showed a gradual increase in DTMP with increasing DOP. In the final group were Pb, Zn, Mn and Cr, which all showed a low DTMP with constant values with respect to DOP.

• Journal of Korean Physical Therapy Science
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• v.9 no.4
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• pp.45-52
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• 2002

Rats that are fed a fructose-rich diet develop hypertension, insulin resistance, and hypertriglyceridemia. To elucidate whether altered expression levels of endothelin-1 and nitric oxide synthase are related to the development of insulin-resistant hypertension, we examined the present study. Male Sprague-Dawley rats were fed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid and plasma nitrite/nitrate levels did not significantly differ between the fructose-fed and control groups, plasma insulin and serum triglyceride concentrations significantly increased in the former. Endothelin-1 mRNA expression in the aorta increased in fructose-fed rats. Neither the protein expression of constitutive nitric oxide synthase nor that of inducible nitric oxide synthase were significantly affected by fructose feeding. However, nitrite/nitrate levels in the aorta were significantly increased. These results suggest that an increase in vascular endothelin-1 is an important contributing factor to the development of hypertension in fructose-fed rats. However, the vascular nitric oxide pathway may not be causally related to the development of fructose-induced hypertension.

• Korean Journal of Child Studies
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• v.33 no.1
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• pp.111-131
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• 2012

This study examined the relationship between parenting, the quality of peer relationships, and loneliness in adolescents. This study also examined the mediating effects of the quality of peer relationships on the relationship between parenting and adolescents' loneliness. A total of 506 1st and 2nd grade middle school students (261 boys and 245 girls) from the Seoul Metropolitan area completed measures of parenting, the quality of their peer relationships, and loneliness. The results indicated that adolescents' perceptions of parenting and the quality of their peer relationships were significantly related to their feelings of loneliness. Specifically, adolescents' perceptions of low levels of parental monitoring and high levels of abusive and neglectful parenting were associated with high levels of loneliness. Adolescents who perceived the quality of their peer relationships to be low reported high levels of loneliness. Further, the quality of peer relationships mediated the relationship between parenting and adolescents' loneliness; however, the pattern of associations differed for boys and girls. These findings suggest that both parent and peer relationship factors should be considered in combination in order to better explain loneliness in adolescents.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.432-437
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• 1997

We used a herbal medicine, roots of Rhodiola sachalinensis (RS) to assess whether RS extract can decrease blood ethanol concentrations in rats fed ethanol and if so, to elucidate the mechanism by which RS extract reduces blood ethanol levels. Rats were fed ethanol orally 1 hr after the oral administration of various doses of RS extract. In another experiment, rats were injected intraperitoneally with ethanol following the intake of RS extract via gastric catheter to eliminate possible inhibition of ethanol absorption in the gastrointestine by RS extract. The administration of RS extract remarkably lowered blood ethanol levels in a dose-dependent manner in rats given ethanol orally. However, the intake of RS extract did not reduce ethanol levels in rats injected with ethanol intraperitoneally. The activities of two main hepatic enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), involved in ethanol metabolism, were not affected by the administration of RS extract in rats fed ethanol. In addition, the intake of RS extract reduced serum triglyceride levels elevated by ethanol to the normal level. We conclude that the administration of RS extract lowers blood ethanol concentrations by inhibition of ethanol absorption in the gastrointestinal tracts of ethanol-fed animals.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.641-648
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• 2011

This study investigated the effects of high pressure with or without thermal treatment on the cured color development and residual nitrite contents of model meat systems (pork, NaCl and sodium nitrite). At low nitrite levels (${\leq}50{\mu}g/g$), 200 MPa of pressure alone (P) did not develop the cured meat color (p>0.05). Thermal treatment (T) showed curing pigmentation (higher CIE L* and CIE a*), and the impacts were more effective when pressure was combined with thermal treatment (PT). In contrast, nitrite levels did not contribute to the cured meat color when ${\geq}200{\mu}g/g$ of nitrite was added to the meat. At high nitrite levels, although the typical cured color that is induced by thermal treatment did not present by pressure alone, the PT treatment still showed a pinker color with low residual nitrite content compared to the T treatment. The higher the pressure level (300 MPa), the greater the cured meat pigmentation with lower residual nitrite. Therefore, the present study demonstrates the possible application of high pressure, both for cured pigmentation and reducing residual nitrite, respective to typical thermal treatments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.2
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• pp.120-128
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• 2015

Quality function deployment (QFD) is a useful method in product design and development to maximize customer satisfaction. In the QFD, the technical attributes (TAs) affecting the product performance are identified, and product performance is improved to optimize customer requirements (CRs). For product development, determining the optimal levels of TAs is crucial during QFD optimization. Many optimization methods have been proposed to obtain the optimal levels of TAs in QFD. In these studies, the levels of TAs are assumed to be continuous while they are often taken as discrete in real world application. Another assumption in QFD optimization is that the requirements of the heterogeneous customers can be generalized and hence only one house of quality (HoQ) is used to connect with CRs. However, customers often have various requirements and preferences on a product. Therefore, a product market can be partitioned into several market segments, each of which contains a number of customers with homogeneous preferences. To overcome these problems, this paper proposes an optimization approach to find the optimal set of TAs under multi-segment market. Dynamic Programming (DP) methodology is developed to maximize the overall customer satisfaction for the market considering the weights of importance of different segments. Finally, a case study is provided for illustrating the proposed optimization approach.

• Toxicological Research
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• v.27 no.2
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• pp.103-110
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• 2011

Lipotoxicity involves pathological alterations to cells and tissues in response to elevated fat levels in blood. Furthermore, this process can disturb both cellular homeostasis and viability. In the current study, the authors show that neural progenitor cells (NPCs) are vulnerable to high levels of palmitic acid (PA) a saturated fatty acid. PA was found to cause cell death associated with elevated reactive oxygen species (ROS) levels, and to reduce NPCs proliferation. To evaluate the lipotoxicity of PA in adult NPCs in the hippocampus, male C57BL/6 mice were divided into two groups and maintained on either a normal diet (ND) or PA-rich high fat diet (HFD) for 2 weeks. Interestingly, short-term PA-rich HFD feeding reduced the survival of newly generated cells in the hippocampal dentate gyrus and hippocampal brain-derived neurotrophic factor levels. These findings suggest PA has a potent lipotoxicity in NPCs and that a PA-rich HFD disrupts hippocampal neurogenesis.