• Development and Reproduction
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• v.13 no.4
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• pp.207-215
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• 2009

Numerous factors can affect the activities of hypothalamus-pituitary-gonad (HPG) hormonal axis, resulting in alteration of reproductive capacity or status such as onset of puberty and menopause. Soon after the finding of leptin, a multifunctional hormone secreted from adipocytes, a close relationship between reproduction and body energy balance have been manifested. Ghrelin, another multifunctional hormone from gastrointestinal tract, is an endogenous ligand of growth hormone secretagogue receptor (GHSR), and is thought to be a counterpart of leptin in the regulation of energy homeostasis. As expected, ghrelin can also modulate the reproductive capacity through the modulation of activities of HPG axis. This paper summarizes the current knowledge on the discovery, gene structures, tissue distribution and roles of ghrelin and GHSRs in mammalian reproduction in particular modulation of reproductive hormone secretion in HPG axis. Like POMC gene expression in pituitary gland, preproghrelin gene can generate a complex repertoire of transcripts which further undergo alternative splicing and posttranslational modifications. Concerning the roles of preproghrelin gene products in the control of body physiology except energy homeostasis, limited knowledge is available so far. Several lines of evidence, however, show the interplay of ghrelin between metabolism and reproduction. In rat and human, the distribution of ghrelin receptor GHSRs (GHSR1a and GHSR1b) has been confirmed not only in the hypothalamus and pituitary which were originally postulated as target of ghrelin but also in the testis and ovary. Expression of the preproghrelin gene in the brain and gonads was also verified, suggesting the local role (s) of ghrelin in HPG axis. Ghrelin might play a negative modulator in the secretions of hypothalamic GnRH, pituitary gonadotropins and gonadal steroids though the action on pituitary is still questionable. Recent studies suggest the involvement of ghrelin in regulation of puberty onset and possibly of menopause entry. It is now evident that ghrelin is a crucial hormomal component in 'brain-gut' axis, and is a strong candidate links between metabolism and reproduction. Opposite to that for leptin, ghrelin signaling is likely representing the 'hunger' state of body energy balance and is necessary to avoid the energy investment into reproduction which has not a top priority in maintaining homeostasis. Further researches are needed to gain a deep insight into the more precise action mechanism and role of ghrelin in reproduction, and to guarantee the successful biomedical applications.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.527-539
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• 2010

This study was conducted to determine the effect of probiotics as an alternative for antibiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in growing piglets. A total of 96 piglets ($22.5{\pm}1.3$kg average body weight) were allotted to 3 different treatment groups and replicated 4 times with 8 piglets per replicate in randomized complete block design. Treatments were T1) (Control, basal diet+0.2% antibiotics), T2) 0.2% probiotics complex and T3) 0.3% Bacillus probiotics. During the whole experiment period, there were no differences (p>0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency. However, digestibility of dry matter, crude protein, ether extract, nitrogen free extract and crude ash were showed higher in probiotics groups (T2 and T3) than those of control. In noxious gas emission, ammonia, amine, hydrogen sulfide and mercaptan were significantly (p<0.05) reduced in T2 and T3 treatments compared to those in control. Moisture content of feces was not significantly different among treatments. The colony forming units (CFU) of total bacteria, E. coli and thermoduric bacteria in feces were significantly different among treatments. The CFU of total bacteria, E. coli and thermoduric bacteria in T3 treatment were reduced by feeding probiotics B. From this study, we suggest that probiotics A and B are likely able to improve the growth performance and nutrients digestibility, reduce noxious gas emission and change the fecal microbial composition in growing piglets.

• Journal of Life Science
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• v.30 no.2
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• pp.211-220
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• 2020

The activity of CAR can be regulated not only by ligand binding but also by phosphorylation of regulatory factors involved in extracellular signaling pathways, cross-talk interactions with transcription factors, and the recruitment, degradation, and expression of coactivators and corepressors. This regulation of CAR activity can in turn have effects on the control of diverse physiological homeostasis, including xenobiotic and energy metabolism, cellular proliferation, and apoptosis. CAR is phosphorylated by the ERK1/2 signaling pathway, which causes formation of a complex with Hsp-90 and CCRP, leading to its cytoplasmic retention, whereas phenobarbital inhibits ERK1/2, which causes dephosphorylation of the downstream signaling molecules, leading to the recruitment to CAR of the activated RACK-1/PP2A components for the dephosphorylation, nuclear translocation, and the transcriptional activation of CAR. Activated CAR cross-talks with FoxO1 to induce inhibition of its transcriptional activity and with PGC-1α to induce protein degradation by ubiquitination, resulting in the transcriptional suppression of PEPCK and G6Pase involved in gluconeogenesis. Regulation by CAR of lipid synthesis and oxidation is achieved by its functional cross-talks, respectively, with PPARγ through the degradation of PGC-1α to inhibit expression of the lipogenic genes and with PPARα through either the suppression of CPT-1 expression or the interaction with PGC-1α each to induce tissue-specific inhibition or stimulation of β-oxidation. Whereas CAR stimulates cellular proliferation by suppressing p21 expression through the inhibition of FoxO1 transcriptional activity and inducing cyclin D1 expression, it suppresses apoptosis by inhibiting the activities of MKK7 and JNK-1 through the expression of GADD45B. In conclusion, CAR is involved in the maintenance of homeostasis by regulating not only xenobiotic metabolism but also energy metabolism, cellular proliferation, and apoptosis through diverse cross-talk interactions with extracellular signaling pathways and intracellular regulatory factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.187-194
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• 2010

The soybean stay green mutant genotype (SSG) derived from the nuclear gene, d1d2, and cytoplasmic gene, cytG, inhibit the breakdown of chloroplast in the leaves, pod walls, seed coats, and embryos during maturity. Soybean seed with black seed coat and green cotyledon (SBG) are preferred than black seed coat with yellow cotyledon (SBY) especially for cooking with rice and as source of traditional food in Korea. The researchers evaluated the seed's chlorophyll content of SSG and introduced SSG to the SBG variety breeding program. The seed chlorophyll content of SSG with d1d2 was $39.93{\sim}60.80\;{\mu}g/g$ and SSG with cytG $38.08{\sim}39.89\;{\mu}g/g$. The Korean SBG variety which was derived from SSG with cytG, contains $16.35{\sim}37.73\;{\mu}g/g$. The composition of seed chlorophyll differs according to the genetic background of SSG genotype. Inheritance study showed that cotyledon color was segregated 15:1 (yellow:green) at $F_2$ seed indicating two recessive genes control green cotyledon as revealed by previous study. Only less than 3% soybean lines showed black seed coat with green cotyledon among crosses SBY and SSG (d1d2). Results showed that SSG with d1d2 can be used as a good source for SBG with high chlorophyll content in the seed cotyledon, but due to the complex genetic behavior, breeding resource of SBG with d1d2 should be prepared to improve the breeding efficiency for development SBG variety.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.1
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• pp.19-26
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• 2017

Surface air temperature ($T_{air}$) is a key variable for the meteorology and climatology, and is a fundamental factor of the terrestrial ecosystem functions. Satellite remote sensing from the Moderate Resolution Imaging Spectroradiometer (MODIS) provides an opportunity to monitor the $T_{air}$. However, the several problems such as frequent cloud cover and mountainous region can result in substantial retrieval error and signal loss in MODIS $T_{air}$. In this study, satellite-based $T_{air}$ was estimated under both clear and cloudy sky conditions in Gangwon Province using Aqua MODIS07 temperature profile product (MYD07_L2) and GCOM-W1 Advanced Microwave Scanning Radiometer 2 (AMSR2) brightness temperature ($T_b$) at 37 GHz frequency, and was compared with the measurements from the Automated Mountain Meteorology Stations (AMOS). The application of ambient temperature lapse rate was performed to improve the retrieval accuracy in mountainous region, which showed the improvement of estimation accuracy approximately 4% of RMSE. A simple pixel-wise regression method combining synergetic information from MYD07_L2 $T_{air}$ and AMSR2 $T_b$ was applied to estimate surface $T_{air}$ for all sky conditions. The $T_{air}$ retrievals showed favorable agreement in comparison with AMOS data (r=0.80, RMSE=7.9K), though the underestimation was appeared in winter season. Substantial $T_{air}$ retrievals were estimated 61.4% (n=2,657) for cloudy sky conditions. The results presented in this study indicate that the satellite remote sensing can produce the surface $T_{air}$ at the complex mountainous region for all sky conditions.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.719-728
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• 2004

The aims of this study were to estimate genetic parameters for carcass traits on Hanwoo(Korean Native Cattle) and to compare two different statistical algorithms for estimating genetic parameters. Data obtained from 1526 steers at Hanwoo Improvement Center and Hanwoo Improvement Complex Area from 1996 to 2001 were used for the analyses. The carcass traits considered in these studies were carcass weight, dressing percent, eye muscle area, backfat thickness, and marbling score. Estimated genetic parameters using EM-REML algorithm were compared to those by Bayesian inference via Gibbs Sampling to find out statistical properties. The estimated heritabilities of carcass traits by REML method were 0.28, 0.25, 0.35, 0.39 and 0.51, respectively and those by Gibbs Sampling method were 0.29, 0.25, 0.40, 0.42 and 0.54, respectively. This estimates were not significantly different, even though the estimated heritabilities by Gibbs Sampling method were higher than ones by REML method. Since the estimated statistics by REML method and Gibbs Sampling method were not significantly different in this study, it is inferred that both mothods could be efficiently applied for the analysis of carcass traits of cattle. However, further studies are demanded to define an optimal statistical method for handling large scale performance data.

• Analytical Science and Technology
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• v.26 no.3
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• pp.165-173
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• 2013

To establishment of PT Program for Indoor air quality field that manufacture of confidential development PTMs (proficiency testing materials) and examined of proficiency testing evaluation included sampling process whether or not that is valid. Confirmation of homogeneity and stability of PTMs prepared. PTMs were confirmed to be homogeneous enough to be used as proficiency testing materials since withinbottle homogeneities of the RMs were lower than 0.3 times of targeted standard deviation of proficiency testing. The result of this study showed that the Robust RSD of proficiency testing for VOCs (volatile organic compounds) appeared 23~43% in concentration of 50~320 ${\mu}g/m^3$ for Method A(Distribution by adsorption in Tenax-tube of VOCs), but less 13~42% in concentration of 200~1200 ${\mu}g/m^3$, 16~31% in concentration of 100~450 ${\mu}g/m^3$ for Method B (distribution by VOCs of gas phase in 10L Tedalr bag), C (directly sampling of cylinder with high pressure) respectively. The result of this study showed that method C with sampling is most adequate to the proficiency testing for VOCs in indoor air.

• Journal of Chest Surgery
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• v.39 no.3 s.260
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• pp.177-183
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• 2006

Background: The bidirectional cavopulmonary shunt (BCPS) is one of the primary palliative procedures for complex congenital heart disease. It has many advantages, but it is known to have high risks in young infants. Material and Method: From 1995 to 2003, 48 infants under the age of one year underwent BCPS. All the patients were Fontan candidates due to functional univentricular heart physiology. There were no significant differences in preoperative variables, except in mean age (67.58$\pm$3.78 vs. 212.91$\pm$13.44 days), and mean body weight (4.51$\pm$0.29 vs. 6.62$\pm$0.27 kg), between group A (<3 months, n=12) and group B ($\ge$3 months, n=36). Result: In group A, the arterial oxygen saturations serially measured were significantly lower. Hospital mortality was $25\%$, and $19\%$, respectively. During follow up, there were 2 late mortalities in group A, and 5 in group B. Conclusion: This study showed that operative risk in young infants was comparable to that of older patients, and BCPS could be a good option as a primary palliative procedure, and may eliminate other repeated palliative procedures which could be the risk factors for Fontan candidates. However, in high-risk patients accompanying pulmonary hypertension, or heterotaxia syndrome, other palliative procedures should be considered.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.789-792
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• 2010

Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

• Land and Housing Review
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• v.13 no.4
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• pp.55-71
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• 2022

Recently, the domestic department store industry is growing into a complex shopping cultural space, which is advanced and differentiated by changes in consumption patterns. In addition, competition is intensifying across 70 places operated by five large companies. This study investigates the determinants of the visits to department stores using the big data concept's automatic vehicle access system (pos) and proposes how to strengthen the competitiveness of the department store industry. We use a negative binomial regression test to predict the frequency of visits to 67 branches, except for three branches whose annual sales were incomplete due to the new opening in 2021. The results show that the demand for visiting department stores is positively associated with airport, terminal, and train stations, land areas, parking lots, VIP lounge numbers, luxury store ratio, F&B store numbers, non-commercial areas, and hotels. We suggest four strategies to enhance the competitiveness of domestic department stores. First, department store consumers have a high preference for luxury brands. Therefore, department stores need to form their own overseas buyer teams to discover and attract new luxury brands and attract customers who have a high demand for luxury brands. In addition, to attract consumers with high purchasing power and loyalty, it is necessary to provide more differentiated products and services for VIP customers than before. Second, it is desirable to focus on transportation hub areas such as train stations, airports, and terminals in Gyeonggi and Incheon. Third, department stores should attract tenants who can satisfy customers, given that key tenants are an important component of advanced shopping centers for department stores. Finally, the department store, a top-end shopping center, should be developed as a space with differentiated shopping, culture, dining out, and leisure services, such as "The Hyundai", which opened in 2021, to ensure future growth potential.