• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.268-275
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• 2004

To investigate the potential application of the single-cell gel electrophoresis (SCGE) assay to carp as an aquatic pollution monitoring technique, gill, liver, and blood cells were isolated from carp exposed to a direct-acting mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or indirect mutagen, $benzo[\alpha]pyrene$ $(B[\alpha]P)$, then the DNA strand breakage was analyzed using the assay. Based on testing 5 different cell isolation methods and 6 electrophoretic conditions, the optimized assay conditions were found to be cell isolation by filter pressing and electrophoresis at a lower voltage and longer running time (at 0.4 V/cm for 40 min). In preliminary experiments, gill and liver cells isolated from carp exposed to MNNG in vitro exhibited DNA damage signals even with 0.5 ppb exposure, which is a much higher dose than previously reported. In the gill cells isolated from carp exposed to 0.01-0.5 ppm MNNG in vivo, significant dose-and time-dependent increases were observed in the tail for 4 days. As such, the linear correlation between the relative damage index (RDI) values and time for each dose based on the initial 48-h exposure appeared to provide effective criteria for the genotoxicity monitoring of direct-acting mutagenic pollution. In contrast, the in vivo exposure of carp to 0.25-1.0 ppm of $B[\alpha]P$ for 7 days resulted in dose-and time-dependent responses in the liver cells, in which 24-h delayed responses for metabolizing activation and gradual repair after 48 h were also observed. Thus, the negative-sloped linear correlation between the RDI and time at each dose based on the initial 48 h appeared to provide more effective criteria for the genotoxicity monitoring of indirect mutagenic pollution.

• Journal of Astronomy and Space Sciences
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• v.30 no.1
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• pp.25-32
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• 2013

We statistically investigated the properties of low-latitude Pi2 pulsations using Bohyun (BOH, Mlat = $29.8^{\circ}$, L = 1.35) ground magnetometer data in 2008. For this 1-year interval, 582 Pi2 events were identified when BOH was in the nightside from 1800 to 0600 local times. We found the following Pi2 characteristics. (1) The occurrence distribution of Pi2s is relatively constant in local times. (2) The Pi2 frequency varies in local times. That is, Pi2 pulsations in postmidnight sector had higher frequency than in premidnight sector. (3) Pi2 power in premidnight sector is stronger than in postmidnight sector. (4) Pi2 frequency has positive correlation with solar wind speed and AE index. (5) Pi2 power has not a clear correlation with solar wind parameters. This indicates that Pi2 power is not controlled by external sources. (6) It is found that the most probable-time between Pi2 onsets is ${\Delta}t$ ~ 37.5 min: This is interpreted to be the period between Pi2 pulsations when they occur cyclically. We suggest that ${\Delta}t$ ~ 37.5 min is the occurrence rate of reconnection of open field lines in the tail lobe.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.29-43
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• 2012

Financial data such as stock index returns and exchange rates have the properties of heavy tail and asymmetry compared to normal distribution. When we estimate VaR using the GARCH model (with the conditional return distribution of normal) it shows the tendency of the lower estimation and clustering in the losses over the estimated VaR. In this paper, we argue that this problem can be resolved through the adaptation of the unbounded Johnson distribution as that of the condition return. We also compare this model with the GARCH with the conditional return distribution of normal and student-t. Using the losses exceed the ex-ante VaR, estimates, we check the validity of the GARCH models through the failure proportion test and the clustering test. We nd that the GARCH model with conditional return distribution of unbounded Johnson provides an appropriate estimation of the VaR and does not occur the clustering of violations.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.273-277
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• 2011

Nitric oxide (NO) and atrial natriuretic peptide (ANP) may induce vascular relaxation by increasing the production of cyclic guanosine monophosphate (cGMP), an important mediator of vascular tone during sepsis. This study aimed to determine whether regulation of NO and the ANP system is altered in lipopolysaccharide (LPS)-induced kidney injury. LPS (10 $mg{\cdot}kg^{-1}$) was injected in the tail veins of male Sprague-Dawley rats; 12 hours later, the kidneys were removed. Protein expression of NO synthase (NOS) and neutral endopeptidase (NEP) was determined by semiquantitative immuno-blotting. As an index of synthesis of NO, its stable metabolites (nitrite/nitrate, NOx) were measured using colorimetric assays. mRNA expression of the ANP system was determined by real-time polymerase chain reaction. To determine the activity of guanylyl cyclase (GC), the amount of cGMP generated in response to sodium nitroprusside (SNP) and ANP was calculated. Creatinine clearance decreased and fractional excretion of sodium increased in LPS-treated rats compared with the controls. Inducible NOS protein expression increased in LPS-treated rats, while that of endothelial NOS, neuronal NOS, and NEP remained unchanged. Additionally, urinary and plasma NOx levels increased in LPS-treated rats. SNP-stimulated GC activity remained unchanged in the glomerulus and papilla in the LPS-treated rats. mRNA expression of natriuretic peptide receptor (NPR)-C decreased in LPS-treated rats, while that of ANP and NPR-A did not change. ANP-stimulated GC activity reduced in the glomerulus and papilla. In conclusion, enhancement of the NO/cGMP pathway and decrease in ANP clearance were found play a role in the pathogenesis of LPS-induced kidney injury.

• The Korean Journal of Malacology
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• v.22 no.1 s.35
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• pp.39-49
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• 2006

Ultrastructure of germ cell differentiation during supermatogenesis and the reproductive cycle in male Patinopecten yessoensis was studied by histological and cytological observations. The gonadosomatic index (GSI) in males rapidly increased and reached a maximum in April when seawater temperature gradually increased. Then the GSI gradually decreased from May through July when spawning occurred. Accordingly, monthly changes in the GSI in males coincided with testicular maturation and spawning periods. The sperm morphology of P. yessoensis belongs to the primitive type and showed general characteristics of external fertilization species. The head of the spermatozoon is approximately $3.50{\mu}m$ in length: the sperm nucleus and acrosome are approximately $2.90{\mu}m\;and\;0.60{\mu}m$ in length, respectively. The nuclear type of the spermatozoon is vase in shape, and the acrosome is cone type. The axoneme of the tail flagellum consists of nine pairs of microtubules at the periphery and a pair of central microtubules in the center The satellite body (which is formed by the centriole) and four mitochondria appear in the middle piece of the spermatozoon. The spawning period was from April through July and the main spawning occurred from May to June when seawater temperatures gradually increased. The reproductive cycle of this species can be classified into five successive stages; early active stage (September to November), late active stage (October to March), ripe stage (February to August), spawning stage (April to July), and spent/inactive stage (July to November).

• Clinical and Experimental Reproductive Medicine
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• v.46 no.2
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• pp.67-75
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• 2019

Objective: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. Methods: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. Results: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. Conclusion: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.63-77
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• 2021

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.171-184
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• 2023

Purpose: First, this paper suggests an alternative approach to find optimal portfolio (stocks, bonds and ESG stocks) under the maximizing utility of investors. Second, we include ESG stocks in our optimal portfolio, and compare improvement of welfares in the case with and without ESG stocks in portfolio. Methods: Our main method of analysis follows Brennan et al(2002), designed under the continuous time framework. We assume that the dynamics of stock price follow the Geometric Brownian Motion (GBM) while the short rate have the Vasicek model. For the utility function of investors, we use the Power Utility Function, which commonly used in financial studies. The optimal portfolio and welfares are derived in the partial equilibrium. The parameters are estimated by using Kalman filter and ordinary least square method. Results: During the overall analysis period, the portfolio including ESG, did not show clear welfare improvement. In 2017, it has slightly exceeded this benchmark 1, showing the possibility of improvement, but the ESG stocks we selected have not strongly shown statistically significant welfare improvement results. This paper showed that the factors affecting optimal asset allocation and welfare improvement were different each other. We also found that the proportion of optimal asset allocation was affected by factors such as asset return, volatility, and inverse correlation between stocks and bonds, similar to traditional financial theory. Conclusion: The portfolio with ESG investment did not show significant results in welfare improvement is due to that 1) the KRX ESG Leaders 150 selected in our study is an index based on ESG integrated scores, which are designed to affect stability rather than profitability. And 2) Korea has a short history of ESG investment. During the limited analysis period, the performance of stock-related assets was inferior to bond assets at the time of the interest rate drop.

• CELLMED
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• v.13 no.14
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• pp.15.1-15.15
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• 2023

Background and objective: A new formular CPC22 consists of Cynanchum wilfordii root, Pueraria thomsonii flower, and Citrus unshiu peel and has been developed to improve the postmenopausal symptoms. The research intended to evaluate whether CPC22 would regulate bone loss, hot flashes, and dysregulated lipid metabolism in ovariectomized (OVX) postmenopausal mice. Method: The OVX mice were orally administered with CPC22 daily for 7 weeks. Results: CPC22 regulated OVX-induced bon loss by enhancing serum osteoprotegerin, alkaline phosphatase, and osteocalcin levels and diminishing serum receptor-activator of the NF-κB ligand (RANKL), collagen type 1 cross-linked N-telopeptide, and tartrate-resistant acid phosphatase levels. As a result of CPC22 treatment, notable decreases in tail skin temperature and rectal temperature were observed, along with diminishment in hypothalamic RANKL and monoamine oxidase A levels and enhancement in hypothalamic serotonin (5-HT), norepinephrine, dopamine, 5-HT2A, and estrogen receptor-β levels. CPC22 enhanced levels of serum estrogen and diminished levels of serum follicle-stimulating hormone and luteinizing hormone. CPC22 regulated levels of serum lipid metabolites, including total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Furthermore, CPC22 diminished levels of serum blood urea nitrogen, creatine kinase, alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase and restored vaginal dryness without affecting uterus atrophy index and vagina weights. Conclusion: Therefore, these results indicated that CPC22 improves OVX-induced bone loss, hot flashes, and dysregulated lipid metabolism by compensating for estrogen deficiency without side effects, suggesting that CPC22 may be used for the prevention and treatment of post menopause.

• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.241-254
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• 2013

The nutria(Myocastor coypus) that is originated from South America is a representative Invasive alien species in Korea. invasive alien species is one of the biggest causes for the loss of biodiversity and it may threaten the conservation and function of ecology as well as the welfare of mankind. Intense habitation has been made around the Nakdong River basin area that this study has analyzed the habitat density of nutria for the subject of 3 survey sites in the Nakdong River basin area. As a result of survey on habitation density in 2011 and 2012, under St.1 it was shown $2.01{\pm}0.21$/ha in 2011 and $0.69{\pm}0.55$/ha in 2012. Under St.2, it was shown $0.91{\pm}0.37$/ha in 2011 and $0.55{\pm}0.39$/ha in 2012. Under St.3, it was shown $5.31{\pm}0.72$/ha in 2011 and $3.99{\pm}2.31$/ha in 2012. The wet survey areas of St.1 and St.3 had shown relatively high habitation density compared to St. 2, the river survey area, and the average annual habitation density of the survey area was $2.74{\pm}2.29$/ha in 2011 and $1.74{\pm}1.18$/ha in 2012 that it has shown slightly reducing trend. As a result of measuring the morphology by capturing the habitation individuals, the average body length of adults is $92.23{\pm}9.41cm$, the length from the head to body for $53.90{\pm}5.15cm$, tail length for $38.33{\pm}4.83cm$, hind foot length for $13.82{\pm}1.00cm$, front foot length for $6.02{\pm}0.56cm$, and weight for $5.48{\pm}1.08kg$. As a result of comparing the types between genders, male showed a slightly higher figure in all parts compared to female and it showed significantly difference in total body length, head-body length, front foot length and total weight. As a result of analysis for each head-body length, other measured parts, weight and relativity for each measured part, all bodily part is shown to have the higher volume of correlations. The condition index of individuals in the survey area was shown in the average of $35.67{\pm}4.78$ with female for an average of $36.60{\pm}5.19$ and male for an average of $34.73{\pm}4.34$. The winter temperature in the southern area of Korea is considered for not greatly impacting on the habitation and development of nutria that, if there is no artificial control, it is considered to have certain concern of showing drastic breeding and territory expansion for the habitation group.