• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.12-23
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• 2021

As fish communities are sensitive to natural environmental changes as well as anthropogenic pressures, their composition and characteristics help us to assess the aquatic ecosystem health. The fish fauna and the length-weight relationship of Zacco platypus in the Seomjin River system were investigated from July 2018 to May 2019. The collected species during the survey period were 49 species belong to 14 families including 19 Korean endemic and two endangered species. According to Bray-Curtis similarities, 14 sites were divided into four groups based on the fish community composition; two groups(group A, B) and two uncategorized sites(group C, D). There were significant differences between groups A and B(analysis of similarities, R=0.722, p=0.002). A similarity percentage analysis revealed that Z. koreanus(8.55%), Micropterus salmoides(6.90%), and Lepomis macrochirus (4.90%) contributed to these differences of fish assemblages between group A and B. Group A showed higher relative abundances of exotic species such as M. salmoides and L. macrochirus, while Z. platypus and Z. koreanus which are the common species in Korea, were the most dominant species in group B. Based on the length-weight relationship of Z. platypus, b values were varied from 2.82 to 3.80, indicating that growth patterns of the species were spatially different. This study could be served as baseline data for understanding fish fauna, assessing habitat characteristics based on the fauna, and identifying health conditions of Z. platypus in the Seomjin River system.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.111-123
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• 2021

Objective: Using domestic cats as a biomedical research model for fertility preservation, the present study aimed to characterize the influences of ovarian tissue encapsulation in biodegradable hydrogel matrix (fibrinogen/thrombin) on resilience to cryopreservation, and static versus non-static culture systems following ovarian tissue encapsulation and cryopreservation on follicle quality. Methods: In experiment I, ovarian tissues (n=21 animals; 567 ovarian fragments) were assigned to controls or hydrogel encapsulation with 5 or 10 mg/mL fibrinogen (5 or 10 FG). Following cryopreservation (slow freezing or vitrification), follicle viability, morphology, density, and key protein phosphorylation were assessed. In experiment II (based on the findings from experiment I), ovarian tissues (n=10 animals; 270 ovarian fragments) were encapsulated with 10 FG, cryopreserved, and in vitro cultured under static or non-static systems for 7 days followed by similar follicle quality assessments. Results: In experiment I, the combination of 10 FG encapsulation/slow freezing led to greater post-thawed follicle quality than in the control group, as shown by follicle viability (66.9%±2.2% vs. 61.5%±3.1%), normal follicle morphology (62.2% ±2.1% vs. 55.2%±3.5%), and the relative band intensity of vascular endothelial growth factor protein phosphorylation (0.58±0.06 vs. 0.42±0.09). Experiment II demonstrated that hydrogel encapsulation promoted follicle survival and maintenance of follicle development regardless of the culture system when compared to fresh controls. Conclusion: These results provide a better understanding of the role of hydrogel encapsulation and culture systems in ovarian tissue cryopreservation and follicle quality outcomes using an animal model, paving the way for optimized approaches to human fertility preservation.

• Animal Bioscience
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• v.35 no.1
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• pp.64-74
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• 2022

Objective: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens. Methods: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T₁ (negative control-basal diet), T₂ (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T₃ (MSP at 10⁷ colony-forming unit [CFU]/g feed), and T₄ (MSP at 10⁸ CFU/g feed). Results: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T₃ and T₄ groups. The feed intake significantly (p<0.05) reduced from T₁ to T₃ during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T₃ and T₄ during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T₃ and T₄. However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T₃ followed by T₄ and T₂. At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT₁) and peptide transporter (PepT₁) showed a significant (p<0.05) up-regulating pattern in T₂, T₃, and T₄. Whereas, at 21 d post hatch, the gene expression of SGLT₁ and PepT₁ was significantly (p<0.05) downregulated in MSP supplemented treatments T₃ and T₄. Conclusion: The supplementation of MSP at 10⁷ CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.278-286
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• 2021

The habitat characteristics and feeding ecology of the Siberian stone loach Barbatula toni were investigated in Bukcheon (Stream), Eocheonri, Ganseong-eup, Goseong-gun, and Gangwon-do, Korea from January to December 2013. B. toni lived in rapids or slow rapids from the upper stream to downstream, with the largest number of inhabitants in the middle-downstream regions. As a result of analyzing habitat preferences by age, 0+ and 1+ to ≥3+ showed differences. Ages of 0+(juveniles) lived mainly in rapidly flowing water (37.6±26.79 cm/sec) and low water depths (13.3±9.47 cm) in the pebble bottoms (substratum particle size 9.5±6.66 cm), but ages 1+ to ≥3+ lived mainly in relatively slowly flowing water (13.3±17.33 cm/sec) and relatively deep depths (25.9±10.31 cm) in stone and large stone bottoms (substratum particle size 18.0±7.63 cm). B. toni was mainly eaten from March to December when the temperature was above 5℃, and the amount of food eaten peaked in June and October. Their main food sources analyzed by the index of relative importance (IRI) included Diptera (57.0%), Ephemeroptera (29.3%), and Trichoptera (13.5%). The juveniles (age 0+) fed on small-sized prey such as Diptera and Trichoptera whales, but as they grew, they mainly ate large-sized Ephemeroptera. These feeding habits and changes in food according to the growth of B. toni were very similar to those of sibling species, B. nuda.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.83-92
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• 2022

The 2020 summer extreme flood severely disturbed the riparian ecosystem of the Seomjin River. Some trees were killed by the flood impact, whereas others have recovered through epicormic regeneration after the disturbance. At the same time, several tree individuals newly germinated. This research aimed to explain the recovery of the riparian ecosystem by spatial proximity between each tree individual of different characteristics, such as "dead", "recovered", and "newly germinated". A spatial point pattern analysis based on K and g-functions revealed that the newly germinated trees and the existing trees were distributed in the spatially clumping patterns. However, further detailed analysis revealed that the new trees were statistically less attracted to the recovered trees than the dead trees, implying competitive interactions hidden in the facilitative interactions. Habitat amelioration by the existing trees positively affected the growth of the new trees, while "living" existing trees were competing with the new trees for resources. This research is expected to provide new knowledge in this era of rapid climate change, which likely induces stronger and more frequent natural disturbance than before. Environmental factors have been widely used for ecosystem modeling, but species interactions, represented by the relative spatial distribution of plant individuals, are also valuable factors explaining ecosystem dynamics.

• Animal Bioscience
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• v.35 no.11
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• pp.1733-1743
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• 2022

Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet. Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme. Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed bran-containing diet. Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet.

• Journal of Mushroom
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• v.20 no.3
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• pp.127-137
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• 2022

Effects of substrate bed interior environments on mushroom qualities were investigated in oyster mushroom cultivation facilities in which either Reversible Air-Circulation Fans (RACF) blowing air in two directions (upwards and downwards) or customary Convection Fans (CF) with air blowing only upwards were operated throughout the cultivation period. Two days before harvest, the deviation ranges of the bed interior temperature and relative humidity in the facility using RACF were in the ranges of 1.0-1.3℃ and 7.8-9.0% in the first growing cycle, and within 0.7-1.1℃ and 10.0-11.4% in the second cycle. In the facility using CF, the ranges of variation in the indoor environment parameters (5.8-6.4℃ and 21.3-23.1% in the first growing cycle, and 3.4-5.7℃ and 14.6-18.3% in the second growing cycle) were much enlarged compared to those associated with RACF. These results strongly indicate that RACF significantly enhances air uniformity. Some mushroom qualities differed between growing cycles. For instance RACF in the first cycle gave somewhat better qualities than CF, but some qualities, like pileus diameter and stipe length, were slightly lower than those described for CF in the second cycle when the cultivation substrate weakened. The observation that some qualities worsened under RACF conditions, despite better air uniformity during the growing cycle, revealed the possibility that downward wind may exert a non-negligible negative effect on mushroom growth. Therefore in the future, making wind measurements on the interior and exterior of substrate beds is necessary to obtain insights into their influences on mushroom qualities. The RACF operation manual needs to be edited to convey this necessity.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.597-608
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• 2022

Remotely sensed data have been used in various fields, such as disasters, agriculture, urban planning, and the military. Recently, the demand for the multitemporal dataset with the high-spatial-resolution has increased. This manuscript proposed an automatic image matching algorithm using a deep learning technique to utilize a multitemporal remotely sensed dataset. The proposed deep learning model was based on High Resolution Net (HRNet), widely used in image segmentation. In this manuscript, denseblock was added to calculate the correlation map between images effectively and to increase learning efficiency. The training of the proposed model was performed using the multitemporal orthophotos of the National Geographic Information Institute (NGII). In order to evaluate the performance of image matching using a deep learning model, a comparative evaluation was performed. As a result of the experiment, the average horizontal error of the proposed algorithm based on 80% of the image matching rate was 3 pixels. At the same time, that of the Zero Normalized Cross-Correlation (ZNCC) was 25 pixels. In particular, it was confirmed that the proposed method is effective even in mountainous and farmland areas where the image changes according to vegetation growth. Therefore, it is expected that the proposed deep learning algorithm can perform relative image registration and image matching of a multitemporal remote sensed dataset.

• Korean Journal of Environmental Agriculture
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• v.41 no.2
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• pp.135-151
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• 2022

BACKGROUND: The β-agonists known as phenyl ethanolamine derivatives have a conjugated aromatic ring with amino group. They are used as tocolytic agents and bronchodilator to human and animal generally, and some of them are used as growth promoters to livestock. METHODS AND RESULTS: β-agonists in samples were extracted by 0.4 N perchloric acid and ethyl acetate. The target compounds were analyzed by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS). Validation of method was performed according to CODEX guidelines (CAC/GL-71). The matrix matched calibration gave correlation coefficients>0.98, and the obtained recoveries were in the range of 62.0-109.8%, with relative standard deviation ≤ 20.1%. In addition, a survey was performed to inspect any residual β-agonist from 100 samples of livestock and fishery products and ractopamine was detected in one of the 100 samples. CONCLUSION(S): In this study, we established the analytical method for β-agonists through using the expanded target compounds and samples. And we anticipate that the established method would be used for analysis to determine veterinary drug residues in livestock and fishery products.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.64-72
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• 2023

Biopolymer is a versatile material used in food processing, medicine, construction, and soil reinforcement. 𝛽-glucan is one of the biopolymers that improves the soil water content and ion adsorption in a drought or toxic metal contaminated land for plant survival. We analyzed drought stress damage reduction in sweet potatoes (Ipomoea batatas L. cv. Sodammi) by measuring the growth and major protein expression and activity under 𝛽-glucan soil amendment. The result showed that sweet potato leaf length and width were not affected by drought stress for 14 days, but sweet potatoes grown in 𝛽-glucan-amended soil showed an effect in preventing wilting caused by drought in phenotypic changes. Under drought stress, sweet potato leaves did not show any changes in electrolyte leakage, but the relative water content was higher in sweet potatoes grown in 𝛽-glucan-amended soil than in normal soil. 𝛽-glucan soil amendment increased the expression of plasma membrane (PM) H⁺-ATPase, but it decreased the aquaporin PIP2 (plasma membrane intrinsic protein 2) in sweet potatoes under drought stress. Moreover, water maintenance affected the PM H⁺-ATPase activity, which contributed to tolerance under drought stress. These results indicate that 𝛽-glucan soil amendment improves the soil water content during drought and affects the water supply in sweet potatoes. Consequently, 𝛽-glucan is a potential material for maintaining soil water contents, and analysis of the major PM proteins is one of the indicators for evaluating the biopolymer effect on plant survival under drought stress.