• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.3
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• pp.111-120
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• 2019

The objective of this study was to investigate the effect of different feed inoculation method on rumen fermentation in an in vitro. Three experimental treatments were used: control (CON, direct dispersion of feed (2 g) in rumen fluid), combinations of direct dispersion (1 g) and nylon bag (DNB, pore size: 50 ㎛, 1 g), and nylon bag (NB, 2 g). An in vitro fermentation experiment was carried out using strained rumen fluid for 48 h incubation time and timothy was used as a substrate. At the end of the incubation, in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), pH, volatile fatty acids (VFA), ammonia nitrogen (NH₃-N), and microbial community were evaluated and gas production was estimated at 3, 6, 12, 24, 48 h incubation periods. Gas production was higher in CON than DNB and NB at 6 and 12 h incubation time (p<0.01). There were no differences in final gas production, pH, NH₃-N concentration, total VFA production, and VFA profiles among treatments. The IVDMD was lowest in CON (p<0.01) but the IVNDFD was not differed by feed distribution methods. There were no significant differences in general bacteria and fungi. Protozoa count was highest in NB treatment among treatments (p<0.01). The abundance of cellulolytic bacteria, Ruminococcus flavefaciens and Fibrobacter succinogenes, was highest in the CON among treatments (p<0.01).

• Journal of Wetlands Research
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• v.25 no.4
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• pp.335-344
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• 2023

Brachydiplax chalybea flavovittata, a climate-sensitive biological indicator species, was first observed and recorded at Jeju Island in Korea in 2010. Overwintering was recently confirmed in the Yeongsan River area. This study was aimed to predict the potential distribution patterns for the larvae of B. chalybea flavovittata and to understand its ecological characteristics as well as changes of population under global climate change circumstances. Data was collected both from the Global Biodiversity Information Facility (GBIF) and by field surveys from May 2019 to May 2023. We used for the distribution model among downloaded 19 variables from the WorldClim database. MaxEnt model was adopted for the prediction of potential and future distribution for B. chalybea flavovittata. Larval distribution ranged within a region delimited by northern latitude from Jeju-si, Jeju Special Self-Governing Province (33.318096°) to Yeoju-si, Gyeonggi-do (37.366734°) and eastern longitude from Jindo-gun, Jeollanam-do (126.054925°) to Yangsan-si, Gyeongsangnam-do (129.016472°). M type (permanent rivers, streams and creeks) wetlands were the most common habitat based on the Ramsar's wetland classification system, followed by Tp type (permanent freshwater marshes and pools) (45.8%) and F type (estuarine waters) (4.2%). MaxEnt model presented that potential distribution with high inhabiting probability included Ulsan and Daegu Metropolitan City in addition to the currently discovered habitats. Applying to the future scenarios by Intergovernmental Panel on Climate Change (IPCC), it was predicted that the possible distribution area would expand in the 2050s and 2090s, covering the southern and western coastal regions, the southern Daegu metropolitan area and the eastern coastal regions in the near future. This study suggests that B. chalybea flavovittata can be used as an effective indicator species for climate changes with a monitoring of their distribution ranges. Our findings will also help to provide basic information on the conservation and management of co-existing native species.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.779-793
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• 2023

Intensive and long-term aquaculture activities in Korea have generated considerable amounts of organic matter, deteriorating the sedimentary environment and ecosystem. The Korean government enacted the Fishery Management Act to preserve and manage the environment of fish farms. Based on this, a fisheries environment assessment has been conducted on fish cage farms since 2014, necessitating the development of a scientific and objective evaluation method suitable for the domestic environment. Therefore, a benthic health index (BHI) was developed using the relationship between benthic polychaete communities and organic matter, a major source of pollution in fish farms. In this study, the development process and calculation method of the BHI have been introduced. The BHI was calculated by classifying 225 species of polychaetes appearing in domestic coastal and aquaculture areas into four groups by linking the concentration gradient of the total organic carbon in the sediment and the distributional characteristics of each species and assigning differential weights to each group. Using BHI, the benthic fauna communities were assigned to one of the four ecological classes (Grade 1: Normal, Grade 2: Slightly polluted, Grade 3: Moderately polluted, and Grade 4: Heavily polluted). The application of the developed index in the field enabled effective evaluation of the Korean environment, being relatively more accurate and less affected by the season compared with the existing evaluation methods like the diversity index or AZTI's Marine Biotic Index developed overseas. In addition, using BHI will be useful in the environmental management of fish farms, as the environment can be graded in quantified figures.

• Journal of Life Science
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• v.33 no.10
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• pp.797-807
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• 2023

To improve the functionality of mulberry, samples were fermented with Lactobacillus plantarum JCM 1149 (LP) or Pichia kudriavzevii Atz-EN-01 (PK), and their antioxidant and anti-obesity activities were compared to those of unfermented mulberry. After fermenting for 60 hr, the total polyphenol and flavonoid content of the PK-fermented mulberry (PKFM) and LP-fermented mulberry (LPFM) was 1.5-fold and 2-fold higher, respectively, while the total anthocyanin content was 1.3-fold and 1.5-fold higher in the PKFM and LPFM, respectively. DPPH radical scavenging activity was found to be 16.3% higher (86% vs. 100%) after PK fermentation and 8.1% higher (86% vs. 93%) after LP fermentation. The lipase inhibitory activity of the LPFM and PKFM was 62.9% and 52.5%, respectively. 3T3-L1 preadipocytes were treated with unfermented mulberry, LPFM, or PKFM at 200, 400, or 800 ㎍/ml and stained with oil-red-O. A slight difference in the staining was observed in samples treated with 400 ㎍/ml. However, treatment with 800 ㎍/ml significantly reduced staining compared to the control, and the LPFM exhibited relatively higher adipogenesis inhibitory activity than the PKFM. Blood triglyceride content increased by 9.5% in the high-fat diet group, but decreased by 17.1% in the control group, 37.1% in the LPFM group, and 41.6% in the PKFM group. The blood triglyceride content of the LPFM group decreased by 43.1% and 21.4% compared to the high-fat diet group and the control group, respectively, and that of the PKFM group decreased by 48.6% and 28.9% compared to the same groups. In conclusion, the results indicate that fermented mulberry has increased antioxidant activity, lipase inhibitory activity, and adipogenesis inhibition activity, and decreased blood triglyceride content compared to unfermented mulberry.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.111-120
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• 2023

Purpose: Human rhinovirus (HRV) infections can result in lower respiratory tract infections (LRTIs). We aimed to investigate the characteristics of severe HRV LRTI in young children. Methods: Medical records were reviewed retrospectively in patients who were hospitalized for HRV LRTIs from 2016 to 2020 at the Samsung Medical Center in Seoul, Korea. Patients aged 90 days or older and younger than 5 years were included. Patients with co-infections with other respiratory pathogens were excluded. Severe HRV LRTI was defined as the following: the need for high-flow oxygenation, mechanical ventilation, or intensive care unit admission. Results: A total of 115 cases were identified. The median age was 17 months (range, 3-56 months) and the median hospital days were 4 days (range, 2-31 days). Of the 115 cases, 18 patients (15.7%) developed severe HRV LRTI. The median age was younger in the severe group compared to the non-severe group (9.5 months vs. 19.0 months, P=0.001). Of 18 patients with severe HRV LRTI, 11 (61.1%) had underlying diseases - chronic lung diseases accounted for the largest proportion (63.6%). Six patients (33.3%) required mechanical ventilation. Of note, 7 previously healthy children were diagnosed with severe HRV LRTI. Of those 7 children, 4 of them were diagnosed with asthma later. When the 115 cases were divided into previously healthy (n=60) and underlying disease (n=55) groups, severe courses of HRV LRTI were observed in 11.7% and 20.0% of children, respectively (P=0.219). Conclusions: HRV can cause severe LRTI even in previously healthy children as well as in children with comorbidities.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.807-820
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• 2023

Objective: To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. Materials and Methods: This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1-7 according to acquisition conditions. CT images in groups 2-7 were converted into the target CT style (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. Results: Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2-7 improved after CT conversion (original vs. converted: 0.63 vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists' scores were significantly higher (P < 0.001) and less variable on converted CT. Conclusion: CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

• Journal of Medicine and Life Science
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• v.21 no.2
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• pp.40-48
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• 2024

Understanding the effectiveness of statin treatment is essential for developing tailored stroke prevention strategies. We aimed to evaluate the efficacy of statin treatment in preventing recurrent stroke among patients with various ischemic stroke subtypes. Using data from the Clinical Research Collaboration for Stroke-Korea-National Institute for Health (CRCS-K-NIH) registry, we included patients with acute ischemic stroke admitted between January 2011 and July 2020. To evaluate the differential effects of statin treatment based on the ischemic stroke subtype, we analyzed patients with large artery atherosclerosis (LAA), cardio-embolism (CE), and small vessel occlusion (SVO). The primary outcomes were recurrent ischemic stroke and recurrent stroke events. The hazard ratio for outcomes between statin users and nonusers was compared using a Cox proportional hazards model adjusted for covariates. A total of 46,630 patients who met the inclusion criteria were analyzed. Statins were prescribed to 92%, 93%, and 78% of patients with LAA, SVO, and CE subtypes, respectively. The hazards of recurrent ischemic stroke and recurrent stroke in statin users were reduced to 0.79 (95% confidence interval [CI], 0.63-0.99) and 0.77 (95% CI, 0.62-0.95) in the LAA subtype and 0.63 (95% CI, 0.52-0.76) and 0.63 (95% CI, 0.53-0.75) in CE subtype compared to nonusers. However, the hazards of these outcomes did not significantly decrease in the SVO subtype. The effectiveness of statin treatment in reducing the risk of recurrent stroke in patients with LAA and CE subtypes has been suggested. Nonetheless, no significant effect was observed in the SVO subtype, suggesting a differential effect of statins on different stroke subtypes.

• The Mathematical Education
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• v.63 no.2
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• pp.123-138
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• 2024

This study described the utilization of ChatGPT in teaching and students' learning processes for the course "Introductory Mathematics for Artificial Intelligence (Math4AI)" at 'S' University. We developed a customized ChatGPT and presented a learning model in which students supplement their knowledge of the topic at hand by utilizing this model. More specifically, first, students learn the concepts and questions of the course textbook by themselves. Then, for any question they are unsure of, students may submit any questions (keywords or open problem numbers from the textbook) to our own ChatGPT at https://math4ai.solgitmath.com/ to get help. Notably, we optimized ChatGPT and minimized inaccurate information by fully utilizing various types of data related to the subject, such as textbooks, labs, discussion records, and codes at http://matrix.skku.ac.kr/Math4AI-ChatGPT/. In this model, when students have questions while studying the textbook by themselves, they can ask mathematical concepts, keywords, theorems, examples, and problems in natural language through the ChatGPT interface. Our customized ChatGPT then provides the relevant terms, concepts, and sample answers based on previous students' discussions and/or samples of Python or R code that have been used in the discussion. Furthermore, by providing students with real-time, optimized advice based on their level, we can provide personalized education not only for the Math4AI course, but also for any other courses in college math education. The present study, which incorporates our ChatGPT model into the teaching and learning process in the course, shows promising applicability of AI technology to other college math courses (for instance, calculus, linear algebra, discrete mathematics, engineering mathematics, and basic statistics) and in K-12 math education as well as the Lifespan Learning and Continuing Education.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.27-41
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• 2008

Distribution characteristics of phytoplankton community were investigated by HPLC and flow cytometry in Jeju Strait and the Northern East China Sea (NECS) in May 2004, in order to understand the relationship between physical environmental factors and distribution pattern of phytoplankton communities. Based on temperature and salinity data, three distinct water masses were identified; warm and saline Tsushima Warm Current (TWC), which is flowing from northwest of Jeju Island, warm and low saline water at the center of Jeju Strait, which is originated from China Coastal Water (CCW) and relatively cold and high saline water originated from Yellow Sea at the bottom of the Jeju Strait. At Jeju Strait, less saline water (<33 psu) of 15 km width occupied surface layer up to 20 m which located at 20 km offshore and strong thermal front between warm and saline water and cold and less saline water was found in the middle of the Jeju Strait. Vertical transect of temperature and salinity at the NECS also showed that low saline (<33 psu) water occupied the upper 20 m layer and cold and saline water was present at the eastern part. Chl a was measured as $0.06{\sim}3.07\;{\mu}g/L$. Spring bloom of phytoplankton was recognized by the high concentrations of Chl a at the low saline water masses influenced by the CCW and subsurface chlorophyll maximum layer appeared between $20{\sim}30\;m$ depth, which was at thermocline depth or below. Abundances of Synechococcus and picoeukaryote were $0.2{\sim}9.5{\times}10^4\;cells/mL$ and $0.43{\sim}4.3{\times}10^4\;cells/mL$, respectively. Dinoflagellate, diatom and prymnesiophyte were major groups and minor groups were chlorophyte+prasinophyte, chrysophyte, cryptophyte and cyanophyte. Especially high abundance of dinoflagellate was identified by high concentration (>1\;{\mu}g/L$) of peridinin at the bottom of the thermocline, which showed an outbreak of red tide by high density of dinoflagellates. Abundances of picoeukaryote in Jeju Strait were about $5{\sim}10$ times higher than abundance measured in Kuroshio water and showed a good correlation with Chl b (Pras+Viola), which implies the most of population of picoeukaryote was composed of prasinophytes. Prochlorococcus was not detected at all, which suggests that Kuroshio Current did not directly influenced on the study area. Based on the strong negative correlations between biomass of phytoplankton (Chl a) and temperature+salinity, the primary production and biomass of phytoplankton in the study area were controlled by the nutrients supply from CCW.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.65-71
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• 2024

The feather-sexing method is widely used commercially for chick sex identification. However, for feather-sexing to be industrially practical, the early-feathering (EF) and late-feathering (LF) genes must existed within the foundation stock, a suitable feather-sexing lines must be established, and the accuracy of sex identification by feather-sexing must be ensured. Therefore, this study introduces the method of constructing the Korean native chickens (KNC) feather-sexing lines using EF and LF genes and evaluates the effectiveness of feather sex determination on commercial chicks produced from the constructed KNC lines. The results showed that both EF and LF chickens existed within the foundation stock, with the frequency of LF genes ranging from 0 to 0.205. In feather-sexing line establishment, the paternal strain of the grandparent stock (GPS) was fixed as EF (kk) for both sexes, while the maternal strain was composed of males with LF homozygotes (Z^KZ^K) and females with EF (Z^kW). Thus, in the parent stock (PS), male breeder had EF (Z^kZ^k) and female breeder had LF (Z^KW), resulting in chicks produced from their crosses having LF (Z^KZ^k) for males and EF (Z^kW) for females, allowing sex determination based on feather development. Additionally, to evaluate the effectiveness of feather-sexing for the produced commercial chicks, a study was conducted on 1,000 samples of the produced chicks to investigate the concordance between vent-sexing and feather-sexing, showing a matching rate of 93.1%.