The objective of this study was to assess the effects of gypsum application on dry matter yield (DMY), mineral content of alfalfa (Medicago sativa L.), and soil properties in reclaimed tidal land in South Korea. The experiment was conducted in Seokmun, located on the west coast of South Korea, which is reclaimed with approximately 70 cm depth of degraded island soil. Treatments consisted of a control with no gypsum application (G0), 2 ton ha-1 (G2), and 4 ton ha-1 (G4) of gypsum application. The first harvest was carried out when the alfalfa reached 10% flowering, and subsequent harvests were conducted at 35-day intervals. Over the three-year experimental periods (2019-2021), the total DMY of G2 treatment was significantly higher than those of G0 and G4 (p<0.05). Although both G2 and G4 gypsum application treatments lowered soil pH, the G4 treatment increased the electrical conductivity (EC) content of the soil. Additionally, gypsum application affected the mineral contents of alfalfa, resulting in reduced concentration of sodium (Na) and Magnesium (Mg). Therefore, this present study suggests that a gypsum application rate of 2 ton ha-1 is optimal for improving alfalfa dry matter yield and mineral balance, as well as enhancing soil chemical properties in reclaimed tidal land in South Korea.

본 연구는 환경 요인을 바탕으로 절화용 국화 생장 예측을 위한 최적의 모델을 개발하는 것을 목표로 하였다. 이를 위해 13개의 모델(Linear Regression, Lasso Regression, Ridge Regression, ElasticNet Regression, K-Nearest Neighbors (KNN), Support Vector Regression (SVR), Neural Network, Decision Tree, Random Forest, XGBoost, AdaBoost, CatBoost, Stacking)의 성능을 R2, MAE, RMSE를 평가 지표 로 비교하였다. 단일 모델 중에서는 Decision Tree가 가장 우수한 성능을 보였으며, R2값은 0.90에서 0.91 사이였다. 앙 상블 모델 중에서는 CatBoost가 가장 높은 성능을 보였으며 (R2=0.90~0.92) Random Forest와 XGBoost 또한 유사한 성 능을 보였다. 전체적으로 트리 기반 앙상블 모델이 국화 생장 예측에 적합한 모델로 나타났다.

Background: Dairy cows exposed to heat stress have reduced milk production, milk quality, and conception rates, leading to lower profits. This study was conducted to analyze the effect of heat stress according to Temperature-Humidity Index (THI) on the milk production of Korean Holstein cows. Methods: Monthly maximum temperature and average relative humidity data from January 2017 to August 2024 were obtained from 62 observation points used by the Korea Meteorological Administration to calculate the national average. Using this data, the THI, a key indicator for assessing heat stress in Korean Holstein cows, was calculated. Additionally, data from 240,088 Korean Holstein cows, collected through tests conducted by the Dairy Cattle Improvement Center of the NH-Agri Business Group, were analyzed. Results: Comparative analysis of the relationship between THI and milk production revealed that milk yield remained relatively stable until THI reached the “very severe” heat stress threshold (THI ≥ 79). Beyond this level, milk production showed a tendency to decline. Conversely, when THI dropped below this threshold, milk yield tended to recover. Notably, the temperature in September, typically considered part of the autumn season, has been rising in recent years, with THI values now approaching the very severe stress level (THI ≥ 79). Conclusions: These findings suggest that establishing an appropriate farm environment and implementing systematic THI management are essential for mitigating the decline in milk production, as well as the associated economic losses, caused by rising domestic temperatures due to global warming.

본 연구는 우리나라에 자생하는 목본 관상용 식물인 먼나무 (Ilex rotunda)와 으름덩굴(Akebia quinata)을 대상으로 삽목 효율을 분석하였다. 삽수는 녹지와 숙지로 구분하고 생장조절 제 indole-3-butyric acid (IBA)와 시판용 발근촉진제 루톤 (Rootone)을 처리하여 대조군과 비교하였다. 그 결과, 발근율 (녹지, 숙지)은 먼나무(50.9, 19.0%) 및 으름덩굴(52.8, 28.5%) 로 두 수종 모두 숙지보다는 녹지가 손쉽게 발근되었다. 생장조절 제의 발근 촉진 효과는 녹지보다는 숙지에서 두드러졌으며, 생장 조절제 효과는 두 수종에서 상이하게 나타났으며, IBA와 루톤에 대한 두 수종의 발근 반응이 다르게 나타냈다. IBA 1,000ppm 처리는 먼나무의 발근을 촉진시켰고(65.9%) 으름덩굴에서는 고 사에 따른 발근율 저하를 야기하였으며(5.0%), 오히려 으름덩굴 은 루톤 처리로 발근이 촉진되었다(83.3%).

Amitriptyline hydrochloride (AMT), a tricyclic antidepressant, is known to exhibit antimicrobial effects against a wide range of bacterial species. This study aims to evaluate the effect of AMT on Brucella (B.) abortus infection in RAW 264.7 cells and ICR mice, which has not yet been clearly characterized. The results showed that all tested concentrations of AMT had no direct bactericidal effect on B. abortus survival at any incubation time point. Interestingly, RAW 264.7 cells pre-treated with a non-toxic high concentration of AMT before B. abortus infection showed a significant reduction in the phagocytosis of B. abortus at 20 min post-infection, compared to untreated cells. However, AMT treatment did not affect the intracellular replication of B. abortus compared to the control cells. Based on the reduced bacterial uptake observed in-vitro, an in-vivo experiment was conducted to assess whether daily oral administration of AMT at a dose of 20 mg/kg could inhibit B. abortus growth in ICR mice. The results showed that AMT treatment slightly increased both organ weights and bacterial loads, suggesting possible systemic effects of prolonged AMT exposure. In summary, these preliminary results provide initial insight into the potential effects of AMT on B. abortus infection both in-vitro and in-vivo. Therefore, further study should focus on dose optimization in-vivo and exploration of the underlying cellular mechanisms involved in AMT-mediated inhibition of phagocytosis during Brucella infection.

Virtual Reality Head Mounted Display (VR HMD)-based flight simulators have recently emerged as promising tools for enhancing pilot training effectiveness. This study aims to establish a set of evaluation criteria for the development of VR HMD-based flight simulators and to determine their relative importance and priority using the Analytic Hierarchy Process (AHP). Through an extensive review of the literature, a hierarchical evaluation model was constructed, consisting of three primary criteria and ten sub-criteria. A structured questionnaire was administered to experienced pilots, and the collected data were analyzed using the AHP methodology to assess the relative weights of each criterion. The analysis revealed that the fidelity of system performance is the most influential factor in evaluating VR HMD-based flight simulators. These findings present a structured evaluation framework and offer practical insights for guiding the strategic development and optimization of VR HMD-based flight training systems.

본 연구는 습도센서에서 Zn-MOF (금속-유기구조)의 개발과 응용에 대해 다루며, 친환경적 합성과 우수한 전기적 특성을 보고한다. 그린 화학의 원리를 이용하여 제작된 Zn-MOF를 유연한 폴리에 틸렌테레프탈레이트 기판 상에 형성된 깍지낀 구조의 전극과 통합하였다. 상대습도가 10%부터 90%까지 증가할 때, 전기적 특성은 42.49 pF에서 370 nF까지 정전용량의 급격한 상승(약 939,322%)을 나타냈다. 또한, 임피던스는 47 MΩ에서 0.072 MΩ까지 약 99.81% 감소하였다. 제작된 습도센서는 반응시간 5초, 복구시간 약 0.7에서 0.9초로 동적으로 반응하였다. 이러한 결과는 Zn-MOF가 고도로 민감하고 반응성이 뛰어난 습도 모니터링할 수 있는 가능성과, 특히 다양한 환경 조건에서 센서의 정전용량성 반응성을 강조 하고자 한다.

Maca has been reported to alleviate male menopause symptoms in humans and experimental animals; however, its mechanism of action in improving male menopause has not been clearly identified. This study aimed to investigate the mechanism of action of gelatinized maca in improving male menopause by analyzing serum testosterone, testicular androgen receptor (AR) expression, and testicular oxidation-antioxidation balance. Gelatinized maca was administered orally to aged male C57BL/6 mice at three doses (500, 1,000, and 1,500 mg/kg/day) for 28 consecutive days. Serum biochemical analysis showed an increase in serum hydroxysteroid 17-beta-dehydrogenase 13 (HSD17β13) concentration at 1,500 mg/kg/day and a decrease in serum sex hormone-binding globulin (SHBG) concentration at ≥ 1,000 mg/kg/day. Gelatinized maca administration also resulted in the increased expression levels of testicular AR and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) at 1,500 mg/kg/day. Oxidative stress analysis showed an increase in testicular superoxide dismutase and glutathione reductase activities and a decrease in testicular malondialdehyde at 1,500 mg/kg/day. In conclusion, gelatinized maca administration to aged male mice increased HSD17β13, AR and CREB expression, and antioxidant capacity and decreased serum SHBG. The results of the present study suggest that gelatinized maca may be a useful substance that can help alleviate male menopause symptoms.