Salinity is a major abiotic stress for crop plants that cause reduced food production. The application of plant growth-promoting microorganisms can improve the adaptability of plants to biotic and abiotic stresses. Therefore, in the current study, we aimed to enhance the mitigation effects of artificially applied rhizobacterium Klebsiella variicola AY13 on salinity stress in Trifolium repens L. The results suggested that AY13 innately produced indole-3-acetic acid and accelerated the morphological adaptation of T. repens to salt stress conditions. Furthermore, AY13 promotes a Trp-dependent pathway for indole-3-acetic acid (IAA) production, as adding L-tryptophan (L-Trp) increased IAA production in pure culture. AY13 improved plant growth by maintaining relative water content and minimizing water loss in excised leaves. Moreover, AY13 inoculation significantly reduced the endogenous levels of abscisic acid and antioxidants such as glutathione and catalase. These results suggest that AY13 plays a crucial role in reprogramming stress-related metabolism and enhancing plant stress tolerance.

This study investigated chlorpheniramine maleate (CPM) residues in milk of intramuscularly dosed dairy cows and established the withdrawal time (WT) of CPM in milk. Sixteen healthy Holstein cows were injected with 10 (CPM-1) and 20 mL (CPM-2) of the drug containing 4 mg/mL of CPM, respectively. After administration of CPM, milk samples were collected from all cows at 12 hour intervals for 5 days. CPM residue concentrations in milk were determined using LC-MS/MS. The correlation coefficient of the calibration curve was 0.9956, and the limits of detection and quantification (LOQ) were 0.6 and 1.0 μg/kg, respectively. Recoveries ranged between 98.5-115.0%, and coefficient of variations were less than 10.96%. After treatment, CPM in CPM-1 and CPM-2 was detected below the LOQ in all milk samples at 12 hours. According to the European Medicines Agency’s guideline on determination of withdrawal periods for milk, withdrawal periods of both CPM-1 and CPM-2 in milk were established to 12 hours. In conclusion, the developed analytical method is sensitive and reliable for detection of CPM in milk, and the estimated WT of CPM in bovine milk will contribute to ensuring the safety of milk.

210Po is a naturally occurring radionuclide of 238U decay series with a half-life of 138.4 days. 210Po is decay products of 222Rn, which escapes into the atmosphere and present in all environments with aerosol particles. Also, 210Po has high radiotoxicity and emits a high alpha energy of 5.305 MeV, and it decays to finally become a stable isotope, 206Pb. Therefore, 210Po entering the body by continuously ingestion or inhalation is likely to cause severe damage to the bone marrow, kidney and spleen and other sites in the body. Accordingly, the World Health Organization (WHO) recommends that screening level of gross alpha for drinking water not exceed 0.5 Bq·L−1. Alpha spectrometry has been mainly used for analysis of 210Po, and for the accurate measurement of alpha particle with short range, it is essential to prepare suitable source for alpha detection. The 210Po alpha source is made by a spontaneous deposition method in which polonium is adsorbed thin and flat onto a metal disc, such as silver, nickel and copper. There are various pretreatment methods to separate and concentrate polonium from water samples prior to spontaneous deposition, including Fe(OH)3 or MnO2 co-precipitation and evaporation. However, in the case of co-precipitation, sample contamination or loss of polonium may occur through the experimental processes, and evaporation lead to not only time-consuming process but also may cause loss of polonium due to the low boiling point of polonium. Therefore, in order to compensate for these problems, an efficient polonium analysis method that directly collects polonium from the original sample without a pretreatment is required. In this study, 210Po in bottled drinking water sold in Korea was analyzed using alpha spectrometry. A high purity silver disc (99.99%) was inserted into a newly designed polonium deposition kit to quickly and conveniently collect polonium from a water sample. The polonium alpha detecting source was made effectively only by the spontaneous deposition method without a complicated pretreatment. The source was measured using a PIPS detector, and the radioactivity concentration of 210Po was calculated using 209Po as a yield tracer.

The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R2) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

Tensions are high between Korea and Japan as a result of Japan’s export restrictions on three essential semiconductor materials exported to Korea and the removal of South Korea from their White List of countries. The Abe Administration announced that these measures were necessary to “ensure non-proliferation of weapons-related materials.” However, it is widely suspected that these measures were adopted as a retaliation against the Korean Supreme Court’s decision recognizing compensation for the forced labor victims during the Japanese occupation period. The Korean government filed a complaint concerning these measures at the WTO DSB for resolution under international law. In this research, the authors will critically analyze Japan’s export restrictions under international law to facilitate a peaceful resolution to the current conflict. This paper will tackle the relevant issues under the WTO/GATT regulations and the Korea-Japan Claims Agreement to address the issue of who violated international law.