首尔大学

We consider the Vlasov–Poisson equation on ℝ^n ×ℝ^n with n ≥ 3. We prove local well-posedness in H^s(ℝ^n ×ℝ^n) with s> n/2-1/4, for initial distribution f_0∈ H^s(ℝ^n ×ℝ^n) having compact support in v. In particular, data not belonging to L^p(ℝ^n ×ℝ^n) for large p are allowed.

This study aimed to evaluate the effects of three possible physical design features of self-service kiosks (SSK), side and back partitions and chairs, on task performance and workload of younger and older users during a typical SSK task. The study comparatively evaluated eight physical SSK design alternatives varying with regard to the use of the design features, and younger and older participants performed a menu ordering task using each physical design alternative. The study results indicated that the proper combination of the design features was found to help resolve an important SSK UX issue – the psychological and social stresses due to the unique environmental and situational characteristics of SSK. In particular, a medium degree of social exposure created by using either side partitions or a back partition was found to reduce NASA-TLX mental demand and effort for the older group. Also, providing a chair lowered temporal demand, frustration, and weighted average workload, and, improved task performance metrics for the older group without negatively affecting the younger group. The findings may contribute to improving the UX of public SSK.

Gray mold caused by Botrytis cinerea is a destructive postharvest disease affecting numerous fruit and vegetable crops worldwide, including tomato fruits, and results in substantial economic losses. In this study, an antifungal actinomycete, Streptomyces sp. KRA20–350, was isolated and characterized as a potent producer of metabolites active against B. cinerea. Considering that the culture filtrate of KRA20–350 strongly inhibited mycelial growth and conidial germination of B. cinerea and effectively suppressed gray mold development on tomato fruits, bioassay-guided purification identified tautomycetin as one of the major antifungal metabolites produced by KRA20–350. Tautomycetin exhibited potent antifungal activity against B. cinerea, inhibiting mycelial growth and conidial germination with IC50 values of 5.9 and 10.6 μg mL–1, respectively, and completely prevented gray mold development on tomato fruits at concentrations above 15.6 μg mL–1. Preventive application of tautomycetin to tomato seedlings achieved 85–98% disease control efficacy, whereas curative treatment showed only limited activity. Consistently, fungal penetration into onion epidermal tissues was markedly inhibited by tautomycetin. Drug-induced haploinsufficiency screening in Schizosaccharomyces pombe, molecular docking analysis, and genetic manipulation of the putative target gene in B. cinerea suggested that RNA 5′-triphosphatase may be a putative cellular target associated with tautomycetin sensitivity. Collectively, these findings demonstrate that Streptomyces sp. KRA20–350 produces tautomycetin, an effective antifungal metabolite with strong preventive activity against gray mold, highlighting its potential application as a postharvest biocontrol agent for tomato disease management.