An extensive assessment of seasonal rainfall on intracellular and extracellular antibiotic resistance genes in Urban River systems.

Rainfall events are responsible for the accelerated transfer of antibiotic-resistant contaminants to receiving environments. However, the specific profiles of various ARG types, including intra- and extracellular ARGs (iARGs and eARGs) responding to season rainfall needed more comprehensive assessments. Particularly, the key factors driving the distribution and transport of iARGs and eARGs have not been well characterized. Results revealed that the absolute abundance of eARGs was observed to be more than one order of magnitude greater than that of iARGs during the dry season in the reservoir. However, the absolute abundance of iARGs significantly increased after rainfall (p < 0.01). Meanwhile, seasonal rainfall significantly decreased the diversity of eARGs and the number of shared genes between iARGs and eARGs (p < 0.01). Results of structural equation models (SEM) and network analysis showed the rank and co-occurrence of influencing factors (e.g., microbial community, MGEs, environmental variables, and dissolved organic matter (DOM)) concerning the changes in iARGs and eARGs. DOM contributed majorly to eARGs in the reservoir and pathogens was responsible for eARGs in the river during the wet season. Network analysis revealed that the tnp-04 and IS613 genes-related MGEs co-occurred with eARGs in the dry and wet seasons, which were regarded as potential molecular indicators to shape eARGs profiles in urban rivers. Besides, the results demonstrated close relationships between DOM fluorescence signatures and two-typed ARGs. Specifically, humic acid was significantly and positively correlated with the eARGs in the reservoir during the wet season, while fulvic acid-like substances exhibited strong correlations of iARGs and eARGs in the river during the dry season (p < 0.01). This work provides extensive insights into the potential effect of seasonal rainfall on the dynamic distribution of iARGs and eARGs and the dominance of DOM in driving the fate of two-typed ARGs in urban river systems.

Optimal number of charging station and pricing strategy for the electric vehicle with component commonality considering consumer range anxiety.

The battery driving mileage on a single charge and convenience of the charging stations affect Electric Vehicle's (EV) demand. This paper studies the optimal number of charging stations and EV's price strategy considering different component commonality configurations. Assume the EV manufacturer provides two types of EV and the two EVs have the same battery configuration (battery as a common part) or the same naked vehicle-EV without batteries (naked vehicle as a common part). And the common part could be configured with low or high quality. We discuss four scenarios with different common parts and different quality levels. For each scenario, we present the optimal number of the charging stations and EV prices. Then we compare the optimal solutions and manufacturer's profits in above four scenarios with numerical simulation and give some managerial insights. Our analysis reveals that (1) consumers' range anxiety towards battery will affect manufacturer's product configuration strategy, EVs' prices and demands. (2) large consumers' sensitivity towards charging station will corresponding to more charging station, high EV prices and demands. If consumers are very concerned about the charging convenience, high-end electric vehicles need to be launched first, then as customers' anxiety about charging decreases, the low quality EV could be developed and diffused. (3) the unit product cost reduction caused by the commonality may increase or decrease the EVs' prices, which depends on the relationship between the demand increment incurred by one more charging station and the cost coefficient of building the charging station. (4) The low quality naked vehicle as common component will increase both the number of the charging stations and the demand and the manufacturer is more likely to obtain high profits. (5) the cost saving coefficient of battery common parts has greater influence on the selection of commonality. When consumers' range anxiety towards battery is very high, manufacturers should choose low-quality naked vehicles or high-quality battery as common components.